| Message ID | 1408567315-28479-9-git-send-email-soren.brinkmann@xilinx.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On 08/20/2014 10:41 PM, Soren Brinkmann wrote: > The hotplug code contains only a single function, which is an SMP > function. Move that to platsmp.c where all other SMP runctions reside. > That allows removing hotplug.c and declaring the cpu_die function > static. > > Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> > --- > arch/arm/mach-zynq/Makefile | 1 - > arch/arm/mach-zynq/common.h | 3 +-- > arch/arm/mach-zynq/hotplug.c | 17 ----------------- > arch/arm/mach-zynq/platsmp.c | 18 ++++++++++++++++++ > 4 files changed, 19 insertions(+), 20 deletions(-) > > diff --git a/arch/arm/mach-zynq/Makefile b/arch/arm/mach-zynq/Makefile > index 820dff6e1eba..c85fb3f7d5cd 100644 > --- a/arch/arm/mach-zynq/Makefile > +++ b/arch/arm/mach-zynq/Makefile > @@ -6,5 +6,4 @@ > obj-y := common.o slcr.o pm.o > CFLAGS_REMOVE_hotplug.o =-march=armv6k > CFLAGS_hotplug.o =-Wa,-march=armv7-a -mcpu=cortex-a9 > -obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o > obj-$(CONFIG_SMP) += headsmp.o platsmp.o > diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h > index c0773e87e83c..e6bb12c50a23 100644 > --- a/arch/arm/mach-zynq/common.h > +++ b/arch/arm/mach-zynq/common.h > @@ -39,8 +39,7 @@ extern struct smp_operations zynq_smp_ops __initdata; > > extern void __iomem *zynq_scu_base; > > -/* Hotplug */ > -extern void zynq_platform_cpu_die(unsigned int cpu); > +int zynq_pm_late_init(void); > > int zynq_pm_late_init(void); > > diff --git a/arch/arm/mach-zynq/hotplug.c b/arch/arm/mach-zynq/hotplug.c > index fe44a05677e2..b685c89f11e4 100644 > --- a/arch/arm/mach-zynq/hotplug.c > +++ b/arch/arm/mach-zynq/hotplug.c > @@ -12,20 +12,3 @@ > */ > #include <asm/proc-fns.h> > > -/* > - * platform-specific code to shutdown a CPU > - * > - * Called with IRQs disabled > - */ > -void zynq_platform_cpu_die(unsigned int cpu) > -{ > - zynq_slcr_cpu_state_write(cpu, true); > - > - /* > - * there is no power-control hardware on this platform, so all > - * we can do is put the core into WFI; this is safe as the calling > - * code will have already disabled interrupts > - */ > - for (;;) > - cpu_do_idle(); > -} > diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c > index f77f7ca4c45b..04e578718aa2 100644 > --- a/arch/arm/mach-zynq/platsmp.c > +++ b/arch/arm/mach-zynq/platsmp.c > @@ -132,6 +132,24 @@ static int zynq_cpu_kill(unsigned cpu) > zynq_slcr_cpu_stop(cpu); > return 1; > } > + > +/* > + * platform-specific code to shutdown a CPU > + * > + * Called with IRQs disabled > + */ > +static void zynq_platform_cpu_die(unsigned int cpu) > +{ > + zynq_slcr_cpu_state_write(cpu, true); > + > + /* > + * there is no power-control hardware on this platform, so all > + * we can do is put the core into WFI; this is safe as the calling > + * code will have already disabled interrupts > + */ > + for (;;) > + cpu_do_idle(); IIUC, the cpu_do_idle() will flush the L1 cache and then call the WFI. It makes sense if we are about to power down the core. So I am wondering if we can just call wfi() instead. > +} > #endif > > struct smp_operations zynq_smp_ops __initdata = { >
On Thu, 2014-08-21 at 03:32AM +0200, Daniel Lezcano wrote: > On 08/20/2014 10:41 PM, Soren Brinkmann wrote: > >The hotplug code contains only a single function, which is an SMP > >function. Move that to platsmp.c where all other SMP runctions reside. > >That allows removing hotplug.c and declaring the cpu_die function > >static. > > > >Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> > >--- > > arch/arm/mach-zynq/Makefile | 1 - > > arch/arm/mach-zynq/common.h | 3 +-- > > arch/arm/mach-zynq/hotplug.c | 17 ----------------- > > arch/arm/mach-zynq/platsmp.c | 18 ++++++++++++++++++ > > 4 files changed, 19 insertions(+), 20 deletions(-) > > > >diff --git a/arch/arm/mach-zynq/Makefile b/arch/arm/mach-zynq/Makefile > >index 820dff6e1eba..c85fb3f7d5cd 100644 > >--- a/arch/arm/mach-zynq/Makefile > >+++ b/arch/arm/mach-zynq/Makefile > >@@ -6,5 +6,4 @@ > > obj-y := common.o slcr.o pm.o > > CFLAGS_REMOVE_hotplug.o =-march=armv6k > > CFLAGS_hotplug.o =-Wa,-march=armv7-a -mcpu=cortex-a9 > >-obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o > > obj-$(CONFIG_SMP) += headsmp.o platsmp.o > >diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h > >index c0773e87e83c..e6bb12c50a23 100644 > >--- a/arch/arm/mach-zynq/common.h > >+++ b/arch/arm/mach-zynq/common.h > >@@ -39,8 +39,7 @@ extern struct smp_operations zynq_smp_ops __initdata; > > > > extern void __iomem *zynq_scu_base; > > > >-/* Hotplug */ > >-extern void zynq_platform_cpu_die(unsigned int cpu); > >+int zynq_pm_late_init(void); > > > > int