drivers/mmc/card/queue.c

   1 /*
   2  *  linux/drivers/mmc/card/queue.c
   3  *
   4  *  Copyright (C) 2003 Russell King, All Rights Reserved.
   5  *  Copyright 2006-2007 Pierre Ossman
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  *
  11  */
  12 #include <linux/slab.h>
  13 #include <linux/module.h>
  14 #include <linux/blkdev.h>
  15 #include <linux/freezer.h>
  16 #include <linux/kthread.h>
  17 #include <linux/scatterlist.h>
  18 #include <linux/dma-mapping.h>
  19
  20 #include <linux/mmc/card.h>
  21 #include <linux/mmc/host.h>
  22 #include <linux/sched/rt.h>
  23 #include "queue.h"
  24
  25 #define MMC_QUEUE_BOUNCESZ      65536
  26
  27 /*
  28  * Prepare a MMC request. This just filters out odd stuff.
  29  */
  30 static int mmc_prep_request(struct request_queue *q, struct request *req)
  31 {
  32         struct mmc_queue *mq = q->queuedata;
  33
  34         /*
  35          * We only like normal block requests and discards.
  36          */
  37         if (req->cmd_type != REQ_TYPE_FS && !(req->cmd_flags & REQ_DISCARD)) {
  38                 blk_dump_rq_flags(req, "MMC bad request");
  39                 return BLKPREP_KILL;
  40         }
  41
  42         if (mq && (mmc_card_removed(mq->card) || mmc_access_rpmb(mq)))
  43                 return BLKPREP_KILL;
  44
  45         req->cmd_flags |= REQ_DONTPREP;
  46
  47         return BLKPREP_OK;
  48 }
  49
  50 static int mmc_queue_thread(void *d)
  51 {
  52         struct mmc_queue *mq = d;
  53         struct request_queue *q = mq->queue;
  54         struct sched_param scheduler_params = {0};
  55
  56         scheduler_params.sched_priority = 1;
  57
  58         sched_setscheduler(current, SCHED_FIFO, &scheduler_params);
  59
  60         current->flags |= PF_MEMALLOC;
  61
  62         down(&mq->thread_sem);
  63         do {
  64                 struct request *req = NULL;
  65                 unsigned int cmd_flags = 0;
  66
  67                 spin_lock_irq(q->queue_lock);
  68                 set_current_state(TASK_INTERRUPTIBLE);
  69                 req = blk_fetch_request(q);
  70                 mq->mqrq_cur->req = req;
  71                 spin_unlock_irq(q->queue_lock);
  72
  73                 if (req || mq->mqrq_prev->req) {
  74                         set_current_state(TASK_RUNNING);
  75                         cmd_flags = req ? req->cmd_flags : 0;
  76                         mq->issue_fn(mq, req);
  77                         cond_resched();
  78                         if (mq->flags & MMC_QUEUE_NEW_REQUEST) {
  79                                 mq->flags &= ~MMC_QUEUE_NEW_REQUEST;
  80                                 continue; /* fetch again */
  81                         }
  82
  83                         /*
  84                          * Current request becomes previous request
  85                          * and vice versa.
  86                          * In case of special requests, current request
  87                          * has been finished. Do not assign it to previous
  88                          * request.
  89                          */
  90                         if (cmd_flags & MMC_REQ_SPECIAL_MASK)
  91                                 mq->mqrq_cur->req = NULL;
  92
  93                         mq->mqrq_prev->brq.mrq.data = NULL;
  94                         mq->mqrq_prev->req = NULL;
  95                         swap(mq->mqrq_prev, mq->mqrq_cur);
  96                 } else {
  97                         if (kthread_should_stop()) {
  98                                 set_current_state(TASK_RUNNING);
  99                                 break;
 100                         }
 101                         up(&mq->thread_sem);
 102                         schedule();
 103                         down(&mq->thread_sem);
 104                 }
 105         } while (1);
 106         up(&mq->thread_sem);
 107
 108         return 0;
 109 }
 110
 111 /*
 112  * Generic MMC request handler.  This is called for any queue on a
 113  * particular host.  When the host is not busy, we look for a request
 114  * on any queue on this host, and attempt to issue it.  This may
 115  * not be the queue we were asked to process.
