arch/powerpc/platforms/pseries/lpar.c

   1 /*
   2  * pSeries_lpar.c
   3  * Copyright (C) 2001 Todd Inglett, IBM Corporation
   4  *
   5  * pSeries LPAR support.
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  20  */
  21
  22 /* Enables debugging of low-level hash table routines - careful! */
  23 #undef DEBUG
  24 #define pr_fmt(fmt) "lpar: " fmt
  25
  26 #include <linux/kernel.h>
  27 #include <linux/dma-mapping.h>
  28 #include <linux/console.h>
  29 #include <linux/export.h>
  30 #include <linux/jump_label.h>
  31 #include <linux/delay.h>
  32 #include <linux/stop_machine.h>
  33 #include <asm/processor.h>
  34 #include <asm/mmu.h>
  35 #include <asm/page.h>
  36 #include <asm/pgtable.h>
  37 #include <asm/machdep.h>
  38 #include <asm/mmu_context.h>
  39 #include <asm/iommu.h>
  40 #include <asm/tlb.h>
  41 #include <asm/prom.h>
  42 #include <asm/cputable.h>
  43 #include <asm/udbg.h>
  44 #include <asm/smp.h>
  45 #include <asm/trace.h>
  46 #include <asm/firmware.h>
  47 #include <asm/plpar_wrappers.h>
  48 #include <asm/kexec.h>
  49 #include <asm/fadump.h>
  50 #include <asm/asm-prototypes.h>
  51 #include <asm/debugfs.h>
  52
  53 #include "pseries.h"
  54
  55 /* Flag bits for H_BULK_REMOVE */
  56 #define HBR_REQUEST     0x4000000000000000UL
  57 #define HBR_RESPONSE    0x8000000000000000UL
  58 #define HBR_END         0xc000000000000000UL
  59 #define HBR_AVPN        0x0200000000000000UL
  60 #define HBR_ANDCOND     0x0100000000000000UL
  61
  62
  63 /* in hvCall.S */
  64 EXPORT_SYMBOL(plpar_hcall);
  65 EXPORT_SYMBOL(plpar_hcall9);
  66 EXPORT_SYMBOL(plpar_hcall_norets);
  67
  68 void vpa_init(int cpu)
  69 {
  70         int hwcpu = get_hard_smp_processor_id(cpu);
  71         unsigned long addr;
  72         long ret;
  73         struct paca_struct *pp;
  74         struct dtl_entry *dtl;
  75
  76         /*
  77          * The spec says it "may be problematic" if CPU x registers the VPA of
  78          * CPU y. We should never do that, but wail if we ever do.
  79          */
  80         WARN_ON(cpu != smp_processor_id());
  81
  82         if (cpu_has_feature(CPU_FTR_ALTIVEC))
  83                 lppaca_of(cpu).vmxregs_in_use = 1;
  84
  85         if (cpu_has_feature(CPU_FTR_ARCH_207S))
  86                 lppaca_of(cpu).ebb_regs_in_use = 1;
  87
  88         addr = __pa(&lppaca_of(cpu));
  89         ret = register_vpa(hwcpu, addr);
  90
  91         if (ret) {
  92                 pr_err("WARNING: VPA registration for cpu %d (hw %d) of area "
  93                        "%lx failed with %ld\n", cpu, hwcpu, addr, ret);
  94                 return;
  95         }
  96
  97 #ifdef CONFIG_PPC_BOOK3S_64
  98         /*
  99          * PAPR says this feature is SLB-Buffer but firmware never
 100          * reports that.  All SPLPAR support SLB shadow buffer.
 101          */
 102         if (!radix_enabled() && firmware_has_feature(FW_FEATURE_SPLPAR)) {
 103                 addr = __pa(paca_ptrs[cpu]->slb_shadow_ptr);
 104                 ret = register_slb_shadow(hwcpu, addr);
 105                 if (ret)
 106                         pr_err("WARNING: SLB shadow buffer registration for "
 107                                "cpu %d (hw %d) of area %lx failed with %ld\n",
 108                                cpu, hwcpu, addr, ret);
 109         }
 110 #endif /* CONFIG_PPC_BOOK3S_64 */
 111
 112         /*
 113          * Register dispatch trace log, if one has been allocated.
 114          */
 115         pp = paca_ptrs[cpu];
 116         dtl = pp->dispatch_log;
 117         if (dtl) {
 118                 pp->dtl_ridx = 0;
 119                 pp->dtl_curr = dtl;
 120                 lppaca_of(cpu).dtl_idx = 0;
 121
 122                 /* hypervisor reads buffer length from this field */
 123                 dtl->enqueue_to_dispatch_time = cpu_to_be32(DISPATCH_LOG_BYTES);
 124                 ret = register_dtl(hwcpu, __pa(dtl));
 125                 if (ret)
 126                         pr_err("WARNING: DTL registration of cpu %d (hw %d) "
 127                                "failed with %ld\n", smp_processor_id(),
 128                                hwcpu, ret);
 129                 lppaca_of(cpu).dtl_enable_mask = 2;
 130         }
 131 }
 132
 133 #ifdef CONFIG_PPC_BOOK3S_64
 134
 135 static long pSeries_lpar_hpte_insert(unsigned long hpte_group,
 136                                      unsigned long vpn, unsigned long pa,
 137                                      unsigned long rflags, unsigned long vflags,
 138                                      int psize, int apsize, int ssize)
 139 {
 140         unsigned long lpar_rc;
 141         unsigned long flags;
 142         unsigned long slot;
 143         unsigned long hpte_v, hpte_r;
 144
 145         if (!(vflags & HPTE_V_BOLTED))
 146                 pr_devel("hpte_insert(group=%lx, vpn=%016lx, "
 147                          "pa=%016lx, rflags=%lx, vflags=%lx, psize=%d)\n",
 148                          hpte_group, vpn,  pa, rflags, vflags, psize);
 149
 150         hpte_v = hpte_encode_v(vpn, psize, apsize, ssize) | vflags | HPTE_V_VALID;
 151         hpte_r = hpte_encode_r(pa, psize, apsize) | rflags;
 152
 153         if (!(vflags & HPTE_V_BOLTED))
 154                 pr_devel(" hpte_v=%016lx, hpte_r=%016lx\n", hpte_v, hpte_r);
 155
 156         /* Now fill in the actual HPTE */
 157         /* Set CEC cookie to 0         */
 158         /* Zero page = 0               */
 159         /* I-cache Invalidate = 0      */
 160         /* I-cache synchronize = 0     */
 161         /* Exact = 0                   */
 162         flags = 0;
 163
 164         if (firmware_has_feature(FW_FEATURE_XCMO) && !(hpte_r & HPTE_R_N))
 165                 flags |= H_COALESCE_CAND;
 166
 167         lpar_rc = plpar_pte_enter(flags, hpte_group, hpte_v, hpte_r, &slot);
 168         if (unlikely(lpar_rc == H_PTEG_FULL)) {
 169                 pr_devel("Hash table group is full\n");
 170                 return -1;
 171         }
 172
 173         /*
 174          * Since we try and ioremap PHBs we don't own, the pte insert
 175          * will fail. However we must catch the failure in hash_page
 176          * or we will loop forever, so return -2 in this case.
