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         pmd_t *pmdp = pmd_off_k(addr);
 146
 147         do {
 148                 pmd_t pmd = *pmdp;
 149
 150                 if (!pmd_none(pmd)) {
 151                         /*
 152                          * Clear the PMD from the page table, and
 153                          * increment the vmalloc sequence so others
 154                          * notice this change.
 155                          *
 156                          * Note: this is still racy on SMP machines.
 157                          */
 158                         pmd_clear(pmdp);
 159                         init_mm.context.vmalloc_seq++;
 160
 161                         /*
 162                          * Free the page table, if there was one.
 163                          */
 164                         if ((pmd_val(pmd) & PMD_TYPE_MASK) == PMD_TYPE_TABLE)
 165                                 pte_free_kernel(&init_mm, pmd_page_vaddr(pmd));
 166                 }
 167
 168                 addr += PMD_SIZE;
 169                 pmdp += 2;
 170         } while (addr < end);
 171
 172         /*
 173          * Ensure that the active_mm is up to date - we want to
 174          * catch any use-after-iounmap cases.
 175          */
 176         if (current->active_mm->context.vmalloc_seq != init_mm.context.vmalloc_seq)
 177                 __check_vmalloc_seq(current->active_mm);
 178
 179         flush_tlb_kernel_range(virt, end);
 180 }
 181
 182 static int
 183 remap_area_sections(unsigned long virt, unsigned long pfn,
 184                     size_t size, const struct mem_type *type)
 185 {
 186         unsigned long addr = virt, end = virt + size;
 187         pmd_t *pmd = pmd_off_k(addr);
 188
 189         /*
 190          * Remove and free any PTE-based mapping, and
 191          * sync the current kernel mapping.
 192          */
 193         unmap_area_sections(virt, size);
 194
 195         do {
 196                 pmd[0] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
 197                 pfn += SZ_1M >> PAGE_SHIFT;
 198                 pmd[1] = __pmd(__pfn_to_phys(pfn) | type->prot_sect);
 199                 pfn += SZ_1M >> PAGE_SHIFT;
 200                 flush_pmd_entry(pmd);
 201
 202                 addr += PMD_SIZE;
 203                 pmd += 2;
 204         } while (addr < end);
 205
 206         return 0;
 207 }
 208
 209 static int
 210 remap_area_supersections(unsigned long virt, unsigned long pfn,
 211                          size_t size, const struct mem_type *type)
 212 {
 213         unsigned long addr = virt, end = virt + size;
 214         pmd_t *pmd = pmd_off_k(addr);
 215
 216         /*
 217          * Remove and free any PTE-based mapping, and
 218          * sync the current kernel mapping.
 219          */
 220         unmap_area_sections(virt, size);
 221         do {
 222                 unsigned long super_pmd_val, i;
 223
 224                 super_pmd_val = __pfn_to_phys(pfn) | type->prot_sect |
 225                                 PMD_SECT_SUPER;
 226                 super_pmd_val |= ((pfn >> (32 - PAGE_SHIFT)) & 0xf) << 20;
 227
 228                 for (i = 0; i < 8; i++) {
 229                         pmd[0] = __pmd(super_pmd_val);
 230                         pmd[1] = __pmd(super_pmd_val);
 231                         flush_pmd_entry(pmd);
 232
 233                         addr += PMD_SIZE;
 234                         pmd += 2;
 235                 }
 236
 237                 pfn += SUPERSECTION_SIZE >> PAGE_SHIFT;
 238         } while (addr < end);
 239
 240         return 0;
 241 }
 242 #endif
 243
 244 static void __iomem * __arm_ioremap_pfn_caller(unsigned long pfn,
 245         unsigned long offset, size_t size, unsigned int mtype, void *caller)
 246 {
 247         const struct mem_type *type;
 248         int err;
 249         unsigned long addr;
 250         struct vm_struct *area;
 251         phys_addr_t paddr = __pfn_to_phys(pfn);
 252
 253 #ifndef CONFIG_ARM_LPAE
 254         /*
 255          * High mappings must be supersection aligned
 256          */
 257         if (pfn >= 0x100000 && (paddr & ~SUPERSECTION_MASK))
 258                 return NULL;
 259 #endif
 260
 261         type = get_mem_type(mtype);
 262         if (!type)
 263                 return NULL;
 264
 265         /*
 266          * Page align the mapping size, taking account of any offset.
