arch/um/kernel/tlb.c

   1 /*
   2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include "linux/mm.h"
   7 #include "asm/pgtable.h"
   8 #include "asm/tlbflush.h"
   9 #include "as-layout.h"
  10 #include "mem_user.h"
  11 #include "os.h"
  12 #include "skas.h"
  13 #include "tlb.h"
  14
  15 struct host_vm_change {
  16         struct host_vm_op {
  17                 enum { NONE, MMAP, MUNMAP, MPROTECT } type;
  18                 union {
  19                         struct {
  20                                 unsigned long addr;
  21                                 unsigned long len;
  22                                 unsigned int prot;
  23                                 int fd;
  24                                 __u64 offset;
  25                         } mmap;
  26                         struct {
  27                                 unsigned long addr;
  28                                 unsigned long len;
  29                         } munmap;
  30                         struct {
  31                                 unsigned long addr;
  32                                 unsigned long len;
  33                                 unsigned int prot;
  34                         } mprotect;
  35                 } u;
  36         } ops[1];
  37         int index;
  38         struct mm_id *id;
  39         void *data;
  40         int force;
  41 };
  42
  43 #define INIT_HVC(mm, force) \
  44         ((struct host_vm_change) \
  45          { .ops         = { { .type = NONE } }, \
  46            .id          = &mm->context.id, \
  47            .data        = NULL, \
  48            .index       = 0, \
  49            .force       = force })
  50
  51 static int do_ops(struct host_vm_change *hvc, int end,
  52                   int finished)
  53 {
  54         struct host_vm_op *op;
  55         int i, ret = 0;
  56
  57         for (i = 0; i < end && !ret; i++) {
  58                 op = &hvc->ops[i];
  59                 switch(op->type) {
  60                 case MMAP:
  61                         ret = map(hvc->id, op->u.mmap.addr, op->u.mmap.len,
  62                                   op->u.mmap.prot, op->u.mmap.fd,
  63                                   op->u.mmap.offset, finished, &hvc->data);
  64                         break;
  65                 case MUNMAP:
  66                         ret = unmap(hvc->id, op->u.munmap.addr,
  67                                     op->u.munmap.len, finished, &hvc->data);
  68                         break;
  69                 case MPROTECT:
  70                         ret = protect(hvc->id, op->u.mprotect.addr,
  71                                       op->u.mprotect.len, op->u.mprotect.prot,
  72                                       finished, &hvc->data);
  73                         break;
  74                 default:
  75                         printk(KERN_ERR "Unknown op type %d in do_ops\n",
  76                                op->type);
  77                         break;
  78                 }
  79         }
  80
  81         return ret;
  82 }
  83
  84 static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
  85                     unsigned int prot, struct host_vm_change *hvc)
  86 {
  87         __u64 offset;
  88         struct host_vm_op *last;
  89         int fd, ret = 0;
  90
  91         fd = phys_mapping(phys, &offset);
  92         if (hvc->index != 0) {
  93                 last = &hvc->ops[hvc->index - 1];
  94                 if ((last->type == MMAP) &&
  95                    (last->u.mmap.addr + last->u.mmap.len == virt) &&
  96                    (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) &&
  97                    (last->u.mmap.offset + last->u.mmap.len == offset)) {
  98                         last->u.mmap.len += len;
  99                         return 0;
 100                 }
 101         }
 102
 103         if (hvc->index == ARRAY_SIZE(hvc->ops)) {
 104                 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
 105                 hvc->index = 0;
 106         }
 107
 108         hvc->ops[hvc->index++] = ((struct host_vm_op)
 109                                   { .type       = MMAP,
 110                                     .u = { .mmap = { .addr      = virt,
 111                                                      .len       = len,
 112                                                      .prot      = prot,
 113                                                      .fd        = fd,
 114                                                      .offset    = offset }
 115                            } });
 116         return ret;
 117 }
 118
 119 static int add_munmap(unsigned long addr, unsigned long len,
 120                       struct host_vm_change *hvc)
 121 {
 122         struct host_vm_op *last;
 123         int ret = 0;
 124
 125         if (hvc->index != 0) {
 126                 last = &hvc->ops[hvc->index - 1];
 127                 if ((last->type == MUNMAP) &&
 128                    (last->u.munmap.addr + last->u.mmap.len == addr)) {
