block: add helpers to run flush_dcache_page() against a bio and a request's pages

Mtdblock driver doesn't call flush_dcache_page for pages in request.  So,
this causes problems on architectures where the icache doesn't fill from
the dcache or with dcache aliases.  The patch fixes this.

The ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE symbol was introduced to avoid
pointless empty cache-thrashing loops on architectures for which
flush_dcache_page() is a no-op.  Every architecture was provided with this
flush pages on architectires where ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE is
equal 1 or do nothing otherwise.

See "fix mtd_blkdevs problem with caches on some architectures" discussion
on LKML for more information.

Signed-off-by: Ilya Loginov <isloginov@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Peter Horton <phorton@bitbox.co.uk>
Cc: "Ed L. Cashin" <ecashin@coraid.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

arch/alpha/include/asm/cacheflush.h

@@ -9,6 +9,7 @@
 #define flush_cache_dup_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr, pfn)	do { } while (0)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)

arch/arm/include/asm/cacheflush.h

@@ -408,6 +408,7 @@ extern void flush_ptrace_access(struct vm_area_struct *vma, struct page *page,
  * about to change to user space.  This is the same method as used on SPARC64.
  * See update_mmu_cache for the user space part.
  */
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 extern void flush_dcache_page(struct page *);
 
 extern void __flush_dcache_page(struct address_space *mapping, struct page *page);

arch/avr32/include/asm/cacheflush.h

@@ -107,6 +107,7 @@ extern void flush_icache_page(struct vm_area_struct *vma, struct page *page);
  * do something here, but only for certain configurations.  No such
  * configurations exist at this time.
  */
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_dcache_mmap_lock(page)		do { } while (0)
 #define flush_dcache_mmap_unlock(page)		do { } while (0)

arch/blackfin/include/asm/cacheflush.h

@@ -68,9 +68,11 @@ do { memcpy(dst, src, len);						\
 #endif
 #if defined(CONFIG_BFIN_EXTMEM_WRITEBACK) || defined(CONFIG_BFIN_L2_WRITEBACK)
 # define flush_dcache_range(start,end)		blackfin_dcache_flush_range((start), (end))
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 # define flush_dcache_page(page)		blackfin_dflush_page(page_address(page))
 #else
 # define flush_dcache_range(start,end)		do { } while (0)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 # define flush_dcache_page(page)		do { } while (0)
 #endif
 

arch/cris/include/asm/cacheflush.h

@@ -12,6 +12,7 @@
 #define flush_cache_dup_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr, pfn)	do { } while (0)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)

arch/frv/include/asm/cacheflush.h

@@ -47,6 +47,7 @@ static inline void __flush_cache_all(void)
 }
 
 /* dcache/icache coherency... */
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 #ifdef CONFIG_MMU
 extern void flush_dcache_page(struct page *page);
 #else

arch/h8300/include/asm/cacheflush.h

@@ -15,6 +15,7 @@
 #define	flush_cache_dup_mm(mm)		do { } while (0)
 #define	flush_cache_range(vma,a,b)
 #define	flush_cache_page(vma,p,pfn)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define	flush_dcache_page(page)
 #define	flush_dcache_mmap_lock(mapping)
 #define	flush_dcache_mmap_unlock(mapping)

arch/ia64/include/asm/cacheflush.h

@@ -25,6 +25,7 @@
 #define flush_cache_vmap(start, end)		do { } while (0)
 #define flush_cache_vunmap(start, end)		do { } while (0)
 
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 #define flush_dcache_page(page)			\
 do {						\
 	clear_bit(PG_arch_1, &(page)->flags);	\

arch/m32r/include/asm/cacheflush.h

@@ -12,6 +12,7 @@ extern void _flush_cache_copyback_all(void);
 #define flush_cache_dup_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr, pfn)	do { } while (0)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)
@@ -33,6 +34,7 @@ extern void smp_flush_cache_all(void);
 #define flush_cache_dup_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr, pfn)	do { } while (0)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)
@@ -46,6 +48,7 @@ extern void smp_flush_cache_all(void);
 #define flush_cache_dup_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr, pfn)	do { } while (0)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)

