[deliverable/linux.git] / tools / perf / arch / x86 / util / intel-bts.c

/*
 * intel-bts.c: Intel Processor Trace support
 * Copyright (c) 2013-2015, Intel Corporation.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms and conditions of the GNU General Public License,
 * version 2, as published by the Free Software Foundation.
 *
 * This program is distributed in the hope it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
 * more details.
 *
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/bitops.h>
#include <linux/log2.h>

#include "../../util/cpumap.h"
#include "../../util/evsel.h"
#include "../../util/evlist.h"
#include "../../util/session.h"
#include "../../util/util.h"
#include "../../util/pmu.h"
#include "../../util/debug.h"
#include "../../util/tsc.h"
#include "../../util/auxtrace.h"
#include "../../util/intel-bts.h"

#define KiB(x) ((x) * 1024)
#define MiB(x) ((x) * 1024 * 1024)
#define KiB_MASK(x) (KiB(x) - 1)
#define MiB_MASK(x) (MiB(x) - 1)

#define INTEL_BTS_DFLT_SAMPLE_SIZE	KiB(4)

#define INTEL_BTS_MAX_SAMPLE_SIZE	KiB(60)

struct intel_bts_snapshot_ref {
	void	*ref_buf;
	size_t	ref_offset;
	bool	wrapped;
};

struct intel_bts_recording {
	struct auxtrace_record		itr;
	struct perf_pmu			*intel_bts_pmu;
	struct perf_evlist		*evlist;
	bool				snapshot_mode;
	size_t				snapshot_size;
	int				snapshot_ref_cnt;
	struct intel_bts_snapshot_ref	*snapshot_refs;
};

struct branch {
	u64 from;
	u64 to;
	u64 misc;
};

static size_t
intel_bts_info_priv_size(struct auxtrace_record *itr __maybe_unused,
			 struct perf_evlist *evlist __maybe_unused)
{
	return INTEL_BTS_AUXTRACE_PRIV_SIZE;
}

static int intel_bts_info_fill(struct auxtrace_record *itr,
			       struct perf_session *session,
			       struct auxtrace_info_event *auxtrace_info,
			       size_t priv_size)
{
	struct intel_bts_recording *btsr =
			container_of(itr, struct intel_bts_recording, itr);
	struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
	struct perf_event_mmap_page *pc;
	struct perf_tsc_conversion tc = { .time_mult = 0, };
	bool cap_user_time_zero = false;
	int err;

	if (priv_size != INTEL_BTS_AUXTRACE_PRIV_SIZE)
		return -EINVAL;

	if (!session->evlist->nr_mmaps)
		return -EINVAL;

	pc = session->evlist->mmap[0].base;
	if (pc) {
		err = perf_read_tsc_conversion(pc, &tc);
		if (err) {
			if (err != -EOPNOTSUPP)
				return err;
		} else {
			cap_user_time_zero = tc.time_mult != 0;
		}
		if (!cap_user_time_zero)
			ui__warning("Intel BTS: TSC not available\n");
	}

	auxtrace_info->type = PERF_AUXTRACE_INTEL_BTS;
	auxtrace_info->priv[INTEL_BTS_PMU_TYPE] = intel_bts_pmu->type;
	auxtrace_info->priv[INTEL_BTS_TIME_SHIFT] = tc.time_shift;
	auxtrace_info->priv[INTEL_BTS_TIME_MULT] = tc.time_mult;
	auxtrace_info->priv[INTEL_BTS_TIME_ZERO] = tc.time_zero;
	auxtrace_info->priv[INTEL_BTS_CAP_USER_TIME_ZERO] = cap_user_time_zero;
	auxtrace_info->priv[INTEL_BTS_SNAPSHOT_MODE] = btsr->snapshot_mode;

	return 0;
}

static int intel_bts_recording_options(struct auxtrace_record *itr,
				       struct perf_evlist *evlist,
				       struct record_opts *opts)
{
	struct intel_bts_recording *btsr =
			container_of(itr, struct intel_bts_recording, itr);
	struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
	struct perf_evsel *evsel, *intel_bts_evsel = NULL;
	const struct cpu_map *cpus = evlist->cpus;
	bool privileged = geteuid() == 0 || perf_event_paranoid() < 0;

