| /* |
| * Userland implementation of gettimeofday() for 64 bits processes in a |
| * ppc64 kernel for use in the vDSO |
| * |
| * Copyright (C) 2004 Benjamin Herrenschmuidt (benh@kernel.crashing.org), |
| * IBM Corp. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public License |
| * as published by the Free Software Foundation; either version |
| * 2 of the License, or (at your option) any later version. |
| */ |
| #include <asm/processor.h> |
| #include <asm/ppc_asm.h> |
| #include <asm/vdso.h> |
| #include <asm/asm-offsets.h> |
| #include <asm/unistd.h> |
| |
| .text |
| /* |
| * Exact prototype of gettimeofday |
| * |
| * int __kernel_gettimeofday(struct timeval *tv, struct timezone *tz); |
| * |
| */ |
| V_FUNCTION_BEGIN(__kernel_gettimeofday) |
| .cfi_startproc |
| mflr r12 |
| .cfi_register lr,r12 |
| |
| mr r11,r3 /* r11 holds tv */ |
| mr r10,r4 /* r10 holds tz */ |
| bl V_LOCAL_FUNC(__get_datapage) /* get data page */ |
| cmpldi r11,0 /* check if tv is NULL */ |
| beq 2f |
| lis r7,1000000@ha /* load up USEC_PER_SEC */ |
| addi r7,r7,1000000@l |
| bl V_LOCAL_FUNC(__do_get_tspec) /* get sec/us from tb & kernel */ |
| std r4,TVAL64_TV_SEC(r11) /* store sec in tv */ |
| std r5,TVAL64_TV_USEC(r11) /* store usec in tv */ |
| 2: cmpldi r10,0 /* check if tz is NULL */ |
| beq 1f |
| lwz r4,CFG_TZ_MINUTEWEST(r3)/* fill tz */ |
| lwz r5,CFG_TZ_DSTTIME(r3) |
| stw r4,TZONE_TZ_MINWEST(r10) |
| stw r5,TZONE_TZ_DSTTIME(r10) |
| 1: mtlr r12 |
| crclr cr0*4+so |
| li r3,0 /* always success */ |
| blr |
| .cfi_endproc |
| V_FUNCTION_END(__kernel_gettimeofday) |
| |
| |
| /* |
| * Exact prototype of clock_gettime() |
| * |
| * int __kernel_clock_gettime(clockid_t clock_id, struct timespec *tp); |
| * |
| */ |
| V_FUNCTION_BEGIN(__kernel_clock_gettime) |
| .cfi_startproc |
| /* Check for supported clock IDs */ |
| cmpwi cr0,r3,CLOCK_REALTIME |
| cmpwi cr1,r3,CLOCK_MONOTONIC |
| cror cr0*4+eq,cr0*4+eq,cr1*4+eq |
| bne cr0,99f |
| |
| mflr r12 /* r12 saves lr */ |
| .cfi_register lr,r12 |
| mr r11,r4 /* r11 saves tp */ |
| bl V_LOCAL_FUNC(__get_datapage) /* get data page */ |
| lis r7,NSEC_PER_SEC@h /* want nanoseconds */ |
| ori r7,r7,NSEC_PER_SEC@l |
| 50: bl V_LOCAL_FUNC(__do_get_tspec) /* get time from tb & kernel */ |
| bne cr1,80f /* if not monotonic, all done */ |
| |
| /* |
| * CLOCK_MONOTONIC |
| */ |
| |
| /* now we must fixup using wall to monotonic. We need to snapshot |
| * that value and do the counter trick again. Fortunately, we still |
| * have the counter value in r8 that was returned by __do_get_tspec. |
| * At this point, r4,r5 contain our sec/nsec values. |
| */ |
| |
| lwa r6,WTOM_CLOCK_SEC(r3) |
| lwa r9,WTOM_CLOCK_NSEC(r3) |
| |
| /* We now have our result in r6,r9. We create a fake dependency |
| * on that result and re-check the counter |
| */ |
| or r0,r6,r9 |
| xor r0,r0,r0 |
| add r3,r3,r0 |
| ld r0,CFG_TB_UPDATE_COUNT(r3) |
| cmpld cr0,r0,r8 /* check if updated */ |
| bne- 50b |
