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_types.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_TYPE_NR*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
__set_fixmap(enum fixed_addresses idx,phys_addr_t phys,pgprot_t flags)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
113
