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Diffstat (limited to 'drivers/iommu/arm-smmu.c')
-rw-r--r--drivers/iommu/arm-smmu.c135
1 files changed, 110 insertions, 25 deletions
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 60558f794922..6cd47b75286f 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -404,9 +404,16 @@ struct arm_smmu_cfg {
#define ARM_SMMU_CB_ASID(cfg) ((cfg)->cbndx)
#define ARM_SMMU_CB_VMID(cfg) ((cfg)->cbndx + 1)
+enum arm_smmu_domain_stage {
+ ARM_SMMU_DOMAIN_S1 = 0,
+ ARM_SMMU_DOMAIN_S2,
+ ARM_SMMU_DOMAIN_NESTED,
+};
+
struct arm_smmu_domain {
struct arm_smmu_device *smmu;
struct arm_smmu_cfg cfg;
+ enum arm_smmu_domain_stage stage;
spinlock_t lock;
};
@@ -906,19 +913,46 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
if (smmu_domain->smmu)
goto out_unlock;
- if (smmu->features & ARM_SMMU_FEAT_TRANS_NESTED) {
+ /*
+ * Mapping the requested stage onto what we support is surprisingly
+ * complicated, mainly because the spec allows S1+S2 SMMUs without
+ * support for nested translation. That means we end up with the
+ * following table:
+ *
+ * Requested Supported Actual
+ * S1 N S1
+ * S1 S1+S2 S1
+ * S1 S2 S2
+ * S1 S1 S1
+ * N N N
+ * N S1+S2 S2
+ * N S2 S2
+ * N S1 S1
+ *
+ * Note that you can't actually request stage-2 mappings.
+ */
+ if (!(smmu->features & ARM_SMMU_FEAT_TRANS_S1))
+ smmu_domain->stage = ARM_SMMU_DOMAIN_S2;
+ if (!(smmu->features & ARM_SMMU_FEAT_TRANS_S2))
+ smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
+
+ switch (smmu_domain->stage) {
+ case ARM_SMMU_DOMAIN_S1:
+ cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
+ start = smmu->num_s2_context_banks;
+ break;
+ case ARM_SMMU_DOMAIN_NESTED:
/*
* We will likely want to change this if/when KVM gets
* involved.
*/
- cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
- start = smmu->num_s2_context_banks;
- } else if (smmu->features & ARM_SMMU_FEAT_TRANS_S1) {
- cfg->cbar = CBAR_TYPE_S1_TRANS_S2_BYPASS;
- start = smmu->num_s2_context_banks;
- } else {
+ case ARM_SMMU_DOMAIN_S2:
cfg->cbar = CBAR_TYPE_S2_TRANS;
start = 0;
+ break;
+ default:
+ ret = -EINVAL;
+ goto out_unlock;
}
ret = __arm_smmu_alloc_bitmap(smmu->context_map, start,
@@ -1281,7 +1315,7 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd,
unsigned long pfn, int prot, int stage)
{
pte_t *pte, *start;
- pteval_t pteval = ARM_SMMU_PTE_PAGE | ARM_SMMU_PTE_AF | ARM_SMMU_PTE_XN;
+ pteval_t pteval = ARM_SMMU_PTE_PAGE | ARM_SMMU_PTE_AF;
if (pmd_none(*pmd)) {
/* Allocate a new set of tables */
@@ -1315,10 +1349,11 @@ static int arm_smmu_alloc_init_pte(struct arm_smmu_device *smmu, pmd_t *pmd,
pteval |= ARM_SMMU_PTE_MEMATTR_NC;
}
+ if (prot & IOMMU_NOEXEC)
+ pteval |= ARM_SMMU_PTE_XN;
+
/* If no access, create a faulting entry to avoid TLB fills */
- if (prot & IOMMU_EXEC)
- pteval &= ~ARM_SMMU_PTE_XN;
- else if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
+ if (!(prot & (IOMMU_READ | IOMMU_WRITE)))
pteval &= ~ARM_SMMU_PTE_PAGE;
pteval |= ARM_SMMU_PTE_SH_IS;
