[PATCH 0/2] kmap cleanup 2

[PATCH 0/2] kmap cleanup 2

[ira.weiny]

From: Ira Weiny <ira.weiny@intel.com>

Continue the kmap clean up with 2 follow on patches

These apply after the kmap cleanup V2 series:

https://lore.kernel.org/lkml/20200504010912.982044-1-ira.weiny@intel.com/

Ira Weiny (2):
  kmap: Remove kmap_atomic_to_page()
  parisc/kmap: Remove duplicate kmap code

 arch/csky/include/asm/highmem.h      |  1 -
 arch/csky/mm/highmem.c               | 13 -------------
 arch/nds32/include/asm/highmem.h     |  1 -
 arch/parisc/include/asm/cacheflush.h | 28 ++--------------------------
 include/linux/highmem.h              | 10 +++++++---
 5 files changed, 9 insertions(+), 44 deletions(-)

-- 
2.25.1

[PATCH 1/2] kmap: Remove kmap_atomic_to_page()

[ira.weiny]

From: Ira Weiny <ira.weiny@intel.com>

kmap_atomic_to_page() has no callers and is only defined on 1 arch and
declared on another.  Remove it.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/csky/include/asm/highmem.h  |  1 -
 arch/csky/mm/highmem.c           | 13 -------------
 arch/nds32/include/asm/highmem.h |  1 -
 3 files changed, 15 deletions(-)

diff --git a/arch/csky/include/asm/highmem.h b/arch/csky/include/asm/highmem.h
index 263fbddcd0a3..ea2f3f39174d 100644
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -33,7 +33,6 @@ extern pte_t *pkmap_page_table;
 #define ARCH_HAS_KMAP_FLUSH_TLB
 extern void kmap_flush_tlb(unsigned long addr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
-extern struct page *kmap_atomic_to_page(void *ptr);
 
 #define flush_cache_kmaps() do {} while (0)
 
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 3ae5c8cd7619..3b3f622f5ae9 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -81,19 +81,6 @@ void *kmap_atomic_pfn(unsigned long pfn)
 	return (void *) vaddr;
 }
 
-struct page *kmap_atomic_to_page(void *ptr)
-{
-	unsigned long idx, vaddr = (unsigned long)ptr;
-	pte_t *pte;
-
-	if (vaddr < FIXADDR_START)
-		return virt_to_page(ptr);
-
-	idx = virt_to_fix(vaddr);
-	pte = kmap_pte - (idx - FIX_KMAP_BEGIN);
-	return pte_page(*pte);
-}
-
 static void __init kmap_pages_init(void)
 {
 	unsigned long vaddr;
diff --git a/arch/nds32/include/asm/highmem.h b/arch/nds32/include/asm/highmem.h
index 4d21308549c9..a48a6536d41a 100644
--- a/arch/nds32/include/asm/highmem.h
+++ b/arch/nds32/include/asm/highmem.h
@@ -52,7 +52,6 @@ extern void kmap_init(void);
  */
 #ifdef CONFIG_HIGHMEM
 extern void *kmap_atomic_pfn(unsigned long pfn);
-extern struct page *kmap_atomic_to_page(void *ptr);
 #endif
 
 #endif
-- 
2.25.1

[PATCH 2/2] parisc/kmap: Remove duplicate kmap code

[ira.weiny]

From: Ira Weiny <ira.weiny@intel.com>

parisc reimplements the kmap calls except to flush it's dcache.  This is
arguably an abuse of kmap but regardless it is messy and confusing.

Remove the duplicate code and have parisc define
ARCH_HAS_FLUSH_ON_KUNMAP for a kunmap_flush_on_unmap() architecture
specific call to flush the cache.

Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/parisc/include/asm/cacheflush.h | 28 ++--------------------------
 include/linux/highmem.h              | 10 +++++++---
 2 files changed, 9 insertions(+), 29 deletions(-)

diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index 119c9a7681bc..99663fc1f997 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -100,35 +100,11 @@ flush_anon_page(struct vm_area_struct *vma, struct page *page, unsigned long vma
 	}
 }
 
-#include <asm/kmap_types.h>
-
-#define ARCH_HAS_KMAP
-
-static inline void *kmap(struct page *page)
-{
-	might_sleep();
-	return page_address(page);
-}
-
-static inline void kunmap(struct page *page)
-{
-	flush_kernel_dcache_page_addr(page_address(page));
-}
-
-static inline void *kmap_atomic(struct page *page)
-{
-	preempt_disable();
-	pagefault_disable();
-	return page_address(page);
-}
-
-static inline void kunmap_atomic_high(void *addr)
+#define ARCH_HAS_FLUSH_ON_KUNMAP
+static inline void kunmap_flush_on_unmap(void *addr)
 {
 	flush_kernel_dcache_page_addr(addr);
 }
 
-#define kmap_atomic_prot(page, prot)	kmap_atomic(page)
-#define kmap_atomic_pfn(pfn)	kmap_atomic(pfn_to_page(pfn))
-
 #endif /* _PARISC_CACHEFLUSH_H */
 
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 89838306f50d..cc0c3904e501 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -129,7 +129,6 @@ static inline struct page *kmap_to_page(void *addr)
 
 static inline unsigned long totalhigh_pages(void) { return 0UL; }
 
-#ifndef ARCH_HAS_KMAP
 static inline void *kmap(struct page *page)
 {
 	might_sleep();
@@ -138,6 +137,9 @@ static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
+#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
+	kunmap_flush_on_unmap(page_address(page));
+#endif
 }
 
 static inline void *kmap_atomic(struct page *page)
@@ -150,14 +152,16 @@ static inline void *kmap_atomic(struct page *page)
 
 static inline void kunmap_atomic_high(void *addr)
 {
-	/* Nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
+	/* Mostly nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
 	 * handles re-enabling faults + preemption */
+#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
+	kunmap_flush_on_unmap(addr);
+#endif
 }
 
 #define kmap_atomic_pfn(pfn)	kmap_atomic(pfn_to_page(pfn))
 
 #define kmap_flush_unused()	do {} while(0)
-#endif
 
 #endif /* CONFIG_HIGHMEM */
 
-- 
2.25.1