* [PATCH 2/5] mmu_notifier: add action information to address invalidation.
2014-06-12 18:57 ` [PATCH 1/5] mm: differentiate unmap for vmscan from other unmap j.glisse
@ 2014-06-12 18:57 ` j.glisse
2014-06-12 18:57 ` [PATCH 3/5] mmu_notifier: pass through vma to invalidate_range and invalidate_page j.glisse
` (2 subsequent siblings)
3 siblings, 0 replies; 5+ messages in thread
From: j.glisse @ 2014-06-12 18:57 UTC (permalink / raw)
To: akpm, linux-kernel, linux-mm; +Cc: Jérôme Glisse
From: Jérôme Glisse <jglisse@redhat.com>
The action information will be usefull for new user of mmu_notifier API.
The action argument differentiate between a vma disappearing, a page
being write protected or simply a page being unmaped. This allow new
user to take different action for instance on unmap the resource used
to track a vma are still valid and should stay around if need be.
While if the action is saying that a vma is being destroy it means that
that any resources used to track this vma can be free.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
---
drivers/gpu/drm/i915/i915_gem_userptr.c | 3 +-
drivers/iommu/amd_iommu_v2.c | 14 +++--
drivers/misc/sgi-gru/grutlbpurge.c | 9 ++-
drivers/xen/gntdev.c | 9 ++-
fs/proc/task_mmu.c | 4 +-
include/linux/hugetlb.h | 7 ++-
include/linux/mmu_notifier.h | 108 +++++++++++++++++++++++++-------
kernel/events/uprobes.c | 6 +-
mm/filemap_xip.c | 2 +-
mm/huge_memory.c | 26 ++++----
mm/hugetlb.c | 19 +++---
mm/ksm.c | 12 ++--
mm/memory.c | 23 +++----
mm/mempolicy.c | 2 +-
mm/migrate.c | 6 +-
mm/mmu_notifier.c | 26 +++++---
mm/mprotect.c | 30 ++++++---
mm/mremap.c | 4 +-
mm/rmap.c | 31 +++++++--
virt/kvm/kvm_main.c | 12 ++--
20 files changed, 238 insertions(+), 115 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 21ea928..7f7b4f3 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -56,7 +56,8 @@ struct i915_mmu_object {
static void i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn,
struct mm_struct *mm,
unsigned long start,
- unsigned long end)
+ unsigned long end,
+ enum mmu_action action)
{
struct i915_mmu_notifier *mn = container_of(_mn, struct i915_mmu_notifier, mn);
struct interval_tree_node *it = NULL;
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index d4daa05..81ff80b 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -413,21 +413,25 @@ static int mn_clear_flush_young(struct mmu_notifier *mn,
static void mn_change_pte(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long address,
- pte_t pte)
+ pte_t pte,
+ enum mmu_action action)
{
__mn_flush_page(mn, address);
}
static void mn_invalidate_page(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long address)
+ unsigned long address,
+ enum mmu_action action)
{
__mn_flush_page(mn, address);
}
static void mn_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action)
{
struct pasid_state *pasid_state;
struct device_state *dev_state;
@@ -444,7 +448,9 @@ static void mn_invalidate_range_start(struct mmu_notifier *mn,
static void mn_invalidate_range_end(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action)
{
struct pasid_state *pasid_state;
struct device_state *dev_state;
diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c
index 2129274..3427bfc 100644
--- a/drivers/misc/sgi-gru/grutlbpurge.c
+++ b/drivers/misc/sgi-gru/grutlbpurge.c
@@ -221,7 +221,8 @@ void gru_flush_all_tlb(struct gru_state *gru)
*/
static void gru_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start, unsigned long end,
+ enum mmu_action action)
{
struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
ms_notifier);
@@ -235,7 +236,8 @@ static void gru_invalidate_range_start(struct mmu_notifier *mn,
static void gru_invalidate_range_end(struct mmu_notifier *mn,
struct mm_struct *mm, unsigned long start,
- unsigned long end)
+ unsigned long end,
+ enum mmu_action action)
{
struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
ms_notifier);
@@ -248,7 +250,8 @@ static void gru_invalidate_range_end(struct mmu_notifier *mn,
}
static void gru_invalidate_page(struct mmu_notifier *mn, struct mm_struct *mm,
- unsigned long address)
+ unsigned long address,
+ enum mmu_action action)
{
struct gru_mm_struct *gms = container_of(mn, struct gru_mm_struct,
ms_notifier);
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 073b4a1..84aa5a7 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -428,7 +428,9 @@ static void unmap_if_in_range(struct grant_map *map,
static void mn_invl_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action)
{
struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
struct grant_map *map;
@@ -445,9 +447,10 @@ static void mn_invl_range_start(struct mmu_notifier *mn,
static void mn_invl_page(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long address)
+ unsigned long address,
+ enum mmu_action action)
{
- mn_invl_range_start(mn, mm, address, address + PAGE_SIZE);
+ mn_invl_range_start(mn, mm, address, address + PAGE_SIZE, action);
}
static void mn_release(struct mmu_notifier *mn,
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index 3c16356..fda2324 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -824,11 +824,11 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
};
down_read(&mm->mmap_sem);
if (type == CLEAR_REFS_SOFT_DIRTY)
- mmu_notifier_invalidate_range_start(mm, 0, -1);
+ mmu_notifier_invalidate_range_start(mm, 0, -1, MMU_SOFT_DIRTY);
for (vma = mm->mmap; vma; vma = vma->vm_next)
walk_page_vma(vma, &clear_refs_walk);
if (type == CLEAR_REFS_SOFT_DIRTY)
- mmu_notifier_invalidate_range_end(mm, 0, -1);
+ mmu_notifier_invalidate_range_end(mm, 0, -1, MMU_SOFT_DIRTY);
flush_tlb_mm(mm);
up_read(&mm->mmap_sem);
mmput(mm);
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 6a836ef..13ea5e8 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -6,6 +6,7 @@
#include <linux/fs.h>
#include <linux/hugetlb_inline.h>
#include <linux/cgroup.h>
+#include <linux/mmu_notifier.h>
#include <linux/list.h>
#include <linux/kref.h>
@@ -103,7 +104,8 @@ struct page *follow_huge_pud(struct mm_struct *mm, unsigned long address,
int pmd_huge(pmd_t pmd);
int pud_huge(pud_t pmd);
unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
- unsigned long address, unsigned long end, pgprot_t newprot);
+ unsigned long address, unsigned long end, pgprot_t newprot,
+ enum mmu_action action);
#else /* !CONFIG_HUGETLB_PAGE */
@@ -148,7 +150,8 @@ static inline bool isolate_huge_page(struct page *page, struct list_head *list)
#define is_hugepage_active(x) false
static inline unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
- unsigned long address, unsigned long end, pgprot_t newprot)
+ unsigned long address, unsigned long end, pgprot_t newprot,
+ enum mmu_action action)
{
return 0;
}
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index deca874..90b9105 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -9,6 +9,41 @@
struct mmu_notifier;
struct mmu_notifier_ops;
+/* Action report finer information to the callback allowing the event listener
+ * to take better action. For instance WP means that the page are still valid
+ * and can be use as read only.
+ *
+ * UNMAP means the vma is still valid and that only pages are unmaped and thus
+ * they should no longer be read or written to.
+ *
+ * ZAP means vma is disappearing and that any resource that were use to track
+ * this vma can be freed.
+ *
+ * In doubt when adding a new notifier caller use ZAP it will always trigger
+ * right thing but won't be optimal.
+ */
+enum mmu_action {
+ MMU_MPROT_NONE = 0,
+ MMU_MPROT_RONLY,
+ MMU_MPROT_RANDW,
+ MMU_MPROT_WONLY,
+ MMU_COW,
+ MMU_KSM,
+ MMU_KSM_RONLY,
+ MMU_SOFT_DIRTY,
+ MMU_UNMAP,
+ MMU_VMSCAN,
+ MMU_POISON,
+ MMU_MREMAP,
+ MMU_MUNMAP,
+ MMU_MUNLOCK,
+ MMU_MIGRATE,
+ MMU_FILE_WB,
+ MMU_FAULT_WP,
+ MMU_THP_SPLIT,
+ MMU_THP_FAULT_WP,
+};
+
#ifdef CONFIG_MMU_NOTIFIER
/*
@@ -79,7 +114,8 @@ struct mmu_notifier_ops {
void (*change_pte)(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long address,
- pte_t pte);
+ pte_t pte,
+ enum mmu_action action);
/*
* Before this is invoked any secondary MMU is still ok to
@@ -90,7 +126,8 @@ struct mmu_notifier_ops {
*/
void (*invalidate_page)(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long address);
+ unsigned long address,
+ enum mmu_action action);
/*
* invalidate_range_start() and invalidate_range_end() must be
@@ -137,10 +174,14 @@ struct mmu_notifier_ops {
*/
void (*invalidate_range_start)(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long start, unsigned long end);
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action);
void (*invalidate_range_end)(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long start, unsigned long end);
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action);
};
/*
@@ -177,13 +218,20 @@ extern int __mmu_notifier_clear_flush_young(struct mm_struct *mm,
extern int __mmu_notifier_test_young(struct mm_struct *mm,
unsigned long address);
extern void __mmu_notifier_change_pte(struct mm_struct *mm,
- unsigned long address, pte_t pte);
+ unsigned long address,
+ pte_t pte,
+ enum mmu_action action);
extern void __mmu_notifier_invalidate_page(struct mm_struct *mm,
- unsigned long address);
+ unsigned long address,
+ enum mmu_action action);
extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
- unsigned long start, unsigned long end);
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action);
extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
- unsigned long start, unsigned long end);
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action);
static inline void mmu_notifier_release(struct mm_struct *mm)
{
@@ -208,31 +256,38 @@ static inline int mmu_notifier_test_young(struct mm_struct *mm,
}
static inline void mmu_notifier_change_pte(struct mm_struct *mm,
- unsigned long address, pte_t pte)
+ unsigned long address,
+ pte_t pte,
+ enum mmu_action action)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_change_pte(mm, address, pte);
+ __mmu_notifier_change_pte(mm, address, pte, action);
}
static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
- unsigned long address)
+ unsigned long address,
+ enum mmu_action action)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_invalidate_page(mm, address);
+ __mmu_notifier_invalidate_page(mm, address, action);
}
static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_invalidate_range_start(mm, start, end);
+ __mmu_notifier_invalidate_range_start(mm, start, end, action);
}
static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_invalidate_range_end(mm, start, end);
+ __mmu_notifier_invalidate_range_end(mm, start, end, action);
}
static inline void mmu_notifier_mm_init(struct mm_struct *mm)
@@ -278,13 +333,13 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
* old page would remain mapped readonly in the secondary MMUs after the new
* page is already writable by some CPU through the primary MMU.
*/
-#define set_pte_at_notify(__mm, __address, __ptep, __pte) \
+#define set_pte_at_notify(__mm, __address, __ptep, __pte, __action) \
({ \
struct mm_struct *___mm = __mm; \
unsigned long ___address = __address; \
pte_t ___pte = __pte; \
\
- mmu_notifier_change_pte(___mm, ___address, ___pte); \
+ mmu_notifier_change_pte(___mm, ___address, ___pte, __action); \
set_pte_at(___mm, ___address, __ptep, ___pte); \
})
@@ -307,22 +362,29 @@ static inline int mmu_notifier_test_young(struct mm_struct *mm,
}
static inline void mmu_notifier_change_pte(struct mm_struct *mm,
- unsigned long address, pte_t pte)
+ unsigned long address,
+ pte_t pte,
+ enum mmu_action action)
{
}
static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
- unsigned long address)
+ unsigned long address,
+ enum mmu_action action)
{
}
static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action)
{
}
static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action)
{
}
@@ -336,7 +398,7 @@ static inline void mmu_notifier_mm_destroy(struct mm_struct *mm)
#define ptep_clear_flush_young_notify ptep_clear_flush_young
#define pmdp_clear_flush_young_notify pmdp_clear_flush_young
-#define set_pte_at_notify set_pte_at
+#define set_pte_at_notify(__mm, __address, __ptep, __pte, __action) set_pte_at(__mm, __address, __ptep, __pte)
#endif /* CONFIG_MMU_NOTIFIER */
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index c445e39..3e2308f 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -171,7 +171,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
/* For try_to_free_swap() and munlock_vma_page() below */
lock_page(page);
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_UNMAP);
err = -EAGAIN;
ptep = page_check_address(page, mm, addr, &ptl, 0);
if (!ptep)
@@ -187,7 +187,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
flush_cache_page(vma, addr, pte_pfn(*ptep));
ptep_clear_flush(vma, addr, ptep);
- set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
+ set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot), MMU_UNMAP);
page_remove_rmap(page);
if (!page_mapped(page))
@@ -200,7 +200,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
err = 0;
unlock:
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_UNMAP);
unlock_page(page);
return err;
}
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index d8d9fe3..d529ab9 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -198,7 +198,7 @@ retry:
BUG_ON(pte_dirty(pteval));
pte_unmap_unlock(pte, ptl);
/* must invalidate_page _before_ freeing the page */
- mmu_notifier_invalidate_page(mm, address);
+ mmu_notifier_invalidate_page(mm, address, MMU_UNMAP);
page_cache_release(page);
}
}
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index c5ff461..4ad9b73 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -993,7 +993,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
mmun_start = haddr;
mmun_end = haddr + HPAGE_PMD_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
ptl = pmd_lock(mm, pmd);
if (unlikely(!pmd_same(*pmd, orig_pmd)))
@@ -1023,7 +1023,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
page_remove_rmap(page);
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
ret |= VM_FAULT_WRITE;
put_page(page);
@@ -1033,7 +1033,7 @@ out:
out_free_pages:
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
mem_cgroup_uncharge_start();
for (i = 0; i < HPAGE_PMD_NR; i++) {
mem_cgroup_uncharge_page(pages[i]);
@@ -1123,7 +1123,7 @@ alloc:
mmun_start = haddr;
mmun_end = haddr + HPAGE_PMD_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
spin_lock(ptl);
if (page)
@@ -1153,7 +1153,7 @@ alloc:
}
spin_unlock(ptl);
out_mn:
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
out:
return ret;
out_unlock:
@@ -1588,7 +1588,7 @@ static int __split_huge_page_splitting(struct page *page,
const unsigned long mmun_start = address;
const unsigned long mmun_end = address + HPAGE_PMD_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
pmd = page_check_address_pmd(page, mm, address,
PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG, &ptl);
if (pmd) {
@@ -1603,7 +1603,7 @@ static int __split_huge_page_splitting(struct page *page,
ret = 1;
spin_unlock(ptl);
}
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
return ret;
}
@@ -2402,7 +2402,7 @@ static void collapse_huge_page(struct mm_struct *mm,
mmun_start = address;
mmun_end = address + HPAGE_PMD_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
pmd_ptl = pmd_lock(mm, pmd); /* probably unnecessary */
/*
* After this gup_fast can't run anymore. This also removes
@@ -2412,7 +2412,7 @@ static void collapse_huge_page(struct mm_struct *mm,
*/
_pmd = pmdp_clear_flush(vma, address, pmd);
spin_unlock(pmd_ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
spin_lock(pte_ptl);
isolated = __collapse_huge_page_isolate(vma, address, pte);
@@ -2801,24 +2801,24 @@ void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
mmun_start = haddr;
mmun_end = haddr + HPAGE_PMD_SIZE;
again:
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
ptl = pmd_lock(mm, pmd);
if (unlikely(!pmd_trans_huge(*pmd))) {
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
return;
}
if (is_huge_zero_pmd(*pmd)) {
__split_huge_zero_page_pmd(vma, haddr, pmd);
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
return;
}
page = pmd_page(*pmd);
VM_BUG_ON_PAGE(!page_count(page), page);
get_page(page);
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
split_huge_page(page);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 2e7ac30..bfb455e 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2540,7 +2540,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
mmun_start = vma->vm_start;
mmun_end = vma->vm_end;
if (cow)
- mmu_notifier_invalidate_range_start(src, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(src, mmun_start, mmun_end, MMU_COW);
for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
spinlock_t *src_ptl, *dst_ptl;
@@ -2574,7 +2574,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
}
if (cow)
- mmu_notifier_invalidate_range_end(src, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(src, mmun_start, mmun_end, MMU_COW);
return ret;
}
@@ -2626,7 +2626,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
BUG_ON(end & ~huge_page_mask(h));
tlb_start_vma(tlb, vma);
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_UNMAP);
again:
for (address = start; address < end; address += sz) {
ptep = huge_pte_offset(mm, address);
@@ -2697,7 +2697,7 @@ unlock:
if (address < end && !ref_page)
goto again;
}
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_UNMAP);
tlb_end_vma(tlb, vma);
}
@@ -2884,7 +2884,7 @@ retry_avoidcopy:
mmun_start = address & huge_page_mask(h);
mmun_end = mmun_start + huge_page_size(h);
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_UNMAP);
/*
* Retake the page table lock to check for racing updates
* before the page tables are altered
@@ -2904,7 +2904,7 @@ retry_avoidcopy:
new_page = old_page;
}
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_UNMAP);
page_cache_release(new_page);
page_cache_release(old_page);
@@ -3329,7 +3329,8 @@ same_page:
}
unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
- unsigned long address, unsigned long end, pgprot_t newprot)
+ unsigned long address, unsigned long end, pgprot_t newprot,
+ enum mmu_action action)
{
struct mm_struct *mm = vma->vm_mm;
unsigned long start = address;
@@ -3341,7 +3342,7 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
BUG_ON(address >= end);
flush_cache_range(vma, address, end);
- mmu_notifier_invalidate_range_start(mm, start, end);
+ mmu_notifier_invalidate_range_start(mm, start, end, action);
mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
for (; address < end; address += huge_page_size(h)) {
spinlock_t *ptl;
@@ -3371,7 +3372,7 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
*/
flush_tlb_range(vma, start, end);
mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
- mmu_notifier_invalidate_range_end(mm, start, end);
+ mmu_notifier_invalidate_range_end(mm, start, end, action);
return pages << h->order;
}
diff --git a/mm/ksm.c b/mm/ksm.c
index 68710e8..6a32bc4 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -872,7 +872,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
mmun_start = addr;
mmun_end = addr + PAGE_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_KSM_RONLY);
ptep = page_check_address(page, mm, addr, &ptl, 0);
if (!ptep)
@@ -904,7 +904,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
if (pte_dirty(entry))
set_page_dirty(page);
entry = pte_mkclean(pte_wrprotect(entry));
- set_pte_at_notify(mm, addr, ptep, entry);
+ set_pte_at_notify(mm, addr, ptep, entry, MMU_KSM_RONLY);
}
*orig_pte = *ptep;
err = 0;
@@ -912,7 +912,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
out_unlock:
pte_unmap_unlock(ptep, ptl);
out_mn:
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_KSM_RONLY);
out:
return err;
}
@@ -949,7 +949,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
mmun_start = addr;
mmun_end = addr + PAGE_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_KSM);
ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
if (!pte_same(*ptep, orig_pte)) {
@@ -962,7 +962,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
flush_cache_page(vma, addr, pte_pfn(*ptep));
ptep_clear_flush(vma, addr, ptep);
- set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot));
+ set_pte_at_notify(mm, addr, ptep, mk_pte(kpage, vma->vm_page_prot), MMU_KSM);
page_remove_rmap(page);
if (!page_mapped(page))
@@ -972,7 +972,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
pte_unmap_unlock(ptep, ptl);
err = 0;
out_mn:
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_KSM);
out:
return err;
}
diff --git a/mm/memory.c b/mm/memory.c
index 532dde2..55d4e91 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1050,7 +1050,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
mmun_end = end;
if (is_cow)
mmu_notifier_invalidate_range_start(src_mm, mmun_start,
- mmun_end);
+ mmun_end, MMU_COW);
ret = 0;
dst_pgd = pgd_offset(dst_mm, addr);
@@ -1067,7 +1067,8 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
} while (dst_pgd++, src_pgd++, addr = next, addr != end);
if (is_cow)
- mmu_notifier_invalidate_range_end(src_mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(src_mm, mmun_start, mmun_end,
+ MMU_COW);
return ret;
}
@@ -1373,10 +1374,10 @@ void unmap_vmas(struct mmu_gather *tlb,
{
struct mm_struct *mm = vma->vm_mm;
- mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
+ mmu_notifier_invalidate_range_start(mm, start_addr, end_addr, MMU_MUNMAP);
for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next)
unmap_single_vma(tlb, vma, start_addr, end_addr, NULL);
- mmu_notifier_invalidate_range_end(mm, start_addr, end_addr);
+ mmu_notifier_invalidate_range_end(mm, start_addr, end_addr, MMU_MUNMAP);
}
/**
@@ -1398,10 +1399,10 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long start,
lru_add_drain();
tlb_gather_mmu(&tlb, mm, start, end);
update_hiwater_rss(mm);
- mmu_notifier_invalidate_range_start(mm, start, end);
+ mmu_notifier_invalidate_range_start(mm, start, end, MMU_MUNMAP);
for ( ; vma && vma->vm_start < end; vma = vma->vm_next)
unmap_single_vma(&tlb, vma, start, end, details);
- mmu_notifier_invalidate_range_end(mm, start, end);
+ mmu_notifier_invalidate_range_end(mm, start, end, MMU_MUNMAP);
tlb_finish_mmu(&tlb, start, end);
}
@@ -1424,9 +1425,9 @@ static void zap_page_range_single(struct vm_area_struct *vma, unsigned long addr
lru_add_drain();
tlb_gather_mmu(&tlb, mm, address, end);
update_hiwater_rss(mm);
- mmu_notifier_invalidate_range_start(mm, address, end);
+ mmu_notifier_invalidate_range_start(mm, address, end, MMU_MUNMAP);
unmap_single_vma(&tlb, vma, address, end, details);
- mmu_notifier_invalidate_range_end(mm, address, end);
+ mmu_notifier_invalidate_range_end(mm, address, end, MMU_MUNMAP);
tlb_finish_mmu(&tlb, address, end);
}
@@ -2209,7 +2210,7 @@ gotten:
mmun_start = address & PAGE_MASK;
mmun_end = mmun_start + PAGE_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_FAULT_WP);
/*
* Re-check the pte - we dropped the lock
@@ -2239,7 +2240,7 @@ gotten:
* mmu page tables (such as kvm shadow page tables), we want the
* new page to be mapped directly into the secondary page table.
