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/drivers/scsi/fnic/vnic_wq_copy.h

http://github.com/mirrors/linux
C Header | 128 lines | 78 code | 24 blank | 26 comment | 10 complexity | aa266d4868617d23996890fbf9d7e2f2 MD5 | raw file
  1/*
  2 * Copyright 2008 Cisco Systems, Inc.  All rights reserved.
  3 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
  4 *
  5 * This program is free software; you may redistribute it and/or modify
  6 * it under the terms of the GNU General Public License as published by
  7 * the Free Software Foundation; version 2 of the License.
  8 *
  9 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 10 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 11 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 12 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 13 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 14 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 15 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 16 * SOFTWARE.
 17 */
 18#ifndef _VNIC_WQ_COPY_H_
 19#define _VNIC_WQ_COPY_H_
 20
 21#include <linux/pci.h>
 22#include "vnic_wq.h"
 23#include "fcpio.h"
 24
 25#define	VNIC_WQ_COPY_MAX 1
 26
 27struct vnic_wq_copy {
 28	unsigned int index;
 29	struct vnic_dev *vdev;
 30	struct vnic_wq_ctrl __iomem *ctrl;	/* memory-mapped */
 31	struct vnic_dev_ring ring;
 32	unsigned to_use_index;
 33	unsigned to_clean_index;
 34};
 35
 36static inline unsigned int vnic_wq_copy_desc_avail(struct vnic_wq_copy *wq)
 37{
 38	return wq->ring.desc_avail;
 39}
 40
 41static inline unsigned int vnic_wq_copy_desc_in_use(struct vnic_wq_copy *wq)
 42{
 43	return wq->ring.desc_count - 1 - wq->ring.desc_avail;
 44}
 45
 46static inline void *vnic_wq_copy_next_desc(struct vnic_wq_copy *wq)
 47{
 48	struct fcpio_host_req *desc = wq->ring.descs;
 49	return &desc[wq->to_use_index];
 50}
 51
 52static inline void vnic_wq_copy_post(struct vnic_wq_copy *wq)
 53{
 54
 55	((wq->to_use_index + 1) == wq->ring.desc_count) ?
 56		(wq->to_use_index = 0) : (wq->to_use_index++);
 57	wq->ring.desc_avail--;
 58
 59	/* Adding write memory barrier prevents compiler and/or CPU
 60	 * reordering, thus avoiding descriptor posting before
 61	 * descriptor is initialized. Otherwise, hardware can read
 62	 * stale descriptor fields.
 63	 */
 64	wmb();
 65
 66	iowrite32(wq->to_use_index, &wq->ctrl->posted_index);
 67}
 68
 69static inline void vnic_wq_copy_desc_process(struct vnic_wq_copy *wq, u16 index)
 70{
 71	unsigned int cnt;
 72
 73	if (wq->to_clean_index <= index)
 74		cnt = (index - wq->to_clean_index) + 1;
 75	else
 76		cnt = wq->ring.desc_count - wq->to_clean_index + index + 1;
 77
 78	wq->to_clean_index = ((index + 1) % wq->ring.desc_count);
 79	wq->ring.desc_avail += cnt;
 80
 81}
 82
 83static inline void vnic_wq_copy_service(struct vnic_wq_copy *wq,
 84	u16 completed_index,
 85	void (*q_service)(struct vnic_wq_copy *wq,
 86	struct fcpio_host_req *wq_desc))
 87{
 88	struct fcpio_host_req *wq_desc = wq->ring.descs;
 89	unsigned int curr_index;
 90
 91	while (1) {
 92
 93		if (q_service)
 94			(*q_service)(wq, &wq_desc[wq->to_clean_index]);
 95
 96		wq->ring.desc_avail++;
 97
 98		curr_index = wq->to_clean_index;
 99
100		/* increment the to-clean index so that we start
101		 * with an unprocessed index next time we enter the loop
102		 */
103		((wq->to_clean_index + 1) == wq->ring.desc_count) ?
104			(wq->to_clean_index = 0) : (wq->to_clean_index++);
105
106		if (curr_index == completed_index)
107			break;
108
109		/* we have cleaned all the entries */
110		if ((completed_index == (u16)-1) &&
111		    (wq->to_clean_index == wq->to_use_index))
112			break;
113	}
114}
115
116void vnic_wq_copy_enable(struct vnic_wq_copy *wq);
117int vnic_wq_copy_disable(struct vnic_wq_copy *wq);
118void vnic_wq_copy_free(struct vnic_wq_copy *wq);
119int vnic_wq_copy_alloc(struct vnic_dev *vdev, struct vnic_wq_copy *wq,
120	unsigned int index, unsigned int desc_count, unsigned int desc_size);
121void vnic_wq_copy_init(struct vnic_wq_copy *wq, unsigned int cq_index,
122	unsigned int error_interrupt_enable,
123	unsigned int error_interrupt_offset);
124void vnic_wq_copy_clean(struct vnic_wq_copy *wq,
125	void (*q_clean)(struct vnic_wq_copy *wq,
126	struct fcpio_host_req *wq_desc));
127
128#endif /* _VNIC_WQ_COPY_H_ */