drivers/misc/sgi-xp/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) 2004-2008 Silicon Graphics, Inc.  All Rights Reserved.
   7  */
   8
   9 /*
  10  * Cross Partition Communication (XPC) partition support.
  11  *
  12  *      This is the part of XPC that detects the presence/absence of
  13  *      other partitions. It provides a heartbeat and monitors the
  14  *      heartbeats of other partitions.
  15  *
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/sysctl.h>
  20 #include <linux/cache.h>
  21 #include <linux/mmzone.h>
  22 #include <linux/nodemask.h>
  23 #include <asm/uncached.h>
  24 #include <asm/sn/bte.h>
  25 #include <asm/sn/intr.h>
  26 #include <asm/sn/sn_sal.h>
  27 #include <asm/sn/nodepda.h>
  28 #include <asm/sn/addrs.h>
  29 #include "xpc.h"
  30
  31 /* XPC is exiting flag */
  32 int xpc_exiting;
  33
  34 /* SH_IPI_ACCESS shub register value on startup */
  35 static u64 xpc_sh1_IPI_access;
  36 static u64 xpc_sh2_IPI_access0;
  37 static u64 xpc_sh2_IPI_access1;
  38 static u64 xpc_sh2_IPI_access2;
  39 static u64 xpc_sh2_IPI_access3;
  40
  41 /* original protection values for each node */
  42 u64 xpc_prot_vec[MAX_NUMNODES];
  43
  44 /* this partition's reserved page pointers */
  45 struct xpc_rsvd_page *xpc_rsvd_page;
  46 static u64 *xpc_part_nasids;
  47 static u64 *xpc_mach_nasids;
  48 struct xpc_vars *xpc_vars;
  49 struct xpc_vars_part *xpc_vars_part;
  50
  51 static int xp_nasid_mask_bytes; /* actual size in bytes of nasid mask */
  52 static int xp_nasid_mask_words; /* actual size in words of nasid mask */
  53
  54 /*
  55  * For performance reasons, each entry of xpc_partitions[] is cacheline
  56  * aligned. And xpc_partitions[] is padded with an additional entry at the
  57  * end so that the last legitimate entry doesn't share its cacheline with
  58  * another variable.
  59  */
  60 struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
  61
  62 /*
  63  * Generic buffer used to store a local copy of portions of a remote
  64  * partition's reserved page (either its header and part_nasids mask,
  65  * or its vars).
  66  */
  67 char *xpc_remote_copy_buffer;
  68 void *xpc_remote_copy_buffer_base;
  69
  70 /*
  71  * Guarantee that the kmalloc'd memory is cacheline aligned.
  72  */
  73 void *
  74 xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
  75 {
  76         /* see if kmalloc will give us cachline aligned memory by default */
  77         *base = kmalloc(size, flags);
  78         if (*base == NULL)
  79                 return NULL;
  80
  81         if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
  82                 return *base;
  83
  84         kfree(*base);
  85
  86         /* nope, we'll have to do it ourselves */
  87         *base = kmalloc(size + L1_CACHE_BYTES, flags);
  88         if (*base == NULL)
  89                 return NULL;
  90
  91         return (void *)L1_CACHE_ALIGN((u64)*base);
  92 }
  93
  94 /*
  95  * Given a nasid, get the physical address of the  partition's reserved page
  96  * for that nasid. This function returns 0 on any error.
  97  */
  98 static u64
  99 xpc_get_rsvd_page_pa(int nasid)
 100 {
 101         bte_result_t bte_res;
 102         s64 status;
 103         u64 cookie = 0;
 104         u64 rp_pa = nasid;      /* seed with nasid */
 105         u64 len = 0;
 106         u64 buf = buf;
 107         u64 buf_len = 0;
 108         void *buf_base = NULL;
 109
 110         while (1) {
 111
 112                 status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
 113                                                        &len);
 114
 115                 dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
 116                         "0x%016lx, address=0x%016lx, len=0x%016lx\n",
 117                         status, cookie, rp_pa, len);
 118
 119                 if (status != SALRET_MORE_PASSES)
 120                         break;
 121
 122                 if (L1_CACHE_ALIGN(len) > buf_len) {
 123                         kfree(buf_base);
 124                         buf_len = L1_CACHE_ALIGN(len);
 125                         buf = (u64)xpc_kmalloc_cacheline_aligned(buf_len,
 126                                                                  GFP_KERNEL,
 127                                                                  &buf_base);
 128                         if (buf_base == NULL) {
 129                                 dev_err(xpc_part, "unable to kmalloc "
 130                                         "len=0x%016lx\n", buf_len);
 131                                 status = SALRET_ERROR;
 132                                 break;
 133                         }
 134                 }
 135
 136                 bte_res = xp_bte_copy(rp_pa, buf, buf_len,
 137                                       (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 138                 if (bte_res != BTE_SUCCESS) {
 139                         dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
 140                         status = SALRET_ERROR;
 141                         break;
 142                 }
 143         }
 144
 145         kfree(buf_base);
 146
 147         if (status != SALRET_OK)
 148                 rp_pa = 0;
 149
 150         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
 151         return rp_pa;
 152 }
 153
 154 /*
 155  * Fill the partition reserved page with the information needed by
 156  * other partitions to discover we are alive and establish initial
 157  * communications.
