linux/arch/powerpc/mm/slice.c
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   1/*
   2 * address space "slices" (meta-segments) support
   3 *
   4 * Copyright (C) 2007 Benjamin Herrenschmidt, IBM Corporation.
   5 *
   6 * Based on hugetlb implementation
   7 *
   8 * Copyright (C) 2003 David Gibson, IBM Corporation.
   9 *
  10 * This program is free software; you can redistribute it and/or modify
  11 * it under the terms of the GNU General Public License as published by
  12 * the Free Software Foundation; either version 2 of the License, or
  13 * (at your option) any later version.
  14 *
  15 * This program is distributed in the hope that it will be useful,
  16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 * GNU General Public License for more details.
  19 *
  20 * You should have received a copy of the GNU General Public License
  21 * along with this program; if not, write to the Free Software
  22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  23 */
  24
  25#undef DEBUG
  26
  27#include <linux/kernel.h>
  28#include <linux/mm.h>
  29#include <linux/pagemap.h>
  30#include <linux/err.h>
  31#include <linux/spinlock.h>
  32#include <linux/export.h>
  33#include <linux/hugetlb.h>
  34#include <asm/mman.h>
  35#include <asm/mmu.h>
  36#include <asm/copro.h>
  37#include <asm/hugetlb.h>
  38
  39/* some sanity checks */
  40#if (PGTABLE_RANGE >> 43) > SLICE_MASK_SIZE
  41#error PGTABLE_RANGE exceeds slice_mask high_slices size
  42#endif
  43
  44static DEFINE_SPINLOCK(slice_convert_lock);
  45
  46
  47#ifdef DEBUG
  48int _slice_debug = 1;
  49
  50static void slice_print_mask(const char *label, struct slice_mask mask)
  51{
  52        char    *p, buf[16 + 3 + 64 + 1];
  53        int     i;
  54
  55        if (!_slice_debug)
  56                return;
  57        p = buf;
  58        for (i = 0; i < SLICE_NUM_LOW; i++)
  59                *(p++) = (mask.low_slices & (1 << i)) ? '1' : '0';
  60        *(p++) = ' ';
  61        *(p++) = '-';
  62        *(p++) = ' ';
  63        for (i = 0; i < SLICE_NUM_HIGH; i++)
  64                *(p++) = (mask.high_slices & (1ul << i)) ? '1' : '0';
  65        *(p++) = 0;
  66
  67        printk(KERN_DEBUG "%s:%s\n", label, buf);
  68}
  69
  70#define slice_dbg(fmt...) do { if (_slice_debug) pr_debug(fmt); } while(0)
  71
  72#else
  73
  74static void slice_print_mask(const char *label, struct slice_mask mask) {}
  75#define slice_dbg(fmt...)
  76
  77#endif
  78
  79static struct slice_mask slice_range_to_mask(unsigned long start,
  80                                             unsigned long len)
  81{
  82        unsigned long end = start + len - 1;
  83        struct slice_mask ret = { 0, 0 };
  84
  85        if (start < SLICE_LOW_TOP) {
  86                unsigned long mend = min(end, SLICE_LOW_TOP);
  87                unsigned long mstart = min(start, SLICE_LOW_TOP);
  88
  89                ret.low_slices = (1u << (GET_LOW_SLICE_INDEX(mend) + 1))
  90                        - (1u << GET_LOW_SLICE_INDEX(mstart));
  91        }
  92
  93        if ((start + len) > SLICE_LOW_TOP)
  94                ret.high_slices = (1ul << (GET_HIGH_SLICE_INDEX(end) + 1))
  95                        - (1ul << GET_HIGH_SLICE_INDEX(start));
  96
  97        return ret;
  98}
  99
 100static int slice_area_is_free(struct mm_struct *mm, unsigned long addr,
 101                              unsigned long len)
 102{
 103        struct vm_area_struct *vma;
 104
 105        if ((mm->task_size - len) < addr)
 106                return 0;
