path: root/mm/vmalloc.c

/*
 *  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
 *  Numa awareness, Christoph Lameter, SGI, June 2005
 */

#include <linux/mm.h>
#include <linux/module.h>
#include <linux/highmem.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/seq_file.h>
#include <linux/debugobjects.h>
#include <linux/vmalloc.h>
#include <linux/kallsyms.h>

#include <asm/uaccess.h>
#include <asm/tlbflush.h>


DEFINE_RWLOCK(vmlist_lock);
struct vm_struct *vmlist;

static void *__vmalloc_node(unsigned long size, gfp_t gfp_mask, pgprot_t prot,
			    int node, void *caller);

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);
}

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

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

void unmap_kernel_range(unsigned long addr, unsigned long size)
{
	pgd_t *pgd;
	unsigned long next;
	unsigned long start = addr;
	unsigned long end = addr + size;

	BUG_ON(addr >= end);
	pgd = pgd_offset_k(addr);
	flush_cache_vunmap(addr, end);
	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);
	flush_tlb_kernel_range(start, end);
}

static void unmap_vm_area(struct vm_struct *area)
{
	unmap_kernel_range((unsigned long)area->addr, area->size);
}

static int vmap_pte_range(pmd_t *pmd, unsigned long addr,
			unsigned long end, pgprot_t prot, struct page ***pages)
{
	pte_t *pte;

	pte = pte_alloc_kernel(pmd, addr);
	if (!pte)
		return -ENOMEM;
	do {
		struct page *page = **pages;
		WARN_ON(!pte_none(*pte));
		if (!page)
			return -ENOMEM;
		set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
		(*pages)++;
	} while (pte++, addr += PAGE_SIZE, addr != end);
	return 0;
}

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

	pmd = pmd_alloc(&init_mm, pud, addr);
	if (!pmd)
		return -ENOMEM;
	do {
		next = pmd_addr_end(addr, end);
		if (vmap_pte_range(pmd, addr, next, prot, pages))
			return -ENOMEM;
	</