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TOMOYO Linux Cross Reference
Linux/arch/powerpc/perf/hv-24x7.c

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  1 /*
  2  * Hypervisor supplied "24x7" performance counter support
  3  *
  4  * Author: Cody P Schafer <cody@linux.vnet.ibm.com>
  5  * Copyright 2014 IBM Corporation.
  6  *
  7  * This program is free software; you can redistribute it and/or
  8  * modify it under the terms of the GNU General Public License
  9  * as published by the Free Software Foundation; either version
 10  * 2 of the License, or (at your option) any later version.
 11  */
 12 
 13 #define pr_fmt(fmt) "hv-24x7: " fmt
 14 
 15 #include <linux/perf_event.h>
 16 #include <linux/rbtree.h>
 17 #include <linux/module.h>
 18 #include <linux/slab.h>
 19 #include <linux/vmalloc.h>
 20 
 21 #include <asm/firmware.h>
 22 #include <asm/hvcall.h>
 23 #include <asm/io.h>
 24 #include <linux/byteorder/generic.h>
 25 
 26 #include "hv-24x7.h"
 27 #include "hv-24x7-catalog.h"
 28 #include "hv-common.h"
 29 
 30 static const char *event_domain_suffix(unsigned domain)
 31 {
 32         switch (domain) {
 33 #define DOMAIN(n, v, x, c)              \
 34         case HV_PERF_DOMAIN_##n:        \
 35                 return "__" #n;
 36 #include "hv-24x7-domains.h"
 37 #undef DOMAIN
 38         default:
 39                 WARN(1, "unknown domain %d\n", domain);
 40                 return "__UNKNOWN_DOMAIN_SUFFIX";
 41         }
 42 }
 43 
 44 static bool domain_is_valid(unsigned domain)
 45 {
 46         switch (domain) {
 47 #define DOMAIN(n, v, x, c)              \
 48         case HV_PERF_DOMAIN_##n:        \
 49                 /* fall through */
 50 #include "hv-24x7-domains.h"
 51 #undef DOMAIN
 52                 return true;
 53         default:
 54                 return false;
 55         }
 56 }
 57 
 58 static bool is_physical_domain(unsigned domain)
 59 {
 60         switch (domain) {
 61 #define DOMAIN(n, v, x, c)              \
 62         case HV_PERF_DOMAIN_##n:        \
 63                 return c;
 64 #include "hv-24x7-domains.h"
 65 #undef DOMAIN
 66         default:
 67                 return false;
 68         }
 69 }
 70 
 71 static bool catalog_entry_domain_is_valid(unsigned domain)
 72 {
 73         return is_physical_domain(domain);
 74 }
 75 
 76 /*
 77  * TODO: Merging events:
 78  * - Think of the hcall as an interface to a 4d array of counters:
 79  *   - x = domains
 80  *   - y = indexes in the domain (core, chip, vcpu, node, etc)
 81  *   - z = offset into the counter space
 82  *   - w = lpars (guest vms, "logical partitions")
 83  * - A single request is: x,y,y_last,z,z_last,w,w_last
 84  *   - this means we can retrieve a rectangle of counters in y,z for a single x.
 85  *
 86  * - Things to consider (ignoring w):
 87  *   - input  cost_per_request = 16
 88  *   - output cost_per_result(ys,zs)  = 8 + 8 * ys + ys * zs
 89  *   - limited number of requests per hcall (must fit into 4K bytes)
 90  *     - 4k = 16 [buffer header] - 16 [request size] * request_count
 91  *     - 255 requests per hcall
 92  *   - sometimes it will be more efficient to read extra data and discard
 93  */
 94 
 95 /*
 96  * Example usage:
 97  *  perf stat -e 'hv_24x7/domain=2,offset=8,vcpu=0,lpar=0xffffffff/'
 98  */
 99 
100 /* u3 0-6, one of HV_24X7_PERF_DOMAIN */
101 EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3);
102 /* u16 */
103 EVENT_DEFINE_RANGE_FORMAT(core, config, 16, 31);
104 EVENT_DEFINE_RANGE_FORMAT(vcpu, config, 16, 31);
105 /* u32, see "data_offset" */
106 EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63);
107 /* u16 */
108 EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15);
109 
110 EVENT_DEFINE_RANGE(reserved1, config,   4, 15);
111 EVENT_DEFINE_RANGE(reserved2, config1, 16, 63);
112 EVENT_DEFINE_RANGE(reserved3, config2,  0, 63);
113 
114 static struct attribute *format_attrs[] = {
115         &format_attr_domain.attr,
116         &format_attr_offset.attr,
117         &format_attr_core.attr,
118         &format_attr_vcpu.attr,
119         &format_attr_lpar.attr,
120         NULL,
121 };
122 
123 static struct attribute_group format_group = {
124         .name = "format",
125         .attrs = format_attrs,
126 };
127 
128 static struct attribute_group event_group = {
129         .name = "events",
130         /* .attrs is set in init */
131 };
132 
133 static struct attribute_group event_desc_group = {
134         .name = "event_descs",
135         /* .attrs is set in init */
136 };
137 
138 static struct attribute_group event_long_desc_group = {
139         .name = "event_long_descs",
140         /* .attrs is set in init */
141 };
142 
143 static struct kmem_cache *hv_page_cache;
144 
145 /*
146  * request_buffer and result_buffer are not required to be 4k aligned,
147  * but are not allowed to cross any 4k boundary. Aligning them to 4k is
148  * the simplest way to ensure that.
