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  */
  46 enum 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
  73 static 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, pgprot_val(flags));
  77 }
  78
  79 #endif /* !__ASSEMBLY__ */
  80 #endif