From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: x86@kernel.org, John Stultz <john.stultz@linaro.org>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Andy Lutomirski <luto@kernel.org>,
Christophe Leroy <christophe.leroy@c-s.fr>,
Paolo Bonzini <pbonzini@redhat.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Juergen Gross <jgross@suse.com>,
Haiyang Zhang <haiyangz@microsoft.com>,
Sasha Levin <sashal@kernel.org>,
Ralf Baechle <ralf@linux-mips.org>,
Paul Burton <paulburton@kernel.org>,
James Hogan <jhogan@kernel.org>,
Russell King <linux@armlinux.org.uk>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Marc Zyngier <maz@kernel.org>
Subject: [patch 09/15] clocksource: Add common vdso clock mode storage
Date: Tue, 14 Jan 2020 19:52:46 +0100 [thread overview]
Message-ID: <20200114185947.500141436@linutronix.de> (raw)
In-Reply-To: 20200114185237.273005683@linutronix.de
All architectures which use the generic VDSO code have their own storage
for the VDSO clock mode. That's pointless and just requires duplicate code.
Provide generic storage for it. The new Kconfig symbol is intermediate and
will be removed once all architectures are converted over.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
include/linux/clocksource.h | 12 +++++++++++-
kernel/time/clocksource.c | 9 +++++++++
kernel/time/vsyscall.c | 7 +++++++
lib/vdso/Kconfig | 3 +++
lib/vdso/gettimeofday.c | 13 +++++++++++--
5 files changed, 41 insertions(+), 3 deletions(-)
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -23,10 +23,19 @@
struct clocksource;
struct module;
-#ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
+#if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \
+ defined(CONFIG_GENERIC_VDSO_CLOCK_MODE)
#include <asm/clocksource.h>
#endif
+enum vdso_clock_mode {
+ VDSO_CLOCKMODE_NONE,
+#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+ VDSO_ARCH_CLOCKMODES,
+#endif
+ VDSO_CLOCKMODE_MAX,
+};
+
/**
* struct clocksource - hardware abstraction for a free running counter
* Provides mostly state-free accessors to the underlying hardware.
@@ -97,6 +106,7 @@ struct clocksource {
const char *name;
struct list_head list;
int rating;
+ enum vdso_clock_mode vdso_clock_mode;
unsigned long flags;
int (*enable)(struct clocksource *cs);
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -921,6 +921,15 @@ int __clocksource_register_scale(struct
clocksource_arch_init(cs);
+#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+ if (cs->vdso_clock_mode < 0 ||
+ cs->vdso_clock_mode >= VDSO_CLOCKMODE_MAX) {
+ pr_warn("clocksource %s registered with invalid VDSO mode %d. Disabling VDSO support.\n",
+ cs->name, cs->vdso_clock_mode);
+ cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
+ }
+#endif
+
/* Initialize mult/shift and max_idle_ns */
__clocksource_update_freq_scale(cs, scale, freq);
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -72,12 +72,19 @@ void update_vsyscall(struct timekeeper *
struct vdso_data *vdata = __arch_get_k_vdso_data();
struct vdso_timestamp *vdso_ts;
u64 nsec;
+ s32 mode;
/* copy vsyscall data */
vdso_write_begin(vdata);
+#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+ mode = tk->tkr_mono.clock->vdso_clock_mode;
+ vdata[CS_HRES_COARSE].clock_mode = mode;
+ vdata[CS_RAW].clock_mode = mode;
+#else
vdata[CS_HRES_COARSE].clock_mode = __arch_get_clock_mode(tk);
vdata[CS_RAW].clock_mode = __arch_get_clock_mode(tk);
+#endif
/* CLOCK_REALTIME also required for time() */
