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