linux/drivers/net/ethernet/cadence/macb_ptp.c
Harini Katakam 64d7839af8 net: macb: Fix ptp time adjustment for large negative delta
When delta passed to gem_ptp_adjtime is negative, the sign is
maintained in the ns_to_timespec64 conversion. Hence timespec_add
should be used directly. timespec_sub will just subtract the negative
value thus increasing the time difference.

Signed-off-by: Harini Katakam <harini.katakam@xilinx.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2018-06-21 15:01:06 +09:00

516 lines
14 KiB
C

/**
* 1588 PTP support for Cadence GEM device.
*
* Copyright (C) 2017 Cadence Design Systems - http://www.cadence.com
*
* Authors: Rafal Ozieblo <rafalo@cadence.com>
* Bartosz Folta <bfolta@cadence.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 of
* the License as published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/clk.h>
#include <linux/device.h>
#include <linux/etherdevice.h>
#include <linux/platform_device.h>
#include <linux/time64.h>
#include <linux/ptp_classify.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/net_tstamp.h>
#include <linux/circ_buf.h>
#include <linux/spinlock.h>
#include "macb.h"
#define GEM_PTP_TIMER_NAME "gem-ptp-timer"
static struct macb_dma_desc_ptp *macb_ptp_desc(struct macb *bp,
struct macb_dma_desc *desc)
{
if (bp->hw_dma_cap == HW_DMA_CAP_PTP)
return (struct macb_dma_desc_ptp *)
((u8 *)desc + sizeof(struct macb_dma_desc));
if (bp->hw_dma_cap == HW_DMA_CAP_64B_PTP)
return (struct macb_dma_desc_ptp *)
((u8 *)desc + sizeof(struct macb_dma_desc)
+ sizeof(struct macb_dma_desc_64));
return NULL;
}
static int gem_tsu_get_time(struct ptp_clock_info *ptp, struct timespec64 *ts)
{
struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
unsigned long flags;
long first, second;
u32 secl, sech;
spin_lock_irqsave(&bp->tsu_clk_lock, flags);
first = gem_readl(bp, TN);
secl = gem_readl(bp, TSL);
sech = gem_readl(bp, TSH);
second = gem_readl(bp, TN);
/* test for nsec rollover */
if (first > second) {
/* if so, use later read & re-read seconds
* (assume all done within 1s)
*/
ts->tv_nsec = gem_readl(bp, TN);
secl = gem_readl(bp, TSL);
sech = gem_readl(bp, TSH);
} else {
ts->tv_nsec = first;
}
spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
ts->tv_sec = (((u64)sech << GEM_TSL_SIZE) | secl)
& TSU_SEC_MAX_VAL;
return 0;
}
static int gem_tsu_set_time(struct ptp_clock_info *ptp,
const struct timespec64 *ts)
{
struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
unsigned long flags;
u32 ns, sech, secl;
secl = (u32)ts->tv_sec;
sech = (ts->tv_sec >> GEM_TSL_SIZE) & ((1 << GEM_TSH_SIZE) - 1);
ns = ts->tv_nsec;
spin_lock_irqsave(&bp->tsu_clk_lock, flags);
/* TSH doesn't latch the time and no atomicity! */
gem_writel(bp, TN, 0); /* clear to avoid overflow */
gem_writel(bp, TSH, sech);
/* write lower bits 2nd, for synchronized secs update */
gem_writel(bp, TSL, secl);
gem_writel(bp, TN, ns);
spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
return 0;
}
static int gem_tsu_incr_set(struct macb *bp, struct tsu_incr *incr_spec)
{
unsigned long flags;
/* tsu_timer_incr register must be written after
* the tsu_timer_incr_sub_ns register and the write operation
* will cause the value written to the tsu_timer_incr_sub_ns register
* to take effect.
