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/module.h>
  13 #include <linux/blkdev.h>
  14 #if 0 // mask by Victor Yu. 12-02-2008
  15 #include <linux/freezer.h>
  16 #endif
  17 #include <linux/kthread.h>
  18
  19 #include <linux/mmc/card.h>
  20 #include <linux/mmc/host.h>
  21 #include "queue.h"
  22
  23 #define MMC_QUEUE_BOUNCESZ      65536
  24
  25 #define MMC_QUEUE_SUSPENDED     (1 << 0)
  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 #if 1   // mask by Victor Yu. 12-03-2008
  33         /*
  34          * We only like normal block requests.
  35          */
  36         if (!blk_fs_request(req) && !blk_pc_request(req)) {
  37                 blk_dump_rq_flags(req, "MMC bad request");
  38                 return BLKPREP_KILL;
  39         }
  40
  41 #if 0   // mask by Victor Yu. 12-02-2008
  42         req->cmd_flags |= REQ_DONTPREP;
  43 #else
  44         req->flags |= REQ_DONTPREP;
  45 #endif
  46
  47         return BLKPREP_OK;
  48 #else
  49         struct mmc_queue *mq = q->queuedata;
  50         int ret = BLKPREP_KILL;
  51
  52 #if 0   // mask by Victor Yu. 12-02--2008
  53         if (blk_special_request(req)) {
  54 #else
  55         if (req->flags & REQ_SPECIAL) {
  56 #endif
  57         /*
  58          * Special commands already have the command
  59          * blocks already setup in req->special.
  60          */
  61                 BUG_ON(!req->special);
  62
  63                 ret = BLKPREP_OK;
  64 #if 0   // mask by Victor Yu. 12-02--2008
  65         } else if (blk_fs_request(req) || blk_pc_request(req)) {
  66 #else
  67         } else if (req->flags & (REQ_CMD | REQ_BLOCK_PC)) {
  68 #endif
  69                 /*
  70                  * Block I/O requests need translating according
  71                  * to the protocol.
  72                  */
  73                 ret = mq->prep_fn(mq, req);
  74         } else {
  75                 /*
  76                  * Everything else is invalid.
  77                  */
  78                 blk_dump_rq_flags(req, "MMC bad request");
  79         }
  80
  81         if (ret == BLKPREP_OK) {
  82 #if 0   // mask by Victor Yu. 12-02--2008
  83                 req->cmd_flags |= REQ_DONTPREP;
  84 #else
  85                 req->flags |= REQ_DONTPREP;
  86 #endif
  87         }
  88
  89         return ret;
  90 #endif
  91 }
  92
  93 static int mmc_queue_thread(void *d)
  94 {
  95         struct mmc_queue *mq = d;
  96         struct request_queue *q = mq->queue;
  97
  98         current->flags |= PF_MEMALLOC;
  99
 100         down(&mq->thread_sem);
 101         do {
 102                 struct request *req = NULL;
 103
 104                 spin_lock_irq(q->queue_lock);
 105                 set_current_state(TASK_INTERRUPTIBLE);
 106                 if (!blk_queue_plugged(q))
 107                         req = elv_next_request(q);
 108                 mq->req = req;
 109                 spin_unlock_irq(q->queue_lock);
 110
 111                 if (!req) {
 112                         if (kthread_should_stop()) {
 113                                 set_current_state(TASK_RUNNING);
 114                                 break;
 115                         }
 116                         up(&mq->thread_sem);
 117                         schedule();
 118                         down(&mq->thread_sem);
 119                         continue;
 120                 }
 121                 set_current_state(TASK_RUNNING);
 122
 123                 mq->issue_fn(mq, req);
 124         } while (1);
 125         up(&mq->thread_sem);
 126
 127         return 0;
 128 }
 129
 130 /*
 131  * Generic MMC request handler.  This is called for any queue on a
 132  * particular host.  When the host is not busy, we look for a request
 133  * on any queue on this host, and attempt to issue it.  This may
 134  * not be the queue we were asked to process.
 135  */
 136 static void mmc_request(struct request_queue *q)
 137 {
 138         struct mmc_queue *mq = q->queuedata;
 139         struct request *req;
 140         int ret;
 141
 142         if (!mq) {
 143                 printk(KERN_ERR "MMC: killing requests for dead queue\n");
 144                 while ((req = elv_next_request(q)) != NULL) {
 145                         do {
 146                                 ret = end_that_request_chunk(req, 0,
 147                                         req->current_nr_sectors << 9);
 148                         } while (ret);
 149                 }
 150                 return;
 151         }
 152
 153         if (!mq->req)
 154                 wake_up_process(mq->thread);
 155 }
 156
 157 /**
 158  * mmc_init_queue - initialise a queue structure.
 159  * @mq: mmc queue
 160  * @card: mmc card to attach this queue
 161  * @lock: queue lock
 162  *
 163  * Initialise a MMC card request queue.
