1 /* 2 * linux/mm/vmalloc.c 3 * 4 * Copyright (C) 1993 Linus Torvalds 5 * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 6 * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000 7 * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002 8 * Numa awareness, Christoph Lameter, SGI, June 2005 9 */ 10 11 #include <linux/vmalloc.h> 12 #include <linux/mm.h> 13 #include <linux/module.h> 14 #include <linux/highmem.h> 15 #include <linux/sched.h> 16 #include <linux/slab.h> 17 #include <linux/spinlock.h> 18 #include <linux/interrupt.h> 19 #include <linux/proc_fs.h> 20 #include <linux/seq_file.h> 21 #include <linux/debugobjects.h> 22 #include <linux/kallsyms.h> 23 #include <linux/list.h> 24 #include <linux/rbtree.h> 25 #include <linux/radix-tree.h> 26 #include <linux/rcupdate.h> 27 #include <linux/pfn.h> 28 #include <linux/kmemleak.h> 29 #include <asm/atomic.h> 30 #include <asm/uaccess.h> 31 #include <asm/tlbflush.h> 32 #include <asm/shmparam.h> 33 34 35 /*** Page table manipulation functions ***/ 36 37 static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end) 38 { 39 pte_t *pte; 40 41 pte = pte_offset_kernel(pmd, addr); 42 do { 43 pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); 44 WARN_ON(!pte_none(ptent) && !pte_present(ptent)); 45 } while (pte++, addr += PAGE_SIZE, addr != end); 46 } 47 48 static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end) 49 { 50 pmd_t *pmd; 51 unsigned long next; 52 53 pmd = pmd_offset(pud, addr); 54 do { 55 next = pmd_addr_end(addr, end); 56 if (pmd_none_or_clear_bad(pmd)) 57 continue; 58 vunmap_pte_range(pmd, addr, next); 59 } while (pmd++, addr = next, addr != end); 60 } 61 62 static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end) 63 { 64 pud_t *pud; 65 unsigned long next; 66 67 pud = pud_offset(pgd, addr); 68 do { 69 next = pud_addr_end(addr, end); 70 if (pud_none_or_clear_bad(pud)) 71 continue; 72 vunmap_pmd_range(pud, addr, next); 73 } while (pud++, addr = next, addr != end); 74 } 75 76 static void vunmap_page_range(unsigned long addr, unsigned long end) 77 { 78 pgd_t *pgd; 79 unsigned long next; 80 81 BUG_ON(addr >= end); 82 pgd = pgd_offset_k(addr); 83 do { 84 next = pgd_addr_end(addr, end); 85 if (pgd_none_or_clear_bad(pgd)) 86 continue; 87 vunmap_pud_range(pgd, addr, next); 88 } while (pgd++, addr = next, addr != end); 89 } 90 91 static int vmap_pte_range(pmd_t *pmd, unsigned long addr, 92 unsigned long end, pgprot_t prot, struct page **pages, int *nr) 93 { 94 pte_t *pte; 95 96 /* 97 * nr is a running index into the array which helps higher level 98 * callers keep track of where we're up to. 99 */ 100 101 pte = pte_alloc_kernel(pmd, addr); 102 if (!pte) 103 return -ENOMEM; 104 do { 105 struct page *page = pages[*nr]; 106 107 if (WARN_ON(!pte_none(*pte))) 108 return -EBUSY; 109 if (WARN_ON(!page)) 110 return -ENOMEM; 111 set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); 112 (*nr)++; 113 } while (pte++, addr += PAGE_SIZE, addr != end); 114 return 0; 115 } 116 117 static int vmap_pmd_range(pud_t *pud, unsigned long addr, 118 unsigned long end, pgprot_t prot, struct page **pages, int *nr) 119 { 120 pmd_t *pmd; 121 unsigned long next; 122 123 pmd = pmd_alloc(&init_mm, pud, addr); 124 if (!pmd) 125 return -ENOMEM; 126 do { 127 next = pmd_addr_end(addr, end); 128 if (vmap_pte_range(pmd, addr, next, prot, pages, nr)) 129 return -ENOMEM; 130 } while (pmd++, addr = next, addr != end); 131 return 0; 132 } 133 134 static int vmap_pud_range(pgd_t *pgd, unsigned long addr, 135 unsigned long end, pgprot_t prot, struct page **pages, int *nr) 136 { 137 pud_t *pud; 138 unsigned long next; 139 140 pud = pud_alloc(&init_mm, pgd, addr); 141 if (!pud) 142 return -ENOMEM; 143 do { 144 next = pud_addr_end(addr, end); 145 if (vmap_pmd_range(pud, addr, next, prot, pages, nr)) 146 return -ENOMEM; 147 } while (pud++, addr = next, addr != end); 148 return 0; 149 } 150 151 /* 152 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and 153 * will have pfns corresponding to the "pages" array. 154 * 155 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N] 156 */ 157 static int vmap_page_range_noflush(unsigned long start, unsigned long end, 158 pgprot_t prot, struct page **pages) 159 { 160 pgd_t *pgd; 161 unsigned long next; 162 unsigned long addr = start; 163 int err = 0; 164 int nr = 0; 165 166 BUG_ON(addr >= end); 167 pgd = pgd_offset_k(addr); 168 do { 169 next = pgd_addr_end(addr, end); 170 err = vmap_pud_range(pgd, addr, next, prot, pages, &nr); 171 if (err) 172 return err; 173 } while (pgd++, addr = next, addr != end); 174 175 return nr; 176 } 177 178 static int vmap_page_range(unsigned long start, unsigned long end, 179 pgprot_t prot, struct page **pages) 180 { 181 int ret; 182 183 ret = vmap_page_range_noflush(start, end, prot, pages); 184 flush_cache_vmap(start, end); 185 return ret; 186 } 187 188 int is_vmalloc_or_module_addr(const void *x) 189 { 190 /* 191 * ARM, x86-64 and sparc64 put modules in a special place, 192 * and fall back on vmalloc() if that fails. Others 193 * just put it in the vmalloc space. 194 */ 195 #if defined(CONFIG_MODULES) && defined(MODULES_VADDR) 196 unsigned long addr = (unsigned long)x; 197 if (addr >= MODULES_VADDR && addr < MODULES_END) 198 return 1; 199 #endif 200 return is_vmalloc_addr(x); 201 } 202 203 /* 204 * Walk a vmap address to the struct page it maps. 205 */ 206 struct page *vmalloc_to_page(const void *vmalloc_addr) 207 { 208 unsigned long addr = (unsigned long) vmalloc_addr; 209 struct page *page = NULL; 210 pgd_t *pgd = pgd_offset_k(addr); 211 212 /* 213 * XXX we might need to change this if we add VIRTUAL_BUG_ON for 214 * architectures that do not vmalloc module space 215 */ 216 VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr)); 217 218 if (!pgd_none(*pgd)) { 219 pud_t *pud = pud_offset(pgd, addr); 220 if (!pud_none(*pud)) { 221 pmd_t *pmd = pmd_offset(pud, addr); 222 if (!pmd_none(*pmd)) { 223 pte_t *ptep, pte; 224 225 ptep = pte_offset_map(pmd, addr); 226 pte = *ptep; 227 if (pte_present(pte)) 228 page = pte_page(pte); 229 pte_unmap(ptep); 230 } 231 } 232 } 233 return page; 234 } 235 EXPORT_SYMBOL(vmalloc_to_page); 236 237 /* 238 * Map a vmalloc()-space virtual address to the physical page frame number. 239 */ 240 unsigned long vmalloc_to_pfn(const void *vmalloc_addr) 241 { 242 return page_to_pfn(vmalloc_to_page(vmalloc_addr)); 243 } 244 EXPORT_SYMBOL(vmalloc_to_pfn); 245 246 247 /*** Global kva allocator ***/ 248 249 #define VM_LAZY_FREE 0x01 250 #define VM_LAZY_FREEING 0x02 251 #define VM_VM_AREA 0x04 252 253 struct vmap_area { 254 unsigned long va_start; 255 unsigned long va_end; 256 unsigned long flags; 257 struct rb_node rb_node; /* address sorted rbtree */ 258 struct list_head list; /* address sorted list */ 259 struct list_head purge_list; /* "lazy purge" list */ 260 void *private; 261 struct rcu_head rcu_head; 262 }; 263 264 static DEFINE_SPINLOCK(vmap_area_lock); 265 static struct rb_root vmap_area_root = RB_ROOT; 266 static LIST_HEAD(vmap_area_list); 267 static unsigned long vmap_area_pcpu_hole; 268 269 static struct vmap_area *__find_vmap_area(unsigned long addr) 270 { 271 struct rb_node *n = vmap_area_root.rb_node; 272 273 while (n) { 274 struct vmap_area *va; 275 276 va = rb_entry(n, struct vmap_area, rb_node); 277 if (addr < va->va_start) 278 n = n->rb_left; 279 else if (addr > va->va_start) 280 n = n->rb_right; 281 else 282 return va; 283 } 284 285 return NULL; 286 } 287 288 static void __insert_vmap_area(struct vmap_area *va) 289 { 290 struct rb_node **p = &vmap_area_root.rb_node; 291 struct rb_node *parent = NULL; 292 struct rb_node *tmp; 293 294 while (*p) { 295 struct vmap_area *tmp; 296 297 parent = *p; 298 tmp = rb_entry(parent, struct vmap_area, rb_node); 299 if (va->va_start < tmp->va_end) 300 p = &(*p)->rb_left; 301 else if (va->va_end > tmp->va_start) 302 p = &(*p)->rb_right; 303 else 304 BUG(); 305 } 306 307 rb_link_node(&va->rb_node, parent, p); 308 rb_insert_color(&va->rb_node, &vmap_area_root); 309 310 /* address-sort this list so it is usable like the vmlist */ 311 tmp = rb_prev(&va->rb_node); 312 if (tmp) { 313 struct vmap_area *prev; 314 prev = rb_entry(tmp, struct vmap_area, rb_node); 315 list_add_rcu(&va->list, &prev->list); 316 } else 317 list_add_rcu(&va->list, &vmap_area_list); 318 } 319 320 static void purge_vmap_area_lazy(void); 321 322 /* 323 * Allocate a region of KVA of the specified size and alignment, within the 324 * vstart and vend. 325 */ 326 static struct vmap_area *alloc_vmap_area(unsigned long size, 327 unsigned long align, 328 unsigned long vstart, unsigned long vend, 329 int node, gfp_t gfp_mask) 330 { 331 struct vmap_area *va; 332 struct rb_node *n; 333 unsigned long addr; 334 int purged = 0; 335 336 BUG_ON(!size); 337 BUG_ON(size & ~PAGE_MASK); 338 339 va = kmalloc_node(sizeof(struct vmap_area), 340 gfp_mask & GFP_RECLAIM_MASK, node); 341 if (unlikely(!va)) 342 return ERR_PTR(-ENOMEM); 343 344 retry: 345 addr = ALIGN(vstart, align); 346 347 spin_lock(&vmap_area_lock); 348 if (addr + size - 1 < addr) 349 goto overflow; 350 351 /* XXX: could have a last_hole cache */ 352 n = vmap_area_root.rb_node; 353 if (n) { 354 struct vmap_area *first = NULL; 355 356 do { 357 struct vmap_area *tmp; 358 tmp = rb_entry(n, struct vmap_area, rb_node); 359 if (tmp->va_end >= addr) { 360 if (!first && tmp->va_start < addr + size) 361 first = tmp; 362 n = n->rb_left; 363 } else { 364 first = tmp; 365 n = n->rb_right; 366 } 367 } while (n); 368 369 if (!first) 370 goto found; 371 372 if (first->va_end < addr) { 373 n = rb_next(&first->rb_node); 374 if (n) 375 first = rb_entry(n, struct vmap_area, rb_node); 376 else 377 goto found; 378 } 379 380 while (addr + size > first->va_start && addr + size <= vend) { 381 addr = ALIGN(first->va_end + PAGE_SIZE, align); 382 if (addr + size - 1 < addr) 383 goto overflow; 384 385 n = rb_next(&first->rb_node); 386 if (n) 387 first = rb_entry(n, struct vmap_area, rb_node); 388 else 389 goto found; 390 } 391 } 392 found: 393 if (addr + size > vend) { 394 overflow: 395 spin_unlock(&vmap_area_lock); 396 if (!purged) { 397 purge_vmap_area_lazy(); 398 purged = 1; 399 goto retry; 400 } 401 if (printk_ratelimit()) 402 printk(KERN_WARNING 403 "vmap allocation for size %lu failed: " 404 "use vmalloc=<size> to increase size.\n", size); 405 kfree(va); 406 return ERR_PTR(-EBUSY); 407 } 408 409 BUG_ON(addr & (align-1)); 410 411 va->va_start = addr; 412 va->va_end = addr + size; 413 va->flags = 0; 414 __insert_vmap_area(va); 415 spin_unlock(&vmap_area_lock); 416 417 return va; 418 } 419 420 static void rcu_free_va(struct rcu_head *head) 421 { 422 struct vmap_area *va = container_of(head, struct vmap_area, rcu_head); 423 424 kfree(va); 425 } 426 427 static void __free_vmap_area(struct vmap_area *va) 428 { 429 BUG_ON(RB_EMPTY_NODE(&va->rb_node)); 430 rb_erase(&va->rb_node, &vmap_area_root); 431 RB_CLEAR_NODE(&va->rb_node); 432 list_del_rcu(&va->list); 433 434 /* 435 * Track the highest possible candidate for pcpu area 436 * allocation. Areas outside of vmalloc area can be returned 437 * here too, consider only end addresses which fall inside 438 * vmalloc area proper. 439 */ 440 if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END) 441 vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end); 442 443 call_rcu(&va->rcu_head, rcu_free_va); 444 } 445 446 /* 447 * Free a region of KVA allocated by alloc_vmap_area 448 */ 449 static void free_vmap_area(struct vmap_area *va) 450 { 451 spin_lock(&vmap_area_lock); 452 __free_vmap_area(va); 453 spin_unlock(&vmap_area_lock); 454 } 455 456 /* 457 * Clear the pagetable entries of a given vmap_area 458 */ 459 static void unmap_vmap_area(struct vmap_area *va) 460 { 461 vunmap_page_range(va->va_start, va->va_end); 462 } 463 464 static void vmap_debug_free_range(unsigned long start, unsigned long end) 465 { 466 /* 467 * Unmap page tables and force a TLB flush immediately if 468 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free 469 * bugs similarly to those in linear kernel virtual address 470 * space after a page has been freed. 471 * 472 * All the lazy freeing logic is still retained, in order to 473 * minimise intrusiveness of this debugging feature. 474 * 475 * This is going to be *slow* (linear kernel virtual address 476 * debugging doesn't do a broadcast TLB flush so it is a lot 477 * faster). 478 */ 479 #ifdef CONFIG_DEBUG_PAGEALLOC 480 vunmap_page_range(start, end); 481 flush_tlb_kernel_range(start, end); 482 #endif 483 } 484 485 /* 486 * lazy_max_pages is the maximum amount of virtual address space we gather up 487 * before attempting to purge with a TLB flush. 488 * 489 * There is a tradeoff here: a larger number will cover more kernel page tables 490 * and take slightly longer to purge, but it will linearly reduce the number of 491 * global TLB flushes that must be performed. It would seem natural to scale 492 * this number up linearly with the number of CPUs (because vmapping activity 493 * could also scale linearly with the number of CPUs), however it is likely 494 * that in practice, workloads might be constrained in other ways that mean 495 * vmap activity will not scale linearly with CPUs. Also, I want to be 496 * conservative and not introduce a big latency on huge systems, so go with 497 * a less aggressive log scale. It will still be an improvement over the old 498 * code, and it will be simple to change the scale factor if we find that it 499 * becomes a problem on bigger systems. 500 */ 501 static unsigned long lazy_max_pages(void) 502 { 503 unsigned int log; 504 505 log = fls(num_online_cpus()); 506 507 return log * (32UL * 1024 * 1024 / PAGE_SIZE); 508 } 509 510 static atomic_t vmap_lazy_nr = ATOMIC_INIT(0); 511 512 /* 513 * Purges all lazily-freed vmap areas. 514 * 515 * If sync is 0 then don't purge if there is already a purge in progress. 516 * If force_flush is 1, then flush kernel TLBs between *start and *end even 517 * if we found no lazy vmap areas to unmap (callers can use this to optimise 518 * their own TLB flushing). 519 * Returns with *start = min(*start, lowest purged address) 520 * *end = max(*end, highest purged address) 521 */ 522 static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end, 523 int sync, int force_flush) 524 { 525 static DEFINE_SPINLOCK(purge_lock); 526 LIST_HEAD(valist); 527 struct vmap_area *va; 528 struct vmap_area *n_va; 529 int nr = 0; 530 531 /* 532 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers 533 * should not expect such behaviour. This just simplifies locking for 534 * the case that isn't actually used at the moment anyway. 535 */ 536 if (!sync && !force_flush) { 537 if (!spin_trylock(&purge_lock)) 538 return; 539 } else 540 spin_lock(&purge_lock); 541 542 rcu_read_lock(); 543 list_for_each_entry_rcu(va, &vmap_area_list, list) { 544 if (va->flags & VM_LAZY_FREE) { 545 if (va->va_start < *start) 546 *start = va->va_start; 547 if (va->va_end > *end) 548 *end = va->va_end; 549 nr += (va->va_end - va->va_start) >> PAGE_SHIFT; 550 unmap_vmap_area(va); 551 list_add_tail(&va->purge_list, &valist); 552 va->flags |= VM_LAZY_FREEING; 553 va->flags &= ~VM_LAZY_FREE; 554 } 555 } 556 rcu_read_unlock(); 557 558 if (nr) { 559 BUG_ON(nr > atomic_read(&vmap_lazy_nr)); 560 atomic_sub(nr, &vmap_lazy_nr); 561 } 562 563 if (nr || force_flush) 564 flush_tlb_kernel_range(*start, *end); 565 566 if (nr) { 567 spin_lock(&vmap_area_lock); 568 list_for_each_entry_safe(va, n_va, &valist, purge_list) 569 __free_vmap_area(va); 570 spin_unlock(&vmap_area_lock); 571 } 572 spin_unlock(&purge_lock); 573 } 574 575 /* 576 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody 577 * is already purging. 578 */ 579 static void try_purge_vmap_area_lazy(void) 580 { 581 unsigned long start = ULONG_MAX, end = 0; 582 583 __purge_vmap_area_lazy(&start, &end, 0, 0); 584 } 585 586 /* 587 * Kick off a purge of the outstanding lazy areas. 588 */ 589 static void purge_vmap_area_lazy(void) 590 { 591 unsigned long start = ULONG_MAX, end = 0; 592 593 __purge_vmap_area_lazy(&start, &end, 1, 0); 594 } 595 596 /* 597 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been 598 * called for the correct range previously. 