 177          */
 178         if (unlikely(lpar_rc != H_SUCCESS)) {
 179                 pr_err("Failed hash pte insert with error %ld\n", lpar_rc);
 180                 return -2;
 181         }
 182         if (!(vflags & HPTE_V_BOLTED))
 183                 pr_devel(" -> slot: %lu\n", slot & 7);
 184
 185         /* Because of iSeries, we have to pass down the secondary
 186          * bucket bit here as well
 187          */
 188         return (slot & 7) | (!!(vflags & HPTE_V_SECONDARY) << 3);
 189 }
 190
 191 static DEFINE_SPINLOCK(pSeries_lpar_tlbie_lock);
 192
 193 static long pSeries_lpar_hpte_remove(unsigned long hpte_group)
 194 {
 195         unsigned long slot_offset;
 196         unsigned long lpar_rc;
 197         int i;
 198         unsigned long dummy1, dummy2;
 199
 200         /* pick a random slot to start at */
 201         slot_offset = mftb() & 0x7;
 202
 203         for (i = 0; i < HPTES_PER_GROUP; i++) {
 204
 205                 /* don't remove a bolted entry */
 206                 lpar_rc = plpar_pte_remove(H_ANDCOND, hpte_group + slot_offset,
 207                                            (0x1UL << 4), &dummy1, &dummy2);
 208                 if (lpar_rc == H_SUCCESS)
 209                         return i;
 210
 211                 /*
 212                  * The test for adjunct partition is performed before the
 213                  * ANDCOND test.  H_RESOURCE may be returned, so we need to
 214                  * check for that as well.
 215                  */
 216                 BUG_ON(lpar_rc != H_NOT_FOUND && lpar_rc != H_RESOURCE);
 217
 218                 slot_offset++;
 219                 slot_offset &= 0x7;
 220         }
 221
 222         return -1;
 223 }
 224
 225 static void manual_hpte_clear_all(void)
 226 {
 227         unsigned long size_bytes = 1UL << ppc64_pft_size;
 228         unsigned long hpte_count = size_bytes >> 4;
 229         struct {
 230                 unsigned long pteh;
 231                 unsigned long ptel;
 232         } ptes[4];
 233         long lpar_rc;
 234         unsigned long i, j;
 235
 236         /* Read in batches of 4,
 237          * invalidate only valid entries not in the VRMA
 238          * hpte_count will be a multiple of 4
 239          */
 240         for (i = 0; i < hpte_count; i += 4) {
 241                 lpar_rc = plpar_pte_read_4_raw(0, i, (void *)ptes);
 242                 if (lpar_rc != H_SUCCESS) {
 243                         pr_info("Failed to read hash page table at %ld err %ld\n",
 244                                 i, lpar_rc);
 245                         continue;
 246                 }
 247                 for (j = 0; j < 4; j++){
 248                         if ((ptes[j].pteh & HPTE_V_VRMA_MASK) ==
 249                                 HPTE_V_VRMA_MASK)
 250                                 continue;
 251                         if (ptes[j].pteh & HPTE_V_VALID)
 252                                 plpar_pte_remove_raw(0, i + j, 0,
 253                                         &(ptes[j].pteh), &(ptes[j].ptel));
 254                 }
 255         }
 256 }
 257
 258 static int hcall_hpte_clear_all(void)
 259 {
 260         int rc;
 261
 262         do {
 263                 rc = plpar_hcall_norets(H_CLEAR_HPT);
 264         } while (rc == H_CONTINUE);
 265
 266         return rc;
 267 }
 268
 269 static void pseries_hpte_clear_all(void)
 270 {
 271         int rc;
 272
 273         rc = hcall_hpte_clear_all();
 274         if (rc != H_SUCCESS)
 275                 manual_hpte_clear_all();
 276
 277 #ifdef __LITTLE_ENDIAN__
 278         /*
 279          * Reset exceptions to big endian.
 280          *
 281          * FIXME this is a hack for kexec, we need to reset the exception
 282          * endian before starting the new kernel and this is a convenient place
 283          * to do it.
 284          *
 285          * This is also called on boot when a fadump happens. In that case we
 286          * must not change the exception endian mode.
 287          */
 288         if (firmware_has_feature(FW_FEATURE_SET_MODE) && !is_fadump_active())
 289                 pseries_big_endian_exceptions();
 290 #endif
 291 }
 292
 293 /*
 294  * NOTE: for updatepp ops we are fortunate that the linux "newpp" bits and
 295  * the low 3 bits of flags happen to line up.  So no transform is needed.
 296  * We can probably optimize here and assume the high bits of newpp are
 297  * already zero.  For now I am paranoid.
