Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * dcssblk.c -- the S/390 block driver for dcss memory |
| 3 | * |
| 4 | * Authors: Carsten Otte, Stefan Weinhuber, Gerald Schaefer |
| 5 | */ |
| 6 | |
| 7 | #include <linux/module.h> |
| 8 | #include <linux/moduleparam.h> |
| 9 | #include <linux/ctype.h> |
| 10 | #include <linux/errno.h> |
| 11 | #include <linux/init.h> |
| 12 | #include <linux/slab.h> |
| 13 | #include <linux/blkdev.h> |
| 14 | #include <asm/extmem.h> |
| 15 | #include <asm/io.h> |
| 16 | #include <linux/completion.h> |
| 17 | #include <linux/interrupt.h> |
Carsten Otte | cfb1b55 | 2006-01-06 00:19:14 -0800 | [diff] [blame] | 18 | #include <asm/s390_rdev.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | |
| 20 | //#define DCSSBLK_DEBUG /* Debug messages on/off */ |
| 21 | #define DCSSBLK_NAME "dcssblk" |
| 22 | #define DCSSBLK_MINORS_PER_DISK 1 |
| 23 | #define DCSSBLK_PARM_LEN 400 |
| 24 | |
| 25 | #ifdef DCSSBLK_DEBUG |
| 26 | #define PRINT_DEBUG(x...) printk(KERN_DEBUG DCSSBLK_NAME " debug: " x) |
| 27 | #else |
| 28 | #define PRINT_DEBUG(x...) do {} while (0) |
| 29 | #endif |
| 30 | #define PRINT_INFO(x...) printk(KERN_INFO DCSSBLK_NAME " info: " x) |
| 31 | #define PRINT_WARN(x...) printk(KERN_WARNING DCSSBLK_NAME " warning: " x) |
| 32 | #define PRINT_ERR(x...) printk(KERN_ERR DCSSBLK_NAME " error: " x) |
| 33 | |
| 34 | |
| 35 | static int dcssblk_open(struct inode *inode, struct file *filp); |
| 36 | static int dcssblk_release(struct inode *inode, struct file *filp); |
| 37 | static int dcssblk_make_request(struct request_queue *q, struct bio *bio); |
Carsten Otte | 420edbc | 2005-06-23 22:05:23 -0700 | [diff] [blame] | 38 | static int dcssblk_direct_access(struct block_device *bdev, sector_t secnum, |
| 39 | unsigned long *data); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 40 | |
| 41 | static char dcssblk_segments[DCSSBLK_PARM_LEN] = "\0"; |
| 42 | |
| 43 | static int dcssblk_major; |
| 44 | static struct block_device_operations dcssblk_devops = { |
Carsten Otte | 420edbc | 2005-06-23 22:05:23 -0700 | [diff] [blame] | 45 | .owner = THIS_MODULE, |
| 46 | .open = dcssblk_open, |
| 47 | .release = dcssblk_release, |
| 48 | .direct_access = dcssblk_direct_access, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 49 | }; |
| 50 | |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 51 | static ssize_t dcssblk_add_store(struct device * dev, struct device_attribute *attr, const char * buf, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 52 | size_t count); |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 53 | static ssize_t dcssblk_remove_store(struct device * dev, struct device_attribute *attr, const char * buf, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 54 | size_t count); |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 55 | static ssize_t dcssblk_save_store(struct device * dev, struct device_attribute *attr, const char * buf, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | size_t count); |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 57 | static ssize_t dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf); |
| 58 | static ssize_t dcssblk_shared_store(struct device * dev, struct device_attribute *attr, const char * buf, |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 59 | size_t count); |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 60 | static ssize_t dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 61 | |
| 62 | static DEVICE_ATTR(add, S_IWUSR, NULL, dcssblk_add_store); |
| 63 | static DEVICE_ATTR(remove, S_IWUSR, NULL, dcssblk_remove_store); |
| 64 | static DEVICE_ATTR(save, S_IWUSR | S_IRUGO, dcssblk_save_show, |
| 65 | dcssblk_save_store); |
| 66 | static DEVICE_ATTR(shared, S_IWUSR | S_IRUGO, dcssblk_shared_show, |
