| /* |
| * 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 |
| aghi %r15,-16 |
| larl %r5,_vdso_data |
| cghi %r2,__CLOCK_REALTIME_COARSE |
| je 4f |
| cghi %r2,__CLOCK_REALTIME |
| je 5f |
| cghi %r2,-3 /* Per-thread CPUCLOCK with PID=0, VIRT=1 */ |
| je 9f |
| cghi %r2,__CLOCK_MONOTONIC_COARSE |
| je 3f |
| cghi %r2,__CLOCK_MONOTONIC |
| jne 12f |
| |
| /* CLOCK_MONOTONIC */ |
| 0: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ |
| tmll %r4,0x0001 /* pending update ? loop */ |
| jnz 0b |
| stcke 0(%r15) /* Store TOD clock */ |
| lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ |
| lg %r0,__VDSO_WTOM_SEC(%r5) |
| lg %r1,1(%r15) |
| sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ |
| msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */ |
| alg %r1,__VDSO_WTOM_NSEC(%r5) |
| srlg %r1,%r1,0(%r2) /* >> tk->shift */ |
| clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ |
| jne 0b |
| larl %r5,13f |
| 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 */ |
| lghi %r2,0 |
| aghi %r15,16 |
| br %r14 |
| |
| /* CLOCK_MONOTONIC_COARSE */ |
| 3: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ |
| tmll %r4,0x0001 /* pending update ? loop */ |
| jnz 3b |
| lg %r0,__VDSO_WTOM_CRS_SEC(%r5) |
| lg %r1,__VDSO_WTOM_CRS_NSEC(%r5) |
| clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ |
| jne 3b |
| j 2b |
| |
| /* CLOCK_REALTIME_COARSE */ |
| 4: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ |
| tmll %r4,0x0001 /* pending update ? loop */ |
| jnz 4b |
| lg %r0,__VDSO_XTIME_CRS_SEC(%r5) |
| lg %r1,__VDSO_XTIME_CRS_NSEC(%r5) |
| clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ |
| jne 4b |
| j 7f |
| |
| /* CLOCK_REALTIME */ |
| 5: lg %r4,__VDSO_UPD_COUNT(%r5) /* load update counter */ |
| tmll %r4,0x0001 /* pending update ? loop */ |
| jnz 5b |
| stcke 0(%r15) /* Store TOD clock */ |
| lg %r1,1(%r15) |
| lg %r0,__VDSO_TS_END(%r5) /* TOD steering end time */ |
| slgr %r0,%r1 /* now - ts_steering_end */ |
| ltgr %r0,%r0 /* past end of steering ? */ |
| jm 17f |
| srlg %r0,%r0,15 /* 1 per 2^16 */ |
| tm __VDSO_TS_DIR+3(%r5),0x01 /* steering direction? */ |
| jz 18f |
| lcgr %r0,%r0 /* negative TOD offset */ |
| 18: algr %r1,%r0 /* add steering offset */ |
| 17: lgf %r2,__VDSO_TK_SHIFT(%r5) /* Timekeeper shift */ |
| sg %r1,__VDSO_XTIME_STAMP(%r5) /* TOD - cycle_last */ |
| msgf %r1,__VDSO_TK_MULT(%r5) /* * tk->mult */ |
| alg %r1,__VDSO_XTIME_NSEC(%r5) /* + tk->xtime_nsec */ |
| srlg %r1,%r1,0(%r2) /* >> tk->shift */ |
| lg %r0,__VDSO_XTIME_SEC(%r5) /* tk->xtime_sec */ |
| clg %r4,__VDSO_UPD_COUNT(%r5) /* check update counter */ |
| jne 5b |
| larl %r5,13f |
| 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 */ |
| lghi %r2,0 |
| aghi %r15,16 |
| br %r14 |
| |
| /* CPUCLOCK_VIRT for this thread */ |
| 9: icm %r0,15,__VDSO_ECTG_OK(%r5) |
| jz 12f |
| ear %r2,%a4 |
| llilh %r4,0x0100 |
| sar %a4,%r4 |
| lghi %r4,0 |
| epsw %r5,0 |
| sacf 512 /* Magic ectg instruction */ |
| .insn ssf,0xc80100000000,__VDSO_ECTG_BASE(4),__VDSO_ECTG_USER(4),4 |
| tml %r5,0x4000 |
| jo 11f |
| tml %r5,0x8000 |
| jno 10f |
| sacf 256 |
| j 11f |
| 10: sacf 0 |
| 11: sar %a4,%r2 |
| algr %r1,%r0 /* r1 = cputime as TOD value */ |
| mghi %r1,1000 /* convert to nanoseconds */ |
| srlg %r1,%r1,12 /* r1 = cputime in nanosec */ |
| lgr %r4,%r1 |
| larl %r5,13f |
| srlg %r1,%r1,9 /* divide by 1000000000 */ |
| mlg %r0,8(%r5) |
| srlg %r0,%r0,11 /* r0 = tv_sec */ |
| stg %r0,0(%r3) |
| msg %r0,0(%r5) /* calculate tv_nsec */ |
| slgr %r4,%r0 /* r4 = tv_nsec */ |
| stg %r4,8(%r3) |
| lghi %r2,0 |
| aghi %r15,16 |
| br %r14 |
| |
| /* Fallback to system call */ |
| 12: lghi %r1,__NR_clock_gettime |
| svc 0 |
| aghi %r15,16 |
| br %r14 |
| |
| 13: .quad 1000000000 |
| 14: .quad 19342813113834067 |
| .cfi_endproc |
| .size __kernel_clock_gettime,.-__kernel_clock_gettime |
