1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/arch/arm/mm/ioremap.c 4 * 5 * Re-map IO memory to kernel address space so that we can access it. 6 * 7 * (C) Copyright 1995 1996 Linus Torvalds 8 * 9 * Hacked for ARM by Phil Blundell <philb@gnu.org> 10 * Hacked to allow all architectures to build, and various cleanups 11 * by Russell King 12 * 13 * This allows a driver to remap an arbitrary region of bus memory into 14 * virtual space. One should *only* use readl, writel, memcpy_toio and 15 * so on with such remapped areas. 16 * 17 * Because the ARM only has a 32-bit address space we can't address the 18 * whole of the (physical) PCI space at once. PCI huge-mode addressing 19 * allows us to circumvent this restriction by splitting PCI space into 20 * two 2GB chunks and mapping only one at a time into processor memory. 21 * We use MMU protection domains to trap any attempt to access the bank 22 * that is not currently mapped. (This isn't fully implemented yet.) 23 */ 24 #include <linux/module.h> 25 #include <linux/errno.h> 26 #include <linux/mm.h> 27 #include <linux/vmalloc.h> 28 #include <linux/io.h> 29 #include <linux/sizes.h> 30 #include <linux/memblock.h> 31 32 #include <asm/cp15.h> 33 #include <asm/cputype.h> 34 #include <asm/cacheflush.h> 35 #include <asm/early_ioremap.h> 36 #include <asm/mmu_context.h> 37 #include <asm/pgalloc.h> 38 #include <asm/tlbflush.h> 39 #include <asm/set_memory.h> 40 #include <asm/system_info.h> 41 42 #include <asm/mach/map.h> 43 #include <asm/mach/pci.h> 44 #include "mm.h" 45 46 47 LIST_HEAD(static_vmlist); 48 49 static struct static_vm *find_static_vm_paddr(phys_addr_t paddr, 50 size_t size, unsigned int mtype) 51 { 52 struct static_vm *svm; 53 struct vm_struct *vm; 54 55 list_for_each_entry(svm, &static_vmlist, list) { 56 vm = &svm->vm; 57 if (!(vm->flags & VM_ARM_STATIC_MAPPING)) 58 continue; 59 if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype)) 60 continue; 61 62 if (vm->phys_addr > paddr || 63 paddr + size - 1 > vm->phys_addr + vm->size - 1) 64 continue; 65 66 return svm; 67 } 68 69 return NULL; 70 } 71 72 struct static_vm *find_static_vm_vaddr(void *vaddr) 73 { 74 struct static_vm *svm; 75 struct vm_struct *vm; 76 77 list_for_each_entry(svm, &static_vmlist, list) { 78 vm = &svm->vm; 79 80 /* static_vmlist is ascending order */ 81 if (vm->addr > vaddr) 82 break; 83 84 if (vm->addr <= vaddr && vm->addr + vm->size > vaddr) 85 return svm; 86 } 87 88 return NULL; 89 } 90 91 void __init add_static_vm_early(struct static_vm *svm) 92 { 93 struct static_vm *curr_svm; 94 struct vm_struct *vm; 95 void *vaddr; 96 97 vm = &svm->vm; 98 vm_area_add_early(vm); 99 vaddr = vm->addr; 100 101 list_for_each_entry(curr_svm, &static_vmlist, list) { 102 vm = &curr_svm->vm; 103 104 if (vm->addr > vaddr) 105 break; 106 } 107 list_add_tail(&svm->list, &curr_svm->list); 108 } 109 110 int ioremap_page(unsigned long virt, unsigned long phys, 111 const struct mem_type *mtype) 112 { 113 return ioremap_page_range(virt, virt + PAGE_SIZE, phys, 114 __pgprot(mtype->prot_pte)); 115 } 116 EXPORT_SYMBOL(ioremap_page); 117 118 void __check_vmalloc_seq(struct mm_struct *mm) 119 { 120 unsigned int seq; 121 122 do { 123 seq = init_mm.context.vmalloc_seq; 124 memcpy(pgd_offset(mm, VMALLOC_START), 125 pgd_offset_k(VMALLOC_START), 126 sizeof(pgd_t) * (pgd_index(VMALLOC_END) - 127 pgd_index(VMALLOC_START))); 128 mm->context.vmalloc_seq = seq; 129 } while (seq != init_mm.context.vmalloc_seq); 130 } 131 132 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) 133 /* 134 * Section support is unsafe on SMP - If you iounmap and ioremap a region, 135 * the other CPUs will not see this change until their next context switch. 136 * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs 137 * which requires the new ioremap'd region to be referenced, the CPU will 138 * reference the _old_ region. 139 * 140 * Note that get_vm_area_caller() allocates a guard 4K page, so we need to 141 * mask the size back to 1MB aligned or we will overflow in the loop below. 142 */ 143 static void unmap_area_sections(unsigned long virt, unsigned long size) 144 { 145 unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1)); 146 pmd_t *pmdp = pmd_off_k(addr); 147 148 do { 149 pmd_t pmd = *pmdp; 150 151 if (!pmd_none(pmd)) { 152 /* 153 * Clear the PMD from the page table, and 154 * increment the vmalloc sequence so others 155 * notice this change. 156 * 157 * Note: this is still racy on SMP machines. 