[IA64-SGI] XPC changes to support more than 2k nasids
[linux-2.6] / 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_COMPACT_NODES];
48
49
50 /* this partition's reserved page pointers */
51 struct xpc_rsvd_page *xpc_rsvd_page;
52 static u64 *xpc_part_nasids;
53 static u64 *xpc_mach_nasids;
54 struct xpc_vars *xpc_vars;
55 struct xpc_vars_part *xpc_vars_part;
56
57 static int xp_nasid_mask_bytes; /* actual size in bytes of nasid mask */
58 static int xp_nasid_mask_words; /* actual size in words of nasid mask */
59
60
61 /*
62  * For performance reasons, each entry of xpc_partitions[] is cacheline
63  * aligned. And xpc_partitions[] is padded with an additional entry at the
64  * end so that the last legitimate entry doesn't share its cacheline with
65  * another variable.
66  */
67 struct xpc_partition xpc_partitions[XP_MAX_PARTITIONS + 1];
68
69
70 /*
71  * Generic buffer used to store a local copy of portions of a remote
72  * partition's reserved page (either its header and part_nasids mask,
73  * or its vars).
74  *
75  * xpc_discovery runs only once and is a seperate thread that is
76  * very likely going to be processing in parallel with receiving
77  * interrupts.
78  */
79 char ____cacheline_aligned xpc_remote_copy_buffer[XPC_RP_HEADER_SIZE +
80                                                         XP_NASID_MASK_BYTES];
81
82
83 /*
84  * Given a nasid, get the physical address of the  partition's reserved page
85  * for that nasid. This function returns 0 on any error.
86  */
87 static u64
88 xpc_get_rsvd_page_pa(int nasid, u64 buf, u64 buf_size)
89 {
90         bte_result_t bte_res;
91         s64 status;
92         u64 cookie = 0;
93         u64 rp_pa = nasid;      /* seed with nasid */
94         u64 len = 0;
95
96
97         while (1) {
98
99                 status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
100                                                                 &len);
101
102                 dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
103                         "0x%016lx, address=0x%016lx, len=0x%016lx\n",
104                         status, cookie, rp_pa, len);
105
106                 if (status != SALRET_MORE_PASSES) {
107                         break;
108                 }
109
110                 if (len > buf_size) {
111                         dev_err(xpc_part, "len (=0x%016lx) > buf_size\n", len);
112                         status = SALRET_ERROR;
113                         break;
114                 }
115
116                 bte_res = xp_bte_copy(rp_pa, ia64_tpa(buf), buf_size,
117                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
118                 if (bte_res != BTE_SUCCESS) {
119                         dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
120                         status = SALRET_ERROR;
121                         break;
122                 }
123         }
124
125         if (status != SALRET_OK) {
126                 rp_pa = 0;
127         }
128         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
129         return rp_pa;
130 }
131
132
133 /*
134  * Fill the partition reserved page with the information needed by
135  * other partitions to discover we are alive and establish initial
136  * communications.
137  */
138 struct xpc_rsvd_page *
139 xpc_rsvd_page_init(void)
140 {
141         struct xpc_rsvd_page *rp;
142         AMO_t *amos_page;
143         u64 rp_pa, nasid_array = 0;
144         int i, ret;
145
146
147         /* get the local reserved page's address */
148
149         rp_pa = xpc_get_rsvd_page_pa(cnodeid_to_nasid(0),
150                                         (u64) xpc_remote_copy_buffer,
151                                                 XPC_RP_HEADER_SIZE +
152                                                         L1_CACHE_BYTES);
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         /* establish the actual sizes of the nasid masks */
168         if (rp->SAL_version == 1) {
169                 /* SAL_version 1 didn't set the nasids_size field */
170                 rp->nasids_size = 128;
171         }
172         xp_nasid_mask_bytes = rp->nasids_size;
173         xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
174
175         /* setup the pointers to the various items in the reserved page */
176         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
177         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
178         xpc_vars = XPC_RP_VARS(rp);
179         xpc_vars_part = XPC_RP_VARS_PART(rp);
180
181         /*
182          * Before clearing xpc_vars, see if a page of AMOs had been previously
183          * allocated. If not we'll need to allocate one and set permissions
184          * so that cross-partition AMOs are allowed.
