vmalloc.c 68.3 KB
Newer Older
Linus Torvalds's avatar
Linus Torvalds committed
1 2 3 4 5 6 7
/*
 *  linux/mm/vmalloc.c
 *
 *  Copyright (C) 1993  Linus Torvalds
 *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
 *  SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
 *  Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
Christoph Lameter's avatar
Christoph Lameter committed
8
 *  Numa awareness, Christoph Lameter, SGI, June 2005
Linus Torvalds's avatar
Linus Torvalds committed
9 10
 */

Nick Piggin's avatar
Nick Piggin committed
11
#include <linux/vmalloc.h>
Linus Torvalds's avatar
Linus Torvalds committed
12 13 14
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/highmem.h>
15
#include <linux/sched.h>
Linus Torvalds's avatar
Linus Torvalds committed
16 17 18
#include <linux/slab.h>
#include <linux/spinlock.h>
#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>
Nick Piggin's avatar
Nick Piggin committed
23 24 25 26
#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
27
#include <linux/pfn.h>
28
#include <linux/kmemleak.h>
Arun Sharma's avatar
Arun Sharma committed
29
#include <linux/atomic.h>
30
#include <linux/compiler.h>
31
#include <linux/llist.h>
32

Linus Torvalds's avatar
Linus Torvalds committed
33 34
#include <asm/uaccess.h>
#include <asm/tlbflush.h>
35
#include <asm/shmparam.h>
Linus Torvalds's avatar
Linus Torvalds committed
36

37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55
struct vfree_deferred {
	struct llist_head list;
	struct work_struct wq;
};
static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);

static void __vunmap(const void *, int);

static void free_work(struct work_struct *w)
{
	struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
	struct llist_node *llnode = llist_del_all(&p->list);
	while (llnode) {
		void *p = llnode;
		llnode = llist_next(llnode);
		__vunmap(p, 1);
	}
}

Nick Piggin's avatar
Nick Piggin committed
56
/*** Page table manipulation functions ***/
57

Linus Torvalds's avatar
Linus Torvalds committed
58 59 60 61 62 63 64 65 66 67 68
static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end)
{
	pte_t *pte;

	pte = pte_offset_kernel(pmd, addr);
	do {
		pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
		WARN_ON(!pte_none(ptent) && !pte_present(ptent));
	} while (pte++, addr += PAGE_SIZE, addr != end);
}

Nick Piggin's avatar
Nick Piggin committed
69
static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
Linus Torvalds's avatar
Linus Torvalds committed
70 71 72 73 74 75 76 77 78 79 80 81 82
{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_offset(pud, addr);
	do {
		next = pmd_addr_end(addr, end);
		if (pmd_none_or_clear_bad(pmd))
			continue;
		vunmap_pte_range(pmd, addr, next);
	} while (pmd++, addr = next, addr != end);
}

Nick Piggin's avatar
Nick Piggin committed
83
static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
Linus Torvalds's avatar
Linus Torvalds committed
84 85 86 87 88 89 90 91 92 93 94 95 96
{
	pud_t *pud;
	unsigned long next;

	pud = pud_offset(pgd, addr);
	do {
		next = pud_addr_end(addr, end);
		if (pud_none_or_clear_bad(pud))
			continue;
		vunmap_pmd_range(pud, addr, next);
	} while (pud++, addr = next, addr != end);
}

Nick Piggin's avatar
Nick Piggin committed
97
static void vunmap_page_range(unsigned long addr, unsigned long end)
Linus Torvalds's avatar
Linus Torvalds committed
98 99 100 101 102 103 104 105 106 107 108 109 110 111 112
{
	pgd_t *pgd;
	unsigned long next;

	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
		if (pgd_none_or_clear_bad(pgd))
			continue;
		vunmap_pud_range(pgd, addr, next);
	} while (pgd++, addr = next, addr != end);
}

static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
Nick Piggin's avatar
Nick Piggin committed
113
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
Linus Torvalds's avatar
Linus Torvalds committed
114 115 116
{
	pte_t *pte;

Nick Piggin's avatar
Nick Piggin committed
117 118 119 120 121
	/*
	 * nr is a running index into the array which helps higher level
	 * callers keep track of where we're up to.
	 */

122
	pte = pte_alloc_kernel(pmd, addr);
Linus Torvalds's avatar
Linus Torvalds committed
123 124 125
	if (!pte)
		return -ENOMEM;
	do {
Nick Piggin's avatar
Nick Piggin committed
126 127 128 129 130
		struct page *page = pages[*nr];

		if (WARN_ON(!pte_none(*pte)))
			return -EBUSY;
		if (WARN_ON(!page))
Linus Torvalds's avatar
Linus Torvalds committed
131 132
			return -ENOMEM;
		set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
Nick Piggin's avatar
Nick Piggin committed
133
		(*nr)++;
Linus Torvalds's avatar
Linus Torvalds committed
134 135 136 137
	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
138 139
static int vmap_pmd_range(pud_t *pud, unsigned long addr,
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
Linus Torvalds's avatar
Linus Torvalds committed
140 141 142 143 144 145 146 147 148
{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_alloc(&init_mm, pud, addr);
	if (!pmd)
		return -ENOMEM;
	do {
		next = pmd_addr_end(addr, end);
Nick Piggin's avatar
Nick Piggin committed
149
		if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
Linus Torvalds's avatar
Linus Torvalds committed
150 151 152 153 154
			return -ENOMEM;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
155 156
static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
Linus Torvalds's avatar
Linus Torvalds committed
157 158 159 160 161 162 163 164 165
{
	pud_t *pud;
	unsigned long next;

	pud = pud_alloc(&init_mm, pgd, addr);
	if (!pud)
		return -ENOMEM;
	do {
		next = pud_addr_end(addr, end);
Nick Piggin's avatar
Nick Piggin committed
166
		if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
Linus Torvalds's avatar
Linus Torvalds committed
167 168 169 170 171
			return -ENOMEM;
	} while (pud++, addr = next, addr != end);
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
172 173 174 175 176 177
/*
 * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and
 * will have pfns corresponding to the "pages" array.
 *
 * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N]
 */
178 179
static int vmap_page_range_noflush(unsigned long start, unsigned long end,
				   pgprot_t prot, struct page **pages)
Linus Torvalds's avatar
Linus Torvalds committed
180 181 182
{
	pgd_t *pgd;
	unsigned long next;
183
	unsigned long addr = start;
Nick Piggin's avatar
Nick Piggin committed
184 185
	int err = 0;
	int nr = 0;
Linus Torvalds's avatar
Linus Torvalds committed
186 187 188 189 190

