sparc: convert to arch_gettimeoffset()

This patch converts sparc (specifically sparc32) to use GENERIC_TIME via
the arch_getoffset() infrastructure, reducing the amount of arch
specific code we need to maintain.

The sparc architecture is one of the last 3 arches that need to be
converted.

This patch applies on top of Linus' current -git tree

I've taken my best swing at converting this, but I'm not 100% confident
I got it right. My cross-compiler is now out of date (gcc4.2) so I
wasn't able to check if it compiled. Any assistance from arch
maintainers or testers to get this merged would be great.

Signed-off-by: John Stultz <johnstul@us.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 16 insertions, 87 deletions

diff --git a/arch/sparc/kernel/pcic.c b/arch/sparc/kernel/pcic.c
index 85e7037..4e2724e 100644
--- a/arch/sparc/kernel/pcic.c
+++ b/arch/sparc/kernel/pcic.c
@@ -30,6 +30,7 @@
 #include <asm/oplib.h>
 #include <asm/prom.h>
 #include <asm/pcic.h>
+#include <asm/timex.h>
 #include <asm/timer.h>
 #include <asm/uaccess.h>
 #include <asm/irq_regs.h>
@@ -163,8 +164,6 @@ void __iomem *pcic_regs;
 volatile int pcic_speculative;
 volatile int pcic_trapped;
 
-static void pci_do_gettimeofday(struct timeval *tv);
-static int pci_do_settimeofday(struct timespec *tv);
 
 #define CONFIG_CMD(bus, device_fn, where) (0x80000000 | (((unsigned int)bus) << 16) | (((unsigned int)device_fn) << 8) | (where & ~3))
 
@@ -716,19 +715,27 @@ static irqreturn_t pcic_timer_handler (int irq, void *h)
 #define USECS_PER_JIFFY  10000  /* We have 100HZ "standard" timer for sparc */
 #define TICK_TIMER_LIMIT ((100*1000000/4)/100)
 
+u32 pci_gettimeoffset(void)
+{
+	/*
+	 * We divide all by 100
+	 * to have microsecond resolution and to avoid overflow
+	 */
+	unsigned long count =
+	    readl(pcic0.pcic_regs+PCI_SYS_COUNTER) & ~PCI_SYS_COUNTER_OVERFLOW;
+	count = ((count/100)*USECS_PER_JIFFY) / (TICK_TIMER_LIMIT/100);
+	return count * 1000;
+}
+
+
 void __init pci_time_init(void)
 {
 	struct linux_pcic *pcic = &pcic0;
 	unsigned long v;
 	int timer_irq, irq;
 
-	/* A hack until do_gettimeofday prototype is moved to arch specific headers
-	   and btfixupped. Patch do_gettimeofday with ba pci_do_gettimeofday; nop */
-	((unsigned int *)do_gettimeofday)[0] = 
-	    0x10800000 | ((((unsigned long)pci_do_gettimeofday -
-	     (unsigned long)do_gettimeofday) >> 2) & 0x003fffff);
-	((unsigned int *)do_gettimeofday)[1] = 0x01000000;
-	BTFIXUPSET_CALL(bus_do_settimeofday, pci_do_settimeofday, BTFIXUPCALL_NORM);
+	do_arch_gettimeoffset = pci_gettimeoffset;
+
 	btfixup();
 
 	writel (TICK_TIMER_LIMIT, pcic->pcic_regs+PCI_SYS_LIMIT);
@@ -746,84 +753,6 @@ void __init pci_time_init(void)
 	local_irq_enable();
 }
 
-static inline unsigned long do_gettimeoffset(void)
-{
-	/*
-	 * We divide all by 100
-	 * to have microsecond resolution and to avoid overflow
-	 */
-	unsigned long count =
-	    readl(pcic0.pcic_regs+PCI_SYS_COUNTER) & ~PCI_SYS_COUNTER_OVERFLOW;
-	count = ((count/100)*USECS_PER_JIFFY) / (TICK_TIMER_LIMIT/100);
-	return count;
-}
-
-static void pci_do_gettimeofday(struct timeval *tv)
-{
-	unsigned long flags;
-	unsigned long seq;
-	unsigned long usec, sec;
-	unsigned long max_ntp_tick = tick_usec - tickadj;
-
-	do {
-		seq = read_seqbegin_irqsave(&xtime_lock, flags);
-		usec = do_gettimeoffset();
-
-		/*
-		 * If time_adjust is negative then NTP is slowing the clock
-		 * so make sure not to go into next possible interval.
-		 * Better to lose some accuracy than have time go backwards..
-		 */
-		if (unlikely(time_adjust < 0))
-			usec = min(usec, max_ntp_tick);
-
-		sec = xtime.tv_sec;
-		usec += (xtime.tv_nsec / 1000);
-	} while (read_seqretry_irqrestore(&xtime_lock, seq, flags));
-
-	while (usec >= 1000000) {
-		usec -= 1000000;
-		sec++;
-	}
-
-	tv->tv_sec = sec;
-	tv->tv_usec = usec;
-}
-
-static int pci_do_settimeofday(struct timespec *tv)
-{
-	if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC)
-		return -EINVAL;
-
-	/*
-	 * This is revolting. We need to set "xtime" correctly. However, the
-	 * value in this location is the value at the most recent update of
-	 * wall time.  Discover what correction gettimeofday() would have
-	 * made, and then undo it!
-	 */
-	tv->tv_nsec -= 1000 * do_gettimeoffset();
-	while (tv->tv_nsec < 0) {
-		tv->tv_nsec += NSEC_PER_SEC;
-		tv->tv_sec--;
-	}
-
-	wall_to_monotonic.tv_sec += xtime.tv_sec - tv->tv_sec;
-	wall_to_monotonic.tv_nsec += xtime.tv_nsec - tv->tv_nsec;
-
-	if (wall_to_monotonic.tv_nsec > NSEC_PER_SEC) {
-		wall_to_monotonic.tv_nsec -= NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec++;
-	}
-	if (wall_to_monotonic.tv_nsec < 0) {
-		wall_to_monotonic.tv_nsec += NSEC_PER_SEC;
-		wall_to_monotonic.tv_sec--;
-	}
-
-	xtime.tv_sec = tv->tv_sec;
-	xtime.tv_nsec = tv->tv_nsec;
-	ntp_clear();
-	return 0;
-}
 
 #if 0
 static void watchdog_reset() {