1// SPDX-License-Identifier: GPL-2.0 2/* 3 * zfcp device driver 4 * 5 * Setup and helper functions to access QDIO. 6 * 7 * Copyright IBM Corp. 2002, 2020 8 */ 9 10#define KMSG_COMPONENT "zfcp" 11#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt 12 13#include <linux/lockdep.h> 14#include <linux/slab.h> 15#include <linux/module.h> 16#include "zfcp_ext.h" 17#include "zfcp_qdio.h" 18 19static bool enable_multibuffer = true; 20module_param_named(datarouter, enable_multibuffer, bool, 0400); 21MODULE_PARM_DESC(datarouter, "Enable hardware data router support (default on)"); 22 23#define ZFCP_QDIO_REQUEST_RESCAN_MSECS (MSEC_PER_SEC * 10) 24#define ZFCP_QDIO_REQUEST_SCAN_MSECS MSEC_PER_SEC 25 26static void zfcp_qdio_handler_error(struct zfcp_qdio *qdio, char *dbftag, 27 unsigned int qdio_err) 28{ 29 struct zfcp_adapter *adapter = qdio->adapter; 30 31 dev_warn(&adapter->ccw_device->dev, "A QDIO problem occurred\n"); 32 33 if (qdio_err & QDIO_ERROR_SLSB_STATE) { 34 zfcp_qdio_siosl(adapter); 35 zfcp_erp_adapter_shutdown(adapter, 0, dbftag); 36 return; 37 } 38 zfcp_erp_adapter_reopen(adapter, 39 ZFCP_STATUS_ADAPTER_LINK_UNPLUGGED | 40 ZFCP_STATUS_COMMON_ERP_FAILED, dbftag); 41} 42 43static void zfcp_qdio_zero_sbals(struct qdio_buffer *sbal[], int first, int cnt) 44{ 45 int i, sbal_idx; 46 47 for (i = first; i < first + cnt; i++) { 48 sbal_idx = i % QDIO_MAX_BUFFERS_PER_Q; 49 memset(sbal[sbal_idx], 0, sizeof(struct qdio_buffer)); 50 } 51} 52 53/* this needs to be called prior to updating the queue fill level */ 54static inline void zfcp_qdio_account(struct zfcp_qdio *qdio) 55{ 56 unsigned long long now, span; 57 int used; 58 59 now = get_tod_clock_monotonic(); 60 span = (now - qdio->req_q_time) >> 12; 61 used = QDIO_MAX_BUFFERS_PER_Q - atomic_read(&qdio->req_q_free); 62 qdio->req_q_util += used * span; 63 qdio->req_q_time = now; 64} 65 66static void zfcp_qdio_int_req(struct ccw_device *cdev, unsigned int qdio_err, 67 int queue_no, int idx, int count, 68 unsigned long parm) 69{ 70 struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm; 71 72 zfcp_qdio_handler_error(qdio, "qdireq1", qdio_err); 73} 74 75static void zfcp_qdio_request_tasklet(struct tasklet_struct *tasklet) 76{ 77 struct zfcp_qdio *qdio = from_tasklet(qdio, tasklet, request_tasklet); 78 struct ccw_device *cdev = qdio->adapter->ccw_device; 79 unsigned int start, error; 80 int completed; 81 82 completed = qdio_inspect_output_queue(cdev, 0, &start, &error); 83 if (completed > 0) { 84 if (error) { 85 zfcp_qdio_handler_error(qdio, "qdreqt1", error); 86 } else { 87 /* cleanup all SBALs being program-owned now */ 88 zfcp_qdio_zero_sbals(qdio->req_q, start, completed); 89 90 spin_lock_irq(&qdio->stat_lock); 91 zfcp_qdio_account(qdio); 92 spin_unlock_irq(&qdio->stat_lock); 93 atomic_add(completed, &qdio->req_q_free); 94 wake_up(&qdio->req_q_wq); 95 } 96 } 97 98 if (atomic_read(&qdio->req_q_free) < QDIO_MAX_BUFFERS_PER_Q) 99 timer_reduce(&qdio->request_timer, 100 jiffies + msecs_to_jiffies(ZFCP_QDIO_REQUEST_RESCAN_MSECS)); 