arch/powerpc/platforms/pseries/lpar.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * pSeries_lpar.c
   4  * Copyright (C) 2001 Todd Inglett, IBM Corporation
   5  *
   6  * pSeries LPAR support.
   7  */
   8
   9 /* Enables debugging of low-level hash table routines - careful! */
  10 #undef DEBUG
  11 #define pr_fmt(fmt) "lpar: " fmt
  12
  13 #include <linux/kernel.h>
  14 #include <linux/dma-mapping.h>
  15 #include <linux/console.h>
  16 #include <linux/export.h>
  17 #include <linux/jump_label.h>
  18 #include <linux/delay.h>
  19 #include <linux/stop_machine.h>
  20 #include <asm/processor.h>
  21 #include <asm/mmu.h>
  22 #include <asm/page.h>
  23 #include <asm/pgtable.h>
  24 #include <asm/machdep.h>
  25 #include <asm/mmu_context.h>
  26 #include <asm/iommu.h>
  27 #include <asm/tlb.h>
  28 #include <asm/prom.h>
  29 #include <asm/cputable.h>
  30 #include <asm/udbg.h>
  31 #include <asm/smp.h>
  32 #include <asm/trace.h>
  33 #include <asm/firmware.h>
  34 #include <asm/plpar_wrappers.h>
  35 #include <asm/kexec.h>
  36 #include <asm/fadump.h>
  37 #include <asm/asm-prototypes.h>
  38 #include <asm/debugfs.h>
  39
  40 #include "pseries.h"
  41
  42 /* Flag bits for H_BULK_REMOVE */
  43 #define HBR_REQUEST     0x4000000000000000UL
  44 #define HBR_RESPONSE    0x8000000000000000UL
  45 #define HBR_END         0xc000000000000000UL
  46 #define HBR_AVPN        0x0200000000000000UL
  47 #define HBR_ANDCOND     0x0100000000000000UL
  48
  49
  50 /* in hvCall.S */
  51 EXPORT_SYMBOL(plpar_hcall);
  52 EXPORT_SYMBOL(plpar_hcall9);
  53 EXPORT_SYMBOL(plpar_hcall_norets);
  54
  55 void vpa_init(int cpu)
  56 {
  57         int hwcpu = get_hard_smp_processor_id(cpu);
  58         unsigned long addr;
  59         long ret;
  60         struct paca_struct *pp;
  61         struct dtl_entry *dtl;
  62
  63         /*
  64          * The spec says it "may be problematic" if CPU x registers the VPA of
  65          * CPU y. We should never do that, but wail if we ever do.
  66          */
  67         WARN_ON(cpu != smp_processor_id());
  68
  69         if (cpu_has_feature(CPU_FTR_ALTIVEC))
  70                 lppaca_of(cpu).vmxregs_in_use = 1;
  71
  72         if (cpu_has_feature(CPU_FTR_ARCH_207S))
  73                 lppaca_of(cpu).ebb_regs_in_use = 1;
  74
  75         addr = __pa(&lppaca_of(cpu));
  76         ret = register_vpa(hwcpu, addr);
  77
  78         if (ret) {
  79                 pr_err("WARNING: VPA registration for cpu %d (hw %d) of area "
  80                        "%lx failed with %ld\n", cpu, hwcpu, addr, ret);
  81                 return;
  82         }
  83
  84 #ifdef CONFIG_PPC_BOOK3S_64
  85         /*
  86          * PAPR says this feature is SLB-Buffer but firmware never
  87          * reports that.  All SPLPAR support SLB shadow buffer.
  88          */
  89         if (!radix_enabled() && firmware_has_feature(FW_FEATURE_SPLPAR)) {
  90                 addr = __pa(paca_ptrs[cpu]->slb_shadow_ptr);
  91                 ret = register_slb_shadow(hwcpu, addr);
  92                 if (ret)
  93                         pr_err("WARNING: SLB shadow buffer registration for "
  94                                "cpu %d (hw %d) of area %lx failed with %ld\n",
  95                                cpu, hwcpu, addr, ret);
  96         }
  97 #endif /* CONFIG_PPC_BOOK3S_64 */
  98
  99         /*
 100          * Register dispatch trace log, if one has been allocated.
 101          */
 102         pp = paca_ptrs[cpu];
 103         dtl = pp->dispatch_log;
 104         if (dtl) {
 105                 pp->dtl_ridx = 0;
 106                 pp->dtl_curr = dtl;
 107                 lppaca_of(cpu).dtl_idx = 0;
 108
 109                 /* hypervisor reads buffer length from this field */
 110                 dtl->enqueue_to_dispatch_time = cpu_to_be32(DISPATCH_LOG_BYTES);
 111                 ret = register_dtl(hwcpu, __pa(dtl));
 112                 if (ret)
 113                         pr_err("WARNING: DTL registration of cpu %d (hw %d) "
 114                                "failed with %ld\n", smp_processor_id(),
 115                                hwcpu, ret);
 116                 lppaca_of(cpu).dtl_enable_mask = 2;
 117         }
 118 }
 119
 120 #ifdef CONFIG_PPC_BOOK3S_64
 121
 122 static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
 123                                      unsigned long vpn, unsigned long pa,
 124                                      unsigned long rflags, unsigned long vflags,
 125                                      int psize, int apsize, int ssize)
 126 {
 127         unsigned long lpar_rc;
 128         unsigned long flags;
 129         unsigned long slot;
 130         unsigned long hpte_v, hpte_r;
 131
 132         if (!(vflags & HPTE_V_BOLTED))
 133                 pr_devel("hpte_insert(group=%lx, vpn=%016lx, "
 134                          "pa=%016lx, rflags=%lx, vflags=%lx, psize=%d)\n",
 135                          hpte_group, vpn,  pa, rflags, vflags, psize);
 136
 137         hpte_v = hpte_encode_v(vpn, psize, apsize, ssize) | vflags | HPTE_V_VALID;
 138         hpte_r = hpte_encode_r(pa, psize, apsize) | rflags;
 139
 140         if (!(vflags & HPTE_V_BOLTED))
 141                 pr_devel(" hpte_v=%016lx, hpte_r=%016lx\n", hpte_v, hpte_r);
 142
 143         /* Now fill in the actual HPTE */
 144         /* Set CEC cookie to 0         */
 145         /* Zero page = 0               */
 146         /* I-cache Invalidate = 0      */
 147         /* I-cache synchronize = 0     */
 148         /* Exact = 0                   */
 149         flags = 0;
 150
 151         if (firmware_has_feature(FW_FEATURE_XCMO) && !(hpte_r & HPTE_R_N))
 152                 flags |= H_COALESCE_CAND;
 153
 154         lpar_rc = plpar_pte_enter(flags, hpte_group, hpte_v, hpte_r, &slot);
 155         if (unlikely(lpar_rc == H_PTEG_FULL)) {
 156                 pr_devel("Hash table group is full\n");
 157                 return -1;
 158         }
 159
 160         /*
 161          * Since we try and ioremap PHBs we don't own, the pte insert
 162          * will fail. However we must catch the failure in hash_page
 163          * or we will loop forever, so return -2 in this case.
