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>

54 files changed, 94 insertions, 79 deletions

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 @@ static struct irqaction at91rm9200_timer_irq = {
 	.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 @@ static u32 pit_cnt;		/* access only w/system irq blocked */
  * 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 @@ static void __init timer_init(void)
 /*
  * 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 @@ static void __init imx_timer_hardware_init(void)
 	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 @@ void __init ixp4xx_sys_init(void)
 /*
  * 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 @@ static irqreturn_t msm_timer_interrupt(int irq, void *dev_id)
 	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..82801db 100644
--- a/arch/arm/mach-netx/time.c
+++ b/arch/arm/mach-netx/time.c
@@ -104,7 +104,7 @@ static struct irqaction netx_timer_irq = {
 	.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 @@ static struct irqaction omap_mpu_timer2_irq = {
 	.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 @@ static inline void __init omap2_gp_clocksource_init(void) {}
  * 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 @@ static struct clock_event_device ckevt_pxa_osmr0 = {
 	.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 @@ static struct irqaction realview_timer_irq = {
 	.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 @@ static struct irqaction versatile_timer_irq = {
 	.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 @@ static enum clock_event_mode clockevent_mode = CLOCK_EVT_MODE_UNUSED;
 
 /* 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 @@ console_initcall(omap_add_serial_console);
 
 #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 sched_clock(void)
 {
 	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 @@ static u32 ticks_per_jiffy;
 /*
  * 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 @@ static inline unsigned long long cycles_2_ns(cycle_t cyc)
 	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 @@ static struct clocksource clocksource_bfin = {
 	.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 790ef0d..71e3586 100644
--- a/arch/ia64/kernel/cyclone.c
+++ b/arch/ia64/kernel/cyclone.c
@@ -21,7 +21,7 @@ void __init cyclone_setup(void)
 
 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 @@ ia64_init_itm (void)
 	}
 }
 
-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..309f725 100644
--- a/arch/m68knommu/platform/68328/timers.c
+++ b/arch/m68knommu/platform/68328/timers.c
@@ -75,7 +75,7 @@ static struct irqaction m68328_timer_irq = {
 
 /***************************************************************************/
 
-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 struct irqaction pit_irq = {
 
 /***************************************************************************/
 
-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 struct irqaction mcftmr_timer_irq = {
 
 /***************************************************************************/
 
-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 @@ void __init dec_ioasic_clocksource_init(void)
 	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 @@ 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)
 {
 	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 @@ static void __init hub_rt_clock_event_global_init(void)
 	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 @@ static struct clocksource clocksource_rtc = {
 	.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 @@ unsigned long read_persistent_clock(void)
 }
 
 /* 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 @@ unsigned long read_persistent_clock(void)
 	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 @@ unsigned long long sched_clock(void)
 	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 tmu_timer_stop(void)
  */
 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 @@ void udelay(unsigned long usecs)
 }
 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 @@ void __init time_init(void)
 	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 @@ static irqreturn_t um_timer(int irq, void *dev)
 	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 @@ 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,
diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 50dfa3b..340ba4f 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -72,7 +72,7 @@ static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ;
 #ifdef CONFIG_IA64
 static void __iomem *hpet_mctr;
 
-static cycle_t read_hpet(void)
+static cycle_t read_hpet(struct clocksource *cs)
 {
 	return (cycle_t)read_counter((void __iomem *)hpet_mctr);
 }
diff --git a/drivers/clocksource/acpi_pm.c b/drivers/clocksource/acpi_pm.c
index ee19b6e..40bd8c6 100644
--- a/drivers/clocksource/acpi_pm.c
+++ b/drivers/clocksource/acpi_pm.c
@@ -57,7 +57,7 @@ u32 acpi_pm_read_verified(void)
 	return v2;
 }
 
-static cycle_t acpi_pm_read(void)
+static cycle_t acpi_pm_read(struct clocksource *cs)
 {
 	return (cycle_t)read_pmtmr();
 }
@@ -83,7 +83,7 @@ static int __init acpi_pm_good_setup(char *__str)
 }
 __setup("acpi_pm_good", acpi_pm_good_setup);
 
-static cycle_t acpi_pm_read_slow(void)
+static cycle_t acpi_pm_read_slow(struct clocksource *cs)
 {
 	return (cycle_t)acpi_pm_read_verified();
 }
@@ -156,9 +156,9 @@ static int verify_pmtmr_rate(void)
 	unsigned long count, delta;
 
 	mach_prepare_counter();
-	value1 = clocksource_acpi_pm.read();
+	value1 = clocksource_acpi_pm.read(&clocksource_acpi_pm);
 	mach_countup(&count);
-	value2 = clocksource_acpi_pm.read();
+	value2 = clocksource_acpi_pm.read(&clocksource_acpi_pm);
 	delta = (value2 - value1) & ACPI_PM_MASK;
 
