@@ -2301,6 +2301,7 @@ static const struct dsa_switch_ops b53_switch_ops = {
.port_change_mtu = b53_change_mtu,
.get_ts_info = b53_get_ts_info,
.port_rxtstamp = b53_port_rxtstamp,
+ .port_txtstamp = b53_port_txtstamp,
};
struct b53_chip_data {
@@ -109,6 +109,64 @@ static void b53_ptp_overflow_check(struct work_struct *work)
schedule_delayed_work(&dev->overflow_work, B53_PTP_OVERFLOW_PERIOD);
}
+static long b53_hwtstamp_work(struct ptp_clock_info *ptp)
+{
+ struct b53_device *dev =
+ container_of(ptp, struct b53_device, ptp_clock_info);
+ struct dsa_switch *ds = dev->ds;
+ int i;
+
+ for (i = 0; i < ds->num_ports; i++) {
+ struct b53_port_hwtstamp *ps;
+
+ if (!dsa_is_user_port(ds, i))
+ continue;
+
+ ps = &dev->ports[i].port_hwtstamp;
+
+ if (test_bit(B53_HWTSTAMP_TX_IN_PROGRESS, &ps->state) &&
+ time_is_before_jiffies(ps->tx_tstamp_start +
+ TX_TSTAMP_TIMEOUT)) {
+ dev_err(dev->dev,
+ "Timeout while waiting for Tx timestamp!\n");
+ dev_kfree_skb_any(ps->tx_skb);
+ ps->tx_skb = NULL;
+ clear_bit_unlock(B53_HWTSTAMP_TX_IN_PROGRESS,
+ &ps->state);
+ }
+ }
+
+ return -1;
+}
+
+void b53_port_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb)
+{
+ struct b53_device *dev = ds->priv;
+ struct b53_port_hwtstamp *ps = &dev->ports[port].port_hwtstamp;
+ struct sk_buff *clone;
+ unsigned int type;
+
+ type = ptp_classify_raw(skb);
+
+ if (type != PTP_CLASS_V2_L2)
+ return;
+
+ if (!test_bit(B53_HWTSTAMP_ENABLED, &ps->state))
+ return;
+
+ clone = skb_clone_sk(skb);
+ if (!clone)
+ return;
+
+ if (test_and_set_bit_lock(B53_HWTSTAMP_TX_IN_PROGRESS, &ps->state)) {
+ kfree_skb(clone);
+ return;
+ }
+
+ ps->tx_skb = clone;
+ ps->tx_tstamp_start = jiffies;
+}
+
bool b53_port_rxtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb,
unsigned int type)
{
@@ -172,6 +230,7 @@ int b53_ptp_init(struct b53_device *dev)
dev->ptp_clock_info.gettime64 = b53_ptp_gettime;
dev->ptp_clock_info.settime64 = b53_ptp_settime;
dev->ptp_clock_info.enable = b53_ptp_enable;
+ dev->ptp_clock_info.do_aux_work = b53_hwtstamp_work;
dev->ptp_clock = ptp_clock_register(&dev->ptp_clock_info, dev->dev);
if (IS_ERR(dev->ptp_clock))
@@ -10,6 +10,7 @@
#include "b53_priv.h"
#define SKB_PTP_TYPE(__skb) (*(unsigned int *)((__skb)->cb))
+#define TX_TSTAMP_TIMEOUT msecs_to_jiffies(40)
#ifdef CONFIG_B53_PTP
int b53_ptp_init(struct b53_device *dev);
@@ -18,6 +19,8 @@ int b53_get_ts_info(struct dsa_switch *ds, int port,
struct ethtool_ts_info *info);
bool b53_port_rxtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb,
unsigned int type);
+void b53_port_txtstamp(struct dsa_switch *ds, int port, struct sk_buff *skb);
+
#else /* !CONFIG_B53_PTP */
static inline int b53_ptp_init(struct b53_device *dev)
@@ -41,5 +44,11 @@ static inline bool b53_port_rxtstamp(struct dsa_switch *ds, int port,
return false;
}
+static inline bool b53_port_txtstamp(struct dsa_switch *ds, int port,
+ struct sk_buff *skb)
+{
+ return false;
+}
+
#endif
#endif
@@ -8,6 +8,7 @@
#include <linux/dsa/brcm.h>
#include <linux/etherdevice.h>
#include <linux/list.h>
+#include <linux/ptp_classify.h>
#include <linux/slab.h>
#include <linux/dsa/b53.h>
@@ -85,9 +86,14 @@ static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb,
unsigned int offset)
{
struct dsa_port *dp = dsa_slave_to_port(dev);
