1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Hypervisor supplied "24x7" performance counter support
4 *
5 * Author: Cody P Schafer <cody@linux.vnet.ibm.com>
6 * Copyright 2014 IBM Corporation.
7 */
8
9 #define pr_fmt(fmt) "hv-24x7: " fmt
10
11 #include <linux/perf_event.h>
12 #include <linux/rbtree.h>
13 #include <linux/module.h>
14 #include <linux/slab.h>
15 #include <linux/vmalloc.h>
16
17 #include <asm/cputhreads.h>
18 #include <asm/firmware.h>
19 #include <asm/hvcall.h>
20 #include <asm/io.h>
21 #include <linux/byteorder/generic.h>
22
23 #include "hv-24x7.h"
24 #include "hv-24x7-catalog.h"
25 #include "hv-common.h"
26
27 /* Version of the 24x7 hypervisor API that we should use in this machine. */
28 static int interface_version;
29
30 /* Whether we have to aggregate result data for some domains. */
31 static bool aggregate_result_elements;
32
domain_is_valid(unsigned domain)33 static bool domain_is_valid(unsigned domain)
34 {
35 switch (domain) {
36 #define DOMAIN(n, v, x, c) \
37 case HV_PERF_DOMAIN_##n: \
38 /* fall through */
39 #include "hv-24x7-domains.h"
40 #undef DOMAIN
41 return true;
42 default:
43 return false;
44 }
45 }
46
is_physical_domain(unsigned domain)47 static bool is_physical_domain(unsigned domain)
48 {
49 switch (domain) {
50 #define DOMAIN(n, v, x, c) \
51 case HV_PERF_DOMAIN_##n: \
52 return c;
53 #include "hv-24x7-domains.h"
54 #undef DOMAIN
55 default:
56 return false;
57 }
58 }
59
60 /* Domains for which more than one result element are returned for each event. */
domain_needs_aggregation(unsigned int domain)61 static bool domain_needs_aggregation(unsigned int domain)
62 {
63 return aggregate_result_elements &&
64 (domain == HV_PERF_DOMAIN_PHYS_CORE ||
65 (domain >= HV_PERF_DOMAIN_VCPU_HOME_CORE &&
66 domain <= HV_PERF_DOMAIN_VCPU_REMOTE_NODE));
67 }
68
domain_name(unsigned domain)69 static const char *domain_name(unsigned domain)
70 {
71 if (!domain_is_valid(domain))
72 return NULL;
73
74 switch (domain) {
75 case HV_PERF_DOMAIN_PHYS_CHIP: return "Physical Chip";
76 case HV_PERF_DOMAIN_PHYS_CORE: return "Physical Core";
77 case HV_PERF_DOMAIN_VCPU_HOME_CORE: return "VCPU Home Core";
78 case HV_PERF_DOMAIN_VCPU_HOME_CHIP: return "VCPU Home Chip";
79 case HV_PERF_DOMAIN_VCPU_HOME_NODE: return "VCPU Home Node";
80 case HV_PERF_DOMAIN_VCPU_REMOTE_NODE: return "VCPU Remote Node";
81 }
82
83 WARN_ON_ONCE(domain);
84 return NULL;
85 }
86
catalog_entry_domain_is_valid(unsigned domain)87 static bool catalog_entry_domain_is_valid(unsigned domain)
88 {
89 /* POWER8 doesn't support virtual domains. */
90 if (interface_version == 1)
91 return is_physical_domain(domain);
92 else
93 return domain_is_valid(domain);
94 }
95
96 /*
97 * TODO: Merging events:
98 * - Think of the hcall as an interface to a 4d array of counters:
99 * - x = domains
100 * - y = indexes in the domain (core, chip, vcpu, node, etc)
101 * - z = offset into the counter space
102 * - w = lpars (guest vms, "logical partitions")
103 * - A single request is: x,y,y_last,z,z_last,w,w_last
104 * - this means we can retrieve a rectangle of counters in y,z for a single x.
105 *
106 * - Things to consider (ignoring w):
107 * - input cost_per_request = 16
108 * - output cost_per_result(ys,zs) = 8 + 8 * ys + ys * zs
109 * - limited number of requests per hcall (must fit into 4K bytes)
110 * - 4k = 16 [buffer header] - 16 [request size] * request_count
111 * - 255 requests per hcall
112 * - sometimes it will be more efficient to read extra data and discard
113 */
114
115 /*
116 * Example usage:
117 * perf stat -e 'hv_24x7/domain=2,offset=8,vcpu=0,lpar=0xffffffff/'
118 */
119
120 /* u3 0-6, one of HV_24X7_PERF_DOMAIN */
121 EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3);
122 /* u16 */
123 EVENT_DEFINE_RANGE_FORMAT(core, config, 16, 31);
124 EVENT_DEFINE_RANGE_FORMAT(chip, config, 16, 31);
125 EVENT_DEFINE_RANGE_FORMAT(vcpu, config, 16, 31);
126 /* u32, see "data_offset" */
127 EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63);
128 /* u16 */
129 EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15);
130
131 EVENT_DEFINE_RANGE(reserved1, config, 4, 15);
132 EVENT_DEFINE_RANGE(reserved2, config1, 16, 63);
133 EVENT_DEFINE_RANGE(reserved3, config2, 0, 63);
134
135 static struct attribute *format_attrs[] = {
136 &format_attr_domain.attr,
137 &format_attr_offset.attr,
138 &format_attr_core.attr,
139 &format_attr_chip.attr,
140 &format_attr_vcpu.attr,
141 &format_attr_lpar.attr,
142 NULL,
143 };
144
145 static struct attribute_group format_group = {
146 .name = "format",
147 .attrs = format_attrs,
148 };
149
150 static struct attribute_group event_group = {
151 .name = "events",
152 /* .attrs is set in init */
153 };
154
155 static struct attribute_group event_desc_group = {
156 .name = "event_descs",
157 /* .attrs is set in init */
158 };
159
160 static struct attribute_group event_long_desc_group = {
161 .name = "event_long_descs",
162 /* .attrs is set in init */
163 };
164
165 static struct kmem_cache *hv_page_cache;
166
167 DEFINE_PER_CPU(int, hv_24x7_txn_flags);
168 DEFINE_PER_CPU(int, hv_24x7_txn_err);
169
170 struct hv_24x7_hw {
171 struct perf_event *events[255];
172 };
173
174 DEFINE_PER_CPU(struct hv_24x7_hw, hv_24x7_hw);
175
176 /*
177 * request_buffer and result_buffer are not required to be 4k aligned,
178 * but are not allowed to cross any 4k boundary. Aligning them to 4k is
179 * the simplest way to ensure that.
