diff options
| -rw-r--r-- | drivers/iommu/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/iommu/amd/init.c | 21 | ||||
| -rw-r--r-- | drivers/iommu/amd/iommu.c | 17 |
3 files changed, 33 insertions, 7 deletions
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index b0f308cb7f7c..201b2718f075 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -143,7 +143,7 @@ config AMD_IOMMU select IOMMU_API select IOMMU_IOVA select IOMMU_DMA - depends on X86_64 && PCI && ACPI + depends on X86_64 && PCI && ACPI && HAVE_CMPXCHG_DOUBLE help With this option you can enable support for AMD IOMMU hardware in your system. An IOMMU is a hardware component which provides diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index 6ebd4825e320..bf45f8e2c7ed 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -1518,7 +1518,14 @@ 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: @@ -1527,8 +1534,18 @@ 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 diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index d7b037891fb7..200ee948f6ec 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -3283,6 +3283,7 @@ out: static int modify_irte_ga(u16 devid, int index, struct irte_ga *irte, struct amd_ir_data *data) { + bool ret; struct irq_remap_table *table; struct amd_iommu *iommu; unsigned long flags; @@ -3300,10 +3301,18 @@ static int modify_irte_ga(u16 devid, int index, struct irte_ga *irte, entry = (struct irte_ga *)table->table; entry = &entry[index]; - entry->lo.fields_remap.valid = 0; - entry->hi.val = irte->hi.val; - entry->lo.val = irte->lo.val; - entry->lo.fields_remap.valid = 1; + + ret = cmpxchg_double(&entry->lo.val, &entry->hi.val, + entry->lo.val, entry->hi.val, + irte->lo.val, irte->hi.val); + /* + * We use cmpxchg16 to atomically update the 128-bit IRTE, + * and it cannot be updated by the hardware or other processors + * behind us, so the return value of cmpxchg16 should be the + * same as the old value. + */ + WARN_ON(!ret); + if (data) data->ref = entry; |