diff options
Diffstat (limited to '')
25 files changed, 274 insertions, 245 deletions
diff --git a/drivers/net/ethernet/amd/xgbe/xgbe-ptp.c b/drivers/net/ethernet/amd/xgbe/xgbe-ptp.c index a1bf9d1cdae1..f5acf4cc69bd 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe-ptp.c +++ b/drivers/net/ethernet/amd/xgbe/xgbe-ptp.c @@ -171,15 +171,9 @@ static int xgbe_adjtime(struct ptp_clock_info *info, s64 delta) struct xgbe_prv_data, ptp_clock_info); unsigned long flags; - u64 nsec; spin_lock_irqsave(&pdata->tstamp_lock, flags); - - nsec = timecounter_read(&pdata->tstamp_tc); - - nsec += delta; - timecounter_init(&pdata->tstamp_tc, &pdata->tstamp_cc, nsec); - + timecounter_adjtime(&pdata->tstamp_tc, delta); spin_unlock_irqrestore(&pdata->tstamp_lock, flags); return 0; diff --git a/drivers/net/ethernet/amd/xgbe/xgbe.h b/drivers/net/ethernet/amd/xgbe/xgbe.h index f9ec762ac3f0..2af6affc35a7 100644 --- a/drivers/net/ethernet/amd/xgbe/xgbe.h +++ b/drivers/net/ethernet/amd/xgbe/xgbe.h @@ -124,7 +124,7 @@ #include <linux/if_vlan.h> #include <linux/bitops.h> #include <linux/ptp_clock_kernel.h> -#include <linux/clocksource.h> +#include <linux/timecounter.h> #include <linux/net_tstamp.h> #include <net/dcbnl.h> diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h index c3a6072134f5..792ba72fb5c8 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h @@ -22,7 +22,7 @@ #include <linux/ptp_clock_kernel.h> #include <linux/net_tstamp.h> -#include <linux/clocksource.h> +#include <linux/timecounter.h> /* compilation time flags */ diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c index 72eef9fc883e..2c951326a85d 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c @@ -13267,14 +13267,10 @@ static int bnx2x_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) static int bnx2x_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) { struct bnx2x *bp = container_of(ptp, struct bnx2x, ptp_clock_info); - u64 now; DP(BNX2X_MSG_PTP, "PTP adjtime called, delta = %llx\n", delta); - now = timecounter_read(&bp->timecounter); - now += delta; - /* Re-init the timecounter */ - timecounter_init(&bp->timecounter, &bp->cyclecounter, now); + timecounter_adjtime(&bp->timecounter, delta); return 0; } diff --git a/drivers/net/ethernet/freescale/fec.h b/drivers/net/ethernet/freescale/fec.h index 469691ad4a1e..df8bbddaeb37 100644 --- a/drivers/net/ethernet/freescale/fec.h +++ b/drivers/net/ethernet/freescale/fec.h @@ -16,6 +16,7 @@ #include <linux/clocksource.h> #include <linux/net_tstamp.h> #include <linux/ptp_clock_kernel.h> +#include <linux/timecounter.h> #if defined(CONFIG_M523x) || defined(CONFIG_M527x) || defined(CONFIG_M528x) || \ defined(CONFIG_M520x) || defined(CONFIG_M532x) || \ diff --git a/drivers/net/ethernet/freescale/fec_ptp.c b/drivers/net/ethernet/freescale/fec_ptp.c index 992c8c3db553..1f9cf2345266 100644 --- a/drivers/net/ethernet/freescale/fec_ptp.c +++ b/drivers/net/ethernet/freescale/fec_ptp.c @@ -374,23 +374,9 @@ static int fec_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) struct fec_enet_private *fep = container_of(ptp, struct fec_enet_private, ptp_caps); unsigned long flags; - u64 now; - u32 counter; spin_lock_irqsave(&fep->tmreg_lock, flags); - - now = timecounter_read(&fep->tc); - now += delta; - - /* Get the timer value based on adjusted timestamp. - * Update the counter with the masked value. - */ - counter = now & fep->cc.mask; - writel(counter, fep->hwp + FEC_ATIME); - - /* reset the timecounter */ - timecounter_init(&fep->tc, &fep->cc, now); - + timecounter_adjtime(&fep->tc, delta); spin_unlock_irqrestore(&fep->tmreg_lock, flags); return 0; diff --git