dpa_offload: Circular queue utilities used in DPA offload code

Source file for the circular queue object
Elements are put in and taken out of the queue in FIFO order
In addition any position in the queue may be read (without
affecting the contents of the queue)
The size of each item in the queue is set when the queue is initialized.

Signed-off-by: Andrei Varvara <andrei.varvara@freescale.com>
Change-Id: I70ff2a89b7c5e5deb90a2b66db8931790ea15b0d
Reviewed-on: http://git.am.freescale.net:8181/2231
Reviewed-by: Fleming Andrew-AFLEMING <AFLEMING@freescale.com>
Tested-by: Fleming Andrew-AFLEMING <AFLEMING@freescale.com>

2 files changed, 430 insertions, 0 deletions

diff --git a/drivers/staging/fsl_dpa_offload/cq.c b/drivers/staging/fsl_dpa_offload/cq.c
new file mode 100644
index 0000000..c8615a3
--- /dev/null
+++ b/drivers/staging/fsl_dpa_offload/cq.c
@@ -0,0 +1,289 @@
+/* Copyright 2008-2012 Freescale Semiconductor, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Freescale Semiconductor nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") as published by the Free Software
+ * Foundation, either version 2 of that License or (at your option) any
+ * later version.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * Source file for the Circular Queue object.
+ * Elements are put in and taken out of the queue in FIFO order.
+ * In addition any position in the queue may be read (without
+ * affecting the contents of the queue). The size of each item
+ * in the queue is set when the queue is initialized.
+ */
+
+#include "cq.h"
+
+#include <linux/slab.h>
+#include <linux/delay.h>
+
+struct cq *cq_new(int max_items, int item_size)
+{
+	struct cq *cq;
+
+	BUG_ON(!max_items);
+	BUG_ON(!item_size);
+
+	cq = kmalloc(sizeof(*cq) + max_items * item_size, GFP_KERNEL);
+	if (cq) {
+		cq->max_items = max_items;
+		cq->item_size = item_size;
+		cq->items_in_queue = 0;
+		cq->first = 0;
+		mutex_init(&cq->cq_lock);
+		memset(cq->items, 0, max_items * item_size);
+	}
+
+	return cq;
+}
+
+void cq_delete(struct cq *cq)
+{
+	BUG_ON(!cq);
+	while (mutex_is_locked(&cq->cq_lock)) {
+		udelay(100);
+		cpu_relax();
+	}
+	kfree(cq);
+}
+
+int cq_flush(struct cq *cq)
+{
+	int items_in_queue;
+
+	BUG_ON(!cq);
+
+	/* Acquire circular queue lock */
+	mutex_lock(&cq->cq_lock);
+
+	items_in_queue = cq->items_in_queue;
+	cq->first = 0;
+	cq->items_in_queue = 0;
+	memset(cq->items, 0, cq->max_items * cq->item_size);
+
+	/* Release circular queue lock */
+	mutex_unlock(&cq->cq_lock);
+
+	return items_in_queue;
+}
+
+int cq_put(struct cq *cq, void *item)
+{
+	int put_pos, max_items, first, items_in_queue, item_size;
+	uint8_t *byte = (uint8_t *)item;
+
+	BUG_ON(!cq);
+
+	/* Acquire circular queue lock */
+	mutex_lock(&cq->cq_lock);
+
+	first = cq->first;
+	max_items = cq->max_items;
+	items_in_queue = cq->items_in_queue;
+	item_size = cq->item_size;
+
+	/* Check if queue is full */
+	if (items_in_queue == max_items) {
+		mutex_unlock(&cq->cq_lock);
+		return -1;
+	}
+
+	if ((first + items_in_queue) < max_items)
+		put_pos = (first + items_in_queue) * item_size;
+	else
+		put_pos = (first + items_in_queue - max_items) * item_size;
+
+	/* add element to queue */
+	memcpy(cq->items + put_pos, byte, item_size);
+
+	cq->items_in_queue++;
+
+	/* Release circular queue lock */
+	mutex_unlock(&cq->cq_lock);
+
+	return items_in_queue + 1;
+}
+
+int cq_put_1byte(struct cq *cq, uint8_t item)
+{
+	BUG_ON(!cq);
+	BUG_ON(cq->item_size != 1);
+
+	return cq_put(cq, &item);
+}
+
+int cq_put_2bytes(struct cq *cq, uint16_t item)
+{
+	BUG_ON(!cq);
