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 #include <linux/netdevice.h>
25 
26 #include "vnic_dev.h"
27 #include "vnic_cq.h"
28 
29 /* Receive queue control */
30 struct vnic_rq_ctrl {
31 	u64 ring_base;			/* 0x00 */
32 	u32 ring_size;			/* 0x08 */
33 	u32 pad0;
34 	u32 posted_index;		/* 0x10 */
35 	u32 pad1;
36 	u32 cq_index;			/* 0x18 */
37 	u32 pad2;
38 	u32 enable;			/* 0x20 */
39 	u32 pad3;
40 	u32 running;			/* 0x28 */
41 	u32 pad4;
42 	u32 fetch_index;		/* 0x30 */
43 	u32 pad5;
44 	u32 error_interrupt_enable;	/* 0x38 */
45 	u32 pad6;
46 	u32 error_interrupt_offset;	/* 0x40 */
47 	u32 pad7;
48 	u32 error_status;		/* 0x48 */
49 	u32 pad8;
50 	u32 dropped_packet_count;	/* 0x50 */
51 	u32 pad9;
52 	u32 dropped_packet_count_rc;	/* 0x58 */
53 	u32 pad10;
54 };
55 
56 /* Break the vnic_rq_buf allocations into blocks of 32/64 entries */
57 #define VNIC_RQ_BUF_MIN_BLK_ENTRIES 32
58 #define VNIC_RQ_BUF_DFLT_BLK_ENTRIES 64
59 #define VNIC_RQ_BUF_BLK_ENTRIES(entries) \
60 	((unsigned int)((entries < VNIC_RQ_BUF_DFLT_BLK_ENTRIES) ? \
61 	VNIC_RQ_BUF_MIN_BLK_ENTRIES : VNIC_RQ_BUF_DFLT_BLK_ENTRIES))
62 #define VNIC_RQ_BUF_BLK_SZ(entries) \
63 	(VNIC_RQ_BUF_BLK_ENTRIES(entries) * sizeof(struct vnic_rq_buf))
64 #define VNIC_RQ_BUF_BLKS_NEEDED(entries) \
65 	DIV_ROUND_UP(entries, VNIC_RQ_BUF_BLK_ENTRIES(entries))
66 #define VNIC_RQ_BUF_BLKS_MAX VNIC_RQ_BUF_BLKS_NEEDED(4096)
67 
68 struct vnic_rq_buf {
69 	struct vnic_rq_buf *next;
70 	dma_addr_t dma_addr;
71 	void *os_buf;
72 	unsigned int os_buf_index;
73 	unsigned int len;
74 	unsigned int index;
75 	void *desc;
76 	uint64_t wr_id;
77 };
78 
79 enum enic_poll_state {
80 	ENIC_POLL_STATE_IDLE,
81 	ENIC_POLL_STATE_NAPI,
82 	ENIC_POLL_STATE_POLL
83 };
84 
85 struct vnic_rq {
86 	unsigned int index;
87 	struct vnic_dev *vdev;
88 	struct vnic_rq_ctrl __iomem *ctrl;              /* memory-mapped */
89 	struct vnic_dev_ring ring;
90 	struct vnic_rq_buf *bufs[VNIC_RQ_BUF_BLKS_MAX];
91 	struct vnic_rq_buf *to_use;
92 	struct vnic_rq_buf *to_clean;
93 	void *os_buf_head;
94 	unsigned int pkts_outstanding;
95 #ifdef CONFIG_NET_RX_BUSY_POLL
96 	atomic_t bpoll_state;
97 #endif /* CONFIG_NET_RX_BUSY_POLL */
98 };
99 
100 static inline unsigned int vnic_rq_desc_avail(struct vnic_rq *rq)
101 {
102 	/* how many does SW own? */
103 	return rq->ring.desc_avail;
104 }
105 
106 static inline unsigned int vnic_rq_desc_used(struct vnic_rq *rq)
107 {
108 	/* how many does HW own? */
109 	return rq->ring.desc_count - rq->ring.desc_avail - 1;
110 }
111 
112 static inline void *vnic_rq_next_desc(struct vnic_rq *rq)
113 {
114 	return rq->to_use->desc;
115 }
116 
117 static inline unsigned int vnic_rq_next_index(struct vnic_rq *rq)
118 {
119 	return rq->to_use->index;
120 }
121 
122 static inline void vnic_rq_post(struct vnic_rq *rq,
123 	void *os_buf, unsigned int os_buf_index,
124 	dma_addr_t dma_addr, unsigned int len,
125 	uint64_t wrid)
126 {
127 	struct vnic_rq_buf *buf = rq->to_use;
128 
129 	buf->os_buf = os_buf;
130 	buf->os_buf_index = os_buf_index;
131 	buf->dma_addr = dma_addr;
132 	buf->len = len;
133 	buf->wr_id = wrid;
134 
135 	buf = buf->next;
136 	rq->to_use = buf;
137 	rq->ring.desc_avail--;
138 
139 	/* Move the posted_index every nth descriptor
140 	 */
141 
142 #ifndef VNIC_RQ_RETURN_RATE
143 #define VNIC_RQ_RETURN_RATE		0xf	/* keep 2^n - 1 */
144 #endif
145 
146 	if ((buf->index & VNIC_RQ_RETURN_RATE) == 0) {
147 		/* Adding write memory barrier prevents compiler and/or CPU
148 		 * reordering, thus avoiding descriptor posting before
149 		 * descriptor is initialized. Otherwise, hardware can read
150 		 * stale descriptor fields.
