[IA64] minor irq handler cleanups
[linux-2.6.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) 2004-2006 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 <asm/sn/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 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 char *xpc_remote_copy_buffer;
76 void *xpc_remote_copy_buffer_base;
77
78
79 /*
80  * Guarantee that the kmalloc'd memory is cacheline aligned.
81  */
82 void *
83 xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
84 {
85         /* see if kmalloc will give us cachline aligned memory by default */
86         *base = kmalloc(size, flags);
87         if (*base == NULL) {
88                 return NULL;
89         }
90         if ((u64) *base == L1_CACHE_ALIGN((u64) *base)) {
91                 return *base;
92         }
93         kfree(*base);
94
95         /* nope, we'll have to do it ourselves */
96         *base = kmalloc(size + L1_CACHE_BYTES, flags);
97         if (*base == NULL) {
98                 return NULL;
99         }
100         return (void *) L1_CACHE_ALIGN((u64) *base);
101 }
102
103
104 /*
105  * Given a nasid, get the physical address of the  partition's reserved page
106  * for that nasid. This function returns 0 on any error.
107  */
108 static u64
109 xpc_get_rsvd_page_pa(int nasid)
110 {
111         bte_result_t bte_res;
112         s64 status;
113         u64 cookie = 0;
114         u64 rp_pa = nasid;      /* seed with nasid */
115         u64 len = 0;
116         u64 buf = buf;
117         u64 buf_len = 0;
118         void *buf_base = NULL;
119
120
121         while (1) {
122
123                 status = sn_partition_reserved_page_pa(buf, &cookie, &rp_pa,
124                                                                 &len);
125
126                 dev_dbg(xpc_part, "SAL returned with status=%li, cookie="
127                         "0x%016lx, address=0x%016lx, len=0x%016lx\n",
128                         status, cookie, rp_pa, len);
129
130                 if (status != SALRET_MORE_PASSES) {
131                         break;
132                 }
133
134                 if (L1_CACHE_ALIGN(len) > buf_len) {
135                         kfree(buf_base);
136                         buf_len = L1_CACHE_ALIGN(len);
137                         buf = (u64) xpc_kmalloc_cacheline_aligned(buf_len,
138                                                         GFP_KERNEL, &buf_base);
139                         if (buf_base == NULL) {
140                                 dev_err(xpc_part, "unable to kmalloc "
141                                         "len=0x%016lx\n", buf_len);
142                                 status = SALRET_ERROR;
143                                 break;
144                         }
145                 }
146
147                 bte_res = xp_bte_copy(rp_pa, buf, buf_len,
148                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
149                 if (bte_res != BTE_SUCCESS) {
150                         dev_dbg(xpc_part, "xp_bte_copy failed %i\n", bte_res);
151                         status = SALRET_ERROR;
152                         break;
153                 }
154         }
155
156         kfree(buf_base);
157
158         if (status != SALRET_OK) {
159                 rp_pa = 0;
160         }
161         dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
162         return rp_pa;
163 }
164
165
166 /*
167  * Fill the partition reserved page with the information needed by
168  * other partitions to discover we are alive and establish initial
169  * communications.
170  */
171 struct xpc_rsvd_page *
172 xpc_rsvd_page_init(void)
173 {
174         struct xpc_rsvd_page *rp;
175         AMO_t *amos_page;
176         u64 rp_pa, nasid_array = 0;
177         int i, ret;
178
179
180         /* get the local reserved page's address */
181
182         preempt_disable();
183         rp_pa = xpc_get_rsvd_page_pa(cpuid_to_nasid(smp_processor_id()));
184         preempt_enable();
185         if (rp_pa == 0) {
186                 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
187                 return NULL;
188         }
189         rp = (struct xpc_rsvd_page *) __va(rp_pa);
190
191         if (rp->partid != sn_partition_id) {
192                 dev_err(xpc_part, "the reserved page's partid of %d should be "
193                         "%d\n", rp->partid, sn_partition_id);
194                 return NULL;
195         }
196
197         rp->version = XPC_RP_VERSION;
198
199         /* establish the actual sizes of the nasid masks */
200         if (rp->SAL_version == 1) {
201                 /* SAL_version 1 didn't set the nasids_size field */
202                 rp->nasids_size = 128;
203         }
204         xp_nasid_mask_bytes = rp->nasids_size;
205         xp_nasid_mask_words = xp_nasid_mask_bytes / 8;
206
207         /* setup the pointers to the various items in the reserved page */
208         xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
209         xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
210         xpc_vars = XPC_RP_VARS(rp);
211         xpc_vars_part = XPC_RP_VARS_PART(rp);
212
213         /*
214          * Before clearing xpc_vars, see if a page of AMOs had been previously
215          * allocated. If not we'll need to allocate one and set permissions
216          * so that cross-partition AMOs are allowed.
217          *
218          * The allocated AMO page needs MCA reporting to remain disabled after
219          * XPC has unloaded.  To make this work, we keep a copy of the pointer
220          * to this page (i.e., amos_page) in the struct xpc_vars structure,
221          * which is pointed to by the reserved page, and re-use that saved copy
222          * on subsequent loads of XPC. This AMO page is never freed, and its
223          * memory protections are never restricted.
