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/system_info.h>
  40
  41 #include <asm/mach/map.h>
  42 #include <asm/mach/pci.h>
  43 #include "mm.h"
  44
  45
  46 LIST_HEAD(static_vmlist);
  47
  48 static struct static_vm *find_static_vm_paddr(phys_addr_t paddr,
  49                         size_t size, unsigned int mtype)
  50 {
  51         struct static_vm *svm;
  52         struct vm_struct *vm;
  53
  54         list_for_each_entry(svm, &static_vmlist, list) {
  55                 vm = &svm->vm;
  56                 if (!(vm->flags & VM_ARM_STATIC_MAPPING))
  57                         continue;
  58                 if ((vm->flags & VM_ARM_MTYPE_MASK) != VM_ARM_MTYPE(mtype))
  59                         continue;
  60
  61                 if (vm->phys_addr > paddr ||
  62                         paddr + size - 1 > vm->phys_addr + vm->size - 1)
  63                         continue;
  64
  65                 return svm;
  66         }
  67
  68         return NULL;
  69 }
  70
  71 struct static_vm *find_static_vm_vaddr(void *vaddr)
  72 {
  73         struct static_vm *svm;
  74         struct vm_struct *vm;
  75
  76         list_for_each_entry(svm, &static_vmlist, list) {
  77                 vm = &svm->vm;
  78
  79                 /* static_vmlist is ascending order */
  80                 if (vm->addr > vaddr)
  81                         break;
  82
  83                 if (vm->addr <= vaddr && vm->addr + vm->size > vaddr)
  84                         return svm;
  85         }
  86
  87         return NULL;
  88 }
  89
  90 void __init add_static_vm_early(struct static_vm *svm)
  91 {
  92         struct static_vm *curr_svm;
  93         struct vm_struct *vm;
  94         void *vaddr;
  95
  96         vm = &svm->vm;
  97         vm_area_add_early(vm);
  98         vaddr = vm->addr;
  99
 100         list_for_each_entry(curr_svm, &static_vmlist, list) {
 101                 vm = &curr_svm->vm;
 102
 103                 if (vm->addr > vaddr)
 104                         break;
 105         }
 106         list_add_tail(&svm->list, &curr_svm->list);
 107 }
 108
 109 int ioremap_page(unsigned long virt, unsigned long phys,
 110                  const struct mem_type *mtype)
 111 {
 112         return ioremap_page_range(virt, virt + PAGE_SIZE, phys,
 113                                   __pgprot(mtype->prot_pte));
 114 }
 115 EXPORT_SYMBOL(ioremap_page);
 116
 117 void __check_vmalloc_seq(struct mm_struct *mm)
 118 {
 119         unsigned int seq;
 120
 121         do {
 122                 seq = init_mm.context.vmalloc_seq;
 123                 memcpy(pgd_offset(mm, VMALLOC_START),
 124                        pgd_offset_k(VMALLOC_START),
 125                        sizeof(pgd_t) * (pgd_index(VMALLOC_END) -
 126                                         pgd_index(VMALLOC_START)));
 127                 mm->context.vmalloc_seq = seq;
 128         } while (seq != init_mm.context.vmalloc_seq);
 129 }
 130
 131 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
 132 /*
 133  * Section support is unsafe on SMP - If you iounmap and ioremap a region,
 134  * the other CPUs will not see this change until their next context switch.
 135  * Meanwhile, (eg) if an interrupt comes in on one of those other CPUs
 136  * which requires the new ioremap'd region to be referenced, the CPU will
 137  * reference the _old_ region.
 138  *
 139  * Note that get_vm_area_caller() allocates a guard 4K page, so we need to
 140  * mask the size back to 1MB aligned or we will overflow in the loop below.
 141  */
 142 static void unmap_area_sections(unsigned long virt, unsigned long size)
 143 {
 144         unsigned long addr = virt, end = virt + (size & ~(SZ_1M - 1));
 145         pgd_t *pgd;
 146         pud_t *pud;
 147         pmd_t *pmdp;
 148
 149         flush_cache_vunmap(addr, end);
 150         pgd = pgd_offset_k(addr);
 151         pud = pud_offset(pgd, addr);
 152         pmdp = pmd_offset(pud, addr);
 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                         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         if (current->active_mm->context.vmalloc_seq != init_mm.context.vmalloc_seq)
 183                 __check_vmalloc_seq(current->active_mm);
 184
 185         flush_tlb_kernel_range(virt, end);
 186 }
 187
 188 static int
 189 remap_area_sections(unsigned long virt, unsigned long pfn,
 190                     size_t size, const struct mem_type *type)
 191 {
 192         unsigned long addr = virt, end = virt + size;
 193         pgd_t *pgd;
 194         pud_t *pud;
 195         pmd_t *pmd;
 196
 197         /*
 198          * Remove and free any PTE-based mapping, and
 199          * sync the current kernel mapping.
