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

ira.weiny
2020-05-04T01:09:51Z

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