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* [PATCH 0/5] Remove duplicated kmap code
@ 2020-04-26  5:54 ira.weiny
  2020-04-26  5:54 ` [PATCH 1/5] arch/kmap: Remove BUG_ON() ira.weiny
                   ` (4 more replies)
  0 siblings, 5 replies; 11+ messages in thread
From: ira.weiny @ 2020-04-26  5:54 UTC (permalink / raw)
  To: linux-kernel, Andrew Morton
  Cc: Ira Weiny, Thomas Bogendoerfer, James E.J. Bottomley,
	Helge Deller, Benjamin Herrenschmidt, Paul Mackerras,
	David S. Miller, Thomas Gleixner, Ingo Molnar, Borislav Petkov,
	x86, H. Peter Anvin, Dave Hansen, Andy Lutomirski,
	Peter Zijlstra, Chris Zankel, Max Filippov, Dan Williams,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

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

The kmap infrastructure has been copied almost verbatim to every architecture.
This series consolidates obvious duplicated code.  (k[un]map_atmoic has some
additional duplication between some of the architectures but the differences
were such to not warrant further changes.)

0day built successfully to cover all the architectures I can't readily build.

Ira Weiny (5):
  arch/kmap: Remove BUG_ON()
  arch/kmap: Remove redundant arch specific kmaps
  arch/kunmap: Remove duplicate kunmap implementations
  arch/kmap_atomic: Consolidate duplicate code
  arch/kunmap_atomic: Consolidate duplicate code

 arch/arc/include/asm/highmem.h        | 11 -------
 arch/arc/mm/highmem.c                 | 20 ++-----------
 arch/arm/include/asm/highmem.h        |  3 --
 arch/arm/mm/highmem.c                 | 28 ++----------------
 arch/csky/include/asm/highmem.h       |  3 +-
 arch/csky/mm/highmem.c                | 28 ++++--------------
 arch/microblaze/include/asm/highmem.h | 17 -----------
 arch/microblaze/mm/highmem.c          | 10 ++-----
 arch/mips/include/asm/highmem.h       |  3 +-
 arch/mips/mm/highmem.c                | 25 +++-------------
 arch/nds32/include/asm/highmem.h      |  3 --
 arch/nds32/mm/highmem.c               | 31 ++------------------
 arch/parisc/include/asm/cacheflush.h  |  2 --
 arch/powerpc/include/asm/highmem.h    | 17 -----------
 arch/powerpc/mm/highmem.c             |  9 ++----
 arch/sparc/include/asm/highmem.h      | 17 -----------
 arch/sparc/mm/highmem.c               |  9 ++----
 arch/x86/include/asm/highmem.h        |  4 ---
 arch/x86/mm/highmem_32.c              | 30 ++------------------
 arch/xtensa/include/asm/highmem.h     | 14 +--------
 arch/xtensa/mm/highmem.c              | 10 ++-----
 include/linux/highmem.h               | 41 +++++++++++++++++++++++++--
 22 files changed, 75 insertions(+), 260 deletions(-)

-- 
2.25.1


^ permalink raw reply	[flat|nested] 11+ messages in thread

* [PATCH 1/5] arch/kmap: Remove BUG_ON()
  2020-04-26  5:54 [PATCH 0/5] Remove duplicated kmap code ira.weiny
@ 2020-04-26  5:54 ` ira.weiny
  2020-04-26  5:54 ` [PATCH 2/5] arch/kmap: Remove redundant arch specific kmaps ira.weiny
                   ` (3 subsequent siblings)
  4 siblings, 0 replies; 11+ messages in thread
From: ira.weiny @ 2020-04-26  5:54 UTC (permalink / raw)
  To: linux-kernel, Andrew Morton
  Cc: Ira Weiny, Dan Williams, Thomas Bogendoerfer,
	James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
	Paul Mackerras, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, Dave Hansen,
	Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

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>
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


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH 2/5] arch/kmap: Remove redundant arch specific kmaps
  2020-04-26  5:54 [PATCH 0/5] Remove duplicated kmap code ira.weiny
  2020-04-26  5:54 ` [PATCH 1/5] arch/kmap: Remove BUG_ON() ira.weiny
@ 2020-04-26  5:54 ` ira.weiny
  2020-04-26  7:17   ` Christoph Hellwig
  2020-04-26  5:54 ` [PATCH 3/5] arch/kunmap: Remove duplicate kunmap implementations ira.weiny
                   ` (2 subsequent siblings)
  4 siblings, 1 reply; 11+ messages in thread
From: ira.weiny @ 2020-04-26  5:54 UTC (permalink / raw)
  To: linux-kernel, Andrew Morton
  Cc: Ira Weiny, Dan Williams, Thomas Bogendoerfer,
	James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
	Paul Mackerras, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, Dave Hansen,
	Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

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 to indicate if an
arch needs a special kmap.