101} 102 103static void zfcp_qdio_request_timer(struct timer_list *timer) 104{ 105 struct zfcp_qdio *qdio = from_timer(qdio, timer, request_timer); 106 107 tasklet_schedule(&qdio->request_tasklet); 108} 109 110static void zfcp_qdio_int_resp(struct ccw_device *cdev, unsigned int qdio_err, 111 int queue_no, int idx, int count, 112 unsigned long parm) 113{ 114 struct zfcp_qdio *qdio = (struct zfcp_qdio *) parm; 115 struct zfcp_adapter *adapter = qdio->adapter; 116 int sbal_no, sbal_idx; 117 118 if (unlikely(qdio_err)) { 119 if (zfcp_adapter_multi_buffer_active(adapter)) { 120 void *pl[ZFCP_QDIO_MAX_SBALS_PER_REQ + 1]; 121 struct qdio_buffer_element *sbale; 122 u64 req_id; 123 u8 scount; 124 125 memset(pl, 0, 126 ZFCP_QDIO_MAX_SBALS_PER_REQ * sizeof(void *)); 127 sbale = qdio->res_q[idx]->element; 128 req_id = dma64_to_u64(sbale->addr); 129 scount = min(sbale->scount + 1, 130 ZFCP_QDIO_MAX_SBALS_PER_REQ + 1); 131 /* incl. signaling SBAL */ 132 133 for (sbal_no = 0; sbal_no < scount; sbal_no++) { 134 sbal_idx = (idx + sbal_no) % 135 QDIO_MAX_BUFFERS_PER_Q; 136 pl[sbal_no] = qdio->res_q[sbal_idx]; 137 } 138 zfcp_dbf_hba_def_err(adapter, req_id, scount, pl); 139 } 140 zfcp_qdio_handler_error(qdio, "qdires1", qdio_err); 141 return; 142 } 143 144 /* 145 * go through all SBALs from input queue currently 146 * returned by QDIO layer 147 */ 148 for (sbal_no = 0; sbal_no < count; sbal_no++) { 149 sbal_idx = (idx + sbal_no) % QDIO_MAX_BUFFERS_PER_Q; 150 /* go through all SBALEs of SBAL */ 151 zfcp_fsf_reqid_check(qdio, sbal_idx); 152 } 153 154 /* 155 * put SBALs back to response queue 156 */ 157 if (qdio_add_bufs_to_input_queue(cdev, 0, idx, count)) 158 zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdires2"); 159} 160 161static void zfcp_qdio_irq_tasklet(struct tasklet_struct *tasklet) 162{ 163 struct zfcp_qdio *qdio = from_tasklet(qdio, tasklet, irq_tasklet); 164 struct ccw_device *cdev = qdio->adapter->ccw_device; 165 unsigned int start, error; 166 int completed; 167 168 if (atomic_read(&qdio->req_q_free) < QDIO_MAX_BUFFERS_PER_Q) 169 tasklet_schedule(&qdio->request_tasklet); 170 171 /* Check the Response Queue: */ 172 completed = qdio_inspect_input_queue(cdev, 0, &start, &error); 173 if (completed < 0) 174 return; 175 if (completed > 0) 176 zfcp_qdio_int_resp(cdev, error, 0, start, completed, 177 (unsigned long) qdio); 178 179 if (qdio_start_irq(cdev)) 180 /* More work pending: */ 181 tasklet_schedule(&qdio->irq_tasklet); 182} 183 184static void zfcp_qdio_poll(struct ccw_device *cdev, unsigned long data) 185{ 186 struct zfcp_qdio *qdio = (struct zfcp_qdio *) data; 187 188 tasklet_schedule(&qdio->irq_tasklet); 189} 190 191static struct qdio_buffer_element * 192zfcp_qdio_sbal_chain(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 193{ 194 struct qdio_buffer_element *sbale; 195 196 /* set last entry flag in current SBALE of current SBAL */ 197 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 198 sbale->eflags |= SBAL_EFLAGS_LAST_ENTRY; 199 200 /* don't exceed last allowed