*/
- set_pte_at_notify(mm, address, page_table, entry);
+ set_pte_at_notify(mm, address, page_table, entry, MMU_FAULT_WP);
update_mmu_cache(vma, address, page_table);
if (old_page) {
/*
@@ -2278,7 +2279,7 @@ gotten:
unlock:
pte_unmap_unlock(page_table, ptl);
if (mmun_end > mmun_start)
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_FAULT_WP);
if (old_page) {
/*
* Don't let another task, with possibly unlocked vma,
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 8bc1199..156f34c 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -561,7 +561,7 @@ unsigned long change_prot_numa(struct vm_area_struct *vma,
{
int nr_updated;
- nr_updated = change_protection(vma, addr, end, vma->vm_page_prot, 0, 1);
+ nr_updated = change_protection(vma, addr, end, vma->vm_page_prot, 0, 1, 0);
if (nr_updated)
count_vm_numa_events(NUMA_PTE_UPDATES, nr_updated);
diff --git a/mm/migrate.c b/mm/migrate.c
index 63f0cd5..01cd98a 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1827,12 +1827,12 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
WARN_ON(PageLRU(new_page));
/* Recheck the target PMD */
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_MIGRATE);
ptl = pmd_lock(mm, pmd);
if (unlikely(!pmd_same(*pmd, entry) || page_count(page) != 2)) {
fail_putback:
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_MIGRATE);
/* Reverse changes made by migrate_page_copy() */
if (TestClearPageActive(new_page))
@@ -1898,7 +1898,7 @@ fail_putback:
*/
mem_cgroup_end_migration(memcg, page, new_page, true);
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_MIGRATE);
/* Take an "isolate" reference and put new page on the LRU. */
get_page(new_page);
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index 41cefdf..a906744 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -122,8 +122,10 @@ int __mmu_notifier_test_young(struct mm_struct *mm,
return young;
}
-void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
- pte_t pte)
+void __mmu_notifier_change_pte(struct mm_struct *mm,
+ unsigned long address,
+ pte_t pte,
+ enum mmu_action action)
{
struct mmu_notifier *mn;
int id;
@@ -131,13 +133,14 @@ void __mmu_notifier_change_pte(struct mm_struct *mm, unsigned long address,
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
if (mn->ops->change_pte)
- mn->ops->change_pte(mn, mm, address, pte);
+ mn->ops->change_pte(mn, mm, address, pte, action);
}
srcu_read_unlock(&srcu, id);
}
void __mmu_notifier_invalidate_page(struct mm_struct *mm,
- unsigned long address)
+ unsigned long address,
+ enum mmu_action action)
{
struct mmu_notifier *mn;
int id;
@@ -145,13 +148,16 @@ void __mmu_notifier_invalidate_page(struct mm_struct *mm,
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
if (mn->ops->invalidate_page)
- mn->ops->invalidate_page(mn, mm, address);
+ mn->ops->invalidate_page(mn, mm, address, action);
}
srcu_read_unlock(&srcu, id);
}
void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action)
+
{
struct mmu_notifier *mn;
int id;
@@ -159,14 +165,16 @@ void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
if (mn->ops->invalidate_range_start)
- mn->ops->invalidate_range_start(mn, mm, start, end);
+ mn->ops->invalidate_range_start(mn, mm, start, end, action);
}
srcu_read_unlock(&srcu, id);
}
EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range_start);
void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
- unsigned long start, unsigned long end)
+ unsigned long start,
+ unsigned long end,
+ enum mmu_action action)
{
struct mmu_notifier *mn;
int id;
@@ -174,7 +182,7 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
if (mn->ops->invalidate_range_end)
- mn->ops->invalidate_range_end(mn, mm, start, end);
+ mn->ops->invalidate_range_end(mn, mm, start, end, action);
}
srcu_read_unlock(&srcu, id);
}
diff --git a/mm/mprotect.c b/mm/mprotect.c
index c43d557..6c2846f 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -137,7 +137,8 @@ static unsigned long change_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
pud_t *pud, unsigned long addr, unsigned long end,
- pgprot_t newprot, int dirty_accountable, int prot_numa)
+ pgprot_t newprot, int dirty_accountable, int prot_numa,
+ enum mmu_action action)
{
pmd_t *pmd;
struct mm_struct *mm = vma->vm_mm;
@@ -157,7 +158,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
/* invoke the mmu notifier if the pmd is populated */
if (!mni_start) {
mni_start = addr;
- mmu_notifier_invalidate_range_start(mm, mni_start, end);
+ mmu_notifier_invalidate_range_start(mm, mni_start, end, action);
}
if (pmd_trans_huge(*pmd)) {
@@ -185,7 +186,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
} while (pmd++, addr = next, addr != end);
if (mni_start)
- mmu_notifier_invalidate_range_end(mm, mni_start, end);
+ mmu_notifier_invalidate_range_end(mm, mni_start, end, action);
if (nr_huge_updates)
count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates);
@@ -194,7 +195,8 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
static inline unsigned long change_pud_range(struct vm_area_struct *vma,
pgd_t *pgd, unsigned long addr, unsigned long end,
- pgprot_t newprot, int dirty_accountable, int prot_numa)
+ pgprot_t newprot, int dirty_accountable, int prot_numa,
+ enum mmu_action action)
{
pud_t *pud;
unsigned long next;
@@ -206,7 +208,7 @@ static inline unsigned long change_pud_range(struct vm_area_struct *vma,
if (pud_none_or_clear_bad(pud))
continue;
pages += change_pmd_range(vma, pud, addr, next, newprot,
- dirty_accountable, prot_numa);
+ dirty_accountable, prot_numa, action);
} while (pud++, addr = next, addr != end);
return pages;
@@ -214,7 +216,7 @@ static inline unsigned long change_pud_range(struct vm_area_struct *vma,
static unsigned long change_protection_range(struct vm_area_struct *vma,
unsigned long addr, unsigned long end, pgprot_t newprot,
- int dirty_accountable, int prot_numa)
+ int dirty_accountable, int prot_numa, enum mmu_action action)
{
struct mm_struct *mm = vma->vm_mm;
pgd_t *pgd;
@@ -231,7 +233,7 @@ static unsigned long change_protection_range(struct vm_area_struct *vma,
if (pgd_none_or_clear_bad(pgd))
continue;
pages += change_pud_range(vma, pgd, addr, next, newprot,
- dirty_accountable, prot_numa);
+ dirty_accountable, prot_numa, action);
} while (pgd++, addr = next, addr != end);
/* Only flush the TLB if we actually modified any entries: */
@@ -247,11 +249,21 @@ unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
int dirty_accountable, int prot_numa)
{
unsigned long pages;
+ enum mmu_action action = MMU_MPROT_NONE;
+
+ /* At this points vm_flags is updated. */
+ if ((vma->vm_flags & VM_READ) && (vma->vm_flags & VM_WRITE)) {
+ action = MMU_MPROT_RANDW;
+ } else if (vma->vm_flags & VM_WRITE) {
+ action = MMU_MPROT_WONLY;
+ } else if (vma->vm_flags & VM_READ) {
+ action = MMU_MPROT_RONLY;
+ }
if (is_vm_hugetlb_page(vma))
- pages = hugetlb_change_protection(vma, start, end, newprot);
+ pages = hugetlb_change_protection(vma, start, end, newprot, action);
else
- pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa);
+ pages = change_protection_range(vma, start, end, newprot, dirty_accountable, prot_numa, action);
return pages;
}
diff --git a/mm/mremap.c b/mm/mremap.c
index 05f1180..ceb8a47 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -177,7 +177,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
mmun_start = old_addr;
mmun_end = old_end;
- mmu_notifier_invalidate_range_start(vma->vm_mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(vma->vm_mm, mmun_start, mmun_end, MMU_MREMAP);
for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
cond_resched();
@@ -228,7 +228,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
if (likely(need_flush))
flush_tlb_range(vma, old_end-len, old_addr);
- mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end, MMU_MREMAP);
return len + old_addr - old_end; /* how much done */
}
diff --git a/mm/rmap.c b/mm/rmap.c
index ba6580d..3db669e 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -836,7 +836,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma,
pte_unmap_unlock(pte, ptl);
if (ret) {
- mmu_notifier_invalidate_page(mm, address);
+ mmu_notifier_invalidate_page(mm, address, MMU_FILE_WB);
(*cleaned)++;
}
out:
@@ -1144,6 +1144,15 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
spinlock_t *ptl;
int ret = SWAP_AGAIN;
enum ttu_flags flags = (enum ttu_flags)arg;
+ enum mmu_action action = MMU_VMSCAN;
+
+ if (flags & TTU_MIGRATION) {
+ action = MMU_MIGRATE;
+ } else if (flags & TTU_MUNLOCK) {
+ action = MMU_MUNLOCK;
+ } else if (unlikely(flags & TTU_POISON)) {
+ action = MMU_POISON;
+ }
pte = page_check_address(page, mm, address, &ptl, 0);
if (!pte)
@@ -1249,7 +1258,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
out_unmap:
pte_unmap_unlock(pte, ptl);
if (ret != SWAP_FAIL && !(flags & TTU_MUNLOCK))
- mmu_notifier_invalidate_page(mm, address);
+ mmu_notifier_invalidate_page(mm, address, action);
out:
return ret;
@@ -1303,7 +1312,8 @@ out_mlock:
#define CLUSTER_MASK (~(CLUSTER_SIZE - 1))
static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
- struct vm_area_struct *vma, struct page *check_page)
+ struct vm_area_struct *vma, struct page *check_page,
+ enum ttu_flags flags)
{
struct mm_struct *mm = vma->vm_mm;
pmd_t *pmd;
@@ -1317,6 +1327,15 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
unsigned long end;
int ret = SWAP_AGAIN;
int locked_vma = 0;
+ enum mmu_action action = MMU_VMSCAN;
+
+ if (flags & TTU_MIGRATION) {
+ action = MMU_MIGRATE;
+ } else if (flags & TTU_MUNLOCK) {
+ action = MMU_MUNLOCK;
+ } else if (unlikely(flags & TTU_POISON)) {
+ action = MMU_POISON;
+ }
address = (vma->vm_start + cursor) & CLUSTER_MASK;
end = address + CLUSTER_SIZE;
@@ -1331,7 +1350,7 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
mmun_start = address;
mmun_end = end;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, action);
/*
* If we can acquire the mmap_sem for read, and vma is VM_LOCKED,
@@ -1396,7 +1415,7 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
(*mapcount)--;
}
pte_unmap_unlock(pte - 1, ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end);
+ mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, action);
if (locked_vma)
up_read(&vma->vm_mm->mmap_sem);
return ret;
@@ -1452,7 +1471,7 @@ static int try_to_unmap_nonlinear(struct page *page,
while (cursor < max_nl_cursor &&
cursor < vma->vm_end - vma->vm_start) {
if (try_to_unmap_cluster(cursor, &mapcount,
- vma, page) == SWAP_MLOCK)
+ vma, page, (enum ttu_flags)arg) == SWAP_MLOCK)
ret = SWAP_MLOCK;
cursor += CLUSTER_SIZE;
vma->vm_private_data = (void *) cursor;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 4b6c01b..eb5a635 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -262,7 +262,8 @@ static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
struct mm_struct *mm,
- unsigned long address)
+ unsigned long address,
+ enum mmu_action action)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
int need_tlb_flush, idx;
@@ -301,7 +302,8 @@ static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long address,
- pte_t pte)
+ pte_t pte,
+ enum mmu_action action)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
int idx;
@@ -317,7 +319,8 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start,
- unsigned long end)
+ unsigned long end,
+ enum mmu_action action)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
int need_tlb_flush = 0, idx;
@@ -343,7 +346,8 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start,
- unsigned long end)
+ unsigned long end,
+ enum mmu_action action)
{
struct kvm *kvm = mmu_notifier_to_kvm(mn);
--
1.9.0
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH 3/5] mmu_notifier: pass through vma to invalidate_range and invalidate_page
2014-06-12 18:57 ` [PATCH 1/5] mm: differentiate unmap for vmscan from other unmap j.glisse
2014-06-12 18:57 ` [PATCH 2/5] mmu_notifier: add action information to address invalidation j.glisse
@ 2014-06-12 18:57 ` j.glisse
2014-06-12 18:57 ` [PATCH 4/5] hmm: heterogeneous memory management v2 j.glisse
2014-06-12 18:57 ` [PATCH 5/5] hmm/dummy: dummy driver to showcase the hmm api j.glisse
3 siblings, 0 replies; 5+ messages in thread
From: j.glisse @ 2014-06-12 18:57 UTC (permalink / raw)
To: akpm, linux-kernel, linux-mm; +Cc: Jérôme Glisse
From: Jérôme Glisse <jglisse@redhat.com>
New user of the mmu_notifier interface need to lookup vma in order to
perform the invalidation operation. Instead of redoing a vma lookup
inside the callback just pass through the vma from the call site where
it is already available.
