diff options
author | Rodrigo Vivi <[email protected]> | 2018-07-23 09:13:12 -0700 |
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committer | Rodrigo Vivi <[email protected]> | 2018-07-23 09:13:12 -0700 |
commit | c74a7469f97c0f40b46e82ee979f9fb1bb6e847c (patch) | |
tree | f2690a1a916b73ef94657fbf0e0141ae57701825 /kernel/dma/virt.c | |
parent | 6f15a7de86c8cf2dc09fc9e6d07047efa40ef809 (diff) | |
parent | 500775074f88d9cf5416bed2ca19592812d62c41 (diff) |
Merge drm/drm-next into drm-intel-next-queued
We need a backmerge to get DP_DPCD_REV_14 before we push other
i915 changes to dinq that could break compilation.
Signed-off-by: Rodrigo Vivi <[email protected]>
Diffstat (limited to 'kernel/dma/virt.c')
-rw-r--r-- | kernel/dma/virt.c | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/kernel/dma/virt.c b/kernel/dma/virt.c new file mode 100644 index 000000000000..631ddec4b60a --- /dev/null +++ b/kernel/dma/virt.c @@ -0,0 +1,59 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * DMA operations that map to virtual addresses without flushing memory. + */ +#include <linux/export.h> +#include <linux/mm.h> +#include <linux/dma-mapping.h> +#include <linux/scatterlist.h> + +static void *dma_virt_alloc(struct device *dev, size_t size, + dma_addr_t *dma_handle, gfp_t gfp, + unsigned long attrs) +{ + void *ret; + + ret = (void *)__get_free_pages(gfp, get_order(size)); + if (ret) + *dma_handle = (uintptr_t)ret; + return ret; +} + +static void dma_virt_free(struct device *dev, size_t size, + void *cpu_addr, dma_addr_t dma_addr, + unsigned long attrs) +{ + free_pages((unsigned long)cpu_addr, get_order(size)); +} + +static dma_addr_t dma_virt_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, + unsigned long attrs) +{ + return (uintptr_t)(page_address(page) + offset); +} + +static int dma_virt_map_sg(struct device *dev, struct scatterlist *sgl, + int nents, enum dma_data_direction dir, + unsigned long attrs) +{ + int i; + struct scatterlist *sg; + + for_each_sg(sgl, sg, nents, i) { + BUG_ON(!sg_page(sg)); + sg_dma_address(sg) = (uintptr_t)sg_virt(sg); + sg_dma_len(sg) = sg->length; + } + + return nents; +} + +const struct dma_map_ops dma_virt_ops = { + .alloc = dma_virt_alloc, + .free = dma_virt_free, + .map_page = dma_virt_map_page, + .map_sg = dma_virt_map_sg, +}; +EXPORT_SYMBOL(dma_virt_ops); |