185          *
186          * The allocated AMO page needs MCA reporting to remain disabled after
187          * XPC has unloaded.  To make this work, we keep a copy of the pointer
188          * to this page (i.e., amos_page) in the struct xpc_vars structure,
189          * which is pointed to by the reserved page, and re-use that saved copy
190          * on subsequent loads of XPC. This AMO page is never freed, and its
191          * memory protections are never restricted.
192          */
193         if ((amos_page = xpc_vars->amos_page) == NULL) {
194                 amos_page = (AMO_t *) TO_AMO(uncached_alloc_page(0));
195                 if (amos_page == NULL) {
196                         dev_err(xpc_part, "can't allocate page of AMOs\n");
197                         return NULL;
198                 }
199
200                 /*
201                  * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
202                  * when xpc_allow_IPI_ops() is called via xpc_hb_init().
203                  */
204                 if (!enable_shub_wars_1_1()) {
205                         ret = sn_change_memprotect(ia64_tpa((u64) amos_page),
206                                         PAGE_SIZE, SN_MEMPROT_ACCESS_CLASS_1,
207                                         &nasid_array);
208                         if (ret != 0) {
209                                 dev_err(xpc_part, "can't change memory "
210                                         "protections\n");
211                                 uncached_free_page(__IA64_UNCACHED_OFFSET |
212                                                    TO_PHYS((u64) amos_page));
213                                 return NULL;
214                         }
215                 }
216         } else if (!IS_AMO_ADDRESS((u64) amos_page)) {
217                 /*
218                  * EFI's XPBOOT can also set amos_page in the reserved page,
219                  * but it happens to leave it as an uncached physical address
220                  * and we need it to be an uncached virtual, so we'll have to
221                  * convert it.
222                  */
223                 if (!IS_AMO_PHYS_ADDRESS((u64) amos_page)) {
224                         dev_err(xpc_part, "previously used amos_page address "
225                                 "is bad = 0x%p\n", (void *) amos_page);
226                         return NULL;
227                 }
228                 amos_page = (AMO_t *) TO_AMO((u64) amos_page);
229         }
230
231         /* clear xpc_vars */
232         memset(xpc_vars, 0, sizeof(struct xpc_vars));
233
234         xpc_vars->version = XPC_V_VERSION;
235         xpc_vars->act_nasid = cpuid_to_nasid(0);
236         xpc_vars->act_phys_cpuid = cpu_physical_id(0);
237         xpc_vars->vars_part_pa = __pa(xpc_vars_part);
238         xpc_vars->amos_page_pa = ia64_tpa((u64) amos_page);
239         xpc_vars->amos_page = amos_page;  /* save for next load of XPC */
240
241
242         /* clear xpc_vars_part */
243         memset((u64 *) xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
244                                                         XP_MAX_PARTITIONS);
245
246         /* initialize the activate IRQ related AMO variables */
247         for (i = 0; i < xp_nasid_mask_words; i++) {
248                 (void) xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
249         }
250
251         /* initialize the engaged remote partitions related AMO variables */
252         (void) xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
253         (void) xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
254
255         /* timestamp of when reserved page was setup by XPC */
256         rp->stamp = CURRENT_TIME;
257
258         /*
259          * This signifies to the remote partition that our reserved
260          * page is initialized.
261          */
262         rp->vars_pa = __pa(xpc_vars);
263
264         return rp;
265 }
266
267
268 /*
269  * Change protections to allow IPI operations (and AMO operations on
270  * Shub 1.1 systems).
271  */
272 void
273 xpc_allow_IPI_ops(void)
274 {
275         int node;
276         int nasid;
277
278
279         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
280
281         if (is_shub2()) {
282                 xpc_sh2_IPI_access0 =
283                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
284                 xpc_sh2_IPI_access1 =
285                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
286                 xpc_sh2_IPI_access2 =
287                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
288                 xpc_sh2_IPI_access3 =
289                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
290
291                 for_each_online_node(node) {
292                         nasid = cnodeid_to_nasid(node);
293                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
294                                                                 -1UL);
295                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
296                                                                 -1UL);
297                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
298                                                                 -1UL);
299                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
300                                                                 -1UL);
301                 }
302
303         } else {
304                 xpc_sh1_IPI_access =
305                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
306
307                 for_each_online_node(node) {
308                         nasid = cnodeid_to_nasid(node);
309                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
310                                                                 -1UL);
311
312                         /*
313                          * Since the BIST collides with memory operations on
314                          * SHUB 1.1 sn_change_memprotect() cannot be used.
