~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

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

Version: ~ [ linux-5.4-rc3 ] ~ [ linux-5.3.6 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.79 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.149 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.196 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.196 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.75 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 bool domain_is_valid(unsigned domain)
 31 {
 32         switch (domain) {
 33 #define DOMAIN(n, v, x, c)              \
 34         case HV_PERF_DOMAIN_##n:        \
 35                 /* fall through */
 36 #include "hv-24x7-domains.h"
 37 #undef DOMAIN
 38                 return true;
 39         default:
 40                 return false;
 41         }
 42 }
 43 
 44 static bool is_physical_domain(unsigned domain)
 45 {
 46         switch (domain) {
 47 #define DOMAIN(n, v, x, c)              \
 48         case HV_PERF_DOMAIN_##n:        \
 49                 return c;
 50 #include "hv-24x7-domains.h"
 51 #undef DOMAIN
 52         default:
 53                 return false;
 54         }
 55 }
 56 
 57 static const char *domain_name(unsigned domain)
 58 {
 59         if (!domain_is_valid(domain))
 60                 return NULL;
 61 
 62         switch (domain) {
 63         case HV_PERF_DOMAIN_PHYS_CHIP:          return "Physical Chip";
 64         case HV_PERF_DOMAIN_PHYS_CORE:          return "Physical Core";
 65         case HV_PERF_DOMAIN_VCPU_HOME_CORE:     return "VCPU Home Core";
 66         case HV_PERF_DOMAIN_VCPU_HOME_CHIP:     return "VCPU Home Chip";
 67         case HV_PERF_DOMAIN_VCPU_HOME_NODE:     return "VCPU Home Node";
 68         case HV_PERF_DOMAIN_VCPU_REMOTE_NODE:   return "VCPU Remote Node";
 69         }
 70 
 71         WARN_ON_ONCE(domain);
 72         return NULL;
 73 }
 74 
 75 static bool catalog_entry_domain_is_valid(unsigned domain)
 76 {
 77         return is_physical_domain(domain);
 78 }
 79 
 80 /*
 81  * TODO: Merging events:
 82  * - Think of the hcall as an interface to a 4d array of counters:
 83  *   - x = domains
 84  *   - y = indexes in the domain (core, chip, vcpu, node, etc)
 85  *   - z = offset into the counter space
 86  *   - w = lpars (guest vms, "logical partitions")
 87  * - A single request is: x,y,y_last,z,z_last,w,w_last
 88  *   - this means we can retrieve a rectangle of counters in y,z for a single x.
 89  *
 90  * - Things to consider (ignoring w):
 91  *   - input  cost_per_request = 16
 92  *   - output cost_per_result(ys,zs)  = 8 + 8 * ys + ys * zs
 93  *   - limited number of requests per hcall (must fit into 4K bytes)
 94  *     - 4k = 16 [buffer header] - 16 [request size] * request_count
 95  *     - 255 requests per hcall
 96  *   - sometimes it will be more efficient to read extra data and discard
 97  */
 98 
 99 /*
100  * Example usage:
101  *  perf stat -e 'hv_24x7/domain=2,offset=8,vcpu=0,lpar=0xffffffff/'
102  */
103 
104 /* u3 0-6, one of HV_24X7_PERF_DOMAIN */
105 EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3);
106 /* u16 */
107 EVENT_DEFINE_RANGE_FORMAT(core, config, 16, 31);
108 EVENT_DEFINE_RANGE_FORMAT(chip, config, 16, 31);
109 EVENT_DEFINE_RANGE_FORMAT(vcpu, config, 16, 31);
110 /* u32, see "data_offset" */
111 EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63);
112 /* u16 */
113 EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15);
114 
115 EVENT_DEFINE_RANGE(reserved1, config,   4, 15);
116 EVENT_DEFINE_RANGE(reserved2, config1, 16, 63);
117 EVENT_DEFINE_RANGE(reserved3, config2,  0, 63);
118 
119 static struct attribute *format_attrs[] = {
120         &format_attr_domain.attr,
121         &format_attr_offset.attr,
122         &format_attr_core.attr,
123         &format_attr_chip.attr,
124         &format_attr_vcpu.attr,
125         &format_attr_lpar.attr,
126         NULL,
127 };
128 
129 static struct attribute_group format_group = {
130         .name = "format",
131         .attrs = format_attrs,
132 };
133 
134 static struct attribute_group event_group = {
135         .name = "events",
136         /* .attrs is set in init */
137 };
138 
139 static struct attribute_group event_desc_group = {
140         .name = "event_descs",
141         /* .attrs is set in init */
142 };
143 
144 static struct attribute_group event_long_desc_group = {
145         .name = "event_long_descs",
146         /* .attrs is set in init */
147 };
148 
149 static struct kmem_cache *hv_page_cache;
150 
151 DEFINE_PER_CPU(int, hv_24x7_txn_flags);
152 DEFINE_PER_CPU(int, hv_24x7_txn_err);
153 
154 struct hv_24x7_hw {
155         struct perf_event *events[255];
156 };
157 
158 DEFINE_PER_CPU(struct hv_24x7_hw, hv_24x7_hw);
159 
160 /*
161  * request_buffer and result_buffer are not required to be 4k aligned,
162  * but are not allowed to cross any 4k boundary. Aligning them to 4k is
163  * the simplest way to ensure that.
164  */
165 #define H24x7_DATA_BUFFER_SIZE  4096
166 DEFINE_PER_CPU(char, hv_24x7_reqb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
167 DEFINE_PER_CPU(char, hv_24x7_resb[H24x7_DATA_BUFFER_SIZE]) __aligned(4096);
168 
169 static char *event_name(struct hv_24x7_event_data *ev, int *len)
170 {
171         *len = be16_to_cpu(ev->event_name_len) - 2;
172         return (char *)ev->remainder;
173 }
174 
175 static char *event_desc(struct hv_24x7_event_data *ev, int *len)
176 {
177         unsigned nl = be16_to_cpu(ev->event_name_len);
178         __be16 *desc_len = (__be16 *)(ev->remainder + nl - 2);
179 
180         *len = be16_to_cpu(*desc_len) - 2;
181         return (char *)ev->remainder + nl;
182 }
183 
184 static char *event_long_desc(struct hv_24x7_event_data *ev, int *len)
185 {
186         unsigned nl = be16_to_cpu(ev->event_name_len);
187         __be16 *desc_len_ = (__be16 *)(ev->remainder + nl - 2);
188         unsigned desc_len = be16_to_cpu(*desc_len_);
189         __be16 *long_desc_len = (__be16 *)(ev->remainder + nl + desc_len - 2);
190 
191         *len = be16_to_cpu(*long_desc_len) - 2;
192         return (char *)ev->remainder + nl + desc_len;
193 }
194 
195 static bool event_fixed_portion_is_within(struct hv_24x7_event_data *ev,
196                                           void *end)
197 {
198         void *start = ev;
199 
200         return (start + offsetof(struct hv_24x7_event_data, remainder)) < end;
201 }
202 
203 /*
204  * Things we don't check:
205  *  - padding for desc, name, and long/detailed desc is required to be '\0'
206  *    bytes.
