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 * (C) Copyright 2020 Hewlett Packard Enterprise Development LP
7 * Copyright (c) 2004-2008 Silicon Graphics, Inc. All Rights Reserved.
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 #include <linux/device.h>
20 #include <linux/hardirq.h>
21 #include <linux/slab.h>
22 #include "xpc.h"
23 #include <asm/uv/uv_hub.h>
24
25 /* XPC is exiting flag */
26 int xpc_exiting;
27
28 /* this partition's reserved page pointers */
29 struct xpc_rsvd_page *xpc_rsvd_page;
30 static unsigned long *xpc_part_nasids;
31 unsigned long *xpc_mach_nasids;
32
33 static int xpc_nasid_mask_nbytes; /* #of bytes in nasid mask */
34 int xpc_nasid_mask_nlongs; /* #of longs in nasid mask */
35
36 struct xpc_partition *xpc_partitions;
37
38 /*
39 * Guarantee that the kmalloc'd memory is cacheline aligned.
40 */
41 void *
xpc_kmalloc_cacheline_aligned(size_t size,gfp_t flags,void ** base)42 xpc_kmalloc_cacheline_aligned(size_t size, gfp_t flags, void **base)
43 {
44 /* see if kmalloc will give us cachline aligned memory by default */
45 *base = kmalloc(size, flags);
46 if (*base == NULL)
47 return NULL;
48
49 if ((u64)*base == L1_CACHE_ALIGN((u64)*base))
50 return *base;
51
52 kfree(*base);
53
54 /* nope, we'll have to do it ourselves */
55 *base = kmalloc(size + L1_CACHE_BYTES, flags);
56 if (*base == NULL)
57 return NULL;
58
59 return (void *)L1_CACHE_ALIGN((u64)*base);
60 }
61
62 /*
63 * Given a nasid, get the physical address of the partition's reserved page
64 * for that nasid. This function returns 0 on any error.
65 */
66 static unsigned long
xpc_get_rsvd_page_pa(int nasid)67 xpc_get_rsvd_page_pa(int nasid)
68 {
69 enum xp_retval ret;
70 u64 cookie = 0;
71 unsigned long rp_pa = nasid; /* seed with nasid */
72 size_t len = 0;
73 size_t buf_len = 0;
74 void *buf = NULL;
75 void *buf_base = NULL;
76 enum xp_retval (*get_partition_rsvd_page_pa)
77 (void *, u64 *, unsigned long *, size_t *) =
78 xpc_arch_ops.get_partition_rsvd_page_pa;
79
80 while (1) {
81
82 /* !!! rp_pa will need to be _gpa on UV.
83 * ??? So do we save it into the architecture specific parts
84 * ??? of the xpc_partition structure? Do we rename this
85 * ??? function or have two versions? Rename rp_pa for UV to
86 * ??? rp_gpa?
87 */
88 ret = get_partition_rsvd_page_pa(buf, &cookie, &rp_pa, &len);
89
90 dev_dbg(xpc_part, "SAL returned with ret=%d, cookie=0x%016lx, "
91 "address=0x%016lx, len=0x%016lx\n", ret,
92 (unsigned long)cookie, rp_pa, len);
93
94 if (ret != xpNeedMoreInfo)
95 break;
96
97 if (len > buf_len) {
98 kfree(buf_base);
99 buf_len = L1_CACHE_ALIGN(len);
100 buf = xpc_kmalloc_cacheline_aligned(buf_len, GFP_KERNEL,
101 &buf_base);
102 if (buf_base == NULL) {
103 dev_err(xpc_part, "unable to kmalloc "
104 "len=0x%016lx\n", buf_len);
105 ret = xpNoMemory;
106 break;
107 }
108 }
109
110 ret = xp_remote_memcpy(xp_pa(buf), rp_pa, len);
111 if (ret != xpSuccess) {
112 dev_dbg(xpc_part, "xp_remote_memcpy failed %d\n", ret);
113 break;
114 }
115 }
116
117 kfree(buf_base);
118
119 if (ret != xpSuccess)
120 rp_pa = 0;
121
122 dev_dbg(xpc_part, "reserved page at phys address 0x%016lx\n", rp_pa);
123 return rp_pa;
124 }
125
126 /*
127 * Fill the partition reserved page with the information needed by
128 * other partitions to discover we are alive and establish initial
129 * communications.
