powerpc: Improve resolution of VDSO clock_gettime
Currently the clock_gettime implementation in the VDSO produces a result with microsecond resolution for the cases that are handled without a system call, i.e. CLOCK_REALTIME and CLOCK_MONOTONIC. The nanoseconds field of the result is obtained by computing a microseconds value and multiplying by 1000. This changes the code in the VDSO to do the computation for clock_gettime with nanosecond resolution. That means that the resolution of the result will ultimately depend on the timebase frequency. Because the timestamp in the VDSO datapage (stamp_xsec, the real time corresponding to the timebase count in tb_orig_stamp) is in units of 2^-20 seconds, it doesn't have sufficient resolution for computing a result with nanosecond resolution. Therefore this adds a copy of xtime to the VDSO datapage and updates it in update_gtod() along with the other time-related fields. Signed-off-by: Paul Mackerras <paulus@samba.org>
This commit is contained in:
Paul Mackerras
parent
c73049f6aa
commit
597bc5c00b
@ -39,6 +39,7 @@
|
||||
#ifndef __ASSEMBLY__
|
||||
|
||||
#include <linux/unistd.h>
|
||||
#include <linux/time.h>
|
||||
|
||||
#define SYSCALL_MAP_SIZE ((__NR_syscalls + 31) / 32)
|
||||
|
||||
@ -83,6 +84,7 @@ struct vdso_data {
|
||||
__u32 icache_log_block_size; /* L1 i-cache log block size */
|
||||
__s32 wtom_clock_sec; /* Wall to monotonic clock */
|
||||
__s32 wtom_clock_nsec;
|
||||
struct timespec stamp_xtime; /* xtime as at tb_orig_stamp */
|
||||
__u32 syscall_map_64[SYSCALL_MAP_SIZE]; /* map of syscalls */
|
||||
__u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */
|
||||
};
|
||||
@ -102,6 +104,7 @@ struct vdso_data {
|
||||
__u32 tz_dsttime; /* Type of dst correction 0x5C */
|
||||
__s32 wtom_clock_sec; /* Wall to monotonic clock */
|
||||
__s32 wtom_clock_nsec;
|
||||
struct timespec stamp_xtime; /* xtime as at tb_orig_stamp */
|
||||
__u32 syscall_map_32[SYSCALL_MAP_SIZE]; /* map of syscalls */
|
||||
__u32 dcache_block_size; /* L1 d-cache block size */
|
||||
__u32 icache_block_size; /* L1 i-cache block size */
|
||||
|
||||
@ -306,6 +306,7 @@ int main(void)
|
||||
DEFINE(CFG_SYSCALL_MAP32, offsetof(struct vdso_data, syscall_map_32));
|
||||
DEFINE(WTOM_CLOCK_SEC, offsetof(struct vdso_data, wtom_clock_sec));
|
||||
DEFINE(WTOM_CLOCK_NSEC, offsetof(struct vdso_data, wtom_clock_nsec));
|
||||
DEFINE(STAMP_XTIME, offsetof(struct vdso_data, stamp_xtime));
|
||||
DEFINE(CFG_ICACHE_BLOCKSZ, offsetof(struct vdso_data, icache_block_size));
|
||||
DEFINE(CFG_DCACHE_BLOCKSZ, offsetof(struct vdso_data, dcache_block_size));
|
||||
DEFINE(CFG_ICACHE_LOGBLOCKSZ, offsetof(struct vdso_data, icache_log_block_size));
|
||||
|
||||
