LXR linux/arch/metag/include/asm/highmem.h

   1#ifndef _ASM_HIGHMEM_H
   2#define _ASM_HIGHMEM_H
   3
   4#include <asm/cacheflush.h>
   5#include <asm/kmap_types.h>
   6#include <asm/fixmap.h>
   7
   8/*
   9 * Right now we initialize only a single pte table. It can be extended
  10 * easily, subsequent pte tables have to be allocated in one physical
  11 * chunk of RAM.
  12 */
  13/*
  14 * Ordering is (from lower to higher memory addresses):
  15 *
  16 * high_memory
  17 *                      Persistent kmap area
  18 * PKMAP_BASE
  19 *                      fixed_addresses
  20 * FIXADDR_START
  21 * FIXADDR_TOP
  22 *                      Vmalloc area
  23 * VMALLOC_START
  24 * VMALLOC_END
  25 */
  26#define PKMAP_BASE              (FIXADDR_START - PMD_SIZE)
  27#define LAST_PKMAP              PTRS_PER_PTE
  28#define LAST_PKMAP_MASK         (LAST_PKMAP - 1)
  29#define PKMAP_NR(virt)          (((virt) - PKMAP_BASE) >> PAGE_SHIFT)
  30#define PKMAP_ADDR(nr)          (PKMAP_BASE + ((nr) << PAGE_SHIFT))
  31
  32#define kmap_prot               PAGE_KERNEL
  33
  34static inline void flush_cache_kmaps(void)
  35{
  36        flush_cache_all();
  37}
  38
  39/* declarations for highmem.c */
  40extern unsigned long highstart_pfn, highend_pfn;
  41
  42extern pte_t *pkmap_page_table;
  43
  44extern void *kmap_high(struct page *page);
  45extern void kunmap_high(struct page *page);
  46
  47extern void kmap_init(void);
  48
  49/*
  50 * The following functions are already defined by <linux/highmem.h>
  51 * when CONFIG_HIGHMEM is not set.
  52 */
  53#ifdef CONFIG_HIGHMEM
  54extern void *kmap(struct page *page);
  55extern void kunmap(struct page *page);
  56extern void *kmap_atomic(struct page *page);
  57extern void __kunmap_atomic(void *kvaddr);
  58extern void *kmap_atomic_pfn(unsigned long pfn);
  59extern struct page *kmap_atomic_to_page(void *ptr);
  60#endif
  61
  62#endif
  63