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