zynq_pm_late_init(void); > > > >diff --git a/arch/arm/mach-zynq/hotplug.c b/arch/arm/mach-zynq/hotplug.c > >index fe44a05677e2..b685c89f11e4 100644 > >--- a/arch/arm/mach-zynq/hotplug.c > >+++ b/arch/arm/mach-zynq/hotplug.c > >@@ -12,20 +12,3 @@ > > */ > > #include <asm/proc-fns.h> > > > >-/* > >- * platform-specific code to shutdown a CPU > >- * > >- * Called with IRQs disabled > >- */ > >-void zynq_platform_cpu_die(unsigned int cpu) > >-{ > >- zynq_slcr_cpu_state_write(cpu, true); > >- > >- /* > >- * there is no power-control hardware on this platform, so all > >- * we can do is put the core into WFI; this is safe as the calling > >- * code will have already disabled interrupts > >- */ > >- for (;;) > >- cpu_do_idle(); > >-} > >diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c > >index f77f7ca4c45b..04e578718aa2 100644 > >--- a/arch/arm/mach-zynq/platsmp.c > >+++ b/arch/arm/mach-zynq/platsmp.c > >@@ -132,6 +132,24 @@ static int zynq_cpu_kill(unsigned cpu) > > zynq_slcr_cpu_stop(cpu); > > return 1; > > } > >+ > >+/* > >+ * platform-specific code to shutdown a CPU > >+ * > >+ * Called with IRQs disabled > >+ */ > >+static void zynq_platform_cpu_die(unsigned int cpu) > >+{ > >+ zynq_slcr_cpu_state_write(cpu, true); > >+ > >+ /* > >+ * there is no power-control hardware on this platform, so all > >+ * we can do is put the core into WFI; this is safe as the calling > >+ * code will have already disabled interrupts > >+ */ > >+ for (;;) > >+ cpu_do_idle(); > > IIUC, the cpu_do_idle() will flush the L1 cache and then call the > WFI. It makes sense if we are about to power down the core. So I am > wondering if we can just call wfi() instead. I'm not sure - it's not that trivial to trace that through the sources. But I think cpu_do_idle ends up in cpu_v7_do_idle which is just: ENTRY(cpu_v7_do_idle) dsb @ WFI may enter a low-power mode wfi ret lr ENDPROC(cpu_v7_do_idle) I think that is what we want here. Thanks, Sören -- To unsubscribe from this list: send the line "unsubscribe linux-pm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/arch/arm/mach-zynq/Makefile b/arch/arm/mach-zynq/Makefile index 820dff6e1eba..c85fb3f7d5cd 100644 --- a/arch/arm/mach-zynq/Makefile +++ b/arch/arm/mach-zynq/Makefile @@ -6,5 +6,4 @@ obj-y := common.o slcr.o pm.o CFLAGS_REMOVE_hotplug.o =-march=armv6k CFLAGS_hotplug.o =-Wa,-march=armv7-a -mcpu=cortex-a9 -obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o obj-$(CONFIG_SMP) += headsmp.o platsmp.o diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h index c0773e87e83c..e6bb12c50a23 100644 --- a/arch/arm/mach-zynq/common.h +++ b/arch/arm/mach-zynq/common.h @@ -39,8 +39,7 @@ extern struct smp_operations zynq_smp_ops __initdata; extern void __iomem *zynq_scu_base; -/* Hotplug */ -extern void zynq_platform_cpu_die(unsigned int cpu); +int zynq_pm_late_init(void); int zynq_pm_late_init(void); diff --git a/arch/arm/mach-zynq/hotplug.c b/arch/arm/mach-zynq/hotplug.c index fe44a05677e2..b685c89f11e4 100644 --- a/arch/arm/mach-zynq/hotplug.c +++ b/arch/arm/mach-zynq/hotplug.c @@ -12,20 +12,3 @@ */ #include <asm/proc-fns.h> -/* - * platform-specific code to shutdown a CPU - * - * Called with IRQs disabled - */ -void zynq_platform_cpu_die(unsigned int cpu) -{ - zynq_slcr_cpu_state_write(cpu, true); - - /* - * there is no power-control hardware on this platform, so all - * we can do is put the core into WFI; this is safe as the calling - * code will have already disabled interrupts - */ - for (;;) - cpu_do_idle(); -} diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c index f77f7ca4c45b..04e578718aa2 100644 --- a/arch/arm/mach-zynq/platsmp.c +++ b/arch/arm/mach-zynq/platsmp.c @@ -132,6 +132,24 @@ static int zynq_cpu_kill(unsigned cpu) zynq_slcr_cpu_stop(cpu); return 1; } + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +static void zynq_platform_cpu_die(unsigned int cpu) +{ + zynq_slcr_cpu_state_write(cpu, true); + + /* + * there is no power-control hardware on this platform, so all + * we can do is put the core into WFI; this is safe as the calling + * code will have already disabled interrupts + */ + for (;;) + cpu_do_idle(); +} #endif struct smp_operations zynq_smp_ops __initdata = {
The hotplug code contains only a single function, which is an SMP function. Move that to platsmp.c where all other SMP runctions reside. That allows removing hotplug.c and declaring the cpu_die function static. Signed-off-by: Soren Brinkmann <soren.brinkmann@xilinx.com> --- arch/arm/mach-zynq/Makefile | 1 - arch/arm/mach-zynq/common.h | 3 +-- arch/arm/mach-zynq/hotplug.c | 17 ----------------- arch/arm/mach-zynq/platsmp.c | 18 ++++++++++++++++++ 4 files changed, 19 insertions(+), 20 deletions(-)