linux/arch/sparc/mm/tsb.c
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   1// SPDX-License-Identifier: GPL-2.0
   2/* arch/sparc64/mm/tsb.c
   3 *
   4 * Copyright (C) 2006, 2008 David S. Miller <davem@davemloft.net>
   5 */
   6
   7#include <linux/kernel.h>
   8#include <linux/preempt.h>
   9#include <linux/slab.h>
  10#include <linux/mm_types.h>
  11#include <linux/pgtable.h>
  12
  13#include <asm/page.h>
  14#include <asm/mmu_context.h>
  15#include <asm/setup.h>
  16#include <asm/tsb.h>
  17#include <asm/tlb.h>
  18#include <asm/oplib.h>
  19
  20extern struct tsb swapper_tsb[KERNEL_TSB_NENTRIES];
  21
  22static inline unsigned long tsb_hash(unsigned long vaddr, unsigned long hash_shift, unsigned long nentries)
  23{
  24        vaddr >>= hash_shift;
  25        return vaddr & (nentries - 1);
  26}
  27
  28static inline int tag_compare(unsigned long tag, unsigned long vaddr)
  29{
  30        return (tag == (vaddr >> 22));
  31}
  32
  33static void flush_tsb_kernel_range_scan(unsigned long start, unsigned long end)
  34{
  35        unsigned long idx;
  36
  37        for (idx = 0; idx < KERNEL_TSB_NENTRIES; idx++) {
  38                struct tsb *ent = &swapper_tsb[idx];
  39                unsigned long match = idx << 13;
  40
  41                match |= (ent->tag << 22);
  42                if (match >= start && match < end)
  43                        ent->tag = (1UL << TSB_TAG_INVALID_BIT);
  44        }
  45}
  46
  47/* TSB flushes need only occur on the processor initiating the address
  48 * space modification, not on each cpu the address space has run on.
  49 * Only the TLB flush needs that treatment.
  50 */
  51
  52void flush_tsb_kernel_range(unsigned long start, unsigned long end)
  53{
  54        unsigned long v;
  55
  56        if ((end - start) >> PAGE_SHIFT >= 2 * KERNEL_TSB_NENTRIES)
  57                return flush_tsb_kernel_range_scan(start, end);
  58
  59        for (v = start; v < end; v += PAGE_SIZE) {
  60                unsigned long hash = tsb_hash(v, PAGE_SHIFT,
  61                                              KERNEL_TSB_NENTRIES);
  62                struct tsb *ent = &swapper_tsb[hash];
  63
  64                if (tag_compare(ent->tag, v))
  65                        ent->tag = (1UL << TSB_TAG_INVALID_BIT);
  66        }
  67}
  68
  69static void __flush_tsb_one_entry(unsigned long tsb, unsigned long v,
  70                                  unsigned long hash_shift,
  71                                  unsigned long nentries)
  72{
  73        unsigned long tag, ent, hash;
  74
  75        v &= ~0x1UL;
  76        hash = tsb_hash(v, hash_shift, nentries);
  77        ent = tsb + (hash * sizeof(struct tsb));
  78        tag = (v >> 22UL);
  79
  80        tsb_flush(ent, tag);
  81}
  82
  83static void __flush_tsb_one(struct tlb_batch *tb, unsigned long hash_shift,
  84                            unsigned long tsb, unsigned long nentries)
  85{
  86        unsigned long i;
  87
  88        for (i = 0; i < tb->tlb_nr; i++)
  89                __flush_tsb_one_entry(tsb, tb->vaddrs[i], hash_shift, nentries);
  90}
  91
  92#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
  93static void __flush_huge_tsb_one_entry(unsigned long tsb, unsigned long v,
  94                                       unsigned long hash_shift,
  95                                       unsigned long nentries,
  96                                       unsigned int hugepage_shift)
  97{
  98        unsigned int hpage_entries;
  99        unsigned int i;
 100
 101        hpage_entries = 1 << (hugepage_shift - hash_shift);
 102        for (i = 0; i < hpage_entries; i++)
 103                __flush_tsb_one_entry(tsb, v + (i << hash_shift), hash_shift,
 104                                      nentries);
 105}
 106
 107static void __flush_huge_tsb_one(struct tlb_batch *tb, unsigned long hash_shift,
 108                                 unsigned long tsb, unsigned long nentries,
 109                                 unsigned int hugepage_shift)
 110{
 111        unsigned long i;
 112
 113        for (i = 0; i < tb->tlb_nr; i++)
 114                __flush_huge_tsb_one_entry(tsb, tb->vaddrs[i], hash_shift,
 115                                           nentries, hugepage_shift);
 116}
 117#endif
 118
 119void flush_tsb_user(struct tlb_batch *tb)
 120{
 121        struct mm_struct *mm = tb->mm;
