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- // SPDX-License-Identifier: GPL-2.0
- /*
- * Copyright (C) 2018-2020 Christoph Hellwig.
- *
- * DMA operations that map physical memory directly without using an IOMMU.
- */
- #include <linux/memblock.h> /* for max_pfn */
- #include <linux/export.h>
- #include <linux/mm.h>
- #include <linux/dma-map-ops.h>
- #include <linux/scatterlist.h>
- #include <linux/pfn.h>
- #include <linux/vmalloc.h>
- #include <linux/set_memory.h>
- #include <linux/slab.h>
- #include "direct.h"
- /*
- * Most architectures use ZONE_DMA for the first 16 Megabytes, but some use
- * it for entirely different regions. In that case the arch code needs to
- * override the variable below for dma-direct to work properly.
- */
- unsigned int zone_dma_bits __ro_after_init = 24;
- static inline dma_addr_t phys_to_dma_direct(struct device *dev,
- phys_addr_t phys)
- {
- if (force_dma_unencrypted(dev))
- return phys_to_dma_unencrypted(dev, phys);
- return phys_to_dma(dev, phys);
- }
- static inline struct page *dma_direct_to_page(struct device *dev,
- dma_addr_t dma_addr)
- {
- return pfn_to_page(PHYS_PFN(dma_to_phys(dev, dma_addr)));
- }
- u64 dma_direct_get_required_mask(struct device *dev)
- {
- phys_addr_t phys = (phys_addr_t)(max_pfn - 1) << PAGE_SHIFT;
- u64 max_dma = phys_to_dma_direct(dev, phys);
- return (1ULL << (fls64(max_dma) - 1)) * 2 - 1;
- }
- EXPORT_SYMBOL_GPL(dma_direct_get_required_mask);
- static gfp_t dma_direct_optimal_gfp_mask(struct device *dev, u64 dma_mask,
- u64 *phys_limit)
- {
- u64 dma_limit = min_not_zero(dma_mask, dev->bus_dma_limit);
- /*
- * Optimistically try the zone that the physical address mask falls
- * into first. If that returns memory that isn't actually addressable
- * we will fallback to the next lower zone and try again.
- *
- * Note that GFP_DMA32 and GFP_DMA are no ops without the corresponding
- * zones.
- */
- *phys_limit = dma_to_phys(dev, dma_limit);
- if (*phys_limit <= DMA_BIT_MASK(zone_dma_bits))
- return GFP_DMA;
- if (*phys_limit <= DMA_BIT_MASK(32) &&
- !zone_dma32_are_empty())
- return GFP_DMA32;
- return 0;
- }
- static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
- {
- dma_addr_t dma_addr = phys_to_dma_direct(dev, phys);
- if (dma_addr == DMA_MAPPING_ERROR)
- return false;
- return dma_addr + size - 1 <=
- min_not_zero(dev->coherent_dma_mask, dev->bus_dma_limit);
- }
- static struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
- gfp_t gfp)
- {
- int node = dev_to_node(dev);
- struct page *page = NULL;
- u64 phys_limit;
- WARN_ON_ONCE(!PAGE_ALIGNED(size));
- gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
- &phys_limit);
- page = dma_alloc_contiguous(dev, size, gfp);
- if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
- dma_free_contiguous(dev, page, size);
- page = NULL;
- }
- again:
- if (!page)
- page = alloc_pages_node(node, gfp, get_order(size));
- if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
- dma_free_contiguous(dev, page, size);
- page = NULL;
- if (IS_ENABLED(CONFIG_ZONE_DMA32) &&
- phys_limit < DMA_BIT_MASK(64) &&
- !(gfp & (GFP_DMA32 | GFP_DMA)) &&
- !zone_dma32_are_empty()) {
- gfp |= GFP_DMA32;
- goto again;
- }
- if (IS_ENABLED(CONFIG_ZONE_DMA) && !(gfp & GFP_DMA)) {
- gfp = (gfp & ~GFP_DMA32) | GFP_DMA;
- goto again;
- }
- }
- return page;
- }
- static void *dma_direct_alloc_from_pool(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t gfp)
- {
- struct page *page;
- u64 phys_mask;
- void *ret;
- gfp |= dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
- &phys_mask);
- page = dma_alloc_from_pool(dev, size, &ret, gfp, dma_coherent_ok);
- if (!page)
- return NULL;
- *dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
- return ret;
- }
- void *dma_direct_alloc(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
- {
- struct page *page;
- void *ret;
- int err;
- size = PAGE_ALIGN(size);
- if (attrs & DMA_ATTR_NO_WARN)
- gfp |= __GFP_NOWARN;
- if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&
- !force_dma_unencrypted(dev)) {
- page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO);
- if (!page)
- return NULL;
- /* remove any dirty cache lines on the kernel alias */
- if (!PageHighMem(page))
- arch_dma_prep_coherent(page, size);
- *dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
- /* return the page pointer as the opaque cookie */
- return page;
- }
- if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
- !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
- !dev_is_dma_coherent(dev))
- return arch_dma_alloc(dev, size, dma_handle, gfp, attrs);
- /*
- * Remapping or decrypting memory may block. If either is required and
- * we can't block, allocate the memory from the atomic pools.
