[PATCH V2 00/11] Subject: Remove duplicated kmap code

[PATCH V2 00/11] Subject: Remove duplicated kmap code

[ira.weiny]

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

The kmap infrastructure has been copied almost verbatim to every architecture.
This series consolidates obvious duplicated code by defining core functions
which call into the architectures only when needed.

Some of the k[un]map_atomic() implementations have some similarities but the
similarities were not sufficient to warrant further changes.

In addition we remove a duplicate implementation of kmap() in DRM.

Testing was done by 0day to cover all the architectures I can't readily
build/test.

---
Changes from V1:
	Fix bisect-ability
	Update commit message and fix line lengths
	Remove unneded kunmap_atomic_high() declarations
	Remove unneded kmap_atomic_high() declarations
	collect reviews
	rebase to 5.7-rc4

Changes from V0:
	Define kmap_flush_tlb() and make kmap() truely arch independent.
	Redefine the k[un]map_atomic_* code to call into the architectures for
		high mem pages
	Ensure all architectures define kmap_prot, use it appropriately, and
		define kmap_atomic_prot()
	Remove drm implementation of kmap_atomic()

Ira Weiny (11):
  arch/kmap: Remove BUG_ON()
  arch/xtensa: Move kmap build bug out of the way
  arch/kmap: Remove redundant arch specific kmaps
  arch/kunmap: Remove duplicate kunmap implementations
  {x86,powerpc,microblaze}/kmap: Move preempt disable
  arch/kmap_atomic: Consolidate duplicate code
  arch/kunmap_atomic: Consolidate duplicate code
  arch/kmap: Ensure kmap_prot visibility
  arch/kmap: Don't hard code kmap_prot values
  arch/kmap: Define kmap_atomic_prot() for all arch's
  drm: Remove drm specific kmap_atomic code

 arch/arc/include/asm/highmem.h        | 15 -------
 arch/arc/mm/highmem.c                 | 28 +++---------
 arch/arm/include/asm/highmem.h        |  7 ---
 arch/arm/mm/highmem.c                 | 35 +++------------
 arch/csky/include/asm/highmem.h       |  9 +---
 arch/csky/mm/highmem.c                | 43 +++++--------------
 arch/microblaze/include/asm/highmem.h | 28 +-----------
 arch/microblaze/mm/highmem.c          | 16 ++-----
 arch/microblaze/mm/init.c             |  3 --
 arch/mips/include/asm/highmem.h       |  9 +---
 arch/mips/mm/cache.c                  |  6 +--
 arch/mips/mm/highmem.c                | 49 ++++-----------------
 arch/nds32/include/asm/highmem.h      |  7 ---
 arch/nds32/mm/highmem.c               | 39 +++--------------
 arch/parisc/include/asm/cacheflush.h  |  4 +-
 arch/powerpc/include/asm/highmem.h    | 29 +------------
 arch/powerpc/mm/highmem.c             | 21 ++-------
 arch/powerpc/mm/mem.c                 |  3 --
 arch/sparc/include/asm/highmem.h      | 22 ----------
 arch/sparc/mm/highmem.c               | 18 +++-----
 arch/x86/include/asm/highmem.h        |  9 ----
 arch/x86/mm/highmem_32.c              | 50 ++-------------------
 arch/xtensa/include/asm/highmem.h     | 27 ------------
 arch/xtensa/mm/highmem.c              | 22 ++++------
 drivers/gpu/drm/ttm/ttm_bo_util.c     | 56 ++----------------------
 drivers/gpu/drm/vmwgfx/vmwgfx_blit.c  | 16 +++----
 include/drm/ttm/ttm_bo_api.h          |  4 --
 include/linux/highmem.h               | 62 +++++++++++++++++++++++++--
 28 files changed, 140 insertions(+), 497 deletions(-)

-- 
2.25.1

[PATCH V2 01/11] arch/kmap: Remove BUG_ON()

[ira.weiny]

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

Replace the use of BUG_ON(in_interrupt()) in the kmap() and kunmap()
in favor of might_sleep().

Besides the benefits of might_sleep(), this normalizes the
implementations such that they can be made generic in subsequent
patches.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/arc/include/asm/highmem.h        | 2 +-
 arch/arc/mm/highmem.c                 | 2 +-
 arch/arm/mm/highmem.c                 | 2 +-
 arch/csky/mm/highmem.c                | 2 +-
 arch/microblaze/include/asm/highmem.h | 2 +-
 arch/mips/mm/highmem.c                | 2 +-
 arch/nds32/mm/highmem.c               | 2 +-
 arch/powerpc/include/asm/highmem.h    | 2 +-
 arch/sparc/include/asm/highmem.h      | 4 ++--
 arch/x86/mm/highmem_32.c              | 3 +--
 arch/xtensa/include/asm/highmem.h     | 4 ++--
 11 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/arch/arc/include/asm/highmem.h b/arch/arc/include/asm/highmem.h
index 1af00accb37f..042e92921c4c 100644
--- a/arch/arc/include/asm/highmem.h
+++ b/arch/arc/include/asm/highmem.h
@@ -45,7 +45,7 @@ static inline void flush_cache_kmaps(void)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index fc8849e4f72e..39ef7b9a3aa9 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -51,7 +51,7 @@ static pte_t * fixmap_page_table;
 
 void *kmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
 
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index a76f8ace9ce6..cc6eb79ef20c 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -42,7 +42,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 813129145f3d..690d678649d1 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -29,7 +29,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
index 332c78e15198..99ced7278b5c 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -66,7 +66,7 @@ static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index d08e6d7d533b..edd889f6cede 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -28,7 +28,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index 022779af6148..4c7c28e994ea 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -24,7 +24,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index a4b65b186ec6..529512f6d65a 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -74,7 +74,7 @@ static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
diff --git a/arch/sparc/include/asm/highmem.h b/arch/sparc/include/asm/highmem.h
index 18d776925c45..7dd2d4b3f980 100644
--- a/arch/sparc/include/asm/highmem.h
+++ b/arch/sparc/include/asm/highmem.h
@@ -55,7 +55,7 @@ void kunmap_high(struct page *page);
 
 static inline void *kmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
 	return kmap_high(page);
@@ -63,7 +63,7 @@ static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 0a1898b8552e..8af66382672b 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -15,8 +15,7 @@ EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
 {
-	if (in_interrupt())
-		BUG();
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h
index 04e9340eac4b..413848cc1e56 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -73,7 +73,7 @@ static inline void *kmap(struct page *page)
 	 */
 	BUILD_BUG_ON(PKMAP_BASE <
 		     TLBTEMP_BASE_1 + TLBTEMP_SIZE);
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
 	return kmap_high(page);
@@ -81,7 +81,7 @@ static inline void *kmap(struct page *page)
 
 static inline void kunmap(struct page *page)
 {
-	BUG_ON(in_interrupt());
+	might_sleep();
 	if (!PageHighMem(page))
 		return;
 	kunmap_high(page);
-- 
2.25.1

[PATCH V2 02/11] arch/xtensa: Move kmap build bug out of the way

[ira.weiny]

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

Move the kmap() build bug to kmap_init() to facilitate patches to lift
kmap() to the core.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from V1:
	combine code onto 1 line.
---
 arch/xtensa/include/asm/highmem.h | 5 -----
 arch/xtensa/mm/highmem.c          | 4 ++++
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h
index 413848cc1e56..a9587c85be85 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -68,11 +68,6 @@ void kunmap_high(struct page *page);
 
 static inline void *kmap(struct page *page)
 {
-	/* Check if this memory layout is broken because PKMAP overlaps
-	 * page table.
-	 */
-	BUILD_BUG_ON(PKMAP_BASE <
-		     TLBTEMP_BASE_1 + TLBTEMP_SIZE);
 	might_sleep();
 	if (!PageHighMem(page))
 		return page_address(page);
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index 184ceadccc1a..da734a2ed641 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -88,6 +88,10 @@ void __init kmap_init(void)
 {
 	unsigned long kmap_vstart;
 
+	/* Check if this memory layout is broken because PKMAP overlaps
+	 * page table.
+	 */
+	BUILD_BUG_ON(PKMAP_BASE < TLBTEMP_BASE_1 + TLBTEMP_SIZE);
 	/* cache the first kmap pte */
 	kmap_vstart = __fix_to_virt(FIX_KMAP_BEGIN);
 	kmap_pte = kmap_get_fixmap_pte(kmap_vstart);
-- 
2.25.1

[PATCH V2 03/11] arch/kmap: Remove redundant arch specific kmaps

[ira.weiny]

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

The kmap code for all the architectures is almost 100% identical.

Lift the common code to the core.  Use ARCH_HAS_KMAP_FLUSH_TLB to
indicate if an arch defines kmap_flush_tlb() and call if if needed.

This also has the benefit of changing kmap() on a number of
architectures to be an inline call rather than an actual function.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/arc/include/asm/highmem.h        |  2 --
 arch/arc/mm/highmem.c                 | 10 ----------
 arch/arm/include/asm/highmem.h        |  2 --
 arch/arm/mm/highmem.c                 |  9 ---------
 arch/csky/include/asm/highmem.h       |  4 ++--
 arch/csky/mm/highmem.c                | 14 ++++----------
 arch/microblaze/include/asm/highmem.h |  9 ---------
 arch/mips/include/asm/highmem.h       |  4 ++--
 arch/mips/mm/highmem.c                | 14 +++-----------
 arch/nds32/include/asm/highmem.h      |  2 --
 arch/nds32/mm/highmem.c               | 12 ------------
 arch/powerpc/include/asm/highmem.h    |  9 ---------
 arch/sparc/include/asm/highmem.h      |  9 ---------
 arch/x86/include/asm/highmem.h        |  2 --
 arch/x86/mm/highmem_32.c              |  9 ---------
 arch/xtensa/include/asm/highmem.h     |  9 ---------
 include/linux/highmem.h               | 18 ++++++++++++++++++
 17 files changed, 29 insertions(+), 109 deletions(-)

diff --git a/arch/arc/include/asm/highmem.h b/arch/arc/include/asm/highmem.h
index 042e92921c4c..96eb67c86961 100644
--- a/arch/arc/include/asm/highmem.h
+++ b/arch/arc/include/asm/highmem.h
@@ -30,8 +30,6 @@
 
 #include <asm/cacheflush.h>
 
-extern void *kmap(struct page *page);
-extern void *kmap_high(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void kunmap_high(struct page *page);
diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index 39ef7b9a3aa9..4db13a6b9f3b 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -49,16 +49,6 @@
 extern pte_t * pkmap_page_table;
 static pte_t * fixmap_page_table;
 
-void *kmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-
-	return kmap_high(page);
-}
-EXPORT_SYMBOL(kmap);
-
 void *kmap_atomic(struct page *page)
 {
 	int idx, cpu_idx;
diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index eb4e4207cd3c..c917522541de 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -20,7 +20,6 @@
 
 extern pte_t *pkmap_page_table;
 
-extern void *kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 
 /*
@@ -63,7 +62,6 @@ static inline void *kmap_high_get(struct page *page)
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void *kmap(struct page *page);
 extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index cc6eb79ef20c..e8ba37c36590 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -31,15 +31,6 @@ static inline pte_t get_fixmap_pte(unsigned long vaddr)
 	return *ptep;
 }
 
-void *kmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	return kmap_high(page);
-}
-EXPORT_SYMBOL(kmap);
-
 void kunmap(struct page *page)
 {
 	might_sleep();
diff --git a/arch/csky/include/asm/highmem.h b/arch/csky/include/asm/highmem.h
index a345a2f2c22e..9d0516e38110 100644
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -30,10 +30,10 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void *kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 
-extern void *kmap(struct page *page);
+#define ARCH_HAS_KMAP_FLUSH_TLB
+extern void kmap_flush_tlb(unsigned long addr);
 extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 690d678649d1..4a3c273bc8b9 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -13,18 +13,12 @@ static pte_t *kmap_pte;
 
 unsigned long highstart_pfn, highend_pfn;
 
-void *kmap(struct page *page)
+void kmap_flush_tlb(unsigned long addr)
 {
-	void *addr;
-
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	addr = kmap_high(page);
-	flush_tlb_one((unsigned long)addr);
-
-	return addr;
+	flush_tlb_one(addr);
 }
+EXPORT_SYMBOL(kmap_flush_tlb);
+
 EXPORT_SYMBOL(kmap);
 
 void kunmap(struct page *page)
diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
index 99ced7278b5c..8c5bfd228bd8 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -51,19 +51,10 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void *kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
 extern void __kunmap_atomic(void *kvaddr);
 
-static inline void *kmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	return kmap_high(page);
-}
-
 static inline void kunmap(struct page *page)
 {
 	might_sleep();
diff --git a/arch/mips/include/asm/highmem.h b/arch/mips/include/asm/highmem.h
index 9d84aafc33d0..1f741e3ecabf 100644
--- a/arch/mips/include/asm/highmem.h
+++ b/arch/mips/include/asm/highmem.h
@@ -46,10 +46,10 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)	((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)	(PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void * kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 
-extern void *kmap(struct page *page);
+#define ARCH_HAS_KMAP_FLUSH_TLB
+extern void kmap_flush_tlb(unsigned long addr);
 extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index edd889f6cede..c72058bfead6 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -12,19 +12,11 @@ static pte_t *kmap_pte;
 
 unsigned long highstart_pfn, highend_pfn;
 
-void *kmap(struct page *page)
+void kmap_flush_tlb(unsigned long addr)
 {
-	void *addr;
-
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	addr = kmap_high(page);
-	flush_tlb_one((unsigned long)addr);
-
-	return addr;
+	flush_tlb_one(addr);
 }
-EXPORT_SYMBOL(kmap);
+EXPORT_SYMBOL(kmap_flush_tlb);
 
 void kunmap(struct page *page)
 {
diff --git a/arch/nds32/include/asm/highmem.h b/arch/nds32/include/asm/highmem.h
index b3a82c97ded3..b13654a79069 100644
--- a/arch/nds32/include/asm/highmem.h
+++ b/arch/nds32/include/asm/highmem.h
@@ -44,7 +44,6 @@ extern unsigned long highstart_pfn, highend_pfn;
 
 extern pte_t *pkmap_page_table;
 
-extern void *kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 
 extern void kmap_init(void);
@@ -54,7 +53,6 @@ extern void kmap_init(void);
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void *kmap(struct page *page);
 extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index 4c7c28e994ea..d0cde53b84ae 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -10,18 +10,6 @@
 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 
-void *kmap(struct page *page)
-{
-	unsigned long vaddr;
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	vaddr = (unsigned long)kmap_high(page);
-	return (void *)vaddr;
-}
-
-EXPORT_SYMBOL(kmap);
-
 void kunmap(struct page *page)
 {
 	might_sleep();
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index 529512f6d65a..f14e4feef6d5 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -59,19 +59,10 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void *kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
 extern void __kunmap_atomic(void *kvaddr);
 
-static inline void *kmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	return kmap_high(page);
-}
-
 static inline void kunmap(struct page *page)
 {
 	might_sleep();
diff --git a/arch/sparc/include/asm/highmem.h b/arch/sparc/include/asm/highmem.h
index 7dd2d4b3f980..2ff1192047f7 100644
--- a/arch/sparc/include/asm/highmem.h
+++ b/arch/sparc/include/asm/highmem.h
@@ -50,17 +50,8 @@ void kmap_init(void) __init;
 
 #define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
 
-void *kmap_high(struct page *page);
 void kunmap_high(struct page *page);
 
-static inline void *kmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	return kmap_high(page);
-}
-
 static inline void kunmap(struct page *page)
 {
 	might_sleep();
diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index a8059930056d..c916a28a9738 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -58,10 +58,8 @@ extern unsigned long highstart_pfn, highend_pfn;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void *kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 
-void *kmap(struct page *page);
 void kunmap(struct page *page);
 
 void *kmap_atomic_prot(struct page *page, pgprot_t prot);
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 8af66382672b..12591a81b85c 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -4,15 +4,6 @@
 #include <linux/swap.h> /* for totalram_pages */
 #include <linux/memblock.h>
 
-void *kmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	return kmap_high(page);
-}
-EXPORT_SYMBOL(kmap);
-
 void kunmap(struct page *page)
 {
 	might_sleep();
diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h
index a9587c85be85..2546b88ddecf 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -63,17 +63,8 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color)
 
 extern pte_t *pkmap_page_table;
 
-void *kmap_high(struct page *page);
 void kunmap_high(struct page *page);
 
-static inline void *kmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	return kmap_high(page);
-}
-
 static inline void kunmap(struct page *page)
 {
 	might_sleep();
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index ea5cdbd8c2c3..fc3adc51254a 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -34,6 +34,24 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
 #ifdef CONFIG_HIGHMEM
 #include <asm/highmem.h>
 
+#ifndef ARCH_HAS_KMAP_FLUSH_TLB
+static inline void kmap_flush_tlb(unsigned long addr) { }
+#endif
+
+void *kmap_high(struct page *page);
+static inline void *kmap(struct page *page)
+{
+	void *addr;
+
+	might_sleep();
+	if (!PageHighMem(page))
+		addr = page_address(page);
+	else
+		addr = kmap_high(page);
+	kmap_flush_tlb((unsigned long)addr);
+	return addr;
+}
+
 /* declarations for linux/mm/highmem.c */
 unsigned int nr_free_highpages(void);
 extern atomic_long_t _totalhigh_pages;
-- 
2.25.1

[PATCH V2 04/11] arch/kunmap: Remove duplicate kunmap implementations

[ira.weiny]

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

All architectures do exactly the same thing for kunmap(); remove all the
duplicate definitions and lift the call to the core.