SBAL */ 201 if (q_req->sbal_last == q_req->sbal_limit) 202 return NULL; 203 204 /* set chaining flag in first SBALE of current SBAL */ 205 sbale = zfcp_qdio_sbale_req(qdio, q_req); 206 sbale->sflags |= SBAL_SFLAGS0_MORE_SBALS; 207 208 /* calculate index of next SBAL */ 209 q_req->sbal_last++; 210 q_req->sbal_last %= QDIO_MAX_BUFFERS_PER_Q; 211 212 /* keep this requests number of SBALs up-to-date */ 213 q_req->sbal_number++; 214 BUG_ON(q_req->sbal_number > ZFCP_QDIO_MAX_SBALS_PER_REQ); 215 216 /* start at first SBALE of new SBAL */ 217 q_req->sbale_curr = 0; 218 219 /* set storage-block type for new SBAL */ 220 sbale = zfcp_qdio_sbale_curr(qdio, q_req); 221 sbale->sflags |= q_req->sbtype; 222 223 return sbale; 224} 225 226static struct qdio_buffer_element * 227zfcp_qdio_sbale_next(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 228{ 229 if (q_req->sbale_curr == qdio->max_sbale_per_sbal - 1) 230 return zfcp_qdio_sbal_chain(qdio, q_req); 231 q_req->sbale_curr++; 232 return zfcp_qdio_sbale_curr(qdio, q_req); 233} 234 235/** 236 * zfcp_qdio_sbals_from_sg - fill SBALs from scatter-gather list 237 * @qdio: pointer to struct zfcp_qdio 238 * @q_req: pointer to struct zfcp_qdio_req 239 * @sg: scatter-gather list 240 * Returns: zero or -EINVAL on error 241 */ 242int zfcp_qdio_sbals_from_sg(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req, 243 struct scatterlist *sg) 244{ 245 struct qdio_buffer_element *sbale; 246 247 /* set storage-block type for this request */ 248 sbale = zfcp_qdio_sbale_req(qdio, q_req); 249 sbale->sflags |= q_req->sbtype; 250 251 for (; sg; sg = sg_next(sg)) { 252 sbale = zfcp_qdio_sbale_next(qdio, q_req); 253 if (!sbale) { 254 atomic_inc(&qdio->req_q_full); 255 zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first, 256 q_req->sbal_number); 257 return -EINVAL; 258 } 259 sbale->addr = u64_to_dma64(sg_phys(sg)); 260 sbale->length = sg->length; 261 } 262 return 0; 263} 264 265static int zfcp_qdio_sbal_check(struct zfcp_qdio *qdio) 266{ 267 if (atomic_read(&qdio->req_q_free) || 268 !(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)) 269 return 1; 270 return 0; 271} 272 273/** 274 * zfcp_qdio_sbal_get - get free sbal in request queue, wait if necessary 275 * @qdio: pointer to struct zfcp_qdio 276 * 277 * The req_q_lock must be held by the caller of this function, and 278 * this function may only be called from process context; it will 279 * sleep when waiting for a free sbal. 280 * 281 * Returns: 0 on success, -EIO if there is no free sbal after waiting. 282 */ 283int zfcp_qdio_sbal_get(struct zfcp_qdio *qdio) 284{ 285 long ret; 286 287 ret = wait_event_interruptible_lock_irq_timeout(qdio->req_q_wq, 288 zfcp_qdio_sbal_check(qdio), qdio->req_q_lock, 5 * HZ); 289 290 if (!