224          */
225         if ((amos_page = xpc_vars->amos_page) == NULL) {
226                 amos_page = (AMO_t *) TO_AMO(uncached_alloc_page(0));
227                 if (amos_page == NULL) {
228                         dev_err(xpc_part, "can't allocate page of AMOs\n");
229                         return NULL;
230                 }
231
232                 /*
233                  * Open up AMO-R/W to cpu.  This is done for Shub 1.1 systems
234                  * when xpc_allow_IPI_ops() is called via xpc_hb_init().
235                  */
236                 if (!enable_shub_wars_1_1()) {
237                         ret = sn_change_memprotect(ia64_tpa((u64) amos_page),
238                                         PAGE_SIZE, SN_MEMPROT_ACCESS_CLASS_1,
239                                         &nasid_array);
240                         if (ret != 0) {
241                                 dev_err(xpc_part, "can't change memory "
242                                         "protections\n");
243                                 uncached_free_page(__IA64_UNCACHED_OFFSET |
244                                                    TO_PHYS((u64) amos_page));
245                                 return NULL;
246                         }
247                 }
248         } else if (!IS_AMO_ADDRESS((u64) amos_page)) {
249                 /*
250                  * EFI's XPBOOT can also set amos_page in the reserved page,
251                  * but it happens to leave it as an uncached physical address
252                  * and we need it to be an uncached virtual, so we'll have to
253                  * convert it.
254                  */
255                 if (!IS_AMO_PHYS_ADDRESS((u64) amos_page)) {
256                         dev_err(xpc_part, "previously used amos_page address "
257                                 "is bad = 0x%p\n", (void *) amos_page);
258                         return NULL;
259                 }
260                 amos_page = (AMO_t *) TO_AMO((u64) amos_page);
261         }
262
263         /* clear xpc_vars */
264         memset(xpc_vars, 0, sizeof(struct xpc_vars));
265
266         xpc_vars->version = XPC_V_VERSION;
267         xpc_vars->act_nasid = cpuid_to_nasid(0);
268         xpc_vars->act_phys_cpuid = cpu_physical_id(0);
269         xpc_vars->vars_part_pa = __pa(xpc_vars_part);
270         xpc_vars->amos_page_pa = ia64_tpa((u64) amos_page);
271         xpc_vars->amos_page = amos_page;  /* save for next load of XPC */
272
273
274         /* clear xpc_vars_part */
275         memset((u64 *) xpc_vars_part, 0, sizeof(struct xpc_vars_part) *
276                                                         XP_MAX_PARTITIONS);
277
278         /* initialize the activate IRQ related AMO variables */
279         for (i = 0; i < xp_nasid_mask_words; i++) {
280                 (void) xpc_IPI_init(XPC_ACTIVATE_IRQ_AMOS + i);
281         }
282
283         /* initialize the engaged remote partitions related AMO variables */
284         (void) xpc_IPI_init(XPC_ENGAGED_PARTITIONS_AMO);
285         (void) xpc_IPI_init(XPC_DISENGAGE_REQUEST_AMO);
286
287         /* timestamp of when reserved page was setup by XPC */
288         rp->stamp = CURRENT_TIME;
289
290         /*
291          * This signifies to the remote partition that our reserved
292          * page is initialized.
293          */
294         rp->vars_pa = __pa(xpc_vars);
295
296         return rp;
297 }
298
299
300 /*
301  * Change protections to allow IPI operations (and AMO operations on
302  * Shub 1.1 systems).
303  */
304 void
305 xpc_allow_IPI_ops(void)
306 {
307         int node;
308         int nasid;
309
310
311         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
312
313         if (is_shub2()) {
314                 xpc_sh2_IPI_access0 =
315                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS0));
316                 xpc_sh2_IPI_access1 =
317                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS1));
318                 xpc_sh2_IPI_access2 =
319                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS2));
320                 xpc_sh2_IPI_access3 =
321                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH2_IPI_ACCESS3));
322
323                 for_each_online_node(node) {
324                         nasid = cnodeid_to_nasid(node);
325                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
326                                                                 -1UL);
327                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
328                                                                 -1UL);
329                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
330                                                                 -1UL);
331                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
332                                                                 -1UL);
333                 }
334
335         } else {
336                 xpc_sh1_IPI_access =
337                         (u64) HUB_L((u64 *) LOCAL_MMR_ADDR(SH1_IPI_ACCESS));
338
339                 for_each_online_node(node) {
340                         nasid = cnodeid_to_nasid(node);
341                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
342                                                                 -1UL);
343
344                         /*
345                          * Since the BIST collides with memory operations on
346                          * SHUB 1.1 sn_change_memprotect() cannot be used.
347                          */
348                         if (enable_shub_wars_1_1()) {
349                                 /* open up everything */
350                                 xpc_prot_vec[node] = (u64) HUB_L((u64 *)
351                                                 GLOBAL_MMR_ADDR(nasid,
352                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0));
353                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
354                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
355                                                                 -1UL);
356                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
357                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
358                                                                 -1UL);
359                         }
360                 }
361         }
362 }
363
364
365 /*
366  * Restrict protections to disallow IPI operations (and AMO operations on
367  * Shub 1.1 systems).