 107        vma = find_vma(mm, addr);
 108        return (!vma || (addr + len) <= vma->vm_start);
 109}
 110
 111static int slice_low_has_vma(struct mm_struct *mm, unsigned long slice)
 112{
 113        return !slice_area_is_free(mm, slice << SLICE_LOW_SHIFT,
 114                                   1ul << SLICE_LOW_SHIFT);
 115}
 116
 117static int slice_high_has_vma(struct mm_struct *mm, unsigned long slice)
 118{
 119        unsigned long start = slice << SLICE_HIGH_SHIFT;
 120        unsigned long end = start + (1ul << SLICE_HIGH_SHIFT);
 121
 122        /* Hack, so that each addresses is controlled by exactly one
 123         * of the high or low area bitmaps, the first high area starts
 124         * at 4GB, not 0 */
 125        if (start == 0)
 126                start = SLICE_LOW_TOP;
 127
 128        return !slice_area_is_free(mm, start, end - start);
 129}
 130
 131static struct slice_mask slice_mask_for_free(struct mm_struct *mm)
 132{
 133        struct slice_mask ret = { 0, 0 };
 134        unsigned long i;
 135
 136        for (i = 0; i < SLICE_NUM_LOW; i++)
 137                if (!slice_low_has_vma(mm, i))
 138                        ret.low_slices |= 1u << i;
 139
 140        if (mm->task_size <= SLICE_LOW_TOP)
 141                return ret;
 142
 143        for (i = 0; i < SLICE_NUM_HIGH; i++)
 144                if (!slice_high_has_vma(mm, i))
 145                        ret.high_slices |= 1ul << i;
 146
 147        return ret;
 148}
 149
 150static struct slice_mask slice_mask_for_size(struct mm_struct *mm, int psize)
 151{
 152        unsigned char *hpsizes;
 153        int index, mask_index;
 154        struct slice_mask ret = { 0, 0 };
 155        unsigned long i;
 156        u64 lpsizes;
 157
 158        lpsizes = mm->context.low_slices_psize;
 159        for (i = 0; i < SLICE_NUM_LOW; i++)
 160                if (((lpsizes >> (i * 4)) & 0xf) == psize)
 161                        ret.low_slices |= 1u << i;
 162
 163        hpsizes = mm->context.high_slices_psize;
 164        for (i = 0; i < SLICE_NUM_HIGH; i++) {
 165                mask_index = i & 0x1;
 166                index = i >> 1;
 167                if (((hpsizes[index] >> (mask_index * 4)) & 0xf) == psize)
 168                        ret.high_slices |= 1ul << i;
 169        }
 170
 171        return ret;
 172}
 173
 174static int slice_check_fit(struct slice_mask mask, struct slice_mask available)
 175{
 176        return (mask.low_slices & available.low_slices) == mask.low_slices &&
 177                (mask.high_slices & available.high_slices) == mask.high_slices;
 178}
 179
 180static void slice_flush_segments(void *parm)
 181{
 182        struct mm_struct *mm = parm;
 183        unsigned long flags;
 184
 185        if (mm != current->active_mm)
 186                return;
 187
 188        /* update the paca copy of the context struct */
 189        get_paca()->context = current->active_mm->context;
 190
 191        local_irq_save(flags);
 192        slb_flush_and_rebolt();
 193        local_irq_restore(flags);
 194}
 195
 196static void slice_convert(struct mm_struct *mm, struct slice_mask mask, int psize)
 197{
 198        int index, mask_index;
 199        /* Write the new slice psize bits */
 200        unsigned char *hpsizes;
 201        u64 lpsizes;
 202        unsigned long i, flags;
 203
 204        slice_dbg("slice_convert(mm=%p, psize=%d)\n", mm, psize);
 205        slice_print_mask(" mask", mask);
 206
 207        /* We need to use a spinlock here to protect against
 208         * concurrent 64k -> 4k demotion ...
