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 */ 85 struct bstrap { 86 int (*fn)(void); 87 atomic_t started; 88 }; 89 static int bstrap_fn(void *bs) 90 { 91 struct bstrap *bstrap = bs; 92 int err; 93 94 atomic_inc(&bstrap->started); 95 err = bstrap->fn(); 96 if (err) 97 return err; 98 while (!kthread_should_stop()) 99 msleep(20); 100 return 0; 101 } 102 static 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(k)) 116 return -ENOMEM; 117 kthread_bind(k, cpu); 118 wake_up_process(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(&bstrap.started)) 126 msleep(20); 127 ret = kthread_stop(k); 128 if (ret) 129 return ret; 130 } 131 return 0; 132 } 133 134 struct 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; 158 159 struct 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 */ 174 static DEFINE_PER_CPU(struct hp_cpu, hp_cpus); 175 176 /* links together the hp_cpu structs, in first-come first-serve order. */ 177 static LIST_HEAD(hp_cpu_list); 178 static spinlock_t hp_lock = __SPIN_LOCK_UNLOCKED(hp_lock); 179 180 static unsigned int hp_cpu_list_length; 181 182 /* the "special" handler, that starts and terminates the test. */ 183 static struct hp_handler *special_handler; 184 static int loop_counter; 185 186 /* handlers are allocated out of this, so they're properly aligned. */ 187 static struct kmem_cache *hp_handler_slab; 188 189 /* this is the frame data */ 190 static void *__frame_ptr; 191 static u32 *frame_ptr; 192 static dma_addr_t frame_dma; 193 194 /* the main function waits on this */ 195 static DECLARE_WAIT_QUEUE_HEAD(queue); 196 197 #define HP_PER_CPU 2 198 #define HP_LOOPS 8 199 /* 80 bytes, like a small ethernet frame, and bleeds into a second cacheline */ 200 #define HP_NUM_WORDS 80 201 /* First word of the LFSR-based frame data */ 202 #define HP_FIRST_WORD 0xabbaf00d 203 204 static inline u32 do_lfsr(u32 prev) 205 { 206 return (prev >> 1) ^ (-(prev & 1u) & 0xd0000001u); 207 } 208 209 static int allocate_frame_data(void) 210 { 211 u32 lfsr = HP_FIRST_WORD; 212 int loop; 213 struct platform_device *pdev = platform_device_alloc("foobar", -1); 214 215 if (!pdev) { 216 pr_crit("platform_device_alloc() failed"); 217 return -EIO; 218 } 219 if (platform_device_add(pdev)) { 220 pr_crit("platform_device_add() failed"); 221 return -EIO; 222 } 223 __frame_ptr = kmalloc(4 * HP_NUM_WORDS, GFP_KERNEL); 224 if (!__frame_ptr) 225 return -ENOMEM; 226 227 frame_ptr = PTR_ALIGN(__frame_ptr, 64); 228 for (loop = 0; loop < HP_NUM_WORDS; loop++) { 229 frame_ptr[loop] = lfsr; 230 lfsr = do_lfsr(lfsr); 231 } 232 frame_dma = dma_map_single(&pdev->dev, frame_ptr, 4 * HP_NUM_WORDS, 233 DMA_BIDIRECTIONAL); 234 platform_device_del(pdev); 235 platform_device_put(pdev); 236 return 0; 237 } 238 239 static void deallocate_frame_data(void) 240 { 241 kfree(__frame_ptr); 242 } 243 244 static inline int process_frame_data(struct hp_handler *handler, 245 const struct qm_fd *fd) 246 { 247 u32 *p = handler->frame_ptr; 248 u32 lfsr = HP_FIRST_WORD; 249 int loop; 250 251 if (qm_fd_addr_get64(fd) != handler->addr) { 252 pr_crit("bad frame address"); 253 return -EIO; 254 } 255 for (loop = 0; loop < HP_NUM_WORDS; loop++, p++) { 256 *p ^= handler->rx_mixer; 257 if (*p != lfsr) { 258 pr_crit("corrupt frame data"); 259 return -EIO; 260 } 261 *p ^= handler->tx_mixer; 262 lfsr = do_lfsr(lfsr); 263 } 264 return 0; 265 } 266 267 static enum qman_cb_dqrr_result normal_dqrr(struct qman_portal *portal, 268 struct qman_fq *fq, 269 const struct qm_dqrr_entry *dqrr) 270 { 271 struct hp_handler *handler = (struct hp_handler *)fq; 272 273 if (process_frame_data(handler, &dqrr->fd)) { 274 WARN_ON(1); 275 goto skip; 276 } 277 if (qman_enqueue(&handler->tx, &dqrr->fd)) { 278 pr_crit("qman_enqueue() failed"); 279 WARN_ON(1); 280 } 281 skip: 282 return qman_cb_dqrr_consume; 283 } 284 285 static enum qman_cb_dqrr_result special_dqrr(struct qman_portal *portal, 286 struct qman_fq *fq, 287 const struct qm_dqrr_entry *dqrr) 288 { 289 struct hp_handler *handler = (struct hp_handler *)fq; 290 291 process_frame_data(handler, &dqrr->fd); 292 if (++loop_counter < HP_LOOPS) { 293 if (qman_enqueue(&handler->tx, &dqrr->fd)) { 294 pr_crit("qman_enqueue() failed"); 295 WARN_ON(1); 296 goto skip; 297 } 298 } else { 299 pr_info("Received final (%dth) frame\n", loop_counter); 300 wake_up(&queue); 301 } 302 skip: 303 return qman_cb_dqrr_consume; 304 } 305 306 static int create_per_cpu_handlers(void) 307 { 308 struct hp_handler *handler; 309 int loop; 310 struct hp_cpu *hp_cpu = this_cpu_ptr(&hp_cpus); 311 312 hp_cpu->processor_id = smp_processor_id(); 313 spin_lock(&hp_lock); 314 list_add_tail(&hp_cpu->node, &hp_cpu_list); 315 hp_cpu_list_length++; 316 spin_unlock(&hp_lock); 317 INIT_LIST_HEAD(&hp_cpu->handlers); 318 for (loop = 0; loop < HP_PER_CPU; loop++) { 319 handler = kmem_cache_alloc(hp_handler_slab, GFP_KERNEL); 320 if (!handler) { 321 pr_crit("kmem_cache_alloc() failed"); 322 WARN_ON(1); 323 return -EIO; 324 } 325 handler->processor_id = hp_cpu->processor_id; 326 handler->addr = frame_dma; 327 handler->frame_ptr = frame_ptr; 328 list_add_tail(&handler->node, &hp_cpu->handlers); 329 } 330 return 0; 331 } 332 333 static int destroy_per_cpu_handlers(void) 334 { 335 struct list_head *loop, *tmp; 336 struct hp_cpu *hp_cpu = this_cpu_ptr(&hp_cpus); 337 338 spin_lock(&hp_lock); 339 list_del(&hp_cpu->node); 340 spin_unlock(&hp_lock); 341 list_for_each_safe(loop, tmp, &hp_cpu->handlers) { 342 u32 flags = 0; 343 struct hp_handler *handler = list_entry(loop, struct hp_handler, 344 node); 345 if (qman_retire_fq(&handler->rx, &flags) || 346 (flags & QMAN_FQ_STATE_BLOCKOOS)) { 347 pr_crit("qman_retire_fq(rx) failed, flags: %x", flags); 348 WARN_ON(1); 349 return -EIO; 350 } 351 if (qman_oos_fq(&handler->rx)) { 352 pr_crit("qman_oos_fq(rx) failed"); 353 WARN_ON(1); 354 return -EIO; 355 } 356 qman_destroy_fq(&handler->rx); 357 qman_destroy_fq(&handler->tx); 358 qman_release_fqid(handler->fqid_rx); 359 list_del(&handler->node); 360 kmem_cache_free(hp_handler_slab, handler); 361 } 362 return 0; 363 } 364 365 static inline u8 num_cachelines(u32 offset) 366 { 367 u8 res = (offset + (L1_CACHE_BYTES - 1)) 368 / (L1_CACHE_BYTES); 369 if (res > 3) 370 return 3; 371 return res; 372 } 373 #define STASH_DATA_CL \ 374 num_cachelines(HP_NUM_WORDS * 4) 375 #define STASH_CTX_CL \ 376 num_cachelines(offsetof(struct hp_handler, fqid_rx)) 377 378 static int init_handler(void *h) 379 { 380 struct qm_mcc_initfq opts; 381 struct hp_handler *handler = h; 382 int err; 383 384 if (handler->processor_id != smp_processor_id()) { 385 err = -EIO; 386 goto failed; 387 } 388 /* Set up rx */ 389 memset(&handler->rx, 0, sizeof(handler->rx)); 390 if (handler == special_handler) 391 handler->rx.cb.dqrr = special_dqrr; 392 else 393 handler->rx.cb.dqrr = normal_dqrr; 394 err = qman_create_fq(handler->fqid_rx, 0, &handler->rx); 395 if (err) { 396 pr_crit("qman_create_fq(rx) failed"); 397 goto failed; 398 } 399 memset(&opts, 0, sizeof(opts)); 400 opts.we_mask = QM_INITFQ_WE_FQCTRL | QM_INITFQ_WE_CONTEXTA; 401 opts.fqd.fq_ctrl = QM_FQCTRL_CTXASTASHING; 402 qm_fqd_set_stashing(&opts.fqd, 0, STASH_DATA_CL, STASH_CTX_CL); 403 err = qman_init_fq(&handler->rx, QMAN_INITFQ_FLAG_SCHED | 404 QMAN_INITFQ_FLAG_LOCAL, &opts); 405 if (err) { 406 pr_crit("qman_init_fq(rx) failed"); 407 goto failed; 408 } 409 /* Set up tx */ 410 memset(&handler->tx, 0, sizeof(handler->tx)); 411 err = qman_create_fq(handler->fqid_tx, QMAN_FQ_FLAG_NO_MODIFY, 412 &handler->tx); 413 if (err) { 414 pr_crit("qman_create_fq(tx) failed"); 415 goto failed; 416 } 417 418 return 0; 419 failed: 420 return err; 421 } 422 423 static void init_handler_cb(void *h) 424 { 425 if (init_handler(h)) 426 WARN_ON(1); 427 } 428 429 static int init_phase2(void) 430 { 431 int loop; 432 u32 fqid = 0; 433 u32 lfsr = 0xdeadbeef; 434 struct hp_cpu *hp_cpu; 435 struct hp_handler *handler; 436 437 for (loop = 0; loop < HP_PER_CPU; loop++) { 438 list_for_each_entry(hp_cpu, &hp_cpu_list, node) { 439 int err; 440 441 if (!loop) 442 hp_cpu->iterator = list_first_entry( 443 &hp_cpu->handlers, 444 struct hp_handler, node); 445 else 446 hp_cpu->iterator = list_entry( 447 hp_cpu->iterator->node.next, 448 struct hp_handler, node); 449 /* Rx FQID is the previous handler's Tx FQID */ 450 hp_cpu->iterator->fqid_rx = fqid; 451 /* Allocate new FQID for Tx */ 452 err = qman_alloc_fqid(&fqid); 453 if (err) { 454 pr_crit("qman_alloc_fqid() failed"); 455 return err; 456 } 457 hp_cpu->iterator->fqid_tx = fqid; 458 /* Rx mixer is the previous handler's Tx mixer */ 459 hp_cpu->iterator->rx_mixer = lfsr; 460 /* Get new mixer for Tx */ 461 lfsr = do_lfsr(lfsr); 462 hp_cpu->iterator->tx_mixer = lfsr; 463 } 464 } 465 /* Fix up the first handler (fqid_rx==0, rx_mixer=0xdeadbeef) */ 466 hp_cpu = list_first_entry(&hp_cpu_list, struct hp_cpu, node); 467 handler = list_first_entry(&hp_cpu->handlers, struct hp_handler, node); 468 if (handler->fqid_rx != 0 || handler->rx_mixer != 0xdeadbeef) 469 return 1; 470 handler->fqid_rx = fqid; 471 handler->rx_mixer = lfsr; 472 /* and tag it as our "special" handler */ 473 special_handler = handler; 474 return 0; 475 } 476 477 static int init_phase3(void) 478 { 479 int loop, err; 480 struct hp_cpu *hp_cpu; 481 482 for (loop = 0; loop < HP_PER_CPU; loop++) { 483 list_for_each_entry(hp_cpu, &hp_cpu_list, node) { 484 if (!loop) 485 hp_cpu->iterator = list_first_entry( 