1// SPDX-License-Identifier: GPL-2.0-or-later
   2/*
   3 * Hypervisor supplied "gpci" ("get performance counter info") performance
   4 * counter support
   5 *
   6 * Author: Cody P Schafer <cody@linux.vnet.ibm.com>
   7 * Copyright 2014 IBM Corporation.
   8 */
   9
  10#define pr_fmt(fmt) "hv-gpci: " fmt
  11
  12#include <linux/init.h>
  13#include <linux/perf_event.h>
  14#include <asm/firmware.h>
  15#include <asm/hvcall.h>
  16#include <asm/io.h>
  17
  18#include "hv-gpci.h"
  19#include "hv-common.h"
  20
  21/*
  22 * Example usage:
  23 *  perf stat -e 'hv_gpci/counter_info_version=3,offset=0,length=8,
  24 *		  secondary_index=0,starting_index=0xffffffff,request=0x10/' ...
  25 */
  26
  27/* u32 */
  28EVENT_DEFINE_RANGE_FORMAT(request, config, 0, 31);
  29/* u32 */
  30/*
  31 * Note that starting_index, phys_processor_idx, sibling_part_id,
  32 * hw_chip_id, partition_id all refer to the same bit range. They
  33 * are basically aliases for the starting_index. The specific alias
  34 * used depends on the event. See REQUEST_IDX_KIND in hv-gpci-requests.h
  35 */
  36EVENT_DEFINE_RANGE_FORMAT(starting_index, config, 32, 63);
  37EVENT_DEFINE_RANGE_FORMAT_LITE(phys_processor_idx, config, 32, 63);
  38EVENT_DEFINE_RANGE_FORMAT_LITE(sibling_part_id, config, 32, 63);
  39EVENT_DEFINE_RANGE_FORMAT_LITE(hw_chip_id, config, 32, 63);
  40EVENT_DEFINE_RANGE_FORMAT_LITE(partition_id, config, 32, 63);
  41
  42/* u16 */
  43EVENT_DEFINE_RANGE_FORMAT(secondary_index, config1, 0, 15);
  44/* u8 */
  45EVENT_DEFINE_RANGE_FORMAT(counter_info_version, config1, 16, 23);
  46/* u8, bytes of data (1-8) */
  47EVENT_DEFINE_RANGE_FORMAT(length, config1, 24, 31);
  48/* u32, byte offset */
  49EVENT_DEFINE_RANGE_FORMAT(offset, config1, 32, 63);
  50
  51static cpumask_t hv_gpci_cpumask;
  52
  53static struct attribute *format_attrs[] = {
  54	&format_attr_request.attr,
  55	&format_attr_starting_index.attr,
  56	&format_attr_phys_processor_idx.attr,
  57	&format_attr_sibling_part_id.attr,
  58	&format_attr_hw_chip_id.attr,
  59	&format_attr_partition_id.attr,
  60	&format_attr_secondary_index.attr,
  61	&format_attr_counter_info_version.attr,
  62
  63	&format_attr_offset.attr,
  64	&format_attr_length.attr,
  65	NULL,
  66};
  67
  68static const struct attribute_group format_group = {
  69	.name = "format",
  70	.attrs = format_attrs,
  71};
  72
  73static struct attribute_group event_group = {
  74	.name  = "events",
  75	/* .attrs is set in init */
  76};
  77
  78#define HV_CAPS_ATTR(_name, _format)				\
  79static ssize_t _name##_show(struct device *dev,			\
  80			    struct device_attribute *attr,	\
  81			    char *page)				\
  82{								\
  83	struct hv_perf_caps caps;				\
  84	unsigned long hret = hv_perf_caps_get(&caps);		\
  85	if (hret)						\
  86		return -EIO;					\
  87								\
  88	return sprintf(page, _format, caps._name);		\
  89}								\
  90static struct device_attribute hv_caps_attr_##_name = __ATTR_RO(_name)
  91
  92static ssize_t kernel_version_show(struct device *dev,
  93				   struct device_attribute *attr,
  94				   char *page)
  95{
  96	return sprintf(page, "0x%x\n", COUNTER_INFO_VERSION_CURRENT);
  97}
  98
  99static ssize_t cpumask_show(struct device *dev,
 100			    struct device_attribute *attr, char *buf)
 101{
 102	return cpumap_print_to_pagebuf(true, buf, &hv_gpci_cpumask);
 103}
 104
 105/* Interface attribute array index to store system information */
 106#define INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR	6
 107#define INTERFACE_PROCESSOR_CONFIG_ATTR		7
 108#define INTERFACE_AFFINITY_DOMAIN_VIA_VP_ATTR	8
 109#define INTERFACE_AFFINITY_DOMAIN_VIA_DOM_ATTR	9
 110#define INTERFACE_AFFINITY_DOMAIN_VIA_PAR_ATTR	10
 111#define INTERFACE_NULL_ATTR			11
 112
 113/* Counter request value to retrieve system information */
 114enum {
 115	PROCESSOR_BUS_TOPOLOGY,
 116	PROCESSOR_CONFIG,
 117	AFFINITY_DOMAIN_VIA_VP, /* affinity domain via virtual processor */