| 67 | dcssblk_shared_store); |
| 68 | |
| 69 | static struct device *dcssblk_root_dev; |
| 70 | |
| 71 | struct dcssblk_dev_info { |
| 72 | struct list_head lh; |
| 73 | struct device dev; |
| 74 | char segment_name[BUS_ID_SIZE]; |
| 75 | atomic_t use_count; |
| 76 | struct gendisk *gd; |
| 77 | unsigned long start; |
| 78 | unsigned long end; |
| 79 | int segment_type; |
| 80 | unsigned char save_pending; |
| 81 | unsigned char is_shared; |
| 82 | struct request_queue *dcssblk_queue; |
| 83 | }; |
| 84 | |
| 85 | static struct list_head dcssblk_devices = LIST_HEAD_INIT(dcssblk_devices); |
| 86 | static struct rw_semaphore dcssblk_devices_sem; |
| 87 | |
| 88 | /* |
| 89 | * release function for segment device. |
| 90 | */ |
| 91 | static void |
| 92 | dcssblk_release_segment(struct device *dev) |
| 93 | { |
| 94 | PRINT_DEBUG("segment release fn called for %s\n", dev->bus_id); |
| 95 | kfree(container_of(dev, struct dcssblk_dev_info, dev)); |
| 96 | module_put(THIS_MODULE); |
| 97 | } |
| 98 | |
| 99 | /* |
| 100 | * get a minor number. needs to be called with |
| 101 | * down_write(&dcssblk_devices_sem) and the |
| 102 | * device needs to be enqueued before the semaphore is |
| 103 | * freed. |
| 104 | */ |
Heiko Carstens | 4d284ca | 2007-02-05 21:18:53 +0100 | [diff] [blame] | 105 | static int |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 106 | dcssblk_assign_free_minor(struct dcssblk_dev_info *dev_info) |
| 107 | { |
| 108 | int minor, found; |
| 109 | struct dcssblk_dev_info *entry; |
| 110 | |
| 111 | if (dev_info == NULL) |
| 112 | return -EINVAL; |
| 113 | for (minor = 0; minor < (1<<MINORBITS); minor++) { |
| 114 | found = 0; |
| 115 | // test if minor available |
| 116 | list_for_each_entry(entry, &dcssblk_devices, lh) |
| 117 | if (minor == entry->gd->first_minor) |
| 118 | found++; |
| 119 | if (!found) break; // got unused minor |
| 120 | } |
| 121 | if (found) |
| 122 | return -EBUSY; |
| 123 | dev_info->gd->first_minor = minor; |
| 124 | return 0; |
| 125 | } |
| 126 | |
| 127 | /* |
| 128 | * get the struct dcssblk_dev_info from dcssblk_devices |
| 129 | * for the given name. |
| 130 | * down_read(&dcssblk_devices_sem) must be held. |
| 131 | */ |
| 132 | static struct dcssblk_dev_info * |
| 133 | dcssblk_get_device_by_name(char *name) |
| 134 | { |
| 135 | struct dcssblk_dev_info *entry; |
| 136 | |
| 137 | list_for_each_entry(entry, &dcssblk_devices, lh) { |
| 138 | if (!strcmp(name, entry->segment_name)) { |
| 139 | return entry; |
| 140 | } |
| 141 | } |
| 142 | return NULL; |
| 143 | } |
| 144 | |
| 145 | /* |
| 146 | * print appropriate error message for segment_load()/segment_type() |
| 147 | * return code |
| 148 | */ |
| 149 | static void |
| 150 | dcssblk_segment_warn(int rc, char* seg_name) |
| 151 | { |
| 152 | switch (rc) { |
| 153 | case -ENOENT: |
| 154 | PRINT_WARN("cannot load/query segment %s, does not exist\n", |
| 155 | seg_name); |
| 156 | break; |
| 157 | case -ENOSYS: |
| 158 | PRINT_WARN("cannot load/query segment %s, not running on VM\n", |
| 159 | seg_name); |
| 160 | break; |
| 161 | case -EIO: |
| 162 | PRINT_WARN("cannot load/query segment %s, hardware error\n", |
| 163 | seg_name); |
| 164 | break; |
| 165 | case -ENOTSUPP: |
| 166 | PRINT_WARN("cannot load/query segment %s, is a multi-part " |
| 167 | "segment\n", seg_name); |
| 168 | break; |
| 169 | case -ENOSPC: |
| 170 | PRINT_WARN("cannot load/query segment %s, overlaps with " |
| 171 | "storage\n", seg_name); |
| 172 | break; |
| 173 | case -EBUSY: |
| 174 | PRINT_WARN("cannot load/query segment %s, overlaps with " |
| 175 | "already loaded dcss\n", seg_name); |
| 176 | break; |
| 177 | case -EPERM: |
| 178 | PRINT_WARN("cannot load/query segment %s, already loaded in " |
| 179 | "incompatible mode\n", seg_name); |
