1 /* 2 * arch/sh/mm/consistent.c 3 * 4 * Copyright (C) 2004 Paul Mundt 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10 #include <linux/mm.h> 11 #include <linux/dma-mapping.h> 12 #include <asm/io.h> 13 14 void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle) 15 { 16 struct page *page, *end, *free; 17 void *ret; 18 int order; 19 20 size = PAGE_ALIGN(size); 21 order = get_order(size); 22 23 page = alloc_pages(gfp, order); 24 if (!page) 25 return NULL; 26 split_page(page, order); 27 28 ret = page_address(page); 29 *handle = virt_to_phys(ret); 30 31 /* 32 * We must flush the cache before we pass it on to the device 33 */ 34 dma_cache_wback_inv(ret, size); 35 36 page = virt_to_page(ret); 37 free = page + (size >> PAGE_SHIFT); 38 end = page + (1 << order); 39 40 while (++page < end) { 41 /* Free any unused pages */ 42 if (page >= free) { 43 __free_page(page); 44 } 45 } 46 47 return P2SEGADDR(ret); 48 } 49 50 void consistent_free(void *vaddr, size_t size) 51 { 52 unsigned long addr = P1SEGADDR((unsigned long)vaddr); 53 struct page *page=virt_to_page(addr); 54 int num_pages=(size+PAGE_SIZE-1) >> PAGE_SHIFT; 55 int i; 56 57 for(i=0;i<num_pages;i++) { 58 __free_page((page+i)); 59 } 60 } 61 62 void consistent_sync(void *vaddr, size_t size, int direction) 63 { 64 void * p1addr = (void*) P1SEGADDR((unsigned long)vaddr); 65 66 switch (direction) { 67 case DMA_FROM_DEVICE: /* invalidate only */ 68 dma_cache_inv(p1addr, size); 69 break; 70 case DMA_TO_DEVICE: /* writeback only */ 71 dma_cache_wback(p1addr, size); 72 break; 73 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 74 dma_cache_wback_inv(p1addr, size); 75 break; 76 default: 77 BUG(); 78 } 79 } 80 81 EXPORT_SYMBOL(consistent_alloc); 82 EXPORT_SYMBOL(consistent_free); 83 EXPORT_SYMBOL(consistent_sync); 84 85