1 /*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (c) 2004-2008 Silicon Graphics, Inc. All Rights Reserved.
7 */
8
9 /*
10 * Cross Partition Communication (XPC) partition support.
11 *
12 * This is the part of XPC that detects the presence/absence of
13 * other partitions. It provides a heartbeat and monitors the
14 * heartbeats of other partitions.
15 *
16 */
17
18 #include <linux/device.h>
19 #include <linux/hardirq.h>
20 #include <linux/slab.h>
21 #include "xpc.h"
22 #include <asm/uv/uv_hub.h>
23
24 /* XPC is exiting flag */
25 int xpc_exiting;
26
27 /* this partition's reserved page pointers */
28 struct xpc_rsvd_page *xpc_rsvd_page;
29 static unsigned long *xpc_part_nasids;
30 unsigned long *xpc_mach_nasids;
31
32 static int xpc_nasid_mask_nbytes; /* #of bytes in nasid mask */
33 int xpc_nasid_mask_nlongs; /* #of longs in nasid mask */
34
35 struct xpc_partition *xpc_partitions;
36
37 /*
38 * Guarantee that the kmalloc'd memory is cacheline aligned.
39 */
40 void *
xpc_kmalloc_cacheline_aligned(size_t size,gfp_t flags,void ** base)41 xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
42 {
43 /* see if kmalloc will give us cachline aligned memory by default */
44 *base = kmalloc(size, flags);
45 if (*base == NULL)
46 return NULL;
47
48 if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
49 return *base;
50
51 kfree(*base);
52
53 /* nope, we'll have to do it ourselves */
54 *base = kmalloc(size + L1_CACHE_BYTES, flags);
55 if (*base == NULL)
56 return NULL;
57
58 return (void *)L1_CACHE_ALIGN((u64)*base);
59 }
60
61 /*
62 * Given a nasid, get the physical address of the partition's reserved page
63 * for that nasid. This function returns 0 on any error.
64 */
65 static unsigned long
xpc_get_rsvd_page_pa(int nasid)66 xpc_get_rsvd_page_pa(int nasid)
67 {
68 enum xp_retval ret;
69 u64 cookie = 0;
70 unsigned long rp_pa = nasid; /* seed with nasid */
71 size_t len = 0;
72 size_t buf_len = 0;
73 void *buf = buf;
74 void *buf_base = NULL;
75 enum xp_retval (*get_partition_rsvd_page_pa)
76 (void *, u64 *, unsigned long *, size_t *) =
77 xpc_arch_ops.get_partition_rsvd_page_pa;
78
79 while (1) {
80
81 /* !!! rp_pa will need to be _gpa on UV.
82 * ??? So do we save it into the architecture specific parts
83 * ??? of the xpc_partition structure? Do we rename this
84 * ??? function or have two versions? Rename rp_pa for UV to
85 * ??? rp_gpa?
86 */
87 ret = get_partition_rsvd_page_pa(buf, &cookie, &rp_pa, &len);
88
89 dev_dbg(xpc_part, "SAL returned with ret=%d, cookie=0x%016lx, "
90 "address=0x%016lx, len=0x%016lx\n", ret,
91 (unsigned long)cookie, rp_pa, len);
92
93 if (ret != xpNeedMoreInfo)
94 break;
95
96 /* !!! L1_CACHE_ALIGN() is only a sn2-bte_copy requirement */
97 if (is_shub())
98 len = L1_CACHE_ALIGN(len);
99
100 if (len > buf_len) {
101 if (buf_base != NULL)
102 kfree(buf_base);
103 buf_len = L1_CACHE_ALIGN(len);
104 buf = xpc_kmalloc_cacheline_aligned(buf_len, GFP_KERNEL,
105 &buf_base);
106 if (buf_base == NULL) {
107 dev_err(xpc_part, "unable to kmalloc "
108 "len=0x%016lx\n", buf_len);
109 ret = xpNoMemory;
110 break;
111 }
112 }
113
114 ret = xp_remote_memcpy(xp_pa(buf), rp_pa, len);
115 if (ret != xpSuccess) {
116 dev_dbg(xpc_part, "xp_remote_memcpy failed %d\n", ret);
117 break;
118 }
119 }
120
121 kfree(buf_base);
122
123 if (ret != xpSuccess)
124 rp_pa = 0;
125
126 dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
127 return rp_pa;
128 }
129
130 /*
131 * Fill the partition reserved page with the information needed by
132 * other partitions to discover we are alive and establish initial
133 * communications.
