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 40static unsigned int blkdev_minors = 64; 41module_param(blkdev_minors, uint, 0444); 42MODULE_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 */ 49static unsigned int blkdev_max_hw_sectors = 1024; 50module_param(blkdev_max_hw_sectors, uint, 0444); 51MODULE_PARM_DESC(blkdev_max_hw_sectors, "Max hw sectors for a single BIO"); 52 53static unsigned int enable_blkdev = 1; 54module_param(enable_blkdev , uint, 0444); 55MODULE_PARM_DESC(enable_blkdev, "Enable block device interfaces"); 56 57 58struct rsxx_bio_meta { 59 struct bio *bio; 60 atomic_t pending_dmas; 61 atomic_t error; 62 unsigned long start_time; 63}; 64 65static struct kmem_cache *bio_meta_pool; 66 67/*----------------- Block Device Operations -----------------*/ 68static 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 85static 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 107static const struct block_device_operations rsxx_fops = { 108 .owner = THIS_MODULE, 109 .getgeo = rsxx_getgeo, 110 .ioctl = rsxx_blkdev_ioctl, 111}; 112 113static void disk_stats_start(struct rsxx_cardinfo *card, struct bio *bio) 114{ 115 generic_start_io_acct(bio_data_dir(bio), bio_sectors(bio), 116 &card->gendisk->part0); 117} 118 119static void disk_stats_complete(struct rsxx_cardinfo *card, 120 struct bio *bio, 121 unsigned long start_time) 122{ 123 generic_end_io_acct(bio_data_dir(bio), &card->gendisk->part0, 124 start_time); 125} 126 127static void bio_dma_done_cb(struct rsxx_cardinfo *card, 128 void *cb_data, 129 unsigned int error) 130{ 131 struct rsxx_bio_meta *meta = cb_data; 132 133 if (error) 134 atomic_set(&meta->error, 1); 135 136 if (atomic_dec_and_test(&meta->pending_dmas)) { 137 if (!card->eeh_state && card->gendisk) 138 disk_stats_complete(card, meta->bio, meta->start_time); 139 140 bio_endio(meta->bio, atomic_read(&meta->error) ? -EIO : 0); 141 kmem_cache_free(bio_meta_pool, meta); 142 } 143} 144 145static void rsxx_make_request(struct request_queue *q, struct bio *bio) 146{ 147 struct rsxx_cardinfo *card = q->queuedata; 148 struct rsxx_bio_meta *bio_meta; 149 int st = -EINVAL; 150 151 might_sleep(); 152 153 if (!card) 154 goto req_err; 155 156 if (bio_end_sector(bio) > get_capacity(card->gendisk)) 157 goto req_err; 158 159 if (unlikely(card->halt)) { 160 st = -EFAULT; 161 goto req_err; 162 } 163 164 if (unlikely(card->dma_fault)) { 165 st = (-EFAULT); 166 goto req_err; 167 } 168 169 if (bio->bi_iter.bi_size == 0) { 170 dev_err(CARD_TO_DEV(card), "size zero BIO!\n"); 171 goto req_err; 172 } 173 174 bio_meta = kmem_cache_alloc(bio_meta_pool, GFP_KERNEL); 175 if (!bio_meta) { 176 st = -ENOMEM; 177 goto req_err; 178 } 179 180 bio_meta->bio = bio; 181 atomic_set(&bio_meta->error, 0); 182 atomic_set(&bio_meta->pending_dmas, 0); 183 bio_meta->start_time = jiffies; 184 185 if (!unlikely(card->halt)) 186 disk_stats_start(card, bio); 187 188 dev_dbg(CARD_TO_DEV(card), "BIO[%c]: meta: %p addr8: x%llx size: %d\n", 189 bio_data_dir(bio) ? 