 116  */
 117 static void mmc_request_fn(struct request_queue *q)
 118 {
 119         struct mmc_queue *mq = q->queuedata;
 120         struct request *req;
 121         unsigned long flags;
 122         struct mmc_context_info *cntx;
 123
 124         if (!mq) {
 125                 while ((req = blk_fetch_request(q)) != NULL) {
 126                         req->cmd_flags |= REQ_QUIET;
 127                         __blk_end_request_all(req, -EIO);
 128                 }
 129                 return;
 130         }
 131
 132         cntx = &mq->card->host->context_info;
 133         if (!mq->mqrq_cur->req && mq->mqrq_prev->req) {
 134                 /*
 135                  * New MMC request arrived when MMC thread may be
 136                  * blocked on the previous request to be complete
 137                  * with no current request fetched
 138                  */
 139                 spin_lock_irqsave(&cntx->lock, flags);
 140                 if (cntx->is_waiting_last_req) {
 141                         cntx->is_new_req = true;
 142                         wake_up_interruptible(&cntx->wait);
 143                 }
 144                 spin_unlock_irqrestore(&cntx->lock, flags);
 145         } else if (!mq->mqrq_cur->req && !mq->mqrq_prev->req)
 146                 wake_up_process(mq->thread);
 147 }
 148
 149 static struct scatterlist *mmc_alloc_sg(int sg_len, int *err)
 150 {
 151         struct scatterlist *sg;
 152
 153         sg = kmalloc(sizeof(struct scatterlist)*sg_len, GFP_KERNEL);
 154         if (!sg)
 155                 *err = -ENOMEM;
 156         else {
 157                 *err = 0;
 158                 sg_init_table(sg, sg_len);
 159         }
 160
 161         return sg;
 162 }
 163
 164 static void mmc_queue_setup_discard(struct request_queue *q,
 165                                     struct mmc_card *card)
 166 {
 167         unsigned max_discard;
 168
 169         max_discard = mmc_calc_max_discard(card);
 170         if (!max_discard)
 171                 return;
 172
 173         queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
 174         blk_queue_max_discard_sectors(q, max_discard);
 175         if (card->erased_byte == 0 && !mmc_can_discard(card))
 176                 q->limits.discard_zeroes_data = 1;
 177         q->limits.discard_granularity = card->pref_erase << 9;
 178         /* granularity must not be greater than max. discard */
 179         if (card->pref_erase > max_discard)
 180                 q->limits.discard_granularity = 0;
 181         if (mmc_can_secure_erase_trim(card))
 182                 queue_flag_set_unlocked(QUEUE_FLAG_SECDISCARD, q);
 183 }
 184
 185 /**
 186  * mmc_init_queue - initialise a queue structure.
 187  * @mq: mmc queue
 188  * @card: mmc card to attach this queue
 189  * @lock: queue lock
 190  * @subname: partition subname
 191  *
 192  * Initialise a MMC card request queue.
 193  */
 194 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card,
 195                    spinlock_t *lock, const char *subname)
 196 {
 197         struct mmc_host *host = card->host;
 198         u64 limit = BLK_BOUNCE_HIGH;
 199         int ret;
 200         struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 201         struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 202
 203         if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 204                 limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT;
 205
 206         mq->card = card;
 207         mq->queue = blk_init_queue(mmc_request_fn, lock);
 208         if (!mq->queue)
 209                 return -ENOMEM;
 210
 211         mq->mqrq_cur = mqrq_cur;
 212         mq->mqrq_prev = mqrq_prev;
 213         mq->queue->queuedata = mq;
 214
 215         blk_queue_prep_rq(mq->queue, mmc_prep_request);
 216         queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue);