149  */
150 #define H24x7_DATA_BUFFER_SIZE  4096
151 DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
152 DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
153 
154 static char *event_name(struct hv_24x7_event_data *ev, int *len)
155 {
156         *len = be16_to_cpu(ev->event_name_len) - 2;
157         return (char *)ev->remainder;
158 }
159 
160 static char *event_desc(struct hv_24x7_event_data *ev, int *len)
161 {
162         unsigned nl = be16_to_cpu(ev->event_name_len);
163         __be16 *desc_len = (__be16 *)(ev->remainder + nl - 2);
164 
165         *len = be16_to_cpu(*desc_len) - 2;
166         return (char *)ev->remainder + nl;
167 }
168 
169 static char *event_long_desc(struct hv_24x7_event_data *ev, int *len)
170 {
171         unsigned nl = be16_to_cpu(ev->event_name_len);
172         __be16 *desc_len_ = (__be16 *)(ev->remainder + nl - 2);
173         unsigned desc_len = be16_to_cpu(*desc_len_);
174         __be16 *long_desc_len = (__be16 *)(ev->remainder + nl + desc_len - 2);
175 
176         *len = be16_to_cpu(*long_desc_len) - 2;
177         return (char *)ev->remainder + nl + desc_len;
178 }
179 
180 static bool event_fixed_portion_is_within(struct hv_24x7_event_data *ev,
181                                           void *end)
182 {
183         void *start = ev;
184 
185         return (start + offsetof(struct hv_24x7_event_data, remainder)) < end;
186 }
187 
188 /*
189  * Things we don't check:
190  *  - padding for desc, name, and long/detailed desc is required to be '\0'
191  *    bytes.
192  *
193  *  Return NULL if we pass end,
194  *  Otherwise return the address of the byte just following the event.
195  */
196 static void *event_end(struct hv_24x7_event_data *ev, void *end)
197 {
198         void *start = ev;
199         __be16 *dl_, *ldl_;
200         unsigned dl, ldl;
201         unsigned nl = be16_to_cpu(ev->event_name_len);
202 
203         if (nl < 2) {
204                 pr_debug("%s: name length too short: %d", __func__, nl);
205                 return NULL;
206         }
207 
208         if (start + nl > end) {
209                 pr_debug("%s: start=%p + nl=%u > end=%p",
210                                 __func__, start, nl, end);
211                 return NULL;
212         }
213 
214         dl_ = (__be16 *)(ev->remainder + nl - 2);
215         if (!IS_ALIGNED((uintptr_t)dl_, 2))
216                 pr_warn("desc len not aligned %p", dl_);
217         dl = be16_to_cpu(*dl_);
218         if (dl < 2) {
219                 pr_debug("%s: desc len too short: %d", __func__, dl);
220                 return NULL;
221         }
222 
223         if (start + nl + dl > end) {
224                 pr_debug("%s: (start=%p + nl=%u + dl=%u)=%p > end=%p",
225                                 __func__, start, nl, dl, start + nl + dl, end);
226                 return NULL;
227         }
228 
229         ldl_ = (__be16 *)(ev->remainder + nl + dl - 2);
230         if (!IS_ALIGNED((uintptr_t)ldl_, 2))
231                 pr_warn("long desc len not aligned %p", ldl_);
232         ldl = be16_to_cpu(*ldl_);
233         if (ldl < 2) {
234                 pr_debug("%s: long desc len too short (ldl=%u)",
235                                 __func__, ldl);
236                 return NULL;
237         }
238 
239         if (start + nl + dl + ldl > end) {
240                 pr_debug("%s: start=%p + nl=%u + dl=%u + ldl=%u > end=%p",
241                                 __func__, start, nl, dl, ldl, end);
242                 return NULL;
243         }
244 
245         return start + nl + dl + ldl;
246 }
247 
248 static unsigned long h_get_24x7_catalog_page_(unsigned long phys_4096,
249                                               unsigned long version,
250                                               unsigned long index)
251 {
252         pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)",
253                         phys_4096, version, index);
254 
255         WARN_ON(!IS_ALIGNED(phys_4096, 4096));
256 
257         return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE,
258                         phys_4096, version, index);
259 }
260 
261 static unsigned long h_get_24x7_catalog_page(char page[],
262                                              u64 version, u32 index)
263 {
264         return h_get_24x7_catalog_page_(virt_to_phys(page),
265                                         version, index);
266 }
267 
268 static unsigned core_domains[] = {
269         HV_PERF_DOMAIN_PHYS_CORE,
270         HV_PERF_DOMAIN_VCPU_HOME_CORE,
271         HV_PERF_DOMAIN_VCPU_HOME_CHIP,
272         HV_PERF_DOMAIN_VCPU_HOME_NODE,
273         HV_PERF_DOMAIN_VCPU_REMOTE_NODE,
274 };
275 /* chip event data always yeilds a single event, core yeilds multiple */
276 #define MAX_EVENTS_PER_EVENT_DATA ARRAY_SIZE(core_domains)
277 
278 static char *event_fmt(struct hv_24x7_event_data *event, unsigned domain)
279 {
280         const char *sindex;
281         const char *lpar;
282 
283         if (is_physical_domain(domain)) {
284                 lpar = "0x0";
285                 sindex = "core";
286         } else {
287                 lpar = "?";
288                 sindex = "vcpu";
289         }
290 
291         return kasprintf(GFP_KERNEL,
292                         "domain=0x%x,offset=0x%x,%s=?,lpar=%s",
293                         domain,
294                         be16_to_cpu(event->event_counter_offs) +
295                                 be16_to_cpu(event->event_group_record_offs),
296                         sindex,
297                         lpar);
298 }
299 
300 /* Avoid trusting fw to NUL terminate strings */
301 static char *memdup_to_str(char *maybe_str, int max_len, gfp_t gfp)
302 {
303         return kasprintf(gfp, "%.*s", max_len, maybe_str);
304 }
305 
306 static ssize_t device_show_string(struct device *dev,
307                 struct device_attribute *attr, char *buf)
308 {
309         struct dev_ext_attribute *d;
310 
311         d = container_of(attr, struct dev_ext_attribute, attr);
312 
313         return sprintf(buf, "%s\n", (char *)d->var);
314 }
315 
316 static struct attribute *device_str_attr_create_(char *name, char *str)
317 {
318         struct dev_ext_attribute *attr = kzalloc(sizeof(*attr), GFP_KERNEL);
319 
320         if (!attr)
321                 return NULL;
322 
323         sysfs_attr_init(&attr->attr.attr);
324 
325         attr->var = str;
326         attr->attr.attr.name = name;
327         attr->attr.attr.mode = 0444;
328         attr->attr.show = device_show_string;
329 
330         return &attr->attr.attr;
331 }
332 
333 static struct attribute *device_str_attr_create(char *name, int name_max,
