1 /* 2 * linux/arch/arm/mm/ioremap.c 3 * 4 * Re-map IO memory to kernel address space so that we can access it. 5 * 6 * (C) Copyright 1995 1996 Linus Torvalds 7 * 8 * Hacked for ARM by Phil Blundell <philb@gnu.org> 9 * Hacked to allow all architectures to build, and various cleanups 10 * by Russell King 11 * 12 * This allows a driver to remap an arbitrary region of bus memory into 13 * virtual space. One should *only* use readl, writel, memcpy_toio and 14 * so on with such remapped areas. 15 * 16 * Because the ARM only has a 32-bit address space we can't address the 17 * whole of the (physical) PCI space at once. PCI huge-mode addressing 18 * allows us to circumvent this restriction by splitting PCI space into 19 * two 2GB chunks and mapping only one at a time into processor memory. 20 * We use MMU protection domains to trap any attempt to access the bank 21 * that is not currently mapped. (This isn't fully implemented yet.) 22 */ 23 #include <linux/module.h> 24 #include <linux/errno.h> 25 #include <linux/mm.h> 26 #include <linux/vmalloc.h> 27 #include <linux/io.h> 28 #include <linux/sizes.h> 29 30 #include <asm/cp15.h> 31 #include <asm/cputype.h> 32 #include <asm/cacheflush.h> 33 #include <asm/early_ioremap.h> 34 #include <asm/mmu_context.h> 35 #include <asm/pgalloc.h> 36 #include <asm/tlbflush.h> 37 #include <asm/system_info.h> 38 39 #include <asm/mach/map.h> 40 #include <asm/mach/pci.h> 41 #include "mm.h" 42 43 44 LIST_HEAD(static_vmlist); 45 46 static struct static_vm *find_static_vm_paddr(phys_addr_t paddr, 47 size_t size, unsigned int mtype) 48 { 49 struct static_vm *svm; 50 struct vm_struct *vm; 51 52 list_for_each_entry(svm, &static_vmlist, list) { 53 vm = &svm->vm; 54 if (!(vm->flags & VM_ARM_STATIC_MAPPING)) 55 continue; 56 if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype)) 57 continue; 58 59 if (vm->phys_addr > paddr || 60 paddr + size - 1 > vm->phys_addr + vm->size - 1) 61 continue; 62 63 return svm; 64 } 65 66 return NULL; 67 } 68 69 struct static_vm *find_static_vm_vaddr(void *vaddr) 70 { 71 struct static_vm *svm; 72 struct vm_struct *vm; 73 74 list_for_each_entry(svm, &static_vmlist, list) { 75 vm = &svm->vm; 76 77 /* static_vmlist is ascending order */ 78 if (vm->addr > vaddr) 79 break; 80 81 if (vm->addr <= vaddr && vm->addr + vm->size > vaddr) 82 return svm; 83 } 84 85 return NULL; 86 } 87 88 void __init add_static_vm_early(struct static_vm *svm) 89 { 90 struct static_vm *curr_svm; 91 struct vm_struct *vm; 92 void *vaddr; 93 94 vm = &svm->vm; 95 vm_area_add_early(vm); 96 vaddr = vm->addr; 97 98 list_for_each_entry(curr_svm, &static_vmlist, list) { 99 vm = &curr_svm->vm; 100 101 if (vm->addr > vaddr) 102 break; 103 } 104 list_add_tail(&svm->list, &curr_svm->list); 105 } 106 107 int ioremap_page(unsigned long virt, unsigned long phys, 108 const struct mem_type *mtype) 109 { 110 return ioremap_page_range(virt, virt + PAGE_SIZE, phys, 111 __pgprot(mtype->prot_pte)); 112 } 113 EXPORT_SYMBOL(ioremap_page); 114 115 void __check_vmalloc_seq(struct mm_struct *mm) 116 { 117 unsigned int seq; 118 119 do { 120 seq = init_mm.context.vmalloc_seq; 121 memcpy(pgd_offset(mm, VMALLOC_START), 122 pgd_offset_k(VMALLOC_START), 123 sizeof(pgd_t) * (pgd_index(VMALLOC_END) - 124 pgd_index(VMALLOC_START))); 125 mm->context.vmalloc_seq = seq; 126 } while (seq != init_mm.context.vmalloc_seq); 127 } 128 129 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) 130 /* 131 * Section support is unsafe on SMP - If you iounmap and ioremap a region, 132 * the other CPUs will not see this change until their next context switch. 