1 /***********************license start***************
2 * Author: Cavium Networks
3 *
4 * Contact: support@caviumnetworks.com
5 * This file is part of the OCTEON SDK
6 *
7 * Copyright (c) 2003-2008 Cavium Networks
8 *
9 * This file is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License, Version 2, as
11 * published by the Free Software Foundation.
12 *
13 * This file is distributed in the hope that it will be useful, but
14 * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
15 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
16 * NONINFRINGEMENT. See the GNU General Public License for more
17 * details.
18 *
19 * You should have received a copy of the GNU General Public License
20 * along with this file; if not, write to the Free Software
21 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
22 * or visit http://www.gnu.org/licenses/.
23 *
24 * This file may also be available under a different license from Cavium.
25 * Contact Cavium Networks for more information
26 ***********************license end**************************************/
27
28 /*
29 *
30 * Support functions for managing command queues used for
31 * various hardware blocks.
32 *
33 * The common command queue infrastructure abstracts out the
34 * software necessary for adding to Octeon's chained queue
35 * structures. These structures are used for commands to the
36 * PKO, ZIP, DFA, RAID, and DMA engine blocks. Although each
37 * hardware unit takes commands and CSRs of different types,
38 * they all use basic linked command buffers to store the
39 * pending request. In general, users of the CVMX API don't
40 * call cvmx-cmd-queue functions directly. Instead the hardware
41 * unit specific wrapper should be used. The wrappers perform
42 * unit specific validation and CSR writes to submit the
43 * commands.
44 *
45 * Even though most software will never directly interact with
46 * cvmx-cmd-queue, knowledge of its internal working can help
47 * in diagnosing performance problems and help with debugging.
48 *
49 * Command queue pointers are stored in a global named block
50 * called "cvmx_cmd_queues". Except for the PKO queues, each
51 * hardware queue is stored in its own cache line to reduce SMP
52 * contention on spin locks. The PKO queues are stored such that
53 * every 16th queue is next to each other in memory. This scheme
54 * allows for queues being in separate cache lines when there
55 * are low number of queues per port. With 16 queues per port,
56 * the first queue for each port is in the same cache area. The
57 * second queues for each port are in another area, etc. This
58 * allows software to implement very efficient lockless PKO with
59 * 16 queues per port using a minimum of cache lines per core.
60 * All queues for a given core will be isolated in the same
61 * cache area.
62 *
63 * In addition to the memory pointer layout, cvmx-cmd-queue
64 * provides an optimized fair ll/sc locking mechanism for the
65 * queues. The lock uses a "ticket / now serving" model to
66 * maintain fair order on contended locks. In addition, it uses
67 * predicted locking time to limit cache contention. When a core
68 * know it must wait in line for a lock, it spins on the
69 * internal cycle counter to completely eliminate any causes of
70 * bus traffic.
71 *
72 */
73
74 #ifndef __CVMX_CMD_QUEUE_H__
75 #define __CVMX_CMD_QUEUE_H__
76
77 #include <linux/prefetch.h>
78
79 #include "cvmx-fpa.h"
80 /**
81 * By default we disable the max depth support. Most programs
82 * don't use it and it slows down the command queue processing
83 * significantly.
84 */
85 #ifndef CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH
86 #define CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH 0
87 #endif
88
89 /**
90 * Enumeration representing all hardware blocks that use command
91 * queues. Each hardware block has up to 65536 sub identifiers for
92 * multiple command queues. Not all chips support all hardware
93 * units.
