linux/arch/ia64/include/asm/cacheflush.h
Ilya Loginov 2d4dc890b5 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>
2009-11-26 09:16:19 +01:00

54 lines
1.7 KiB
C

#ifndef _ASM_IA64_CACHEFLUSH_H
#define _ASM_IA64_CACHEFLUSH_H
/*
* Copyright (C) 2002 Hewlett-Packard Co
* David Mosberger-Tang <davidm@hpl.hp.com>
*/
#include <linux/page-flags.h>
#include <linux/bitops.h>
#include <asm/page.h>
/*
* Cache flushing routines. This is the kind of stuff that can be very expensive, so try
* to avoid them whenever possible.
*/
#define flush_cache_all() do { } while (0)
#define flush_cache_mm(mm) do { } while (0)
#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 flush_icache_page(vma,page) 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 1
#define flush_dcache_page(page) \
do { \
clear_bit(PG_arch_1, &(page)->flags); \
} while (0)
#define flush_dcache_mmap_lock(mapping) do { } while (0)
#define flush_dcache_mmap_unlock(mapping) do { } while (0)
extern void flush_icache_range (unsigned long start, unsigned long end);
extern void clflush_cache_range(void *addr, int size);
#define flush_icache_user_range(vma, page, user_addr, len) \
do { \
unsigned long _addr = (unsigned long) page_address(page) + ((user_addr) & ~PAGE_MASK); \
flush_icache_range(_addr, _addr + (len)); \
} while (0)
#define copy_to_user_page(vma, page, vaddr, dst, src, len) \
do { memcpy(dst, src, len); \
flush_icache_user_range(vma, page, vaddr, len); \
} while (0)
#define copy_from_user_page(vma, page, vaddr, dst, src, len) \
memcpy(dst, src, len)
#endif /* _ASM_IA64_CACHEFLUSH_H */