| 1 | /* |
| 2 | * Memory subsystem support |
| 3 | * |
| 4 | * Written by Matt Tolentino <matthew.e.tolentino@intel.com> |
| 5 | * Dave Hansen <haveblue@us.ibm.com> |
| 6 | * |
| 7 | * This file provides the necessary infrastructure to represent |
| 8 | * a SPARSEMEM-memory-model system's physical memory in /sysfs. |
| 9 | * All arch-independent code that assumes MEMORY_HOTPLUG requires |
| 10 | * SPARSEMEM should be contained here, or in mm/memory_hotplug.c. |
| 11 | */ |
| 12 | |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/init.h> |
| 15 | #include <linux/topology.h> |
| 16 | #include <linux/capability.h> |
| 17 | #include <linux/device.h> |
| 18 | #include <linux/memory.h> |
| 19 | #include <linux/kobject.h> |
| 20 | #include <linux/memory_hotplug.h> |
| 21 | #include <linux/mm.h> |
| 22 | #include <linux/mutex.h> |
| 23 | #include <linux/stat.h> |
| 24 | #include <linux/slab.h> |
| 25 | |
| 26 | #include <linux/atomic.h> |
| 27 | #include <asm/uaccess.h> |
| 28 | |
| 29 | static DEFINE_MUTEX(mem_sysfs_mutex); |
| 30 | |
| 31 | #define MEMORY_CLASS_NAME "memory" |
| 32 | |
| 33 | static int sections_per_block; |
| 34 | |
| 35 | static inline int base_memory_block_id(int section_nr) |
| 36 | { |
| 37 | return section_nr / sections_per_block; |
| 38 | } |
| 39 | |
| 40 | static struct bus_type memory_subsys = { |
| 41 | .name = MEMORY_CLASS_NAME, |
| 42 | .dev_name = MEMORY_CLASS_NAME, |
| 43 | }; |
| 44 | |
| 45 | static BLOCKING_NOTIFIER_HEAD(memory_chain); |
| 46 | |
| 47 | int register_memory_notifier(struct notifier_block *nb) |
| 48 | { |
| 49 | return blocking_notifier_chain_register(&memory_chain, nb); |
| 50 | } |
| 51 | EXPORT_SYMBOL(register_memory_notifier); |
| 52 | |
| 53 | void unregister_memory_notifier(struct notifier_block *nb) |
| 54 | { |
| 55 | blocking_notifier_chain_unregister(&memory_chain, nb); |
| 56 | } |
| 57 | EXPORT_SYMBOL(unregister_memory_notifier); |
| 58 | |
| 59 | static ATOMIC_NOTIFIER_HEAD(memory_isolate_chain); |
| 60 | |
| 61 | int register_memory_isolate_notifier(struct notifier_block *nb) |
| 62 | { |
| 63 | return atomic_notifier_chain_register(&memory_isolate_chain, nb); |
| 64 | } |
| 65 | EXPORT_SYMBOL(register_memory_isolate_notifier); |
| 66 | |
| 67 | void unregister_memory_isolate_notifier(struct notifier_block *nb) |
| 68 | { |
| 69 | atomic_notifier_chain_unregister(&memory_isolate_chain, nb); |
| 70 | } |
| 71 | EXPORT_SYMBOL(unregister_memory_isolate_notifier); |
| 72 | |
| 73 | /* |
| 74 | * register_memory - Setup a sysfs device for a memory block |
| 75 | */ |
| 76 | static |
| 77 | int register_memory(struct memory_block *memory) |
| 78 | { |
| 79 | int error; |
| 80 | |
| 81 | memory->dev.bus = &memory_subsys; |
| 82 | memory->dev.id = memory->start_section_nr / sections_per_block; |
| 83 | |
| 84 | error = device_register(&memory->dev); |
| 85 | return error; |
| 86 | } |
| 87 | |
| 88 | static void |
| 89 | unregister_memory(struct memory_block *memory) |
| 90 | { |
| 91 | BUG_ON(memory->dev.bus != &memory_subsys); |
| 92 | |
| 93 | /* drop the ref. we got in remove_memory_block() */ |
| 94 | kobject_put(&memory->dev.kobj); |
| 95 | device_unregister(&memory->dev); |
| 96 | } |
| 97 | |
| 98 | unsigned long __weak memory_block_size_bytes(void) |
| 99 | { |
| 100 | return MIN_MEMORY_BLOCK_SIZE; |
