[PATCH 1/2] perf alpha: Decode ProfileMe raw samples

[Matt Turner <mattst88@gmail.com>]

The Alpha cpu PMU attaches struct alpha_profileme_sample to each
ProfileMe sample as PERF_SAMPLE_RAW data: the profiled instruction's
PMPC along with the I_STAT and PCTR_CTL status that says what happened
to it.

Decode it in perf report -D and perf script -D the way AMD IBS raw data
is decoded, naming the trap from TRAP_TYPE when TRP is set and from the
PALcode entry offset in PMPC for redirect traps, which TRAP_TYPE does
not report.

Copy the uapi header that defines the struct into tools/arch and add it
to check-headers.sh.

Signed-off-by: Matt Turner <mattst88@gmail.com>
---
 tools/arch/alpha/include/uapi/asm/perf_event.h |  27 +++++
 tools/perf/check-headers.sh                    |   1 +
 tools/perf/util/Build                          |   1 +
 tools/perf/util/alpha-sample-raw.c             | 133 +++++++++++++++++++++++++
 tools/perf/util/sample-raw.c                   |   2 +
 tools/perf/util/sample-raw.h                   |   2 +
 6 files changed, 166 insertions(+)

diff --git a/tools/arch/alpha/include/uapi/asm/perf_event.h b/tools/arch/alpha/include/uapi/asm/perf_event.h
new file mode 100644
index 000000000000..0cb7d6f3cb15
--- /dev/null
+++ b/tools/arch/alpha/include/uapi/asm/perf_event.h
@@ -0,0 +1,27 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#ifndef _UAPI_ASM_ALPHA_PERF_EVENT_H
+#define _UAPI_ASM_ALPHA_PERF_EVENT_H
+
+#include <linux/types.h>
+
+/*
+ * PERF_SAMPLE_RAW payload of a ProfileMe sample from the cpu PMU.
+ *
+ * pmpc, i_stat and pctr_ctl are the values of the PMPC, I_STAT and
+ * PCTR_CTL registers when the ProfileMe window closed. i_stat holds only
+ * bits 40:30 and pctr_ctl only bits 47:0. See the EV67/EV68 Hardware
+ * Reference Manuals for the field layout.
+ *
+ * Fields may be added to the end in later versions.
+ */
+#define ALPHA_PROFILEME_SAMPLE_VERSION	1
+
+struct alpha_profileme_sample {
+	__u32 version;
+	__u32 reserved;
+	__u64 pmpc;
+	__u64 i_stat;
+	__u64 pctr_ctl;
+};
+
+#endif /* _UAPI_ASM_ALPHA_PERF_EVENT_H */
diff --git a/tools/perf/check-headers.sh b/tools/perf/check-headers.sh
index 531c0e0e84df..de66bb148754 100755
--- a/tools/perf/check-headers.sh
+++ b/tools/perf/check-headers.sh
@@ -36,6 +36,7 @@ declare -a FILES=(
   "arch/x86/include/asm/msr-index.h"
   "arch/x86/lib/x86-opcode-map.txt"
   "arch/x86/tools/gen-insn-attr-x86.awk"
+  "arch/alpha/include/uapi/asm/perf_event.h"
   "arch/arm/include/uapi/asm/perf_regs.h"
   "arch/arm64/include/uapi/asm/perf_regs.h"
   "arch/loongarch/include/uapi/asm/perf_regs.h"
diff --git a/tools/perf/util/Build b/tools/perf/util/Build
index 2c1f880c4c47..2ab63bbe4a05 100644
--- a/tools/perf/util/Build
+++ b/tools/perf/util/Build
@@ -77,6 +77,7 @@ perf-util-y += sample.o
 perf-util-y += sample-raw.o
 perf-util-y += s390-sample-raw.o
 perf-util-y += amd-sample-raw.o
+perf-util-y += alpha-sample-raw.o
 perf-util-y += ordered-events.o
 perf-util-y += namespaces.o
 perf-util-y += comm.o
diff --git a/tools/perf/util/alpha-sample-raw.c b/tools/perf/util/alpha-sample-raw.c
new file mode 100644
index 000000000000..22cf95be93e3
--- /dev/null
+++ b/tools/perf/util/alpha-sample-raw.c
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Alpha specific. Provide textual annotation for ProfileMe raw sample data.
+ */
+
+#include <stdio.h>
+#include <linux/perf_event.h>
+
+#include "../../arch/alpha/include/uapi/asm/perf_event.h"
+
+#include "evlist.h"
+#include "evsel.h"
+#include "sample-raw.h"
+#include "util/sample.h"
+
+/* I_STAT */
+#define I_STAT_OVR(x)		(((x) >> 30) & 0x7)
+#define I_STAT_ICM(x)		(((x) >> 33) & 0x1)
+#define I_STAT_TRAP_TYPE(x)	(((x) >> 34) & 0xf)
+#define I_STAT_LSO(x)		(((x) >> 38) & 0x1)