| 180 | break; |
| 181 | case -ENOMEM: |
| 182 | PRINT_WARN("cannot load/query segment %s, out of memory\n", |
| 183 | seg_name); |
| 184 | break; |
| 185 | case -ERANGE: |
| 186 | PRINT_WARN("cannot load/query segment %s, exceeds kernel " |
| 187 | "mapping range\n", seg_name); |
| 188 | break; |
| 189 | default: |
| 190 | PRINT_WARN("cannot load/query segment %s, return value %i\n", |
| 191 | seg_name, rc); |
| 192 | break; |
| 193 | } |
| 194 | } |
| 195 | |
| 196 | /* |
| 197 | * device attribute for switching shared/nonshared (exclusive) |
| 198 | * operation (show + store) |
| 199 | */ |
| 200 | static ssize_t |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 201 | dcssblk_shared_show(struct device *dev, struct device_attribute *attr, char *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 202 | { |
| 203 | struct dcssblk_dev_info *dev_info; |
| 204 | |
| 205 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| 206 | return sprintf(buf, dev_info->is_shared ? "1\n" : "0\n"); |
| 207 | } |
| 208 | |
| 209 | static ssize_t |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 210 | dcssblk_shared_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 211 | { |
| 212 | struct dcssblk_dev_info *dev_info; |
| 213 | int rc; |
| 214 | |
| 215 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { |
| 216 | PRINT_WARN("Invalid value, must be 0 or 1\n"); |
| 217 | return -EINVAL; |
| 218 | } |
| 219 | down_write(&dcssblk_devices_sem); |
| 220 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| 221 | if (atomic_read(&dev_info->use_count)) { |
| 222 | PRINT_ERR("share: segment %s is busy!\n", |
| 223 | dev_info->segment_name); |
| 224 | rc = -EBUSY; |
| 225 | goto out; |
| 226 | } |
| 227 | if (inbuf[0] == '1') { |
| 228 | // reload segment in shared mode |
| 229 | rc = segment_modify_shared(dev_info->segment_name, |
| 230 | SEGMENT_SHARED); |
| 231 | if (rc < 0) { |
| 232 | BUG_ON(rc == -EINVAL); |
Gerald Schaefer | 444f0e5 | 2007-02-05 21:17:11 +0100 | [diff] [blame] | 233 | if (rc != -EAGAIN) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 234 | goto removeseg; |
| 235 | } else { |
| 236 | dev_info->is_shared = 1; |
| 237 | switch (dev_info->segment_type) { |
| 238 | case SEG_TYPE_SR: |
| 239 | case SEG_TYPE_ER: |
| 240 | case SEG_TYPE_SC: |
| 241 | set_disk_ro(dev_info->gd,1); |
| 242 | } |
| 243 | } |
| 244 | } else if (inbuf[0] == '0') { |
| 245 | // reload segment in exclusive mode |
| 246 | if (dev_info->segment_type == SEG_TYPE_SC) { |
| 247 | PRINT_ERR("Segment type SC (%s) cannot be loaded in " |
| 248 | "non-shared mode\n", dev_info->segment_name); |
| 249 | rc = -EINVAL; |
| 250 | goto out; |
| 251 | } |
| 252 | rc = segment_modify_shared(dev_info->segment_name, |
| 253 | SEGMENT_EXCLUSIVE); |
| 254 | if (rc < 0) { |
| 255 | BUG_ON(rc == -EINVAL); |
Gerald Schaefer | 444f0e5 | 2007-02-05 21:17:11 +0100 | [diff] [blame] | 256 | if (rc != -EAGAIN) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 257 | goto removeseg; |
| 258 | } else { |
| 259 | dev_info->is_shared = 0; |
| 260 | set_disk_ro(dev_info->gd, 0); |
| 261 | } |
| 262 | } else { |
| 263 | PRINT_WARN("Invalid value, must be 0 or 1\n"); |
| 264 | rc = -EINVAL; |
| 265 | goto out; |
| 266 | } |
| 267 | rc = count; |
| 268 | goto out; |
| 269 | |
| 270 | removeseg: |
| 271 | PRINT_ERR("Could not reload segment %s, removing it now!\n", |
| 272 | dev_info->segment_name); |
| 273 | list_del(&dev_info->lh); |
| 274 | |
| 275 | del_gendisk(dev_info->gd); |
Al Viro | 1312f40 | 2006-03-12 11:02:03 -0500 | [diff] [blame] | 276 | blk_cleanup_queue(dev_info->dcssblk_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 277 | dev_info->gd->queue = NULL; |
| 278 | put_disk(dev_info->gd); |
| 279 | device_unregister(dev); |
