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Linux 3.16-rc2
[linux/fpc-iii.git] / arch / powerpc / perf / hv-24x7.c
blobe0766b82e1656721ff9e93586b47552414936973
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/module.h>
17 #include <linux/slab.h>
18 #include <asm/firmware.h>
19 #include <asm/hvcall.h>
20 #include <asm/io.h>
21
22 #include "hv-24x7.h"
23 #include "hv-24x7-catalog.h"
24 #include "hv-common.h"
25
26 /*
27 * TODO: Merging events:
28 * - Think of the hcall as an interface to a 4d array of counters:
29 * - x = domains
30 * - y = indexes in the domain (core, chip, vcpu, node, etc)
31 * - z = offset into the counter space
32 * - w = lpars (guest vms, "logical partitions")
33 * - A single request is: x,y,y_last,z,z_last,w,w_last
34 * - this means we can retrieve a rectangle of counters in y,z for a single x.
35 *
36 * - Things to consider (ignoring w):
37 * - input cost_per_request = 16
38 * - output cost_per_result(ys,zs) = 8 + 8 * ys + ys * zs
39 * - limited number of requests per hcall (must fit into 4K bytes)
40 * - 4k = 16 [buffer header] - 16 [request size] * request_count
41 * - 255 requests per hcall
42 * - sometimes it will be more efficient to read extra data and discard
43 */
44
45 /*
46 * Example usage:
47 * perf stat -e 'hv_24x7/domain=2,offset=8,starting_index=0,lpar=0xffffffff/'
48 */
49
50 /* u3 0-6, one of HV_24X7_PERF_DOMAIN */
51 EVENT_DEFINE_RANGE_FORMAT(domain, config, 0, 3);
52 /* u16 */
53 EVENT_DEFINE_RANGE_FORMAT(starting_index, config, 16, 31);
54 /* u32, see "data_offset" */
55 EVENT_DEFINE_RANGE_FORMAT(offset, config, 32, 63);
56 /* u16 */
57 EVENT_DEFINE_RANGE_FORMAT(lpar, config1, 0, 15);
58
59 EVENT_DEFINE_RANGE(reserved1, config, 4, 15);
60 EVENT_DEFINE_RANGE(reserved2, config1, 16, 63);
61 EVENT_DEFINE_RANGE(reserved3, config2, 0, 63);
62
63 static struct attribute *format_attrs[] = {
64 &format_attr_domain.attr,
65 &format_attr_offset.attr,
66 &format_attr_starting_index.attr,
67 &format_attr_lpar.attr,
68 NULL,
69 };
70
71 static struct attribute_group format_group = {
72 .name = "format",
73 .attrs = format_attrs,
74 };
75
76 static struct kmem_cache *hv_page_cache;
77
78 /*
79 * read_offset_data - copy data from one buffer to another while treating the
80 * source buffer as a small view on the total avaliable
81 * source data.
82 *
83 * @dest: buffer to copy into
84 * @dest_len: length of @dest in bytes
85 * @requested_offset: the offset within the source data we want. Must be > 0
86 * @src: buffer to copy data from
87 * @src_len: length of @src in bytes
88 * @source_offset: the offset in the sorce data that (src,src_len) refers to.
89 * Must be > 0
90 *
91 * returns the number of bytes copied.
92 *
93 * The following ascii art shows the various buffer possitioning we need to
94 * handle, assigns some arbitrary varibles to points on the buffer, and then
95 * shows how we fiddle with those values to get things we care about (copy
96 * start in src and copy len)
97 *
98 * s = @src buffer
99 * d = @dest buffer
100 * '.' areas in d are written to.