334                                                 int name_nonce,
335                                                 char *str, size_t str_max)
336 {
337         char *n;
338         char *s = memdup_to_str(str, str_max, GFP_KERNEL);
339         struct attribute *a;
340 
341         if (!s)
342                 return NULL;
343 
344         if (!name_nonce)
345                 n = kasprintf(GFP_KERNEL, "%.*s", name_max, name);
346         else
347                 n = kasprintf(GFP_KERNEL, "%.*s__%d", name_max, name,
348                                         name_nonce);
349         if (!n)
350                 goto out_s;
351 
352         a = device_str_attr_create_(n, s);
353         if (!a)
354                 goto out_n;
355 
356         return a;
357 out_n:
358         kfree(n);
359 out_s:
360         kfree(s);
361         return NULL;
362 }
363 
364 static void device_str_attr_destroy(struct attribute *attr)
365 {
366         struct dev_ext_attribute *d;
367 
368         d = container_of(attr, struct dev_ext_attribute, attr.attr);
369         kfree(d->var);
370         kfree(d->attr.attr.name);
371         kfree(d);
372 }
373 
374 static struct attribute *event_to_attr(unsigned ix,
375                                        struct hv_24x7_event_data *event,
376                                        unsigned domain,
377                                        int nonce)
378 {
379         int event_name_len;
380         char *ev_name, *a_ev_name, *val;
381         const char *ev_suffix;
382         struct attribute *attr;
383 
384         if (!domain_is_valid(domain)) {
385                 pr_warn("catalog event %u has invalid domain %u\n",
386                                 ix, domain);
387                 return NULL;
388         }
389 
390         val = event_fmt(event, domain);
391         if (!val)
392                 return NULL;
393 
394         ev_suffix = event_domain_suffix(domain);
395         ev_name = event_name(event, &event_name_len);
396         if (!nonce)
397                 a_ev_name = kasprintf(GFP_KERNEL, "%.*s%s",
398                                 (int)event_name_len, ev_name, ev_suffix);
399         else
400                 a_ev_name = kasprintf(GFP_KERNEL, "%.*s%s__%d",
401                                 (int)event_name_len, ev_name, ev_suffix, nonce);
402 
403         if (!a_ev_name)
404                 goto out_val;
405 
406         attr = device_str_attr_create_(a_ev_name, val);
407         if (!attr)
408                 goto out_name;
409 
410         return attr;
411 out_name:
412         kfree(a_ev_name);
413 out_val:
414         kfree(val);
415         return NULL;
416 }
417 
418 static struct attribute *event_to_desc_attr(struct hv_24x7_event_data *event,
419                                             int nonce)
420 {
421         int nl, dl;
422         char *name = event_name(event, &nl);
423         char *desc = event_desc(event, &dl);
424 
425         /* If there isn't a description, don't create the sysfs file */
426         if (!dl)
427                 return NULL;
428 
429         return device_str_attr_create(name, nl, nonce, desc, dl);
430 }
431 
432 static struct attribute *
433 event_to_long_desc_attr(struct hv_24x7_event_data *event, int nonce)
434 {
435         int nl, dl;
436         char *name = event_name(event, &nl);
437         char *desc = event_long_desc(event, &dl);
438 
439         /* If there isn't a description, don't create the sysfs file */
440         if (!dl)
441                 return NULL;
442 
443         return device_str_attr_create(name, nl, nonce, desc, dl);
444 }
445 
446 static ssize_t event_data_to_attrs(unsigned ix, struct attribute **attrs,
447                                    struct hv_24x7_event_data *event, int nonce)
448 {
449         unsigned i;
450 
451         switch (event->domain) {
452         case HV_PERF_DOMAIN_PHYS_CHIP:
453                 *attrs = event_to_attr(ix, event, event->domain, nonce);
454                 return 1;
455         case HV_PERF_DOMAIN_PHYS_CORE:
456                 for (i = 0; i < ARRAY_SIZE(core_domains); i++) {
457                         attrs[i] = event_to_attr(ix, event, core_domains[i],
458                                                 nonce);
459                         if (!attrs[i]) {
460                                 pr_warn("catalog event %u: individual attr %u "
461                                         "creation failure\n", ix, i);
462                                 for (; i; i--)
463                                         device_str_attr_destroy(attrs[i - 1]);
464                                 return -1;
465                         }
466                 }
467                 return i;
468         default:
469                 pr_warn("catalog event %u: domain %u is not allowed in the "
470                                 "catalog\n", ix, event->domain);
471                 return -1;
472         }
473 }
474 
475 static size_t event_to_attr_ct(struct hv_24x7_event_data *event)
476 {
477         switch (event->domain) {
478         case HV_PERF_DOMAIN_PHYS_CHIP:
479                 return 1;
480         case HV_PERF_DOMAIN_PHYS_CORE:
481                 return ARRAY_SIZE(core_domains);
482         default:
483                 return 0;
484         }
485 }
486 
487 static unsigned long vmalloc_to_phys(void *v)
488 {
489         struct page *p = vmalloc_to_page(v);
490 
491         BUG_ON(!p);
492         return page_to_phys(p) + offset_in_page(v);
493 }
494 
495 /* */
496 struct event_uniq {
497         struct rb_node node;
498         const char *name;
499         int nl;
500         unsigned ct;
501         unsigned domain;
502 };
503 
504 static int memord(const void *d1, size_t s1, const void *d2, size_t s2)
505 {
506         if (s1 < s2)
507                 return 1;
508         if (s2 > s1)
509                 return -1;
510 
511         return memcmp(d1, d2, s1);
512 }
513 
514 static int ev_uniq_ord(const void *v1, size_t s1, unsigned d1, const void *v2,
515                        size_t s2, unsigned d2)
516 {
517         int r = memord(v1, s1, v2, s2);
518 
519         if (r)
520                 return r;
521         if (d1 > d2)
522                 return 1;
523         if (d2 > d1)
524                 return -1;
525         return 0;
526 }
527 
528 static int event_uniq_add(struct rb_root *root, const char *name, int nl,
529                           unsigned domain)
530 {
531         struct rb_node **new = &(root->rb_node), *parent = NULL;
532         struct event_uniq *data;
533 
534         /* Figure out where to put new node */
535         while (*new) {
