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/device.h>
  19 #include <linux/hardirq.h>
  20 #include "xpc.h"
  21
  22 /* XPC is exiting flag */
  23 int xpc_exiting;
  24
  25 /* this partition's reserved page pointers */
  26 struct xpc_rsvd_page *xpc_rsvd_page;
  27 static unsigned long *xpc_part_nasids;
  28 unsigned long *xpc_mach_nasids;
  29
  30 static int xpc_nasid_mask_nbytes;       /* #of bytes in nasid mask */
  31 int xpc_nasid_mask_nlongs;      /* #of longs in nasid mask */
  32
  33 struct xpc_partition *xpc_partitions;
  34
  35 /*
  36  * Guarantee that the kmalloc'd memory is cacheline aligned.
  37  */
  38 void *
  39 xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
  40 {
  41         /* see if kmalloc will give us cachline aligned memory by default */
  42         *base = kmalloc(size, flags);
  43         if (*base == NULL)
  44                 return NULL;
  45
  46         if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
  47                 return *base;
  48
  49         kfree(*base);
  50
  51         /* nope, we'll have to do it ourselves */
  52         *base = kmalloc(size + L1_CACHE_BYTES, flags);
  53         if (*base == NULL)
  54                 return NULL;
  55
  56         return (void *)L1_CACHE_ALIGN((u64)*base);
  57 }
  58
  59 /*
  60  * Given a nasid, get the physical address of the  partition's reserved page
  61  * for that nasid. This function returns 0 on any error.
  62  */
  63 static unsigned long
  64 xpc_get_rsvd_page_pa(int nasid)
  65 {
  66         enum xp_retval ret;
  67         u64 cookie = 0;
  68         unsigned long rp_pa = nasid;    /* seed with nasid */
  69         size_t len = 0;
  70         size_t buf_len = 0;
  71         void *buf = buf;
  72         void *buf_base = NULL;
  73
  74         while (1) {
  75
  76                 ret = xpc_get_partition_rsvd_page_pa(buf, &cookie, &rp_pa,
  77                                                      &len);
  78
  79                 dev_dbg(xpc_part, "SAL returned with ret=%d, cookie=0x%016lx, "
  80                         "address=0x%016lx, len=0x%016lx\n", ret,
  81                         (unsigned long)cookie, rp_pa, len);
  82
  83                 if (ret != xpNeedMoreInfo)
  84                         break;
  85
  86                 /* !!! L1_CACHE_ALIGN() is only a sn2-bte_copy requirement */
  87                 if (L1_CACHE_ALIGN(len) > buf_len) {
  88                         kfree(buf_base);
  89                         buf_len = L1_CACHE_ALIGN(len);
  90                         buf = xpc_kmalloc_cacheline_aligned(buf_len, GFP_KERNEL,
  91                                                             &buf_base);
  92                         if (buf_base == NULL) {
  93                                 dev_err(xpc_part, "unable to kmalloc "
  94                                         "len=0x%016lx\n", buf_len);
  95                                 ret = xpNoMemory;
  96                                 break;
  97                         }
  98                 }
  99
 100                 ret = xp_remote_memcpy(xp_pa(buf), rp_pa, buf_len);
 101                 if (ret != xpSuccess) {
 102                         dev_dbg(xpc_part, "xp_remote_memcpy failed %d\n", ret);
 103                         break;
 104                 }
 105         }
 106
 107         kfree(buf_base);
 108
 109         if (ret != xpSuccess)
 110                 rp_pa = 0;
 111
 112         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
 113         return rp_pa;
 114 }
 115
 116 /*
 117  * Fill the partition reserved page with the information needed by
 118  * other partitions to discover we are alive and establish initial
 119  * communications.