101 *
102 * u
103 * x w v z
104 * d |.........|
105 * s |----------------------|
106 *
107 * u
108 * x w z v
109 * d |........------|
110 * s |------------------|
111 *
112 * x w u,z,v
113 * d |........|
114 * s |------------------|
115 *
116 * x,w u,v,z
117 * d |..................|
118 * s |------------------|
119 *
120 * x u
121 * w v z
122 * d |........|
123 * s |------------------|
124 *
125 * x z w v
126 * d |------|
127 * s |------|
128 *
129 * x = source_offset
130 * w = requested_offset
131 * z = source_offset + src_len
132 * v = requested_offset + dest_len
133 *
134 * w_offset_in_s = w - x = requested_offset - source_offset
135 * z_offset_in_s = z - x = src_len
136 * v_offset_in_s = v - x = request_offset + dest_len - src_len
137 */
138 static ssize_t read_offset_data(void *dest, size_t dest_len,
139 loff_t requested_offset, void *src,
140 size_t src_len, loff_t source_offset)
141 {
142 size_t w_offset_in_s = requested_offset - source_offset;
143 size_t z_offset_in_s = src_len;
144 size_t v_offset_in_s = requested_offset + dest_len - src_len;
145 size_t u_offset_in_s = min(z_offset_in_s, v_offset_in_s);
146 size_t copy_len = u_offset_in_s - w_offset_in_s;
147
148 if (requested_offset < 0 || source_offset < 0)
149 return -EINVAL;
150
151 if (z_offset_in_s <= w_offset_in_s)
152 return 0;
153
154 memcpy(dest, src + w_offset_in_s, copy_len);
155 return copy_len;
156 }
157
158 static unsigned long h_get_24x7_catalog_page_(unsigned long phys_4096,
159 unsigned long version,
160 unsigned long index)
161 {
162 pr_devel("h_get_24x7_catalog_page(0x%lx, %lu, %lu)",
163 phys_4096,
164 version,
165 index);
166 WARN_ON(!IS_ALIGNED(phys_4096, 4096));
167 return plpar_hcall_norets(H_GET_24X7_CATALOG_PAGE,
168 phys_4096,
169 version,
170 index);
171 }
172
173 static unsigned long h_get_24x7_catalog_page(char page[],
174 u64 version, u32 index)
175 {
176 return h_get_24x7_catalog_page_(virt_to_phys(page),
177 version, index);
178 }
179
180 static ssize_t catalog_read(struct file *filp, struct kobject *kobj,
181 struct bin_attribute *bin_attr, char *buf,
182 loff_t offset, size_t count)
183 {
184 unsigned long hret;
185 ssize_t ret = 0;
186 size_t catalog_len = 0, catalog_page_len = 0, page_count = 0;
187 loff_t page_offset = 0;
188 uint64_t catalog_version_num = 0;
189 void *page = kmem_cache_alloc(hv_page_cache, GFP_USER);
190 struct hv_24x7_catalog_page_0 *page_0 = page;
191 if (!page)
192 return -ENOMEM;
193
194 hret = h_get_24x7_catalog_page(page, 0, 0);
195 if (hret) {
196 ret = -EIO;
197 goto e_free;
198 }
199
200 catalog_version_num = be64_to_cpu(page_0->version);
201 catalog_page_len = be32_to_cpu(page_0->length);
202 catalog_len = catalog_page_len * 4096;
203
204 page_offset = offset / 4096;
205 page_count = count / 4096;
206
207 if (page_offset >= catalog_page_len)
208 goto e_free;
209
210 if (page_offset != 0) {
211 hret = h_get_24x7_catalog_page(page, catalog_version_num,
212 page_offset);
213 if (hret) {
214 ret = -EIO;
215 goto e_free;
216 }
217 }
218
219 ret = read_offset_data(buf, count, offset,
220 page, 4096, page_offset * 4096);
221 e_free:
222 if (hret)
223 pr_err("h_get_24x7_catalog_page(ver=%lld, page=%lld) failed:"
224 " rc=%ld\n",
225 catalog_version_num, page_offset, hret);
226 kfree(page);
227
228 pr_devel("catalog_read: offset=%lld(%lld) count=%zu(%zu) catalog_len=%zu(%zu) => %zd\n",
229 offset, page_offset, count, page_count, catalog_len,
230 catalog_page_len, ret);
231
232 return ret;
233 }
234
235 #define PAGE_0_ATTR(_name, _fmt, _expr) \
236 static ssize_t _name##_show(struct device *dev, \
237 struct device_attribute *dev_attr, \
238 char *buf) \
239 { \
240 unsigned long hret; \
241 ssize_t ret = 0; \