This needs small refactoring in memory.c to call invalidate_range on
vma boundary the overhead should be low enough.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
---
drivers/gpu/drm/i915/i915_gem_userptr.c | 1 +
drivers/iommu/amd_iommu_v2.c | 3 +++
drivers/misc/sgi-gru/grutlbpurge.c | 6 +++++-
drivers/xen/gntdev.c | 4 +++-
fs/proc/task_mmu.c | 17 ++++++++++-----
include/linux/mmu_notifier.h | 18 +++++++++++++---
kernel/events/uprobes.c | 4 ++--
mm/filemap_xip.c | 2 +-
mm/huge_memory.c | 26 +++++++++++-----------
mm/hugetlb.c | 16 +++++++-------
mm/ksm.c | 8 +++----
mm/memory.c | 38 ++++++++++++++++++++++-----------
mm/migrate.c | 6 +++---
mm/mmu_notifier.c | 9 +++++---
mm/mprotect.c | 4 ++--
mm/mremap.c | 4 ++--
mm/rmap.c | 8 +++----
virt/kvm/kvm_main.c | 3 +++
18 files changed, 113 insertions(+), 64 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_gem_userptr.c b/drivers/gpu/drm/i915/i915_gem_userptr.c
index 7f7b4f3..70bae03 100644
--- a/drivers/gpu/drm/i915/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/i915_gem_userptr.c
@@ -55,6 +55,7 @@ struct i915_mmu_object {
static void i915_gem_userptr_mn_invalidate_range_start(struct mmu_notifier *_mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
diff --git a/drivers/iommu/amd_iommu_v2.c b/drivers/iommu/amd_iommu_v2.c
index 81ff80b..6f025a1 100644
--- a/drivers/iommu/amd_iommu_v2.c
+++ b/drivers/iommu/amd_iommu_v2.c
@@ -421,6 +421,7 @@ static void mn_change_pte(struct mmu_notifier *mn,
static void mn_invalidate_page(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long address,
enum mmu_action action)
{
@@ -429,6 +430,7 @@ static void mn_invalidate_page(struct mmu_notifier *mn,
static void mn_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
@@ -448,6 +450,7 @@ static void mn_invalidate_range_start(struct mmu_notifier *mn,
static void mn_invalidate_range_end(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
diff --git a/drivers/misc/sgi-gru/grutlbpurge.c b/drivers/misc/sgi-gru/grutlbpurge.c
index 3427bfc..716501b 100644
--- a/drivers/misc/sgi-gru/grutlbpurge.c
+++ b/drivers/misc/sgi-gru/grutlbpurge.c
@@ -221,6 +221,7 @@ void gru_flush_all_tlb(struct gru_state *gru)
*/
static void gru_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start, unsigned long end,
enum mmu_action action)
{
@@ -235,7 +236,9 @@ static void gru_invalidate_range_start(struct mmu_notifier *mn,
}
static void gru_invalidate_range_end(struct mmu_notifier *mn,
- struct mm_struct *mm, unsigned long start,
+ struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long start,
unsigned long end,
enum mmu_action action)
{
@@ -250,6 +253,7 @@ static void gru_invalidate_range_end(struct mmu_notifier *mn,
}
static void gru_invalidate_page(struct mmu_notifier *mn, struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long address,
enum mmu_action action)
{
diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
index 84aa5a7..447c3fb 100644
--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -428,6 +428,7 @@ static void unmap_if_in_range(struct grant_map *map,
static void mn_invl_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
@@ -447,10 +448,11 @@ static void mn_invl_range_start(struct mmu_notifier *mn,
static void mn_invl_page(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long address,
enum mmu_action action)
{
- mn_invl_range_start(mn, mm, address, address + PAGE_SIZE, action);
+ mn_invl_range_start(mn, mm, vma, address, address + PAGE_SIZE, action);
}
static void mn_release(struct mmu_notifier *mn,
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index fda2324..8b368f0 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -823,12 +823,19 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
.private = &cp,
};
down_read(&mm->mmap_sem);
- if (type == CLEAR_REFS_SOFT_DIRTY)
- mmu_notifier_invalidate_range_start(mm, 0, -1, MMU_SOFT_DIRTY);
- for (vma = mm->mmap; vma; vma = vma->vm_next)
+ for (vma = mm->mmap; vma; vma = vma->vm_next) {
+ if (type == CLEAR_REFS_SOFT_DIRTY)
+ mmu_notifier_invalidate_range_start(mm, vma,
+ vma->vm_start,
+ vma->vm_end,
+ MMU_SOFT_DIRTY);
walk_page_vma(vma, &clear_refs_walk);
- if (type == CLEAR_REFS_SOFT_DIRTY)
- mmu_notifier_invalidate_range_end(mm, 0, -1, MMU_SOFT_DIRTY);
+ if (type == CLEAR_REFS_SOFT_DIRTY)
+ mmu_notifier_invalidate_range_end(mm, vma,
+ vma->vm_start,
+ vma->vm_end,
+ MMU_SOFT_DIRTY);
+ }
flush_tlb_mm(mm);
up_read(&mm->mmap_sem);
mmput(mm);
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 90b9105..0794a73b 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -126,6 +126,7 @@ struct mmu_notifier_ops {
*/
void (*invalidate_page)(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long address,
enum mmu_action action);
@@ -174,11 +175,13 @@ struct mmu_notifier_ops {
*/
void (*invalidate_range_start)(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action);
void (*invalidate_range_end)(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action);
@@ -222,13 +225,16 @@ extern void __mmu_notifier_change_pte(struct mm_struct *mm,
pte_t pte,
enum mmu_action action);
extern void __mmu_notifier_invalidate_page(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long address,
enum mmu_action action);
extern void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action);
extern void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action);
@@ -265,29 +271,32 @@ static inline void mmu_notifier_change_pte(struct mm_struct *mm,
}
static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long address,
enum mmu_action action)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_invalidate_page(mm, address, action);
+ __mmu_notifier_invalidate_page(mm, vma, address, action);
}
static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_invalidate_range_start(mm, start, end, action);
+ __mmu_notifier_invalidate_range_start(mm, vma, start, end, action);
}
static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
{
if (mm_has_notifiers(mm))
- __mmu_notifier_invalidate_range_end(mm, start, end, action);
+ __mmu_notifier_invalidate_range_end(mm, vma, start, end, action);
}
static inline void mmu_notifier_mm_init(struct mm_struct *mm)
@@ -369,12 +378,14 @@ static inline void mmu_notifier_change_pte(struct mm_struct *mm,
}
static inline void mmu_notifier_invalidate_page(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long address,
enum mmu_action action)
{
}
static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
@@ -382,6 +393,7 @@ static inline void mmu_notifier_invalidate_range_start(struct mm_struct *mm,
}
static inline void mmu_notifier_invalidate_range_end(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
diff --git a/kernel/events/uprobes.c b/kernel/events/uprobes.c
index 3e2308f..a0459dd 100644
--- a/kernel/events/uprobes.c
+++ b/kernel/events/uprobes.c
@@ -171,7 +171,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
/* For try_to_free_swap() and munlock_vma_page() below */
lock_page(page);
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_UNMAP);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_UNMAP);
err = -EAGAIN;
ptep = page_check_address(page, mm, addr, &ptl, 0);
if (!ptep)
@@ -200,7 +200,7 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
err = 0;
unlock:
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_UNMAP);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_UNMAP);
unlock_page(page);
return err;
}
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index d529ab9..e01c68b 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -198,7 +198,7 @@ retry:
BUG_ON(pte_dirty(pteval));
pte_unmap_unlock(pte, ptl);
/* must invalidate_page _before_ freeing the page */
- mmu_notifier_invalidate_page(mm, address, MMU_UNMAP);
+ mmu_notifier_invalidate_page(mm, vma, address, MMU_UNMAP);
page_cache_release(page);
}
}
diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 4ad9b73..05688b0 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -993,7 +993,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
mmun_start = haddr;
mmun_end = haddr + HPAGE_PMD_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_THP_FAULT_WP);
ptl = pmd_lock(mm, pmd);
if (unlikely(!pmd_same(*pmd, orig_pmd)))
@@ -1023,7 +1023,7 @@ static int do_huge_pmd_wp_page_fallback(struct mm_struct *mm,
page_remove_rmap(page);
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_THP_FAULT_WP);
ret |= VM_FAULT_WRITE;
put_page(page);
@@ -1033,7 +1033,7 @@ out:
out_free_pages:
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_THP_FAULT_WP);
mem_cgroup_uncharge_start();
for (i = 0; i < HPAGE_PMD_NR; i++) {
mem_cgroup_uncharge_page(pages[i]);
@@ -1123,7 +1123,7 @@ alloc:
mmun_start = haddr;
mmun_end = haddr + HPAGE_PMD_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_THP_FAULT_WP);
spin_lock(ptl);
if (page)
@@ -1153,7 +1153,7 @@ alloc:
}
spin_unlock(ptl);
out_mn:
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_FAULT_WP);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_THP_FAULT_WP);
out:
return ret;
out_unlock:
@@ -1588,7 +1588,7 @@ static int __split_huge_page_splitting(struct page *page,
const unsigned long mmun_start = address;
const unsigned long mmun_end = address + HPAGE_PMD_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_THP_SPLIT);
pmd = page_check_address_pmd(page, mm, address,
PAGE_CHECK_ADDRESS_PMD_NOTSPLITTING_FLAG, &ptl);
if (pmd) {
@@ -1603,7 +1603,7 @@ static int __split_huge_page_splitting(struct page *page,
ret = 1;
spin_unlock(ptl);
}
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_THP_SPLIT);
return ret;
}
@@ -2402,7 +2402,7 @@ static void collapse_huge_page(struct mm_struct *mm,
mmun_start = address;
mmun_end = address + HPAGE_PMD_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_THP_SPLIT);
pmd_ptl = pmd_lock(mm, pmd); /* probably unnecessary */
/*
* After this gup_fast can't run anymore. This also removes
@@ -2412,7 +2412,7 @@ static void collapse_huge_page(struct mm_struct *mm,
*/
_pmd = pmdp_clear_flush(vma, address, pmd);
spin_unlock(pmd_ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_THP_SPLIT);
spin_lock(pte_ptl);
isolated = __collapse_huge_page_isolate(vma, address, pte);
@@ -2801,24 +2801,24 @@ void __split_huge_page_pmd(struct vm_area_struct *vma, unsigned long address,
mmun_start = haddr;
mmun_end = haddr + HPAGE_PMD_SIZE;
again:
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_THP_SPLIT);
ptl = pmd_lock(mm, pmd);
if (unlikely(!pmd_trans_huge(*pmd))) {
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_THP_SPLIT);
return;
}
if (is_huge_zero_pmd(*pmd)) {
__split_huge_zero_page_pmd(vma, haddr, pmd);
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_THP_SPLIT);
return;
}
page = pmd_page(*pmd);
VM_BUG_ON_PAGE(!page_count(page), page);
get_page(page);
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_THP_SPLIT);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_THP_SPLIT);
split_huge_page(page);
diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index bfb455e..0ab7b24 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2540,7 +2540,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
mmun_start = vma->vm_start;
mmun_end = vma->vm_end;
if (cow)
- mmu_notifier_invalidate_range_start(src, mmun_start, mmun_end, MMU_COW);
+ mmu_notifier_invalidate_range_start(src, vma, mmun_start, mmun_end, MMU_COW);
for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
spinlock_t *src_ptl, *dst_ptl;
@@ -2574,7 +2574,7 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
}
if (cow)
- mmu_notifier_invalidate_range_end(src, mmun_start, mmun_end, MMU_COW);
+ mmu_notifier_invalidate_range_end(src, vma, mmun_start, mmun_end, MMU_COW);
return ret;
}
@@ -2626,7 +2626,7 @@ void __unmap_hugepage_range(struct mmu_gather *tlb, struct vm_area_struct *vma,
BUG_ON(end & ~huge_page_mask(h));
tlb_start_vma(tlb, vma);
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_UNMAP);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_UNMAP);
again:
for (address = start; address < end; address += sz) {
ptep = huge_pte_offset(mm, address);
@@ -2697,7 +2697,7 @@ unlock:
if (address < end && !ref_page)
goto again;
}
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_UNMAP);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_UNMAP);
tlb_end_vma(tlb, vma);
}
@@ -2884,7 +2884,7 @@ retry_avoidcopy:
mmun_start = address & huge_page_mask(h);
mmun_end = mmun_start + huge_page_size(h);
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_UNMAP);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_UNMAP);
/*
* Retake the page table lock to check for racing updates
* before the page tables are altered
@@ -2904,7 +2904,7 @@ retry_avoidcopy:
new_page = old_page;
}
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_UNMAP);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_UNMAP);
page_cache_release(new_page);
page_cache_release(old_page);
@@ -3342,7 +3342,7 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
BUG_ON(address >= end);
flush_cache_range(vma, address, end);
- mmu_notifier_invalidate_range_start(mm, start, end, action);
+ mmu_notifier_invalidate_range_start(mm, vma, start, end, action);
mutex_lock(&vma->vm_file->f_mapping->i_mmap_mutex);
for (; address < end; address += huge_page_size(h)) {
spinlock_t *ptl;
@@ -3372,7 +3372,7 @@ unsigned long hugetlb_change_protection(struct vm_area_struct *vma,
*/
flush_tlb_range(vma, start, end);
mutex_unlock(&vma->vm_file->f_mapping->i_mmap_mutex);
- mmu_notifier_invalidate_range_end(mm, start, end, action);
+ mmu_notifier_invalidate_range_end(mm, vma, start, end, action);
return pages << h->order;
}
diff --git a/mm/ksm.c b/mm/ksm.c
index 6a32bc4..3752820 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -872,7 +872,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
mmun_start = addr;
mmun_end = addr + PAGE_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_KSM_RONLY);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_KSM_RONLY);
ptep = page_check_address(page, mm, addr, &ptl, 0);
if (!ptep)
@@ -912,7 +912,7 @@ static int write_protect_page(struct vm_area_struct *vma, struct page *page,
out_unlock:
pte_unmap_unlock(ptep, ptl);
out_mn:
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_KSM_RONLY);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_KSM_RONLY);
out:
return err;
}
@@ -949,7 +949,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
mmun_start = addr;
mmun_end = addr + PAGE_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_KSM);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_KSM);
ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
if (!pte_same(*ptep, orig_pte)) {
@@ -972,7 +972,7 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
pte_unmap_unlock(ptep, ptl);
err = 0;
out_mn:
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_KSM);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_KSM);
out:
return err;
}
diff --git a/mm/memory.c b/mm/memory.c
index 55d4e91..33f2028 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1049,7 +1049,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
mmun_start = addr;
mmun_end = end;
if (is_cow)
- mmu_notifier_invalidate_range_start(src_mm, mmun_start,
+ mmu_notifier_invalidate_range_start(src_mm, vma, mmun_start,
mmun_end, MMU_COW);
ret = 0;
@@ -1067,7 +1067,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
} while (dst_pgd++, src_pgd++, addr = next, addr != end);
if (is_cow)
- mmu_notifier_invalidate_range_end(src_mm, mmun_start, mmun_end,
+ mmu_notifier_invalidate_range_end(src_mm, vma, mmun_start, mmun_end,
MMU_COW);
return ret;
}
@@ -1374,10 +1374,17 @@ void unmap_vmas(struct mmu_gather *tlb,
{
struct mm_struct *mm = vma->vm_mm;
- mmu_notifier_invalidate_range_start(mm, start_addr, end_addr, MMU_MUNMAP);
- for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next)
+ for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) {
+ mmu_notifier_invalidate_range_start(mm, vma,
+ max(start_addr, vma->vm_start),
+ min(end_addr, vma->vm_end),
+ MMU_MUNMAP);
unmap_single_vma(tlb, vma, start_addr, end_addr, NULL);
- mmu_notifier_invalidate_range_end(mm, start_addr, end_addr, MMU_MUNMAP);
+ mmu_notifier_invalidate_range_end(mm, vma,
+ max(start_addr, vma->vm_start),
+ min(end_addr, vma->vm_end),
+ MMU_MUNMAP);
+ }
}
/**
@@ -1399,10 +1406,17 @@ void zap_page_range(struct vm_area_struct *vma, unsigned long start,
lru_add_drain();
tlb_gather_mmu(&tlb, mm, start, end);
update_hiwater_rss(mm);
- mmu_notifier_invalidate_range_start(mm, start, end, MMU_MUNMAP);
- for ( ; vma && vma->vm_start < end; vma = vma->vm_next)
+ for ( ; vma && vma->vm_start < end; vma = vma->vm_next) {
+ mmu_notifier_invalidate_range_start(mm, vma,
+ max(start, vma->vm_start),
+ min(end, vma->vm_end),
+ MMU_MUNMAP);
unmap_single_vma(&tlb, vma, start, end, details);
- mmu_notifier_invalidate_range_end(mm, start, end, MMU_MUNMAP);
+ mmu_notifier_invalidate_range_end(mm, vma,
+ max(start, vma->vm_start),
+ min(end, vma->vm_end),
+ MMU_MUNMAP);
+ }
tlb_finish_mmu(&tlb, start, end);
}
@@ -1425,9 +1439,9 @@ static void zap_page_range_single(struct vm_area_struct *vma, unsigned long addr
lru_add_drain();
tlb_gather_mmu(&tlb, mm, address, end);
update_hiwater_rss(mm);
- mmu_notifier_invalidate_range_start(mm, address, end, MMU_MUNMAP);
+ mmu_notifier_invalidate_range_start(mm, vma, address, end, MMU_MUNMAP);
unmap_single_vma(&tlb, vma, address, end, details);
- mmu_notifier_invalidate_range_end(mm, address, end, MMU_MUNMAP);
+ mmu_notifier_invalidate_range_end(mm, vma, address, end, MMU_MUNMAP);
tlb_finish_mmu(&tlb, address, end);
}
@@ -2210,7 +2224,7 @@ gotten:
mmun_start = address & PAGE_MASK;
mmun_end = mmun_start + PAGE_SIZE;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_FAULT_WP);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_FAULT_WP);
/*
* Re-check the pte - we dropped the lock
@@ -2279,7 +2293,7 @@ gotten:
unlock:
pte_unmap_unlock(page_table, ptl);
if (mmun_end > mmun_start)
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_FAULT_WP);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_FAULT_WP);
if (old_page) {
/*
* Don't let another task, with possibly unlocked vma,
diff --git a/mm/migrate.c b/mm/migrate.c
index 01cd98a..6b2797d 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1827,12 +1827,12 @@ int migrate_misplaced_transhuge_page(struct mm_struct *mm,
WARN_ON(PageLRU(new_page));
/* Recheck the target PMD */
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, MMU_MIGRATE);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, MMU_MIGRATE);
ptl = pmd_lock(mm, pmd);
if (unlikely(!pmd_same(*pmd, entry) || page_count(page) != 2)) {
fail_putback:
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_MIGRATE);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_MIGRATE);
/* Reverse changes made by migrate_page_copy() */
if (TestClearPageActive(new_page))
@@ -1898,7 +1898,7 @@ fail_putback:
*/
mem_cgroup_end_migration(memcg, page, new_page, true);
spin_unlock(ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, MMU_MIGRATE);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, MMU_MIGRATE);
/* Take an "isolate" reference and put new page on the LRU. */
get_page(new_page);
diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c
index a906744..0b0e1ca 100644
--- a/mm/mmu_notifier.c
+++ b/mm/mmu_notifier.c
@@ -139,6 +139,7 @@ void __mmu_notifier_change_pte(struct mm_struct *mm,
}
void __mmu_notifier_invalidate_page(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long address,
enum mmu_action action)
{
@@ -148,12 +149,13 @@ void __mmu_notifier_invalidate_page(struct mm_struct *mm,
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
if (mn->ops->invalidate_page)
- mn->ops->invalidate_page(mn, mm, address, action);
+ mn->ops->invalidate_page(mn, mm, vma, address, action);
}
srcu_read_unlock(&srcu, id);
}
void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
@@ -165,13 +167,14 @@ void __mmu_notifier_invalidate_range_start(struct mm_struct *mm,
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
if (mn->ops->invalidate_range_start)
- mn->ops->invalidate_range_start(mn, mm, start, end, action);
+ mn->ops->invalidate_range_start(mn, mm, vma, start, end, action);
}
srcu_read_unlock(&srcu, id);
}
EXPORT_SYMBOL_GPL(__mmu_notifier_invalidate_range_start);
void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
@@ -182,7 +185,7 @@ void __mmu_notifier_invalidate_range_end(struct mm_struct *mm,
id = srcu_read_lock(&srcu);
hlist_for_each_entry_rcu(mn, &mm->mmu_notifier_mm->list, hlist) {
if (mn->ops->invalidate_range_end)
- mn->ops->invalidate_range_end(mn, mm, start, end, action);
+ mn->ops->invalidate_range_end(mn, mm, vma, start, end, action);
}
srcu_read_unlock(&srcu, id);
}
diff --git a/mm/mprotect.c b/mm/mprotect.c
index 6c2846f..ebe92d1 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -158,7 +158,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
/* invoke the mmu notifier if the pmd is populated */
if (!mni_start) {
mni_start = addr;
- mmu_notifier_invalidate_range_start(mm, mni_start, end, action);
+ mmu_notifier_invalidate_range_start(mm, vma, mni_start, end, action);
}
if (pmd_trans_huge(*pmd)) {
@@ -186,7 +186,7 @@ static inline unsigned long change_pmd_range(struct vm_area_struct *vma,
} while (pmd++, addr = next, addr != end);
if (mni_start)
- mmu_notifier_invalidate_range_end(mm, mni_start, end, action);
+ mmu_notifier_invalidate_range_end(mm, vma, mni_start, end, action);
if (nr_huge_updates)
count_vm_numa_events(NUMA_HUGE_PTE_UPDATES, nr_huge_updates);
diff --git a/mm/mremap.c b/mm/mremap.c
index ceb8a47..0b008a0 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -177,7 +177,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
mmun_start = old_addr;
mmun_end = old_end;
- mmu_notifier_invalidate_range_start(vma->vm_mm, mmun_start, mmun_end, MMU_MREMAP);
+ mmu_notifier_invalidate_range_start(vma->vm_mm, vma, mmun_start, mmun_end, MMU_MREMAP);
for (; old_addr < old_end; old_addr += extent, new_addr += extent) {
cond_resched();
@@ -228,7 +228,7 @@ unsigned long move_page_tables(struct vm_area_struct *vma,
if (likely(need_flush))
flush_tlb_range(vma, old_end-len, old_addr);
- mmu_notifier_invalidate_range_end(vma->vm_mm, mmun_start, mmun_end, MMU_MREMAP);
+ mmu_notifier_invalidate_range_end(vma->vm_mm, vma, mmun_start, mmun_end, MMU_MREMAP);
return len + old_addr - old_end; /* how much done */
}
diff --git a/mm/rmap.c b/mm/rmap.c
index 3db669e..383970a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -836,7 +836,7 @@ static int page_mkclean_one(struct page *page, struct vm_area_struct *vma,
pte_unmap_unlock(pte, ptl);
if (ret) {
- mmu_notifier_invalidate_page(mm, address, MMU_FILE_WB);
+ mmu_notifier_invalidate_page(mm, vma, address, MMU_FILE_WB);
(*cleaned)++;
}
out:
@@ -1258,7 +1258,7 @@ static int try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
out_unmap:
pte_unmap_unlock(pte, ptl);
if (ret != SWAP_FAIL && !(flags & TTU_MUNLOCK))
- mmu_notifier_invalidate_page(mm, address, action);
+ mmu_notifier_invalidate_page(mm, vma, address, action);
out:
return ret;
@@ -1350,7 +1350,7 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
mmun_start = address;
mmun_end = end;
- mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end, action);
+ mmu_notifier_invalidate_range_start(mm, vma, mmun_start, mmun_end, action);
/*
* If we can acquire the mmap_sem for read, and vma is VM_LOCKED,
@@ -1415,7 +1415,7 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
(*mapcount)--;
}
pte_unmap_unlock(pte - 1, ptl);
- mmu_notifier_invalidate_range_end(mm, mmun_start, mmun_end, action);
+ mmu_notifier_invalidate_range_end(mm, vma, mmun_start, mmun_end, action);
if (locked_vma)
up_read(&vma->vm_mm->mmap_sem);
return ret;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index eb5a635..1bd7117 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -262,6 +262,7 @@ static inline struct kvm *mmu_notifier_to_kvm(struct mmu_notifier *mn)
static void kvm_mmu_notifier_invalidate_page(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long address,
enum mmu_action action)
{
@@ -318,6 +319,7 @@ static void kvm_mmu_notifier_change_pte(struct mmu_notifier *mn,
static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
@@ -345,6 +347,7 @@ static void kvm_mmu_notifier_invalidate_range_start(struct mmu_notifier *mn,
static void kvm_mmu_notifier_invalidate_range_end(struct mmu_notifier *mn,
struct mm_struct *mm,
+ struct vm_area_struct *vma,
unsigned long start,
unsigned long end,
enum mmu_action action)
--
1.9.0
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH 4/5] hmm: heterogeneous memory management v2
2014-06-12 18:57 ` [PATCH 1/5] mm: differentiate unmap for vmscan from other unmap j.glisse
2014-06-12 18:57 ` [PATCH 2/5] mmu_notifier: add action information to address invalidation j.glisse
2014-06-12 18:57 ` [PATCH 3/5] mmu_notifier: pass through vma to invalidate_range and invalidate_page j.glisse
@ 2014-06-12 18:57 ` j.glisse
2014-06-12 18:57 ` [PATCH 5/5] hmm/dummy: dummy driver to showcase the hmm api j.glisse
3 siblings, 0 replies; 5+ messages in thread
From: j.glisse @ 2014-06-12 18:57 UTC (permalink / raw)
To: akpm, linux-kernel, linux-mm
Cc: Jérôme Glisse, Sherry Cheung, Subhash Gutti,
Mark Hairgrove, John Hubbard, Jatin Kumar
From: Jérôme Glisse <jglisse@redhat.com>
Motivation:
Heterogeneous memory management is intended to allow a device to transparently
access a process address space without having to lock pages of the process or
take references on them. In other word mirroring a process address space while
allowing the regular memory management event such as page reclamation or page
migration, to happen seamlessly.