 164          */
 165         if (unlikely(lpar_rc != H_SUCCESS)) {
 166                 pr_err("Failed hash pte insert with error %ld\n", lpar_rc);
 167                 return -2;
 168         }
 169         if (!(vflags & HPTE_V_BOLTED))
 170                 pr_devel(" -> slot: %lu\n", slot & 7);
 171
 172         /* Because of iSeries, we have to pass down the secondary
 173          * bucket bit here as well
 174          */
 175         return (slot & 7) | (!!(vflags & HPTE_V_SECONDARY) << 3);
 176 }
 177
 178 static DEFINE_SPINLOCK(pSeries_lpar_tlbie_lock);
 179
 180 static long pSeries_lpar_hpte_remove(unsigned long hpte_group)
 181 {
 182         unsigned long slot_offset;
 183         unsigned long lpar_rc;
 184         int i;
 185         unsigned long dummy1, dummy2;
 186
 187         /* pick a random slot to start at */
 188         slot_offset = mftb() & 0x7;
 189
 190         for (i = 0; i < HPTES_PER_GROUP; i++) {
 191
 192                 /* don't remove a bolted entry */
 193                 lpar_rc = plpar_pte_remove(H_ANDCOND, hpte_group + slot_offset,
 194                                            (0x1UL << 4), &dummy1, &dummy2);
 195                 if (lpar_rc == H_SUCCESS)
 196                         return i;
 197
 198                 /*
 199                  * The test for adjunct partition is performed before the
 200                  * ANDCOND test.  H_RESOURCE may be returned, so we need to
 201                  * check for that as well.
 202                  */
 203                 BUG_ON(lpar_rc != H_NOT_FOUND && lpar_rc != H_RESOURCE);
 204
 205                 slot_offset++;
 206                 slot_offset &= 0x7;
 207         }
 208
 209         return -1;
 210 }
 211
 212 static void manual_hpte_clear_all(void)
 213 {
 214         unsigned long size_bytes = 1UL << ppc64_pft_size;
 215         unsigned long hpte_count = size_bytes >> 4;
 216         struct {
 217                 unsigned long pteh;
 218                 unsigned long ptel;
 219         } ptes[4];
 220         long lpar_rc;
 221         unsigned long i, j;
 222
 223         /* Read in batches of 4,
 224          * invalidate only valid entries not in the VRMA
 225          * hpte_count will be a multiple of 4
 226          */
 227         for (i = 0; i < hpte_count; i += 4) {
 228                 lpar_rc = plpar_pte_read_4_raw(0, i, (void *)ptes);
 229                 if (lpar_rc != H_SUCCESS) {
 230                         pr_info("Failed to read hash page table at %ld err %ld\n",
 231                                 i, lpar_rc);
 232                         continue;
 233                 }
 234                 for (j = 0; j < 4; j++){
 235                         if ((ptes[j].pteh & HPTE_V_VRMA_MASK) ==
 236                                 HPTE_V_VRMA_MASK)
 237                                 continue;
 238                         if (ptes[j].pteh & HPTE_V_VALID)
 239                                 plpar_pte_remove_raw(0, i + j, 0,
 240                                         &(ptes[j].pteh), &(ptes[j].ptel));
 241                 }
 242         }
 243 }
 244
 245 static int hcall_hpte_clear_all(void)
 246 {
 247         int rc;
 248
 249         do {
 250                 rc = plpar_hcall_norets(H_CLEAR_HPT);
 251         } while (rc == H_CONTINUE);
 252
 253         return rc;
 254 }
 255
 256 static void pseries_hpte_clear_all(void)
 257 {
 258         int rc;
 259
 260         rc = hcall_hpte_clear_all();
 261         if (rc != H_SUCCESS)
 262                 manual_hpte_clear_all();
 263
 264 #ifdef __LITTLE_ENDIAN__
 265         /*
 266          * Reset exceptions to big endian.
 267          *
 268          * FIXME this is a hack for kexec, we need to reset the exception
 269          * endian before starting the new kernel and this is a convenient place
 270          * to do it.
 271          *
 272          * This is also called on boot when a fadump happens. In that case we
 273          * must not change the exception endian mode.
 274          */
 275         if (firmware_has_feature(FW_FEATURE_SET_MODE) && !is_fadump_active())
 276                 pseries_big_endian_exceptions();
 277 #endif
 278 }
 279
 280 /*
 281  * NOTE: for updatepp ops we are fortunate that the linux "newpp" bits and
 282  * the low 3 bits of flags happen to line up.  So no transform is needed.
 283  * We can probably optimize here and assume the high bits of newpp are
 284  * already zero.  For now I am paranoid.
