From ad7d4eaed995d76fb24a18e202fdf5072197ff0a Mon Sep 17 00:00:00 2001 From: Shawn Bohrer Date: Tue, 31 Dec 2013 11:39:39 -0600 Subject: [PATCH] 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 Acked-By: Hadar Hen Zion Acked-by: Richard Cochran Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlx4/en_clock.c | 194 +++++++++++++++++- .../net/ethernet/mellanox/mlx4/en_ethtool.c | 3 + drivers/net/ethernet/mellanox/mlx4/en_main.c | 3 + drivers/net/ethernet/mellanox/mlx4/mlx4_en.h | 6 + 4 files changed, 198 insertions(+), 8 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/drivers/net/ethernet/mellanox/mlx4/en_clock.c index fd6441071319..30712b36f43c 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"); } + } diff --git a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c index 0596f9f85a0e..3e8d33605fe7 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_ethtool.c @@ -1193,6 +1193,9 @@ static int mlx4_en_get_ts_info(struct net_device *dev, info->rx_filters = (1 << HWTSTAMP_FILTER_NONE) | (1 << HWTSTAMP_FILTER_ALL); + + if (mdev->ptp_clock) + info->phc_index = ptp_clock_index(mdev->ptp_clock); } return ret; diff --git a/drivers/net/ethernet/mellanox/mlx4/en_main.c b/drivers/net/ethernet/mellanox/mlx4/en_main.c index 725a4e1b5f67..d357bf5a4686 100644 --- a/drivers/net/ethernet/mellanox/mlx4/en_main.c +++ b/drivers/net/ethernet/mellanox/mlx4/en_main.c @@ -199,6 +199,9 @@ static void mlx4_en_remove(struct mlx4_dev *dev, void *endev_ptr) if (mdev->pndev[i]) mlx4_en_destroy_netdev(mdev->pndev[i]); + if (mdev->dev->caps.flags2 & MLX4_DEV_CAP_FLAG2_TS) + mlx4_en_remove_timestamp(mdev); + flush_workqueue(mdev->workqueue); destroy_workqueue(mdev->workqueue); (void) mlx4_mr_free(dev, &mdev->mr); diff --git a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h index 766691c66111..2f1e200f2e4c 100644 --- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h +++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h @@ -45,6 +45,7 @@ #include #endif #include +#include #include #include @@ -375,10 +376,14 @@ struct mlx4_en_dev { u32 priv_pdn; spinlock_t uar_lock; u8 mac_removed[MLX4_MAX_PORTS + 1]; + rwlock_t clock_lock; + u32 nominal_c_mult; struct cyclecounter cycles; struct timecounter clock; unsigned long last_overflow_check; unsigned long overflow_period; + struct ptp_clock *ptp_clock; + struct ptp_clock_info ptp_clock_info; }; @@ -791,6 +796,7 @@ void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev, struct skb_shared_hwtstamps *hwts, u64 timestamp); void mlx4_en_init_timestamp(struct mlx4_en_dev *mdev); +void mlx4_en_remove_timestamp(struct mlx4_en_dev *mdev); int mlx4_en_timestamp_config(struct net_device *dev, int tx_type, int rx_filter); -- 2.30.2