94 */
95 typedef enum {
96 CVMX_CMD_QUEUE_PKO_BASE = 0x00000,
97
98 #define CVMX_CMD_QUEUE_PKO(queue) \
99 ((cvmx_cmd_queue_id_t)(CVMX_CMD_QUEUE_PKO_BASE + (0xffff&(queue))))
100
101 CVMX_CMD_QUEUE_ZIP = 0x10000,
102 CVMX_CMD_QUEUE_DFA = 0x20000,
103 CVMX_CMD_QUEUE_RAID = 0x30000,
104 CVMX_CMD_QUEUE_DMA_BASE = 0x40000,
105
106 #define CVMX_CMD_QUEUE_DMA(queue) \
107 ((cvmx_cmd_queue_id_t)(CVMX_CMD_QUEUE_DMA_BASE + (0xffff&(queue))))
108
109 CVMX_CMD_QUEUE_END = 0x50000,
110 } cvmx_cmd_queue_id_t;
111
112 /**
113 * Command write operations can fail if the command queue needs
114 * a new buffer and the associated FPA pool is empty. It can also
115 * fail if the number of queued command words reaches the maximum
116 * set at initialization.
117 */
118 typedef enum {
119 CVMX_CMD_QUEUE_SUCCESS = 0,
120 CVMX_CMD_QUEUE_NO_MEMORY = -1,
121 CVMX_CMD_QUEUE_FULL = -2,
122 CVMX_CMD_QUEUE_INVALID_PARAM = -3,
123 CVMX_CMD_QUEUE_ALREADY_SETUP = -4,
124 } cvmx_cmd_queue_result_t;
125
126 typedef struct {
127 /* You have lock when this is your ticket */
128 uint8_t now_serving;
129 uint64_t unused1:24;
130 /* Maximum outstanding command words */
131 uint32_t max_depth;
132 /* FPA pool buffers come from */
133 uint64_t fpa_pool:3;
134 /* Top of command buffer pointer shifted 7 */
135 uint64_t base_ptr_div128:29;
136 uint64_t unused2:6;
137 /* FPA buffer size in 64bit words minus 1 */
138 uint64_t pool_size_m1:13;
139 /* Number of commands already used in buffer */
140 uint64_t index:13;
141 } __cvmx_cmd_queue_state_t;
142
143 /**
144 * This structure contains the global state of all command queues.
145 * It is stored in a bootmem named block and shared by all
146 * applications running on Octeon. Tickets are stored in a differnet
147 * cahce line that queue information to reduce the contention on the
148 * ll/sc used to get a ticket. If this is not the case, the update
149 * of queue state causes the ll/sc to fail quite often.
150 */
151 typedef struct {
152 uint64_t ticket[(CVMX_CMD_QUEUE_END >> 16) * 256];
153 __cvmx_cmd_queue_state_t state[(CVMX_CMD_QUEUE_END >> 16) * 256];
154 } __cvmx_cmd_queue_all_state_t;
155
156 /**
157 * Initialize a command queue for use. The initial FPA buffer is
158 * allocated and the hardware unit is configured to point to the
159 * new command queue.
160 *
161 * @queue_id: Hardware command queue to initialize.
162 * @max_depth: Maximum outstanding commands that can be queued.
163 * @fpa_pool: FPA pool the command queues should come from.
164 * @pool_size: Size of each buffer in the FPA pool (bytes)
165 *
166 * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
167 */
168 cvmx_cmd_queue_result_t cvmx_cmd_queue_initialize(cvmx_cmd_queue_id_t queue_id,
169 int max_depth, int fpa_pool,
170 int pool_size);
171
172 /**
173 * Shutdown a queue a free it's command buffers to the FPA. The
174 * hardware connected to the queue must be stopped before this
175 * function is called.
176 *
177 * @queue_id: Queue to shutdown
178 *
179 * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
180 */
181 cvmx_cmd_queue_result_t cvmx_cmd_queue_shutdown(cvmx_cmd_queue_id_t queue_id);
182
183 /**
184 * Return the number of command words pending in the queue. This
185 * function may be relatively slow for some hardware units.
186 *
187 * @queue_id: Hardware command queue to query
188 *
189 * Returns Number of outstanding commands
190 */
191 int cvmx_cmd_queue_length(cvmx_cmd_queue_id_t queue_id);
192
193 /**
194 * Return the command buffer to be written to. The purpose of this
195 * function is to allow CVMX routine access t othe low level buffer
196 * for initial hardware setup. User applications should not call this
197 * function directly.