 122        unsigned long nentries, base, flags;
 123
 124        spin_lock_irqsave(&mm->context.lock, flags);
 125
 126        if (tb->hugepage_shift < REAL_HPAGE_SHIFT) {
 127                base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
 128                nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
 129                if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 130                        base = __pa(base);
 131                if (tb->hugepage_shift == PAGE_SHIFT)
 132                        __flush_tsb_one(tb, PAGE_SHIFT, base, nentries);
 133#if defined(CONFIG_HUGETLB_PAGE)
 134                else
 135                        __flush_huge_tsb_one(tb, PAGE_SHIFT, base, nentries,
 136                                             tb->hugepage_shift);
 137#endif
 138        }
 139#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 140        else if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
 141                base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
 142                nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
 143                if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 144                        base = __pa(base);
 145                __flush_huge_tsb_one(tb, REAL_HPAGE_SHIFT, base, nentries,
 146                                     tb->hugepage_shift);
 147        }
 148#endif
 149        spin_unlock_irqrestore(&mm->context.lock, flags);
 150}
 151
 152void flush_tsb_user_page(struct mm_struct *mm, unsigned long vaddr,
 153                         unsigned int hugepage_shift)
 154{
 155        unsigned long nentries, base, flags;
 156
 157        spin_lock_irqsave(&mm->context.lock, flags);
 158
 159        if (hugepage_shift < REAL_HPAGE_SHIFT) {
 160                base = (unsigned long) mm->context.tsb_block[MM_TSB_BASE].tsb;
 161                nentries = mm->context.tsb_block[MM_TSB_BASE].tsb_nentries;
 162                if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 163                        base = __pa(base);
 164                if (hugepage_shift == PAGE_SHIFT)
 165                        __flush_tsb_one_entry(base, vaddr, PAGE_SHIFT,
 166                                              nentries);
 167#if defined(CONFIG_HUGETLB_PAGE)
 168                else
 169                        __flush_huge_tsb_one_entry(base, vaddr, PAGE_SHIFT,
 170                                                   nentries, hugepage_shift);
 171#endif
 172        }
 173#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 174        else if (mm->context.tsb_block[MM_TSB_HUGE].tsb) {
 175                base = (unsigned long) mm->context.tsb_block[MM_TSB_HUGE].tsb;
 176                nentries = mm->context.tsb_block[MM_TSB_HUGE].tsb_nentries;
 177                if (tlb_type == cheetah_plus || tlb_type == hypervisor)
 178                        base = __pa(base);
 179                __flush_huge_tsb_one_entry(base, vaddr, REAL_HPAGE_SHIFT,
 180                                           nentries, hugepage_shift);
 181        }
 182#endif
 183        spin_unlock_irqrestore(&mm->context.lock, flags);
 184}
 185
 186#define HV_PGSZ_IDX_BASE        HV_PGSZ_IDX_8K
 187#define HV_PGSZ_MASK_BASE       HV_PGSZ_MASK_8K
 188
 189#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 190#define HV_PGSZ_IDX_HUGE        HV_PGSZ_IDX_4MB
 191#define HV_PGSZ_MASK_HUGE       HV_PGSZ_MASK_4MB
 192#endif
 193
 194static void setup_tsb_params(struct mm_struct *mm, unsigned long tsb_idx, unsigned long tsb_bytes)
 195{
 196        unsigned long tsb_reg, base, tsb_paddr;
 197        unsigned long page_sz, tte;
 198
 199        mm->context.tsb_block[tsb_idx].tsb_nentries =
 200                tsb_bytes / sizeof(struct tsb);
 201
 202        switch (tsb_idx) {
 203        case MM_TSB_BASE:
 204                base = TSBMAP_8K_BASE;
 205                break;
 206#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 207        case MM_TSB_HUGE:
 208                base = TSBMAP_4M_BASE;
 209                break;
 210#endif
 211        default:
 212                BUG();
 213        }
 214
 215        tte = pgprot_val(PAGE_KERNEL_LOCKED);
 216        tsb_paddr = __pa(mm->context.tsb_block[tsb_idx].tsb);
 217        BUG_ON(tsb_paddr & (tsb_bytes - 1UL));
 218
 219        /* Use the smallest page size that can map the whole TSB
 220         * in one TLB entry.