180 */
181 #define H24x7_DATA_BUFFER_SIZE 4096
182 DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
183 DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
184
max_num_requests(int interface_version)185 static unsigned int max_num_requests(int interface_version)
186 {
187 return (H24x7_DATA_BUFFER_SIZE - sizeof(struct hv_24x7_request_buffer))
188 / H24x7_REQUEST_SIZE(interface_version);
189 }
190
event_name(struct hv_24x7_event_data * ev,int * len)191 static char *event_name(struct hv_24x7_event_data *ev, int *len)
192 {
193 *len = be16_to_cpu(ev->event_name_len) - 2;
194 return (char *)ev->remainder;
195 }
196
event_desc(struct hv_24x7_event_data * ev,int * len)197 static char *event_desc(struct hv_24x7_event_data *ev, int *len)
198 {
199 unsigned nl = be16_to_cpu(ev->event_name_len);
200 __be16 *desc_len = (__be16 *)(ev->remainder + nl - 2);
201
202 *len = be16_to_cpu(*desc_len) - 2;
203 return (char *)ev->remainder + nl;
204 }
205
event_long_desc(struct hv_24x7_event_data * ev,int * len)206 static char *event_long_desc(struct hv_24x7_event_data *ev, int *len)
207 {
208 unsigned nl = be16_to_cpu(ev->event_name_len);
209 __be16 *desc_len_ = (__be16 *)(ev->remainder + nl - 2);
210 unsigned desc_len = be16_to_cpu(*desc_len_);
211 __be16 *long_desc_len = (__be16 *)(ev->remainder + nl + desc_len - 2);
212
213 *len = be16_to_cpu(*long_desc_len) - 2;
214 return (char *)ev->remainder + nl + desc_len;
215 }
216
event_fixed_portion_is_within(struct hv_24x7_event_data * ev,void * end)217 static bool event_fixed_portion_is_within(struct hv_24x7_event_data *ev,
218 void *end)
219 {
220 void *start = ev;
221
222 return (start + offsetof(struct hv_24x7_event_data, remainder)) < end;
223 }
224
225 /*
226 * Things we don't check:
227 * - padding for desc, name, and long/detailed desc is required to be '\0'
228 * bytes.
229 *
230 * Return NULL if we pass end,
231 * Otherwise return the address of the byte just following the event.
232 */
event_end(struct hv_24x7_event_data * ev,void * end)233 static void *event_end(struct hv_24x7_event_data *ev, void *end)
234 {
235 void *start = ev;
236 __be16 *dl_, *ldl_;
237 unsigned dl, ldl;
238 unsigned nl = be16_to_cpu(ev->event_name_len);
239
240 if (nl < 2) {
241 pr_debug("%s: name length too short: %d", __func__, nl);
242 return NULL;
243 }
244
245 if (start + nl > end) {
246 pr_debug("%s: start=%p + nl=%u > end=%p",
247 __func__, start, nl, end);
248 return NULL;
249 }
250
251 dl_ = (__be16 *)(ev->remainder + nl - 2);
252 if (!IS_ALIGNED((uintptr_t)dl_, 2))
253 pr_warn("desc len not aligned %p", dl_);
254 dl = be16_to_cpu(*dl_);
255 if (dl < 2) {
256 pr_debug("%s: desc len too short: %d", __func__, dl);
257 return NULL;
258 }
259
260 if (start + nl + dl > end) {
261 pr_debug("%s: (start=%p + nl=%u + dl=%u)=%p > end=%p",
262 __func__, start, nl, dl, start + nl + dl, end);
263 return NULL;
264 }
265
266 ldl_ = (__be16 *)(ev->remainder + nl + dl - 2);
267 if (!IS_ALIGNED((uintptr_t)ldl_, 2))
268 pr_warn("long desc len not aligned %p", ldl_);
269 ldl = be16_to_cpu(*ldl_);
270 if (ldl < 2) {
271 pr_debug("%s: long desc len too short (ldl=%u)",
272 __func__, ldl);
273 return NULL;
274 }
275
276 if (start + nl + dl + ldl > end) {
277 pr_debug("%s: start=%p + nl=%u + dl=%u + ldl=%u > end=%p",
278 __func__, start, nl, dl, ldl, end);
279 return NULL;
280 }
281
282 return start + nl + dl + ldl;
283 }
284
h_get_24x7_catalog_page_(unsigned long phys_4096,unsigned long version,unsigned long index)285 static long h_get_24x7_catalog_page_(unsigned long phys_4096,
286 unsigned long version, unsigned long index)
287 {
288 pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)",
289 phys_4096, version, index);
290
291 WARN_ON(!IS_ALIGNED(phys_4096, 4096));
292
293 return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE,
294 phys_4096, version, index);
295 }
296
h_get_24x7_catalog_page(char page[],u64 version,u32 index)297 static long h_get_24x7_catalog_page(char page[], u64 version, u32 index)
298 {
299 return h_get_24x7_catalog_page_(virt_to_phys(page),
300 version, index);
301 }
302
303 /*
304 * Each event we find in the catalog, will have a sysfs entry. Format the
305 * data for this sysfs entry based on the event's domain.
306 *
307 * Events belonging to the Chip domain can only be monitored in that domain.
308 * i.e the domain for these events is a fixed/knwon value.
309 *
310 * Events belonging to the Core domain can be monitored either in the physical
311 * core or in one of the virtual CPU domains. So the domain value for these
312 * events must be specified by the user (i.e is a required parameter). Format
313 * the Core events with 'domain=?' so the perf-tool can error check required
314 * parameters.
315 *
316 * NOTE: For the Core domain events, rather than making domain a required
317 * parameter we could default it to PHYS_CORE and allowe users to
318 * override the domain to one of the VCPU domains.
319 *
320 * However, this can make the interface a little inconsistent.
321 *
322 * If we set domain=2 (PHYS_CHIP) and allow user to override this field
323 * the user may be tempted to also modify the "offset=x" field in which
324 * can lead to confusing usage. Consider the HPM_PCYC (offset=0x18) and
325 * HPM_INST (offset=0x20) events. With:
326 *
327 * perf stat -e hv_24x7/HPM_PCYC,offset=0x20/
328 *
329 * we end up monitoring HPM_INST, while the command line has HPM_PCYC.
330 *
331 * By not assigning a default value to the domain for the Core events,
332 * we can have simple guidelines:
333 *
334 * - Specifying values for parameters with "=?" is required.
335 *
336 * - Specifying (i.e overriding) values for other parameters
337 * is undefined.
338 */
event_fmt(struct hv_24x7_event_data * event,unsigned domain)339 static char *event_fmt(struct hv_24x7_event_data *event, unsigned domain)
340 {
341 const char *sindex;
342 const char *lpar;
343 const char *domain_str;
344 char buf[8];
345
346 switch (domain) {
347 case HV_PERF_DOMAIN_PHYS_CHIP:
348 snprintf(buf, sizeof(buf), "%d", domain);
349 domain_str = buf;
350 lpar = "0x0";
351 sindex = "chip";
352 break;
353 case HV_PERF_DOMAIN_PHYS_CORE:
354 domain_str = "?";
355 lpar = "0x0";
356 sindex = "core";
357 break;
358 default:
359 domain_str = "?";
360 lpar = "?";
361 sindex = "vcpu";
362 }
363
364 return kasprintf(GFP_KERNEL,
365 "domain=%s,offset=0x%x,%s=?,lpar=%s",
366 domain_str,
367 be16_to_cpu(event->event_counter_offs) +
368 be16_to_cpu(event->event_group_record_offs),
369 sindex,
370 lpar);
371 }
372
373 /* Avoid trusting fw to NUL terminate strings */
memdup_to_str(char * maybe_str,int max_len,gfp_t gfp)374 static char *memdup_to_str(char *maybe_str, int max_len, gfp_t gfp)
375 {
376 return kasprintf(gfp, "%.*s", max_len, maybe_str);
377 }
378
device_show_string(struct device * dev,struct device_attribute * attr,char * buf)379 static ssize_t device_show_string(struct device *dev,
380 struct device_attribute *attr, char *buf)
381 {
382 struct dev_ext_attribute *d;
383
384 d = container_of(attr, struct dev_ext_attribute, attr);
385
386 return sprintf(buf, "%s\n", (char *)d->var);
387 }
388
device_str_attr_create_(char * name,char * str)389 static struct attribute *device_str_attr_create_(char *name, char *str)
390 {
391 struct dev_ext_attribute *attr = kzalloc(sizeof(*attr), GFP_KERNEL);
392
393 if (!attr)
394 return NULL;
395
396 sysfs_attr_init(&attr->attr.attr);
397
398 attr->var = str;
399 attr->attr.attr.name = name;
400 attr->attr.attr.mode = 0444;
401 attr->attr.show = device_show_string;
402
403 return &attr->attr.attr;
404 }
405
406 /*
407 * Allocate and initialize strings representing event attributes.
