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/sn/intr.h>
  24 #include <asm/sn/sn_sal.h>
  25 #include <asm/sn/nodepda.h>
  26 #include <asm/sn/addrs.h>
  27 #include "xpc.h"
  28
  29 /* XPC is exiting flag */
  30 int xpc_exiting;
  31
  32 /* SH_IPI_ACCESS shub register value on startup */
  33 static u64 xpc_sh1_IPI_access;
  34 static u64 xpc_sh2_IPI_access0;
  35 static u64 xpc_sh2_IPI_access1;
  36 static u64 xpc_sh2_IPI_access2;
  37 static u64 xpc_sh2_IPI_access3;
  38
  39 /* original protection values for each node */
  40 u64 xpc_prot_vec[MAX_NUMNODES];
  41
  42 /* this partition's reserved page pointers */
  43 struct xpc_rsvd_page *xpc_rsvd_page;
  44 static u64 *xpc_part_nasids;
  45 static u64 *xpc_mach_nasids;
  46
  47 /* >>> next two variables should be 'xpc_' if they remain here */
  48 static int xp_sizeof_nasid_mask;        /* actual size in bytes of nasid mask */
  49 int xp_nasid_mask_words;        /* actual size in words of nasid mask */
  50
  51 struct xpc_partition *xpc_partitions;
  52
  53 /*
  54  * Generic buffer used to store a local copy of portions of a remote
  55  * partition's reserved page (either its header and part_nasids mask,
  56  * or its vars).
  57  */
  58 char *xpc_remote_copy_buffer;
  59 void *xpc_remote_copy_buffer_base;
  60
  61 /*
  62  * Guarantee that the kmalloc'd memory is cacheline aligned.
  63  */
  64 void *
  65 xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
  66 {
  67         /* see if kmalloc will give us cachline aligned memory by default */
  68         *base = kmalloc(size, flags);
  69         if (*base == NULL)
  70                 return NULL;
  71
  72         if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
  73                 return *base;
  74
  75         kfree(*base);
  76
  77         /* nope, we'll have to do it ourselves */
  78         *base = kmalloc(size + L1_CACHE_BYTES, flags);
  79         if (*base == NULL)
  80                 return NULL;
  81
  82         return (void *)L1_CACHE_ALIGN((u64)*base);
  83 }
  84
  85 /*
  86  * Given a nasid, get the physical address of the  partition's reserved page
  87  * for that nasid. This function returns 0 on any error.
  88  */
  89 static u64
  90 xpc_get_rsvd_page_pa(int nasid)
  91 {
  92         enum xp_retval ret;
  93         s64 status;
  94         u64 cookie = 0;
  95         u64 rp_pa = nasid;      /* seed with nasid */
  96         u64 len = 0;
  97         u64 buf = buf;
  98         u64 buf_len = 0;
  99         void *buf_base = NULL;
 100
 101         while (1) {
 102
 103                 status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
 104                                                        &len);
 105
 106                 dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
 107                         "0x%016lx, address=0x%016lx, len=0x%016lx\n",
 108                         status, cookie, rp_pa, len);
 109
 110                 if (status != SALRET_MORE_PASSES)
 111                         break;
 112
 113                 /* >>> L1_CACHE_ALIGN() is only a sn2-bte_copy requirement */
 114                 if (L1_CACHE_ALIGN(len) > buf_len) {
 115                         kfree(buf_base);
 116                         buf_len = L1_CACHE_ALIGN(len);
 117                         buf = (u64)xpc_kmalloc_cacheline_aligned(buf_len,
 118                                                                  GFP_KERNEL,
 119                                                                  &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                 ret = xp_remote_memcpy((void *)buf, (void *)rp_pa, buf_len);
 129                 if (ret != xpSuccess) {
 130                         dev_dbg(xpc_part, "xp_remote_memcpy failed %d\n", ret);
 131                         status = SALRET_ERROR;
 132                         break;
 133                 }
 134         }
 135
 136         kfree(buf_base);
 137
 138         if (status != SALRET_OK)
 139                 rp_pa = 0;
 140
 141         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
 142         return rp_pa;
 143 }
 144
 145 /*
 146  * Fill the partition reserved page with the information needed by
 147  * other partitions to discover we are alive and establish initial
 148  * communications.
