vmalloc.c 65.2 KB
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/*
 *  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
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 *  Numa awareness, Christoph Lameter, SGI, June 2005
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 */

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#include <linux/vmalloc.h>
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#include <linux/mm.h>
#include <linux/module.h>
#include <linux/highmem.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
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#include <linux/proc_fs.h>
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#include <linux/seq_file.h>
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#include <linux/debugobjects.h>
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#include <linux/kallsyms.h>
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#include <linux/list.h>
#include <linux/rbtree.h>
#include <linux/radix-tree.h>
#include <linux/rcupdate.h>
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#include <linux/pfn.h>
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#include <linux/kmemleak.h>
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#include <linux/atomic.h>
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#include <asm/uaccess.h>
#include <asm/tlbflush.h>
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#include <asm/shmparam.h>
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/*** Page table manipulation functions ***/
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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);
}

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static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end)
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{
	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);
}

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static void vunmap_pud_range(pgd_t *pgd, unsigned long addr, unsigned long end)
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{
	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);
}

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static void vunmap_page_range(unsigned long addr, unsigned long end)
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{
	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,
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		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
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{
	pte_t *pte;

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	/*
	 * nr is a running index into the array which helps higher level
	 * callers keep track of where we're up to.
	 */

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	pte = pte_alloc_kernel(pmd, addr);
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	if (!pte)
		return -ENOMEM;
	do {
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		struct page *page = pages[*nr];

		if (WARN_ON(!pte_none(*pte)))
			return -EBUSY;
		if (WARN_ON(!page))
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			return -ENOMEM;
		set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
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		(*nr)++;
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	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}

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static int vmap_pmd_range(pud_t *pud, unsigned long addr,
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
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{
	pmd_t *pmd;
	unsigned long next;

	pmd = pmd_alloc(&init_mm, pud, addr);
	if (!pmd)
		return -ENOMEM;
	do {
		next = pmd_addr_end(addr, end);
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		if (vmap_pte_range(pmd, addr, next, prot, pages, nr))
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			return -ENOMEM;
	} while (pmd++, addr = next, addr != end);
	return 0;
}

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static int vmap_pud_range(pgd_t *pgd, unsigned long addr,
		unsigned long end, pgprot_t prot, struct page **pages, int *nr)
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{
	pud_t *pud;
	unsigned long next;

	pud = pud_alloc(&init_mm, pgd, addr);
	if (!pud)
		return -ENOMEM;
	do {
		next = pud_addr_end(addr, end);
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		if (vmap_pmd_range(pud, addr, next, prot, pages, nr))
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			return -ENOMEM;
	} while (pud++, addr = next, addr != end);
	return 0;
}

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/*
 * 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]
 */
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static int vmap_page_range_noflush(unsigned long start, unsigned long end,
				   pgprot_t prot, struct page **pages)
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{
	pgd_t *pgd;
	unsigned long next;
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	unsigned long addr = start;
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	int err = 0;
	int nr = 0;
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	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	do {
		next = pgd_addr_end(addr, end);
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		err = vmap_pud_range(pgd, addr, next, prot, pages, &nr);
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		if (err)
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			return err;
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	} while (pgd++, addr = next, addr != end);
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	return nr;
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}

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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;
}

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int is_vmalloc_or_module_addr(const void *x)
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{
	/*
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	 * ARM, x86-64 and sparc64 put modules in a special place,
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	 * 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);
}

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/*
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 * Walk a vmap address to the struct page it maps.
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 */
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struct page *vmalloc_to_page(const void *vmalloc_addr)
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{
	unsigned long addr = (unsigned long) vmalloc_addr;
	struct page *page = NULL;
	pgd_t *pgd = pgd_offset_k(addr);

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	/*
	 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
	 * architectures that do not vmalloc module space
	 */
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	VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
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	if (!pgd_none(*pgd)) {
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		pud_t *pud = pud_offset(pgd, addr);
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		if (!pud_none(*pud)) {
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			pmd_t *pmd = pmd_offset(pud, addr);
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			if (!pmd_none(*pmd)) {
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				pte_t *ptep, pte;

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				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.
 */
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unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
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{
	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
}
EXPORT_SYMBOL(vmalloc_to_pfn);

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/*** 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);
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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;

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static unsigned long vmap_area_pcpu_hole;
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static struct vmap_area *__find_vmap_area(unsigned long addr)
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{
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	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) {
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		struct vmap_area *tmp_va;
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		parent = *p;
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		tmp_va = rb_entry(parent, struct vmap_area, rb_node);
		if (va->va_start < tmp_va->va_end)
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			p = &(*p)->rb_left;
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		else if (va->va_end > tmp_va->va_start)
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			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;
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	unsigned long addr;
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	int purged = 0;
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	struct vmap_area *first;
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	BUG_ON(!size);
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	BUG_ON(size & ~PAGE_MASK);
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	BUG_ON(!is_power_of_2(align));
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	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);
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	/*
	 * 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);
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		addr = ALIGN(first->va_end, align);
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		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) {
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			struct vmap_area *tmp;
			tmp = rb_entry(n, struct vmap_area, rb_node);
			if (tmp->va_end >= addr) {
				first = tmp;
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				if (tmp->va_start <= addr)
					break;
				n = n->rb_left;
			} else
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				n = n->rb_right;
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		}
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		if (!first)
			goto found;
	}
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	/* from the starting point, walk areas until a suitable hole is found */
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	while (addr + size > first->va_start && addr + size <= vend) {
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		if (addr + cached_hole_size < first->va_start)
			cached_hole_size = first->va_start - addr;
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		addr = ALIGN(first->va_end, align);
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		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;
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	}

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found:
	if (addr + size > vend)
		goto overflow;
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	va->va_start = addr;
	va->va_end = addr + size;
	va->flags = 0;
	__insert_vmap_area(va);
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	free_vmap_cache = &va->rb_node;
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	spin_unlock(&vmap_area_lock);

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	BUG_ON(va->va_start & (align-1));
	BUG_ON(va->va_start < vstart);
	BUG_ON(va->va_end > vend);

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	return va;
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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);
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}

static void __free_vmap_area(struct vmap_area *va)
{
	BUG_ON(RB_EMPTY_NODE(&va->rb_node));
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	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.
				 */
			}
		}
	}
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	rb_erase(&va->rb_node, &vmap_area_root);
	RB_CLEAR_NODE(&va->rb_node);
	list_del_rcu(&va->list);

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	/*
	 * 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);

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	kfree_rcu(va, rcu_head);
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}

/*
 * 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);
}

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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
}

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/*
 * 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);

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

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/*
 * 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);
}

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/*
 * 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)
{
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	static DEFINE_SPINLOCK(purge_lock);
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	LIST_HEAD(valist);
	struct vmap_area *va;
584
	struct vmap_area *n_va;
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	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) {
593
		if (!spin_trylock(&purge_lock))
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			return;
	} else
596
		spin_lock(&purge_lock);
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598 599 600
	if (sync)
		purge_fragmented_blocks_allcpus();

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	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();

616
	if (nr)
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		atomic_sub(nr, &vmap_lazy_nr);