This also has the benefit of changing kmap_unmap() on a number of
architectures to be an inline call rather than an actual function.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/arc/include/asm/highmem.h        | 10 ----------
 arch/arm/include/asm/highmem.h        |  3 ---
 arch/arm/mm/highmem.c                 |  9 ---------
 arch/csky/include/asm/highmem.h       |  3 ---
 arch/csky/mm/highmem.c                |  9 ---------
 arch/microblaze/include/asm/highmem.h |  9 ---------
 arch/mips/include/asm/highmem.h       |  3 ---
 arch/mips/mm/highmem.c                |  9 ---------
 arch/nds32/include/asm/highmem.h      |  3 ---
 arch/nds32/mm/highmem.c               | 10 ----------
 arch/powerpc/include/asm/highmem.h    |  9 ---------
 arch/sparc/include/asm/highmem.h      | 10 ----------
 arch/x86/include/asm/highmem.h        |  4 ----
 arch/x86/mm/highmem_32.c              |  9 ---------
 arch/xtensa/include/asm/highmem.h     | 10 ----------
 include/linux/highmem.h               |  9 +++++++++
 16 files changed, 9 insertions(+), 110 deletions(-)

diff --git a/arch/arc/include/asm/highmem.h b/arch/arc/include/asm/highmem.h
index 96eb67c86961..8387a5596a91 100644
--- a/arch/arc/include/asm/highmem.h
+++ b/arch/arc/include/asm/highmem.h
@@ -32,7 +32,6 @@
 
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
-extern void kunmap_high(struct page *page);
 
 extern void kmap_init(void);
 
@@ -41,15 +40,6 @@ static inline void flush_cache_kmaps(void)
 	flush_cache_all();
 }
 
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
-
 #endif
 
 #endif
diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index c917522541de..736f65283e7b 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -20,8 +20,6 @@
 
 extern pte_t *pkmap_page_table;
 
-extern void kunmap_high(struct page *page);
-
 /*
  * The reason for kmap_high_get() is to ensure that the currently kmap'd
  * page usage count does not decrease to zero while we're using its
@@ -62,7 +60,6 @@ static inline void *kmap_high_get(struct page *page)
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index e8ba37c36590..c700b32350ee 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -31,15 +31,6 @@ static inline pte_t get_fixmap_pte(unsigned long vaddr)
 	return *ptep;
 }
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-EXPORT_SYMBOL(kunmap);
-
 void *kmap_atomic(struct page *page)
 {
 	unsigned int idx;
diff --git a/arch/csky/include/asm/highmem.h b/arch/csky/include/asm/highmem.h
index 9d0516e38110..be11c5b67122 100644
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -30,11 +30,8 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
-
 #define ARCH_HAS_KMAP_FLUSH_TLB
 extern void kmap_flush_tlb(unsigned long addr);
-extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 4a3c273bc8b9..e9952211264b 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -21,15 +21,6 @@ EXPORT_SYMBOL(kmap_flush_tlb);
 
 EXPORT_SYMBOL(kmap);
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-EXPORT_SYMBOL(kunmap);
-
 void *kmap_atomic(struct page *page)
 {
 	unsigned long vaddr;
diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
index 8c5bfd228bd8..0c94046f2d58 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -51,18 +51,9 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
 extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
 extern void __kunmap_atomic(void *kvaddr);
 
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
 static inline void *kmap_atomic(struct page *page)
 {
 	return kmap_atomic_prot(page, kmap_prot);
diff --git a/arch/mips/include/asm/highmem.h b/arch/mips/include/asm/highmem.h
index 1f741e3ecabf..24e7e7e5cc7b 100644
--- a/arch/mips/include/asm/highmem.h
+++ b/arch/mips/include/asm/highmem.h
@@ -46,11 +46,8 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)	((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)	(PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
-
 #define ARCH_HAS_KMAP_FLUSH_TLB
 extern void kmap_flush_tlb(unsigned long addr);
-extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index c72058bfead6..eb8ec8493f2f 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -18,15 +18,6 @@ void kmap_flush_tlb(unsigned long addr)
 }
 EXPORT_SYMBOL(kmap_flush_tlb);
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-EXPORT_SYMBOL(kunmap);
-
 /*
  * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
  * no global lock is needed and because the kmap code must perform a global TLB
diff --git a/arch/nds32/include/asm/highmem.h b/arch/nds32/include/asm/highmem.h
index b13654a79069..c93c7368bb3f 100644
--- a/arch/nds32/include/asm/highmem.h
+++ b/arch/nds32/include/asm/highmem.h
@@ -44,8 +44,6 @@ extern unsigned long highstart_pfn, highend_pfn;
 
 extern pte_t *pkmap_page_table;
 
-extern void kunmap_high(struct page *page);
-
 extern void kmap_init(void);
 
 /*
@@ -53,7 +51,6 @@ extern void kmap_init(void);
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index d0cde53b84ae..f9348bec0ecb 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -10,16 +10,6 @@
 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
-EXPORT_SYMBOL(kunmap);
-
 void *kmap_atomic(struct page *page)
 {
 	unsigned int idx;
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index f14e4feef6d5..ba3371977d49 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -59,18 +59,9 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
 extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
 extern void __kunmap_atomic(void *kvaddr);
 
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
 static inline void *kmap_atomic(struct page *page)
 {
 	return kmap_atomic_prot(page, kmap_prot);
diff --git a/arch/sparc/include/asm/highmem.h b/arch/sparc/include/asm/highmem.h
index 2ff1192047f7..4bdb79fed02c 100644
--- a/arch/sparc/include/asm/highmem.h
+++ b/arch/sparc/include/asm/highmem.h
@@ -50,16 +50,6 @@ void kmap_init(void) __init;
 
 #define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
 
-void kunmap_high(struct page *page);
-
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
 void *kmap_atomic(struct page *page);
 void __kunmap_atomic(void *kvaddr);
 
diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index c916a28a9738..90b96594d6c5 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -58,10 +58,6 @@ extern unsigned long highstart_pfn, highend_pfn;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void kunmap_high(struct page *page);
-
-void kunmap(struct page *page);
-
 void *kmap_atomic_prot(struct page *page, pgprot_t prot);
 void *kmap_atomic(struct page *page);
 void __kunmap_atomic(void *kvaddr);
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 12591a81b85c..c4ebfd0ae401 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -4,15 +4,6 @@
 #include <linux/swap.h> /* for totalram_pages */
 #include <linux/memblock.h>
 
-void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-EXPORT_SYMBOL(kunmap);
-
 /*
  * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
  * no global lock is needed and because the kmap code must perform a global TLB
diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h
index 2546b88ddecf..5a481f7def0b 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -63,16 +63,6 @@ static inline wait_queue_head_t *get_pkmap_wait_queue_head(unsigned int color)
 
 extern pte_t *pkmap_page_table;
 
-void kunmap_high(struct page *page);
-
-static inline void kunmap(struct page *page)
-{
-	might_sleep();
-	if (!PageHighMem(page))
-		return;
-	kunmap_high(page);
-}
-
 static inline void flush_cache_kmaps(void)
 {
 	flush_cache_all();
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index fc3adc51254a..ae6e8cb81043 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -52,6 +52,15 @@ static inline void *kmap(struct page *page)
 	return addr;
 }
 
+void kunmap_high(struct page *page);
+static inline void kunmap(struct page *page)
+{
+	might_sleep();
+	if (!PageHighMem(page))
+		return;
+	kunmap_high(page);
+}
+
 /* declarations for linux/mm/highmem.c */
 unsigned int nr_free_highpages(void);
 extern atomic_long_t _totalhigh_pages;
-- 
2.25.1

[PATCH V2 05/11] {x86,powerpc,microblaze}/kmap: Move preempt disable

[ira.weiny]

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

During this kmap() conversion series we must maintain bisect-ability.
To do this, kmap_atomic_prot() in x86, powerpc, and microblaze need to
remain functional.

Create a temporary inline version of kmap_atomic_prot within these
architectures so we can rework their kmap_atomic() calls and then lift
kmap_atomic_prot() to the core.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from V1:
	New patch
---
 arch/microblaze/include/asm/highmem.h | 11 ++++++++++-
 arch/microblaze/mm/highmem.c          | 10 ++--------
 arch/powerpc/include/asm/highmem.h    | 11 ++++++++++-
 arch/powerpc/mm/highmem.c             |  9 ++-------
 arch/x86/include/asm/highmem.h        | 11 ++++++++++-
 arch/x86/mm/highmem_32.c              | 10 ++--------
 6 files changed, 36 insertions(+), 26 deletions(-)

diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
index 0c94046f2d58..ec9954b091e1 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -51,7 +51,16 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
+extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
+void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+	preempt_disable();
+	pagefault_disable();
+	if (!PageHighMem(page))
+		return page_address(page);
+
+	return kmap_atomic_high_prot(page, prot);
+}
 extern void __kunmap_atomic(void *kvaddr);
 
 static inline void *kmap_atomic(struct page *page)
diff --git a/arch/microblaze/mm/highmem.c b/arch/microblaze/mm/highmem.c
index d7569f77fa15..0e3efaa8a004 100644
--- a/arch/microblaze/mm/highmem.c
+++ b/arch/microblaze/mm/highmem.c
@@ -32,18 +32,12 @@
  */
 #include <asm/tlbflush.h>
 
-void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 
 	unsigned long vaddr;
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
-
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
@@ -55,7 +49,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 
 	return (void *) vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic_prot);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void __kunmap_atomic(void *kvaddr)
 {
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index ba3371977d49..d049806a8354 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -59,7 +59,16 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
+extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+	preempt_disable();
+	pagefault_disable();
+	if (!PageHighMem(page))
+		return page_address(page);
+
+	return kmap_atomic_high_prot(page, prot);
+}
 extern void __kunmap_atomic(void *kvaddr);
 
 static inline void *kmap_atomic(struct page *page)
diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c
index 320c1672b2ae..f075cef6d663 100644
--- a/arch/powerpc/mm/highmem.c
+++ b/arch/powerpc/mm/highmem.c
@@ -30,16 +30,11 @@
  * be used in IRQ contexts, so in some (very limited) cases we need
  * it.
  */
-void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	unsigned long vaddr;
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
@@ -49,7 +44,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 
 	return (void*) vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic_prot);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void __kunmap_atomic(void *kvaddr)
 {
diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index 90b96594d6c5..61f47fef40e5 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -58,7 +58,16 @@ extern unsigned long highstart_pfn, highend_pfn;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-void *kmap_atomic_prot(struct page *page, pgprot_t prot);
+extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+{
+	preempt_disable();
+	pagefault_disable();
+	if (!PageHighMem(page))
+		return page_address(page);
+
+	return kmap_atomic_high_prot(page, prot);
+}
 void *kmap_atomic(struct page *page);
 void __kunmap_atomic(void *kvaddr);
 void *kmap_atomic_pfn(unsigned long pfn);
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index c4ebfd0ae401..48b56b1af902 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -12,17 +12,11 @@
  * However when holding an atomic kmap it is not legal to sleep, so atomic
  * kmaps are appropriate for short, tight code paths only.
  */
-void *kmap_atomic_prot(struct page *page, pgprot_t prot)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	unsigned long vaddr;
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-
-	if (!PageHighMem(page))
-		return page_address(page);
-
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
@@ -32,7 +26,7 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 
 	return (void *)vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic_prot);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void *kmap_atomic(struct page *page)
 {
-- 
2.25.1

Re: [PATCH V2 05/11] {x86,powerpc,microblaze}/kmap: Move preempt disable

[Christoph Hellwig]

On Sun, May 03, 2020 at 06:09:06PM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> During this kmap() conversion series we must maintain bisect-ability.
> To do this, kmap_atomic_prot() in x86, powerpc, and microblaze need to
> remain functional.
> 
> Create a temporary inline version of kmap_atomic_prot within these
> architectures so we can rework their kmap_atomic() calls and then lift
> kmap_atomic_prot() to the core.
> 
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> 
> ---
> Changes from V1:
> 	New patch
> ---
>  arch/microblaze/include/asm/highmem.h | 11 ++++++++++-
>  arch/microblaze/mm/highmem.c          | 10 ++--------
>  arch/powerpc/include/asm/highmem.h    | 11 ++++++++++-
>  arch/powerpc/mm/highmem.c             |  9 ++-------
>  arch/x86/include/asm/highmem.h        | 11 ++++++++++-
>  arch/x86/mm/highmem_32.c              | 10 ++--------
>  6 files changed, 36 insertions(+), 26 deletions(-)
> 
> diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
> index 0c94046f2d58..ec9954b091e1 100644
> --- a/arch/microblaze/include/asm/highmem.h
> +++ b/arch/microblaze/include/asm/highmem.h
> @@ -51,7 +51,16 @@ extern pte_t *pkmap_page_table;
>  #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
>  #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
>  
> -extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
> +extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
> +void *kmap_atomic_prot(struct page *page, pgprot_t prot)

Shouldn't this be marked inline?

The rest looks fine:

Reviewed-by: Christoph Hellwig <hch@lst.de>

Re: [PATCH V2 05/11] {x86,powerpc,microblaze}/kmap: Move preempt disable

[Ira Weiny]

On Tue, May 05, 2020 at 11:11:13PM -0700, Christoph Hellwig wrote:
> On Sun, May 03, 2020 at 06:09:06PM -0700, ira.weiny@intel.com wrote:
> > From: Ira Weiny <ira.weiny@intel.com>
> > 
> > During this kmap() conversion series we must maintain bisect-ability.
> > To do this, kmap_atomic_prot() in x86, powerpc, and microblaze need to
> > remain functional.
> > 
> > Create a temporary inline version of kmap_atomic_prot within these
> > architectures so we can rework their kmap_atomic() calls and then lift
> > kmap_atomic_prot() to the core.
> > 
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> > 
> > ---
> > Changes from V1:
> > 	New patch
> > ---
> >  arch/microblaze/include/asm/highmem.h | 11 ++++++++++-
> >  arch/microblaze/mm/highmem.c          | 10 ++--------
> >  arch/powerpc/include/asm/highmem.h    | 11 ++++++++++-
> >  arch/powerpc/mm/highmem.c             |  9 ++-------
> >  arch/x86/include/asm/highmem.h        | 11 ++++++++++-
> >  arch/x86/mm/highmem_32.c              | 10 ++--------
> >  6 files changed, 36 insertions(+), 26 deletions(-)
> > 
> > diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
> > index 0c94046f2d58..ec9954b091e1 100644
> > --- a/arch/microblaze/include/asm/highmem.h
> > +++ b/arch/microblaze/include/asm/highmem.h
> > @@ -51,7 +51,16 @@ extern pte_t *pkmap_page_table;
> >  #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
> >  #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
> >  
> > -extern void *kmap_atomic_prot(struct page *page, pgprot_t prot);
> > +extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
> > +void *kmap_atomic_prot(struct page *page, pgprot_t prot)
> 
> Shouldn't this be marked inline?

Yes Thanks.  Done.

> 
> The rest looks fine:
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Thanks,
Ira

[PATCH V2 06/11] arch/kmap_atomic: Consolidate duplicate code

[ira.weiny]

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

Every arch has the same code to ensure atomic operations and a check for
!HIGHMEM page.

