diff options
Diffstat (limited to 'kernel/dma/swiotlb.c')
| -rw-r--r-- | kernel/dma/swiotlb.c | 232 |
1 files changed, 13 insertions, 219 deletions
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 2e126bac5d7d..d6361776dc5c 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -21,7 +21,6 @@ #include <linux/cache.h> #include <linux/dma-direct.h> -#include <linux/dma-noncoherent.h> #include <linux/mm.h> #include <linux/export.h> #include <linux/spinlock.h> @@ -65,7 +64,7 @@ enum swiotlb_force swiotlb_force; * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this * API. */ -static phys_addr_t io_tlb_start, io_tlb_end; +phys_addr_t io_tlb_start, io_tlb_end; /* * The number of IO TLB blocks (in groups of 64) between io_tlb_start and @@ -383,11 +382,6 @@ void __init swiotlb_exit(void) max_segment = 0; } -static int is_swiotlb_buffer(phys_addr_t paddr) -{ - return paddr >= io_tlb_start && paddr < io_tlb_end; -} - /* * Bounce: copy the swiotlb buffer back to the original dma location */ @@ -623,221 +617,36 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr, } } -static dma_addr_t swiotlb_bounce_page(struct device *dev, phys_addr_t *phys, +/* + * Create a swiotlb mapping for the buffer at @phys, and in case of DMAing + * to the device copy the data into it as well. + */ +bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr, size_t size, enum dma_data_direction dir, unsigned long attrs) { - dma_addr_t dma_addr; + trace_swiotlb_bounced(dev, *dma_addr, size, swiotlb_force); if (unlikely(swiotlb_force == SWIOTLB_NO_FORCE)) { dev_warn_ratelimited(dev, "Cannot do DMA to address %pa\n", phys); - return DMA_MAPPING_ERROR; + return false; } /* Oh well, have to allocate and map a bounce buffer. */ *phys = swiotlb_tbl_map_single(dev, __phys_to_dma(dev, io_tlb_start), *phys, size, dir, attrs); if (*phys == DMA_MAPPING_ERROR) - return DMA_MAPPING_ERROR; + return false; /* Ensure that the address returned is DMA'ble */ - dma_addr = __phys_to_dma(dev, *phys); - if (unlikely(!dma_capable(dev, dma_addr, size))) { + *dma_addr = __phys_to_dma(dev, *phys); + if (unlikely(!dma_capable(dev, *dma_addr, size))) { swiotlb_tbl_unmap_single(dev, *phys, size, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC); - return DMA_MAPPING_ERROR; - } - - return dma_addr; -} - -/* - * Map a single buffer of the indicated size for DMA in streaming mode. The - * physical address to use is returned. - * - * Once the device is given the dma address, the device owns this memory until - * either swiotlb_unmap_page or swiotlb_dma_sync_single is performed. - */ -dma_addr_t swiotlb_map_page(struct device *dev, struct page *page, - unsigned long offset, size_t size, - enum dma_data_direction dir, - unsigned long attrs) -{ - phys_addr_t phys = page_to_phys(page) + offset; - dma_addr_t dev_addr = phys_to_dma(dev, phys); - - BUG_ON(dir == DMA_NONE); - /* - * If the address happens to be in the device's DMA window, - * we can safely return the device addr and not worry about bounce - * buffering it. - */ - if (!dma_capable(dev, dev_addr, size) || - swiotlb_force == SWIOTLB_FORCE) { - trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force); - dev_addr = swiotlb_bounce_page(dev, &phys, size, dir, attrs); + return false; } - if (!dev_is_dma_coherent(dev) && - (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0 && - dev_addr != DMA_MAPPING_ERROR) - arch_sync_dma_for_device(dev, phys, size, dir); - - return dev_addr; -} - -/* - * Unmap a single streaming mode DMA translation. The dma_addr and size must - * match what was provided for in a previous swiotlb_map_page call. All - * other usages are undefined. - * - * After this call, reads by the cpu to the buffer are guaranteed to see - * whatever the device wrote there. - */ -void swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, - size_t size, enum dma_data_direction dir, - unsigned long attrs) -{ - phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); - - BUG_ON(dir == DMA_NONE); - - if (!dev_is_dma_coherent(hwdev) && - (attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0) - arch_sync_dma_for_cpu(hwdev, paddr, size, dir); - - if (is_swiotlb_buffer(paddr)) - swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs); -} - -/* - * Make