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: Dan Williams <dan.j.williams@intel.com>
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       |  2 +-
 arch/csky/mm/highmem.c                |  7 +------
 arch/microblaze/include/asm/highmem.h |  9 ---------
 arch/mips/include/asm/highmem.h       |  2 +-
 arch/mips/mm/highmem.c                |  7 +------
 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     |  6 +-----
 include/linux/highmem.h               | 18 ++++++++++++++++++
 17 files changed, 23 insertions(+), 94 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..4caeff143748 100644
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -30,9 +30,9 @@ 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 *kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 
+#define ARCH_HAS_KMAP
 extern void *kmap(struct page *page);
 extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 690d678649d1..5fb0bd855444 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -15,14 +15,9 @@ unsigned long highstart_pfn, highend_pfn;
 
 void *kmap(struct page *page)
 {
-	void *addr;
+	void *addr = kmap_generic(page);
 
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	addr = kmap_high(page);
 	flush_tlb_one((unsigned long)addr);
-
 	return addr;
 }
 EXPORT_SYMBOL(kmap);
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..c30bbb88fcfe 100644
--- a/arch/mips/include/asm/highmem.h
+++ b/arch/mips/include/asm/highmem.h
@@ -46,9 +46,9 @@ 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 * kmap_high(struct page *page);
 extern void kunmap_high(struct page *page);
 
+#define ARCH_HAS_KMAP
 extern void *kmap(struct page *page);
 extern void kunmap(struct page *page);
 extern void *kmap_atomic(struct page *page);
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index edd889f6cede..3867dbe9ef32 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -14,14 +14,9 @@ unsigned long highstart_pfn, highend_pfn;
 
 void *kmap(struct page *page)
 {
-	void *addr;
+	void *addr = kmap_generic(page);
 
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	addr = kmap_high(page);
 	flush_tlb_one((unsigned long)addr);
-
 	return addr;
 }
 EXPORT_SYMBOL(kmap);
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 413848cc1e56..fac4f48bde6c 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -63,7 +63,6 @@ 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)
@@ -73,10 +72,7 @@ static inline void *kmap(struct page *page)
 	 */
 	BUILD_BUG_ON(PKMAP_BASE <
 		     TLBTEMP_BASE_1 + TLBTEMP_SIZE);
-	might_sleep();
-	if (!PageHighMem(page))
-		return page_address(page);
-	return kmap_high(page);
+	return kmap_generic(page);
 }
 
 static inline void kunmap(struct page *page)
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index ea5cdbd8c2c3..2f7f710b7e7d 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -32,8 +32,26 @@ static inline void invalidate_kernel_vmap_range(void *vaddr, int size)
 #include <asm/kmap_types.h>
 
 #ifdef CONFIG_HIGHMEM
+extern void *kmap_high(struct page *page);
+
+/* kmap_generic: architecture independent portion of kmap calls */
+static inline void *kmap_generic(struct page *page)
+{
+	might_sleep();
+	if (!PageHighMem(page))
+		return page_address(page);
+	return kmap_high(page);
+}
+
 #include <asm/highmem.h>
 
+#ifndef ARCH_HAS_KMAP
+static inline void *kmap(struct page *page)
+{
+	return kmap_generic(page);
+}
+#endif
+
 /* declarations for linux/mm/highmem.c */
 unsigned int nr_free_highpages(void);
 extern atomic_long_t _totalhigh_pages;
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH 3/5] arch/kunmap: Remove duplicate kunmap implementations
  2020-04-26  5:54 [PATCH 0/5] Remove duplicated kmap code ira.weiny
  2020-04-26  5:54 ` [PATCH 1/5] arch/kmap: Remove BUG_ON() ira.weiny
  2020-04-26  5:54 ` [PATCH 2/5] arch/kmap: Remove redundant arch specific kmaps ira.weiny
@ 2020-04-26  5:54 ` ira.weiny
  2020-04-26  5:54 ` [PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code ira.weiny
  2020-04-26  5:54 ` [PATCH 5/5] arch/kunmap_atomic: " ira.weiny
  4 siblings, 0 replies; 11+ messages in thread
From: ira.weiny @ 2020-04-26  5:54 UTC (permalink / raw)
  To: linux-kernel, Andrew Morton
  Cc: Ira Weiny, Dan Williams, Thomas Bogendoerfer,
	James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
	Paul Mackerras, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, Dave Hansen,
	Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