408 *
409 * NOTE: The strings allocated here are never destroyed and continue to
410 * exist till shutdown. This is to allow us to create as many events
411 * from the catalog as possible, even if we encounter errors with some.
412 * In case of changes to error paths in future, these may need to be
413 * freed by the caller.
414 */
device_str_attr_create(char * name,int name_max,int name_nonce,char * str,size_t str_max)415 static struct attribute *device_str_attr_create(char *name, int name_max,
416 int name_nonce,
417 char *str, size_t str_max)
418 {
419 char *n;
420 char *s = memdup_to_str(str, str_max, GFP_KERNEL);
421 struct attribute *a;
422
423 if (!s)
424 return NULL;
425
426 if (!name_nonce)
427 n = kasprintf(GFP_KERNEL, "%.*s", name_max, name);
428 else
429 n = kasprintf(GFP_KERNEL, "%.*s__%d", name_max, name,
430 name_nonce);
431 if (!n)
432 goto out_s;
433
434 a = device_str_attr_create_(n, s);
435 if (!a)
436 goto out_n;
437
438 return a;
439 out_n:
440 kfree(n);
441 out_s:
442 kfree(s);
443 return NULL;
444 }
445
event_to_attr(unsigned ix,struct hv_24x7_event_data * event,unsigned domain,int nonce)446 static struct attribute *event_to_attr(unsigned ix,
447 struct hv_24x7_event_data *event,
448 unsigned domain,
449 int nonce)
450 {
451 int event_name_len;
452 char *ev_name, *a_ev_name, *val;
453 struct attribute *attr;
454
455 if (!domain_is_valid(domain)) {
456 pr_warn("catalog event %u has invalid domain %u\n",
457 ix, domain);
458 return NULL;
459 }
460
461 val = event_fmt(event, domain);
462 if (!val)
463 return NULL;
464
465 ev_name = event_name(event, &event_name_len);
466 if (!nonce)
467 a_ev_name = kasprintf(GFP_KERNEL, "%.*s",
468 (int)event_name_len, ev_name);
469 else
470 a_ev_name = kasprintf(GFP_KERNEL, "%.*s__%d",
471 (int)event_name_len, ev_name, nonce);
472
473 if (!a_ev_name)
474 goto out_val;
475
476 attr = device_str_attr_create_(a_ev_name, val);
477 if (!attr)
478 goto out_name;
479
480 return attr;
481 out_name:
482 kfree(a_ev_name);
483 out_val:
484 kfree(val);
485 return NULL;
486 }
487
event_to_desc_attr(struct hv_24x7_event_data * event,int nonce)488 static struct attribute *event_to_desc_attr(struct hv_24x7_event_data *event,
489 int nonce)
490 {
491 int nl, dl;
492 char *name = event_name(event, &nl);
493 char *desc = event_desc(event, &dl);
494
495 /* If there isn't a description, don't create the sysfs file */
496 if (!dl)
497 return NULL;
498
499 return device_str_attr_create(name, nl, nonce, desc, dl);
500 }
501
502 static struct attribute *
event_to_long_desc_attr(struct hv_24x7_event_data * event,int nonce)503 event_to_long_desc_attr(struct hv_24x7_event_data *event, int nonce)
504 {
505 int nl, dl;
506 char *name = event_name(event, &nl);
507 char *desc = event_long_desc(event, &dl);
508
509 /* If there isn't a description, don't create the sysfs file */
510 if (!dl)
511 return NULL;
512
513 return device_str_attr_create(name, nl, nonce, desc, dl);
514 }
515
event_data_to_attrs(unsigned ix,struct attribute ** attrs,struct hv_24x7_event_data * event,int nonce)516 static int event_data_to_attrs(unsigned ix, struct attribute **attrs,
517 struct hv_24x7_event_data *event, int nonce)
518 {
519 *attrs = event_to_attr(ix, event, event->domain, nonce);
520 if (!*attrs)
521 return -1;
522
523 return 0;
524 }
525
526 /* */
527 struct event_uniq {
528 struct rb_node node;
529 const char *name;
530 int nl;
531 unsigned ct;
532 unsigned domain;
533 };
534
memord(const void * d1,size_t s1,const void * d2,size_t s2)535 static int memord(const void *d1, size_t s1, const void *d2, size_t s2)
536 {
537 if (s1 < s2)
538 return 1;
539 if (s1 > s2)
540 return -1;
541
542 return memcmp(d1, d2, s1);
543 }
544
ev_uniq_ord(const void * v1,size_t s1,unsigned d1,const void * v2,size_t s2,unsigned d2)545 static int ev_uniq_ord(const void *v1, size_t s1, unsigned d1, const void *v2,
546 size_t s2, unsigned d2)
547 {
548 int r = memord(v1, s1, v2, s2);
549
550 if (r)
551 return r;
552 if (d1 > d2)
553 return 1;
554 if (d2 > d1)
555 return -1;
556 return 0;
557 }
558
event_uniq_add(struct rb_root * root,const char * name,int nl,unsigned domain)559 static int event_uniq_add(struct rb_root *root, const char *name, int nl,
560 unsigned domain)
561 {
562 struct rb_node **new = &(root->rb_node), *parent = NULL;
563 struct event_uniq *data;
564
565 /* Figure out where to put new node */
566 while (*new) {
567 struct event_uniq *it;
568 int result;
569
570 it = rb_entry(*new, struct event_uniq, node);
571 result = ev_uniq_ord(name, nl, domain, it->name, it->nl,
572 it->domain);
573
574 parent = *new;
575 if (result < 0)
576 new = &((*new)->rb_left);
577 else if (result > 0)
578 new = &((*new)->rb_right);
579 else {
580 it->ct++;
581 pr_info("found a duplicate event %.*s, ct=%u\n", nl,
582 name, it->ct);
583 return it->ct;
584 }
585 }
586
587 data = kmalloc(sizeof(*data), GFP_KERNEL);
588 if (!data)
589 return -ENOMEM;
590
591 *data = (struct event_uniq) {
592 .name = name,
593 .nl = nl,
594 .ct = 0,
595 .domain = domain,
596 };
597
598 /* Add new node and rebalance tree. */
599 rb_link_node(&data->node, parent, new);
600 rb_insert_color(&data->node, root);
601
602 /* data->ct */
603 return 0;
604 }
605
event_uniq_destroy(struct rb_root * root)606 static void event_uniq_destroy(struct rb_root *root)
607 {
608 /*
609 * the strings we point to are in the giant block of memory filled by
610 * the catalog, and are freed separately.
