arch/ia64/sn/kernel/xpc_partition.c

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (c) 2004-2006 Silicon Graphics, Inc.  All Rights Reserved.
   7  */
   8
   9
  10 /*
  11  * Cross Partition Communication (XPC) partition support.
  12  *
  13  *      This is the part of XPC that detects the presence/absence of
  14  *      other partitions. It provides a heartbeat and monitors the
  15  *      heartbeats of other partitions.
  16  *
  17  */
  18
  19
  20 #include <linux/kernel.h>
  21 #include <linux/sysctl.h>
  22 #include <linux/cache.h>
  23 #include <linux/mmzone.h>
  24 #include <linux/nodemask.h>
  25 #include <asm/uncached.h>
  26 #include <asm/sn/bte.h>
  27 #include <asm/sn/intr.h>
  28 #include <asm/sn/sn_sal.h>
  29 #include <asm/sn/nodepda.h>
  30 #include <asm/sn/addrs.h>
  31 #include <asm/sn/xpc.h>
  32
  33
  34 /* XPC is exiting flag */
  35 int xpc_exiting;
  36
  37
  38 /* SH_IPI_ACCESS shub register value on startup */
  39 static u64 xpc_sh1_IPI_access;
  40 static u64 xpc_sh2_IPI_access0;
  41 static u64 xpc_sh2_IPI_access1;
  42 static u64 xpc_sh2_IPI_access2;
  43 static u64 xpc_sh2_IPI_access3;
  44
  45
  46 /* original protection values for each node */
  47 u64 xpc_prot_vec[MAX_NUMNODES];
  48
  49
  50 /* this partition's reserved page pointers */
  51 struct xpc_rsvd_page *xpc_rsvd_page;
  52 static u64 *xpc_part_nasids;
  53 static u64 *xpc_mach_nasids;
  54 struct xpc_vars *xpc_vars;
  55 struct xpc_vars_part *xpc_vars_part;
  56
  57 static int xp_nasid_mask_bytes; /* actual size in bytes of nasid mask */
  58 static int xp_nasid_mask_words; /* actual size in words of nasid mask */
  59
  60
  61 /*
  62  * For performance reasons, each entry of xpc_partitions[] is cacheline
  63  * aligned. And xpc_partitions[] is padded with an additional entry at the
  64  * end so that the last legitimate entry doesn't share its cacheline with
  65  * another variable.
  66  */
  67 struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
  68
  69
  70 /*
  71  * Generic buffer used to store a local copy of portions of a remote
  72  * partition's reserved page (either its header and part_nasids mask,
  73  * or its vars).
  74  *
  75  * xpc_discovery runs only once and is a seperate thread that is
  76  * very likely going to be processing in parallel with receiving
  77  * interrupts.
  78  */
  79 char ____cacheline_aligned xpc_remote_copy_buffer[XPC_RP_HEADER_SIZE +
  80                                                         XP_NASID_MASK_BYTES];
  81
  82
  83 /*
  84  * Guarantee that the kmalloc'd memory is cacheline aligned.
  85  */
  86 static void *
  87 xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
  88 {
  89         /* see if kmalloc will give us cachline aligned memory by default */
  90         *base = kmalloc(size, flags);
  91         if (*base == NULL) {
  92                 return NULL;
  93         }
  94         if ((u64) *base == L1_CACHE_ALIGN((u64) *base)) {
  95                 return *base;
  96         }
  97         kfree(*base);
  98
  99         /* nope, we'll have to do it ourselves */
 100         *base = kmalloc(size + L1_CACHE_BYTES, flags);
 101         if (*base == NULL) {
 102                 return NULL;
 103         }
 104         return (void *) L1_CACHE_ALIGN((u64) *base);
 105 }
 106
 107
 108 /*
 109  * Given a nasid, get the physical address of the  partition's reserved page
 110  * for that nasid. This function returns 0 on any error.
 111  */
 112 static u64
 113 xpc_get_rsvd_page_pa(int nasid)
 114 {
 115         bte_result_t bte_res;
 116         s64 status;
 117         u64 cookie = 0;
 118         u64 rp_pa = nasid;      /* seed with nasid */
 119         u64 len = 0;
 120         u64 buf = buf;
 121         u64 buf_len = 0;
 122         void *buf_base = NULL;
 123
 124
 125         while (1) {
 126
 127                 status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
 128                                                                 &len);
 129
 130                 dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
 131                         "0x%016lx, address=0x%016lx, len=0x%016lx\n",
 132                         status, cookie, rp_pa, len);
 133
 134                 if (status != SALRET_MORE_PASSES) {
 135                         break;
 136                 }
 137
 138                 if (L1_CACHE_ALIGN(len) > buf_len) {
 139                         if (buf_base != NULL) {
 140                                 kfree(buf_base);
 141                         }
 142                         buf_len = L1_CACHE_ALIGN(len);
 143                         buf = (u64) xpc_kmalloc_cacheline_aligned(buf_len,
 144                                                         GFP_KERNEL, &buf_base);
 145                         if (buf_base == NULL) {
 146                                 dev_err(xpc_part, "unable to kmalloc "
 147                                         "len=0x%016lx\n", buf_len);
 148                                 status = SALRET_ERROR;
 149                                 break;
 150                         }
 151                 }
 152
 153                 bte_res = xp_bte_copy(rp_pa, ia64_tpa(buf), buf_len,
 154                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 155                 if (bte_res != BTE_SUCCESS) {
 156                         dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
 157                         status = SALRET_ERROR;
 158                         break;
 159                 }
 160         }
 161
 162         if (buf_base != NULL) {
 163                 kfree(buf_base);
 164         }
 165
 166         if (status != SALRET_OK) {
 167                 rp_pa = 0;
 168         }
 169         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
 170         return rp_pa;
 171 }
 172
 173
 174 /*
 175  * Fill the partition reserved page with the information needed by
 176  * other partitions to discover we are alive and establish initial
 177  * communications.