 209         */
 210        spin_lock_irqsave(&slice_convert_lock, flags);
 211
 212        lpsizes = mm->context.low_slices_psize;
 213        for (i = 0; i < SLICE_NUM_LOW; i++)
 214                if (mask.low_slices & (1u << i))
 215                        lpsizes = (lpsizes & ~(0xful << (i * 4))) |
 216                                (((unsigned long)psize) << (i * 4));
 217
 218        /* Assign the value back */
 219        mm->context.low_slices_psize = lpsizes;
 220
 221        hpsizes = mm->context.high_slices_psize;
 222        for (i = 0; i < SLICE_NUM_HIGH; i++) {
 223                mask_index = i & 0x1;
 224                index = i >> 1;
 225                if (mask.high_slices & (1ul << i))
 226                        hpsizes[index] = (hpsizes[index] &
 227                                          ~(0xf << (mask_index * 4))) |
 228                                (((unsigned long)psize) << (mask_index * 4));
 229        }
 230
 231        slice_dbg(" lsps=%lx, hsps=%lx\n",
 232                  mm->context.low_slices_psize,
 233                  mm->context.high_slices_psize);
 234
 235        spin_unlock_irqrestore(&slice_convert_lock, flags);
 236
 237        copro_flush_all_slbs(mm);
 238}
 239
 240/*
 241 * Compute which slice addr is part of;
 242 * set *boundary_addr to the start or end boundary of that slice
 243 * (depending on 'end' parameter);
 244 * return boolean indicating if the slice is marked as available in the
 245 * 'available' slice_mark.
 246 */
 247static bool slice_scan_available(unsigned long addr,
 248                                 struct slice_mask available,
 249                                 int end,
 250                                 unsigned long *boundary_addr)
 251{
 252        unsigned long slice;
 253        if (addr < SLICE_LOW_TOP) {
 254                slice = GET_LOW_SLICE_INDEX(addr);
 255                *boundary_addr = (slice + end) << SLICE_LOW_SHIFT;
 256                return !!(available.low_slices & (1u << slice));
 257        } else {
 258                slice = GET_HIGH_SLICE_INDEX(addr);
 259                *boundary_addr = (slice + end) ?
 260                        ((slice + end) << SLICE_HIGH_SHIFT) : SLICE_LOW_TOP;
 261                return !!(available.high_slices & (1ul << slice));
 262        }
 263}
 264
 265static unsigned long slice_find_area_bottomup(struct mm_struct *mm,
 266                                              unsigned long len,
 267                                              struct slice_mask available,
 268                                              int psize)
 269{
 270        int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
 271        unsigned long addr, found, next_end;
 272        struct vm_unmapped_area_info info;
 273
 274        info.flags = 0;
 275        info.length = len;
 276        info.align_mask = PAGE_MASK & ((1ul << pshift) - 1);
 277        info.align_offset = 0;
 278
 279        addr = TASK_UNMAPPED_BASE;
 280        while (addr < TASK_SIZE) {
 281                info.low_limit = addr;
 282                if (!slice_scan_available(addr, available, 1, &addr))
 283                        continue;
 284
 285 next_slice:
 286                /*
 287                 * At this point [info.low_limit; addr) covers
 288                 * available slices only and ends at a slice boundary.
 289                 * Check if we need to reduce the range, or if we can
 290                 * extend it to cover the next available slice.
 291                 */
 292                if (addr >= TASK_SIZE)
 293                        addr = TASK_SIZE;
 294                else if (slice_scan_available(addr, available, 1, &next_end)) {
 295                        addr = next_end;
 296                        goto next_slice;
 297                }
 298                info.high_limit = addr;
 299
 300                found = vm_unmapped_area(&info);
 301                if (!(found & ~PAGE_MASK))
 302                        return found;
 303        }
 304
 305        return -ENOMEM;
 306}
 307
 308static unsigned long slice_find_area_topdown(struct mm_struct *mm,
 309                                             unsigned long len,
 310                                             struct slice_mask available,
 311                                             int psize)
 312{
 313        int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
 314        unsigned long addr, found, prev;
 315        struct vm_unmapped_area_info info;
 316
 317        info.flags = VM_UNMAPPED_AREA_TOPDOWN;
 318        info.length = len;
 319        info.align_mask = PAGE_MASK & ((1ul << pshift) - 1);
 320        info.align_offset = 0;
 321
 322        addr = mm->mmap_base;
 323        while (addr > PAGE_SIZE) {
 324                info.high_limit = addr;
 325                if (!slice_scan_available(addr - 1, available, 0, &addr))
 326                        continue;
 327
 328 prev_slice:
 329                /*
 330                 * At this point [addr; info.high_limit) covers
 331                 * available slices only and starts at a slice boundary.