 298  */
 299 static long pSeries_lpar_hpte_updatepp(unsigned long slot,
 300                                        unsigned long newpp,
 301                                        unsigned long vpn,
 302                                        int psize, int apsize,
 303                                        int ssize, unsigned long inv_flags)
 304 {
 305         unsigned long lpar_rc;
 306         unsigned long flags;
 307         unsigned long want_v;
 308
 309         want_v = hpte_encode_avpn(vpn, psize, ssize);
 310
 311         flags = (newpp & 7) | H_AVPN;
 312         if (mmu_has_feature(MMU_FTR_KERNEL_RO))
 313                 /* Move pp0 into bit 8 (IBM 55) */
 314                 flags |= (newpp & HPTE_R_PP0) >> 55;
 315
 316         pr_devel("    update: avpnv=%016lx, hash=%016lx, f=%lx, psize: %d ...",
 317                  want_v, slot, flags, psize);
 318
 319         lpar_rc = plpar_pte_protect(flags, slot, want_v);
 320
 321         if (lpar_rc == H_NOT_FOUND) {
 322                 pr_devel("not found !\n");
 323                 return -1;
 324         }
 325
 326         pr_devel("ok\n");
 327
 328         BUG_ON(lpar_rc != H_SUCCESS);
 329
 330         return 0;
 331 }
 332
 333 static long __pSeries_lpar_hpte_find(unsigned long want_v, unsigned long hpte_group)
 334 {
 335         long lpar_rc;
 336         unsigned long i, j;
 337         struct {
 338                 unsigned long pteh;
 339                 unsigned long ptel;
 340         } ptes[4];
 341
 342         for (i = 0; i < HPTES_PER_GROUP; i += 4, hpte_group += 4) {
 343
 344                 lpar_rc = plpar_pte_read_4(0, hpte_group, (void *)ptes);
 345                 if (lpar_rc != H_SUCCESS) {
 346                         pr_info("Failed to read hash page table at %ld err %ld\n",
 347                                 hpte_group, lpar_rc);
 348                         continue;
 349                 }
 350
 351                 for (j = 0; j < 4; j++) {
 352                         if (HPTE_V_COMPARE(ptes[j].pteh, want_v) &&
 353                             (ptes[j].pteh & HPTE_V_VALID))
 354                                 return i + j;
 355                 }
 356         }
 357
 358         return -1;
 359 }
 360
 361 static long pSeries_lpar_hpte_find(unsigned long vpn, int psize, int ssize)
 362 {
 363         long slot;
 364         unsigned long hash;
 365         unsigned long want_v;
 366         unsigned long hpte_group;
 367
 368         hash = hpt_hash(vpn, mmu_psize_defs[psize].shift, ssize);
 369         want_v = hpte_encode_avpn(vpn, psize, ssize);
 370
 371         /* Bolted entries are always in the primary group */
 372         hpte_group = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 373         slot = __pSeries_lpar_hpte_find(want_v, hpte_group);
 374         if (slot < 0)
 375                 return -1;
 376         return hpte_group + slot;
 377 }
 378
 379 static void pSeries_lpar_hpte_updateboltedpp(unsigned long newpp,
 380                                              unsigned long ea,
 381                                              int psize, int ssize)
 382 {
 383         unsigned long vpn;
 384         unsigned long lpar_rc, slot, vsid, flags;
 385
 386         vsid = get_kernel_vsid(ea, ssize);
 387         vpn = hpt_vpn(ea, vsid, ssize);
 388
 389         slot = pSeries_lpar_hpte_find(vpn, psize, ssize);
 390         BUG_ON(slot == -1);
 391
 392         flags = newpp & 7;
 393         if (mmu_has_feature(MMU_FTR_KERNEL_RO))
 394                 /* Move pp0 into bit 8 (IBM 55) */
 395                 flags |= (newpp & HPTE_R_PP0) >> 55;
 396
 397         lpar_rc = plpar_pte_protect(flags, slot, 0);
 398
 399         BUG_ON(lpar_rc != H_SUCCESS);
 400 }
 401
 402 static void pSeries_lpar_hpte_invalidate(unsigned long slot, unsigned long vpn,
 403                                          int psize, int apsize,
 404                                          int ssize, int local)
 405 {
 406         unsigned long want_v;
 407         unsigned long lpar_rc;
 408         unsigned long dummy1, dummy2;
 409
 410         pr_devel("    inval : slot=%lx, vpn=%016lx, psize: %d, local: %d\n",
 411                  slot, vpn, psize, local);
 412
 413         want_v = hpte_encode_avpn(vpn, psize, ssize);
 414         lpar_rc = plpar_pte_remove(H_AVPN, slot, want_v, &dummy1, &dummy2);
 415         if (lpar_rc == H_NOT_FOUND)
 416                 return;
 417
 418         BUG_ON(lpar_rc != H_SUCCESS);
 419 }
 420
 421
 422 /*
 423  * As defined in the PAPR's section 14.5.4.1.8
 424  * The control mask doesn't include the returned reference and change bit from
 425  * the processed PTE.
 426  */
 427 #define HBLKR_AVPN              0x0100000000000000UL
 428 #define HBLKR_CTRL_MASK         0xf800000000000000UL
 429 #define HBLKR_CTRL_SUCCESS      0x8000000000000000UL
 430 #define HBLKR_CTRL_ERRNOTFOUND  0x8800000000000000UL
 431 #define HBLKR_CTRL_ERRBUSY      0xa000000000000000UL
 432
 433 /**
 434  * H_BLOCK_REMOVE caller.
 435  * @idx should point to the latest @param entry set with a PTEX.
 436  * If PTE cannot be processed because another CPUs has already locked that
 437  * group, those entries are put back in @param starting at index 1.
 438  * If entries has to be retried and @retry_busy is set to true, these entries
 439  * are retried until success. If @retry_busy is set to false, the returned
 440  * is the number of entries yet to process.
 441  */
 442 static unsigned long call_block_remove(unsigned long idx, unsigned long *param,
 443                                        bool retry_busy)
 444 {
 445         unsigned long i, rc, new_idx;
 446         unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
 447
 448         if (idx < 2) {
 449                 pr_warn("Unexpected empty call to H_BLOCK_REMOVE");
 450                 return 0;
 451         }
 452 again:
 453         new_idx = 0;
 454         if (idx > PLPAR_HCALL9_BUFSIZE) {
 455                 pr_err("Too many PTEs (%lu) for H_BLOCK_REMOVE", idx);
 456                 idx = PLPAR_HCALL9_BUFSIZE;
 457         } else if (idx < PLPAR_HCALL9_BUFSIZE)
 458                 param[idx] = HBR_END;
 459
 460         rc = plpar_hcall9(H_BLOCK_REMOVE, retbuf,
 461                           param[0], /* AVA */
 462                           param[1],  param[2],  param[3],  param[4], /* TS0-7 */
 463                           param[5],  param[6],  param[7],  param[8]);
 464         if (rc == H_SUCCESS)
 465                 return 0;
 466
 467         BUG_ON(rc != H_PARTIAL);
 468
 469         /* Check that the unprocessed entries were 'not found' or 'busy' */
 470         for (i = 0; i < idx-1; i++) {
 471                 unsigned long ctrl = retbuf[i] & HBLKR_CTRL_MASK;
 472
 473                 if (ctrl == HBLKR_CTRL_ERRBUSY) {
 474                         param[++new_idx] = param[i+1];
 475                         continue;
 476                 }
 477
 478                 BUG_ON(ctrl != HBLKR_CTRL_SUCCESS
 479                        && ctrl != HBLKR_CTRL_ERRNOTFOUND);
 480         }
 481
 482         /*
 483          * If there were entries found busy, retry these entries if requested,
 484          * of if all the entries have to be retried.