 158  */
 159 struct xpc_rsvd_page *
 160 xpc_rsvd_page_init(void)
 161 {
 162         struct xpc_rsvd_page *rp;
 163         AMO_t *amos_page;
 164         u64 rp_pa, nasid_array = 0;
 165         int i, ret;
 166
 167         /* get the local reserved page's address */
 168
 169         preempt_disable();
 170         rp_pa = xpc_get_rsvd_page_pa(cpuid_to_nasid(smp_processor_id()));
 171         preempt_enable();
 172         if (rp_pa == 0) {
 173                 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
 174                 return NULL;
 175         }
 176         rp = (struct xpc_rsvd_page *)__va(rp_pa);
 177
 178         if (rp->partid != sn_partition_id) {
 179                 dev_err(xpc_part, "the reserved page's partid of %d should be "
 180                         "%d\n", rp->partid, sn_partition_id);
 181                 return NULL;
 182         }
 183
 184         rp->version = XPC_RP_VERSION;
 185
 186         /* establish the actual sizes of the nasid masks */
 187         if (rp->SAL_version == 1) {
 188                 /* SAL_version 1 didn't set the nasids_size field */
 189                 rp->nasids_size = 128;
 190         }
 191         xp_nasid_mask_bytes = rp->nasids_size;
 192         xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
 193
 194         /* setup the pointers to the various items in the reserved page */
 195         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
 196         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
 197         xpc_vars = XPC_RP_VARS(rp);
 198         xpc_vars_part = XPC_RP_VARS_PART(rp);
 199
 200         /*
 201          * Before clearing xpc_vars, see if a page of AMOs had been previously
 202          * allocated. If not we'll need to allocate one and set permissions
 203          * so that cross-partition AMOs are allowed.
 204          *
 205          * The allocated AMO page needs MCA reporting to remain disabled after
 206          * XPC has unloaded.  To make this work, we keep a copy of the pointer
 207          * to this page (i.e., amos_page) in the struct xpc_vars structure,
 208          * which is pointed to by the reserved page, and re-use that saved copy
 209          * on subsequent loads of XPC. This AMO page is never freed, and its
 210          * memory protections are never restricted.
 211          */
 212         amos_page = xpc_vars->amos_page;
 213         if (amos_page == NULL) {
 214                 amos_page = (AMO_t *)TO_AMO(uncached_alloc_page(0));
 215                 if (amos_page == NULL) {
 216                         dev_err(xpc_part, "can't allocate page of AMOs\n");
 217                         return NULL;
 218                 }
 219
 220                 /*
 221                  * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
 222                  * when xpc_allow_IPI_ops() is called via xpc_hb_init().
 223                  */
 224                 if (!enable_shub_wars_1_1()) {
 225                         ret = sn_change_memprotect(ia64_tpa((u64)amos_page),
 226                                                    PAGE_SIZE,
 227                                                    SN_MEMPROT_ACCESS_CLASS_1,
 228                                                    &nasid_array);
 229                         if (ret != 0) {
 230                                 dev_err(xpc_part, "can't change memory "
 231                                         "protections\n");
 232                                 uncached_free_page(__IA64_UNCACHED_OFFSET |
 233                                                    TO_PHYS((u64)amos_page));
 234                                 return NULL;
 235                         }
 236                 }
 237         } else if (!IS_AMO_ADDRESS((u64)amos_page)) {
 238                 /*
 239                  * EFI's XPBOOT can also set amos_page in the reserved page,
 240                  * but it happens to leave it as an uncached physical address
 241                  * and we need it to be an uncached virtual, so we'll have to
 242                  * convert it.
 243                  */
 244                 if (!IS_AMO_PHYS_ADDRESS((u64)amos_page)) {
 245                         dev_err(xpc_part, "previously used amos_page address "
 246                                 "is bad = 0x%p\n", (void *)amos_page);
 247                         return NULL;
 248                 }
 249                 amos_page = (AMO_t *)TO_AMO((u64)amos_page);
 250         }
 251
 252         /* clear xpc_vars */
 253         memset(xpc_vars, 0, sizeof(struct xpc_vars));
 254
 255         xpc_vars->version = XPC_V_VERSION;
 256         xpc_vars->act_nasid = cpuid_to_nasid(0);
 257         xpc_vars->act_phys_cpuid = cpu_physical_id(0);
 258         xpc_vars->vars_part_pa = __pa(xpc_vars_part);
 259         xpc_vars->amos_page_pa = ia64_tpa((u64)amos_page);
 260         xpc_vars->amos_page = amos_page;        /* save for next load of XPC */
 261
 262         /* clear xpc_vars_part */
 263         memset((u64 *)xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
 264                XP_MAX_PARTITIONS);
 265
 266         /* initialize the activate IRQ related AMO variables */
 267         for (i = 0; i < xp_nasid_mask_words; i++)
 268                 (void)xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
 269
 270         /* initialize the engaged remote partitions related AMO variables */
 271         (void)xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
 272         (void)xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
 273
 274         /* timestamp of when reserved page was setup by XPC */
 275         rp->stamp = CURRENT_TIME;
 276
 277         /*
 278          * This signifies to the remote partition that our reserved
 279          * page is initialized.