@@ -1568,6 +1603,8 @@ static bool arm_smmu_capable(enum iommu_cap cap)
return true;
case IOMMU_CAP_INTR_REMAP:
return true; /* MSIs are just memory writes */
+ case IOMMU_CAP_NOEXEC:
+ return true;
default:
return false;
}
@@ -1644,20 +1681,57 @@ static void arm_smmu_remove_device(struct device *dev)
iommu_group_remove_device(dev);
}
+static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
+ enum iommu_attr attr, void *data)
+{
+ struct arm_smmu_domain *smmu_domain = domain->priv;
+
+ switch (attr) {
+ case DOMAIN_ATTR_NESTING:
+ *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
+ return 0;
+ default:
+ return -ENODEV;
+ }
+}
+
+static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
+ enum iommu_attr attr, void *data)
+{
+ struct arm_smmu_domain *smmu_domain = domain->priv;
+
+ switch (attr) {
+ case DOMAIN_ATTR_NESTING:
+ if (smmu_domain->smmu)
+ return -EPERM;
+ if (*(int *)data)
+ smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED;
+ else
+ smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
+
+ return 0;
+ default:
+ return -ENODEV;
+ }
+}
+
static const struct iommu_ops arm_smmu_ops = {
- .capable = arm_smmu_capable,
- .domain_init = arm_smmu_domain_init,
- .domain_destroy = arm_smmu_domain_destroy,
- .attach_dev = arm_smmu_attach_dev,
- .detach_dev = arm_smmu_detach_dev,
- .map = arm_smmu_map,
- .unmap = arm_smmu_unmap,
- .iova_to_phys = arm_smmu_iova_to_phys,
- .add_device = arm_smmu_add_device,
- .remove_device = arm_smmu_remove_device,
- .pgsize_bitmap = (SECTION_SIZE |
- ARM_SMMU_PTE_CONT_SIZE |
- PAGE_SIZE),
+ .capable = arm_smmu_capable,
+ .domain_init = arm_smmu_domain_init,
+ .domain_destroy = arm_smmu_domain_destroy,
+ .attach_dev = arm_smmu_attach_dev,
+ .detach_dev = arm_smmu_detach_dev,
+ .map = arm_smmu_map,
+ .unmap = arm_smmu_unmap,
+ .map_sg = default_iommu_map_sg,
+ .iova_to_phys = arm_smmu_iova_to_phys,
+ .add_device = arm_smmu_add_device,
+ .remove_device = arm_smmu_remove_device,
+ .domain_get_attr = arm_smmu_domain_get_attr,
+ .domain_set_attr = arm_smmu_domain_set_attr,
+ .pgsize_bitmap = (SECTION_SIZE |
+ ARM_SMMU_PTE_CONT_SIZE |
+ PAGE_SIZE),
};
static void arm_smmu_device_reset(struct arm_smmu_device *smmu)
@@ -2062,7 +2136,6 @@ static int arm_smmu_device_remove(struct platform_device *pdev)
static struct platform_driver arm_smmu_driver = {
.driver = {
- .owner = THIS_MODULE,
.name = "arm-smmu",
.of_match_table = of_match_ptr(arm_smmu_of_match),
},
@@ -2072,8 +2145,20 @@ static struct platform_driver arm_smmu_driver = {
static int __init arm_smmu_init(void)
{
+ struct device_node *np;
int ret;
+ /*
+ * Play nice with systems that don't have an ARM SMMU by checking that
+ * an ARM SMMU exists in the system before proceeding with the driver
+ * and IOMMU bus operation registration.
+ */
+ np = of_find_matching_node(NULL, arm_smmu_of_match);
+ if (!np)
+ return 0;
+
+ of_node_put(np);
+
ret = platform_driver_register(&arm_smmu_driver);
if (ret)
return ret;
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.