[PATCH 0/3] ARM: context tracking support prerequisites

[PATCH 0/3] ARM: context tracking support prerequisites

[Kevin Hilman]

This series is a set of prerequistes for getting the new context
tracking subsystem, and adaptive tickless support working on ARM.

Kevin Hilman (3):
  cputime_nsecs: use math64.h for nsec resolution conversion helpers
  init/Kconfig: virt CPU accounting: drop 64-bit requirment
  ARM: Kconfig: allow virt CPU accounting

 arch/arm/Kconfig                    |  1 +
 include/asm-generic/cputime_nsecs.h | 28 +++++++++++++++++++---------
 init/Kconfig                        |  2 +-
 3 files changed, 21 insertions(+), 10 deletions(-)

-- 
1.8.2

[PATCH 1/3] cputime_nsecs: use math64.h for nsec resolution conversion helpers

[Kevin Hilman]

For the nsec resolution conversions to be useable on non 64-bit
architectures, the helpers in <linux/math64.h> need to be used so the
right arch-specific 64-bit math helpers can be used (e.g. do_div())

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
---
 include/asm-generic/cputime_nsecs.h | 28 +++++++++++++++++++---------
 1 file changed, 19 insertions(+), 9 deletions(-)

diff --git a/include/asm-generic/cputime_nsecs.h b/include/asm-generic/cputime_nsecs.h
index a8ece9a..2c9e62c 100644
--- a/include/asm-generic/cputime_nsecs.h
+++ b/include/asm-generic/cputime_nsecs.h
@@ -16,21 +16,27 @@
 #ifndef _ASM_GENERIC_CPUTIME_NSECS_H
 #define _ASM_GENERIC_CPUTIME_NSECS_H
 
+#include <linux/math64.h>
+
 typedef u64 __nocast cputime_t;
 typedef u64 __nocast cputime64_t;
 
 #define cputime_one_jiffy		jiffies_to_cputime(1)
 
+#define cputime_div(__ct, divisor)  div_u64((__force u64)__ct, divisor)
+#define cputime_div_rem(__ct, divisor, remainder) \
+	div_u64_rem((__force u64)__ct, divisor, remainder);
+
 /*
  * Convert cputime <-> jiffies (HZ)
  */
 #define cputime_to_jiffies(__ct)	\
-	((__force u64)(__ct) / (NSEC_PER_SEC / HZ))
+	cputime_div(__ct, NSEC_PER_SEC / HZ)
 #define cputime_to_scaled(__ct)		(__ct)
 #define jiffies_to_cputime(__jif)	\
 	(__force cputime_t)((__jif) * (NSEC_PER_SEC / HZ))
 #define cputime64_to_jiffies64(__ct)	\
-	((__force u64)(__ct) / (NSEC_PER_SEC / HZ))
+	cputime_div(__ct, NSEC_PER_SEC / HZ)
 #define jiffies64_to_cputime64(__jif)	\
 	(__force cputime64_t)((__jif) * (NSEC_PER_SEC / HZ))
 
@@ -45,7 +51,7 @@ typedef u64 __nocast cputime64_t;
  * Convert cputime <-> microseconds
  */
 #define cputime_to_usecs(__ct)		\
-	((__force u64)(__ct) / NSEC_PER_USEC)
+	cputime_div(__ct, NSEC_PER_USEC)
 #define usecs_to_cputime(__usecs)	\
 	(__force cputime_t)((__usecs) * NSEC_PER_USEC)
 #define usecs_to_cputime64(__usecs)	\
@@ -55,7 +61,7 @@ typedef u64 __nocast cputime64_t;
  * Convert cputime <-> seconds
  */
 #define cputime_to_secs(__ct)		\
-	((__force u64)(__ct) / NSEC_PER_SEC)
+	cputime_div(__ct, NSEC_PER_SEC)
 #define secs_to_cputime(__secs)		\
 	(__force cputime_t)((__secs) * NSEC_PER_SEC)
 
@@ -69,8 +75,10 @@ static inline cputime_t timespec_to_cputime(const struct timespec *val)
 }
 static inline void cputime_to_timespec(const cputime_t ct, struct timespec *val)
 {
-	val->tv_sec  = (__force u64) ct / NSEC_PER_SEC;
-	val->tv_nsec = (__force u64) ct % NSEC_PER_SEC;
+	u32 rem;
+
+	val->tv_sec = cputime_div_rem(ct, NSEC_PER_SEC, &rem);
+	val->tv_nsec = rem;
 }
 
 /*
@@ -83,15 +91,17 @@ static inline cputime_t timeval_to_cputime(const struct timeval *val)
 }
 static inline void cputime_to_timeval(const cputime_t ct, struct timeval *val)
 {
-	val->tv_sec = (__force u64) ct / NSEC_PER_SEC;
-	val->tv_usec = ((__force u64) ct % NSEC_PER_SEC) / NSEC_PER_USEC;
+	u32 rem;
+
+	val->tv_sec = cputime_div_rem(ct, NSEC_PER_SEC, &rem);
+	val->tv_usec = rem / NSEC_PER_USEC;
 }
 