 118	AFFINITY_DOMAIN_VIA_DOM, /* affinity domain via domain */
 119	AFFINITY_DOMAIN_VIA_PAR, /* affinity domain via partition */
 120};
 121
 122static int sysinfo_counter_request[] = {
 123	[PROCESSOR_BUS_TOPOLOGY] = 0xD0,
 124	[PROCESSOR_CONFIG] = 0x90,
 125	[AFFINITY_DOMAIN_VIA_VP] = 0xA0,
 126	[AFFINITY_DOMAIN_VIA_DOM] = 0xB0,
 127	[AFFINITY_DOMAIN_VIA_PAR] = 0xB1,
 128};
 129
 130static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE]) __aligned(sizeof(uint64_t));
 131
 132static unsigned long systeminfo_gpci_request(u32 req, u32 starting_index,
 133			u16 secondary_index, char *buf,
 134			size_t *n, struct hv_gpci_request_buffer *arg)
 135{
 136	unsigned long ret;
 137	size_t i, j;
 138
 139	arg->params.counter_request = cpu_to_be32(req);
 140	arg->params.starting_index = cpu_to_be32(starting_index);
 141	arg->params.secondary_index = cpu_to_be16(secondary_index);
 142
 143	ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
 144			virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
 145
 146	/*
 147	 * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL',
 148	 * which means that the current buffer size cannot accommodate
 149	 * all the information and a partial buffer returned.
 150	 * hcall fails incase of ret value other than H_SUCCESS or H_PARAMETER.
 151	 *
 152	 * ret value as H_AUTHORITY implies that partition is not permitted to retrieve
 153	 * performance information, and required to set
 154	 * "Enable Performance Information Collection" option.
 155	 */
 156	if (ret == H_AUTHORITY)
 157		return -EPERM;
 158
 159	/*
 160	 * hcall can fail with other possible ret value like H_PRIVILEGE/H_HARDWARE
 161	 * because of invalid buffer-length/address or due to some hardware
 162	 * error.
 163	 */
 164	if (ret && (ret != H_PARAMETER))
 165		return -EIO;
 166
 167	/*
 168	 * hcall H_GET_PERF_COUNTER_INFO populates the 'returned_values'
 169	 * to show the total number of counter_value array elements
 170	 * returned via hcall.
 171	 * hcall also populates 'cv_element_size' corresponds to individual
 172	 * counter_value array element size. Below loop go through all
 173	 * counter_value array elements as per their size and add it to
 174	 * the output buffer.
 175	 */
 176	for (i = 0; i < be16_to_cpu(arg->params.returned_values); i++) {
 177		j = i * be16_to_cpu(arg->params.cv_element_size);
 178
 179		for (; j < (i + 1) * be16_to_cpu(arg->params.cv_element_size); j++)
 180			*n += sprintf(buf + *n,  "%02x", (u8)arg->bytes[j]);
 181		*n += sprintf(buf + *n,  "\n");
 182	}
 183
 184	if (*n >= PAGE_SIZE) {
 185		pr_info("System information exceeds PAGE_SIZE\n");
 186		return -EFBIG;
 187	}
 188
 189	return ret;
 190}
 191
 192static ssize_t processor_bus_topology_show(struct device *dev, struct device_attribute *attr,
 193				char *buf)
 194{
 195	struct hv_gpci_request_buffer *arg;
 196	unsigned long ret;
 197	size_t n = 0;
 198
 199	arg = (void *)get_cpu_var(hv_gpci_reqb);
 200	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 201
 202	/*
 203	 * Pass the counter request value 0xD0 corresponds to request
 204	 * type 'Processor_bus_topology', to retrieve
 205	 * the system topology information.
 206	 * starting_index value implies the starting hardware
 207	 * chip id.
 208	 */
 209	ret = systeminfo_gpci_request(sysinfo_counter_request[PROCESSOR_BUS_TOPOLOGY],
 210			0, 0, buf, &n, arg);
 211
 212	if (!ret)
 213		return n;
 214
 215	if (ret != H_PARAMETER)
 216		goto out;
 217
 218	/*
 219	 * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL', which
 220	 * implies that buffer can't accommodate all information, and a partial buffer
 221	 * returned. To handle that, we need to make subsequent requests
 222	 * with next starting index to retrieve additional (missing) data.
 223	 * Below loop do subsequent hcalls with next starting index and add it
 224	 * to buffer util we get all the information.