- */
- if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
- !gfpflags_allow_blocking(gfp) &&
- (force_dma_unencrypted(dev) ||
- (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && !dev_is_dma_coherent(dev))))
- return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
- /* we always manually zero the memory once we are done */
- page = __dma_direct_alloc_pages(dev, size, gfp & ~__GFP_ZERO);
- if (!page)
- return NULL;
- if ((IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
- !dev_is_dma_coherent(dev)) ||
- (IS_ENABLED(CONFIG_DMA_REMAP) && PageHighMem(page))) {
- /* remove any dirty cache lines on the kernel alias */
- arch_dma_prep_coherent(page, size);
- /* create a coherent mapping */
- ret = dma_common_contiguous_remap(page, size,
- dma_pgprot(dev, PAGE_KERNEL, attrs),
- __builtin_return_address(0));
- if (!ret)
- goto out_free_pages;
- if (force_dma_unencrypted(dev)) {
- err = set_memory_decrypted((unsigned long)ret,
- 1 << get_order(size));
- if (err)
- goto out_free_pages;
- }
- memset(ret, 0, size);
- goto done;
- }
- if (PageHighMem(page)) {
- /*
- * Depending on the cma= arguments and per-arch setup
- * dma_alloc_contiguous could return highmem pages.
- * Without remapping there is no way to return them here,
- * so log an error and fail.
- */
- dev_info(dev, "Rejecting highmem page from CMA.\n");
- goto out_free_pages;
- }
- ret = page_address(page);
- if (force_dma_unencrypted(dev)) {
- err = set_memory_decrypted((unsigned long)ret,
- 1 << get_order(size));
- if (err)
- goto out_free_pages;
- }
- memset(ret, 0, size);
- if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
- !dev_is_dma_coherent(dev)) {
- arch_dma_prep_coherent(page, size);
- ret = arch_dma_set_uncached(ret, size);
- if (IS_ERR(ret))
- goto out_encrypt_pages;
- }
- done:
- *dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
- return ret;
- out_encrypt_pages:
- if (force_dma_unencrypted(dev)) {
- err = set_memory_encrypted((unsigned long)page_address(page),
- 1 << get_order(size));
- /* If memory cannot be re-encrypted, it must be leaked */
- if (err)
- return NULL;
- }
- out_free_pages:
- dma_free_contiguous(dev, page, size);
- return NULL;
- }
- void dma_direct_free(struct device *dev, size_t size,
- void *cpu_addr, dma_addr_t dma_addr, unsigned long attrs)
- {
- unsigned int page_order = get_order(size);
- if ((attrs & DMA_ATTR_NO_KERNEL_MAPPING) &&
- !force_dma_unencrypted(dev)) {
- /* cpu_addr is a struct page cookie, not a kernel address */
- dma_free_contiguous(dev, cpu_addr, size);
- return;
- }
- if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&
- !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
- !dev_is_dma_coherent(dev)) {
- arch_dma_free(dev, size, cpu_addr, dma_addr, attrs);
- return;
- }
- /* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */
- if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
- dma_free_from_pool(dev, cpu_addr, PAGE_ALIGN(size)))
- return;
- if (force_dma_unencrypted(dev))
- set_memory_encrypted((unsigned long)cpu_addr, 1 << page_order);
- if (IS_ENABLED(CONFIG_DMA_REMAP) && is_vmalloc_addr(cpu_addr))
- vunmap(cpu_addr);
- else if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_CLEAR_UNCACHED))
- arch_dma_clear_uncached(cpu_addr, size);
- dma_free_contiguous(dev, dma_direct_to_page(dev, dma_addr), size);
- }
- struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
- dma_addr_t *dma_handle, enum dma_data_direction dir, gfp_t gfp)
- {
- struct page *page;
- void *ret;
- if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
- force_dma_unencrypted(dev) && !gfpflags_allow_blocking(gfp))
- return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
- page = __dma_direct_alloc_pages(dev, size, gfp);
- if (!page)
- return NULL;
- if (PageHighMem(page)) {
- /*
- * Depending on the cma= arguments and per-arch setup
- * dma_alloc_contiguous could return highmem pages.
