ARM: CPU hotplug: fix hard-coded control register constants

On Fri, Jan 14, 2011 at 05:20:03PM +0530, viresh kumar wrote:

quoted

diff --git a/arch/arm/mach-s5pv310/hotplug.c b/arch/arm/mach-s5pv310/hotplug.c
index 951ba6d..afa5392 100644
--- a/arch/arm/mach-s5pv310/hotplug.c
+++ b/arch/arm/mach-s5pv310/hotplug.c

@@ -30,13 +30,13 @@ static inline void cpu_enter_lowpower(void)
 	 * Turn off coherency
 	 */
 	"	mrc	p15, 0, %0, c1, c0, 1\n"
-	"	bic	%0, %0, #0x20\n"
+	"	bic	%0, %0, %2\n"

but why replace 0x20 with CR_C instead of CR_D

Looks like a mistake - it should've been the one below.

quoted

 	"	mcr	p15, 0, %0, c1, c0, 1\n"
 	"	mrc	p15, 0, %0, c1, c0, 0\n"
 	"	bic	%0, %0, #0x04\n"
 	"	mcr	p15, 0, %0, c1, c0, 0\n"
 	  : "=&r" (v)
-	  : "r" (0)
+	  : "r" (0), "Ir" (CR_C)
 	  : "cc");

In any case, this code is probably doing the wrong thing - if s5pv310
is not an ARMv6 MPCore the its fiddling with the auxillary control
register is already broken.

quoted

diff --git a/arch/arm/mach-tegra/hotplug.c b/arch/arm/mach-tegra/hotplug.c
index 17faf77..a5cb1ce 100644
--- a/arch/arm/mach-tegra/hotplug.c
+++ b/arch/arm/mach-tegra/hotplug.c

@@ -26,13 +26,13 @@ static inline void cpu_enter_lowpower(void)
 	 * Turn off coherency
 	 */
 	"	mrc	p15, 0, %0, c1, c0, 1\n"
-	"	bic	%0, %0, #0x20\n"
+	"	bic	%0, %0, %2\n"

here also.

Same comment.