 485          */
 486         if (new_idx && (retry_busy || new_idx == (PLPAR_HCALL9_BUFSIZE-1))) {
 487                 idx = new_idx + 1;
 488                 goto again;
 489         }
 490
 491         return new_idx;
 492 }
 493
 494 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 495 /*
 496  * Limit iterations holding pSeries_lpar_tlbie_lock to 3. We also need
 497  * to make sure that we avoid bouncing the hypervisor tlbie lock.
 498  */
 499 #define PPC64_HUGE_HPTE_BATCH 12
 500
 501 static void hugepage_block_invalidate(unsigned long *slot, unsigned long *vpn,
 502                                       int count, int psize, int ssize)
 503 {
 504         unsigned long param[PLPAR_HCALL9_BUFSIZE];
 505         unsigned long shift, current_vpgb, vpgb;
 506         int i, pix = 0;
 507
 508         shift = mmu_psize_defs[psize].shift;
 509
 510         for (i = 0; i < count; i++) {
 511                 /*
 512                  * Shifting 3 bits more on the right to get a
 513                  * 8 pages aligned virtual addresse.
 514                  */
 515                 vpgb = (vpn[i] >> (shift - VPN_SHIFT + 3));
 516                 if (!pix || vpgb != current_vpgb) {
 517                         /*
 518                          * Need to start a new 8 pages block, flush
 519                          * the current one if needed.
 520                          */
 521                         if (pix)
 522                                 (void)call_block_remove(pix, param, true);
 523                         current_vpgb = vpgb;
 524                         param[0] = hpte_encode_avpn(vpn[i], psize, ssize);
 525                         pix = 1;
 526                 }
 527
 528                 param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot[i];
 529                 if (pix == PLPAR_HCALL9_BUFSIZE) {
 530                         pix = call_block_remove(pix, param, false);
 531                         /*
 532                          * pix = 0 means that all the entries were
 533                          * removed, we can start a new block.
 534                          * Otherwise, this means that there are entries
 535                          * to retry, and pix points to latest one, so
 536                          * we should increment it and try to continue
 537                          * the same block.
 538                          */
 539                         if (pix)
 540                                 pix++;
 541                 }
 542         }
 543         if (pix)
 544                 (void)call_block_remove(pix, param, true);
 545 }
 546
 547 static void hugepage_bulk_invalidate(unsigned long *slot, unsigned long *vpn,
 548                                      int count, int psize, int ssize)
 549 {
 550         unsigned long param[PLPAR_HCALL9_BUFSIZE];
 551         int i = 0, pix = 0, rc;
 552
 553         for (i = 0; i < count; i++) {
 554
 555                 if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
 556                         pSeries_lpar_hpte_invalidate(slot[i], vpn[i], psize, 0,
 557                                                      ssize, 0);
 558                 } else {
 559                         param[pix] = HBR_REQUEST | HBR_AVPN | slot[i];
 560                         param[pix+1] = hpte_encode_avpn(vpn[i], psize, ssize);
 561                         pix += 2;
 562                         if (pix == 8) {
 563                                 rc = plpar_hcall9(H_BULK_REMOVE, param,
 564                                                   param[0], param[1], param[2],
 565                                                   param[3], param[4], param[5],
 566                                                   param[6], param[7]);
 567                                 BUG_ON(rc != H_SUCCESS);
 568                                 pix = 0;
 569                         }
 570                 }
 571         }
 572         if (pix) {
 573                 param[pix] = HBR_END;
 574                 rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
 575                                   param[2], param[3], param[4], param[5],
 576                                   param[6], param[7]);
 577                 BUG_ON(rc != H_SUCCESS);
 578         }
 579 }
 580
 581 static inline void __pSeries_lpar_hugepage_invalidate(unsigned long *slot,
 582                                                       unsigned long *vpn,
 583                                                       int count, int psize,
 584                                                       int ssize)
 585 {
 586         unsigned long flags = 0;
 587         int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 588
 589         if (lock_tlbie)
 590                 spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
 591
 592         if (firmware_has_feature(FW_FEATURE_BLOCK_REMOVE))
 593                 hugepage_block_invalidate(slot, vpn, count, psize, ssize);
 594         else
 595                 hugepage_bulk_invalidate(slot, vpn, count, psize, ssize);
 596
 597         if (lock_tlbie)
 598                 spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
 599 }
 600
 601 static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
 602                                              unsigned long addr,
 603                                              unsigned char *hpte_slot_array,
 604                                              int psize, int ssize, int local)
 605 {
 606         int i, index = 0;
 607         unsigned long s_addr = addr;
 608         unsigned int max_hpte_count, valid;
 609         unsigned long vpn_array[PPC64_HUGE_HPTE_BATCH];
 610         unsigned long slot_array[PPC64_HUGE_HPTE_BATCH];
 611         unsigned long shift, hidx, vpn = 0, hash, slot;
 612
 613         shift = mmu_psize_defs[psize].shift;
 614         max_hpte_count = 1U << (PMD_SHIFT - shift);
 615
 616         for (i = 0; i < max_hpte_count; i++) {
 617                 valid = hpte_valid(hpte_slot_array, i);
 618                 if (!valid)
 619                         continue;
 620                 hidx =  hpte_hash_index(hpte_slot_array, i);
 621
 622                 /* get the vpn */