	btsr->evlist = evlist;
	btsr->snapshot_mode = opts->auxtrace_snapshot_mode;

	evlist__for_each_entry(evlist, evsel) {
		if (evsel->attr.type == intel_bts_pmu->type) {
			if (intel_bts_evsel) {
				pr_err("There may be only one " INTEL_BTS_PMU_NAME " event\n");
				return -EINVAL;
			}
			evsel->attr.freq = 0;
			evsel->attr.sample_period = 1;
			intel_bts_evsel = evsel;
			opts->full_auxtrace = true;
		}
	}

	if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
		pr_err("Snapshot mode (-S option) requires " INTEL_BTS_PMU_NAME " PMU event (-e " INTEL_BTS_PMU_NAME ")\n");
		return -EINVAL;
	}

	if (!opts->full_auxtrace)
		return 0;

	if (opts->full_auxtrace && !cpu_map__empty(cpus)) {
		pr_err(INTEL_BTS_PMU_NAME " does not support per-cpu recording\n");
		return -EINVAL;
	}

	/* Set default sizes for snapshot mode */
	if (opts->auxtrace_snapshot_mode) {
		if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
			if (privileged) {
				opts->auxtrace_mmap_pages = MiB(4) / page_size;
			} else {
				opts->auxtrace_mmap_pages = KiB(128) / page_size;
				if (opts->mmap_pages == UINT_MAX)
					opts->mmap_pages = KiB(256) / page_size;
			}
		} else if (!opts->auxtrace_mmap_pages && !privileged &&
			   opts->mmap_pages == UINT_MAX) {
			opts->mmap_pages = KiB(256) / page_size;
		}
		if (!opts->auxtrace_snapshot_size)
			opts->auxtrace_snapshot_size =
				opts->auxtrace_mmap_pages * (size_t)page_size;
		if (!opts->auxtrace_mmap_pages) {
			size_t sz = opts->auxtrace_snapshot_size;

			sz = round_up(sz, page_size) / page_size;
			opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
		}
		if (opts->auxtrace_snapshot_size >
				opts->auxtrace_mmap_pages * (size_t)page_size) {
			pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
			       opts->auxtrace_snapshot_size,
			       opts->auxtrace_mmap_pages * (size_t)page_size);
			return -EINVAL;
		}
		if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages) {
			pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
			return -EINVAL;
		}
		pr_debug2("Intel BTS snapshot size: %zu\n",
			  opts->auxtrace_snapshot_size);
	}

	/* Set default sizes for full trace mode */
	if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
		if (privileged) {
			opts->auxtrace_mmap_pages = MiB(4) / page_size;
		} else {
			opts->auxtrace_mmap_pages = KiB(128) / page_size;
			if (opts->mmap_pages == UINT_MAX)
				opts->mmap_pages = KiB(256) / page_size;
		}
	}

	/* Validate auxtrace_mmap_pages */
	if (opts->auxtrace_mmap_pages) {
		size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
		size_t min_sz;

		if (opts->auxtrace_snapshot_mode)
			min_sz = KiB(4);
		else
			min_sz = KiB(8);

		if (sz < min_sz || !is_power_of_2(sz)) {
			pr_err("Invalid mmap size for Intel BTS: must be at least %zuKiB and a power of 2\n",
			       min_sz / 1024);
			return -EINVAL;
		}
	}

	if (intel_bts_evsel) {
		/*
		 * To obtain the auxtrace buffer file descriptor, the auxtrace event
		 * must come first.
		 */
		perf_evlist__to_front(evlist, intel_bts_evsel);
		/*
		 * In the case of per-cpu mmaps, we need the CPU on the
		 * AUX event.
		 */
		if (!cpu_map__empty(cpus))
			perf_evsel__set_sample_bit(intel_bts_evsel, CPU);
	}