207  *
208  *  Return NULL if we pass end,
209  *  Otherwise return the address of the byte just following the event.
210  */
211 static void *event_end(struct hv_24x7_event_data *ev, void *end)
212 {
213         void *start = ev;
214         __be16 *dl_, *ldl_;
215         unsigned dl, ldl;
216         unsigned nl = be16_to_cpu(ev->event_name_len);
217 
218         if (nl < 2) {
219                 pr_debug("%s: name length too short: %d", __func__, nl);
220                 return NULL;
221         }
222 
223         if (start + nl > end) {
224                 pr_debug("%s: start=%p + nl=%u > end=%p",
225                                 __func__, start, nl, end);
226                 return NULL;
227         }
228 
229         dl_ = (__be16 *)(ev->remainder + nl - 2);
230         if (!IS_ALIGNED((uintptr_t)dl_, 2))
231                 pr_warn("desc len not aligned %p", dl_);
232         dl = be16_to_cpu(*dl_);
233         if (dl < 2) {
234                 pr_debug("%s: desc len too short: %d", __func__, dl);
235                 return NULL;
236         }
237 
238         if (start + nl + dl > end) {
239                 pr_debug("%s: (start=%p + nl=%u + dl=%u)=%p > end=%p",
240                                 __func__, start, nl, dl, start + nl + dl, end);
241                 return NULL;
242         }
243 
244         ldl_ = (__be16 *)(ev->remainder + nl + dl - 2);
245         if (!IS_ALIGNED((uintptr_t)ldl_, 2))
246                 pr_warn("long desc len not aligned %p", ldl_);
247         ldl = be16_to_cpu(*ldl_);
248         if (ldl < 2) {
249                 pr_debug("%s: long desc len too short (ldl=%u)",
250                                 __func__, ldl);
251                 return NULL;
252         }
253 
254         if (start + nl + dl + ldl > end) {
255                 pr_debug("%s: start=%p + nl=%u + dl=%u + ldl=%u > end=%p",
256                                 __func__, start, nl, dl, ldl, end);
257                 return NULL;
258         }
259 
260         return start + nl + dl + ldl;
261 }
262 
263 static unsigned long h_get_24x7_catalog_page_(unsigned long phys_4096,
264                                               unsigned long version,
265                                               unsigned long index)
266 {
267         pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)",
268                         phys_4096, version, index);
269 
270         WARN_ON(!IS_ALIGNED(phys_4096, 4096));
271 
272         return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE,
273                         phys_4096, version, index);
274 }
275 
276 static unsigned long h_get_24x7_catalog_page(char page[],
277                                              u64 version, u32 index)
278 {
279         return h_get_24x7_catalog_page_(virt_to_phys(page),
280                                         version, index);
281 }
282 
283 /*
284  * Each event we find in the catalog, will have a sysfs entry. Format the
285  * data for this sysfs entry based on the event's domain.
286  *
287  * Events belonging to the Chip domain can only be monitored in that domain.
288  * i.e the domain for these events is a fixed/knwon value.
289  *
290  * Events belonging to the Core domain can be monitored either in the physical
291  * core or in one of the virtual CPU domains. So the domain value for these
292  * events must be specified by the user (i.e is a required parameter). Format
293  * the Core events with 'domain=?' so the perf-tool can error check required
294  * parameters.
295  *
296  * NOTE: For the Core domain events, rather than making domain a required
297  *       parameter we could default it to PHYS_CORE and allowe users to
298  *       override the domain to one of the VCPU domains.
299  *
300  *       However, this can make the interface a little inconsistent.
301  *
302  *       If we set domain=2 (PHYS_CHIP) and allow user to override this field
303  *       the user may be tempted to also modify the "offset=x" field in which
304  *       can lead to confusing usage. Consider the HPM_PCYC (offset=0x18) and
305  *       HPM_INST (offset=0x20) events. With:
306  *
307  *              perf stat -e hv_24x7/HPM_PCYC,offset=0x20/
308  *
309  *      we end up monitoring HPM_INST, while the command line has HPM_PCYC.
310  *
311  *      By not assigning a default value to the domain for the Core events,
312  *      we can have simple guidelines:
313  *
314  *              - Specifying values for parameters with "=?" is required.
315  *
316  *              - Specifying (i.e overriding) values for other parameters
317  *                is undefined.
318  */
319 static char *event_fmt(struct hv_24x7_event_data *event, unsigned domain)
320 {
321         const char *sindex;
322         const char *lpar;
323         const char *domain_str;
324         char buf[8];
325 
326         switch (domain) {
327         case HV_PERF_DOMAIN_PHYS_CHIP:
328                 snprintf(buf, sizeof(buf), "%d", domain);
329                 domain_str = buf;
330                 lpar = "0x0";
331                 sindex = "chip";
332                 break;
333         case HV_PERF_DOMAIN_PHYS_CORE:
334                 domain_str = "?";
335                 lpar = "0x0";
336                 sindex = "core";
337                 break;
338         default:
339                 domain_str = "?";
340                 lpar = "?";
341                 sindex = "vcpu";
342         }
343 
344         return kasprintf(GFP_KERNEL,
345                         "domain=%s,offset=0x%x,%s=?,lpar=%s",
346                         domain_str,
347                         be16_to_cpu(event->event_counter_offs) +
348                                 be16_to_cpu(event->event_group_record_offs),
349                         sindex,
350                         lpar);
351 }
352 
353 /* Avoid trusting fw to NUL terminate strings */
354 static char *memdup_to_str(char *maybe_str, int max_len, gfp_t gfp)
355 {
356         return kasprintf(gfp, "%.*s", max_len, maybe_str);
357 }
358 
359 static ssize_t device_show_string(struct device *dev,
360                 struct device_attribute *attr, char *buf)
361 {
362         struct dev_ext_attribute *d;
363 
364         d = container_of(attr, struct dev_ext_attribute, attr);
365 
366         return sprintf(buf, "%s\n", (char *)d->var);
367 }
368 
369 static struct attribute *device_str_attr_create_(char *name, char *str)
370 {
371         struct dev_ext_attribute *attr = kzalloc(sizeof(*attr), GFP_KERNEL);
372 
373         if (!attr)
374                 return NULL;
375 
376         sysfs_attr_init(&attr->attr.attr);
377 
378         attr->var = str;
379         attr->attr.attr.name = name;
380         attr->attr.attr.mode = 0444;
381         attr->attr.show = device_show_string;
382 
383         return &attr->attr.attr;
384 }
385 
386 /*
387  * Allocate and initialize strings representing event attributes.