133 * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs 134 * which requires the new ioremap'd region to be referenced, the CPU will 135 * reference the _old_ region. 136 * 137 * Note that get_vm_area_caller() allocates a guard 4K page, so we need to 138 * mask the size back to 1MB aligned or we will overflow in the loop below. 139 */ 140 static void unmap_area_sections(unsigned long virt, unsigned long size) 141 { 142 unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1)); 143 pgd_t *pgd; 144 pud_t *pud; 145 pmd_t *pmdp; 146 147 flush_cache_vunmap(addr, end); 148 pgd = pgd_offset_k(addr); 149 pud = pud_offset(pgd, addr); 150 pmdp = pmd_offset(pud, addr); 151 do { 152 pmd_t pmd = *pmdp; 153 154 if (!pmd_none(pmd)) { 155 /* 156 * Clear the PMD from the page table, and 157 * increment the vmalloc sequence so others 158 * notice this change. 159 * 160 * Note: this is still racy on SMP machines. 161 */ 162 pmd_clear(pmdp); 163 init_mm.context.vmalloc_seq++; 164 165 /* 166 * Free the page table, if there was one. 167 */ 168 if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE) 169 pte_free_kernel(&init_mm, pmd_page_vaddr(pmd)); 170 } 171 172 addr += PMD_SIZE; 173 pmdp += 2; 174 } while (addr < end); 175 176 /* 177 * Ensure that the active_mm is up to date - we want to 178 * catch any use-after-iounmap cases. 179 */ 180 if (current->active_mm->context.vmalloc_seq != init_mm.context.vmalloc_seq) 181 __check_vmalloc_seq(current->active_mm); 182 183 flush_tlb_kernel_range(virt, end); 184 } 185 186 static int 187 remap_area_sections(unsigned long virt, unsigned long pfn, 188 size_t size, const struct mem_type *type) 189 { 190 unsigned long addr = virt, end = virt + size; 191 pgd_t *pgd; 192 pud_t *pud; 193 pmd_t *pmd; 194 195 /* 196 * Remove and free any PTE-based mapping, and 197 * sync the current kernel mapping. 198 */ 199 unmap_area_sections(virt, size); 200 201 pgd = pgd_offset_k(addr); 202 pud = pud_offset(pgd, addr); 203 pmd = pmd_offset(pud, addr); 204 do { 205 pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); 206 pfn += SZ_1M >> PAGE_SHIFT; 207 pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); 208 pfn += SZ_1M >> PAGE_SHIFT; 209 flush_pmd_entry(pmd); 210 211 addr += PMD_SIZE; 212 pmd += 2; 213 } while (addr < end); 214 215 return 0; 216 } 217 218 static int 219 remap_area_supersections(unsigned long virt, unsigned long pfn, 220 size_t size, const struct mem_type *type) 221 { 222 unsigned long addr = virt, end = virt + size; 223 pgd_t *pgd; 224 pud_t *pud; 225 pmd_t *pmd; 226 227 /* 228 * Remove and free any PTE-based mapping, and 229 * sync the current kernel mapping. 230 */ 231 unmap_area_sections(virt, size); 232 233 pgd = pgd_offset_k(virt); 234 pud = pud_offset(pgd, addr); 235 pmd = pmd_offset(pud, addr); 236 do { 237 unsigned long super_pmd_val, i; 238 239 super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect | 240 PMD_SECT_SUPER; 241 super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20; 242 243 for (i = 0; i < 8; i++) { 244 pmd[0] = __pmd(super_pmd_val); 245 pmd[1] = __pmd(super_pmd_val); 246 flush_pmd_entry(pmd); 247 248 addr += PMD_SIZE; 249 pmd += 2; 250 } 251 252 pfn += SUPERSECTION_SIZE >> PAGE_SHIFT; 253 } while (addr < end); 254 255 return 0; 256 } 257 #endif 258 259 