 149  */
 150 struct xpc_rsvd_page *
 151 xpc_setup_rsvd_page(void)
 152 {
 153         struct xpc_rsvd_page *rp;
 154         u64 rp_pa;
 155
 156         /* get the local reserved page's address */
 157
 158         preempt_disable();
 159         rp_pa = xpc_get_rsvd_page_pa(cpuid_to_nasid(smp_processor_id()));
 160         preempt_enable();
 161         if (rp_pa == 0) {
 162                 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
 163                 return NULL;
 164         }
 165         rp = (struct xpc_rsvd_page *)__va(rp_pa);
 166
 167         if (rp->SAL_version < 3) {
 168                 /* SAL_versions < 3 had a SAL_partid defined as a u8 */
 169                 rp->SAL_partid &= 0xff;
 170         }
 171         BUG_ON(rp->SAL_partid != sn_partition_id);
 172
 173         if (rp->SAL_partid < 0 || rp->SAL_partid >= xp_max_npartitions) {
 174                 dev_err(xpc_part, "the reserved page's partid of %d is outside "
 175                         "supported range (< 0 || >= %d)\n", rp->SAL_partid,
 176                         xp_max_npartitions);
 177                 return NULL;
 178         }
 179
 180         rp->version = XPC_RP_VERSION;
 181         rp->max_npartitions = xp_max_npartitions;
 182
 183         /* establish the actual sizes of the nasid masks */
 184         if (rp->SAL_version == 1) {
 185                 /* SAL_version 1 didn't set the nasids_size field */
 186                 rp->SAL_nasids_size = 128;
 187         }
 188         xp_sizeof_nasid_mask = rp->SAL_nasids_size;
 189         xp_nasid_mask_words = DIV_ROUND_UP(xp_sizeof_nasid_mask,
 190                                            BYTES_PER_WORD);
 191
 192         /* setup the pointers to the various items in the reserved page */
 193         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
 194         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
 195
 196         if (xpc_rsvd_page_init(rp) != xpSuccess)
 197                 return NULL;
 198
 199         /*
 200          * Set timestamp of when reserved page was setup by XPC.
 201          * This signifies to the remote partition that our reserved
 202          * page is initialized.
 203          */
 204         rp->stamp = CURRENT_TIME;
 205
 206         return rp;
 207 }
 208
 209 /*
 210  * Change protections to allow IPI operations (and AMO operations on
 211  * Shub 1.1 systems).
 212  */
 213 void
 214 xpc_allow_IPI_ops(void)
 215 {
 216         int node;
 217         int nasid;
 218
 219         /* >>> Change SH_IPI_ACCESS code to use SAL call once it is available */
 220
 221         if (is_shub2()) {
 222                 xpc_sh2_IPI_access0 =
 223                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
 224                 xpc_sh2_IPI_access1 =
 225                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
 226                 xpc_sh2_IPI_access2 =
 227                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
 228                 xpc_sh2_IPI_access3 =
 229                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
 230
 231                 for_each_online_node(node) {
 232                         nasid = cnodeid_to_nasid(node);
 233                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
 234                               -1UL);
 235                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
 236                               -1UL);
 237                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
 238                               -1UL);
 239                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
 240                               -1UL);
 241                 }
 242
 243         } else {
 244                 xpc_sh1_IPI_access =
 245                     (u64)HUB_L((u64 *)LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
 246
 247                 for_each_online_node(node) {
 248                         nasid = cnodeid_to_nasid(node);
 249                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
 250                               -1UL);
 251
 252                         /*
 253                          * Since the BIST collides with memory operations on
 254                          * SHUB 1.1 sn_change_memprotect() cannot be used.
 255                          */
 256                         if (enable_shub_wars_1_1()) {
 257                                 /* open up everything */
 258                                 xpc_prot_vec[node] = (u64)HUB_L((u64 *)
 259                                                                 GLOBAL_MMR_ADDR
 260                                                                 (nasid,
 261                                                   SH1_MD_DQLP_MMR_DIR_PRIVEC0));
 262                                 HUB_S((u64 *)
 263                                       GLOBAL_MMR_ADDR(nasid,
 264                                                    SH1_MD_DQLP_MMR_DIR_PRIVEC0),
 265                                       -1UL);
 266                                 HUB_S((u64 *)
 267                                       GLOBAL_MMR_ADDR(nasid,
 268                                                    SH1_MD_DQRP_MMR_DIR_PRIVEC0),
 269                                       -1UL);
 270                         }
 271                 }
 272         }
 273 }
 274
 275 /*
 276  * Restrict protections to disallow IPI operations (and AMO operations on
 277  * Shub 1.1 systems).