 200          */
 201         unmap_area_sections(virt, size);
 202
 203         pgd = pgd_offset_k(addr);
 204         pud = pud_offset(pgd, addr);
 205         pmd = pmd_offset(pud, addr);
 206         do {
 207                 pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
 208                 pfn += SZ_1M >> PAGE_SHIFT;
 209                 pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
 210                 pfn += SZ_1M >> PAGE_SHIFT;
 211                 flush_pmd_entry(pmd);
 212
 213                 addr += PMD_SIZE;
 214                 pmd += 2;
 215         } while (addr < end);
 216
 217         return 0;
 218 }
 219
 220 static int
 221 remap_area_supersections(unsigned long virt, unsigned long pfn,
 222                          size_t size, const struct mem_type *type)
 223 {
 224         unsigned long addr = virt, end = virt + size;
 225         pgd_t *pgd;
 226         pud_t *pud;
 227         pmd_t *pmd;
 228
 229         /*
 230          * Remove and free any PTE-based mapping, and
 231          * sync the current kernel mapping.
 232          */
 233         unmap_area_sections(virt, size);
 234
 235         pgd = pgd_offset_k(virt);
 236         pud = pud_offset(pgd, addr);
 237         pmd = pmd_offset(pud, addr);
 238         do {
 239                 unsigned long super_pmd_val, i;
 240
 241                 super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect |
 242                                 PMD_SECT_SUPER;
 243                 super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;
 244
 245                 for (i = 0; i < 8; i++) {
 246                         pmd[0] = __pmd(super_pmd_val);
 247                         pmd[1] = __pmd(super_pmd_val);
 248                         flush_pmd_entry(pmd);
 249
 250                         addr += PMD_SIZE;
 251                         pmd += 2;
 252                 }
 253
 254                 pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
 255         } while (addr < end);
 256
 257         return 0;
 258 }
 259 #endif
 260
 261 static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
 262         unsigned long offset, size_t size, unsigned int mtype, void *caller)
 263 {
 264         const struct mem_type *type;
 265         int err;
 266         unsigned long addr;
 267         struct vm_struct *area;
 268         phys_addr_t paddr = __pfn_to_phys(pfn);
 269
 270 #ifndef CONFIG_ARM_LPAE
 271         /*
 272          * High mappings must be supersection aligned
 273          */
 274         if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK))
 275                 return NULL;
 276 #endif
 277
 278         type = get_mem_type(mtype);
 279         if (!type)
 280                 return NULL;
 281
 282         /*
 283          * Page align the mapping size, taking account of any offset.
 284          */
 285         size = PAGE_ALIGN(offset + size);
 286
 287         /*
 288          * Try to reuse one of the static mapping whenever possible.
 289          */
 290         if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) {
 291                 struct static_vm *svm;
 292
 293                 svm = find_static_vm_paddr(paddr, size, mtype);
 294                 if (svm) {
 295                         addr = (unsigned long)svm->vm.addr;
 296                         addr += paddr - svm->vm.phys_addr;
 297                         return (void __iomem *) (offset + addr);
 298                 }
 299         }
 300
 301         /*
 302          * Don't allow RAM to be mapped with mismatched attributes - this
 303          * causes problems with ARMv6+
 304          */
 305         if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) &&
 306                     mtype != MT_MEMORY_RW))
 307                 return NULL;
 308
 309         area = get_vm_area_caller(size, VM_IOREMAP, caller);
 310         if (!area)
 311                 return NULL;
 312         addr = (unsigned long)area->addr;
 313         area->phys_addr = paddr;
 314
 315 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
 316         if (DOMAIN_IO == 0 &&
 317             (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
 318                cpu_is_xsc3()) && pfn >= 0x100000 &&
 319                !((paddr | size | addr) & ~SUPERSECTION_MASK)) {
 320                 area->flags |= VM_ARM_SECTION_MAPPING;
 321                 err = remap_area_supersections(addr, pfn, size, type);
 322         } else if (!((paddr | size | addr) & ~PMD_MASK)) {
 323                 area->flags |= VM_ARM_SECTION_MAPPING;
 324                 err = remap_area_sections(addr, pfn, size, type);
 325         } else
 326 #endif
 327                 err = ioremap_page_range(addr, addr + size, paddr,
 328                                          __pgprot(type->prot_pte));
 329
 330         if (err) {
 331                 vunmap((void *)addr);
 332                 return NULL;
 333         }
 334
 335         flush_cache_vmap(addr, addr + size);
 336         return (void __iomem *) (offset + addr);
 337 }
 338
 339 void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size,
 340         unsigned int mtype, void *caller)
 341 {
 342         phys_addr_t last_addr;
 343         unsigned long offset = phys_addr & ~PAGE_MASK;
 344         unsigned long pfn = __phys_to_pfn(phys_addr);
 345
 346         /*
 347          * Don't allow wraparound or zero size
 348          */
 349         last_addr = phys_addr + size - 1;
 350         if (!size || last_addr < phys_addr)
 351                 return NULL;
 352
 353         return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
 354                         caller);
 355 }
 356
 357 /*
 358  * Remap an arbitrary physical address space into the kernel virtual
 359  * address space. Needed when the kernel wants to access high addresses
 360  * directly.