611 */
612 struct event_uniq *pos, *n;
613
614 rbtree_postorder_for_each_entry_safe(pos, n, root, node)
615 kfree(pos);
616 }
617
618
619 /*
620 * ensure the event structure's sizes are self consistent and don't cause us to
621 * read outside of the event
622 *
623 * On success, return the event length in bytes.
624 * Otherwise, return -1 (and print as appropriate).
625 */
catalog_event_len_validate(struct hv_24x7_event_data * event,size_t event_idx,size_t event_data_bytes,size_t event_entry_count,size_t offset,void * end)626 static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
627 size_t event_idx,
628 size_t event_data_bytes,
629 size_t event_entry_count,
630 size_t offset, void *end)
631 {
632 ssize_t ev_len;
633 void *ev_end, *calc_ev_end;
634
635 if (offset >= event_data_bytes)
636 return -1;
637
638 if (event_idx >= event_entry_count) {
639 pr_devel("catalog event data has %zu bytes of padding after last event\n",
640 event_data_bytes - offset);
641 return -1;
642 }
643
644 if (!event_fixed_portion_is_within(event, end)) {
645 pr_warn("event %zu fixed portion is not within range\n",
646 event_idx);
647 return -1;
648 }
649
650 ev_len = be16_to_cpu(event->length);
651
652 if (ev_len % 16)
653 pr_info("event %zu has length %zu not divisible by 16: event=%pK\n",
654 event_idx, ev_len, event);
655
656 ev_end = (__u8 *)event + ev_len;
657 if (ev_end > end) {
658 pr_warn("event %zu has .length=%zu, ends after buffer end: ev_end=%pK > end=%pK, offset=%zu\n",
659 event_idx, ev_len, ev_end, end,
660 offset);
661 return -1;
662 }
663
664 calc_ev_end = event_end(event, end);
665 if (!calc_ev_end) {
666 pr_warn("event %zu has a calculated length which exceeds buffer length %zu: event=%pK end=%pK, offset=%zu\n",
667 event_idx, event_data_bytes, event, end,
668 offset);
669 return -1;
670 }
671
672 if (calc_ev_end > ev_end) {
673 pr_warn("event %zu exceeds it's own length: event=%pK, end=%pK, offset=%zu, calc_ev_end=%pK\n",
674 event_idx, event, ev_end, offset, calc_ev_end);
675 return -1;
676 }
677
678 return ev_len;
679 }
680
681 #define MAX_4K (SIZE_MAX / 4096)
682
create_events_from_catalog(struct attribute *** events_,struct attribute *** event_descs_,struct attribute *** event_long_descs_)683 static int create_events_from_catalog(struct attribute ***events_,
684 struct attribute ***event_descs_,
685 struct attribute ***event_long_descs_)
686 {
687 long hret;
688 size_t catalog_len, catalog_page_len, event_entry_count,
689 event_data_len, event_data_offs,
690 event_data_bytes, junk_events, event_idx, event_attr_ct, i,
691 attr_max, event_idx_last, desc_ct, long_desc_ct;
692 ssize_t ct, ev_len;
693 uint64_t catalog_version_num;
694 struct attribute **events, **event_descs, **event_long_descs;
695 struct hv_24x7_catalog_page_0 *page_0 =
696 kmem_cache_alloc(hv_page_cache, GFP_KERNEL);
697 void *page = page_0;
698 void *event_data, *end;
699 struct hv_24x7_event_data *event;
700 struct rb_root ev_uniq = RB_ROOT;
701 int ret = 0;
702
703 if (!page) {
704 ret = -ENOMEM;
705 goto e_out;
706 }
707
708 hret = h_get_24x7_catalog_page(page, 0, 0);
709 if (hret) {
710 ret = -EIO;
711 goto e_free;
712 }
713
714 catalog_version_num = be64_to_cpu(page_0->version);
715 catalog_page_len = be32_to_cpu(page_0->length);
716
717 if (MAX_4K < catalog_page_len) {
718 pr_err("invalid page count: %zu\n", catalog_page_len);
719 ret = -EIO;
720 goto e_free;
721 }
722
723 catalog_len = catalog_page_len * 4096;
724
725 event_entry_count = be16_to_cpu(page_0->event_entry_count);
726 event_data_offs = be16_to_cpu(page_0->event_data_offs);
727 event_data_len = be16_to_cpu(page_0->event_data_len);
728
729 pr_devel("cv %llu cl %zu eec %zu edo %zu edl %zu\n",
730 catalog_version_num, catalog_len,
731 event_entry_count, event_data_offs, event_data_len);
732
733 if ((MAX_4K < event_data_len)
734 || (MAX_4K < event_data_offs)
735 || (MAX_4K - event_data_offs < event_data_len)) {
736 pr_err("invalid event data offs %zu and/or len %zu\n",
737 event_data_offs, event_data_len);
738 ret = -EIO;
739 goto e_free;
740 }
741
742 if ((event_data_offs + event_data_len) > catalog_page_len) {
743 pr_err("event data %zu-%zu does not fit inside catalog 0-%zu\n",
744 event_data_offs,
745 event_data_offs + event_data_len,
746 catalog_page_len);
747 ret = -EIO;
748 goto e_free;
749 }
750
751 if (SIZE_MAX - 1 < event_entry_count) {
752 pr_err("event_entry_count %zu is invalid\n", event_entry_count);
753 ret = -EIO;
754 goto e_free;
755 }
756
757 event_data_bytes = event_data_len * 4096;
758
759 /*
760 * event data can span several pages, events can cross between these
761 * pages. Use vmalloc to make this easier.
762 */
763 event_data = vmalloc(event_data_bytes);
764 if (!event_data) {
765 pr_err("could not allocate event data\n");
766 ret = -ENOMEM;
767 goto e_free;
768 }
769
770 end = event_data + event_data_bytes;
771
772 /*
773 * using vmalloc_to_phys() like this only works if PAGE_SIZE is
774 * divisible by 4096
775 */
776 BUILD_BUG_ON(PAGE_SIZE % 4096);
777
778 for (i = 0; i < event_data_len; i++) {
779 hret = h_get_24x7_catalog_page_(
780 vmalloc_to_phys(event_data + i * 4096),
781 catalog_version_num,
782 i + event_data_offs);
783 if (hret) {
784 pr_err("Failed to get event data in page %zu: rc=%ld\n",
785 i + event_data_offs, hret);
786 ret = -EIO;
787 goto e_event_data;
788 }
789 }
790
791 /*
792 * scan the catalog to determine the number of attributes we need, and
793 * verify it at the same time.
