1 /*
2  * Copyright (C) 2014 Freescale Semiconductor
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  */
6 
7 #include "qbman_portal.h"
8 
9 /* QBMan portal management command codes */
10 #define QBMAN_MC_ACQUIRE       0x30
11 #define QBMAN_WQCHAN_CONFIGURE 0x46
12 
13 /* CINH register offsets */
14 #define QBMAN_CINH_SWP_EQAR    0x8c0
15 #define QBMAN_CINH_SWP_DCAP    0xac0
16 #define QBMAN_CINH_SWP_SDQCR   0xb00
17 #define QBMAN_CINH_SWP_RAR     0xcc0
18 
19 /* CENA register offsets */
20 #define QBMAN_CENA_SWP_EQCR(n) (0x000 + ((uint32_t)(n) << 6))
21 #define QBMAN_CENA_SWP_DQRR(n) (0x200 + ((uint32_t)(n) << 6))
22 #define QBMAN_CENA_SWP_RCR(n)  (0x400 + ((uint32_t)(n) << 6))
23 #define QBMAN_CENA_SWP_CR      0x600
24 #define QBMAN_CENA_SWP_RR(vb)  (0x700 + ((uint32_t)(vb) >> 1))
25 #define QBMAN_CENA_SWP_VDQCR   0x780
26 
27 /* Reverse mapping of QBMAN_CENA_SWP_DQRR() */
28 #define QBMAN_IDX_FROM_DQRR(p) (((unsigned long)p & 0xff) >> 6)
29 
30 /*******************************/
31 /* Pre-defined attribute codes */
32 /*******************************/
33 
34 struct qb_attr_code code_generic_verb = QB_CODE(0, 0, 7);
35 struct qb_attr_code code_generic_rslt = QB_CODE(0, 8, 8);
36 
37 /*************************/
38 /* SDQCR attribute codes */
39 /*************************/
40 
41 /* we put these here because at least some of them are required by
42  * qbman_swp_init() */
43 struct qb_attr_code code_sdqcr_dct = QB_CODE(0, 24, 2);
44 struct qb_attr_code code_sdqcr_fc = QB_CODE(0, 29, 1);
45 struct qb_attr_code code_sdqcr_tok = QB_CODE(0, 16, 8);
46 #define CODE_SDQCR_DQSRC(n) QB_CODE(0, n, 1)
47 enum qbman_sdqcr_dct {
48 	qbman_sdqcr_dct_null = 0,
49 	qbman_sdqcr_dct_prio_ics,
50 	qbman_sdqcr_dct_active_ics,
51 	qbman_sdqcr_dct_active
52 };
53 enum qbman_sdqcr_fc {
54 	qbman_sdqcr_fc_one = 0,
55 	qbman_sdqcr_fc_up_to_3 = 1
56 };
57 
58 /*********************************/
59 /* Portal constructor/destructor */
60 /*********************************/
61 
62 /* Software portals should always be in the power-on state when we initialise,
63  * due to the CCSR-based portal reset functionality that MC has. */
64 struct qbman_swp *qbman_swp_init(const struct qbman_swp_desc *d)
65 {
66 	int ret;
67 	struct qbman_swp *p = malloc(sizeof(struct qbman_swp));
68 
69 	if (!p)
70 		return NULL;
71 	p->desc = d;
72 #ifdef QBMAN_CHECKING
73 	p->mc.check = swp_mc_can_start;
74 #endif
75 	p->mc.valid_bit = QB_VALID_BIT;
76 	p->sdq = 0;
77 	qb_attr_code_encode(&code_sdqcr_dct, &p->sdq, qbman_sdqcr_dct_prio_ics);
78 	qb_attr_code_encode(&code_sdqcr_fc, &p->sdq, qbman_sdqcr_fc_up_to_3);
79 	qb_attr_code_encode(&code_sdqcr_tok, &p->sdq, 0xbb);
80 	atomic_set(&p->vdq.busy, 1);
81 	p->vdq.valid_bit = QB_VALID_BIT;
82 	p->dqrr.next_idx = 0;
83 	p->dqrr.valid_bit = QB_VALID_BIT;
84 	ret = qbman_swp_sys_init(&p->sys, d);
85 	if (ret) {
86 		free(p);
87 		printf("qbman_swp_sys_init() failed %d\n", ret);
88 		return NULL;
89 	}
90 	qbman_cinh_write(&p->sys, QBMAN_CINH_SWP_SDQCR, p->sdq);
91 	return p;
92 }
93 
94 /***********************/
95 /* Management commands */
96 /***********************/
97 
98 /*
99  * Internal code common to all types of management commands.
