linux-stable/net/dsa/tag_ocelot.c
Vladimir Oltean e2f9a8fe73 net: mscc: ocelot: always pass skb clone to ocelot_port_add_txtstamp_skb
Currently, ocelot switchdev passes the skb directly to the function that
enqueues it to the list of skb's awaiting a TX timestamp. Whereas the
felix DSA driver first clones the skb, then passes the clone to this
queue.

This matters because in the case of felix, the common IRQ handler, which
is ocelot_get_txtstamp(), currently clones the clone, and frees the
original clone. This is useless and can be simplified by using
skb_complete_tx_timestamp() instead of skb_tstamp_tx().

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24 19:47:56 -07:00

240 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* Copyright 2019 NXP Semiconductors
*/
#include <soc/mscc/ocelot.h>
#include <linux/packing.h>
#include "dsa_priv.h"
/* The CPU injection header and the CPU extraction header can have 3 types of
* prefixes: long, short and no prefix. The format of the header itself is the
* same in all 3 cases.
*
* Extraction with long prefix:
*
* +-------------------+-------------------+------+------+------------+-------+
* | ff:ff:ff:ff:ff:ff | ff:ff:ff:ff:ff:ff | 8880 | 000a | extraction | frame |
* | | | | | header | |
* +-------------------+-------------------+------+------+------------+-------+
* 48 bits 48 bits 16 bits 16 bits 128 bits
*
* Extraction with short prefix:
*
* +------+------+------------+-------+
* | 8880 | 000a | extraction | frame |
* | | | header | |
* +------+------+------------+-------+
* 16 bits 16 bits 128 bits
*
* Extraction with no prefix:
*
* +------------+-------+
* | extraction | frame |
* | header | |
* +------------+-------+
* 128 bits
*
*
* Injection with long prefix:
*
* +-------------------+-------------------+------+------+------------+-------+
* | any dmac | any smac | 8880 | 000a | injection | frame |
* | | | | | header | |
* +-------------------+-------------------+------+------+------------+-------+
* 48 bits 48 bits 16 bits 16 bits 128 bits
*
* Injection with short prefix:
*
* +------+------+------------+-------+
* | 8880 | 000a | injection | frame |
* | | | header | |
* +------+------+------------+-------+
* 16 bits 16 bits 128 bits
*
* Injection with no prefix:
*
* +------------+-------+
* | injection | frame |
* | header | |
* +------------+-------+
* 128 bits
*
* The injection header looks like this (network byte order, bit 127
* is part of lowest address byte in memory, bit 0 is part of highest
* address byte):
*
* +------+------+------+------+------+------+------+------+
* 127:120 |BYPASS| MASQ | MASQ_PORT |REW_OP|REW_OP|
* +------+------+------+------+------+------+------+------+
* 119:112 | REW_OP |
* +------+------+------+------+------+------+------+------+
* 111:104 | REW_VAL |
* +------+------+------+------+------+------+------+------+
* 103: 96 | REW_VAL |
* +------+------+------+------+------+------+------+------+
* 95: 88 | REW_VAL |
* +------+------+------+------+------+------+------+------+
* 87: 80 | REW_VAL |
* +------+------+------+------+------+------+------+------+
* 79: 72 | RSV |
* +------+------+------+------+------+------+------+------+
* 71: 64 | RSV | DEST |
* +------+------+------+------+------+------+------+------+
* 63: 56 | DEST |
* +------+------+------+------+------+------+------+------+
* 55: 48 | RSV |
* +------+------+------+------+------+------+------+------+
* 47: 40 | RSV | SRC_PORT | RSV |TFRM_TIMER|
* +------+------+------+------+------+------+------+------+
* 39: 32 | TFRM_TIMER | RSV |
* +------+------+------+------+------+------+------+------+
* 31: 24 | RSV | DP | POP_CNT | CPUQ |
* +------+------+------+------+------+------+------+------+
* 23: 16 | CPUQ | QOS_CLASS |TAG_TYPE|
* +------+------+------+------+------+------+------+------+