 285  */
 286 static long pSeries_lpar_hpte_updatepp(unsigned long slot,
 287                                        unsigned long newpp,
 288                                        unsigned long vpn,
 289                                        int psize, int apsize,
 290                                        int ssize, unsigned long inv_flags)
 291 {
 292         unsigned long lpar_rc;
 293         unsigned long flags;
 294         unsigned long want_v;
 295
 296         want_v = hpte_encode_avpn(vpn, psize, ssize);
 297
 298         flags = (newpp & 7) | H_AVPN;
 299         if (mmu_has_feature(MMU_FTR_KERNEL_RO))
 300                 /* Move pp0 into bit 8 (IBM 55) */
 301                 flags |= (newpp & HPTE_R_PP0) >> 55;
 302
 303         pr_devel("    update: avpnv=%016lx, hash=%016lx, f=%lx, psize: %d ...",
 304                  want_v, slot, flags, psize);
 305
 306         lpar_rc = plpar_pte_protect(flags, slot, want_v);
 307
 308         if (lpar_rc == H_NOT_FOUND) {
 309                 pr_devel("not found !\n");
 310                 return -1;
 311         }
 312
 313         pr_devel("ok\n");
 314
 315         BUG_ON(lpar_rc != H_SUCCESS);
 316
 317         return 0;
 318 }
 319
 320 static long __pSeries_lpar_hpte_find(unsigned long want_v, unsigned long hpte_group)
 321 {
 322         long lpar_rc;
 323         unsigned long i, j;
 324         struct {
 325                 unsigned long pteh;
 326                 unsigned long ptel;
 327         } ptes[4];
 328
 329         for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) {
 330
 331                 lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes);
 332                 if (lpar_rc != H_SUCCESS) {
 333                         pr_info("Failed to read hash page table at %ld err %ld\n",
 334                                 hpte_group, lpar_rc);
 335                         continue;
 336                 }
 337
 338                 for (j = 0; j < 4; j++) {
 339                         if (HPTE_V_COMPARE(ptes[j].pteh, want_v) &&
 340                             (ptes[j].pteh & HPTE_V_VALID))
 341                                 return i + j;
 342                 }
 343         }
 344
 345         return -1;
 346 }
 347
 348 static long pSeries_lpar_hpte_find(unsigned long vpn, int psize, int ssize)
 349 {
 350         long slot;
 351         unsigned long hash;
 352         unsigned long want_v;
 353         unsigned long hpte_group;
 354
 355         hash = hpt_hash(vpn, mmu_psize_defs[psize].shift, ssize);
 356         want_v = hpte_encode_avpn(vpn, psize, ssize);
 357
 358         /* Bolted entries are always in the primary group */
 359         hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 360         slot = __pSeries_lpar_hpte_find(want_v, hpte_group);
 361         if (slot < 0)
 362                 return -1;
 363         return hpte_group + slot;
 364 }
 365
 366 static void pSeries_lpar_hpte_updateboltedpp(unsigned long newpp,
 367                                              unsigned long ea,
 368                                              int psize, int ssize)
 369 {
 370         unsigned long vpn;
 371         unsigned long lpar_rc, slot, vsid, flags;
 372
 373         vsid = get_kernel_vsid(ea, ssize);
 374         vpn = hpt_vpn(ea, vsid, ssize);
 375
 376         slot = pSeries_lpar_hpte_find(vpn, psize, ssize);
 377         BUG_ON(slot == -1);
 378
 379         flags = newpp & 7;
 380         if (mmu_has_feature(MMU_FTR_KERNEL_RO))
 381                 /* Move pp0 into bit 8 (IBM 55) */
 382                 flags |= (newpp & HPTE_R_PP0) >> 55;
 383
 384         lpar_rc = plpar_pte_protect(flags, slot, 0);
 385
 386         BUG_ON(lpar_rc != H_SUCCESS);
 387 }
 388
 389 static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long vpn,
 390                                          int psize, int apsize,
 391                                          int ssize, int local)
 392 {
 393         unsigned long want_v;
 394         unsigned long lpar_rc;
 395         unsigned long dummy1, dummy2;
 396
 397         pr_devel("    inval : slot=%lx, vpn=%016lx, psize: %d, local: %d\n",
 398                  slot, vpn, psize, local);
 399
 400         want_v = hpte_encode_avpn(vpn, psize, ssize);
 401         lpar_rc = plpar_pte_remove(H_AVPN, slot, want_v, &dummy1, &dummy2);
 402         if (lpar_rc == H_NOT_FOUND)
 403                 return;
 404
 405         BUG_ON(lpar_rc != H_SUCCESS);
 406 }
 407
 408
 409 /*
 410  * As defined in the PAPR's section 14.5.4.1.8
 411  * The control mask doesn't include the returned reference and change bit from
 412  * the processed PTE.
 413  */
 414 #define HBLKR_AVPN              0x0100000000000000UL
 415 #define HBLKR_CTRL_MASK         0xf800000000000000UL
 416 #define HBLKR_CTRL_SUCCESS      0x8000000000000000UL
 417 #define HBLKR_CTRL_ERRNOTFOUND  0x8800000000000000UL
 418 #define HBLKR_CTRL_ERRBUSY      0xa000000000000000UL
 419
 420 /**
 421  * H_BLOCK_REMOVE caller.
 422  * @idx should point to the latest @param entry set with a PTEX.
 423  * If PTE cannot be processed because another CPUs has already locked that
 424  * group, those entries are put back in @param starting at index 1.
 425  * If entries has to be retried and @retry_busy is set to true, these entries
 426  * are retried until success. If @retry_busy is set to false, the returned
 427  * is the number of entries yet to process.
 428  */
 429 static unsigned long call_block_remove(unsigned long idx, unsigned long *param,
 430                                        bool retry_busy)
 431 {
 432         unsigned long i, rc, new_idx;
 433         unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
 434
 435         if (idx < 2) {
 436                 pr_warn("Unexpected empty call to H_BLOCK_REMOVE");
 437                 return 0;
 438         }
 439 again:
 440         new_idx = 0;
 441         if (idx > PLPAR_HCALL9_BUFSIZE) {
 442                 pr_err("Too many PTEs (%lu) for H_BLOCK_REMOVE", idx);
 443                 idx = PLPAR_HCALL9_BUFSIZE;
 444         } else if (idx < PLPAR_HCALL9_BUFSIZE)
 445                 param[idx] = HBR_END;
 446
 447         rc = plpar_hcall9(H_BLOCK_REMOVE, retbuf,
 448                           param[0], /* AVA */
 449                           param[1],  param[2],  param[3],  param[4], /* TS0-7 */
 450                           param[5],  param[6],  param[7],  param[8]);
 451         if (rc == H_SUCCESS)
 452                 return 0;
 453
 454         BUG_ON(rc != H_PARTIAL);
 455
 456         /* Check that the unprocessed entries were 'not found' or 'busy' */
 457         for (i = 0; i < idx-1; i++) {
 458                 unsigned long ctrl = retbuf[i] & HBLKR_CTRL_MASK;
 459
 460                 if (ctrl == HBLKR_CTRL_ERRBUSY) {
 461                         param[++new_idx] = param[i+1];
 462                         continue;
 463                 }
 464
 465                 BUG_ON(ctrl != HBLKR_CTRL_SUCCESS
 466                        && ctrl != HBLKR_CTRL_ERRNOTFOUND);
 467         }
 468
 469         /*
 470          * If there were entries found busy, retry these entries if requested,
 471          * of if all the entries have to be retried.