static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn, 260 unsigned long offset, size_t size, unsigned int mtype, void *caller) 261 { 262 const struct mem_type *type; 263 int err; 264 unsigned long addr; 265 struct vm_struct *area; 266 phys_addr_t paddr = __pfn_to_phys(pfn); 267 268 #ifndef CONFIG_ARM_LPAE 269 /* 270 * High mappings must be supersection aligned 271 */ 272 if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK)) 273 return NULL; 274 #endif 275 276 type = get_mem_type(mtype); 277 if (!type) 278 return NULL; 279 280 /* 281 * Page align the mapping size, taking account of any offset. 282 */ 283 size = PAGE_ALIGN(offset + size); 284 285 /* 286 * Try to reuse one of the static mapping whenever possible. 287 */ 288 if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) { 289 struct static_vm *svm; 290 291 svm = find_static_vm_paddr(paddr, size, mtype); 292 if (svm) { 293 addr = (unsigned long)svm->vm.addr; 294 addr += paddr - svm->vm.phys_addr; 295 return (void __iomem *) (offset + addr); 296 } 297 } 298 299 /* 300 * Don't allow RAM to be mapped with mismatched attributes - this 301 * causes problems with ARMv6+ 302 */ 303 if (WARN_ON(pfn_valid(pfn) && mtype != MT_MEMORY_RW)) 304 return NULL; 305 306 area = get_vm_area_caller(size, VM_IOREMAP, caller); 307 if (!area) 308 return NULL; 309 addr = (unsigned long)area->addr; 310 area->phys_addr = paddr; 311 312 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) 313 if (DOMAIN_IO == 0 && 314 (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) || 315 cpu_is_xsc3()) && pfn >= 0x100000 && 316 !((paddr | size | addr) & ~SUPERSECTION_MASK)) { 317 area->flags |= VM_ARM_SECTION_MAPPING; 318 err = remap_area_supersections(addr, pfn, size, type); 319 } else if (!((paddr | size | addr) & ~PMD_MASK)) { 320 area->flags |= VM_ARM_SECTION_MAPPING; 321 err = remap_area_sections(addr, pfn, size, type); 322 } else 323 #endif 324 err = ioremap_page_range(addr, addr + size, paddr, 325 __pgprot(type->prot_pte)); 326 327 if (err) { 328 vunmap((void *)addr); 329 return NULL; 330 } 331 332 flush_cache_vmap(addr, addr + size); 333 return (void __iomem *) (offset + addr); 334 } 335 336 void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size, 337 unsigned int mtype, void *caller) 338 { 339 phys_addr_t last_addr; 340 unsigned long offset = phys_addr & ~PAGE_MASK; 341 unsigned long pfn = __phys_to_pfn(phys_addr); 342 343 /* 344 * Don't allow wraparound or zero size 345 */ 346 last_addr = phys_addr + size - 1; 347 if (!size || last_addr < phys_addr) 348 return NULL; 349 350 return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, 351 caller); 352 } 353 354 /* 355 * Remap an arbitrary physical address space into the kernel virtual 356 * address space. Needed when the kernel wants to access high addresses 357 * directly. 358 * 359 * NOTE! We need to allow non-page-aligned mappings too: we will obviously 360 * have to convert them into an offset in a page-aligned mapping, but the 361 * caller shouldn't need to know that small detail. 