[patch V2 00/17] VDSO consolidation

[patch V2 00/17] VDSO consolidation

[Thomas Gleixner]

This is the second version of the VDSO consolidation series. The first
version can be found here:

   https://lore.kernel.org/lkml/r/20200114185237.273005683@linutronix.de

The changes since V1:

    - Tiny optimization of x86/TSC (new)

    - Address review comments from V1 (bisectability, spelling ...)

    - Include the preparatory patches from Christophe which allow powerpc
      to be switched over.

This conflicts slightly with the ARM64 time namespace patch series, but
that's trivial to fix up.

Thanks,

	tglx

----
 arch/arm/Kconfig                            |    1 
 arch/arm/include/asm/clocksource.h          |    5 -
 arch/arm/include/asm/vdso/gettimeofday.h    |    6 +
 arch/arm/include/asm/vdso/vsyscall.h        |   35 -------
 arch/arm64/Kconfig                          |    1 
 arch/arm64/include/asm/clocksource.h        |    5 -
 arch/arm64/include/asm/vdso/vsyscall.h      |    9 -
 arch/mips/Kconfig                           |    1 
 arch/mips/include/asm/clocksource.h         |   18 ---
 arch/mips/include/asm/vdso/vsyscall.h       |    9 -
 arch/mips/kernel/csrc-r4k.c                 |    2 
 arch/x86/Kconfig                            |    1 
 arch/x86/entry/vdso/vma.c                   |    8 +
 arch/x86/include/asm/clocksource.h          |   23 +++-
 arch/x86/include/asm/mshyperv.h             |    4 
 arch/x86/include/asm/vdso/gettimeofday.h    |    6 -
 arch/x86/include/asm/vdso/vsyscall.h        |   15 ---
 arch/x86/include/asm/vgtod.h                |    6 -
 arch/x86/kernel/kvmclock.c                  |    9 +
 arch/x86/kernel/pvclock.c                   |    2 
 arch/x86/kernel/time.c                      |   12 --
 arch/x86/kernel/tsc.c                       |   32 ++++--
 arch/x86/kvm/trace.h                        |    4 
 arch/x86/kvm/x86.c                          |   22 ++--
 arch/x86/xen/time.c                         |   36 ++++---
 b/arch/mips/include/asm/vdso/gettimeofday.h |   29 ++----
 drivers/clocksource/arm_arch_timer.c        |    8 -
 drivers/clocksource/hyperv_timer.c          |    7 +
 drivers/clocksource/mips-gic-timer.c        |    8 -
 include/asm-generic/vdso/vsyscall.h         |   14 --
 include/linux/clocksource.h                 |  102 ++++++++++++---------
 include/vdso/datapage.h                     |    2 
 kernel/time/clocksource.c                   |    9 +
 kernel/time/namespace.c                     |    7 -
 kernel/time/vsyscall.c                      |   12 +-
 lib/vdso/gettimeofday.c                     |  133 +++++++++++++++++++++-------
 36 files changed, 317 insertions(+), 286 deletions(-)

[patch V2 01/17] x86/vdso: Mark the TSC clocksource path likely

[Thomas Gleixner]

Jumping out of line for the TSC clcoksource read is creating awful
code. TSC is likely to be the clocksource at least on bare metal and the PV
interfaces are sufficiently more work that the jump over the TSC read is
just in the noise.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/x86/include/asm/vdso/gettimeofday.h |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -243,7 +243,7 @@ static u64 vread_hvclock(void)
 
 static inline u64 __arch_get_hw_counter(s32 clock_mode)
 {
-	if (clock_mode == VCLOCK_TSC)
+	if (likely(clock_mode == VCLOCK_TSC))
 		return (u64)rdtsc_ordered();
 	/*
 	 * For any memory-mapped vclock type, we need to make sure that gcc

Re: [patch V2 01/17] x86/vdso: Mark the TSC clocksource path likely

[Vincenzo Frascino]

On 2/7/20 12:38 PM, Thomas Gleixner wrote:
> Jumping out of line for the TSC clcoksource read is creating awful
> code. TSC is likely to be the clocksource at least on bare metal and the PV
> interfaces are sufficiently more work that the jump over the TSC read is
> just in the noise.
>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> ---
>  arch/x86/include/asm/vdso/gettimeofday.h |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- a/arch/x86/include/asm/vdso/gettimeofday.h
> +++ b/arch/x86/include/asm/vdso/gettimeofday.h
> @@ -243,7 +243,7 @@ static u64 vread_hvclock(void)
>  
>  static inline u64 __arch_get_hw_counter(s32 clock_mode)
>  {
> -	if (clock_mode == VCLOCK_TSC)
> +	if (likely(clock_mode == VCLOCK_TSC))
>  		return (u64)rdtsc_ordered();
>  	/*
>  	 * For any memory-mapped vclock type, we need to make sure that gcc
> 

-- 
Regards,
Vincenzo

[tip: timers/core] x86/vdso: Mark the TSC clocksource path likely

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     50e818715821b89c7abac90a97721f106e893d83
Gitweb:        https://git.kernel.org/tip/50e818715821b89c7abac90a97721f106e893d83
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:48 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:19 +01:00

x86/vdso: Mark the TSC clocksource path likely

Jumping out of line for the TSC clcoksource read is creating awful
code. TSC is likely to be the clocksource at least on bare metal and the PV
interfaces are sufficiently more work that the jump over the TSC read is
just in the noise.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.328922847@linutronix.de

---
 arch/x86/include/asm/vdso/gettimeofday.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
index 6ee1f7d..264d4fd 100644
--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -243,7 +243,7 @@ static u64 vread_hvclock(void)
 
 static inline u64 __arch_get_hw_counter(s32 clock_mode)
 {
-	if (clock_mode == VCLOCK_TSC)
+	if (likely(clock_mode == VCLOCK_TSC))
 		return (u64)rdtsc_ordered();
 	/*
 	 * For any memory-mapped vclock type, we need to make sure that gcc

[patch V2 02/17] ARM: vdso: Remove unused function

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

The function is nowhere used. Aside of that this check should only cover
the high resolution parts of the VDSO which require a VDSO capable
clocksource and not the complete functionality as the name suggests. Will
be replaced with something more useful.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/arm/include/asm/vdso/vsyscall.h |    7 -------
 1 file changed, 7 deletions(-)

--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -50,13 +50,6 @@ int __arm_get_clock_mode(struct timekeep
 #define __arch_get_clock_mode __arm_get_clock_mode
 
 static __always_inline
-int __arm_use_vsyscall(struct vdso_data *vdata)
-{
-	return vdata[CS_HRES_COARSE].clock_mode;
-}
-#define __arch_use_vsyscall __arm_use_vsyscall
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));

Re: [patch V2 02/17] ARM: vdso: Remove unused function

[Vincenzo Frascino]

On 2/7/20 12:38 PM, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> The function is nowhere used. Aside of that this check should only cover
> the high resolution parts of the VDSO which require a VDSO capable
> clocksource and not the complete functionality as the name suggests. Will
> be replaced with something more useful.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
>  arch/arm/include/asm/vdso/vsyscall.h |    7 -------
>  1 file changed, 7 deletions(-)
> 
> --- a/arch/arm/include/asm/vdso/vsyscall.h
> +++ b/arch/arm/include/asm/vdso/vsyscall.h
> @@ -50,13 +50,6 @@ int __arm_get_clock_mode(struct timekeep
>  #define __arch_get_clock_mode __arm_get_clock_mode
>  
>  static __always_inline
> -int __arm_use_vsyscall(struct vdso_data *vdata)
> -{
> -	return vdata[CS_HRES_COARSE].clock_mode;
> -}
> -#define __arch_use_vsyscall __arm_use_vsyscall
> -
> -static __always_inline
>  void __arm_sync_vdso_data(struct vdso_data *vdata)
>  {
>  	flush_dcache_page(virt_to_page(vdata));
> 

-- 
Regards,
Vincenzo

[tip: timers/core] ARM: vdso: Remove unused function

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     78560d41064ad3d377e3d1a1ee87526301f4e946
Gitweb:        https://git.kernel.org/tip/78560d41064ad3d377e3d1a1ee87526301f4e946
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:49 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:20 +01:00

ARM: vdso: Remove unused function

The function is nowhere used. Aside of that this check should only cover
the high resolution parts of the VDSO which require a VDSO capable
clocksource and not the complete functionality as the name suggests. Will
be replaced with something more useful.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.438179009@linutronix.de


---
 arch/arm/include/asm/vdso/vsyscall.h | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/arch/arm/include/asm/vdso/vsyscall.h b/arch/arm/include/asm/vdso/vsyscall.h
index cff87d8..85a7e58 100644
--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -50,13 +50,6 @@ int __arm_get_clock_mode(struct timekeeper *tk)
 #define __arch_get_clock_mode __arm_get_clock_mode
 
 static __always_inline
-int __arm_use_vsyscall(struct vdso_data *vdata)
-{
-	return vdata[CS_HRES_COARSE].clock_mode;
-}
-#define __arch_use_vsyscall __arm_use_vsyscall
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));

[patch V2 03/17] lib/vdso: Allow the high resolution parts to be compiled out

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

If the architecture knows at compile time that there is no VDSO capable
clocksource supported it makes sense to optimize the guts of the high
resolution parts of the VDSO out at build time. Add a helper function to
check whether the VDSO should be high resolution capable and provide a stub
which can be overridden by an architecture.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 lib/vdso/gettimeofday.c |   11 +++++++++++
 1 file changed, 11 insertions(+)

--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -38,6 +38,13 @@ u64 vdso_calc_delta(u64 cycles, u64 last
 }
 #endif
 
+#ifndef __arch_vdso_hres_capable
+static inline bool __arch_vdso_hres_capable(void)
+{
+	return true;
+}
+#endif
+
 #ifdef CONFIG_TIME_NS
 static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 			  struct __kernel_timespec *ts)
@@ -101,6 +108,10 @@ static __always_inline int do_hres(const
 	u64 cycles, last, sec, ns;
 	u32 seq;
 
+	/* Allows to compile the high resolution parts out */
+	if (!__arch_vdso_hres_capable())
+		return -1;
+
 	do {
 		/*
 		 * Open coded to handle VCLOCK_TIMENS. Time namespace

Re: [patch V2 03/17] lib/vdso: Allow the high resolution parts to be compiled out

[Vincenzo Frascino]

On 2/7/20 12:38 PM, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> If the architecture knows at compile time that there is no VDSO capable
> clocksource supported it makes sense to optimize the guts of the high
> resolution parts of the VDSO out at build time. Add a helper function to
> check whether the VDSO should be high resolution capable and provide a stub
> which can be overridden by an architecture.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> 

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
>  lib/vdso/gettimeofday.c |   11 +++++++++++
>  1 file changed, 11 insertions(+)
> 
> --- a/lib/vdso/gettimeofday.c
> +++ b/lib/vdso/gettimeofday.c
> @@ -38,6 +38,13 @@ u64 vdso_calc_delta(u64 cycles, u64 last
>  }
>  #endif
>  
> +#ifndef __arch_vdso_hres_capable
> +static inline bool __arch_vdso_hres_capable(void)
> +{
> +	return true;
> +}
> +#endif
> +
>  #ifdef CONFIG_TIME_NS
>  static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
>  			  struct __kernel_timespec *ts)
> @@ -101,6 +108,10 @@ static __always_inline int do_hres(const
>  	u64 cycles, last, sec, ns;
>  	u32 seq;
>  
> +	/* Allows to compile the high resolution parts out */
> +	if (!__arch_vdso_hres_capable())
> +		return -1;
> +
>  	do {
>  		/*
>  		 * Open coded to handle VCLOCK_TIMENS. Time namespace
> 

-- 
Regards,
Vincenzo

[tip: timers/core] lib/vdso: Allow the high resolution parts to be compiled out

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     1dff4156d1f63b525c54aea7f097a657cbbbf837
Gitweb:        https://git.kernel.org/tip/1dff4156d1f63b525c54aea7f097a657cbbbf837
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:50 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:20 +01:00

lib/vdso: Allow the high resolution parts to be compiled out

If the architecture knows at compile time that there is no VDSO capable
clocksource supported it makes sense to optimize the guts of the high
resolution parts of the VDSO out at build time. Add a helper function to
check whether the VDSO should be high resolution capable and provide a stub
which can be overridden by an architecture.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.530143168@linutronix.de


---
 lib/vdso/gettimeofday.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index f8b8ec5..5804e4e 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -38,6 +38,13 @@ u64 vdso_calc_delta(u64 cycles, u64 last, u64 mask, u32 mult)
 }
 #endif
 
+#ifndef __arch_vdso_hres_capable
+static inline bool __arch_vdso_hres_capable(void)
+{
+	return true;
+}
+#endif
+
 #ifdef CONFIG_TIME_NS
 static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 			  struct __kernel_timespec *ts)
@@ -101,6 +108,10 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 	u64 cycles, last, sec, ns;
 	u32 seq;
 
+	/* Allows to compile the high resolution parts out */
+	if (!__arch_vdso_hres_capable())
+		return -1;
+
 	do {
 		/*
 		 * Open coded to handle VCLOCK_TIMENS. Time namespace

[patch V2 04/17] ARM: vdso: Compile high resolution parts conditionally

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

If the architected timer is disabled in the kernel configuration then let
the core VDSO code drop the high resolution parts at compile time.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/arm/include/asm/vdso/gettimeofday.h |    6 ++++++
 1 file changed, 6 insertions(+)

--- a/arch/arm/include/asm/vdso/gettimeofday.h
+++ b/arch/arm/include/asm/vdso/gettimeofday.h
@@ -106,6 +106,12 @@ static __always_inline int clock_getres3
 	return ret;
 }
 
+static inline bool arm_vdso_hres_capable(void)
+{
+	return IS_ENABLED(CONFIG_ARM_ARCH_TIMER);
+}
+#define __arch_vdso_hres_capable arm_vdso_hres_capable
+
 static __always_inline u64 __arch_get_hw_counter(int clock_mode)
 {
 #ifdef CONFIG_ARM_ARCH_TIMER

Re: [patch V2 04/17] ARM: vdso: Compile high resolution parts conditionally

[Vincenzo Frascino]

On 2/7/20 12:38 PM, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> If the architected timer is disabled in the kernel configuration then let
> the core VDSO code drop the high resolution parts at compile time.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
>  arch/arm/include/asm/vdso/gettimeofday.h |    6 ++++++
>  1 file changed, 6 insertions(+)
> 
> --- a/arch/arm/include/asm/vdso/gettimeofday.h
> +++ b/arch/arm/include/asm/vdso/gettimeofday.h
> @@ -106,6 +106,12 @@ static __always_inline int clock_getres3
>  	return ret;
>  }
>  
> +static inline bool arm_vdso_hres_capable(void)
> +{
> +	return IS_ENABLED(CONFIG_ARM_ARCH_TIMER);
> +}
> +#define __arch_vdso_hres_capable arm_vdso_hres_capable
> +
>  static __always_inline u64 __arch_get_hw_counter(int clock_mode)
>  {
>  #ifdef CONFIG_ARM_ARCH_TIMER
> 

-- 
Regards,
Vincenzo

[tip: timers/core] ARM: vdso: Compile high resolution parts conditionally

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     3280badbe1b289622ce12b94d064ddb624cbaef1
Gitweb:        https://git.kernel.org/tip/3280badbe1b289622ce12b94d064ddb624cbaef1
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:51 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:21 +01:00

ARM: vdso: Compile high resolution parts conditionally

If the architected timer is disabled in the kernel configuration then let
the core VDSO code drop the high resolution parts at compile time.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.622587341@linutronix.de


---
 arch/arm/include/asm/vdso/gettimeofday.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/arch/arm/include/asm/vdso/gettimeofday.h b/arch/arm/include/asm/vdso/gettimeofday.h
index fe6e1f6..f4757d3 100644
--- a/arch/arm/include/asm/vdso/gettimeofday.h
+++ b/arch/arm/include/asm/vdso/gettimeofday.h
@@ -106,6 +106,12 @@ static __always_inline int clock_getres32_fallback(
 	return ret;
 }
 
+static inline bool arm_vdso_hres_capable(void)
+{
+	return IS_ENABLED(CONFIG_ARM_ARCH_TIMER);
+}
+#define __arch_vdso_hres_capable arm_vdso_hres_capable
+
 static __always_inline u64 __arch_get_hw_counter(int clock_mode)
 {
 #ifdef CONFIG_ARM_ARCH_TIMER

[patch V2 05/17] MIPS: vdso: Compile high resolution parts conditionally

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

If neither the R4K nor the GIC timer is enabled in the kernel configuration
then let the core VDSO code drop the high resolution parts at compile time.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/mips/include/asm/vdso/gettimeofday.h |    7 +++++++
 1 file changed, 7 insertions(+)

--- a/arch/mips/include/asm/vdso/gettimeofday.h
+++ b/arch/mips/include/asm/vdso/gettimeofday.h
@@ -199,6 +199,13 @@ static __always_inline u64 __arch_get_hw
 	return cycle_now;
 }
 
+static inline bool mips_vdso_hres_capable(void)
+{
+	return IS_ENABLED(CONFIG_CSRC_R4K) ||
+	       IS_ENABLED(CONFIG_CLKSRC_MIPS_GIC);
+}
+#define __arch_vdso_hres_capable mips_vdso_hres_capable
+
 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
 {
 	return get_vdso_data();

Re: [patch V2 05/17] MIPS: vdso: Compile high resolution parts conditionally

[Vincenzo Frascino]

On 2/7/20 12:38 PM, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> If neither the R4K nor the GIC timer is enabled in the kernel configuration
> then let the core VDSO code drop the high resolution parts at compile time.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
>  arch/mips/include/asm/vdso/gettimeofday.h |    7 +++++++
>  1 file changed, 7 insertions(+)
> 
> --- a/arch/mips/include/asm/vdso/gettimeofday.h
> +++ b/arch/mips/include/asm/vdso/gettimeofday.h
> @@ -199,6 +199,13 @@ static __always_inline u64 __arch_get_hw
>  	return cycle_now;
>  }
>  
> +static inline bool mips_vdso_hres_capable(void)
> +{
> +	return IS_ENABLED(CONFIG_CSRC_R4K) ||
> +	       IS_ENABLED(CONFIG_CLKSRC_MIPS_GIC);
> +}
> +#define __arch_vdso_hres_capable mips_vdso_hres_capable
> +
>  static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
>  {
>  	return get_vdso_data();
> 

-- 
Regards,
Vincenzo

[tip: timers/core] MIPS: vdso: Compile high resolution parts conditionally

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     25a2a6567829119f5e3e11eb0ce3d8ae985b6019
Gitweb:        https://git.kernel.org/tip/25a2a6567829119f5e3e11eb0ce3d8ae985b6019
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:52 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:21 +01:00

MIPS: vdso: Compile high resolution parts conditionally

If neither the R4K nor the GIC timer is enabled in the kernel configuration
then let the core VDSO code drop the high resolution parts at compile time.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.714585315@linutronix.de


---
 arch/mips/include/asm/vdso/gettimeofday.h | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h
index a58687e..a9f846b 100644
--- a/arch/mips/include/asm/vdso/gettimeofday.h
+++ b/arch/mips/include/asm/vdso/gettimeofday.h
@@ -199,6 +199,13 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 	return cycle_now;
 }
 
+static inline bool mips_vdso_hres_capable(void)
+{
+	return IS_ENABLED(CONFIG_CSRC_R4K) ||
+	       IS_ENABLED(CONFIG_CLKSRC_MIPS_GIC);
+}
+#define __arch_vdso_hres_capable mips_vdso_hres_capable
+
 static __always_inline const struct vdso_data *__arch_get_vdso_data(void)
 {
 	return get_vdso_data();

[patch V2 06/17] clocksource: Cleanup struct clocksource and documentation

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

Reformat the struct definition, add missing member documentation.
No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 include/linux/clocksource.h |   87 +++++++++++++++++++++++---------------------
 1 file changed, 47 insertions(+), 40 deletions(-)

--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -32,9 +32,19 @@ struct module;
  *	Provides mostly state-free accessors to the underlying hardware.
  *	This is the structure used for system time.
  *
- * @name:		ptr to clocksource name
- * @list:		list head for registration
- * @rating:		rating value for selection (higher is better)
+ * @read:		Returns a cycle value, passes clocksource as argument
+ * @mask:		Bitmask for two's complement
+ *			subtraction of non 64 bit counters
+ * @mult:		Cycle to nanosecond multiplier
+ * @shift:		Cycle to nanosecond divisor (power of two)
+ * @max_idle_ns:	Maximum idle time permitted by the clocksource (nsecs)
+ * @maxadj:		Maximum adjustment value to mult (~11%)
+ * @archdata:		Optional arch-specific data
+ * @max_cycles:		Maximum safe cycle value which won't overflow on
+ *			multiplication
+ * @name:		Pointer to clocksource name
+ * @list:		List head for registration (internal)
+ * @rating:		Rating value for selection (higher is better)
  *			To avoid rating inflation the following
  *			list should give you a guide as to how
  *			to assign your clocksource a rating
@@ -49,27 +59,23 @@ struct module;
  *			400-499: Perfect
  *				The ideal clocksource. A must-use where
  *				available.
- * @read:		returns a cycle value, passes clocksource as argument
- * @enable:		optional function to enable the clocksource
- * @disable:		optional function to disable the clocksource
- * @mask:		bitmask for two's complement
- *			subtraction of non 64 bit counters
- * @mult:		cycle to nanosecond multiplier
- * @shift:		cycle to nanosecond divisor (power of two)
- * @max_idle_ns:	max idle time permitted by the clocksource (nsecs)
- * @maxadj:		maximum adjustment value to mult (~11%)
- * @max_cycles:		maximum safe cycle value which won't overflow on multiplication
- * @flags:		flags describing special properties
- * @archdata:		arch-specific data
- * @suspend:		suspend function for the clocksource, if necessary
- * @resume:		resume function for the clocksource, if necessary
+ * @flags:		Flags describing special properties
+ * @enable:		Optional function to enable the clocksource
+ * @disable:		Optional function to disable the clocksource
+ * @suspend:		Optional suspend function for the clocksource
+ * @resume:		Optional resume function for the clocksource
  * @mark_unstable:	Optional function to inform the clocksource driver that
  *			the watchdog marked the clocksource unstable
- * @owner:		module reference, must be set by clocksource in modules
+ * @tick_stable:        Optional function called periodically from the watchdog
+ *			code to provide stable syncrhonization points
+ * @wd_list:		List head to enqueue into the watchdog list (internal)
+ * @cs_last:		Last clocksource value for clocksource watchdog
+ * @wd_last:		Last watchdog value corresponding to @cs_last
+ * @owner:		Module reference, must be set by clocksource in modules
  *
  * Note: This struct is not used in hotpathes of the timekeeping code
  * because the timekeeper caches the hot path fields in its own data
- * structure, so no line cache alignment is required,
+ * structure, so no cache line alignment is required,
  *
  * The pointer to the clocksource itself is handed to the read
  * callback. If you need extra information there you can wrap struct
@@ -78,35 +84,36 @@ struct module;
  * structure.
  */
 struct clocksource {
-	u64 (*read)(struct clocksource *cs);
-	u64 mask;
-	u32 mult;
-	u32 shift;
-	u64 max_idle_ns;
-	u32 maxadj;
+	u64			(*read)(struct clocksource *cs);
+	u64			mask;
+	u32			mult;
+	u32			shift;
+	u64			max_idle_ns;
+	u32			maxadj;
 #ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
 	struct arch_clocksource_data archdata;
 #endif
-	u64 max_cycles;
-	const char *name;
-	struct list_head list;
-	int rating;
-	int (*enable)(struct clocksource *cs);
-	void (*disable)(struct clocksource *cs);
-	unsigned long flags;
-	void (*suspend)(struct clocksource *cs);
-	void (*resume)(struct clocksource *cs);
-	void (*mark_unstable)(struct clocksource *cs);
-	void (*tick_stable)(struct clocksource *cs);
+	u64			max_cycles;
+	const char		*name;
+	struct list_head	list;
+	int			rating;
+	unsigned long		flags;
+
+	int			(*enable)(struct clocksource *cs);
+	void			(*disable)(struct clocksource *cs);
+	void			(*suspend)(struct clocksource *cs);
+	void			(*resume)(struct clocksource *cs);
+	void			(*mark_unstable)(struct clocksource *cs);
+	void			(*tick_stable)(struct clocksource *cs);
 
 	/* private: */
 #ifdef CONFIG_CLOCKSOURCE_WATCHDOG
 	/* Watchdog related data, used by the framework */
-	struct list_head wd_list;
-	u64 cs_last;
-	u64 wd_last;
+	struct list_head	wd_list;
+	u64			cs_last;
+	u64			wd_last;
 #endif
-	struct module *owner;
+	struct module		*owner;
 };
 
 /*

Re: [patch V2 06/17] clocksource: Cleanup struct clocksource and documentation

[Vincenzo Frascino]

On 2/7/20 12:38 PM, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> Reformat the struct definition, add missing member documentation.
> No functional change.
>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> 
[...]

