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/arm/mach-at91/at91rm9200_time.c b/arch/arm/mach-at91/at91rm9200_time.c
index 1ff1bda..309f351 100644
--- a/arch/arm/mach-at91/at91rm9200_time.c
+++ b/arch/arm/mach-at91/at91rm9200_time.c
@@ -85,7 +85,7 @@
 	.handler	= at91rm9200_timer_interrupt
 };
 
-static cycle_t read_clk32k(void)
+static cycle_t read_clk32k(struct clocksource *cs)
 {
 	return read_CRTR();
 }
diff --git a/arch/arm/mach-at91/at91sam926x_time.c b/arch/arm/mach-at91/at91sam926x_time.c
index b63e1d5..4bd56ae 100644
--- a/arch/arm/mach-at91/at91sam926x_time.c
+++ b/arch/arm/mach-at91/at91sam926x_time.c
@@ -31,7 +31,7 @@
  * Clocksource:  just a monotonic counter of MCK/16 cycles.
  * We don't care whether or not PIT irqs are enabled.
  */
-static cycle_t read_pit_clk(void)
+static cycle_t read_pit_clk(struct clocksource *cs)
 {
 	unsigned long flags;
 	u32 elapsed;
diff --git a/arch/arm/mach-davinci/time.c b/arch/arm/mach-davinci/time.c
index f8bcd29..6c227d4 100644
--- a/arch/arm/mach-davinci/time.c
+++ b/arch/arm/mach-davinci/time.c
@@ -238,7 +238,7 @@
 /*
  * clocksource
  */
-static cycle_t read_cycles(void)
+static cycle_t read_cycles(struct clocksource *cs)
 {
 	struct timer_s *t = &timers[TID_CLOCKSOURCE];
 
diff --git a/arch/arm/mach-imx/time.c b/arch/arm/mach-imx/time.c
index aff0ebc..5aef18b 100644
--- a/arch/arm/mach-imx/time.c
+++ b/arch/arm/mach-imx/time.c
@@ -73,7 +73,7 @@
 	IMX_TCTL(TIMER_BASE) = TCTL_FRR | TCTL_CLK_PCLK1 | TCTL_TEN;
 }
 
-cycle_t imx_get_cycles(void)
+cycle_t imx_get_cycles(struct clocksource *cs)
 {
 	return IMX_TCN(TIMER_BASE);
 }
diff --git a/arch/arm/mach-ixp4xx/common.c b/arch/arm/mach-ixp4xx/common.c
index f4656d2..1e93dfe 100644
--- a/arch/arm/mach-ixp4xx/common.c
+++ b/arch/arm/mach-ixp4xx/common.c
@@ -401,7 +401,7 @@
 /*
  * clocksource
  */
-cycle_t ixp4xx_get_cycles(void)
+cycle_t ixp4xx_get_cycles(struct clocksource *cs)
 {
 	return *IXP4XX_OSTS;
 }
diff --git a/arch/arm/mach-msm/timer.c b/arch/arm/mach-msm/timer.c
index 444d9c0..4855b8c 100644
--- a/arch/arm/mach-msm/timer.c
+++ b/arch/arm/mach-msm/timer.c
@@ -57,12 +57,12 @@
 	return IRQ_HANDLED;
 }
 
-static cycle_t msm_gpt_read(void)
+static cycle_t msm_gpt_read(struct clocksource *cs)
 {
 	return readl(MSM_GPT_BASE + TIMER_COUNT_VAL);
 }
 
-static cycle_t msm_dgt_read(void)
+static cycle_t msm_dgt_read(struct clocksource *cs)
 {
 	return readl(MSM_DGT_BASE + TIMER_COUNT_VAL) >> MSM_DGT_SHIFT;
 }
diff --git a/arch/arm/mach-netx/time.c b/arch/arm/mach-netx/time.c
index f201fdd..82801dbf 100644
--- a/arch/arm/mach-netx/time.c
+++ b/arch/arm/mach-netx/time.c
@@ -104,7 +104,7 @@
 	.handler	= netx_timer_interrupt,
 };
 
