linux/arch/powerpc/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

76 lines
2.7 KiB
C

/*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef _ASM_POWERPC_CACHEFLUSH_H
#define _ASM_POWERPC_CACHEFLUSH_H
#ifdef __KERNEL__
#include <linux/mm.h>
#include <asm/cputable.h>
/*
* No cache flushing is required when address mappings are changed,
* because the caches on PowerPCs are physically addressed.
*/
#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
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)
extern void __flush_icache_range(unsigned long, unsigned long);
static inline void flush_icache_range(unsigned long start, unsigned long stop)
{
if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
__flush_icache_range(start, stop);
}
extern void flush_icache_user_range(struct vm_area_struct *vma,
struct page *page, unsigned long addr,
int len);
extern void __flush_dcache_icache(void *page_va);
extern void flush_dcache_icache_page(struct page *page);
#if defined(CONFIG_PPC32) && !defined(CONFIG_BOOKE)
extern void __flush_dcache_icache_phys(unsigned long physaddr);
#endif /* CONFIG_PPC32 && !CONFIG_BOOKE */
extern void flush_dcache_range(unsigned long start, unsigned long stop);
#ifdef CONFIG_PPC32
extern void clean_dcache_range(unsigned long start, unsigned long stop);
extern void invalidate_dcache_range(unsigned long start, unsigned long stop);
#endif /* CONFIG_PPC32 */
#ifdef CONFIG_PPC64
extern void flush_inval_dcache_range(unsigned long start, unsigned long stop);
extern void flush_dcache_phys_range(unsigned long start, unsigned long stop);
#endif
#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)
#ifdef CONFIG_DEBUG_PAGEALLOC
/* internal debugging function */
void kernel_map_pages(struct page *page, int numpages, int enable);
#endif
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_CACHEFLUSH_H */