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 27 ret = page_address(page); 28 *handle = virt_to_phys(ret); 29 30 /* 31 * We must flush the cache before we pass it on to the device 32 */ 33 dma_cache_wback_inv(ret, size); 34 35 page = virt_to_page(ret); 36 free = page + (size >> PAGE_SHIFT); 37 end = page + (1 << order); 38 39 while (++page < end) { 40 set_page_count(page, 1); 41 42 /* Free any unused pages */ 43 if (page >= free) { 44 __free_page(page); 45 } 46 } 47 48 return P2SEGADDR(ret); 49 } 50 51 void consistent_free(void *vaddr, size_t size) 52 { 53 unsigned long addr = P1SEGADDR((unsigned long)vaddr); 54 struct page *page=virt_to_page(addr); 55 int num_pages=(size+PAGE_SIZE-1) >> PAGE_SHIFT; 56 int i; 57 58 for(i=0;i<num_pages;i++) { 59 __free_page((page+i)); 60 } 61 } 62 63 void consistent_sync(void *vaddr, size_t size, int direction) 64 { 65 void * p1addr = (void*) P1SEGADDR((unsigned long)vaddr); 66 67 switch (direction) { 68 case DMA_FROM_DEVICE: /* invalidate only */ 69 dma_cache_inv(p1addr, size); 70 break; 71 case DMA_TO_DEVICE: /* writeback only */ 72 dma_cache_wback(p1addr, size); 73 break; 74 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 75 dma_cache_wback_inv(p1addr, size); 76 break; 77 default: 78 BUG(); 79 } 80 } 81 82 EXPORT_SYMBOL(consistent_alloc); 83 EXPORT_SYMBOL(consistent_free); 84 EXPORT_SYMBOL(consistent_sync); 85 86