a/drivers/net/ethernet/intel/e1000e/e1000.h b/drivers/net/ethernet/intel/e1000e/e1000.h index 7785240a0da1..9416e5a7e0c8 100644 --- a/drivers/net/ethernet/intel/e1000e/e1000.h +++ b/drivers/net/ethernet/intel/e1000e/e1000.h @@ -34,7 +34,7 @@ #include <linux/pci-aspm.h> #include <linux/crc32.h> #include <linux/if_vlan.h> -#include <linux/clocksource.h> +#include <linux/timecounter.h> #include <linux/net_tstamp.h> #include <linux/ptp_clock_kernel.h> #include <linux/ptp_classify.h> diff --git a/drivers/net/ethernet/intel/e1000e/ptp.c b/drivers/net/ethernet/intel/e1000e/ptp.c index fb1a914a3ad4..978ef9c4a043 100644 --- a/drivers/net/ethernet/intel/e1000e/ptp.c +++ b/drivers/net/ethernet/intel/e1000e/ptp.c @@ -90,12 +90,9 @@ static int e1000e_phc_adjtime(struct ptp_clock_info *ptp, s64 delta) struct e1000_adapter *adapter = container_of(ptp, struct e1000_adapter, ptp_clock_info); unsigned long flags; - s64 now; spin_lock_irqsave(&adapter->systim_lock, flags); - now = timecounter_read(&adapter->tc); - now += delta; - timecounter_init(&adapter->tc, &adapter->cc, now); + timecounter_adjtime(&adapter->tc, delta); spin_unlock_irqrestore(&adapter->systim_lock, flags); return 0; diff --git a/drivers/net/ethernet/intel/igb/igb.h b/drivers/net/ethernet/intel/igb/igb.h index 82d891e183b1..ee22da391474 100644 --- a/drivers/net/ethernet/intel/igb/igb.h +++ b/drivers/net/ethernet/intel/igb/igb.h @@ -29,7 +29,7 @@ #include "e1000_mac.h" #include "e1000_82575.h" -#include <linux/clocksource.h> +#include <linux/timecounter.h> #include <linux/net_tstamp.h> #include <linux/ptp_clock_kernel.h> #include <linux/bitops.h> diff --git a/drivers/net/ethernet/intel/igb/igb_ptp.c b/drivers/net/ethernet/intel/igb/igb_ptp.c index 794c139f0cc0..1d27f2d3b57c 100644 --- a/drivers/net/ethernet/intel/igb/igb_ptp.c +++ b/drivers/net/ethernet/intel/igb/igb_ptp.c @@ -256,14 +256,9 @@ static int igb_ptp_adjtime_82576(struct ptp_clock_info *ptp, s64 delta) struct igb_adapter *igb = container_of(ptp, struct igb_adapter, ptp_caps); unsigned long flags; - s64 now; spin_lock_irqsave(&igb->tmreg_lock, flags); - - now = timecounter_read(&igb->tc); - now += delta; - timecounter_init(&igb->tc, &igb->cc, now); - + timecounter_adjtime(&igb->tc, delta); spin_unlock_irqrestore(&igb->tmreg_lock, flags); return 0; diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe.h b/drivers/net/ethernet/intel/ixgbe/ixgbe.h index b6137be43920..38fc64cf5dca 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe.h +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe.h @@ -38,7 +38,7 @@ #include <linux/if_vlan.h> #include <linux/jiffies.h> -#include <linux/clocksource.h> +#include <linux/timecounter.h> #include <linux/net_tstamp.h> #include <linux/ptp_clock_kernel.h> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c index 5fd4b5271f9a..47c29eaaa140 100644 --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c @@ -261,18 +261,9 @@ static int ixgbe_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) struct ixgbe_adapter *adapter = container_of(ptp, struct ixgbe_adapter, ptp_caps); unsigned long flags; - u64 now; spin_lock_irqsave(&adapter->tmreg_lock, flags); - - now = timecounter_read(&adapter->tc); - now += delta; - - /* reset the timecounter */ - timecounter_init(&adapter->tc, - &adapter->cc, - now); - + timecounter_adjtime(&adapter->tc, delta); spin_unlock_irqrestore(&adapter->tmreg_lock, flags); ixgbe_ptp_setup_sdp(adapter); diff --git a/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/drivers/net/ethernet/mellanox/mlx4/en_clock.c index 999014413b1a..e9cce4f72b24 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c @@ -147,12 +147,9 @@ static int mlx4_en_phc_adjtime(struct ptp_clock_info *ptp, s64 delta) struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev, ptp_clock_info); unsigned long flags; - s64 now; write_lock_irqsave(&mdev->clock_lock, flags); - now = timecounter_read(&mdev->clock); - now += delta; - timecounter_init(&mdev->clock, &mdev->cycles, now); + timecounter_adjtime(&mdev->clock, delta); write_unlock_irqrestore(&mdev->clock_lock, flags); return 0; @@ -243,7 +240,7 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev) { struct mlx4_dev *dev = mdev->dev; unsigned long flags; - u64 ns; + u64 ns, zero = 0; rwlock_init(&mdev->clock_lock); @@ -268,7 +265,7 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev) /* Calculate period in seconds to call the overflow watchdog - to make * sure counter is checked at least once every wrap around. */ - ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask); + ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask, zero, &zero); do_div(ns, NSEC_PER_SEC / 2 / HZ); mdev->overflow_period = ns; diff --git a/drivers/net/ethernet/ti/cpts.c b/drivers/net/ethernet/ti/cpts.c index 4a4388b813ac..fbe42cb107ec 100644 --- a/drivers/net/ethernet/ti/cpts.c +++ b/drivers/net/ethernet/ti/cpts.c @@ -157,14 +157,11 @@ static int cpts_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb) static int cpts_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta) { - s64 now; unsigned long flags; struct cpts *cpts = container_of(ptp, struct cpts, info); spin_lock_irqsave(&cpts->lock, flags); - now = timecounter_read(&cpts->tc); - now += delta; - timecounter_init(&cpts->tc, &cpts->cc, now); + timecounter_adjtime(&cpts->tc, delta); spin_unlock_irqrestore(&cpts->lock, flags); return 0; diff --git a/drivers/net/ethernet/ti/cpts.h b/drivers/net/ethernet/ti/cpts.h index 1a581ef7eee8..69a46b92c7d6 100644 --- a/drivers/net/ethernet/ti/cpts.h +++ b/drivers/net/ethernet/ti/cpts.h @@ -27,6 +27,7 @@ #include <linux/list.h> #include <linux/ptp_clock_kernel.h> #include <linux/skbuff.h> +#include <linux/timecounter.h> struct cpsw_cpts { u32 idver; /* Identification and version */ diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h index 6d26b40cbf5d..9916d0e4eff5 100644 --- a/include/clocksource/arm_arch_timer.h +++ b/include/clocksource/arm_arch_timer.h @@ -16,7 +16,7 @@ #ifndef __CLKSOURCE_ARM_ARCH_TIMER_H #define __CLKSOURCE_ARM_ARCH_TIMER_H -#include <linux/clocksource.h> +#include <linux/timecounter.h> #include <linux/types.h> #define ARCH_TIMER_CTRL_ENABLE (1 << 0) diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index abcafaa20b86..9c78d15d33e4 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -18,8 +18,6 @@ #include <asm/div64.h> #include <asm/io.h> -/* clocksource cycle base type */ -typedef u64 cycle_t; struct clocksource; struct module; @@ -28,106 +26,6 @@ struct module; #endif /** - * struct cyclecounter - hardware abstraction for a free running counter - * Provides completely state-free accessors to the underlying hardware. - * Depending on which hardware it reads, the cycle counter may wrap - * around quickly. Locking rules (if necessary) have to be defined - * by the implementor and user of specific instances of this API. - * - * @read: returns the current cycle value - * @mask: bitmask for two's complement - * subtraction of non 64 bit counters, - * see CLOCKSOURCE_MASK() helper macro - * @mult: cycle to nanosecond multiplier - * @shift: cycle to nanosecond divisor (power of two) - */ -struct cyclecounter { - cycle_t (*read)(const struct cyclecounter *cc); - cycle_t mask; - u32 mult; - u32 shift; -}; - -/** - * struct