100  */
101 
102 void *qbman_swp_mc_start(struct qbman_swp *p)
103 {
104 	void *ret;
105 	int *return_val;
106 #ifdef QBMAN_CHECKING
107 	BUG_ON(p->mc.check != swp_mc_can_start);
108 #endif
109 	ret = qbman_cena_write_start(&p->sys, QBMAN_CENA_SWP_CR);
110 #ifdef QBMAN_CHECKING
111 	return_val = (int *)ret;
112 	if (!(*return_val))
113 		p->mc.check = swp_mc_can_submit;
114 #endif
115 	return ret;
116 }
117 
118 void qbman_swp_mc_submit(struct qbman_swp *p, void *cmd, uint32_t cmd_verb)
119 {
120 	uint32_t *v = cmd;
121 #ifdef QBMAN_CHECKING
122 	BUG_ON(p->mc.check != swp_mc_can_submit);
123 #endif
124 	lwsync();
125 	/* TBD: "|=" is going to hurt performance. Need to move as many fields
126 	 * out of word zero, and for those that remain, the "OR" needs to occur
127 	 * at the caller side. This debug check helps to catch cases where the
128 	 * caller wants to OR but has forgotten to do so. */
129 	BUG_ON((*v & cmd_verb) != *v);
130 	*v = cmd_verb | p->mc.valid_bit;
131 	qbman_cena_write_complete(&p->sys, QBMAN_CENA_SWP_CR, cmd);
132 	/* TODO: add prefetch support for GPP */
133 #ifdef QBMAN_CHECKING
134 	p->mc.check = swp_mc_can_poll;
135 #endif
136 }
137 
138 void *qbman_swp_mc_result(struct qbman_swp *p)
139 {
140 	uint32_t *ret, verb;
141 #ifdef QBMAN_CHECKING
142 	BUG_ON(p->mc.check != swp_mc_can_poll);
143 #endif
144 	ret = qbman_cena_read(&p->sys, QBMAN_CENA_SWP_RR(p->mc.valid_bit));
145 	/* Remove the valid-bit - command completed iff the rest is non-zero */
146 	verb = ret[0] & ~QB_VALID_BIT;
147 	if (!verb)
148 		return NULL;
149 #ifdef QBMAN_CHECKING
150 	p->mc.check = swp_mc_can_start;
151 #endif
152 	p->mc.valid_bit ^= QB_VALID_BIT;
153 	return ret;
154 }
155 
156 /***********/
157 /* Enqueue */
158 /***********/
159 
160 /* These should be const, eventually */
161 static struct qb_attr_code code_eq_cmd = QB_CODE(0, 0, 2);
162 static struct qb_attr_code code_eq_orp_en = QB_CODE(0, 2, 1);
163 static struct qb_attr_code code_eq_tgt_id = QB_CODE(2, 0, 24);
164 /* static struct qb_attr_code code_eq_tag = QB_CODE(3, 0, 32); */
165 static struct qb_attr_code code_eq_qd_en = QB_CODE(0, 4, 1);
166 static struct qb_attr_code code_eq_qd_bin = QB_CODE(4, 0, 16);
167 static struct qb_attr_code code_eq_qd_pri = QB_CODE(4, 16, 4);
168 static struct qb_attr_code code_eq_rsp_stash = QB_CODE(5, 16, 1);
169 static struct qb_attr_code code_eq_rsp_lo = QB_CODE(6, 0, 32);
170 
171 enum qbman_eq_cmd_e {
172 	/* No enqueue, primarily for plugging ORP gaps for dropped frames */
173 	qbman_eq_cmd_empty,
174 	/* DMA an enqueue response once complete */
175 	qbman_eq_cmd_respond,
176 	/* DMA an enqueue response only if the enqueue fails */
177 	qbman_eq_cmd_respond_reject
178 };
179 
180 void qbman_eq_desc_clear(struct qbman_eq_desc *d)
181 {
182 	memset(d, 0, sizeof(*d));
183 }
184 
185 void qbman_eq_desc_set_no_orp(struct qbman_eq_desc *d, int respond_success)
186 {
187 	uint32_t *cl = qb_cl(d);
188 
