// SPDX-License-Identifier: GPL-2.0-only
/*
- * SWIOTLB-based DMA API implementation
- *
* Copyright (C) 2012 ARM Ltd.
* Author: Catalin Marinas <catalin.marinas@arm.com>
*/
#include <linux/gfp.h>
-#include <linux/acpi.h>
-#include <linux/memblock.h>
#include <linux/cache.h>
-#include <linux/export.h>
-#include <linux/slab.h>
-#include <linux/genalloc.h>
-#include <linux/dma-direct.h>
#include <linux/dma-noncoherent.h>
-#include <linux/dma-contiguous.h>
-#include <linux/vmalloc.h>
-#include <linux/swiotlb.h>
-#include <linux/pci.h>
+#include <linux/dma-iommu.h>
#include <asm/cacheflush.h>
__dma_flush_area(page_address(page), size);
}
-#ifdef CONFIG_IOMMU_DMA
-static int __swiotlb_get_sgtable_page(struct sg_table *sgt,
- struct page *page, size_t size)
-{
- int ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
-
- if (!ret)
- sg_set_page(sgt->sgl, page, PAGE_ALIGN(size), 0);
-
- return ret;
-}
-
-static int __swiotlb_mmap_pfn(struct vm_area_struct *vma,
- unsigned long pfn, size_t size)
-{
- int ret = -ENXIO;
- unsigned long nr_vma_pages = vma_pages(vma);
- unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
- unsigned long off = vma->vm_pgoff;
-
- 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;
-}
-#endif /* CONFIG_IOMMU_DMA */
-
static int __init arm64_dma_init(void)
{
return dma_atomic_pool_init(GFP_DMA32, __pgprot(PROT_NORMAL_NC));
arch_initcall(arm64_dma_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_area(virt, PAGE_SIZE);
-}
-
-static void *__iommu_alloc_attrs(struct device *dev, size_t size,
- dma_addr_t *handle, gfp_t gfp,
- unsigned long attrs)
-{
- bool coherent = dev_is_dma_coherent(dev);
- int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
- 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 *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 = dma_alloc_from_pool(size, &page, gfp);
- }
- if (!addr)
- return NULL;
-
- *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot);
- if (*handle == DMA_MAPPING_ERROR) {
- if (coherent)
- __free_pages(page, get_order(size));
- else
- dma_free_from_pool(addr, size);
- addr = NULL;
- }
- } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
- struct page *page;
-
- page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
- get_order(size), gfp & __GFP_NOWARN);
- if (!page)
- return NULL;
-
- *handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot);
- if (*handle == DMA_MAPPING_ERROR) {
- dma_release_from_contiguous(dev, page,
- size >> PAGE_SHIFT);
- return NULL;
- }
- addr = dma_common_contiguous_remap(page, size, VM_USERMAP,
- prot,
- __builtin_return_address(0));
- if (addr) {
- if (!coherent)
- __dma_flush_area(page_to_virt(page), iosize);
- memset(addr, 0, size);
- } else {
- iommu_dma_unmap_page(dev, *handle, iosize, 0, attrs);
- dma_release_from_contiguous(dev, page,
- size >> PAGE_SHIFT);
- }
- } else {
- pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
- struct page **pages;
-
- pages = iommu_dma_alloc(dev, iosize, gfp, attrs, 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);
- }
- return addr;
-}
-
-static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
- dma_addr_t handle, unsigned long attrs)
-{
- size_t iosize = size;
-
- size = PAGE_ALIGN(size);
- /*
- * @cpu_addr will be one of 4 things depending on how it was allocated:
- * - A remapped array of pages for contiguous allocations.
- * - 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 (dma_in_atomic_pool(cpu_addr, size)) {
- iommu_dma_unmap_page(dev, handle, iosize, 0, 0);
- dma_free_from_pool(cpu_addr, size);
- } else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- struct page *page = vmalloc_to_page(cpu_addr);
-
- iommu_dma_unmap_page(dev, handle, iosize, 0, attrs);
- dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
- dma_common_free_remap(cpu_addr, size, VM_USERMAP);
- } 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, 0);
- __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,
- unsigned long attrs)
-{
- struct vm_struct *area;
- int ret;
-
- vma->vm_page_prot = arch_dma_mmap_pgprot(dev, vma->vm_page_prot, attrs);
-
- if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
- return ret;
-
- if (!is_vmalloc_addr(cpu_addr)) {
- unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
- return __swiotlb_mmap_pfn(vma, pfn, size);
- }
-
- if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- /*
- * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
- * hence in the vmalloc space.
