[PATCH v4 net-next 09/17] net: dsa: sja1105: Add logic for TX timestamping
From: Vladimir Oltean
Date: Sat Jun 08 2019 - 08:10:11 EST
On TX, timestamping is performed synchronously from the
port_deferred_xmit worker thread.
In management routes, the switch is requested to take egress timestamps
(again partial), which are reconstructed and appended to a clone of the
skb that was just sent. The cloning is done by DSA and we retrieve the
pointer from the structure that DSA keeps in skb->cb.
Then these clones are enqueued to the socket's error queue for
application-level processing.
Signed-off-by: Vladimir Oltean <olteanv@xxxxxxxxx>
---
Changes in v4:
Added a bunch of EXPORT_SYMBOL_GPL.
Changes in v3:
Split from previous 09/10 patch (no functional changes).
Changes in v2:
None.
drivers/net/dsa/sja1105/sja1105.h | 10 +++
drivers/net/dsa/sja1105/sja1105_main.c | 55 ++++++++++++-
drivers/net/dsa/sja1105/sja1105_ptp.c | 106 +++++++++++++++++++++++++
drivers/net/dsa/sja1105/sja1105_ptp.h | 17 ++++
drivers/net/dsa/sja1105/sja1105_spi.c | 14 ++++
include/linux/dsa/sja1105.h | 1 +
6 files changed, 201 insertions(+), 2 deletions(-)
diff --git a/drivers/net/dsa/sja1105/sja1105.h b/drivers/net/dsa/sja1105/sja1105.h
index 3c6296203c21..5a4f83a3417b 100644
--- a/drivers/net/dsa/sja1105/sja1105.h
+++ b/drivers/net/dsa/sja1105/sja1105.h
@@ -33,6 +33,7 @@ struct sja1105_regs {
u64 ptpclk;
u64 ptpclkrate;
u64 ptptsclk;
+ u64 ptpegr_ts[SJA1105_NUM_PORTS];
u64 pad_mii_tx[SJA1105_NUM_PORTS];
u64 cgu_idiv[SJA1105_NUM_PORTS];
u64 rgmii_pad_mii_tx[SJA1105_NUM_PORTS];
@@ -56,6 +57,15 @@ struct sja1105_info {
* switch core and device_id)
*/
u64 part_no;
+ /* E/T and P/Q/R/S have partial timestamps of different sizes.
+ * They must be reconstructed on both families anyway to get the full
+ * 64-bit values back.
+ */
+ int ptp_ts_bits;
+ /* Also SPI commands are of different sizes to retrieve
+ * the egress timestamps.
+ */
+ int ptpegr_ts_bytes;
const struct sja1105_dynamic_table_ops *dyn_ops;
const struct sja1105_table_ops *static_ops;
const struct sja1105_regs *regs;
diff --git a/drivers/net/dsa/sja1105/sja1105_main.c b/drivers/net/dsa/sja1105/sja1105_main.c
index f897fdb12930..121ceccd8107 100644
--- a/drivers/net/dsa/sja1105/sja1105_main.c
+++ b/drivers/net/dsa/sja1105/sja1105_main.c
@@ -1565,7 +1565,7 @@ static int sja1105_setup(struct dsa_switch *ds)
}
static int sja1105_mgmt_xmit(struct dsa_switch *ds, int port, int slot,
- struct sk_buff *skb)
+ struct sk_buff *skb, bool takets)
{
struct sja1105_mgmt_entry mgmt_route = {0};
struct sja1105_private *priv = ds->priv;
@@ -1578,6 +1578,8 @@ static int sja1105_mgmt_xmit(struct dsa_switch *ds, int port, int slot,
mgmt_route.macaddr = ether_addr_to_u64(hdr->h_dest);
mgmt_route.destports = BIT(port);
mgmt_route.enfport = 1;
+ mgmt_route.tsreg = 0;
+ mgmt_route.takets = takets;
rc = sja1105_dynamic_config_write(priv, BLK_IDX_MGMT_ROUTE,
slot, &mgmt_route, true);
@@ -1629,7 +1631,11 @@ static netdev_tx_t sja1105_port_deferred_xmit(struct dsa_switch *ds, int port,
{
struct sja1105_private *priv = ds->priv;
struct sja1105_port *sp = &priv->ports[port];
+ struct skb_shared_hwtstamps shwt = {0};
int slot = sp->mgmt_slot;
+ struct sk_buff *clone;
+ u64 now, ts;
+ int rc;
/* The tragic fact about the switch having 4x2 slots for installing
* management routes is that all of them except one are actually
@@ -1647,8 +1653,36 @@ static netdev_tx_t sja1105_port_deferred_xmit(struct dsa_switch *ds, int port,
*/
mutex_lock(&priv->mgmt_lock);
- sja1105_mgmt_xmit(ds, port, slot, skb);