388  *
389  * NOTE: The strings allocated here are never destroyed and continue to
390  *       exist till shutdown. This is to allow us to create as many events
391  *       from the catalog as possible, even if we encounter errors with some.
392  *       In case of changes to error paths in future, these may need to be
393  *       freed by the caller.
394  */
395 static struct attribute *device_str_attr_create(char *name, int name_max,
396                                                 int name_nonce,
397                                                 char *str, size_t str_max)
398 {
399         char *n;
400         char *s = memdup_to_str(str, str_max, GFP_KERNEL);
401         struct attribute *a;
402 
403         if (!s)
404                 return NULL;
405 
406         if (!name_nonce)
407                 n = kasprintf(GFP_KERNEL, "%.*s", name_max, name);
408         else
409                 n = kasprintf(GFP_KERNEL, "%.*s__%d", name_max, name,
410                                         name_nonce);
411         if (!n)
412                 goto out_s;
413 
414         a = device_str_attr_create_(n, s);
415         if (!a)
416                 goto out_n;
417 
418         return a;
419 out_n:
420         kfree(n);
421 out_s:
422         kfree(s);
423         return NULL;
424 }
425 
426 static struct attribute *event_to_attr(unsigned ix,
427                                        struct hv_24x7_event_data *event,
428                                        unsigned domain,
429                                        int nonce)
430 {
431         int event_name_len;
432         char *ev_name, *a_ev_name, *val;
433         struct attribute *attr;
434 
435         if (!domain_is_valid(domain)) {
436                 pr_warn("catalog event %u has invalid domain %u\n",
437                                 ix, domain);
438                 return NULL;
439         }
440 
441         val = event_fmt(event, domain);
442         if (!val)
443                 return NULL;
444 
445         ev_name = event_name(event, &event_name_len);
446         if (!nonce)
447                 a_ev_name = kasprintf(GFP_KERNEL, "%.*s",
448                                 (int)event_name_len, ev_name);
449         else
450                 a_ev_name = kasprintf(GFP_KERNEL, "%.*s__%d",
451                                 (int)event_name_len, ev_name, nonce);
452 
453         if (!a_ev_name)
454                 goto out_val;
455 
456         attr = device_str_attr_create_(a_ev_name, val);
457         if (!attr)
458                 goto out_name;
459 
460         return attr;
461 out_name:
462         kfree(a_ev_name);
463 out_val:
464         kfree(val);
465         return NULL;
466 }
467 
468 static struct attribute *event_to_desc_attr(struct hv_24x7_event_data *event,
469                                             int nonce)
470 {
471         int nl, dl;
472         char *name = event_name(event, &nl);
473         char *desc = event_desc(event, &dl);
474 
475         /* If there isn't a description, don't create the sysfs file */
476         if (!dl)
477                 return NULL;
478 
479         return device_str_attr_create(name, nl, nonce, desc, dl);
480 }
481 
482 static struct attribute *
483 event_to_long_desc_attr(struct hv_24x7_event_data *event, int nonce)
484 {
485         int nl, dl;
486         char *name = event_name(event, &nl);
487         char *desc = event_long_desc(event, &dl);
488 
489         /* If there isn't a description, don't create the sysfs file */
490         if (!dl)
491                 return NULL;
492 
493         return device_str_attr_create(name, nl, nonce, desc, dl);
494 }
495 
496 static int event_data_to_attrs(unsigned ix, struct attribute **attrs,
497                                    struct hv_24x7_event_data *event, int nonce)
498 {
499         *attrs = event_to_attr(ix, event, event->domain, nonce);
500         if (!*attrs)
501                 return -1;
502 
503         return 0;
504 }
505 
506 /* */
507 struct event_uniq {
508         struct rb_node node;
509         const char *name;
510         int nl;
511         unsigned ct;
512         unsigned domain;
513 };
514 
515 static int memord(const void *d1, size_t s1, const void *d2, size_t s2)
516 {
517         if (s1 < s2)
518                 return 1;
519         if (s2 > s1)
520                 return -1;
521 
522         return memcmp(d1, d2, s1);
523 }
524 
525 static int ev_uniq_ord(const void *v1, size_t s1, unsigned d1, const void *v2,
526                        size_t s2, unsigned d2)
527 {
528         int r = memord(v1, s1, v2, s2);
529 
530         if (r)
531                 return r;
532         if (d1 > d2)
533                 return 1;
534         if (d2 > d1)
535                 return -1;
536         return 0;
537 }
538 
539 static int event_uniq_add(struct rb_root *root, const char *name, int nl,
540                           unsigned domain)
541 {
542         struct rb_node **new = &(root->rb_node), *parent = NULL;
543         struct event_uniq *data;
544 
545         /* Figure out where to put new node */
546         while (*new) {
547                 struct event_uniq *it;
548                 int result;
549 
550                 it = container_of(*new, struct event_uniq, node);
551                 result = ev_uniq_ord(name, nl, domain, it->name, it->nl,
552                                         it->domain);
553 
554                 parent = *new;
555                 if (result < 0)
556                         new = &((*new)->rb_left);
557                 else if (result > 0)
558                         new = &((*new)->rb_right);
559                 else {
560                         it->ct++;
561                         pr_info("found a duplicate event %.*s, ct=%u\n", nl,
562                                                 name, it->ct);
563                         return it->ct;
564                 }
565         }
566 
567         data = kmalloc(sizeof(*data), GFP_KERNEL);
568         if (!data)
569                 return -ENOMEM;
570 
571         *data = (struct event_uniq) {
572                 .name = name,
573                 .nl = nl,
574                 .ct = 0,
575                 .domain = domain,
576         };
577 
578         /* Add new node and rebalance tree. */
579         rb_link_node(&data->node, parent, new);
580         rb_insert_color(&data->node, root);
581 
582         /* data->ct */
583         return 0;
584 }
585 
586 static void event_uniq_destroy(struct rb_root *root)
587 {
588         /*
589          * the strings we point to are in the giant block of memory filled by
590          * the catalog, and are freed separately.
591          */
592         struct event_uniq *pos, *n;
593 
594         rbtree_postorder_for_each_entry_safe(pos, n, root, node)
595                 kfree(pos);
596 }
597 
598 
599 /*
600  * ensure the event structure's sizes are self consistent and don't cause us to
601  * read outside of the event
602  *
603  * On success, return the event length in bytes.
