1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
4 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
5 */
6
7#include <linux/kernel.h>
8#include <linux/errno.h>
9#include <linux/types.h>
10#include <linux/pci.h>
11#include <linux/delay.h>
12#include <linux/slab.h>
13
14#include "vnic_dev.h"
15#include "vnic_rq.h"
16#include "enic.h"
17
18static int vnic_rq_alloc_bufs(struct vnic_rq *rq)
19{
20	struct vnic_rq_buf *buf;
21	unsigned int i, j, count = rq->ring.desc_count;
22	unsigned int blks = VNIC_RQ_BUF_BLKS_NEEDED(count);
23
24	for (i = 0; i < blks; i++) {
25		rq->bufs[i] = kzalloc(VNIC_RQ_BUF_BLK_SZ(count), GFP_KERNEL);
26		if (!rq->bufs[i])
27			return -ENOMEM;
28	}
29
30	for (i = 0; i < blks; i++) {
31		buf = rq->bufs[i];
32		for (j = 0; j < VNIC_RQ_BUF_BLK_ENTRIES(count); j++) {
33			buf->index = i * VNIC_RQ_BUF_BLK_ENTRIES(count) + j;
34			buf->desc = (u8 *)rq->ring.descs +
35				rq->ring.desc_size * buf->index;
36			if (buf->index + 1 == count) {
37				buf->next = rq->bufs[0];
38				break;
39			} else if (j + 1 == VNIC_RQ_BUF_BLK_ENTRIES(count)) {
40				buf->next = rq->bufs[i + 1];
41			} else {
42				buf->next = buf + 1;
43				buf++;
44			}
45		}
46	}
47
48	rq->to_use = rq->to_clean = rq->bufs[0];
49
50	return 0;
51}
52
53void vnic_rq_free(struct vnic_rq *rq)
54{
55	struct vnic_dev *vdev;
56	unsigned int i;
57
58	vdev = rq->vdev;
59
60	vnic_dev_free_desc_ring(vdev, &rq->ring);
61
62	for (i = 0; i < VNIC_RQ_BUF_BLKS_MAX; i++) {
63		if (rq->bufs[i]) {
64			kfree(rq->bufs[i]);
65			rq->bufs[i] = NULL;
66		}
67	}
68
69	rq->ctrl = NULL;
70}
71
72int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
73	unsigned int desc_count, unsigned int desc_size)
74{
75	int err;
76
77	rq->index = index;
78	rq->vdev = vdev;
79
80	rq->ctrl = vnic_dev_get_res(vdev, RES_TYPE_RQ, index);
81	if (!rq->ctrl) {
82		vdev_err(vdev, "Failed to hook RQ[%d] resource\n", index);
83		return -EINVAL;
84	}
85
86	vnic_rq_disable(rq);
87
88	err = vnic_dev_alloc_desc_ring(vdev, &rq->ring, desc_count, desc_size);
89	if (err)
90		return err;
91
92	err = vnic_rq_alloc_bufs(rq);
93	if (err) {
94		vnic_rq_free(rq);
95		return err;
96	}
97
98	return 0;
99}
100
101static void vnic_rq_init_start(struct vnic_rq *rq, unsigned int cq_index,
102	unsigned int fetch_index, unsigned int posted_index,
103	unsigned int error_interrupt_enable,
104	unsigned int error_interrupt_offset)
105{
106	u64 paddr;
107	unsigned int count = rq->ring.desc_count;
108
109	paddr = (u64)rq->ring.base_addr | VNIC_PADDR_TARGET;
110	writeq(paddr, &rq->ctrl->ring_base);
111	iowrite32(count, &rq->ctrl->ring_size);
112	iowrite32(cq_index, &rq->ctrl->cq_index);
113	iowrite32(error_interrupt_enable, &rq->ctrl->error_interrupt_enable);
114	iowrite32(error_interrupt_offset, &rq->ctrl->error_interrupt_offset);
115	iowrite32(0, &rq->ctrl->dropped_packet_count);
116	iowrite32(0, &rq->ctrl->error_status);
117	iowrite32(fetch_index, &rq->ctrl->fetch_index);
118	iowrite32(posted_index, &rq->ctrl->posted_index);
119
120	rq->to_use = rq->to_clean =
121		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
122			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
123}
124
125void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
126	unsigned int error_interrupt_enable,
127	unsigned int error_interrupt_offset)
128{
129	vnic_rq_init_start(rq, cq_index, 0, 0, error_interrupt_enable,
130			   error_interrupt_offset);
131}
132
133unsigned int vnic_rq_error_status(struct vnic_rq *rq)
134{
135	return ioread32(&rq->ctrl->error_status);
136}
137
138void vnic_rq_enable(struct vnic_rq *rq)
139{
140	iowrite32(1, &rq->ctrl->enable);
141}
142
143int vnic_rq_disable(struct vnic_rq *rq)
144{
145	unsigned int wait;
146	struct vnic_dev *vdev = rq->vdev;
147	int i;
148
149	/* Due to a race condition with clearing RQ "mini-cache" in hw, we need
150	 * to disable the RQ twice to guarantee that stale descriptors are not
151	 * used when this RQ is re-enabled.
152	 */
153	for (i = 0; i < 2; i++) {
154		iowrite32(0, &rq->ctrl->enable);
155
156		/* Wait for HW to ACK disable request */
157		for (wait = 20000; wait > 0; wait--)
158			if (!ioread32(&rq->ctrl->running))
159				break;
160		if (!wait) {
161			vdev_neterr(vdev, "Failed to disable RQ[%d]\n",
162				    rq->index);
163
164			return -ETIMEDOUT;
165		}
166	}
167
168	return 0;
169}
170
171void vnic_rq_clean(struct vnic_rq *rq,
172	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf))
173{
174	struct vnic_rq_buf *buf;
175	u32 fetch_index;
176	unsigned int count = rq->ring.desc_count;
177	int i;
178
179	buf = rq->to_clean;
180
181	for (i = 0; i < rq->ring.desc_count; i++) {
182		(*buf_clean)(rq, buf);
183		buf = buf->next;
184	}
185	rq->ring.desc_avail = rq->ring.desc_count - 1;
186
187	/* Use current fetch_index as the ring starting point */
188	fetch_index = ioread32(&rq->ctrl->fetch_index);
189
190	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
191		/* Hardware surprise removal: reset fetch_index */
192		fetch_index = 0;
193	}
194	rq->to_use = rq->to_clean =
195		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
196			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
197	iowrite32(fetch_index, &rq->ctrl->posted_index);
198
199	/* Anytime we write fetch_index, we need to re-write 0 to rq->enable
200	 * to re-sync internal VIC state.
201	 */
202	iowrite32(0, &rq->ctrl->enable);
203
204	vnic_dev_clear_desc_ring(&rq->ring);
205}
206