+ /* The clone, if there, was made by dsa_skb_tx_timestamp */
+ clone = DSA_SKB_CB(skb)->clone;
+
+ sja1105_mgmt_xmit(ds, port, slot, skb, !!clone);
+
+ if (!clone)
+ goto out;
+
+ skb_shinfo(clone)->tx_flags |= SKBTX_IN_PROGRESS;
+
+ mutex_lock(&priv->ptp_lock);
+
+ now = priv->tstamp_cc.read(&priv->tstamp_cc);
+
+ rc = sja1105_ptpegr_ts_poll(priv, slot, &ts);
+ if (rc < 0) {
+ dev_err(ds->dev, "xmit: timed out polling for tstamp\n");
+ kfree_skb(clone);
+ goto out_unlock_ptp;
+ }
+
+ ts = sja1105_tstamp_reconstruct(priv, now, ts);
+ ts = timecounter_cyc2time(&priv->tstamp_tc, ts);
+ shwt.hwtstamp = ns_to_ktime(ts);
+ skb_complete_tx_timestamp(clone, &shwt);
+
+out_unlock_ptp:
+ mutex_unlock(&priv->ptp_lock);
+out:
mutex_unlock(&priv->mgmt_lock);
return NETDEV_TX_OK;
}
@@ -1677,6 +1711,22 @@ static int sja1105_set_ageing_time(struct dsa_switch *ds,
return sja1105_static_config_reload(priv);
}
+/* Called from dsa_skb_tx_timestamp. This callback is just to make DSA clone
+ * the skb and have it available in DSA_SKB_CB in the .port_deferred_xmit
+ * callback, where we will timestamp it synchronously.
+ */
+bool sja1105_port_txtstamp(struct dsa_switch *ds, int port,
+ struct sk_buff *skb, unsigned int type)
+{
+ struct sja1105_private *priv = ds->priv;
+ struct sja1105_port *sp = &priv->ports[port];
+
+ if (!sp->hwts_tx_en)
+ return false;
+
+ return true;
+}
+
static const struct dsa_switch_ops sja1105_switch_ops = {
.get_tag_protocol = sja1105_get_tag_protocol,
.setup = sja1105_setup,
@@ -1701,6 +1751,7 @@ static const struct dsa_switch_ops sja1105_switch_ops = {
.port_mdb_add = sja1105_mdb_add,
.port_mdb_del = sja1105_mdb_del,
.port_deferred_xmit = sja1105_port_deferred_xmit,
+ .port_txtstamp = sja1105_port_txtstamp,
};
static int sja1105_check_device_id(struct sja1105_private *priv)
diff --git a/drivers/net/dsa/sja1105/sja1105_ptp.c b/drivers/net/dsa/sja1105/sja1105_ptp.c
index 47313a6ec932..01ecc8fb1b30 100644
--- a/drivers/net/dsa/sja1105/sja1105_ptp.c
+++ b/drivers/net/dsa/sja1105/sja1105_ptp.c
@@ -113,6 +113,112 @@ int sja1105pqrs_ptp_cmd(const void *ctx, const void *data)
}
EXPORT_SYMBOL_GPL(sja1105pqrs_ptp_cmd);
+/* The switch returns partial timestamps (24 bits for SJA1105 E/T, which wrap
+ * around in 0.135 seconds, and 32 bits for P/Q/R/S, wrapping around in 34.35
+ * seconds).
+ *
+ * This receives the RX or TX MAC timestamps, provided by hardware as
+ * the lower bits of the cycle counter, sampled at the time the timestamp was
+ * collected.
+ *
+ * To reconstruct into a full 64-bit-wide timestamp, the cycle counter is
+ * read and the high-order bits are filled in.
+ *
+ * Must be called within one wraparound period of the partial timestamp since
+ * it was generated by the MAC.
+ */
+u64 sja1105_tstamp_reconstruct(struct sja1105_private *priv, u64 now,
+ u64 ts_partial)
+{
+ u64 partial_tstamp_mask = CYCLECOUNTER_MASK(priv->info->ptp_ts_bits);
+ u64 ts_reconstructed;
+
+ ts_reconstructed = (now & ~partial_tstamp_mask) | ts_partial;
+
+ /* Check lower bits of current cycle counter against the timestamp.
+ * If the current cycle counter is lower than the partial timestamp,
+ * then wraparound surely occurred and must be accounted for.
+ */
+ if ((now & partial_tstamp_mask) <= ts_partial)
+ ts_reconstructed -= (partial_tstamp_mask + 1);
+
+ return ts_reconstructed;
+}
+EXPORT_SYMBOL_GPL(sja1105_tstamp_reconstruct);
+
+/* Reads the SPI interface for an egress timestamp generated by the switch
+ * for frames sent using management routes.
