This patch selects HAVE_GET_CYCLES and makes sure get_cycles_barrier() and
get_cycles_rate() are implemented.
Signed-off-by: Mathieu Desnoyers <[email protected]>
CC: [email protected]
CC: [email protected]
CC: David Miller <[email protected]>
CC: Linus Torvalds <[email protected]>
CC: Andrew Morton <[email protected]>
CC: Ingo Molnar <[email protected]>
CC: Peter Zijlstra <[email protected]>
CC: Thomas Gleixner <[email protected]>
CC: Steven Rostedt <[email protected]>
CC: [email protected]
---
arch/powerpc/Kconfig | 1 +
arch/powerpc/include/asm/timex.h | 11 +++++++++++
2 files changed, 12 insertions(+)
Index: linux.trees.git/arch/powerpc/Kconfig
===================================================================
--- linux.trees.git.orig/arch/powerpc/Kconfig 2008-11-07 00:09:44.000000000 -0500
+++ linux.trees.git/arch/powerpc/Kconfig 2008-11-07 00:09:46.000000000 -0500
@@ -121,6 +121,7 @@ config PPC
select HAVE_DMA_ATTRS if PPC64
select USE_GENERIC_SMP_HELPERS if SMP
select HAVE_OPROFILE
+ select HAVE_GET_CYCLES if PPC64
config EARLY_PRINTK
bool
Index: linux.trees.git/arch/powerpc/include/asm/timex.h
===================================================================
--- linux.trees.git.orig/arch/powerpc/include/asm/timex.h 2008-11-07 00:09:44.000000000 -0500
+++ linux.trees.git/arch/powerpc/include/asm/timex.h 2008-11-07 00:09:46.000000000 -0500
@@ -7,6 +7,7 @@
* PowerPC architecture timex specifications
*/
+#include <linux/time.h>
#include <asm/cputable.h>
#include <asm/reg.h>
@@ -46,5 +47,15 @@ static inline cycles_t get_cycles(void)
#endif
}
+static inline cycles_t get_cycles_rate(void)
+{
+ return tb_ticks_per_sec;
+}
+
+static inline void get_cycles_barrier(void)
+{
+ isync();
+}
+
#endif /* __KERNEL__ */
#endif /* _ASM_POWERPC_TIMEX_H */
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68
On Fri, Nov 07, 2008 at 12:23:40AM -0500, Mathieu Desnoyers wrote:
>This patch selects HAVE_GET_CYCLES and makes sure get_cycles_barrier() and
>get_cycles_rate() are implemented.
>
>Signed-off-by: Mathieu Desnoyers <[email protected]>
>CC: [email protected]
>CC: [email protected]
>CC: David Miller <[email protected]>
>CC: Linus Torvalds <[email protected]>
>CC: Andrew Morton <[email protected]>
>CC: Ingo Molnar <[email protected]>
>CC: Peter Zijlstra <[email protected]>
>CC: Thomas Gleixner <[email protected]>
>CC: Steven Rostedt <[email protected]>
>CC: [email protected]
>---
> arch/powerpc/Kconfig | 1 +
> arch/powerpc/include/asm/timex.h | 11 +++++++++++
> 2 files changed, 12 insertions(+)
>
>Index: linux.trees.git/arch/powerpc/Kconfig
>===================================================================
>--- linux.trees.git.orig/arch/powerpc/Kconfig 2008-11-07 00:09:44.000000000 -0500
>+++ linux.trees.git/arch/powerpc/Kconfig 2008-11-07 00:09:46.000000000 -0500
>@@ -121,6 +121,7 @@ config PPC
> select HAVE_DMA_ATTRS if PPC64
> select USE_GENERIC_SMP_HELPERS if SMP
> select HAVE_OPROFILE
>+ select HAVE_GET_CYCLES if PPC64
So maybe it's just me because it's Friday and I'm on vacation, but I don't
see anything overly specific to ppc64 here. In fact, you use get_cycles_rate
for all of powerpc in a later patch in the series.
Is there something special about HAVE_GET_CYCLES that I'm missing that would
make it only apply to ppc64 and not ppc32?
josh
* Josh Boyer ([email protected]) wrote:
> On Fri, Nov 07, 2008 at 12:23:40AM -0500, Mathieu Desnoyers wrote:
> >This patch selects HAVE_GET_CYCLES and makes sure get_cycles_barrier() and
> >get_cycles_rate() are implemented.
> >
> >Signed-off-by: Mathieu Desnoyers <[email protected]>
> >CC: [email protected]
> >CC: [email protected]
> >CC: David Miller <[email protected]>
> >CC: Linus Torvalds <[email protected]>
> >CC: Andrew Morton <[email protected]>
> >CC: Ingo Molnar <[email protected]>
> >CC: Peter Zijlstra <[email protected]>
> >CC: Thomas Gleixner <[email protected]>
> >CC: Steven Rostedt <[email protected]>
> >CC: [email protected]
> >---
> > arch/powerpc/Kconfig | 1 +
> > arch/powerpc/include/asm/timex.h | 11 +++++++++++
> > 2 files changed, 12 insertions(+)
> >
> >Index: linux.trees.git/arch/powerpc/Kconfig
> >===================================================================
> >--- linux.trees.git.orig/arch/powerpc/Kconfig 2008-11-07 00:09:44.000000000 -0500
> >+++ linux.trees.git/arch/powerpc/Kconfig 2008-11-07 00:09:46.000000000 -0500
> >@@ -121,6 +121,7 @@ config PPC
> > select HAVE_DMA_ATTRS if PPC64
> > select USE_GENERIC_SMP_HELPERS if SMP
> > select HAVE_OPROFILE
> >+ select HAVE_GET_CYCLES if PPC64
>
> So maybe it's just me because it's Friday and I'm on vacation, but I don't
> see anything overly specific to ppc64 here. In fact, you use get_cycles_rate
> for all of powerpc in a later patch in the series.
>
> Is there something special about HAVE_GET_CYCLES that I'm missing that would
> make it only apply to ppc64 and not ppc32?
>
> josh
Hi Josh,
powerpc32 only uses the 32 LSBs for the TSC in the current get_cycles()
implementation. We could either define HAVE_GET_CYCLES_32 like I did on
mips32, or change get_cycles so it also reads the 32 MSBs in a loop like
this (it does not take care of the CPU_FTR_CELL_TB_BUG though) :
typedef unsigned long long cycles_t;
cycles_t get_cycles_ppc32(void)
{
union {
cycles_t v;
struct {
u32 ms32, ls32; /* powerpc is big endian */
} s;
} cycles;
do {
cycles.ls32 = mftbu();
cycles.ms32 = mftbl();
} while (cycles.ls32 != mftbu());
return cycles.v;
}
I'd prefer this second solution. If one needs a specific get_cycles() to
be only 32-bits (but really really fast) for the scheduler, then this
could be a get_cycles_sched() or something like this which does not
guarantee that it returns full 64-bits...
Mathieu
--
Mathieu Desnoyers
OpenPGP key fingerprint: 8CD5 52C3 8E3C 4140 715F BA06 3F25 A8FE 3BAE 9A68