physical memory consistent for a single streaming mode DMA translation - * after a transfer. - * - * If you perform a swiotlb_map_page() but wish to interrogate the buffer - * using the cpu, yet do not wish to teardown the dma mapping, you must - * call this function before doing so. At the next point you give the dma - * address back to the card, you must first perform a - * swiotlb_dma_sync_for_device, and then the device again owns the buffer - */ -static void -swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, - size_t size, enum dma_data_direction dir, - enum dma_sync_target target) -{ - phys_addr_t paddr = dma_to_phys(hwdev, dev_addr); - - BUG_ON(dir == DMA_NONE); - - if (!dev_is_dma_coherent(hwdev) && target == SYNC_FOR_CPU) - arch_sync_dma_for_cpu(hwdev, paddr, size, dir); - - if (is_swiotlb_buffer(paddr)) - swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target); - - if (!dev_is_dma_coherent(hwdev) && target == SYNC_FOR_DEVICE) - arch_sync_dma_for_device(hwdev, paddr, size, dir); -} - -void -swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr, - size_t size, enum dma_data_direction dir) -{ - swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU); -} - -void -swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr, - size_t size, enum dma_data_direction dir) -{ - swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE); -} - -/* - * Map a set of buffers described by scatterlist in streaming mode for DMA. - * This is the scatter-gather version of the above swiotlb_map_page - * interface. Here the scatter gather list elements are each tagged with the - * appropriate dma address and length. They are obtained via - * sg_dma_{address,length}(SG). - * - * Device ownership issues as mentioned above for swiotlb_map_page are the - * same here. - */ -int -swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl, int nelems, - enum dma_data_direction dir, unsigned long attrs) -{ - struct scatterlist *sg; - int i; - - for_each_sg(sgl, sg, nelems, i) { - sg->dma_address = swiotlb_map_page(dev, sg_page(sg), sg->offset, - sg->length, dir, attrs); - if (sg->dma_address == DMA_MAPPING_ERROR) - goto out_error; - sg_dma_len(sg) = sg->length; - } - - return nelems; - -out_error: - swiotlb_unmap_sg_attrs(dev, sgl, i, dir, - attrs | DMA_ATTR_SKIP_CPU_SYNC); - sg_dma_len(sgl) = 0; - return 0; -} - -/* - * Unmap a set of streaming mode DMA translations. Again, cpu read rules - * concerning calls here are the same as for swiotlb_unmap_page() above. - */ -void -swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, - int nelems, enum dma_data_direction dir, - unsigned long attrs) -{ - struct scatterlist *sg; - int i; - - BUG_ON(dir == DMA_NONE); - - for_each_sg(sgl, sg, nelems, i) - swiotlb_unmap_page(hwdev, sg->dma_address, sg_dma_len(sg), dir, - attrs); -} - -/* - * Make physical memory consistent for a set of streaming mode DMA translations - * after a transfer. - * - * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules - * and usage. - */ -static void -swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl, - int nelems, enum dma_data_direction dir, - enum dma_sync_target target) -{ - struct scatterlist *sg; - int i; - - for_each_sg(sgl, sg, nelems, i) - swiotlb_sync_single(hwdev, sg->dma_address, - sg_dma_len(sg), dir, target); -} - -void -swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg, - int nelems, enum dma_data_direction dir) -{ - swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU); -} - -void -swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg, - int nelems, enum dma_data_direction dir) -{ - swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE); + return true; } /* @@ -851,18 +660,3 @@ swiotlb_dma_supported(struct device *hwdev, u64 mask) { return __phys_to_dma(hwdev, io_tlb_end - 1) <= mask; } - -const struct dma_map_ops swiotlb_dma_ops = { - .alloc = dma_direct_alloc, - .free = dma_direct_free, - .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, - .map_sg = swiotlb_map_sg_attrs, - .unmap_sg = swiotlb_unmap_sg_attrs, - .map_page = swiotlb_map_page, - .unmap_page = swiotlb_unmap_page, - .dma_supported = dma_direct_supported, -}; -EXPORT_SYMBOL(swiotlb_dma_ops); |