kernel_5.10 no rt

hc

2023-12-11 6778948f9de86c3cfaf36725a7c87dcff9ba247f

 kernel/tools/perf/util/tsc.c
..
..
@@ -1,7 +1,16 @@
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 // SPDX-License-Identifier: GPL-2.0
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+#include <errno.h>
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+
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 #include <linux/compiler.h>
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+#include <linux/perf_event.h>
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+#include <linux/stddef.h>
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 #include <linux/types.h>
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+#include <asm/barrier.h>
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+
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+#include "event.h"
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+#include "synthetic-events.h"
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+#include "debug.h"
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 #include "tsc.h"
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 u64 perf_time_to_tsc(u64 ns, struct perf_tsc_conversion *tc)
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@@ -19,12 +28,84 @@
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 {
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 	u64 quot, rem;
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+	if (tc->cap_user_time_short)
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+		cyc = tc->time_cycles +
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+			((cyc - tc->time_cycles) & tc->time_mask);
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+
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 	quot = cyc >> tc->time_shift;
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 	rem  = cyc & (((u64)1 << tc->time_shift) - 1);
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 	return tc->time_zero + quot * tc->time_mult +
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 	       ((rem * tc->time_mult) >> tc->time_shift);
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 }
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+int perf_read_tsc_conversion(const struct perf_event_mmap_page *pc,
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+			     struct perf_tsc_conversion *tc)
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+{
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+	u32 seq;
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+	int i = 0;
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+
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+	while (1) {
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+		seq = pc->lock;
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+		rmb();
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+		tc->time_mult = pc->time_mult;
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+		tc->time_shift = pc->time_shift;
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+		tc->time_zero = pc->time_zero;
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+		tc->time_cycles = pc->time_cycles;
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+		tc->time_mask = pc->time_mask;
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+		tc->cap_user_time_zero = pc->cap_user_time_zero;
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+		tc->cap_user_time_short	= pc->cap_user_time_short;
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+		rmb();
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+		if (pc->lock == seq && !(seq & 1))
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+			break;
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+		if (++i > 10000) {
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+			pr_debug("failed to get perf_event_mmap_page lock\n");
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+			return -EINVAL;
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+		}
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+	}
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+
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+	if (!tc->cap_user_time_zero)
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+		return -EOPNOTSUPP;
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+
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+	return 0;
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+}
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+
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+int perf_event__synth_time_conv(const struct perf_event_mmap_page *pc,
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+				struct perf_tool *tool,
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+				perf_event__handler_t process,
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+				struct machine *machine)
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+{
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+	union perf_event event = {
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+		.time_conv = {
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+			.header = {
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+				.type = PERF_RECORD_TIME_CONV,
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+				.size = sizeof(struct perf_record_time_conv),
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+			},
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+		},
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+	};
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+	struct perf_tsc_conversion tc;
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+	int err;
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+
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+	if (!pc)
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+		return 0;
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+	err = perf_read_tsc_conversion(pc, &tc);
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+	if (err == -EOPNOTSUPP)
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+		return 0;
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+	if (err)
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+		return err;
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+
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+	pr_debug2("Synthesizing TSC conversion information\n");
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+
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+	event.time_conv.time_mult  = tc.time_mult;
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+	event.time_conv.time_shift = tc.time_shift;
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+	event.time_conv.time_zero  = tc.time_zero;
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+	event.time_conv.time_cycles = tc.time_cycles;
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+	event.time_conv.time_mask = tc.time_mask;
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+	event.time_conv.cap_user_time_zero = tc.cap_user_time_zero;
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+	event.time_conv.cap_user_time_short = tc.cap_user_time_short;
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+
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+	return process(tool, &event, NULL, machine);
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+}
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+
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 u64 __weak rdtsc(void)
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 {
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 	return 0;