198 *
199 * @queue_id: Command queue to query
200 *
201 * Returns Command buffer or NULL on failure
202 */
203 void *cvmx_cmd_queue_buffer(cvmx_cmd_queue_id_t queue_id);
204
205 /**
206 * Get the index into the state arrays for the supplied queue id.
207 *
208 * @queue_id: Queue ID to get an index for
209 *
210 * Returns Index into the state arrays
211 */
__cvmx_cmd_queue_get_index(cvmx_cmd_queue_id_t queue_id)212 static inline int __cvmx_cmd_queue_get_index(cvmx_cmd_queue_id_t queue_id)
213 {
214 /*
215 * Warning: This code currently only works with devices that
216 * have 256 queues or less. Devices with more than 16 queues
217 * are laid out in memory to allow cores quick access to
218 * every 16th queue. This reduces cache thrashing when you are
219 * running 16 queues per port to support lockless operation.
220 */
221 int unit = queue_id >> 16;
222 int q = (queue_id >> 4) & 0xf;
223 int core = queue_id & 0xf;
224 return unit * 256 + core * 16 + q;
225 }
226
227 /**
228 * Lock the supplied queue so nobody else is updating it at the same
229 * time as us.
230 *
231 * @queue_id: Queue ID to lock
232 * @qptr: Pointer to the queue's global state
233 */
__cvmx_cmd_queue_lock(cvmx_cmd_queue_id_t queue_id,__cvmx_cmd_queue_state_t * qptr)234 static inline void __cvmx_cmd_queue_lock(cvmx_cmd_queue_id_t queue_id,
235 __cvmx_cmd_queue_state_t *qptr)
236 {
237 extern __cvmx_cmd_queue_all_state_t
238 *__cvmx_cmd_queue_state_ptr;
239 int tmp;
240 int my_ticket;
241 prefetch(qptr);
242 asm volatile (
243 ".set push\n"
244 ".set noreorder\n"
245 "1:\n"
246 /* Atomic add one to ticket_ptr */
247 "ll %[my_ticket], %[ticket_ptr]\n"
248 /* and store the original value */
249 "li %[ticket], 1\n"
250 /* in my_ticket */
251 "baddu %[ticket], %[my_ticket]\n"
252 "sc %[ticket], %[ticket_ptr]\n"
253 "beqz %[ticket], 1b\n"
254 " nop\n"
255 /* Load the current now_serving ticket */
256 "lbu %[ticket], %[now_serving]\n"
257 "2:\n"
258 /* Jump out if now_serving == my_ticket */
259 "beq %[ticket], %[my_ticket], 4f\n"
260 /* Find out how many tickets are in front of me */
261 " subu %[ticket], %[my_ticket], %[ticket]\n"
262 /* Use tickets in front of me minus one to delay */
263 "subu %[ticket], 1\n"
264 /* Delay will be ((tickets in front)-1)*32 loops */
265 "cins %[ticket], %[ticket], 5, 7\n"
266 "3:\n"
267 /* Loop here until our ticket might be up */
268 "bnez %[ticket], 3b\n"
269 " subu %[ticket], 1\n"
270 /* Jump back up to check out ticket again */
271 "b 2b\n"
272 /* Load the current now_serving ticket */
273 " lbu %[ticket], %[now_serving]\n"
274 "4:\n"
275 ".set pop\n" :
276 [ticket_ptr] "=m"(__cvmx_cmd_queue_state_ptr->ticket[__cvmx_cmd_queue_get_index(queue_id)]),
277 [now_serving] "=m"(qptr->now_serving), [ticket] "=r"(tmp),
278 [my_ticket] "=r"(my_ticket)
279 );
280 }
281
282 /**
283 * Unlock the queue, flushing all writes.
