8dfcc9ba27
Have an explicit mm call to split higher order pages into individual pages. Should help to avoid bugs and be more explicit about the code's intention. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Russell King <rmk@arm.linux.org.uk> Cc: David Howells <dhowells@redhat.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mundt <lethal@linux-sh.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Zankel <chris@zankel.net> Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
84 lines
1.7 KiB
C
84 lines
1.7 KiB
C
/*
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* arch/sh/mm/consistent.c
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*
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* Copyright (C) 2004 Paul Mundt
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*/
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#include <linux/mm.h>
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#include <linux/dma-mapping.h>
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#include <asm/io.h>
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void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle)
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{
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struct page *page, *end, *free;
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void *ret;
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int order;
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size = PAGE_ALIGN(size);
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order = get_order(size);
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page = alloc_pages(gfp, order);
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if (!page)
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return NULL;
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split_page(page, order);
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ret = page_address(page);
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*handle = virt_to_phys(ret);
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/*
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* We must flush the cache before we pass it on to the device
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*/
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dma_cache_wback_inv(ret, size);
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page = virt_to_page(ret);
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free = page + (size >> PAGE_SHIFT);
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end = page + (1 << order);
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while (++page < end) {
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/* Free any unused pages */
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if (page >= free) {
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__free_page(page);
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}
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}
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return P2SEGADDR(ret);
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}
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void consistent_free(void *vaddr, size_t size)
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{
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unsigned long addr = P1SEGADDR((unsigned long)vaddr);
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struct page *page=virt_to_page(addr);
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int num_pages=(size+PAGE_SIZE-1) >> PAGE_SHIFT;
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int i;
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for(i=0;i<num_pages;i++) {
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__free_page((page+i));
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}
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}
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void consistent_sync(void *vaddr, size_t size, int direction)
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{
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void * p1addr = (void*) P1SEGADDR((unsigned long)vaddr);
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switch (direction) {
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case DMA_FROM_DEVICE: /* invalidate only */
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dma_cache_inv(p1addr, size);
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break;
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case DMA_TO_DEVICE: /* writeback only */
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dma_cache_wback(p1addr, size);
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break;
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case DMA_BIDIRECTIONAL: /* writeback and invalidate */
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dma_cache_wback_inv(p1addr, size);
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break;
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default:
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BUG();
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}
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}
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EXPORT_SYMBOL(consistent_alloc);
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EXPORT_SYMBOL(consistent_free);
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EXPORT_SYMBOL(consistent_sync);
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