From 8617a5c5bc001e52c40d6b2ece78e8f332039217 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 13 Feb 2019 08:01:05 +0100 Subject: [PATCH] powerpc/dma: handle iommu bypass in dma_iommu_ops Add a new iommu_bypass flag to struct dev_archdata so that the dma_iommu implementation can handle the direct mapping transparently instead of switiching ops around. Setting of this flag is controlled by new pci_controller_ops method. Signed-off-by: Christoph Hellwig Tested-by: Christian Zigotzky Signed-off-by: Michael Ellerman --- arch/powerpc/include/asm/device.h | 5 ++ arch/powerpc/include/asm/dma-mapping.h | 8 +++ arch/powerpc/include/asm/pci-bridge.h | 2 + arch/powerpc/kernel/dma-iommu.c | 70 +++++++++++++++++++++++--- arch/powerpc/kernel/dma.c | 19 +++---- 5 files changed, 87 insertions(+), 17 deletions(-) diff --git a/arch/powerpc/include/asm/device.h b/arch/powerpc/include/asm/device.h index 0245bfcaac32..1aa53318b4bc 100644 --- a/arch/powerpc/include/asm/device.h +++ b/arch/powerpc/include/asm/device.h @@ -19,6 +19,11 @@ struct iommu_table; * drivers/macintosh/macio_asic.c */ struct dev_archdata { + /* + * Set to %true if the dma_iommu_ops are requested to use a direct + * window instead of dynamically mapping memory. + */ + bool iommu_bypass : 1; /* * These two used to be a union. However, with the hybrid ops we need * both so here we store both a DMA offset for direct mappings and diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h index ebf66809f2d3..ff86b863eceb 100644 --- a/arch/powerpc/include/asm/dma-mapping.h +++ b/arch/powerpc/include/asm/dma-mapping.h @@ -29,6 +29,14 @@ extern int dma_nommu_mmap_coherent(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t handle, size_t size, unsigned long attrs); +int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl, + int nents, enum dma_data_direction direction, + unsigned long attrs); +dma_addr_t dma_nommu_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, unsigned long attrs); +int dma_nommu_dma_supported(struct device *dev, u64 mask); +u64 dma_nommu_get_required_mask(struct device *dev); #ifdef CONFIG_NOT_COHERENT_CACHE /* diff --git a/arch/powerpc/include/asm/pci-bridge.h b/arch/powerpc/include/asm/pci-bridge.h index aee4fcc24990..d7492dca6599 100644 --- a/arch/powerpc/include/asm/pci-bridge.h +++ b/arch/powerpc/include/asm/pci-bridge.h @@ -19,6 +19,8 @@ struct device_node; struct pci_controller_ops { void (*dma_dev_setup)(struct pci_dev *pdev); void (*dma_bus_setup)(struct pci_bus *bus); + bool (*iommu_bypass_supported)(struct pci_dev *pdev, + u64 mask); int (*probe_mode)(struct pci_bus *bus); diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c index dd8601cd20df..fda92156b194 100644 --- a/arch/powerpc/kernel/dma-iommu.c +++ b/arch/powerpc/kernel/dma-iommu.c @@ -6,12 +6,30 @@ * busses using the iommu infrastructure */ +#include +#include #include /* * Generic iommu implementation */ +/* + * The coherent mask may be smaller than the real mask, check if we can + * really use a direct window. + */ +static inline bool dma_iommu_alloc_bypass(struct device *dev) +{ + return dev->archdata.iommu_bypass && + dma_nommu_dma_supported(dev, dev->coherent_dma_mask); +} + +static inline bool dma_iommu_map_bypass(struct device *dev, + unsigned long attrs) +{ + return dev->archdata.iommu_bypass; +} + /* Allocates a contiguous real buffer and creates mappings over it. * Returns the virtual address of the buffer and sets dma_handle * to the dma address (mapping) of the first page. @@ -20,6 +38,9 @@ static void *dma_iommu_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag, unsigned long attrs) { + if (dma_iommu_alloc_bypass(dev)) + return __dma_nommu_alloc_coherent(dev, size, dma_handle, flag, + attrs); return iommu_alloc_coherent(dev, get_iommu_table_base(dev), size, dma_handle, dev->coherent_dma_mask, flag, dev_to_node(dev)); @@ -29,7 +50,11 @@ static void dma_iommu_free_coherent(struct device *dev, size_t size, void *vaddr, dma_addr_t dma_handle, unsigned long attrs) { - iommu_free_coherent(get_iommu_table_base(dev), size, vaddr, dma_handle); + if (dma_iommu_alloc_bypass(dev)) + __dma_nommu_free_coherent(dev, size, vaddr, dma_handle, attrs); + else + iommu_free_coherent(get_iommu_table_base(dev), size, vaddr, + dma_handle); } /* Creates TCEs for a user provided buffer. The user buffer must be @@ -42,6 +67,9 @@ static dma_addr_t dma_iommu_map_page(struct device *dev, struct page *page, enum dma_data_direction