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 <linux/sched.h>
   8 #include <asm/pgtable.h>
   9 #include <asm/tlbflush.h>
  10 #include "as-layout.h"
  11 #include "mem_user.h"
  12 #include "os.h"
  13 #include "skas.h"
  14 #include "tlb.h"
  15
  16 struct host_vm_change {
  17         struct host_vm_op {
  18                 enum { NONE, MMAP, MUNMAP, MPROTECT } type;
  19                 union {
  20                         struct {
  21                                 unsigned long addr;
  22                                 unsigned long len;
  23                                 unsigned int prot;
  24                                 int fd;
  25                                 __u64 offset;
  26                         } mmap;
  27                         struct {
  28                                 unsigned long addr;
  29                                 unsigned long len;
  30                         } munmap;
  31                         struct {
  32                                 unsigned long addr;
  33                                 unsigned long len;
  34                                 unsigned int prot;
  35                         } mprotect;
  36                 } u;
  37         } ops[1];
  38         int index;
  39         struct mm_id *id;
  40         void *data;
  41         int force;
  42 };
  43
  44 #define INIT_HVC(mm, force) \
  45         ((struct host_vm_change) \
  46          { .ops         = { { .type = NONE } }, \
  47            .id          = &mm->context.id, \
  48            .data        = NULL, \
  49            .index       = 0, \
  50            .force       = force })
  51
  52 static int do_ops(struct host_vm_change *hvc, int end,
  53                   int finished)
  54 {
  55         struct host_vm_op *op;
  56         int i, ret = 0;
  57
  58         for (i = 0; i < end && !ret; i++) {
  59                 op = &hvc->ops[i];
  60                 switch(op->type) {
  61                 case MMAP:
  62                         ret = map(hvc->id, op->u.mmap.addr, op->u.mmap.len,
  63                                   op->u.mmap.prot, op->u.mmap.fd,
  64                                   op->u.mmap.offset, finished, &hvc->data);
  65                         break;
  66                 case MUNMAP:
  67                         ret = unmap(hvc->id, op->u.munmap.addr,
  68                                     op->u.munmap.len, finished, &hvc->data);
  69                         break;
  70                 case MPROTECT:
  71                         ret = protect(hvc->id, op->u.mprotect.addr,
  72                                       op->u.mprotect.len, op->u.mprotect.prot,
  73                                       finished, &hvc->data);
  74                         break;
  75                 default:
  76                         printk(KERN_ERR "Unknown op type %d in do_ops\n",
  77                                op->type);
  78                         break;
  79                 }
  80         }
  81
  82         return ret;
  83 }
  84
  85 static int add_mmap(unsigned long virt, unsigned long phys, unsigned long len,
  86                     unsigned int prot, struct host_vm_change *hvc)
  87 {
  88         __u64 offset;
  89         struct host_vm_op *last;
  90         int fd, ret = 0;
  91
  92         fd = phys_mapping(phys, &offset);
  93         if (hvc->index != 0) {
  94                 last = &hvc->ops[hvc->index - 1];
  95                 if ((last->type == MMAP) &&
  96                    (last->u.mmap.addr + last->u.mmap.len == virt) &&
  97                    (last->u.mmap.prot == prot) && (last->u.mmap.fd == fd) &&
  98                    (last->u.mmap.offset + last->u.mmap.len == offset)) {
  99                         last->u.mmap.len += len;
 100                         return 0;
 101                 }
 102         }
 103
 104         if (hvc->index == ARRAY_SIZE(hvc->ops)) {
 105                 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
 106                 hvc->index = 0;
 107         }
 108
 109         hvc->ops[hvc->index++] = ((struct host_vm_op)
 110                                   { .type       = MMAP,
 111                                     .u = { .mmap = { .addr      = virt,
 112                                                      .len       = len,
 113                                                      .prot      = prot,
 114                                                      .fd        = fd,
 115                                                      .offset    = offset }
 116                            } });
 117         return ret;
 118 }
 119
 120 static int add_munmap(unsigned long addr, unsigned long len,
 121                       struct host_vm_change *hvc)
 122 {
 123         struct host_vm_op *last;
 124         int ret = 0;
 125
 126         if (hvc->index != 0) {
 127                 last = &hvc->ops[hvc->index - 1];
 128                 if ((last->type == MUNMAP) &&
 129                    (last->u.munmap.addr + last->u.mmap.len == addr)) {