(atomic_read(&qdio->adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)) 291 return -EIO; 292 293 if (ret > 0) 294 return 0; 295 296 if (!ret) { 297 atomic_inc(&qdio->req_q_full); 298 /* assume hanging outbound queue, try queue recovery */ 299 zfcp_erp_adapter_reopen(qdio->adapter, 0, "qdsbg_1"); 300 } 301 302 return -EIO; 303} 304 305/** 306 * zfcp_qdio_send - send req to QDIO 307 * @qdio: pointer to struct zfcp_qdio 308 * @q_req: pointer to struct zfcp_qdio_req 309 * Returns: 0 on success, error otherwise 310 */ 311int zfcp_qdio_send(struct zfcp_qdio *qdio, struct zfcp_qdio_req *q_req) 312{ 313 int retval; 314 u8 sbal_number = q_req->sbal_number; 315 316 /* 317 * This should actually be a spin_lock_bh(stat_lock), to protect against 318 * Request Queue completion processing in tasklet context. 319 * But we can't do so (and are safe), as we always get called with IRQs 320 * disabled by spin_lock_irq[save](req_q_lock). 321 */ 322 lockdep_assert_irqs_disabled(); 323 spin_lock(&qdio->stat_lock); 324 zfcp_qdio_account(qdio); 325 spin_unlock(&qdio->stat_lock); 326 327 atomic_sub(sbal_number, &qdio->req_q_free); 328 329 retval = qdio_add_bufs_to_output_queue(qdio->adapter->ccw_device, 0, 330 q_req->sbal_first, sbal_number, 331 NULL); 332 333 if (unlikely(retval)) { 334 /* Failed to submit the IO, roll back our modifications. */ 335 atomic_add(sbal_number, &qdio->req_q_free); 336 zfcp_qdio_zero_sbals(qdio->req_q, q_req->sbal_first, 337 sbal_number); 338 return retval; 339 } 340 341 if (atomic_read(&qdio->req_q_free) <= 2 * ZFCP_QDIO_MAX_SBALS_PER_REQ) 342 tasklet_schedule(&qdio->request_tasklet); 343 else 344 timer_reduce(&qdio->request_timer, 345 jiffies + msecs_to_jiffies(ZFCP_QDIO_REQUEST_SCAN_MSECS)); 346 347 /* account for transferred buffers */ 348 qdio->req_q_idx += sbal_number; 349 qdio->req_q_idx %= QDIO_MAX_BUFFERS_PER_Q; 350 351 return 0; 352} 353 354/** 355 * zfcp_qdio_allocate - allocate queue memory and initialize QDIO data 356 * @qdio: pointer to struct zfcp_qdio 357 * Returns: -ENOMEM on memory allocation error or return value from 358 * qdio_allocate 359 */ 360static int zfcp_qdio_allocate(struct zfcp_qdio *qdio) 361{ 362 int ret; 363 364 ret = qdio_alloc_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q); 365 if (ret) 366 return -ENOMEM; 367 368 ret = qdio_alloc_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q); 369 if (ret) 370 goto free_req_q; 371 372 init_waitqueue_head(&qdio->req_q_wq); 373 374 ret = qdio_allocate(qdio->adapter->ccw_device, 1, 1); 375 if (ret) 376 goto free_res_q; 377 378 return 0; 379 380free_res_q: 381 qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q); 382free_req_q: 383 qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q); 384 return ret; 385} 386 387/** 388 * zfcp_qdio_close - close qdio queues for an adapter 389 * @qdio: pointer to structure zfcp_qdio 390 */ 391void zfcp_qdio_close(struct zfcp_qdio *qdio) 392{ 393 struct zfcp_adapter *adapter = qdio->adapter; 394 int idx, count; 395 396 if (!(atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP)) 397 return; 398 399 /* 400 * Clear QDIOUP flag, thus qdio_add_bufs_to_output_queue() is not called 401 * during qdio_shutdown(). 