arch/arm/mm/ioremap.c

   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_remap_iospace(const struct resource *res, phys_addr_t phys_addr)
 463 {
 464         unsigned long vaddr = (unsigned long)PCI_IOBASE + res->start;
 465
 466         if (!(res->flags & IORESOURCE_IO))
 467                 return -EINVAL;
 468
 469         if (res->end > IO_SPACE_LIMIT)
 470                 return -EINVAL;
 471
 472         return ioremap_page_range(vaddr, vaddr + resource_size(res), phys_addr,
 473                                   __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte));
 474 }
 475 EXPORT_SYMBOL(pci_remap_iospace);
 476
 477 void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size)
 478 {
 479         return arch_ioremap_caller(res_cookie, size, MT_UNCACHED,
 480                                    __builtin_return_address(0));
 481 }
 482 EXPORT_SYMBOL_GPL(pci_remap_cfgspace);
 483 #endif
 484
 485 /*
 486  * Must be called after early_fixmap_init
 487  */
 488 void __init early_ioremap_init(void)
 489 {
 490         early_ioremap_setup();
 491 }