linux-sg2042/arch/s390/kernel/switch_cpu.S

59 lines
1.3 KiB
ArmAsm

/*
* 31-bit switch cpu code
*
* Copyright IBM Corp. 2009
*
*/
#include <linux/linkage.h>
#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
ENTRY(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
ENTRY(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