72ef330fb78494922cc0dc7b6bf2c625a55aeff8
[linux-3.10.git] / arch / ia64 / sn / kernel / 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) 2004-2005 Silicon Graphics, Inc.  All Rights Reserved.
7  */
8
9
10 /*
11  * Cross Partition Communication (XPC) partition support.
12  *
13  *      This is the part of XPC that detects the presence/absence of
14  *      other partitions. It provides a heartbeat and monitors the
15  *      heartbeats of other partitions.
16  *
17  */
18
19
20 #include <linux/kernel.h>
21 #include <linux/sysctl.h>
22 #include <linux/cache.h>
23 #include <linux/mmzone.h>
24 #include <linux/nodemask.h>
25 #include <asm/uncached.h>
26 #include <asm/sn/bte.h>
27 #include <asm/sn/intr.h>
28 #include <asm/sn/sn_sal.h>
29 #include <asm/sn/nodepda.h>
30 #include <asm/sn/addrs.h>
31 #include "xpc.h"
32
33
34 /* XPC is exiting flag */
35 int xpc_exiting;
36
37
38 /* SH_IPI_ACCESS shub register value on startup */
39 static u64 xpc_sh1_IPI_access;
40 static u64 xpc_sh2_IPI_access0;
41 static u64 xpc_sh2_IPI_access1;
42 static u64 xpc_sh2_IPI_access2;
43 static u64 xpc_sh2_IPI_access3;
44
45
46 /* original protection values for each node */
47 u64 xpc_prot_vec[MAX_NUMNODES];
48
49
50 /* this partition's reserved page */
51 struct xpc_rsvd_page *xpc_rsvd_page;
52
53 /* this partition's XPC variables (within the reserved page) */
54 struct xpc_vars *xpc_vars;
55 struct xpc_vars_part *xpc_vars_part;
56
57
58 /*
59  * For performance reasons, each entry of xpc_partitions[] is cacheline
60  * aligned. And xpc_partitions[] is padded with an additional entry at the
61  * end so that the last legitimate entry doesn't share its cacheline with
62  * another variable.
63  */
64 struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
65
66
67 /*
68  * Generic buffer used to store a local copy of the remote partitions
69  * reserved page or XPC variables.
70  *
71  * xpc_discovery runs only once and is a seperate thread that is
72  * very likely going to be processing in parallel with receiving
73  * interrupts.
74  */
75 char ____cacheline_aligned
76                 xpc_remote_copy_buffer[XPC_RSVD_PAGE_ALIGNED_SIZE];
77
78
79 /* systune related variables */
80 int xpc_hb_interval = XPC_HB_DEFAULT_INTERVAL;
81 int xpc_hb_check_interval = XPC_HB_CHECK_DEFAULT_TIMEOUT;
82
83
84 /*
85  * Given a nasid, get the physical address of the  partition's reserved page
86  * for that nasid. This function returns 0 on any error.
87  */
88 static u64
89 xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
90 {
91         bte_result_t bte_res;
92         s64 status;
93         u64 cookie = 0;
94         u64 rp_pa = nasid;      /* seed with nasid */
95         u64 len = 0;
96
97
98         while (1) {
99
100                 status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
101                                                                 &len);
102
103                 dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
104                         "0x%016lx, address=0x%016lx, len=0x%016lx\n",
105                         status, cookie, rp_pa, len);
106
107                 if (status != SALRET_MORE_PASSES) {
108                         break;
109                 }
110
111                 if (len > buf_size) {
112                         dev_err(xpc_part, "len (=0x%016lx) > buf_size\n", len);
113                         status = SALRET_ERROR;
114                         break;
115                 }
116
117                 bte_res = xp_bte_copy(rp_pa, ia64_tpa(buf), buf_size,
118                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
119                 if (bte_res != BTE_SUCCESS) {
120                         dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
121                         status = SALRET_ERROR;
122                         break;
123                 }
124         }
125
126         if (status != SALRET_OK) {
127                 rp_pa = 0;
128         }
129         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
130         return rp_pa;
131 }
132
133
134 /*
135  * Fill the partition reserved page with the information needed by
136  * other partitions to discover we are alive and establish initial
137  * communications.
