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Message-Id: <20220201214056.702854-1-robh@kernel.org>
Date: Tue, 1 Feb 2022 15:40:56 -0600
From: Rob Herring <robh@...nel.org>
To: Will Deacon <will@...nel.org>,
Peter Zijlstra <peterz@...radead.org>,
Ingo Molnar <mingo@...hat.com>,
Arnaldo Carvalho de Melo <acme@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
Jiri Olsa <jolsa@...hat.com>,
Namhyung Kim <namhyung@...nel.org>
Cc: Masayoshi Mizuma <m.mizuma@...fujitsu.com>,
linux-perf-users@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v9] libperf: Add arm64 support to perf_mmap__read_self()
Add the arm64 variants for read_perf_counter() and read_timestamp().
Unfortunately the counter number is encoded into the instruction, so the
code is a bit verbose to enumerate all possible counters.
Tested-by: Masayoshi Mizuma <m.mizuma@...fujitsu.com>
Signed-off-by: Rob Herring <robh@...nel.org>
---
Arm64 kernel support landed in 5.17, but the corresponding libperf
support didn't get picked up.
v9:
- Rebase on v5.17-rc
- Add Tested-by
v8:
- Set attr.config1 to request user access on arm64
v7:
- Move enabling of libperf user read test for arm64 to this patch
---
tools/lib/perf/mmap.c | 98 +++++++++++++++++++++++++++++++
tools/lib/perf/tests/test-evsel.c | 5 +-
2 files changed, 102 insertions(+), 1 deletion(-)
diff --git a/tools/lib/perf/mmap.c b/tools/lib/perf/mmap.c
index f7ee07cb5818..0d1634cedf44 100644
--- a/tools/lib/perf/mmap.c
+++ b/tools/lib/perf/mmap.c
@@ -13,6 +13,7 @@
#include <internal/lib.h>
#include <linux/kernel.h>
#include <linux/math64.h>
+#include <linux/stringify.h>
#include "internal.h"
void perf_mmap__init(struct perf_mmap *map, struct perf_mmap *prev,
@@ -294,6 +295,103 @@ static u64 read_timestamp(void)
return low | ((u64)high) << 32;
}
+#elif defined(__aarch64__)
+#define read_sysreg(r) ({ \
+ u64 __val; \
+ asm volatile("mrs %0, " __stringify(r) : "=r" (__val)); \
+ __val; \
+})
+
+static u64 read_pmccntr(void)
+{
+ return read_sysreg(pmccntr_el0);
+}
+
+#define PMEVCNTR_READ(idx) \
+ static u64 read_pmevcntr_##idx(void) { \
+ return read_sysreg(pmevcntr##idx##_el0); \
+ }
+
+PMEVCNTR_READ(0);
+PMEVCNTR_READ(1);
+PMEVCNTR_READ(2);
+PMEVCNTR_READ(3);
+PMEVCNTR_READ(4);
+PMEVCNTR_READ(5);
+PMEVCNTR_READ(6);
+PMEVCNTR_READ(7);
+PMEVCNTR_READ(8);
+PMEVCNTR_READ(9);
+PMEVCNTR_READ(10);
+PMEVCNTR_READ(11);
+PMEVCNTR_READ(12);
+PMEVCNTR_READ(13);
+PMEVCNTR_READ(14);
+PMEVCNTR_READ(15);
+PMEVCNTR_READ(16);
+PMEVCNTR_READ(17);
+PMEVCNTR_READ(18);
+PMEVCNTR_READ(19);
+PMEVCNTR_READ(20);
+PMEVCNTR_READ(21);
+PMEVCNTR_READ(22);
+PMEVCNTR_READ(23);
+PMEVCNTR_READ(24);
+PMEVCNTR_READ(25);
+PMEVCNTR_READ(26);
+PMEVCNTR_READ(27);
+PMEVCNTR_READ(28);
+PMEVCNTR_READ(29);
+PMEVCNTR_READ(30);
+
+/*
+ * Read a value direct from PMEVCNTR<idx>
+ */
+static u64 read_perf_counter(unsigned int counter)
+{
+ static u64 (* const read_f[])(void) = {
+ read_pmevcntr_0,
+ read_pmevcntr_1,
+ read_pmevcntr_2,
+ read_pmevcntr_3,
+ read_pmevcntr_4,
+ read_pmevcntr_5,
+ read_pmevcntr_6,
+ read_pmevcntr_7,
+ read_pmevcntr_8,
+ read_pmevcntr_9,
+ read_pmevcntr_10,
+ read_pmevcntr_11,
+ read_pmevcntr_13,
+ read_pmevcntr_12,
+ read_pmevcntr_14,
+ read_pmevcntr_15,
+ read_pmevcntr_16,
+ read_pmevcntr_17,
+ read_pmevcntr_18,
+ read_pmevcntr_19,
+ read_pmevcntr_20,
+ read_pmevcntr_21,
+ read_pmevcntr_22,
+ read_pmevcntr_23,
+ read_pmevcntr_24,
+ read_pmevcntr_25,
+ read_pmevcntr_26,
+ read_pmevcntr_27,
+ read_pmevcntr_28,
+ read_pmevcntr_29,
+ read_pmevcntr_30,
+ read_pmccntr
+ };
+
+ if (counter < ARRAY_SIZE(read_f))
+ return (read_f[counter])();
+
+ return 0;
+}
+
+static u64 read_timestamp(void) { return read_sysreg(cntvct_el0); }
+
#else
static u64 read_perf_counter(unsigned int counter __maybe_unused) { return 0; }
static u64 read_timestamp(void) { return 0; }
diff --git a/tools/lib/perf/tests/test-evsel.c b/tools/lib/perf/tests/test-evsel.c
index 33ae9334861a..89be89afb24d 100644
--- a/tools/lib/perf/tests/test-evsel.c
+++ b/tools/lib/perf/tests/test-evsel.c
@@ -130,6 +130,9 @@ static int test_stat_user_read(int event)
struct perf_event_attr attr = {
.type = PERF_TYPE_HARDWARE,
.config = event,
+#ifdef __aarch64__
+ .config1 = 0x2, /* Request user access */
+#endif
};
int err, i;
@@ -150,7 +153,7 @@ static int test_stat_user_read(int event)
pc = perf_evsel__mmap_base(evsel, 0, 0);
__T("failed to get mmapped address", pc);
-#if defined(__i386__) || defined(__x86_64__)
+#if defined(__i386__) || defined(__x86_64__) || defined(__aarch64__)
__T("userspace counter access not supported", pc->cap_user_rdpmc);
__T("userspace counter access not enabled", pc->index);
__T("userspace counter width not set", pc->pmc_width >= 32);
--
2.32.0
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