 120  */
 121 struct xpc_rsvd_page *
 122 xpc_setup_rsvd_page(void)
 123 {
 124         struct xpc_rsvd_page *rp;
 125         unsigned long rp_pa;
 126         unsigned long new_ts_jiffies;
 127
 128         /* get the local reserved page's address */
 129
 130         preempt_disable();
 131         rp_pa = xpc_get_rsvd_page_pa(xp_cpu_to_nasid(smp_processor_id()));
 132         preempt_enable();
 133         if (rp_pa == 0) {
 134                 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
 135                 return NULL;
 136         }
 137         rp = (struct xpc_rsvd_page *)__va(rp_pa);
 138
 139         if (rp->SAL_version < 3) {
 140                 /* SAL_versions < 3 had a SAL_partid defined as a u8 */
 141                 rp->SAL_partid &= 0xff;
 142         }
 143         BUG_ON(rp->SAL_partid != xp_partition_id);
 144
 145         if (rp->SAL_partid < 0 || rp->SAL_partid >= xp_max_npartitions) {
 146                 dev_err(xpc_part, "the reserved page's partid of %d is outside "
 147                         "supported range (< 0 || >= %d)\n", rp->SAL_partid,
 148                         xp_max_npartitions);
 149                 return NULL;
 150         }
 151
 152         rp->version = XPC_RP_VERSION;
 153         rp->max_npartitions = xp_max_npartitions;
 154
 155         /* establish the actual sizes of the nasid masks */
 156         if (rp->SAL_version == 1) {
 157                 /* SAL_version 1 didn't set the nasids_size field */
 158                 rp->SAL_nasids_size = 128;
 159         }
 160         xpc_nasid_mask_nbytes = rp->SAL_nasids_size;
 161         xpc_nasid_mask_nlongs = BITS_TO_LONGS(rp->SAL_nasids_size *
 162                                               BITS_PER_BYTE);
 163
 164         /* setup the pointers to the various items in the reserved page */
 165         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
 166         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
 167
 168         if (xpc_rsvd_page_init(rp) != xpSuccess)
 169                 return NULL;
 170
 171         /*
 172          * Set timestamp of when reserved page was setup by XPC.
 173          * This signifies to the remote partition that our reserved
 174          * page is initialized.
 175          */
 176         new_ts_jiffies = jiffies;
 177         if (new_ts_jiffies == 0 || new_ts_jiffies == rp->ts_jiffies)
 178                 new_ts_jiffies++;
 179         rp->ts_jiffies = new_ts_jiffies;
 180
 181         return rp;
 182 }
 183
 184 /*
 185  * Get a copy of a portion of the remote partition's rsvd page.
 186  *
 187  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
 188  * is large enough to contain a copy of their reserved page header and
 189  * part_nasids mask.
 190  */
 191 enum xp_retval
 192 xpc_get_remote_rp(int nasid, unsigned long *discovered_nasids,
 193                   struct xpc_rsvd_page *remote_rp, unsigned long *remote_rp_pa)
 194 {
 195         int l;
 196         enum xp_retval ret;
 197
 198         /* get the reserved page's physical address */
 199
 200         *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
 201         if (*remote_rp_pa == 0)
 202                 return xpNoRsvdPageAddr;
 203
 204         /* pull over the reserved page header and part_nasids mask */
 205         ret = xp_remote_memcpy(xp_pa(remote_rp), *remote_rp_pa,
 206                                XPC_RP_HEADER_SIZE + xpc_nasid_mask_nbytes);
 207         if (ret != xpSuccess)
 208                 return ret;
 209
 210         if (discovered_nasids != NULL) {
 211                 unsigned long *remote_part_nasids =
 212                     XPC_RP_PART_NASIDS(remote_rp);
 213
 214                 for (l = 0; l < xpc_nasid_mask_nlongs; l++)
 215                         discovered_nasids[l] |= remote_part_nasids[l];
 216         }
 217
 218         /* zero timestamp indicates the reserved page has not been setup */
 219         if (remote_rp->ts_jiffies == 0)
 220                 return xpRsvdPageNotSet;
 221
 222         if (XPC_VERSION_MAJOR(remote_rp->version) !=
 223             XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
 224                 return xpBadVersion;
 225         }
 226
 227         /* check that both remote and local partids are valid for each side */
 228         if (remote_rp->SAL_partid < 0 ||
 229             remote_rp->SAL_partid >= xp_max_npartitions ||
 230             remote_rp->max_npartitions <= xp_partition_id) {
 231                 return xpInvalidPartid;
 232         }
 233
 234         if (remote_rp->SAL_partid == xp_partition_id)
 235                 return xpLocalPartid;
 236
 237         return xpSuccess;
 238 }
 239
 240 /*
 241  * See if the other side has responded to a partition deactivate request
 242  * from us. Though we requested the remote partition to deactivate with regard
 243  * to us, we really only need to wait for the other side to disengage from us.