-- 
Regards,
Vincenzo

[tip: timers/core] clocksource: Cleanup struct clocksource and documentation

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     3bd142a46b561a12408e8db78cc6d62eb1c6b84e
Gitweb:        https://git.kernel.org/tip/3bd142a46b561a12408e8db78cc6d62eb1c6b84e
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:53 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:22 +01:00

clocksource: Cleanup struct clocksource and documentation

Reformat the struct definition, add missing member documentation.
No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124402.825471920@linutronix.de


---
 include/linux/clocksource.h | 87 +++++++++++++++++++-----------------
 1 file changed, 47 insertions(+), 40 deletions(-)

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index b21db53..2c4574b 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -32,9 +32,19 @@ struct module;
  *	Provides mostly state-free accessors to the underlying hardware.
  *	This is the structure used for system time.
  *
- * @name:		ptr to clocksource name
- * @list:		list head for registration
- * @rating:		rating value for selection (higher is better)
+ * @read:		Returns a cycle value, passes clocksource as argument
+ * @mask:		Bitmask for two's complement
+ *			subtraction of non 64 bit counters
+ * @mult:		Cycle to nanosecond multiplier
+ * @shift:		Cycle to nanosecond divisor (power of two)
+ * @max_idle_ns:	Maximum idle time permitted by the clocksource (nsecs)
+ * @maxadj:		Maximum adjustment value to mult (~11%)
+ * @archdata:		Optional arch-specific data
+ * @max_cycles:		Maximum safe cycle value which won't overflow on
+ *			multiplication
+ * @name:		Pointer to clocksource name
+ * @list:		List head for registration (internal)
+ * @rating:		Rating value for selection (higher is better)
  *			To avoid rating inflation the following
  *			list should give you a guide as to how
  *			to assign your clocksource a rating
@@ -49,27 +59,23 @@ struct module;
  *			400-499: Perfect
  *				The ideal clocksource. A must-use where
  *				available.
- * @read:		returns a cycle value, passes clocksource as argument
- * @enable:		optional function to enable the clocksource
- * @disable:		optional function to disable the clocksource
- * @mask:		bitmask for two's complement
- *			subtraction of non 64 bit counters
- * @mult:		cycle to nanosecond multiplier
- * @shift:		cycle to nanosecond divisor (power of two)
- * @max_idle_ns:	max idle time permitted by the clocksource (nsecs)
- * @maxadj:		maximum adjustment value to mult (~11%)
- * @max_cycles:		maximum safe cycle value which won't overflow on multiplication
- * @flags:		flags describing special properties
- * @archdata:		arch-specific data
- * @suspend:		suspend function for the clocksource, if necessary
- * @resume:		resume function for the clocksource, if necessary
+ * @flags:		Flags describing special properties
+ * @enable:		Optional function to enable the clocksource
+ * @disable:		Optional function to disable the clocksource
+ * @suspend:		Optional suspend function for the clocksource
+ * @resume:		Optional resume function for the clocksource
  * @mark_unstable:	Optional function to inform the clocksource driver that
  *			the watchdog marked the clocksource unstable
- * @owner:		module reference, must be set by clocksource in modules
+ * @tick_stable:        Optional function called periodically from the watchdog
+ *			code to provide stable syncrhonization points
+ * @wd_list:		List head to enqueue into the watchdog list (internal)
+ * @cs_last:		Last clocksource value for clocksource watchdog
+ * @wd_last:		Last watchdog value corresponding to @cs_last
+ * @owner:		Module reference, must be set by clocksource in modules
  *
  * Note: This struct is not used in hotpathes of the timekeeping code
  * because the timekeeper caches the hot path fields in its own data
- * structure, so no line cache alignment is required,
+ * structure, so no cache line alignment is required,
  *
  * The pointer to the clocksource itself is handed to the read
  * callback. If you need extra information there you can wrap struct
@@ -78,35 +84,36 @@ struct module;
  * structure.
  */
 struct clocksource {
-	u64 (*read)(struct clocksource *cs);
-	u64 mask;
-	u32 mult;
-	u32 shift;
-	u64 max_idle_ns;
-	u32 maxadj;
+	u64			(*read)(struct clocksource *cs);
+	u64			mask;
+	u32			mult;
+	u32			shift;
+	u64			max_idle_ns;
+	u32			maxadj;
 #ifdef CONFIG_ARCH_CLOCKSOURCE_DATA
 	struct arch_clocksource_data archdata;
 #endif
-	u64 max_cycles;
-	const char *name;
-	struct list_head list;
-	int rating;
-	int (*enable)(struct clocksource *cs);
-	void (*disable)(struct clocksource *cs);
-	unsigned long flags;
-	void (*suspend)(struct clocksource *cs);
-	void (*resume)(struct clocksource *cs);
-	void (*mark_unstable)(struct clocksource *cs);
-	void (*tick_stable)(struct clocksource *cs);
+	u64			max_cycles;
+	const char		*name;
+	struct list_head	list;
+	int			rating;
+	unsigned long		flags;
+
+	int			(*enable)(struct clocksource *cs);
+	void			(*disable)(struct clocksource *cs);
+	void			(*suspend)(struct clocksource *cs);
+	void			(*resume)(struct clocksource *cs);
+	void			(*mark_unstable)(struct clocksource *cs);
+	void			(*tick_stable)(struct clocksource *cs);
 
 	/* private: */
 #ifdef CONFIG_CLOCKSOURCE_WATCHDOG
 	/* Watchdog related data, used by the framework */
-	struct list_head wd_list;
-	u64 cs_last;
-	u64 wd_last;
+	struct list_head	wd_list;
+	u64			cs_last;
+	u64			wd_last;
 #endif
-	struct module *owner;
+	struct module		*owner;
 };
 
 /*

[patch V2 07/17] x86/vdso: Move VDSO clocksource state tracking to callback

[Thomas Gleixner]

From: Thomas Gleixner <tglx@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.

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)
Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)

---
 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(-)

--- 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(voi
 }
 #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 @@ static __init int vdso_setup(char *s)
 
 static int __init init_vdso(void)
 {
+	BUILD_BUG_ON(VCLOCK_MAX >= 32);
+
 	init_vdso_image(&vdso_image_64);
 
 #ifdef CONFIG_X86_X32_ABI
--- 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 */
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -47,6 +47,8 @@ typedef int (*hyperv_fill_flush_list_fun
 	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);
--- 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(
 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
 
--- 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 */
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -159,12 +159,19 @@ bool kvm_check_and_clear_guest_paused(vo
 	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);
 
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1108,17 +1108,24 @@ static void tsc_cs_tick_stable(struct cl
 		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_ts
  * 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,
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -145,12 +145,19 @@ static struct notifier_block xen_pvclock
 	.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,
 };
 
 /*
--- a/drivers/clocksource/hyperv_timer.c
+++ b/drivers/clocksource/hyperv_timer.c
@@ -369,6 +369,12 @@ static void resume_hv_clock_tsc(struct c
 	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)

Re: [patch V2 07/17] x86/vdso: Move VDSO clocksource state tracking to callback

[Vincenzo Frascino]

On 2/7/20 12:38 PM, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@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.
> 
> 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)
> Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)
>

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> (VDSO parts)

> ---
>  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(-)
> 
> --- 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(voi
>  }
>  #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 @@ static __init int vdso_setup(char *s)
>  
>  static int __init init_vdso(void)
>  {
> +	BUILD_BUG_ON(VCLOCK_MAX >= 32);
> +
>  	init_vdso_image(&vdso_image_64);
>  
>  #ifdef CONFIG_X86_X32_ABI
> --- 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 */
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -47,6 +47,8 @@ typedef int (*hyperv_fill_flush_list_fun
>  	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);
> --- 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(
>  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
>  
> --- 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 */
> --- a/arch/x86/kernel/kvmclock.c
> +++ b/arch/x86/kernel/kvmclock.c
> @@ -159,12 +159,19 @@ bool kvm_check_and_clear_guest_paused(vo
>  	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);
>  
> --- a/arch/x86/kernel/tsc.c
> +++ b/arch/x86/kernel/tsc.c
> @@ -1108,17 +1108,24 @@ static void tsc_cs_tick_stable(struct cl
>  		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_ts
>   * 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,
> --- a/arch/x86/xen/time.c
> +++ b/arch/x86/xen/time.c
> @@ -145,12 +145,19 @@ static struct notifier_block xen_pvclock
>  	.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,
>  };
>  
>  /*
> --- a/drivers/clocksource/hyperv_timer.c
> +++ b/drivers/clocksource/hyperv_timer.c
> @@ -369,6 +369,12 @@ static void resume_hv_clock_tsc(struct c
>  	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)
> 

-- 
Regards,
Vincenzo

[tip: timers/core] x86/vdso: Move VDSO clocksource state tracking to callback

[tip-bot2 for Thomas Gleixner]

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)

[patch V2 08/17] clocksource: Add common vdso clock mode storage

[Thomas Gleixner]

From: Thomas Gleixner <tglx@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>
---
V2: Fix the unused variable warning and s/mode/clock_mode/ - Christophe
---
 include/linux/clocksource.h |   12 +++++++++++-
 kernel/time/clocksource.c   |    9 +++++++++
 kernel/time/vsyscall.c      |   10 ++++++++--
 lib/vdso/Kconfig            |    3 +++
 lib/vdso/gettimeofday.c     |   13 +++++++++++--
 5 files changed, 42 insertions(+), 5 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
@@ -928,6 +928,15 @@ 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
@@ -71,13 +71,19 @@ void update_vsyscall(struct timekeeper *
 {
 	struct vdso_data *vdata = __arch_get_k_vdso_data();
 	struct vdso_timestamp *vdso_ts;
+	s32 clock_mode;
 	u64 nsec;
 
 	/* copy vsyscall data */
 	vdso_write_begin(vdata);
 
-	vdata[CS_HRES_COARSE].clock_mode	= __arch_get_clock_mode(tk);
-	vdata[CS_RAW].clock_mode		= __arch_get_clock_mode(tk);
+#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+	clock_mode = tk->tkr_mono.clock->vdso_clock_mode;
+#else
+	clock_mode = __arch_get_clock_mode(tk);
+#endif
+	vdata[CS_HRES_COARSE].clock_mode	= clock_mode;
+	vdata[CS_RAW].clock_mode		= clock_mode;
 
 	/* 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);

Re: [patch V2 08/17] clocksource: Add common vdso clock mode storage

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 1719 bytes --]

Hi Thomas,

On 07/02/2020 12:38, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@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>


Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

> ---
> V2: Fix the unused variable warning and s/mode/clock_mode/ - Christophe
> ---
>  include/linux/clocksource.h |   12 +++++++++++-
>  kernel/time/clocksource.c   |    9 +++++++++
>  kernel/time/vsyscall.c      |   10 ++++++++--
>  lib/vdso/Kconfig            |    3 +++
>  lib/vdso/gettimeofday.c     |   13 +++++++++++--
>  5 files changed, 42 insertions(+), 5 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,
> +};
> +
As part of my work on common headers I will move this enumeration in
common/clocksource.h to be accessible by the vdso library. It will appear
in the next version of my patches once I rebase on yours.

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[tip: timers/core] clocksource: Add common vdso clock mode storage

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     5d51bee725cc1497352d6b0b604e42a90c680540
Gitweb:        https://git.kernel.org/tip/5d51bee725cc1497352d6b0b604e42a90c680540
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:55 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:23 +01:00

clocksource: Add common vdso clock mode storage

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>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.028046322@linutronix.de

---
 include/linux/clocksource.h | 12 +++++++++++-
 kernel/time/clocksource.c   |  9 +++++++++
 kernel/time/vsyscall.c      | 10 ++++++++--
 lib/vdso/Kconfig            |  3 +++
 lib/vdso/gettimeofday.c     | 13 +++++++++++--
 5 files changed, 42 insertions(+), 5 deletions(-)

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 2c4574b..6d5ed1b 100644
--- 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);
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 428beb6..7cb09c4 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -928,6 +928,15 @@ int __clocksource_register_scale(struct clocksource *cs, u32 scale, u32 freq)
 
 	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);
 
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index 9577c89..f9a5178 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -71,13 +71,19 @@ void update_vsyscall(struct timekeeper *tk)
 {
 	struct vdso_data *vdata = __arch_get_k_vdso_data();
 	struct vdso_timestamp *vdso_ts;
+	s32 clock_mode;
 	u64 nsec;
 
 	/* copy vsyscall data */
 	vdso_write_begin(vdata);
 
-	vdata[CS_HRES_COARSE].clock_mode	= __arch_get_clock_mode(tk);
-	vdata[CS_RAW].clock_mode		= __arch_get_clock_mode(tk);
+#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+	clock_mode = tk->tkr_mono.clock->vdso_clock_mode;
+#else
+	clock_mode = __arch_get_clock_mode(tk);
+#endif
+	vdata[CS_HRES_COARSE].clock_mode	= clock_mode;
+	vdata[CS_RAW].clock_mode		= clock_mode;
 
 	/* CLOCK_REALTIME also required for time() */
 	vdso_ts		= &vdata[CS_HRES_COARSE].basetime[CLOCK_REALTIME];
diff --git a/lib/vdso/Kconfig b/lib/vdso/Kconfig
index d883ac2..d9f43c8 100644
--- 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
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index 5804e4e..3f2d8b8 100644
--- 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 vdso_data *vdns, clockid_t clk,
 
 	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 struct vdso_data *vd, clockid_t clk,
 		}
 		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);

[patch V2 09/17] x86/vdso: Use generic VDSO clock mode storage

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

Switch to the generic VDSO clock mode storage.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)

---
 arch/x86/Kconfig                         |    2 +-
 arch/x86/entry/vdso/vma.c                |    6 +++---
 arch/x86/include/asm/clocksource.h       |   13 ++++---------
 arch/x86/include/asm/mshyperv.h          |    4 ++--
 arch/x86/include/asm/vdso/gettimeofday.h |    6 +++---
 arch/x86/include/asm/vdso/vsyscall.h     |    7 -------
 arch/x86/kernel/kvmclock.c               |    4 ++--
 arch/x86/kernel/pvclock.c                |    2 +-
 arch/x86/kernel/time.c                   |   12 +++---------
 arch/x86/kernel/tsc.c                    |    6 +++---
 arch/x86/kvm/trace.h                     |    4 ++--
 arch/x86/kvm/x86.c                       |   22 +++++++++++-----------
 arch/x86/xen/time.c                      |   21 +++++++++++----------
 13 files changed, 46 insertions(+), 63 deletions(-)

--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -57,7 +57,6 @@ config X86
 	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
 	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
 	select ARCH_32BIT_OFF_T			if X86_32
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_CLOCKSOURCE_INIT
 	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
 	select ARCH_HAS_DEBUG_VIRTUAL
@@ -126,6 +125,7 @@ config X86
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_VDSO_CLOCK_MODE
 	select GENERIC_VDSO_TIME_NS
 	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
 	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -221,7 +221,7 @@ static vm_fault_t vvar_fault(const struc
 	} else if (sym_offset == image->sym_pvclock_page) {
 		struct pvclock_vsyscall_time_info *pvti =
 			pvclock_get_pvti_cpu0_va();
-		if (pvti && vclock_was_used(VCLOCK_PVCLOCK)) {
+		if (pvti && vclock_was_used(VDSO_CLOCKMODE_PVCLOCK)) {
 			return vmf_insert_pfn_prot(vma, vmf->address,
 					__pa(pvti) >> PAGE_SHIFT,
 					pgprot_decrypted(vma->vm_page_prot));
@@ -229,7 +229,7 @@ static vm_fault_t vvar_fault(const struc
 	} else if (sym_offset == image->sym_hvclock_page) {
 		struct ms_hyperv_tsc_page *tsc_pg = hv_get_tsc_page();
 
-		if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK))
+		if (tsc_pg && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK))
 			return vmf_insert_pfn(vma, vmf->address,
 					virt_to_phys(tsc_pg) >> PAGE_SHIFT);
 	} else if (sym_offset == image->sym_timens_page) {
@@ -447,7 +447,7 @@ static __init int vdso_setup(char *s)
 
 static int __init init_vdso(void)
 {
-	BUILD_BUG_ON(VCLOCK_MAX >= 32);
+	BUILD_BUG_ON(VDSO_CLOCKMODE_MAX >= 32);
 
 	init_vdso_image(&vdso_image_64);
 
--- a/arch/x86/include/asm/clocksource.h
+++ b/arch/x86/include/asm/clocksource.h
@@ -4,15 +4,10 @@
 #ifndef _ASM_X86_CLOCKSOURCE_H
 #define _ASM_X86_CLOCKSOURCE_H
 
-#define VCLOCK_NONE	0	/* No vDSO clock available.		*/
-#define VCLOCK_TSC	1	/* vDSO should use vread_tsc.		*/
-#define VCLOCK_PVCLOCK	2	/* vDSO should use vread_pvclock.	*/
-#define VCLOCK_HVCLOCK	3	/* vDSO should use vread_hvclock.	*/
-#define VCLOCK_MAX	3
-
-struct arch_clocksource_data {
-	int vclock_mode;
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_TSC,	\
+	VDSO_CLOCKMODE_PVCLOCK,	\
+	VDSO_CLOCKMODE_HVCLOCK
 
 extern unsigned int vclocks_used;
 
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -46,9 +46,9 @@ typedef int (*hyperv_fill_flush_list_fun
 #define hv_set_reference_tsc(val) \
 	wrmsrl(HV_X64_MSR_REFERENCE_TSC, val)
 #define hv_set_clocksource_vdso(val) \
-	((val).archdata.vclock_mode = VCLOCK_HVCLOCK)
+	((val).vdso_clock_mode = VDSO_CLOCKMODE_HVCLOCK)
 #define hv_enable_vdso_clocksource() \
-	vclocks_set_used(VCLOCK_HVCLOCK);
+	vclocks_set_used(VDSO_CLOCKMODE_HVCLOCK);
 #define hv_get_raw_timer() rdtsc_ordered()
 
 void hyperv_callback_vector(void);
--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -243,7 +243,7 @@ static u64 vread_hvclock(void)
 
 static inline u64 __arch_get_hw_counter(s32 clock_mode)
 {
-	if (likely(clock_mode == VCLOCK_TSC))
+	if (likely(clock_mode == VDSO_CLOCKMODE_TSC))
 		return (u64)rdtsc_ordered();
 	/*
 	 * For any memory-mapped vclock type, we need to make sure that gcc
@@ -252,13 +252,13 @@ static inline u64 __arch_get_hw_counter(
 	 * question isn't enabled, which will segfault.  Hence the barriers.
 	 */
 #ifdef CONFIG_PARAVIRT_CLOCK
-	if (clock_mode == VCLOCK_PVCLOCK) {
+	if (clock_mode == VDSO_CLOCKMODE_PVCLOCK) {
 		barrier();
 		return vread_pvclock();
 	}
 #endif
 #ifdef CONFIG_HYPERV_TIMER
-	if (clock_mode == VCLOCK_HVCLOCK) {
+	if (clock_mode == VDSO_CLOCKMODE_HVCLOCK) {
 		barrier();
 		return vread_hvclock();
 	}
--- a/arch/x86/include/asm/vdso/vsyscall.h
+++ b/arch/x86/include/asm/vdso/vsyscall.h
@@ -21,13 +21,6 @@ struct vdso_data *__x86_get_k_vdso_data(
 }
 #define __arch_get_k_vdso_data __x86_get_k_vdso_data
 
-static __always_inline
-int __x86_get_clock_mode(struct timekeeper *tk)
-{
-	return tk->tkr_mono.clock->archdata.vclock_mode;
-}
-#define __arch_get_clock_mode __x86_get_clock_mode
-
 /* The asm-generic header needs to be included after the definitions above */
 #include <asm-generic/vdso/vsyscall.h>
 
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -161,7 +161,7 @@ bool kvm_check_and_clear_guest_paused(vo
 
 static int kvm_cs_enable(struct clocksource *cs)
 {
-	vclocks_set_used(VCLOCK_PVCLOCK);
+	vclocks_set_used(VDSO_CLOCKMODE_PVCLOCK);
 	return 0;
 }
 
@@ -279,7 +279,7 @@ static int __init kvm_setup_vsyscall_tim
 	if (!(flags & PVCLOCK_TSC_STABLE_BIT))
 		return 0;
 
-	kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK;
+	kvm_clock.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK;
 #endif
 
 	kvmclock_init_mem();
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -145,7 +145,7 @@ void pvclock_read_wallclock(struct pvclo
 
 void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti)
 {
-	WARN_ON(vclock_was_used(VCLOCK_PVCLOCK));
+	WARN_ON(vclock_was_used(VDSO_CLOCKMODE_PVCLOCK));
 	pvti_cpu0_va = pvti;
 }
 
--- a/arch/x86/kernel/time.c
+++ b/arch/x86/kernel/time.c
@@ -114,18 +114,12 @@ void __init time_init(void)
  */
 void clocksource_arch_init(struct clocksource *cs)
 {
-	if (cs->archdata.vclock_mode == VCLOCK_NONE)
+	if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE)
 		return;
 
-	if (cs->archdata.vclock_mode > VCLOCK_MAX) {
-		pr_warn("clocksource %s registered with invalid vclock_mode %d. Disabling vclock.\n",
-			cs->name, cs->archdata.vclock_mode);
-		cs->archdata.vclock_mode = VCLOCK_NONE;
-	}
-
 	if (cs->mask != CLOCKSOURCE_MASK(64)) {
-		pr_warn("clocksource %s registered with invalid mask %016llx. Disabling vclock.\n",
+		pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n",
 			cs->name, cs->mask);
-		cs->archdata.vclock_mode = VCLOCK_NONE;
+		cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
 	}
 }
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1110,7 +1110,7 @@ static void tsc_cs_tick_stable(struct cl
 
 static int tsc_cs_enable(struct clocksource *cs)
 {
-	vclocks_set_used(VCLOCK_TSC);
+	vclocks_set_used(VDSO_CLOCKMODE_TSC);
 	return 0;
 }
 
@@ -1124,7 +1124,7 @@ static struct clocksource clocksource_ts
 	.mask			= CLOCKSOURCE_MASK(64),
 	.flags			= CLOCK_SOURCE_IS_CONTINUOUS |
 				  CLOCK_SOURCE_MUST_VERIFY,
-	.archdata		= { .vclock_mode = VCLOCK_TSC },
+	.vdso_clock_mode	= VDSO_CLOCKMODE_TSC,
 	.enable			= tsc_cs_enable,
 	.resume			= tsc_resume,
 	.mark_unstable		= tsc_cs_mark_unstable,
@@ -1145,7 +1145,7 @@ static struct clocksource clocksource_ts
 	.flags			= CLOCK_SOURCE_IS_CONTINUOUS |
 				  CLOCK_SOURCE_VALID_FOR_HRES |
 				  CLOCK_SOURCE_MUST_VERIFY,
-	.archdata		= { .vclock_mode = VCLOCK_TSC },
+	.vdso_clock_mode	= VDSO_CLOCKMODE_TSC,
 	.enable			= tsc_cs_enable,
 	.resume			= tsc_resume,
 	.mark_unstable		= tsc_cs_mark_unstable,
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -815,8 +815,8 @@ TRACE_EVENT(kvm_write_tsc_offset,
 #ifdef CONFIG_X86_64
 
 #define host_clocks					\
-	{VCLOCK_NONE, "none"},				\
-	{VCLOCK_TSC,  "tsc"}				\
+	{VDSO_CLOCKMODE_NONE, "none"},			\
+	{VDSO_CLOCKMODE_TSC,  "tsc"}			\
 
 TRACE_EVENT(kvm_update_master_clock,
 	TP_PROTO(bool use_master_clock, unsigned int host_clock, bool offset_matched),
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1635,7 +1635,7 @@ static void update_pvclock_gtod(struct t
 	write_seqcount_begin(&vdata->seq);
 
 	/* copy pvclock gtod data */
-	vdata->clock.vclock_mode	= tk->tkr_mono.clock->archdata.vclock_mode;
+	vdata->clock.vclock_mode	= tk->tkr_mono.clock->vdso_clock_mode;
 	vdata->clock.cycle_last		= tk->tkr_mono.cycle_last;
 	vdata->clock.mask		= tk->tkr_mono.mask;
 	vdata->clock.mult		= tk->tkr_mono.mult;
@@ -1643,7 +1643,7 @@ static void update_pvclock_gtod(struct t
 	vdata->clock.base_cycles	= tk->tkr_mono.xtime_nsec;
 	vdata->clock.offset		= tk->tkr_mono.base;
 