Recent years have seen a surge into the number of specialized devices that are
part of a computer platform (from desktop to phone). So far each of those
devices have operated on there own private address space that is not link or
expose to the process address space that is using them. This separation often
leads to multiple memory copy happening between the device owned memory and the
process memory. This of course is both a waste of cpu cycle and memory.
Over the last few years most of those devices have gained a full mmu allowing
them to support multiple page table, page fault and other features that are
found inside cpu mmu. There is now a strong incentive to start leveraging
capabilities of such devices and to start sharing process address to avoid
any unnecessary memory copy as well as simplifying the programming model of
those devices by sharing an unique and common address space with the process
that use them.
The aim of the heterogeneous memory management is to provide a common API that
can be use by any such devices in order to mirror process address. The hmm code
provide an unique entry point and interface itself with the core mm code of the
linux kernel avoiding duplicate implementation and shielding device driver code
from core mm code.
Moreover, hmm also intend to provide support for migrating memory to device
private memory, allowing device to work on its own fast local memory. The hmm
code would be responsible to intercept cpu page fault on migrated range of and
to migrate it back to system memory allowing cpu to resume its access to the
memory.
Another feature hmm intend to provide is support for atomic operation for the
device even if the bus linking the device and the cpu do not have any such
capabilities.
We expect that graphic processing unit and network interface to be among the
first users of such api.
Hardware requirement:
Because hmm is intended to be use by device driver there are minimum features
requirement for the hardware mmu :
- hardware have its own page table per process (can be share btw != devices)
- hardware mmu support page fault and suspend execution until the page fault
is serviced by hmm code. The page fault must also trigger some form of
interrupt so that hmm code can be call by the device driver.
- hardware must support at least read only mapping (otherwise it can not
access read only range of the process address space).
For better memory management it is highly recommanded that the device also
support the following features :
- hardware mmu set access bit in its page table on memory access (like cpu).
- hardware page table can be updated from cpu or through a fast path.
- hardware provide advanced statistic over which range of memory it access
the most.
- hardware differentiate atomic memory access from regular access allowing
to support atomic operation even on platform that do not have atomic
support with there bus link with the device.
Implementation:
The hmm layer provide a simple API to the device driver. Each device driver
have to register and hmm device that holds pointer to all the callback the hmm
code will make to synchronize the device page table with the cpu page table of
a given process.
For each process it wants to mirror the device driver must register a mirror
hmm structure that holds all the informations specific to the process being
mirrored. Each hmm mirror uniquely link an hmm device with a process address
space (the mm struct).
This design allow several different device driver to mirror concurrently the
same process. The hmm layer will dispatch approprietly to each device driver
modification that are happening to the process address space.
The hmm layer rely on the mmu notifier api to monitor change to the process
address space. Because update to device page table can have unbound completion
time, the hmm layer need the capability to sleep during mmu notifier callback.
This patch only implement the core of the hmm layer and do not support feature
such as migration to device memory.
Change since v1:
- convert fence to refcounted object
- change the api to provide pte value directly avoiding useless temporary
special hmm pfn value
- cleanups & fixes ...
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
Signed-off-by: Sherry Cheung <SCheung@nvidia.com>
Signed-off-by: Subhash Gutti <sgutti@nvidia.com>
Signed-off-by: Mark Hairgrove <mhairgrove@nvidia.com>
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Jatin Kumar <jakumar@nvidia.com>
---
include/linux/hmm.h | 435 +++++++++++++++++++
include/linux/mm.h | 14 +
include/linux/mm_types.h | 14 +
kernel/fork.c | 6 +
mm/Kconfig | 12 +
mm/Makefile | 1 +
mm/hmm.c | 1078 ++++++++++++++++++++++++++++++++++++++++++++++
7 files changed, 1560 insertions(+)
create mode 100644 include/linux/hmm.h
create mode 100644 mm/hmm.c
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
new file mode 100644
index 0000000..6c96920
--- /dev/null
+++ b/include/linux/hmm.h
@@ -0,0 +1,435 @@
+/*
+ * Copyright 2013 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Authors: Jérôme Glisse <jglisse@redhat.com>
+ */
+/* This is a heterogeneous memory management (hmm). In a nutshell this provide
+ * an API to mirror a process address on a device which has its own mmu and its
+ * own page table for the process. It supports everything except special/mixed
+ * vma.
+ *
+ * To use this the hardware must have :
+ * - mmu with pagetable
+ * - pagetable must support read only (supporting dirtyness accounting is
+ * preferable but is not mandatory).
+ * - support pagefault ie hardware thread should stop on fault and resume
+ * once hmm has provided valid memory to use.
+ * - some way to report fault.
+ *
+ * The hmm code handle all the interfacing with the core kernel mm code and
+ * provide a simple API. It does support migrating system memory to device
+ * memory and handle migration back to system memory on cpu page fault.
+ *
+ * Migrated memory is considered as swaped from cpu and core mm code point of
+ * view.
+ */
+#ifndef _HMM_H
+#define _HMM_H
+
+#ifdef CONFIG_HMM
+
+#include <linux/list.h>
+#include <linux/rwsem.h>
+#include <linux/spinlock.h>
+#include <linux/atomic.h>
+#include <linux/mm_types.h>
+#include <linux/mmu_notifier.h>
+#include <linux/swap.h>
+#include <linux/kref.h>
+#include <linux/swapops.h>
+#include <linux/mman.h>
+
+
+struct hmm_device;
+struct hmm_device_ops;
+struct hmm_mirror;
+struct hmm_event;
+struct hmm;
+
+
+/* hmm_fence - device driver fence to wait for device driver operations.
+ *
+ * In order to concurrently update several different devices mmu the hmm rely
+ * on device driver fence to wait for operation hmm schedules to complete on
+ * devices. It is strongly recommanded to implement fences and have the hmm
+ * callback do as little as possible (just scheduling the update and returning
+ * a fence). Moreover the hmm code will reschedule for i/o the current process
+ * if necessary once it has scheduled all updates on all devices.
+ *
+ * Each fence is created as a result of either an update to range of memory or
+ * for remote memory to/from local memory dma.
+ *
+ * Update to range of memory correspond to a specific event type. For instance
+ * range of memory is unmap for page reclamation, or range of memory is unmap
+ * from process address space as result of munmap syscall (HMM_MUNMAP), or a
+ * memory protection change on the range. There is one hmm_etype for each of
+ * those event allowing the device driver to take appropriate action like for
+ * instance freeing device page table on HMM_MUNMAP but keeping it when it is
+ * just an access protection change or temporary unmap.
+ */
+enum hmm_etype {
+ HMM_NONE = 0,
+ HMM_UNREGISTER,
+ HMM_MPROT_RONLY,
+ HMM_MPROT_NONE,
+ HMM_COW,
+ HMM_MUNMAP,
+ HMM_RFAULT,
+ HMM_WFAULT,
+};
+
+struct hmm_fence {
+ struct kref kref;
+ struct hmm_mirror *mirror;
+ struct list_head list;
+};
+
+/* struct hmm_event - used to serialize change to overlapping range of address.
+ *
+ * @list: List of pending|in progress event.
+ * @faddr: First address (inclusive) for the range this event affect.
+ * @laddr: Last address (exclusive) for the range this event affect.
+ * @iaddr: First invalid address.
+ * @fences: List of device fences associated with this event.
+ * @etype: Event type (munmap, migrate, truncate, ...).
+ * @backoff: Should this event backoff ie a new event render it obsolete.
+ */
+struct hmm_event {
+ struct list_head list;
+ unsigned long faddr;
+ unsigned long laddr;
+ unsigned long iaddr;
+ struct list_head fences;
+ enum hmm_etype etype;
+ bool backoff;
+};
+
+
+
+
+/* hmm_device - Each device driver must register one and only one hmm_device.
+ *
+ * The hmm_device is the link btw hmm and each device driver.
+ */
+
+/* struct hmm_device_operations - hmm device operation callback
+ */
+struct hmm_device_ops {
+ /* device_destroy - free hmm_device (call when refcount drop to 0).
+ *
+ * @device: The device hmm specific structure.
+ */
+ void (*device_destroy)(struct hmm_device *device);
+
+ /* mirror_release() - device must stop using the address space.
+ *
+ * @mirror: The mirror that link process address space with the device.
+ *
+ * Called when as result of hmm_mirror_unregister or when mm is being
+ * destroy.
+ *
+ * It's illegal for the device to call any hmm helper function after
+ * this call back. The device driver must kill any pending device
+ * thread and wait for completion of all of them.
+ *
+ * Note that even after this callback returns the device driver might
+ * get call back from hmm. Callback will stop only once mirror_destroy
+ * is call.
+ */
+ void (*mirror_release)(struct hmm_mirror *hmm_mirror);
+
+ /* mirror_destroy - free hmm_mirror (call when refcount drop to 0).
+ *
+ * @mirror: The mirror that link process address space with the device.
+ */
+ void (*mirror_destroy)(struct hmm_mirror *mirror);
+
+ /* fence_wait() - to wait on device driver fence.
+ *
+ * @fence: The device driver fence struct.
+ * Returns: 0 on success,-EIO on error, -EAGAIN to wait again.
+ *
+ * Called when hmm want to wait for all operations associated with a
+ * fence to complete (including device cache flush if the event mandate
+ * it).
+ *
+ * Device driver must free fence and associated resources if it returns
+ * something else thant -EAGAIN. On -EAGAIN the fence must not be free
+ * as hmm will call back again.
+ *
+ * Return error if scheduled operation failed or if need to wait again.
+ * -EIO Some input/output error with the device.
+ * -EAGAIN The fence not yet signaled, hmm reschedule waiting thread.
+ *
+ * All other return value trigger warning and are transformed to -EIO.
+ */
+ int (*fence_wait)(struct hmm_fence *fence);
+
+ /* fence_destroy() - destroy fence structure.
+ *
+ * @fence: Fence structure to destroy.
+ *
+ * Called when all reference on a fence are gone.
+ */
+ void (*fence_destroy)(struct hmm_fence *fence);
+
+ /* update() - update device mmu for a range of address.
+ *
+ * @mirror: The mirror that link process address space with the device.
+ * @vma: The vma into which the update is taking place.
+ * @faddr: First address in range (inclusive).
+ * @laddr: Last address in range (exclusive).
+ * @etype: The type of memory event (unmap, read only, ...).
+ * Returns: Valid fence ptr or NULL on success otherwise ERR_PTR.
+ *
+ * Called to update device mmu permission/usage for a range of address.
+ * The event type provide the nature of the update :
+ * - range is no longer valid (munmap).
+ * - range protection changes (mprotect, COW, ...).
+ * - range is unmapped (swap, reclaim, page migration, ...).
+ * - ...
+ *
+ * Any event that block further write to the memory must also trigger a
+ * device cache flush and everything has to be flush to local memory by
+ * the time the wait callback return (if this callback returned a fence
+ * otherwise everything must be flush by the time the callback return).
+ *
+ * Device must properly call set_page_dirty on any page the device did
+ * write to since last call to update.
+ *
+ * The driver should return a fence pointer or NULL on success. Device
+ * driver should return fence and delay wait for the operation to the
+ * febce wait callback. Returning a fence allow hmm to batch update to
+ * several devices and delay wait on those once they all have scheduled
+ * the update.
+ *
+ * Device driver must not fail lightly, any failure result in device
+ * process being kill.
+ *
+ * Return fence or NULL on success, error value otherwise :
+ * -ENOMEM Not enough memory for performing the operation.
+ * -EIO Some input/output error with the device.
+ *
+ * All other return value trigger warning and are transformed to -EIO.
+ */
+ struct hmm_fence *(*update)(struct hmm_mirror *mirror,
+ struct vm_area_struct *vma,
+ unsigned long faddr,
+ unsigned long laddr,
+ enum hmm_etype etype);
+
+ /* fault() - fault range of address on the device mmu.
+ *
+ * @mirror: The mirror that link process address space with the device.
+ * @faddr: First address in range (inclusive).
+ * @laddr: Last address in range (exclusive).
+ * @pfns: Array of pfn for the range (each of the pfn is valid).
+ * @fault: The fault structure provided by device driver.
+ * Returns: 0 on success, error value otherwise.
+ *
+ * Called to give the device driver each of the pfn backing a range of
+ * address. It is only call as a result of a call to hmm_mirror_fault.
+ *
+ * Note that the pfns array content is only valid for the duration of
+ * the callback. Once the device driver callback return further memory
+ * activities might invalidate the value of the pfns array. The device
+ * driver will be inform of such changes through the update callback.
+ *
+ * Allowed return value are :
+ * -ENOMEM Not enough memory for performing the operation.
+ * -EIO Some input/output error with the device.
+ *
+ * Device driver must not fail lightly, any failure result in device
+ * process being kill.
+ *
+ * Return error if scheduled operation failed. Valid value :
+ * -ENOMEM Not enough memory for performing the operation.
+ * -EIO Some input/output error with the device.
+ *
+ * All other return value trigger warning and are transformed to -EIO.
+ */
+ int (*fault)(struct hmm_mirror *mirror,
+ unsigned long faddr,
+ unsigned long laddr,
+ pte_t *ptep,
+ struct hmm_event *event);
+};
+
+
+
+
+/* struct hmm_device - per device hmm structure
+ *
+ * @kref: Reference count.
+ * @mirrors: List of all active mirrors for the device.
+ * @mutex: Mutex protecting mirrors list.
+ * @name: Device name (uniquely identify the device on the system).
+ * @ops: The hmm operations callback.
+ * @fuid: First uid assigned to this device (inclusive).
+ * @luid: Last uid assigned to this device (exclusive).
+ * @rpages: Array of rpage.
+ * @wait_queue: Wait queue for remote memory operations.
+ *
+ * Each device that want to mirror an address space must register one of this
+ * struct (only once).
+ */
+struct hmm_device {
+ struct kref kref;
+ struct list_head mirrors;
+ struct mutex mutex;
+ const char *name;
+ const struct hmm_device_ops *ops;
+ wait_queue_head_t wait_queue;
+};
+
+/* hmm_device_register() - register a device with hmm.
+ *
+ * @device: The hmm_device struct.
+ * @name: Unique name string for the device (use in error messages).
+ * Returns: 0 on success, -EINVAL otherwise.
+ *
+ * Call when device driver want to register itself with hmm. Device driver can
+ * only register once. It will return a reference on the device thus to release
+ * a device the driver must unreference the device.
+ */
+int hmm_device_register(struct hmm_device *device,
+ const char *name);
+
+struct hmm_device *hmm_device_ref(struct hmm_device *device);
+struct hmm_device *hmm_device_unref(struct hmm_device *device);
+
+
+
+
+/* hmm_mirror - device specific mirroring functions.
+ *
+ * Each device that mirror a process has a uniq hmm_mirror struct associating
+ * the process address space with the device. A process can be mirrored by
+ * several different devices at the same time.
+ */
+
+/* struct hmm_mirror - per device and per mm hmm structure
+ *
+ * @kref: Reference count.
+ * @dlist: List of all hmm_mirror for same device.
+ * @mlist: List of all hmm_mirror for same mm.
+ * @device: The hmm_device struct this hmm_mirror is associated to.
+ * @hmm: The hmm struct this hmm_mirror is associated to.
+ * @dead: The hmm_mirror is dead and should no longer be use.
+ *
+ * Each device that want to mirror an address space must register one of this
+ * struct for each of the address space it wants to mirror. Same device can
+ * mirror several different address space. As well same address space can be
+ * mirror by different devices.
+ */
+struct hmm_mirror {
+ struct kref kref;
+ struct list_head dlist;
+ struct list_head mlist;
+ struct hmm_device *device;
+ struct hmm *hmm;
+ bool dead;
+};
+
+/* hmm_mirror_register() - register a device mirror against an mm struct
+ *
+ * @mirror: The mirror that link process address space with the device.
+ * @device: The device struct to associate this mirror with.
+ * @mm: The mm struct of the process.
+ * Returns: 0 success, -ENOMEM, -EBUSY or -EINVAL if process already mirrored.
+ *
+ * Call when device driver want to start mirroring a process address space. The
+ * hmm shim will register mmu_notifier and start monitoring process address
+ * space changes. Hence callback to device driver might happen even before this
+ * function return.
+ *
+ * The mm pin must also be hold (either task is current or using get_task_mm).
+ *
+ * Only one mirror per mm and hmm_device can be created, it will return -EINVAL
+ * if the hmm_device already has an hmm_mirror for the the mm.
+ *
+ * If the mm or previous hmm is in transient state then this will return -EBUSY
+ * and device driver must retry the call after unpinning the mm and checking
+ * again that the mm is valid.
+ *
+ * On success the mirror is returned with one reference for the caller, thus to
+ * release mirror call hmm_mirror_unref.
+ */
+int hmm_mirror_register(struct hmm_mirror *mirror,
+ struct hmm_device *device,
+ struct mm_struct *mm);
+
+/* hmm_mirror_unregister() - unregister an hmm_mirror.
+ *
+ * @mirror: The mirror that link process address space with the device.
+ *
+ * Call when device driver want to stop mirroring a process address space.
+ */
+void hmm_mirror_unregister(struct hmm_mirror *mirror);
+
+/* hmm_mirror_fault() - call by the device driver on device memory fault.
+ *
+ * @mirror: Mirror linking process address space with the device.
+ * @event: Event describing the fault.
+ *
+ * Device driver call this function either if it needs to fill its page table
+ * for a range of address or if it needs to migrate memory between system and
+ * remote memory.
+ *
+ * This function perform vma lookup and access permission check on behalf of
+ * the device. If device ask for range [A; D] but there is only a valid vma
+ * starting at B with B > A then callback will return -EFAULT and update range
+ * to [A; B] so device driver can either report an issue back or recall again
+ * the hmm_mirror_fault with updated range to [B; D].
+ *
+ * This allows device driver to optimistically fault range of address without
+ * having to know about valid vma range. Device driver can then take proper
+ * action if a real memory access happen inside an invalid address range.
+ *
+ * Also the fault will clamp the requested range to valid vma range (unless the
+ * vma into which event->faddr falls to, can grow). So in previous example if D
+ * D is not cover by any vma then hmm_mirror_fault will stop a C with C < D and
+ * C being the last address of a valid vma.
+ *
+ * All error must be handled by device driver and most likely result in the
+ * process device tasks to be kill by the device driver.
+ *
+ * Returns:
+ * > 0 Number of pages faulted.
+ * -EINVAL if invalid argument.
+ * -ENOMEM if failing to allocate memory.
+ * -EACCES if trying to write to read only address.
+ * -EFAULT if trying to access an invalid address.
+ * -ENODEV if mirror is in process of being destroy.
+ */
+int hmm_mirror_fault(struct hmm_mirror *mirror,
+ struct hmm_event *event);
+
+struct hmm_mirror *hmm_mirror_ref(struct hmm_mirror *mirror);
+struct hmm_mirror *hmm_mirror_unref(struct hmm_mirror *mirror);
+
+static inline struct page *hmm_pte_to_page(pte_t pte, bool *write)
+{
+ if (pte_none(pte) || !pte_present(pte)) {
+ return NULL;
+ }
+ *write = pte_write(pte);
+ return pfn_to_page(pte_pfn(pte));
+}
+
+#endif /* CONFIG_HMM */
+#endif
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 5ac1cea..d7fc593 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2125,5 +2125,19 @@ void __init setup_nr_node_ids(void);
static inline void setup_nr_node_ids(void) {}
#endif
+#ifdef CONFIG_HMM
+void __hmm_destroy(struct mm_struct *mm);
+static inline void hmm_destroy(struct mm_struct *mm)
+{
+ if (mm->hmm) {
+ __hmm_destroy(mm);
+ }
+}
+#else /* !CONFIG_HMM */
+static inline void hmm_destroy(struct mm_struct *mm)
+{
+}
+#endif /* !CONFIG_HMM */
+
#endif /* __KERNEL__ */
#endif /* _LINUX_MM_H */
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index 96c5750..37eb293 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -16,6 +16,10 @@
#include <asm/page.h>
#include <asm/mmu.h>
+#ifdef CONFIG_HMM
+struct hmm;
+#endif
+
#ifndef AT_VECTOR_SIZE_ARCH
#define AT_VECTOR_SIZE_ARCH 0
#endif
@@ -425,6 +429,16 @@ struct mm_struct {
#ifdef CONFIG_MMU_NOTIFIER
struct mmu_notifier_mm *mmu_notifier_mm;
#endif
+#ifdef CONFIG_HMM
+ /*
+ * hmm always register an mmu_notifier we rely on mmu notifier to keep
+ * refcount on mm struct as well as forbiding registering hmm on a
+ * dying mm
+ *
+ * This field is set with mmap_sem old in write mode.
