From: Robin Murphy <robin.murphy@arm.com>
Date: Thu, 20 Sep 2018 17:10:27 +0100
Subject: iommu/arm-smmu: Support non-strict mode
Git-commit: 44f6876a00e83df5fd28681502b19b0f51e4a3c6
Patch-mainline: v4.20-rc1
References: fate#326252
All we need is to wire up .flush_iotlb_all properly and implement the
domain attribute, and iommu-dma and io-pgtable will do the rest for us.
The only real subtlety is documenting the barrier semantics we're
introducing between io-pgtable and the drivers for non-strict flushes.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
drivers/iommu/arm-smmu.c | 93 +++++++++++++++++++++++++++++++++--------------
1 file changed, 66 insertions(+), 27 deletions(-)
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -438,6 +438,7 @@ struct arm_smmu_domain {
const struct iommu_gather_ops *tlb_ops;
struct arm_smmu_cfg cfg;
enum arm_smmu_domain_stage stage;
+ bool non_strict;
struct mutex init_mutex; /* Protects smmu pointer */
spinlock_t cb_lock; /* Serialises ATS1* ops and TLB syncs */
struct iommu_domain domain;
@@ -639,7 +640,11 @@ static void arm_smmu_tlb_inv_context_s1(
struct arm_smmu_cfg *cfg = &smmu_domain->cfg;
void __iomem *base = ARM_SMMU_CB(smmu_domain->smmu, cfg->cbndx);
- writel_relaxed(cfg->asid, base + ARM_SMMU_CB_S1_TLBIASID);
+ /*
+ * NOTE: this is not a relaxed write; it needs to guarantee that PTEs
+ * cleared by the current CPU are visible to the SMMU before the TLBI.
+ */
+ writel(cfg->asid, base + ARM_SMMU_CB_S1_TLBIASID);
arm_smmu_tlb_sync_context(cookie);
}
@@ -649,7 +654,8 @@ static void arm_smmu_tlb_inv_context_s2(
struct arm_smmu_device *smmu = smmu_domain->smmu;
void __iomem *base = ARM_SMMU_GR0(smmu);
- writel_relaxed(smmu_domain->cfg.vmid, base + ARM_SMMU_GR0_TLBIVMID);
+ /* NOTE: see above */
+ writel(smmu_domain->cfg.vmid, base + ARM_SMMU_GR0_TLBIVMID);
arm_smmu_tlb_sync_global(smmu);
}
@@ -1035,6 +1041,9 @@ static int arm_smmu_init_domain_context(
if (smmu->features & ARM_SMMU_FEAT_COHERENT_WALK)
pgtbl_cfg.quirks = IO_PGTABLE_QUIRK_NO_DMA;
+ if (smmu_domain->non_strict)
+ pgtbl_cfg.quirks |= IO_PGTABLE_QUIRK_NON_STRICT;
+
smmu_domain->smmu = smmu;
pgtbl_ops = alloc_io_pgtable_ops(fmt, &pgtbl_cfg, smmu_domain);
if (!pgtbl_ops) {
@@ -1424,6 +1433,14 @@ static size_t arm_smmu_unmap(struct iomm
return ops->unmap(ops, iova, size);
}
+static void arm_smmu_flush_iotlb_all(struct iommu_domain *domain)
+{
+ struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
+
+ if (smmu_domain->tlb_ops)
+ smmu_domain->tlb_ops->tlb_flush_all(smmu_domain);
+}
+
static void arm_smmu_iotlb_sync(struct iommu_domain *domain)
{
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
@@ -1636,15 +1653,27 @@ static int arm_smmu_domain_get_attr(stru
{
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;
}
}
@@ -1654,28 +1683,38 @@ static int arm_smmu_domain_set_attr(stru
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:
mutex_unlock(&smmu_domain->init_mutex);
return ret;
@@ -1729,7 +1768,7 @@ static struct iommu_ops arm_smmu_ops = {
.map = arm_smmu_map,
.unmap = arm_smmu_unmap,
.map_sg = default_iommu_map_sg,
- .flush_iotlb_all = arm_smmu_iotlb_sync,
+ .flush_iotlb_all = arm_smmu_flush_iotlb_all,
.iotlb_sync = arm_smmu_iotlb_sync,
.iova_to_phys = arm_smmu_iova_to_phys,
.add_device = arm_smmu_add_device,