2 * Provide common bits of early_ioremap() support for architectures needing
3 * temporary mappings during boot before ioremap() is available.
5 * This is mostly a direct copy of the x86 early_ioremap implementation.
7 * (C) Copyright 1995 1996, 2014 Linus Torvalds
10 #include <linux/kernel.h>
11 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
16 #include <linux/vmalloc.h>
17 #include <asm/fixmap.h>
18 #include <asm/early_ioremap.h>
21 static int early_ioremap_debug __initdata;
23 static int __init early_ioremap_debug_setup(char *str)
25 early_ioremap_debug = 1;
29 early_param("early_ioremap_debug", early_ioremap_debug_setup);
31 static int after_paging_init __initdata;
33 void __init __weak early_ioremap_shutdown(void)
37 void __init early_ioremap_reset(void)
39 early_ioremap_shutdown();
40 after_paging_init = 1;
44 * Generally, ioremap() is available after paging_init() has been called.
45 * Architectures wanting to allow early_ioremap after paging_init() can
46 * define __late_set_fixmap and __late_clear_fixmap to do the right thing.
48 #ifndef __late_set_fixmap
49 static inline void __init __late_set_fixmap(enum fixed_addresses idx,
50 phys_addr_t phys, pgprot_t prot)
56 #ifndef __late_clear_fixmap
57 static inline void __init __late_clear_fixmap(enum fixed_addresses idx)
63 static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata;
64 static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata;
65 static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata;
67 void __init early_ioremap_setup(void)
71 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
72 if (WARN_ON(prev_map[i]))
75 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
76 slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i);
79 static int __init check_early_ioremap_leak(void)
84 for (i = 0; i < FIX_BTMAPS_SLOTS; i++)
88 if (WARN(count, KERN_WARNING
89 "Debug warning: early ioremap leak of %d areas detected.\n"
90 "please boot with early_ioremap_debug and report the dmesg.\n",
95 late_initcall(check_early_ioremap_leak);
97 static void __init __iomem *
98 __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot)
100 unsigned long offset;
101 resource_size_t last_addr;
102 unsigned int nrpages;
103 enum fixed_addresses idx;
106 WARN_ON(system_state != SYSTEM_BOOTING);
109 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
116 if (WARN(slot < 0, "%s(%08llx, %08lx) not found slot\n",
117 __func__, (u64)phys_addr, size))
120 /* Don't allow wraparound or zero size */
121 last_addr = phys_addr + size - 1;
122 if (WARN_ON(!size || last_addr < phys_addr))
125 prev_size[slot] = size;
127 * Mappings have to be page-aligned
129 offset = offset_in_page(phys_addr);
130 phys_addr &= PAGE_MASK;
131 size = PAGE_ALIGN(last_addr + 1) - phys_addr;
134 * Mappings have to fit in the FIX_BTMAP area.
136 nrpages = size >> PAGE_SHIFT;
137 if (WARN_ON(nrpages > NR_FIX_BTMAPS))
143 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
144 while (nrpages > 0) {
145 if (after_paging_init)
146 __late_set_fixmap(idx, phys_addr, prot);
148 __early_set_fixmap(idx, phys_addr, prot);
149 phys_addr += PAGE_SIZE;
153 WARN(early_ioremap_debug, "%s(%08llx, %08lx) [%d] => %08lx + %08lx\n",
154 __func__, (u64)phys_addr, size, slot, offset, slot_virt[slot]);
156 prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]);
157 return prev_map[slot];
160 void __init early_iounmap(void __iomem *addr, unsigned long size)
162 unsigned long virt_addr;
163 unsigned long offset;
164 unsigned int nrpages;
165 enum fixed_addresses idx;
169 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) {
170 if (prev_map[i] == addr) {
176 if (WARN(slot < 0, "early_iounmap(%p, %08lx) not found slot\n",
180 if (WARN(prev_size[slot] != size,
181 "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n",
182 addr, size, slot, prev_size[slot]))
185 WARN(early_ioremap_debug, "early_iounmap(%p, %08lx) [%d]\n",
188 virt_addr = (unsigned long)addr;
189 if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN)))
192 offset = offset_in_page(virt_addr);
193 nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT;
195 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot;
196 while (nrpages > 0) {
197 if (after_paging_init)
198 __late_clear_fixmap(idx);
200 __early_set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR);
204 prev_map[slot] = NULL;
207 /* Remap an IO device */
208 void __init __iomem *
209 early_ioremap(resource_size_t phys_addr, unsigned long size)
211 return __early_ioremap(phys_addr, size, FIXMAP_PAGE_IO);
216 early_memremap(resource_size_t phys_addr, unsigned long size)
218 return (__force void *)__early_ioremap(phys_addr, size,
221 #ifdef FIXMAP_PAGE_RO
223 early_memremap_ro(resource_size_t phys_addr, unsigned long size)
225 return (__force void *)__early_ioremap(phys_addr, size, FIXMAP_PAGE_RO);
229 #define MAX_MAP_CHUNK (NR_FIX_BTMAPS << PAGE_SHIFT)
231 void __init copy_from_early_mem(void *dest, phys_addr_t src, unsigned long size)
233 unsigned long slop, clen;
237 slop = offset_in_page(src);
239 if (clen > MAX_MAP_CHUNK - slop)
240 clen = MAX_MAP_CHUNK - slop;
241 p = early_memremap(src & PAGE_MASK, clen + slop);
242 memcpy(dest, p + slop, clen);
243 early_memunmap(p, clen + slop);
250 #else /* CONFIG_MMU */
252 void __init __iomem *
253 early_ioremap(resource_size_t phys_addr, unsigned long size)
255 return (__force void __iomem *)phys_addr;
260 early_memremap(resource_size_t phys_addr, unsigned long size)
262 return (void *)phys_addr;
265 early_memremap_ro(resource_size_t phys_addr, unsigned long size)
267 return (void *)phys_addr;
270 void __init early_iounmap(void __iomem *addr, unsigned long size)
274 #endif /* CONFIG_MMU */
277 void __init early_memunmap(void *addr, unsigned long size)
279 early_iounmap((__force void __iomem *)addr, size);