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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
23static int early_ioremap_debug __initdata;
24
25static int __init early_ioremap_debug_setup(char *str)
26{
27 early_ioremap_debug = 1;
28
29 return 0;
30}
31early_param("early_ioremap_debug", early_ioremap_debug_setup);
32
33#define early_ioremap_dbg(fmt, args...) \
34 do { \
35 if (unlikely(early_ioremap_debug)) { \
36 pr_warn(fmt, ##args); \
37 dump_stack(); \
38 } \
39 } while (0)
40
41static int after_paging_init __initdata;
42
43pgprot_t __init __weak early_memremap_pgprot_adjust(resource_size_t phys_addr,
44 unsigned long size,
45 pgprot_t prot)
46{
47 return prot;
48}
49
50/*
51 * Only architectures whose early_ioremap() must stop using __early_set_fixmap()
52 * after paging_init() need to call this.
53 */
54void __init early_ioremap_reset(void)
55{
56 after_paging_init = 1;
57}
58
59/*
60 * Only architectures that call early_ioremap_reset() need to define
61 * __late_set_fixmap() and __late_clear_fixmap(), which early_ioremap() uses
62 * instead of __early_set_fixmap() after the reset.
63 */
64#ifndef __late_set_fixmap
65static inline void __init __late_set_fixmap(enum fixed_addresses idx,
66 phys_addr_t phys, pgprot_t prot)
67{
68 BUG();
69}
70#endif
71
72#ifndef __late_clear_fixmap
73static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
74{
75 BUG();
76}
77#endif
78
79static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
80static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
81static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
82
83void __init early_ioremap_setup(void)
84{
85 int i;
86
87 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
88 WARN_ON_ONCE(prev_map[i]);
89 slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
90 }
91}
92
93static int __init check_early_ioremap_leak(void)
94{
95 int count = 0;
96 int i;
97
98 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
99 if (prev_map[i])
100 count++;
101
102 if (WARN(count, KERN_WARNING
103 "Debug warning: early ioremap leak of %d areas detected.\n"
104 "please boot with early_ioremap_debug and report the dmesg.\n",
105 count))
106 return 1;
107 return 0;
108}
109late_initcall(check_early_ioremap_leak);
110
111static void __init __iomem *
112__early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
113{
114 unsigned long offset;
115 resource_size_t last_addr;
116 unsigned int nrpages;
117 enum fixed_addresses idx;
118 int i, slot;
119
120 WARN_ON(system_state >= SYSTEM_RUNNING);
121
122 slot = -1;
123 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
124 if (!prev_map[i]) {
125 slot = i;
126 break;
127 }
128 }
129
130 if (WARN(slot < 0, "%s(%pa, %08lx) not found slot\n",
131 __func__, &phys_addr, size))
132 return NULL;
133
134 /* Don't allow wraparound or zero size */
135 last_addr = phys_addr + size - 1;
136 if (WARN_ON(!size || last_addr < phys_addr))
137 return NULL;
138
139 prev_size[slot] = size;
140 /*
141 * Mappings have to be page-aligned
142 */
143 offset = offset_in_page(phys_addr);
144 phys_addr &= PAGE_MASK;
145 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
146
147 /*
148 * Mappings have to fit in the FIX_BTMAP area.
149 */
150 nrpages = size >> PAGE_SHIFT;
151 if (WARN_ON(nrpages > NR_FIX_BTMAPS))
152 return NULL;
153
154 early_ioremap_dbg("%s(%pa, %08lx) [%d] => %08lx + %08lx\n",
155 __func__, &phys_addr, size, slot, slot_virt[slot], offset);
156
157 /*
158 * Ok, go for it..
