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 <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 = buf;
  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                 /* !!! L1_CACHE_ALIGN() is only a sn2-bte_copy requirement */
  97                 if (is_shub())
  98                         len = L1_CACHE_ALIGN(len);
  99
 100                 if (len > buf_len) {
 101                         if (buf_base != NULL)
 102                                 kfree(buf_base);
 103                         buf_len = L1_CACHE_ALIGN(len);
 104                         buf = xpc_kmalloc_cacheline_aligned(buf_len, GFP_KERNEL,
 105                                                             &buf_base);
 106                         if (buf_base == NULL) {
 107                                 dev_err(xpc_part, "unable to kmalloc "
 108                                         "len=0x%016lx\n", buf_len);
 109                                 ret = xpNoMemory;
 110                                 break;
 111                         }
 112                 }
 113
 114                 ret = xp_remote_memcpy(xp_pa(buf), rp_pa, len);
 115                 if (ret != xpSuccess) {
 116                         dev_dbg(xpc_part, "xp_remote_memcpy failed %d\n", ret);
 117                         break;
 118                 }
 119         }
 120
 121         kfree(buf_base);
 122
 123         if (ret != xpSuccess)
 124                 rp_pa = 0;
 125
 126         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
 127         return rp_pa;
 128 }
 129
 130 /*
 131  * Fill the partition reserved page with the information needed by
 132  * other partitions to discover we are alive and establish initial
 133  * communications.
 134  */
 135 int
 136 xpc_setup_rsvd_page(void)
 137 {
 138         int ret;
 139         struct xpc_rsvd_page *rp;
 140         unsigned long rp_pa;
 141         unsigned long new_ts_jiffies;
 142
 143         /* get the local reserved page's address */
 144
 145         preempt_disable();
 146         rp_pa = xpc_get_rsvd_page_pa(xp_cpu_to_nasid(smp_processor_id()));
 147         preempt_enable();
 148         if (rp_pa == 0) {
 149                 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
 150                 return -ESRCH;
 151         }
 152         rp = (struct xpc_rsvd_page *)__va(xp_socket_pa(rp_pa));
 153
 154         if (rp->SAL_version < 3) {
 155                 /* SAL_versions < 3 had a SAL_partid defined as a u8 */
 156                 rp->SAL_partid &= 0xff;
 157         }
 158         BUG_ON(rp->SAL_partid != xp_partition_id);
 159
 160         if (rp->SAL_partid < 0 || rp->SAL_partid >= xp_max_npartitions) {
 161                 dev_err(xpc_part, "the reserved page's partid of %d is outside "
 162                         "supported range (< 0 || >= %d)\n", rp->SAL_partid,
 163                         xp_max_npartitions);
 164                 return -EINVAL;
 165         }
 166
 167         rp->version = XPC_RP_VERSION;
 168         rp->max_npartitions = xp_max_npartitions;
 169
 170         /* establish the actual sizes of the nasid masks */
 171         if (rp->SAL_version == 1) {
 172                 /* SAL_version 1 didn't set the nasids_size field */
 173                 rp->SAL_nasids_size = 128;
 174         }
 175         xpc_nasid_mask_nbytes = rp->SAL_nasids_size;
 176         xpc_nasid_mask_nlongs = BITS_TO_LONGS(rp->SAL_nasids_size *
 177                                               BITS_PER_BYTE);
 178
 179         /* setup the pointers to the various items in the reserved page */
 180         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
 181         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
 182
 183         ret = xpc_arch_ops.setup_rsvd_page(rp);
 184         if (ret != 0)
 185                 return ret;
 186
 187         /*
 188          * Set timestamp of when reserved page was setup by XPC.
 189          * This signifies to the remote partition that our reserved
 190          * page is initialized.
