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authorLinus Torvalds <torvalds@linux-foundation.org>2017-03-07 10:23:17 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-03-07 10:23:17 -0800
commit8c2c8ed8b85d4012d26caf1c221c291c687d89f0 (patch)
treec28ac6bfc83c198b2a61515694d05ad22f2cc25a /drivers/xen
parent304362a8bce1a5b7f9491be5a0643cd14a52364d (diff)
parent69369f52d28a34c84acb6f2a8a585e743441566a (diff)
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Merge branch 'stable/for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb
Pull swiotlb updates from Konrad Rzeszutek Wilk: "Two tiny implementations of the DMA API for callback in ARM (for Xen)" * 'stable/for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: swiotlb-xen: implement xen_swiotlb_get_sgtable callback swiotlb-xen: implement xen_swiotlb_dma_mmap callback
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/swiotlb-xen.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index f8afc6dcc29f..e8cef1ad0fe3 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -681,3 +681,50 @@ xen_swiotlb_set_dma_mask(struct device *dev, u64 dma_mask)
return 0;
}
EXPORT_SYMBOL_GPL(xen_swiotlb_set_dma_mask);
+
+/*
+ * Create userspace mapping for the DMA-coherent memory.
+ * This function should be called with the pages from the current domain only,
+ * passing pages mapped from other domains would lead to memory corruption.
+ */
+int
+xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ unsigned long attrs)
+{
+#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
+ if (__generic_dma_ops(dev)->mmap)
+ return __generic_dma_ops(dev)->mmap(dev, vma, cpu_addr,
+ dma_addr, size, attrs);
+#endif
+ return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
+}
+EXPORT_SYMBOL_GPL(xen_swiotlb_dma_mmap);
+
+/*
+ * This function should be called with the pages from the current domain only,
+ * passing pages mapped from other domains would lead to memory corruption.
+ */
+int
+xen_swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
+ void *cpu_addr, dma_addr_t handle, size_t size,
+ unsigned long attrs)
+{
+#if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
+ if (__generic_dma_ops(dev)->get_sgtable) {
+#if 0
+ /*
+ * This check verifies that the page belongs to the current domain and
+ * is not one mapped from another domain.
+ * This check is for debug only, and should not go to production build
+ */
+ unsigned long bfn = PHYS_PFN(dma_to_phys(dev, handle));
+ BUG_ON (!page_is_ram(bfn));
+#endif
+ return __generic_dma_ops(dev)->get_sgtable(dev, sgt, cpu_addr,
+ handle, size, attrs);
+ }
+#endif
+ return dma_common_get_sgtable(dev, sgt, cpu_addr, handle, size);
+}
+EXPORT_SYMBOL_GPL(xen_swiotlb_get_sgtable);
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