linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: "tip-bot2 for Thomas Gleixner" <tip-bot2@linutronix.de>
To: linux-tip-commits@vger.kernel.org
Cc: Thomas Gleixner <tglx@linutronix.de>,
	Michael Kelley <mikelley@microsoft.com>,
	Vincenzo Frascino <vincenzo.frascino@arm.com>,
	Juergen Gross <jgross@suse.com>, x86 <x86@kernel.org>,
	LKML <linux-kernel@vger.kernel.org>
Subject: [tip: timers/core] x86/vdso: Move VDSO clocksource state tracking to callback
Date: Mon, 17 Feb 2020 15:11:57 -0000	[thread overview]
Message-ID: <158195231716.13786.205682396062194204.tip-bot2@tip-bot2> (raw)
In-Reply-To: <20200207124402.934519777@linutronix.de>

The following commit has been merged into the timers/core branch of tip:

Commit-ID:     eec399dd862762b9594df3659f15839a4e12f17a
Gitweb:        https://git.kernel.org/tip/eec399dd862762b9594df3659f15839a4e12f17a
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:54 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:22 +01:00

x86/vdso: Move VDSO clocksource state tracking to callback

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.

X86 abuses the function which retrieves the architecture specific clock
mode storage to mark the clocksource as used in the VDSO. That's silly
because this is invoked on every tick when the VDSO data is updated.

Move this functionality to the clocksource::enable() callback so it gets
invoked once when the clocksource is installed. This allows to make the
clock mode storage generic.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>  (Hyper-V parts)
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> (VDSO parts)
Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)
Link: https://lkml.kernel.org/r/20200207124402.934519777@linutronix.de


---
 arch/x86/entry/vdso/vma.c            |  4 +++-
 arch/x86/include/asm/clocksource.h   | 12 ++++++++++-
 arch/x86/include/asm/mshyperv.h      |  2 ++-
 arch/x86/include/asm/vdso/vsyscall.h | 10 +--------
 arch/x86/include/asm/vgtod.h         |  6 +-----
 arch/x86/kernel/kvmclock.c           |  7 ++++++-
 arch/x86/kernel/tsc.c                | 32 ++++++++++++++++-----------
 arch/x86/xen/time.c                  | 17 +++++++++-----
 drivers/clocksource/hyperv_timer.c   |  7 ++++++-
 9 files changed, 65 insertions(+), 32 deletions(-)

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index c1b8496..cce3e80 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -38,6 +38,8 @@ struct vdso_data *arch_get_vdso_data(void *vvar_page)
 }
 #undef EMIT_VVAR
 
+unsigned int vclocks_used __read_mostly;
+
 #if defined(CONFIG_X86_64)
 unsigned int __read_mostly vdso64_enabled = 1;
 #endif
@@ -445,6 +447,8 @@ __setup("vdso=", vdso_setup);
 
 static int __init init_vdso(void)
 {
+	BUILD_BUG_ON(VCLOCK_MAX >= 32);
+
 	init_vdso_image(&vdso_image_64);
 
 #ifdef CONFIG_X86_X32_ABI
diff --git a/arch/x86/include/asm/clocksource.h b/arch/x86/include/asm/clocksource.h
index dc4cfc8..2450d6e 100644
--- a/arch/x86/include/asm/clocksource.h
+++ b/arch/x86/include/asm/clocksource.h
@@ -14,4 +14,16 @@ struct arch_clocksource_data {
 	int vclock_mode;
 };
 
+extern unsigned int vclocks_used;
+
+static inline bool vclock_was_used(int vclock)
+{
+	return READ_ONCE(vclocks_used) & (1U << vclock);
+}
+
+static inline void vclocks_set_used(unsigned int which)
+{
+	WRITE_ONCE(vclocks_used, READ_ONCE(vclocks_used) | (1 << which));
+}
+
 #endif /* _ASM_X86_CLOCKSOURCE_H */
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 6b79515..f7cbc01 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -47,6 +47,8 @@ typedef int (*hyperv_fill_flush_list_func)(
 	wrmsrl(HV_X64_MSR_REFERENCE_TSC, val)
 #define hv_set_clocksource_vdso(val) \
 	((val).archdata.vclock_mode = VCLOCK_HVCLOCK)
+#define hv_enable_vdso_clocksource() \
+	vclocks_set_used(VCLOCK_HVCLOCK);
 #define hv_get_raw_timer() rdtsc_ordered()
 
 void hyperv_callback_vector(void);
diff --git a/arch/x86/include/asm/vdso/vsyscall.h b/arch/x86/include/asm/vdso/vsyscall.h
index 0026ab2..01f5733 100644
--- a/arch/x86/include/asm/vdso/vsyscall.h
+++ b/arch/x86/include/asm/vdso/vsyscall.h
@@ -10,8 +10,6 @@
 #include <asm/vgtod.h>
 #include <asm/vvar.h>
 