284 *
285 * @qptr: Queue to unlock
286 */
__cvmx_cmd_queue_unlock(__cvmx_cmd_queue_state_t * qptr)287 static inline void __cvmx_cmd_queue_unlock(__cvmx_cmd_queue_state_t *qptr)
288 {
289 qptr->now_serving++;
290 CVMX_SYNCWS;
291 }
292
293 /**
294 * Get the queue state structure for the given queue id
295 *
296 * @queue_id: Queue id to get
297 *
298 * Returns Queue structure or NULL on failure
299 */
300 static inline __cvmx_cmd_queue_state_t
__cvmx_cmd_queue_get_state(cvmx_cmd_queue_id_t queue_id)301 *__cvmx_cmd_queue_get_state(cvmx_cmd_queue_id_t queue_id)
302 {
303 extern __cvmx_cmd_queue_all_state_t
304 *__cvmx_cmd_queue_state_ptr;
305 return &__cvmx_cmd_queue_state_ptr->
306 state[__cvmx_cmd_queue_get_index(queue_id)];
307 }
308
309 /**
310 * Write an arbitrary number of command words to a command queue.
311 * This is a generic function; the fixed number of command word
312 * functions yield higher performance.
313 *
314 * @queue_id: Hardware command queue to write to
315 * @use_locking:
316 * Use internal locking to ensure exclusive access for queue
317 * updates. If you don't use this locking you must ensure
318 * exclusivity some other way. Locking is strongly recommended.
319 * @cmd_count: Number of command words to write
320 * @cmds: Array of commands to write
321 *
322 * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
323 */
cvmx_cmd_queue_write(cvmx_cmd_queue_id_t queue_id,int use_locking,int cmd_count,uint64_t * cmds)324 static inline cvmx_cmd_queue_result_t cvmx_cmd_queue_write(cvmx_cmd_queue_id_t
325 queue_id,
326 int use_locking,
327 int cmd_count,
328 uint64_t *cmds)
329 {
330 __cvmx_cmd_queue_state_t *qptr = __cvmx_cmd_queue_get_state(queue_id);
331
332 /* Make sure nobody else is updating the same queue */
333 if (likely(use_locking))
334 __cvmx_cmd_queue_lock(queue_id, qptr);
335
336 /*
337 * If a max queue length was specified then make sure we don't
338 * exceed it. If any part of the command would be below the
339 * limit we allow it.
340 */
341 if (CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH && unlikely(qptr->max_depth)) {
342 if (unlikely
343 (cvmx_cmd_queue_length(queue_id) > (int)qptr->max_depth)) {
344 if (likely(use_locking))
345 __cvmx_cmd_queue_unlock(qptr);
346 return CVMX_CMD_QUEUE_FULL;
347 }
348 }
349
350 /*
351 * Normally there is plenty of room in the current buffer for
352 * the command.
353 */
354 if (likely(qptr->index + cmd_count < qptr->pool_size_m1)) {
355 uint64_t *ptr =
356 (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
357 base_ptr_div128 << 7);
358 ptr += qptr->index;
359 qptr->index += cmd_count;
360 while (cmd_count--)
361 *ptr++ = *cmds++;
362 } else {
363 uint64_t *ptr;
364 int count;
365 /*
366 * We need a new command buffer. Fail if there isn't
367 * one available.
368 */
369 uint64_t *new_buffer =
370 (uint64_t *) cvmx_fpa_alloc(qptr->fpa_pool);
371 if (unlikely(new_buffer == NULL)) {
372 if (likely(use_locking))
373 __cvmx_cmd_queue_unlock(qptr);
374 return CVMX_CMD_QUEUE_NO_MEMORY;
375 }
376 ptr =
377 (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
378 base_ptr_div128 << 7);
379 /*
380 * Figure out how many command words will fit in this
381 * buffer. One location will be needed for the next
382 * buffer pointer.
383 */
384 count = qptr->pool_size_m1 - qptr->index;
385 ptr += qptr->index;
386 cmd_count -= count;
387 while (count--)
388 *ptr++ = *cmds++;
389 *ptr = cvmx_ptr_to_phys(new_buffer);
390 /*
391 * The current buffer is full and has a link to the
392 * next buffer. Time to write the rest of the commands
393 * into the new buffer.
