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 int seq; 121 122 do { 123 seq = atomic_read(&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 /* 129 * Use a store-release so that other CPUs that observe the 130 * counter's new value are guaranteed to see the results of the 131 * memcpy as well. 132 */ 133 atomic_set_release(&mm->context.vmalloc_seq, seq); 134 } while (seq != atomic_read(&init_mm.context.vmalloc_seq)); 135 } 136 137 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) 138 /* 139 * Section support is unsafe on SMP - If you iounmap and ioremap a region, 140 * the other CPUs will not see this change until their next context switch. 141 * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs 142 * which requires the new ioremap'd region to be referenced, the CPU will 143 * reference the _old_ region. 144 * 145 * Note that get_vm_area_caller() allocates a guard 4K page, so we need to 146 * mask the size back to 1MB aligned or we will overflow in the loop below. 147 */ 148 static void unmap_area_sections(unsigned long virt, unsigned long size) 149 { 150 unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1)); 151 pmd_t *pmdp = pmd_off_k(addr); 152 153 do { 154 pmd_t pmd = *pmdp; 155 156 if (!pmd_none(pmd)) { 157 /* 158 * Clear the PMD from the page table, and 159 * increment the vmalloc sequence so others 160 * notice this change. 161 * 162 * Note: this is still racy on SMP machines. 163 */ 164 pmd_clear(pmdp); 165 atomic_inc_return_release(&init_mm.context.vmalloc_seq); 166 167 /* 168 * Free the page table, if there was one. 169 */ 170 if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE) 171 pte_free_kernel(&init_mm, pmd_page_vaddr(pmd)); 172 } 173 174 addr += PMD_SIZE; 175 pmdp += 2; 176 } while (addr < end); 177 178 /* 179 * Ensure that the active_mm is up to date - we want to 180 * catch any use-after-iounmap cases. 181 */ 182 check_vmalloc_seq(current->active_mm); 183 184 flush_tlb_kernel_range(virt, end); 185 } 186 187 static int 188 remap_area_sections(unsigned long virt, unsigned long pfn, 189 size_t size, const struct mem_type *type) 190 { 191 unsigned long addr = virt, end = virt + size; 192 pmd_t *pmd = pmd_off_k(addr); 193 194 /* 195 * Remove and free any PTE-based mapping, and 196 * sync the current kernel mapping. 197 */ 198 unmap_area_sections(virt, size); 199 200 do { 201 pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); 202 pfn += SZ_1M >> PAGE_SHIFT; 203 pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect); 204 pfn += SZ_1M >> PAGE_SHIFT; 205 flush_pmd_entry(pmd); 206 207 addr += PMD_SIZE; 208 pmd += 2; 209 } while (addr < end); 210 211 return 0; 212 } 213 214 static int 215 remap_area_supersections(unsigned long virt, unsigned long pfn, 216 size_t size, const struct mem_type *type) 217 { 218 unsigned long addr = virt, end = virt + size; 219 pmd_t *pmd = pmd_off_k(addr); 220 221 /* 222 * Remove and free any PTE-based mapping, and 223 * sync the current kernel mapping. 224 */ 225 unmap_area_sections(virt, size); 226 do { 227 unsigned long super_pmd_val, i; 228 229 super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect | 230 PMD_SECT_SUPER; 231 super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20; 232 233 for (i = 0; i < 8; i++) { 234 pmd[0] = __pmd(super_pmd_val); 235 pmd[1] = __pmd(super_pmd_val); 236 flush_pmd_entry(pmd); 237 238 addr += PMD_SIZE; 239 pmd += 2; 240 } 241 242 pfn += SUPERSECTION_SIZE >> PAGE_SHIFT; 243 } while (addr < end); 244 245 return 0; 246 } 247 #endif 248 249 static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn, 250 unsigned long offset, size_t size, unsigned int mtype, void *caller) 251 { 252 const struct mem_type *type; 253 int err; 254 unsigned long addr; 255 struct vm_struct *area; 256 phys_addr_t paddr = __pfn_to_phys(pfn); 257 258 #ifndef CONFIG_ARM_LPAE 259 /* 260 * High mappings must be supersection aligned 261 */ 262 if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK)) 263 return NULL; 264 #endif 265 266 type = get_mem_type(mtype); 267 if (!type) 268 return NULL; 269 270 /* 271 * Page align the mapping size, taking account of any offset. 272 */ 273 size = PAGE_ALIGN(offset + size); 274 275 /* 276 * Try to reuse one of the static mapping whenever possible. 277 */ 278 if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) { 279 struct static_vm *svm; 280 281 svm = find_static_vm_paddr(paddr, size, mtype); 282 if (svm) { 283 addr = (unsigned long)svm->vm.addr; 284 addr += paddr - svm->vm.phys_addr; 285 return (void __iomem *) (offset + addr); 286 } 287 } 288 289 /* 290 * Don't allow RAM to be mapped with mismatched attributes - this 291 * causes problems with ARMv6+ 292 */ 293 if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) && 294 mtype != MT_MEMORY_RW)) 295 return NULL; 296 297 area = get_vm_area_caller(size, VM_IOREMAP, caller); 298 if (!area) 299 return NULL; 300 addr = (unsigned long)area->addr; 301 area->phys_addr = paddr; 302 303 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) 304 if (DOMAIN_IO == 0 && 305 (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) || 306 cpu_is_xsc3()) && pfn >= 0x100000 && 307 !((paddr | size | addr) & ~SUPERSECTION_MASK)) { 308 area->flags |= VM_ARM_SECTION_MAPPING; 309 err = remap_area_supersections(addr, pfn, size, type); 310 } else if (!