timecounter - layer above a %struct cyclecounter which counts nanoseconds - * Contains the state needed by timecounter_read() to detect - * cycle counter wrap around. Initialize with - * timecounter_init(). Also used to convert cycle counts into the - * corresponding nanosecond counts with timecounter_cyc2time(). Users - * of this code are responsible for initializing the underlying - * cycle counter hardware, locking issues and reading the time - * more often than the cycle counter wraps around. The nanosecond - * counter will only wrap around after ~585 years. - * - * @cc: the cycle counter used by this instance - * @cycle_last: most recent cycle counter value seen by - * timecounter_read() - * @nsec: continuously increasing count - */ -struct timecounter { - const struct cyclecounter *cc; - cycle_t cycle_last; - u64 nsec; -}; - -/** - * cyclecounter_cyc2ns - converts cycle counter cycles to nanoseconds - * @cc: Pointer to cycle counter. - * @cycles: Cycles - * - * XXX - This could use some mult_lxl_ll() asm optimization. Same code - * as in cyc2ns, but with unsigned result. - */ -static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc, - cycle_t cycles) -{ - u64 ret = (u64)cycles; - ret = (ret * cc->mult) >> cc->shift; - return ret; -} - -/** - * timecounter_init - initialize a time counter - * @tc: Pointer to time counter which is to be initialized/reset - * @cc: A cycle counter, ready to be used. - * @start_tstamp: Arbitrary initial time stamp. - * - * After this call the current cycle register (roughly) corresponds to - * the initial time stamp. Every call to timecounter_read() increments - * the time stamp counter by the number of elapsed nanoseconds. - */ -extern void timecounter_init(struct timecounter *tc, - const struct cyclecounter *cc, - u64 start_tstamp); - -/** - * timecounter_read - return nanoseconds elapsed since timecounter_init() - * plus the initial time stamp - * @tc: Pointer to time counter. - * - * In other words, keeps track of time since the same epoch as - * the function which generated the initial time stamp. - */ -extern u64 timecounter_read(struct timecounter *tc); - -/** - * timecounter_cyc2time - convert a cycle counter to same - * time base as values returned by - * timecounter_read() - * @tc: Pointer to time counter. - * @cycle_tstamp: a value returned by tc->cc->read() - * - * Cycle counts that are converted correctly as long as they - * fall into the interval [-1/2 max cycle count, +1/2 max cycle count], - * with "max cycle count" == cs->mask+1. - * - * This allows conversion of cycle counter values which were generated - * in the past. - */ -extern u64 timecounter_cyc2time(struct timecounter *tc, - cycle_t cycle_tstamp); - -/** * struct clocksource - hardware abstraction for a free running counter * Provides mostly state-free accessors to the underlying hardware. * This is the structure used for system time. diff --git a/include/linux/mlx4/device.h b/include/linux/mlx4/device.h index 25c791e295fd..f1e41b33462f 100644 --- a/include/linux/mlx4/device.h +++ b/include/linux/mlx4/device.h @@ -42,7 +42,7 @@ #include <linux/atomic.h> -#include <linux/clocksource.h> +#include <linux/timecounter.h> #define MAX_MSIX_P_PORT 17 #define MAX_MSIX 64 diff --git a/include/linux/timecounter.h b/include/linux/timecounter.h new file mode 100644 index 000000000000..74f45496e6d1 --- /dev/null +++ b/include/linux/timecounter.h @@ -0,0 +1,136 @@ +/* + * linux/include/linux/timecounter.h + * + * based on code that migrated away from + * linux/include/linux/clocksource.h + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#ifndef _LINUX_TIMECOUNTER_H +#define _LINUX_TIMECOUNTER_H + +#include <linux/types.h> + +/** + * struct cyclecounter - hardware abstraction for a free running counter + * Provides completely state-free accessors to the underlying hardware. + * Depending on which hardware it reads, the cycle counter may wrap + * around quickly. Locking rules (if necessary) have to be defined + * by the implementor and user of specific instances of this API. + * + * @read: returns the current cycle value + * @mask: bitmask for two's complement + * subtraction of non 64 bit counters, + * see CLOCKSOURCE_MASK() helper macro + * @mult: cycle to nanosecond multiplier + * @shift: cycle to nanosecond divisor (power of two) + */ +struct cyclecounter { + cycle_t (*read)(const struct cyclecounter *cc); + cycle_t mask; + u32 mult; + u32 shift; +}; + +/** + * struct timecounter - layer above a %struct cyclecounter which counts nanoseconds + * Contains the state needed by timecounter_read() to detect + * cycle counter wrap around. Initialize with + * timecounter_init(). Also used to convert cycle counts into the + * corresponding nanosecond counts with timecounter_cyc2time(). Users + * of this code are responsible for initializing the underlying + * cycle counter hardware, locking issues and reading the time + * more often than the cycle counter wraps around. The nanosecond + * counter will only wrap around after ~585 years. + * + * @cc: the cycle counter used by this instance + * @cycle_last: most recent cycle counter value seen by + * timecounter_read() + * @nsec: continuously increasing count + * @mask: bit mask for maintaining the 'frac' field + * @frac: accumulated fractional nanoseconds + */ +struct timecounter { + const struct cyclecounter *cc; + cycle_t cycle_last; + u64 nsec; + u64 mask; + u64 frac; +}; + +/** + * cyclecounter_cyc2ns - converts cycle counter cycles to nanoseconds + * @cc: Pointer to cycle counter. + * @cycles: Cycles + * @mask: bit mask for maintaining the 'frac' field + * @frac: pointer to storage for the fractional nanoseconds. + */ +static inline u64 cyclecounter_cyc2ns(const struct cyclecounter *cc, + cycle_t cycles, u64 mask, u64 *frac) +{ + u64 ns = (u64) cycles; + + ns = (ns * cc->mult) + *frac; + *frac = ns & mask; + return ns >> cc->shift; +} + +/** + * timecounter_adjtime - Shifts the time of the clock. + * @delta: Desired change in nanoseconds. + */ +static inline void timecounter_adjtime(struct timecounter *tc, s64 delta) +{ + tc->nsec += delta; +} + +/** + * timecounter_init - initialize a time counter + * @tc: Pointer to time counter which is to be initialized/reset + * @cc: A cycle counter, ready to be used. + * @start_tstamp: Arbitrary initial time stamp. + * + * After this call the current cycle register (roughly) corresponds to + * the initial time stamp. Every call to timecounter_read() increments + * the time stamp counter by the number of elapsed nanoseconds. + */ +extern void timecounter_init(struct timecounter *tc, + const struct cyclecounter *cc, + u64 start_tstamp); + +/** + * timecounter_read - return nanoseconds elapsed since timecounter_init() + * plus the initial time stamp + * @tc: Pointer to time counter. + * + * In other words, keeps track of time since the same epoch as + * the function which generated the initial time stamp. + */ +extern u64 timecounter_read(struct timecounter *tc); + +/** + * timecounter_cyc2time - convert a cycle counter to same + * time base as values returned by + * timecounter_read() + * @tc: Pointer to time counter. + * @cycle_tstamp: a value returned by tc->cc->read() + * + * Cycle counts that are converted correctly as long as they + * fall into the interval [-1/2 max cycle count, +1/2 max cycle count], + * with "max cycle count" == cs->mask+1. + * + * This allows conversion of cycle counter values which were generated + * in the past. + */ +extern u64 timecounter_cyc2time(struct timecounter *tc, + cycle_t cycle_tstamp); + +#endif diff --git a/include/linux/types.h b/include/linux/types.h index a0bb7048687f..62323825cff9 100644 --- a/include/linux/types.h +++ b/include/linux/types.h @@ -213,5 +213,8 @@ struct callback_head { }; #define rcu_head callback_head +/* clocksource cycle base type */ +typedef u64 cycle_t; + #endif /* __ASSEMBLY__ */ #endif /* _LINUX_TYPES_H */ diff --git a/kernel/time/Makefile b/kernel/time/Makefile index f622cf28628a..c09c07817d7a 100644 --- a/kernel/time/Makefile +++ b/kernel/time/Makefile @@ -1,6 +1,6 @@ obj-y += time.o timer.o hrtimer.o itimer.o posix-timers.o posix-cpu-timers.o obj-y += timekeeping.o ntp.o clocksource.o jiffies.o timer_list.o -obj-y += timeconv.o posix-clock.o alarmtimer.o +obj-y += timeconv.o timecounter.o posix-clock.o alarmtimer.o obj-$(CONFIG_GENERIC_CLOCKEVENTS_BUILD) += clockevents.o obj-$(CONFIG_GENERIC_CLOCKEVENTS) += tick-common.o diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c index b79f39bda7e1..4892352f0e49 100644 --- a/kernel/time/clocksource.c +++ b/kernel/time/clocksource.c @@ -34,82 +34,6 @@ #include "tick-internal.h" #include "timekeeping_internal.h" -void timecounter_init(struct timecounter *tc, - const struct cyclecounter *cc, - u64 start_tstamp) -{ - tc->cc = cc; - tc->cycle_last = cc->read(cc); - tc->nsec = start_tstamp; -} -EXPORT_SYMBOL_GPL(timecounter_init); - -/** - * timecounter_read_delta - get nanoseconds since last call of this function - * @tc: Pointer to time counter - * - * When the underlying cycle counter runs over, this will be handled - * correctly as long as it does not run over more than once between - * calls. - * - * The first call to this function for a new time counter initializes - * the time tracking and returns an undefined result. - */ -static u64 timecounter_read_delta(struct timecounter *tc) -{ - cycle_t cycle_now, cycle_delta; - u64 ns_offset; - - /* read cycle counter: */ - cycle_now = tc->cc->read(tc->cc); - - /* calculate the delta since the last timecounter_read_delta(): */ - cycle_delta = (cycle_now - tc->cycle_last) & tc->cc->mask; - - /* convert to nanoseconds: */ - ns_offset = cyclecounter_cyc2ns(tc->cc, cycle_delta); - - /* update time stamp of timecounter_read_delta() call: */ - tc->cycle_last = cycle_now; - - return ns_offset; -} - -u64 timecounter_read(struct timecounter *tc) -{ - u64 nsec; - - /* increment time by nanoseconds since last call */ - nsec = timecounter_read_delta(tc); - nsec += tc->nsec; - tc->nsec = nsec; - - return nsec; -} -EXPORT_SYMBOL_GPL(timecounter_read); - -u64 timecounter_cyc2time(struct timecounter *tc, - cycle_t cycle_tstamp) -{ - u64 cycle_delta = (cycle_tstamp - tc->cycle_last) & tc->cc->mask; - u64 nsec; - - /* - * Instead of always treating cycle_tstamp as more recent - * than tc->cycle_last, detect when it is too far in the - * future and treat it as old time stamp instead. - */ - if (cycle_delta > tc->cc->mask / 2) { - cycle_delta = (tc->cycle_last - cycle_tstamp) & tc->cc->mask; - nsec = tc->nsec - cyclecounter_cyc2ns(tc->cc, cycle_delta); - } else { - nsec = cyclecounter_cyc2ns(tc->cc, cycle_delta) + tc->nsec; - } - - return nsec; -} -EXPORT_SYMBOL_GPL(timecounter_cyc2time); - /** * clocks_calc_mult_shift - calculate mult/shift factors for scaled math of clocks * @mult: pointer to mult variable diff --git a/kernel/time/timecounter.c