794 */
795 for (junk_events = 0, event = event_data, event_idx = 0, attr_max = 0;
796 ;
797 event_idx++, event = (void *)event + ev_len) {
798 size_t offset = (void *)event - (void *)event_data;
799 char *name;
800 int nl;
801
802 ev_len = catalog_event_len_validate(event, event_idx,
803 event_data_bytes,
804 event_entry_count,
805 offset, end);
806 if (ev_len < 0)
807 break;
808
809 name = event_name(event, &nl);
810
811 if (event->event_group_record_len == 0) {
812 pr_devel("invalid event %zu (%.*s): group_record_len == 0, skipping\n",
813 event_idx, nl, name);
814 junk_events++;
815 continue;
816 }
817
818 if (!catalog_entry_domain_is_valid(event->domain)) {
819 pr_info("event %zu (%.*s) has invalid domain %d\n",
820 event_idx, nl, name, event->domain);
821 junk_events++;
822 continue;
823 }
824
825 attr_max++;
826 }
827
828 event_idx_last = event_idx;
829 if (event_idx_last != event_entry_count)
830 pr_warn("event buffer ended before listed # of events were parsed (got %zu, wanted %zu, junk %zu)\n",
831 event_idx_last, event_entry_count, junk_events);
832
833 events = kmalloc_array(attr_max + 1, sizeof(*events), GFP_KERNEL);
834 if (!events) {
835 ret = -ENOMEM;
836 goto e_event_data;
837 }
838
839 event_descs = kmalloc_array(event_idx + 1, sizeof(*event_descs),
840 GFP_KERNEL);
841 if (!event_descs) {
842 ret = -ENOMEM;
843 goto e_event_attrs;
844 }
845
846 event_long_descs = kmalloc_array(event_idx + 1,
847 sizeof(*event_long_descs), GFP_KERNEL);
848 if (!event_long_descs) {
849 ret = -ENOMEM;
850 goto e_event_descs;
851 }
852
853 /* Iterate over the catalog filling in the attribute vector */
854 for (junk_events = 0, event_attr_ct = 0, desc_ct = 0, long_desc_ct = 0,
855 event = event_data, event_idx = 0;
856 event_idx < event_idx_last;
857 event_idx++, ev_len = be16_to_cpu(event->length),
858 event = (void *)event + ev_len) {
859 char *name;
860 int nl;
861 int nonce;
862 /*
863 * these are the only "bad" events that are intermixed and that
864 * we can ignore without issue. make sure to skip them here
865 */
866 if (event->event_group_record_len == 0)
867 continue;
868 if (!catalog_entry_domain_is_valid(event->domain))
869 continue;
870
871 name = event_name(event, &nl);
872 nonce = event_uniq_add(&ev_uniq, name, nl, event->domain);
873 ct = event_data_to_attrs(event_idx, events + event_attr_ct,
874 event, nonce);
875 if (ct < 0) {
876 pr_warn("event %zu (%.*s) creation failure, skipping\n",
877 event_idx, nl, name);
878 junk_events++;
879 } else {
880 event_attr_ct++;
881 event_descs[desc_ct] = event_to_desc_attr(event, nonce);
882 if (event_descs[desc_ct])
883 desc_ct++;
884 event_long_descs[long_desc_ct] =
885 event_to_long_desc_attr(event, nonce);
886 if (event_long_descs[long_desc_ct])
887 long_desc_ct++;
888 }
889 }
890
891 pr_info("read %zu catalog entries, created %zu event attrs (%zu failures), %zu descs\n",
892 event_idx, event_attr_ct, junk_events, desc_ct);
893
894 events[event_attr_ct] = NULL;
895 event_descs[desc_ct] = NULL;
896 event_long_descs[long_desc_ct] = NULL;
897
898 event_uniq_destroy(&ev_uniq);
899 vfree(event_data);
900 kmem_cache_free(hv_page_cache, page);
901
902 *events_ = events;
903 *event_descs_ = event_descs;
904 *event_long_descs_ = event_long_descs;
905 return 0;
906
907 e_event_descs:
908 kfree(event_descs);
909 e_event_attrs:
910 kfree(events);
911 e_event_data:
912 vfree(event_data);
913 e_free:
914 kmem_cache_free(hv_page_cache, page);
915 e_out:
916 *events_ = NULL;
917 *event_descs_ = NULL;
918 *event_long_descs_ = NULL;
919 return ret;
920 }
921
catalog_read(struct file * filp,struct kobject * kobj,struct bin_attribute * bin_attr,char * buf,loff_t offset,size_t count)922 static ssize_t catalog_read(struct file *filp, struct kobject *kobj,
923 struct bin_attribute *bin_attr, char *buf,
924 loff_t offset, size_t count)
925 {
926 long hret;
927 ssize_t ret = 0;
928 size_t catalog_len = 0, catalog_page_len = 0;
929 loff_t page_offset = 0;
930 loff_t offset_in_page;
931 size_t copy_len;
932 uint64_t catalog_version_num = 0;
933 void *page = kmem_cache_alloc(hv_page_cache, GFP_USER);
934 struct hv_24x7_catalog_page_0 *page_0 = page;
935
936 if (!page)
937 return -ENOMEM;
938
939 hret = h_get_24x7_catalog_page(page, 0, 0);
940 if (hret) {
941 ret = -EIO;
942 goto e_free;
943 }
944
945 catalog_version_num = be64_to_cpu(page_0->version);
946 catalog_page_len = be32_to_cpu(page_0->length);
947 catalog_len = catalog_page_len * 4096;
948
949 page_offset = offset / 4096;
950 offset_in_page = offset % 4096;
951
952 if (page_offset >= catalog_page_len)
953 goto e_free;
954
955 if (page_offset != 0) {
956 hret = h_get_24x7_catalog_page(page, catalog_version_num,
957 page_offset);
958 if (hret) {
959 ret = -EIO;
960 goto e_free;
961 }
962 }
963
964 copy_len = 4096 - offset_in_page;
965 if (copy_len > count)
966 copy_len = count;
967
968 memcpy(buf, page+offset_in_page, copy_len);
969 ret = copy_len;
970
971 e_free:
972 if (hret)
973 pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:"
974 " rc=%ld\n",
975 catalog_version_num, page_offset, hret);
976 kmem_cache_free(hv_page_cache, page);
977
978 pr_devel("catalog_read: offset=%lld(%lld) count=%zu "
979 "catalog_len=%zu(%zu) => %zd\n", offset, page_offset,
980 count, catalog_len, catalog_page_len, ret);
981
982 return ret;
983 }
984
domains_show(struct device * dev,struct device_attribute * attr,char * page)985 static ssize_t domains_show(struct device *dev, struct device_attribute *attr,
986 char *page)
987 {
988 int d, n, count = 0;
989 const char *str;
990
991 for (d = 0; d < HV_PERF_DOMAIN_MAX; d++) {
992 str = domain_name(d);
993 if (!str)
994 continue;
995
996 n = sprintf(page, "%d: %s\n", d, str);
997 if (n < 0)
998 break;
999
1000 count += n;
1001 page += n;
1002 }
1003 return count;
1004 }
1005
1006 #define PAGE_0_ATTR(_name, _fmt, _expr) \
1007 static ssize_t _name##_show(struct device *dev, \
1008 struct device_attribute *dev_attr, \
1009 char *buf) \
1010 { \
1011 long hret; \
1012 ssize_t ret = 0; \
1013 void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \
1014 struct hv_24x7_catalog_page_0 *page_0 = page; \
1015 if (!page) \
1016 return -ENOMEM; \
1017 hret = h_get_24x7_catalog_page(page, 0, 0); \
1018 if (hret) { \
1019 ret = -EIO; \
1020 goto e_free; \
1021 } \
1022 ret = sprintf(buf, _fmt, _expr); \
1023 e_free: \
1024 kmem_cache_free(hv_page_cache, page); \
1025 return ret; \
1026 } \
1027 static DEVICE_ATTR_RO(_name)
1028
1029 PAGE_0_ATTR(catalog_version, "%lld\n",
1030 (unsigned long long)be64_to_cpu(page_0->version));
1031 PAGE_0_ATTR(catalog_len, "%lld\n",
1032 (unsigned long long)be32_to_cpu(page_0->length) * 4096);
1033 static BIN_ATTR_RO(catalog, 0/* real length varies */);
1034 static DEVICE_ATTR_RO(domains);
1035
1036 static struct bin_attribute *if_bin_attrs[] = {
1037 &bin_attr_catalog,
1038 NULL,
1039 };
1040
1041 static struct attribute *if_attrs[] = {
1042 &dev_attr_catalog_len.attr,
1043 &dev_attr_catalog_version.attr,
1044 &dev_attr_domains.attr,
1045 NULL,
1046 };
1047
1048 static struct attribute_group if_group = {
1049 .name = "interface",
1050 .bin_attrs = if_bin_attrs,
1051 .attrs = if_attrs,
1052 };
1053
1054 static const struct attribute_group *attr_groups[] = {
1055 &format_group,
1056 &event_group,
1057 &event_desc_group,
1058 &event_long_desc_group,
1059 &if_group,
1060 NULL,
1061 };
1062
1063 /*
1064 * Start the process for a new H_GET_24x7_DATA hcall.
