From b01cc1b0eae0dea19257b29347116505fbedf679 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 26 Apr 2010 19:03:05 -0700 Subject: x86: Convert remaining x86 clocksources to clocksource_register_hz/khz This converts the remaining x86 clocksources to use clocksource_register_hz/khz. CC: jacob.jun.pan@intel.com CC: Glauber Costa CC: Dimitri Sivanich CC: Rusty Russell CC: Jeremy Fitzhardinge CC: Chris McDermott CC: Thomas Gleixner Tested-by: Konrad Rzeszutek Wilk [xen] Signed-off-by: John Stultz --- drivers/clocksource/cyclone.c | 10 ++-------- 1 file changed, 2 insertions(+), 8 deletions(-) (limited to 'drivers') diff --git a/drivers/clocksource/cyclone.c b/drivers/clocksource/cyclone.c index 64e528e8bfa6..72f811f73e9c 100644 --- a/drivers/clocksource/cyclone.c +++ b/drivers/clocksource/cyclone.c @@ -29,8 +29,6 @@ static struct clocksource clocksource_cyclone = { .rating = 250, .read = read_cyclone, .mask = CYCLONE_TIMER_MASK, - .mult = 10, - .shift = 0, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; @@ -108,12 +106,8 @@ static int __init init_cyclone_clocksource(void) } cyclone_ptr = cyclone_timer; - /* sort out mult/shift values: */ - clocksource_cyclone.shift = 22; - clocksource_cyclone.mult = clocksource_hz2mult(CYCLONE_TIMER_FREQ, - clocksource_cyclone.shift); - - return clocksource_register(&clocksource_cyclone); + return clocksource_register_hz(&clocksource_cyclone, + CYCLONE_TIMER_FREQ); } arch_initcall(init_cyclone_clocksource); -- cgit 1.4.1 From d60c3041778c11f564969fb62b337df68232ee80 Mon Sep 17 00:00:00 2001 From: John Stultz Date: Mon, 26 Apr 2010 20:20:47 -0700 Subject: ia64: convert to clocksource_register_hz/khz This converts the ia64 clocksources to use clocksource_register_hz/khz CC: Tony Luck CC: Thomas Gleixner Tested-by: Tony Luck [clocksource_itc path] Signed-off-by: John Stultz --- arch/ia64/kernel/cyclone.c | 6 +----- arch/ia64/kernel/time.c | 9 ++------- arch/ia64/sn/kernel/sn2/timer.c | 6 +----- drivers/char/hpet.c | 6 +----- 4 files changed, 5 insertions(+), 22 deletions(-) (limited to 'drivers') diff --git a/arch/ia64/kernel/cyclone.c b/arch/ia64/kernel/cyclone.c index d52f1f78eff2..f64097b5118a 100644 --- a/arch/ia64/kernel/cyclone.c +++ b/arch/ia64/kernel/cyclone.c @@ -31,8 +31,6 @@ static struct clocksource clocksource_cyclone = { .rating = 300, .read = read_cyclone, .mask = (1LL << 40) - 1, - .mult = 0, /*to be caluclated*/ - .shift = 16, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; @@ -118,9 +116,7 @@ int __init init_cyclone_clock(void) /* initialize last tick */ cyclone_mc = cyclone_timer; clocksource_cyclone.fsys_mmio = cyclone_timer; - clocksource_cyclone.mult = clocksource_hz2mult(CYCLONE_TIMER_FREQ, - clocksource_cyclone.shift); - clocksource_register(&clocksource_cyclone); + clocksource_register_hz(&clocksource_cyclone, CYCLONE_TIMER_FREQ); return 0; } diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 9702fa92489e..41c40f0e4796 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -73,8 +73,6 @@ static struct clocksource clocksource_itc = { .rating = 350, .read = itc_get_cycles, .mask = CLOCKSOURCE_MASK(64), - .mult = 0, /*to be calculated*/ - .shift = 16, .flags = CLOCK_SOURCE_IS_CONTINUOUS, #ifdef