*/
spin_lock_irqsave(&bp->tsu_clk_lock, flags);
gem_writel(bp, TISUBN, GEM_BF(SUBNSINCR, incr_spec->sub_ns));
gem_writel(bp, TI, GEM_BF(NSINCR, incr_spec->ns));
spin_unlock_irqrestore(&bp->tsu_clk_lock, flags);
return 0;
}
static int gem_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
{
struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
struct tsu_incr incr_spec;
bool neg_adj = false;
u32 word;
u64 adj;
if (scaled_ppm < 0) {
neg_adj = true;
scaled_ppm = -scaled_ppm;
}
/* Adjustment is relative to base frequency */
incr_spec.sub_ns = bp->tsu_incr.sub_ns;
incr_spec.ns = bp->tsu_incr.ns;
/* scaling: unused(8bit) | ns(8bit) | fractions(16bit) */
word = ((u64)incr_spec.ns << GEM_SUBNSINCR_SIZE) + incr_spec.sub_ns;
adj = (u64)scaled_ppm * word;
/* Divide with rounding, equivalent to floating dividing:
* (temp / USEC_PER_SEC) + 0.5
*/
adj += (USEC_PER_SEC >> 1);
adj >>= GEM_SUBNSINCR_SIZE; /* remove fractions */
adj = div_u64(adj, USEC_PER_SEC);
adj = neg_adj ? (word - adj) : (word + adj);
incr_spec.ns = (adj >> GEM_SUBNSINCR_SIZE)
& ((1 << GEM_NSINCR_SIZE) - 1);
incr_spec.sub_ns = adj & ((1 << GEM_SUBNSINCR_SIZE) - 1);
gem_tsu_incr_set(bp, &incr_spec);
return 0;
}
static int gem_ptp_adjtime(struct ptp_clock_info *ptp, s64 delta)
{
struct macb *bp = container_of(ptp, struct macb, ptp_clock_info);
struct timespec64 now, then = ns_to_timespec64(delta);
u32 adj, sign = 0;
if (delta < 0) {
sign = 1;
delta = -delta;
}
if (delta > TSU_NSEC_MAX_VAL) {
gem_tsu_get_time(&bp->ptp_clock_info, &now);
now = timespec64_add(now, then);
gem_tsu_set_time(&bp->ptp_clock_info,
(const struct timespec64 *)&now);
} else {
adj = (sign << GEM_ADDSUB_OFFSET) | delta;
gem_writel(bp, TA, adj);
}
return 0;
}
static int gem_ptp_enable(struct ptp_clock_info *ptp,
struct ptp_clock_request *rq, int on)
{
return -EOPNOTSUPP;
}
static const struct ptp_clock_info gem_ptp_caps_template = {
.owner = THIS_MODULE,
.name = GEM_PTP_TIMER_NAME,
.max_adj = 0,
.n_alarm = 0,
.n_ext_ts = 0,
.n_per_out = 0,
.n_pins = 0,
.pps = 1,
.adjfine = gem_ptp_adjfine,
.adjtime = gem_ptp_adjtime,
.gettime64 = gem_tsu_get_time,
.settime64 = gem_tsu_set_time,
.enable = gem_ptp_enable,
};
static void gem_ptp_init_timer(struct macb *bp)
{
u32 rem = 0;
u64 adj;
bp->tsu_incr.ns = div_u64_rem(NSEC_PER_SEC, bp->tsu_rate, &rem);
if (rem) {
adj = rem;
adj <<= GEM_SUBNSINCR_SIZE;
bp->tsu_incr.sub_ns = div_u64(adj, bp->tsu_rate);
} else {
bp->tsu_incr.sub_ns = 0;
}
}
static void gem_ptp_init_tsu(struct macb *bp)
{
struct timespec64 ts;
/* 1. get current system time */
ts = ns_to_timespec64(ktime_to_ns(ktime_get_real()));
/* 2. set ptp timer */
gem_tsu_set_time(&bp->ptp_clock_info, &ts);
/* 3. set PTP timer increment value to BASE_INCREMENT */
gem_tsu_incr_set(bp, &bp->tsu_incr);
gem_writel(bp, TA, 0);
}
static void gem_ptp_clear_timer(struct macb *bp)
{
bp->tsu_incr.sub_ns = 0;
bp->tsu_incr.ns = 0;
gem_writel(bp, TISUBN, GEM_BF(SUBNSINCR, 0));
gem_writel(bp, TI, GEM_BF(NSINCR, 0));
gem_writel(bp, TA, 0);
}
static int gem_hw_timestamp(struct macb *bp, u32 dma_desc_ts_1,
u32 dma_desc_ts_2, struct timespec64 *ts)
{
struct timespec64 tsu;
ts->tv_sec = (GEM_BFEXT(DMA_SECH, dma_desc_ts_2) << GEM_DMA_SECL_SIZE) |
GEM_BFEXT(DMA_SECL, dma_desc_ts_1);
ts->tv_nsec = GEM_BFEXT(DMA_NSEC, dma_desc_ts_1);
/* TSU overlapping workaround