+#define I_STAT_TRP(x)		(((x) >> 39) & 0x1)
+#define I_STAT_MIS(x)		(((x) >> 40) & 0x1)
+
+/* PCTR_CTL */
+#define PCTR_CTL_TAK(x)		((x) & 0x1)
+#define PCTR_CTL_VAL(x)		(((x) >> 1) & 0x1)
+#define PCTR_CTL_SL1(x)		(((x) >> 2) & 0x3)
+#define PCTR_CTL_SL0(x)		(((x) >> 4) & 0x1)
+#define PCTR_CTL_PCTR1(x)	(((x) >> 6) & 0xfffff)
+#define PCTR_CTL_KILLED(x)	(((x) >> 26) & 0x1)
+#define PCTR_CTL_STALLED(x)	(((x) >> 27) & 0x1)
+#define PCTR_CTL_PCTR0(x)	(((x) >> 28) & 0xfffff)
+
+/* PMPC */
+#define PMPC_PAL(x)		((x) & 0x1)
+#define PMPC_PAL_OFFSET(x)	((x) & 0x7fff)
+
+static const char * const trap_type_names[16] = {
+	[0]  = "replay",
+	[2]  = "DTB double miss (3 level)",
+	[3]  = "DTB double miss (4 level)",
+	[4]  = "FP disabled",
+	[5]  = "unaligned",
+	[6]  = "DTB single miss",
+	[7]  = "Dstream fault",
+	[8]  = "OPCDEC",
+	[10] = "machine check",
+	[12] = "arithmetic",
+	[14] = "MT_FPCR",
+	[15] = "reset",
+};
+
+/* What PCTR1 counts during the window, by SL1. */
+static const char * const pctr1_names[4] = {
+	"cycles",
+	"retire delay",
+	"bcache misses",
+	"mbox replays",
+};
+
+static const char *trap_name(__u64 i_stat, __u64 pmpc)
+{
+	const char *name;
+
+	/* Redirect traps leave TRAP_TYPE alone and are named by PMPC. */
+	if (PMPC_PAL(pmpc)) {
+		switch (PMPC_PAL_OFFSET(pmpc)) {
+		case 0x481:
+			return "Istream access violation";
+		case 0x581:
+			return "ITB miss";
+		case 0x681:
+			return "interrupt";
+		default:
+			break;
+		}
+	}
+	if (!I_STAT_TRP(i_stat) || I_STAT_MIS(i_stat))
+		return "none";
+	name = trap_type_names[I_STAT_TRAP_TYPE(i_stat)];
+	return name ? name : "other (see PMPC)";
+}
+
+static bool is_profileme_sample(struct evlist *evlist, union perf_event *event,
+				struct perf_sample *sample)
+{
+	const struct alpha_profileme_sample *pm = sample->raw_data;
+	struct evsel *evsel;
+
+	if (sample->raw_size < sizeof(*pm))
+		return false;
+
+	evsel = evlist__event2evsel(evlist, event);
+	if (!evsel)
+		return false;
+	if (evsel->core.attr.type != PERF_TYPE_HARDWARE &&
+	    evsel->core.attr.type != PERF_TYPE_RAW)
+		return false;
+
+	return pm->version >= ALPHA_PROFILEME_SAMPLE_VERSION;
+}
+
+void evlist__alpha_sample_raw(struct evlist *evlist, union perf_event *event,
+			      struct perf_sample *sample)
+{
+	const struct alpha_profileme_sample *pm;
+	unsigned long long i_stat, ctl, pmpc;
+
+	if (event->header.type != PERF_RECORD_SAMPLE ||
+	    !is_profileme_sample(evlist, event, sample))
+		return;
+
+	pm = sample->raw_data;
+	i_stat = pm->i_stat;
+	ctl = pm->pctr_ctl;
+	pmpc = pm->pmpc;
+
+	printf("ProfileMe PMPC:\t%016llx %s trap %s%s\n",
+	       pmpc, PMPC_PAL(pmpc) ? "PAL" : (pmpc >> 63 ? "kernel" : "user"),
+	       trap_name(i_stat, pmpc),
+	       I_STAT_TRP(i_stat) && I_STAT_MIS(i_stat) ? " mispredicted" : "");
+	printf("ProfileMe I_STAT:\t%016llx TRP %d MIS %d LSO %d TrapType %d ICM %d OVR %d\n",
+	       i_stat, (int)I_STAT_TRP(i_stat), (int)I_STAT_MIS(i_stat),
+	       (int)I_STAT_LSO(i_stat), (int)I_STAT_TRAP_TYPE(i_stat),
+	       (int)I_STAT_ICM(i_stat), (int)I_STAT_OVR(i_stat));
+	printf("ProfileMe PCTR_CTL:\t%016llx VAL %d TAK %d Stalled %d Killed %d",
+	       ctl, (int)PCTR_CTL_VAL(ctl), (int)PCTR_CTL_TAK(ctl),
+	       (int)PCTR_CTL_STALLED(ctl), (int)PCTR_CTL_KILLED(ctl));
+	printf(" SL0 %d SL1 %d PCTR0 %d PCTR1 %d (%s)\n",
+	       (int)PCTR_CTL_SL0(ctl), (int)PCTR_CTL_SL1(ctl),
+	       (int)PCTR_CTL_PCTR0(ctl), (int)PCTR_CTL_PCTR1(ctl),
+	       pctr1_names[PCTR_CTL_SL1(ctl)]);
+}
diff --git a/tools/perf/util/sample-raw.c b/tools/perf/util/sample-raw.c
index f5ae9f468983..f765429a481d 100644
--- a/tools/perf/util/sample-raw.c
+++ b/tools/perf/util/sample-raw.c
@@ -19,6 +19,8 @@ void evlist__init_trace_event_sample_raw(struct evlist *evlist, struct perf_env
 
