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) 2004-2005 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 "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_COMPACT_NODES];
  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  * Given a nasid, get the physical address of the  partition's reserved page
  85  * for that nasid. This function returns 0 on any error.
  86  */
  87 static u64
  88 xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
  89 {
  90         bte_result_t bte_res;
  91         s64 status;
  92         u64 cookie = 0;
  93         u64 rp_pa = nasid;      /* seed with nasid */
  94         u64 len = 0;
  95
  96
  97         while (1) {
  98
  99                 status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
 100                                                                 &len);
 101
 102                 dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
 103                         "0x%016lx, address=0x%016lx, len=0x%016lx\n",
 104                         status, cookie, rp_pa, len);
 105
 106                 if (status != SALRET_MORE_PASSES) {
 107                         break;
 108                 }
 109
 110                 if (len > buf_size) {
 111                         dev_err(xpc_part, "len (=0x%016lx) > buf_size\n", len);
 112                         status = SALRET_ERROR;
 113                         break;
 114                 }
 115
 116                 bte_res = xp_bte_copy(rp_pa, ia64_tpa(buf), buf_size,
 117                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 118                 if (bte_res != BTE_SUCCESS) {
 119                         dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
 120                         status = SALRET_ERROR;
 121                         break;
 122                 }
 123         }
 124
 125         if (status != SALRET_OK) {
 126                 rp_pa = 0;
 127         }
 128         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
 129         return rp_pa;
 130 }
 131
 132
 133 /*
 134  * Fill the partition reserved page with the information needed by
 135  * other partitions to discover we are alive and establish initial
 136  * communications.
 137  */
 138 struct xpc_rsvd_page *
 139 xpc_rsvd_page_init(void)
 140 {
 141         struct xpc_rsvd_page *rp;
 142         AMO_t *amos_page;
 143         u64 rp_pa, nasid_array = 0;
 144         int i, ret;
 145
 146
 147         /* get the local reserved page's address */
 148
 149         rp_pa = xpc_get_rsvd_page_pa(cnodeid_to_nasid(0),
 150                                         (u64) xpc_remote_copy_buffer,
 151                                                 XPC_RP_HEADER_SIZE +
 152                                                         L1_CACHE_BYTES);
 153         if (rp_pa == 0) {
 154                 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
 155                 return NULL;
 156         }
 157         rp = (struct xpc_rsvd_page *) __va(rp_pa);
 158
 159         if (rp->partid != sn_partition_id) {
 160                 dev_err(xpc_part, "the reserved page's partid of %d should be "
 161                         "%d\n", rp->partid, sn_partition_id);
 162                 return NULL;
 163         }
 164
 165         rp->version = XPC_RP_VERSION;
 166
 167         /* establish the actual sizes of the nasid masks */
 168         if (rp->SAL_version == 1) {
 169                 /* SAL_version 1 didn't set the nasids_size field */
 170                 rp->nasids_size = 128;
 171         }
 172         xp_nasid_mask_bytes = rp->nasids_size;
 173         xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
 174
 175         /* setup the pointers to the various items in the reserved page */
 176         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
 177         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
 178         xpc_vars = XPC_RP_VARS(rp);
 179         xpc_vars_part = XPC_RP_VARS_PART(rp);
 180
 181         /*
 182          * Before clearing xpc_vars, see if a page of AMOs had been previously
 183          * allocated. If not we'll need to allocate one and set permissions
 184          * so that cross-partition AMOs are allowed.
 185          *
 186          * The allocated AMO page needs MCA reporting to remain disabled after
 187          * XPC has unloaded.  To make this work, we keep a copy of the pointer
 188          * to this page (i.e., amos_page) in the struct xpc_vars structure,
 189          * which is pointed to by the reserved page, and re-use that saved copy
 190          * on subsequent loads of XPC. This AMO page is never freed, and its
 191          * memory protections are never restricted.
 192          */
 193         if ((amos_page = xpc_vars->amos_page) == NULL) {
 194                 amos_page = (AMO_t *) TO_AMO(uncached_alloc_page(0));
 195                 if (amos_page == NULL) {
 196                         dev_err(xpc_part, "can't allocate page of AMOs\n");
 197                         return NULL;
 198                 }
 199
 200                 /*
 201                  * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
 202                  * when xpc_allow_IPI_ops() is called via xpc_hb_init().
