[PKT_SCHED]: Use get_cycles() for PSCHED_CPU clock source

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@redhat.com>

include/net/pkt_sched.h

@@ -16,11 +16,6 @@
 #include <linux/module.h>
 #include <linux/rtnetlink.h>
 
-#ifdef CONFIG_X86_TSC
-#include <asm/msr.h>
-#endif
-
-
 struct rtattr;
 struct Qdisc;
 
@@ -235,42 +230,28 @@ typedef long	psched_tdiff_t;
 #define PSCHED_JIFFIE2US(delay) ((delay)<<PSCHED_JSCALE)
 
 #elif PSCHED_CLOCK_SOURCE == PSCHED_CPU
+#include <asm/timex.h>
 
 extern psched_tdiff_t psched_clock_per_hz;
 extern int psched_clock_scale;
-
+extern psched_time_t psched_time_base;
+extern cycles_t psched_time_mark;
+
+#define PSCHED_GET_TIME(stamp)						\
+do {									\
+	cycles_t cur = get_cycles();					\
+	if (sizeof(cycles_t) == sizeof(u32)) {				\
+		if (cur <= psched_time_mark)				\
+			psched_time_base += 0x100000000ULL;		\
+		psched_time_mark = cur;					\
+		(stamp) = (psched_time_base + cur)>>psched_clock_scale;	\
+	} else {							\
+		(stamp) = cur>>psched_clock_scale;			\
+	}								\
+} while (0)
 #define PSCHED_US2JIFFIE(delay) (((delay)+psched_clock_per_hz-1)/psched_clock_per_hz)
 #define PSCHED_JIFFIE2US(delay) ((delay)*psched_clock_per_hz)
 
-#ifdef CONFIG_X86_TSC
-
-#define PSCHED_GET_TIME(stamp) \
-({ u64 __cur; \
-   rdtscll(__cur); \
-   (stamp) = __cur>>psched_clock_scale; \
-})
-
-#elif defined (__alpha__)
-
-#define PSCHED_WATCHER u32
-
-extern psched_time_t psched_time_base;
-extern PSCHED_WATCHER psched_time_mark;
-
-#define PSCHED_GET_TIME(stamp) \
-({ u32 __res; \
-   __asm__ __volatile__ ("rpcc %0" : "r="(__res)); \
-   if (__res <= psched_time_mark) psched_time_base += 0x100000000UL; \
-   psched_time_mark = __res; \
-   (stamp) = (psched_time_base + __res)>>psched_clock_scale; \
-})
-
-#else
-
-#error PSCHED_CLOCK_SOURCE=PSCHED_CPU is not supported on this arch.
-
-#endif /* ARCH */
-
 #endif /* PSCHED_CLOCK_SOURCE == PSCHED_JIFFIES */
 
 #endif /* PSCHED_CLOCK_SOURCE == PSCHED_GETTIMEOFDAY */

net/sched/sch_api.c

@@ -1109,25 +1109,27 @@ int psched_clock_scale;
 EXPORT_SYMBOL(psched_clock_per_hz);
 EXPORT_SYMBOL(psched_clock_scale);
 
-#ifdef PSCHED_WATCHER
 psched_time_t psched_time_base;
-PSCHED_WATCHER psched_time_mark;
+cycles_t psched_time_mark;
 EXPORT_SYMBOL(psched_time_mark);
 EXPORT_SYMBOL(psched_time_base);
 
+/*
+ * Periodically adjust psched_time_base to avoid overflow
+ * with 32-bit get_cycles(). Safe up to 4GHz CPU.
+ */
 static void psched_tick(unsigned long);
-
 static struct timer_list psched_timer = TIMER_INITIALIZER(psched_tick, 0, 0);
 
 static void psched_tick(unsigned long dummy)
 {
-	psched_time_t dummy_stamp;
-	PSCHED_GET_TIME(dummy_stamp);
-	/* It is OK up to 4GHz cpu */
-	psched_timer.expires = jiffies + 1*HZ;
-	add_timer(&psched_timer);
+	if (sizeof(cycles_t) == sizeof(u32)) {
+		psched_time_t dummy_stamp;
+		PSCHED_GET_TIME(dummy_stamp);
+		psched_timer.expires = jiffies + 1*HZ;
+		add_timer(&psched_timer);
+	}
 }
-#endif
 
 int __init psched_calibrate_clock(void)
 {
@@ -1137,9 +1139,7 @@ int __init psched_calibrate_clock(void)
 	long rdelay;
 	unsigned long stop;
 
-#ifdef PSCHED_WATCHER
 	psched_tick(0);
-#endif
 	stop = jiffies + HZ/10;
 	PSCHED_GET_TIME(stamp);
 	do_gettimeofday(&tv);