 178  */
 179 struct xpc_rsvd_page *
 180 xpc_rsvd_page_init(void)
 181 {
 182         struct xpc_rsvd_page *rp;
 183         AMO_t *amos_page;
 184         u64 rp_pa, nasid_array = 0;
 185         int i, ret;
 186
 187
 188         /* get the local reserved page's address */
 189
 190         preempt_disable();
 191         rp_pa = xpc_get_rsvd_page_pa(cpuid_to_nasid(smp_processor_id()));
 192         preempt_enable();
 193         if (rp_pa == 0) {
 194                 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
 195                 return NULL;
 196         }
 197         rp = (struct xpc_rsvd_page *) __va(rp_pa);
 198
 199         if (rp->partid != sn_partition_id) {
 200                 dev_err(xpc_part, "the reserved page's partid of %d should be "
 201                         "%d\n", rp->partid, sn_partition_id);
 202                 return NULL;
 203         }
 204
 205         rp->version = XPC_RP_VERSION;
 206
 207         /* establish the actual sizes of the nasid masks */
 208         if (rp->SAL_version == 1) {
 209                 /* SAL_version 1 didn't set the nasids_size field */
 210                 rp->nasids_size = 128;
 211         }
 212         xp_nasid_mask_bytes = rp->nasids_size;
 213         xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
 214
 215         /* setup the pointers to the various items in the reserved page */
 216         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
 217         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
 218         xpc_vars = XPC_RP_VARS(rp);
 219         xpc_vars_part = XPC_RP_VARS_PART(rp);
 220
 221         /*
 222          * Before clearing xpc_vars, see if a page of AMOs had been previously
 223          * allocated. If not we'll need to allocate one and set permissions
 224          * so that cross-partition AMOs are allowed.
 225          *
 226          * The allocated AMO page needs MCA reporting to remain disabled after
 227          * XPC has unloaded.  To make this work, we keep a copy of the pointer
 228          * to this page (i.e., amos_page) in the struct xpc_vars structure,
 229          * which is pointed to by the reserved page, and re-use that saved copy
 230          * on subsequent loads of XPC. This AMO page is never freed, and its
 231          * memory protections are never restricted.
 232          */
 233         if ((amos_page = xpc_vars->amos_page) == NULL) {
 234                 amos_page = (AMO_t *) TO_AMO(uncached_alloc_page(0));
 235                 if (amos_page == NULL) {
 236                         dev_err(xpc_part, "can't allocate page of AMOs\n");
 237                         return NULL;
 238                 }
 239
 240                 /*
 241                  * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
 242                  * when xpc_allow_IPI_ops() is called via xpc_hb_init().
 243                  */
 244                 if (!enable_shub_wars_1_1()) {
 245                         ret = sn_change_memprotect(ia64_tpa((u64) amos_page),
 246                                         PAGE_SIZE, SN_MEMPROT_ACCESS_CLASS_1,
 247                                         &nasid_array);
 248                         if (ret != 0) {
 249                                 dev_err(xpc_part, "can't change memory "
 250                                         "protections\n");
 251                                 uncached_free_page(__IA64_UNCACHED_OFFSET |
 252                                                    TO_PHYS((u64) amos_page));
 253                                 return NULL;
 254                         }
 255                 }
 256         } else if (!IS_AMO_ADDRESS((u64) amos_page)) {
 257                 /*
 258                  * EFI's XPBOOT can also set amos_page in the reserved page,
 259                  * but it happens to leave it as an uncached physical address
 260                  * and we need it to be an uncached virtual, so we'll have to
 261                  * convert it.
