Implement time_after() and firends as static inline functions.

The previous macros were too optimistic about types and also did a signed
subtraction that could overflow.
OK miod@ kettenis@ deraadt@ jsg@

diff --git a/sys/dev/pci/drm/include/linux/jiffies.h b/sys/dev/pci/drm/include/linux/jiffies.h
index 24e15fe..8278b76 100644 (file)
--- a/sys/dev/pci/drm/include/linux/jiffies.h
+++ b/sys/dev/pci/drm/include/linux/jiffies.h
@@ -41,9 +41,20 @@ jiffies_to_nsecs(const unsigned long x)
 #define nsecs_to_jiffies(x)    (((uint64_t)(x)) * hz / 1000000000)
 #define nsecs_to_jiffies64(x)  (((uint64_t)(x)) * hz / 1000000000)
 #define get_jiffies_64()       jiffies
-#define time_after(a,b)                ((long)(b) - (long)(a) < 0)
+
+static inline int
+time_after(const unsigned long a, const unsigned long b)
+{
+       return((long)(b - a) < 0);
+}
+#define time_before(a,b)       time_after(b,a)
+
+static inline int
+time_after_eq(const unsigned long a, const unsigned long b)
+{
+       return((long)(b - a) <= 0);
+}
+
 #define time_after32(a,b)      ((int32_t)((uint32_t)(b) - (uint32_t)(a)) < 0)
-#define time_after_eq(a,b)     ((long)(b) - (long)(a) <= 0)
-#define time_before(a,b)       ((long)(a) - (long)(b) < 0)
 
 #endif