[patch 12/46] clocksource: replace is_continuous by a flag field

From: Thomas Gleixner
Date: Tue Jan 23 2007 - 17:15:55 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Using a flag filed allows to encode more than one information into
a variable. Preparatory patch for the generic clocksource verification.

Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>

---
arch/i386/kernel/hpet.c | 2 +-
arch/i386/kernel/tsc.c | 7 +++++--
drivers/clocksource/acpi_pm.c | 3 ++-
drivers/clocksource/cyclone.c | 2 +-
drivers/clocksource/scx200_hrt.c | 2 +-
include/linux/clocksource.h | 10 ++++++++--
kernel/time/jiffies.c | 1 -
kernel/timer.c | 2 +-
8 files changed, 19 insertions(+), 10 deletions(-)

Index: linux-2.6.20-rc4-mm1-bo/arch/i386/kernel/hpet.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/arch/i386/kernel/hpet.c
+++ linux-2.6.20-rc4-mm1-bo/arch/i386/kernel/hpet.c
@@ -26,7 +26,7 @@ static struct clocksource clocksource_hp
.mask = HPET_MASK,
.mult = 0, /* set below */
.shift = HPET_SHIFT,
- .is_continuous = 1,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
};

static int __init init_hpet_clocksource(void)
Index: linux-2.6.20-rc4-mm1-bo/arch/i386/kernel/tsc.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/arch/i386/kernel/tsc.c
+++ linux-2.6.20-rc4-mm1-bo/arch/i386/kernel/tsc.c
@@ -314,7 +314,8 @@ static struct clocksource clocksource_ts
.mult = 0, /* to be set */
.shift = 22,
.update_callback = tsc_update_callback,
- .is_continuous = 1,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS |
+ CLOCK_SOURCE_MUST_VERIFY,
};

static int tsc_update_callback(void)
@@ -435,8 +436,10 @@ static int __init init_tsc_clocksource(v
clocksource_tsc.mult = clocksource_khz2mult(current_tsc_khz,
clocksource_tsc.shift);
/* lower the rating if we already know its unstable: */
- if (check_tsc_unstable())
+ if (check_tsc_unstable()) {
clocksource_tsc.rating = 0;
+ clocksource_tsc.flags &= ~CLOCK_SOURCE_IS_CONTINUOUS;
+ }

init_timer(&verify_tsc_freq_timer);
verify_tsc_freq_timer.function = verify_tsc_freq;
Index: linux-2.6.20-rc4-mm1-bo/drivers/clocksource/acpi_pm.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/drivers/clocksource/acpi_pm.c
+++ linux-2.6.20-rc4-mm1-bo/drivers/clocksource/acpi_pm.c
@@ -72,7 +72,8 @@ static struct clocksource clocksource_ac
.mask = (cycle_t)ACPI_PM_MASK,
.mult = 0, /*to be caluclated*/
.shift = 22,
- .is_continuous = 1,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+
};


Index: linux-2.6.20-rc4-mm1-bo/drivers/clocksource/cyclone.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/drivers/clocksource/cyclone.c
+++ linux-2.6.20-rc4-mm1-bo/drivers/clocksource/cyclone.c
@@ -31,7 +31,7 @@ static struct clocksource clocksource_cy
.mask = CYCLONE_TIMER_MASK,
.mult = 10,
.shift = 0,
- .is_continuous = 1,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
};

static int __init init_cyclone_clocksource(void)
Index: linux-2.6.20-rc4-mm1-bo/drivers/clocksource/scx200_hrt.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/drivers/clocksource/scx200_hrt.c
+++ linux-2.6.20-rc4-mm1-bo/drivers/clocksource/scx200_hrt.c
@@ -57,7 +57,7 @@ static struct clocksource cs_hrt = {
.rating = 250,
.read = read_hrt,
.mask = CLOCKSOURCE_MASK(32),
- .is_continuous = 1,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
/* mult, shift are set based on mhz27 flag */
};

Index: linux-2.6.20-rc4-mm1-bo/include/linux/clocksource.h
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/include/linux/clocksource.h
+++ linux-2.6.20-rc4-mm1-bo/include/linux/clocksource.h
@@ -45,7 +45,7 @@ typedef u64 cycle_t;
* @mult: cycle to nanosecond multiplier
* @shift: cycle to nanosecond divisor (power of two)
* @update_callback: called when safe to alter clocksource values
- * @is_continuous: defines if clocksource is free-running.
+ * @flags: flags describing special properties
* @cycle_interval: Used internally by timekeeping core, please ignore.
* @xtime_interval: Used internally by timekeeping core, please ignore.
*/
@@ -58,7 +58,7 @@ struct clocksource {
u32 mult;
u32 shift;
int (*update_callback)(void);
- int is_continuous;
+ unsigned long flags;

/* timekeeping specific data, ignore */
cycle_t cycle_last, cycle_interval;
@@ -66,6 +66,12 @@ struct clocksource {
s64 error;
};

+/*
+ * Clock source flags bits::
+ */
+#define CLOCK_SOURCE_IS_CONTINUOUS 0x01
+#define CLOCK_SOURCE_MUST_VERIFY 0x02
+
/* simplify initialization of mask field */
#define CLOCKSOURCE_MASK(bits) (cycle_t)(bits<64 ? ((1ULL<<bits)-1) : -1)

Index: linux-2.6.20-rc4-mm1-bo/kernel/time/jiffies.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/kernel/time/jiffies.c
+++ linux-2.6.20-rc4-mm1-bo/kernel/time/jiffies.c
@@ -62,7 +62,6 @@ struct clocksource clocksource_jiffies =
.mask = 0xffffffff, /*32bits*/
.mult = NSEC_PER_JIFFY << JIFFIES_SHIFT, /* details above */
.shift = JIFFIES_SHIFT,
- .is_continuous = 0, /* tick based, not free running */
};

static int __init init_jiffies_clocksource(void)
Index: linux-2.6.20-rc4-mm1-bo/kernel/timer.c
===================================================================
--- linux-2.6.20-rc4-mm1-bo.orig/kernel/timer.c
+++ linux-2.6.20-rc4-mm1-bo/kernel/timer.c
@@ -871,7 +871,7 @@ int timekeeping_is_continuous(void)
do {
seq = read_seqbegin(&xtime_lock);

- ret = clock->is_continuous;
+ ret = clock->flags & CLOCK_SOURCE_IS_CONTINUOUS;

} while (read_seqretry(&xtime_lock, seq));


--

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