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Diffstat (limited to 'drivers/iommu/amd/init.c')
-rw-r--r--drivers/iommu/amd/init.c23
1 files changed, 20 insertions, 3 deletions
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c
index 958050c213f9..445a08d23fed 100644
--- a/drivers/iommu/amd/init.c
+++ b/drivers/iommu/amd/init.c
@@ -1511,7 +1511,14 @@ 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 +1527,18 @@ 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
@@ -2258,7 +2275,7 @@ 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;