604  * Otherwise, return -1 (and print as appropriate).
605  */
606 static ssize_t catalog_event_len_validate(struct hv_24x7_event_data *event,
607                                           size_t event_idx,
608                                           size_t event_data_bytes,
609                                           size_t event_entry_count,
610                                           size_t offset, void *end)
611 {
612         ssize_t ev_len;
613         void *ev_end, *calc_ev_end;
614 
615         if (offset >= event_data_bytes)
616                 return -1;
617 
618         if (event_idx >= event_entry_count) {
619                 pr_devel("catalog event data has %zu bytes of padding after last event\n",
620                                 event_data_bytes - offset);
621                 return -1;
622         }
623 
624         if (!event_fixed_portion_is_within(event, end)) {
625                 pr_warn("event %zu fixed portion is not within range\n",
626                                 event_idx);
627                 return -1;
628         }
629 
630         ev_len = be16_to_cpu(event->length);
631 
632         if (ev_len % 16)
633                 pr_info("event %zu has length %zu not divisible by 16: event=%pK\n",
634                                 event_idx, ev_len, event);
635 
636         ev_end = (__u8 *)event + ev_len;
637         if (ev_end > end) {
638                 pr_warn("event %zu has .length=%zu, ends after buffer end: ev_end=%pK > end=%pK, offset=%zu\n",
639                                 event_idx, ev_len, ev_end, end,
640                                 offset);
641                 return -1;
642         }
643 
644         calc_ev_end = event_end(event, end);
645         if (!calc_ev_end) {
646                 pr_warn("event %zu has a calculated length which exceeds buffer length %zu: event=%pK end=%pK, offset=%zu\n",
647                         event_idx, event_data_bytes, event, end,
648                         offset);
649                 return -1;
650         }
651 
652         if (calc_ev_end > ev_end) {
653                 pr_warn("event %zu exceeds it's own length: event=%pK, end=%pK, offset=%zu, calc_ev_end=%pK\n",
654                         event_idx, event, ev_end, offset, calc_ev_end);
655                 return -1;
656         }
657 
658         return ev_len;
659 }
660 
661 #define MAX_4K (SIZE_MAX / 4096)
662 
663 static int create_events_from_catalog(struct attribute ***events_,
664                                       struct attribute ***event_descs_,
665                                       struct attribute ***event_long_descs_)
666 {
667         unsigned long hret;
668         size_t catalog_len, catalog_page_len, event_entry_count,
669                event_data_len, event_data_offs,
670                event_data_bytes, junk_events, event_idx, event_attr_ct, i,
671                attr_max, event_idx_last, desc_ct, long_desc_ct;
672         ssize_t ct, ev_len;
673         uint32_t catalog_version_num;
674         struct attribute **events, **event_descs, **event_long_descs;
675         struct hv_24x7_catalog_page_0 *page_0 =
676                 kmem_cache_alloc(hv_page_cache, GFP_KERNEL);
677         void *page = page_0;
678         void *event_data, *end;
679         struct hv_24x7_event_data *event;
680         struct rb_root ev_uniq = RB_ROOT;
681         int ret = 0;
682 
683         if (!page) {
684                 ret = -ENOMEM;
685                 goto e_out;
686         }
687 
688         hret = h_get_24x7_catalog_page(page, 0, 0);
689         if (hret) {
690                 ret = -EIO;
691                 goto e_free;
692         }
693 
694         catalog_version_num = be64_to_cpu(page_0->version);
695         catalog_page_len = be32_to_cpu(page_0->length);
696 
697         if (MAX_4K < catalog_page_len) {
698                 pr_err("invalid page count: %zu\n", catalog_page_len);
699                 ret = -EIO;
700                 goto e_free;
701         }
702 
703         catalog_len = catalog_page_len * 4096;
704 
705         event_entry_count = be16_to_cpu(page_0->event_entry_count);
706         event_data_offs   = be16_to_cpu(page_0->event_data_offs);
707         event_data_len    = be16_to_cpu(page_0->event_data_len);
708 
709         pr_devel("cv %zu cl %zu eec %zu edo %zu edl %zu\n",
710                         (size_t)catalog_version_num, catalog_len,
711                         event_entry_count, event_data_offs, event_data_len);
712 
713         if ((MAX_4K < event_data_len)
714                         || (MAX_4K < event_data_offs)
715                         || (MAX_4K - event_data_offs < event_data_len)) {
716                 pr_err("invalid event data offs %zu and/or len %zu\n",
717                                 event_data_offs, event_data_len);
718                 ret = -EIO;
719                 goto e_free;
720         }
721 
722         if ((event_data_offs + event_data_len) > catalog_page_len) {
723                 pr_err("event data %zu-%zu does not fit inside catalog 0-%zu\n",
724                                 event_data_offs,
725                                 event_data_offs + event_data_len,
726                                 catalog_page_len);
727                 ret = -EIO;
728                 goto e_free;
729         }
730 
731         if (SIZE_MAX - 1 < event_entry_count) {
732                 pr_err("event_entry_count %zu is invalid\n", event_entry_count);
733                 ret = -EIO;
734                 goto e_free;
735         }
736 
737         event_data_bytes = event_data_len * 4096;
738 
739         /*
740          * event data can span several pages, events can cross between these
741          * pages. Use vmalloc to make this easier.
742          */
743         event_data = vmalloc(event_data_bytes);
744         if (!event_data) {
745                 pr_err("could not allocate event data\n");
746                 ret = -ENOMEM;
747                 goto e_free;
748         }
749 
750         end = event_data + event_data_bytes;
751 
752         /*
753          * using vmalloc_to_phys() like this only works if PAGE_SIZE is
754          * divisible by 4096
755          */
756         BUILD_BUG_ON(PAGE_SIZE % 4096);
757 
758         for (i = 0; i < event_data_len; i++) {
759                 hret = h_get_24x7_catalog_page_(
760                                 vmalloc_to_phys(event_data + i * 4096),
761                                 catalog_version_num,
762                                 i + event_data_offs);
763                 if (hret) {
764                         pr_err("failed to get event data in page %zu\n",
765                                         i + event_data_offs);
766                         ret = -EIO;
767                         goto e_event_data;
768                 }
769         }
770 
771         /*
772          * scan the catalog to determine the number of attributes we need, and
773          * verify it at the same time.