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

	if (nr) {
		spin_lock(&vmap_area_lock);
624
		list_for_each_entry_safe(va, n_va, &valist, purge_list)
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			__free_vmap_area(va);
		spin_unlock(&vmap_area_lock);
	}
628
	spin_unlock(&purge_lock);
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}

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/*
 * 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);
}

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/*
 * Kick off a purge of the outstanding lazy areas.
 */
static void purge_vmap_area_lazy(void)
{
	unsigned long start = ULONG_MAX, end = 0;

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	__purge_vmap_area_lazy(&start, &end, 1, 0);
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}

/*
653 654 655
 * Free a vmap area, caller ensuring that the area has been unmapped
 * and flush_cache_vunmap had been called for the correct range
 * previously.
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 */
657
static void free_vmap_area_noflush(struct vmap_area *va)
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{
	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()))
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		try_purge_vmap_area_lazy();
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}

665 666 667 668 669 670 671 672 673 674
/*
 * 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);
}

675 676 677 678 679 680 681 682 683
/*
 * 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);
}

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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() */
728 729 730 731
#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))
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#define VMAP_BLOCK_SIZE		(VMAP_BBMAP_BITS * PAGE_SIZE)

735 736
static bool vmap_initialized __read_mostly = false;

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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);
749 750
	struct list_head free_list;
	struct rcu_head rcu_head;
751
	struct list_head purge;
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};

/* 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);
797
	if (IS_ERR(va)) {
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		kfree(vb);
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		return ERR_CAST(va);
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	}

	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);
827
	list_add_rcu(&vb->free_list, &vbq->free);
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	spin_unlock(&vbq->lock);
829
	put_cpu_var(vmap_block_queue);
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	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);

845
	free_vmap_area_noflush(vb->va);
846
	kfree_rcu(vb, rcu_head);
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}

849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896
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);
}

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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;
903
	int purge = 0;
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	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);
916 917 918
		if (vb->free < 1UL << order)
			goto next;

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		i = bitmap_find_free_region(vb->alloc_map,
						VMAP_BBMAP_BITS, order);

922 923 924 925 926
		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;
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			}
928
			goto next;
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		}
930 931 932 933 934 935 936 937 938 939 940 941
		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:
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		spin_unlock(&vb->lock);
	}
944 945 946 947

	if (purge)
		purge_fragmented_blocks_thiscpu();

948
	put_cpu_var(vmap_block_queue);
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	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);
970 971 972

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

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	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);

983 984
	vunmap_page_range((unsigned long)addr, (unsigned long)addr + size);

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	spin_lock(&vb->lock);
986
	BUG_ON(bitmap_allocate_region(vb->dirty_map, offset >> PAGE_SHIFT, order));
987

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	vb->dirty += 1UL << order;
	if (vb->dirty == VMAP_BBMAP_BITS) {
990
		BUG_ON(vb->free);
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		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;

1016 1017 1018
	if (unlikely(!vmap_initialized))
		return;

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	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);
1073
	vmap_debug_free_range(addr, addr+size);
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	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
1088 1089
 *
 * Returns: a pointer to the address that has been mapped, or %NULL on failure
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 */
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);

1120 1121 1122
/**
 * vm_area_register_early - register vmap area early during boot
 * @vm: vm_struct to register
1123
 * @align: requested alignment
1124 1125 1126 1127 1128 1129 1130 1131
 *
 * 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.
 */
1132
void __init vm_area_register_early(struct vm_struct *vm, size_t align)
1133 1134
{
	static size_t vm_init_off __initdata;
1135 1136 1137 1138
	unsigned long addr;

	addr = ALIGN(VMALLOC_START + vm_init_off, align);
	vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START;
1139

1140
	vm->addr = (void *)addr;
1141 1142 1143 1144 1145

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

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void __init vmalloc_init(void)
{
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	struct vmap_area *va;
	struct vm_struct *tmp;
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	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);
	}
1159

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	/* Import existing vmlist entries. */
	for (tmp = vmlist; tmp; tmp = tmp->next) {
1162
		va = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT);
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		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);
	}
1168 1169 1170

	vmap_area_pcpu_hole = VMALLOC_END;

1171
	vmap_initialized = true;
N
Nick Piggin 已提交
1172 1173
}

1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 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
/**
 * 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);
}
1217
EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush);
1218 1219 1220 1221 1222 1223 1224 1225 1226

/**
 * 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.
 */
N
Nick Piggin 已提交
1227 1228 1229
void unmap_kernel_range(unsigned long addr, unsigned long size)
{
	unsigned long end = addr + size;
1230 1231

	flush_cache_vunmap(addr, end);
N
Nick Piggin 已提交
1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255
	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;

1256
static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
1257 1258 1259 1260 1261 1262 1263 1264
			      unsigned long flags, void *caller)
{
	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;
1265
}
1266

1267 1268 1269 1270 1271
static void insert_vmalloc_vmlist(struct vm_struct *vm)
{
	struct vm_struct *tmp, **p;

	vm->flags &= ~VM_UNLIST;
1272 1273 1274 1275 1276 1277 1278 1279 1280 1281
	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);
}

1282 1283 1284 1285 1286 1287 1288
static void insert_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
			      unsigned long flags, void *caller)
{
	setup_vmalloc_vm(vm, va, flags, caller);
	insert_vmalloc_vmlist(vm);
}

N
Nick Piggin 已提交
1289
static struct vm_struct *__get_vm_area_node(unsigned long size,
1290 1291
		unsigned long align, unsigned long flags, unsigned long start,
		unsigned long end, int node, gfp_t gfp_mask, void *caller)
N
Nick Piggin 已提交
1292 1293 1294
{
	static struct vmap_area *va;
	struct vm_struct *area;
L
Linus Torvalds 已提交
1295

1296
	BUG_ON(in_interrupt());
L
Linus Torvalds 已提交
1297 1298 1299 1300 1301 1302 1303 1304 1305 1306
	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;
	}
N
Nick Piggin 已提交
1307

L
Linus Torvalds 已提交
1308
	size = PAGE_ALIGN(size);
1309 1310
	if (unlikely(!size))
		return NULL;
L
Linus Torvalds 已提交
1311

1312
	area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
L
Linus Torvalds 已提交
1313 1314 1315 1316 1317 1318 1319 1320
	if (unlikely(!area))
		return NULL;

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

N
Nick Piggin 已提交
1321 1322 1323 1324
	va = alloc_vmap_area(size, align, start, end, node, gfp_mask);
	if (IS_ERR(va)) {
		kfree(area);
		return NULL;
L
Linus Torvalds 已提交
1325 1326
	}

1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338
	/*
	 * When this function is called from __vmalloc_node_range,
	 * we do not add vm_struct to vmlist here to avoid
	 * accessing uninitialized members of vm_struct such as
	 * pages and nr_pages fields. They will be set later.
	 * To distinguish it from others, we use a VM_UNLIST flag.
	 */
	if (flags & VM_UNLIST)
		setup_vmalloc_vm(area, va, flags, caller);
	else
		insert_vmalloc_vm(area, va, flags, caller);

L
Linus Torvalds 已提交
1339 1340 1341
	return area;
}

C
Christoph Lameter 已提交
1342 1343 1344
struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
				unsigned long start, unsigned long end)
{
1345
	return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1346
						__builtin_return_address(0));
C
Christoph Lameter 已提交
1347
}
1348
EXPORT_SYMBOL_GPL(__get_vm_area);
C
Christoph Lameter 已提交
1349

