/*
* 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
*/
#include <linux/malloc.h>
#include <linux/vmalloc.h>
#include <linux/spinlock.h>
#include <linux/smp_lock.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
rwlock_t vmlist_lock = RW_LOCK_UNLOCKED;
struct vm_struct * vmlist;
20 static inline void free_area_pte(pmd_t * pmd, unsigned long address, unsigned long size)
{
pte_t * pte;
unsigned long end;
25 if (pmd_none(*pmd))
26 return;
27 if (pmd_bad(*pmd)) {
pmd_ERROR(*pmd);
29 pmd_clear(pmd);
30 return;
}
pte = pte_offset(pmd, address);
address &= ~PMD_MASK;
end = address + size;
35 if (end > PMD_SIZE)
end = PMD_SIZE;
37 do {
pte_t page;
page = ptep_get_and_clear(pte);
address += PAGE_SIZE;
pte++;
42 if (pte_none(page))
43 continue;
44 if (pte_present(page)) {
struct page *ptpage = pte_page(page);
46 if (VALID_PAGE(ptpage) && (!PageReserved(ptpage)))
__free_page(ptpage);
48 continue;
}
printk(KERN_CRIT "Whee.. Swapped out page in kernel page table\n");
51 } while (address < end);
}
54 static inline void free_area_pmd(pgd_t * dir, unsigned long address, unsigned long size)
{
pmd_t * pmd;
unsigned long end;
59 if (pgd_none(*dir))
60 return;
61 if (pgd_bad(*dir)) {
pgd_ERROR(*dir);
63 pgd_clear(dir);
64 return;
}
pmd = pmd_offset(dir, address);
address &= ~PGDIR_MASK;
end = address + size;
69 if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
71 do {
free_area_pte(pmd, address, end - address);
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
75 } while (address < end);
}
78 void vmfree_area_pages(unsigned long address, unsigned long size)
{
pgd_t * dir;
unsigned long end = address + size;
dir = pgd_offset_k(address);
84 flush_cache_all();
85 do {
free_area_pmd(dir, address, end - address);
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
89 } while (address && (address < end));
90 flush_tlb_all();
}
93 static inline int alloc_area_pte (pte_t * pte, unsigned long address,
unsigned long size, int gfp_mask, pgprot_t prot)
{
unsigned long end;
address &= ~PMD_MASK;
end = address + size;
100 if (end > PMD_SIZE)
end = PMD_SIZE;
102 do {
struct page * page;
104 if (!pte_none(*pte))
printk(KERN_ERR "alloc_area_pte: page already exists\n");
page = alloc_page(gfp_mask);
107 if (!page)
108 return -ENOMEM;
set_pte(pte, mk_pte(page, prot));
address += PAGE_SIZE;
pte++;
112 } while (address < end);
113 return 0;
}
116 static inline int alloc_area_pmd(pmd_t * pmd, unsigned long address, unsigned long size, int gfp_mask, pgprot_t prot)
{
unsigned long end;
address &= ~PGDIR_MASK;
end = address + size;
122 if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
124 do {
pte_t * pte = pte_alloc_kernel(pmd, address);
126 if (!pte)
127 return -ENOMEM;
128 if (alloc_area_pte(pte, address, end - address, gfp_mask, prot))
129 return -ENOMEM;
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
132 } while (address < end);
133 return 0;
}
136 inline int vmalloc_area_pages (unsigned long address, unsigned long size,
int gfp_mask, pgprot_t prot)
{
pgd_t * dir;
unsigned long end = address + size;
int ret;
dir = pgd_offset_k(address);
144 flush_cache_all();
145 lock_kernel();
146 do {
pmd_t *pmd;
pmd = pmd_alloc_kernel(dir, address);
ret = -ENOMEM;
151 if (!pmd)
152 break;
ret = -ENOMEM;
155 if (alloc_area_pmd(pmd, address, end - address, gfp_mask, prot))
156 break;
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
ret = 0;
162 } while (address && (address < end));
163 unlock_kernel();
164 flush_tlb_all();
165 return ret;
}
168 struct vm_struct * get_vm_area(unsigned long size, unsigned long flags)
{
unsigned long addr;
struct vm_struct **p, *tmp, *area;
area = (struct vm_struct *) kmalloc(sizeof(*area), GFP_KERNEL);
174 if (!area)
175 return NULL;
size += PAGE_SIZE;
addr = VMALLOC_START;
write_lock(&vmlist_lock);
179 for (p = &vmlist; (tmp = *p) ; p = &tmp->next) {
180 if ((size + addr) < addr) {
181 write_unlock(&vmlist_lock);
kfree(area);
183 return NULL;
}
185 if (size + addr < (unsigned long) tmp->addr)
186 break;
addr = tmp->size + (unsigned long) tmp->addr;
188 if (addr > VMALLOC_END-size) {
189 write_unlock(&vmlist_lock);
kfree(area);
191 return NULL;
}
}
area->flags = flags;
area->addr = (void *)addr;
area->size = size;
area->next = *p;
*p = area;
199 write_unlock(&vmlist_lock);
200 return area;
}
203 void vfree(void * addr)
{
struct vm_struct **p, *tmp;
207 if (!addr)
208 return;
209 if ((PAGE_SIZE-1) & (unsigned long) addr) {
printk(KERN_ERR "Trying to vfree() bad address (%p)\n", addr);
211 return;
}
write_lock(&vmlist_lock);
214 for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) {
215 if (tmp->addr == addr) {
*p = tmp->next;
vmfree_area_pages(VMALLOC_VMADDR(tmp->addr), tmp->size);
218 write_unlock(&vmlist_lock);
kfree(tmp);
220 return;
}
}
223 write_unlock(&vmlist_lock);
printk(KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", addr);
}
227 void * __vmalloc (unsigned long size, int gfp_mask, pgprot_t prot)
{
void * addr;
struct vm_struct *area;
size = PAGE_ALIGN(size);
233 if (!size || (size >> PAGE_SHIFT) > num_physpages) {
234 BUG();
235 return NULL;
}
area = get_vm_area(size, VM_ALLOC);
238 if (!area)
239 return NULL;
addr = area->addr;
241 if (vmalloc_area_pages(VMALLOC_VMADDR(addr), size, gfp_mask, prot)) {
vfree(addr);
243 return NULL;
}
245 return addr;
}
248 long vread(char *buf, char *addr, unsigned long count)
{
struct vm_struct *tmp;
char *vaddr, *buf_start = buf;
unsigned long n;
/* Don't allow overflow */
255 if ((unsigned long) addr + count < count)
count = -(unsigned long) addr;
read_lock(&vmlist_lock);
259 for (tmp = vmlist; tmp; tmp = tmp->next) {
vaddr = (char *) tmp->addr;
261 if (addr >= vaddr + tmp->size - PAGE_SIZE)
262 continue;
263 while (addr < vaddr) {
264 if (count == 0)
265 goto finished;
*buf = '\0';
buf++;
addr++;
count--;
}
n = vaddr + tmp->size - PAGE_SIZE - addr;
272 do {
273 if (count == 0)
274 goto finished;
*buf = *addr;
buf++;
addr++;
count--;
279 } while (--n > 0);
}
finished:
282 read_unlock(&vmlist_lock);
283 return buf - buf_start;
}