 623                 addr = s_addr + (i * (1ul << shift));
 624                 vpn = hpt_vpn(addr, vsid, ssize);
 625                 hash = hpt_hash(vpn, shift, ssize);
 626                 if (hidx & _PTEIDX_SECONDARY)
 627                         hash = ~hash;
 628
 629                 slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 630                 slot += hidx & _PTEIDX_GROUP_IX;
 631
 632                 slot_array[index] = slot;
 633                 vpn_array[index] = vpn;
 634                 if (index == PPC64_HUGE_HPTE_BATCH - 1) {
 635                         /*
 636                          * Now do a bluk invalidate
 637                          */
 638                         __pSeries_lpar_hugepage_invalidate(slot_array,
 639                                                            vpn_array,
 640                                                            PPC64_HUGE_HPTE_BATCH,
 641                                                            psize, ssize);
 642                         index = 0;
 643                 } else
 644                         index++;
 645         }
 646         if (index)
 647                 __pSeries_lpar_hugepage_invalidate(slot_array, vpn_array,
 648                                                    index, psize, ssize);
 649 }
 650 #else
 651 static void pSeries_lpar_hugepage_invalidate(unsigned long vsid,
 652                                              unsigned long addr,
 653                                              unsigned char *hpte_slot_array,
 654                                              int psize, int ssize, int local)
 655 {
 656         WARN(1, "%s called without THP support\n", __func__);
 657 }
 658 #endif
 659
 660 static int pSeries_lpar_hpte_removebolted(unsigned long ea,
 661                                           int psize, int ssize)
 662 {
 663         unsigned long vpn;
 664         unsigned long slot, vsid;
 665
 666         vsid = get_kernel_vsid(ea, ssize);
 667         vpn = hpt_vpn(ea, vsid, ssize);
 668
 669         slot = pSeries_lpar_hpte_find(vpn, psize, ssize);
 670         if (slot == -1)
 671                 return -ENOENT;
 672
 673         /*
 674          * lpar doesn't use the passed actual page size
 675          */
 676         pSeries_lpar_hpte_invalidate(slot, vpn, psize, 0, ssize, 0);
 677         return 0;
 678 }
 679
 680
 681 static inline unsigned long compute_slot(real_pte_t pte,
 682                                          unsigned long vpn,
 683                                          unsigned long index,
 684                                          unsigned long shift,
 685                                          int ssize)
 686 {
 687         unsigned long slot, hash, hidx;
 688
 689         hash = hpt_hash(vpn, shift, ssize);
 690         hidx = __rpte_to_hidx(pte, index);
 691         if (hidx & _PTEIDX_SECONDARY)
 692                 hash = ~hash;
 693         slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
 694         slot += hidx & _PTEIDX_GROUP_IX;
 695         return slot;
 696 }
 697
 698 /**
 699  * The hcall H_BLOCK_REMOVE implies that the virtual pages to processed are
 700  * "all within the same naturally aligned 8 page virtual address block".
 701  */
 702 static void do_block_remove(unsigned long number, struct ppc64_tlb_batch *batch,
 703                             unsigned long *param)
 704 {
 705         unsigned long vpn;
 706         unsigned long i, pix = 0;
 707         unsigned long index, shift, slot, current_vpgb, vpgb;
 708         real_pte_t pte;
 709         int psize, ssize;
 710
 711         psize = batch->psize;
 712         ssize = batch->ssize;
 713
 714         for (i = 0; i < number; i++) {
 715                 vpn = batch->vpn[i];
 716                 pte = batch->pte[i];
 717                 pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
 718                         /*
 719                          * Shifting 3 bits more on the right to get a
 720                          * 8 pages aligned virtual addresse.
 721                          */
 722                         vpgb = (vpn >> (shift - VPN_SHIFT + 3));
 723                         if (!pix || vpgb != current_vpgb) {
 724                                 /*
 725                                  * Need to start a new 8 pages block, flush
 726                                  * the current one if needed.
 727                                  */
 728                                 if (pix)
 729                                         (void)call_block_remove(pix, param,
 730                                                                 true);
 731                                 current_vpgb = vpgb;
 732                                 param[0] = hpte_encode_avpn(vpn, psize,
 733                                                             ssize);
 734                                 pix = 1;
 735                         }
 736
 737                         slot = compute_slot(pte, vpn, index, shift, ssize);
 738                         param[pix++] = HBR_REQUEST | HBLKR_AVPN | slot;
 739
 740                         if (pix == PLPAR_HCALL9_BUFSIZE) {
 741                                 pix = call_block_remove(pix, param, false);
 742                                 /*
 743                                  * pix = 0 means that all the entries were
 744                                  * removed, we can start a new block.
 745                                  * Otherwise, this means that there are entries
 746                                  * to retry, and pix points to latest one, so
 747                                  * we should increment it and try to continue
 748                                  * the same block.
 749                                  */
 750                                 if (pix)
 751                                         pix++;
 752                         }
 753                 } pte_iterate_hashed_end();
 754         }
 755
 756         if (pix)
 757                 (void)call_block_remove(pix, param, true);
 758 }
 759
 760 /*
 761  * Take a spinlock around flushes to avoid bouncing the hypervisor tlbie
 762  * lock.
 763  */
 764 static void pSeries_lpar_flush_hash_range(unsigned long number, int local)
 765 {
 766         unsigned long vpn;
 767         unsigned long i, pix, rc;
 768         unsigned long flags = 0;
 769         struct ppc64_tlb_batch *batch = this_cpu_ptr(&ppc64_tlb_batch);
 770         int lock_tlbie = !mmu_has_feature(MMU_FTR_LOCKLESS_TLBIE);
 771         unsigned long param[PLPAR_HCALL9_BUFSIZE];
 772         unsigned long index, shift, slot;
 773         real_pte_t pte;
 774         int psize, ssize;
 775
 776         if (lock_tlbie)
 777                 spin_lock_irqsave(&pSeries_lpar_tlbie_lock, flags);
 778
 779         if (firmware_has_feature(FW_FEATURE_BLOCK_REMOVE)) {
 780                 do_block_remove(number, batch, param);
 781                 goto out;
 782         }
 783
 784         psize = batch->psize;
 785         ssize = batch->ssize;
 786         pix = 0;
 787         for (i = 0; i < number; i++) {
 788                 vpn = batch->vpn[i];
 789                 pte = batch->pte[i];
 790                 pte_iterate_hashed_subpages(pte, psize, vpn, index, shift) {
 791                         slot = compute_slot(pte, vpn, index, shift, ssize);
 792                         if (!firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
 793                                 /*
 794                                  * lpar doesn't use the passed actual page size
 795                                  */
 796                                 pSeries_lpar_hpte_invalidate(slot, vpn, psize,
 797                                                              0, ssize, local);
 798                         } else {
 799                                 param[pix] = HBR_REQUEST | HBR_AVPN | slot;
 800                                 param[pix+1] = hpte_encode_avpn(vpn, psize,
 801                                                                 ssize);
 802                                 pix += 2;
 803                                 if (pix == 8) {
 804                                         rc = plpar_hcall9(H_BULK_REMOVE, param,
 805                                                 param[0], param[1], param[2],
 806                                                 param[3], param[4], param[5],
 807                                                 param[6], param[7]);
 808                                         BUG_ON(rc != H_SUCCESS);
 809                                         pix = 0;
 810                                 }
 811                         }
 812                 } pte_iterate_hashed_end();
 813         }
 814         if (pix) {
 815                 param[pix] = HBR_END;
 816                 rc = plpar_hcall9(H_BULK_REMOVE, param, param[0], param[1],
 817                                   param[2], param[3], param[4], param[5],
 818                                   param[6], param[7]);
 819                 BUG_ON(rc != H_SUCCESS);
 820         }
 821
 822 out:
 823         if (lock_tlbie)
 824                 spin_unlock_irqrestore(&pSeries_lpar_tlbie_lock, flags);
 825 }
 826
 827 static int __init disable_bulk_remove(char *str)
 828 {
 829         if (strcmp(str, "off") == 0 &&
 830             firmware_has_feature(FW_FEATURE_BULK_REMOVE)) {
 831                 pr_info("Disabling BULK_REMOVE firmware feature");
 832                 powerpc_firmware_features &= ~FW_FEATURE_BULK_REMOVE;
 833         }
 834         return 1;
 835 }
 836
 837 __setup("bulk_remove=", disable_bulk_remove);
 838
 839 #define HPT_RESIZE_TIMEOUT      10000 /* ms */
 840
 841 struct hpt_resize_state {
 842         unsigned long shift;
 843         int commit_rc;
 844 };
 845
 846 static int pseries_lpar_resize_hpt_commit(void *data)
 847 {
 848         struct hpt_resize_state *state = data;
 849
 850         state->commit_rc = plpar_resize_hpt_commit(0, state->shift);
 851         if (state->commit_rc != H_SUCCESS)
 852                 return -EIO;
 853
 854         /* Hypervisor has transitioned the HTAB, update our globals */
 855         ppc64_pft_size = state->shift;
 856         htab_size_bytes = 1UL << ppc64_pft_size;
 857         htab_hash_mask = (htab_size_bytes >> 7) - 1;
 858
 859         return 0;
 860 }
 861
 862 /* Must be called in user context */
 863 static int pseries_lpar_resize_hpt(unsigned long shift)
 864 {
 865         struct hpt_resize_state state = {
 866                 .shift = shift,
 867                 .commit_rc = H_FUNCTION,
 868         };
 869         unsigned int delay, total_delay = 0;
 870         int rc;
 871         ktime_t t0, t1, t2;
 872
 873         might_sleep();
 874
 875         if (!firmware_has_feature(FW_FEATURE_HPT_RESIZE))
 876                 return -ENODEV;
 877
 878         pr_info("Attempting to resize HPT to shift %lu\n", shift);
 879
 880         t0 = ktime_get();
 881
 882         rc = plpar_resize_hpt_prepare(0, shift);
 883         while (H_IS_LONG_BUSY(rc)) {
 884                 delay = get_longbusy_msecs(rc);
 885                 total_delay += delay;
 886                 if (total_delay > HPT_RESIZE_TIMEOUT) {
 887                         /* prepare with shift==0 cancels an in-progress resize */
 888                         rc = plpar_resize_hpt_prepare(0, 0);
 889                         if (rc != H_SUCCESS)
 890                                 pr_warn("Unexpected error %d cancelling timed out HPT resize\n",
 891                                        rc);
 892                         return -ETIMEDOUT;
 893                 }
 894                 msleep(delay);
 895                 rc = plpar_resize_hpt_prepare(0, shift);
 896         };
 897
 898         switch (rc) {
 899         case H_SUCCESS:
 900                 /* Continue on */
 901                 break;
 902
 903         case H_PARAMETER:
 904                 pr_warn("Invalid argument from H_RESIZE_HPT_PREPARE\n");
 905                 return -EINVAL;
 906         case H_RESOURCE:
 907                 pr_warn("Operation not permitted from H_RESIZE_HPT_PREPARE\n");
 908                 return -EPERM;
 909         default:
 910                 pr_warn("Unexpected error %d from H_RESIZE_HPT_PREPARE\n", rc);
 911                 return -EIO;
 912         }
 913
 914         t1 = ktime_get();
 915