 129                         last->u.munmap.len += len;
 130                         return 0;
 131                 }
 132         }
 133
 134         if (hvc->index == ARRAY_SIZE(hvc->ops)) {
 135                 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
 136                 hvc->index = 0;
 137         }
 138
 139         hvc->ops[hvc->index++] = ((struct host_vm_op)
 140                                   { .type       = MUNMAP,
 141                                     .u = { .munmap = { .addr    = addr,
 142                                                        .len     = len } } });
 143         return ret;
 144 }
 145
 146 static int add_mprotect(unsigned long addr, unsigned long len,
 147                         unsigned int prot, struct host_vm_change *hvc)
 148 {
 149         struct host_vm_op *last;
 150         int ret = 0;
 151
 152         if (hvc->index != 0) {
 153                 last = &hvc->ops[hvc->index - 1];
 154                 if ((last->type == MPROTECT) &&
 155                    (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
 156                    (last->u.mprotect.prot == prot)) {
 157                         last->u.mprotect.len += len;
 158                         return 0;
 159                 }
 160         }
 161
 162         if (hvc->index == ARRAY_SIZE(hvc->ops)) {
 163                 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
 164                 hvc->index = 0;
 165         }
 166
 167         hvc->ops[hvc->index++] = ((struct host_vm_op)
 168                                   { .type       = MPROTECT,
 169                                     .u = { .mprotect = { .addr  = addr,
 170                                                          .len   = len,
 171                                                          .prot  = prot } } });
 172         return ret;
 173 }
 174
 175 #define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
 176
 177 static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
 178                                    unsigned long end,
 179                                    struct host_vm_change *hvc)
 180 {
 181         pte_t *pte;
 182         int r, w, x, prot, ret = 0;
 183
 184         pte = pte_offset_kernel(pmd, addr);
 185         do {
 186                 r = pte_read(*pte);
 187                 w = pte_write(*pte);
 188                 x = pte_exec(*pte);
 189                 if (!pte_young(*pte)) {
 190                         r = 0;
 191                         w = 0;
 192                 } else if (!pte_dirty(*pte)) {
 193                         w = 0;
 194                 }
 195                 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
 196                         (x ? UM_PROT_EXEC : 0));
 197                 if (hvc->force || pte_newpage(*pte)) {
 198                         if (pte_present(*pte))
 199                                 ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
 200                                                PAGE_SIZE, prot, hvc);
 201                         else ret = add_munmap(addr, PAGE_SIZE, hvc);
 202                 }
 203                 else if (pte_newprot(*pte))
 204                         ret = add_mprotect(addr, PAGE_SIZE, prot, hvc);
 205                 *pte = pte_mkuptodate(*pte);
 206         } while (pte++, addr += PAGE_SIZE, ((addr != end) && !ret));
 207         return ret;
 208 }
 209
 210 static inline int update_pmd_range(pud_t *pud, unsigned long addr,
 211                                    unsigned long end,
 212                                    struct host_vm_change *hvc)
 213 {
 214         pmd_t *pmd;
 215         unsigned long next;
 216         int ret = 0;
 217
 218         pmd = pmd_offset(pud, addr);
 219         do {
 220                 next = pmd_addr_end(addr, end);
 221                 if (!pmd_present(*pmd)) {
 222                         if (hvc->force || pmd_newpage(*pmd)) {
 223                                 ret = add_munmap(addr, next - addr, hvc);
 224                                 pmd_mkuptodate(*pmd);
 225                         }
 226                 }
 227                 else ret = update_pte_range(pmd, addr, next, hvc);
 228         } while (pmd++, addr = next, ((addr != end) && !ret));
 229         return ret;
 230 }
 231
 232 static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
 233                                    unsigned long end,
 234                                    struct host_vm_change *hvc)
 235 {
 236         pud_t *pud;
 237         unsigned long next;
 238         int ret = 0;
 239
 240         pud = pud_offset(pgd, addr);
 241         do {
 242                 next = pud_addr_end(addr, end);
 243                 if (!pud_present(*pud)) {
 244                         if (hvc->force || pud_newpage(*pud)) {
 245                                 ret = add_munmap(addr, next - addr, hvc);
 246                                 pud_mkuptodate(*pud);
 247                         }
 248                 }
