From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Andy Lutomirski <luto@kernel.org>,
x86@kernel.org, Peter Zijlstra <peterz@infradead.org>,
Matt Rickard <matt@softrans.com.au>,
Stephen Boyd <sboyd@kernel.org>,
John Stultz <john.stultz@linaro.org>,
Florian Weimer <fweimer@redhat.com>,
"K. Y. Srinivasan" <kys@microsoft.com>,
Vitaly Kuznetsov <vkuznets@redhat.com>,
devel@linuxdriverproject.org,
virtualization@lists.linux-foundation.org,
Paolo Bonzini <pbonzini@redhat.com>,
Arnd Bergmann <arnd@arndb.de>, Juergen Gross <jgross@suse.com>
Subject: [patch 11/11] x66/vdso: Add CLOCK_TAI support
Date: Fri, 14 Sep 2018 14:50:17 +0200 [thread overview]
Message-ID: <20180914125119.081037164@linutronix.de> (raw)
In-Reply-To: 20180914125006.349747096@linutronix.de
[-- Attachment #1: x66-vdso--Add-CLOCK_TAI-support.patch --]
[-- Type: text/plain, Size: 2325 bytes --]
With the storage array in place it's now trivial to support CLOCK_TAI in
the vdso. Instead of extending the array to accomodate CLOCK_TAI, make use
of the fact that:
- CLOCK ids are set in stone
- CLOCK_THREAD_CPUTIME is never going to be supported in the VDSO so
the array slot 3 is unused
- CLOCK_TAI is id 11 which results in 3 when masked with 0x3
Add the mask to the basetime array lookup and set up the CLOCK_TAI base
time in update_vsyscall().
The performance impact of the mask operation is within the noise.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
arch/x86/entry/vdso/vclock_gettime.c | 2 +-
arch/x86/entry/vsyscall/vsyscall_gtod.c | 4 ++++
arch/x86/include/asm/vgtod.h | 6 +++++-
3 files changed, 10 insertions(+), 2 deletions(-)
--- a/arch/x86/entry/vdso/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vclock_gettime.c
@@ -140,7 +140,7 @@ notrace static inline u64 vgetcyc(int mo
notrace static int do_hres(clockid_t clk, struct timespec *ts)
{
- struct vgtod_ts *base = >od->basetime[clk];
+ struct vgtod_ts *base = >od->basetime[clk & VGTOD_HRES_MASK];
u64 cycles, last, ns;
unsigned int seq;
--- a/arch/x86/entry/vsyscall/vsyscall_gtod.c
+++ b/arch/x86/entry/vsyscall/vsyscall_gtod.c
@@ -51,6 +51,10 @@ void update_vsyscall(struct timekeeper *
base->sec = tk->xtime_sec;
base->nsec = tk->tkr_mono.xtime_nsec;
+ base = &vdata->basetime[VGTOD_TAI];
+ base->sec = tk->xtime_sec + (s64)tk->tai_offset;
+ base->nsec = tk->tkr_mono.xtime_nsec;
+
base = &vdata->basetime[CLOCK_MONOTONIC];
base->sec = tk->xtime_sec + tk->wall_to_monotonic.tv_sec;
nsec = tk->tkr_mono.xtime_nsec;
--- a/arch/x86/include/asm/vgtod.h
+++ b/arch/x86/include/asm/vgtod.h
@@ -19,9 +19,13 @@ struct vgtod_ts {
};
#define VGTOD_BASES (CLOCK_MONOTONIC_COARSE + 1)
-#define VGTOD_HRES (BIT(CLOCK_REALTIME) | BIT(CLOCK_MONOTONIC))
+#define VGTOD_HRES (BIT(CLOCK_REALTIME) | BIT(CLOCK_MONOTONIC) | BIT(CLOCK_TAI))
#define VGTOD_COARSE (BIT(CLOCK_REALTIME_COARSE) | BIT(CLOCK_MONOTONIC_COARSE))
+/* Abuse CLOCK_THREAD_CPUTIME_ID for VGTOD CLOCK TAI */
+#define VGTOD_HRES_MASK 0x3
+#define VGTOD_TAI (CLOCK_TAI & VGTOD_HRES_MASK)
+
/*
* vsyscall_gtod_data will be accessed by 32 and 64 bit code at the same time
* so be carefull by modifying this structure.