Remove the duplicate code by defining a core kmap_atomic() which only
calls the arch specific kmap_atomic_high() when the page is high memory.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from V1:
	Adjust to preserve bisect-ability
	Remove unneeded kmap_atomic_high declarations
---
 arch/arc/include/asm/highmem.h        |  1 -
 arch/arc/mm/highmem.c                 |  9 ++-------
 arch/arm/include/asm/highmem.h        |  1 -
 arch/arm/mm/highmem.c                 |  9 ++-------
 arch/csky/include/asm/highmem.h       |  1 -
 arch/csky/mm/highmem.c                |  9 ++-------
 arch/microblaze/include/asm/highmem.h |  4 ++--
 arch/mips/include/asm/highmem.h       |  1 -
 arch/mips/mm/cache.c                  |  2 +-
 arch/mips/mm/highmem.c                | 18 ++----------------
 arch/nds32/include/asm/highmem.h      |  1 -
 arch/nds32/mm/highmem.c               |  9 ++-------
 arch/powerpc/include/asm/highmem.h    |  4 ++--
 arch/powerpc/mm/highmem.c             |  6 ------
 arch/sparc/include/asm/highmem.h      |  1 -
 arch/sparc/mm/highmem.c               |  9 ++-------
 arch/x86/include/asm/highmem.h        |  5 ++++-
 arch/x86/mm/highmem_32.c              | 14 --------------
 arch/xtensa/include/asm/highmem.h     |  1 -
 arch/xtensa/mm/highmem.c              |  9 ++-------
 include/linux/highmem.h               | 23 +++++++++++++++++++++++
 21 files changed, 46 insertions(+), 91 deletions(-)

diff --git a/arch/arc/include/asm/highmem.h b/arch/arc/include/asm/highmem.h
index 8387a5596a91..db425cd38545 100644
--- a/arch/arc/include/asm/highmem.h
+++ b/arch/arc/include/asm/highmem.h
@@ -30,7 +30,6 @@
 
 #include <asm/cacheflush.h>
 
-extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 
 extern void kmap_init(void);
diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index 4db13a6b9f3b..0964b011c29f 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -49,16 +49,11 @@
 extern pte_t * pkmap_page_table;
 static pte_t * fixmap_page_table;
 
-void *kmap_atomic(struct page *page)
+void *kmap_atomic_high(struct page *page)
 {
 	int idx, cpu_idx;
 	unsigned long vaddr;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
 	cpu_idx = kmap_atomic_idx_push();
 	idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
 	vaddr = FIXMAP_ADDR(idx);
@@ -68,7 +63,7 @@ void *kmap_atomic(struct page *page)
 
 	return (void *)vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_high);
 
 void __kunmap_atomic(void *kv)
 {
diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index 736f65283e7b..8c80bfe18a34 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -60,7 +60,6 @@ static inline void *kmap_high_get(struct page *page)
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
 #endif
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index c700b32350ee..075fdc235091 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -31,18 +31,13 @@ static inline pte_t get_fixmap_pte(unsigned long vaddr)
 	return *ptep;
 }
 
-void *kmap_atomic(struct page *page)
+void *kmap_atomic_high(struct page *page)
 {
 	unsigned int idx;
 	unsigned long vaddr;
 	void *kmap;
 	int type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
 #ifdef CONFIG_DEBUG_HIGHMEM
 	/*
 	 * There is no cache coherency issue when non VIVT, so force the
@@ -76,7 +71,7 @@ void *kmap_atomic(struct page *page)
 
 	return (void *)vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_high);
 
 void __kunmap_atomic(void *kvaddr)
 {
diff --git a/arch/csky/include/asm/highmem.h b/arch/csky/include/asm/highmem.h
index be11c5b67122..8ceee12f9bc1 100644
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -32,7 +32,6 @@ extern pte_t *pkmap_page_table;
 
 #define ARCH_HAS_KMAP_FLUSH_TLB
 extern void kmap_flush_tlb(unsigned long addr);
-extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
 extern struct page *kmap_atomic_to_page(void *ptr);
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index e9952211264b..63d74b47eee6 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -21,16 +21,11 @@ EXPORT_SYMBOL(kmap_flush_tlb);
 
 EXPORT_SYMBOL(kmap);
 
-void *kmap_atomic(struct page *page)
+void *kmap_atomic_high(struct page *page)
 {
 	unsigned long vaddr;
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
@@ -42,7 +37,7 @@ void *kmap_atomic(struct page *page)
 
 	return (void *)vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_high);
 
 void __kunmap_atomic(void *kvaddr)
 {
diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
index ec9954b091e1..00c75a423ac4 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -63,9 +63,9 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 }
 extern void __kunmap_atomic(void *kvaddr);
 
-static inline void *kmap_atomic(struct page *page)
+static inline void *kmap_atomic_high(struct page *page)
 {
-	return kmap_atomic_prot(page, kmap_prot);
+	return kmap_atomic_high_prot(page, kmap_prot);
 }
 
 #define flush_cache_kmaps()	{ flush_icache(); flush_dcache(); }
diff --git a/arch/mips/include/asm/highmem.h b/arch/mips/include/asm/highmem.h
index 24e7e7e5cc7b..8bdbbfc322ad 100644
--- a/arch/mips/include/asm/highmem.h
+++ b/arch/mips/include/asm/highmem.h
@@ -48,7 +48,6 @@ extern pte_t *pkmap_page_table;
 
 #define ARCH_HAS_KMAP_FLUSH_TLB
 extern void kmap_flush_tlb(unsigned long addr);
-extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
 
diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index 33b409391ddb..f015bb51fab0 100644
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -14,9 +14,9 @@
 #include <linux/sched.h>
 #include <linux/syscalls.h>
 #include <linux/mm.h>
+#include <linux/highmem.h>
 
 #include <asm/cacheflush.h>
-#include <asm/highmem.h>
 #include <asm/processor.h>
 #include <asm/cpu.h>
 #include <asm/cpu-features.h>
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index eb8ec8493f2f..2bda56372995 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -18,25 +18,11 @@ void kmap_flush_tlb(unsigned long addr)
 }
 EXPORT_SYMBOL(kmap_flush_tlb);
 
-/*
- * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
- * no global lock is needed and because the kmap code must perform a global TLB
- * invalidation when the kmap pool wraps.
- *
- * However when holding an atomic kmap is is not legal to sleep, so atomic
- * kmaps are appropriate for short, tight code paths only.
- */
-
-void *kmap_atomic(struct page *page)
+void *kmap_atomic_high(struct page *page)
 {
 	unsigned long vaddr;
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
@@ -48,7 +34,7 @@ void *kmap_atomic(struct page *page)
 
 	return (void*) vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_high);
 
 void __kunmap_atomic(void *kvaddr)
 {
diff --git a/arch/nds32/include/asm/highmem.h b/arch/nds32/include/asm/highmem.h
index c93c7368bb3f..a3970e566ede 100644
--- a/arch/nds32/include/asm/highmem.h
+++ b/arch/nds32/include/asm/highmem.h
@@ -51,7 +51,6 @@ extern void kmap_init(void);
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic(struct page *page);
 extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
 extern struct page *kmap_atomic_to_page(void *ptr);
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index f9348bec0ecb..f5f3a21460c4 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -10,18 +10,13 @@
 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 
-void *kmap_atomic(struct page *page)
+void *kmap_atomic_high(struct page *page)
 {
 	unsigned int idx;
 	unsigned long vaddr, pte;
 	int type;
 	pte_t *ptep;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
 	type = kmap_atomic_idx_push();
 
 	idx = type + KM_TYPE_NR * smp_processor_id();
@@ -37,7 +32,7 @@ void *kmap_atomic(struct page *page)
 	return (void *)vaddr;
 }
 
-EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_high);
 
 void __kunmap_atomic(void *kvaddr)
 {
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index d049806a8354..74fa2c726fde 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -71,9 +71,9 @@ static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 }
 extern void __kunmap_atomic(void *kvaddr);
 
-static inline void *kmap_atomic(struct page *page)
+static inline void *kmap_atomic_high(struct page *page)
 {
-	return kmap_atomic_prot(page, kmap_prot);
+	return kmap_atomic_high_prot(page, kmap_prot);
 }
 
 
diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c
index f075cef6d663..67aaa5217f7f 100644
--- a/arch/powerpc/mm/highmem.c
+++ b/arch/powerpc/mm/highmem.c
@@ -24,12 +24,6 @@
 #include <linux/highmem.h>
 #include <linux/module.h>
 
-/*
- * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
- * gives a more generic (and caching) interface. But kmap_atomic can
- * be used in IRQ contexts, so in some (very limited) cases we need
- * it.
- */
 void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	unsigned long vaddr;
diff --git a/arch/sparc/include/asm/highmem.h b/arch/sparc/include/asm/highmem.h
index 4bdb79fed02c..458210c5bc38 100644
--- a/arch/sparc/include/asm/highmem.h
+++ b/arch/sparc/include/asm/highmem.h
@@ -50,7 +50,6 @@ void kmap_init(void) __init;
 
 #define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
 
-void *kmap_atomic(struct page *page);
 void __kunmap_atomic(void *kvaddr);
 
 #define flush_cache_kmaps()	flush_cache_all()
diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c
index d4a80adea7e5..b53070ab6a31 100644
--- a/arch/sparc/mm/highmem.c
+++ b/arch/sparc/mm/highmem.c
@@ -53,16 +53,11 @@ void __init kmap_init(void)
         kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
 }
 
-void *kmap_atomic(struct page *page)
+void *kmap_atomic_high(struct page *page)
 {
 	unsigned long vaddr;
 	long idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
@@ -87,7 +82,7 @@ void *kmap_atomic(struct page *page)
 
 	return (void*) vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_high);
 
 void __kunmap_atomic(void *kvaddr)
 {
diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index 61f47fef40e5..9393d55a2adb 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -68,7 +68,10 @@ static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 
 	return kmap_atomic_high_prot(page, prot);
 }
-void *kmap_atomic(struct page *page);
+static inline void *kmap_atomic_high(struct page *page)
+{
+	return kmap_atomic_high_prot(page, kmap_prot);
+}
 void __kunmap_atomic(void *kvaddr);
 void *kmap_atomic_pfn(unsigned long pfn);
 void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 48b56b1af902..c3e272a759e0 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -4,14 +4,6 @@
 #include <linux/swap.h> /* for totalram_pages */
 #include <linux/memblock.h>
 
-/*
- * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
- * no global lock is needed and because the kmap code must perform a global TLB
- * invalidation when the kmap pool wraps.
- *
- * However when holding an atomic kmap it is not legal to sleep, so atomic
- * kmaps are appropriate for short, tight code paths only.
- */
 void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	unsigned long vaddr;
@@ -28,12 +20,6 @@ void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 }
 EXPORT_SYMBOL(kmap_atomic_high_prot);
 
-void *kmap_atomic(struct page *page)
-{
-	return kmap_atomic_prot(page, kmap_prot);
-}
-EXPORT_SYMBOL(kmap_atomic);
-
 /*
  * This is the same as kmap_atomic() but can map memory that doesn't
  * have a struct page associated with it.
diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h
index 5a481f7def0b..1e6aa15c4bdf 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -68,7 +68,6 @@ static inline void flush_cache_kmaps(void)
 	flush_cache_all();
 }
 
-void *kmap_atomic(struct page *page);
 void __kunmap_atomic(void *kvaddr);
 
 void kmap_init(void);
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index da734a2ed641..90b85a897cb0 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -37,16 +37,11 @@ static inline enum fixed_addresses kmap_idx(int type, unsigned long color)
 		color;
 }
 
-void *kmap_atomic(struct page *page)
+void *kmap_atomic_high(struct page *page)
 {
 	enum fixed_addresses idx;
 	unsigned long vaddr;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
 	idx = kmap_idx(kmap_atomic_idx_push(),
 		       DCACHE_ALIAS(page_to_phys(page)));
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
@@ -57,7 +52,7 @@ void *kmap_atomic(struct page *page)
 
 	return (void *)vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic);
+EXPORT_SYMBOL(kmap_atomic_high);
 
 void __kunmap_atomic(void *kvaddr)
 {
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index ae6e8cb81043..86b93dee758a 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -32,6 +32,7 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
 #include <asm/kmap_types.h>
 
 #ifdef CONFIG_HIGHMEM
+extern void *kmap_atomic_high(struct page *page);
 #include <asm/highmem.h>
 
 #ifndef ARCH_HAS_KMAP_FLUSH_TLB
@@ -61,6 +62,28 @@ static inline void kunmap(struct page *page)
 	kunmap_high(page);
 }
 
+/*
+ * kmap_atomic/kunmap_atomic is significantly faster than kmap/kunmap because
+ * no global lock is needed and because the kmap code must perform a global TLB
+ * invalidation when the kmap pool wraps.
+ *
+ * However when holding an atomic kmap is is not legal to sleep, so atomic
+ * kmaps are appropriate for short, tight code paths only.
+ *
+ * The use of kmap_atomic/kunmap_atomic is discouraged - kmap/kunmap
+ * gives a more generic (and caching) interface. But kmap_atomic can
+ * be used in IRQ contexts, so in some (very limited) cases we need
+ * it.
+ */
+static inline void *kmap_atomic(struct page *page)
+{
+	preempt_disable();
+	pagefault_disable();
+	if (!PageHighMem(page))
+		return page_address(page);
+	return kmap_atomic_high(page);
+}
+
 /* declarations for linux/mm/highmem.c */
 unsigned int nr_free_highpages(void);
 extern atomic_long_t _totalhigh_pages;
-- 
2.25.1

Re: [PATCH V2 06/11] arch/kmap_atomic: Consolidate duplicate code

[Christoph Hellwig]

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

[PATCH V2 07/11] arch/kunmap_atomic: Consolidate duplicate code

[ira.weiny]

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

Every single architecture (including !CONFIG_HIGHMEM) calls...

	pagefault_enable();
	preempt_enable();

... before returning from __kunmap_atomic().  Lift this code into the
kunmap_atomic() macro.

While we are at it rename __kunmap_atomic() to kunmap_atomic_high() to
be consistent.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from V1:
	Adjust to preserve bisect-ability
	Remove uneeded kunmap_atomic_high() declarations
---
 arch/arc/include/asm/highmem.h        |  2 --
 arch/arc/mm/highmem.c                 |  7 ++-----
 arch/arm/include/asm/highmem.h        |  1 -
 arch/arm/mm/highmem.c                 |  6 ++----
 arch/csky/include/asm/highmem.h       |  1 -
 arch/csky/mm/highmem.c                |  9 +++------
 arch/microblaze/include/asm/highmem.h |  1 -
 arch/microblaze/mm/highmem.c          |  6 ++----
 arch/mips/include/asm/highmem.h       |  1 -
 arch/mips/mm/cache.c                  |  4 ++--
 arch/mips/mm/highmem.c                |  6 ++----
 arch/nds32/include/asm/highmem.h      |  1 -
 arch/nds32/mm/highmem.c               |  6 ++----
 arch/parisc/include/asm/cacheflush.h  |  4 +---
 arch/powerpc/include/asm/highmem.h    |  1 -
 arch/powerpc/mm/highmem.c             |  6 ++----
 arch/sparc/include/asm/highmem.h      |  2 --
 arch/sparc/mm/highmem.c               |  6 ++----
 arch/x86/include/asm/highmem.h        |  1 -
 arch/x86/mm/highmem_32.c              |  7 ++-----
 arch/xtensa/include/asm/highmem.h     |  2 --
 arch/xtensa/mm/highmem.c              |  7 ++-----
 include/linux/highmem.h               | 11 +++++++----
 23 files changed, 31 insertions(+), 67 deletions(-)

diff --git a/arch/arc/include/asm/highmem.h b/arch/arc/include/asm/highmem.h
index db425cd38545..70900a73bfc8 100644
--- a/arch/arc/include/asm/highmem.h
+++ b/arch/arc/include/asm/highmem.h
@@ -30,8 +30,6 @@
 
 #include <asm/cacheflush.h>
 
-extern void __kunmap_atomic(void *kvaddr);
-
 extern void kmap_init(void);
 
 static inline void flush_cache_kmaps(void)
diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index 0964b011c29f..5d3eab4ac0b0 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -65,7 +65,7 @@ void *kmap_atomic_high(struct page *page)
 }
 EXPORT_SYMBOL(kmap_atomic_high);
 
-void __kunmap_atomic(void *kv)
+void kunmap_atomic_high(void *kv)
 {
 	unsigned long kvaddr = (unsigned long)kv;
 
@@ -87,11 +87,8 @@ void __kunmap_atomic(void *kv)
 
 		kmap_atomic_idx_pop();
 	}
-
-	pagefault_enable();
-	preempt_enable();
 }
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
 
 static noinline pte_t * __init alloc_kmap_pgtable(unsigned long kvaddr)
 {
diff --git a/arch/arm/include/asm/highmem.h b/arch/arm/include/asm/highmem.h
index 8c80bfe18a34..b0d4bd8dc3c1 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -60,7 +60,6 @@ static inline void *kmap_high_get(struct page *page)
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
 #endif
 
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index 075fdc235091..ac8394655a6e 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -73,7 +73,7 @@ void *kmap_atomic_high(struct page *page)
 }
 EXPORT_SYMBOL(kmap_atomic_high);
 
-void __kunmap_atomic(void *kvaddr)
+void kunmap_atomic_high(void *kvaddr)
 {
 	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 	int idx, type;
@@ -95,10 +95,8 @@ void __kunmap_atomic(void *kvaddr)
 		/* this address was obtained through kmap_high_get() */
 		kunmap_high(pte_page(pkmap_page_table[PKMAP_NR(vaddr)]));
 	}
-	pagefault_enable();
-	preempt_enable();
 }
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
 
 void *kmap_atomic_pfn(unsigned long pfn)
 {
diff --git a/arch/csky/include/asm/highmem.h b/arch/csky/include/asm/highmem.h
index 8ceee12f9bc1..263fbddcd0a3 100644
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -32,7 +32,6 @@ extern pte_t *pkmap_page_table;
 
 #define ARCH_HAS_KMAP_FLUSH_TLB
 extern void kmap_flush_tlb(unsigned long addr);
-extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
 extern struct page *kmap_atomic_to_page(void *ptr);
 
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 63d74b47eee6..0aafbbbe651c 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -39,13 +39,13 @@ void *kmap_atomic_high(struct page *page)
 }
 EXPORT_SYMBOL(kmap_atomic_high);
 
-void __kunmap_atomic(void *kvaddr)
+void kunmap_atomic_high(void *kvaddr)
 {
 	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 	int idx;
 
 	if (vaddr < FIXADDR_START)
-		goto out;
+		return;
 
 #ifdef CONFIG_DEBUG_HIGHMEM
 	idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
@@ -58,11 +58,8 @@ void __kunmap_atomic(void *kvaddr)
 	(void) idx; /* to kill a warning */
 #endif
 	kmap_atomic_idx_pop();
-out:
-	pagefault_enable();
-	preempt_enable();
 }
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
 
 /*
  * This is the same as kmap_atomic() but can map memory that doesn't
diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
index 00c75a423ac4..1b8a3c5102bd 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -61,7 +61,6 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 
 	return kmap_atomic_high_prot(page, prot);
 }
-extern void __kunmap_atomic(void *kvaddr);
 
 static inline void *kmap_atomic_high(struct page *page)
 {
diff --git a/arch/microblaze/mm/highmem.c b/arch/microblaze/mm/highmem.c
index 0e3efaa8a004..ee8a422b2b76 100644
--- a/arch/microblaze/mm/highmem.c
+++ b/arch/microblaze/mm/highmem.c
@@ -51,7 +51,7 @@ void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 }
 EXPORT_SYMBOL(kmap_atomic_high_prot);
 
