| /* |
| * SWIOTLB-based DMA API implementation |
| * |
| * Copyright (C) 2012 ARM Ltd. |
| * Author: Catalin Marinas <catalin.marinas@arm.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License version 2 as |
| * published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with this program. If not, see <http://www.gnu.org/licenses/>. |
| */ |
| |
| #include <linux/gfp.h> |
| #include <linux/acpi.h> |
| #include <linux/export.h> |
| #include <linux/slab.h> |
| #include <linux/genalloc.h> |
| #include <linux/dma-mapping.h> |
| #include <linux/dma-contiguous.h> |
| #include <linux/vmalloc.h> |
| #include <linux/swiotlb.h> |
| |
| #include <asm/cacheflush.h> |
| |
| static pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot, |
| bool coherent) |
| { |
| if (!coherent || dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs)) |
| return pgprot_writecombine(prot); |
| return prot; |
| } |
| |
| static struct gen_pool *atomic_pool; |
| |
| #define DEFAULT_DMA_COHERENT_POOL_SIZE SZ_256K |
| static size_t atomic_pool_size __initdata = DEFAULT_DMA_COHERENT_POOL_SIZE; |
| |
| static int __init early_coherent_pool(char *p) |
| { |
| atomic_pool_size = memparse(p, &p); |
| return 0; |
| } |
| early_param("coherent_pool", early_coherent_pool); |
| |
| static void *__alloc_from_pool(size_t size, struct page **ret_page, gfp_t flags) |
| { |
| unsigned long val; |
| void *ptr = NULL; |
| |
| if (!atomic_pool) { |
| WARN(1, "coherent pool not initialised!\n"); |
| return NULL; |
| } |
| |
| val = gen_pool_alloc(atomic_pool, size); |
| if (val) { |
| phys_addr_t phys = gen_pool_virt_to_phys(atomic_pool, val); |
| |
| *ret_page = phys_to_page(phys); |
| ptr = (void *)val; |
| memset(ptr, 0, size); |
| } |
| |
| return ptr; |
| } |
| |
| static bool __in_atomic_pool(void *start, size_t size) |
| { |
| return addr_in_gen_pool(atomic_pool, (unsigned long)start, size); |
| } |
| |
| static int __free_from_pool(void *start, size_t size) |
| { |
| if (!__in_atomic_pool(start, size)) |
| return 0; |
| |
| gen_pool_free(atomic_pool, (unsigned long)start, size); |
| |
| return 1; |
| } |
| |
| static void *__dma_alloc_coherent(struct device *dev, size_t size, |
| dma_addr_t *dma_handle, gfp_t flags, |
| struct dma_attrs *attrs) |
| { |
| if (dev == NULL) { |
| WARN_ONCE(1, "Use an actual device structure for DMA allocation\n"); |
| return NULL; |
| } |
| |
| if (IS_ENABLED(CONFIG_ZONE_DMA) && |
| dev->coherent_dma_mask <= DMA_BIT_MASK(32)) |
| flags |= GFP_DMA; |
| if (dev_get_cma_area(dev) && gfpflags_allow_blocking(flags)) { |
| struct page *page; |
| void *addr; |
| |
| page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT, |
| get_order(size)); |
| if (!page) |
| return NULL; |
| |
| *dma_handle = phys_to_dma(dev, page_to_phys(page)); |
| addr = page_address(page); |
| memset(addr, 0, size); |
| return addr; |
| } else { |
| return swiotlb_alloc_coherent(dev, size, dma_handle, flags); |
| } |
| } |
| |
| static void __dma_free_coherent(struct device *dev, size_t size, |
| void *vaddr, dma_addr_t dma_handle, |
| struct dma_attrs *attrs) |
| { |
| bool freed; |
| phys_addr_t paddr = dma_to_phys(dev, dma_handle); |
| |
| if (dev == NULL) { |
| WARN_ONCE(1, "Use an actual device structure for DMA allocation\n"); |
| return; |
| } |
| |
| freed = dma_release_from_contiguous(dev, |
| phys_to_page(paddr), |
| size >> PAGE_SHIFT); |
| if (!freed) |
| swiotlb_free_coherent(dev, size, vaddr, dma_handle); |
| } |
| |
| static void *__dma_alloc(struct device *dev, size_t size, |
| dma_addr_t *dma_handle, gfp_t flags, |