189 	qb_attr_code_encode(&code_eq_orp_en, cl, 0);
190 	qb_attr_code_encode(&code_eq_cmd, cl,
191 			    respond_success ? qbman_eq_cmd_respond :
192 					      qbman_eq_cmd_respond_reject);
193 }
194 
195 void qbman_eq_desc_set_response(struct qbman_eq_desc *d,
196 				dma_addr_t storage_phys,
197 				int stash)
198 {
199 	uint32_t *cl = qb_cl(d);
200 
201 	qb_attr_code_encode_64(&code_eq_rsp_lo, (uint64_t *)cl, storage_phys);
202 	qb_attr_code_encode(&code_eq_rsp_stash, cl, !!stash);
203 }
204 
205 
206 void qbman_eq_desc_set_qd(struct qbman_eq_desc *d, uint32_t qdid,
207 			  uint32_t qd_bin, uint32_t qd_prio)
208 {
209 	uint32_t *cl = qb_cl(d);
210 
211 	qb_attr_code_encode(&code_eq_qd_en, cl, 1);
212 	qb_attr_code_encode(&code_eq_tgt_id, cl, qdid);
213 	qb_attr_code_encode(&code_eq_qd_bin, cl, qd_bin);
214 	qb_attr_code_encode(&code_eq_qd_pri, cl, qd_prio);
215 }
216 
217 #define EQAR_IDX(eqar)     ((eqar) & 0x7)
218 #define EQAR_VB(eqar)      ((eqar) & 0x80)
219 #define EQAR_SUCCESS(eqar) ((eqar) & 0x100)
220 
221 int qbman_swp_enqueue(struct qbman_swp *s, const struct qbman_eq_desc *d,
222 		      const struct qbman_fd *fd)
223 {
224 	uint32_t *p;
225 	const uint32_t *cl = qb_cl(d);
226 	uint32_t eqar = qbman_cinh_read(&s->sys, QBMAN_CINH_SWP_EQAR);
227 	debug("EQAR=%08x\n", eqar);
228 	if (!EQAR_SUCCESS(eqar))
229 		return -EBUSY;
230 	p = qbman_cena_write_start(&s->sys,
231 				   QBMAN_CENA_SWP_EQCR(EQAR_IDX(eqar)));
232 	word_copy(&p[1], &cl[1], 7);
233 	word_copy(&p[8], fd, sizeof(*fd) >> 2);
234 	lwsync();
235 	/* Set the verb byte, have to substitute in the valid-bit */
236 	p[0] = cl[0] | EQAR_VB(eqar);
237 	qbman_cena_write_complete(&s->sys,
238 				  QBMAN_CENA_SWP_EQCR(EQAR_IDX(eqar)),
239 				  p);
240 	return 0;
241 }
242 
243 /***************************/
244 /* Volatile (pull) dequeue */
245 /***************************/
246 
247 /* These should be const, eventually */
248 static struct qb_attr_code code_pull_dct = QB_CODE(0, 0, 2);
249 static struct qb_attr_code code_pull_dt = QB_CODE(0, 2, 2);
250 static struct qb_attr_code code_pull_rls = QB_CODE(0, 4, 1);
251 static struct qb_attr_code code_pull_stash = QB_CODE(0, 5, 1);
252 static struct qb_attr_code code_pull_numframes = QB_CODE(0, 8, 4);
253 static struct qb_attr_code code_pull_token = QB_CODE(0, 16, 8);
254 static struct qb_attr_code code_pull_dqsource = QB_CODE(1, 0, 24);
255 static struct qb_attr_code code_pull_rsp_lo = QB_CODE(2, 0, 32);
256 
257 enum qb_pull_dt_e {
258 	qb_pull_dt_channel,
259 	qb_pull_dt_workqueue,
260 	qb_pull_dt_framequeue
261 };
262 
263 void qbman_pull_desc_clear(struct qbman_pull_desc *d)
264 {
265 	memset(d, 0, sizeof(*d));
266 }
267 
268 void qbman_pull_desc_set_storage(struct qbman_pull_desc *d,
269 				 struct ldpaa_dq *storage,
270 				 dma_addr_t storage_phys,
271 				 int stash)
272 {
273 	uint32_t *cl = qb_cl(d);
274 
275 	/* Squiggle the pointer 'storage' into the extra 2 words of the