-void __kunmap_atomic(void *kvaddr)
+void kunmap_atomic_high(void *kvaddr)
 {
 	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 	int type;
@@ -77,7 +77,5 @@ void __kunmap_atomic(void *kvaddr)
 	local_flush_tlb_page(NULL, vaddr);
 
 	kmap_atomic_idx_pop();
-	pagefault_enable();
-	preempt_enable();
 }
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
diff --git a/arch/mips/include/asm/highmem.h b/arch/mips/include/asm/highmem.h
index 8bdbbfc322ad..76dec0bd4f59 100644
--- a/arch/mips/include/asm/highmem.h
+++ b/arch/mips/include/asm/highmem.h
@@ -48,7 +48,6 @@ extern pte_t *pkmap_page_table;
 
 #define ARCH_HAS_KMAP_FLUSH_TLB
 extern void kmap_flush_tlb(unsigned long addr);
-extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
 
 #define flush_cache_kmaps()	BUG_ON(cpu_has_dc_aliases)
diff --git a/arch/mips/mm/cache.c b/arch/mips/mm/cache.c
index f015bb51fab0..1873c2a01fdb 100644
--- a/arch/mips/mm/cache.c
+++ b/arch/mips/mm/cache.c
@@ -104,7 +104,7 @@ void __flush_dcache_page(struct page *page)
 	flush_data_cache_page(addr);
 
 	if (PageHighMem(page))
-		__kunmap_atomic((void *)addr);
+		kunmap_atomic((void *)addr);
 }
 
 EXPORT_SYMBOL(__flush_dcache_page);
@@ -147,7 +147,7 @@ void __update_cache(unsigned long address, pte_t pte)
 			flush_data_cache_page(addr);
 
 		if (PageHighMem(page))
-			__kunmap_atomic((void *)addr);
+			kunmap_atomic((void *)addr);
 
 		ClearPageDcacheDirty(page);
 	}
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index 2bda56372995..155fbb107b35 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -36,7 +36,7 @@ void *kmap_atomic_high(struct page *page)
 }
 EXPORT_SYMBOL(kmap_atomic_high);
 
-void __kunmap_atomic(void *kvaddr)
+void kunmap_atomic_high(void *kvaddr)
 {
 	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 	int type __maybe_unused;
@@ -63,10 +63,8 @@ void __kunmap_atomic(void *kvaddr)
 	}
 #endif
 	kmap_atomic_idx_pop();
-	pagefault_enable();
-	preempt_enable();
 }
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
 
 /*
  * This is the same as kmap_atomic() but can map memory that doesn't
diff --git a/arch/nds32/include/asm/highmem.h b/arch/nds32/include/asm/highmem.h
index a3970e566ede..4d21308549c9 100644
--- a/arch/nds32/include/asm/highmem.h
+++ b/arch/nds32/include/asm/highmem.h
@@ -51,7 +51,6 @@ extern void kmap_init(void);
  * when CONFIG_HIGHMEM is not set.
  */
 #ifdef CONFIG_HIGHMEM
-extern void __kunmap_atomic(void *kvaddr);
 extern void *kmap_atomic_pfn(unsigned long pfn);
 extern struct page *kmap_atomic_to_page(void *ptr);
 #endif
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index f5f3a21460c4..f6e6915c0d31 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -34,7 +34,7 @@ void *kmap_atomic_high(struct page *page)
 
 EXPORT_SYMBOL(kmap_atomic_high);
 
-void __kunmap_atomic(void *kvaddr)
+void kunmap_atomic_high(void *kvaddr)
 {
 	if (kvaddr >= (void *)FIXADDR_START) {
 		unsigned long vaddr = (unsigned long)kvaddr;
@@ -45,8 +45,6 @@ void __kunmap_atomic(void *kvaddr)
 		ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
 		set_pte(ptep, 0);
 	}
-	pagefault_enable();
-	preempt_enable();
 }
 
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index 0c83644bfa5c..119c9a7681bc 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -122,11 +122,9 @@ static inline void *kmap_atomic(struct page *page)
 	return page_address(page);
 }
 
-static inline void __kunmap_atomic(void *addr)
+static inline void kunmap_atomic_high(void *addr)
 {
 	flush_kernel_dcache_page_addr(addr);
-	pagefault_enable();
-	preempt_enable();
 }
 
 #define kmap_atomic_prot(page, prot)	kmap_atomic(page)
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index 74fa2c726fde..373a470df205 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -69,7 +69,6 @@ static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 
 	return kmap_atomic_high_prot(page, prot);
 }
-extern void __kunmap_atomic(void *kvaddr);
 
 static inline void *kmap_atomic_high(struct page *page)
 {
diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c
index 67aaa5217f7f..35071c2913f1 100644
--- a/arch/powerpc/mm/highmem.c
+++ b/arch/powerpc/mm/highmem.c
@@ -40,7 +40,7 @@ void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 }
 EXPORT_SYMBOL(kmap_atomic_high_prot);
 
-void __kunmap_atomic(void *kvaddr)
+void kunmap_atomic_high(void *kvaddr)
 {
 	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 
@@ -66,7 +66,5 @@ void __kunmap_atomic(void *kvaddr)
 	}
 
 	kmap_atomic_idx_pop();
-	pagefault_enable();
-	preempt_enable();
 }
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
diff --git a/arch/sparc/include/asm/highmem.h b/arch/sparc/include/asm/highmem.h
index 458210c5bc38..f4babe67cb5d 100644
--- a/arch/sparc/include/asm/highmem.h
+++ b/arch/sparc/include/asm/highmem.h
@@ -50,8 +50,6 @@ void kmap_init(void) __init;
 
 #define PKMAP_END (PKMAP_ADDR(LAST_PKMAP))
 
-void __kunmap_atomic(void *kvaddr);
-
 #define flush_cache_kmaps()	flush_cache_all()
 
 #endif /* __KERNEL__ */
diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c
index b53070ab6a31..469786bc430f 100644
--- a/arch/sparc/mm/highmem.c
+++ b/arch/sparc/mm/highmem.c
@@ -84,7 +84,7 @@ void *kmap_atomic_high(struct page *page)
 }
 EXPORT_SYMBOL(kmap_atomic_high);
 
-void __kunmap_atomic(void *kvaddr)
+void kunmap_atomic_high(void *kvaddr)
 {
 	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 	int type;
@@ -126,7 +126,5 @@ void __kunmap_atomic(void *kvaddr)
 #endif
 
 	kmap_atomic_idx_pop();
-	pagefault_enable();
-	preempt_enable();
 }
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index 9393d55a2adb..be66b77885a0 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -72,7 +72,6 @@ static inline void *kmap_atomic_high(struct page *page)
 {
 	return kmap_atomic_high_prot(page, kmap_prot);
 }
-void __kunmap_atomic(void *kvaddr);
 void *kmap_atomic_pfn(unsigned long pfn);
 void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
 
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index c3e272a759e0..075fe51317b0 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -30,7 +30,7 @@ void *kmap_atomic_pfn(unsigned long pfn)
 }
 EXPORT_SYMBOL_GPL(kmap_atomic_pfn);
 
-void __kunmap_atomic(void *kvaddr)
+void kunmap_atomic_high(void *kvaddr)
 {
 	unsigned long vaddr = (unsigned long) kvaddr & PAGE_MASK;
 
@@ -60,11 +60,8 @@ void __kunmap_atomic(void *kvaddr)
 		BUG_ON(vaddr >= (unsigned long)high_memory);
 	}
 #endif
-
-	pagefault_enable();
-	preempt_enable();
 }
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
 
 void __init set_highmem_pages_init(void)
 {
diff --git a/arch/xtensa/include/asm/highmem.h b/arch/xtensa/include/asm/highmem.h
index 1e6aa15c4bdf..d6a10704307a 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -68,8 +68,6 @@ static inline void flush_cache_kmaps(void)
 	flush_cache_all();
 }
 
-void __kunmap_atomic(void *kvaddr);
-
 void kmap_init(void);
 
 #endif
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index 90b85a897cb0..4de323e43682 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -54,7 +54,7 @@ void *kmap_atomic_high(struct page *page)
 }
 EXPORT_SYMBOL(kmap_atomic_high);
 
-void __kunmap_atomic(void *kvaddr)
+void kunmap_atomic_high(void *kvaddr)
 {
 	if (kvaddr >= (void *)FIXADDR_START &&
 	    kvaddr < (void *)FIXADDR_TOP) {
@@ -73,11 +73,8 @@ void __kunmap_atomic(void *kvaddr)
 
 		kmap_atomic_idx_pop();
 	}
-
-	pagefault_enable();
-	preempt_enable();
 }
-EXPORT_SYMBOL(__kunmap_atomic);
+EXPORT_SYMBOL(kunmap_atomic_high);
 
 void __init kmap_init(void)
 {
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 86b93dee758a..c36c0ee09423 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -33,6 +33,7 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
 
 #ifdef CONFIG_HIGHMEM
 extern void *kmap_atomic_high(struct page *page);
+extern void kunmap_atomic_high(void *kvaddr);
 #include <asm/highmem.h>
 
 #ifndef ARCH_HAS_KMAP_FLUSH_TLB
@@ -146,10 +147,10 @@ static inline void *kmap_atomic(struct page *page)
 }
 #define kmap_atomic_prot(page, prot)	kmap_atomic(page)
 
-static inline void __kunmap_atomic(void *addr)
+static inline void kunmap_atomic_high(void *addr)
 {
-	pagefault_enable();
-	preempt_enable();
+	/* Nothing to do in the CONFIG_HIGHMEM=n case as kunmap_atomic()
+	 * handles re-enabling faults + preemption */
 }
 
 #define kmap_atomic_pfn(pfn)	kmap_atomic(pfn_to_page(pfn))
@@ -199,7 +200,9 @@ static inline void kmap_atomic_idx_pop(void)
 #define kunmap_atomic(addr)                                     \
 do {                                                            \
 	BUILD_BUG_ON(__same_type((addr), struct page *));       \
-	__kunmap_atomic(addr);                                  \
+	kunmap_atomic_high(addr);                                  \
+	pagefault_enable();                                     \
+	preempt_enable();                                       \
 } while (0)
 
 
-- 
2.25.1

Re: [PATCH V2 07/11] arch/kunmap_atomic: Consolidate duplicate code

[Christoph Hellwig]

On Sun, May 03, 2020 at 06:09:08PM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> Every single architecture (including !CONFIG_HIGHMEM) calls...
> 
> 	pagefault_enable();
> 	preempt_enable();
> 
> ... before returning from __kunmap_atomic().  Lift this code into the
> kunmap_atomic() macro.
> 
> While we are at it rename __kunmap_atomic() to kunmap_atomic_high() to
> be consistent.
> 
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

[PATCH V2 08/11] arch/kmap: Ensure kmap_prot visibility

[ira.weiny]

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

We want to support kmap_atomic_prot() on all architectures and it makes
sense to define kmap_atomic() to use the default kmap_prot.

So we ensure all arch's have a globally available kmap_prot either as a
define or exported symbol.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/microblaze/include/asm/highmem.h | 2 +-
 arch/microblaze/mm/init.c             | 3 ---
 arch/powerpc/include/asm/highmem.h    | 2 +-
 arch/powerpc/mm/mem.c                 | 3 ---
 arch/sparc/mm/highmem.c               | 1 +
 5 files changed, 3 insertions(+), 8 deletions(-)

diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
index 1b8a3c5102bd..033ac5b5c2da 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -25,8 +25,8 @@
 #include <linux/uaccess.h>
 #include <asm/fixmap.h>
 
+#define kmap_prot		PAGE_KERNEL
 extern pte_t *kmap_pte;
-extern pgprot_t kmap_prot;
 extern pte_t *pkmap_page_table;
 
 /*
diff --git a/arch/microblaze/mm/init.c b/arch/microblaze/mm/init.c
index 1ffbfa96b9b8..a467686c13af 100644
--- a/arch/microblaze/mm/init.c
+++ b/arch/microblaze/mm/init.c
@@ -49,8 +49,6 @@ unsigned long lowmem_size;
 #ifdef CONFIG_HIGHMEM
 pte_t *kmap_pte;
 EXPORT_SYMBOL(kmap_pte);
-pgprot_t kmap_prot;
-EXPORT_SYMBOL(kmap_prot);
 
 static inline pte_t *virt_to_kpte(unsigned long vaddr)
 {
@@ -68,7 +66,6 @@ static void __init highmem_init(void)
 	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 
 	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
-	kmap_prot = PAGE_KERNEL;
 }
 
 static void highmem_setup(void)
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index 373a470df205..ee5de974c5ef 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -29,8 +29,8 @@
 #include <asm/page.h>
 #include <asm/fixmap.h>
 
+#define kmap_prot		PAGE_KERNEL
 extern pte_t *kmap_pte;
-extern pgprot_t kmap_prot;
 extern pte_t *pkmap_page_table;
 
 /*
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 041ed7cfd341..3f642b058731 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -64,8 +64,6 @@ bool init_mem_is_free;
 #ifdef CONFIG_HIGHMEM
 pte_t *kmap_pte;
 EXPORT_SYMBOL(kmap_pte);
-pgprot_t kmap_prot;
-EXPORT_SYMBOL(kmap_prot);
 #endif
 
 pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
@@ -245,7 +243,6 @@ void __init paging_init(void)
 	pkmap_page_table = virt_to_kpte(PKMAP_BASE);
 
 	kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
-	kmap_prot = PAGE_KERNEL;
 #endif /* CONFIG_HIGHMEM */
 
 	printk(KERN_DEBUG "Top of RAM: 0x%llx, Total RAM: 0x%llx\n",
diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c
index 469786bc430f..9f06d75e88e1 100644
--- a/arch/sparc/mm/highmem.c
+++ b/arch/sparc/mm/highmem.c
@@ -33,6 +33,7 @@
 #include <asm/vaddrs.h>
 
 pgprot_t kmap_prot;
+EXPORT_SYMBOL(kmap_prot);
 
 static pte_t *kmap_pte;
 
-- 
2.25.1

Re: [PATCH V2 08/11] arch/kmap: Ensure kmap_prot visibility

[Christoph Hellwig]

On Sun, May 03, 2020 at 06:09:09PM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> We want to support kmap_atomic_prot() on all architectures and it makes
> sense to define kmap_atomic() to use the default kmap_prot.
> 
> So we ensure all arch's have a globally available kmap_prot either as a
> define or exported symbol.

FYI, I still think a

#ifndef kmap_prot
#define kmap_prot PAGE_KERNEL
#endif

in linux/highmem.h would be nicer.  Then only xtensa and sparc need
to override it and clearly stand out.

Re: [PATCH V2 08/11] arch/kmap: Ensure kmap_prot visibility

[Ira Weiny]

On Tue, May 05, 2020 at 11:13:26PM -0700, Christoph Hellwig wrote:
> On Sun, May 03, 2020 at 06:09:09PM -0700, ira.weiny@intel.com wrote:
> > From: Ira Weiny <ira.weiny@intel.com>
> > 
> > We want to support kmap_atomic_prot() on all architectures and it makes
> > sense to define kmap_atomic() to use the default kmap_prot.
> > 
> > So we ensure all arch's have a globally available kmap_prot either as a
> > define or exported symbol.
> 
> FYI, I still think a
> 
> #ifndef kmap_prot
> #define kmap_prot PAGE_KERNEL
> #endif
> 
> in linux/highmem.h would be nicer.  Then only xtensa and sparc need
> to override it and clearly stand out.

That would be nice...  But...  in this particular patch kmap_prot needs to be
in arch/microblaze/include/asm/highmem.h to preserve bisect-ability.

So there would be an inversion with this define and the core #ifndef...

I like the change but I'm going to add this change as a follow on patch because
at the end of the series microblaze no longer needs this.

If this is reasonable could I get a review on this patch to add to the next
series?

Ira

Re: [PATCH V2 08/11] arch/kmap: Ensure kmap_prot visibility

[Christoph Hellwig]

On Sun, May 03, 2020 at 06:09:09PM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> We want to support kmap_atomic_prot() on all architectures and it makes
> sense to define kmap_atomic() to use the default kmap_prot.
> 
> So we ensure all arch's have a globally available kmap_prot either as a
> define or exported symbol.
> 
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

[PATCH V2 09/11] arch/kmap: Don't hard code kmap_prot values

[ira.weiny]

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

To support kmap_atomic_prot() on all architectures each arch must
support protections passed in to them.

