1 /* 2 * Provide common bits of early_ioremap() support for architectures needing 3 * temporary mappings during boot before ioremap() is available. 4 * 5 * This is mostly a direct copy of the x86 early_ioremap implementation. 6 * 7 * (C) Copyright 1995 1996, 2014 Linus Torvalds 8 * 9 */ 10 #include <linux/kernel.h> 11 #include <linux/init.h> 12 #include <linux/io.h> 13 #include <linux/module.h> 14 #include <linux/slab.h> 15 #include <linux/mm.h> 16 #include <linux/vmalloc.h> 17 #include <asm/fixmap.h> 18 19 #ifdef CONFIG_MMU 20 static int early_ioremap_debug __initdata; 21 22 static int __init early_ioremap_debug_setup(char *str) 23 { 24 early_ioremap_debug = 1; 25 26 return 0; 27 } 28 early_param("early_ioremap_debug", early_ioremap_debug_setup); 29 30 static int after_paging_init __initdata; 31 32 void __init __weak early_ioremap_shutdown(void) 33 { 34 } 35 36 void __init early_ioremap_reset(void) 37 { 38 early_ioremap_shutdown(); 39 after_paging_init = 1; 40 } 41 42 /* 43 * Generally, ioremap() is available after paging_init() has been called. 44 * Architectures wanting to allow early_ioremap after paging_init() can 45 * define __late_set_fixmap and __late_clear_fixmap to do the right thing. 46 */ 47 #ifndef __late_set_fixmap 48 static inline void __init __late_set_fixmap(enum fixed_addresses idx, 49 phys_addr_t phys, pgprot_t prot) 50 { 51 BUG(); 52 } 53 #endif 54 55 #ifndef __late_clear_fixmap 56 static inline void __init __late_clear_fixmap(enum fixed_addresses idx) 57 { 58 BUG(); 59 } 60 #endif 61 62 static void __iomem *prev_map[FIX_BTMAPS_SLOTS] __initdata; 63 static unsigned long prev_size[FIX_BTMAPS_SLOTS] __initdata; 64 static unsigned long slot_virt[FIX_BTMAPS_SLOTS] __initdata; 65 66 void __init early_ioremap_setup(void) 67 { 68 int i; 69 70 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) 71 if (WARN_ON(prev_map[i])) 72 break; 73 74 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) 75 slot_virt[i] = __fix_to_virt(FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*i); 76 } 77 78 static int __init check_early_ioremap_leak(void) 79 { 80 int count = 0; 81 int i; 82 83 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) 84 if (prev_map[i]) 85 count++; 86 87 if (WARN(count, KERN_WARNING 88 "Debug warning: early ioremap leak of %d areas detected.\n" 89 "please boot with early_ioremap_debug and report the dmesg.\n", 90 count)) 91 return 1; 92 return 0; 93 } 94 late_initcall(check_early_ioremap_leak); 95 96 static void __init __iomem * 97 __early_ioremap(resource_size_t phys_addr, unsigned long size, pgprot_t prot) 98 { 99 unsigned long offset; 100 resource_size_t last_addr; 101 unsigned int nrpages; 102 enum fixed_addresses idx; 103 int i, slot; 104 105 WARN_ON(system_state != SYSTEM_BOOTING); 106 107 slot = -1; 108 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) { 109 if (!prev_map[i]) { 110 slot = i; 111 break; 112 } 113 } 114 115 if (WARN(slot < 0, "%s(%08llx, %08lx) not found slot\n", 116 __func__, (u64)phys_addr, size)) 117 return NULL; 118 119 /* Don't allow wraparound or zero size */ 120 last_addr = phys_addr + size - 1; 121 if (WARN_ON(!size || last_addr < phys_addr)) 122 return NULL; 123 124 prev_size[slot] = size; 125 /* 126 * Mappings have to be page-aligned 127 */ 128 offset = phys_addr & ~PAGE_MASK; 