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vnic_rq.h
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1 /*
2  * Copyright 2008 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 #ifndef _VNIC_RQ_H_
19 #define _VNIC_RQ_H_
20 
21 #include <linux/pci.h>
22 #include "vnic_dev.h"
23 #include "vnic_cq.h"
24 
25 /*
26  * These defines avoid symbol clash between fnic and enic (Cisco 10G Eth
27  * Driver) when both are built with CONFIG options =y
28  */
29 #define vnic_rq_desc_avail fnic_rq_desc_avail
30 #define vnic_rq_desc_used fnic_rq_desc_used
31 #define vnic_rq_next_desc fnic_rq_next_desc
32 #define vnic_rq_next_index fnic_rq_next_index
33 #define vnic_rq_next_buf_index fnic_rq_next_buf_index
34 #define vnic_rq_post fnic_rq_post
35 #define vnic_rq_posting_soon fnic_rq_posting_soon
36 #define vnic_rq_return_descs fnic_rq_return_descs
37 #define vnic_rq_service fnic_rq_service
38 #define vnic_rq_fill fnic_rq_fill
39 #define vnic_rq_free fnic_rq_free
40 #define vnic_rq_alloc fnic_rq_alloc
41 #define vnic_rq_init fnic_rq_init
42 #define vnic_rq_error_status fnic_rq_error_status
43 #define vnic_rq_enable fnic_rq_enable
44 #define vnic_rq_disable fnic_rq_disable
45 #define vnic_rq_clean fnic_rq_clean
46 
47 /* Receive queue control */
48 struct vnic_rq_ctrl {
49  u64 ring_base; /* 0x00 */
50  u32 ring_size; /* 0x08 */
51  u32 pad0;
52  u32 posted_index; /* 0x10 */
53  u32 pad1;
54  u32 cq_index; /* 0x18 */
55  u32 pad2;
56  u32 enable; /* 0x20 */
57  u32 pad3;
58  u32 running; /* 0x28 */
59  u32 pad4;
60  u32 fetch_index; /* 0x30 */
61  u32 pad5;
62  u32 error_interrupt_enable; /* 0x38 */
63  u32 pad6;
64  u32 error_interrupt_offset; /* 0x40 */
65  u32 pad7;
66  u32 error_status; /* 0x48 */
67  u32 pad8;
68  u32 dropped_packet_count; /* 0x50 */
69  u32 pad9;
70  u32 dropped_packet_count_rc; /* 0x58 */
71  u32 pad10;
72 };
73 
74 /* Break the vnic_rq_buf allocations into blocks of 64 entries */
75 #define VNIC_RQ_BUF_BLK_ENTRIES 64
76 #define VNIC_RQ_BUF_BLK_SZ \
77  (VNIC_RQ_BUF_BLK_ENTRIES * sizeof(struct vnic_rq_buf))
78 #define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
79  DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES)
80 #define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
81 
82 struct vnic_rq_buf {
83  struct vnic_rq_buf *next;
85  void *os_buf;
86  unsigned int os_buf_index;
87  unsigned int len;
88  unsigned int index;
89  void *desc;
90 };
91 
92 struct vnic_rq {
93  unsigned int index;
94  struct vnic_dev *vdev;
95  struct vnic_rq_ctrl __iomem *ctrl; /* memory-mapped */
96  struct vnic_dev_ring ring;
98  struct vnic_rq_buf *to_use;
99  struct vnic_rq_buf *to_clean;
100  void *os_buf_head;
101  unsigned int buf_index;
102  unsigned int pkts_outstanding;
103 };
104 
105 static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
106 {
107  /* how many does SW own? */
108  return rq->ring.desc_avail;
109 }
110 
111 static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
112 {
113  /* how many does HW own? */
114  return rq->ring.desc_count - rq->ring.desc_avail - 1;
115 }
116 
117 static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
118 {
119  return rq->to_use->desc;
120 }
121 
122 static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
123 {
124  return rq->to_use->index;
125 }
126 
127 static inline unsigned int vnic_rq_next_buf_index(struct vnic_rq *rq)
128 {
129  return rq->buf_index++;
130 }
131 
132 static inline void vnic_rq_post(struct vnic_rq *rq,
133  void *os_buf, unsigned int os_buf_index,
134  dma_addr_t dma_addr, unsigned int len)
135 {
136  struct vnic_rq_buf *buf = rq->to_use;
137 
138  buf->os_buf = os_buf;
139  buf->os_buf_index = os_buf_index;
140  buf->dma_addr = dma_addr;
141  buf->len = len;
142 
143  buf = buf->next;
144  rq->to_use = buf;
145  rq->ring.desc_avail--;
146 
147  /* Move the posted_index every nth descriptor
148  */
149 
150 #ifndef VNIC_RQ_RETURN_RATE
151 #define VNIC_RQ_RETURN_RATE 0xf /* keep 2^n - 1 */
152 #endif
153 
154  if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
155  /* Adding write memory barrier prevents compiler and/or CPU
156  * reordering, thus avoiding descriptor posting before
157  * descriptor is initialized. Otherwise, hardware can read
158  * stale descriptor fields.
159  */
160  wmb();
161  iowrite32(buf->index, &rq->ctrl->posted_index);
162  }
163 }
164 
165 static inline int vnic_rq_posting_soon(struct vnic_rq *rq)
166 {
167  return (rq->to_use->index & VNIC_RQ_RETURN_RATE) == 0;
168 }
169 
170 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
171 {
172  rq->ring.desc_avail += count;
173 }
174 
178 };
179 
180 static inline void vnic_rq_service(struct vnic_rq *rq,
181  struct cq_desc *cq_desc, u16 completed_index,
182  int desc_return, void (*buf_service)(struct vnic_rq *rq,
183  struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
184  int skipped, void *opaque), void *opaque)
185 {
186  struct vnic_rq_buf *buf;
187  int skipped;
188 
189  buf = rq->to_clean;
190  while (1) {
191 
192  skipped = (buf->index != completed_index);
193 
194  (*buf_service)(rq, cq_desc, buf, skipped, opaque);
195 
196  if (desc_return == VNIC_RQ_RETURN_DESC)
197  rq->ring.desc_avail++;
198 
199  rq->to_clean = buf->next;
200 
201  if (!skipped)
202  break;
203 
204  buf = rq->to_clean;
205  }
206 }
207 
208 static inline int vnic_rq_fill(struct vnic_rq *rq,
209  int (*buf_fill)(struct vnic_rq *rq))
210 {
211  int err;
212 
213  while (vnic_rq_desc_avail(rq) > 1) {
214 
215  err = (*buf_fill)(rq);
216  if (err)
217  return err;
218  }
219 
220  return 0;
221 }
222 
223 void vnic_rq_free(struct vnic_rq *rq);
224 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
225  unsigned int desc_count, unsigned int desc_size);
226 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
227  unsigned int error_interrupt_enable,
228  unsigned int error_interrupt_offset);
229 unsigned int vnic_rq_error_status(struct vnic_rq *rq);
230 void vnic_rq_enable(struct vnic_rq *rq);
231 int vnic_rq_disable(struct vnic_rq *rq);
232 void vnic_rq_clean(struct vnic_rq *rq,
233  void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
234 
235 #endif /* _VNIC_RQ_H_ */