| 101 | } |
| 102 | |
| 103 | static unsigned long get_memory_block_size(void) |
| 104 | { |
| 105 | unsigned long block_sz; |
| 106 | |
| 107 | block_sz = memory_block_size_bytes(); |
| 108 | |
| 109 | /* Validate blk_sz is a power of 2 and not less than section size */ |
| 110 | if ((block_sz & (block_sz - 1)) || (block_sz < MIN_MEMORY_BLOCK_SIZE)) { |
| 111 | WARN_ON(1); |
| 112 | block_sz = MIN_MEMORY_BLOCK_SIZE; |
| 113 | } |
| 114 | |
| 115 | return block_sz; |
| 116 | } |
| 117 | |
| 118 | /* |
| 119 | * use this as the physical section index that this memsection |
| 120 | * uses. |
| 121 | */ |
| 122 | |
| 123 | static ssize_t show_mem_start_phys_index(struct device *dev, |
| 124 | struct device_attribute *attr, char *buf) |
| 125 | { |
| 126 | struct memory_block *mem = |
| 127 | container_of(dev, struct memory_block, dev); |
| 128 | unsigned long phys_index; |
| 129 | |
| 130 | phys_index = mem->start_section_nr / sections_per_block; |
| 131 | return sprintf(buf, "%08lx\n", phys_index); |
| 132 | } |
| 133 | |
| 134 | static ssize_t show_mem_end_phys_index(struct device *dev, |
| 135 | struct device_attribute *attr, char *buf) |
| 136 | { |
| 137 | struct memory_block *mem = |
| 138 | container_of(dev, struct memory_block, dev); |
| 139 | unsigned long phys_index; |
| 140 | |
| 141 | phys_index = mem->end_section_nr / sections_per_block; |
| 142 | return sprintf(buf, "%08lx\n", phys_index); |
| 143 | } |
| 144 | |
| 145 | /* |
| 146 | * Show whether the section of memory is likely to be hot-removable |
| 147 | */ |
| 148 | static ssize_t show_mem_removable(struct device *dev, |
| 149 | struct device_attribute *attr, char *buf) |
| 150 | { |
| 151 | unsigned long i, pfn; |
| 152 | int ret = 1; |
| 153 | struct memory_block *mem = |
| 154 | container_of(dev, struct memory_block, dev); |
| 155 | |
| 156 | for (i = 0; i < sections_per_block; i++) { |
| 157 | pfn = section_nr_to_pfn(mem->start_section_nr + i); |
| 158 | ret &= is_mem_section_removable(pfn, PAGES_PER_SECTION); |
| 159 | } |
| 160 | |
| 161 | return sprintf(buf, "%d\n", ret); |
| 162 | } |
| 163 | |
| 164 | /* |
| 165 | * online, offline, going offline, etc. |
| 166 | */ |
| 167 | static ssize_t show_mem_state(struct device *dev, |
| 168 | struct device_attribute *attr, char *buf) |
| 169 | { |
| 170 | struct memory_block *mem = |
| 171 | container_of(dev, struct memory_block, dev); |
| 172 | ssize_t len = 0; |
| 173 | |
| 174 | /* |
| 175 | * We can probably put these states in a nice little array |
| 176 | * so that they're not open-coded |
| 177 | */ |
| 178 | switch (mem->state) { |
| 179 | case MEM_ONLINE: |
| 180 | len = sprintf(buf, "online\n"); |
| 181 | break; |
| 182 | case MEM_OFFLINE: |
| 183 | len = sprintf(buf, "offline\n"); |
| 184 | break; |
| 185 | case MEM_GOING_OFFLINE: |
| 186 | len = sprintf(buf, "going-offline\n"); |
| 187 | break; |
| 188 | default: |
| 189 | len = sprintf(buf, "ERROR-UNKNOWN-%ld\n", |
| 190 | mem->state); |
| 191 | WARN_ON(1); |
| 192 | break; |
| 193 | } |
| 194 | |
| 195 | return len; |
| 196 | } |
| 197 | |
| 198 | int memory_notify(unsigned long val, void *v) |
| 199 | { |
| 200 | return blocking_notifier_call_chain(&memory_chain, val, v); |
| 201 | } |
| 202 | |
| 203 | int memory_isolate_notify(unsigned long val, void *v) |
| 204 | { |
