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#include <linux/kernel.h>
 21#include <linux/errno.h>
 22#include <linux/types.h>
 23#include <linux/pci.h>
 24#include <linux/delay.h>
 25#include <linux/slab.h>
 26
 27#include "vnic_dev.h"
 28#include "vnic_rq.h"
 29
 30static int vnic_rq_alloc_bufs(struct vnic_rq *rq)
 31{
 32	struct vnic_rq_buf *buf;
 33	struct vnic_dev *vdev;
 34	unsigned int i, j, count = rq->ring.desc_count;
 35	unsigned int blks = VNIC_RQ_BUF_BLKS_NEEDED(count);
 36
 37	vdev = rq->vdev;
 38
 39	for (i = 0; i < blks; i++) {
 40		rq->bufs[i] = kzalloc(VNIC_RQ_BUF_BLK_SZ(count), GFP_ATOMIC);
 41		if (!rq->bufs[i]) {
 42			pr_err("Failed to alloc rq_bufs\n");
 43			return -ENOMEM;
 44		}
 45	}
 46
 47	for (i = 0; i < blks; i++) {
 48		buf = rq->bufs[i];
 49		for (j = 0; j < VNIC_RQ_BUF_BLK_ENTRIES(count); j++) {
 50			buf->index = i * VNIC_RQ_BUF_BLK_ENTRIES(count) + j;
 51			buf->desc = (u8 *)rq->ring.descs +
 52				rq->ring.desc_size * buf->index;
 53			if (buf->index + 1 == count) {
 54				buf->next = rq->bufs[0];
 55				break;
 56			} else if (j + 1 == VNIC_RQ_BUF_BLK_ENTRIES(count)) {
 57				buf->next = rq->bufs[i + 1];
 58			} else {
 59				buf->next = buf + 1;
 60				buf++;
 61			}
 62		}
 63	}
 64
 65	rq->to_use = rq->to_clean = rq->bufs[0];
 66
 67	return 0;
 68}
 69
 70void vnic_rq_free(struct vnic_rq *rq)
 71{
 72	struct vnic_dev *vdev;
 73	unsigned int i;
 74
 75	vdev = rq->vdev;
 76
 77	vnic_dev_free_desc_ring(vdev, &rq->ring);
 78
 79	for (i = 0; i < VNIC_RQ_BUF_BLKS_MAX; i++) {
 80		if (rq->bufs[i]) {
 81			kfree(rq->bufs[i]);
 82			rq->bufs[i] = NULL;
 83		}
 84	}
 85
 86	rq->ctrl = NULL;
 87}
 88
 89int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
 90	unsigned int desc_count, unsigned int desc_size)
 91{
 92	int err;
 93
 94	rq->index = index;
 95	rq->vdev = vdev;
 96
 97	rq->ctrl = vnic_dev_get_res(vdev, RES_TYPE_RQ, index);
 98	if (!rq->ctrl) {
 99		pr_err("Failed to hook RQ[%d] resource\n", index);
100		return -EINVAL;
101	}
102
103	vnic_rq_disable(rq);
104
105	err = vnic_dev_alloc_desc_ring(vdev, &rq->ring, desc_count, desc_size);
106	if (err)
107		return err;
108
109	err = vnic_rq_alloc_bufs(rq);
110	if (err) {
111		vnic_rq_free(rq);
112		return err;
113	}
114
115	return 0;
116}
117
118static void vnic_rq_init_start(struct vnic_rq *rq, unsigned int cq_index,
119	unsigned int fetch_index, unsigned int posted_index,
120	unsigned int error_interrupt_enable,
121	unsigned int error_interrupt_offset)
122{
123	u64 paddr;
124	unsigned int count = rq->ring.desc_count;
125
126	paddr = (u64)rq->ring.base_addr | VNIC_PADDR_TARGET;
127	writeq(paddr, &rq->ctrl->ring_base);
128	iowrite32(count, &rq->ctrl->ring_size);
129	iowrite32(cq_index, &rq->ctrl->cq_index);
130	iowrite32(error_interrupt_enable, &rq->ctrl->error_interrupt_enable);
131	iowrite32(error_interrupt_offset, &rq->ctrl->error_interrupt_offset);
132	iowrite32(0, &rq->ctrl->dropped_packet_count);
133	iowrite32(0, &rq->ctrl->error_status);
134	iowrite32(fetch_index, &rq->ctrl->fetch_index);
135	iowrite32(posted_index, &rq->ctrl->posted_index);
136
137	rq->to_use = rq->to_clean =
138		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
139			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
140}
141
142void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
143	unsigned int error_interrupt_enable,
144	unsigned int error_interrupt_offset)
145{
146	u32 fetch_index;
147
148	/* Use current fetch_index as the ring starting point */
149	fetch_index = ioread32(&rq->ctrl->fetch_index);
150
151	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
152		/* Hardware surprise removal: reset fetch_index */
153		fetch_index = 0;
154	}
155
156	vnic_rq_init_start(rq, cq_index,
157		fetch_index, fetch_index,
158		error_interrupt_enable,
159		error_interrupt_offset);
160}
161
162unsigned int vnic_rq_error_status(struct vnic_rq *rq)
163{
164	return ioread32(&rq->ctrl->error_status);
165}
166
167void vnic_rq_enable(struct vnic_rq *rq)
168{
169	iowrite32(1, &rq->ctrl->enable);
170}
171
172int vnic_rq_disable(struct vnic_rq *rq)
173{
174	unsigned int wait;
175
176	iowrite32(0, &rq->ctrl->enable);
177
178	/* Wait for HW to ACK disable request */
179	for (wait = 0; wait < 1000; wait++) {
180		if (!(ioread32(&rq->ctrl->running)))
181			return 0;
182		udelay(10);
183	}
184
185	pr_err("Failed to disable RQ[%d]\n", rq->index);
186
187	return -ETIMEDOUT;
188}
189
190void vnic_rq_clean(struct vnic_rq *rq,
191	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf))
192{
193	struct vnic_rq_buf *buf;
194	u32 fetch_index;
195	unsigned int count = rq->ring.desc_count;
196
197	buf = rq->to_clean;
198
199	while (vnic_rq_desc_used(rq) > 0) {
200
201		(*buf_clean)(rq, buf);
202
203		buf = rq->to_clean = buf->next;
204		rq->ring.desc_avail++;
205	}
206
207	/* Use current fetch_index as the ring starting point */
208	fetch_index = ioread32(&rq->ctrl->fetch_index);
209
210	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
211		/* Hardware surprise removal: reset fetch_index */
212		fetch_index = 0;
213	}
214	rq->to_use = rq->to_clean =
215		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
216			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
217	iowrite32(fetch_index, &rq->ctrl->posted_index);
218
219	vnic_dev_clear_desc_ring(&rq->ring);
220}
221