 203                  */
 204                 if (!enable_shub_wars_1_1()) {
 205                         ret = sn_change_memprotect(ia64_tpa((u64) amos_page),
 206                                         PAGE_SIZE, SN_MEMPROT_ACCESS_CLASS_1,
 207                                         &nasid_array);
 208                         if (ret != 0) {
 209                                 dev_err(xpc_part, "can't change memory "
 210                                         "protections\n");
 211                                 uncached_free_page(__IA64_UNCACHED_OFFSET |
 212                                                    TO_PHYS((u64) amos_page));
 213                                 return NULL;
 214                         }
 215                 }
 216         } else if (!IS_AMO_ADDRESS((u64) amos_page)) {
 217                 /*
 218                  * EFI's XPBOOT can also set amos_page in the reserved page,
 219                  * but it happens to leave it as an uncached physical address
 220                  * and we need it to be an uncached virtual, so we'll have to
 221                  * convert it.
 222                  */
 223                 if (!IS_AMO_PHYS_ADDRESS((u64) amos_page)) {
 224                         dev_err(xpc_part, "previously used amos_page address "
 225                                 "is bad = 0x%p\n", (void *) amos_page);
 226                         return NULL;
 227                 }
 228                 amos_page = (AMO_t *) TO_AMO((u64) amos_page);
 229         }
 230
 231         /* clear xpc_vars */
 232         memset(xpc_vars, 0, sizeof(struct xpc_vars));
 233
 234         xpc_vars->version = XPC_V_VERSION;
 235         xpc_vars->act_nasid = cpuid_to_nasid(0);
 236         xpc_vars->act_phys_cpuid = cpu_physical_id(0);
 237         xpc_vars->vars_part_pa = __pa(xpc_vars_part);
 238         xpc_vars->amos_page_pa = ia64_tpa((u64) amos_page);
 239         xpc_vars->amos_page = amos_page;  /* save for next load of XPC */
 240
 241
 242         /* clear xpc_vars_part */
 243         memset((u64 *) xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
 244                                                         XP_MAX_PARTITIONS);
 245
 246         /* initialize the activate IRQ related AMO variables */
 247         for (i = 0; i < xp_nasid_mask_words; i++) {
 248                 (void) xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
 249         }
 250
 251         /* initialize the engaged remote partitions related AMO variables */
 252         (void) xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
 253         (void) xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
 254
 255         /* timestamp of when reserved page was setup by XPC */
 256         rp->stamp = CURRENT_TIME;
 257
 258         /*
 259          * This signifies to the remote partition that our reserved
 260          * page is initialized.
 261          */
 262         rp->vars_pa = __pa(xpc_vars);
 263
 264         return rp;
 265 }
 266
 267
 268 /*
 269  * Change protections to allow IPI operations (and AMO operations on
 270  * Shub 1.1 systems).
 271  */
 272 void
 273 xpc_allow_IPI_ops(void)
 274 {
 275         int node;
 276         int nasid;
 277
 278
 279         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
 280
 281         if (is_shub2()) {
 282                 xpc_sh2_IPI_access0 =
 283                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
 284                 xpc_sh2_IPI_access1 =
 285                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
 286                 xpc_sh2_IPI_access2 =
 287                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
 288                 xpc_sh2_IPI_access3 =
 289                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
 290
 291                 for_each_online_node(node) {
 292                         nasid = cnodeid_to_nasid(node);
 293                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
 294                                                                 -1UL);
 295                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
 296                                                                 -1UL);
 297                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
 298                                                                 -1UL);
 299                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
 300                                                                 -1UL);
 301                 }
 302
 303         } else {
 304                 xpc_sh1_IPI_access =
 305                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
 306
 307                 for_each_online_node(node) {
 308                         nasid = cnodeid_to_nasid(node);
 309                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
 310                                                                 -1UL);
 311
 312                         /*
 313                          * Since the BIST collides with memory operations on
 314                          * SHUB 1.1 sn_change_memprotect() cannot be used.
 315                          */
 316                         if (enable_shub_wars_1_1()) {
 317                                 /* open up everything */
 318                                 xpc_prot_vec[node] = (u64) HUB_L((u64 *)
 319                                                 GLOBAL_MMR_ADDR(nasid,
 320                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0));
 321                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
 322                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
 323                                                                 -1UL);
 324                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
 325                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
 326                                                                 -1UL);
 327                         }
 328                 }
 329         }
 330 }
 331
 332
 333 /*
 334  * Restrict protections to disallow IPI operations (and AMO operations on
 335  * Shub 1.1 systems).
