1/* Copyright 2009 - 2016 Freescale Semiconductor, Inc.
2 *
3 * Redistribution and use in source and binary forms, with or without
4 * modification, are permitted provided that the following conditions are met:
5 * * Redistributions of source code must retain the above copyright
6 * notice, this list of conditions and the following disclaimer.
7 * * Redistributions in binary form must reproduce the above copyright
8 * notice, this list of conditions and the following disclaimer in the
9 * documentation and/or other materials provided with the distribution.
10 * * Neither the name of Freescale Semiconductor nor the
11 * names of its contributors may be used to endorse or promote products
12 * derived from this software without specific prior written permission.
13 *
14 * ALTERNATIVELY, this software may be distributed under the terms of the
15 * GNU General Public License ("GPL") as published by the Free Software
16 * Foundation, either version 2 of that License or (at your option) any
17 * later version.
18 *
19 * THIS SOFTWARE IS PROVIDED BY Freescale Semiconductor ``AS IS'' AND ANY
20 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
21 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22 * DISCLAIMED. IN NO EVENT SHALL Freescale Semiconductor BE LIABLE FOR ANY
23 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
26 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31#include "qman_test.h"
32
33#include <linux/dma-mapping.h>
34#include <linux/delay.h>
35
36/*
37 * Algorithm:
38 *
39 * Each cpu will have HP_PER_CPU "handlers" set up, each of which incorporates
40 * an rx/tx pair of FQ objects (both of which are stashed on dequeue). The
41 * organisation of FQIDs is such that the HP_PER_CPU*NUM_CPUS handlers will
42 * shuttle a "hot potato" frame around them such that every forwarding action
43 * moves it from one cpu to another. (The use of more than one handler per cpu
44 * is to allow enough handlers/FQs to truly test the significance of caching -
45 * ie. when cache-expiries are occurring.)
46 *
47 * The "hot potato" frame content will be HP_NUM_WORDS*4 bytes in size, and the
48 * first and last words of the frame data will undergo a transformation step on
49 * each forwarding action. To achieve this, each handler will be assigned a
50 * 32-bit "mixer", that is produced using a 32-bit LFSR. When a frame is
51 * received by a handler, the mixer of the expected sender is XOR'd into all
52 * words of the entire frame, which is then validated against the original
53 * values. Then, before forwarding, the entire frame is XOR'd with the mixer of
54 * the current handler. Apart from validating that the frame is taking the
55 * expected path, this also provides some quasi-realistic overheads to each
56 * forwarding action - dereferencing *all* the frame data, computation, and
57 * conditional branching. There is a "special" handler designated to act as the
58 * instigator of the test by creating an enqueuing the "hot potato" frame, and
59 * to determine when the test has completed by counting HP_LOOPS iterations.
60 *
61 * Init phases:
62 *
63 * 1. prepare each cpu's 'hp_cpu' struct using on_each_cpu(,,1) and link them
64 * into 'hp_cpu_list'. Specifically, set processor_id, allocate HP_PER_CPU
65 * handlers and link-list them (but do no other handler setup).
66 *
67 * 2. scan over 'hp_cpu_list' HP_PER_CPU times, the first time sets each
68 * hp_cpu's 'iterator' to point to its first handler. With each loop,
69 * allocate rx/tx FQIDs and mixer values to the hp_cpu's iterator handler
70 * and advance the iterator for the next loop. This includes a final fixup,
71 * which connects the last handler to the first (and which is why phase 2
72 * and 3 are separate).
73 *
74 * 3. scan over 'hp_cpu_list' HP_PER_CPU times, the first time sets each
75 * hp_cpu's 'iterator' to point to its first handler. With each loop,
76 * initialise FQ objects and advance the iterator for the next loop.
77 * Moreover, do this initialisation on the cpu it applies to so that Rx FQ
78 * initialisation targets the correct cpu.
79 */
80
81/*
82 * helper to run something on all cpus (can't use on_each_cpu(), as that invokes
83 * the fn from irq context, which is too restrictive).