| |
| /* Add wall->monotonic offset and check for overflow or underflow. |
| */ |
| add r4,r4,r6 |
| add r5,r5,r9 |
| cmpd cr0,r5,r7 |
| cmpdi cr1,r5,0 |
| blt 1f |
| subf r5,r7,r5 |
| addi r4,r4,1 |
| 1: bge cr1,80f |
| addi r4,r4,-1 |
| add r5,r5,r7 |
| |
| 80: std r4,TSPC64_TV_SEC(r11) |
| std r5,TSPC64_TV_NSEC(r11) |
| |
| mtlr r12 |
| crclr cr0*4+so |
| li r3,0 |
| blr |
| |
| /* |
| * syscall fallback |
| */ |
| 99: |
| li r0,__NR_clock_gettime |
| sc |
| blr |
| .cfi_endproc |
| V_FUNCTION_END(__kernel_clock_gettime) |
| |
| |
| /* |
| * Exact prototype of clock_getres() |
| * |
| * int __kernel_clock_getres(clockid_t clock_id, struct timespec *res); |
| * |
| */ |
| V_FUNCTION_BEGIN(__kernel_clock_getres) |
| .cfi_startproc |
| /* Check for supported clock IDs */ |
| cmpwi cr0,r3,CLOCK_REALTIME |
| cmpwi cr1,r3,CLOCK_MONOTONIC |
| cror cr0*4+eq,cr0*4+eq,cr1*4+eq |
| bne cr0,99f |
| |
| li r3,0 |
| cmpli cr0,r4,0 |
| crclr cr0*4+so |
| beqlr |
| lis r5,CLOCK_REALTIME_RES@h |
| ori r5,r5,CLOCK_REALTIME_RES@l |
| std r3,TSPC64_TV_SEC(r4) |
| std r5,TSPC64_TV_NSEC(r4) |
| blr |
| |
| /* |
| * syscall fallback |
| */ |
| 99: |
| li r0,__NR_clock_getres |
| sc |
| blr |
| .cfi_endproc |
| V_FUNCTION_END(__kernel_clock_getres) |
| |
| |
| /* |
| * This is the core of clock_gettime() and gettimeofday(), |
| * it returns the current time in r4 (seconds) and r5. |
| * On entry, r7 gives the resolution of r5, either USEC_PER_SEC |
| * or NSEC_PER_SEC, giving r5 in microseconds or nanoseconds. |
| * It expects the datapage ptr in r3 and doesn't clobber it. |
| * It clobbers r0, r6 and r9. |
| * On return, r8 contains the counter value that can be reused. |
| * This clobbers cr0 but not any other cr field. |
| */ |
| V_FUNCTION_BEGIN(__do_get_tspec) |
| .cfi_startproc |
| /* check for update count & load values */ |
| 1: ld r8,CFG_TB_UPDATE_COUNT(r3) |
| andi. r0,r8,1 /* pending update ? loop */ |
| bne- 1b |
| xor r0,r8,r8 /* create dependency */ |
| add r3,r3,r0 |
| |
| /* Get TB & offset it. We use the MFTB macro which will generate |
| * workaround code for Cell. |
| */ |
| MFTB(r6) |
| ld r9,CFG_TB_ORIG_STAMP(r3) |
| subf r6,r9,r6 |
| |
| /* Scale result */ |
| ld r5,CFG_TB_TO_XS(r3) |
| sldi r6,r6,12 /* compute time since stamp_xtime */ |
| mulhdu r6,r6,r5 /* in units of 2^-32 seconds */ |
| |
| /* Add stamp since epoch */ |
| ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3) |
| lwz r5,STAMP_SEC_FRAC(r3) |
| or r0,r4,r5 |
| or r0,r0,r6 |
| xor r0,r0,r0 |
| add r3,r3,r0 |
| ld r0,CFG_TB_UPDATE_COUNT(r3) |
| cmpld r0,r8 /* check if updated */ |
| bne- 1b /* reload if so */ |
| |
| /* convert to seconds & nanoseconds and add to stamp */ |
| add r6,r6,r5 /* add on fractional seconds of xtime */ |
| mulhwu r5,r6,r7 /* compute micro or nanoseconds and */ |
| srdi r6,r6,32 /* seconds since stamp_xtime */ |
| clrldi r5,r5,32 |
| add r4,r4,r6 |
| blr |
| .cfi_endproc |
| V_FUNCTION_END(__do_get_tspec) |