138  */
139 struct xpc_rsvd_page *
140 xpc_rsvd_page_init(void)
141 {
142         struct xpc_rsvd_page *rp;
143         AMO_t *amos_page;
144         u64 rp_pa, next_cl, nasid_array = 0;
145         int i, ret;
146
147
148         /* get the local reserved page's address */
149
150         rp_pa = xpc_get_rsvd_page_pa(cnodeid_to_nasid(0),
151                                         (u64) xpc_remote_copy_buffer,
152                                                 XPC_RSVD_PAGE_ALIGNED_SIZE);
153         if (rp_pa == 0) {
154                 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
155                 return NULL;
156         }
157         rp = (struct xpc_rsvd_page *) __va(rp_pa);
158
159         if (rp->partid != sn_partition_id) {
160                 dev_err(xpc_part, "the reserved page's partid of %d should be "
161                         "%d\n", rp->partid, sn_partition_id);
162                 return NULL;
163         }
164
165         rp->version = XPC_RP_VERSION;
166
167         /*
168          * Place the XPC variables on the cache line following the
169          * reserved page structure.
170          */
171         next_cl = (u64) rp + XPC_RSVD_PAGE_ALIGNED_SIZE;
172         xpc_vars = (struct xpc_vars *) next_cl;
173
174         /*
175          * Before clearing xpc_vars, see if a page of AMOs had been previously
176          * allocated. If not we'll need to allocate one and set permissions
177          * so that cross-partition AMOs are allowed.
178          *
179          * The allocated AMO page needs MCA reporting to remain disabled after
180          * XPC has unloaded.  To make this work, we keep a copy of the pointer
181          * to this page (i.e., amos_page) in the struct xpc_vars structure,
182          * which is pointed to by the reserved page, and re-use that saved copy
183          * on subsequent loads of XPC. This AMO page is never freed, and its
184          * memory protections are never restricted.
185          */
186         if ((amos_page = xpc_vars->amos_page) == NULL) {
187                 amos_page = (AMO_t *) TO_AMO(uncached_alloc_page(0));
188                 if (amos_page == NULL) {
189                         dev_err(xpc_part, "can't allocate page of AMOs\n");
190                         return NULL;
191                 }
192
193                 /*
194                  * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
195                  * when xpc_allow_IPI_ops() is called via xpc_hb_init().
196                  */
197                 if (!enable_shub_wars_1_1()) {
198                         ret = sn_change_memprotect(ia64_tpa((u64) amos_page),
199                                         PAGE_SIZE, SN_MEMPROT_ACCESS_CLASS_1,
200                                         &nasid_array);
201                         if (ret != 0) {
202                                 dev_err(xpc_part, "can't change memory "
203                                         "protections\n");
204                                 uncached_free_page(__IA64_UNCACHED_OFFSET |
205                                                    TO_PHYS((u64) amos_page));
206                                 return NULL;
207                         }
208                 }
209         } else if (!IS_AMO_ADDRESS((u64) amos_page)) {
210                 /*
211                  * EFI's XPBOOT can also set amos_page in the reserved page,
212                  * but it happens to leave it as an uncached physical address
213                  * and we need it to be an uncached virtual, so we'll have to
214                  * convert it.
215                  */
216                 if (!IS_AMO_PHYS_ADDRESS((u64) amos_page)) {
217                         dev_err(xpc_part, "previously used amos_page address "
218                                 "is bad = 0x%p\n", (void *) amos_page);
219                         return NULL;
220                 }
221                 amos_page = (AMO_t *) TO_AMO((u64) amos_page);
222         }
223
224         memset(xpc_vars, 0, sizeof(struct xpc_vars));
225
226         /*
227          * Place the XPC per partition specific variables on the cache line
228          * following the XPC variables structure.
229          */
230         next_cl += XPC_VARS_ALIGNED_SIZE;
231         memset((u64 *) next_cl, 0, sizeof(struct xpc_vars_part) *
232                                                         XP_MAX_PARTITIONS);
233         xpc_vars_part = (struct xpc_vars_part *) next_cl;
234         xpc_vars->vars_part_pa = __pa(next_cl);
235
236         xpc_vars->version = XPC_V_VERSION;
237         xpc_vars->act_nasid = cpuid_to_nasid(0);
238         xpc_vars->act_phys_cpuid = cpu_physical_id(0);
239         xpc_vars->amos_page = amos_page;  /* save for next load of XPC */
240
241
242         /*
243          * Initialize the activation related AMO variables.
