root/drivers/misc/sgi-xp/xpc_partition.c

DEFINITIONS

1. xpc_kmalloc_cacheline_aligned
2. xpc_get_rsvd_page_pa
3. xpc_setup_rsvd_page
4. xpc_teardown_rsvd_page
5. xpc_get_remote_rp
6. xpc_partition_disengaged
7. xpc_mark_partition_active
8. xpc_deactivate_partition
9. xpc_mark_partition_inactive
10. xpc_discovery
11. xpc_initiate_partid_to_nasids

   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 <linux/slab.h>
  21 #include "xpc.h"
  22 #include <asm/uv/uv_hub.h>
  23 
  24 /* XPC is exiting flag */
  25 int xpc_exiting;
  26 
  27 /* this partition's reserved page pointers */
  28 struct xpc_rsvd_page *xpc_rsvd_page;
  29 static unsigned long *xpc_part_nasids;
  30 unsigned long *xpc_mach_nasids;
  31 
  32 static int xpc_nasid_mask_nbytes;       /* #of bytes in nasid mask */
  33 int xpc_nasid_mask_nlongs;      /* #of longs in nasid mask */
  34 
  35 struct xpc_partition *xpc_partitions;
  36 
  37 /*
  38  * Guarantee that the kmalloc'd memory is cacheline aligned.
  39  */
  40 void *
  41 xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
  42 {
  43         /* see if kmalloc will give us cachline aligned memory by default */
  44         *base = kmalloc(size, flags);
  45         if (*base == NULL)
  46                 return NULL;
  47 
  48         if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
  49                 return *base;
  50 
  51         kfree(*base);
  52 
  53         /* nope, we'll have to do it ourselves */
  54         *base = kmalloc(size + L1_CACHE_BYTES, flags);
  55         if (*base == NULL)
  56                 return NULL;
  57 
  58         return (void *)L1_CACHE_ALIGN((u64)*base);
  59 }
  60 
  61 /*
  62  * Given a nasid, get the physical address of the  partition's reserved page
  63  * for that nasid. This function returns 0 on any error.
  64  */
  65 static unsigned long
  66 xpc_get_rsvd_page_pa(int nasid)
  67 {
  68         enum xp_retval ret;
  69         u64 cookie = 0;
  70         unsigned long rp_pa = nasid;    /* seed with nasid */
  71         size_t len = 0;
  72         size_t buf_len = 0;
  73         void *buf = NULL;
  74         void *buf_base = NULL;
  75         enum xp_retval (*get_partition_rsvd_page_pa)
  76                 (void *, u64 *, unsigned long *, size_t *) =
  77                 xpc_arch_ops.get_partition_rsvd_page_pa;
  78 
  79         while (1) {
  80 
  81                 /* !!! rp_pa will need to be _gpa on UV.
  82                  * ??? So do we save it into the architecture specific parts
  83                  * ??? of the xpc_partition structure? Do we rename this
  84                  * ??? function or have two versions? Rename rp_pa for UV to
  85                  * ??? rp_gpa?
  86                  */
  87                 ret = get_partition_rsvd_page_pa(buf, &cookie, &rp_pa, &len);
  88 
  89                 dev_dbg(xpc_part, "SAL returned with ret=%d, cookie=0x%016lx, "
  90                         "address=0x%016lx, len=0x%016lx\n", ret,
  91                         (unsigned long)cookie, rp_pa, len);
  92 
  93                 if (ret != xpNeedMoreInfo)
  94                         break;
  95 
  96                 if (len > buf_len) {
  97                         kfree(buf_base);
  98                         buf_len = L1_CACHE_ALIGN(len);
  99                         buf = xpc_kmalloc_cacheline_aligned(buf_len, GFP_KERNEL,
 100                                                             &buf_base);
 101                         if (buf_base == NULL) {
 102                                 dev_err(xpc_part, "unable to kmalloc "
 103                                         "len=0x%016lx\n", buf_len);
 104                                 ret = xpNoMemory;
 105                                 break;
 106                         }
 107                 }
 108 
 109                 ret = xp_remote_memcpy(xp_pa(buf), rp_pa, len);
 110                 if (ret != xpSuccess) {
 111                         dev_dbg(xpc_part, "xp_remote_memcpy failed %d\n", ret);
 112                         break;
 113                 }
 114         }
 115 
 116         kfree(buf_base);
 117 
 118         if (ret != xpSuccess)
 119                 rp_pa = 0;
 120 
 121         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
 122         return rp_pa;
 123 }
 124 
 125 /*
 126  * Fill the partition reserved page with the information needed by
 127  * other partitions to discover we are alive and establish initial
 128  * communications.