134 */
135 int
xpc_setup_rsvd_page(void)136 xpc_setup_rsvd_page(void)
137 {
138 int ret;
139 struct xpc_rsvd_page *rp;
140 unsigned long rp_pa;
141 unsigned long new_ts_jiffies;
142
143 /* get the local reserved page's address */
144
145 preempt_disable();
146 rp_pa = xpc_get_rsvd_page_pa(xp_cpu_to_nasid(smp_processor_id()));
147 preempt_enable();
148 if (rp_pa == 0) {
149 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
150 return -ESRCH;
151 }
152 rp = (struct xpc_rsvd_page *)__va(xp_socket_pa(rp_pa));
153
154 if (rp->SAL_version < 3) {
155 /* SAL_versions < 3 had a SAL_partid defined as a u8 */
156 rp->SAL_partid &= 0xff;
157 }
158 BUG_ON(rp->SAL_partid != xp_partition_id);
159
160 if (rp->SAL_partid < 0 || rp->SAL_partid >= xp_max_npartitions) {
161 dev_err(xpc_part, "the reserved page's partid of %d is outside "
162 "supported range (< 0 || >= %d)\n", rp->SAL_partid,
163 xp_max_npartitions);
164 return -EINVAL;
165 }
166
167 rp->version = XPC_RP_VERSION;
168 rp->max_npartitions = xp_max_npartitions;
169
170 /* establish the actual sizes of the nasid masks */
171 if (rp->SAL_version == 1) {
172 /* SAL_version 1 didn't set the nasids_size field */
173 rp->SAL_nasids_size = 128;
174 }
175 xpc_nasid_mask_nbytes = rp->SAL_nasids_size;
176 xpc_nasid_mask_nlongs = BITS_TO_LONGS(rp->SAL_nasids_size *
177 BITS_PER_BYTE);
178
179 /* setup the pointers to the various items in the reserved page */
180 xpc_part_nasids = XPC_RP_PART_NASIDS(rp);
181 xpc_mach_nasids = XPC_RP_MACH_NASIDS(rp);
182
183 ret = xpc_arch_ops.setup_rsvd_page(rp);
184 if (ret != 0)
185 return ret;
186
187 /*
188 * Set timestamp of when reserved page was setup by XPC.
189 * This signifies to the remote partition that our reserved
190 * page is initialized.
191 */
192 new_ts_jiffies = jiffies;
193 if (new_ts_jiffies == 0 || new_ts_jiffies == rp->ts_jiffies)
194 new_ts_jiffies++;
195 rp->ts_jiffies = new_ts_jiffies;
196
197 xpc_rsvd_page = rp;
198 return 0;
199 }
200
201 void
xpc_teardown_rsvd_page(void)202 xpc_teardown_rsvd_page(void)
203 {
204 /* a zero timestamp indicates our rsvd page is not initialized */
205 xpc_rsvd_page->ts_jiffies = 0;
206 }
207
208 /*
209 * Get a copy of a portion of the remote partition's rsvd page.
210 *
211 * remote_rp points to a buffer that is cacheline aligned for BTE copies and
212 * is large enough to contain a copy of their reserved page header and
213 * part_nasids mask.
214 */
215 enum xp_retval
xpc_get_remote_rp(int nasid,unsigned long * discovered_nasids,struct xpc_rsvd_page * remote_rp,unsigned long * remote_rp_pa)216 xpc_get_remote_rp(int nasid, unsigned long *discovered_nasids,
217 struct xpc_rsvd_page *remote_rp, unsigned long *remote_rp_pa)
218 {
219 int l;
220 enum xp_retval ret;
221
222 /* get the reserved page's physical address */
223
224 *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
225 if (*remote_rp_pa == 0)
226 return xpNoRsvdPageAddr;
227
228 /* pull over the reserved page header and part_nasids mask */
229 ret = xp_remote_memcpy(xp_pa(remote_rp), *remote_rp_pa,
230 XPC_RP_HEADER_SIZE + xpc_nasid_mask_nbytes);
231 if (ret != xpSuccess)
232 return ret;
233
234 if (discovered_nasids != NULL) {
235 unsigned long *remote_part_nasids =
236 XPC_RP_PART_NASIDS(remote_rp);
237
238 for (l = 0; l < xpc_nasid_mask_nlongs; l++)
239 discovered_nasids[l] |= remote_part_nasids[l];
240 }
241
242 /* zero timestamp indicates the reserved page has not been setup */
243 if (remote_rp->ts_jiffies == 0)
244 return xpRsvdPageNotSet;
245
246 if (XPC_VERSION_MAJOR(remote_rp->version) !=
247 XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
248 return xpBadVersion;
249 }
250
251 /* check that both remote and local partids are valid for each side */
252 if (remote_rp->SAL_partid < 0 ||
253 remote_rp->SAL_partid >= xp_max_npartitions ||
254 remote_rp->max_npartitions <= xp_partition_id) {
255 return xpInvalidPartid;
256 }
257
258 if (remote_rp->SAL_partid == xp_partition_id)
259 return xpLocalPartid;
260
261 return xpSuccess;
262 }
263
264 /*
265 * See if the other side has responded to a partition deactivate request
266 * from us. Though we requested the remote partition to deactivate with regard
267 * to us, we really only need to wait for the other side to disengage from us.