 472          */
 473         if (new_idx && (retry_busy || new_idx == (PLPAR_HCALL9_BUFSIZE-1))) {
 474                 idx = new_idx + 1;
 475                 goto again;
 476         }
 477
 478         return new_idx;
 479 }
 480
 481 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 482 /*
 483  * Limit iterations holding pSeries_lpar_tlbie_lock to 3. We also need
 484  * to make sure that we avoid bouncing the hypervisor tlbie lock.
 485  */
 486 #define PPC64_HUGE_HPTE_BATCH 12
 487
 488 static void hugepage_block_invalidate(unsigned long *slot, unsigned long *vpn,
 489                                       int count, int psize, int ssize)
 490 {
 491         unsigned long param[PLPAR_HCALL9_BUFSIZE];
 492         unsigned long shift, current_vpgb, vpgb;
 493         int i, pix = 0;
 494
 495         shift = mmu_psize_defs[psize].shift;
 496
 497         for (i = 0; i < count; i++) {
 498                 /*
 499                  * Shifting 3 bits more on the right to get a
 500                  * 8 pages aligned virtual addresse.
 501                  */
 502                 vpgb = (vpn[i] >> (shift - VPN_SHIFT + 3));
 503                 if (!pix || vpgb != current_vpgb) {
 504                         /*
 505                          * Need to start a new 8 pages block, flush
 506                          * the current one if needed.
 507                          */
 508                         if (pix)
 509                                 (void)call_block_remove(pix, param, true);
 510                         current_vpgb = vpgb;
 511                         param[0] = hpte_encode_avpn(vpn[i], psize, ssize);
 512                         pix = 1;
 513                 }
 514
 515                 param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot[i];
 516                 if (pix == PLPAR_HCALL9_BUFSIZE) {
 517                         pix = call_block_remove(pix, param, false);
 518                         /*
 519                          * pix = 0 means that all the entries were
 520                          * removed, we can start a new block.
 521                          * Otherwise, this means that there are entries
 522                          * to retry, and pix points to latest one, so
 523                          * we should increment it and try to continue
 524                          * the same block.
 525                          */
 526                         if (pix)
 527                                 pix++;
 528                 }
 529         }
 530         if (pix)
 531                 (void)call_block_remove(pix, param, true);
 532 }
 533
 534 static void hugepage_bulk_invalidate(unsigned long *slot, unsigned long *vpn,
 535                                      int count, int psize, int ssize)
 536 {
 537         unsigned long param[PLPAR_HCALL9_BUFSIZE];
 538         int i = 0, pix = 0, rc;
 539
 540         for (i = 0; i < count; i++) {
 541
 542                 if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
 543                         pSeries_lpar_hpte_invalidate(slot[i], vpn[i], psize, 0,
 544                                                      ssize, 0);
 545                 } else {
 546                         param[pix] = HBR_REQUEST | HBR_AVPN | slot[i];
 547                         param[pix+1] = hpte_encode_avpn(vpn[i], psize, ssize);
 548                         pix += 2;
 549                         if (pix == 8) {
 550                                 rc = plpar_hcall9(H_BULK_REMOVE, param,
 551                                                   param[0], param[1], param[2],
 552                                                   param[3], param[4], param[5],
 553                                                   param[6], param[7]);
 554                                 BUG_ON(rc != H_SUCCESS);
 555                                 pix = 0;
 556                         }
 557                 }
 558         }
 559         if (pix) {
 560                 param[pix] = HBR_END;
 561                 rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
 562                                   param[2], param[3], param[4], param[5],
 563                                   param[6], param[7]);
 564                 BUG_ON(rc != H_SUCCESS);
 565         }
 566 }
 567
 568 static inline void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
 569                                                       unsigned long *vpn,
 570                                                       int count, int psize,
 571                                                       int ssize)
 572 {
 573         unsigned long flags = 0;
 574         int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 575
 576         if (lock_tlbie)
 577                 spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
 578
 579         if (firmware_has_feature(FW_FEATURE_BLOCK_REMOVE))
 580                 hugepage_block_invalidate(slot, vpn, count, psize, ssize);
 581         else
 582                 hugepage_bulk_invalidate(slot, vpn, count, psize, ssize);
 583
 584         if (lock_tlbie)
 585                 spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
 586 }
 587
 588 static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
 589                                              unsigned long addr,
 590                                              unsigned char *hpte_slot_array,
 591                                              int psize, int ssize, int local)
 592 {
 593         int i, index = 0;
 594         unsigned long s_addr = addr;
 595         unsigned int max_hpte_count, valid;
 596         unsigned long vpn_array[PPC64_HUGE_HPTE_BATCH];
 597         unsigned long slot_array[PPC64_HUGE_HPTE_BATCH];
 598         unsigned long shift, hidx, vpn = 0, hash, slot;
 599
 600         shift = mmu_psize_defs[psize].shift;
 601         max_hpte_count = 1U << (PMD_SHIFT - shift);
 602
 603         for (i = 0; i < max_hpte_count; i++) {
 604                 valid = hpte_valid(hpte_slot_array, i);
 605                 if (!valid)
 606                         continue;
 607                 hidx =  hpte_hash_index(hpte_slot_array, i);
 608
 609                 /* get the vpn */
