1 files changed, 30 insertions, 49 deletions

diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 958050c213f9..1ba6b4cc56e8 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -1104,25 +1104,6 @@ static int __init add_early_maps(void)
 }
 
 /*
- * Reads the device exclusion range from ACPI and initializes the IOMMU with
- * it
- */
-static void __init set_device_exclusion_range(u16 devid, struct ivmd_header *m)
-{
-	if (!(m->flags & IVMD_FLAG_EXCL_RANGE))
-		return;
-
-	/*
-	 * Treat per-device exclusion ranges as r/w unity-mapped regions
-	 * since some buggy BIOSes might lead to the overwritten exclusion
-	 * range (exclusion_start and exclusion_length members). This
-	 * happens when there are multiple exclusion ranges (IVMD entries)
-	 * defined in ACPI table.
-	 */
-	m->flags = (IVMD_FLAG_IW | IVMD_FLAG_IR | IVMD_FLAG_UNITY_MAP);
-}
-
-/*
  * Takes a pointer to an AMD IOMMU entry in the ACPI table and
  * initializes the hardware and our data structures with it.
  */
@@ -1511,7 +1492,14 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
 			iommu->mmio_phys_end = MMIO_REG_END_OFFSET;
 		else
 			iommu->mmio_phys_end = MMIO_CNTR_CONF_OFFSET;
-		if (((h->efr_attr & (0x1 << IOMMU_FEAT_GASUP_SHIFT)) == 0))
+
+		/*
+		 * Note: GA (128-bit IRTE) mode requires cmpxchg16b supports.
+		 * GAM also requires GA mode. Therefore, we need to
+		 * check cmpxchg16b support before enabling it.
+		 */
+		if (!boot_cpu_has(X86_FEATURE_CX16) ||
+		    ((h->efr_attr & (0x1 << IOMMU_FEAT_GASUP_SHIFT)) == 0))
 			amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;
 		break;
 	case 0x11:
@@ -1520,8 +1508,18 @@ static int __init init_iommu_one(struct amd_iommu *iommu, struct ivhd_header *h)
 			iommu->mmio_phys_end = MMIO_REG_END_OFFSET;
 		else
 			iommu->mmio_phys_end = MMIO_CNTR_CONF_OFFSET;
-		if (((h->efr_reg & (0x1 << IOMMU_EFR_GASUP_SHIFT)) == 0))
+
+		/*
+		 * Note: GA (128-bit IRTE) mode requires cmpxchg16b supports.
+		 * XT, GAM also requires GA mode. Therefore, we need to
+		 * check cmpxchg16b support before enabling them.
+		 */
+		if (!boot_cpu_has(X86_FEATURE_CX16) ||
+		    ((h->efr_reg & (0x1 << IOMMU_EFR_GASUP_SHIFT)) == 0)) {
 			amd_iommu_guest_ir = AMD_IOMMU_GUEST_IR_LEGACY;
+			break;
+		}
+
 		/*
 		 * Note: Since iommu_update_intcapxt() leverages
 		 * the IOMMU MMIO access to MSI capability block registers
@@ -2056,30 +2054,6 @@ static void __init free_unity_maps(void)
 	}
 }
 
-/* called when we find an exclusion range definition in ACPI */
-static int __init init_exclusion_range(struct ivmd_header *m)
-{
-	int i;
-
-	switch (m->type) {
-	case ACPI_IVMD_TYPE:
-		set_device_exclusion_range(m->devid, m);
-		break;
-	case ACPI_IVMD_TYPE_ALL:
-		for (i = 0; i <= amd_iommu_last_bdf; ++i)
-			set_device_exclusion_range(i, m);
-		break;
-	case ACPI_IVMD_TYPE_RANGE:
-		for (i = m->devid; i <= m->aux; ++i)
-			set_device_exclusion_range(i, m);
-		break;
-	default:
-		break;
-	}
-
-	return 0;
-}
-
 /* called for unity map ACPI definition */
 static int __init init_unity_map_range(struct ivmd_header *m)
 {
@@ -2090,9 +2064,6 @@ static int __init init_unity_map_range(struct ivmd_header *m)
 	if (e == NULL)
 		return -ENOMEM;
 
-	if (m->flags & IVMD_FLAG_EXCL_RANGE)
-		init_exclusion_range(m);
-
 	switch (m->type) {
 	default:
 		kfree(e);
@@ -2116,6 +2087,16 @@ static int __init init_unity_map_range(struct ivmd_header *m)
 	e->address_end = e->address_start + PAGE_ALIGN(m->range_length);
 	e->prot = m->flags >> 1;
 
+	/*
+	 * Treat per-device exclusion ranges as r/w unity-mapped regions
+	 * since some buggy BIOSes might lead to the overwritten exclusion
+	 * range (exclusion_start and exclusion_length members). This
+	 * happens when there are multiple exclusion ranges (IVMD entries)
+	 * defined in ACPI table.
+	 */
+	if (m->flags & IVMD_FLAG_EXCL_RANGE)
+		e->prot = (IVMD_FLAG_IW | IVMD_FLAG_IR) >> 1;
+
 	DUMP_printk("%s devid_start: %02x:%02x.%x devid_end: %02x:%02x.%x"
 		    " range_start: %016llx range_end: %016llx flags: %x\n", s,
 		    PCI_BUS_NUM(e->devid_start), PCI_SLOT(e->devid_start),
@@ -2258,7 +2239,7 @@ static void iommu_enable_ga(struct amd_iommu *iommu)
 	switch (amd_iommu_guest_ir) {
 	case AMD_IOMMU_GUEST_IR_VAPIC:
 		iommu_feature_enable(iommu, CONTROL_GAM_EN);
-		/* Fall through */
+		fallthrough;
 	case AMD_IOMMU_GUEST_IR_LEGACY_GA:
 		iommu_feature_enable(iommu, CONTROL_GA_EN);
 		iommu->irte_ops = &irte_128_ops;