 336  */
 337 void
 338 xpc_restrict_IPI_ops(void)
 339 {
 340         int node;
 341         int nasid;
 342
 343
 344         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
 345
 346         if (is_shub2()) {
 347
 348                 for_each_online_node(node) {
 349                         nasid = cnodeid_to_nasid(node);
 350                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
 351                                                         xpc_sh2_IPI_access0);
 352                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
 353                                                         xpc_sh2_IPI_access1);
 354                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
 355                                                         xpc_sh2_IPI_access2);
 356                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
 357                                                         xpc_sh2_IPI_access3);
 358                 }
 359
 360         } else {
 361
 362                 for_each_online_node(node) {
 363                         nasid = cnodeid_to_nasid(node);
 364                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
 365                                                         xpc_sh1_IPI_access);
 366
 367                         if (enable_shub_wars_1_1()) {
 368                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
 369                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
 370                                                         xpc_prot_vec[node]);
 371                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
 372                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
 373                                                         xpc_prot_vec[node]);
 374                         }
 375                 }
 376         }
 377 }
 378
 379
 380 /*
 381  * At periodic intervals, scan through all active partitions and ensure
 382  * their heartbeat is still active.  If not, the partition is deactivated.
 383  */
 384 void
 385 xpc_check_remote_hb(void)
 386 {
 387         struct xpc_vars *remote_vars;
 388         struct xpc_partition *part;
 389         partid_t partid;
 390         bte_result_t bres;
 391
 392
 393         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
 394
 395         for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
 396
 397                 if (xpc_exiting) {
 398                         break;
 399                 }
 400
 401                 if (partid == sn_partition_id) {
 402                         continue;
 403                 }
 404
 405                 part = &xpc_partitions[partid];
 406
 407                 if (part->act_state == XPC_P_INACTIVE ||
 408                                 part->act_state == XPC_P_DEACTIVATING) {
 409                         continue;
 410                 }
 411
 412                 /* pull the remote_hb cache line */
 413                 bres = xp_bte_copy(part->remote_vars_pa,
 414                                         ia64_tpa((u64) remote_vars),
 415                                         XPC_RP_VARS_SIZE,
 416                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 417                 if (bres != BTE_SUCCESS) {
 418                         XPC_DEACTIVATE_PARTITION(part,
 419                                                 xpc_map_bte_errors(bres));
 420                         continue;
 421                 }
 422
 423                 dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
 424                         " = %ld, kdb_status = %ld, HB_mask = 0x%lx\n", partid,
 425                         remote_vars->heartbeat, part->last_heartbeat,
 426                         remote_vars->kdb_status,
 427                         remote_vars->heartbeating_to_mask);
 428
 429                 if (((remote_vars->heartbeat == part->last_heartbeat) &&
 430                         (remote_vars->kdb_status == 0)) ||
 431                              !xpc_hb_allowed(sn_partition_id, remote_vars)) {
 432
 433                         XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
 434                         continue;
 435                 }
 436
 437                 part->last_heartbeat = remote_vars->heartbeat;
 438         }
 439 }
 440
 441
 442 /*
 443  * Get a copy of a portion of the remote partition's rsvd page.
 444  *
 445  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
 446  * is large enough to contain a copy of their reserved page header and
 447  * part_nasids mask.
 448  */
 449 static enum xpc_retval
 450 xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 451                 struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
 452 {
 453         int bres, i;
 454
 455
 456         /* get the reserved page's physical address */
 457
 458         *remote_rp_pa = xpc_get_rsvd_page_pa(nasid, (u64) remote_rp,
 459                                                 XPC_RP_HEADER_SIZE +
 460                                                         xp_nasid_mask_bytes);
 461         if (*remote_rp_pa == 0) {
 462                 return xpcNoRsvdPageAddr;
 463         }
 464
 465
 466         /* pull over the reserved page header and part_nasids mask */
 467
 468         bres = xp_bte_copy(*remote_rp_pa, ia64_tpa((u64) remote_rp),
 469                                 XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes,
 470                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 471         if (bres != BTE_SUCCESS) {
 472                 return xpc_map_bte_errors(bres);
 473         }
 474
 475
 476         if (discovered_nasids != NULL) {
 477                 u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
 478
 479
 480                 for (i = 0; i < xp_nasid_mask_words; i++) {
 481                         discovered_nasids[i] |= remote_part_nasids[i];
 482                 }
 483         }
 484
 485
 486         /* check that the partid is for another partition */
 487
 488         if (remote_rp->partid < 1 ||
 489                                 remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
 490                 return xpcInvalidPartid;
 491         }
 492
 493         if (remote_rp->partid == sn_partition_id) {
 494                 return xpcLocalPartid;
 495         }
 496
 497
 498         if (XPC_VERSION_MAJOR(remote_rp->version) !=
 499                                         XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
 500                 return xpcBadVersion;
 501         }
 502
 503         return xpcSuccess;
 504 }
 505
 506
 507 /*
 508  * Get a copy of the remote partition's XPC variables from the reserved page.