315                          */
316                         if (enable_shub_wars_1_1()) {
317                                 /* open up everything */
318                                 xpc_prot_vec[node] = (u64) HUB_L((u64 *)
319                                                 GLOBAL_MMR_ADDR(nasid,
320                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0));
321                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
322                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
323                                                                 -1UL);
324                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
325                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
326                                                                 -1UL);
327                         }
328                 }
329         }
330 }
331
332
333 /*
334  * Restrict protections to disallow IPI operations (and AMO operations on
335  * Shub 1.1 systems).
336  */
337 void
338 xpc_restrict_IPI_ops(void)
339 {
340         int node;
341         int nasid;
342
343
344         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
345
346         if (is_shub2()) {
347
348                 for_each_online_node(node) {
349                         nasid = cnodeid_to_nasid(node);
350                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
351                                                         xpc_sh2_IPI_access0);
352                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
353                                                         xpc_sh2_IPI_access1);
354                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
355                                                         xpc_sh2_IPI_access2);
356                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
357                                                         xpc_sh2_IPI_access3);
358                 }
359
360         } else {
361
362                 for_each_online_node(node) {
363                         nasid = cnodeid_to_nasid(node);
364                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
365                                                         xpc_sh1_IPI_access);
366
367                         if (enable_shub_wars_1_1()) {
368                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
369                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
370                                                         xpc_prot_vec[node]);
371                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
372                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
373                                                         xpc_prot_vec[node]);
374                         }
375                 }
376         }
377 }
378
379
380 /*
381  * At periodic intervals, scan through all active partitions and ensure
382  * their heartbeat is still active.  If not, the partition is deactivated.
383  */
384 void
385 xpc_check_remote_hb(void)
386 {
387         struct xpc_vars *remote_vars;
388         struct xpc_partition *part;
389         partid_t partid;
390         bte_result_t bres;
391
392
393         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
394
395         for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
396
397                 if (xpc_exiting) {
398                         break;
399                 }
400
401                 if (partid == sn_partition_id) {
402                         continue;
403                 }
404
405                 part = &xpc_partitions[partid];
406
407                 if (part->act_state == XPC_P_INACTIVE ||
408                                 part->act_state == XPC_P_DEACTIVATING) {
409                         continue;
410                 }
411
412                 /* pull the remote_hb cache line */
413                 bres = xp_bte_copy(part->remote_vars_pa,
414                                         ia64_tpa((u64) remote_vars),
415                                         XPC_RP_VARS_SIZE,
416                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
417                 if (bres != BTE_SUCCESS) {
418                         XPC_DEACTIVATE_PARTITION(part,
419                                                 xpc_map_bte_errors(bres));
420                         continue;
421                 }
422
423                 dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
424                         " = %ld, kdb_status = %ld, HB_mask = 0x%lx\n", partid,
425                         remote_vars->heartbeat, part->last_heartbeat,
426                         remote_vars->kdb_status,
427                         remote_vars->heartbeating_to_mask);
428
429                 if (((remote_vars->heartbeat == part->last_heartbeat) &&
430                         (remote_vars->kdb_status == 0)) ||
431                              !xpc_hb_allowed(sn_partition_id, remote_vars)) {
432
433                         XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
434                         continue;
435                 }
436
437                 part->last_heartbeat = remote_vars->heartbeat;
438         }
439 }
440
441
442 /*
443  * Get a copy of a portion of the remote partition's rsvd page.
444  *
445  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
446  * is large enough to contain a copy of their reserved page header and
447  * part_nasids mask.
448  */
449 static enum xpc_retval
450 xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
451                 struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
452 {
453         int bres, i;
454
455
456         /* get the reserved page's physical address */
457
458         *remote_rp_pa = xpc_get_rsvd_page_pa(nasid, (u64) remote_rp,
459                                                 XPC_RP_HEADER_SIZE +
460                                                         xp_nasid_mask_bytes);
461         if (*remote_rp_pa == 0) {
462                 return xpcNoRsvdPageAddr;
463         }
464
465
466         /* pull over the reserved page header and part_nasids mask */
467
468         bres = xp_bte_copy(*remote_rp_pa, ia64_tpa((u64) remote_rp),
469                                 XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes,
470                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
471         if (bres != BTE_SUCCESS) {
472                 return xpc_map_bte_errors(bres);
473         }
474
475
476         if (discovered_nasids != NULL) {
477                 u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
478
479
480                 for (i = 0; i < xp_nasid_mask_words; i++) {
481                         discovered_nasids[i] |= remote_part_nasids[i];
482                 }
483         }
484
485
486         /* check that the partid is for another partition */
487
488         if (remote_rp->partid < 1 ||
489                                 remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
490                 return xpcInvalidPartid;
491         }
492
493         if (remote_rp->partid == sn_partition_id) {
494                 return xpcLocalPartid;
495         }
496
497
498         if (XPC_VERSION_MAJOR(remote_rp->version) !=
499                                         XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
500                 return xpcBadVersion;
501         }
502
503         return xpcSuccess;
504 }
505
506
507 /*
508  * Get a copy of the remote partition's XPC variables from the reserved page.