1065 */
init_24x7_request(struct hv_24x7_request_buffer * request_buffer,struct hv_24x7_data_result_buffer * result_buffer)1066 static void init_24x7_request(struct hv_24x7_request_buffer *request_buffer,
1067 struct hv_24x7_data_result_buffer *result_buffer)
1068 {
1069
1070 memset(request_buffer, 0, H24x7_DATA_BUFFER_SIZE);
1071 memset(result_buffer, 0, H24x7_DATA_BUFFER_SIZE);
1072
1073 request_buffer->interface_version = interface_version;
1074 /* memset above set request_buffer->num_requests to 0 */
1075 }
1076
1077 /*
1078 * Commit (i.e perform) the H_GET_24x7_DATA hcall using the data collected
1079 * by 'init_24x7_request()' and 'add_event_to_24x7_request()'.
1080 */
make_24x7_request(struct hv_24x7_request_buffer * request_buffer,struct hv_24x7_data_result_buffer * result_buffer)1081 static int make_24x7_request(struct hv_24x7_request_buffer *request_buffer,
1082 struct hv_24x7_data_result_buffer *result_buffer)
1083 {
1084 long ret;
1085
1086 /*
1087 * NOTE: Due to variable number of array elements in request and
1088 * result buffer(s), sizeof() is not reliable. Use the actual
1089 * allocated buffer size, H24x7_DATA_BUFFER_SIZE.
1090 */
1091 ret = plpar_hcall_norets(H_GET_24X7_DATA,
1092 virt_to_phys(request_buffer), H24x7_DATA_BUFFER_SIZE,
1093 virt_to_phys(result_buffer), H24x7_DATA_BUFFER_SIZE);
1094
1095 if (ret) {
1096 struct hv_24x7_request *req;
1097
1098 req = request_buffer->requests;
1099 pr_notice_ratelimited("hcall failed: [%d %#x %#x %d] => ret 0x%lx (%ld) detail=0x%x failing ix=%x\n",
1100 req->performance_domain, req->data_offset,
1101 req->starting_ix, req->starting_lpar_ix,
1102 ret, ret, result_buffer->detailed_rc,
1103 result_buffer->failing_request_ix);
1104 return -EIO;
1105 }
1106
1107 return 0;
1108 }
1109
1110 /*
1111 * Add the given @event to the next slot in the 24x7 request_buffer.
1112 *
1113 * Note that H_GET_24X7_DATA hcall allows reading several counters'
1114 * values in a single HCALL. We expect the caller to add events to the
1115 * request buffer one by one, make the HCALL and process the results.
1116 */
add_event_to_24x7_request(struct perf_event * event,struct hv_24x7_request_buffer * request_buffer)1117 static int add_event_to_24x7_request(struct perf_event *event,
1118 struct hv_24x7_request_buffer *request_buffer)
1119 {
1120 u16 idx;
1121 int i;
1122 size_t req_size;
1123 struct hv_24x7_request *req;
1124
1125 if (request_buffer->num_requests >=
1126 max_num_requests(request_buffer->interface_version)) {
1127 pr_devel("Too many requests for 24x7 HCALL %d\n",
1128 request_buffer->num_requests);
1129 return -EINVAL;
1130 }
1131
1132 switch (event_get_domain(event)) {
1133 case HV_PERF_DOMAIN_PHYS_CHIP:
1134 idx = event_get_chip(event);
1135 break;
1136 case HV_PERF_DOMAIN_PHYS_CORE:
1137 idx = event_get_core(event);
1138 break;
1139 default:
1140 idx = event_get_vcpu(event);
1141 }
1142
1143 req_size = H24x7_REQUEST_SIZE(request_buffer->interface_version);
1144
1145 i = request_buffer->num_requests++;
1146 req = (void *) request_buffer->requests + i * req_size;
1147
1148 req->performance_domain = event_get_domain(event);
1149 req->data_size = cpu_to_be16(8);
1150 req->data_offset = cpu_to_be32(event_get_offset(event));
1151 req->starting_lpar_ix = cpu_to_be16(event_get_lpar(event));
1152 req->max_num_lpars = cpu_to_be16(1);
1153 req->starting_ix = cpu_to_be16(idx);
1154 req->max_ix = cpu_to_be16(1);
1155
1156 if (request_buffer->interface_version > 1) {
1157 if (domain_needs_aggregation(req->performance_domain))
1158 req->max_num_thread_groups = -1;
1159 else if (req->performance_domain != HV_PERF_DOMAIN_PHYS_CHIP) {
1160 req->starting_thread_group_ix = idx % 2;
1161 req->max_num_thread_groups = 1;
1162 }
1163 }
1164
1165 return 0;
1166 }
1167
1168 /**
1169 * get_count_from_result - get event count from all result elements in result
1170 *
1171 * If the event corresponding to this result needs aggregation of the result
1172 * element values, then this function does that.
1173 *
1174 * @event: Event associated with @res.
1175 * @resb: Result buffer containing @res.
1176 * @res: Result to work on.
1177 * @countp: Output variable containing the event count.
1178 * @next: Optional output variable pointing to the next result in @resb.
1179 */
get_count_from_result(struct perf_event * event,struct hv_24x7_data_result_buffer * resb,struct hv_24x7_result * res,u64 * countp,struct hv_24x7_result ** next)1180 static int get_count_from_result(struct perf_event *event,
1181 struct hv_24x7_data_result_buffer *resb,
1182 struct hv_24x7_result *res, u64 *countp,
1183 struct hv_24x7_result **next)
1184 {
1185 u16 num_elements = be16_to_cpu(res->num_elements_returned);
1186 u16 data_size = be16_to_cpu(res->result_element_data_size);
1187 unsigned int data_offset;
1188 void *element_data;
1189 int i;
1190 u64 count;
1191
1192 /*
1193 * We can bail out early if the result is empty.
1194 */
1195 if (!num_elements) {
1196 pr_debug("Result of request %hhu is empty, nothing to do\n",
1197 res->result_ix);
1198
1199 if (next)
1200 *next = (struct hv_24x7_result *) res->elements;
1201
1202 return -ENODATA;
1203 }
1204
1205 /*
1206 * Since we always specify 1 as the maximum for the smallest resource
1207 * we're requesting, there should to be only one element per result.
1208 * Except when an event needs aggregation, in which case there are more.
