Home Home > GIT Browse > stable-xen
summaryrefslogtreecommitdiff
blob: 7f4acebf46571d5cb5d8cbb2ce281ab5dbe14e30 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
/*
* Filename: dev.c
*
*
* Authors: Joshua Morris <josh.h.morris@us.ibm.com>
*	Philip Kelleher <pjk1939@linux.vnet.ibm.com>
*
* (C) Copyright 2013 IBM Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/

#include <linux/kernel.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/slab.h>

#include <linux/hdreg.h>
#include <linux/genhd.h>
#include <linux/blkdev.h>
#include <linux/bio.h>

#include <linux/fs.h>

#include "rsxx_priv.h"

static unsigned int blkdev_minors = 64;
module_param(blkdev_minors, uint, 0444);
MODULE_PARM_DESC(blkdev_minors, "Number of minors(partitions)");

/*
 * For now I'm making this tweakable in case any applications hit this limit.
 * If you see a "bio too big" error in the log you will need to raise this
 * value.
 */
static unsigned int blkdev_max_hw_sectors = 1024;
module_param(blkdev_max_hw_sectors, uint, 0444);
MODULE_PARM_DESC(blkdev_max_hw_sectors, "Max hw sectors for a single BIO");

static unsigned int enable_blkdev = 1;
module_param(enable_blkdev , uint, 0444);
MODULE_PARM_DESC(enable_blkdev, "Enable block device interfaces");


struct rsxx_bio_meta {
	struct bio	*bio;
	atomic_t	pending_dmas;
	atomic_t	error;
	unsigned long	start_time;
};

static struct kmem_cache *bio_meta_pool;

/*----------------- Block Device Operations -----------------*/
static int rsxx_blkdev_ioctl(struct block_device *bdev,
				 fmode_t mode,
				 unsigned int cmd,
				 unsigned long arg)
{
	struct rsxx_cardinfo *card = bdev->bd_disk->private_data;

	switch (cmd) {
	case RSXX_GETREG:
		return rsxx_reg_access(card, (void __user *)arg, 1);
	case RSXX_SETREG:
		return rsxx_reg_access(card, (void __user *)arg, 0);
	}

	return -ENOTTY;
}

static int rsxx_getgeo(struct block_device *bdev, struct hd_geometry *geo)
{
	struct rsxx_cardinfo *card = bdev->bd_disk->private_data;
	u64 blocks = card->size8 >> 9;

	/*
	 * get geometry: Fake it. I haven't found any drivers that set
	 * geo->start, so we won't either.
	 */
	if (card->size8) {
		geo->heads = 64;
		geo->sectors = 16;
		do_div(blocks, (geo->heads * geo->sectors));
		geo->cylinders = blocks;
	} else {
		geo->heads = 0;
		geo->sectors = 0;
		geo->cylinders = 0;
	}
	return 0;
}

static const struct block_device_operations rsxx_fops = {
	.owner		= THIS_MODULE,
	.getgeo		= rsxx_getgeo,
	.ioctl		= rsxx_blkdev_ioctl,
};

static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio)
{
	generic_start_io_acct(bio_data_dir(bio), bio_sectors(bio),
			     &card->gendisk->part0);
}

static void disk_stats_complete(struct rsxx_cardinfo *card,
				struct bio *bio,
				unsigned long start_time)
{
	generic_end_io_acct(bio_data_dir(bio), &card->gendisk->part0,
			   start_time);
}

static void bio_dma_done_cb(struct rsxx_cardinfo *card,
			    void *cb_data,
			    unsigned int error)
{
	struct rsxx_bio_meta *meta = cb_data;

	if (error)
		atomic_set(&meta->error, 1);

	if (atomic_dec_and_test(&meta->pending_dmas)) {
		if (!card->eeh_state && card->gendisk)
			disk_stats_complete(card, meta->bio, meta->start_time);

		if (atomic_read(&meta->error))
			bio_io_error(meta->bio);
		else
			bio_endio(meta->bio);
		kmem_cache_free(bio_meta_pool, meta);
	}
}

static blk_qc_t rsxx_make_request(struct request_queue *q, struct bio *bio)
{
	struct rsxx_cardinfo *card = q->queuedata;
	struct rsxx_bio_meta *bio_meta;
	blk_status_t st = BLK_STS_IOERR;

	blk_queue_split(q, &bio);

	might_sleep();

	if (!card)
		goto req_err;

	if (bio_end_sector(bio) > get_capacity(card->gendisk))
		goto req_err;

	if (unlikely(card->halt))
		goto req_err;

	if (unlikely(card->dma_fault))
		goto req_err;

	if (bio->bi_iter.bi_size == 0) {
		dev_err(CARD_TO_DEV(card), "size zero BIO!\n");
		goto req_err;
	}

	bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL);
	if (!bio_meta) {
		st = BLK_STS_RESOURCE;
		goto req_err;
	}

	bio_meta->bio = bio;
	atomic_set(&bio_meta->error, 0);
	atomic_set(&bio_meta->pending_dmas, 0);
	bio_meta->start_time = jiffies;

	if (!unlikely(card->halt))
		disk_stats_start(card, bio);

	dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n",
		 bio_data_dir(bio) ? 'W' : 'R', bio_meta,
		 (u64)bio->bi_iter.bi_sector << 9, bio->bi_iter.bi_size);

	st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas,
				    bio_dma_done_cb, bio_meta);
	if (st)
		goto queue_err;

	return BLK_QC_T_NONE;

queue_err:
	kmem_cache_free(bio_meta_pool, bio_meta);
req_err:
	if (st)
		bio->bi_status = st;
	bio_endio(bio);
	return BLK_QC_T_NONE;
}

/*----------------- Device Setup -------------------*/
static bool rsxx_discard_supported(struct rsxx_cardinfo *card)
{
	unsigned char pci_rev;

	pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev);

	return (pci_rev >= RSXX_DISCARD_SUPPORT);
}

int rsxx_attach_dev(struct rsxx_cardinfo *card)
{
	mutex_lock(&card->dev_lock);

	/* The block device requires the stripe size from the config. */
	if (enable_blkdev) {
		if (card->config_valid)
			set_capacity(card->gendisk, card->size8 >> 9);
		else
			set_capacity(card->gendisk, 0);
		device_add_disk(CARD_TO_DEV(card), card->gendisk);
		card->bdev_attached = 1;
	}

	mutex_unlock(&card->dev_lock);

	return 0;
}

void rsxx_detach_dev(struct rsxx_cardinfo *card)
{
	mutex_lock(&card->dev_lock);

	if (card->bdev_attached) {
		del_gendisk(card->gendisk);
		card->bdev_attached = 0;
	}

	mutex_unlock(&card->dev_lock);
}

int rsxx_setup_dev(struct rsxx_cardinfo *card)
{
	unsigned short blk_size;

	mutex_init(&card->dev_lock);

	if (!enable_blkdev)
		return 0;

	card->major = register_blkdev(0, DRIVER_NAME);
	if (card->major < 0) {
		dev_err(CARD_TO_DEV(card), "Failed to get major number\n");
		return -ENOMEM;
	}

	card->queue = blk_alloc_queue(GFP_KERNEL);
	if (!card->queue) {
		dev_err(CARD_TO_DEV(card), "Failed queue alloc\n");
		unregister_blkdev(card->major, DRIVER_NAME);
		return -ENOMEM;
	}

	card->gendisk = alloc_disk(blkdev_minors);
	if (!card->gendisk) {
		dev_err(CARD_TO_DEV(card), "Failed disk alloc\n");
		blk_cleanup_queue(card->queue);
		unregister_blkdev(card->major, DRIVER_NAME);
		return -ENOMEM;
	}

	if (card->config_valid) {
		blk_size = card->config.data.block_size;
		blk_queue_dma_alignment(card->queue, blk_size - 1);
		blk_queue_logical_block_size(card->queue, blk_size);
	}

	blk_queue_make_request(card->queue, rsxx_make_request);
	blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors);
	blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE);

	queue_flag_set_unlocked(QUEUE_FLAG_NONROT, card->queue);
	queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, card->queue);
	if (rsxx_discard_supported(card)) {
		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, card->queue);
		blk_queue_max_discard_sectors(card->queue,
						RSXX_HW_BLK_SIZE >> 9);
		card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE;
		card->queue->limits.discard_alignment   = RSXX_HW_BLK_SIZE;
	}

	card->queue->queuedata = card;

	snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name),
		 "rsxx%d", card->disk_id);
	card->gendisk->major = card->major;
	card->gendisk->first_minor = 0;
	card->gendisk->fops = &rsxx_fops;
	card->gendisk->private_data = card;
	card->gendisk->queue = card->queue;

	return 0;
}

void rsxx_destroy_dev(struct rsxx_cardinfo *card)
{
	if (!enable_blkdev)
		return;

	put_disk(card->gendisk);
	card->gendisk = NULL;

	blk_cleanup_queue(card->queue);
	card->queue->queuedata = NULL;
	unregister_blkdev(card->major, DRIVER_NAME);
}

int rsxx_dev_init(void)
{
	bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN);
	if (!bio_meta_pool)
		return -ENOMEM;

	return 0;
}

void rsxx_dev_cleanup(void)
{
	kmem_cache_destroy(bio_meta_pool);
}