arch/m68k/include/asm/cacheflush_mm.h

@@ -128,6 +128,7 @@ static inline void __flush_page_to_ram(void *vaddr)
 	}
 }
 
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 #define flush_dcache_page(page)		__flush_page_to_ram(page_address(page))
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)

arch/m68k/include/asm/cacheflush_no.h

@@ -12,6 +12,7 @@
 #define flush_cache_range(vma, start, end)	__flush_cache_all()
 #define flush_cache_page(vma, vmaddr)		do { } while (0)
 #define flush_dcache_range(start,len)		__flush_cache_all()
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)

arch/microblaze/include/asm/cacheflush.h

@@ -37,6 +37,7 @@
 #define flush_cache_page(vma, vmaddr, pfn)	do { } while (0)
 
 #define flush_dcache_range(start, end)	__invalidate_dcache_range(start, end)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)

arch/mips/include/asm/cacheflush.h

@@ -38,6 +38,7 @@ extern void (*flush_cache_range)(struct vm_area_struct *vma,
 extern void (*flush_cache_page)(struct vm_area_struct *vma, unsigned long page, unsigned long pfn);
 extern void __flush_dcache_page(struct page *page);
 
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 static inline void flush_dcache_page(struct page *page)
 {
 	if (cpu_has_dc_aliases || !cpu_has_ic_fills_f_dc)

arch/mn10300/include/asm/cacheflush.h

@@ -26,6 +26,7 @@
 #define flush_cache_page(vma, vmaddr, pfn)	do {} while (0)
 #define flush_cache_vmap(start, end)		do {} while (0)
 #define flush_cache_vunmap(start, end)		do {} while (0)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do {} while (0)
 #define flush_dcache_mmap_lock(mapping)		do {} while (0)
 #define flush_dcache_mmap_unlock(mapping)	do {} while (0)

arch/parisc/include/asm/cacheflush.h

@@ -42,6 +42,7 @@ void flush_cache_mm(struct mm_struct *mm);
 #define flush_cache_vmap(start, end)		flush_cache_all()
 #define flush_cache_vunmap(start, end)		flush_cache_all()
 
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 extern void flush_dcache_page(struct page *page);
 
 #define flush_dcache_mmap_lock(mapping) \

arch/powerpc/include/asm/cacheflush.h

@@ -25,6 +25,7 @@
 #define flush_cache_vmap(start, end)		do { } while (0)
 #define flush_cache_vunmap(start, end)		do { } while (0)
 
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 extern void flush_dcache_page(struct page *page);
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)

arch/s390/include/asm/cacheflush.h

@@ -10,6 +10,7 @@
 #define flush_cache_dup_mm(mm)			do { } while (0)
 #define flush_cache_range(vma, start, end)	do { } while (0)
 #define flush_cache_page(vma, vmaddr, pfn)	do { } while (0)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do { } while (0)
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)

arch/score/include/asm/cacheflush.h

@@ -16,6 +16,7 @@ extern void flush_icache_range(unsigned long start, unsigned long end);
 extern void flush_dcache_range(unsigned long start, unsigned long end);
 
 #define flush_cache_dup_mm(mm)			do {} while (0)
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
 #define flush_dcache_page(page)			do {} while (0)
 #define flush_dcache_mmap_lock(mapping)		do {} while (0)
 #define flush_dcache_mmap_unlock(mapping)	do {} while (0)

arch/sh/include/asm/cacheflush.h

@@ -42,6 +42,7 @@ extern void flush_cache_page(struct vm_area_struct *vma,
 				unsigned long addr, unsigned long pfn);
 extern void flush_cache_range(struct vm_area_struct *vma,
 				 unsigned long start, unsigned long end);
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 extern void flush_dcache_page(struct page *page);
 extern void flush_icache_range(unsigned long start, unsigned long end);
 extern void flush_icache_page(struct vm_area_struct *vma,

arch/sparc/include/asm/cacheflush_32.h

@@ -75,6 +75,7 @@ BTFIXUPDEF_CALL(void, flush_sig_insns, struct mm_struct *, unsigned long)
 
 extern void sparc_flush_page_to_ram(struct page *page);
 
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
 #define flush_dcache_page(page)			sparc_flush_page_to_ram(page)
 #define flush_dcache_mmap_lock(mapping)		do { } while (0)
 #define flush_dcache_mmap_unlock(mapping)	do { } while (0)