1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * Provide common bits of early_ioremap() support for architectures needing |
4 | * temporary mappings during boot before ioremap() is available. |
5 | * |
6 | * This is mostly a direct copy of the x86 early_ioremap implementation. |
7 | * |
8 | * (C) Copyright 1995 1996, 2014 Linus Torvalds |
9 | * |
10 | */ |
11 | #include <linux/kernel.h> |
12 | #include <linux/init.h> |
13 | #include <linux/io.h> |
14 | #include <linux/module.h> |
15 | #include <linux/slab.h> |
16 | #include <linux/mm.h> |
17 | #include <linux/vmalloc.h> |
18 | #include <asm/fixmap.h> |
19 | #include <asm/early_ioremap.h> |
20 | |
21 | #ifdef CONFIG_MMU |
22 | static int early_ioremap_debug __initdata; |
23 | |
24 | static int __init early_ioremap_debug_setup(char *str) |
25 | { |
26 | early_ioremap_debug = 1; |
27 | |
28 | return 0; |
29 | } |
30 | early_param("early_ioremap_debug" , early_ioremap_debug_setup); |
31 | |
32 | static int after_paging_init __initdata; |
33 | |
34 | pgprot_t __init __weak early_memremap_pgprot_adjust(resource_size_t phys_addr, |
35 | unsigned long size, |
36 | pgprot_t prot) |
37 | { |
38 | return prot; |
39 | } |
40 | |
41 | void __init __weak early_ioremap_shutdown(void) |
42 | { |
43 | } |
44 | |
45 | void __init early_ioremap_reset(void) |
46 | { |
47 | early_ioremap_shutdown(); |
48 | after_paging_init = 1; |
49 | } |
50 | |
51 | /* |
52 | * Generally, ioremap() is available after paging_init() has been called. |
53 | * Architectures wanting to allow early_ioremap after paging_init() can |
54 | * define __late_set_fixmap and __late_clear_fixmap to do the right thing. |
55 | */ |
56 | #ifndef __late_set_fixmap |
57 | static inline void __init __late_set_fixmap(enum fixed_addresses idx, |
58 | phys_addr_t phys, pgprot_t prot) |
59 | { |
60 | BUG(); |
61 | } |
62 | #endif |
63 | |
64 | #ifndef __late_clear_fixmap |
65 | static inline void __init __late_clear_fixmap(enum fixed_addresses idx) |
66 | { |
67 | BUG(); |
68 | } |
69 | #endif |
70 | |
71 | static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata; |
72 | static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata; |
73 | static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata; |
74 | |
75 | void __init early_ioremap_setup(void) |
76 | { |
77 | int i; |
78 | |
79 | for (i = 0; i < FIX_BTMAPS_SLOTS; i++) |
80 | if (WARN_ON(prev_map[i])) |
81 | break; |
82 | |
83 | for (i = 0; i < FIX_BTMAPS_SLOTS; i++) |
84 | slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i); |
85 | } |
86 | |
87 | static int __init check_early_ioremap_leak(void) |
88 | { |
89 | int count = 0; |
90 | int i; |
91 | |
92 | for (i = 0; i < FIX_BTMAPS_SLOTS; i++) |
93 | if (prev_map[i]) |
94 | count++; |
95 | |
96 | if (WARN(count, KERN_WARNING |
97 | "Debug warning: early ioremap leak of %d areas detected.\n" |
98 | "please boot with early_ioremap_debug and report the dmesg.\n" , |
99 | count)) |
100 | return 1; |
101 | return 0; |
102 | } |
103 | late_initcall(check_early_ioremap_leak); |
104 | |
105 | static void __init __iomem * |
106 | __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot) |
107 | { |
108 | unsigned long offset; |
109 | resource_size_t last_addr; |
110 | unsigned int nrpages; |
111 | enum fixed_addresses idx; |
112 | int i, slot; |
113 | |
114 | WARN_ON(system_state >= SYSTEM_RUNNING); |
115 | |
116 | slot = -1; |
117 | for (i = 0; i < FIX_BTMAPS_SLOTS; i++) { |
118 | if (!prev_map[i]) { |
119 | slot = i; |
120 | break; |
121 | } |
122 | } |
123 | |
124 | if (WARN(slot < 0, "%s(%08llx, %08lx) not found slot\n" , |
125 | __func__, (u64)phys_addr, size)) |
126 | return NULL; |
127 | |
128 | /* Don't allow wraparound or zero size */ |
129 | last_addr = phys_addr + size - 1; |
130 | if (WARN_ON(!size || last_addr < phys_addr)) |
131 | return NULL; |
132 | |
133 | prev_size[slot] = size; |
134 | /* |
135 | * Mappings have to be page-aligned |
136 | */ |
137 | offset = offset_in_page(phys_addr); |
138 | phys_addr &= PAGE_MASK; |
139 | size = PAGE_ALIGN(last_addr + 1) - phys_addr; |
140 | |
141 | /* |
142 | * Mappings have to fit in the FIX_BTMAP area. |
143 | */ |
144 | nrpages = size >> PAGE_SHIFT; |
145 | if (WARN_ON(nrpages > NR_FIX_BTMAPS)) |
146 | return NULL; |
147 | |
148 | /* |
149 | * Ok, go for it.. |
150 | */ |
151 | idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot; |
152 | while (nrpages > 0) { |
153 | if (after_paging_init) |