599 */ 600 static void free_unmap_vmap_area_noflush(struct vmap_area *va) 601 { 602 va->flags |= VM_LAZY_FREE; 603 atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr); 604 if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages())) 605 try_purge_vmap_area_lazy(); 606 } 607 608 /* 609 * Free and unmap a vmap area 610 */ 611 static void free_unmap_vmap_area(struct vmap_area *va) 612 { 613 flush_cache_vunmap(va->va_start, va->va_end); 614 free_unmap_vmap_area_noflush(va); 615 } 616 617 static struct vmap_area *find_vmap_area(unsigned long addr) 618 { 619 struct vmap_area *va; 620 621 spin_lock(&vmap_area_lock); 622 va = __find_vmap_area(addr); 623 spin_unlock(&vmap_area_lock); 624 625 return va; 626 } 627 628 static void free_unmap_vmap_area_addr(unsigned long addr) 629 { 630 struct vmap_area *va; 631 632 va = find_vmap_area(addr); 633 BUG_ON(!va); 634 free_unmap_vmap_area(va); 635 } 636 637 638 /*** Per cpu kva allocator ***/ 639 640 /* 641 * vmap space is limited especially on 32 bit architectures. Ensure there is 642 * room for at least 16 percpu vmap blocks per CPU. 643 */ 644 /* 645 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able 646 * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess 647 * instead (we just need a rough idea) 648 */ 649 #if BITS_PER_LONG == 32 650 #define VMALLOC_SPACE (128UL*1024*1024) 651 #else 652 #define VMALLOC_SPACE (128UL*1024*1024*1024) 653 #endif 654 655 #define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE) 656 #define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */ 657 #define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */ 658 #define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2) 659 #define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */ 660 #define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */ 661 #define VMAP_BBMAP_BITS VMAP_MIN(VMAP_BBMAP_BITS_MAX, \ 662 VMAP_MAX(VMAP_BBMAP_BITS_MIN, \ 663 VMALLOC_PAGES / NR_CPUS / 16)) 664 665 #define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE) 666 667 static bool vmap_initialized __read_mostly = false; 668 669 struct vmap_block_queue { 670 spinlock_t lock; 671 struct list_head free; 672 struct list_head dirty; 673 unsigned int nr_dirty; 674 }; 675 676 struct vmap_block { 677 spinlock_t lock; 678 struct vmap_area *va; 679 struct vmap_block_queue *vbq; 680 unsigned long free, dirty; 681 DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS); 682 DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS); 683 union { 684 struct list_head free_list; 685 struct rcu_head rcu_head; 686 }; 687 }; 688 689 /* Queue of free and dirty vmap blocks, for allocation and flushing purposes */ 690 static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue); 691 692 /* 693 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block 694 * in the free path. Could get rid of this if we change the API to return a 695 * "cookie" from alloc, to be passed to free. But no big deal yet. 696 */ 697 static DEFINE_SPINLOCK(vmap_block_tree_lock); 698 static RADIX_TREE(vmap_block_tree, GFP_ATOMIC); 699 700 /* 701 * We should probably have a fallback mechanism to allocate virtual memory 702 * out of partially filled vmap blocks. However vmap block sizing should be 703 * fairly reasonable according to the vmalloc size, so it shouldn't be a 704 * big problem. 705 */ 706 707 static unsigned long addr_to_vb_idx(unsigned long addr) 708 { 709 addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1); 710 addr /= VMAP_BLOCK_SIZE; 711 return addr; 712 } 713 714 static struct vmap_block *new_vmap_block(gfp_t gfp_mask) 715 { 716 struct vmap_block_queue *vbq; 717 struct vmap_block *vb; 718 struct vmap_area *va; 719 unsigned long vb_idx; 720 int node, err; 721 722 node = numa_node_id(); 723 724 vb = kmalloc_node(sizeof(struct vmap_block), 725 gfp_mask & GFP_RECLAIM_MASK, node); 726 if (unlikely(!vb)) 727 return ERR_PTR(-ENOMEM); 728 729 va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE, 730 VMALLOC_START, VMALLOC_END, 731 node, gfp_mask); 732 if (unlikely(IS_ERR(va))) { 733 kfree(vb); 734 return ERR_PTR(PTR_ERR(va)); 735 } 736 737 err = radix_tree_preload(gfp_mask); 738 if (unlikely(err)) { 739 kfree(vb); 740 free_vmap_area(va); 741 return ERR_PTR(err); 742 } 743 744 spin_lock_init(&vb->lock); 745 vb->va = va; 746 vb->free = VMAP_BBMAP_BITS; 747 vb->dirty = 0; 748 bitmap_zero(vb->alloc_map, VMAP_BBMAP_BITS); 749 bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS); 750 INIT_LIST_HEAD(&vb->free_list); 751 752 vb_idx = addr_to_vb_idx(va->va_start); 753 spin_lock(&vmap_block_tree_lock); 754 err = radix_tree_insert(&vmap_block_tree, vb_idx, vb); 755 spin_unlock(&vmap_block_tree_lock); 756 BUG_ON(err); 757 radix_tree_preload_end(); 758 759 vbq = &get_cpu_var(vmap_block_queue); 760 vb->vbq = vbq; 761 spin_lock(&vbq->lock); 762 list_add(&vb->free_list, &vbq->free); 763 spin_unlock(&vbq->lock); 764 put_cpu_var(vmap_block_queue); 765 766 return vb; 767 } 768 769 static void rcu_free_vb(struct rcu_head *head) 770 { 771 struct vmap_block *vb = container_of(head, struct vmap_block, rcu_head); 772 773 kfree(vb); 774 } 775 776 static void free_vmap_block(struct vmap_block *vb) 777 { 778 struct vmap_block *tmp; 779 unsigned long vb_idx; 780 781 BUG_ON(!list_empty(&vb->free_list)); 782 783 vb_idx = addr_to_vb_idx(vb->va->va_start); 784 spin_lock(&vmap_block_tree_lock); 785 tmp = radix_tree_delete(&vmap_block_tree, vb_idx); 786 spin_unlock(&vmap_block_tree_lock); 787 BUG_ON(tmp != vb); 788 789 free_unmap_vmap_area_noflush(vb->va); 790 call_rcu(&vb->rcu_head, rcu_free_vb); 791 } 792 793 static void *vb_alloc(unsigned long size, gfp_t gfp_mask) 794 { 795 struct vmap_block_queue *vbq; 796 struct vmap_block *vb; 797 unsigned long addr = 0; 798 unsigned int order; 799 800 BUG_ON(size & ~PAGE_MASK); 801 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); 802 order = get_order(size); 803 804 again: 805 rcu_read_lock(); 806 vbq = &get_cpu_var(vmap_block_queue); 807 list_for_each_entry_rcu(vb, &vbq->free, free_list) { 808 int i; 809 810 spin_lock(&vb->lock); 811 i = bitmap_find_free_region(vb->alloc_map, 812 VMAP_BBMAP_BITS, order); 813 814 if (i >= 0) { 815 addr = vb->va->va_start + (i << PAGE_SHIFT); 816 BUG_ON(addr_to_vb_idx(addr) != 817 addr_to_vb_idx(vb->va->va_start)); 818 vb->free -= 1UL << order; 819 if (vb->free == 0) { 820 spin_lock(&vbq->lock); 821 list_del_init(&vb->free_list); 822 spin_unlock(&vbq->lock); 823 } 824 spin_unlock(&vb->lock); 825 break; 826 } 827 spin_unlock(&vb->lock); 828 } 829 put_cpu_var(vmap_block_queue); 830 rcu_read_unlock(); 831 832 if (!addr) { 833 vb = new_vmap_block(gfp_mask); 834 if (IS_ERR(vb)) 835 return vb; 836 goto again; 837 } 838 839 return (void *)addr; 840 } 841 842 static void vb_free(const void *addr, unsigned long size) 843 { 844 unsigned long offset; 845 unsigned long vb_idx; 846 unsigned int order; 847 struct vmap_block *vb; 848 849 BUG_ON(size & ~PAGE_MASK); 850 BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); 851 852 flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size); 853 854 order = get_order(size); 855 856 offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1); 857 858 vb_idx = addr_to_vb_idx((unsigned long)addr); 859 rcu_read_lock(); 860 vb = radix_tree_lookup(&vmap_block_tree, vb_idx); 861 rcu_read_unlock(); 862 BUG_ON(!vb); 863 864 spin_lock(&vb->lock); 865 bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order); 866 867 vb->dirty += 1UL << order; 868 if (vb->dirty == VMAP_BBMAP_BITS) { 869 BUG_ON(vb->free || !list_empty(&vb->free_list)); 870 spin_unlock(&vb->lock); 871 free_vmap_block(vb); 872 } else 873 spin_unlock(&vb->lock); 874 } 875 876 /** 877 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer 878 * 879 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily 880 * to amortize TLB flushing overheads. What this means is that any page you 881 * have now, may, in a former life, have been mapped into kernel virtual 882 * address by the vmap layer and so there might be some CPUs with TLB entries 883 * still referencing that page (additional to the regular 1:1 kernel mapping). 884 * 885 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can 886 * be sure that none of the pages we have control over will have any aliases 887 * from the vmap layer. 