drm/amdgpu: Resolve VM through DRM PASID ownership

Allocate DRM PASIDs with fpriv and resolve VM lookup users through:

	PASID -> fpriv -> VM

This preserves the root BO reference and revalidation flow in
amdgpu_vm_lock_by_pasid().

The obsolete per-device vm_manager.pasids mapping is removed by the
following patch in this series.

v6:
- Allocate and publish the DRM PASID after amdgpu_vm_init() completes.
- Assign the allocated PASID to vm->pasid in the DRM open path.
- Unpublish PASID ownership before tearing down the VM in both the
  open-failure and normal file-close paths.

v5:
- Delay DRM PASID allocation until after amdgpu_vm_init() completes.

v4:
- Allocate DRM PASIDs with fpriv directly.
- Squash ownership registration and PASID lookup conversion.

Cc: Alex Deucher <alexander.deucher@amd.com>
Suggested-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

2 files changed, 44 insertions, 28 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
index b2e2e3533c69..46eabdda49f3 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c
@@ -1376,11 +1376,11 @@ int amdgpu_info_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 
 		memset(&gpuvm_fault, 0, sizeof(gpuvm_fault));
 
-		xa_lock_irqsave(&adev->vm_manager.pasids, flags);
+		amdgpu_pasid_lock(&flags);
 		gpuvm_fault.addr = vm->fault_info.addr;
 		gpuvm_fault.status = vm->fault_info.status;
 		gpuvm_fault.vmhub = vm->fault_info.vmhub;
-		xa_unlock_irqrestore(&adev->vm_manager.pasids, flags);
+		amdgpu_pasid_unlock(flags);
 
 		return copy_to_user(out, &gpuvm_fault,
 				    min((size_t)size, sizeof(gpuvm_fault))) ? -EFAULT : 0;
@@ -1465,7 +1465,7 @@ int amdgpu_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
 	struct amdgpu_device *adev = drm_to_adev(dev);
 	struct amdgpu_fpriv *fpriv;
 	struct drm_exec exec;
-	int r, pasid;
+	int r, pasid = 0;
 
 	/* Ensure IB tests are run on ring */
 	flush_delayed_work(&adev->delayed_init_work);
@@ -1488,22 +1488,23 @@ int amdgpu_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
 		goto out_suspend;
 	}
 
-	pasid = amdgpu_pasid_alloc(16, NULL);
-	if (pasid < 0) {
-		dev_warn(adev->dev, "No more PASIDs available!");
-		pasid = 0;
-	}
-
 	r = amdgpu_xcp_open_device(adev, fpriv, file_priv);
 	if (r)
 		goto error_pasid;
 
 	amdgpu_debugfs_vm_init(file_priv);
 
-	r = amdgpu_vm_init(adev, &fpriv->vm, fpriv->xcp_id, pasid);
+	r = amdgpu_vm_init(adev, &fpriv->vm, fpriv->xcp_id, 0);
 	if (r)
 		goto error_pasid;
 
+	pasid = amdgpu_pasid_alloc(16, fpriv);
+	if (pasid < 0) {
+		dev_warn(adev->dev, "No more PASIDs available!");
+		pasid = 0;
+	}
+	fpriv->vm.pasid = pasid;
+
 	drm_exec_init(&exec, DRM_EXEC_IGNORE_DUPLICATES, 0);
 	drm_exec_until_all_locked(&exec) {
 		r = amdgpu_vm_lock_pd(&fpriv->vm, &exec, 0);
@@ -1547,12 +1548,14 @@ int amdgpu_driver_open_kms(struct drm_device *dev, struct drm_file *file_priv)
 	goto out_suspend;
 
 error_vm:
+	if (pasid) {
+		amdgpu_pasid_free(pasid);
+		pasid = 0;
+	}
+
 	amdgpu_vm_fini(adev, &fpriv->vm);
 
 error_pasid:
-	if (pasid)
-		amdgpu_pasid_free(pasid);
-
 	kfree(fpriv);
 
 out_suspend:
@@ -1608,10 +1611,11 @@ void amdgpu_driver_postclose_kms(struct drm_device *dev,
 	}
 
 	amdgpu_ctx_mgr_fini(&fpriv->ctx_mgr);
-	amdgpu_vm_fini(adev, &fpriv->vm);
 
 	if (pasid)
 		amdgpu_pasid_free_delayed(pd->tbo.base.resv, pasid);
+
+	amdgpu_vm_fini(adev, &fpriv->vm);
 	amdgpu_bo_unref(&pd);
 
 	xa_for_each(&fpriv->bo_list_handles, handle, list)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index eb6a70fe79ce..146902ffc875 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2506,14 +2506,16 @@ amdgpu_vm_get_task_info_vm(struct amdgpu_vm *vm)
 struct amdgpu_task_info *
 amdgpu_vm_get_task_info_pasid(struct amdgpu_device *adev, u32 pasid)
 {
+	struct amdgpu_fpriv *fpriv;
 	struct amdgpu_task_info *ti;
 	struct amdgpu_vm *vm;
 	unsigned long flags;
 
