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authorIlya Loginov <isloginov@gmail.com>2009-11-26 09:16:19 +0100
committerJens Axboe <jens.axboe@oracle.com>2009-11-26 09:16:19 +0100
commit2d4dc890b5c8fabd818a8586607e6843c4375e62 (patch)
tree9976ed7b0eed0056f8289aeb6a2b0abf8c940454
parent3586e917f2c7df769d173c4ec99554cb40a911e5 (diff)
downloadlinux-2d4dc890b5c8fabd818a8586607e6843c4375e62.tar.bz2
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>
-rw-r--r--arch/alpha/include/asm/cacheflush.h1
-rw-r--r--arch/arm/include/asm/cacheflush.h1
-rw-r--r--arch/avr32/include/asm/cacheflush.h1
-rw-r--r--arch/blackfin/include/asm/cacheflush.h2
-rw-r--r--arch/cris/include/asm/cacheflush.h1
-rw-r--r--arch/frv/include/asm/cacheflush.h1
-rw-r--r--arch/h8300/include/asm/cacheflush.h1
-rw-r--r--arch/ia64/include/asm/cacheflush.h1
-rw-r--r--arch/m32r/include/asm/cacheflush.h3
-rw-r--r--arch/m68k/include/asm/cacheflush_mm.h1
-rw-r--r--arch/m68k/include/asm/cacheflush_no.h1
-rw-r--r--arch/microblaze/include/asm/cacheflush.h1
-rw-r--r--arch/mips/include/asm/cacheflush.h1
-rw-r--r--arch/mn10300/include/asm/cacheflush.h1
-rw-r--r--arch/parisc/include/asm/cacheflush.h1
-rw-r--r--arch/powerpc/include/asm/cacheflush.h1
-rw-r--r--arch/s390/include/asm/cacheflush.h1
-rw-r--r--arch/score/include/asm/cacheflush.h1
-rw-r--r--arch/sh/include/asm/cacheflush.h1
-rw-r--r--arch/sparc/include/asm/cacheflush_32.h1
-rw-r--r--arch/sparc/include/asm/cacheflush_64.h1
-rw-r--r--arch/x86/include/asm/cacheflush.h1
-rw-r--r--arch/xtensa/include/asm/cacheflush.h1
-rw-r--r--block/blk-core.c19
-rw-r--r--drivers/mtd/mtd_blkdevs.c2
-rw-r--r--fs/bio.c12
-rw-r--r--include/asm-generic/cacheflush.h1
-rw-r--r--include/linux/bio.h12
-rw-r--r--include/linux/blkdev.h11
29 files changed, 83 insertions, 0 deletions
diff --git a/arch/alpha/include/asm/cacheflush.h b/arch/alpha/include/asm/cacheflush.h
index b686cc7fc44e..01d71e1c8a9e 100644
--- a/arch/alpha/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/arm/include/asm/cacheflush.h b/arch/arm/include/asm/cacheflush.h
index fd03fb63a332..247b7b0adc2a 100644
--- a/arch/arm/include/asm/cacheflush.h
+++ b/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);
diff --git a/arch/avr32/include/asm/cacheflush.h b/arch/avr32/include/asm/cacheflush.h
index 670674749b20..96e53820bbbd 100644
--- a/arch/avr32/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/blackfin/include/asm/cacheflush.h b/arch/blackfin/include/asm/cacheflush.h
index af03a36c7a4e..417eaac7fe99 100644
--- a/arch/blackfin/include/asm/cacheflush.h
+++ b/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
diff --git a/arch/cris/include/asm/cacheflush.h b/arch/cris/include/asm/cacheflush.h
index cf60e3f69f8d..36795bca605e 100644
--- a/arch/cris/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/frv/include/asm/cacheflush.h b/arch/frv/include/asm/cacheflush.h
index 432a69e7f3d4..edbac54ae015 100644
--- a/arch/frv/include/asm/cacheflush.h
+++ b/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
diff --git a/arch/h8300/include/asm/cacheflush.h b/arch/h8300/include/asm/cacheflush.h
index 5ffdca217b95..4cf2df20c1ce 100644
--- a/arch/h8300/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/ia64/include/asm/cacheflush.h b/arch/ia64/include/asm/cacheflush.h
index c8ce2719fee8..429eefc93ee7 100644
--- a/arch/ia64/include/asm/cacheflush.h
+++ b/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); \
diff --git a/arch/m32r/include/asm/cacheflush.h b/arch/m32r/include/asm/cacheflush.h
index 78587c958146..8e8e04516c39 100644
--- a/arch/m32r/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/m68k/include/asm/cacheflush_mm.h b/arch/m68k/include/asm/cacheflush_mm.h
index 16bf375fdbe1..73de7c89d8e0 100644
--- a/arch/m68k/include/asm/cacheflush_mm.h
+++ b/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)
diff --git a/arch/m68k/include/asm/cacheflush_no.h b/arch/m68k/include/asm/cacheflush_no.h
index c65f00a94553..89f195656be7 100644
--- a/arch/m68k/include/asm/cacheflush_no.h
+++ b/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)