* The timestamp only contains lower few bits of seconds,
* so add value from 1588 timer
*/
gem_tsu_get_time(&bp->ptp_clock_info, &tsu);
/* If the top bit is set in the timestamp,
* but not in 1588 timer, it has rolled over,
* so subtract max size
*/
if ((ts->tv_sec & (GEM_DMA_SEC_TOP >> 1)) &&
!(tsu.tv_sec & (GEM_DMA_SEC_TOP >> 1)))
ts->tv_sec -= GEM_DMA_SEC_TOP;
ts->tv_sec += ((~GEM_DMA_SEC_MASK) & tsu.tv_sec);
return 0;
}
void gem_ptp_rxstamp(struct macb *bp, struct sk_buff *skb,
struct macb_dma_desc *desc)
{
struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
struct macb_dma_desc_ptp *desc_ptp;
struct timespec64 ts;
if (GEM_BFEXT(DMA_RXVALID, desc->addr)) {
desc_ptp = macb_ptp_desc(bp, desc);
gem_hw_timestamp(bp, desc_ptp->ts_1, desc_ptp->ts_2, &ts);
memset(shhwtstamps, 0, sizeof(struct skb_shared_hwtstamps));
shhwtstamps->hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
}
}
static void gem_tstamp_tx(struct macb *bp, struct sk_buff *skb,
struct macb_dma_desc_ptp *desc_ptp)
{
struct skb_shared_hwtstamps shhwtstamps;
struct timespec64 ts;
gem_hw_timestamp(bp, desc_ptp->ts_1, desc_ptp->ts_2, &ts);
memset(&shhwtstamps, 0, sizeof(shhwtstamps));
shhwtstamps.hwtstamp = ktime_set(ts.tv_sec, ts.tv_nsec);
skb_tstamp_tx(skb, &shhwtstamps);
}
int gem_ptp_txstamp(struct macb_queue *queue, struct sk_buff *skb,
struct macb_dma_desc *desc)
{
unsigned long tail = READ_ONCE(queue->tx_ts_tail);
unsigned long head = queue->tx_ts_head;
struct macb_dma_desc_ptp *desc_ptp;
struct gem_tx_ts *tx_timestamp;
if (!GEM_BFEXT(DMA_TXVALID, desc->ctrl))
return -EINVAL;
if (CIRC_SPACE(head, tail, PTP_TS_BUFFER_SIZE) == 0)
return -ENOMEM;
skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
desc_ptp = macb_ptp_desc(queue->bp, desc);
tx_timestamp = &queue->tx_timestamps[head];
tx_timestamp->skb = skb;
tx_timestamp->desc_ptp.ts_1 = desc_ptp->ts_1;
tx_timestamp->desc_ptp.ts_2 = desc_ptp->ts_2;
/* move head */
smp_store_release(&queue->tx_ts_head,
(head + 1) & (PTP_TS_BUFFER_SIZE - 1));
schedule_work(&queue->tx_ts_task);
return 0;
}
static void gem_tx_timestamp_flush(struct work_struct *work)
{
struct macb_queue *queue =
container_of(work, struct macb_queue, tx_ts_task);
unsigned long head, tail;
struct gem_tx_ts *tx_ts;
/* take current head */
head = smp_load_acquire(&queue->tx_ts_head);
tail = queue->tx_ts_tail;
while (CIRC_CNT(head, tail, PTP_TS_BUFFER_SIZE)) {
tx_ts = &queue->tx_timestamps[tail];
gem_tstamp_tx(queue->bp, tx_ts->skb, &tx_ts->desc_ptp);
/* cleanup */
dev_kfree_skb_any(tx_ts->skb);
/* remove old tail */
smp_store_release(&queue->tx_ts_tail,
(tail + 1) & (PTP_TS_BUFFER_SIZE - 1));
tail = queue->tx_ts_tail;
}
}
void gem_ptp_init(struct net_device *dev)
{
struct macb *bp = netdev_priv(dev);
struct macb_queue *queue;
unsigned int q;
bp->ptp_clock_info = gem_ptp_caps_template;
/* nominal frequency and maximum adjustment in ppb */
bp->tsu_rate = bp->ptp_info->get_tsu_rate(bp);
bp->ptp_clock_info.max_adj = bp->ptp_info->get_ptp_max_adj();
gem_ptp_init_timer(bp);
bp->ptp_clock = ptp_clock_register(&bp->ptp_clock_info, &dev->dev);
if (IS_ERR(bp->ptp_clock)) {
pr_err("ptp clock register failed: %ld\n",
PTR_ERR(bp->ptp_clock));
bp->ptp_clock = NULL;
return;
} else if (bp->ptp_clock == NULL) {
pr_err("ptp clock register failed\n");
return;
}
spin_lock_init(&bp->tsu_clk_lock);