536                 struct event_uniq *it;
537                 int result;
538 
539                 it = container_of(*new, struct event_uniq, node);
540                 result = ev_uniq_ord(name, nl, domain, it->name, it->nl,
541                                         it->domain);
542 
543                 parent = *new;
544                 if (result < 0)
545                         new = &((*new)->rb_left);
546                 else if (result > 0)
547                         new = &((*new)->rb_right);
548                 else {
549                         it->ct++;
550                         pr_info("found a duplicate event %.*s, ct=%u\n", nl,
551                                                 name, it->ct);
552                         return it->ct;
553                 }
554         }
555 
556         data = kmalloc(sizeof(*data), GFP_KERNEL);
557         if (!data)
558                 return -ENOMEM;
559 
560         *data = (struct event_uniq) {
561                 .name = name,
562                 .nl = nl,
563                 .ct = 0,
564                 .domain = domain,
565         };
566 
567         /* Add new node and rebalance tree. */
568         rb_link_node(&data->node, parent, new);
569         rb_insert_color(&data->node, root);
570 
571         /* data->ct */
572         return 0;
573 }
574 
575 static void event_uniq_destroy(struct rb_root *root)
576 {
577         /*
578          * the strings we point to are in the giant block of memory filled by
579          * the catalog, and are freed separately.
580          */
581         struct event_uniq *pos, *n;
582 
583         rbtree_postorder_for_each_entry_safe(pos, n, root, node)
584                 kfree(pos);
585 }
586 
587 
588 /*
589  * ensure the event structure's sizes are self consistent and don't cause us to
590  * read outside of the event
591  *
592  * On success, return the event length in bytes.
593  * Otherwise, return -1 (and print as appropriate).
594  */
595 static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
596                                           size_t event_idx,
597                                           size_t event_data_bytes,
598                                           size_t event_entry_count,
599                                           size_t offset, void *end)
600 {
601         ssize_t ev_len;
602         void *ev_end, *calc_ev_end;
603 
604         if (offset >= event_data_bytes)
605                 return -1;
606 
607         if (event_idx >= event_entry_count) {
608                 pr_devel("catalog event data has %zu bytes of padding after last event\n",
609                                 event_data_bytes - offset);
610                 return -1;
611         }
612 
613         if (!event_fixed_portion_is_within(event, end)) {
614                 pr_warn("event %zu fixed portion is not within range\n",
615                                 event_idx);
616                 return -1;
617         }
618 
619         ev_len = be16_to_cpu(event->length);
620 
621         if (ev_len % 16)
622                 pr_info("event %zu has length %zu not divisible by 16: event=%pK\n",
623                                 event_idx, ev_len, event);
624 
625         ev_end = (__u8 *)event + ev_len;
626         if (ev_end > end) {
627                 pr_warn("event %zu has .length=%zu, ends after buffer end: ev_end=%pK > end=%pK, offset=%zu\n",
628                                 event_idx, ev_len, ev_end, end,
629                                 offset);
630                 return -1;
631         }
632 
633         calc_ev_end = event_end(event, end);
634         if (!calc_ev_end) {
635                 pr_warn("event %zu has a calculated length which exceeds buffer length %zu: event=%pK end=%pK, offset=%zu\n",
636                         event_idx, event_data_bytes, event, end,
637                         offset);
638                 return -1;
639         }
640 
641         if (calc_ev_end > ev_end) {
642                 pr_warn("event %zu exceeds it's own length: event=%pK, end=%pK, offset=%zu, calc_ev_end=%pK\n",
643                         event_idx, event, ev_end, offset, calc_ev_end);
644                 return -1;
645         }
646 
647         return ev_len;
648 }
649 
650 #define MAX_4K (SIZE_MAX / 4096)
651 
652 static int create_events_from_catalog(struct attribute ***events_,
653                                       struct attribute ***event_descs_,
654                                       struct attribute ***event_long_descs_)
655 {
656         unsigned long hret;
657         size_t catalog_len, catalog_page_len, event_entry_count,
658                event_data_len, event_data_offs,
659                event_data_bytes, junk_events, event_idx, event_attr_ct, i,
660                attr_max, event_idx_last, desc_ct, long_desc_ct;
661         ssize_t ct, ev_len;
662         uint32_t catalog_version_num;
663         struct attribute **events, **event_descs, **event_long_descs;
664         struct hv_24x7_catalog_page_0 *page_0 =
665                 kmem_cache_alloc(hv_page_cache, GFP_KERNEL);
666         void *page = page_0;
667         void *event_data, *end;
668         struct hv_24x7_event_data *event;
669         struct rb_root ev_uniq = RB_ROOT;
670         int ret = 0;
671 
672         if (!page) {
673                 ret = -ENOMEM;
674                 goto e_out;
675         }
676 
677         hret = h_get_24x7_catalog_page(page, 0, 0);
678         if (hret) {
679                 ret = -EIO;
680                 goto e_free;
681         }
682 
683         catalog_version_num = be64_to_cpu(page_0->version);
684         catalog_page_len = be32_to_cpu(page_0->length);
685 
686         if (MAX_4K < catalog_page_len) {
687                 pr_err("invalid page count: %zu\n", catalog_page_len);
688                 ret = -EIO;
689                 goto e_free;
690         }
691 
692         catalog_len = catalog_page_len * 4096;
693 
694         event_entry_count = be16_to_cpu(page_0->event_entry_count);
695         event_data_offs   = be16_to_cpu(page_0->event_data_offs);
696         event_data_len    = be16_to_cpu(page_0->event_data_len);
697 
698         pr_devel("cv %zu cl %zu eec %zu edo %zu edl %zu\n",
699                         (size_t)catalog_version_num, catalog_len,
700                         event_entry_count, event_data_offs, event_data_len);
701 
702         if ((MAX_4K < event_data_len)
703                         || (MAX_4K < event_data_offs)
704                         || (MAX_4K - event_data_offs < event_data_len)) {
705                 pr_err("invalid event data offs %zu and/or len %zu\n",