130 */
131 int
xpc_setup_rsvd_page(void)132 xpc_setup_rsvd_page(void)
133 {
134 int ret;
135 struct xpc_rsvd_page *rp;
136 unsigned long rp_pa;
137 unsigned long new_ts_jiffies;
138
139 /* get the local reserved page's address */
140
141 preempt_disable();
142 rp_pa = xpc_get_rsvd_page_pa(xp_cpu_to_nasid(smp_processor_id()));
143 preempt_enable();
144 if (rp_pa == 0) {
145 dev_err(xpc_part, "SAL failed to locate the reserved page\n");
146 return -ESRCH;
147 }
148 rp = (struct xpc_rsvd_page *)__va(xp_socket_pa(rp_pa));
149
150 if (rp->SAL_version < 3) {
151 /* SAL_versions < 3 had a SAL_partid defined as a u8 */
152 rp->SAL_partid &= 0xff;
153 }
154 BUG_ON(rp->SAL_partid != xp_partition_id);
155
156 if (rp->SAL_partid < 0 || rp->SAL_partid >= xp_max_npartitions) {
157 dev_err(xpc_part, "the reserved page's partid of %d is outside "
158 "supported range (< 0 || >= %d)\n", rp->SAL_partid,
159 xp_max_npartitions);
160 return -EINVAL;
161 }
162
163 rp->version = XPC_RP_VERSION;
164 rp->max_npartitions = xp_max_npartitions;
165
166 /* establish the actual sizes of the nasid masks */
167 if (rp->SAL_version == 1) {
168 /* SAL_version 1 didn't set the nasids_size field */
169 rp->SAL_nasids_size = 128;
170 }
171 xpc_nasid_mask_nbytes = rp->SAL_nasids_size;
172 xpc_nasid_mask_nlongs = BITS_TO_LONGS(rp->SAL_nasids_size *
173 BITS_PER_BYTE);
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
179 ret = xpc_arch_ops.setup_rsvd_page(rp);
180 if (ret != 0)
181 return ret;
182
183 /*
184 * Set timestamp of when reserved page was setup by XPC.
185 * This signifies to the remote partition that our reserved
186 * page is initialized.
187 */
188 new_ts_jiffies = jiffies;
189 if (new_ts_jiffies == 0 || new_ts_jiffies == rp->ts_jiffies)
190 new_ts_jiffies++;
191 rp->ts_jiffies = new_ts_jiffies;
192
193 xpc_rsvd_page = rp;
194 return 0;
195 }
196
197 void
xpc_teardown_rsvd_page(void)198 xpc_teardown_rsvd_page(void)
199 {
200 /* a zero timestamp indicates our rsvd page is not initialized */
201 xpc_rsvd_page->ts_jiffies = 0;
202 }
203
204 /*
205 * Get a copy of a portion of the remote partition's rsvd page.
206 *
207 * remote_rp points to a buffer that is cacheline aligned for BTE copies and
208 * is large enough to contain a copy of their reserved page header and
209 * part_nasids mask.
210 */
211 enum xp_retval
xpc_get_remote_rp(int nasid,unsigned long * discovered_nasids,struct xpc_rsvd_page * remote_rp,unsigned long * remote_rp_pa)212 xpc_get_remote_rp(int nasid, unsigned long *discovered_nasids,
213 struct xpc_rsvd_page *remote_rp, unsigned long *remote_rp_pa)
214 {
215 int l;
216 enum xp_retval ret;
217
218 /* get the reserved page's physical address */
219
220 *remote_rp_pa = xpc_get_rsvd_page_pa(nasid);
221 if (*remote_rp_pa == 0)
222 return xpNoRsvdPageAddr;
223
224 /* pull over the reserved page header and part_nasids mask */
225 ret = xp_remote_memcpy(xp_pa(remote_rp), *remote_rp_pa,
226 XPC_RP_HEADER_SIZE + xpc_nasid_mask_nbytes);
227 if (ret != xpSuccess)
228 return ret;
229
230 if (discovered_nasids != NULL) {
231 unsigned long *remote_part_nasids =
232 XPC_RP_PART_NASIDS(remote_rp);
233
234 for (l = 0; l < xpc_nasid_mask_nlongs; l++)
235 discovered_nasids[l] |= remote_part_nasids[l];
236 }
237
238 /* zero timestamp indicates the reserved page has not been setup */
239 if (remote_rp->ts_jiffies == 0)
240 return xpRsvdPageNotSet;
241
242 if (XPC_VERSION_MAJOR(remote_rp->version) !=
243 XPC_VERSION_MAJOR(XPC_RP_VERSION)) {
244 return xpBadVersion;
245 }
246
247 /* check that both remote and local partids are valid for each side */
248 if (remote_rp->SAL_partid < 0 ||
249 remote_rp->SAL_partid >= xp_max_npartitions ||
250 remote_rp->max_npartitions <= xp_partition_id) {
251 return xpInvalidPartid;
252 }
253
254 if (remote_rp->SAL_partid == xp_partition_id)
255 return xpLocalPartid;
256
257 return xpSuccess;
258 }
259
260 /*
261 * See if the other side has responded to a partition deactivate request
262 * from us. Though we requested the remote partition to deactivate with regard
263 * to us, we really only need to wait for the other side to disengage from us.