129 phys_addr &= PAGE_MASK; 130 size = PAGE_ALIGN(last_addr + 1) - phys_addr; 131 132 /* 133 * Mappings have to fit in the FIX_BTMAP area. 134 */ 135 nrpages = size >> PAGE_SHIFT; 136 if (WARN_ON(nrpages > NR_FIX_BTMAPS)) 137 return NULL; 138 139 /* 140 * Ok, go for it.. 141 */ 142 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot; 143 while (nrpages > 0) { 144 if (after_paging_init) 145 __late_set_fixmap(idx, phys_addr, prot); 146 else 147 __early_set_fixmap(idx, phys_addr, prot); 148 phys_addr += PAGE_SIZE; 149 --idx; 150 --nrpages; 151 } 152 WARN(early_ioremap_debug, "%s(%08llx, %08lx) [%d] => %08lx + %08lx\n", 153 __func__, (u64)phys_addr, size, slot, offset, slot_virt[slot]); 154 155 prev_map[slot] = (void __iomem *)(offset + slot_virt[slot]); 156 return prev_map[slot]; 157 } 158 159 void __init early_iounmap(void __iomem *addr, unsigned long size) 160 { 161 unsigned long virt_addr; 162 unsigned long offset; 163 unsigned int nrpages; 164 enum fixed_addresses idx; 165 int i, slot; 166 167 slot = -1; 168 for (i = 0; i < FIX_BTMAPS_SLOTS; i++) { 169 if (prev_map[i] == addr) { 170 slot = i; 171 break; 172 } 173 } 174 175 if (WARN(slot < 0, "early_iounmap(%p, %08lx) not found slot\n", 176 addr, size)) 177 return; 178 179 if (WARN(prev_size[slot] != size, 180 "early_iounmap(%p, %08lx) [%d] size not consistent %08lx\n", 181 addr, size, slot, prev_size[slot])) 182 return; 183 184 WARN(early_ioremap_debug, "early_iounmap(%p, %08lx) [%d]\n", 185 addr, size, slot); 186 187 virt_addr = (unsigned long)addr; 188 if (WARN_ON(virt_addr < fix_to_virt(FIX_BTMAP_BEGIN))) 189 return; 190 191 offset = virt_addr & ~PAGE_MASK; 192 nrpages = PAGE_ALIGN(offset + size) >> PAGE_SHIFT; 193 194 idx = FIX_BTMAP_BEGIN - NR_FIX_BTMAPS*slot; 195 while (nrpages > 0) { 196 if (after_paging_init) 197 __late_clear_fixmap(idx); 198 else 199 __early_set_fixmap(idx, 0, FIXMAP_PAGE_CLEAR); 200 --idx; 201 --nrpages; 202 } 203 prev_map[slot] = NULL; 204 } 205 206 /* Remap an IO device */ 207 void __init __iomem * 208 early_ioremap(resource_size_t phys_addr, unsigned long size) 209 { 210 return __early_ioremap(phys_addr, size, FIXMAP_PAGE_IO); 211 } 212 213 /* Remap memory */ 214 void __init * 215 early_memremap(resource_size_t phys_addr, unsigned long size) 216 { 217 return (__force void *)__early_ioremap(phys_addr, size, 218 FIXMAP_PAGE_NORMAL); 219 } 220 #ifdef FIXMAP_PAGE_RO 221 void __init * 222 early_memremap_ro(resource_size_t phys_addr, unsigned long size) 223 { 224 return (__force void *)__early_ioremap(phys_addr, size, FIXMAP_PAGE_RO); 225 } 226 #endif 227 #else /* CONFIG_MMU */ 228 229 void __init __iomem * 230 early_ioremap(resource_size_t phys_addr, unsigned long size) 231 { 232 return (__force void __iomem *)phys_addr; 233 } 234 235 /* Remap memory */ 236 void __init * 237 early_memremap(resource_size_t phys_addr, unsigned long size) 238 { 239 return (void *)phys_addr; 240 } 241 void __init * 242 early_memremap_ro(resource_size_t phys_addr, unsigned long size) 243 { 244 return (void *)phys_addr; 245 } 246 247 void __init early_iounmap(void __iomem *addr, unsigned long size) 248 { 249 } 250 251 #endif /* CONFIG_MMU */ 252 253 254 void __init early_memunmap(void *addr, unsigned long size) 255 { 256 early_iounmap((__force void __iomem *)addr, size); 257 } 258