iommu/arm-smmu: Implement DOMAIN_ATTR_NON_FATAL_FAULTS

Unhandled context faults should be fatal unless explicitly requested
otherwise by the client.  Implement the DOMAIN_ATTR_NON_FATAL_FAULTS
attribute for this purpose.

Change-Id: I414fcc6000a6c47b3cbf77b1098c8b7895cbb20d
Signed-off-by: Mitchel Humpherys <mitchelh@codeaurora.org>

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index eb84f2f..2337ad9 100644 (file)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -449,6 +449,7 @@ struct arm_smmu_domain {
        struct list_head                unassign_list;
        struct mutex                    assign_lock;
        struct list_head                secure_pool_list;
+       bool                            non_fatal_faults;
 };
 
 static struct iommu_ops arm_smmu_ops;
@@ -1162,6 +1163,7 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
        void __iomem *gr1_base;
        phys_addr_t phys_soft;
        u32 frsynra;
+       bool non_fatal_fault = smmu_domain->non_fatal_faults;
 
        static DEFINE_RATELIMIT_STATE(_rs,
                                      DEFAULT_RATELIMIT_INTERVAL,
@@ -1256,6 +1258,11 @@ static irqreturn_t arm_smmu_context_fault(int irq, void *dev)
                }
                ret = IRQ_NONE;
                resume = RESUME_TERMINATE;
+               if (!non_fatal_fault) {
+                       dev_err(smmu->dev,
+                               "Unhandled context faults are fatal on this domain. Going down now...\n");
+                       BUG();
+               }
        }
 
        /*
@@ -2667,6 +2674,11 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
                                        & (1 << DOMAIN_ATTR_DYNAMIC));
                ret = 0;
                break;
+       case DOMAIN_ATTR_NON_FATAL_FAULTS:
+               *((int *)data) = !!(smmu_domain->attributes
+                                   & (1 << DOMAIN_ATTR_NON_FATAL_FAULTS));
+               ret = 0;
+               break;
        default:
                ret = -ENODEV;
                break;
@@ -2774,6 +2786,10 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
                smmu_domain->cfg.cbndx = *((unsigned int *)data);
                ret = 0;
                break;
+       case DOMAIN_ATTR_NON_FATAL_FAULTS:
+               smmu_domain->non_fatal_faults = *((int *)data);
+               ret = 0;
+               break;
        default:
                ret = -ENODEV;
                break;