Change csky, mips, nds32 and xtensa to use their global constant
kmap_prot rather than a hard coded value which was equal.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
changes from V1:
	Mention that kmap_prot is a constant in commit message
---
 arch/csky/mm/highmem.c   | 2 +-
 arch/mips/mm/highmem.c   | 2 +-
 arch/nds32/mm/highmem.c  | 2 +-
 arch/xtensa/mm/highmem.c | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 0aafbbbe651c..f4311669b5bb 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -32,7 +32,7 @@ void *kmap_atomic_high(struct page *page)
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(kmap_pte - idx)));
 #endif
-	set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
+	set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
 	flush_tlb_one((unsigned long)vaddr);
 
 	return (void *)vaddr;
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index 155fbb107b35..87023bd1a33c 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -29,7 +29,7 @@ void *kmap_atomic_high(struct page *page)
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(kmap_pte - idx)));
 #endif
-	set_pte(kmap_pte-idx, mk_pte(page, PAGE_KERNEL));
+	set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
 	local_flush_tlb_one((unsigned long)vaddr);
 
 	return (void*) vaddr;
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index f6e6915c0d31..809f8c830f06 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -21,7 +21,7 @@ void *kmap_atomic_high(struct page *page)
 
 	idx = type + KM_TYPE_NR * smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-	pte = (page_to_pfn(page) << PAGE_SHIFT) | (PAGE_KERNEL);
+	pte = (page_to_pfn(page) << PAGE_SHIFT) | (kmap_prot);
 	ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
 	set_pte(ptep, pte);
 
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index 4de323e43682..50168b09510a 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -48,7 +48,7 @@ void *kmap_atomic_high(struct page *page)
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(kmap_pte + idx)));
 #endif
-	set_pte(kmap_pte + idx, mk_pte(page, PAGE_KERNEL_EXEC));
+	set_pte(kmap_pte + idx, mk_pte(page, kmap_prot));
 
 	return (void *)vaddr;
 }
-- 
2.25.1

[PATCH V2 10/11] arch/kmap: Define kmap_atomic_prot() for all arch's

[ira.weiny]

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

To support kmap_atomic_prot(), all architectures need to support
protections passed to their kmap_atomic_high() function.  Pass
protections into kmap_atomic_high() and change the name to
kmap_atomic_high_prot() to match.

Then define kmap_atomic_prot() as a core function which calls
kmap_atomic_high_prot() when needed.

Finally, redefine kmap_atomic() as a wrapper of kmap_atomic_prot() with
the default kmap_prot exported by the architectures.

Signed-off-by: Ira Weiny <ira.weiny@intel.com>

---
Changes from V1:
	Adjust for bisect-ability
	Adjust for removing kunmap_atomic_high
	Remove kmap_atomic_high_prot declarations
---
 arch/arc/mm/highmem.c                 |  6 +++---
 arch/arm/mm/highmem.c                 |  6 +++---
 arch/csky/mm/highmem.c                |  6 +++---
 arch/microblaze/include/asm/highmem.h | 16 ----------------
 arch/mips/mm/highmem.c                |  6 +++---
 arch/nds32/mm/highmem.c               |  6 +++---
 arch/powerpc/include/asm/highmem.h    | 17 -----------------
 arch/sparc/mm/highmem.c               |  6 +++---
 arch/x86/include/asm/highmem.h        | 14 --------------
 arch/xtensa/mm/highmem.c              |  6 +++---
 include/linux/highmem.h               |  7 ++++---
 11 files changed, 25 insertions(+), 71 deletions(-)

diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index 5d3eab4ac0b0..479b0d72d3cf 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -49,7 +49,7 @@
 extern pte_t * pkmap_page_table;
 static pte_t * fixmap_page_table;
 
-void *kmap_atomic_high(struct page *page)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	int idx, cpu_idx;
 	unsigned long vaddr;
@@ -59,11 +59,11 @@ void *kmap_atomic_high(struct page *page)
 	vaddr = FIXMAP_ADDR(idx);
 
 	set_pte_at(&init_mm, vaddr, fixmap_page_table + idx,
-		   mk_pte(page, kmap_prot));
+		   mk_pte(page, prot));
 
 	return (void *)vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic_high);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void kunmap_atomic_high(void *kv)
 {
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index ac8394655a6e..e013f6b81328 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -31,7 +31,7 @@ static inline pte_t get_fixmap_pte(unsigned long vaddr)
 	return *ptep;
 }
 
-void *kmap_atomic_high(struct page *page)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	unsigned int idx;
 	unsigned long vaddr;
@@ -67,11 +67,11 @@ void *kmap_atomic_high(struct page *page)
 	 * in place, so the contained TLB flush ensures the TLB is updated
 	 * with the new mapping.
 	 */
-	set_fixmap_pte(idx, mk_pte(page, kmap_prot));
+	set_fixmap_pte(idx, mk_pte(page, prot));
 
 	return (void *)vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic_high);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void kunmap_atomic_high(void *kvaddr)
 {
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index f4311669b5bb..3ae5c8cd7619 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -21,7 +21,7 @@ EXPORT_SYMBOL(kmap_flush_tlb);
 
 EXPORT_SYMBOL(kmap);
 
-void *kmap_atomic_high(struct page *page)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	unsigned long vaddr;
 	int idx, type;
@@ -32,12 +32,12 @@ void *kmap_atomic_high(struct page *page)
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(kmap_pte - idx)));
 #endif
-	set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
+	set_pte(kmap_pte-idx, mk_pte(page, prot));
 	flush_tlb_one((unsigned long)vaddr);
 
 	return (void *)vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic_high);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void kunmap_atomic_high(void *kvaddr)
 {
diff --git a/arch/microblaze/include/asm/highmem.h b/arch/microblaze/include/asm/highmem.h
index 033ac5b5c2da..d7c55cfd27bd 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -51,22 +51,6 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-void *kmap_atomic_prot(struct page *page, pgprot_t prot)
-{
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
-	return kmap_atomic_high_prot(page, prot);
-}
-
-static inline void *kmap_atomic_high(struct page *page)
-{
-	return kmap_atomic_high_prot(page, kmap_prot);
-}
-
 #define flush_cache_kmaps()	{ flush_icache(); flush_dcache(); }
 
 #endif /* __KERNEL__ */
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index 87023bd1a33c..37e244cdb14e 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -18,7 +18,7 @@ void kmap_flush_tlb(unsigned long addr)
 }
 EXPORT_SYMBOL(kmap_flush_tlb);
 
-void *kmap_atomic_high(struct page *page)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	unsigned long vaddr;
 	int idx, type;
@@ -29,12 +29,12 @@ void *kmap_atomic_high(struct page *page)
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(kmap_pte - idx)));
 #endif
-	set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
+	set_pte(kmap_pte-idx, mk_pte(page, prot));
 	local_flush_tlb_one((unsigned long)vaddr);
 
 	return (void*) vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic_high);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void kunmap_atomic_high(void *kvaddr)
 {
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index 809f8c830f06..63ded527c1e8 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -10,7 +10,7 @@
 #include <asm/fixmap.h>
 #include <asm/tlbflush.h>
 
-void *kmap_atomic_high(struct page *page)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	unsigned int idx;
 	unsigned long vaddr, pte;
@@ -21,7 +21,7 @@ void *kmap_atomic_high(struct page *page)
 
 	idx = type + KM_TYPE_NR * smp_processor_id();
 	vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx);
-	pte = (page_to_pfn(page) << PAGE_SHIFT) | (kmap_prot);
+	pte = (page_to_pfn(page) << PAGE_SHIFT) | prot;
 	ptep = pte_offset_kernel(pmd_off_k(vaddr), vaddr);
 	set_pte(ptep, pte);
 
@@ -32,7 +32,7 @@ void *kmap_atomic_high(struct page *page)
 	return (void *)vaddr;
 }
 
-EXPORT_SYMBOL(kmap_atomic_high);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void kunmap_atomic_high(void *kvaddr)
 {
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h
index ee5de974c5ef..8d8ee3fcd800 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -59,23 +59,6 @@ extern pte_t *pkmap_page_table;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
-{
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
-	return kmap_atomic_high_prot(page, prot);
-}
-
-static inline void *kmap_atomic_high(struct page *page)
-{
-	return kmap_atomic_high_prot(page, kmap_prot);
-}
-
-
 #define flush_cache_kmaps()	flush_cache_all()
 
 #endif /* __KERNEL__ */
diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c
index 9f06d75e88e1..414f578d1e57 100644
--- a/arch/sparc/mm/highmem.c
+++ b/arch/sparc/mm/highmem.c
@@ -54,7 +54,7 @@ void __init kmap_init(void)
         kmap_prot = __pgprot(SRMMU_ET_PTE | SRMMU_PRIV | SRMMU_CACHE);
 }
 
-void *kmap_atomic_high(struct page *page)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	unsigned long vaddr;
 	long idx, type;
@@ -73,7 +73,7 @@ void *kmap_atomic_high(struct page *page)
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(kmap_pte-idx)));
 #endif
-	set_pte(kmap_pte-idx, mk_pte(page, kmap_prot));
+	set_pte(kmap_pte-idx, mk_pte(page, prot));
 /* XXX Fix - Anton */
 #if 0
 	__flush_tlb_one(vaddr);
@@ -83,7 +83,7 @@ void *kmap_atomic_high(struct page *page)
 
 	return (void*) vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic_high);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void kunmap_atomic_high(void *kvaddr)
 {
diff --git a/arch/x86/include/asm/highmem.h b/arch/x86/include/asm/highmem.h
index be66b77885a0..0f420b24e0fc 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -58,20 +58,6 @@ extern unsigned long highstart_pfn, highend_pfn;
 #define PKMAP_NR(virt)  ((virt-PKMAP_BASE) >> PAGE_SHIFT)
 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 
-extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
-static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
-{
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
-	return kmap_atomic_high_prot(page, prot);
-}
-static inline void *kmap_atomic_high(struct page *page)
-{
-	return kmap_atomic_high_prot(page, kmap_prot);
-}
 void *kmap_atomic_pfn(unsigned long pfn);
 void *kmap_atomic_prot_pfn(unsigned long pfn, pgprot_t prot);
 
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index 50168b09510a..99b5ad137ab5 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -37,7 +37,7 @@ static inline enum fixed_addresses kmap_idx(int type, unsigned long color)
 		color;
 }
 
-void *kmap_atomic_high(struct page *page)
+void *kmap_atomic_high_prot(struct page *page, pgprot_t prot)
 {
 	enum fixed_addresses idx;
 	unsigned long vaddr;
@@ -48,11 +48,11 @@ void *kmap_atomic_high(struct page *page)
 #ifdef CONFIG_DEBUG_HIGHMEM
 	BUG_ON(!pte_none(*(kmap_pte + idx)));
 #endif
-	set_pte(kmap_pte + idx, mk_pte(page, kmap_prot));
+	set_pte(kmap_pte + idx, mk_pte(page, prot));
 
 	return (void *)vaddr;
 }
-EXPORT_SYMBOL(kmap_atomic_high);
+EXPORT_SYMBOL(kmap_atomic_high_prot);
 
 void kunmap_atomic_high(void *kvaddr)
 {
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index c36c0ee09423..89838306f50d 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -32,7 +32,7 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
 #include <asm/kmap_types.h>
 
 #ifdef CONFIG_HIGHMEM
-extern void *kmap_atomic_high(struct page *page);
+extern void *kmap_atomic_high_prot(struct page *page, pgprot_t prot);
 extern void kunmap_atomic_high(void *kvaddr);
 #include <asm/highmem.h>
 
@@ -76,14 +76,15 @@ static inline void kunmap(struct page *page)
  * be used in IRQ contexts, so in some (very limited) cases we need
  * it.
  */
-static inline void *kmap_atomic(struct page *page)
+static inline void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 {
 	preempt_disable();
 	pagefault_disable();
 	if (!PageHighMem(page))
 		return page_address(page);
-	return kmap_atomic_high(page);
+	return kmap_atomic_high_prot(page, prot);
 }
+#define kmap_atomic(page)	kmap_atomic_prot(page, kmap_prot)
 
 /* declarations for linux/mm/highmem.c */
 unsigned int nr_free_highpages(void);
-- 
2.25.1

Re: [PATCH V2 10/11] arch/kmap: Define kmap_atomic_prot() for all arch's

[Christoph Hellwig]

On Sun, May 03, 2020 at 06:09:11PM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> To support kmap_atomic_prot(), all architectures need to support
> protections passed to their kmap_atomic_high() function.  Pass
> protections into kmap_atomic_high() and change the name to
> kmap_atomic_high_prot() to match.
> 
> Then define kmap_atomic_prot() as a core function which calls
> kmap_atomic_high_prot() when needed.
> 
> Finally, redefine kmap_atomic() as a wrapper of kmap_atomic_prot() with
> the default kmap_prot exported by the architectures.
> 
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

Looks good,

Reviewed-by: Christoph Hellwig <hch@lst.de>

[PATCH V2 11/11] drm: Remove drm specific kmap_atomic code

[ira.weiny]

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

kmap_atomic_prot() is now exported by all architectures.  Use this
function rather than open coding a driver specific kmap_atomic.

Reviewed-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 drivers/gpu/drm/ttm/ttm_bo_util.c    | 56 ++--------------------------
 drivers/gpu/drm/vmwgfx/vmwgfx_blit.c | 16 ++++----
 include/drm/ttm/ttm_bo_api.h         |  4 --
 3 files changed, 12 insertions(+), 64 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
index 52d2b71f1588..f09b096ba4fd 100644
--- a/drivers/gpu/drm/ttm/ttm_bo_util.c
+++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
@@ -257,54 +257,6 @@ static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
 	return 0;
 }
 
-#ifdef CONFIG_X86
-#define __ttm_kmap_atomic_prot(__page, __prot) kmap_atomic_prot(__page, __prot)
-#define __ttm_kunmap_atomic(__addr) kunmap_atomic(__addr)
-#else
-#define __ttm_kmap_atomic_prot(__page, __prot) vmap(&__page, 1, 0,  __prot)
-#define __ttm_kunmap_atomic(__addr) vunmap(__addr)
-#endif
-
-
-/**
- * ttm_kmap_atomic_prot - Efficient kernel map of a single page with
- * specified page protection.
- *
- * @page: The page to map.
- * @prot: The page protection.
- *
- * This function maps a TTM page using the kmap_atomic api if available,
- * otherwise falls back to vmap. The user must make sure that the
- * specified page does not have an aliased mapping with a different caching
- * policy unless the architecture explicitly allows it. Also mapping and
- * unmapping using this api must be correctly nested. Unmapping should
- * occur in the reverse order of mapping.
- */
-void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot)
-{
-	if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
-		return kmap_atomic(page);
-	else
-		return __ttm_kmap_atomic_prot(page, prot);
-}
-EXPORT_SYMBOL(ttm_kmap_atomic_prot);
-
-/**
- * ttm_kunmap_atomic_prot - Unmap a page that was mapped using
- * ttm_kmap_atomic_prot.
- *
- * @addr: The virtual address from the map.
- * @prot: The page protection.
- */
-void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot)
-{
-	if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
-		kunmap_atomic(addr);
-	else
-		__ttm_kunmap_atomic(addr);
-}
-EXPORT_SYMBOL(ttm_kunmap_atomic_prot);
-
 static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
 				unsigned long page,
 				pgprot_t prot)
@@ -316,13 +268,13 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
 		return -ENOMEM;
 
 	src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
-	dst = ttm_kmap_atomic_prot(d, prot);
+	dst = kmap_atomic_prot(d, prot);
 	if (!dst)
 		return -ENOMEM;
 
 	memcpy_fromio(dst, src, PAGE_SIZE);
 
-	ttm_kunmap_atomic_prot(dst, prot);
+	kunmap_atomic(dst);
 
 	return 0;
 }
@@ -338,13 +290,13 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
 		return -ENOMEM;
 
 	dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
-	src = ttm_kmap_atomic_prot(s, prot);
+	src = kmap_atomic_prot(s, prot);
 	if (!src)
 		return -ENOMEM;
 
 	memcpy_toio(dst, src, PAGE_SIZE);
 
-	ttm_kunmap_atomic_prot(src, prot);
+	kunmap_atomic(src);
 
 	return 0;
 }
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
index bb46ca0c458f..94d456a1d1a9 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
@@ -374,12 +374,12 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
 		copy_size = min_t(u32, copy_size, PAGE_SIZE - src_page_offset);
 
 		if (unmap_src) {
-			ttm_kunmap_atomic_prot(d->src_addr, d->src_prot);
+			kunmap_atomic(d->src_addr);
 			d->src_addr = NULL;
 		}
 
 		if (unmap_dst) {
-			ttm_kunmap_atomic_prot(d->dst_addr, d->dst_prot);
+			kunmap_atomic(d->dst_addr);
 			d->dst_addr = NULL;
 		}
 
@@ -388,8 +388,8 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
 				return -EINVAL;
 
 			d->dst_addr =
-				ttm_kmap_atomic_prot(d->dst_pages[dst_page],
-						     d->dst_prot);
+				kmap_atomic_prot(d->dst_pages[dst_page],
+						 d->dst_prot);
 			if (!d->dst_addr)
 				return -ENOMEM;
 
@@ -401,8 +401,8 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
 				return -EINVAL;
 
 			d->src_addr =
-				ttm_kmap_atomic_prot(d->src_pages[src_page],
-						     d->src_prot);
+				kmap_atomic_prot(d->src_pages[src_page],
+						 d->src_prot);
 			if (!d->src_addr)
 				return -ENOMEM;
 
@@ -499,9 +499,9 @@ int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
 	}
 out:
 	if (d.src_addr)
-		ttm_kunmap_atomic_prot(d.src_addr, d.src_prot);
+		kunmap_atomic(d.src_addr);
 	if (d.dst_addr)
-		ttm_kunmap_atomic_prot(d.dst_addr, d.dst_prot);
+		kunmap_atomic(d.dst_addr);
 
 	return ret;
 }
diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
index 0a9d042e075a..de1ccdcd5703 100644
--- a/include/drm/ttm/ttm_bo_api.h
+++ b/include/drm/ttm/ttm_bo_api.h
@@ -668,10 +668,6 @@ int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
 int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
 		struct ttm_bo_device *bdev);
 
-void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot);
-
-void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot);
-
 /**
  * ttm_bo_io
  *
-- 
2.25.1

Re: [PATCH V2 11/11] drm: Remove drm specific kmap_atomic code

[Daniel Vetter]

On Mon, May 4, 2020 at 3:09 AM <ira.weiny@intel.com> wrote:
>
> From: Ira Weiny <ira.weiny@intel.com>
>
> kmap_atomic_prot() is now exported by all architectures.  Use this
> function rather than open coding a driver specific kmap_atomic.
>
> Reviewed-by: Christian König <christian.koenig@amd.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> Signed-off-by: Ira Weiny <ira.weiny@intel.com>

I'm assuming this lands through some other tree or a topic branch or whatever.

Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>

Cheers, Daniel

> ---
>  drivers/gpu/drm/ttm/ttm_bo_util.c    | 56 ++--------------------------
>  drivers/gpu/drm/vmwgfx/vmwgfx_blit.c | 16 ++++----
>  include/drm/ttm/ttm_bo_api.h         |  4 --
>  3 files changed, 12 insertions(+), 64 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
> index 52d2b71f1588..f09b096ba4fd 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
> @@ -257,54 +257,6 @@ static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
>         return 0;
>  }
>
> -#ifdef CONFIG_X86
> -#define __ttm_kmap_atomic_prot(__page, __prot) kmap_atomic_prot(__page, __prot)
> -#define __ttm_kunmap_atomic(__addr) kunmap_atomic(__addr)
> -#else
> -#define __ttm_kmap_atomic_prot(__page, __prot) vmap(&__page, 1, 0,  __prot)
> -#define __ttm_kunmap_atomic(__addr) vunmap(__addr)
> -#endif
> -
> -
> -/**
> - * ttm_kmap_atomic_prot - Efficient kernel map of a single page with
> - * specified page protection.
> - *
> - * @page: The page to map.
> - * @prot: The page protection.
> - *
> - * This function maps a TTM page using the kmap_atomic api if available,
> - * otherwise falls back to vmap. The user must make sure that the
> - * specified page does not have an aliased mapping with a different caching
> - * policy unless the architecture explicitly allows it. Also mapping and
> - * unmapping using this api must be correctly nested. Unmapping should
> - * occur in the reverse order of mapping.
> - */
> -void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot)
> -{
> -       if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
> -               return kmap_atomic(page);
> -       else
> -               return __ttm_kmap_atomic_prot(page, prot);
> -}
> -EXPORT_SYMBOL(ttm_kmap_atomic_prot);
> -
> -/**
> - * ttm_kunmap_atomic_prot - Unmap a page that was mapped using
> - * ttm_kmap_atomic_prot.
> - *
> - * @addr: The virtual address from the map.
> - * @prot: The page protection.
> - */
> -void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot)
> -{
> -       if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
> -               kunmap_atomic(addr);
> -       else
> -               __ttm_kunmap_atomic(addr);
> -}
> -EXPORT_SYMBOL(ttm_kunmap_atomic_prot);
> -
>  static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
>                                 unsigned long page,
>                                 pgprot_t prot)
> @@ -316,13 +268,13 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
>                 return -ENOMEM;
>
>         src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
> -       dst = ttm_kmap_atomic_prot(d, prot);
> +       dst = kmap_atomic_prot(d, prot);
>         if (!dst)
>                 return -ENOMEM;
>
>         memcpy_fromio(dst, src, PAGE_SIZE);
>
> -       ttm_kunmap_atomic_prot(dst, prot);
> +       kunmap_atomic(dst);
>
>         return 0;
>  }
> @@ -338,13 +290,13 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
>                 return -ENOMEM;
>
>         dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
> -       src = ttm_kmap_atomic_prot(s, prot);
> +       src = kmap_atomic_prot(s, prot);
>         if (!src)
>                 return -ENOMEM;
>
>         memcpy_toio(dst, src, PAGE_SIZE);
>
> -       ttm_kunmap_atomic_prot(src, prot);
> +       kunmap_atomic(src);
>
>         return 0;
>  }
> diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
> index bb46ca0c458f..94d456a1d1a9 100644
> --- a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
> +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
> @@ -374,12 +374,12 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
>                 copy_size = min_t(u32, copy_size, PAGE_SIZE - src_page_offset);
>
>                 if (unmap_src) {
> -                       ttm_kunmap_atomic_prot(d->src_addr, d->src_prot);
> +                       kunmap_atomic(d->src_addr);
>                         d->src_addr = NULL;
>                 }
>
>                 if (unmap_dst) {
> -                       ttm_kunmap_atomic_prot(d->dst_addr, d->dst_prot);
> +                       kunmap_atomic(d->dst_addr);
>                         d->dst_addr = NULL;
>                 }
>
> @@ -388,8 +388,8 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
>                                 return -EINVAL;
>
>                         d->dst_addr =
> -                               ttm_kmap_atomic_prot(d->dst_pages[dst_page],
> -                                                    d->dst_prot);
> +                               kmap_atomic_prot(d->dst_pages[dst_page],
> +                                                d->dst_prot);
>                         if (!d->dst_addr)
>                                 return -ENOMEM;
>
> @@ -401,8 +401,8 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
>                                 return -EINVAL;
>
>                         d->src_addr =
> -                               ttm_kmap_atomic_prot(d->src_pages[src_page],
> -                                                    d->src_prot);
> +                               kmap_atomic_prot(d->src_pages[src_page],
> +                                                d->src_prot);
>                         if (!d->src_addr)
>                                 return -ENOMEM;
>
> @@ -499,9 +499,9 @@ int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
>         }
>  out:
>         if (d.src_addr)
> -               ttm_kunmap_atomic_prot(d.src_addr, d.src_prot);
> +               kunmap_atomic(d.src_addr);
>         if (d.dst_addr)
> -               ttm_kunmap_atomic_prot(d.dst_addr, d.dst_prot);
> +               kunmap_atomic(d.dst_addr);
>
>         return ret;
>  }
> diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
> index 0a9d042e075a..de1ccdcd5703 100644
> --- a/include/drm/ttm/ttm_bo_api.h
> +++ b/include/drm/ttm/ttm_bo_api.h
> @@ -668,10 +668,6 @@ int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
>  int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
>                 struct ttm_bo_device *bdev);
>
> -void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot);
> -
> -void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot);
> -
>  /**
>   * ttm_bo_io
>   *
> --
> 2.25.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/dri-devel



-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [PATCH V2 11/11] drm: Remove drm specific kmap_atomic code

[Ira Weiny]

On Mon, May 04, 2020 at 01:18:51PM +0200, Daniel Vetter wrote:
> On Mon, May 4, 2020 at 3:09 AM <ira.weiny@intel.com> wrote:
> >
> > From: Ira Weiny <ira.weiny@intel.com>
> >
> > kmap_atomic_prot() is now exported by all architectures.  Use this
> > function rather than open coding a driver specific kmap_atomic.
> >
> > Reviewed-by: Christian König <christian.koenig@amd.com>
> > Reviewed-by: Christoph Hellwig <hch@lst.de>
> > Signed-off-by: Ira Weiny <ira.weiny@intel.com>
> 
> I'm assuming this lands through some other tree or a topic branch or whatever.

Yes I think Andrew queued this up before and so I hope he will continue to do
so with the subsequent versions.

Andrew, LMK if this is an issue.

Thanks,
Ira

> 
> Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
> 
> Cheers, Daniel
> 
> > ---
> >  drivers/gpu/drm/ttm/ttm_bo_util.c    | 56 ++--------------------------
> >  drivers/gpu/drm/vmwgfx/vmwgfx_blit.c | 16 ++++----
> >  include/drm/ttm/ttm_bo_api.h         |  4 --
> >  3 files changed, 12 insertions(+), 64 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/ttm/ttm_bo_util.c b/drivers/gpu/drm/ttm/ttm_bo_util.c
> > index 52d2b71f1588..f09b096ba4fd 100644
> > --- a/drivers/gpu/drm/ttm/ttm_bo_util.c
> > +++ b/drivers/gpu/drm/ttm/ttm_bo_util.c
> > @@ -257,54 +257,6 @@ static int ttm_copy_io_page(void *dst, void *src, unsigned long page)
> >         return 0;
> >  }
> >
> > -#ifdef CONFIG_X86
> > -#define __ttm_kmap_atomic_prot(__page, __prot) kmap_atomic_prot(__page, __prot)
> > -#define __ttm_kunmap_atomic(__addr) kunmap_atomic(__addr)
> > -#else
> > -#define __ttm_kmap_atomic_prot(__page, __prot) vmap(&__page, 1, 0,  __prot)
> > -#define __ttm_kunmap_atomic(__addr) vunmap(__addr)
> > -#endif
> > -
> > -
> > -/**
> > - * ttm_kmap_atomic_prot - Efficient kernel map of a single page with
> > - * specified page protection.
> > - *
> > - * @page: The page to map.
> > - * @prot: The page protection.
> > - *
> > - * This function maps a TTM page using the kmap_atomic api if available,
> > - * otherwise falls back to vmap. The user must make sure that the
> > - * specified page does not have an aliased mapping with a different caching
> > - * policy unless the architecture explicitly allows it. Also mapping and
> > - * unmapping using this api must be correctly nested. Unmapping should
> > - * occur in the reverse order of mapping.
> > - */
> > -void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot)
> > -{
> > -       if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
> > -               return kmap_atomic(page);
> > -       else
> > -               return __ttm_kmap_atomic_prot(page, prot);
> > -}
> > -EXPORT_SYMBOL(ttm_kmap_atomic_prot);
> > -
> > -/**
> > - * ttm_kunmap_atomic_prot - Unmap a page that was mapped using
> > - * ttm_kmap_atomic_prot.
> > - *
> > - * @addr: The virtual address from the map.
> > - * @prot: The page protection.
> > - */
> > -void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot)
> > -{
> > -       if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL))
> > -               kunmap_atomic(addr);
> > -       else
> > -               __ttm_kunmap_atomic(addr);
> > -}
> > -EXPORT_SYMBOL(ttm_kunmap_atomic_prot);
> > -
> >  static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
> >                                 unsigned long page,
> >                                 pgprot_t prot)
> > @@ -316,13 +268,13 @@ static int ttm_copy_io_ttm_page(struct ttm_tt *ttm, void *src,
> >                 return -ENOMEM;
> >
> >         src = (void *)((unsigned long)src + (page << PAGE_SHIFT));
> > -       dst = ttm_kmap_atomic_prot(d, prot);
> > +       dst = kmap_atomic_prot(d, prot);
> >         if (!dst)
> >                 return -ENOMEM;
> >
> >         memcpy_fromio(dst, src, PAGE_SIZE);
> >
> > -       ttm_kunmap_atomic_prot(dst, prot);
> > +       kunmap_atomic(dst);
> >
> >         return 0;
> >  }
> > @@ -338,13 +290,13 @@ static int ttm_copy_ttm_io_page(struct ttm_tt *ttm, void *dst,
> >                 return -ENOMEM;
> >
> >         dst = (void *)((unsigned long)dst + (page << PAGE_SHIFT));
> > -       src = ttm_kmap_atomic_prot(s, prot);
> > +       src = kmap_atomic_prot(s, prot);
> >         if (!src)
> >                 return -ENOMEM;
> >
> >         memcpy_toio(dst, src, PAGE_SIZE);
> >
> > -       ttm_kunmap_atomic_prot(src, prot);
> > +       kunmap_atomic(src);
> >
> >         return 0;
> >  }
> > diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
> > index bb46ca0c458f..94d456a1d1a9 100644
> > --- a/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
> > +++ b/drivers/gpu/drm/vmwgfx/vmwgfx_blit.c
> > @@ -374,12 +374,12 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
> >                 copy_size = min_t(u32, copy_size, PAGE_SIZE - src_page_offset);
> >
> >                 if (unmap_src) {
> > -                       ttm_kunmap_atomic_prot(d->src_addr, d->src_prot);
> > +                       kunmap_atomic(d->src_addr);
> >                         d->src_addr = NULL;
> >                 }
> >
> >                 if (unmap_dst) {
> > -                       ttm_kunmap_atomic_prot(d->dst_addr, d->dst_prot);
> > +                       kunmap_atomic(d->dst_addr);
> >                         d->dst_addr = NULL;
> >                 }
> >
> > @@ -388,8 +388,8 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
> >                                 return -EINVAL;
> >
> >                         d->dst_addr =
> > -                               ttm_kmap_atomic_prot(d->dst_pages[dst_page],
> > -                                                    d->dst_prot);
> > +                               kmap_atomic_prot(d->dst_pages[dst_page],
> > +                                                d->dst_prot);
> >                         if (!d->dst_addr)
> >                                 return -ENOMEM;
> >
> > @@ -401,8 +401,8 @@ static int vmw_bo_cpu_blit_line(struct vmw_bo_blit_line_data *d,
> >                                 return -EINVAL;
> >
> >                         d->src_addr =
> > -                               ttm_kmap_atomic_prot(d->src_pages[src_page],
> > -                                                    d->src_prot);
> > +                               kmap_atomic_prot(d->src_pages[src_page],
> > +                                                d->src_prot);
> >                         if (!d->src_addr)
> >                                 return -ENOMEM;
> >
> > @@ -499,9 +499,9 @@ int vmw_bo_cpu_blit(struct ttm_buffer_object *dst,
> >         }
> >  out:
> >         if (d.src_addr)
> > -               ttm_kunmap_atomic_prot(d.src_addr, d.src_prot);
> > +               kunmap_atomic(d.src_addr);
> >         if (d.dst_addr)
> > -               ttm_kunmap_atomic_prot(d.dst_addr, d.dst_prot);
> > +               kunmap_atomic(d.dst_addr);
> >
> >         return ret;
> >  }
> > diff --git a/include/drm/ttm/ttm_bo_api.h b/include/drm/ttm/ttm_bo_api.h
> > index 0a9d042e075a..de1ccdcd5703 100644
> > --- a/include/drm/ttm/ttm_bo_api.h
> > +++ b/include/drm/ttm/ttm_bo_api.h
> > @@ -668,10 +668,6 @@ int ttm_bo_mmap_obj(struct vm_area_struct *vma, struct ttm_buffer_object *bo);
> >  int ttm_bo_mmap(struct file *filp, struct vm_area_struct *vma,
> >                 struct ttm_bo_device *bdev);
> >
> > -void *ttm_kmap_atomic_prot(struct page *page, pgprot_t prot);
> > -
> > -void ttm_kunmap_atomic_prot(void *addr, pgprot_t prot);
> > -
> >  /**
> >   * ttm_bo_io
> >   *
> > --
> > 2.25.1
> >
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel@lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> 
> 
> -- 
> Daniel Vetter
> Software Engineer, Intel Corporation
> +41 (0) 79 365 57 48 - http://blog.ffwll.ch

Re: [PATCH V2 00/11] Subject: Remove duplicated kmap code

[Al Viro]

On Sun, May 03, 2020 at 06:09:01PM -0700, ira.weiny@intel.com wrote:
> From: Ira Weiny <ira.weiny@intel.com>
> 
> The kmap infrastructure has been copied almost verbatim to every architecture.
> This series consolidates obvious duplicated code by defining core functions
> which call into the architectures only when needed.
> 
> Some of the k[un]map_atomic() implementations have some similarities but the
> similarities were not sufficient to warrant further changes.
> 
> In addition we remove a duplicate implementation of kmap() in DRM.
> 
> Testing was done by 0day to cover all the architectures I can't readily
> build/test.

OK...  Looking through my old notes on kmap unification (this winter, never
went anywhere),

* arch/mips/mm/cache.c ought to use linux/highmem.h, not asm/highmem.h
I suspect that your series doesn't build on some configs there.  Hadn't
verified that, though.

* kmap_atomic_to_page() is dead, but not quite gone - csky and nds32 brought
the damn thing back (nds32 - only an extern).  It needs killin'...

* parisc is (arguably) abusing kunmap()/kunmap_atomic() for cache flushing.
Replace the bulk of its highmem.h with
#define ARCH_HAS_FLUSH_ON_KUNMAP
#define arch_before_kunmap flush_kernel_dcache_page_addr
and have default kunmap()/kunmap_atomic() do
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
	arch_before_kunmap(page_address(page));
#endif
and
#ifdef ARCH_HAS_FLUSH_ON_KUNMAP
	arch_before_kunmap(addr);
#endif
resp.  Kills ARCH_HAS_KMAP along with ifdefs on it, makes parisc use somewhat
less hacky.

I'd suggest checking various configs on mips - that's likely to cause headache.
Said that, my analysis of include chains back then is pretty much worthless
by now - I really hate the amount of indirect include chains leading to that
sucker on some, but not all configs ;-/  IIRC, the proof that everything
using kmap*/kunmap* would pull linux/highmem.h regardless of config took several
hours of digging, ran for several pages and had been hopelessly brittle.
arch/mips/mm/cache.c was the only exception caught by it, but these days
there might be more.