b/kernel/time/timecounter.c new file mode 100644 index 000000000000..4687b3104bae --- /dev/null +++ b/kernel/time/timecounter.c @@ -0,0 +1,112 @@ +/* + * linux/kernel/time/timecounter.c + * + * based on code that migrated away from + * linux/kernel/time/clocksource.c + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ + +#include <linux/export.h> +#include <linux/timecounter.h> + +void timecounter_init(struct timecounter *tc, + const struct cyclecounter *cc, + u64 start_tstamp) +{ + tc->cc = cc; + tc->cycle_last = cc->read(cc); + tc->nsec = start_tstamp; + tc->mask = (1ULL << cc->shift) - 1; + tc->frac = 0; +} +EXPORT_SYMBOL_GPL(timecounter_init); + +/** + * timecounter_read_delta - get nanoseconds since last call of this function + * @tc: Pointer to time counter + * + * When the underlying cycle counter runs over, this will be handled + * correctly as long as it does not run over more than once between + * calls. + * + * The first call to this function for a new time counter initializes + * the time tracking and returns an undefined result. + */ +static u64 timecounter_read_delta(struct timecounter *tc) +{ + cycle_t cycle_now, cycle_delta; + u64 ns_offset; + + /* read cycle counter: */ + cycle_now = tc->cc->read(tc->cc); + + /* calculate the delta since the last timecounter_read_delta(): */ + cycle_delta = (cycle_now - tc->cycle_last) & tc->cc->mask; + + /* convert to nanoseconds: */ + ns_offset = cyclecounter_cyc2ns(tc->cc, cycle_delta, + tc->mask, &tc->frac); + + /* update time stamp of timecounter_read_delta() call: */ + tc->cycle_last = cycle_now; + + return ns_offset; +} + +u64 timecounter_read(struct timecounter *tc) +{ + u64 nsec; + + /* increment time by nanoseconds since last call */ + nsec = timecounter_read_delta(tc); + nsec += tc->nsec; + tc->nsec = nsec; + + return nsec; +} +EXPORT_SYMBOL_GPL(timecounter_read); + +/* + * This is like cyclecounter_cyc2ns(), but it is used for computing a + * time previous to the time stored in the cycle counter. + */ +static u64 cc_cyc2ns_backwards(const struct cyclecounter *cc, + cycle_t cycles, u64 mask, u64 frac) +{ + u64 ns = (u64) cycles; + + ns = ((ns * cc->mult) - frac) >> cc->shift; + + return ns; +} + +u64 timecounter_cyc2time(struct timecounter *tc, + cycle_t cycle_tstamp) +{ + u64 delta = (cycle_tstamp - tc->cycle_last) & tc->cc->mask; + u64 nsec = tc->nsec, frac = tc->frac; + + /* + * Instead of always treating cycle_tstamp as more recent + * than tc->cycle_last, detect when it is too far in the + * future and treat it as old time stamp instead. + */ + if (delta > tc->cc->mask / 2) { + delta = (tc->cycle_last - cycle_tstamp) & tc->cc->mask; + nsec -= cc_cyc2ns_backwards(tc->cc, delta, tc->mask, frac); + } else { + nsec += cyclecounter_cyc2ns(tc->cc, delta, tc->mask, &frac); + } + + return nsec; +} +EXPORT_SYMBOL_GPL(timecounter_cyc2time); diff --git a/sound/pci/hda/hda_priv.h b/sound/pci/hda/hda_priv.h index 166e3e84b963..daf458299753 100644 --- a/sound/pci/hda/hda_priv.h +++ b/sound/pci/hda/hda_priv.h @@ -15,7 +15,7 @@ #ifndef __SOUND_HDA_PRIV_H #define __SOUND_HDA_PRIV_H -#include <linux/clocksource.h> +#include <linux/timecounter.h> #include <sound/core.h> #include <sound/pcm.h> diff --git a/virt/kvm/arm/arch_timer.c b/virt/kvm/arm/arch_timer.c index 1c0772b340d8..6e54f3542126 100644 --- a/virt/kvm/arm/arch_timer.c +++ b/virt/kvm/arm/arch_timer.c @@ -152,7 +152,8 @@ void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) return; } - ns = cyclecounter_cyc2ns(timecounter->cc, cval - now); + ns = cyclecounter_cyc2ns(timecounter->cc, cval - now, timecounter->mask, + &timecounter->frac); timer_arm(timer, ns); } |