From 69908907b02efee31377af0cefbcd5a3ba66334a Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 9 Oct 2013 16:56:32 +0000 Subject: xen: make xen_create_contiguous_region return the dma address Modify xen_create_contiguous_region to return the dma address of the newly contiguous buffer. Signed-off-by: Stefano Stabellini Acked-by: Konrad Rzeszutek Wilk Reviewed-by: David Vrabel Changes in v4: - use virt_to_machine instead of virt_to_bus. --- drivers/xen/swiotlb-xen.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'drivers/xen/swiotlb-xen.c') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 1b2277c311d2..b72f31c1e018 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -126,6 +126,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) { int i, rc; int dma_bits; + dma_addr_t dma_handle; dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT; @@ -137,7 +138,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) rc = xen_create_contiguous_region( (unsigned long)buf + (i << IO_TLB_SHIFT), get_order(slabs << IO_TLB_SHIFT), - dma_bits); + dma_bits, &dma_handle); } while (rc && dma_bits++ < max_dma_bits); if (rc) return rc; @@ -294,11 +295,10 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, *dma_handle = dev_addr; else { if (xen_create_contiguous_region(vstart, order, - fls64(dma_mask)) != 0) { + fls64(dma_mask), dma_handle) != 0) { free_pages(vstart, order); return NULL; } - *dma_handle = virt_to_machine(ret).maddr; } memset(ret, 0, size); return ret; -- cgit v1.2.1 From 83862ccfc0a03212fde43b4ac29c28381828768b Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Thu, 10 Oct 2013 13:40:44 +0000 Subject: xen/arm,arm64: enable SWIOTLB_XEN Xen on arm and arm64 needs SWIOTLB_XEN: when running on Xen we need to program the hardware with mfns rather than pfns for dma addresses. Remove SWIOTLB_XEN dependency on X86 and PCI and make XEN select SWIOTLB_XEN on arm and arm64. At the moment always rely on swiotlb-xen, but when Xen starts supporting hardware IOMMUs we'll be able to avoid it conditionally on the presence of an IOMMU on the platform. Implement xen_create_contiguous_region on arm and arm64: for the moment we assume that dom0 has been mapped 1:1 (physical addresses == machine addresses) therefore we don't need to call XENMEM_exchange. Simply return the physical address as dma address. Initialize the xen-swiotlb from xen_early_init (before the native dma_ops are initialized), set xen_dma_ops to &xen_swiotlb_dma_ops. Signed-off-by: Stefano Stabellini Changes in v8: - assume dom0 is mapped 1:1, no need to call XENMEM_exchange. Changes in v7: - call __set_phys_to_machine_multi from xen_create_contiguous_region and xen_destroy_contiguous_region to update the P2M; - don't call XENMEM_unpin, it has been removed; - call XENMEM_exchange instead of XENMEM_exchange_and_pin; - set nr_exchanged to 0 before calling the hypercall. Changes in v6: - introduce and export xen_dma_ops; - call xen_mm_init from as arch_initcall. Changes in v4: - remove redefinition of DMA_ERROR_CODE; - update the code to use XENMEM_exchange_and_pin and XENMEM_unpin; - add a note about hardware IOMMU in the commit message. Changes in v3: - code style changes; - warn on XENMEM_put_dma_buf failures. --- drivers/xen/swiotlb-xen.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/xen/swiotlb-xen.c') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index b72f31c1e018..f0fc1a4f565a 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -42,12 +42,27 @@ #include #include #include +#include /* * Used to do a quick range check in swiotlb_tbl_unmap_single and * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this * API. */ +#ifndef CONFIG_X86 +static unsigned long dma_alloc_coherent_mask(struct device *dev, + gfp_t gfp) +{ + unsigned long dma_mask = 0; + + dma_mask = dev->coherent_dma_mask; + if (!dma_mask) + dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32); + + return dma_mask; +} +#endif + static char *xen_io_tlb_start, *xen_io_tlb_end; static unsigned long xen_io_tlb_nslabs; /* -- cgit v1.2.1 From eb1ddc00b81cb8cb23891b6c7c5fbfaea29f3c73 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Wed, 9 Oct 2013 16:56:33 +0000 Subject: swiotlb-xen: introduce xen_swiotlb_set_dma_mask Implement xen_swiotlb_set_dma_mask, use it for set_dma_mask on arm. Signed-off-by: Stefano Stabellini --- drivers/xen/swiotlb-xen.