[linux-block.git] / arch / powerpc / perf / hv-gpci.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Hypervisor supplied "gpci" ("get performance counter info") performance
 * counter support
 *
 * Author: Cody P Schafer <cody@linux.vnet.ibm.com>
 * Copyright 2014 IBM Corporation.
 */

#define pr_fmt(fmt) "hv-gpci: " fmt

#include <linux/init.h>
#include <linux/perf_event.h>
#include <asm/firmware.h>
#include <asm/hvcall.h>
#include <asm/io.h>

#include "hv-gpci.h"
#include "hv-common.h"

/*
 * Example usage:
 *  perf stat -e 'hv_gpci/counter_info_version=3,offset=0,length=8,
 *		  secondary_index=0,starting_index=0xffffffff,request=0x10/' ...
 */

/* u32 */
EVENT_DEFINE_RANGE_FORMAT(request, config, 0, 31);
/* u32 */
/*
 * Note that starting_index, phys_processor_idx, sibling_part_id,
 * hw_chip_id, partition_id all refer to the same bit range. They
 * are basically aliases for the starting_index. The specific alias
 * used depends on the event. See REQUEST_IDX_KIND in hv-gpci-requests.h
 */
EVENT_DEFINE_RANGE_FORMAT(starting_index, config, 32, 63);
EVENT_DEFINE_RANGE_FORMAT_LITE(phys_processor_idx, config, 32, 63);
EVENT_DEFINE_RANGE_FORMAT_LITE(sibling_part_id, config, 32, 63);
EVENT_DEFINE_RANGE_FORMAT_LITE(hw_chip_id, config, 32, 63);
EVENT_DEFINE_RANGE_FORMAT_LITE(partition_id, config, 32, 63);

/* u16 */
EVENT_DEFINE_RANGE_FORMAT(secondary_index, config1, 0, 15);
/* u8 */
EVENT_DEFINE_RANGE_FORMAT(counter_info_version, config1, 16, 23);
/* u8, bytes of data (1-8) */
EVENT_DEFINE_RANGE_FORMAT(length, config1, 24, 31);
/* u32, byte offset */
EVENT_DEFINE_RANGE_FORMAT(offset, config1, 32, 63);

static struct attribute *format_attrs[] = {
	&format_attr_request.attr,
	&format_attr_starting_index.attr,
	&format_attr_phys_processor_idx.attr,
	&format_attr_sibling_part_id.attr,
	&format_attr_hw_chip_id.attr,
	&format_attr_partition_id.attr,
	&format_attr_secondary_index.attr,
	&format_attr_counter_info_version.attr,

	&format_attr_offset.attr,
	&format_attr_length.attr,
	NULL,
};

static struct attribute_group format_group = {
	.name = "format",
	.attrs = format_attrs,
};

static struct attribute_group event_group = {
	.name  = "events",
	.attrs = hv_gpci_event_attrs,
};

#define HV_CAPS_ATTR(_name, _format)				\
static ssize_t _name##_show(struct device *dev,			\
			    struct device_attribute *attr,	\
			    char *page)				\
{								\
	struct hv_perf_caps caps;				\
	unsigned long hret = hv_perf_caps_get(&caps);		\
	if (hret)						\
		return -EIO;					\
								\
	return sprintf(page, _format, caps._name);		\
}								\
static struct device_attribute hv_caps_attr_##_name = __ATTR_RO(_name)

static ssize_t kernel_version_show(struct device *dev,
				   struct device_attribute *attr,
				   char *page)
{
	return sprintf(page, "0x%x\n", COUNTER_INFO_VERSION_CURRENT);
}

static DEVICE_ATTR_RO(kernel_version);
HV_CAPS_ATTR(version, "0x%x\n");
HV_CAPS_ATTR(ga, "%d\n");
HV_CAPS_ATTR(expanded, "%d\n");
HV_CAPS_ATTR(lab, "%d\n");
HV_CAPS_ATTR(collect_privileged, "%d\n");