276 	 * descriptor (which aren't copied to the hw command) */
277 	*(void **)&cl[4] = storage;
278 	if (!storage) {
279 		qb_attr_code_encode(&code_pull_rls, cl, 0);
280 		return;
281 	}
282 	qb_attr_code_encode(&code_pull_rls, cl, 1);
283 	qb_attr_code_encode(&code_pull_stash, cl, !!stash);
284 	qb_attr_code_encode_64(&code_pull_rsp_lo, (uint64_t *)cl, storage_phys);
285 }
286 
287 void qbman_pull_desc_set_numframes(struct qbman_pull_desc *d, uint8_t numframes)
288 {
289 	uint32_t *cl = qb_cl(d);
290 
291 	BUG_ON(!numframes || (numframes > 16));
292 	qb_attr_code_encode(&code_pull_numframes, cl,
293 			    (uint32_t)(numframes - 1));
294 }
295 
296 void qbman_pull_desc_set_token(struct qbman_pull_desc *d, uint8_t token)
297 {
298 	uint32_t *cl = qb_cl(d);
299 
300 	qb_attr_code_encode(&code_pull_token, cl, token);
301 }
302 
303 void qbman_pull_desc_set_fq(struct qbman_pull_desc *d, uint32_t fqid)
304 {
305 	uint32_t *cl = qb_cl(d);
306 
307 	qb_attr_code_encode(&code_pull_dct, cl, 1);
308 	qb_attr_code_encode(&code_pull_dt, cl, qb_pull_dt_framequeue);
309 	qb_attr_code_encode(&code_pull_dqsource, cl, fqid);
310 }
311 
312 int qbman_swp_pull(struct qbman_swp *s, struct qbman_pull_desc *d)
313 {
314 	uint32_t *p;
315 	uint32_t *cl = qb_cl(d);
316 
317 	if (!atomic_dec_and_test(&s->vdq.busy)) {
318 		atomic_inc(&s->vdq.busy);
319 		return -EBUSY;
320 	}
321 	s->vdq.storage = *(void **)&cl[4];
322 	s->vdq.token = qb_attr_code_decode(&code_pull_token, cl);
323 	p = qbman_cena_write_start(&s->sys, QBMAN_CENA_SWP_VDQCR);
324 	word_copy(&p[1], &cl[1], 3);
325 	lwsync();
326 	/* Set the verb byte, have to substitute in the valid-bit */
327 	p[0] = cl[0] | s->vdq.valid_bit;
328 	s->vdq.valid_bit ^= QB_VALID_BIT;
329 	qbman_cena_write_complete(&s->sys, QBMAN_CENA_SWP_VDQCR, p);
330 	return 0;
331 }
332 
333 /****************/
334 /* Polling DQRR */
335 /****************/
336 
337 static struct qb_attr_code code_dqrr_verb = QB_CODE(0, 0, 8);
338 static struct qb_attr_code code_dqrr_response = QB_CODE(0, 0, 7);
339 static struct qb_attr_code code_dqrr_stat = QB_CODE(0, 8, 8);
340 
341 #define QBMAN_DQRR_RESPONSE_DQ        0x60
342 #define QBMAN_DQRR_RESPONSE_FQRN      0x21
343 #define QBMAN_DQRR_RESPONSE_FQRNI     0x22
344 #define QBMAN_DQRR_RESPONSE_FQPN      0x24
345 #define QBMAN_DQRR_RESPONSE_FQDAN     0x25
346 #define QBMAN_DQRR_RESPONSE_CDAN      0x26
347 #define QBMAN_DQRR_RESPONSE_CSCN_MEM  0x27
348 #define QBMAN_DQRR_RESPONSE_CGCU      0x28
349 #define QBMAN_DQRR_RESPONSE_BPSCN     0x29
350 #define QBMAN_DQRR_RESPONSE_CSCN_WQ   0x2a
351 
352 
353 /* NULL return if there are no unconsumed DQRR entries. Returns a DQRR entry
354  * only once, so repeated calls can return a sequence of DQRR entries, without
355  * requiring they be consumed immediately or in any particular order. */
356 const struct ldpaa_dq *qbman_swp_dqrr_next(struct qbman_swp *s)
357 {
358 	uint32_t verb;
359 	uint32_t response_verb;
