1 /* 2 * Copyright (C) 2004 - 2007 Paul Mundt 3 * 4 * This file is subject to the terms and conditions of the GNU General Public 5 * License. See the file "COPYING" in the main directory of this archive 6 * for more details. 7 */ 8 #include <linux/mm.h> 9 #include <linux/init.h> 10 #include <linux/dma-noncoherent.h> 11 #include <linux/module.h> 12 #include <asm/cacheflush.h> 13 #include <asm/addrspace.h> 14 15 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, 16 gfp_t gfp, unsigned long attrs) 17 { 18 void *ret, *ret_nocache; 19 int order = get_order(size); 20 21 gfp |= __GFP_ZERO; 22 23 ret = (void *)__get_free_pages(gfp, order); 24 if (!ret) 25 return NULL; 26 27 /* 28 * Pages from the page allocator may have data present in 29 * cache. So flush the cache before using uncached memory. 30 */ 31 arch_sync_dma_for_device(dev, virt_to_phys(ret), size, 32 DMA_BIDIRECTIONAL); 33 34 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size); 35 if (!ret_nocache) { 36 free_pages((unsigned long)ret, order); 37 return NULL; 38 } 39 40 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); 41 42 *dma_handle = virt_to_phys(ret); 43 if (!WARN_ON(!dev)) 44 *dma_handle -= PFN_PHYS(dev->dma_pfn_offset); 45 46 return ret_nocache; 47 } 48 49 void arch_dma_free(struct device *dev, size_t size, void *vaddr, 50 dma_addr_t dma_handle, unsigned long attrs) 51 { 52 int order = get_order(size); 53 unsigned long pfn = (dma_handle >> PAGE_SHIFT); 54 int k; 55 56 if (!WARN_ON(!dev)) 57 pfn += dev->dma_pfn_offset; 58 59 for (k = 0; k < (1 << order); k++) 60 __free_pages(pfn_to_page(pfn + k), 0); 61 62 iounmap(vaddr); 63 } 64 65 void arch_sync_dma_for_device(struct device *dev, phys_addr_t paddr, 66 size_t size, enum dma_data_direction dir) 67 { 68 void *addr = sh_cacheop_vaddr(phys_to_virt(paddr)); 69 70 switch (dir) { 71 case DMA_FROM_DEVICE: /* invalidate only */ 72 __flush_invalidate_region(addr, size); 73 break; 74 case DMA_TO_DEVICE: /* writeback only */ 75 __flush_wback_region(addr, size); 76 break; 77 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 78 __flush_purge_region(addr, size); 79 break; 80 default: 81 BUG(); 82 } 83 } 84