iommu/vt-d: Remove struct intel_svm

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@intel.com>
Signed-off-by: Tina Zhang <tina.zhang@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Link: https://lore.kernel.org/r/20240416080656.60968-13-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 7631d00cc8825ccf11d398059734a87e29c110f9..916cdb65d84947965b31a02054474b051176c7f8 100644 (file)
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -3683,8 +3683,6 @@ 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;
        }
@@ -4382,14 +4380,6 @@ 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) {
@@ -4624,6 +4614,7 @@ 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/iommu.h b/drivers/iommu/intel/iommu.h
index f16b0d10543fb21b2e27d242cfbdd878e2fa8c4a..c9eef464cf5ceaf7692efb68087fb5447e90b278 100644 (file)
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -648,8 +648,12 @@ 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 */
@@ -1149,26 +1153,16 @@ 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/svm.c b/drivers/iommu/intel/svm.c
index e6568897042f8af5e5b5e5fde9d72faaf3794f57..268a0082d37f7c7e022a851c5d3b5fe03dc33347 100644 (file)
--- 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 @@ unassign_tag:
        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 {
@@ -611,7 +551,10 @@ 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 = {
@@ -619,13 +562,16 @@ 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);
@@ -633,5 +579,12 @@ 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;
 }