1 /* 2 * Copyright (C) 2003 Russell King, All Rights Reserved. 3 * Copyright 2006-2007 Pierre Ossman 4 * 5 * This program is free software; you can redistribute it and/or modify 6 * it under the terms of the GNU General Public License version 2 as 7 * published by the Free Software Foundation. 8 * 9 */ 10 #include <linux/slab.h> 11 #include <linux/module.h> 12 #include <linux/blkdev.h> 13 #include <linux/freezer.h> 14 #include <linux/kthread.h> 15 #include <linux/scatterlist.h> 16 #include <linux/dma-mapping.h> 17 18 #include <linux/mmc/card.h> 19 #include <linux/mmc/host.h> 20 21 #include "queue.h" 22 #include "block.h" 23 #include "core.h" 24 #include "card.h" 25 26 /* 27 * Prepare a MMC request. This just filters out odd stuff. 28 */ 29 static int mmc_prep_request(struct request_queue *q, struct request *req) 30 { 31 struct mmc_queue *mq = q->queuedata; 32 33 if (mq && mmc_card_removed(mq->card)) 34 return BLKPREP_KILL; 35 36 req->rq_flags |= RQF_DONTPREP; 37 38 return BLKPREP_OK; 39 } 40 41 static int mmc_queue_thread(void *d) 42 { 43 struct mmc_queue *mq = d; 44 struct request_queue *q = mq->queue; 45 struct mmc_context_info *cntx = &mq->card->host->context_info; 46 47 current->flags |= PF_MEMALLOC; 48 49 down(&mq->thread_sem); 50 do { 51 struct request *req; 52 53 spin_lock_irq(q->queue_lock); 54 set_current_state(TASK_INTERRUPTIBLE); 55 req = blk_fetch_request(q); 56 mq->asleep = false; 57 cntx->is_waiting_last_req = false; 58 cntx->is_new_req = false; 59 if (!req) { 60 /* 61 * Dispatch queue is empty so set flags for 62 * mmc_request_fn() to wake us up. 63 */ 64 if (mq->qcnt) 65 cntx->is_waiting_last_req = true; 66 else 67 mq->asleep = true; 68 } 69 spin_unlock_irq(q->queue_lock); 70 71 if (req || mq->qcnt) { 72 set_current_state(TASK_RUNNING); 73 mmc_blk_issue_rq(mq, req); 74 cond_resched(); 75 } else { 76 if (kthread_should_stop()) { 77 set_current_state(TASK_RUNNING); 78 break; 79 } 80 up(&mq->thread_sem); 81 schedule(); 82 down(&mq->thread_sem); 83 } 84 } while (1); 85 up(&mq->thread_sem); 86 87 return 0; 88 } 89 90 /* 91 * Generic MMC request handler. This is called for any queue on a 92 * particular host. When the host is not busy, we look for a request 93 * on any queue on this host, and attempt to issue it. This may 94 * not be the queue we were asked to process. 95 */ 96 static void mmc_request_fn(struct request_queue *q) 97 { 98 struct mmc_queue *mq = q->queuedata; 99 struct request *req; 100 struct mmc_context_info *cntx; 101 102 if (!mq) { 103 while ((req = blk_fetch_request(q)) != NULL) { 104 req->rq_flags |= RQF_QUIET; 105 __blk_end_request_all(req, BLK_STS_IOERR); 106 } 107 return; 108 } 109 110 cntx = &mq->card->host->context_info; 111 112 if (cntx->is_waiting_last_req) { 113 cntx->is_new_req = true; 114 wake_up_interruptible(&cntx->wait); 115 } 116 117 if (mq->asleep) 118 wake_up_process(mq->thread); 119 } 120 121 static struct scatterlist *mmc_alloc_sg(int sg_len, gfp_t gfp) 122 { 123 struct scatterlist *sg; 124 125 sg = kmalloc_array(sg_len, sizeof(*sg), gfp); 126 if (sg) 127 sg_init_table(sg, sg_len); 128 129 return sg; 130 } 131 132 static void mmc_queue_setup_discard(struct request_queue *q, 133 struct mmc_card *card) 134 { 135 unsigned max_discard; 136 137 max_discard = mmc_calc_max_discard(card); 138 if (!max_discard) 139 return; 140 141 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q); 142 blk_queue_max_discard_sectors(q, max_discard); 143 q->limits.discard_granularity = card->pref_erase << 9; 144 /* granularity must not be greater than max. discard */ 145 if (card->pref_erase > max_discard) 146 q->limits.discard_granularity = 0; 147 if (mmc_can_secure_erase_trim(card)) 148 queue_flag_set_unlocked(QUEUE_FLAG_SECERASE, q); 149 } 150 151 /** 152 * mmc_init_request() - initialize the MMC-specific per-request data 153 * @q: the request queue 154 * @req: the request 155 * @gfp: memory allocation policy 156 */ 157 static int mmc_init_request(struct request_queue *q, struct request *req, 158 gfp_t gfp) 159 { 160 struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req); 161 struct mmc_queue *mq = q->queuedata; 162 struct mmc_card *card = mq->card; 163 struct mmc_host *host = card->host; 164 165 mq_rq->sg = mmc_alloc_sg(host->max_segs, gfp); 166 if (!mq_rq->sg) 167 return -ENOMEM; 168 169 return 0; 170 } 171 