84 */
85struct bstrap {
86 int (*fn)(void);
87 atomic_t started;
88};
89static int bstrap_fn(void *bs)
90{
91 struct bstrap *bstrap = bs;
92 int err;
93
94 atomic_inc(v: &bstrap->started);
95 err = bstrap->fn();
96 if (err)
97 return err;
98 while (!kthread_should_stop())
99 msleep(msecs: 20);
100 return 0;
101}
102static int on_all_cpus(int (*fn)(void))
103{
104 int cpu;
105
106 for_each_cpu(cpu, cpu_online_mask) {
107 struct bstrap bstrap = {
108 .fn = fn,
109 .started = ATOMIC_INIT(0)
110 };
111 struct task_struct *k = kthread_create(bstrap_fn, &bstrap,
112 "hotpotato%d", cpu);
113 int ret;
114
115 if (IS_ERR(ptr: k))
116 return -ENOMEM;
117 kthread_bind(k, cpu);
118 wake_up_process(tsk: k);
119 /*
120 * If we call kthread_stop() before the "wake up" has had an
121 * effect, then the thread may exit with -EINTR without ever
122 * running the function. So poll until it's started before
123 * requesting it to stop.
124 */
125 while (!atomic_read(v: &bstrap.started))
126 msleep(msecs: 20);
127 ret = kthread_stop(k);
128 if (ret)
129 return ret;
130 }
131 return 0;
132}
133
134struct hp_handler {
135
136 /* The following data is stashed when 'rx' is dequeued; */
137 /* -------------- */
138 /* The Rx FQ, dequeues of which will stash the entire hp_handler */
139 struct qman_fq rx;
140 /* The Tx FQ we should forward to */
141 struct qman_fq tx;
142 /* The value we XOR post-dequeue, prior to validating */
143 u32 rx_mixer;
144 /* The value we XOR pre-enqueue, after validating */
145 u32 tx_mixer;
146 /* what the hotpotato address should be on dequeue */
147 dma_addr_t addr;
148 u32 *frame_ptr;
149
150 /* The following data isn't (necessarily) stashed on dequeue; */
151 /* -------------- */
152 u32 fqid_rx, fqid_tx;
153 /* list node for linking us into 'hp_cpu' */
154 struct list_head node;
155 /* Just to check ... */
156 unsigned int processor_id;
157} ____cacheline_aligned;
158
159struct hp_cpu {
160 /* identify the cpu we run on; */
161 unsigned int processor_id;
162 /* root node for the per-cpu list of handlers */
163 struct list_head handlers;
164 /* list node for linking us into 'hp_cpu_list' */
165 struct list_head node;
166 /*
167 * when repeatedly scanning 'hp_list', each time linking the n'th
168 * handlers together, this is used as per-cpu iterator state
169 */
170 struct hp_handler *iterator;
171};
172
173/* Each cpu has one of these */
174static DEFINE_PER_CPU(struct hp_cpu, hp_cpus);
175
176/* links together the hp_cpu structs, in first-come first-serve order. */
177static LIST_HEAD(hp_cpu_list);
178static DEFINE_SPINLOCK(hp_lock);
179
180static unsigned int hp_cpu_list_length;
181
182/* the "special" handler, that starts and terminates the test. */
183static struct hp_handler *special_handler;
184static int loop_counter;
185
186/* handlers are allocated out of this, so they're properly aligned. */
187static struct kmem_cache *hp_handler_slab;
188
189/* this is the frame data */