| 205 | return atomic_notifier_call_chain(&memory_isolate_chain, val, v); |
| 206 | } |
| 207 | |
| 208 | /* |
| 209 | * The probe routines leave the pages reserved, just as the bootmem code does. |
| 210 | * Make sure they're still that way. |
| 211 | */ |
| 212 | static bool pages_correctly_reserved(unsigned long start_pfn, |
| 213 | unsigned long nr_pages) |
| 214 | { |
| 215 | int i, j; |
| 216 | struct page *page; |
| 217 | unsigned long pfn = start_pfn; |
| 218 | |
| 219 | /* |
| 220 | * memmap between sections is not contiguous except with |
| 221 | * SPARSEMEM_VMEMMAP. We lookup the page once per section |
| 222 | * and assume memmap is contiguous within each section |
| 223 | */ |
| 224 | for (i = 0; i < sections_per_block; i++, pfn += PAGES_PER_SECTION) { |
| 225 | if (WARN_ON_ONCE(!pfn_valid(pfn))) |
| 226 | return false; |
| 227 | page = pfn_to_page(pfn); |
| 228 | |
| 229 | for (j = 0; j < PAGES_PER_SECTION; j++) { |
| 230 | if (PageReserved(page + j)) |
| 231 | continue; |
| 232 | |
| 233 | printk(KERN_WARNING "section number %ld page number %d " |
| 234 | "not reserved, was it already online?\n", |
| 235 | pfn_to_section_nr(pfn), j); |
| 236 | |
| 237 | return false; |
| 238 | } |
| 239 | } |
| 240 | |
| 241 | return true; |
| 242 | } |
| 243 | |
| 244 | /* |
| 245 | * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is |
| 246 | * OK to have direct references to sparsemem variables in here. |
| 247 | */ |
| 248 | static int |
| 249 | memory_block_action(unsigned long phys_index, unsigned long action) |
| 250 | { |
| 251 | unsigned long start_pfn, start_paddr; |
| 252 | unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block; |
| 253 | struct page *first_page; |
| 254 | int ret; |
| 255 | |
| 256 | first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT); |
| 257 | |
| 258 | switch (action) { |
| 259 | case MEM_ONLINE: |
| 260 | start_pfn = page_to_pfn(first_page); |
| 261 | |
| 262 | if (!pages_correctly_reserved(start_pfn, nr_pages)) |
| 263 | return -EBUSY; |
| 264 | |
| 265 | ret = online_pages(start_pfn, nr_pages); |
| 266 | break; |
| 267 | case MEM_OFFLINE: |
| 268 | start_paddr = page_to_pfn(first_page) << PAGE_SHIFT; |
| 269 | ret = remove_memory(start_paddr, |
| 270 | nr_pages << PAGE_SHIFT); |
| 271 | break; |
| 272 | default: |
| 273 | WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: " |
| 274 | "%ld\n", __func__, phys_index, action, action); |
| 275 | ret = -EINVAL; |
| 276 | } |
| 277 | |
| 278 | return ret; |
| 279 | } |
| 280 | |
| 281 | static int memory_block_change_state(struct memory_block *mem, |
| 282 | unsigned long to_state, unsigned long from_state_req) |
| 283 | { |
| 284 | int ret = 0; |
| 285 | |
| 286 | mutex_lock(&mem->state_mutex); |
| 287 | |
| 288 | if (mem->state != from_state_req) { |
| 289 | ret = -EINVAL; |
| 290 | goto out; |
| 291 | } |
| 292 | |
| 293 | if (to_state == MEM_OFFLINE) |
| 294 | mem->state = MEM_GOING_OFFLINE; |
| 295 | |
| 296 | ret = memory_block_action(mem->start_section_nr, to_state); |
| 297 | |
| 298 | if (ret) { |
| 299 | mem->state = from_state_req; |
| 300 | goto out; |
| 301 | } |
| 302 | |
| 303 | mem->state = to_state; |
| 304 | switch (mem->state) { |
| 305 | case MEM_OFFLINE: |
| 306 | kobject_uevent(&mem->dev.kobj, KOBJ_OFFLINE); |
| 307 | break; |
| 308 | case MEM_ONLINE: |
