On 15/08/2025 11:34, Athira Rajeev wrote:
> The powerpc PMU collecting Dispatch Trace Log (DTL) entries makes use of
> AUX support in perf infrastructure. The PMU driver has the functionality
> to collect trace entries in the aux buffer. On the tools side, this data
> is made available as PERF_RECORD_AUXTRACE records. This record is
> generated by "perf record" command. To enable the creation of
> PERF_RECORD_AUXTRACE, add functions to initialize auxtrace records ie
> "auxtrace_record__init()". Fill in fields for other callbacks like
> info_priv_size, info_fill, free, recording options etc. Define
> auxtrace_type as PERF_AUXTRACE_VPA_PMU. Add header file to define vpa
> dtl pmu specific details.
>
> Signed-off-by: Athira Rajeev <atraj...@linux.ibm.com>
> ---
> tools/perf/arch/powerpc/util/Build | 1 +
> tools/perf/arch/powerpc/util/auxtrace.c | 122 ++++++++++++++++++++++++
> tools/perf/util/auxtrace.c | 2 +
> tools/perf/util/auxtrace.h | 1 +
> tools/perf/util/powerpc-vpadtl.h | 26 +++++
> 5 files changed, 152 insertions(+)
> create mode 100644 tools/perf/arch/powerpc/util/auxtrace.c
> create mode 100644 tools/perf/util/powerpc-vpadtl.h
>
> diff --git a/tools/perf/arch/powerpc/util/Build
> b/tools/perf/arch/powerpc/util/Build
> index fdd6a77a3432..a5b0babd307e 100644
> --- a/tools/perf/arch/powerpc/util/Build
> +++ b/tools/perf/arch/powerpc/util/Build
> @@ -10,3 +10,4 @@ perf-util-$(CONFIG_LIBDW) += skip-callchain-idx.o
>
> perf-util-$(CONFIG_LIBUNWIND) += unwind-libunwind.o
> perf-util-$(CONFIG_LIBDW_DWARF_UNWIND) += unwind-libdw.o
> +perf-util-$(CONFIG_AUXTRACE) += auxtrace.o
> diff --git a/tools/perf/arch/powerpc/util/auxtrace.c
> b/tools/perf/arch/powerpc/util/auxtrace.c
> new file mode 100644
> index 000000000000..ec8ec601fd08
> --- /dev/null
> +++ b/tools/perf/arch/powerpc/util/auxtrace.c
> @@ -0,0 +1,122 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * VPA support
> + */
> +
> +#include <linux/kernel.h>
> +#include <linux/types.h>
> +#include <linux/bitops.h>
> +#include <linux/log2.h>
> +#include <time.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/auxtrace.h"
> +#include "../../util/powerpc-vpadtl.h"
It would be better to only add #includes when they are needed
> +#include "../../util/record.h"
> +#include <internal/lib.h> // page_size
> +
> +#define KiB(x) ((x) * 1024)
> +
> +static int
> +powerpc_vpadtl_parse_snapshot_options(struct auxtrace_record *itr
> __maybe_unused,
> + struct record_opts *opts __maybe_unused,
> + const char *str __maybe_unused)
> +{
> + return 0;
> +}
> +
> +static int
> +powerpc_vpadtl_recording_options(struct auxtrace_record *ar __maybe_unused,
> + struct evlist *evlist __maybe_unused,
> + struct record_opts *opts)
> +{
> + opts->full_auxtrace = true;
> +
> + /*
> + * Set auxtrace_mmap_pages to minimum
> + * two pages
> + */
> + if (!opts->auxtrace_mmap_pages) {
> + opts->auxtrace_mmap_pages = KiB(128) / page_size;
> + if (opts->mmap_pages == UINT_MAX)
> + opts->mmap_pages = KiB(256) / page_size;
> + }
> +
> + return 0;
> +}
> +
> +static size_t powerpc_vpadtl_info_priv_size(struct auxtrace_record *itr
> __maybe_unused,
> + struct evlist *evlist __maybe_unused)
> +{
> + return 0;
return VPADTL_AUXTRACE_PRIV_SIZE;
> +}
> +
> +static int
> +powerpc_vpadtl_info_fill(struct auxtrace_record *itr __maybe_unused,
> + struct perf_session *session __maybe_unused,
> + struct perf_record_auxtrace_info *auxtrace_info __maybe_unused,
auxtrace_info is not __maybe_unused
> + size_t priv_size __maybe_unused)
> +{
> + auxtrace_info->type = PERF_AUXTRACE_VPA_PMU;
> +
> + return 0;
> +}
> +
> +static u64 powerpc_vpadtl_reference(struct auxtrace_record *itr
> __maybe_unused)
> +{
> + return 0;
> +}
> +
> +static void powerpc_vpadtl_free(struct auxtrace_record *itr)
> +{
> + free(itr);
> +}
> +
> +struct auxtrace_record *auxtrace_record__init(struct evlist *evlist
> __maybe_unused,
evlist is not __maybe_unused
> + int *err)
> +{
> + struct auxtrace_record *aux;
> + struct evsel *pos;
> + char *pmu_name;
> + int found = 0;
> +
> + evlist__for_each_entry(evlist, pos) {
> + pmu_name = strdup(pos->name);
> + pmu_name = strtok(pmu_name, "/");
> + if (!strcmp(pmu_name, "vpa_dtl")) {
pmu_name is leaked but strstarts() could be used instead
of above
> + found = 1;
> + pos->needs_auxtrace_mmap = true;
> + break;
> + }
> + }
> +
> + if (!found)
> + return NULL;
> +
> + /*
> + * To obtain the auxtrace buffer file descriptor, the auxtrace event
> + * must come first.
