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>

7 files changed, 19 insertions, 9 deletions

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 648b3a2..3f0019e 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -722,7 +722,7 @@ static int hpet_cpuhp_notify(struct notifier_block *n,
 /*
  * Clock source related code
  */
-static cycle_t read_hpet(void)
+static cycle_t read_hpet(struct clocksource *cs)
 {
 	return (cycle_t)hpet_readl(HPET_COUNTER);
 }
@@ -756,7 +756,7 @@ static int hpet_clocksource_register(void)
 	hpet_restart_counter();
 
 	/* Verify whether hpet counter works */
-	t1 = read_hpet();
+	t1 = hpet_readl(HPET_COUNTER);
 	rdtscll(start);
 
 	/*
@@ -770,7 +770,7 @@ static int hpet_clocksource_register(void)
 		rdtscll(now);
 	} while ((now - start) < 200000UL);
 
-	if (t1 == read_hpet()) {
+	if (t1 == hpet_readl(HPET_COUNTER)) {
 		printk(KERN_WARNING
 		       "HPET counter not counting. HPET disabled\n");
 		return -ENODEV;
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index 3475440..c2e0bb0 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c
@@ -129,7 +129,7 @@ void __init setup_pit_timer(void)
  * to just read by itself. So use jiffies to emulate a free
  * running counter:
  */
-static cycle_t pit_read(void)
+static cycle_t pit_read(struct clocksource *cs)
 {
 	static int old_count;
 	static u32 old_jifs;
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index 137f2e8..223af43 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -77,6 +77,11 @@ static cycle_t kvm_clock_read(void)
 	return ret;
 }
 
+static cycle_t kvm_clock_get_cycles(struct clocksource *cs)
+{
+	return kvm_clock_read();
+}
+
 /*
  * If we don't do that, there is the possibility that the guest
  * will calibrate under heavy load - thus, getting a lower lpj -
@@ -107,7 +112,7 @@ static void kvm_get_preset_lpj(void)
 
 static struct clocksource kvm_clock = {
 	.name = "kvm-clock",
-	.read = kvm_clock_read,
+	.read = kvm_clock_get_cycles,
 	.rating = 400,
 	.mask = CLOCKSOURCE_MASK(64),
 	.mult = 1 << KVM_SCALE,
diff --git a/arch/x86/kernel/tsc.c b/arch/x86/kernel/tsc.c
index 7a567eb..d57de05 100644
--- a/arch/x86/kernel/tsc.c
+++ b/arch/x86/kernel/tsc.c
@@ -699,7 +699,7 @@ static struct clocksource clocksource_tsc;
  * code, which is necessary to support wrapping clocksources like pm
  * timer.
  */
-static cycle_t read_tsc(void)
+static cycle_t read_tsc(struct clocksource *cs)
 {
 	cycle_t ret = (cycle_t)get_cycles();
 
diff --git a/arch/x86/kernel/vmiclock_32.c b/arch/x86/kernel/vmiclock_32.c
index d303369..2b3eb82 100644
--- a/arch/x86/kernel/vmiclock_32.c
+++ b/arch/x86/kernel/vmiclock_32.c
@@ -283,7 +283,7 @@ void __devinit vmi_time_ap_init(void)
 /** vmi clocksource */
 static struct clocksource clocksource_vmi;
 
-static cycle_t read_real_cycles(void)
+static cycle_t read_real_cycles(struct clocksource *cs)
 {
 	cycle_t ret = (cycle_t)vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL);
 	return max(ret, clocksource_vmi.cycle_last);
diff --git a/arch/x86/lguest/boot.c b/arch/x86/lguest/boot.c
index a208536..ca7ec44 100644
--- a/arch/x86/lguest/boot.c
+++ b/arch/x86/lguest/boot.c
@@ -663,7 +663,7 @@ static unsigned long lguest_tsc_khz(void)
 
 /* If we can't use the TSC, the kernel falls back to our lower-priority
  * "lguest_clock", where we read the time value given to us by the Host. */
-static cycle_t lguest_clock_read(void)
+static cycle_t lguest_clock_read(struct clocksource *cs)
 {
 	unsigned long sec, nsec;
 
diff --git a/arch/x86/xen/time.c b/arch/x86/xen/time.c
index 14f2406..0a5aa44 100644
--- a/arch/x86/xen/time.c
+++ b/arch/x86/xen/time.c
@@ -213,6 +213,11 @@ cycle_t xen_clocksource_read(void)
 	return ret;
 }
 
+static cycle_t xen_clocksource_get_cycles(struct clocksource *cs)
+{
+	return xen_clocksource_read();
+}
+
 static void xen_read_wallclock(struct timespec *ts)
 {
 	struct shared_info *s = HYPERVISOR_shared_info;
@@ -241,7 +246,7 @@ int xen_set_wallclock(unsigned long now)
 static struct clocksource xen_clocksource __read_mostly = {
 	.name = "xen",
 	.rating = 400,
-	.read = xen_clocksource_read,
+	.read = xen_clocksource_get_cycles,
 	.mask = ~0,
 	.mult = 1<<XEN_SHIFT,		/* time directly in nanoseconds */
 	.shift = XEN_SHIFT,