509  *
510  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
511  * assumed to be of size XPC_RP_VARS_SIZE.
512  */
513 static enum xpc_retval
514 xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
515 {
516         int bres;
517
518
519         if (remote_vars_pa == 0) {
520                 return xpcVarsNotSet;
521         }
522
523
524         /* pull over the cross partition variables */
525
526         bres = xp_bte_copy(remote_vars_pa, ia64_tpa((u64) remote_vars),
527                                 XPC_RP_VARS_SIZE,
528                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
529         if (bres != BTE_SUCCESS) {
530                 return xpc_map_bte_errors(bres);
531         }
532
533         if (XPC_VERSION_MAJOR(remote_vars->version) !=
534                                         XPC_VERSION_MAJOR(XPC_V_VERSION)) {
535                 return xpcBadVersion;
536         }
537
538         return xpcSuccess;
539 }
540
541
542 /*
543  * Update the remote partition's info.
544  */
545 static void
546 xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
547                 struct timespec *remote_rp_stamp, u64 remote_rp_pa,
548                 u64 remote_vars_pa, struct xpc_vars *remote_vars)
549 {
550         part->remote_rp_version = remote_rp_version;
551         dev_dbg(xpc_part, "  remote_rp_version = 0x%016lx\n",
552                 part->remote_rp_version);
553
554         part->remote_rp_stamp = *remote_rp_stamp;
555         dev_dbg(xpc_part, "  remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
556                 part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
557
558         part->remote_rp_pa = remote_rp_pa;
559         dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
560
561         part->remote_vars_pa = remote_vars_pa;
562         dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
563                 part->remote_vars_pa);
564
565         part->last_heartbeat = remote_vars->heartbeat;
566         dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
567                 part->last_heartbeat);
568
569         part->remote_vars_part_pa = remote_vars->vars_part_pa;
570         dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
571                 part->remote_vars_part_pa);
572
573         part->remote_act_nasid = remote_vars->act_nasid;
574         dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
575                 part->remote_act_nasid);
576
577         part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
578         dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
579                 part->remote_act_phys_cpuid);
580
581         part->remote_amos_page_pa = remote_vars->amos_page_pa;
582         dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
583                 part->remote_amos_page_pa);
584
585         part->remote_vars_version = remote_vars->version;
586         dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
587                 part->remote_vars_version);
588 }
589
590
591 /*
592  * Prior code has determined the nasid which generated an IPI.  Inspect
593  * that nasid to determine if its partition needs to be activated or
594  * deactivated.
595  *
596  * A partition is consider "awaiting activation" if our partition
597  * flags indicate it is not active and it has a heartbeat.  A
598  * partition is considered "awaiting deactivation" if our partition
599  * flags indicate it is active but it has no heartbeat or it is not
600  * sending its heartbeat to us.
601  *
602  * To determine the heartbeat, the remote nasid must have a properly
603  * initialized reserved page.