| struct dma_attrs *attrs) |
| { |
| struct page *page; |
| void *ptr, *coherent_ptr; |
| bool coherent = is_device_dma_coherent(dev); |
| pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, false); |
| |
| size = PAGE_ALIGN(size); |
| |
| if (!coherent && !gfpflags_allow_blocking(flags)) { |
| struct page *page = NULL; |
| void *addr = __alloc_from_pool(size, &page, flags); |
| |
| if (addr) |
| *dma_handle = phys_to_dma(dev, page_to_phys(page)); |
| |
| return addr; |
| } |
| |
| ptr = __dma_alloc_coherent(dev, size, dma_handle, flags, attrs); |
| if (!ptr) |
| goto no_mem; |
| |
| /* no need for non-cacheable mapping if coherent */ |
| if (coherent) |
| return ptr; |
| |
| /* remove any dirty cache lines on the kernel alias */ |
| __dma_flush_range(ptr, ptr + size); |
| |
| /* create a coherent mapping */ |
| page = virt_to_page(ptr); |
| coherent_ptr = dma_common_contiguous_remap(page, size, VM_USERMAP, |
| prot, NULL); |
| if (!coherent_ptr) |
| goto no_map; |
| |
| return coherent_ptr; |
| |
| no_map: |
| __dma_free_coherent(dev, size, ptr, *dma_handle, attrs); |
| no_mem: |
| *dma_handle = DMA_ERROR_CODE; |
| return NULL; |
| } |
| |
| static void __dma_free(struct device *dev, size_t size, |
| void *vaddr, dma_addr_t dma_handle, |
| struct dma_attrs *attrs) |
| { |
| void *swiotlb_addr = phys_to_virt(dma_to_phys(dev, dma_handle)); |
| |
| size = PAGE_ALIGN(size); |
| |
| if (!is_device_dma_coherent(dev)) { |
| if (__free_from_pool(vaddr, size)) |
| return; |
| vunmap(vaddr); |
| } |
| __dma_free_coherent(dev, size, swiotlb_addr, dma_handle, attrs); |
| } |
| |
| static dma_addr_t __swiotlb_map_page(struct device *dev, struct page *page, |
| unsigned long offset, size_t size, |
| enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| dma_addr_t dev_addr; |
| |
| dev_addr = swiotlb_map_page(dev, page, offset, size, dir, attrs); |
| if (!is_device_dma_coherent(dev)) |
| __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); |
| |
| return dev_addr; |
| } |
| |
| |
| static void __swiotlb_unmap_page(struct device *dev, dma_addr_t dev_addr, |
| size_t size, enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| if (!is_device_dma_coherent(dev)) |
| __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); |
| swiotlb_unmap_page(dev, dev_addr, size, dir, attrs); |
| } |
| |
| static int __swiotlb_map_sg_attrs(struct device *dev, struct scatterlist *sgl, |
| int nelems, enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| struct scatterlist *sg; |
| int i, ret; |
| |
| ret = swiotlb_map_sg_attrs(dev, sgl, nelems, dir, attrs); |
| if (!is_device_dma_coherent(dev)) |
| for_each_sg(sgl, sg, ret, i) |
| __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), |
| sg->length, dir); |
| |
| return ret; |
| } |
| |
| static void __swiotlb_unmap_sg_attrs(struct device *dev, |
| struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| struct scatterlist *sg; |
| int i; |
| |
| if (!is_device_dma_coherent(dev)) |
| for_each_sg(sgl, sg, nelems, i) |
| __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), |
| sg->length, dir); |
| swiotlb_unmap_sg_attrs(dev, sgl, nelems, dir, attrs); |
| } |
| |
| static void __swiotlb_sync_single_for_cpu(struct device *dev, |
| dma_addr_t dev_addr, size_t size, |
| enum dma_data_direction dir) |
| { |
| if (!is_device_dma_coherent(dev)) |
| __dma_unmap_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); |
| swiotlb_sync_single_for_cpu(dev, dev_addr, size, dir); |
| } |
| |
| static void __swiotlb_sync_single_for_device(struct device *dev, |