 129  */
 130 int
 131 xpc_setup_rsvd_page(void)
 132 {
 133         int ret;
 134         struct xpc_rsvd_page *rp;
 135         unsigned long rp_pa;
 136         unsigned long new_ts_jiffies;
 137 
 138         /* get the local reserved page's address */
 139 
 140         preempt_disable();
 141         rp_pa = xpc_get_rsvd_page_pa(xp_cpu_to_nasid(smp_processor_id()));
 142         preempt_enable();
 143         if (rp_pa == 0) {
 144                 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
 145                 return -ESRCH;
 146         }
 147         rp = (struct xpc_rsvd_page *)__va(xp_socket_pa(rp_pa));
 148 
 149         if (rp->SAL_version < 3) {
 150                 /* SAL_versions < 3 had a SAL_partid defined as a u8 */
 151                 rp->SAL_partid &= 0xff;
 152         }
 153         BUG_ON(rp->SAL_partid != xp_partition_id);
 154 
 155         if (rp->SAL_partid < 0 || rp->SAL_partid >= xp_max_npartitions) {
 156                 dev_err(xpc_part, "the reserved page's partid of %d is outside "
 157                         "supported range (< 0 || >= %d)\n", rp->SAL_partid,
 158                         xp_max_npartitions);
 159                 return -EINVAL;
 160         }
 161 
 162         rp->version = XPC_RP_VERSION;
 163         rp->max_npartitions = xp_max_npartitions;
 164 
 165         /* establish the actual sizes of the nasid masks */
 166         if (rp->SAL_version == 1) {
 167                 /* SAL_version 1 didn't set the nasids_size field */
 168                 rp->SAL_nasids_size = 128;
 169         }
 170         xpc_nasid_mask_nbytes = rp->SAL_nasids_size;
 171         xpc_nasid_mask_nlongs = BITS_TO_LONGS(rp->SAL_nasids_size *
 172                                               BITS_PER_BYTE);
 173 
 174         /* setup the pointers to the various items in the reserved page */
 175         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
 176         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
 177 
 178         ret = xpc_arch_ops.setup_rsvd_page(rp);
 179         if (ret != 0)
 180                 return ret;
 181 
 182         /*
 183          * Set timestamp of when reserved page was setup by XPC.
 184          * This signifies to the remote partition that our reserved
 185          * page is initialized.
 186          */
 187         new_ts_jiffies = jiffies;
 188         if (new_ts_jiffies == 0 || new_ts_jiffies == rp->ts_jiffies)
 189                 new_ts_jiffies++;
 190         rp->ts_jiffies = new_ts_jiffies;
 191 
 192         xpc_rsvd_page = rp;
 193         return 0;
 194 }
 195 
 196 void
 197 xpc_teardown_rsvd_page(void)
 198 {
 199         /* a zero timestamp indicates our rsvd page is not initialized */
 200         xpc_rsvd_page->ts_jiffies = 0;
 201 }
 202 
 203 /*
 204  * Get a copy of a portion of the remote partition's rsvd page.
 205  *
 206  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
 207  * is large enough to contain a copy of their reserved page header and
 208  * part_nasids mask.
 209  */
 210 enum xp_retval
 211 xpc_get_remote_rp(int nasid, unsigned long *discovered_nasids,
 212                   struct xpc_rsvd_page *remote_rp, unsigned long *remote_rp_pa)
 213 {
 214         int l;
 215         enum xp_retval ret;
 216 
 217         /* get the reserved page's physical address */
 218 
 219         *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
 220         if (*remote_rp_pa == 0)
 221                 return xpNoRsvdPageAddr;
 222 
 223         /* pull over the reserved page header and part_nasids mask */
 224         ret = xp_remote_memcpy(xp_pa(remote_rp), *remote_rp_pa,
 225                                XPC_RP_HEADER_SIZE + xpc_nasid_mask_nbytes);
 226         if (ret != xpSuccess)
 227                 return ret;
 228 
 229         if (discovered_nasids != NULL) {
 230                 unsigned long *remote_part_nasids =
 231                     XPC_RP_PART_NASIDS(remote_rp);
 232 
 233                 for (l = 0; l < xpc_nasid_mask_nlongs; l++)
 234                         discovered_nasids[l] |= remote_part_nasids[l];
 235         }
 236 
 237         /* zero timestamp indicates the reserved page has not been setup */
 238         if (remote_rp->ts_jiffies == 0)
 239                 return xpRsvdPageNotSet;
 240 
 241         if (XPC_VERSION_MAJOR(remote_rp->version) !=
 242             XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
 243                 return xpBadVersion;
 244         }
 245 
 246         /* check that both remote and local partids are valid for each side */
 247         if (remote_rp->SAL_partid < 0 ||
 248             remote_rp->SAL_partid >= xp_max_npartitions ||
 249             remote_rp->max_npartitions <= xp_partition_id) {
 250                 return xpInvalidPartid;
 251         }
 252 
 253         if (remote_rp->SAL_partid == xp_partition_id)
 254                 return xpLocalPartid;
 255 
 256         return xpSuccess;
 257 }
 258 
 259 /*
 260  * See if the other side has responded to a partition deactivate request
 261  * from us. Though we requested the remote partition to deactivate with regard
 262  * to us, we really only need to wait for the other side to disengage from us.