368  */
369 void
370 xpc_restrict_IPI_ops(void)
371 {
372         int node;
373         int nasid;
374
375
376         // >>> Change SH_IPI_ACCESS code to use SAL call once it is available.
377
378         if (is_shub2()) {
379
380                 for_each_online_node(node) {
381                         nasid = cnodeid_to_nasid(node);
382                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS0),
383                                                         xpc_sh2_IPI_access0);
384                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS1),
385                                                         xpc_sh2_IPI_access1);
386                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS2),
387                                                         xpc_sh2_IPI_access2);
388                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH2_IPI_ACCESS3),
389                                                         xpc_sh2_IPI_access3);
390                 }
391
392         } else {
393
394                 for_each_online_node(node) {
395                         nasid = cnodeid_to_nasid(node);
396                         HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid, SH1_IPI_ACCESS),
397                                                         xpc_sh1_IPI_access);
398
399                         if (enable_shub_wars_1_1()) {
400                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
401                                                 SH1_MD_DQLP_MMR_DIR_PRIVEC0),
402                                                         xpc_prot_vec[node]);
403                                 HUB_S((u64 *) GLOBAL_MMR_ADDR(nasid,
404                                                 SH1_MD_DQRP_MMR_DIR_PRIVEC0),
405                                                         xpc_prot_vec[node]);
406                         }
407                 }
408         }
409 }
410
411
412 /*
413  * At periodic intervals, scan through all active partitions and ensure
414  * their heartbeat is still active.  If not, the partition is deactivated.
415  */
416 void
417 xpc_check_remote_hb(void)
418 {
419         struct xpc_vars *remote_vars;
420         struct xpc_partition *part;
421         partid_t partid;
422         bte_result_t bres;
423
424
425         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
426
427         for (partid = 1; partid < XP_MAX_PARTITIONS; partid++) {
428
429                 if (xpc_exiting) {
430                         break;
431                 }
432
433                 if (partid == sn_partition_id) {
434                         continue;
435                 }
436
437                 part = &xpc_partitions[partid];
438
439                 if (part->act_state == XPC_P_INACTIVE ||
440                                 part->act_state == XPC_P_DEACTIVATING) {
441                         continue;
442                 }
443
444                 /* pull the remote_hb cache line */
445                 bres = xp_bte_copy(part->remote_vars_pa,
446                                         (u64) remote_vars,
447                                         XPC_RP_VARS_SIZE,
448                                         (BTE_NOTIFY | BTE_WACQUIRE), NULL);
449                 if (bres != BTE_SUCCESS) {
450                         XPC_DEACTIVATE_PARTITION(part,
451                                                 xpc_map_bte_errors(bres));
452                         continue;
453                 }
454
455                 dev_dbg(xpc_part, "partid = %d, heartbeat = %ld, last_heartbeat"
456                         " = %ld, heartbeat_offline = %ld, HB_mask = 0x%lx\n",
457                         partid, remote_vars->heartbeat, part->last_heartbeat,
458                         remote_vars->heartbeat_offline,
459                         remote_vars->heartbeating_to_mask);
460
461                 if (((remote_vars->heartbeat == part->last_heartbeat) &&
462                         (remote_vars->heartbeat_offline == 0)) ||
463                              !xpc_hb_allowed(sn_partition_id, remote_vars)) {
464
465                         XPC_DEACTIVATE_PARTITION(part, xpcNoHeartbeat);
466                         continue;
467                 }
468
469                 part->last_heartbeat = remote_vars->heartbeat;
470         }
471 }
472
473
474 /*
475  * Get a copy of a portion of the remote partition's rsvd page.
476  *
477  * remote_rp points to a buffer that is cacheline aligned for BTE copies and
478  * is large enough to contain a copy of their reserved page header and
479  * part_nasids mask.
480  */
481 static enum xpc_retval
482 xpc_get_remote_rp(int nasid, u64 *discovered_nasids,
483                 struct xpc_rsvd_page *remote_rp, u64 *remote_rp_pa)
484 {
485         int bres, i;
486
487
488         /* get the reserved page's physical address */
489
490         *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
491         if (*remote_rp_pa == 0) {
492                 return xpcNoRsvdPageAddr;
493         }
494
495
496         /* pull over the reserved page header and part_nasids mask */
497         bres = xp_bte_copy(*remote_rp_pa, (u64) remote_rp,
498                                 XPC_RP_HEADER_SIZE + xp_nasid_mask_bytes,
499                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
500         if (bres != BTE_SUCCESS) {
501                 return xpc_map_bte_errors(bres);
502         }
503
504
505         if (discovered_nasids != NULL) {
506                 u64 *remote_part_nasids = XPC_RP_PART_NASIDS(remote_rp);
507
508
509                 for (i = 0; i < xp_nasid_mask_words; i++) {
510                         discovered_nasids[i] |= remote_part_nasids[i];
511                 }
512         }
513
514
515         /* check that the partid is for another partition */
516
517         if (remote_rp->partid < 1 ||
518                                 remote_rp->partid > (XP_MAX_PARTITIONS - 1)) {
519                 return xpcInvalidPartid;
520         }
521
522         if (remote_rp->partid == sn_partition_id) {
523                 return xpcLocalPartid;
524         }
525
526
527         if (XPC_VERSION_MAJOR(remote_rp->version) !=
528                                         XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
529                 return xpcBadVersion;
530         }
531
532         return xpcSuccess;
533 }
534
535
536 /*
537  * Get a copy of the remote partition's XPC variables from the reserved page.