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'drivers/xen/swiotlb-xen.c') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index f0fc1a4f565a..d8ef0bf577d2 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -608,3 +608,15 @@ xen_swiotlb_dma_supported(struct device *hwdev, u64 mask) return xen_virt_to_bus(xen_io_tlb_end - 1) <= mask; } EXPORT_SYMBOL_GPL(xen_swiotlb_dma_supported); + +int +xen_swiotlb_set_dma_mask(struct device *dev, u64 dma_mask) +{ + if (!dev->dma_mask || !xen_swiotlb_dma_supported(dev, dma_mask)) + return -EIO; + + *dev->dma_mask = dma_mask; + + return 0; +} +EXPORT_SYMBOL_GPL(xen_swiotlb_set_dma_mask); -- cgit v1.2.1 From 1b65c4e5a9af1a1c61e792e2d0ed481e0c1f21a9 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Thu, 10 Oct 2013 13:41:10 +0000 Subject: swiotlb-xen: use xen_alloc/free_coherent_pages Use xen_alloc_coherent_pages and xen_free_coherent_pages to allocate or free coherent pages. We need to be careful handling the pointer returned by xen_alloc_coherent_pages, because on ARM the pointer is not equal to phys_to_virt(*dma_handle). In fact virt_to_phys only works for kernel direct mapped RAM memory. In ARM case the pointer could be an ioremap address, therefore passing it to virt_to_phys would give you another physical address that doesn't correspond to it. Make xen_create_contiguous_region take a phys_addr_t as start parameter to avoid the virt_to_phys calls which would be incorrect. Changes in v6: - remove extra spaces. Signed-off-by: Stefano Stabellini Reviewed-by: Konrad Rzeszutek Wilk --- drivers/xen/swiotlb-xen.c | 31 +++++++++++++++++++++---------- 1 file changed, 21 insertions(+), 10 deletions(-) (limited to 'drivers/xen/swiotlb-xen.c') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index d8ef0bf577d2..189b8db5c983 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -43,6 +43,7 @@ #include #include #include +#include /* * Used to do a quick range check in swiotlb_tbl_unmap_single and * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this @@ -142,6 +143,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) int i, rc; int dma_bits; dma_addr_t dma_handle; + phys_addr_t p = virt_to_phys(buf); dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT; @@ -151,7 +153,7 @@ xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs) do { rc = xen_create_contiguous_region( - (unsigned long)buf + (i << IO_TLB_SHIFT), + p + (i << IO_TLB_SHIFT), get_order(slabs << IO_TLB_SHIFT), dma_bits, &dma_handle); } while (rc && dma_bits++ < max_dma_bits); @@ -279,7 +281,6 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, void *ret; int order = get_order(size); u64 dma_mask = DMA_BIT_MASK(32); - unsigned long vstart; phys_addr_t phys; dma_addr_t dev_addr; @@ -294,8 +295,12 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, if (dma_alloc_from_coherent(hwdev, size, dma_handle, &ret)) return ret; - vstart = __get_free_pages(flags, order); - ret = (void *)vstart; + /* On ARM this function returns an ioremap'ped virtual address for + * which virt_to_phys doesn't return the corresponding physical + * address. In fact on ARM virt_to_phys only works for kernel direct + * mapped RAM memory. Also see comment below. + */ + ret = xen_alloc_coherent_pages(hwdev, size, dma_handle, flags, attrs); if (!ret) return ret; @@ -303,15 +308,19 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, if (hwdev && hwdev->coherent_dma_mask) dma_mask = dma_alloc_coherent_mask(hwdev, flags); - phys = virt_to_phys(ret); + /* At this point dma_handle is the physical address, next we are + * going to set it to the machine address. + * Do not use virt_to_phys(ret) because