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