	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
Nick Piggin's avatar
Nick Piggin committed
191
		err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
Linus Torvalds's avatar
Linus Torvalds committed
192
		if (err)
193
			return err;
Linus Torvalds's avatar
Linus Torvalds committed
194
	} while (pgd++, addr = next, addr != end);
Nick Piggin's avatar
Nick Piggin committed
195 196

	return nr;
Linus Torvalds's avatar
Linus Torvalds committed
197 198
}

199 200 201 202 203 204 205 206 207 208
static int vmap_page_range(unsigned long start, unsigned long end,
			   pgprot_t prot, struct page **pages)
{
	int ret;

	ret = vmap_page_range_noflush(start, end, prot, pages);
	flush_cache_vmap(start, end);
	return ret;
}

209
int is_vmalloc_or_module_addr(const void *x)
210 211
{
	/*
212
	 * ARM, x86-64 and sparc64 put modules in a special place,
213 214 215 216 217 218 219 220 221 222 223
	 * and fall back on vmalloc() if that fails. Others
	 * just put it in the vmalloc space.
	 */
#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
	unsigned long addr = (unsigned long)x;
	if (addr >= MODULES_VADDR && addr < MODULES_END)
		return 1;
#endif
	return is_vmalloc_addr(x);
}

224
/*
225
 * Walk a vmap address to the struct page it maps.
226
 */
227
struct page *vmalloc_to_page(const void *vmalloc_addr)
228 229
{
	unsigned long addr = (unsigned long) vmalloc_addr;
230
	struct page *page = NULL;
231 232
	pgd_t *pgd = pgd_offset_k(addr);

233 234 235 236
	/*
	 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
	 * architectures that do not vmalloc module space
	 */
237
	VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
Jiri Slaby's avatar
Jiri Slaby committed
238

239
	if (!pgd_none(*pgd)) {
Nick Piggin's avatar
Nick Piggin committed
240
		pud_t *pud = pud_offset(pgd, addr);
241
		if (!pud_none(*pud)) {
Nick Piggin's avatar
Nick Piggin committed
242
			pmd_t *pmd = pmd_offset(pud, addr);
243
			if (!pmd_none(*pmd)) {
Nick Piggin's avatar
Nick Piggin committed
244 245
				pte_t *ptep, pte;

246 247 248
				ptep = pte_offset_map(pmd, addr);
				pte = *ptep;
				if (pte_present(pte))
249
					page = pte_page(pte);
250 251 252 253
				pte_unmap(ptep);
			}
		}
	}
254
	return page;
255
}
256
EXPORT_SYMBOL(vmalloc_to_page);
257 258

/*
259
 * Map a vmalloc()-space virtual address to the physical page frame number.
260
 */
261
unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
262
{
263
	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
264
}
265
EXPORT_SYMBOL(vmalloc_to_pfn);
266

Nick Piggin's avatar
Nick Piggin committed
267 268 269 270 271 272 273 274

/*** Global kva allocator ***/

#define VM_LAZY_FREE	0x01
#define VM_LAZY_FREEING	0x02
#define VM_VM_AREA	0x04

static DEFINE_SPINLOCK(vmap_area_lock);
275 276
/* Export for kexec only */
LIST_HEAD(vmap_area_list);
Nick Piggin's avatar
Nick Piggin committed
277 278 279 280 281 282 283 284
static struct rb_root vmap_area_root = RB_ROOT;

/* The vmap cache globals are protected by vmap_area_lock */
static struct rb_node *free_vmap_cache;
static unsigned long cached_hole_size;
static unsigned long cached_vstart;
static unsigned long cached_align;

285
static unsigned long vmap_area_pcpu_hole;
Nick Piggin's avatar
Nick Piggin committed
286 287

static struct vmap_area *__find_vmap_area(unsigned long addr)
Linus Torvalds's avatar
Linus Torvalds committed
288
{
Nick Piggin's avatar
Nick Piggin committed
289 290 291 292 293 294 295 296
	struct rb_node *n = vmap_area_root.rb_node;

	while (n) {
		struct vmap_area *va;

		va = rb_entry(n, struct vmap_area, rb_node);
		if (addr < va->va_start)
			n = n->rb_left;
297
		else if (addr >= va->va_end)
Nick Piggin's avatar
Nick Piggin committed
298 299 300 301 302 303 304 305 306 307 308 309 310 311 312
			n = n->rb_right;
		else
			return va;
	}

	return NULL;
}

static void __insert_vmap_area(struct vmap_area *va)
{
	struct rb_node **p = &vmap_area_root.rb_node;
	struct rb_node *parent = NULL;
	struct rb_node *tmp;

	while (*p) {
313
		struct vmap_area *tmp_va;
Nick Piggin's avatar
Nick Piggin committed
314 315

		parent = *p;
316 317
		tmp_va = rb_entry(parent, struct vmap_area, rb_node);
		if (va->va_start < tmp_va->va_end)
Nick Piggin's avatar
Nick Piggin committed
318
			p = &(*p)->rb_left;
319
		else if (va->va_end > tmp_va->va_start)
Nick Piggin's avatar
Nick Piggin committed
320 321 322 323 324 325 326 327
			p = &(*p)->rb_right;
		else
			BUG();
	}

	rb_link_node(&va->rb_node, parent, p);
	rb_insert_color(&va->rb_node, &vmap_area_root);

328
	/* address-sort this list */
Nick Piggin's avatar
Nick Piggin committed
329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350
	tmp = rb_prev(&va->rb_node);
	if (tmp) {
		struct vmap_area *prev;
		prev = rb_entry(tmp, struct vmap_area, rb_node);
		list_add_rcu(&va->list, &prev->list);
	} else
		list_add_rcu(&va->list, &vmap_area_list);
}

static void purge_vmap_area_lazy(void);