 262                  */
 263                 if (!IS_AMO_PHYS_ADDRESS((u64) amos_page)) {
 264                         dev_err(xpc_part, "previously used amos_page address "
 265                                 "is bad = 0x%p\n", (void *) amos_page);
 266                         return NULL;
 267                 }
 268                 amos_page = (AMO_t *) TO_AMO((u64) amos_page);
 269         }
 270
 271         /* clear xpc_vars */
 272         memset(xpc_vars, 0, sizeof(struct xpc_vars));
 273
 274         xpc_vars->version = XPC_V_VERSION;
 275         xpc_vars->act_nasid = cpuid_to_nasid(0);
 276         xpc_vars->act_phys_cpuid = cpu_physical_id(0);
 277         xpc_vars->vars_part_pa = __pa(xpc_vars_part);
 278         xpc_vars->amos_page_pa = ia64_tpa((u64) amos_page);
 279         xpc_vars->amos_page = amos_page;  /* save for next load of XPC */
 280
 281
 282         /* clear xpc_vars_part */
 283         memset((u64 *) xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
 284                                                         XP_MAX_PARTITIONS);
 285
 286         /* initialize the activate IRQ related AMO variables */
 287         for (i = 0; i < xp_nasid_mask_words; i++) {
 288                 (void) xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
 289         }
 290
 291         /* initialize the engaged remote partitions related AMO variables */
 292         (void) xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
 293         (void) xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
 294
 295         /* timestamp of when reserved page was setup by XPC */
 296         rp->stamp = CURRENT_TIME;
 297
 298         /*
 299          * This signifies to the remote partition that our reserved
 300          * page is initialized.
 301          */
 302         rp->vars_pa = __pa(xpc_vars);
 303
 304         return rp;
 305 }
 306
 307
 308 /*
 309  * Change protections to allow IPI operations (and AMO operations on
 310  * Shub 1.1 systems).
 311  */
 312 void
 313 xpc_allow_IPI_ops(void)
 314 {
 315         int node;
 316         int nasid;
 317
 318
 319         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
 320
 321         if (is_shub2()) {
 322                 xpc_sh2_IPI_access0 =
 323                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
 324                 xpc_sh2_IPI_access1 =
 325                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
 326                 xpc_sh2_IPI_access2 =
 327                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
 328                 xpc_sh2_IPI_access3 =
 329                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
 330
 331                 for_each_online_node(node) {
 332                         nasid = cnodeid_to_nasid(node);
 333                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
 334                                                                 -1UL);
 335                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
 336                                                                 -1UL);
 337                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
 338                                                                 -1UL);
 339                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
 340                                                                 -1UL);
 341                 }
 342
 343         } else {
 344                 xpc_sh1_IPI_access =
 345                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
 346
 347                 for_each_online_node(node) {
 348                         nasid = cnodeid_to_nasid(node);
 349                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
 350                                                                 -1UL);
 351
 352                         /*
 353                          * Since the BIST collides with memory operations on
 354                          * SHUB 1.1 sn_change_memprotect() cannot be used.
 355                          */
 356                         if (enable_shub_wars_1_1()) {
 357                                 /* open up everything */
 358                                 xpc_prot_vec[node] = (u64) HUB_L((u64 *)
 359                                                 GLOBAL_MMR_ADDR(nasid,
 360                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0));
 361                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
 362                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
 363                                                                 -1UL);
 364                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
 365                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
 366                                                                 -1UL);
 367                         }
 368                 }
 369         }
 370 }
 371
 372
 373 /*
 374  * Restrict protections to disallow IPI operations (and AMO operations on
 375  * Shub 1.1 systems).
 376  */
 377 void
 378 xpc_restrict_IPI_ops(void)
 379 {
 380         int node;
 381         int nasid;
 382
 383
 384         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
 385
 386         if (is_shub2()) {
 387
 388                 for_each_online_node(node) {
 389                         nasid = cnodeid_to_nasid(node);
 390                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
 391                                                         xpc_sh2_IPI_access0);
 392                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
 393                                                         xpc_sh2_IPI_access1);
 394                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
 395                                                         xpc_sh2_IPI_access2);
 396                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
 397                                                         xpc_sh2_IPI_access3);
 398                 }
 399
 400         } else {
 401
 402                 for_each_online_node(node) {
 403                         nasid = cnodeid_to_nasid(node);
 404                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
 405                                                         xpc_sh1_IPI_access);
 406
 407                         if (enable_shub_wars_1_1()) {
 408                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
 409                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
 410                                                         xpc_prot_vec[node]);
 411                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
 412                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
 413                                                         xpc_prot_vec[node]);
 414                         }
 415                 }
 416         }
 417 }
 418
 419
 420 /*
 421  * At periodic intervals, scan through all active partitions and ensure
 422  * their heartbeat is still active.  If not, the partition is deactivated.
 423  */
 424 void
 425 xpc_check_remote_hb(void)
 426 {
 427         struct xpc_vars *remote_vars;
 428         struct xpc_partition *part;
 429         partid_t partid;
 430         bte_result_t bres;
 431
 432
 433         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
 434
 435         for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
 436
 437                 if (xpc_exiting) {
 438                         break;
 439                 }
 440
 441                 if (partid == sn_partition_id) {
 442                         continue;
 443                 }
 444
 445                 part = &xpc_partitions[partid];
 446
 447                 if (part->act_state == XPC_P_INACTIVE ||
 448                                 part->act_state == XPC_P_DEACTIVATING) {
 449                         continue;
 450                 }
 451
 452                 /* pull the remote_hb cache line */
 453                 bres = xp_bte_copy(part->remote_vars_pa,
 454                                         ia64_tpa((u64) remote_vars),
 455                                         XPC_RP_VARS_SIZE,
 456                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 457                 if (bres != BTE_SUCCESS) {
 458                         XPC_DEACTIVATE_PARTITION(part,
 459                                                 xpc_map_bte_errors(bres));
 460                         continue;
 461                 }
 462
 463                 dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
 464                         " = %ld, heartbeat_offline = %ld, HB_mask = 0x%lx\n",
 465                         partid, remote_vars->heartbeat, part->last_heartbeat,
 466                         remote_vars->heartbeat_offline,
 467                         remote_vars->heartbeating_to_mask);
 468
 469                 if (((remote_vars->heartbeat == part->last_heartbeat) &&
 470                         (remote_vars->heartbeat_offline == 0)) ||
 471                              !xpc_hb_allowed(sn_partition_id, remote_vars)) {
 472
 473                         XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
 474                         continue;
 475                 }
 476
 477                 part->last_heartbeat = remote_vars->heartbeat;
 478         }
 479 }
 480
 481
 482 /*
 483  * Get a copy of a portion of the remote partition's rsvd page.
 484  *
 485  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
 486  * is large enough to contain a copy of their reserved page header and
 487  * part_nasids mask.
 488  */
 489 static enum xpc_retval
 490 xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 491                 struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
 492 {
 493         int bres, i;
 494
 495
 496         /* get the reserved page's physical address */
 497
 498         *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
 499         if (*remote_rp_pa == 0) {
 500                 return xpcNoRsvdPageAddr;
 501         }
 502
 503
 504         /* pull over the reserved page header and part_nasids mask */
 505
 506         bres = xp_bte_copy(*remote_rp_pa, ia64_tpa((u64) remote_rp),
 507                                 XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes,
 508                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 509         if (bres != BTE_SUCCESS) {
 510                 return xpc_map_bte_errors(bres);
 511         }
 512
 513
 514         if (discovered_nasids != NULL) {
 515                 u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
 516
 517
 518                 for (i = 0; i < xp_nasid_mask_words; i++) {
 519                         discovered_nasids[i] |= remote_part_nasids[i];
 520                 }
 521         }
 522
 523
 524         /* check that the partid is for another partition */
 525
 526         if (remote_rp->partid < 1 ||
 527                                 remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
 528                 return xpcInvalidPartid;
 529         }
 530
 531         if (remote_rp->partid == sn_partition_id) {
 532                 return xpcLocalPartid;
 533         }
 534
 535
 536         if (XPC_VERSION_MAJOR(remote_rp->version) !=
 537                                         XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
 538                 return xpcBadVersion;
 539         }
 540
 541         return xpcSuccess;
 542 }
 543
 544
 545 /*
 546  * Get a copy of the remote partition's XPC variables from the reserved page.
 547  *
 548  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
 549  * assumed to be of size XPC_RP_VARS_SIZE.
 550  */
 551 static enum xpc_retval
 552 xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
 553 {
 554         int bres;
 555
 556
 557         if (remote_vars_pa == 0) {
 558                 return xpcVarsNotSet;
 559         }
 560
 561
 562         /* pull over the cross partition variables */
 563
 564         bres = xp_bte_copy(remote_vars_pa, ia64_tpa((u64) remote_vars),
 565                                 XPC_RP_VARS_SIZE,
 566                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 567         if (bres != BTE_SUCCESS) {
 568                 return xpc_map_bte_errors(bres);
 569         }
 570
 571         if (XPC_VERSION_MAJOR(remote_vars->version) !=
 572                                         XPC_VERSION_MAJOR(XPC_V_VERSION)) {
 573                 return xpcBadVersion;
 574         }
 575
 576         return xpcSuccess;
 577 }
 578
 579
 580 /*
 581  * Update the remote partition's info.
 582  */
 583 static void
 584 xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
 585                 struct timespec *remote_rp_stamp, u64 remote_rp_pa,
 586                 u64 remote_vars_pa, struct xpc_vars *remote_vars)
 587 {
 588         part->remote_rp_version = remote_rp_version;
 589         dev_dbg(xpc_part, "  remote_rp_version = 0x%016lx\n",
 590                 part->remote_rp_version);
 591
 592         part->remote_rp_stamp = *remote_rp_stamp;
 593         dev_dbg(xpc_part, "  remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
 594                 part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
 595
 596         part->remote_rp_pa = remote_rp_pa;
 597         dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
 598
 599         part->remote_vars_pa = remote_vars_pa;
 600         dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
 601                 part->remote_vars_pa);
 602
 603         part->last_heartbeat = remote_vars->heartbeat;
 604         dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
 605                 part->last_heartbeat);
 606
 607         part->remote_vars_part_pa = remote_vars->vars_part_pa;
 608         dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
 609                 part->remote_vars_part_pa);
 610
 611         part->remote_act_nasid = remote_vars->act_nasid;
 612         dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
 613                 part->remote_act_nasid);
 614
 615         part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
 616         dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
 617                 part->remote_act_phys_cpuid);
 618
 619         part->remote_amos_page_pa = remote_vars->amos_page_pa;
 620         dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
 621                 part->remote_amos_page_pa);
 622
 623         part->remote_vars_version = remote_vars->version;
 624         dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
 625                 part->remote_vars_version);
 626 }
 627
 628
 629 /*
 630  * Prior code has determined the nasid which generated an IPI.  Inspect
 631  * that nasid to determine if its partition needs to be activated or
 632  * deactivated.
 633  *
 634  * A partition is consider "awaiting activation" if our partition
 635  * flags indicate it is not active and it has a heartbeat.  A
 636  * partition is considered "awaiting deactivation" if our partition
 637  * flags indicate it is active but it has no heartbeat or it is not
 638  * sending its heartbeat to us.
 639  *
 640  * To determine the heartbeat, the remote nasid must have a properly
 641  * initialized reserved page.
 642  */
 643 static void
 644 xpc_identify_act_IRQ_req(int nasid)
 645 {
 646         struct xpc_rsvd_page *remote_rp;
 647         struct xpc_vars *remote_vars;
 648         u64 remote_rp_pa;
 649         u64 remote_vars_pa;
 650         int remote_rp_version;
 651         int reactivate = 0;
 652         int stamp_diff;
 653         struct timespec remote_rp_stamp = { 0, 0 };
 654         partid_t partid;
 655         struct xpc_partition *part;
 656         enum xpc_retval ret;
 657
 658
 659         /* pull over the reserved page structure */
 660
 661         remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;
 662
 663         ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
 664         if (ret != xpcSuccess) {
 665                 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
 666                         "which sent interrupt, reason=%d\n", nasid, ret);
 667                 return;
 668         }
 669
 670         remote_vars_pa = remote_rp->vars_pa;
 671         remote_rp_version = remote_rp->version;
 672         if (XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 673                 remote_rp_stamp = remote_rp->stamp;
 674         }
 675         partid = remote_rp->partid;
 676         part = &xpc_partitions[partid];
 677
 678
 679         /* pull over the cross partition variables */
 680
 681         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
 682
 683         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
 684         if (ret != xpcSuccess) {
 685
 686                 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
 687                         "which sent interrupt, reason=%d\n", nasid, ret);
 688
 689                 XPC_DEACTIVATE_PARTITION(part, ret);
 690                 return;
 691         }
 692
 693
 694         part->act_IRQ_rcvd++;
 695
 696         dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
 697                 "%ld:0x%lx\n", (int) nasid, (int) partid, part->act_IRQ_rcvd,
 698                 remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
 699
 700         if (xpc_partition_disengaged(part) &&
 701                                         part->act_state == XPC_P_INACTIVE) {
 702
 703                 xpc_update_partition_info(part, remote_rp_version,
 704                                         &remote_rp_stamp, remote_rp_pa,
 705                                         remote_vars_pa, remote_vars);
 706
 707                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 708                         if (xpc_partition_disengage_requested(1UL << partid)) {
 709                                 /*
 710                                  * Other side is waiting on us to disengage,
 711                                  * even though we already have.
 712                                  */
 713                                 return;
 714                         }
 715                 } else {
 716                         /* other side doesn't support disengage requests */
 717                         xpc_clear_partition_disengage_request(1UL << partid);
 718                 }
 719
 720                 xpc_activate_partition(part);
 721                 return;
 722         }
 723
 724         DBUG_ON(part->remote_rp_version == 0);
 725         DBUG_ON(part->remote_vars_version == 0);
 726
 727         if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
 728                 DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
 729                                                         remote_vars_version));
 730
 731                 if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 732                         DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
 733                                                                 version));
 734                         /* see if the other side rebooted */
 735                         if (part->remote_amos_page_pa ==
 736                                 remote_vars->amos_page_pa &&
 737                                         xpc_hb_allowed(sn_partition_id,
 738                                                                 remote_vars)) {
 739                                 /* doesn't look that way, so ignore the IPI */
 740                                 return;
 741                         }
 742                 }
 743
 744                 /*
 745                  * Other side rebooted and previous XPC didn't support the
 746                  * disengage request, so we don't need to do anything special.
 747                  */
 748
 749                 xpc_update_partition_info(part, remote_rp_version,
 750                                                 &remote_rp_stamp, remote_rp_pa,
 751                                                 remote_vars_pa, remote_vars);
 752                 part->reactivate_nasid = nasid;
 753                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
 754                 return;
 755         }
 756
 757         DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
 758
 759         if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 760                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 761
 762                 /*
 763                  * Other side rebooted and previous XPC did support the
 764                  * disengage request, but the new one doesn't.
 765                  */
 766
 767                 xpc_clear_partition_engaged(1UL << partid);
 768                 xpc_clear_partition_disengage_request(1UL << partid);
 769
 770                 xpc_update_partition_info(part, remote_rp_version,
 771                                                 &remote_rp_stamp, remote_rp_pa,
 772                                                 remote_vars_pa, remote_vars);
 773                 reactivate = 1;
 774
 775         } else {
 776                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 777
 778                 stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
 779                                                         &remote_rp_stamp);
 780                 if (stamp_diff != 0) {
 781                         DBUG_ON(stamp_diff >= 0);
 782
 783                         /*
 784                          * Other side rebooted and the previous XPC did support
 785                          * the disengage request, as does the new one.