 280          */
 281         rp->vars_pa = __pa(xpc_vars);
 282
 283         return rp;
 284 }
 285
 286 /*
 287  * Change protections to allow IPI operations (and AMO operations on
 288  * Shub 1.1 systems).
 289  */
 290 void
 291 xpc_allow_IPI_ops(void)
 292 {
 293         int node;
 294         int nasid;
 295
 296         /* >>> Change SH_IPI_ACCESS code to use SAL call once it is available */
 297
 298         if (is_shub2()) {
 299                 xpc_sh2_IPI_access0 =
 300                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
 301                 xpc_sh2_IPI_access1 =
 302                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
 303                 xpc_sh2_IPI_access2 =
 304                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
 305                 xpc_sh2_IPI_access3 =
 306                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
 307
 308                 for_each_online_node(node) {
 309                         nasid = cnodeid_to_nasid(node);
 310                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
 311                               -1UL);
 312                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
 313                               -1UL);
 314                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
 315                               -1UL);
 316                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
 317                               -1UL);
 318                 }
 319
 320         } else {
 321                 xpc_sh1_IPI_access =
 322                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
 323
 324                 for_each_online_node(node) {
 325                         nasid = cnodeid_to_nasid(node);
 326                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
 327                               -1UL);
 328
 329                         /*
 330                          * Since the BIST collides with memory operations on
 331                          * SHUB 1.1 sn_change_memprotect() cannot be used.
 332                          */
 333                         if (enable_shub_wars_1_1()) {
 334                                 /* open up everything */
 335                                 xpc_prot_vec[node] = (u64)HUB_L((u64 *)
 336                                                                 GLOBAL_MMR_ADDR
 337                                                                 (nasid,
 338                                                   SH1_MD_DQLP_MMR_DIR_PRIVEC0));
 339                                 HUB_S((u64 *)
 340                                       GLOBAL_MMR_ADDR(nasid,
 341                                                    SH1_MD_DQLP_MMR_DIR_PRIVEC0),
 342                                       -1UL);
 343                                 HUB_S((u64 *)
 344                                       GLOBAL_MMR_ADDR(nasid,
 345                                                    SH1_MD_DQRP_MMR_DIR_PRIVEC0),
 346                                       -1UL);
 347                         }
 348                 }
 349         }
 350 }
 351
 352 /*
 353  * Restrict protections to disallow IPI operations (and AMO operations on
 354  * Shub 1.1 systems).
 355  */
 356 void
 357 xpc_restrict_IPI_ops(void)
 358 {
 359         int node;
 360         int nasid;
 361
 362         /* >>> Change SH_IPI_ACCESS code to use SAL call once it is available */
 363
 364         if (is_shub2()) {
 365
 366                 for_each_online_node(node) {
 367                         nasid = cnodeid_to_nasid(node);
 368                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
 369                               xpc_sh2_IPI_access0);
 370                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
 371                               xpc_sh2_IPI_access1);
 372                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
 373                               xpc_sh2_IPI_access2);
 374                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
 375                               xpc_sh2_IPI_access3);
 376                 }
 377
 378         } else {
 379
 380                 for_each_online_node(node) {
 381                         nasid = cnodeid_to_nasid(node);
 382                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
 383                               xpc_sh1_IPI_access);
 384
 385                         if (enable_shub_wars_1_1()) {
 386                                 HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
 387                                                    SH1_MD_DQLP_MMR_DIR_PRIVEC0),
 388                                       xpc_prot_vec[node]);
 389                                 HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
 390                                                    SH1_MD_DQRP_MMR_DIR_PRIVEC0),
 391                                       xpc_prot_vec[node]);
 392                         }
 393                 }
 394         }
 395 }
 396
 397 /*
 398  * At periodic intervals, scan through all active partitions and ensure
 399  * their heartbeat is still active.  If not, the partition is deactivated.