774          */
775         for (junk_events = 0, event = event_data, event_idx = 0, attr_max = 0;
776              ;
777              event_idx++, event = (void *)event + ev_len) {
778                 size_t offset = (void *)event - (void *)event_data;
779                 char *name;
780                 int nl;
781 
782                 ev_len = catalog_event_len_validate(event, event_idx,
783                                                     event_data_bytes,
784                                                     event_entry_count,
785                                                     offset, end);
786                 if (ev_len < 0)
787                         break;
788 
789                 name = event_name(event, &nl);
790 
791                 if (event->event_group_record_len == 0) {
792                         pr_devel("invalid event %zu (%.*s): group_record_len == 0, skipping\n",
793                                         event_idx, nl, name);
794                         junk_events++;
795                         continue;
796                 }
797 
798                 if (!catalog_entry_domain_is_valid(event->domain)) {
799                         pr_info("event %zu (%.*s) has invalid domain %d\n",
800                                         event_idx, nl, name, event->domain);
801                         junk_events++;
802                         continue;
803                 }
804 
805                 attr_max++;
806         }
807 
808         event_idx_last = event_idx;
809         if (event_idx_last != event_entry_count)
810                 pr_warn("event buffer ended before listed # of events were parsed (got %zu, wanted %zu, junk %zu)\n",
811                                 event_idx_last, event_entry_count, junk_events);
812 
813         events = kmalloc_array(attr_max + 1, sizeof(*events), GFP_KERNEL);
814         if (!events) {
815                 ret = -ENOMEM;
816                 goto e_event_data;
817         }
818 
819         event_descs = kmalloc_array(event_idx + 1, sizeof(*event_descs),
820                                 GFP_KERNEL);
821         if (!event_descs) {
822                 ret = -ENOMEM;
823                 goto e_event_attrs;
824         }
825 
826         event_long_descs = kmalloc_array(event_idx + 1,
827                         sizeof(*event_long_descs), GFP_KERNEL);
828         if (!event_long_descs) {
829                 ret = -ENOMEM;
830                 goto e_event_descs;
831         }
832 
833         /* Iterate over the catalog filling in the attribute vector */
834         for (junk_events = 0, event_attr_ct = 0, desc_ct = 0, long_desc_ct = 0,
835                                 event = event_data, event_idx = 0;
836                         event_idx < event_idx_last;
837                         event_idx++, ev_len = be16_to_cpu(event->length),
838                                 event = (void *)event + ev_len) {
839                 char *name;
840                 int nl;
841                 int nonce;
842                 /*
843                  * these are the only "bad" events that are intermixed and that
844                  * we can ignore without issue. make sure to skip them here
845                  */
846                 if (event->event_group_record_len == 0)
847                         continue;
848                 if (!catalog_entry_domain_is_valid(event->domain))
849                         continue;
850 
851                 name  = event_name(event, &nl);
852                 nonce = event_uniq_add(&ev_uniq, name, nl, event->domain);
853                 ct    = event_data_to_attrs(event_idx, events + event_attr_ct,
854                                             event, nonce);
855                 if (ct < 0) {
856                         pr_warn("event %zu (%.*s) creation failure, skipping\n",
857                                 event_idx, nl, name);
858                         junk_events++;
859                 } else {
860                         event_attr_ct++;
861                         event_descs[desc_ct] = event_to_desc_attr(event, nonce);
862                         if (event_descs[desc_ct])
863                                 desc_ct++;
864                         event_long_descs[long_desc_ct] =
865                                         event_to_long_desc_attr(event, nonce);
866                         if (event_long_descs[long_desc_ct])
867                                 long_desc_ct++;
868                 }
869         }
870 
871         pr_info("read %zu catalog entries, created %zu event attrs (%zu failures), %zu descs\n",
872                         event_idx, event_attr_ct, junk_events, desc_ct);
873 
874         events[event_attr_ct] = NULL;
875         event_descs[desc_ct] = NULL;
876         event_long_descs[long_desc_ct] = NULL;
877 
878         event_uniq_destroy(&ev_uniq);
879         vfree(event_data);
880         kmem_cache_free(hv_page_cache, page);
881 
882         *events_ = events;
883         *event_descs_ = event_descs;
884         *event_long_descs_ = event_long_descs;
885         return 0;
886 
887 e_event_descs:
888         kfree(event_descs);
889 e_event_attrs:
890         kfree(events);
891 e_event_data:
892         vfree(event_data);
893 e_free:
894         kmem_cache_free(hv_page_cache, page);
895 e_out:
896         *events_ = NULL;
897         *event_descs_ = NULL;
898         *event_long_descs_ = NULL;
899         return ret;
900 }
901 
902 static ssize_t catalog_read(struct file *filp, struct kobject *kobj,
903                             struct bin_attribute *bin_attr, char *buf,
904                             loff_t offset, size_t count)
905 {
906         unsigned long hret;
907         ssize_t ret = 0;
908         size_t catalog_len = 0, catalog_page_len = 0;
909         loff_t page_offset = 0;
910         loff_t offset_in_page;
911         size_t copy_len;
912         uint64_t catalog_version_num = 0;
913         void *page = kmem_cache_alloc(hv_page_cache, GFP_USER);
914         struct hv_24x7_catalog_page_0 *page_0 = page;
915 
916         if (!page)
917                 return -ENOMEM;
918 
919         hret = h_get_24x7_catalog_page(page, 0, 0);
920         if (hret) {
921                 ret = -EIO;
922                 goto e_free;
923         }
924 
925         catalog_version_num = be64_to_cpu(page_0->version);
926         catalog_page_len = be32_to_cpu(page_0->length);
927         catalog_len = catalog_page_len * 4096;
928 
929         page_offset = offset / 4096;
930         offset_in_page = offset % 4096;
931 
932         if (page_offset >= catalog_page_len)
933                 goto e_free;
934 
935         if (page_offset != 0) {
936                 hret = h_get_24x7_catalog_page(page, catalog_version_num,