 164  */
 165 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, spinlock_t *lock)
 166 {
 167         struct mmc_host *host = card->host;
 168         u64 limit = BLK_BOUNCE_HIGH;
 169         int ret;
 170
 171         if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask)
 172                 limit = *mmc_dev(host)->dma_mask;
 173
 174         mq->card = card;
 175         mq->queue = blk_init_queue(mmc_request, lock);
 176         if (!mq->queue)
 177                 return -ENOMEM;
 178
 179         mq->queue->queuedata = mq;
 180         mq->req = NULL;
 181
 182         blk_queue_prep_rq(mq->queue, mmc_prep_request);
 183
 184 #ifdef CONFIG_MMC_BLOCK_BOUNCE
 185         if (host->max_hw_segs == 1) {
 186                 unsigned int bouncesz;
 187
 188                 bouncesz = MMC_QUEUE_BOUNCESZ;
 189
 190                 if (bouncesz > host->max_req_size)
 191                         bouncesz = host->max_req_size;
 192                 if (bouncesz > host->max_seg_size)
 193                         bouncesz = host->max_seg_size;
 194
 195                 mq->bounce_buf = kmalloc(bouncesz, GFP_KERNEL);
 196                 if (!mq->bounce_buf) {
 197                         printk(KERN_WARNING "%s: unable to allocate "
 198                                 "bounce buffer\n", mmc_card_name(card));
 199                 } else {
 200                         blk_queue_bounce_limit(mq->queue, BLK_BOUNCE_HIGH);
 201                         blk_queue_max_sectors(mq->queue, bouncesz / 512);
 202                         blk_queue_max_phys_segments(mq->queue, bouncesz / 512);
 203                         blk_queue_max_hw_segments(mq->queue, bouncesz / 512);
 204                         blk_queue_max_segment_size(mq->queue, bouncesz);
 205
 206                         mq->sg = kmalloc(sizeof(struct scatterlist),
 207                                 GFP_KERNEL);
 208                         if (!mq->sg) {
 209                                 ret = -ENOMEM;
 210                                 goto cleanup_queue;
 211                         }
 212
 213                         mq->bounce_sg = kmalloc(sizeof(struct scatterlist) *
 214                                 bouncesz / 512, GFP_KERNEL);
 215                         if (!mq->bounce_sg) {
 216                                 ret = -ENOMEM;
 217                                 goto cleanup_queue;
 218                         }
 219                 }
 220         }
 221 #endif
 222
 223         if (!mq->bounce_buf) {
 224                 blk_queue_bounce_limit(mq->queue, limit);
 225                 blk_queue_max_sectors(mq->queue, host->max_req_size / 512);
 226                 blk_queue_max_phys_segments(mq->queue, host->max_phys_segs);
 227                 blk_queue_max_hw_segments(mq->queue, host->max_hw_segs);
 228                 blk_queue_max_segment_size(mq->queue, host->max_seg_size);
 229
 230                 mq->sg = kmalloc(sizeof(struct scatterlist) *
 231                         host->max_phys_segs, GFP_KERNEL);
 232                 if (!mq->sg) {
 233                         ret = -ENOMEM;
 234                         goto cleanup_queue;
 235                 }
 236         }
 237
 238         init_MUTEX(&mq->thread_sem);
 239
 240         mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd");
 241         if (IS_ERR(mq->thread)) {
 242                 ret = PTR_ERR(mq->thread);
 243                 goto free_bounce_sg;
 244         }
 245
 246         return 0;
 247  free_bounce_sg:
 248         if (mq->bounce_sg)
 249                 kfree(mq->bounce_sg);
 250         mq->bounce_sg = NULL;
 251  cleanup_queue:
 252         if (mq->sg)
 253                 kfree(mq->sg);
 254         mq->sg = NULL;
 255         if (mq->bounce_buf)
 256                 kfree(mq->bounce_buf);
 257         mq->bounce_buf = NULL;
 258         blk_cleanup_queue(mq->queue);
 259         return ret;
 260 }
 261
 262 void mmc_cleanup_queue(struct mmc_queue *mq)
 263 {
 264         struct request_queue *q = mq->queue;
 265         unsigned long flags;
 266
 267         /* Mark that we should start throwing out stragglers */
 268         spin_lock_irqsave(q->queue_lock, flags);
 269         q->queuedata = NULL;
 270         spin_unlock_irqrestore(q->queue_lock, flags);
 271
 272         /* Make sure the queue isn't suspended, as that will deadlock */
 273         mmc_queue_resume(mq);
 274
 275         /* Then terminate our worker thread */
 276         kthread_stop(mq->thread);
 277
 278         if (mq->bounce_sg)
 279                 kfree(mq->bounce_sg);
 280         mq->bounce_sg = NULL;
 281
 282         kfree(mq->sg);
 283         mq->sg = NULL;
 284
 285         if (mq->bounce_buf)
 286                 kfree(mq->bounce_buf);
 287         mq->bounce_buf = NULL;
 288
 289         blk_cleanup_queue(mq->queue);
 290
 291         mq->card = NULL;
 292 }
 293 EXPORT_SYMBOL(mmc_cleanup_queue);
 294
 295 /**
 296  * mmc_queue_suspend - suspend a MMC request queue
 297  * @mq: MMC queue to suspend
 298  *
 299  * Stop the block request queue, and wait for our thread to
 300  * complete any outstanding requests.  This ensures that we
 301  * won't suspend while a request is being processed.
