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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-05-06 01:02:30 +0000
commit76cb841cb886eef6b3bee341a2266c76578724ad (patch)
treef5892e5ba6cc11949952a6ce4ecbe6d516d6ce58 /tools/perf/arch/x86/util/tsc.c
parentInitial commit. (diff)
downloadlinux-76cb841cb886eef6b3bee341a2266c76578724ad.tar.xz
linux-76cb841cb886eef6b3bee341a2266c76578724ad.zip
Adding upstream version 4.19.249.upstream/4.19.249
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/perf/arch/x86/util/tsc.c')
-rw-r--r--tools/perf/arch/x86/util/tsc.c82
1 files changed, 82 insertions, 0 deletions
diff --git a/tools/perf/arch/x86/util/tsc.c b/tools/perf/arch/x86/util/tsc.c
new file mode 100644
index 000000000..950539f9a
--- /dev/null
+++ b/tools/perf/arch/x86/util/tsc.c
@@ -0,0 +1,82 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <stdbool.h>
+#include <errno.h>
+
+#include <linux/stddef.h>
+#include <linux/perf_event.h>
+
+#include "../../perf.h"
+#include <linux/types.h>
+#include "../../util/debug.h"
+#include "../../util/tsc.h"
+
+int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc,
+ struct perf_tsc_conversion *tc)
+{
+ bool cap_user_time_zero;
+ u32 seq;
+ int i = 0;
+
+ while (1) {
+ seq = pc->lock;
+ rmb();
+ tc->time_mult = pc->time_mult;
+ tc->time_shift = pc->time_shift;
+ tc->time_zero = pc->time_zero;
+ cap_user_time_zero = pc->cap_user_time_zero;
+ rmb();
+ if (pc->lock == seq && !(seq & 1))
+ break;
+ if (++i > 10000) {
+ pr_debug("failed to get perf_event_mmap_page lock\n");
+ return -EINVAL;
+ }
+ }
+
+ if (!cap_user_time_zero)
+ return -EOPNOTSUPP;
+
+ return 0;
+}
+
+u64 rdtsc(void)
+{
+ unsigned int low, high;
+
+ asm volatile("rdtsc" : "=a" (low), "=d" (high));
+
+ return low | ((u64)high) << 32;
+}
+
+int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc,
+ struct perf_tool *tool,
+ perf_event__handler_t process,
+ struct machine *machine)
+{
+ union perf_event event = {
+ .time_conv = {
+ .header = {
+ .type = PERF_RECORD_TIME_CONV,
+ .size = sizeof(struct time_conv_event),
+ },
+ },
+ };
+ struct perf_tsc_conversion tc;
+ int err;
+
+ if (!pc)
+ return 0;
+ err = perf_read_tsc_conversion(pc, &tc);
+ if (err == -EOPNOTSUPP)
+ return 0;
+ if (err)
+ return err;
+
+ pr_debug2("Synthesizing TSC conversion information\n");
+
+ event.time_conv.time_mult = tc.time_mult;
+ event.time_conv.time_shift = tc.time_shift;
+ event.time_conv.time_zero = tc.time_zero;
+
+ return process(tool, &event, NULL, machine);
+}