diff --git a/arch/microblaze/include/asm/cacheflush.h b/arch/microblaze/include/asm/cacheflush.h
index f989d6aad648..088076e657b3 100644
--- a/arch/microblaze/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/mips/include/asm/cacheflush.h b/arch/mips/include/asm/cacheflush.h
index 03b1d69b142f..40bb9fde205f 100644
--- a/arch/mips/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/mn10300/include/asm/cacheflush.h b/arch/mn10300/include/asm/cacheflush.h
index 1a55d61f0d06..29e692f7f030 100644
--- a/arch/mn10300/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/parisc/include/asm/cacheflush.h b/arch/parisc/include/asm/cacheflush.h
index 724395143f26..7a73b615c23d 100644
--- a/arch/parisc/include/asm/cacheflush.h
+++ b/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) \
diff --git a/arch/powerpc/include/asm/cacheflush.h b/arch/powerpc/include/asm/cacheflush.h
index ba667a383b8c..ab9e402518e8 100644
--- a/arch/powerpc/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/s390/include/asm/cacheflush.h b/arch/s390/include/asm/cacheflush.h
index 49d5af916d01..405cc97c6249 100644
--- a/arch/s390/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/score/include/asm/cacheflush.h b/arch/score/include/asm/cacheflush.h
index 07cc8fc457cd..caaba24036e3 100644
--- a/arch/score/include/asm/cacheflush.h
+++ b/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)
diff --git a/arch/sh/include/asm/cacheflush.h b/arch/sh/include/asm/cacheflush.h
index c29918f3c819..dda96eb3e7c0 100644
--- a/arch/sh/include/asm/cacheflush.h
+++ b/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,
diff --git a/arch/sparc/include/asm/cacheflush_32.h b/arch/sparc/include/asm/cacheflush_32.h
index 68ac10910271..2e468773f250 100644
--- a/arch/sparc/include/asm/cacheflush_32.h
+++ b/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)
diff --git a/arch/sparc/include/asm/cacheflush_64.h b/arch/sparc/include/asm/cacheflush_64.h
index c43321729b3b..b95384033e89 100644
--- a/arch/sparc/include/asm/cacheflush_64.h
+++ b/arch/sparc/include/asm/cacheflush_64.h
@@ -37,6 +37,7 @@ extern void flush_dcache_page_all(struct mm_struct *mm, struct page *page);
#endif
extern void __flush_dcache_range(unsigned long start, unsigned long end);
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 1
extern void flush_dcache_page(struct page *page);
#define flush_icache_page(vma, pg) do { } while(0)
diff --git a/arch/x86/include/asm/cacheflush.h b/arch/x86/include/asm/cacheflush.h
index b54f6afe7ec4..9076add593a8 100644
--- a/arch/x86/include/asm/cacheflush.h
+++ b/arch/x86/include/asm/cacheflush.h
@@ -12,6 +12,7 @@ static inline void flush_cache_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end) { }
static inline void flush_cache_page(struct vm_area_struct *vma,
unsigned long vmaddr, unsigned long pfn) { }
+#define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE 0
static inline void flush_dcache_page(struct page *page) { }
static inline void flush_dcache_mmap_lock(struct address_space *mapping) { }
static inline void flush_dcache_mmap_unlock(struct address_space *mapping) { }
diff --git a/arch/xtensa/include/asm/cacheflush.h b/arch/xtensa/include/asm/cacheflush.h
index b7b8fbe47c77..a508f2f73bd7 100644
--- a/arch/xtensa/include/asm/cacheflush.h
+++ b/arch/xtensa/include/asm/cacheflush.h
@@ -101,6 +101,7 @@ static inline void __invalidate_icache_page_alias(unsigned long virt,
#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*);
extern void flush_cache_range(struct vm_area_struct*, ulong, ulong);
extern void flush_cache_page(struct vm_area_struct*, unsigned long, unsigned long);
diff --git a/block/blk-core.c b/block/blk-core.c
index 71da5111120c..718897e6d37f 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -2358,6 +2358,25 @@ void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
rq->rq_disk = bio->bi_bdev->bd_disk;
}
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+/**
+ * rq_flush_dcache_pages - Helper function to flush all pages in a request
+ * @rq: the request to be flushed
+ *
+ * Description:
+ * Flush all pages in @rq.
