/* * 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, }; EXPORT_SYMBOL(fence_array_ops); /** * 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 allocate 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 taken 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);