From 77253f272f01690c32b3824f5ba1016e46f6c421 Mon Sep 17 00:00:00 2001
From: Nirmoy Das <nirmoy.das@amd.com>
Date: Mon, 28 Jun 2021 23:29:39 +0200
Subject: drm/amdgpu: use xarray for storing pasid in vm
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Git-commit: dcb388eddb5f1bbc817d0e9ba341908b0a201ff2
Patch-mainline: v5.15-rc1
References: jsc#PED-1166 jsc#PED-1168 jsc#PED-1170 jsc#PED-1218 jsc#PED-1220 jsc#PED-1222 jsc#PED-1223 jsc#PED-1225

Replace idr with xarray as we actually need hash functionality.
Cleanup code related to vm pasid by adding helper function.

Signed-off-by: Nirmoy Das <nirmoy.das@amd.com>
Acked-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c | 149 ++++++++++++-------------
 drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h |   6 +-
 2 files changed, 73 insertions(+), 82 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 078c068937fe..620a224e4d7c 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -88,6 +88,46 @@ struct amdgpu_prt_cb {
 	struct dma_fence_cb cb;
 };
 
+/**
+ * amdgpu_vm_set_pasid - manage pasid and vm ptr mapping
+ *
+ * @adev: amdgpu_device pointer
+ * @vm: amdgpu_vm pointer
+ * @pasid: the pasid the VM is using on this GPU
+ *
+ * Set the pasid this VM is using on this GPU, can also be used to remove the
+ * pasid by passing in zero.
+ *
+ */
+int amdgpu_vm_set_pasid(struct amdgpu_device *adev, struct amdgpu_vm *vm,
+			u32 pasid)
+{
+	int r;
+
+	if (vm->pasid == pasid)
+		return 0;
+
+	if (vm->pasid) {
+		r = xa_err(xa_erase_irq(&adev->vm_manager.pasids, vm->pasid));
+		if (r < 0)
+			return r;
+
+		vm->pasid = 0;
+	}
+
+	if (pasid) {
+		r = xa_err(xa_store_irq(&adev->vm_manager.pasids, pasid, vm,
+					GFP_KERNEL));
+		if (r < 0)
+			return r;
+
+		vm->pasid = pasid;
+	}
+
+
+	return 0;
+}
+
 /*
  * vm eviction_lock can be taken in MMU notifiers. Make sure no reclaim-FS
  * happens while holding this lock anywhere to prevent deadlocks when
@@ -2944,18 +2984,9 @@ int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm, u32 pasid)
 
 	amdgpu_bo_unreserve(vm->root.bo);
 
-	if (pasid) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
-		r = idr_alloc(&adev->vm_manager.pasid_idr, vm, pasid, pasid + 1,
-			      GFP_ATOMIC);
-		spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
-		if (r < 0)
-			goto error_free_root;
-
-		vm->pasid = pasid;
-	}
+	r = amdgpu_vm_set_pasid(adev, vm, pasid);
+	if (r)
+		goto error_free_root;
 
 	INIT_KFIFO(vm->faults);
 
@@ -3043,18 +3074,15 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 	if (r)
 		goto unreserve_bo;
 
-	if (pasid) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
-		r = idr_alloc(&adev->vm_manager.pasid_idr, vm, pasid, pasid + 1,
-			      GFP_ATOMIC);
-		spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
+	/* Free the original amdgpu allocated pasid,
+	 * will be replaced with kfd allocated pasid.
+	 */
+	if (vm->pasid)
+		amdgpu_pasid_free(vm->pasid);
 
-		if (r == -ENOSPC)
-			goto unreserve_bo;
-		r = 0;
-	}
+	r = amdgpu_vm_set_pasid(adev, vm, pasid);
+	if (r)
+		goto unreserve_bo;
 
 	/* Check if PD needs to be reinitialized and do it before
 	 * changing any other state, in case it fails.
@@ -3065,7 +3093,7 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 				       to_amdgpu_bo_vm(vm->root.bo),
 				       false);
 		if (r)
-			goto free_idr;
+			goto free_pasid_entry;
 	}
 
 	/* Update VM state */
@@ -3082,7 +3110,7 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 		r = amdgpu_bo_sync_wait(vm->root.bo,
 					AMDGPU_FENCE_OWNER_UNDEFINED, true);
 		if (r)
-			goto free_idr;
+			goto free_pasid_entry;
 
 		vm->update_funcs = &amdgpu_vm_cpu_funcs;
 	} else {
@@ -3092,36 +3120,13 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
 	vm->last_update = NULL;
 	vm->is_compute_context = true;
 
-	if (vm->pasid) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
-		idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
-		spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
-
-		/* Free the original amdgpu allocated pasid
-		 * Will be replaced with kfd allocated pasid
-		 */
-		amdgpu_pasid_free(vm->pasid);
-		vm->pasid = 0;
-	}
-
 	/* Free the shadow bo for compute VM */
 	amdgpu_bo_unref(&to_amdgpu_bo_vm(vm->root.bo)->shadow);
 
-	if (pasid)
-		vm->pasid = pasid;
-
 	goto unreserve_bo;
 
