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/vmalloc.h> 25 #include <linux/swiotlb.h> 26 27 #include <asm/cacheflush.h> 28 29 struct dma_map_ops *dma_ops; 30 EXPORT_SYMBOL(dma_ops); 31 32 static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size, 33 dma_addr_t *dma_handle, gfp_t flags, 34 struct dma_attrs *attrs) 35 { 36 if (IS_ENABLED(CONFIG_ZONE_DMA32) && 37 dev->coherent_dma_mask <= DMA_BIT_MASK(32)) 38 flags |= GFP_DMA32; 39 return swiotlb_alloc_coherent(dev, size, dma_handle, flags); 40 } 41 42 static void arm64_swiotlb_free_coherent(struct device *dev, size_t size, 43 void *vaddr, dma_addr_t dma_handle, 44 struct dma_attrs *attrs) 45 { 46 swiotlb_free_coherent(dev, size, vaddr, dma_handle); 47 } 48 49 static struct dma_map_ops arm64_swiotlb_dma_ops = { 50 .alloc = arm64_swiotlb_alloc_coherent, 51 .free = arm64_swiotlb_free_coherent, 52 .map_page = swiotlb_map_page, 53 .unmap_page = swiotlb_unmap_page, 54 .map_sg = swiotlb_map_sg_attrs, 55 .unmap_sg = swiotlb_unmap_sg_attrs, 56 .sync_single_for_cpu = swiotlb_sync_single_for_cpu, 57 .sync_single_for_device = swiotlb_sync_single_for_device, 58 .sync_sg_for_cpu = swiotlb_sync_sg_for_cpu, 59 .sync_sg_for_device = swiotlb_sync_sg_for_device, 60 .dma_supported = swiotlb_dma_supported, 61 .mapping_error = swiotlb_dma_mapping_error, 62 }; 63 64 void __init arm64_swiotlb_init(void) 65 { 66 dma_ops = &arm64_swiotlb_dma_ops; 67 swiotlb_init(1); 68 } 69 70 #define PREALLOC_DMA_DEBUG_ENTRIES 4096 71 72 static int __init dma_debug_do_init(void) 73 { 74 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); 75 return 0; 76 } 77 fs_initcall(dma_debug_do_init); 78