154 | __late_set_fixmap(idx, phys_addr, prot); |
155 | else |
156 | __early_set_fixmap(idx, phys_addr, prot); |
157 | phys_addr += PAGE_SIZE; |
158 | --idx; |
159 | --nrpages; |
160 | } |
161 | WARN(early_ioremap_debug, "%s(%08llx, %08lx) [%d] => %08lx + %08lx\n" , |
162 | __func__, (u64)phys_addr, size, slot, offset, slot_virt[slot]); |
163 | |
164 | prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]); |
165 | return prev_map[slot]; |
166 | } |
167 | |
168 | void __init early_iounmap(void __iomem *addr, unsigned long size) |
169 | { |
170 | unsigned long virt_addr; |
171 | unsigned long offset; |
172 | unsigned int nrpages; |
173 | enum fixed_addresses idx; |
174 | int i, slot; |
175 | |
176 | slot = -1; |
177 | for (i = 0; i < FIX_BTMAPS_SLOTS; i++) { |
178 | if (prev_map[i] == addr) { |
179 | slot = i; |
180 | break; |
181 | } |
182 | } |
183 | |
184 | if (WARN(slot < 0, "early_iounmap(%p, %08lx) not found slot\n" , |
185 | addr, size)) |
186 | return; |
187 | |
188 | if (WARN(prev_size[slot] != size, |
189 | "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n" , |
190 | addr, size, slot, prev_size[slot])) |
191 | return; |
192 | |
193 | WARN(early_ioremap_debug, "early_iounmap(%p, %08lx) [%d]\n" , |
194 | addr, size, slot); |
195 | |
196 | virt_addr = (unsigned long)addr; |
197 | if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN))) |
198 | return; |
199 | |
200 | offset = offset_in_page(virt_addr); |
201 | nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT; |
202 | |
203 | idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot; |
204 | while (nrpages > 0) { |
205 | if (after_paging_init) |
206 | __late_clear_fixmap(idx); |
207 | else |
208 | __early_set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR); |
209 | --idx; |
210 | --nrpages; |
211 | } |
212 | prev_map[slot] = NULL; |
213 | } |
214 | |
215 | /* Remap an IO device */ |
216 | void __init __iomem * |
217 | early_ioremap(resource_size_t phys_addr, unsigned long size) |
218 | { |
219 | return __early_ioremap(phys_addr, size, FIXMAP_PAGE_IO); |
220 | } |
221 | |
222 | /* Remap memory */ |
223 | void __init * |
224 | early_memremap(resource_size_t phys_addr, unsigned long size) |
225 | { |
226 | pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size, |
227 | FIXMAP_PAGE_NORMAL); |
228 | |
229 | return (__force void *)__early_ioremap(phys_addr, size, prot); |
230 | } |
231 | #ifdef FIXMAP_PAGE_RO |
232 | void __init * |
233 | early_memremap_ro(resource_size_t phys_addr, unsigned long size) |
234 | { |
235 | pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size, |
236 | FIXMAP_PAGE_RO); |
237 | |
238 | return (__force void *)__early_ioremap(phys_addr, size, prot); |
239 | } |
240 | #endif |
241 | |
242 | #ifdef CONFIG_ARCH_USE_MEMREMAP_PROT |
243 | void __init * |
244 | early_memremap_prot(resource_size_t phys_addr, unsigned long size, |
245 | unsigned long prot_val) |
246 | { |
247 | return (__force void *)__early_ioremap(phys_addr, size, |
248 | __pgprot(prot_val)); |
249 | } |
250 | #endif |
251 | |
252 | #define MAX_MAP_CHUNK (NR_FIX_BTMAPS << PAGE_SHIFT) |
253 | |
254 | void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size) |
255 | { |
256 | unsigned long slop, clen; |
257 | char *p; |
258 | |
259 | while (size) { |
260 | slop = offset_in_page(src); |
261 | clen = size; |
262 | if (clen > MAX_MAP_CHUNK - slop) |
263 | clen = MAX_MAP_CHUNK - slop; |
264 | p = early_memremap(src & PAGE_MASK, clen + slop); |
265 | memcpy(dest, p + slop, clen); |
266 | early_memunmap(p, clen + slop); |
267 | dest += clen; |
268 | src += clen; |
269 | size -= clen; |
270 | } |
271 | } |
272 | |
273 | #else /* CONFIG_MMU */ |
274 | |
275 | void __init __iomem * |
276 | early_ioremap(resource_size_t phys_addr, unsigned long size) |
277 | { |
278 | return (__force void __iomem *)phys_addr; |
279 | } |
280 | |
281 | /* Remap memory */ |
282 | void __init * |
283 | early_memremap(resource_size_t phys_addr, unsigned long size) |
284 | { |
285 | return (void *)phys_addr; |
286 | } |
287 | void __init * |
288 | early_memremap_ro(resource_size_t phys_addr, unsigned long size) |
289 | { |
290 | return (void *)phys_addr; |
291 | } |
292 | |
293 | void __init early_iounmap(void __iomem *addr, unsigned long size) |
294 | { |
295 | } |
296 | |
297 | #endif /* CONFIG_MMU */ |
298 | |
299 | |
300 | void __init early_memunmap(void *addr, unsigned long size) |
301 | { |
302 | early_iounmap((__force void __iomem *)addr, size); |
303 | } |
304 | |