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1 /*
2 * Filename: dev.c
3 *
4 *
5 * Authors: Joshua Morris <josh.h.morris@us.ibm.com>
6 *	Philip Kelleher <pjk1939@linux.vnet.ibm.com>
7 *
8 * (C) Copyright 2013 IBM Corporation
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software Foundation,
22 * Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
23 */
24 
25 #include <linux/kernel.h>
26 #include <linux/interrupt.h>
27 #include <linux/module.h>
28 #include <linux/pci.h>
29 #include <linux/slab.h>
30 
31 #include <linux/hdreg.h>
32 #include <linux/genhd.h>
33 #include <linux/blkdev.h>
34 #include <linux/bio.h>
35 
36 #include <linux/fs.h>
37 
38 #include "rsxx_priv.h"
39 
40 static unsigned int blkdev_minors = 64;
41 module_param(blkdev_minors, uint, 0444);
42 MODULE_PARM_DESC(blkdev_minors, "Number of minors(partitions)");
43 
44 /*
45  * For now I'm making this tweakable in case any applications hit this limit.
46  * If you see a "bio too big" error in the log you will need to raise this
47  * value.
48  */
49 static unsigned int blkdev_max_hw_sectors = 1024;
50 module_param(blkdev_max_hw_sectors, uint, 0444);
51 MODULE_PARM_DESC(blkdev_max_hw_sectors, "Max hw sectors for a single BIO");
52 
53 static unsigned int enable_blkdev = 1;
54 module_param(enable_blkdev , uint, 0444);
55 MODULE_PARM_DESC(enable_blkdev, "Enable block device interfaces");
56 
57 
58 struct rsxx_bio_meta {
59 	struct bio	*bio;
60 	atomic_t	pending_dmas;
61 	atomic_t	error;
62 	unsigned long	start_time;
63 };
64 
65 static struct kmem_cache *bio_meta_pool;
66 
67 /*----------------- Block Device Operations -----------------*/
rsxx_blkdev_ioctl(struct block_device * bdev,fmode_t mode,unsigned int cmd,unsigned long arg)68 static int rsxx_blkdev_ioctl(struct block_device *bdev,
69 				 fmode_t mode,
70 				 unsigned int cmd,
71 				 unsigned long arg)
72 {
73 	struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
74 
75 	switch (cmd) {
76 	case RSXX_GETREG:
77 		return rsxx_reg_access(card, (void __user *)arg, 1);
78 	case RSXX_SETREG:
79 		return rsxx_reg_access(card, (void __user *)arg, 0);
80 	}
81 
82 	return -ENOTTY;
83 }
84 
rsxx_getgeo(struct block_device * bdev,struct hd_geometry * geo)85 static int rsxx_getgeo(struct block_device *bdev, struct hd_geometry *geo)
86 {
87 	struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
88 	u64 blocks = card->size8 >> 9;
89 
90 	/*
91 	 * get geometry: Fake it. I haven't found any drivers that set
92 	 * geo->start, so we won't either.
