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