 221         */
 222        switch (tsb_bytes) {
 223        case 8192 << 0:
 224                tsb_reg = 0x0UL;
 225#ifdef DCACHE_ALIASING_POSSIBLE
 226                base += (tsb_paddr & 8192);
 227#endif
 228                page_sz = 8192;
 229                break;
 230
 231        case 8192 << 1:
 232                tsb_reg = 0x1UL;
 233                page_sz = 64 * 1024;
 234                break;
 235
 236        case 8192 << 2:
 237                tsb_reg = 0x2UL;
 238                page_sz = 64 * 1024;
 239                break;
 240
 241        case 8192 << 3:
 242                tsb_reg = 0x3UL;
 243                page_sz = 64 * 1024;
 244                break;
 245
 246        case 8192 << 4:
 247                tsb_reg = 0x4UL;
 248                page_sz = 512 * 1024;
 249                break;
 250
 251        case 8192 << 5:
 252                tsb_reg = 0x5UL;
 253                page_sz = 512 * 1024;
 254                break;
 255
 256        case 8192 << 6:
 257                tsb_reg = 0x6UL;
 258                page_sz = 512 * 1024;
 259                break;
 260
 261        case 8192 << 7:
 262                tsb_reg = 0x7UL;
 263                page_sz = 4 * 1024 * 1024;
 264                break;
 265
 266        default:
 267                printk(KERN_ERR "TSB[%s:%d]: Impossible TSB size %lu, killing process.\n",
 268                       current->comm, current->pid, tsb_bytes);
 269                do_exit(SIGSEGV);
 270        }
 271        tte |= pte_sz_bits(page_sz);
 272
 273        if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
 274                /* Physical mapping, no locked TLB entry for TSB.  */
 275                tsb_reg |= tsb_paddr;
 276
 277                mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
 278                mm->context.tsb_block[tsb_idx].tsb_map_vaddr = 0;
 279                mm->context.tsb_block[tsb_idx].tsb_map_pte = 0;
 280        } else {
 281                tsb_reg |= base;
 282                tsb_reg |= (tsb_paddr & (page_sz - 1UL));
 283                tte |= (tsb_paddr & ~(page_sz - 1UL));
 284
 285                mm->context.tsb_block[tsb_idx].tsb_reg_val = tsb_reg;
 286                mm->context.tsb_block[tsb_idx].tsb_map_vaddr = base;
 287                mm->context.tsb_block[tsb_idx].tsb_map_pte = tte;
 288        }
 289
 290        /* Setup the Hypervisor TSB descriptor.  */
 291        if (tlb_type == hypervisor) {
 292                struct hv_tsb_descr *hp = &mm->context.tsb_descr[tsb_idx];
 293
 294                switch (tsb_idx) {
 295                case MM_TSB_BASE:
 296                        hp->pgsz_idx = HV_PGSZ_IDX_BASE;
 297                        break;
 298#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 299                case MM_TSB_HUGE:
 300                        hp->pgsz_idx = HV_PGSZ_IDX_HUGE;
 301                        break;
 302#endif
 303                default:
 304                        BUG();
 305                }
 306                hp->assoc = 1;
 307                hp->num_ttes = tsb_bytes / 16;
 308                hp->ctx_idx = 0;
 309                switch (tsb_idx) {
 310                case MM_TSB_BASE:
 311                        hp->pgsz_mask = HV_PGSZ_MASK_BASE;
 312                        break;
 313#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 314                case MM_TSB_HUGE:
 315                        hp->pgsz_mask = HV_PGSZ_MASK_HUGE;
 316                        break;
 317#endif
 318                default:
 319                        BUG();
 320                }
 321                hp->tsb_base = tsb_paddr;
 322                hp->resv = 0;
 323        }
 324}
 325
 326struct kmem_cache *pgtable_cache __read_mostly;
 327
 328static struct kmem_cache *tsb_caches[8] __read_mostly;
 329
 330static const char *tsb_cache_names[8] = {
 331        "tsb_8KB",
 332        "tsb_16KB",
 333        "tsb_32KB",