604  */
605 static void
606 xpc_identify_act_IRQ_req(int nasid)
607 {
608         struct xpc_rsvd_page *remote_rp;
609         struct xpc_vars *remote_vars;
610         u64 remote_rp_pa;
611         u64 remote_vars_pa;
612         int remote_rp_version;
613         int reactivate = 0;
614         int stamp_diff;
615         struct timespec remote_rp_stamp = { 0, 0 };
616         partid_t partid;
617         struct xpc_partition *part;
618         enum xpc_retval ret;
619
620
621         /* pull over the reserved page structure */
622
623         remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;
624
625         ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
626         if (ret != xpcSuccess) {
627                 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
628                         "which sent interrupt, reason=%d\n", nasid, ret);
629                 return;
630         }
631
632         remote_vars_pa = remote_rp->vars_pa;
633         remote_rp_version = remote_rp->version;
634         if (XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
635                 remote_rp_stamp = remote_rp->stamp;
636         }
637         partid = remote_rp->partid;
638         part = &xpc_partitions[partid];
639
640
641         /* pull over the cross partition variables */
642
643         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
644
645         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
646         if (ret != xpcSuccess) {
647
648                 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
649                         "which sent interrupt, reason=%d\n", nasid, ret);
650
651                 XPC_DEACTIVATE_PARTITION(part, ret);
652                 return;
653         }
654
655
656         part->act_IRQ_rcvd++;
657
658         dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
659                 "%ld:0x%lx\n", (int) nasid, (int) partid, part->act_IRQ_rcvd,
660                 remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
661
662         if (xpc_partition_disengaged(part) &&
663                                         part->act_state == XPC_P_INACTIVE) {
664
665                 xpc_update_partition_info(part, remote_rp_version,
666                                         &remote_rp_stamp, remote_rp_pa,
667                                         remote_vars_pa, remote_vars);
668
669                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
670                         if (xpc_partition_disengage_requested(1UL << partid)) {
671                                 /*
672                                  * Other side is waiting on us to disengage,
673                                  * even though we already have.
674                                  */
675                                 return;
676                         }
677                 } else {
678                         /* other side doesn't support disengage requests */
679                         xpc_clear_partition_disengage_request(1UL << partid);
680                 }
681
682                 xpc_activate_partition(part);
683                 return;
684         }
685
686         DBUG_ON(part->remote_rp_version == 0);
687         DBUG_ON(part->remote_vars_version == 0);
688
689         if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
690                 DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
691                                                         remote_vars_version));
692
693                 if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
694                         DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
695                                                                 version));
696                         /* see if the other side rebooted */
697                         if (part->remote_amos_page_pa ==
698                                 remote_vars->amos_page_pa &&
699                                         xpc_hb_allowed(sn_partition_id,
700                                                                 remote_vars)) {
701                                 /* doesn't look that way, so ignore the IPI */
702                                 return;
703                         }
704                 }
705
706                 /*
707                  * Other side rebooted and previous XPC didn't support the
708                  * disengage request, so we don't need to do anything special.
709                  */
710
711                 xpc_update_partition_info(part, remote_rp_version,
712                                                 &remote_rp_stamp, remote_rp_pa,
713                                                 remote_vars_pa, remote_vars);
714                 part->reactivate_nasid = nasid;
715                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
716                 return;
717         }
718
719         DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
720
721         if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
722                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
723
724                 /*
725                  * Other side rebooted and previous XPC did support the
726                  * disengage request, but the new one doesn't.
727                  */
728
729                 xpc_clear_partition_engaged(1UL << partid);
730                 xpc_clear_partition_disengage_request(1UL << partid);
731
732                 xpc_update_partition_info(part, remote_rp_version,
733                                                 &remote_rp_stamp, remote_rp_pa,
734                                                 remote_vars_pa, remote_vars);
735                 reactivate = 1;
736
737         } else {
738                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
739
740                 stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
741                                                         &remote_rp_stamp);
742                 if (stamp_diff != 0) {
743                         DBUG_ON(stamp_diff >= 0);
744
745                         /*
746                          * Other side rebooted and the previous XPC did support
747                          * the disengage request, as does the new one.
748                          */
749
750                         DBUG_ON(xpc_partition_engaged(1UL << partid));
751                         DBUG_ON(xpc_partition_disengage_requested(1UL <<
752                                                                 partid));
753
754                         xpc_update_partition_info(part, remote_rp_version,
755                                                 &remote_rp_stamp, remote_rp_pa,
756                                                 remote_vars_pa, remote_vars);
757                         reactivate = 1;
758                 }
759         }
760
761         if (!xpc_partition_disengaged(part)) {
762                 /* still waiting on other side to disengage from us */
763                 return;
764         }
765
766         if (reactivate) {
767                 part->reactivate_nasid = nasid;
768                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
769
770         } else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
771                         xpc_partition_disengage_requested(1UL << partid)) {
772                 XPC_DEACTIVATE_PARTITION(part, xpcOtherGoingDown);
773         }
774 }
775
776
777 /*
778  * Loop through the activation AMO variables and process any bits
779  * which are set.  Each bit indicates a nasid sending a partition
780  * activation or deactivation request.
781  *
782  * Return #of IRQs detected.
