diff options
Diffstat (limited to 'arch/s390/kernel/vdso32/gettimeofday.S')
| -rw-r--r-- | arch/s390/kernel/vdso32/gettimeofday.S | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso32/gettimeofday.S b/arch/s390/kernel/vdso32/gettimeofday.S new file mode 100644 index 000000000..b23063fbc --- /dev/null +++ b/arch/s390/kernel/vdso32/gettimeofday.S @@ -0,0 +1,103 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Userland implementation of gettimeofday() for 32 bits processes in a + * s390 kernel for use in the vDSO + * + * Copyright IBM Corp. 2008 + * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) + */ +#include <asm/vdso.h> +#include <asm/asm-offsets.h> +#include <asm/unistd.h> +#include <asm/dwarf.h> +#include <asm/ptrace.h> + + .text + .align 4 + .globl __kernel_gettimeofday + .type __kernel_gettimeofday,@function +__kernel_gettimeofday: + CFI_STARTPROC + ahi %r15,-16 + CFI_ADJUST_CFA_OFFSET 16 + CFI_VAL_OFFSET 15, -STACK_FRAME_OVERHEAD + basr %r5,0 +0: al %r5,13f-0b(%r5) /* get &_vdso_data */ +1: ltr %r3,%r3 /* check if tz is NULL */ + je 2f + mvc 0(8,%r3),__VDSO_TIMEZONE(%r5) +2: ltr %r2,%r2 /* check if tv is NULL */ + je 10f + l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ + tml %r4,0x0001 /* pending update ? loop */ + jnz 1b + stcke 0(%r15) /* Store TOD clock */ + lm %r0,%r1,__VDSO_TS_END(%r5) /* TOD steering end time */ + s %r0,1(%r15) + sl %r1,5(%r15) + brc 3,14f + ahi %r0,-1 +14: ltr %r0,%r0 /* past end of steering? */ + jm 16f + srdl %r0,15 /* 1 per 2^16 */ + tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ + jz 15f + lcr %r0,%r0 /* negative TOD offset */ + lcr %r1,%r1 + je 15f + ahi %r0,-1 +15: a %r0,1(%r15) /* add TOD timestamp */ + al %r1,5(%r15) + brc 12,17f + ahi %r0,1 + j 17f +16: lm %r0,%r1,1(%r15) /* load TOD timestamp */ +17: s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ + sl %r1,__VDSO_XTIME_STAMP+4(%r5) + brc 3,3f + ahi %r0,-1 +3: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */ + st %r0,0(%r15) + l %r0,__VDSO_TK_MULT(%r5) + ltr %r1,%r1 + mr %r0,%r0 + jnm 4f + a %r0,__VDSO_TK_MULT(%r5) +4: al %r0,0(%r15) + al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */ + al %r1,__VDSO_XTIME_NSEC+4(%r5) + brc 12,5f + ahi %r0,1 +5: mvc 0(4,%r15),__VDSO_XTIME_SEC+4(%r5) + cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ + jne 1b + l %r4,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ + srdl %r0,0(%r4) /* >> tk->shift */ + l %r4,0(%r15) /* get tv_sec from stack */ + basr %r5,0 +6: ltr %r0,%r0 + jnz 7f + cl %r1,11f-6b(%r5) + jl 8f +7: ahi %r4,1 + sl %r1,11f-6b(%r5) + brc 3,6b + ahi %r0,-1 + j 6b +8: st %r4,0(%r2) /* store tv->tv_sec */ + ltr %r1,%r1 + m %r0,12f-6b(%r5) + jnm 9f + al %r0,12f-6b(%r5) +9: srl %r0,6 + st %r0,4(%r2) /* store tv->tv_usec */ +10: slr %r2,%r2 + ahi %r15,16 + CFI_ADJUST_CFA_OFFSET -16 + CFI_RESTORE 15 + br %r14 + CFI_ENDPROC +11: .long 1000000000 +12: .long 274877907 +13: .long _vdso_data - 0b + .size __kernel_gettimeofday,.-__kernel_gettimeofday |