 278  */
 279 void
 280 xpc_restrict_IPI_ops(void)
 281 {
 282         int node;
 283         int nasid;
 284
 285         /* >>> Change SH_IPI_ACCESS code to use SAL call once it is available */
 286
 287         if (is_shub2()) {
 288
 289                 for_each_online_node(node) {
 290                         nasid = cnodeid_to_nasid(node);
 291                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
 292                               xpc_sh2_IPI_access0);
 293                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
 294                               xpc_sh2_IPI_access1);
 295                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
 296                               xpc_sh2_IPI_access2);
 297                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
 298                               xpc_sh2_IPI_access3);
 299                 }
 300
 301         } else {
 302
 303                 for_each_online_node(node) {
 304                         nasid = cnodeid_to_nasid(node);
 305                         HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
 306                               xpc_sh1_IPI_access);
 307
 308                         if (enable_shub_wars_1_1()) {
 309                                 HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
 310                                                    SH1_MD_DQLP_MMR_DIR_PRIVEC0),
 311                                       xpc_prot_vec[node]);
 312                                 HUB_S((u64 *)GLOBAL_MMR_ADDR(nasid,
 313                                                    SH1_MD_DQRP_MMR_DIR_PRIVEC0),
 314                                       xpc_prot_vec[node]);
 315                         }
 316                 }
 317         }
 318 }
 319
 320 /*
 321  * At periodic intervals, scan through all active partitions and ensure
 322  * their heartbeat is still active.  If not, the partition is deactivated.
 323  */
 324 void
 325 xpc_check_remote_hb(void)
 326 {
 327         struct xpc_vars *remote_vars;
 328         struct xpc_partition *part;
 329         short partid;
 330         enum xp_retval ret;
 331
 332         remote_vars = (struct xpc_vars *)xpc_remote_copy_buffer;
 333
 334         for (partid = 0; partid < xp_max_npartitions; partid++) {
 335
 336                 if (xpc_exiting)
 337                         break;
 338
 339                 if (partid == sn_partition_id)
 340                         continue;
 341
 342                 part = &xpc_partitions[partid];
 343
 344                 if (part->act_state == XPC_P_INACTIVE ||
 345                     part->act_state == XPC_P_DEACTIVATING) {
 346                         continue;
 347                 }
 348
 349                 /* pull the remote_hb cache line */
 350                 ret = xp_remote_memcpy(remote_vars,
 351                                        (void *)part->remote_vars_pa,
 352                                        XPC_RP_VARS_SIZE);
 353                 if (ret != xpSuccess) {
 354                         XPC_DEACTIVATE_PARTITION(part, ret);
 355                         continue;
 356                 }
 357
 358                 dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
 359                         " = %ld, heartbeat_offline = %ld, HB_mask = 0x%lx\n",
 360                         partid, remote_vars->heartbeat, part->last_heartbeat,
 361                         remote_vars->heartbeat_offline,
 362                         remote_vars->heartbeating_to_mask);
 363
 364                 if (((remote_vars->heartbeat == part->last_heartbeat) &&
 365                      (remote_vars->heartbeat_offline == 0)) ||
 366                     !xpc_hb_allowed(sn_partition_id, remote_vars)) {
 367
 368                         XPC_DEACTIVATE_PARTITION(part, xpNoHeartbeat);
 369                         continue;
 370                 }
 371
 372                 part->last_heartbeat = remote_vars->heartbeat;
 373         }
 374 }
 375
 376 /*
 377  * Get a copy of a portion of the remote partition's rsvd page.
 378  *
 379  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
 380  * is large enough to contain a copy of their reserved page header and
 381  * part_nasids mask.
 382  */
 383 static enum xp_retval
 384 xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
 385                   struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
 386 {
 387         int i;
 388         enum xp_retval ret;
 389
 390         /* get the reserved page's physical address */
 391
 392         *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
 393         if (*remote_rp_pa == 0)
 394                 return xpNoRsvdPageAddr;
 395
 396         /* pull over the reserved page header and part_nasids mask */
 397         ret = xp_remote_memcpy(remote_rp, (void *)*remote_rp_pa,
 398                                XPC_RP_HEADER_SIZE + xp_sizeof_nasid_mask);
 399         if (ret != xpSuccess)
 400                 return ret;
 401
 402         if (discovered_nasids != NULL) {
 403                 u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
 404
 405                 for (i = 0; i < xp_nasid_mask_words; i++)
 406                         discovered_nasids[i] |= remote_part_nasids[i];
 407         }
 408
 409         /* check that the partid is valid and is for another partition */
 410
 411         if (remote_rp->SAL_partid < 0 ||
 412             remote_rp->SAL_partid >= xp_max_npartitions) {
 413                 return xpInvalidPartid;
 414         }
 415
 416         if (remote_rp->SAL_partid == sn_partition_id)
 417                 return xpLocalPartid;
 418
 419         /* see if the rest of the reserved page has been set up by XPC */
 420         if (timespec_equal(&remote_rp->stamp, &ZERO_STAMP))
 421                 return xpRsvdPageNotSet;
 422
 423         if (XPC_VERSION_MAJOR(remote_rp->version) !=
 424             XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
 425                 return xpBadVersion;
 426         }
 427
 428         if (remote_rp->max_npartitions <= sn_partition_id)
 429                 return xpInvalidPartid;
 430
 431         return xpSuccess;
 432 }
 433
 434 /*
 435  * Get a copy of the remote partition's XPC variables from the reserved page.
