powerpc: Properly handshake CPUs going out of boot spin loop
We need to wait a bit for them to have done their CPU setup
or we might end up with translation and EE on with different
LPCR values between threads
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 9594427..0700e11 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -242,23 +242,31 @@
ld r23,0(r23)
ld r23,CPU_SPEC_RESTORE(r23)
cmpdi 0,r23,0
- beq 4f
+ beq 3f
ld r23,0(r23)
mtctr r23
bctrl
-3: HMT_LOW
+3: LOAD_REG_ADDR(r3, boot_cpu_count) /* Decrement boot_cpu_count */
+ lwarx r4,0,r3
+ subi r4,r4,1
+ stwcx. r4,0,r3
+ bne 3b
+ isync
+
+4: HMT_LOW
lbz r23,PACAPROCSTART(r13) /* Test if this processor should */
/* start. */
#ifndef CONFIG_SMP
- b 3b /* Never go on non-SMP */
+ b 4b /* Never go on non-SMP */
#else
cmpwi 0,r23,0
- beq 3b /* Loop until told to go */
+ beq 4b /* Loop until told to go */
sync /* order paca.run and cur_cpu_spec */
+ isync /* In case code patching happened */
-4: /* Create a temp kernel stack for use before relocation is on. */
+ /* Create a temp kernel stack for use before relocation is on. */
ld r1,PACAEMERGSP(r13)
subi r1,r1,STACK_FRAME_OVERHEAD