/*
 * Allocate a region of KVA of the specified size and alignment, within the
 * vstart and vend.
 */
static struct vmap_area *alloc_vmap_area(unsigned long size,
				unsigned long align,
				unsigned long vstart, unsigned long vend,
				int node, gfp_t gfp_mask)
{
	struct vmap_area *va;
	struct rb_node *n;
Linus Torvalds's avatar
Linus Torvalds committed
351
	unsigned long addr;
Nick Piggin's avatar
Nick Piggin committed
352
	int purged = 0;
Nick Piggin's avatar
Nick Piggin committed
353
	struct vmap_area *first;
Nick Piggin's avatar
Nick Piggin committed
354

Nick Piggin's avatar
Nick Piggin committed
355
	BUG_ON(!size);
Nick Piggin's avatar
Nick Piggin committed
356
	BUG_ON(size & ~PAGE_MASK);
Nick Piggin's avatar
Nick Piggin committed
357
	BUG_ON(!is_power_of_2(align));
Nick Piggin's avatar
Nick Piggin committed
358 359 360 361 362 363

	va = kmalloc_node(sizeof(struct vmap_area),
			gfp_mask & GFP_RECLAIM_MASK, node);
	if (unlikely(!va))
		return ERR_PTR(-ENOMEM);

364 365 366 367 368 369
	/*
	 * Only scan the relevant parts containing pointers to other objects
	 * to avoid false negatives.
	 */
	kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask & GFP_RECLAIM_MASK);

Nick Piggin's avatar
Nick Piggin committed
370 371
retry:
	spin_lock(&vmap_area_lock);
Nick Piggin's avatar
Nick Piggin committed
372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395
	/*
	 * Invalidate cache if we have more permissive parameters.
	 * cached_hole_size notes the largest hole noticed _below_
	 * the vmap_area cached in free_vmap_cache: if size fits
	 * into that hole, we want to scan from vstart to reuse
	 * the hole instead of allocating above free_vmap_cache.
	 * Note that __free_vmap_area may update free_vmap_cache
	 * without updating cached_hole_size or cached_align.
	 */
	if (!free_vmap_cache ||
			size < cached_hole_size ||
			vstart < cached_vstart ||
			align < cached_align) {
nocache:
		cached_hole_size = 0;
		free_vmap_cache = NULL;
	}
	/* record if we encounter less permissive parameters */
	cached_vstart = vstart;
	cached_align = align;

	/* find starting point for our search */
	if (free_vmap_cache) {
		first = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
396
		addr = ALIGN(first->va_end, align);
Nick Piggin's avatar
Nick Piggin committed
397 398
		if (addr < vstart)
			goto nocache;
399
		if (addr + size < addr)
Nick Piggin's avatar
Nick Piggin committed
400 401 402 403
			goto overflow;

	} else {
		addr = ALIGN(vstart, align);
404
		if (addr + size < addr)
Nick Piggin's avatar
Nick Piggin committed
405 406 407 408 409 410
			goto overflow;

		n = vmap_area_root.rb_node;
		first = NULL;

		while (n) {
Nick Piggin's avatar
Nick Piggin committed
411 412 413 414
			struct vmap_area *tmp;
			tmp = rb_entry(n, struct vmap_area, rb_node);
			if (tmp->va_end >= addr) {
				first = tmp;
Nick Piggin's avatar
Nick Piggin committed
415 416 417 418
				if (tmp->va_start <= addr)
					break;
				n = n->rb_left;
			} else
Nick Piggin's avatar
Nick Piggin committed
419
				n = n->rb_right;
Nick Piggin's avatar
Nick Piggin committed
420
		}
Nick Piggin's avatar
Nick Piggin committed
421 422 423 424

		if (!first)
			goto found;
	}
Nick Piggin's avatar
Nick Piggin committed
425 426

	/* from the starting point, walk areas until a suitable hole is found */
427
	while (addr + size > first->va_start && addr + size <= vend) {
Nick Piggin's avatar
Nick Piggin committed
428 429
		if (addr + cached_hole_size < first->va_start)
			cached_hole_size = first->va_start - addr;
430
		addr = ALIGN(first->va_end, align);
431
		if (addr + size < addr)
Nick Piggin's avatar
Nick Piggin committed
432 433
			goto overflow;

434
		if (list_is_last(&first->list, &vmap_area_list))
Nick Piggin's avatar
Nick Piggin committed
435
			goto found;
436 437 438

		first = list_entry(first->list.next,
				struct vmap_area, list);
Nick Piggin's avatar
Nick Piggin committed
439 440
	}

Nick Piggin's avatar
Nick Piggin committed
441 442 443
found:
	if (addr + size > vend)
		goto overflow;
Nick Piggin's avatar
Nick Piggin committed
444 445 446 447 448

	va->va_start = addr;
	va->va_end = addr + size;
	va->flags = 0;
	__insert_vmap_area(va);
Nick Piggin's avatar
Nick Piggin committed
449
	free_vmap_cache = &va->rb_node;
Nick Piggin's avatar
Nick Piggin committed
450 451
	spin_unlock(&vmap_area_lock);

Nick Piggin's avatar
Nick Piggin committed
452 453 454 455
	BUG_ON(va->va_start & (align-1));
	BUG_ON(va->va_start < vstart);
	BUG_ON(va->va_end > vend);

Nick Piggin's avatar
Nick Piggin committed
456
	return va;
Nick Piggin's avatar
Nick Piggin committed
457 458 459 460 461 462 463 464 465 466 467 468 469 470

overflow:
	spin_unlock(&vmap_area_lock);
	if (!purged) {
		purge_vmap_area_lazy();
		purged = 1;
		goto retry;
	}
	if (printk_ratelimit())
		printk(KERN_WARNING
			"vmap allocation for size %lu failed: "
			"use vmalloc=<size> to increase size.\n", size);
	kfree(va);
	return ERR_PTR(-EBUSY);
Nick Piggin's avatar
Nick Piggin committed
471 472 473 474 475
}

static void __free_vmap_area(struct vmap_area *va)
{
	BUG_ON(RB_EMPTY_NODE(&va->rb_node));
Nick Piggin's avatar
Nick Piggin committed
476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491

	if (free_vmap_cache) {
		if (va->va_end < cached_vstart) {
			free_vmap_cache = NULL;
		} else {
			struct vmap_area *cache;
			cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node);
			if (va->va_start <= cache->va_start) {
				free_vmap_cache = rb_prev(&va->rb_node);
				/*
				 * We don't try to update cached_hole_size or
				 * cached_align, but it won't go very wrong.
				 */
			}
		}
	}
Nick Piggin's avatar
Nick Piggin committed
492 493 494 495
	rb_erase(&va->rb_node, &vmap_area_root);
	RB_CLEAR_NODE(&va->rb_node);
	list_del_rcu(&va->list);

