static pte_t * __init kernel_page_table(void)
{
pte_t *ptablep;
ptablep = (pte_t *)alloc_bootmem_low_pages(PAGE_SIZE);
clear_page(ptablep);
__flush_page_to_ram(ptablep);
flush_tlb_kernel_page(ptablep);
nocache_page(ptablep);
return ptablep;
}
static pmd_t * __init kernel_ptr_table(void)
{
if (!last_pgtable) {
unsigned long pmd, last;
int i;
/* Find the last ptr table that was used in head.S and
* reuse the remaining space in that page for further
* ptr tables.
*/
last = (unsigned long)kernel_pg_dir;
for (i = 0; i < PTRS_PER_PGD; i++) {
if (!pgd_present(kernel_pg_dir[i]))
continue;
pmd = __pgd_page(kernel_pg_dir[i]);
if (pmd > last)
last = pmd;
}
last_pgtable = (pmd_t *)last;
#ifdef DEBUG
printk("kernel_ptr_init: %p\n", last_pgtable);
#endif
}
last_pgtable += PTRS_PER_PMD;
if (((unsigned long)last_pgtable & ~PAGE_MASK) == 0) {
last_pgtable = (pmd_t *)alloc_bootmem_low_pages(PAGE_SIZE);
clear_page(last_pgtable);
__flush_page_to_ram(last_pgtable);
flush_tlb_kernel_page(last_pgtable);
nocache_page(last_pgtable);
}
return last_pgtable;
}
pmd_t *get_pointer_table (void)
{
pmd_t *pmdp = NULL;
unsigned long flags;
struct ptable_desc *dp = ptable_list.next;
int i;
/*
* For a pointer table for a user process address space, a
* table is taken from a page allocated for the purpose. Each
* page can hold 8 pointer tables. The page is remapped in
* virtual address space to be noncacheable.
*/
if (PD_NONEFREE (dp)) {
if (!(dp = kmalloc (sizeof(struct ptable_desc),GFP_KERNEL))) {
return 0;
}
if (!(dp->page = __get_free_page (GFP_KERNEL))) {
kfree (dp);
return 0;
}
nocache_page (dp->page);
dp->alloced = 0;
/* put at head of list */
save_flags(flags);
cli();
dp->next = ptable_list.next;
dp->prev = ptable_list.next->prev;
ptable_list.next->prev = dp;
ptable_list.next = dp;
restore_flags(flags);
}
for (i = 0; i < 8; i++)
if (PD_TABLEFREE (dp, i)) {
PD_MARKUSED (dp, i);
pmdp = (pmd_t *)(dp->page + PTABLE_SIZE*i);
break;
}
if (PD_NONEFREE (dp)) {
/* move to end of list */
save_flags(flags);
cli();
dp->prev->next = dp->next;
dp->next->prev = dp->prev;
dp->next = ptable_list.next->prev;
dp->prev = ptable_list.prev;
ptable_list.prev->next = dp;
ptable_list.prev = dp;
restore_flags(flags);
}
memset (pmdp, 0, PTABLE_SIZE);
return pmdp;
}