+	BUG_ON(cq->item_size != 2);
+
+	return cq_put(cq, &item);
+}
+
+int cq_put_4bytes(struct cq *cq, uint32_t item)
+{
+	BUG_ON(!cq);
+	BUG_ON(cq->item_size != 4);
+
+	return cq_put(cq, &item);
+}
+
+int cq_put_8bytes(struct cq *cq, uint64_t item)
+{
+	BUG_ON(!cq);
+	BUG_ON(cq->item_size != 8);
+
+	return cq_put(cq, &item);
+}
+
+int cq_get(struct cq *cq, void *item)
+{
+	int get_pos, items_in_queue, item_size, first;
+	uint8_t *byte = (uint8_t *)item;
+
+	BUG_ON(!cq);
+	BUG_ON(!item);
+
+	/* Acquire circular queue lock */
+	mutex_lock(&cq->cq_lock);
+
+	items_in_queue = cq->items_in_queue;
+	/* Check if queue is empty */
+	if (items_in_queue == 0) {
+		/* Release circular queue lock */
+		mutex_unlock(&cq->cq_lock);
+		return -1;
+	}
+
+	first = cq->first;
+	item_size = cq->item_size;
+	get_pos = first * item_size;
+
+	/* Get item from queue */
+	memcpy(byte, cq->items + get_pos, item_size);
+	cq->items_in_queue--;
+
+	if (++first >= cq->max_items)
+		first = 0;
+	cq->first = first;
+
+	/* Release circular queue lock */
+	mutex_unlock(&cq->cq_lock);
+
+	return items_in_queue - 1;
+}
+
+int cq_get_1byte(struct cq *cq, uint8_t *item)
+{
+	BUG_ON(!cq);
+	BUG_ON(!item);
+	BUG_ON(cq->item_size != 1);
+
+	return cq_get(cq, item);
+}
+
+int cq_get_2bytes(struct cq *cq, uint16_t *item)
+{
+	BUG_ON(!cq);
+	BUG_ON(!item);
+	BUG_ON(cq->item_size != 2);
+
+	return cq_get(cq, item);
+}
+
+int cq_get_4bytes(struct cq *cq, uint32_t *item)
+{
+	BUG_ON(!cq);
+	BUG_ON(!item);
+	BUG_ON(cq->item_size != 4);
+
+	return cq_get(cq, item);
+}
+
+int cq_get_8bytes(struct cq *cq, uint64_t *item)
+{
+	BUG_ON(!cq);
+	BUG_ON(!item);
+	BUG_ON(cq->item_size != 8);
+
+	return cq_get(cq, item);
+}
+
+int cq_items_in_queue(struct cq *cq)
+{
+	int items_in_queue;
+
+	BUG_ON(!cq);
+
+	/* Acquire circular queue lock */
+	mutex_lock(&cq->cq_lock);
+
+	items_in_queue = cq->items_in_queue;
+
+	/* Release circular queue lock */
+	mutex_unlock(&cq->cq_lock);
+
+	return items_in_queue;
+}
+
+int cq_read(struct cq *cq, void *read_item, int position)
+{
+	int item_size, first, items_in_queue, bytePosition;
+	uint8_t *read_byte = (uint8_t *)read_item;
+
+	BUG_ON(!cq);
+	BUG_ON(!read_item);
+
+	/* Acquire circular queue lock */
+	mutex_lock(&cq->cq_lock);
+
+	items_in_queue = cq->items_in_queue;
+	/* Check if queue is empty and if position is valid */
+	if (items_in_queue == 0 || position > items_in_queue) {
+		mutex_unlock(&cq->cq_lock);
+		return -1;
+	}
+
+	item_size = cq->item_size;
+	first = cq->first;
+
+	/* Find byte position */
+	if (first + position - 1 > cq->max_items)
+		bytePosition =
+			(first + position - 1 - cq->max_items) * item_size;
+	else
+		bytePosition = (first + position - 1) * item_size;
+
+	/* Read from queue */
+	memcpy(read_byte, cq->items + bytePosition, item_size);
+
+	/* Release circular queue lock */
+	mutex_unlock(&cq->cq_lock);
+
+	return items_in_queue;
+}
diff --git a/drivers/staging/fsl_dpa_offload/cq.h b/drivers/staging/fsl_dpa_offload/cq.h
new file mode 100644
index 0000000..c7d8e2a
--- /dev/null
+++ b/drivers/staging/fsl_dpa_offload/cq.h
@@ -0,0 +1,141 @@
+/* Copyright 2008-2012 Freescale Semiconductor, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyright
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of Freescale Semiconductor nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ *
+ * ALTERNATIVELY, this software may be distributed under the terms of the
+ * GNU General Public License ("GPL") as published by the Free Software
+ * Foundation, either version 2 of that License or (at your option) any
+ * later version.
+ *
+ * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/*
+ * External prototypes for the circular queue object.
+ */
+
+#ifndef __CQ_H
+#define __CQ_H
+
+#include <linux/types.h>
+#include <linux/mutex.h>
+
+/* Circular queue structure */
+struct cq {
+	int max_items;		/* Size of queue */
+	int item_size;		/* Size of each item in the queue */
+	int items_in_queue;	/* Number of items in the queue */
+	int first;			/* Index of first item in queue */
+	struct mutex cq_lock;	/* Circular queue lock */
+	uint8_t items[0];		/* Holds the elements in the queue -
+					 * fake size */
+};
+
+/* Allocate and initialize a new circular queue */
+struct cq *cq_new(int max_items, int item_size);
+
+/* Delete a circular queue */
+void cq_delete(struct cq *cq);
+
+/* Empty the circular queue (clear all items) */
+int cq_flush(struct cq *cq);
+
+/*
+ * Put a new item in the circular queue
+ * Return number of items in the queue (including the added item) is successful
+ * or (-1) if failed to put the item (queue is full)
+ */
+int cq_put(struct cq *cq, void *item);
+
+/* Put a new 1-byte item in the circular queue
+ * Return number of items in the queue (including the added item) is successful
+ * or (-1) if failed to put the item (queue is full)
+ */
+int cq_put_1byte(struct cq *cq, uint8_t item);
+
+/*
+ * Put a new 2-byte item in the circular queue
+ * Return number of items in the queue (including the added item) is successful
+ * or (-1) if failed to put the item (queue is full)
+ */
+int cq_put_2bytes(struct cq *cq, uint16_t item);
+
+/*
+ * Put a new 4-byte item in the circular queue
+ * Return number of items in the queue (including the added item) is successful
+ * or (-1) if failed to put the item (queue is full)
+ */
+int cq_put_4bytes(struct cq *cq, uint32_t item);
+
+/*
+ * Put a new 8-byte item in the circular queue
+ * Return number of items in the queue (including the added item) is successful
+ * or (-1) if failed to put the item (queue is full)
+ */
+int cq_put_8bytes(struct cq *cq, uint64_t item);
+
+/* Get (and removes) an item from the circular queue
+ * Return number of items left in the queue if successful or (-1) if failed to
+ * get an item (queue is empty)
+ */
+int cq_get(struct cq *cq, void *item);
+
+/*
+ * Get and removes a 1-byte item from the circular queue
+ * Return number of items left in the queue if successful or (-1) if failed to
+ * get an item (queue is empty)
+ */
+int cq_get_1byte(struct cq *cq, uint8_t *item);
+
+/*
+ * Get and removes a 2-byte item from the circular queue
+ * Return number of items left in the queue if successful or (-1) if failed to
+ * get an item (queue is empty)
+ */
+int cq_get_2bytes(struct cq *cq, uint16_t *item);
+
+/*
+ * Get and removes a 4-byte item from the circular queue
+ * Return number of items left in the queue if successful or (-1) if failed to
+ * get an item (queue is empty)
+ */
+int cq_get_4bytes(struct cq *cq, uint32_t *item);
+
+/*
+ * Get and removes a 8-byte item from the circular queue
+ * Return number of items left in the queue if successful or (-1) if failed to
+ * get an item (queue is empty)
+ */
+int cq_get_8bytes(struct cq *cq, uint64_t *item);
+
+/* Return the number of items that are currently in the queue */
+int cq_items_in_queue(struct cq *cq);
+
+/*
+ * Read an item in the queue. The contents of the queue are not altered.
+ * Return number of items left in the queue if successful or (-1) if failed to
+ * read the item (either the queue is empty, or the requested position exceeds
+ * number of items)
+ */
+int cq_read(struct cq *cq, void *item, int position);
+
+#endif /* __CQ_H */