 263  */
 264 int
 265 xpc_partition_disengaged(struct xpc_partition *part)
 266 {
 267         short partid = XPC_PARTID(part);
 268         int disengaged;
 269 
 270         disengaged = !xpc_arch_ops.partition_engaged(partid);
 271         if (part->disengage_timeout) {
 272                 if (!disengaged) {
 273                         if (time_is_after_jiffies(part->disengage_timeout)) {
 274                                 /* timelimit hasn't been reached yet */
 275                                 return 0;
 276                         }
 277 
 278                         /*
 279                          * Other side hasn't responded to our deactivate
 280                          * request in a timely fashion, so assume it's dead.
 281                          */
 282 
 283                         dev_info(xpc_part, "deactivate request to remote "
 284                                  "partition %d timed out\n", partid);
 285                         xpc_disengage_timedout = 1;
 286                         xpc_arch_ops.assume_partition_disengaged(partid);
 287                         disengaged = 1;
 288                 }
 289                 part->disengage_timeout = 0;
 290 
 291                 /* cancel the timer function, provided it's not us */
 292                 if (!in_interrupt())
 293                         del_singleshot_timer_sync(&part->disengage_timer);
 294 
 295                 DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING &&
 296                         part->act_state != XPC_P_AS_INACTIVE);
 297                 if (part->act_state != XPC_P_AS_INACTIVE)
 298                         xpc_wakeup_channel_mgr(part);
 299 
 300                 xpc_arch_ops.cancel_partition_deactivation_request(part);
 301         }
 302         return disengaged;
 303 }
 304 
 305 /*
 306  * Mark specified partition as active.
 307  */
 308 enum xp_retval
 309 xpc_mark_partition_active(struct xpc_partition *part)
 310 {
 311         unsigned long irq_flags;
 312         enum xp_retval ret;
 313 
 314         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
 315 
 316         spin_lock_irqsave(&part->act_lock, irq_flags);
 317         if (part->act_state == XPC_P_AS_ACTIVATING) {
 318                 part->act_state = XPC_P_AS_ACTIVE;
 319                 ret = xpSuccess;
 320         } else {
 321                 DBUG_ON(part->reason == xpSuccess);
 322                 ret = part->reason;
 323         }
 324         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 325 
 326         return ret;
 327 }
 328 
 329 /*
 330  * Start the process of deactivating the specified partition.
 331  */
 332 void
 333 xpc_deactivate_partition(const int line, struct xpc_partition *part,
 334                          enum xp_retval reason)
 335 {
 336         unsigned long irq_flags;
 337 
 338         spin_lock_irqsave(&part->act_lock, irq_flags);
 339 
 340         if (part->act_state == XPC_P_AS_INACTIVE) {
 341                 XPC_SET_REASON(part, reason, line);
 342                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 343                 if (reason == xpReactivating) {
 344                         /* we interrupt ourselves to reactivate partition */
 345                         xpc_arch_ops.request_partition_reactivation(part);
 346                 }
 347                 return;
 348         }
 349         if (part->act_state == XPC_P_AS_DEACTIVATING) {
 350                 if ((part->reason == xpUnloading && reason != xpUnloading) ||
 351                     reason == xpReactivating) {
 352                         XPC_SET_REASON(part, reason, line);
 353                 }
 354                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 355                 return;
 356         }
 357 
 358         part->act_state = XPC_P_AS_DEACTIVATING;
 359         XPC_SET_REASON(part, reason, line);
 360 
 361         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 362 
 363         /* ask remote partition to deactivate with regard to us */
 364         xpc_arch_ops.request_partition_deactivation(part);
 365 
 366         /* set a timelimit on the disengage phase of the deactivation request */
 367         part->disengage_timeout = jiffies + (xpc_disengage_timelimit * HZ);
 368         part->disengage_timer.expires = part->disengage_timeout;
 369         add_timer(&part->disengage_timer);
 370 
 371         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
 372                 XPC_PARTID(part), reason);
 373 
 374         xpc_partition_going_down(part, reason);
 375 }
 376 
 377 /*
 378  * Mark specified partition as inactive.