@ -456,6 +456,7 @@ static inline void update_gtod(u64 new_tb_stamp, u64 new_stamp_xsec,
|
||||
vdso_data->tb_to_xs = new_tb_to_xs;
|
||||
vdso_data->wtom_clock_sec = wall_to_monotonic.tv_sec;
|
||||
vdso_data->wtom_clock_nsec = wall_to_monotonic.tv_nsec;
|
||||
vdso_data->stamp_xtime = xtime;
|
||||
smp_wmb();
|
||||
++(vdso_data->tb_update_count);
|
||||
}
|
||||
|
||||
@ -16,6 +16,13 @@
|
||||
#include <asm/asm-offsets.h>
|
||||
#include <asm/unistd.h>
|
||||
|
||||
/* Offset for the low 32-bit part of a field of long type */
|
||||
#ifdef CONFIG_PPC64
|
||||
#define LOPART 4
|
||||
#else
|
||||
#define LOPART 0
|
||||
#endif
|
||||
|
||||
.text
|
||||
/*
|
||||
* Exact prototype of gettimeofday
|
||||
@ -90,101 +97,53 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
|
||||
|
||||
mflr r12 /* r12 saves lr */
|
||||
.cfi_register lr,r12
|
||||
mr r10,r3 /* r10 saves id */
|
||||
mr r11,r4 /* r11 saves tp */
|
||||
bl __get_datapage@local /* get data page */
|
||||
mr r9,r3 /* datapage ptr in r9 */
|
||||
beq cr1,50f /* if monotonic -> jump there */
|
||||
|
||||
/*
|
||||
* CLOCK_REALTIME
|
||||
*/
|
||||
|
||||
bl __do_get_xsec@local /* get xsec from tb & kernel */
|
||||
bne- 98f /* out of line -> do syscall */
|
||||
|
||||
/* seconds are xsec >> 20 */
|
||||
rlwinm r5,r4,12,20,31
|
||||
rlwimi r5,r3,12,0,19
|
||||
stw r5,TSPC32_TV_SEC(r11)
|
||||
|
||||
/* get remaining xsec and convert to nsec. we scale
|
||||
* up remaining xsec by 12 bits and get the top 32 bits
|
||||
* of the multiplication, then we multiply by 1000
|
||||
*/
|
||||
rlwinm r5,r4,12,0,19
|
||||
lis r6,1000000@h
|
||||
ori r6,r6,1000000@l
|
||||
mulhwu r5,r5,r6
|
||||
mulli r5,r5,1000
|
||||
stw r5,TSPC32_TV_NSEC(r11)
|
||||
mtlr r12
|
||||
crclr cr0*4+so
|
||||
li r3,0
|
||||
blr
|
||||
50: bl __do_get_tspec@local /* get sec/nsec from tb & kernel */
|
||||
bne cr1,80f /* not monotonic -> all done */
|
||||
|
||||
/*
|
||||
* CLOCK_MONOTONIC
|
||||
*/
|
||||
|
||||
50: bl __do_get_xsec@local /* get xsec from tb & kernel */
|
||||
bne- 98f /* out of line -> do syscall */
|
||||
|
||||
/* seconds are xsec >> 20 */
|
||||
rlwinm r6,r4,12,20,31
|
||||
rlwimi r6,r3,12,0,19
|
||||
|
||||
/* get remaining xsec and convert to nsec. we scale
|
||||
* up remaining xsec by 12 bits and get the top 32 bits
|
||||
* of the multiplication, then we multiply by 1000
|
||||
*/
|
||||
rlwinm r7,r4,12,0,19
|
||||
lis r5,1000000@h
|
||||
ori r5,r5,1000000@l
|
||||
mulhwu r7,r7,r5
|
||||
mulli r7,r7,1000
|
||||
|
||||
/* 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_xsec.
|
||||
* At this point, r6,r7 contain our sec/nsec values, r3,r4 and r5
|
||||
* can be used
|
||||
* At this point, r3,r4 contain our sec/nsec values, r5 and r6
|
||||
* can be used, r7 contains NSEC_PER_SEC.