264 */
265 int
xpc_partition_disengaged(struct xpc_partition * part)266 xpc_partition_disengaged(struct xpc_partition *part)
267 {
268 short partid = XPC_PARTID(part);
269 int disengaged;
270
271 disengaged = !xpc_arch_ops.partition_engaged(partid);
272 if (part->disengage_timeout) {
273 if (!disengaged) {
274 if (time_is_after_jiffies(part->disengage_timeout)) {
275 /* timelimit hasn't been reached yet */
276 return 0;
277 }
278
279 /*
280 * Other side hasn't responded to our deactivate
281 * request in a timely fashion, so assume it's dead.
282 */
283
284 dev_info(xpc_part, "deactivate request to remote "
285 "partition %d timed out\n", partid);
286 xpc_disengage_timedout = 1;
287 xpc_arch_ops.assume_partition_disengaged(partid);
288 disengaged = 1;
289 }
290 part->disengage_timeout = 0;
291
292 /* cancel the timer function, provided it's not us */
293 if (!in_interrupt())
294 del_singleshot_timer_sync(&part->disengage_timer);
295
296 DBUG_ON(part->act_state != XPC_P_AS_DEACTIVATING &&
297 part->act_state != XPC_P_AS_INACTIVE);
298 if (part->act_state != XPC_P_AS_INACTIVE)
299 xpc_wakeup_channel_mgr(part);
300
301 xpc_arch_ops.cancel_partition_deactivation_request(part);
302 }
303 return disengaged;
304 }
305
306 /*
307 * Mark specified partition as active.
308 */
309 enum xp_retval
xpc_mark_partition_active(struct xpc_partition * part)310 xpc_mark_partition_active(struct xpc_partition *part)
311 {
312 unsigned long irq_flags;
313 enum xp_retval ret;
314
315 dev_dbg(xpc_part, "setting partition %d to ACTIVE\n", XPC_PARTID(part));
316
317 spin_lock_irqsave(&part->act_lock, irq_flags);
318 if (part->act_state == XPC_P_AS_ACTIVATING) {
319 part->act_state = XPC_P_AS_ACTIVE;
320 ret = xpSuccess;
321 } else {
322 DBUG_ON(part->reason == xpSuccess);
323 ret = part->reason;
324 }
325 spin_unlock_irqrestore(&part->act_lock, irq_flags);
326
327 return ret;
328 }
329
330 /*
331 * Start the process of deactivating the specified partition.
332 */
333 void
xpc_deactivate_partition(const int line,struct xpc_partition * part,enum xp_retval reason)334 xpc_deactivate_partition(const int line, struct xpc_partition *part,
335 enum xp_retval reason)
336 {
337 unsigned long irq_flags;
338
339 spin_lock_irqsave(&part->act_lock, irq_flags);
340
341 if (part->act_state == XPC_P_AS_INACTIVE) {
342 XPC_SET_REASON(part, reason, line);
343 spin_unlock_irqrestore(&part->act_lock, irq_flags);
344 if (reason == xpReactivating) {
345 /* we interrupt ourselves to reactivate partition */
346 xpc_arch_ops.request_partition_reactivation(part);
347 }
348 return;
349 }
350 if (part->act_state == XPC_P_AS_DEACTIVATING) {
351 if ((part->reason == xpUnloading && reason != xpUnloading) ||
352 reason == xpReactivating) {
353 XPC_SET_REASON(part, reason, line);
354 }
355 spin_unlock_irqrestore(&part->act_lock, irq_flags);
356 return;
357 }
358
359 part->act_state = XPC_P_AS_DEACTIVATING;
360 XPC_SET_REASON(part, reason, line);
361
362 spin_unlock_irqrestore(&part->act_lock, irq_flags);
363
364 /* ask remote partition to deactivate with regard to us */
365 xpc_arch_ops.request_partition_deactivation(part);
366
367 /* set a timelimit on the disengage phase of the deactivation request */
368 part->disengage_timeout = jiffies + (xpc_disengage_timelimit * HZ);
369 part->disengage_timer.expires = part->disengage_timeout;
370 add_timer(&part->disengage_timer);
371
372 dev_dbg(xpc_part, "bringing partition %d down, reason = %d\n",
373 XPC_PARTID(part), reason);
374
375 xpc_partition_going_down(part, reason);
376 }
377
378 /*
379 * Mark specified partition as inactive.