 610                 addr = s_addr + (i * (1ul << shift));
 611                 vpn = hpt_vpn(addr, vsid, ssize);
 612                 hash = hpt_hash(vpn, shift, ssize);
 613                 if (hidx & _PTEIDX_SECONDARY)
 614                         hash = ~hash;
 615
 616                 slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 617                 slot += hidx & _PTEIDX_GROUP_IX;
 618
 619                 slot_array[index] = slot;
 620                 vpn_array[index] = vpn;
 621                 if (index == PPC64_HUGE_HPTE_BATCH - 1) {
 622                         /*
 623                          * Now do a bluk invalidate
 624                          */
 625                         __pSeries_lpar_hugepage_invalidate(slot_array,
 626                                                            vpn_array,
 627                                                            PPC64_HUGE_HPTE_BATCH,
 628                                                            psize, ssize);
 629                         index = 0;
 630                 } else
 631                         index++;
 632         }
 633         if (index)
 634                 __pSeries_lpar_hugepage_invalidate(slot_array, vpn_array,
 635                                                    index, psize, ssize);
 636 }
 637 #else
 638 static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
 639                                              unsigned long addr,
 640                                              unsigned char *hpte_slot_array,
 641                                              int psize, int ssize, int local)
 642 {
 643         WARN(1, "%s called without THP support\n", __func__);
 644 }
 645 #endif
 646
 647 static int pSeries_lpar_hpte_removebolted(unsigned long ea,
 648                                           int psize, int ssize)
 649 {
 650         unsigned long vpn;
 651         unsigned long slot, vsid;
 652
 653         vsid = get_kernel_vsid(ea, ssize);
 654         vpn = hpt_vpn(ea, vsid, ssize);
 655
 656         slot = pSeries_lpar_hpte_find(vpn, psize, ssize);
 657         if (slot == -1)
 658                 return -ENOENT;
 659
 660         /*
 661          * lpar doesn't use the passed actual page size
 662          */
 663         pSeries_lpar_hpte_invalidate(slot, vpn, psize, 0, ssize, 0);
 664         return 0;
 665 }
 666
 667
 668 static inline unsigned long compute_slot(real_pte_t pte,
 669                                          unsigned long vpn,
 670                                          unsigned long index,
 671                                          unsigned long shift,
 672                                          int ssize)
 673 {
 674         unsigned long slot, hash, hidx;
 675
 676         hash = hpt_hash(vpn, shift, ssize);
 677         hidx = __rpte_to_hidx(pte, index);
 678         if (hidx & _PTEIDX_SECONDARY)
 679                 hash = ~hash;
 680         slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 681         slot += hidx & _PTEIDX_GROUP_IX;
 682         return slot;
 683 }
 684
 685 /**
 686  * The hcall H_BLOCK_REMOVE implies that the virtual pages to processed are
 687  * "all within the same naturally aligned 8 page virtual address block".
 688  */
 689 static void do_block_remove(unsigned long number, struct ppc64_tlb_batch *batch,
 690                             unsigned long *param)
 691 {
 692         unsigned long vpn;
 693         unsigned long i, pix = 0;
 694         unsigned long index, shift, slot, current_vpgb, vpgb;
 695         real_pte_t pte;
 696         int psize, ssize;
 697
 698         psize = batch->psize;
 699         ssize = batch->ssize;
 700
 701         for (i = 0; i < number; i++) {
 702                 vpn = batch->vpn[i];
 703                 pte = batch->pte[i];
 704                 pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
 705                         /*
 706                          * Shifting 3 bits more on the right to get a
 707                          * 8 pages aligned virtual addresse.
 708                          */
 709                         vpgb = (vpn >> (shift - VPN_SHIFT + 3));
 710                         if (!pix || vpgb != current_vpgb) {
 711                                 /*
 712                                  * Need to start a new 8 pages block, flush
 713                                  * the current one if needed.
 714                                  */
 715                                 if (pix)
 716                                         (void)call_block_remove(pix, param,
 717                                                                 true);
 718                                 current_vpgb = vpgb;
 719                                 param[0] = hpte_encode_avpn(vpn, psize,
 720                                                             ssize);
 721                                 pix = 1;
 722                         }
 723
 724                         slot = compute_slot(pte, vpn, index, shift, ssize);
 725                         param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot;
 726
 727                         if (pix == PLPAR_HCALL9_BUFSIZE) {
 728                                 pix = call_block_remove(pix, param, false);
 729                                 /*
 730                                  * pix = 0 means that all the entries were
 731                                  * removed, we can start a new block.
 732                                  * Otherwise, this means that there are entries
 733                                  * to retry, and pix points to latest one, so
 734                                  * we should increment it and try to continue
 735                                  * the same block.
 736                                  */
 737                                 if (pix)
 738                                         pix++;
 739                         }
 740                 } pte_iterate_hashed_end();
 741         }
 742
 743         if (pix)
 744                 (void)call_block_remove(pix, param, true);
 745 }
 746
 747 /*
 748  * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
 749  * lock.