-	vdata->raw_clock.vclock_mode	= tk->tkr_raw.clock->archdata.vclock_mode;
+	vdata->raw_clock.vclock_mode	= tk->tkr_raw.clock->vdso_clock_mode;
 	vdata->raw_clock.cycle_last	= tk->tkr_raw.cycle_last;
 	vdata->raw_clock.mask		= tk->tkr_raw.mask;
 	vdata->raw_clock.mult		= tk->tkr_raw.mult;
@@ -1844,7 +1844,7 @@ static u64 compute_guest_tsc(struct kvm_
 
 static inline int gtod_is_based_on_tsc(int mode)
 {
-	return mode == VCLOCK_TSC || mode == VCLOCK_HVCLOCK;
+	return mode == VDSO_CLOCKMODE_TSC || mode == VDSO_CLOCKMODE_HVCLOCK;
 }
 
 static void kvm_track_tsc_matching(struct kvm_vcpu *vcpu)
@@ -1937,7 +1937,7 @@ static inline bool kvm_check_tsc_unstabl
 	 * TSC is marked unstable when we're running on Hyper-V,
 	 * 'TSC page' clocksource is good.
 	 */
-	if (pvclock_gtod_data.clock.vclock_mode == VCLOCK_HVCLOCK)
+	if (pvclock_gtod_data.clock.vclock_mode == VDSO_CLOCKMODE_HVCLOCK)
 		return false;
 #endif
 	return check_tsc_unstable();
@@ -2092,30 +2092,30 @@ static inline u64 vgettsc(struct pvclock
 	u64 tsc_pg_val;
 
 	switch (clock->vclock_mode) {
-	case VCLOCK_HVCLOCK:
+	case VDSO_CLOCKMODE_HVCLOCK:
 		tsc_pg_val = hv_read_tsc_page_tsc(hv_get_tsc_page(),
 						  tsc_timestamp);
 		if (tsc_pg_val != U64_MAX) {
 			/* TSC page valid */
-			*mode = VCLOCK_HVCLOCK;
+			*mode = VDSO_CLOCKMODE_HVCLOCK;
 			v = (tsc_pg_val - clock->cycle_last) &
 				clock->mask;
 		} else {
 			/* TSC page invalid */
-			*mode = VCLOCK_NONE;
+			*mode = VDSO_CLOCKMODE_NONE;
 		}
 		break;
-	case VCLOCK_TSC:
-		*mode = VCLOCK_TSC;
+	case VDSO_CLOCKMODE_TSC:
+		*mode = VDSO_CLOCKMODE_TSC;
 		*tsc_timestamp = read_tsc();
 		v = (*tsc_timestamp - clock->cycle_last) &
 			clock->mask;
 		break;
 	default:
-		*mode = VCLOCK_NONE;
+		*mode = VDSO_CLOCKMODE_NONE;
 	}
 
-	if (*mode == VCLOCK_NONE)
+	if (*mode == VDSO_CLOCKMODE_NONE)
 		*tsc_timestamp = v = 0;
 
 	return v * clock->mult;
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -147,7 +147,7 @@ static struct notifier_block xen_pvclock
 
 static int xen_cs_enable(struct clocksource *cs)
 {
-	vclocks_set_used(VCLOCK_PVCLOCK);
+	vclocks_set_used(VDSO_CLOCKMODE_PVCLOCK);
 	return 0;
 }
 
@@ -419,12 +419,13 @@ void xen_restore_time_memory_area(void)
 	ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t);
 
 	/*
-	 * We don't disable VCLOCK_PVCLOCK entirely if it fails to register the
-	 * secondary time info with Xen or if we migrated to a host without the
-	 * necessary flags. On both of these cases what happens is either
-	 * process seeing a zeroed out pvti or seeing no PVCLOCK_TSC_STABLE_BIT
-	 * bit set. Userspace checks the latter and if 0, it discards the data
-	 * in pvti and fallbacks to a system call for a reliable timestamp.
+	 * We don't disable VDSO_CLOCKMODE_PVCLOCK entirely if it fails to
+	 * register the secondary time info with Xen or if we migrated to a
+	 * host without the necessary flags. On both of these cases what
+	 * happens is either process seeing a zeroed out pvti or seeing no
+	 * PVCLOCK_TSC_STABLE_BIT bit set. Userspace checks the latter and
+	 * if 0, it discards the data in pvti and fallbacks to a system
+	 * call for a reliable timestamp.
 	 */
 	if (ret != 0)
 		pr_notice("Cannot restore secondary vcpu_time_info (err %d)",
@@ -450,7 +451,7 @@ static void xen_setup_vsyscall_time_info
 
 	ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t);
 	if (ret) {
-		pr_notice("xen: VCLOCK_PVCLOCK not supported (err %d)\n", ret);
+		pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (err %d)\n", ret);
 		free_page((unsigned long)ti);
 		return;
 	}
@@ -467,14 +468,14 @@ static void xen_setup_vsyscall_time_info
 		if (!ret)
 			free_page((unsigned long)ti);
 
-		pr_notice("xen: VCLOCK_PVCLOCK not supported (tsc unstable)\n");
+		pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (tsc unstable)\n");
 		return;
 	}
 
 	xen_clock = ti;
 	pvclock_set_pvti_cpu0_va(xen_clock);
 
-	xen_clocksource.archdata.vclock_mode = VCLOCK_PVCLOCK;
+	xen_clocksource.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK;
 }
 
 static void __init xen_time_init(void)

Re: [patch V2 09/17] x86/vdso: Use generic VDSO clock mode storage

[Paolo Bonzini]

On 07/02/20 13:38, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> Switch to the generic VDSO clock mode storage.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)

Acked-by: Paolo Bonzini <pbonzini@redhat.com> (KVM parts)

Thanks,

Paolo

> ---
>  arch/x86/Kconfig                         |    2 +-
>  arch/x86/entry/vdso/vma.c                |    6 +++---
>  arch/x86/include/asm/clocksource.h       |   13 ++++---------
>  arch/x86/include/asm/mshyperv.h          |    4 ++--
>  arch/x86/include/asm/vdso/gettimeofday.h |    6 +++---
>  arch/x86/include/asm/vdso/vsyscall.h     |    7 -------
>  arch/x86/kernel/kvmclock.c               |    4 ++--
>  arch/x86/kernel/pvclock.c                |    2 +-
>  arch/x86/kernel/time.c                   |   12 +++---------
>  arch/x86/kernel/tsc.c                    |    6 +++---
>  arch/x86/kvm/trace.h                     |    4 ++--
>  arch/x86/kvm/x86.c                       |   22 +++++++++++-----------
>  arch/x86/xen/time.c                      |   21 +++++++++++----------
>  13 files changed, 46 insertions(+), 63 deletions(-)
> 
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -57,7 +57,6 @@ config X86
>  	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
>  	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
>  	select ARCH_32BIT_OFF_T			if X86_32
> -	select ARCH_CLOCKSOURCE_DATA
>  	select ARCH_CLOCKSOURCE_INIT
>  	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
>  	select ARCH_HAS_DEBUG_VIRTUAL
> @@ -126,6 +125,7 @@ config X86
>  	select GENERIC_STRNLEN_USER
>  	select GENERIC_TIME_VSYSCALL
>  	select GENERIC_GETTIMEOFDAY
> +	select GENERIC_VDSO_CLOCK_MODE
>  	select GENERIC_VDSO_TIME_NS
>  	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
>  	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
> --- a/arch/x86/entry/vdso/vma.c
> +++ b/arch/x86/entry/vdso/vma.c
> @@ -221,7 +221,7 @@ static vm_fault_t vvar_fault(const struc
>  	} else if (sym_offset == image->sym_pvclock_page) {
>  		struct pvclock_vsyscall_time_info *pvti =
>  			pvclock_get_pvti_cpu0_va();
> -		if (pvti && vclock_was_used(VCLOCK_PVCLOCK)) {
> +		if (pvti && vclock_was_used(VDSO_CLOCKMODE_PVCLOCK)) {
>  			return vmf_insert_pfn_prot(vma, vmf->address,
>  					__pa(pvti) >> PAGE_SHIFT,
>  					pgprot_decrypted(vma->vm_page_prot));
> @@ -229,7 +229,7 @@ static vm_fault_t vvar_fault(const struc
>  	} else if (sym_offset == image->sym_hvclock_page) {
>  		struct ms_hyperv_tsc_page *tsc_pg = hv_get_tsc_page();
>  
> -		if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK))
> +		if (tsc_pg && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK))
>  			return vmf_insert_pfn(vma, vmf->address,
>  					virt_to_phys(tsc_pg) >> PAGE_SHIFT);
>  	} else if (sym_offset == image->sym_timens_page) {
> @@ -447,7 +447,7 @@ static __init int vdso_setup(char *s)
>  
>  static int __init init_vdso(void)
>  {
> -	BUILD_BUG_ON(VCLOCK_MAX >= 32);
> +	BUILD_BUG_ON(VDSO_CLOCKMODE_MAX >= 32);
>  
>  	init_vdso_image(&vdso_image_64);
>  
> --- a/arch/x86/include/asm/clocksource.h
> +++ b/arch/x86/include/asm/clocksource.h
> @@ -4,15 +4,10 @@
>  #ifndef _ASM_X86_CLOCKSOURCE_H
>  #define _ASM_X86_CLOCKSOURCE_H
>  
> -#define VCLOCK_NONE	0	/* No vDSO clock available.		*/
> -#define VCLOCK_TSC	1	/* vDSO should use vread_tsc.		*/
> -#define VCLOCK_PVCLOCK	2	/* vDSO should use vread_pvclock.	*/
> -#define VCLOCK_HVCLOCK	3	/* vDSO should use vread_hvclock.	*/
> -#define VCLOCK_MAX	3
> -
> -struct arch_clocksource_data {
> -	int vclock_mode;
> -};
> +#define VDSO_ARCH_CLOCKMODES	\
> +	VDSO_CLOCKMODE_TSC,	\
> +	VDSO_CLOCKMODE_PVCLOCK,	\
> +	VDSO_CLOCKMODE_HVCLOCK
>  
>  extern unsigned int vclocks_used;
>  
> --- a/arch/x86/include/asm/mshyperv.h
> +++ b/arch/x86/include/asm/mshyperv.h
> @@ -46,9 +46,9 @@ typedef int (*hyperv_fill_flush_list_fun
>  #define hv_set_reference_tsc(val) \
>  	wrmsrl(HV_X64_MSR_REFERENCE_TSC, val)
>  #define hv_set_clocksource_vdso(val) \
> -	((val).archdata.vclock_mode = VCLOCK_HVCLOCK)
> +	((val).vdso_clock_mode = VDSO_CLOCKMODE_HVCLOCK)
>  #define hv_enable_vdso_clocksource() \
> -	vclocks_set_used(VCLOCK_HVCLOCK);
> +	vclocks_set_used(VDSO_CLOCKMODE_HVCLOCK);
>  #define hv_get_raw_timer() rdtsc_ordered()
>  
>  void hyperv_callback_vector(void);
> --- a/arch/x86/include/asm/vdso/gettimeofday.h
> +++ b/arch/x86/include/asm/vdso/gettimeofday.h
> @@ -243,7 +243,7 @@ static u64 vread_hvclock(void)
>  
>  static inline u64 __arch_get_hw_counter(s32 clock_mode)
>  {
> -	if (likely(clock_mode == VCLOCK_TSC))
> +	if (likely(clock_mode == VDSO_CLOCKMODE_TSC))
>  		return (u64)rdtsc_ordered();
>  	/*
>  	 * For any memory-mapped vclock type, we need to make sure that gcc
> @@ -252,13 +252,13 @@ static inline u64 __arch_get_hw_counter(
>  	 * question isn't enabled, which will segfault.  Hence the barriers.
>  	 */
>  #ifdef CONFIG_PARAVIRT_CLOCK
> -	if (clock_mode == VCLOCK_PVCLOCK) {
> +	if (clock_mode == VDSO_CLOCKMODE_PVCLOCK) {
>  		barrier();
>  		return vread_pvclock();
>  	}
>  #endif
>  #ifdef CONFIG_HYPERV_TIMER
> -	if (clock_mode == VCLOCK_HVCLOCK) {
> +	if (clock_mode == VDSO_CLOCKMODE_HVCLOCK) {
>  		barrier();
>  		return vread_hvclock();
>  	}
> --- a/arch/x86/include/asm/vdso/vsyscall.h
> +++ b/arch/x86/include/asm/vdso/vsyscall.h
> @@ -21,13 +21,6 @@ struct vdso_data *__x86_get_k_vdso_data(
>  }
>  #define __arch_get_k_vdso_data __x86_get_k_vdso_data
>  
> -static __always_inline
> -int __x86_get_clock_mode(struct timekeeper *tk)
> -{
> -	return tk->tkr_mono.clock->archdata.vclock_mode;
> -}
> -#define __arch_get_clock_mode __x86_get_clock_mode
> -
>  /* The asm-generic header needs to be included after the definitions above */
>  #include <asm-generic/vdso/vsyscall.h>
>  
> --- a/arch/x86/kernel/kvmclock.c
> +++ b/arch/x86/kernel/kvmclock.c
> @@ -161,7 +161,7 @@ bool kvm_check_and_clear_guest_paused(vo
>  
>  static int kvm_cs_enable(struct clocksource *cs)
>  {
> -	vclocks_set_used(VCLOCK_PVCLOCK);
> +	vclocks_set_used(VDSO_CLOCKMODE_PVCLOCK);
>  	return 0;
>  }
>  
> @@ -279,7 +279,7 @@ static int __init kvm_setup_vsyscall_tim
>  	if (!(flags & PVCLOCK_TSC_STABLE_BIT))
>  		return 0;
>  
> -	kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK;
> +	kvm_clock.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK;
>  #endif
>  
>  	kvmclock_init_mem();
> --- a/arch/x86/kernel/pvclock.c
> +++ b/arch/x86/kernel/pvclock.c
> @@ -145,7 +145,7 @@ void pvclock_read_wallclock(struct pvclo
>  
>  void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti)
>  {
> -	WARN_ON(vclock_was_used(VCLOCK_PVCLOCK));
> +	WARN_ON(vclock_was_used(VDSO_CLOCKMODE_PVCLOCK));
>  	pvti_cpu0_va = pvti;
>  }
>  
> --- a/arch/x86/kernel/time.c
> +++ b/arch/x86/kernel/time.c
> @@ -114,18 +114,12 @@ void __init time_init(void)
>   */
>  void clocksource_arch_init(struct clocksource *cs)
>  {
> -	if (cs->archdata.vclock_mode == VCLOCK_NONE)
> +	if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE)
>  		return;
>  
> -	if (cs->archdata.vclock_mode > VCLOCK_MAX) {
> -		pr_warn("clocksource %s registered with invalid vclock_mode %d. Disabling vclock.\n",
> -			cs->name, cs->archdata.vclock_mode);
> -		cs->archdata.vclock_mode = VCLOCK_NONE;
> -	}
> -
>  	if (cs->mask != CLOCKSOURCE_MASK(64)) {
> -		pr_warn("clocksource %s registered with invalid mask %016llx. Disabling vclock.\n",
> +		pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n",
>  			cs->name, cs->mask);
> -		cs->archdata.vclock_mode = VCLOCK_NONE;
> +		cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
>  	}
>  }
> --- a/arch/x86/kernel/tsc.c
> +++ b/arch/x86/kernel/tsc.c
> @@ -1110,7 +1110,7 @@ static void tsc_cs_tick_stable(struct cl
>  
>  static int tsc_cs_enable(struct clocksource *cs)
>  {
> -	vclocks_set_used(VCLOCK_TSC);
> +	vclocks_set_used(VDSO_CLOCKMODE_TSC);
>  	return 0;
>  }
>  
> @@ -1124,7 +1124,7 @@ static struct clocksource clocksource_ts
>  	.mask			= CLOCKSOURCE_MASK(64),
>  	.flags			= CLOCK_SOURCE_IS_CONTINUOUS |
>  				  CLOCK_SOURCE_MUST_VERIFY,
> -	.archdata		= { .vclock_mode = VCLOCK_TSC },
> +	.vdso_clock_mode	= VDSO_CLOCKMODE_TSC,
>  	.enable			= tsc_cs_enable,
>  	.resume			= tsc_resume,
>  	.mark_unstable		= tsc_cs_mark_unstable,
> @@ -1145,7 +1145,7 @@ static struct clocksource clocksource_ts
>  	.flags			= CLOCK_SOURCE_IS_CONTINUOUS |
>  				  CLOCK_SOURCE_VALID_FOR_HRES |
>  				  CLOCK_SOURCE_MUST_VERIFY,
> -	.archdata		= { .vclock_mode = VCLOCK_TSC },
> +	.vdso_clock_mode	= VDSO_CLOCKMODE_TSC,
>  	.enable			= tsc_cs_enable,
>  	.resume			= tsc_resume,
>  	.mark_unstable		= tsc_cs_mark_unstable,
> --- a/arch/x86/kvm/trace.h
> +++ b/arch/x86/kvm/trace.h
> @@ -815,8 +815,8 @@ TRACE_EVENT(kvm_write_tsc_offset,
>  #ifdef CONFIG_X86_64
>  
>  #define host_clocks					\
> -	{VCLOCK_NONE, "none"},				\
> -	{VCLOCK_TSC,  "tsc"}				\
> +	{VDSO_CLOCKMODE_NONE, "none"},			\
> +	{VDSO_CLOCKMODE_TSC,  "tsc"}			\
>  
>  TRACE_EVENT(kvm_update_master_clock,
>  	TP_PROTO(bool use_master_clock, unsigned int host_clock, bool offset_matched),
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -1635,7 +1635,7 @@ static void update_pvclock_gtod(struct t
>  	write_seqcount_begin(&vdata->seq);
>  
>  	/* copy pvclock gtod data */
> -	vdata->clock.vclock_mode	= tk->tkr_mono.clock->archdata.vclock_mode;
> +	vdata->clock.vclock_mode	= tk->tkr_mono.clock->vdso_clock_mode;
>  	vdata->clock.cycle_last		= tk->tkr_mono.cycle_last;
>  	vdata->clock.mask		= tk->tkr_mono.mask;
>  	vdata->clock.mult		= tk->tkr_mono.mult;
> @@ -1643,7 +1643,7 @@ static void update_pvclock_gtod(struct t
>  	vdata->clock.base_cycles	= tk->tkr_mono.xtime_nsec;
>  	vdata->clock.offset		= tk->tkr_mono.base;
>  
> -	vdata->raw_clock.vclock_mode	= tk->tkr_raw.clock->archdata.vclock_mode;
> +	vdata->raw_clock.vclock_mode	= tk->tkr_raw.clock->vdso_clock_mode;
>  	vdata->raw_clock.cycle_last	= tk->tkr_raw.cycle_last;
>  	vdata->raw_clock.mask		= tk->tkr_raw.mask;
>  	vdata->raw_clock.mult		= tk->tkr_raw.mult;
> @@ -1844,7 +1844,7 @@ static u64 compute_guest_tsc(struct kvm_
>  
>  static inline int gtod_is_based_on_tsc(int mode)
>  {
> -	return mode == VCLOCK_TSC || mode == VCLOCK_HVCLOCK;
> +	return mode == VDSO_CLOCKMODE_TSC || mode == VDSO_CLOCKMODE_HVCLOCK;
>  }
>  
>  static void kvm_track_tsc_matching(struct kvm_vcpu *vcpu)
> @@ -1937,7 +1937,7 @@ static inline bool kvm_check_tsc_unstabl
>  	 * TSC is marked unstable when we're running on Hyper-V,
>  	 * 'TSC page' clocksource is good.
>  	 */
> -	if (pvclock_gtod_data.clock.vclock_mode == VCLOCK_HVCLOCK)
> +	if (pvclock_gtod_data.clock.vclock_mode == VDSO_CLOCKMODE_HVCLOCK)
>  		return false;
>  #endif
>  	return check_tsc_unstable();
> @@ -2092,30 +2092,30 @@ static inline u64 vgettsc(struct pvclock
>  	u64 tsc_pg_val;
>  
>  	switch (clock->vclock_mode) {
> -	case VCLOCK_HVCLOCK:
> +	case VDSO_CLOCKMODE_HVCLOCK:
>  		tsc_pg_val = hv_read_tsc_page_tsc(hv_get_tsc_page(),
>  						  tsc_timestamp);
>  		if (tsc_pg_val != U64_MAX) {
>  			/* TSC page valid */
> -			*mode = VCLOCK_HVCLOCK;
> +			*mode = VDSO_CLOCKMODE_HVCLOCK;
>  			v = (tsc_pg_val - clock->cycle_last) &
>  				clock->mask;
>  		} else {
>  			/* TSC page invalid */
> -			*mode = VCLOCK_NONE;
> +			*mode = VDSO_CLOCKMODE_NONE;
>  		}
>  		break;
> -	case VCLOCK_TSC:
> -		*mode = VCLOCK_TSC;
> +	case VDSO_CLOCKMODE_TSC:
> +		*mode = VDSO_CLOCKMODE_TSC;
>  		*tsc_timestamp = read_tsc();
>  		v = (*tsc_timestamp - clock->cycle_last) &
>  			clock->mask;
>  		break;
>  	default:
> -		*mode = VCLOCK_NONE;
> +		*mode = VDSO_CLOCKMODE_NONE;
>  	}
>  
> -	if (*mode == VCLOCK_NONE)
> +	if (*mode == VDSO_CLOCKMODE_NONE)
>  		*tsc_timestamp = v = 0;
>  
>  	return v * clock->mult;
> --- a/arch/x86/xen/time.c
> +++ b/arch/x86/xen/time.c
> @@ -147,7 +147,7 @@ static struct notifier_block xen_pvclock
>  
>  static int xen_cs_enable(struct clocksource *cs)
>  {
> -	vclocks_set_used(VCLOCK_PVCLOCK);
> +	vclocks_set_used(VDSO_CLOCKMODE_PVCLOCK);
>  	return 0;
>  }
>  
> @@ -419,12 +419,13 @@ void xen_restore_time_memory_area(void)
>  	ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t);
>  
>  	/*
> -	 * We don't disable VCLOCK_PVCLOCK entirely if it fails to register the
> -	 * secondary time info with Xen or if we migrated to a host without the
> -	 * necessary flags. On both of these cases what happens is either
> -	 * process seeing a zeroed out pvti or seeing no PVCLOCK_TSC_STABLE_BIT
> -	 * bit set. Userspace checks the latter and if 0, it discards the data
> -	 * in pvti and fallbacks to a system call for a reliable timestamp.
> +	 * We don't disable VDSO_CLOCKMODE_PVCLOCK entirely if it fails to
> +	 * register the secondary time info with Xen or if we migrated to a
> +	 * host without the necessary flags. On both of these cases what
> +	 * happens is either process seeing a zeroed out pvti or seeing no
> +	 * PVCLOCK_TSC_STABLE_BIT bit set. Userspace checks the latter and
> +	 * if 0, it discards the data in pvti and fallbacks to a system
> +	 * call for a reliable timestamp.
>  	 */
>  	if (ret != 0)
>  		pr_notice("Cannot restore secondary vcpu_time_info (err %d)",
> @@ -450,7 +451,7 @@ static void xen_setup_vsyscall_time_info
>  
>  	ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t);
>  	if (ret) {
> -		pr_notice("xen: VCLOCK_PVCLOCK not supported (err %d)\n", ret);
> +		pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (err %d)\n", ret);
>  		free_page((unsigned long)ti);
>  		return;
>  	}
> @@ -467,14 +468,14 @@ static void xen_setup_vsyscall_time_info
>  		if (!ret)
>  			free_page((unsigned long)ti);
>  
> -		pr_notice("xen: VCLOCK_PVCLOCK not supported (tsc unstable)\n");
> +		pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (tsc unstable)\n");
>  		return;
>  	}
>  
>  	xen_clock = ti;
>  	pvclock_set_pvti_cpu0_va(xen_clock);
>  
> -	xen_clocksource.archdata.vclock_mode = VCLOCK_PVCLOCK;
> +	xen_clocksource.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK;
>  }
>  
>  static void __init xen_time_init(void)
> 

Re: [patch V2 09/17] x86/vdso: Use generic VDSO clock mode storage

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 376 bytes --]

On 07/02/2020 12:38, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> Switch to the generic VDSO clock mode storage.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)
> 

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> (VDSO parts)

[...]

