1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Copyright (C) 2004 - 2007 Paul Mundt 4 */ 5 #include <linux/mm.h> 6 #include <linux/init.h> 7 #include <linux/dma-noncoherent.h> 8 #include <linux/module.h> 9 #include <asm/cacheflush.h> 10 #include <asm/addrspace.h> 11 12 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, 13 gfp_t gfp, unsigned long attrs) 14 { 15 void *ret, *ret_nocache; 16 int order = get_order(size); 17 18 gfp |= __GFP_ZERO; 19 20 ret = (void *)__get_free_pages(gfp, order); 21 if (!ret) 22 return NULL; 23 24 /* 25 * Pages from the page allocator may have data present in 26 * cache. So flush the cache before using uncached memory. 27 */ 28 arch_sync_dma_for_device(virt_to_phys(ret), size, 29 DMA_BIDIRECTIONAL); 30 31 ret_nocache = (void __force *)ioremap_nocache(virt_to_phys(ret), size); 32 if (!ret_nocache) { 33 free_pages((unsigned long)ret, order); 34 return NULL; 35 } 36 37 split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); 38 39 *dma_handle = virt_to_phys(ret); 40 if (!WARN_ON(!dev)) 41 *dma_handle -= PFN_PHYS(dev->dma_pfn_offset); 42 43 return ret_nocache; 44 } 45 46 void arch_dma_free(struct device *dev, size_t size, void *vaddr, 47 dma_addr_t dma_handle, unsigned long attrs) 48 { 49 int order = get_order(size); 50 unsigned long pfn = (dma_handle >> PAGE_SHIFT); 51 int k; 52 53 if (!WARN_ON(!dev)) 54 pfn += dev->dma_pfn_offset; 55 56 for (k = 0; k < (1 << order); k++) 57 __free_pages(pfn_to_page(pfn + k), 0); 58 59 iounmap(vaddr); 60 } 61 62 void arch_sync_dma_for_device(phys_addr_t paddr, size_t size, 63 enum dma_data_direction dir) 64 { 65 void *addr = sh_cacheop_vaddr(phys_to_virt(paddr)); 66 67 switch (dir) { 68 case DMA_FROM_DEVICE: /* invalidate only */ 69 __flush_invalidate_region(addr, size); 70 break; 71 case DMA_TO_DEVICE: /* writeback only */ 72 __flush_wback_region(addr, size); 73 break; 74 case DMA_BIDIRECTIONAL: /* writeback and invalidate */ 75 __flush_purge_region(addr, size); 76 break; 77 default: 78 BUG(); 79 } 80 } 81