|
||||
*/
|
||||
|
||||
lwz r3,WTOM_CLOCK_SEC(r9)
|
||||
lwz r4,WTOM_CLOCK_NSEC(r9)
|
||||
lwz r5,WTOM_CLOCK_SEC(r9)
|
||||
lwz r6,WTOM_CLOCK_NSEC(r9)
|
||||
|
||||
/* We now have our result in r3,r4. We create a fake dependency
|
||||
* on that result and re-check the counter
|
||||
/* We now have our offset in r5,r6. We create a fake dependency
|
||||
* on that value and re-check the counter
|
||||
*/
|
||||
or r5,r4,r3
|
||||
xor r0,r5,r5
|
||||
or r0,r6,r5
|
||||
xor r0,r0,r0
|
||||
add r9,r9,r0
|
||||
#ifdef CONFIG_PPC64
|
||||
lwz r0,(CFG_TB_UPDATE_COUNT+4)(r9)
|
||||
#else
|
||||
lwz r0,(CFG_TB_UPDATE_COUNT)(r9)
|
||||
#endif
|
||||
lwz r0,(CFG_TB_UPDATE_COUNT+LOPART)(r9)
|
||||
cmpl cr0,r8,r0 /* check if updated */
|
||||
bne- 50b
|
||||
|
||||
/* Calculate and store result. Note that this mimmics the C code,
|
||||
/* Calculate and store result. Note that this mimics the C code,
|
||||
* which may cause funny results if nsec goes negative... is that
|
||||
* possible at all ?
|
||||
*/
|
||||
add r3,r3,r6
|
||||
add r4,r4,r7
|
||||
lis r5,NSEC_PER_SEC@h
|
||||
ori r5,r5,NSEC_PER_SEC@l
|
||||
cmpl cr0,r4,r5
|
||||
cmpli cr1,r4,0
|
||||
add r3,r3,r5
|
||||
add r4,r4,r6
|
||||
cmpw cr0,r4,r7
|
||||
cmpwi cr1,r4,0
|
||||
blt 1f
|
||||
subf r4,r5,r4
|
||||
subf r4,r7,r4
|
||||
addi r3,r3,1
|
||||
1: bge cr1,1f
|
||||
1: bge cr1,80f
|
||||
addi r3,r3,-1
|
||||
add r4,r4,r5
|
||||
1: stw r3,TSPC32_TV_SEC(r11)
|
||||
add r4,r4,r7
|
||||
|
||||
80: stw r3,TSPC32_TV_SEC(r11)
|
||||
stw r4,TSPC32_TV_NSEC(r11)
|
||||
|
||||
mtlr r12
|
||||
@ -195,10 +154,6 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
|
||||
/*
|
||||
* syscall fallback
|
||||
*/
|
||||
98:
|
||||
mtlr r12
|
||||
mr r3,r10
|
||||
mr r4,r11
|
||||
99:
|
||||
li r0,__NR_clock_gettime
|
||||
sc
|
||||
@ -254,11 +209,7 @@ __do_get_xsec:
|
||||
/* Check for update count & load values. We use the low
|
||||
* order 32 bits of the update count
|
||||
*/
|
||||
#ifdef CONFIG_PPC64
|
||||
1: lwz r8,(CFG_TB_UPDATE_COUNT+4)(r9)
|
||||
#else
|
||||
1: lwz r8,(CFG_TB_UPDATE_COUNT)(r9)
|
||||
#endif
|
||||
1: lwz r8,(CFG_TB_UPDATE_COUNT+LOPART)(r9)
|
||||
andi. r0,r8,1 /* pending update ? loop */
|
||||
bne- 1b
|
||||
xor r0,r8,r8 /* create dependency */
|
||||
@ -305,11 +256,7 @@ __do_get_xsec:
|
||||
or r6,r4,r3
|
||||
xor r0,r6,r6
|
||||
add r9,r9,r0
|
||||
#ifdef CONFIG_PPC64
|
||||
lwz r0,(CFG_TB_UPDATE_COUNT+4)(r9)
|
||||
#else
|
||||
lwz r0,(CFG_TB_UPDATE_COUNT)(r9)
|
||||
#endif
|
||||
lwz r0,(CFG_TB_UPDATE_COUNT+LOPART)(r9)
|
||||
cmpl cr0,r8,r0 /* check if updated */
|
||||
bne- 1b
|
||||
|
||||
@ -322,3 +269,98 @@ __do_get_xsec:
|
||||
*/
|
||||
3: blr
|
||||
.cfi_endproc
|
||||
|
||||
/*
|
||||
* This is the core of clock_gettime(), it returns the current
|
||||
* time in seconds and nanoseconds in r3 and r4.