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[tip: timers/core] x86/vdso: Use generic VDSO clock mode storage

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     b95a8a27c300d1a39a4e36f63a518ef36e4b966c
Gitweb:        https://git.kernel.org/tip/b95a8a27c300d1a39a4e36f63a518ef36e4b966c
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:56 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:23 +01:00

x86/vdso: Use generic VDSO clock mode storage

Switch to the generic VDSO clock mode storage.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com> (VDSO parts)
Acked-by: Juergen Gross <jgross@suse.com> (Xen parts)
Acked-by: Paolo Bonzini <pbonzini@redhat.com> (KVM parts)
Link: https://lkml.kernel.org/r/20200207124403.152039903@linutronix.de


---
 arch/x86/Kconfig                         |  2 +-
 arch/x86/entry/vdso/vma.c                |  6 +++---
 arch/x86/include/asm/clocksource.h       | 13 ++++---------
 arch/x86/include/asm/mshyperv.h          |  4 ++--
 arch/x86/include/asm/vdso/gettimeofday.h |  6 +++---
 arch/x86/include/asm/vdso/vsyscall.h     |  7 -------
 arch/x86/kernel/kvmclock.c               |  4 ++--
 arch/x86/kernel/pvclock.c                |  2 +-
 arch/x86/kernel/time.c                   | 12 +++---------
 arch/x86/kernel/tsc.c                    |  6 +++---
 arch/x86/kvm/trace.h                     |  4 ++--
 arch/x86/kvm/x86.c                       | 22 +++++++++++-----------
 arch/x86/xen/time.c                      | 21 +++++++++++----------
 13 files changed, 46 insertions(+), 63 deletions(-)

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index beea770..698e9c8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -57,7 +57,6 @@ config X86
 	select ACPI_LEGACY_TABLES_LOOKUP	if ACPI
 	select ACPI_SYSTEM_POWER_STATES_SUPPORT	if ACPI
 	select ARCH_32BIT_OFF_T			if X86_32
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_CLOCKSOURCE_INIT
 	select ARCH_HAS_ACPI_TABLE_UPGRADE	if ACPI
 	select ARCH_HAS_DEBUG_VIRTUAL
@@ -126,6 +125,7 @@ config X86
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_VDSO_CLOCK_MODE
 	select GENERIC_VDSO_TIME_NS
 	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
 	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index cce3e80..43428cc 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -221,7 +221,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 	} else if (sym_offset == image->sym_pvclock_page) {
 		struct pvclock_vsyscall_time_info *pvti =
 			pvclock_get_pvti_cpu0_va();
-		if (pvti && vclock_was_used(VCLOCK_PVCLOCK)) {
+		if (pvti && vclock_was_used(VDSO_CLOCKMODE_PVCLOCK)) {
 			return vmf_insert_pfn_prot(vma, vmf->address,
 					__pa(pvti) >> PAGE_SHIFT,
 					pgprot_decrypted(vma->vm_page_prot));
@@ -229,7 +229,7 @@ static vm_fault_t vvar_fault(const struct vm_special_mapping *sm,
 	} else if (sym_offset == image->sym_hvclock_page) {
 		struct ms_hyperv_tsc_page *tsc_pg = hv_get_tsc_page();
 
-		if (tsc_pg && vclock_was_used(VCLOCK_HVCLOCK))
+		if (tsc_pg && vclock_was_used(VDSO_CLOCKMODE_HVCLOCK))
 			return vmf_insert_pfn(vma, vmf->address,
 					virt_to_phys(tsc_pg) >> PAGE_SHIFT);
 	} else if (sym_offset == image->sym_timens_page) {
@@ -447,7 +447,7 @@ __setup("vdso=", vdso_setup);
 
 static int __init init_vdso(void)
 {
-	BUILD_BUG_ON(VCLOCK_MAX >= 32);
+	BUILD_BUG_ON(VDSO_CLOCKMODE_MAX >= 32);
 
 	init_vdso_image(&vdso_image_64);
 
diff --git a/arch/x86/include/asm/clocksource.h b/arch/x86/include/asm/clocksource.h
index 2450d6e..d561db6 100644
--- a/arch/x86/include/asm/clocksource.h
+++ b/arch/x86/include/asm/clocksource.h
@@ -4,15 +4,10 @@
 #ifndef _ASM_X86_CLOCKSOURCE_H
 #define _ASM_X86_CLOCKSOURCE_H
 
-#define VCLOCK_NONE	0	/* No vDSO clock available.		*/
-#define VCLOCK_TSC	1	/* vDSO should use vread_tsc.		*/
-#define VCLOCK_PVCLOCK	2	/* vDSO should use vread_pvclock.	*/
-#define VCLOCK_HVCLOCK	3	/* vDSO should use vread_hvclock.	*/
-#define VCLOCK_MAX	3
-
-struct arch_clocksource_data {
-	int vclock_mode;
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_TSC,	\
+	VDSO_CLOCKMODE_PVCLOCK,	\
+	VDSO_CLOCKMODE_HVCLOCK
 
 extern unsigned int vclocks_used;
 
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index f7cbc01..edc2c58 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -46,9 +46,9 @@ typedef int (*hyperv_fill_flush_list_func)(
 #define hv_set_reference_tsc(val) \
 	wrmsrl(HV_X64_MSR_REFERENCE_TSC, val)
 #define hv_set_clocksource_vdso(val) \
-	((val).archdata.vclock_mode = VCLOCK_HVCLOCK)
+	((val).vdso_clock_mode = VDSO_CLOCKMODE_HVCLOCK)
 #define hv_enable_vdso_clocksource() \
-	vclocks_set_used(VCLOCK_HVCLOCK);
+	vclocks_set_used(VDSO_CLOCKMODE_HVCLOCK);
 #define hv_get_raw_timer() rdtsc_ordered()
 
 void hyperv_callback_vector(void);
diff --git a/arch/x86/include/asm/vdso/gettimeofday.h b/arch/x86/include/asm/vdso/gettimeofday.h
index 264d4fd..9a6dc9b 100644
--- a/arch/x86/include/asm/vdso/gettimeofday.h
+++ b/arch/x86/include/asm/vdso/gettimeofday.h
@@ -243,7 +243,7 @@ static u64 vread_hvclock(void)
 
 static inline u64 __arch_get_hw_counter(s32 clock_mode)
 {
-	if (likely(clock_mode == VCLOCK_TSC))
+	if (likely(clock_mode == VDSO_CLOCKMODE_TSC))
 		return (u64)rdtsc_ordered();
 	/*
 	 * For any memory-mapped vclock type, we need to make sure that gcc
@@ -252,13 +252,13 @@ static inline u64 __arch_get_hw_counter(s32 clock_mode)
 	 * question isn't enabled, which will segfault.  Hence the barriers.
 	 */
 #ifdef CONFIG_PARAVIRT_CLOCK
-	if (clock_mode == VCLOCK_PVCLOCK) {
+	if (clock_mode == VDSO_CLOCKMODE_PVCLOCK) {
 		barrier();
 		return vread_pvclock();
 	}
 #endif
 #ifdef CONFIG_HYPERV_TIMER
-	if (clock_mode == VCLOCK_HVCLOCK) {
+	if (clock_mode == VDSO_CLOCKMODE_HVCLOCK) {
 		barrier();
 		return vread_hvclock();
 	}
diff --git a/arch/x86/include/asm/vdso/vsyscall.h b/arch/x86/include/asm/vdso/vsyscall.h
index 01f5733..be199a9 100644
--- a/arch/x86/include/asm/vdso/vsyscall.h
+++ b/arch/x86/include/asm/vdso/vsyscall.h
@@ -21,13 +21,6 @@ struct vdso_data *__x86_get_k_vdso_data(void)
 }
 #define __arch_get_k_vdso_data __x86_get_k_vdso_data
 
-static __always_inline
-int __x86_get_clock_mode(struct timekeeper *tk)
-{
-	return tk->tkr_mono.clock->archdata.vclock_mode;
-}
-#define __arch_get_clock_mode __x86_get_clock_mode
-
 /* The asm-generic header needs to be included after the definitions above */
 #include <asm-generic/vdso/vsyscall.h>
 
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 33f2cac..34b18f6 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -161,7 +161,7 @@ bool kvm_check_and_clear_guest_paused(void)
 
 static int kvm_cs_enable(struct clocksource *cs)
 {
-	vclocks_set_used(VCLOCK_PVCLOCK);
+	vclocks_set_used(VDSO_CLOCKMODE_PVCLOCK);
 	return 0;
 }
 
@@ -279,7 +279,7 @@ static int __init kvm_setup_vsyscall_timeinfo(void)
 	if (!(flags & PVCLOCK_TSC_STABLE_BIT))
 		return 0;
 
-	kvm_clock.archdata.vclock_mode = VCLOCK_PVCLOCK;
+	kvm_clock.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK;
 #endif
 
 	kvmclock_init_mem();
diff --git a/arch/x86/kernel/pvclock.c b/arch/x86/kernel/pvclock.c
index 1012535..11065dc 100644
--- a/arch/x86/kernel/pvclock.c
+++ b/arch/x86/kernel/pvclock.c
@@ -145,7 +145,7 @@ void pvclock_read_wallclock(struct pvclock_wall_clock *wall_clock,
 
 void pvclock_set_pvti_cpu0_va(struct pvclock_vsyscall_time_info *pvti)
 {
-	WARN_ON(vclock_was_used(VCLOCK_PVCLOCK));
+	WARN_ON(vclock_was_used(VDSO_CLOCKMODE_PVCLOCK));
 	pvti_cpu0_va = pvti;
 }
 
diff --git a/arch/x86/kernel/time.c b/arch/x86/kernel/time.c
index d8673d8..4d545db 100644
--- a/arch/x86/kernel/time.c
+++ b/arch/x86/kernel/time.c
@@ -122,18 +122,12 @@ void __init time_init(void)
  */
 void clocksource_arch_init(struct clocksource *cs)
 {
-	if (cs->archdata.vclock_mode == VCLOCK_NONE)
+	if (cs->vdso_clock_mode == VDSO_CLOCKMODE_NONE)
 		return;
 
-	if (cs->archdata.vclock_mode > VCLOCK_MAX) {
-		pr_warn("clocksource %s registered with invalid vclock_mode %d. Disabling vclock.\n",
-			cs->name, cs->archdata.vclock_mode);
-		cs->archdata.vclock_mode = VCLOCK_NONE;
-	}
-
 	if (cs->mask != CLOCKSOURCE_MASK(64)) {
-		pr_warn("clocksource %s registered with invalid mask %016llx. Disabling vclock.\n",
+		pr_warn("clocksource %s registered with invalid mask %016llx for VDSO. Disabling VDSO support.\n",
 			cs->name, cs->mask);
-		cs->archdata.vclock_mode = VCLOCK_NONE;
+		cs->vdso_clock_mode = VDSO_CLOCKMODE_NONE;
 	}
 }
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 742da14..971d6f0 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -1110,7 +1110,7 @@ static void tsc_cs_tick_stable(struct clocksource *cs)
 
 static int tsc_cs_enable(struct clocksource *cs)
 {
-	vclocks_set_used(VCLOCK_TSC);
+	vclocks_set_used(VDSO_CLOCKMODE_TSC);
 	return 0;
 }
 
@@ -1124,7 +1124,7 @@ static struct clocksource clocksource_tsc_early = {
 	.mask			= CLOCKSOURCE_MASK(64),
 	.flags			= CLOCK_SOURCE_IS_CONTINUOUS |
 				  CLOCK_SOURCE_MUST_VERIFY,
-	.archdata		= { .vclock_mode = VCLOCK_TSC },
+	.vdso_clock_mode	= VDSO_CLOCKMODE_TSC,
 	.enable			= tsc_cs_enable,
 	.resume			= tsc_resume,
 	.mark_unstable		= tsc_cs_mark_unstable,
@@ -1145,7 +1145,7 @@ static struct clocksource clocksource_tsc = {
 	.flags			= CLOCK_SOURCE_IS_CONTINUOUS |
 				  CLOCK_SOURCE_VALID_FOR_HRES |
 				  CLOCK_SOURCE_MUST_VERIFY,
-	.archdata		= { .vclock_mode = VCLOCK_TSC },
+	.vdso_clock_mode	= VDSO_CLOCKMODE_TSC,
 	.enable			= tsc_cs_enable,
 	.resume			= tsc_resume,
 	.mark_unstable		= tsc_cs_mark_unstable,
diff --git a/arch/x86/kvm/trace.h b/arch/x86/kvm/trace.h
index f194dd0..cef5a34 100644
--- a/arch/x86/kvm/trace.h
+++ b/arch/x86/kvm/trace.h
@@ -815,8 +815,8 @@ TRACE_EVENT(kvm_write_tsc_offset,
 #ifdef CONFIG_X86_64
 
 #define host_clocks					\
-	{VCLOCK_NONE, "none"},				\
-	{VCLOCK_TSC,  "tsc"}				\
+	{VDSO_CLOCKMODE_NONE, "none"},			\
+	{VDSO_CLOCKMODE_TSC,  "tsc"}			\
 
 TRACE_EVENT(kvm_update_master_clock,
 	TP_PROTO(bool use_master_clock, unsigned int host_clock, bool offset_matched),
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index fb5d64e..0e7ef29 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1631,7 +1631,7 @@ static void update_pvclock_gtod(struct timekeeper *tk)
 	write_seqcount_begin(&vdata->seq);
 
 	/* copy pvclock gtod data */
-	vdata->clock.vclock_mode	= tk->tkr_mono.clock->archdata.vclock_mode;
+	vdata->clock.vclock_mode	= tk->tkr_mono.clock->vdso_clock_mode;
 	vdata->clock.cycle_last		= tk->tkr_mono.cycle_last;
 	vdata->clock.mask		= tk->tkr_mono.mask;
 	vdata->clock.mult		= tk->tkr_mono.mult;
@@ -1639,7 +1639,7 @@ static void update_pvclock_gtod(struct timekeeper *tk)
 	vdata->clock.base_cycles	= tk->tkr_mono.xtime_nsec;
 	vdata->clock.offset		= tk->tkr_mono.base;
 
-	vdata->raw_clock.vclock_mode	= tk->tkr_raw.clock->archdata.vclock_mode;
+	vdata->raw_clock.vclock_mode	= tk->tkr_raw.clock->vdso_clock_mode;
 	vdata->raw_clock.cycle_last	= tk->tkr_raw.cycle_last;
 	vdata->raw_clock.mask		= tk->tkr_raw.mask;
 	vdata->raw_clock.mult		= tk->tkr_raw.mult;
@@ -1840,7 +1840,7 @@ static u64 compute_guest_tsc(struct kvm_vcpu *vcpu, s64 kernel_ns)
 
 static inline int gtod_is_based_on_tsc(int mode)
 {
-	return mode == VCLOCK_TSC || mode == VCLOCK_HVCLOCK;
+	return mode == VDSO_CLOCKMODE_TSC || mode == VDSO_CLOCKMODE_HVCLOCK;
 }
 
 static void kvm_track_tsc_matching(struct kvm_vcpu *vcpu)
@@ -1933,7 +1933,7 @@ static inline bool kvm_check_tsc_unstable(void)
 	 * TSC is marked unstable when we're running on Hyper-V,
 	 * 'TSC page' clocksource is good.
 	 */
-	if (pvclock_gtod_data.clock.vclock_mode == VCLOCK_HVCLOCK)
+	if (pvclock_gtod_data.clock.vclock_mode == VDSO_CLOCKMODE_HVCLOCK)
 		return false;
 #endif
 	return check_tsc_unstable();
@@ -2088,30 +2088,30 @@ static inline u64 vgettsc(struct pvclock_clock *clock, u64 *tsc_timestamp,
 	u64 tsc_pg_val;
 
 	switch (clock->vclock_mode) {
-	case VCLOCK_HVCLOCK:
+	case VDSO_CLOCKMODE_HVCLOCK:
 		tsc_pg_val = hv_read_tsc_page_tsc(hv_get_tsc_page(),
 						  tsc_timestamp);
 		if (tsc_pg_val != U64_MAX) {
 			/* TSC page valid */
-			*mode = VCLOCK_HVCLOCK;
+			*mode = VDSO_CLOCKMODE_HVCLOCK;
 			v = (tsc_pg_val - clock->cycle_last) &
 				clock->mask;
 		} else {
 			/* TSC page invalid */
-			*mode = VCLOCK_NONE;
+			*mode = VDSO_CLOCKMODE_NONE;
 		}
 		break;
-	case VCLOCK_TSC:
-		*mode = VCLOCK_TSC;
+	case VDSO_CLOCKMODE_TSC:
+		*mode = VDSO_CLOCKMODE_TSC;
 		*tsc_timestamp = read_tsc();
 		v = (*tsc_timestamp - clock->cycle_last) &
 			clock->mask;
 		break;
 	default:
-		*mode = VCLOCK_NONE;
+		*mode = VDSO_CLOCKMODE_NONE;
 	}
 
-	if (*mode == VCLOCK_NONE)
+	if (*mode == VDSO_CLOCKMODE_NONE)
 		*tsc_timestamp = v = 0;
 
 	return v * clock->mult;
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 5d1568f..c8897aa 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -147,7 +147,7 @@ static struct notifier_block xen_pvclock_gtod_notifier = {
 
 static int xen_cs_enable(struct clocksource *cs)
 {
-	vclocks_set_used(VCLOCK_PVCLOCK);
+	vclocks_set_used(VDSO_CLOCKMODE_PVCLOCK);
 	return 0;
 }
 
@@ -419,12 +419,13 @@ void xen_restore_time_memory_area(void)
 	ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t);
 
 	/*
-	 * We don't disable VCLOCK_PVCLOCK entirely if it fails to register the
-	 * secondary time info with Xen or if we migrated to a host without the
-	 * necessary flags. On both of these cases what happens is either
-	 * process seeing a zeroed out pvti or seeing no PVCLOCK_TSC_STABLE_BIT
-	 * bit set. Userspace checks the latter and if 0, it discards the data
-	 * in pvti and fallbacks to a system call for a reliable timestamp.
+	 * We don't disable VDSO_CLOCKMODE_PVCLOCK entirely if it fails to
+	 * register the secondary time info with Xen or if we migrated to a
+	 * host without the necessary flags. On both of these cases what
+	 * happens is either process seeing a zeroed out pvti or seeing no
+	 * PVCLOCK_TSC_STABLE_BIT bit set. Userspace checks the latter and
+	 * if 0, it discards the data in pvti and fallbacks to a system
+	 * call for a reliable timestamp.
 	 */
 	if (ret != 0)
 		pr_notice("Cannot restore secondary vcpu_time_info (err %d)",
@@ -450,7 +451,7 @@ static void xen_setup_vsyscall_time_info(void)
 
 	ret = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_time_memory_area, 0, &t);
 	if (ret) {
-		pr_notice("xen: VCLOCK_PVCLOCK not supported (err %d)\n", ret);
+		pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (err %d)\n", ret);
 		free_page((unsigned long)ti);
 		return;
 	}
@@ -467,14 +468,14 @@ static void xen_setup_vsyscall_time_info(void)
 		if (!ret)
 			free_page((unsigned long)ti);
 
-		pr_notice("xen: VCLOCK_PVCLOCK not supported (tsc unstable)\n");
+		pr_notice("xen: VDSO_CLOCKMODE_PVCLOCK not supported (tsc unstable)\n");
 		return;
 	}
 
 	xen_clock = ti;
 	pvclock_set_pvti_cpu0_va(xen_clock);
 
-	xen_clocksource.archdata.vclock_mode = VCLOCK_PVCLOCK;
+	xen_clocksource.vdso_clock_mode = VDSO_CLOCKMODE_PVCLOCK;
 }
 
 static void __init xen_time_init(void)

[patch V2 10/17] mips: vdso: Use generic VDSO clock mode storage

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

Switch to the generic VDSO clock mode storage.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/mips/Kconfig                         |    2 +-
 arch/mips/include/asm/clocksource.h       |   18 +++---------------
 arch/mips/include/asm/vdso/gettimeofday.h |   24 ++++++------------------
 arch/mips/include/asm/vdso/vsyscall.h     |    9 ---------
 arch/mips/kernel/csrc-r4k.c               |    2 +-
 drivers/clocksource/mips-gic-timer.c      |    8 ++++----
 6 files changed, 15 insertions(+), 48 deletions(-)

--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -4,7 +4,6 @@ config MIPS
 	default y
 	select ARCH_32BIT_OFF_T if !64BIT
 	select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_PTE_SPECIAL if !(32BIT && CPU_HAS_RIXI)
@@ -38,6 +37,7 @@ config MIPS
 	select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
+	select GENERIC_VDSO_CLOCK_MODE
 	select GUP_GET_PTE_LOW_HIGH if CPU_MIPS32 && PHYS_ADDR_T_64BIT
 	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_COMPILER_H
--- a/arch/mips/include/asm/clocksource.h
+++ b/arch/mips/include/asm/clocksource.h
@@ -3,23 +3,11 @@
  * Copyright (C) 2015 Imagination Technologies
  * Author: Alex Smith <alex.smith@imgtec.com>
  */
-
 #ifndef __ASM_CLOCKSOURCE_H
 #define __ASM_CLOCKSOURCE_H
 
-#include <linux/types.h>
-
-/* VDSO clocksources. */
-#define VDSO_CLOCK_NONE		0	/* No suitable clocksource. */
-#define VDSO_CLOCK_R4K		1	/* Use the coprocessor 0 count. */
-#define VDSO_CLOCK_GIC		2	/* Use the GIC. */
-
-/**
- * struct arch_clocksource_data - Architecture-specific clocksource information.
- * @vdso_clock_mode: Method the VDSO should use to access the clocksource.
- */
-struct arch_clocksource_data {
-	u8 vdso_clock_mode;
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMDOE_R4K,	\
+	VDSO_CLOCKMODE_GIC
 
 #endif /* __ASM_CLOCKSOURCE_H */
--- a/arch/mips/include/asm/vdso/gettimeofday.h
+++ b/arch/mips/include/asm/vdso/gettimeofday.h
@@ -175,28 +175,16 @@ static __always_inline u64 read_gic_coun
 
 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 {
-#ifdef CONFIG_CLKSRC_MIPS_GIC
-	const struct vdso_data *data = get_vdso_data();
-#endif
-	u64 cycle_now;
-
-	switch (clock_mode) {
 #ifdef CONFIG_CSRC_R4K
-	case VDSO_CLOCK_R4K:
-		cycle_now = read_r4k_count();
-		break;
+	if (clock_mode == VDSO_CLOCKMODE_R4K)
+		return read_r4k_count();
 #endif
 #ifdef CONFIG_CLKSRC_MIPS_GIC
-	case VDSO_CLOCK_GIC:
-		cycle_now = read_gic_count(data);
-		break;
+	if (clock_mode == VDSO_CLOCKMODE_GIC)
+		return read_gic_count(get_vdso_data());
 #endif
-	default:
-		cycle_now = __VDSO_USE_SYSCALL;
-		break;
-	}
-
-	return cycle_now;
+	/* Keep GCC happy */
+	return U64_MAX;
 }
 
 static inline bool mips_vdso_hres_capable(void)
--- a/arch/mips/include/asm/vdso/vsyscall.h
+++ b/arch/mips/include/asm/vdso/vsyscall.h
@@ -19,15 +19,6 @@ struct vdso_data *__mips_get_k_vdso_data
 }
 #define __arch_get_k_vdso_data __mips_get_k_vdso_data
 
-static __always_inline
-int __mips_get_clock_mode(struct timekeeper *tk)
-{
-	u32 clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode;
-
-	return clock_mode;
-}
-#define __arch_get_clock_mode __mips_get_clock_mode
-
 /* The asm-generic header needs to be included after the definitions above */
 #include <asm-generic/vdso/vsyscall.h>
 
--- a/arch/mips/kernel/csrc-r4k.c
+++ b/arch/mips/kernel/csrc-r4k.c
@@ -78,7 +78,7 @@ int __init init_r4k_clocksource(void)
 	 * by the VDSO (HWREna is configured by configure_hwrena()).
 	 */
 	if (cpu_has_mips_r2_r6 && rdhwr_count_usable())
-		clocksource_mips.archdata.vdso_clock_mode = VDSO_CLOCK_R4K;
+		clocksource_mips.vdso_clock_mode = VDSO_CLOCKMODE_R4K;
 
 	clocksource_register_hz(&clocksource_mips, mips_hpt_frequency);
 
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -155,10 +155,10 @@ static u64 gic_hpt_read(struct clocksour
 }
 
 static struct clocksource gic_clocksource = {
-	.name		= "GIC",
-	.read		= gic_hpt_read,
-	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
-	.archdata	= { .vdso_clock_mode = VDSO_CLOCK_GIC },
+	.name			= "GIC",
+	.read			= gic_hpt_read,
+	.flags			= CLOCK_SOURCE_IS_CONTINUOUS,
+	.vdso_clock_mode	= VDSO_CLOCKMODE_GIC,
 };
 
 static int __init __gic_clocksource_init(void)

Re: [patch V2 10/17] mips: vdso: Use generic VDSO clock mode storage

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 306 bytes --]

On 07/02/2020 12:38, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> Switch to the generic VDSO clock mode storage.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> 

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

[...]

