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 #ifndef _VNIC_RQ_H_
21 #define _VNIC_RQ_H_
22 
23 #include <linux/pci.h>
24 
25 #include "vnic_dev.h"
26 #include "vnic_cq.h"
27 
28 /* Receive queue control */
29 struct vnic_rq_ctrl {
30 	u64 ring_base;			/* 0x00 */
31 	u32 ring_size;			/* 0x08 */
32 	u32 pad0;
33 	u32 posted_index;		/* 0x10 */
34 	u32 pad1;
35 	u32 cq_index;			/* 0x18 */
36 	u32 pad2;
37 	u32 enable;			/* 0x20 */
38 	u32 pad3;
39 	u32 running;			/* 0x28 */
40 	u32 pad4;
41 	u32 fetch_index;		/* 0x30 */
42 	u32 pad5;
43 	u32 error_interrupt_enable;	/* 0x38 */
44 	u32 pad6;
45 	u32 error_interrupt_offset;	/* 0x40 */
46 	u32 pad7;
47 	u32 error_status;		/* 0x48 */
48 	u32 pad8;
49 	u32 dropped_packet_count;	/* 0x50 */
50 	u32 pad9;
51 	u32 dropped_packet_count_rc;	/* 0x58 */
52 	u32 pad10;
53 };
54 
55 /* Break the vnic_rq_buf allocations into blocks of 32/64 entries */
56 #define VNIC_RQ_BUF_MIN_BLK_ENTRIES 32
57 #define VNIC_RQ_BUF_DFLT_BLK_ENTRIES 64
58 #define VNIC_RQ_BUF_BLK_ENTRIES(entries) \
59 	((unsigned int)((entries < VNIC_RQ_BUF_DFLT_BLK_ENTRIES) ? \
60 	VNIC_RQ_BUF_MIN_BLK_ENTRIES : VNIC_RQ_BUF_DFLT_BLK_ENTRIES))
61 #define VNIC_RQ_BUF_BLK_SZ(entries) \
62 	(VNIC_RQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_rq_buf))
63 #define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
64 	DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES(entries))
65 #define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
66 
67 struct vnic_rq_buf {
68 	struct vnic_rq_buf *next;
69 	dma_addr_t dma_addr;
70 	void *os_buf;
71 	unsigned int os_buf_index;
72 	unsigned int len;
73 	unsigned int index;
74 	void *desc;
75 	uint64_t wr_id;
76 };
77 
78 struct vnic_rq {
79 	unsigned int index;
80 	struct vnic_dev *vdev;
81 	struct vnic_rq_ctrl __iomem *ctrl;              /* memory-mapped */
82 	struct vnic_dev_ring ring;
83 	struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
84 	struct vnic_rq_buf *to_use;
85 	struct vnic_rq_buf *to_clean;
86 	void *os_buf_head;
87 	unsigned int pkts_outstanding;
88 #ifdef CONFIG_NET_RX_BUSY_POLL
89 #define ENIC_POLL_STATE_IDLE		0
90 #define ENIC_POLL_STATE_NAPI		(1 << 0) /* NAPI owns this poll */
91 #define ENIC_POLL_STATE_POLL		(1 << 1) /* poll owns this poll */
92 #define ENIC_POLL_STATE_NAPI_YIELD	(1 << 2) /* NAPI yielded this poll */
93 #define ENIC_POLL_STATE_POLL_YIELD	(1 << 3) /* poll yielded this poll */
94 #define ENIC_POLL_YIELD			(ENIC_POLL_STATE_NAPI_YIELD |	\
95 					 ENIC_POLL_STATE_POLL_YIELD)
96 #define ENIC_POLL_LOCKED		(ENIC_POLL_STATE_NAPI |		\
97 					 ENIC_POLL_STATE_POLL)
98 #define ENIC_POLL_USER_PEND		(ENIC_POLL_STATE_POLL |		\
99 					 ENIC_POLL_STATE_POLL_YIELD)
100 	unsigned int bpoll_state;
101 	spinlock_t bpoll_lock;
102 #endif /* CONFIG_NET_RX_BUSY_POLL */
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 void vnic_rq_post(struct vnic_rq *rq,
128 	void *os_buf, unsigned int os_buf_index,
129 	dma_addr_t dma_addr, unsigned int len,
130 	uint64_t wrid)
131 {
132 	struct vnic_rq_buf *buf = rq->to_use;
133 
134 	buf->os_buf = os_buf;
135 	buf->os_buf_index = os_buf_index;
136 	buf->dma_addr = dma_addr;
137 	buf->len = len;
138 	buf->wr_id = wrid;
139 
140 	buf = buf->next;
141 	rq->to_use = buf;
142 	rq->ring.desc_avail--;
143 
144 	/* Move the posted_index every nth descriptor
145 	 */
146 
147 #ifndef VNIC_RQ_RETURN_RATE
148 #define VNIC_RQ_RETURN_RATE		0xf	/* keep 2^n - 1 */
149 #endif
150 
151 	if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
152 		/* Adding write memory barrier prevents compiler and/or CPU
153 		 * reordering, thus avoiding descriptor posting before
154 		 * descriptor is initialized. Otherwise, hardware can read
155 		 * stale descriptor fields.
