[PATCH v3 10/12] iommu/vt-d: Remove intel_svm_dev

From: Lu Baolu
Date: Tue Apr 16 2024 - 04:10:57 EST


The intel_svm_dev data structure used in the sva implementation for the
Intel IOMMU driver stores information about a device attached to an SVA
domain. It is a duplicate of dev_pasid_info that serves the same purpose.

Replace intel_svm_dev with dev_pasid_info and clean up the use of
intel_svm_dev.

Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/intel/iommu.h | 15 +----
drivers/iommu/intel/iommu.c | 7 +-
drivers/iommu/intel/svm.c | 130 ++++++++++--------------------------
3 files changed, 42 insertions(+), 110 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 31bbce8ffe7e..4f4f4f28d55d 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -650,6 +650,7 @@ struct dmar_domain {
struct list_head s2_link;
};
};
+ struct intel_svm *svm;

struct iommu_domain domain; /* generic domain data structure for
iommu core */
@@ -1150,23 +1151,13 @@ int intel_svm_finish_prq(struct intel_iommu *iommu);
void intel_svm_page_response(struct device *dev, struct iopf_fault *evt,
struct iommu_page_response *msg);
struct iommu_domain *intel_svm_domain_alloc(void);
-void intel_svm_remove_dev_pasid(struct device *dev, ioasid_t pasid);
+void intel_svm_remove_dev_pasid(struct iommu_domain *domain);
void intel_drain_pasid_prq(struct device *dev, u32 pasid);

-struct intel_svm_dev {
- struct list_head list;
- struct rcu_head rcu;
- struct device *dev;
- struct intel_iommu *iommu;
- u16 did;
- u16 sid, qdep;
-};
-
struct intel_svm {
struct mmu_notifier notifier;
struct mm_struct *mm;
u32 pasid;
- struct list_head devs;
struct dmar_domain *domain;
};
#else
@@ -1177,7 +1168,7 @@ static inline struct iommu_domain *intel_svm_domain_alloc(void)
return NULL;
}

-static inline void intel_svm_remove_dev_pasid(struct device *dev, ioasid_t pasid)
+static inline void intel_svm_remove_dev_pasid(struct iommu_domain *domain)
{
}
#endif
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index fc6303940322..0f609ba36382 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4386,11 +4386,8 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
* notification. Before consolidating that code into iommu core, let
* the intel sva code handle it.
*/
- if (domain->type == IOMMU_DOMAIN_SVA) {
- intel_svm_remove_dev_pasid(dev, pasid);
- cache_tag_unassign_domain(dmar_domain, dev, pasid);
- goto out_tear_down;
- }
+ if (domain->type == IOMMU_DOMAIN_SVA)
+ intel_svm_remove_dev_pasid(domain);

spin_lock_irqsave(&dmar_domain->lock, flags);
list_for_each_entry(curr, &dmar_domain->dev_pasids, link_domain) {
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index e6d25a0f25f6..01fa88f8b4a8 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -43,23 +43,6 @@ static void *pasid_private_find(ioasid_t pasid)
return xa_load(&pasid_private_array, pasid);
}

-static struct intel_svm_dev *
-svm_lookup_device_by_dev(struct intel_svm *svm, struct device *dev)
-{
- struct intel_svm_dev *sdev = NULL, *t;
-
- rcu_read_lock();
- list_for_each_entry_rcu(t, &svm->devs, list) {
- if (t->dev == dev) {
- sdev = t;
- break;
- }
- }
- rcu_read_unlock();
-
- return sdev;
-}
-
int intel_svm_enable_prq(struct intel_iommu *iommu)
{
struct iopf_queue *iopfq;
@@ -192,7 +175,10 @@ static void intel_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
{
struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
- struct intel_svm_dev *sdev;
+ struct dmar_domain *domain = svm->domain;
+ struct dev_pasid_info *dev_pasid;
+ struct device_domain_info *info;
+ unsigned long flags;

/* This might end up being called from exit_mmap(), *before* the page
* tables are cleared. And __mmu_notifier_release() will delete us from
@@ -206,11 +192,13 @@ static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
* page) so that we end up taking a fault that the hardware really
* *has* to handle gracefully without affecting other processes.
*/
- rcu_read_lock();
- list_for_each_entry_rcu(sdev, &svm->devs, list)
- intel_pasid_tear_down_entry(sdev->iommu, sdev->dev,
- svm->pasid, true);
- rcu_read_unlock();
+ spin_lock_irqsave(&domain->lock, flags);
+ list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
+ info = dev_iommu_priv_get(dev_pasid->dev);
+ intel_pasid_tear_down_entry(info->iommu, dev_pasid->dev,
+ dev_pasid->pasid, true);
+ }
+ spin_unlock_irqrestore(&domain->lock, flags);

}

@@ -219,47 +207,17 @@ static const struct mmu_notifier_ops intel_mmuops = {
.arch_invalidate_secondary_tlbs = intel_arch_invalidate_secondary_tlbs,
};

