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
33static int after_paging_init __initdata;
34
35pgprot_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
42void __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
53static 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
61static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
62{
63 BUG();
64}
65#endif
66
67static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
68static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
69static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
70
71void __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
81static 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}
97late_initcall(check_early_ioremap_leak);
98
99static 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: phys_addr, flags: 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
162void __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, phys: 0, FIXMAP_PAGE_CLEAR);
203 --idx;
204 --nrpages;
205 }
206 prev_map[slot] = NULL;
207}
208
209/* Remap an IO device */
210void __init __iomem *
211early_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 */
217void __init *
218early_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
226void __init *
227early_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
237void __init *
238early_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/*
249 * If no empty slot, handle that and return -ENOMEM.
250 */
251int __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
252{
253 unsigned long slop, clen;
254 char *p;
255
256 while (size) {
257 slop = offset_in_page(src);
258 clen = size;
259 if (clen > MAX_MAP_CHUNK - slop)
260 clen = MAX_MAP_CHUNK - slop;
261 p = early_memremap(phys_addr: src & PAGE_MASK, size: clen + slop);
262 if (!p)
263 return -ENOMEM;
264 memcpy(to: dest, from: p + slop, len: clen);
265 early_memunmap(addr: p, size: clen + slop);
266 dest += clen;
267 src += clen;
268 size -= clen;
269 }
270 return 0;
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(addr: (__force void __iomem *)addr, size);
303}
304