 334        "tsb_64KB",
 335        "tsb_128KB",
 336        "tsb_256KB",
 337        "tsb_512KB",
 338        "tsb_1MB",
 339};
 340
 341void __init pgtable_cache_init(void)
 342{
 343        unsigned long i;
 344
 345        pgtable_cache = kmem_cache_create("pgtable_cache",
 346                                          PAGE_SIZE, PAGE_SIZE,
 347                                          0,
 348                                          _clear_page);
 349        if (!pgtable_cache) {
 350                prom_printf("pgtable_cache_init(): Could not create!\n");
 351                prom_halt();
 352        }
 353
 354        for (i = 0; i < ARRAY_SIZE(tsb_cache_names); i++) {
 355                unsigned long size = 8192 << i;
 356                const char *name = tsb_cache_names[i];
 357
 358                tsb_caches[i] = kmem_cache_create(name,
 359                                                  size, size,
 360                                                  0, NULL);
 361                if (!tsb_caches[i]) {
 362                        prom_printf("Could not create %s cache\n", name);
 363                        prom_halt();
 364                }
 365        }
 366}
 367
 368int sysctl_tsb_ratio = -2;
 369
 370static unsigned long tsb_size_to_rss_limit(unsigned long new_size)
 371{
 372        unsigned long num_ents = (new_size / sizeof(struct tsb));
 373
 374        if (sysctl_tsb_ratio < 0)
 375                return num_ents - (num_ents >> -sysctl_tsb_ratio);
 376        else
 377                return num_ents + (num_ents >> sysctl_tsb_ratio);
 378}
 379
 380/* When the RSS of an address space exceeds tsb_rss_limit for a TSB,
 381 * do_sparc64_fault() invokes this routine to try and grow it.
 382 *
 383 * When we reach the maximum TSB size supported, we stick ~0UL into
 384 * tsb_rss_limit for that TSB so the grow checks in do_sparc64_fault()
 385 * will not trigger any longer.
 386 *
 387 * The TSB can be anywhere from 8K to 1MB in size, in increasing powers
 388 * of two.  The TSB must be aligned to it's size, so f.e. a 512K TSB
 389 * must be 512K aligned.  It also must be physically contiguous, so we
 390 * cannot use vmalloc().
 391 *
 392 * The idea here is to grow the TSB when the RSS of the process approaches
 393 * the number of entries that the current TSB can hold at once.  Currently,
 394 * we trigger when the RSS hits 3/4 of the TSB capacity.
 395 */
 396void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long rss)
 397{
 398        unsigned long max_tsb_size = 1 * 1024 * 1024;
 399        unsigned long new_size, old_size, flags;
 400        struct tsb *old_tsb, *new_tsb;
 401        unsigned long new_cache_index, old_cache_index;
 402        unsigned long new_rss_limit;
 403        gfp_t gfp_flags;
 404
 405        if (max_tsb_size > (PAGE_SIZE << MAX_ORDER))
 406                max_tsb_size = (PAGE_SIZE << MAX_ORDER);
 407
 408        new_cache_index = 0;
 409        for (new_size = 8192; new_size < max_tsb_size; new_size <<= 1UL) {
 410                new_rss_limit = tsb_size_to_rss_limit(new_size);
 411                if (new_rss_limit > rss)
 412                        break;
 413                new_cache_index++;
 414        }
 415
 416        if (new_size == max_tsb_size)
 417                new_rss_limit = ~0UL;
 418
 419retry_tsb_alloc:
 420        gfp_flags = GFP_KERNEL;
 421        if (new_size > (PAGE_SIZE * 2))
 422                gfp_flags |= __GFP_NOWARN | __GFP_NORETRY;
 423
 424        new_tsb = kmem_cache_alloc_node(tsb_caches[new_cache_index],
 425                                        gfp_flags, numa_node_id());
 426        if (unlikely(!new_tsb)) {
 427                /* Not being able to fork due to a high-order TSB
 428                 * allocation failure is very bad behavior.  Just back
 429                 * down to a 0-order allocation and force no TSB
 430                 * growing for this address space.
 431                 */
 432                if (mm->context.tsb_block[tsb_index].tsb == NULL &&
 433                    new_cache_index > 0) {
 434                        new_cache_index = 0;
 435                        new_size = 8192;
 436                        new_rss_limit = ~0UL;
 437                        goto retry_tsb_alloc;
 438                }
 439
 440                /* If we failed on a TSB grow, we are under serious
 441                 * memory pressure so don't try to grow any more.
 442                 */
 443                if (mm->context.tsb_block[tsb_index].tsb != NULL)
 444                        mm->context.tsb_block[tsb_index].tsb_rss_limit = ~0UL;
 445                return;
 446        }
 447
 448        /* Mark all tags as invalid.  */
 449        tsb_init(new_tsb, new_size);
 450
 451        /* Ok, we are about to commit the changes.  If we are
 452         * growing an existing TSB the locking is very tricky,
 453         * so WATCH OUT!
 454         *
 455         * We have to hold mm->context.lock while committing to the
 456         * new TSB, this synchronizes us with processors in
 457         * flush_tsb_user() and switch_mm() for this address space.
 458         *
 459         * But even with that lock held, processors run asynchronously
 460         * accessing the old TSB via TLB miss handling.  This is OK
 461         * because those actions are just propagating state from the
 462         * Linux page tables into the TSB, page table mappings are not
 463         * being changed.  If a real fault occurs, the processor will
 464         * synchronize with us when it hits flush_tsb_user(), this is
 465         * also true for the case where vmscan is modifying the page
 466         * tables.  The only thing we need to be careful with is to
 467         * skip any locked TSB entries during copy_tsb().
 468         *
 469         * When we finish committing to the new TSB, we have to drop
 470         * the lock and ask all other cpus running this address space
 471         * to run tsb_context_switch() to see the new TSB table.
 472         */
 473        spin_lock_irqsave(&mm->context.lock, flags);
 474
 475        old_tsb = mm->context.tsb_block[tsb_index].tsb;
 476        old_cache_index =
 477                (mm->context.tsb_block[tsb_index].tsb_reg_val & 0x7UL);
 478        old_size = (mm->context.tsb_block[tsb_index].tsb_nentries *
 479                    sizeof(struct tsb));
 480
 481
 482        /* Handle multiple threads trying to grow the TSB at the same time.
 483         * One will get in here first, and bump the size and the RSS limit.
 484         * The others will get in here next and hit this check.
 485         */
 486        if (unlikely(old_tsb &&
 487                     (rss < mm->context.tsb_block[tsb_index].tsb_rss_limit))) {
 488                spin_unlock_irqrestore(&mm->context.lock, flags);
 489
 490                kmem_cache_free(tsb_caches[new_cache_index], new_tsb);
 491                return;
 492        }
 493
 494        mm->context.tsb_block[tsb_index].tsb_rss_limit = new_rss_limit;
 495
 496        if (old_tsb) {
 497                extern void copy_tsb(unsigned long old_tsb_base,
 498                                     unsigned long old_tsb_size,
 499                                     unsigned long new_tsb_base,
 500                                     unsigned long new_tsb_size,
 501                                     unsigned long page_size_shift);
 502                unsigned long old_tsb_base = (unsigned long) old_tsb;
 503                unsigned long new_tsb_base = (unsigned long) new_tsb;
 504
 505                if (tlb_type == cheetah_plus || tlb_type == hypervisor) {
 506                        old_tsb_base = __pa(old_tsb_base);
 507                        new_tsb_base = __pa(new_tsb_base);
 508                }
 509                copy_tsb(old_tsb_base, old_size, new_tsb_base, new_size,
 510                        tsb_index == MM_TSB_BASE ?
 511                        PAGE_SHIFT : REAL_HPAGE_SHIFT);
 512        }
 513
 514        mm->context.tsb_block[tsb_index].tsb = new_tsb;
 515        setup_tsb_params(mm, tsb_index, new_size);
 516
 517        spin_unlock_irqrestore(&mm->context.lock, flags);
 518
 519        /* If old_tsb is NULL, we're being invoked for the first time
 520         * from init_new_context().