1350 1351 1352 1353
struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
				       unsigned long start, unsigned long end,
				       void *caller)
{
1354
	return __get_vm_area_node(size, 1, flags, start, end, -1, GFP_KERNEL,
1355 1356 1357
				  caller);
}

L
Linus Torvalds 已提交
1358
/**
S
Simon Arlott 已提交
1359
 *	get_vm_area  -  reserve a contiguous kernel virtual area
L
Linus Torvalds 已提交
1360 1361 1362 1363 1364 1365 1366 1367 1368
 *	@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)
{
1369
	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1370 1371 1372 1373 1374 1375
				-1, GFP_KERNEL, __builtin_return_address(0));
}

struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
				void *caller)
{
1376
	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
1377
						-1, GFP_KERNEL, caller);
L
Linus Torvalds 已提交
1378 1379
}

N
Nick Piggin 已提交
1380
static struct vm_struct *find_vm_area(const void *addr)
1381
{
N
Nick Piggin 已提交
1382
	struct vmap_area *va;
1383

N
Nick Piggin 已提交
1384 1385 1386
	va = find_vmap_area((unsigned long)addr);
	if (va && va->flags & VM_VM_AREA)
		return va->private;
L
Linus Torvalds 已提交
1387 1388 1389 1390

	return NULL;
}

1391
/**
S
Simon Arlott 已提交
1392
 *	remove_vm_area  -  find and remove a continuous kernel virtual area
1393 1394 1395 1396 1397 1398
 *	@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.
 */
1399
struct vm_struct *remove_vm_area(const void *addr)
1400
{
N
Nick Piggin 已提交
1401 1402 1403 1404 1405
	struct vmap_area *va;

	va = find_vmap_area((unsigned long)addr);
	if (va && va->flags & VM_VM_AREA) {
		struct vm_struct *vm = va->private;
1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419

		if (!(vm->flags & VM_UNLIST)) {
			struct vm_struct *tmp, **p;
			/*
			 * remove from list and disallow access to
			 * this vm_struct before unmap. (address range
			 * confliction is maintained by vmap.)
			 */
			write_lock(&vmlist_lock);
			for (p = &vmlist; (tmp = *p) != vm; p = &tmp->next)
				;
			*p = tmp->next;
			write_unlock(&vmlist_lock);
		}
N
Nick Piggin 已提交
1420

1421 1422 1423 1424
		vmap_debug_free_range(va->va_start, va->va_end);
		free_unmap_vmap_area(va);
		vm->size -= PAGE_SIZE;

N
Nick Piggin 已提交
1425 1426 1427
		return vm;
	}
	return NULL;
1428 1429
}

1430
static void __vunmap(const void *addr, int deallocate_pages)
L
Linus Torvalds 已提交
1431 1432 1433 1434 1435 1436 1437
{
	struct vm_struct *area;

	if (!addr)
		return;

	if ((PAGE_SIZE-1) & (unsigned long)addr) {
A
Arjan van de Ven 已提交
1438
		WARN(1, KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
L
Linus Torvalds 已提交
1439 1440 1441 1442 1443
		return;
	}

	area = remove_vm_area(addr);
	if (unlikely(!area)) {
A
Arjan van de Ven 已提交
1444
		WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
L
Linus Torvalds 已提交
1445 1446 1447 1448
				addr);
		return;
	}

1449
	debug_check_no_locks_freed(addr, area->size);
1450
	debug_check_no_obj_freed(addr, area->size);
1451

L
Linus Torvalds 已提交
1452 1453 1454 1455
	if (deallocate_pages) {
		int i;

		for (i = 0; i < area->nr_pages; i++) {
1456 1457 1458 1459
			struct page *page = area->pages[i];

			BUG_ON(!page);
			__free_page(page);
L
Linus Torvalds 已提交
1460 1461
		}

1462
		if (area->flags & VM_VPAGES)
L
Linus Torvalds 已提交
1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475
			vfree(area->pages);
		else
			kfree(area->pages);
	}

	kfree(area);
	return;
}

/**
 *	vfree  -  release memory allocated by vmalloc()
 *	@addr:		memory base address
 *
S
Simon Arlott 已提交
1476
 *	Free the virtually continuous memory area starting at @addr, as
1477 1478
 *	obtained from vmalloc(), vmalloc_32() or __vmalloc(). If @addr is
 *	NULL, no operation is performed.
L
Linus Torvalds 已提交
1479
 *
1480
 *	Must not be called in interrupt context.
L
Linus Torvalds 已提交
1481
 */
1482
void vfree(const void *addr)
L
Linus Torvalds 已提交
1483 1484
{
	BUG_ON(in_interrupt());
1485 1486 1487

	kmemleak_free(addr);

L
Linus Torvalds 已提交
1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498
	__vunmap(addr, 1);
}
EXPORT_SYMBOL(vfree);

/**
 *	vunmap  -  release virtual mapping obtained by vmap()
 *	@addr:		memory base address
 *
 *	Free the virtually contiguous memory area starting at @addr,
 *	which was created from the page array passed to vmap().
 *
1499
 *	Must not be called in interrupt context.
L
Linus Torvalds 已提交
1500
 */
1501
void vunmap(const void *addr)
L
Linus Torvalds 已提交
1502 1503
{
	BUG_ON(in_interrupt());
1504
	might_sleep();
L
Linus Torvalds 已提交
1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523
	__vunmap(addr, 0);
}
EXPORT_SYMBOL(vunmap);

/**
 *	vmap  -  map an array of pages into virtually contiguous space
 *	@pages:		array of page pointers
 *	@count:		number of pages to map
 *	@flags:		vm_area->flags
 *	@prot:		page protection for the mapping
 *
 *	Maps @count pages from @pages into contiguous kernel virtual
 *	space.
 */
void *vmap(struct page **pages, unsigned int count,
		unsigned long flags, pgprot_t prot)
{
	struct vm_struct *area;

1524 1525
	might_sleep();

1526
	if (count > totalram_pages)
L
Linus Torvalds 已提交
1527 1528
		return NULL;

1529 1530
	area = get_vm_area_caller((count << PAGE_SHIFT), flags,
					__builtin_return_address(0));
L
Linus Torvalds 已提交
1531 1532
	if (!area)
		return NULL;
1533

L
Linus Torvalds 已提交
1534 1535 1536 1537 1538 1539 1540 1541 1542
	if (map_vm_area(area, prot, &pages)) {
		vunmap(area->addr);
		return NULL;
	}

	return area->addr;
}
EXPORT_SYMBOL(vmap);