	/* Add dummy event to keep tracking */
	if (opts->full_auxtrace) {
		struct perf_evsel *tracking_evsel;
		int err;

		err = parse_events(evlist, "dummy:u", NULL);
		if (err)
			return err;

		tracking_evsel = perf_evlist__last(evlist);

		perf_evlist__set_tracking_event(evlist, tracking_evsel);

		tracking_evsel->attr.freq = 0;
		tracking_evsel->attr.sample_period = 1;
	}

	return 0;
}

static int intel_bts_parse_snapshot_options(struct auxtrace_record *itr,
					    struct record_opts *opts,
					    const char *str)
{
	struct intel_bts_recording *btsr =
			container_of(itr, struct intel_bts_recording, itr);
	unsigned long long snapshot_size = 0;
	char *endptr;

	if (str) {
		snapshot_size = strtoull(str, &endptr, 0);
		if (*endptr || snapshot_size > SIZE_MAX)
			return -1;
	}

	opts->auxtrace_snapshot_mode = true;
	opts->auxtrace_snapshot_size = snapshot_size;

	btsr->snapshot_size = snapshot_size;

	return 0;
}

static u64 intel_bts_reference(struct auxtrace_record *itr __maybe_unused)
{
	return rdtsc();
}

static int intel_bts_alloc_snapshot_refs(struct intel_bts_recording *btsr,
					 int idx)
{
	const size_t sz = sizeof(struct intel_bts_snapshot_ref);
	int cnt = btsr->snapshot_ref_cnt, new_cnt = cnt * 2;
	struct intel_bts_snapshot_ref *refs;

	if (!new_cnt)
		new_cnt = 16;

	while (new_cnt <= idx)
		new_cnt *= 2;

	refs = calloc(new_cnt, sz);
	if (!refs)
		return -ENOMEM;

	memcpy(refs, btsr->snapshot_refs, cnt * sz);

	btsr->snapshot_refs = refs;
	btsr->snapshot_ref_cnt = new_cnt;

	return 0;
}

static void intel_bts_free_snapshot_refs(struct intel_bts_recording *btsr)
{
	int i;

	for (i = 0; i < btsr->snapshot_ref_cnt; i++)
		zfree(&btsr->snapshot_refs[i].ref_buf);
	zfree(&btsr->snapshot_refs);
}

static void intel_bts_recording_free(struct auxtrace_record *itr)
{
	struct intel_bts_recording *btsr =
			container_of(itr, struct intel_bts_recording, itr);

	intel_bts_free_snapshot_refs(btsr);
	free(btsr);
}

static int intel_bts_snapshot_start(struct auxtrace_record *itr)
{
	struct intel_bts_recording *btsr =
			container_of(itr, struct intel_bts_recording, itr);
	struct perf_evsel *evsel;

	evlist__for_each_entry(btsr->evlist, evsel) {
		if (evsel->attr.type == btsr->intel_bts_pmu->type)
			return perf_evsel__disable(evsel);
	}
	return -EINVAL;
}

static int intel_bts_snapshot_finish(struct auxtrace_record *itr)
{
	struct intel_bts_recording *btsr =
			container_of(itr, struct intel_bts_recording, itr);
	struct perf_evsel *evsel;

	evlist__for_each_entry(btsr->evlist, evsel) {
		if (evsel->attr.type == btsr->intel_bts_pmu->type)
			return perf_evsel__enable(evsel);
	}
	return -EINVAL;
}

static bool intel_bts_first_wrap(u64 *data, size_t buf_size)
{
	int i, a, b;

	b = buf_size >> 3;
	a = b - 512;
	if (a < 0)
		a = 0;

	for (i = a; i < b; i++) {
		if (data[i])
			return true;
	}

	return false;
}

static int intel_bts_find_snapshot(struct auxtrace_record *itr, int idx,
				   struct auxtrace_mmap *mm, unsigned char *data,
				   u64 *head, u64 *old)
{
	struct intel_bts_recording *btsr =
			container_of(itr, struct intel_bts_recording, itr);
	bool wrapped;
	int err;

	pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
		  __func__, idx, (size_t)*old, (size_t)*head);

	if (idx >= btsr->snapshot_ref_cnt) {
		err = intel_bts_alloc_snapshot_refs(btsr, idx);
		if (err)
			goto out_err;
	}

	wrapped = btsr->snapshot_refs[idx].wrapped;
	if (!wrapped && intel_bts_first_wrap((u64 *)data, mm->len)) {
		btsr->snapshot_refs[idx].wrapped = true;
		wrapped = true;
	}

