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Date: Tue, 31 Dec 2013 11:39:39 -0600
From: Shawn Bohrer <shawn.bohrer@...il.com>
To: "David S. Miller" <davem@...emloft.net>
Cc: Or Gerlitz <ogerlitz@...lanox.com>,
Amir Vadai <amirv@...lanox.com>,
Richard Cochran <richardcochran@...il.com>,
netdev@...r.kernel.org, tomk@...advisors.com,
Hadar Hen Zion <hadarh@...lanox.com>,
Shawn Bohrer <sbohrer@...advisors.com>
Subject: [PATCH net-next v4 1/2] mlx4_en: Add PTP hardware clock
From: Shawn Bohrer <sbohrer@...advisors.com>
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@...advisors.com>
---
drivers/net/ethernet/mellanox/mlx4/en_clock.c | 194 ++++++++++++++++++++++-
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, 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 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");
}
+
}
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 725a4e1..d357bf5 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 123714c..298ce22 100644
--- a/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
+++ b/drivers/net/ethernet/mellanox/mlx4/mlx4_en.h
@@ -45,6 +45,7 @@
#include <linux/dcbnl.h>
#endif
#include <linux/cpu_rmap.h>
+#include <linux/ptp_clock_kernel.h>
#include <linux/mlx4/device.h>
#include <linux/mlx4/qp.h>
@@ -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;
};
@@ -790,6 +795,7 @@ 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);
--
1.7.7.6
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