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/sizes.h>
  19 #include <linux/pgtable.h>
  20 #include <asm/page.h>
  21 #ifdef CONFIG_HIGHMEM
  22 #include <linux/threads.h>
  23 #include <asm/kmap_size.h>
  24 #endif
  25
  26 #ifdef CONFIG_KASAN
  27 #include <asm/kasan.h>
  28 #define FIXADDR_TOP     (KASAN_SHADOW_START - PAGE_SIZE)
  29 #else
  30 #define FIXADDR_TOP     ((unsigned long)(-PAGE_SIZE))
  31 #endif
  32
  33 /*
  34  * Here we define all the compile-time 'special' virtual
  35  * addresses. The point is to have a constant address at
  36  * compile time, but to set the physical address only
  37  * in the boot process. We allocate these special addresses
  38  * from the end of virtual memory (0xfffff000) backwards.
  39  * Also this lets us do fail-safe vmalloc(), we
  40  * can guarantee that these special addresses and
  41  * vmalloc()-ed addresses never overlap.
  42  *
  43  * these 'compile-time allocated' memory buffers are
  44  * fixed-size 4k pages. (or larger if used with an increment
  45  * highger than 1) use fixmap_set(idx,phys) to associate
  46  * physical memory with fixmap indices.
  47  *
  48  * TLB entries of such buffers will not be flushed across
  49  * task switches.
  50  */
  51 enum fixed_addresses {
  52         FIX_HOLE,
  53         /* reserve the top 128K for early debugging purposes */
  54         FIX_EARLY_DEBUG_TOP = FIX_HOLE,
  55         FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+(ALIGN(SZ_128K, PAGE_SIZE)/PAGE_SIZE)-1,
  56 #ifdef CONFIG_HIGHMEM
  57         FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
  58         FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
  59 #endif
  60 #ifdef CONFIG_PPC_8xx
  61         /* For IMMR we need an aligned 512K area */
  62 #define FIX_IMMR_SIZE   (512 * 1024 / PAGE_SIZE)
  63         FIX_IMMR_START,
  64         FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
  65                        FIX_IMMR_SIZE,
  66 #endif
  67 #ifdef CONFIG_PPC_83xx
  68         /* For IMMR we need an aligned 2M area */
  69 #define FIX_IMMR_SIZE   (SZ_2M / PAGE_SIZE)
  70         FIX_IMMR_START,
  71         FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
  72                        FIX_IMMR_SIZE,
  73 #endif
  74         /* FIX_PCIE_MCFG, */
  75         __end_of_permanent_fixed_addresses,
  76
  77 #define NR_FIX_BTMAPS           (SZ_256K / PAGE_SIZE)
  78 #define FIX_BTMAPS_SLOTS        16
  79 #define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
  80
  81         FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
  82         FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
  83         __end_of_fixed_addresses
  84 };
  85
  86 #define __FIXADDR_SIZE  (__end_of_fixed_addresses << PAGE_SHIFT)
  87 #define FIXADDR_START           (FIXADDR_TOP - __FIXADDR_SIZE)
  88
  89 #define FIXMAP_ALIGNED_SIZE     (ALIGN(FIXADDR_TOP, PGDIR_SIZE) - \
  90                                  ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE))
  91 #define FIXMAP_PTE_SIZE (FIXMAP_ALIGNED_SIZE / PGDIR_SIZE * PTE_TABLE_SIZE)
  92
  93 #define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
  94 #define FIXMAP_PAGE_IO  PAGE_KERNEL_NCG
  95
  96 #include <asm-generic/fixmap.h>
  97
  98 static inline void __set_fixmap(enum fixed_addresses idx,
  99                                 phys_addr_t phys, pgprot_t flags)
 100 {
 101         if (__builtin_constant_p(idx))
 102                 BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
 103         else if (WARN_ON(idx >= __end_of_fixed_addresses))
 104                 return;
 105
 106         map_kernel_page(__fix_to_virt(idx), phys, flags);
 107 }
 108
 109 #define __early_set_fixmap      __set_fixmap
 110
 111 #endif /* !__ASSEMBLY__ */
 112 #endif