-cycle_t netx_get_cycles(void)
+cycle_t netx_get_cycles(struct clocksource *cs)
 {
 	return readl(NETX_GPIO_COUNTER_CURRENT(TIMER_CLOCKSOURCE));
 }
diff --git a/arch/arm/mach-ns9xxx/time-ns9360.c b/arch/arm/mach-ns9xxx/time-ns9360.c
index 41df697..7728126 100644
--- a/arch/arm/mach-ns9xxx/time-ns9360.c
+++ b/arch/arm/mach-ns9xxx/time-ns9360.c
@@ -25,7 +25,7 @@
 #define TIMER_CLOCKEVENT 1
 static u32 latch;
 
-static cycle_t ns9360_clocksource_read(void)
+static cycle_t ns9360_clocksource_read(struct clocksource *cs)
 {
 	return __raw_readl(SYS_TR(TIMER_CLOCKSOURCE));
 }
diff --git a/arch/arm/mach-omap1/time.c b/arch/arm/mach-omap1/time.c
index 495a32c..4d56408 100644
--- a/arch/arm/mach-omap1/time.c
+++ b/arch/arm/mach-omap1/time.c
@@ -198,7 +198,7 @@
 	.handler	= omap_mpu_timer2_interrupt,
 };
 
-static cycle_t mpu_read(void)
+static cycle_t mpu_read(struct clocksource *cs)
 {
 	return ~omap_mpu_timer_read(1);
 }
diff --git a/arch/arm/mach-omap2/timer-gp.c b/arch/arm/mach-omap2/timer-gp.c
index 9fc13a2..1cb2c09 100644
--- a/arch/arm/mach-omap2/timer-gp.c
+++ b/arch/arm/mach-omap2/timer-gp.c
@@ -138,7 +138,7 @@
  * clocksource
  */
 static struct omap_dm_timer *gpt_clocksource;
-static cycle_t clocksource_read_cycles(void)
+static cycle_t clocksource_read_cycles(struct clocksource *cs)
 {
 	return (cycle_t)omap_dm_timer_read_counter(gpt_clocksource);
 }
diff --git a/arch/arm/mach-pxa/time.c b/arch/arm/mach-pxa/time.c
index 8eb3830..750c448 100644
--- a/arch/arm/mach-pxa/time.c
+++ b/arch/arm/mach-pxa/time.c
@@ -125,7 +125,7 @@
 	.set_mode	= pxa_osmr0_set_mode,
 };
 
-static cycle_t pxa_read_oscr(void)
+static cycle_t pxa_read_oscr(struct clocksource *cs)
 {
 	return OSCR;
 }
diff --git a/arch/arm/mach-realview/core.c b/arch/arm/mach-realview/core.c
index 9ab947c..942e1a7 100644
--- a/arch/arm/mach-realview/core.c
+++ b/arch/arm/mach-realview/core.c
@@ -715,7 +715,7 @@
 	.handler	= realview_timer_interrupt,
 };
 
-static cycle_t realview_get_cycles(void)
+static cycle_t realview_get_cycles(struct clocksource *cs)
 {
 	return ~readl(timer3_va_base + TIMER_VALUE);
 }
diff --git a/arch/arm/mach-versatile/core.c b/arch/arm/mach-versatile/core.c
index 5657766..1f929c3 100644
--- a/arch/arm/mach-versatile/core.c
+++ b/arch/arm/mach-versatile/core.c
@@ -948,7 +948,7 @@
 	.handler	= versatile_timer_interrupt,
 };
 
-static cycle_t versatile_get_cycles(void)
+static cycle_t versatile_get_cycles(struct clocksource *cs)
 {
 	return ~readl(TIMER3_VA_BASE + TIMER_VALUE);
 }
diff --git a/arch/arm/plat-mxc/time.c b/arch/arm/plat-mxc/time.c
index ef1b3cd..dab3357 100644
--- a/arch/arm/plat-mxc/time.c
+++ b/arch/arm/plat-mxc/time.c
@@ -36,7 +36,7 @@
 
