[PATCH v2 12/12] iommu/vt-d: Retire struct intel_svm

From: Lu Baolu
Date: Tue Apr 09 2024 - 22:13:01 EST


The struct intel_svm was used for keeping attached devices info for sva
domain. Since sva domain is a kind of iommu_domain, the struct
dmar_domain should centralize all info of a sva domain, including the
info of attached devices. Therefore, retire struct intel_svm to clean up
the code.

Besides, allocate sva domain in domain_alloc_sva() callback which allows
the memory management notifier lifetime to follow the lifetime of the
iommu_domain.

Co-developed-by: Tina Zhang <tina.zhang@xxxxxxxxx>
Signed-off-by: Tina Zhang <tina.zhang@xxxxxxxxx>
Signed-off-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>
---
drivers/iommu/intel/iommu.h | 26 ++++------
drivers/iommu/intel/iommu.c | 9 +---
drivers/iommu/intel/svm.c | 94 +++++++++----------------------------
3 files changed, 32 insertions(+), 97 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 90611ec08a7c..0951be947ff9 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -649,8 +649,12 @@ struct dmar_domain {
/* link to parent domain siblings */
struct list_head s2_link;
};
+
+ /* SVA domain */
+ struct {
+ struct mmu_notifier notifier;
+ };
};
- struct intel_svm *svm;

struct iommu_domain domain; /* generic domain data structure for
iommu core */
@@ -1144,26 +1148,16 @@ int intel_svm_enable_prq(struct intel_iommu *iommu);
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 iommu_domain *domain);
+struct iommu_domain *intel_svm_domain_alloc(struct device *dev,
+ struct mm_struct *mm);
void intel_drain_pasid_prq(struct device *dev, u32 pasid);
-
-struct intel_svm {
- struct mmu_notifier notifier;
- struct mm_struct *mm;
- u32 pasid;
- struct dmar_domain *domain;
-};
#else
static inline void intel_svm_check(struct intel_iommu *iommu) {}
static inline void intel_drain_pasid_prq(struct device *dev, u32 pasid) {}
-static inline struct iommu_domain *intel_svm_domain_alloc(void)
-{
- return NULL;
-}
-
-static inline void intel_svm_remove_dev_pasid(struct iommu_domain *domain)
+static inline struct iommu_domain *intel_svm_domain_alloc(struct device *dev,
+ struct mm_struct *mm)
{
+ return ERR_PTR(-ENODEV);
}
#endif

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index d7f205cd0aac..b8a0f759a24f 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3680,8 +3680,6 @@ static struct iommu_domain *intel_iommu_domain_alloc(unsigned type)
return domain;
case IOMMU_DOMAIN_IDENTITY:
return &si_domain->domain;
- case IOMMU_DOMAIN_SVA:
- return intel_svm_domain_alloc();
default:
return NULL;
}
@@ -4388,14 +4386,8 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
WARN_ON_ONCE(!dev_pasid);
spin_unlock_irqrestore(&dmar_domain->lock, flags);

- /*
- * The SVA implementation needs to handle its own stuffs like the mm
- * notification. Before consolidating that code into iommu core, let
- * the intel sva code handle it.
- */
if (domain->type == IOMMU_DOMAIN_SVA) {
cache_tag_unassign_domain(dmar_domain, FLPT_DEFAULT_DID, dev, pasid);
- intel_svm_remove_dev_pasid(domain);
} else {
did = domain_id_iommu(dmar_domain, iommu);
cache_tag_unassign_domain(dmar_domain, did, dev, pasid);
@@ -4624,6 +4616,7 @@ const struct iommu_ops intel_iommu_ops = {
.hw_info = intel_iommu_hw_info,
.domain_alloc = intel_iommu_domain_alloc,
.domain_alloc_user = intel_iommu_domain_alloc_user,
+ .domain_alloc_sva = intel_svm_domain_alloc,
.probe_device = intel_iommu_probe_device,
.probe_finalize = intel_iommu_probe_finalize,
.release_device = intel_iommu_release_device,
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 0b767d16fb71..47e475f67046 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -26,23 +26,6 @@

static irqreturn_t prq_event_thread(int irq, void *d);