 191          */
 192         new_ts_jiffies = jiffies;
 193         if (new_ts_jiffies == 0 || new_ts_jiffies == rp->ts_jiffies)
 194                 new_ts_jiffies++;
 195         rp->ts_jiffies = new_ts_jiffies;
 196
 197         xpc_rsvd_page = rp;
 198         return 0;
 199 }
 200
 201 void
 202 xpc_teardown_rsvd_page(void)
 203 {
 204         /* a zero timestamp indicates our rsvd page is not initialized */
 205         xpc_rsvd_page->ts_jiffies = 0;
 206 }
 207
 208 /*
 209  * Get a copy of a portion of the remote partition's rsvd page.
 210  *
 211  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
 212  * is large enough to contain a copy of their reserved page header and
 213  * part_nasids mask.
 214  */
 215 enum xp_retval
 216 xpc_get_remote_rp(int nasid, unsigned long *discovered_nasids,
 217                   struct xpc_rsvd_page *remote_rp, unsigned long *remote_rp_pa)
 218 {
 219         int l;
 220         enum xp_retval ret;
 221
 222         /* get the reserved page's physical address */
 223
 224         *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
 225         if (*remote_rp_pa == 0)
 226                 return xpNoRsvdPageAddr;
 227
 228         /* pull over the reserved page header and part_nasids mask */
 229         ret = xp_remote_memcpy(xp_pa(remote_rp), *remote_rp_pa,
 230                                XPC_RP_HEADER_SIZE + xpc_nasid_mask_nbytes);
 231         if (ret != xpSuccess)
 232                 return ret;
 233
 234         if (discovered_nasids != NULL) {
 235                 unsigned long *remote_part_nasids =
 236                     XPC_RP_PART_NASIDS(remote_rp);
 237
 238                 for (l = 0; l < xpc_nasid_mask_nlongs; l++)
 239                         discovered_nasids[l] |= remote_part_nasids[l];
 240         }
 241
 242         /* zero timestamp indicates the reserved page has not been setup */
 243         if (remote_rp->ts_jiffies == 0)
 244                 return xpRsvdPageNotSet;
 245
 246         if (XPC_VERSION_MAJOR(remote_rp->version) !=
 247             XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
 248                 return xpBadVersion;
 249         }
 250
 251         /* check that both remote and local partids are valid for each side */
 252         if (remote_rp->SAL_partid < 0 ||
 253             remote_rp->SAL_partid >= xp_max_npartitions ||
 254             remote_rp->max_npartitions <= xp_partition_id) {
 255                 return xpInvalidPartid;
 256         }
 257
 258         if (remote_rp->SAL_partid == xp_partition_id)
 259                 return xpLocalPartid;
 260
 261         return xpSuccess;
 262 }
 263
 264 /*
 265  * See if the other side has responded to a partition deactivate request
 266  * from us. Though we requested the remote partition to deactivate with regard
 267  * to us, we really only need to wait for the other side to disengage from us.
 268  */
 269 int
 270 xpc_partition_disengaged(struct xpc_partition *part)
 271 {
 272         short partid = XPC_PARTID(part);
 273         int disengaged;
 274
 275         disengaged = !xpc_arch_ops.partition_engaged(partid);
 276         if (part->disengage_timeout) {
 277                 if (!disengaged) {
 278                         if (time_is_after_jiffies(part->disengage_timeout)) {
 279                                 /* timelimit hasn't been reached yet */
 280                                 return 0;
 281                         }
 282
 283                         /*
 284                          * Other side hasn't responded to our deactivate
 285                          * request in a timely fashion, so assume it's dead.
 286                          */
 287
 288                         dev_info(xpc_part, "deactivate request to remote "
 289                                  "partition %d timed out\n", partid);
 290                         xpc_disengage_timedout = 1;
 291                         xpc_arch_ops.assume_partition_disengaged(partid);
 292                         disengaged = 1;
 293                 }
 294                 part->disengage_timeout = 0;
 295
 296                 /* cancel the timer function, provided it's not us */
 297                 if (!in_interrupt())
 298                         del_singleshot_timer_sync(&part->disengage_timer);
 299
 300                 DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING &&
 301                         part->act_state != XPC_P_AS_INACTIVE);
 302                 if (part->act_state != XPC_P_AS_INACTIVE)
 303                         xpc_wakeup_channel_mgr(part);
 304
 305                 xpc_arch_ops.cancel_partition_deactivation_request(part);
 306         }
 307         return disengaged;
 308 }
 309
 310 /*
 311  * Mark specified partition as active.
