linux/arch/s390/kernel/switch_cpu.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

61 lines
1.3 KiB
ArmAsm

/*
* 31-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:
stm %r6,%r15,__SF_GPRS(%r15)
lr %r1,%r15
ahi %r15,-STACK_FRAME_OVERHEAD
st %r1,__SF_BACKCHAIN(%r15)
basr %r13,0
0: la %r1,.gprregs_addr-0b(%r13)
l %r1,0(%r1)
stm %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:
basr %r13,0
0: la %r1,.gprregs_addr-0b(%r13)
l %r1,0(%r1)
lm %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
ltr %r4,%r4 /* New stack ? */
jz 1f
lr %r15,%r4
1: lr %r14,%r2 /* r14: Function to call */
lr %r2,%r3 /* r2 : Parameter for function*/
basr %r14,%r14 /* Call function */
.gprregs_addr:
.long .gprregs
.section .data,"aw",@progbits
.gprregs:
.rept 16
.long 0
.endr