| 309 | kobject_uevent(&mem->dev.kobj, KOBJ_ONLINE); |
| 310 | break; |
| 311 | default: |
| 312 | break; |
| 313 | } |
| 314 | out: |
| 315 | mutex_unlock(&mem->state_mutex); |
| 316 | return ret; |
| 317 | } |
| 318 | |
| 319 | static ssize_t |
| 320 | store_mem_state(struct device *dev, |
| 321 | struct device_attribute *attr, const char *buf, size_t count) |
| 322 | { |
| 323 | struct memory_block *mem; |
| 324 | int ret = -EINVAL; |
| 325 | |
| 326 | mem = container_of(dev, struct memory_block, dev); |
| 327 | |
| 328 | if (!strncmp(buf, "online", min((int)count, 6))) |
| 329 | ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE); |
| 330 | else if(!strncmp(buf, "offline", min((int)count, 7))) |
| 331 | ret = memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE); |
| 332 | |
| 333 | if (ret) |
| 334 | return ret; |
| 335 | return count; |
| 336 | } |
| 337 | |
| 338 | /* |
| 339 | * phys_device is a bad name for this. What I really want |
| 340 | * is a way to differentiate between memory ranges that |
| 341 | * are part of physical devices that constitute |
| 342 | * a complete removable unit or fru. |
| 343 | * i.e. do these ranges belong to the same physical device, |
| 344 | * s.t. if I offline all of these sections I can then |
| 345 | * remove the physical device? |
| 346 | */ |
| 347 | static ssize_t show_phys_device(struct device *dev, |
| 348 | struct device_attribute *attr, char *buf) |
| 349 | { |
| 350 | struct memory_block *mem = |
| 351 | container_of(dev, struct memory_block, dev); |
| 352 | return sprintf(buf, "%d\n", mem->phys_device); |
| 353 | } |
| 354 | |
| 355 | static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL); |
| 356 | static DEVICE_ATTR(end_phys_index, 0444, show_mem_end_phys_index, NULL); |
| 357 | static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state); |
| 358 | static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL); |
| 359 | static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL); |
| 360 | |
| 361 | #define mem_create_simple_file(mem, attr_name) \ |
| 362 | device_create_file(&mem->dev, &dev_attr_##attr_name) |
| 363 | #define mem_remove_simple_file(mem, attr_name) \ |
| 364 | device_remove_file(&mem->dev, &dev_attr_##attr_name) |
| 365 | |
| 366 | /* |
| 367 | * Block size attribute stuff |
| 368 | */ |
| 369 | static ssize_t |
| 370 | print_block_size(struct device *dev, struct device_attribute *attr, |
| 371 | char *buf) |
| 372 | { |
| 373 | return sprintf(buf, "%lx\n", get_memory_block_size()); |
| 374 | } |
| 375 | |
| 376 | static DEVICE_ATTR(block_size_bytes, 0444, print_block_size, NULL); |
| 377 | |
| 378 | static int block_size_init(void) |
| 379 | { |
| 380 | return device_create_file(memory_subsys.dev_root, |
| 381 | &dev_attr_block_size_bytes); |
| 382 | } |
| 383 | |
| 384 | /* |
| 385 | * Some architectures will have custom drivers to do this, and |
| 386 | * will not need to do it from userspace. The fake hot-add code |
| 387 | * as well as ppc64 will do all of their discovery in userspace |
| 388 | * and will require this interface. |
| 389 | */ |
| 390 | #ifdef CONFIG_ARCH_MEMORY_PROBE |
| 391 | static ssize_t |
| 392 | memory_probe_store(struct device *dev, struct device_attribute *attr, |
| 393 | const char *buf, size_t count) |
| 394 | { |
| 395 | u64 phys_addr; |
| 396 | int nid; |