 312  */
 313 enum xp_retval
 314 xpc_mark_partition_active(struct xpc_partition *part)
 315 {
 316         unsigned long irq_flags;
 317         enum xp_retval ret;
 318
 319         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
 320
 321         spin_lock_irqsave(&part->act_lock, irq_flags);
 322         if (part->act_state == XPC_P_AS_ACTIVATING) {
 323                 part->act_state = XPC_P_AS_ACTIVE;
 324                 ret = xpSuccess;
 325         } else {
 326                 DBUG_ON(part->reason == xpSuccess);
 327                 ret = part->reason;
 328         }
 329         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 330
 331         return ret;
 332 }
 333
 334 /*
 335  * Start the process of deactivating the specified partition.
 336  */
 337 void
 338 xpc_deactivate_partition(const int line, struct xpc_partition *part,
 339                          enum xp_retval reason)
 340 {
 341         unsigned long irq_flags;
 342
 343         spin_lock_irqsave(&part->act_lock, irq_flags);
 344
 345         if (part->act_state == XPC_P_AS_INACTIVE) {
 346                 XPC_SET_REASON(part, reason, line);
 347                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 348                 if (reason == xpReactivating) {
 349                         /* we interrupt ourselves to reactivate partition */
 350                         xpc_arch_ops.request_partition_reactivation(part);
 351                 }
 352                 return;
 353         }
 354         if (part->act_state == XPC_P_AS_DEACTIVATING) {
 355                 if ((part->reason == xpUnloading && reason != xpUnloading) ||
 356                     reason == xpReactivating) {
 357                         XPC_SET_REASON(part, reason, line);
 358                 }
 359                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
 360                 return;
 361         }
 362
 363         part->act_state = XPC_P_AS_DEACTIVATING;
 364         XPC_SET_REASON(part, reason, line);
 365
 366         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 367
 368         /* ask remote partition to deactivate with regard to us */
 369         xpc_arch_ops.request_partition_deactivation(part);
 370
 371         /* set a timelimit on the disengage phase of the deactivation request */
 372         part->disengage_timeout = jiffies + (xpc_disengage_timelimit * HZ);
 373         part->disengage_timer.expires = part->disengage_timeout;
 374         add_timer(&part->disengage_timer);
 375
 376         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
 377                 XPC_PARTID(part), reason);
 378
 379         xpc_partition_going_down(part, reason);
 380 }
 381
 382 /*
 383  * Mark specified partition as inactive.
 384  */
 385 void
 386 xpc_mark_partition_inactive(struct xpc_partition *part)
 387 {
 388         unsigned long irq_flags;
 389
 390         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
 391                 XPC_PARTID(part));
 392
 393         spin_lock_irqsave(&part->act_lock, irq_flags);
 394         part->act_state = XPC_P_AS_INACTIVE;
 395         spin_unlock_irqrestore(&part->act_lock, irq_flags);
 396         part->remote_rp_pa = 0;
 397 }
 398
 399 /*
 400  * SAL has provided a partition and machine mask.  The partition mask
 401  * contains a bit for each even nasid in our partition.  The machine
 402  * mask contains a bit for each even nasid in the entire machine.
 403  *
 404  * Using those two bit arrays, we can determine which nasids are
 405  * known in the machine.  Each should also have a reserved page
 406  * initialized if they are available for partitioning.