190static void *__frame_ptr;
191static u32 *frame_ptr;
192static dma_addr_t frame_dma;
193
194/* needed for dma_map*() */
195static const struct qm_portal_config *pcfg;
196
197/* the main function waits on this */
198static DECLARE_WAIT_QUEUE_HEAD(queue);
199
200#define HP_PER_CPU 2
201#define HP_LOOPS 8
202/* 80 bytes, like a small ethernet frame, and bleeds into a second cacheline */
203#define HP_NUM_WORDS 80
204/* First word of the LFSR-based frame data */
205#define HP_FIRST_WORD 0xabbaf00d
206
207static inline u32 do_lfsr(u32 prev)
208{
209 return (prev >> 1) ^ (-(prev & 1u) & 0xd0000001u);
210}
211
212static int allocate_frame_data(void)
213{
214 u32 lfsr = HP_FIRST_WORD;
215 int loop;
216
217 if (!qman_dma_portal) {
218 pr_crit("portal not available\n");
219 return -EIO;
220 }
221
222 pcfg = qman_get_qm_portal_config(portal: qman_dma_portal);
223
224 __frame_ptr = kmalloc(size: 4 * HP_NUM_WORDS, GFP_KERNEL);
225 if (!__frame_ptr)
226 return -ENOMEM;
227
228 frame_ptr = PTR_ALIGN(__frame_ptr, 64);
229 for (loop = 0; loop < HP_NUM_WORDS; loop++) {
230 frame_ptr[loop] = lfsr;
231 lfsr = do_lfsr(prev: lfsr);
232 }
233
234 frame_dma = dma_map_single(pcfg->dev, frame_ptr, 4 * HP_NUM_WORDS,
235 DMA_BIDIRECTIONAL);
236 if (dma_mapping_error(dev: pcfg->dev, dma_addr: frame_dma)) {
237 pr_crit("dma mapping failure\n");
238 kfree(objp: __frame_ptr);
239 return -EIO;
240 }
241
242 return 0;
243}
244
245static void deallocate_frame_data(void)
246{
247 dma_unmap_single(pcfg->dev, frame_dma, 4 * HP_NUM_WORDS,
248 DMA_BIDIRECTIONAL);
249 kfree(objp: __frame_ptr);
250}
251
252static inline int process_frame_data(struct hp_handler *handler,
253 const struct qm_fd *fd)
254{
255 u32 *p = handler->frame_ptr;
256 u32 lfsr = HP_FIRST_WORD;
257 int loop;
258
259 if (qm_fd_addr_get64(fd) != handler->addr) {
260 pr_crit("bad frame address, [%llX != %llX]\n",
261 qm_fd_addr_get64(fd), handler->addr);
262 return -EIO;
263 }
264 for (loop = 0; loop < HP_NUM_WORDS; loop++, p++) {
265 *p ^= handler->rx_mixer;
266 if (*p != lfsr) {
267 pr_crit("corrupt frame data");
268 return -EIO;
269 }
270 *p ^= handler->tx_mixer;
271 lfsr = do_lfsr(prev: lfsr);
272 }
273 return 0;
274}
275
276static enum qman_cb_dqrr_result normal_dqrr(struct qman_portal *portal,
277 struct qman_fq *fq,
278 const struct qm_dqrr_entry *dqrr,
279 bool sched_napi)
280{
281 struct hp_handler *handler = (struct hp_handler *)fq;
282
283 if (process_frame_data(handler, fd: &dqrr->fd)) {
284 WARN_ON(1);
285 goto skip;
286 }
287 if (qman_enqueue(fq: &handler->tx, fd: &dqrr->fd)) {
288 pr_crit("qman_enqueue() failed");
289 WARN_ON(1);
290 }
291skip:
292 return qman_cb_dqrr_consume;
293}
294
295static enum qman_cb_dqrr_result special_dqrr(struct qman_portal *portal,
296 struct qman_fq *fq,
297 const struct qm_dqrr_entry *dqrr,
298 bool sched_napi)
299{
300 struct hp_handler *handler = (struct hp_handler *)fq;
301