706                                 event_data_offs, event_data_len);
707                 ret = -EIO;
708                 goto e_free;
709         }
710 
711         if ((event_data_offs + event_data_len) > catalog_page_len) {
712                 pr_err("event data %zu-%zu does not fit inside catalog 0-%zu\n",
713                                 event_data_offs,
714                                 event_data_offs + event_data_len,
715                                 catalog_page_len);
716                 ret = -EIO;
717                 goto e_free;
718         }
719 
720         if (SIZE_MAX / MAX_EVENTS_PER_EVENT_DATA - 1 < event_entry_count) {
721                 pr_err("event_entry_count %zu is invalid\n",
722                                 event_entry_count);
723                 ret = -EIO;
724                 goto e_free;
725         }
726 
727         event_data_bytes = event_data_len * 4096;
728 
729         /*
730          * event data can span several pages, events can cross between these
731          * pages. Use vmalloc to make this easier.
732          */
733         event_data = vmalloc(event_data_bytes);
734         if (!event_data) {
735                 pr_err("could not allocate event data\n");
736                 ret = -ENOMEM;
737                 goto e_free;
738         }
739 
740         end = event_data + event_data_bytes;
741 
742         /*
743          * using vmalloc_to_phys() like this only works if PAGE_SIZE is
744          * divisible by 4096
745          */
746         BUILD_BUG_ON(PAGE_SIZE % 4096);
747 
748         for (i = 0; i < event_data_len; i++) {
749                 hret = h_get_24x7_catalog_page_(
750                                 vmalloc_to_phys(event_data + i * 4096),
751                                 catalog_version_num,
752                                 i + event_data_offs);
753                 if (hret) {
754                         pr_err("failed to get event data in page %zu\n",
755                                         i + event_data_offs);
756                         ret = -EIO;
757                         goto e_event_data;
758                 }
759         }
760 
761         /*
762          * scan the catalog to determine the number of attributes we need, and
763          * verify it at the same time.
764          */
765         for (junk_events = 0, event = event_data, event_idx = 0, attr_max = 0;
766              ;
767              event_idx++, event = (void *)event + ev_len) {
768                 size_t offset = (void *)event - (void *)event_data;
769                 char *name;
770                 int nl;
771 
772                 ev_len = catalog_event_len_validate(event, event_idx,
773                                                     event_data_bytes,
774                                                     event_entry_count,
775                                                     offset, end);
776                 if (ev_len < 0)
777                         break;
778 
779                 name = event_name(event, &nl);
780 
781                 if (event->event_group_record_len == 0) {
782                         pr_devel("invalid event %zu (%.*s): group_record_len == 0, skipping\n",
783                                         event_idx, nl, name);
784                         junk_events++;
785                         continue;
786                 }
787 
788                 if (!catalog_entry_domain_is_valid(event->domain)) {
789                         pr_info("event %zu (%.*s) has invalid domain %d\n",
790                                         event_idx, nl, name, event->domain);
791                         junk_events++;
792                         continue;
793                 }
794 
795                 attr_max += event_to_attr_ct(event);
796         }
797 
798         event_idx_last = event_idx;
799         if (event_idx_last != event_entry_count)
800                 pr_warn("event buffer ended before listed # of events were parsed (got %zu, wanted %zu, junk %zu)\n",
801                                 event_idx_last, event_entry_count, junk_events);
802 
803         events = kmalloc_array(attr_max + 1, sizeof(*events), GFP_KERNEL);
804         if (!events) {
805                 ret = -ENOMEM;
806                 goto e_event_data;
807         }
808 
809         event_descs = kmalloc_array(event_idx + 1, sizeof(*event_descs),
810                                 GFP_KERNEL);
811         if (!event_descs) {
812                 ret = -ENOMEM;
813                 goto e_event_attrs;
814         }
815 
816         event_long_descs = kmalloc_array(event_idx + 1,
817                         sizeof(*event_long_descs), GFP_KERNEL);
818         if (!event_long_descs) {
819                 ret = -ENOMEM;
820                 goto e_event_descs;
821         }
822 
823         /* Iterate over the catalog filling in the attribute vector */
824         for (junk_events = 0, event_attr_ct = 0, desc_ct = 0, long_desc_ct = 0,
825                                 event = event_data, event_idx = 0;
826                         event_idx < event_idx_last;
827                         event_idx++, ev_len = be16_to_cpu(event->length),
828                                 event = (void *)event + ev_len) {
829                 char *name;
830                 int nl;
831                 int nonce;
832                 /*
833                  * these are the only "bad" events that are intermixed and that
834                  * we can ignore without issue. make sure to skip them here
835                  */
836                 if (event->event_group_record_len == 0)
837                         continue;
838                 if (!catalog_entry_domain_is_valid(event->domain))
839                         continue;
840 
841                 name  = event_name(event, &nl);
842                 nonce = event_uniq_add(&ev_uniq, name, nl, event->domain);
843                 ct    = event_data_to_attrs(event_idx, events + event_attr_ct,
844                                             event, nonce);
845                 if (ct <= 0) {
846                         pr_warn("event %zu (%.*s) creation failure, skipping\n",
847                                 event_idx, nl, name);
848                         junk_events++;
849                 } else {
850                         event_attr_ct += ct;
851                         event_descs[desc_ct] = event_to_desc_attr(event, nonce);
852                         if (event_descs[desc_ct])
853                                 desc_ct++;
854                         event_long_descs[long_desc_ct] =
855                                         event_to_long_desc_attr(event, nonce);
