From: Wilco Dijkstra <Wilco.Dijkstra@arm.com>
To: 'GNU C Library' <libc-alpha@sourceware.org>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Subject: [PATCH] AArch64: Add hp-timing.h
Date: Mon, 28 Jun 2021 10:11:28 +0000 [thread overview]
Message-ID: <VE1PR08MB5599E9E405FE180BD3ACE2F283039@VE1PR08MB5599.eurprd08.prod.outlook.com> (raw)
Add hp-timing.h using the cntcvt_el0 counter. Return timing in nanoseconds
so it is fully compatible with generic hp-timing. Don't set HP_TIMING_INLINE
in the dynamic linker since very old kernels may not handle cntcvt correctly.
---
diff --git a/sysdeps/aarch64/hp-timing.h b/sysdeps/aarch64/hp-timing.h
new file mode 100644
index 0000000000000000000000000000000000000000..f9822e725c227b3b57d508dc7d44cd7d2d04faf4
--- /dev/null
+++ b/sysdeps/aarch64/hp-timing.h
@@ -0,0 +1,47 @@
+/* High precision, low overhead timing functions. AArch64 version.
+ Copyright (C) 2021 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <https://www.gnu.org/licenses/>. */
+
+#ifndef _HP_TIMING_H
+#define _HP_TIMING_H 1
+
+#include <time.h>
+#include <stdint.h>
+#include <hp-timing-common.h>
+#include <libc-symbols.h>
+
+/* Don't use inline timer in ld.so. */
+#if IS_IN(rtld)
+# define HP_TIMING_INLINE (0)
+#else
+# define HP_TIMING_INLINE (1)
+#endif
+
+typedef uint64_t hp_timing_t;
+
+#define HP_TIMING_NOW(var) \
+ __asm__ __volatile__ ("isb; mrs %0, cntvct_el0" : "=r" (var))
+
+/* Compute elapsed time in nanoseconds. */
+#undef HP_TIMING_DIFF
+#define HP_TIMING_DIFF(Diff, Start, End) \
+({ hp_timing_t freq; \
+ __asm__ __volatile__ ("mrs %0, cntfrq_el0" : "=r" (freq)); \
+ (Diff) = ((End) - (Start)) * (UINT64_C(1000000000) / freq); \
+})
+
+#endif /* hp-timing.h */
next reply other threads:[~2021-06-28 10:12 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-28 10:11 Wilco Dijkstra [this message]
2021-06-28 10:20 ` Florian Weimer
2021-06-28 10:53 ` Wilco Dijkstra
2021-06-28 11:06 ` Florian Weimer
2021-06-28 11:35 ` Wilco Dijkstra
2021-06-28 11:39 ` Florian Weimer
2021-06-28 11:49 ` Szabolcs Nagy
2021-06-28 11:55 ` Adhemerval Zanella
2021-06-28 12:10 ` Wilco Dijkstra
2021-06-28 13:15 ` Adhemerval Zanella
2021-06-28 14:24 ` Wilco Dijkstra
2021-06-28 14:46 ` Adhemerval Zanella
2021-06-28 19:16 ` Wilco Dijkstra
2021-06-30 8:46 ` Szabolcs Nagy
2021-06-30 8:55 ` Florian Weimer
2021-06-30 9:33 ` Siddhesh Poyarekar
2021-07-01 10:21 ` Wilco Dijkstra
2021-07-01 13:48 ` Szabolcs Nagy
2021-07-01 15:33 ` Wilco Dijkstra
2021-07-06 11:33 ` Florian Weimer
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