+ */
+ struct hmm *hmm;
+#endif
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
pgtable_t pmd_huge_pte; /* protected by page_table_lock */
#endif
diff --git a/kernel/fork.c b/kernel/fork.c
index d2799d1..9463eeb 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -27,6 +27,7 @@
#include <linux/binfmts.h>
#include <linux/mman.h>
#include <linux/mmu_notifier.h>
+#include <linux/hmm.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/vmacache.h>
@@ -602,6 +603,8 @@ void __mmdrop(struct mm_struct *mm)
mm_free_pgd(mm);
destroy_context(mm);
mmu_notifier_mm_destroy(mm);
+ /* hmm_destroy needs to be call after mmu_notifier_mm_destroy */
+ hmm_destroy(mm);
check_mm(mm);
free_mm(mm);
}
@@ -820,6 +823,9 @@ static struct mm_struct *dup_mm(struct task_struct *tsk)
memcpy(mm, oldmm, sizeof(*mm));
mm_init_cpumask(mm);
+#ifdef CONFIG_HMM
+ mm->hmm = NULL;
+#endif
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
mm->pmd_huge_pte = NULL;
diff --git a/mm/Kconfig b/mm/Kconfig
index 3e9977a..53be52b 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -592,3 +592,15 @@ config MAX_STACK_SIZE_MB
changed to a smaller value in which case that is used.
A sane initial value is 80 MB.
+
+config HMM
+ bool "Enable heterogeneous memory management (HMM)"
+ depends on MMU
+ select MMU_NOTIFIER
+ default n
+ help
+ Heterogeneous memory management provide infrastructure for a device
+ to mirror a process address space into an hardware mmu or into any
+ things supporting pagefault like event.
+
+ If unsure, say N to disable hmm.
diff --git a/mm/Makefile b/mm/Makefile
index 1eaa70b..09b9f83 100644
--- a/mm/Makefile
+++ b/mm/Makefile
@@ -62,3 +62,4 @@ obj-$(CONFIG_MEMORY_ISOLATION) += page_isolation.o
obj-$(CONFIG_ZBUD) += zbud.o
obj-$(CONFIG_ZSMALLOC) += zsmalloc.o
obj-$(CONFIG_GENERIC_EARLY_IOREMAP) += early_ioremap.o
+obj-$(CONFIG_HMM) += hmm.o
diff --git a/mm/hmm.c b/mm/hmm.c
new file mode 100644
index 0000000..62f73d4
--- /dev/null
+++ b/mm/hmm.c
@@ -0,0 +1,1078 @@
+/*
+ * Copyright 2013 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Authors: Jérôme Glisse <jglisse@redhat.com>
+ */
+/* This is the core code for heterogeneous memory management (HMM). HMM intend
+ * to provide helper for mirroring a process address space on a device as well
+ * as allowing migration of data between local memory and device memory.
+ *
+ * Refer to include/linux/hmm.h for further informations on general design.
+ */
+/* Locking :
+ *
+ * To synchronize with various mm event there is a simple serialization of
+ * event touching overlapping range of address. Each mm event is associated
+ * with an hmm_event structure which store the address range of the event.
+ *
+ * When a new mm event call in hmm (most call comes through the mmu_notifier
+ * call backs) hmm allocate an hmm_event structure and wait for all pending
+ * event that overlap with the new event.
+ *
+ * To avoid deadlock with mmap_sem the rules it to always allocate new hmm
+ * event after taking the mmap_sem lock. In case of mmu_notifier call we do
+ * not take the mmap_sem lock as if it was needed it would have been taken
+ * by the caller of the mmu_notifier API.
+ *
+ * Hence hmm only need to make sure to allocate new hmm event after taking
+ * the mmap_sem.
+ */
+#include <linux/export.h>
+#include <linux/bitmap.h>
+#include <linux/srcu.h>
+#include <linux/rculist.h>
+#include <linux/slab.h>
+#include <linux/mmu_notifier.h>
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/ksm.h>
+#include <linux/rmap.h>
+#include <linux/swap.h>
+#include <linux/swapops.h>
+#include <linux/mmu_context.h>
+#include <linux/memcontrol.h>
+#include <linux/hmm.h>
+#include <linux/wait.h>
+#include <linux/mman.h>
+#include <asm/tlb.h>
+#include <asm/tlbflush.h>
+#include <linux/delay.h>
+
+#include "internal.h"
+
+#define HMM_MAX_EVENTS 16
+
+/* global SRCU for all MMs */
+static struct srcu_struct srcu;
+
+
+
+
+/* struct hmm - per mm_struct hmm structure
+ *
+ * @mm: The mm struct.
+ * @kref: Reference counter
+ * @lock: Serialize the mirror list modifications.
+ * @pending: List of pending event (hmm_event).
+ * @mirrors: List of all mirror for this mm (one per device).
+ * @mmu_notifier: The mmu_notifier of this mm.
+ * @wait_queue: Wait queue for event synchronization.
+ * @events: Preallocated array of hmm_event for mmu_notifier.
+ * @nevents: Number of preallocated event currently in use.
+ * @dead: The mm is being destroy.
+ *
+ * For each process address space (mm_struct) there is one and only one hmm
+ * struct. hmm functions will redispatch to each devices the change into the
+ * process address space.
+ */
+struct hmm {
+ struct mm_struct *mm;
+ struct kref kref;
+ spinlock_t lock;
+ struct list_head pending;
+ struct list_head mirrors;
+ struct mmu_notifier mmu_notifier;
+ wait_queue_head_t wait_queue;
+ struct hmm_event events[HMM_MAX_EVENTS];
+ int nevents;
+ bool dead;
+};
+
+static struct mmu_notifier_ops hmm_notifier_ops;
+
+static inline struct hmm *hmm_ref(struct hmm *hmm);
+static inline struct hmm *hmm_unref(struct hmm *hmm);
+
+static void hmm_mirror_cleanup(struct hmm_mirror *mirror);
+
+static int hmm_device_fence_wait(struct hmm_device *device,
+ struct hmm_fence *fence);
+
+
+
+
+/* hmm_event - use to synchronize various mm events with each others.
+ *
+ * During life time of process various mm events will happen, hmm serialize
+ * event that affect overlapping range of address. The hmm_event are use for
+ * that purpose.
+ */
+
+static inline bool hmm_event_overlap(struct hmm_event *a, struct hmm_event *b)
+{
+ return !((a->laddr <= b->faddr) || (a->faddr >= b->laddr));
+}
+
+static inline unsigned long hmm_event_size(struct hmm_event *event)
+{
+ return (event->laddr - event->faddr);
+}
+
+struct hmm_fence *hmm_fence_ref(struct hmm_fence *fence)
+{
+ if (fence) {
+ kref_get(&fence->kref);
+ return fence;
+ }
+ return NULL;
+}
+
+static void hmm_fence_destroy(struct kref *kref)
+{
+ struct hmm_device *device;
+ struct hmm_fence *fence;
+
+ fence = container_of(kref, struct hmm_fence, kref);
+ device = fence->mirror->device;
+ device->ops->fence_destroy(fence);
+}
+
+struct hmm_fence *hmm_fence_unref(struct hmm_fence *fence)
+{
+ if (fence) {
+ kref_put(&fence->kref, hmm_fence_destroy);
+ }
+ return NULL;
+}
+
+
+
+
+/* hmm - core hmm functions.
+ *
+ * Core hmm functions that deal with all the process mm activities and use
+ * event for synchronization. Those function are use mostly as result of cpu
+ * mm event.
+ */
+
+static int hmm_init(struct hmm *hmm, struct mm_struct *mm)
+{
+ int i, ret;
+
+ hmm->mm = mm;
+ kref_init(&hmm->kref);
+ INIT_LIST_HEAD(&hmm->mirrors);
+ INIT_LIST_HEAD(&hmm->pending);
+ spin_lock_init(&hmm->lock);
+ init_waitqueue_head(&hmm->wait_queue);
+
+ for (i = 0; i < HMM_MAX_EVENTS; ++i) {
+ hmm->events[i].etype = HMM_NONE;
+ INIT_LIST_HEAD(&hmm->events[i].fences);
+ }
+
+ /* register notifier */
+ hmm->mmu_notifier.ops = &hmm_notifier_ops;
+ ret = __mmu_notifier_register(&hmm->mmu_notifier, mm);
+ return ret;
+}
+
+static enum hmm_etype hmm_event_mmu(enum mmu_action action)
+{
+ switch (action) {
+ case MMU_MPROT_RONLY:
+ return HMM_MPROT_RONLY;
+ case MMU_COW:
+ return HMM_COW;
+ case MMU_MPROT_WONLY:
+ case MMU_MPROT_NONE:
+ case MMU_KSM:
+ case MMU_KSM_RONLY:
+ case MMU_UNMAP:
+ case MMU_VMSCAN:
+ case MMU_MIGRATE:
+ case MMU_FILE_WB:
+ case MMU_FAULT_WP:
+ case MMU_THP_SPLIT:
+ case MMU_THP_FAULT_WP:
+ return HMM_MPROT_NONE;
+ case MMU_POISON:
+ case MMU_MREMAP:
+ case MMU_MUNMAP:
+ return HMM_MUNMAP;
+ case MMU_SOFT_DIRTY:
+ case MMU_MUNLOCK:
+ default:
+ return HMM_NONE;
+ }
+}
+
+static void hmm_event_unqueue_and_release_locked(struct hmm *hmm,
+ struct hmm_event *event)
+{
+ list_del_init(&event->list);
+ event->etype = HMM_NONE;
+ hmm->nevents--;
+}
+
+static void hmm_event_unqueue_and_release(struct hmm *hmm,
+ struct hmm_event *event)
+{
+ spin_lock(&hmm->lock);
+ list_del_init(&event->list);
+ event->etype = HMM_NONE;
+ hmm->nevents--;
+ spin_unlock(&hmm->lock);
+}
+
+static void hmm_event_unqueue(struct hmm *hmm,
+ struct hmm_event *event)
+{
+ spin_lock(&hmm->lock);
+ list_del_init(&event->list);
+ spin_unlock(&hmm->lock);
+}
+
+static void hmm_event_wait_queue(struct hmm *hmm,
+ struct hmm_event *event)
+{
+ struct hmm_event *wait;
+
+again:
+ wait = event;
+ list_for_each_entry_continue_reverse (wait, &hmm->pending, list) {
+ enum hmm_etype wait_type;
+
+ if (!hmm_event_overlap(event, wait)) {
+ continue;
+ }
+ wait_type = wait->etype;
+ spin_unlock(&hmm->lock);
+ wait_event(hmm->wait_queue, wait->etype != wait_type);
+ spin_lock(&hmm->lock);
+ goto again;
+ }
+}
+
+static void hmm_event_queue(struct hmm *hmm, struct hmm_event *event)
+{
+ spin_lock(&hmm->lock);
+ list_add_tail(&event->list, &hmm->pending);
+ hmm_event_wait_queue(hmm, event);
+ spin_unlock(&hmm->lock);
+}
+
+static void hmm_destroy_kref(struct kref *kref)
+{
+ struct hmm *hmm;
+ struct mm_struct *mm;
+
+ hmm = container_of(kref, struct hmm, kref);
+ mm = hmm->mm;
+ mm->hmm = NULL;
+ mmu_notifier_unregister(&hmm->mmu_notifier, mm);
+
+ if (!list_empty(&hmm->mirrors)) {
+ BUG();
+ printk(KERN_ERR "destroying an hmm with still active mirror\n"
+ "Leaking memory instead to avoid something worst.\n");
+ return;
+ }
+ kfree(hmm);
+}
+
+static inline struct hmm *hmm_ref(struct hmm *hmm)
+{
+ if (hmm) {
+ kref_get(&hmm->kref);
+ return hmm;
+ }
+ return NULL;
+}
+
+static inline struct hmm *hmm_unref(struct hmm *hmm)
+{
+ if (hmm) {
+ kref_put(&hmm->kref, hmm_destroy_kref);
+ }
+ return NULL;
+}
+
+static struct hmm_event *hmm_event_get(struct hmm *hmm,
+ unsigned long faddr,
+ unsigned long laddr,
+ enum hmm_etype etype)
+{
+ struct hmm_event *event;
+ unsigned id;
+
+ do {
+ spin_lock(&hmm->lock);
+ for (id = 0; id < HMM_MAX_EVENTS; ++id) {
+ if (hmm->events[id].etype == HMM_NONE) {
+ event = &hmm->events[id];
+ goto out;
+ }
+ }
+ spin_unlock(&hmm->lock);
+ wait_event(hmm->wait_queue, hmm->nevents < HMM_MAX_EVENTS);
+ } while (1);
+
+out:
+ event->etype = etype;
+ event->faddr = faddr;
+ event->laddr = laddr;
+ event->backoff = false;
+ INIT_LIST_HEAD(&event->fences);
+ hmm->nevents++;
+ list_add_tail(&event->list, &hmm->pending);
+ hmm_event_wait_queue(hmm, event);
+ spin_unlock(&hmm->lock);
+
+ return event;
+}
+
+static void hmm_update_mirrors(struct hmm *hmm,
+ struct vm_area_struct *vma,
+ struct hmm_event *event)
+{
+ struct hmm_mirror *mirror;
+ struct hmm_fence *fence = NULL, *tmp;
+ int ticket;
+
+retry:
+ ticket = srcu_read_lock(&srcu);
+ /* Because of retry we might already have scheduled some mirror
+ * skip those.
+ */
+ mirror = list_first_entry(&hmm->mirrors,
+ struct hmm_mirror,
+ mlist);
+ mirror = fence ? fence->mirror : mirror;
+ list_for_each_entry_continue (mirror, &hmm->mirrors, mlist) {
+ struct hmm_device *device = mirror->device;
+
+ fence = device->ops->update(mirror, vma, event->faddr,
+ event->laddr, event->etype);
+ if (fence) {
+ if (IS_ERR(fence)) {
+ srcu_read_unlock(&srcu, ticket);
+ hmm_mirror_cleanup(mirror);
+ goto retry;
+ }
+ kref_init(&fence->kref);
+ fence->mirror = mirror;
+ list_add_tail(&fence->list, &event->fences);
+ }
+ }
+ srcu_read_unlock(&srcu, ticket);
+
+ if (!fence) {
+ /* Nothing to wait for. */
+ return;
+ }
+
+ io_schedule();
+ list_for_each_entry_safe (fence, tmp, &event->fences, list) {
+ struct hmm_device *device;
+ int r;
+
+ mirror = fence->mirror;
+ device = mirror->device;
+
+ r = hmm_device_fence_wait(device, fence);
+ if (r) {
+ hmm_mirror_cleanup(mirror);
+ }
+ }
+}
+
+
+
+
+/* hmm_notifier - mmu_notifier hmm funcs tracking change to process mm.
+ *
+ * Callbacks for mmu notifier. We use use mmu notifier to track change made to
+ * process address space.
+ *
+ * Note that none of this callback needs to take a reference, as we sure that
+ * mm won't be destroy thus hmm won't be destroy either and it's fine if some
+ * hmm_mirror/hmm_device are destroy during those callbacks because this is
+ * serialize through either the hmm lock or the device lock.
+ */
+
+static void hmm_notifier_release(struct mmu_notifier *mn, struct mm_struct *mm)
+{
+ struct hmm *hmm;
+
+ if (!(hmm = hmm_ref(mm->hmm)) || hmm->dead) {
+ /* Already clean. */
+ hmm_unref(hmm);
+ return;
+ }
+
+ hmm->dead = true;
+
+ /*
+ * hmm->lock allow synchronization with hmm_mirror_unregister() an
+ * hmm_mirror can be removed only once.
+ */
+ spin_lock(&hmm->lock);
+ while (unlikely(!list_empty(&hmm->mirrors))) {
+ struct hmm_mirror *mirror;
+ struct hmm_device *device;
+
+ mirror = list_first_entry(&hmm->mirrors,
+ struct hmm_mirror,
+ mlist);
+ device = mirror->device;
+ if (!mirror->dead) {
+ /* Update mirror as being dead and remove it from the
+ * mirror list before freeing up any of its resources.
+ */
+ mirror->dead = true;
+ list_del_init(&mirror->mlist);
+ spin_unlock(&hmm->lock);
+
+ synchronize_srcu(&srcu);
+
+ device->ops->mirror_release(mirror);
+ hmm_mirror_cleanup(mirror);
+ spin_lock(&hmm->lock);
+ }
+ }
+ spin_unlock(&hmm->lock);
+ hmm_unref(hmm);
+}
+
+static void hmm_notifier_invalidate_range_start(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long faddr,
+ unsigned long laddr,
+ enum mmu_action action)
+{
+ struct hmm_event *event;
+ enum hmm_etype etype;
+ struct hmm *hmm;
+
+ if (!(hmm = hmm_ref(mm->hmm))) {
+ return;
+ }
+
+ etype = hmm_event_mmu(action);
+ switch (etype) {
+ case HMM_NONE:
+ hmm_unref(hmm);
+ return;
+ default:
+ break;
+ }
+
+ faddr = faddr & PAGE_MASK;
+ laddr = PAGE_ALIGN(laddr);
+
+ event = hmm_event_get(hmm, faddr, laddr, etype);
+ hmm_update_mirrors(hmm, vma, event);
+ /* Do not drop hmm reference here but in the range_end instead. */
+}
+
+static void hmm_notifier_invalidate_range_end(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long faddr,
+ unsigned long laddr,
+ enum mmu_action action)
+{
+ struct hmm_event *event = NULL;
+ enum hmm_etype etype;
+ struct hmm *hmm;
+ int i;
+
+ if (!(hmm = mm->hmm)) {
+ return;
+ }
+
+ etype = hmm_event_mmu(action);
+ switch (etype) {
+ case HMM_NONE:
+ return;
+ default:
+ break;
+ }
+
+ faddr = faddr & PAGE_MASK;
+ laddr = PAGE_ALIGN(laddr);
+
+ spin_lock(&hmm->lock);
+ for (i = 0; i < HMM_MAX_EVENTS; ++i, event = NULL) {
+ event = &hmm->events[i];
+ if (event->etype == etype &&
+ event->faddr == faddr &&
+ event->laddr == laddr &&
+ !list_empty(&event->list)) {
+ hmm_event_unqueue_and_release_locked(hmm, event);
+ break;
+ }
+ }
+ spin_unlock(&hmm->lock);
+
+ /* Drop reference from invalidate_range_start. */
+ hmm_unref(hmm);
+}
+
+static void hmm_notifier_invalidate_page(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ struct vm_area_struct *vma,
+ unsigned long faddr,
+ enum mmu_action action)
+{
+ unsigned long laddr;
+ struct hmm_event *event;
+ enum hmm_etype etype;
+ struct hmm *hmm;
+
+ if (!(hmm = hmm_ref(mm->hmm))) {
+ return;
+ }
+
+ etype = hmm_event_mmu(action);
+ switch (etype) {
+ case HMM_NONE:
+ return;
+ default:
+ break;
+ }
+
+ faddr = faddr & PAGE_MASK;
+ laddr = faddr + PAGE_SIZE;
+
+ event = hmm_event_get(hmm, faddr, laddr, etype);
+ hmm_update_mirrors(hmm, vma, event);
+ hmm_event_unqueue_and_release(hmm, event);
+ hmm_unref(hmm);
+}
+
+static struct mmu_notifier_ops hmm_notifier_ops = {
+ .release = hmm_notifier_release,
+ /* .clear_flush_young FIXME we probably want to do something. */
+ /* .test_young FIXME we probably want to do something. */
+ /* WARNING .change_pte must always bracketed by range_start/end there
+ * was patches to remove that behavior we must make sure that those
+ * patches are not included as alternative solution to issue they are
+ * trying to solve can be use.
+ *
+ * While hmm can not use the change_pte callback as non sleeping lock
+ * are held during change_pte callback.
+ */
+ .change_pte = NULL,
+ .invalidate_page = hmm_notifier_invalidate_page,
+ .invalidate_range_start = hmm_notifier_invalidate_range_start,
+ .invalidate_range_end = hmm_notifier_invalidate_range_end,
+};
+
+
+
+
+/* hmm_mirror - per device mirroring functions.