 379  */
 380 void
 381 xpc_mark_partition_inactive(struct xpc_partition *part)
 382 {
 383         unsigned long irq_flags;
 384 
 385         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
 386                 XPC_PARTID(part));
 387 
 388         spin_lock_irqsave(&part->act_lock, irq_flags);
 389         part->act_state = XPC_P_AS_INACTIVE;
 390         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 391         part->remote_rp_pa = 0;
 392 }
 393 
 394 /*
 395  * SAL has provided a partition and machine mask.  The partition mask
 396  * contains a bit for each even nasid in our partition.  The machine
 397  * mask contains a bit for each even nasid in the entire machine.
 398  *
 399  * Using those two bit arrays, we can determine which nasids are
 400  * known in the machine.  Each should also have a reserved page
 401  * initialized if they are available for partitioning.
 402  */
 403 void
 404 xpc_discovery(void)
 405 {
 406         void *remote_rp_base;
 407         struct xpc_rsvd_page *remote_rp;
 408         unsigned long remote_rp_pa;
 409         int region;
 410         int region_size;
 411         int max_regions;
 412         int nasid;
 413         unsigned long *discovered_nasids;
 414         enum xp_retval ret;
 415 
 416         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
 417                                                   xpc_nasid_mask_nbytes,
 418                                                   GFP_KERNEL, &remote_rp_base);
 419         if (remote_rp == NULL)
 420                 return;
 421 
 422         discovered_nasids = kcalloc(xpc_nasid_mask_nlongs, sizeof(long),
 423                                     GFP_KERNEL);
 424         if (discovered_nasids == NULL) {
 425                 kfree(remote_rp_base);
 426                 return;
 427         }
 428 
 429         /*
 430          * The term 'region' in this context refers to the minimum number of
 431          * nodes that can comprise an access protection grouping. The access
 432          * protection is in regards to memory, IOI and IPI.
 433          */
 434         region_size = xp_region_size;
 435 
 436         if (is_uv())
 437                 max_regions = 256;
 438         else {
 439                 max_regions = 64;
 440 
 441                 switch (region_size) {
 442                 case 128:
 443                         max_regions *= 2;
 444                         /* fall through */
 445                 case 64:
 446                         max_regions *= 2;
 447                         /* fall through */
 448                 case 32:
 449                         max_regions *= 2;
 450                         region_size = 16;
 451                 }
 452         }
 453 
 454         for (region = 0; region < max_regions; region++) {
 455 
 456                 if (xpc_exiting)
 457                         break;
 458 
 459                 dev_dbg(xpc_part, "searching region %d\n", region);
 460 
 461                 for (nasid = (region * region_size * 2);
 462                      nasid < ((region + 1) * region_size * 2); nasid += 2) {
 463 
 464                         if (xpc_exiting)
 465                                 break;
 466 
 467                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
 468 
 469                         if (test_bit(nasid / 2, xpc_part_nasids)) {
 470                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
 471                                         "part of the local partition; skipping "
 472                                         "region\n", nasid);
 473                                 break;
 474                         }
 475 
 476                         if (!(test_bit(nasid / 2, xpc_mach_nasids))) {
 477                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
 478                                         "not on Numa-Link network at reset\n",
 479                                         nasid);
 480                                 continue;
 481                         }
 482 
 483                         if (test_bit(nasid / 2, discovered_nasids)) {
 484                                 dev_dbg(xpc_part, "Nasid %d is part of a "
 485                                         "partition which was previously "
 486                                         "discovered\n", nasid);
 487                                 continue;
 488                         }
 489 
 490                         /* pull over the rsvd page header & part_nasids mask */
 491 
 492                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
 493                                                 remote_rp, &remote_rp_pa);
 494                         if (ret != xpSuccess) {
 495                                 dev_dbg(xpc_part, "unable to get reserved page "
 496                                         "from nasid %d, reason=%d\n", nasid,
 497                                         ret);
 498 
 499                                 if (ret == xpLocalPartid)
 500                                         break;
 501 
 502                                 continue;
 503                         }
 504 
 505                         xpc_arch_ops.request_partition_activation(remote_rp,
 506                                                          remote_rp_pa, nasid);
 507                 }
 508         }
 509 
 510         kfree(discovered_nasids);
 511         kfree(remote_rp_base);
 512 }
 513 
 514 /*
 515  * Given a partid, get the nasids owned by that partition from the
 516  * remote partition's reserved page.
 517  */
 518 enum xp_retval
 519 xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
 520 {
 521         struct xpc_partition *part;
 522         unsigned long part_nasid_pa;
 523 
 524         part = &xpc_partitions[partid];
 525         if (part->remote_rp_pa == 0)
 526                 return xpPartitionDown;
 527 
 528         memset(nasid_mask, 0, xpc_nasid_mask_nbytes);
 529 
 530         part_nasid_pa = (unsigned long)XPC_RP_PART_NASIDS(part->remote_rp_pa);
 531 
 532         return xp_remote_memcpy(xp_pa(nasid_mask), part_nasid_pa,
 533                                 xpc_nasid_mask_nbytes);
 534 }