| /* |
| * Userland implementation of clock_gettime() 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) |
| * |
| * 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 |
| basr %r5,0 |
| 0: al %r5,21f-0b(%r5) /* get &_vdso_data */ |
| chi %r2,__CLOCK_REALTIME |
| je 10f |
| chi %r2,__CLOCK_MONOTONIC |
| jne 19f |
| |
| /* CLOCK_MONOTONIC */ |
| ltr %r3,%r3 |
| jz 9f /* tp == NULL */ |
| 1: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ |
| tml %r4,0x0001 /* pending update ? loop */ |
| jnz 1b |
| stck 24(%r15) /* Store TOD clock */ |
| lm %r0,%r1,24(%r15) |
| s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ |
| sl %r1,__VDSO_XTIME_STAMP+4(%r5) |
| brc 3,2f |
| ahi %r0,-1 |
| 2: ms %r0,__VDSO_NTP_MULT(%r5) /* cyc2ns(clock,cycle_delta) */ |
| lr %r2,%r0 |
| l %r0,__VDSO_NTP_MULT(%r5) |
| ltr %r1,%r1 |
| mr %r0,%r0 |
| jnm 3f |
| a %r0,__VDSO_NTP_MULT(%r5) |
| 3: alr %r0,%r2 |
| srdl %r0,12 |
| al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */ |
| al %r1,__VDSO_XTIME_NSEC+4(%r5) |
| brc 12,4f |
| ahi %r0,1 |
| 4: l %r2,__VDSO_XTIME_SEC+4(%r5) |
| al %r0,__VDSO_WTOM_NSEC(%r5) /* + wall_to_monotonic */ |
| al %r1,__VDSO_WTOM_NSEC+4(%r5) |
| brc 12,5f |
| ahi %r0,1 |
| 5: al %r2,__VDSO_WTOM_SEC+4(%r5) |
| cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ |
| jne 1b |
| basr %r5,0 |
| 6: ltr %r0,%r0 |
| jnz 7f |
| cl %r1,20f-6b(%r5) |
| jl 8f |
| 7: ahi %r2,1 |
| sl %r1,20f-6b(%r5) |
| brc 3,6b |
| ahi %r0,-1 |
| j 6b |
| 8: st %r2,0(%r3) /* store tp->tv_sec */ |
| st %r1,4(%r3) /* store tp->tv_nsec */ |
| 9: lhi %r2,0 |
| br %r14 |
| |
| /* CLOCK_REALTIME */ |
| 10: ltr %r3,%r3 /* tp == NULL */ |
| jz 18f |
| 11: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ |
| tml %r4,0x0001 /* pending update ? loop */ |
| jnz 11b |
| stck 24(%r15) /* Store TOD clock */ |
| lm %r0,%r1,24(%r15) |
| s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ |
| sl %r1,__VDSO_XTIME_STAMP+4(%r5) |
| brc 3,12f |
| ahi %r0,-1 |
| 12: ms %r0,__VDSO_NTP_MULT(%r5) /* cyc2ns(clock,cycle_delta) */ |
| lr %r2,%r0 |
| l %r0,__VDSO_NTP_MULT(%r5) |
| ltr %r1,%r1 |
| mr %r0,%r0 |
| jnm 13f |
| a %r0,__VDSO_NTP_MULT(%r5) |
| 13: alr %r0,%r2 |
| srdl %r0,12 |
| al %r0,__VDSO_XTIME_NSEC(%r5) /* + xtime */ |
| al %r1,__VDSO_XTIME_NSEC+4(%r5) |
| brc 12,14f |
| ahi %r0,1 |
| 14: l %r2,__VDSO_XTIME_SEC+4(%r5) |
| cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ |
| jne 11b |
| basr %r5,0 |
| 15: ltr %r0,%r0 |
| jnz 16f |
| cl %r1,20f-15b(%r5) |
| jl 17f |
| 16: ahi %r2,1 |
| sl %r1,20f-15b(%r5) |
| brc 3,15b |
| ahi %r0,-1 |
| j 15b |
| 17: st %r2,0(%r3) /* store tp->tv_sec */ |
| st %r1,4(%r3) /* store tp->tv_nsec */ |
| 18: lhi %r2,0 |
| br %r14 |
| |
| /* Fallback to system call */ |
| 19: lhi %r1,__NR_clock_gettime |
| svc 0 |
| br %r14 |
| |
| 20: .long 1000000000 |
| 21: .long _vdso_data - 0b |
| .cfi_endproc |
| .size __kernel_clock_gettime,.-__kernel_clock_gettime |