242 void *page = kmem_cache_alloc(hv_page_cache, GFP_USER); \
243 struct hv_24x7_catalog_page_0 *page_0 = page; \
244 if (!page) \
245 return -ENOMEM; \
246 hret = h_get_24x7_catalog_page(page, 0, 0); \
247 if (hret) { \
248 ret = -EIO; \
249 goto e_free; \
250 } \
251 ret = sprintf(buf, _fmt, _expr); \
252 e_free: \
253 kfree(page); \
254 return ret; \
255 } \
256 static DEVICE_ATTR_RO(_name)
257
258 PAGE_0_ATTR(catalog_version, "%lld\n",
259 (unsigned long long)be64_to_cpu(page_0->version));
260 PAGE_0_ATTR(catalog_len, "%lld\n",
261 (unsigned long long)be32_to_cpu(page_0->length) * 4096);
262 static BIN_ATTR_RO(catalog, 0/* real length varies */);
263
264 static struct bin_attribute *if_bin_attrs[] = {
265 &bin_attr_catalog,
266 NULL,
267 };
268
269 static struct attribute *if_attrs[] = {
270 &dev_attr_catalog_len.attr,
271 &dev_attr_catalog_version.attr,
272 NULL,
273 };
274
275 static struct attribute_group if_group = {
276 .name = "interface",
277 .bin_attrs = if_bin_attrs,
278 .attrs = if_attrs,
279 };
280
281 static const struct attribute_group *attr_groups[] = {
282 &format_group,
283 &if_group,
284 NULL,
285 };
286
287 static bool is_physical_domain(int domain)
288 {
289 return domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CHIP ||
290 domain == HV_24X7_PERF_DOMAIN_PHYSICAL_CORE;
291 }
292
293 static unsigned long single_24x7_request(u8 domain, u32 offset, u16 ix,
294 u16 lpar, u64 *res,
295 bool success_expected)
296 {
297 unsigned long ret;
298
299 /*
300 * request_buffer and result_buffer are not required to be 4k aligned,
301 * but are not allowed to cross any 4k boundary. Aligning them to 4k is
302 * the simplest way to ensure that.
303 */
304 struct reqb {
305 struct hv_24x7_request_buffer buf;
306 struct hv_24x7_request req;
307 } __packed __aligned(4096) request_buffer = {
308 .buf = {
309 .interface_version = HV_24X7_IF_VERSION_CURRENT,
310 .num_requests = 1,
311 },
312 .req = {
313 .performance_domain = domain,
314 .data_size = cpu_to_be16(8),
315 .data_offset = cpu_to_be32(offset),
316 .starting_lpar_ix = cpu_to_be16(lpar),
317 .max_num_lpars = cpu_to_be16(1),
318 .starting_ix = cpu_to_be16(ix),
319 .max_ix = cpu_to_be16(1),
320 }
321 };
322
323 struct resb {
324 struct hv_24x7_data_result_buffer buf;
325 struct hv_24x7_result res;
326 struct hv_24x7_result_element elem;
327 __be64 result;
328 } __packed __aligned(4096) result_buffer = {};
329
330 ret = plpar_hcall_norets(H_GET_24X7_DATA,
331 virt_to_phys(&request_buffer), sizeof(request_buffer),
332 virt_to_phys(&result_buffer), sizeof(result_buffer));
333
334 if (ret) {
335 if (success_expected)
336 pr_err_ratelimited("hcall failed: %d %#x %#x %d => 0x%lx (%ld) detail=0x%x failing ix=%x\n",
337 domain, offset, ix, lpar,
338 ret, ret,
339 result_buffer.buf.detailed_rc,
340 result_buffer.buf.failing_request_ix);
341 return ret;
342 }
343
344 *res = be64_to_cpu(result_buffer.result);
345 return ret;
346 }
347
348 static unsigned long event_24x7_request(struct perf_event *event, u64 *res,
349 bool success_expected)
350 {
351 return single_24x7_request(event_get_domain(event),
352 event_get_offset(event),
353 event_get_starting_index(event),
354 event_get_lpar(event),
355 res,
356 success_expected);
357 }
358
359 static int h_24x7_event_init(struct perf_event *event)
360 {
361 struct hv_perf_caps caps;
362 unsigned domain;
363 unsigned long hret;
364 u64 ct;
365
366 /* Not our event */
367 if (event->attr.type != event->pmu->type)
368 return -ENOENT;
369
370 /* Unused areas must be 0 */
371 if (event_get_reserved1(event) ||
372 event_get_reserved2(event) ||
373 event_get_reserved3(event)) {
374 pr_devel("reserved set when forbidden 0x%llx(0x%llx) 0x%llx(0x%llx) 0x%llx(0x%llx)\n",
375 event->attr.config,
