1/*
  2 * Copyright 2008-2010 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 */
 19
 20#ifndef _VNIC_WQ_H_
 21#define _VNIC_WQ_H_
 22
 23#include <linux/pci.h>
 24
 25#include "vnic_dev.h"
 26#include "vnic_cq.h"
 27
 28/* Work queue control */
 29struct vnic_wq_ctrl {
 30	u64 ring_base;			/* 0x00 */
 31	u32 ring_size;			/* 0x08 */
 32	u32 pad0;
 33	u32 posted_index;		/* 0x10 */
 34	u32 pad1;
 35	u32 cq_index;			/* 0x18 */
 36	u32 pad2;
 37	u32 enable;			/* 0x20 */
 38	u32 pad3;
 39	u32 running;			/* 0x28 */
 40	u32 pad4;
 41	u32 fetch_index;		/* 0x30 */
 42	u32 pad5;
 43	u32 dca_value;			/* 0x38 */
 44	u32 pad6;
 45	u32 error_interrupt_enable;	/* 0x40 */
 46	u32 pad7;
 47	u32 error_interrupt_offset;	/* 0x48 */
 48	u32 pad8;
 49	u32 error_status;		/* 0x50 */
 50	u32 pad9;
 51};
 52
 53struct vnic_wq_buf {
 54	struct vnic_wq_buf *next;
 55	dma_addr_t dma_addr;
 56	void *os_buf;
 57	unsigned int len;
 58	unsigned int index;
 59	int sop;
 60	void *desc;
 61};
 62
 63/* Break the vnic_wq_buf allocations into blocks of 32/64 entries */
 64#define VNIC_WQ_BUF_MIN_BLK_ENTRIES 32
 65#define VNIC_WQ_BUF_DFLT_BLK_ENTRIES 64
 66#define VNIC_WQ_BUF_BLK_ENTRIES(entries) \
 67	((unsigned int)((entries < VNIC_WQ_BUF_DFLT_BLK_ENTRIES) ? \
 68	VNIC_WQ_BUF_MIN_BLK_ENTRIES : VNIC_WQ_BUF_DFLT_BLK_ENTRIES))
 69#define VNIC_WQ_BUF_BLK_SZ(entries) \
 70	(VNIC_WQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_wq_buf))
 71#define VNIC_WQ_BUF_BLKS_NEEDED(entries) \
 72	DIV_ROUND_UP(entries, VNIC_WQ_BUF_BLK_ENTRIES(entries))
 73#define VNIC_WQ_BUF_BLKS_MAX VNIC_WQ_BUF_BLKS_NEEDED(4096)
 74
 75struct vnic_wq {
 76	unsigned int index;
 77	struct vnic_dev *vdev;
 78	struct vnic_wq_ctrl __iomem *ctrl;              /* memory-mapped */
 79	struct vnic_dev_ring ring;
 80	struct vnic_wq_buf *bufs[VNIC_WQ_BUF_BLKS_MAX];
 81	struct vnic_wq_buf *to_use;
 82	struct vnic_wq_buf *to_clean;
 83	unsigned int pkts_outstanding;
 84};
 85
 86static inline unsigned int vnic_wq_desc_avail(struct vnic_wq *wq)
 87{
 88	/* how many does SW own? */
 89	return wq->ring.desc_avail;
 90}
 91
 92static inline unsigned int vnic_wq_desc_used(struct vnic_wq *wq)
 93{
 94	/* how many does HW own? */
 95	return wq->ring.desc_count - wq->ring.desc_avail - 1;
 96}
 97
 98static inline void *vnic_wq_next_desc(struct vnic_wq *wq)
 99{
100	return wq->to_use->desc;
101}
102
103static inline void vnic_wq_post(struct vnic_wq *wq,
104	void *os_buf, dma_addr_t dma_addr,
105	unsigned int len, int sop, int eop)
106{
107	struct vnic_wq_buf *buf = wq->to_use;
108
109	buf->sop = sop;
110	buf->os_buf = eop ? os_buf : NULL;
111	buf->dma_addr = dma_addr;
112	buf->len = len;
113
114	buf = buf->next;
115	if (eop) {
116		/* Adding write memory barrier prevents compiler and/or CPU
117		 * reordering, thus avoiding descriptor posting before
118		 * descriptor is initialized. Otherwise, hardware can read
119		 * stale descriptor fields.
120		 */
121		wmb();
122		iowrite32(buf->index, &wq->ctrl->posted_index);
123	}
124	wq->to_use = buf;
125
126	wq->ring.desc_avail--;
127}
128
129static inline void vnic_wq_service(struct vnic_wq *wq,
130	struct cq_desc *cq_desc, u16 completed_index,
131	void (*buf_service)(struct vnic_wq *wq,
132	struct cq_desc *cq_desc, struct vnic_wq_buf *buf, void *opaque),
133	void *opaque)
134{
135	struct vnic_wq_buf *buf;
136
137	buf = wq->to_clean;
138	while (1) {
139
140		(*buf_service)(wq, cq_desc, buf, opaque);
141
142		wq->ring.desc_avail++;
143
144		wq->to_clean = buf->next;
145
146		if (buf->index == completed_index)
147			break;
148
149		buf = wq->to_clean;
150	}
151}
152
153void vnic_wq_free(struct vnic_wq *wq);
154int vnic_wq_alloc(struct vnic_dev *vdev, struct vnic_wq *wq, unsigned int index,
155	unsigned int desc_count, unsigned int desc_size);
156void vnic_wq_init(struct vnic_wq *wq, unsigned int cq_index,
157	unsigned int error_interrupt_enable,
158	unsigned int error_interrupt_offset);
159unsigned int vnic_wq_error_status(struct vnic_wq *wq);
160void vnic_wq_enable(struct vnic_wq *wq);
161int vnic_wq_disable(struct vnic_wq *wq);
162void vnic_wq_clean(struct vnic_wq *wq,
163	void (*buf_clean)(struct vnic_wq *wq, struct vnic_wq_buf *buf));
164
165#endif /* _VNIC_WQ_H_ */