static struct attribute *interface_attrs[] = {
	&dev_attr_kernel_version.attr,
	&hv_caps_attr_version.attr,
	&hv_caps_attr_ga.attr,
	&hv_caps_attr_expanded.attr,
	&hv_caps_attr_lab.attr,
	&hv_caps_attr_collect_privileged.attr,
	NULL,
};

static struct attribute_group interface_group = {
	.name = "interface",
	.attrs = interface_attrs,
};

static const struct attribute_group *attr_groups[] = {
	&format_group,
	&event_group,
	&interface_group,
	NULL,
};

static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE]) __aligned(sizeof(uint64_t));

static unsigned long single_gpci_request(u32 req, u32 starting_index,
		u16 secondary_index, u8 version_in, u32 offset, u8 length,
		u64 *value)
{
	unsigned long ret;
	size_t i;
	u64 count;
	struct hv_gpci_request_buffer *arg;

	arg = (void *)get_cpu_var(hv_gpci_reqb);
	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);

	arg->params.counter_request = cpu_to_be32(req);
	arg->params.starting_index = cpu_to_be32(starting_index);
	arg->params.secondary_index = cpu_to_be16(secondary_index);
	arg->params.counter_info_version_in = version_in;

	ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
			virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
	if (ret) {
		pr_devel("hcall failed: 0x%lx\n", ret);
		goto out;
	}

	/*
	 * we verify offset and length are within the zeroed buffer at event
	 * init.
	 */
	count = 0;
	for (i = offset; i < offset + length; i++)
		count |= arg->bytes[i] << (i - offset);

	*value = count;
out:
	put_cpu_var(hv_gpci_reqb);
	return ret;
}

static u64 h_gpci_get_value(struct perf_event *event)
{
	u64 count;
	unsigned long ret = single_gpci_request(event_get_request(event),
					event_get_starting_index(event),
					event_get_secondary_index(event),
					event_get_counter_info_version(event),
					event_get_offset(event),
					event_get_length(event),
					&count);
	if (ret)
		return 0;
	return count;
}

static void h_gpci_event_update(struct perf_event *event)
{
	s64 prev;
	u64 now = h_gpci_get_value(event);
	prev = local64_xchg(&event->hw.prev_count, now);
	local64_add(now - prev, &event->count);
}

static void h_gpci_event_start(struct perf_event *event, int flags)
{
	local64_set(&event->hw.prev_count, h_gpci_get_value(event));
}

static void h_gpci_event_stop(struct perf_event *event, int flags)
{
	h_gpci_event_update(event);
}

static int h_gpci_event_add(struct perf_event *event, int flags)
{
	if (flags & PERF_EF_START)
		h_gpci_event_start(event, flags);

	return 0;
}

static int h_gpci_event_init(struct perf_event *event)
{
	u64 count;
	u8 length;

	/* Not our event */
	if (event->attr.type != event->pmu->type)
		return -ENOENT;

	/* config2 is unused */
	if (event->attr.config2) {
		pr_devel("config2 set when reserved\n");
		return -EINVAL;
	}

	/* no branch sampling */
	if (has_branch_stack(event))
		return -EOPNOTSUPP;

	length = event_get_length(event);
	if (length < 1 || length > 8) {
		pr_devel("length invalid\n");
		return -EINVAL;
	}

	/* last byte within the buffer? */
	if ((event_get_offset(event) + length) > HGPCI_MAX_DATA_BYTES) {
		pr_devel("request outside of buffer: %zu > %zu\n",
				(size_t)event_get_offset(event) + length,
				HGPCI_MAX_DATA_BYTES);
		return -EINVAL;
	}

	/* check if the request works... */
	if (single_gpci_request(event_get_request(event),
				event_get_starting_index(event),
				event_get_secondary_index(event),
				event_get_counter_info_version(event),
				event_get_offset(event),
				length,
				&count)) {
		pr_devel("gpci hcall failed\n");
		return -EINVAL;
	}

	return 0;
}

static struct pmu h_gpci_pmu = {
	.task_ctx_nr = perf_invalid_context,

	.name = "hv_gpci",
	.attr_groups = attr_groups,
	.event_init  = h_gpci_event_init,
	.add         = h_gpci_event_add,
	.del         = h_gpci_event_stop,
	.start       = h_gpci_event_start,
	.stop        = h_gpci_event_stop,
	.read        = h_gpci_event_update,
	.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
};

static int hv_gpci_init(void)
{
	int r;
	unsigned long hret;
	struct hv_perf_caps caps;

	hv_gpci_assert_offsets_correct();

