Now that we support substream IDs, initialize s1cdmax with the number of
SSID bits supported by a master and the SMMU.
Context descriptor tables are allocated once for the first master
attached to a domain. Therefore attaching multiple devices with
different SSID sizes is tricky, and we currently don't support it.
As a future improvement it would be nice to at least support attaching a
SSID-capable device to a domain that isn't using SSID, by reallocating
the SSID table. This would allow supporting a SSID-capable device that
is in the same IOMMU group as a bridge, for example. Varying SSID size
is less of a concern, since the PCIe specification "highly recommends"
that devices supporting PASID implement all 20 bits of it.
Signed-off-by: Jean-Philippe Brucker <jean-philippe@xxxxxxxxxx>
---
drivers/iommu/arm-smmu-v3.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index a01071123c34..f260abadde6d 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -2279,6 +2279,7 @@ static void arm_smmu_domain_free(struct iommu_domain *domain)
}
static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
+ struct arm_smmu_master *master,
struct io_pgtable_cfg *pgtbl_cfg)
{
int ret;
@@ -2290,6 +2291,8 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
if (asid < 0)
return asid;
+ cfg->s1cdmax = master->ssid_bits;
+
ret = arm_smmu_alloc_cd_tables(smmu_domain);
if (ret)
goto out_free_asid;
@@ -2306,6 +2309,7 @@ static int arm_smmu_domain_finalise_s1(struct arm_smmu_domain *smmu_domain,
}
static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
+ struct arm_smmu_master *master,
struct io_pgtable_cfg *pgtbl_cfg)
{
int vmid;
@@ -2322,7 +2326,8 @@ static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
return 0;
}
-static int arm_smmu_domain_finalise(struct iommu_domain *domain)
+static int arm_smmu_domain_finalise(struct iommu_domain *domain,
+ struct arm_smmu_master *master)
{
int ret;
unsigned long ias, oas;
@@ -2330,6 +2335,7 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
struct io_pgtable_cfg pgtbl_cfg;
struct io_pgtable_ops *pgtbl_ops;
int (*finalise_stage_fn)(struct arm_smmu_domain *,
+ struct arm_smmu_master *,
struct io_pgtable_cfg *);
struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain);
struct arm_smmu_device *smmu = smmu_domain->smmu;
@@ -2384,7 +2390,7 @@ static int arm_smmu_domain_finalise(struct iommu_domain *domain)
domain->geometry.aperture_end = (1UL << pgtbl_cfg.ias) - 1;
domain->geometry.force_aperture = true;
- ret = finalise_stage_fn(smmu_domain, &pgtbl_cfg);
+ ret = finalise_stage_fn(smmu_domain, master, &pgtbl_cfg);
if (ret < 0) {
free_io_pgtable_ops(pgtbl_ops);
return ret;
@@ -2537,7 +2543,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
if (!smmu_domain->smmu) {
smmu_domain->smmu = smmu;
- ret = arm_smmu_domain_finalise(domain);
+ ret = arm_smmu_domain_finalise(domain, master);
if (ret) {
smmu_domain->smmu = NULL;
goto out_unlock;
@@ -2549,6 +2555,13 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
dev_name(smmu->dev));
ret = -ENXIO;
goto out_unlock;
+ } else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1 &&
+ master->ssid_bits != smmu_domain->s1_cfg.s1cdmax) {
+ dev_err(dev,
+ "cannot attach to incompatible domain (%u SSID bits != %u)\n",
+ smmu_domain->s1_cfg.s1cdmax, master->ssid_bits);
+ ret = -EINVAL;
+ goto out_unlock;
}
master->domain = smmu_domain;
--
2.24.0