-int vclocks_used __read_mostly;
-
 DEFINE_VVAR(struct vdso_data, _vdso_data);
 /*
  * Update the vDSO data page to keep in sync with kernel timekeeping.
@@ -26,13 +24,7 @@ struct vdso_data *__x86_get_k_vdso_data(void)
 static __always_inline
 int __x86_get_clock_mode(struct timekeeper *tk)
 {
-	int vclock_mode = tk->tkr_mono.clock->archdata.vclock_mode;
-
-	/* Mark the new vclock used. */
-	BUILD_BUG_ON(VCLOCK_MAX >= 32);
-	WRITE_ONCE(vclocks_used, READ_ONCE(vclocks_used) | (1 << vclock_mode));
-
-	return vclock_mode;
+	return tk->tkr_mono.clock->archdata.vclock_mode;
 }
 #define __arch_get_clock_mode __x86_get_clock_mode
 
diff --git a/arch/x86/include/asm/vgtod.h b/arch/x86/include/asm/vgtod.h
index a2638c6..fc8e4cd 100644
--- a/arch/x86/include/asm/vgtod.h
+++ b/arch/x86/include/asm/vgtod.h
@@ -15,10 +15,4 @@ typedef u64 gtod_long_t;
 typedef unsigned long gtod_long_t;
 #endif
 
-extern int vclocks_used;
-static inline bool vclock_was_used(int vclock)
-{
-	return READ_ONCE(vclocks_used) & (1 << vclock);
-}
-
 #endif /* _ASM_X86_VGTOD_H */
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 904494b..33f2cac 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -159,12 +159,19 @@ bool kvm_check_and_clear_guest_paused(void)
 	return ret;
 }
 
+static int kvm_cs_enable(struct clocksource *cs)
+{
+	vclocks_set_used(VCLOCK_PVCLOCK);
+	return 0;
+}
+
 struct clocksource kvm_clock = {
 	.name	= "kvm-clock",
 	.read	= kvm_clock_get_cycles,
 	.rating	= 400,
 	.mask	= CLOCKSOURCE_MASK(64),
 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
+	.enable	= kvm_cs_enable,
 };
 EXPORT_SYMBOL_GPL(kvm_clock);
 
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 7e322e2..742da14 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1108,17 +1108,24 @@ static void tsc_cs_tick_stable(struct clocksource *cs)
 		sched_clock_tick_stable();
 }
 
+static int tsc_cs_enable(struct clocksource *cs)
+{
+	vclocks_set_used(VCLOCK_TSC);
+	return 0;
+}
+
 /*
  * .mask MUST be CLOCKSOURCE_MASK(64). See comment above read_tsc()
  */
 static struct clocksource clocksource_tsc_early = {
-	.name                   = "tsc-early",
-	.rating                 = 299,
-	.read                   = read_tsc,
-	.mask                   = CLOCKSOURCE_MASK(64),
-	.flags                  = CLOCK_SOURCE_IS_CONTINUOUS |
+	.name			= "tsc-early",
+	.rating			= 299,
+	.read			= read_tsc,
+	.mask			= CLOCKSOURCE_MASK(64),
+	.flags			= CLOCK_SOURCE_IS_CONTINUOUS |
 				  CLOCK_SOURCE_MUST_VERIFY,
-	.archdata               = { .vclock_mode = VCLOCK_TSC },
+	.archdata		= { .vclock_mode = VCLOCK_TSC },
+	.enable			= tsc_cs_enable,
 	.resume			= tsc_resume,
 	.mark_unstable		= tsc_cs_mark_unstable,
 	.tick_stable		= tsc_cs_tick_stable,
@@ -1131,14 +1138,15 @@ static struct clocksource clocksource_tsc_early = {
  * been found good.
  */
 static struct clocksource clocksource_tsc = {
-	.name                   = "tsc",
-	.rating                 = 300,
-	.read                   = read_tsc,
-	.mask                   = CLOCKSOURCE_MASK(64),
-	.flags                  = CLOCK_SOURCE_IS_CONTINUOUS |
+	.name			= "tsc",
+	.rating			= 300,
+	.read			= read_tsc,
+	.mask			= CLOCKSOURCE_MASK(64),
+	.flags			= CLOCK_SOURCE_IS_CONTINUOUS |
 				  CLOCK_SOURCE_VALID_FOR_HRES |
 				  CLOCK_SOURCE_MUST_VERIFY,
-	.archdata               = { .vclock_mode = VCLOCK_TSC },
+	.archdata		= { .vclock_mode = VCLOCK_TSC },
+	.enable			= tsc_cs_enable,
 	.resume			= tsc_resume,
 	.mark_unstable		= tsc_cs_mark_unstable,
 	.tick_stable		= tsc_cs_tick_stable,
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index befbdd8..5d1568f 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -145,12 +145,19 @@ static struct notifier_block xen_pvclock_gtod_notifier = {
 	.notifier_call = xen_pvclock_gtod_notify,
 };
 
+static int xen_cs_enable(struct clocksource *cs)
+{
+	vclocks_set_used(VCLOCK_PVCLOCK);
+	return 0;
+}
+
 static struct clocksource xen_clocksource __read_mostly = {
-	.name = "xen",
-	.rating = 400,
-	.read = xen_clocksource_get_cycles,
-	.mask = ~0,
-	.flags = CLOCK_SOURCE_IS_CONTINUOUS,
+	.name	= "xen",
+	.rating	= 400,
+	.read	= xen_clocksource_get_cycles,
+	.mask	= CLOCKSOURCE_MASK(64),
+	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
+	.enable = xen_cs_enable,
 };
 