+ *
+ * Each device that mirror a process has a uniq hmm_mirror struct. A process
+ * can be mirror by several devices at the same time.
+ *
+ * Below are all the functions and there helpers use by device driver to mirror
+ * the process address space. Those functions either deals with updating the
+ * device page table (through hmm callback). Or provide helper functions use by
+ * the device driver to fault in range of memory in the device page table.
+ */
+
+static void hmm_mirror_cleanup(struct hmm_mirror *mirror)
+{
+ struct vm_area_struct *vma;
+ struct hmm_device *device = mirror->device;
+ struct hmm_event event;
+ struct hmm *hmm = mirror->hmm;
+
+ spin_lock(&hmm->lock);
+ if (mirror->dead) {
+ spin_unlock(&hmm->lock);
+ return;
+ }
+ mirror->dead = true;
+ list_del(&mirror->mlist);
+ spin_unlock(&hmm->lock);
+ synchronize_srcu(&srcu);
+ INIT_LIST_HEAD(&mirror->mlist);
+
+ event.etype = HMM_UNREGISTER;
+ event.faddr = 0UL;
+ event.laddr = -1L;
+ vma = find_vma_intersection(hmm->mm, event.faddr, event.laddr);
+ for (; vma; vma = vma->vm_next) {
+ struct hmm_fence *fence;
+
+ fence = device->ops->update(mirror, vma, vma->vm_start,
+ vma->vm_end, event.etype);
+ if (fence && !IS_ERR(fence)) {
+ kref_init(&fence->kref);
+ fence->mirror = mirror;
+ INIT_LIST_HEAD(&fence->list);
+ hmm_device_fence_wait(device, fence);
+ }
+ }
+
+ mutex_lock(&device->mutex);
+ list_del_init(&mirror->dlist);
+ mutex_unlock(&device->mutex);
+
+ mirror->hmm = hmm_unref(hmm);
+ hmm_mirror_unref(mirror);
+}
+
+static void hmm_mirror_destroy(struct kref *kref)
+{
+ struct hmm_mirror *mirror;
+ struct hmm_device *device;
+
+ mirror = container_of(kref, struct hmm_mirror, kref);
+ device = mirror->device;
+
+ BUG_ON(!list_empty(&mirror->mlist));
+ BUG_ON(!list_empty(&mirror->dlist));
+
+ device->ops->mirror_destroy(mirror);
+ hmm_device_unref(device);
+}
+
+struct hmm_mirror *hmm_mirror_ref(struct hmm_mirror *mirror)
+{
+ if (mirror) {
+ kref_get(&mirror->kref);
+ return mirror;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(hmm_mirror_ref);
+
+struct hmm_mirror *hmm_mirror_unref(struct hmm_mirror *mirror)
+{
+ if (mirror) {
+ kref_put(&mirror->kref, hmm_mirror_destroy);
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(hmm_mirror_unref);
+
+int hmm_mirror_register(struct hmm_mirror *mirror,
+ struct hmm_device *device,
+ struct mm_struct *mm)
+{
+ struct hmm *hmm = NULL;
+ int ret = 0;
+
+ /* Sanity checks. */
+ BUG_ON(!mirror);
+ BUG_ON(!device);
+ BUG_ON(!mm);
+
+ /* Take reference on device only on success. */
+ kref_init(&mirror->kref);
+ mirror->device = device;
+ mirror->dead = false;
+ INIT_LIST_HEAD(&mirror->mlist);
+ INIT_LIST_HEAD(&mirror->dlist);
+
+ down_write(&mm->mmap_sem);
+ if (mm->hmm == NULL) {
+ /* no hmm registered yet so register one */
+ hmm = kzalloc(sizeof(*mm->hmm), GFP_KERNEL);
+ if (hmm == NULL) {
+ ret = -ENOMEM;
+ goto out_cleanup;
+ }
+
+ ret = hmm_init(hmm, mm);
+ if (ret) {
+ kfree(hmm);
+ hmm = NULL;
+ goto out_cleanup;
+ }
+
+ /* now set hmm, make sure no mmu notifer callback might be call */
+ ret = mm_take_all_locks(mm);
+ if (unlikely(ret)) {
+ goto out_cleanup;
+ }
+ mm->hmm = hmm;
+ mirror->hmm = hmm;
+ hmm = NULL;
+ } else {
+ struct hmm_mirror *tmp;
+ int id;
+
+ id = srcu_read_lock(&srcu);
+ list_for_each_entry(tmp, &mm->hmm->mirrors, mlist) {
+ if (tmp->device == mirror->device) {
+ /* A process can be mirrored only once by same
+ * device.
+ */
+ srcu_read_unlock(&srcu, id);
+ ret = -EINVAL;
+ goto out_cleanup;
+ }
+ }
+ srcu_read_unlock(&srcu, id);
+
+ ret = mm_take_all_locks(mm);
+ if (unlikely(ret)) {
+ goto out_cleanup;
+ }
+ mirror->hmm = hmm_ref(mm->hmm);
+ }
+
+ /*
+ * A side note: hmm_notifier_release() can't run concurrently with
+ * us because we hold the mm_users pin (either implicitly as
+ * current->mm or explicitly with get_task_mm() or similar).
+ *
+ * We can't race against any other mmu notifier method either
+ * thanks to mm_take_all_locks().
+ */
+ spin_lock(&mm->hmm->lock);
+ list_add_rcu(&mirror->mlist, &mm->hmm->mirrors);
+ spin_unlock(&mm->hmm->lock);
+ mm_drop_all_locks(mm);
+
+out_cleanup:
+ if (hmm) {
+ mmu_notifier_unregister(&hmm->mmu_notifier, mm);
+ kfree(hmm);
+ }
+ up_write(&mm->mmap_sem);
+
+ if (!ret) {
+ struct hmm_device *device = mirror->device;
+
+ hmm_device_ref(device);
+ mutex_lock(&device->mutex);
+ list_add(&mirror->dlist, &device->mirrors);
+ mutex_unlock(&device->mutex);
+ }
+ return ret;
+}
+EXPORT_SYMBOL(hmm_mirror_register);
+
+void hmm_mirror_unregister(struct hmm_mirror *mirror)
+{
+ struct hmm *hmm;
+
+ if (!mirror) {
+ return;
+ }
+ hmm = hmm_ref(mirror->hmm);
+ if (!hmm) {
+ return;
+ }
+
+ down_read(&hmm->mm->mmap_sem);
+ hmm_mirror_cleanup(mirror);
+ up_read(&hmm->mm->mmap_sem);
+ hmm_unref(hmm);
+}
+EXPORT_SYMBOL(hmm_mirror_unregister);
+
+struct hmm_mirror_fault {
+ struct hmm_mirror *mirror;
+ struct hmm_event *event;
+ struct vm_area_struct *vma;
+ struct mmu_gather tlb;
+ int flush;
+};
+
+static int hmm_mirror_fault_pmd(pmd_t *pmdp,
+ unsigned long faddr,
+ unsigned long laddr,
+ struct mm_walk *walk)
+{
+ struct hmm_mirror_fault *mirror_fault = walk->private;
+ struct hmm_mirror *mirror = mirror_fault->mirror;
+ struct hmm_device *device = mirror->device;
+ struct hmm_event *event = mirror_fault->event;
+ pte_t *ptep;
+ int ret;
+
+ event->iaddr = faddr;
+
+ if (pmd_none(*pmdp)) {
+ return -ENOENT;
+ }
+
+ if (pmd_trans_huge(*pmdp)) {
+ /* FIXME */
+ return -EINVAL;
+ }
+
+ if (pmd_none_or_trans_huge_or_clear_bad(pmdp)) {
+ return -EFAULT;
+ }
+
+ ptep = pte_offset_map(pmdp, faddr);
+ ret = device->ops->fault(mirror, faddr, laddr, ptep, event);
+ pte_unmap(ptep);
+ return ret;
+}
+
+static int hmm_fault_mm(struct hmm *hmm,
+ struct vm_area_struct *vma,
+ unsigned long faddr,
+ unsigned long laddr,
+ bool write)
+{
+ int r;
+
+ if (laddr <= faddr) {
+ return -EINVAL;
+ }
+
+ for (; faddr < laddr; faddr += PAGE_SIZE) {
+ unsigned flags = 0;
+
+ flags |= write ? FAULT_FLAG_WRITE : 0;
+ flags |= FAULT_FLAG_ALLOW_RETRY;
+ do {
+ r = handle_mm_fault(hmm->mm, vma, faddr, flags);
+ if (!(r & VM_FAULT_RETRY) && (r & VM_FAULT_ERROR)) {
+ if (r & VM_FAULT_OOM) {
+ return -ENOMEM;
+ }
+ /* Same error code for all other cases. */
+ return -EFAULT;
+ }
+ flags &= ~FAULT_FLAG_ALLOW_RETRY;
+ } while (r & VM_FAULT_RETRY);
+ }
+
+ return 0;
+}
+
+/* see include/linux/hmm.h */
+int hmm_mirror_fault(struct hmm_mirror *mirror,
+ struct hmm_event *event)
+{
+ struct vm_area_struct *vma;
+ struct hmm_mirror_fault mirror_fault;
+ struct hmm_device *device;
+ struct mm_walk walk = {0};
+ unsigned long npages;
+ struct hmm *hmm;
+ int ret = 0;
+
+ if (!mirror || !event || event->faddr >= event->laddr) {
+ return -EINVAL;
+ }
+ if (mirror->dead) {
+ return -ENODEV;
+ }
+ device = mirror->device;
+ hmm = mirror->hmm;
+
+ event->faddr = event->faddr & PAGE_MASK;
+ event->laddr = PAGE_ALIGN(event->laddr);
+ event->iaddr = event->faddr;
+ npages = (event->laddr - event->faddr) >> PAGE_SHIFT;
+
+retry:
+ down_read(&hmm->mm->mmap_sem);
+ hmm_event_queue(hmm, event);
+
+ vma = find_extend_vma(hmm->mm, event->faddr);
+ if (!vma) {
+ if (event->iaddr > event->faddr) {
+ /* Fault succeed up to iaddr. */
+ event->laddr = event->iaddr;
+ goto out;
+ }
+ /* Allow device driver to learn about first valid address in
+ * the range it was trying to fault in so it can restart the
+ * fault at this address.
+ */
+ vma = find_vma_intersection(hmm->mm,event->faddr,event->laddr);
+ if (vma) {
+ event->laddr = vma->vm_start;
+ }
+ ret = -EFAULT;
+ goto out;
+ }
+
+ if ((vma->vm_flags & (VM_IO | VM_PFNMAP | VM_MIXEDMAP | VM_HUGETLB))) {
+ event->laddr = min(event->laddr, vma->vm_end);
+ ret = -EFAULT;
+ goto out;
+ }
+
+ event->laddr = min(event->laddr, vma->vm_end);
+ mirror_fault.vma = vma;
+ mirror_fault.flush = 0;
+ mirror_fault.event = event;
+ mirror_fault.mirror = mirror;
+ walk.mm = hmm->mm;
+ walk.private = &mirror_fault;
+
+ switch (event->etype) {
+ case HMM_RFAULT:
+ case HMM_WFAULT:
+ walk.pmd_entry = hmm_mirror_fault_pmd;
+ ret = walk_page_range(event->faddr, event->laddr, &walk);
+ break;
+ default:
+ ret = -EINVAL;
+ break;
+ }
+
+out:
+ hmm_event_unqueue(hmm, event);
+ if (!event->backoff && (ret == -ENOENT || ret == -EACCES)) {
+ bool write = (event->etype == HMM_WFAULT);
+
+ ret = hmm_fault_mm(hmm, vma, event->iaddr, event->laddr, write);
+ if (!ret) {
+ ret = -EAGAIN;
+ }
+ }
+ up_read(&hmm->mm->mmap_sem);
+ wake_up(&device->wait_queue);
+ wake_up(&hmm->wait_queue);
+ if (mirror->dead || hmm->dead) {
+ return -ENODEV;
+ }
+ if (event->backoff || ret == -EAGAIN) {
+ event->backoff = false;
+ goto retry;
+ }
+ return ret;
+}
+EXPORT_SYMBOL(hmm_mirror_fault);
+
+
+
+
+/* hmm_device - Each device driver must register one and only one hmm_device
+ *
+ * The hmm_device is the link btw hmm and each device driver.
+ */
+
+static void hmm_device_destroy(struct kref *kref)
+{
+ struct hmm_device *device;
+
+ device = container_of(kref, struct hmm_device, kref);
+ BUG_ON(!list_empty(&device->mirrors));
+
+ device->ops->device_destroy(device);
+}
+
+struct hmm_device *hmm_device_ref(struct hmm_device *device)
+{
+ if (device) {
+ kref_get(&device->kref);
+ return device;
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(hmm_device_ref);
+
+struct hmm_device *hmm_device_unref(struct hmm_device *device)
+{
+ if (device) {
+ kref_put(&device->kref, hmm_device_destroy);
+ }
+ return NULL;
+}
+EXPORT_SYMBOL(hmm_device_unref);
+
+/* see include/linux/hmm.h */
+int hmm_device_register(struct hmm_device *device,
+ const char *name)
+{
+ /* sanity check */
+ BUG_ON(!device);
+ BUG_ON(!device->ops);
+ BUG_ON(!device->ops->device_destroy);
+ BUG_ON(!device->ops->mirror_release);
+ BUG_ON(!device->ops->mirror_destroy);
+ BUG_ON(!device->ops->fence_wait);
+ BUG_ON(!device->ops->fence_destroy);
+ BUG_ON(!device->ops->update);
+ BUG_ON(!device->ops->fault);
+
+ kref_init(&device->kref);
+ device->name = name;
+ mutex_init(&device->mutex);
+ INIT_LIST_HEAD(&device->mirrors);
+ init_waitqueue_head(&device->wait_queue);
+
+ return 0;
+}
+EXPORT_SYMBOL(hmm_device_register);
+
+static int hmm_device_fence_wait(struct hmm_device *device,
+ struct hmm_fence *fence)
+{
+ int ret;
+
+ if (fence == NULL) {
+ return 0;
+ }
+
+ list_del_init(&fence->list);
+ do {
+ io_schedule();
+ ret = device->ops->fence_wait(fence);
+ } while (ret == -EAGAIN);
+
+ hmm_fence_unref(fence);
+
+ return ret;
+}
+
+
+
+
+/* This is called after the last hmm_notifier_release() returned */
+void __hmm_destroy(struct mm_struct *mm)
+{
+ kref_put(&mm->hmm->kref, hmm_destroy_kref);
+}
+
+static int __init hmm_module_init(void)
+{
+ int ret;
+
+ ret = init_srcu_struct(&srcu);
+ if (ret) {
+ return ret;
+ }
+ return 0;
+}
+module_init(hmm_module_init);
+
+static void __exit hmm_module_exit(void)
+{
+ cleanup_srcu_struct(&srcu);
+}
+module_exit(hmm_module_exit);
--
1.9.0
^ permalink raw reply [flat|nested] 5+ messages in thread* [PATCH 5/5] hmm/dummy: dummy driver to showcase the hmm api.
2014-06-12 18:57 ` [PATCH 1/5] mm: differentiate unmap for vmscan from other unmap j.glisse
` (2 preceding siblings ...)
2014-06-12 18:57 ` [PATCH 4/5] hmm: heterogeneous memory management v2 j.glisse
@ 2014-06-12 18:57 ` j.glisse
3 siblings, 0 replies; 5+ messages in thread
From: j.glisse @ 2014-06-12 18:57 UTC (permalink / raw)
To: akpm, linux-kernel, linux-mm; +Cc: Jérôme Glisse
From: Jérôme Glisse <jglisse@redhat.com>
This is a dummy driver which full fill two purposes :
- showcase the hmm api and gives references on how to use it.
- provide an extensive user space api to stress test hmm.
This is a particularly dangerous module as it allow to access a
mirror of a process address space through its device file. Hence
it should not be enabled by default and only people actively
developing for hmm should use it.
Signed-off-by: Jérôme Glisse <jglisse@redhat.com>
---
drivers/char/Kconfig | 9 +
drivers/char/Makefile | 1 +
drivers/char/hmm_dummy.c | 1136 ++++++++++++++++++++++++++++++++++++++++
include/uapi/linux/hmm_dummy.h | 34 ++
4 files changed, 1180 insertions(+)
create mode 100644 drivers/char/hmm_dummy.c
create mode 100644 include/uapi/linux/hmm_dummy.h
diff --git a/drivers/char/Kconfig b/drivers/char/Kconfig
index 6e9f74a..199e111 100644
--- a/drivers/char/Kconfig
+++ b/drivers/char/Kconfig
@@ -600,5 +600,14 @@ config TILE_SROM
device appear much like a simple EEPROM, and knows
how to partition a single ROM for multiple purposes.
+config HMM_DUMMY
+ tristate "hmm dummy driver to test hmm."
+ depends on HMM
+ default n
+ help
+ Say Y here if you want to build the hmm dummy driver that allow you
+ to test the hmm infrastructure by mapping a process address space
+ in hmm dummy driver device file. When in doubt, say "N".
+
endmenu
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index a324f93..83d89b8 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -61,3 +61,4 @@ obj-$(CONFIG_JS_RTC) += js-rtc.o
js-rtc-y = rtc.o
obj-$(CONFIG_TILE_SROM) += tile-srom.o
+obj-$(CONFIG_HMM_DUMMY) += hmm_dummy.o
diff --git a/drivers/char/hmm_dummy.c b/drivers/char/hmm_dummy.c
new file mode 100644
index 0000000..7acb642
--- /dev/null
+++ b/drivers/char/hmm_dummy.c
@@ -0,0 +1,1136 @@
+/*
+ * Copyright 2013 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Authors: Jérôme Glisse <jglisse@redhat.com>
+ */
+/* This is a dummy driver made to exercice the HMM (hardware memory management)
+ * API of the kernel. It allow an userspace program to map its whole address
+ * space through the hmm dummy driver file.
+ *
+ * In here mirror address are address in the process address space that is
+ * being mirrored. While virtual address are the address in the current
+ * process that has the hmm dummy dev file mapped (address of the file
+ * mapping).
+ *
+ * You must be carefull to not mix one and another.
+ */
+#include <linux/init.h>
+#include <linux/fs.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/major.h>
+#include <linux/cdev.h>
+#include <linux/device.h>
+#include <linux/mutex.h>
+#include <linux/rwsem.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/delay.h>
+#include <linux/hmm.h>
+
+#include <uapi/linux/hmm_dummy.h>
+
+#define HMM_DUMMY_DEVICE_NAME "hmm_dummy_device"
+#define HMM_DUMMY_DEVICE_MAX_MIRRORS 4
+
+struct hmm_dummy_device;
+
+struct hmm_dummy_mirror {
+ struct file *filp;
+ struct hmm_dummy_device *ddevice;
+ struct hmm_mirror mirror;
+ unsigned minor;
+ pid_t pid;
+ struct mm_struct *mm;
+ unsigned long *pgdp;
+ struct mutex mutex;
+ bool stop;
+};
+
+struct hmm_dummy_device {
+ struct cdev cdev;
+ struct hmm_device device;
+ dev_t dev;
+ int major;
+ struct mutex mutex;
+ char name[32];
+ /* device file mapping tracking (keep track of all vma) */
+ struct hmm_dummy_mirror *dmirrors[HMM_DUMMY_DEVICE_MAX_MIRRORS];
+ struct address_space *fmapping[HMM_DUMMY_DEVICE_MAX_MIRRORS];
+};
+
+/* We only create 2 device to show the inter device rmem sharing/migration
+ * capabilities.
+ */
+static struct hmm_dummy_device ddevices[2];
+
+static void hmm_dummy_device_print(struct hmm_dummy_device *device,
+ unsigned minor,
+ const char *format,
+ ...)
+{
+ va_list args;
+
+ printk(KERN_INFO "[%s:%d] ", device->name, minor);
+ va_start(args, format);
+ vprintk(format, args);
+ va_end(args);
+}
+
+
+/* hmm_dummy_pt - dummy page table, the dummy device fake its own page table.
+ *
+ * Helper function to manage the dummy device page table.