 225	 */
 226	while (ret == H_PARAMETER) {
 227		int returned_values = be16_to_cpu(arg->params.returned_values);
 228		int elementsize = be16_to_cpu(arg->params.cv_element_size);
 229		int last_element = (returned_values - 1) * elementsize;
 230
 231		/*
 232		 * Since the starting index value is part of counter_value
 233		 * buffer elements, use the starting index value in the last
 234		 * element and add 1 to make subsequent hcalls.
 235		 */
 236		u32 starting_index = arg->bytes[last_element + 3] +
 237				(arg->bytes[last_element + 2] << 8) +
 238				(arg->bytes[last_element + 1] << 16) +
 239				(arg->bytes[last_element] << 24) + 1;
 240
 241		memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 242
 243		ret = systeminfo_gpci_request(sysinfo_counter_request[PROCESSOR_BUS_TOPOLOGY],
 244				starting_index, 0, buf, &n, arg);
 245
 246		if (!ret)
 247			return n;
 248
 249		if (ret != H_PARAMETER)
 250			goto out;
 251	}
 252
 253	return n;
 254
 255out:
 256	put_cpu_var(hv_gpci_reqb);
 257	return ret;
 258}
 259
 260static ssize_t processor_config_show(struct device *dev, struct device_attribute *attr,
 261					char *buf)
 262{
 263	struct hv_gpci_request_buffer *arg;
 264	unsigned long ret;
 265	size_t n = 0;
 266
 267	arg = (void *)get_cpu_var(hv_gpci_reqb);
 268	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 269
 270	/*
 271	 * Pass the counter request value 0x90 corresponds to request
 272	 * type 'Processor_config', to retrieve
 273	 * the system processor information.
 274	 * starting_index value implies the starting hardware
 275	 * processor index.
 276	 */
 277	ret = systeminfo_gpci_request(sysinfo_counter_request[PROCESSOR_CONFIG],
 278			0, 0, buf, &n, arg);
 279
 280	if (!ret)
 281		return n;
 282
 283	if (ret != H_PARAMETER)
 284		goto out;
 285
 286	/*
 287	 * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL', which
 288	 * implies that buffer can't accommodate all information, and a partial buffer
 289	 * returned. To handle that, we need to take subsequent requests
 290	 * with next starting index to retrieve additional (missing) data.
 291	 * Below loop do subsequent hcalls with next starting index and add it
 292	 * to buffer util we get all the information.
 293	 */
 294	while (ret == H_PARAMETER) {
 295		int returned_values = be16_to_cpu(arg->params.returned_values);
 296		int elementsize = be16_to_cpu(arg->params.cv_element_size);
 297		int last_element = (returned_values - 1) * elementsize;
 298
 299		/*
 300		 * Since the starting index is part of counter_value
 301		 * buffer elements, use the starting index value in the last
 302		 * element and add 1 to subsequent hcalls.
 303		 */
 304		u32 starting_index = arg->bytes[last_element + 3] +
 305				(arg->bytes[last_element + 2] << 8) +
 306				(arg->bytes[last_element + 1] << 16) +
 307				(arg->bytes[last_element] << 24) + 1;
 308
 309		memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 310
 311		ret = systeminfo_gpci_request(sysinfo_counter_request[PROCESSOR_CONFIG],
 312				starting_index, 0, buf, &n, arg);
 313
 314		if (!ret)
 315			return n;
 316
 317		if (ret != H_PARAMETER)
 318			goto out;
 319	}
 320
 321	return n;
 322
 323out:
 324	put_cpu_var(hv_gpci_reqb);
 325	return ret;
 326}
 327
 328static ssize_t affinity_domain_via_virtual_processor_show(struct device *dev,
 329			struct device_attribute *attr, char *buf)
 330{
 331	struct hv_gpci_request_buffer *arg;
 332	unsigned long ret;
 333	size_t n = 0;
 334
 335	arg = (void *)get_cpu_var(hv_gpci_reqb);
 336	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 337
 338	/*
 339	 * Pass the counter request 0xA0 corresponds to request
 340	 * type 'Affinity_domain_information_by_virutal_processor',
 341	 * to retrieve the system affinity domain information.
 342	 * starting_index value refers to the starting hardware
 343	 * processor index.
 344	 */
 345	ret = systeminfo_gpci_request(sysinfo_counter_request[AFFINITY_DOMAIN_VIA_VP],
 346			0, 0, buf, &n, arg);
 347
 348	if (!ret)
 349		return n;
 350
 351	if (ret != H_PARAMETER)
 352		goto out;
 353
 354	/*
 355	 * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL', which
 356	 * implies that buffer can't accommodate all information, and a partial buffer
 357	 * returned. To handle that, we need to take subsequent requests
 358	 * with next secondary index to retrieve additional (missing) data.
 359	 * Below loop do subsequent hcalls with next secondary index and add it
 360	 * to buffer util we get all the information.