93 	 */
94 	if (card->size8) {
95 		geo->heads = 64;
96 		geo->sectors = 16;
97 		do_div(blocks, (geo->heads * geo->sectors));
98 		geo->cylinders = blocks;
99 	} else {
100 		geo->heads = 0;
101 		geo->sectors = 0;
102 		geo->cylinders = 0;
103 	}
104 	return 0;
105 }
106 
107 static const struct block_device_operations rsxx_fops = {
108 	.owner		= THIS_MODULE,
109 	.getgeo		= rsxx_getgeo,
110 	.ioctl		= rsxx_blkdev_ioctl,
111 };
112 
disk_stats_start(struct rsxx_cardinfo * card,struct bio * bio)113 static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio)
114 {
115 	struct hd_struct *part0 = &card->gendisk->part0;
116 	int rw = bio_data_dir(bio);
117 	int cpu;
118 
119 	cpu = part_stat_lock();
120 
121 	part_round_stats(cpu, part0);
122 	part_inc_in_flight(part0, rw);
123 
124 	part_stat_unlock();
125 }
126 
disk_stats_complete(struct rsxx_cardinfo * card,struct bio * bio,unsigned long start_time)127 static void disk_stats_complete(struct rsxx_cardinfo *card,
128 				struct bio *bio,
129 				unsigned long start_time)
130 {
131 	struct hd_struct *part0 = &card->gendisk->part0;
132 	unsigned long duration = jiffies - start_time;
133 	int rw = bio_data_dir(bio);
134 	int cpu;
135 
136 	cpu = part_stat_lock();
137 
138 	part_stat_add(cpu, part0, sectors[rw], bio_sectors(bio));
139 	part_stat_inc(cpu, part0, ios[rw]);
140 	part_stat_add(cpu, part0, ticks[rw], duration);
141 
142 	part_round_stats(cpu, part0);
143 	part_dec_in_flight(part0, rw);
144 
145 	part_stat_unlock();
146 }
147 
bio_dma_done_cb(struct rsxx_cardinfo * card,void * cb_data,unsigned int error)148 static void bio_dma_done_cb(struct rsxx_cardinfo *card,
149 			    void *cb_data,
150 			    unsigned int error)
151 {
152 	struct rsxx_bio_meta *meta = cb_data;
153 
154 	if (error)
155 		atomic_set(&meta->error, 1);
156 
157 	if (atomic_dec_and_test(&meta->pending_dmas)) {
158 		if (!card->eeh_state && card->gendisk)
159 			disk_stats_complete(card, meta->bio, meta->start_time);
160 
161 		bio_endio(meta->bio, atomic_read(&meta->error) ? -EIO : 0);
162 		kmem_cache_free(bio_meta_pool, meta);
163 	}
164 }
165 
rsxx_make_request(struct request_queue * q,struct bio * bio)166 static void rsxx_make_request(struct request_queue *q, struct bio *bio)
167 {
168 	struct rsxx_cardinfo *card = q->queuedata;
169 	struct rsxx_bio_meta *bio_meta;
170 	int st = -EINVAL;
171 
172 	might_sleep();
173 
174 	if (!card)
175 		goto req_err;
176 
177 	if (bio_end_sector(bio) > get_capacity(card->gendisk))
178 		goto req_err;
179 
180 	if (unlikely(card->halt)) {
181 		st = -EFAULT;
182 		goto req_err;
183 	}
184 
185 	if (unlikely(card->dma_fault)) {
186 		st = (-EFAULT);
187 		goto req_err;
188 	}
189 
190 	if (bio->bi_iter.bi_size == 0) {
191 		dev_err(CARD_TO_DEV(card), "size zero BIO!\n");
192 		goto req_err;
193 	}
194 
195 	bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL);
196 	if (!bio_meta) {
197 		st = -ENOMEM;
198 		goto req_err;
199 	}
200 
201 	bio_meta->bio = bio;
202 	atomic_set(&bio_meta->error, 0);
203 	atomic_set(&bio_meta->pending_dmas, 0);
204 	bio_meta->start_time = jiffies;
205 
206 	if (!unlikely(card->halt))
207 		disk_stats_start(card, bio);
208 
209 	dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
210 		 bio_data_dir(bio) ? 'W' : 'R', bio_meta,
211 		 (u64)bio->bi_iter.bi_sector << 9, bio->bi_iter.bi_size);
212 
213 	st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas,
214 				    bio_dma_done_cb, bio_meta);
215 	if (st)
216 		goto queue_err;
217 
218 	return;
219 
220 queue_err:
221 	kmem_cache_free(bio_meta_pool, bio_meta);
222 req_err:
223 	bio_endio(bio, st);
224 }
225 
226 /*----------------- Device Setup -------------------*/
rsxx_discard_supported(struct rsxx_cardinfo * card)227 static bool rsxx_discard_supported(struct rsxx_cardinfo *card)
228 {
229 	unsigned char pci_rev;
230 