'W' : 'R', bio_meta, 190 (u64)bio->bi_iter.bi_sector << 9, bio->bi_iter.bi_size); 191 192 st = rsxx_dma_queue_bio(card, bio, &bio_meta->pending_dmas, 193 bio_dma_done_cb, bio_meta); 194 if (st) 195 goto queue_err; 196 197 return; 198 199queue_err: 200 kmem_cache_free(bio_meta_pool, bio_meta); 201req_err: 202 bio_endio(bio, st); 203} 204 205/*----------------- Device Setup -------------------*/ 206static bool rsxx_discard_supported(struct rsxx_cardinfo *card) 207{ 208 unsigned char pci_rev; 209 210 pci_read_config_byte(card->dev, PCI_REVISION_ID, &pci_rev); 211 212 return (pci_rev >= RSXX_DISCARD_SUPPORT); 213} 214 215int rsxx_attach_dev(struct rsxx_cardinfo *card) 216{ 217 mutex_lock(&card->dev_lock); 218 219 /* The block device requires the stripe size from the config. */ 220 if (enable_blkdev) { 221 if (card->config_valid) 222 set_capacity(card->gendisk, card->size8 >> 9); 223 else 224 set_capacity(card->gendisk, 0); 225 add_disk(card->gendisk); 226 227 card->bdev_attached = 1; 228 } 229 230 mutex_unlock(&card->dev_lock); 231 232 return 0; 233} 234 235void rsxx_detach_dev(struct rsxx_cardinfo *card) 236{ 237 mutex_lock(&card->dev_lock); 238 239 if (card->bdev_attached) { 240 del_gendisk(card->gendisk); 241 card->bdev_attached = 0; 242 } 243 244 mutex_unlock(&card->dev_lock); 245} 246 247int rsxx_setup_dev(struct rsxx_cardinfo *card) 248{ 249 unsigned short blk_size; 250 251 mutex_init(&card->dev_lock); 252 253 if (!enable_blkdev) 254 return 0; 255 256 card->major = register_blkdev(0, DRIVER_NAME); 257 if (card->major < 0) { 258 dev_err(CARD_TO_DEV(card), "Failed to get major number\n"); 259 return -ENOMEM; 260 } 261 262 card->queue = blk_alloc_queue(GFP_KERNEL); 263 if (!card->queue) { 264 dev_err(CARD_TO_DEV(card), "Failed queue alloc\n"); 265 unregister_blkdev(card->major, DRIVER_NAME); 266 return -ENOMEM; 267 } 268 269 card->gendisk = alloc_disk(blkdev_minors); 270 if (!card->gendisk) { 271 dev_err(CARD_TO_DEV(card), "Failed disk alloc\n"); 272 blk_cleanup_queue(card->queue); 273 unregister_blkdev(card->major, DRIVER_NAME); 274 return -ENOMEM; 275 } 276 277 if (card->config_valid) { 278 blk_size = card->config.data.block_size; 279 blk_queue_dma_alignment(card->queue, blk_size - 1); 280 blk_queue_logical_block_size(card->queue, blk_size); 281 } 282 283 blk_queue_make_request(card->queue, rsxx_make_request); 284 blk_queue_bounce_limit(card->queue, BLK_BOUNCE_ANY); 285 blk_queue_max_hw_sectors(card->queue, blkdev_max_hw_sectors); 286 blk_queue_physical_block_size(card->queue, RSXX_HW_BLK_SIZE); 287 288 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, card->queue); 289 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, card->queue); 290 if (rsxx_discard_supported(card)) { 291 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, card->queue); 292 blk_queue_max_discard_sectors(card->queue, 293 RSXX_HW_BLK_SIZE >> 9); 294 card->queue->limits.discard_granularity = RSXX_HW_BLK_SIZE; 295 card->queue->limits.discard_alignment = RSXX_HW_BLK_SIZE; 296 card->queue->limits.discard_zeroes_data = 1; 297 } 298 299 card->queue->queuedata = card; 300 301 snprintf(card->gendisk->disk_name, sizeof(card->gendisk->disk_name), 302 "rsxx%d", card->disk_id); 303 card->gendisk->driverfs_dev = &card->dev->dev; 304 card->gendisk->major = card->major; 305 card->gendisk->first_minor = 0; 306 card->gendisk->fops = &rsxx_fops; 307 card->gendisk->private_data = card; 308 card->gendisk->queue = card->queue; 309 310 return 0; 311} 312 313void rsxx_destroy_dev(struct rsxx_cardinfo *card) 314{ 315 if (!enable_blkdev) 316 return; 317 318 put_disk(card->gendisk); 319 card->gendisk = NULL; 320 321 blk_cleanup_queue(card->queue); 322 card->queue->queuedata = NULL; 323 unregister_blkdev(card->major, DRIVER_NAME); 324} 325 326int rsxx_dev_init(void) 327{ 328 bio_meta_pool = KMEM_CACHE(rsxx_bio_meta, SLAB_HWCACHE_ALIGN); 329 if (!bio_meta_pool) 330 return -ENOMEM; 331 332 return 0; 333} 334 335void rsxx_dev_cleanup(void) 336{ 337 kmem_cache_destroy(bio_meta_pool); 338} 339 340 341