vdso_ts = &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
--- a/lib/vdso/Kconfig
+++ b/lib/vdso/Kconfig
@@ -30,4 +30,7 @@ config GENERIC_VDSO_TIME_NS
Selected by architectures which support time namespaces in the
VDSO
+config GENERIC_VDSO_CLOCK_MODE
+ bool
+
endif
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -7,6 +7,7 @@
#include <linux/time.h>
#include <linux/kernel.h>
#include <linux/hrtimer_defs.h>
+#include <linux/clocksource.h>
#include <vdso/datapage.h>
#include <vdso/helpers.h>
@@ -64,10 +65,14 @@ static int do_hres_timens(const struct v
do {
seq = vdso_read_begin(vd);
+ if (IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
+ vd->clock_mode == VDSO_CLOCKMODE_NONE)
+ return -1;
cycles = __arch_get_hw_counter(vd->clock_mode);
ns = vdso_ts->nsec;
last = vd->cycle_last;
- if (unlikely((s64)cycles < 0))
+ if (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
+ unlikely((s64)cycles < 0))
return -1;
ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
@@ -132,10 +137,14 @@ static __always_inline int do_hres(const
}
smp_rmb();
+ if (IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
+ vd->clock_mode == VDSO_CLOCKMODE_NONE)
+ return -1;
cycles = __arch_get_hw_counter(vd->clock_mode);
ns = vdso_ts->nsec;
last = vd->cycle_last;
- if (unlikely((s64)cycles < 0))
+ if (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
+ unlikely((s64)cycles < 0))
return -1;
ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
next prev parent reply other threads:[~2020-01-14 19:49 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-14 18:52 [patch 00/15] lib/vdso: Bugfix and consolidation Thomas Gleixner
2020-01-14 18:52 ` [patch 01/15] lib/vdso: Make __arch_update_vdso_data() logic understandable Thomas Gleixner
2020-01-17 15:07 ` [tip: timers/urgent] " tip-bot2 for Thomas Gleixner
2020-01-14 18:52 ` [patch 02/15] lib/vdso: Update coarse timekeeper unconditionally Thomas Gleixner
2020-01-17 15:07 ` [tip: timers/urgent] " tip-bot2 for Thomas Gleixner
2020-01-14 18:52 ` [patch 03/15] ARM: vdso: Remove unused function Thomas Gleixner
2020-01-14 18:52 ` [patch 04/15] lib/vdso: Allow the high resolution parts to be compiled out Thomas Gleixner
2020-01-14 18:52 ` [patch 05/15] ARM: vdso: Compile high resolution parts conditionally Thomas Gleixner
2020-01-14 18:52 ` [patch 06/15] MIPS: " Thomas Gleixner
2020-01-14 18:52 ` [patch 07/15] clocksource: Cleanup struct clocksource and documentation Thomas Gleixner
2020-01-14 18:52 ` [patch 08/15] x86/vdso: Move VDSO clocksource state tracking to callback Thomas Gleixner
2020-01-15 5:56 ` Jürgen Groß
2020-01-20 1:42 ` Michael Kelley
2020-01-14 18:52 ` Thomas Gleixner [this message]
2020-01-15 5:50 ` [patch 09/15] clocksource: Add common vdso clock mode storage Christophe Leroy
2020-01-15 7:59 ` Thomas Gleixner
2020-01-14 18:52 ` [patch 10/15] x86/vdso: Use generic VDSO " Thomas Gleixner
2020-01-15 5:57 ` Jürgen Groß
2020-01-14 18:52 ` [patch 11/15] mips: vdso: " Thomas Gleixner
2020-01-14 18:52 ` [patch 12/15] ARM/arm64: vdso: Use common vdso " Thomas Gleixner
2020-01-14 18:52 ` [patch 13/15] lib/vdso: Cleanup clock mode storage leftovers Thomas Gleixner
2020-01-14 18:52 ` [patch 14/15] lib/vdso: Avoid highres update if clocksource is not VDSO capable Thomas Gleixner
2020-01-15 5:54 ` Christophe Leroy
2020-01-14 18:52 ` [patch 15/15] lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes Thomas Gleixner
2020-01-15 5:58 ` Christophe Leroy
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