/* * fence-array: aggregate fences to be waited together * * Copyright (C) 2016 Collabora Ltd * Copyright (C) 2016 Advanced Micro Devices, Inc. * Authors: *	Gustavo Padovan <gustavo@padovan.org> *	Christian König <christian.koenig@amd.com> * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. * * This program is distributed in the hope that it will be useful, but WITHOUT * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for * more details. */ #include <linux/export.h>#include <linux/slab.h>#include <linux/fence-array.h> static void fence_array_cb_func(struct fence *f, struct fence_cb *cb); static const char *fence_array_get_driver_name(struct fence *fence){	return "fence_array";} static const char *fence_array_get_timeline_name(struct fence *fence){	return "unbound";} static void fence_array_cb_func(struct fence *f, struct fence_cb *cb){	struct fence_array_cb *array_cb =		container_of(cb, struct fence_array_cb, cb);	struct fence_array *array = array_cb->array; 	if (atomic_dec_and_test(&array->num_pending))		fence_signal(&array->base);	fence_put(&array->base);} static bool fence_array_enable_signaling(struct fence *fence){	struct fence_array *array = to_fence_array(fence);	struct fence_array_cb *cb = (void *)(&array[1]);	unsigned i; 	for (i = 0; i < array->num_fences; ++i) {		cb[i].array = array;		/*		 * As we may report that the fence is signaled before all		 * callbacks are complete, we need to take an additional		 * reference count on the array so that we do not free it too		 * early. The core fence handling will only hold the reference		 * until we signal the array as complete (but that is now		 * insufficient).		 */		fence_get(&array->base);		if (fence_add_callback(array->fences[i], &cb[i].cb,				       fence_array_cb_func)) {			fence_put(&array->base);			if (atomic_dec_and_test(&array->num_pending))				return false;		}	} 	return true;} static bool fence_array_signaled(struct fence *fence){	struct fence_array *array = to_fence_array(fence); 	return atomic_read(&array->num_pending) <= 0;} static void fence_array_release(struct fence *fence){	struct fence_array *array = to_fence_array(fence);	unsigned i; 	for (i = 0; i < array->num_fences; ++i)		fence_put(array->fences[i]); 	kfree(array->fences);	fence_free(fence);} const struct fence_ops fence_array_ops = {	.get_driver_name = fence_array_get_driver_name,	.get_timeline_name = fence_array_get_timeline_name,	.enable_signaling = fence_array_enable_signaling,	.signaled = fence_array_signaled,	.wait = fence_default_wait,	.release = fence_array_release,}; /** * fence_array_create - Create a custom fence array * @num_fences:		[in]	number of fences to add in the array * @fences:		[in]	array containing the fences * @context:		[in]	fence context to use * @seqno:		[in]	sequence number to use * @signal_on_any	[in]	signal on any fence in the array * * Allocate a fence_array object and initialize the base fence with fence_init(). * In case of error it returns NULL. * * The caller should allocte the fences array with num_fences size * and fill it with the fences it wants to add to the object. Ownership of this * array is take and fence_put() is used on each fence on release. * * If @signal_on_any is true the fence array signals if any fence in the array * signals, otherwise it signals when all fences in the array signal. */struct fence_array *fence_array_create(int num_fences, struct fence **fences,				       u64 context, unsigned seqno,				       bool signal_on_any){	struct fence_array *array;	size_t size = sizeof(*array); 	/* Allocate the callback structures behind the array. */	size += num_fences * sizeof(struct fence_array_cb);	array = kzalloc(size, GFP_KERNEL);	if (!array)		return NULL; 	spin_lock_init(&array->lock);	fence_init(&array->base, &fence_array_ops, &array->lock,		   context, seqno); 	array->num_fences = num_fences;	atomic_set(&array->num_pending, signal_on_any ? 1 : num_fences);	array->fences = fences; 	return array;}EXPORT_SYMBOL(fence_array_create);