[PATCH RESEND v9 13/13] iommu/arm-smmu-v3: Hook up ATC invalidation to mm ops

Jean-Philippe Brucker
2020-08-17T17:22:42Z

The invalidate_range() notifier is called for any change to the address
space. Perform the required ATC invalidations.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 2 ++
.../iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c | 16 +++++++++++++++-
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 18 ++++++++++++++++--
3 files changed, 33 insertions(+), 3 deletions(-)

diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
index 6365c81a4614..baa80498ad9f 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -694,6 +694,8 @@ int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain, int ssid,
struct arm_smmu_ctx_desc *cd);
void arm_smmu_tlb_inv_asid(struct arm_smmu_device *smmu, u16 asid);
bool arm_smmu_free_asid(struct arm_smmu_ctx_desc *cd);
+int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
+ unsigned long iova, size_t size);

#ifdef CONFIG_ARM_SMMU_V3_SVA
bool arm_smmu_sva_supported(struct arm_smmu_device *smmu);
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
index fb9bfda2d192..1687aac2d96b 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3-sva.c
@@ -178,6 +178,16 @@ static void arm_smmu_free_shared_cd(struct arm_smmu_ctx_desc *cd)
}
}

+static void arm_smmu_mm_invalidate_range(struct mmu_notifier *mn,
+ struct mm_struct *mm,
+ unsigned long start, unsigned long end)
+{
+ struct arm_smmu_mmu_notifier *smmu_mn = mn_to_smmu(mn);
+
+ arm_smmu_atc_inv_domain(smmu_mn->domain, mm->pasid, start,
+ end - start + 1);
+}
+
static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
{
struct arm_smmu_mmu_notifier *smmu_mn = mn_to_smmu(mn);
@@ -196,6 +206,7 @@ static void arm_smmu_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
arm_smmu_write_ctx_desc(smmu_domain, mm->pasid, &quiet_cd);

arm_smmu_tlb_inv_asid(smmu_domain->smmu, smmu_mn->cd->asid);
+ arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, 0, 0);

smmu_mn->cleared = true;
mutex_unlock(&sva_lock);
@@ -207,6 +218,7 @@ static void arm_smmu_mmu_notifier_free(struct mmu_notifier *mn)
}

static struct mmu_notifier_ops arm_smmu_mmu_notifier_ops = {
+ .invalidate_range = arm_smmu_mm_invalidate_range,
.release = arm_smmu_mm_release,
.free_notifier = arm_smmu_mmu_notifier_free,
};
@@ -279,8 +291,10 @@ static void arm_smmu_mmu_notifier_put(struct arm_smmu_mmu_notifier *smmu_mn)
* If we went through clear(), we've already invalidated, and no
* new TLB entry can have been formed.
*/
- if (!smmu_mn->cleared)
+ if (!smmu_mn->cleared) {
arm_smmu_tlb_inv_asid(smmu_domain->smmu, cd->asid);
+ arm_smmu_atc_inv_domain(smmu_domain, mm->pasid, 0, 0);
+ }

/* Frees smmu_mn */
mmu_notifier_put(&smmu_mn->mn);
diff --git a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
index ae93cdd09eff..d85a49b41a15 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1515,6 +1515,20 @@ arm_smmu_atc_inv_to_cmd(int ssid, unsigned long iova, size_t size,
size_t inval_grain_shift = 12;
unsigned long page_start, page_end;

+ /*
+ * ATS and PASID:
+ *
+ * If substream_valid is clear, the PCIe TLP is sent without a PASID
+ * prefix. In that case all ATC entries within the address range are
+ * invalidated, including those that were requested with a PASID! There
+ * is no way to invalidate only entries without PASID.
+ *
+ * When using STRTAB_STE_1_S1DSS_SSID0 (reserving CD 0 for non-PASID
+ * traffic), translation requests without PASID create ATC entries
+ * without PASID, which must be invalidated with substream_valid clear.
+ * This has the unpleasant side-effect of invalidating all PASID-tagged
+ * ATC entries within the address range.
+ */
*cmd = (struct arm_smmu_cmdq_ent) {
.opcode = CMDQ_OP_ATC_INV,
.substream_valid = !!ssid,
@@ -1573,8 +1587,8 @@ static int arm_smmu_atc_inv_master(struct arm_smmu_master *master)
return arm_smmu_cmdq_issue_sync(master->smmu);
}

-static int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain,
- int ssid, unsigned long iova, size_t size)
+int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
+ unsigned long iova, size_t size)
{
int i;
unsigned long flags;