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 
18 static 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 
53 void 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 
72 int 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 
101 static 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 
125 void 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 
133 unsigned int vnic_rq_error_status(struct vnic_rq *rq)
134 {
135 	return ioread32(&rq->ctrl->error_status);
136 }
137 
138 void vnic_rq_enable(struct vnic_rq *rq)
139 {
140 	iowrite32(1, &rq->ctrl->enable);
141 }
142 
143 int 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 
171 void 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