496 497 498 499 500 501 502 503 504
	/*
	 * Track the highest possible candidate for pcpu area
	 * allocation.  Areas outside of vmalloc area can be returned
	 * here too, consider only end addresses which fall inside
	 * vmalloc area proper.
	 */
	if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END)
		vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end);

505
	kfree_rcu(va, rcu_head);
Nick Piggin's avatar
Nick Piggin committed
506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525
}

/*
 * Free a region of KVA allocated by alloc_vmap_area
 */
static void free_vmap_area(struct vmap_area *va)
{
	spin_lock(&vmap_area_lock);
	__free_vmap_area(va);
	spin_unlock(&vmap_area_lock);
}

/*
 * Clear the pagetable entries of a given vmap_area
 */
static void unmap_vmap_area(struct vmap_area *va)
{
	vunmap_page_range(va->va_start, va->va_end);
}

526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546
static void vmap_debug_free_range(unsigned long start, unsigned long end)
{
	/*
	 * Unmap page tables and force a TLB flush immediately if
	 * CONFIG_DEBUG_PAGEALLOC is set. This catches use after free
	 * bugs similarly to those in linear kernel virtual address
	 * space after a page has been freed.
	 *
	 * All the lazy freeing logic is still retained, in order to
	 * minimise intrusiveness of this debugging feature.
	 *
	 * This is going to be *slow* (linear kernel virtual address
	 * debugging doesn't do a broadcast TLB flush so it is a lot
	 * faster).
	 */
#ifdef CONFIG_DEBUG_PAGEALLOC
	vunmap_page_range(start, end);
	flush_tlb_kernel_range(start, end);
#endif
}

Nick Piggin's avatar
Nick Piggin committed
547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573
/*
 * lazy_max_pages is the maximum amount of virtual address space we gather up
 * before attempting to purge with a TLB flush.
 *
 * There is a tradeoff here: a larger number will cover more kernel page tables
 * and take slightly longer to purge, but it will linearly reduce the number of
 * global TLB flushes that must be performed. It would seem natural to scale
 * this number up linearly with the number of CPUs (because vmapping activity
 * could also scale linearly with the number of CPUs), however it is likely
 * that in practice, workloads might be constrained in other ways that mean
 * vmap activity will not scale linearly with CPUs. Also, I want to be
 * conservative and not introduce a big latency on huge systems, so go with
 * a less aggressive log scale. It will still be an improvement over the old
 * code, and it will be simple to change the scale factor if we find that it
 * becomes a problem on bigger systems.
 */
static unsigned long lazy_max_pages(void)
{
	unsigned int log;

	log = fls(num_online_cpus());

	return log * (32UL * 1024 * 1024 / PAGE_SIZE);
}

static atomic_t vmap_lazy_nr = ATOMIC_INIT(0);

574 575 576
/* for per-CPU blocks */
static void purge_fragmented_blocks_allcpus(void);

577 578 579 580 581 582 583 584 585
/*
 * called before a call to iounmap() if the caller wants vm_area_struct's
 * immediately freed.
 */
void set_iounmap_nonlazy(void)
{
	atomic_set(&vmap_lazy_nr, lazy_max_pages()+1);
}

Nick Piggin's avatar
Nick Piggin committed
586 587 588 589 590 591 592 593 594 595 596 597 598
/*
 * Purges all lazily-freed vmap areas.
 *
 * If sync is 0 then don't purge if there is already a purge in progress.
 * If force_flush is 1, then flush kernel TLBs between *start and *end even
 * if we found no lazy vmap areas to unmap (callers can use this to optimise
 * their own TLB flushing).
 * Returns with *start = min(*start, lowest purged address)
 *              *end = max(*end, highest purged address)
 */
static void __purge_vmap_area_lazy(unsigned long *start, unsigned long *end,
					int sync, int force_flush)
{
599
	static DEFINE_SPINLOCK(purge_lock);
Nick Piggin's avatar
Nick Piggin committed
600 601
	LIST_HEAD(valist);
	struct vmap_area *va;
602
	struct vmap_area *n_va;
Nick Piggin's avatar
Nick Piggin committed
603 604 605 606 607 608 609 610
	int nr = 0;

	/*
	 * If sync is 0 but force_flush is 1, we'll go sync anyway but callers
	 * should not expect such behaviour. This just simplifies locking for
	 * the case that isn't actually used at the moment anyway.
	 */
	if (!sync && !force_flush) {
611
		if (!spin_trylock(&purge_lock))
Nick Piggin's avatar
Nick Piggin committed
612 613
			return;
	} else
614
		spin_lock(&purge_lock);
Nick Piggin's avatar
Nick Piggin committed
615

616 617 618
	if (sync)
		purge_fragmented_blocks_allcpus();

Nick Piggin's avatar
Nick Piggin committed
619 620 621 622 623 624 625 626 627 628 629 630 631 632 633
	rcu_read_lock();
	list_for_each_entry_rcu(va, &vmap_area_list, list) {
		if (va->flags & VM_LAZY_FREE) {
			if (va->va_start < *start)
				*start = va->va_start;
			if (va->va_end > *end)
				*end = va->va_end;
			nr += (va->va_end - va->va_start) >> PAGE_SHIFT;
			list_add_tail(&va->purge_list, &valist);
			va->flags |= VM_LAZY_FREEING;
			va->flags &= ~VM_LAZY_FREE;
		}
	}
	rcu_read_unlock();

634
	if (nr)
Nick Piggin's avatar
Nick Piggin committed
635 636 637 638 639 640 641
		atomic_sub(nr, &vmap_lazy_nr);

	if (nr || force_flush)
		flush_tlb_kernel_range(*start, *end);

	if (nr) {
		spin_lock(&vmap_area_lock);
642
		list_for_each_entry_safe(va, n_va, &valist, purge_list)
Nick Piggin's avatar
Nick Piggin committed
643 644 645
			__free_vmap_area(va);
		spin_unlock(&vmap_area_lock);
	}
646
	spin_unlock(&purge_lock);
Nick Piggin's avatar
Nick Piggin committed
647 648
}