1209 */
1210 if (num_elements != 1 &&
1211 !domain_needs_aggregation(event_get_domain(event))) {
1212 pr_err("Error: result of request %hhu has %hu elements\n",
1213 res->result_ix, num_elements);
1214
1215 return -EIO;
1216 }
1217
1218 if (data_size != sizeof(u64)) {
1219 pr_debug("Error: result of request %hhu has data of %hu bytes\n",
1220 res->result_ix, data_size);
1221
1222 return -ENOTSUPP;
1223 }
1224
1225 if (resb->interface_version == 1)
1226 data_offset = offsetof(struct hv_24x7_result_element_v1,
1227 element_data);
1228 else
1229 data_offset = offsetof(struct hv_24x7_result_element_v2,
1230 element_data);
1231
1232 /* Go through the result elements in the result. */
1233 for (i = count = 0, element_data = res->elements + data_offset;
1234 i < num_elements;
1235 i++, element_data += data_size + data_offset)
1236 count += be64_to_cpu(*((u64 *) element_data));
1237
1238 *countp = count;
1239
1240 /* The next result is after the last result element. */
1241 if (next)
1242 *next = element_data - data_offset;
1243
1244 return 0;
1245 }
1246
single_24x7_request(struct perf_event * event,u64 * count)1247 static int single_24x7_request(struct perf_event *event, u64 *count)
1248 {
1249 int ret;
1250 struct hv_24x7_request_buffer *request_buffer;
1251 struct hv_24x7_data_result_buffer *result_buffer;
1252
1253 BUILD_BUG_ON(sizeof(*request_buffer) > 4096);
1254 BUILD_BUG_ON(sizeof(*result_buffer) > 4096);
1255
1256 request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1257 result_buffer = (void *)get_cpu_var(hv_24x7_resb);
1258
1259 init_24x7_request(request_buffer, result_buffer);
1260
1261 ret = add_event_to_24x7_request(event, request_buffer);
1262 if (ret)
1263 goto out;
1264
1265 ret = make_24x7_request(request_buffer, result_buffer);
1266 if (ret)
1267 goto out;
1268
1269 /* process result from hcall */
1270 ret = get_count_from_result(event, result_buffer,
1271 result_buffer->results, count, NULL);
1272
1273 out:
1274 put_cpu_var(hv_24x7_reqb);
1275 put_cpu_var(hv_24x7_resb);
1276 return ret;
1277 }
1278
1279
h_24x7_event_init(struct perf_event * event)1280 static int h_24x7_event_init(struct perf_event *event)
1281 {
1282 struct hv_perf_caps caps;
1283 unsigned domain;
1284 unsigned long hret;
1285 u64 ct;
1286
1287 /* Not our event */
1288 if (event->attr.type != event->pmu->type)
1289 return -ENOENT;
1290
1291 /* Unused areas must be 0 */
1292 if (event_get_reserved1(event) ||
1293 event_get_reserved2(event) ||
1294 event_get_reserved3(event)) {
1295 pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n",
1296 event->attr.config,
1297 event_get_reserved1(event),
1298 event->attr.config1,
1299 event_get_reserved2(event),
1300 event->attr.config2,
1301 event_get_reserved3(event));
1302 return -EINVAL;
1303 }
1304
1305 /* no branch sampling */
1306 if (has_branch_stack(event))
1307 return -EOPNOTSUPP;
1308
1309 /* offset must be 8 byte aligned */
1310 if (event_get_offset(event) % 8) {
1311 pr_devel("bad alignment\n");
1312 return -EINVAL;
1313 }
1314
1315 domain = event_get_domain(event);
1316 if (domain >= HV_PERF_DOMAIN_MAX) {
1317 pr_devel("invalid domain %d\n", domain);
1318 return -EINVAL;
1319 }
1320
1321 hret = hv_perf_caps_get(&caps);
1322 if (hret) {
1323 pr_devel("could not get capabilities: rc=%ld\n", hret);
1324 return -EIO;
1325 }
1326
1327 /* Physical domains & other lpars require extra capabilities */
1328 if (!caps.collect_privileged && (is_physical_domain(domain) ||
1329 (event_get_lpar(event) != event_get_lpar_max()))) {
1330 pr_devel("hv permissions disallow: is_physical_domain:%d, lpar=0x%llx\n",
1331 is_physical_domain(domain),
1332 event_get_lpar(event));
1333 return -EACCES;
1334 }
1335
1336 /* Get the initial value of the counter for this event */
1337 if (single_24x7_request(event, &ct)) {
1338 pr_devel("test hcall failed\n");
1339 return -EIO;
1340 }
1341 (void)local64_xchg(&event->hw.prev_count, ct);
1342
1343 return 0;
1344 }
1345
h_24x7_get_value(struct perf_event * event)1346 static u64 h_24x7_get_value(struct perf_event *event)
1347 {
1348 u64 ct;
1349
1350 if (single_24x7_request(event, &ct))
1351 /* We checked this in event init, shouldn't fail here... */
1352 return 0;
1353
1354 return ct;
1355 }
1356
update_event_count(struct perf_event * event,u64 now)1357 static void update_event_count(struct perf_event *event, u64 now)
1358 {
1359 s64 prev;
1360
1361 prev = local64_xchg(&event->hw.prev_count, now);
1362 local64_add(now - prev, &event->count);
1363 }
1364
h_24x7_event_read(struct perf_event * event)1365 static void h_24x7_event_read(struct perf_event *event)
1366 {
1367 u64 now;
1368 struct hv_24x7_request_buffer *request_buffer;
1369 struct hv_24x7_hw *h24x7hw;
1370 int txn_flags;
1371
1372 txn_flags = __this_cpu_read(hv_24x7_txn_flags);
1373
1374 /*
1375 * If in a READ transaction, add this counter to the list of
1376 * counters to read during the next HCALL (i.e commit_txn()).
1377 * If not in a READ transaction, go ahead and make the HCALL
1378 * to read this counter by itself.
1379 */
1380
1381 if (txn_flags & PERF_PMU_TXN_READ) {
1382 int i;
1383 int ret;
1384
1385 if (__this_cpu_read(hv_24x7_txn_err))
1386 return;
1387
1388 request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1389
1390 ret = add_event_to_24x7_request(event, request_buffer);
1391 if (ret) {
1392 __this_cpu_write(hv_24x7_txn_err, ret);
1393 } else {
1394 /*
1395 * Associate the event with the HCALL request index,
1396 * so ->commit_txn() can quickly find/update count.
1397 */
1398 i = request_buffer->num_requests - 1;
1399
1400 h24x7hw = &get_cpu_var(hv_24x7_hw);
1401 h24x7hw->events[i] = event;
1402 put_cpu_var(h24x7hw);
1403 /*
1404 * Clear the event count so we can compute the _change_
1405 * in the 24x7 raw counter value at the end of the txn.
1406 *
1407 * Note that we could alternatively read the 24x7 value
1408 * now and save its value in event->hw.prev_count. But
1409 * that would require issuing a hcall, which would then
1410 * defeat the purpose of using the txn interface.
