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#ifndef _VNIC_RQ_H_
8#define _VNIC_RQ_H_
9
10#include <linux/pci.h>
11#include <linux/netdevice.h>
12
13#include "vnic_dev.h"
14#include "vnic_cq.h"
15
16/* Receive queue control */
17struct vnic_rq_ctrl {
18 u64 ring_base; /* 0x00 */
19 u32 ring_size; /* 0x08 */
20 u32 pad0;
21 u32 posted_index; /* 0x10 */
22 u32 pad1;
23 u32 cq_index; /* 0x18 */
24 u32 pad2;
25 u32 enable; /* 0x20 */
26 u32 pad3;
27 u32 running; /* 0x28 */
28 u32 pad4;
29 u32 fetch_index; /* 0x30 */
30 u32 pad5;
31 u32 error_interrupt_enable; /* 0x38 */
32 u32 pad6;
33 u32 error_interrupt_offset; /* 0x40 */
34 u32 pad7;
35 u32 error_status; /* 0x48 */
36 u32 pad8;
37 u32 dropped_packet_count; /* 0x50 */
38 u32 pad9;
39 u32 dropped_packet_count_rc; /* 0x58 */
40 u32 pad10;
41};
42
43/* Break the vnic_rq_buf allocations into blocks of 32/64 entries */
44#define VNIC_RQ_BUF_MIN_BLK_ENTRIES 32
45#define VNIC_RQ_BUF_DFLT_BLK_ENTRIES 64
46#define VNIC_RQ_BUF_BLK_ENTRIES(entries) \
47 ((unsigned int)((entries < VNIC_RQ_BUF_DFLT_BLK_ENTRIES) ? \
48 VNIC_RQ_BUF_MIN_BLK_ENTRIES : VNIC_RQ_BUF_DFLT_BLK_ENTRIES))
49#define VNIC_RQ_BUF_BLK_SZ(entries) \
50 (VNIC_RQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_rq_buf))
51#define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
52 DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES(entries))
53#define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
54
55struct vnic_rq_buf {
56 struct vnic_rq_buf *next;
57 dma_addr_t dma_addr;
58 void *os_buf;
59 unsigned int os_buf_index;
60 unsigned int len;
61 unsigned int index;
62 void *desc;
63 uint64_t wr_id;
64};
65
66enum enic_poll_state {
67 ENIC_POLL_STATE_IDLE,
68 ENIC_POLL_STATE_NAPI,
69 ENIC_POLL_STATE_POLL
70};
71
72struct vnic_rq {
73 unsigned int index;
74 struct vnic_dev *vdev;
75 struct vnic_rq_ctrl __iomem *ctrl; /* memory-mapped */
76 struct vnic_dev_ring ring;
77 struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
78 struct vnic_rq_buf *to_use;
79 struct vnic_rq_buf *to_clean;
80 void *os_buf_head;
81 unsigned int pkts_outstanding;
82};
83
84static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
85{
86 /* how many does SW own? */
87 return rq->ring.desc_avail;
88}
89
90static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
91{
92 /* how many does HW own? */
93 return rq->ring.desc_count - rq->ring.desc_avail - 1;
94}
95
96static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
97{
98 return rq->to_use->desc;
99}
100
101static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
102{
103 return rq->to_use->index;
104}
105
106static inline void vnic_rq_post(struct vnic_rq *rq,
107 void *os_buf, unsigned int os_buf_index,
108 dma_addr_t dma_addr, unsigned int len,
109 uint64_t wrid)
110{
111 struct vnic_rq_buf *buf = rq->to_use;
112
113 buf->os_buf = os_buf;
114 buf->os_buf_index = os_buf_index;
115 buf->dma_addr = dma_addr;
116 buf->len = len;
117 buf->wr_id = wrid;
118
119 buf = buf->next;
120 rq->to_use = buf;
121 rq->ring.desc_avail--;
122
123 /* Move the posted_index every nth descriptor
124 */
125
126#ifndef VNIC_RQ_RETURN_RATE
127#define VNIC_RQ_RETURN_RATE 0xf /* keep 2^n - 1 */
128#endif
129
130 if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
131 /* Adding write memory barrier prevents compiler and/or CPU
132 * reordering, thus avoiding descriptor posting before
133 * descriptor is initialized. Otherwise, hardware can read
134 * stale descriptor fields.
135 */
136 wmb();
137 iowrite32(buf->index, &rq->ctrl->posted_index);
138 }
139}
140
141static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
142{
143 rq->ring.desc_avail += count;
144}
145
146enum desc_return_options {
147 VNIC_RQ_RETURN_DESC,
148 VNIC_RQ_DEFER_RETURN_DESC,
149};
150
151static inline void vnic_rq_service(struct vnic_rq *rq,
152 struct cq_desc *cq_desc, u16 completed_index,
153 int desc_return, void (*buf_service)(struct vnic_rq *rq,
154 struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
155 int skipped, void *opaque), void *opaque)
156{
157 struct vnic_rq_buf *buf;
158 int skipped;
159
160 buf = rq->to_clean;
161 while (1) {
162
163 skipped = (buf->index != completed_index);
164
165 (*buf_service)(rq, cq_desc, buf, skipped, opaque);
166
167 if (desc_return == VNIC_RQ_RETURN_DESC)
168 rq->ring.desc_avail++;
169
170 rq->to_clean = buf->next;
171
172 if (!skipped)
173 break;
174
175 buf = rq->to_clean;
176 }
177}
178
179static inline int vnic_rq_fill(struct vnic_rq *rq,
180 int (*buf_fill)(struct vnic_rq *rq))
181{
182 int err;
183
184 while (vnic_rq_desc_avail(rq) > 0) {
185
186 err = (*buf_fill)(rq);
187 if (err)
188 return err;
189 }
190
191 return 0;
192}
193
194void vnic_rq_free(struct vnic_rq *rq);
195int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
196 unsigned int desc_count, unsigned int desc_size);
197void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
198 unsigned int error_interrupt_enable,
199 unsigned int error_interrupt_offset);
200unsigned int vnic_rq_error_status(struct vnic_rq *rq);
201void vnic_rq_enable(struct vnic_rq *rq);
202int vnic_rq_disable(struct vnic_rq *rq);
203void vnic_rq_clean(struct vnic_rq *rq,
204 void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
205
206#endif /* _VNIC_RQ_H_ */
207

source code of linux/drivers/net/ethernet/cisco/enic/vnic_rq.h