	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
		pr_debug("not a virtualized system, not enabling\n");
		return -ENODEV;
	}

	hret = hv_perf_caps_get(&caps);
	if (hret) {
		pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
				hret);
		return -ENODEV;
	}

	/* sampling not supported */
	h_gpci_pmu.capabilities |= PERF_PMU_CAP_NO_INTERRUPT;

	r = perf_pmu_register(&h_gpci_pmu, h_gpci_pmu.name, -1);
	if (r)
		return r;

	return 0;
}

device_initcall(hv_gpci_init);
Commit	Line	Data
2874c5fd	1	// SPDX-License-Identifier: GPL-2.0-or-later
220a0c60 CS	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.
220a0c60 CS	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 */
	28	EVENT_DEFINE_RANGE_FORMAT(request, config, 0, 31);
	29	/* u32 */
9e9f6010 CS	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	*/
220a0c60	36	EVENT_DEFINE_RANGE_FORMAT(starting_index, config, 32, 63);
9e9f6010 CS	37	EVENT_DEFINE_RANGE_FORMAT_LITE(phys_processor_idx, config, 32, 63);
	38	EVENT_DEFINE_RANGE_FORMAT_LITE(sibling_part_id, config, 32, 63);
	39	EVENT_DEFINE_RANGE_FORMAT_LITE(hw_chip_id, config, 32, 63);
	40	EVENT_DEFINE_RANGE_FORMAT_LITE(partition_id, config, 32, 63);
	41
220a0c60 CS	42	/* u16 */
	43	EVENT_DEFINE_RANGE_FORMAT(secondary_index, config1, 0, 15);
	44	/* u8 */
	45	EVENT_DEFINE_RANGE_FORMAT(counter_info_version, config1, 16, 23);
	46	/* u8, bytes of data (1-8) */
	47	EVENT_DEFINE_RANGE_FORMAT(length, config1, 24, 31);
	48	/* u32, byte offset */
	49	EVENT_DEFINE_RANGE_FORMAT(offset, config1, 32, 63);
	50
	51	static struct attribute *format_attrs[] = {
	52	&format_attr_request.attr,
	53	&format_attr_starting_index.attr,
9e9f6010 CS	54	&format_attr_phys_processor_idx.attr,
	55	&format_attr_sibling_part_id.attr,
	56	&format_attr_hw_chip_id.attr,
	57	&format_attr_partition_id.attr,
220a0c60 CS	58	&format_attr_secondary_index.attr,
	59	&format_attr_counter_info_version.attr,
	60
	61	&format_attr_offset.attr,
	62	&format_attr_length.attr,
	63	NULL,
	64	};
	65
	66	static struct attribute_group format_group = {
	67	.name = "format",
	68	.attrs = format_attrs,
	69	};
	70
9e9f6010 CS	71	static struct attribute_group event_group = {
	72	.name = "events",
	73	.attrs = hv_gpci_event_attrs,
	74	};
	75
220a0c60 CS	76	#define HV_CAPS_ATTR(_name, _format) \
	77	static ssize_t _name##_show(struct device *dev, \
	78	struct device_attribute *attr, \
	79	char *page) \
	80	{ \
	81	struct hv_perf_caps caps; \
	82	unsigned long hret = hv_perf_caps_get(&caps); \
	83	if (hret) \
	84	return -EIO; \
	85	\
	86	return sprintf(page, _format, caps._name); \
	87	} \
	88	static struct device_attribute hv_caps_attr_##_name = __ATTR_RO(_name)
	89
	90	static ssize_t kernel_version_show(struct device *dev,
	91	struct device_attribute *attr,
	92	char *page)
	93	{
	94	return sprintf(page, "0x%x\n", COUNTER_INFO_VERSION_CURRENT);
	95	}
	96
58a685c2	97	static DEVICE_ATTR_RO(kernel_version);