 750  */
 751 static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
 752 {
 753         unsigned long vpn;
 754         unsigned long i, pix, rc;
 755         unsigned long flags = 0;
 756         struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 757         int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 758         unsigned long param[PLPAR_HCALL9_BUFSIZE];
 759         unsigned long index, shift, slot;
 760         real_pte_t pte;
 761         int psize, ssize;
 762
 763         if (lock_tlbie)
 764                 spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
 765
 766         if (firmware_has_feature(FW_FEATURE_BLOCK_REMOVE)) {
 767                 do_block_remove(number, batch, param);
 768                 goto out;
 769         }
 770
 771         psize = batch->psize;
 772         ssize = batch->ssize;
 773         pix = 0;
 774         for (i = 0; i < number; i++) {
 775                 vpn = batch->vpn[i];
 776                 pte = batch->pte[i];
 777                 pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
 778                         slot = compute_slot(pte, vpn, index, shift, ssize);
 779                         if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
 780                                 /*
 781                                  * lpar doesn't use the passed actual page size
 782                                  */
 783                                 pSeries_lpar_hpte_invalidate(slot, vpn, psize,
 784                                                              0, ssize, local);
 785                         } else {
 786                                 param[pix] = HBR_REQUEST | HBR_AVPN | slot;
 787                                 param[pix+1] = hpte_encode_avpn(vpn, psize,
 788                                                                 ssize);
 789                                 pix += 2;
 790                                 if (pix == 8) {
 791                                         rc = plpar_hcall9(H_BULK_REMOVE, param,
 792                                                 param[0], param[1], param[2],
 793                                                 param[3], param[4], param[5],
 794                                                 param[6], param[7]);
 795                                         BUG_ON(rc != H_SUCCESS);
 796                                         pix = 0;
 797                                 }
 798                         }
 799                 } pte_iterate_hashed_end();
 800         }
 801         if (pix) {
 802                 param[pix] = HBR_END;
 803                 rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
 804                                   param[2], param[3], param[4], param[5],
 805                                   param[6], param[7]);
 806                 BUG_ON(rc != H_SUCCESS);
 807         }
 808
 809 out:
 810         if (lock_tlbie)
 811                 spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
 812 }
 813
 814 static int __init disable_bulk_remove(char *str)
 815 {
 816         if (strcmp(str, "off") == 0 &&
 817             firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
 818                 pr_info("Disabling BULK_REMOVE firmware feature");
 819                 powerpc_firmware_features &= ~FW_FEATURE_BULK_REMOVE;
 820         }
 821         return 1;
 822 }
 823
 824 __setup("bulk_remove=", disable_bulk_remove);
 825
 826 #define HPT_RESIZE_TIMEOUT      10000 /* ms */
 827
 828 struct hpt_resize_state {
 829         unsigned long shift;
 830         int commit_rc;
 831 };
 832
 833 static int pseries_lpar_resize_hpt_commit(void *data)
 834 {
 835         struct hpt_resize_state *state = data;
 836
 837         state->commit_rc = plpar_resize_hpt_commit(0, state->shift);
 838         if (state->commit_rc != H_SUCCESS)
 839                 return -EIO;
 840
 841         /* Hypervisor has transitioned the HTAB, update our globals */
 842         ppc64_pft_size = state->shift;
 843         htab_size_bytes = 1UL << ppc64_pft_size;
 844         htab_hash_mask = (htab_size_bytes >> 7) - 1;
 845
 846         return 0;
 847 }
 848
 849 /* Must be called in user context */
 850 static int pseries_lpar_resize_hpt(unsigned long shift)
 851 {
 852         struct hpt_resize_state state = {
 853                 .shift = shift,
 854                 .commit_rc = H_FUNCTION,
 855         };
 856         unsigned int delay, total_delay = 0;
 857         int rc;
 858         ktime_t t0, t1, t2;
 859
 860         might_sleep();
 861
 862         if (!firmware_has_feature(FW_FEATURE_HPT_RESIZE))
 863                 return -ENODEV;
 864
 865         pr_info("Attempting to resize HPT to shift %lu\n", shift);
 866
 867         t0 = ktime_get();
 868
 869         rc = plpar_resize_hpt_prepare(0, shift);
 870         while (H_IS_LONG_BUSY(rc)) {
 871                 delay = get_longbusy_msecs(rc);
 872                 total_delay += delay;
 873                 if (total_delay > HPT_RESIZE_TIMEOUT) {
 874                         /* prepare with shift==0 cancels an in-progress resize */
 875                         rc = plpar_resize_hpt_prepare(0, 0);
 876                         if (rc != H_SUCCESS)
 877                                 pr_warn("Unexpected error %d cancelling timed out HPT resize\n",
 878                                        rc);
 879                         return -ETIMEDOUT;
 880                 }
 881                 msleep(delay);
 882                 rc = plpar_resize_hpt_prepare(0, shift);
 883         };
 884
 885         switch (rc) {
 886         case H_SUCCESS:
 887                 /* Continue on */
 888                 break;
 889
 890         case H_PARAMETER:
 891                 pr_warn("Invalid argument from H_RESIZE_HPT_PREPARE\n");
 892                 return -EINVAL;
 893         case H_RESOURCE:
 894                 pr_warn("Operation not permitted from H_RESIZE_HPT_PREPARE\n");
 895                 return -EPERM;
 896         default:
 897                 pr_warn("Unexpected error %d from H_RESIZE_HPT_PREPARE\n", rc);
 898                 return -EIO;
 899         }
 900
 901         t1 = ktime_get();
 902
 903         rc = stop_machine(pseries_lpar_resize_hpt_commit, &state, NULL);