 217         queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue);
 218         if (mmc_can_erase(card))
 219                 mmc_queue_setup_discard(mq->queue, card);
 220
 221 #ifdef CONFIG_MMC_BLOCK_BOUNCE
 222         if (host->max_segs == 1) {
 223                 unsigned int bouncesz;
 224
 225                 bouncesz = MMC_QUEUE_BOUNCESZ;
 226
 227                 if (bouncesz > host->max_req_size)
 228                         bouncesz = host->max_req_size;
 229                 if (bouncesz > host->max_seg_size)
 230                         bouncesz = host->max_seg_size;
 231                 if (bouncesz > (host->max_blk_count * 512))
 232                         bouncesz = host->max_blk_count * 512;
 233
 234                 if (bouncesz > 512) {
 235                         mqrq_cur->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
 236                         if (!mqrq_cur->bounce_buf) {
 237                                 pr_warn("%s: unable to allocate bounce cur buffer\n",
 238                                         mmc_card_name(card));
 239                         } else {
 240                                 mqrq_prev->bounce_buf =
 241                                                 kmalloc(bouncesz, GFP_KERNEL);
 242                                 if (!mqrq_prev->bounce_buf) {
 243                                         pr_warn("%s: unable to allocate bounce prev buffer\n",
 244                                                 mmc_card_name(card));
 245                                         kfree(mqrq_cur->bounce_buf);
 246                                         mqrq_cur->bounce_buf = NULL;
 247                                 }
 248                         }
 249                 }
 250
 251                 if (mqrq_cur->bounce_buf && mqrq_prev->bounce_buf) {
 252                         blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_ANY);
 253                         blk_queue_max_hw_sectors(mq->queue, bouncesz / 512);
 254                         blk_queue_max_segments(mq->queue, bouncesz / 512);
 255                         blk_queue_max_segment_size(mq->queue, bouncesz);
 256
 257                         mqrq_cur->sg = mmc_alloc_sg(1, &ret);
 258                         if (ret)
 259                                 goto cleanup_queue;
 260
 261                         mqrq_cur->bounce_sg =
 262                                 mmc_alloc_sg(bouncesz / 512, &ret);
 263                         if (ret)
 264                                 goto cleanup_queue;
 265
 266                         mqrq_prev->sg = mmc_alloc_sg(1, &ret);
 267                         if (ret)
 268                                 goto cleanup_queue;
 269
 270                         mqrq_prev->bounce_sg =
 271                                 mmc_alloc_sg(bouncesz / 512, &ret);
 272                         if (ret)
 273                                 goto cleanup_queue;
 274                 }
 275         }
 276 #endif
 277
 278         if (!mqrq_cur->bounce_buf && !mqrq_prev->bounce_buf) {
 279                 blk_queue_bounce_limit(mq->queue, limit);
 280                 blk_queue_max_hw_sectors(mq->queue,
 281                         min(host->max_blk_count, host->max_req_size / 512));
 282                 blk_queue_max_segments(mq->queue, host->max_segs);
 283                 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
 284
 285                 mqrq_cur->sg = mmc_alloc_sg(host->max_segs, &ret);
 286                 if (ret)
 287                         goto cleanup_queue;
 288
 289
 290                 mqrq_prev->sg = mmc_alloc_sg(host->max_segs, &ret);
 291                 if (ret)
 292                         goto cleanup_queue;
 293         }
 294
 295         sema_init(&mq->thread_sem, 1);
 296
 297         mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s",
 298                 host->index, subname ? subname : "");