 509  *
 510  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
 511  * assumed to be of size XPC_RP_VARS_SIZE.
 512  */
 513 static enum xpc_retval
 514 xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
 515 {
 516         int bres;
 517
 518
 519         if (remote_vars_pa == 0) {
 520                 return xpcVarsNotSet;
 521         }
 522
 523
 524         /* pull over the cross partition variables */
 525
 526         bres = xp_bte_copy(remote_vars_pa, ia64_tpa((u64) remote_vars),
 527                                 XPC_RP_VARS_SIZE,
 528                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 529         if (bres != BTE_SUCCESS) {
 530                 return xpc_map_bte_errors(bres);
 531         }
 532
 533         if (XPC_VERSION_MAJOR(remote_vars->version) !=
 534                                         XPC_VERSION_MAJOR(XPC_V_VERSION)) {
 535                 return xpcBadVersion;
 536         }
 537
 538         return xpcSuccess;
 539 }
 540
 541
 542 /*
 543  * Update the remote partition's info.
 544  */
 545 static void
 546 xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
 547                 struct timespec *remote_rp_stamp, u64 remote_rp_pa,
 548                 u64 remote_vars_pa, struct xpc_vars *remote_vars)
 549 {
 550         part->remote_rp_version = remote_rp_version;
 551         dev_dbg(xpc_part, "  remote_rp_version = 0x%016lx\n",
 552                 part->remote_rp_version);
 553
 554         part->remote_rp_stamp = *remote_rp_stamp;
 555         dev_dbg(xpc_part, "  remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
 556                 part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
 557
 558         part->remote_rp_pa = remote_rp_pa;
 559         dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
 560
 561         part->remote_vars_pa = remote_vars_pa;
 562         dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
 563                 part->remote_vars_pa);
 564
 565         part->last_heartbeat = remote_vars->heartbeat;
 566         dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
 567                 part->last_heartbeat);
 568
 569         part->remote_vars_part_pa = remote_vars->vars_part_pa;
 570         dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
 571                 part->remote_vars_part_pa);
 572
 573         part->remote_act_nasid = remote_vars->act_nasid;
 574         dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
 575                 part->remote_act_nasid);
 576
 577         part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
 578         dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
 579                 part->remote_act_phys_cpuid);
 580
 581         part->remote_amos_page_pa = remote_vars->amos_page_pa;
 582         dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
 583                 part->remote_amos_page_pa);
 584
 585         part->remote_vars_version = remote_vars->version;
 586         dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
 587                 part->remote_vars_version);
 588 }
 589
 590
 591 /*
 592  * Prior code has determined the nasid which generated an IPI.  Inspect
 593  * that nasid to determine if its partition needs to be activated or
 594  * deactivated.
 595  *
 596  * A partition is consider "awaiting activation" if our partition
 597  * flags indicate it is not active and it has a heartbeat.  A
 598  * partition is considered "awaiting deactivation" if our partition
 599  * flags indicate it is active but it has no heartbeat or it is not
 600  * sending its heartbeat to us.
 601  *
 602  * To determine the heartbeat, the remote nasid must have a properly
 603  * initialized reserved page.
 604  */
 605 static void
 606 xpc_identify_act_IRQ_req(int nasid)
 607 {
 608         struct xpc_rsvd_page *remote_rp;
 609         struct xpc_vars *remote_vars;
 610         u64 remote_rp_pa;
 611         u64 remote_vars_pa;
 612         int remote_rp_version;
 613         int reactivate = 0;
 614         int stamp_diff;
 615         struct timespec remote_rp_stamp = { 0, 0 };
 616         partid_t partid;
 617         struct xpc_partition *part;
 618         enum xpc_retval ret;
 619
 620
 621         /* pull over the reserved page structure */
 622
 623         remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;
 624
 625         ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
 626         if (ret != xpcSuccess) {
 627                 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
 628                         "which sent interrupt, reason=%d\n", nasid, ret);
 629                 return;
 630         }
 631
 632         remote_vars_pa = remote_rp->vars_pa;
 633         remote_rp_version = remote_rp->version;
 634         if (XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 635                 remote_rp_stamp = remote_rp->stamp;
 636         }
 637         partid = remote_rp->partid;
 638         part = &xpc_partitions[partid];
 639
 640
 641         /* pull over the cross partition variables */
 642
 643         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
 644
 645         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
 646         if (ret != xpcSuccess) {
 647
 648                 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
 649                         "which sent interrupt, reason=%d\n", nasid, ret);
 650
 651                 XPC_DEACTIVATE_PARTITION(part, ret);
 652                 return;
 653         }
 654
 655
 656         part->act_IRQ_rcvd++;
 657
 658         dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
 659                 "%ld:0x%lx\n", (int) nasid, (int) partid, part->act_IRQ_rcvd,
 660                 remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
 661
 662         if (xpc_partition_disengaged(part) &&
 663                                         part->act_state == XPC_P_INACTIVE) {
 664
 665                 xpc_update_partition_info(part, remote_rp_version,
 666                                         &remote_rp_stamp, remote_rp_pa,
 667                                         remote_vars_pa, remote_vars);
 668
 669                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 670                         if (xpc_partition_disengage_requested(1UL << partid)) {
 671                                 /*
 672                                  * Other side is waiting on us to disengage,
 673                                  * even though we already have.