Nick Piggin's avatar
Nick Piggin committed
649 650 651 652 653 654 655 656 657 658 659
/*
 * Kick off a purge of the outstanding lazy areas. Don't bother if somebody
 * is already purging.
 */
static void try_purge_vmap_area_lazy(void)
{
	unsigned long start = ULONG_MAX, end = 0;

	__purge_vmap_area_lazy(&start, &end, 0, 0);
}

Nick Piggin's avatar
Nick Piggin committed
660 661 662 663 664 665 666
/*
 * Kick off a purge of the outstanding lazy areas.
 */
static void purge_vmap_area_lazy(void)
{
	unsigned long start = ULONG_MAX, end = 0;

Nick Piggin's avatar
Nick Piggin committed
667
	__purge_vmap_area_lazy(&start, &end, 1, 0);
Nick Piggin's avatar
Nick Piggin committed
668 669 670
}

/*
671 672 673
 * Free a vmap area, caller ensuring that the area has been unmapped
 * and flush_cache_vunmap had been called for the correct range
 * previously.
Nick Piggin's avatar
Nick Piggin committed
674
 */
675
static void free_vmap_area_noflush(struct vmap_area *va)
Nick Piggin's avatar
Nick Piggin committed
676 677 678 679
{
	va->flags |= VM_LAZY_FREE;
	atomic_add((va->va_end - va->va_start) >> PAGE_SHIFT, &vmap_lazy_nr);
	if (unlikely(atomic_read(&vmap_lazy_nr) > lazy_max_pages()))
Nick Piggin's avatar
Nick Piggin committed
680
		try_purge_vmap_area_lazy();
Nick Piggin's avatar
Nick Piggin committed
681 682
}

683 684 685 686 687 688 689 690 691 692
/*
 * Free and unmap a vmap area, caller ensuring flush_cache_vunmap had been
 * called for the correct range previously.
 */
static void free_unmap_vmap_area_noflush(struct vmap_area *va)
{
	unmap_vmap_area(va);
	free_vmap_area_noflush(va);
}

693 694 695 696 697 698 699 700 701
/*
 * Free and unmap a vmap area
 */
static void free_unmap_vmap_area(struct vmap_area *va)
{
	flush_cache_vunmap(va->va_start, va->va_end);
	free_unmap_vmap_area_noflush(va);
}

Nick Piggin's avatar
Nick Piggin committed
702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745
static struct vmap_area *find_vmap_area(unsigned long addr)
{
	struct vmap_area *va;

	spin_lock(&vmap_area_lock);
	va = __find_vmap_area(addr);
	spin_unlock(&vmap_area_lock);

	return va;
}

static void free_unmap_vmap_area_addr(unsigned long addr)
{
	struct vmap_area *va;

	va = find_vmap_area(addr);
	BUG_ON(!va);
	free_unmap_vmap_area(va);
}


/*** Per cpu kva allocator ***/

/*
 * vmap space is limited especially on 32 bit architectures. Ensure there is
 * room for at least 16 percpu vmap blocks per CPU.
 */
/*
 * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
 * to #define VMALLOC_SPACE		(VMALLOC_END-VMALLOC_START). Guess
 * instead (we just need a rough idea)
 */
#if BITS_PER_LONG == 32
#define VMALLOC_SPACE		(128UL*1024*1024)
#else
#define VMALLOC_SPACE		(128UL*1024*1024*1024)
#endif

#define VMALLOC_PAGES		(VMALLOC_SPACE / PAGE_SIZE)
#define VMAP_MAX_ALLOC		BITS_PER_LONG	/* 256K with 4K pages */
#define VMAP_BBMAP_BITS_MAX	1024	/* 4MB with 4K pages */
#define VMAP_BBMAP_BITS_MIN	(VMAP_MAX_ALLOC*2)
#define VMAP_MIN(x, y)		((x) < (y) ? (x) : (y)) /* can't use min() */
#define VMAP_MAX(x, y)		((x) > (y) ? (x) : (y)) /* can't use max() */
746 747 748 749
#define VMAP_BBMAP_BITS		\
		VMAP_MIN(VMAP_BBMAP_BITS_MAX,	\
		VMAP_MAX(VMAP_BBMAP_BITS_MIN,	\
			VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
Nick Piggin's avatar
Nick Piggin committed
750 751 752

#define VMAP_BLOCK_SIZE		(VMAP_BBMAP_BITS * PAGE_SIZE)

753 754
static bool vmap_initialized __read_mostly = false;

Nick Piggin's avatar
Nick Piggin committed
755 756 757 758 759 760 761 762 763 764
struct vmap_block_queue {
	spinlock_t lock;
	struct list_head free;
};

struct vmap_block {
	spinlock_t lock;
	struct vmap_area *va;
	unsigned long free, dirty;
	DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
765 766
	struct list_head free_list;
	struct rcu_head rcu_head;
767
	struct list_head purge;
Nick Piggin's avatar
Nick Piggin committed
768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812
};

/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);

/*
 * Radix tree of vmap blocks, indexed by address, to quickly find a vmap block
 * in the free path. Could get rid of this if we change the API to return a
 * "cookie" from alloc, to be passed to free. But no big deal yet.
 */
static DEFINE_SPINLOCK(vmap_block_tree_lock);
static RADIX_TREE(vmap_block_tree, GFP_ATOMIC);

