diff options
author | Shawn Bohrer <sbohrer@rgmadvisors.com> | 2013-12-31 11:39:39 -0600 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-01-02 03:30:36 -0500 |
commit | ad7d4eaed995d76fb24a18e202fdf5072197ff0a (patch) | |
tree | 2625d165dd5b6972f582f19e20cc6c955fd9259a /drivers/net/ethernet/mellanox/mlx4/en_clock.c | |
parent | dd9b45598a7198f8b12965f2ec453bcb5cb90aec (diff) | |
download | op-kernel-dev-ad7d4eaed995d76fb24a18e202fdf5072197ff0a.zip op-kernel-dev-ad7d4eaed995d76fb24a18e202fdf5072197ff0a.tar.gz |
mlx4_en: Add PTP hardware clock
This adds a PHC to the mlx4_en driver. We use reader/writer spinlocks to
protect the timecounter since every packet received needs to call
timecounter_cycle2time() when timestamping is enabled. This can become
a performance bottleneck with RSS and multiple receive queues if normal
spinlocks are used.
This driver has been tested with both Documentation/ptp/testptp and the
linuxptp project (http://linuxptp.sourceforge.net/) on a Mellanox
ConnectX-3 card.
Signed-off-by: Shawn Bohrer <sbohrer@rgmadvisors.com>
Acked-By: Hadar Hen Zion <hadarh@mellanox.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ethernet/mellanox/mlx4/en_clock.c')
-rw-r--r-- | drivers/net/ethernet/mellanox/mlx4/en_clock.c | 194 |
1 files changed, 186 insertions, 8 deletions
diff --git a/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/drivers/net/ethernet/mellanox/mlx4/en_clock.c index fd64410..30712b3 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c @@ -103,19 +103,191 @@ void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev, struct skb_shared_hwtstamps *hwts, u64 timestamp) { + unsigned long flags; u64 nsec; + read_lock_irqsave(&mdev->clock_lock, flags); nsec = timecounter_cyc2time(&mdev->clock, timestamp); + read_unlock_irqrestore(&mdev->clock_lock, flags); memset(hwts, 0, sizeof(struct skb_shared_hwtstamps)); hwts->hwtstamp = ns_to_ktime(nsec); } +/** + * mlx4_en_remove_timestamp - disable PTP device + * @mdev: board private structure + * + * Stop the PTP support. + **/ +void mlx4_en_remove_timestamp(struct mlx4_en_dev *mdev) +{ + if (mdev->ptp_clock) { + ptp_clock_unregister(mdev->ptp_clock); + mdev->ptp_clock = NULL; + mlx4_info(mdev, "removed PHC\n"); + } +} + +void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev) +{ + bool timeout = time_is_before_jiffies(mdev->last_overflow_check + + mdev->overflow_period); + unsigned long flags; + + if (timeout) { + write_lock_irqsave(&mdev->clock_lock, flags); + timecounter_read(&mdev->clock); + write_unlock_irqrestore(&mdev->clock_lock, flags); + mdev->last_overflow_check = jiffies; + } +} + +/** + * mlx4_en_phc_adjfreq - adjust the frequency of the hardware clock + * @ptp: ptp clock structure + * @delta: Desired frequency change in parts per billion + * + * Adjust the frequency of the PHC cycle counter by the indicated delta from + * the base frequency. + **/ +static int mlx4_en_phc_adjfreq(struct ptp_clock_info *ptp, s32 delta) +{ + u64 adj; + u32 diff, mult; + int neg_adj = 0; + unsigned long flags; + struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev, + ptp_clock_info); + + if (delta < 0) { + neg_adj = 1; + delta = -delta; + } + mult = mdev->nominal_c_mult; + adj = mult; + adj *= delta; + diff = div_u64(adj, 1000000000ULL); + + write_lock_irqsave(&mdev->clock_lock, flags); + timecounter_read(&mdev->clock); + mdev->cycles.mult = neg_adj ? mult - diff : mult + diff; + write_unlock_irqrestore(&mdev->clock_lock, flags); + + return 0; +} + +/** + * mlx4_en_phc_adjtime - Shift the time of the hardware clock + * @ptp: ptp clock structure + * @delta: Desired change in nanoseconds + * + * Adjust the timer by resetting the timecounter structure. + **/ +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); + write_unlock_irqrestore(&mdev->clock_lock, flags); + + return 0; +} + +/** + * mlx4_en_phc_gettime - Reads the current time from the hardware clock + * @ptp: ptp clock structure + * @ts: timespec structure to hold the current time value + * + * Read the timecounter and return the correct value in ns after converting + * it into a struct timespec. + **/ +static int mlx4_en_phc_gettime(struct ptp_clock_info *ptp, struct timespec *ts) +{ + struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev, + ptp_clock_info); + unsigned long flags; + u32 remainder; + u64 ns; + + write_lock_irqsave(&mdev->clock_lock, flags); + ns = timecounter_read(&mdev->clock); + write_unlock_irqrestore(&mdev->clock_lock, flags); + + ts->tv_sec = div_u64_rem(ns, NSEC_PER_SEC, &remainder); + ts->tv_nsec = remainder; + + return 0; +} + +/** + * mlx4_en_phc_settime - Set the current time on the hardware clock + * @ptp: ptp clock structure + * @ts: timespec containing the new time for the cycle counter + * + * Reset the timecounter to use a new base value instead of the kernel + * wall timer value. + **/ +static int mlx4_en_phc_settime(struct ptp_clock_info *ptp, + const struct timespec *ts) +{ + struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev, + ptp_clock_info); + u64 ns = timespec_to_ns(ts); + unsigned long flags; + + /* reset the timecounter */ + write_lock_irqsave(&mdev->clock_lock, flags); + timecounter_init(&mdev->clock, &mdev->cycles, ns); + write_unlock_irqrestore(&mdev->clock_lock, flags); + + return 0; +} + +/** + * mlx4_en_phc_enable - enable or disable an ancillary feature + * @ptp: ptp clock structure + * @request: Desired resource to enable or disable + * @on: Caller passes one to enable or zero to disable + * + * Enable (or disable) ancillary features of the PHC subsystem. + * Currently, no ancillary features are supported. + **/ +static int mlx4_en_phc_enable(struct ptp_clock_info __always_unused *ptp, + struct ptp_clock_request __always_unused *request, + int __always_unused on) +{ + return -EOPNOTSUPP; +} + +static const struct ptp_clock_info mlx4_en_ptp_clock_info = { + .owner = THIS_MODULE, + .max_adj = 100000000, + .n_alarm = 0, + .n_ext_ts = 0, + .n_per_out = 0, + .pps = 0, + .adjfreq = mlx4_en_phc_adjfreq, + .adjtime = mlx4_en_phc_adjtime, + .gettime = mlx4_en_phc_gettime, + .settime = mlx4_en_phc_settime, + .enable = mlx4_en_phc_enable, +}; + void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev) { struct mlx4_dev *dev = mdev->dev; + unsigned long flags; u64 ns; + rwlock_init(&mdev->clock_lock); + memset(&mdev->cycles, 0, sizeof(mdev->cycles)); mdev->cycles.read = mlx4_en_read_clock; mdev->cycles.mask = CLOCKSOURCE_MASK(48); @@ -127,9 +299,12 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev) mdev->cycles.shift = 14; mdev->cycles.mult = clocksource_khz2mult(1000 * dev->caps.hca_core_clock, mdev->cycles.shift); + mdev->nominal_c_mult = mdev->cycles.mult; + write_lock_irqsave(&mdev->clock_lock, flags); timecounter_init(&mdev->clock, &mdev->cycles, ktime_to_ns(ktime_get_real())); + write_unlock_irqrestore(&mdev->clock_lock, flags); /* Calculate period in seconds to call the overflow watchdog - to make * sure counter is checked at least once every wrap around. @@ -137,15 +312,18 @@ void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev) ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask); do_div(ns, NSEC_PER_SEC / 2 / HZ); mdev->overflow_period = ns; -} -void mlx4_en_ptp_overflow_check(struct mlx4_en_dev *mdev) -{ - bool timeout = time_is_before_jiffies(mdev->last_overflow_check + - mdev->overflow_period); + /* Configure the PHC */ + mdev->ptp_clock_info = mlx4_en_ptp_clock_info; + snprintf(mdev->ptp_clock_info.name, 16, "mlx4 ptp"); - if (timeout) { - timecounter_read(&mdev->clock); - mdev->last_overflow_check = jiffies; + mdev->ptp_clock = ptp_clock_register(&mdev->ptp_clock_info, + &mdev->pdev->dev); + if (IS_ERR(mdev->ptp_clock)) { + mdev->ptp_clock = NULL; + mlx4_err(mdev, "ptp_clock_register failed\n"); + } else { + mlx4_info(mdev, "registered PHC clock\n"); } + } |