From: Zhen Lei <thunder.leiz...@huawei.com>
Now that io-pgtable knows how to dodge strict TLB maintenance, all
that's left to do is bridge the gap between the IOMMU core requesting
DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE for default domains, and showing the
appropriate IO_PGTABLE_QUIRK_NON_STRICT flag to alloc_io_pgtable_ops().
Signed-off-by: Zhen Lei <thunder.leiz...@huawei.com>
[rm: convert to domain attribute, tweak commit message]
Signed-off-by: Robin Murphy <robin.mur...@arm.com>
---
v8:
- Use nested switches for attrs
- Document barrier semantics
drivers/iommu/arm-smmu-v3.c | 79 ++++++++++++++++++++++++++-----------
1 file changed, 56 insertions(+), 23 deletions(-)
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index f10c852479fc..db402e8b068b 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -612,6 +612,7 @@ struct arm_smmu_domain {
struct mutex init_mutex; /* Protects smmu pointer */
struct io_pgtable_ops *pgtbl_ops;
+ bool non_strict;
enum arm_smmu_domain_stage stage;
union {
@@ -1407,6 +1408,12 @@ static void arm_smmu_tlb_inv_context(void *cookie)
cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid;
}
+ /*
+ * NOTE: when io-pgtable is in non-strict mode, we may get here with
+ * PTEs previously cleared by unmaps on the current CPU not yet visible
+ * to the SMMU. We are relying on the DSB implicit in queue_inc_prod()
+ * to guarantee those are observed before the TLBI. Do be careful, 007.
+ */
arm_smmu_cmdq_issue_cmd(smmu, &cmd);
__arm_smmu_tlb_sync(smmu);
}
@@ -1633,6 +1640,9 @@ static int arm_smmu_domain_finalise(struct iommu_domain
*domain)
if (smmu->features & ARM_SMMU_FEAT_COHERENCY)
pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
+ if (smmu_domain->non_strict)
+ pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
+
pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
if (!pgtbl_ops)
return -ENOMEM;
@@ -1934,15 +1944,27 @@ static int arm_smmu_domain_get_attr(struct iommu_domain
*domain,
{
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
- if (domain->type != IOMMU_DOMAIN_UNMANAGED)
- return -EINVAL;
-
- switch (attr) {
- case DOMAIN_ATTR_NESTING:
- *(int *)data = (smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED);
- return 0;
+ switch (domain->type) {
+ case IOMMU_DOMAIN_UNMANAGED:
+ switch (attr) {
+ case DOMAIN_ATTR_NESTING:
+ *(int *)data = (smmu_domain->stage ==
ARM_SMMU_DOMAIN_NESTED);
+ return 0;
+ default:
+ return -ENODEV;
+ }
+ break;
+ case IOMMU_DOMAIN_DMA:
+ switch (attr) {
+ case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
+ *(int *)data = smmu_domain->non_strict;
+ return 0;
+ default:
+ return -ENODEV;
+ }
+ break;
default:
- return -ENODEV;
+ return -EINVAL;
}
}
@@ -1952,26 +1974,37 @@ static int arm_smmu_domain_set_attr(struct iommu_domain
*domain,
int ret = 0;
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
- if (domain->type != IOMMU_DOMAIN_UNMANAGED)
- return -EINVAL;
-
mutex_lock(&smmu_domain->init_mutex);
- switch (attr) {
- case DOMAIN_ATTR_NESTING:
- if (smmu_domain->smmu) {
- ret = -EPERM;
- goto out_unlock;
+ switch (domain->type) {
+ case IOMMU_DOMAIN_UNMANAGED:
+ switch (attr) {
+ case DOMAIN_ATTR_NESTING:
+ if (smmu_domain->smmu) {
+ ret = -EPERM;
+ goto out_unlock;
+ }
+
+ if (*(int *)data)
+ smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED;
+ else
+ smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
+ break;
+ default:
+ ret = -ENODEV;
+ }
+ break;
+ case IOMMU_DOMAIN_DMA:
+ switch(attr) {
+ case DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE:
+ smmu_domain->non_strict = *(int *)data;
+ break;
+ default:
+ ret = -ENODEV;
}
-
- if (*(int *)data)
- smmu_domain->stage = ARM_SMMU_DOMAIN_NESTED;
- else
- smmu_domain->stage = ARM_SMMU_DOMAIN_S1;
-
break;
default:
- ret = -ENODEV;
+ ret = -EINVAL;
}
out_unlock:
--
2.19.0.dirty