 332                 * Check if we need to reduce the range, or if we can
 333                 * extend it to cover the previous available slice.
 334                 */
 335                if (addr < PAGE_SIZE)
 336                        addr = PAGE_SIZE;
 337                else if (slice_scan_available(addr - 1, available, 0, &prev)) {
 338                        addr = prev;
 339                        goto prev_slice;
 340                }
 341                info.low_limit = addr;
 342
 343                found = vm_unmapped_area(&info);
 344                if (!(found & ~PAGE_MASK))
 345                        return found;
 346        }
 347
 348        /*
 349         * A failed mmap() very likely causes application failure,
 350         * so fall back to the bottom-up function here. This scenario
 351         * can happen with large stack limits and large mmap()
 352         * allocations.
 353         */
 354        return slice_find_area_bottomup(mm, len, available, psize);
 355}
 356
 357
 358static unsigned long slice_find_area(struct mm_struct *mm, unsigned long len,
 359                                     struct slice_mask mask, int psize,
 360                                     int topdown)
 361{
 362        if (topdown)
 363                return slice_find_area_topdown(mm, len, mask, psize);
 364        else
 365                return slice_find_area_bottomup(mm, len, mask, psize);
 366}
 367
 368#define or_mask(dst, src)       do {                    \
 369        (dst).low_slices |= (src).low_slices;           \
 370        (dst).high_slices |= (src).high_slices;         \
 371} while (0)
 372
 373#define andnot_mask(dst, src)   do {                    \
 374        (dst).low_slices &= ~(src).low_slices;          \
 375        (dst).high_slices &= ~(src).high_slices;        \
 376} while (0)
 377
 378#ifdef CONFIG_PPC_64K_PAGES
 379#define MMU_PAGE_BASE   MMU_PAGE_64K
 380#else
 381#define MMU_PAGE_BASE   MMU_PAGE_4K
 382#endif
 383
 384unsigned long slice_get_unmapped_area(unsigned long addr, unsigned long len,
 385                                      unsigned long flags, unsigned int psize,
 386                                      int topdown)
 387{
 388        struct slice_mask mask = {0, 0};
 389        struct slice_mask good_mask;
 390        struct slice_mask potential_mask = {0,0} /* silence stupid warning */;
 391        struct slice_mask compat_mask = {0, 0};
 392        int fixed = (flags & MAP_FIXED);
 393        int pshift = max_t(int, mmu_psize_defs[psize].shift, PAGE_SHIFT);
 394        struct mm_struct *mm = current->mm;
 395        unsigned long newaddr;
 396
 397        /* Sanity checks */
 398        BUG_ON(mm->task_size == 0);
 399
 400        slice_dbg("slice_get_unmapped_area(mm=%p, psize=%d...\n", mm, psize);
 401        slice_dbg(" addr=%lx, len=%lx, flags=%lx, topdown=%d\n",
 402                  addr, len, flags, topdown);
 403
 404        if (len > mm->task_size)
 405                return -ENOMEM;
 406        if (len & ((1ul << pshift) - 1))
 407                return -EINVAL;
 408        if (fixed && (addr & ((1ul << pshift) - 1)))
 409                return -EINVAL;
 410        if (fixed && addr > (mm->task_size - len))
 411                return -ENOMEM;
 412
 413        /* If hint, make sure it matches our alignment restrictions */
 414        if (!fixed && addr) {
 415                addr = _ALIGN_UP(addr, 1ul << pshift);
 416                slice_dbg(" aligned addr=%lx\n", addr);
 417                /* Ignore hint if it's too large or overlaps a VMA */
 418                if (addr > mm->task_size - len ||
 419                    !slice_area_is_free(mm, addr, len))
 420                        addr = 0;
 421        }
 422
 423        /* First make up a "good" mask of slices that have the right size
 424         * already
 425         */
 426        good_mask = slice_mask_for_size(mm, psize);
 427        slice_print_mask(" good_mask", good_mask);
 428
 429        /*
 430         * Here "good" means slices that are already the right page size,
 431         * "compat" means slices that have a compatible page size (i.e.
