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authorJohannes Berg <johannes@sipsolutions.net>2007-05-03 06:33:51 +1000
committerPaul Mackerras <paulus@samba.org>2007-05-07 20:31:13 +1000
commitd9333afd6a714760c13f76ba275a32ec7bd979c1 (patch)
treeb75cb98ff938edca5aa5254b209d58037e8ec89c /arch/powerpc/kernel/idle_power4.S
parentac18c673e7fa71f62ce613edfe6634edb99f968b (diff)
downloadlinux-d9333afd6a714760c13f76ba275a32ec7bd979c1.tar.gz
[POWERPC] powermac: Support G5 CPU hotplug
This allows "hotplugging" of CPUs on G5 machines. CPUs that are disabled are put into an idle loop with the decrementer frequency set to minimum. To wake them up again we kick them just like when bringing them up. To stop those CPUs from messing with any global state we stop them from entering the timer interrupt. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/idle_power4.S')
-rw-r--r--arch/powerpc/kernel/idle_power4.S21
1 files changed, 21 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/idle_power4.S b/arch/powerpc/kernel/idle_power4.S
index ba3195478600..5328709eeedc 100644
--- a/arch/powerpc/kernel/idle_power4.S
+++ b/arch/powerpc/kernel/idle_power4.S
@@ -53,3 +53,24 @@ END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
isync
b 1b
+_GLOBAL(power4_cpu_offline_powersave)
+ /* Go to NAP now */
+ mfmsr r7
+ rldicl r0,r7,48,1
+ rotldi r0,r0,16
+ mtmsrd r0,1 /* hard-disable interrupts */
+ li r0,1
+ li r6,0
+ stb r0,PACAHARDIRQEN(r13) /* we'll hard-enable shortly */
+ stb r6,PACASOFTIRQEN(r13) /* soft-disable irqs */
+BEGIN_FTR_SECTION
+ DSSALL
+ sync
+END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
+ ori r7,r7,MSR_EE
+ oris r7,r7,MSR_POW@h
+ sync
+ isync
+ mtmsrd r7
+ isync
+ blr