 244  */
 245 int
 246 xpc_partition_disengaged(struct xpc_partition *part)
 247 {
 248         short partid = XPC_PARTID(part);
 249         int disengaged;
 250
 251         disengaged = !xpc_partition_engaged(partid);
 252         if (part->disengage_timeout) {
 253                 if (!disengaged) {
 254                         if (time_is_after_jiffies(part->disengage_timeout)) {
 255                                 /* timelimit hasn't been reached yet */
 256                                 return 0;
 257                         }
 258
 259                         /*
 260                          * Other side hasn't responded to our deactivate
 261                          * request in a timely fashion, so assume it's dead.
 262                          */
 263
 264                         dev_info(xpc_part, "deactivate request to remote "
 265                                  "partition %d timed out\n", partid);
 266                         xpc_disengage_timedout = 1;
 267                         xpc_assume_partition_disengaged(partid);
 268                         disengaged = 1;
 269                 }
 270                 part->disengage_timeout = 0;
 271
 272                 /* cancel the timer function, provided it's not us */
 273                 if (!in_interrupt())
 274                         del_singleshot_timer_sync(&part->disengage_timer);
 275
 276                 DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING &&
 277                         part->act_state != XPC_P_AS_INACTIVE);
 278                 if (part->act_state != XPC_P_AS_INACTIVE)
 279                         xpc_wakeup_channel_mgr(part);
 280
 281                 xpc_cancel_partition_deactivation_request(part);
 282         }
 283         return disengaged;
 284 }
 285
 286 /*
 287  * Mark specified partition as active.
 288  */
 289 enum xp_retval
 290 xpc_mark_partition_active(struct xpc_partition *part)
 291 {
 292         unsigned long irq_flags;
 293         enum xp_retval ret;
 294
 295         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
 296
 297         spin_lock_irqsave(&part->act_lock, irq_flags);
 298         if (part->act_state == XPC_P_AS_ACTIVATING) {
 299                 part->act_state = XPC_P_AS_ACTIVE;
 300                 ret = xpSuccess;
 301         } else {
 302                 DBUG_ON(part->reason == xpSuccess);
 303                 ret = part->reason;
 304         }
 305         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 306
 307         return ret;
 308 }
 309
 310 /*
 311  * Start the process of deactivating the specified partition.
 312  */
 313 void
 314 xpc_deactivate_partition(const int line, struct xpc_partition *part,
 315                          enum xp_retval reason)
 316 {
 317         unsigned long irq_flags;
 318
 319         spin_lock_irqsave(&part->act_lock, irq_flags);
 320
 321         if (part->act_state == XPC_P_AS_INACTIVE) {
 322                 XPC_SET_REASON(part, reason, line);
 323                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 324                 if (reason == xpReactivating) {
 325                         /* we interrupt ourselves to reactivate partition */
 326                         xpc_request_partition_reactivation(part);
 327                 }
 328                 return;
 329         }
 330         if (part->act_state == XPC_P_AS_DEACTIVATING) {
 331                 if ((part->reason == xpUnloading && reason != xpUnloading) ||
 332                     reason == xpReactivating) {
 333                         XPC_SET_REASON(part, reason, line);
 334                 }
 335                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 336                 return;
 337         }
 338
 339         part->act_state = XPC_P_AS_DEACTIVATING;
 340         XPC_SET_REASON(part, reason, line);
 341
 342         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 343
 344         /* ask remote partition to deactivate with regard to us */
 345         xpc_request_partition_deactivation(part);
 346
 347         /* set a timelimit on the disengage phase of the deactivation request */
 348         part->disengage_timeout = jiffies + (xpc_disengage_timelimit * HZ);
 349         part->disengage_timer.expires = part->disengage_timeout;
 350         add_timer(&part->disengage_timer);
 351
 352         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
 353                 XPC_PARTID(part), reason);
 354
 355         xpc_partition_going_down(part, reason);
 356 }
 357
 358 /*
 359  * Mark specified partition as inactive.
 360  */
 361 void
 362 xpc_mark_partition_inactive(struct xpc_partition *part)
 363 {
 364         unsigned long irq_flags;
 365
 366         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
 367                 XPC_PARTID(part));
 368
 369         spin_lock_irqsave(&part->act_lock, irq_flags);
 370         part->act_state = XPC_P_AS_INACTIVE;
 371         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 372         part->remote_rp_pa = 0;
 373 }
 374
 375 /*
 376  * SAL has provided a partition and machine mask.  The partition mask
 377  * contains a bit for each even nasid in our partition.  The machine
 378  * mask contains a bit for each even nasid in the entire machine.
