path: root/arch/powerpc/kernel
diff options
authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-02-21 16:49:58 +1100
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2011-04-01 15:37:25 +1100
commit62cc67b9df273be18fcb09a071592dedf751c90a (patch)
tree604363a8a8ea577b59c58e10ba7cf36a67ced624 /arch/powerpc/kernel
parente872e41b79f61dbc22f85577613925a4a7de1c1a (diff)
powerpc/pmac/smp: Properly NAP offlined CPU on G5
The current code soft-disables, and then goes to NAP mode which turns interrupts on. That means that if an interrupt occurs, we will hit the masked interrupt code path which isn't what we want, as it will return with EE off, which will either get us out of NAP mode, or fail to enter it (according to spec). Instead, let's just rely on the fact that it is safe to take decrementer interrupts on an offline CPU and leave interrupts enabled. We can also get rid of the special case in asm for power4_cpu_offline_powersave() and just use power4_idle(). Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel')
2 files changed, 7 insertions, 21 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 782f23df7c8..271140b38b6 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -536,6 +536,13 @@ _GLOBAL(pmac_secondary_start)
add r13,r13,r4 /* for this processor. */
mtspr SPRN_SPRG_PACA,r13 /* Save vaddr of paca in an SPRG*/
+ /* Mark interrupts soft and hard disabled (they might be enabled
+ * in the PACA when doing hotplug)
+ */
+ li r0,0
+ stb r0,PACASOFTIRQEN(r13)
+ stb r0,PACAHARDIRQEN(r13)
/* Create a temp kernel stack for use before relocation is on. */
ld r1,PACAEMERGSP(r13)
diff --git a/arch/powerpc/kernel/idle_power4.S b/arch/powerpc/kernel/idle_power4.S
index 5328709eeed..ba319547860 100644
--- a/arch/powerpc/kernel/idle_power4.S
+++ b/arch/powerpc/kernel/idle_power4.S
b 1b
- /* 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 */
- sync
- ori r7,r7,MSR_EE
- oris r7,r7,MSR_POW@h
- sync
- isync
- mtmsrd r7
- isync
- blr