 436  *
 437  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
 438  * assumed to be of size XPC_RP_VARS_SIZE.
 439  */
 440 static enum xp_retval
 441 xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
 442 {
 443         enum xp_retval ret;
 444
 445         if (remote_vars_pa == 0)
 446                 return xpVarsNotSet;
 447
 448         /* pull over the cross partition variables */
 449         ret = xp_remote_memcpy(remote_vars, (void *)remote_vars_pa,
 450                                XPC_RP_VARS_SIZE);
 451         if (ret != xpSuccess)
 452                 return ret;
 453
 454         if (XPC_VERSION_MAJOR(remote_vars->version) !=
 455             XPC_VERSION_MAJOR(XPC_V_VERSION)) {
 456                 return xpBadVersion;
 457         }
 458
 459         return xpSuccess;
 460 }
 461
 462 /*
 463  * Update the remote partition's info.
 464  */
 465 static void
 466 xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
 467                           struct timespec *remote_rp_stamp, u64 remote_rp_pa,
 468                           u64 remote_vars_pa, struct xpc_vars *remote_vars)
 469 {
 470         part->remote_rp_version = remote_rp_version;
 471         dev_dbg(xpc_part, "  remote_rp_version = 0x%016x\n",
 472                 part->remote_rp_version);
 473
 474         part->remote_rp_stamp = *remote_rp_stamp;
 475         dev_dbg(xpc_part, "  remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
 476                 part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
 477
 478         part->remote_rp_pa = remote_rp_pa;
 479         dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
 480
 481         part->remote_vars_pa = remote_vars_pa;
 482         dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
 483                 part->remote_vars_pa);
 484
 485         part->last_heartbeat = remote_vars->heartbeat;
 486         dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
 487                 part->last_heartbeat);
 488
 489 /* >>> remote_vars_part_pa and vars_part_pa are sn2 only!!! */
 490         part->remote_vars_part_pa = remote_vars->vars_part_pa;
 491         dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
 492                 part->remote_vars_part_pa);
 493
 494         part->remote_act_nasid = remote_vars->act_nasid;
 495         dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
 496                 part->remote_act_nasid);
 497
 498         part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
 499         dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
 500                 part->remote_act_phys_cpuid);
 501
 502         part->remote_amos_page_pa = remote_vars->amos_page_pa;
 503         dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
 504                 part->remote_amos_page_pa);
 505
 506         part->remote_vars_version = remote_vars->version;
 507         dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
 508                 part->remote_vars_version);
 509 }
 510
 511 /*
 512  * Prior code has determined the nasid which generated an IPI.  Inspect
 513  * that nasid to determine if its partition needs to be activated or
 514  * deactivated.
 515  *
 516  * A partition is consider "awaiting activation" if our partition
 517  * flags indicate it is not active and it has a heartbeat.  A
 518  * partition is considered "awaiting deactivation" if our partition
 519  * flags indicate it is active but it has no heartbeat or it is not
 520  * sending its heartbeat to us.
 521  *
 522  * To determine the heartbeat, the remote nasid must have a properly
 523  * initialized reserved page.