+ *
+ * SJA1105 E/T layout of the 4-byte SPI payload:
+ *
+ * 31 23 15 7 0
+ * | | | | |
+ * +-----+-----+-----+ ^
+ * ^ |
+ * | |
+ * 24-bit timestamp Update bit
+ *
+ *
+ * SJA1105 P/Q/R/S layout of the 8-byte SPI payload:
+ *
+ * 31 23 15 7 0 63 55 47 39 32
+ * | | | | | | | | | |
+ * ^ +-----+-----+-----+-----+
+ * | ^
+ * | |
+ * Update bit 32-bit timestamp
+ *
+ * Notice that the update bit is in the same place.
+ * To have common code for E/T and P/Q/R/S for reading the timestamp,
+ * we need to juggle with the offset and the bit indices.
+ */
+int sja1105_ptpegr_ts_poll(struct sja1105_private *priv, int port, u64 *ts)
+{
+ const struct sja1105_regs *regs = priv->info->regs;
+ int tstamp_bit_start, tstamp_bit_end;
+ int timeout = 10;
+ u8 packed_buf[8];
+ u64 update;
+ int rc;
+
+ do {
+ rc = sja1105_spi_send_packed_buf(priv, SPI_READ,
+ regs->ptpegr_ts[port],
+ packed_buf,
+ priv->info->ptpegr_ts_bytes);
+ if (rc < 0)
+ return rc;
+
+ sja1105_unpack(packed_buf, &update, 0, 0,
+ priv->info->ptpegr_ts_bytes);
+ if (update)
+ break;
+
+ usleep_range(10, 50);
+ } while (--timeout);
+
+ if (!timeout)
+ return -ETIMEDOUT;
+
+ /* Point the end bit to the second 32-bit word on P/Q/R/S,
+ * no-op on E/T.
+ */
+ tstamp_bit_end = (priv->info->ptpegr_ts_bytes - 4) * 8;
+ /* Shift the 24-bit timestamp on E/T to be collected from 31:8.
+ * No-op on P/Q/R/S.
+ */
+ tstamp_bit_end += 32 - priv->info->ptp_ts_bits;
+ tstamp_bit_start = tstamp_bit_end + priv->info->ptp_ts_bits - 1;
+
+ *ts = 0;
+
+ sja1105_unpack(packed_buf, ts, tstamp_bit_start, tstamp_bit_end,
+ priv->info->ptpegr_ts_bytes);
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(sja1105_ptpegr_ts_poll);
+
int sja1105_ptp_reset(struct sja1105_private *priv)
{
struct dsa_switch *ds = priv->ds;
diff --git a/drivers/net/dsa/sja1105/sja1105_ptp.h b/drivers/net/dsa/sja1105/sja1105_ptp.h
index 137ffbb0a233..af456b0a4d27 100644
--- a/drivers/net/dsa/sja1105/sja1105_ptp.h
+++ b/drivers/net/dsa/sja1105/sja1105_ptp.h
@@ -10,6 +10,8 @@ int sja1105_ptp_clock_register(struct sja1105_private *priv);
void sja1105_ptp_clock_unregister(struct sja1105_private *priv);
+int sja1105_ptpegr_ts_poll(struct sja1105_private *priv, int port, u64 *ts);
+
int sja1105et_ptp_cmd(const void *ctx, const void *data);
int sja1105pqrs_ptp_cmd(const void *ctx, const void *data);
@@ -17,6 +19,9 @@ int sja1105pqrs_ptp_cmd(const void *ctx, const void *data);
int sja1105_get_ts_info(struct dsa_switch *ds, int port,
struct ethtool_ts_info *ts);
+u64 sja1105_tstamp_reconstruct(struct sja1105_private *priv, u64 now,
+ u64 ts_partial);
+
int sja1105_ptp_reset(struct sja1105_private *priv);
#else
@@ -31,6 +36,18 @@ static inline void sja1105_ptp_clock_unregister(struct sja1105_private *priv)
return;
}
+static inline int
+sja1105_ptpegr_ts_poll(struct sja1105_private *priv, int port, u64 *ts)
+{
+ return 0;
+}
+
+static inline u64 sja1105_tstamp_reconstruct(struct sja1105_private *priv,
+ u64 now, u64 ts_partial)
+{
+ return 0;
+}
+
static inline int sja1105_ptp_reset(struct sja1105_private *priv)
{
return 0;