next prev parent reply other threads:[~2018-09-14 12:52 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-14 12:50 [patch 00/11] x86/vdso: Cleanups, simmplifications and CLOCK_TAI support Thomas Gleixner
2018-09-14 12:50 ` [patch 01/11] clocksource: Provide clocksource_arch_init() Thomas Gleixner
2018-09-14 12:50 ` [patch 02/11] x86/time: Implement clocksource_arch_init() Thomas Gleixner
2018-09-14 15:45 ` Vitaly Kuznetsov
2018-09-15 6:05 ` Thomas Gleixner
2018-09-14 12:50 ` [patch 03/11] x86/vdso: Enforce 64bit clocksource Thomas Gleixner
2018-09-14 12:50 ` [patch 04/11] x86/vdso: Use unsigned int consistently for vsyscall_gtod_data::seq Thomas Gleixner
2018-09-14 12:50 ` [patch 05/11] x86/vdso: Introduce and use vgtod_ts Thomas Gleixner
2018-09-14 12:50 ` [patch 06/11] x86/vdso: Collapse high resolution functions Thomas Gleixner
2018-09-14 12:50 ` [patch 07/11] x86/vdso: Collapse coarse functions Thomas Gleixner
2018-09-14 12:50 ` [patch 08/11] x86/vdso: Replace the clockid switch case Thomas Gleixner
2018-09-14 12:50 ` [patch 09/11] x86/vdso: Simplify the invalid vclock case Thomas Gleixner
2018-09-17 19:25 ` Andy Lutomirski
2018-09-17 20:12 ` John Stultz
2018-09-18 7:52 ` Thomas Gleixner
2018-09-18 8:30 ` Peter Zijlstra
2018-09-18 8:52 ` Thomas Gleixner
2018-09-18 10:06 ` Thomas Gleixner
2018-09-18 10:41 ` Thomas Gleixner
2018-09-18 12:48 ` Peter Zijlstra
2018-09-18 13:23 ` Thomas Gleixner
2018-09-18 13:38 ` Peter Zijlstra
2018-09-18 15:52 ` Thomas Gleixner
2018-09-27 14:41 ` Thomas Gleixner
2018-09-18 14:01 ` Andy Lutomirski
2018-09-18 22:46 ` Thomas Gleixner
2018-09-18 23:03 ` Andy Lutomirski
2018-09-18 23:16 ` Thomas Gleixner
2018-09-27 14:36 ` Thomas Gleixner
2018-09-27 14:39 ` Andy Lutomirski
2018-09-19 9:08 ` Rasmus Villemoes
2018-09-19 13:29 ` Thomas Gleixner
2018-09-14 12:50 ` [patch 10/11] x86/vdso: Move cycle_last handling into the caller Thomas Gleixner
2018-09-14 15:26 ` Vitaly Kuznetsov
2018-09-14 12:50 ` Thomas Gleixner [this message]
2018-09-14 14:04 ` [patch 11/11] x66/vdso: Add CLOCK_TAI support Andy Lutomirski
2018-09-14 14:27 ` Thomas Gleixner
2018-09-14 14:59 ` Andy Lutomirski
2018-09-16 9:39 ` Thomas Gleixner
2018-09-14 12:56 ` [patch 00/11] x86/vdso: Cleanups, simmplifications and " Florian Weimer
2018-09-14 13:05 ` Thomas Gleixner
2018-09-14 13:06 ` Florian Weimer
2018-09-14 13:19 ` Thomas Gleixner
2018-09-14 13:09 ` Peter Zijlstra
2018-09-14 14:22 ` Arnd Bergmann
2018-09-17 13:00 ` Thomas Gleixner
2018-09-24 21:08 ` Arnd Bergmann
2018-10-03 5:15 ` Andy Lutomirski
2018-10-03 9:22 ` Vitaly Kuznetsov
2018-10-03 10:20 ` Andy Lutomirski
2018-10-03 12:01 ` Vitaly Kuznetsov
2018-10-03 14:20 ` Andy Lutomirski
2018-10-03 15:10 ` Thomas Gleixner
2018-10-03 16:18 ` Andy Lutomirski
2018-10-03 19:06 ` Marcelo Tosatti
2018-10-04 7:54 ` Vitaly Kuznetsov
2018-10-04 8:11 ` Peter Zijlstra
2018-10-04 14:00 ` Andy Lutomirski
2018-10-04 19:31 ` Peter Zijlstra
2018-10-04 20:05 ` Andy Lutomirski
2018-10-04 22:15 ` Andy Lutomirski
2018-10-06 20:27 ` Marcelo Tosatti
2018-10-06 22:28 ` Andy Lutomirski
2018-10-08 15:26 ` Marcelo Tosatti
2018-10-08 17:38 ` Andy Lutomirski
2018-10-08 19:36 ` Marcelo Tosatti
2018-10-09 20:09 ` Andy Lutomirski
2018-10-11 22:27 ` Marcelo Tosatti
2018-10-11 23:00 ` Andy Lutomirski
2018-10-15 13:39 ` Marcelo Tosatti
2018-10-06 20:49 ` Marcelo Tosatti
2018-10-04 12:00 ` Paolo Bonzini
2018-10-04 14:04 ` Andy Lutomirski
2018-10-05 21:18 ` Marcelo Tosatti
2018-10-03 19:00 ` Marcelo Tosatti
2018-10-03 19:05 ` [patch 00/11] x86/vdso: Cleanups, simmplifications and CLOCK_TAI support\ Marcelo Tosatti
2018-10-03 22:32 ` [patch 00/11] x86/vdso: Cleanups, simmplifications and CLOCK_TAI support Andy Lutomirski
2018-10-04 16:37 ` Marcelo Tosatti
2018-10-04 17:08 ` Andy Lutomirski
2018-10-04 17:28 ` Vitaly Kuznetsov
2018-10-04 20:32 ` Andy Lutomirski
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