((paddr | size | addr) & ~PMD_MASK)) { 311 area->flags |= VM_ARM_SECTION_MAPPING; 312 err = remap_area_sections(addr, pfn, size, type); 313 } else 314 #endif 315 err = ioremap_page_range(addr, addr + size, paddr, 316 __pgprot(type->prot_pte)); 317 318 if (err) { 319 vunmap((void *)addr); 320 return NULL; 321 } 322 323 flush_cache_vmap(addr, addr + size); 324 return (void __iomem *) (offset + addr); 325 } 326 327 void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size, 328 unsigned int mtype, void *caller) 329 { 330 phys_addr_t last_addr; 331 unsigned long offset = phys_addr & ~PAGE_MASK; 332 unsigned long pfn = __phys_to_pfn(phys_addr); 333 334 /* 335 * Don't allow wraparound or zero size 336 */ 337 last_addr = phys_addr + size - 1; 338 if (!size || last_addr < phys_addr) 339 return NULL; 340 341 return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, 342 caller); 343 } 344 345 /* 346 * Remap an arbitrary physical address space into the kernel virtual 347 * address space. Needed when the kernel wants to access high addresses 348 * directly. 349 * 350 * NOTE! We need to allow non-page-aligned mappings too: we will obviously 351 * have to convert them into an offset in a page-aligned mapping, but the 352 * caller shouldn't need to know that small detail. 353 */ 354 void __iomem * 355 __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size, 356 unsigned int mtype) 357 { 358 return __arm_ioremap_pfn_caller(pfn, offset, size, mtype, 359 __builtin_return_address(0)); 360 } 361 EXPORT_SYMBOL(__arm_ioremap_pfn); 362 363 void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t, 364 unsigned int, void *) = 365 __arm_ioremap_caller; 366 367 void __iomem *ioremap(resource_size_t res_cookie, size_t size) 368 { 369 return arch_ioremap_caller(res_cookie, size, MT_DEVICE, 370 __builtin_return_address(0)); 371 } 372 EXPORT_SYMBOL(ioremap); 373 374 void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size) 375 { 376 return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED, 377 __builtin_return_address(0)); 378 } 379 EXPORT_SYMBOL(ioremap_cache); 380 381 void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size) 382 { 383 return arch_ioremap_caller(res_cookie, size, MT_DEVICE_WC, 384 __builtin_return_address(0)); 385 } 386 EXPORT_SYMBOL(ioremap_wc); 387 388 /* 389 * Remap an arbitrary physical address space into the kernel virtual 390 * address space as memory. Needed when the kernel wants to execute 391 * code in external memory. This is needed for reprogramming source 392 * clocks that would affect normal memory for example. Please see 393 * CONFIG_GENERIC_ALLOCATOR for allocating external memory. 394 */ 395 void __iomem * 396 __arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached) 397 { 398 unsigned int mtype; 399 400 if (cached) 401 mtype = MT_MEMORY_RWX; 402 else 403 mtype = MT_MEMORY_RWX_NONCACHED; 404 405 return __arm_ioremap_caller(phys_addr, size, mtype, 406 __builtin_return_address(0)); 407 } 408 409 void __arm_iomem_set_ro(void __iomem *ptr, size_t size) 410 { 411 set_memory_ro((unsigned long)ptr, PAGE_ALIGN(size) / PAGE_SIZE); 412 } 413 414 void *arch_memremap_wb(phys_addr_t phys_addr, size_t size) 415 { 416 return (__force void *)arch_ioremap_caller(phys_addr, size, 417 MT_MEMORY_RW, 418 __builtin_return_address(0)); 419 } 420 421 void __iounmap(volatile void __iomem *io_addr) 422 { 423 void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr); 424 struct static_vm *svm; 425 426 /* If this is a static mapping, we must leave it alone */ 427 svm = find_static_vm_vaddr(addr); 428 if (svm) 429 return; 430 431 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE) 432 { 433 struct vm_struct *vm; 434 435 vm = find_vm_area(addr); 436 437 /* 438 * If this is a section based mapping we need to handle it 439 * specially as the VM subsystem does not know how to handle 440 * such a beast. 441 */ 442 if (vm && (vm->flags & VM_ARM_SECTION_MAPPING)) 443 unmap_area_sections((unsigned long)vm->addr, vm->size); 444 } 445 #endif 446 447 vunmap(addr); 448 } 449 450 void (*arch_iounmap)(volatile void __iomem *) = __iounmap; 451 452 void iounmap(volatile void __iomem *cookie) 453 { 454 arch_iounmap(cookie); 455 } 456 EXPORT_SYMBOL(iounmap); 457 458 #ifdef CONFIG_PCI 459 static int pci_ioremap_mem_type = MT_DEVICE; 460 461 void pci_ioremap_set_mem_type(int mem_type) 462 { 463 pci_ioremap_mem_type = mem_type; 464 } 465 466 int pci_remap_iospace(const struct resource *res, phys_addr_t phys_addr) 467 { 468 unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start; 469 470 if (!(res->flags & IORESOURCE_IO)) 471 return -EINVAL; 472 473 if (res->end > IO_SPACE_LIMIT) 474 return -EINVAL; 475 476 return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr, 477 __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte)); 478 } 479 EXPORT_SYMBOL(pci_remap_iospace); 480 481 void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size) 482 { 483 return arch_ioremap_caller(res_cookie, size, MT_UNCACHED, 484 __builtin_return_address(0)); 485 } 486 EXPORT_SYMBOL_GPL(pci_remap_cfgspace); 487 #endif 488 489 /* 490 * Must be called after early_fixmap_init 491 */ 492 void __init early_ioremap_init(void) 493 { 494 early_ioremap_setup(); 495 } 496