 400  */
 401 void
 402 xpc_check_remote_hb(void)
 403 {
 404         struct xpc_vars *remote_vars;
 405         struct xpc_partition *part;
 406         partid_t partid;
 407         bte_result_t bres;
 408
 409         remote_vars = (struct xpc_vars *)xpc_remote_copy_buffer;
 410
 411         for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
 412
 413                 if (xpc_exiting)
 414                         break;
 415
 416                 if (partid == sn_partition_id)
 417                         continue;
 418
 419                 part = &xpc_partitions[partid];
 420
 421                 if (part->act_state == XPC_P_INACTIVE ||
 422                     part->act_state == XPC_P_DEACTIVATING) {
 423                         continue;
 424                 }
 425
 426                 /* pull the remote_hb cache line */
 427                 bres = xp_bte_copy(part->remote_vars_pa,
 428                                    (u64)remote_vars,
 429                                    XPC_RP_VARS_SIZE,
 430                                    (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 431                 if (bres != BTE_SUCCESS) {
 432                         XPC_DEACTIVATE_PARTITION(part,
 433                                                  xpc_map_bte_errors(bres));
 434                         continue;
 435                 }
 436
 437                 dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
 438                         " = %ld, heartbeat_offline = %ld, HB_mask = 0x%lx\n",
 439                         partid, remote_vars->heartbeat, part->last_heartbeat,
 440                         remote_vars->heartbeat_offline,
 441                         remote_vars->heartbeating_to_mask);
 442
 443                 if (((remote_vars->heartbeat == part->last_heartbeat) &&
 444                      (remote_vars->heartbeat_offline == 0)) ||
 445                     !xpc_hb_allowed(sn_partition_id, remote_vars)) {
 446
 447                         XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
 448                         continue;
 449                 }
 450
 451                 part->last_heartbeat = remote_vars->heartbeat;
 452         }
 453 }
 454
 455 /*
 456  * Get a copy of a portion of the remote partition's rsvd page.
 457  *
 458  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
 459  * is large enough to contain a copy of their reserved page header and
 460  * part_nasids mask.
 461  */
 462 static enum xpc_retval
 463 xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 464                   struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
 465 {
 466         int bres, i;
 467
 468         /* get the reserved page's physical address */
 469
 470         *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
 471         if (*remote_rp_pa == 0)
 472                 return xpcNoRsvdPageAddr;
 473
 474         /* pull over the reserved page header and part_nasids mask */
 475         bres = xp_bte_copy(*remote_rp_pa, (u64)remote_rp,
 476                            XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes,
 477                            (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 478         if (bres != BTE_SUCCESS)
 479                 return xpc_map_bte_errors(bres);
 480
 481         if (discovered_nasids != NULL) {
 482                 u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
 483
 484                 for (i = 0; i < xp_nasid_mask_words; i++)
 485                         discovered_nasids[i] |= remote_part_nasids[i];
 486         }
 487
 488         /* check that the partid is for another partition */
 489
 490         if (remote_rp->partid < 1 ||
 491             remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
 492                 return xpcInvalidPartid;
 493         }
 494
 495         if (remote_rp->partid == sn_partition_id)
 496                 return xpcLocalPartid;
 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  * Get a copy of the remote partition's XPC variables from the reserved page.
 508  *
 509  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
 510  * assumed to be of size XPC_RP_VARS_SIZE.
 511  */
 512 static enum xpc_retval
 513 xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
 514 {
 515         int bres;
 516
 517         if (remote_vars_pa == 0)
 518                 return xpcVarsNotSet;
 519
 520         /* pull over the cross partition variables */
 521         bres = xp_bte_copy(remote_vars_pa, (u64)remote_vars, XPC_RP_VARS_SIZE,
 522                            (BTE_NOTIFY | BTE_WACQUIRE), NULL);
 523         if (bres != BTE_SUCCESS)
 524                 return xpc_map_bte_errors(bres);
 525
 526         if (XPC_VERSION_MAJOR(remote_vars->version) !=
 527             XPC_VERSION_MAJOR(XPC_V_VERSION)) {
 528                 return xpcBadVersion;
 529         }
 530
 531         return xpcSuccess;
 532 }
 533
 534 /*
 535  * Update the remote partition's info.
 536  */
 537 static void
 538 xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
 539                           struct timespec *remote_rp_stamp, u64 remote_rp_pa,
 540                           u64 remote_vars_pa, struct xpc_vars *remote_vars)
 541 {
 542         part->remote_rp_version = remote_rp_version;
 543         dev_dbg(xpc_part, "  remote_rp_version = 0x%016x\n",
 544                 part->remote_rp_version);
 545
 546         part->remote_rp_stamp = *remote_rp_stamp;
 547         dev_dbg(xpc_part, "  remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
 548                 part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
 549
 550         part->remote_rp_pa = remote_rp_pa;
 551         dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
 552
 553         part->remote_vars_pa = remote_vars_pa;
 554         dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
 555                 part->remote_vars_pa);
 556
 557         part->last_heartbeat = remote_vars->heartbeat;
 558         dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
 559                 part->last_heartbeat);
 560
 561         part->remote_vars_part_pa = remote_vars->vars_part_pa;
 562         dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
 563                 part->remote_vars_part_pa);
 564
 565         part->remote_act_nasid = remote_vars->act_nasid;
 566         dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
 567                 part->remote_act_nasid);
 568
 569         part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
 570         dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
 571                 part->remote_act_phys_cpuid);
 572
 573         part->remote_amos_page_pa = remote_vars->amos_page_pa;
 574         dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
 575                 part->remote_amos_page_pa);
 576
 577         part->remote_vars_version = remote_vars->version;
 578         dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
 579                 part->remote_vars_version);
 580 }
 581
 582 /*
 583  * Prior code has determined the nasid which generated an IPI.  Inspect
 584  * that nasid to determine if its partition needs to be activated or
 585  * deactivated.
