powerpc: Properly handshake CPUs going out of boot spin loop

[pandora-kernel.git] / arch / powerpc / kernel / head_64.S

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 9594427..0700e11 100644 (file)
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -242,23 +242,31 @@ generic_secondary_common_init:
        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