 361	 */
 362	while (ret == H_PARAMETER) {
 363		int returned_values = be16_to_cpu(arg->params.returned_values);
 364		int elementsize = be16_to_cpu(arg->params.cv_element_size);
 365		int last_element = (returned_values - 1) * elementsize;
 366
 367		/*
 368		 * Since the starting index and secondary index type is part of the
 369		 * counter_value buffer elements, use the starting index value in the
 370		 * last array element as subsequent starting index, and use secondary index
 371		 * value in the last array element plus 1 as subsequent secondary index.
 372		 * For counter request '0xA0', starting index points to partition id
 373		 * and secondary index points to corresponding virtual processor index.
 374		 */
 375		u32 starting_index = arg->bytes[last_element + 1] + (arg->bytes[last_element] << 8);
 376		u16 secondary_index = arg->bytes[last_element + 3] +
 377				(arg->bytes[last_element + 2] << 8) + 1;
 378
 379		memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 380
 381		ret = systeminfo_gpci_request(sysinfo_counter_request[AFFINITY_DOMAIN_VIA_VP],
 382				starting_index, secondary_index, buf, &n, arg);
 383
 384		if (!ret)
 385			return n;
 386
 387		if (ret != H_PARAMETER)
 388			goto out;
 389	}
 390
 391	return n;
 392
 393out:
 394	put_cpu_var(hv_gpci_reqb);
 395	return ret;
 396}
 397
 398static ssize_t affinity_domain_via_domain_show(struct device *dev, struct device_attribute *attr,
 399						char *buf)
 400{
 401	struct hv_gpci_request_buffer *arg;
 402	unsigned long ret;
 403	size_t n = 0;
 404
 405	arg = (void *)get_cpu_var(hv_gpci_reqb);
 406	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 407
 408	/*
 409	 * Pass the counter request 0xB0 corresponds to request
 410	 * type 'Affinity_domain_information_by_domain',
 411	 * to retrieve the system affinity domain information.
 412	 * starting_index value refers to the starting hardware
 413	 * processor index.
 414	 */
 415	ret = systeminfo_gpci_request(sysinfo_counter_request[AFFINITY_DOMAIN_VIA_DOM],
 416			0, 0, buf, &n, arg);
 417
 418	if (!ret)
 419		return n;
 420
 421	if (ret != H_PARAMETER)
 422		goto out;
 423
 424	/*
 425	 * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL', which
 426	 * implies that buffer can't accommodate all information, and a partial buffer
 427	 * returned. To handle that, we need to take subsequent requests
 428	 * with next starting index to retrieve additional (missing) data.
 429	 * Below loop do subsequent hcalls with next starting index and add it
 430	 * to buffer util we get all the information.
 431	 */
 432	while (ret == H_PARAMETER) {
 433		int returned_values = be16_to_cpu(arg->params.returned_values);
 434		int elementsize = be16_to_cpu(arg->params.cv_element_size);
 435		int last_element = (returned_values - 1) * elementsize;
 436
 437		/*
 438		 * Since the starting index value is part of counter_value
 439		 * buffer elements, use the starting index value in the last
 440		 * element and add 1 to make subsequent hcalls.
 441		 */
 442		u32 starting_index = arg->bytes[last_element + 1] +
 443			(arg->bytes[last_element] << 8) + 1;
 444
 445		memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 446
 447		ret = systeminfo_gpci_request(sysinfo_counter_request[AFFINITY_DOMAIN_VIA_DOM],
 448					starting_index, 0, buf, &n, arg);
 449
 450		if (!ret)
 451			return n;
 452
 453		if (ret != H_PARAMETER)
 454			goto out;
 455	}
 456
 457	return n;
 458
 459out:
 460	put_cpu_var(hv_gpci_reqb);
 461	return ret;
 462}
 463
 464static void affinity_domain_via_partition_result_parse(int returned_values,
 465			int element_size, char *buf, size_t *last_element,
 466			size_t *n, struct hv_gpci_request_buffer *arg)
 467{
 468	size_t i = 0, j = 0;
 469	size_t k, l, m;
 470	uint16_t total_affinity_domain_ele, size_of_each_affinity_domain_ele;
 471
 472	/*
 473	 * hcall H_GET_PERF_COUNTER_INFO populates the 'returned_values'
 474	 * to show the total number of counter_value array elements
 475	 * returned via hcall.
 476	 * Unlike other request types, the data structure returned by this
 477	 * request is variable-size. For this counter request type,
 478	 * hcall populates 'cv_element_size' corresponds to minimum size of
 479	 * the structure returned i.e; the size of the structure with no domain
 480	 * information. Below loop go through all counter_value array
 481	 * to determine the number and size of each domain array element and
 482	 * add it to the output buffer.