360 	uint32_t flags;
361 	const struct ldpaa_dq *dq;
362 	const uint32_t *p;
363 
364 	dq = qbman_cena_read(&s->sys, QBMAN_CENA_SWP_DQRR(s->dqrr.next_idx));
365 	p = qb_cl(dq);
366 	verb = qb_attr_code_decode(&code_dqrr_verb, p);
367 
368 	/* If the valid-bit isn't of the expected polarity, nothing there. Note,
369 	 * in the DQRR reset bug workaround, we shouldn't need to skip these
370 	 * check, because we've already determined that a new entry is available
371 	 * and we've invalidated the cacheline before reading it, so the
372 	 * valid-bit behaviour is repaired and should tell us what we already
373 	 * knew from reading PI.
374 	 */
375 	if ((verb & QB_VALID_BIT) != s->dqrr.valid_bit) {
376 		qbman_cena_invalidate_prefetch(&s->sys,
377 					QBMAN_CENA_SWP_DQRR(s->dqrr.next_idx));
378 		return NULL;
379 	}
380 	/* There's something there. Move "next_idx" attention to the next ring
381 	 * entry (and prefetch it) before returning what we found. */
382 	s->dqrr.next_idx++;
383 	s->dqrr.next_idx &= QBMAN_DQRR_SIZE - 1; /* Wrap around at 4 */
384 	/* TODO: it's possible to do all this without conditionals, optimise it
385 	 * later. */
386 	if (!s->dqrr.next_idx)
387 		s->dqrr.valid_bit ^= QB_VALID_BIT;
388 
389 	/* If this is the final response to a volatile dequeue command
390 	   indicate that the vdq is no longer busy */
391 	flags = ldpaa_dq_flags(dq);
392 	response_verb = qb_attr_code_decode(&code_dqrr_response, &verb);
393 	if ((response_verb == QBMAN_DQRR_RESPONSE_DQ) &&
394 	    (flags & LDPAA_DQ_STAT_VOLATILE) &&
395 	    (flags & LDPAA_DQ_STAT_EXPIRED))
396 			atomic_inc(&s->vdq.busy);
397 
398 	qbman_cena_invalidate_prefetch(&s->sys,
399 				       QBMAN_CENA_SWP_DQRR(s->dqrr.next_idx));
400 	return dq;
401 }
402 
403 /* Consume DQRR entries previously returned from qbman_swp_dqrr_next(). */
404 void qbman_swp_dqrr_consume(struct qbman_swp *s, const struct ldpaa_dq *dq)
405 {
406 	qbman_cinh_write(&s->sys, QBMAN_CINH_SWP_DCAP, QBMAN_IDX_FROM_DQRR(dq));
407 }
408 
409 /*********************************/
410 /* Polling user-provided storage */
411 /*********************************/
412 
413 void qbman_dq_entry_set_oldtoken(struct ldpaa_dq *dq,
414 				 unsigned int num_entries,
415 				 uint8_t oldtoken)
416 {
417 	memset(dq, oldtoken, num_entries * sizeof(*dq));
418 }
419 
420 int qbman_dq_entry_has_newtoken(struct qbman_swp *s,
421 				const struct ldpaa_dq *dq,
422 				uint8_t newtoken)
423 {
424 	/* To avoid converting the little-endian DQ entry to host-endian prior
425 	 * to us knowing whether there is a valid entry or not (and run the
426 	 * risk of corrupting the incoming hardware LE write), we detect in
427 	 * hardware endianness rather than host. This means we need a different
428 	 * "code" depending on whether we are BE or LE in software, which is
429 	 * where DQRR_TOK_OFFSET comes in... */
430 	static struct qb_attr_code code_dqrr_tok_detect =
431 					QB_CODE(0, DQRR_TOK_OFFSET, 8);
