vmalloc.c 64.2 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>
Nick Piggin's avatar
Nick Piggin committed
29
#include <asm/atomic.h>
Linus Torvalds's avatar
Linus Torvalds committed
30 31
#include <asm/uaccess.h>
#include <asm/tlbflush.h>
32
#include <asm/shmparam.h>
Linus Torvalds's avatar
Linus Torvalds committed
33

Nick Piggin's avatar
Nick Piggin committed
34
/*** Page table manipulation functions ***/
35

Linus Torvalds's avatar
Linus Torvalds committed
36 37 38 39 40 41 42 43 44 45 46
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
47
static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
Linus Torvalds's avatar
Linus Torvalds committed
48 49 50 51 52 53 54 55 56 57 58 59 60
{
	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
61
static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
Linus Torvalds's avatar
Linus Torvalds committed
62 63 64 65 66 67 68 69 70 71 72 73 74
{
	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
75
static void vunmap_page_range(unsigned long addr, unsigned long end)
Linus Torvalds's avatar
Linus Torvalds committed
76 77 78 79 80 81 82 83 84 85 86 87 88 89 90
{
	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
91
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
Linus Torvalds's avatar
Linus Torvalds committed
92 93 94
{
	pte_t *pte;

Nick Piggin's avatar
Nick Piggin committed
95 96 97 98 99
	/*
	 * nr is a running index into the array which helps higher level
	 * callers keep track of where we're up to.
	 */

100
	pte = pte_alloc_kernel(pmd, addr);
Linus Torvalds's avatar
Linus Torvalds committed
101 102 103
	if (!pte)
		return -ENOMEM;
	do {
Nick Piggin's avatar
Nick Piggin committed
104 105 106 107 108
		struct page *page = pages[*nr];

		if (WARN_ON(!pte_none(*pte)))
			return -EBUSY;
		if (WARN_ON(!page))
Linus Torvalds's avatar
Linus Torvalds committed
109 110
			return -ENOMEM;
		set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
Nick Piggin's avatar
Nick Piggin committed
111
		(*nr)++;
Linus Torvalds's avatar
Linus Torvalds committed
112 113 114 115
	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
116 117
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
118 119 120 121 122 123 124 125 126
{
	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
127
		if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
Linus Torvalds's avatar
Linus Torvalds committed
128 129 130 131 132
			return -ENOMEM;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
133 134
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
135 136 137 138 139 140 141 142 143
{
	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
144
		if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
Linus Torvalds's avatar
Linus Torvalds committed
145 146 147 148 149
			return -ENOMEM;
	} while (pud++, addr = next, addr != end);
	return 0;
}

Nick Piggin's avatar
Nick Piggin committed
150 151 152 153 154 155
/*
 * 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]
 */
156 157
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
158 159 160
{
	pgd_t *pgd;
	unsigned long next;
161
	unsigned long addr = start;
Nick Piggin's avatar
Nick Piggin committed
162 163
	int err = 0;
	int nr = 0;
Linus Torvalds's avatar
Linus Torvalds committed
164 165 166 167 168

	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
Nick Piggin's avatar
Nick Piggin committed
169
		err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
Linus Torvalds's avatar
Linus Torvalds committed
170
		if (err)
171
			return err;
Linus Torvalds's avatar
Linus Torvalds committed
172
	} while (pgd++, addr = next, addr != end);
Nick Piggin's avatar
Nick Piggin committed
173 174

	return nr;
Linus Torvalds's avatar
Linus Torvalds committed
175 176
}

177 178 179 180 181 182 183 184 185 186
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;
}

187
int is_vmalloc_or_module_addr(const void *x)
188 189
{
	/*
190
	 * ARM, x86-64 and sparc64 put modules in a special place,
191 192 193 194 195 196 197 198 199 200 201
	 * 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);
}

202
/*
Nick Piggin's avatar
Nick Piggin committed
203
 * Walk a vmap address to the struct page it maps.
204
 */
205
struct page *vmalloc_to_page(const void *vmalloc_addr)
206 207 208 209 210
{
	unsigned long addr = (unsigned long) vmalloc_addr;
	struct page *page = NULL;
	pgd_t *pgd = pgd_offset_k(addr);

