1 // SPDX-License-Identifier: GPL-2.0
3 * Provide common bits of early_ioremap() support for architectures needing
4 * temporary mappings during boot before ioremap() is available.
6 * This is mostly a direct copy of the x86 early_ioremap implementation.
8 * (C) Copyright 1995 1996, 2014 Linus Torvalds
11 #include <linux/kernel.h>
12 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/slab.h>
17 #include <linux/vmalloc.h>
18 #include <asm/fixmap.h>
19 #include <asm/early_ioremap.h>
22 static int early_ioremap_debug __initdata;
24 static int __init early_ioremap_debug_setup(char *str)
26 early_ioremap_debug = 1;
30 early_param("early_ioremap_debug", early_ioremap_debug_setup);
32 static int after_paging_init __initdata;
34 pgprot_t __init __weak early_memremap_pgprot_adjust(resource_size_t phys_addr,
41 void __init __weak early_ioremap_shutdown(void)
45 void __init early_ioremap_reset(void)
47 early_ioremap_shutdown();
48 after_paging_init = 1;
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.
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)
64 #ifndef __late_clear_fixmap
65 static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
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;
75 void __init early_ioremap_setup(void)
79 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
80 if (WARN_ON(prev_map[i]))
83 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
84 slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
87 static int __init check_early_ioremap_leak(void)
92 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
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",
103 late_initcall(check_early_ioremap_leak);
105 static void __init __iomem *
106 __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
108 unsigned long offset;
109 resource_size_t last_addr;
110 unsigned int nrpages;
111 enum fixed_addresses idx;
114 WARN_ON(system_state >= SYSTEM_RUNNING);
117 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
124 if (WARN(slot < 0, "%s(%pa, %08lx) not found slot\n",
125 __func__, &phys_addr, size))
128 /* Don't allow wraparound or zero size */
129 last_addr = phys_addr + size - 1;
130 if (WARN_ON(!size || last_addr < phys_addr))
133 prev_size[slot] = size;
135 * Mappings have to be page-aligned
137 offset = offset_in_page(phys_addr);
138 phys_addr &= PAGE_MASK;
139 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
142 * Mappings have to fit in the FIX_BTMAP area.
144 nrpages = size >> PAGE_SHIFT;
145 if (WARN_ON(nrpages > NR_FIX_BTMAPS))
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);
156 __early_set_fixmap(idx, phys_addr, prot);
157 phys_addr += PAGE_SIZE;
161 WARN(early_ioremap_debug, "%s(%pa, %08lx) [%d] => %08lx + %08lx\n",
162 __func__, &phys_addr, size, slot, offset, slot_virt[slot]);
164 prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
165 return prev_map[slot];
168 void __init early_iounmap(void __iomem *addr, unsigned long size)
170 unsigned long virt_addr;
171 unsigned long offset;
172 unsigned int nrpages;
173 enum fixed_addresses idx;
177 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
178 if (prev_map[i] == addr) {
184 if (WARN(slot < 0, "early_iounmap(%p, %08lx) not found slot\n",
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]))
193 WARN(early_ioremap_debug, "early_iounmap(%p, %08lx) [%d]\n",
196 virt_addr = (unsigned long)addr;
197 if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)))
200 offset = offset_in_page(virt_addr);
201 nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT;
203 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
204 while (nrpages > 0) {
205 if (after_paging_init)
206 __late_clear_fixmap(idx);
208 __early_set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR);
212 prev_map[slot] = NULL;
215 /* Remap an IO device */
216 void __init __iomem *
217 early_ioremap(resource_size_t phys_addr, unsigned long size)
219 return __early_ioremap(phys_addr, size, FIXMAP_PAGE_IO);
224 early_memremap(resource_size_t phys_addr, unsigned long size)
226 pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
229 return (__force void *)__early_ioremap(phys_addr, size, prot);
231 #ifdef FIXMAP_PAGE_RO
233 early_memremap_ro(resource_size_t phys_addr, unsigned long size)
235 pgprot_t prot = early_memremap_pgprot_adjust(phys_addr, size,
238 return (__force void *)__early_ioremap(phys_addr, size, prot);
242 #ifdef CONFIG_ARCH_USE_MEMREMAP_PROT
244 early_memremap_prot(resource_size_t phys_addr, unsigned long size,
245 unsigned long prot_val)
247 return (__force void *)__early_ioremap(phys_addr, size,
252 #define MAX_MAP_CHUNK (NR_FIX_BTMAPS << PAGE_SHIFT)
254 void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
256 unsigned long slop, clen;
260 slop = offset_in_page(src);
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);
273 #else /* CONFIG_MMU */
275 void __init __iomem *
276 early_ioremap(resource_size_t phys_addr, unsigned long size)
278 return (__force void __iomem *)phys_addr;
283 early_memremap(resource_size_t phys_addr, unsigned long size)
285 return (void *)phys_addr;
288 early_memremap_ro(resource_size_t phys_addr, unsigned long size)
290 return (void *)phys_addr;
293 void __init early_iounmap(void __iomem *addr, unsigned long size)
297 #endif /* CONFIG_MMU */
300 void __init early_memunmap(void *addr, unsigned long size)
302 early_iounmap((__force void __iomem *)addr, size);