 	if (e_machine == EM_S390) {
 		evlist__set_trace_event_sample_raw(evlist, evlist__s390_sample_raw);
+	} else if (e_machine == EM_ALPHA) {
+		evlist__set_trace_event_sample_raw(evlist, evlist__alpha_sample_raw);
 	} else if (e_machine == EM_X86_64 || e_machine == EM_386) {
 		const char *cpuid = perf_env__cpuid(env);
 
diff --git a/tools/perf/util/sample-raw.h b/tools/perf/util/sample-raw.h
index c8d38c841c8c..8df0bd3d02aa 100644
--- a/tools/perf/util/sample-raw.h
+++ b/tools/perf/util/sample-raw.h
@@ -14,6 +14,8 @@ void evlist__s390_sample_raw(struct evlist *evlist, union perf_event *event,
 bool evlist__has_amd_ibs(struct evlist *evlist);
 void evlist__amd_sample_raw(struct evlist *evlist, union perf_event *event,
 			    struct perf_sample *sample);
+void evlist__alpha_sample_raw(struct evlist *evlist, union perf_event *event,
+			      struct perf_sample *sample);
 void evlist__init_trace_event_sample_raw(struct evlist *evlist, struct perf_env *env);
 
 #endif /* __SAMPLE_RAW_H */

-- 
2.55.0