dma-mapping: introduce a dma_common_find_pages helper
A helper to find the backing page array based on a virtual address. This also ensures we do the same vm_flags check everywhere instead of slightly different or missing ones in a few places. Signed-off-by: Christoph Hellwig <hch@lst.de>
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@ -1439,18 +1439,13 @@ static struct page **__atomic_get_pages(void *addr)
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static struct page **__iommu_get_pages(void *cpu_addr, unsigned long attrs)
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{
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struct vm_struct *area;
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if (__in_atomic_pool(cpu_addr, PAGE_SIZE))
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return __atomic_get_pages(cpu_addr);
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if (attrs & DMA_ATTR_NO_KERNEL_MAPPING)
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return cpu_addr;
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area = find_vm_area(cpu_addr);
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if (area && (area->flags & VM_DMA_COHERENT))
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return area->pages;
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return NULL;
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return dma_common_find_pages(cpu_addr);
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}
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static void *__iommu_alloc_simple(struct device *dev, size_t size, gfp_t gfp,
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@ -541,15 +541,6 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev,
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return pages;
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}
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static struct page **__iommu_dma_get_pages(void *cpu_addr)
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{
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struct vm_struct *area = find_vm_area(cpu_addr);
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if (!area || !area->pages)
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return NULL;
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return area->pages;
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}
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/**
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* iommu_dma_alloc_remap - Allocate and map a buffer contiguous in IOVA space
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* @dev: Device to allocate memory for. Must be a real device
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@ -938,7 +929,7 @@ static void __iommu_dma_free(struct device *dev, size_t size, void *cpu_addr)
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* If it the address is remapped, then it's either non-coherent
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* or highmem CMA, or an iommu_dma_alloc_remap() construction.
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*/
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pages = __iommu_dma_get_pages(cpu_addr);
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pages = dma_common_find_pages(cpu_addr);
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if (!pages)
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page = vmalloc_to_page(cpu_addr);
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dma_common_free_remap(cpu_addr, alloc_size);
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@ -1045,7 +1036,7 @@ static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma,
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return -ENXIO;
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if (IS_ENABLED(CONFIG_DMA_REMAP) && is_vmalloc_addr(cpu_addr)) {
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struct page **pages = __iommu_dma_get_pages(cpu_addr);
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struct page **pages = dma_common_find_pages(cpu_addr);
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if (pages)
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return __iommu_dma_mmap(pages, size, vma);
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@ -1067,7 +1058,7 @@ static int iommu_dma_get_sgtable(struct device *dev, struct sg_table *sgt,
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int ret;
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if (IS_ENABLED(CONFIG_DMA_REMAP) && is_vmalloc_addr(cpu_addr)) {
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struct page **pages = __iommu_dma_get_pages(cpu_addr);
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struct page **pages = dma_common_find_pages(cpu_addr);
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if (pages) {
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return sg_alloc_table_from_pages(sgt, pages,
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@ -626,6 +626,7 @@ extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
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void *cpu_addr, dma_addr_t dma_addr, size_t size,
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unsigned long attrs);
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struct page **dma_common_find_pages(void *cpu_addr);
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void *dma_common_contiguous_remap(struct page *page, size_t size,
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pgprot_t prot, const void *caller);
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@ -11,6 +11,15 @@
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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struct page **dma_common_find_pages(void *cpu_addr)
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{
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struct vm_struct *area = find_vm_area(cpu_addr);
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if (!area || area->flags != VM_DMA_COHERENT)
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return NULL;
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return area->pages;
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}
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static struct vm_struct *__dma_common_pages_remap(struct page **pages,
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size_t size, pgprot_t prot, const void *caller)
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{
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@ -78,9 +87,9 @@ void *dma_common_contiguous_remap(struct page *page, size_t size,
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*/
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void dma_common_free_remap(void *cpu_addr, size_t size)
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{
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struct vm_struct *area = find_vm_area(cpu_addr);
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struct page **pages = dma_common_find_pages(cpu_addr);
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if (!area || area->flags != VM_DMA_COHERENT) {
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if (!pages) {
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WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
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return;
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}
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