[RFC v16 6/9] iommu/smmuv3: Allow stage 1 invalidation with unmanaged ASIDs

Eric Auger
2021-10-27T10:46:22Z

With nested stage support, soon we will need to invalidate
S1 contexts and ranges tagged with an unmanaged asid, this
latter being managed by the guest. So let's introduce 2 helpers
that allow to invalidate with externally managed ASIDs

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---

v15 -> v16:
- Use arm_smmu_cmdq_issue_cmd_with_sync()

v14 -> v15:
- Always send CMDQ_OP_TLBI_NH_VA and do not test
smmu_domain->smmu->features & ARM_SMMU_FEAT_E2H as the guest does
not run in hyp mode atm (Zenghui).

v13 -> v14
- Actually send the NH_ASID command (reported by Xingang Wang)
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 41 ++++++++++++++++-----
1 file changed, 32 insertions(+), 9 deletions(-)

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 bb2681581283..d5e722105624 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -1871,9 +1871,9 @@ int arm_smmu_atc_inv_domain(struct arm_smmu_domain *smmu_domain, int ssid,
}

/* IO_PGTABLE API */
-static void arm_smmu_tlb_inv_context(void *cookie)
+static void __arm_smmu_tlb_inv_context(struct arm_smmu_domain *smmu_domain,
+ int ext_asid)
{
- struct arm_smmu_domain *smmu_domain = cookie;
struct arm_smmu_device *smmu = smmu_domain->smmu;
struct arm_smmu_cmdq_ent cmd;

@@ -1884,7 +1884,12 @@ static void arm_smmu_tlb_inv_context(void *cookie)
* insertion to guarantee those are observed before the TLBI. Do be
* careful, 007.
*/
- if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
+ if (ext_asid >= 0) { /* guest stage 1 invalidation */
+ cmd.opcode = CMDQ_OP_TLBI_NH_ASID;
+ cmd.tlbi.asid = ext_asid;
+ cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid;
+ arm_smmu_cmdq_issue_cmd_with_sync(smmu, &cmd);
+ } else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
arm_smmu_tlb_inv_asid(smmu, smmu_domain->s1_cfg.cd.asid);
} else {
cmd.opcode = CMDQ_OP_TLBI_S12_VMALL;
@@ -1894,6 +1899,13 @@ static void arm_smmu_tlb_inv_context(void *cookie)
arm_smmu_atc_inv_domain(smmu_domain, 0, 0, 0);
}

+static void arm_smmu_tlb_inv_context(void *cookie)
+{
+ struct arm_smmu_domain *smmu_domain = cookie;
+
+ __arm_smmu_tlb_inv_context(smmu_domain, -1);
+}
+
static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
unsigned long iova, size_t size,
size_t granule,
@@ -1955,9 +1967,10 @@ static void __arm_smmu_tlb_inv_range(struct arm_smmu_cmdq_ent *cmd,
arm_smmu_cmdq_batch_submit(smmu, &cmds);
}

-static void arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
- size_t granule, bool leaf,
- struct arm_smmu_domain *smmu_domain)
+static void
+arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
+ size_t granule, bool leaf, int ext_asid,
+ struct arm_smmu_domain *smmu_domain)
{
struct arm_smmu_cmdq_ent cmd = {
.tlbi = {
@@ -1965,7 +1978,16 @@ static void arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
},
};

- if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
+ if (ext_asid >= 0) { /* guest stage 1 invalidation */
+ /*
+ * At the moment the guest only uses NS-EL1, to be
+ * revisited when nested virt gets supported with E2H
+ * exposed.
+ */
+ cmd.opcode = CMDQ_OP_TLBI_NH_VA;
+ cmd.tlbi.asid = ext_asid;
+ cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid;
+ } else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
cmd.opcode = smmu_domain->smmu->features & ARM_SMMU_FEAT_E2H ?
CMDQ_OP_TLBI_EL2_VA : CMDQ_OP_TLBI_NH_VA;
cmd.tlbi.asid = smmu_domain->s1_cfg.cd.asid;
@@ -1973,6 +1995,7 @@ static void arm_smmu_tlb_inv_range_domain(unsigned long iova, size_t size,
cmd.opcode = CMDQ_OP_TLBI_S2_IPA;
cmd.tlbi.vmid = smmu_domain->s2_cfg.vmid;
}
+
__arm_smmu_tlb_inv_range(&cmd, iova, size, granule, smmu_domain);

/*
@@ -2011,7 +2034,7 @@ static void arm_smmu_tlb_inv_page_nosync(struct iommu_iotlb_gather *gather,
static void arm_smmu_tlb_inv_walk(unsigned long iova, size_t size,
size_t granule, void *cookie)
{
- arm_smmu_tlb_inv_range_domain(iova, size, granule, false, cookie);
+ arm_smmu_tlb_inv_range_domain(iova, size, granule, false, -1, cookie);
}

static const struct iommu_flush_ops arm_smmu_flush_ops = {
@@ -2548,7 +2571,7 @@ static void arm_smmu_iotlb_sync(struct iommu_domain *domain,

arm_smmu_tlb_inv_range_domain(gather->start,
gather->end - gather->start + 1,
- gather->pgsize, true, smmu_domain);
+ gather->pgsize, true, -1, smmu_domain);
}

static phys_addr_t
--
2.26.3