Fixed lots of warnings about unportable casts of pointers to volatile

variables: don't depend on the compiler generating atomic code to set
the variables - use inline asm to specify the atomic instruction(s)
explicitly.

3 files changed, 36 insertions, 19 deletions

diff --git a/sys/amd64/include/cpufunc.h b/sys/amd64/include/cpufunc.h
index 204a228..9dce136 100644
--- a/sys/amd64/include/cpufunc.h
+++ b/sys/amd64/include/cpufunc.h
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: cpufunc.h,v 1.50 1996/06/14 11:01:01 asami Exp $
+ *	$Id: cpufunc.h,v 1.51 1996/07/01 18:12:23 bde Exp $
  */
 
 /*
@@ -43,8 +43,6 @@
 #include <sys/cdefs.h>
 #include <sys/types.h>
 
-#include <machine/spl.h>	/* XXX belongs elsewhere */
-
 #ifdef	__GNUC__
 
 static __inline void
@@ -358,6 +356,12 @@ rdtsc(void)
 }
 
 static __inline void
+setbits(volatile unsigned *addr, u_int bits)
+{
+	__asm __volatile("orl %1,%0" : "=m" (*addr) : "ir" (bits));
+}
+
+static __inline void
 write_eflags(u_long ef)
 {
 	__asm __volatile("pushl %0; popfl" : : "r" (ef));
@@ -393,6 +397,7 @@ quad_t	rdmsr		__P((u_int msr));
 quad_t	rdpmc		__P((u_int pmc));
 quad_t	rdtsc		__P((void));
 u_long	read_eflags	__P((void));
+void	setbits		__P((volatile unsigned *addr, u_int bits));
 void	write_eflags	__P((u_long ef));
 void	wrmsr		__P((u_int msr, quad_t newval));
 
@@ -404,4 +409,6 @@ void	ltr		__P((u_short sel));
 u_int	rcr0		__P((void));
 u_long	rcr3		__P((void));
 
+#include <machine/spl.h>	/* XXX belongs elsewhere */
+
 #endif /* !_MACHINE_CPUFUNC_H_ */
diff --git a/sys/i386/include/cpufunc.h b/sys/i386/include/cpufunc.h
index 204a228..9dce136 100644
--- a/sys/i386/include/cpufunc.h
+++ b/sys/i386/include/cpufunc.h
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: cpufunc.h,v 1.50 1996/06/14 11:01:01 asami Exp $
+ *	$Id: cpufunc.h,v 1.51 1996/07/01 18:12:23 bde Exp $
  */
 
 /*
@@ -43,8 +43,6 @@
 #include <sys/cdefs.h>
 #include <sys/types.h>
 
-#include <machine/spl.h>	/* XXX belongs elsewhere */
-
 #ifdef	__GNUC__
 
 static __inline void
@@ -358,6 +356,12 @@ rdtsc(void)
 }
 
 static __inline void
+setbits(volatile unsigned *addr, u_int bits)
+{
+	__asm __volatile("orl %1,%0" : "=m" (*addr) : "ir" (bits));
+}
+
+static __inline void
 write_eflags(u_long ef)
 {
 	__asm __volatile("pushl %0; popfl" : : "r" (ef));
@@ -393,6 +397,7 @@ quad_t	rdmsr		__P((u_int msr));
 quad_t	rdpmc		__P((u_int pmc));
 quad_t	rdtsc		__P((void));
 u_long	read_eflags	__P((void));
+void	setbits		__P((volatile unsigned *addr, u_int bits));
 void	write_eflags	__P((u_long ef));
 void	wrmsr		__P((u_int msr, quad_t newval));
 
@@ -404,4 +409,6 @@ void	ltr		__P((u_short sel));
 u_int	rcr0		__P((void));
 u_long	rcr3		__P((void));
 
+#include <machine/spl.h>	/* XXX belongs elsewhere */
+
 #endif /* !_MACHINE_CPUFUNC_H_ */
diff --git a/sys/i386/include/spl.h b/sys/i386/include/spl.h
index 2c14df5..59f2104 100644
--- a/sys/i386/include/spl.h
+++ b/sys/i386/include/spl.h
@@ -30,7 +30,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id: spl.h,v 1.13 1996/02/07 21:52:57 wollman Exp $
+ *	$Id: spl.h,v 1.14 1996/05/18 03:36:42 dyson Exp $
  */
 
 #ifndef _MACHINE_IPL_H_
@@ -76,6 +76,11 @@
 
 #ifndef	LOCORE
 
+/*
+ * cpl is preserved by interrupt handlers so it is effectively nonvolatile.
+ * ipending and idelayed are changed by interrupt handlers so they are
+ * volatile.
+ */
 extern	unsigned bio_imask;	/* group of interrupts masked with splbio() */
 extern	unsigned cpl;		/* current priority level mask */
 extern	volatile unsigned idelayed;	/* interrupts to become pending */
@@ -85,19 +90,17 @@ extern	unsigned stat_imask;	/* interrupts masked with splstatclock() */
 extern	unsigned tty_imask;	/* group of interrupts masked with spltty() */
 
 /*
- * ipending has to be volatile so that it is read every time it is accessed
- * in splx() and spl0(), but we don't want it to be read nonatomically when
- * it is changed.  Pretending that ipending is a plain int happens to give
- * suitable atomic code for "ipending |= constant;".
+ * The volatile bitmap variables must be set atomically.  This normally
+ * involves using a machine-dependent bit-set or `or' instruction.
  */
-#define	setdelayed()	(*(unsigned *)&ipending |= loadandclear(&idelayed))
-#define	setsoftast()	(*(unsigned *)&ipending |= SWI_AST_PENDING)
-#define	setsoftclock()	(*(unsigned *)&ipending |= SWI_CLOCK_PENDING)
-#define	setsoftnet()	(*(unsigned *)&ipending |= SWI_NET_PENDING)
-#define	setsofttty()	(*(unsigned *)&ipending |= SWI_TTY_PENDING)
-
-#define	schedsofttty()	(*(unsigned *)&idelayed |= SWI_TTY_PENDING)
-#define	schedsoftnet()	(*(unsigned *)&idelayed |= SWI_NET_PENDING)
+#define	setdelayed()	setbits(&ipending, loadandclear(&idelayed))
+#define	setsoftast()	setbits(&ipending, SWI_AST_PENDING)
+#define	setsoftclock()	setbits(&ipending, SWI_CLOCK_PENDING)
+#define	setsoftnet()	setbits(&ipending, SWI_NET_PENDING)
+#define	setsofttty()	setbits(&ipending, SWI_TTY_PENDING)
+
+#define	schedsofttty()	setbits(&idelayed, SWI_TTY_PENDING)
+#define	schedsoftnet()	setbits(&idelayed, SWI_NET_PENDING)
 
 #define	softclockpending()	(ipending & SWI_CLOCK_PENDING)