 674                                  */
 675                                 return;
 676                         }
 677                 } else {
 678                         /* other side doesn't support disengage requests */
 679                         xpc_clear_partition_disengage_request(1UL << partid);
 680                 }
 681
 682                 xpc_activate_partition(part);
 683                 return;
 684         }
 685
 686         DBUG_ON(part->remote_rp_version == 0);
 687         DBUG_ON(part->remote_vars_version == 0);
 688
 689         if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
 690                 DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
 691                                                         remote_vars_version));
 692
 693                 if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 694                         DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
 695                                                                 version));
 696                         /* see if the other side rebooted */
 697                         if (part->remote_amos_page_pa ==
 698                                 remote_vars->amos_page_pa &&
 699                                         xpc_hb_allowed(sn_partition_id,
 700                                                                 remote_vars)) {
 701                                 /* doesn't look that way, so ignore the IPI */
 702                                 return;
 703                         }
 704                 }
 705
 706                 /*
 707                  * Other side rebooted and previous XPC didn't support the
 708                  * disengage request, so we don't need to do anything special.
 709                  */
 710
 711                 xpc_update_partition_info(part, remote_rp_version,
 712                                                 &remote_rp_stamp, remote_rp_pa,
 713                                                 remote_vars_pa, remote_vars);
 714                 part->reactivate_nasid = nasid;
 715                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
 716                 return;
 717         }
 718
 719         DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
 720
 721         if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 722                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 723
 724                 /*
 725                  * Other side rebooted and previous XPC did support the
 726                  * disengage request, but the new one doesn't.
 727                  */
 728
 729                 xpc_clear_partition_engaged(1UL << partid);
 730                 xpc_clear_partition_disengage_request(1UL << partid);
 731
 732                 xpc_update_partition_info(part, remote_rp_version,
 733                                                 &remote_rp_stamp, remote_rp_pa,
 734                                                 remote_vars_pa, remote_vars);
 735                 reactivate = 1;
 736
 737         } else {
 738                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 739
 740                 stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
 741                                                         &remote_rp_stamp);
 742                 if (stamp_diff != 0) {
 743                         DBUG_ON(stamp_diff >= 0);
 744
 745                         /*
 746                          * Other side rebooted and the previous XPC did support
 747                          * the disengage request, as does the new one.
 748                          */
 749
 750                         DBUG_ON(xpc_partition_engaged(1UL << partid));
 751                         DBUG_ON(xpc_partition_disengage_requested(1UL <<
 752                                                                 partid));
 753
 754                         xpc_update_partition_info(part, remote_rp_version,
 755                                                 &remote_rp_stamp, remote_rp_pa,
 756                                                 remote_vars_pa, remote_vars);
 757                         reactivate = 1;
 758                 }
 759         }
 760
 761         if (!xpc_partition_disengaged(part)) {
 762                 /* still waiting on other side to disengage from us */
 763                 return;
 764         }
 765
 766         if (reactivate) {
 767                 part->reactivate_nasid = nasid;
 768                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
 769
 770         } else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
 771                         xpc_partition_disengage_requested(1UL << partid)) {
 772                 XPC_DEACTIVATE_PARTITION(part, xpcOtherGoingDown);
 773         }
 774 }
 775
 776
 777 /*
 778  * Loop through the activation AMO variables and process any bits
 779  * which are set.  Each bit indicates a nasid sending a partition
 780  * activation or deactivation request.
 781  *
 782  * Return #of IRQs detected.
