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/*
* linux/mm/vmalloc.c
*
* Copyright (C) 1993 Linus Torvalds
*/
#include <linux/malloc.h>
#include <linux/vmalloc.h>
#include <asm/uaccess.h>
#include <asm/system.h>
static struct vm_struct * vmlist = NULL;
static inline void free_area_pte(pmd_t * pmd, unsigned long address, unsigned long size)
{
pte_t * pte;
unsigned long end;
if (pmd_none(*pmd))
return;
if (pmd_bad(*pmd)) {
printk("free_area_pte: bad pmd (%08lx)\n", pmd_val(*pmd));
pmd_clear(pmd);
return;
}
pte = pte_offset(pmd, address);
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
while (address < end) {
pte_t page = *pte;
pte_clear(pte);
address += PAGE_SIZE;
pte++;
if (pte_none(page))
continue;
if (pte_present(page)) {
free_page(pte_page(page));
continue;
}
printk("Whee.. Swapped out page in kernel page table\n");
}
}
static inline void free_area_pmd(pgd_t * dir, unsigned long address, unsigned long size)
{
pmd_t * pmd;
unsigned long end;
if (pgd_none(*dir))
return;
if (pgd_bad(*dir)) {
printk("free_area_pmd: bad pgd (%08lx)\n", pgd_val(*dir));
pgd_clear(dir);
return;
}
pmd = pmd_offset(dir, address);
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
while (address < end) {
free_area_pte(pmd, address, end - address);
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
}
}
void vmfree_area_pages(unsigned long address, unsigned long size)
{
pgd_t * dir;
unsigned long end = address + size;
dir = pgd_offset_k(address);
flush_cache_all();
while (address < end) {
free_area_pmd(dir, address, end - address);
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
}
flush_tlb_all();
}
static inline int alloc_area_pte(pte_t * pte, unsigned long address, unsigned long size, pgprot_t prot)
{
unsigned long end;
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
while (address < end) {
unsigned long page;
if (!pte_none(*pte))
printk("alloc_area_pte: page already exists\n");
page = __get_free_page(GFP_KERNEL);
if (!page)
return -ENOMEM;
set_pte(pte, mk_pte(page, prot));
address += PAGE_SIZE;
pte++;
}
return 0;
}
static inline int alloc_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size, pgprot_t prot)
{
unsigned long end;
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
while (address < end) {
pte_t * pte = pte_alloc_kernel(pmd, address);
if (!pte)
return -ENOMEM;
if (alloc_area_pte(pte, address, end - address, prot))
return -ENOMEM;
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
}
return 0;
}
int vmalloc_area_pages(unsigned long address, unsigned long size, pgprot_t prot)
{
pgd_t * dir;
unsigned long end = address + size;
dir = pgd_offset_k(address);
flush_cache_all();
while (address < end) {
pmd_t *pmd = pmd_alloc_kernel(dir, address);
if (!pmd)
return -ENOMEM;
if (alloc_area_pmd(pmd, address, end - address, prot))
return -ENOMEM;
set_pgdir(address, *dir);
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
}
flush_tlb_all();
return 0;
}
struct vm_struct * get_vm_area(unsigned long size)
{
void *addr;
struct vm_struct **p, *tmp, *area;
area = (struct vm_struct *) kmalloc(sizeof(*area), GFP_KERNEL);
if (!area)
return NULL;
addr = (void *) VMALLOC_START;
area->size = size + PAGE_SIZE;
area->next = NULL;
for (p = &vmlist; (tmp = *p) ; p = &tmp->next) {
if (size + (unsigned long) addr < (unsigned long) tmp->addr)
break;
addr = (void *) (tmp->size + (unsigned long) tmp->addr);
}
area->addr = addr;
area->next = *p;
*p = area;
return area;
}
void vfree(void * addr)
{
struct vm_struct **p, *tmp;
if (!addr)
return;
if ((PAGE_SIZE-1) & (unsigned long) addr) {
printk("Trying to vfree() bad address (%p)\n", addr);
return;
}
for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) {
if (tmp->addr == addr) {
*p = tmp->next;
vmfree_area_pages(VMALLOC_VMADDR(tmp->addr), tmp->size);
kfree(tmp);
return;
}
}
printk("Trying to vfree() nonexistent vm area (%p)\n", addr);
}
void * vmalloc_prot(unsigned long size, pgprot_t prot)
{
void * addr;
struct vm_struct *area;
size = PAGE_ALIGN(size);
if (!size || size > (max_mapnr << PAGE_SHIFT))
return NULL;
area = get_vm_area(size);
if (!area)
return NULL;
addr = area->addr;
if (vmalloc_area_pages(VMALLOC_VMADDR(addr), size, prot)) {
vfree(addr);
return NULL;
}
return addr;
}
void * vmalloc(unsigned long size)
{
return vmalloc_prot (size, PAGE_KERNEL);
}
int vread(char *buf, char *addr, int count)
{
struct vm_struct **p, *tmp;
char *vaddr, *buf_start = buf;
int n;
for (p = &vmlist; (tmp = *p) ; p = &tmp->next) {
vaddr = (char *) tmp->addr;
while (addr < vaddr) {
if (count == 0)
goto finished;
put_user('\0', buf);
buf++;
addr++;
count--;
}
n = tmp->size - PAGE_SIZE;
if (addr > vaddr)
n -= addr - vaddr;
while (--n >= 0) {
if (count == 0)
goto finished;
put_user(*addr, buf);
buf++;
addr++;
count--;
}
}
finished:
return buf - buf_start;
}
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