244          */
245         xpc_vars->act_amos = xpc_IPI_init(XP_MAX_PARTITIONS);
246         for (i = 1; i < XP_NASID_MASK_WORDS; i++) {
247                 xpc_IPI_init(i + XP_MAX_PARTITIONS);
248         }
249         /* export AMO page's physical address to other partitions */
250         xpc_vars->amos_page_pa = ia64_tpa((u64) xpc_vars->amos_page);
251
252         /*
253          * This signifies to the remote partition that our reserved
254          * page is initialized.
255          */
256         rp->vars_pa = __pa(xpc_vars);
257
258         return rp;
259 }
260
261
262 /*
263  * Change protections to allow IPI operations (and AMO operations on
264  * Shub 1.1 systems).
265  */
266 void
267 xpc_allow_IPI_ops(void)
268 {
269         int node;
270         int nasid;
271
272
273         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
274
275         if (is_shub2()) {
276                 xpc_sh2_IPI_access0 =
277                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
278                 xpc_sh2_IPI_access1 =
279                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
280                 xpc_sh2_IPI_access2 =
281                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
282                 xpc_sh2_IPI_access3 =
283                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
284
285                 for_each_online_node(node) {
286                         nasid = cnodeid_to_nasid(node);
287                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
288                                                                 -1UL);
289                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
290                                                                 -1UL);
291                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
292                                                                 -1UL);
293                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
294                                                                 -1UL);
295                 }
296
297         } else {
298                 xpc_sh1_IPI_access =
299                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
300
301                 for_each_online_node(node) {
302                         nasid = cnodeid_to_nasid(node);
303                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
304                                                                 -1UL);
305
306                         /*
307                          * Since the BIST collides with memory operations on
308                          * SHUB 1.1 sn_change_memprotect() cannot be used.
309                          */
310                         if (enable_shub_wars_1_1()) {
311                                 /* open up everything */
312                                 xpc_prot_vec[node] = (u64) HUB_L((u64 *)
313                                                 GLOBAL_MMR_ADDR(nasid,
314                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0));
315                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
316                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
317                                                                 -1UL);
318                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
319                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
320                                                                 -1UL);
321                         }
322                 }
323         }
324 }
325
326
327 /*
328  * Restrict protections to disallow IPI operations (and AMO operations on
329  * Shub 1.1 systems).
330  */
331 void
332 xpc_restrict_IPI_ops(void)
333 {
334         int node;
335         int nasid;
336
337
338         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
339
340         if (is_shub2()) {
341
342                 for_each_online_node(node) {
343                         nasid = cnodeid_to_nasid(node);
344                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
345                                                         xpc_sh2_IPI_access0);
346                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
347                                                         xpc_sh2_IPI_access1);
348                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
349                                                         xpc_sh2_IPI_access2);
350                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
351                                                         xpc_sh2_IPI_access3);
352                 }
353
354         } else {
355
356                 for_each_online_node(node) {
357                         nasid = cnodeid_to_nasid(node);
358                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
359                                                         xpc_sh1_IPI_access);
360
361                         if (enable_shub_wars_1_1()) {
362                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
363                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
364                                                         xpc_prot_vec[node]);
365                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
366                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
367                                                         xpc_prot_vec[node]);
368                         }
369                 }
370         }
371 }
372
373
374 /*
375  * At periodic intervals, scan through all active partitions and ensure
376  * their heartbeat is still active.  If not, the partition is deactivated.
377  */
378 void
379 xpc_check_remote_hb(void)
380 {
381         struct xpc_vars *remote_vars;
382         struct xpc_partition *part;
383         partid_t partid;
384         bte_result_t bres;
385
386
387         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
388
389         for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
390                 if (partid == sn_partition_id) {
391                         continue;
392                 }
393
394                 part = &xpc_partitions[partid];
395
396                 if (part->act_state == XPC_P_INACTIVE ||
397                                 part->act_state == XPC_P_DEACTIVATING) {
398                         continue;
399                 }
400
401                 /* pull the remote_hb cache line */
402                 bres = xp_bte_copy(part->remote_vars_pa,
403                                         ia64_tpa((u64) remote_vars),
404                                         XPC_VARS_ALIGNED_SIZE,
405                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
406                 if (bres != BTE_SUCCESS) {
407                         XPC_DEACTIVATE_PARTITION(part,
408                                                 xpc_map_bte_errors(bres));
409                         continue;
410                 }
411
412                 dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
413                         " = %ld, kdb_status = %ld, HB_mask = 0x%lx\n", partid,
414                         remote_vars->heartbeat, part->last_heartbeat,
415                         remote_vars->kdb_status,
416                         remote_vars->heartbeating_to_mask);
417
418                 if (((remote_vars->heartbeat == part->last_heartbeat) &&
419                         (remote_vars->kdb_status == 0)) ||
420                              !XPC_HB_ALLOWED(sn_partition_id, remote_vars)) {
421
422                         XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
423                         continue;
424                 }
425
426                 part->last_heartbeat = remote_vars->heartbeat;
427         }
428 }
429
430
431 /*
432  * Get a copy of the remote partition's rsvd page.