302 process_frame_data(handler, fd: &dqrr->fd);
303 if (++loop_counter < HP_LOOPS) {
304 if (qman_enqueue(fq: &handler->tx, fd: &dqrr->fd)) {
305 pr_crit("qman_enqueue() failed");
306 WARN_ON(1);
307 goto skip;
308 }
309 } else {
310 pr_info("Received final (%dth) frame\n", loop_counter);
311 wake_up(&queue);
312 }
313skip:
314 return qman_cb_dqrr_consume;
315}
316
317static int create_per_cpu_handlers(void)
318{
319 struct hp_handler *handler;
320 int loop;
321 struct hp_cpu *hp_cpu = this_cpu_ptr(&hp_cpus);
322
323 hp_cpu->processor_id = smp_processor_id();
324 spin_lock(lock: &hp_lock);
325 list_add_tail(new: &hp_cpu->node, head: &hp_cpu_list);
326 hp_cpu_list_length++;
327 spin_unlock(lock: &hp_lock);
328 INIT_LIST_HEAD(list: &hp_cpu->handlers);
329 for (loop = 0; loop < HP_PER_CPU; loop++) {
330 handler = kmem_cache_alloc(cachep: hp_handler_slab, GFP_KERNEL);
331 if (!handler) {
332 pr_crit("kmem_cache_alloc() failed");
333 WARN_ON(1);
334 return -EIO;
335 }
336 handler->processor_id = hp_cpu->processor_id;
337 handler->addr = frame_dma;
338 handler->frame_ptr = frame_ptr;
339 list_add_tail(new: &handler->node, head: &hp_cpu->handlers);
340 }
341 return 0;
342}
343
344static int destroy_per_cpu_handlers(void)
345{
346 struct list_head *loop, *tmp;
347 struct hp_cpu *hp_cpu = this_cpu_ptr(&hp_cpus);
348
349 spin_lock(lock: &hp_lock);
350 list_del(entry: &hp_cpu->node);
351 spin_unlock(lock: &hp_lock);
352 list_for_each_safe(loop, tmp, &hp_cpu->handlers) {
353 u32 flags = 0;
354 struct hp_handler *handler = list_entry(loop, struct hp_handler,
355 node);
356 if (qman_retire_fq(fq: &handler->rx, flags: &flags) ||
357 (flags & QMAN_FQ_STATE_BLOCKOOS)) {
358 pr_crit("qman_retire_fq(rx) failed, flags: %x", flags);
359 WARN_ON(1);
360 return -EIO;
361 }
362 if (qman_oos_fq(fq: &handler->rx)) {
363 pr_crit("qman_oos_fq(rx) failed");
364 WARN_ON(1);
365 return -EIO;
366 }
367 qman_destroy_fq(fq: &handler->rx);
368 qman_destroy_fq(fq: &handler->tx);
369 qman_release_fqid(fqid: handler->fqid_rx);
370 list_del(entry: &handler->node);
371 kmem_cache_free(s: hp_handler_slab, objp: handler);
372 }
373 return 0;
374}
375
376static inline u8 num_cachelines(u32 offset)
377{
378 u8 res = (offset + (L1_CACHE_BYTES - 1))
379 / (L1_CACHE_BYTES);
380 if (res > 3)
381 return 3;
382 return res;
383}
384#define STASH_DATA_CL \
385 num_cachelines(HP_NUM_WORDS * 4)
386#define STASH_CTX_CL \
387 num_cachelines(offsetof(struct hp_handler, fqid_rx))
388
389static int init_handler(void *h)
390{
391 struct qm_mcc_initfq opts;
392 struct hp_handler *handler = h;
393 int err;
394
395 if (handler->processor_id != smp_processor_id()) {
396 err = -EIO;
397 goto failed;
398 }
399 /* Set up rx */
400 memset(&handler->rx, 0, sizeof(handler->rx));
401 if (handler == special_handler)
402 handler->rx.cb.dqrr = special_dqrr;
403 else
404 handler->rx.cb.dqrr = normal_dqrr;
405 err = qman_create_fq(fqid: handler->fqid_rx, flags: 0, fq: &handler->rx);