 302  */
 303 void mmc_queue_suspend(struct mmc_queue *mq)
 304 {
 305         struct request_queue *q = mq->queue;
 306         unsigned long flags;
 307
 308         if (!(mq->flags & MMC_QUEUE_SUSPENDED)) {
 309                 mq->flags |= MMC_QUEUE_SUSPENDED;
 310
 311                 spin_lock_irqsave(q->queue_lock, flags);
 312                 blk_stop_queue(q);
 313                 spin_unlock_irqrestore(q->queue_lock, flags);
 314
 315                 down(&mq->thread_sem);
 316         }
 317 }
 318
 319 /**
 320  * mmc_queue_resume - resume a previously suspended MMC request queue
 321  * @mq: MMC queue to resume
 322  */
 323 void mmc_queue_resume(struct mmc_queue *mq)
 324 {
 325         struct request_queue *q = mq->queue;
 326         unsigned long flags;
 327
 328         if (mq->flags & MMC_QUEUE_SUSPENDED) {
 329                 mq->flags &= ~MMC_QUEUE_SUSPENDED;
 330
 331                 up(&mq->thread_sem);
 332
 333                 spin_lock_irqsave(q->queue_lock, flags);
 334                 blk_start_queue(q);
 335                 spin_unlock_irqrestore(q->queue_lock, flags);
 336         }
 337 }
 338
 339 static void copy_sg(struct scatterlist *dst, unsigned int dst_len,
 340         struct scatterlist *src, unsigned int src_len)
 341 {
 342         unsigned int chunk;
 343         char *dst_buf, *src_buf;
 344         unsigned int dst_size, src_size;
 345
 346         dst_buf = NULL;
 347         src_buf = NULL;
 348         dst_size = 0;
 349         src_size = 0;
 350
 351         while (src_len) {
 352                 BUG_ON(dst_len == 0);
 353
 354                 if (dst_size == 0) {
 355                         dst_buf = page_address(dst->page) + dst->offset;
 356                         dst_size = dst->length;
 357                 }
 358
 359                 if (src_size == 0) {
 360                         src_buf = page_address(src->page) + src->offset;
 361                         src_size = src->length;
 362                 }
 363
 364                 chunk = min(dst_size, src_size);
 365
 366                 memcpy(dst_buf, src_buf, chunk);
 367
 368                 dst_buf += chunk;
 369                 src_buf += chunk;
 370                 dst_size -= chunk;
 371                 src_size -= chunk;
 372
 373                 if (dst_size == 0) {
 374                         dst++;
 375                         dst_len--;
 376                 }
 377
 378                 if (src_size == 0) {
 379                         src++;
 380                         src_len--;
 381                 }
 382         }
 383 }
 384
 385 unsigned int mmc_queue_map_sg(struct mmc_queue *mq)
 386 {
 387         unsigned int sg_len;
 388
 389         if (!mq->bounce_buf)
 390                 return blk_rq_map_sg(mq->queue, mq->req, mq->sg);
 391
 392         BUG_ON(!mq->bounce_sg);
 393
 394         sg_len = blk_rq_map_sg(mq->queue, mq->req, mq->bounce_sg);
 395
 396         mq->bounce_sg_len = sg_len;
 397
 398         /*
 399          * Shortcut in the event we only get a single entry.
 400          */
 401         if (sg_len == 1) {
 402                 memcpy(mq->sg, mq->bounce_sg, sizeof(struct scatterlist));
 403                 return 1;
 404         }
 405
 406         mq->sg[0].page = virt_to_page(mq->bounce_buf);
 407         mq->sg[0].offset = offset_in_page(mq->bounce_buf);
 408         mq->sg[0].length = 0;
 409
 410         while (sg_len) {
 411                 mq->sg[0].length += mq->bounce_sg[sg_len - 1].length;
 412                 sg_len--;
 413         }
 414
 415         return 1;
 416 }
 417
 418 void mmc_queue_bounce_pre(struct mmc_queue *mq)
 419 {
 420         if (!mq->bounce_buf)
 421                 return;
 422
 423         if (mq->bounce_sg_len == 1)
 424                 return;
 425         if (rq_data_dir(mq->req) != WRITE)
 426                 return;
 427
 428         copy_sg(mq->sg, 1, mq->bounce_sg, mq->bounce_sg_len);
 429 }
 430
 431 void mmc_queue_bounce_post(struct mmc_queue *mq)
 432 {
 433         if (!mq->bounce_buf)
 434                 return;
 435
 436         if (mq->bounce_sg_len == 1)
 437                 return;
 438         if (rq_data_dir(mq->req) != READ)
 439                 return;
 440
 441         copy_sg(mq->bounce_sg, mq->bounce_sg_len, mq->sg, 1);
 442 }
 443