	/*
	 * In full trace mode 'head' continually increases.  However in snapshot
	 * mode 'head' is an offset within the buffer.  Here 'old' and 'head'
	 * are adjusted to match the full trace case which expects that 'old' is
	 * always less than 'head'.
	 */
	if (wrapped) {
		*old = *head;
		*head += mm->len;
	} else {
		if (mm->mask)
			*old &= mm->mask;
		else
			*old %= mm->len;
		if (*old > *head)
			*head += mm->len;
	}

	pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
		  __func__, wrapped ? "" : "not ", (size_t)*old, (size_t)*head);

	return 0;

out_err:
	pr_err("%s: failed, error %d\n", __func__, err);
	return err;
}

static int intel_bts_read_finish(struct auxtrace_record *itr, int idx)
{
	struct intel_bts_recording *btsr =
			container_of(itr, struct intel_bts_recording, itr);
	struct perf_evsel *evsel;

	evlist__for_each_entry(btsr->evlist, evsel) {
		if (evsel->attr.type == btsr->intel_bts_pmu->type)
			return perf_evlist__enable_event_idx(btsr->evlist,
							     evsel, idx);
	}
	return -EINVAL;
}

struct auxtrace_record *intel_bts_recording_init(int *err)
{
	struct perf_pmu *intel_bts_pmu = perf_pmu__find(INTEL_BTS_PMU_NAME);
	struct intel_bts_recording *btsr;

	if (!intel_bts_pmu)
		return NULL;

	if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
		*err = -errno;
		return NULL;
	}

	btsr = zalloc(sizeof(struct intel_bts_recording));
	if (!btsr) {
		*err = -ENOMEM;
		return NULL;
	}