783  */
784 int
785 xpc_identify_act_IRQ_sender(void)
786 {
787         int word, bit;
788         u64 nasid_mask;
789         u64 nasid;                      /* remote nasid */
790         int n_IRQs_detected = 0;
791         AMO_t *act_amos;
792
793
794         act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
795
796
797         /* scan through act AMO variable looking for non-zero entries */
798         for (word = 0; word < xp_nasid_mask_words; word++) {
799
800                 if (xpc_exiting) {
801                         break;
802                 }
803
804                 nasid_mask = xpc_IPI_receive(&act_amos[word]);
805                 if (nasid_mask == 0) {
806                         /* no IRQs from nasids in this variable */
807                         continue;
808                 }
809
810                 dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
811                         nasid_mask);
812
813
814                 /*
815                  * If this nasid has been added to the machine since
816                  * our partition was reset, this will retain the
817                  * remote nasid in our reserved pages machine mask.
818                  * This is used in the event of module reload.
819                  */
820                 xpc_mach_nasids[word] |= nasid_mask;
821
822
823                 /* locate the nasid(s) which sent interrupts */
824
825                 for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
826                         if (nasid_mask & (1UL << bit)) {
827                                 n_IRQs_detected++;
828                                 nasid = XPC_NASID_FROM_W_B(word, bit);
829                                 dev_dbg(xpc_part, "interrupt from nasid %ld\n",
830                                         nasid);
831                                 xpc_identify_act_IRQ_req(nasid);
832                         }
833                 }
834         }
835         return n_IRQs_detected;
836 }
837
838
839 /*
840  * See if the other side has responded to a partition disengage request
841  * from us.
842  */
843 int
844 xpc_partition_disengaged(struct xpc_partition *part)
845 {
846         partid_t partid = XPC_PARTID(part);
847         int disengaged;
848
849
850         disengaged = (xpc_partition_engaged(1UL << partid) == 0);
851         if (part->disengage_request_timeout) {
852                 if (!disengaged) {
853                         if (jiffies < part->disengage_request_timeout) {
854                                 /* timelimit hasn't been reached yet */
855                                 return 0;
856                         }
857
858                         /*
859                          * Other side hasn't responded to our disengage
860                          * request in a timely fashion, so assume it's dead.
861                          */
862
863                         xpc_clear_partition_engaged(1UL << partid);
864                         disengaged = 1;
865                 }
866                 part->disengage_request_timeout = 0;
867
868                 /* cancel the timer function, provided it's not us */
869                 if (!in_interrupt()) {
870                         del_singleshot_timer_sync(&part->
871                                                       disengage_request_timer);
872                 }
873
874                 DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
875                                         part->act_state != XPC_P_INACTIVE);
876                 if (part->act_state != XPC_P_INACTIVE) {
877                         xpc_wakeup_channel_mgr(part);
878                 }
879
880                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
881                         xpc_cancel_partition_disengage_request(part);
882                 }
883         }
884         return disengaged;
885 }
886
887
888 /*
889  * Mark specified partition as active.
890  */
891 enum xpc_retval
892 xpc_mark_partition_active(struct xpc_partition *part)
893 {
894         unsigned long irq_flags;
895         enum xpc_retval ret;
896
897
898         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
899
900         spin_lock_irqsave(&part->act_lock, irq_flags);
901         if (part->act_state == XPC_P_ACTIVATING) {
902                 part->act_state = XPC_P_ACTIVE;
903                 ret = xpcSuccess;
904         } else {
905                 DBUG_ON(part->reason == xpcSuccess);
906                 ret = part->reason;
907         }
908         spin_unlock_irqrestore(&part->act_lock, irq_flags);
909
910         return ret;
911 }
912
913
914 /*
915  * Notify XPC that the partition is down.
