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