Messages in this thread Patch in this message | | | Date | Thu, 3 Aug 2023 18:12:24 +0800 | Subject | [PATCH v5 4/6] iommu/arm-smmu-v3: Implement set_dev_pasid | From | Michael Shavit <> |
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This change enables the use of the iommu_attach_dev_pasid API for UNMANAGED domains. The primary use-case is to allow in-kernel users of the iommu API to manage domains with PASID. This change also allows for future support of pasid in the DMA api.
Signed-off-by: Michael Shavit <mshavit@google.com> ---
Changes in v5: - Fix missing error value return in set_dev_pasid - Fix issue where nr_attached_pasid_domains isn't updated when arm_smmu_write_ctx_desc fails - Fix missing free of the attached_domain node - Split off the CD table refactor to separate patch series: https://lore.kernel.org/all/20230802163328.2623773-1-mshavit@google.com/ - Link to v4: https://lore.kernel.org/all/20230621063825.268890-1-mshavit@google.com/ - Remove districting change where a NULL master is passed to arm_smmu_prepare_domain_for_smmu
Changes in v4: - Fix build warning and error on patch 07. The error was introduced during a v1->v2 rebase and hidden by patch 09 which removed the offending line. - Link to v3: https://lore.kernel.org/all/20230614154304.2860121-1-mshavit@google.com/
Changes in v3: - Dropped the bulk of the SVA refactoring to re-work as a follow-up series. - Reworded cover letter to omit dropped changes. - Rebased on 6.4 tip - Link to v2: https://lore.kernel.org/all/20230606120854.4170244-1-mshavit@google.com/
Changes in v2: - Reworded cover letter and commits based on v1 feedback. - Split and reworked `iommu/arm-smmu-v3: Move cdtable to arm_smmu_master` - Added SVA clean-up and refactor. - A few other small bug fixes and cosmetics. - Link to v1: https://lore.kernel.org/all/20230510205054.2667898-1-mshavit@google.com/ - Add missing atc invalidation when detaching with pasid
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 156 ++++++++++++++++++-- drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 1 + 2 files changed, 141 insertions(+), 16 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 e0565c644ffdb..7b296458dafec 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c @@ -2388,6 +2388,11 @@ static int arm_smmu_enable_pasid(struct arm_smmu_master *master) return 0; } +static bool arm_smmu_master_has_pasid_domains(struct arm_smmu_master *master) +{ + return master->nr_attached_pasid_domains > 0; +} + static void arm_smmu_disable_pasid(struct arm_smmu_master *master) { struct pci_dev *pdev; @@ -2423,6 +2428,25 @@ static void arm_smmu_detach_dev(struct arm_smmu_master *master) arm_smmu_install_ste_for_dev(master); } +static int arm_smmu_prepare_domain_for_smmu(struct arm_smmu_device *smmu, + struct arm_smmu_domain *smmu_domain, + struct arm_smmu_master *master) +{ + int ret = 0; + + mutex_lock(&smmu_domain->init_mutex); + if (!smmu_domain->smmu) { + smmu_domain->smmu = smmu; + ret = arm_smmu_domain_finalise(&smmu_domain->domain, master); + if (ret) + smmu_domain->smmu = NULL; + } else if (smmu_domain->smmu != smmu) + ret = -EINVAL; + + mutex_unlock(&smmu_domain->init_mutex); + return ret; +} + static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) { int ret = 0; @@ -2438,6 +2462,10 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) master = dev_iommu_priv_get(dev); smmu = master->smmu; + ret = arm_smmu_prepare_domain_for_smmu(smmu, smmu_domain, master); + if (ret) + return ret; + /* * Checking that SVA is disabled ensures that this device isn't bound to * any mm, and can be safely detached from its old domain. Bonds cannot @@ -2448,21 +2476,17 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) return -EBUSY; } - arm_smmu_detach_dev(master); - - mutex_lock(&smmu_domain->init_mutex); - - if (!smmu_domain->smmu) { - smmu_domain->smmu = smmu; - ret = arm_smmu_domain_finalise(domain, master); - if (ret) - smmu_domain->smmu = NULL; - } else if (smmu_domain->smmu != smmu) - ret = -EINVAL; + /* + * Attaching a bypass or stage 2 domain would break any domains attached + * with pasid. Attaching an S1 domain should be feasible but requires + * more complicated logic to handle. + */ + if (arm_smmu_master_has_pasid_domains(master)) { + dev_err(dev, "cannot attach - domain attached with pasid\n"); + return -EBUSY; + } - mutex_unlock(&smmu_domain->init_mutex); - if (ret) - return ret; + arm_smmu_detach_dev(master); /* * The SMMU does not support enabling ATS with bypass. When the STE is @@ -2500,6 +2524,72 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) return 0; } +static int arm_smmu_set_dev_pasid(struct iommu_domain *domain, + struct device *dev, ioasid_t pasid) +{ + int ret = 0; + unsigned long flags; + struct