1 files changed, 125 insertions, 83 deletions

diff --git a/arch/powerpc/kernel/vdso32/gettimeofday.S b/arch/powerpc/kernel/vdso32/gettimeofday.S
index 72ca26df457e..ee038d4bf252 100644
--- a/arch/powerpc/kernel/vdso32/gettimeofday.S
+++ b/arch/powerpc/kernel/vdso32/gettimeofday.S
@@ -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