 916         rc = stop_machine(pseries_lpar_resize_hpt_commit, &state, NULL);
 917
 918         t2 = ktime_get();
 919
 920         if (rc != 0) {
 921                 switch (state.commit_rc) {
 922                 case H_PTEG_FULL:
 923                         return -ENOSPC;
 924
 925                 default:
 926                         pr_warn("Unexpected error %d from H_RESIZE_HPT_COMMIT\n",
 927                                 state.commit_rc);
 928                         return -EIO;
 929                 };
 930         }
 931
 932         pr_info("HPT resize to shift %lu complete (%lld ms / %lld ms)\n",
 933                 shift, (long long) ktime_ms_delta(t1, t0),
 934                 (long long) ktime_ms_delta(t2, t1));
 935
 936         return 0;
 937 }
 938
 939 static int pseries_lpar_register_process_table(unsigned long base,
 940                         unsigned long page_size, unsigned long table_size)
 941 {
 942         long rc;
 943         unsigned long flags = 0;
 944
 945         if (table_size)
 946                 flags |= PROC_TABLE_NEW;
 947         if (radix_enabled())
 948                 flags |= PROC_TABLE_RADIX | PROC_TABLE_GTSE;
 949         else
 950                 flags |= PROC_TABLE_HPT_SLB;
 951         for (;;) {
 952                 rc = plpar_hcall_norets(H_REGISTER_PROC_TBL, flags, base,
 953                                         page_size, table_size);
 954                 if (!H_IS_LONG_BUSY(rc))
 955                         break;
 956                 mdelay(get_longbusy_msecs(rc));
 957         }
 958         if (rc != H_SUCCESS) {
 959                 pr_err("Failed to register process table (rc=%ld)\n", rc);
 960                 BUG();
 961         }
 962         return rc;
 963 }
 964
 965 void __init hpte_init_pseries(void)
 966 {
 967         mmu_hash_ops.hpte_invalidate     = pSeries_lpar_hpte_invalidate;
 968         mmu_hash_ops.hpte_updatepp       = pSeries_lpar_hpte_updatepp;
 969         mmu_hash_ops.hpte_updateboltedpp = pSeries_lpar_hpte_updateboltedpp;
 970         mmu_hash_ops.hpte_insert         = pSeries_lpar_hpte_insert;
 971         mmu_hash_ops.hpte_remove         = pSeries_lpar_hpte_remove;
 972         mmu_hash_ops.hpte_removebolted   = pSeries_lpar_hpte_removebolted;
 973         mmu_hash_ops.flush_hash_range    = pSeries_lpar_flush_hash_range;
 974         mmu_hash_ops.hpte_clear_all      = pseries_hpte_clear_all;
 975         mmu_hash_ops.hugepage_invalidate = pSeries_lpar_hugepage_invalidate;
 976         register_process_table           = pseries_lpar_register_process_table;
 977
 978         if (firmware_has_feature(FW_FEATURE_HPT_RESIZE))
 979                 mmu_hash_ops.resize_hpt = pseries_lpar_resize_hpt;
 980 }
 981
 982 void radix_init_pseries(void)
 983 {
 984         pr_info("Using radix MMU under hypervisor\n");
 985         register_process_table = pseries_lpar_register_process_table;
 986 }
 987
 988 #ifdef CONFIG_PPC_SMLPAR
 989 #define CMO_FREE_HINT_DEFAULT 1
 990 static int cmo_free_hint_flag = CMO_FREE_HINT_DEFAULT;
 991
 992 static int __init cmo_free_hint(char *str)
 993 {
 994         char *parm;
 995         parm = strstrip(str);
 996
 997         if (strcasecmp(parm, "no") == 0 || strcasecmp(parm, "off") == 0) {
 998                 pr_info("%s: CMO free page hinting is not active.\n", __func__);
 999                 cmo_free_hint_flag = 0;
1000                 return 1;
1001         }
1002
1003         cmo_free_hint_flag = 1;
1004         pr_info("%s: CMO free page hinting is active.\n", __func__);
1005
1006         if (strcasecmp(parm, "yes") == 0 || strcasecmp(parm, "on") == 0)
1007                 return 1;
1008
1009         return 0;
1010 }
1011
1012 __setup("cmo_free_hint=", cmo_free_hint);
1013
1014 static void pSeries_set_page_state(struct page *page, int order,
1015                                    unsigned long state)
1016 {
1017         int i, j;
1018         unsigned long cmo_page_sz, addr;
1019
1020         cmo_page_sz = cmo_get_page_size();
1021         addr = __pa((unsigned long)page_address(page));
1022
1023         for (i = 0; i < (1 << order); i++, addr += PAGE_SIZE) {
1024                 for (j = 0; j < PAGE_SIZE; j += cmo_page_sz)
1025                         plpar_hcall_norets(H_PAGE_INIT, state, addr + j, 0);
1026         }
1027 }
1028
1029 void arch_free_page(struct page *page, int order)
1030 {
1031         if (radix_enabled())
1032                 return;
1033         if (!cmo_free_hint_flag || !firmware_has_feature(FW_FEATURE_CMO))
1034                 return;
1035
1036         pSeries_set_page_state(page, order, H_PAGE_SET_UNUSED);
1037 }
1038 EXPORT_SYMBOL(arch_free_page);
1039
1040 #endif /* CONFIG_PPC_SMLPAR */
1041 #endif /* CONFIG_PPC_BOOK3S_64 */
1042
1043 #ifdef CONFIG_TRACEPOINTS
1044 #ifdef CONFIG_JUMP_LABEL
1045 struct static_key hcall_tracepoint_key = STATIC_KEY_INIT;
1046
1047 int hcall_tracepoint_regfunc(void)
1048 {
1049         static_key_slow_inc(&hcall_tracepoint_key);
1050         return 0;
1051 }
1052
1053 void hcall_tracepoint_unregfunc(void)
1054 {
1055         static_key_slow_dec(&hcall_tracepoint_key);
1056 }
1057 #else
1058 /*
1059  * We optimise our hcall path by placing hcall_tracepoint_refcount
1060  * directly in the TOC so we can check if the hcall tracepoints are
1061  * enabled via a single load.
1062  */
1063
1064 /* NB: reg/unreg are called while guarded with the tracepoints_mutex */
1065 extern long hcall_tracepoint_refcount;
1066
1067 int hcall_tracepoint_regfunc(void)
1068 {
1069         hcall_tracepoint_refcount++;
1070         return 0;
1071 }
1072
1073 void hcall_tracepoint_unregfunc(void)
1074 {
1075         hcall_tracepoint_refcount--;
1076 }
1077 #endif
1078
1079 /*
1080  * Since the tracing code might execute hcalls we need to guard against
1081  * recursion. One example of this are spinlocks calling H_YIELD on
1082  * shared processor partitions.
1083  */
1084 static DEFINE_PER_CPU(unsigned int, hcall_trace_depth);
1085
1086
1087 void __trace_hcall_entry(unsigned long opcode, unsigned long *args)
1088 {
1089         unsigned long flags;
1090         unsigned int *depth;
1091
1092         /*
1093          * We cannot call tracepoints inside RCU idle regions which
1094          * means we must not trace H_CEDE.
1095          */
1096         if (opcode == H_CEDE)
1097                 return;
1098
1099         local_irq_save(flags);
1100
1101         depth = this_cpu_ptr(&hcall_trace_depth);
1102
1103         if (*depth)
1104                 goto out;
1105
1106         (*depth)++;
1107         preempt_disable();
1108         trace_hcall_entry(opcode, args);
1109         (*depth)--;
1110
1111 out:
1112         local_irq_restore(flags);
1113 }
1114
1115 void __trace_hcall_exit(long opcode, long retval, unsigned long *retbuf)
1116 {
1117         unsigned long flags;
1118         unsigned int *depth;
1119
1120         if (opcode == H_CEDE)
1121                 return;
1122
1123         local_irq_save(flags);
1124
1125         depth = this_cpu_ptr(&hcall_trace_depth);
1126
1127         if (*depth)
1128                 goto out;
1129
1130         (*depth)++;
1131         trace_hcall_exit(opcode, retval, retbuf);
1132         preempt_enable();
1133         (*depth)--;
1134
1135 out:
1136         local_irq_restore(flags);
1137 }
1138 #endif
1139
1140 /**
1141  * h_get_mpp
1142  * H_GET_MPP hcall returns info in 7 parms
1143  */
1144 int h_get_mpp(struct hvcall_mpp_data *mpp_data)
1145 {
1146         int rc;
1147         unsigned long retbuf[PLPAR_HCALL9_BUFSIZE];
1148
1149         rc = plpar_hcall9(H_GET_MPP, retbuf);
1150
1151         mpp_data->entitled_mem = retbuf[0];
1152         mpp_data->mapped_mem = retbuf[1];
1153
1154         mpp_data->group_num = (retbuf[2] >> 2 * 8) & 0xffff;
1155         mpp_data->pool_num = retbuf[2] & 0xffff;
1156
1157         mpp_data->mem_weight = (retbuf[3] >> 7 * 8) & 0xff;
1158         mpp_data->unallocated_mem_weight = (retbuf[3] >> 6 * 8) & 0xff;
1159         mpp_data->unallocated_entitlement = retbuf[3] & 0xffffffffffffUL;
1160
1161         mpp_data->pool_size = retbuf[4];
1162         mpp_data->loan_request = retbuf[5];
1163         mpp_data->backing_mem = retbuf[6];
1164
1165         return rc;
1166 }
1167 EXPORT_SYMBOL(h_get_mpp);
1168
1169 int h_get_mpp_x(struct hvcall_mpp_x_data *mpp_x_data)
1170 {
1171         int rc;
1172         unsigned long retbuf[PLPAR_HCALL9_BUFSIZE] = { 0 };
1173
1174         rc = plpar_hcall9(H_GET_MPP_X, retbuf);
1175
1176         mpp_x_data->coalesced_bytes = retbuf[0];
1177         mpp_x_data->pool_coalesced_bytes = retbuf[1];
1178         mpp_x_data->pool_purr_cycles = retbuf[2];
1179         mpp_x_data->pool_spurr_cycles = retbuf[3];
1180
1181         return rc;
1182 }
1183
1184 static unsigned long vsid_unscramble(unsigned long vsid, int ssize)
1185 {
1186         unsigned long protovsid;
1187         unsigned long va_bits = VA_BITS;
1188         unsigned long modinv, vsid_modulus;
1189         unsigned long max_mod_inv, tmp_modinv;
1190
1191         if (!mmu_has_feature(MMU_FTR_68_BIT_VA))
1192                 va_bits = 65;
1193
1194         if (ssize == MMU_SEGSIZE_256M) {
1195                 modinv = VSID_MULINV_256M;
1196                 vsid_modulus = ((1UL << (va_bits - SID_SHIFT)) - 1);
1197         } else {
1198                 modinv = VSID_MULINV_1T;
1199                 vsid_modulus = ((1UL << (va_bits - SID_SHIFT_1T)) - 1);
1200         }
1201
1202         /*
1203          * vsid outside our range.
1204          */
1205         if (vsid >= vsid_modulus)
1206                 return 0;
1207
1208         /*
1209          * If modinv is the modular multiplicate inverse of (x % vsid_modulus)
1210          * and vsid = (protovsid * x) % vsid_modulus, then we say:
1211          *   protovsid = (vsid * modinv) % vsid_modulus
1212          */
1213
1214         /* Check if (vsid * modinv) overflow (63 bits) */
1215         max_mod_inv = 0x7fffffffffffffffull / vsid;
1216         if (modinv < max_mod_inv)
1217                 return (vsid * modinv) % vsid_modulus;
1218
1219         tmp_modinv = modinv/max_mod_inv;
1220         modinv %= max_mod_inv;
1221
1222         protovsid = (((vsid * max_mod_inv) % vsid_modulus) * tmp_modinv) % vsid_modulus;
1223         protovsid = (protovsid + vsid * modinv) % vsid_modulus;
1224
1225         return protovsid;
1226 }
1227
1228 static int __init reserve_vrma_context_id(void)
1229 {
1230         unsigned long protovsid;
1231
1232         /*
1233          * Reserve context ids which map to reserved virtual addresses. For now
1234          * we only reserve the context id which maps to the VRMA VSID. We ignore
1235          * the addresses in "ibm,adjunct-virtual-addresses" because we don't
1236          * enable adjunct support via the "ibm,client-architecture-support"
1237          * interface.
1238          */
1239         protovsid = vsid_unscramble(VRMA_VSID, MMU_SEGSIZE_1T);
1240         hash__reserve_context_id(protovsid >> ESID_BITS_1T);
1241         return 0;
1242 }
1243 machine_device_initcall(pseries, reserve_vrma_context_id);
1244
1245 #ifdef CONFIG_DEBUG_FS
1246 /* debugfs file interface for vpa data */
1247 static ssize_t vpa_file_read(struct file *filp, char __user *buf, size_t len,
1248                               loff_t *pos)
1249 {
1250         int cpu = (long)filp->private_data;
1251         struct lppaca *lppaca = &lppaca_of(cpu);
1252
1253         return simple_read_from_buffer(buf, len, pos, lppaca,
1254                                 sizeof(struct lppaca));
1255 }
1256
1257 static const struct file_operations vpa_fops = {
1258         .open           = simple_open,
1259         .read           = vpa_file_read,
1260         .llseek         = default_llseek,
1261 };
1262
1263 static int __init vpa_debugfs_init(void)
1264 {
1265         char name[16];
1266         long i;
1267         static struct dentry *vpa_dir;
1268
1269         if (!firmware_has_feature(FW_FEATURE_SPLPAR))
1270                 return 0;
1271
1272         vpa_dir = debugfs_create_dir("vpa", powerpc_debugfs_root);
1273         if (!vpa_dir) {
1274                 pr_warn("%s: can't create vpa root dir\n", __func__);
1275                 return -ENOMEM;
1276         }
1277
1278         /* set up the per-cpu vpa file*/
1279         for_each_possible_cpu(i) {
1280                 struct dentry *d;
1281
1282                 sprintf(name, "cpu-%ld", i);
1283
1284                 d = debugfs_create_file(name, 0400, vpa_dir, (void *)i,
1285                                         &vpa_fops);
1286                 if (!d) {
1287                         pr_warn("%s: can't create per-cpu vpa file\n",
1288                                         __func__);
1289                         return -ENOMEM;
1290                 }
1291         }
1292
1293         return 0;
1294 }
1295 machine_arch_initcall(pseries, vpa_debugfs_init);
1296 #endif /* CONFIG_DEBUG_FS */