/*
 * We should probably have a fallback mechanism to allocate virtual memory
 * out of partially filled vmap blocks. However vmap block sizing should be
 * fairly reasonable according to the vmalloc size, so it shouldn't be a
 * big problem.
 */

static unsigned long addr_to_vb_idx(unsigned long addr)
{
	addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
	addr /= VMAP_BLOCK_SIZE;
	return addr;
}

static struct vmap_block *new_vmap_block(gfp_t gfp_mask)
{
	struct vmap_block_queue *vbq;
	struct vmap_block *vb;
	struct vmap_area *va;
	unsigned long vb_idx;
	int node, err;

	node = numa_node_id();

	vb = kmalloc_node(sizeof(struct vmap_block),
			gfp_mask & GFP_RECLAIM_MASK, node);
	if (unlikely(!vb))
		return ERR_PTR(-ENOMEM);

	va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
					VMALLOC_START, VMALLOC_END,
					node, gfp_mask);
813
	if (IS_ERR(va)) {
Nick Piggin's avatar
Nick Piggin committed
814
		kfree(vb);
Julia Lawall's avatar
Julia Lawall committed
815
		return ERR_CAST(va);
Nick Piggin's avatar
Nick Piggin committed
816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840
	}

	err = radix_tree_preload(gfp_mask);
	if (unlikely(err)) {
		kfree(vb);
		free_vmap_area(va);
		return ERR_PTR(err);
	}

	spin_lock_init(&vb->lock);
	vb->va = va;
	vb->free = VMAP_BBMAP_BITS;
	vb->dirty = 0;
	bitmap_zero(vb->dirty_map, VMAP_BBMAP_BITS);
	INIT_LIST_HEAD(&vb->free_list);

	vb_idx = addr_to_vb_idx(va->va_start);
	spin_lock(&vmap_block_tree_lock);
	err = radix_tree_insert(&vmap_block_tree, vb_idx, vb);
	spin_unlock(&vmap_block_tree_lock);
	BUG_ON(err);
	radix_tree_preload_end();

	vbq = &get_cpu_var(vmap_block_queue);
	spin_lock(&vbq->lock);
841
	list_add_rcu(&vb->free_list, &vbq->free);
Nick Piggin's avatar
Nick Piggin committed
842
	spin_unlock(&vbq->lock);
843
	put_cpu_var(vmap_block_queue);
Nick Piggin's avatar
Nick Piggin committed
844 845 846 847 848 849 850 851 852 853 854 855 856 857 858

	return vb;
}

static void free_vmap_block(struct vmap_block *vb)
{
	struct vmap_block *tmp;
	unsigned long vb_idx;

	vb_idx = addr_to_vb_idx(vb->va->va_start);
	spin_lock(&vmap_block_tree_lock);
	tmp = radix_tree_delete(&vmap_block_tree, vb_idx);
	spin_unlock(&vmap_block_tree_lock);
	BUG_ON(tmp != vb);

859
	free_vmap_area_noflush(vb->va);
860
	kfree_rcu(vb, rcu_head);
Nick Piggin's avatar
Nick Piggin committed
861 862
}

863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904
static void purge_fragmented_blocks(int cpu)
{
	LIST_HEAD(purge);
	struct vmap_block *vb;
	struct vmap_block *n_vb;
	struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);

	rcu_read_lock();
	list_for_each_entry_rcu(vb, &vbq->free, free_list) {

		if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS))
			continue;

		spin_lock(&vb->lock);
		if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) {
			vb->free = 0; /* prevent further allocs after releasing lock */
			vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */
			bitmap_fill(vb->dirty_map, VMAP_BBMAP_BITS);
			spin_lock(&vbq->lock);
			list_del_rcu(&vb->free_list);
			spin_unlock(&vbq->lock);
			spin_unlock(&vb->lock);
			list_add_tail(&vb->purge, &purge);
		} else
			spin_unlock(&vb->lock);
	}
	rcu_read_unlock();

	list_for_each_entry_safe(vb, n_vb, &purge, purge) {
		list_del(&vb->purge);
		free_vmap_block(vb);
	}
}

static void purge_fragmented_blocks_allcpus(void)
{
	int cpu;

	for_each_possible_cpu(cpu)
		purge_fragmented_blocks(cpu);
}

Nick Piggin's avatar
Nick Piggin committed
905 906 907 908 909 910 911 912 913
static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
{
	struct vmap_block_queue *vbq;
	struct vmap_block *vb;
	unsigned long addr = 0;
	unsigned int order;

	BUG_ON(size & ~PAGE_MASK);
	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
Jan Kara's avatar
Jan Kara committed
914 915 916 917 918 919 920 921
	if (WARN_ON(size == 0)) {
		/*
		 * Allocating 0 bytes isn't what caller wants since
		 * get_order(0) returns funny result. Just warn and terminate
		 * early.
		 */
		return NULL;
	}
Nick Piggin's avatar
Nick Piggin committed
922 923 924 925 926 927 928 929 930
	order = get_order(size);

again:
	rcu_read_lock();
	vbq = &get_cpu_var(vmap_block_queue);
	list_for_each_entry_rcu(vb, &vbq->free, free_list) {
		int i;

		spin_lock(&vb->lock);
931 932 933
		if (vb->free < 1UL << order)
			goto next;

934
		i = VMAP_BBMAP_BITS - vb->free;
935 936 937 938 939 940 941 942 943 944 945 946
		addr = vb->va->va_start + (i << PAGE_SHIFT);
		BUG_ON(addr_to_vb_idx(addr) !=
				addr_to_vb_idx(vb->va->va_start));
		vb->free -= 1UL << order;
		if (vb->free == 0) {
			spin_lock(&vbq->lock);
			list_del_rcu(&vb->free_list);
			spin_unlock(&vbq->lock);
		}
		spin_unlock(&vb->lock);
		break;
next:
Nick Piggin's avatar
Nick Piggin committed
947 948
		spin_unlock(&vb->lock);
	}
949

950
	put_cpu_var(vmap_block_queue);
Nick Piggin's avatar
Nick Piggin committed
951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971
	rcu_read_unlock();

	if (!addr) {
		vb = new_vmap_block(gfp_mask);
		if (IS_ERR(vb))
			return vb;
		goto again;
	}

	return (void *)addr;
}

static void vb_free(const void *addr, unsigned long size)
{
	unsigned long offset;
	unsigned long vb_idx;
	unsigned int order;
	struct vmap_block *vb;

	BUG_ON(size & ~PAGE_MASK);
	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
972 973 974

	flush_cache_vunmap((unsigned long)addr, (unsigned long)addr + size);

Nick Piggin's avatar
Nick Piggin committed
975 976 977 978 979 980 981 982 983 984
	order = get_order(size);

	offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1);

	vb_idx = addr_to_vb_idx((unsigned long)addr);
	rcu_read_lock();
	vb = radix_tree_lookup(&vmap_block_tree, vb_idx);
	rcu_read_unlock();
	BUG_ON(!vb);

985 986
	vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);

Nick Piggin's avatar
Nick Piggin committed
987
	spin_lock(&vb->lock);
988
	BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
989

