[PATCH 2/3] mm: Support tlbbatch flush for a range of PTEs

[Barry Song <21cnbao@gmail.com>]

From: Barry Song <v-songbaohua@oppo.com>

This is a preparatory patch to support batch PTE unmapping in
`try_to_unmap_one`. It first introduces range handling for
`tlbbatch` flush. Currently, the range is always set to the size of
PAGE_SIZE.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shaoqin Huang <shahuang@redhat.com>
Cc: Gavin Shan <gshan@redhat.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Yosry Ahmed <yosryahmed@google.com>
Signed-off-by: Barry Song <v-songbaohua@oppo.com>
---
 arch/arm64/include/asm/tlbflush.h | 26 ++++++++++++++------------
 arch/arm64/mm/contpte.c           |  2 +-
 arch/x86/include/asm/tlbflush.h   |  3 ++-
 mm/rmap.c                         | 12 +++++++-----
 4 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index bc94e036a26b..f34e4fab5aa2 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -322,13 +322,6 @@ static inline bool arch_tlbbatch_should_defer(struct mm_struct *mm)
 	return true;
 }
 
-static inline void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch,
-					     struct mm_struct *mm,
-					     unsigned long uaddr)
-{
-	__flush_tlb_page_nosync(mm, uaddr);
-}
-
 /*
  * If mprotect/munmap/etc occurs during TLB batched flushing, we need to
  * synchronise all the TLBI issued with a DSB to avoid the race mentioned in
@@ -448,7 +441,7 @@ static inline bool __flush_tlb_range_limit_excess(unsigned long start,
 	return false;
 }
 
-static inline void __flush_tlb_range_nosync(struct vm_area_struct *vma,
+static inline void __flush_tlb_range_nosync(struct mm_struct *mm,
 				     unsigned long start, unsigned long end,
 				     unsigned long stride, bool last_level,
 				     int tlb_level)
@@ -460,12 +453,12 @@ static inline void __flush_tlb_range_nosync(struct vm_area_struct *vma,
 	pages = (end - start) >> PAGE_SHIFT;
 
 	if (__flush_tlb_range_limit_excess(start, end, pages, stride)) {
-		flush_tlb_mm(vma->vm_mm);
+		flush_tlb_mm(mm);
 		return;
 	}
 
 	dsb(ishst);
-	asid = ASID(vma->vm_mm);
+	asid = ASID(mm);
 
 	if (last_level)
 		__flush_tlb_range_op(vale1is, start, pages, stride, asid,
@@ -474,7 +467,7 @@ static inline void __flush_tlb_range_nosync(struct vm_area_struct *vma,
 		__flush_tlb_range_op(vae1is, start, pages, stride, asid,
 				     tlb_level, true, lpa2_is_enabled());
 
-	mmu_notifier_arch_invalidate_secondary_tlbs(vma->vm_mm, start, end);
+	mmu_notifier_arch_invalidate_secondary_tlbs(mm, start, end);
 }
 
 static inline void __flush_tlb_range(struct vm_area_struct *vma,
@@ -482,7 +475,7 @@ static inline void __flush_tlb_range(struct vm_area_struct *vma,
 				     unsigned long stride, bool last_level,
 				     int tlb_level)
 {
-	__flush_tlb_range_nosync(vma, start, end, stride,
+	__flush_tlb_range_nosync(vma->vm_mm, start, end, stride,
 				 last_level, tlb_level);
 	dsb(ish);
 }
@@ -533,6 +526,15 @@ static inline void __flush_tlb_kernel_pgtable(unsigned long kaddr)
 	dsb(ish);
 	isb();
 }
+
+static inline void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch,
+					     struct mm_struct *mm,
+					     unsigned long uaddr,
+					     unsigned long size)
+{
+	__flush_tlb_range_nosync(mm, uaddr, uaddr + size,
+				 PAGE_SIZE, true, 3);
+}
 #endif
 
