mstohz and hztoms

[christos%zoulas.com@localhost (Christos Zoulas)]

Hi,

I was looking at the man page for hstohz and hztoms and their function
signatures say "int hztoms(int);" and "int mztohz(int);" where the
implementations use unsigned. We also have 64 bit specific implementations
only for sparc64 and amd64 and only for mstohz() and not for hztoms():

The following patch does the following:
1. documents the prototypes to take and return unsigned (should the 64
   bit ones be documented to return unsigned long or truncate)?
2. fixes the comparison to 0x20000 to be unsigned like the other calculations
3. moves the 64 bit mstohz in <sys/param.h> so all the 64 bit platforms
   can use it
4. adds an hztoms() 64 bit implementation
5. removes the port-specific mstohz() ones

Comments?

christos

Index: share/man/man9/mstohz.9
===================================================================
RCS file: /cvsroot/src/share/man/man9/mstohz.9,v
retrieving revision 1.11
diff -u -p -u -r1.11 mstohz.9
--- share/man/man9/mstohz.9	20 Oct 2011 10:36:42 -0000	1.11
+++ share/man/man9/mstohz.9	28 Sep 2019 12:47:21 -0000
@@ -24,7 +24,7 @@
 .\" SUCH DAMAGE.
 .\"
 .\"
-.Dd October 20, 2011
+.Dd September 28, 2019
 .Dt MSTOHZ 9
 .Os
 .Sh NAME
@@ -33,10 +33,10 @@
 .Nd convert between milliseconds and system clock ticks
 .Sh SYNOPSIS
 .In sys/param.h
-.Ft int
-.Fn mstohz "int ms"
-.Ft int
-.Fn hztoms "int hz"
+.Ft unsigned int
+.Fn mstohz "unsigned int ms"
+.Ft unsigned int
+.Fn hztoms "unsigned int hz"
 .Sh DESCRIPTION
 The
 .Fn mstohz
Index: sys/sys/param.h
===================================================================
RCS file: /cvsroot/src/sys/sys/param.h,v
retrieving revision 1.614
diff -u -p -u -r1.614 param.h
--- sys/sys/param.h	27 Sep 2019 00:32:03 -0000	1.614
+++ sys/sys/param.h	28 Sep 2019 12:47:21 -0000
@@ -488,21 +488,29 @@
 #ifdef _KERNEL
 /*
  * macro to convert from milliseconds to hz without integer overflow
- * Default version using only 32bits arithmetics.
- * 64bit port can define 64bit version in their <machine/param.h>
- * 0x20000 is safe for hz < 20000
+ * The 32 bit version uses only 32bit arithmetic; 0x20000 is safe for hz < 20000
+ * the 64 bit version does the computation directly.
  */
 #ifndef mstohz
-#define mstohz(ms) \
-	(__predict_false((ms) >= 0x20000) ? \
-	    ((ms +0u) / 1000u) * hz : \
-	    ((ms +0u) * hz) / 1000u)
+# ifdef _LP64
+#  define mstohz(ms) ((ms + 0UL) * hz / 1000)
+# else
+#  define mstohz(ms) \
+	(__predict_false((ms + 0u) >= 0x20000u) ? \
+	    ((ms + 0u) / 1000u) * hz : \
+	    ((ms + 0u) * hz) / 1000u)
+# endif
 #endif
+
 #ifndef hztoms
-#define hztoms(t) \
-	(__predict_false((t) >= 0x20000) ? \
-	    ((t +0u) / hz) * 1000u : \
-	    ((t +0u) * 1000u) / hz)
+# ifdef _LP64
+#  define hztomz(t) (((t) + 0UL) * 1000u / hz)
+# else
+#  define hztoms(t) \
+	(__predict_false((t + 0u) >= 0x20000u) ? \
+	    ((t + 0u) / hz) * 1000u : \
+	    ((t + 0u) * 1000u) / hz)
+# endif
 #endif
 
 #define	hz2bintime(t)	(ms2bintime(hztoms(t)))
Index: sys/arch/amd64/include/param.h
===================================================================
RCS file: /cvsroot/src/sys/arch/amd64/include/param.h,v
retrieving revision 1.31
diff -u -p -u -r1.31 param.h
--- sys/arch/amd64/include/param.h	20 Aug 2019 12:33:04 -0000	1.31
+++ sys/arch/amd64/include/param.h	28 Sep 2019 12:47:21 -0000
@@ -126,8 +126,6 @@
 #define btop(x)				x86_btop(x)
 #define ptob(x)				x86_ptob(x)
 
-#define mstohz(ms) ((ms + 0UL) * hz / 1000)
-
 #else	/*	__x86_64__	*/
 
 #include <i386/param.h>
Index: sys/arch/sparc64/include/param.h
===================================================================
RCS file: /cvsroot/src/sys/arch/sparc64/include/param.h,v
retrieving revision 1.60
diff -u -p -u -r1.60 param.h
--- sys/arch/sparc64/include/param.h	15 May 2019 16:59:10 -0000	1.60
+++ sys/arch/sparc64/include/param.h	28 Sep 2019 12:47:21 -0000
@@ -229,11 +229,6 @@ extern void	delay(unsigned int);
 #define	DELAY(n)	delay(n)
 #endif /* __HIDE_DELAY */
 
-#ifdef	__arch64__
-/* If we're using a 64-bit kernel use 64-bit math */
-#define mstohz(ms) ((ms + 0UL) * hz / 1000)
-#endif
-
 /* Keep this a const so compiler optimization is done */
 extern const int cputyp;