[PATCH v3 12/12] iommu/vt-d: Remove struct intel_svm

From: Lu Baolu
Date: Tue Apr 16 2024 - 04:11:40 EST

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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 and clean up
the code.

Besides, register mmu notifier callback in domain_alloc_sva() callback
which allows the memory management notifier lifetime to follow the lifetime
of the iommu_domain. Call mmu_notifier_put() in the domain free and defer
the real free to the mmu free_notifier callback.

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 | 11 +----
drivers/iommu/intel/svm.c | 99 ++++++++++---------------------------
3 files changed, 37 insertions(+), 99 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 4f4f4f28d55d..e1fb94acf0be 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 */
@@ -1150,26 +1154,16 @@ 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 0f609ba36382..bbc47b3c603c 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3682,8 +3682,6 @@ 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;
}
@@ -4381,14 +4379,6 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
goto out_tear_down;
dmar_domain = to_dmar_domain(domain);

- /*
- * 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)
- intel_svm_remove_dev_pasid(domain);
-
spin_lock_irqsave(&dmar_domain->lock, flags);
list_for_each_entry(curr, &dmar_domain->dev_pasids, link_domain) {
if (curr->dev == dev && curr->pasid == pasid) {
@@ -4623,6 +4613,7 @@ 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 01fa88f8b4a8..84d9bd543a6d 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;
@@ -156,10 +139,9 @@ 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) {
+ if (start == 0 && end == ULONG_MAX) {
cache_tag_flush_all(domain);
return;
}
@@ -174,8 +156,7 @@ 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;
@@ -202,9 +183,15 @@ static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)

}

+static void intel_mm_free_notifier(struct mmu_notifier *mn)
+{
+ kfree(container_of(mn, struct dmar_domain, notifier));
+}
+
static const struct mmu_notifier_ops intel_mmuops = {
.release = intel_mm_release,
.arch_invalidate_secondary_tlbs = intel_arch_invalidate_secondary_tlbs,
+ .free_notifier = intel_mm_free_notifier,
};

static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
@@ -215,40 +202,13 @@ 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;
@@ -274,30 +234,10 @@ static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
cache_tag_unassign_domain(to_dmar_domain(domain), 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 {
@@ -665,7 +605,10 @@ 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);
+
+ /* dmar_domain free is deferred to the mmu free_notifier callback. */
+ mmu_notifier_put(&dmar_domain->notifier);
}

static const struct iommu_domain_ops intel_svm_domain_ops = {
@@ -673,13 +616,16 @@ 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);
@@ -687,5 +633,12 @@ 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

Next message: Xu, Baojun: "Re: [EXTERNAL] Re: [PATCH v2 1/3] ALSA: hda/tas2781: Modification for add tas2781 driver for SPI"
Previous message: Lu Baolu: "[PATCH v3 11/12] iommu: Add ops->domain_alloc_sva()"
In reply to: Lu Baolu: "[PATCH v3 11/12] iommu: Add ops->domain_alloc_sva()"
Next in thread: Tian, Kevin: "RE: [PATCH v3 00/12] Consolidate domain cache invalidation"
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