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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
4d35b93a MF |
2 | /* |
3 | * Re-map IO memory to kernel address space so that we can access it. | |
4 | * | |
5 | * These functions should only be used when it is necessary to map a | |
6 | * physical address space into the kernel address space before ioremap() | |
7 | * can be used, e.g. early in boot before paging_init(). | |
8 | * | |
9 | * Copyright (C) 2009 Matt Fleming | |
10 | */ | |
11 | ||
12 | #include <linux/vmalloc.h> | |
13 | #include <linux/ioport.h> | |
14 | #include <linux/module.h> | |
15 | #include <linux/mm.h> | |
16 | #include <linux/io.h> | |
57c8a661 | 17 | #include <linux/memblock.h> |
4d35b93a | 18 | #include <linux/proc_fs.h> |
4d35b93a MF |
19 | #include <asm/fixmap.h> |
20 | #include <asm/page.h> | |
21 | #include <asm/pgalloc.h> | |
22 | #include <asm/addrspace.h> | |
23 | #include <asm/cacheflush.h> | |
24 | #include <asm/tlbflush.h> | |
25 | #include <asm/mmu.h> | |
26 | #include <asm/mmu_context.h> | |
27 | ||
28 | struct ioremap_map { | |
29 | void __iomem *addr; | |
30 | unsigned long size; | |
31 | unsigned long fixmap_addr; | |
32 | }; | |
33 | ||
34 | static struct ioremap_map ioremap_maps[FIX_N_IOREMAPS]; | |
35 | ||
36 | void __init ioremap_fixed_init(void) | |
37 | { | |
38 | struct ioremap_map *map; | |
39 | int i; | |
40 | ||
41 | for (i = 0; i < FIX_N_IOREMAPS; i++) { | |
42 | map = &ioremap_maps[i]; | |
43 | map->fixmap_addr = __fix_to_virt(FIX_IOREMAP_BEGIN + i); | |
44 | } | |
45 | } | |
46 | ||
47 | void __init __iomem * | |
90e7d649 | 48 | ioremap_fixed(phys_addr_t phys_addr, unsigned long size, pgprot_t prot) |
4d35b93a MF |
49 | { |
50 | enum fixed_addresses idx0, idx; | |
4d35b93a | 51 | struct ioremap_map *map; |
4d35b93a | 52 | unsigned int nrpages; |
90e7d649 | 53 | unsigned long offset; |
4d35b93a MF |
54 | int i, slot; |
55 | ||
90e7d649 PM |
56 | /* |
57 | * Mappings have to be page-aligned | |
58 | */ | |
59 | offset = phys_addr & ~PAGE_MASK; | |
60 | phys_addr &= PAGE_MASK; | |
61 | size = PAGE_ALIGN(phys_addr + size) - phys_addr; | |
62 | ||
4d35b93a MF |
63 | slot = -1; |
64 | for (i = 0; i < FIX_N_IOREMAPS; i++) { | |
65 | map = &ioremap_maps[i]; | |
66 | if (!map->addr) { | |
67 | map->size = size; | |
68 | slot = i; | |
69 | break; | |
70 | } | |
71 | } | |
72 | ||
73 | if (slot < 0) | |
74 | return NULL; | |
75 | ||
4d35b93a MF |
76 | /* |
77 | * Mappings have to fit in the FIX_IOREMAP area. | |
78 | */ | |
79 | nrpages = size >> PAGE_SHIFT; | |
80 | if (nrpages > FIX_N_IOREMAPS) | |
81 | return NULL; | |
82 | ||
83 | /* | |
84 | * Ok, go for it.. | |
85 | */ | |
86 | idx0 = FIX_IOREMAP_BEGIN + slot; | |
87 | idx = idx0; | |
88 | while (nrpages > 0) { | |
89 | pgprot_val(prot) |= _PAGE_WIRED; | |
90 | __set_fixmap(idx, phys_addr, prot); | |
91 | phys_addr += PAGE_SIZE; | |
92 | idx++; | |
93 | --nrpages; | |
94 | } | |
95 | ||
96 | map->addr = (void __iomem *)(offset + map->fixmap_addr); | |
97 | return map->addr; | |
98 | } | |
99 | ||
4f744aff | 100 | int iounmap_fixed(void __iomem *addr) |
4d35b93a MF |
101 | { |
102 | enum fixed_addresses idx; | |
4d35b93a | 103 | struct ioremap_map *map; |
4d35b93a MF |
104 | unsigned int nrpages; |
105 | int i, slot; | |
4d35b93a MF |
106 | |
107 | slot = -1; | |
108 | for (i = 0; i < FIX_N_IOREMAPS; i++) { | |
109 | map = &ioremap_maps[i]; | |
110 | if (map->addr == addr) { | |
111 | slot = i; | |
112 | break; | |
113 | } | |
114 | } | |
115 | ||
4f744aff PM |
116 | /* |
117 | * If we don't match, it's not for us. | |
118 | */ | |
4d35b93a | 119 | if (slot < 0) |
4f744aff | 120 | return -EINVAL; |
4d35b93a | 121 | |
920efaab | 122 | nrpages = map->size >> PAGE_SHIFT; |
4d35b93a | 123 | |
920efaab | 124 | idx = FIX_IOREMAP_BEGIN + slot + nrpages - 1; |
4d35b93a | 125 | while (nrpages > 0) { |
acf2c968 | 126 | __clear_fixmap(idx, __pgprot(_PAGE_WIRED)); |
4d35b93a MF |
127 | --idx; |
128 | --nrpages; | |
129 | } | |
130 | ||
131 | map->size = 0; | |
132 | map->addr = NULL; | |
4f744aff PM |
133 | |
134 | return 0; | |
4d35b93a | 135 | } |