|
||||
* It expects the datapage ptr in r9 and doesn't clobber it.
|
||||
* It clobbers r0, r5, r6, r10 and returns NSEC_PER_SEC in r7.
|
||||
* On return, r8 contains the counter value that can be reused.
|
||||
* This clobbers cr0 but not any other cr field.
|
||||
*/
|
||||
__do_get_tspec:
|
||||
.cfi_startproc
|
||||
/* Check for update count & load values. We use the low
|
||||
* order 32 bits of the update count
|
||||
*/
|
||||
1: lwz r8,(CFG_TB_UPDATE_COUNT+LOPART)(r9)
|
||||
andi. r0,r8,1 /* pending update ? loop */
|
||||
bne- 1b
|
||||
xor r0,r8,r8 /* create dependency */
|
||||
add r9,r9,r0
|
||||
|
||||
/* Load orig stamp (offset to TB) */
|
||||
lwz r5,CFG_TB_ORIG_STAMP(r9)
|
||||
lwz r6,(CFG_TB_ORIG_STAMP+4)(r9)
|
||||
|
||||
/* Get a stable TB value */
|
||||
2: mftbu r3
|
||||
mftbl r4
|
||||
mftbu r0
|
||||
cmpl cr0,r3,r0
|
||||
bne- 2b
|
||||
|
||||
/* Subtract tb orig stamp and shift left 12 bits.
|
||||
*/
|
||||
subfc r7,r6,r4
|
||||
subfe r0,r5,r3
|
||||
slwi r0,r0,12
|
||||
rlwimi. r0,r7,12,20,31
|
||||
slwi r7,r7,12
|
||||
|
||||
/* Load scale factor & do multiplication */
|
||||
lwz r5,CFG_TB_TO_XS(r9) /* load values */
|
||||
lwz r6,(CFG_TB_TO_XS+4)(r9)
|
||||
mulhwu r3,r7,r6
|
||||
mullw r10,r7,r5
|
||||
mulhwu r4,r7,r5
|
||||
addc r10,r3,r10
|
||||
li r3,0
|
||||
|
||||
beq+ 4f /* skip high part computation if 0 */
|
||||
mulhwu r3,r0,r5
|
||||
mullw r7,r0,r5
|
||||
mulhwu r5,r0,r6
|
||||
mullw r6,r0,r6
|
||||
adde r4,r4,r7
|
||||
addze r3,r3
|
||||
addc r4,r4,r5
|
||||
addze r3,r3
|
||||
addc r10,r10,r6
|
||||
|
||||
4: addze r4,r4 /* add in carry */
|
||||
lis r7,NSEC_PER_SEC@h
|
||||
ori r7,r7,NSEC_PER_SEC@l
|
||||
mulhwu r4,r4,r7 /* convert to nanoseconds */
|
||||
|
||||
/* At this point, we have seconds & nanoseconds since the xtime
|
||||
* stamp in r3+CA and r4. Load & add the xtime stamp.