	btsr->intel_bts_pmu = intel_bts_pmu;
	btsr->itr.recording_options = intel_bts_recording_options;
	btsr->itr.info_priv_size = intel_bts_info_priv_size;
	btsr->itr.info_fill = intel_bts_info_fill;
	btsr->itr.free = intel_bts_recording_free;
	btsr->itr.snapshot_start = intel_bts_snapshot_start;
	btsr->itr.snapshot_finish = intel_bts_snapshot_finish;
	btsr->itr.find_snapshot = intel_bts_find_snapshot;
	btsr->itr.parse_snapshot_options = intel_bts_parse_snapshot_options;
	btsr->itr.reference = intel_bts_reference;
	btsr->itr.read_finish = intel_bts_read_finish;
	btsr->itr.alignment = sizeof(struct branch);
	return &btsr->itr;
}
Commit	Line	Data
d0170af7 AH	1	/*
	2	* intel-bts.c: Intel Processor Trace support
	3	* Copyright (c) 2013-2015, Intel Corporation.
	4	*
	5	* This program is free software; you can redistribute it and/or modify it
	6	* under the terms and conditions of the GNU General Public License,
	7	* version 2, as published by the Free Software Foundation.
	8	*
	9	* This program is distributed in the hope it will be useful, but WITHOUT
	10	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	11	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	12	* more details.
	13	*
	14	*/
	15
	16	#include <linux/kernel.h>
	17	#include <linux/types.h>
	18	#include <linux/bitops.h>
	19	#include <linux/log2.h>
	20
	21	#include "../../util/cpumap.h"
	22	#include "../../util/evsel.h"
	23	#include "../../util/evlist.h"
	24	#include "../../util/session.h"
	25	#include "../../util/util.h"
	26	#include "../../util/pmu.h"
	27	#include "../../util/debug.h"
	28	#include "../../util/tsc.h"
	29	#include "../../util/auxtrace.h"
	30	#include "../../util/intel-bts.h"
	31
	32	#define KiB(x) ((x) * 1024)
	33	#define MiB(x) ((x) * 1024 * 1024)
	34	#define KiB_MASK(x) (KiB(x) - 1)
	35	#define MiB_MASK(x) (MiB(x) - 1)
	36
	37	#define INTEL_BTS_DFLT_SAMPLE_SIZE KiB(4)
	38
	39	#define INTEL_BTS_MAX_SAMPLE_SIZE KiB(60)
	40
	41	struct intel_bts_snapshot_ref {
	42	void *ref_buf;
	43	size_t ref_offset;
	44	bool wrapped;
	45	};
	46
	47	struct intel_bts_recording {
	48	struct auxtrace_record itr;
	49	struct perf_pmu *intel_bts_pmu;
	50	struct perf_evlist *evlist;
	51	bool snapshot_mode;
	52	size_t snapshot_size;
	53	int snapshot_ref_cnt;
	54	struct intel_bts_snapshot_ref *snapshot_refs;
	55	};
	56
	57	struct branch {
	58	u64 from;
	59	u64 to;
	60	u64 misc;
	61	};
	62
14a05e13 MP	63	static size_t
	64	intel_bts_info_priv_size(struct auxtrace_record *itr __maybe_unused,
	65	struct perf_evlist *evlist __maybe_unused)
d0170af7 AH	66	{
	67	return INTEL_BTS_AUXTRACE_PRIV_SIZE;
	68	}
	69
	70	static int intel_bts_info_fill(struct auxtrace_record *itr,
	71	struct perf_session *session,
	72	struct auxtrace_info_event *auxtrace_info,
	73	size_t priv_size)
	74	{
	75	struct intel_bts_recording *btsr =
	76	container_of(itr, struct intel_bts_recording, itr);
	77	struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
	78	struct perf_event_mmap_page *pc;
	79	struct perf_tsc_conversion tc = { .time_mult = 0, };
	80	bool cap_user_time_zero = false;
	81	int err;
	82
	83	if (priv_size != INTEL_BTS_AUXTRACE_PRIV_SIZE)
	84	return -EINVAL;
	85
	86	if (!session->evlist->nr_mmaps)
	87	return -EINVAL;
	88
	89	pc = session->evlist->mmap[0].base;
	90	if (pc) {
	91	err = perf_read_tsc_conversion(pc, &tc);
	92	if (err) {
	93	if (err != -EOPNOTSUPP)
	94	return err;
	95	} else {
	96	cap_user_time_zero = tc.time_mult != 0;
	97	}
	98	if (!cap_user_time_zero)
	99	ui__warning("Intel BTS: TSC not available\n");
	100	}
	101
	102	auxtrace_info->type = PERF_AUXTRACE_INTEL_BTS;
	103	auxtrace_info->priv[INTEL_BTS_PMU_TYPE] = intel_bts_pmu->type;
