Add a list of compatible strings for devices that wish to opt out of attaching to a DMA domain. This is for devices that prefer to manage their own IOMMU space for any number of reasons. Returning -ENOTSUPP for attach device will filter down and force arch_setup_dma_ops() to not set up the iommu DMA ops. Later the client device in question can set up and attach their own domain.
Signed-off-by: Jordan Crouse jcrouse@codeaurora.org --- drivers/iommu/arm-smmu.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 100797a07be0..df6e4eacf727 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -1080,6 +1080,7 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain, goto out_unlock;
cfg->cbndx = ret; + if (smmu->version < ARM_SMMU_V2) { cfg->irptndx = atomic_inc_return(&smmu->irptndx); cfg->irptndx %= smmu->num_context_irqs; @@ -1450,6 +1451,15 @@ static int arm_smmu_domain_add_master(struct arm_smmu_domain *smmu_domain, return 0; }
+/* + * This is a list of compatible strings for devices that wish to manage their + * own IOMMU space instead of the DMA IOMMU ops. Devices on this list will not + * allow themselves to be attached to a IOMMU_DOMAIN_DMA domain + */ +static const char *arm_smmu_dma_blacklist[] = { + "qcom,adreno", +}; + static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) { int ret; @@ -1472,6 +1482,20 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) if (!fwspec->iommu_priv) return -ENODEV;
+ /* + * If this is the dfeault DMA domain, check to see if the device is on + * the blacklist and reject if so + */ + if (domain->type == IOMMU_DOMAIN_DMA && dev->of_node) { + int i; + + for(i = 0; i < ARRAY_SIZE(arm_smmu_dma_blacklist); i++) { + if (of_device_is_compatible(dev->of_node, + arm_smmu_dma_blacklist[i])) + return -ENOTSUPP; + } + } + smmu = fwspec_smmu(fwspec); /* Ensure that the domain is finalised */ ret = arm_smmu_init_domain_context(domain, smmu);