| dma_addr_t dev_addr, size_t size, |
| enum dma_data_direction dir) |
| { |
| swiotlb_sync_single_for_device(dev, dev_addr, size, dir); |
| if (!is_device_dma_coherent(dev)) |
| __dma_map_area(phys_to_virt(dma_to_phys(dev, dev_addr)), size, dir); |
| } |
| |
| static void __swiotlb_sync_sg_for_cpu(struct device *dev, |
| struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir) |
| { |
| struct scatterlist *sg; |
| int i; |
| |
| if (!is_device_dma_coherent(dev)) |
| for_each_sg(sgl, sg, nelems, i) |
| __dma_unmap_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), |
| sg->length, dir); |
| swiotlb_sync_sg_for_cpu(dev, sgl, nelems, dir); |
| } |
| |
| static void __swiotlb_sync_sg_for_device(struct device *dev, |
| struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir) |
| { |
| struct scatterlist *sg; |
| int i; |
| |
| swiotlb_sync_sg_for_device(dev, sgl, nelems, dir); |
| if (!is_device_dma_coherent(dev)) |
| for_each_sg(sgl, sg, nelems, i) |
| __dma_map_area(phys_to_virt(dma_to_phys(dev, sg->dma_address)), |
| sg->length, dir); |
| } |
| |
| static int __swiotlb_mmap(struct device *dev, |
| struct vm_area_struct *vma, |
| void *cpu_addr, dma_addr_t dma_addr, size_t size, |
| struct dma_attrs *attrs) |
| { |
| int ret = -ENXIO; |
| unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> |
| PAGE_SHIFT; |
| unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT; |
| unsigned long pfn = dma_to_phys(dev, dma_addr) >> PAGE_SHIFT; |
| unsigned long off = vma->vm_pgoff; |
| |
| vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot, |
| is_device_dma_coherent(dev)); |
| |
| if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) |
| return ret; |
| |
| if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) { |
| ret = remap_pfn_range(vma, vma->vm_start, |
| pfn + off, |
| vma->vm_end - vma->vm_start, |
| vma->vm_page_prot); |
| } |
| |
| return ret; |
| } |
| |
| static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt, |
| void *cpu_addr, dma_addr_t handle, size_t size, |
| struct dma_attrs *attrs) |
| { |
| int ret = sg_alloc_table(sgt, 1, GFP_KERNEL); |
| |
| if (!ret) |
| sg_set_page(sgt->sgl, phys_to_page(dma_to_phys(dev, handle)), |
| PAGE_ALIGN(size), 0); |
| |
| return ret; |
| } |
| |
| static struct dma_map_ops swiotlb_dma_ops = { |
| .alloc = __dma_alloc, |
| .free = __dma_free, |
| .mmap = __swiotlb_mmap, |
| .get_sgtable = __swiotlb_get_sgtable, |
| .map_page = __swiotlb_map_page, |
| .unmap_page = __swiotlb_unmap_page, |
| .map_sg = __swiotlb_map_sg_attrs, |
| .unmap_sg = __swiotlb_unmap_sg_attrs, |
| .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, |
| .dma_supported = swiotlb_dma_supported, |
| .mapping_error = swiotlb_dma_mapping_error, |
| }; |
| |
| static int __init atomic_pool_init(void) |
| { |
| pgprot_t prot = __pgprot(PROT_NORMAL_NC); |
| unsigned long nr_pages = atomic_pool_size >> PAGE_SHIFT; |
| struct page *page; |
| void *addr; |
| unsigned int pool_size_order = get_order(atomic_pool_size); |
| |
| if (dev_get_cma_area(NULL)) |
| page = dma_alloc_from_contiguous(NULL, nr_pages, |
| pool_size_order); |
| else |
| page = alloc_pages(GFP_DMA, pool_size_order); |
| |
| if (page) { |
| int ret; |
| void *page_addr = page_address(page); |
| |
| memset(page_addr, 0, atomic_pool_size); |
| __dma_flush_range(page_addr, page_addr + atomic_pool_size); |
| |
| atomic_pool = gen_pool_create(PAGE_SHIFT, -1); |
| if (!atomic_pool) |
| goto free_page; |
| |
| addr = dma_common_contiguous_remap(page, atomic_pool_size, |
| VM_USERMAP, prot, atomic_pool_init); |
| |