|
||||
*/
|
||||
#ifdef CONFIG_PPC64
|
||||
lwz r5,STAMP_XTIME+TSPC64_TV_SEC+LOPART(r9)
|
||||
lwz r6,STAMP_XTIME+TSPC64_TV_NSEC+LOPART(r9)
|
||||
#else
|
||||
lwz r5,STAMP_XTIME+TSPC32_TV_SEC(r9)
|
||||
lwz r6,STAMP_XTIME+TSPC32_TV_NSEC(r9)
|
||||
#endif
|
||||
add r4,r4,r6
|
||||
adde r3,r3,r5
|
||||
|
||||
/* We now have our result in r3,r4. We create a fake dependency
|
||||
* on that result and re-check the counter
|
||||
*/
|
||||
or r6,r4,r3
|
||||
xor r0,r6,r6
|
||||
add r9,r9,r0
|
||||
lwz r0,(CFG_TB_UPDATE_COUNT+LOPART)(r9)
|
||||
cmpl cr0,r8,r0 /* check if updated */
|
||||
bne- 1b
|
||||
|
||||
/* check for nanosecond overflow and adjust if necessary */
|
||||
cmpw r4,r7
|
||||
bltlr /* all done if no overflow */
|
||||
subf r4,r7,r4 /* adjust if overflow */
|
||||
addi r3,r3,1
|
||||
|
||||
blr
|
||||
.cfi_endproc
|
||||
|
||||
@ -75,90 +75,49 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
|
||||
|
||||
mflr r12 /* r12 saves lr */
|
||||
.cfi_register lr,r12
|
||||
mr r10,r3 /* r10 saves id */
|
||||
mr r11,r4 /* r11 saves tp */
|
||||
bl V_LOCAL_FUNC(__get_datapage) /* get data page */
|
||||
beq cr1,50f /* if monotonic -> jump there */
|
||||
|
||||
/*
|
||||
* CLOCK_REALTIME
|
||||
*/
|
||||
|
||||
bl V_LOCAL_FUNC(__do_get_xsec) /* get xsec from tb & kernel */
|
||||
|
||||
lis r7,15 /* r7 = 1000000 = USEC_PER_SEC */
|
||||
ori r7,r7,16960
|
||||
rldicl r5,r4,44,20 /* r5 = sec = xsec / XSEC_PER_SEC */
|
||||
rldicr r6,r5,20,43 /* r6 = sec * XSEC_PER_SEC */
|
||||
std r5,TSPC64_TV_SEC(r11) /* store sec in tv */
|
||||
subf r0,r6,r4 /* r0 = xsec = (xsec - r6) */
|
||||
mulld r0,r0,r7 /* usec = (xsec * USEC_PER_SEC) /
|
||||
* XSEC_PER_SEC
|
||||
*/
|
||||
rldicl r0,r0,44,20
|
||||
mulli r0,r0,1000 /* nsec = usec * 1000 */
|
||||
std r0,TSPC64_TV_NSEC(r11) /* store nsec in tp */
|
||||
|
||||
mtlr r12
|
||||
crclr cr0*4+so
|
||||
li r3,0
|
||||
blr
|
||||
50: bl V_LOCAL_FUNC(__do_get_tspec) /* get time from tb & kernel */
|
||||
bne cr1,80f /* if not monotonic, all done */
|
||||
|
||||
/*
|
||||
* CLOCK_MONOTONIC
|
||||
*/
|
||||
|
||||
50: bl V_LOCAL_FUNC(__do_get_xsec) /* get xsec from tb & kernel */
|
||||
|
||||
lis r7,15 /* r7 = 1000000 = USEC_PER_SEC */
|
||||
ori r7,r7,16960
|
||||
rldicl r5,r4,44,20 /* r5 = sec = xsec / XSEC_PER_SEC */
|
||||
rldicr r6,r5,20,43 /* r6 = sec * XSEC_PER_SEC */
|
||||
subf r0,r6,r4 /* r0 = xsec = (xsec - r6) */
|
||||
mulld r0,r0,r7 /* usec = (xsec * USEC_PER_SEC) /
|
||||
* XSEC_PER_SEC
|
||||
*/
|
||||
rldicl r6,r0,44,20
|
||||
mulli r6,r6,1000 /* nsec = usec * 1000 */
|
||||
|
||||
/* 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_xsec.
|
||||
* At this point, r5,r6 contain our sec/nsec values.
|
||||
* can be used
|
||||
* have the counter value in r8 that was returned by __do_get_tspec.
|
||||
* At this point, r4,r5 contain our sec/nsec values.
|
||||
*/
|
||||
|
||||
lwa r4,WTOM_CLOCK_SEC(r3)
|
||||
lwa r7,WTOM_CLOCK_NSEC(r3)
|
||||
lwa r6,WTOM_CLOCK_SEC(r3)
|
||||
lwa r9,WTOM_CLOCK_NSEC(r3)
|
||||
|
||||
/* We now have our result in r4,r7. We create a fake dependency
|
||||
/* We now have our result in r6,r9. We create a fake dependency
|
||||
* on that result and re-check the counter
|
||||
*/
|
||||
or r9,r4,r7
|
||||
xor r0,r9,r9
|
||||
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
|
||||
|
||||
/* Calculate and store result. Note that this mimmics the C code,
|
||||
* which may cause funny results if nsec goes negative... is that
|
||||
* possible at all ?