888 */ 889 void vm_unmap_aliases(void) 890 { 891 unsigned long start = ULONG_MAX, end = 0; 892 int cpu; 893 int flush = 0; 894 895 if (unlikely(!vmap_initialized)) 896 return; 897 898 for_each_possible_cpu(cpu) { 899 struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); 900 struct vmap_block *vb; 901 902 rcu_read_lock(); 903 list_for_each_entry_rcu(vb, &vbq->free, free_list) { 904 int i; 905 906 spin_lock(&vb->lock); 907 i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS); 908 while (i < VMAP_BBMAP_BITS) { 909 unsigned long s, e; 910 int j; 911 j = find_next_zero_bit(vb->dirty_map, 912 VMAP_BBMAP_BITS, i); 913 914 s = vb->va->va_start + (i << PAGE_SHIFT); 915 e = vb->va->va_start + (j << PAGE_SHIFT); 916 vunmap_page_range(s, e); 917 flush = 1; 918 919 if (s < start) 920 start = s; 921 if (e > end) 922 end = e; 923 924 i = j; 925 i = find_next_bit(vb->dirty_map, 926 VMAP_BBMAP_BITS, i); 927 } 928 spin_unlock(&vb->lock); 929 } 930 rcu_read_unlock(); 931 } 932 933 __purge_vmap_area_lazy(&start, &end, 1, flush); 934 } 935 EXPORT_SYMBOL_GPL(vm_unmap_aliases); 936 937 /** 938 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram 939 * @mem: the pointer returned by vm_map_ram 940 * @count: the count passed to that vm_map_ram call (cannot unmap partial) 941 */ 942 void vm_unmap_ram(const void *mem, unsigned int count) 943 { 944 unsigned long size = count << PAGE_SHIFT; 945 unsigned long addr = (unsigned long)mem; 946 947 BUG_ON(!addr); 948 BUG_ON(addr < VMALLOC_START); 949 BUG_ON(addr > VMALLOC_END); 950 BUG_ON(addr & (PAGE_SIZE-1)); 951 952 debug_check_no_locks_freed(mem, size); 953 vmap_debug_free_range(addr, addr+size); 954 955 if (likely(count <= VMAP_MAX_ALLOC)) 956 vb_free(mem, size); 957 else 958 free_unmap_vmap_area_addr(addr); 959 } 960 EXPORT_SYMBOL(vm_unmap_ram); 961 962 /** 963 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space) 964 * @pages: an array of pointers to the pages to be mapped 965 * @count: number of pages 966 * @node: prefer to allocate data structures on this node 967 * @prot: memory protection to use. PAGE_KERNEL for regular RAM 968 * 969 * Returns: a pointer to the address that has been mapped, or %NULL on failure 970 */ 971 void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot) 972 { 973 unsigned long size = count << PAGE_SHIFT; 974 unsigned long addr; 975 void *mem; 976 977 if (likely(count <= VMAP_MAX_ALLOC)) { 978 mem = vb_alloc(size, GFP_KERNEL); 979 if (IS_ERR(mem)) 980 return NULL; 981 addr = (unsigned long)mem; 982 } else { 983 struct vmap_area *va; 984 va = alloc_vmap_area(size, PAGE_SIZE, 985 VMALLOC_START, VMALLOC_END, node, GFP_KERNEL); 986 if (IS_ERR(va)) 987 return NULL; 988 989 addr = va->va_start; 990 mem = (void *)addr; 991 } 992 if (vmap_page_range(addr, addr + size, prot, pages) < 0) { 993 vm_unmap_ram(mem, count); 994 return NULL; 995 } 996 return mem; 997 } 998 EXPORT_SYMBOL(vm_map_ram); 999 1000 /** 1001 * vm_area_register_early - register vmap area early during boot 1002 * @vm: vm_struct to register 1003 * @align: requested alignment 1004 * 1005 * This function is used to register kernel vm area before 1006 * vmalloc_init() is called. @vm->size and @vm->flags should contain 1007 * proper values on entry and other fields should be zero. On return, 1008 * vm->addr contains the allocated address. 1009 * 1010 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. 1011 */ 1012 void __init vm_area_register_early(struct vm_struct *vm, size_t align) 1013 { 1014 static size_t vm_init_off __initdata; 1015 unsigned long addr; 1016 1017 addr = ALIGN(VMALLOC_START + vm_init_off, align); 1018 vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START; 1019 1020 vm->addr = (void *)addr; 1021 1022 vm->next = vmlist; 1023 vmlist = vm; 1024 } 1025 1026 void __init vmalloc_init(void) 1027 { 1028 struct vmap_area *va; 1029 struct vm_struct *tmp; 1030 int i; 1031 1032 for_each_possible_cpu(i) { 1033 struct vmap_block_queue *vbq; 1034 1035 vbq = &per_cpu(vmap_block_queue, i); 1036 spin_lock_init(&vbq->lock); 1037 INIT_LIST_HEAD(&vbq->free); 1038 INIT_LIST_HEAD(&vbq->dirty); 1039 vbq->nr_dirty = 0; 1040 } 1041 1042 /* Import existing vmlist entries. */ 1043 for (tmp = vmlist; tmp; tmp = tmp->next) { 1044 va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT); 1045 va->flags = tmp->flags | VM_VM_AREA; 1046 va->va_start = (unsigned long)tmp->addr; 1047 va->va_end = va->va_start + tmp->size; 1048 __insert_vmap_area(va); 1049 } 1050 1051 vmap_area_pcpu_hole = VMALLOC_END; 1052 1053 vmap_initialized = true; 1054 } 1055 1056 /** 1057 * map_kernel_range_noflush - map kernel VM area with the specified pages 1058 * @addr: start of the VM area to map 1059 * @size: size of the VM area to map 1060 * @prot: page protection flags to use 1061 * @pages: pages to map 1062 * 1063 * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size 1064 * specify should have been allocated using get_vm_area() and its 1065 * friends. 1066 * 1067 * NOTE: 1068 * This function does NOT do any cache flushing. The caller is 1069 * responsible for calling flush_cache_vmap() on to-be-mapped areas 1070 * before calling this function. 1071 * 1072 * RETURNS: 1073 * The number of pages mapped on success, -errno on failure. 1074 */ 1075 int map_kernel_range_noflush(unsigned long addr, unsigned long size, 1076 pgprot_t prot, struct page **pages) 1077 { 1078 return vmap_page_range_noflush(addr, addr + size, prot, pages); 1079 } 1080 1081 /** 1082 * unmap_kernel_range_noflush - unmap kernel VM area 1083 * @addr: start of the VM area to unmap 1084 * @size: size of the VM area to unmap 1085 * 1086 * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size 1087 * specify should have been allocated using get_vm_area() and its 1088 * friends. 1089 * 1090 * NOTE: 1091 * This function does NOT do any cache flushing. The caller is 1092 * responsible for calling flush_cache_vunmap() on to-be-mapped areas 1093 * before calling this function and flush_tlb_kernel_range() after. 1094 */ 1095 void unmap_kernel_range_noflush(unsigned long addr, unsigned long size) 1096 { 1097 vunmap_page_range(addr, addr + size); 1098 } 1099 1100 /** 1101 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB 1102 * @addr: start of the VM area to unmap 1103 * @size: size of the VM area to unmap 1104 * 1105 * Similar to unmap_kernel_range_noflush() but flushes vcache before 1106 * the unmapping and tlb after. 1107 */ 1108 void unmap_kernel_range(unsigned long addr, unsigned long size) 1109 { 1110 unsigned long end = addr + size; 1111 1112 flush_cache_vunmap(addr, end); 1113 vunmap_page_range(addr, end); 1114 flush_tlb_kernel_range(addr, end); 1115 } 1116 1117 int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages) 1118 { 1119 unsigned long addr = (unsigned long)area->addr; 1120 unsigned long end = addr + area->size - PAGE_SIZE; 1121 int err; 1122 1123 err = vmap_page_range(addr, end, prot, *pages); 1124 if (err > 0) { 1125 *pages += err; 1126 err = 0; 1127 } 1128 1129 return err; 1130 } 1131 EXPORT_SYMBOL_GPL(map_vm_area); 1132 1133 /*** Old vmalloc interfaces ***/ 1134 DEFINE_RWLOCK(vmlist_lock); 1135 struct vm_struct *vmlist; 1136 1137 static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, 1138 unsigned long flags, void *caller) 1139 { 1140 struct vm_struct *tmp, **p; 1141 1142 vm->flags = flags; 1143 vm->addr = (void *)va->va_start; 1144 vm->size = va->va_end - va->va_start; 1145 vm->caller = caller; 1146 va->private = vm; 1147 va->flags |= VM_VM_AREA; 1148 1149 write_lock(&vmlist_lock); 1150 for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) { 1151 if (tmp->addr >= vm->addr) 1152 break; 1153 } 1154 vm->next = *p; 1155 *p = vm; 1156 write_unlock(&vmlist_lock); 1157 } 1158 1159 static struct vm_struct *__get_vm_area_node(unsigned long size, 1160 unsigned long align, unsigned long flags, unsigned long start, 1161 unsigned long end, int node, gfp_t gfp_mask, void *caller) 1162 { 1163 static struct vmap_area *va; 1164 struct vm_struct *area; 1165 1166 BUG_ON(in_interrupt()); 1167 if (flags & VM_IOREMAP) { 1168 int bit = fls(size); 1169 1170 if (bit > IOREMAP_MAX_ORDER) 1171 bit = IOREMAP_MAX_ORDER; 1172 else if (bit < PAGE_SHIFT) 1173 bit = PAGE_SHIFT; 1174 1175 align = 1ul << bit; 1176 } 1177 1178 size = PAGE_ALIGN(size); 1179 if (unlikely(!size)) 1180 return NULL; 1181 1182 area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node); 1183 if (unlikely(!area)) 1184 return NULL; 1185 1186 /* 1187 * We always allocate a guard page. 1188 */ 1189 size += PAGE_SIZE; 1190 1191 va = alloc_vmap_area(size, align, start, end, node, gfp_mask); 1192 if (IS_ERR(va)) { 1193 kfree(area); 1194 return NULL; 1195 } 1196 1197 insert_vmalloc_vm(area, va, flags, caller); 1198 return area; 1199 } 1200 1201 struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags, 1202 unsigned long start, unsigned long end) 1203 { 1204 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL, 1205 __builtin_return_address(0)); 1206 } 1207 EXPORT_SYMBOL_GPL(__get_vm_area); 1208 1209 struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, 1210 unsigned long start, unsigned long end, 1211 void *caller) 1212 { 1213 return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL, 1214 caller); 1215 } 1216 1217 /** 1218 * get_vm_area - reserve a contiguous kernel virtual area 1219 * @size: size of the area 1220 * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC 1221 * 1222 * Search an area of @size in the kernel virtual mapping area, 1223 * and reserved it for out purposes. Returns the area descriptor 1224 * on success or %NULL on failure. 