+ struct b53_device *b53_dev = dp->ds->priv;
+ unsigned int type = ptp_classify_raw(skb);
u16 queue = skb_get_queue_mapping(skb);
+ struct b53_port_hwtstamp *ps;
u8 *brcm_tag;
+ ps = &b53_dev->ports[dp->index].port_hwtstamp;
+
/* The Ethernet switch we are interfaced with needs packets to be at
* least 64 bytes (including FCS) otherwise they will be discarded when
* they enter the switch port logic. When Broadcom tags are enabled, we
@@ -112,7 +118,13 @@ static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb,
*/
brcm_tag[0] = (1 << BRCM_OPCODE_SHIFT) |
((queue & BRCM_IG_TC_MASK) << BRCM_IG_TC_SHIFT);
+
brcm_tag[1] = 0;
+
+ if (type == PTP_CLASS_V2_L2 &&
+ test_bit(B53_HWTSTAMP_TX_IN_PROGRESS, &ps->state))
+ brcm_tag[1] = 1 << BRCM_IG_TS_SHIFT;
+
brcm_tag[2] = 0;
if (dp->index == 8)
brcm_tag[2] = BRCM_IG_DSTMAP2_MASK;
@@ -126,6 +138,32 @@ static struct sk_buff *brcm_tag_xmit_ll(struct sk_buff *skb,
return skb;
}
+static int set_txtstamp(struct b53_device *dev,
+ struct b53_port_hwtstamp *ps,
+ int port,
+ u64 ns)
+{
+ struct skb_shared_hwtstamps shhwtstamps;
+ struct sk_buff *tmp_skb;
+
+ if (!ps->tx_skb)
+ return 0;
+
+ mutex_lock(&dev->ptp_mutex);
+ ns = timecounter_cyc2time(&dev->tc, ns);
+ mutex_unlock(&dev->ptp_mutex);
+
+ memset(&shhwtstamps, 0, sizeof(shhwtstamps));
+ shhwtstamps.hwtstamp = ns_to_ktime(ns);
+ tmp_skb = ps->tx_skb;
+ ps->tx_skb = NULL;
+
+ clear_bit_unlock(B53_HWTSTAMP_TX_IN_PROGRESS, &ps->state);
+ skb_complete_tx_timestamp(tmp_skb, &shhwtstamps);
+
+ return 0;
+}
+
/* Frames with this tag have one of these two layouts:
* -----------------------------------
* | MAC DA | MAC SA | 4b tag | Type | DSA_TAG_PROTO_BRCM
@@ -143,6 +181,9 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb,
unsigned int offset,
int *tag_len)
{
+ struct b53_port_hwtstamp *ps;
+ struct b53_device *b53_dev;
+ struct dsa_port *dp;
int source_port;
u8 *brcm_tag;
u32 tstamp;
@@ -174,6 +215,16 @@ static struct sk_buff *brcm_tag_rcv_ll(struct sk_buff *skb,
if (!skb->dev)
return NULL;
+ /* Check whether this is a status frame */
+ if (*tag_len == 8 && brcm_tag[3] & 0x20) {
+ dp = dsa_slave_to_port(skb->dev);
+ b53_dev = dp->ds->priv;
+ ps = &b53_dev->ports[source_port].port_hwtstamp;
+
+ set_txtstamp(b53_dev, ps, source_port, tstamp);
+ return NULL;
+ }
+
/* Remove Broadcom tag and update checksum */
skb_pull_rcsum(skb, *tag_len);
In order to get the switch to generate a timestamp for a transmitted packet, we need to set the TS bit in the BRCM tag. The switch will then create a status frame, which gets send back to the cpu. In b53_port_txtstamp() we put the skb into a waiting position. When a status frame is received, we extract the timestamp and put the time according to our timecounter into the waiting skb. When TX_TSTAMP_TIMEOUT is reached and we have no means to correctly get back a full timestamp, we cancel the process. As the status frame doesn't contain a reference to the original packet, only one packet with timestamp request can be sent at a time. Signed-off-by: Martin Kaistra <martin.kaistra@linutronix.de> --- drivers/net/dsa/b53/b53_common.c | 1 + drivers/net/dsa/b53/b53_ptp.c | 59 ++++++++++++++++++++++++++++++++ drivers/net/dsa/b53/b53_ptp.h | 9 +++++ net/dsa/tag_brcm.c | 51 +++++++++++++++++++++++++++ 4 files changed, 120 insertions(+)