+ */
+void rq_flush_dcache_pages(struct request *rq)
+{
+ struct req_iterator iter;
+ struct bio_vec *bvec;
+
+ rq_for_each_segment(bvec, rq, iter)
+ flush_dcache_page(bvec->bv_page);
+}
+EXPORT_SYMBOL_GPL(rq_flush_dcache_pages);
+#endif
+
/**
* blk_lld_busy - Check if underlying low-level drivers of a device are busy
* @q : the queue of the device being checked
diff --git a/drivers/mtd/mtd_blkdevs.c b/drivers/mtd/mtd_blkdevs.c
index 8ca17a3e96ea..64e2b379a350 100644
--- a/drivers/mtd/mtd_blkdevs.c
+++ b/drivers/mtd/mtd_blkdevs.c
@@ -59,12 +59,14 @@ static int do_blktrans_request(struct mtd_blktrans_ops *tr,
for (; nsect > 0; nsect--, block++, buf += tr->blksize)
if (tr->readsect(dev, block, buf))
return -EIO;
+ rq_flush_dcache_pages(req);
return 0;
case WRITE:
if (!tr->writesect)
return -EIO;
+ rq_flush_dcache_pages(req);
for (; nsect > 0; nsect--, block++, buf += tr->blksize)
if (tr->writesect(dev, block, buf))
return -EIO;
diff --git a/fs/bio.c b/fs/bio.c
index 12da5db8682c..e23a63f4f7de 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -1393,6 +1393,18 @@ void bio_check_pages_dirty(struct bio *bio)
}
}
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+void bio_flush_dcache_pages(struct bio *bi)
+{
+ int i;
+ struct bio_vec *bvec;
+
+ bio_for_each_segment(bvec, bi, i)
+ flush_dcache_page(bvec->bv_page);
+}
+EXPORT_SYMBOL(bio_flush_dcache_pages);
+#endif
+
/**
* bio_endio - end I/O on a bio
* @bio: bio
diff --git a/include/asm-generic/cacheflush.h b/include/asm-generic/cacheflush.h
index ba4ec39a1131..57b5c3c82e86 100644
--- a/include/asm-generic/cacheflush.h
+++ b/include/asm-generic/cacheflush.h
@@ -13,6 +13,7 @@
#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)
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 474792b825d0..7fc5606e6ea5 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -391,6 +391,18 @@ extern struct bio *bio_copy_kern(struct request_queue *, void *, unsigned int,
gfp_t, int);
extern void bio_set_pages_dirty(struct bio *bio);
extern void bio_check_pages_dirty(struct bio *bio);
+
+#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
+#endif
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+extern void bio_flush_dcache_pages(struct bio *bi);
+#else
+static inline void bio_flush_dcache_pages(struct bio *bi)
+{
+}
+#endif
+
extern struct bio *bio_copy_user(struct request_queue *, struct rq_map_data *,
unsigned long, unsigned int, int, gfp_t);
extern struct bio *bio_copy_user_iov(struct request_queue *,
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1cc02972fbe2..e727f6c44c44 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -752,6 +752,17 @@ struct req_iterator {
#define rq_iter_last(rq, _iter) \
(_iter.bio->bi_next == NULL && _iter.i == _iter.bio->bi_vcnt-1)
+#ifndef ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+# error "You should define ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE for your platform"
+#endif
+#if ARCH_IMPLEMENTS_FLUSH_DCACHE_PAGE
+extern void rq_flush_dcache_pages(struct request *rq);
+#else
+static inline void rq_flush_dcache_pages(struct request *rq)
+{
+}
+#endif
+
extern int blk_register_queue(struct gendisk *disk);
extern void blk_unregister_queue(struct gendisk *disk);
extern void register_disk(struct gendisk *dev);