211 212 213 214
	/*
	 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
	 * architectures that do not vmalloc module space
	 */
215
	VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
Jiri Slaby's avatar
Jiri Slaby committed
216

217
	if (!pgd_none(*pgd)) {
Nick Piggin's avatar
Nick Piggin committed
218
		pud_t *pud = pud_offset(pgd, addr);
219
		if (!pud_none(*pud)) {
Nick Piggin's avatar
Nick Piggin committed
220
			pmd_t *pmd = pmd_offset(pud, addr);
221
			if (!pmd_none(*pmd)) {
Nick Piggin's avatar
Nick Piggin committed
222 223
				pte_t *ptep, pte;

224 225 226 227 228 229 230 231 232 233 234 235 236 237 238
				ptep = pte_offset_map(pmd, addr);
				pte = *ptep;
				if (pte_present(pte))
					page = pte_page(pte);
				pte_unmap(ptep);
			}
		}
	}
	return page;
}
EXPORT_SYMBOL(vmalloc_to_page);

/*
 * Map a vmalloc()-space virtual address to the physical page frame number.
 */
239
unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
240 241 242 243 244
{
	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
}
EXPORT_SYMBOL(vmalloc_to_pfn);

Nick Piggin's avatar
Nick Piggin committed
245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264

/*** Global kva allocator ***/

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

struct vmap_area {
	unsigned long va_start;
	unsigned long va_end;
	unsigned long flags;
	struct rb_node rb_node;		/* address sorted rbtree */
	struct list_head list;		/* address sorted list */
	struct list_head purge_list;	/* "lazy purge" list */
	void *private;
	struct rcu_head rcu_head;
};

static DEFINE_SPINLOCK(vmap_area_lock);
static LIST_HEAD(vmap_area_list);
Nick Piggin's avatar
Nick Piggin committed
265 266 267 268 269 270 271 272
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;

273
static unsigned long vmap_area_pcpu_hole;
Nick Piggin's avatar
Nick Piggin committed
274 275

static struct vmap_area *__find_vmap_area(unsigned long addr)
Linus Torvalds's avatar
Linus Torvalds committed
276
{
Nick Piggin's avatar
Nick Piggin committed
277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300
	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;
		else if (addr > va->va_start)
			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) {
301
		struct vmap_area *tmp_va;
Nick Piggin's avatar
Nick Piggin committed
302 303

		parent = *p;
304 305
		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
306
			p = &(*p)->rb_left;
307
		else if (va->va_end > tmp_va->va_start)
Nick Piggin's avatar
Nick Piggin committed
308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338
			p = &(*p)->rb_right;
		else
			BUG();
	}

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

	/* address-sort this list so it is usable like the vmlist */
	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
339
	unsigned long addr;
Nick Piggin's avatar
Nick Piggin committed
340
	int purged = 0;
Nick Piggin's avatar
Nick Piggin committed
341
	struct vmap_area *first;
Nick Piggin's avatar
Nick Piggin committed
342

Nick Piggin's avatar
Nick Piggin committed
343
	BUG_ON(!size);
Nick Piggin's avatar
Nick Piggin committed
344
	BUG_ON(size & ~PAGE_MASK);
Nick Piggin's avatar
Nick Piggin committed
345
	BUG_ON(!is_power_of_2(align));
Nick Piggin's avatar
Nick Piggin committed
346 347 348 349 350 351 352 353

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

retry:
	spin_lock(&vmap_area_lock);
Nick Piggin's avatar
Nick Piggin committed
354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392
	/*
	 * 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);
		addr = ALIGN(first->va_end + PAGE_SIZE, align);
		if (addr < vstart)
			goto nocache;
		if (addr + size - 1 < addr)
			goto overflow;