 /* clock source */
 
-static cycle_t mxc_get_cycles(void)
+static cycle_t mxc_get_cycles(struct clocksource *cs)
 {
 	return __raw_readl(TIMER_BASE + MXC_TCN);
 }
diff --git a/arch/arm/plat-omap/common.c b/arch/arm/plat-omap/common.c
index d179714..433021f 100644
--- a/arch/arm/plat-omap/common.c
+++ b/arch/arm/plat-omap/common.c
@@ -185,7 +185,7 @@
 
 #include <linux/clocksource.h>
 
-static cycle_t omap_32k_read(void)
+static cycle_t omap_32k_read(struct clocksource *cs)
 {
 	return omap_readl(TIMER_32K_SYNCHRONIZED);
 }
@@ -207,7 +207,7 @@
 {
 	unsigned long long ret;
 
-	ret = (unsigned long long)omap_32k_read();
+	ret = (unsigned long long)omap_32k_read(&clocksource_32k);
 	ret = (ret * clocksource_32k.mult_orig) >> clocksource_32k.shift;
 	return ret;
 }
diff --git a/arch/arm/plat-orion/time.c b/arch/arm/plat-orion/time.c
index 6fa2923..2faf9db 100644
--- a/arch/arm/plat-orion/time.c
+++ b/arch/arm/plat-orion/time.c
@@ -41,7 +41,7 @@
 /*
  * Clocksource handling.
  */
-static cycle_t orion_clksrc_read(void)
+static cycle_t orion_clksrc_read(struct clocksource *cs)
 {
 	return 0xffffffff - readl(TIMER0_VAL);
 }
diff --git a/arch/avr32/kernel/time.c b/arch/avr32/kernel/time.c
index 0ff46bf..f27aa3b 100644
--- a/arch/avr32/kernel/time.c
+++ b/arch/avr32/kernel/time.c
@@ -18,7 +18,7 @@
 #include <mach/pm.h>
 
 
-static cycle_t read_cycle_count(void)
+static cycle_t read_cycle_count(struct clocksource *cs)
 {
 	return (cycle_t)sysreg_read(COUNT);
 }
diff --git a/arch/blackfin/kernel/time-ts.c b/arch/blackfin/kernel/time-ts.c
index 0ed2bad..2764612 100644
--- a/arch/blackfin/kernel/time-ts.c
+++ b/arch/blackfin/kernel/time-ts.c
@@ -58,16 +58,11 @@
 	return (cyc * cyc2ns_scale) >> CYC2NS_SCALE_FACTOR;
 }
 
-static cycle_t read_cycles(void)
+static cycle_t read_cycles(struct clocksource *cs)
 {
 	return __bfin_cycles_off + (get_cycles() << __bfin_cycles_mod);
 }
 
-unsigned long long sched_clock(void)
-{
-	return cycles_2_ns(read_cycles());
-}
-
 static struct clocksource clocksource_bfin = {
 	.name		= "bfin_cycles",
 	.rating		= 350,
@@ -77,6 +72,11 @@
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
+unsigned long long sched_clock(void)
+{
+	return cycles_2_ns(read_cycles(&clocksource_bfin));
+}
+
 static int __init bfin_clocksource_init(void)
 {
 	set_cyc2ns_scale(get_cclk() / 1000);
diff --git a/arch/ia64/kernel/cyclone.c b/arch/ia64/kernel/cyclone.c
index 790ef0d8..71e3586 100644
--- a/arch/ia64/kernel/cyclone.c
+++ b/arch/ia64/kernel/cyclone.c
@@ -21,7 +21,7 @@
 
 static void __iomem *cyclone_mc;
 
-static cycle_t read_cyclone(void)
+static cycle_t read_cyclone(struct clocksource *cs)
 {
 	return (cycle_t)readq((void __iomem *)cyclone_mc);
 }
diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c
index 641c8b6..604c1a3 100644
--- a/arch/ia64/kernel/time.c
+++ b/arch/ia64/kernel/time.c
@@ -33,7 +33,7 @@
 
