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