Implement the alloc_noncoherent method to provide memory that is neither coherent not contiguous.
Signed-off-by: Christoph Hellwig hch@lst.de --- drivers/iommu/dma-iommu.c | 41 +++++++++++++++++++++++++++++++++++---- 1 file changed, 37 insertions(+), 4 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 00a5b49248e334..c12c1dc43d312e 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -572,6 +572,7 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev, * @size: Size of buffer in bytes * @dma_handle: Out argument for allocated DMA handle * @gfp: Allocation flags + * @prot: pgprot_t to use for the remapped mapping * @attrs: DMA attributes for this allocation * * If @size is less than PAGE_SIZE, then a full CPU page will be allocated, @@ -580,14 +581,14 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev, * Return: Mapped virtual address, or NULL on failure. */ static void *iommu_dma_alloc_remap(struct device *dev, size_t size, - dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs) + dma_addr_t *dma_handle, gfp_t gfp, pgprot_t prot, + unsigned long attrs) { struct iommu_domain *domain = iommu_get_dma_domain(dev); struct iommu_dma_cookie *cookie = domain->iova_cookie; struct iova_domain *iovad = &cookie->iovad; bool coherent = dev_is_dma_coherent(dev); int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs); - pgprot_t prot = dma_pgprot(dev, PAGE_KERNEL, attrs); unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap; struct page **pages; struct sg_table sgt; @@ -1030,8 +1031,10 @@ static void *iommu_dma_alloc(struct device *dev, size_t size, gfp |= __GFP_ZERO;
if (IS_ENABLED(CONFIG_DMA_REMAP) && gfpflags_allow_blocking(gfp) && - !(attrs & DMA_ATTR_FORCE_CONTIGUOUS)) - return iommu_dma_alloc_remap(dev, size, handle, gfp, attrs); + !(attrs & DMA_ATTR_FORCE_CONTIGUOUS)) { + return iommu_dma_alloc_remap(dev, size, handle, gfp, + dma_pgprot(dev, PAGE_KERNEL, attrs), attrs); + }
if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) && !gfpflags_allow_blocking(gfp) && !coherent) @@ -1052,6 +1055,34 @@ static void *iommu_dma_alloc(struct device *dev, size_t size, return cpu_addr; }
+#ifdef CONFIG_DMA_REMAP +static void *iommu_dma_alloc_noncoherent(struct device *dev, size_t size, + dma_addr_t *handle, enum dma_data_direction dir, gfp_t gfp) +{ + if (!gfpflags_allow_blocking(gfp)) { + struct page *page; + + page = dma_common_alloc_pages(dev, size, handle, dir, gfp); + if (!page) + return NULL; + return page_address(page); + } + + return iommu_dma_alloc_remap(dev, size, handle, gfp | __GFP_ZERO, + PAGE_KERNEL, 0); +} + +static void iommu_dma_free_noncoherent(struct device *dev, size_t size, + void *cpu_addr, dma_addr_t handle, enum dma_data_direction dir) +{ + __iommu_dma_unmap(dev, handle, size); + __iommu_dma_free(dev, size, cpu_addr); +} +#else +#define iommu_dma_alloc_noncoherent NULL +#define iommu_dma_free_noncoherent NULL +#endif /* CONFIG_DMA_REMAP */ + static int iommu_dma_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, unsigned long attrs) @@ -1122,6 +1153,8 @@ static const struct dma_map_ops iommu_dma_ops = { .free = iommu_dma_free, .alloc_pages = dma_common_alloc_pages, .free_pages = dma_common_free_pages, + .alloc_noncoherent = iommu_dma_alloc_noncoherent, + .free_noncoherent = iommu_dma_free_noncoherent, .mmap = iommu_dma_mmap, .get_sgtable = iommu_dma_get_sgtable, .map_page = iommu_dma_map_page,