| 397 | int i, ret; |
| 398 | unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block; |
| 399 | |
| 400 | phys_addr = simple_strtoull(buf, NULL, 0); |
| 401 | |
| 402 | if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1)) |
| 403 | return -EINVAL; |
| 404 | |
| 405 | for (i = 0; i < sections_per_block; i++) { |
| 406 | nid = memory_add_physaddr_to_nid(phys_addr); |
| 407 | ret = add_memory(nid, phys_addr, |
| 408 | PAGES_PER_SECTION << PAGE_SHIFT); |
| 409 | if (ret) |
| 410 | goto out; |
| 411 | |
| 412 | phys_addr += MIN_MEMORY_BLOCK_SIZE; |
| 413 | } |
| 414 | |
| 415 | ret = count; |
| 416 | out: |
| 417 | return ret; |
| 418 | } |
| 419 | static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store); |
| 420 | |
| 421 | static int memory_probe_init(void) |
| 422 | { |
| 423 | return device_create_file(memory_subsys.dev_root, &dev_attr_probe); |
| 424 | } |
| 425 | #else |
| 426 | static inline int memory_probe_init(void) |
| 427 | { |
| 428 | return 0; |
| 429 | } |
| 430 | #endif |
| 431 | |
| 432 | #ifdef CONFIG_MEMORY_FAILURE |
| 433 | /* |
| 434 | * Support for offlining pages of memory |
| 435 | */ |
| 436 | |
| 437 | /* Soft offline a page */ |
| 438 | static ssize_t |
| 439 | store_soft_offline_page(struct device *dev, |
| 440 | struct device_attribute *attr, |
| 441 | const char *buf, size_t count) |
| 442 | { |
| 443 | int ret; |
| 444 | u64 pfn; |
| 445 | if (!capable(CAP_SYS_ADMIN)) |
| 446 | return -EPERM; |
| 447 | if (strict_strtoull(buf, 0, &pfn) < 0) |
| 448 | return -EINVAL; |
| 449 | pfn >>= PAGE_SHIFT; |
| 450 | if (!pfn_valid(pfn)) |
| 451 | return -ENXIO; |
| 452 | ret = soft_offline_page(pfn_to_page(pfn), 0); |
| 453 | return ret == 0 ? count : ret; |
| 454 | } |
| 455 | |
| 456 | /* Forcibly offline a page, including killing processes. */ |
| 457 | static ssize_t |
| 458 | store_hard_offline_page(struct device *dev, |
| 459 | struct device_attribute *attr, |
| 460 | const char *buf, size_t count) |
| 461 | { |
| 462 | int ret; |
| 463 | u64 pfn; |
| 464 | if (!capable(CAP_SYS_ADMIN)) |
| 465 | return -EPERM; |
| 466 | if (strict_strtoull(buf, 0, &pfn) < 0) |
| 467 | return -EINVAL; |
| 468 | pfn >>= PAGE_SHIFT; |
| 469 | ret = memory_failure(pfn, 0, 0); |
| 470 | return ret ? ret : count; |
| 471 | } |
| 472 | |
| 473 | static DEVICE_ATTR(soft_offline_page, 0644, NULL, store_soft_offline_page); |
| 474 | static DEVICE_ATTR(hard_offline_page, 0644, NULL, store_hard_offline_page); |
| 475 | |
| 476 | static __init int memory_fail_init(void) |
| 477 | { |
| 478 | int err; |
| 479 | |
| 480 | err = device_create_file(memory_subsys.dev_root, |
| 481 | &dev_attr_soft_offline_page); |
| 482 | if (!err) |
| 483 | err = device_create_file(memory_subsys.dev_root, |
| 484 | &dev_attr_hard_offline_page); |
| 485 | return err; |
| 486 | } |
| 487 | #else |
| 488 | static inline int memory_fail_init(void) |
| 489 | { |
| 490 | return 0; |
| 491 | } |
| 492 | #endif |
| 493 | |
| 494 | /* |
| 495 | * Note that phys_device is optional. It is here to allow for |
| 496 | * differentiation between which *physical* devices each |
| 497 | * section belongs to... |
| 498 | */ |
| 499 | int __weak arch_get_memory_phys_device(unsigned long start_pfn) |
| 500 | { |
| 501 | return 0; |
| 502 | } |
| 503 | |
| 504 | /* |
| 505 | * A reference for the returned object is held and the reference for the |
