sh: Turn off IRQs around get_timer_offset() calls.

Since all of the sys_timer sources currently do this on their own
within the ->get_offset() path, it's more sensible to just have
the caller take care of it when grabbing xtime_lock. Incidentally,
this is more in line with what others (ie, ARM) are doing already.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/kernel/time.c

@@ -50,15 +50,20 @@ unsigned long long __attribute__ ((weak)) sched_clock(void)
 #ifndef CONFIG_GENERIC_TIME
 void do_gettimeofday(struct timeval *tv)
 {
+	unsigned long flags;
 	unsigned long seq;
 	unsigned long usec, sec;
 
 	do {
-		seq = read_seqbegin(&xtime_lock);
+		/*
+		 * Turn off IRQs when grabbing xtime_lock, so that
+		 * the sys_timer get_offset code doesn't have to handle it.
+		 */
+		seq = read_seqbegin_irqsave(&xtime_lock, flags);
 		usec = get_timer_offset();
 		sec = xtime.tv_sec;
-		usec += xtime.tv_nsec / 1000;
-	} while (read_seqretry(&xtime_lock, seq));
+		usec += xtime.tv_nsec / NSEC_PER_USEC;
+	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
 
 	while (usec >= 1000000) {
 		usec -= 1000000;
@@ -85,7 +90,7 @@ int do_settimeofday(struct timespec *tv)
 	 * wall time.  Discover what correction gettimeofday() would have
 	 * made, and then undo it!
 	 */
-	nsec -= 1000 * get_timer_offset();
+	nsec -= get_timer_offset() * NSEC_PER_USEC;
 
 	wtm_sec  = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec);
 	wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec);

arch/sh/kernel/timers/timer-cmt.c

@@ -11,7 +11,6 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
-#include <linux/spinlock.h>
 #include <linux/seqlock.h>
 #include <asm/timer.h>
 #include <asm/rtc.h>
@@ -46,13 +45,9 @@
 #error "Unknown CPU SUBTYPE"
 #endif
 
-static DEFINE_SPINLOCK(cmt0_lock);
-
 static unsigned long cmt_timer_get_offset(void)
 {
 	int count;
-	unsigned long flags;
-
 	static unsigned short count_p = 0xffff;    /* for the first call after boot */
 	static unsigned long jiffies_p = 0;
 
@@ -61,7 +56,6 @@ static unsigned long cmt_timer_get_offset(void)
 	 */
 	unsigned long jiffies_t;
 
-	spin_lock_irqsave(&cmt0_lock, flags);
 	/* timer count may underflow right here */
 	count =  ctrl_inw(CMT_CMCOR_0);
 	count -= ctrl_inw(CMT_CMCNT_0);
@@ -88,7 +82,6 @@ static unsigned long cmt_timer_get_offset(void)
 		jiffies_p = jiffies_t;
 
 	count_p = count;
-	spin_unlock_irqrestore(&cmt0_lock, flags);
 
 	count = ((LATCH-1) - count) * TICK_SIZE;
 	count = (count + LATCH/2) / LATCH;
@@ -122,7 +115,7 @@ static irqreturn_t cmt_timer_interrupt(int irq, void *dev_id)
 static struct irqaction cmt_irq = {
 	.name		= "timer",
 	.handler	= cmt_timer_interrupt,
-	.flags		= IRQF_DISABLED,
+	.flags		= IRQF_DISABLED | IRQF_TIMER,
 	.mask		= CPU_MASK_NONE,
 };
 

arch/sh/kernel/timers/timer-mtu2.c

@@ -12,7 +12,6 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
-#include <linux/spinlock.h>
 #include <linux/seqlock.h>
 #include <asm/timer.h>
 #include <asm/io.h>
@@ -28,9 +27,6 @@
  * However, we can implement channel cascade if we go the overflow route and
  * get away with using 2 MTU2 channels as a 32-bit timer.
  */
-
-static DEFINE_SPINLOCK(mtu2_lock);
-
 #define MTU2_TSTR	0xfffe4280
 #define MTU2_TCR_1	0xfffe4380
 #define MTU2_TMDR_1	0xfffe4381
@@ -55,8 +51,6 @@ static DEFINE_SPINLOCK(mtu2_lock);
 static unsigned long mtu2_timer_get_offset(void)
 {
 	int count;
-	unsigned long flags;
-
 	static int count_p = 0x7fff;	/* for the first call after boot */
 	static unsigned long jiffies_p = 0;
 
@@ -65,7 +59,6 @@ static unsigned long mtu2_timer_get_offset(void)
 	 */
 	unsigned long jiffies_t;
 
-	spin_lock_irqsave(&mtu2_lock, flags);
 	/* timer count may underflow right here */
 	count = ctrl_inw(MTU2_TCNT_1);	/* read the latched count */
 
@@ -90,7 +83,6 @@ static unsigned long mtu2_timer_get_offset(void)
 		jiffies_p = jiffies_t;
 
 	count_p = count;
-	spin_unlock_irqrestore(&mtu2_lock, flags);
 
 	count = ((LATCH-1) - count) * TICK_SIZE;
 	count = (count + LATCH/2) / LATCH;
@@ -118,7 +110,7 @@ static irqreturn_t mtu2_timer_interrupt(int irq, void *dev_id)
 static struct irqaction mtu2_irq = {
 	.name		= "timer",
 	.handler	= mtu2_timer_interrupt,
-	.flags		= IRQF_DISABLED,
+	.flags		= IRQF_DISABLED | IRQF_TIMER,
 	.mask		= CPU_MASK_NONE,
 };
 

arch/sh/kernel/timers/timer-tmu.c

@@ -17,7 +17,6 @@
 #include <linux/init.h>
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
-#include <linux/spinlock.h>
 #include <linux/seqlock.h>
 #include <asm/timer.h>
 #include <asm/rtc.h>
@@ -31,13 +30,9 @@
 
 #define TMU0_TCR_CALIB	0x0000
 
-static DEFINE_SPINLOCK(tmu0_lock);
-
 static unsigned long tmu_timer_get_offset(void)
 {
 	int count;
-	unsigned long flags;
-
 	static int count_p = 0x7fffffff;    /* for the first call after boot */
 	static unsigned long jiffies_p = 0;
 
@@ -46,7 +41,6 @@ static unsigned long tmu_timer_get_offset(void)
 	 */
 	unsigned long jiffies_t;
 
-	spin_lock_irqsave(&tmu0_lock, flags);
 	/* timer count may underflow right here */
 	count = ctrl_inl(TMU0_TCNT);	/* read the latched count */
 
@@ -72,7 +66,6 @@ static unsigned long tmu_timer_get_offset(void)
 		jiffies_p = jiffies_t;
 
 	count_p = count;
-	spin_unlock_irqrestore(&tmu0_lock, flags);
 
 	count = ((LATCH-1) - count) * TICK_SIZE;
 	count = (count + LATCH/2) / LATCH;
@@ -106,7 +99,7 @@ static irqreturn_t tmu_timer_interrupt(int irq, void *dummy)
 static struct irqaction tmu_irq = {
 	.name		= "timer",
 	.handler	= tmu_timer_interrupt,
-	.flags		= IRQF_DISABLED,
+	.flags		= IRQF_DISABLED | IRQF_TIMER,
 	.mask		= CPU_MASK_NONE,
 };