From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hadar Hen Zion Subject: Re: [PATCH net-next 1/2] mlx4_en: Add PTP hardware clock Date: Sun, 22 Dec 2013 15:13:12 +0200 Message-ID: <52B6E568.4030400@mellanox.com> References: <1387312359-9476-1-git-send-email-shawn.bohrer@gmail.com> <1387312359-9476-2-git-send-email-shawn.bohrer@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: "David S. Miller" , Or Gerlitz , Amir Vadai , Richard Cochran , , , Shawn Bohrer To: Shawn Bohrer Return-path: Received: from eu1sys200aog101.obsmtp.com ([207.126.144.111]:47237 "EHLO eu1sys200aog101.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752290Ab3LVNO2 (ORCPT ); Sun, 22 Dec 2013 08:14:28 -0500 In-Reply-To: <1387312359-9476-2-git-send-email-shawn.bohrer@gmail.com> Sender: netdev-owner@vger.kernel.org List-ID: On 12/17/2013 10:32 PM, Shawn Bohrer wrote: > From: Shawn Bohrer > > This adds a PHC to the mlx4_en driver. The code is largely based off of > the e1000e driver (drivers/net/ethernet/intel/e1000e/ptp.c) which seemed > very similar. > > This driver has been tested with both Documentation/ptp/testptp and the > linuxptp project (http://linuxptp.sourceforge.net/) and appears to work > on a Mellanox ConnectX-3 card. > > Signed-off-by: Shawn Bohrer > --- > drivers/net/ethernet/mellanox/mlx4/en_clock.c | 192 ++++++++++++++++++++++- > drivers/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, 196 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..9b0d515 100644 > --- a/drivers/net/ethernet/mellanox/mlx4/en_clock.c > +++ b/drivers/net/ethernet/mellanox/mlx4/en_clock.c > @@ -103,17 +103,187 @@ void mlx4_en_fill_hwtstamps(struct mlx4_en_dev *mdev, > struct skb_shared_hwtstamps *hwts, > u64 timestamp) > { > + unsigned long flags; > u64 nsec; > > + spin_lock_irqsave(&mdev->clock_lock, flags); 1. Missing initialization for clock_lock 2. Adding spin lock in the data path reduce performance by 15% when HW timestamping is enabled. I did some testing and replacing spin_lock_irqsave with read/write_lock_irqsave prevents the performance decrease. Thanks, Hadar > nsec = timecounter_cyc2time(&mdev->clock, timestamp); > + spin_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) { > + spin_lock_irqsave(&mdev->clock_lock, flags); > + timecounter_read(&mdev->clock); > + spin_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); > + > + spin_lock_irqsave(&mdev->clock_lock, flags); > + timecounter_read(&mdev->clock); > + mdev->cycles.mult = neg_adj ? mult - diff : mult + diff; > + spin_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; > + > + spin_lock_irqsave(&mdev->clock_lock, flags); > + now = timecounter_read(&mdev->clock); > + now += delta; > + timecounter_init(&mdev->clock, &mdev->cycles, now); > + spin_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; > + > + spin_lock_irqsave(&mdev->clock_lock, flags); > + ns = timecounter_read(&mdev->clock); > + spin_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 */ > + spin_lock_irqsave(&mdev->clock_lock, flags); > + timecounter_init(&mdev->clock, &mdev->cycles, ns); > + spin_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; > > memset(&mdev->cycles, 0, sizeof(mdev->cycles)); > @@ -127,9 +297,12 @@ 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; > > + spin_lock_irqsave(&mdev->clock_lock, flags); > timecounter_init(&mdev->clock, &mdev->cycles, > ktime_to_ns(ktime_get_real())); > + spin_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 +310,18 @@ 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 0596f9f..3e8d336 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 0d087b0..6268057 100644 > --- a/drivers/net/ethernet/mellanox/mlx4/en_main.c > +++ b/drivers/net/ethernet/mellanox/mlx4/en_main.c > @@ -196,6 +196,9 @@ 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 f3758de..2b4083f 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 > @@ -373,10 +374,14 @@ struct mlx4_en_dev { > u32 priv_pdn; > spinlock_t uar_lock; > u8 mac_removed[MLX4_MAX_PORTS + 1]; > + spinlock_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; > }; > > > @@ -786,6 +791,7 @@ 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); >