 524  */
 525 static void
 526 xpc_identify_act_IRQ_req(int nasid)
 527 {
 528         struct xpc_rsvd_page *remote_rp;
 529         struct xpc_vars *remote_vars;
 530         u64 remote_rp_pa;
 531         u64 remote_vars_pa;
 532         int remote_rp_version;
 533         int reactivate = 0;
 534         int stamp_diff;
 535         struct timespec remote_rp_stamp = { 0, 0 }; /*>>> ZERO_STAMP */
 536         short partid;
 537         struct xpc_partition *part;
 538         enum xp_retval ret;
 539
 540         /* pull over the reserved page structure */
 541
 542         remote_rp = (struct xpc_rsvd_page *)xpc_remote_copy_buffer;
 543
 544         ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
 545         if (ret != xpSuccess) {
 546                 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
 547                          "which sent interrupt, reason=%d\n", nasid, ret);
 548                 return;
 549         }
 550
 551         remote_vars_pa = remote_rp->sn.vars_pa;
 552         remote_rp_version = remote_rp->version;
 553         if (XPC_SUPPORTS_RP_STAMP(remote_rp_version))
 554                 remote_rp_stamp = remote_rp->stamp;
 555
 556         partid = remote_rp->SAL_partid;
 557         part = &xpc_partitions[partid];
 558
 559         /* pull over the cross partition variables */
 560
 561         remote_vars = (struct xpc_vars *)xpc_remote_copy_buffer;
 562
 563         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
 564         if (ret != xpSuccess) {
 565
 566                 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
 567                          "which sent interrupt, reason=%d\n", nasid, ret);
 568
 569                 XPC_DEACTIVATE_PARTITION(part, ret);
 570                 return;
 571         }
 572
 573         part->act_IRQ_rcvd++;
 574
 575         dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
 576                 "%ld:0x%lx\n", (int)nasid, (int)partid, part->act_IRQ_rcvd,
 577                 remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
 578
 579         if (xpc_partition_disengaged(part) &&
 580             part->act_state == XPC_P_INACTIVE) {
 581
 582                 xpc_update_partition_info(part, remote_rp_version,
 583                                           &remote_rp_stamp, remote_rp_pa,
 584                                           remote_vars_pa, remote_vars);
 585
 586                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 587                         if (xpc_partition_disengage_requested(1UL << partid)) {
 588                                 /*
 589                                  * Other side is waiting on us to disengage,
 590                                  * even though we already have.
 591                                  */
 592                                 return;
 593                         }
 594                 } else {
 595                         /* other side doesn't support disengage requests */
 596                         xpc_clear_partition_disengage_request(1UL << partid);
 597                 }
 598
 599                 xpc_activate_partition(part);
 600                 return;
 601         }
 602
 603         DBUG_ON(part->remote_rp_version == 0);
 604         DBUG_ON(part->remote_vars_version == 0);
 605
 606         if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
 607                 DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
 608                                                        remote_vars_version));
 609
 610                 if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 611                         DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
 612                                                                version));
 613                         /* see if the other side rebooted */
 614                         if (part->remote_amos_page_pa ==
 615                             remote_vars->amos_page_pa &&
 616                             xpc_hb_allowed(sn_partition_id, remote_vars)) {
 617                                 /* doesn't look that way, so ignore the IPI */
 618                                 return;
 619                         }
 620                 }
 621
 622                 /*
 623                  * Other side rebooted and previous XPC didn't support the
 624                  * disengage request, so we don't need to do anything special.
 625                  */
 626
 627                 xpc_update_partition_info(part, remote_rp_version,
 628                                           &remote_rp_stamp, remote_rp_pa,
 629                                           remote_vars_pa, remote_vars);
 630                 part->reactivate_nasid = nasid;
 631                 XPC_DEACTIVATE_PARTITION(part, xpReactivating);
 632                 return;
 633         }
 634
 635         DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
 636
 637         if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
 638                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 639
 640                 /*
 641                  * Other side rebooted and previous XPC did support the
 642                  * disengage request, but the new one doesn't.
 643                  */
 644
 645                 xpc_clear_partition_engaged(1UL << partid);
 646                 xpc_clear_partition_disengage_request(1UL << partid);
 647
 648                 xpc_update_partition_info(part, remote_rp_version,
 649                                           &remote_rp_stamp, remote_rp_pa,
 650                                           remote_vars_pa, remote_vars);
 651                 reactivate = 1;
 652
 653         } else {
 654                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
 655
 656                 stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
 657                                                 &remote_rp_stamp);
 658                 if (stamp_diff != 0) {
 659                         DBUG_ON(stamp_diff >= 0);
 660
 661                         /*
 662                          * Other side rebooted and the previous XPC did support
 663                          * the disengage request, as does the new one.
 664                          */
 665
 666                         DBUG_ON(xpc_partition_engaged(1UL << partid));
 667                         DBUG_ON(xpc_partition_disengage_requested(1UL <<
 668                                                                   partid));
 669
 670                         xpc_update_partition_info(part, remote_rp_version,
 671                                                   &remote_rp_stamp,
 672                                                   remote_rp_pa, remote_vars_pa,
 673                                                   remote_vars);
 674                         reactivate = 1;
 675                 }
 676         }
 677
 678         if (part->disengage_request_timeout > 0 &&
 679             !xpc_partition_disengaged(part)) {
 680                 /* still waiting on other side to disengage from us */
 681                 return;
 682         }
 683
 684         if (reactivate) {
 685                 part->reactivate_nasid = nasid;
 686                 XPC_DEACTIVATE_PARTITION(part, xpReactivating);
 687
 688         } else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
 689                    xpc_partition_disengage_requested(1UL << partid)) {
 690                 XPC_DEACTIVATE_PARTITION(part, xpOtherGoingDown);
 691         }
 692 }
 693
 694 /*
 695  * Loop through the activation AMO variables and process any bits
 696  * which are set.  Each bit indicates a nasid sending a partition
 697  * activation or deactivation request.