| if (!addr) |
| goto destroy_genpool; |
| |
| ret = gen_pool_add_virt(atomic_pool, (unsigned long)addr, |
| page_to_phys(page), |
| atomic_pool_size, -1); |
| if (ret) |
| goto remove_mapping; |
| |
| gen_pool_set_algo(atomic_pool, |
| gen_pool_first_fit_order_align, |
| (void *)PAGE_SHIFT); |
| |
| pr_info("DMA: preallocated %zu KiB pool for atomic allocations\n", |
| atomic_pool_size / 1024); |
| return 0; |
| } |
| goto out; |
| |
| remove_mapping: |
| dma_common_free_remap(addr, atomic_pool_size, VM_USERMAP); |
| destroy_genpool: |
| gen_pool_destroy(atomic_pool); |
| atomic_pool = NULL; |
| free_page: |
| if (!dma_release_from_contiguous(NULL, page, nr_pages)) |
| __free_pages(page, pool_size_order); |
| out: |
| pr_err("DMA: failed to allocate %zu KiB pool for atomic coherent allocation\n", |
| atomic_pool_size / 1024); |
| return -ENOMEM; |
| } |
| |
| /******************************************** |
| * The following APIs are for dummy DMA ops * |
| ********************************************/ |
| |
| static void *__dummy_alloc(struct device *dev, size_t size, |
| dma_addr_t *dma_handle, gfp_t flags, |
| struct dma_attrs *attrs) |
| { |
| return NULL; |
| } |
| |
| static void __dummy_free(struct device *dev, size_t size, |
| void *vaddr, dma_addr_t dma_handle, |
| struct dma_attrs *attrs) |
| { |
| } |
| |
| static int __dummy_mmap(struct device *dev, |
| struct vm_area_struct *vma, |
| void *cpu_addr, dma_addr_t dma_addr, size_t size, |
| struct dma_attrs *attrs) |
| { |
| return -ENXIO; |
| } |
| |
| static dma_addr_t __dummy_map_page(struct device *dev, struct page *page, |
| unsigned long offset, size_t size, |
| enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| return DMA_ERROR_CODE; |
| } |
| |
| static void __dummy_unmap_page(struct device *dev, dma_addr_t dev_addr, |
| size_t size, enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| } |
| |
| static int __dummy_map_sg(struct device *dev, struct scatterlist *sgl, |
| int nelems, enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| return 0; |
| } |
| |
| static void __dummy_unmap_sg(struct device *dev, |
| struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| } |
| |
| static void __dummy_sync_single(struct device *dev, |
| dma_addr_t dev_addr, size_t size, |
| enum dma_data_direction dir) |
| { |
| } |
| |
| static void __dummy_sync_sg(struct device *dev, |
| struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir) |
| { |
| } |
| |
| static int __dummy_mapping_error(struct device *hwdev, dma_addr_t dma_addr) |
| { |
| return 1; |
| } |
| |
| static int __dummy_dma_supported(struct device *hwdev, u64 mask) |
| { |
| return 0; |
| } |
| |
| struct dma_map_ops dummy_dma_ops = { |
| .alloc = __dummy_alloc, |
| .free = __dummy_free, |
| .mmap = __dummy_mmap, |
| .map_page = __dummy_map_page, |
| .unmap_page = __dummy_unmap_page, |
| .map_sg = __dummy_map_sg, |
| .unmap_sg = __dummy_unmap_sg, |
| .sync_single_for_cpu = __dummy_sync_single, |
| .sync_single_for_device = __dummy_sync_single, |
| .sync_sg_for_cpu = __dummy_sync_sg, |
| .sync_sg_for_device = __dummy_sync_sg, |
| .mapping_error = __dummy_mapping_error, |
| .dma_supported = __dummy_dma_supported, |
| }; |
| EXPORT_SYMBOL(dummy_dma_ops); |
| |
| static int __init arm64_dma_init(void) |
| { |
| return atomic_pool_init(); |
| } |
| arch_initcall(arm64_dma_init); |
| |
| #define PREALLOC_DMA_DEBUG_ENTRIES 4096 |
| |
| static int __init dma_debug_do_init(void) |
| { |
| dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); |
| return 0; |
| } |