	} else {
		addr = ALIGN(vstart, align);
		if (addr + size - 1 < addr)
			goto overflow;

		n = vmap_area_root.rb_node;
		first = NULL;

		while (n) {
Nick Piggin's avatar
Nick Piggin committed
393 394 395 396
			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
397 398 399 400
				if (tmp->va_start <= addr)
					break;
				n = n->rb_left;
			} else
Nick Piggin's avatar
Nick Piggin committed
401
				n = n->rb_right;
Nick Piggin's avatar
Nick Piggin committed
402
		}
Nick Piggin's avatar
Nick Piggin committed
403 404 405 406

		if (!first)
			goto found;
	}
Nick Piggin's avatar
Nick Piggin committed
407 408 409 410 411 412 413 414 415 416 417 418 419 420

	/* from the starting point, walk areas until a suitable hole is found */
	while (addr + size >= first->va_start && addr + size <= vend) {
		if (addr + cached_hole_size < first->va_start)
			cached_hole_size = first->va_start - addr;
		addr = ALIGN(first->va_end + PAGE_SIZE, align);
		if (addr + size - 1 < addr)
			goto overflow;

		n = rb_next(&first->rb_node);
		if (n)
			first = rb_entry(n, struct vmap_area, rb_node);
		else
			goto found;
Nick Piggin's avatar
Nick Piggin committed
421 422
	}

Nick Piggin's avatar
Nick Piggin committed
423 424 425
found:
	if (addr + size > vend)
		goto overflow;
Nick Piggin's avatar
Nick Piggin committed
426 427 428 429 430

	va->va_start = addr;
	va->va_end = addr + size;
	va->flags = 0;
	__insert_vmap_area(va);
Nick Piggin's avatar
Nick Piggin committed
431
	free_vmap_cache = &va->rb_node;
Nick Piggin's avatar
Nick Piggin committed
432 433
	spin_unlock(&vmap_area_lock);

Nick Piggin's avatar
Nick Piggin committed
434 435 436 437
	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
438
	return va;
Nick Piggin's avatar
Nick Piggin committed
439 440 441 442 443 444 445 446 447 448 449 450 451 452

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
453 454 455 456 457 458 459 460 461 462 463 464
}

static void rcu_free_va(struct rcu_head *head)
{
	struct vmap_area *va = container_of(head, struct vmap_area, rcu_head);

	kfree(va);
}

static void __free_vmap_area(struct vmap_area *va)
{
	BUG_ON(RB_EMPTY_NODE(&va->rb_node));
Nick Piggin's avatar
Nick Piggin committed
465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480

	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
481 482 483 484
	rb_erase(&va->rb_node, &vmap_area_root);
	RB_CLEAR_NODE(&va->rb_node);
	list_del_rcu(&va->list);

485 486 487 488 489 490 491 492 493
	/*
	 * 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);

Nick Piggin's avatar
Nick Piggin committed
494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514
	call_rcu(&va->rcu_head, rcu_free_va);
}

/*
 * 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);
}

515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535
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
536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562
/*
 * 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);

563 564 565
/* for per-CPU blocks */
static void purge_fragmented_blocks_allcpus(void);

566 567 568 569 570 571 572 573 574
/*
 * 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
575 576 577 578 579 580 581 582 583 584 585 586 587
/*
 * 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)
{
588
	static DEFINE_SPINLOCK(purge_lock);
Nick Piggin's avatar
Nick Piggin committed
589 590
	LIST_HEAD(valist);
	struct vmap_area *va;
591
	struct vmap_area *n_va;
Nick Piggin's avatar
Nick Piggin committed
592 593 594 595 596 597 598 599
	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) {
600
		if (!spin_trylock(&purge_lock))
Nick Piggin's avatar
Nick Piggin committed
601 602
			return;
	} else
603
		spin_lock(&purge_lock);
Nick Piggin's avatar
Nick Piggin committed
604

605 606 607
	if (sync)
		purge_fragmented_blocks_allcpus();

Nick Piggin's avatar
Nick Piggin committed
608 609 610 611 612 613 614 615 616 617 618 619 620 621 622
	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();

623
	if (nr)
Nick Piggin's avatar
Nick Piggin committed
624 625 626 627 628 629 630
		atomic_sub(nr, &vmap_lazy_nr);