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.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/arc/include/asm/highmem.h        |  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 |  8 --------
 arch/mips/include/asm/highmem.h       |  1 -
 arch/mips/mm/highmem.c                |  9 ---------
 arch/nds32/include/asm/highmem.h      |  1 -
 arch/nds32/mm/highmem.c               | 10 ----------
 arch/powerpc/include/asm/highmem.h    |  8 --------
 arch/sparc/include/asm/highmem.h      |  8 --------
 arch/x86/include/asm/highmem.h        |  2 --
 arch/x86/mm/highmem_32.c              |  9 ---------
 arch/xtensa/include/asm/highmem.h     |  8 --------
 include/linux/highmem.h               |  8 ++++++++
 16 files changed, 8 insertions(+), 93 deletions(-)

diff --git a/arch/arc/include/asm/highmem.h b/arch/arc/include/asm/highmem.h
index 96eb67c86961..c03a911c9f21 100644
--- a/arch/arc/include/asm/highmem.h
+++ b/arch/arc/include/asm/highmem.h
@@ -41,15 +41,6 @@ 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..829e3b969819 100644
--- a/arch/arm/include/asm/highmem.h
+++ b/arch/arm/include/asm/highmem.h
@@ -62,7 +62,6 @@ 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 4caeff143748..a0e7c43731a0 100644
--- a/arch/csky/include/asm/highmem.h
+++ b/arch/csky/include/asm/highmem.h
@@ -34,7 +34,6 @@ extern void kunmap_high(struct page *page);
 
 #define ARCH_HAS_KMAP
 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);
 extern void *kmap_atomic_pfn(unsigned long pfn);
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 5fb0bd855444..69b1931986ae 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -22,15 +22,6 @@ void *kmap(struct page *page)
 }
 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..1cbd52a0e39b 100644
--- a/arch/microblaze/include/asm/highmem.h
+++ b/arch/microblaze/include/asm/highmem.h
@@ -55,14 +55,6 @@ 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 c30bbb88fcfe..af9a66300628 100644
--- a/arch/mips/include/asm/highmem.h
+++ b/arch/mips/include/asm/highmem.h
@@ -50,7 +50,6 @@ extern void kunmap_high(struct page *page);
 
 #define ARCH_HAS_KMAP
 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);
 extern void *kmap_atomic_pfn(unsigned long pfn);
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index 3867dbe9ef32..c3c9fe962f0f 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -21,15 +21,6 @@ void *kmap(struct page *page)
 }
 EXPORT_SYMBOL(kmap);
 
-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..e455e2624247 100644
--- a/arch/nds32/include/asm/highmem.h
+++ b/arch/nds32/include/asm/highmem.h
@@ -53,7 +53,6 @@ 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..08e02a4f3a8f 100644
--- a/arch/powerpc/include/asm/highmem.h
+++ b/arch/powerpc/include/asm/highmem.h
@@ -63,14 +63,6 @@ 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..b3ee234b2a8f 100644
--- a/arch/sparc/include/asm/highmem.h
+++ b/arch/sparc/include/asm/highmem.h
@@ -52,14 +52,6 @@ void kmap_init(void) __init;
 
 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..102cdcde74cb 100644
--- a/arch/x86/include/asm/highmem.h
+++ b/arch/x86/include/asm/highmem.h
@@ -60,8 +60,6 @@ extern unsigned long highstart_pfn, highend_pfn;
 
 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 fac4f48bde6c..ae9e0ffbdb80 100644
--- a/arch/xtensa/include/asm/highmem.h
+++ b/arch/xtensa/include/asm/highmem.h
@@ -75,14 +75,6 @@ static inline void *kmap(struct page *page)
 	return kmap_generic(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 2f7f710b7e7d..1a3b7690c78c 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -52,6 +52,14 @@ static inline void *kmap(struct page *page)
 }
 #endif
 