direction, unsigned long attrs) { + if (dma_iommu_map_bypass(dev, attrs)) + return dma_nommu_map_page(dev, page, offset, size, direction, + attrs); return iommu_map_page(dev, get_iommu_table_base(dev), page, offset, size, device_to_mask(dev), direction, attrs); } @@ -51,8 +79,9 @@ static void dma_iommu_unmap_page(struct device *dev, dma_addr_t dma_handle, size_t size, enum dma_data_direction direction, unsigned long attrs) { - iommu_unmap_page(get_iommu_table_base(dev), dma_handle, size, direction, - attrs); + if (!dma_iommu_map_bypass(dev, attrs)) + iommu_unmap_page(get_iommu_table_base(dev), dma_handle, size, + direction, attrs); } @@ -60,6 +89,8 @@ static int dma_iommu_map_sg(struct device *dev, struct scatterlist *sglist, int nelems, enum dma_data_direction direction, unsigned long attrs) { + if (dma_iommu_map_bypass(dev, attrs)) + return dma_nommu_map_sg(dev, sglist, nelems, direction, attrs); return ppc_iommu_map_sg(dev, get_iommu_table_base(dev), sglist, nelems, device_to_mask(dev), direction, attrs); } @@ -68,10 +99,20 @@ static void dma_iommu_unmap_sg(struct device *dev, struct scatterlist *sglist, int nelems, enum dma_data_direction direction, unsigned long attrs) { - ppc_iommu_unmap_sg(get_iommu_table_base(dev), sglist, nelems, + if (!dma_iommu_map_bypass(dev, attrs)) + ppc_iommu_unmap_sg(get_iommu_table_base(dev), sglist, nelems, direction, attrs); } +static bool dma_iommu_bypass_supported(struct device *dev, u64 mask) +{ + struct pci_dev *pdev = to_pci_dev(dev); + struct pci_controller *phb = pci_bus_to_host(pdev->bus); + + return phb->controller_ops.iommu_bypass_supported && + phb->controller_ops.iommu_bypass_supported(pdev, mask); +} + /* We support DMA to/from any memory page via the iommu */ int dma_iommu_dma_supported(struct device *dev, u64 mask) { @@ -83,22 +124,39 @@ int dma_iommu_dma_supported(struct device *dev, u64 mask) return 0; } + if (dev_is_pci(dev) && dma_iommu_bypass_supported(dev, mask)) { + dev->archdata.iommu_bypass = true; + dev_dbg(dev, "iommu: 64-bit OK, using fixed ops\n"); + return 1; + } + if (tbl->it_offset > (mask >> tbl->it_page_shift)) { dev_info(dev, "Warning: IOMMU offset too big for device mask\n"); dev_info(dev, "mask: 0x%08llx, table offset: 0x%08lx\n", mask, tbl->it_offset << tbl->it_page_shift); return 0; - } else - return 1; + } + + dev_dbg(dev, "iommu: not 64-bit, using default ops\n"); + dev->archdata.iommu_bypass = false; + return 1; } u64 dma_iommu_get_required_mask(struct device *dev) { struct iommu_table *tbl = get_iommu_table_base(dev); u64 mask; + if (!tbl) return 0; + if (dev_is_pci(dev)) { + u64 bypass_mask = dma_nommu_get_required_mask(dev); + + if (dma_iommu_bypass_supported(dev, bypass_mask)) + return bypass_mask; + } + mask = 1ULL < (fls_long(tbl->it_offset + tbl->it_size) - 1); mask += mask - 1; diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c index b1903ebb2e9c..e5db4d3f8bea 100644 --- a/arch/powerpc/kernel/dma.c +++ b/arch/powerpc/kernel/dma.c @@ -40,7 +40,7 @@ static u64 __maybe_unused get_pfn_limit(struct device *dev) return pfn; } -static int dma_nommu_dma_supported(struct device *dev, u64 mask) +int dma_nommu_dma_supported(struct device *dev, u64 mask) { #ifdef CONFIG_PPC64 u64 limit = get_dma_offset(dev) + (memblock_end_of_DRAM() - 1); @@ -178,9 +178,9 @@ int dma_nommu_mmap_coherent(struct device *dev, struct vm_area_struct *vma, vma->vm_page_prot); } -static int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl, - int nents, enum dma_data_direction direction, - unsigned long attrs) +int dma_nommu_map_sg(struct device *dev, struct scatterlist *sgl, + int nents, enum dma_data_direction direction, + unsigned long attrs) { struct scatterlist *sg; int i; @@ -209,7 +209,7 @@ static void dma_nommu_unmap_sg(struct device *dev, struct scatterlist *sgl, __dma_sync_page(sg_page(sg), sg->offset, sg->length, direction); } -static u64 dma_nommu_get_required_mask(struct device *dev) +u64 dma_nommu_get_required_mask(struct device *dev) { u64 end, mask; @@ -221,12 +221,9 @@ static u64 dma_nommu_get_required_mask(struct device *dev) return mask; } -static inline dma_addr_t dma_nommu_map_page(struct device *dev, - struct page *page, - unsigned long offset, - size_t size, - enum dma_data_direction dir, - unsigned long attrs) +dma_addr_t dma_nommu_map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, unsigned long attrs) { if (!(attrs & DMA_ATTR_SKIP_CPU_SYNC)) __dma_sync_page(page, offset, size, dir); -- 2.30.2