on ARM it doesn't correspond + * to *dma_handle. */ + phys = *dma_handle; dev_addr = xen_phys_to_bus(phys); if (((dev_addr + size - 1 <= dma_mask)) && !range_straddles_page_boundary(phys, size)) *dma_handle = dev_addr; else { - if (xen_create_contiguous_region(vstart, order, + if (xen_create_contiguous_region(phys, order, fls64(dma_mask), dma_handle) != 0) { - free_pages(vstart, order); + xen_free_coherent_pages(hwdev, size, ret, (dma_addr_t)phys, attrs); return NULL; } } @@ -334,13 +343,15 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr, if (hwdev && hwdev->coherent_dma_mask) dma_mask = hwdev->coherent_dma_mask; - phys = virt_to_phys(vaddr); + /* do not use virt_to_phys because on ARM it doesn't return you the + * physical address */ + phys = xen_bus_to_phys(dev_addr); if (((dev_addr + size - 1 > dma_mask)) || range_straddles_page_boundary(phys, size)) - xen_destroy_contiguous_region((unsigned long)vaddr, order); + xen_destroy_contiguous_region(phys, order); - free_pages((unsigned long)vaddr, order); + xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs); } EXPORT_SYMBOL_GPL(xen_swiotlb_free_coherent); -- cgit v1.2.1 From 6cf054636261ca5c88f3c2984058d51f927b8a2e Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 25 Oct 2013 10:33:25 +0000 Subject: swiotlb-xen: use xen_dma_map/unmap_page, xen_dma_sync_single_for_cpu/device Call xen_dma_map_page, xen_dma_unmap_page, xen_dma_sync_single_for_cpu, xen_dma_sync_single_for_device from swiotlb-xen to ensure cpu/device coherency of the pages used for DMA, including the ones belonging to the swiotlb buffer. Signed-off-by: Stefano Stabellini --- drivers/xen/swiotlb-xen.c | 39 +++++++++++++++++++++++++++++++-------- 1 file changed, 31 insertions(+), 8 deletions(-) (limited to 'drivers/xen/swiotlb-xen.c') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 189b8db5c983..4221cb52387d 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -378,8 +378,13 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, * buffering it. */ if (dma_capable(dev, dev_addr, size) && - !range_straddles_page_boundary(phys, size) && !swiotlb_force) + !range_straddles_page_boundary(phys, size) && !swiotlb_force) { + /* we are not interested in the dma_addr returned by + * xen_dma_map_page, only in the potential cache flushes executed + * by the function. */ + xen_dma_map_page(dev, page, offset, size, dir, attrs); return dev_addr; + } /* * Oh well, have to allocate and map a bounce buffer. @@ -388,6 +393,8 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, if (map == SWIOTLB_MAP_ERROR) return DMA_ERROR_CODE; + xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT), + map & ~PAGE_MASK, size, dir, attrs); dev_addr = xen_phys_to_bus(map); /* @@ -410,12 +417,15 @@ EXPORT_SYMBOL_GPL(xen_swiotlb_map_page); * whatever the device wrote there. */ static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr, - size_t size, enum dma_data_direction dir) + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) { phys_addr_t paddr = xen_bus_to_phys(dev_addr); BUG_ON(dir == DMA_NONE); + xen_dma_unmap_page(hwdev, paddr, size, dir, attrs); + /* NOTE: We use dev_addr here, not paddr! */ if (is_xen_swiotlb_buffer(dev_addr)) { swiotlb_tbl_unmap_single(hwdev, paddr, size, dir); @@ -438,7 +448,7 @@ void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr, size_t size, enum dma_data_direction dir, struct dma_attrs *attrs) { - xen_unmap_single(hwdev, dev_addr, size, dir); + xen_unmap_single(hwdev, dev_addr, size, dir, attrs); } EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_page); @@ -461,11 +471,15 @@ xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr, BUG_ON(dir == DMA_NONE); + if (target == SYNC_FOR_CPU) + xen_dma_sync_single_for_cpu(hwdev, paddr, size, dir); + /* NOTE: We use dev_addr here, not paddr! */ - if (is_xen_swiotlb_buffer(dev_addr)) { + if (is_xen_swiotlb_buffer(dev_addr)) swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target); - return; - } + + if (target == SYNC_FOR_DEVICE) + xen_dma_sync_single_for_cpu(hwdev, paddr, size, dir); if (dir != DMA_FROM_DEVICE) return; @@ -536,8 +550,17 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, return DMA_ERROR_CODE; } sg->dma_address = xen_phys_to_bus(map); - } else + } else { + /* we are not interested in the dma_addr returned by + * xen_dma_map_page, only in the potential cache flushes executed + * by the function. */ + xen_dma_map_page(hwdev, pfn_to_page(paddr >> PAGE_SHIFT), + paddr & ~PAGE_MASK, + sg->length, + dir, + attrs); sg->dma_address = dev_addr; + } sg_dma_len(sg) = sg->length; } return nelems; @@ -559,7 +582,7 @@ xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl, BUG_ON(dir == DMA_NONE); for_each_sg(sgl, sg, nelems, i) - xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir); + xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir, attrs); } EXPORT_SYMBOL_GPL(xen_swiotlb_unmap_sg_attrs); -- cgit v1.2.1 From 783d0281043b9a1111d81d11ed0610b83d8857ed Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 25 Oct 2013 10:33:26 +0000 Subject: swiotlb: print a warning when the swiotlb is full Signed-off-by: Stefano Stabellini Changes in v7: - use dev_warn instead of pr_warn. --- drivers/xen/swiotlb-xen.c | 1 + 1 file changed, 1 insertion(+) (limited to 'drivers/xen/swiotlb-xen.c') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 4221cb52387d..4d50058d9630 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -542,6 +542,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, sg->length, dir); if (map == SWIOTLB_MAP_ERROR) { + dev_warn(hwdev, "swiotlb buffer is full\n"); /* Don't panic here, we expect map_sg users to do proper error handling. */ xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, -- cgit v1.2.1 From 6b42a7eafb25ae9fda1708c501661384d1f60482 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 25 Oct 2013 10:33:27 +0000 Subject: swiotlb-xen: static inline xen_phys_to_bus, xen_bus_to_phys, xen_virt_to_bus and range_straddles_page_boundary This functions are small and called frequently. Static inline them. Signed-off-by: Stefano Stabellini --- drivers/xen/swiotlb-xen.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/xen/swiotlb-xen.c') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 4d50058d9630..100962dcc7bb 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -72,17 +72,17 @@ static unsigned long xen_io_tlb_nslabs; static u64 start_dma_addr; -static dma_addr_t xen_phys_to_bus(phys_addr_t paddr) +static inline dma_addr_t xen_phys_to_bus(phys_addr_t paddr) { return phys_to_machine(XPADDR(paddr)).maddr; } -static phys_addr_t xen_bus_to_phys(dma_addr_t baddr) +static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr) { return machine_to_phys(XMADDR(baddr)).paddr; } -static dma_addr_t xen_virt_to_bus(void *address) +static inline dma_addr_t xen_virt_to_bus(void *address) { return xen_phys_to_bus(virt_to_phys(address)); } @@ -105,7 +105,7 @@ static int check_pages_physically_contiguous(unsigned long pfn, return 1; } -static int range_straddles_page_boundary(phys_addr_t p, size_t size) +static inline int range_straddles_page_boundary(phys_addr_t p, size_t size) { unsigned long pfn = PFN_DOWN(p); unsigned int offset = p & ~PAGE_MASK; -- cgit v1.2.1 From 15177608c703e7b4aa29aa7c93b31001effe504c Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Tue, 29 Oct 2013 00:37:37 +0000 Subject: swiotlb-xen: fix error code returned by xen_swiotlb_map_sg_attrs map_sg returns the number of elements mapped, not a dma_addr_t. In case of error return 0, not DMA_ERROR_CODE. Signed-off-by: Stefano Stabellini --- drivers/xen/swiotlb-xen.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/xen/swiotlb-xen.c') diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 100962dcc7bb..8af68629260b 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -548,7 +548,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir, attrs); sg_dma_len(sgl) = 0; - return DMA_ERROR_CODE; + return 0; } sg->dma_address = xen_phys_to_bus(map); } else { -- cgit v1.2.1