 483	 */
 484	while (i < returned_values) {
 485		k = j;
 486		for (; k < j + element_size; k++)
 487			*n += sprintf(buf + *n,  "%02x", (u8)arg->bytes[k]);
 488		*n += sprintf(buf + *n,  "\n");
 489
 490		total_affinity_domain_ele = (u8)arg->bytes[k - 2] << 8 | (u8)arg->bytes[k - 3];
 491		size_of_each_affinity_domain_ele = (u8)arg->bytes[k] << 8 | (u8)arg->bytes[k - 1];
 492
 493		for (l = 0; l < total_affinity_domain_ele; l++) {
 494			for (m = 0; m < size_of_each_affinity_domain_ele; m++) {
 495				*n += sprintf(buf + *n,  "%02x", (u8)arg->bytes[k]);
 496				k++;
 497			}
 498			*n += sprintf(buf + *n,  "\n");
 499		}
 500
 501		*n += sprintf(buf + *n,  "\n");
 502		i++;
 503		j = k;
 504	}
 505
 506	*last_element = k;
 507}
 508
 509static ssize_t affinity_domain_via_partition_show(struct device *dev, struct device_attribute *attr,
 510							char *buf)
 511{
 512	struct hv_gpci_request_buffer *arg;
 513	unsigned long ret;
 514	size_t n = 0;
 515	size_t last_element = 0;
 516	u32 starting_index;
 517
 518	arg = (void *)get_cpu_var(hv_gpci_reqb);
 519	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 520
 521	/*
 522	 * Pass the counter request value 0xB1 corresponds to counter request
 523	 * type 'Affinity_domain_information_by_partition',
 524	 * to retrieve the system affinity domain by partition information.
 525	 * starting_index value refers to the starting hardware
 526	 * processor index.
 527	 */
 528	arg->params.counter_request = cpu_to_be32(sysinfo_counter_request[AFFINITY_DOMAIN_VIA_PAR]);
 529	arg->params.starting_index = cpu_to_be32(0);
 530
 531	ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
 532			virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
 533
 534	if (!ret)
 535		goto parse_result;
 536
 537	if (ret && (ret != H_PARAMETER))
 538		goto out;
 539
 540	/*
 541	 * ret value as 'H_PARAMETER' implies that the current buffer size
 542	 * can't accommodate all the information, and a partial buffer
 543	 * returned. To handle that, we need to make subsequent requests
 544	 * with next starting index to retrieve additional (missing) data.
 545	 * Below loop do subsequent hcalls with next starting index and add it
 546	 * to buffer util we get all the information.
 547	 */
 548	while (ret == H_PARAMETER) {
 549		affinity_domain_via_partition_result_parse(
 550			be16_to_cpu(arg->params.returned_values) - 1,
 551			be16_to_cpu(arg->params.cv_element_size), buf,
 552			&last_element, &n, arg);
 553
 554		if (n >= PAGE_SIZE) {
 555			put_cpu_var(hv_gpci_reqb);
 556			pr_debug("System information exceeds PAGE_SIZE\n");
 557			return -EFBIG;
 558		}
 559
 560		/*
 561		 * Since the starting index value is part of counter_value
 562		 * buffer elements, use the starting_index value in the last
 563		 * element and add 1 to make subsequent hcalls.
 564		 */
 565		starting_index = (u8)arg->bytes[last_element] << 8 |
 566				(u8)arg->bytes[last_element + 1];
 567
 568		memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 569		arg->params.counter_request = cpu_to_be32(
 570				sysinfo_counter_request[AFFINITY_DOMAIN_VIA_PAR]);
 571		arg->params.starting_index = cpu_to_be32(starting_index);
 572
 573		ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
 574				virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
 575
 576		if (ret && (ret != H_PARAMETER))
 577			goto out;
 578	}
 579
 580parse_result:
 581	affinity_domain_via_partition_result_parse(
 582		be16_to_cpu(arg->params.returned_values),
 583		be16_to_cpu(arg->params.cv_element_size),
 584		buf, &last_element, &n, arg);
 585
 586	put_cpu_var(hv_gpci_reqb);
 587	return n;
 588
 589out:
 590	put_cpu_var(hv_gpci_reqb);
 591
 592	/*
 593	 * ret value as 'H_PARAMETER' corresponds to 'GEN_BUF_TOO_SMALL',
 594	 * which means that the current buffer size cannot accommodate
 595	 * all the information and a partial buffer returned.
 596	 * hcall fails incase of ret value other than H_SUCCESS or H_PARAMETER.
 597	 *
 598	 * ret value as H_AUTHORITY implies that partition is not permitted to retrieve
 599	 * performance information, and required to set
 600	 * "Enable Performance Information Collection" option.
 601	 */
 602	if (ret == H_AUTHORITY)
 603		return -EPERM;
 604
 605	/*
 606	 * hcall can fail with other possible ret value like H_PRIVILEGE/H_HARDWARE
 607	 * because of invalid buffer-length/address or due to some hardware
 608	 * error.
