1 files changed, 54 insertions, 2 deletions

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 6a1f7048dacc..83d8ab2aed9f 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -257,6 +257,8 @@ static void init_device_table_dma(void);
 
 static bool amd_iommu_pre_enabled = true;
 
+static u32 amd_iommu_ivinfo __initdata;
+
 bool translation_pre_enabled(struct amd_iommu *iommu)
 {
 	return (iommu->flags & AMD_IOMMU_FLAG_TRANS_PRE_ENABLED);
@@ -296,6 +298,18 @@ int amd_iommu_get_num_iommus(void)
 	return amd_iommus_present;
 }
 
+/*
+ * For IVHD type 0x11/0x40, EFR is also available via IVHD.
+ * Default to IVHD EFR since it is available sooner
+ * (i.e. before PCI init).
+ */
+static void __init early_iommu_features_init(struct amd_iommu *iommu,
+					     struct ivhd_header *h)
+{
+	if (amd_iommu_ivinfo & IOMMU_IVINFO_EFRSUP)
+		iommu->features = h->efr_reg;
+}
+
 /* Access to l1 and l2 indexed register spaces */
 
 static u32 iommu_read_l1(struct amd_iommu *iommu, u16 l1, u8 address)
@@ -1577,6 +1591,9 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
 
 		if (h->efr_reg & BIT(IOMMU_EFR_XTSUP_SHIFT))
 			amd_iommu_xt_mode = IRQ_REMAP_X2APIC_MODE;
+
+		early_iommu_features_init(iommu, h);
+
 		break;
 	default:
 		return -EINVAL;
@@ -1770,6 +1787,35 @@ static const struct attribute_group *amd_iommu_groups[] = {
 	NULL,
 };
 
+/*
+ * Note: IVHD 0x11 and 0x40 also contains exact copy
+ * of the IOMMU Extended Feature Register [MMIO Offset 0030h].
+ * Default to EFR in IVHD since it is available sooner (i.e. before PCI init).
+ */
+static void __init late_iommu_features_init(struct amd_iommu *iommu)
+{
+	u64 features;
+
+	if (!(iommu->cap & (1 << IOMMU_CAP_EFR)))
+		return;
+
+	/* read extended feature bits */
+	features = readq(iommu->mmio_base + MMIO_EXT_FEATURES);
+
+	if (!iommu->features) {
+		iommu->features = features;
+		return;
+	}
+
+	/*
+	 * Sanity check and warn if EFR values from
+	 * IVHD and MMIO conflict.
+	 */
+	if (features != iommu->features)
+		pr_warn(FW_WARN "EFR mismatch. Use IVHD EFR (%#llx : %#llx\n).",
+			features, iommu->features);
+}
+
 static int __init iommu_init_pci(struct amd_iommu *iommu)
 {
 	int cap_ptr = iommu->cap_ptr;
@@ -1789,8 +1835,7 @@ static int __init iommu_init_pci(struct amd_iommu *iommu)
 	if (!(iommu->cap & (1 << IOMMU_CAP_IOTLB)))
 		amd_iommu_iotlb_sup = false;
 
-	/* read extended feature bits */
-	iommu->features = readq(iommu->mmio_base + MMIO_EXT_FEATURES);
+	late_iommu_features_init(iommu);
 
 	if (iommu_feature(iommu, FEATURE_GT)) {
 		int glxval;
@@ -2607,6 +2652,11 @@ static void __init free_dma_resources(void)
 	free_unity_maps();
 }
 
+static void __init ivinfo_init(void *ivrs)
+{
+	amd_iommu_ivinfo = *((u32 *)(ivrs + IOMMU_IVINFO_OFFSET));
+}
+
 /*
  * This is the hardware init function for AMD IOMMU in the system.
  * This function is called either from amd_iommu_init or from the interrupt
@@ -2661,6 +2711,8 @@ static int __init early_amd_iommu_init(void)
 	if (ret)
 		goto out;
 
+	ivinfo_init(ivrs_base);
+
 	amd_iommu_target_ivhd_type = get_highest_supported_ivhd_type(ivrs_base);
 	DUMP_printk("Using IVHD type %#x\n", amd_iommu_target_ivhd_type);