-static DEFINE_XARRAY_ALLOC(pasid_private_array);
-static int pasid_private_add(ioasid_t pasid, void *priv)
-{
- return xa_alloc(&pasid_private_array, &pasid, priv,
- XA_LIMIT(pasid, pasid), GFP_ATOMIC);
-}
-
-static void pasid_private_remove(ioasid_t pasid)
-{
- xa_erase(&pasid_private_array, pasid);
-}
-
-static void *pasid_private_find(ioasid_t pasid)
-{
- return xa_load(&pasid_private_array, pasid);
-}
-
int intel_svm_enable_prq(struct intel_iommu *iommu)
{
struct iopf_queue *iopfq;
@@ -156,8 +139,7 @@ static void intel_arch_invalidate_secondary_tlbs(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start, unsigned long end)
{
- struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
- struct dmar_domain *domain = svm->domain;
+ struct dmar_domain *domain = container_of(mn, struct dmar_domain, notifier);

if (start == 0 && end == -1UL) {
cache_tag_flush_all(domain);
@@ -169,8 +151,7 @@ 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 dmar_domain *domain = svm->domain;
+ struct dmar_domain *domain = container_of(mn, struct dmar_domain, notifier);
struct dev_pasid_info *dev_pasid;
struct device_domain_info *info;
unsigned long flags;
@@ -210,41 +191,13 @@ static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
struct intel_iommu *iommu = info->iommu;
struct mm_struct *mm = domain->mm;
struct dev_pasid_info *dev_pasid;
- struct intel_svm *svm;
unsigned long sflags;
unsigned long flags;
int ret = 0;

- svm = pasid_private_find(pasid);
- if (!svm) {
- svm = kzalloc(sizeof(*svm), GFP_KERNEL);
- if (!svm)
- return -ENOMEM;
-
- svm->pasid = pasid;
- svm->mm = mm;
-
- svm->notifier.ops = &intel_mmuops;
- svm->domain = to_dmar_domain(domain);
- ret = mmu_notifier_register(&svm->notifier, mm);
- if (ret) {
- kfree(svm);
- return ret;
- }
-
- ret = pasid_private_add(svm->pasid, svm);
- if (ret) {
- mmu_notifier_unregister(&svm->notifier, mm);
- kfree(svm);
- return ret;
- }
- }
-
- dmar_domain->svm = svm;
-
dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
if (!dev_pasid)
- goto free_svm;
+ return -ENOMEM;

dev_pasid->dev = dev;
dev_pasid->pasid = pasid;
@@ -272,30 +225,10 @@ static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
FLPT_DEFAULT_DID, dev, pasid);
free_dev_pasid:
kfree(dev_pasid);
-free_svm:
- if (list_empty(&dmar_domain->dev_pasids)) {
- mmu_notifier_unregister(&svm->notifier, mm);
- pasid_private_remove(pasid);
- kfree(svm);
- }

return ret;
}

-void intel_svm_remove_dev_pasid(struct iommu_domain *domain)
-{
- struct dmar_domain *dmar_domain = to_dmar_domain(domain);
- struct intel_svm *svm = dmar_domain->svm;
- struct mm_struct *mm = domain->mm;
-
- if (list_empty(&dmar_domain->dev_pasids)) {
- if (svm->notifier.ops)
- mmu_notifier_unregister(&svm->notifier, mm);
- pasid_private_remove(svm->pasid);
- kfree(svm);
- }
-}
-
/* Page request queue descriptor */
struct page_req_dsc {
union {
@@ -663,7 +596,12 @@ void intel_svm_page_response(struct device *dev, struct iopf_fault *evt,

static void intel_svm_domain_free(struct iommu_domain *domain)
{
- kfree(to_dmar_domain(domain));
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+
+ if (dmar_domain->notifier.ops)
+ mmu_notifier_unregister(&dmar_domain->notifier, domain->mm);
+
+ kfree(dmar_domain);
}

static const struct iommu_domain_ops intel_svm_domain_ops = {
@@ -671,13 +609,16 @@ static const struct iommu_domain_ops intel_svm_domain_ops = {
.free = intel_svm_domain_free
};

-struct iommu_domain *intel_svm_domain_alloc(void)
+struct iommu_domain *intel_svm_domain_alloc(struct device *dev,
+ struct mm_struct *mm)
{
struct dmar_domain *domain;
+ int ret;

domain = kzalloc(sizeof(*domain), GFP_KERNEL);
if (!domain)
- return NULL;
+ return ERR_PTR(-ENOMEM);
+
domain->domain.ops = &intel_svm_domain_ops;
domain->use_first_level = true;
INIT_LIST_HEAD(&domain->dev_pasids);
@@ -685,5 +626,12 @@ struct iommu_domain *intel_svm_domain_alloc(void)
spin_lock_init(&domain->cache_lock);
spin_lock_init(&domain->lock);

+ domain->notifier.ops = &intel_mmuops;
+ ret = mmu_notifier_register(&domain->notifier, mm);
+ if (ret) {
+ kfree(domain);
+ return ERR_PTR(ret);
+ }
+
return &domain->domain;
}
--
2.34.1