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/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_PPC64
  27#define FIXADDR_TOP     (IOREMAP_END + FIXADDR_SIZE)
  28#else
  29#define FIXADDR_SIZE    0
  30#ifdef CONFIG_KASAN
  31#include <asm/kasan.h>
  32#define FIXADDR_TOP     (KASAN_SHADOW_START - PAGE_SIZE)
  33#else
  34#define FIXADDR_TOP     ((unsigned long)(-PAGE_SIZE))
  35#endif
  36#endif
  37
  38/*
  39 * Here we define all the compile-time 'special' virtual
  40 * addresses. The point is to have a constant address at
  41 * compile time, but to set the physical address only
  42 * in the boot process. We allocate these special addresses
  43 * from the end of virtual memory (0xfffff000) backwards.
  44 * Also this lets us do fail-safe vmalloc(), we
  45 * can guarantee that these special addresses and
  46 * vmalloc()-ed addresses never overlap.
  47 *
  48 * these 'compile-time allocated' memory buffers are
  49 * fixed-size 4k pages. (or larger if used with an increment
  50 * highger than 1) use fixmap_set(idx,phys) to associate
  51 * physical memory with fixmap indices.
  52 *
  53 * TLB entries of such buffers will not be flushed across
  54 * task switches.
  55 */
  56enum fixed_addresses {
  57        FIX_HOLE,
  58#ifdef CONFIG_PPC32
  59        /* reserve the top 128K for early debugging purposes */
  60        FIX_EARLY_DEBUG_TOP = FIX_HOLE,
  61        FIX_EARLY_DEBUG_BASE = FIX_EARLY_DEBUG_TOP+(ALIGN(SZ_128K, PAGE_SIZE)/PAGE_SIZE)-1,
  62#ifdef CONFIG_HIGHMEM
  63        FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
  64        FIX_KMAP_END = FIX_KMAP_BEGIN + (KM_MAX_IDX * NR_CPUS) - 1,
  65#endif
  66#ifdef CONFIG_PPC_8xx
  67        /* For IMMR we need an aligned 512K area */
  68#define FIX_IMMR_SIZE   (512 * 1024 / PAGE_SIZE)
  69        FIX_IMMR_START,
  70        FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
  71                       FIX_IMMR_SIZE,
  72#endif
  73#ifdef CONFIG_PPC_83xx
  74        /* For IMMR we need an aligned 2M area */
  75#define FIX_IMMR_SIZE   (SZ_2M / PAGE_SIZE)
  76        FIX_IMMR_START,
  77        FIX_IMMR_BASE = __ALIGN_MASK(FIX_IMMR_START, FIX_IMMR_SIZE - 1) - 1 +
  78                       FIX_IMMR_SIZE,
  79#endif
  80        /* FIX_PCIE_MCFG, */
  81#endif /* CONFIG_PPC32 */
  82        __end_of_permanent_fixed_addresses,
  83
  84#define NR_FIX_BTMAPS           (SZ_256K / PAGE_SIZE)
  85#define FIX_BTMAPS_SLOTS        16
  86#define TOTAL_FIX_BTMAPS        (NR_FIX_BTMAPS * FIX_BTMAPS_SLOTS)
  87
  88        FIX_BTMAP_END = __end_of_permanent_fixed_addresses,
  89        FIX_BTMAP_BEGIN = FIX_BTMAP_END + TOTAL_FIX_BTMAPS - 1,
  90        __end_of_fixed_addresses
  91};
  92
  93#define __FIXADDR_SIZE  (__end_of_fixed_addresses << PAGE_SHIFT)
  94#define FIXADDR_START           (FIXADDR_TOP - __FIXADDR_SIZE)
  95
  96#define FIXMAP_ALIGNED_SIZE     (ALIGN(FIXADDR_TOP, PGDIR_SIZE) - \
  97                                 ALIGN_DOWN(FIXADDR_START, PGDIR_SIZE))
  98#define FIXMAP_PTE_SIZE (FIXMAP_ALIGNED_SIZE / PGDIR_SIZE * PTE_TABLE_SIZE)
  99
 100#define FIXMAP_PAGE_NOCACHE PAGE_KERNEL_NCG
 101#define FIXMAP_PAGE_IO  PAGE_KERNEL_NCG
 102
 103#include <asm-generic/fixmap.h>
 104
 105static inline void __set_fixmap(enum fixed_addresses idx,
 106                                phys_addr_t phys, pgprot_t flags)
 107{
 108        BUILD_BUG_ON(IS_ENABLED(CONFIG_PPC64) && __FIXADDR_SIZE > FIXADDR_SIZE);
 109
 110        if (__builtin_constant_p(idx))
 111                BUILD_BUG_ON(idx >= __end_of_fixed_addresses);
 112        else if (WARN_ON(idx >= __end_of_fixed_addresses))
 113                return;
 114
 115        map_kernel_page(__fix_to_virt(idx), phys, flags);
 116}
 117
 118#define __early_set_fixmap      __set_fixmap
 119
 120#endif /* !__ASSEMBLY__ */
 121#endif
 122