 267          */
 268         size = PAGE_ALIGN(offset + size);
 269
 270         /*
 271          * Try to reuse one of the static mapping whenever possible.
 272          */
 273         if (size && !(sizeof(phys_addr_t) == 4 && pfn >= 0x100000)) {
 274                 struct static_vm *svm;
 275
 276                 svm = find_static_vm_paddr(paddr, size, mtype);
 277                 if (svm) {
 278                         addr = (unsigned long)svm->vm.addr;
 279                         addr += paddr - svm->vm.phys_addr;
 280                         return (void __iomem *) (offset + addr);
 281                 }
 282         }
 283
 284         /*
 285          * Don't allow RAM to be mapped with mismatched attributes - this
 286          * causes problems with ARMv6+
 287          */
 288         if (WARN_ON(memblock_is_map_memory(PFN_PHYS(pfn)) &&
 289                     mtype != MT_MEMORY_RW))
 290                 return NULL;
 291
 292         area = get_vm_area_caller(size, VM_IOREMAP, caller);
 293         if (!area)
 294                 return NULL;
 295         addr = (unsigned long)area->addr;
 296         area->phys_addr = paddr;
 297
 298 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
 299         if (DOMAIN_IO == 0 &&
 300             (((cpu_architecture() >= CPU_ARCH_ARMv6) && (get_cr() & CR_XP)) ||
 301                cpu_is_xsc3()) && pfn >= 0x100000 &&
 302                !((paddr | size | addr) & ~SUPERSECTION_MASK)) {
 303                 area->flags |= VM_ARM_SECTION_MAPPING;
 304                 err = remap_area_supersections(addr, pfn, size, type);
 305         } else if (!((paddr | size | addr) & ~PMD_MASK)) {
 306                 area->flags |= VM_ARM_SECTION_MAPPING;
 307                 err = remap_area_sections(addr, pfn, size, type);
 308         } else
 309 #endif
 310                 err = ioremap_page_range(addr, addr + size, paddr,
 311                                          __pgprot(type->prot_pte));
 312
 313         if (err) {
 314                 vunmap((void *)addr);
 315                 return NULL;
 316         }
 317
 318         flush_cache_vmap(addr, addr + size);
 319         return (void __iomem *) (offset + addr);
 320 }
 321
 322 void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size,
 323         unsigned int mtype, void *caller)
 324 {
 325         phys_addr_t last_addr;
 326         unsigned long offset = phys_addr & ~PAGE_MASK;
 327         unsigned long pfn = __phys_to_pfn(phys_addr);
 328
 329         /*
 330          * Don't allow wraparound or zero size
 331          */
 332         last_addr = phys_addr + size - 1;
 333         if (!size || last_addr < phys_addr)
 334                 return NULL;
 335
 336         return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
 337                         caller);
 338 }
 339
 340 /*
 341  * Remap an arbitrary physical address space into the kernel virtual
 342  * address space. Needed when the kernel wants to access high addresses
 343  * directly.
 344  *
 345  * NOTE! We need to allow non-page-aligned mappings too: we will obviously
 346  * have to convert them into an offset in a page-aligned mapping, but the
 347  * caller shouldn't need to know that small detail.