1225 */ 1226 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) 1227 { 1228 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END, 1229 -1, GFP_KERNEL, __builtin_return_address(0)); 1230 } 1231 1232 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, 1233 void *caller) 1234 { 1235 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END, 1236 -1, GFP_KERNEL, caller); 1237 } 1238 1239 struct vm_struct *get_vm_area_node(unsigned long size, unsigned long flags, 1240 int node, gfp_t gfp_mask) 1241 { 1242 return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END, 1243 node, gfp_mask, __builtin_return_address(0)); 1244 } 1245 1246 static struct vm_struct *find_vm_area(const void *addr) 1247 { 1248 struct vmap_area *va; 1249 1250 va = find_vmap_area((unsigned long)addr); 1251 if (va && va->flags & VM_VM_AREA) 1252 return va->private; 1253 1254 return NULL; 1255 } 1256 1257 /** 1258 * remove_vm_area - find and remove a continuous kernel virtual area 1259 * @addr: base address 1260 * 1261 * Search for the kernel VM area starting at @addr, and remove it. 1262 * This function returns the found VM area, but using it is NOT safe 1263 * on SMP machines, except for its size or flags. 1264 */ 1265 struct vm_struct *remove_vm_area(const void *addr) 1266 { 1267 struct vmap_area *va; 1268 1269 va = find_vmap_area((unsigned long)addr); 1270 if (va && va->flags & VM_VM_AREA) { 1271 struct vm_struct *vm = va->private; 1272 struct vm_struct *tmp, **p; 1273 /* 1274 * remove from list and disallow access to this vm_struct 1275 * before unmap. (address range confliction is maintained by 1276 * vmap.) 1277 */ 1278 write_lock(&vmlist_lock); 1279 for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next) 1280 ; 1281 *p = tmp->next; 1282 write_unlock(&vmlist_lock); 1283 1284 vmap_debug_free_range(va->va_start, va->va_end); 1285 free_unmap_vmap_area(va); 1286 vm->size -= PAGE_SIZE; 1287 1288 return vm; 1289 } 1290 return NULL; 1291 } 1292 1293 static void __vunmap(const void *addr, int deallocate_pages) 1294 { 1295 struct vm_struct *area; 1296 1297 if (!addr) 1298 return; 1299 1300 if ((PAGE_SIZE-1) & (unsigned long)addr) { 1301 WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr); 1302 return; 1303 } 1304 1305 area = remove_vm_area(addr); 1306 if (unlikely(!area)) { 1307 WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", 1308 addr); 1309 return; 1310 } 1311 1312 debug_check_no_locks_freed(addr, area->size); 1313 debug_check_no_obj_freed(addr, area->size); 1314 1315 if (deallocate_pages) { 1316 int i; 1317 1318 for (i = 0; i < area->nr_pages; i++) { 1319 struct page *page = area->pages[i]; 1320 1321 BUG_ON(!page); 1322 __free_page(page); 1323 } 1324 1325 if (area->flags & VM_VPAGES) 1326 vfree(area->pages); 1327 else 1328 kfree(area->pages); 1329 } 1330 1331 kfree(area); 1332 return; 1333 } 1334 1335 /** 1336 * vfree - release memory allocated by vmalloc() 1337 * @addr: memory base address 1338 * 1339 * Free the virtually continuous memory area starting at @addr, as 1340 * obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is 1341 * NULL, no operation is performed. 1342 * 1343 * Must not be called in interrupt context. 1344 */ 1345 void vfree(const void *addr) 1346 { 1347 BUG_ON(in_interrupt()); 1348 1349 kmemleak_free(addr); 1350 1351 __vunmap(addr, 1); 1352 } 1353 EXPORT_SYMBOL(vfree); 1354 1355 /** 1356 * vunmap - release virtual mapping obtained by vmap() 1357 * @addr: memory base address 1358 * 1359 * Free the virtually contiguous memory area starting at @addr, 1360 * which was created from the page array passed to vmap(). 1361 * 1362 * Must not be called in interrupt context. 1363 */ 1364 void vunmap(const void *addr) 1365 { 1366 BUG_ON(in_interrupt()); 1367 might_sleep(); 1368 __vunmap(addr, 0); 1369 } 1370 EXPORT_SYMBOL(vunmap); 1371 1372 /** 1373 * vmap - map an array of pages into virtually contiguous space 1374 * @pages: array of page pointers 1375 * @count: number of pages to map 1376 * @flags: vm_area->flags 1377 * @prot: page protection for the mapping 1378 * 1379 * Maps @count pages from @pages into contiguous kernel virtual 1380 * space. 1381 */ 1382 void *vmap(struct page **pages, unsigned int count, 1383 unsigned long flags, pgprot_t prot) 1384 { 1385 struct vm_struct *area; 1386 1387 might_sleep(); 1388 1389 if (count > totalram_pages) 1390 return NULL; 1391 1392 area = get_vm_area_caller((count << PAGE_SHIFT), flags, 1393 __builtin_return_address(0)); 1394 if (!area) 1395 return NULL; 1396 1397 if (map_vm_area(area, prot, &pages)) { 1398 vunmap(area->addr); 1399 return NULL; 1400 } 1401 1402 return area->addr; 1403 } 1404 EXPORT_SYMBOL(vmap); 1405 1406 static void *__vmalloc_node(unsigned long size, unsigned long align, 1407 gfp_t gfp_mask, pgprot_t prot, 1408 int node, void *caller); 1409 static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, 1410 pgprot_t prot, int node, void *caller) 1411 { 1412 struct page **pages; 1413 unsigned int nr_pages, array_size, i; 1414 gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; 1415 1416 nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT; 1417 array_size = (nr_pages * sizeof(struct page *)); 1418 1419 area->nr_pages = nr_pages; 1420 /* Please note that the recursion is strictly bounded. */ 1421 if (array_size > PAGE_SIZE) { 1422 pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM, 1423 PAGE_KERNEL, node, caller); 1424 area->flags |= VM_VPAGES; 1425 } else { 1426 pages = kmalloc_node(array_size, nested_gfp, node); 1427 } 1428 area->pages = pages; 1429 area->caller = caller; 1430 if (!area->pages) { 1431 remove_vm_area(area->addr); 1432 kfree(area); 1433 return NULL; 1434 } 1435 1436 for (i = 0; i < area->nr_pages; i++) { 1437 struct page *page; 1438 1439 if (node < 0) 1440 page = alloc_page(gfp_mask); 1441 else 1442 page = alloc_pages_node(node, gfp_mask, 0); 1443 1444 if (unlikely(!page)) { 1445 /* Successfully allocated i pages, free them in __vunmap() */ 1446 area->nr_pages = i; 1447 goto fail; 1448 } 1449 area->pages[i] = page; 1450 } 1451 1452 if (map_vm_area(area, prot, &pages)) 1453 goto fail; 1454 return area->addr; 1455 1456 fail: 1457 vfree(area->addr); 1458 return NULL; 1459 } 1460 1461 void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask, pgprot_t prot) 1462 { 1463 void *addr = __vmalloc_area_node(area, gfp_mask, prot, -1, 1464 __builtin_return_address(0)); 1465 1466 /* 1467 * A ref_count = 3 is needed because the vm_struct and vmap_area 1468 * structures allocated in the __get_vm_area_node() function contain 1469 * references to the virtual address of the vmalloc'ed block. 1470 */ 1471 kmemleak_alloc(addr, area->size - PAGE_SIZE, 3, gfp_mask); 1472 1473 return addr; 1474 } 1475 1476 /** 1477 * __vmalloc_node - allocate virtually contiguous memory 1478 * @size: allocation size 1479 * @align: desired alignment 1480 * @gfp_mask: flags for the page level allocator 1481 * @prot: protection mask for the allocated pages 1482 * @node: node to use for allocation or -1 1483 * @caller: caller's return address 1484 * 1485 * Allocate enough pages to cover @size from the page level 1486 * allocator with @gfp_mask flags. Map them into contiguous 1487 * kernel virtual space, using a pagetable protection of @prot. 1488 */ 1489 static void *__vmalloc_node(unsigned long size, unsigned long align, 1490 gfp_t gfp_mask, pgprot_t prot, 1491 int node, void *caller) 1492 { 1493 struct vm_struct *area; 1494 void *addr; 1495 unsigned long real_size = size; 1496 1497 size = PAGE_ALIGN(size); 1498 if (!size || (size >> PAGE_SHIFT) > totalram_pages) 1499 return NULL; 1500 1501 area = __get_vm_area_node(size, align, VM_ALLOC, VMALLOC_START, 1502 VMALLOC_END, node, gfp_mask, caller); 1503 1504 if (!area) 1505 return NULL; 1506 1507 addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller); 1508 1509 /* 1510 * A ref_count = 3 is needed because the vm_struct and vmap_area 1511 * structures allocated in the __get_vm_area_node() function contain 1512 * references to the virtual address of the vmalloc'ed block. 1513 */ 1514 kmemleak_alloc(addr, real_size, 3, gfp_mask); 1515 1516 return addr; 1517 } 1518 1519 void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) 1520 { 1521 return __vmalloc_node(size, 1, gfp_mask, prot, -1, 1522 __builtin_return_address(0)); 1523 } 1524 EXPORT_SYMBOL(__vmalloc); 1525 1526 /** 1527 * vmalloc - allocate virtually contiguous memory 1528 * @size: allocation size 1529 * Allocate enough pages to cover @size from the page level 1530 * allocator and map them into contiguous kernel virtual space. 