 130                         last->u.munmap.len += len;
 131                         return 0;
 132                 }
 133         }
 134
 135         if (hvc->index == ARRAY_SIZE(hvc->ops)) {
 136                 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
 137                 hvc->index = 0;
 138         }
 139
 140         hvc->ops[hvc->index++] = ((struct host_vm_op)
 141                                   { .type       = MUNMAP,
 142                                     .u = { .munmap = { .addr    = addr,
 143                                                        .len     = len } } });
 144         return ret;
 145 }
 146
 147 static int add_mprotect(unsigned long addr, unsigned long len,
 148                         unsigned int prot, struct host_vm_change *hvc)
 149 {
 150         struct host_vm_op *last;
 151         int ret = 0;
 152
 153         if (hvc->index != 0) {
 154                 last = &hvc->ops[hvc->index - 1];
 155                 if ((last->type == MPROTECT) &&
 156                    (last->u.mprotect.addr + last->u.mprotect.len == addr) &&
 157                    (last->u.mprotect.prot == prot)) {
 158                         last->u.mprotect.len += len;
 159                         return 0;
 160                 }
 161         }
 162
 163         if (hvc->index == ARRAY_SIZE(hvc->ops)) {
 164                 ret = do_ops(hvc, ARRAY_SIZE(hvc->ops), 0);
 165                 hvc->index = 0;
 166         }
 167
 168         hvc->ops[hvc->index++] = ((struct host_vm_op)
 169                                   { .type       = MPROTECT,
 170                                     .u = { .mprotect = { .addr  = addr,
 171                                                          .len   = len,
 172                                                          .prot  = prot } } });
 173         return ret;
 174 }
 175
 176 #define ADD_ROUND(n, inc) (((n) + (inc)) & ~((inc) - 1))
 177
 178 static inline int update_pte_range(pmd_t *pmd, unsigned long addr,
 179                                    unsigned long end,
 180                                    struct host_vm_change *hvc)
 181 {
 182         pte_t *pte;
 183         int r, w, x, prot, ret = 0;
 184
 185         pte = pte_offset_kernel(pmd, addr);
 186         do {
 187                 r = pte_read(*pte);
 188                 w = pte_write(*pte);
 189                 x = pte_exec(*pte);
 190                 if (!pte_young(*pte)) {
 191                         r = 0;
 192                         w = 0;
 193                 } else if (!pte_dirty(*pte)) {
 194                         w = 0;
 195                 }
 196                 prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
 197                         (x ? UM_PROT_EXEC : 0));
 198                 if (hvc->force || pte_newpage(*pte)) {
 199                         if (pte_present(*pte))
 200                                 ret = add_mmap(addr, pte_val(*pte) & PAGE_MASK,
 201                                                PAGE_SIZE, prot, hvc);
 202                         else ret = add_munmap(addr, PAGE_SIZE, hvc);
 203                 }
 204                 else if (pte_newprot(*pte))
 205                         ret = add_mprotect(addr, PAGE_SIZE, prot, hvc);
 206                 *pte = pte_mkuptodate(*pte);
 207         } while (pte++, addr += PAGE_SIZE, ((addr != end) && !ret));
 208         return ret;
 209 }
 210
 211 static inline int update_pmd_range(pud_t *pud, unsigned long addr,
 212                                    unsigned long end,
 213                                    struct host_vm_change *hvc)
 214 {
 215         pmd_t *pmd;
 216         unsigned long next;
 217         int ret = 0;
 218
 219         pmd = pmd_offset(pud, addr);
 220         do {
 221                 next = pmd_addr_end(addr, end);
 222                 if (!pmd_present(*pmd)) {
 223                         if (hvc->force || pmd_newpage(*pmd)) {
 224                                 ret = add_munmap(addr, next - addr, hvc);
 225                                 pmd_mkuptodate(*pmd);
 226                         }
 227                 }
 228                 else ret = update_pte_range(pmd, addr, next, hvc);
 229         } while (pmd++, addr = next, ((addr != end) && !ret));
 230         return ret;
 231 }
 232
 233 static inline int update_pud_range(pgd_t *pgd, unsigned long addr,
 234                                    unsigned long end,
 235                                    struct host_vm_change *hvc)
 236 {
 237         pud_t *pud;
 238         unsigned long next;
 239         int ret = 0;
 240
 241         pud = pud_offset(pgd, addr);
 242         do {
 243                 next = pud_addr_end(addr, end);
 244                 if (!pud_present(*pud)) {
 245                         if (hvc->force || pud_newpage(*pud)) {
 246                                 ret = add_munmap(addr, next - addr, hvc);
 247                                 pud_mkuptodate(*pud);
 248                         }
 249                 }
 250                 else ret = update_pmd_range(pud, addr, next, hvc);