diff --git a/drivers/net/dsa/sja1105/sja1105_spi.c b/drivers/net/dsa/sja1105/sja1105_spi.c
index a0d08e6c22ff..d729a0f0b28e 100644
--- a/drivers/net/dsa/sja1105/sja1105_spi.c
+++ b/drivers/net/dsa/sja1105/sja1105_spi.c
@@ -514,6 +514,7 @@ static struct sja1105_regs sja1105et_regs = {
.rgmii_tx_clk = {0x100016, 0x10001D, 0x100024, 0x10002B, 0x100032},
.rmii_ref_clk = {0x100015, 0x10001C, 0x100023, 0x10002A, 0x100031},
.rmii_ext_tx_clk = {0x100018, 0x10001F, 0x100026, 0x10002D, 0x100034},
+ .ptpegr_ts = {0xC0, 0xC2, 0xC4, 0xC6, 0xC8},
.ptp_control = 0x17,
.ptpclk = 0x18, /* Spans 0x18 to 0x19 */
.ptpclkrate = 0x1A,
@@ -544,6 +545,7 @@ static struct sja1105_regs sja1105pqrs_regs = {
.rmii_ref_clk = {0x100015, 0x10001B, 0x100021, 0x100027, 0x10002D},
.rmii_ext_tx_clk = {0x100017, 0x10001D, 0x100023, 0x100029, 0x10002F},
.qlevel = {0x604, 0x614, 0x624, 0x634, 0x644},
+ .ptpegr_ts = {0xC0, 0xC4, 0xC8, 0xCC, 0xD0},
.ptp_control = 0x18,
.ptpclk = 0x19,
.ptpclkrate = 0x1B,
@@ -555,6 +557,8 @@ struct sja1105_info sja1105e_info = {
.part_no = SJA1105ET_PART_NO,
.static_ops = sja1105e_table_ops,
.dyn_ops = sja1105et_dyn_ops,
+ .ptp_ts_bits = 24,
+ .ptpegr_ts_bytes = 4,
.reset_cmd = sja1105et_reset_cmd,
.fdb_add_cmd = sja1105et_fdb_add,
.fdb_del_cmd = sja1105et_fdb_del,
@@ -567,6 +571,8 @@ struct sja1105_info sja1105t_info = {
.part_no = SJA1105ET_PART_NO,
.static_ops = sja1105t_table_ops,
.dyn_ops = sja1105et_dyn_ops,
+ .ptp_ts_bits = 24,
+ .ptpegr_ts_bytes = 4,
.reset_cmd = sja1105et_reset_cmd,
.fdb_add_cmd = sja1105et_fdb_add,
.fdb_del_cmd = sja1105et_fdb_del,
@@ -579,6 +585,8 @@ struct sja1105_info sja1105p_info = {
.part_no = SJA1105P_PART_NO,
.static_ops = sja1105p_table_ops,
.dyn_ops = sja1105pqrs_dyn_ops,
+ .ptp_ts_bits = 32,
+ .ptpegr_ts_bytes = 8,
.reset_cmd = sja1105pqrs_reset_cmd,
.fdb_add_cmd = sja1105pqrs_fdb_add,
.fdb_del_cmd = sja1105pqrs_fdb_del,
@@ -591,6 +599,8 @@ struct sja1105_info sja1105q_info = {
.part_no = SJA1105Q_PART_NO,
.static_ops = sja1105q_table_ops,
.dyn_ops = sja1105pqrs_dyn_ops,
+ .ptp_ts_bits = 32,
+ .ptpegr_ts_bytes = 8,
.reset_cmd = sja1105pqrs_reset_cmd,
.fdb_add_cmd = sja1105pqrs_fdb_add,
.fdb_del_cmd = sja1105pqrs_fdb_del,
@@ -603,6 +613,8 @@ struct sja1105_info sja1105r_info = {
.part_no = SJA1105R_PART_NO,
.static_ops = sja1105r_table_ops,
.dyn_ops = sja1105pqrs_dyn_ops,
+ .ptp_ts_bits = 32,
+ .ptpegr_ts_bytes = 8,
.reset_cmd = sja1105pqrs_reset_cmd,
.fdb_add_cmd = sja1105pqrs_fdb_add,
.fdb_del_cmd = sja1105pqrs_fdb_del,
@@ -616,6 +628,8 @@ struct sja1105_info sja1105s_info = {
.static_ops = sja1105s_table_ops,
.dyn_ops = sja1105pqrs_dyn_ops,
.regs = &sja1105pqrs_regs,
+ .ptp_ts_bits = 32,
+ .ptpegr_ts_bytes = 8,
.reset_cmd = sja1105pqrs_reset_cmd,
.fdb_add_cmd = sja1105pqrs_fdb_add,
.fdb_del_cmd = sja1105pqrs_fdb_del,
diff --git a/include/linux/dsa/sja1105.h b/include/linux/dsa/sja1105.h
index e46e18c47d41..5a956f335022 100644
--- a/include/linux/dsa/sja1105.h
+++ b/include/linux/dsa/sja1105.h
@@ -22,6 +22,7 @@
struct sja1105_port {
struct dsa_port *dp;
+ bool hwts_tx_en;
int mgmt_slot;
};
--
2.17.1