- * Without remapping there is no way to return them here,
- * so log an error and fail.
- */
- dev_info(dev, "Rejecting highmem page from CMA.\n");
- goto out_free_pages;
- }
- ret = page_address(page);
- if (force_dma_unencrypted(dev)) {
- if (set_memory_decrypted((unsigned long)ret,
- 1 << get_order(size)))
- goto out_free_pages;
- }
- memset(ret, 0, size);
- *dma_handle = phys_to_dma_direct(dev, page_to_phys(page));
- return page;
- out_free_pages:
- dma_free_contiguous(dev, page, size);
- return NULL;
- }
- EXPORT_SYMBOL_GPL(dma_direct_alloc);
- void dma_direct_free_pages(struct device *dev, size_t size,
- struct page *page, dma_addr_t dma_addr,
- enum dma_data_direction dir)
- {
- unsigned int page_order = get_order(size);
- void *vaddr = page_address(page);
- /* If cpu_addr is not from an atomic pool, dma_free_from_pool() fails */
- if (IS_ENABLED(CONFIG_DMA_COHERENT_POOL) &&
- dma_free_from_pool(dev, vaddr, size))
- return;
- if (force_dma_unencrypted(dev))
- set_memory_encrypted((unsigned long)vaddr, 1 << page_order);
- dma_free_contiguous(dev, page, size);
- }
- EXPORT_SYMBOL_GPL(dma_direct_free);
- #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_DEVICE) || \
- defined(CONFIG_SWIOTLB)
- void dma_direct_sync_sg_for_device(struct device *dev,
- struct scatterlist *sgl, int nents, enum dma_data_direction dir)
- {
- struct scatterlist *sg;
- int i;
- for_each_sg(sgl, sg, nents, i) {
- phys_addr_t paddr = dma_to_phys(dev, sg_dma_address(sg));
- if (unlikely(is_swiotlb_buffer(paddr)))
- swiotlb_tbl_sync_single(dev, paddr, sg->length,
- dir, SYNC_FOR_DEVICE);
- if (!dev_is_dma_coherent(dev))
- arch_sync_dma_for_device(paddr, sg->length,
- dir);
- }
- }
- #endif
- #if defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU) || \
- defined(CONFIG_ARCH_HAS_SYNC_DMA_FOR_CPU_ALL) || \
- defined(CONFIG_SWIOTLB)
- void dma_direct_sync_sg_for_cpu(struct device *dev,
- struct scatterlist *sgl, int nents, enum dma_data_direction dir)
- {
- struct scatterlist *sg;
- int i;
- for_each_sg(sgl, sg, nents, i) {
- phys_addr_t paddr = dma_to_phys(dev, sg_dma_address(sg));
- if (!dev_is_dma_coherent(dev))
- arch_sync_dma_for_cpu(paddr, sg->length, dir);
- if (unlikely(is_swiotlb_buffer(paddr)))
- swiotlb_tbl_sync_single(dev, paddr, sg->length, dir,
- SYNC_FOR_CPU);
- if (dir == DMA_FROM_DEVICE)
- arch_dma_mark_clean(paddr, sg->length);
- }
- if (!dev_is_dma_coherent(dev))
- arch_sync_dma_for_cpu_all();
- }
- void dma_direct_unmap_sg(struct device *dev, struct scatterlist *sgl,
- int nents, enum dma_data_direction dir, unsigned long attrs)
- {
- struct scatterlist *sg;
- int i;
- for_each_sg(sgl, sg, nents, i)
- dma_direct_unmap_page(dev, sg->dma_address, sg_dma_len(sg), dir,
- attrs);
- }
- #endif
- 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) {
- sg->dma_address = dma_direct_map_page(dev, sg_page(sg),
- sg->offset, sg->length, dir, attrs);
- if (sg->dma_address == DMA_MAPPING_ERROR)
- goto out_unmap;
- sg_dma_len(sg) = sg->length;
- }
- return nents;
- out_unmap:
- dma_direct_unmap_sg(dev, sgl, i, dir, attrs | DMA_ATTR_SKIP_CPU_SYNC);
- return 0;
- }
- dma_addr_t dma_direct_map_resource(struct device *dev, phys_addr_t paddr,
- size_t size, enum dma_data_direction dir, unsigned long attrs)
- {
- dma_addr_t dma_addr = paddr;
- if (unlikely(!dma_capable(dev, dma_addr, size, false))) {
- dev_err_once(dev,
- "DMA addr %pad+%zu overflow (mask %llx, bus limit %llx).\n",