 586  *
 587  * A partition is consider "awaiting activation" if our partition
 588  * flags indicate it is not active and it has a heartbeat.  A
 589  * partition is considered "awaiting deactivation" if our partition
 590  * flags indicate it is active but it has no heartbeat or it is not
 591  * sending its heartbeat to us.
 592  *
 593  * To determine the heartbeat, the remote nasid must have a properly
 594  * initialized reserved page.
 595  */
 596 static void
 597 xpc_identify_act_IRQ_req(int nasid)
 598 {
 599         struct xpc_rsvd_page *remote_rp;
 600         struct xpc_vars *remote_vars;
 601         u64 remote_rp_pa;
 602         u64 remote_vars_pa;
 603         int remote_rp_version;
 604         int reactivate = 0;
 605         int stamp_diff;
 606         struct timespec remote_rp_stamp = { 0, 0 };
 607         partid_t partid;
 608         struct xpc_partition *part;
 609         enum xpc_retval ret;
 610
 611         /* pull over the reserved page structure */
 612
 613         remote_rp = (struct xpc_rsvd_page *)xpc_remote_copy_buffer;
 614
 615         ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
 616         if (ret != xpcSuccess) {
 617                 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
 618                          "which sent interrupt, reason=%d\n", nasid, ret);
 619                 return;
 620         }
 621
 622         remote_vars_pa = remote_rp->vars_pa;
 623         remote_rp_version = remote_rp->version;
 624         if (XPC_SUPPORTS_RP_STAMP(remote_rp_version))
 625                 remote_rp_stamp = remote_rp->stamp;
 626
 627         partid = remote_rp->partid;
 628         part = &xpc_partitions[partid];
 629
 630         /* pull over the cross partition variables */
 631
 632         remote_vars = (struct xpc_vars *)xpc_remote_copy_buffer;
 633
 634         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
 635         if (ret != xpcSuccess) {
 636
 637                 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
 638                          "which sent interrupt, reason=%d\n", nasid, ret);
 639
 640                 XPC_DEACTIVATE_PARTITION(part, ret);
 641                 return;
 642         }
 643
 644         part->act_IRQ_rcvd++;
 645
 646         dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
 647                 "%ld:0x%lx\n", (int)nasid, (int)partid, part->act_IRQ_rcvd,
 648                 remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
 649
 650         if (xpc_partition_disengaged(part) &&
 651             part->act_state == XPC_P_INACTIVE) {
 652
 653                 xpc_update_partition_info(part, remote_rp_version,
 654                                           &remote_rp_stamp, remote_rp_pa,
 655                                           remote_vars_pa, remote_vars);
 656
 657                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 658                         if (xpc_partition_disengage_requested(1UL << partid)) {
 659                                 /*
 660                                  * Other side is waiting on us to disengage,
 661                                  * even though we already have.
 662                                  */
 663                                 return;
 664                         }
 665                 } else {
 666                         /* other side doesn't support disengage requests */
 667                         xpc_clear_partition_disengage_request(1UL << partid);
 668                 }
 669
 670                 xpc_activate_partition(part);
 671                 return;
 672         }
 673
 674         DBUG_ON(part->remote_rp_version == 0);
 675         DBUG_ON(part->remote_vars_version == 0);
 676
 677         if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
 678                 DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
 679                                                        remote_vars_version));
 680
 681                 if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 682                         DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
 683                                                                version));
 684                         /* see if the other side rebooted */
 685                         if (part->remote_amos_page_pa ==
 686                             remote_vars->amos_page_pa &&
 687                             xpc_hb_allowed(sn_partition_id, remote_vars)) {
 688                                 /* doesn't look that way, so ignore the IPI */
 689                                 return;
 690                         }
 691                 }
 692
 693                 /*
 694                  * Other side rebooted and previous XPC didn't support the
 695                  * disengage request, so we don't need to do anything special.
 696                  */
 697
 698                 xpc_update_partition_info(part, remote_rp_version,
 699                                           &remote_rp_stamp, remote_rp_pa,
 700                                           remote_vars_pa, remote_vars);
 701                 part->reactivate_nasid = nasid;
 702                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
 703                 return;
 704         }
 705
 706         DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
 707
 708         if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 709                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 710
 711                 /*
 712                  * Other side rebooted and previous XPC did support the
 713                  * disengage request, but the new one doesn't.
 714                  */
 715
 716                 xpc_clear_partition_engaged(1UL << partid);
 717                 xpc_clear_partition_disengage_request(1UL << partid);
 718
 719                 xpc_update_partition_info(part, remote_rp_version,
 720                                           &remote_rp_stamp, remote_rp_pa,
 721                                           remote_vars_pa, remote_vars);
 722                 reactivate = 1;
 723
 724         } else {
 725                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 726
 727                 stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
 728                                                 &remote_rp_stamp);
 729                 if (stamp_diff != 0) {
 730                         DBUG_ON(stamp_diff >= 0);
 731
 732                         /*
 733                          * Other side rebooted and the previous XPC did support
 734                          * the disengage request, as does the new one.