856                         if (event_long_descs[long_desc_ct])
857                                 long_desc_ct++;
858                 }
859         }
860 
861         pr_info("read %zu catalog entries, created %zu event attrs (%zu failures), %zu descs\n",
862                         event_idx, event_attr_ct, junk_events, desc_ct);
863 
864         events[event_attr_ct] = NULL;
865         event_descs[desc_ct] = NULL;
866         event_long_descs[long_desc_ct] = NULL;
867 
868         event_uniq_destroy(&ev_uniq);
869         vfree(event_data);
870         kmem_cache_free(hv_page_cache, page);
871 
872         *events_ = events;
873         *event_descs_ = event_descs;
874         *event_long_descs_ = event_long_descs;
875         return 0;
876 
877 e_event_descs:
878         kfree(event_descs);
879 e_event_attrs:
880         kfree(events);
881 e_event_data:
882         vfree(event_data);
883 e_free:
884         kmem_cache_free(hv_page_cache, page);
885 e_out:
886         *events_ = NULL;
887         *event_descs_ = NULL;
888         *event_long_descs_ = NULL;
889         return ret;
890 }
891 
892 static ssize_t catalog_read(struct file *filp, struct kobject *kobj,
893                             struct bin_attribute *bin_attr, char *buf,
894                             loff_t offset, size_t count)
895 {
896         unsigned long hret;
897         ssize_t ret = 0;
898         size_t catalog_len = 0, catalog_page_len = 0;
899         loff_t page_offset = 0;
900         loff_t offset_in_page;
901         size_t copy_len;
902         uint64_t catalog_version_num = 0;
903         void *page = kmem_cache_alloc(hv_page_cache, GFP_USER);
904         struct hv_24x7_catalog_page_0 *page_0 = page;
905 
906         if (!page)
907                 return -ENOMEM;
908 
909         hret = h_get_24x7_catalog_page(page, 0, 0);
910         if (hret) {
911                 ret = -EIO;
912                 goto e_free;
913         }
914 
915         catalog_version_num = be64_to_cpu(page_0->version);
916         catalog_page_len = be32_to_cpu(page_0->length);
917         catalog_len = catalog_page_len * 4096;
918 
919         page_offset = offset / 4096;
920         offset_in_page = offset % 4096;
921 
922         if (page_offset >= catalog_page_len)
923                 goto e_free;
924 
925         if (page_offset != 0) {
926                 hret = h_get_24x7_catalog_page(page, catalog_version_num,
927                                                page_offset);
928                 if (hret) {
929                         ret = -EIO;
930                         goto e_free;
931                 }
932         }
933 
934         copy_len = 4096 - offset_in_page;
935         if (copy_len > count)
936                 copy_len = count;
937 
938         memcpy(buf, page+offset_in_page, copy_len);
939         ret = copy_len;
940 
941 e_free:
942         if (hret)
943                 pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:"
944                        " rc=%ld\n",
945                        catalog_version_num, page_offset, hret);
946         kmem_cache_free(hv_page_cache, page);
947 
948         pr_devel("catalog_read: offset=%lld(%lld) count=%zu "
949                         "catalog_len=%zu(%zu) => %zd\n", offset, page_offset,
950                         count, catalog_len, catalog_page_len, ret);
951 
952         return ret;
953 }
954 
955 #define PAGE_0_ATTR(_name, _fmt, _expr)                         \
956 static ssize_t _name##_show(struct device *dev,                 \
957                             struct device_attribute *dev_attr,  \
958                             char *buf)                          \
959 {                                                               \
960         unsigned long hret;                                     \
961         ssize_t ret = 0;                                        \
962         void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \
963         struct hv_24x7_catalog_page_0 *page_0 = page;           \
964         if (!page)                                              \
965                 return -ENOMEM;                                 \
966         hret = h_get_24x7_catalog_page(page, 0, 0);             \
967         if (hret) {                                             \
968                 ret = -EIO;                                     \
969                 goto e_free;                                    \
970         }                                                       \
971         ret = sprintf(buf, _fmt, _expr);                        \
972 e_free:                                                         \
973         kmem_cache_free(hv_page_cache, page);                   \
974         return ret;                                             \
975 }                                                               \
976 static DEVICE_ATTR_RO(_name)
977 
978 PAGE_0_ATTR(catalog_version, "%lld\n",
979                 (unsigned long long)be64_to_cpu(page_0->version));
980 PAGE_0_ATTR(catalog_len, "%lld\n",
981                 (unsigned long long)be32_to_cpu(page_0->length) * 4096);
982 static BIN_ATTR_RO(catalog, 0/* real length varies */);
983 
984 static struct bin_attribute *if_bin_attrs[] = {
985         &bin_attr_catalog,
986         NULL,
987 };
988 
989 static struct attribute *if_attrs[] = {
990         &dev_attr_catalog_len.attr,
991         &dev_attr_catalog_version.attr,
992         NULL,
993 };
994 
995 static struct attribute_group if_group = {
996         .name = "interface",
997         .bin_attrs = if_bin_attrs,
998         .attrs = if_attrs,
999 };
1000 
1001 static const struct attribute_group *attr_groups[] = {
1002         &format_group,
1003         &event_group,
1004         &event_desc_group,
1005         &event_long_desc_group,
1006         &if_group,
1007         NULL,
1008 };
1009 
1010 static void log_24x7_hcall(struct hv_24x7_request_buffer *request_buffer,
1011                            struct hv_24x7_data_result_buffer *result_buffer,
1012                            unsigned long ret)
1013 {
1014         struct hv_24x7_request *req;
1015 
1016         req = &request_buffer->requests[0];
1017         pr_notice_ratelimited("hcall failed: [%d %#x %#x %d] => "
1018                         "ret 0x%lx (%ld) detail=0x%x failing ix=%x\n",
1019                         req->performance_domain, req->data_offset,
1020                         req->starting_ix, req->starting_lpar_ix, ret, ret,
1021                         result_buffer->detailed_rc,
1022                         result_buffer->failing_request_ix);
1023 }
1024 
1025 /*
1026  * Start the process for a new H_GET_24x7_DATA hcall.