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[tip: timers/core] mips: vdso: Use generic VDSO clock mode storage

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     2ad415f5e62c4ad93cdd01e44bc935b991e6b03a
Gitweb:        https://git.kernel.org/tip/2ad415f5e62c4ad93cdd01e44bc935b991e6b03a
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:57 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:24 +01:00

mips: vdso: Use generic VDSO clock mode storage

Switch to the generic VDSO clock mode storage.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.244684017@linutronix.de


---
 arch/mips/Kconfig                         |  2 +-
 arch/mips/include/asm/clocksource.h       | 18 ++---------------
 arch/mips/include/asm/vdso/gettimeofday.h | 24 +++++-----------------
 arch/mips/include/asm/vdso/vsyscall.h     |  9 +--------
 arch/mips/kernel/csrc-r4k.c               |  2 +-
 drivers/clocksource/mips-gic-timer.c      |  8 +++----
 6 files changed, 15 insertions(+), 48 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 797d7f1..23b5c05 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -4,7 +4,6 @@ config MIPS
 	default y
 	select ARCH_32BIT_OFF_T if !64BIT
 	select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_PTE_SPECIAL if !(32BIT && CPU_HAS_RIXI)
@@ -38,6 +37,7 @@ config MIPS
 	select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
+	select GENERIC_VDSO_CLOCK_MODE
 	select GUP_GET_PTE_LOW_HIGH if CPU_MIPS32 && PHYS_ADDR_T_64BIT
 	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_COMPILER_H
diff --git a/arch/mips/include/asm/clocksource.h b/arch/mips/include/asm/clocksource.h
index cab9ae9..738a202 100644
--- a/arch/mips/include/asm/clocksource.h
+++ b/arch/mips/include/asm/clocksource.h
@@ -3,23 +3,11 @@
  * Copyright (C) 2015 Imagination Technologies
  * Author: Alex Smith <alex.smith@imgtec.com>
  */
-
 #ifndef __ASM_CLOCKSOURCE_H
 #define __ASM_CLOCKSOURCE_H
 
-#include <linux/types.h>
-
-/* VDSO clocksources. */
-#define VDSO_CLOCK_NONE		0	/* No suitable clocksource. */
-#define VDSO_CLOCK_R4K		1	/* Use the coprocessor 0 count. */
-#define VDSO_CLOCK_GIC		2	/* Use the GIC. */
-
-/**
- * struct arch_clocksource_data - Architecture-specific clocksource information.
- * @vdso_clock_mode: Method the VDSO should use to access the clocksource.
- */
-struct arch_clocksource_data {
-	u8 vdso_clock_mode;
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMDOE_R4K,	\
+	VDSO_CLOCKMODE_GIC
 
 #endif /* __ASM_CLOCKSOURCE_H */
diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h
index a9f846b..810d225 100644
--- a/arch/mips/include/asm/vdso/gettimeofday.h
+++ b/arch/mips/include/asm/vdso/gettimeofday.h
@@ -175,28 +175,16 @@ static __always_inline u64 read_gic_count(const struct vdso_data *data)
 
 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 {
-#ifdef CONFIG_CLKSRC_MIPS_GIC
-	const struct vdso_data *data = get_vdso_data();
-#endif
-	u64 cycle_now;
-
-	switch (clock_mode) {
 #ifdef CONFIG_CSRC_R4K
-	case VDSO_CLOCK_R4K:
-		cycle_now = read_r4k_count();
-		break;
+	if (clock_mode == VDSO_CLOCKMODE_R4K)
+		return read_r4k_count();
 #endif
 #ifdef CONFIG_CLKSRC_MIPS_GIC
-	case VDSO_CLOCK_GIC:
-		cycle_now = read_gic_count(data);
-		break;
+	if (clock_mode == VDSO_CLOCKMODE_GIC)
+		return read_gic_count(get_vdso_data());
 #endif
-	default:
-		cycle_now = __VDSO_USE_SYSCALL;
-		break;
-	}
-
-	return cycle_now;
+	/* Keep GCC happy */
+	return U64_MAX;
 }
 
 static inline bool mips_vdso_hres_capable(void)
diff --git a/arch/mips/include/asm/vdso/vsyscall.h b/arch/mips/include/asm/vdso/vsyscall.h
index 00d41b9..47168aa 100644
--- a/arch/mips/include/asm/vdso/vsyscall.h
+++ b/arch/mips/include/asm/vdso/vsyscall.h
@@ -19,15 +19,6 @@ struct vdso_data *__mips_get_k_vdso_data(void)
 }
 #define __arch_get_k_vdso_data __mips_get_k_vdso_data
 
-static __always_inline
-int __mips_get_clock_mode(struct timekeeper *tk)
-{
-	u32 clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode;
-
-	return clock_mode;
-}
-#define __arch_get_clock_mode __mips_get_clock_mode
-
 /* The asm-generic header needs to be included after the definitions above */
 #include <asm-generic/vdso/vsyscall.h>
 
diff --git a/arch/mips/kernel/csrc-r4k.c b/arch/mips/kernel/csrc-r4k.c
index eed099f..437dda6 100644
--- a/arch/mips/kernel/csrc-r4k.c
+++ b/arch/mips/kernel/csrc-r4k.c
@@ -78,7 +78,7 @@ int __init init_r4k_clocksource(void)
 	 * by the VDSO (HWREna is configured by configure_hwrena()).
 	 */
 	if (cpu_has_mips_r2_r6 && rdhwr_count_usable())
-		clocksource_mips.archdata.vdso_clock_mode = VDSO_CLOCK_R4K;
+		clocksource_mips.vdso_clock_mode = VDSO_CLOCKMODE_R4K;
 
 	clocksource_register_hz(&clocksource_mips, mips_hpt_frequency);
 
diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index 37671a5..8b5f8ae 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -155,10 +155,10 @@ static u64 gic_hpt_read(struct clocksource *cs)
 }
 
 static struct clocksource gic_clocksource = {
-	.name		= "GIC",
-	.read		= gic_hpt_read,
-	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
-	.archdata	= { .vdso_clock_mode = VDSO_CLOCK_GIC },
+	.name			= "GIC",
+	.read			= gic_hpt_read,
+	.flags			= CLOCK_SOURCE_IS_CONTINUOUS,
+	.vdso_clock_mode	= VDSO_CLOCKMODE_GIC,
 };
 
 static int __init __gic_clocksource_init(void)

[tip: timers/core] mips: vdso: Use generic VDSO clock mode storage

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     e1bdb22ebe5363ed75ddedf836ca9f19e1195337
Gitweb:        https://git.kernel.org/tip/e1bdb22ebe5363ed75ddedf836ca9f19e1195337
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:57 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 20:12:16 +01:00

mips: vdso: Use generic VDSO clock mode storage

Switch to the generic VDSO clock mode storage.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.244684017@linutronix.de



---
 arch/mips/Kconfig                         |  2 +-
 arch/mips/include/asm/clocksource.h       | 18 ++-----------
 arch/mips/include/asm/vdso/gettimeofday.h | 30 +++++++---------------
 arch/mips/include/asm/vdso/vsyscall.h     |  9 +-------
 arch/mips/kernel/csrc-r4k.c               |  2 +-
 drivers/clocksource/mips-gic-timer.c      |  8 +++---
 6 files changed, 19 insertions(+), 50 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 797d7f1..23b5c05 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -4,7 +4,6 @@ config MIPS
 	default y
 	select ARCH_32BIT_OFF_T if !64BIT
 	select ARCH_BINFMT_ELF_STATE if MIPS_FP_SUPPORT
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_FORTIFY_SOURCE
 	select ARCH_HAS_KCOV
 	select ARCH_HAS_PTE_SPECIAL if !(32BIT && CPU_HAS_RIXI)
@@ -38,6 +37,7 @@ config MIPS
 	select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
+	select GENERIC_VDSO_CLOCK_MODE
 	select GUP_GET_PTE_LOW_HIGH if CPU_MIPS32 && PHYS_ADDR_T_64BIT
 	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_COMPILER_H
diff --git a/arch/mips/include/asm/clocksource.h b/arch/mips/include/asm/clocksource.h
index cab9ae9..de659ca 100644
--- a/arch/mips/include/asm/clocksource.h
+++ b/arch/mips/include/asm/clocksource.h
@@ -3,23 +3,11 @@
  * Copyright (C) 2015 Imagination Technologies
  * Author: Alex Smith <alex.smith@imgtec.com>
  */
-
 #ifndef __ASM_CLOCKSOURCE_H
 #define __ASM_CLOCKSOURCE_H
 
-#include <linux/types.h>
-
-/* VDSO clocksources. */
-#define VDSO_CLOCK_NONE		0	/* No suitable clocksource. */
-#define VDSO_CLOCK_R4K		1	/* Use the coprocessor 0 count. */
-#define VDSO_CLOCK_GIC		2	/* Use the GIC. */
-
-/**
- * struct arch_clocksource_data - Architecture-specific clocksource information.
- * @vdso_clock_mode: Method the VDSO should use to access the clocksource.
- */
-struct arch_clocksource_data {
-	u8 vdso_clock_mode;
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_R4K,	\
+	VDSO_CLOCKMODE_GIC
 
 #endif /* __ASM_CLOCKSOURCE_H */
diff --git a/arch/mips/include/asm/vdso/gettimeofday.h b/arch/mips/include/asm/vdso/gettimeofday.h
index a9f846b..88c3de1 100644
--- a/arch/mips/include/asm/vdso/gettimeofday.h
+++ b/arch/mips/include/asm/vdso/gettimeofday.h
@@ -24,8 +24,6 @@
 
 #define VDSO_HAS_CLOCK_GETRES		1
 
-#define __VDSO_USE_SYSCALL		ULLONG_MAX
-
 static __always_inline long gettimeofday_fallback(
 				struct __kernel_old_timeval *_tv,
 				struct timezone *_tz)
@@ -175,28 +173,20 @@ static __always_inline u64 read_gic_count(const struct vdso_data *data)
 
 static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 {
-#ifdef CONFIG_CLKSRC_MIPS_GIC
-	const struct vdso_data *data = get_vdso_data();
-#endif
-	u64 cycle_now;
-
-	switch (clock_mode) {
 #ifdef CONFIG_CSRC_R4K
-	case VDSO_CLOCK_R4K:
-		cycle_now = read_r4k_count();
-		break;
+	if (clock_mode == VDSO_CLOCKMODE_R4K)
+		return read_r4k_count();
 #endif
 #ifdef CONFIG_CLKSRC_MIPS_GIC
-	case VDSO_CLOCK_GIC:
-		cycle_now = read_gic_count(data);
-		break;
+	if (clock_mode == VDSO_CLOCKMODE_GIC)
+		return read_gic_count(get_vdso_data());
 #endif
-	default:
-		cycle_now = __VDSO_USE_SYSCALL;
-		break;
-	}
-
-	return cycle_now;
+	/*
+	 * Core checks mode already. So this raced against a concurrent
+	 * update. Return something. Core will do another round see the
+	 * change and fallback to syscall.
+	 */
+	return 0;
 }
 
 static inline bool mips_vdso_hres_capable(void)
diff --git a/arch/mips/include/asm/vdso/vsyscall.h b/arch/mips/include/asm/vdso/vsyscall.h
index 00d41b9..47168aa 100644
--- a/arch/mips/include/asm/vdso/vsyscall.h
+++ b/arch/mips/include/asm/vdso/vsyscall.h
@@ -19,15 +19,6 @@ struct vdso_data *__mips_get_k_vdso_data(void)
 }
 #define __arch_get_k_vdso_data __mips_get_k_vdso_data
 
-static __always_inline
-int __mips_get_clock_mode(struct timekeeper *tk)
-{
-	u32 clock_mode = tk->tkr_mono.clock->archdata.vdso_clock_mode;
-
-	return clock_mode;
-}
-#define __arch_get_clock_mode __mips_get_clock_mode
-
 /* The asm-generic header needs to be included after the definitions above */
 #include <asm-generic/vdso/vsyscall.h>
 
diff --git a/arch/mips/kernel/csrc-r4k.c b/arch/mips/kernel/csrc-r4k.c
index eed099f..437dda6 100644
--- a/arch/mips/kernel/csrc-r4k.c
+++ b/arch/mips/kernel/csrc-r4k.c
@@ -78,7 +78,7 @@ int __init init_r4k_clocksource(void)
 	 * by the VDSO (HWREna is configured by configure_hwrena()).
 	 */
 	if (cpu_has_mips_r2_r6 && rdhwr_count_usable())
-		clocksource_mips.archdata.vdso_clock_mode = VDSO_CLOCK_R4K;
+		clocksource_mips.vdso_clock_mode = VDSO_CLOCKMODE_R4K;
 
 	clocksource_register_hz(&clocksource_mips, mips_hpt_frequency);
 
diff --git a/drivers/clocksource/mips-gic-timer.c b/drivers/clocksource/mips-gic-timer.c
index 37671a5..8b5f8ae 100644
--- a/drivers/clocksource/mips-gic-timer.c
+++ b/drivers/clocksource/mips-gic-timer.c
@@ -155,10 +155,10 @@ static u64 gic_hpt_read(struct clocksource *cs)
 }
 
 static struct clocksource gic_clocksource = {
-	.name		= "GIC",
-	.read		= gic_hpt_read,
-	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
-	.archdata	= { .vdso_clock_mode = VDSO_CLOCK_GIC },
+	.name			= "GIC",
+	.read			= gic_hpt_read,
+	.flags			= CLOCK_SOURCE_IS_CONTINUOUS,
+	.vdso_clock_mode	= VDSO_CLOCKMODE_GIC,
 };
 
 static int __init __gic_clocksource_init(void)

[patch V2 11/17] ARM/arm64: vdso: Use common vdso clock mode storage

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
happen in one go as they share the clocksource driver.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/arm/Kconfig                       |    1 -
 arch/arm/include/asm/clocksource.h     |    5 ++---
 arch/arm/include/asm/vdso/vsyscall.h   |   21 ---------------------
 arch/arm/mm/Kconfig                    |    1 +
 arch/arm64/Kconfig                     |    2 +-
 arch/arm64/include/asm/clocksource.h   |    5 ++---
 arch/arm64/include/asm/vdso/vsyscall.h |    9 ---------
 drivers/clocksource/arm_arch_timer.c   |    8 ++++----
 8 files changed, 10 insertions(+), 42 deletions(-)

--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -3,7 +3,6 @@ config ARM
 	bool
 	default y
 	select ARCH_32BIT_OFF_T
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
--- a/arch/arm/include/asm/clocksource.h
+++ b/arch/arm/include/asm/clocksource.h
@@ -1,8 +1,7 @@
 #ifndef _ASM_CLOCKSOURCE_H
 #define _ASM_CLOCKSOURCE_H
 
-struct arch_clocksource_data {
-	bool vdso_direct;	/* Usable for direct VDSO access? */
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_ARCHTIMER
 
 #endif
--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -11,18 +11,6 @@
 extern struct vdso_data *vdso_data;
 extern bool cntvct_ok;
 
-static __always_inline
-bool tk_is_cntvct(const struct timekeeper *tk)
-{
-	if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
-		return false;
-
-	if (!tk->tkr_mono.clock->archdata.vdso_direct)
-		return false;
-
-	return true;
-}
-
 /*
  * Update the vDSO data page to keep in sync with kernel timekeeping.
  */
@@ -41,15 +29,6 @@ bool __arm_update_vdso_data(void)
 #define __arch_update_vdso_data __arm_update_vdso_data
 
 static __always_inline
-int __arm_get_clock_mode(struct timekeeper *tk)
-{
-	u32 __tk_is_cntvct = tk_is_cntvct(tk);
-
-	return __tk_is_cntvct;
-}
-#define __arch_get_clock_mode __arm_get_clock_mode
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -900,6 +900,7 @@ config VDSO
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_32
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_VDSO_CLOCK_MODE
 	help
 	  Place in the process address space an ELF shared object
 	  providing fast implementations of gettimeofday and
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -9,7 +9,6 @@ config ARM64
 	select ACPI_MCFG if (ACPI && PCI)
 	select ACPI_SPCR_TABLE if ACPI
 	select ACPI_PPTT if ACPI
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_PREP_COHERENT
@@ -110,6 +109,7 @@ config ARM64
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_VDSO_CLOCK_MODE
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_PCI
--- a/arch/arm64/include/asm/clocksource.h
+++ b/arch/arm64/include/asm/clocksource.h
@@ -2,8 +2,7 @@
 #ifndef _ASM_CLOCKSOURCE_H
 #define _ASM_CLOCKSOURCE_H
 
-struct arch_clocksource_data {
-	bool vdso_direct;	/* Usable for direct VDSO access? */
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_ARCHTIMER
 
 #endif
--- a/arch/arm64/include/asm/vdso/vsyscall.h
+++ b/arch/arm64/include/asm/vdso/vsyscall.h
@@ -22,15 +22,6 @@ struct vdso_data *__arm64_get_k_vdso_dat
 #define __arch_get_k_vdso_data __arm64_get_k_vdso_data
 
 static __always_inline
-int __arm64_get_clock_mode(struct timekeeper *tk)
-{
-	u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct;
-
-	return use_syscall;
-}
-#define __arch_get_clock_mode __arm64_get_clock_mode
-
-static __always_inline
 void __arm64_update_vsyscall(struct vdso_data *vdata, struct timekeeper *tk)
 {
 	vdata[CS_HRES_COARSE].mask	= VDSO_PRECISION_MASK;
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -69,7 +69,7 @@ static enum arch_timer_ppi_nr arch_timer
 static bool arch_timer_c3stop;
 static bool arch_timer_mem_use_virtual;
 static bool arch_counter_suspend_stop;
-static bool vdso_default = true;
+static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
 
 static cpumask_t evtstrm_available = CPU_MASK_NONE;
 static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
@@ -560,8 +560,8 @@ void arch_timer_enable_workaround(const
 	 * change both the default value and the vdso itself.
 	 */
 	if (wa->read_cntvct_el0) {
-		clocksource_counter.archdata.vdso_direct = false;
-		vdso_default = false;
+		clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_NONE;
+		vdso_default = VDSO_CLOCKMODE_NONE;
 	}
 }
 
@@ -979,7 +979,7 @@ static void __init arch_counter_register
 		}
 
 		arch_timer_read_counter = rd;
-		clocksource_counter.archdata.vdso_direct = vdso_default;
+		clocksource_counter.vdso_clock_mode = vdso_default;
 	} else {
 		arch_timer_read_counter = arch_counter_get_cntvct_mem;
 	}

Re: [patch V2 11/17] ARM/arm64: vdso: Use common vdso clock mode storage

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 446 bytes --]

On 07/02/2020 12:38, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
> happen in one go as they share the clocksource driver.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>


Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

[...]
-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[tip: timers/core] ARM/arm64: vdso: Use common vdso clock mode storage

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     db26b4e9ff74027e16ee47be2da7b86b7e070352
Gitweb:        https://git.kernel.org/tip/db26b4e9ff74027e16ee47be2da7b86b7e070352
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:58 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:25 +01:00

ARM/arm64: vdso: Use common vdso clock mode storage

Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
happen in one go as they share the clocksource driver.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de


---
 arch/arm/Kconfig                       |  1 -
 arch/arm/include/asm/clocksource.h     |  5 ++---
 arch/arm/include/asm/vdso/vsyscall.h   | 21 ---------------------
 arch/arm/mm/Kconfig                    |  1 +
 arch/arm64/Kconfig                     |  2 +-
 arch/arm64/include/asm/clocksource.h   |  5 ++---
 arch/arm64/include/asm/vdso/vsyscall.h |  9 ---------
 drivers/clocksource/arm_arch_timer.c   |  8 ++++----
 8 files changed, 10 insertions(+), 42 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 97864aa..03bbfc3 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -3,7 +3,6 @@ config ARM
 	bool
 	default y
 	select ARCH_32BIT_OFF_T
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
diff --git a/arch/arm/include/asm/clocksource.h b/arch/arm/include/asm/clocksource.h
index 0b350a7..73beb7f 100644
--- a/arch/arm/include/asm/clocksource.h
+++ b/arch/arm/include/asm/clocksource.h
@@ -1,8 +1,7 @@
 #ifndef _ASM_CLOCKSOURCE_H
 #define _ASM_CLOCKSOURCE_H
 
-struct arch_clocksource_data {
-	bool vdso_direct;	/* Usable for direct VDSO access? */
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_ARCHTIMER
 
 #endif
diff --git a/arch/arm/include/asm/vdso/vsyscall.h b/arch/arm/include/asm/vdso/vsyscall.h
index 85a7e58..002f9ed 100644
--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -11,18 +11,6 @@
 extern struct vdso_data *vdso_data;
 extern bool cntvct_ok;
 
-static __always_inline
-bool tk_is_cntvct(const struct timekeeper *tk)
-{
-	if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
-		return false;
-
-	if (!tk->tkr_mono.clock->archdata.vdso_direct)
-		return false;
-
-	return true;
-}
-
 /*
  * Update the vDSO data page to keep in sync with kernel timekeeping.
  */
@@ -41,15 +29,6 @@ bool __arm_update_vdso_data(void)
 #define __arch_update_vdso_data __arm_update_vdso_data
 
 static __always_inline
-int __arm_get_clock_mode(struct timekeeper *tk)
-{
-	u32 __tk_is_cntvct = tk_is_cntvct(tk);
-
-	return __tk_is_cntvct;
-}
-#define __arch_get_clock_mode __arm_get_clock_mode
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 65e4482..865e888 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -900,6 +900,7 @@ config VDSO
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_32
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_VDSO_CLOCK_MODE
 	help
 	  Place in the process address space an ELF shared object
 	  providing fast implementations of gettimeofday and
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 0b30e88..7809d49 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -9,7 +9,6 @@ config ARM64
 	select ACPI_MCFG if (ACPI && PCI)
 	select ACPI_SPCR_TABLE if ACPI
 	select ACPI_PPTT if ACPI
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_PREP_COHERENT
@@ -111,6 +110,7 @@ config ARM64
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_VDSO_CLOCK_MODE
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_PCI
diff --git a/arch/arm64/include/asm/clocksource.h b/arch/arm64/include/asm/clocksource.h
index 0ece64a..eb82e9d 100644
--- a/arch/arm64/include/asm/clocksource.h
+++ b/arch/arm64/include/asm/clocksource.h
@@ -2,8 +2,7 @@
 #ifndef _ASM_CLOCKSOURCE_H
 #define _ASM_CLOCKSOURCE_H
 
-struct arch_clocksource_data {
-	bool vdso_direct;	/* Usable for direct VDSO access? */
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_ARCHTIMER
 
 #endif
diff --git a/arch/arm64/include/asm/vdso/vsyscall.h b/arch/arm64/include/asm/vdso/vsyscall.h
index 0c20a7c..f94b145 100644
--- a/arch/arm64/include/asm/vdso/vsyscall.h
+++ b/arch/arm64/include/asm/vdso/vsyscall.h
@@ -22,15 +22,6 @@ struct vdso_data *__arm64_get_k_vdso_data(void)
 #define __arch_get_k_vdso_data __arm64_get_k_vdso_data
 
 static __always_inline
-int __arm64_get_clock_mode(struct timekeeper *tk)
-{
-	u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct;
-
-	return use_syscall;
-}
-#define __arch_get_clock_mode __arm64_get_clock_mode
-
-static __always_inline
 void __arm64_update_vsyscall(struct vdso_data *vdata, struct timekeeper *tk)
 {
 	vdata[CS_HRES_COARSE].mask	= VDSO_PRECISION_MASK;
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 9a5464c..ee2420d 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -69,7 +69,7 @@ static enum arch_timer_ppi_nr arch_timer_uses_ppi = ARCH_TIMER_VIRT_PPI;
 static bool arch_timer_c3stop;
 static bool arch_timer_mem_use_virtual;
 static bool arch_counter_suspend_stop;
-static bool vdso_default = true;
+static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
 
 static cpumask_t evtstrm_available = CPU_MASK_NONE;
 static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
@@ -560,8 +560,8 @@ void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa
 	 * change both the default value and the vdso itself.
 	 */
 	if (wa->read_cntvct_el0) {
-		clocksource_counter.archdata.vdso_direct = false;
-		vdso_default = false;
+		clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_NONE;
+		vdso_default = VDSO_CLOCKMODE_NONE;
 	}
 }
 
@@ -979,7 +979,7 @@ static void __init arch_counter_register(unsigned type)
 		}
 
 		arch_timer_read_counter = rd;
-		clocksource_counter.archdata.vdso_direct = vdso_default;
+		clocksource_counter.vdso_clock_mode = vdso_default;
 	} else {
 		arch_timer_read_counter = arch_counter_get_cntvct_mem;
 	}

[tip: timers/core] ARM/arm64: vdso: Use common vdso clock mode storage

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     5e3c6a312a0946d2d83e32359612cbb925a8bed0
Gitweb:        https://git.kernel.org/tip/5e3c6a312a0946d2d83e32359612cbb925a8bed0
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:58 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 20:12:16 +01:00

ARM/arm64: vdso: Use common vdso clock mode storage

Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
happen in one go as they share the clocksource driver.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.363235229@linutronix.de



---
 arch/arm/Kconfig                                  |  1 +-
 arch/arm/include/asm/clocksource.h                |  5 +--
 arch/arm/include/asm/vdso/gettimeofday.h          | 12 ++++++--
 arch/arm/include/asm/vdso/vsyscall.h              | 21 +--------------
 arch/arm/mm/Kconfig                               |  1 +-
 arch/arm64/Kconfig                                |  2 +-
 arch/arm64/include/asm/clocksource.h              |  5 +--
 arch/arm64/include/asm/vdso/compat_gettimeofday.h | 11 +++----
 arch/arm64/include/asm/vdso/gettimeofday.h        | 11 +++----
 arch/arm64/include/asm/vdso/vsyscall.h            |  9 +------
 drivers/clocksource/arm_arch_timer.c              |  8 ++---
 11 files changed, 29 insertions(+), 57 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 97864aa..03bbfc3 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -3,7 +3,6 @@ config ARM
 	bool
 	default y
 	select ARCH_32BIT_OFF_T
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_BINFMT_FLAT
 	select ARCH_HAS_DEBUG_VIRTUAL if MMU
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
diff --git a/arch/arm/include/asm/clocksource.h b/arch/arm/include/asm/clocksource.h
index 0b350a7..73beb7f 100644
--- a/arch/arm/include/asm/clocksource.h
+++ b/arch/arm/include/asm/clocksource.h
@@ -1,8 +1,7 @@
 #ifndef _ASM_CLOCKSOURCE_H
 #define _ASM_CLOCKSOURCE_H
 
-struct arch_clocksource_data {
-	bool vdso_direct;	/* Usable for direct VDSO access? */
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_ARCHTIMER
 
 #endif
diff --git a/arch/arm/include/asm/vdso/gettimeofday.h b/arch/arm/include/asm/vdso/gettimeofday.h
index f4757d3..07d791c 100644
--- a/arch/arm/include/asm/vdso/gettimeofday.h
+++ b/arch/arm/include/asm/vdso/gettimeofday.h
@@ -117,15 +117,21 @@ static __always_inline u64 __arch_get_hw_counter(int clock_mode)
 #ifdef CONFIG_ARM_ARCH_TIMER
 	u64 cycle_now;
 
-	if (!clock_mode)
-		return -EINVAL;
+	/*
+	 * Core checks for mode already, so this raced against a concurrent
+	 * update. Return something. Core will do another round and then
+	 * see the mode change and fallback to the syscall.
+	 */
+	if (clock_mode == VDSO_CLOCKMODE_NONE)
+		return 0;
 
 	isb();
 	cycle_now = read_sysreg(CNTVCT);
 
 	return cycle_now;
 #else
-	return -EINVAL; /* use fallback */
+	/* Make GCC happy. This is compiled out anyway */
+	return 0;
 #endif
 }
 
diff --git a/arch/arm/include/asm/vdso/vsyscall.h b/arch/arm/include/asm/vdso/vsyscall.h
index 85a7e58..002f9ed 100644
--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -11,18 +11,6 @@
 extern struct vdso_data *vdso_data;
 extern bool cntvct_ok;
 