 361  *
 362  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 363  * have to convert them into an offset in a page-aligned mapping, but the
 364  * caller shouldn't need to know that small detail.
 365  */
 366 void __iomem *
 367 __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
 368                   unsigned int mtype)
 369 {
 370         return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
 371                                         __builtin_return_address(0));
 372 }
 373 EXPORT_SYMBOL(__arm_ioremap_pfn);
 374
 375 void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t,
 376                                       unsigned int, void *) =
 377         __arm_ioremap_caller;
 378
 379 void __iomem *ioremap(resource_size_t res_cookie, size_t size)
 380 {
 381         return arch_ioremap_caller(res_cookie, size, MT_DEVICE,
 382                                    __builtin_return_address(0));
 383 }
 384 EXPORT_SYMBOL(ioremap);
 385
 386 void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size)
 387         __alias(ioremap_cached);
 388
 389 void __iomem *ioremap_cached(resource_size_t res_cookie, size_t size)
 390 {
 391         return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED,
 392                                    __builtin_return_address(0));
 393 }
 394 EXPORT_SYMBOL(ioremap_cache);
 395 EXPORT_SYMBOL(ioremap_cached);
 396
 397 void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size)
 398 {
 399         return arch_ioremap_caller(res_cookie, size, MT_DEVICE_WC,
 400                                    __builtin_return_address(0));
 401 }
 402 EXPORT_SYMBOL(ioremap_wc);
 403
 404 /*
 405  * Remap an arbitrary physical address space into the kernel virtual
 406  * address space as memory. Needed when the kernel wants to execute
 407  * code in external memory. This is needed for reprogramming source
 408  * clocks that would affect normal memory for example. Please see
 409  * CONFIG_GENERIC_ALLOCATOR for allocating external memory.
 410  */
 411 void __iomem *
 412 __arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached)
 413 {
 414         unsigned int mtype;
 415
 416         if (cached)
 417                 mtype = MT_MEMORY_RWX;
 418         else
 419                 mtype = MT_MEMORY_RWX_NONCACHED;
 420
 421         return __arm_ioremap_caller(phys_addr, size, mtype,
 422                         __builtin_return_address(0));
 423 }
 424
 425 void *arch_memremap_wb(phys_addr_t phys_addr, size_t size)
 426 {
 427         return (__force void *)arch_ioremap_caller(phys_addr, size,
 428                                                    MT_MEMORY_RW,
 429                                                    __builtin_return_address(0));
 430 }
 431
 432 void __iounmap(volatile void __iomem *io_addr)
 433 {
 434         void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
 435         struct static_vm *svm;
 436
 437         /* If this is a static mapping, we must leave it alone */
 438         svm = find_static_vm_vaddr(addr);
 439         if (svm)
 440                 return;
 441
 442 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
 443         {
 444                 struct vm_struct *vm;
 445
 446                 vm = find_vm_area(addr);
 447
 448                 /*
 449                  * If this is a section based mapping we need to handle it
 450                  * specially as the VM subsystem does not know how to handle
 451                  * such a beast.
 452                  */
 453                 if (vm && (vm->flags & VM_ARM_SECTION_MAPPING))
 454                         unmap_area_sections((unsigned long)vm->addr, vm->size);
 455         }
 456 #endif
 457
 458         vunmap(addr);
 459 }
 460
 461 void (*arch_iounmap)(volatile void __iomem *) = __iounmap;
 462
 463 void iounmap(volatile void __iomem *cookie)
 464 {
 465         arch_iounmap(cookie);
 466 }
 467 EXPORT_SYMBOL(iounmap);
 468
 469 #ifdef CONFIG_PCI
 470 static int pci_ioremap_mem_type = MT_DEVICE;
 471
 472 void pci_ioremap_set_mem_type(int mem_type)
 473 {
 474         pci_ioremap_mem_type = mem_type;
 475 }
 476
 477 int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr)
 478 {
 479         BUG_ON(offset + SZ_64K - 1 > IO_SPACE_LIMIT);
 480
 481         return ioremap_page_range(PCI_IO_VIRT_BASE + offset,
 482                                   PCI_IO_VIRT_BASE + offset + SZ_64K,
 483                                   phys_addr,
 484                                   __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte));
 485 }
 486 EXPORT_SYMBOL_GPL(pci_ioremap_io);
 487
 488 void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size)
 489 {
 490         return arch_ioremap_caller(res_cookie, size, MT_UNCACHED,
 491                                    __builtin_return_address(0));
 492 }
 493 EXPORT_SYMBOL_GPL(pci_remap_cfgspace);
 494 #endif
 495
 496 /*
 497  * Must be called after early_fixmap_init
 498  */
 499 void __init early_ioremap_init(void)
 500 {
 501         early_ioremap_setup();
 502 }
 503
 504 bool arch_memremap_can_ram_remap(resource_size_t offset, size_t size,
 505                                  unsigned long flags)
 506 {
 507         unsigned long pfn = PHYS_PFN(offset);
 508
 509         return memblock_is_map_memory(pfn);
 510 }