1543 1544
static void *__vmalloc_node(unsigned long size, unsigned long align,
			    gfp_t gfp_mask, pgprot_t prot,
N
Nick Piggin 已提交
1545
			    int node, void *caller);
A
Adrian Bunk 已提交
1546
static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
1547
				 pgprot_t prot, int node, void *caller)
L
Linus Torvalds 已提交
1548
{
1549
	const int order = 0;
L
Linus Torvalds 已提交
1550 1551
	struct page **pages;
	unsigned int nr_pages, array_size, i;
1552
	gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
L
Linus Torvalds 已提交
1553 1554 1555 1556 1557 1558

	nr_pages = (area->size - PAGE_SIZE) >> PAGE_SHIFT;
	array_size = (nr_pages * sizeof(struct page *));

	area->nr_pages = nr_pages;
	/* Please note that the recursion is strictly bounded. */
1559
	if (array_size > PAGE_SIZE) {
1560
		pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM,
1561
				PAGE_KERNEL, node, caller);
1562
		area->flags |= VM_VPAGES;
1563
	} else {
1564
		pages = kmalloc_node(array_size, nested_gfp, node);
1565
	}
L
Linus Torvalds 已提交
1566
	area->pages = pages;
1567
	area->caller = caller;
L
Linus Torvalds 已提交
1568 1569 1570 1571 1572 1573 1574
	if (!area->pages) {
		remove_vm_area(area->addr);
		kfree(area);
		return NULL;
	}

	for (i = 0; i < area->nr_pages; i++) {
1575
		struct page *page;
1576
		gfp_t tmp_mask = gfp_mask | __GFP_NOWARN;
1577

C
Christoph Lameter 已提交
1578
		if (node < 0)
1579
			page = alloc_page(tmp_mask);
C
Christoph Lameter 已提交
1580
		else
1581
			page = alloc_pages_node(node, tmp_mask, order);
1582 1583

		if (unlikely(!page)) {
L
Linus Torvalds 已提交
1584 1585 1586 1587
			/* Successfully allocated i pages, free them in __vunmap() */
			area->nr_pages = i;
			goto fail;
		}
1588
		area->pages[i] = page;
L
Linus Torvalds 已提交
1589 1590 1591 1592 1593 1594 1595
	}

	if (map_vm_area(area, prot, &pages))
		goto fail;
	return area->addr;

fail:
J
Joe Perches 已提交
1596 1597
	warn_alloc_failed(gfp_mask, order,
			  "vmalloc: allocation failure, allocated %ld of %ld bytes\n",
1598
			  (area->nr_pages*PAGE_SIZE), area->size);
L
Linus Torvalds 已提交
1599 1600 1601 1602 1603
	vfree(area->addr);
	return NULL;
}

/**
1604
 *	__vmalloc_node_range  -  allocate virtually contiguous memory
L
Linus Torvalds 已提交
1605
 *	@size:		allocation size
1606
 *	@align:		desired alignment
1607 1608
 *	@start:		vm area range start
 *	@end:		vm area range end
L
Linus Torvalds 已提交
1609 1610
 *	@gfp_mask:	flags for the page level allocator
 *	@prot:		protection mask for the allocated pages
1611
 *	@node:		node to use for allocation or -1
1612
 *	@caller:	caller's return address
L
Linus Torvalds 已提交
1613 1614 1615 1616 1617
 *
 *	Allocate enough pages to cover @size from the page level
 *	allocator with @gfp_mask flags.  Map them into contiguous
 *	kernel virtual space, using a pagetable protection of @prot.
 */
1618 1619 1620
void *__vmalloc_node_range(unsigned long size, unsigned long align,
			unsigned long start, unsigned long end, gfp_t gfp_mask,
			pgprot_t prot, int node, void *caller)
L
Linus Torvalds 已提交
1621 1622
{
	struct vm_struct *area;
1623 1624
	void *addr;
	unsigned long real_size = size;
L
Linus Torvalds 已提交
1625 1626

	size = PAGE_ALIGN(size);
1627
	if (!size || (size >> PAGE_SHIFT) > totalram_pages)
1628
		goto fail;
L
Linus Torvalds 已提交
1629

1630 1631
	area = __get_vm_area_node(size, align, VM_ALLOC | VM_UNLIST,
				  start, end, node, gfp_mask, caller);
L
Linus Torvalds 已提交
1632
	if (!area)
1633
		goto fail;
L
Linus Torvalds 已提交
1634

1635 1636
	addr = __vmalloc_area_node(area, gfp_mask, prot, node, caller);

1637 1638 1639 1640 1641 1642
	/*
	 * In this function, newly allocated vm_struct is not added
	 * to vmlist at __get_vm_area_node(). so, it is added here.
	 */
	insert_vmalloc_vmlist(area);

1643 1644 1645 1646 1647 1648 1649 1650
	/*
	 * A ref_count = 3 is needed because the vm_struct and vmap_area
	 * structures allocated in the __get_vm_area_node() function contain
	 * references to the virtual address of the vmalloc'ed block.
	 */
	kmemleak_alloc(addr, real_size, 3, gfp_mask);

	return addr;
1651 1652 1653 1654 1655 1656

fail:
	warn_alloc_failed(gfp_mask, 0,
			  "vmalloc: allocation failure: %lu bytes\n",
			  real_size);
	return NULL;
L
Linus Torvalds 已提交
1657 1658
}

1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679
/**
 *	__vmalloc_node  -  allocate virtually contiguous memory
 *	@size:		allocation size
 *	@align:		desired alignment
 *	@gfp_mask:	flags for the page level allocator
 *	@prot:		protection mask for the allocated pages
 *	@node:		node to use for allocation or -1
 *	@caller:	caller's return address
 *
 *	Allocate enough pages to cover @size from the page level
 *	allocator with @gfp_mask flags.  Map them into contiguous
 *	kernel virtual space, using a pagetable protection of @prot.
 */
static void *__vmalloc_node(unsigned long size, unsigned long align,
			    gfp_t gfp_mask, pgprot_t prot,
			    int node, void *caller)
{
	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
				gfp_mask, prot, node, caller);
}

C
Christoph Lameter 已提交
1680 1681
void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot)
{
1682
	return __vmalloc_node(size, 1, gfp_mask, prot, -1,
1683
				__builtin_return_address(0));
C
Christoph Lameter 已提交
1684
}
L
Linus Torvalds 已提交
1685 1686
EXPORT_SYMBOL(__vmalloc);

1687 1688 1689 1690 1691 1692 1693
static inline void *__vmalloc_node_flags(unsigned long size,
					int node, gfp_t flags)
{
	return __vmalloc_node(size, 1, flags, PAGE_KERNEL,
					node, __builtin_return_address(0));
}

L
Linus Torvalds 已提交
1694 1695 1696 1697 1698 1699
/**
 *	vmalloc  -  allocate virtually contiguous memory
 *	@size:		allocation size
 *	Allocate enough pages to cover @size from the page level
 *	allocator and map them into contiguous kernel virtual space.
 *
1700
 *	For tight control over page level allocator and protection flags
L
Linus Torvalds 已提交
1701 1702 1703 1704
 *	use __vmalloc() instead.
 */
void *vmalloc(unsigned long size)
{
1705
	return __vmalloc_node_flags(size, -1, GFP_KERNEL | __GFP_HIGHMEM);
L
Linus Torvalds 已提交
1706 1707 1708
}
EXPORT_SYMBOL(vmalloc);