916  */
917 void
918 xpc_deactivate_partition(const int line, struct xpc_partition *part,
919                                 enum xpc_retval reason)
920 {
921         unsigned long irq_flags;
922
923
924         spin_lock_irqsave(&part->act_lock, irq_flags);
925
926         if (part->act_state == XPC_P_INACTIVE) {
927                 XPC_SET_REASON(part, reason, line);
928                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
929                 if (reason == xpcReactivating) {
930                         /* we interrupt ourselves to reactivate partition */
931                         xpc_IPI_send_reactivate(part);
932                 }
933                 return;
934         }
935         if (part->act_state == XPC_P_DEACTIVATING) {
936                 if ((part->reason == xpcUnloading && reason != xpcUnloading) ||
937                                         reason == xpcReactivating) {
938                         XPC_SET_REASON(part, reason, line);
939                 }
940                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
941                 return;
942         }
943
944         part->act_state = XPC_P_DEACTIVATING;
945         XPC_SET_REASON(part, reason, line);
946
947         spin_unlock_irqrestore(&part->act_lock, irq_flags);
948
949         if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
950                 xpc_request_partition_disengage(part);
951                 xpc_IPI_send_disengage(part);
952
953                 /* set a timelimit on the disengage request */
954                 part->disengage_request_timeout = jiffies +
955                                         (xpc_disengage_request_timelimit * HZ);
956                 part->disengage_request_timer.expires =
957                                         part->disengage_request_timeout;
958                 add_timer(&part->disengage_request_timer);
959         }
960
961         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
962                 XPC_PARTID(part), reason);
963
964         xpc_partition_going_down(part, reason);
965 }
966
967
968 /*
969  * Mark specified partition as inactive.
970  */
971 void
972 xpc_mark_partition_inactive(struct xpc_partition *part)
973 {
974         unsigned long irq_flags;
975
976
977         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
978                 XPC_PARTID(part));
979
980         spin_lock_irqsave(&part->act_lock, irq_flags);
981         part->act_state = XPC_P_INACTIVE;
982         spin_unlock_irqrestore(&part->act_lock, irq_flags);
983         part->remote_rp_pa = 0;
984 }
985
986
987 /*
988  * SAL has provided a partition and machine mask.  The partition mask
989  * contains a bit for each even nasid in our partition.  The machine
990  * mask contains a bit for each even nasid in the entire machine.
991  *
992  * Using those two bit arrays, we can determine which nasids are
993  * known in the machine.  Each should also have a reserved page
994  * initialized if they are available for partitioning.
995  */
996 void
997 xpc_discovery(void)
998 {
999         void *remote_rp_base;
1000         struct xpc_rsvd_page *remote_rp;
1001         struct xpc_vars *remote_vars;
1002         u64 remote_rp_pa;
1003         u64 remote_vars_pa;
1004         int region;
1005         int region_size;
1006         int max_regions;
1007         int nasid;
1008         struct xpc_rsvd_page *rp;
1009         partid_t partid;
1010         struct xpc_partition *part;
1011         u64 *discovered_nasids;
1012         enum xpc_retval ret;
1013
1014
1015         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
1016                                                 xp_nasid_mask_bytes,
1017                                                 GFP_KERNEL, &remote_rp_base);
1018         if (remote_rp == NULL) {
1019                 return;
1020         }
1021         remote_vars = (struct xpc_vars *) remote_rp;
1022
1023
1024         discovered_nasids = kmalloc(sizeof(u64) * xp_nasid_mask_words,
1025                                                         GFP_KERNEL);
1026         if (discovered_nasids == NULL) {
1027                 kfree(remote_rp_base);
1028                 return;
1029         }
1030         memset(discovered_nasids, 0, sizeof(u64) * xp_nasid_mask_words);
1031
1032         rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
1033
1034         /*
1035          * The term 'region' in this context refers to the minimum number of
1036          * nodes that can comprise an access protection grouping. The access
1037          * protection is in regards to memory, IOI and IPI.