376 event_get_reserved1(event),
377 event->attr.config1,
378 event_get_reserved2(event),
379 event->attr.config2,
380 event_get_reserved3(event));
381 return -EINVAL;
382 }
383
384 /* unsupported modes and filters */
385 if (event->attr.exclude_user ||
386 event->attr.exclude_kernel ||
387 event->attr.exclude_hv ||
388 event->attr.exclude_idle ||
389 event->attr.exclude_host ||
390 event->attr.exclude_guest ||
391 is_sampling_event(event)) /* no sampling */
392 return -EINVAL;
393
394 /* no branch sampling */
395 if (has_branch_stack(event))
396 return -EOPNOTSUPP;
397
398 /* offset must be 8 byte aligned */
399 if (event_get_offset(event) % 8) {
400 pr_devel("bad alignment\n");
401 return -EINVAL;
402 }
403
404 /* Domains above 6 are invalid */
405 domain = event_get_domain(event);
406 if (domain > 6) {
407 pr_devel("invalid domain %d\n", domain);
408 return -EINVAL;
409 }
410
411 hret = hv_perf_caps_get(&caps);
412 if (hret) {
413 pr_devel("could not get capabilities: rc=%ld\n", hret);
414 return -EIO;
415 }
416
417 /* PHYSICAL domains & other lpars require extra capabilities */
418 if (!caps.collect_privileged && (is_physical_domain(domain) ||
419 (event_get_lpar(event) != event_get_lpar_max()))) {
420 pr_devel("hv permisions disallow: is_physical_domain:%d, lpar=0x%llx\n",
421 is_physical_domain(domain),
422 event_get_lpar(event));
423 return -EACCES;
424 }
425
426 /* see if the event complains */
427 if (event_24x7_request(event, &ct, false)) {
428 pr_devel("test hcall failed\n");
429 return -EIO;
430 }
431
432 return 0;
433 }
434
435 static u64 h_24x7_get_value(struct perf_event *event)
436 {
437 unsigned long ret;
438 u64 ct;
439 ret = event_24x7_request(event, &ct, true);
440 if (ret)
441 /* We checked this in event init, shouldn't fail here... */
442 return 0;
443
444 return ct;
445 }
446
447 static void h_24x7_event_update(struct perf_event *event)
448 {
449 s64 prev;
450 u64 now;
451 now = h_24x7_get_value(event);
452 prev = local64_xchg(&event->hw.prev_count, now);
453 local64_add(now - prev, &event->count);
454 }
455
456 static void h_24x7_event_start(struct perf_event *event, int flags)
457 {
458 if (flags & PERF_EF_RELOAD)
459 local64_set(&event->hw.prev_count, h_24x7_get_value(event));
460 }
461
462 static void h_24x7_event_stop(struct perf_event *event, int flags)
463 {
464 h_24x7_event_update(event);
465 }
466
467 static int h_24x7_event_add(struct perf_event *event, int flags)
468 {
469 if (flags & PERF_EF_START)
470 h_24x7_event_start(event, flags);
471
472 return 0;
473 }
474
475 static int h_24x7_event_idx(struct perf_event *event)
476 {
477 return 0;
478 }
479
480 static struct pmu h_24x7_pmu = {
481 .task_ctx_nr = perf_invalid_context,
482
483 .name = "hv_24x7",
484 .attr_groups = attr_groups,
485 .event_init = h_24x7_event_init,
486 .add = h_24x7_event_add,
487 .del = h_24x7_event_stop,
488 .start = h_24x7_event_start,
489 .stop = h_24x7_event_stop,
490 .read = h_24x7_event_update,
491 .event_idx = h_24x7_event_idx,
492 };
493
494 static int hv_24x7_init(void)
495 {
496 int r;
497 unsigned long hret;
498 struct hv_perf_caps caps;
499
500 if (!firmware_has_feature(FW_FEATURE_LPAR)) {
501 pr_debug("not a virtualized system, not enabling\n");
502 return -ENODEV;
503 }
504
505 hret = hv_perf_caps_get(&caps);
506 if (hret) {
507 pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
508 hret);
509 return -ENODEV;
510 }
511
512 hv_page_cache = kmem_cache_create("hv-page-4096", 4096, 4096, 0, NULL);
513 if (!hv_page_cache)
514 return -ENOMEM;
515
516 r = perf_pmu_register(&h_24x7_pmu, h_24x7_pmu.name, -1);
517 if (r)
518 return r;
519
520 return 0;
521 }
522
523 device_initcall(hv_24x7_init);
Linux with added FPC-III support