 786                          */
 787
 788                         DBUG_ON(xpc_partition_engaged(1UL << partid));
 789                         DBUG_ON(xpc_partition_disengage_requested(1UL <<
 790                                                                 partid));
 791
 792                         xpc_update_partition_info(part, remote_rp_version,
 793                                                 &remote_rp_stamp, remote_rp_pa,
 794                                                 remote_vars_pa, remote_vars);
 795                         reactivate = 1;
 796                 }
 797         }
 798
 799         if (part->disengage_request_timeout > 0 &&
 800                                         !xpc_partition_disengaged(part)) {
 801                 /* still waiting on other side to disengage from us */
 802                 return;
 803         }
 804
 805         if (reactivate) {
 806                 part->reactivate_nasid = nasid;
 807                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
 808
 809         } else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
 810                         xpc_partition_disengage_requested(1UL << partid)) {
 811                 XPC_DEACTIVATE_PARTITION(part, xpcOtherGoingDown);
 812         }
 813 }
 814
 815
 816 /*
 817  * Loop through the activation AMO variables and process any bits
 818  * which are set.  Each bit indicates a nasid sending a partition
 819  * activation or deactivation request.
 820  *
 821  * Return #of IRQs detected.
 822  */
 823 int
 824 xpc_identify_act_IRQ_sender(void)
 825 {
 826         int word, bit;
 827         u64 nasid_mask;
 828         u64 nasid;                      /* remote nasid */
 829         int n_IRQs_detected = 0;
 830         AMO_t *act_amos;
 831
 832
 833         act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
 834
 835
 836         /* scan through act AMO variable looking for non-zero entries */
 837         for (word = 0; word < xp_nasid_mask_words; word++) {
 838
 839                 if (xpc_exiting) {
 840                         break;
 841                 }
 842
 843                 nasid_mask = xpc_IPI_receive(&act_amos[word]);
 844                 if (nasid_mask == 0) {
 845                         /* no IRQs from nasids in this variable */
 846                         continue;
 847                 }
 848
 849                 dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
 850                         nasid_mask);
 851
 852
 853                 /*
 854                  * If this nasid has been added to the machine since
 855                  * our partition was reset, this will retain the
 856                  * remote nasid in our reserved pages machine mask.
 857                  * This is used in the event of module reload.
 858                  */
 859                 xpc_mach_nasids[word] |= nasid_mask;
 860
 861
 862                 /* locate the nasid(s) which sent interrupts */
 863
 864                 for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
 865                         if (nasid_mask & (1UL << bit)) {
 866                                 n_IRQs_detected++;
 867                                 nasid = XPC_NASID_FROM_W_B(word, bit);
 868                                 dev_dbg(xpc_part, "interrupt from nasid %ld\n",
 869                                         nasid);
 870                                 xpc_identify_act_IRQ_req(nasid);
 871                         }
 872                 }
 873         }
 874         return n_IRQs_detected;
 875 }
 876
 877
 878 /*
 879  * See if the other side has responded to a partition disengage request
 880  * from us.
 881  */
 882 int
 883 xpc_partition_disengaged(struct xpc_partition *part)
 884 {
 885         partid_t partid = XPC_PARTID(part);
 886         int disengaged;
 887
 888
 889         disengaged = (xpc_partition_engaged(1UL << partid) == 0);
 890         if (part->disengage_request_timeout) {
 891                 if (!disengaged) {
 892                         if (jiffies < part->disengage_request_timeout) {
 893                                 /* timelimit hasn't been reached yet */
 894                                 return 0;
 895                         }
 896
 897                         /*
 898                          * Other side hasn't responded to our disengage
 899                          * request in a timely fashion, so assume it's dead.
 900                          */
 901
 902                         dev_info(xpc_part, "disengage from remote partition %d "
 903                                 "timed out\n", partid);
 904                         xpc_disengage_request_timedout = 1;
 905                         xpc_clear_partition_engaged(1UL << partid);
 906                         disengaged = 1;
 907                 }
 908                 part->disengage_request_timeout = 0;
 909
 910                 /* cancel the timer function, provided it's not us */
 911                 if (!in_interrupt()) {
 912                         del_singleshot_timer_sync(&part->
 913                                                       disengage_request_timer);
 914                 }
 915
 916                 DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
 917                                         part->act_state != XPC_P_INACTIVE);
 918                 if (part->act_state != XPC_P_INACTIVE) {
 919                         xpc_wakeup_channel_mgr(part);
 920                 }
 921
 922                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 923                         xpc_cancel_partition_disengage_request(part);
 924                 }
 925         }
 926         return disengaged;
 927 }
 928
 929
 930 /*
 931  * Mark specified partition as active.