 609	 */
 610	return -EIO;
 611}
 612
 613static DEVICE_ATTR_RO(kernel_version);
 614static DEVICE_ATTR_RO(cpumask);
 615
 616HV_CAPS_ATTR(version, "0x%x\n");
 617HV_CAPS_ATTR(ga, "%d\n");
 618HV_CAPS_ATTR(expanded, "%d\n");
 619HV_CAPS_ATTR(lab, "%d\n");
 620HV_CAPS_ATTR(collect_privileged, "%d\n");
 621
 622static struct attribute *interface_attrs[] = {
 623	&dev_attr_kernel_version.attr,
 624	&hv_caps_attr_version.attr,
 625	&hv_caps_attr_ga.attr,
 626	&hv_caps_attr_expanded.attr,
 627	&hv_caps_attr_lab.attr,
 628	&hv_caps_attr_collect_privileged.attr,
 629	/*
 630	 * This NULL is a placeholder for the processor_bus_topology
 631	 * attribute, set in init function if applicable.
 632	 */
 633	NULL,
 634	/*
 635	 * This NULL is a placeholder for the processor_config
 636	 * attribute, set in init function if applicable.
 637	 */
 638	NULL,
 639	/*
 640	 * This NULL is a placeholder for the affinity_domain_via_virtual_processor
 641	 * attribute, set in init function if applicable.
 642	 */
 643	NULL,
 644	/*
 645	 * This NULL is a placeholder for the affinity_domain_via_domain
 646	 * attribute, set in init function if applicable.
 647	 */
 648	NULL,
 649	/*
 650	 * This NULL is a placeholder for the affinity_domain_via_partition
 651	 * attribute, set in init function if applicable.
 652	 */
 653	NULL,
 654	NULL,
 655};
 656
 657static struct attribute *cpumask_attrs[] = {
 658	&dev_attr_cpumask.attr,
 659	NULL,
 660};
 661
 662static const struct attribute_group cpumask_attr_group = {
 663	.attrs = cpumask_attrs,
 664};
 665
 666static const struct attribute_group interface_group = {
 667	.name = "interface",
 668	.attrs = interface_attrs,
 669};
 670
 671static const struct attribute_group *attr_groups[] = {
 672	&format_group,
 673	&event_group,
 674	&interface_group,
 675	&cpumask_attr_group,
 676	NULL,
 677};
 678
 
 
 679static unsigned long single_gpci_request(u32 req, u32 starting_index,
 680		u16 secondary_index, u8 version_in, u32 offset, u8 length,
 681		u64 *value)
 682{
 683	unsigned long ret;
 684	size_t i;
 685	u64 count;
 686	struct hv_gpci_request_buffer *arg;
 687
 688	arg = (void *)get_cpu_var(hv_gpci_reqb);
 689	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 690
 691	arg->params.counter_request = cpu_to_be32(req);
 692	arg->params.starting_index = cpu_to_be32(starting_index);
 693	arg->params.secondary_index = cpu_to_be16(secondary_index);
 694	arg->params.counter_info_version_in = version_in;
 695
 696	ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
 697			virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
 698	if (ret) {
 699		pr_devel("hcall failed: 0x%lx\n", ret);
 700		goto out;
 701	}
 702
 703	/*
 704	 * we verify offset and length are within the zeroed buffer at event
 705	 * init.
 706	 */
 707	count = 0;
 708	for (i = offset; i < offset + length; i++)
 709		count |= (u64)(arg->bytes[i]) << ((length - 1 - (i - offset)) * 8);
 710
 711	*value = count;
 712out:
 713	put_cpu_var(hv_gpci_reqb);
 714	return ret;
 715}
 716
 717static u64 h_gpci_get_value(struct perf_event *event)
 718{
 719	u64 count;
 720	unsigned long ret = single_gpci_request(event_get_request(event),
 721					event_get_starting_index(event),
 722					event_get_secondary_index(event),
 723					event_get_counter_info_version(event),
 724					event_get_offset(event),
 725					event_get_length(event),
 726					&count);
 727	if (ret)
 728		return 0;
 729	return count;
 730}
 731
 732static void h_gpci_event_update(struct perf_event *event)
 733{
 734	s64 prev;
 735	u64 now = h_gpci_get_value(event);
 736	prev = local64_xchg(&event->hw.prev_count, now);
 737	local64_add(now - prev, &event->count);
 738}
 739
 740static void h_gpci_event_start(struct perf_event *event, int flags)
 741{
 742	local64_set(&event->hw.prev_count, h_gpci_get_value(event));
 743}
 744
 745static void h_gpci_event_stop(struct perf_event *event, int flags)
 746{
 747	h_gpci_event_update(event);
 748}
 749
