From: Mitchel Humpherys <mitchelh@codeaurora.org>
Date: Fri, 27 May 2016 21:58:31 +0000 (-0700)
Subject: arm64: dma-mapping: Attach IOMMUs as groups
X-Git-Url: http://git.osdn.net/view?a=commitdiff_plain;h=6a70911936b5;p=sagit-ice-cold%2Fkernel_xiaomi_msm8998.git

arm64: dma-mapping: Attach IOMMUs as groups

Some devices behind IOMMUs might end up in IOMMU groups due to DMA
aliasing.  The iommu_attach_device API expects a single device in a
group all by its lonesome, so it fails when a device is passed in that's
part of a group.  Use iommu_attach_group to accommodate these types of
devices.

CRs-Fixed: 1023180
Change-Id: I9601efd300c7f428c4576e6ecf6d31791d0b47bd
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>
---

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index c2819df04b3f..6b151d483f5c 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -2114,12 +2114,19 @@ int arm_iommu_attach_device(struct device *dev,
 {
 	int err;
 	int s1_bypass = 0, is_fast = 0;
+	struct iommu_group *group;
 
 	iommu_domain_get_attr(mapping->domain, DOMAIN_ATTR_FAST, &is_fast);
 	if (is_fast)
 		return fast_smmu_attach_device(dev, mapping);
 
-	err = iommu_attach_device(mapping->domain, dev);
+	group = iommu_group_get(dev);
+	if (!group) {
+		dev_err(dev, "Couldn't get group\n");
+		return -ENODEV;
+	}
+
+	err = iommu_attach_group(mapping->domain, group);
 	if (err)
 		return err;
 
@@ -2147,6 +2154,7 @@ void arm_iommu_detach_device(struct device *dev)
 {
 	struct dma_iommu_mapping *mapping;
 	int is_fast;
+	struct iommu_group *group;
 
 	mapping = to_dma_iommu_mapping(dev);
 	if (!mapping) {
@@ -2160,7 +2168,13 @@ void arm_iommu_detach_device(struct device *dev)
 		return;
 	}
 
-	iommu_detach_device(mapping->domain, dev);
+	group = iommu_group_get(dev);
+	if (!group) {
+		dev_err(dev, "Couldn't get group\n");
+		return;
+	}
+
+	iommu_detach_group(mapping->domain, group);
 	kref_put(&mapping->kref, release_iommu_mapping);
 	dev->archdata.mapping = NULL;
 	set_dma_ops(dev, NULL);