1027  */
1028 static void init_24x7_request(struct hv_24x7_request_buffer *request_buffer,
1029                               struct hv_24x7_data_result_buffer *result_buffer)
1030 {
1031 
1032         memset(request_buffer, 0, 4096);
1033         memset(result_buffer, 0, 4096);
1034 
1035         request_buffer->interface_version = HV_24X7_IF_VERSION_CURRENT;
1036         /* memset above set request_buffer->num_requests to 0 */
1037 }
1038 
1039 /*
1040  * Commit (i.e perform) the H_GET_24x7_DATA hcall using the data collected
1041  * by 'init_24x7_request()' and 'add_event_to_24x7_request()'.
1042  */
1043 static int make_24x7_request(struct hv_24x7_request_buffer *request_buffer,
1044                              struct hv_24x7_data_result_buffer *result_buffer)
1045 {
1046         unsigned long ret;
1047 
1048         /*
1049          * NOTE: Due to variable number of array elements in request and
1050          *       result buffer(s), sizeof() is not reliable. Use the actual
1051          *       allocated buffer size, H24x7_DATA_BUFFER_SIZE.
1052          */
1053         ret = plpar_hcall_norets(H_GET_24X7_DATA,
1054                         virt_to_phys(request_buffer), H24x7_DATA_BUFFER_SIZE,
1055                         virt_to_phys(result_buffer),  H24x7_DATA_BUFFER_SIZE);
1056 
1057         if (ret)
1058                 log_24x7_hcall(request_buffer, result_buffer, ret);
1059 
1060         return ret;
1061 }
1062 
1063 /*
1064  * Add the given @event to the next slot in the 24x7 request_buffer.
1065  *
1066  * Note that H_GET_24X7_DATA hcall allows reading several counters'
1067  * values in a single HCALL. We expect the caller to add events to the
1068  * request buffer one by one, make the HCALL and process the results.
1069  */
1070 static int add_event_to_24x7_request(struct perf_event *event,
1071                                 struct hv_24x7_request_buffer *request_buffer)
1072 {
1073         u16 idx;
1074         int i;
1075         struct hv_24x7_request *req;
1076 
1077         if (request_buffer->num_requests > 254) {
1078                 pr_devel("Too many requests for 24x7 HCALL %d\n",
1079                                 request_buffer->num_requests);
1080                 return -EINVAL;
1081         }
1082 
1083         if (is_physical_domain(event_get_domain(event)))
1084                 idx = event_get_core(event);
1085         else
1086                 idx = event_get_vcpu(event);
1087 
1088         i = request_buffer->num_requests++;
1089         req = &request_buffer->requests[i];
1090 
1091         req->performance_domain = event_get_domain(event);
1092         req->data_size = cpu_to_be16(8);
1093         req->data_offset = cpu_to_be32(event_get_offset(event));
1094         req->starting_lpar_ix = cpu_to_be16(event_get_lpar(event)),
1095         req->max_num_lpars = cpu_to_be16(1);
1096         req->starting_ix = cpu_to_be16(idx);
1097         req->max_ix = cpu_to_be16(1);
1098 
1099         return 0;
1100 }
1101 
1102 static unsigned long single_24x7_request(struct perf_event *event, u64 *count)
1103 {
1104         unsigned long ret;
1105         struct hv_24x7_request_buffer *request_buffer;
1106         struct hv_24x7_data_result_buffer *result_buffer;
1107 
1108         BUILD_BUG_ON(sizeof(*request_buffer) > 4096);
1109         BUILD_BUG_ON(sizeof(*result_buffer) > 4096);
1110 
1111         request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1112         result_buffer = (void *)get_cpu_var(hv_24x7_resb);
1113 
1114         init_24x7_request(request_buffer, result_buffer);
1115 
1116         ret = add_event_to_24x7_request(event, request_buffer);
1117         if (ret)
1118                 goto out;
1119 
1120         ret = make_24x7_request(request_buffer, result_buffer);
1121         if (ret) {
1122                 log_24x7_hcall(request_buffer, result_buffer, ret);
1123                 goto out;
1124         }
1125 
1126         /* process result from hcall */
1127         *count = be64_to_cpu(result_buffer->results[0].elements[0].element_data[0]);
1128 
1129 out:
1130         put_cpu_var(hv_24x7_reqb);
1131         put_cpu_var(hv_24x7_resb);
1132         return ret;
1133 }
1134 
1135 
1136 static int h_24x7_event_init(struct perf_event *event)
1137 {
1138         struct hv_perf_caps caps;
1139         unsigned domain;
1140         unsigned long hret;
1141         u64 ct;
1142 
1143         /* Not our event */
1144         if (event->attr.type != event->pmu->type)
1145                 return -ENOENT;
1146 
1147         /* Unused areas must be 0 */
1148         if (event_get_reserved1(event) ||
1149             event_get_reserved2(event) ||
1150             event_get_reserved3(event)) {
1151                 pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n",
1152                                 event->attr.config,
1153                                 event_get_reserved1(event),
1154                                 event->attr.config1,
1155                                 event_get_reserved2(event),
1156                                 event->attr.config2,
1157                                 event_get_reserved3(event));