Nick Piggin's avatar
Nick Piggin committed
990 991
	vb->dirty += 1UL << order;
	if (vb->dirty == VMAP_BBMAP_BITS) {
992
		BUG_ON(vb->free);
Nick Piggin's avatar
Nick Piggin committed
993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017
		spin_unlock(&vb->lock);
		free_vmap_block(vb);
	} else
		spin_unlock(&vb->lock);
}

/**
 * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
 *
 * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
 * to amortize TLB flushing overheads. What this means is that any page you
 * have now, may, in a former life, have been mapped into kernel virtual
 * address by the vmap layer and so there might be some CPUs with TLB entries
 * still referencing that page (additional to the regular 1:1 kernel mapping).
 *
 * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
 * be sure that none of the pages we have control over will have any aliases
 * from the vmap layer.
 */
void vm_unmap_aliases(void)
{
	unsigned long start = ULONG_MAX, end = 0;
	int cpu;
	int flush = 0;

1018 1019 1020
	if (unlikely(!vmap_initialized))
		return;

Nick Piggin's avatar
Nick Piggin committed
1021 1022 1023 1024 1025 1026
	for_each_possible_cpu(cpu) {
		struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
		struct vmap_block *vb;

		rcu_read_lock();
		list_for_each_entry_rcu(vb, &vbq->free, free_list) {
1027
			int i, j;
Nick Piggin's avatar
Nick Piggin committed
1028 1029 1030

			spin_lock(&vb->lock);
			i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
1031
			if (i < VMAP_BBMAP_BITS) {
Nick Piggin's avatar
Nick Piggin committed
1032
				unsigned long s, e;
1033 1034 1035 1036

				j = find_last_bit(vb->dirty_map,
							VMAP_BBMAP_BITS);
				j = j + 1; /* need exclusive index */
Nick Piggin's avatar
Nick Piggin committed
1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071

				s = vb->va->va_start + (i << PAGE_SHIFT);
				e = vb->va->va_start + (j << PAGE_SHIFT);
				flush = 1;

				if (s < start)
					start = s;
				if (e > end)
					end = e;
			}
			spin_unlock(&vb->lock);
		}
		rcu_read_unlock();
	}

	__purge_vmap_area_lazy(&start, &end, 1, flush);
}
EXPORT_SYMBOL_GPL(vm_unmap_aliases);

/**
 * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
 * @mem: the pointer returned by vm_map_ram
 * @count: the count passed to that vm_map_ram call (cannot unmap partial)
 */
void vm_unmap_ram(const void *mem, unsigned int count)
{
	unsigned long size = count << PAGE_SHIFT;
	unsigned long addr = (unsigned long)mem;

	BUG_ON(!addr);
	BUG_ON(addr < VMALLOC_START);
	BUG_ON(addr > VMALLOC_END);
	BUG_ON(addr & (PAGE_SIZE-1));

	debug_check_no_locks_freed(mem, size);
1072
	vmap_debug_free_range(addr, addr+size);
Nick Piggin's avatar
Nick Piggin committed
1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086

	if (likely(count <= VMAP_MAX_ALLOC))
		vb_free(mem, size);
	else
		free_unmap_vmap_area_addr(addr);
}
EXPORT_SYMBOL(vm_unmap_ram);

/**
 * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
 * @pages: an array of pointers to the pages to be mapped
 * @count: number of pages
 * @node: prefer to allocate data structures on this node
 * @prot: memory protection to use. PAGE_KERNEL for regular RAM
1087
 *
1088 1089 1090 1091 1092 1093
 * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
 * faster than vmap so it's good.  But if you mix long-life and short-life
 * objects with vm_map_ram(), it could consume lots of address space through
 * fragmentation (especially on a 32bit machine).  You could see failures in
 * the end.  Please use this function for short-lived objects.
 *
1094
 * Returns: a pointer to the address that has been mapped, or %NULL on failure
Nick Piggin's avatar
Nick Piggin committed
1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124
 */
void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t prot)
{
	unsigned long size = count << PAGE_SHIFT;
	unsigned long addr;
	void *mem;

	if (likely(count <= VMAP_MAX_ALLOC)) {
		mem = vb_alloc(size, GFP_KERNEL);
		if (IS_ERR(mem))
			return NULL;
		addr = (unsigned long)mem;
	} else {
		struct vmap_area *va;
		va = alloc_vmap_area(size, PAGE_SIZE,
				VMALLOC_START, VMALLOC_END, node, GFP_KERNEL);
		if (IS_ERR(va))
			return NULL;

		addr = va->va_start;
		mem = (void *)addr;
	}
	if (vmap_page_range(addr, addr + size, prot, pages) < 0) {
		vm_unmap_ram(mem, count);
		return NULL;
	}
	return mem;
}
EXPORT_SYMBOL(vm_map_ram);

1125
static struct vm_struct *vmlist __initdata;
Nicolas Pitre's avatar
Nicolas Pitre committed
1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151
/**
 * vm_area_add_early - add vmap area early during boot
 * @vm: vm_struct to add
 *
 * This function is used to add fixed kernel vm area to vmlist before
 * vmalloc_init() is called.  @vm->addr, @vm->size, and @vm->flags
 * should contain proper values and the other fields should be zero.
 *
 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
 */
void __init vm_area_add_early(struct vm_struct *vm)
{
	struct vm_struct *tmp, **p;

	BUG_ON(vmap_initialized);
	for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
		if (tmp->addr >= vm->addr) {
			BUG_ON(tmp->addr < vm->addr + vm->size);
			break;
		} else
			BUG_ON(tmp->addr + tmp->size > vm->addr);
	}
	vm->next = *p;
	*p = vm;
}

1152 1153 1154
/**
 * vm_area_register_early - register vmap area early during boot
 * @vm: vm_struct to register
1155
 * @align: requested alignment
1156 1157 1158 1159 1160 1161 1162 1163
 *
 * This function is used to register kernel vm area before
 * vmalloc_init() is called.  @vm->size and @vm->flags should contain
 * proper values on entry and other fields should be zero.  On return,
 * vm->addr contains the allocated address.
 *
 * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
 */
1164
void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1165 1166
{
	static size_t vm_init_off __initdata;
1167 1168 1169 1170
	unsigned long addr;

	addr = ALIGN(VMALLOC_START + vm_init_off, align);
	vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1171

