2 * Userland implementation of clock_gettime() for 32 bits processes in a
3 * s390 kernel for use in the vDSO
5 * Copyright IBM Corp. 2008
6 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com)
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License (version 2 only)
10 * as published by the Free Software Foundation.
13 #include <asm/asm-offsets.h>
14 #include <asm/unistd.h>
18 .globl __kernel_clock_gettime
19 .type __kernel_clock_gettime,@function
20 __kernel_clock_gettime:
23 0: al %r5,21f-0b(%r5) /* get &_vdso_data */
24 chi %r2,__CLOCK_REALTIME_COARSE
26 chi %r2,__CLOCK_REALTIME
28 chi %r2,__CLOCK_MONOTONIC_COARSE
30 chi %r2,__CLOCK_MONOTONIC
34 1: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
35 tml %r4,0x0001 /* pending update ? loop */
37 stcke 24(%r15) /* Store TOD clock */
39 s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
40 sl %r1,__VDSO_XTIME_STAMP+4(%r5)
43 2: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */
45 l %r0,__VDSO_TK_MULT(%r5)
49 a %r0,__VDSO_TK_MULT(%r5)
51 al %r0,__VDSO_WTOM_NSEC(%r5)
52 al %r1,__VDSO_WTOM_NSEC+4(%r5)
55 5: l %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
56 srdl %r0,0(%r2) /* >> tk->shift */
57 l %r2,__VDSO_WTOM_SEC+4(%r5)
58 cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
70 8: st %r2,0(%r3) /* store tp->tv_sec */
71 st %r1,4(%r3) /* store tp->tv_nsec */
75 /* CLOCK_MONOTONIC_COARSE */
76 9: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
77 tml %r4,0x0001 /* pending update ? loop */
79 l %r2,__VDSO_WTOM_CRS_SEC+4(%r5)
80 l %r1,__VDSO_WTOM_CRS_NSEC+4(%r5)
81 cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
85 /* CLOCK_REALTIME_COARSE */
86 10: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
87 tml %r4,0x0001 /* pending update ? loop */
89 l %r2,__VDSO_XTIME_CRS_SEC+4(%r5)
90 l %r1,__VDSO_XTIME_CRS_NSEC+4(%r5)
91 cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
96 11: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */
97 tml %r4,0x0001 /* pending update ? loop */
99 stcke 24(%r15) /* Store TOD clock */
101 s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */
102 sl %r1,__VDSO_XTIME_STAMP+4(%r5)
105 12: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */
107 l %r0,__VDSO_TK_MULT(%r5)
111 a %r0,__VDSO_TK_MULT(%r5)
113 al %r0,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */
114 al %r1,__VDSO_XTIME_NSEC+4(%r5)
117 14: l %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */
118 srdl %r0,0(%r2) /* >> tk->shift */
119 l %r2,__VDSO_XTIME_SEC+4(%r5)
120 cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */
132 17: st %r2,0(%r3) /* store tp->tv_sec */
133 st %r1,4(%r3) /* store tp->tv_nsec */
137 /* Fallback to system call */
138 19: lhi %r1,__NR_clock_gettime
143 21: .long _vdso_data - 0b
145 .size __kernel_clock_gettime,.-__kernel_clock_gettime