 249                 else ret = update_pmd_range(pud, addr, next, hvc);
 250         } while (pud++, addr = next, ((addr != end) && !ret));
 251         return ret;
 252 }
 253
 254 void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
 255                       unsigned long end_addr, int force)
 256 {
 257         pgd_t *pgd;
 258         struct host_vm_change hvc;
 259         unsigned long addr = start_addr, next;
 260         int ret = 0;
 261
 262         hvc = INIT_HVC(mm, force);
 263         pgd = pgd_offset(mm, addr);
 264         do {
 265                 next = pgd_addr_end(addr, end_addr);
 266                 if (!pgd_present(*pgd)) {
 267                         if (force || pgd_newpage(*pgd)) {
 268                                 ret = add_munmap(addr, next - addr, &hvc);
 269                                 pgd_mkuptodate(*pgd);
 270                         }
 271                 }
 272                 else ret = update_pud_range(pgd, addr, next, &hvc);
 273         } while (pgd++, addr = next, ((addr != end_addr) && !ret));
 274
 275         if (!ret)
 276                 ret = do_ops(&hvc, hvc.index, 1);
 277
 278         /* This is not an else because ret is modified above */
 279         if (ret) {
 280                 printk(KERN_ERR "fix_range_common: failed, killing current "
 281                        "process\n");
 282                 force_sig(SIGKILL, current);
 283         }
 284 }
 285
 286 int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
 287 {
 288         struct mm_struct *mm;
 289         pgd_t *pgd;
 290         pud_t *pud;
 291         pmd_t *pmd;
 292         pte_t *pte;
 293         unsigned long addr, last;
 294         int updated = 0, err;
 295
 296         mm = &init_mm;
 297         for (addr = start; addr < end;) {
 298                 pgd = pgd_offset(mm, addr);
 299                 if (!pgd_present(*pgd)) {
 300                         last = ADD_ROUND(addr, PGDIR_SIZE);
 301                         if (last > end)
 302                                 last = end;
 303                         if (pgd_newpage(*pgd)) {
 304                                 updated = 1;
 305                                 err = os_unmap_memory((void *) addr,
 306                                                       last - addr);
 307                                 if (err < 0)
 308                                         panic("munmap failed, errno = %d\n",
 309                                               -err);
 310                         }
 311                         addr = last;
 312                         continue;
 313                 }
 314
 315                 pud = pud_offset(pgd, addr);
 316                 if (!pud_present(*pud)) {
 317                         last = ADD_ROUND(addr, PUD_SIZE);
 318                         if (last > end)
 319                                 last = end;
 320                         if (pud_newpage(*pud)) {
 321                                 updated = 1;
 322                                 err = os_unmap_memory((void *) addr,
 323                                                       last - addr);
 324                                 if (err < 0)
 325                                         panic("munmap failed, errno = %d\n",
 326                                               -err);
 327                         }
 328                         addr = last;
 329                         continue;
 330                 }
 331
 332                 pmd = pmd_offset(pud, addr);
 333                 if (!pmd_present(*pmd)) {
 334                         last = ADD_ROUND(addr, PMD_SIZE);
 335                         if (last > end)
 336                                 last = end;
 337                         if (pmd_newpage(*pmd)) {
 338                                 updated = 1;
 339                                 err = os_unmap_memory((void *) addr,
 340                                                       last - addr);
 341                                 if (err < 0)
 342                                         panic("munmap failed, errno = %d\n",
 343                                               -err);
 344                         }
 345                         addr = last;
 346                         continue;
 347                 }
 348
 349                 pte = pte_offset_kernel(pmd, addr);
 350                 if (!pte_present(*pte) || pte_newpage(*pte)) {
 351                         updated = 1;
 352                         err = os_unmap_memory((void *) addr,
 353                                               PAGE_SIZE);
 354                         if (err < 0)
 355                                 panic("munmap failed, errno = %d\n",
 356                                       -err);
 357                         if (pte_present(*pte))
 358                                 map_memory(addr,
 359                                            pte_val(*pte) & PAGE_MASK,
 360                                            PAGE_SIZE, 1, 1, 1);
 361                 }