 698  *
 699  * Return #of IRQs detected.
 700  */
 701 int
 702 xpc_identify_act_IRQ_sender(void)
 703 {
 704         int word, bit;
 705         u64 nasid_mask;
 706         u64 nasid;              /* remote nasid */
 707         int n_IRQs_detected = 0;
 708         AMO_t *act_amos;
 709
 710         act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
 711
 712         /* scan through act AMO variable looking for non-zero entries */
 713         for (word = 0; word < xp_nasid_mask_words; word++) {
 714
 715                 if (xpc_exiting)
 716                         break;
 717
 718                 nasid_mask = xpc_IPI_receive(&act_amos[word]);
 719                 if (nasid_mask == 0) {
 720                         /* no IRQs from nasids in this variable */
 721                         continue;
 722                 }
 723
 724                 dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
 725                         nasid_mask);
 726
 727                 /*
 728                  * If this nasid has been added to the machine since
 729                  * our partition was reset, this will retain the
 730                  * remote nasid in our reserved pages machine mask.
 731                  * This is used in the event of module reload.
 732                  */
 733                 xpc_mach_nasids[word] |= nasid_mask;
 734
 735                 /* locate the nasid(s) which sent interrupts */
 736
 737                 for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
 738                         if (nasid_mask & (1UL << bit)) {
 739                                 n_IRQs_detected++;
 740                                 nasid = XPC_NASID_FROM_W_B(word, bit);
 741                                 dev_dbg(xpc_part, "interrupt from nasid %ld\n",
 742                                         nasid);
 743                                 xpc_identify_act_IRQ_req(nasid);
 744                         }
 745                 }
 746         }
 747         return n_IRQs_detected;
 748 }
 749
 750 /*
 751  * See if the other side has responded to a partition disengage request
 752  * from us.
 753  */
 754 int
 755 xpc_partition_disengaged(struct xpc_partition *part)
 756 {
 757         short partid = XPC_PARTID(part);
 758         int disengaged;
 759
 760         disengaged = (xpc_partition_engaged(1UL << partid) == 0);
 761         if (part->disengage_request_timeout) {
 762                 if (!disengaged) {
 763                         if (time_before(jiffies,
 764                             part->disengage_request_timeout)) {
 765                                 /* timelimit hasn't been reached yet */
 766                                 return 0;
 767                         }
 768
 769                         /*
 770                          * Other side hasn't responded to our disengage
 771                          * request in a timely fashion, so assume it's dead.
 772                          */
 773
 774                         dev_info(xpc_part, "disengage from remote partition %d "
 775                                  "timed out\n", partid);
 776                         xpc_disengage_request_timedout = 1;
 777                         xpc_clear_partition_engaged(1UL << partid);
 778                         disengaged = 1;
 779                 }
 780                 part->disengage_request_timeout = 0;
 781
 782                 /* cancel the timer function, provided it's not us */
 783                 if (!in_interrupt()) {
 784                         del_singleshot_timer_sync(&part->
 785                                                   disengage_request_timer);
 786                 }
 787
 788                 DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
 789                         part->act_state != XPC_P_INACTIVE);
 790                 if (part->act_state != XPC_P_INACTIVE)
 791                         xpc_wakeup_channel_mgr(part);
 792
 793                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version))
 794                         xpc_cancel_partition_disengage_request(part);
 795         }
 796         return disengaged;
 797 }
 798
 799 /*
 800  * Mark specified partition as active.
 801  */
 802 enum xp_retval
 803 xpc_mark_partition_active(struct xpc_partition *part)
 804 {
 805         unsigned long irq_flags;
 806         enum xp_retval ret;
 807
 808         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
 809
 810         spin_lock_irqsave(&part->act_lock, irq_flags);
 811         if (part->act_state == XPC_P_ACTIVATING) {
 812                 part->act_state = XPC_P_ACTIVE;
 813                 ret = xpSuccess;
 814         } else {
 815                 DBUG_ON(part->reason == xpSuccess);
 816                 ret = part->reason;
 817         }
 818         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 819
 820         return ret;
 821 }
 822
 823 /*
 824  * Notify XPC that the partition is down.