 #include "fsyscall_gtod_data.h"
 
-static cycle_t itc_get_cycles(void);
+static cycle_t itc_get_cycles(struct clocksource *cs);
 
 struct fsyscall_gtod_data_t fsyscall_gtod_data = {
 	.lock = SEQLOCK_UNLOCKED,
@@ -383,7 +383,7 @@
 	}
 }
 
-static cycle_t itc_get_cycles(void)
+static cycle_t itc_get_cycles(struct clocksource *cs)
 {
 	u64 lcycle, now, ret;
 
diff --git a/arch/ia64/sn/kernel/sn2/timer.c b/arch/ia64/sn/kernel/sn2/timer.c
index cf67fc5..21d6f09 100644
--- a/arch/ia64/sn/kernel/sn2/timer.c
+++ b/arch/ia64/sn/kernel/sn2/timer.c
@@ -23,7 +23,7 @@
 
 extern unsigned long sn_rtc_cycles_per_second;
 
-static cycle_t read_sn2(void)
+static cycle_t read_sn2(struct clocksource *cs)
 {
 	return (cycle_t)readq(RTC_COUNTER_ADDR);
 }
diff --git a/arch/m68knommu/platform/68328/timers.c b/arch/m68knommu/platform/68328/timers.c
index 6bafefa..309f7259 100644
--- a/arch/m68knommu/platform/68328/timers.c
+++ b/arch/m68knommu/platform/68328/timers.c
@@ -75,7 +75,7 @@
 
 /***************************************************************************/
 
-static cycle_t m68328_read_clk(void)
+static cycle_t m68328_read_clk(struct clocksource *cs)
 {
 	unsigned long flags;
 	u32 cycles;
diff --git a/arch/m68knommu/platform/coldfire/dma_timer.c b/arch/m68knommu/platform/coldfire/dma_timer.c
index 772578b..a5f5628 100644
--- a/arch/m68knommu/platform/coldfire/dma_timer.c
+++ b/arch/m68knommu/platform/coldfire/dma_timer.c
@@ -34,7 +34,7 @@
 #define DMA_DTMR_CLK_DIV_16	(2 << 1)
 #define DMA_DTMR_ENABLE		(1 << 0)
 
-static cycle_t cf_dt_get_cycles(void)
+static cycle_t cf_dt_get_cycles(struct clocksource *cs)
 {
 	return __raw_readl(DTCN0);
 }
diff --git a/arch/m68knommu/platform/coldfire/pit.c b/arch/m68knommu/platform/coldfire/pit.c
index 2a12e7f..61b9621 100644
--- a/arch/m68knommu/platform/coldfire/pit.c
+++ b/arch/m68knommu/platform/coldfire/pit.c
@@ -125,7 +125,7 @@
 
 /***************************************************************************/
 
-static cycle_t pit_read_clk(void)
+static cycle_t pit_read_clk(struct clocksource *cs)
 {
 	unsigned long flags;
 	u32 cycles;
diff --git a/arch/m68knommu/platform/coldfire/timers.c b/arch/m68knommu/platform/coldfire/timers.c
index 454f254..1ba8a37 100644
--- a/arch/m68knommu/platform/coldfire/timers.c
+++ b/arch/m68knommu/platform/coldfire/timers.c
@@ -78,7 +78,7 @@
 
 /***************************************************************************/
 
-static cycle_t mcftmr_read_clk(void)
+static cycle_t mcftmr_read_clk(struct clocksource *cs)
 {
 	unsigned long flags;
 	u32 cycles;
diff --git a/arch/mips/kernel/cevt-txx9.c b/arch/mips/kernel/cevt-txx9.c
index eccf7d6..2e911e3 100644
--- a/arch/mips/kernel/cevt-txx9.c
+++ b/arch/mips/kernel/cevt-txx9.c
@@ -22,7 +22,7 @@
 
 static struct txx9_tmr_reg __iomem *txx9_cs_tmrptr;
 