402 */ 403 spin_lock_irq(&qdio->req_q_lock); 404 atomic_andnot(ZFCP_STATUS_ADAPTER_QDIOUP, &adapter->status); 405 spin_unlock_irq(&qdio->req_q_lock); 406 407 wake_up(&qdio->req_q_wq); 408 409 tasklet_disable(&qdio->irq_tasklet); 410 tasklet_disable(&qdio->request_tasklet); 411 del_timer_sync(&qdio->request_timer); 412 qdio_stop_irq(adapter->ccw_device); 413 qdio_shutdown(adapter->ccw_device, QDIO_FLAG_CLEANUP_USING_CLEAR); 414 415 /* cleanup used outbound sbals */ 416 count = atomic_read(&qdio->req_q_free); 417 if (count < QDIO_MAX_BUFFERS_PER_Q) { 418 idx = (qdio->req_q_idx + count) % QDIO_MAX_BUFFERS_PER_Q; 419 count = QDIO_MAX_BUFFERS_PER_Q - count; 420 zfcp_qdio_zero_sbals(qdio->req_q, idx, count); 421 } 422 qdio->req_q_idx = 0; 423 atomic_set(&qdio->req_q_free, 0); 424} 425 426void zfcp_qdio_shost_update(struct zfcp_adapter *const adapter, 427 const struct zfcp_qdio *const qdio) 428{ 429 struct Scsi_Host *const shost = adapter->scsi_host; 430 431 if (shost == NULL) 432 return; 433 434 shost->sg_tablesize = qdio->max_sbale_per_req; 435 shost->max_sectors = qdio->max_sbale_per_req * 8; 436} 437 438/** 439 * zfcp_qdio_open - prepare and initialize response queue 440 * @qdio: pointer to struct zfcp_qdio 441 * Returns: 0 on success, otherwise -EIO 442 */ 443int zfcp_qdio_open(struct zfcp_qdio *qdio) 444{ 445 struct qdio_buffer **input_sbals[1] = {qdio->res_q}; 446 struct qdio_buffer **output_sbals[1] = {qdio->req_q}; 447 struct qdio_buffer_element *sbale; 448 struct qdio_initialize init_data = {0}; 449 struct zfcp_adapter *adapter = qdio->adapter; 450 struct ccw_device *cdev = adapter->ccw_device; 451 struct qdio_ssqd_desc ssqd; 452 int cc; 453 454 if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_QDIOUP) 455 return -EIO; 456 457 atomic_andnot(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED, 458 &qdio->adapter->status); 459 460 init_data.q_format = QDIO_ZFCP_QFMT; 461 init_data.qib_rflags = QIB_RFLAGS_ENABLE_DATA_DIV; 462 if (enable_multibuffer) 463 init_data.qdr_ac |= QDR_AC_MULTI_BUFFER_ENABLE; 464 init_data.no_input_qs = 1; 465 init_data.no_output_qs = 1; 466 init_data.input_handler = zfcp_qdio_int_resp; 467 init_data.output_handler = zfcp_qdio_int_req; 468 init_data.irq_poll = zfcp_qdio_poll; 469 init_data.int_parm = (unsigned long) qdio; 470 init_data.input_sbal_addr_array = input_sbals; 471 init_data.output_sbal_addr_array = output_sbals; 472 473 if (qdio_establish(cdev, &init_data)) 474 goto failed_establish; 475 476 if (qdio_get_ssqd_desc(cdev, &ssqd)) 477 goto failed_qdio; 478 479 if (ssqd.qdioac2 & CHSC_AC2_DATA_DIV_ENABLED) 480 atomic_or(ZFCP_STATUS_ADAPTER_DATA_DIV_ENABLED, 481 &qdio->adapter->status); 482 483 if (ssqd.qdioac2 & CHSC_AC2_MULTI_BUFFER_ENABLED) { 484 atomic_or(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status); 485 qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER; 486 } else { 487 atomic_andnot(ZFCP_STATUS_ADAPTER_MB_ACT, &adapter->status); 488 qdio->max_sbale_per_sbal = QDIO_MAX_ELEMENTS_PER_BUFFER - 1; 489 } 490 491 qdio->max_sbale_per_req = 492 ZFCP_QDIO_MAX_SBALS_PER_REQ * qdio->max_sbale_per_sbal 493 - 2; 494 