| fs_initcall(dma_debug_do_init); |
| |
| |
| #ifdef CONFIG_IOMMU_DMA |
| #include <linux/dma-iommu.h> |
| #include <linux/platform_device.h> |
| #include <linux/amba/bus.h> |
| |
| /* Thankfully, all cache ops are by VA so we can ignore phys here */ |
| static void flush_page(struct device *dev, const void *virt, phys_addr_t phys) |
| { |
| __dma_flush_range(virt, virt + PAGE_SIZE); |
| } |
| |
| static void *__iommu_alloc_attrs(struct device *dev, size_t size, |
| dma_addr_t *handle, gfp_t gfp, |
| struct dma_attrs *attrs) |
| { |
| bool coherent = is_device_dma_coherent(dev); |
| int ioprot = dma_direction_to_prot(DMA_BIDIRECTIONAL, coherent); |
| size_t iosize = size; |
| void *addr; |
| |
| if (WARN(!dev, "cannot create IOMMU mapping for unknown device\n")) |
| return NULL; |
| |
| size = PAGE_ALIGN(size); |
| |
| /* |
| * Some drivers rely on this, and we probably don't want the |
| * possibility of stale kernel data being read by devices anyway. |
| */ |
| gfp |= __GFP_ZERO; |
| |
| if (gfpflags_allow_blocking(gfp)) { |
| struct page **pages; |
| pgprot_t prot = __get_dma_pgprot(attrs, PAGE_KERNEL, coherent); |
| |
| pages = iommu_dma_alloc(dev, iosize, gfp, ioprot, handle, |
| flush_page); |
| if (!pages) |
| return NULL; |
| |
| addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot, |
| __builtin_return_address(0)); |
| if (!addr) |
| iommu_dma_free(dev, pages, iosize, handle); |
| } else { |
| struct page *page; |
| /* |
| * In atomic context we can't remap anything, so we'll only |
| * get the virtually contiguous buffer we need by way of a |
| * physically contiguous allocation. |
| */ |
| if (coherent) { |
| page = alloc_pages(gfp, get_order(size)); |
| addr = page ? page_address(page) : NULL; |
| } else { |
| addr = __alloc_from_pool(size, &page, gfp); |
| } |
| if (!addr) |
| return NULL; |
| |
| *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot); |
| if (iommu_dma_mapping_error(dev, *handle)) { |
| if (coherent) |
| __free_pages(page, get_order(size)); |
| else |
| __free_from_pool(addr, size); |
| addr = NULL; |
| } |
| } |
| return addr; |
| } |
| |
| static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr, |
| dma_addr_t handle, struct dma_attrs *attrs) |
| { |
| size_t iosize = size; |
| |
| size = PAGE_ALIGN(size); |
| /* |
| * @cpu_addr will be one of 3 things depending on how it was allocated: |
| * - A remapped array of pages from iommu_dma_alloc(), for all |
| * non-atomic allocations. |
| * - A non-cacheable alias from the atomic pool, for atomic |
| * allocations by non-coherent devices. |
| * - A normal lowmem address, for atomic allocations by |
| * coherent devices. |
| * Hence how dodgy the below logic looks... |
| */ |
| if (__in_atomic_pool(cpu_addr, size)) { |
| iommu_dma_unmap_page(dev, handle, iosize, 0, NULL); |
| __free_from_pool(cpu_addr, size); |
| } else if (is_vmalloc_addr(cpu_addr)){ |
| struct vm_struct *area = find_vm_area(cpu_addr); |
| |
| if (WARN_ON(!area || !area->pages)) |
| return; |
| iommu_dma_free(dev, area->pages, iosize, &handle); |
| dma_common_free_remap(cpu_addr, size, VM_USERMAP); |
| } else { |
| iommu_dma_unmap_page(dev, handle, iosize, 0, NULL); |
| __free_pages(virt_to_page(cpu_addr), get_order(size)); |
| } |
| } |
| |
| static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, |
| void *cpu_addr, dma_addr_t dma_addr, size_t size, |
| struct dma_attrs *attrs) |
| { |
| struct vm_struct *area; |
| int ret; |
| |
| vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot, |
| is_device_dma_coherent(dev)); |
| |