-static cycle_t txx9_cs_read(void)
+static cycle_t txx9_cs_read(struct clocksource *cs)
 {
 	return __raw_readl(&txx9_cs_tmrptr->trr);
 }
diff --git a/arch/mips/kernel/csrc-bcm1480.c b/arch/mips/kernel/csrc-bcm1480.c
index 868745e..51489f8 100644
--- a/arch/mips/kernel/csrc-bcm1480.c
+++ b/arch/mips/kernel/csrc-bcm1480.c
@@ -28,7 +28,7 @@
 
 #include <asm/sibyte/sb1250.h>
 
-static cycle_t bcm1480_hpt_read(void)
+static cycle_t bcm1480_hpt_read(struct clocksource *cs)
 {
 	return (cycle_t) __raw_readq(IOADDR(A_SCD_ZBBUS_CYCLE_COUNT));
 }
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);
diff --git a/arch/mips/kernel/csrc-r4k.c b/arch/mips/kernel/csrc-r4k.c
index f1a2893..e95a3cd 100644
--- a/arch/mips/kernel/csrc-r4k.c
+++ b/arch/mips/kernel/csrc-r4k.c
@@ -10,7 +10,7 @@
 
 #include <asm/time.h>
 
-static cycle_t c0_hpt_read(void)
+static cycle_t c0_hpt_read(struct clocksource *cs)
 {
 	return read_c0_count();
 }
diff --git a/arch/mips/kernel/csrc-sb1250.c b/arch/mips/kernel/csrc-sb1250.c
index 92212bb..d14d3d1 100644
--- a/arch/mips/kernel/csrc-sb1250.c
+++ b/arch/mips/kernel/csrc-sb1250.c
@@ -33,7 +33,7 @@
  * The HPT is free running from SB1250_HPT_VALUE down to 0 then starts over
  * again.
  */
-static cycle_t sb1250_hpt_read(void)
+static cycle_t sb1250_hpt_read(struct clocksource *cs)
 {
 	unsigned int count;
 
diff --git a/arch/mips/kernel/i8253.c b/arch/mips/kernel/i8253.c
index 689719e..ed20e7f 100644
--- a/arch/mips/kernel/i8253.c
+++ b/arch/mips/kernel/i8253.c
@@ -128,7 +128,7 @@
  * 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)
 {
 	unsigned long flags;
 	int count;
diff --git a/arch/mips/nxp/pnx8550/common/time.c b/arch/mips/nxp/pnx8550/common/time.c
index cf293b2..8df43e9 100644
--- a/arch/mips/nxp/pnx8550/common/time.c
+++ b/arch/mips/nxp/pnx8550/common/time.c
@@ -35,7 +35,7 @@
 
 static unsigned long cpj;
 
-static cycle_t hpt_read(void)
+static cycle_t hpt_read(struct clocksource *cs)
 {
 	return read_c0_count2();
 }
diff --git a/arch/mips/sgi-ip27/ip27-timer.c b/arch/mips/sgi-ip27/ip27-timer.c
index f024057..f10a7cd 100644
--- a/arch/mips/sgi-ip27/ip27-timer.c
+++ b/arch/mips/sgi-ip27/ip27-timer.c
@@ -159,7 +159,7 @@
 	setup_irq(irq, &hub_rt_irqaction);
 }
 
-static cycle_t hub_rt_read(void)
+static cycle_t hub_rt_read(struct clocksource *cs)
 {
 	return REMOTE_HUB_L(cputonasid(0), PI_RT_COUNT);
 }
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index 926ea86..48571ac 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -77,7 +77,7 @@
 #include <linux/clockchips.h>
 #include <linux/clocksource.h>
 
-static cycle_t rtc_read(void);
+static cycle_t rtc_read(struct clocksource *);
 static struct clocksource clocksource_rtc = {
 	.name         = "rtc",
 	.rating       = 400,
@@ -88,7 +88,7 @@
 	.read         = rtc_read,
 };
 