1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725
/**
 *	vzalloc - allocate virtually contiguous memory with zero fill
 *	@size:	allocation size
 *	Allocate enough pages to cover @size from the page level
 *	allocator and map them into contiguous kernel virtual space.
 *	The memory allocated is set to zero.
 *
 *	For tight control over page level allocator and protection flags
 *	use __vmalloc() instead.
 */
void *vzalloc(unsigned long size)
{
	return __vmalloc_node_flags(size, -1,
				GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
}
EXPORT_SYMBOL(vzalloc);

1726
/**
1727 1728
 * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
 * @size: allocation size
1729
 *
1730 1731
 * The resulting memory area is zeroed so it can be mapped to userspace
 * without leaking data.
1732 1733 1734 1735 1736 1737
 */
void *vmalloc_user(unsigned long size)
{
	struct vm_struct *area;
	void *ret;

1738 1739
	ret = __vmalloc_node(size, SHMLBA,
			     GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO,
G
Glauber Costa 已提交
1740
			     PAGE_KERNEL, -1, __builtin_return_address(0));
1741
	if (ret) {
N
Nick Piggin 已提交
1742
		area = find_vm_area(ret);
1743 1744
		area->flags |= VM_USERMAP;
	}
1745 1746 1747 1748
	return ret;
}
EXPORT_SYMBOL(vmalloc_user);

C
Christoph Lameter 已提交
1749 1750 1751
/**
 *	vmalloc_node  -  allocate memory on a specific node
 *	@size:		allocation size
1752
 *	@node:		numa node
C
Christoph Lameter 已提交
1753 1754 1755 1756
 *
 *	Allocate enough pages to cover @size from the page level
 *	allocator and map them into contiguous kernel virtual space.
 *
1757
 *	For tight control over page level allocator and protection flags
C
Christoph Lameter 已提交
1758 1759 1760 1761
 *	use __vmalloc() instead.
 */
void *vmalloc_node(unsigned long size, int node)
{
1762
	return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL,
1763
					node, __builtin_return_address(0));
C
Christoph Lameter 已提交
1764 1765 1766
}
EXPORT_SYMBOL(vmalloc_node);

1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785
/**
 * vzalloc_node - allocate memory on a specific node with zero fill
 * @size:	allocation size
 * @node:	numa node
 *
 * Allocate enough pages to cover @size from the page level
 * allocator and map them into contiguous kernel virtual space.
 * The memory allocated is set to zero.
 *
 * For tight control over page level allocator and protection flags
 * use __vmalloc_node() instead.
 */
void *vzalloc_node(unsigned long size, int node)
{
	return __vmalloc_node_flags(size, node,
			 GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO);
}
EXPORT_SYMBOL(vzalloc_node);

1786 1787 1788 1789
#ifndef PAGE_KERNEL_EXEC
# define PAGE_KERNEL_EXEC PAGE_KERNEL
#endif

L
Linus Torvalds 已提交
1790 1791 1792 1793 1794 1795 1796 1797
/**
 *	vmalloc_exec  -  allocate virtually contiguous, executable memory
 *	@size:		allocation size
 *
 *	Kernel-internal function to allocate enough pages to cover @size
 *	the page level allocator and map them into contiguous and
 *	executable kernel virtual space.
 *
1798
 *	For tight control over page level allocator and protection flags
L
Linus Torvalds 已提交
1799 1800 1801 1802 1803
 *	use __vmalloc() instead.
 */

void *vmalloc_exec(unsigned long size)
{
1804
	return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC,
G
Glauber Costa 已提交
1805
			      -1, __builtin_return_address(0));
L
Linus Torvalds 已提交
1806 1807
}

1808
#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
1809
#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
1810
#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
1811
#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
1812 1813 1814 1815
#else
#define GFP_VMALLOC32 GFP_KERNEL
#endif

L
Linus Torvalds 已提交
1816 1817 1818 1819 1820 1821 1822 1823 1824
/**
 *	vmalloc_32  -  allocate virtually contiguous memory (32bit addressable)
 *	@size:		allocation size
 *
 *	Allocate enough 32bit PA addressable pages to cover @size from the
 *	page level allocator and map them into contiguous kernel virtual space.
 */
void *vmalloc_32(unsigned long size)
{
1825
	return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL,
G
Glauber Costa 已提交
1826
			      -1, __builtin_return_address(0));
L
Linus Torvalds 已提交
1827 1828 1829
}
EXPORT_SYMBOL(vmalloc_32);

1830
/**
1831
 * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
1832
 *	@size:		allocation size
1833 1834 1835
 *
 * The resulting memory area is 32bit addressable and zeroed so it can be
 * mapped to userspace without leaking data.
1836 1837 1838 1839 1840 1841
 */
void *vmalloc_32_user(unsigned long size)
{
	struct vm_struct *area;
	void *ret;

1842
	ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
G
Glauber Costa 已提交
1843
			     -1, __builtin_return_address(0));
1844
	if (ret) {
N
Nick Piggin 已提交
1845
		area = find_vm_area(ret);
1846 1847
		area->flags |= VM_USERMAP;
	}
1848 1849 1850 1851
	return ret;
}
EXPORT_SYMBOL(vmalloc_32_user);

1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960
/*
 * small helper routine , copy contents to buf from addr.
 * If the page is not present, fill zero.
 */

static int aligned_vread(char *buf, char *addr, unsigned long count)
{
	struct page *p;
	int copied = 0;

	while (count) {
		unsigned long offset, length;

		offset = (unsigned long)addr & ~PAGE_MASK;
		length = PAGE_SIZE - offset;
		if (length > count)
			length = count;
		p = vmalloc_to_page(addr);
		/*
		 * To do safe access to this _mapped_ area, we need
		 * lock. But adding lock here means that we need to add
		 * overhead of vmalloc()/vfree() calles for this _debug_
		 * interface, rarely used. Instead of that, we'll use
		 * kmap() and get small overhead in this access function.
		 */
		if (p) {
			/*
			 * we can expect USER0 is not used (see vread/vwrite's
			 * function description)
			 */
			void *map = kmap_atomic(p, KM_USER0);
			memcpy(buf, map + offset, length);
			kunmap_atomic(map, KM_USER0);
		} else
			memset(buf, 0, length);

		addr += length;
		buf += length;
		copied += length;
		count -= length;
	}
	return copied;
}

static int aligned_vwrite(char *buf, char *addr, unsigned long count)
{
	struct page *p;
	int copied = 0;

	while (count) {
		unsigned long offset, length;

		offset = (unsigned long)addr & ~PAGE_MASK;
		length = PAGE_SIZE - offset;
		if (length > count)
			length = count;
		p = vmalloc_to_page(addr);
		/*
		 * To do safe access to this _mapped_ area, we need
		 * lock. But adding lock here means that we need to add
		 * overhead of vmalloc()/vfree() calles for this _debug_
		 * interface, rarely used. Instead of that, we'll use
		 * kmap() and get small overhead in this access function.
		 */
		if (p) {
			/*
			 * we can expect USER0 is not used (see vread/vwrite's
			 * function description)
			 */
			void *map = kmap_atomic(p, KM_USER0);
			memcpy(map + offset, buf, length);
			kunmap_atomic(map, KM_USER0);
		}
		addr += length;
		buf += length;
		copied += length;
		count -= length;
	}
	return copied;
}