 432         * 4k in a 64k pagesize kernel), and "free" means slices without
 433         * any VMAs.
 434         *
 435         * If MAP_FIXED:
 436         *      check if fits in good | compat => OK
 437         *      check if fits in good | compat | free => convert free
 438         *      else bad
 439         * If have hint:
 440         *      check if hint fits in good => OK
 441         *      check if hint fits in good | free => convert free
 442         * Otherwise:
 443         *      search in good, found => OK
 444         *      search in good | free, found => convert free
 445         *      search in good | compat | free, found => convert free.
 446         */
 447
 448#ifdef CONFIG_PPC_64K_PAGES
 449        /* If we support combo pages, we can allow 64k pages in 4k slices */
 450        if (psize == MMU_PAGE_64K) {
 451                compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K);
 452                if (fixed)
 453                        or_mask(good_mask, compat_mask);
 454        }
 455#endif
 456
 457        /* First check hint if it's valid or if we have MAP_FIXED */
 458        if (addr != 0 || fixed) {
 459                /* Build a mask for the requested range */
 460                mask = slice_range_to_mask(addr, len);
 461                slice_print_mask(" mask", mask);
 462
 463                /* Check if we fit in the good mask. If we do, we just return,
 464                 * nothing else to do
 465                 */
 466                if (slice_check_fit(mask, good_mask)) {
 467                        slice_dbg(" fits good !\n");
 468                        return addr;
 469                }
 470        } else {
 471                /* Now let's see if we can find something in the existing
 472                 * slices for that size
 473                 */
 474                newaddr = slice_find_area(mm, len, good_mask, psize, topdown);
 475                if (newaddr != -ENOMEM) {
 476                        /* Found within the good mask, we don't have to setup,
 477                         * we thus return directly
 478                         */
 479                        slice_dbg(" found area at 0x%lx\n", newaddr);
 480                        return newaddr;
 481                }
 482        }
 483
 484        /* We don't fit in the good mask, check what other slices are
 485         * empty and thus can be converted
 486         */
 487        potential_mask = slice_mask_for_free(mm);
 488        or_mask(potential_mask, good_mask);
 489        slice_print_mask(" potential", potential_mask);
 490
 491        if ((addr != 0 || fixed) && slice_check_fit(mask, potential_mask)) {
 492                slice_dbg(" fits potential !\n");
 493                goto convert;
 494        }
 495
 496        /* If we have MAP_FIXED and failed the above steps, then error out */
 497        if (fixed)
 498                return -EBUSY;
 499
 500        slice_dbg(" search...\n");
 501
 502        /* If we had a hint that didn't work out, see if we can fit
 503         * anywhere in the good area.