1531 * 1532 * For tight control over page level allocator and protection flags 1533 * use __vmalloc() instead. 1534 */ 1535 void *vmalloc(unsigned long size) 1536 { 1537 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL, 1538 -1, __builtin_return_address(0)); 1539 } 1540 EXPORT_SYMBOL(vmalloc); 1541 1542 /** 1543 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace 1544 * @size: allocation size 1545 * 1546 * The resulting memory area is zeroed so it can be mapped to userspace 1547 * without leaking data. 1548 */ 1549 void *vmalloc_user(unsigned long size) 1550 { 1551 struct vm_struct *area; 1552 void *ret; 1553 1554 ret = __vmalloc_node(size, SHMLBA, 1555 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, 1556 PAGE_KERNEL, -1, __builtin_return_address(0)); 1557 if (ret) { 1558 area = find_vm_area(ret); 1559 area->flags |= VM_USERMAP; 1560 } 1561 return ret; 1562 } 1563 EXPORT_SYMBOL(vmalloc_user); 1564 1565 /** 1566 * vmalloc_node - allocate memory on a specific node 1567 * @size: allocation size 1568 * @node: numa node 1569 * 1570 * Allocate enough pages to cover @size from the page level 1571 * allocator and map them into contiguous kernel virtual space. 1572 * 1573 * For tight control over page level allocator and protection flags 1574 * use __vmalloc() instead. 1575 */ 1576 void *vmalloc_node(unsigned long size, int node) 1577 { 1578 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL, 1579 node, __builtin_return_address(0)); 1580 } 1581 EXPORT_SYMBOL(vmalloc_node); 1582 1583 #ifndef PAGE_KERNEL_EXEC 1584 # define PAGE_KERNEL_EXEC PAGE_KERNEL 1585 #endif 1586 1587 /** 1588 * vmalloc_exec - allocate virtually contiguous, executable memory 1589 * @size: allocation size 1590 * 1591 * Kernel-internal function to allocate enough pages to cover @size 1592 * the page level allocator and map them into contiguous and 1593 * executable kernel virtual space. 1594 * 1595 * For tight control over page level allocator and protection flags 1596 * use __vmalloc() instead. 1597 */ 1598 1599 void *vmalloc_exec(unsigned long size) 1600 { 1601 return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC, 1602 -1, __builtin_return_address(0)); 1603 } 1604 1605 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32) 1606 #define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL 1607 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA) 1608 #define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL 1609 #else 1610 #define GFP_VMALLOC32 GFP_KERNEL 1611 #endif 1612 1613 /** 1614 * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) 1615 * @size: allocation size 1616 * 1617 * Allocate enough 32bit PA addressable pages to cover @size from the 1618 * page level allocator and map them into contiguous kernel virtual space. 1619 */ 1620 void *vmalloc_32(unsigned long size) 1621 { 1622 return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL, 1623 -1, __builtin_return_address(0)); 1624 } 1625 EXPORT_SYMBOL(vmalloc_32); 1626 1627 /** 1628 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory 1629 * @size: allocation size 1630 * 1631 * The resulting memory area is 32bit addressable and zeroed so it can be 1632 * mapped to userspace without leaking data. 1633 */ 1634 void *vmalloc_32_user(unsigned long size) 1635 { 1636 struct vm_struct *area; 1637 void *ret; 1638 1639 ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, 1640 -1, __builtin_return_address(0)); 1641 if (ret) { 1642 area = find_vm_area(ret); 1643 area->flags |= VM_USERMAP; 1644 } 1645 return ret; 1646 } 1647 EXPORT_SYMBOL(vmalloc_32_user); 1648 1649 /* 1650 * small helper routine , copy contents to buf from addr. 1651 * If the page is not present, fill zero. 1652 */ 1653 1654 static int aligned_vread(char *buf, char *addr, unsigned long count) 1655 { 1656 struct page *p; 1657 int copied = 0; 1658 1659 while (count) { 1660 unsigned long offset, length; 1661 1662 offset = (unsigned long)addr & ~PAGE_MASK; 1663 length = PAGE_SIZE - offset; 1664 if (length > count) 1665 length = count; 1666 p = vmalloc_to_page(addr); 1667 /* 1668 * To do safe access to this _mapped_ area, we need 1669 * lock. But adding lock here means that we need to add 1670 * overhead of vmalloc()/vfree() calles for this _debug_ 1671 * interface, rarely used. Instead of that, we'll use 1672 * kmap() and get small overhead in this access function. 1673 */ 1674 if (p) { 1675 /* 1676 * we can expect USER0 is not used (see vread/vwrite's 1677 * function description) 1678 */ 1679 void *map = kmap_atomic(p, KM_USER0); 1680 memcpy(buf, map + offset, length); 1681 kunmap_atomic(map, KM_USER0); 1682 } else 1683 memset(buf, 0, length); 1684 1685 addr += length; 1686 buf += length; 1687 copied += length; 1688 count -= length; 1689 } 1690 return copied; 1691 } 1692 1693 static int aligned_vwrite(char *buf, char *addr, unsigned long count) 1694 { 1695 struct page *p; 1696 int copied = 0; 1697 1698 while (count) { 1699 unsigned long offset, length; 1700 1701 offset = (unsigned long)addr & ~PAGE_MASK; 1702 length = PAGE_SIZE - offset; 1703 if (length > count) 1704 length = count; 1705 p = vmalloc_to_page(addr); 1706 /* 1707 * To do safe access to this _mapped_ area, we need 1708 * lock. But adding lock here means that we need to add 1709 * overhead of vmalloc()/vfree() calles for this _debug_ 1710 * interface, rarely used. Instead of that, we'll use 1711 * kmap() and get small overhead in this access function. 1712 */ 1713 if (p) { 1714 /* 1715 * we can expect USER0 is not used (see vread/vwrite's 1716 * function description) 1717 */ 1718 void *map = kmap_atomic(p, KM_USER0); 1719 memcpy(map + offset, buf, length); 1720 kunmap_atomic(map, KM_USER0); 1721 } 1722 addr += length; 1723 buf += length; 1724 copied += length; 1725 count -= length; 1726 } 1727 return copied; 1728 } 1729 1730 /** 1731 * vread() - read vmalloc area in a safe way. 1732 * @buf: buffer for reading data 1733 * @addr: vm address. 1734 * @count: number of bytes to be read. 1735 * 1736 * Returns # of bytes which addr and buf should be increased. 1737 * (same number to @count). Returns 0 if [addr...addr+count) doesn't 1738 * includes any intersect with alive vmalloc area. 1739 * 1740 * This function checks that addr is a valid vmalloc'ed area, and 1741 * copy data from that area to a given buffer. If the given memory range 1742 * of [addr...addr+count) includes some valid address, data is copied to 1743 * proper area of @buf. If there are memory holes, they'll be zero-filled. 1744 * IOREMAP area is treated as memory hole and no copy is done. 1745 * 1746 * If [addr...addr+count) doesn't includes any intersects with alive 1747 * vm_struct area, returns 0. 1748 * @buf should be kernel's buffer. Because this function uses KM_USER0, 1749 * the caller should guarantee KM_USER0 is not used. 1750 * 1751 * Note: In usual ops, vread() is never necessary because the caller 1752 * should know vmalloc() area is valid and can use memcpy(). 1753 * This is for routines which have to access vmalloc area without 1754 * any informaion, as /dev/kmem. 1755 * 1756 */ 1757 1758 long vread(char *buf, char *addr, unsigned long count) 1759 { 1760 struct vm_struct *tmp; 1761 char *vaddr, *buf_start = buf; 1762 unsigned long buflen = count; 1763 unsigned long n; 1764 1765 /* Don't allow overflow */ 1766 if ((unsigned long) addr + count < count) 1767 count = -(unsigned long) addr; 1768 1769 read_lock(&vmlist_lock); 1770 for (tmp = vmlist; count && tmp; tmp = tmp->next) { 1771 vaddr = (char *) tmp->addr; 1772 if (addr >= vaddr + tmp->size - PAGE_SIZE) 1773 continue; 1774 while (addr < vaddr) { 1775 if (count == 0) 1776 goto finished; 1777 *buf = '\0'; 1778 buf++; 1779 addr++; 1780 count--; 1781 } 1782 n = vaddr + tmp->size - PAGE_SIZE - addr; 1783 if (n > count) 1784 n = count; 1785 if (!(tmp->flags & VM_IOREMAP)) 1786 aligned_vread(buf, addr, n); 1787 else /* IOREMAP area is treated as memory hole */ 1788 memset(buf, 0, n); 1789 buf += n; 1790 addr += n; 1791 count -= n; 1792 } 1793 finished: 1794 read_unlock(&vmlist_lock); 1795 1796 if (buf == buf_start) 1797 return 0; 1798 /* zero-fill memory holes */ 1799 if (buf != buf_start + buflen) 1800 memset(buf, 0, buflen - (buf - buf_start)); 1801 1802 return buflen; 1803 } 1804 1805 /** 1806 * vwrite() - write vmalloc area in a safe way. 1807 * @buf: buffer for source data 1808 * @addr: vm address. 