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

	if (nr) {
		spin_lock(&vmap_area_lock);
631
		list_for_each_entry_safe(va, n_va, &valist, purge_list)
Nick Piggin's avatar
Nick Piggin committed
632 633 634
			__free_vmap_area(va);
		spin_unlock(&vmap_area_lock);
	}
635
	spin_unlock(&purge_lock);
Nick Piggin's avatar
Nick Piggin committed
636 637
}

Nick Piggin's avatar
Nick Piggin committed
638 639 640 641 642 643 644 645 646 647 648
/*
 * 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
649 650 651 652 653 654 655
/*
 * 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
656
	__purge_vmap_area_lazy(&start, &end, 1, 0);
Nick Piggin's avatar
Nick Piggin committed
657 658 659
}

/*
660 661 662
 * 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
663
 */
664
static void free_vmap_area_noflush(struct vmap_area *va)
Nick Piggin's avatar
Nick Piggin committed
665 666 667 668
{
	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
669
		try_purge_vmap_area_lazy();
Nick Piggin's avatar
Nick Piggin committed
670 671
}

672 673 674 675 676 677 678 679 680 681
/*
 * 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);
}

682 683 684 685 686 687 688 689 690
/*
 * 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
691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740
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() */
#define VMAP_BBMAP_BITS		VMAP_MIN(VMAP_BBMAP_BITS_MAX,		\
					VMAP_MAX(VMAP_BBMAP_BITS_MIN,	\
						VMALLOC_PAGES / NR_CPUS / 16))

#define VMAP_BLOCK_SIZE		(VMAP_BBMAP_BITS * PAGE_SIZE)

741 742
static bool vmap_initialized __read_mostly = false;

Nick Piggin's avatar
Nick Piggin committed
743 744 745 746 747 748 749 750 751 752 753 754
struct vmap_block_queue {
	spinlock_t lock;
	struct list_head free;
};

struct vmap_block {
	spinlock_t lock;
	struct vmap_area *va;
	struct vmap_block_queue *vbq;
	unsigned long free, dirty;
	DECLARE_BITMAP(alloc_map, VMAP_BBMAP_BITS);
	DECLARE_BITMAP(dirty_map, VMAP_BBMAP_BITS);
755 756
	struct list_head free_list;
	struct rcu_head rcu_head;
757
	struct list_head purge;
Nick Piggin's avatar
Nick Piggin committed
758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802
};

/* 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);
803
	if (IS_ERR(va)) {
Nick Piggin's avatar
Nick Piggin committed
804
		kfree(vb);
Julia Lawall's avatar
Julia Lawall committed
805
		return ERR_CAST(va);
Nick Piggin's avatar
Nick Piggin committed
806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832
	}

	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->alloc_map, VMAP_BBMAP_BITS);
	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);
	vb->vbq = vbq;
	spin_lock(&vbq->lock);
833
	list_add_rcu(&vb->free_list, &vbq->free);
Nick Piggin's avatar
Nick Piggin committed
834
	spin_unlock(&vbq->lock);
835
	put_cpu_var(vmap_block_queue);
Nick Piggin's avatar
Nick Piggin committed
836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857

	return vb;
}

static void rcu_free_vb(struct rcu_head *head)
{
	struct vmap_block *vb = container_of(head, struct vmap_block, rcu_head);

	kfree(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);

858
	free_vmap_area_noflush(vb->va);
Nick Piggin's avatar
Nick Piggin committed
859 860 861
	call_rcu(&vb->rcu_head, rcu_free_vb);
}

862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909
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->alloc_map, VMAP_BBMAP_BITS);
			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_thiscpu(void)
{
	purge_fragmented_blocks(smp_processor_id());
}

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
910 911 912 913 914 915
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;
916
	int purge = 0;
Nick Piggin's avatar
Nick Piggin committed
917 918 919 920 921 922 923 924 925 926 927 928

	BUG_ON(size & ~PAGE_MASK);
	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
	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);
929 930 931
		if (vb->free < 1UL << order)
			goto next;