 735                          */
 736
 737                         DBUG_ON(xpc_partition_engaged(1UL << partid));
 738                         DBUG_ON(xpc_partition_disengage_requested(1UL <<
 739                                                                   partid));
 740
 741                         xpc_update_partition_info(part, remote_rp_version,
 742                                                   &remote_rp_stamp,
 743                                                   remote_rp_pa, remote_vars_pa,
 744                                                   remote_vars);
 745                         reactivate = 1;
 746                 }
 747         }
 748
 749         if (part->disengage_request_timeout > 0 &&
 750             !xpc_partition_disengaged(part)) {
 751                 /* still waiting on other side to disengage from us */
 752                 return;
 753         }
 754
 755         if (reactivate) {
 756                 part->reactivate_nasid = nasid;
 757                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
 758
 759         } else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
 760                    xpc_partition_disengage_requested(1UL << partid)) {
 761                 XPC_DEACTIVATE_PARTITION(part, xpcOtherGoingDown);
 762         }
 763 }
 764
 765 /*
 766  * Loop through the activation AMO variables and process any bits
 767  * which are set.  Each bit indicates a nasid sending a partition
 768  * activation or deactivation request.
 769  *
 770  * Return #of IRQs detected.
 771  */
 772 int
 773 xpc_identify_act_IRQ_sender(void)
 774 {
 775         int word, bit;
 776         u64 nasid_mask;
 777         u64 nasid;              /* remote nasid */
 778         int n_IRQs_detected = 0;
 779         AMO_t *act_amos;
 780
 781         act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
 782
 783         /* scan through act AMO variable looking for non-zero entries */
 784         for (word = 0; word < xp_nasid_mask_words; word++) {
 785
 786                 if (xpc_exiting)
 787                         break;
 788
 789                 nasid_mask = xpc_IPI_receive(&act_amos[word]);
 790                 if (nasid_mask == 0) {
 791                         /* no IRQs from nasids in this variable */
 792                         continue;
 793                 }
 794
 795                 dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
 796                         nasid_mask);
 797
 798                 /*
 799                  * If this nasid has been added to the machine since
 800                  * our partition was reset, this will retain the
 801                  * remote nasid in our reserved pages machine mask.
 802                  * This is used in the event of module reload.
 803                  */
 804                 xpc_mach_nasids[word] |= nasid_mask;
 805
 806                 /* locate the nasid(s) which sent interrupts */
 807
 808                 for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
 809                         if (nasid_mask & (1UL << bit)) {
 810                                 n_IRQs_detected++;
 811                                 nasid = XPC_NASID_FROM_W_B(word, bit);
 812                                 dev_dbg(xpc_part, "interrupt from nasid %ld\n",
 813                                         nasid);
 814                                 xpc_identify_act_IRQ_req(nasid);
 815                         }
 816                 }
 817         }
 818         return n_IRQs_detected;
 819 }
 820
 821 /*
 822  * See if the other side has responded to a partition disengage request
 823  * from us.
 824  */
 825 int
 826 xpc_partition_disengaged(struct xpc_partition *part)
 827 {
 828         partid_t partid = XPC_PARTID(part);
 829         int disengaged;
 830
 831         disengaged = (xpc_partition_engaged(1UL << partid) == 0);
 832         if (part->disengage_request_timeout) {
 833                 if (!disengaged) {
 834                         if (time_before(jiffies,
 835                             part->disengage_request_timeout)) {
 836                                 /* timelimit hasn't been reached yet */
 837                                 return 0;
 838                         }
 839
 840                         /*
 841                          * Other side hasn't responded to our disengage
 842                          * request in a timely fashion, so assume it's dead.
 843                          */
 844
 845                         dev_info(xpc_part, "disengage from remote partition %d "
 846                                  "timed out\n", partid);
 847                         xpc_disengage_request_timedout = 1;
 848                         xpc_clear_partition_engaged(1UL << partid);
 849                         disengaged = 1;
 850                 }
 851                 part->disengage_request_timeout = 0;
 852
 853                 /* cancel the timer function, provided it's not us */
 854                 if (!in_interrupt()) {
 855                         del_singleshot_timer_sync(&part->
 856                                                   disengage_request_timer);
 857                 }
 858
 859                 DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
 860                         part->act_state != XPC_P_INACTIVE);
 861                 if (part->act_state != XPC_P_INACTIVE)
 862                         xpc_wakeup_channel_mgr(part);
 863
 864                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version))
 865                         xpc_cancel_partition_disengage_request(part);
 866         }
 867         return disengaged;
 868 }
 869
 870 /*
 871  * Mark specified partition as active.