 407  */
 408 void
 409 xpc_discovery(void)
 410 {
 411         void *remote_rp_base;
 412         struct xpc_rsvd_page *remote_rp;
 413         unsigned long remote_rp_pa;
 414         int region;
 415         int region_size;
 416         int max_regions;
 417         int nasid;
 418         struct xpc_rsvd_page *rp;
 419         unsigned long *discovered_nasids;
 420         enum xp_retval ret;
 421
 422         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
 423                                                   xpc_nasid_mask_nbytes,
 424                                                   GFP_KERNEL, &remote_rp_base);
 425         if (remote_rp == NULL)
 426                 return;
 427
 428         discovered_nasids = kzalloc(sizeof(long) * xpc_nasid_mask_nlongs,
 429                                     GFP_KERNEL);
 430         if (discovered_nasids == NULL) {
 431                 kfree(remote_rp_base);
 432                 return;
 433         }
 434
 435         rp = (struct xpc_rsvd_page *)xpc_rsvd_page;
 436
 437         /*
 438          * The term 'region' in this context refers to the minimum number of
 439          * nodes that can comprise an access protection grouping. The access
 440          * protection is in regards to memory, IOI and IPI.
 441          */
 442         max_regions = 64;
 443         region_size = xp_region_size;
 444
 445         switch (region_size) {
 446         case 128:
 447                 max_regions *= 2;
 448         case 64:
 449                 max_regions *= 2;
 450         case 32:
 451                 max_regions *= 2;
 452                 region_size = 16;
 453                 DBUG_ON(!is_shub2());
 454         }
 455
 456         for (region = 0; region < max_regions; region++) {
 457
 458                 if (xpc_exiting)
 459                         break;
 460
 461                 dev_dbg(xpc_part, "searching region %d\n", region);
 462
 463                 for (nasid = (region * region_size * 2);
 464                      nasid < ((region + 1) * region_size * 2); nasid += 2) {
 465
 466                         if (xpc_exiting)
 467                                 break;
 468
 469                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
 470
 471                         if (test_bit(nasid / 2, xpc_part_nasids)) {
 472                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
 473                                         "part of the local partition; skipping "
 474                                         "region\n", nasid);
 475                                 break;
 476                         }
 477
 478                         if (!(test_bit(nasid / 2, xpc_mach_nasids))) {
 479                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
 480                                         "not on Numa-Link network at reset\n",
 481                                         nasid);
 482                                 continue;
 483                         }
 484
 485                         if (test_bit(nasid / 2, discovered_nasids)) {
 486                                 dev_dbg(xpc_part, "Nasid %d is part of a "
 487                                         "partition which was previously "
 488                                         "discovered\n", nasid);
 489                                 continue;
 490                         }
 491
 492                         /* pull over the rsvd page header & part_nasids mask */
 493
 494                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
 495                                                 remote_rp, &remote_rp_pa);
 496                         if (ret != xpSuccess) {
 497                                 dev_dbg(xpc_part, "unable to get reserved page "
 498                                         "from nasid %d, reason=%d\n", nasid,
 499                                         ret);
 500
 501                                 if (ret == xpLocalPartid)
 502                                         break;
 503
 504                                 continue;
 505                         }
 506
 507                         xpc_arch_ops.request_partition_activation(remote_rp,
 508                                                          remote_rp_pa, nasid);
 509                 }
 510         }
 511
 512         kfree(discovered_nasids);
 513         kfree(remote_rp_base);
 514 }
 515
 516 /*
 517  * Given a partid, get the nasids owned by that partition from the
 518  * remote partition's reserved page.
 519  */
 520 enum xp_retval
 521 xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
 522 {
 523         struct xpc_partition *part;
 524         unsigned long part_nasid_pa;
 525
 526         part = &xpc_partitions[partid];
 527         if (part->remote_rp_pa == 0)
 528                 return xpPartitionDown;
 529
 530         memset(nasid_mask, 0, xpc_nasid_mask_nbytes);
 531
 532         part_nasid_pa = (unsigned long)XPC_RP_PART_NASIDS(part->remote_rp_pa);
 533
 534         return xp_remote_memcpy(xp_pa(nasid_mask), part_nasid_pa,
 535                                 xpc_nasid_mask_nbytes);
 536 }