151 		 */
152 		wmb();
153 		iowrite32(buf->index, &rq->ctrl->posted_index);
154 	}
155 }
156 
157 static inline void vnic_rq_return_descs(struct vnic_rq *rq, unsigned int count)
158 {
159 	rq->ring.desc_avail += count;
160 }
161 
162 enum desc_return_options {
163 	VNIC_RQ_RETURN_DESC,
164 	VNIC_RQ_DEFER_RETURN_DESC,
165 };
166 
167 static inline void vnic_rq_service(struct vnic_rq *rq,
168 	struct cq_desc *cq_desc, u16 completed_index,
169 	int desc_return, void (*buf_service)(struct vnic_rq *rq,
170 	struct cq_desc *cq_desc, struct vnic_rq_buf *buf,
171 	int skipped, void *opaque), void *opaque)
172 {
173 	struct vnic_rq_buf *buf;
174 	int skipped;
175 
176 	buf = rq->to_clean;
177 	while (1) {
178 
179 		skipped = (buf->index != completed_index);
180 
181 		(*buf_service)(rq, cq_desc, buf, skipped, opaque);
182 
183 		if (desc_return == VNIC_RQ_RETURN_DESC)
184 			rq->ring.desc_avail++;
185 
186 		rq->to_clean = buf->next;
187 
188 		if (!skipped)
189 			break;
190 
191 		buf = rq->to_clean;
192 	}
193 }
194 
195 static inline int vnic_rq_fill(struct vnic_rq *rq,
196 	int (*buf_fill)(struct vnic_rq *rq))
197 {
198 	int err;
199 
200 	while (vnic_rq_desc_avail(rq) > 0) {
201 
202 		err = (*buf_fill)(rq);
203 		if (err)
204 			return err;
205 	}
206 
207 	return 0;
208 }
209 
210 #ifdef CONFIG_NET_RX_BUSY_POLL
211 static inline void enic_busy_poll_init_lock(struct vnic_rq *rq)
212 {
213 	atomic_set(&rq->bpoll_state, ENIC_POLL_STATE_IDLE);
214 }
215 
216 static inline bool enic_poll_lock_napi(struct vnic_rq *rq)
217 {
218 	int rc = atomic_cmpxchg(&rq->bpoll_state, ENIC_POLL_STATE_IDLE,
219 				ENIC_POLL_STATE_NAPI);
220 
221 	return (rc == ENIC_POLL_STATE_IDLE);
222 }
223 
224 static inline void enic_poll_unlock_napi(struct vnic_rq *rq,
225 					 struct napi_struct *napi)
226 {
227 	WARN_ON(atomic_read(&rq->bpoll_state) != ENIC_POLL_STATE_NAPI);
228 	napi_gro_flush(napi, false);
229 	atomic_set(&rq->bpoll_state, ENIC_POLL_STATE_IDLE);
230 }
231 
232 static inline bool enic_poll_lock_poll(struct vnic_rq *rq)
233 {
234 	int rc = atomic_cmpxchg(&rq->bpoll_state, ENIC_POLL_STATE_IDLE,
235 				ENIC_POLL_STATE_POLL);
236 
237 	return (rc == ENIC_POLL_STATE_IDLE);
238 }
239 
240 
241 static inline void enic_poll_unlock_poll(struct vnic_rq *rq)
242 {
243 	WARN_ON(atomic_read(&rq->bpoll_state) != ENIC_POLL_STATE_POLL);
244 	atomic_set(&rq->bpoll_state, ENIC_POLL_STATE_IDLE);
245 }
246 
247 static inline bool enic_poll_busy_polling(struct vnic_rq *rq)
248 {
249 	return atomic_read(&rq->bpoll_state) & ENIC_POLL_STATE_POLL;
250 }
251 
252 #else
253 
254 static inline void enic_busy_poll_init_lock(struct vnic_rq *rq)
255 {
256 }
257 
258 static inline bool enic_poll_lock_napi(struct vnic_rq *rq)
259 {
260 	return true;
261 }
262 
263 static inline bool enic_poll_unlock_napi(struct vnic_rq *rq,
264 					 struct napi_struct *napi)
265 {
266 	return false;
267 }
268 
269 static inline bool enic_poll_lock_poll(struct vnic_rq *rq)
270 {
271 	return false;
272 }
273 
274 static inline bool enic_poll_unlock_poll(struct vnic_rq *rq)
275 {
276 	return false;
277 }
278 
279 static inline bool enic_poll_ll_polling(struct vnic_rq *rq)
280 {
281 	return false;
282 }
283 #endif /* CONFIG_NET_RX_BUSY_POLL */
284 
285 void vnic_rq_free(struct vnic_rq *rq);
286 int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
287 	unsigned int desc_count, unsigned int desc_size);
288 void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
289 	unsigned int error_interrupt_enable,
290 	unsigned int error_interrupt_offset);
291 unsigned int vnic_rq_error_status(struct vnic_rq *rq);
292 void vnic_rq_enable(struct vnic_rq *rq);
293 int vnic_rq_disable(struct vnic_rq *rq);
294 void vnic_rq_clean(struct vnic_rq *rq,
295 	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf));
296 
297 #endif /* _VNIC_RQ_H_ */
298