 872  */
 873 enum xpc_retval
 874 xpc_mark_partition_active(struct xpc_partition *part)
 875 {
 876         unsigned long irq_flags;
 877         enum xpc_retval ret;
 878
 879         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
 880
 881         spin_lock_irqsave(&part->act_lock, irq_flags);
 882         if (part->act_state == XPC_P_ACTIVATING) {
 883                 part->act_state = XPC_P_ACTIVE;
 884                 ret = xpcSuccess;
 885         } else {
 886                 DBUG_ON(part->reason == xpcSuccess);
 887                 ret = part->reason;
 888         }
 889         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 890
 891         return ret;
 892 }
 893
 894 /*
 895  * Notify XPC that the partition is down.
 896  */
 897 void
 898 xpc_deactivate_partition(const int line, struct xpc_partition *part,
 899                          enum xpc_retval reason)
 900 {
 901         unsigned long irq_flags;
 902
 903         spin_lock_irqsave(&part->act_lock, irq_flags);
 904
 905         if (part->act_state == XPC_P_INACTIVE) {
 906                 XPC_SET_REASON(part, reason, line);
 907                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 908                 if (reason == xpcReactivating) {
 909                         /* we interrupt ourselves to reactivate partition */
 910                         xpc_IPI_send_reactivate(part);
 911                 }
 912                 return;
 913         }
 914         if (part->act_state == XPC_P_DEACTIVATING) {
 915                 if ((part->reason == xpcUnloading && reason != xpcUnloading) ||
 916                     reason == xpcReactivating) {
 917                         XPC_SET_REASON(part, reason, line);
 918                 }
 919                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 920                 return;
 921         }
 922
 923         part->act_state = XPC_P_DEACTIVATING;
 924         XPC_SET_REASON(part, reason, line);
 925
 926         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 927
 928         if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 929                 xpc_request_partition_disengage(part);
 930                 xpc_IPI_send_disengage(part);
 931
 932                 /* set a timelimit on the disengage request */
 933                 part->disengage_request_timeout = jiffies +
 934                     (xpc_disengage_request_timelimit * HZ);
 935                 part->disengage_request_timer.expires =
 936                     part->disengage_request_timeout;
 937                 add_timer(&part->disengage_request_timer);
 938         }
 939
 940         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
 941                 XPC_PARTID(part), reason);
 942
 943         xpc_partition_going_down(part, reason);
 944 }
 945
 946 /*
 947  * Mark specified partition as inactive.
 948  */
 949 void
 950 xpc_mark_partition_inactive(struct xpc_partition *part)
 951 {
 952         unsigned long irq_flags;
 953
 954         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
 955                 XPC_PARTID(part));
 956
 957         spin_lock_irqsave(&part->act_lock, irq_flags);
 958         part->act_state = XPC_P_INACTIVE;
 959         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 960         part->remote_rp_pa = 0;
 961 }
 962
 963 /*
 964  * SAL has provided a partition and machine mask.  The partition mask
 965  * contains a bit for each even nasid in our partition.  The machine
 966  * mask contains a bit for each even nasid in the entire machine.
 967  *
 968  * Using those two bit arrays, we can determine which nasids are
 969  * known in the machine.  Each should also have a reserved page
 970  * initialized if they are available for partitioning.
 971  */
 972 void
 973 xpc_discovery(void)
 974 {
 975         void *remote_rp_base;
 976         struct xpc_rsvd_page *remote_rp;
 977         struct xpc_vars *remote_vars;
 978         u64 remote_rp_pa;
 979         u64 remote_vars_pa;
 980         int region;
 981         int region_size;
 982         int max_regions;
 983         int nasid;
 984         struct xpc_rsvd_page *rp;
 985         partid_t partid;
 986         struct xpc_partition *part;
 987         u64 *discovered_nasids;
 988         enum xpc_retval ret;
 989
 990         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
 991                                                   xp_nasid_mask_bytes,
 992                                                   GFP_KERNEL, &remote_rp_base);
 993         if (remote_rp == NULL)
 994                 return;
 995
 996         remote_vars = (struct xpc_vars *)remote_rp;
 997
 998         discovered_nasids = kzalloc(sizeof(u64) * xp_nasid_mask_words,
 999                                     GFP_KERNEL);
1000         if (discovered_nasids == NULL) {
1001                 kfree(remote_rp_base);
1002                 return;
1003         }
1004
1005         rp = (struct xpc_rsvd_page *)xpc_rsvd_page;
1006
1007         /*
1008          * The term 'region' in this context refers to the minimum number of
1009          * nodes that can comprise an access protection grouping. The access
1010          * protection is in regards to memory, IOI and IPI.