538  *
539  * remote_vars points to a buffer that is cacheline aligned for BTE copies and
540  * assumed to be of size XPC_RP_VARS_SIZE.
541  */
542 static enum xpc_retval
543 xpc_get_remote_vars(u64 remote_vars_pa, struct xpc_vars *remote_vars)
544 {
545         int bres;
546
547
548         if (remote_vars_pa == 0) {
549                 return xpcVarsNotSet;
550         }
551
552         /* pull over the cross partition variables */
553         bres = xp_bte_copy(remote_vars_pa, (u64) remote_vars, XPC_RP_VARS_SIZE,
554                                 (BTE_NOTIFY | BTE_WACQUIRE), NULL);
555         if (bres != BTE_SUCCESS) {
556                 return xpc_map_bte_errors(bres);
557         }
558
559         if (XPC_VERSION_MAJOR(remote_vars->version) !=
560                                         XPC_VERSION_MAJOR(XPC_V_VERSION)) {
561                 return xpcBadVersion;
562         }
563
564         return xpcSuccess;
565 }
566
567
568 /*
569  * Update the remote partition's info.
570  */
571 static void
572 xpc_update_partition_info(struct xpc_partition *part, u8 remote_rp_version,
573                 struct timespec *remote_rp_stamp, u64 remote_rp_pa,
574                 u64 remote_vars_pa, struct xpc_vars *remote_vars)
575 {
576         part->remote_rp_version = remote_rp_version;
577         dev_dbg(xpc_part, "  remote_rp_version = 0x%016x\n",
578                 part->remote_rp_version);
579
580         part->remote_rp_stamp = *remote_rp_stamp;
581         dev_dbg(xpc_part, "  remote_rp_stamp (tv_sec = 0x%lx tv_nsec = 0x%lx\n",
582                 part->remote_rp_stamp.tv_sec, part->remote_rp_stamp.tv_nsec);
583
584         part->remote_rp_pa = remote_rp_pa;
585         dev_dbg(xpc_part, "  remote_rp_pa = 0x%016lx\n", part->remote_rp_pa);
586
587         part->remote_vars_pa = remote_vars_pa;
588         dev_dbg(xpc_part, "  remote_vars_pa = 0x%016lx\n",
589                 part->remote_vars_pa);
590
591         part->last_heartbeat = remote_vars->heartbeat;
592         dev_dbg(xpc_part, "  last_heartbeat = 0x%016lx\n",
593                 part->last_heartbeat);
594
595         part->remote_vars_part_pa = remote_vars->vars_part_pa;
596         dev_dbg(xpc_part, "  remote_vars_part_pa = 0x%016lx\n",
597                 part->remote_vars_part_pa);
598
599         part->remote_act_nasid = remote_vars->act_nasid;
600         dev_dbg(xpc_part, "  remote_act_nasid = 0x%x\n",
601                 part->remote_act_nasid);
602
603         part->remote_act_phys_cpuid = remote_vars->act_phys_cpuid;
604         dev_dbg(xpc_part, "  remote_act_phys_cpuid = 0x%x\n",
605                 part->remote_act_phys_cpuid);
606
607         part->remote_amos_page_pa = remote_vars->amos_page_pa;
608         dev_dbg(xpc_part, "  remote_amos_page_pa = 0x%lx\n",
609                 part->remote_amos_page_pa);
610
611         part->remote_vars_version = remote_vars->version;
612         dev_dbg(xpc_part, "  remote_vars_version = 0x%x\n",
613                 part->remote_vars_version);
614 }
615
616
617 /*
618  * Prior code has determined the nasid which generated an IPI.  Inspect
619  * that nasid to determine if its partition needs to be activated or
620  * deactivated.
621  *
622  * A partition is consider "awaiting activation" if our partition
623  * flags indicate it is not active and it has a heartbeat.  A
624  * partition is considered "awaiting deactivation" if our partition
625  * flags indicate it is active but it has no heartbeat or it is not
626  * sending its heartbeat to us.
627  *
628  * To determine the heartbeat, the remote nasid must have a properly
629  * initialized reserved page.
