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@jp.fujitsu.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Tested-by: John Garry <john.garry@huawei.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20220201214056.702854-1-robh@kernel.org
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Will Deacon <will@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-perf-users@vger.kernel.org

diff --git a/tools/lib/perf/mmap.c b/tools/lib/perf/mmap.c
index f7ee07c..0d1634c 100644 (file)
--- 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 33ae933..89be89a 100644 (file)
--- 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);