432 	/* The user trying to poll for a result treats "dq" as const. It is
433 	 * however the same address that was provided to us non-const in the
434 	 * first place, for directing hardware DMA to. So we can cast away the
435 	 * const because it is mutable from our perspective. */
436 	uint32_t *p = qb_cl((struct ldpaa_dq *)dq);
437 	uint32_t token;
438 
439 	token = qb_attr_code_decode(&code_dqrr_tok_detect, &p[1]);
440 	if (token != newtoken)
441 		return 0;
442 
443 	/* Only now do we convert from hardware to host endianness. Also, as we
444 	 * are returning success, the user has promised not to call us again, so
445 	 * there's no risk of us converting the endianness twice... */
446 	make_le32_n(p, 16);
447 
448 	/* VDQCR "no longer busy" hook - not quite the same as DQRR, because the
449 	 * fact "VDQCR" shows busy doesn't mean that the result we're looking at
450 	 * is from the same command. Eg. we may be looking at our 10th dequeue
451 	 * result from our first VDQCR command, yet the second dequeue command
452 	 * could have been kicked off already, after seeing the 1st result. Ie.
453 	 * the result we're looking at is not necessarily proof that we can
454 	 * reset "busy".  We instead base the decision on whether the current
455 	 * result is sitting at the first 'storage' location of the busy
456 	 * command. */
457 	if (s->vdq.storage == dq) {
458 		s->vdq.storage = NULL;
459 			atomic_inc(&s->vdq.busy);
460 	}
461 	return 1;
462 }
463 
464 /********************************/
465 /* Categorising dequeue entries */
466 /********************************/
467 
468 static inline int __qbman_dq_entry_is_x(const struct ldpaa_dq *dq, uint32_t x)
469 {
470 	const uint32_t *p = qb_cl(dq);
471 	uint32_t response_verb = qb_attr_code_decode(&code_dqrr_response, p);
472 
473 	return response_verb == x;
474 }
475 
476 int qbman_dq_entry_is_DQ(const struct ldpaa_dq *dq)
477 {
478 	return __qbman_dq_entry_is_x(dq, QBMAN_DQRR_RESPONSE_DQ);
479 }
480 
481 /*********************************/
482 /* Parsing frame dequeue results */
483 /*********************************/
484 
485 /* These APIs assume qbman_dq_entry_is_DQ() is TRUE */
486 
487 uint32_t ldpaa_dq_flags(const struct ldpaa_dq *dq)
488 {
489 	const uint32_t *p = qb_cl(dq);
490 
491 	return qb_attr_code_decode(&code_dqrr_stat, p);
492 }
493 
494 const struct dpaa_fd *ldpaa_dq_fd(const struct ldpaa_dq *dq)
495 {
496 	const uint32_t *p = qb_cl(dq);
497 
498 	return (const struct dpaa_fd *)&p[8];
499 }
500 
501 /******************/
502 /* Buffer release */
503 /******************/
504 
505 /* These should be const, eventually */
506 /* static struct qb_attr_code code_release_num = QB_CODE(0, 0, 3); */
507 static struct qb_attr_code code_release_set_me = QB_CODE(0, 5, 1);
508 static struct qb_attr_code code_release_bpid = QB_CODE(0, 16, 16);
509 
510 void qbman_release_desc_clear(struct qbman_release_desc *d)
511 {
512 	uint32_t *cl;
513 
