clocksource: pass clocksource to read() callback

Pass clocksource pointer to the read() callback for clocksources.  This
allows us to share the callback between multiple instances.

[hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods]
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/arch/mips/kernel/csrc-ioasic.c b/arch/mips/kernel/csrc-ioasic.c
index 1d5f63c..b551f48 100644
--- a/arch/mips/kernel/csrc-ioasic.c
+++ b/arch/mips/kernel/csrc-ioasic.c
@@ -25,7 +25,7 @@
 #include <asm/dec/ioasic.h>
 #include <asm/dec/ioasic_addrs.h>
 
-static cycle_t dec_ioasic_hpt_read(void)
+static cycle_t dec_ioasic_hpt_read(struct clocksource *cs)
 {
 	return ioasic_read(IO_REG_FCTR);
 }
@@ -47,13 +47,13 @@
 	while (!ds1287_timer_state())
 		;
 
-	start = dec_ioasic_hpt_read();
+	start = dec_ioasic_hpt_read(&clocksource_dec);
 
 	while (i--)
 		while (!ds1287_timer_state())
 			;
 
-	end = dec_ioasic_hpt_read();
+	end = dec_ioasic_hpt_read(&clocksource_dec);
 
 	freq = (end - start) * 10;
 	printk(KERN_INFO "I/O ASIC clock frequency %dHz\n", freq);