 932  */
 933 enum xpc_retval
 934 xpc_mark_partition_active(struct xpc_partition *part)
 935 {
 936         unsigned long irq_flags;
 937         enum xpc_retval ret;
 938
 939
 940         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
 941
 942         spin_lock_irqsave(&part->act_lock, irq_flags);
 943         if (part->act_state == XPC_P_ACTIVATING) {
 944                 part->act_state = XPC_P_ACTIVE;
 945                 ret = xpcSuccess;
 946         } else {
 947                 DBUG_ON(part->reason == xpcSuccess);
 948                 ret = part->reason;
 949         }
 950         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 951
 952         return ret;
 953 }
 954
 955
 956 /*
 957  * Notify XPC that the partition is down.
 958  */
 959 void
 960 xpc_deactivate_partition(const int line, struct xpc_partition *part,
 961                                 enum xpc_retval reason)
 962 {
 963         unsigned long irq_flags;
 964
 965
 966         spin_lock_irqsave(&part->act_lock, irq_flags);
 967
 968         if (part->act_state == XPC_P_INACTIVE) {
 969                 XPC_SET_REASON(part, reason, line);
 970                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 971                 if (reason == xpcReactivating) {
 972                         /* we interrupt ourselves to reactivate partition */
 973                         xpc_IPI_send_reactivate(part);
 974                 }
 975                 return;
 976         }
 977         if (part->act_state == XPC_P_DEACTIVATING) {
 978                 if ((part->reason == xpcUnloading && reason != xpcUnloading) ||
 979                                         reason == xpcReactivating) {
 980                         XPC_SET_REASON(part, reason, line);
 981                 }
 982                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 983                 return;
 984         }
 985
 986         part->act_state = XPC_P_DEACTIVATING;
 987         XPC_SET_REASON(part, reason, line);
 988
 989         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 990
 991         if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 992                 xpc_request_partition_disengage(part);
 993                 xpc_IPI_send_disengage(part);
 994
 995                 /* set a timelimit on the disengage request */
 996                 part->disengage_request_timeout = jiffies +
 997                                         (xpc_disengage_request_timelimit * HZ);
 998                 part->disengage_request_timer.expires =
 999                                         part->disengage_request_timeout;
1000                 add_timer(&part->disengage_request_timer);
1001         }
1002
1003         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
1004                 XPC_PARTID(part), reason);
1005
1006         xpc_partition_going_down(part, reason);
1007 }
1008
1009
1010 /*
1011  * Mark specified partition as inactive.
1012  */
1013 void
1014 xpc_mark_partition_inactive(struct xpc_partition *part)
1015 {
1016         unsigned long irq_flags;
1017
1018
1019         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
1020                 XPC_PARTID(part));
1021
1022         spin_lock_irqsave(&part->act_lock, irq_flags);
1023         part->act_state = XPC_P_INACTIVE;
1024         spin_unlock_irqrestore(&part->act_lock, irq_flags);
1025         part->remote_rp_pa = 0;
1026 }
1027
1028
1029 /*
1030  * SAL has provided a partition and machine mask.  The partition mask
1031  * contains a bit for each even nasid in our partition.  The machine
1032  * mask contains a bit for each even nasid in the entire machine.
1033  *
1034  * Using those two bit arrays, we can determine which nasids are
1035  * known in the machine.  Each should also have a reserved page
1036  * initialized if they are available for partitioning.
1037  */
1038 void
1039 xpc_discovery(void)
1040 {
1041         void *remote_rp_base;
1042         struct xpc_rsvd_page *remote_rp;
1043         struct xpc_vars *remote_vars;
1044         u64 remote_rp_pa;
1045         u64 remote_vars_pa;
1046         int region;
1047         int region_size;
1048         int max_regions;
1049         int nasid;
1050         struct xpc_rsvd_page *rp;
1051         partid_t partid;
1052         struct xpc_partition *part;
1053         u64 *discovered_nasids;
1054         enum xpc_retval ret;
1055
1056
1057         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
1058                                                 xp_nasid_mask_bytes,
1059                                                 GFP_KERNEL, &remote_rp_base);
1060         if (remote_rp == NULL) {
1061                 return;
1062         }
1063         remote_vars = (struct xpc_vars *) remote_rp;
1064
1065
1066         discovered_nasids = kzalloc(sizeof(u64) * xp_nasid_mask_words,
1067                                                         GFP_KERNEL);
1068         if (discovered_nasids == NULL) {
1069                 kfree(remote_rp_base);
1070                 return;
1071         }
1072
1073         rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
1074
1075         /*
1076          * The term 'region' in this context refers to the minimum number of
1077          * nodes that can comprise an access protection grouping. The access
1078          * protection is in regards to memory, IOI and IPI.