156 		 */
157 		wmb();
158 		iowrite32(buf->index, &rq->ctrl->posted_index);
159 	}
160 }
161 
162 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
163 {
164 	rq->ring.desc_avail += count;
165 }
166 
167 enum desc_return_options {
168 	VNIC_RQ_RETURN_DESC,
169 	VNIC_RQ_DEFER_RETURN_DESC,
170 };
171 
172 static inline void vnic_rq_service(struct vnic_rq *rq,
173 	struct cq_desc *cq_desc, u16 completed_index,
174 	int desc_return, void (*buf_service)(struct vnic_rq *rq,
175 	struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
176 	int skipped, void *opaque), void *opaque)
177 {
178 	struct vnic_rq_buf *buf;
179 	int skipped;
180 
181 	buf = rq->to_clean;
182 	while (1) {
183 
184 		skipped = (buf->index != completed_index);
185 
186 		(*buf_service)(rq, cq_desc, buf, skipped, opaque);
187 
188 		if (desc_return == VNIC_RQ_RETURN_DESC)
189 			rq->ring.desc_avail++;
190 
191 		rq->to_clean = buf->next;
192 
193 		if (!skipped)
194 			break;
195 
196 		buf = rq->to_clean;
197 	}
198 }
199 
200 static inline int vnic_rq_fill(struct vnic_rq *rq,
201 	int (*buf_fill)(struct vnic_rq *rq))
202 {
203 	int err;
204 
205 	while (vnic_rq_desc_avail(rq) > 0) {
206 
207 		err = (*buf_fill)(rq);
208 		if (err)
209 			return err;
210 	}
211 
212 	return 0;
213 }
214 
215 #ifdef CONFIG_NET_RX_BUSY_POLL
216 static inline void enic_busy_poll_init_lock(struct vnic_rq *rq)
217 {
218 	spin_lock_init(&rq->bpoll_lock);
219 	rq->bpoll_state = ENIC_POLL_STATE_IDLE;
220 }
221 
222 static inline bool enic_poll_lock_napi(struct vnic_rq *rq)
223 {
224 	bool rc = true;
225 
226 	spin_lock(&rq->bpoll_lock);
227 	if (rq->bpoll_state & ENIC_POLL_LOCKED) {
228 		WARN_ON(rq->bpoll_state & ENIC_POLL_STATE_NAPI);
229 		rq->bpoll_state |= ENIC_POLL_STATE_NAPI_YIELD;
230 		rc = false;
231 	} else {
232 		rq->bpoll_state = ENIC_POLL_STATE_NAPI;
233 	}
234 	spin_unlock(&rq->bpoll_lock);
235 
236 	return rc;
237 }
238 
239 static inline bool enic_poll_unlock_napi(struct vnic_rq *rq)
240 {
241 	bool rc = false;
242 
243 	spin_lock(&rq->bpoll_lock);
244 	WARN_ON(rq->bpoll_state &
245 		(ENIC_POLL_STATE_POLL | ENIC_POLL_STATE_NAPI_YIELD));
246 	if (rq->bpoll_state & ENIC_POLL_STATE_POLL_YIELD)
247 		rc = true;
248 	rq->bpoll_state = ENIC_POLL_STATE_IDLE;
249 	spin_unlock(&rq->bpoll_lock);
250 
251 	return rc;
252 }
253 
254 static inline bool enic_poll_lock_poll(struct vnic_rq *rq)
255 {
256 	bool rc = true;
257 
258 	spin_lock_bh(&rq->bpoll_lock);
259 	if (rq->bpoll_state & ENIC_POLL_LOCKED) {
260 		rq->bpoll_state |= ENIC_POLL_STATE_POLL_YIELD;
261 		rc = false;
262 	} else {
263 		rq->bpoll_state |= ENIC_POLL_STATE_POLL;
264 	}
265 	spin_unlock_bh(&rq->bpoll_lock);
266 
267 	return rc;
268 }
269 
270 static inline bool enic_poll_unlock_poll(struct vnic_rq *rq)
271 {
272 	bool rc = false;
273 
274 	spin_lock_bh(&rq->bpoll_lock);
275 	WARN_ON(rq->bpoll_state & ENIC_POLL_STATE_NAPI);
276 	if (rq->bpoll_state & ENIC_POLL_STATE_POLL_YIELD)
277 		rc = true;
278 	rq->bpoll_state = ENIC_POLL_STATE_IDLE;
279 	spin_unlock_bh(&rq->bpoll_lock);
280 
281 	return rc;
282 }
283 
284 static inline bool enic_poll_busy_polling(struct vnic_rq *rq)
285 {
286 	WARN_ON(!(rq->bpoll_state & ENIC_POLL_LOCKED));
287 	return rq->bpoll_state & ENIC_POLL_USER_PEND;
288 }
289 
290 #else
291 
292 static inline void enic_busy_poll_init_lock(struct vnic_rq *rq)
293 {
294 }
295 
296 static inline bool enic_poll_lock_napi(struct vnic_rq *rq)
297 {
298 	return true;
299 }
300 
301 static inline bool enic_poll_unlock_napi(struct vnic_rq *rq)
302 {
303 	return false;
304 }
305 
306 static inline bool enic_poll_lock_poll(struct vnic_rq *rq)
307 {
308 	return false;
309 }
310 
311 static inline bool enic_poll_unlock_poll(struct vnic_rq *rq)
312 {
313 	return false;
314 }
315 
316 static inline bool enic_poll_ll_polling(struct vnic_rq *rq)
317 {
318 	return false;
319 }
320 #endif /* CONFIG_NET_RX_BUSY_POLL */
321 
322 void vnic_rq_free(struct vnic_rq *rq);
323 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
324 	unsigned int desc_count, unsigned int desc_size);
325 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
326 	unsigned int error_interrupt_enable,
327 	unsigned int error_interrupt_offset);
328 unsigned int vnic_rq_error_status(struct vnic_rq *rq);
329 void vnic_rq_enable(struct vnic_rq *rq);
330 int vnic_rq_disable(struct vnic_rq *rq);
331 void vnic_rq_clean(struct vnic_rq *rq,
332 	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
333 
334 #endif /* _VNIC_RQ_H_ */
335