	104	auxtrace_info->priv[INTEL_BTS_TIME_SHIFT] = tc.time_shift;
	105	auxtrace_info->priv[INTEL_BTS_TIME_MULT] = tc.time_mult;
	106	auxtrace_info->priv[INTEL_BTS_TIME_ZERO] = tc.time_zero;
	107	auxtrace_info->priv[INTEL_BTS_CAP_USER_TIME_ZERO] = cap_user_time_zero;
	108	auxtrace_info->priv[INTEL_BTS_SNAPSHOT_MODE] = btsr->snapshot_mode;
	109
	110	return 0;
	111	}
	112
	113	static int intel_bts_recording_options(struct auxtrace_record *itr,
	114	struct perf_evlist *evlist,
	115	struct record_opts *opts)
	116	{
	117	struct intel_bts_recording *btsr =
	118	container_of(itr, struct intel_bts_recording, itr);
	119	struct perf_pmu *intel_bts_pmu = btsr->intel_bts_pmu;
	120	struct perf_evsel evsel, intel_bts_evsel = NULL;
	121	const struct cpu_map *cpus = evlist->cpus;
	122	bool privileged = geteuid() == 0 \|\| perf_event_paranoid() < 0;
	123
	124	btsr->evlist = evlist;
	125	btsr->snapshot_mode = opts->auxtrace_snapshot_mode;
	126
e5cadb93	127	evlist__for_each_entry(evlist, evsel) {
d0170af7 AH	128	if (evsel->attr.type == intel_bts_pmu->type) {
	129	if (intel_bts_evsel) {
	130	pr_err("There may be only one " INTEL_BTS_PMU_NAME " event\n");
	131	return -EINVAL;
	132	}
	133	evsel->attr.freq = 0;
	134	evsel->attr.sample_period = 1;
	135	intel_bts_evsel = evsel;
	136	opts->full_auxtrace = true;
	137	}
	138	}
	139
	140	if (opts->auxtrace_snapshot_mode && !opts->full_auxtrace) {
	141	pr_err("Snapshot mode (-S option) requires " INTEL_BTS_PMU_NAME " PMU event (-e " INTEL_BTS_PMU_NAME ")\n");
	142	return -EINVAL;
	143	}
	144
	145	if (!opts->full_auxtrace)
	146	return 0;
	147
	148	if (opts->full_auxtrace && !cpu_map__empty(cpus)) {
	149	pr_err(INTEL_BTS_PMU_NAME " does not support per-cpu recording\n");
	150	return -EINVAL;
	151	}
	152
	153	/* Set default sizes for snapshot mode */
	154	if (opts->auxtrace_snapshot_mode) {
	155	if (!opts->auxtrace_snapshot_size && !opts->auxtrace_mmap_pages) {
	156	if (privileged) {
	157	opts->auxtrace_mmap_pages = MiB(4) / page_size;
	158	} else {
	159	opts->auxtrace_mmap_pages = KiB(128) / page_size;
	160	if (opts->mmap_pages == UINT_MAX)
	161	opts->mmap_pages = KiB(256) / page_size;
	162	}
	163	} else if (!opts->auxtrace_mmap_pages && !privileged &&
	164	opts->mmap_pages == UINT_MAX) {
	165	opts->mmap_pages = KiB(256) / page_size;
	166	}
	167	if (!opts->auxtrace_snapshot_size)
	168	opts->auxtrace_snapshot_size =
	169	opts->auxtrace_mmap_pages * (size_t)page_size;
	170	if (!opts->auxtrace_mmap_pages) {
	171	size_t sz = opts->auxtrace_snapshot_size;
	172
	173	sz = round_up(sz, page_size) / page_size;
	174	opts->auxtrace_mmap_pages = roundup_pow_of_two(sz);
	175	}
	176	if (opts->auxtrace_snapshot_size >
	177	opts->auxtrace_mmap_pages * (size_t)page_size) {
	178	pr_err("Snapshot size %zu must not be greater than AUX area tracing mmap size %zu\n",
	179	opts->auxtrace_snapshot_size,
	180	opts->auxtrace_mmap_pages * (size_t)page_size);
	181	return -EINVAL;
	182	}
	183	if (!opts->auxtrace_snapshot_size \|\| !opts->auxtrace_mmap_pages) {
	184	pr_err("Failed to calculate default snapshot size and/or AUX area tracing mmap pages\n");
	185	return -EINVAL;
	186	}
	187	pr_debug2("Intel BTS snapshot size: %zu\n",
	188	opts->auxtrace_snapshot_size);
	189	}
	190
	191	/* Set default sizes for full trace mode */
192	if (opts->full_auxtrace && !opts->auxtrace_mmap_pages) {
193	if (privileged) {
194	opts->auxtrace_mmap_pages = MiB(4) / page_size;
195	} else {
196	opts->auxtrace_mmap_pages = KiB(128) / page_size;
197	if (opts->mmap_pages == UINT_MAX)
198	opts->mmap_pages = KiB(256) / page_size;
199	}
200	}
201
202	/* Validate auxtrace_mmap_pages */