 299
 300         if (IS_ERR(mq->thread)) {
 301                 ret = PTR_ERR(mq->thread);
 302                 goto free_bounce_sg;
 303         }
 304
 305         return 0;
 306  free_bounce_sg:
 307         kfree(mqrq_cur->bounce_sg);
 308         mqrq_cur->bounce_sg = NULL;
 309         kfree(mqrq_prev->bounce_sg);
 310         mqrq_prev->bounce_sg = NULL;
 311
 312  cleanup_queue:
 313         kfree(mqrq_cur->sg);
 314         mqrq_cur->sg = NULL;
 315         kfree(mqrq_cur->bounce_buf);
 316         mqrq_cur->bounce_buf = NULL;
 317
 318         kfree(mqrq_prev->sg);
 319         mqrq_prev->sg = NULL;
 320         kfree(mqrq_prev->bounce_buf);
 321         mqrq_prev->bounce_buf = NULL;
 322
 323         blk_cleanup_queue(mq->queue);
 324         return ret;
 325 }
 326
 327 void mmc_cleanup_queue(struct mmc_queue *mq)
 328 {
 329         struct request_queue *q = mq->queue;
 330         unsigned long flags;
 331         struct mmc_queue_req *mqrq_cur = mq->mqrq_cur;
 332         struct mmc_queue_req *mqrq_prev = mq->mqrq_prev;
 333
 334         /* Make sure the queue isn't suspended, as that will deadlock */
 335         mmc_queue_resume(mq);
 336
 337         /* Then terminate our worker thread */
 338         kthread_stop(mq->thread);
 339
 340         /* Empty the queue */
 341         spin_lock_irqsave(q->queue_lock, flags);
 342         q->queuedata = NULL;
 343         blk_start_queue(q);
 344         spin_unlock_irqrestore(q->queue_lock, flags);
 345
 346         kfree(mqrq_cur->bounce_sg);
 347         mqrq_cur->bounce_sg = NULL;
 348
 349         kfree(mqrq_cur->sg);
 350         mqrq_cur->sg = NULL;
 351
 352         kfree(mqrq_cur->bounce_buf);
 353         mqrq_cur->bounce_buf = NULL;
 354
 355         kfree(mqrq_prev->bounce_sg);
 356         mqrq_prev->bounce_sg = NULL;
 357
 358         kfree(mqrq_prev->sg);
 359         mqrq_prev->sg = NULL;
 360
 361         kfree(mqrq_prev->bounce_buf);
 362         mqrq_prev->bounce_buf = NULL;
 363
 364         mq->card = NULL;
 365 }
 366 EXPORT_SYMBOL(mmc_cleanup_queue);
 367
 368 int mmc_packed_init(struct mmc_queue *mq, struct mmc_card *card)
 369 {
 370         struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 371         struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 372         int ret = 0;
 373
 374
 375         mqrq_cur->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
 376         if (!mqrq_cur->packed) {
 377                 pr_warn("%s: unable to allocate packed cmd for mqrq_cur\n",
 378                         mmc_card_name(card));
 379                 ret = -ENOMEM;
 380                 goto out;
 381         }
 382
 383         mqrq_prev->packed = kzalloc(sizeof(struct mmc_packed), GFP_KERNEL);
 384         if (!mqrq_prev->packed) {
 385                 pr_warn("%s: unable to allocate packed cmd for mqrq_prev\n",
 386                         mmc_card_name(card));
 387                 kfree(mqrq_cur->packed);
 388                 mqrq_cur->packed = NULL;
 389                 ret = -ENOMEM;
 390                 goto out;
 391         }
 392
 393         INIT_LIST_HEAD(&mqrq_cur->packed->list);
 394         INIT_LIST_HEAD(&mqrq_prev->packed->list);
 395
 396 out:
 397         return ret;
 398 }
 399
 400 void mmc_packed_clean(struct mmc_queue *mq)
 401 {
 402         struct mmc_queue_req *mqrq_cur = &mq->mqrq[0];
 403         struct mmc_queue_req *mqrq_prev = &mq->mqrq[1];
 404
 405         kfree(mqrq_cur->packed);
 406         mqrq_cur->packed = NULL;
 407         kfree(mqrq_prev->packed);
 408         mqrq_prev->packed = NULL;
 409 }
 410
 411 /**
 412  * mmc_queue_suspend - suspend a MMC request queue
 413  * @mq: MMC queue to suspend
 414  *
 415  * Stop the block request queue, and wait for our thread to
 416  * complete any outstanding requests.  This ensures that we
 417  * won't suspend while a request is being processed.