937                                                page_offset);
938                 if (hret) {
939                         ret = -EIO;
940                         goto e_free;
941                 }
942         }
943 
944         copy_len = 4096 - offset_in_page;
945         if (copy_len > count)
946                 copy_len = count;
947 
948         memcpy(buf, page+offset_in_page, copy_len);
949         ret = copy_len;
950 
951 e_free:
952         if (hret)
953                 pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:"
954                        " rc=%ld\n",
955                        catalog_version_num, page_offset, hret);
956         kmem_cache_free(hv_page_cache, page);
957 
958         pr_devel("catalog_read: offset=%lld(%lld) count=%zu "
959                         "catalog_len=%zu(%zu) => %zd\n", offset, page_offset,
960                         count, catalog_len, catalog_page_len, ret);
961 
962         return ret;
963 }
964 
965 static ssize_t domains_show(struct device *dev, struct device_attribute *attr,
966                             char *page)
967 {
968         int d, n, count = 0;
969         const char *str;
970 
971         for (d = 0; d < HV_PERF_DOMAIN_MAX; d++) {
972                 str = domain_name(d);
973                 if (!str)
974                         continue;
975 
976                 n = sprintf(page, "%d: %s\n", d, str);
977                 if (n < 0)
978                         break;
979 
980                 count += n;
981                 page += n;
982         }
983         return count;
984 }
985 
986 #define PAGE_0_ATTR(_name, _fmt, _expr)                         \
987 static ssize_t _name##_show(struct device *dev,                 \
988                             struct device_attribute *dev_attr,  \
989                             char *buf)                          \
990 {                                                               \
991         unsigned long hret;                                     \
992         ssize_t ret = 0;                                        \
993         void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \
994         struct hv_24x7_catalog_page_0 *page_0 = page;           \
995         if (!page)                                              \
996                 return -ENOMEM;                                 \
997         hret = h_get_24x7_catalog_page(page, 0, 0);             \
998         if (hret) {                                             \
999                 ret = -EIO;                                     \
1000                 goto e_free;                                    \
1001         }                                                       \
1002         ret = sprintf(buf, _fmt, _expr);                        \
1003 e_free:                                                         \
1004         kmem_cache_free(hv_page_cache, page);                   \
1005         return ret;                                             \
1006 }                                                               \
1007 static DEVICE_ATTR_RO(_name)
1008 
1009 PAGE_0_ATTR(catalog_version, "%lld\n",
1010                 (unsigned long long)be64_to_cpu(page_0->version));
1011 PAGE_0_ATTR(catalog_len, "%lld\n",
1012                 (unsigned long long)be32_to_cpu(page_0->length) * 4096);
1013 static BIN_ATTR_RO(catalog, 0/* real length varies */);
1014 static DEVICE_ATTR_RO(domains);
1015 
1016 static struct bin_attribute *if_bin_attrs[] = {
1017         &bin_attr_catalog,
1018         NULL,
1019 };
1020 
1021 static struct attribute *if_attrs[] = {
1022         &dev_attr_catalog_len.attr,
1023         &dev_attr_catalog_version.attr,
1024         &dev_attr_domains.attr,
1025         NULL,
1026 };
1027 
1028 static struct attribute_group if_group = {
1029         .name = "interface",
1030         .bin_attrs = if_bin_attrs,
1031         .attrs = if_attrs,
1032 };
1033 
1034 static const struct attribute_group *attr_groups[] = {
1035         &format_group,
1036         &event_group,
1037         &event_desc_group,
1038         &event_long_desc_group,
1039         &if_group,
1040         NULL,
1041 };
1042 
1043 static void log_24x7_hcall(struct hv_24x7_request_buffer *request_buffer,
1044                            struct hv_24x7_data_result_buffer *result_buffer,
1045                            unsigned long ret)
1046 {
1047         struct hv_24x7_request *req;
1048 
1049         req = &request_buffer->requests[0];
1050         pr_notice_ratelimited("hcall failed: [%d %#x %#x %d] => "
1051                         "ret 0x%lx (%ld) detail=0x%x failing ix=%x\n",
1052                         req->performance_domain, req->data_offset,
1053                         req->starting_ix, req->starting_lpar_ix, ret, ret,
1054                         result_buffer->detailed_rc,
1055                         result_buffer->failing_request_ix);
1056 }
1057 
1058 /*
1059  * Start the process for a new H_GET_24x7_DATA hcall.
1060  */
1061 static void init_24x7_request(struct hv_24x7_request_buffer *request_buffer,
1062                               struct hv_24x7_data_result_buffer *result_buffer)
1063 {
1064 
1065         memset(request_buffer, 0, 4096);
1066         memset(result_buffer, 0, 4096);
1067 
1068         request_buffer->interface_version = HV_24X7_IF_VERSION_CURRENT;
1069         /* memset above set request_buffer->num_requests to 0 */
1070 }
1071 
1072 /*
1073  * Commit (i.e perform) the H_GET_24x7_DATA hcall using the data collected
1074  * by 'init_24x7_request()' and 'add_event_to_24x7_request()'.
1075  */
1076 static int make_24x7_request(struct hv_24x7_request_buffer *request_buffer,
1077                              struct hv_24x7_data_result_buffer *result_buffer)
1078 {
1079         unsigned long ret;
1080 
1081         /*
1082          * NOTE: Due to variable number of array elements in request and
1083          *       result buffer(s), sizeof() is not reliable. Use the actual
1084          *       allocated buffer size, H24x7_DATA_BUFFER_SIZE.
1085          */
1086         ret = plpar_hcall_norets(H_GET_24X7_DATA,
1087                         virt_to_phys(request_buffer), H24x7_DATA_BUFFER_SIZE,
1088                         virt_to_phys(result_buffer),  H24x7_DATA_BUFFER_SIZE);
1089 
1090         if (ret)
1091                 log_24x7_hcall(request_buffer, result_buffer, ret);
1092 
1093         return ret;
1094 }
1095 
1096 /*
1097  * Add the given @event to the next slot in the 24x7 request_buffer.
1098  *
1099  * Note that H_GET_24X7_DATA hcall allows reading several counters'
1100  * values in a single HCALL. We expect the caller to add events to the
1101  * request buffer one by one, make the HCALL and process the results.