 904
 905         t2 = ktime_get();
 906
 907         if (rc != 0) {
 908                 switch (state.commit_rc) {
 909                 case H_PTEG_FULL:
 910                         return -ENOSPC;
 911
 912                 default:
 913                         pr_warn("Unexpected error %d from H_RESIZE_HPT_COMMIT\n",
 914                                 state.commit_rc);
 915                         return -EIO;
 916                 };
 917         }
 918
 919         pr_info("HPT resize to shift %lu complete (%lld ms / %lld ms)\n",
 920                 shift, (long long) ktime_ms_delta(t1, t0),
 921                 (long long) ktime_ms_delta(t2, t1));
 922
 923         return 0;
 924 }
 925
 926 static int pseries_lpar_register_process_table(unsigned long base,
 927                         unsigned long page_size, unsigned long table_size)
 928 {
 929         long rc;
 930         unsigned long flags = 0;
 931
 932         if (table_size)
 933                 flags |= PROC_TABLE_NEW;
 934         if (radix_enabled())
 935                 flags |= PROC_TABLE_RADIX | PROC_TABLE_GTSE;
 936         else
 937                 flags |= PROC_TABLE_HPT_SLB;
 938         for (;;) {
 939                 rc = plpar_hcall_norets(H_REGISTER_PROC_TBL, flags, base,
 940                                         page_size, table_size);
 941                 if (!H_IS_LONG_BUSY(rc))
 942                         break;
 943                 mdelay(get_longbusy_msecs(rc));
 944         }
 945         if (rc != H_SUCCESS) {
 946                 pr_err("Failed to register process table (rc=%ld)\n", rc);
 947                 BUG();
 948         }
 949         return rc;
 950 }
 951
 952 void __init hpte_init_pseries(void)
 953 {
 954         mmu_hash_ops.hpte_invalidate     = pSeries_lpar_hpte_invalidate;
 955         mmu_hash_ops.hpte_updatepp       = pSeries_lpar_hpte_updatepp;
 956         mmu_hash_ops.hpte_updateboltedpp = pSeries_lpar_hpte_updateboltedpp;
 957         mmu_hash_ops.hpte_insert         = pSeries_lpar_hpte_insert;
 958         mmu_hash_ops.hpte_remove         = pSeries_lpar_hpte_remove;
 959         mmu_hash_ops.hpte_removebolted   = pSeries_lpar_hpte_removebolted;
 960         mmu_hash_ops.flush_hash_range    = pSeries_lpar_flush_hash_range;
 961         mmu_hash_ops.hpte_clear_all      = pseries_hpte_clear_all;
 962         mmu_hash_ops.hugepage_invalidate = pSeries_lpar_hugepage_invalidate;
 963         register_process_table           = pseries_lpar_register_process_table;
 964
 965         if (firmware_has_feature(FW_FEATURE_HPT_RESIZE))
 966                 mmu_hash_ops.resize_hpt = pseries_lpar_resize_hpt;
 967 }
 968
 969 void radix_init_pseries(void)
 970 {
 971         pr_info("Using radix MMU under hypervisor\n");
 972         register_process_table = pseries_lpar_register_process_table;
 973 }
 974
 975 #ifdef CONFIG_PPC_SMLPAR
 976 #define CMO_FREE_HINT_DEFAULT 1
 977 static int cmo_free_hint_flag = CMO_FREE_HINT_DEFAULT;
 978
 979 static int __init cmo_free_hint(char *str)
 980 {
 981         char *parm;
 982         parm = strstrip(str);
 983
 984         if (strcasecmp(parm, "no") == 0 || strcasecmp(parm, "off") == 0) {
 985                 pr_info("%s: CMO free page hinting is not active.\n", __func__);
 986                 cmo_free_hint_flag = 0;
 987                 return 1;
 988         }
 989
 990         cmo_free_hint_flag = 1;
 991         pr_info("%s: CMO free page hinting is active.\n", __func__);
 992
 993         if (strcasecmp(parm, "yes") == 0 || strcasecmp(parm, "on") == 0)
 994                 return 1;
 995
 996         return 0;
 997 }
 998
 999 __setup("cmo_free_hint=", cmo_free_hint);
1000
1001 static void pSeries_set_page_state(struct page *page, int order,
1002                                    unsigned long state)
1003 {
1004         int i, j;
1005         unsigned long cmo_page_sz, addr;
1006
1007         cmo_page_sz = cmo_get_page_size();
1008         addr = __pa((unsigned long)page_address(page));
1009
1010         for (i = 0; i < (1 << order); i++, addr += PAGE_SIZE) {
1011                 for (j = 0; j < PAGE_SIZE; j += cmo_page_sz)
1012                         plpar_hcall_norets(H_PAGE_INIT, state, addr + j, 0);
1013         }
1014 }
1015
1016 void arch_free_page(struct page *page, int order)
1017 {
1018         if (radix_enabled())
1019                 return;
1020         if (!cmo_free_hint_flag || !firmware_has_feature(FW_FEATURE_CMO))
1021                 return;
1022
1023         pSeries_set_page_state(page, order, H_PAGE_SET_UNUSED);
1024 }
1025 EXPORT_SYMBOL(arch_free_page);
1026
1027 #endif /* CONFIG_PPC_SMLPAR */
1028 #endif /* CONFIG_PPC_BOOK3S_64 */
1029
1030 #ifdef CONFIG_TRACEPOINTS
1031 #ifdef CONFIG_JUMP_LABEL
1032 struct static_key hcall_tracepoint_key = STATIC_KEY_INIT;
1033
1034 int hcall_tracepoint_regfunc(void)
1035 {
1036         static_key_slow_inc(&hcall_tracepoint_key);
1037         return 0;
1038 }
1039
1040 void hcall_tracepoint_unregfunc(void)
1041 {
1042         static_key_slow_dec(&hcall_tracepoint_key);
1043 }
1044 #else
1045 /*
1046  * We optimise our hcall path by placing hcall_tracepoint_refcount
1047  * directly in the TOC so we can check if the hcall tracepoints are
1048  * enabled via a single load.
1049  */
1050
1051 /* NB: reg/unreg are called while guarded with the tracepoints_mutex */
1052 extern long hcall_tracepoint_refcount;
1053
1054 int hcall_tracepoint_regfunc(void)
1055 {
1056         hcall_tracepoint_refcount++;
1057         return 0;
1058 }
1059
1060 void hcall_tracepoint_unregfunc(void)
1061 {
1062         hcall_tracepoint_refcount--;
1063 }
1064 #endif
1065
1066 /*
1067  * Since the tracing code might execute hcalls we need to guard against
1068  * recursion. One example of this are spinlocks calling H_YIELD on
1069  * shared processor partitions.
1070  */
1071 static DEFINE_PER_CPU(unsigned int, hcall_trace_depth);
1072
1073
1074 void __trace_hcall_entry(unsigned long opcode, unsigned long *args)
1075 {
1076         unsigned long flags;
1077         unsigned int *depth;
1078
1079         /*
1080          * We cannot call tracepoints inside RCU idle regions which
1081          * means we must not trace H_CEDE.
