Hi Jean,
On 12/9/19 7:05 PM, Jean-Philippe Brucker wrote:
s/Propate/Propagate in the commit title.
> 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.
Isn't that use case relevant (I mean using both devices in a non SSID
use case). For platform devices you can work this around with FW but for
PCI devices?
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>
Besides, Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx>
Thanks
Eric
> ---
> 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;
>