| 506 | * hinted object is released. |
| 507 | */ |
| 508 | struct memory_block *find_memory_block_hinted(struct mem_section *section, |
| 509 | struct memory_block *hint) |
| 510 | { |
| 511 | int block_id = base_memory_block_id(__section_nr(section)); |
| 512 | struct device *hintdev = hint ? &hint->dev : NULL; |
| 513 | struct device *dev; |
| 514 | |
| 515 | dev = subsys_find_device_by_id(&memory_subsys, block_id, hintdev); |
| 516 | if (hint) |
| 517 | put_device(&hint->dev); |
| 518 | if (!dev) |
| 519 | return NULL; |
| 520 | return container_of(dev, struct memory_block, dev); |
| 521 | } |
| 522 | |
| 523 | /* |
| 524 | * For now, we have a linear search to go find the appropriate |
| 525 | * memory_block corresponding to a particular phys_index. If |
| 526 | * this gets to be a real problem, we can always use a radix |
| 527 | * tree or something here. |
| 528 | * |
| 529 | * This could be made generic for all device subsystems. |
| 530 | */ |
| 531 | struct memory_block *find_memory_block(struct mem_section *section) |
| 532 | { |
| 533 | return find_memory_block_hinted(section, NULL); |
| 534 | } |
| 535 | |
| 536 | static int init_memory_block(struct memory_block **memory, |
| 537 | struct mem_section *section, unsigned long state) |
| 538 | { |
| 539 | struct memory_block *mem; |
| 540 | unsigned long start_pfn; |
| 541 | int scn_nr; |
| 542 | int ret = 0; |
| 543 | |
| 544 | mem = kzalloc(sizeof(*mem), GFP_KERNEL); |
| 545 | if (!mem) |
| 546 | return -ENOMEM; |
| 547 | |
| 548 | scn_nr = __section_nr(section); |
| 549 | mem->start_section_nr = |
| 550 | base_memory_block_id(scn_nr) * sections_per_block; |
| 551 | mem->end_section_nr = mem->start_section_nr + sections_per_block - 1; |
| 552 | mem->state = state; |
| 553 | mem->section_count++; |
| 554 | mutex_init(&mem->state_mutex); |
| 555 | start_pfn = section_nr_to_pfn(mem->start_section_nr); |
| 556 | mem->phys_device = arch_get_memory_phys_device(start_pfn); |
| 557 | |
| 558 | ret = register_memory(mem); |
| 559 | if (!ret) |
| 560 | ret = mem_create_simple_file(mem, phys_index); |
| 561 | if (!ret) |
| 562 | ret = mem_create_simple_file(mem, end_phys_index); |
| 563 | if (!ret) |
| 564 | ret = mem_create_simple_file(mem, state); |
| 565 | if (!ret) |
| 566 | ret = mem_create_simple_file(mem, phys_device); |
| 567 | if (!ret) |
| 568 | ret = mem_create_simple_file(mem, removable); |
| 569 | |
| 570 | *memory = mem; |
| 571 | return ret; |
| 572 | } |
| 573 | |
| 574 | static int add_memory_section(int nid, struct mem_section *section, |
| 575 | struct memory_block **mem_p, |
| 576 | unsigned long state, enum mem_add_context context) |
| 577 | { |
| 578 | struct memory_block *mem = NULL; |
| 579 | int scn_nr = __section_nr(section); |
| 580 | int ret = 0; |
| 581 | |
| 582 | mutex_lock(&mem_sysfs_mutex); |
| 583 | |
| 584 | if (context == BOOT) { |
| 585 | /* same memory block ? */ |
| 586 | if (mem_p && *mem_p) |
| 587 | if (scn_nr >= (*mem_p)->start_section_nr && |
| 588 | scn_nr <= (*mem_p)->end_section_nr) { |
| 589 | mem = *mem_p; |
| 590 | kobject_get(&mem->dev.kobj); |
| 591 | } |
| 592 | } else |
| 593 | mem = find_memory_block(section); |
| 594 | |
| 595 | if (mem) { |
| 596 | mem->section_count++; |
| 597 | kobject_put(&mem->dev.kobj); |
| 598 | } else { |