/**
 *	vread() -  read vmalloc area in a safe way.
 *	@buf:		buffer for reading data
 *	@addr:		vm address.
 *	@count:		number of bytes to be read.
 *
 *	Returns # of bytes which addr and buf should be increased.
 *	(same number to @count). Returns 0 if [addr...addr+count) doesn't
 *	includes any intersect with alive vmalloc area.
 *
 *	This function checks that addr is a valid vmalloc'ed area, and
 *	copy data from that area to a given buffer. If the given memory range
 *	of [addr...addr+count) includes some valid address, data is copied to
 *	proper area of @buf. If there are memory holes, they'll be zero-filled.
 *	IOREMAP area is treated as memory hole and no copy is done.
 *
 *	If [addr...addr+count) doesn't includes any intersects with alive
 *	vm_struct area, returns 0.
 *	@buf should be kernel's buffer. Because	this function uses KM_USER0,
 *	the caller should guarantee KM_USER0 is not used.
 *
 *	Note: In usual ops, vread() is never necessary because the caller
 *	should know vmalloc() area is valid and can use memcpy().
 *	This is for routines which have to access vmalloc area without
 *	any informaion, as /dev/kmem.
 *
 */

L
Linus Torvalds 已提交
1961 1962 1963 1964
long vread(char *buf, char *addr, unsigned long count)
{
	struct vm_struct *tmp;
	char *vaddr, *buf_start = buf;
1965
	unsigned long buflen = count;
L
Linus Torvalds 已提交
1966 1967 1968 1969 1970 1971 1972
	unsigned long n;

	/* Don't allow overflow */
	if ((unsigned long) addr + count < count)
		count = -(unsigned long) addr;

	read_lock(&vmlist_lock);
1973
	for (tmp = vmlist; count && tmp; tmp = tmp->next) {
L
Linus Torvalds 已提交
1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985
		vaddr = (char *) tmp->addr;
		if (addr >= vaddr + tmp->size - PAGE_SIZE)
			continue;
		while (addr < vaddr) {
			if (count == 0)
				goto finished;
			*buf = '\0';
			buf++;
			addr++;
			count--;
		}
		n = vaddr + tmp->size - PAGE_SIZE - addr;
1986 1987 1988 1989 1990 1991 1992 1993 1994
		if (n > count)
			n = count;
		if (!(tmp->flags & VM_IOREMAP))
			aligned_vread(buf, addr, n);
		else /* IOREMAP area is treated as memory hole */
			memset(buf, 0, n);
		buf += n;
		addr += n;
		count -= n;
L
Linus Torvalds 已提交
1995 1996 1997
	}
finished:
	read_unlock(&vmlist_lock);
1998 1999 2000 2001 2002 2003 2004 2005

	if (buf == buf_start)
		return 0;
	/* zero-fill memory holes */
	if (buf != buf_start + buflen)
		memset(buf, 0, buflen - (buf - buf_start));

	return buflen;
L
Linus Torvalds 已提交
2006 2007
}

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035
/**
 *	vwrite() -  write vmalloc area in a safe way.
 *	@buf:		buffer for source data
 *	@addr:		vm address.
 *	@count:		number of bytes to be read.
 *
 *	Returns # of bytes which addr and buf should be incresed.
 *	(same number to @count).
 *	If [addr...addr+count) doesn't includes any intersect with valid
 *	vmalloc area, returns 0.
 *
 *	This function checks that addr is a valid vmalloc'ed area, and
 *	copy data from a buffer to the given addr. If specified range of
 *	[addr...addr+count) includes some valid address, data is copied from
 *	proper area of @buf. If there are memory holes, no copy to hole.
 *	IOREMAP area is treated as memory hole and no copy is done.
 *
 *	If [addr...addr+count) doesn't includes any intersects with alive
 *	vm_struct area, returns 0.
 *	@buf should be kernel's buffer. Because	this function uses KM_USER0,
 *	the caller should guarantee KM_USER0 is not used.
 *
 *	Note: In usual ops, vwrite() is never necessary because the caller
 *	should know vmalloc() area is valid and can use memcpy().
 *	This is for routines which have to access vmalloc area without
 *	any informaion, as /dev/kmem.
 */

L
Linus Torvalds 已提交
2036 2037 2038
long vwrite(char *buf, char *addr, unsigned long count)
{
	struct vm_struct *tmp;
2039 2040 2041
	char *vaddr;
	unsigned long n, buflen;
	int copied = 0;
L
Linus Torvalds 已提交
2042 2043 2044 2045

	/* Don't allow overflow */
	if ((unsigned long) addr + count < count)
		count = -(unsigned long) addr;
2046
	buflen = count;
L
Linus Torvalds 已提交
2047 2048

	read_lock(&vmlist_lock);
2049
	for (tmp = vmlist; count && tmp; tmp = tmp->next) {
L
Linus Torvalds 已提交
2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060
		vaddr = (char *) tmp->addr;
		if (addr >= vaddr + tmp->size - PAGE_SIZE)
			continue;
		while (addr < vaddr) {
			if (count == 0)
				goto finished;
			buf++;
			addr++;
			count--;
		}
		n = vaddr + tmp->size - PAGE_SIZE - addr;
2061 2062 2063 2064 2065 2066 2067 2068 2069
		if (n > count)
			n = count;
		if (!(tmp->flags & VM_IOREMAP)) {
			aligned_vwrite(buf, addr, n);
			copied++;
		}
		buf += n;
		addr += n;
		count -= n;
L
Linus Torvalds 已提交
2070 2071 2072
	}
finished:
	read_unlock(&vmlist_lock);
2073 2074 2075
	if (!copied)
		return 0;
	return buflen;
L
Linus Torvalds 已提交
2076
}
2077 2078 2079 2080 2081 2082

/**
 *	remap_vmalloc_range  -  map vmalloc pages to userspace
 *	@vma:		vma to cover (map full range of vma)
 *	@addr:		vmalloc memory
 *	@pgoff:		number of pages into addr before first page to map
2083 2084
 *
 *	Returns:	0 for success, -Exxx on failure
2085 2086 2087 2088 2089
 *
 *	This function checks that addr is a valid vmalloc'ed area, and
 *	that it is big enough to cover the vma. Will return failure if
 *	that criteria isn't met.
 *
2090
 *	Similar to remap_pfn_range() (see mm/memory.c)
2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101
 */
int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
						unsigned long pgoff)
{
	struct vm_struct *area;
	unsigned long uaddr = vma->vm_start;
	unsigned long usize = vma->vm_end - vma->vm_start;

	if ((PAGE_SIZE-1) & (unsigned long)addr)
		return -EINVAL;

N
Nick Piggin 已提交
2102
	area = find_vm_area(addr);
2103
	if (!area)
N
Nick Piggin 已提交
2104
		return -EINVAL;
2105 2106

	if (!(area->flags & VM_USERMAP))
N
Nick Piggin 已提交
2107
		return -EINVAL;
2108 2109

	if (usize + (pgoff << PAGE_SHIFT) > area->size - PAGE_SIZE)
N
Nick Piggin 已提交
2110
		return -EINVAL;
2111 2112 2113 2114

	addr += pgoff << PAGE_SHIFT;
	do {
		struct page *page = vmalloc_to_page(addr);
N
Nick Piggin 已提交
2115 2116
		int ret;