380 */
381 void
xpc_mark_partition_inactive(struct xpc_partition * part)382 xpc_mark_partition_inactive(struct xpc_partition *part)
383 {
384 unsigned long irq_flags;
385
386 dev_dbg(xpc_part, "setting partition %d to INACTIVE\n",
387 XPC_PARTID(part));
388
389 spin_lock_irqsave(&part->act_lock, irq_flags);
390 part->act_state = XPC_P_AS_INACTIVE;
391 spin_unlock_irqrestore(&part->act_lock, irq_flags);
392 part->remote_rp_pa = 0;
393 }
394
395 /*
396 * SAL has provided a partition and machine mask. The partition mask
397 * contains a bit for each even nasid in our partition. The machine
398 * mask contains a bit for each even nasid in the entire machine.
399 *
400 * Using those two bit arrays, we can determine which nasids are
401 * known in the machine. Each should also have a reserved page
402 * initialized if they are available for partitioning.
403 */
404 void
xpc_discovery(void)405 xpc_discovery(void)
406 {
407 void *remote_rp_base;
408 struct xpc_rsvd_page *remote_rp;
409 unsigned long remote_rp_pa;
410 int region;
411 int region_size;
412 int max_regions;
413 int nasid;
414 unsigned long *discovered_nasids;
415 enum xp_retval ret;
416
417 remote_rp = xpc_kmalloc_cacheline_aligned(XPC_RP_HEADER_SIZE +
418 xpc_nasid_mask_nbytes,
419 GFP_KERNEL, &remote_rp_base);
420 if (remote_rp == NULL)
421 return;
422
423 discovered_nasids = kcalloc(xpc_nasid_mask_nlongs, sizeof(long),
424 GFP_KERNEL);
425 if (discovered_nasids == NULL) {
426 kfree(remote_rp_base);
427 return;
428 }
429
430 /*
431 * The term 'region' in this context refers to the minimum number of
432 * nodes that can comprise an access protection grouping. The access
433 * protection is in regards to memory, IOI and IPI.
434 */
435 region_size = xp_region_size;
436
437 if (is_uv_system())
438 max_regions = 256;
439 else {
440 max_regions = 64;
441
442 switch (region_size) {
443 case 128:
444 max_regions *= 2;
445 fallthrough;
446 case 64:
447 max_regions *= 2;
448 fallthrough;
449 case 32:
450 max_regions *= 2;
451 region_size = 16;
452 }
453 }
454
455 for (region = 0; region < max_regions; region++) {
456
457 if (xpc_exiting)
458 break;
459
460 dev_dbg(xpc_part, "searching region %d\n", region);
461
462 for (nasid = (region * region_size * 2);
463 nasid < ((region + 1) * region_size * 2); nasid += 2) {
464
465 if (xpc_exiting)
466 break;
467
468 dev_dbg(xpc_part, "checking nasid %d\n", nasid);
469
470 if (test_bit(nasid / 2, xpc_part_nasids)) {
471 dev_dbg(xpc_part, "PROM indicates Nasid %d is "
472 "part of the local partition; skipping "
473 "region\n", nasid);
474 break;
475 }
476
477 if (!(test_bit(nasid / 2, xpc_mach_nasids))) {
478 dev_dbg(xpc_part, "PROM indicates Nasid %d was "
479 "not on Numa-Link network at reset\n",
480 nasid);
481 continue;
482 }
483
484 if (test_bit(nasid / 2, discovered_nasids)) {
485 dev_dbg(xpc_part, "Nasid %d is part of a "
486 "partition which was previously "
487 "discovered\n", nasid);
488 continue;
489 }
490
491 /* pull over the rsvd page header & part_nasids mask */
492
493 ret = xpc_get_remote_rp(nasid, discovered_nasids,
494 remote_rp, &remote_rp_pa);
495 if (ret != xpSuccess) {
496 dev_dbg(xpc_part, "unable to get reserved page "
497 "from nasid %d, reason=%d\n", nasid,
498 ret);
499
500 if (ret == xpLocalPartid)
501 break;
502
503 continue;
504 }
505
506 xpc_arch_ops.request_partition_activation(remote_rp,
507 remote_rp_pa, nasid);
508 }
509 }
510
511 kfree(discovered_nasids);
512 kfree(remote_rp_base);
513 }
514
515 /*
516 * Given a partid, get the nasids owned by that partition from the
517 * remote partition's reserved page.
518 */
519 enum xp_retval
xpc_initiate_partid_to_nasids(short partid,void * nasid_mask)520 xpc_initiate_partid_to_nasids(short partid, void *nasid_mask)
521 {
522 struct xpc_partition *part;
523 unsigned long part_nasid_pa;
524
525 part = &xpc_partitions[partid];
526 if (part->remote_rp_pa == 0)
527 return xpPartitionDown;
528
529 memset(nasid_mask, 0, xpc_nasid_mask_nbytes);
530
531 part_nasid_pa = (unsigned long)XPC_RP_PART_NASIDS(part->remote_rp_pa);
532
533 return xp_remote_memcpy(xp_pa(nasid_mask), part_nasid_pa,
534 xpc_nasid_mask_nbytes);
535 }
536