+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


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code
  2020-04-26  5:54 [PATCH 0/5] Remove duplicated kmap code ira.weiny
                   ` (2 preceding siblings ...)
  2020-04-26  5:54 ` [PATCH 3/5] arch/kunmap: Remove duplicate kunmap implementations ira.weiny
@ 2020-04-26  5:54 ` ira.weiny
  2020-04-26  7:26   ` Christoph Hellwig
  2020-04-26  5:54 ` [PATCH 5/5] arch/kunmap_atomic: " ira.weiny
  4 siblings, 1 reply; 11+ messages in thread
From: ira.weiny @ 2020-04-26  5:54 UTC (permalink / raw)
  To: linux-kernel, Andrew Morton
  Cc: Ira Weiny, Dan Williams, Thomas Bogendoerfer,
	James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
	Paul Mackerras, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, Dave Hansen,
	Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

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

Every arch has the same check for a not HIGHMEM page.  Define
kmap_atomic_fast() to quickly return already mapped pages and reduce the
code duplication by lifting this check to the core.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/arc/mm/highmem.c        | 7 +++----
 arch/arm/mm/highmem.c        | 8 +++-----
 arch/csky/mm/highmem.c       | 7 +++----
 arch/microblaze/mm/highmem.c | 8 +++-----
 arch/mips/mm/highmem.c       | 7 +++----
 arch/nds32/mm/highmem.c      | 7 +++----
 arch/powerpc/mm/highmem.c    | 7 +++----
 arch/sparc/mm/highmem.c      | 7 +++----
 arch/x86/mm/highmem_32.c     | 8 +++-----
 arch/xtensa/mm/highmem.c     | 7 +++----
 include/linux/highmem.h      | 9 +++++++++
 11 files changed, 39 insertions(+), 43 deletions(-)

diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index 4db13a6b9f3b..1cae4b911a33 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -53,11 +53,10 @@ void *kmap_atomic(struct page *page)
 {
 	int idx, cpu_idx;
 	unsigned long vaddr;
+	void *addr = kmap_atomic_fast(page);
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
+	if (addr)
+		return addr;
 
 	cpu_idx = kmap_atomic_idx_push();
 	idx = cpu_idx + KM_TYPE_NR * smp_processor_id();
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index c700b32350ee..4a629f616a6a 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -35,13 +35,11 @@ void *kmap_atomic(struct page *page)
 {
 	unsigned int idx;
 	unsigned long vaddr;
-	void *kmap;
+	void *kmap = kmap_atomic_fast(page);
 	int type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
+	if (kmap)
+		return kmap;
 
 #ifdef CONFIG_DEBUG_HIGHMEM
 	/*
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 69b1931986ae..1191f57f53ae 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -25,12 +25,11 @@ EXPORT_SYMBOL(kmap);
 void *kmap_atomic(struct page *page)
 {
 	unsigned long vaddr;
+	void *addr = kmap_atomic_fast(page);
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
+	if (addr)
+		return addr;
 
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/microblaze/mm/highmem.c b/arch/microblaze/mm/highmem.c
index d7569f77fa15..99fdf826edc2 100644
--- a/arch/microblaze/mm/highmem.c
+++ b/arch/microblaze/mm/highmem.c
@@ -36,13 +36,11 @@ void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 {
 
 	unsigned long vaddr;
+	void *addr = kmap_atomic_fast(page);
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
-
+	if (addr)
+		return addr;
 
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index c3c9fe962f0f..ba03ca75d4a1 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -33,12 +33,11 @@ EXPORT_SYMBOL(kmap);
 void *kmap_atomic(struct page *page)
 {
 	unsigned long vaddr;
+	void *addr = kmap_atomic_fast(page);
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
+	if (addr)
+		return addr;
 
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index f9348bec0ecb..4aabde586489 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -14,13 +14,12 @@ void *kmap_atomic(struct page *page)
 {
 	unsigned int idx;
 	unsigned long vaddr, pte;
+	void *addr = kmap_atomic_fast(page);
 	int type;
 	pte_t *ptep;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
+	if (addr)
+		return addr;
 
 	type = kmap_atomic_idx_push();
 
diff --git a/arch/powerpc/mm/highmem.c b/arch/powerpc/mm/highmem.c
index 320c1672b2ae..cdf5b716801a 100644
--- a/arch/powerpc/mm/highmem.c
+++ b/arch/powerpc/mm/highmem.c
@@ -33,12 +33,11 @@
 void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 {
 	unsigned long vaddr;
+	void *addr = kmap_atomic_fast(page);
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
+	if (addr)
+		return addr;
 
