Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / net / ethernet / mellanox / mlx4 / en_clock.c
diff --git a/kernel/drivers/net/ethernet/mellanox/mlx4/en_clock.c b/kernel/drivers/net/ethernet/mellanox/mlx4/en_clock.c
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+/*
+ * Copyright (c) 2012 Mellanox Technologies. All rights reserved.
+ *
+ * This software is available to you under a choice of one of two
+ * licenses.  You may choose to be licensed under the terms of the GNU
+ * General Public License (GPL) Version 2, available from the file
+ * COPYING in the main directory of this source tree, or the
+ * OpenIB.org BSD license below:
+ *
+ *     Redistribution and use in source and binary forms, with or
+ *     without modification, are permitted provided that the following
+ *     conditions are met:
+ *
+ *      - Redistributions of source code must retain the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer.
+ *
+ *      - Redistributions in binary form must reproduce the above
+ *        copyright notice, this list of conditions and the following
+ *        disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ *
+ */
+
+#include <linux/mlx4/device.h>
+#include <linux/clocksource.h>
+
+#include "mlx4_en.h"
+
+/* mlx4_en_read_clock - read raw cycle counter (to be used by time counter)
+ */
+static cycle_t mlx4_en_read_clock(const struct cyclecounter *tc)
+{
+       struct mlx4_en_dev *mdev =
+               container_of(tc, struct mlx4_en_dev, cycles);
+       struct mlx4_dev *dev = mdev->dev;
+
+       return mlx4_read_clock(dev) & tc->mask;
+}
+
+u64 mlx4_en_get_cqe_ts(struct mlx4_cqe *cqe)
+{
+       u64 hi, lo;
+       struct mlx4_ts_cqe *ts_cqe = (struct mlx4_ts_cqe *)cqe;
+
+       lo = (u64)be16_to_cpu(ts_cqe->timestamp_lo);
+       hi = ((u64)be32_to_cpu(ts_cqe->timestamp_hi) + !lo) << 16;
+
+       return hi | lo;
+}
+
+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;
+
+       write_lock_irqsave(&mdev->clock_lock, flags);
+       timecounter_adjtime(&mdev->clock, delta);
+       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 timespec64 *ts)
+{
+       struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
+                                               ptp_clock_info);
+       unsigned long flags;
+       u64 ns;
+
+       write_lock_irqsave(&mdev->clock_lock, flags);
+       ns = timecounter_read(&mdev->clock);
+       write_unlock_irqrestore(&mdev->clock_lock, flags);
+
+       *ts = ns_to_timespec64(ns);
+
+       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 timespec64 *ts)
+{
+       struct mlx4_en_dev *mdev = container_of(ptp, struct mlx4_en_dev,
+                                               ptp_clock_info);
+       u64 ns = timespec64_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,
+       .n_pins         = 0,
+       .pps            = 0,
+       .adjfreq        = mlx4_en_phc_adjfreq,
+       .adjtime        = mlx4_en_phc_adjtime,
+       .gettime64      = mlx4_en_phc_gettime,
+       .settime64      = 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, zero = 0;
+
+       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);
+       /* Using shift to make calculation more accurate. Since current HW
+        * clock frequency is 427 MHz, and cycles are given using a 48 bits
+        * register, the biggest shift when calculating using u64, is 14
+        * (max_cycles * multiplier < 2^64)
+        */
+       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.
+        */
+       ns = cyclecounter_cyc2ns(&mdev->cycles, mdev->cycles.mask, zero, &zero);
+       do_div(ns, NSEC_PER_SEC / 2 / HZ);
+       mdev->overflow_period = ns;
+
+       /* Configure the PHC */
+       mdev->ptp_clock_info = mlx4_en_ptp_clock_info;
+       snprintf(mdev->ptp_clock_info.name, 16, "mlx4 ptp");
+
+       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");
+       }
+
+}