1079          */
1080         max_regions = 64;
1081         region_size = sn_region_size;
1082
1083         switch (region_size) {
1084         case 128:
1085                 max_regions *= 2;
1086         case 64:
1087                 max_regions *= 2;
1088         case 32:
1089                 max_regions *= 2;
1090                 region_size = 16;
1091                 DBUG_ON(!is_shub2());
1092         }
1093
1094         for (region = 0; region < max_regions; region++) {
1095
1096                 if ((volatile int) xpc_exiting) {
1097                         break;
1098                 }
1099
1100                 dev_dbg(xpc_part, "searching region %d\n", region);
1101
1102                 for (nasid = (region * region_size * 2);
1103                      nasid < ((region + 1) * region_size * 2);
1104                      nasid += 2) {
1105
1106                         if ((volatile int) xpc_exiting) {
1107                                 break;
1108                         }
1109
1110                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
1111
1112
1113                         if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
1114                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
1115                                         "part of the local partition; skipping "
1116                                         "region\n", nasid);
1117                                 break;
1118                         }
1119
1120                         if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
1121                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
1122                                         "not on Numa-Link network at reset\n",
1123                                         nasid);
1124                                 continue;
1125                         }
1126
1127                         if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
1128                                 dev_dbg(xpc_part, "Nasid %d is part of a "
1129                                         "partition which was previously "
1130                                         "discovered\n", nasid);
1131                                 continue;
1132                         }
1133
1134
1135                         /* pull over the reserved page structure */
1136
1137                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
1138                                               remote_rp, &remote_rp_pa);
1139                         if (ret != xpcSuccess) {
1140                                 dev_dbg(xpc_part, "unable to get reserved page "
1141                                         "from nasid %d, reason=%d\n", nasid,
1142                                         ret);
1143
1144                                 if (ret == xpcLocalPartid) {
1145                                         break;
1146                                 }
1147                                 continue;
1148                         }
1149
1150                         remote_vars_pa = remote_rp->vars_pa;
1151
1152                         partid = remote_rp->partid;
1153                         part = &xpc_partitions[partid];
1154
1155
1156                         /* pull over the cross partition variables */
1157
1158                         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
1159                         if (ret != xpcSuccess) {
1160                                 dev_dbg(xpc_part, "unable to get XPC variables "
1161                                         "from nasid %d, reason=%d\n", nasid,
1162                                         ret);
1163
1164                                 XPC_DEACTIVATE_PARTITION(part, ret);
1165                                 continue;
1166                         }
1167
1168                         if (part->act_state != XPC_P_INACTIVE) {
1169                                 dev_dbg(xpc_part, "partition %d on nasid %d is "
1170                                         "already activating\n", partid, nasid);
1171                                 break;
1172                         }
1173
1174                         /*
1175                          * Register the remote partition's AMOs with SAL so it
1176                          * can handle and cleanup errors within that address
1177                          * range should the remote partition go down. We don't
1178                          * unregister this range because it is difficult to
1179                          * tell when outstanding writes to the remote partition
1180                          * are finished and thus when it is thus safe to
1181                          * unregister. This should not result in wasted space
1182                          * in the SAL xp_addr_region table because we should
1183                          * get the same page for remote_act_amos_pa after
1184                          * module reloads and system reboots.
1185                          */
1186                         if (sn_register_xp_addr_region(
1187                                             remote_vars->amos_page_pa,
1188                                                         PAGE_SIZE, 1) < 0) {
1189                                 dev_dbg(xpc_part, "partition %d failed to "
1190                                         "register xp_addr region 0x%016lx\n",
1191                                         partid, remote_vars->amos_page_pa);
1192
1193                                 XPC_SET_REASON(part, xpcPhysAddrRegFailed,
1194                                                 __LINE__);
1195                                 break;
1196                         }
1197
1198                         /*
1199                          * The remote nasid is valid and available.
1200                          * Send an interrupt to that nasid to notify
1201                          * it that we are ready to begin activation.
1202                          */
1203                         dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
1204                                 "nasid %d, phys_cpuid 0x%x\n",
1205                                 remote_vars->amos_page_pa,
1206                                 remote_vars->act_nasid,
1207                                 remote_vars->act_phys_cpuid);
1208
1209                         if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
1210                                                                 version)) {
1211                                 part->remote_amos_page_pa =
1212                                                 remote_vars->amos_page_pa;
1213                                 xpc_mark_partition_disengaged(part);
1214                                 xpc_cancel_partition_disengage_request(part);
1215                         }
1216                         xpc_IPI_send_activate(remote_vars);
1217                 }
1218         }
1219
1220         kfree(discovered_nasids);
1221         kfree(remote_rp_base);
1222 }
1223
1224
1225 /*
1226  * Given a partid, get the nasids owned by that partition from the
1227  * remote partition's reserved page.
1228  */
1229 enum xpc_retval
1230 xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
1231 {
1232         struct xpc_partition *part;
1233         u64 part_nasid_pa;
1234         int bte_res;
1235
1236
1237         part = &xpc_partitions[partid];
1238         if (part->remote_rp_pa == 0) {
1239                 return xpcPartitionDown;
1240         }
1241
1242         memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
1243
1244         part_nasid_pa = (u64) XPC_RP_PART_NASIDS(part->remote_rp_pa);
1245
1246         bte_res = xp_bte_copy(part_nasid_pa, ia64_tpa((u64) nasid_mask),
1247                         xp_nasid_mask_bytes, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
1248
1249         return xpc_map_bte_errors(bte_res);
1250 }
1251