for (q = 0, queue = bp->queues; q < bp->num_queues; ++q, ++queue) {
queue->tx_ts_head = 0;
queue->tx_ts_tail = 0;
INIT_WORK(&queue->tx_ts_task, gem_tx_timestamp_flush);
}
gem_ptp_init_tsu(bp);
dev_info(&bp->pdev->dev, "%s ptp clock registered.\n",
GEM_PTP_TIMER_NAME);
}
void gem_ptp_remove(struct net_device *ndev)
{
struct macb *bp = netdev_priv(ndev);
if (bp->ptp_clock)
ptp_clock_unregister(bp->ptp_clock);
gem_ptp_clear_timer(bp);
dev_info(&bp->pdev->dev, "%s ptp clock unregistered.\n",
GEM_PTP_TIMER_NAME);
}
static int gem_ptp_set_ts_mode(struct macb *bp,
enum macb_bd_control tx_bd_control,
enum macb_bd_control rx_bd_control)
{
gem_writel(bp, TXBDCTRL, GEM_BF(TXTSMODE, tx_bd_control));
gem_writel(bp, RXBDCTRL, GEM_BF(RXTSMODE, rx_bd_control));
return 0;
}
int gem_get_hwtst(struct net_device *dev, struct ifreq *rq)
{
struct hwtstamp_config *tstamp_config;
struct macb *bp = netdev_priv(dev);
tstamp_config = &bp->tstamp_config;
if ((bp->hw_dma_cap & HW_DMA_CAP_PTP) == 0)
return -EOPNOTSUPP;
if (copy_to_user(rq->ifr_data, tstamp_config, sizeof(*tstamp_config)))
return -EFAULT;
else
return 0;
}
static int gem_ptp_set_one_step_sync(struct macb *bp, u8 enable)
{
u32 reg_val;
reg_val = macb_readl(bp, NCR);
if (enable)
macb_writel(bp, NCR, reg_val | MACB_BIT(OSSMODE));
else
macb_writel(bp, NCR, reg_val & ~MACB_BIT(OSSMODE));
return 0;
}
int gem_set_hwtst(struct net_device *dev, struct ifreq *ifr, int cmd)
{
enum macb_bd_control tx_bd_control = TSTAMP_DISABLED;
enum macb_bd_control rx_bd_control = TSTAMP_DISABLED;
struct hwtstamp_config *tstamp_config;
struct macb *bp = netdev_priv(dev);
u32 regval;
tstamp_config = &bp->tstamp_config;
if ((bp->hw_dma_cap & HW_DMA_CAP_PTP) == 0)
return -EOPNOTSUPP;
if (copy_from_user(tstamp_config, ifr->ifr_data,
sizeof(*tstamp_config)))
return -EFAULT;
/* reserved for future extensions */
if (tstamp_config->flags)
return -EINVAL;
switch (tstamp_config->tx_type) {
case HWTSTAMP_TX_OFF:
break;
case HWTSTAMP_TX_ONESTEP_SYNC:
if (gem_ptp_set_one_step_sync(bp, 1) != 0)
return -ERANGE;
case HWTSTAMP_TX_ON:
tx_bd_control = TSTAMP_ALL_FRAMES;
break;
default:
return -ERANGE;
}
switch (tstamp_config->rx_filter) {
case HWTSTAMP_FILTER_NONE:
break;
case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
break;
case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
break;
case HWTSTAMP_FILTER_PTP_V2_EVENT:
case HWTSTAMP_FILTER_PTP_V2_L2_EVENT:
case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
case HWTSTAMP_FILTER_PTP_V2_SYNC:
case HWTSTAMP_FILTER_PTP_V2_L2_SYNC:
case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
case HWTSTAMP_FILTER_PTP_V2_L2_DELAY_REQ:
case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
rx_bd_control = TSTAMP_ALL_PTP_FRAMES;
tstamp_config->rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
regval = macb_readl(bp, NCR);
macb_writel(bp, NCR, (regval | MACB_BIT(SRTSM)));
break;
case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
case HWTSTAMP_FILTER_ALL:
rx_bd_control = TSTAMP_ALL_FRAMES;
tstamp_config->rx_filter = HWTSTAMP_FILTER_ALL;
break;
default:
tstamp_config->rx_filter = HWTSTAMP_FILTER_NONE;
return -ERANGE;
}
if (gem_ptp_set_ts_mode(bp, tx_bd_control, rx_bd_control) != 0)
return -ERANGE;
if (copy_to_user(ifr->ifr_data, tstamp_config, sizeof(*tstamp_config)))
return -EFAULT;
else
return 0;
}