394 */
395 qptr->base_ptr_div128 = *ptr >> 7;
396 qptr->index = cmd_count;
397 ptr = new_buffer;
398 while (cmd_count--)
399 *ptr++ = *cmds++;
400 }
401
402 /* All updates are complete. Release the lock and return */
403 if (likely(use_locking))
404 __cvmx_cmd_queue_unlock(qptr);
405 return CVMX_CMD_QUEUE_SUCCESS;
406 }
407
408 /**
409 * Simple function to write two command words to a command
410 * queue.
411 *
412 * @queue_id: Hardware command queue to write to
413 * @use_locking:
414 * Use internal locking to ensure exclusive access for queue
415 * updates. If you don't use this locking you must ensure
416 * exclusivity some other way. Locking is strongly recommended.
417 * @cmd1: Command
418 * @cmd2: Command
419 *
420 * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
421 */
cvmx_cmd_queue_write2(cvmx_cmd_queue_id_t queue_id,int use_locking,uint64_t cmd1,uint64_t cmd2)422 static inline cvmx_cmd_queue_result_t cvmx_cmd_queue_write2(cvmx_cmd_queue_id_t
423 queue_id,
424 int use_locking,
425 uint64_t cmd1,
426 uint64_t cmd2)
427 {
428 __cvmx_cmd_queue_state_t *qptr = __cvmx_cmd_queue_get_state(queue_id);
429
430 /* Make sure nobody else is updating the same queue */
431 if (likely(use_locking))
432 __cvmx_cmd_queue_lock(queue_id, qptr);
433
434 /*
435 * If a max queue length was specified then make sure we don't
436 * exceed it. If any part of the command would be below the
437 * limit we allow it.
438 */
439 if (CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH && unlikely(qptr->max_depth)) {
440 if (unlikely
441 (cvmx_cmd_queue_length(queue_id) > (int)qptr->max_depth)) {
442 if (likely(use_locking))
443 __cvmx_cmd_queue_unlock(qptr);
444 return CVMX_CMD_QUEUE_FULL;
445 }
446 }
447
448 /*
449 * Normally there is plenty of room in the current buffer for
450 * the command.
451 */
452 if (likely(qptr->index + 2 < qptr->pool_size_m1)) {
453 uint64_t *ptr =
454 (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
455 base_ptr_div128 << 7);
456 ptr += qptr->index;
457 qptr->index += 2;
458 ptr[0] = cmd1;
459 ptr[1] = cmd2;
460 } else {
461 uint64_t *ptr;
462 /*
463 * Figure out how many command words will fit in this
464 * buffer. One location will be needed for the next
465 * buffer pointer.
466 */
467 int count = qptr->pool_size_m1 - qptr->index;
468 /*
469 * We need a new command buffer. Fail if there isn't
470 * one available.
471 */
472 uint64_t *new_buffer =
473 (uint64_t *) cvmx_fpa_alloc(qptr->fpa_pool);
474 if (unlikely(new_buffer == NULL)) {
475 if (likely(use_locking))
476 __cvmx_cmd_queue_unlock(qptr);
477 return CVMX_CMD_QUEUE_NO_MEMORY;
478 }
479 count--;
480 ptr =
481 (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
482 base_ptr_div128 << 7);
483 ptr += qptr->index;
484 *ptr++ = cmd1;
485 if (likely(count))
486 *ptr++ = cmd2;
487 *ptr = cvmx_ptr_to_phys(new_buffer);
488 /*
489 * The current buffer is full and has a link to the
490 * next buffer. Time to write the rest of the commands
491 * into the new buffer.
492 */
493 qptr->base_ptr_div128 = *ptr >> 7;
494 qptr->index = 0;
495 if (unlikely(count == 0)) {
496 qptr->index = 1;
497 new_buffer[0] = cmd2;
498 }
499 }
500
501 /* All updates are complete. Release the lock and return */
502 if (likely(use_locking))
503 __cvmx_cmd_queue_unlock(qptr);
504 return CVMX_CMD_QUEUE_SUCCESS;
505 }
506
507 /**
508 * Simple function to write three command words to a command
509 * queue.