1102  */
1103 static int add_event_to_24x7_request(struct perf_event *event,
1104                                 struct hv_24x7_request_buffer *request_buffer)
1105 {
1106         u16 idx;
1107         int i;
1108         struct hv_24x7_request *req;
1109 
1110         if (request_buffer->num_requests > 254) {
1111                 pr_devel("Too many requests for 24x7 HCALL %d\n",
1112                                 request_buffer->num_requests);
1113                 return -EINVAL;
1114         }
1115 
1116         switch (event_get_domain(event)) {
1117         case HV_PERF_DOMAIN_PHYS_CHIP:
1118                 idx = event_get_chip(event);
1119                 break;
1120         case HV_PERF_DOMAIN_PHYS_CORE:
1121                 idx = event_get_core(event);
1122                 break;
1123         default:
1124                 idx = event_get_vcpu(event);
1125         }
1126 
1127         i = request_buffer->num_requests++;
1128         req = &request_buffer->requests[i];
1129 
1130         req->performance_domain = event_get_domain(event);
1131         req->data_size = cpu_to_be16(8);
1132         req->data_offset = cpu_to_be32(event_get_offset(event));
1133         req->starting_lpar_ix = cpu_to_be16(event_get_lpar(event)),
1134         req->max_num_lpars = cpu_to_be16(1);
1135         req->starting_ix = cpu_to_be16(idx);
1136         req->max_ix = cpu_to_be16(1);
1137 
1138         return 0;
1139 }
1140 
1141 static unsigned long single_24x7_request(struct perf_event *event, u64 *count)
1142 {
1143         unsigned long ret;
1144         struct hv_24x7_request_buffer *request_buffer;
1145         struct hv_24x7_data_result_buffer *result_buffer;
1146 
1147         BUILD_BUG_ON(sizeof(*request_buffer) > 4096);
1148         BUILD_BUG_ON(sizeof(*result_buffer) > 4096);
1149 
1150         request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1151         result_buffer = (void *)get_cpu_var(hv_24x7_resb);
1152 
1153         init_24x7_request(request_buffer, result_buffer);
1154 
1155         ret = add_event_to_24x7_request(event, request_buffer);
1156         if (ret)
1157                 goto out;
1158 
1159         ret = make_24x7_request(request_buffer, result_buffer);
1160         if (ret) {
1161                 log_24x7_hcall(request_buffer, result_buffer, ret);
1162                 goto out;
1163         }
1164 
1165         /* process result from hcall */
1166         *count = be64_to_cpu(result_buffer->results[0].elements[0].element_data[0]);
1167 
1168 out:
1169         put_cpu_var(hv_24x7_reqb);
1170         put_cpu_var(hv_24x7_resb);
1171         return ret;
1172 }
1173 
1174 
1175 static int h_24x7_event_init(struct perf_event *event)
1176 {
1177         struct hv_perf_caps caps;
1178         unsigned domain;
1179         unsigned long hret;
1180         u64 ct;
1181 
1182         /* Not our event */
1183         if (event->attr.type != event->pmu->type)
1184                 return -ENOENT;
1185 
1186         /* Unused areas must be 0 */
1187         if (event_get_reserved1(event) ||
1188             event_get_reserved2(event) ||
1189             event_get_reserved3(event)) {
1190                 pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n",
1191                                 event->attr.config,
1192                                 event_get_reserved1(event),
1193                                 event->attr.config1,
1194                                 event_get_reserved2(event),
1195                                 event->attr.config2,
1196                                 event_get_reserved3(event));
1197                 return -EINVAL;
1198         }
1199 
1200         /* unsupported modes and filters */
1201         if (event->attr.exclude_user   ||
1202             event->attr.exclude_kernel ||
1203             event->attr.exclude_hv     ||
1204             event->attr.exclude_idle   ||
1205             event->attr.exclude_host   ||
1206             event->attr.exclude_guest)
1207                 return -EINVAL;
1208 
1209         /* no branch sampling */
1210         if (has_branch_stack(event))
1211                 return -EOPNOTSUPP;
1212 
1213         /* offset must be 8 byte aligned */
1214         if (event_get_offset(event) % 8) {
1215                 pr_devel("bad alignment\n");
1216                 return -EINVAL;
1217         }
1218 
1219         /* Domains above 6 are invalid */
1220         domain = event_get_domain(event);
1221         if (domain > 6) {
1222                 pr_devel("invalid domain %d\n", domain);
1223                 return -EINVAL;
1224         }
1225 
1226         hret = hv_perf_caps_get(&caps);
1227         if (hret) {
1228                 pr_devel("could not get capabilities: rc=%ld\n", hret);
1229                 return -EIO;
1230         }
1231 
1232         /* Physical domains & other lpars require extra capabilities */
1233         if (!caps.collect_privileged && (is_physical_domain(domain) ||
1234                 (event_get_lpar(event) != event_get_lpar_max()))) {
1235                 pr_devel("hv permissions disallow: is_physical_domain:%d, lpar=0x%llx\n",
1236                                 is_physical_domain(domain),
1237                                 event_get_lpar(event));
1238                 return -EACCES;
1239         }
1240 
1241         /* Get the initial value of the counter for this event */
1242         if (single_24x7_request(event, &ct)) {
1243                 pr_devel("test hcall failed\n");
1244                 return -EIO;
1245         }
1246         (void)local64_xchg(&event->hw.prev_count, ct);
1247 
1248         return 0;
1249 }
1250 
1251 static u64 h_24x7_get_value(struct perf_event *event)
1252 {
1253         unsigned long ret;
1254         u64 ct;
1255         ret = single_24x7_request(event, &ct);
1256         if (ret)
1257                 /* We checked this in event init, shouldn't fail here... */
1258                 return 0;
1259 
1260         return ct;
1261 }
1262 
1263 static void update_event_count(struct perf_event *event, u64 now)
1264 {
1265         s64 prev;
1266 
1267         prev = local64_xchg(&event->hw.prev_count, now);
1268         local64_add(now - prev, &event->count);
1269 }
1270 
1271 static void h_24x7_event_read(struct perf_event *event)
1272 {
1273         u64 now;
1274         struct hv_24x7_request_buffer *request_buffer;
1275         struct hv_24x7_hw *h24x7hw;
1276         int txn_flags;
1277 
1278         txn_flags = __this_cpu_read(hv_24x7_txn_flags);
1279 
1280         /*
1281          * If in a READ transaction, add this counter to the list of
1282          * counters to read during the next HCALL (i.e commit_txn()).
1283          * If not in a READ transaction, go ahead and make the HCALL
1284          * to read this counter by itself.
1285          */
1286 
1287         if (txn_flags & PERF_PMU_TXN_READ) {
1288                 int i;
1289                 int ret;
1290 
1291                 if (__this_cpu_read(hv_24x7_txn_err))
1292                         return;
1293 
1294                 request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1295 
1296                 ret = add_event_to_24x7_request(event, request_buffer);
1297                 if (ret) {
1298                         __this_cpu_write(hv_24x7_txn_err, ret);
1299                 } else {
1300                         /*
1301                          * Associate the event with the HCALL request index,
1302                          * so ->commit_txn() can quickly find/update count.
1303                          */
1304                         i = request_buffer->num_requests - 1;
1305 
1306                         h24x7hw = &get_cpu_var(hv_24x7_hw);
1307                         h24x7hw->events[i] = event;
1308                         put_cpu_var(h24x7hw);
1309                         /*
1310                          * Clear the event count so we can compute the _change_
1311                          * in the 24x7 raw counter value at the end of the txn.
1312                          *
1313                          * Note that we could alternatively read the 24x7 value
1314                          * now and save its value in event->hw.prev_count. But
1315                          * that would require issuing a hcall, which would then
1316                          * defeat the purpose of using the txn interface.