- */
- unsigned long pfn = vmalloc_to_pfn(cpu_addr);
- return __swiotlb_mmap_pfn(vma, pfn, size);
- }
-
- 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, unsigned long attrs)
-{
- unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- struct vm_struct *area = find_vm_area(cpu_addr);
-
- if (!is_vmalloc_addr(cpu_addr)) {
- struct page *page = virt_to_page(cpu_addr);
- return __swiotlb_get_sgtable_page(sgt, page, size);
- }
-
- if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
- /*
- * DMA_ATTR_FORCE_CONTIGUOUS allocations are always remapped,
- * hence in the vmalloc space.
- */
- struct page *page = vmalloc_to_page(cpu_addr);
- return __swiotlb_get_sgtable_page(sgt, page, size);
- }
-
- 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 (dev_is_dma_coherent(dev))
- return;
-
- phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dev_addr);
- arch_sync_dma_for_cpu(dev, 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 (dev_is_dma_coherent(dev))
- return;
-
- phys = iommu_iova_to_phys(iommu_get_dma_domain(dev), dev_addr);
- arch_sync_dma_for_device(dev, 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,
- unsigned long attrs)
-{
- bool coherent = dev_is_dma_coherent(dev);
- int prot = dma_info_to_prot(dir, coherent, attrs);
- dma_addr_t dev_addr = iommu_dma_map_page(dev, page, offset, size, prot);
-
- if (!coherent && !(attrs & DMA_ATTR_SKIP_CPU_SYNC) &&
- dev_addr != DMA_MAPPING_ERROR)
- __dma_map_area(page_address(page) + offset, 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,
- unsigned long attrs)
-{
- if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
- __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 (dev_is_dma_coherent(dev))
- return;
-
- for_each_sg(sgl, sg, nelems, i)
- arch_sync_dma_for_cpu(dev, sg_phys(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 (dev_is_dma_coherent(dev))
- return;
-
- for_each_sg(sgl, sg, nelems, i)
- arch_sync_dma_for_device(dev, sg_phys(sg), sg->length, dir);
-}
-
-static int __iommu_map_sg_attrs(struct device *dev, struct scatterlist *sgl,
- int nelems, enum dma_data_direction dir,
- unsigned long attrs)
-{
- bool coherent = dev_is_dma_coherent(dev);
-
- if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
- __iommu_sync_sg_for_device(dev, sgl, nelems, dir);
-
- return iommu_dma_map_sg(dev, sgl, nelems,
- dma_info_to_prot(dir, coherent, attrs));
-}
-
-static void __iommu_unmap_sg_attrs(struct device *dev,
- struct scatterlist *sgl, int nelems,
- enum dma_data_direction dir,
- unsigned long attrs)
-{
- if ((attrs & DMA_ATTR_SKIP_CPU_SYNC) == 0)
- __iommu_sync_sg_for_cpu(dev, sgl, nelems, dir);
-
- iommu_dma_unmap_sg(dev, sgl, nelems, dir, attrs);
-}
-
-static const 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,
- .map_resource = iommu_dma_map_resource,
- .unmap_resource = iommu_dma_unmap_resource,
-};
-
-static int __init __iommu_dma_init(void)
-{
- return iommu_dma_init();
-}
-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_domain *domain;
-
- if (!ops)
- return;
-
- /*
- * The IOMMU core code allocates the default DMA domain, which the
- * underlying IOMMU driver needs to support via the dma-iommu layer.
- */
- domain = iommu_get_domain_for_dev(dev);
-
- if (!domain)
- goto out_err;
-
- if (domain->type == IOMMU_DOMAIN_DMA) {
- if (iommu_dma_init_domain(domain, dma_base, size, dev))
- goto out_err;
-
- dev->dma_ops = &iommu_dma_ops;
- }
-
- return;
-
-out_err:
- pr_warn("Failed to set up IOMMU for device %s; retaining platform DMA ops\n",
- dev_name(dev));
-}
-
void arch_teardown_dma_ops(struct device *dev)
{
dev->dma_ops = NULL;
}
-
-#else
-
-static void __iommu_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
- const struct iommu_ops *iommu)
-{ }
-
-#endif /* CONFIG_IOMMU_DMA */
+#endif
void arch_setup_dma_ops(struct device *dev, u64 dma_base, u64 size,
const struct iommu_ops *iommu, bool coherent)
ARCH_DMA_MINALIGN, cls);
dev->dma_coherent = coherent;
- __iommu_setup_dma_ops(dev, dma_base, size, iommu);
+ if (iommu)
+ iommu_setup_dma_ops(dev, dma_base, size);
#ifdef CONFIG_XEN
if (xen_initial_domain())
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