+ */
+#define HMM_DUMMY_PTE_VALID (1UL << 0UL)
+#define HMM_DUMMY_PTE_READ (1UL << 1UL)
+#define HMM_DUMMY_PTE_WRITE (1UL << 2UL)
+#define HMM_DUMMY_PTE_DIRTY (1UL << 3UL)
+#define HMM_DUMMY_PFN_SHIFT (PAGE_SHIFT)
+
+#define ARCH_PAGE_SIZE ((unsigned long)PAGE_SIZE)
+#define ARCH_PAGE_SHIFT ((unsigned long)PAGE_SHIFT)
+
+#define HMM_DUMMY_PTRS_PER_LEVEL (ARCH_PAGE_SIZE / sizeof(long))
+#ifdef CONFIG_64BIT
+#define HMM_DUMMY_BITS_PER_LEVEL (ARCH_PAGE_SHIFT - 3UL)
+#else
+#define HMM_DUMMY_BITS_PER_LEVEL (ARCH_PAGE_SHIFT - 2UL)
+#endif
+#define HMM_DUMMY_PLD_SHIFT (ARCH_PAGE_SHIFT)
+#define HMM_DUMMY_PMD_SHIFT (HMM_DUMMY_PLD_SHIFT + HMM_DUMMY_BITS_PER_LEVEL)
+#define HMM_DUMMY_PUD_SHIFT (HMM_DUMMY_PMD_SHIFT + HMM_DUMMY_BITS_PER_LEVEL)
+#define HMM_DUMMY_PGD_SHIFT (HMM_DUMMY_PUD_SHIFT + HMM_DUMMY_BITS_PER_LEVEL)
+#define HMM_DUMMY_PGD_NPTRS (1UL << HMM_DUMMY_BITS_PER_LEVEL)
+#define HMM_DUMMY_PMD_NPTRS (1UL << HMM_DUMMY_BITS_PER_LEVEL)
+#define HMM_DUMMY_PUD_NPTRS (1UL << HMM_DUMMY_BITS_PER_LEVEL)
+#define HMM_DUMMY_PLD_NPTRS (1UL << HMM_DUMMY_BITS_PER_LEVEL)
+#define HMM_DUMMY_PLD_SIZE (1UL << (HMM_DUMMY_PLD_SHIFT + HMM_DUMMY_BITS_PER_LEVEL))
+#define HMM_DUMMY_PMD_SIZE (1UL << (HMM_DUMMY_PMD_SHIFT + HMM_DUMMY_BITS_PER_LEVEL))
+#define HMM_DUMMY_PUD_SIZE (1UL << (HMM_DUMMY_PUD_SHIFT + HMM_DUMMY_BITS_PER_LEVEL))
+#define HMM_DUMMY_PGD_SIZE (1UL << (HMM_DUMMY_PGD_SHIFT + HMM_DUMMY_BITS_PER_LEVEL))
+#define HMM_DUMMY_PLD_MASK (~(HMM_DUMMY_PLD_SIZE - 1UL))
+#define HMM_DUMMY_PMD_MASK (~(HMM_DUMMY_PMD_SIZE - 1UL))
+#define HMM_DUMMY_PUD_MASK (~(HMM_DUMMY_PUD_SIZE - 1UL))
+#define HMM_DUMMY_PGD_MASK (~(HMM_DUMMY_PGD_SIZE - 1UL))
+#define HMM_DUMMY_MAX_ADDR (1UL << (HMM_DUMMY_PGD_SHIFT + HMM_DUMMY_BITS_PER_LEVEL))
+
+static inline unsigned long hmm_dummy_pld_index(unsigned long addr)
+{
+ return (addr >> HMM_DUMMY_PLD_SHIFT) & (HMM_DUMMY_PLD_NPTRS - 1UL);
+}
+
+static inline unsigned long hmm_dummy_pmd_index(unsigned long addr)
+{
+ return (addr >> HMM_DUMMY_PMD_SHIFT) & (HMM_DUMMY_PMD_NPTRS - 1UL);
+}
+
+static inline unsigned long hmm_dummy_pud_index(unsigned long addr)
+{
+ return (addr >> HMM_DUMMY_PUD_SHIFT) & (HMM_DUMMY_PUD_NPTRS - 1UL);
+}
+
+static inline unsigned long hmm_dummy_pgd_index(unsigned long addr)
+{
+ return (addr >> HMM_DUMMY_PGD_SHIFT) & (HMM_DUMMY_PGD_NPTRS - 1UL);
+}
+
+static inline unsigned long hmm_dummy_pld_base(unsigned long addr)
+{
+ return (addr & HMM_DUMMY_PLD_MASK);
+}
+
+static inline unsigned long hmm_dummy_pmd_base(unsigned long addr)
+{
+ return (addr & HMM_DUMMY_PMD_MASK);
+}
+
+static inline unsigned long hmm_dummy_pud_base(unsigned long addr)
+{
+ return (addr & HMM_DUMMY_PUD_MASK);
+}
+
+static inline unsigned long hmm_dummy_pgd_base(unsigned long addr)
+{
+ return (addr & HMM_DUMMY_PGD_MASK);
+}
+
+static inline unsigned long hmm_dummy_pld_next(unsigned long addr)
+{
+ return (addr & HMM_DUMMY_PLD_MASK) + HMM_DUMMY_PLD_SIZE;
+}
+
+static inline unsigned long hmm_dummy_pmd_next(unsigned long addr)
+{
+ return (addr & HMM_DUMMY_PMD_MASK) + HMM_DUMMY_PMD_SIZE;
+}
+
+static inline unsigned long hmm_dummy_pud_next(unsigned long addr)
+{
+ return (addr & HMM_DUMMY_PUD_MASK) + HMM_DUMMY_PUD_SIZE;
+}
+
+static inline unsigned long hmm_dummy_pgd_next(unsigned long addr)
+{
+ return (addr & HMM_DUMMY_PGD_MASK) + HMM_DUMMY_PGD_SIZE;
+}
+
+static inline struct page *hmm_dummy_pte_to_page(unsigned long pte)
+{
+ if (!(pte & HMM_DUMMY_PTE_VALID)) {
+ return NULL;
+ }
+ return pfn_to_page((pte >> HMM_DUMMY_PFN_SHIFT));
+}
+
+struct hmm_dummy_pt_map {
+ struct hmm_dummy_mirror *dmirror;
+ struct page *pud_page;
+ struct page *pmd_page;
+ struct page *pld_page;
+ unsigned long pgd_idx;
+ unsigned long pud_idx;
+ unsigned long pmd_idx;
+ unsigned long *pudp;
+ unsigned long *pmdp;
+ unsigned long *pldp;
+};
+
+static inline unsigned long *hmm_dummy_pt_pud_map(struct hmm_dummy_pt_map *pt_map,
+ unsigned long addr)
+{
+ struct hmm_dummy_mirror *dmirror = pt_map->dmirror;
+ unsigned long *pdep;
+
+ if (!dmirror->pgdp) {
+ return NULL;
+ }
+
+ if (!pt_map->pud_page || pt_map->pgd_idx != hmm_dummy_pgd_index(addr)) {
+ if (pt_map->pud_page) {
+ kunmap(pt_map->pud_page);
+ pt_map->pud_page = NULL;
+ pt_map->pudp = NULL;
+ }
+ pt_map->pgd_idx = hmm_dummy_pgd_index(addr);
+ pdep = &dmirror->pgdp[pt_map->pgd_idx];
+ if (!((*pdep) & HMM_DUMMY_PTE_VALID)) {
+ return NULL;
+ }
+ pt_map->pud_page = pfn_to_page((*pdep) >> HMM_DUMMY_PFN_SHIFT);
+ pt_map->pudp = kmap(pt_map->pud_page);
+ }
+ return pt_map->pudp;
+}
+
+static inline unsigned long *hmm_dummy_pt_pmd_map(struct hmm_dummy_pt_map *pt_map,
+ unsigned long addr)
+{
+ unsigned long *pdep;
+
+ if (!hmm_dummy_pt_pud_map(pt_map, addr)) {
+ return NULL;
+ }
+
+ if (!pt_map->pmd_page || pt_map->pud_idx != hmm_dummy_pud_index(addr)) {
+ if (pt_map->pmd_page) {
+ kunmap(pt_map->pmd_page);
+ pt_map->pmd_page = NULL;
+ pt_map->pmdp = NULL;
+ }
+ pt_map->pud_idx = hmm_dummy_pud_index(addr);
+ pdep = &pt_map->pudp[pt_map->pud_idx];
+ if (!((*pdep) & HMM_DUMMY_PTE_VALID)) {
+ return NULL;
+ }
+ pt_map->pmd_page = pfn_to_page((*pdep) >> HMM_DUMMY_PFN_SHIFT);
+ pt_map->pmdp = kmap(pt_map->pmd_page);
+ }
+ return pt_map->pmdp;
+}
+
+static inline unsigned long *hmm_dummy_pt_pld_map(struct hmm_dummy_pt_map *pt_map,
+ unsigned long addr)
+{
+ unsigned long *pdep;
+
+ if (!hmm_dummy_pt_pmd_map(pt_map, addr)) {
+ return NULL;
+ }
+
+ if (!pt_map->pld_page || pt_map->pmd_idx != hmm_dummy_pmd_index(addr)) {
+ if (pt_map->pld_page) {
+ kunmap(pt_map->pld_page);
+ pt_map->pld_page = NULL;
+ pt_map->pldp = NULL;
+ }
+ pt_map->pmd_idx = hmm_dummy_pmd_index(addr);
+ pdep = &pt_map->pmdp[pt_map->pmd_idx];
+ if (!((*pdep) & HMM_DUMMY_PTE_VALID)) {
+ return NULL;
+ }
+ pt_map->pld_page = pfn_to_page((*pdep) >> HMM_DUMMY_PFN_SHIFT);
+ pt_map->pldp = kmap(pt_map->pld_page);
+ }
+ return pt_map->pldp;
+}
+
+static inline void hmm_dummy_pt_pld_unmap(struct hmm_dummy_pt_map *pt_map)
+{
+ if (pt_map->pld_page) {
+ kunmap(pt_map->pld_page);
+ pt_map->pld_page = NULL;
+ pt_map->pldp = NULL;
+ }
+}
+
+static inline void hmm_dummy_pt_pmd_unmap(struct hmm_dummy_pt_map *pt_map)
+{
+ hmm_dummy_pt_pld_unmap(pt_map);
+ if (pt_map->pmd_page) {
+ kunmap(pt_map->pmd_page);
+ pt_map->pmd_page = NULL;
+ pt_map->pmdp = NULL;
+ }
+}
+
+static inline void hmm_dummy_pt_pud_unmap(struct hmm_dummy_pt_map *pt_map)
+{
+ hmm_dummy_pt_pmd_unmap(pt_map);
+ if (pt_map->pud_page) {
+ kunmap(pt_map->pud_page);
+ pt_map->pud_page = NULL;
+ pt_map->pudp = NULL;
+ }
+}
+
+static inline void hmm_dummy_pt_unmap(struct hmm_dummy_pt_map *pt_map)
+{
+ hmm_dummy_pt_pud_unmap(pt_map);
+}
+
+static int hmm_dummy_pt_alloc(struct hmm_dummy_mirror *dmirror,
+ unsigned long faddr,
+ unsigned long laddr)
+{
+ unsigned long *pgdp, *pudp, *pmdp;
+
+ if (dmirror->stop) {
+ return -EINVAL;
+ }
+
+ if (dmirror->pgdp == NULL) {
+ dmirror->pgdp = kzalloc(PAGE_SIZE, GFP_KERNEL);
+ if (dmirror->pgdp == NULL) {
+ return -ENOMEM;
+ }
+ }
+
+ for (; faddr < laddr; faddr = hmm_dummy_pld_next(faddr)) {
+ struct page *pud_page, *pmd_page;
+
+ pgdp = &dmirror->pgdp[hmm_dummy_pgd_index(faddr)];
+ if (!((*pgdp) & HMM_DUMMY_PTE_VALID)) {
+ pud_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!pud_page) {
+ return -ENOMEM;
+ }
+ *pgdp = (page_to_pfn(pud_page)<<HMM_DUMMY_PFN_SHIFT);
+ *pgdp |= HMM_DUMMY_PTE_VALID;
+ }
+
+ pud_page = pfn_to_page((*pgdp) >> HMM_DUMMY_PFN_SHIFT);
+ pudp = kmap(pud_page);
+ pudp = &pudp[hmm_dummy_pud_index(faddr)];
+ if (!((*pudp) & HMM_DUMMY_PTE_VALID)) {
+ pmd_page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!pmd_page) {
+ kunmap(pud_page);
+ return -ENOMEM;
+ }
+ *pudp = (page_to_pfn(pmd_page)<<HMM_DUMMY_PFN_SHIFT);
+ *pudp |= HMM_DUMMY_PTE_VALID;
+ }
+
+ pmd_page = pfn_to_page((*pudp) >> HMM_DUMMY_PFN_SHIFT);
+ pmdp = kmap(pmd_page);
+ pmdp = &pmdp[hmm_dummy_pmd_index(faddr)];
+ if (!((*pmdp) & HMM_DUMMY_PTE_VALID)) {
+ struct page *page;
+
+ page = alloc_page(GFP_KERNEL | __GFP_ZERO);
+ if (!page) {
+ kunmap(pmd_page);
+ kunmap(pud_page);
+ return -ENOMEM;
+ }
+ *pmdp = (page_to_pfn(page) << HMM_DUMMY_PFN_SHIFT);
+ *pmdp |= HMM_DUMMY_PTE_VALID;
+ }
+
+ kunmap(pmd_page);
+ kunmap(pud_page);
+ }
+
+ return 0;
+}
+
+static void hmm_dummy_pt_free_pmd(struct hmm_dummy_pt_map *pt_map,
+ unsigned long faddr,
+ unsigned long laddr)
+{
+ for (; faddr < laddr; faddr = hmm_dummy_pld_next(faddr)) {
+ unsigned long pfn, *pmdp, next;
+ struct page *page;
+
+ next = min(hmm_dummy_pld_next(faddr), laddr);
+ if (faddr > hmm_dummy_pld_base(faddr) || laddr < next) {
+ continue;
+ }
+ pmdp = hmm_dummy_pt_pmd_map(pt_map, faddr);
+ if (!pmdp) {
+ continue;
+ }
+ if (!(pmdp[hmm_dummy_pmd_index(faddr)] & HMM_DUMMY_PTE_VALID)) {
+ continue;
+ }
+ pfn = pmdp[hmm_dummy_pmd_index(faddr)] >> HMM_DUMMY_PFN_SHIFT;
+ page = pfn_to_page(pfn);
+ pmdp[hmm_dummy_pmd_index(faddr)] = 0;
+ __free_page(page);
+ }
+}
+
+static void hmm_dummy_pt_free_pud(struct hmm_dummy_pt_map *pt_map,
+ unsigned long faddr,
+ unsigned long laddr)
+{
+ for (; faddr < laddr; faddr = hmm_dummy_pmd_next(faddr)) {
+ unsigned long pfn, *pudp, next;
+ struct page *page;
+
+ next = min(hmm_dummy_pmd_next(faddr), laddr);
+ hmm_dummy_pt_free_pmd(pt_map, faddr, next);
+ hmm_dummy_pt_pmd_unmap(pt_map);
+ if (faddr > hmm_dummy_pmd_base(faddr) || laddr < next) {
+ continue;
+ }
+ pudp = hmm_dummy_pt_pud_map(pt_map, faddr);
+ if (!pudp) {
+ continue;
+ }
+ if (!(pudp[hmm_dummy_pud_index(faddr)] & HMM_DUMMY_PTE_VALID)) {
+ continue;
+ }
+ pfn = pudp[hmm_dummy_pud_index(faddr)] >> HMM_DUMMY_PFN_SHIFT;
+ page = pfn_to_page(pfn);
+ pudp[hmm_dummy_pud_index(faddr)] = 0;
+ __free_page(page);
+ }
+}
+
+static void hmm_dummy_pt_free(struct hmm_dummy_mirror *dmirror,
+ unsigned long faddr,
+ unsigned long laddr)
+{
+ struct hmm_dummy_pt_map pt_map = {0};
+
+ if (!dmirror->pgdp || (laddr - faddr) < HMM_DUMMY_PLD_SIZE) {
+ return;
+ }
+
+ pt_map.dmirror = dmirror;
+
+ for (; faddr < laddr; faddr = hmm_dummy_pud_next(faddr)) {
+ unsigned long pfn, *pgdp, next;
+ struct page *page;
+
+ next = min(hmm_dummy_pud_next(faddr), laddr);
+ pgdp = dmirror->pgdp;
+ hmm_dummy_pt_free_pud(&pt_map, faddr, next);
+ hmm_dummy_pt_pud_unmap(&pt_map);
+ if (faddr > hmm_dummy_pud_base(faddr) || laddr < next) {
+ continue;
+ }
+ if (!(pgdp[hmm_dummy_pgd_index(faddr)] & HMM_DUMMY_PTE_VALID)) {
+ continue;
+ }
+ pfn = pgdp[hmm_dummy_pgd_index(faddr)] >> HMM_DUMMY_PFN_SHIFT;
+ page = pfn_to_page(pfn);
+ pgdp[hmm_dummy_pgd_index(faddr)] = 0;
+ __free_page(page);
+ }
+ hmm_dummy_pt_unmap(&pt_map);
+}
+
+
+
+
+/* hmm_ops - hmm callback for the hmm dummy driver.
+ *
+ * Below are the various callback that the hmm api require for a device. The
+ * implementation of the dummy device driver is necessarily simpler that what
+ * a real device driver would do. We do not have interrupt nor any kind of
+ * command buffer on to which schedule memory invalidation and updates.
+ */
+static void hmm_dummy_device_destroy(struct hmm_device *device)
+{
+ /* No-op for the dummy driver. */
+}
+
+static void hmm_dummy_mirror_release(struct hmm_mirror *mirror)
+{
+ struct hmm_dummy_mirror *dmirror;
+
+ dmirror = container_of(mirror, struct hmm_dummy_mirror, mirror);
+ dmirror->stop = true;
+ mutex_lock(&dmirror->mutex);
+ hmm_dummy_pt_free(dmirror, 0, HMM_DUMMY_MAX_ADDR);
+ if (dmirror->pgdp) {
+ kfree(dmirror->pgdp);
+ dmirror->pgdp = NULL;
+ }
+ mutex_unlock(&dmirror->mutex);
+}
+
+static void hmm_dummy_mirror_destroy(struct hmm_mirror *mirror)
+{
+ /* No-op for the dummy driver. */
+ // FIXME print that the pid is no longer mirror
+}
+
+static int hmm_dummy_fence_wait(struct hmm_fence *fence)
+{
+ /* FIXME use some kind of fake event and delay dirty and dummy page
+ * clearing to this function.