1411 */
1412 local64_set(&event->count, 0);
1413 }
1414
1415 put_cpu_var(hv_24x7_reqb);
1416 } else {
1417 now = h_24x7_get_value(event);
1418 update_event_count(event, now);
1419 }
1420 }
1421
h_24x7_event_start(struct perf_event * event,int flags)1422 static void h_24x7_event_start(struct perf_event *event, int flags)
1423 {
1424 if (flags & PERF_EF_RELOAD)
1425 local64_set(&event->hw.prev_count, h_24x7_get_value(event));
1426 }
1427
h_24x7_event_stop(struct perf_event * event,int flags)1428 static void h_24x7_event_stop(struct perf_event *event, int flags)
1429 {
1430 h_24x7_event_read(event);
1431 }
1432
h_24x7_event_add(struct perf_event * event,int flags)1433 static int h_24x7_event_add(struct perf_event *event, int flags)
1434 {
1435 if (flags & PERF_EF_START)
1436 h_24x7_event_start(event, flags);
1437
1438 return 0;
1439 }
1440
1441 /*
1442 * 24x7 counters only support READ transactions. They are
1443 * always counting and dont need/support ADD transactions.
1444 * Cache the flags, but otherwise ignore transactions that
1445 * are not PERF_PMU_TXN_READ.
1446 */
h_24x7_event_start_txn(struct pmu * pmu,unsigned int flags)1447 static void h_24x7_event_start_txn(struct pmu *pmu, unsigned int flags)
1448 {
1449 struct hv_24x7_request_buffer *request_buffer;
1450 struct hv_24x7_data_result_buffer *result_buffer;
1451
1452 /* We should not be called if we are already in a txn */
1453 WARN_ON_ONCE(__this_cpu_read(hv_24x7_txn_flags));
1454
1455 __this_cpu_write(hv_24x7_txn_flags, flags);
1456 if (flags & ~PERF_PMU_TXN_READ)
1457 return;
1458
1459 request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1460 result_buffer = (void *)get_cpu_var(hv_24x7_resb);
1461
1462 init_24x7_request(request_buffer, result_buffer);
1463
1464 put_cpu_var(hv_24x7_resb);
1465 put_cpu_var(hv_24x7_reqb);
1466 }
1467
1468 /*
1469 * Clean up transaction state.
1470 *
1471 * NOTE: Ignore state of request and result buffers for now.
1472 * We will initialize them during the next read/txn.
1473 */
reset_txn(void)1474 static void reset_txn(void)
1475 {
1476 __this_cpu_write(hv_24x7_txn_flags, 0);
1477 __this_cpu_write(hv_24x7_txn_err, 0);
1478 }
1479
1480 /*
1481 * 24x7 counters only support READ transactions. They are always counting
1482 * and dont need/support ADD transactions. Clear ->txn_flags but otherwise
1483 * ignore transactions that are not of type PERF_PMU_TXN_READ.
1484 *
1485 * For READ transactions, submit all pending 24x7 requests (i.e requests
1486 * that were queued by h_24x7_event_read()), to the hypervisor and update
1487 * the event counts.
1488 */
h_24x7_event_commit_txn(struct pmu * pmu)1489 static int h_24x7_event_commit_txn(struct pmu *pmu)
1490 {
1491 struct hv_24x7_request_buffer *request_buffer;
1492 struct hv_24x7_data_result_buffer *result_buffer;
1493 struct hv_24x7_result *res, *next_res;
1494 u64 count;
1495 int i, ret, txn_flags;
1496 struct hv_24x7_hw *h24x7hw;
1497
1498 txn_flags = __this_cpu_read(hv_24x7_txn_flags);
1499 WARN_ON_ONCE(!txn_flags);
1500
1501 ret = 0;
1502 if (txn_flags & ~PERF_PMU_TXN_READ)
1503 goto out;
1504
1505 ret = __this_cpu_read(hv_24x7_txn_err);
1506 if (ret)
1507 goto out;
1508
1509 request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1510 result_buffer = (void *)get_cpu_var(hv_24x7_resb);
1511
1512 ret = make_24x7_request(request_buffer, result_buffer);
1513 if (ret)
1514 goto put_reqb;
1515
1516 h24x7hw = &get_cpu_var(hv_24x7_hw);
1517
1518 /* Go through results in the result buffer to update event counts. */
1519 for (i = 0, res = result_buffer->results;
1520 i < result_buffer->num_results; i++, res = next_res) {
1521 struct perf_event *event = h24x7hw->events[res->result_ix];
1522
1523 ret = get_count_from_result(event, result_buffer, res, &count,
1524 &next_res);
1525 if (ret)
1526 break;
1527
1528 update_event_count(event, count);
1529 }
1530
1531 put_cpu_var(hv_24x7_hw);
1532
1533 put_reqb:
1534 put_cpu_var(hv_24x7_resb);
1535 put_cpu_var(hv_24x7_reqb);
1536 out:
1537 reset_txn();
1538 return ret;
1539 }
1540
1541 /*
1542 * 24x7 counters only support READ transactions. They are always counting
1543 * and dont need/support ADD transactions. However, regardless of type
1544 * of transaction, all we need to do is cleanup, so we don't have to check
1545 * the type of transaction.
1546 */
h_24x7_event_cancel_txn(struct pmu * pmu)1547 static void h_24x7_event_cancel_txn(struct pmu *pmu)
1548 {
1549 WARN_ON_ONCE(!__this_cpu_read(hv_24x7_txn_flags));
1550 reset_txn();
1551 }
1552
1553 static struct pmu h_24x7_pmu = {
1554 .task_ctx_nr = perf_invalid_context,
1555
1556 .name = "hv_24x7",
1557 .attr_groups = attr_groups,
1558 .event_init = h_24x7_event_init,
1559 .add = h_24x7_event_add,
1560 .del = h_24x7_event_stop,
1561 .start = h_24x7_event_start,
1562 .stop = h_24x7_event_stop,
1563 .read = h_24x7_event_read,
1564 .start_txn = h_24x7_event_start_txn,
1565 .commit_txn = h_24x7_event_commit_txn,
1566 .cancel_txn = h_24x7_event_cancel_txn,
1567 .capabilities = PERF_PMU_CAP_NO_EXCLUDE,
1568 };
1569
hv_24x7_init(void)1570 static int hv_24x7_init(void)
1571 {
1572 int r;
1573 unsigned long hret;
1574 struct hv_perf_caps caps;
1575
1576 if (!firmware_has_feature(FW_FEATURE_LPAR)) {
1577 pr_debug("not a virtualized system, not enabling\n");
1578 return -ENODEV;
1579 } else if (!cur_cpu_spec->oprofile_cpu_type)
1580 return -ENODEV;
1581
1582 /* POWER8 only supports v1, while POWER9 only supports v2. */
1583 if (!strcmp(cur_cpu_spec->oprofile_cpu_type, "ppc64/power8"))
1584 interface_version = 1;
1585 else {
1586 interface_version = 2;
1587
1588 /* SMT8 in POWER9 needs to aggregate result elements. */
1589 if (threads_per_core == 8)
1590 aggregate_result_elements = true;
1591 }
1592
1593 hret = hv_perf_caps_get(&caps);
1594 if (hret) {
1595 pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
1596 hret);
1597 return -ENODEV;
1598 }
1599
1600 hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL);
1601 if (!hv_page_cache)
1602 return -ENOMEM;
1603
1604 /* sampling not supported */
1605 h_24x7_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1606
1607 r = create_events_from_catalog(&event_group.attrs,
1608 &event_desc_group.attrs,
1609 &event_long_desc_group.attrs);
1610
1611 if (r)
1612 return r;
1613
1614 r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
1615 if (r)
1616 return r;
1617
1618 return 0;
1619 }
1620
1621 device_initcall(hv_24x7_init);
1622