blob: 4cbe98291931402766f3fe3ff49e3d0bbee82eb9 [file] [log] [blame]
/*
* Userland implementation of getcpu() for 64 bits processes in a
* s390 kernel for use in the vDSO
*
* Copyright IBM Corp. 2016
* Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
*/
#include <asm/vdso.h>
#include <asm/asm-offsets.h>
.text
.align 4
.globl __kernel_getcpu
.type __kernel_getcpu,@function
__kernel_getcpu:
.cfi_startproc
ear %r1,%a4
llilh %r4,0x0100
sar %a4,%r4
la %r4,0
epsw %r0,0
sacf 512
l %r5,__VDSO_CPU_NR(%r4)
l %r4,__VDSO_NODE_ID(%r4)
tml %r0,0x4000
jo 1f
tml %r0,0x8000
jno 0f
sacf 256
j 1f
0: sacf 0
1: sar %a4,%r1
ltgr %r2,%r2
jz 2f
st %r5,0(%r2)
2: ltgr %r3,%r3
jz 3f
st %r4,0(%r3)
3: lghi %r2,0
br %r14
.cfi_endproc
.size __kernel_getcpu,.-__kernel_getcpu