dma-mapping.c
2.99 KB
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/*
* SWIOTLB-based DMA API implementation
*
* Copyright (C) 2012 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/gfp.h>
#include <linux/export.h>
#include <linux/slab.h>
#include <linux/dma-mapping.h>
#include <linux/dma-contiguous.h>
#include <linux/vmalloc.h>
#include <linux/swiotlb.h>
#include <asm/cacheflush.h>
struct dma_map_ops *dma_ops;
EXPORT_SYMBOL(dma_ops);
static void *arm64_swiotlb_alloc_coherent(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flags,
struct dma_attrs *attrs)
{
if (dev == NULL) {
WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
return NULL;
}
if (IS_ENABLED(CONFIG_ZONE_DMA32) &&
dev->coherent_dma_mask <= DMA_BIT_MASK(32))
flags |= GFP_DMA32;
if (IS_ENABLED(CONFIG_DMA_CMA)) {
struct page *page;
size = PAGE_ALIGN(size);
page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
get_order(size));
if (!page)
return NULL;
*dma_handle = phys_to_dma(dev, page_to_phys(page));
return page_address(page);
} else {
return swiotlb_alloc_coherent(dev, size, dma_handle, flags);
}
}
static void arm64_swiotlb_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
if (dev == NULL) {
WARN_ONCE(1, "Use an actual device structure for DMA allocation\n");
return;
}
if (IS_ENABLED(CONFIG_DMA_CMA)) {
phys_addr_t paddr = dma_to_phys(dev, dma_handle);
dma_release_from_contiguous(dev,
phys_to_page(paddr),
size >> PAGE_SHIFT);
} else {
swiotlb_free_coherent(dev, size, vaddr, dma_handle);
}
}
static struct dma_map_ops arm64_swiotlb_dma_ops = {
.alloc = arm64_swiotlb_alloc_coherent,
.free = arm64_swiotlb_free_coherent,
.map_page = swiotlb_map_page,
.unmap_page = swiotlb_unmap_page,
.map_sg = swiotlb_map_sg_attrs,
.unmap_sg = swiotlb_unmap_sg_attrs,
.sync_single_for_cpu = swiotlb_sync_single_for_cpu,
.sync_single_for_device = swiotlb_sync_single_for_device,
.sync_sg_for_cpu = swiotlb_sync_sg_for_cpu,
.sync_sg_for_device = swiotlb_sync_sg_for_device,
.dma_supported = swiotlb_dma_supported,
.mapping_error = swiotlb_dma_mapping_error,
};
void __init arm64_swiotlb_init(void)
{
dma_ops = &arm64_swiotlb_dma_ops;
swiotlb_init(1);
}
#define PREALLOC_DMA_DEBUG_ENTRIES 4096
static int __init dma_debug_do_init(void)
{
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}
fs_initcall(dma_debug_do_init);