 825  */
 826 void
 827 xpc_deactivate_partition(const int line, struct xpc_partition *part,
 828                          enum xp_retval reason)
 829 {
 830         unsigned long irq_flags;
 831
 832         spin_lock_irqsave(&part->act_lock, irq_flags);
 833
 834         if (part->act_state == XPC_P_INACTIVE) {
 835                 XPC_SET_REASON(part, reason, line);
 836                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 837                 if (reason == xpReactivating) {
 838                         /* we interrupt ourselves to reactivate partition */
 839                         xpc_IPI_send_reactivate(part);
 840                 }
 841                 return;
 842         }
 843         if (part->act_state == XPC_P_DEACTIVATING) {
 844                 if ((part->reason == xpUnloading && reason != xpUnloading) ||
 845                     reason == xpReactivating) {
 846                         XPC_SET_REASON(part, reason, line);
 847                 }
 848                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 849                 return;
 850         }
 851
 852         part->act_state = XPC_P_DEACTIVATING;
 853         XPC_SET_REASON(part, reason, line);
 854
 855         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 856
 857         if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
 858                 xpc_request_partition_disengage(part);
 859                 xpc_IPI_send_disengage(part);
 860
 861                 /* set a timelimit on the disengage request */
 862                 part->disengage_request_timeout = jiffies +
 863                     (xpc_disengage_request_timelimit * HZ);
 864                 part->disengage_request_timer.expires =
 865                     part->disengage_request_timeout;
 866                 add_timer(&part->disengage_request_timer);
 867         }
 868
 869         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
 870                 XPC_PARTID(part), reason);
 871
 872         xpc_partition_going_down(part, reason);
 873 }
 874
 875 /*
 876  * Mark specified partition as inactive.
 877  */
 878 void
 879 xpc_mark_partition_inactive(struct xpc_partition *part)
 880 {
 881         unsigned long irq_flags;
 882
 883         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
 884                 XPC_PARTID(part));
 885
 886         spin_lock_irqsave(&part->act_lock, irq_flags);
 887         part->act_state = XPC_P_INACTIVE;
 888         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 889         part->remote_rp_pa = 0;
 890 }
 891
 892 /*
 893  * SAL has provided a partition and machine mask.  The partition mask
 894  * contains a bit for each even nasid in our partition.  The machine
 895  * mask contains a bit for each even nasid in the entire machine.
 896  *
 897  * Using those two bit arrays, we can determine which nasids are
 898  * known in the machine.  Each should also have a reserved page
 899  * initialized if they are available for partitioning.
 900  */
 901 void
 902 xpc_discovery(void)
 903 {
 904         void *remote_rp_base;
 905         struct xpc_rsvd_page *remote_rp;
 906         struct xpc_vars *remote_vars;
 907         u64 remote_rp_pa;
 908         u64 remote_vars_pa;
 909         int region;
 910         int region_size;
 911         int max_regions;
 912         int nasid;
 913         struct xpc_rsvd_page *rp;
 914         short partid;
 915         struct xpc_partition *part;
 916         u64 *discovered_nasids;
 917         enum xp_retval ret;
 918
 919         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
 920                                                   xp_sizeof_nasid_mask,
 921                                                   GFP_KERNEL, &remote_rp_base);
 922         if (remote_rp == NULL)
 923                 return;
 924
 925         remote_vars = (struct xpc_vars *)remote_rp;
 926
 927         discovered_nasids = kzalloc(sizeof(u64) * xp_nasid_mask_words,
 928                                     GFP_KERNEL);
 929         if (discovered_nasids == NULL) {
 930                 kfree(remote_rp_base);
 931                 return;
 932         }
 933
 934         rp = (struct xpc_rsvd_page *)xpc_rsvd_page;
 935
 936         /*
 937          * The term 'region' in this context refers to the minimum number of
 938          * nodes that can comprise an access protection grouping. The access
 939          * protection is in regards to memory, IOI and IPI.