if (qdio_activate(cdev)) 495 goto failed_qdio; 496 497 for (cc = 0; cc < QDIO_MAX_BUFFERS_PER_Q; cc++) { 498 sbale = &(qdio->res_q[cc]->element[0]); 499 sbale->length = 0; 500 sbale->eflags = SBAL_EFLAGS_LAST_ENTRY; 501 sbale->sflags = 0; 502 sbale->addr = 0; 503 } 504 505 if (qdio_add_bufs_to_input_queue(cdev, 0, 0, QDIO_MAX_BUFFERS_PER_Q)) 506 goto failed_qdio; 507 508 /* set index of first available SBALS / number of available SBALS */ 509 qdio->req_q_idx = 0; 510 atomic_set(&qdio->req_q_free, QDIO_MAX_BUFFERS_PER_Q); 511 atomic_or(ZFCP_STATUS_ADAPTER_QDIOUP, &qdio->adapter->status); 512 513 /* Enable processing for Request Queue completions: */ 514 tasklet_enable(&qdio->request_tasklet); 515 /* Enable processing for QDIO interrupts: */ 516 tasklet_enable(&qdio->irq_tasklet); 517 /* This results in a qdio_start_irq(): */ 518 tasklet_schedule(&qdio->irq_tasklet); 519 520 zfcp_qdio_shost_update(adapter, qdio); 521 522 return 0; 523 524failed_qdio: 525 qdio_shutdown(cdev, QDIO_FLAG_CLEANUP_USING_CLEAR); 526failed_establish: 527 dev_err(&cdev->dev, 528 "Setting up the QDIO connection to the FCP adapter failed\n"); 529 return -EIO; 530} 531 532void zfcp_qdio_destroy(struct zfcp_qdio *qdio) 533{ 534 if (!qdio) 535 return; 536 537 tasklet_kill(&qdio->irq_tasklet); 538 tasklet_kill(&qdio->request_tasklet); 539 540 if (qdio->adapter->ccw_device) 541 qdio_free(qdio->adapter->ccw_device); 542 543 qdio_free_buffers(qdio->req_q, QDIO_MAX_BUFFERS_PER_Q); 544 qdio_free_buffers(qdio->res_q, QDIO_MAX_BUFFERS_PER_Q); 545 kfree(qdio); 546} 547 548int zfcp_qdio_setup(struct zfcp_adapter *adapter) 549{ 550 struct zfcp_qdio *qdio; 551 552 qdio = kzalloc(sizeof(struct zfcp_qdio), GFP_KERNEL); 553 if (!qdio) 554 return -ENOMEM; 555 556 qdio->adapter = adapter; 557 558 if (zfcp_qdio_allocate(qdio)) { 559 kfree(qdio); 560 return -ENOMEM; 561 } 562 563 spin_lock_init(&qdio->req_q_lock); 564 spin_lock_init(&qdio->stat_lock); 565 timer_setup(&qdio->request_timer, zfcp_qdio_request_timer, 0); 566 tasklet_setup(&qdio->irq_tasklet, zfcp_qdio_irq_tasklet); 567 tasklet_setup(&qdio->request_tasklet, zfcp_qdio_request_tasklet); 568 tasklet_disable(&qdio->irq_tasklet); 569 tasklet_disable(&qdio->request_tasklet); 570 571 adapter->qdio = qdio; 572 return 0; 573} 574 575/** 576 * zfcp_qdio_siosl - Trigger logging in FCP channel 577 * @adapter: The zfcp_adapter where to trigger logging 578 * 579 * Call the cio siosl function to trigger hardware logging. This 580 * wrapper function sets a flag to ensure hardware logging is only 581 * triggered once before going through qdio shutdown. 582 * 583 * The triggers are always run from qdio tasklet context, so no 584 * additional synchronization is necessary. 585 */ 586void zfcp_qdio_siosl(struct zfcp_adapter *adapter) 587{ 588 int rc; 589 590 if (atomic_read(&adapter->status) & ZFCP_STATUS_ADAPTER_SIOSL_ISSUED) 591 return; 592 593 rc = ccw_device_siosl(adapter->ccw_device); 594 if (!rc) 595 atomic_or(ZFCP_STATUS_ADAPTER_SIOSL_ISSUED, 596 &adapter->status); 597} 598