+ */
+ return 0;
+}
+
+static void hmm_dummy_fence_destroy(struct hmm_fence *fence)
+{
+ /* We never allocate fence so how could we have to free one ? */
+ BUG();
+}
+
+static struct hmm_fence *hmm_dummy_update(struct hmm_mirror *mirror,
+ struct vm_area_struct *vma,
+ unsigned long faddr,
+ unsigned long laddr,
+ enum hmm_etype etype)
+{
+ struct hmm_dummy_mirror *dmirror;
+ struct hmm_dummy_pt_map pt_map = {0};
+ unsigned long addr, i, mask;
+
+ dmirror = container_of(mirror, struct hmm_dummy_mirror, mirror);
+ pt_map.dmirror = dmirror;
+
+ /* Sanity check for debugging hmm real device driver do not have to do that. */
+ switch (etype) {
+ case HMM_UNREGISTER:
+ case HMM_MUNMAP:
+ case HMM_MPROT_NONE:
+ mask = 0;
+ break;
+ case HMM_MPROT_RONLY:
+ mask = ~HMM_DUMMY_PTE_WRITE;
+ break;
+ default:
+ printk(KERN_ERR "%4d:%s invalid event type %d\n",
+ __LINE__, __func__, etype);
+ return ERR_PTR(-EIO);
+ }
+
+ mutex_lock(&dmirror->mutex);
+ for (i = 0, addr = faddr; addr < laddr; ++i, addr += PAGE_SIZE) {
+ unsigned long *pldp;
+
+ pldp = hmm_dummy_pt_pld_map(&pt_map, addr);
+ if (!pldp) {
+ continue;
+ }
+ if (((*pldp) & HMM_DUMMY_PTE_DIRTY)) {
+ struct page *page;
+
+ page = hmm_dummy_pte_to_page(*pldp);
+ if (page) {
+ set_page_dirty(page);
+ }
+ }
+ *pldp &= ~HMM_DUMMY_PTE_DIRTY;
+ *pldp &= mask;
+ }
+ hmm_dummy_pt_unmap(&pt_map);
+
+ switch (etype) {
+ case HMM_UNREGISTER:
+ case HMM_MUNMAP:
+ hmm_dummy_pt_free(dmirror, faddr, laddr);
+ break;
+ default:
+ break;
+ }
+ mutex_unlock(&dmirror->mutex);
+ return NULL;
+}
+
+static int hmm_dummy_fault(struct hmm_mirror *mirror,
+ unsigned long faddr,
+ unsigned long laddr,
+ pte_t *ptep,
+ struct hmm_event *event)
+{
+ struct hmm_dummy_mirror *dmirror;
+ struct hmm_dummy_pt_map pt_map = {0};
+ unsigned long i;
+ int ret = 0;
+
+ dmirror = container_of(mirror, struct hmm_dummy_mirror, mirror);
+ pt_map.dmirror = dmirror;
+
+ mutex_lock(&dmirror->mutex);
+ for (i = 0; faddr < laddr; ++i, ++ptep, faddr += PAGE_SIZE) {
+ unsigned long *pldp, pld_idx;
+ struct page *page;
+ bool write;
+
+ event->iaddr = faddr;
+ pldp = hmm_dummy_pt_pld_map(&pt_map, faddr);
+ if (!pldp) {
+ ret = -ENOMEM;
+ break;
+ }
+
+ page = hmm_pte_to_page(*ptep, &write);
+ if (!page) {
+ ret = -ENOENT;
+ break;
+ }
+ if (event->etype == HMM_WFAULT && !write) {
+ ret = -EACCES;
+ break;
+ }
+
+printk(KERN_INFO "%4d %16s [0x%016lx] 0x%016lx\n", __LINE__, __func__, faddr, page_to_pfn(page));
+ pld_idx = hmm_dummy_pld_index(faddr);
+ pldp[pld_idx] = (page_to_pfn(page) << HMM_DUMMY_PFN_SHIFT);
+ pldp[pld_idx] |= write ? HMM_DUMMY_PTE_WRITE : 0;
+ pldp[pld_idx] |= HMM_DUMMY_PTE_VALID | HMM_DUMMY_PTE_READ;
+ }
+ hmm_dummy_pt_unmap(&pt_map);
+ mutex_unlock(&dmirror->mutex);
+ return ret;
+}
+
+static const struct hmm_device_ops hmm_dummy_ops = {
+ .device_destroy = &hmm_dummy_device_destroy,
+ .mirror_release = &hmm_dummy_mirror_release,
+ .mirror_destroy = &hmm_dummy_mirror_destroy,
+ .fence_wait = &hmm_dummy_fence_wait,
+ .fence_destroy = &hmm_dummy_fence_destroy,
+ .update = &hmm_dummy_update,
+ .fault = &hmm_dummy_fault,
+};
+
+
+/* hmm_dummy_mmap - hmm dummy device file mmap operations.
+ *
+ * The hmm dummy driver does not allow mmap of its device file. The main reason
+ * is because the kernel lack the ability to insert page with specific custom
+ * protections inside a vma.
+ */
+static int hmm_dummy_mmap_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ return VM_FAULT_SIGBUS;
+}
+
+static void hmm_dummy_mmap_open(struct vm_area_struct *vma)
+{
+ /* nop */
+}
+
+static void hmm_dummy_mmap_close(struct vm_area_struct *vma)
+{
+ /* nop */
+}
+
+static const struct vm_operations_struct mmap_mem_ops = {
+ .fault = hmm_dummy_mmap_fault,
+ .open = hmm_dummy_mmap_open,
+ .close = hmm_dummy_mmap_close,
+};
+
+
+/* hmm_dummy_fops - hmm dummy device file operations.
+ *
+ * The hmm dummy driver allow to read/write to the mirrored process through
+ * the device file. Below are the read and write and others device file
+ * callback that implement access to the mirrored address space.
+ */
+static int hmm_dummy_mirror_fault(struct hmm_dummy_mirror *dmirror,
+ unsigned long addr,
+ bool write)
+{
+ struct hmm_mirror *mirror = &dmirror->mirror;
+ struct hmm_event event;
+ unsigned long faddr, laddr, npages = 4;
+ int ret;
+
+ /* Showcase hmm api fault a 64k range centered on the address. */
+ event.faddr = faddr = addr > (npages << 8) ? addr - (npages << 8) : 0;
+ event.laddr = laddr = faddr + (npages << 10);
+ event.etype = write ? HMM_WFAULT : HMM_RFAULT;
+
+ /* Pre-allocate device page table. */
+ mutex_lock(&dmirror->mutex);
+ ret = hmm_dummy_pt_alloc(dmirror, faddr, laddr);
+ mutex_unlock(&dmirror->mutex);
+ if (ret) {
+ return ret;
+ }
+
+ for (; faddr < laddr; faddr = event.faddr) {
+ ret = hmm_mirror_fault(mirror, &event);
+ /* Ignore any error that do not concern the fault address. */
+ if (addr >= event.laddr) {
+ event.faddr = event.laddr;
+ event.laddr = laddr;
+ continue;
+ }
+ if (addr < event.laddr) {
+ /* The address was faulted successfully ignore error
+ * for address above the one we were interested in.
+ */
+ ret = 0;
+ }
+ break;
+ }
+
+ return ret;
+}
+
+static ssize_t hmm_dummy_fops_read(struct file *filp,
+ char __user *buf,
+ size_t count,
+ loff_t *ppos)
+{
+ struct hmm_dummy_device *ddevice;
+ struct hmm_dummy_mirror *dmirror;
+ struct hmm_dummy_pt_map pt_map = {0};
+ unsigned long faddr, laddr, offset;
+ unsigned minor;
+ ssize_t retval = 0;
+ void *tmp;
+ long r;
+
+ tmp = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!tmp) {
+ return -ENOMEM;
+ }
+
+ /* Check if we are mirroring anything */
+ minor = iminor(file_inode(filp));
+ ddevice = filp->private_data;
+ mutex_lock(&ddevice->mutex);
+ if (ddevice->dmirrors[minor] == NULL) {
+ mutex_unlock(&ddevice->mutex);
+ kfree(tmp);
+ return 0;
+ }
+ dmirror = ddevice->dmirrors[minor];
+ mutex_unlock(&ddevice->mutex);
+ if (dmirror->stop) {
+ kfree(tmp);
+ return 0;
+ }
+
+ /* The range of address to lookup. */
+ faddr = (*ppos) & PAGE_MASK;
+ offset = (*ppos) - faddr;
+ laddr = PAGE_ALIGN(faddr + count);
+ BUG_ON(faddr == laddr);
+ pt_map.dmirror = dmirror;
+
+ for (; count; faddr += PAGE_SIZE, offset = 0) {
+ unsigned long *pldp, pld_idx;
+ unsigned long size = min(PAGE_SIZE - offset, count);
+ struct page *page;
+ char *ptr;
+
+ mutex_lock(&dmirror->mutex);
+ pldp = hmm_dummy_pt_pld_map(&pt_map, faddr);
+ pld_idx = hmm_dummy_pld_index(faddr);
+ if (!pldp || !(pldp[pld_idx] & HMM_DUMMY_PTE_VALID)) {
+ hmm_dummy_pt_unmap(&pt_map);
+ mutex_unlock(&dmirror->mutex);
+ goto fault;
+ }
+ page = hmm_dummy_pte_to_page(pldp[pld_idx]);
+ if (!page) {
+ mutex_unlock(&dmirror->mutex);
+ BUG();
+ kfree(tmp);
+ return -EFAULT;
+ }
+printk(KERN_INFO "%4d %16s [0x%016lx] 0x%016lx\n", __LINE__, __func__, faddr, page_to_pfn(page));
+ ptr = kmap(page);
+ memcpy(tmp, ptr + offset, size);
+ kunmap(page);
+ hmm_dummy_pt_unmap(&pt_map);
+ mutex_unlock(&dmirror->mutex);
+
+ r = copy_to_user(buf, tmp, size);
+ if (r) {
+ kfree(tmp);
+ return -EFAULT;
+ }
+ retval += size;
+ *ppos += size;
+ count -= size;
+ buf += size;
+ }
+
+ return retval;
+
+fault:
+ kfree(tmp);
+ r = hmm_dummy_mirror_fault(dmirror, faddr, false);
+ if (r) {
+ return r;
+ }
+
+ /* Force userspace to retry read if nothing was read. */
+ return retval ? retval : -EINTR;
+}
+
+static ssize_t hmm_dummy_fops_write(struct file *filp,
+ const char __user *buf,
+ size_t count,
+ loff_t *ppos)
+{
+ struct hmm_dummy_device *ddevice;
+ struct hmm_dummy_mirror *dmirror;
+ struct hmm_dummy_pt_map pt_map = {0};
+ unsigned long faddr, laddr, offset;
+ unsigned minor;
+ ssize_t retval = 0;
+ void *tmp;
+ long r;
+
+ tmp = kmalloc(PAGE_SIZE, GFP_KERNEL);
+ if (!tmp) {
+ return -ENOMEM;
+ }
+
+ /* Check if we are mirroring anything */
+ minor = iminor(file_inode(filp));
+ ddevice = filp->private_data;
+ mutex_lock(&ddevice->mutex);
+ if (ddevice->dmirrors[minor] == NULL) {
+ mutex_unlock(&ddevice->mutex);
+ kfree(tmp);
+ return 0;
+ }
+ dmirror = ddevice->dmirrors[minor];
+ mutex_unlock(&ddevice->mutex);
+ if (dmirror->stop) {
+ kfree(tmp);
+ return 0;
+ }
+
+ /* The range of address to lookup. */
+ faddr = (*ppos) & PAGE_MASK;
+ offset = (*ppos) - faddr;
+ laddr = PAGE_ALIGN(faddr + count);
+ BUG_ON(faddr == laddr);
+ pt_map.dmirror = dmirror;
+
+ for (; count; faddr += PAGE_SIZE, offset = 0) {
+ unsigned long *pldp, pld_idx;
+ unsigned long size = min(PAGE_SIZE - offset, count);
+ struct page *page;
+ char *ptr;
+
+ r = copy_from_user(tmp, buf, size);
+ if (r) {
+ kfree(tmp);
+ return -EFAULT;
+ }
+
+ mutex_lock(&dmirror->mutex);
+
+ pldp = hmm_dummy_pt_pld_map(&pt_map, faddr);
+ pld_idx = hmm_dummy_pld_index(faddr);
+ if (!pldp || !(pldp[pld_idx] & HMM_DUMMY_PTE_VALID)) {
+ hmm_dummy_pt_unmap(&pt_map);
+ mutex_unlock(&dmirror->mutex);
+ goto fault;
+ }
+ if (!(pldp[pld_idx] & HMM_DUMMY_PTE_WRITE)) {
+ hmm_dummy_pt_unmap(&pt_map);
+ mutex_unlock(&dmirror->mutex);
+ goto fault;
+ }
+ pldp[pld_idx] |= HMM_DUMMY_PTE_DIRTY;
+ page = hmm_dummy_pte_to_page(pldp[pld_idx]);
+ if (!page) {
+ mutex_unlock(&dmirror->mutex);
+ BUG();
+ kfree(tmp);
+ return -EFAULT;
+ }
+printk(KERN_INFO "%4d %16s [0x%016lx] 0x%016lx\n", __LINE__, __func__, faddr, page_to_pfn(page));
+ ptr = kmap(page);
+ memcpy(ptr + offset, tmp, size);
+ kunmap(page);
+ hmm_dummy_pt_unmap(&pt_map);
+ mutex_unlock(&dmirror->mutex);
+
+ retval += size;
+ *ppos += size;
+ count -= size;
+ buf += size;
+ }
+
+ kfree(tmp);
+ return retval;
+
+fault:
+ kfree(tmp);
+ r = hmm_dummy_mirror_fault(dmirror, faddr, true);
+ if (r) {
+ return r;
+ }
+
+ /* Force userspace to retry write if nothing was writen. */
+ return retval ? retval : -EINTR;
+}
+
+static int hmm_dummy_fops_mmap(struct file *filp, struct vm_area_struct *vma)
+{
+ return -EINVAL;
+}
+
+static int hmm_dummy_fops_open(struct inode *inode, struct file *filp)
+{
+ struct hmm_dummy_device *ddevice;
+ struct cdev *cdev = inode->i_cdev;
+ const int minor = iminor(inode);
+
+ /* No exclusive opens */
+ if (filp->f_flags & O_EXCL) {
+ return -EINVAL;
+ }
+
+ ddevice = container_of(cdev, struct hmm_dummy_device, cdev);
+ filp->private_data = ddevice;
+ ddevice->fmapping[minor] = &inode->i_data;
+
+ return 0;
+}
+
+static int hmm_dummy_fops_release(struct inode *inode,
+ struct file *filp)
+{
+ struct hmm_dummy_device *ddevice;
+ struct hmm_dummy_mirror *dmirror;
+ struct cdev *cdev = inode->i_cdev;
+ const int minor = iminor(inode);
+
+ ddevice = container_of(cdev, struct hmm_dummy_device, cdev);
+ dmirror = ddevice->dmirrors[minor];
+ if (dmirror && dmirror->filp == filp) {
+ if (!dmirror->stop) {
+ hmm_mirror_unregister(&dmirror->mirror);
+ }
+ ddevice->dmirrors[minor] = NULL;
+ kfree(dmirror);
+ }
+
+ return 0;
+}
+
+static long hmm_dummy_fops_unlocked_ioctl(struct file *filp,
+ unsigned int command,
+ unsigned long arg)
+{
+ struct hmm_dummy_device *ddevice;
+ struct hmm_dummy_mirror *dmirror;
+ unsigned minor;
+ int ret;
+
+ minor = iminor(file_inode(filp));
+ ddevice = filp->private_data;
+ switch (command) {
+ case HMM_DUMMY_EXPOSE_MM:
+ mutex_lock(&ddevice->mutex);
+ dmirror = ddevice->dmirrors[minor];
+ if (dmirror) {
+ mutex_unlock(&ddevice->mutex);
+ return -EBUSY;
+ }
+ /* Mirror this process address space */
+ dmirror = kzalloc(sizeof(*dmirror), GFP_KERNEL);
+ if (dmirror == NULL) {
+ mutex_unlock(&ddevice->mutex);
+ return -ENOMEM;
+ }
+ dmirror->mm = NULL;
+ dmirror->stop = false;
+ dmirror->pid = task_pid_nr(current);
+ dmirror->ddevice = ddevice;
+ dmirror->minor = minor;
+ dmirror->filp = filp;
+ dmirror->pgdp = NULL;
+ mutex_init(&dmirror->mutex);
+ ddevice->dmirrors[minor] = dmirror;
+ mutex_unlock(&ddevice->mutex);
+
+ ret = hmm_mirror_register(&dmirror->mirror,
+ &ddevice->device,
+ current->mm);
+ if (ret) {
+ mutex_lock(&ddevice->mutex);
+ ddevice->dmirrors[minor] = NULL;
+ mutex_unlock(&ddevice->mutex);
+ kfree(dmirror);
+ return ret;
+ }
+ /* Success. */
+ hmm_dummy_device_print(ddevice, dmirror->minor,
+ "mirroring address space of %d\n",
+ dmirror->pid);
+ return 0;
+ default:
+ return -EINVAL;
+ }
+ return 0;
+}
+
+static const struct file_operations hmm_dummy_fops = {
+ .read = hmm_dummy_fops_read,
+ .write = hmm_dummy_fops_write,
+ .mmap = hmm_dummy_fops_mmap,
+ .open = hmm_dummy_fops_open,
+ .release = hmm_dummy_fops_release,
+ .unlocked_ioctl = hmm_dummy_fops_unlocked_ioctl,
+ .llseek = default_llseek,
+ .owner = THIS_MODULE,
+};
+
+
+/*
+ * char device driver
+ */
+static int hmm_dummy_device_init(struct hmm_dummy_device *ddevice)
+{
+ int ret, i;
+
+ ret = alloc_chrdev_region(&ddevice->dev, 0,
+ HMM_DUMMY_DEVICE_MAX_MIRRORS,
+ ddevice->name);
+ if (ret < 0) {
+ printk(KERN_ERR "alloc_chrdev_region() failed for hmm_dummy\n");
+ goto error;
+ }
+ ddevice->major = MAJOR(ddevice->dev);
+
+ cdev_init(&ddevice->cdev, &hmm_dummy_fops);
+ ret = cdev_add(&ddevice->cdev, ddevice->dev, HMM_DUMMY_DEVICE_MAX_MIRRORS);
+ if (ret) {
+ unregister_chrdev_region(ddevice->dev, HMM_DUMMY_DEVICE_MAX_MIRRORS);
+ goto error;
+ }
+
+ /* Register the hmm device. */
+ for (i = 0; i < HMM_DUMMY_DEVICE_MAX_MIRRORS; i++) {
+ ddevice->dmirrors[i] = NULL;
+ }
+ mutex_init(&ddevice->mutex);
+ ddevice->device.ops = &hmm_dummy_ops;
+
+ ret = hmm_device_register(&ddevice->device,
+ ddevice->name);
+ if (ret) {
+ cdev_del(&ddevice->cdev);
+ unregister_chrdev_region(ddevice->dev, HMM_DUMMY_DEVICE_MAX_MIRRORS);
+ goto error;
+ }
+
+ return 0;
+
+error:
+ return ret;
+}
+
+static void hmm_dummy_device_fini(struct hmm_dummy_device *ddevice)
+{
+ unsigned i;
+
+ /* First finish hmm. */
+ for (i = 0; i < HMM_DUMMY_DEVICE_MAX_MIRRORS; i++) {
+ struct hmm_dummy_mirror *dmirror;
+
+ dmirror = ddevices->dmirrors[i];
+ if (!dmirror) {
+ continue;
+ }
+ hmm_mirror_unregister(&dmirror->mirror);
+ kfree(dmirror);
+ }
+ hmm_device_unref(&ddevice->device);
+
+ cdev_del(&ddevice->cdev);
+ unregister_chrdev_region(ddevice->dev,
+ HMM_DUMMY_DEVICE_MAX_MIRRORS);
+}
+
+static int __init hmm_dummy_init(void)
+{
+ int ret;
+
+ snprintf(ddevices[0].name, sizeof(ddevices[0].name),
+ "%s%d", HMM_DUMMY_DEVICE_NAME, 0);
+ ret = hmm_dummy_device_init(&ddevices[0]);
+ if (ret) {
+ return ret;
+ }
+
+ snprintf(ddevices[1].name, sizeof(ddevices[1].name),
+ "%s%d", HMM_DUMMY_DEVICE_NAME, 1);
+ ret = hmm_dummy_device_init(&ddevices[1]);
+ if (ret) {
+ hmm_dummy_device_fini(&ddevices[0]);
+ return ret;
+ }
+
+ printk(KERN_INFO "hmm_dummy loaded THIS IS A DANGEROUS MODULE !!!\n");
+ return 0;
+}
+
+static void __exit hmm_dummy_exit(void)
+{
+ hmm_dummy_device_fini(&ddevices[1]);
+ hmm_dummy_device_fini(&ddevices[0]);
+}
+
+module_init(hmm_dummy_init);
+module_exit(hmm_dummy_exit);
+MODULE_LICENSE("GPL");
diff --git a/include/uapi/linux/hmm_dummy.h b/include/uapi/linux/hmm_dummy.h
new file mode 100644
index 0000000..16ae0d3
--- /dev/null
+++ b/include/uapi/linux/hmm_dummy.h
@@ -0,0 +1,34 @@
+/*
+ * Copyright 2013 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Authors: Jérôme Glisse <jglisse@redhat.com>
+ */
+/* This is a dummy driver made to exercice the HMM (hardware memory management)
+ * API of the kernel. It allow an userspace program to map its whole address
+ * space through the hmm dummy driver file.
+ */
+#ifndef _UAPI_LINUX_HMM_DUMMY_H
+#define _UAPI_LINUX_HMM_DUMMY_H
+
+#include <linux/types.h>
+#include <linux/ioctl.h>
+#include <linux/irqnr.h>
+
+/* Expose the address space of the calling process through hmm dummy dev file */
+#define HMM_DUMMY_EXPOSE_MM _IO( 'R', 0x00 )
+
+#endif /* _UAPI_LINUX_RANDOM_H */
--
1.9.0
^ permalink raw reply [flat|nested] 5+ messages in thread