433  *
434  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
435  * assumed to be of size XPC_RSVD_PAGE_ALIGNED_SIZE.
436  */
437 static enum xpc_retval
438 xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
439                 struct xpc_rsvd_page *remote_rp, u64 *remote_rsvd_page_pa)
440 {
441         int bres, i;
442
443
444         /* get the reserved page's physical address */
445
446         *remote_rsvd_page_pa = xpc_get_rsvd_page_pa(nasid, (u64) remote_rp,
447                                                 XPC_RSVD_PAGE_ALIGNED_SIZE);
448         if (*remote_rsvd_page_pa == 0) {
449                 return xpcNoRsvdPageAddr;
450         }
451
452
453         /* pull over the reserved page structure */
454
455         bres = xp_bte_copy(*remote_rsvd_page_pa, ia64_tpa((u64) remote_rp),
456                                 XPC_RSVD_PAGE_ALIGNED_SIZE,
457                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
458         if (bres != BTE_SUCCESS) {
459                 return xpc_map_bte_errors(bres);
460         }
461
462
463         if (discovered_nasids != NULL) {
464                 for (i = 0; i < XP_NASID_MASK_WORDS; i++) {
465                         discovered_nasids[i] |= remote_rp->part_nasids[i];
466                 }
467         }
468
469
470         /* check that the partid is for another partition */
471
472         if (remote_rp->partid < 1 ||
473                                 remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
474                 return xpcInvalidPartid;
475         }
476
477         if (remote_rp->partid == sn_partition_id) {
478                 return xpcLocalPartid;
479         }
480
481
482         if (XPC_VERSION_MAJOR(remote_rp->version) !=
483                                         XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
484                 return xpcBadVersion;
485         }
486
487         return xpcSuccess;
488 }
489
490
491 /*
492  * Get a copy of the remote partition's XPC variables.
493  *
494  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
495  * assumed to be of size XPC_VARS_ALIGNED_SIZE.
496  */
497 static enum xpc_retval
498 xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
499 {
500         int bres;
501
502
503         if (remote_vars_pa == 0) {
504                 return xpcVarsNotSet;
505         }
506
507
508         /* pull over the cross partition variables */
509
510         bres = xp_bte_copy(remote_vars_pa, ia64_tpa((u64) remote_vars),
511                                 XPC_VARS_ALIGNED_SIZE,
512                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
513         if (bres != BTE_SUCCESS) {
514                 return xpc_map_bte_errors(bres);
515         }
516
517         if (XPC_VERSION_MAJOR(remote_vars->version) !=
518                                         XPC_VERSION_MAJOR(XPC_V_VERSION)) {
519                 return xpcBadVersion;
520         }
521
522         return xpcSuccess;
523 }
524
525
526 /*
527  * Prior code has determine the nasid which generated an IPI.  Inspect
528  * that nasid to determine if its partition needs to be activated or
529  * deactivated.
530  *
531  * A partition is consider "awaiting activation" if our partition
532  * flags indicate it is not active and it has a heartbeat.  A
533  * partition is considered "awaiting deactivation" if our partition
534  * flags indicate it is active but it has no heartbeat or it is not
535  * sending its heartbeat to us.
536  *
537  * To determine the heartbeat, the remote nasid must have a properly
538  * initialized reserved page.