 504         */
 505        if (addr) {
 506                addr = slice_find_area(mm, len, good_mask, psize, topdown);
 507                if (addr != -ENOMEM) {
 508                        slice_dbg(" found area at 0x%lx\n", addr);
 509                        return addr;
 510                }
 511        }
 512
 513        /* Now let's see if we can find something in the existing slices
 514         * for that size plus free slices
 515         */
 516        addr = slice_find_area(mm, len, potential_mask, psize, topdown);
 517
 518#ifdef CONFIG_PPC_64K_PAGES
 519        if (addr == -ENOMEM && psize == MMU_PAGE_64K) {
 520                /* retry the search with 4k-page slices included */
 521                or_mask(potential_mask, compat_mask);
 522                addr = slice_find_area(mm, len, potential_mask, psize,
 523                                       topdown);
 524        }
 525#endif
 526
 527        if (addr == -ENOMEM)
 528                return -ENOMEM;
 529
 530        mask = slice_range_to_mask(addr, len);
 531        slice_dbg(" found potential area at 0x%lx\n", addr);
 532        slice_print_mask(" mask", mask);
 533
 534 convert:
 535        andnot_mask(mask, good_mask);
 536        andnot_mask(mask, compat_mask);
 537        if (mask.low_slices || mask.high_slices) {
 538                slice_convert(mm, mask, psize);
 539                if (psize > MMU_PAGE_BASE)
 540                        on_each_cpu(slice_flush_segments, mm, 1);
 541        }
 542        return addr;
 543
 544}
 545EXPORT_SYMBOL_GPL(slice_get_unmapped_area);
 546
 547unsigned long arch_get_unmapped_area(struct file *filp,
 548                                     unsigned long addr,
 549                                     unsigned long len,
 550                                     unsigned long pgoff,
 551                                     unsigned long flags)
 552{
 553        return slice_get_unmapped_area(addr, len, flags,
 554                                       current->mm->context.user_psize, 0);
 555}
 556
 557unsigned long arch_get_unmapped_area_topdown(struct file *filp,
 558                                             const unsigned long addr0,
 559                                             const unsigned long len,
 560                                             const unsigned long pgoff,
 561                                             const unsigned long flags)
 562{
 563        return slice_get_unmapped_area(addr0, len, flags,
 564                                       current->mm->context.user_psize, 1);
 565}
 566
 567unsigned int get_slice_psize(struct mm_struct *mm, unsigned long addr)
 568{
 569        unsigned char *hpsizes;
 570        int index, mask_index;
 571
 572        if (addr < SLICE_LOW_TOP) {
 573                u64 lpsizes;
 574                lpsizes = mm->context.low_slices_psize;
 575                index = GET_LOW_SLICE_INDEX(addr);
 576                return (lpsizes >> (index * 4)) & 0xf;
 577        }
 578        hpsizes = mm->context.high_slices_psize;
 579        index = GET_HIGH_SLICE_INDEX(addr);
 580        mask_index = index & 0x1;
 581        return (hpsizes[index >> 1] >> (mask_index * 4)) & 0xf;
 582}
 583EXPORT_SYMBOL_GPL(get_slice_psize);
 584
 585/*
 586 * This is called by hash_page when it needs to do a lazy conversion of
 587 * an address space from real 64K pages to combo 4K pages (typically
 588 * when hitting a non cacheable mapping on a processor or hypervisor
 589 * that won't allow them for 64K pages).
 590 *
 591 * This is also called in init_new_context() to change back the user
 592 * psize from whatever the parent context had it set to
 593 * N.B. This may be called before mm->context.id has been set.
 594 *
 595 * This function will only change the content of the {low,high)_slice_psize
 596 * masks, it will not flush SLBs as this shall be handled lazily by the
 597 * caller.
 598 */
 599void slice_set_user_psize(struct mm_struct *mm, unsigned int psize)
 600{
 601        int index, mask_index;
 602        unsigned char *hpsizes;
 603        unsigned long flags, lpsizes;
 604        unsigned int old_psize;
 605        int i;
 606
 607        slice_dbg("slice_set_user_psize(mm=%p, psize=%d)\n", mm, psize);
 608
 609        spin_lock_irqsave(&slice_convert_lock, flags);
 610
 611        old_psize = mm->context.user_psize;
 612        slice_dbg(" old_psize=%d\n", old_psize);
 613        if (old_psize == psize)
 614                goto bail;
 615
 616        mm->context.user_psize = psize;
 617        wmb();
 618
 619        lpsizes = mm->context.low_slices_psize;