486 &hp_cpu->handlers, 487 struct hp_handler, node); 488 else 489 hp_cpu->iterator = list_entry( 490 hp_cpu->iterator->node.next, 491 struct hp_handler, node); 492 preempt_disable(); 493 if (hp_cpu->processor_id == smp_processor_id()) { 494 err = init_handler(hp_cpu->iterator); 495 if (err) 496 return err; 497 } else { 498 smp_call_function_single(hp_cpu->processor_id, 499 init_handler_cb, hp_cpu->iterator, 1); 500 } 501 preempt_enable(); 502 } 503 } 504 return 0; 505 } 506 507 static int send_first_frame(void *ignore) 508 { 509 u32 *p = special_handler->frame_ptr; 510 u32 lfsr = HP_FIRST_WORD; 511 int loop, err; 512 struct qm_fd fd; 513 514 if (special_handler->processor_id != smp_processor_id()) { 515 err = -EIO; 516 goto failed; 517 } 518 memset(&fd, 0, sizeof(fd)); 519 qm_fd_addr_set64(&fd, special_handler->addr); 520 qm_fd_set_contig_big(&fd, HP_NUM_WORDS * 4); 521 for (loop = 0; loop < HP_NUM_WORDS; loop++, p++) { 522 if (*p != lfsr) { 523 err = -EIO; 524 pr_crit("corrupt frame data"); 525 goto failed; 526 } 527 *p ^= special_handler->tx_mixer; 528 lfsr = do_lfsr(lfsr); 529 } 530 pr_info("Sending first frame\n"); 531 err = qman_enqueue(&special_handler->tx, &fd); 532 if (err) { 533 pr_crit("qman_enqueue() failed"); 534 goto failed; 535 } 536 537 return 0; 538 failed: 539 return err; 540 } 541 542 static void send_first_frame_cb(void *ignore) 543 { 544 if (send_first_frame(NULL)) 545 WARN_ON(1); 546 } 547 548 int qman_test_stash(void) 549 { 550 int err; 551 552 if (cpumask_weight(cpu_online_mask) < 2) { 553 pr_info("%s(): skip - only 1 CPU\n", __func__); 554 return 0; 555 } 556 557 pr_info("%s(): Starting\n", __func__); 558 559 hp_cpu_list_length = 0; 560 loop_counter = 0; 561 hp_handler_slab = kmem_cache_create("hp_handler_slab", 562 sizeof(struct hp_handler), L1_CACHE_BYTES, 563 SLAB_HWCACHE_ALIGN, NULL); 564 if (!hp_handler_slab) { 565 err = -EIO; 566 pr_crit("kmem_cache_create() failed"); 567 goto failed; 568 } 569 570 err = allocate_frame_data(); 571 if (err) 572 goto failed; 573 574 /* Init phase 1 */ 575 pr_info("Creating %d handlers per cpu...\n", HP_PER_CPU); 576 if (on_all_cpus(create_per_cpu_handlers)) { 577 err = -EIO; 578 pr_crit("on_each_cpu() failed"); 579 goto failed; 580 } 581 pr_info("Number of cpus: %d, total of %d handlers\n", 582 hp_cpu_list_length, hp_cpu_list_length * HP_PER_CPU); 583 584 err = init_phase2(); 585 if (err) 586 goto failed; 587 588 err = init_phase3(); 589 if (err) 590 goto failed; 591 592 preempt_disable(); 593 if (special_handler->processor_id == smp_processor_id()) { 594 err = send_first_frame(NULL); 595 if (err) 596 goto failed; 597 } else { 598 smp_call_function_single(special_handler->processor_id, 599 send_first_frame_cb, NULL, 1); 600 } 601 preempt_enable(); 602 603 wait_event(queue, loop_counter == HP_LOOPS); 604 deallocate_frame_data(); 605 if (on_all_cpus(destroy_per_cpu_handlers)) { 606 err = -EIO; 607 pr_crit("on_each_cpu() failed"); 608 goto failed; 609 } 610 kmem_cache_destroy(hp_handler_slab); 611 pr_info("%s(): Finished\n", __func__); 612 613 return 0; 614 failed: 615 WARN_ON(1); 616 return err; 617 } 618