 783  */
 784 int
 785 xpc_identify_act_IRQ_sender(void)
 786 {
 787         int word, bit;
 788         u64 nasid_mask;
 789         u64 nasid;                      /* remote nasid */
 790         int n_IRQs_detected = 0;
 791         AMO_t *act_amos;
 792
 793
 794         act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
 795
 796
 797         /* scan through act AMO variable looking for non-zero entries */
 798         for (word = 0; word < xp_nasid_mask_words; word++) {
 799
 800                 if (xpc_exiting) {
 801                         break;
 802                 }
 803
 804                 nasid_mask = xpc_IPI_receive(&act_amos[word]);
 805                 if (nasid_mask == 0) {
 806                         /* no IRQs from nasids in this variable */
 807                         continue;
 808                 }
 809
 810                 dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
 811                         nasid_mask);
 812
 813
 814                 /*
 815                  * If this nasid has been added to the machine since
 816                  * our partition was reset, this will retain the
 817                  * remote nasid in our reserved pages machine mask.
 818                  * This is used in the event of module reload.
 819                  */
 820                 xpc_mach_nasids[word] |= nasid_mask;
 821
 822
 823                 /* locate the nasid(s) which sent interrupts */
 824
 825                 for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
 826                         if (nasid_mask & (1UL << bit)) {
 827                                 n_IRQs_detected++;
 828                                 nasid = XPC_NASID_FROM_W_B(word, bit);
 829                                 dev_dbg(xpc_part, "interrupt from nasid %ld\n",
 830                                         nasid);
 831                                 xpc_identify_act_IRQ_req(nasid);
 832                         }
 833                 }
 834         }
 835         return n_IRQs_detected;
 836 }
 837
 838
 839 /*
 840  * See if the other side has responded to a partition disengage request
 841  * from us.
 842  */
 843 int
 844 xpc_partition_disengaged(struct xpc_partition *part)
 845 {
 846         partid_t partid = XPC_PARTID(part);
 847         int disengaged;
 848
 849
 850         disengaged = (xpc_partition_engaged(1UL << partid) == 0);
 851         if (part->disengage_request_timeout) {
 852                 if (!disengaged) {
 853                         if (jiffies < part->disengage_request_timeout) {
 854                                 /* timelimit hasn't been reached yet */
 855                                 return 0;
 856                         }
 857
 858                         /*
 859                          * Other side hasn't responded to our disengage
 860                          * request in a timely fashion, so assume it's dead.
 861                          */
 862
 863                         xpc_clear_partition_engaged(1UL << partid);
 864                         disengaged = 1;
 865                 }
 866                 part->disengage_request_timeout = 0;
 867
 868                 /* cancel the timer function, provided it's not us */
 869                 if (!in_interrupt()) {
 870                         del_singleshot_timer_sync(&part->
 871                                                       disengage_request_timer);
 872                 }
 873
 874                 DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
 875                                         part->act_state != XPC_P_INACTIVE);
 876                 if (part->act_state != XPC_P_INACTIVE) {
 877                         xpc_wakeup_channel_mgr(part);
 878                 }
 879
 880                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 881                         xpc_cancel_partition_disengage_request(part);
 882                 }
 883         }
 884         return disengaged;
 885 }
 886
 887
 888 /*
 889  * Mark specified partition as active.
 890  */
 891 enum xpc_retval
 892 xpc_mark_partition_active(struct xpc_partition *part)
 893 {
 894         unsigned long irq_flags;
 895         enum xpc_retval ret;
 896
 897
 898         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
 899
 900         spin_lock_irqsave(&part->act_lock, irq_flags);
 901         if (part->act_state == XPC_P_ACTIVATING) {
 902                 part->act_state = XPC_P_ACTIVE;
 903                 ret = xpcSuccess;
 904         } else {
 905                 DBUG_ON(part->reason == xpcSuccess);
 906                 ret = part->reason;
 907         }
 908         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 909
 910         return ret;
 911 }
 912
 913
 914 /*
 915  * Notify XPC that the partition is down.