514 	memset(d, 0, sizeof(*d));
515 	cl = qb_cl(d);
516 	qb_attr_code_encode(&code_release_set_me, cl, 1);
517 }
518 
519 void qbman_release_desc_set_bpid(struct qbman_release_desc *d, uint32_t bpid)
520 {
521 	uint32_t *cl = qb_cl(d);
522 
523 	qb_attr_code_encode(&code_release_bpid, cl, bpid);
524 }
525 
526 #define RAR_IDX(rar)     ((rar) & 0x7)
527 #define RAR_VB(rar)      ((rar) & 0x80)
528 #define RAR_SUCCESS(rar) ((rar) & 0x100)
529 
530 int qbman_swp_release(struct qbman_swp *s, const struct qbman_release_desc *d,
531 		      const uint64_t *buffers, unsigned int num_buffers)
532 {
533 	uint32_t *p;
534 	const uint32_t *cl = qb_cl(d);
535 	uint32_t rar = qbman_cinh_read(&s->sys, QBMAN_CINH_SWP_RAR);
536 	debug("RAR=%08x\n", rar);
537 	if (!RAR_SUCCESS(rar))
538 		return -EBUSY;
539 	BUG_ON(!num_buffers || (num_buffers > 7));
540 	/* Start the release command */
541 	p = qbman_cena_write_start(&s->sys,
542 				   QBMAN_CENA_SWP_RCR(RAR_IDX(rar)));
543 	/* Copy the caller's buffer pointers to the command */
544 	u64_to_le32_copy(&p[2], buffers, num_buffers);
545 	lwsync();
546 	/* Set the verb byte, have to substitute in the valid-bit and the number
547 	 * of buffers. */
548 	p[0] = cl[0] | RAR_VB(rar) | num_buffers;
549 	qbman_cena_write_complete(&s->sys,
550 				  QBMAN_CENA_SWP_RCR(RAR_IDX(rar)),
551 				  p);
552 	return 0;
553 }
554 
555 /*******************/
556 /* Buffer acquires */
557 /*******************/
558 
559 /* These should be const, eventually */
560 static struct qb_attr_code code_acquire_bpid = QB_CODE(0, 16, 16);
561 static struct qb_attr_code code_acquire_num = QB_CODE(1, 0, 3);
562 static struct qb_attr_code code_acquire_r_num = QB_CODE(1, 0, 3);
563 
564 int qbman_swp_acquire(struct qbman_swp *s, uint32_t bpid, uint64_t *buffers,
565 		      unsigned int num_buffers)
566 {
567 	uint32_t *p;
568 	uint32_t verb, rslt, num;
569 
570 	BUG_ON(!num_buffers || (num_buffers > 7));
571 
572 	/* Start the management command */
573 	p = qbman_swp_mc_start(s);
574 
575 	if (!p)
576 		return -EBUSY;
577 
578 	/* Encode the caller-provided attributes */
579 	qb_attr_code_encode(&code_acquire_bpid, p, bpid);
580 	qb_attr_code_encode(&code_acquire_num, p, num_buffers);
581 
582 	/* Complete the management command */
583 	p = qbman_swp_mc_complete(s, p, p[0] | QBMAN_MC_ACQUIRE);
584 
585 	/* Decode the outcome */
586 	verb = qb_attr_code_decode(&code_generic_verb, p);
587 	rslt = qb_attr_code_decode(&code_generic_rslt, p);
588 	num = qb_attr_code_decode(&code_acquire_r_num, p);
589 	BUG_ON(verb != QBMAN_MC_ACQUIRE);
590 
591 	/* Determine success or failure */
592 	if (unlikely(rslt != QBMAN_MC_RSLT_OK)) {
593 		printf("Acquire buffers from BPID 0x%x failed, code=0x%02x\n",
594 		       bpid, rslt);
595 		return -EIO;
596 	}
597 	BUG_ON(num > num_buffers);
598 	/* Copy the acquired buffers to the caller's array */
599 	u64_from_le32_copy(buffers, &p[2], num);
600 	return (int)num;
601 }
602