1 /* 2 * SWIOTLB-based DMA API implementation 3 * 4 * Copyright (C) 2012 ARM Ltd. 5 * Author: Catalin Marinas <catalin.marinas@arm.com> 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program. If not, see <http://www.gnu.org/licenses/>. 18 */ 19 20 #include <linux/gfp.h> 21 #include <linux/export.h> 22 #include <linux/slab.h> 23 #include <linux/dma-mapping.h> 24 #include <linux/dma-contiguous.h> 25 #include <linux/vmalloc.h> 26 #include <linux/swiotlb.h> 27 28 #include <asm/cacheflush.h> 29 30 struct dma_map_ops *dma_ops; 31 EXPORT_SYMBOL(dma_ops); 32 33 static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size, 34 dma_addr_t *dma_handle, gfp_t flags, 35 struct dma_attrs *attrs) 36 { 37 if (dev == NULL) { 38 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n"); 39 return NULL; 40 } 41 42 if (IS_ENABLED(CONFIG_ZONE_DMA32) && 43 dev->coherent_dma_mask <= DMA_BIT_MASK(32)) 44 flags |= GFP_DMA32; 45 if (IS_ENABLED(CONFIG_DMA_CMA)) { 46 struct page *page; 47 48 size = PAGE_ALIGN(size); 49 page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT, 50 get_order(size)); 51 if (!page) 52 return NULL; 53 54 *dma_handle = phys_to_dma(dev, page_to_phys(page)); 55 return page_address(page); 56 } else { 57 return swiotlb_alloc_coherent(dev, size, dma_handle, flags); 58 } 59 } 60 61 static void arm64_swiotlb_free_coherent(struct device *dev, size_t size, 62 void *vaddr, dma_addr_t dma_handle, 63 struct dma_attrs *attrs) 64 { 65 if (dev == NULL) { 66 WARN_ONCE(1, "Use an actual device structure for DMA allocation\n"); 67 return; 68 } 69 70 if (IS_ENABLED(CONFIG_DMA_CMA)) { 71 phys_addr_t paddr = dma_to_phys(dev, dma_handle); 72 73 dma_release_from_contiguous(dev, 74 phys_to_page(paddr), 75 size >> PAGE_SHIFT); 76 } else { 77 swiotlb_free_coherent(dev, size, vaddr, dma_handle); 78 } 79 } 80 81 static struct dma_map_ops arm64_swiotlb_dma_ops = { 82 .alloc = arm64_swiotlb_alloc_coherent, 83 .free = arm64_swiotlb_free_coherent, 84 .map_page = swiotlb_map_page, 85 .unmap_page = swiotlb_unmap_page, 86 .map_sg = swiotlb_map_sg_attrs, 87 .unmap_sg = swiotlb_unmap_sg_attrs, 88 .sync_single_for_cpu = swiotlb_sync_single_for_cpu, 89 .sync_single_for_device = swiotlb_sync_single_for_device, 90 .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, 91 .sync_sg_for_device = swiotlb_sync_sg_for_device, 92 .dma_supported = swiotlb_dma_supported, 93 .mapping_error = swiotlb_dma_mapping_error, 94 }; 95 96 void __init arm64_swiotlb_init(void) 97 { 98 dma_ops = &arm64_swiotlb_dma_ops; 99 swiotlb_init(1); 100 } 101 102 #define PREALLOC_DMA_DEBUG_ENTRIES 4096 103 104 static int __init dma_debug_do_init(void) 105 { 106 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); 107 return 0; 108 } 109 fs_initcall(dma_debug_do_init); 110