| if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) |
| return ret; |
| |
| area = find_vm_area(cpu_addr); |
| if (WARN_ON(!area || !area->pages)) |
| return -ENXIO; |
| |
| return iommu_dma_mmap(area->pages, size, vma); |
| } |
| |
| static int __iommu_get_sgtable(struct device *dev, struct sg_table *sgt, |
| void *cpu_addr, dma_addr_t dma_addr, |
| size_t size, struct dma_attrs *attrs) |
| { |
| unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT; |
| struct vm_struct *area = find_vm_area(cpu_addr); |
| |
| if (WARN_ON(!area || !area->pages)) |
| return -ENXIO; |
| |
| return sg_alloc_table_from_pages(sgt, area->pages, count, 0, size, |
| GFP_KERNEL); |
| } |
| |
| static void __iommu_sync_single_for_cpu(struct device *dev, |
| dma_addr_t dev_addr, size_t size, |
| enum dma_data_direction dir) |
| { |
| phys_addr_t phys; |
| |
| if (is_device_dma_coherent(dev)) |
| return; |
| |
| phys = iommu_iova_to_phys(iommu_get_domain_for_dev(dev), dev_addr); |
| __dma_unmap_area(phys_to_virt(phys), size, dir); |
| } |
| |
| static void __iommu_sync_single_for_device(struct device *dev, |
| dma_addr_t dev_addr, size_t size, |
| enum dma_data_direction dir) |
| { |
| phys_addr_t phys; |
| |
| if (is_device_dma_coherent(dev)) |
| return; |
| |
| phys = iommu_iova_to_phys(iommu_get_domain_for_dev(dev), dev_addr); |
| __dma_map_area(phys_to_virt(phys), size, dir); |
| } |
| |
| static dma_addr_t __iommu_map_page(struct device *dev, struct page *page, |
| unsigned long offset, size_t size, |
| enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| bool coherent = is_device_dma_coherent(dev); |
| int prot = dma_direction_to_prot(dir, coherent); |
| dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot); |
| |
| if (!iommu_dma_mapping_error(dev, dev_addr) && |
| !dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) |
| __iommu_sync_single_for_device(dev, dev_addr, size, dir); |
| |
| return dev_addr; |
| } |
| |
| static void __iommu_unmap_page(struct device *dev, dma_addr_t dev_addr, |
| size_t size, enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) |
| __iommu_sync_single_for_cpu(dev, dev_addr, size, dir); |
| |
| iommu_dma_unmap_page(dev, dev_addr, size, dir, attrs); |
| } |
| |
| static void __iommu_sync_sg_for_cpu(struct device *dev, |
| struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir) |
| { |
| struct scatterlist *sg; |
| int i; |
| |
| if (is_device_dma_coherent(dev)) |
| return; |
| |
| for_each_sg(sgl, sg, nelems, i) |
| __dma_unmap_area(sg_virt(sg), sg->length, dir); |
| } |
| |
| static void __iommu_sync_sg_for_device(struct device *dev, |
| struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir) |
| { |
| struct scatterlist *sg; |
| int i; |
| |
| if (is_device_dma_coherent(dev)) |
| return; |
| |
| for_each_sg(sgl, sg, nelems, i) |
| __dma_map_area(sg_virt(sg), sg->length, dir); |
| } |
| |
| static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl, |
| int nelems, enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| bool coherent = is_device_dma_coherent(dev); |
| |
| if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) |
| __iommu_sync_sg_for_device(dev, sgl, nelems, dir); |
| |
| return iommu_dma_map_sg(dev, sgl, nelems, |
| dma_direction_to_prot(dir, coherent)); |
| } |
| |
| static void __iommu_unmap_sg_attrs(struct device *dev, |
| struct scatterlist *sgl, int nelems, |
| enum dma_data_direction dir, |
| struct dma_attrs *attrs) |
| { |
| if (!dma_get_attr(DMA_ATTR_SKIP_CPU_SYNC, attrs)) |
| __iommu_sync_sg_for_cpu(dev, sgl, nelems, dir); |
| |
