iommu/vt-d: Add pasid private data helpers

We are about to use iommu_sva_alloc/free_pasid() helpers in iommu core.
That means the pasid life cycle will be managed by iommu core. Use a
local array to save the per pasid private data instead of attaching it
the real pasid.

Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210520031531.712333-1-baolu.lu@linux.intel.com
Link: https://lore.kernel.org/r/20210610020115.1637656-7-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>

diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 5165cea..82b0627 100644 (file)
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -17,6 +17,7 @@
 #include <linux/dmar.h>
 #include <linux/interrupt.h>
 #include <linux/mm_types.h>
+#include <linux/xarray.h>
 #include <linux/ioasid.h>
 #include <asm/page.h>
 #include <asm/fpu/api.h>
@@ -28,6 +29,23 @@ static void intel_svm_drain_prq(struct device *dev, u32 pasid);
 
 #define PRQ_ORDER 0
 
+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 page *pages;
@@ -224,7 +242,7 @@ static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
        if (pasid == INVALID_IOASID || pasid >= PASID_MAX)
                return -EINVAL;
 
-       svm = ioasid_find(NULL, pasid, NULL);
+       svm = pasid_private_find(pasid);
        if (IS_ERR(svm))
                return PTR_ERR(svm);
 
@@ -334,7 +352,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
                        svm->gpasid = data->gpasid;
                        svm->flags |= SVM_FLAG_GUEST_PASID;
                }
-               ioasid_set_data(data->hpasid, svm);
+               pasid_private_add(data->hpasid, svm);
                INIT_LIST_HEAD_RCU(&svm->devs);
                mmput(svm->mm);
        }
@@ -388,7 +406,7 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
        list_add_rcu(&sdev->list, &svm->devs);
  out:
        if (!IS_ERR_OR_NULL(svm) && list_empty(&svm->devs)) {
-               ioasid_set_data(data->hpasid, NULL);
+               pasid_private_remove(data->hpasid);
                kfree(svm);
        }
 
@@ -431,7 +449,7 @@ int intel_svm_unbind_gpasid(struct device *dev, u32 pasid)
                                 * the unbind, IOMMU driver will get notified
                                 * and perform cleanup.
                                 */
-                               ioasid_set_data(pasid, NULL);
+                               pasid_private_remove(pasid);
                                kfree(svm);
                        }
                }
@@ -547,8 +565,7 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
                svm = kzalloc(sizeof(*svm), GFP_KERNEL);
                if (!svm) {
                        ret = -ENOMEM;
-                       kfree(sdev);
-                       goto out;
+                       goto sdev_err;
                }
 
                if (pasid_max > intel_pasid_max_id)
@@ -556,13 +573,16 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
 
                /* Do not use PASID 0, reserved for RID to PASID */
                svm->pasid = ioasid_alloc(NULL, PASID_MIN,
-                                         pasid_max - 1, svm);
+                                         pasid_max - 1, NULL);
                if (svm->pasid == INVALID_IOASID) {
-                       kfree(svm);
-                       kfree(sdev);
                        ret = -ENOSPC;
-                       goto out;
+                       goto svm_err;
                }
+
+               ret = pasid_private_add(svm->pasid, svm);
+               if (ret)
+                       goto pasid_err;
+
                svm->notifier.ops = &intel_mmuops;
                svm->mm = mm;
                svm->flags = flags;
@@ -571,12 +591,8 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
                ret = -ENOMEM;
                if (mm) {
                        ret = mmu_notifier_register(&svm->notifier, mm);
-                       if (ret) {
-                               ioasid_put(svm->pasid);
-                               kfree(svm);
-                               kfree(sdev);
-                               goto out;
-                       }
+                       if (ret)
+                               goto priv_err;
                }
 
                spin_lock_irqsave(&iommu->lock, iflags);
@@ -590,8 +606,13 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
                if (ret) {
                        if (mm)
                                mmu_notifier_unregister(&svm->notifier, mm);
+priv_err:
+                       pasid_private_remove(svm->pasid);
+pasid_err:
                        ioasid_put(svm->pasid);
+svm_err:
                        kfree(svm);
+sdev_err:
                        kfree(sdev);
                        goto out;
                }
@@ -614,10 +635,8 @@ intel_svm_bind_mm(struct device *dev, unsigned int flags,
                                                (cpu_feature_enabled(X86_FEATURE_LA57) ?
                                                PASID_FLAG_FL5LP : 0));
                spin_unlock_irqrestore(&iommu->lock, iflags);
-               if (ret) {
-                       kfree(sdev);
-                       goto out;
-               }
+               if (ret)
+                       goto sdev_err;
        }
        list_add_rcu(&sdev->list, &svm->devs);
 success:
@@ -670,6 +689,7 @@ static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
                                        load_pasid(svm->mm, PASID_DISABLED);
                                }
                                list_del(&svm->list);
+                               pasid_private_remove(svm->pasid);
                                /* We mandate that no page faults may be outstanding
                                 * for the PASID when intel_svm_unbind_mm() is called.
                                 * If that is not obeyed, subtle errors will happen.
@@ -924,7 +944,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)
                }
                if (!svm || svm->pasid != req->pasid) {
                        rcu_read_lock();
-                       svm = ioasid_find(NULL, req->pasid, NULL);
+                       svm = pasid_private_find(req->pasid);
                        /* It *can't* go away, because the driver is not permitted
                         * to unbind the mm while any page faults are outstanding.
                         * So we only need RCU to protect the internal idr code. */