arch/arm64/mm/dma-mapping.c

   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);