[PATCH 0/5] Convert ARM subarchitectures to generic wfi macro.

[PATCH 0/5] Convert ARM subarchitectures to generic wfi macro.

[Nick Bowler]

This series cleans up all remaining ARM subarchitectures that I could
find to use the generic wfi macro.  As I don't have any of the boards in
question, I've only compile-tested these patches to the extent that I
was able.

See the previous discussion in https://lkml.org/lkml/2011/8/19/433 for
more background.

Nick Bowler (5):
  ARM: realview: Use wfi macro in platform_do_lowpower.
  ARM: exynos4: Use wfi macro in platform_do_lowpower.
  ARM: shmobile: Use wfi macro in platform_cpu_die.
  ARM: tegra: Use wfi macro in platform_do_lowpower.
  ARM: omap4: Kill private do_wfi macro.

 arch/arm/mach-exynos4/hotplug.c                 |    9 ++-------
 arch/arm/mach-omap2/include/mach/omap4-common.h |   11 -----------
 arch/arm/mach-omap2/omap-hotplug.c              |    7 +++----
 arch/arm/mach-omap2/pm44xx.c                    |    4 +++-
 arch/arm/mach-realview/hotplug.c                |    9 ++-------
 arch/arm/mach-shmobile/hotplug.c                |   10 +++-------
 arch/arm/mach-tegra/hotplug.c                   |    9 ++-------
 7 files changed, 15 insertions(+), 44 deletions(-)

-- 
1.7.3.4

[PATCH 3/5] ARM: shmobile: Use wfi macro in platform_cpu_die.

[Nick Bowler]

Current Shmobile CPU hotplug code includes a hardcoded WFI instruction,
in ARM encoding.  The hardcoded instruction is both hard to understand
and doomed to failure when building the kernel in Thumb-2 mode.

Signed-off-by: Nick Bowler <nbowler@elliptictech.com>
---
Compile tested in both ARM and Thumb-2 mode, and the resulting hotplug.o
contains the correct instruction sequence, but the final kernel failed
to link for apparently unrelated reasons:

In ARM mode:

    LD      .tmp_vmlinux1
  arch/arm/kernel/built-in.o: In function `twd_timer_setup':
  io.c:(.cpuinit.text+0x600): undefined reference to `gic_enable_ppi'
  arch/arm/mach-shmobile/built-in.o: In function `smp_init_cpus':
  pfc-sh7372.c:(.init.text+0xbb0): undefined reference to `gic_raise_softirq'

In Thumb-2 mode:

    LD      .tmp_vmlinux1
  arch/arm/kernel/built-in.o: In function `get_wchan':
  io.c:(.text+0x1542): undefined reference to `unwind_frame'
  arch/arm/kernel/built-in.o: In function `walk_stackframe':
  io.c:(.text+0x27f0): undefined reference to `unwind_frame'
  arch/arm/kernel/built-in.o: In function `profile_pc':
  io.c:(.text+0x2828): undefined reference to `unwind_frame'
  arch/arm/kernel/built-in.o: In function `twd_timer_setup':
  io.c:(.cpuinit.text+0x42e): undefined reference to `gic_enable_ppi'
  arch/arm/mach-shmobile/built-in.o: In function `smp_init_cpus':
  pfc-sh7372.c:(.init.text+0x8e8): undefined reference to `gic_raise_softirq'
---
 arch/arm/mach-shmobile/hotplug.c |   10 +++-------
 1 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/arch/arm/mach-shmobile/hotplug.c b/arch/arm/mach-shmobile/hotplug.c
index 238a0d9..1e83087 100644
--- a/arch/arm/mach-shmobile/hotplug.c
+++ b/arch/arm/mach-shmobile/hotplug.c
@@ -13,6 +13,8 @@
 #include <linux/errno.h>
 #include <linux/smp.h>
 
+#include <asm/system.h>
+
 int platform_cpu_kill(unsigned int cpu)
 {
 	return 1;
@@ -21,13 +23,7 @@ int platform_cpu_kill(unsigned int cpu)
 void platform_cpu_die(unsigned int cpu)
 {
 	while (1) {
-		/*
-		 * here's the WFI
-		 */
-		asm(".word	0xe320f003\n"
-		    :
-		    :
-		    : "memory", "cc");
+		wfi();
 	}
 }
 
-- 
1.7.3.4

Re: [PATCH 0/5] Convert ARM subarchitectures to generic wfi macro.

[Nick Bowler]

And after all that, I forgot to CC Russell on these patches.  Oops.

On 2011-09-09 11:26 -0400, Nick Bowler wrote:
> This series cleans up all remaining ARM subarchitectures that I could
> find to use the generic wfi macro.  As I don't have any of the boards in
> question, I've only compile-tested these patches to the extent that I
> was able.
> 
> See the previous discussion in https://lkml.org/lkml/2011/8/19/433 for
> more background.
> 
> Nick Bowler (5):
>   ARM: realview: Use wfi macro in platform_do_lowpower.
>   ARM: exynos4: Use wfi macro in platform_do_lowpower.
>   ARM: shmobile: Use wfi macro in platform_cpu_die.
>   ARM: tegra: Use wfi macro in platform_do_lowpower.
>   ARM: omap4: Kill private do_wfi macro.
> 
>  arch/arm/mach-exynos4/hotplug.c                 |    9 ++-------
>  arch/arm/mach-omap2/include/mach/omap4-common.h |   11 -----------
>  arch/arm/mach-omap2/omap-hotplug.c              |    7 +++----
>  arch/arm/mach-omap2/pm44xx.c                    |    4 +++-
>  arch/arm/mach-realview/hotplug.c                |    9 ++-------
>  arch/arm/mach-shmobile/hotplug.c                |   10 +++-------
>  arch/arm/mach-tegra/hotplug.c                   |    9 ++-------
>  7 files changed, 15 insertions(+), 44 deletions(-)

-- 
Nick Bowler, Elliptic Technologies (http://www.elliptictech.com/)

Re: [PATCH 0/5] Convert ARM subarchitectures to generic wfi macro.

[Russell King - ARM Linux]

On Fri, Sep 09, 2011 at 11:42:54AM -0400, Nick Bowler wrote:
> And after all that, I forgot to CC Russell on these patches.  Oops.

Doesn't matter, I get them anyway (provided lakml is in the cc).