projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| b020632e MS |
1 | /* |
| 2 | * Userland implementation of clock_gettime() for 32 bits processes in a | |
| 3 | * s390 kernel for use in the vDSO | |
| 4 | * | |
| 5 | * Copyright IBM Corp. 2008 | |
| 6 | * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) | |
| 7 | * | |
| 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. | |
| 11 | */ | |
| 12 | #include <asm/vdso.h> | |
| 13 | #include <asm/asm-offsets.h> | |
| 14 | #include <asm/unistd.h> | |
| 15 | ||
| 16 | .text | |
| 17 | .align 4 | |
| 18 | .globl __kernel_clock_gettime | |
| 19 | .type __kernel_clock_gettime,@function | |
| 20 | __kernel_clock_gettime: | |
| 21 | .cfi_startproc | |
| 22 | basr %r5,0 | |
| 23 | 0: al %r5,21f-0b(%r5) /* get &_vdso_data */ | |
| b3423982 | 24 | chi %r2,__CLOCK_REALTIME |
| 5da76157 | 25 | je 11f |
| b3423982 | 26 | chi %r2,__CLOCK_MONOTONIC |
| b020632e MS |
27 | jne 19f |
| 28 | ||
| 29 | /* CLOCK_MONOTONIC */ | |
| b020632e MS |
30 | 1: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ |
| 31 | tml %r4,0x0001 /* pending update ? loop */ | |
| 32 | jnz 1b | |
| 33 | stck 24(%r15) /* Store TOD clock */ | |
| 34 | lm %r0,%r1,24(%r15) | |
| 35 | s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ | |
| 36 | sl %r1,__VDSO_XTIME_STAMP+4(%r5) | |
| 37 | brc 3,2f | |
| 38 | ahi %r0,-1 | |
| 79c74ecb | 39 | 2: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */ |
| b020632e | 40 | lr %r2,%r0 |
| 79c74ecb | 41 | l %r0,__VDSO_TK_MULT(%r5) |
| b020632e MS |
42 | ltr %r1,%r1 |
| 43 | mr %r0,%r0 | |
| 44 | jnm 3f | |
| 79c74ecb | 45 | a %r0,__VDSO_TK_MULT(%r5) |
| b020632e | 46 | 3: alr %r0,%r2 |
| ca5de58b | 47 | al %r0,__VDSO_WTOM_NSEC(%r5) |
| b020632e MS |
48 | al %r1,__VDSO_WTOM_NSEC+4(%r5) |
| 49 | brc 12,5f | |
| 50 | ahi %r0,1 | |
| 79c74ecb MS |
51 | 5: l %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ |
| 52 | srdl %r0,0(%r2) /* >> tk->shift */ | |
| ca5de58b | 53 | l %r2,__VDSO_WTOM_SEC+4(%r5) |
| b020632e MS |
54 | cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ |
| 55 | jne 1b | |
| 56 | basr %r5,0 | |
| 57 | 6: ltr %r0,%r0 | |
| 58 | jnz 7f | |
| 59 | cl %r1,20f-6b(%r5) | |
| 60 | jl 8f | |
| 61 | 7: ahi %r2,1 | |
| 62 | sl %r1,20f-6b(%r5) | |
| 63 | brc 3,6b | |
| 64 | ahi %r0,-1 | |
| 65 | j 6b | |
| 66 | 8: st %r2,0(%r3) /* store tp->tv_sec */ | |
| 67 | st %r1,4(%r3) /* store tp->tv_nsec */ | |
| 5da76157 | 68 | lhi %r2,0 |
| b020632e MS |
69 | br %r14 |
| 70 | ||
| 71 | /* CLOCK_REALTIME */ | |
| b020632e MS |
72 | 11: l %r4,__VDSO_UPD_COUNT+4(%r5) /* load update counter */ |
| 73 | tml %r4,0x0001 /* pending update ? loop */ | |
| 74 | jnz 11b | |
| 75 | stck 24(%r15) /* Store TOD clock */ | |
| 76 | lm %r0,%r1,24(%r15) | |
| 77 | s %r0,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ | |
| 78 | sl %r1,__VDSO_XTIME_STAMP+4(%r5) | |
| 79 | brc 3,12f | |
| 80 | ahi %r0,-1 | |
| 79c74ecb | 81 | 12: ms %r0,__VDSO_TK_MULT(%r5) /* * tk->mult */ |
| b020632e | 82 | lr %r2,%r0 |
| 79c74ecb | 83 | l %r0,__VDSO_TK_MULT(%r5) |
| b020632e MS |
84 | ltr %r1,%r1 |
| 85 | mr %r0,%r0 | |
| 86 | jnm 13f | |
| 79c74ecb | 87 | a %r0,__VDSO_TK_MULT(%r5) |
| b020632e | 88 | 13: alr %r0,%r2 |
| 79c74ecb | 89 | al %r0,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */ |
| b020632e MS |
90 | al %r1,__VDSO_XTIME_NSEC+4(%r5) |
| 91 | brc 12,14f | |
| 92 | ahi %r0,1 | |
| 79c74ecb MS |
93 | 14: l %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ |
| 94 | srdl %r0,0(%r2) /* >> tk->shift */ | |
| 95 | l %r2,__VDSO_XTIME_SEC+4(%r5) | |
| b020632e MS |
96 | cl %r4,__VDSO_UPD_COUNT+4(%r5) /* check update counter */ |
| 97 | jne 11b | |
| 98 | basr %r5,0 | |
| 99 | 15: ltr %r0,%r0 | |
| 100 | jnz 16f | |
| 101 | cl %r1,20f-15b(%r5) | |
| 102 | jl 17f | |
| 103 | 16: ahi %r2,1 | |
| 104 | sl %r1,20f-15b(%r5) | |
| 105 | brc 3,15b | |
| 106 | ahi %r0,-1 | |
| 107 | j 15b | |
| 108 | 17: st %r2,0(%r3) /* store tp->tv_sec */ | |
| 109 | st %r1,4(%r3) /* store tp->tv_nsec */ | |
| 5da76157 | 110 | lhi %r2,0 |
| b020632e MS |
111 | br %r14 |
| 112 | ||
| 113 | /* Fallback to system call */ | |
| 114 | 19: lhi %r1,__NR_clock_gettime | |
| 115 | svc 0 | |
| 116 | br %r14 | |
| 117 | ||
| 118 | 20: .long 1000000000 | |
| 119 | 21: .long _vdso_data - 0b | |
| 120 | .cfi_endproc | |
| 121 | .size __kernel_clock_gettime,.-__kernel_clock_gettime |