| 280 | put_device(dev); |
| 281 | out: |
| 282 | up_write(&dcssblk_devices_sem); |
| 283 | return rc; |
| 284 | } |
| 285 | |
| 286 | /* |
| 287 | * device attribute for save operation on current copy |
| 288 | * of the segment. If the segment is busy, saving will |
| 289 | * become pending until it gets released, which can be |
| 290 | * undone by storing a non-true value to this entry. |
| 291 | * (show + store) |
| 292 | */ |
| 293 | static ssize_t |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 294 | dcssblk_save_show(struct device *dev, struct device_attribute *attr, char *buf) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 295 | { |
| 296 | struct dcssblk_dev_info *dev_info; |
| 297 | |
| 298 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| 299 | return sprintf(buf, dev_info->save_pending ? "1\n" : "0\n"); |
| 300 | } |
| 301 | |
| 302 | static ssize_t |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 303 | dcssblk_save_store(struct device *dev, struct device_attribute *attr, const char *inbuf, size_t count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 304 | { |
| 305 | struct dcssblk_dev_info *dev_info; |
| 306 | |
| 307 | if ((count > 1) && (inbuf[1] != '\n') && (inbuf[1] != '\0')) { |
| 308 | PRINT_WARN("Invalid value, must be 0 or 1\n"); |
| 309 | return -EINVAL; |
| 310 | } |
| 311 | dev_info = container_of(dev, struct dcssblk_dev_info, dev); |
| 312 | |
| 313 | down_write(&dcssblk_devices_sem); |
| 314 | if (inbuf[0] == '1') { |
| 315 | if (atomic_read(&dev_info->use_count) == 0) { |
| 316 | // device is idle => we save immediately |
| 317 | PRINT_INFO("Saving segment %s\n", |
| 318 | dev_info->segment_name); |
| 319 | segment_save(dev_info->segment_name); |
| 320 | } else { |
| 321 | // device is busy => we save it when it becomes |
| 322 | // idle in dcssblk_release |
| 323 | PRINT_INFO("Segment %s is currently busy, it will " |
| 324 | "be saved when it becomes idle...\n", |
| 325 | dev_info->segment_name); |
| 326 | dev_info->save_pending = 1; |
| 327 | } |
| 328 | } else if (inbuf[0] == '0') { |
| 329 | if (dev_info->save_pending) { |
| 330 | // device is busy & the user wants to undo his save |
| 331 | // request |
| 332 | dev_info->save_pending = 0; |
| 333 | PRINT_INFO("Pending save for segment %s deactivated\n", |
| 334 | dev_info->segment_name); |
| 335 | } |
| 336 | } else { |
| 337 | up_write(&dcssblk_devices_sem); |
| 338 | PRINT_WARN("Invalid value, must be 0 or 1\n"); |
| 339 | return -EINVAL; |
| 340 | } |
| 341 | up_write(&dcssblk_devices_sem); |
| 342 | return count; |
| 343 | } |
| 344 | |
| 345 | /* |
| 346 | * device attribute for adding devices |
| 347 | */ |
| 348 | static ssize_t |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 349 | dcssblk_add_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 350 | { |
| 351 | int rc, i; |
| 352 | struct dcssblk_dev_info *dev_info; |
| 353 | char *local_buf; |
| 354 | unsigned long seg_byte_size; |
| 355 | |
| 356 | dev_info = NULL; |
| 357 | if (dev != dcssblk_root_dev) { |
| 358 | rc = -EINVAL; |
| 359 | goto out_nobuf; |
| 360 | } |
| 361 | local_buf = kmalloc(count + 1, GFP_KERNEL); |
| 362 | if (local_buf == NULL) { |
| 363 | rc = -ENOMEM; |
| 364 | goto out_nobuf; |
| 365 | } |
| 366 | /* |
| 367 | * parse input |
| 368 | */ |
| 369 | for (i = 0; ((buf[i] != '\0') && (buf[i] != '\n') && i < count); i++) { |
| 370 | local_buf[i] = toupper(buf[i]); |
| 371 | } |
| 372 | local_buf[i] = '\0'; |
| 373 | if ((i == 0) || (i > 8)) { |
| 374 | rc = -ENAMETOOLONG; |
| 375 | goto out; |
| 376 | } |
| 377 | /* |
| 378 | * already loaded? |
| 379 | */ |
| 380 | down_read(&dcssblk_devices_sem); |
| 381 | dev_info = dcssblk_get_device_by_name(local_buf); |
| 382 | up_read(&dcssblk_devices_sem); |
| 383 | if (dev_info != NULL) { |
| 384 | PRINT_WARN("Segment %s already loaded!\n", local_buf); |
| 385 | rc = -EEXIST; |
| 386 | goto out; |
| 387 | } |
| 388 | /* |
| 389 | * get a struct dcssblk_dev_info |
| 390 | */ |
Eric Sesterhenn | 88abaab | 2006-03-24 03:15:31 -0800 | [diff] [blame] | 391 | dev_info = kzalloc(sizeof(struct dcssblk_dev_info), GFP_KERNEL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 392 | if (dev_info == NULL) { |
| 393 | rc = -ENOMEM; |
| 394 | goto out; |
| 395 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 396 | |
| 397 | strcpy(dev_info->segment_name, local_buf); |
| 398 | strlcpy(dev_info->dev.bus_id, local_buf, BUS_ID_SIZE); |
| 399 | dev_info->dev.release = dcssblk_release_segment; |
| 400 | INIT_LIST_HEAD(&dev_info->lh); |
| 401 | |
| 402 | dev_info->gd = alloc_disk(DCSSBLK_MINORS_PER_DISK); |
| 403 | if (dev_info->gd == NULL) { |
| 404 | rc = -ENOMEM; |
| 405 | goto free_dev_info; |
| 406 | } |
| 407 | dev_info->gd->major = dcssblk_major; |
| 408 | dev_info->gd->fops = &dcssblk_devops; |
| 409 | dev_info->dcssblk_queue = blk_alloc_queue(GFP_KERNEL); |
| 410 | dev_info->gd->queue = dev_info->dcssblk_queue; |
| 411 | dev_info->gd->private_data = dev_info; |
| 412 | dev_info->gd->driverfs_dev = &dev_info->dev; |
| 413 | /* |
| 414 | * load the segment |
| 415 | */ |
| 416 | rc = segment_load(local_buf, SEGMENT_SHARED, |
| 417 | &dev_info->start, &dev_info->end); |
| 418 | if (rc < 0) { |
| 419 | dcssblk_segment_warn(rc, dev_info->segment_name); |
| 420 | goto dealloc_gendisk; |
| 421 | } |
| 422 | seg_byte_size = (dev_info->end - dev_info->start + 1); |
| 423 | set_capacity(dev_info->gd, seg_byte_size >> 9); // size in sectors |
| 424 | PRINT_INFO("Loaded segment %s, size = %lu Byte, " |
| 425 | "capacity = %lu (512 Byte) sectors\n", local_buf, |
| 426 | seg_byte_size, seg_byte_size >> 9); |
| 427 | |
| 428 | dev_info->segment_type = rc; |
| 429 | dev_info->save_pending = 0; |
| 430 | dev_info->is_shared = 1; |
| 431 | dev_info->dev.parent = dcssblk_root_dev; |
| 432 | |
| 433 | /* |
| 434 | * get minor, add to list |
| 435 | */ |
| 436 | down_write(&dcssblk_devices_sem); |
| 437 | rc = dcssblk_assign_free_minor(dev_info); |
| 438 | if (rc) { |
| 439 | up_write(&dcssblk_devices_sem); |
| 440 | PRINT_ERR("No free minor number available! " |
| 441 | "Unloading segment...\n"); |
| 442 | goto unload_seg; |
| 443 | } |
| 444 | sprintf(dev_info->gd->disk_name, "dcssblk%d", |
| 445 | dev_info->gd->first_minor); |
| 446 | list_add_tail(&dev_info->lh, &dcssblk_devices); |
| 447 | |
| 448 | if (!try_module_get(THIS_MODULE)) { |
| 449 | rc = -ENODEV; |
| 450 | goto list_del; |
| 451 | } |
| 452 | /* |
| 453 | * register the device |
| 454 | */ |
| 455 | rc = device_register(&dev_info->dev); |
| 456 | if (rc) { |
| 457 | PRINT_ERR("Segment %s could not be registered RC=%d\n", |
| 458 | local_buf, rc); |
| 459 | module_put(THIS_MODULE); |
| 460 | goto list_del; |
| 461 | } |
| 462 | get_device(&dev_info->dev); |
| 463 | rc = device_create_file(&dev_info->dev, &dev_attr_shared); |
| 464 | if (rc) |
| 465 | goto unregister_dev; |
| 466 | rc = device_create_file(&dev_info->dev, &dev_attr_save); |
| 467 | if (rc) |
| 468 | goto unregister_dev; |
| 469 | |
| 470 | add_disk(dev_info->gd); |
| 471 | |
| 472 | blk_queue_make_request(dev_info->dcssblk_queue, dcssblk_make_request); |
| 473 | blk_queue_hardsect_size(dev_info->dcssblk_queue, 4096); |
| 474 | |
| 475 | switch (dev_info->segment_type) { |
| 476 | case SEG_TYPE_SR: |
| 477 | case SEG_TYPE_ER: |
| 478 | case SEG_TYPE_SC: |
| 479 | set_disk_ro(dev_info->gd,1); |
| 480 | break; |
| 481 | default: |
| 482 | set_disk_ro(dev_info->gd,0); |
| 483 | break; |
| 484 | } |
| 485 | PRINT_DEBUG("Segment %s loaded successfully\n", local_buf); |
| 486 | up_write(&dcssblk_devices_sem); |
| 487 | rc = count; |
| 488 | goto out; |
| 489 | |
| 490 | unregister_dev: |
| 491 | PRINT_ERR("device_create_file() failed!\n"); |
| 492 | list_del(&dev_info->lh); |
Al Viro | 1312f40 | 2006-03-12 11:02:03 -0500 | [diff] [blame] | 493 | blk_cleanup_queue(dev_info->dcssblk_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 494 | dev_info->gd->queue = NULL; |
| 495 | put_disk(dev_info->gd); |
| 496 | device_unregister(&dev_info->dev); |
| 497 | segment_unload(dev_info->segment_name); |
| 498 | put_device(&dev_info->dev); |
| 499 | up_write(&dcssblk_devices_sem); |
| 500 | goto out; |
| 501 | list_del: |
| 502 | list_del(&dev_info->lh); |
| 503 | up_write(&dcssblk_devices_sem); |
| 504 | unload_seg: |
| 505 | segment_unload(local_buf); |
| 506 | dealloc_gendisk: |
Al Viro | 1312f40 | 2006-03-12 11:02:03 -0500 | [diff] [blame] | 507 | blk_cleanup_queue(dev_info->dcssblk_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 508 | dev_info->gd->queue = NULL; |
| 509 | put_disk(dev_info->gd); |
| 510 | free_dev_info: |
| 511 | kfree(dev_info); |
| 512 | out: |
| 513 | kfree(local_buf); |
| 514 | out_nobuf: |
| 515 | return rc; |
| 516 | } |
| 517 | |
| 518 | /* |
| 519 | * device attribute for removing devices |
| 520 | */ |
| 521 | static ssize_t |
Yani Ioannou | e404e27 | 2005-05-17 06:42:58 -0400 | [diff] [blame] | 522 | dcssblk_remove_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 523 | { |
| 524 | struct dcssblk_dev_info *dev_info; |
| 525 | int rc, i; |
| 526 | char *local_buf; |
| 527 | |
| 528 | if (dev != dcssblk_root_dev) { |
| 529 | return -EINVAL; |
| 530 | } |
| 531 | local_buf = kmalloc(count + 1, GFP_KERNEL); |
| 532 | if (local_buf == NULL) { |
| 533 | return -ENOMEM; |
| 534 | } |
| 535 | /* |
| 536 | * parse input |
| 537 | */ |
| 538 | for (i = 0; ((*(buf+i)!='\0') && (*(buf+i)!='\n') && i < count); i++) { |
| 539 | local_buf[i] = toupper(buf[i]); |
| 540 | } |
| 541 | local_buf[i] = '\0'; |
| 542 | if ((i == 0) || (i > 8)) { |
| 543 | rc = -ENAMETOOLONG; |
| 544 | goto out_buf; |
| 545 | } |
| 546 | |
| 547 | down_write(&dcssblk_devices_sem); |
| 548 | dev_info = dcssblk_get_device_by_name(local_buf); |
| 549 | if (dev_info == NULL) { |
| 550 | up_write(&dcssblk_devices_sem); |
| 551 | PRINT_WARN("Segment %s is not loaded!\n", local_buf); |
| 552 | rc = -ENODEV; |
| 553 | goto out_buf; |
| 554 | } |
| 555 | if (atomic_read(&dev_info->use_count) != 0) { |
| 556 | up_write(&dcssblk_devices_sem); |
| 557 | PRINT_WARN("Segment %s is in use!\n", local_buf); |
| 558 | rc = -EBUSY; |
| 559 | goto out_buf; |
| 560 | } |
| 561 | list_del(&dev_info->lh); |
| 562 | |
| 563 | del_gendisk(dev_info->gd); |
Al Viro | 1312f40 | 2006-03-12 11:02:03 -0500 | [diff] [blame] | 564 | blk_cleanup_queue(dev_info->dcssblk_queue); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 565 | dev_info->gd->queue = NULL; |
| 566 | put_disk(dev_info->gd); |
| 567 | device_unregister(&dev_info->dev); |
| 568 | segment_unload(dev_info->segment_name); |
| 569 | PRINT_DEBUG("Segment %s unloaded successfully\n", |
| 570 | dev_info->segment_name); |
| 571 | put_device(&dev_info->dev); |
| 572 | up_write(&dcssblk_devices_sem); |
| 573 | |
| 574 | rc = count; |
| 575 | out_buf: |
| 576 | kfree(local_buf); |
| 577 | return rc; |
| 578 | } |
| 579 | |
| 580 | static int |
| 581 | dcssblk_open(struct inode *inode, struct file *filp) |
| 582 | { |
| 583 | struct dcssblk_dev_info *dev_info; |
| 584 | int rc; |
| 585 | |
| 586 | dev_info = inode->i_bdev->bd_disk->private_data; |
| 587 | if (NULL == dev_info) { |
| 588 | rc = -ENODEV; |
| 589 | goto out; |
| 590 | } |
| 591 | atomic_inc(&dev_info->use_count); |
| 592 | inode->i_bdev->bd_block_size = 4096; |
| 593 | rc = 0; |
| 594 | out: |
| 595 | return rc; |
| 596 | } |
| 597 | |
| 598 | static int |
| 599 | dcssblk_release(struct inode *inode, struct file *filp) |
| 600 | { |
| 601 | struct dcssblk_dev_info *dev_info; |
| 602 | int rc; |
| 603 | |
| 604 | dev_info = inode->i_bdev->bd_disk->private_data; |
| 605 | if (NULL == dev_info) { |
| 606 | rc = -ENODEV; |
| 607 | goto out; |
| 608 | } |
| 609 | down_write(&dcssblk_devices_sem); |
| 610 | if (atomic_dec_and_test(&dev_info->use_count) |
| 611 | && (dev_info->save_pending)) { |
| 612 | PRINT_INFO("Segment %s became idle and is being saved now\n", |
| 613 | dev_info->segment_name); |
| 614 | segment_save(dev_info->segment_name); |
| 615 | dev_info->save_pending = 0; |
| 616 | } |
| 617 | up_write(&dcssblk_devices_sem); |
| 618 | rc = 0; |
| 619 | out: |
| 620 | return rc; |
| 621 | } |
| 622 | |
| 623 | static int |
| 624 | dcssblk_make_request(request_queue_t *q, struct bio *bio) |
| 625 | { |
| 626 | struct dcssblk_dev_info *dev_info; |
| 627 | struct bio_vec *bvec; |
| 628 | unsigned long index; |
| 629 | unsigned long page_addr; |
| 630 | unsigned long source_addr; |
| 631 | unsigned long bytes_done; |
| 632 | int i; |
| 633 | |
| 634 | bytes_done = 0; |
| 635 | dev_info = bio->bi_bdev->bd_disk->private_data; |
| 636 | if (dev_info == NULL) |
| 637 | goto fail; |
| 638 | if ((bio->bi_sector & 7) != 0 || (bio->bi_size & 4095) != 0) |
| 639 | /* Request is not page-aligned. */ |
| 640 | goto fail; |
| 641 | if (((bio->bi_size >> 9) + bio->bi_sector) |
| 642 | > get_capacity(bio->bi_bdev->bd_disk)) { |
| 643 | /* Request beyond end of DCSS segment. */ |
| 644 | goto fail; |
| 645 | } |
Carsten Otte | 420edbc | 2005-06-23 22:05:23 -0700 | [diff] [blame] | 646 | /* verify data transfer direction */ |
| 647 | if (dev_info->is_shared) { |
| 648 | switch (dev_info->segment_type) { |
| 649 | case SEG_TYPE_SR: |
| 650 | case SEG_TYPE_ER: |
| 651 | case SEG_TYPE_SC: |
| 652 | /* cannot write to these segments */ |
| 653 | if (bio_data_dir(bio) == WRITE) { |
| 654 | PRINT_WARN("rejecting write to ro segment %s\n", dev_info->dev.bus_id); |
| 655 | goto fail; |
| 656 | } |
| 657 | } |
| 658 | } |
| 659 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 660 | index = (bio->bi_sector >> 3); |
| 661 | bio_for_each_segment(bvec, bio, i) { |
| 662 | page_addr = (unsigned long) |
| 663 | page_address(bvec->bv_page) + bvec->bv_offset; |
| 664 | source_addr = dev_info->start + (index<<12) + bytes_done; |
| 665 | if (unlikely(page_addr & 4095) != 0 || (bvec->bv_len & 4095) != 0) |
| 666 | // More paranoia. |
| 667 | goto fail; |
| 668 | if (bio_data_dir(bio) == READ) { |
| 669 | memcpy((void*)page_addr, (void*)source_addr, |
| 670 | bvec->bv_len); |
| 671 | } else { |
| 672 | memcpy((void*)source_addr, (void*)page_addr, |
| 673 | bvec->bv_len); |
| 674 | } |
| 675 | bytes_done += bvec->bv_len; |
| 676 | } |
| 677 | bio_endio(bio, bytes_done, 0); |
| 678 | return 0; |
| 679 | fail: |
Carsten Otte | 420edbc | 2005-06-23 22:05:23 -0700 | [diff] [blame] | 680 | bio_io_error(bio, bio->bi_size); |
| 681 | return 0; |
| 682 | } |
| 683 | |
| 684 | static int |
| 685 | dcssblk_direct_access (struct block_device *bdev, sector_t secnum, |
| 686 | unsigned long *data) |
| 687 | { |
| 688 | struct dcssblk_dev_info *dev_info; |
| 689 | unsigned long pgoff; |
| 690 | |
| 691 | dev_info = bdev->bd_disk->private_data; |
| 692 | if (!dev_info) |
| 693 | return -ENODEV; |
| 694 | if (secnum % (PAGE_SIZE/512)) |
| 695 | return -EINVAL; |
| 696 | pgoff = secnum / (PAGE_SIZE / 512); |
| 697 | if ((pgoff+1)*PAGE_SIZE-1 > dev_info->end - dev_info->start) |
| 698 | return -ERANGE; |
| 699 | *data = (unsigned long) (dev_info->start+pgoff*PAGE_SIZE); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | return 0; |
| 701 | } |
| 702 | |
| 703 | static void |
| 704 | dcssblk_check_params(void) |
| 705 | { |
| 706 | int rc, i, j, k; |
| 707 | char buf[9]; |
| 708 | struct dcssblk_dev_info *dev_info; |
| 709 | |
| 710 | for (i = 0; (i < DCSSBLK_PARM_LEN) && (dcssblk_segments[i] != '\0'); |
| 711 | i++) { |
| 712 | for (j = i; (dcssblk_segments[j] != ',') && |
| 713 | (dcssblk_segments[j] != '\0') && |
| 714 | (dcssblk_segments[j] != '(') && |
| 715 | (j - i) < 8; j++) |
| 716 | { |
| 717 | buf[j-i] = dcssblk_segments[j]; |
| 718 | } |
| 719 | buf[j-i] = '\0'; |
Cornelia Huck | f901e5d | 2005-06-25 14:55:29 -0700 | [diff] [blame] | 720 | rc = dcssblk_add_store(dcssblk_root_dev, NULL, buf, j-i); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 721 | if ((rc >= 0) && (dcssblk_segments[j] == '(')) { |
| 722 | for (k = 0; buf[k] != '\0'; k++) |
| 723 | buf[k] = toupper(buf[k]); |
| 724 | if (!strncmp(&dcssblk_segments[j], "(local)", 7)) { |
| 725 | down_read(&dcssblk_devices_sem); |
| 726 | dev_info = dcssblk_get_device_by_name(buf); |
| 727 | up_read(&dcssblk_devices_sem); |
| 728 | if (dev_info) |
| 729 | dcssblk_shared_store(&dev_info->dev, |
Cornelia Huck | f901e5d | 2005-06-25 14:55:29 -0700 | [diff] [blame] | 730 | NULL, "0\n", 2); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 731 | } |
| 732 | } |
| 733 | while ((dcssblk_segments[j] != ',') && |
| 734 | (dcssblk_segments[j] != '\0')) |
| 735 | { |
| 736 | j++; |
| 737 | } |
| 738 | if (dcssblk_segments[j] == '\0') |
| 739 | break; |
| 740 | i = j; |
| 741 | } |
| 742 | } |
| 743 | |
| 744 | /* |
| 745 | * The init/exit functions. |
| 746 | */ |
| 747 | static void __exit |
| 748 | dcssblk_exit(void) |
| 749 | { |
| 750 | int rc; |
| 751 | |
| 752 | PRINT_DEBUG("DCSSBLOCK EXIT...\n"); |
| 753 | s390_root_dev_unregister(dcssblk_root_dev); |
| 754 | rc = unregister_blkdev(dcssblk_major, DCSSBLK_NAME); |
| 755 | if (rc) { |
| 756 | PRINT_ERR("unregister_blkdev() failed!\n"); |
| 757 | } |
| 758 | PRINT_DEBUG("...finished!\n"); |
| 759 | } |
| 760 | |
| 761 | static int __init |
| 762 | dcssblk_init(void) |
| 763 | { |
| 764 | int rc; |
| 765 | |
| 766 | PRINT_DEBUG("DCSSBLOCK INIT...\n"); |
| 767 | dcssblk_root_dev = s390_root_dev_register("dcssblk"); |
| 768 | if (IS_ERR(dcssblk_root_dev)) { |
| 769 | PRINT_ERR("device_register() failed!\n"); |
| 770 | return PTR_ERR(dcssblk_root_dev); |
| 771 | } |
| 772 | rc = device_create_file(dcssblk_root_dev, &dev_attr_add); |
| 773 | if (rc) { |
| 774 | PRINT_ERR("device_create_file(add) failed!\n"); |
| 775 | s390_root_dev_unregister(dcssblk_root_dev); |
| 776 | return rc; |
| 777 | } |
| 778 | rc = device_create_file(dcssblk_root_dev, &dev_attr_remove); |
| 779 | if (rc) { |
| 780 | PRINT_ERR("device_create_file(remove) failed!\n"); |
| 781 | s390_root_dev_unregister(dcssblk_root_dev); |
| 782 | return rc; |
| 783 | } |
| 784 | rc = register_blkdev(0, DCSSBLK_NAME); |
| 785 | if (rc < 0) { |
| 786 | PRINT_ERR("Can't get dynamic major!\n"); |
| 787 | s390_root_dev_unregister(dcssblk_root_dev); |
| 788 | return rc; |
| 789 | } |
| 790 | dcssblk_major = rc; |
| 791 | init_rwsem(&dcssblk_devices_sem); |
| 792 | |
| 793 | dcssblk_check_params(); |
| 794 | |
| 795 | PRINT_DEBUG("...finished!\n"); |
| 796 | return 0; |
| 797 | } |
| 798 | |
| 799 | module_init(dcssblk_init); |
| 800 | module_exit(dcssblk_exit); |
| 801 | |
| 802 | module_param_string(segments, dcssblk_segments, DCSSBLK_PARM_LEN, 0444); |
| 803 | MODULE_PARM_DESC(segments, "Name of DCSS segment(s) to be loaded, " |
| 804 | "comma-separated list, each name max. 8 chars.\n" |
| 805 | "Adding \"(local)\" to segment name equals echoing 0 to " |
| 806 | "/sys/devices/dcssblk/<segment name>/shared after loading " |
| 807 | "the segment - \n" |
| 808 | "e.g. segments=\"mydcss1,mydcss2,mydcss3(local)\""); |
| 809 | |
| 810 | MODULE_LICENSE("GPL"); |