220a0c60 CS	98	HV_CAPS_ATTR(version, "0x%x\n");
	99	HV_CAPS_ATTR(ga, "%d\n");
	100	HV_CAPS_ATTR(expanded, "%d\n");
	101	HV_CAPS_ATTR(lab, "%d\n");
	102	HV_CAPS_ATTR(collect_privileged, "%d\n");
	103
	104	static struct attribute *interface_attrs[] = {
	105	&dev_attr_kernel_version.attr,
	106	&hv_caps_attr_version.attr,
	107	&hv_caps_attr_ga.attr,
	108	&hv_caps_attr_expanded.attr,
	109	&hv_caps_attr_lab.attr,
	110	&hv_caps_attr_collect_privileged.attr,
	111	NULL,
	112	};
	113
	114	static struct attribute_group interface_group = {
	115	.name = "interface",
	116	.attrs = interface_attrs,
	117	};
	118
	119	static const struct attribute_group *attr_groups[] = {
	120	&format_group,
9e9f6010	121	&event_group,
220a0c60 CS	122	&interface_group,
	123	NULL,
	124	};
	125
7c98bd72	126	static DEFINE_PER_CPU(char, hv_gpci_reqb[HGPCI_REQ_BUFFER_SIZE]) __aligned(sizeof(uint64_t));
e4f226b1	127
220a0c60 CS	128	static unsigned long single_gpci_request(u32 req, u32 starting_index,
	129	u16 secondary_index, u8 version_in, u32 offset, u8 length,
	130	u64 *value)
	131	{
	132	unsigned long ret;
	133	size_t i;
	134	u64 count;
e4f226b1 SB	135	struct hv_gpci_request_buffer *arg;
	136
	137	arg = (void *)get_cpu_var(hv_gpci_reqb);
	138	memset(arg, 0, HGPCI_REQ_BUFFER_SIZE);
220a0c60	139
e4f226b1 SB	140	arg->params.counter_request = cpu_to_be32(req);
	141	arg->params.starting_index = cpu_to_be32(starting_index);
	142	arg->params.secondary_index = cpu_to_be16(secondary_index);
	143	arg->params.counter_info_version_in = version_in;
220a0c60 CS	144
220a0c60 CS	145	ret = plpar_hcall_norets(H_GET_PERF_COUNTER_INFO,
e4f226b1	146	virt_to_phys(arg), HGPCI_REQ_BUFFER_SIZE);
220a0c60 CS	147	if (ret) {
220a0c60 CS	148	pr_devel("hcall failed: 0x%lx\n", ret);
e4f226b1	149	goto out;
220a0c60 CS	150	}
	151
	152	/*
	153	* we verify offset and length are within the zeroed buffer at event
	154	* init.
	155	*/
	156	count = 0;
	157	for (i = offset; i < offset + length; i++)
e4f226b1	158	count \|= arg->bytes[i] << (i - offset);
220a0c60 CS	159
220a0c60 CS	160	*value = count;
e4f226b1 SB	161	out:
e4f226b1 SB	162	put_cpu_var(hv_gpci_reqb);
220a0c60 CS	163	return ret;
	164	}
	165
	166	static u64 h_gpci_get_value(struct perf_event *event)
	167	{
	168	u64 count;
	169	unsigned long ret = single_gpci_request(event_get_request(event),
	170	event_get_starting_index(event),
	171	event_get_secondary_index(event),
	172	event_get_counter_info_version(event),
	173	event_get_offset(event),
	174	event_get_length(event),
	175	&count);
	176	if (ret)
	177	return 0;
	178	return count;
	179	}
	180
	181	static void h_gpci_event_update(struct perf_event *event)
	182	{
	183	s64 prev;
	184	u64 now = h_gpci_get_value(event);
	185	prev = local64_xchg(&event->hw.prev_count, now);
	186	local64_add(now - prev, &event->count);
	187	}
	188
	189	static void h_gpci_event_start(struct perf_event *event, int flags)
	190	{