| 599 | ret = init_memory_block(&mem, section, state); |
| 600 | /* store memory_block pointer for next loop */ |
| 601 | if (!ret && context == BOOT) |
| 602 | if (mem_p) |
| 603 | *mem_p = mem; |
| 604 | } |
| 605 | |
| 606 | if (!ret) { |
| 607 | if (context == HOTPLUG && |
| 608 | mem->section_count == sections_per_block) |
| 609 | ret = register_mem_sect_under_node(mem, nid); |
| 610 | } |
| 611 | |
| 612 | mutex_unlock(&mem_sysfs_mutex); |
| 613 | return ret; |
| 614 | } |
| 615 | |
| 616 | int remove_memory_block(unsigned long node_id, struct mem_section *section, |
| 617 | int phys_device) |
| 618 | { |
| 619 | struct memory_block *mem; |
| 620 | |
| 621 | mutex_lock(&mem_sysfs_mutex); |
| 622 | mem = find_memory_block(section); |
| 623 | unregister_mem_sect_under_nodes(mem, __section_nr(section)); |
| 624 | |
| 625 | mem->section_count--; |
| 626 | if (mem->section_count == 0) { |
| 627 | mem_remove_simple_file(mem, phys_index); |
| 628 | mem_remove_simple_file(mem, end_phys_index); |
| 629 | mem_remove_simple_file(mem, state); |
| 630 | mem_remove_simple_file(mem, phys_device); |
| 631 | mem_remove_simple_file(mem, removable); |
| 632 | unregister_memory(mem); |
| 633 | kfree(mem); |
| 634 | } else |
| 635 | kobject_put(&mem->dev.kobj); |
| 636 | |
| 637 | mutex_unlock(&mem_sysfs_mutex); |
| 638 | return 0; |
| 639 | } |
| 640 | |
| 641 | /* |
| 642 | * need an interface for the VM to add new memory regions, |
| 643 | * but without onlining it. |
| 644 | */ |
| 645 | int register_new_memory(int nid, struct mem_section *section) |
| 646 | { |
| 647 | return add_memory_section(nid, section, NULL, MEM_OFFLINE, HOTPLUG); |
| 648 | } |
| 649 | |
| 650 | int unregister_memory_section(struct mem_section *section) |
| 651 | { |
| 652 | if (!present_section(section)) |
| 653 | return -EINVAL; |
| 654 | |
| 655 | return remove_memory_block(0, section, 0); |
| 656 | } |
| 657 | |
| 658 | /* |
| 659 | * Initialize the sysfs support for memory devices... |
| 660 | */ |
| 661 | int __init memory_dev_init(void) |
| 662 | { |
| 663 | unsigned int i; |
| 664 | int ret; |
| 665 | int err; |
| 666 | unsigned long block_sz; |
| 667 | struct memory_block *mem = NULL; |
| 668 | |
| 669 | ret = subsys_system_register(&memory_subsys, NULL); |
| 670 | if (ret) |
| 671 | goto out; |
| 672 | |
| 673 | block_sz = get_memory_block_size(); |
| 674 | sections_per_block = block_sz / MIN_MEMORY_BLOCK_SIZE; |
| 675 | |
| 676 | /* |
| 677 | * Create entries for memory sections that were found |
| 678 | * during boot and have been initialized |
| 679 | */ |
| 680 | for (i = 0; i < NR_MEM_SECTIONS; i++) { |
| 681 | if (!present_section_nr(i)) |
| 682 | continue; |
| 683 | /* don't need to reuse memory_block if only one per block */ |
| 684 | err = add_memory_section(0, __nr_to_section(i), |
| 685 | (sections_per_block == 1) ? NULL : &mem, |
| 686 | MEM_ONLINE, |
| 687 | BOOT); |
| 688 | if (!ret) |
| 689 | ret = err; |
| 690 | } |
| 691 | |
| 692 | err = memory_probe_init(); |
| 693 | if (!ret) |
| 694 | ret = err; |
| 695 | err = memory_fail_init(); |
| 696 | if (!ret) |
| 697 | ret = err; |
| 698 | err = block_size_init(); |
| 699 | if (!ret) |
| 700 | ret = err; |
| 701 | out: |
| 702 | if (ret) |
| 703 | printk(KERN_ERR "%s() failed: %d\n", __func__, ret); |
| 704 | return ret; |
| 705 | } |