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authorChristoph Hellwig <hch@lst.de>2019-01-16 19:01:48 +0100
committerChristoph Hellwig <hch@lst.de>2019-01-23 22:14:56 +0100
commit60d8cd572f655aac6107a2330dced004ad1fe3d7 (patch)
treeca68772a843082cf5dfa42cad2f9275cc53e4984 /arch/arm
parent333478a7eb21245880c89aad166ad08478cc577d (diff)
downloadlinux-60d8cd572f655aac6107a2330dced004ad1fe3d7.tar.bz2
arm64/xen: fix xen-swiotlb cache flushing
Xen-swiotlb hooks into the arm/arm64 arch code through a copy of the DMA DMA mapping operations stored in the struct device arch data. Switching arm64 to use the direct calls for the merged DMA direct / swiotlb code broke this scheme. Replace the indirect calls with direct-calls in xen-swiotlb as well to fix this problem. Fixes: 356da6d0cde3 ("dma-mapping: bypass indirect calls for dma-direct") Reported-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/xen/page-coherent.h94
1 files changed, 94 insertions, 0 deletions
diff --git a/arch/arm/include/asm/xen/page-coherent.h b/arch/arm/include/asm/xen/page-coherent.h
index b3ef061d8b74..2c403e7c782d 100644
--- a/arch/arm/include/asm/xen/page-coherent.h
+++ b/arch/arm/include/asm/xen/page-coherent.h
@@ -1 +1,95 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
+#define _ASM_ARM_XEN_PAGE_COHERENT_H
+
+#include <linux/dma-mapping.h>
+#include <asm/page.h>
#include <xen/arm/page-coherent.h>
+
+static inline const struct dma_map_ops *xen_get_dma_ops(struct device *dev)
+{
+ if (dev && dev->archdata.dev_dma_ops)
+ return dev->archdata.dev_dma_ops;
+ return get_arch_dma_ops(NULL);
+}
+
+static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
+ dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
+{
+ return xen_get_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
+}
+
+static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
+ void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
+{
+ xen_get_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
+}
+
+static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
+ dma_addr_t dev_addr, unsigned long offset, size_t size,
+ enum dma_data_direction dir, unsigned long attrs)
+{
+ unsigned long page_pfn = page_to_xen_pfn(page);
+ unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
+ unsigned long compound_pages =
+ (1<<compound_order(page)) * XEN_PFN_PER_PAGE;
+ bool local = (page_pfn <= dev_pfn) &&
+ (dev_pfn - page_pfn < compound_pages);
+
+ /*
+ * Dom0 is mapped 1:1, while the Linux page can span across
+ * multiple Xen pages, it's not possible for it to contain a
+ * mix of local and foreign Xen pages. So if the first xen_pfn
+ * == mfn the page is local otherwise it's a foreign page
+ * grant-mapped in dom0. If the page is local we can safely
+ * call the native dma_ops function, otherwise we call the xen
+ * specific function.
+ */
+ if (local)
+ xen_get_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
+ else
+ __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
+}
+
+static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
+ size_t size, enum dma_data_direction dir, unsigned long attrs)
+{
+ unsigned long pfn = PFN_DOWN(handle);
+ /*
+ * Dom0 is mapped 1:1, while the Linux page can be spanned accross
+ * multiple Xen page, it's not possible to have a mix of local and
+ * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
+ * foreign mfn will always return false. If the page is local we can
+ * safely call the native dma_ops function, otherwise we call the xen
+ * specific function.
+ */
+ if (pfn_valid(pfn)) {
+ if (xen_get_dma_ops(hwdev)->unmap_page)
+ xen_get_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
+ } else
+ __xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
+}
+
+static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
+ dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+ unsigned long pfn = PFN_DOWN(handle);
+ if (pfn_valid(pfn)) {
+ if (xen_get_dma_ops(hwdev)->sync_single_for_cpu)
+ xen_get_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
+ } else
+ __xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
+}
+
+static inline void xen_dma_sync_single_for_device(struct device *hwdev,
+ dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+ unsigned long pfn = PFN_DOWN(handle);
+ if (pfn_valid(pfn)) {
+ if (xen_get_dma_ops(hwdev)->sync_single_for_device)
+ xen_get_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
+ } else
+ __xen_dma_sync_single_for_device(hwdev, handle, size, dir);
+}
+
+#endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */