diff options
Diffstat (limited to 'arch/s390/kernel/vdso64/clock_gettime.S')
| -rw-r--r-- | arch/s390/kernel/vdso64/clock_gettime.S | 89 |
1 files changed, 89 insertions, 0 deletions
diff --git a/arch/s390/kernel/vdso64/clock_gettime.S b/arch/s390/kernel/vdso64/clock_gettime.S new file mode 100644 index 00000000000..738a410b7eb --- /dev/null +++ b/arch/s390/kernel/vdso64/clock_gettime.S @@ -0,0 +1,89 @@ +/* + * Userland implementation of clock_gettime() for 64 bits processes in a + * s390 kernel for use in the vDSO + * + * Copyright IBM Corp. 2008 + * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License (version 2 only) + * as published by the Free Software Foundation. + */ +#include <asm/vdso.h> +#include <asm/asm-offsets.h> +#include <asm/unistd.h> + + .text + .align 4 + .globl __kernel_clock_gettime + .type __kernel_clock_gettime,@function +__kernel_clock_gettime: + .cfi_startproc + larl %r5,_vdso_data + cghi %r2,CLOCK_REALTIME + je 4f + cghi %r2,CLOCK_MONOTONIC + jne 9f + + /* CLOCK_MONOTONIC */ + ltgr %r3,%r3 + jz 3f /* tp == NULL */ +0: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ + tmll %r4,0x0001 /* pending update ? loop */ + jnz 0b + stck 48(%r15) /* Store TOD clock */ + lg %r1,48(%r15) + sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ + mghi %r1,1000 + srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */ + alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */ + lg %r0,__VDSO_XTIME_SEC(%r5) + alg %r1,__VDSO_WTOM_NSEC(%r5) /* + wall_to_monotonic */ + alg %r0,__VDSO_WTOM_SEC(%r5) + clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ + jne 0b + larl %r5,10f +1: clg %r1,0(%r5) + jl 2f + slg %r1,0(%r5) + aghi %r0,1 + j 1b +2: stg %r0,0(%r3) /* store tp->tv_sec */ + stg %r1,8(%r3) /* store tp->tv_nsec */ +3: lghi %r2,0 + br %r14 + + /* CLOCK_REALTIME */ +4: ltr %r3,%r3 /* tp == NULL */ + jz 8f +5: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ + tmll %r4,0x0001 /* pending update ? loop */ + jnz 5b + stck 48(%r15) /* Store TOD clock */ + lg %r1,48(%r15) + sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ + mghi %r1,1000 + srlg %r1,%r1,12 /* cyc2ns(clock,cycle_delta) */ + alg %r1,__VDSO_XTIME_NSEC(%r5) /* + xtime */ + lg %r0,__VDSO_XTIME_SEC(%r5) + clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ + jne 5b + larl %r5,10f +6: clg %r1,0(%r5) + jl 7f + slg %r1,0(%r5) + aghi %r0,1 + j 6b +7: stg %r0,0(%r3) /* store tp->tv_sec */ + stg %r1,8(%r3) /* store tp->tv_nsec */ +8: lghi %r2,0 + br %r14 + + /* Fallback to system call */ +9: lghi %r1,__NR_clock_gettime + svc 0 + br %r14 + +10: .quad 1000000000 + .cfi_endproc + .size __kernel_clock_gettime,.-__kernel_clock_gettime |