1/*
 2 * 64-bit switch cpu code
 3 *
 4 * Copyright IBM Corp. 2009
 5 *
 6 */
 7
 8#include <linux/linkage.h>
 9#include <asm/asm-offsets.h>
10#include <asm/ptrace.h>
11
12# smp_switch_to_cpu switches to destination cpu and executes the passed function
13# Parameter: %r2 - function to call
14#	     %r3 - function parameter
15#	     %r4 - stack poiner
16#	     %r5 - current cpu
17#	     %r6 - destination cpu
18
19	.section .text
20ENTRY(smp_switch_to_cpu)
21	stmg	%r6,%r15,__SF_GPRS(%r15)
22	lgr	%r1,%r15
23	aghi	%r15,-STACK_FRAME_OVERHEAD
24	stg	%r1,__SF_BACKCHAIN(%r15)
25	larl	%r1,.gprregs
26	stmg	%r0,%r15,0(%r1)
271:	sigp	%r0,%r6,__SIGP_RESTART	/* start destination CPU */
28	brc	2,1b			/* busy, try again */
292:	sigp	%r0,%r5,__SIGP_STOP	/* stop current CPU */
30	brc	2,2b			/* busy, try again */
313:	j	3b
32
33ENTRY(smp_restart_cpu)
34	larl	%r1,.gprregs
35	lmg	%r0,%r15,0(%r1)
361:	sigp	%r0,%r5,__SIGP_SENSE	/* Wait for calling CPU */
37	brc	10,1b			/* busy, accepted (status 0), running */
38	tmll	%r0,0x40		/* Test if calling CPU is stopped */
39	jz	1b
40	ltgr	%r4,%r4			/* New stack ? */
41	jz	1f
42	lgr	%r15,%r4
431:	lgr	%r14,%r2		/* r14: Function to call */
44	lgr	%r2,%r3			/* r2 : Parameter for function*/
45	basr	%r14,%r14		/* Call function */
46
47	.section .data,"aw",@progbits
48.gprregs:
49	.rept	16
50	.quad	0
51	.endr