Viewing file:  kmap.c (3.09 KB) -rw-r--r--
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/*
** Stolen mostly from arch/parisc/kernel/pci-dma.c
*/
#include <linux/types.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <linux/pci.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <asm/uaccess.h>
#include <asm/pgalloc.h>
#include <asm/io.h>
#include <asm/page.h> /* get_order */
#undef flush_cache_all
#define flush_cache_all flush_all_caches
typedef void (*pte_iterator_t) (pte_t * pte, unsigned long arg);
#if 0
/* XXX This routine could be used with iterate_page() to replace
* unmap_uncached_page() and save a little code space but I didn't
* do that since I'm not certain whether this is the right path. -PB
*/
static void unmap_cached_pte(pte_t * pte, unsigned long arg)
{
pte_t page = *pte;
pte_clear(pte);
if (!pte_none(page)) {
if (pte_present(page)) {
unsigned long map_nr = pte_pagenr(page);
if (map_nr < max_mapnr)
__free_page(mem_map + map_nr);
} else {
printk(KERN_CRIT
"Whee.. Swapped out page in kernel page table\n");
}
}
}
#endif
/* These two routines should probably check a few things... */
static void set_uncached(pte_t * pte, unsigned long arg)
{
pte_val(*pte) |= _PAGE_NO_CACHE;
}
static void set_cached(pte_t * pte, unsigned long arg)
{
pte_val(*pte) &= ~_PAGE_NO_CACHE;
}
static inline void iterate_pte(pmd_t * pmd, unsigned long address,
unsigned long size, pte_iterator_t op,
unsigned long arg)
{
pte_t *pte;
unsigned long end;
if (pmd_none(*pmd))
return;
if (pmd_bad(*pmd)) {
pmd_ERROR(*pmd);
pmd_clear(pmd);
return;
}
pte = pte_offset(pmd, address);
address &= ~PMD_MASK;
end = address + size;
if (end > PMD_SIZE)
end = PMD_SIZE;
do {
op(pte, arg);
address += PAGE_SIZE;
pte++;
} while (address < end);
}
static inline void iterate_pmd(pgd_t * dir, unsigned long address,
unsigned long size, pte_iterator_t op,
unsigned long arg)
{
pmd_t *pmd;
unsigned long end;
if (pgd_none(*dir))
return;
if (pgd_bad(*dir)) {
pgd_ERROR(*dir);
pgd_clear(dir);
return;
}
pmd = pmd_offset(dir, address);
address &= ~PGDIR_MASK;
end = address + size;
if (end > PGDIR_SIZE)
end = PGDIR_SIZE;
do {
iterate_pte(pmd, address, end - address, op, arg);
address = (address + PMD_SIZE) & PMD_MASK;
pmd++;
} while (address < end);
}
static void iterate_pages(unsigned long address, unsigned long size,
pte_iterator_t op, unsigned long arg)
{
pgd_t *dir;
unsigned long end = address + size;
dir = pgd_offset_k(address);
flush_cache_all();
do {
iterate_pmd(dir, address, end - address, op, arg);
address = (address + PGDIR_SIZE) & PGDIR_MASK;
dir++;
} while (address && (address < end));
flush_tlb_all();
}
void
kernel_set_cachemode(unsigned long vaddr, unsigned long size, int what)
{
switch (what) {
case IOMAP_FULL_CACHING:
iterate_pages(vaddr, size, set_cached, 0);
flush_tlb_range(&init_mm, vaddr, size);
break;
case IOMAP_NOCACHE_SER:
iterate_pages(vaddr, size, set_uncached, 0);
flush_tlb_range(&init_mm, vaddr, size);
break;
default:
printk(KERN_CRIT
"kernel_set_cachemode mode %d not understood\n",
what);
break;
}
}
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