On 08/07/2019 20:00, Jordan Crouse wrote:
When DOMAIN_ATTR_SPLIT_TABLES is specified for pass ARM_64_LPAE_SPLIT_S1 to io_pgtable_ops to allocate and initialize TTBR0 and TTBR1 pagetables. v3: Moved all the pagetable specific work into io-pgtable-arm in a previous patch. Signed-off-by: Jordan Crouse <jcrouse@xxxxxxxxxxxxxx> --- drivers/iommu/arm-smmu.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c index 653b6b3..7a6b4bb 100644 --- a/drivers/iommu/arm-smmu.c +++ b/drivers/iommu/arm-smmu.c @@ -257,6 +257,7 @@ struct arm_smmu_domain { bool non_strict; struct mutex init_mutex; /* Protects smmu pointer */ spinlock_t cb_lock; /* Serialises ATS1* ops and TLB syncs */ + u32 attributes; struct iommu_domain domain; };@@ -832,7 +833,11 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,ias = smmu->va_size; oas = smmu->ipa_size; if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH64) { - fmt = ARM_64_LPAE_S1; + if (smmu_domain->attributes & + (1 << DOMAIN_ATTR_SPLIT_TABLES)) + fmt = ARM_64_LPAE_SPLIT_S1; + else + fmt = ARM_64_LPAE_S1; } else if (cfg->fmt == ARM_SMMU_CTX_FMT_AARCH32_L) { fmt = ARM_32_LPAE_S1; ias = min(ias, 32UL); @@ -1582,6 +1587,10 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain, case DOMAIN_ATTR_NESTING: *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED); return 0; + case DOMAIN_ATTR_SPLIT_TABLES: + *(int *)data = !!(smmu_domain->attributes & + (1 << DOMAIN_ATTR_SPLIT_TABLES));
I'm not really a fan of always claiming to support this but silently ignoring it depending on hardware/kernel configuration - it seems somewhat tricky to make callers properly robust against making false assumptions (e.g. consider if the system is booted with "arm-smmu.force_stage=2").
Robin.
+ return 0; default: return -ENODEV; } @@ -1622,6 +1631,11 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain, else smmu_domain->stage = ARM_SMMU_DOMAIN_S1; break; + case DOMAIN_ATTR_SPLIT_TABLES: + if (*((int *)data)) + smmu_domain->attributes |= + (1 << DOMAIN_ATTR_SPLIT_TABLES); + break; default: ret = -ENODEV; }