-static __always_inline
-bool tk_is_cntvct(const struct timekeeper *tk)
-{
-	if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER))
-		return false;
-
-	if (!tk->tkr_mono.clock->archdata.vdso_direct)
-		return false;
-
-	return true;
-}
-
 /*
  * Update the vDSO data page to keep in sync with kernel timekeeping.
  */
@@ -41,15 +29,6 @@ bool __arm_update_vdso_data(void)
 #define __arch_update_vdso_data __arm_update_vdso_data
 
 static __always_inline
-int __arm_get_clock_mode(struct timekeeper *tk)
-{
-	u32 __tk_is_cntvct = tk_is_cntvct(tk);
-
-	return __tk_is_cntvct;
-}
-#define __arch_get_clock_mode __arm_get_clock_mode
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 65e4482..865e888 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -900,6 +900,7 @@ config VDSO
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_32
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_VDSO_CLOCK_MODE
 	help
 	  Place in the process address space an ELF shared object
 	  providing fast implementations of gettimeofday and
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 0b30e88..7809d49 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -9,7 +9,6 @@ config ARM64
 	select ACPI_MCFG if (ACPI && PCI)
 	select ACPI_SPCR_TABLE if ACPI
 	select ACPI_PPTT if ACPI
-	select ARCH_CLOCKSOURCE_DATA
 	select ARCH_HAS_DEBUG_VIRTUAL
 	select ARCH_HAS_DEVMEM_IS_ALLOWED
 	select ARCH_HAS_DMA_PREP_COHERENT
@@ -111,6 +110,7 @@ config ARM64
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
+	select GENERIC_VDSO_CLOCK_MODE
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_PCI
diff --git a/arch/arm64/include/asm/clocksource.h b/arch/arm64/include/asm/clocksource.h
index 0ece64a..eb82e9d 100644
--- a/arch/arm64/include/asm/clocksource.h
+++ b/arch/arm64/include/asm/clocksource.h
@@ -2,8 +2,7 @@
 #ifndef _ASM_CLOCKSOURCE_H
 #define _ASM_CLOCKSOURCE_H
 
-struct arch_clocksource_data {
-	bool vdso_direct;	/* Usable for direct VDSO access? */
-};
+#define VDSO_ARCH_CLOCKMODES	\
+	VDSO_CLOCKMODE_ARCHTIMER
 
 #endif
diff --git a/arch/arm64/include/asm/vdso/compat_gettimeofday.h b/arch/arm64/include/asm/vdso/compat_gettimeofday.h
index 537b1e6..81b0c39 100644
--- a/arch/arm64/include/asm/vdso/compat_gettimeofday.h
+++ b/arch/arm64/include/asm/vdso/compat_gettimeofday.h
@@ -12,8 +12,6 @@
 
 #include <asm/vdso/compat_barrier.h>
 
-#define __VDSO_USE_SYSCALL		ULLONG_MAX
-
 #define VDSO_HAS_CLOCK_GETRES		1
 
 #define BUILD_VDSO32			1
@@ -117,11 +115,12 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 	u64 res;
 
 	/*
-	 * clock_mode == 0 implies that vDSO are enabled otherwise
-	 * fallback on syscall.
+	 * Core checks for mode already, so this raced against a concurrent
+	 * update. Return something. Core will do another round and then
+	 * see the mode change and fallback to the syscall.
 	 */
-	if (clock_mode)
-		return __VDSO_USE_SYSCALL;
+	if (clock_mode == VDSO_CLOCKMODE_NONE)
+		return 0;
 
 	/*
 	 * This isb() is required to prevent that the counter value
diff --git a/arch/arm64/include/asm/vdso/gettimeofday.h b/arch/arm64/include/asm/vdso/gettimeofday.h
index b08f476..5a53443 100644
--- a/arch/arm64/include/asm/vdso/gettimeofday.h
+++ b/arch/arm64/include/asm/vdso/gettimeofday.h
@@ -10,8 +10,6 @@
 #include <asm/unistd.h>
 #include <uapi/linux/time.h>
 
-#define __VDSO_USE_SYSCALL		ULLONG_MAX
-
 #define VDSO_HAS_CLOCK_GETRES		1
 
 static __always_inline
@@ -71,11 +69,12 @@ static __always_inline u64 __arch_get_hw_counter(s32 clock_mode)
 	u64 res;
 
 	/*
-	 * clock_mode == 0 implies that vDSO are enabled otherwise
-	 * fallback on syscall.
+	 * Core checks for mode already, so this raced against a concurrent
+	 * update. Return something. Core will do another round and then
+	 * see the mode change and fallback to the syscall.
 	 */
-	if (clock_mode)
-		return __VDSO_USE_SYSCALL;
+	if (clock_mode == VDSO_CLOCKMODE_NONE)
+		return 0;
 
 	/*
 	 * This isb() is required to prevent that the counter value
diff --git a/arch/arm64/include/asm/vdso/vsyscall.h b/arch/arm64/include/asm/vdso/vsyscall.h
index 0c20a7c..f94b145 100644
--- a/arch/arm64/include/asm/vdso/vsyscall.h
+++ b/arch/arm64/include/asm/vdso/vsyscall.h
@@ -22,15 +22,6 @@ struct vdso_data *__arm64_get_k_vdso_data(void)
 #define __arch_get_k_vdso_data __arm64_get_k_vdso_data
 
 static __always_inline
-int __arm64_get_clock_mode(struct timekeeper *tk)
-{
-	u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct;
-
-	return use_syscall;
-}
-#define __arch_get_clock_mode __arm64_get_clock_mode
-
-static __always_inline
 void __arm64_update_vsyscall(struct vdso_data *vdata, struct timekeeper *tk)
 {
 	vdata[CS_HRES_COARSE].mask	= VDSO_PRECISION_MASK;
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c
index 9a5464c..ee2420d 100644
--- a/drivers/clocksource/arm_arch_timer.c
+++ b/drivers/clocksource/arm_arch_timer.c
@@ -69,7 +69,7 @@ static enum arch_timer_ppi_nr arch_timer_uses_ppi = ARCH_TIMER_VIRT_PPI;
 static bool arch_timer_c3stop;
 static bool arch_timer_mem_use_virtual;
 static bool arch_counter_suspend_stop;
-static bool vdso_default = true;
+static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
 
 static cpumask_t evtstrm_available = CPU_MASK_NONE;
 static bool evtstrm_enable = IS_ENABLED(CONFIG_ARM_ARCH_TIMER_EVTSTREAM);
@@ -560,8 +560,8 @@ void arch_timer_enable_workaround(const struct arch_timer_erratum_workaround *wa
 	 * change both the default value and the vdso itself.
 	 */
 	if (wa->read_cntvct_el0) {
-		clocksource_counter.archdata.vdso_direct = false;
-		vdso_default = false;
+		clocksource_counter.vdso_clock_mode = VDSO_CLOCKMODE_NONE;
+		vdso_default = VDSO_CLOCKMODE_NONE;
 	}
 }
 
@@ -979,7 +979,7 @@ static void __init arch_counter_register(unsigned type)
 		}
 
 		arch_timer_read_counter = rd;
-		clocksource_counter.archdata.vdso_direct = vdso_default;
+		clocksource_counter.vdso_clock_mode = vdso_default;
 	} else {
 		arch_timer_read_counter = arch_counter_get_cntvct_mem;
 	}

Re: [patch V2 11/17] ARM/arm64: vdso: Use common vdso clock mode storage

[Marek Szyprowski]

Hi Thomas,

On 07.02.2020 13:38, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
>
> Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
> happen in one go as they share the clocksource driver.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

This patch landed in today's linux-next (next-20200221) as commit 
5e3c6a312a09. It breaks ARM 32bit build without VDSO enabled in .config:

$ make ARCH=arm multi_v7_defconfig

$ ./scripts/config -e ARM_LPAE -e VIRTUALIZATION -e KVM -d VDSO

$ make ARCH=arm olddefconfig

$ make

...

drivers/clocksource/arm_arch_timer.c:73:44: error: 
‘VDSO_CLOCKMODE_ARCHTIMER’ undeclared here (not in a function)
  static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
                                             ^
scripts/Makefile.build:267: recipe for target 
'drivers/clocksource/arm_arch_timer.o' failed
make[2]: *** [drivers/clocksource/arm_arch_timer.o] Error 1
make[2]: *** Waiting for unfinished jobs....
scripts/Makefile.build:505: recipe for target 'drivers/clocksource' failed
make[1]: *** [drivers/clocksource] Error 2
make[1]: *** Waiting for unfinished jobs....
Makefile:1683: recipe for target 'drivers' failed
make: *** [drivers] Error 2

> ...

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland

Re: [patch V2 11/17] ARM/arm64: vdso: Use common vdso clock mode storage

[Marek Szyprowski]

Hi Thomas,

On 07.02.2020 13:38, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
>
> Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
> happen in one go as they share the clocksource driver.
>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

This patch landed in today's linux-next (next-20200221) as commit 
5e3c6a312a09. It breaks ARM 32bit build without VDSO enabled in .config:

$ make ARCH=arm multi_v7_defconfig

$ ./scripts/config -e ARM_LPAE -e VIRTUALIZATION -e KVM -d VDSO

$ make ARCH=arm olddefconfig

$ make

...

drivers/clocksource/arm_arch_timer.c:73:44: error: 
‘VDSO_CLOCKMODE_ARCHTIMER’ undeclared here (not in a function)
  static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
                                             ^
scripts/Makefile.build:267: recipe for target 
'drivers/clocksource/arm_arch_timer.o' failed
make[2]: *** [drivers/clocksource/arm_arch_timer.o] Error 1
make[2]: *** Waiting for unfinished jobs....
scripts/Makefile.build:505: recipe for target 'drivers/clocksource' failed
make[1]: *** [drivers/clocksource] Error 2
make[1]: *** Waiting for unfinished jobs....
Makefile:1683: recipe for target 'drivers' failed
make: *** [drivers] Error 2

> ...

Best regards
-- 
Marek Szyprowski, PhD
Samsung R&D Institute Poland


_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [patch V2 11/17] ARM/arm64: vdso: Use common vdso clock mode storage

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 1800 bytes --]

Hi Marek,

On 21/02/2020 11:56, Marek Szyprowski wrote:
> Hi Thomas,
> 
> On 07.02.2020 13:38, Thomas Gleixner wrote:
>> From: Thomas Gleixner <tglx@linutronix.de>
>>
>> Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
>> happen in one go as they share the clocksource driver.
>>
>> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
>> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> 
> This patch landed in today's linux-next (next-20200221) as commit 
> 5e3c6a312a09. It breaks ARM 32bit build without VDSO enabled in .config:
> 
> $ make ARCH=arm multi_v7_defconfig
> 
> $ ./scripts/config -e ARM_LPAE -e VIRTUALIZATION -e KVM -d VDSO
> 
> $ make ARCH=arm olddefconfig
> 
> $ make
> 
> ...
> 
> drivers/clocksource/arm_arch_timer.c:73:44: error: 
> ‘VDSO_CLOCKMODE_ARCHTIMER’ undeclared here (not in a function)
>   static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
>                                              ^
> scripts/Makefile.build:267: recipe for target 
> 'drivers/clocksource/arm_arch_timer.o' failed
> make[2]: *** [drivers/clocksource/arm_arch_timer.o] Error 1
> make[2]: *** Waiting for unfinished jobs....
> scripts/Makefile.build:505: recipe for target 'drivers/clocksource' failed
> make[1]: *** [drivers/clocksource] Error 2
> make[1]: *** Waiting for unfinished jobs....
> Makefile:1683: recipe for target 'drivers' failed
> make: *** [drivers] Error 2
> 
>> ...
> 
> Best regards
> 

I think I have a fix for your problem, could you please try it [1]?

[1]  https://lore.kernel.org/lkml/20200221130355.21373-1-vincenzo.frascino@arm.com/
-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

Re: [patch V2 11/17] ARM/arm64: vdso: Use common vdso clock mode storage

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 1800 bytes --]

Hi Marek,

On 21/02/2020 11:56, Marek Szyprowski wrote:
> Hi Thomas,
> 
> On 07.02.2020 13:38, Thomas Gleixner wrote:
>> From: Thomas Gleixner <tglx@linutronix.de>
>>
>> Convert ARM/ARM64 to the generic VDSO clock mode storage. This needs to
>> happen in one go as they share the clocksource driver.
>>
>> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
>> Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
>> Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
> 
> This patch landed in today's linux-next (next-20200221) as commit 
> 5e3c6a312a09. It breaks ARM 32bit build without VDSO enabled in .config:
> 
> $ make ARCH=arm multi_v7_defconfig
> 
> $ ./scripts/config -e ARM_LPAE -e VIRTUALIZATION -e KVM -d VDSO
> 
> $ make ARCH=arm olddefconfig
> 
> $ make
> 
> ...
> 
> drivers/clocksource/arm_arch_timer.c:73:44: error: 
> ‘VDSO_CLOCKMODE_ARCHTIMER’ undeclared here (not in a function)
>   static enum vdso_clock_mode vdso_default = VDSO_CLOCKMODE_ARCHTIMER;
>                                              ^
> scripts/Makefile.build:267: recipe for target 
> 'drivers/clocksource/arm_arch_timer.o' failed
> make[2]: *** [drivers/clocksource/arm_arch_timer.o] Error 1
> make[2]: *** Waiting for unfinished jobs....
> scripts/Makefile.build:505: recipe for target 'drivers/clocksource' failed
> make[1]: *** [drivers/clocksource] Error 2
> make[1]: *** Waiting for unfinished jobs....
> Makefile:1683: recipe for target 'drivers' failed
> make: *** [drivers] Error 2
> 
>> ...
> 
> Best regards
> 

I think I have a fix for your problem, could you please try it [1]?

[1]  https://lore.kernel.org/lkml/20200221130355.21373-1-vincenzo.frascino@arm.com/
-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[-- Attachment #3: Type: text/plain, Size: 176 bytes --]

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

Re: [patch V2 11/17] ARM/arm64: vdso: Use common vdso clock mode storage

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 571 bytes --]

Hi Marek,

On 21/02/2020 11:56, Marek Szyprowski wrote:
[...]

> 
> This patch landed in today's linux-next (next-20200221) as commit 
> 5e3c6a312a09. It breaks ARM 32bit build without VDSO enabled in .config:
> 
> $ make ARCH=arm multi_v7_defconfig
> 
> $ ./scripts/config -e ARM_LPAE -e VIRTUALIZATION -e KVM -d VDSO
> 
> $ make ARCH=arm olddefconfig
> 
> $ make
> 
> ...
> 

[...]
I have a new version [1]. Could you please test it?

[1] https://lore.kernel.org/lkml/20200221181849.40351-1-vincenzo.frascino@arm.com/

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

Re: [patch V2 11/17] ARM/arm64: vdso: Use common vdso clock mode storage

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 571 bytes --]

Hi Marek,

On 21/02/2020 11:56, Marek Szyprowski wrote:
[...]

> 
> This patch landed in today's linux-next (next-20200221) as commit 
> 5e3c6a312a09. It breaks ARM 32bit build without VDSO enabled in .config:
> 
> $ make ARCH=arm multi_v7_defconfig
> 
> $ ./scripts/config -e ARM_LPAE -e VIRTUALIZATION -e KVM -d VDSO
> 
> $ make ARCH=arm olddefconfig
> 
> $ make
> 
> ...
> 

[...]
I have a new version [1]. Could you please test it?

[1] https://lore.kernel.org/lkml/20200221181849.40351-1-vincenzo.frascino@arm.com/

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[-- Attachment #3: Type: text/plain, Size: 176 bytes --]

_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[patch V2 12/17] lib/vdso: Cleanup clock mode storage leftovers

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

Now that all architectures are converted to use the generic storage the
helpers and conditionals can be removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 arch/arm/mm/Kconfig                 |    1 -
 arch/arm64/Kconfig                  |    1 -
 arch/mips/Kconfig                   |    1 -
 arch/x86/Kconfig                    |    1 -
 include/asm-generic/vdso/vsyscall.h |    7 -------
 include/linux/clocksource.h         |    4 ++--
 kernel/time/vsyscall.c              |    4 ----
 lib/vdso/Kconfig                    |    3 ---
 lib/vdso/gettimeofday.c             |   17 +++++------------
 9 files changed, 7 insertions(+), 32 deletions(-)

--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -900,7 +900,6 @@ config VDSO
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_32
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_CLOCK_MODE
 	help
 	  Place in the process address space an ELF shared object
 	  providing fast implementations of gettimeofday and
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -109,7 +109,6 @@ config ARM64
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_CLOCK_MODE
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_PCI
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -35,7 +35,6 @@ config MIPS
 	select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
-	select GENERIC_VDSO_CLOCK_MODE
 	select GUP_GET_PTE_LOW_HIGH if CPU_MIPS32 && PHYS_ADDR_T_64BIT
 	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_COMPILER_H
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -124,7 +124,6 @@ config X86
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_CLOCK_MODE
 	select GENERIC_VDSO_TIME_NS
 	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
 	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
--- a/include/asm-generic/vdso/vsyscall.h
+++ b/include/asm-generic/vdso/vsyscall.h
@@ -18,13 +18,6 @@ static __always_inline bool __arch_updat
 }
 #endif /* __arch_update_vdso_data */
 
-#ifndef __arch_get_clock_mode
-static __always_inline int __arch_get_clock_mode(struct timekeeper *tk)
-{
-	return 0;
-}
-#endif /* __arch_get_clock_mode */
-
 #ifndef __arch_update_vsyscall
 static __always_inline void __arch_update_vsyscall(struct vdso_data *vdata,
 						   struct timekeeper *tk)
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -24,13 +24,13 @@ struct clocksource;
 struct module;
 
 #if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \
-    defined(CONFIG_GENERIC_VDSO_CLOCK_MODE)
+    defined(CONFIG_GENERIC_GETTIMEOFDAY)
 #include <asm/clocksource.h>
 #endif
 
 enum vdso_clock_mode {
 	VDSO_CLOCKMODE_NONE,
-#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+#ifdef CONFIG_GENERIC_GETTIMEOFDAY
 	VDSO_ARCH_CLOCKMODES,
 #endif
 	VDSO_CLOCKMODE_MAX,
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -77,11 +77,7 @@ void update_vsyscall(struct timekeeper *
 	/* copy vsyscall data */
 	vdso_write_begin(vdata);
 
-#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
 	clock_mode = tk->tkr_mono.clock->vdso_clock_mode;
-#else
-	clock_mode = __arch_get_clock_mode(tk);
-#endif
 	vdata[CS_HRES_COARSE].clock_mode	= clock_mode;
 	vdata[CS_RAW].clock_mode		= clock_mode;
 
--- a/lib/vdso/Kconfig
+++ b/lib/vdso/Kconfig
@@ -30,7 +30,4 @@ 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
@@ -65,16 +65,13 @@ 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)
+
+		if (unlikely(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 (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    unlikely((s64)cycles < 0))
-			return -1;
-
 		ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
 		ns >>= vd->shift;
 		sec = vdso_ts->sec;
@@ -137,16 +134,12 @@ static __always_inline int do_hres(const
 		}
 		smp_rmb();
 
-		if (IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    vd->clock_mode == VDSO_CLOCKMODE_NONE)
+		if (unlikely(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 (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    unlikely((s64)cycles < 0))
-			return -1;
-
 		ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
 		ns >>= vd->shift;
 		sec = vdso_ts->sec;

Re: [patch V2 12/17] lib/vdso: Cleanup clock mode storage leftovers

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 431 bytes --]

On 07/02/2020 12:38, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> Now that all architectures are converted to use the generic storage the
> helpers and conditionals can be removed.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> 
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

[...]

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[tip: timers/core] lib/vdso: Cleanup clock mode storage leftovers

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     c2130090f32165f4303202c7839dcbaf6bf943b6
Gitweb:        https://git.kernel.org/tip/c2130090f32165f4303202c7839dcbaf6bf943b6
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:59 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:25 +01:00

lib/vdso: Cleanup clock mode storage leftovers

Now that all architectures are converted to use the generic storage the
helpers and conditionals can be removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.470699892@linutronix.de


---
 arch/arm/mm/Kconfig                 |  1 -
 arch/arm64/Kconfig                  |  1 -
 arch/mips/Kconfig                   |  1 -
 arch/x86/Kconfig                    |  1 -
 include/asm-generic/vdso/vsyscall.h |  7 -------
 include/linux/clocksource.h         |  4 ++--
 kernel/time/vsyscall.c              |  4 ----
 lib/vdso/Kconfig                    |  3 ---
 lib/vdso/gettimeofday.c             | 17 +++++------------
 9 files changed, 7 insertions(+), 32 deletions(-)

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 865e888..65e4482 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -900,7 +900,6 @@ config VDSO
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_32
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_CLOCK_MODE
 	help
 	  Place in the process address space an ELF shared object
 	  providing fast implementations of gettimeofday and
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7809d49..c6c32fb 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -110,7 +110,6 @@ config ARM64
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_CLOCK_MODE
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_PCI
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 23b5c05..654369a 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -37,7 +37,6 @@ config MIPS
 	select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
-	select GENERIC_VDSO_CLOCK_MODE
 	select GUP_GET_PTE_LOW_HIGH if CPU_MIPS32 && PHYS_ADDR_T_64BIT
 	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_COMPILER_H
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 698e9c8..8b995db 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -125,7 +125,6 @@ config X86
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_CLOCK_MODE
 	select GENERIC_VDSO_TIME_NS
 	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
 	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
diff --git a/include/asm-generic/vdso/vsyscall.h b/include/asm-generic/vdso/vsyscall.h
index cec543d..4a28797 100644
--- a/include/asm-generic/vdso/vsyscall.h
+++ b/include/asm-generic/vdso/vsyscall.h
@@ -18,13 +18,6 @@ static __always_inline bool __arch_update_vdso_data(void)
 }
 #endif /* __arch_update_vdso_data */
 
-#ifndef __arch_get_clock_mode
-static __always_inline int __arch_get_clock_mode(struct timekeeper *tk)
-{
-	return 0;
-}
-#endif /* __arch_get_clock_mode */
-
 #ifndef __arch_update_vsyscall
 static __always_inline void __arch_update_vsyscall(struct vdso_data *vdata,
 						   struct timekeeper *tk)
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 6d5ed1b..7fefe0b 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -24,13 +24,13 @@ struct clocksource;
 struct module;
 
 #if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \
-    defined(CONFIG_GENERIC_VDSO_CLOCK_MODE)
+    defined(CONFIG_GENERIC_GETTIMEOFDAY)
 #include <asm/clocksource.h>
 #endif
 
 enum vdso_clock_mode {
 	VDSO_CLOCKMODE_NONE,
-#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+#ifdef CONFIG_GENERIC_GETTIMEOFDAY
 	VDSO_ARCH_CLOCKMODES,
 #endif
 	VDSO_CLOCKMODE_MAX,
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index f9a5178..d31a5ef 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -77,11 +77,7 @@ void update_vsyscall(struct timekeeper *tk)
 	/* copy vsyscall data */
 	vdso_write_begin(vdata);
 
-#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
 	clock_mode = tk->tkr_mono.clock->vdso_clock_mode;
-#else
-	clock_mode = __arch_get_clock_mode(tk);
-#endif
 	vdata[CS_HRES_COARSE].clock_mode	= clock_mode;
 	vdata[CS_RAW].clock_mode		= clock_mode;
 
diff --git a/lib/vdso/Kconfig b/lib/vdso/Kconfig
index d9f43c8..d883ac2 100644
--- a/lib/vdso/Kconfig
+++ b/lib/vdso/Kconfig
@@ -30,7 +30,4 @@ config GENERIC_VDSO_TIME_NS
 	  Selected by architectures which support time namespaces in the
 	  VDSO
 
-config GENERIC_VDSO_CLOCK_MODE
-	bool
-
 endif
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index 3f2d8b8..00f8d1f 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -65,16 +65,13 @@ static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 
 	do {
 		seq = vdso_read_begin(vd);
-		if (IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    vd->clock_mode == VDSO_CLOCKMODE_NONE)
+
+		if (unlikely(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 (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    unlikely((s64)cycles < 0))
-			return -1;
-
 		ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
 		ns >>= vd->shift;
 		sec = vdso_ts->sec;
@@ -137,16 +134,12 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 		}
 		smp_rmb();
 
-		if (IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    vd->clock_mode == VDSO_CLOCKMODE_NONE)
+		if (unlikely(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 (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    unlikely((s64)cycles < 0))
-			return -1;
-
 		ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
 		ns >>= vd->shift;
 		sec = vdso_ts->sec;

[tip: timers/core] lib/vdso: Cleanup clock mode storage leftovers

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     f86fd32db706613fe8d0104057efa6e83e0d7e8f
Gitweb:        https://git.kernel.org/tip/f86fd32db706613fe8d0104057efa6e83e0d7e8f
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:38:59 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 20:12:17 +01:00

lib/vdso: Cleanup clock mode storage leftovers

Now that all architectures are converted to use the generic storage the
helpers and conditionals can be removed.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.470699892@linutronix.de