2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128
		ret = vm_insert_page(vma, uaddr, page);
		if (ret)
			return ret;

		uaddr += PAGE_SIZE;
		addr += PAGE_SIZE;
		usize -= PAGE_SIZE;
	} while (usize > 0);

	/* Prevent "things" like memory migration? VM_flags need a cleanup... */
	vma->vm_flags |= VM_RESERVED;

N
Nick Piggin 已提交
2129
	return 0;
2130 2131 2132
}
EXPORT_SYMBOL(remap_vmalloc_range);

2133 2134 2135 2136 2137 2138 2139
/*
 * Implement a stub for vmalloc_sync_all() if the architecture chose not to
 * have one.
 */
void  __attribute__((weak)) vmalloc_sync_all(void)
{
}
2140 2141


2142
static int f(pte_t *pte, pgtable_t table, unsigned long addr, void *data)
2143 2144 2145 2146 2147 2148 2149 2150
{
	/* apply_to_page_range() does all the hard work. */
	return 0;
}

/**
 *	alloc_vm_area - allocate a range of kernel address space
 *	@size:		size of the area
2151 2152
 *
 *	Returns:	NULL on failure, vm_struct on success
2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163
 *
 *	This function reserves a range of kernel address space, and
 *	allocates pagetables to map that range.  No actual mappings
 *	are created.  If the kernel address space is not shared
 *	between processes, it syncs the pagetable across all
 *	processes.
 */
struct vm_struct *alloc_vm_area(size_t size)
{
	struct vm_struct *area;

2164 2165
	area = get_vm_area_caller(size, VM_IOREMAP,
				__builtin_return_address(0));
2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178
	if (area == NULL)
		return NULL;

	/*
	 * This ensures that page tables are constructed for this region
	 * of kernel virtual address space and mapped into init_mm.
	 */
	if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
				area->size, f, NULL)) {
		free_vm_area(area);
		return NULL;
	}

2179 2180 2181 2182 2183 2184 2185 2186
	/*
	 * If the allocated address space is passed to a hypercall
	 * before being used then we cannot rely on a page fault to
	 * trigger an update of the page tables.  So sync all the page
	 * tables here.
	 */
	vmalloc_sync_all();

2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198
	return area;
}
EXPORT_SYMBOL_GPL(alloc_vm_area);

void free_vm_area(struct vm_struct *area)
{
	struct vm_struct *ret;
	ret = remove_vm_area(area->addr);
	BUG_ON(ret != area);
	kfree(area);
}
EXPORT_SYMBOL_GPL(free_vm_area);
2199

2200
#ifdef CONFIG_SMP
2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295
static struct vmap_area *node_to_va(struct rb_node *n)
{
	return n ? rb_entry(n, struct vmap_area, rb_node) : NULL;
}

/**
 * pvm_find_next_prev - find the next and prev vmap_area surrounding @end
 * @end: target address
 * @pnext: out arg for the next vmap_area
 * @pprev: out arg for the previous vmap_area
 *
 * Returns: %true if either or both of next and prev are found,
 *	    %false if no vmap_area exists
 *
 * Find vmap_areas end addresses of which enclose @end.  ie. if not
 * NULL, *pnext->va_end > @end and *pprev->va_end <= @end.
 */
static bool pvm_find_next_prev(unsigned long end,
			       struct vmap_area **pnext,
			       struct vmap_area **pprev)
{
	struct rb_node *n = vmap_area_root.rb_node;
	struct vmap_area *va = NULL;

	while (n) {
		va = rb_entry(n, struct vmap_area, rb_node);
		if (end < va->va_end)
			n = n->rb_left;
		else if (end > va->va_end)
			n = n->rb_right;
		else
			break;
	}

	if (!va)
		return false;

	if (va->va_end > end) {
		*pnext = va;
		*pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
	} else {
		*pprev = va;
		*pnext = node_to_va(rb_next(&(*pprev)->rb_node));
	}
	return true;
}

/**
 * pvm_determine_end - find the highest aligned address between two vmap_areas
 * @pnext: in/out arg for the next vmap_area
 * @pprev: in/out arg for the previous vmap_area
 * @align: alignment
 *
 * Returns: determined end address
 *
 * Find the highest aligned address between *@pnext and *@pprev below
 * VMALLOC_END.  *@pnext and *@pprev are adjusted so that the aligned
 * down address is between the end addresses of the two vmap_areas.
 *
 * Please note that the address returned by this function may fall
 * inside *@pnext vmap_area.  The caller is responsible for checking
 * that.
 */
static unsigned long pvm_determine_end(struct vmap_area **pnext,
				       struct vmap_area **pprev,
				       unsigned long align)
{
	const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
	unsigned long addr;

	if (*pnext)
		addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end);
	else
		addr = vmalloc_end;

	while (*pprev && (*pprev)->va_end > addr) {
		*pnext = *pprev;
		*pprev = node_to_va(rb_prev(&(*pnext)->rb_node));
	}

	return addr;
}

/**
 * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
 * @offsets: array containing offset of each area
 * @sizes: array containing size of each area
 * @nr_vms: the number of areas to allocate
 * @align: alignment, all entries in @offsets and @sizes must be aligned to this
 *
 * Returns: kmalloc'd vm_struct pointer array pointing to allocated
 *	    vm_structs on success, %NULL on failure
 *
 * Percpu allocator wants to use congruent vm areas so that it can
 * maintain the offsets among percpu areas.  This function allocates
2296 2297 2298 2299
 * congruent vmalloc areas for it with GFP_KERNEL.  These areas tend to
 * be scattered pretty far, distance between two areas easily going up
 * to gigabytes.  To avoid interacting with regular vmallocs, these
 * areas are allocated from top.
2300 2301 2302 2303 2304 2305 2306 2307 2308 2309
 *
 * Despite its complicated look, this allocator is rather simple.  It
 * does everything top-down and scans areas from the end looking for
 * matching slot.  While scanning, if any of the areas overlaps with
 * existing vmap_area, the base address is pulled down to fit the
 * area.  Scanning is repeated till all the areas fit and then all
 * necessary data structres are inserted and the result is returned.
 */
struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
				     const size_t *sizes, int nr_vms,
2310
				     size_t align)
2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351
{
	const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
	const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
	struct vmap_area **vas, *prev, *next;
	struct vm_struct **vms;
	int area, area2, last_area, term_area;
	unsigned long base, start, end, last_end;
	bool purged = false;

	/* verify parameters and allocate data structures */
	BUG_ON(align & ~PAGE_MASK || !is_power_of_2(align));
	for (last_area = 0, area = 0; area < nr_vms; area++) {
		start = offsets[area];
		end = start + sizes[area];

		/* is everything aligned properly? */
		BUG_ON(!IS_ALIGNED(offsets[area], align));
		BUG_ON(!IS_ALIGNED(sizes[area], align));

		/* detect the area with the highest address */
		if (start > offsets[last_area])
			last_area = area;

		for (area2 = 0; area2 < nr_vms; area2++) {
			unsigned long start2 = offsets[area2];
			unsigned long end2 = start2 + sizes[area2];

			if (area2 == area)
				continue;

