drm/radeon: replace cs_mutex with vm_mutex v3

Try to remove or replace the cs_mutex with a
vm_mutex where it is still needed.

v2: fix locking order
v3: rebased on drm-next

Signed-off-by: Christian König <deathsimple@vodafone.de>

drivers/gpu/drm/radeon/radeon.h

@@ -159,48 +159,6 @@ static inline int radeon_atrm_get_bios_chunk(uint8_t *bios, int offset, int len)
 #endif
 bool radeon_get_bios(struct radeon_device *rdev);
 
-
-/*
- * Mutex which allows recursive locking from the same process.
- */
-struct radeon_mutex {
-	struct mutex		mutex;
-	struct task_struct	*owner;
-	int			level;
-};
-
-static inline void radeon_mutex_init(struct radeon_mutex *mutex)
-{
-	mutex_init(&mutex->mutex);
-	mutex->owner = NULL;
-	mutex->level = 0;
-}
-
-static inline void radeon_mutex_lock(struct radeon_mutex *mutex)
-{
-	if (mutex_trylock(&mutex->mutex)) {
-		/* The mutex was unlocked before, so it's ours now */
-		mutex->owner = current;
-	} else if (mutex->owner != current) {
-		/* Another process locked the mutex, take it */
-		mutex_lock(&mutex->mutex);
-		mutex->owner = current;
-	}
-	/* Otherwise the mutex was already locked by this process */
-
-	mutex->level++;
-}
-
-static inline void radeon_mutex_unlock(struct radeon_mutex *mutex)
-{
-	if (--mutex->level > 0)
-		return;
-
-	mutex->owner = NULL;
-	mutex_unlock(&mutex->mutex);
-}
-
-
 /*
  * Dummy page
  */
@@ -712,6 +670,7 @@ struct radeon_vm_funcs {
 };
 
 struct radeon_vm_manager {
+	struct mutex			lock;
 	struct list_head		lru_vm;
 	uint32_t			use_bitmap;
 	struct radeon_sa_manager	sa_manager;
@@ -1532,7 +1491,6 @@ struct radeon_device {
 	struct radeon_gem		gem;
 	struct radeon_pm		pm;
 	uint32_t			bios_scratch[RADEON_BIOS_NUM_SCRATCH];
-	struct radeon_mutex		cs_mutex;
 	struct radeon_wb		wb;
 	struct radeon_dummy_page	dummy_page;
 	bool				shutdown;

drivers/gpu/drm/radeon/radeon_cs.c

@@ -440,6 +440,7 @@ static int radeon_cs_ib_vm_chunk(struct radeon_device *rdev,
 		return r;
 	}
 
+	mutex_lock(&rdev->vm_manager.lock);
 	mutex_lock(&vm->mutex);
 	r = radeon_vm_bind(rdev, vm);
 	if (r) {
@@ -477,7 +478,8 @@ out:
 		}
 		vm->fence = radeon_fence_ref(parser->ib.fence);
 	}
-	mutex_unlock(&fpriv->vm.mutex);
+	mutex_unlock(&vm->mutex);
+	mutex_unlock(&rdev->vm_manager.lock);
 	return r;
 }
 
@@ -497,9 +499,7 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 	struct radeon_cs_parser parser;
 	int r;
 
-	radeon_mutex_lock(&rdev->cs_mutex);
 	if (!rdev->accel_working) {
-		radeon_mutex_unlock(&rdev->cs_mutex);
 		return -EBUSY;
 	}
 	/* initialize parser */
@@ -513,7 +513,6 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 		DRM_ERROR("Failed to initialize parser !\n");
 		radeon_cs_parser_fini(&parser, r);
 		r = radeon_cs_handle_lockup(rdev, r);
-		radeon_mutex_unlock(&rdev->cs_mutex);
 		return r;
 	}
 	r = radeon_cs_parser_relocs(&parser);
@@ -522,7 +521,6 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 			DRM_ERROR("Failed to parse relocation %d!\n", r);
 		radeon_cs_parser_fini(&parser, r);
 		r = radeon_cs_handle_lockup(rdev, r);
-		radeon_mutex_unlock(&rdev->cs_mutex);
 		return r;
 	}
 	r = radeon_cs_ib_chunk(rdev, &parser);
@@ -536,7 +534,6 @@ int radeon_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp)
 out:
 	radeon_cs_parser_fini(&parser, r);
 	r = radeon_cs_handle_lockup(rdev, r);
-	radeon_mutex_unlock(&rdev->cs_mutex);
 	return r;
 }
 

drivers/gpu/drm/radeon/radeon_device.c

@@ -728,7 +728,6 @@ int radeon_device_init(struct radeon_device *rdev,
 
 	/* mutex initialization are all done here so we
 	 * can recall function without having locking issues */
-	radeon_mutex_init(&rdev->cs_mutex);
 	mutex_init(&rdev->ring_lock);
 	mutex_init(&rdev->dc_hw_i2c_mutex);
 	atomic_set(&rdev->ih.lock, 0);
@@ -741,6 +740,7 @@ int radeon_device_init(struct radeon_device *rdev,
 	if (r)
 		return r;
 	/* initialize vm here */
+	mutex_init(&rdev->vm_manager.lock);
 	rdev->vm_manager.use_bitmap = 1;
 	rdev->vm_manager.max_pfn = 1 << 20;
 	INIT_LIST_HEAD(&rdev->vm_manager.lru_vm);

drivers/gpu/drm/radeon/radeon_gart.c

@@ -305,7 +305,7 @@ int radeon_vm_manager_init(struct radeon_device *rdev)
 	return r;
 }
 