 251         } while (pud++, addr = next, ((addr != end) && !ret));
 252         return ret;
 253 }
 254
 255 void fix_range_common(struct mm_struct *mm, unsigned long start_addr,
 256                       unsigned long end_addr, int force)
 257 {
 258         pgd_t *pgd;
 259         struct host_vm_change hvc;
 260         unsigned long addr = start_addr, next;
 261         int ret = 0;
 262
 263         hvc = INIT_HVC(mm, force);
 264         pgd = pgd_offset(mm, addr);
 265         do {
 266                 next = pgd_addr_end(addr, end_addr);
 267                 if (!pgd_present(*pgd)) {
 268                         if (force || pgd_newpage(*pgd)) {
 269                                 ret = add_munmap(addr, next - addr, &hvc);
 270                                 pgd_mkuptodate(*pgd);
 271                         }
 272                 }
 273                 else ret = update_pud_range(pgd, addr, next, &hvc);
 274         } while (pgd++, addr = next, ((addr != end_addr) && !ret));
 275
 276         if (!ret)
 277                 ret = do_ops(&hvc, hvc.index, 1);
 278
 279         /* This is not an else because ret is modified above */
 280         if (ret) {
 281                 printk(KERN_ERR "fix_range_common: failed, killing current "
 282                        "process\n");
 283                 force_sig(SIGKILL, current);
 284         }
 285 }
 286
 287 int flush_tlb_kernel_range_common(unsigned long start, unsigned long end)
 288 {
 289         struct mm_struct *mm;
 290         pgd_t *pgd;
 291         pud_t *pud;
 292         pmd_t *pmd;
 293         pte_t *pte;
 294         unsigned long addr, last;
 295         int updated = 0, err;
 296
 297         mm = &init_mm;
 298         for (addr = start; addr < end;) {
 299                 pgd = pgd_offset(mm, addr);
 300                 if (!pgd_present(*pgd)) {
 301                         last = ADD_ROUND(addr, PGDIR_SIZE);
 302                         if (last > end)
 303                                 last = end;
 304                         if (pgd_newpage(*pgd)) {
 305                                 updated = 1;
 306                                 err = os_unmap_memory((void *) addr,
 307                                                       last - addr);
 308                                 if (err < 0)
 309                                         panic("munmap failed, errno = %d\n",
 310                                               -err);
 311                         }
 312                         addr = last;
 313                         continue;
 314                 }
 315
 316                 pud = pud_offset(pgd, addr);
 317                 if (!pud_present(*pud)) {
 318                         last = ADD_ROUND(addr, PUD_SIZE);
 319                         if (last > end)
 320                                 last = end;
 321                         if (pud_newpage(*pud)) {
 322                                 updated = 1;
 323                                 err = os_unmap_memory((void *) addr,
 324                                                       last - addr);
 325                                 if (err < 0)
 326                                         panic("munmap failed, errno = %d\n",
 327                                               -err);
 328                         }
 329                         addr = last;
 330                         continue;
 331                 }
 332
 333                 pmd = pmd_offset(pud, addr);
 334                 if (!pmd_present(*pmd)) {
 335                         last = ADD_ROUND(addr, PMD_SIZE);
 336                         if (last > end)
 337                                 last = end;
 338                         if (pmd_newpage(*pmd)) {
 339                                 updated = 1;
 340                                 err = os_unmap_memory((void *) addr,
 341                                                       last - addr);
 342                                 if (err < 0)
 343                                         panic("munmap failed, errno = %d\n",
 344                                               -err);
 345                         }
 346                         addr = last;
 347                         continue;
 348                 }
 349
 350                 pte = pte_offset_kernel(pmd, addr);
 351                 if (!pte_present(*pte) || pte_newpage(*pte)) {
 352                         updated = 1;
 353                         err = os_unmap_memory((void *) addr,
 354                                               PAGE_SIZE);
 355                         if (err < 0)
 356                                 panic("munmap failed, errno = %d\n",
 357                                       -err);
 358                         if (pte_present(*pte))
 359                                 map_memory(addr,
 360                                            pte_val(*pte) & PAGE_MASK,
 361                                            PAGE_SIZE, 1, 1, 1);
 362                 }
 363                 else if (pte_newprot(*pte)) {
