From 1424532b2163bf1580f4b1091a5801e12310fac5 Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Wed, 29 Apr 2015 11:29:19 +0100 Subject: ARM: 8347/1: dma-mapping: fix off-by-one check in arm_setup_iommu_dma_ops Patch 22b3c181c6c324a46f71aae806d8ddbe61d25761 ("arm: dma-mapping: limit IOMMU mapping size") added a check for IO address space size. However this patch broke IOMMU initialization for typical platforms initialized from device tree, which get the default IO address space size of 4GiB. This value doesn't fit into size_t and fails a check introduced by that commit resulting in failed dma-mapping/iommu initialization. This patch fixes this issue by adding proper support for full 4GiB address space size. Signed-off-by: Marek Szyprowski Acked-by: Will Deacon Signed-off-by: Russell King --- arch/arm/mm/dma-mapping.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) (limited to 'arch/arm/mm/dma-mapping.c') diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 09c5fe3d30c2..7e7583ddd607 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1878,7 +1878,7 @@ struct dma_map_ops iommu_coherent_ops = { * arm_iommu_attach_device function. */ struct dma_iommu_mapping * -arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size) +arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, u64 size) { unsigned int bits = size >> PAGE_SHIFT; unsigned int bitmap_size = BITS_TO_LONGS(bits) * sizeof(long); @@ -1886,6 +1886,10 @@ arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size) int extensions = 1; int err = -ENOMEM; + /* currently only 32-bit DMA address space is supported */ + if (size > DMA_BIT_MASK(32) + 1) + return ERR_PTR(-ERANGE); + if (!bitmap_size) return ERR_PTR(-EINVAL); @@ -2057,13 +2061,6 @@ static bool arm_setup_iommu_dma_ops(struct device *dev, u64 dma_base, u64 size, if (!iommu) return false; - /* - * currently arm_iommu_create_mapping() takes a max of size_t - * for size param. So check this limit for now. - */ - if (size > SIZE_MAX) - return false; - mapping = arm_iommu_create_mapping(dev->bus, dma_base, size); if (IS_ERR(mapping)) { pr_warn("Failed to create %llu-byte IOMMU mapping for device %s\n", -- cgit v1.2.3 From 55af8a91640d362b20f2491336fce128c48f4079 Mon Sep 17 00:00:00 2001 From: Mike Looijmans Date: Wed, 3 Jun 2015 11:25:31 +0100 Subject: ARM: 8387/1: arm/mm/dma-mapping.c: Add arm_coherent_dma_mmap When dma-coherent transfers are enabled, the mmap call must not change the pg_prot flags in the vma struct. Split the arm_dma_mmap into a common and specific parts, and add a "arm_coherent_dma_mmap" implementation that does not alter the page protection flags. Tested on a topic-miami board (Zynq) using the ACP port to transfer data between FPGA and CPU using the Dyplo framework. Without this patch, byte-wise access to mmapped coherent DMA memory was about 20x slower because of the memory being marked as non-cacheable, and transfer speeds would not exceed 240MB/s. After this patch, the mapped memory is cacheable and the transfer speed is again 600MB/s (limited by the FPGA) when the data is in the L2 cache, while data integrity is being maintained. The patch has no effect on non-coherent DMA. Signed-off-by: Mike Looijmans Acked-by: Arnd Bergmann Signed-off-by: Russell King --- arch/arm/mm/dma-mapping.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) (limited to 'arch/arm/mm/dma-mapping.c') diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 09c5fe3d30c2..d6f5256acc0d 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -148,11 +148,14 @@ static void *arm_coherent_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs); static void arm_coherent_dma_free(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle, struct dma_attrs *attrs); +static int arm_coherent_dma_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + struct dma_attrs *attrs); struct dma_map_ops arm_coherent_dma_ops = { .alloc = arm_coherent_dma_alloc, .free = arm_coherent_dma_free, - .mmap = arm_dma_mmap, + .mmap = arm_coherent_dma_mmap, .get_sgtable = arm_dma_get_sgtable, .map_page = arm_coherent_dma_map_page, .map_sg = arm_dma_map_sg, @@ -690,10 +693,7 @@ static void *arm_coherent_dma_alloc(struct device *dev, size_t size, attrs, __builtin_return_address(0)); } -/* - * Create userspace mapping for the DMA-coherent memory. - */ -int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, +static int __arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs) { @@ -704,8 +704,6 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, unsigned long pfn = dma_to_pfn(dev, dma_addr); unsigned long off = vma->vm_pgoff; - vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); - if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) return ret; @@ -720,6 +718,26 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, return ret; } +/* + * Create userspace mapping for the DMA-coherent memory. + */ +static int arm_coherent_dma_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 __arm_dma_mmap(dev, vma, cpu_addr, dma_addr, size, attrs); +} + +int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + struct dma_attrs *attrs) +{ +#ifdef CONFIG_MMU + vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot); +#endif /* CONFIG_MMU */ + return __arm_dma_mmap(dev, vma, cpu_addr, dma_addr, size, attrs); +} + /* * Free a buffer as defined by the above mapping. */ -- cgit v1.2.3