630  */
631 static void
632 xpc_identify_act_IRQ_req(int nasid)
633 {
634         struct xpc_rsvd_page *remote_rp;
635         struct xpc_vars *remote_vars;
636         u64 remote_rp_pa;
637         u64 remote_vars_pa;
638         int remote_rp_version;
639         int reactivate = 0;
640         int stamp_diff;
641         struct timespec remote_rp_stamp = { 0, 0 };
642         partid_t partid;
643         struct xpc_partition *part;
644         enum xpc_retval ret;
645
646
647         /* pull over the reserved page structure */
648
649         remote_rp = (struct xpc_rsvd_page *) xpc_remote_copy_buffer;
650
651         ret = xpc_get_remote_rp(nasid, NULL, remote_rp, &remote_rp_pa);
652         if (ret != xpcSuccess) {
653                 dev_warn(xpc_part, "unable to get reserved page from nasid %d, "
654                         "which sent interrupt, reason=%d\n", nasid, ret);
655                 return;
656         }
657
658         remote_vars_pa = remote_rp->vars_pa;
659         remote_rp_version = remote_rp->version;
660         if (XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
661                 remote_rp_stamp = remote_rp->stamp;
662         }
663         partid = remote_rp->partid;
664         part = &xpc_partitions[partid];
665
666
667         /* pull over the cross partition variables */
668
669         remote_vars = (struct xpc_vars *) xpc_remote_copy_buffer;
670
671         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
672         if (ret != xpcSuccess) {
673
674                 dev_warn(xpc_part, "unable to get XPC variables from nasid %d, "
675                         "which sent interrupt, reason=%d\n", nasid, ret);
676
677                 XPC_DEACTIVATE_PARTITION(part, ret);
678                 return;
679         }
680
681
682         part->act_IRQ_rcvd++;
683
684         dev_dbg(xpc_part, "partid for nasid %d is %d; IRQs = %d; HB = "
685                 "%ld:0x%lx\n", (int) nasid, (int) partid, part->act_IRQ_rcvd,
686                 remote_vars->heartbeat, remote_vars->heartbeating_to_mask);
687
688         if (xpc_partition_disengaged(part) &&
689                                         part->act_state == XPC_P_INACTIVE) {
690
691                 xpc_update_partition_info(part, remote_rp_version,
692                                         &remote_rp_stamp, remote_rp_pa,
693                                         remote_vars_pa, remote_vars);
694
695                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
696                         if (xpc_partition_disengage_requested(1UL << partid)) {
697                                 /*
698                                  * Other side is waiting on us to disengage,
699                                  * even though we already have.
700                                  */
701                                 return;
702                         }
703                 } else {
704                         /* other side doesn't support disengage requests */
705                         xpc_clear_partition_disengage_request(1UL << partid);
706                 }
707
708                 xpc_activate_partition(part);
709                 return;
710         }
711
712         DBUG_ON(part->remote_rp_version == 0);
713         DBUG_ON(part->remote_vars_version == 0);
714
715         if (!XPC_SUPPORTS_RP_STAMP(part->remote_rp_version)) {
716                 DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(part->
717                                                         remote_vars_version));
718
719                 if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
720                         DBUG_ON(XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
721                                                                 version));
722                         /* see if the other side rebooted */
723                         if (part->remote_amos_page_pa ==
724                                 remote_vars->amos_page_pa &&
725                                         xpc_hb_allowed(sn_partition_id,
726                                                                 remote_vars)) {
727                                 /* doesn't look that way, so ignore the IPI */
728                                 return;
729                         }
730                 }
731
732                 /*
733                  * Other side rebooted and previous XPC didn't support the
734                  * disengage request, so we don't need to do anything special.
735                  */
736
737                 xpc_update_partition_info(part, remote_rp_version,
738                                                 &remote_rp_stamp, remote_rp_pa,
739                                                 remote_vars_pa, remote_vars);
740                 part->reactivate_nasid = nasid;
741                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
742                 return;
743         }
744
745         DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version));
746
747         if (!XPC_SUPPORTS_RP_STAMP(remote_rp_version)) {
748                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
749
750                 /*
751                  * Other side rebooted and previous XPC did support the
752                  * disengage request, but the new one doesn't.
753                  */
754
755                 xpc_clear_partition_engaged(1UL << partid);
756                 xpc_clear_partition_disengage_request(1UL << partid);
757
758                 xpc_update_partition_info(part, remote_rp_version,
759                                                 &remote_rp_stamp, remote_rp_pa,
760                                                 remote_vars_pa, remote_vars);
761                 reactivate = 1;
762
763         } else {
764                 DBUG_ON(!XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->version));
765
766                 stamp_diff = xpc_compare_stamps(&part->remote_rp_stamp,
767                                                         &remote_rp_stamp);
768                 if (stamp_diff != 0) {
769                         DBUG_ON(stamp_diff >= 0);
770
771                         /*
772                          * Other side rebooted and the previous XPC did support
773                          * the disengage request, as does the new one.
774                          */
775
776                         DBUG_ON(xpc_partition_engaged(1UL << partid));
777                         DBUG_ON(xpc_partition_disengage_requested(1UL <<
778                                                                 partid));
779
780                         xpc_update_partition_info(part, remote_rp_version,
781                                                 &remote_rp_stamp, remote_rp_pa,
782                                                 remote_vars_pa, remote_vars);
783                         reactivate = 1;
784                 }
785         }
786
787         if (part->disengage_request_timeout > 0 &&
788                                         !xpc_partition_disengaged(part)) {
789                 /* still waiting on other side to disengage from us */
790                 return;
791         }
792
793         if (reactivate) {
794                 part->reactivate_nasid = nasid;
795                 XPC_DEACTIVATE_PARTITION(part, xpcReactivating);
796
797         } else if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version) &&
798                         xpc_partition_disengage_requested(1UL << partid)) {
799                 XPC_DEACTIVATE_PARTITION(part, xpcOtherGoingDown);
800         }
801 }
802
803
804 /*
805  * Loop through the activation AMO variables and process any bits
806  * which are set.  Each bit indicates a nasid sending a partition
807  * activation or deactivation request.