1317                          */
1318                         local64_set(&event->count, 0);
1319                 }
1320 
1321                 put_cpu_var(hv_24x7_reqb);
1322         } else {
1323                 now = h_24x7_get_value(event);
1324                 update_event_count(event, now);
1325         }
1326 }
1327 
1328 static void h_24x7_event_start(struct perf_event *event, int flags)
1329 {
1330         if (flags & PERF_EF_RELOAD)
1331                 local64_set(&event->hw.prev_count, h_24x7_get_value(event));
1332 }
1333 
1334 static void h_24x7_event_stop(struct perf_event *event, int flags)
1335 {
1336         h_24x7_event_read(event);
1337 }
1338 
1339 static int h_24x7_event_add(struct perf_event *event, int flags)
1340 {
1341         if (flags & PERF_EF_START)
1342                 h_24x7_event_start(event, flags);
1343 
1344         return 0;
1345 }
1346 
1347 /*
1348  * 24x7 counters only support READ transactions. They are
1349  * always counting and dont need/support ADD transactions.
1350  * Cache the flags, but otherwise ignore transactions that
1351  * are not PERF_PMU_TXN_READ.
1352  */
1353 static void h_24x7_event_start_txn(struct pmu *pmu, unsigned int flags)
1354 {
1355         struct hv_24x7_request_buffer *request_buffer;
1356         struct hv_24x7_data_result_buffer *result_buffer;
1357 
1358         /* We should not be called if we are already in a txn */
1359         WARN_ON_ONCE(__this_cpu_read(hv_24x7_txn_flags));
1360 
1361         __this_cpu_write(hv_24x7_txn_flags, flags);
1362         if (flags & ~PERF_PMU_TXN_READ)
1363                 return;
1364 
1365         request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1366         result_buffer = (void *)get_cpu_var(hv_24x7_resb);
1367 
1368         init_24x7_request(request_buffer, result_buffer);
1369 
1370         put_cpu_var(hv_24x7_resb);
1371         put_cpu_var(hv_24x7_reqb);
1372 }
1373 
1374 /*
1375  * Clean up transaction state.
1376  *
1377  * NOTE: Ignore state of request and result buffers for now.
1378  *       We will initialize them during the next read/txn.
1379  */
1380 static void reset_txn(void)
1381 {
1382         __this_cpu_write(hv_24x7_txn_flags, 0);
1383         __this_cpu_write(hv_24x7_txn_err, 0);
1384 }
1385 
1386 /*
1387  * 24x7 counters only support READ transactions. They are always counting
1388  * and dont need/support ADD transactions. Clear ->txn_flags but otherwise
1389  * ignore transactions that are not of type PERF_PMU_TXN_READ.
1390  *
1391  * For READ transactions, submit all pending 24x7 requests (i.e requests
1392  * that were queued by h_24x7_event_read()), to the hypervisor and update
1393  * the event counts.
1394  */
1395 static int h_24x7_event_commit_txn(struct pmu *pmu)
1396 {
1397         struct hv_24x7_request_buffer *request_buffer;
1398         struct hv_24x7_data_result_buffer *result_buffer;
1399         struct hv_24x7_result *resb;
1400         struct perf_event *event;
1401         u64 count;
1402         int i, ret, txn_flags;
1403         struct hv_24x7_hw *h24x7hw;
1404 
1405         txn_flags = __this_cpu_read(hv_24x7_txn_flags);
1406         WARN_ON_ONCE(!txn_flags);
1407 
1408         ret = 0;
1409         if (txn_flags & ~PERF_PMU_TXN_READ)
1410                 goto out;
1411 
1412         ret = __this_cpu_read(hv_24x7_txn_err);
1413         if (ret)
1414                 goto out;
1415 
1416         request_buffer = (void *)get_cpu_var(hv_24x7_reqb);
1417         result_buffer = (void *)get_cpu_var(hv_24x7_resb);
1418 
1419         ret = make_24x7_request(request_buffer, result_buffer);
1420         if (ret) {
1421                 log_24x7_hcall(request_buffer, result_buffer, ret);
1422                 goto put_reqb;
1423         }
1424 
1425         h24x7hw = &get_cpu_var(hv_24x7_hw);
1426 
1427         /* Update event counts from hcall */
1428         for (i = 0; i < request_buffer->num_requests; i++) {
1429                 resb = &result_buffer->results[i];
1430                 count = be64_to_cpu(resb->elements[0].element_data[0]);
1431                 event = h24x7hw->events[i];
1432                 h24x7hw->events[i] = NULL;
1433                 update_event_count(event, count);
1434         }
1435 
1436         put_cpu_var(hv_24x7_hw);
1437 
1438 put_reqb:
1439         put_cpu_var(hv_24x7_resb);
1440         put_cpu_var(hv_24x7_reqb);
1441 out:
1442         reset_txn();
1443         return ret;
1444 }
1445 
1446 /*
1447  * 24x7 counters only support READ transactions. They are always counting
1448  * and dont need/support ADD transactions. However, regardless of type
1449  * of transaction, all we need to do is cleanup, so we don't have to check
1450  * the type of transaction.
1451  */
1452 static void h_24x7_event_cancel_txn(struct pmu *pmu)
1453 {
1454         WARN_ON_ONCE(!__this_cpu_read(hv_24x7_txn_flags));
1455         reset_txn();
1456 }
1457 
1458 static struct pmu h_24x7_pmu = {
1459         .task_ctx_nr = perf_invalid_context,
1460 
1461         .name = "hv_24x7",
1462         .attr_groups = attr_groups,
1463         .event_init  = h_24x7_event_init,
1464         .add         = h_24x7_event_add,
1465         .del         = h_24x7_event_stop,
1466         .start       = h_24x7_event_start,
1467         .stop        = h_24x7_event_stop,
1468         .read        = h_24x7_event_read,
1469         .start_txn   = h_24x7_event_start_txn,
1470         .commit_txn  = h_24x7_event_commit_txn,
1471         .cancel_txn  = h_24x7_event_cancel_txn,
1472 };
1473 
1474 static int hv_24x7_init(void)
1475 {
1476         int r;
1477         unsigned long hret;
1478         struct hv_perf_caps caps;
1479 
1480         if (!firmware_has_feature(FW_FEATURE_LPAR)) {
1481                 pr_debug("not a virtualized system, not enabling\n");
1482                 return -ENODEV;
1483         }
1484 
1485         hret = hv_perf_caps_get(&caps);
1486         if (hret) {
1487                 pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
1488                                 hret);
1489                 return -ENODEV;
1490         }
1491 
1492         hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL);
1493         if (!hv_page_cache)
1494                 return -ENOMEM;
1495 
1496         /* sampling not supported */
1497         h_24x7_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
1498 
1499         r = create_events_from_catalog(&event_group.attrs,
1500                                    &event_desc_group.attrs,
1501                                    &event_long_desc_group.attrs);
1502 
1503         if (r)
1504                 return r;
1505 
1506         r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
1507         if (r)
1508                 return r;
1509 
1510         return 0;
1511 }
1512 
1513 device_initcall(hv_24x7_init);
1514 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp