path: root/drivers/net/wireless/rt2x00/rt2x00queue.c

/*
	Copyright (C) 2010 Willow Garage <http://www.willowgarage.com>
	Copyright (C) 2004 - 2010 Ivo van Doorn <IvDoorn@gmail.com>
	Copyright (C) 2004 - 2009 Gertjan van Wingerde <gwingerde@gmail.com>
	<http://rt2x00.serialmonkey.com>

	This program is free software; you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation; either version 2 of the License, or
	(at your option) any later version.

	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.

	You should have received a copy of the GNU General Public License
	along with this program; if not, write to the
	Free Software Foundation, Inc.,
	59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 */

/*
	Module: rt2x00lib
	Abstract: rt2x00 queue specific routines.
 */

#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/dma-mapping.h>

#include "rt2x00.h"
#include "rt2x00lib.h"

struct sk_buff *rt2x00queue_alloc_rxskb(struct queue_entry *entry)
{
	struct rt2x00_dev *rt2x00dev = entry->queue->rt2x00dev;
	struct sk_buff *skb;
	struct skb_frame_desc *skbdesc;
	unsigned int frame_size;
	unsigned int head_size = 0;
	unsigned int tail_size = 0;

	/*
	 * The frame size includes descriptor size, because the
	 * hardware directly receive the frame into the skbuffer.
	 */
	frame_size = entry->queue->data_size + entry->queue->desc_size;

	/*
	 * The payload should be aligned to a 4-byte boundary,
	 * this means we need at least 3 bytes for moving the frame
	 * into the correct offset.
	 */
	head_size = 4;

	/*
	 * For IV/EIV/ICV assembly we must make sure there is
	 * at least 8 bytes bytes available in headroom for IV/EIV
	 * and 8 bytes for ICV data as tailroon.
	 */
	if (test_bit(CONFIG_SUPPORT_HW_CRYPTO, &rt2x00dev->flags)) {
		head_size += 8;
		tail_size += 8;
	}

	/*
	 * Allocate skbuffer.
	 */
	skb = dev_alloc_skb(frame_size + head_size + tail_size);
	if (!skb)
		return NULL;

	/*
	 * Make sure we not have a frame with the requested bytes
	 * available in the head and tail.
	 */
	skb_reserve(skb, head_size);
	skb_put(skb, frame_size);

	/*
	 * Populate skbdesc.
	 */
	skbdesc = get_skb_frame_desc(skb);
	memset(skbdesc, 0, sizeof(*skbdesc));
	skbdesc->entry = entry;

	if (test_bit(DRIVER_REQUIRE_DMA, &rt2x00dev->flags)) {
		skbdesc->skb_dma = dma_map_single(rt2x00dev->dev,
						  skb->data,
						  skb->len,
						  DMA_FROM_DEVICE);
		skbdesc->flags |= SKBDESC_DMA_MAPPED_RX;
	}

	return skb;
}

void rt2x00queue_map_txskb(struct queue_entry *entry)
{
	struct device *dev = entry->queue->rt2x00dev->dev;
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);

	skbdesc->skb_dma =
	    dma_map_single(dev, entry->skb->data, entry->skb->len, DMA_TO_DEVICE);
	skbdesc->flags |= SKBDESC_DMA_MAPPED_TX;
}
EXPORT_SYMBOL_GPL(rt2x00queue_map_txskb);

void rt2x00queue_unmap_skb(struct queue_entry *entry)
{
	struct device *dev = entry->queue->rt2x00dev->dev;
	struct skb_frame_desc *skbdesc = get_skb_frame_desc(entry->skb);

	if (skbdesc->flags & SKBDESC_DMA_MAPPED_RX) {
		dma_unmap_single(dev, skbdesc->skb_dma, entry->skb->len,
				 DMA_FROM_DEVICE);
		skbdesc->flags &= ~SKBDESC_DMA_MAPPED_RX;
	} else if (skbdesc->flags