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linux-next/arch/avr32/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

133 lines
3.9 KiB
C

/*
* Copyright (C) 2004-2006 Atmel Corporation
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#ifndef __ASM_AVR32_CACHEFLUSH_H
#define __ASM_AVR32_CACHEFLUSH_H
/* Keep includes the same across arches. */
#include <linux/mm.h>
#define CACHE_OP_ICACHE_INVALIDATE 0x01
#define CACHE_OP_DCACHE_INVALIDATE 0x0b
#define CACHE_OP_DCACHE_CLEAN 0x0c
#define CACHE_OP_DCACHE_CLEAN_INVAL 0x0d
/*
* Invalidate any cacheline containing virtual address vaddr without
* writing anything back to memory.
*
* Note that this function may corrupt unrelated data structures when
* applied on buffers that are not cacheline aligned in both ends.
*/
static inline void invalidate_dcache_line(void *vaddr)
{
asm volatile("cache %0[0], %1"
:
: "r"(vaddr), "n"(CACHE_OP_DCACHE_INVALIDATE)
: "memory");
}
/*
* Make sure any cacheline containing virtual address vaddr is written
* to memory.
*/
static inline void clean_dcache_line(void *vaddr)
{
asm volatile("cache %0[0], %1"
:
: "r"(vaddr), "n"(CACHE_OP_DCACHE_CLEAN)
: "memory");
}
/*
* Make sure any cacheline containing virtual address vaddr is written
* to memory and then invalidate it.
*/
static inline void flush_dcache_line(void *vaddr)
{
asm volatile("cache %0[0], %1"
:
: "r"(vaddr), "n"(CACHE_OP_DCACHE_CLEAN_INVAL)
: "memory");
}
/*
* Invalidate any instruction cacheline containing virtual address
* vaddr.
*/
static inline void invalidate_icache_line(void *vaddr)
{
asm volatile("cache %0[0], %1"
:
: "r"(vaddr), "n"(CACHE_OP_ICACHE_INVALIDATE)
: "memory");
}
/*
* Applies the above functions on all lines that are touched by the
* specified virtual address range.
*/
void invalidate_dcache_region(void *start, size_t len);
void clean_dcache_region(void *start, size_t len);
void flush_dcache_region(void *start, size_t len);
void invalidate_icache_region(void *start, size_t len);
/*
* Make sure any pending writes are completed before continuing.
*/
#define flush_write_buffer() asm volatile("sync 0" : : : "memory")
/*
* The following functions are called when a virtual mapping changes.
* We do not need to flush anything in this case.
*/
#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_cache_vmap(start, end) do { } while (0)
#define flush_cache_vunmap(start, end) do { } while (0)
/*
* I think we need to implement this one to be able to reliably
* execute pages from RAMDISK. However, if we implement the
* flush_dcache_*() functions, it might not be needed anymore.
*
* #define flush_icache_page(vma, page) do { } while (0)
*/
extern void flush_icache_page(struct vm_area_struct *vma, struct page *page);
/*
* These are (I think) related to D-cache aliasing. We might need to
* 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)
/*
* These are for I/D cache coherency. In this case, we do need to
* flush with all configurations.
*/
extern void flush_icache_range(unsigned long start, unsigned long end);
extern void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
unsigned long vaddr, void *dst, const void *src,
unsigned long len);
static inline void copy_from_user_page(struct vm_area_struct *vma,
struct page *page, unsigned long vaddr, void *dst,
const void *src, unsigned long len)
{
memcpy(dst, src, len);
}
#endif /* __ASM_AVR32_CACHEFLUSH_H */