Nick Piggin's avatar
Nick Piggin committed
932 933 934
		i = bitmap_find_free_region(vb->alloc_map,
						VMAP_BBMAP_BITS, order);

935 936 937 938 939
		if (i < 0) {
			if (vb->free + vb->dirty == VMAP_BBMAP_BITS) {
				/* fragmented and no outstanding allocations */
				BUG_ON(vb->dirty != VMAP_BBMAP_BITS);
				purge = 1;
Nick Piggin's avatar
Nick Piggin committed
940
			}
941
			goto next;
Nick Piggin's avatar
Nick Piggin committed
942
		}
943 944 945 946 947 948 949 950 951 952 953 954
		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
955 956
		spin_unlock(&vb->lock);
	}
957 958 959 960

	if (purge)
		purge_fragmented_blocks_thiscpu();

961
	put_cpu_var(vmap_block_queue);
Nick Piggin's avatar
Nick Piggin committed
962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982
	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);
983 984 985

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

Nick Piggin's avatar
Nick Piggin committed
986 987 988 989 990 991 992 993 994 995
	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);

996 997
	vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);

Nick Piggin's avatar
Nick Piggin committed
998
	spin_lock(&vb->lock);
999
	BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
1000

Nick Piggin's avatar
Nick Piggin committed
1001 1002
	vb->dirty += 1UL << order;
	if (vb->dirty == VMAP_BBMAP_BITS) {
1003
		BUG_ON(vb->free);
Nick Piggin's avatar
Nick Piggin committed
1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028
		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;

1029 1030 1031
	if (unlikely(!vmap_initialized))
		return;

Nick Piggin's avatar
Nick Piggin committed
1032 1033 1034 1035 1036 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 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085
	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) {
			int i;

			spin_lock(&vb->lock);
			i = find_first_bit(vb->dirty_map, VMAP_BBMAP_BITS);
			while (i < VMAP_BBMAP_BITS) {
				unsigned long s, e;
				int j;
				j = find_next_zero_bit(vb->dirty_map,
					VMAP_BBMAP_BITS, i);

				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;

				i = j;
				i = find_next_bit(vb->dirty_map,
							VMAP_BBMAP_BITS, i);
			}
			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);
1086
	vmap_debug_free_range(addr, addr+size);
Nick Piggin's avatar
Nick Piggin committed
1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100

	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
1101 1102
 *
 * Returns: a pointer to the address that has been mapped, or %NULL on failure
Nick Piggin's avatar
Nick Piggin committed
1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132
 */
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);

1133 1134 1135
/**
 * vm_area_register_early - register vmap area early during boot
 * @vm: vm_struct to register
1136
 * @align: requested alignment
1137 1138 1139 1140 1141 1142 1143 1144
 *
 * 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.
 */
1145
void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1146 1147
{
	static size_t vm_init_off __initdata;
1148 1149 1150 1151
	unsigned long addr;

	addr = ALIGN(VMALLOC_START + vm_init_off, align);
	vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1152

1153
	vm->addr = (void *)addr;
1154 1155 1156 1157 1158

	vm->next = vmlist;
	vmlist = vm;
}

Nick Piggin's avatar
Nick Piggin committed
1159 1160
void __init vmalloc_init(void)
{
Ivan Kokshaysky's avatar
Ivan Kokshaysky committed
1161 1162
	struct vmap_area *va;
	struct vm_struct *tmp;
Nick Piggin's avatar
Nick Piggin committed
1163 1164 1165 1166 1167 1168 1169 1170 1171
	int i;

	for_each_possible_cpu(i) {
		struct vmap_block_queue *vbq;

		vbq = &per_cpu(vmap_block_queue, i);
		spin_lock_init(&vbq->lock);
		INIT_LIST_HEAD(&vbq->free);
	}
1172

Ivan Kokshaysky's avatar
Ivan Kokshaysky committed
1173 1174
	/* Import existing vmlist entries. */
	for (tmp = vmlist; tmp; tmp = tmp->next) {
1175
		va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
Ivan Kokshaysky's avatar
Ivan Kokshaysky committed
1176 1177 1178 1179 1180
		va->flags = tmp->flags | VM_VM_AREA;
		va->va_start = (unsigned long)tmp->addr;
		va->va_end = va->va_start + tmp->size;
		__insert_vmap_area(va);
	}
1181 1182 1183

	vmap_area_pcpu_hole = VMALLOC_END;

