iommu/amd: Fix crash when accessing AMD-Vi sysfs entries

The link between the iommu sysfs-device and the struct
amd_iommu is no longer stored as driver-data. Update the
code to the new correct way of getting from device to
amd_iommu.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 39ab9555c241 ('iommu: Add sysfs bindings for struct iommu_device')
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/amd_iommu_init.c

@@ -1507,7 +1507,7 @@ static ssize_t amd_iommu_show_cap(struct device *dev,
 				  struct device_attribute *attr,
 				  char *buf)
 {
-	struct amd_iommu *iommu = dev_get_drvdata(dev);
+	struct amd_iommu *iommu = dev_to_amd_iommu(dev);
 	return sprintf(buf, "%x\n", iommu->cap);
 }
 static DEVICE_ATTR(cap, S_IRUGO, amd_iommu_show_cap, NULL);
@@ -1516,7 +1516,7 @@ static ssize_t amd_iommu_show_features(struct device *dev,
 				       struct device_attribute *attr,
 				       char *buf)
 {
-	struct amd_iommu *iommu = dev_get_drvdata(dev);
+	struct amd_iommu *iommu = dev_to_amd_iommu(dev);
 	return sprintf(buf, "%llx\n", iommu->features);
 }
 static DEVICE_ATTR(features, S_IRUGO, amd_iommu_show_features, NULL);

drivers/iommu/amd_iommu_types.h

@@ -569,6 +569,11 @@ struct amd_iommu {
 	volatile u64 __aligned(8) cmd_sem;
 };
 
+static inline struct amd_iommu *dev_to_amd_iommu(struct device *dev)
+{
+	return container_of(dev, struct amd_iommu, iommu.dev);
+}
+
 #define ACPIHID_UID_LEN 256
 #define ACPIHID_HID_LEN 9