CONFIG_PARAVIRT .resume = paravirt_clocksource_resume, @@ -374,11 +372,8 @@ ia64_init_itm (void) ia64_cpu_local_tick(); if (!itc_clocksource) { - /* Sort out mult/shift values: */ - clocksource_itc.mult = - clocksource_hz2mult(local_cpu_data->itc_freq, - clocksource_itc.shift); - clocksource_register(&clocksource_itc); + clocksource_register_hz(&clocksource_itc, + local_cpu_data->itc_freq); itc_clocksource = &clocksource_itc; } } diff --git a/arch/ia64/sn/kernel/sn2/timer.c b/arch/ia64/sn/kernel/sn2/timer.c index 21d6f09e3447..c34efda122e1 100644 --- a/arch/ia64/sn/kernel/sn2/timer.c +++ b/arch/ia64/sn/kernel/sn2/timer.c @@ -33,8 +33,6 @@ static struct clocksource clocksource_sn2 = { .rating = 450, .read = read_sn2, .mask = (1LL << 55) - 1, - .mult = 0, - .shift = 10, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; @@ -57,9 +55,7 @@ ia64_sn_udelay (unsigned long usecs) void __init sn_timer_init(void) { clocksource_sn2.fsys_mmio = RTC_COUNTER_ADDR; - clocksource_sn2.mult = clocksource_hz2mult(sn_rtc_cycles_per_second, - clocksource_sn2.shift); - clocksource_register(&clocksource_sn2); + clocksource_register_hz(&clocksource_sn2, sn_rtc_cycles_per_second); ia64_udelay = &ia64_sn_udelay; } diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c index 7066e801b9d3..051474c65b78 100644 --- a/drivers/char/hpet.c +++ b/drivers/char/hpet.c @@ -84,8 +84,6 @@ static struct clocksource clocksource_hpet = { .rating = 250, .read = read_hpet, .mask = CLOCKSOURCE_MASK(64), - .mult = 0, /* to be calculated */ - .shift = 10, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; static struct clocksource *hpet_clocksource; @@ -934,9 +932,7 @@ int hpet_alloc(struct hpet_data *hdp) if (!hpet_clocksource) { hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); - clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq, - clocksource_hpet.shift); - clocksource_register(&clocksource_hpet); + clocksource_register_hz(&clocksource_hpet, hpetp->hp_tick_freq); hpetp->hp_clocksource = &clocksource_hpet; hpet_clocksource = &clocksource_hpet; } -- cgit 1.4.1 From 89c0b8e2520e12d69dafc663dfbd39f8180438ea Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 8 May 2011 18:47:58 +0100 Subject: clocksource: add common i8253 PIT clocksource This is based upon both arch/arm/mach-footbridge/isa-timer.c and arch/x86/kernel/i8253.c. Acked-by: John Stultz Acked-by: Thomas Gleixner Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Ralf Baechle Signed-off-by: Russell King --- drivers/Kconfig | 3 ++ drivers/clocksource/Kconfig | 2 + drivers/clocksource/Makefile | 1 + drivers/clocksource/i8253.c | 88 ++++++++++++++++++++++++++++++++++++++++++++ 4 files changed, 94 insertions(+) create mode 100644 drivers/clocksource/Kconfig create mode 100644 drivers/clocksource/i8253.c (limited to 'drivers') diff --git a/drivers/Kconfig b/drivers/Kconfig index 177c7d156933..557a469c7aa6 100644 --- a/drivers/Kconfig +++ b/drivers/Kconfig @@ -119,4 +119,7 @@ source "drivers/platform/Kconfig" source "drivers/clk/Kconfig" source "drivers/hwspinlock/Kconfig" + +source "drivers/clocksource/Kconfig" + endmenu diff --git a/drivers/clocksource/Kconfig b/drivers/clocksource/Kconfig new file mode 100644 index 