From: German Gomez german.gomez@arm.com
mainline inclusion from mainline-v5.16-rc1 commit 0901b5602872 category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I4NGPV CVE: NA
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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: James Clark james.clark@arm.com Reviewed-by: Leo Yan leo.yan@linaro.org Signed-off-by: German Gomez german.gomez@arm.com Acked-by: Namhyung 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: Leo Yan leo.yan@linaro.org Signed-off-by: Arnaldo Carvalho de Melo acme@redhat.com Signed-off-by: Wei Li liwei391@huawei.com Reviewed-by: Yang Jihong yangjihong1@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- tools/perf/arch/arm64/util/arm-spe.c | 130 +++++++++++++++++++++++++++ 1 file changed, 130 insertions(+)
diff --git a/tools/perf/arch/arm64/util/arm-spe.c b/tools/perf/arch/arm64/util/arm-spe.c index 02fe1345b85c..1e545237391b 100644 --- a/tools/perf/arch/arm64/util/arm-spe.c +++ b/tools/perf/arch/arm64/util/arm-spe.c @@ -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;