158 */ 159 pmd_clear(pmdp); 160 init_mm.context.vmalloc_seq++; 161 162 /* 163 * Free the page table, if there was one. 164 */ 165 if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE) 166 pte_free_kernel(&init_mm, pmd_page_vaddr(pmd)); 167 } 168 169 addr += PMD_SIZE; 170 pmdp += 2; 171 } while (addr < end); 172 173 /* 174 * Ensure that the active_mm is up to date - we want to 175 * catch any use-after-iounmap cases. 176 */ 177 if (current->active_mm->context.vmalloc_seq != init_mm.context.vmalloc_seq) 178 __check_vmalloc_seq(current->active_mm); 179 180 flush_tlb_kernel_range(virt, end); 181 } 182 183 static int 184 remap_area_sections(unsigned long virt, unsigned long pfn, 185 size_t size, const struct mem_type *type) 186 { 187 unsigned long addr = virt, end = virt + size; 188 pmd_t *pmd = pmd_off_k(addr); 189 190 /* 191 * Remove and free any PTE-based mapping, and 192 * sync the current kernel mapping. 193 */ 194 unmap_area_sections(virt, size); 195 196 do { 197 pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); 198 pfn += SZ_1M >> PAGE_SHIFT; 199 pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); 200 pfn += SZ_1M >> PAGE_SHIFT; 201 flush_pmd_entry(pmd); 202 203 addr += PMD_SIZE; 204 pmd += 2; 205 } while (addr < end); 206 207 return 0; 208 } 209 210 static int 211 remap_area_supersections(unsigned long virt, unsigned long pfn, 212 size_t size, const struct mem_type *type) 213 { 214 unsigned long addr = virt, end = virt + size; 215 pmd_t *pmd = pmd_off_k(addr); 216 217 /* 218 * Remove and free any PTE-based mapping, and 219 * sync the current kernel mapping. 220 */ 221 unmap_area_sections(virt, size); 222 do { 223 unsigned long super_pmd_val, i; 224 225 super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect | 226 PMD_SECT_SUPER; 227 super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20; 228 229 for (i = 0; i < 8; i++) { 230 pmd[0] = __pmd(super_pmd_val); 231 pmd[1] = __pmd(super_pmd_val); 232 flush_pmd_entry(pmd); 233 234 addr += PMD_SIZE; 235 pmd += 2; 236 } 237 238 pfn += SUPERSECTION_SIZE >> PAGE_SHIFT; 239 } while (addr < end); 240 241 return 0; 242 } 243 #endif 244 245 static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn, 246 unsigned long offset, size_t size, unsigned int mtype, void *caller) 247 { 248 const struct mem_type *type; 249 int err; 250 unsigned long addr; 251 struct vm_struct *area; 252 phys_addr_t paddr = __pfn_to_phys(pfn); 253 254 #ifndef CONFIG_ARM_LPAE 255 /* 256 * High mappings must be supersection aligned 257 */ 258 if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK)) 259 return NULL; 260 #endif 261 262 type = get_mem_type(mtype); 263 if (!type) 264 return NULL; 265 266 /* 267 * Page align the mapping size, taking account of any offset. 268 */ 269 size = PAGE_ALIGN(offset + size); 270 271 /* 272 * Try to reuse one of the static mapping whenever possible. 273 */ 274 if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) { 275 struct static_vm *svm; 276 277 svm = find_static_vm_paddr(paddr, size, mtype); 278 if (svm) { 279 addr = (unsigned long)svm->vm.addr; 280 addr += paddr - svm->vm.phys_addr; 281 return (void __iomem *) (offset + addr); 282 } 283 } 284 285 /* 286 * Don't allow RAM to be mapped with mismatched attributes - this 287 * causes problems with ARMv6+ 288 */ 289 if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) && 290 mtype != MT_MEMORY_RW)) 291 return NULL; 292 293 area = get_vm_area_caller(size, VM_IOREMAP, caller); 294 if (!area) 295 return NULL; 296 addr = (unsigned long)area->addr; 297 area->phys_addr = paddr; 298 299 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) 300 if (DOMAIN_IO == 0 && 301 (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) || 302 cpu_is_xsc3()) && pfn >= 0x100000 && 303 !((paddr | size | addr) & ~SUPERSECTION_MASK)) { 304 area->flags |= VM_ARM_SECTION_MAPPING; 305 err = remap_area_supersections(addr, pfn, size, type); 306 } else if (!((paddr | size | addr) & ~PMD_MASK)) { 307 area->flags |= VM_ARM_SECTION_MAPPING; 308 err = remap_area_sections(addr, pfn, size, type); 309 } else 310 #endif 311 err = ioremap_page_range(addr, addr + size, paddr, 312 __pgprot(type->prot_pte)); 313 314 if (err) { 315 vunmap((void *)addr); 316 return NULL; 317 } 318 319 flush_cache_vmap(addr, addr + size); 320 return (void __iomem *) (offset + addr); 321 } 322 323 void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size, 324 unsigned int mtype, void *caller) 325 { 326 phys_addr_t last_addr; 327 unsigned long offset = phys_addr & ~PAGE_MASK; 328 unsigned long pfn = __phys_to_pfn(phys_addr); 329 330 /* 331 * Don't allow wraparound or zero size 332 */ 333 last_addr = phys_addr + size - 1; 334 if (!size || last_addr < phys_addr) 335 return NULL; 336 337 return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, 338 caller); 339 } 340 341 /* 342 * Remap an arbitrary physical address space into the kernel virtual 343 * address space. Needed when the kernel wants to access high addresses 344 * directly. 