From e0d072782c734d27f5af062c62266f2598f68542 Mon Sep 17 00:00:00 2001 From: Jim Quinlan Date: Thu, 17 Sep 2020 18:43:40 +0200 Subject: dma-mapping: introduce DMA range map, supplanting dma_pfn_offset The new field 'dma_range_map' in struct device is used to facilitate the use of single or multiple offsets between mapping regions of cpu addrs and dma addrs. It subsumes the role of "dev->dma_pfn_offset" which was only capable of holding a single uniform offset and had no region bounds checking. The function of_dma_get_range() has been modified so that it takes a single argument -- the device node -- and returns a map, NULL, or an error code. The map is an array that holds the information regarding the DMA regions. Each range entry contains the address offset, the cpu_start address, the dma_start address, and the size of the region. of_dma_configure() is the typical manner to set range offsets but there are a number of ad hoc assignments to "dev->dma_pfn_offset" in the kernel driver code. These cases now invoke the function dma_direct_set_offset(dev, cpu_addr, dma_addr, size). Signed-off-by: Jim Quinlan [hch: various interface cleanups] Signed-off-by: Christoph Hellwig Reviewed-by: Mathieu Poirier Tested-by: Mathieu Poirier Tested-by: Nathan Chancellor --- drivers/iommu/io-pgtable-arm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/iommu/io-pgtable-arm.c') diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index dc7bcf858b6d..d77e881516a4 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -751,7 +751,7 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg) if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS) return NULL; - if (!selftest_running && cfg->iommu_dev->dma_pfn_offset) { + if (!selftest_running && cfg->iommu_dev->dma_range_map) { dev_err(cfg->iommu_dev, "Cannot accommodate DMA offset for IOMMU page tables\n"); return NULL; } -- cgit v1.2.3 From b9bb694b9f62f4b31652223ed3ca38cf98bbb370 Mon Sep 17 00:00:00 2001 From: Robin Murphy Date: Mon, 21 Sep 2020 16:08:01 +0100 Subject: iommu/io-pgtable-arm: Clean up faulty sanity check Checking for a nonzero dma_pfn_offset was a quick shortcut to validate whether the DMA == phys assumption could hold at all. Checking for a non-NULL dma_range_map is not quite equivalent, since a map may be present to describe a limited DMA window even without an offset, and thus this check can now yield false positives. However, it only ever served to short-circuit going all the way through to __arm_lpae_alloc_pages(), failing the canonical test there, and having a bit more to clean up. As such, we can simply remove it without loss of correctness. Reported-by: Naresh Kamboju Signed-off-by: Robin Murphy Signed-off-by: Christoph Hellwig --- drivers/iommu/io-pgtable-arm.c | 5 ----- 1 file changed, 5 deletions(-) (limited to 'drivers/iommu/io-pgtable-arm.c') diff --git a/drivers/iommu/io-pgtable-arm.c b/drivers/iommu/io-pgtable-arm.c index d77e881516a4..f87cbb822a3d 100644 --- a/drivers/iommu/io-pgtable-arm.c +++ b/drivers/iommu/io-pgtable-arm.c @@ -751,11 +751,6 @@ arm_lpae_alloc_pgtable(struct io_pgtable_cfg *cfg) if (cfg->oas > ARM_LPAE_MAX_ADDR_BITS) return NULL; - if (!selftest_running && cfg->iommu_dev->dma_range_map) { - dev_err(cfg->iommu_dev, "Cannot accommodate DMA offset for IOMMU page tables\n"); - return NULL; - } - data = kmalloc(sizeof(*data), GFP_KERNEL); if (!data) return NULL; -- cgit v1.2.3