808  *
809  * Return #of IRQs detected.
810  */
811 int
812 xpc_identify_act_IRQ_sender(void)
813 {
814         int word, bit;
815         u64 nasid_mask;
816         u64 nasid;                      /* remote nasid */
817         int n_IRQs_detected = 0;
818         AMO_t *act_amos;
819
820
821         act_amos = xpc_vars->amos_page + XPC_ACTIVATE_IRQ_AMOS;
822
823
824         /* scan through act AMO variable looking for non-zero entries */
825         for (word = 0; word < xp_nasid_mask_words; word++) {
826
827                 if (xpc_exiting) {
828                         break;
829                 }
830
831                 nasid_mask = xpc_IPI_receive(&act_amos[word]);
832                 if (nasid_mask == 0) {
833                         /* no IRQs from nasids in this variable */
834                         continue;
835                 }
836
837                 dev_dbg(xpc_part, "AMO[%d] gave back 0x%lx\n", word,
838                         nasid_mask);
839
840
841                 /*
842                  * If this nasid has been added to the machine since
843                  * our partition was reset, this will retain the
844                  * remote nasid in our reserved pages machine mask.
845                  * This is used in the event of module reload.
846                  */
847                 xpc_mach_nasids[word] |= nasid_mask;
848
849
850                 /* locate the nasid(s) which sent interrupts */
851
852                 for (bit = 0; bit < (8 * sizeof(u64)); bit++) {
853                         if (nasid_mask & (1UL << bit)) {
854                                 n_IRQs_detected++;
855                                 nasid = XPC_NASID_FROM_W_B(word, bit);
856                                 dev_dbg(xpc_part, "interrupt from nasid %ld\n",
857                                         nasid);
858                                 xpc_identify_act_IRQ_req(nasid);
859                         }
860                 }
861         }
862         return n_IRQs_detected;
863 }
864
865
866 /*
867  * See if the other side has responded to a partition disengage request
868  * from us.
869  */
870 int
871 xpc_partition_disengaged(struct xpc_partition *part)
872 {
873         partid_t partid = XPC_PARTID(part);
874         int disengaged;
875
876
877         disengaged = (xpc_partition_engaged(1UL << partid) == 0);
878         if (part->disengage_request_timeout) {
879                 if (!disengaged) {
880                         if (time_before(jiffies, part->disengage_request_timeout)) {
881                                 /* timelimit hasn't been reached yet */
882                                 return 0;
883                         }
884
885                         /*
886                          * Other side hasn't responded to our disengage
887                          * request in a timely fashion, so assume it's dead.
888                          */
889
890                         dev_info(xpc_part, "disengage from remote partition %d "
891                                 "timed out\n", partid);
892                         xpc_disengage_request_timedout = 1;
893                         xpc_clear_partition_engaged(1UL << partid);
894                         disengaged = 1;
895                 }
896                 part->disengage_request_timeout = 0;
897
898                 /* cancel the timer function, provided it's not us */
899                 if (!in_interrupt()) {
900                         del_singleshot_timer_sync(&part->
901                                                       disengage_request_timer);
902                 }
903
904                 DBUG_ON(part->act_state != XPC_P_DEACTIVATING &&
905                                         part->act_state != XPC_P_INACTIVE);
906                 if (part->act_state != XPC_P_INACTIVE) {
907                         xpc_wakeup_channel_mgr(part);
908                 }
909
910                 if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
911                         xpc_cancel_partition_disengage_request(part);
912                 }
913         }
914         return disengaged;
915 }
916
917
918 /*
919  * Mark specified partition as active.
920  */
921 enum xpc_retval
922 xpc_mark_partition_active(struct xpc_partition *part)
923 {
924         unsigned long irq_flags;
925         enum xpc_retval ret;
926
927
928         dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
929
930         spin_lock_irqsave(&part->act_lock, irq_flags);
931         if (part->act_state == XPC_P_ACTIVATING) {
932                 part->act_state = XPC_P_ACTIVE;
933                 ret = xpcSuccess;
934         } else {
935                 DBUG_ON(part->reason == xpcSuccess);
936                 ret = part->reason;
937         }
938         spin_unlock_irqrestore(&part->act_lock, irq_flags);
939
940         return ret;
941 }
942
943
944 /*
945  * Notify XPC that the partition is down.