000000000000..110aeeb52f9a --- /dev/null +++ b/drivers/clocksource/Kconfig @@ -0,0 +1,2 @@ +config CLKSRC_I8253 + bool diff --git a/drivers/clocksource/Makefile b/drivers/clocksource/Makefile index be61ece6330b..cfb6383b543a 100644 --- a/drivers/clocksource/Makefile +++ b/drivers/clocksource/Makefile @@ -6,3 +6,4 @@ obj-$(CONFIG_CS5535_CLOCK_EVENT_SRC) += cs5535-clockevt.o obj-$(CONFIG_SH_TIMER_CMT) += sh_cmt.o obj-$(CONFIG_SH_TIMER_MTU2) += sh_mtu2.o obj-$(CONFIG_SH_TIMER_TMU) += sh_tmu.o +obj-$(CONFIG_CLKSRC_I8253) += i8253.o diff --git a/drivers/clocksource/i8253.c b/drivers/clocksource/i8253.c new file mode 100644 index 000000000000..225c1761b372 --- /dev/null +++ b/drivers/clocksource/i8253.c @@ -0,0 +1,88 @@ +/* + * i8253 PIT clocksource + */ +#include +#include +#include +#include +#include + +#include + +/* + * Since the PIT overflows every tick, its not very useful + * to just read by itself. So use jiffies to emulate a free + * running counter: + */ +static cycle_t i8253_read(struct clocksource *cs) +{ + static int old_count; + static u32 old_jifs; + unsigned long flags; + int count; + u32 jifs; + + raw_spin_lock_irqsave(&i8253_lock, flags); + /* + * Although our caller may have the read side of xtime_lock, + * this is now a seqlock, and we are cheating in this routine + * by having side effects on state that we cannot undo if + * there is a collision on the seqlock and our caller has to + * retry. (Namely, old_jifs and old_count.) So we must treat + * jiffies as volatile despite the lock. We read jiffies + * before latching the timer count to guarantee that although + * the jiffies value might be older than the count (that is, + * the counter may underflow between the last point where + * jiffies was incremented and the point where we latch the + * count), it cannot be newer. + */ + jifs = jiffies; + outb_pit(0x00, PIT_MODE); /* latch the count ASAP */ + count = inb_pit(PIT_CH0); /* read the latched count */ + count |= inb_pit(PIT_CH0) << 8; + + /* VIA686a test code... reset the latch if count > max + 1 */ + if (count > LATCH) { + outb_pit(0x34, PIT_MODE); + outb_pit(PIT_LATCH & 0xff, PIT_CH0); + outb_pit(PIT_LATCH >> 8, PIT_CH0); + count = PIT_LATCH - 1; + } + + /* + * It's possible for count to appear to go the wrong way for a + * couple of reasons: + * + * 1. The timer counter underflows, but we haven't handled the + * resulting interrupt and incremented jiffies yet. + * 2. Hardware problem with the timer, not giving us continuous time, + * the counter does small "jumps" upwards on some Pentium systems, + * (see c't 95/10 page 335 for Neptun bug.) + * + * Previous attempts to handle these cases intelligently were + * buggy, so we just do the simple thing now. + */ + if (count > old_count && jifs == old_jifs) + count = old_count; + + old_count = count; + old_jifs = jifs; + + raw_spin_unlock_irqrestore(&i8253_lock, flags); + + count = (PIT_LATCH - 1) - count; + + return (cycle_t)(jifs * PIT_LATCH) + count; +} + +static struct clocksource i8253_cs = { + .name = "pit", + .rating = 110, + .read = i8253_read, + .mask = CLOCKSOURCE_MASK(32), +}; + +int __init clocksource_i8253_init(void) +{ + return clocksource_register_hz(&i8253_cs, PIT_TICK_RATE); +} -- cgit 1.4.1