231 	pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev);
232 
233 	return (pci_rev >= RSXX_DISCARD_SUPPORT);
234 }
235 
rsxx_attach_dev(struct rsxx_cardinfo * card)236 int rsxx_attach_dev(struct rsxx_cardinfo *card)
237 {
238 	mutex_lock(&card->dev_lock);
239 
240 	/* The block device requires the stripe size from the config. */
241 	if (enable_blkdev) {
242 		if (card->config_valid)
243 			set_capacity(card->gendisk, card->size8 >> 9);
244 		else
245 			set_capacity(card->gendisk, 0);
246 		add_disk(card->gendisk);
247 
248 		card->bdev_attached = 1;
249 	}
250 
251 	mutex_unlock(&card->dev_lock);
252 
253 	return 0;
254 }
255 
rsxx_detach_dev(struct rsxx_cardinfo * card)256 void rsxx_detach_dev(struct rsxx_cardinfo *card)
257 {
258 	mutex_lock(&card->dev_lock);
259 
260 	if (card->bdev_attached) {
261 		del_gendisk(card->gendisk);
262 		card->bdev_attached = 0;
263 	}
264 
265 	mutex_unlock(&card->dev_lock);
266 }
267 
rsxx_setup_dev(struct rsxx_cardinfo * card)268 int rsxx_setup_dev(struct rsxx_cardinfo *card)
269 {
270 	unsigned short blk_size;
271 
272 	mutex_init(&card->dev_lock);
273 
274 	if (!enable_blkdev)
275 		return 0;
276 
277 	card->major = register_blkdev(0, DRIVER_NAME);
278 	if (card->major < 0) {
279 		dev_err(CARD_TO_DEV(card), "Failed to get major number\n");
280 		return -ENOMEM;
281 	}
282 
283 	card->queue = blk_alloc_queue(GFP_KERNEL);
284 	if (!card->queue) {
285 		dev_err(CARD_TO_DEV(card), "Failed queue alloc\n");
286 		unregister_blkdev(card->major, DRIVER_NAME);
287 		return -ENOMEM;
288 	}
289 
290 	card->gendisk = alloc_disk(blkdev_minors);
291 	if (!card->gendisk) {
292 		dev_err(CARD_TO_DEV(card), "Failed disk alloc\n");
293 		blk_cleanup_queue(card->queue);
294 		unregister_blkdev(card->major, DRIVER_NAME);
295 		return -ENOMEM;
296 	}
297 
298 	if (card->config_valid) {
299 		blk_size = card->config.data.block_size;
300 		blk_queue_dma_alignment(card->queue, blk_size - 1);
301 		blk_queue_logical_block_size(card->queue, blk_size);
302 	}
303 
304 	blk_queue_make_request(card->queue, rsxx_make_request);
305 	blk_queue_bounce_limit(card->queue, BLK_BOUNCE_ANY);
306 	blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors);
307 	blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE);
308 
309 	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, card->queue);
310 	queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, card->queue);
311 	if (rsxx_discard_supported(card)) {
312 		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, card->queue);
313 		blk_queue_max_discard_sectors(card->queue,
314 						RSXX_HW_BLK_SIZE >> 9);
315 		card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE;
316 		card->queue->limits.discard_alignment   = RSXX_HW_BLK_SIZE;
317 		card->queue->limits.discard_zeroes_data = 1;
318 	}
319 
320 	card->queue->queuedata = card;
321 
322 	snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name),
323 		 "rsxx%d", card->disk_id);
324 	card->gendisk->driverfs_dev = &card->dev->dev;
325 	card->gendisk->major = card->major;
326 	card->gendisk->first_minor = 0;
327 	card->gendisk->fops = &rsxx_fops;
328 	card->gendisk->private_data = card;
329 	card->gendisk->queue = card->queue;
330 
331 	return 0;
332 }
333 
rsxx_destroy_dev(struct rsxx_cardinfo * card)334 void rsxx_destroy_dev(struct rsxx_cardinfo *card)
335 {
336 	if (!enable_blkdev)
337 		return;
338 
339 	put_disk(card->gendisk);
340 	card->gendisk = NULL;
341 
342 	blk_cleanup_queue(card->queue);
343 	card->queue->queuedata = NULL;
344 	unregister_blkdev(card->major, DRIVER_NAME);
345 }
346 
rsxx_dev_init(void)347 int rsxx_dev_init(void)
348 {
349 	bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN);
350 	if (!bio_meta_pool)
351 		return -ENOMEM;
352 
353 	return 0;
354 }
355 
rsxx_dev_cleanup(void)356 void rsxx_dev_cleanup(void)
357 {
358 	kmem_cache_destroy(bio_meta_pool);
359 }
360 
361 
362