362 */ 363 void __iomem * 364 __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size, 365 unsigned int mtype) 366 { 367 return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, 368 __builtin_return_address(0)); 369 } 370 EXPORT_SYMBOL(__arm_ioremap_pfn); 371 372 void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t, 373 unsigned int, void *) = 374 __arm_ioremap_caller; 375 376 void __iomem *ioremap(resource_size_t res_cookie, size_t size) 377 { 378 return arch_ioremap_caller(res_cookie, size, MT_DEVICE, 379 __builtin_return_address(0)); 380 } 381 EXPORT_SYMBOL(ioremap); 382 383 void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size) 384 __alias(ioremap_cached); 385 386 void __iomem *ioremap_cached(resource_size_t res_cookie, size_t size) 387 { 388 return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED, 389 __builtin_return_address(0)); 390 } 391 EXPORT_SYMBOL(ioremap_cache); 392 EXPORT_SYMBOL(ioremap_cached); 393 394 void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size) 395 { 396 return arch_ioremap_caller(res_cookie, size, MT_DEVICE_WC, 397 __builtin_return_address(0)); 398 } 399 EXPORT_SYMBOL(ioremap_wc); 400 401 /* 402 * Remap an arbitrary physical address space into the kernel virtual 403 * address space as memory. Needed when the kernel wants to execute 404 * code in external memory. This is needed for reprogramming source 405 * clocks that would affect normal memory for example. Please see 406 * CONFIG_GENERIC_ALLOCATOR for allocating external memory. 407 */ 408 void __iomem * 409 __arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached) 410 { 411 unsigned int mtype; 412 413 if (cached) 414 mtype = MT_MEMORY_RWX; 415 else 416 mtype = MT_MEMORY_RWX_NONCACHED; 417 418 return __arm_ioremap_caller(phys_addr, size, mtype, 419 __builtin_return_address(0)); 420 } 421 422 void *arch_memremap_wb(phys_addr_t phys_addr, size_t size) 423 { 424 return (__force void *)arch_ioremap_caller(phys_addr, size, 425 MT_MEMORY_RW, 426 __builtin_return_address(0)); 427 } 428 429 void __iounmap(volatile void __iomem *io_addr) 430 { 431 void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr); 432 struct static_vm *svm; 433 434 /* If this is a static mapping, we must leave it alone */ 435 svm = find_static_vm_vaddr(addr); 436 if (svm) 437 return; 438 439 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) 440 { 441 struct vm_struct *vm; 442 443 vm = find_vm_area(addr); 444 445 /* 446 * If this is a section based mapping we need to handle it 447 * specially as the VM subsystem does not know how to handle 448 * such a beast. 449 */ 450 if (vm && (vm->flags & VM_ARM_SECTION_MAPPING)) 451 unmap_area_sections((unsigned long)vm->addr, vm->size); 452 } 453 #endif 454 455 vunmap(addr); 456 } 457 458 void (*arch_iounmap)(volatile void __iomem *) = __iounmap; 459 460 void iounmap(volatile void __iomem *cookie) 461 { 462 arch_iounmap(cookie); 463 } 464 EXPORT_SYMBOL(iounmap); 465 466 #ifdef CONFIG_PCI 467 static int pci_ioremap_mem_type = MT_DEVICE; 468 469 void pci_ioremap_set_mem_type(int mem_type) 470 { 471 pci_ioremap_mem_type = mem_type; 472 } 473 474 int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr) 475 { 476 BUG_ON(offset + SZ_64K > IO_SPACE_LIMIT); 477 478 return ioremap_page_range(PCI_IO_VIRT_BASE + offset, 479 PCI_IO_VIRT_BASE + offset + SZ_64K, 480 phys_addr, 481 __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte)); 482 } 483 EXPORT_SYMBOL_GPL(pci_ioremap_io); 484 485 void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size) 486 { 487 return arch_ioremap_caller(res_cookie, size, MT_UNCACHED, 488 __builtin_return_address(0)); 489 } 490 EXPORT_SYMBOL_GPL(pci_remap_cfgspace); 491 #endif 492 493 /* 494 * Must be called after early_fixmap_init 495 */ 496 void __init early_ioremap_init(void) 497 { 498 early_ioremap_setup(); 499 } 500