290 lines
6.9 KiB
ArmAsm
290 lines
6.9 KiB
ArmAsm
/*
|
|
* 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
|
|
|
|
cmpwi cr5,r3,CLOCK_REALTIME_COARSE
|
|
cmpwi cr6,r3,CLOCK_MONOTONIC_COARSE
|
|
cror cr5*4+eq,cr5*4+eq,cr6*4+eq
|
|
|
|
cror cr0*4+eq,cr0*4+eq,cr5*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
|
|
beq cr5,70f
|
|
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
|
|
b 78f
|
|
|
|
/*
|
|
* For coarse clocks we get data directly from the vdso data page, so
|
|
* we don't need to call __do_get_tspec, but we still need to do the
|
|
* counter trick.
|
|
*/
|
|
70: ld r8,CFG_TB_UPDATE_COUNT(r3)
|
|
andi. r0,r8,1 /* pending update ? loop */
|
|
bne- 70b
|
|
add r3,r3,r0 /* r0 is already 0 */
|
|
|
|
/*
|
|
* CLOCK_REALTIME_COARSE, below values are needed for MONOTONIC_COARSE
|
|
* too
|
|
*/
|
|
ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3)
|
|
ld r5,STAMP_XTIME+TSPC64_TV_NSEC(r3)
|
|
bne cr6,75f
|
|
|
|
/* CLOCK_MONOTONIC_COARSE */
|
|
lwa r6,WTOM_CLOCK_SEC(r3)
|
|
lwa r9,WTOM_CLOCK_NSEC(r3)
|
|
|
|
/* check if counter has updated */
|
|
or r0,r6,r9
|
|
75: or r0,r0,r4
|
|
or r0,r0,r5
|
|
xor r0,r0,r0
|
|
add r3,r3,r0
|
|
ld r0,CFG_TB_UPDATE_COUNT(r3)
|
|
cmpld cr0,r0,r8 /* check if updated */
|
|
bne- 70b
|
|
|
|
/* Counter has not updated, so continue calculating proper values for
|
|
* sec and nsec if monotonic coarse, or just return with the proper
|
|
* values for realtime.
|
|
*/
|
|
bne cr6,80f
|
|
|
|
/* Add wall->monotonic offset and check for overflow or underflow */
|
|
78: add r4,r4,r6
|
|
add r5,r5,r9
|
|
cmpd cr0,r5,r7
|
|
cmpdi cr1,r5,0
|
|
blt 79f
|
|
subf r5,r7,r5
|
|
addi r4,r4,1
|
|
79: 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
|
|
cmpldi 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)
|
|
|
|
/*
|
|
* Exact prototype of time()
|
|
*
|
|
* time_t time(time *t);
|
|
*
|
|
*/
|
|
V_FUNCTION_BEGIN(__kernel_time)
|
|
.cfi_startproc
|
|
mflr r12
|
|
.cfi_register lr,r12
|
|
|
|
mr r11,r3 /* r11 holds t */
|
|
bl V_LOCAL_FUNC(__get_datapage)
|
|
|
|
ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3)
|
|
|
|
cmpldi r11,0 /* check if t is NULL */
|
|
beq 2f
|
|
std r4,0(r11) /* store result at *t */
|
|
2: mtlr r12
|
|
crclr cr0*4+so
|
|
mr r3,r4
|
|
blr
|
|
.cfi_endproc
|
|
V_FUNCTION_END(__kernel_time)
|
|
|
|
|
|
/*
|
|
* 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)
|