Commit 2505ec6f authored by Jean-Philippe Brucker's avatar Jean-Philippe Brucker Committed by Will Deacon
Browse files

iommu/arm-smmu-v3: Propagate ssid_bits 



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.

Tested-by: default avatarZhangfei Gao <zhangfei.gao@linaro.org>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.com>
Reviewed-by: default avatarJonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: default avatarJean-Philippe Brucker <jean-philippe@linaro.org>
Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 87f42391

drivers/iommu/arm-smmu-v3.c

+16 −3
Original line number Diff line number Diff line
@@ -2250,6 +2250,7 @@ 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;
@@ -2262,6 +2263,8 @@ 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;
@@ -2284,6 +2287,7 @@ out_free_asid: 
}



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;
@@ -2308,7 +2312,8 @@ 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;
@@ -2316,6 +2321,7 @@ 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;
@@ -2370,7 +2376,7 @@ 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;
@@ -2523,7 +2529,7 @@ 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;
@@ -2535,6 +2541,13 @@ 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;

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