1082          */
1083         if (opcode == H_CEDE)
1084                 return;
1085
1086         local_irq_save(flags);
1087
1088         depth = this_cpu_ptr(&hcall_trace_depth);
1089
1090         if (*depth)
1091                 goto out;
1092
1093         (*depth)++;
1094         preempt_disable();
1095         trace_hcall_entry(opcode, args);
1096         (*depth)--;
1097
1098 out:
1099         local_irq_restore(flags);
1100 }
1101
1102 void __trace_hcall_exit(long opcode, long retval, unsigned long *retbuf)
1103 {
1104         unsigned long flags;
1105         unsigned int *depth;
1106
1107         if (opcode == H_CEDE)
1108                 return;
1109
1110         local_irq_save(flags);
1111
1112         depth = this_cpu_ptr(&hcall_trace_depth);
1113
1114         if (*depth)
1115                 goto out;
1116
1117         (*depth)++;
1118         trace_hcall_exit(opcode, retval, retbuf);
1119         preempt_enable();
1120         (*depth)--;
1121
1122 out:
1123         local_irq_restore(flags);
1124 }
1125 #endif
1126
1127 /**
1128  * h_get_mpp
1129  * H_GET_MPP hcall returns info in 7 parms
1130  */
1131 int h_get_mpp(struct hvcall_mpp_data *mpp_data)
1132 {
1133         int rc;
1134         unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
1135
1136         rc = plpar_hcall9(H_GET_MPP, retbuf);
1137
1138         mpp_data->entitled_mem = retbuf[0];
1139         mpp_data->mapped_mem = retbuf[1];
1140
1141         mpp_data->group_num = (retbuf[2] >> 2 * 8) & 0xffff;
1142         mpp_data->pool_num = retbuf[2] & 0xffff;
1143
1144         mpp_data->mem_weight = (retbuf[3] >> 7 * 8) & 0xff;
1145         mpp_data->unallocated_mem_weight = (retbuf[3] >> 6 * 8) & 0xff;
1146         mpp_data->unallocated_entitlement = retbuf[3] & 0xffffffffffffUL;
1147
1148         mpp_data->pool_size = retbuf[4];
1149         mpp_data->loan_request = retbuf[5];
1150         mpp_data->backing_mem = retbuf[6];
1151
1152         return rc;
1153 }
1154 EXPORT_SYMBOL(h_get_mpp);
1155
1156 int h_get_mpp_x(struct hvcall_mpp_x_data *mpp_x_data)
1157 {
1158         int rc;
1159         unsigned long retbuf[PLPAR_HCALL9_BUFSIZE] = { 0 };
1160
1161         rc = plpar_hcall9(H_GET_MPP_X, retbuf);
1162
1163         mpp_x_data->coalesced_bytes = retbuf[0];
1164         mpp_x_data->pool_coalesced_bytes = retbuf[1];
1165         mpp_x_data->pool_purr_cycles = retbuf[2];
1166         mpp_x_data->pool_spurr_cycles = retbuf[3];
1167
1168         return rc;
1169 }
1170
1171 static unsigned long vsid_unscramble(unsigned long vsid, int ssize)
1172 {
1173         unsigned long protovsid;
1174         unsigned long va_bits = VA_BITS;
1175         unsigned long modinv, vsid_modulus;
1176         unsigned long max_mod_inv, tmp_modinv;
1177
1178         if (!mmu_has_feature(MMU_FTR_68_BIT_VA))
1179                 va_bits = 65;
1180
1181         if (ssize == MMU_SEGSIZE_256M) {
1182                 modinv = VSID_MULINV_256M;
1183                 vsid_modulus = ((1UL << (va_bits - SID_SHIFT)) - 1);
1184         } else {
1185                 modinv = VSID_MULINV_1T;
1186                 vsid_modulus = ((1UL << (va_bits - SID_SHIFT_1T)) - 1);
1187         }
1188
1189         /*
1190          * vsid outside our range.
1191          */
1192         if (vsid >= vsid_modulus)
1193                 return 0;
1194
1195         /*
1196          * If modinv is the modular multiplicate inverse of (x % vsid_modulus)
1197          * and vsid = (protovsid * x) % vsid_modulus, then we say:
1198          *   protovsid = (vsid * modinv) % vsid_modulus
1199          */
1200
1201         /* Check if (vsid * modinv) overflow (63 bits) */
1202         max_mod_inv = 0x7fffffffffffffffull / vsid;
1203         if (modinv < max_mod_inv)
1204                 return (vsid * modinv) % vsid_modulus;
1205
1206         tmp_modinv = modinv/max_mod_inv;
1207         modinv %= max_mod_inv;
1208
1209         protovsid = (((vsid * max_mod_inv) % vsid_modulus) * tmp_modinv) % vsid_modulus;
1210         protovsid = (protovsid + vsid * modinv) % vsid_modulus;
1211
1212         return protovsid;
1213 }
1214
1215 static int __init reserve_vrma_context_id(void)
1216 {
1217         unsigned long protovsid;
1218
1219         /*
1220          * Reserve context ids which map to reserved virtual addresses. For now
1221          * we only reserve the context id which maps to the VRMA VSID. We ignore
1222          * the addresses in "ibm,adjunct-virtual-addresses" because we don't
1223          * enable adjunct support via the "ibm,client-architecture-support"
1224          * interface.
1225          */
1226         protovsid = vsid_unscramble(VRMA_VSID, MMU_SEGSIZE_1T);
1227         hash__reserve_context_id(protovsid >> ESID_BITS_1T);
1228         return 0;
1229 }
1230 machine_device_initcall(pseries, reserve_vrma_context_id);
1231
1232 #ifdef CONFIG_DEBUG_FS
1233 /* debugfs file interface for vpa data */
1234 static ssize_t vpa_file_read(struct file *filp, char __user *buf, size_t len,
1235                               loff_t *pos)
1236 {
1237         int cpu = (long)filp->private_data;
1238         struct lppaca *lppaca = &lppaca_of(cpu);
1239
1240         return simple_read_from_buffer(buf, len, pos, lppaca,
1241                                 sizeof(struct lppaca));
1242 }
1243
1244 static const struct file_operations vpa_fops = {
1245         .open           = simple_open,
1246         .read           = vpa_file_read,
1247         .llseek         = default_llseek,
1248 };
1249
1250 static int __init vpa_debugfs_init(void)
1251 {
1252         char name[16];
1253         long i;
1254         static struct dentry *vpa_dir;
1255
1256         if (!firmware_has_feature(FW_FEATURE_SPLPAR))
1257                 return 0;
1258
1259         vpa_dir = debugfs_create_dir("vpa", powerpc_debugfs_root);
1260         if (!vpa_dir) {
1261                 pr_warn("%s: can't create vpa root dir\n", __func__);
1262                 return -ENOMEM;
1263         }
1264
1265         /* set up the per-cpu vpa file*/
1266         for_each_possible_cpu(i) {
1267                 struct dentry *d;
1268
1269                 sprintf(name, "cpu-%ld", i);
1270
1271                 d = debugfs_create_file(name, 0400, vpa_dir, (void *)i,
1272                                         &vpa_fops);
1273                 if (!d) {
1274                         pr_warn("%s: can't create per-cpu vpa file\n",
1275                                         __func__);
1276                         return -ENOMEM;
1277                 }
1278         }
1279
1280         return 0;
1281 }
1282 machine_arch_initcall(pseries, vpa_debugfs_init);
1283 #endif /* CONFIG_DEBUG_FS */