---
 arch/arm/mm/Kconfig                 |  1 -
 arch/arm64/Kconfig                  |  1 -
 arch/mips/Kconfig                   |  1 -
 arch/x86/Kconfig                    |  1 -
 include/asm-generic/vdso/vsyscall.h |  7 -------
 include/linux/clocksource.h         |  4 ++--
 kernel/time/vsyscall.c              |  4 ----
 lib/vdso/Kconfig                    |  3 ---
 lib/vdso/gettimeofday.c             | 17 +++++------------
 9 files changed, 7 insertions(+), 32 deletions(-)

diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 865e888..65e4482 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -900,7 +900,6 @@ config VDSO
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_VDSO_32
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_CLOCK_MODE
 	help
 	  Place in the process address space an ELF shared object
 	  providing fast implementations of gettimeofday and
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 7809d49..c6c32fb 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -110,7 +110,6 @@ config ARM64
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_CLOCK_MODE
 	select HANDLE_DOMAIN_IRQ
 	select HARDIRQS_SW_RESEND
 	select HAVE_PCI
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 23b5c05..654369a 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -37,7 +37,6 @@ config MIPS
 	select GENERIC_SCHED_CLOCK if !CAVIUM_OCTEON_SOC
 	select GENERIC_SMP_IDLE_THREAD
 	select GENERIC_TIME_VSYSCALL
-	select GENERIC_VDSO_CLOCK_MODE
 	select GUP_GET_PTE_LOW_HIGH if CPU_MIPS32 && PHYS_ADDR_T_64BIT
 	select HANDLE_DOMAIN_IRQ
 	select HAVE_ARCH_COMPILER_H
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 698e9c8..8b995db 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -125,7 +125,6 @@ config X86
 	select GENERIC_STRNLEN_USER
 	select GENERIC_TIME_VSYSCALL
 	select GENERIC_GETTIMEOFDAY
-	select GENERIC_VDSO_CLOCK_MODE
 	select GENERIC_VDSO_TIME_NS
 	select GUP_GET_PTE_LOW_HIGH		if X86_PAE
 	select HARDLOCKUP_CHECK_TIMESTAMP	if X86_64
diff --git a/include/asm-generic/vdso/vsyscall.h b/include/asm-generic/vdso/vsyscall.h
index cec543d..4a28797 100644
--- a/include/asm-generic/vdso/vsyscall.h
+++ b/include/asm-generic/vdso/vsyscall.h
@@ -18,13 +18,6 @@ static __always_inline bool __arch_update_vdso_data(void)
 }
 #endif /* __arch_update_vdso_data */
 
-#ifndef __arch_get_clock_mode
-static __always_inline int __arch_get_clock_mode(struct timekeeper *tk)
-{
-	return 0;
-}
-#endif /* __arch_get_clock_mode */
-
 #ifndef __arch_update_vsyscall
 static __always_inline void __arch_update_vsyscall(struct vdso_data *vdata,
 						   struct timekeeper *tk)
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 6d5ed1b..7fefe0b 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -24,13 +24,13 @@ struct clocksource;
 struct module;
 
 #if defined(CONFIG_ARCH_CLOCKSOURCE_DATA) || \
-    defined(CONFIG_GENERIC_VDSO_CLOCK_MODE)
+    defined(CONFIG_GENERIC_GETTIMEOFDAY)
 #include <asm/clocksource.h>
 #endif
 
 enum vdso_clock_mode {
 	VDSO_CLOCKMODE_NONE,
-#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
+#ifdef CONFIG_GENERIC_GETTIMEOFDAY
 	VDSO_ARCH_CLOCKMODES,
 #endif
 	VDSO_CLOCKMODE_MAX,
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index f9a5178..d31a5ef 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -77,11 +77,7 @@ void update_vsyscall(struct timekeeper *tk)
 	/* copy vsyscall data */
 	vdso_write_begin(vdata);
 
-#ifdef CONFIG_GENERIC_VDSO_CLOCK_MODE
 	clock_mode = tk->tkr_mono.clock->vdso_clock_mode;
-#else
-	clock_mode = __arch_get_clock_mode(tk);
-#endif
 	vdata[CS_HRES_COARSE].clock_mode	= clock_mode;
 	vdata[CS_RAW].clock_mode		= clock_mode;
 
diff --git a/lib/vdso/Kconfig b/lib/vdso/Kconfig
index d9f43c8..d883ac2 100644
--- a/lib/vdso/Kconfig
+++ b/lib/vdso/Kconfig
@@ -30,7 +30,4 @@ config GENERIC_VDSO_TIME_NS
 	  Selected by architectures which support time namespaces in the
 	  VDSO
 
-config GENERIC_VDSO_CLOCK_MODE
-	bool
-
 endif
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index 3f2d8b8..00f8d1f 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -65,16 +65,13 @@ static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 
 	do {
 		seq = vdso_read_begin(vd);
-		if (IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    vd->clock_mode == VDSO_CLOCKMODE_NONE)
+
+		if (unlikely(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 (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    unlikely((s64)cycles < 0))
-			return -1;
-
 		ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
 		ns >>= vd->shift;
 		sec = vdso_ts->sec;
@@ -137,16 +134,12 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 		}
 		smp_rmb();
 
-		if (IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    vd->clock_mode == VDSO_CLOCKMODE_NONE)
+		if (unlikely(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 (!IS_ENABLED(CONFIG_GENERIC_VDSO_CLOCK_MODE) &&
-		    unlikely((s64)cycles < 0))
-			return -1;
-
 		ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
 		ns >>= vd->shift;
 		sec = vdso_ts->sec;

[patch V2 13/17] lib/vdso: Avoid highres update if clocksource is not VDSO capable

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.

Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
 arch/arm/include/asm/vdso/vsyscall.h |    7 -------
 include/asm-generic/vdso/vsyscall.h  |    7 -------
 kernel/time/vsyscall.c               |    6 +++---
 3 files changed, 3 insertions(+), 17 deletions(-)

--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -22,13 +22,6 @@ struct vdso_data *__arm_get_k_vdso_data(
 #define __arch_get_k_vdso_data __arm_get_k_vdso_data
 
 static __always_inline
-bool __arm_update_vdso_data(void)
-{
-	return cntvct_ok;
-}
-#define __arch_update_vdso_data __arm_update_vdso_data
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));
--- a/include/asm-generic/vdso/vsyscall.h
+++ b/include/asm-generic/vdso/vsyscall.h
@@ -11,13 +11,6 @@ static __always_inline struct vdso_data
 }
 #endif /* __arch_get_k_vdso_data */
 
-#ifndef __arch_update_vdso_data
-static __always_inline bool __arch_update_vdso_data(void)
-{
-	return true;
-}
-#endif /* __arch_update_vdso_data */
-
 #ifndef __arch_update_vsyscall
 static __always_inline void __arch_update_vsyscall(struct vdso_data *vdata,
 						   struct timekeeper *tk)
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -105,10 +105,10 @@ void update_vsyscall(struct timekeeper *
 	WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
 
 	/*
-	 * Architectures can opt out of updating the high resolution part
-	 * of the VDSO.
+	 * If the current clocksource is not VDSO capable, then spare the
+	 * update of the high reolution parts.
 	 */
-	if (__arch_update_vdso_data())
+	if (clock_mode != VDSO_CLOCKMODE_NONE)
 		update_vdso_data(vdata, tk);
 
 	__arch_update_vsyscall(vdata, tk);

Re: [patch V2 13/17] lib/vdso: Avoid highres update if clocksource is not VDSO capable

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 575 bytes --]



On 07/02/2020 12:39, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> If the current clocksource is not VDSO capable there is no point in
> updating the high resolution parts of the VDSO data.
> 
> Replace the architecture specific check with a check for a VDSO capable
> clocksource and skip the update if there is none.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>


Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

[...]

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[tip: timers/core] lib/vdso: Avoid highres update if clocksource is not VDSO capable

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     ae3003fdec352e0d474a98ebf1617d48a945aa5a
Gitweb:        https://git.kernel.org/tip/ae3003fdec352e0d474a98ebf1617d48a945aa5a
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:39:00 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:26 +01:00

lib/vdso: Avoid highres update if clocksource is not VDSO capable

If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.

Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de

---
 arch/arm/include/asm/vdso/vsyscall.h | 7 -------
 include/asm-generic/vdso/vsyscall.h  | 7 -------
 kernel/time/vsyscall.c               | 6 +++---
 3 files changed, 3 insertions(+), 17 deletions(-)

diff --git a/arch/arm/include/asm/vdso/vsyscall.h b/arch/arm/include/asm/vdso/vsyscall.h
index 002f9ed..47e41ae 100644
--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -22,13 +22,6 @@ struct vdso_data *__arm_get_k_vdso_data(void)
 #define __arch_get_k_vdso_data __arm_get_k_vdso_data
 
 static __always_inline
-bool __arm_update_vdso_data(void)
-{
-	return cntvct_ok;
-}
-#define __arch_update_vdso_data __arm_update_vdso_data
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));
diff --git a/include/asm-generic/vdso/vsyscall.h b/include/asm-generic/vdso/vsyscall.h
index 4a28797..c835607 100644
--- a/include/asm-generic/vdso/vsyscall.h
+++ b/include/asm-generic/vdso/vsyscall.h
@@ -11,13 +11,6 @@ static __always_inline struct vdso_data *__arch_get_k_vdso_data(void)
 }
 #endif /* __arch_get_k_vdso_data */
 
-#ifndef __arch_update_vdso_data
-static __always_inline bool __arch_update_vdso_data(void)
-{
-	return true;
-}
-#endif /* __arch_update_vdso_data */
-
 #ifndef __arch_update_vsyscall
 static __always_inline void __arch_update_vsyscall(struct vdso_data *vdata,
 						   struct timekeeper *tk)
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index d31a5ef..54ce6eb 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -105,10 +105,10 @@ void update_vsyscall(struct timekeeper *tk)
 	WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
 
 	/*
-	 * Architectures can opt out of updating the high resolution part
-	 * of the VDSO.
+	 * If the current clocksource is not VDSO capable, then spare the
+	 * update of the high reolution parts.
 	 */
-	if (__arch_update_vdso_data())
+	if (clock_mode != VDSO_CLOCKMODE_NONE)
 		update_vdso_data(vdata, tk);
 
 	__arch_update_vsyscall(vdata, tk);

[tip: timers/core] lib/vdso: Avoid highres update if clocksource is not VDSO capable

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     c7a18100bdffdff440c7291db6e80863fab0461e
Gitweb:        https://git.kernel.org/tip/c7a18100bdffdff440c7291db6e80863fab0461e
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:39:00 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 20:12:17 +01:00

lib/vdso: Avoid highres update if clocksource is not VDSO capable

If the current clocksource is not VDSO capable there is no point in
updating the high resolution parts of the VDSO data.

Replace the architecture specific check with a check for a VDSO capable
clocksource and skip the update if there is none.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.563379423@linutronix.de


---
 arch/arm/include/asm/vdso/vsyscall.h | 7 -------
 include/asm-generic/vdso/vsyscall.h  | 7 -------
 kernel/time/vsyscall.c               | 6 +++---
 3 files changed, 3 insertions(+), 17 deletions(-)

diff --git a/arch/arm/include/asm/vdso/vsyscall.h b/arch/arm/include/asm/vdso/vsyscall.h
index 002f9ed..47e41ae 100644
--- a/arch/arm/include/asm/vdso/vsyscall.h
+++ b/arch/arm/include/asm/vdso/vsyscall.h
@@ -22,13 +22,6 @@ struct vdso_data *__arm_get_k_vdso_data(void)
 #define __arch_get_k_vdso_data __arm_get_k_vdso_data
 
 static __always_inline
-bool __arm_update_vdso_data(void)
-{
-	return cntvct_ok;
-}
-#define __arch_update_vdso_data __arm_update_vdso_data
-
-static __always_inline
 void __arm_sync_vdso_data(struct vdso_data *vdata)
 {
 	flush_dcache_page(virt_to_page(vdata));
diff --git a/include/asm-generic/vdso/vsyscall.h b/include/asm-generic/vdso/vsyscall.h
index 4a28797..c835607 100644
--- a/include/asm-generic/vdso/vsyscall.h
+++ b/include/asm-generic/vdso/vsyscall.h
@@ -11,13 +11,6 @@ static __always_inline struct vdso_data *__arch_get_k_vdso_data(void)
 }
 #endif /* __arch_get_k_vdso_data */
 
-#ifndef __arch_update_vdso_data
-static __always_inline bool __arch_update_vdso_data(void)
-{
-	return true;
-}
-#endif /* __arch_update_vdso_data */
-
 #ifndef __arch_update_vsyscall
 static __always_inline void __arch_update_vsyscall(struct vdso_data *vdata,
 						   struct timekeeper *tk)
diff --git a/kernel/time/vsyscall.c b/kernel/time/vsyscall.c
index d31a5ef..54ce6eb 100644
--- a/kernel/time/vsyscall.c
+++ b/kernel/time/vsyscall.c
@@ -105,10 +105,10 @@ void update_vsyscall(struct timekeeper *tk)
 	WRITE_ONCE(vdata[CS_HRES_COARSE].hrtimer_res, hrtimer_resolution);
 
 	/*
-	 * Architectures can opt out of updating the high resolution part
-	 * of the VDSO.
+	 * If the current clocksource is not VDSO capable, then spare the
+	 * update of the high reolution parts.
 	 */
-	if (__arch_update_vdso_data())
+	if (clock_mode != VDSO_CLOCKMODE_NONE)
 		update_vdso_data(vdata, tk);
 
 	__arch_update_vsyscall(vdata, tk);

[patch V2 14/17] lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes

[Thomas Gleixner]

From: Thomas Gleixner <tglx@linutronix.de>

Move the time namespace indicator clock mode to the other ones for
consistency sake.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 include/linux/clocksource.h |    3 +++
 include/vdso/datapage.h     |    2 --
 kernel/time/namespace.c     |    7 ++++---
 lib/vdso/gettimeofday.c     |   18 ++++++++++--------
 4 files changed, 17 insertions(+), 13 deletions(-)

--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -34,6 +34,9 @@ enum vdso_clock_mode {
 	VDSO_ARCH_CLOCKMODES,
 #endif
 	VDSO_CLOCKMODE_MAX,
+
+	/* Indicator for time namespace VDSO */
+	VDSO_CLOCKMODE_TIMENS = INT_MAX
 };
 
 /**
--- a/include/vdso/datapage.h
+++ b/include/vdso/datapage.h
@@ -21,8 +21,6 @@
 #define CS_RAW		1
 #define CS_BASES	(CS_RAW + 1)
 
-#define VCLOCK_TIMENS	UINT_MAX
-
 /**
  * struct vdso_timestamp - basetime per clock_id
  * @sec:	seconds
--- a/kernel/time/namespace.c
+++ b/kernel/time/namespace.c
@@ -8,6 +8,7 @@
 #include <linux/user_namespace.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/task.h>
+#include <linux/clocksource.h>
 #include <linux/seq_file.h>
 #include <linux/proc_ns.h>
 #include <linux/export.h>
@@ -172,8 +173,8 @@ static struct timens_offset offset_from_
  * for vdso_data->clock_mode is a non-issue. The task is spin waiting for the
  * update to finish and for 'seq' to become even anyway.
  *
- * Timens page has vdso_data->clock_mode set to VCLOCK_TIMENS which enforces
- * the time namespace handling path.
+ * Timens page has vdso_data->clock_mode set to VDSO_CLOCKMODE_TIMENS which
+ * enforces the time namespace handling path.
  */
 static void timens_setup_vdso_data(struct vdso_data *vdata,
 				   struct time_namespace *ns)
@@ -183,7 +184,7 @@ static void timens_setup_vdso_data(struc
 	struct timens_offset boottime = offset_from_ts(ns->offsets.boottime);
 
 	vdata->seq			= 1;
-	vdata->clock_mode		= VCLOCK_TIMENS;
+	vdata->clock_mode		= VDSO_CLOCKMODE_TIMENS;
 	offset[CLOCK_MONOTONIC]		= monotonic;
 	offset[CLOCK_MONOTONIC_RAW]	= monotonic;
 	offset[CLOCK_MONOTONIC_COARSE]	= monotonic;
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -116,10 +116,10 @@ static __always_inline int do_hres(const
 
 	do {
 		/*
-		 * Open coded to handle VCLOCK_TIMENS. Time namespace
+		 * Open coded to handle VDSO_CLOCKMODE_TIMENS. Time namespace
 		 * enabled tasks have a special VVAR page installed which
 		 * has vd->seq set to 1 and vd->clock_mode set to
-		 * VCLOCK_TIMENS. For non time namespace affected tasks
+		 * VDSO_CLOCKMODE_TIMENS. For non time namespace affected tasks
 		 * this does not affect performance because if vd->seq is
 		 * odd, i.e. a concurrent update is in progress the extra
 		 * check for vd->clock_mode is just a few extra
@@ -128,7 +128,7 @@ static __always_inline int do_hres(const
 		 */
 		while (unlikely((seq = READ_ONCE(vd->seq)) & 1)) {
 			if (IS_ENABLED(CONFIG_TIME_NS) &&
-			    vd->clock_mode == VCLOCK_TIMENS)
+			    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 				return do_hres_timens(vd, clk, ts);
 			cpu_relax();
 		}
@@ -200,12 +200,12 @@ static __always_inline int do_coarse(con
 
 	do {
 		/*
-		 * Open coded to handle VCLOCK_TIMENS. See comment in
+		 * Open coded to handle VDSO_CLOCK_TIMENS. See comment in
 		 * do_hres().
 		 */
 		while ((seq = READ_ONCE(vd->seq)) & 1) {
 			if (IS_ENABLED(CONFIG_TIME_NS) &&
-			    vd->clock_mode == VCLOCK_TIMENS)
+			    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 				return do_coarse_timens(vd, clk, ts);
 			cpu_relax();
 		}
@@ -292,7 +292,7 @@ static __maybe_unused int
 
 	if (unlikely(tz != NULL)) {
 		if (IS_ENABLED(CONFIG_TIME_NS) &&
-		    vd->clock_mode == VCLOCK_TIMENS)
+		    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 			vd = __arch_get_timens_vdso_data();
 
 		tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
@@ -308,7 +308,8 @@ static __maybe_unused __kernel_old_time_
 	const struct vdso_data *vd = __arch_get_vdso_data();
 	__kernel_old_time_t t;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) && vd->clock_mode == VCLOCK_TIMENS)
+	if (IS_ENABLED(CONFIG_TIME_NS) &&
+	    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 		vd = __arch_get_timens_vdso_data();
 
 	t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec);
@@ -332,7 +333,8 @@ int __cvdso_clock_getres_common(clockid_
 	if (unlikely((u32) clock >= MAX_CLOCKS))
 		return -1;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) && vd->clock_mode == VCLOCK_TIMENS)
+	if (IS_ENABLED(CONFIG_TIME_NS) &&
+	    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 		vd = __arch_get_timens_vdso_data();
 
 	/*

Re: [patch V2 14/17] lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 347 bytes --]

On 07/02/2020 12:39, Thomas Gleixner wrote:
> From: Thomas Gleixner <tglx@linutronix.de>
> 
> Move the time namespace indicator clock mode to the other ones for
> consistency sake.
> 
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> 

Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

[...]

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[tip: timers/core] lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     80bebf447de9fe2d7a0fe4dd795aa057e2293205
Gitweb:        https://git.kernel.org/tip/80bebf447de9fe2d7a0fe4dd795aa057e2293205
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:39:01 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:27 +01:00

lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes

Move the time namespace indicator clock mode to the other ones for
consistency sake.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.656097274@linutronix.de


---
 include/linux/clocksource.h |  3 +++
 include/vdso/datapage.h     |  2 --
 kernel/time/namespace.c     |  7 ++++---
 lib/vdso/gettimeofday.c     | 18 ++++++++++--------
 4 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 7fefe0b..02e3282 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -34,6 +34,9 @@ enum vdso_clock_mode {
 	VDSO_ARCH_CLOCKMODES,
 #endif
 	VDSO_CLOCKMODE_MAX,
+
+	/* Indicator for time namespace VDSO */
+	VDSO_CLOCKMODE_TIMENS = INT_MAX
 };
 
 /**
diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h
index c5f347c..30c4cb0 100644
--- a/include/vdso/datapage.h
+++ b/include/vdso/datapage.h
@@ -21,8 +21,6 @@
 #define CS_RAW		1
 #define CS_BASES	(CS_RAW + 1)
 
-#define VCLOCK_TIMENS	UINT_MAX
-
 /**
  * struct vdso_timestamp - basetime per clock_id
  * @sec:	seconds
diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c
index 1285850..e6ba064 100644
--- a/kernel/time/namespace.c
+++ b/kernel/time/namespace.c
@@ -8,6 +8,7 @@
 #include <linux/user_namespace.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/task.h>
+#include <linux/clocksource.h>
 #include <linux/seq_file.h>
 #include <linux/proc_ns.h>
 #include <linux/export.h>
@@ -172,8 +173,8 @@ static struct timens_offset offset_from_ts(struct timespec64 off)
  * for vdso_data->clock_mode is a non-issue. The task is spin waiting for the
  * update to finish and for 'seq' to become even anyway.
  *
- * Timens page has vdso_data->clock_mode set to VCLOCK_TIMENS which enforces
- * the time namespace handling path.
+ * Timens page has vdso_data->clock_mode set to VDSO_CLOCKMODE_TIMENS which
+ * enforces the time namespace handling path.
  */
 static void timens_setup_vdso_data(struct vdso_data *vdata,
 				   struct time_namespace *ns)
@@ -183,7 +184,7 @@ static void timens_setup_vdso_data(struct vdso_data *vdata,
 	struct timens_offset boottime = offset_from_ts(ns->offsets.boottime);
 
 	vdata->seq			= 1;
-	vdata->clock_mode		= VCLOCK_TIMENS;
+	vdata->clock_mode		= VDSO_CLOCKMODE_TIMENS;
 	offset[CLOCK_MONOTONIC]		= monotonic;
 	offset[CLOCK_MONOTONIC_RAW]	= monotonic;
 	offset[CLOCK_MONOTONIC_COARSE]	= monotonic;
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index 00f8d1f..a76ac8d 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -116,10 +116,10 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 
 	do {
 		/*
-		 * Open coded to handle VCLOCK_TIMENS. Time namespace
+		 * Open coded to handle VDSO_CLOCKMODE_TIMENS. Time namespace
 		 * enabled tasks have a special VVAR page installed which
 		 * has vd->seq set to 1 and vd->clock_mode set to
-		 * VCLOCK_TIMENS. For non time namespace affected tasks
+		 * VDSO_CLOCKMODE_TIMENS. For non time namespace affected tasks
 		 * this does not affect performance because if vd->seq is
 		 * odd, i.e. a concurrent update is in progress the extra
 		 * check for vd->clock_mode is just a few extra
@@ -128,7 +128,7 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 		 */
 		while (unlikely((seq = READ_ONCE(vd->seq)) & 1)) {
 			if (IS_ENABLED(CONFIG_TIME_NS) &&
-			    vd->clock_mode == VCLOCK_TIMENS)
+			    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 				return do_hres_timens(vd, clk, ts);
 			cpu_relax();
 		}
@@ -200,12 +200,12 @@ static __always_inline int do_coarse(const struct vdso_data *vd, clockid_t clk,
 
 	do {
 		/*
-		 * Open coded to handle VCLOCK_TIMENS. See comment in
+		 * Open coded to handle VDSO_CLOCK_TIMENS. See comment in
 		 * do_hres().
 		 */
 		while ((seq = READ_ONCE(vd->seq)) & 1) {
 			if (IS_ENABLED(CONFIG_TIME_NS) &&
-			    vd->clock_mode == VCLOCK_TIMENS)
+			    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 				return do_coarse_timens(vd, clk, ts);
 			cpu_relax();
 		}
@@ -292,7 +292,7 @@ __cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
 
 	if (unlikely(tz != NULL)) {
 		if (IS_ENABLED(CONFIG_TIME_NS) &&
-		    vd->clock_mode == VCLOCK_TIMENS)
+		    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 			vd = __arch_get_timens_vdso_data();
 
 		tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
@@ -308,7 +308,8 @@ static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time
 	const struct vdso_data *vd = __arch_get_vdso_data();
 	__kernel_old_time_t t;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) && vd->clock_mode == VCLOCK_TIMENS)
+	if (IS_ENABLED(CONFIG_TIME_NS) &&
+	    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 		vd = __arch_get_timens_vdso_data();
 
 	t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec);
@@ -332,7 +333,8 @@ int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res)
 	if (unlikely((u32) clock >= MAX_CLOCKS))
 		return -1;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) && vd->clock_mode == VCLOCK_TIMENS)
+	if (IS_ENABLED(CONFIG_TIME_NS) &&
+	    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 		vd = __arch_get_timens_vdso_data();
 
 	/*

[tip: timers/core] lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes

[tip-bot2 for Thomas Gleixner]

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

Commit-ID:     2d6b01bd88ccabba06d342ef80eaab6b39d12497
Gitweb:        https://git.kernel.org/tip/2d6b01bd88ccabba06d342ef80eaab6b39d12497
Author:        Thomas Gleixner <tglx@linutronix.de>
AuthorDate:    Fri, 07 Feb 2020 13:39:01 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 20:12:17 +01:00

lib/vdso: Move VCLOCK_TIMENS to vdso_clock_modes

Move the time namespace indicator clock mode to the other ones for
consistency sake.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.656097274@linutronix.de