			BUG_ON(start2 >= start && start2 < end);
			BUG_ON(end2 <= end && end2 > start);
		}
	}
	last_end = offsets[last_area] + sizes[last_area];

	if (vmalloc_end - vmalloc_start < last_end) {
		WARN_ON(true);
		return NULL;
	}

2352 2353
	vms = kzalloc(sizeof(vms[0]) * nr_vms, GFP_KERNEL);
	vas = kzalloc(sizeof(vas[0]) * nr_vms, GFP_KERNEL);
2354 2355 2356 2357
	if (!vas || !vms)
		goto err_free;

	for (area = 0; area < nr_vms; area++) {
2358 2359
		vas[area] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL);
		vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477
		if (!vas[area] || !vms[area])
			goto err_free;
	}
retry:
	spin_lock(&vmap_area_lock);

	/* start scanning - we scan from the top, begin with the last area */
	area = term_area = last_area;
	start = offsets[area];
	end = start + sizes[area];

	if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) {
		base = vmalloc_end - last_end;
		goto found;
	}
	base = pvm_determine_end(&next, &prev, align) - end;

	while (true) {
		BUG_ON(next && next->va_end <= base + end);
		BUG_ON(prev && prev->va_end > base + end);

		/*
		 * base might have underflowed, add last_end before
		 * comparing.
		 */
		if (base + last_end < vmalloc_start + last_end) {
			spin_unlock(&vmap_area_lock);
			if (!purged) {
				purge_vmap_area_lazy();
				purged = true;
				goto retry;
			}
			goto err_free;
		}

		/*
		 * If next overlaps, move base downwards so that it's
		 * right below next and then recheck.
		 */
		if (next && next->va_start < base + end) {
			base = pvm_determine_end(&next, &prev, align) - end;
			term_area = area;
			continue;
		}

		/*
		 * If prev overlaps, shift down next and prev and move
		 * base so that it's right below new next and then
		 * recheck.
		 */
		if (prev && prev->va_end > base + start)  {
			next = prev;
			prev = node_to_va(rb_prev(&next->rb_node));
			base = pvm_determine_end(&next, &prev, align) - end;
			term_area = area;
			continue;
		}

		/*
		 * This area fits, move on to the previous one.  If
		 * the previous one is the terminal one, we're done.
		 */
		area = (area + nr_vms - 1) % nr_vms;
		if (area == term_area)
			break;
		start = offsets[area];
		end = start + sizes[area];
		pvm_find_next_prev(base + end, &next, &prev);
	}
found:
	/* we've found a fitting base, insert all va's */
	for (area = 0; area < nr_vms; area++) {
		struct vmap_area *va = vas[area];

		va->va_start = base + offsets[area];
		va->va_end = va->va_start + sizes[area];
		__insert_vmap_area(va);
	}

	vmap_area_pcpu_hole = base + offsets[last_area];

	spin_unlock(&vmap_area_lock);

	/* insert all vm's */
	for (area = 0; area < nr_vms; area++)
		insert_vmalloc_vm(vms[area], vas[area], VM_ALLOC,
				  pcpu_get_vm_areas);

	kfree(vas);
	return vms;

err_free:
	for (area = 0; area < nr_vms; area++) {
		if (vas)
			kfree(vas[area]);
		if (vms)
			kfree(vms[area]);
	}
	kfree(vas);
	kfree(vms);
	return NULL;
}

/**
 * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
 * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
 * @nr_vms: the number of allocated areas
 *
 * Free vm_structs and the array allocated by pcpu_get_vm_areas().
 */
void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
{
	int i;

	for (i = 0; i < nr_vms; i++)
		free_vm_area(vms[i]);
	kfree(vms);
}
2478
#endif	/* CONFIG_SMP */
2479 2480 2481

#ifdef CONFIG_PROC_FS
static void *s_start(struct seq_file *m, loff_t *pos)
2482
	__acquires(&vmlist_lock)
2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508
{
	loff_t n = *pos;
	struct vm_struct *v;

	read_lock(&vmlist_lock);
	v = vmlist;
	while (n > 0 && v) {
		n--;
		v = v->next;
	}
	if (!n)
		return v;

	return NULL;

}

static void *s_next(struct seq_file *m, void *p, loff_t *pos)
{
	struct vm_struct *v = p;

	++*pos;
	return v->next;
}

static void s_stop(struct seq_file *m, void *p)
2509
	__releases(&vmlist_lock)
2510 2511 2512 2513
{
	read_unlock(&vmlist_lock);
}

E
Eric Dumazet 已提交
2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532
static void show_numa_info(struct seq_file *m, struct vm_struct *v)
{
	if (NUMA_BUILD) {
		unsigned int nr, *counters = m->private;

		if (!counters)
			return;

		memset(counters, 0, nr_node_ids * sizeof(unsigned int));

		for (nr = 0; nr < v->nr_pages; nr++)
			counters[page_to_nid(v->pages[nr])]++;

		for_each_node_state(nr, N_HIGH_MEMORY)
			if (counters[nr])
				seq_printf(m, " N%u=%u", nr, counters[nr]);
	}
}

2533 2534 2535 2536 2537 2538 2539
static int s_show(struct seq_file *m, void *p)
{
	struct vm_struct *v = p;

	seq_printf(m, "0x%p-0x%p %7ld",
		v->addr, v->addr + v->size, v->size);

J
Joe Perches 已提交
2540 2541
	if (v->caller)
		seq_printf(m, " %pS", v->caller);
2542

2543 2544 2545 2546
	if (v->nr_pages)
		seq_printf(m, " pages=%d", v->nr_pages);

	if (v->phys_addr)
2547
		seq_printf(m, " phys=%llx", (unsigned long long)v->phys_addr);
2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563

	if (v->flags & VM_IOREMAP)
		seq_printf(m, " ioremap");

	if (v->flags & VM_ALLOC)
		seq_printf(m, " vmalloc");

	if (v->flags & VM_MAP)
		seq_printf(m, " vmap");

	if (v->flags & VM_USERMAP)
		seq_printf(m, " user");

	if (v->flags & VM_VPAGES)
		seq_printf(m, " vpages");

E
Eric Dumazet 已提交
2564
	show_numa_info(m, v);
2565 2566 2567 2568
	seq_putc(m, '\n');
	return 0;
}

2569
static const struct seq_operations vmalloc_op = {
2570 2571 2572 2573 2574
	.start = s_start,
	.next = s_next,
	.stop = s_stop,
	.show = s_show,
};
2575 2576 2577 2578 2579 2580

static int vmalloc_open(struct inode *inode, struct file *file)
{
	unsigned int *ptr = NULL;
	int ret;

2581
	if (NUMA_BUILD) {
2582
		ptr = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL);
2583 2584 2585
		if (ptr == NULL)
			return -ENOMEM;
	}
2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607
	ret = seq_open(file, &vmalloc_op);
	if (!ret) {
		struct seq_file *m = file->private_data;
		m->private = ptr;
	} else
		kfree(ptr);
	return ret;
}

static const struct file_operations proc_vmalloc_operations = {
	.open		= vmalloc_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= seq_release_private,
};

static int __init proc_vmalloc_init(void)
{
	proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations);
	return 0;
}
module_init(proc_vmalloc_init);
2608 2609
#endif