| iommu_dma_unmap_sg(dev, sgl, nelems, dir, attrs); |
| } |
| |
| static struct dma_map_ops iommu_dma_ops = { |
| .alloc = __iommu_alloc_attrs, |
| .free = __iommu_free_attrs, |
| .mmap = __iommu_mmap_attrs, |
| .get_sgtable = __iommu_get_sgtable, |
| .map_page = __iommu_map_page, |
| .unmap_page = __iommu_unmap_page, |
| .map_sg = __iommu_map_sg_attrs, |
| .unmap_sg = __iommu_unmap_sg_attrs, |
| .sync_single_for_cpu = __iommu_sync_single_for_cpu, |
| .sync_single_for_device = __iommu_sync_single_for_device, |
| .sync_sg_for_cpu = __iommu_sync_sg_for_cpu, |
| .sync_sg_for_device = __iommu_sync_sg_for_device, |
| .dma_supported = iommu_dma_supported, |
| .mapping_error = iommu_dma_mapping_error, |
| }; |
| |
| /* |
| * TODO: Right now __iommu_setup_dma_ops() gets called too early to do |
| * everything it needs to - the device is only partially created and the |
| * IOMMU driver hasn't seen it yet, so it can't have a group. Thus we |
| * need this delayed attachment dance. Once IOMMU probe ordering is sorted |
| * to move the arch_setup_dma_ops() call later, all the notifier bits below |
| * become unnecessary, and will go away. |
| */ |
| struct iommu_dma_notifier_data { |
| struct list_head list; |
| struct device *dev; |
| const struct iommu_ops *ops; |
| u64 dma_base; |
| u64 size; |
| }; |
| static LIST_HEAD(iommu_dma_masters); |
| static DEFINE_MUTEX(iommu_dma_notifier_lock); |
| |
| /* |
| * Temporarily "borrow" a domain feature flag to to tell if we had to resort |
| * to creating our own domain here, in case we need to clean it up again. |
| */ |
| #define __IOMMU_DOMAIN_FAKE_DEFAULT (1U << 31) |
| |
| static bool do_iommu_attach(struct device *dev, const struct iommu_ops *ops, |
| u64 dma_base, u64 size) |
| { |
| struct iommu_domain *domain = iommu_get_domain_for_dev(dev); |
| |
| /* |
| * Best case: The device is either part of a group which was |
| * already attached to a domain in a previous call, or it's |
| * been put in a default DMA domain by the IOMMU core. |
| */ |
| if (!domain) { |
| /* |
| * Urgh. The IOMMU core isn't going to do default domains |
| * for non-PCI devices anyway, until it has some means of |
| * abstracting the entirely implementation-specific |
| * sideband data/SoC topology/unicorn dust that may or |
| * may not differentiate upstream masters. |
| * So until then, HORRIBLE HACKS! |
| */ |
| domain = ops->domain_alloc(IOMMU_DOMAIN_DMA); |
| if (!domain) |
| goto out_no_domain; |
| |
| domain->ops = ops; |
| domain->type = IOMMU_DOMAIN_DMA | __IOMMU_DOMAIN_FAKE_DEFAULT; |
| |
| if (iommu_attach_device(domain, dev)) |
| goto out_put_domain; |
| } |
| |
| if (iommu_dma_init_domain(domain, dma_base, size)) |
| goto out_detach; |
| |
| dev->archdata.dma_ops = &iommu_dma_ops; |
| return true; |
| |
| out_detach: |
| iommu_detach_device(domain, dev); |
| out_put_domain: |
| if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT) |
| iommu_domain_free(domain); |
| out_no_domain: |
| pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n", |
| dev_name(dev)); |
| return false; |
| } |
| |
| static void queue_iommu_attach(struct device *dev, const struct iommu_ops *ops, |
| u64 dma_base, u64 size) |
| { |
| struct iommu_dma_notifier_data *iommudata; |
| |
| iommudata = kzalloc(sizeof(*iommudata), GFP_KERNEL); |
| if (!iommudata) |
| return; |
| |
| iommudata->dev = dev; |
| iommudata->ops = ops; |
| iommudata->dma_base = dma_base; |
| iommudata->size = size; |
| |
| mutex_lock(&iommu_dma_notifier_lock); |
| list_add(&iommudata->list, &iommu_dma_masters); |
| mutex_unlock(&iommu_dma_notifier_lock); |