 362                 else if (pte_newprot(*pte)) {
 363                         updated = 1;
 364                         os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
 365                 }
 366                 addr += PAGE_SIZE;
 367         }
 368         return updated;
 369 }
 370
 371 void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
 372 {
 373         pgd_t *pgd;
 374         pud_t *pud;
 375         pmd_t *pmd;
 376         pte_t *pte;
 377         struct mm_struct *mm = vma->vm_mm;
 378         void *flush = NULL;
 379         int r, w, x, prot, err = 0;
 380         struct mm_id *mm_id;
 381
 382         address &= PAGE_MASK;
 383         pgd = pgd_offset(mm, address);
 384         if (!pgd_present(*pgd))
 385                 goto kill;
 386
 387         pud = pud_offset(pgd, address);
 388         if (!pud_present(*pud))
 389                 goto kill;
 390
 391         pmd = pmd_offset(pud, address);
 392         if (!pmd_present(*pmd))
 393                 goto kill;
 394
 395         pte = pte_offset_kernel(pmd, address);
 396
 397         r = pte_read(*pte);
 398         w = pte_write(*pte);
 399         x = pte_exec(*pte);
 400         if (!pte_young(*pte)) {
 401                 r = 0;
 402                 w = 0;
 403         } else if (!pte_dirty(*pte)) {
 404                 w = 0;
 405         }
 406
 407         mm_id = &mm->context.id;
 408         prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
 409                 (x ? UM_PROT_EXEC : 0));
 410         if (pte_newpage(*pte)) {
 411                 if (pte_present(*pte)) {
 412                         unsigned long long offset;
 413                         int fd;
 414
 415                         fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
 416                         err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
 417                                   1, &flush);
 418                 }
 419                 else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
 420         }
 421         else if (pte_newprot(*pte))
 422                 err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
 423
 424         if (err)
 425                 goto kill;
 426
 427         *pte = pte_mkuptodate(*pte);
 428
 429         return;
 430
 431 kill:
 432         printk(KERN_ERR "Failed to flush page for address 0x%lx\n", address);
 433         force_sig(SIGKILL, current);
 434 }
 435
 436 pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
 437 {
 438         return pgd_offset(mm, address);
 439 }
 440
 441 pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
 442 {
 443         return pud_offset(pgd, address);
 444 }
 445
 446 pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
 447 {
 448         return pmd_offset(pud, address);
 449 }
 450
 451 pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
 452 {
 453         return pte_offset_kernel(pmd, address);
 454 }
 455
 456 pte_t *addr_pte(struct task_struct *task, unsigned long addr)
 457 {
 458         pgd_t *pgd = pgd_offset(task->mm, addr);
 459         pud_t *pud = pud_offset(pgd, addr);
 460         pmd_t *pmd = pmd_offset(pud, addr);
 461
 462         return pte_offset_map(pmd, addr);
 463 }
 464
 465 void flush_tlb_all(void)
 466 {
 467         flush_tlb_mm(current->mm);
 468 }
 469
 470 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 471 {
 472         flush_tlb_kernel_range_common(start, end);
 473 }
 474
 475 void flush_tlb_kernel_vm(void)
 476 {
 477         flush_tlb_kernel_range_common(start_vm, end_vm);
 478 }
 479
 480 void __flush_tlb_one(unsigned long addr)
 481 {
 482         flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE);
 483 }
 484
 485 static void fix_range(struct mm_struct *mm, unsigned long start_addr,
 486                       unsigned long end_addr, int force)
 487 {
 488         if (!proc_mm && (end_addr > STUB_START))
 489                 end_addr = STUB_START;
 490
 491         fix_range_common(mm, start_addr, end_addr, force);
 492 }
 493
 494 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 495                      unsigned long end)
 496 {
 497         if (vma->vm_mm == NULL)
 498                 flush_tlb_kernel_range_common(start, end);
 499         else fix_range(vma->vm_mm, start, end, 0);
 500 }
 501
 502 void flush_tlb_mm(struct mm_struct *mm)
 503 {
 504         unsigned long end;
 505
 506         /*
 507          * Don't bother flushing if this address space is about to be
 508          * destroyed.
 509          */
 510         if (atomic_read(&mm->mm_users) == 0)
 511                 return;
 512
 513         end = proc_mm ? task_size : STUB_START;
 514         fix_range(mm, 0, end, 0);
 515 }
 516
 517 void force_flush_all(void)
 518 {
 519         struct mm_struct *mm = current->mm;
 520         struct vm_area_struct *vma = mm->mmap;
 521
 522         while (vma != NULL) {
 523                 fix_range(mm, vma->vm_start, vma->vm_end, 1);
 524                 vma = vma->vm_next;
 525         }
 526 }