diff options
Diffstat (limited to 'lib/dma-direct.c')
| -rw-r--r-- | lib/dma-direct.c | 35 |
1 files changed, 29 insertions, 6 deletions
diff --git a/lib/dma-direct.c b/lib/dma-direct.c index c9e8e21cb334..c0bba30fef0a 100644 --- a/lib/dma-direct.c +++ b/lib/dma-direct.c @@ -9,6 +9,7 @@ #include <linux/scatterlist.h> #include <linux/dma-contiguous.h> #include <linux/pfn.h> +#include <linux/set_memory.h> #define DIRECT_MAPPING_ERROR 0 @@ -20,6 +21,14 @@ #define ARCH_ZONE_DMA_BITS 24 #endif +/* + * For AMD SEV all DMA must be to unencrypted addresses. + */ +static inline bool force_dma_unencrypted(void) +{ + return sev_active(); +} + static bool check_addr(struct device *dev, dma_addr_t dma_addr, size_t size, const char *caller) @@ -37,7 +46,9 @@ check_addr(struct device *dev, dma_addr_t dma_addr, size_t size, static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) { - return phys_to_dma(dev, phys) + size - 1 <= dev->coherent_dma_mask; + dma_addr_t addr = force_dma_unencrypted() ? + __phys_to_dma(dev, phys) : phys_to_dma(dev, phys); + return addr + size - 1 <= dev->coherent_dma_mask; } void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, @@ -46,6 +57,10 @@ void *dma_direct_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; int page_order = get_order(size); struct page *page = NULL; + void *ret; + + /* we always manually zero the memory once we are done: */ + gfp &= ~__GFP_ZERO; /* GFP_DMA32 and GFP_DMA are no ops without the corresponding zones: */ if (dev->coherent_dma_mask <= DMA_BIT_MASK(ARCH_ZONE_DMA_BITS)) @@ -78,10 +93,15 @@ again: if (!page) return NULL; - - *dma_handle = phys_to_dma(dev, page_to_phys(page)); - memset(page_address(page), 0, size); - return page_address(page); + ret = page_address(page); + if (force_dma_unencrypted()) { + set_memory_decrypted((unsigned long)ret, 1 << page_order); + *dma_handle = __phys_to_dma(dev, page_to_phys(page)); + } else { + *dma_handle = phys_to_dma(dev, page_to_phys(page)); + } + memset(ret, 0, size); + return ret; } /* @@ -92,9 +112,12 @@ void dma_direct_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs) { unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; + unsigned int page_order = get_order(size); + if (force_dma_unencrypted()) + set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order); if (!dma_release_from_contiguous(dev, virt_to_page(cpu_addr), count)) - free_pages((unsigned long)cpu_addr, get_order(size)); + free_pages((unsigned long)cpu_addr, page_order); } static dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, |