LXR linux/arch/powerpc/include/asm/fixmap.h

   1/*
   2 * fixmap.h: compile-time virtual memory allocation
   3 *
   4 * This file is subject to the terms and conditions of the GNU General Public
   5 * License.  See the file "COPYING" in the main directory of this archive
   6 * for more details.
   7 *
   8 * Copyright (C) 1998 Ingo Molnar
   9 *
  10 * Copyright 2008 Freescale Semiconductor Inc.
  11 *   Port to powerpc added by Kumar Gala
  12 */
  13
  14#ifndef _ASM_FIXMAP_H
  15#define _ASM_FIXMAP_H
  16
  17#ifndef __ASSEMBLY__
  18#include <linux/kernel.h>
  19#include <asm/page.h>
  20#include <asm/pgtable.h>
  21#ifdef CONFIG_HIGHMEM
  22#include <linux/threads.h>
  23#include <asm/kmap_types.h>
  24#endif
  25
  26#define FIXADDR_TOP     ((unsigned long)(-PAGE_SIZE))
  27
  28/*
  29 * Here we define all the compile-time 'special' virtual
  30 * addresses. The point is to have a constant address at
  31 * compile time, but to set the physical address only
  32 * in the boot process. We allocate these special addresses
  33 * from the end of virtual memory (0xfffff000) backwards.
  34 * Also this lets us do fail-safe vmalloc(), we
  35 * can guarantee that these special addresses and
  36 * vmalloc()-ed addresses never overlap.
  37 *
  38 * these 'compile-time allocated' memory buffers are
  39 * fixed-size 4k pages. (or larger if used with an increment
  40 * highger than 1) use fixmap_set(idx,phys) to associate
  41 * physical memory with fixmap indices.
  42 *
  43 * TLB entries of such buffers will not be flushed across
  44 * task switches.
  45 */
  46enum fixed_addresses {
  47        FIX_HOLE,
  48        /* reserve the top 128K for early debugging purposes */
  49        FIX_EARLY_DEBUG_TOP = FIX_HOLE,
  50        FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+((128*1024)/PAGE_SIZE)-1,
  51#ifdef CONFIG_HIGHMEM
  52        FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
  53        FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
  54#endif
  55#ifdef CONFIG_PPC_8xx
  56        /* For IMMR we need an aligned 512K area */
  57#define FIX_IMMR_SIZE   (512 * 1024 / PAGE_SIZE)
  58        FIX_IMMR_START,
  59        FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
  60                       FIX_IMMR_SIZE,
  61#endif
  62        /* FIX_PCIE_MCFG, */
  63        __end_of_fixed_addresses
  64};
  65
  66#define __FIXADDR_SIZE  (__end_of_fixed_addresses << PAGE_SHIFT)
  67#define FIXADDR_START           (FIXADDR_TOP - __FIXADDR_SIZE)
  68
  69#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
  70
  71#include <asm-generic/fixmap.h>
  72
  73static inline void __set_fixmap(enum fixed_addresses idx,
  74                                phys_addr_t phys, pgprot_t flags)
  75{
  76        map_kernel_page(fix_to_virt(idx), phys, flags);
  77}
  78
  79#endif /* !__ASSEMBLY__ */
  80#endif
  81