 379  *
 380  * Using those two bit arrays, we can determine which nasids are
 381  * known in the machine.  Each should also have a reserved page
 382  * initialized if they are available for partitioning.
 383  */
 384 void
 385 xpc_discovery(void)
 386 {
 387         void *remote_rp_base;
 388         struct xpc_rsvd_page *remote_rp;
 389         unsigned long remote_rp_pa;
 390         int region;
 391         int region_size;
 392         int max_regions;
 393         int nasid;
 394         struct xpc_rsvd_page *rp;
 395         unsigned long *discovered_nasids;
 396         enum xp_retval ret;
 397
 398         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
 399                                                   xpc_nasid_mask_nbytes,
 400                                                   GFP_KERNEL, &remote_rp_base);
 401         if (remote_rp == NULL)
 402                 return;
 403
 404         discovered_nasids = kzalloc(sizeof(long) * xpc_nasid_mask_nlongs,
 405                                     GFP_KERNEL);
 406         if (discovered_nasids == NULL) {
 407                 kfree(remote_rp_base);
 408                 return;
 409         }
 410
 411         rp = (struct xpc_rsvd_page *)xpc_rsvd_page;
 412
 413         /*
 414          * The term 'region' in this context refers to the minimum number of
 415          * nodes that can comprise an access protection grouping. The access
 416          * protection is in regards to memory, IOI and IPI.
 417          */
 418         max_regions = 64;
 419         region_size = xp_region_size;
 420
 421         switch (region_size) {
 422         case 128:
 423                 max_regions *= 2;
 424         case 64:
 425                 max_regions *= 2;
 426         case 32:
 427                 max_regions *= 2;
 428                 region_size = 16;
 429                 DBUG_ON(!is_shub2());
 430         }
 431
 432         for (region = 0; region < max_regions; region++) {
 433
 434                 if (xpc_exiting)
 435                         break;
 436
 437                 dev_dbg(xpc_part, "searching region %d\n", region);
 438
 439                 for (nasid = (region * region_size * 2);
 440                      nasid < ((region + 1) * region_size * 2); nasid += 2) {
 441
 442                         if (xpc_exiting)
 443                                 break;
 444
 445                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
 446
 447                         if (test_bit(nasid / 2, xpc_part_nasids)) {
 448                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
 449                                         "part of the local partition; skipping "
 450                                         "region\n", nasid);
 451                                 break;
 452                         }
 453
 454                         if (!(test_bit(nasid / 2, xpc_mach_nasids))) {
 455                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
 456                                         "not on Numa-Link network at reset\n",
 457                                         nasid);
 458                                 continue;
 459                         }
 460
 461                         if (test_bit(nasid / 2, discovered_nasids)) {
 462                                 dev_dbg(xpc_part, "Nasid %d is part of a "
 463                                         "partition which was previously "
 464                                         "discovered\n", nasid);
 465                                 continue;
 466                         }
 467
 468                         /* pull over the rsvd page header & part_nasids mask */
 469
 470                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
 471                                                 remote_rp, &remote_rp_pa);
 472                         if (ret != xpSuccess) {
 473                                 dev_dbg(xpc_part, "unable to get reserved page "
 474                                         "from nasid %d, reason=%d\n", nasid,
 475                                         ret);
 476
 477                                 if (ret == xpLocalPartid)
 478                                         break;
 479
 480                                 continue;
 481                         }
 482
 483                         xpc_request_partition_activation(remote_rp,
 484                                                          remote_rp_pa, nasid);
 485                 }
 486         }
 487
 488         kfree(discovered_nasids);
 489         kfree(remote_rp_base);
 490 }
 491
 492 /*
 493  * Given a partid, get the nasids owned by that partition from the
 494  * remote partition's reserved page.
 495  */
 496 enum xp_retval
 497 xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
 498 {
 499         struct xpc_partition *part;
 500         unsigned long part_nasid_pa;
 501
 502         part = &xpc_partitions[partid];
 503         if (part->remote_rp_pa == 0)
 504                 return xpPartitionDown;
 505
 506         memset(nasid_mask, 0, xpc_nasid_mask_nbytes);
 507
 508         part_nasid_pa = (unsigned long)XPC_RP_PART_NASIDS(part->remote_rp_pa);
 509
 510         return xp_remote_memcpy(xp_pa(nasid_mask), part_nasid_pa,
 511                                 xpc_nasid_mask_nbytes);
 512 }