345 * 346 * NOTE! We need to allow non-page-aligned mappings too: we will obviously 347 * have to convert them into an offset in a page-aligned mapping, but the 348 * caller shouldn't need to know that small detail. 349 */ 350 void __iomem * 351 __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size, 352 unsigned int mtype) 353 { 354 return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, 355 __builtin_return_address(0)); 356 } 357 EXPORT_SYMBOL(__arm_ioremap_pfn); 358 359 void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t, 360 unsigned int, void *) = 361 __arm_ioremap_caller; 362 363 void __iomem *ioremap(resource_size_t res_cookie, size_t size) 364 { 365 return arch_ioremap_caller(res_cookie, size, MT_DEVICE, 366 __builtin_return_address(0)); 367 } 368 EXPORT_SYMBOL(ioremap); 369 370 void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size) 371 { 372 return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED, 373 __builtin_return_address(0)); 374 } 375 EXPORT_SYMBOL(ioremap_cache); 376 377 void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size) 378 { 379 return arch_ioremap_caller(res_cookie, size, MT_DEVICE_WC, 380 __builtin_return_address(0)); 381 } 382 EXPORT_SYMBOL(ioremap_wc); 383 384 /* 385 * Remap an arbitrary physical address space into the kernel virtual 386 * address space as memory. Needed when the kernel wants to execute 387 * code in external memory. This is needed for reprogramming source 388 * clocks that would affect normal memory for example. Please see 389 * CONFIG_GENERIC_ALLOCATOR for allocating external memory. 390 */ 391 void __iomem * 392 __arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached) 393 { 394 unsigned int mtype; 395 396 if (cached) 397 mtype = MT_MEMORY_RWX; 398 else 399 mtype = MT_MEMORY_RWX_NONCACHED; 400 401 return __arm_ioremap_caller(phys_addr, size, mtype, 402 __builtin_return_address(0)); 403 } 404 405 void __arm_iomem_set_ro(void __iomem *ptr, size_t size) 406 { 407 set_memory_ro((unsigned long)ptr, PAGE_ALIGN(size) / PAGE_SIZE); 408 } 409 410 void *arch_memremap_wb(phys_addr_t phys_addr, size_t size) 411 { 412 return (__force void *)arch_ioremap_caller(phys_addr, size, 413 MT_MEMORY_RW, 414 __builtin_return_address(0)); 415 } 416 417 void __iounmap(volatile void __iomem *io_addr) 418 { 419 void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr); 420 struct static_vm *svm; 421 422 /* If this is a static mapping, we must leave it alone */ 423 svm = find_static_vm_vaddr(addr); 424 if (svm) 425 return; 426 427 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) 428 { 429 struct vm_struct *vm; 430 431 vm = find_vm_area(addr); 432 433 /* 434 * If this is a section based mapping we need to handle it 435 * specially as the VM subsystem does not know how to handle 436 * such a beast. 437 */ 438 if (vm && (vm->flags & VM_ARM_SECTION_MAPPING)) 439 unmap_area_sections((unsigned long)vm->addr, vm->size); 440 } 441 #endif 442 443 vunmap(addr); 444 } 445 446 void (*arch_iounmap)(volatile void __iomem *) = __iounmap; 447 448 void iounmap(volatile void __iomem *cookie) 449 { 450 arch_iounmap(cookie); 451 } 452 EXPORT_SYMBOL(iounmap); 453 454 #ifdef CONFIG_PCI 455 static int pci_ioremap_mem_type = MT_DEVICE; 456 457 void pci_ioremap_set_mem_type(int mem_type) 458 { 459 pci_ioremap_mem_type = mem_type; 460 } 461 462 int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr) 463 { 464 BUG_ON(offset + SZ_64K - 1 > IO_SPACE_LIMIT); 465 466 return ioremap_page_range(PCI_IO_VIRT_BASE + offset, 467 PCI_IO_VIRT_BASE + offset + SZ_64K, 468 phys_addr, 469 __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte)); 470 } 471 EXPORT_SYMBOL_GPL(pci_ioremap_io); 472 473 void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size) 474 { 475 return arch_ioremap_caller(res_cookie, size, MT_UNCACHED, 476 __builtin_return_address(0)); 477 } 478 EXPORT_SYMBOL_GPL(pci_remap_cfgspace); 479 #endif 480 481 /* 482 * Must be called after early_fixmap_init 483 */ 484 void __init early_ioremap_init(void) 485 { 486 early_ioremap_setup(); 487 } 488