539  */
540 static void
541 xpc_identify_act_IRQ_req(int nasid)
542 {
543         struct xpc_rsvd_page *remote_rp;
544         struct xpc_vars *remote_vars;
545         u64 remote_rsvd_page_pa;
546         u64 remote_vars_pa;
547         partid_t partid;
548         struct xpc_partition *part;
549         enum xpc_retval ret;
550
551
552         /* pull over the reserved page structure */
553
554         remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;
555
556         ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rsvd_page_pa);
557         if (ret != xpcSuccess) {
558                 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
559                         "which sent interrupt, reason=%d\n", nasid, ret);
560                 return;
561         }
562
563         remote_vars_pa = remote_rp->vars_pa;
564         partid = remote_rp->partid;
565         part = &xpc_partitions[partid];
566
567
568         /* pull over the cross partition variables */
569
570         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
571
572         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
573         if (ret != xpcSuccess) {
574
575                 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
576                         "which sent interrupt, reason=%d\n", nasid, ret);
577
578                 XPC_DEACTIVATE_PARTITION(part, ret);
579                 return;
580         }
581
582
583         part->act_IRQ_rcvd++;
584
585         dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
586                 "%ld:0x%lx\n", (int) nasid, (int) partid, part->act_IRQ_rcvd,
587                 remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
588
589
590         if (part->act_state == XPC_P_INACTIVE) {
591
592                 part->remote_rp_pa = remote_rsvd_page_pa;
593                 dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n",
594                         part->remote_rp_pa);
595
596                 part->remote_vars_pa = remote_vars_pa;
597                 dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
598                         part->remote_vars_pa);
599
600                 part->last_heartbeat = remote_vars->heartbeat;
601                 dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
602                         part->last_heartbeat);
603
604                 part->remote_vars_part_pa = remote_vars->vars_part_pa;
605                 dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
606                         part->remote_vars_part_pa);
607
608                 part->remote_act_nasid = remote_vars->act_nasid;
609                 dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
610                         part->remote_act_nasid);
611
612                 part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
613                 dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
614                         part->remote_act_phys_cpuid);
615
616                 part->remote_amos_page_pa = remote_vars->amos_page_pa;
617                 dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
618                         part->remote_amos_page_pa);
619
620                 xpc_activate_partition(part);
621
622         } else if (part->remote_amos_page_pa != remote_vars->amos_page_pa ||
623                         !XPC_HB_ALLOWED(sn_partition_id, remote_vars)) {
624
625                 part->reactivate_nasid = nasid;
626                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
627         }
628 }
629
630
631 /*
632  * Loop through the activation AMO variables and process any bits
633  * which are set.  Each bit indicates a nasid sending a partition
634  * activation or deactivation request.
635  *
636  * Return #of IRQs detected.
637  */
638 int
639 xpc_identify_act_IRQ_sender(void)
640 {
641         int word, bit;
642         u64 nasid_mask;
643         u64 nasid;                      /* remote nasid */
644         int n_IRQs_detected = 0;
645         AMO_t *act_amos;
646         struct xpc_rsvd_page *rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
647
648
649         act_amos = xpc_vars->act_amos;
650
651
652         /* scan through act AMO variable looking for non-zero entries */
653         for (word = 0; word < XP_NASID_MASK_WORDS; word++) {
654
655                 nasid_mask = xpc_IPI_receive(&act_amos[word]);
656                 if (nasid_mask == 0) {
657                         /* no IRQs from nasids in this variable */
658                         continue;
659                 }
660
661                 dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
662                         nasid_mask);
663
664
665                 /*
666                  * If this nasid has been added to the machine since
667                  * our partition was reset, this will retain the
668                  * remote nasid in our reserved pages machine mask.
669                  * This is used in the event of module reload.
670                  */
671                 rp->mach_nasids[word] |= nasid_mask;
672
673
674                 /* locate the nasid(s) which sent interrupts */
675
676                 for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
677                         if (nasid_mask & (1UL << bit)) {
678                                 n_IRQs_detected++;
679                                 nasid = XPC_NASID_FROM_W_B(word, bit);
680                                 dev_dbg(xpc_part, "interrupt from nasid %ld\n",
681                                         nasid);
682                                 xpc_identify_act_IRQ_req(nasid);
683                         }
684                 }
685         }
686         return n_IRQs_detected;
687 }
688
689
690 /*
691  * Mark specified partition as active.
692  */
693 enum xpc_retval
694 xpc_mark_partition_active(struct xpc_partition *part)
695 {
696         unsigned long irq_flags;
697         enum xpc_retval ret;
698
699
700         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
701
702         spin_lock_irqsave(&part->act_lock, irq_flags);
703         if (part->act_state == XPC_P_ACTIVATING) {
704                 part->act_state = XPC_P_ACTIVE;
705                 ret = xpcSuccess;
706         } else {
707                 DBUG_ON(part->reason == xpcSuccess);
708                 ret = part->reason;
709         }
710         spin_unlock_irqrestore(&part->act_lock, irq_flags);
711
712         return ret;
713 }
714
715
716 /*
717  * Notify XPC that the partition is down.
718  */
719 void
720 xpc_deactivate_partition(const int line, struct xpc_partition *part,
721                                 enum xpc_retval reason)
722 {
723         unsigned long irq_flags;
724         partid_t partid = XPC_PARTID(part);
725
726
727         spin_lock_irqsave(&part->act_lock, irq_flags);
728
729         if (part->act_state == XPC_P_INACTIVE) {
730                 XPC_SET_REASON(part, reason, line);
731                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
732                 if (reason == xpcReactivating) {
733                         /* we interrupt ourselves to reactivate partition */
734                         xpc_IPI_send_reactivate(part);
735                 }
736                 return;
737         }
738         if (part->act_state == XPC_P_DEACTIVATING) {
739                 if ((part->reason == xpcUnloading && reason != xpcUnloading) ||
740                                         reason == xpcReactivating) {
741                         XPC_SET_REASON(part, reason, line);
742                 }
743                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
744                 return;
745         }
746
747         part->act_state = XPC_P_DEACTIVATING;
748         XPC_SET_REASON(part, reason, line);
749
750         spin_unlock_irqrestore(&part->act_lock, irq_flags);
751
752         XPC_DISALLOW_HB(partid, xpc_vars);
753
754         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n", partid,
755                 reason);
756
757         xpc_partition_down(part, reason);
758 }
759
760
761 /*
762  * Mark specified partition as active.
763  */
764 void
765 xpc_mark_partition_inactive(struct xpc_partition *part)
766 {
767         unsigned long irq_flags;
768
769
770         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
771                 XPC_PARTID(part));
772
773         spin_lock_irqsave(&part->act_lock, irq_flags);
774         part->act_state = XPC_P_INACTIVE;
775         spin_unlock_irqrestore(&part->act_lock, irq_flags);
776         part->remote_rp_pa = 0;
777 }
778
779
780 /*
781  * SAL has provided a partition and machine mask.  The partition mask
782  * contains a bit for each even nasid in our partition.  The machine
783  * mask contains a bit for each even nasid in the entire machine.
784  *
785  * Using those two bit arrays, we can determine which nasids are
786  * known in the machine.  Each should also have a reserved page
787  * initialized if they are available for partitioning.
788  */
789 void
790 xpc_discovery(void)
791 {
792         void *remote_rp_base;
793         struct xpc_rsvd_page *remote_rp;
794         struct xpc_vars *remote_vars;
795         u64 remote_rsvd_page_pa;
796         u64 remote_vars_pa;
797         int region;
798         int max_regions;
799         int nasid;
800         struct xpc_rsvd_page *rp;
801         partid_t partid;
802         struct xpc_partition *part;
803         u64 *discovered_nasids;
804         enum xpc_retval ret;
805
806
807         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RSVD_PAGE_ALIGNED_SIZE,
808                                                 GFP_KERNEL, &remote_rp_base);
809         if (remote_rp == NULL) {
810                 return;
811         }
812         remote_vars = (struct xpc_vars *) remote_rp;
813
814
815         discovered_nasids = kmalloc(sizeof(u64) * XP_NASID_MASK_WORDS,
816                                                         GFP_KERNEL);
817         if (discovered_nasids == NULL) {
818                 kfree(remote_rp_base);
819                 return;
820         }
821         memset(discovered_nasids, 0, sizeof(u64) * XP_NASID_MASK_WORDS);
822
823         rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
824
825         /*
826          * The term 'region' in this context refers to the minimum number of
827          * nodes that can comprise an access protection grouping. The access
828          * protection is in regards to memory, IOI and IPI.
829          */
830 //>>> move the next two #defines into either include/asm-ia64/sn/arch.h or
831 //>>> include/asm-ia64/sn/addrs.h
832 #define SH1_MAX_REGIONS         64
833 #define SH2_MAX_REGIONS         256
834         max_regions = is_shub2() ? SH2_MAX_REGIONS : SH1_MAX_REGIONS;
835
836         for (region = 0; region < max_regions; region++) {
837
838                 if ((volatile int) xpc_exiting) {
839                         break;
840                 }
841
842                 dev_dbg(xpc_part, "searching region %d\n", region);
843
844                 for (nasid = (region * sn_region_size * 2);
845                      nasid < ((region + 1) * sn_region_size * 2);
846                      nasid += 2) {
847
848                         if ((volatile int) xpc_exiting) {
849                                 break;
850                         }
851
852                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
853
854
855                         if (XPC_NASID_IN_ARRAY(nasid, rp->part_nasids)) {
856                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
857                                         "part of the local partition; skipping "
858                                         "region\n", nasid);
859                                 break;
860                         }
861
862                         if (!(XPC_NASID_IN_ARRAY(nasid, rp->mach_nasids))) {
863                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
864                                         "not on Numa-Link network at reset\n",
865                                         nasid);
866                                 continue;
867                         }
868
869                         if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
870                                 dev_dbg(xpc_part, "Nasid %d is part of a "
871                                         "partition which was previously "
872                                         "discovered\n", nasid);
873                                 continue;
874                         }
875
876
877                         /* pull over the reserved page structure */
878
879                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
880                                               remote_rp, &remote_rsvd_page_pa);
881                         if (ret != xpcSuccess) {
882                                 dev_dbg(xpc_part, "unable to get reserved page "
883                                         "from nasid %d, reason=%d\n", nasid,
884                                         ret);
885
886                                 if (ret == xpcLocalPartid) {
887                                         break;
888                                 }
889                                 continue;
890                         }
891
892                         remote_vars_pa = remote_rp->vars_pa;
893
894                         partid = remote_rp->partid;
895                         part = &xpc_partitions[partid];
896
897
898                         /* pull over the cross partition variables */
899
900                         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
901                         if (ret != xpcSuccess) {
902                                 dev_dbg(xpc_part, "unable to get XPC variables "
903                                         "from nasid %d, reason=%d\n", nasid,
904                                         ret);
905
906                                 XPC_DEACTIVATE_PARTITION(part, ret);
907                                 continue;
908                         }
909
910                         if (part->act_state != XPC_P_INACTIVE) {
911                                 dev_dbg(xpc_part, "partition %d on nasid %d is "
912                                         "already activating\n", partid, nasid);
913                                 break;
914                         }
915
916                         /*
917                          * Register the remote partition's AMOs with SAL so it
918                          * can handle and cleanup errors within that address
919                          * range should the remote partition go down. We don't
920                          * unregister this range because it is difficult to
921                          * tell when outstanding writes to the remote partition
922                          * are finished and thus when it is thus safe to
923                          * unregister. This should not result in wasted space
924                          * in the SAL xp_addr_region table because we should
925                          * get the same page for remote_act_amos_pa after
926                          * module reloads and system reboots.
927                          */
928                         if (sn_register_xp_addr_region(
929                                             remote_vars->amos_page_pa,
930                                                         PAGE_SIZE, 1) < 0) {
931                                 dev_dbg(xpc_part, "partition %d failed to "
932                                         "register xp_addr region 0x%016lx\n",
933                                         partid, remote_vars->amos_page_pa);
934
935                                 XPC_SET_REASON(part, xpcPhysAddrRegFailed,
936                                                 __LINE__);
937                                 break;
938                         }
939
940                         /*
941                          * The remote nasid is valid and available.
942                          * Send an interrupt to that nasid to notify
943                          * it that we are ready to begin activation.
944                          */
945                         dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
946                                 "nasid %d, phys_cpuid 0x%x\n",
947                                 remote_vars->amos_page_pa,
948                                 remote_vars->act_nasid,
949                                 remote_vars->act_phys_cpuid);
950
951                         xpc_IPI_send_activate(remote_vars);
952                 }
953         }
954
955         kfree(discovered_nasids);
956         kfree(remote_rp_base);
957 }
958
959
960 /*
961  * Given a partid, get the nasids owned by that partition from the
962  * remote partition's reserved page.
963  */
964 enum xpc_retval
965 xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
966 {
967         struct xpc_partition *part;
968         u64 part_nasid_pa;
969         int bte_res;
970
971
972         part = &xpc_partitions[partid];
973         if (part->remote_rp_pa == 0) {
974                 return xpcPartitionDown;
975         }
976
977         part_nasid_pa = part->remote_rp_pa +
978                 (u64) &((struct xpc_rsvd_page *) 0)->part_nasids;
979
980         bte_res = xp_bte_copy(part_nasid_pa, ia64_tpa((u64) nasid_mask),
981                                 L1_CACHE_ALIGN(XP_NASID_MASK_BYTES),
982                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
983
984         return xpc_map_bte_errors(bte_res);
985 }
986