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c
index d4a80adea7e5..178641805567 100644
--- a/arch/sparc/mm/highmem.c
+++ b/arch/sparc/mm/highmem.c
@@ -56,12 +56,11 @@ void __init kmap_init(void)
 void *kmap_atomic(struct page *page)
 {
 	unsigned long vaddr;
+	void *addr = kmap_atomic_fast(page);
 	long idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
+	if (addr)
+		return addr;
 
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index c4ebfd0ae401..34770499b0ff 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -15,13 +15,11 @@
 void *kmap_atomic_prot(struct page *page, pgprot_t prot)
 {
 	unsigned long vaddr;
+	void *addr = kmap_atomic_fast(page);
 	int idx, type;
 
-	preempt_disable();
-	pagefault_disable();
-
-	if (!PageHighMem(page))
-		return page_address(page);
+	if (addr)
+		return addr;
 
 	type = kmap_atomic_idx_push();
 	idx = type + KM_TYPE_NR*smp_processor_id();
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index 184ceadccc1a..38c14e0b578c 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -41,11 +41,10 @@ void *kmap_atomic(struct page *page)
 {
 	enum fixed_addresses idx;
 	unsigned long vaddr;
+	void *addr = kmap_atomic_fast(page);
 
-	preempt_disable();
-	pagefault_disable();
-	if (!PageHighMem(page))
-		return page_address(page);
+	if (addr)
+		return addr;
 
 	idx = kmap_idx(kmap_atomic_idx_push(),
 		       DCACHE_ALIAS(page_to_phys(page)));
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index 1a3b7690c78c..eee53e151900 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -60,6 +60,15 @@ static inline void kunmap(struct page *page)
 	kunmap_high(page);
 }
 
+static inline void *kmap_atomic_fast(struct page *page)
+{
+	preempt_disable();
+	pagefault_disable();
+	if (!PageHighMem(page))
+		return page_address(page);
+	return NULL;
+}
+
 /* declarations for linux/mm/highmem.c */
 unsigned int nr_free_highpages(void);
 extern atomic_long_t _totalhigh_pages;
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* [PATCH 5/5] arch/kunmap_atomic: Consolidate duplicate code
  2020-04-26  5:54 [PATCH 0/5] Remove duplicated kmap code ira.weiny
                   ` (3 preceding siblings ...)
  2020-04-26  5:54 ` [PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code ira.weiny
@ 2020-04-26  5:54 ` ira.weiny
  4 siblings, 0 replies; 11+ messages in thread
From: ira.weiny @ 2020-04-26  5:54 UTC (permalink / raw)
  To: linux-kernel, Andrew Morton
  Cc: Ira Weiny, Dan Williams, Thomas Bogendoerfer,
	James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
	Paul Mackerras, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, Dave Hansen,
	Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

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.

Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Ira Weiny <ira.weiny@intel.com>
---
 arch/arc/mm/highmem.c                | 3 ---
 arch/arm/mm/highmem.c                | 2 --
 arch/csky/mm/highmem.c               | 5 +----
 arch/microblaze/mm/highmem.c         | 2 --
 arch/mips/mm/highmem.c               | 2 --
 arch/nds32/mm/highmem.c              | 2 --
 arch/parisc/include/asm/cacheflush.h | 2 --
 arch/powerpc/mm/highmem.c            | 2 --
 arch/sparc/mm/highmem.c              | 2 --
 arch/x86/mm/highmem_32.c             | 3 ---
 arch/xtensa/mm/highmem.c             | 3 ---
 include/linux/highmem.h              | 6 ++++--
 12 files changed, 5 insertions(+), 29 deletions(-)

diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
index 1cae4b911a33..0725fc56b016 100644
--- a/arch/arc/mm/highmem.c
+++ b/arch/arc/mm/highmem.c
@@ -91,9 +91,6 @@ void __kunmap_atomic(void *kv)
 
 		kmap_atomic_idx_pop();
 	}
-
-	pagefault_enable();
-	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
diff --git a/arch/arm/mm/highmem.c b/arch/arm/mm/highmem.c
index 4a629f616a6a..4983bf18ec32 100644
--- a/arch/arm/mm/highmem.c
+++ b/arch/arm/mm/highmem.c
@@ -98,8 +98,6 @@ 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);
 
diff --git a/arch/csky/mm/highmem.c b/arch/csky/mm/highmem.c
index 1191f57f53ae..106fa6773084 100644
--- a/arch/csky/mm/highmem.c
+++ b/arch/csky/mm/highmem.c
@@ -50,7 +50,7 @@ void __kunmap_atomic(void *kvaddr)
 	int idx;
 
 	if (vaddr < FIXADDR_START)
-		goto out;
+		return;
 
