Staging: Merge staging-next into Linus's tree
[sfrench/cifs-2.6.git] / arch / powerpc / kernel / vdso64 / gettimeofday.S
index c6401f9e37f1fd2427cc6fa9373a3bff335949c8..e97a9a0dc4ac3af3545118d6dbc190d515be4e0f 100644 (file)
@@ -33,18 +33,11 @@ V_FUNCTION_BEGIN(__kernel_gettimeofday)
        bl      V_LOCAL_FUNC(__get_datapage)    /* get data page */
        cmpldi  r11,0                   /* check if tv is NULL */
        beq     2f
-       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,TVAL64_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
-       std     r0,TVAL64_TV_USEC(r11)  /* store usec in tv */
+       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 */
@@ -75,90 +68,51 @@ 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
+       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
         */
 
-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 +122,6 @@ V_FUNCTION_BEGIN(__kernel_clock_gettime)
        /*
         * syscall fallback
         */
-98:
-       mtlr    r12
-       mr      r3,r10
-       mr      r4,r11
 99:
        li      r0,__NR_clock_gettime
        sc
@@ -216,12 +166,16 @@ V_FUNCTION_END(__kernel_clock_getres)
 
 
 /*
- * This is the core of gettimeofday(), it returns the xsec
- * value in r4 and expects the datapage ptr (non clobbered)
- * in r3. clobbers r0,r4,r5,r6,r7,r8
- * When returning, r8 contains the counter value that can be reused
+ * 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_xsec)
+V_FUNCTION_BEGIN(__do_get_tspec)
   .cfi_startproc
        /* check for update count & load values */
 1:     ld      r8,CFG_TB_UPDATE_COUNT(r3)
@@ -233,23 +187,32 @@ V_FUNCTION_BEGIN(__do_get_xsec)
        /* Get TB & offset it. We use the MFTB macro which will generate
         * workaround code for Cell.
         */
-       MFTB(r7)
+       MFTB(r6)
        ld      r9,CFG_TB_ORIG_STAMP(r3)
-       subf    r7,r9,r7
+       subf    r6,r9,r6
 
        /* Scale result */
        ld      r5,CFG_TB_TO_XS(r3)
-       mulhdu  r7,r7,r5
+       sldi    r6,r6,12                /* compute time since stamp_xtime */
+       mulhdu  r6,r6,r5                /* in units of 2^-32 seconds */
 
        /* Add stamp since epoch */
-       ld      r6,CFG_STAMP_XSEC(r3)
-       add     r4,r6,r7
-
-       xor     r0,r4,r4
+       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   cr0,r0,r8              /* check if updated */
-       bne-    1b
+       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_xsec)
+V_FUNCTION_END(__do_get_tspec)