 620        for (i = 0; i < SLICE_NUM_LOW; i++)
 621                if (((lpsizes >> (i * 4)) & 0xf) == old_psize)
 622                        lpsizes = (lpsizes & ~(0xful << (i * 4))) |
 623                                (((unsigned long)psize) << (i * 4));
 624        /* Assign the value back */
 625        mm->context.low_slices_psize = lpsizes;
 626
 627        hpsizes = mm->context.high_slices_psize;
 628        for (i = 0; i < SLICE_NUM_HIGH; i++) {
 629                mask_index = i & 0x1;
 630                index = i >> 1;
 631                if (((hpsizes[index] >> (mask_index * 4)) & 0xf) == old_psize)
 632                        hpsizes[index] = (hpsizes[index] &
 633                                          ~(0xf << (mask_index * 4))) |
 634                                (((unsigned long)psize) << (mask_index * 4));
 635        }
 636
 637
 638
 639
 640        slice_dbg(" lsps=%lx, hsps=%lx\n",
 641                  mm->context.low_slices_psize,
 642                  mm->context.high_slices_psize);
 643
 644 bail:
 645        spin_unlock_irqrestore(&slice_convert_lock, flags);
 646}
 647
 648void slice_set_psize(struct mm_struct *mm, unsigned long address,
 649                     unsigned int psize)
 650{
 651        unsigned char *hpsizes;
 652        unsigned long i, flags;
 653        u64 *lpsizes;
 654
 655        spin_lock_irqsave(&slice_convert_lock, flags);
 656        if (address < SLICE_LOW_TOP) {
 657                i = GET_LOW_SLICE_INDEX(address);
 658                lpsizes = &mm->context.low_slices_psize;
 659                *lpsizes = (*lpsizes & ~(0xful << (i * 4))) |
 660                        ((unsigned long) psize << (i * 4));
 661        } else {
 662                int index, mask_index;
 663                i = GET_HIGH_SLICE_INDEX(address);
 664                hpsizes = mm->context.high_slices_psize;
 665                mask_index = i & 0x1;
 666                index = i >> 1;
 667                hpsizes[index] = (hpsizes[index] &
 668                                  ~(0xf << (mask_index * 4))) |
 669                        (((unsigned long)psize) << (mask_index * 4));
 670        }
 671
 672        spin_unlock_irqrestore(&slice_convert_lock, flags);
 673
 674        copro_flush_all_slbs(mm);
 675}
 676
 677void slice_set_range_psize(struct mm_struct *mm, unsigned long start,
 678                           unsigned long len, unsigned int psize)
 679{
 680        struct slice_mask mask = slice_range_to_mask(start, len);
 681
 682        slice_convert(mm, mask, psize);
 683}
 684
 685#ifdef CONFIG_HUGETLB_PAGE
 686/*
 687 * is_hugepage_only_range() is used by generic code to verify whether
 688 * a normal mmap mapping (non hugetlbfs) is valid on a given area.
 689 *
 690 * until the generic code provides a more generic hook and/or starts
 691 * calling arch get_unmapped_area for MAP_FIXED (which our implementation
 692 * here knows how to deal with), we hijack it to keep standard mappings
 693 * away from us.
 694 *
 695 * because of that generic code limitation, MAP_FIXED mapping cannot
 696 * "convert" back a slice with no VMAs to the standard page size, only
 697 * get_unmapped_area() can. It would be possible to fix it here but I
 698 * prefer working on fixing the generic code instead.
 699 *
 700 * WARNING: This will not work if hugetlbfs isn't enabled since the
 701 * generic code will redefine that function as 0 in that. This is ok
 702 * for now as we only use slices with hugetlbfs enabled. This should
 703 * be fixed as the generic code gets fixed.
 704 */
 705int is_hugepage_only_range(struct mm_struct *mm, unsigned long addr,
 706                           unsigned long len)
 707{
 708        struct slice_mask mask, available;
 709        unsigned int psize = mm->context.user_psize;
 710
 711        mask = slice_range_to_mask(addr, len);
 712        available = slice_mask_for_size(mm, psize);
 713#ifdef CONFIG_PPC_64K_PAGES
 714        /* We need to account for 4k slices too */
 715        if (psize == MMU_PAGE_64K) {
 716                struct slice_mask compat_mask;
 717                compat_mask = slice_mask_for_size(mm, MMU_PAGE_4K);
 718                or_mask(available, compat_mask);
 719        }
 720#endif
 721
 722#if 0 /* too verbose */
 723        slice_dbg("is_hugepage_only_range(mm=%p, addr=%lx, len=%lx)\n",
 724                 mm, addr, len);
 725        slice_print_mask(" mask", mask);
 726        slice_print_mask(" available", available);
 727#endif
 728        return !slice_check_fit(mask, available);
 729}
 730#endif
 731