 364                         updated = 1;
 365                         os_protect_memory((void *) addr, PAGE_SIZE, 1, 1, 1);
 366                 }
 367                 addr += PAGE_SIZE;
 368         }
 369         return updated;
 370 }
 371
 372 void flush_tlb_page(struct vm_area_struct *vma, unsigned long address)
 373 {
 374         pgd_t *pgd;
 375         pud_t *pud;
 376         pmd_t *pmd;
 377         pte_t *pte;
 378         struct mm_struct *mm = vma->vm_mm;
 379         void *flush = NULL;
 380         int r, w, x, prot, err = 0;
 381         struct mm_id *mm_id;
 382
 383         address &= PAGE_MASK;
 384         pgd = pgd_offset(mm, address);
 385         if (!pgd_present(*pgd))
 386                 goto kill;
 387
 388         pud = pud_offset(pgd, address);
 389         if (!pud_present(*pud))
 390                 goto kill;
 391
 392         pmd = pmd_offset(pud, address);
 393         if (!pmd_present(*pmd))
 394                 goto kill;
 395
 396         pte = pte_offset_kernel(pmd, address);
 397
 398         r = pte_read(*pte);
 399         w = pte_write(*pte);
 400         x = pte_exec(*pte);
 401         if (!pte_young(*pte)) {
 402                 r = 0;
 403                 w = 0;
 404         } else if (!pte_dirty(*pte)) {
 405                 w = 0;
 406         }
 407
 408         mm_id = &mm->context.id;
 409         prot = ((r ? UM_PROT_READ : 0) | (w ? UM_PROT_WRITE : 0) |
 410                 (x ? UM_PROT_EXEC : 0));
 411         if (pte_newpage(*pte)) {
 412                 if (pte_present(*pte)) {
 413                         unsigned long long offset;
 414                         int fd;
 415
 416                         fd = phys_mapping(pte_val(*pte) & PAGE_MASK, &offset);
 417                         err = map(mm_id, address, PAGE_SIZE, prot, fd, offset,
 418                                   1, &flush);
 419                 }
 420                 else err = unmap(mm_id, address, PAGE_SIZE, 1, &flush);
 421         }
 422         else if (pte_newprot(*pte))
 423                 err = protect(mm_id, address, PAGE_SIZE, prot, 1, &flush);
 424
 425         if (err)
 426                 goto kill;
 427
 428         *pte = pte_mkuptodate(*pte);
 429
 430         return;
 431
 432 kill:
 433         printk(KERN_ERR "Failed to flush page for address 0x%lx\n", address);
 434         force_sig(SIGKILL, current);
 435 }
 436
 437 pgd_t *pgd_offset_proc(struct mm_struct *mm, unsigned long address)
 438 {
 439         return pgd_offset(mm, address);
 440 }
 441
 442 pud_t *pud_offset_proc(pgd_t *pgd, unsigned long address)
 443 {
 444         return pud_offset(pgd, address);
 445 }
 446
 447 pmd_t *pmd_offset_proc(pud_t *pud, unsigned long address)
 448 {
 449         return pmd_offset(pud, address);
 450 }
 451
 452 pte_t *pte_offset_proc(pmd_t *pmd, unsigned long address)
 453 {
 454         return pte_offset_kernel(pmd, address);
 455 }
 456
 457 pte_t *addr_pte(struct task_struct *task, unsigned long addr)
 458 {
 459         pgd_t *pgd = pgd_offset(task->mm, addr);
 460         pud_t *pud = pud_offset(pgd, addr);
 461         pmd_t *pmd = pmd_offset(pud, addr);
 462
 463         return pte_offset_map(pmd, addr);
 464 }
 465
 466 void flush_tlb_all(void)
 467 {
 468         flush_tlb_mm(current->mm);
 469 }
 470
 471 void flush_tlb_kernel_range(unsigned long start, unsigned long end)
 472 {
 473         flush_tlb_kernel_range_common(start, end);
 474 }
 475
 476 void flush_tlb_kernel_vm(void)
 477 {
 478         flush_tlb_kernel_range_common(start_vm, end_vm);
 479 }
 480
 481 void __flush_tlb_one(unsigned long addr)
 482 {
 483         flush_tlb_kernel_range_common(addr, addr + PAGE_SIZE);
 484 }
 485
 486 static void fix_range(struct mm_struct *mm, unsigned long start_addr,
 487                       unsigned long end_addr, int force)
 488 {
 489         if (!proc_mm && (end_addr > STUB_START))
 490                 end_addr = STUB_START;
 491
 492         fix_range_common(mm, start_addr, end_addr, force);
 493 }
 494
 495 void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
 496                      unsigned long end)
 497 {
 498         if (vma->vm_mm == NULL)
 499                 flush_tlb_kernel_range_common(start, end);
 500         else fix_range(vma->vm_mm, start, end, 0);
 501 }
 502
 503 void flush_tlb_mm(struct mm_struct *mm)
 504 {
 505         unsigned long end;
 506
 507         /*
 508          * Don't bother flushing if this address space is about to be
 509          * destroyed.
 510          */
 511         if (atomic_read(&mm->mm_users) == 0)
 512                 return;
 513
 514         end = proc_mm ? task_size : STUB_START;
 515         fix_range(mm, 0, end, 0);
 516 }
 517
 518 void force_flush_all(void)
 519 {
 520         struct mm_struct *mm = current->mm;
 521         struct vm_area_struct *vma = mm->mmap;
 522
 523         while (vma != NULL) {
 524                 fix_range(mm, vma->vm_start, vma->vm_end, 1);
 525                 vma = vma->vm_next;
 526         }
 527 }