Re: [PATCH V2 00/11] Subject: Remove duplicated kmap code

[Ira Weiny]

On Mon, May 04, 2020 at 02:35:09AM +0100, Al Viro wrote:
> On Sun, May 03, 2020 at 06:09:01PM -0700, ira.weiny@intel.com wrote:
> > From: Ira Weiny <ira.weiny@intel.com>
> > 
> > The kmap infrastructure has been copied almost verbatim to every architecture.
> > This series consolidates obvious duplicated code by defining core functions
> > which call into the architectures only when needed.
> > 
> > Some of the k[un]map_atomic() implementations have some similarities but the
> > similarities were not sufficient to warrant further changes.
> > 
> > In addition we remove a duplicate implementation of kmap() in DRM.
> > 
> > Testing was done by 0day to cover all the architectures I can't readily
> > build/test.
> 
> OK...  Looking through my old notes on kmap unification (this winter, never
> went anywhere),
> 
> * arch/mips/mm/cache.c ought to use linux/highmem.h, not asm/highmem.h
> I suspect that your series doesn't build on some configs there.  Hadn't
> verified that, though.

Yes patch 6 makes the change because kmap_atomic() was no longer declared in
asm/highmem.h.  I'm pretty sure 0-day caught that ...  but I seem to remember
noticing some oddness in that file and I did go through it by hand.

> 
> * kmap_atomic_to_page() is dead, but not quite gone - csky and nds32 brought
> the damn thing back (nds32 - only an extern).  It needs killin'...

Easy enough. Added as a follow on patch.

> 
> * parisc is (arguably) abusing kunmap()/kunmap_atomic() for cache flushing.
> Replace the bulk of its highmem.h with
> #define ARCH_HAS_FLUSH_ON_KUNMAP
> #define arch_before_kunmap flush_kernel_dcache_page_addr
> and have default kunmap()/kunmap_atomic() do
> #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
> 	arch_before_kunmap(page_address(page));
> #endif
> and
> #ifdef ARCH_HAS_FLUSH_ON_KUNMAP
> 	arch_before_kunmap(addr);
> #endif
> resp.  Kills ARCH_HAS_KMAP along with ifdefs on it, makes parisc use somewhat
> less hacky.

Agreed.  Done in a follow on patch.

> 
> I'd suggest checking various configs on mips - that's likely to cause headache.
> Said that, my analysis of include chains back then is pretty much worthless
> by now - I really hate the amount of indirect include chains leading to that
> sucker on some, but not all configs ;-/  IIRC, the proof that everything
> using kmap*/kunmap* would pull linux/highmem.h regardless of config took several
> hours of digging, ran for several pages and had been hopelessly brittle.
> arch/mips/mm/cache.c was the only exception caught by it, but these days
> there might be more.

Grepping for 'asm/highmem.h' and investigations don't reveal any issues...  But
you do have me worried.  That said 0-day has been crunching on multiple
versions of this series without issues such as this (save the mips issue
above).

I have to say it would be nice if the relation between linux/highmem.h and
asm/highmem.h was more straightforward.

Ira

Re: [PATCH V2 00/11] Subject: Remove duplicated kmap code

[Al Viro]

On Sun, May 03, 2020 at 10:04:47PM -0700, Ira Weiny wrote:

> Grepping for 'asm/highmem.h' and investigations don't reveal any issues...  But
> you do have me worried.  That said 0-day has been crunching on multiple
> versions of this series without issues such as this (save the mips issue
> above).
> 
> I have to say it would be nice if the relation between linux/highmem.h and
> asm/highmem.h was more straightforward.

IIRC, the headache was due to asm/pgtable.h on several architectures and
asm/cacheflush.h on parisc.

<digs the notes out>

||         IOW, there's one in linux/highmem.h (conditional on !CONFIG_HIGHMEM,
|| !ARCH_HAS_KMAP) and several per-architecture variants, usually declared in
|| their asm/highmem.h.  In three of those (microblaze, parisc and powerpc) these
|| are inlines (parisc one identical to linux/highmem.h, lives in asm/cacheflush.h,
|| powerpc and microblaze ones calling kmap_atomic_prot() which is defined in
|| arch/$ARCH/mm/highmem.c).
|| 
||         parisc case is weird - essentially, they want to call 
|| flush_kernel_dcache_page_addr() at the places where kunmap/kunmap_atomic
|| is done.  And they do so despite not selecting HIGHMEM, with definitions
|| in usual place.  They do have ARCH_HAS_KMAP defined, which prevents
|| getting buggered in linux/highmem.h.  ARCH_HAS_KMAP is parisc-unique,
|| BTW, and checked only in linux/highmem.h.
|| 
||         All genuine arch-specific variants are defined in (or call functions
|| defined in) translation units that are only included CONFIG_HIGHMEM builds.
|| 
||         It would be tempting to consolidate those, e.g. by adding __kmap_atomic()
|| and __kmap_atomic_prot() without that boilerplate, with universal kmap_atomic()
|| and kmap_atomic_prot() in linux/highmem.h.  Potential problem with that would
|| be something that pulls ash/highmem.h (or asm/cacheflush.h in case of parisc)
|| directly and uses kmap_atomic/kmap_atomic_prot.  There's not a lot places
|| pulling asm/highmem.h, and many of them are not even in includes:
|| 
|| arch/arm/include/asm/efi.h:13:#include <asm/highmem.h>
|| arch/arm/mm/dma-mapping.c:31:#include <asm/highmem.h>
|| arch/arm/mm/flush.c:14:#include <asm/highmem.h>
|| arch/arm/mm/mmu.c:27:#include <asm/highmem.h>
|| arch/mips/include/asm/pgtable-32.h:22:#include <asm/highmem.h>
|| arch/mips/mm/cache.c:19:#include <asm/highmem.h>
|| arch/mips/mm/fault.c:28:#include <asm/highmem.h>                /* For VMALLOC_END */
|| arch/nds32/include/asm/pgtable.h:60:#include <asm/highmem.h>
|| arch/x86/kernel/setup_percpu.c:20:#include <asm/highmem.h>
|| include/linux/highmem.h:35:#include <asm/highmem.h>
|| 
|| Users of asm/cacheflush.h are rather more numerous; however, anything
|| outside of parisc-specific code has to pull linux/highmem.h, or it won't see
|| the definitions of kmap_atomic/kmap_atomic_prot at all.  arch/parisc itself
|| has no callers of those.
|| 
|| Outside of arch/* there is a plenty of callers.  However, the following is
|| true: all instances of kmap_atomic or kmap_atomic_prot outside of arch/*
|| are either inside the linux/highmem.h or are preceded by include of
|| linux/highmem.h on any build that sees them (there is a common include
|| chain that is conditional upon CONFIG_BLOCK, but it's only needed in
|| drivers that are BLOCK-dependent).  It was not fun to verify, to put
|| it mildly...
|| 
|| So for parisc we have no problem - leaving __kmap_atomic()/__kmap_atomic_prot()
|| in asm/cachefile.h and adding universal wrappers in linux/highmem.h will be
|| fine.  For other architectures the things might be trickier.
|| 
|| * arc: all users in arch/arc/ are within arch/arc/mm/{cache,highmem}.c;
|| both pull linux/highmem.h.  We are fine.
|| 
|| * arm: much, much worse.  We have several files that pull linux/highmem.h:
|| arch/arm/mm/cache-feroceon-l2.c, arch/arm/mm/cache-xsc3l2.c,
|| arch/arm/mm/copypage-*.c, arch/arm/mm/dma-mapping.c, arch/arm/mm/flush.c,
|| arch/arm/mm/highmem.c, arch/arm/probes/uprobes/core.c,
|| arch/arm/include/asm/kvm_mmu.h (kmap_atomic_pfn()).
|| Those are fine, but we also have this:
|| arch/arm/include/asm/pgtable.h:200:#define __pte_map(pmd)               (pte_t *)kmap_atomic(pmd_page(*(pmd)))
|| arch/arm/include/asm/pgtable.h:208:#define pte_offset_map(pmd,addr)     (__pte_map(pmd) + pte_index(addr))
|| and sure as hell, asm/pgtable.h does *NOT* pull linux/highmem.h.
|| 
|| Fortunately, the users of pte_offset_map() (__pte_map() has no other users)
|| are few, both in arch/arm and outside of arch.  All arm ones are pulling
|| linux/highmem (arch/arm/mm/{pgd,fault*}.c).  Outside of arch we have several
|| that pull highmem.h (by way of rmap.h or pagemap.h, usually):
||         fs/userfaultfd.c, mm/gup.c, mm/hmm.c, mm/huge_memory.c,
||         mm/khugepaged.c, mm/memory-failure.c, mm/memory.c, mm/migrate.c,
||         mm/mremap.c, mm/page_vma_mapped.c, mm/swap_state.c, mm/swapfile.c,
||         mm/vmalloc.c
|| and then there are these in linux/mm.h:
|| 
|| #define pte_offset_map_lock(mm, pmd, address, ptlp)     \
|| ({                                                      \
||         spinlock_t *__ptl = pte_lockptr(mm, pmd);       \
||         pte_t *__pte = pte_offset_map(pmd, address);    \
||         *(ptlp) = __ptl;                                \
||         spin_lock(__ptl);                               \
||         __pte;                                          \
|| })
|| #define pte_alloc_map(mm, pmd, address)                 \
||         (pte_alloc(mm, pmd) ? NULL : pte_offset_map(pmd, address))
|| #define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
||         (pte_alloc(mm, pmd) ?                   \
||                  NULL : pte_offset_map_lock(mm, pmd, address, ptlp))
|| 
||         These have two users in arch/arm (arch/arm/mm/pgd.c and
|| arch/arm/lib/uaccess_with_memcpy.c, both pulling highmem.h).  Outside of
|| arch there are several new files (plus a lot of what we'd already seen
|| in mm/*.c, unsurprisingly):
||         fs/proc/task_mmu.c, mm/ksm.c, mm/madvise.c, mm/memcontrol.c,
||         mm/mempolicy.c, mm/mincore.c, mm/mprotect.c, mm/pagewalk.c,
||         mm/shmem.c, mm/userfaultfd.c,
|| all pulling linux/highmem.h, as pretty much all core VM does.  So we are
|| still fine.
|| 
|| * csky: users in arch/csky/abiv2/cacheflush.c, arch/csky/mm/dma-mapping.c,
|| arch/csky/mm/highmem.c, all pulling linux/highmem.h
|| 
|| * microblaze: users in arch/microblaze/mm/highmem.c (pulls linux/highmem.h) and,
|| arch/microblaze/include/asm/pgtable.h, this:
|| #define pte_offset_map(dir, addr)               \
||         ((pte_t *) kmap_atomic(pmd_page(*(dir))) + pte_index(addr))
||         One pte_offset_map user in arch/microblaze:
|| arch/microblaze/kernel/signal.c:207:    ptep = pte_offset_map(pmdp, address);
|| Messy, but doesn't require any changes (we have asm/pgalloc.h included
|| there, and that pull linux/highmem.h).
||         Outside of arch we'd already sorted it out when looking at arm.
|| 
|| * mips: users in arch/mips/kernel/crash_dump.c, arch/mips/kernel/uprobes.c,
|| arch/mips/mm/c-r4k.c, arch/mips/mm/dma-noncoherent.c, arch/mips/mm/highmem.c,
|| and arch/mips/mm/init.c (all pulling linux/highmem.h) plus this
|| arch/mips/mm/cache.c, which relies upon asm/highmem.h.  This can be switched
|| to linux/highmem.h.  On !CONFIG_HIGHMEM builds the call of kmap_atomic() in
|| there is eliminated, since it's conditional upon PageHighMem().  IOW, even
|| though we get a call of (inexistent) out-of-line version, it's not going to
|| survive into object file.  With linux/highmem.h use it will be an equally
|| eliminated call of inlined version.
|| XXX: arch/mips/mm/cache.c
|| 
|| * nds32: users in arch/nds32/kernel/dma.c, arch/nds32/mm/cacheflush.c and
|| arch/nds32/mm/highmem.c, all pulling linux/highmem.h
|| 
|| * powerpc: users in arch/powerpc/kvm/book3s_pr.c,
|| arch/powerpc/kvm/e500_mmu_host.c, arch/powerpc/mm/dma-noncoherent.c,
|| arch/powerpc/mm/highmem.c and arch/powerpc/mm/mem.c, all pulling
|| linux/highmem.h, a user in arch/powerpc/mm/hugetlbpage.c pulling it
|| via asm/tlb.h -> linux/pagemap.h -> linux/highmem.h and
|| macros for pte_offset_map in arch/powerpc/include/asm/*/32/pgtable.h.
|| Users of that within arch/powerpc are either 64bit-only or
|| pull linux/highmem.h (arch/powerpc/mm/pgtable_32.c and
|| arch/powerpc/xmon/xmon.c).  Users outside of arch - same as for arm.
|| 
|| * sparc: users in arch/sparc/kernel/uprobes.c and arch/sparc/mm/highmem.c
|| (both pulling linux/highmem.h directly) + arch/sparc/mm/init_64.c pulling
|| it via linux/pagemap.h.  Strangely, arch/sparc/mm/io-unit.c and
|| arch/sparc/mm/iommu.c both include linux/highmem.h with odd comment
|| that seems to indicate that once upon a time pte_offset_map() used to
|| requite kmap_atomic() there...  Right, it used to - until 2002.
|| These includes are pointless, then...
|| 
|| * x86: users in arch/x86/kernel/crash_dump_32.c, arch/x86/kvm/svm.c,
|| arch/x86/lib/usercopy_64.c, arch/x86/mm/highmem_32.c and arch/x86/mm/iomap_32.c,
|| all pulling linux/highmem.h, users in paging_tmpl.h (included from
|| arch/x86/kvm/mmu/mmu.c, which has pulled linux/highmem.h prior to that)
|| and definition of pte_offset_map() (in asm/pgtable_32.h)
|| Users of pte_offset_map() and friends in arch/x86 are in
|| arch/x86/kernel/vm86_32.c and arch/x86/mm/dump_pagetables.c (both
|| pulling linux/highmem.h), in arch/x86/mm/mem_encrypt_identity.c
|| (64bit-only, pte_offset_map() doesn't use kmap_atomic() there) and
|| arch/x86/kernel/tboot.c (pulls linux/highmem.h via asm/pgalloc.h
|| and linux/pagemap.h)
|| 
|| * xtensa: users in arch/xtensa/kernel/pci-dma.c, arch/xtensa/mm/highmem.c,
|| arch/xtensa/mm/cache.c and arch/xtensa/platforms/iss/simdisk.c (all pull
|| linux/highmem.h).

Re: [PATCH V2 00/11] Subject: Remove duplicated kmap code

[Ira Weiny]

On Mon, May 04, 2020 at 06:33:57AM +0100, Al Viro wrote:
> On Sun, May 03, 2020 at 10:04:47PM -0700, Ira Weiny wrote:
> 
> > Grepping for 'asm/highmem.h' and investigations don't reveal any issues...  But
> > you do have me worried.  That said 0-day has been crunching on multiple
> > versions of this series without issues such as this (save the mips issue
> > above).
> > 
> > I have to say it would be nice if the relation between linux/highmem.h and
> > asm/highmem.h was more straightforward.
> 
> IIRC, the headache was due to asm/pgtable.h on several architectures and
> asm/cacheflush.h on parisc.
> 
> <digs the notes out>
> 
> ||         IOW, there's one in linux/highmem.h (conditional on !CONFIG_HIGHMEM,
> || !ARCH_HAS_KMAP) and several per-architecture variants, usually declared in
> || their asm/highmem.h.  In three of those (microblaze, parisc and powerpc) these
> || are inlines (parisc one identical to linux/highmem.h, lives in asm/cacheflush.h,
> || powerpc and microblaze ones calling kmap_atomic_prot() which is defined in
> || arch/$ARCH/mm/highmem.c).
> || 
> ||         parisc case is weird - essentially, they want to call 
> || flush_kernel_dcache_page_addr() at the places where kunmap/kunmap_atomic
> || is done.  And they do so despite not selecting HIGHMEM, with definitions
> || in usual place.  They do have ARCH_HAS_KMAP defined, which prevents
> || getting buggered in linux/highmem.h.  ARCH_HAS_KMAP is parisc-unique,
> || BTW, and checked only in linux/highmem.h.
> || 
> ||         All genuine arch-specific variants are defined in (or call functions
> || defined in) translation units that are only included CONFIG_HIGHMEM builds.

I agree with this statement.  But IMO additional confusion is caused by the
fact that some arch's condition the declarations on CONFIG_HIGHMEM within
asm/highmem.h (arc, arm, nds32) while others depend on linux/highmem.h (and
elsewhere) to do so (csky, microblaze, mips, powerpc, sparc, x86, xtensa).

Why?

I think (perhaps naive) over time asm/highmem.h needs to be isolated to being
included in linux/highmem.h.  But as you point out below that is not so easy.
I think that this series helps toward that goal.

