diff options
Diffstat (limited to 'drivers/iommu')
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 18 |
1 files changed, 15 insertions, 3 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index 2ffe58969944..5ecfaf29933a 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -422,6 +422,14 @@ static int dmar_map_gfx = 1; static int dmar_forcedac; static int intel_iommu_strict; static int intel_iommu_superpage = 1; +static int intel_iommu_ecs = 1; + +/* We only actually use ECS when PASID support (on the new bit 40) + * is also advertised. Some early implementations — the ones with + * PASID support on bit 28 — have issues even when we *only* use + * extended root/context tables. */ +#define ecs_enabled(iommu) (intel_iommu_ecs && ecap_ecs(iommu->ecap) && \ + ecap_pasid(iommu->ecap)) int intel_iommu_gfx_mapped; EXPORT_SYMBOL_GPL(intel_iommu_gfx_mapped); @@ -465,6 +473,10 @@ static int __init intel_iommu_setup(char *str) printk(KERN_INFO "Intel-IOMMU: disable supported super page\n"); intel_iommu_superpage = 0; + } else if (!strncmp(str, "ecs_off", 7)) { + printk(KERN_INFO + "Intel-IOMMU: disable extended context table support\n"); + intel_iommu_ecs = 0; } str += strcspn(str, ","); @@ -669,7 +681,7 @@ static inline struct context_entry *iommu_context_addr(struct intel_iommu *iommu struct context_entry *context; u64 *entry; - if (ecap_ecs(iommu->ecap)) { + if (ecs_enabled(iommu)) { if (devfn >= 0x80) { devfn -= 0x80; entry = &root->hi; @@ -806,7 +818,7 @@ static void free_context_table(struct intel_iommu *iommu) if (context) free_pgtable_page(context); - if (!ecap_ecs(iommu->ecap)) + if (!ecs_enabled(iommu)) continue; context = iommu_context_addr(iommu, i, 0x80, 0); @@ -1141,7 +1153,7 @@ static void iommu_set_root_entry(struct intel_iommu *iommu) unsigned long flag; addr = virt_to_phys(iommu->root_entry); - if (ecap_ecs(iommu->ecap)) + if (ecs_enabled(iommu)) addr |= DMA_RTADDR_RTT; raw_spin_lock_irqsave(&iommu->register_lock, flag); |