268 */
269 int
xpc_partition_disengaged(struct xpc_partition * part)270 xpc_partition_disengaged(struct xpc_partition *part)
271 {
272 short partid = XPC_PARTID(part);
273 int disengaged;
274
275 disengaged = !xpc_arch_ops.partition_engaged(partid);
276 if (part->disengage_timeout) {
277 if (!disengaged) {
278 if (time_is_after_jiffies(part->disengage_timeout)) {
279 /* timelimit hasn't been reached yet */
280 return 0;
281 }
282
283 /*
284 * Other side hasn't responded to our deactivate
285 * request in a timely fashion, so assume it's dead.
286 */
287
288 dev_info(xpc_part, "deactivate request to remote "
289 "partition %d timed out\n", partid);
290 xpc_disengage_timedout = 1;
291 xpc_arch_ops.assume_partition_disengaged(partid);
292 disengaged = 1;
293 }
294 part->disengage_timeout = 0;
295
296 /* cancel the timer function, provided it's not us */
297 if (!in_interrupt())
298 del_singleshot_timer_sync(&part->disengage_timer);
299
300 DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING &&
301 part->act_state != XPC_P_AS_INACTIVE);
302 if (part->act_state != XPC_P_AS_INACTIVE)
303 xpc_wakeup_channel_mgr(part);
304
305 xpc_arch_ops.cancel_partition_deactivation_request(part);
306 }
307 return disengaged;
308 }
309
310 /*
311 * Mark specified partition as active.
312 */
313 enum xp_retval
xpc_mark_partition_active(struct xpc_partition * part)314 xpc_mark_partition_active(struct xpc_partition *part)
315 {
316 unsigned long irq_flags;
317 enum xp_retval ret;
318
319 dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
320
321 spin_lock_irqsave(&part->act_lock, irq_flags);
322 if (part->act_state == XPC_P_AS_ACTIVATING) {
323 part->act_state = XPC_P_AS_ACTIVE;
324 ret = xpSuccess;
325 } else {
326 DBUG_ON(part->reason == xpSuccess);
327 ret = part->reason;
328 }
329 spin_unlock_irqrestore(&part->act_lock, irq_flags);
330
331 return ret;
332 }
333
334 /*
335 * Start the process of deactivating the specified partition.
336 */
337 void
xpc_deactivate_partition(const int line,struct xpc_partition * part,enum xp_retval reason)338 xpc_deactivate_partition(const int line, struct xpc_partition *part,
339 enum xp_retval reason)
340 {
341 unsigned long irq_flags;
342
343 spin_lock_irqsave(&part->act_lock, irq_flags);
344
345 if (part->act_state == XPC_P_AS_INACTIVE) {
346 XPC_SET_REASON(part, reason, line);
347 spin_unlock_irqrestore(&part->act_lock, irq_flags);
348 if (reason == xpReactivating) {
349 /* we interrupt ourselves to reactivate partition */
350 xpc_arch_ops.request_partition_reactivation(part);
351 }
352 return;
353 }
354 if (part->act_state == XPC_P_AS_DEACTIVATING) {
355 if ((part->reason == xpUnloading && reason != xpUnloading) ||
356 reason == xpReactivating) {
357 XPC_SET_REASON(part, reason, line);
358 }
359 spin_unlock_irqrestore(&part->act_lock, irq_flags);
360 return;
361 }
362
363 part->act_state = XPC_P_AS_DEACTIVATING;
364 XPC_SET_REASON(part, reason, line);
365
366 spin_unlock_irqrestore(&part->act_lock, irq_flags);
367
368 /* ask remote partition to deactivate with regard to us */
369 xpc_arch_ops.request_partition_deactivation(part);
370
371 /* set a timelimit on the disengage phase of the deactivation request */
372 part->disengage_timeout = jiffies + (xpc_disengage_timelimit * HZ);
373 part->disengage_timer.expires = part->disengage_timeout;
374 add_timer(&part->disengage_timer);
375
376 dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
377 XPC_PARTID(part), reason);
378
379 xpc_partition_going_down(part, reason);
380 }
381
382 /*
383 * Mark specified partition as inactive.