 750static int h_gpci_event_add(struct perf_event *event, int flags)
 751{
 752	if (flags & PERF_EF_START)
 753		h_gpci_event_start(event, flags);
 754
 755	return 0;
 756}
 757
 758static int h_gpci_event_init(struct perf_event *event)
 759{
 760	u64 count;
 761	u8 length;
 762
 763	/* Not our event */
 764	if (event->attr.type != event->pmu->type)
 765		return -ENOENT;
 766
 767	/* config2 is unused */
 768	if (event->attr.config2) {
 769		pr_devel("config2 set when reserved\n");
 770		return -EINVAL;
 771	}
 772
 773	/* no branch sampling */
 774	if (has_branch_stack(event))
 775		return -EOPNOTSUPP;
 776
 777	length = event_get_length(event);
 778	if (length < 1 || length > 8) {
 779		pr_devel("length invalid\n");
 780		return -EINVAL;
 781	}
 782
 783	/* last byte within the buffer? */
 784	if ((event_get_offset(event) + length) > HGPCI_MAX_DATA_BYTES) {
 785		pr_devel("request outside of buffer: %zu > %zu\n",
 786				(size_t)event_get_offset(event) + length,
 787				HGPCI_MAX_DATA_BYTES);
 788		return -EINVAL;
 789	}
 790
 791	/* check if the request works... */
 792	if (single_gpci_request(event_get_request(event),
 793				event_get_starting_index(event),
 794				event_get_secondary_index(event),
 795				event_get_counter_info_version(event),
 796				event_get_offset(event),
 797				length,
 798				&count)) {
 799		pr_devel("gpci hcall failed\n");
 800		return -EINVAL;
 801	}
 802
 803	return 0;
 804}
 805
 806static struct pmu h_gpci_pmu = {
 807	.task_ctx_nr = perf_invalid_context,
 808
 809	.name = "hv_gpci",
 810	.attr_groups = attr_groups,
 811	.event_init  = h_gpci_event_init,
 812	.add         = h_gpci_event_add,
 813	.del         = h_gpci_event_stop,
 814	.start       = h_gpci_event_start,
 815	.stop        = h_gpci_event_stop,
 816	.read        = h_gpci_event_update,
 817	.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
 818};
 819
 820static int ppc_hv_gpci_cpu_online(unsigned int cpu)
 821{
 822	if (cpumask_empty(&hv_gpci_cpumask))
 823		cpumask_set_cpu(cpu, &hv_gpci_cpumask);
 824
 825	return 0;
 826}
 827
 828static int ppc_hv_gpci_cpu_offline(unsigned int cpu)
 829{
 830	int target;
 831
 832	/* Check if exiting cpu is used for collecting gpci events */
 833	if (!cpumask_test_and_clear_cpu(cpu, &hv_gpci_cpumask))
 834		return 0;
 835
 836	/* Find a new cpu to collect gpci events */
 837	target = cpumask_last(cpu_active_mask);
 838
 839	if (target < 0 || target >= nr_cpu_ids) {
 840		pr_err("hv_gpci: CPU hotplug init failed\n");
 841		return -1;
 842	}
 843
 844	/* Migrate gpci events to the new target */
 845	cpumask_set_cpu(target, &hv_gpci_cpumask);
 846	perf_pmu_migrate_context(&h_gpci_pmu, cpu, target);
 847
 848	return 0;
 849}
 850
 851static int hv_gpci_cpu_hotplug_init(void)
 852{
 853	return cpuhp_setup_state(CPUHP_AP_PERF_POWERPC_HV_GPCI_ONLINE,
 854			  "perf/powerpc/hv_gcpi:online",
 855			  ppc_hv_gpci_cpu_online,
 856			  ppc_hv_gpci_cpu_offline);
 857}
 858
 859static struct device_attribute *sysinfo_device_attr_create(int
 860		sysinfo_interface_group_index, u32 req)
 861{
 862	struct device_attribute *attr = NULL;
 863	unsigned long ret;
 864	struct hv_gpci_request_buffer *arg;
 865
 866	if (sysinfo_interface_group_index < INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR ||
 867			sysinfo_interface_group_index >= INTERFACE_NULL_ATTR) {
 868		pr_info("Wrong interface group index for system information\n");
 869		return NULL;
 870	}
 871
 872	/* Check for given counter request value support */
 873	arg = (void *)get_cpu_var(hv_gpci_reqb);
 874	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 875
 876	arg->params.counter_request = cpu_to_be32(req);
 877
 878	ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
 879			virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
 880
 881	put_cpu_var(hv_gpci_reqb);
 882
 883	/*
 884	 * Add given counter request value attribute in the interface_attrs
 885	 * attribute array, only for valid return types.