1038          */
1039         max_regions = 64;
1040         region_size = sn_region_size;
1041
1042         switch (region_size) {
1043         case 128:
1044                 max_regions *= 2;
1045         case 64:
1046                 max_regions *= 2;
1047         case 32:
1048                 max_regions *= 2;
1049                 region_size = 16;
1050                 DBUG_ON(!is_shub2());
1051         }
1052
1053         for (region = 0; region < max_regions; region++) {
1054
1055                 if ((volatile int) xpc_exiting) {
1056                         break;
1057                 }
1058
1059                 dev_dbg(xpc_part, "searching region %d\n", region);
1060
1061                 for (nasid = (region * region_size * 2);
1062                      nasid < ((region + 1) * region_size * 2);
1063                      nasid += 2) {
1064
1065                         if ((volatile int) xpc_exiting) {
1066                                 break;
1067                         }
1068
1069                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
1070
1071
1072                         if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
1073                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
1074                                         "part of the local partition; skipping "
1075                                         "region\n", nasid);
1076                                 break;
1077                         }
1078
1079                         if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
1080                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
1081                                         "not on Numa-Link network at reset\n",
1082                                         nasid);
1083                                 continue;
1084                         }
1085
1086                         if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
1087                                 dev_dbg(xpc_part, "Nasid %d is part of a "
1088                                         "partition which was previously "
1089                                         "discovered\n", nasid);
1090                                 continue;
1091                         }
1092
1093
1094                         /* pull over the reserved page structure */
1095
1096                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
1097                                               remote_rp, &remote_rp_pa);
1098                         if (ret != xpcSuccess) {
1099                                 dev_dbg(xpc_part, "unable to get reserved page "
1100                                         "from nasid %d, reason=%d\n", nasid,
1101                                         ret);
1102
1103                                 if (ret == xpcLocalPartid) {
1104                                         break;
1105                                 }
1106                                 continue;
1107                         }
1108
1109                         remote_vars_pa = remote_rp->vars_pa;
1110
1111                         partid = remote_rp->partid;
1112                         part = &xpc_partitions[partid];
1113
1114
1115                         /* pull over the cross partition variables */
1116
1117                         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
1118                         if (ret != xpcSuccess) {
1119                                 dev_dbg(xpc_part, "unable to get XPC variables "
1120                                         "from nasid %d, reason=%d\n", nasid,
1121                                         ret);
1122
1123                                 XPC_DEACTIVATE_PARTITION(part, ret);
1124                                 continue;
1125                         }
1126
1127                         if (part->act_state != XPC_P_INACTIVE) {
1128                                 dev_dbg(xpc_part, "partition %d on nasid %d is "
1129                                         "already activating\n", partid, nasid);
1130                                 break;
1131                         }
1132
1133                         /*
1134                          * Register the remote partition's AMOs with SAL so it
1135                          * can handle and cleanup errors within that address
1136                          * range should the remote partition go down. We don't
1137                          * unregister this range because it is difficult to
1138                          * tell when outstanding writes to the remote partition
1139                          * are finished and thus when it is thus safe to
1140                          * unregister. This should not result in wasted space
1141                          * in the SAL xp_addr_region table because we should
1142                          * get the same page for remote_act_amos_pa after
1143                          * module reloads and system reboots.
1144                          */
1145                         if (sn_register_xp_addr_region(
1146                                             remote_vars->amos_page_pa,
1147                                                         PAGE_SIZE, 1) < 0) {
1148                                 dev_dbg(xpc_part, "partition %d failed to "
1149                                         "register xp_addr region 0x%016lx\n",
1150                                         partid, remote_vars->amos_page_pa);
1151
1152                                 XPC_SET_REASON(part, xpcPhysAddrRegFailed,
1153                                                 __LINE__);
1154                                 break;
1155                         }
1156
1157                         /*
1158                          * The remote nasid is valid and available.
1159                          * Send an interrupt to that nasid to notify
1160                          * it that we are ready to begin activation.
1161                          */
1162                         dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
1163                                 "nasid %d, phys_cpuid 0x%x\n",
1164                                 remote_vars->amos_page_pa,
1165                                 remote_vars->act_nasid,
1166                                 remote_vars->act_phys_cpuid);
1167
1168                         if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
1169                                                                 version)) {
1170                                 part->remote_amos_page_pa =
1171                                                 remote_vars->amos_page_pa;
1172                                 xpc_mark_partition_disengaged(part);
1173                                 xpc_cancel_partition_disengage_request(part);
1174                         }
1175                         xpc_IPI_send_activate(remote_vars);
1176                 }
1177         }
1178
1179         kfree(discovered_nasids);
1180         kfree(remote_rp_base);
1181 }
1182
1183
1184 /*
1185  * Given a partid, get the nasids owned by that partition from the
1186  * remote partition's reserved page.
1187  */
1188 enum xpc_retval
1189 xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
1190 {
1191         struct xpc_partition *part;
1192         u64 part_nasid_pa;
1193         int bte_res;
1194
1195
1196         part = &xpc_partitions[partid];
1197         if (part->remote_rp_pa == 0) {
1198                 return xpcPartitionDown;
1199         }
1200
1201         memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
1202
1203         part_nasid_pa = (u64) XPC_RP_PART_NASIDS(part->remote_rp_pa);
1204
1205         bte_res = xp_bte_copy(part_nasid_pa, ia64_tpa((u64) nasid_mask),
1206                         xp_nasid_mask_bytes, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
1207
1208         return xpc_map_bte_errors(bte_res);
1209 }
1210