Commit f14ab50e authored by German Gomez's avatar German Gomez Committed by Zheng Zengkai
Browse files

perf arm-spe: Add snapshot mode support 

mainline inclusion
from mainline-v5.16-rc1
commit 0901b560
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4NGPV


CVE: NA

-------------------------------------------------

This patch enables support for snapshot mode of arm_spe events,
including the implementation of the necessary callbacks (excluding
find_snapshot, which is to be included in a followup commit).

Reviewed-by: default avatarJames Clark <james.clark@arm.com>
Reviewed-by: default avatarLeo Yan <leo.yan@linaro.org>
Signed-off-by: default avatarGerman Gomez <german.gomez@arm.com>
Acked-by: default avatarNamhyung Kim <namhyung@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: John Garry <john.garry@huawei.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org
Link: https://lore.kernel.org/r/20211109163009.92072-2-german.gomez@arm.com


Tested-by: default avatarLeo Yan <leo.yan@linaro.org>
Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: default avatarWei Li <liwei391@huawei.com>
Reviewed-by: default avatarYang Jihong <yangjihong1@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 15374280

tools/perf/arch/arm64/util/arm-spe.c

+130 −0
Original line number Diff line number Diff line
@@ -84,6 +84,55 @@ static int arm_spe_info_fill(struct auxtrace_record *itr, 
	return 0;

}



static void

arm_spe_snapshot_resolve_auxtrace_defaults(struct record_opts *opts,

					   bool privileged)

{

	/*

	 * The default snapshot size is the auxtrace mmap size. If neither auxtrace mmap size nor

	 * snapshot size is specified, then the default is 4MiB for privileged users, 128KiB for

	 * unprivileged users.

	 *

	 * The default auxtrace mmap size is 4MiB/page_size for privileged users, 128KiB for

	 * unprivileged users. If an unprivileged user does not specify mmap pages, the mmap pages

	 * will be reduced from the default 512KiB/page_size to 256KiB/page_size, otherwise the

	 * user is likely to get an error as they exceed their mlock limmit.

	 */



	/*

	 * No size were given to '-S' or '-m,', so go with the default

	 */

	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;

	}



	/*

	 * '-m,xyz' was specified but no snapshot size, so make the snapshot size as big as the

	 * auxtrace mmap area.

	 */

	if (!opts->auxtrace_snapshot_size)

		opts->auxtrace_snapshot_size = opts->auxtrace_mmap_pages * (size_t)page_size;



	/*

	 * '-Sxyz' was specified but no auxtrace mmap area, so make the auxtrace mmap area big

	 * enough to fit the requested snapshot 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);

	}

}



static int arm_spe_recording_options(struct auxtrace_record *itr,

				     struct evlist *evlist,

				     struct record_opts *opts)
@@ -115,6 +164,36 @@ static int arm_spe_recording_options(struct auxtrace_record *itr, 
	if (!opts->full_auxtrace)

		return 0;



	/*

	 * we are in snapshot mode.

	 */

	if (opts->auxtrace_snapshot_mode) {

		/*

		 * Command arguments '-Sxyz' and/or '-m,xyz' are missing, so fill those in with

		 * default values.

		 */

		if (!opts->auxtrace_snapshot_size || !opts->auxtrace_mmap_pages)

			arm_spe_snapshot_resolve_auxtrace_defaults(opts, privileged);



		/*

		 * Snapshot size can't be bigger than the auxtrace area.

		 */

		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;

		}



		/*

		 * Something went wrong somewhere - this shouldn't happen.

		 */

		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;

		}

	}



	/* We are in full trace mode but '-m,xyz' wasn't specified */

	if (!opts->auxtrace_mmap_pages) {

		if (privileged) {
@@ -138,6 +217,9 @@ static int arm_spe_recording_options(struct auxtrace_record *itr, 
		}

	}



	if (opts->auxtrace_snapshot_mode)

		pr_debug2("%sx snapshot size: %zu\n", ARM_SPE_PMU_NAME,

			  opts->auxtrace_snapshot_size);



	/*

	 * To obtain the auxtrace buffer file descriptor, the auxtrace event
@@ -172,6 +254,51 @@ static int arm_spe_recording_options(struct auxtrace_record *itr, 
	return 0;

}



static int arm_spe_parse_snapshot_options(struct auxtrace_record *itr __maybe_unused,

					 struct record_opts *opts,

					 const char *str)

{

	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;



	return 0;

}



static int arm_spe_snapshot_start(struct auxtrace_record *itr)

{

	struct arm_spe_recording *ptr =

			container_of(itr, struct arm_spe_recording, itr);

	struct evsel *evsel;



	evlist__for_each_entry(ptr->evlist, evsel) {

		if (evsel->core.attr.type == ptr->arm_spe_pmu->type)

			return evsel__disable(evsel);

	}

	return -EINVAL;

}



static int arm_spe_snapshot_finish(struct auxtrace_record *itr)

{

	struct arm_spe_recording *ptr =

			container_of(itr, struct arm_spe_recording, itr);

	struct evsel *evsel;



	evlist__for_each_entry(ptr->evlist, evsel) {

		if (evsel->core.attr.type == ptr->arm_spe_pmu->type)

			return evsel__enable(evsel);

	}

	return -EINVAL;

}



static u64 arm_spe_reference(struct auxtrace_record *itr __maybe_unused)

{

	struct timespec ts;
@@ -207,6 +334,9 @@ struct auxtrace_record *arm_spe_recording_init(int *err, 


	sper->arm_spe_pmu = arm_spe_pmu;

	sper->itr.pmu = arm_spe_pmu;

	sper->itr.snapshot_start = arm_spe_snapshot_start;

	sper->itr.snapshot_finish = arm_spe_snapshot_finish;

	sper->itr.parse_snapshot_options = arm_spe_parse_snapshot_options;

	sper->itr.recording_options = arm_spe_recording_options;

	sper->itr.info_priv_size = arm_spe_info_priv_size;

	sper->itr.info_fill = arm_spe_info_fill;