510 *
511 * @queue_id: Hardware command queue to write to
512 * @use_locking:
513 * Use internal locking to ensure exclusive access for queue
514 * updates. If you don't use this locking you must ensure
515 * exclusivity some other way. Locking is strongly recommended.
516 * @cmd1: Command
517 * @cmd2: Command
518 * @cmd3: Command
519 *
520 * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
521 */
cvmx_cmd_queue_write3(cvmx_cmd_queue_id_t queue_id,int use_locking,uint64_t cmd1,uint64_t cmd2,uint64_t cmd3)522 static inline cvmx_cmd_queue_result_t cvmx_cmd_queue_write3(cvmx_cmd_queue_id_t
523 queue_id,
524 int use_locking,
525 uint64_t cmd1,
526 uint64_t cmd2,
527 uint64_t cmd3)
528 {
529 __cvmx_cmd_queue_state_t *qptr = __cvmx_cmd_queue_get_state(queue_id);
530
531 /* Make sure nobody else is updating the same queue */
532 if (likely(use_locking))
533 __cvmx_cmd_queue_lock(queue_id, qptr);
534
535 /*
536 * If a max queue length was specified then make sure we don't
537 * exceed it. If any part of the command would be below the
538 * limit we allow it.
539 */
540 if (CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH && unlikely(qptr->max_depth)) {
541 if (unlikely
542 (cvmx_cmd_queue_length(queue_id) > (int)qptr->max_depth)) {
543 if (likely(use_locking))
544 __cvmx_cmd_queue_unlock(qptr);
545 return CVMX_CMD_QUEUE_FULL;
546 }
547 }
548
549 /*
550 * Normally there is plenty of room in the current buffer for
551 * the command.
552 */
553 if (likely(qptr->index + 3 < qptr->pool_size_m1)) {
554 uint64_t *ptr =
555 (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
556 base_ptr_div128 << 7);
557 ptr += qptr->index;
558 qptr->index += 3;
559 ptr[0] = cmd1;
560 ptr[1] = cmd2;
561 ptr[2] = cmd3;
562 } else {
563 uint64_t *ptr;
564 /*
565 * Figure out how many command words will fit in this
566 * buffer. One location will be needed for the next
567 * buffer pointer
568 */
569 int count = qptr->pool_size_m1 - qptr->index;
570 /*
571 * We need a new command buffer. Fail if there isn't
572 * one available
573 */
574 uint64_t *new_buffer =
575 (uint64_t *) cvmx_fpa_alloc(qptr->fpa_pool);
576 if (unlikely(new_buffer == NULL)) {
577 if (likely(use_locking))
578 __cvmx_cmd_queue_unlock(qptr);
579 return CVMX_CMD_QUEUE_NO_MEMORY;
580 }
581 count--;
582 ptr =
583 (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
584 base_ptr_div128 << 7);
585 ptr += qptr->index;
586 *ptr++ = cmd1;
587 if (count) {
588 *ptr++ = cmd2;
589 if (count > 1)
590 *ptr++ = cmd3;
591 }
592 *ptr = cvmx_ptr_to_phys(new_buffer);
593 /*
594 * The current buffer is full and has a link to the
595 * next buffer. Time to write the rest of the commands
596 * into the new buffer.
597 */
598 qptr->base_ptr_div128 = *ptr >> 7;
599 qptr->index = 0;
600 ptr = new_buffer;
601 if (count == 0) {
602 *ptr++ = cmd2;
603 qptr->index++;
604 }
605 if (count < 2) {
606 *ptr++ = cmd3;
607 qptr->index++;
608 }
609 }
610
611 /* All updates are complete. Release the lock and return */
612 if (likely(use_locking))
613 __cvmx_cmd_queue_unlock(qptr);
614 return CVMX_CMD_QUEUE_SUCCESS;
615 }
616
617 #endif /* __CVMX_CMD_QUEUE_H__ */
618