| } |
| |
| static int __iommu_attach_notifier(struct notifier_block *nb, |
| unsigned long action, void *data) |
| { |
| struct iommu_dma_notifier_data *master, *tmp; |
| |
| if (action != BUS_NOTIFY_ADD_DEVICE) |
| return 0; |
| |
| mutex_lock(&iommu_dma_notifier_lock); |
| list_for_each_entry_safe(master, tmp, &iommu_dma_masters, list) { |
| if (do_iommu_attach(master->dev, master->ops, |
| master->dma_base, master->size)) { |
| list_del(&master->list); |
| kfree(master); |
| } |
| } |
| mutex_unlock(&iommu_dma_notifier_lock); |
| return 0; |
| } |
| |
| static int __init register_iommu_dma_ops_notifier(struct bus_type *bus) |
| { |
| struct notifier_block *nb = kzalloc(sizeof(*nb), GFP_KERNEL); |
| int ret; |
| |
| if (!nb) |
| return -ENOMEM; |
| /* |
| * The device must be attached to a domain before the driver probe |
| * routine gets a chance to start allocating DMA buffers. However, |
| * the IOMMU driver also needs a chance to configure the iommu_group |
| * via its add_device callback first, so we need to make the attach |
| * happen between those two points. Since the IOMMU core uses a bus |
| * notifier with default priority for add_device, do the same but |
| * with a lower priority to ensure the appropriate ordering. |
| */ |
| nb->notifier_call = __iommu_attach_notifier; |
| nb->priority = -100; |
| |
| ret = bus_register_notifier(bus, nb); |
| if (ret) { |
| pr_warn("Failed to register DMA domain notifier; IOMMU DMA ops unavailable on bus '%s'\n", |
| bus->name); |
| kfree(nb); |
| } |
| return ret; |
| } |
| |
| static int __init __iommu_dma_init(void) |
| { |
| int ret; |
| |
| ret = iommu_dma_init(); |
| if (!ret) |
| ret = register_iommu_dma_ops_notifier(&platform_bus_type); |
| if (!ret) |
| ret = register_iommu_dma_ops_notifier(&amba_bustype); |
| #ifdef CONFIG_PCI |
| if (!ret) |
| ret = register_iommu_dma_ops_notifier(&pci_bus_type); |
| #endif |
| |
| /* handle devices queued before this arch_initcall */ |
| if (!ret) |
| __iommu_attach_notifier(NULL, BUS_NOTIFY_ADD_DEVICE, NULL); |
| return ret; |
| } |
| arch_initcall(__iommu_dma_init); |
| |
| static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, |
| const struct iommu_ops *ops) |
| { |
| struct iommu_group *group; |
| |
| if (!ops) |
| return; |
| /* |
| * TODO: As a concession to the future, we're ready to handle being |
| * called both early and late (i.e. after bus_add_device). Once all |
| * the platform bus code is reworked to call us late and the notifier |
| * junk above goes away, move the body of do_iommu_attach here. |
| */ |
| group = iommu_group_get(dev); |
| if (group) { |
| do_iommu_attach(dev, ops, dma_base, size); |
| iommu_group_put(group); |
| } else { |
| queue_iommu_attach(dev, ops, dma_base, size); |
| } |
| } |
| |
| void arch_teardown_dma_ops(struct device *dev) |
| { |
| struct iommu_domain *domain = iommu_get_domain_for_dev(dev); |
| |
| if (domain) { |
| iommu_detach_device(domain, dev); |
| if (domain->type & __IOMMU_DOMAIN_FAKE_DEFAULT) |
| iommu_domain_free(domain); |
| } |
| |
| dev->archdata.dma_ops = NULL; |
| } |
| |
| #else |
| |
| static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, |
| struct iommu_ops *iommu) |
| { } |
| |
| #endif /* CONFIG_IOMMU_DMA */ |
| |
| void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size, |
| struct iommu_ops *iommu, bool coherent) |
| { |
| if (!dev->archdata.dma_ops) |
| dev->archdata.dma_ops = &swiotlb_dma_ops; |
| |
| dev->archdata.dma_coherent = coherent; |
| __iommu_setup_dma_ops(dev, dma_base, size, iommu); |
| } |