|
||||
/* Add wall->monotonic offset and check for overflow or underflow.
|
||||
*/
|
||||
add r4,r4,r5
|
||||
add r7,r7,r6
|
||||
lis r9,NSEC_PER_SEC@h
|
||||
ori r9,r9,NSEC_PER_SEC@l
|
||||
cmpl cr0,r7,r9
|
||||
cmpli cr1,r7,0
|
||||
add r4,r4,r6
|
||||
add r5,r5,r9
|
||||
cmpd cr0,r5,r7
|
||||
cmpdi cr1,r5,0
|
||||
blt 1f
|
||||
subf r7,r9,r7
|
||||
subf r5,r7,r5
|
||||
addi r4,r4,1
|
||||
1: bge cr1,1f
|
||||
1: bge cr1,80f
|
||||
addi r4,r4,-1
|
||||
add r7,r7,r9
|
||||
1: std r4,TSPC64_TV_SEC(r11)
|
||||
std r7,TSPC64_TV_NSEC(r11)
|
||||
add r5,r5,r7
|
||||
|
||||
80: std r4,TSPC64_TV_SEC(r11)
|
||||
std r5,TSPC64_TV_NSEC(r11)
|
||||
|
||||
mtlr r12
|
||||
crclr cr0*4+so
|
||||
@ -168,10 +127,6 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
|
||||
/*
|
||||
* syscall fallback
|
||||
*/
|
||||
98:
|
||||
mtlr r12
|
||||
mr r3,r10
|
||||
mr r4,r11
|
||||
99:
|
||||
li r0,__NR_clock_gettime
|
||||
sc
|
||||
@ -253,3 +208,59 @@ V_FUNCTION_BEGIN(__do_get_xsec)
|
||||
blr
|
||||
.cfi_endproc
|
||||
V_FUNCTION_END(__do_get_xsec)
|
||||
|
||||
/*
|
||||
* This is the core of clock_gettime(), it returns the current
|
||||
* time in seconds and nanoseconds in r4 and r5.
|
||||
* It expects the datapage ptr in r3 and doesn't clobber it.
|
||||
* It clobbers r0 and r6 and returns NSEC_PER_SEC in r7.
|
||||
* 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(r7)
|
||||
ld r9,CFG_TB_ORIG_STAMP(r3)
|
||||
subf r7,r9,r7
|
||||
|
||||
/* Scale result */
|
||||
ld r5,CFG_TB_TO_XS(r3)
|
||||
sldi r7,r7,12 /* compute time since stamp_xtime */
|
||||
mulhdu r6,r7,r5 /* in units of 2^-32 seconds */
|
||||
|
||||
/* Add stamp since epoch */
|
||||
ld r4,STAMP_XTIME+TSPC64_TV_SEC(r3)
|
||||
ld r5,STAMP_XTIME+TSPC64_TV_NSEC(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 */
|
||||
lis r7,NSEC_PER_SEC@h
|
||||
ori r7,r7,NSEC_PER_SEC@l
|
||||
mulhwu r0,r6,r7 /* compute nanoseconds and */
|
||||
srdi r6,r6,32 /* seconds since stamp_xtime */
|
||||
clrldi r0,r0,32
|
||||
add r5,r5,r0 /* add nanoseconds together */
|
||||
cmpd r5,r7 /* overflow? */
|
||||
add r4,r4,r6
|
||||
bltlr /* all done if no overflow */
|
||||
subf r5,r7,r5 /* if overflow, adjust */
|
||||
addi r4,r4,1
|
||||
blr
|
||||
.cfi_endproc
|
||||
V_FUNCTION_END(__do_get_tspec)
|
||||
|
||||
Loading…
Reference in New Issue
Block a user