 #ifdef CONFIG_DEBUG_HIGHMEM
 	idx = KM_TYPE_NR*smp_processor_id() + kmap_atomic_idx();
@@ -63,9 +63,6 @@ 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);
 
diff --git a/arch/microblaze/mm/highmem.c b/arch/microblaze/mm/highmem.c
index 99fdf826edc2..d382c6821747 100644
--- a/arch/microblaze/mm/highmem.c
+++ b/arch/microblaze/mm/highmem.c
@@ -81,7 +81,5 @@ void __kunmap_atomic(void *kvaddr)
 	local_flush_tlb_page(NULL, vaddr);
 
 	kmap_atomic_idx_pop();
-	pagefault_enable();
-	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
diff --git a/arch/mips/mm/highmem.c b/arch/mips/mm/highmem.c
index ba03ca75d4a1..5a3fc7e84e66 100644
--- a/arch/mips/mm/highmem.c
+++ b/arch/mips/mm/highmem.c
@@ -79,8 +79,6 @@ void __kunmap_atomic(void *kvaddr)
 	}
 #endif
 	kmap_atomic_idx_pop();
-	pagefault_enable();
-	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
diff --git a/arch/nds32/mm/highmem.c b/arch/nds32/mm/highmem.c
index 4aabde586489..b8862aafa189 100644
--- a/arch/nds32/mm/highmem.c
+++ b/arch/nds32/mm/highmem.c
@@ -49,8 +49,6 @@ 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);
diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index 0c83644bfa5c..c8458491b9af 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/arch/parisc/include/asm/cacheflush.h
@@ -125,8 +125,6 @@ static inline void *kmap_atomic(struct page *page)
 static inline void __kunmap_atomic(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/mm/highmem.c b/arch/powerpc/mm/highmem.c
index cdf5b716801a..7dfccf519621 100644
--- a/arch/powerpc/mm/highmem.c
+++ b/arch/powerpc/mm/highmem.c
@@ -76,7 +76,5 @@ void __kunmap_atomic(void *kvaddr)
 	}
 
 	kmap_atomic_idx_pop();
-	pagefault_enable();
-	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
diff --git a/arch/sparc/mm/highmem.c b/arch/sparc/mm/highmem.c
index 178641805567..7a99a1097f67 100644
--- a/arch/sparc/mm/highmem.c
+++ b/arch/sparc/mm/highmem.c
@@ -130,7 +130,5 @@ void __kunmap_atomic(void *kvaddr)
 #endif
 
 	kmap_atomic_idx_pop();
-	pagefault_enable();
-	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
diff --git a/arch/x86/mm/highmem_32.c b/arch/x86/mm/highmem_32.c
index 34770499b0ff..b20e81b2b833 100644
--- a/arch/x86/mm/highmem_32.c
+++ b/arch/x86/mm/highmem_32.c
@@ -78,9 +78,6 @@ void __kunmap_atomic(void *kvaddr)
 		BUG_ON(vaddr >= (unsigned long)high_memory);
 	}
 #endif
-
-	pagefault_enable();
-	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
diff --git a/arch/xtensa/mm/highmem.c b/arch/xtensa/mm/highmem.c
index 38c14e0b578c..9a49263e4cd6 100644
--- a/arch/xtensa/mm/highmem.c
+++ b/arch/xtensa/mm/highmem.c
@@ -77,9 +77,6 @@ void __kunmap_atomic(void *kvaddr)
 
 		kmap_atomic_idx_pop();
 	}
-
-	pagefault_enable();
-	preempt_enable();
 }
 EXPORT_SYMBOL(__kunmap_atomic);
 
diff --git a/include/linux/highmem.h b/include/linux/highmem.h
index eee53e151900..94145d4200ab 100644
--- a/include/linux/highmem.h
+++ b/include/linux/highmem.h
@@ -133,8 +133,8 @@ static inline void *kmap_atomic(struct page *page)
 
 static inline void __kunmap_atomic(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))
@@ -185,6 +185,8 @@ static inline void kmap_atomic_idx_pop(void)
 do {                                                            \
 	BUILD_BUG_ON(__same_type((addr), struct page *));       \
 	__kunmap_atomic(addr);                                  \
+	pagefault_enable();                                     \
+	preempt_enable();                                       \
 } while (0)
 