1184
	vmap_initialized = true;
Nick Piggin's avatar
Nick Piggin committed
1185 1186
}

1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229
/**
 * 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);
}
1230
EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1231 1232 1233 1234 1235 1236 1237 1238 1239

/**
 * 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
1240 1241 1242
void unmap_kernel_range(unsigned long addr, unsigned long size)
{
	unsigned long end = addr + size;
1243 1244

	flush_cache_vunmap(addr, end);
Nick Piggin's avatar
Nick Piggin committed
1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268
	vunmap_page_range(addr, end);
	flush_tlb_kernel_range(addr, end);
}

int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
{
	unsigned long addr = (unsigned long)area->addr;
	unsigned long end = addr + area->size - PAGE_SIZE;
	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);

/*** Old vmalloc interfaces ***/
DEFINE_RWLOCK(vmlist_lock);
struct vm_struct *vmlist;

1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290
static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
			      unsigned long flags, void *caller)
{
	struct vm_struct *tmp, **p;

	vm->flags = flags;
	vm->addr = (void *)va->va_start;
	vm->size = va->va_end - va->va_start;
	vm->caller = caller;
	va->private = vm;
	va->flags |= VM_VM_AREA;

	write_lock(&vmlist_lock);
	for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
		if (tmp->addr >= vm->addr)
			break;
	}
	vm->next = *p;
	*p = vm;
	write_unlock(&vmlist_lock);
}

Nick Piggin's avatar
Nick Piggin committed
1291
static struct vm_struct *__get_vm_area_node(unsigned long size,
1292 1293
		unsigned long align, unsigned long flags, unsigned long start,
		unsigned long end, int node, gfp_t gfp_mask, void *caller)
Nick Piggin's avatar
Nick Piggin committed
1294 1295 1296
{
	static struct vmap_area *va;
	struct vm_struct *area;
Linus Torvalds's avatar
Linus Torvalds committed
1297

1298
	BUG_ON(in_interrupt());
Linus Torvalds's avatar
Linus Torvalds committed
1299 1300 1301 1302 1303 1304 1305 1306 1307 1308
	if (flags & VM_IOREMAP) {
		int bit = fls(size);

		if (bit > IOREMAP_MAX_ORDER)
			bit = IOREMAP_MAX_ORDER;
		else if (bit < PAGE_SHIFT)
			bit = PAGE_SHIFT;

		align = 1ul << bit;
	}
Nick Piggin's avatar
Nick Piggin committed
1309

Linus Torvalds's avatar
Linus Torvalds committed
1310
	size = PAGE_ALIGN(size);
1311 1312
	if (unlikely(!size))
		return NULL;
Linus Torvalds's avatar
Linus Torvalds committed
1313

1314
	area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
Linus Torvalds's avatar
Linus Torvalds committed
1315 1316 1317 1318 1319 1320 1321 1322
	if (unlikely(!area))
		return NULL;

	/*
	 * We always allocate a guard page.
	 */
	size += PAGE_SIZE;

Nick Piggin's avatar
Nick Piggin committed
1323 1324 1325 1326
	va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
	if (IS_ERR(va)) {
		kfree(area);
		return NULL;
Linus Torvalds's avatar
Linus Torvalds committed
1327 1328
	}

1329
	insert_vmalloc_vm(area, va, flags, caller);
Linus Torvalds's avatar
Linus Torvalds committed
1330 1331 1332
	return area;
}

Christoph Lameter's avatar
Christoph Lameter committed
1333 1334 1335
struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
				unsigned long start, unsigned long end)
{
1336
	return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1337
						__builtin_return_address(0));
Christoph Lameter's avatar
Christoph Lameter committed
1338
}
1339
EXPORT_SYMBOL_GPL(__get_vm_area);
Christoph Lameter's avatar
Christoph Lameter committed
1340