-/* cs mutex must be lock */
+/* global mutex must be lock */
 static void radeon_vm_unbind_locked(struct radeon_device *rdev,
 				    struct radeon_vm *vm)
 {
@@ -356,17 +356,17 @@ int radeon_vm_manager_suspend(struct radeon_device *rdev)
 {
 	struct radeon_vm *vm, *tmp;
 
-	radeon_mutex_lock(&rdev->cs_mutex);
+	mutex_lock(&rdev->vm_manager.lock);
 	/* unbind all active vm */
 	list_for_each_entry_safe(vm, tmp, &rdev->vm_manager.lru_vm, list) {
 		radeon_vm_unbind_locked(rdev, vm);
 	}
 	rdev->vm_manager.funcs->fini(rdev);
-	radeon_mutex_unlock(&rdev->cs_mutex);
+	mutex_unlock(&rdev->vm_manager.lock);
 	return radeon_sa_bo_manager_suspend(rdev, &rdev->vm_manager.sa_manager);
 }
 
-/* cs mutex must be lock */
+/* global mutex must be locked */
 void radeon_vm_unbind(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	mutex_lock(&vm->mutex);
@@ -374,7 +374,7 @@ void radeon_vm_unbind(struct radeon_device *rdev, struct radeon_vm *vm)
 	mutex_unlock(&vm->mutex);
 }
 
-/* cs mutex must be lock & vm mutex must be lock */
+/* global and local mutex must be locked */
 int radeon_vm_bind(struct radeon_device *rdev, struct radeon_vm *vm)
 {
 	struct radeon_vm *vm_evict;
@@ -478,7 +478,7 @@ int radeon_vm_bo_add(struct radeon_device *rdev,
 	if (last_pfn > vm->last_pfn) {
 		/* release mutex and lock in right order */
 		mutex_unlock(&vm->mutex);
-		radeon_mutex_lock(&rdev->cs_mutex);
+		mutex_lock(&rdev->vm_manager.lock);
 		mutex_lock(&vm->mutex);
 		/* and check again */
 		if (last_pfn > vm->last_pfn) {
@@ -487,7 +487,7 @@ int radeon_vm_bo_add(struct radeon_device *rdev,
 			radeon_vm_unbind_locked(rdev, vm);
 			vm->last_pfn = (last_pfn + align) & ~align;
 		}
-		radeon_mutex_unlock(&rdev->cs_mutex);
+		mutex_unlock(&rdev->vm_manager.lock);
 	}
 	head = &vm->va;
 	last_offset = 0;
@@ -542,7 +542,7 @@ static u64 radeon_vm_get_addr(struct radeon_device *rdev,
 	return addr;
 }
 
-/* object have to be reserved & cs mutex took & vm mutex took */
+/* object have to be reserved & global and local mutex must be locked */
 int radeon_vm_bo_update_pte(struct radeon_device *rdev,
 			    struct radeon_vm *vm,
 			    struct radeon_bo *bo,
@@ -601,10 +601,10 @@ int radeon_vm_bo_rmv(struct radeon_device *rdev,
 	if (bo_va == NULL)
 		return 0;
 
-	radeon_mutex_lock(&rdev->cs_mutex);
+	mutex_lock(&rdev->vm_manager.lock);
 	mutex_lock(&vm->mutex);
 	radeon_vm_bo_update_pte(rdev, vm, bo, NULL);
-	radeon_mutex_unlock(&rdev->cs_mutex);
+	mutex_unlock(&rdev->vm_manager.lock);
 	list_del(&bo_va->vm_list);
 	mutex_unlock(&vm->mutex);
 	list_del(&bo_va->bo_list);
@@ -647,10 +647,10 @@ void radeon_vm_fini(struct radeon_device *rdev, struct radeon_vm *vm)
 	struct radeon_bo_va *bo_va, *tmp;
 	int r;
 
-	radeon_mutex_lock(&rdev->cs_mutex);
+	mutex_lock(&rdev->vm_manager.lock);
 	mutex_lock(&vm->mutex);
 	radeon_vm_unbind_locked(rdev, vm);
-	radeon_mutex_unlock(&rdev->cs_mutex);
+	mutex_unlock(&rdev->vm_manager.lock);
 
 	/* remove all bo */
 	r = radeon_bo_reserve(rdev->ring_tmp_bo.bo, false);

drivers/gpu/drm/radeon/radeon_gem.c

@@ -159,11 +159,9 @@ void radeon_gem_object_close(struct drm_gem_object *obj,
 static int radeon_gem_handle_lockup(struct radeon_device *rdev, int r)
 {
 	if (r == -EDEADLK) {
-		radeon_mutex_lock(&rdev->cs_mutex);
 		r = radeon_gpu_reset(rdev);
 		if (!r)
 			r = -EAGAIN;
-		radeon_mutex_unlock(&rdev->cs_mutex);
 	}
 	return r;
 }