- &dma_addr, size, *dev->dma_mask, dev->bus_dma_limit);
- WARN_ON_ONCE(1);
- return DMA_MAPPING_ERROR;
- }
- return dma_addr;
- }
- int dma_direct_get_sgtable(struct device *dev, struct sg_table *sgt,
- void *cpu_addr, dma_addr_t dma_addr, size_t size,
- unsigned long attrs)
- {
- struct page *page = dma_direct_to_page(dev, dma_addr);
- int ret;
- ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
- if (!ret)
- sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
- return ret;
- }
- bool dma_direct_can_mmap(struct device *dev)
- {
- return dev_is_dma_coherent(dev) ||
- IS_ENABLED(CONFIG_DMA_NONCOHERENT_MMAP);
- }
- int dma_direct_mmap(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr, size_t size,
- unsigned long attrs)
- {
- unsigned long user_count = vma_pages(vma);
- unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- unsigned long pfn = PHYS_PFN(dma_to_phys(dev, dma_addr));
- int ret = -ENXIO;
- vma->vm_page_prot = dma_pgprot(dev, vma->vm_page_prot, attrs);
- if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
- return ret;
- if (vma->vm_pgoff >= count || user_count > count - vma->vm_pgoff)
- return -ENXIO;
- return remap_pfn_range(vma, vma->vm_start, pfn + vma->vm_pgoff,
- user_count << PAGE_SHIFT, vma->vm_page_prot);
- }
- int dma_direct_supported(struct device *dev, u64 mask)
- {
- u64 min_mask = (max_pfn - 1) << PAGE_SHIFT;
- /*
- * 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 1;
- /*
- * This check needs to be against the actual bit mask value, so use
- * phys_to_dma_unencrypted() here so that the SME encryption mask isn't
- * part of the check.
- */
- if (IS_ENABLED(CONFIG_ZONE_DMA))
- min_mask = min_t(u64, min_mask, DMA_BIT_MASK(zone_dma_bits));
- return mask >= phys_to_dma_unencrypted(dev, min_mask);
- }
- size_t dma_direct_max_mapping_size(struct device *dev)
- {
- /* If SWIOTLB is active, use its maximum mapping size */
- if (is_swiotlb_active() &&
- (dma_addressing_limited(dev) || swiotlb_force == SWIOTLB_FORCE))
- return swiotlb_max_mapping_size(dev);
- return SIZE_MAX;
- }
- bool dma_direct_need_sync(struct device *dev, dma_addr_t dma_addr)
- {
- return !dev_is_dma_coherent(dev) ||
- is_swiotlb_buffer(dma_to_phys(dev, dma_addr));
- }
- /**
- * dma_direct_set_offset - Assign scalar offset for a single DMA range.
- * @dev: device pointer; needed to "own" the alloced memory.
- * @cpu_start: beginning of memory region covered by this offset.
- * @dma_start: beginning of DMA/PCI region covered by this offset.
- * @size: size of the region.
- *
- * This is for the simple case of a uniform offset which cannot
- * be discovered by "dma-ranges".
- *
- * It returns -ENOMEM if out of memory, -EINVAL if a map
- * already exists, 0 otherwise.
- *
- * Note: any call to this from a driver is a bug. The mapping needs
- * to be described by the device tree or other firmware interfaces.
- */
- int dma_direct_set_offset(struct device *dev, phys_addr_t cpu_start,
- dma_addr_t dma_start, u64 size)
- {
- struct bus_dma_region *map;
- u64 offset = (u64)cpu_start - (u64)dma_start;
- if (dev->dma_range_map) {
- dev_err(dev, "attempt to add DMA range to existing map\n");
- return -EINVAL;
- }
- if (!offset)
- return 0;
- map = kcalloc(2, sizeof(*map), GFP_KERNEL);
- if (!map)
- return -ENOMEM;
- map[0].cpu_start = cpu_start;
- map[0].dma_start = dma_start;
- map[0].offset = offset;
- map[0].size = size;
- dev->dma_range_map = map;
- return 0;
- }
- EXPORT_SYMBOL_GPL(dma_direct_set_offset);
|