diff options
Diffstat (limited to 'arch/s390/kernel/vdso64/getcpu.S')
| -rw-r--r-- | arch/s390/kernel/vdso64/getcpu.S | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso64/getcpu.S b/arch/s390/kernel/vdso64/getcpu.S new file mode 100644 index 000000000000..4cbe98291931 --- /dev/null +++ b/arch/s390/kernel/vdso64/getcpu.S @@ -0,0 +1,42 @@ +/* + * 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 |