-static cycle_t timebase_read(void);
+static cycle_t timebase_read(struct clocksource *);
 static struct clocksource clocksource_timebase = {
 	.name         = "timebase",
 	.rating       = 400,
@@ -766,12 +766,12 @@
 }
 
 /* clocksource code */
-static cycle_t rtc_read(void)
+static cycle_t rtc_read(struct clocksource *cs)
 {
 	return (cycle_t)get_rtc();
 }
 
-static cycle_t timebase_read(void)
+static cycle_t timebase_read(struct clocksource *cs)
 {
 	return (cycle_t)get_tb();
 }
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 6ded50d..ef596d0 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -201,7 +201,7 @@
 	return ts.tv_sec;
 }
 
-static cycle_t read_tod_clock(void)
+static cycle_t read_tod_clock(struct clocksource *cs)
 {
 	return get_clock();
 }
diff --git a/arch/sh/kernel/time_32.c b/arch/sh/kernel/time_32.c
index c34e1e0..1700d24 100644
--- a/arch/sh/kernel/time_32.c
+++ b/arch/sh/kernel/time_32.c
@@ -208,7 +208,7 @@
 	if (!clocksource_sh.rating)
 		return (unsigned long long)jiffies * (NSEC_PER_SEC / HZ);
 
-	cycles = clocksource_sh.read();
+	cycles = clocksource_sh.read(&clocksource_sh);
 	return cyc2ns(&clocksource_sh, cycles);
 }
 #endif
diff --git a/arch/sh/kernel/timers/timer-tmu.c b/arch/sh/kernel/timers/timer-tmu.c
index c5d3396..fe8d893 100644
--- a/arch/sh/kernel/timers/timer-tmu.c
+++ b/arch/sh/kernel/timers/timer-tmu.c
@@ -81,7 +81,7 @@
  */
 static int tmus_are_scaled;
 
-static cycle_t tmu_timer_read(void)
+static cycle_t tmu_timer_read(struct clocksource *cs)
 {
 	return ((cycle_t)(~_tmu_read(TMU1)))<<tmus_are_scaled;
 }
diff --git a/arch/sparc/kernel/time_64.c b/arch/sparc/kernel/time_64.c
index db310aa..5c12e79 100644
--- a/arch/sparc/kernel/time_64.c
+++ b/arch/sparc/kernel/time_64.c
@@ -814,6 +814,11 @@
 }
 EXPORT_SYMBOL(udelay);
 
+static cycle_t clocksource_tick_read(struct clocksource *cs)
+{
+	return tick_ops->get_tick();
+}
+
 void __init time_init(void)
 {
 	unsigned long freq = sparc64_init_timers();
@@ -827,7 +832,7 @@
 	clocksource_tick.mult =
 		clocksource_hz2mult(freq,
 				    clocksource_tick.shift);
-	clocksource_tick.read = tick_ops->get_tick;
+	clocksource_tick.read = clocksource_tick_read;
 
 	printk("clocksource: mult[%x] shift[%d]\n",
 	       clocksource_tick.mult, clocksource_tick.shift);
diff --git a/arch/um/kernel/time.c b/arch/um/kernel/time.c
index b13a87a..c8b9c46 100644
--- a/arch/um/kernel/time.c
+++ b/arch/um/kernel/time.c
@@ -65,7 +65,7 @@
 	return IRQ_HANDLED;
 }
 
-static cycle_t itimer_read(void)
+static cycle_t itimer_read(struct clocksource *cs)
 {
 	return os_nsecs() / 1000;
 }
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 @@
 /*
  * 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 @@
 	hpet_restart_counter();
 
 	/* Verify whether hpet counter works */
-	t1 = read_hpet();
+	t1 = hpet_readl(HPET_COUNTER);
 	rdtscll(start);
 
 	/*
@@ -770,7 +770,7 @@
 		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 @@
  * 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 @@
 	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 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 @@
  * 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 @@
 /** 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 @@
 
 /* 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 @@
 	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 @@
 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,