 916  */
 917 void
 918 xpc_deactivate_partition(const int line, struct xpc_partition *part,
 919                                 enum xpc_retval reason)
 920 {
 921         unsigned long irq_flags;
 922
 923
 924         spin_lock_irqsave(&part->act_lock, irq_flags);
 925
 926         if (part->act_state == XPC_P_INACTIVE) {
 927                 XPC_SET_REASON(part, reason, line);
 928                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 929                 if (reason == xpcReactivating) {
 930                         /* we interrupt ourselves to reactivate partition */
 931                         xpc_IPI_send_reactivate(part);
 932                 }
 933                 return;
 934         }
 935         if (part->act_state == XPC_P_DEACTIVATING) {
 936                 if ((part->reason == xpcUnloading && reason != xpcUnloading) ||
 937                                         reason == xpcReactivating) {
 938                         XPC_SET_REASON(part, reason, line);
 939                 }
 940                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 941                 return;
 942         }
 943
 944         part->act_state = XPC_P_DEACTIVATING;
 945         XPC_SET_REASON(part, reason, line);
 946
 947         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 948
 949         if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 950                 xpc_request_partition_disengage(part);
 951                 xpc_IPI_send_disengage(part);
 952
 953                 /* set a timelimit on the disengage request */
 954                 part->disengage_request_timeout = jiffies +
 955                                         (xpc_disengage_request_timelimit * HZ);
 956                 part->disengage_request_timer.expires =
 957                                         part->disengage_request_timeout;
 958                 add_timer(&part->disengage_request_timer);
 959         }
 960
 961         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
 962                 XPC_PARTID(part), reason);
 963
 964         xpc_partition_going_down(part, reason);
 965 }
 966
 967
 968 /*
 969  * Mark specified partition as inactive.
 970  */
 971 void
 972 xpc_mark_partition_inactive(struct xpc_partition *part)
 973 {
 974         unsigned long irq_flags;
 975
 976
 977         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
 978                 XPC_PARTID(part));
 979
 980         spin_lock_irqsave(&part->act_lock, irq_flags);
 981         part->act_state = XPC_P_INACTIVE;
 982         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 983         part->remote_rp_pa = 0;
 984 }
 985
 986
 987 /*
 988  * SAL has provided a partition and machine mask.  The partition mask
 989  * contains a bit for each even nasid in our partition.  The machine
 990  * mask contains a bit for each even nasid in the entire machine.
 991  *
 992  * Using those two bit arrays, we can determine which nasids are
 993  * known in the machine.  Each should also have a reserved page
 994  * initialized if they are available for partitioning.
 995  */
 996 void
 997 xpc_discovery(void)
 998 {
 999         void *remote_rp_base;
1000         struct xpc_rsvd_page *remote_rp;
1001         struct xpc_vars *remote_vars;
1002         u64 remote_rp_pa;
1003         u64 remote_vars_pa;
1004         int region;
1005         int region_size;
1006         int max_regions;
1007         int nasid;
1008         struct xpc_rsvd_page *rp;
1009         partid_t partid;
1010         struct xpc_partition *part;
1011         u64 *discovered_nasids;
1012         enum xpc_retval ret;
1013
1014
1015         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
1016                                                 xp_nasid_mask_bytes,
1017                                                 GFP_KERNEL, &remote_rp_base);
1018         if (remote_rp == NULL) {
1019                 return;
1020         }
1021         remote_vars = (struct xpc_vars *) remote_rp;
1022
1023
1024         discovered_nasids = kmalloc(sizeof(u64) * xp_nasid_mask_words,
1025                                                         GFP_KERNEL);
1026         if (discovered_nasids == NULL) {
1027                 kfree(remote_rp_base);
1028                 return;
1029         }
1030         memset(discovered_nasids, 0, sizeof(u64) * xp_nasid_mask_words);
1031
1032         rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
1033
1034         /*
1035          * The term 'region' in this context refers to the minimum number of
1036          * nodes that can comprise an access protection grouping. The access
1037          * protection is in regards to memory, IOI and IPI.
