1/* SPDX-License-Identifier: GPL-2.0 */ 2/* 3 * Userland implementation of clock_gettime() for 64 bits processes in a 4 * s390 kernel for use in the vDSO 5 * 6 * Copyright IBM Corp. 2008 7 * Author(s): Martin Schwidefsky (schwidefsky@de.ibm.com) 8 */ 9#include <asm/vdso.h> 10#include <asm/asm-offsets.h> 11#include <asm/unistd.h> 12#include <asm/dwarf.h> 13 14 .text 15 .align 4 16 .globl __kernel_clock_gettime 17 .type __kernel_clock_gettime,@function 18__kernel_clock_gettime: 19 CFI_STARTPROC 20 aghi %r15,-16 21 CFI_DEF_CFA_OFFSET 176 22 CFI_VAL_OFFSET 15, -160 23 larl %r5,_vdso_data 24 cghi %r2,__CLOCK_REALTIME_COARSE 25 je 4f 26 cghi %r2,__CLOCK_REALTIME 27 je 5f 28 cghi %r2,-3 /* Per-thread CPUCLOCK with PID=0, VIRT=1 */ 29 je 9f 30 cghi %r2,__CLOCK_MONOTONIC_COARSE 31 je 3f 32 cghi %r2,__CLOCK_MONOTONIC 33 jne 12f 34 35 /* CLOCK_MONOTONIC */ 360: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ 37 tmll %r4,0x0001 /* pending update ? loop */ 38 jnz 0b 39 stcke 0(%r15) /* Store TOD clock */ 40 lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ 41 lg %r0,__VDSO_WTOM_SEC(%r5) 42 lg %r1,1(%r15) 43 sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ 44 msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */ 45 alg %r1,__VDSO_WTOM_NSEC(%r5) 46 srlg %r1,%r1,0(%r2) /* >> tk->shift */ 47 clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ 48 jne 0b 49 larl %r5,13f 501: clg %r1,0(%r5) 51 jl 2f 52 slg %r1,0(%r5) 53 aghi %r0,1 54 j 1b 552: stg %r0,0(%r3) /* store tp->tv_sec */ 56 stg %r1,8(%r3) /* store tp->tv_nsec */ 57 lghi %r2,0 58 aghi %r15,16 59 CFI_DEF_CFA_OFFSET 160 60 CFI_RESTORE 15 61 br %r14 62 63 /* CLOCK_MONOTONIC_COARSE */ 64 CFI_DEF_CFA_OFFSET 176 65 CFI_VAL_OFFSET 15, -160 663: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ 67 tmll %r4,0x0001 /* pending update ? loop */ 68 jnz 3b 69 lg %r0,__VDSO_WTOM_CRS_SEC(%r5) 70 lg %r1,__VDSO_WTOM_CRS_NSEC(%r5) 71 clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ 72 jne 3b 73 j 2b 74 75 /* CLOCK_REALTIME_COARSE */ 764: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ 77 tmll %r4,0x0001 /* pending update ? loop */ 78 jnz 4b 79 lg %r0,__VDSO_XTIME_CRS_SEC(%r5) 80 lg %r1,__VDSO_XTIME_CRS_NSEC(%r5) 81 clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ 82 jne 4b 83 j 7f 84 85 /* CLOCK_REALTIME */ 865: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ 87 tmll %r4,0x0001 /* pending update ? loop */ 88 jnz 5b 89 stcke 0(%r15) /* Store TOD clock */ 90 lg %r1,1(%r15) 91 lg %r0,__VDSO_TS_END(%r5) /* TOD steering end time */ 92 slgr %r0,%r1 /* now - ts_steering_end */ 93 ltgr %r0,%r0 /* past end of steering ? */ 94 jm 17f 95 srlg %r0,%r0,15 /* 1 per 2^16 */ 96 tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ 97 jz 18f 98 lcgr %r0,%r0 /* negative TOD offset */ 9918: algr %r1,%r0 /* add steering offset */ 10017: lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ 101 sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ 102 msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */ 103 alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */ 104 srlg %r1,%r1,0(%r2) /* >> tk->shift */ 105 lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */ 106 clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ 107 jne 5b 108 larl %r5,13f 1096: clg %r1,0(%r5) 110 jl 7f 111 slg %r1,0(%r5) 112 aghi %r0,1 113 j 6b 1147: stg %r0,0(%r3) /* store tp->tv_sec */ 115 stg %r1,8(%r3) /* store tp->tv_nsec */ 116 lghi %r2,0 117 aghi %r15,16 118 CFI_DEF_CFA_OFFSET 160 119 CFI_RESTORE 15 120 br %r14 121 122 /* CPUCLOCK_VIRT for this thread */ 123 CFI_DEF_CFA_OFFSET 176 124 CFI_VAL_OFFSET 15, -160 1259: lghi %r4,0 126 icm %r0,15,__VDSO_ECTG_OK(%r5) 127 jz 12f 128 sacf 256 /* Magic ectg instruction */ 129 .insn ssf,0xc80100000000,__VDSO_ECTG_BASE(4),__VDSO_ECTG_USER(4),4 130 sacf 0 131 algr %r1,%r0 /* r1 = cputime as TOD value */ 132 mghi %r1,1000 /* convert to nanoseconds */ 133 srlg %r1,%r1,12 /* r1 = cputime in nanosec */ 134 lgr %r4,%r1 135 larl %r5,13f 136 srlg %r1,%r1,9 /* divide by 1000000000 */ 137 mlg %r0,8(%r5) 138 srlg %r0,%r0,11 /* r0 = tv_sec */ 139 stg %r0,0(%r3) 140 msg %r0,0(%r5) /* calculate tv_nsec */ 141 slgr %r4,%r0 /* r4 = tv_nsec */ 142 stg %r4,8(%r3) 143 lghi %r2,0 144 aghi %r15,16 145 CFI_DEF_CFA_OFFSET 160 146 CFI_RESTORE 15 147 br %r14 148 149 /* Fallback to system call */ 150 CFI_DEF_CFA_OFFSET 176 151 CFI_VAL_OFFSET 15, -160 15212: lghi %r1,__NR_clock_gettime 153 svc 0 154 aghi %r15,16 155 CFI_DEF_CFA_OFFSET 160 156 CFI_RESTORE 15 157 br %r14 158 CFI_ENDPROC 159 16013: .quad 1000000000 16114: .quad 19342813113834067 162 .size __kernel_clock_gettime,.-__kernel_clock_gettime 163
