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
22static int early_ioremap_debug __initdata;
23
24static int __init early_ioremap_debug_setup(char *str)
25{
26 early_ioremap_debug = 1;
27
28 return 0;
29}
30early_param("early_ioremap_debug", early_ioremap_debug_setup);
31
32static int after_paging_init __initdata;
33
34pgprot_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
41void __init __weak early_ioremap_shutdown(void)
42{
43}
44
45void __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
57static 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
65static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
66{
67 BUG();
68}
69#endif
70
71static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
72static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
73static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
74
75void __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
87static 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}
103late_initcall(check_early_ioremap_leak);
104
105static 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
168void __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 */
216void __init __iomem *
217early_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 */
223void __init *
224early_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
232void __init *
233early_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
243void __init *
244early_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
254void __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
275void __init __iomem *
276early_ioremap(resource_size_t phys_addr, unsigned long size)
277{
278 return (__force void __iomem *)phys_addr;
279}
280
281/* Remap memory */
282void __init *
283early_memremap(resource_size_t phys_addr, unsigned long size)
284{
285 return (void *)phys_addr;
286}
287void __init *
288early_memremap_ro(resource_size_t phys_addr, unsigned long size)
289{
290 return (void *)phys_addr;
291}
292
293void __init early_iounmap(void __iomem *addr, unsigned long size)
294{
295}
296
297#endif /* CONFIG_MMU */
298
299
300void __init early_memunmap(void *addr, unsigned long size)
301{
302 early_iounmap((__force void __iomem *)addr, size);
303}
304