vnic_wq_copy.h

  1/* SPDX-License-Identifier: GPL-2.0-only */
  2/*
  3 * Copyright 2008 Cisco Systems, Inc.  All rights reserved.
  4 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
  5 */
  6#ifndef _VNIC_WQ_COPY_H_
  7#define _VNIC_WQ_COPY_H_
  8
  9#include <linux/pci.h>
 10#include "vnic_wq.h"
 11#include "fcpio.h"
 12
 13#define	VNIC_WQ_COPY_MAX 1
 14
 15struct vnic_wq_copy {
 16	unsigned int index;
 17	struct vnic_dev *vdev;
 18	struct vnic_wq_ctrl __iomem *ctrl;	/* memory-mapped */
 19	struct vnic_dev_ring ring;
 20	unsigned to_use_index;
 21	unsigned to_clean_index;
 22};
 23
 24static inline unsigned int vnic_wq_copy_desc_avail(struct vnic_wq_copy *wq)
 25{
 26	return wq->ring.desc_avail;
 27}
 28
 29static inline unsigned int vnic_wq_copy_desc_in_use(struct vnic_wq_copy *wq)
 30{
 31	return wq->ring.desc_count - 1 - wq->ring.desc_avail;
 32}
 33
 34static inline void *vnic_wq_copy_next_desc(struct vnic_wq_copy *wq)
 35{
 36	struct fcpio_host_req *desc = wq->ring.descs;
 37	return &desc[wq->to_use_index];
 38}
 39
 40static inline void vnic_wq_copy_post(struct vnic_wq_copy *wq)
 41{
 42
 43	((wq->to_use_index + 1) == wq->ring.desc_count) ?
 44		(wq->to_use_index = 0) : (wq->to_use_index++);
 45	wq->ring.desc_avail--;
 46
 47	/* Adding write memory barrier prevents compiler and/or CPU
 48	 * reordering, thus avoiding descriptor posting before
 49	 * descriptor is initialized. Otherwise, hardware can read
 50	 * stale descriptor fields.
 51	 */
 52	wmb();
 53
 54	iowrite32(wq->to_use_index, &wq->ctrl->posted_index);
 55}
 56
 57static inline void vnic_wq_copy_desc_process(struct vnic_wq_copy *wq, u16 index)
 58{
 59	unsigned int cnt;
 60
 61	if (wq->to_clean_index <= index)
 62		cnt = (index - wq->to_clean_index) + 1;
 63	else
 64		cnt = wq->ring.desc_count - wq->to_clean_index + index + 1;
 65
 66	wq->to_clean_index = ((index + 1) % wq->ring.desc_count);
 67	wq->ring.desc_avail += cnt;
 68
 69}
 70
 71static inline void vnic_wq_copy_service(struct vnic_wq_copy *wq,
 72	u16 completed_index,
 73	void (*q_service)(struct vnic_wq_copy *wq,
 74	struct fcpio_host_req *wq_desc))
 75{
 76	struct fcpio_host_req *wq_desc = wq->ring.descs;
 77	unsigned int curr_index;
 78
 79	while (1) {
 80
 81		if (q_service)
 82			(*q_service)(wq, &wq_desc[wq->to_clean_index]);
 83
 84		wq->ring.desc_avail++;
 85
 86		curr_index = wq->to_clean_index;
 87
 88		/* increment the to-clean index so that we start
 89		 * with an unprocessed index next time we enter the loop
 90		 */
 91		((wq->to_clean_index + 1) == wq->ring.desc_count) ?
 92			(wq->to_clean_index = 0) : (wq->to_clean_index++);
 93
 94		if (curr_index == completed_index)
 95			break;
 96
 97		/* we have cleaned all the entries */
 98		if ((completed_index == (u16)-1) &&
 99		    (wq->to_clean_index == wq->to_use_index))
100			break;
101	}
102}
103
104void vnic_wq_copy_enable(struct vnic_wq_copy *wq);
105int vnic_wq_copy_disable(struct vnic_wq_copy *wq);
106void vnic_wq_copy_free(struct vnic_wq_copy *wq);
107int vnic_wq_copy_alloc(struct vnic_dev *vdev, struct vnic_wq_copy *wq,
108	unsigned int index, unsigned int desc_count, unsigned int desc_size);
109void vnic_wq_copy_init(struct vnic_wq_copy *wq, unsigned int cq_index,
110	unsigned int error_interrupt_enable,
111	unsigned int error_interrupt_offset);
112void vnic_wq_copy_clean(struct vnic_wq_copy *wq,
113	void (*q_clean)(struct vnic_wq_copy *wq,
114	struct fcpio_host_req *wq_desc));
115
116#endif /* _VNIC_WQ_COPY_H_ */