1172
	vm->addr = (void *)addr;
1173

Nicolas Pitre's avatar
Nicolas Pitre committed
1174
	vm_area_add_early(vm);
1175 1176
}

Nick Piggin's avatar
Nick Piggin committed
1177 1178
void __init vmalloc_init(void)
{
Ivan Kokshaysky's avatar
Ivan Kokshaysky committed
1179 1180
	struct vmap_area *va;
	struct vm_struct *tmp;
Nick Piggin's avatar
Nick Piggin committed
1181 1182 1183 1184
	int i;

	for_each_possible_cpu(i) {
		struct vmap_block_queue *vbq;
1185
		struct vfree_deferred *p;
Nick Piggin's avatar
Nick Piggin committed
1186 1187 1188 1189

		vbq = &per_cpu(vmap_block_queue, i);
		spin_lock_init(&vbq->lock);
		INIT_LIST_HEAD(&vbq->free);
1190 1191 1192
		p = &per_cpu(vfree_deferred, i);
		init_llist_head(&p->list);
		INIT_WORK(&p->wq, free_work);
Nick Piggin's avatar
Nick Piggin committed
1193
	}
1194

Ivan Kokshaysky's avatar
Ivan Kokshaysky committed
1195 1196
	/* Import existing vmlist entries. */
	for (tmp = vmlist; tmp; tmp = tmp->next) {
1197
		va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
1198
		va->flags = VM_VM_AREA;
Ivan Kokshaysky's avatar
Ivan Kokshaysky committed
1199 1200
		va->va_start = (unsigned long)tmp->addr;
		va->va_end = va->va_start + tmp->size;
1201
		va->vm = tmp;
Ivan Kokshaysky's avatar
Ivan Kokshaysky committed
1202 1203
		__insert_vmap_area(va);
	}
1204 1205 1206

	vmap_area_pcpu_hole = VMALLOC_END;

1207
	vmap_initialized = true;
Nick Piggin's avatar
Nick Piggin committed
1208 1209
}

1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252
/**
 * map_kernel_range_noflush - map kernel VM area with the specified pages
 * @addr: start of the VM area to map
 * @size: size of the VM area to map
 * @prot: page protection flags to use
 * @pages: pages to map
 *
 * Map PFN_UP(@size) pages at @addr.  The VM area @addr and @size
 * specify should have been allocated using get_vm_area() and its
 * friends.
 *
 * NOTE:
 * This function does NOT do any cache flushing.  The caller is
 * responsible for calling flush_cache_vmap() on to-be-mapped areas
 * before calling this function.
 *
 * RETURNS:
 * The number of pages mapped on success, -errno on failure.
 */
int map_kernel_range_noflush(unsigned long addr, unsigned long size,
			     pgprot_t prot, struct page **pages)
{
	return vmap_page_range_noflush(addr, addr + size, prot, pages);
}

/**
 * unmap_kernel_range_noflush - unmap kernel VM area
 * @addr: start of the VM area to unmap
 * @size: size of the VM area to unmap
 *
 * Unmap PFN_UP(@size) pages at @addr.  The VM area @addr and @size
 * specify should have been allocated using get_vm_area() and its
 * friends.
 *
 * NOTE:
 * This function does NOT do any cache flushing.  The caller is
 * responsible for calling flush_cache_vunmap() on to-be-mapped areas
 * before calling this function and flush_tlb_kernel_range() after.
 */
void unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
{
	vunmap_page_range(addr, addr + size);
}
1253
EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1254 1255 1256 1257 1258 1259 1260 1261 1262

/**
 * unmap_kernel_range - unmap kernel VM area and flush cache and TLB
 * @addr: start of the VM area to unmap
 * @size: size of the VM area to unmap
 *
 * Similar to unmap_kernel_range_noflush() but flushes vcache before
 * the unmapping and tlb after.
 */
Nick Piggin's avatar
Nick Piggin committed
1263 1264 1265
void unmap_kernel_range(unsigned long addr, unsigned long size)
{
	unsigned long end = addr + size;
1266 1267

	flush_cache_vunmap(addr, end);
Nick Piggin's avatar
Nick Piggin committed
1268 1269 1270
	vunmap_page_range(addr, end);
	flush_tlb_kernel_range(addr, end);
}
1271
EXPORT_SYMBOL_GPL(unmap_kernel_range);
Nick Piggin's avatar
Nick Piggin committed
1272 1273 1274 1275

int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
{
	unsigned long addr = (unsigned long)area->addr;
1276
	unsigned long end = addr + get_vm_area_size(area);
Nick Piggin's avatar
Nick Piggin committed
1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288
	int err;

	err = vmap_page_range(addr, end, prot, *pages);
	if (err > 0) {
		*pages += err;
		err = 0;
	}

	return err;
}
EXPORT_SYMBOL_GPL(map_vm_area);

1289
static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1290
			      unsigned long flags, const void *caller)
1291
{
1292
	spin_lock(&vmap_area_lock);
1293 1294 1295 1296
	vm->flags = flags;
	vm->addr = (void *)va->va_start;
	vm->size = va->va_end - va->va_start;
	vm->caller = caller;
1297
	va->vm = vm;
1298
	va->flags |= VM_VM_AREA;
1299
	spin_unlock(&vmap_area_lock);
1300
}
1301

1302
static void clear_vm_uninitialized_flag(struct vm_struct *vm)
1303
{
1304
	/*
1305
	 * Before removing VM_UNINITIALIZED,
1306 1307 1308 1309
	 * we should make sure that vm has proper values.
	 * Pair with smp_rmb() in show_numa_info().
	 */
	smp_wmb();
1310
	vm->flags &= ~VM_UNINITIALIZED;
1311 1312
}

Nick Piggin's avatar
Nick Piggin committed
1313
static struct vm_struct *__get_vm_area_node(unsigned long size,
1314
		unsigned long align, unsigned long flags, unsigned long start,
1315
		unsigned long end, int node, gfp_t gfp_mask, const void *caller)
Nick Piggin's avatar
Nick Piggin committed
1316
{
1317
	struct vmap_area *va;
Nick Piggin's avatar
Nick Piggin committed
1318
	struct vm_struct *area;
Linus Torvalds's avatar
Linus Torvalds committed
1319