 940          */
 941         max_regions = 64;
 942         region_size = sn_region_size;
 943
 944         switch (region_size) {
 945         case 128:
 946                 max_regions *= 2;
 947         case 64:
 948                 max_regions *= 2;
 949         case 32:
 950                 max_regions *= 2;
 951                 region_size = 16;
 952                 DBUG_ON(!is_shub2());
 953         }
 954
 955         for (region = 0; region < max_regions; region++) {
 956
 957                 if (xpc_exiting)
 958                         break;
 959
 960                 dev_dbg(xpc_part, "searching region %d\n", region);
 961
 962                 for (nasid = (region * region_size * 2);
 963                      nasid < ((region + 1) * region_size * 2); nasid += 2) {
 964
 965                         if (xpc_exiting)
 966                                 break;
 967
 968                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
 969
 970                         if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
 971                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
 972                                         "part of the local partition; skipping "
 973                                         "region\n", nasid);
 974                                 break;
 975                         }
 976
 977                         if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
 978                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
 979                                         "not on Numa-Link network at reset\n",
 980                                         nasid);
 981                                 continue;
 982                         }
 983
 984                         if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
 985                                 dev_dbg(xpc_part, "Nasid %d is part of a "
 986                                         "partition which was previously "
 987                                         "discovered\n", nasid);
 988                                 continue;
 989                         }
 990
 991                         /* pull over the reserved page structure */
 992
 993                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
 994                                                 remote_rp, &remote_rp_pa);
 995                         if (ret != xpSuccess) {
 996                                 dev_dbg(xpc_part, "unable to get reserved page "
 997                                         "from nasid %d, reason=%d\n", nasid,
 998                                         ret);
 999
1000                                 if (ret == xpLocalPartid)
1001                                         break;
1002
1003                                 continue;
1004                         }
1005
1006                         remote_vars_pa = remote_rp->sn.vars_pa;
1007
1008                         partid = remote_rp->SAL_partid;
1009                         part = &xpc_partitions[partid];
1010
1011                         /* pull over the cross partition variables */
1012
1013                         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
1014                         if (ret != xpSuccess) {
1015                                 dev_dbg(xpc_part, "unable to get XPC variables "
1016                                         "from nasid %d, reason=%d\n", nasid,
1017                                         ret);
1018
1019                                 XPC_DEACTIVATE_PARTITION(part, ret);
1020                                 continue;
1021                         }
1022
1023                         if (part->act_state != XPC_P_INACTIVE) {
1024                                 dev_dbg(xpc_part, "partition %d on nasid %d is "
1025                                         "already activating\n", partid, nasid);
1026                                 break;
1027                         }
1028
1029                         /*
1030                          * Register the remote partition's AMOs with SAL so it
1031                          * can handle and cleanup errors within that address
1032                          * range should the remote partition go down. We don't
1033                          * unregister this range because it is difficult to
1034                          * tell when outstanding writes to the remote partition
1035                          * are finished and thus when it is thus safe to
1036                          * unregister. This should not result in wasted space
1037                          * in the SAL xp_addr_region table because we should
1038                          * get the same page for remote_act_amos_pa after
1039                          * module reloads and system reboots.
1040                          */
1041                         if (sn_register_xp_addr_region
1042                             (remote_vars->amos_page_pa, PAGE_SIZE, 1) < 0) {
1043                                 dev_dbg(xpc_part,
1044                                         "partition %d failed to "
1045                                         "register xp_addr region 0x%016lx\n",
1046                                         partid, remote_vars->amos_page_pa);
1047
1048                                 XPC_SET_REASON(part, xpPhysAddrRegFailed,
1049                                                __LINE__);
1050                                 break;
1051                         }
1052
1053                         /*
1054                          * The remote nasid is valid and available.
1055                          * Send an interrupt to that nasid to notify
1056                          * it that we are ready to begin activation.
1057                          */
1058                         dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
1059                                 "nasid %d, phys_cpuid 0x%x\n",
1060                                 remote_vars->amos_page_pa,
1061                                 remote_vars->act_nasid,
1062                                 remote_vars->act_phys_cpuid);
1063
1064                         if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
1065                                                            version)) {
1066                                 part->remote_amos_page_pa =
1067                                     remote_vars->amos_page_pa;
1068                                 xpc_mark_partition_disengaged(part);
1069                                 xpc_cancel_partition_disengage_request(part);
1070                         }
1071                         xpc_IPI_send_activate(remote_vars);
1072                 }
1073         }
1074
1075         kfree(discovered_nasids);
1076         kfree(remote_rp_base);
1077 }
1078
1079 /*
1080  * Given a partid, get the nasids owned by that partition from the
1081  * remote partition's reserved page.
1082  */
1083 enum xp_retval
1084 xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
1085 {
1086         struct xpc_partition *part;
1087         u64 part_nasid_pa;
1088
1089         part = &xpc_partitions[partid];
1090         if (part->remote_rp_pa == 0)
1091                 return xpPartitionDown;
1092
1093         memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
1094
1095         part_nasid_pa = (u64)XPC_RP_PART_NASIDS(part->remote_rp_pa);
1096
1097         return xp_remote_memcpy(nasid_mask, (void *)part_nasid_pa,
1098                                 xp_sizeof_nasid_mask);
1099 }