linux/arch/s390/kernel/switch_cpu64.S
Michael Holzheu 034e9e966c [S390] Fix parameter passing for smp_switch_to_cpu()
After the execution has been switched to the destination CPU, the target
function is called with the wrong parameter. According to the C calling
convention on s390, the first parameter should be loaded into register 2.
Currently in smp_restart_cpu() it is stored in register 3. To fix this, we
load the parameter into the correct register 2.

Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2011-04-04 09:43:32 +02:00

54 lines
1.2 KiB
ArmAsm

/*
* 64-bit switch cpu code
*
* Copyright IBM Corp. 2009
*
*/
#include <asm/asm-offsets.h>
#include <asm/ptrace.h>
# smp_switch_to_cpu switches to destination cpu and executes the passed function
# Parameter: %r2 - function to call
# %r3 - function parameter
# %r4 - stack poiner
# %r5 - current cpu
# %r6 - destination cpu
.section .text
.align 4
.globl smp_switch_to_cpu
smp_switch_to_cpu:
stmg %r6,%r15,__SF_GPRS(%r15)
lgr %r1,%r15
aghi %r15,-STACK_FRAME_OVERHEAD
stg %r1,__SF_BACKCHAIN(%r15)
larl %r1,.gprregs
stmg %r0,%r15,0(%r1)
1: sigp %r0,%r6,__SIGP_RESTART /* start destination CPU */
brc 2,1b /* busy, try again */
2: sigp %r0,%r5,__SIGP_STOP /* stop current CPU */
brc 2,2b /* busy, try again */
3: j 3b
.globl smp_restart_cpu
smp_restart_cpu:
larl %r1,.gprregs
lmg %r0,%r15,0(%r1)
1: sigp %r0,%r5,__SIGP_SENSE /* Wait for calling CPU */
brc 10,1b /* busy, accepted (status 0), running */
tmll %r0,0x40 /* Test if calling CPU is stopped */
jz 1b
ltgr %r4,%r4 /* New stack ? */
jz 1f
lgr %r15,%r4
1: lgr %r14,%r2 /* r14: Function to call */
lgr %r2,%r3 /* r2 : Parameter for function*/
basr %r14,%r14 /* Call function */
.section .data,"aw",@progbits
.gprregs:
.rept 16
.quad 0
.endr