1341 1342 1343 1344
struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
				       unsigned long start, unsigned long end,
				       void *caller)
{
1345
	return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1346 1347 1348
				  caller);
}

Linus Torvalds's avatar
Linus Torvalds committed
1349
/**
Simon Arlott's avatar
Simon Arlott committed
1350
 *	get_vm_area  -  reserve a contiguous kernel virtual area
Linus Torvalds's avatar
Linus Torvalds committed
1351 1352 1353 1354 1355 1356 1357 1358 1359
 *	@size:		size of the area
 *	@flags:		%VM_IOREMAP for I/O mappings or VM_ALLOC
 *
 *	Search an area of @size in the kernel virtual mapping area,
 *	and reserved it for out purposes.  Returns the area descriptor
 *	on success or %NULL on failure.
 */
struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
{
1360
	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1361 1362 1363 1364 1365 1366
				-1, GFP_KERNEL, __builtin_return_address(0));
}

struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
				void *caller)
{
1367
	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1368
						-1, GFP_KERNEL, caller);
Linus Torvalds's avatar
Linus Torvalds committed
1369 1370
}

Nick Piggin's avatar
Nick Piggin committed
1371
static struct vm_struct *find_vm_area(const void *addr)
1372
{
Nick Piggin's avatar
Nick Piggin committed
1373
	struct vmap_area *va;
1374

Nick Piggin's avatar
Nick Piggin committed
1375 1376 1377
	va = find_vmap_area((unsigned long)addr);
	if (va && va->flags & VM_VM_AREA)
		return va->private;
Linus Torvalds's avatar
Linus Torvalds committed
1378 1379 1380 1381

	return NULL;
}

1382
/**
Simon Arlott's avatar
Simon Arlott committed
1383
 *	remove_vm_area  -  find and remove a continuous kernel virtual area
1384 1385 1386 1387 1388 1389
 *	@addr:		base address
 *
 *	Search for the kernel VM area starting at @addr, and remove it.
 *	This function returns the found VM area, but using it is NOT safe
 *	on SMP machines, except for its size or flags.
 */
1390
struct vm_struct *remove_vm_area(const void *addr)
1391
{
Nick Piggin's avatar
Nick Piggin committed
1392 1393 1394 1395 1396 1397
	struct vmap_area *va;

	va = find_vmap_area((unsigned long)addr);
	if (va && va->flags & VM_VM_AREA) {
		struct vm_struct *vm = va->private;
		struct vm_struct *tmp, **p;
1398 1399 1400 1401 1402
		/*
		 * remove from list and disallow access to this vm_struct
		 * before unmap. (address range confliction is maintained by
		 * vmap.)
		 */
Nick Piggin's avatar
Nick Piggin committed
1403 1404 1405 1406 1407 1408
		write_lock(&vmlist_lock);
		for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
			;
		*p = tmp->next;
		write_unlock(&vmlist_lock);

1409 1410 1411 1412
		vmap_debug_free_range(va->va_start, va->va_end);
		free_unmap_vmap_area(va);
		vm->size -= PAGE_SIZE;

Nick Piggin's avatar
Nick Piggin committed
1413 1414 1415
		return vm;
	}
	return NULL;
1416 1417
}

1418
static void __vunmap(const void *addr, int deallocate_pages)
Linus Torvalds's avatar
Linus Torvalds committed
1419 1420 1421 1422 1423 1424 1425
{
	struct vm_struct *area;

	if (!addr)
		return;

	if ((PAGE_SIZE-1) & (unsigned long)addr) {
Arjan van de Ven's avatar
Arjan van de Ven committed
1426
		WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
Linus Torvalds's avatar
Linus Torvalds committed
1427 1428 1429 1430 1431
		return;
	}

	area = remove_vm_area(addr);
	if (unlikely(!area)) {
Arjan van de Ven's avatar
Arjan van de Ven committed
1432
		WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
Linus Torvalds's avatar
Linus Torvalds committed
1433 1434 1435 1436
				addr);
		return;
	}

1437
	debug_check_no_locks_freed(addr, area->size);