 418  */
 419 void mmc_queue_suspend(struct mmc_queue *mq)
 420 {
 421         struct request_queue *q = mq->queue;
 422         unsigned long flags;
 423
 424         if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
 425                 mq->flags |= MMC_QUEUE_SUSPENDED;
 426
 427                 spin_lock_irqsave(q->queue_lock, flags);
 428                 blk_stop_queue(q);
 429                 spin_unlock_irqrestore(q->queue_lock, flags);
 430
 431                 down(&mq->thread_sem);
 432         }
 433 }
 434
 435 /**
 436  * mmc_queue_resume - resume a previously suspended MMC request queue
 437  * @mq: MMC queue to resume
 438  */
 439 void mmc_queue_resume(struct mmc_queue *mq)
 440 {
 441         struct request_queue *q = mq->queue;
 442         unsigned long flags;
 443
 444         if (mq->flags & MMC_QUEUE_SUSPENDED) {
 445                 mq->flags &= ~MMC_QUEUE_SUSPENDED;
 446
 447                 up(&mq->thread_sem);
 448
 449                 spin_lock_irqsave(q->queue_lock, flags);
 450                 blk_start_queue(q);
 451                 spin_unlock_irqrestore(q->queue_lock, flags);
 452         }
 453 }
 454
 455 static unsigned int mmc_queue_packed_map_sg(struct mmc_queue *mq,
 456                                             struct mmc_packed *packed,
 457                                             struct scatterlist *sg,
 458                                             enum mmc_packed_type cmd_type)
 459 {
 460         struct scatterlist *__sg = sg;
 461         unsigned int sg_len = 0;
 462         struct request *req;
 463
 464         if (mmc_packed_wr(cmd_type)) {
 465                 unsigned int hdr_sz = mmc_large_sector(mq->card) ? 4096 : 512;
 466                 unsigned int max_seg_sz = queue_max_segment_size(mq->queue);
 467                 unsigned int len, remain, offset = 0;
 468                 u8 *buf = (u8 *)packed->cmd_hdr;
 469
 470                 remain = hdr_sz;
 471                 do {
 472                         len = min(remain, max_seg_sz);
 473                         sg_set_buf(__sg, buf + offset, len);
 474                         offset += len;
 475                         remain -= len;
 476                         sg_unmark_end(__sg++);
 477                         sg_len++;
 478                 } while (remain);
 479         }
 480
 481         list_for_each_entry(req, &packed->list, queuelist) {
 482                 sg_len += blk_rq_map_sg(mq->queue, req, __sg);
 483                 __sg = sg + (sg_len - 1);
 484                 sg_unmark_end(__sg++);
 485         }
 486         sg_mark_end(sg + (sg_len - 1));
 487         return sg_len;
 488 }
 489
 490 /*
 491  * Prepare the sg list(s) to be handed of to the host driver
 492  */
 493 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq)
 494 {
 495         unsigned int sg_len;
 496         size_t buflen;
 497         struct scatterlist *sg;
 498         enum mmc_packed_type cmd_type;
 499         int i;
 500
 501         cmd_type = mqrq->cmd_type;
 502
 503         if (!mqrq->bounce_buf) {
 504                 if (mmc_packed_cmd(cmd_type))
 505                         return mmc_queue_packed_map_sg(mq, mqrq->packed,
 506                                                        mqrq->sg, cmd_type);
 507                 else
 508                         return blk_rq_map_sg(mq->queue, mqrq->req, mqrq->sg);
 509         }
 510
 511         BUG_ON(!mqrq->bounce_sg);
 512
 513         if (mmc_packed_cmd(cmd_type))
 514                 sg_len = mmc_queue_packed_map_sg(mq, mqrq->packed,
 515                                                  mqrq->bounce_sg, cmd_type);
 516         else
 517                 sg_len = blk_rq_map_sg(mq->queue, mqrq->req, mqrq->bounce_sg);
 518
 519         mqrq->bounce_sg_len = sg_len;
 520
 521         buflen = 0;
 522         for_each_sg(mqrq->bounce_sg, sg, sg_len, i)
 523                 buflen += sg->length;
 524
 525         sg_init_one(mqrq->sg, mqrq->bounce_buf, buflen);
 526
 527         return 1;
 528 }
 529
 530 /*
 531  * If writing, bounce the data to the buffer before the request
 532  * is sent to the host driver
 533  */
 534 void mmc_queue_bounce_pre(struct mmc_queue_req *mqrq)
 535 {
 536         if (!mqrq->bounce_buf)
 537                 return;
 538
 539         if (rq_data_dir(mqrq->req) != WRITE)
 540                 return;
 541
 542         sg_copy_to_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
 543                 mqrq->bounce_buf, mqrq->sg[0].length);
 544 }
 545
 546 /*
 547  * If reading, bounce the data from the buffer after the request
 548  * has been handled by the host driver
 549  */
 550 void mmc_queue_bounce_post(struct mmc_queue_req *mqrq)
 551 {
 552         if (!mqrq->bounce_buf)
 553                 return;
 554
 555         if (rq_data_dir(mqrq->req) != READ)
 556                 return;
 557
 558         sg_copy_from_buffer(mqrq->bounce_sg, mqrq->bounce_sg_len,
 559                 mqrq->bounce_buf, mqrq->sg[0].length);
 560 }