-free_idr:
-	if (pasid) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
-		idr_remove(&adev->vm_manager.pasid_idr, pasid);
-		spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
-	}
+free_pasid_entry:
+	amdgpu_vm_set_pasid(adev, vm, 0);
 unreserve_bo:
 	amdgpu_bo_unreserve(vm->root.bo);
 	return r;
@@ -3137,14 +3142,7 @@ int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm,
  */
 void amdgpu_vm_release_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 {
-	if (vm->pasid) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
-		idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
-		spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
-	}
-	vm->pasid = 0;
+	amdgpu_vm_set_pasid(adev, vm, 0);
 	vm->is_compute_context = false;
 }
 
@@ -3168,15 +3166,7 @@ void amdgpu_vm_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
 
 	root = amdgpu_bo_ref(vm->root.bo);
 	amdgpu_bo_reserve(root, true);
-	if (vm->pasid) {
-		unsigned long flags;
-
-		spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
-		idr_remove(&adev->vm_manager.pasid_idr, vm->pasid);
-		spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
-		vm->pasid = 0;
-	}
-
+	amdgpu_vm_set_pasid(adev, vm, 0);
 	dma_fence_wait(vm->last_unlocked, false);
 	dma_fence_put(vm->last_unlocked);
 
@@ -3258,8 +3248,7 @@ void amdgpu_vm_manager_init(struct amdgpu_device *adev)
 	adev->vm_manager.vm_update_mode = 0;
 #endif
 
-	idr_init(&adev->vm_manager.pasid_idr);
-	spin_lock_init(&adev->vm_manager.pasid_lock);
+	xa_init_flags(&adev->vm_manager.pasids, XA_FLAGS_LOCK_IRQ);
 }
 
 /**
@@ -3271,8 +3260,8 @@ void amdgpu_vm_manager_init(struct amdgpu_device *adev)
  */
 void amdgpu_vm_manager_fini(struct amdgpu_device *adev)
 {
-	WARN_ON(!idr_is_empty(&adev->vm_manager.pasid_idr));
-	idr_destroy(&adev->vm_manager.pasid_idr);
+	WARN_ON(!xa_empty(&adev->vm_manager.pasids));
+	xa_destroy(&adev->vm_manager.pasids);
 
 	amdgpu_vmid_mgr_fini(adev);
 }
@@ -3341,13 +3330,13 @@ void amdgpu_vm_get_task_info(struct amdgpu_device *adev, u32 pasid,
 	struct amdgpu_vm *vm;
 	unsigned long flags;
 
-	spin_lock_irqsave(&adev->vm_manager.pasid_lock, flags);
+	xa_lock_irqsave(&adev->vm_manager.pasids, flags);
 
-	vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
+	vm = xa_load(&adev->vm_manager.pasids, pasid);
 	if (vm)
 		*task_info = vm->task_info;
 
-	spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, flags);
+	xa_unlock_irqrestore(&adev->vm_manager.pasids, flags);
 }
 
 /**
@@ -3389,15 +3378,15 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, u32 pasid,
 	struct amdgpu_vm *vm;
 	int r;
 
-	spin_lock_irqsave(&adev->vm_manager.pasid_lock, irqflags);
-	vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
+	xa_lock_irqsave(&adev->vm_manager.pasids, irqflags);
+	vm = xa_load(&adev->vm_manager.pasids, pasid);
 	if (vm) {
 		root = amdgpu_bo_ref(vm->root.bo);
 		is_compute_context = vm->is_compute_context;
 	} else {
 		root = NULL;
 	}
-	spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, irqflags);
+	xa_unlock_irqrestore(&adev->vm_manager.pasids, irqflags);
 
 	if (!root)
 		return false;
@@ -3415,11 +3404,11 @@ bool amdgpu_vm_handle_fault(struct amdgpu_device *adev, u32 pasid,
 		goto error_unref;
 
 	/* Double check that the VM still exists */
-	spin_lock_irqsave(&adev->vm_manager.pasid_lock, irqflags);
-	vm = idr_find(&adev->vm_manager.pasid_idr, pasid);
+	xa_lock_irqsave(&adev->vm_manager.pasids, irqflags);
+	vm = xa_load(&adev->vm_manager.pasids, pasid);
 	if (vm && vm->root.bo != root)
 		vm = NULL;
-	spin_unlock_irqrestore(&adev->vm_manager.pasid_lock, irqflags);
+	xa_unlock_irqrestore(&adev->vm_manager.pasids, irqflags);
 	if (!vm)
 		goto error_unlock;
 
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
index f8fa653d4da7..9c719ad98de0 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.h
@@ -359,8 +359,7 @@ struct amdgpu_vm_manager {
 	/* PASID to VM mapping, will be used in interrupt context to
 	 * look up VM of a page fault
 	 */
-	struct idr				pasid_idr;
-	spinlock_t				pasid_lock;
+	struct xarray				pasids;
 };
 
 struct amdgpu_bo_va_mapping;
@@ -375,6 +374,9 @@ extern const struct amdgpu_vm_update_funcs amdgpu_vm_sdma_funcs;
 void amdgpu_vm_manager_init(struct amdgpu_device *adev);
 void amdgpu_vm_manager_fini(struct amdgpu_device *adev);
 
+int amdgpu_vm_set_pasid(struct amdgpu_device *adev, struct amdgpu_vm *vm,
+			u32 pasid);
+
 long amdgpu_vm_wait_idle(struct amdgpu_vm *vm, long timeout);
 int amdgpu_vm_init(struct amdgpu_device *adev, struct amdgpu_vm *vm, u32 pasid);
 int amdgpu_vm_make_compute(struct amdgpu_device *adev, struct amdgpu_vm *vm, u32 pasid);
-- 
2.38.1