203	if (opts->auxtrace_mmap_pages) {
204	size_t sz = opts->auxtrace_mmap_pages * (size_t)page_size;
205	size_t min_sz;
206
207	if (opts->auxtrace_snapshot_mode)
208	min_sz = KiB(4);
209	else
210	min_sz = KiB(8);
211
212	if (sz < min_sz \|\| !is_power_of_2(sz)) {
213	pr_err("Invalid mmap size for Intel BTS: must be at least %zuKiB and a power of 2\n",
214	min_sz / 1024);
215	return -EINVAL;
216	}
217	}
218
219	if (intel_bts_evsel) {
220	/*
221	* To obtain the auxtrace buffer file descriptor, the auxtrace event
222	* must come first.
223	*/
224	perf_evlist__to_front(evlist, intel_bts_evsel);
225	/*
226	* In the case of per-cpu mmaps, we need the CPU on the
227	* AUX event.
228	*/
229	if (!cpu_map__empty(cpus))
230	perf_evsel__set_sample_bit(intel_bts_evsel, CPU);
231	}
232
233	/* Add dummy event to keep tracking */
234	if (opts->full_auxtrace) {
235	struct perf_evsel *tracking_evsel;
236	int err;
237
238	err = parse_events(evlist, "dummy:u", NULL);
239	if (err)
240	return err;
241
242	tracking_evsel = perf_evlist__last(evlist);
243
244	perf_evlist__set_tracking_event(evlist, tracking_evsel);
245
246	tracking_evsel->attr.freq = 0;
247	tracking_evsel->attr.sample_period = 1;
248	}
249
250	return 0;
251	}
252
253	static int intel_bts_parse_snapshot_options(struct auxtrace_record *itr,
254	struct record_opts *opts,
255	const char *str)
256	{
257	struct intel_bts_recording *btsr =
258	container_of(itr, struct intel_bts_recording, itr);
259	unsigned long long snapshot_size = 0;
260	char *endptr;
261
262	if (str) {
263	snapshot_size = strtoull(str, &endptr, 0);
264	if (*endptr \|\| snapshot_size > SIZE_MAX)
265	return -1;
266	}
267
268	opts->auxtrace_snapshot_mode = true;
269	opts->auxtrace_snapshot_size = snapshot_size;
270
271	btsr->snapshot_size = snapshot_size;
272
273	return 0;
274	}
275
276	static u64 intel_bts_reference(struct auxtrace_record *itr __maybe_unused)
277	{
278	return rdtsc();
279	}
280
281	static int intel_bts_alloc_snapshot_refs(struct intel_bts_recording *btsr,
282	int idx)
283	{
284	const size_t sz = sizeof(struct intel_bts_snapshot_ref);
285	int cnt = btsr->snapshot_ref_cnt, new_cnt = cnt * 2;
286	struct intel_bts_snapshot_ref *refs;
287
288	if (!new_cnt)
289	new_cnt = 16;
290
291	while (new_cnt <= idx)
292	new_cnt *= 2;
293
294	refs = calloc(new_cnt, sz);
295	if (!refs)
296	return -ENOMEM;
297
298	memcpy(refs, btsr->snapshot_refs, cnt * sz);
299
300	btsr->snapshot_refs = refs;
301	btsr->snapshot_ref_cnt = new_cnt;
302
303	return 0;
304	}
305
306	static void intel_bts_free_snapshot_refs(struct intel_bts_recording *btsr)
307	{
308	int i;
309
310	for (i = 0; i < btsr->snapshot_ref_cnt; i++)
311	zfree(&btsr->snapshot_refs[i].ref_buf);
312	zfree(&btsr->snapshot_refs);
313	}
314
315	static void intel_bts_recording_free(struct auxtrace_record *itr)
316	{
317	struct intel_bts_recording *btsr =
318	container_of(itr, struct intel_bts_recording, itr);
319
320	intel_bts_free_snapshot_refs(btsr);
321	free(btsr);
322	}
323
324	static int intel_bts_snapshot_start(struct auxtrace_record *itr)
325	{
326	struct intel_bts_recording *btsr =
327	container_of(itr, struct intel_bts_recording, itr);
328	struct perf_evsel *evsel;
329
e5cadb93	330	evlist__for_each_entry(btsr->evlist, evsel) {
d0170af7	331	if (evsel->attr.type == btsr->intel_bts_pmu->type)
d2190a80	332	return perf_evsel__disable(evsel);
d0170af7 AH	333	}
	334	return -EINVAL;
	335	}
	336
	337	static int intel_bts_snapshot_finish(struct auxtrace_record *itr)
	338	{
	339	struct intel_bts_recording *btsr =
	340	container_of(itr, struct intel_bts_recording, itr);
	341	struct perf_evsel *evsel;
	342