 #endif
diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c
index 55107d27d3f8..bcac4f55f9c1 100644
--- a/arch/arm64/mm/contpte.c
+++ b/arch/arm64/mm/contpte.c
@@ -335,7 +335,7 @@ int contpte_ptep_clear_flush_young(struct vm_area_struct *vma,
 		 * eliding the trailing DSB applies here.
 		 */
 		addr = ALIGN_DOWN(addr, CONT_PTE_SIZE);
-		__flush_tlb_range_nosync(vma, addr, addr + CONT_PTE_SIZE,
+		__flush_tlb_range_nosync(vma->vm_mm, addr, addr + CONT_PTE_SIZE,
 					 PAGE_SIZE, true, 3);
 	}
 
diff --git a/arch/x86/include/asm/tlbflush.h b/arch/x86/include/asm/tlbflush.h
index 69e79fff41b8..cda35f53f544 100644
--- a/arch/x86/include/asm/tlbflush.h
+++ b/arch/x86/include/asm/tlbflush.h
@@ -279,7 +279,8 @@ static inline u64 inc_mm_tlb_gen(struct mm_struct *mm)
 
 static inline void arch_tlbbatch_add_pending(struct arch_tlbflush_unmap_batch *batch,
 					     struct mm_struct *mm,
-					     unsigned long uaddr)
+					     unsigned long uaddr,
+					     unsignd long size)
 {
 	inc_mm_tlb_gen(mm);
 	cpumask_or(&batch->cpumask, &batch->cpumask, mm_cpumask(mm));
diff --git a/mm/rmap.c b/mm/rmap.c
index de6b8c34e98c..365112af5291 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -672,7 +672,8 @@ void try_to_unmap_flush_dirty(void)
 	(TLB_FLUSH_BATCH_PENDING_MASK / 2)
 
 static void set_tlb_ubc_flush_pending(struct mm_struct *mm, pte_t pteval,
-				      unsigned long uaddr)
+				      unsigned long uaddr,
+				      unsigned long size)
 {
 	struct tlbflush_unmap_batch *tlb_ubc = &current->tlb_ubc;
 	int batch;
@@ -681,7 +682,7 @@ static void set_tlb_ubc_flush_pending(struct mm_struct *mm, pte_t pteval,
 	if (!pte_accessible(mm, pteval))
 		return;
 
-	arch_tlbbatch_add_pending(&tlb_ubc->arch, mm, uaddr);
+	arch_tlbbatch_add_pending(&tlb_ubc->arch, mm, uaddr, size);
 	tlb_ubc->flush_required = true;
 
 	/*
@@ -757,7 +758,8 @@ void flush_tlb_batched_pending(struct mm_struct *mm)
 }
 #else
 static void set_tlb_ubc_flush_pending(struct mm_struct *mm, pte_t pteval,
-				      unsigned long uaddr)
+				      unsigned long uaddr,
+				      unsigned long size)
 {
 }
 
@@ -1792,7 +1794,7 @@ static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
 				 */
 				pteval = ptep_get_and_clear(mm, address, pvmw.pte);
 
-				set_tlb_ubc_flush_pending(mm, pteval, address);
+				set_tlb_ubc_flush_pending(mm, pteval, address, PAGE_SIZE);
 			} else {
 				pteval = ptep_clear_flush(vma, address, pvmw.pte);
 			}
@@ -2164,7 +2166,7 @@ static bool try_to_migrate_one(struct folio *folio, struct vm_area_struct *vma,
 				 */
 				pteval = ptep_get_and_clear(mm, address, pvmw.pte);
 
-				set_tlb_ubc_flush_pending(mm, pteval, address);
+				set_tlb_ubc_flush_pending(mm, pteval, address, PAGE_SIZE);
 			} else {
 				pteval = ptep_clear_flush(vma, address, pvmw.pte);
 			}
-- 
2.39.3 (Apple Git-146)