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// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause /* Copyright (c) 2010-2012 Broadcom. All rights reserved. */ #include "vchiq_util.h" static inline int is_pow2(int i) { return i && !(i & (i - 1)); } int vchiu_queue_init(struct vchiu_queue *queue, int size) { WARN_ON(!is_pow2(size)); queue->size = size; queue->read = 0; queue->write = 0; queue->initialized = 1; init_completion(&queue->pop); init_completion(&queue->push); queue->storage = kcalloc(size, sizeof(struct vchiq_header *), GFP_KERNEL); if (!queue->storage) { vchiu_queue_delete(queue); return 0; } return 1; } void vchiu_queue_delete(struct vchiu_queue *queue) { kfree(queue->storage); } int vchiu_queue_is_empty(struct vchiu_queue *queue) { return queue->read == queue->write; } void vchiu_queue_push(struct vchiu_queue *queue, struct vchiq_header *header) { if (!queue->initialized) return; while (queue->write == queue->read + queue->size) { if (wait_for_completion_interruptible(&queue->pop)) flush_signals(current); } queue->storage[queue->write & (queue->size - 1)] = header; queue->write++; complete(&queue->push); } struct vchiq_header *vchiu_queue_peek(struct vchiu_queue *queue) { while (queue->write == queue->read) { if (wait_for_completion_interruptible(&queue->push)) flush_signals(current); } complete(&queue->push); // We haven't removed anything from the queue. return queue->storage[queue->read & (queue->size - 1)]; } struct vchiq_header *vchiu_queue_pop(struct vchiu_queue *queue) { struct vchiq_header *header; while (queue->write == queue->read) { if (wait_for_completion_interruptible(&queue->push)) flush_signals(current); } header = queue->storage[queue->read & (queue->size - 1)]; queue->read++; complete(&queue->pop); return header; }