From: Benjamin Herrenschmidt Date: Tue, 1 Feb 2011 01:13:09 +0000 (+1100) Subject: powerpc: Call CPU ->restore callback earlier on secondary CPUs X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=ad0693ee722b93b63a89c845e99513f242e43aa6;p=linux-beck.git powerpc: Call CPU ->restore callback earlier on secondary CPUs We do it before we loop on the PACA start flag. This way, we get a chance to set critical SPRs on all CPUs before Linux tries to start them up, which avoids problems when changing some bits such as LPCR bits that need to be identical on all threads of a core or similar things like that. Ideally, some of that should also be done before the MMU is enabled, but that's a separate issue which would require moving some of the SMP startup code earlier, let's not get there for now, it works with that change alone. Signed-off-by: Benjamin Herrenschmidt --- diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S index 39a40400f3f2..95944278380c 100644 --- a/arch/powerpc/kernel/head_64.S +++ b/arch/powerpc/kernel/head_64.S @@ -236,17 +236,6 @@ generic_secondary_common_init: /* From now on, r24 is expected to be logical cpuid */ mr r24,r5 -3: HMT_LOW - lbz r23,PACAPROCSTART(r13) /* Test if this processor should */ - /* start. */ - -#ifndef CONFIG_SMP - b 3b /* Never go on non-SMP */ -#else - cmpwi 0,r23,0 - beq 3b /* Loop until told to go */ - - sync /* order paca.run and cur_cpu_spec */ /* See if we need to call a cpu state restore handler */ LOAD_REG_ADDR(r23, cur_cpu_spec) @@ -258,6 +247,17 @@ generic_secondary_common_init: mtctr r23 bctrl +3: HMT_LOW + lbz r23,PACAPROCSTART(r13) /* Test if this processor should */ + /* start. */ +#ifndef CONFIG_SMP + b 3b /* Never go on non-SMP */ +#else + cmpwi 0,r23,0 + beq 3b /* Loop until told to go */ + + sync /* order paca.run and cur_cpu_spec */ + 4: /* Create a temp kernel stack for use before relocation is on. */ ld r1,PACAEMERGSP(r13) subi r1,r1,STACK_FRAME_OVERHEAD