406 if (err) {
407 pr_crit("qman_create_fq(rx) failed");
408 goto failed;
409 }
410 memset(&opts, 0, sizeof(opts));
411 opts.we_mask = cpu_to_be16(QM_INITFQ_WE_FQCTRL |
412 QM_INITFQ_WE_CONTEXTA);
413 opts.fqd.fq_ctrl = cpu_to_be16(QM_FQCTRL_CTXASTASHING);
414 qm_fqd_set_stashing(fqd: &opts.fqd, as: 0, STASH_DATA_CL, STASH_CTX_CL);
415 err = qman_init_fq(fq: &handler->rx, QMAN_INITFQ_FLAG_SCHED |
416 QMAN_INITFQ_FLAG_LOCAL, opts: &opts);
417 if (err) {
418 pr_crit("qman_init_fq(rx) failed");
419 goto failed;
420 }
421 /* Set up tx */
422 memset(&handler->tx, 0, sizeof(handler->tx));
423 err = qman_create_fq(fqid: handler->fqid_tx, QMAN_FQ_FLAG_NO_MODIFY,
424 fq: &handler->tx);
425 if (err) {
426 pr_crit("qman_create_fq(tx) failed");
427 goto failed;
428 }
429
430 return 0;
431failed:
432 return err;
433}
434
435static void init_handler_cb(void *h)
436{
437 if (init_handler(h))
438 WARN_ON(1);
439}
440
441static int init_phase2(void)
442{
443 int loop;
444 u32 fqid = 0;
445 u32 lfsr = 0xdeadbeef;
446 struct hp_cpu *hp_cpu;
447 struct hp_handler *handler;
448
449 for (loop = 0; loop < HP_PER_CPU; loop++) {
450 list_for_each_entry(hp_cpu, &hp_cpu_list, node) {
451 int err;
452
453 if (!loop)
454 hp_cpu->iterator = list_first_entry(
455 &hp_cpu->handlers,
456 struct hp_handler, node);
457 else
458 hp_cpu->iterator = list_entry(
459 hp_cpu->iterator->node.next,
460 struct hp_handler, node);
461 /* Rx FQID is the previous handler's Tx FQID */
462 hp_cpu->iterator->fqid_rx = fqid;
463 /* Allocate new FQID for Tx */
464 err = qman_alloc_fqid(&fqid);
465 if (err) {
466 pr_crit("qman_alloc_fqid() failed");
467 return err;
468 }
469 hp_cpu->iterator->fqid_tx = fqid;
470 /* Rx mixer is the previous handler's Tx mixer */
471 hp_cpu->iterator->rx_mixer = lfsr;
472 /* Get new mixer for Tx */
473 lfsr = do_lfsr(prev: lfsr);
474 hp_cpu->iterator->tx_mixer = lfsr;
475 }
476 }
477 /* Fix up the first handler (fqid_rx==0, rx_mixer=0xdeadbeef) */
478 hp_cpu = list_first_entry(&hp_cpu_list, struct hp_cpu, node);
479 handler = list_first_entry(&hp_cpu->handlers, struct hp_handler, node);
480 if (handler->fqid_rx != 0 || handler->rx_mixer != 0xdeadbeef)
481 return 1;
482 handler->fqid_rx = fqid;
483 handler->rx_mixer = lfsr;
484 /* and tag it as our "special" handler */
485 special_handler = handler;
486 return 0;
487}
488
489static int init_phase3(void)
490{
491 int loop, err;
492 struct hp_cpu *hp_cpu;
493
494 for (loop = 0; loop < HP_PER_CPU; loop++) {
495 list_for_each_entry(hp_cpu, &hp_cpu_list, node) {
496 if (!loop)
497 hp_cpu->iterator = list_first_entry(
498 &hp_cpu->handlers,
499 struct hp_handler, node);
500 else
501 hp_cpu->iterator = list_entry(
502 hp_cpu->iterator->node.next,
503 struct hp_handler, node);
504 preempt_disable();
505 if (hp_cpu->processor_id == smp_processor_id()) {
506 err = init_handler(h: hp_cpu->iterator);
507 if (err)
508 return err;
509 } else {