> + */
> + evlist__to_front(pos->evlist, pos);
> +
> + aux = zalloc(sizeof(*aux));
> + if (aux == NULL) {
> + pr_debug("aux record is NULL\n");
> + *err = -ENOMEM;
> + return NULL;
> + }
> +
> + aux->parse_snapshot_options = powerpc_vpadtl_parse_snapshot_options;
Doesn't look like snapshot mode is supported, so
powerpc_vpadtl_parse_snapshot_options() is not needed
> + aux->recording_options = powerpc_vpadtl_recording_options;
> + aux->info_priv_size = powerpc_vpadtl_info_priv_size;
> + aux->info_fill = powerpc_vpadtl_info_fill;
> + aux->free = powerpc_vpadtl_free;
> + aux->reference = powerpc_vpadtl_reference;
reference is optional. powerpc_vpadtl_reference() stub is not needed
> + return aux;
> +}
> diff --git a/tools/perf/util/auxtrace.c b/tools/perf/util/auxtrace.c
> index ebd32f1b8f12..f587d386c5ef 100644
> --- a/tools/perf/util/auxtrace.c
> +++ b/tools/perf/util/auxtrace.c
> @@ -55,6 +55,7 @@
> #include "hisi-ptt.h"
> #include "s390-cpumsf.h"
> #include "util/mmap.h"
> +#include "powerpc-vpadtl.h"
Isn't needed yet
>
> #include <linux/ctype.h>
> #include "symbol/kallsyms.h"
> @@ -1393,6 +1394,7 @@ int perf_event__process_auxtrace_info(struct
> perf_session *session,
> case PERF_AUXTRACE_HISI_PTT:
> err = hisi_ptt_process_auxtrace_info(event, session);
> break;
> + case PERF_AUXTRACE_VPA_PMU:
> case PERF_AUXTRACE_UNKNOWN:
> default:
> return -EINVAL;
> diff --git a/tools/perf/util/auxtrace.h b/tools/perf/util/auxtrace.h
> index f001cbb68f8e..1f9ef473af77 100644
> --- a/tools/perf/util/auxtrace.h
> +++ b/tools/perf/util/auxtrace.h
> @@ -50,6 +50,7 @@ enum auxtrace_type {
> PERF_AUXTRACE_ARM_SPE,
> PERF_AUXTRACE_S390_CPUMSF,
> PERF_AUXTRACE_HISI_PTT,
> + PERF_AUXTRACE_VPA_PMU,
Everything else is called some variation of vpa dtl, so
PERF_AUXTRACE_VPA_DTL would seem a more consistent name
> };
>
> enum itrace_period_type {
> diff --git a/tools/perf/util/powerpc-vpadtl.h
> b/tools/perf/util/powerpc-vpadtl.h
> new file mode 100644
> index 000000000000..625172adaba5
> --- /dev/null
> +++ b/tools/perf/util/powerpc-vpadtl.h
> @@ -0,0 +1,26 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * VPA DTL PMU Support
> + */
> +
> +#ifndef INCLUDE__PERF_POWERPC_VPADTL_H__
> +#define INCLUDE__PERF_POWERPC_VPADTL_H__
> +
> +#define POWERPC_VPADTL_NAME "powerpc_vpadtl_"
> +
> +enum {
> + POWERPC_VPADTL_TYPE,
> + VPADTL_PER_CPU_MMAPS,
VPADTL_PER_CPU_MMAPS is never used
> + VPADTL_AUXTRACE_PRIV_MAX,
> +};
> +
> +#define VPADTL_AUXTRACE_PRIV_SIZE (VPADTL_AUXTRACE_PRIV_MAX * sizeof(u64))
> +
> +union perf_event;
> +struct perf_session;
> +struct perf_pmu;
> +
> +int powerpc_vpadtl_process_auxtrace_info(union perf_event *event,
> + struct perf_session *session);
None of these definitions are used in this patch, although probably
VPADTL_AUXTRACE_PRIV_SIZE should be.
It would be better to add definitions only when they are needed.
> +
> +#endif
