From cf65a0f6f6ff7631ba0ac0513a14ca5b65320d80 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 12 Jun 2018 19:01:45 +0200 Subject: dma-mapping: move all DMA mapping code to kernel/dma Currently the code is split over various files with dma- prefixes in the lib/ and drives/base directories, and the number of files keeps growing. Move them into a single directory to keep the code together and remove the file name prefixes. To match the irq infrastructure this directory is placed under the kernel/ directory. Signed-off-by: Christoph Hellwig --- lib/dma-direct.c | 204 ------------------------------------------------------- 1 file changed, 204 deletions(-) delete mode 100644 lib/dma-direct.c (limited to 'lib/dma-direct.c') diff --git a/lib/dma-direct.c b/lib/dma-direct.c deleted file mode 100644 index 8be8106270c2..000000000000 --- a/lib/dma-direct.c +++ /dev/null @@ -1,204 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * DMA operations that map physical memory directly without using an IOMMU or - * flushing caches. - */ -#include -#include -#include -#include -#include -#include -#include - -#define DIRECT_MAPPING_ERROR 0 - -/* - * Most architectures use ZONE_DMA for the first 16 Megabytes, but - * some use it for entirely different regions: - */ -#ifndef ARCH_ZONE_DMA_BITS -#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) -{ - if (unlikely(dev && !dma_capable(dev, dma_addr, size))) { - if (!dev->dma_mask) { - dev_err(dev, - "%s: call on device without dma_mask\n", - caller); - return false; - } - - if (*dev->dma_mask >= DMA_BIT_MASK(32)) { - dev_err(dev, - "%s: overflow %pad+%zu of device mask %llx\n", - caller, &dma_addr, size, *dev->dma_mask); - } - return false; - } - return true; -} - -static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size) -{ - 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, - gfp_t gfp, unsigned long attrs) -{ - 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)) - gfp |= GFP_DMA; - if (dev->coherent_dma_mask <= DMA_BIT_MASK(32) && !(gfp & GFP_DMA)) - gfp |= GFP_DMA32; - -again: - /* CMA can be used only in the context which permits sleeping */ - if (gfpflags_allow_blocking(gfp)) { - page = dma_alloc_from_contiguous(dev, count, page_order, gfp); - if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { - dma_release_from_contiguous(dev, page, count); - page = NULL; - } - } - if (!page) - page = alloc_pages_node(dev_to_node(dev), gfp, page_order); - - if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) { - __free_pages(page, page_order); - page = NULL; - - if (IS_ENABLED(CONFIG_ZONE_DMA32) && - dev->coherent_dma_mask < DMA_BIT_MASK(64) && - !(gfp & (GFP_DMA32 | GFP_DMA))) { - gfp |= GFP_DMA32; - goto again; - } - - if (IS_ENABLED(CONFIG_ZONE_DMA) && - dev->coherent_dma_mask < DMA_BIT_MASK(32) && - !(gfp & GFP_DMA)) { - gfp = (gfp & ~GFP_DMA32) | GFP_DMA; - goto again; - } - } - - if (!page) - return NULL; - 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; -} - -/* - * NOTE: this function must never look at the dma_addr argument, because we want - * to be able to use it as a helper for iommu implementations as well. - */ -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, page_order); -} - -dma_addr_t dma_direct_map_page(struct device *dev, struct page *page, - unsigned long offset, size_t size, enum dma_data_direction dir, - unsigned long attrs) -{ - dma_addr_t dma_addr = phys_to_dma(dev, page_to_phys(page)) + offset; - - if (!check_addr(dev, dma_addr, size, __func__)) - return DIRECT_MAPPING_ERROR; - return dma_addr; -} - -int dma_direct_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) = phys_to_dma(dev, sg_phys(sg)); - if (!check_addr(dev, sg_dma_address(sg), sg->length, __func__)) - return 0; - sg_dma_len(sg) = sg->length; - } - - return nents; -} - -int dma_direct_supported(struct device *dev, u64 mask) -{ -#ifdef CONFIG_ZONE_DMA - if (mask < DMA_BIT_MASK(ARCH_ZONE_DMA_BITS)) - return 0; -#else - /* - * Because 32-bit DMA masks are so common we expect every architecture - * to be able to satisfy them - either by not supporting more physical - * memory, or by providing a ZONE_DMA32. If neither is the case, the - * architecture needs to use an IOMMU instead of the direct mapping. - */ - if (mask < DMA_BIT_MASK(32)) - return 0; -#endif - /* - * Various PCI/PCIe bridges have broken support for > 32bit DMA even - * if the device itself might support it. - */ - if (dev->dma_32bit_limit && mask > DMA_BIT_MASK(32)) - return 0; - return 1; -} - -int dma_direct_mapping_error(struct device *dev, dma_addr_t dma_addr) -{ - return dma_addr == DIRECT_MAPPING_ERROR; -} - -const struct dma_map_ops dma_direct_ops = { - .alloc = dma_direct_alloc, - .free = dma_direct_free, - .map_page = dma_direct_map_page, - .map_sg = dma_direct_map_sg, - .dma_supported = dma_direct_supported, - .mapping_error = dma_direct_mapping_error, -}; -EXPORT_SYMBOL(dma_direct_ops); -- cgit v1.2.3