1809 * @count: number of bytes to be read. 1810 * 1811 * Returns # of bytes which addr and buf should be incresed. 1812 * (same number to @count). 1813 * If [addr...addr+count) doesn't includes any intersect with valid 1814 * vmalloc area, returns 0. 1815 * 1816 * This function checks that addr is a valid vmalloc'ed area, and 1817 * copy data from a buffer to the given addr. If specified range of 1818 * [addr...addr+count) includes some valid address, data is copied from 1819 * proper area of @buf. If there are memory holes, no copy to hole. 1820 * IOREMAP area is treated as memory hole and no copy is done. 1821 * 1822 * If [addr...addr+count) doesn't includes any intersects with alive 1823 * vm_struct area, returns 0. 1824 * @buf should be kernel's buffer. Because this function uses KM_USER0, 1825 * the caller should guarantee KM_USER0 is not used. 1826 * 1827 * Note: In usual ops, vwrite() is never necessary because the caller 1828 * should know vmalloc() area is valid and can use memcpy(). 1829 * This is for routines which have to access vmalloc area without 1830 * any informaion, as /dev/kmem. 1831 * 1832 * The caller should guarantee KM_USER1 is not used. 1833 */ 1834 1835 long vwrite(char *buf, char *addr, unsigned long count) 1836 { 1837 struct vm_struct *tmp; 1838 char *vaddr; 1839 unsigned long n, buflen; 1840 int copied = 0; 1841 1842 /* Don't allow overflow */ 1843 if ((unsigned long) addr + count < count) 1844 count = -(unsigned long) addr; 1845 buflen = count; 1846 1847 read_lock(&vmlist_lock); 1848 for (tmp = vmlist; count && tmp; tmp = tmp->next) { 1849 vaddr = (char *) tmp->addr; 1850 if (addr >= vaddr + tmp->size - PAGE_SIZE) 1851 continue; 1852 while (addr < vaddr) { 1853 if (count == 0) 1854 goto finished; 1855 buf++; 1856 addr++; 1857 count--; 1858 } 1859 n = vaddr + tmp->size - PAGE_SIZE - addr; 1860 if (n > count) 1861 n = count; 1862 if (!(tmp->flags & VM_IOREMAP)) { 1863 aligned_vwrite(buf, addr, n); 1864 copied++; 1865 } 1866 buf += n; 1867 addr += n; 1868 count -= n; 1869 } 1870 finished: 1871 read_unlock(&vmlist_lock); 1872 if (!copied) 1873 return 0; 1874 return buflen; 1875 } 1876 1877 /** 1878 * remap_vmalloc_range - map vmalloc pages to userspace 1879 * @vma: vma to cover (map full range of vma) 1880 * @addr: vmalloc memory 1881 * @pgoff: number of pages into addr before first page to map 1882 * 1883 * Returns: 0 for success, -Exxx on failure 1884 * 1885 * This function checks that addr is a valid vmalloc'ed area, and 1886 * that it is big enough to cover the vma. Will return failure if 1887 * that criteria isn't met. 1888 * 1889 * Similar to remap_pfn_range() (see mm/memory.c) 1890 */ 1891 int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, 1892 unsigned long pgoff) 1893 { 1894 struct vm_struct *area; 1895 unsigned long uaddr = vma->vm_start; 1896 unsigned long usize = vma->vm_end - vma->vm_start; 1897 1898 if ((PAGE_SIZE-1) & (unsigned long)addr) 1899 return -EINVAL; 1900 1901 area = find_vm_area(addr); 1902 if (!area) 1903 return -EINVAL; 1904 1905 if (!(area->flags & VM_USERMAP)) 1906 return -EINVAL; 1907 1908 if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE) 1909 return -EINVAL; 1910 1911 addr += pgoff << PAGE_SHIFT; 1912 do { 1913 struct page *page = vmalloc_to_page(addr); 1914 int ret; 1915 1916 ret = vm_insert_page(vma, uaddr, page); 1917 if (ret) 1918 return ret; 1919 1920 uaddr += PAGE_SIZE; 1921 addr += PAGE_SIZE; 1922 usize -= PAGE_SIZE; 1923 } while (usize > 0); 1924 1925 /* Prevent "things" like memory migration? VM_flags need a cleanup... */ 1926 vma->vm_flags |= VM_RESERVED; 1927 1928 return 0; 1929 } 1930 EXPORT_SYMBOL(remap_vmalloc_range); 1931 1932 /* 1933 * Implement a stub for vmalloc_sync_all() if the architecture chose not to 1934 * have one. 1935 */ 1936 void __attribute__((weak)) vmalloc_sync_all(void) 1937 { 1938 } 1939 1940 1941 static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data) 1942 { 1943 /* apply_to_page_range() does all the hard work. */ 1944 return 0; 1945 } 1946 1947 /** 1948 * alloc_vm_area - allocate a range of kernel address space 1949 * @size: size of the area 1950 * 1951 * Returns: NULL on failure, vm_struct on success 1952 * 1953 * This function reserves a range of kernel address space, and 1954 * allocates pagetables to map that range. No actual mappings 1955 * are created. If the kernel address space is not shared 1956 * between processes, it syncs the pagetable across all 1957 * processes. 1958 */ 1959 struct vm_struct *alloc_vm_area(size_t size) 1960 { 1961 struct vm_struct *area; 1962 1963 area = get_vm_area_caller(size, VM_IOREMAP, 1964 __builtin_return_address(0)); 1965 if (area == NULL) 1966 return NULL; 1967 1968 /* 1969 * This ensures that page tables are constructed for this region 1970 * of kernel virtual address space and mapped into init_mm. 1971 */ 1972 if (apply_to_page_range(&init_mm, (unsigned long)area->addr, 1973 area->size, f, NULL)) { 1974 free_vm_area(area); 1975 return NULL; 1976 } 1977 1978 /* Make sure the pagetables are constructed in process kernel 1979 mappings */ 1980 vmalloc_sync_all(); 1981 1982 return area; 1983 } 1984 EXPORT_SYMBOL_GPL(alloc_vm_area); 1985 1986 void free_vm_area(struct vm_struct *area) 1987 { 1988 struct vm_struct *ret; 1989 ret = remove_vm_area(area->addr); 1990 BUG_ON(ret != area); 1991 kfree(area); 1992 } 1993 EXPORT_SYMBOL_GPL(free_vm_area); 1994 1995 static struct vmap_area *node_to_va(struct rb_node *n) 1996 { 1997 return n ? rb_entry(n, struct vmap_area, rb_node) : NULL; 1998 } 1999 2000 /** 2001 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end 2002 * @end: target address 2003 * @pnext: out arg for the next vmap_area 2004 * @pprev: out arg for the previous vmap_area 2005 * 2006 * Returns: %true if either or both of next and prev are found, 2007 * %false if no vmap_area exists 2008 * 2009 * Find vmap_areas end addresses of which enclose @end. ie. if not 2010 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end. 2011 */ 2012 static bool pvm_find_next_prev(unsigned long end, 2013 struct vmap_area **pnext, 2014 struct vmap_area **pprev) 2015 { 2016 struct rb_node *n = vmap_area_root.rb_node; 2017 struct vmap_area *va = NULL; 2018 2019 while (n) { 2020 va = rb_entry(n, struct vmap_area, rb_node); 2021 if (end < va->va_end) 2022 n = n->rb_left; 2023 else if (end > va->va_end) 2024 n = n->rb_right; 2025 else 2026 break; 2027 } 2028 2029 if (!va) 2030 return false; 2031 2032 if (va->va_end > end) { 2033 *pnext = va; 2034 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node)); 2035 } else { 2036 *pprev = va; 2037 *pnext = node_to_va(rb_next(&(*pprev)->rb_node)); 2038 } 2039 return true; 2040 } 2041 2042 /** 2043 * pvm_determine_end - find the highest aligned address between two vmap_areas 2044 * @pnext: in/out arg for the next vmap_area 2045 * @pprev: in/out arg for the previous vmap_area 2046 * @align: alignment 2047 * 2048 * Returns: determined end address 2049 * 2050 * Find the highest aligned address between *@pnext and *@pprev below 2051 * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned 2052 * down address is between the end addresses of the two vmap_areas. 2053 * 2054 * Please note that the address returned by this function may fall 2055 * inside *@pnext vmap_area. The caller is responsible for checking 2056 * that. 2057 */ 2058 static unsigned long pvm_determine_end(struct vmap_area **pnext, 2059 struct vmap_area **pprev, 2060 unsigned long align) 2061 { 2062 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); 2063 unsigned long addr; 2064 2065 if (*pnext) 2066 addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end); 2067 else 2068 addr = vmalloc_end; 2069 2070 while (*pprev && (*pprev)->va_end > addr) { 2071 *pnext = *pprev; 2072 *pprev = node_to_va(rb_prev(&(*pnext)->rb_node)); 2073 } 2074 2075 return addr; 2076 } 2077 2078 /** 2079 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator 2080 * @offsets: array containing offset of each area 2081 * @sizes: array containing size of each area 2082 * @nr_vms: the number of areas to allocate 2083 * @align: alignment, all entries in @offsets and @sizes must be aligned to this 2084 * @gfp_mask: allocation mask 2085 * 2086 * Returns: kmalloc'd vm_struct pointer array pointing to allocated 2087 * vm_structs on success, %NULL on failure 2088 * 2089 * Percpu allocator wants to use congruent vm areas so that it can 2090 * maintain the offsets among percpu areas. This function allocates 2091 * congruent vmalloc areas for it. These areas tend to be scattered 2092 * pretty far, distance between two areas easily going up to 2093 * gigabytes. To avoid interacting with regular vmallocs, these areas 2094 * are allocated from top. 2095 * 2096 * Despite its complicated look, this allocator is rather simple. It 2097 * does everything top-down and scans areas from the end looking for 2098 * matching slot. While scanning, if any of the areas overlaps with 2099 * existing vmap_area, the base address is pulled down to fit the 2100 * area. Scanning is repeated till all the areas fit and then all 2101 * necessary data structres are inserted and the result is returned. 