e5cadb93	343	evlist__for_each_entry(btsr->evlist, evsel) {
d0170af7	344	if (evsel->attr.type == btsr->intel_bts_pmu->type)
d2190a80	345	return perf_evsel__enable(evsel);
d0170af7 AH	346	}
	347	return -EINVAL;
	348	}
	349
	350	static bool intel_bts_first_wrap(u64 *data, size_t buf_size)
	351	{
	352	int i, a, b;
	353
	354	b = buf_size >> 3;
	355	a = b - 512;
	356	if (a < 0)
	357	a = 0;
	358
	359	for (i = a; i < b; i++) {
	360	if (data[i])
	361	return true;
	362	}
	363
	364	return false;
	365	}
	366
	367	static int intel_bts_find_snapshot(struct auxtrace_record *itr, int idx,
	368	struct auxtrace_mmap mm, unsigned char data,
	369	u64 head, u64 old)
	370	{
	371	struct intel_bts_recording *btsr =
	372	container_of(itr, struct intel_bts_recording, itr);
	373	bool wrapped;
	374	int err;
	375
	376	pr_debug3("%s: mmap index %d old head %zu new head %zu\n",
	377	__func__, idx, (size_t)old, (size_t)head);
	378
	379	if (idx >= btsr->snapshot_ref_cnt) {
	380	err = intel_bts_alloc_snapshot_refs(btsr, idx);
	381	if (err)
	382	goto out_err;
	383	}
	384
	385	wrapped = btsr->snapshot_refs[idx].wrapped;
	386	if (!wrapped && intel_bts_first_wrap((u64 *)data, mm->len)) {
	387	btsr->snapshot_refs[idx].wrapped = true;
	388	wrapped = true;
	389	}
	390
	391	/*
	392	* In full trace mode 'head' continually increases. However in snapshot
	393	* mode 'head' is an offset within the buffer. Here 'old' and 'head'
	394	* are adjusted to match the full trace case which expects that 'old' is
	395	* always less than 'head'.
	396	*/
	397	if (wrapped) {
	398	old = head;
	399	*head += mm->len;
	400	} else {
	401	if (mm->mask)
	402	*old &= mm->mask;
	403	else
	404	*old %= mm->len;
	405	if (old > head)
	406	*head += mm->len;
	407	}
	408
	409	pr_debug3("%s: wrap-around %sdetected, adjusted old head %zu adjusted new head %zu\n",
410	__func__, wrapped ? "" : "not ", (size_t)old, (size_t)head);
411
412	return 0;
413
414	out_err:
415	pr_err("%s: failed, error %d\n", __func__, err);
416	return err;
417	}
418
419	static int intel_bts_read_finish(struct auxtrace_record *itr, int idx)
420	{
421	struct intel_bts_recording *btsr =
422	container_of(itr, struct intel_bts_recording, itr);
423	struct perf_evsel *evsel;
424
e5cadb93	425	evlist__for_each_entry(btsr->evlist, evsel) {
d0170af7 AH	426	if (evsel->attr.type == btsr->intel_bts_pmu->type)
	427	return perf_evlist__enable_event_idx(btsr->evlist,
	428	evsel, idx);
	429	}
	430	return -EINVAL;
	431	}
	432
	433	struct auxtrace_record intel_bts_recording_init(int err)
	434	{
	435	struct perf_pmu *intel_bts_pmu = perf_pmu__find(INTEL_BTS_PMU_NAME);
	436	struct intel_bts_recording *btsr;
	437
	438	if (!intel_bts_pmu)
	439	return NULL;
	440
bd0c7a54 AH	441	if (setenv("JITDUMP_USE_ARCH_TIMESTAMP", "1", 1)) {
	442	*err = -errno;
	443	return NULL;
	444	}
	445
d0170af7 AH	446	btsr = zalloc(sizeof(struct intel_bts_recording));
	447	if (!btsr) {
	448	*err = -ENOMEM;
	449	return NULL;
	450	}
	451
	452	btsr->intel_bts_pmu = intel_bts_pmu;
	453	btsr->itr.recording_options = intel_bts_recording_options;
	454	btsr->itr.info_priv_size = intel_bts_info_priv_size;
	455	btsr->itr.info_fill = intel_bts_info_fill;
	456	btsr->itr.free = intel_bts_recording_free;
	457	btsr->itr.snapshot_start = intel_bts_snapshot_start;
	458	btsr->itr.snapshot_finish = intel_bts_snapshot_finish;
	459	btsr->itr.find_snapshot = intel_bts_find_snapshot;
	460	btsr->itr.parse_snapshot_options = intel_bts_parse_snapshot_options;
	461	btsr->itr.reference = intel_bts_reference;
	462	btsr->itr.read_finish = intel_bts_read_finish;
	463	btsr->itr.alignment = sizeof(struct branch);
	464	return &btsr->itr;
	465	}