diff options
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/Kconfig | 10 | ||||
| -rw-r--r-- | lib/Makefile | 3 | ||||
| -rw-r--r-- | lib/dma-noop.c | 4 | ||||
| -rw-r--r-- | lib/dma-virt.c | 72 |
4 files changed, 86 insertions, 3 deletions
diff --git a/lib/Kconfig b/lib/Kconfig index fe7e8e175db8..8f69579dfac3 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -394,6 +394,16 @@ config HAS_DMA depends on !NO_DMA default y +config DMA_NOOP_OPS + bool + depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT) + default n + +config DMA_VIRT_OPS + bool + depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT) + default n + config CHECK_SIGNATURE bool diff --git a/lib/Makefile b/lib/Makefile index 445a39c21f46..c9023efbd4ca 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -27,7 +27,8 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ lib-$(CONFIG_MMU) += ioremap.o lib-$(CONFIG_SMP) += cpumask.o -lib-$(CONFIG_HAS_DMA) += dma-noop.o +lib-$(CONFIG_DMA_NOOP_OPS) += dma-noop.o +lib-$(CONFIG_DMA_VIRT_OPS) += dma-virt.o lib-y += kobject.o klist.o obj-y += lockref.o diff --git a/lib/dma-noop.c b/lib/dma-noop.c index 3d766e78fbe2..de26c8b68f34 100644 --- a/lib/dma-noop.c +++ b/lib/dma-noop.c @@ -1,7 +1,7 @@ /* * lib/dma-noop.c * - * Simple DMA noop-ops that map 1:1 with memory + * DMA operations that map to physical addresses without flushing memory. */ #include <linux/export.h> #include <linux/mm.h> @@ -64,7 +64,7 @@ static int dma_noop_supported(struct device *dev, u64 mask) return 1; } -struct dma_map_ops dma_noop_ops = { +const struct dma_map_ops dma_noop_ops = { .alloc = dma_noop_alloc, .free = dma_noop_free, .map_page = dma_noop_map_page, diff --git a/lib/dma-virt.c b/lib/dma-virt.c new file mode 100644 index 000000000000..dcd4df1f7174 --- /dev/null +++ b/lib/dma-virt.c @@ -0,0 +1,72 @@ +/* + * lib/dma-virt.c + * + * 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; +} + +static int dma_virt_mapping_error(struct device *dev, dma_addr_t dma_addr) +{ + return false; +} + +static int dma_virt_supported(struct device *dev, u64 mask) +{ + return true; +} + +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, + .mapping_error = dma_virt_mapping_error, + .dma_supported = dma_virt_supported, +}; +EXPORT_SYMBOL(dma_virt_ops); |