384 */
385 void
xpc_mark_partition_inactive(struct xpc_partition * part)386 xpc_mark_partition_inactive(struct xpc_partition *part)
387 {
388 unsigned long irq_flags;
389
390 dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
391 XPC_PARTID(part));
392
393 spin_lock_irqsave(&part->act_lock, irq_flags);
394 part->act_state = XPC_P_AS_INACTIVE;
395 spin_unlock_irqrestore(&part->act_lock, irq_flags);
396 part->remote_rp_pa = 0;
397 }
398
399 /*
400 * SAL has provided a partition and machine mask. The partition mask
401 * contains a bit for each even nasid in our partition. The machine
402 * mask contains a bit for each even nasid in the entire machine.
403 *
404 * Using those two bit arrays, we can determine which nasids are
405 * known in the machine. Each should also have a reserved page
406 * initialized if they are available for partitioning.
407 */
408 void
xpc_discovery(void)409 xpc_discovery(void)
410 {
411 void *remote_rp_base;
412 struct xpc_rsvd_page *remote_rp;
413 unsigned long remote_rp_pa;
414 int region;
415 int region_size;
416 int max_regions;
417 int nasid;
418 struct xpc_rsvd_page *rp;
419 unsigned long *discovered_nasids;
420 enum xp_retval ret;
421
422 remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
423 xpc_nasid_mask_nbytes,
424 GFP_KERNEL, &remote_rp_base);
425 if (remote_rp == NULL)
426 return;
427
428 discovered_nasids = kzalloc(sizeof(long) * xpc_nasid_mask_nlongs,
429 GFP_KERNEL);
430 if (discovered_nasids == NULL) {
431 kfree(remote_rp_base);
432 return;
433 }
434
435 rp = (struct xpc_rsvd_page *)xpc_rsvd_page;
436
437 /*
438 * The term 'region' in this context refers to the minimum number of
439 * nodes that can comprise an access protection grouping. The access
440 * protection is in regards to memory, IOI and IPI.
441 */
442 region_size = xp_region_size;
443
444 if (is_uv())
445 max_regions = 256;
446 else {
447 max_regions = 64;
448
449 switch (region_size) {
450 case 128:
451 max_regions *= 2;
452 case 64:
453 max_regions *= 2;
454 case 32:
455 max_regions *= 2;
456 region_size = 16;
457 DBUG_ON(!is_shub2());
458 }
459 }
460
461 for (region = 0; region < max_regions; region++) {
462
463 if (xpc_exiting)
464 break;
465
466 dev_dbg(xpc_part, "searching region %d\n", region);
467
468 for (nasid = (region * region_size * 2);
469 nasid < ((region + 1) * region_size * 2); nasid += 2) {
470
471 if (xpc_exiting)
472 break;
473
474 dev_dbg(xpc_part, "checking nasid %d\n", nasid);
475
476 if (test_bit(nasid / 2, xpc_part_nasids)) {
477 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
478 "part of the local partition; skipping "
479 "region\n", nasid);
480 break;
481 }
482
483 if (!(test_bit(nasid / 2, xpc_mach_nasids))) {
484 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
485 "not on Numa-Link network at reset\n",
486 nasid);
487 continue;
488 }
489
490 if (test_bit(nasid / 2, discovered_nasids)) {
491 dev_dbg(xpc_part, "Nasid %d is part of a "
492 "partition which was previously "
493 "discovered\n", nasid);
494 continue;
495 }
496
497 /* pull over the rsvd page header & part_nasids mask */
498
499 ret = xpc_get_remote_rp(nasid, discovered_nasids,
500 remote_rp, &remote_rp_pa);
501 if (ret != xpSuccess) {
502 dev_dbg(xpc_part, "unable to get reserved page "
503 "from nasid %d, reason=%d\n", nasid,
504 ret);
505
506 if (ret == xpLocalPartid)
507 break;
508
509 continue;
510 }
511
512 xpc_arch_ops.request_partition_activation(remote_rp,
513 remote_rp_pa, nasid);
514 }
515 }
516
517 kfree(discovered_nasids);
518 kfree(remote_rp_base);
519 }
520
521 /*
522 * Given a partid, get the nasids owned by that partition from the
523 * remote partition's reserved page.
524 */
525 enum xp_retval
xpc_initiate_partid_to_nasids(short partid,void * nasid_mask)526 xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
527 {
528 struct xpc_partition *part;
529 unsigned long part_nasid_pa;
530
531 part = &xpc_partitions[partid];
532 if (part->remote_rp_pa == 0)
533 return xpPartitionDown;
534
535 memset(nasid_mask, 0, xpc_nasid_mask_nbytes);
536
537 part_nasid_pa = (unsigned long)XPC_RP_PART_NASIDS(part->remote_rp_pa);
538
539 return xp_remote_memcpy(xp_pa(nasid_mask), part_nasid_pa,
540 xpc_nasid_mask_nbytes);
541 }
542