946  */
947 void
948 xpc_deactivate_partition(const int line, struct xpc_partition *part,
949                                 enum xpc_retval reason)
950 {
951         unsigned long irq_flags;
952
953
954         spin_lock_irqsave(&part->act_lock, irq_flags);
955
956         if (part->act_state == XPC_P_INACTIVE) {
957                 XPC_SET_REASON(part, reason, line);
958                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
959                 if (reason == xpcReactivating) {
960                         /* we interrupt ourselves to reactivate partition */
961                         xpc_IPI_send_reactivate(part);
962                 }
963                 return;
964         }
965         if (part->act_state == XPC_P_DEACTIVATING) {
966                 if ((part->reason == xpcUnloading && reason != xpcUnloading) ||
967                                         reason == xpcReactivating) {
968                         XPC_SET_REASON(part, reason, line);
969                 }
970                 spin_unlock_irqrestore(&part->act_lock, irq_flags);
971                 return;
972         }
973
974         part->act_state = XPC_P_DEACTIVATING;
975         XPC_SET_REASON(part, reason, line);
976
977         spin_unlock_irqrestore(&part->act_lock, irq_flags);
978
979         if (XPC_SUPPORTS_DISENGAGE_REQUEST(part->remote_vars_version)) {
980                 xpc_request_partition_disengage(part);
981                 xpc_IPI_send_disengage(part);
982
983                 /* set a timelimit on the disengage request */
984                 part->disengage_request_timeout = jiffies +
985                                         (xpc_disengage_request_timelimit * HZ);
986                 part->disengage_request_timer.expires =
987                                         part->disengage_request_timeout;
988                 add_timer(&part->disengage_request_timer);
989         }
990
991         dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
992                 XPC_PARTID(part), reason);
993
994         xpc_partition_going_down(part, reason);
995 }
996
997
998 /*
999  * Mark specified partition as inactive.
1000  */
1001 void
1002 xpc_mark_partition_inactive(struct xpc_partition *part)
1003 {
1004         unsigned long irq_flags;
1005
1006
1007         dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
1008                 XPC_PARTID(part));
1009
1010         spin_lock_irqsave(&part->act_lock, irq_flags);
1011         part->act_state = XPC_P_INACTIVE;
1012         spin_unlock_irqrestore(&part->act_lock, irq_flags);
1013         part->remote_rp_pa = 0;
1014 }
1015
1016
1017 /*
1018  * SAL has provided a partition and machine mask.  The partition mask
1019  * contains a bit for each even nasid in our partition.  The machine
1020  * mask contains a bit for each even nasid in the entire machine.
1021  *
1022  * Using those two bit arrays, we can determine which nasids are
1023  * known in the machine.  Each should also have a reserved page
1024  * initialized if they are available for partitioning.
1025  */
1026 void
1027 xpc_discovery(void)
1028 {
1029         void *remote_rp_base;
1030         struct xpc_rsvd_page *remote_rp;
1031         struct xpc_vars *remote_vars;
1032         u64 remote_rp_pa;
1033         u64 remote_vars_pa;
1034         int region;
1035         int region_size;
1036         int max_regions;
1037         int nasid;
1038         struct xpc_rsvd_page *rp;
1039         partid_t partid;
1040         struct xpc_partition *part;
1041         u64 *discovered_nasids;
1042         enum xpc_retval ret;
1043
1044
1045         remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
1046                                                 xp_nasid_mask_bytes,
1047                                                 GFP_KERNEL, &remote_rp_base);
1048         if (remote_rp == NULL) {
1049                 return;
1050         }
1051         remote_vars = (struct xpc_vars *) remote_rp;
1052
1053
1054         discovered_nasids = kzalloc(sizeof(u64) * xp_nasid_mask_words,
1055                                                         GFP_KERNEL);
1056         if (discovered_nasids == NULL) {
1057                 kfree(remote_rp_base);
1058                 return;
1059         }
1060
1061         rp = (struct xpc_rsvd_page *) xpc_rsvd_page;
1062
1063         /*
1064          * The term 'region' in this context refers to the minimum number of
1065          * nodes that can comprise an access protection grouping. The access
1066          * protection is in regards to memory, IOI and IPI.