159 */
160 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
161 while (nrpages > 0) {
162 if (after_paging_init)
163 __late_set_fixmap(idx, phys_addr, prot);
164 else
165 __early_set_fixmap(idx, phys_addr, prot);
166 phys_addr += PAGE_SIZE;
167 --idx;
168 --nrpages;
169 }
170
171 prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
172 return prev_map[slot];
173}
174
175void __init early_iounmap(void __iomem *addr, unsigned long size)
176{
177 unsigned long virt_addr;
178 unsigned long offset;
179 unsigned int nrpages;
180 enum fixed_addresses idx;
181 int i, slot;
182
183 slot = -1;
184 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
185 if (prev_map[i] == addr) {
186 slot = i;
187 break;
188 }
189 }
190
191 if (WARN(slot < 0, "%s(%p, %08lx) not found slot\n",
192 __func__, addr, size))
193 return;
194
195 if (WARN(prev_size[slot] != size,
196 "%s(%p, %08lx) [%d] size not consistent %08lx\n",
197 __func__, addr, size, slot, prev_size[slot]))
198 return;
199
200 early_ioremap_dbg("%s(%p, %08lx) [%d]\n", __func__, addr, size, slot);
201
202 virt_addr = (unsigned long)addr;
203 if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)))
204 return;
205
206 offset = offset_in_page(virt_addr);
207 nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT;
208
209 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
210 while (nrpages > 0) {
211 if (after_paging_init)
212 __late_clear_fixmap(idx);
213 else
214 __early_set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR);
215 --idx;
216 --nrpages;
217 }
218 prev_map[slot] = NULL;
219}
220
221/* Remap an IO device */
222void __init __iomem *
223early_ioremap(resource_size_t phys_addr, unsigned long size)
224{
225 return __early_ioremap(phys_addr, size, FIXMAP_PAGE_IO);
226}
227
228/* Remap memory */
229void __init *
230early_memremap(resource_size_t phys_addr, unsigned long size)
231{
232 pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
233 FIXMAP_PAGE_NORMAL);
234
235 return (__force void *)__early_ioremap(phys_addr, size, prot);
236}
237#ifdef FIXMAP_PAGE_RO
238void __init *
239early_memremap_ro(resource_size_t phys_addr, unsigned long size)
240{
241 pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
242 FIXMAP_PAGE_RO);
243
244 return (__force void *)__early_ioremap(phys_addr, size, prot);
245}
246#endif
247
248#ifdef CONFIG_ARCH_USE_MEMREMAP_PROT
249void __init *
250early_memremap_prot(resource_size_t phys_addr, unsigned long size,
251 unsigned long prot_val)
252{
253 return (__force void *)__early_ioremap(phys_addr, size,
254 __pgprot(prot_val));
255}
256#endif
257
258#define MAX_MAP_CHUNK (NR_FIX_BTMAPS << PAGE_SHIFT)
259
260/*
261 * If no empty slot, handle that and return -ENOMEM.
262 */
263int __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
264{
265 unsigned long slop, clen;
266 char *p;
267
268 while (size) {
269 slop = offset_in_page(src);
270 clen = size;
271 if (clen > MAX_MAP_CHUNK - slop)
272 clen = MAX_MAP_CHUNK - slop;
273 p = early_memremap(src & PAGE_MASK, clen + slop);
274 if (!p)
275 return -ENOMEM;
276 memcpy(dest, p + slop, clen);
277 early_memunmap(p, clen + slop);
278 dest += clen;
279 src += clen;
280 size -= clen;
281 }
282 return 0;
283}
284
285#else /* CONFIG_MMU */
286
287void __init __iomem *
288early_ioremap(resource_size_t phys_addr, unsigned long size)
289{
290 return (__force void __iomem *)phys_addr;
291}
292
293/* Remap memory */
294void __init *
295early_memremap(resource_size_t phys_addr, unsigned long size)
296{
297 return (void *)phys_addr;
298}
299void __init *
300early_memremap_ro(resource_size_t phys_addr, unsigned long size)
301{
302 return (void *)phys_addr;
303}
304
305void __init early_iounmap(void __iomem *addr, unsigned long size)
306{
307}
308
309#endif /* CONFIG_MMU */
310
311
312void __init early_memunmap(void *addr, unsigned long size)
313{
314 early_iounmap((__force void __iomem *)addr, size);
315}