 521         */
 522        if (old_tsb) {
 523                /* Reload it on the local cpu.  */
 524                tsb_context_switch(mm);
 525
 526                /* Now force other processors to do the same.  */
 527                preempt_disable();
 528                smp_tsb_sync(mm);
 529                preempt_enable();
 530
 531                /* Now it is safe to free the old tsb.  */
 532                kmem_cache_free(tsb_caches[old_cache_index], old_tsb);
 533        }
 534}
 535
 536int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 537{
 538        unsigned long mm_rss = get_mm_rss(mm);
 539#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 540        unsigned long saved_hugetlb_pte_count;
 541        unsigned long saved_thp_pte_count;
 542#endif
 543        unsigned int i;
 544
 545        spin_lock_init(&mm->context.lock);
 546
 547        mm->context.sparc64_ctx_val = 0UL;
 548
 549        mm->context.tag_store = NULL;
 550        spin_lock_init(&mm->context.tag_lock);
 551
 552#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 553        /* We reset them to zero because the fork() page copying
 554         * will re-increment the counters as the parent PTEs are
 555         * copied into the child address space.
 556         */
 557        saved_hugetlb_pte_count = mm->context.hugetlb_pte_count;
 558        saved_thp_pte_count = mm->context.thp_pte_count;
 559        mm->context.hugetlb_pte_count = 0;
 560        mm->context.thp_pte_count = 0;
 561
 562        mm_rss -= saved_thp_pte_count * (HPAGE_SIZE / PAGE_SIZE);
 563#endif
 564
 565        /* copy_mm() copies over the parent's mm_struct before calling
 566         * us, so we need to zero out the TSB pointer or else tsb_grow()
 567         * will be confused and think there is an older TSB to free up.
 568         */
 569        for (i = 0; i < MM_NUM_TSBS; i++)
 570                mm->context.tsb_block[i].tsb = NULL;
 571
 572        /* If this is fork, inherit the parent's TSB size.  We would
 573         * grow it to that size on the first page fault anyways.
 574         */
 575        tsb_grow(mm, MM_TSB_BASE, mm_rss);
 576
 577#if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
 578        if (unlikely(saved_hugetlb_pte_count + saved_thp_pte_count))
 579                tsb_grow(mm, MM_TSB_HUGE,
 580                         (saved_hugetlb_pte_count + saved_thp_pte_count) *
 581                         REAL_HPAGE_PER_HPAGE);
 582#endif
 583
 584        if (unlikely(!mm->context.tsb_block[MM_TSB_BASE].tsb))
 585                return -ENOMEM;
 586
 587        return 0;
 588}
 589
 590static void tsb_destroy_one(struct tsb_config *tp)
 591{
 592        unsigned long cache_index;
 593
 594        if (!tp->tsb)
 595                return;
 596        cache_index = tp->tsb_reg_val & 0x7UL;
 597        kmem_cache_free(tsb_caches[cache_index], tp->tsb);
 598        tp->tsb = NULL;
 599        tp->tsb_reg_val = 0UL;
 600}
 601
 602void destroy_context(struct mm_struct *mm)
 603{
 604        unsigned long flags, i;
 605
 606        for (i = 0; i < MM_NUM_TSBS; i++)
 607                tsb_destroy_one(&mm->context.tsb_block[i]);
 608
 609        spin_lock_irqsave(&ctx_alloc_lock, flags);
 610
 611        if (CTX_VALID(mm->context)) {
 612                unsigned long nr = CTX_NRBITS(mm->context);
 613                mmu_context_bmap[nr>>6] &= ~(1UL << (nr & 63));
 614        }
 615
 616        spin_unlock_irqrestore(&ctx_alloc_lock, flags);
 617
 618        /* If ADI tag storage was allocated for this task, free it */
 619        if (mm->context.tag_store) {
 620                tag_storage_desc_t *tag_desc;
 621                unsigned long max_desc;
 622                unsigned char *tags;
 623
 624                tag_desc = mm->context.tag_store;
 625                max_desc = PAGE_SIZE/sizeof(tag_storage_desc_t);
 626                for (i = 0; i < max_desc; i++) {
 627                        tags = tag_desc->tags;
 628                        tag_desc->tags = NULL;
 629                        kfree(tags);
 630                        tag_desc++;
 631                }
 632                kfree(mm->context.tag_store);
 633                mm->context.tag_store = NULL;
 634        }
 635}
 636
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