> || 
> ||         It would be tempting to consolidate those, e.g. by adding __kmap_atomic()
> || and __kmap_atomic_prot() without that boilerplate, with universal kmap_atomic()
> || and kmap_atomic_prot() in linux/highmem.h.  Potential problem with that would
> || be something that pulls ash/highmem.h (or asm/cacheflush.h in case of parisc)
> || directly and uses kmap_atomic/kmap_atomic_prot.  There's not a lot places
> || pulling asm/highmem.h, and many of them are not even in includes:
> || 
> || arch/arm/include/asm/efi.h:13:#include <asm/highmem.h>
> || arch/arm/mm/dma-mapping.c:31:#include <asm/highmem.h>
> || arch/arm/mm/flush.c:14:#include <asm/highmem.h>
> || arch/arm/mm/mmu.c:27:#include <asm/highmem.h>
> || arch/mips/include/asm/pgtable-32.h:22:#include <asm/highmem.h>
> || arch/mips/mm/cache.c:19:#include <asm/highmem.h>
> || arch/mips/mm/fault.c:28:#include <asm/highmem.h>                /* For VMALLOC_END */
> || arch/nds32/include/asm/pgtable.h:60:#include <asm/highmem.h>
> || arch/x86/kernel/setup_percpu.c:20:#include <asm/highmem.h>
> || include/linux/highmem.h:35:#include <asm/highmem.h>
> || 
> || Users of asm/cacheflush.h are rather more numerous; however, anything
> || outside of parisc-specific code has to pull linux/highmem.h, or it won't see
> || the definitions of kmap_atomic/kmap_atomic_prot at all.  arch/parisc itself
> || has no callers of those.
> || 
> || Outside of arch/* there is a plenty of callers.  However, the following is
> || true: all instances of kmap_atomic or kmap_atomic_prot outside of arch/*
> || are either inside the linux/highmem.h or are preceded by include of
> || linux/highmem.h on any build that sees them (there is a common include
> || chain that is conditional upon CONFIG_BLOCK, but it's only needed in
> || drivers that are BLOCK-dependent).  It was not fun to verify, to put
> || it mildly...
> || 
> || So for parisc we have no problem - leaving __kmap_atomic()/__kmap_atomic_prot()
> || in asm/cachefile.h and adding universal wrappers in linux/highmem.h will be
> || fine.  For other architectures the things might be trickier.

And the follow up series removes kmap_* from asm/cachefile.h in parisc which
should be cleaner going forward.

> || 
> || * arc: all users in arch/arc/ are within arch/arc/mm/{cache,highmem}.c;
> || both pull linux/highmem.h.  We are fine.

Still fine.

> || 
> || * arm: much, much worse.  We have several files that pull linux/highmem.h:
> || arch/arm/mm/cache-feroceon-l2.c, arch/arm/mm/cache-xsc3l2.c,
> || arch/arm/mm/copypage-*.c, arch/arm/mm/dma-mapping.c, arch/arm/mm/flush.c,
> || arch/arm/mm/highmem.c, arch/arm/probes/uprobes/core.c,
> || arch/arm/include/asm/kvm_mmu.h (kmap_atomic_pfn()).
> || Those are fine, but we also have this:
> || arch/arm/include/asm/pgtable.h:200:#define __pte_map(pmd)               (pte_t *)kmap_atomic(pmd_page(*(pmd)))
> || arch/arm/include/asm/pgtable.h:208:#define pte_offset_map(pmd,addr)     (__pte_map(pmd) + pte_index(addr))
> || and sure as hell, asm/pgtable.h does *NOT* pull linux/highmem.h.

It does not pull asm/highmem.h either...

> || 
> || Fortunately, the users of pte_offset_map() (__pte_map() has no other users)
> || are few, both in arch/arm and outside of arch.  All arm ones are pulling
> || linux/highmem (arch/arm/mm/{pgd,fault*}.c).  Outside of arch we have several
> || that pull highmem.h (by way of rmap.h or pagemap.h, usually):
> ||         fs/userfaultfd.c, mm/gup.c, mm/hmm.c, mm/huge_memory.c,
> ||         mm/khugepaged.c, mm/memory-failure.c, mm/memory.c, mm/migrate.c,
> ||         mm/mremap.c, mm/page_vma_mapped.c, mm/swap_state.c, mm/swapfile.c,
> ||         mm/vmalloc.c
> || and then there are these in linux/mm.h:
> || 
> || #define pte_offset_map_lock(mm, pmd, address, ptlp)     \
> || ({                                                      \
> ||         spinlock_t *__ptl = pte_lockptr(mm, pmd);       \
> ||         pte_t *__pte = pte_offset_map(pmd, address);    \
> ||         *(ptlp) = __ptl;                                \
> ||         spin_lock(__ptl);                               \
> ||         __pte;                                          \
> || })
> || #define pte_alloc_map(mm, pmd, address)                 \
> ||         (pte_alloc(mm, pmd) ? NULL : pte_offset_map(pmd, address))
> || #define pte_alloc_map_lock(mm, pmd, address, ptlp)      \
> ||         (pte_alloc(mm, pmd) ?                   \
> ||                  NULL : pte_offset_map_lock(mm, pmd, address, ptlp))
> || 
> ||         These have two users in arch/arm (arch/arm/mm/pgd.c and
> || arch/arm/lib/uaccess_with_memcpy.c, both pulling highmem.h).  Outside of
> || arch there are several new files (plus a lot of what we'd already seen
> || in mm/*.c, unsurprisingly):
> ||         fs/proc/task_mmu.c, mm/ksm.c, mm/madvise.c, mm/memcontrol.c,
> ||         mm/mempolicy.c, mm/mincore.c, mm/mprotect.c, mm/pagewalk.c,
> ||         mm/shmem.c, mm/userfaultfd.c,
> || all pulling linux/highmem.h, as pretty much all core VM does.  So we are
> || still fine.

This all seems the same now.

> || 
> || * csky: users in arch/csky/abiv2/cacheflush.c, arch/csky/mm/dma-mapping.c,
> || arch/csky/mm/highmem.c, all pulling linux/highmem.h

Yes still are.

> || 
> || * microblaze: users in arch/microblaze/mm/highmem.c (pulls linux/highmem.h) and,
> || arch/microblaze/include/asm/pgtable.h, this:
> || #define pte_offset_map(dir, addr)               \
> ||         ((pte_t *) kmap_atomic(pmd_page(*(dir))) + pte_index(addr))
> ||         One pte_offset_map user in arch/microblaze:
> || arch/microblaze/kernel/signal.c:207:    ptep = pte_offset_map(pmdp, address);
> || Messy, but doesn't require any changes (we have asm/pgalloc.h included
> || there, and that pull linux/highmem.h).

AFAICS asm/pgtable.h does not include asm/highmem.h here...

So looks like arch/microblaze/kernel/signal.c will need linux/highmem.h

> ||         Outside of arch we'd already sorted it out when looking at arm.
> || 
> || * mips: users in arch/mips/kernel/crash_dump.c, arch/mips/kernel/uprobes.c,
> || arch/mips/mm/c-r4k.c, arch/mips/mm/dma-noncoherent.c, arch/mips/mm/highmem.c,
> || and arch/mips/mm/init.c (all pulling linux/highmem.h) plus this
> || arch/mips/mm/cache.c, which relies upon asm/highmem.h.  This can be switched
> || to linux/highmem.h.  On !CONFIG_HIGHMEM builds the call of kmap_atomic() in
> || there is eliminated, since it's conditional upon PageHighMem().  IOW, even
> || though we get a call of (inexistent) out-of-line version, it's not going to
> || survive into object file.  With linux/highmem.h use it will be an equally
> || eliminated call of inlined version.
> || XXX: arch/mips/mm/cache.c

Fixed as part of this series.

> || 
> || * nds32: users in arch/nds32/kernel/dma.c, arch/nds32/mm/cacheflush.c and
> || arch/nds32/mm/highmem.c, all pulling linux/highmem.h

Still looks ok.

> || 
> || * powerpc: users in arch/powerpc/kvm/book3s_pr.c,
> || arch/powerpc/kvm/e500_mmu_host.c, arch/powerpc/mm/dma-noncoherent.c,
> || arch/powerpc/mm/highmem.c and arch/powerpc/mm/mem.c, all pulling
> || linux/highmem.h,

still good

> a user in arch/powerpc/mm/hugetlbpage.c pulling it
> || via asm/tlb.h -> linux/pagemap.h -> linux/highmem.h

good

> and
> || macros for pte_offset_map in arch/powerpc/include/asm/*/32/pgtable.h.
> || Users of that within arch/powerpc are either 64bit-only or
> || pull linux/highmem.h (arch/powerpc/mm/pgtable_32.c and
> || arch/powerpc/xmon/xmon.c).
>

Looks ok.

> || Users outside of arch - same as for arm.
> || 
> || * sparc: users in arch/sparc/kernel/uprobes.c and arch/sparc/mm/highmem.c
> || (both pulling linux/highmem.h directly) + arch/sparc/mm/init_64.c pulling
> || it via linux/pagemap.h.

Looks ok.

> Strangely, arch/sparc/mm/io-unit.c and
> || arch/sparc/mm/iommu.c both include linux/highmem.h with odd comment
> || that seems to indicate that once upon a time pte_offset_map() used to
> || requite kmap_atomic() there...  Right, it used to - until 2002.
> || These includes are pointless, then...

Looks like it...

I'll throw in a patch for that.

> || 
> || * x86: users in arch/x86/kernel/crash_dump_32.c, arch/x86/kvm/svm.c,
> || arch/x86/lib/usercopy_64.c, arch/x86/mm/highmem_32.c and arch/x86/mm/iomap_32.c,
> || all pulling linux/highmem.h, users in paging_tmpl.h (included from
> || arch/x86/kvm/mmu/mmu.c, which has pulled linux/highmem.h prior to that)
> || and definition of pte_offset_map() (in asm/pgtable_32.h)
> || Users of pte_offset_map() and friends in arch/x86 are in
> || arch/x86/kernel/vm86_32.c and arch/x86/mm/dump_pagetables.c (both
> || pulling linux/highmem.h), in arch/x86/mm/mem_encrypt_identity.c
> || (64bit-only, pte_offset_map() doesn't use kmap_atomic() there) and
> || arch/x86/kernel/tboot.c (pulls linux/highmem.h via asm/pgalloc.h
> || and linux/pagemap.h)

I've built these and they seem fine.

> || 
> || * xtensa: users in arch/xtensa/kernel/pci-dma.c, arch/xtensa/mm/highmem.c,
> || arch/xtensa/mm/cache.c and arch/xtensa/platforms/iss/simdisk.c (all pull
> || linux/highmem.h).

Actually

arch/xtensa/mm/cache.c gets linux/highmem.h from linux/pagemap.h

arch/xtensa/platforms/iss/simdisk.c may have an issue?
	linux/blkdev.h -> CONFIG_BLOCK -> linux/pagemap.h -> linux/highmem.h
	But simdisk.c requires BLK_DEV_SIMDISK -> CONFIG_BLOCK...
	<sigh>

So xtensa still seems good AFAICS.


In summary it looks like the use of kmap_atomic() in pte_offset_map() is a
potential issue in microblaze.  I've fixed that in my local tree.

Ira

Re: [PATCH V2 00/11] Subject: Remove duplicated kmap code

[Al Viro]

On Mon, May 04, 2020 at 01:17:41PM -0700, Ira Weiny wrote:

> > || * arm: much, much worse.  We have several files that pull linux/highmem.h:
> > || arch/arm/mm/cache-feroceon-l2.c, arch/arm/mm/cache-xsc3l2.c,
> > || arch/arm/mm/copypage-*.c, arch/arm/mm/dma-mapping.c, arch/arm/mm/flush.c,
> > || arch/arm/mm/highmem.c, arch/arm/probes/uprobes/core.c,
> > || arch/arm/include/asm/kvm_mmu.h (kmap_atomic_pfn()).
> > || Those are fine, but we also have this:
> > || arch/arm/include/asm/pgtable.h:200:#define __pte_map(pmd)               (pte_t *)kmap_atomic(pmd_page(*(pmd)))
> > || arch/arm/include/asm/pgtable.h:208:#define pte_offset_map(pmd,addr)     (__pte_map(pmd) + pte_index(addr))
> > || and sure as hell, asm/pgtable.h does *NOT* pull linux/highmem.h.
> 
> It does not pull asm/highmem.h either...

No, but the users of those macros need to be considered.

> > || #define pte_offset_map(dir, addr)               \
> > ||         ((pte_t *) kmap_atomic(pmd_page(*(dir))) + pte_index(addr))
> > ||         One pte_offset_map user in arch/microblaze:
> > || arch/microblaze/kernel/signal.c:207:    ptep = pte_offset_map(pmdp, address);
> > || Messy, but doesn't require any changes (we have asm/pgalloc.h included
> > || there, and that pull linux/highmem.h).
> 
> AFAICS asm/pgtable.h does not include asm/highmem.h here...
> 
> So looks like arch/microblaze/kernel/signal.c will need linux/highmem.h

See above - line 39 in there is
#include <asm/pgalloc.h>
and line 14 in arch/microblaze/include/asm/pgalloc.h is
#include <linux/highmem.h>
It's conditional upon CONFIG_MMU in there, but so's the use of
pte_offset_map() in arch/microblaze/kernel/signal.c 

So it shouldn't be a problem.

> > || * xtensa: users in arch/xtensa/kernel/pci-dma.c, arch/xtensa/mm/highmem.c,
> > || arch/xtensa/mm/cache.c and arch/xtensa/platforms/iss/simdisk.c (all pull
> > || linux/highmem.h).
> 
> Actually
> 
> arch/xtensa/mm/cache.c gets linux/highmem.h from linux/pagemap.h
> 
> arch/xtensa/platforms/iss/simdisk.c may have an issue?
> 	linux/blkdev.h -> CONFIG_BLOCK -> linux/pagemap.h -> linux/highmem.h
> 	But simdisk.c requires BLK_DEV_SIMDISK -> CONFIG_BLOCK...
> 	<sigh>

Yep - see above re major chain of indirect includes conditional upon CONFIG_BLOCK
and its uses in places that only build with such configs.  There's a plenty of
similar considerations outside of arch/*, unfortunately...

Re: [PATCH V2 00/11] Subject: Remove duplicated kmap code

[Ira Weiny]

On Mon, May 04, 2020 at 10:02:25PM +0100, Al Viro wrote:
> On Mon, May 04, 2020 at 01:17:41PM -0700, Ira Weiny wrote:
> 
> > > || * arm: much, much worse.  We have several files that pull linux/highmem.h:
> > > || arch/arm/mm/cache-feroceon-l2.c, arch/arm/mm/cache-xsc3l2.c,
> > > || arch/arm/mm/copypage-*.c, arch/arm/mm/dma-mapping.c, arch/arm/mm/flush.c,
> > > || arch/arm/mm/highmem.c, arch/arm/probes/uprobes/core.c,
> > > || arch/arm/include/asm/kvm_mmu.h (kmap_atomic_pfn()).
> > > || Those are fine, but we also have this:
> > > || arch/arm/include/asm/pgtable.h:200:#define __pte_map(pmd)               (pte_t *)kmap_atomic(pmd_page(*(pmd)))
> > > || arch/arm/include/asm/pgtable.h:208:#define pte_offset_map(pmd,addr)     (__pte_map(pmd) + pte_index(addr))
> > > || and sure as hell, asm/pgtable.h does *NOT* pull linux/highmem.h.
> > 
> > It does not pull asm/highmem.h either...
> 
> No, but the users of those macros need to be considered.

Agreed, I was trying to point out that highmem.h was being pulled from
somewhere else prior to my series, sorry.

> 
> > > || #define pte_offset_map(dir, addr)               \
> > > ||         ((pte_t *) kmap_atomic(pmd_page(*(dir))) + pte_index(addr))
> > > ||         One pte_offset_map user in arch/microblaze:
> > > || arch/microblaze/kernel/signal.c:207:    ptep = pte_offset_map(pmdp, address);
> > > || Messy, but doesn't require any changes (we have asm/pgalloc.h included
> > > || there, and that pull linux/highmem.h).
> > 
> > AFAICS asm/pgtable.h does not include asm/highmem.h here...
> > 
> > So looks like arch/microblaze/kernel/signal.c will need linux/highmem.h
> 
> See above - line 39 in there is
> #include <asm/pgalloc.h>
> and line 14 in arch/microblaze/include/asm/pgalloc.h is
> #include <linux/highmem.h>
> It's conditional upon CONFIG_MMU in there, but so's the use of
> pte_offset_map() in arch/microblaze/kernel/signal.c 
> 
> So it shouldn't be a problem.

Ah ok, I did not see that one.  Ok I'll drop that change and this series should
be good.

I was setting up to submit another version with 3 more patches you have
suggested:

kmap: Remove kmap_atomic_to_page()
parisc/kmap: Remove duplicate kmap code
sparc: Remove unnecessary includes

Would you like to see those folded in?  I submitted 2 of the above as a
separate series already.

> 
> > > || * xtensa: users in arch/xtensa/kernel/pci-dma.c, arch/xtensa/mm/highmem.c,
> > > || arch/xtensa/mm/cache.c and arch/xtensa/platforms/iss/simdisk.c (all pull
> > > || linux/highmem.h).
> > 
> > Actually
> > 
> > arch/xtensa/mm/cache.c gets linux/highmem.h from linux/pagemap.h
> > 
> > arch/xtensa/platforms/iss/simdisk.c may have an issue?
> > 	linux/blkdev.h -> CONFIG_BLOCK -> linux/pagemap.h -> linux/highmem.h
> > 	But simdisk.c requires BLK_DEV_SIMDISK -> CONFIG_BLOCK...
> > 	<sigh>
> 
> Yep - see above re major chain of indirect includes conditional upon CONFIG_BLOCK
> and its uses in places that only build with such configs.  There's a plenty of
> similar considerations outside of arch/*, unfortunately...

Indeed.

FWIW the last 2 versions of this series have had no build failures with 0-day.

This series in particular just finished 164 configs without issue.

Would you like me to submit a new series?  With your additional patches?

Ira