xnu-1228.3.13.tar.gz

[apple/xnu.git] / osfmk / ppc / commpage / commpage_asm.s

diff --git a/osfmk/ppc/commpage/commpage_asm.s b/osfmk/ppc/commpage/commpage_asm.s
index 92ba18fc31418548b4a1cf33aed002005f601bad..d3ea83c249c9614beef5b5a2afe32cdd42dbc570 100644 (file)
--- a/osfmk/ppc/commpage/commpage_asm.s
+++ b/osfmk/ppc/commpage/commpage_asm.s
@@ -1,5 +1,5 @@
 /*
 /*

- * Copyright (c) 2003 Apple Computer, Inc. All rights reserved.
+ * Copyright (c) 2003-2005 Apple Computer, Inc. All rights reserved.

  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 
  *
  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
  * 


@@ -80,7 +80,7 @@ Ldata:
  *     ***********************************************
  *
  *     Update the gettimeofday() shared data on the commpages, as follows:
  *     ***********************************************
  *
  *     Update the gettimeofday() shared data on the commpages, as follows:

- *             _COMM_PAGE_TIMESTAMP = a BSD-style pair of uint_32's for secs and usecs
+ *             _COMM_PAGE_TIMESTAMP = the clock offset at timebase (seconds)

  *             _COMM_PAGE_TIMEBASE = the timebase at which the timestamp was valid
  *             _COMM_PAGE_SEC_PER_TICK = multiply timebase ticks by this to get seconds (double)
  *     The convention is that if the timebase is 0, the data is invalid.  Because other
  *             _COMM_PAGE_TIMEBASE = the timebase at which the timestamp was valid
  *             _COMM_PAGE_SEC_PER_TICK = multiply timebase ticks by this to get seconds (double)
  *     The convention is that if the timebase is 0, the data is invalid.  Because other


@@ -100,8 +100,8 @@ Ldata:
  *     When called:
  *             r3 = upper half of timebase (timebase is disabled if 0)
  *             r4 = lower half of timebase
  *     When called:
  *             r3 = upper half of timebase (timebase is disabled if 0)
  *             r4 = lower half of timebase

- *             r5 = seconds part of timestamp
- *             r6 = useconds part of timestamp
+ *             r5 = upper half of timestamp
+ *             r6 = lower half of timestamp

  *             r7 = divisor (ie, timebase ticks per sec)
  *     We set up:
  *             r8 = ptr to our static data (kkBinary0, kkDouble1, kkTicksPerSec)
  *             r7 = divisor (ie, timebase ticks per sec)
  *     We set up:
  *             r8 = ptr to our static data (kkBinary0, kkDouble1, kkTicksPerSec)


@@ -112,7 +112,7 @@ Ldata:
  */
  
         .align 5
  */
  
         .align 5

-LEXT(commpage_set_timestamp)                           // void commpage_set_timestamp(tbr,secs,usecs,divisor)
+LEXT(commpage_set_timestamp)                           // void commpage_set_timestamp(tbr,secs,divisor)

         mfmsr  r11                                                     // get MSR
         ori            r2,r11,MASK(MSR_FP)                     // turn FP on
         mtmsr  r2
         mfmsr  r11                                                     // get MSR
         ori            r2,r11,MASK(MSR_FP)                     // turn FP on
         mtmsr  r2


@@ -161,7 +161,7 @@ LEXT(commpage_set_timestamp)                                // void commpage_set_timestamp(tbr,secs,usecs,di
         lfd            f3,kkTicksPerSec(r8)            // float new ticks_per_sec + 2**52
         lfd            f4,kkDouble1(r8)                        // f4 <- double(1.0)
         mffs   f5                                                      // save caller's FPSCR
         lfd            f3,kkTicksPerSec(r8)            // float new ticks_per_sec + 2**52
         lfd            f4,kkDouble1(r8)                        // f4 <- double(1.0)
         mffs   f5                                                      // save caller's FPSCR

-        mtfsfi 7,0                                                     // clear Inexeact Exception bit, set round-to-nearest
+        mtfsfi 7,1                                                     // clear Inexeact Exception bit, set round-to-zero

         fsub   f3,f3,f2                                        // get ticks_per_sec
         fdiv   f3,f4,f3                                        // divide 1 by ticks_per_sec to get SEC_PER_TICK
         stfd   f3,_COMM_PAGE_SEC_PER_TICK(r9)
         fsub   f3,f3,f2                                        // get ticks_per_sec
         fdiv   f3,f4,f3                                        // divide 1 by ticks_per_sec to get SEC_PER_TICK
         stfd   f3,_COMM_PAGE_SEC_PER_TICK(r9)