[PATCHv7 2/7] iommu/arm-smmu: Add domain attribute for system cache
From: Sai Prakash Ranjan
Date: Fri Oct 30 2020 - 05:23:57 EST
Add iommu domain attribute for using system cache aka last level
cache by client drivers like GPU to set right attributes for caching
the hardware pagetables into the system cache.
Signed-off-by: Sai Prakash Ranjan <saiprakash.ranjan@xxxxxxxxxxxxxx>
---
drivers/iommu/arm/arm-smmu/arm-smmu.c | 17 +++++++++++++++++
drivers/iommu/arm/arm-smmu/arm-smmu.h | 1 +
include/linux/iommu.h | 1 +
3 files changed, 19 insertions(+)
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.c b/drivers/iommu/arm/arm-smmu/arm-smmu.c
index b1cf8f0abc29..070d13f80c7e 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.c
@@ -789,6 +789,9 @@ static int arm_smmu_init_domain_context(struct iommu_domain *domain,
if (smmu_domain->non_strict)
pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
+ if (smmu_domain->sys_cache)
+ pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_SYS_CACHE;
+
pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
if (!pgtbl_ops) {
ret = -ENOMEM;
@@ -1520,6 +1523,9 @@ static int arm_smmu_domain_get_attr(struct iommu_domain *domain,
case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
*(int *)data = smmu_domain->non_strict;
return 0;
+ case DOMAIN_ATTR_SYS_CACHE:
+ *((int *)data) = smmu_domain->sys_cache;
+ return 0;
default:
return -ENODEV;
}
@@ -1551,6 +1557,17 @@ static int arm_smmu_domain_set_attr(struct iommu_domain *domain,
else
smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
break;
+ case DOMAIN_ATTR_SYS_CACHE:
+ if (smmu_domain->smmu) {
+ ret = -EPERM;
+ goto out_unlock;
+ }
+
+ if (*((int *)data))
+ smmu_domain->sys_cache = true;
+ else
+ smmu_domain->sys_cache = false;
+ break;
default:
ret = -ENODEV;
}
diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu.h b/drivers/iommu/arm/arm-smmu/arm-smmu.h
index 885840f3bec8..dfc44d806671 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu.h
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu.h
@@ -373,6 +373,7 @@ struct arm_smmu_domain {
struct mutex init_mutex; /* Protects smmu pointer */
spinlock_t cb_lock; /* Serialises ATS1* ops and TLB syncs */
struct iommu_domain domain;
+ bool sys_cache;
};
struct arm_smmu_master_cfg {
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index b95a6f8db6ff..4f4bb9c6f8f6 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -118,6 +118,7 @@ enum iommu_attr {
DOMAIN_ATTR_FSL_PAMUV1,
DOMAIN_ATTR_NESTING, /* two stages of translation */
DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
+ DOMAIN_ATTR_SYS_CACHE,
DOMAIN_ATTR_MAX,
};
--
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