iommu_fwspec *fwspec = dev_iommu_fwspec_get(dev); + struct arm_smmu_device *smmu; + struct arm_smmu_domain *smmu_domain = to_smmu_domain(domain); + struct arm_smmu_attached_domain *attached_domain; + struct arm_smmu_master *master; + + if (!fwspec) + return -ENOENT; + + master = dev_iommu_priv_get(dev); + smmu = master->smmu; + + ret = arm_smmu_prepare_domain_for_smmu(smmu, smmu_domain, master); + if (ret) + return ret; + + if (pasid == 0) { + dev_err(dev, "pasid 0 is reserved for the device's primary domain\n"); + return -ENODEV; + } + + if (smmu_domain->stage != ARM_SMMU_DOMAIN_S1) { + dev_err(dev, "set_dev_pasid only supports stage 1 domains\n"); + return -EINVAL; + } + + if (!master->cd_table.cdtab) + return -EBUSY; + + attached_domain = kzalloc(sizeof(*attached_domain), GFP_KERNEL); + if (!attached_domain) + return -ENOMEM; + + attached_domain->master = master; + attached_domain->domain = smmu_domain; + attached_domain->ssid = pasid; + + /* + * arm_smmu_share_asid may update the cd's asid value and write the + * ctx_desc for every attached_domains in the list. There's a potential + * race here regardless of whether we first write the ctx_desc or + * first insert into the domain's list. Grabbing the asic_lock prevents + * SVA from changing the cd's ASID while the cd is being attached. + */ + mutex_lock(&arm_smmu_asid_lock); + ret = arm_smmu_write_ctx_desc(master, pasid, &smmu_domain->cd); + if (ret) { + mutex_unlock(&arm_smmu_asid_lock); + kfree(attached_domain); + return ret; + } + + spin_lock_irqsave(&smmu_domain->attached_ssids_lock, flags); + list_add(&attached_domain->list, &smmu_domain->attached_ssids); + spin_unlock_irqrestore(&smmu_domain->attached_ssids_lock, flags); + mutex_unlock(&arm_smmu_asid_lock); + + master->nr_attached_pasid_domains += 1; + return 0; +} + static int arm_smmu_map_pages(struct iommu_domain *domain, unsigned long iova, phys_addr_t paddr, size_t pgsize, size_t pgcount, int prot, gfp_t gfp, size_t *mapped) @@ -2738,6 +2828,15 @@ static void arm_smmu_release_device(struct device *dev) if (WARN_ON(arm_smmu_master_sva_enabled(master))) iopf_queue_remove_device(master->smmu->evtq.iopf, dev); + if (WARN_ON(master->nr_attached_pasid_domains != 0)) { + /* + * TODO: Do we need to handle this case? + * This requires a mechanism to obtain all the pasid domains + * that this master is attached to so that we can clean up the + * domain's attached_domain list. + */ + } + arm_smmu_detach_dev(master); arm_smmu_disable_pasid(master); arm_smmu_remove_master(master); @@ -2874,12 +2973,36 @@ static int arm_smmu_def_domain_type(struct device *dev) static void arm_smmu_remove_dev_pasid(struct device *dev, ioasid_t pasid) { struct iommu_domain *domain; + struct arm_smmu_master *master = dev_iommu_priv_get(dev); + struct arm_smmu_domain *smmu_domain; + struct arm_smmu_attached_domain *attached_domain; + unsigned long flags; - domain = iommu_get_domain_for_dev_pasid(dev, pasid, IOMMU_DOMAIN_SVA); + if (!master || pasid == 0) + return; + + domain = iommu_get_domain_for_dev_pasid(dev, pasid, 0); if (WARN_ON(IS_ERR(domain)) || !domain) return; + if (domain->type == IOMMU_DOMAIN_SVA) + return arm_smmu_sva_remove_dev_pasid(domain, dev, pasid); - arm_smmu_sva_remove_dev_pasid(domain, dev, pasid); + smmu_domain = to_smmu_domain(domain); + mutex_lock(&arm_smmu_asid_lock); + spin_lock_irqsave(&smmu_domain->attached_ssids_lock, flags); + list_for_each_entry(attached_domain, &smmu_domain->attached_ssids, list) { + if (attached_domain->master != master || + attached_domain->ssid != pasid) + continue; + list_del(&attached_domain->list); + master->nr_attached_pasid_domains -= 1; + kfree(attached_domain); + break; + } + spin_unlock_irqrestore(&smmu_domain->attached_ssids_lock, flags); + arm_smmu_write_ctx_desc(master, pasid, NULL); + arm_smmu_atc_inv_master_ssid(master, pasid); + mutex_unlock(&arm_smmu_asid_lock); } static struct iommu_ops arm_smmu_ops = { @@ -2899,6 +3022,7 @@ static struct iommu_ops arm_smmu_ops = { .owner = THIS_MODULE, .default_domain_ops = &(const struct iommu_domain_ops) { .attach_dev = arm_smmu_attach_dev, + .set_dev_pasid = arm_smmu_set_dev_pasid, .map_pages = arm_smmu_map_pages, .unmap_pages = arm_smmu_unmap_pages, .flush_iotlb_all = arm_smmu_flush_iotlb_all, 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 66a492cafe2e8..433f58bd99dd2 100644 --- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h +++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h @@ -713,6 +713,7 @@ struct arm_smmu_master { bool iopf_enabled; struct list_head bonds; unsigned int ssid_bits; + unsigned int nr_attached_pasid_domains; }; /* SMMU private data for an IOMMU domain */ -- 2.41.0.585.gd2178a4bd4-goog
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