2102 */ 2103 struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, 2104 const size_t *sizes, int nr_vms, 2105 size_t align, gfp_t gfp_mask) 2106 { 2107 const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align); 2108 const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); 2109 struct vmap_area **vas, *prev, *next; 2110 struct vm_struct **vms; 2111 int area, area2, last_area, term_area; 2112 unsigned long base, start, end, last_end; 2113 bool purged = false; 2114 2115 gfp_mask &= GFP_RECLAIM_MASK; 2116 2117 /* verify parameters and allocate data structures */ 2118 BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align)); 2119 for (last_area = 0, area = 0; area < nr_vms; area++) { 2120 start = offsets[area]; 2121 end = start + sizes[area]; 2122 2123 /* is everything aligned properly? */ 2124 BUG_ON(!IS_ALIGNED(offsets[area], align)); 2125 BUG_ON(!IS_ALIGNED(sizes[area], align)); 2126 2127 /* detect the area with the highest address */ 2128 if (start > offsets[last_area]) 2129 last_area = area; 2130 2131 for (area2 = 0; area2 < nr_vms; area2++) { 2132 unsigned long start2 = offsets[area2]; 2133 unsigned long end2 = start2 + sizes[area2]; 2134 2135 if (area2 == area) 2136 continue; 2137 2138 BUG_ON(start2 >= start && start2 < end); 2139 BUG_ON(end2 <= end && end2 > start); 2140 } 2141 } 2142 last_end = offsets[last_area] + sizes[last_area]; 2143 2144 if (vmalloc_end - vmalloc_start < last_end) { 2145 WARN_ON(true); 2146 return NULL; 2147 } 2148 2149 vms = kzalloc(sizeof(vms[0]) * nr_vms, gfp_mask); 2150 vas = kzalloc(sizeof(vas[0]) * nr_vms, gfp_mask); 2151 if (!vas || !vms) 2152 goto err_free; 2153 2154 for (area = 0; area < nr_vms; area++) { 2155 vas[area] = kzalloc(sizeof(struct vmap_area), gfp_mask); 2156 vms[area] = kzalloc(sizeof(struct vm_struct), gfp_mask); 2157 if (!vas[area] || !vms[area]) 2158 goto err_free; 2159 } 2160 retry: 2161 spin_lock(&vmap_area_lock); 2162 2163 /* start scanning - we scan from the top, begin with the last area */ 2164 area = term_area = last_area; 2165 start = offsets[area]; 2166 end = start + sizes[area]; 2167 2168 if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) { 2169 base = vmalloc_end - last_end; 2170 goto found; 2171 } 2172 base = pvm_determine_end(&next, &prev, align) - end; 2173 2174 while (true) { 2175 BUG_ON(next && next->va_end <= base + end); 2176 BUG_ON(prev && prev->va_end > base + end); 2177 2178 /* 2179 * base might have underflowed, add last_end before 2180 * comparing. 2181 */ 2182 if (base + last_end < vmalloc_start + last_end) { 2183 spin_unlock(&vmap_area_lock); 2184 if (!purged) { 2185 purge_vmap_area_lazy(); 2186 purged = true; 2187 goto retry; 2188 } 2189 goto err_free; 2190 } 2191 2192 /* 2193 * If next overlaps, move base downwards so that it's 2194 * right below next and then recheck. 2195 */ 2196 if (next && next->va_start < base + end) { 2197 base = pvm_determine_end(&next, &prev, align) - end; 2198 term_area = area; 2199 continue; 2200 } 2201 2202 /* 2203 * If prev overlaps, shift down next and prev and move 2204 * base so that it's right below new next and then 2205 * recheck. 2206 */ 2207 if (prev && prev->va_end > base + start) { 2208 next = prev; 2209 prev = node_to_va(rb_prev(&next->rb_node)); 2210 base = pvm_determine_end(&next, &prev, align) - end; 2211 term_area = area; 2212 continue; 2213 } 2214 2215 /* 2216 * This area fits, move on to the previous one. If 2217 * the previous one is the terminal one, we're done. 2218 */ 2219 area = (area + nr_vms - 1) % nr_vms; 2220 if (area == term_area) 2221 break; 2222 start = offsets[area]; 2223 end = start + sizes[area]; 2224 pvm_find_next_prev(base + end, &next, &prev); 2225 } 2226 found: 2227 /* we've found a fitting base, insert all va's */ 2228 for (area = 0; area < nr_vms; area++) { 2229 struct vmap_area *va = vas[area]; 2230 2231 va->va_start = base + offsets[area]; 2232 va->va_end = va->va_start + sizes[area]; 2233 __insert_vmap_area(va); 2234 } 2235 2236 vmap_area_pcpu_hole = base + offsets[last_area]; 2237 2238 spin_unlock(&vmap_area_lock); 2239 2240 /* insert all vm's */ 2241 for (area = 0; area < nr_vms; area++) 2242 insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC, 2243 pcpu_get_vm_areas); 2244 2245 kfree(vas); 2246 return vms; 2247 2248 err_free: 2249 for (area = 0; area < nr_vms; area++) { 2250 if (vas) 2251 kfree(vas[area]); 2252 if (vms) 2253 kfree(vms[area]); 2254 } 2255 kfree(vas); 2256 kfree(vms); 2257 return NULL; 2258 } 2259 2260 /** 2261 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator 2262 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas() 2263 * @nr_vms: the number of allocated areas 2264 * 2265 * Free vm_structs and the array allocated by pcpu_get_vm_areas(). 2266 */ 2267 void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) 2268 { 2269 int i; 2270 2271 for (i = 0; i < nr_vms; i++) 2272 free_vm_area(vms[i]); 2273 kfree(vms); 2274 } 2275 2276 #ifdef CONFIG_PROC_FS 2277 static void *s_start(struct seq_file *m, loff_t *pos) 2278 { 2279 loff_t n = *pos; 2280 struct vm_struct *v; 2281 2282 read_lock(&vmlist_lock); 2283 v = vmlist; 2284 while (n > 0 && v) { 2285 n--; 2286 v = v->next; 2287 } 2288 if (!n) 2289 return v; 2290 2291 return NULL; 2292 2293 } 2294 2295 static void *s_next(struct seq_file *m, void *p, loff_t *pos) 2296 { 2297 struct vm_struct *v = p; 2298 2299 ++*pos; 2300 return v->next; 2301 } 2302 2303 static void s_stop(struct seq_file *m, void *p) 2304 { 2305 read_unlock(&vmlist_lock); 2306 } 2307 2308 static void show_numa_info(struct seq_file *m, struct vm_struct *v) 2309 { 2310 if (NUMA_BUILD) { 2311 unsigned int nr, *counters = m->private; 2312 2313 if (!counters) 2314 return; 2315 2316 memset(counters, 0, nr_node_ids * sizeof(unsigned int)); 2317 2318 for (nr = 0; nr < v->nr_pages; nr++) 2319 counters[page_to_nid(v->pages[nr])]++; 2320 2321 for_each_node_state(nr, N_HIGH_MEMORY) 2322 if (counters[nr]) 2323 seq_printf(m, " N%u=%u", nr, counters[nr]); 2324 } 2325 } 2326 2327 static int s_show(struct seq_file *m, void *p) 2328 { 2329 struct vm_struct *v = p; 2330 2331 seq_printf(m, "0x%p-0x%p %7ld", 2332 v->addr, v->addr + v->size, v->size); 2333 2334 if (v->caller) { 2335 char buff[KSYM_SYMBOL_LEN]; 2336 2337 seq_putc(m, ' '); 2338 sprint_symbol(buff, (unsigned long)v->caller); 2339 seq_puts(m, buff); 2340 } 2341 2342 if (v->nr_pages) 2343 seq_printf(m, " pages=%d", v->nr_pages); 2344 2345 if (v->phys_addr) 2346 seq_printf(m, " phys=%lx", v->phys_addr); 2347 2348 if (v->flags & VM_IOREMAP) 2349 seq_printf(m, " ioremap"); 2350 2351 if (v->flags & VM_ALLOC) 2352 seq_printf(m, " vmalloc"); 2353 2354 if (v->flags & VM_MAP) 2355 seq_printf(m, " vmap"); 2356 2357 if (v->flags & VM_USERMAP) 2358 seq_printf(m, " user"); 2359 2360 if (v->flags & VM_VPAGES) 2361 seq_printf(m, " vpages"); 2362 2363 show_numa_info(m, v); 2364 seq_putc(m, '\n'); 2365 return 0; 2366 } 2367 2368 static const struct seq_operations vmalloc_op = { 2369 .start = s_start, 2370 .next = s_next, 2371 .stop = s_stop, 2372 .show = s_show, 2373 }; 2374 2375 static int vmalloc_open(struct inode *inode, struct file *file) 2376 { 2377 unsigned int *ptr = NULL; 2378 int ret; 2379 2380 if (NUMA_BUILD) 2381 ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL); 2382 ret = seq_open(file, &vmalloc_op); 2383 if (!ret) { 2384 struct seq_file *m = file->private_data; 2385 m->private = ptr; 2386 } else 2387 kfree(ptr); 2388 return ret; 2389 } 2390 2391 static const struct file_operations proc_vmalloc_operations = { 2392 .open = vmalloc_open, 2393 .read = seq_read, 2394 .llseek = seq_lseek, 2395 .release = seq_release_private, 2396 }; 2397 2398 static int __init proc_vmalloc_init(void) 2399 { 2400 proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations); 2401 return 0; 2402 } 2403 module_init(proc_vmalloc_init); 2404 #endif 2405 2406