[PATCH v3 09/10] iommu/vt-d: Add dma sync ops for untrusted devices

[Lu Baolu <baolu.lu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

This adds the dma sync ops for dma buffers used by any
untrusted device. We need to sync such buffers because
they might have been mapped with bounce pages.

Cc: Ashok Raj <ashok.raj-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Cc: Jacob Pan <jacob.jun.pan-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Cc: Kevin Tian <kevin.tian-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Lu Baolu <baolu.lu-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
Tested-by: Xu Pengfei <pengfei.xu-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Tested-by: Mika Westerberg <mika.westerberg-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/iommu/Kconfig       |  1 +
 drivers/iommu/intel-iommu.c | 96 +++++++++++++++++++++++++++++++++----
 2 files changed, 88 insertions(+), 9 deletions(-)

diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index b918c22ca25b..f3191ec29e45 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -194,6 +194,7 @@ config INTEL_IOMMU
 	select IOMMU_IOVA
 	select NEED_DMA_MAP_STATE
 	select DMAR_TABLE
+	select IOMMU_BOUNCE_PAGE
 	help
 	  DMA remapping (DMAR) devices support enables independent address
 	  translations for Direct Memory Access (DMA) from devices.
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0d80f26b8a72..ed941ec9b9d5 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3683,16 +3683,94 @@ static int intel_map_sg(struct device *dev, struct scatterlist *sglist, int nele
 	return nelems;
 }
 
+static void
+intel_sync_single_for_cpu(struct device *dev, dma_addr_t addr,
+			  size_t size, enum dma_data_direction dir)
+{
+	if (WARN_ON(dir == DMA_NONE))
+		return;
+
+	if (!device_needs_bounce(dev))
+		return;
+
+	if (iommu_no_mapping(dev))
+		return;
+
+	iommu_bounce_sync_single(dev, addr, size, dir, SYNC_FOR_CPU);
+}
+
+static void
+intel_sync_single_for_device(struct device *dev, dma_addr_t addr,
+			     size_t size, enum dma_data_direction dir)
+{
+	if (WARN_ON(dir == DMA_NONE))
+		return;
+
+	if (!device_needs_bounce(dev))
+		return;
+
+	if (iommu_no_mapping(dev))
+		return;
+
+	iommu_bounce_sync_single(dev, addr, size, dir, SYNC_FOR_DEVICE);
+}
+
+static void
+intel_sync_sg_for_cpu(struct device *dev, struct scatterlist *sglist,
+		      int nelems, enum dma_data_direction dir)
+{
+	struct scatterlist *sg;
+	int i;
+
+	if (WARN_ON(dir == DMA_NONE))
+		return;
+
+	if (!device_needs_bounce(dev))
+		return;
+
+	if (iommu_no_mapping(dev))
+		return;
+
+	for_each_sg(sglist, sg, nelems, i)
+		iommu_bounce_sync_single(dev, sg_dma_address(sg),
+					 sg_dma_len(sg), dir, SYNC_FOR_CPU);
+}
+
+static void
+intel_sync_sg_for_device(struct device *dev, struct scatterlist *sglist,
+			 int nelems, enum dma_data_direction dir)
+{
+	struct scatterlist *sg;
+	int i;
+
+	if (WARN_ON(dir == DMA_NONE))
+		return;
+
+	if (!device_needs_bounce(dev))
+		return;
+
+	if (iommu_no_mapping(dev))
+		return;
+
+	for_each_sg(sglist, sg, nelems, i)
+		iommu_bounce_sync_single(dev, sg_dma_address(sg),
+					 sg_dma_len(sg), dir, SYNC_FOR_DEVICE);
+}
+
 static const struct dma_map_ops intel_dma_ops = {
-	.alloc = intel_alloc_coherent,
-	.free = intel_free_coherent,
-	.map_sg = intel_map_sg,
-	.unmap_sg = intel_unmap_sg,
-	.map_page = intel_map_page,
-	.unmap_page = intel_unmap_page,
-	.map_resource = intel_map_resource,
-	.unmap_resource = intel_unmap_page,
-	.dma_supported = dma_direct_supported,
+	.alloc			= intel_alloc_coherent,
+	.free			= intel_free_coherent,
+	.map_sg			= intel_map_sg,
+	.unmap_sg		= intel_unmap_sg,
+	.map_page		= intel_map_page,
+	.unmap_page		= intel_unmap_page,
+	.sync_single_for_cpu	= intel_sync_single_for_cpu,
+	.sync_single_for_device	= intel_sync_single_for_device,
+	.sync_sg_for_cpu	= intel_sync_sg_for_cpu,
+	.sync_sg_for_device	= intel_sync_sg_for_device,
+	.map_resource		= intel_map_resource,
+	.unmap_resource		= intel_unmap_page,
+	.dma_supported		= dma_direct_supported,
 };
 
 static inline int iommu_domain_cache_init(void)
-- 
2.17.1