swiotlb-xen: implement xen_swiotlb_get_sgtable callback

Signed-off-by: Andrii Anisov <andrii_anisov@epam.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>

diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index cd1684e..76ea48a 100644 (file)
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -199,6 +199,7 @@ static struct dma_map_ops xen_swiotlb_dma_ops = {
        .dma_supported = xen_swiotlb_dma_supported,
        .set_dma_mask = xen_swiotlb_set_dma_mask,
        .mmap = xen_swiotlb_dma_mmap,
+       .get_sgtable = xen_swiotlb_get_sgtable,
 };
 
 int __init xen_mm_init(void)

diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index c7f61fc..23e30b4 100644 (file)
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -699,3 +699,31 @@ xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma,
        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);

diff --git a/include/xen/swiotlb-xen.h b/include/xen/swiotlb-xen.h
index a315c87..1f6d78f 100644 (file)
--- a/include/xen/swiotlb-xen.h
+++ b/include/xen/swiotlb-xen.h
@@ -2,6 +2,7 @@
 #define __LINUX_SWIOTLB_XEN_H
 
 #include <linux/dma-direction.h>
+#include <linux/scatterlist.h>
 #include <linux/swiotlb.h>
 
 extern int xen_swiotlb_init(int verbose, bool early);
@@ -60,4 +61,9 @@ extern 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);
+
+extern 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);
 #endif /* __LINUX_SWIOTLB_XEN_H */