 886	 */
 887	if (!ret || ret == H_AUTHORITY || ret == H_PARAMETER) {
 888		attr = kzalloc(sizeof(*attr), GFP_KERNEL);
 889		if (!attr)
 890			return NULL;
 891
 892		sysfs_attr_init(&attr->attr);
 893		attr->attr.mode = 0444;
 894
 895		switch (sysinfo_interface_group_index) {
 896		case INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR:
 897			attr->attr.name = "processor_bus_topology";
 898			attr->show = processor_bus_topology_show;
 899		break;
 900		case INTERFACE_PROCESSOR_CONFIG_ATTR:
 901			attr->attr.name = "processor_config";
 902			attr->show = processor_config_show;
 903		break;
 904		case INTERFACE_AFFINITY_DOMAIN_VIA_VP_ATTR:
 905			attr->attr.name = "affinity_domain_via_virtual_processor";
 906			attr->show = affinity_domain_via_virtual_processor_show;
 907		break;
 908		case INTERFACE_AFFINITY_DOMAIN_VIA_DOM_ATTR:
 909			attr->attr.name = "affinity_domain_via_domain";
 910			attr->show = affinity_domain_via_domain_show;
 911		break;
 912		case INTERFACE_AFFINITY_DOMAIN_VIA_PAR_ATTR:
 913			attr->attr.name = "affinity_domain_via_partition";
 914			attr->show = affinity_domain_via_partition_show;
 915		break;
 916		}
 917	} else
 918		pr_devel("hcall failed, with error: 0x%lx\n", ret);
 919
 920	return attr;
 921}
 922
 923static void add_sysinfo_interface_files(void)
 924{
 925	int sysfs_count;
 926	struct device_attribute *attr[INTERFACE_NULL_ATTR - INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR];
 927	int i;
 928
 929	sysfs_count = INTERFACE_NULL_ATTR - INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR;
 930
 931	/* Get device attribute for a given counter request value */
 932	for (i = 0; i < sysfs_count; i++) {
 933		attr[i] = sysinfo_device_attr_create(i + INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR,
 934				sysinfo_counter_request[i]);
 935
 936		if (!attr[i])
 937			goto out;
 938	}
 939
 940	/* Add sysinfo interface attributes in the interface_attrs attribute array */
 941	for (i = 0; i < sysfs_count; i++)
 942		interface_attrs[i + INTERFACE_PROCESSOR_BUS_TOPOLOGY_ATTR] = &attr[i]->attr;
 943
 944	return;
 945
 946out:
 947	/*
 948	 * The sysinfo interface attributes will be added, only if hcall passed for
 949	 * all the counter request values. Free the device attribute array incase
 950	 * of any hcall failure.
 951	 */
 952	if (i > 0) {
 953		while (i >= 0) {
 954			kfree(attr[i]);
 955			i--;
 956		}
 957	}
 958}
 959
 960static int hv_gpci_init(void)
 961{
 962	int r;
 963	unsigned long hret;
 964	struct hv_perf_caps caps;
 965	struct hv_gpci_request_buffer *arg;
 966
 967	hv_gpci_assert_offsets_correct();
 968
 969	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
 970		pr_debug("not a virtualized system, not enabling\n");
 971		return -ENODEV;
 972	}
 973
 974	hret = hv_perf_caps_get(&caps);
 975	if (hret) {
 976		pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
 977				hret);
 978		return -ENODEV;
 979	}
 980
 981	/* init cpuhotplug */
 982	r = hv_gpci_cpu_hotplug_init();
 983	if (r)
 984		return r;
 985
 986	/* sampling not supported */
 987	h_gpci_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;
 988
 989	arg = (void *)get_cpu_var(hv_gpci_reqb);
 990	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
 991
 992	/*
 993	 * hcall H_GET_PERF_COUNTER_INFO populates the output
 994	 * counter_info_version value based on the system hypervisor.
 995	 * Pass the counter request 0x10 corresponds to request type
 996	 * 'Dispatch_timebase_by_processor', to get the supported
 997	 * counter_info_version.
 998	 */
 999	arg->params.counter_request = cpu_to_be32(0x10);
1000
1001	r = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
1002			virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
1003	if (r) {
1004		pr_devel("hcall failed, can't get supported counter_info_version: 0x%x\n", r);
1005		arg->params.counter_info_version_out = 0x8;
1006	}
1007
1008	/*
1009	 * Use counter_info_version_out value to assign
1010	 * required hv-gpci event list.
1011	 */
1012	if (arg->params.counter_info_version_out >= 0x8)
1013		event_group.attrs = hv_gpci_event_attrs;
1014	else
1015		event_group.attrs = hv_gpci_event_attrs_v6;
1016
1017	put_cpu_var(hv_gpci_reqb);
1018
1019	r = perf_pmu_register(&h_gpci_pmu, h_gpci_pmu.name, -1);
1020	if (r)
1021		return r;
1022
1023	/* sysinfo interface files are only available for power10 and above platforms */
1024	if (PVR_VER(mfspr(SPRN_PVR)) >= PVR_POWER10)
1025		add_sysinfo_interface_files();
1026
1027	return 0;
1028}
1029
1030device_initcall(hv_gpci_init);