 348  */
 349 void __iomem *
 350 __arm_ioremap_pfn(unsigned long pfn, unsigned long offset, size_t size,
 351                   unsigned int mtype)
 352 {
 353         return __arm_ioremap_pfn_caller(pfn, offset, size, mtype,
 354                                         __builtin_return_address(0));
 355 }
 356 EXPORT_SYMBOL(__arm_ioremap_pfn);
 357
 358 void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t,
 359                                       unsigned int, void *) =
 360         __arm_ioremap_caller;
 361
 362 void __iomem *ioremap(resource_size_t res_cookie, size_t size)
 363 {
 364         return arch_ioremap_caller(res_cookie, size, MT_DEVICE,
 365                                    __builtin_return_address(0));
 366 }
 367 EXPORT_SYMBOL(ioremap);
 368
 369 void __iomem *ioremap_cache(resource_size_t res_cookie, size_t size)
 370 {
 371         return arch_ioremap_caller(res_cookie, size, MT_DEVICE_CACHED,
 372                                    __builtin_return_address(0));
 373 }
 374 EXPORT_SYMBOL(ioremap_cache);
 375
 376 void __iomem *ioremap_wc(resource_size_t res_cookie, size_t size)
 377 {
 378         return arch_ioremap_caller(res_cookie, size, MT_DEVICE_WC,
 379                                    __builtin_return_address(0));
 380 }
 381 EXPORT_SYMBOL(ioremap_wc);
 382
 383 /*
 384  * Remap an arbitrary physical address space into the kernel virtual
 385  * address space as memory. Needed when the kernel wants to execute
 386  * code in external memory. This is needed for reprogramming source
 387  * clocks that would affect normal memory for example. Please see
 388  * CONFIG_GENERIC_ALLOCATOR for allocating external memory.
 389  */
 390 void __iomem *
 391 __arm_ioremap_exec(phys_addr_t phys_addr, size_t size, bool cached)
 392 {
 393         unsigned int mtype;
 394
 395         if (cached)
 396                 mtype = MT_MEMORY_RWX;
 397         else
 398                 mtype = MT_MEMORY_RWX_NONCACHED;
 399
 400         return __arm_ioremap_caller(phys_addr, size, mtype,
 401                         __builtin_return_address(0));
 402 }
 403
 404 void *arch_memremap_wb(phys_addr_t phys_addr, size_t size)
 405 {
 406         return (__force void *)arch_ioremap_caller(phys_addr, size,
 407                                                    MT_MEMORY_RW,
 408                                                    __builtin_return_address(0));
 409 }
 410
 411 void __iounmap(volatile void __iomem *io_addr)
 412 {
 413         void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
 414         struct static_vm *svm;
 415
 416         /* If this is a static mapping, we must leave it alone */
 417         svm = find_static_vm_vaddr(addr);
 418         if (svm)
 419                 return;
 420
 421 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
 422         {
 423                 struct vm_struct *vm;
 424
 425                 vm = find_vm_area(addr);
 426
 427                 /*
 428                  * If this is a section based mapping we need to handle it
 429                  * specially as the VM subsystem does not know how to handle
 430                  * such a beast.
 431                  */
 432                 if (vm && (vm->flags & VM_ARM_SECTION_MAPPING))
 433                         unmap_area_sections((unsigned long)vm->addr, vm->size);
 434         }
 435 #endif
 436
 437         vunmap(addr);
 438 }
 439
 440 void (*arch_iounmap)(volatile void __iomem *) = __iounmap;
 441
 442 void iounmap(volatile void __iomem *cookie)
 443 {
 444         arch_iounmap(cookie);
 445 }
 446 EXPORT_SYMBOL(iounmap);
 447
 448 #ifdef CONFIG_PCI
 449 static int pci_ioremap_mem_type = MT_DEVICE;
 450
 451 void pci_ioremap_set_mem_type(int mem_type)
 452 {
 453         pci_ioremap_mem_type = mem_type;
 454 }
 455
 456 int pci_ioremap_io(unsigned int offset, phys_addr_t phys_addr)
 457 {
 458         BUG_ON(offset + SZ_64K - 1 > IO_SPACE_LIMIT);
 459
 460         return ioremap_page_range(PCI_IO_VIRT_BASE + offset,
 461                                   PCI_IO_VIRT_BASE + offset + SZ_64K,
 462                                   phys_addr,
 463                                   __pgprot(get_mem_type(pci_ioremap_mem_type)->prot_pte));
 464 }
 465 EXPORT_SYMBOL_GPL(pci_ioremap_io);
 466
 467 void __iomem *pci_remap_cfgspace(resource_size_t res_cookie, size_t size)
 468 {
 469         return arch_ioremap_caller(res_cookie, size, MT_UNCACHED,
 470                                    __builtin_return_address(0));
 471 }
 472 EXPORT_SYMBOL_GPL(pci_remap_cfgspace);
 473 #endif
 474
 475 /*
 476  * Must be called after early_fixmap_init
 477  */
 478 void __init early_ioremap_init(void)
 479 {
 480         early_ioremap_setup();
 481 }