1067          */
1068         max_regions = 64;
1069         region_size = sn_region_size;
1070
1071         switch (region_size) {
1072         case 128:
1073                 max_regions *= 2;
1074         case 64:
1075                 max_regions *= 2;
1076         case 32:
1077                 max_regions *= 2;
1078                 region_size = 16;
1079                 DBUG_ON(!is_shub2());
1080         }
1081
1082         for (region = 0; region < max_regions; region++) {
1083
1084                 if ((volatile int) xpc_exiting) {
1085                         break;
1086                 }
1087
1088                 dev_dbg(xpc_part, "searching region %d\n", region);
1089
1090                 for (nasid = (region * region_size * 2);
1091                      nasid < ((region + 1) * region_size * 2);
1092                      nasid += 2) {
1093
1094                         if ((volatile int) xpc_exiting) {
1095                                 break;
1096                         }
1097
1098                         dev_dbg(xpc_part, "checking nasid %d\n", nasid);
1099
1100
1101                         if (XPC_NASID_IN_ARRAY(nasid, xpc_part_nasids)) {
1102                                 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
1103                                         "part of the local partition; skipping "
1104                                         "region\n", nasid);
1105                                 break;
1106                         }
1107
1108                         if (!(XPC_NASID_IN_ARRAY(nasid, xpc_mach_nasids))) {
1109                                 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
1110                                         "not on Numa-Link network at reset\n",
1111                                         nasid);
1112                                 continue;
1113                         }
1114
1115                         if (XPC_NASID_IN_ARRAY(nasid, discovered_nasids)) {
1116                                 dev_dbg(xpc_part, "Nasid %d is part of a "
1117                                         "partition which was previously "
1118                                         "discovered\n", nasid);
1119                                 continue;
1120                         }
1121
1122
1123                         /* pull over the reserved page structure */
1124
1125                         ret = xpc_get_remote_rp(nasid, discovered_nasids,
1126                                               remote_rp, &remote_rp_pa);
1127                         if (ret != xpcSuccess) {
1128                                 dev_dbg(xpc_part, "unable to get reserved page "
1129                                         "from nasid %d, reason=%d\n", nasid,
1130                                         ret);
1131
1132                                 if (ret == xpcLocalPartid) {
1133                                         break;
1134                                 }
1135                                 continue;
1136                         }
1137
1138                         remote_vars_pa = remote_rp->vars_pa;
1139
1140                         partid = remote_rp->partid;
1141                         part = &xpc_partitions[partid];
1142
1143
1144                         /* pull over the cross partition variables */
1145
1146                         ret = xpc_get_remote_vars(remote_vars_pa, remote_vars);
1147                         if (ret != xpcSuccess) {
1148                                 dev_dbg(xpc_part, "unable to get XPC variables "
1149                                         "from nasid %d, reason=%d\n", nasid,
1150                                         ret);
1151
1152                                 XPC_DEACTIVATE_PARTITION(part, ret);
1153                                 continue;
1154                         }
1155
1156                         if (part->act_state != XPC_P_INACTIVE) {
1157                                 dev_dbg(xpc_part, "partition %d on nasid %d is "
1158                                         "already activating\n", partid, nasid);
1159                                 break;
1160                         }
1161
1162                         /*
1163                          * Register the remote partition's AMOs with SAL so it
1164                          * can handle and cleanup errors within that address
1165                          * range should the remote partition go down. We don't
1166                          * unregister this range because it is difficult to
1167                          * tell when outstanding writes to the remote partition
1168                          * are finished and thus when it is thus safe to
1169                          * unregister. This should not result in wasted space
1170                          * in the SAL xp_addr_region table because we should
1171                          * get the same page for remote_act_amos_pa after
1172                          * module reloads and system reboots.
1173                          */
1174                         if (sn_register_xp_addr_region(
1175                                             remote_vars->amos_page_pa,
1176                                                         PAGE_SIZE, 1) < 0) {
1177                                 dev_dbg(xpc_part, "partition %d failed to "
1178                                         "register xp_addr region 0x%016lx\n",
1179                                         partid, remote_vars->amos_page_pa);
1180
1181                                 XPC_SET_REASON(part, xpcPhysAddrRegFailed,
1182                                                 __LINE__);
1183                                 break;
1184                         }
1185
1186                         /*
1187                          * The remote nasid is valid and available.
1188                          * Send an interrupt to that nasid to notify
1189                          * it that we are ready to begin activation.
1190                          */
1191                         dev_dbg(xpc_part, "sending an interrupt to AMO 0x%lx, "
1192                                 "nasid %d, phys_cpuid 0x%x\n",
1193                                 remote_vars->amos_page_pa,
1194                                 remote_vars->act_nasid,
1195                                 remote_vars->act_phys_cpuid);
1196
1197                         if (XPC_SUPPORTS_DISENGAGE_REQUEST(remote_vars->
1198                                                                 version)) {
1199                                 part->remote_amos_page_pa =
1200                                                 remote_vars->amos_page_pa;
1201                                 xpc_mark_partition_disengaged(part);
1202                                 xpc_cancel_partition_disengage_request(part);
1203                         }
1204                         xpc_IPI_send_activate(remote_vars);
1205                 }
1206         }
1207
1208         kfree(discovered_nasids);
1209         kfree(remote_rp_base);
1210 }
1211
1212
1213 /*
1214  * Given a partid, get the nasids owned by that partition from the
1215  * remote partition's reserved page.
1216  */
1217 enum xpc_retval
1218 xpc_initiate_partid_to_nasids(partid_t partid, void *nasid_mask)
1219 {
1220         struct xpc_partition *part;
1221         u64 part_nasid_pa;
1222         int bte_res;
1223
1224
1225         part = &xpc_partitions[partid];
1226         if (part->remote_rp_pa == 0) {
1227                 return xpcPartitionDown;
1228         }
1229
1230         memset(nasid_mask, 0, XP_NASID_MASK_BYTES);
1231
1232         part_nasid_pa = (u64) XPC_RP_PART_NASIDS(part->remote_rp_pa);
1233
1234         bte_res = xp_bte_copy(part_nasid_pa, (u64) nasid_mask,
1235                         xp_nasid_mask_bytes, (BTE_NOTIFY | BTE_WACQUIRE), NULL);
1236
1237         return xpc_map_bte_errors(bte_res);
1238 }
1239