 /*
diff --git a/drivers/clocksource/hyperv_timer.c b/drivers/clocksource/hyperv_timer.c
index 9d808d5..a86859c 100644
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -369,6 +369,12 @@ static void resume_hv_clock_tsc(struct clocksource *arg)
 	hv_set_reference_tsc(tsc_msr);
 }
 
+static int hv_cs_enable(struct clocksource *cs)
+{
+	hv_enable_vdso_clocksource();
+	return 0;
+}
+
 static struct clocksource hyperv_cs_tsc = {
 	.name	= "hyperv_clocksource_tsc_page",
 	.rating	= 250,
@@ -377,6 +383,7 @@ static struct clocksource hyperv_cs_tsc = {
 	.flags	= CLOCK_SOURCE_IS_CONTINUOUS,
 	.suspend= suspend_hv_clock_tsc,
 	.resume	= resume_hv_clock_tsc,
+	.enable = hv_cs_enable,
 };
 
 static u64 notrace read_hv_clock_msr(void)

  parent reply	other threads:[~2020-02-17 15:12 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-07 12:38 [patch V2 00/17] VDSO consolidation Thomas Gleixner
2020-02-07 12:38 ` [patch V2 01/17] x86/vdso: Mark the TSC clocksource path likely Thomas Gleixner
2020-02-14 12:00   ` Vincenzo Frascino
2020-02-17 15:12   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 02/17] ARM: vdso: Remove unused function Thomas Gleixner
2020-02-14 10:21   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 03/17] lib/vdso: Allow the high resolution parts to be compiled out Thomas Gleixner
2020-02-14 11:54   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 04/17] ARM: vdso: Compile high resolution parts conditionally Thomas Gleixner
2020-02-14 11:55   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 05/17] MIPS: " Thomas Gleixner
2020-02-14 11:55   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 06/17] clocksource: Cleanup struct clocksource and documentation Thomas Gleixner
2020-02-14 11:57   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 07/17] x86/vdso: Move VDSO clocksource state tracking to callback Thomas Gleixner
2020-02-14 11:58   ` Vincenzo Frascino
2020-02-17 15:11   ` tip-bot2 for Thomas Gleixner [this message]
2020-02-07 12:38 ` [patch V2 08/17] clocksource: Add common vdso clock mode storage Thomas Gleixner
2020-02-17 10:36   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 09/17] x86/vdso: Use generic VDSO " Thomas Gleixner
2020-02-14 10:32   ` Paolo Bonzini
2020-02-17 10:57   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 10/17] mips: vdso: " Thomas Gleixner
2020-02-17 10:52   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
2020-02-07 12:38 ` [patch V2 11/17] ARM/arm64: vdso: Use common vdso " Thomas Gleixner
2020-02-17 10:43   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
     [not found]   ` <CGME20200221115643eucas1p12ecb95c6161853a0e7dfe9207db079be@eucas1p1.samsung.com>
2020-02-21 11:56     ` [patch V2 11/17] " Marek Szyprowski
2020-02-21 13:08       ` Vincenzo Frascino
2020-02-21 18:24       ` Vincenzo Frascino
2020-02-07 12:38 ` [patch V2 12/17] lib/vdso: Cleanup clock mode storage leftovers Thomas Gleixner
2020-02-17 11:04   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
2020-02-07 12:39 ` [patch V2 13/17] lib/vdso: Avoid highres update if clocksource is not VDSO capable Thomas Gleixner
2020-02-17 11:07   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
2020-02-07 12:39 ` [patch V2 14/17] lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes Thomas Gleixner
2020-02-17 11:12   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Thomas Gleixner
2020-02-17 19:18   ` tip-bot2 for Thomas Gleixner
2020-02-07 12:39 ` [patch V2 15/17] lib/vdso: Allow fixed clock mode Thomas Gleixner
2020-02-17 11:14   ` Vincenzo Frascino
2020-02-17 15:11   ` [tip: timers/core] " tip-bot2 for Christophe Leroy
2020-02-17 19:18   ` tip-bot2 for Christophe Leroy
2020-02-07 12:39 ` [patch V2 16/17] lib/vdso: Allow architectures to override the ns shift operation Thomas Gleixner
2020-02-17 11:15   ` Vincenzo Frascino
2020-02-07 12:39 ` [patch V2 17/17] lib/vdso: Allow architectures to provide the vdso data pointer Thomas Gleixner
2020-02-17 12:09   ` Vincenzo Frascino

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=158195231716.13786.205682396062194204.tip-bot2@tip-bot2 \
    --to=tip-bot2@linutronix.de \
    --cc=jgross@suse.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-tip-commits@vger.kernel.org \
    --cc=mikelley@microsoft.com \
    --cc=tglx@linutronix.de \
    --cc=vincenzo.frascino@arm.com \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).