 
-- 
2.25.1


^ permalink raw reply related	[flat|nested] 11+ messages in thread

* Re: [PATCH 2/5] arch/kmap: Remove redundant arch specific kmaps
  2020-04-26  5:54 ` [PATCH 2/5] arch/kmap: Remove redundant arch specific kmaps ira.weiny
@ 2020-04-26  7:17   ` Christoph Hellwig
  2020-04-26 22:23     ` Ira Weiny
  0 siblings, 1 reply; 11+ messages in thread
From: Christoph Hellwig @ 2020-04-26  7:17 UTC (permalink / raw)
  To: ira.weiny
  Cc: linux-kernel, Andrew Morton, Dan Williams, Thomas Bogendoerfer,
	James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
	Paul Mackerras, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, Dave Hansen,
	Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

On Sat, Apr 25, 2020 at 10:54:03PM -0700, ira.weiny@intel.com wrote:
> 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 to indicate if an
> arch needs a special kmap.

Can you add a kmap_flush_tlb hook that csky and mips define, and the
just entirely consolidate the code instead?

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code
  2020-04-26  5:54 ` [PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code ira.weiny
@ 2020-04-26  7:26   ` Christoph Hellwig
  2020-04-27  1:16     ` Ira Weiny
  0 siblings, 1 reply; 11+ messages in thread
From: Christoph Hellwig @ 2020-04-26  7:26 UTC (permalink / raw)
  To: ira.weiny
  Cc: linux-kernel, Andrew Morton, Dan Williams, Thomas Bogendoerfer,
	James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
	Paul Mackerras, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, Dave Hansen,
	Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

> diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
> index 4db13a6b9f3b..1cae4b911a33 100644
> --- a/arch/arc/mm/highmem.c
> +++ b/arch/arc/mm/highmem.c
> @@ -53,11 +53,10 @@ void *kmap_atomic(struct page *page)
>  {
>  	int idx, cpu_idx;
>  	unsigned long vaddr;
> +	void *addr = kmap_atomic_fast(page);
>  
> -	preempt_disable();
> -	pagefault_disable();
> -	if (!PageHighMem(page))
> -		return page_address(page);
> +	if (addr)
> +		return addr;

Wouldn't it make sense to just move kmap_atomic itelf to common code,
and call out to a kmap_atomic_high for the highmem case, following the
scheme in kmap?  Same for the unmap side.  That might require to support
kmap_atomic_prot everywhere first, which sounds like a really good
idea anyway, and would avoid the need for strange workaround in drm.

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 2/5] arch/kmap: Remove redundant arch specific kmaps
  2020-04-26  7:17   ` Christoph Hellwig
@ 2020-04-26 22:23     ` Ira Weiny
  0 siblings, 0 replies; 11+ messages in thread
From: Ira Weiny @ 2020-04-26 22:23 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: linux-kernel, Andrew Morton, Dan Williams, Thomas Bogendoerfer,
	James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
	Paul Mackerras, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, Dave Hansen,
	Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

On Sun, Apr 26, 2020 at 12:17:15AM -0700, Christoph Hellwig wrote:
> On Sat, Apr 25, 2020 at 10:54:03PM -0700, ira.weiny@intel.com wrote:
> > 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 to indicate if an
> > arch needs a special kmap.
> 
> Can you add a kmap_flush_tlb hook that csky and mips define, and the
> just entirely consolidate the code instead?

Sure that seems to work.

Ira

^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code
  2020-04-26  7:26   ` Christoph Hellwig
@ 2020-04-27  1:16     ` Ira Weiny
  2020-04-27  6:25       ` Christoph Hellwig
  0 siblings, 1 reply; 11+ messages in thread
From: Ira Weiny @ 2020-04-27  1:16 UTC (permalink / raw)
  To: Christoph Hellwig
  Cc: linux-kernel, Andrew Morton, Dan Williams, Thomas Bogendoerfer,
	James E.J. Bottomley, Helge Deller, Benjamin Herrenschmidt,
	Paul Mackerras, David S. Miller, Thomas Gleixner, Ingo Molnar,
	Borislav Petkov, x86, H. Peter Anvin, Dave Hansen,
	Andy Lutomirski, Peter Zijlstra, Chris Zankel, Max Filippov,
	linux-snps-arc, linux-arm-kernel, linux-csky, linux-mips,
	linux-parisc, linuxppc-dev, sparclinux, linux-xtensa