510 smp_call_function_single(cpuid: hp_cpu->processor_id,
511 func: init_handler_cb, info: hp_cpu->iterator, wait: 1);
512 }
513 preempt_enable();
514 }
515 }
516 return 0;
517}
518
519static int send_first_frame(void *ignore)
520{
521 u32 *p = special_handler->frame_ptr;
522 u32 lfsr = HP_FIRST_WORD;
523 int loop, err;
524 struct qm_fd fd;
525
526 if (special_handler->processor_id != smp_processor_id()) {
527 err = -EIO;
528 goto failed;
529 }
530 memset(&fd, 0, sizeof(fd));
531 qm_fd_addr_set64(fd: &fd, addr: special_handler->addr);
532 qm_fd_set_contig_big(&fd, HP_NUM_WORDS * 4);
533 for (loop = 0; loop < HP_NUM_WORDS; loop++, p++) {
534 if (*p != lfsr) {
535 err = -EIO;
536 pr_crit("corrupt frame data");
537 goto failed;
538 }
539 *p ^= special_handler->tx_mixer;
540 lfsr = do_lfsr(prev: lfsr);
541 }
542 pr_info("Sending first frame\n");
543 err = qman_enqueue(fq: &special_handler->tx, fd: &fd);
544 if (err) {
545 pr_crit("qman_enqueue() failed");
546 goto failed;
547 }
548
549 return 0;
550failed:
551 return err;
552}
553
554static void send_first_frame_cb(void *ignore)
555{
556 if (send_first_frame(NULL))
557 WARN_ON(1);
558}
559
560int qman_test_stash(void)
561{
562 int err;
563
564 if (cpumask_weight(cpu_online_mask) < 2) {
565 pr_info("%s(): skip - only 1 CPU\n", __func__);
566 return 0;
567 }
568
569 pr_info("%s(): Starting\n", __func__);
570
571 hp_cpu_list_length = 0;
572 loop_counter = 0;
573 hp_handler_slab = kmem_cache_create(name: "hp_handler_slab",
574 size: sizeof(struct hp_handler), L1_CACHE_BYTES,
575 SLAB_HWCACHE_ALIGN, NULL);
576 if (!hp_handler_slab) {
577 err = -EIO;
578 pr_crit("kmem_cache_create() failed");
579 goto failed;
580 }
581
582 err = allocate_frame_data();
583 if (err)
584 goto failed;
585
586 /* Init phase 1 */
587 pr_info("Creating %d handlers per cpu...\n", HP_PER_CPU);
588 if (on_all_cpus(fn: create_per_cpu_handlers)) {
589 err = -EIO;
590 pr_crit("on_each_cpu() failed");
591 goto failed;
592 }
593 pr_info("Number of cpus: %d, total of %d handlers\n",
594 hp_cpu_list_length, hp_cpu_list_length * HP_PER_CPU);
595
596 err = init_phase2();
597 if (err)
598 goto failed;
599
600 err = init_phase3();
601 if (err)
602 goto failed;
603
604 preempt_disable();
605 if (special_handler->processor_id == smp_processor_id()) {
606 err = send_first_frame(NULL);
607 if (err)
608 goto failed;
609 } else {
610 smp_call_function_single(cpuid: special_handler->processor_id,
611 func: send_first_frame_cb, NULL, wait: 1);
612 }
613 preempt_enable();
614
615 wait_event(queue, loop_counter == HP_LOOPS);
616 deallocate_frame_data();
617 if (on_all_cpus(fn: destroy_per_cpu_handlers)) {
618 err = -EIO;
619 pr_crit("on_each_cpu() failed");
620 goto failed;
621 }
622 kmem_cache_destroy(s: hp_handler_slab);
623 pr_info("%s(): Finished\n", __func__);
624
625 return 0;
626failed:
627 WARN_ON(1);
628 return err;
629}
630

source code of linux/drivers/soc/fsl/qbman/qman_test_stash.c