ARC: SMP support

[karo-tx-linux.git] / arch / arc / kernel / head.S

diff --git a/arch/arc/kernel/head.S b/arch/arc/kernel/head.S
index e63f6a43abb1d786389c11dd419bf9bd1ff2b06b..006dec3fc3534cbbf179e5c0d002d7c3c258a7af 100644 (file)
--- a/arch/arc/kernel/head.S
+++ b/arch/arc/kernel/head.S
@@ -27,6 +27,15 @@ stext:
        ; Don't clobber r0-r4 yet. It might have bootloader provided info
        ;-------------------------------------------------------------------
 
+#ifdef CONFIG_SMP
+       ; Only Boot (Master) proceeds. Others wait in platform dependent way
+       ;       IDENTITY Reg [ 3  2  1  0 ]
+       ;       (cpu-id)             ^^^        => Zero for UP ARC700
+       ;                                       => #Core-ID if SMP (Master 0)
+       GET_CPU_ID  r5
+       cmp     r5, 0
+       jnz     arc_platform_smp_wait_to_boot
+#endif
        ; Clear BSS before updating any globals
        ; XXX: use ZOL here
        mov     r5, __bss_start
@@ -76,3 +85,27 @@ stext:
        GET_TSK_STACK_BASE r9, sp       ; r9 = tsk, sp = stack base(output)
 
        j       start_kernel    ; "C" entry point
+
+#ifdef CONFIG_SMP
+;----------------------------------------------------------------
+;     First lines of code run by secondary before jumping to 'C'
+;----------------------------------------------------------------
+       .section .init.text, "ax",@progbits
+       .type first_lines_of_secondary, @function
+       .globl first_lines_of_secondary
+
+first_lines_of_secondary:
+
+       ; setup per-cpu idle task as "current" on this CPU
+       ld      r0, [@secondary_idle_tsk]
+       SET_CURR_TASK_ON_CPU  r0, r1
+
+       ; setup stack (fp, sp)
+       mov     fp, 0
+
+       ; set it's stack base to tsk->thread_info bottom
+       GET_TSK_STACK_BASE r0, sp
+
+       j       start_kernel_secondary
+
+#endif