The patch titled clocksource: shift helper has been removed from the -mm tree. Its filename was clocksource-shift-helper.patch This patch was dropped because an updated version will be merged The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: clocksource: shift helper From: Daniel Walker <dwalker@xxxxxxxxxx> This is a little helper I pulled from the mips tree. I've seen a couple of bogus shift values, and this helper calculates the shift. This should move the shift selection away from the user, and systematically pick the value base on the hz. I also modified the acpi_pm timer to use this new interface. The original shift was 22 , and after this patch it's increased to 23. Which should make the clocksource slightly more accurate, but shouldn't have much of a visible effect. Signed-off-by: Daniel Walker <dwalker@xxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: john stultz <johnstul@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/clocksource/acpi_pm.c | 5 ++++- include/linux/acpi_pmtmr.h | 5 +++-- include/linux/clocksource.h | 21 +++++++++++++++++++++ 3 files changed, 28 insertions(+), 3 deletions(-) diff -puN drivers/clocksource/acpi_pm.c~clocksource-shift-helper drivers/clocksource/acpi_pm.c --- a/drivers/clocksource/acpi_pm.c~clocksource-shift-helper +++ a/drivers/clocksource/acpi_pm.c @@ -72,7 +72,7 @@ static struct clocksource clocksource_ac .read = acpi_pm_read, .mask = (cycle_t)ACPI_PM_MASK, .mult = 0, /*to be calculated*/ - .shift = 22, + .shift = 0, .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; @@ -183,6 +183,9 @@ static int __init init_acpi_pm_clocksour if (!pmtmr_ioport) return -ENODEV; + clocksource_acpi_pm.shift = + clocksource_hz2shift(ACPI_PM_BITS, PMTMR_TICKS_PER_SEC); + clocksource_acpi_pm.mult = clocksource_hz2mult(PMTMR_TICKS_PER_SEC, clocksource_acpi_pm.shift); diff -puN include/linux/acpi_pmtmr.h~clocksource-shift-helper include/linux/acpi_pmtmr.h --- a/include/linux/acpi_pmtmr.h~clocksource-shift-helper +++ a/include/linux/acpi_pmtmr.h @@ -7,10 +7,11 @@ #define PMTMR_TICKS_PER_SEC 3579545 /* limit it to 24 bits */ -#define ACPI_PM_MASK CLOCKSOURCE_MASK(24) +#define ACPI_PM_BITS 24 +#define ACPI_PM_MASK CLOCKSOURCE_MASK(ACPI_PM_BITS) /* Overrun value */ -#define ACPI_PM_OVRRUN (1<<24) +#define ACPI_PM_OVRRUN (1 << ACPI_PM_BITS) #ifdef CONFIG_X86_PM_TIMER diff -puN include/linux/clocksource.h~clocksource-shift-helper include/linux/clocksource.h --- a/include/linux/clocksource.h~clocksource-shift-helper +++ a/include/linux/clocksource.h @@ -159,6 +159,27 @@ static inline u32 clocksource_hz2mult(u3 } /** + * clocksource_hz2shift - calculates shift from hz and # of bits + * @bits: Number of bits this clocksource uses + * @hz: Clocksource frequency in Hz + * + * Helper functions that calculates the best shift value + * based on the hz and # of bits of any given clock. + */ +static inline u32 clocksource_hz2shift(u32 bits, u32 hz) +{ + u64 temp; + + for (; bits > 0; bits--) { + temp = (u64) NSEC_PER_SEC << bits; + do_div(temp, hz); + if ((temp >> 32) == 0) + break; + } + return bits; +} + +/** * clocksource_read: - Access the clocksource's current cycle value * @cs: pointer to clocksource being read * _ Patches currently in -mm which might be from dwalker@xxxxxxxxxx are linux-next.patch macintosh-therm_pm72-driver_lock-semaphore-to-mutex.patch macintosh-qindfarm_smu_sat-semaphore-to-mutex.patch machintosh-adb-driver-adb_handler_sem-semaphore-to-mutex.patch clocksource-shift-helper.patch profile-likely-unlikely-macros.patch likely_prof-changed-to-use-proc_create.patch likeliness-accounting-change-and-cleanup.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html