1011          */
1012         max_regions = 64;
1013         region_size = sn_region_size;
1014
1015         switch (region_size) {
1016         case 128:
1017                 max_regions *= 2;
1018         case 64:
1019                 max_regions *= 2;
1020         case 32:
1021                 max_regions *= 2;
1022                 region_size = 16;
1023                 DBUG_ON(!is_shub2());
1024         }
1025
1026         for (region = 0; region < max_regions; region++) {
1027
1028                 if (xpc_exiting)
1029                         break;
1030
1031                 dev_dbg(xpc_part, "searching region %d\n", region);
1032
1033                 for (nasid = (region * region_size * 2);
1034                      nasid < ((region + 1) * region_size * 2); nasid += 2) {
1035
1036                         if (xpc_exiting)
1037                                 break;
1038
1039                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
1040
1041                         if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
1042                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
1043                                         "part of the local partition; skipping "
1044                                         "region\n", nasid);
1045                                 break;
1046                         }
1047
1048                         if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
1049                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
1050                                         "not on Numa-Link network at reset\n",
1051                                         nasid);
1052                                 continue;
1053                         }
1054
1055                         if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
1056                                 dev_dbg(xpc_part, "Nasid %d is part of a "
1057                                         "partition which was previously "
1058                                         "discovered\n", nasid);
1059                                 continue;
1060                         }
1061
1062                         /* pull over the reserved page structure */
1063
1064                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
1065                                                 remote_rp, &remote_rp_pa);
1066                         if (ret != xpcSuccess) {
1067                                 dev_dbg(xpc_part, "unable to get reserved page "
1068                                         "from nasid %d, reason=%d\n", nasid,
1069                                         ret);
1070
1071                                 if (ret == xpcLocalPartid)
1072                                         break;
1073
1074                                 continue;
1075                         }
1076
1077                         remote_vars_pa = remote_rp->vars_pa;
1078
1079                         partid = remote_rp->partid;
1080                         part = &xpc_partitions[partid];
1081
1082                         /* pull over the cross partition variables */
1083
1084                         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
1085                         if (ret != xpcSuccess) {
1086                                 dev_dbg(xpc_part, "unable to get XPC variables "
1087                                         "from nasid %d, reason=%d\n", nasid,
1088                                         ret);
1089
1090                                 XPC_DEACTIVATE_PARTITION(part, ret);
1091                                 continue;
1092                         }
1093
1094                         if (part->act_state != XPC_P_INACTIVE) {
1095                                 dev_dbg(xpc_part, "partition %d on nasid %d is "
1096                                         "already activating\n", partid, nasid);
1097                                 break;
1098                         }
1099
1100                         /*
1101                          * Register the remote partition's AMOs with SAL so it
1102                          * can handle and cleanup errors within that address
1103                          * range should the remote partition go down. We don't
1104                          * unregister this range because it is difficult to
1105                          * tell when outstanding writes to the remote partition
1106                          * are finished and thus when it is thus safe to
1107                          * unregister. This should not result in wasted space
1108                          * in the SAL xp_addr_region table because we should
1109                          * get the same page for remote_act_amos_pa after
1110                          * module reloads and system reboots.
1111                          */
1112                         if (sn_register_xp_addr_region
1113                             (remote_vars->amos_page_pa, PAGE_SIZE, 1) < 0) {
1114                                 dev_dbg(xpc_part,
1115                                         "partition %d failed to "
1116                                         "register xp_addr region 0x%016lx\n",
1117                                         partid, remote_vars->amos_page_pa);
1118
1119                                 XPC_SET_REASON(part, xpcPhysAddrRegFailed,
1120                                                __LINE__);
1121                                 break;
1122                         }
1123
1124                         /*
1125                          * The remote nasid is valid and available.
1126                          * Send an interrupt to that nasid to notify
1127                          * it that we are ready to begin activation.
1128                          */
1129                         dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
1130                                 "nasid %d, phys_cpuid 0x%x\n",
1131                                 remote_vars->amos_page_pa,
1132                                 remote_vars->act_nasid,
1133                                 remote_vars->act_phys_cpuid);
1134
1135                         if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
1136                                                            version)) {
1137                                 part->remote_amos_page_pa =
1138                                     remote_vars->amos_page_pa;
1139                                 xpc_mark_partition_disengaged(part);
1140                                 xpc_cancel_partition_disengage_request(part);
1141                         }
1142                         xpc_IPI_send_activate(remote_vars);
1143                 }
1144         }
1145
1146         kfree(discovered_nasids);
1147         kfree(remote_rp_base);
1148 }
1149
1150 /*
1151  * Given a partid, get the nasids owned by that partition from the
1152  * remote partition's reserved page.
1153  */
1154 enum xpc_retval
1155 xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
1156 {
1157         struct xpc_partition *part;
1158         u64 part_nasid_pa;
1159         int bte_res;
1160
1161         part = &xpc_partitions[partid];
1162         if (part->remote_rp_pa == 0)
1163                 return xpcPartitionDown;
1164
1165         memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
1166
1167         part_nasid_pa = (u64)XPC_RP_PART_NASIDS(part->remote_rp_pa);
1168
1169         bte_res = xp_bte_copy(part_nasid_pa, (u64)nasid_mask,
1170                               xp_nasid_mask_bytes, (BTE_NOTIFY | BTE_WACQUIRE),
1171                               NULL);
1172
1173         return xpc_map_bte_errors(bte_res);
1174 }