 	/* Check that the PMTMR delta is within 5% of what we expect */
@@ -195,9 +195,9 @@ static int __init init_acpi_pm_clocksource(void)
 	/* "verify" this timing source: */
 	for (j = 0; j < ACPI_PM_MONOTONICITY_CHECKS; j++) {
 		udelay(100 * j);
-		value1 = clocksource_acpi_pm.read();
+		value1 = clocksource_acpi_pm.read(&clocksource_acpi_pm);
 		for (i = 0; i < ACPI_PM_READ_CHECKS; i++) {
-			value2 = clocksource_acpi_pm.read();
+			value2 = clocksource_acpi_pm.read(&clocksource_acpi_pm);
 			if (value2 == value1)
 				continue;
 			if (value2 > value1)
diff --git a/drivers/clocksource/cyclone.c b/drivers/clocksource/cyclone.c
index 8615059..64e528e 100644
--- a/drivers/clocksource/cyclone.c
+++ b/drivers/clocksource/cyclone.c
@@ -19,7 +19,7 @@
 int use_cyclone = 0;
 static void __iomem *cyclone_ptr;
 
-static cycle_t read_cyclone(void)
+static cycle_t read_cyclone(struct clocksource *cs)
 {
 	return (cycle_t)readl(cyclone_ptr);
 }
diff --git a/drivers/clocksource/scx200_hrt.c b/drivers/clocksource/scx200_hrt.c
index b92da67..27f4d96 100644
--- a/drivers/clocksource/scx200_hrt.c
+++ b/drivers/clocksource/scx200_hrt.c
@@ -43,7 +43,7 @@ MODULE_PARM_DESC(ppm, "+-adjust to actual XO freq (ppm)");
 /* The base timer frequency, * 27 if selected */
 #define HRT_FREQ   1000000
 
-static cycle_t read_hrt(void)
+static cycle_t read_hrt(struct clocksource *cs)
 {
 	/* Read the timer value */
 	return (cycle_t) inl(scx200_cb_base + SCx200_TIMER_OFFSET);
diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 254f106..01b886e 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -39,7 +39,7 @@
 
 static void __iomem *tcaddr;
 
-static cycle_t tc_get_cycles(void)
+static cycle_t tc_get_cycles(struct clocksource *cs)
 {
 	unsigned long	flags;
 	u32		lower, upper;
diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h
index 573819e..0d96cde 100644
--- a/include/linux/clocksource.h
+++ b/include/linux/clocksource.h
@@ -143,7 +143,7 @@ extern u64 timecounter_cyc2time(struct timecounter *tc,
  *			400-499: Perfect
  *				The ideal clocksource. A must-use where
  *				available.
- * @read:		returns a cycle value
+ * @read:		returns a cycle value, passes clocksource as argument
  * @mask:		bitmask for two's complement
  *			subtraction of non 64 bit counters
  * @mult:		cycle to nanosecond multiplier (adjusted by NTP)
@@ -162,7 +162,7 @@ struct clocksource {
 	char *name;
 	struct list_head list;
 	int rating;
-	cycle_t (*read)(void);
+	cycle_t (*read)(struct clocksource *cs);
 	cycle_t mask;
 	u32 mult;
 	u32 mult_orig;
@@ -271,7 +271,7 @@ static inline u32 clocksource_hz2mult(u32 hz, u32 shift_constant)
  */
 static inline cycle_t clocksource_read(struct clocksource *cs)
 {
-	return cs->read();
+	return cs->read(cs);
 }
 
 /**
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index c46c931..ecfd7b5 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -181,12 +181,12 @@ static void clocksource_watchdog(unsigned long data)
 
 	resumed = test_and_clear_bit(0, &watchdog_resumed);
 
-	wdnow = watchdog->read();
+	wdnow = watchdog->read(watchdog);
 	wd_nsec = cyc2ns(watchdog, (wdnow - watchdog_last) & watchdog->mask);
 	watchdog_last = wdnow;
 
 	list_for_each_entry_safe(cs, tmp, &watchdog_list, wd_list) {
-		csnow = cs->read();
+		csnow = cs->read(cs);
 
 		if (unlikely(resumed)) {
 			cs->wd_last = csnow;
@@ -247,7 +247,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
 
 		list_add(&cs->wd_list, &watchdog_list);
 		if (!started && watchdog) {
-			watchdog_last = watchdog->read();
+			watchdog_last = watchdog->read(watchdog);
 			watchdog_timer.expires = jiffies + WATCHDOG_INTERVAL;
 			add_timer_on(&watchdog_timer,
 				     cpumask_first(cpu_online_mask));
@@ -268,7 +268,7 @@ static void clocksource_check_watchdog(struct clocksource *cs)
 				cse->flags &= ~CLOCK_SOURCE_WATCHDOG;
 			/* Start if list is not empty */
 			if (!list_empty(&watchdog_list)) {
-				watchdog_last = watchdog->read();
+				watchdog_last = watchdog->read(watchdog);
 				watchdog_timer.expires =
 					jiffies + WATCHDOG_INTERVAL;
 				add_timer_on(&watchdog_timer,
diff --git a/kernel/time/jiffies.c b/kernel/time/jiffies.c
index 06f1975..c3f6c30 100644
--- a/kernel/time/jiffies.c
+++ b/kernel/time/jiffies.c
@@ -50,7 +50,7 @@
  */
 #define JIFFIES_SHIFT	8
 
-static cycle_t jiffies_read(void)
+static cycle_t jiffies_read(struct clocksource *cs)
 {
 	return (cycle_t) jiffies;
 }