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Message-ID: <20230621063825.268890-10-mshavit@google.com>
Date: Wed, 21 Jun 2023 14:37:21 +0800
From: Michael Shavit <mshavit@...gle.com>
To: Will Deacon <will@...nel.org>, Robin Murphy <robin.murphy@....com>,
Joerg Roedel <joro@...tes.org>
Cc: Michael Shavit <mshavit@...gle.com>, jean-philippe@...aro.org,
nicolinc@...dia.com, jgg@...dia.com, baolu.lu@...ux.intel.com,
linux-arm-kernel@...ts.infradead.org, iommu@...ts.linux.dev,
linux-kernel@...r.kernel.org
Subject: [PATCH v4 09/13] iommu/arm-smmu-v3: Implement set_dev_pasid
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@...gle.com>
---
v1->v2: Add missing atc invalidation when detaching with pasid
---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 167 +++++++++++++++++---
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h | 1 +
2 files changed, 149 insertions(+), 19 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 0a5e875abda86..b928997d35ed3 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c
@@ -2173,6 +2173,10 @@ static int arm_smmu_domain_finalise_s2(struct arm_smmu_domain *smmu_domain,
return 0;
}
+/*
+ * master may be null for domain types that are finalized before being attached
+ * to a master.
+ */
static int arm_smmu_domain_finalise(struct iommu_domain *domain,
struct arm_smmu_master *master)
{
@@ -2369,6 +2373,11 @@ 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;
@@ -2411,6 +2420,28 @@ static void arm_smmu_detach_dev(struct arm_smmu_master *master)
arm_smmu_install_ste_for_dev(master);
}
+/*
+ * Once attached for the first time, a domain can no longer be attached to any
+ * master with a distinct upstream SMMU.
+ */
+static int arm_smmu_prepare_domain_for_smmu(struct arm_smmu_device *smmu,
+ struct arm_smmu_domain *smmu_domain)
+{
+ 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, NULL);
+ 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;
@@ -2426,6 +2457,10 @@ 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);
+ 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
@@ -2436,22 +2471,18 @@ 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;
- goto out_unlock;
- }
- } else if (smmu_domain->smmu != smmu) {
- ret = -EINVAL;
- goto out_unlock;
+ /*
+ * 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;
}
+ arm_smmu_detach_dev(master);
+
if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
master->s1_cfg = &master->owned_s1_cfg;
ret = arm_smmu_write_ctx_desc(
@@ -2460,7 +2491,7 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
0, &smmu_domain->cd);
if (ret) {
master->s1_cfg = NULL;
- goto out_unlock;
+ return ret;
}
} else if (smmu_domain->stage == ARM_SMMU_DOMAIN_S2 ||
smmu_domain->stage == ARM_SMMU_DOMAIN_NESTED) {
@@ -2489,11 +2520,75 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev)
arm_smmu_enable_ats(master, smmu_domain);
-out_unlock:
- mutex_unlock(&smmu_domain->init_mutex);
return ret;
}
+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);
+ 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->s1_cfg || master->s2_cfg)
+ 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;
+
+ master->nr_attached_pasid_domains += 1;
+ /*
+ * 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->smmu, master->s1_cfg, master,
+ pasid, &smmu_domain->cd);
+ if (ret) {
+ mutex_unlock(&arm_smmu_asid_lock);
+ kfree(attached_domain);
+ }
+
+ spin_lock_irqsave(&smmu_domain->attached_domains_lock, flags);
+ list_add(&attached_domain->domain_head, &smmu_domain->attached_domains);
+ spin_unlock_irqrestore(&smmu_domain->attached_domains_lock, flags);
+ mutex_unlock(&arm_smmu_asid_lock);
+
+ 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)
@@ -2739,6 +2834,15 @@ 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_free_cd_tables(master->smmu, &master->owned_s1_cfg.cdcfg);
arm_smmu_disable_pasid(master);
@@ -2874,12 +2978,36 @@ 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_domains_lock, flags);
+ list_for_each_entry(attached_domain, &smmu_domain->attached_domains, domain_head) {
+ if (attached_domain->master != master ||
+ attached_domain->ssid != pasid)
+ continue;
+ list_del(&attached_domain->domain_head);
+ break;
+ }
+ spin_unlock_irqrestore(&smmu_domain->attached_domains_lock, flags);
+ arm_smmu_write_ctx_desc(master->smmu, master->s1_cfg, master, pasid,
+ NULL);
+ arm_smmu_atc_inv_master_ssid(master, pasid);
+ master->nr_attached_pasid_domains -= 1;
+ mutex_unlock(&arm_smmu_asid_lock);
}
static struct iommu_ops arm_smmu_ops = {
@@ -2899,6 +3027,7 @@ 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 6929590530367..48795a7287b69 100644
--- a/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
+++ b/drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.h
@@ -707,6 +707,7 @@ 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 */
--
2.41.0.162.gfafddb0af9-goog
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