	191	local64_set(&event->hw.prev_count, h_gpci_get_value(event));
	192	}
	193
	194	static void h_gpci_event_stop(struct perf_event *event, int flags)
	195	{
	196	h_gpci_event_update(event);
	197	}
	198
	199	static int h_gpci_event_add(struct perf_event *event, int flags)
	200	{
	201	if (flags & PERF_EF_START)
	202	h_gpci_event_start(event, flags);
	203
	204	return 0;
	205	}
	206
	207	static int h_gpci_event_init(struct perf_event *event)
	208	{
	209	u64 count;
	210	u8 length;
	211
	212	/* Not our event */
	213	if (event->attr.type != event->pmu->type)
	214	return -ENOENT;
	215
	216	/* config2 is unused */
	217	if (event->attr.config2) {
	218	pr_devel("config2 set when reserved\n");
	219	return -EINVAL;
	220	}
	221
220a0c60 CS	222	/* no branch sampling */
	223	if (has_branch_stack(event))
	224	return -EOPNOTSUPP;
	225
	226	length = event_get_length(event);
	227	if (length < 1 \|\| length > 8) {
	228	pr_devel("length invalid\n");
	229	return -EINVAL;
	230	}
	231
	232	/* last byte within the buffer? */
e4f226b1	233	if ((event_get_offset(event) + length) > HGPCI_MAX_DATA_BYTES) {
220a0c60 CS	234	pr_devel("request outside of buffer: %zu > %zu\n",
220a0c60 CS	235	(size_t)event_get_offset(event) + length,
e4f226b1	236	HGPCI_MAX_DATA_BYTES);
220a0c60 CS	237	return -EINVAL;
	238	}
	239
	240	/* check if the request works... */
	241	if (single_gpci_request(event_get_request(event),
	242	event_get_starting_index(event),
	243	event_get_secondary_index(event),
	244	event_get_counter_info_version(event),
	245	event_get_offset(event),
	246	length,
	247	&count)) {
	248	pr_devel("gpci hcall failed\n");
	249	return -EINVAL;
	250	}
	251
	252	return 0;
	253	}
	254
220a0c60 CS	255	static struct pmu h_gpci_pmu = {
	256	.task_ctx_nr = perf_invalid_context,
	257
	258	.name = "hv_gpci",
	259	.attr_groups = attr_groups,
	260	.event_init = h_gpci_event_init,
	261	.add = h_gpci_event_add,
	262	.del = h_gpci_event_stop,
	263	.start = h_gpci_event_start,
	264	.stop = h_gpci_event_stop,
	265	.read = h_gpci_event_update,
c2c9091d	266	.capabilities = PERF_PMU_CAP_NO_EXCLUDE,
220a0c60 CS	267	};
	268
	269	static int hv_gpci_init(void)
	270	{
	271	int r;
	272	unsigned long hret;
	273	struct hv_perf_caps caps;
	274
9e9f6010 CS	275	hv_gpci_assert_offsets_correct();
9e9f6010 CS	276
220a0c60	277	if (!firmware_has_feature(FW_FEATURE_LPAR)) {
0a8cf9e2	278	pr_debug("not a virtualized system, not enabling\n");
220a0c60 CS	279	return -ENODEV;
	280	}
	281
	282	hret = hv_perf_caps_get(&caps);
	283	if (hret) {
0a8cf9e2	284	pr_debug("could not obtain capabilities, not enabling, rc=%ld\n",
220a0c60 CS	285	hret);
	286	return -ENODEV;
	287	}
	288
cc56d673 VW	289	/* sampling not supported */
	290	h_gpci_pmu.capabilities \|= PERF_PMU_CAP_NO_INTERRUPT;
	291
220a0c60 CS	292	r = perf_pmu_register(&h_gpci_pmu, h_gpci_pmu.name, -1);
	293	if (r)
	294	return r;
	295
	296	return 0;
	297	}
	298
	299	device_initcall(hv_gpci_init);