1038          */
1039         max_regions = 64;
1040         region_size = sn_region_size;
1041
1042         switch (region_size) {
1043         case 128:
1044                 max_regions *= 2;
1045         case 64:
1046                 max_regions *= 2;
1047         case 32:
1048                 max_regions *= 2;
1049                 region_size = 16;
1050                 DBUG_ON(!is_shub2());
1051         }
1052
1053         for (region = 0; region < max_regions; region++) {
1054
1055                 if ((volatile int) xpc_exiting) {
1056                         break;
1057                 }
1058
1059                 dev_dbg(xpc_part, "searching region %d\n", region);
1060
1061                 for (nasid = (region * region_size * 2);
1062                      nasid < ((region + 1) * region_size * 2);
1063                      nasid += 2) {
1064
1065                         if ((volatile int) xpc_exiting) {
1066                                 break;
1067                         }
1068
1069                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
1070
1071
1072                         if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
1073                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
1074                                         "part of the local partition; skipping "
1075                                         "region\n", nasid);
1076                                 break;
1077                         }
1078
1079                         if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
1080                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
1081                                         "not on Numa-Link network at reset\n",
1082                                         nasid);
1083                                 continue;
1084                         }
1085
1086                         if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
1087                                 dev_dbg(xpc_part, "Nasid %d is part of a "
1088                                         "partition which was previously "
1089                                         "discovered\n", nasid);
1090                                 continue;
1091                         }
1092
1093
1094                         /* pull over the reserved page structure */
1095
1096                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
1097                                               remote_rp, &remote_rp_pa);
1098                         if (ret != xpcSuccess) {
1099                                 dev_dbg(xpc_part, "unable to get reserved page "
1100                                         "from nasid %d, reason=%d\n", nasid,
1101                                         ret);
1102
1103                                 if (ret == xpcLocalPartid) {
1104                                         break;
1105                                 }
1106                                 continue;
1107                         }
1108
1109                         remote_vars_pa = remote_rp->vars_pa;
1110
1111                         partid = remote_rp->partid;
1112                         part = &xpc_partitions[partid];
1113
1114
1115                         /* pull over the cross partition variables */
1116
1117                         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
1118                         if (ret != xpcSuccess) {
1119                                 dev_dbg(xpc_part, "unable to get XPC variables "
1120                                         "from nasid %d, reason=%d\n", nasid,
1121                                         ret);
1122
1123                                 XPC_DEACTIVATE_PARTITION(part, ret);
1124                                 continue;
1125                         }
1126
1127                         if (part->act_state != XPC_P_INACTIVE) {
1128                                 dev_dbg(xpc_part, "partition %d on nasid %d is "
1129                                         "already activating\n", partid, nasid);
1130                                 break;
1131                         }
1132
1133                         /*
1134                          * Register the remote partition's AMOs with SAL so it
1135                          * can handle and cleanup errors within that address
1136                          * range should the remote partition go down. We don't
1137                          * unregister this range because it is difficult to
1138                          * tell when outstanding writes to the remote partition
1139                          * are finished and thus when it is thus safe to
1140                          * unregister. This should not result in wasted space
1141                          * in the SAL xp_addr_region table because we should
1142                          * get the same page for remote_act_amos_pa after
1143                          * module reloads and system reboots.
1144                          */
1145                         if (sn_register_xp_addr_region(
1146                                             remote_vars->amos_page_pa,
1147                                                         PAGE_SIZE, 1) < 0) {
1148                                 dev_dbg(xpc_part, "partition %d failed to "
1149                                         "register xp_addr region 0x%016lx\n",
1150                                         partid, remote_vars->amos_page_pa);
1151
1152                                 XPC_SET_REASON(part, xpcPhysAddrRegFailed,
1153                                                 __LINE__);
1154                                 break;
1155                         }
1156
1157                         /*
1158                          * The remote nasid is valid and available.
1159                          * Send an interrupt to that nasid to notify
1160                          * it that we are ready to begin activation.
1161                          */
1162                         dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
1163                                 "nasid %d, phys_cpuid 0x%x\n",
1164                                 remote_vars->amos_page_pa,
1165                                 remote_vars->act_nasid,
1166                                 remote_vars->act_phys_cpuid);
1167
1168                         if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
1169                                                                 version)) {
1170                                 part->remote_amos_page_pa =
1171                                                 remote_vars->amos_page_pa;
1172                                 xpc_mark_partition_disengaged(part);
1173                                 xpc_cancel_partition_disengage_request(part);
1174                         }
1175                         xpc_IPI_send_activate(remote_vars);
1176                 }
1177         }
1178
1179         kfree(discovered_nasids);
1180         kfree(remote_rp_base);
1181 }
1182
1183
1184 /*
1185  * Given a partid, get the nasids owned by that partition from the
1186  * remote partition's reserved page.
1187  */
1188 enum xpc_retval
1189 xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
1190 {
1191         struct xpc_partition *part;
1192         u64 part_nasid_pa;
1193         int bte_res;
1194
1195
1196         part = &xpc_partitions[partid];
1197         if (part->remote_rp_pa == 0) {
1198                 return xpcPartitionDown;
1199         }
1200
1201         memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
1202
1203         part_nasid_pa = (u64) XPC_RP_PART_NASIDS(part->remote_rp_pa);
1204
1205         bte_res = xp_bte_copy(part_nasid_pa, ia64_tpa((u64) nasid_mask),
1206                         xp_nasid_mask_bytes, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
1207
1208         return xpc_map_bte_errors(bte_res);
1209 }
1210