 /*
  * Convert cputime <-> clock (USER_HZ)
  */
 #define cputime_to_clock_t(__ct)	\
-	((__force u64)(__ct) / (NSEC_PER_SEC / USER_HZ))
+	cputime_div(__ct, (NSEC_PER_SEC / USER_HZ))
 #define clock_t_to_cputime(__x)		\
 	(__force cputime_t)((__x) * (NSEC_PER_SEC / USER_HZ))
 
-- 
1.8.2

[PATCH 2/3] init/Kconfig: virt CPU accounting: drop 64-bit requirment

[Kevin Hilman]

The 64-bit requirement can be removed after the conversion of
the conversion of the nsec granularity cputime to work on !64_BIT

Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Kevin Hilman <khilman@linaro.org>
---
 init/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/init/Kconfig b/init/Kconfig
index 8a1dac2..1f1a328 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -329,7 +329,7 @@ config VIRT_CPU_ACCOUNTING_NATIVE
 
 config VIRT_CPU_ACCOUNTING_GEN
 	bool "Full dynticks CPU time accounting"
-	depends on HAVE_CONTEXT_TRACKING && 64BIT
+	depends on HAVE_CONTEXT_TRACKING
 	select VIRT_CPU_ACCOUNTING
 	select CONTEXT_TRACKING
 	help
-- 
1.8.2

[PATCH 3/3] ARM: Kconfig: allow virt CPU accounting

[Kevin Hilman]

With the 64-bit requirement removed from virt CPU accounting,
allow ARM platforms to enable it.

Signed-off-by: Kevin Hilman <khilman@linaro.org>
---
 arch/arm/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 5b71469..9473d55 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -59,6 +59,7 @@ config ARM
 	select CLONE_BACKWARDS
 	select OLD_SIGSUSPEND3
 	select OLD_SIGACTION
+	select HAVE_VIRT_CPU_ACCOUNTING
 	help
 	  The ARM series is a line of low-power-consumption RISC chip designs
 	  licensed by ARM Ltd and targeted at embedded applications and
-- 
1.8.2

[PATCH 1/3] cputime_nsecs: use math64.h for nsec resolution conversion helpers

[Frederic Weisbecker]

On Wed, Mar 20, 2013 at 04:34:25PM -0700, Kevin Hilman wrote:
> For the nsec resolution conversions to be useable on non 64-bit
> architectures, the helpers in <linux/math64.h> need to be used so the
> right arch-specific 64-bit math helpers can be used (e.g. do_div())
> 
> Cc: Frederic Weisbecker <fweisbec@gmail.com>
> Signed-off-by: Kevin Hilman <khilman@linaro.org>

Ok the patch is nice!

I'm queuing it.

Thanks.

[PATCH 1/3] cputime_nsecs: use math64.h for nsec resolution conversion helpers

[Kevin Hilman]

Frederic Weisbecker <fweisbec@gmail.com> writes:

> On Wed, Mar 20, 2013 at 04:34:25PM -0700, Kevin Hilman wrote:
>> For the nsec resolution conversions to be useable on non 64-bit
>> architectures, the helpers in <linux/math64.h> need to be used so the
>> right arch-specific 64-bit math helpers can be used (e.g. do_div())
>> 
>> Cc: Frederic Weisbecker <fweisbec@gmail.com>
>> Signed-off-by: Kevin Hilman <khilman@linaro.org>
>
> Ok the patch is nice!
>
> I'm queuing it.

Thanks, did you queue PATCH 3/3 also to remove the 64-bit limitation
from VIRT_CPU_ACCOUNTING_GEN:  https://lkml.org/lkml/2013/3/20/656

Kevin

[PATCH 1/3] cputime_nsecs: use math64.h for nsec resolution conversion helpers

[Frederic Weisbecker]

2013/4/15 Kevin Hilman <khilman@linaro.org>:
> Frederic Weisbecker <fweisbec@gmail.com> writes:
>
>> On Wed, Mar 20, 2013 at 04:34:25PM -0700, Kevin Hilman wrote:
>>> For the nsec resolution conversions to be useable on non 64-bit
>>> architectures, the helpers in <linux/math64.h> need to be used so the
>>> right arch-specific 64-bit math helpers can be used (e.g. do_div())
>>>
>>> Cc: Frederic Weisbecker <fweisbec@gmail.com>
>>> Signed-off-by: Kevin Hilman <khilman@linaro.org>
>>
>> Ok the patch is nice!
>>
>> I'm queuing it.
>
> Thanks, did you queue PATCH 3/3 also to remove the 64-bit limitation
> from VIRT_CPU_ACCOUNTING_GEN:  https://lkml.org/lkml/2013/3/20/656

Not yet, for this one I need to deeply check we haven't forgotten
anything concerning cputime_t operations in 32 bits archs.