---
 include/linux/clocksource.h |  3 +++
 include/vdso/datapage.h     |  2 --
 kernel/time/namespace.c     |  7 ++++---
 lib/vdso/gettimeofday.c     | 18 ++++++++++--------
 4 files changed, 17 insertions(+), 13 deletions(-)

diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 7fefe0b..02e3282 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -34,6 +34,9 @@ enum vdso_clock_mode {
 	VDSO_ARCH_CLOCKMODES,
 #endif
 	VDSO_CLOCKMODE_MAX,
+
+	/* Indicator for time namespace VDSO */
+	VDSO_CLOCKMODE_TIMENS = INT_MAX
 };
 
 /**
diff --git a/include/vdso/datapage.h b/include/vdso/datapage.h
index c5f347c..30c4cb0 100644
--- a/include/vdso/datapage.h
+++ b/include/vdso/datapage.h
@@ -21,8 +21,6 @@
 #define CS_RAW		1
 #define CS_BASES	(CS_RAW + 1)
 
-#define VCLOCK_TIMENS	UINT_MAX
-
 /**
  * struct vdso_timestamp - basetime per clock_id
  * @sec:	seconds
diff --git a/kernel/time/namespace.c b/kernel/time/namespace.c
index 1285850..e6ba064 100644
--- a/kernel/time/namespace.c
+++ b/kernel/time/namespace.c
@@ -8,6 +8,7 @@
 #include <linux/user_namespace.h>
 #include <linux/sched/signal.h>
 #include <linux/sched/task.h>
+#include <linux/clocksource.h>
 #include <linux/seq_file.h>
 #include <linux/proc_ns.h>
 #include <linux/export.h>
@@ -172,8 +173,8 @@ static struct timens_offset offset_from_ts(struct timespec64 off)
  * for vdso_data->clock_mode is a non-issue. The task is spin waiting for the
  * update to finish and for 'seq' to become even anyway.
  *
- * Timens page has vdso_data->clock_mode set to VCLOCK_TIMENS which enforces
- * the time namespace handling path.
+ * Timens page has vdso_data->clock_mode set to VDSO_CLOCKMODE_TIMENS which
+ * enforces the time namespace handling path.
  */
 static void timens_setup_vdso_data(struct vdso_data *vdata,
 				   struct time_namespace *ns)
@@ -183,7 +184,7 @@ static void timens_setup_vdso_data(struct vdso_data *vdata,
 	struct timens_offset boottime = offset_from_ts(ns->offsets.boottime);
 
 	vdata->seq			= 1;
-	vdata->clock_mode		= VCLOCK_TIMENS;
+	vdata->clock_mode		= VDSO_CLOCKMODE_TIMENS;
 	offset[CLOCK_MONOTONIC]		= monotonic;
 	offset[CLOCK_MONOTONIC_RAW]	= monotonic;
 	offset[CLOCK_MONOTONIC_COARSE]	= monotonic;
diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index 00f8d1f..a76ac8d 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -116,10 +116,10 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 
 	do {
 		/*
-		 * Open coded to handle VCLOCK_TIMENS. Time namespace
+		 * Open coded to handle VDSO_CLOCKMODE_TIMENS. Time namespace
 		 * enabled tasks have a special VVAR page installed which
 		 * has vd->seq set to 1 and vd->clock_mode set to
-		 * VCLOCK_TIMENS. For non time namespace affected tasks
+		 * VDSO_CLOCKMODE_TIMENS. For non time namespace affected tasks
 		 * this does not affect performance because if vd->seq is
 		 * odd, i.e. a concurrent update is in progress the extra
 		 * check for vd->clock_mode is just a few extra
@@ -128,7 +128,7 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 		 */
 		while (unlikely((seq = READ_ONCE(vd->seq)) & 1)) {
 			if (IS_ENABLED(CONFIG_TIME_NS) &&
-			    vd->clock_mode == VCLOCK_TIMENS)
+			    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 				return do_hres_timens(vd, clk, ts);
 			cpu_relax();
 		}
@@ -200,12 +200,12 @@ static __always_inline int do_coarse(const struct vdso_data *vd, clockid_t clk,
 
 	do {
 		/*
-		 * Open coded to handle VCLOCK_TIMENS. See comment in
+		 * Open coded to handle VDSO_CLOCK_TIMENS. See comment in
 		 * do_hres().
 		 */
 		while ((seq = READ_ONCE(vd->seq)) & 1) {
 			if (IS_ENABLED(CONFIG_TIME_NS) &&
-			    vd->clock_mode == VCLOCK_TIMENS)
+			    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 				return do_coarse_timens(vd, clk, ts);
 			cpu_relax();
 		}
@@ -292,7 +292,7 @@ __cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
 
 	if (unlikely(tz != NULL)) {
 		if (IS_ENABLED(CONFIG_TIME_NS) &&
-		    vd->clock_mode == VCLOCK_TIMENS)
+		    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 			vd = __arch_get_timens_vdso_data();
 
 		tz->tz_minuteswest = vd[CS_HRES_COARSE].tz_minuteswest;
@@ -308,7 +308,8 @@ static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time
 	const struct vdso_data *vd = __arch_get_vdso_data();
 	__kernel_old_time_t t;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) && vd->clock_mode == VCLOCK_TIMENS)
+	if (IS_ENABLED(CONFIG_TIME_NS) &&
+	    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 		vd = __arch_get_timens_vdso_data();
 
 	t = READ_ONCE(vd[CS_HRES_COARSE].basetime[CLOCK_REALTIME].sec);
@@ -332,7 +333,8 @@ int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res)
 	if (unlikely((u32) clock >= MAX_CLOCKS))
 		return -1;
 
-	if (IS_ENABLED(CONFIG_TIME_NS) && vd->clock_mode == VCLOCK_TIMENS)
+	if (IS_ENABLED(CONFIG_TIME_NS) &&
+	    vd->clock_mode == VDSO_CLOCKMODE_TIMENS)
 		vd = __arch_get_timens_vdso_data();
 
 	/*

[patch V2 15/17] lib/vdso: Allow fixed clock mode

[Thomas Gleixner]

From: Christophe Leroy <christophe.leroy@c-s.fr>

Some architectures have a fixed clocksource which is known at compile time
and cannot be replaced or disabled at runtime, e.g. timebase on
PowerPC. For such cases the clock mode check in the VDSO code is pointless.

Move the check for a VDSO capable clocksource into an inline function and
allow architectures to redefine it via a macro.

[ tglx: Removed the #ifdef mess ]

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

---
 lib/vdso/gettimeofday.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -46,6 +46,13 @@ static inline bool __arch_vdso_hres_capa
 }
 #endif
 
+#ifndef vdso_clocksource_ok
+static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
+{
+	return vd->clock_mode != VDSO_CLOCKMODE_NONE;
+}
+#endif
+
 #ifdef CONFIG_TIME_NS
 static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 			  struct __kernel_timespec *ts)
@@ -66,7 +73,7 @@ static int do_hres_timens(const struct v
 	do {
 		seq = vdso_read_begin(vd);
 
-		if (unlikely(vd->clock_mode == VDSO_CLOCKMODE_NONE))
+		if (unlikely(!vdso_clocksource_ok(vd)))
 			return -1;
 
 		cycles = __arch_get_hw_counter(vd->clock_mode);
@@ -134,7 +141,7 @@ static __always_inline int do_hres(const
 		}
 		smp_rmb();
 
-		if (unlikely(vd->clock_mode == VDSO_CLOCKMODE_NONE))
+		if (unlikely(!vdso_clocksource_ok(vd)))
 			return -1;
 
 		cycles = __arch_get_hw_counter(vd->clock_mode);

Re: [patch V2 15/17] lib/vdso: Allow fixed clock mode

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 780 bytes --]

On 07/02/2020 12:39, Thomas Gleixner wrote:
> From: Christophe Leroy <christophe.leroy@c-s.fr>
> 
> Some architectures have a fixed clocksource which is known at compile time
> and cannot be replaced or disabled at runtime, e.g. timebase on
> PowerPC. For such cases the clock mode check in the VDSO code is pointless.
> 
> Move the check for a VDSO capable clocksource into an inline function and
> allow architectures to redefine it via a macro.
> 
> [ tglx: Removed the #ifdef mess ]
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> 


Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

[...]

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[tip: timers/core] lib/vdso: Allow fixed clock mode

[tip-bot2 for Christophe Leroy]

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

Commit-ID:     997cf1781d0a694952048de2705f755d2c8c1bcd
Gitweb:        https://git.kernel.org/tip/997cf1781d0a694952048de2705f755d2c8c1bcd
Author:        Christophe Leroy <christophe.leroy@c-s.fr>
AuthorDate:    Fri, 07 Feb 2020 13:39:02 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 14:40:28 +01:00

lib/vdso: Allow fixed clock mode

Some architectures have a fixed clocksource which is known at compile time
and cannot be replaced or disabled at runtime, e.g. timebase on
PowerPC. For such cases the clock mode check in the VDSO code is pointless.

Move the check for a VDSO capable clocksource into an inline function and
allow architectures to redefine it via a macro.

[ tglx: Removed the #ifdef mess ]

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.748756829@linutronix.de


---
 lib/vdso/gettimeofday.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index a76ac8d..8eb6d1e 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -46,6 +46,13 @@ static inline bool __arch_vdso_hres_capable(void)
 }
 #endif
 
+#ifndef vdso_clocksource_ok
+static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
+{
+	return vd->clock_mode != VDSO_CLOCKMODE_NONE;
+}
+#endif
+
 #ifdef CONFIG_TIME_NS
 static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 			  struct __kernel_timespec *ts)
@@ -66,7 +73,7 @@ static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 	do {
 		seq = vdso_read_begin(vd);
 
-		if (unlikely(vd->clock_mode == VDSO_CLOCKMODE_NONE))
+		if (unlikely(!vdso_clocksource_ok(vd)))
 			return -1;
 
 		cycles = __arch_get_hw_counter(vd->clock_mode);
@@ -134,7 +141,7 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 		}
 		smp_rmb();
 
-		if (unlikely(vd->clock_mode == VDSO_CLOCKMODE_NONE))
+		if (unlikely(!vdso_clocksource_ok(vd)))
 			return -1;
 
 		cycles = __arch_get_hw_counter(vd->clock_mode);

[tip: timers/core] lib/vdso: Allow fixed clock mode

[tip-bot2 for Christophe Leroy]

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

Commit-ID:     ae12e08539de6717502c2f9f83bd60df939b5c08
Gitweb:        https://git.kernel.org/tip/ae12e08539de6717502c2f9f83bd60df939b5c08
Author:        Christophe Leroy <christophe.leroy@c-s.fr>
AuthorDate:    Fri, 07 Feb 2020 13:39:02 +01:00
Committer:     Thomas Gleixner <tglx@linutronix.de>
CommitterDate: Mon, 17 Feb 2020 20:12:18 +01:00

lib/vdso: Allow fixed clock mode

Some architectures have a fixed clocksource which is known at compile time
and cannot be replaced or disabled at runtime, e.g. timebase on
PowerPC. For such cases the clock mode check in the VDSO code is pointless.

Move the check for a VDSO capable clocksource into an inline function and
allow architectures to redefine it via a macro.

[ tglx: Removed the #ifdef mess ]

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lkml.kernel.org/r/20200207124403.748756829@linutronix.de



---
 lib/vdso/gettimeofday.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/lib/vdso/gettimeofday.c b/lib/vdso/gettimeofday.c
index a76ac8d..8eb6d1e 100644
--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -46,6 +46,13 @@ static inline bool __arch_vdso_hres_capable(void)
 }
 #endif
 
+#ifndef vdso_clocksource_ok
+static inline bool vdso_clocksource_ok(const struct vdso_data *vd)
+{
+	return vd->clock_mode != VDSO_CLOCKMODE_NONE;
+}
+#endif
+
 #ifdef CONFIG_TIME_NS
 static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 			  struct __kernel_timespec *ts)
@@ -66,7 +73,7 @@ static int do_hres_timens(const struct vdso_data *vdns, clockid_t clk,
 	do {
 		seq = vdso_read_begin(vd);
 
-		if (unlikely(vd->clock_mode == VDSO_CLOCKMODE_NONE))
+		if (unlikely(!vdso_clocksource_ok(vd)))
 			return -1;
 
 		cycles = __arch_get_hw_counter(vd->clock_mode);
@@ -134,7 +141,7 @@ static __always_inline int do_hres(const struct vdso_data *vd, clockid_t clk,
 		}
 		smp_rmb();
 
-		if (unlikely(vd->clock_mode == VDSO_CLOCKMODE_NONE))
+		if (unlikely(!vdso_clocksource_ok(vd)))
 			return -1;
 
 		cycles = __arch_get_hw_counter(vd->clock_mode);

[patch V2 16/17] lib/vdso: Allow architectures to override the ns shift operation

[Thomas Gleixner]

From: Christophe Leroy <christophe.leroy@c-s.fr>

On powerpc/32, GCC (8.1) generates pretty bad code for the ns >>= vd->shift
operation taking into account that the shift is always <= 32 and the upper
part of the result is likely to be zero. GCC makes reversed assumptions
considering the shift to be likely >= 32 and the upper part to be like not
zero.

unsigned long long shift(unsigned long long x, unsigned char s)
{
	return x >> s;
}

results in:

00000018 <shift>:
  18:	35 25 ff e0 	addic.  r9,r5,-32
  1c:	41 80 00 10 	blt     2c <shift+0x14>
  20:	7c 64 4c 30 	srw     r4,r3,r9
  24:	38 60 00 00 	li      r3,0
  28:	4e 80 00 20 	blr
  2c:	54 69 08 3c 	rlwinm  r9,r3,1,0,30
  30:	21 45 00 1f 	subfic  r10,r5,31
  34:	7c 84 2c 30 	srw     r4,r4,r5
  38:	7d 29 50 30 	slw     r9,r9,r10
  3c:	7c 63 2c 30 	srw     r3,r3,r5
  40:	7d 24 23 78 	or      r4,r9,r4
  44:	4e 80 00 20 	blr

Even when forcing the shift to be smaller than 32 with an &= 31, it still
considers the shift as likely >= 32.

Move the default shift implementation into an inline which can be redefined
in architecture code via a macro.

[ tglx: Made the shift argument u32 and removed the __arch prefix ]

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/b3d449de856982ed060a71e6ace8eeca4654e685.1580399657.git.christophe.leroy@c-s.fr

---
 lib/vdso/gettimeofday.c |   11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -39,6 +39,13 @@ u64 vdso_calc_delta(u64 cycles, u64 last
 }
 #endif
 
+#ifndef vdso_shift_ns
+static __always_inline u64 vdso_shift_ns(u64 ns, u32 shift)
+{
+	return ns >> shift;
+}
+#endif
+
 #ifndef __arch_vdso_hres_capable
 static inline bool __arch_vdso_hres_capable(void)
 {
@@ -80,7 +87,7 @@ static int do_hres_timens(const struct v
 		ns = vdso_ts->nsec;
 		last = vd->cycle_last;
 		ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
-		ns >>= vd->shift;
+		ns = vdso_shift_ns(ns, vd->shift);
 		sec = vdso_ts->sec;
 	} while (unlikely(vdso_read_retry(vd, seq)));
 
@@ -148,7 +155,7 @@ static __always_inline int do_hres(const
 		ns = vdso_ts->nsec;
 		last = vd->cycle_last;
 		ns += vdso_calc_delta(cycles, last, vd->mask, vd->mult);
-		ns >>= vd->shift;
+		ns = vdso_shift_ns(ns, vd->shift);
 		sec = vdso_ts->sec;
 	} while (unlikely(vdso_read_retry(vd, seq)));
 

Re: [patch V2 16/17] lib/vdso: Allow architectures to override the ns shift operation

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 1727 bytes --]

On 07/02/2020 12:39, Thomas Gleixner wrote:
> From: Christophe Leroy <christophe.leroy@c-s.fr>
> 
> On powerpc/32, GCC (8.1) generates pretty bad code for the ns >>= vd->shift
> operation taking into account that the shift is always <= 32 and the upper
> part of the result is likely to be zero. GCC makes reversed assumptions
> considering the shift to be likely >= 32 and the upper part to be like not
> zero.
> 
> unsigned long long shift(unsigned long long x, unsigned char s)
> {
> 	return x >> s;
> }
> 
> results in:
> 
> 00000018 <shift>:
>   18:	35 25 ff e0 	addic.  r9,r5,-32
>   1c:	41 80 00 10 	blt     2c <shift+0x14>
>   20:	7c 64 4c 30 	srw     r4,r3,r9
>   24:	38 60 00 00 	li      r3,0
>   28:	4e 80 00 20 	blr
>   2c:	54 69 08 3c 	rlwinm  r9,r3,1,0,30
>   30:	21 45 00 1f 	subfic  r10,r5,31
>   34:	7c 84 2c 30 	srw     r4,r4,r5
>   38:	7d 29 50 30 	slw     r9,r9,r10
>   3c:	7c 63 2c 30 	srw     r3,r3,r5
>   40:	7d 24 23 78 	or      r4,r9,r4
>   44:	4e 80 00 20 	blr
> 
> Even when forcing the shift to be smaller than 32 with an &= 31, it still
> considers the shift as likely >= 32.
> 
> Move the default shift implementation into an inline which can be redefined
> in architecture code via a macro.
> 
> [ tglx: Made the shift argument u32 and removed the __arch prefix ]
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Link: https://lore.kernel.org/r/b3d449de856982ed060a71e6ace8eeca4654e685.1580399657.git.christophe.leroy@c-s.fr
> 


Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

[...]
-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]

[patch V2 17/17] lib/vdso: Allow architectures to provide the vdso data pointer

[Thomas Gleixner]

From: Christophe Leroy <christophe.leroy@c-s.fr>

On powerpc, __arch_get_vdso_data() clobbers the link register, requiring
the caller to save it.

As the parent function already has to set a stack frame and saves the link
register before calling the C vdso function, retrieving the vdso data
pointer there is less overhead.

Split out the functional code from the __cvdso.*() interfaces into new
static functions which can either be called from the existing interfaces
with the vdso data pointer supplied via __arch_get_vdso_data() or directly
from ASM code.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/r/abf97996602ef07223fec30c005df78e5ed41b2e.1580399657.git.christophe.leroy@c-s.fr

---
 lib/vdso/gettimeofday.c |   72 +++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 56 insertions(+), 16 deletions(-)

--- a/lib/vdso/gettimeofday.c
+++ b/lib/vdso/gettimeofday.c
@@ -233,9 +233,9 @@ static __always_inline int do_coarse(con
 }
 
 static __maybe_unused int
-__cvdso_clock_gettime_common(clockid_t clock, struct __kernel_timespec *ts)
+__cvdso_clock_gettime_common(const struct vdso_data *vd, clockid_t clock,
+			     struct __kernel_timespec *ts)
 {
-	const struct vdso_data *vd = __arch_get_vdso_data();
 	u32 msk;
 
 	/* Check for negative values or invalid clocks */
@@ -260,23 +260,31 @@ static __maybe_unused int
 }
 
 static __maybe_unused int
-__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
+__cvdso_clock_gettime_data(const struct vdso_data *vd, clockid_t clock,
+			   struct __kernel_timespec *ts)
 {
-	int ret = __cvdso_clock_gettime_common(clock, ts);
+	int ret = __cvdso_clock_gettime_common(vd, clock, ts);
 
 	if (unlikely(ret))
 		return clock_gettime_fallback(clock, ts);
 	return 0;
 }
 
+static __maybe_unused int
+__cvdso_clock_gettime(clockid_t clock, struct __kernel_timespec *ts)
+{
+	return __cvdso_clock_gettime_data(__arch_get_vdso_data(), clock, ts);
+}
+
 #ifdef BUILD_VDSO32
 static __maybe_unused int
-__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
+__cvdso_clock_gettime32_data(const struct vdso_data *vd, clockid_t clock,
+			     struct old_timespec32 *res)
 {
 	struct __kernel_timespec ts;
 	int ret;
 
-	ret = __cvdso_clock_gettime_common(clock, &ts);
+	ret = __cvdso_clock_gettime_common(vd, clock, &ts);
 
 	if (unlikely(ret))
 		return clock_gettime32_fallback(clock, res);
@@ -287,12 +295,18 @@ static __maybe_unused int
 
 	return ret;
 }
+
+static __maybe_unused int
+__cvdso_clock_gettime32(clockid_t clock, struct old_timespec32 *res)
+{
+	return __cvdso_clock_gettime32_data(__arch_get_vdso_data(), clock, res);
+}
 #endif /* BUILD_VDSO32 */
 
 static __maybe_unused int
-__cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
+__cvdso_gettimeofday_data(const struct vdso_data *vd,
+			  struct __kernel_old_timeval *tv, struct timezone *tz)
 {
-	const struct vdso_data *vd = __arch_get_vdso_data();
 
 	if (likely(tv != NULL)) {
 		struct __kernel_timespec ts;
@@ -316,10 +330,16 @@ static __maybe_unused int
 	return 0;
 }
 
+static __maybe_unused int
+__cvdso_gettimeofday(struct __kernel_old_timeval *tv, struct timezone *tz)
+{
+	return __cvdso_gettimeofday_data(__arch_get_vdso_data(), tv, tz);
+}
+
 #ifdef VDSO_HAS_TIME
-static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time)
+static __maybe_unused __kernel_old_time_t
+__cvdso_time_data(const struct vdso_data *vd, __kernel_old_time_t *time)
 {
-	const struct vdso_data *vd = __arch_get_vdso_data();
 	__kernel_old_time_t t;
 
 	if (IS_ENABLED(CONFIG_TIME_NS) &&
@@ -333,13 +353,18 @@ static __maybe_unused __kernel_old_time_
 
 	return t;
 }
+
+static __maybe_unused __kernel_old_time_t __cvdso_time(__kernel_old_time_t *time)
+{
+	return __cvdso_time_data(__arch_get_vdso_data(), time);
+}
 #endif /* VDSO_HAS_TIME */
 
 #ifdef VDSO_HAS_CLOCK_GETRES
 static __maybe_unused
-int __cvdso_clock_getres_common(clockid_t clock, struct __kernel_timespec *res)
+int __cvdso_clock_getres_common(const struct vdso_data *vd, clockid_t clock,
+				struct __kernel_timespec *res)
 {
-	const struct vdso_data *vd = __arch_get_vdso_data();
 	u32 msk;
 	u64 ns;
 
@@ -378,23 +403,31 @@ int __cvdso_clock_getres_common(clockid_
 }
 
 static __maybe_unused
-int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res)
+int __cvdso_clock_getres_data(const struct vdso_data *vd, clockid_t clock,
+			      struct __kernel_timespec *res)
 {
-	int ret = __cvdso_clock_getres_common(clock, res);
+	int ret = __cvdso_clock_getres_common(vd, clock, res);
 
 	if (unlikely(ret))
 		return clock_getres_fallback(clock, res);
 	return 0;
 }
 
+static __maybe_unused
+int __cvdso_clock_getres(clockid_t clock, struct __kernel_timespec *res)
+{
+	return __cvdso_clock_getres_data(__arch_get_vdso_data(), clock, res);
+}
+
 #ifdef BUILD_VDSO32
 static __maybe_unused int
-__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
+__cvdso_clock_getres_time32_data(const struct vdso_data *vd, clockid_t clock,
+				 struct old_timespec32 *res)
 {
 	struct __kernel_timespec ts;
 	int ret;
 
-	ret = __cvdso_clock_getres_common(clock, &ts);
+	ret = __cvdso_clock_getres_common(vd, clock, &ts);
 
 	if (unlikely(ret))
 		return clock_getres32_fallback(clock, res);
@@ -405,5 +438,12 @@ static __maybe_unused int
 	}
 	return ret;
 }
+
+static __maybe_unused int
+__cvdso_clock_getres_time32(clockid_t clock, struct old_timespec32 *res)
+{
+	return __cvdso_clock_getres_time32_data(__arch_get_vdso_data(),
+						clock, res);
+}
 #endif /* BUILD_VDSO32 */
 #endif /* VDSO_HAS_CLOCK_GETRES */

Re: [patch V2 17/17] lib/vdso: Allow architectures to provide the vdso data pointer

[Vincenzo Frascino]

[-- Attachment #1: Type: text/plain, Size: 1036 bytes --]

On 07/02/2020 12:39, Thomas Gleixner wrote:
> From: Christophe Leroy <christophe.leroy@c-s.fr>
> 
> On powerpc, __arch_get_vdso_data() clobbers the link register, requiring
> the caller to save it.
> 
> As the parent function already has to set a stack frame and saves the link
> register before calling the C vdso function, retrieving the vdso data
> pointer there is less overhead.
> 
> Split out the functional code from the __cvdso.*() interfaces into new
> static functions which can either be called from the existing interfaces
> with the vdso data pointer supplied via __arch_get_vdso_data() or directly
> from ASM code.
> 
> Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> Link: https://lore.kernel.org/r/abf97996602ef07223fec30c005df78e5ed41b2e.1580399657.git.christophe.leroy@c-s.fr
> 
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Tested-by: Vincenzo Frascino <vincenzo.frascino@arm.com>

[...]

-- 
Regards,
Vincenzo

[-- Attachment #2: pEpkey.asc --]
[-- Type: application/pgp-keys, Size: 14291 bytes --]