1158                 return -EINVAL;
1159         }
1160 
1161         /* unsupported modes and filters */
1162         if (event->attr.exclude_user   ||
1163             event->attr.exclude_kernel ||
1164             event->attr.exclude_hv     ||
1165             event->attr.exclude_idle   ||
1166             event->attr.exclude_host   ||
1167             event->attr.exclude_guest)
1168                 return -EINVAL;
1169 
1170         /* no branch sampling */
1171         if (has_branch_stack(event))
1172                 return -EOPNOTSUPP;
1173 
1174         /* offset must be 8 byte aligned */
1175         if (event_get_offset(event) % 8) {
1176                 pr_devel("bad alignment\n");
1177                 return -EINVAL;
1178         }
1179 
1180         /* Domains above 6 are invalid */
1181         domain = event_get_domain(event);
1182         if (domain > 6) {
1183                 pr_devel("invalid domain %d\n", domain);
1184                 return -EINVAL;
1185         }
1186 
1187         hret = hv_perf_caps_get(&caps);
1188         if (hret) {
1189                 pr_devel("could not get capabilities: rc=%ld\n", hret);
1190                 return -EIO;
1191         }
1192 
1193         /* Physical domains & other lpars require extra capabilities */
1194         if (!caps.collect_privileged && (is_physical_domain(domain) ||
1195                 (event_get_lpar(event) != event_get_lpar_max()))) {
1196                 pr_devel("hv permissions disallow: is_physical_domain:%d, lpar=0x%llx\n",
1197                                 is_physical_domain(domain),
1198                                 event_get_lpar(event));
1199                 return -EACCES;
1200         }
1201 
1202         /* see if the event complains */
1203         if (single_24x7_request(event, &ct)) {
1204                 pr_devel("test hcall failed\n");
1205                 return -EIO;
1206         }
1207 
1208         return 0;
1209 }
1210 
1211 static u64 h_24x7_get_value(struct perf_event *event)
1212 {
1213         unsigned long ret;
1214         u64 ct;
1215         ret = single_24x7_request(event, &ct);
1216         if (ret)
1217                 /* We checked this in event init, shouldn't fail here... */
1218                 return 0;
1219 
1220         return ct;
1221 }
1222 
1223 static void update_event_count(struct perf_event *event, u64 now)
1224 {
1225         s64 prev;
1226 
1227         prev = local64_xchg(&event->hw.prev_count, now);
1228         local64_add(now - prev, &event->count);
1229 }
1230 
1231 static void h_24x7_event_read(struct perf_event *event)
1232 {
1233         u64 now;
1234 
1235         now = h_24x7_get_value(event);
1236         update_event_count(event, now);
1237 }
1238 
1239 static void h_24x7_event_start(struct perf_event *event, int flags)
1240 {
1241         if (flags & PERF_EF_RELOAD)
1242                 local64_set(&event->hw.prev_count, h_24x7_get_value(event));
1243 }
1244 
1245 static void h_24x7_event_stop(struct perf_event *event, int flags)
1246 {
1247         h_24x7_event_read(event);
1248 }
1249 
1250 static int h_24x7_event_add(struct perf_event *event, int flags)
1251 {
1252         if (flags & PERF_EF_START)
1253                 h_24x7_event_start(event, flags);
1254 
1255         return 0;
1256 }
1257 
1258 static struct pmu h_24x7_pmu = {
1259         .task_ctx_nr = perf_invalid_context,
1260 
1261         .name = "hv_24x7",
1262         .attr_groups = attr_groups,
1263         .event_init  = h_24x7_event_init,
1264         .add         = h_24x7_event_add,
1265         .del         = h_24x7_event_stop,
1266         .start       = h_24x7_event_start,
1267         .stop        = h_24x7_event_stop,
1268         .read        = h_24x7_event_read,
1269 };
1270 
1271 static int hv_24x7_init(void)
1272 {
1273         int r;
1274         unsigned long hret;
1275         struct hv_perf_caps caps;
1276 
1277         if (!firmware_has_feature(FW_FEATURE_LPAR)) {
1278                 pr_debug("not a virtualized system, not enabling\n");
1279                 return -ENODEV;
1280         }
1281 
1282         hret = hv_perf_caps_get(&caps);
1283         if (hret) {
1284                 pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
1285                                 hret);
1286                 return -ENODEV;
1287         }
1288 
1289         hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL);
1290         if (!hv_page_cache)
1291                 return -ENOMEM;
1292 
1293         /* sampling not supported */
1294         h_24x7_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1295 
1296         r = create_events_from_catalog(&event_group.attrs,
1297                                    &event_desc_group.attrs,
1298                                    &event_long_desc_group.attrs);
1299 
1300         if (r)
1301                 return r;
1302 
1303         r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
1304         if (r)
1305                 return r;
1306 
1307         return 0;
1308 }
1309 
1310 device_initcall(hv_24x7_init);
1311 

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