- 根目录:
- drivers
- net
- ethernet
- mellanox
- mlx4
- en_clock.c
/*
* 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");
}
}