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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 */
51enum 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
98static 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