-	xa_lock_irqsave(&adev->vm_manager.pasids, flags);
-	vm = xa_load(&adev->vm_manager.pasids, pasid);
+	amdgpu_pasid_lock(&flags);
+	fpriv = amdgpu_pasid_get_fpriv_locked(pasid);
+	vm = fpriv ? &fpriv->vm : NULL;
 	ti = amdgpu_vm_get_task_info_vm(vm);
-	xa_unlock_irqrestore(&adev->vm_manager.pasids, flags);
+	amdgpu_pasid_unlock(flags);
 
 	return ti;
 }
@@ -2935,14 +2937,16 @@ struct amdgpu_vm *amdgpu_vm_lock_by_pasid(struct amdgpu_device *adev,
 					  u32 pasid, struct drm_exec *exec)
 {
 	unsigned long irqflags;
+	struct amdgpu_fpriv *fpriv;
 	struct amdgpu_bo *root;
 	struct amdgpu_vm *vm;
 	int r;
 
-	xa_lock_irqsave(&adev->vm_manager.pasids, irqflags);
-	vm = xa_load(&adev->vm_manager.pasids, pasid);
-	root = vm ? amdgpu_bo_ref(vm->root.bo) : NULL;
-	xa_unlock_irqrestore(&adev->vm_manager.pasids, irqflags);
+	amdgpu_pasid_lock(&irqflags);
+	fpriv = amdgpu_pasid_get_fpriv_locked(pasid);
+	vm = fpriv ? &fpriv->vm : NULL;
+	root = vm && vm->root.bo ? amdgpu_bo_ref(vm->root.bo) : NULL;
+	amdgpu_pasid_unlock(irqflags);
 
 	if (!root)
 		return NULL;
@@ -2954,11 +2958,17 @@ struct amdgpu_vm *amdgpu_vm_lock_by_pasid(struct amdgpu_device *adev,
 	}
 
 	/* Double check that the VM still exists */
-	xa_lock_irqsave(&adev->vm_manager.pasids, irqflags);
-	vm = xa_load(&adev->vm_manager.pasids, pasid);
-	if (vm && vm->root.bo != root)
+	amdgpu_pasid_lock(&irqflags);
+	fpriv = amdgpu_pasid_get_fpriv_locked(pasid);
+	if (!fpriv) {
 		vm = NULL;
-	xa_unlock_irqrestore(&adev->vm_manager.pasids, irqflags);
+	} else {
+		vm = &fpriv->vm;
+		if (vm->root.bo != root)
+			vm = NULL;
+	}
+	amdgpu_pasid_unlock(irqflags);
+
 	if (!vm) {
 		drm_exec_unlock_obj(exec, &root->tbo.base);
 		amdgpu_bo_unref(&root);
@@ -3155,12 +3165,14 @@ void amdgpu_vm_update_fault_cache(struct amdgpu_device *adev,
 				  uint32_t status,
 				  unsigned int vmhub)
 {
+	struct amdgpu_fpriv *fpriv;
 	struct amdgpu_vm *vm;
 	unsigned long flags;
 
-	xa_lock_irqsave(&adev->vm_manager.pasids, flags);
+	amdgpu_pasid_lock(&flags);
 
-	vm = xa_load(&adev->vm_manager.pasids, pasid);
+	fpriv = amdgpu_pasid_get_fpriv_locked(pasid);
+	vm = fpriv ? &fpriv->vm : NULL;
 	/* Don't update the fault cache if status is 0.  In the multiple
 	 * fault case, subsequent faults will return a 0 status which is
 	 * useless for userspace and replaces the useful fault status, so
@@ -3193,7 +3205,7 @@ void amdgpu_vm_update_fault_cache(struct amdgpu_device *adev,
 			WARN_ONCE(1, "Invalid vmhub %u\n", vmhub);
 		}
 	}
-	xa_unlock_irqrestore(&adev->vm_manager.pasids, flags);
+	amdgpu_pasid_unlock(flags);
 }
 
 void amdgpu_vm_print_task_info(struct amdgpu_device *adev,