On Sun, Apr 26, 2020 at 12:26:42AM -0700, Christoph Hellwig wrote:
> > diff --git a/arch/arc/mm/highmem.c b/arch/arc/mm/highmem.c
> > index 4db13a6b9f3b..1cae4b911a33 100644
> > --- a/arch/arc/mm/highmem.c
> > +++ b/arch/arc/mm/highmem.c
> > @@ -53,11 +53,10 @@ void *kmap_atomic(struct page *page)
> >  {
> >  	int idx, cpu_idx;
> >  	unsigned long vaddr;
> > +	void *addr = kmap_atomic_fast(page);
> >  
> > -	preempt_disable();
> > -	pagefault_disable();
> > -	if (!PageHighMem(page))
> > -		return page_address(page);
> > +	if (addr)
> > +		return addr;
> 
> Wouldn't it make sense to just move kmap_atomic itelf to common code,
> and call out to a kmap_atomic_high for the highmem case, following the
> scheme in kmap?
>

Sure I do like that symmetry between the calls.

>
> Same for the unmap side.

FWIW that would simply be renaming  __kunmap_atomic() to kunmap_atomic_high()

>
> That might require to support
> kmap_atomic_prot everywhere first, which sounds like a really good
> idea anyway, and would avoid the need for strange workaround in drm.

Having a kmap_atomic_prot() seems like a good idea.  But I'm not exactly sure
why CONFIG_x86 is being called out specifically in the DRM code?

Ira


^ permalink raw reply	[flat|nested] 11+ messages in thread

* Re: [PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code
  2020-04-27  1:16     ` Ira Weiny
@ 2020-04-27  6:25       ` Christoph Hellwig
  0 siblings, 0 replies; 11+ messages in thread
From: Christoph Hellwig @ 2020-04-27  6:25 UTC (permalink / raw)
  To: Ira Weiny
  Cc: Christoph Hellwig, linux-kernel, Andrew Morton, Dan Williams,
	Thomas Bogendoerfer, James E.J. Bottomley, Helge Deller,
	Benjamin Herrenschmidt, Paul Mackerras, David S. Miller,
	Thomas Gleixner, Ingo Molnar, Borislav Petkov, x86,
	H. Peter Anvin, Dave Hansen, Andy Lutomirski, Peter Zijlstra,
	Chris Zankel, Max Filippov, linux-snps-arc, linux-arm-kernel,
	linux-csky, linux-mips, linux-parisc, linuxppc-dev, sparclinux,
	linux-xtensa

On Sun, Apr 26, 2020 at 06:16:30PM -0700, Ira Weiny wrote:
> > That might require to support
> > kmap_atomic_prot everywhere first, which sounds like a really good
> > idea anyway, and would avoid the need for strange workaround in drm.
> 
> Having a kmap_atomic_prot() seems like a good idea.  But I'm not exactly sure
> why CONFIG_x86 is being called out specifically in the DRM code?

Probably because it only existed on x86 back then.  And drm has a
tendency of working around core problems with hacks instead of doing
the fairly easy fixups.

^ permalink raw reply	[flat|nested] 11+ messages in thread

end of thread, other threads:[~2020-04-27  6:25 UTC | newest]

Thread overview: 11+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-04-26  5:54 [PATCH 0/5] Remove duplicated kmap code ira.weiny
2020-04-26  5:54 ` [PATCH 1/5] arch/kmap: Remove BUG_ON() ira.weiny
2020-04-26  5:54 ` [PATCH 2/5] arch/kmap: Remove redundant arch specific kmaps ira.weiny
2020-04-26  7:17   ` Christoph Hellwig
2020-04-26 22:23     ` Ira Weiny
2020-04-26  5:54 ` [PATCH 3/5] arch/kunmap: Remove duplicate kunmap implementations ira.weiny
2020-04-26  5:54 ` [PATCH 4/5] arch/kmap_atomic: Consolidate duplicate code ira.weiny
2020-04-26  7:26   ` Christoph Hellwig
2020-04-27  1:16     ` Ira Weiny
2020-04-27  6:25       ` Christoph Hellwig
2020-04-26  5:54 ` [PATCH 5/5] arch/kunmap_atomic: " ira.weiny

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