172 static void mmc_exit_request(struct request_queue *q, struct request *req) 173 { 174 struct mmc_queue_req *mq_rq = req_to_mmc_queue_req(req); 175 176 kfree(mq_rq->sg); 177 mq_rq->sg = NULL; 178 } 179 180 static void mmc_setup_queue(struct mmc_queue *mq, struct mmc_card *card) 181 { 182 struct mmc_host *host = card->host; 183 u64 limit = BLK_BOUNCE_HIGH; 184 185 if (mmc_dev(host)->dma_mask && *mmc_dev(host)->dma_mask) 186 limit = (u64)dma_max_pfn(mmc_dev(host)) << PAGE_SHIFT; 187 188 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, mq->queue); 189 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, mq->queue); 190 if (mmc_can_erase(card)) 191 mmc_queue_setup_discard(mq->queue, card); 192 193 blk_queue_bounce_limit(mq->queue, limit); 194 blk_queue_max_hw_sectors(mq->queue, 195 min(host->max_blk_count, host->max_req_size / 512)); 196 blk_queue_max_segments(mq->queue, host->max_segs); 197 blk_queue_max_segment_size(mq->queue, host->max_seg_size); 198 199 /* Initialize thread_sem even if it is not used */ 200 sema_init(&mq->thread_sem, 1); 201 } 202 203 /** 204 * mmc_init_queue - initialise a queue structure. 205 * @mq: mmc queue 206 * @card: mmc card to attach this queue 207 * @lock: queue lock 208 * @subname: partition subname 209 * 210 * Initialise a MMC card request queue. 211 */ 212 int mmc_init_queue(struct mmc_queue *mq, struct mmc_card *card, 213 spinlock_t *lock, const char *subname) 214 { 215 struct mmc_host *host = card->host; 216 int ret = -ENOMEM; 217 218 mq->card = card; 219 mq->queue = blk_alloc_queue(GFP_KERNEL); 220 if (!mq->queue) 221 return -ENOMEM; 222 mq->queue->queue_lock = lock; 223 mq->queue->request_fn = mmc_request_fn; 224 mq->queue->init_rq_fn = mmc_init_request; 225 mq->queue->exit_rq_fn = mmc_exit_request; 226 mq->queue->cmd_size = sizeof(struct mmc_queue_req); 227 mq->queue->queuedata = mq; 228 mq->qcnt = 0; 229 ret = blk_init_allocated_queue(mq->queue); 230 if (ret) { 231 blk_cleanup_queue(mq->queue); 232 return ret; 233 } 234 235 blk_queue_prep_rq(mq->queue, mmc_prep_request); 236 237 mmc_setup_queue(mq, card); 238 239 mq->thread = kthread_run(mmc_queue_thread, mq, "mmcqd/%d%s", 240 host->index, subname ? subname : ""); 241 242 if (IS_ERR(mq->thread)) { 243 ret = PTR_ERR(mq->thread); 244 goto cleanup_queue; 245 } 246 247 return 0; 248 249 cleanup_queue: 250 blk_cleanup_queue(mq->queue); 251 return ret; 252 } 253 254 void mmc_cleanup_queue(struct mmc_queue *mq) 255 { 256 struct request_queue *q = mq->queue; 257 unsigned long flags; 258 259 /* Make sure the queue isn't suspended, as that will deadlock */ 260 mmc_queue_resume(mq); 261 262 /* Then terminate our worker thread */ 263 kthread_stop(mq->thread); 264 265 /* Empty the queue */ 266 spin_lock_irqsave(q->queue_lock, flags); 267 q->queuedata = NULL; 268 blk_start_queue(q); 269 spin_unlock_irqrestore(q->queue_lock, flags); 270 271 mq->card = NULL; 272 } 273 EXPORT_SYMBOL(mmc_cleanup_queue); 274 275 /** 276 * mmc_queue_suspend - suspend a MMC request queue 277 * @mq: MMC queue to suspend 278 * 279 * Stop the block request queue, and wait for our thread to 280 * complete any outstanding requests. This ensures that we 281 * won't suspend while a request is being processed. 282 */ 283 void mmc_queue_suspend(struct mmc_queue *mq) 284 { 285 struct request_queue *q = mq->queue; 286 unsigned long flags; 287 288 if (!mq->suspended) { 289 mq->suspended |= true; 290 291 spin_lock_irqsave(q->queue_lock, flags); 292 blk_stop_queue(q); 293 spin_unlock_irqrestore(q->queue_lock, flags); 294 295 down(&mq->thread_sem); 296 } 297 } 298 299 /** 300 * mmc_queue_resume - resume a previously suspended MMC request queue 301 * @mq: MMC queue to resume 302 */ 303 void mmc_queue_resume(struct mmc_queue *mq) 304 { 305 struct request_queue *q = mq->queue; 306 unsigned long flags; 307 308 if (mq->suspended) { 309 mq->suspended = false; 310 311 up(&mq->thread_sem); 312 313 spin_lock_irqsave(q->queue_lock, flags); 314 blk_start_queue(q); 315 spin_unlock_irqrestore(q->queue_lock, flags); 316 } 317 } 318 319 /* 320 * Prepare the sg list(s) to be handed of to the host driver 321 */ 322 unsigned int mmc_queue_map_sg(struct mmc_queue *mq, struct mmc_queue_req *mqrq) 323 { 324 struct request *req = mmc_queue_req_to_req(mqrq); 325 326 return blk_rq_map_sg(mq->queue, req, mqrq->sg); 327 } 328