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/cacheflush.h> 13 #include <asm/addrspace.h> 14 #include <asm/io.h> 15 16 void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *handle) 17 { 18 struct page *page, *end, *free; 19 void *ret; 20 int order; 21 22 size = PAGE_ALIGN(size); 23 order = get_order(size); 24 25 page = alloc_pages(gfp, order); 26 if (!page) 27 return NULL; 28 split_page(page, order); 29 30 ret = page_address(page); 31 memset(ret, 0, size); 32 *handle = virt_to_phys(ret); 33 34 /* 35 * We must flush the cache before we pass it on to the device 36 */ 37 __flush_purge_region(ret, size); 38 39 page = virt_to_page(ret); 40 free = page + (size >> PAGE_SHIFT); 41 end = page + (1 << order); 42 43 while (++page < end) { 44 /* Free any unused pages */ 45 if (page >= free) { 46 __free_page(page); 47 } 48 } 49 50 return P2SEGADDR(ret); 51 } 52 53 void consistent_free(void *vaddr, size_t size) 54 { 55 unsigned long addr = P1SEGADDR((unsigned long)vaddr); 56 struct page *page=virt_to_page(addr); 57 int num_pages=(size+PAGE_SIZE-1) >> PAGE_SHIFT; 58 int i; 59 60 for(i=0;i<num_pages;i++) { 61 __free_page((page+i)); 62 } 63 } 64 65 void consistent_sync(void *vaddr, size_t size, int direction) 66 { 67 void * p1addr = (void*) P1SEGADDR((unsigned long)vaddr); 68 69 switch (direction) { 70 case DMA_FROM_DEVICE: /* invalidate only */ 71 __flush_invalidate_region(p1addr, size); 72 break; 73 case DMA_TO_DEVICE: /* writeback only */ 74 __flush_wback_region(p1addr, size); 75 break; 76 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 77 __flush_purge_region(p1addr, size); 78 break; 79 default: 80 BUG(); 81 } 82 } 83 84 EXPORT_SYMBOL(consistent_alloc); 85 EXPORT_SYMBOL(consistent_free); 86 EXPORT_SYMBOL(consistent_sync); 87 88