-static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
- struct intel_svm **rsvm,
- struct intel_svm_dev **rsdev)
-{
- struct intel_svm_dev *sdev = NULL;
- struct intel_svm *svm;
-
- if (pasid == IOMMU_PASID_INVALID || pasid >= PASID_MAX)
- return -EINVAL;
-
- svm = pasid_private_find(pasid);
- if (IS_ERR(svm))
- return PTR_ERR(svm);
-
- if (!svm)
- goto out;
-
- /*
- * If we found svm for the PASID, there must be at least one device
- * bond.
- */
- if (WARN_ON(list_empty(&svm->devs)))
- return -EINVAL;
- sdev = svm_lookup_device_by_dev(svm, dev);
-
-out:
- *rsvm = svm;
- *rsdev = sdev;
-
- return 0;
-}
-
static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
struct device *dev, ioasid_t pasid)
{
struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
struct intel_iommu *iommu = info->iommu;
struct mm_struct *mm = domain->mm;
- struct intel_svm_dev *sdev;
+ struct dev_pasid_info *dev_pasid;
struct intel_svm *svm;
unsigned long sflags;
+ unsigned long flags;
int ret = 0;

svm = pasid_private_find(pasid);
@@ -270,7 +228,6 @@ static int intel_svm_set_dev_pasid(struct iommu_domain *domain,

svm->pasid = pasid;
svm->mm = mm;
- INIT_LIST_HEAD_RCU(&svm->devs);

svm->notifier.ops = &intel_mmuops;
svm->domain = to_dmar_domain(domain);
@@ -288,25 +245,17 @@ static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
}
}

- sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
- if (!sdev) {
- ret = -ENOMEM;
+ dmar_domain->svm = svm;
+ dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
+ if (!dev_pasid)
goto free_svm;
- }

- sdev->dev = dev;
- sdev->iommu = iommu;
- sdev->did = FLPT_DEFAULT_DID;
- sdev->sid = PCI_DEVID(info->bus, info->devfn);
- if (info->ats_enabled) {
- sdev->qdep = info->ats_qdep;
- if (sdev->qdep >= QI_DEV_EIOTLB_MAX_INVS)
- sdev->qdep = 0;
- }
+ dev_pasid->dev = dev;
+ dev_pasid->pasid = pasid;

ret = cache_tag_assign_domain(to_dmar_domain(domain), dev, pasid);
if (ret)
- goto free_sdev;
+ goto free_dev_pasid;

/* Setup the pasid table: */
sflags = cpu_feature_enabled(X86_FEATURE_LA57) ? PASID_FLAG_FL5LP : 0;
@@ -315,16 +264,18 @@ static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
if (ret)
goto unassign_tag;

- list_add_rcu(&sdev->list, &svm->devs);
+ spin_lock_irqsave(&dmar_domain->lock, flags);
+ list_add(&dev_pasid->link_domain, &dmar_domain->dev_pasids);
+ spin_unlock_irqrestore(&dmar_domain->lock, flags);

return 0;

unassign_tag:
cache_tag_unassign_domain(to_dmar_domain(domain), dev, pasid);
-free_sdev:
- kfree(sdev);
+free_dev_pasid:
+ kfree(dev_pasid);
free_svm:
- if (list_empty(&svm->devs)) {
+ if (list_empty(&dmar_domain->dev_pasids)) {
mmu_notifier_unregister(&svm->notifier, mm);
pasid_private_remove(pasid);
kfree(svm);
@@ -333,26 +284,17 @@ static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
return ret;
}

-void intel_svm_remove_dev_pasid(struct device *dev, u32 pasid)
+void intel_svm_remove_dev_pasid(struct iommu_domain *domain)
{
- struct intel_svm_dev *sdev;
- struct intel_svm *svm;
- struct mm_struct *mm;
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ struct intel_svm *svm = dmar_domain->svm;
+ struct mm_struct *mm = domain->mm;

- if (pasid_to_svm_sdev(dev, pasid, &svm, &sdev))
- return;
- mm = svm->mm;
-
- if (sdev) {
- list_del_rcu(&sdev->list);
- kfree_rcu(sdev, rcu);
-
- if (list_empty(&svm->devs)) {
- if (svm->notifier.ops)
- mmu_notifier_unregister(&svm->notifier, mm);
- pasid_private_remove(svm->pasid);
- kfree(svm);
- }
+ if (list_empty(&dmar_domain->dev_pasids)) {
+ if (svm->notifier.ops)
+ mmu_notifier_unregister(&svm->notifier, mm);
+ pasid_private_remove(svm->pasid);
+ kfree(svm);
}
}

@@ -740,8 +682,10 @@ struct iommu_domain *intel_svm_domain_alloc(void)
return NULL;
domain->domain.ops = &intel_svm_domain_ops;
domain->use_first_level = true;
+ INIT_LIST_HEAD(&domain->dev_pasids);
INIT_LIST_HEAD(&domain->cache_tags);
spin_lock_init(&domain->cache_lock);
+ spin_lock_init(&domain->lock);

return &domain->domain;
}
--
2.34.1