* 15: 8 | PCP | DEI | VID |
* +------+------+------+------+------+------+------+------+
* 7: 0 | VID |
* +------+------+------+------+------+------+------+------+
*
* And the extraction header looks like this:
*
* +------+------+------+------+------+------+------+------+
* 127:120 | RSV | REW_OP |
* +------+------+------+------+------+------+------+------+
* 119:112 | REW_OP | REW_VAL |
* +------+------+------+------+------+------+------+------+
* 111:104 | REW_VAL |
* +------+------+------+------+------+------+------+------+
* 103: 96 | REW_VAL |
* +------+------+------+------+------+------+------+------+
* 95: 88 | REW_VAL |
* +------+------+------+------+------+------+------+------+
* 87: 80 | REW_VAL | LLEN |
* +------+------+------+------+------+------+------+------+
* 79: 72 | LLEN | WLEN |
* +------+------+------+------+------+------+------+------+
* 71: 64 | WLEN | RSV |
* +------+------+------+------+------+------+------+------+
* 63: 56 | RSV |
* +------+------+------+------+------+------+------+------+
* 55: 48 | RSV |
* +------+------+------+------+------+------+------+------+
* 47: 40 | RSV | SRC_PORT | ACL_ID |
* +------+------+------+------+------+------+------+------+
* 39: 32 | ACL_ID | RSV | SFLOW_ID |
* +------+------+------+------+------+------+------+------+
* 31: 24 |ACL_HIT| DP | LRN_FLAGS | CPUQ |
* +------+------+------+------+------+------+------+------+
* 23: 16 | CPUQ | QOS_CLASS |TAG_TYPE|
* +------+------+------+------+------+------+------+------+
* 15: 8 | PCP | DEI | VID |
* +------+------+------+------+------+------+------+------+
* 7: 0 | VID |
* +------+------+------+------+------+------+------+------+
*/
static struct sk_buff *ocelot_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
struct dsa_port *dp = dsa_slave_to_port(netdev);
struct sk_buff *clone = DSA_SKB_CB(skb)->clone;
struct dsa_switch *ds = dp->ds;
struct ocelot *ocelot = ds->priv;
struct ocelot_port *ocelot_port;
u64 qos_class, rew_op;
u8 *injection;
if (unlikely(skb_cow_head(skb, OCELOT_TAG_LEN) < 0)) {
netdev_err(netdev, "Cannot make room for tag.\n");
return NULL;
}
ocelot_port = ocelot->ports[dp->index];
injection = skb_push(skb, OCELOT_TAG_LEN);
memcpy(injection, ocelot_port->xmit_template, OCELOT_TAG_LEN);
/* Fix up the fields which are not statically determined
* in the template
*/
qos_class = skb->priority;
packing(injection, &qos_class, 19, 17, OCELOT_TAG_LEN, PACK, 0);
/* TX timestamping was requested */
if (clone) {
rew_op = ocelot_port->ptp_cmd;
/* Retrieve timestamp ID populated inside skb->cb[0] of the
* clone by ocelot_port_add_txtstamp_skb
*/
if (ocelot_port->ptp_cmd == IFH_REW_OP_TWO_STEP_PTP)
rew_op |= clone->cb[0] << 3;
packing(injection, &rew_op, 125, 117, OCELOT_TAG_LEN, PACK, 0);
}
return skb;
}
static struct sk_buff *ocelot_rcv(struct sk_buff *skb,
struct net_device *netdev,
struct packet_type *pt)
{
u64 src_port, qos_class;
u8 *start = skb->data;
u8 *extraction;
/* Revert skb->data by the amount consumed by the DSA master,
* so it points to the beginning of the frame.
*/
skb_push(skb, ETH_HLEN);
/* We don't care about the long prefix, it is just for easy entrance
* into the DSA master's RX filter. Discard it now by moving it into
* the headroom.
*/
skb_pull(skb, OCELOT_LONG_PREFIX_LEN);
/* And skb->data now points to the extraction frame header.
* Keep a pointer to it.
*/
extraction = skb->data;
/* Now the EFH is part of the headroom as well */
skb_pull(skb, OCELOT_TAG_LEN);
/* Reset the pointer to the real MAC header */
skb_reset_mac_header(skb);
skb_reset_mac_len(skb);
/* And move skb->data to the correct location again */
skb_pull(skb, ETH_HLEN);
/* Remove from inet csum the extraction header */
skb_postpull_rcsum(skb, start, OCELOT_LONG_PREFIX_LEN + OCELOT_TAG_LEN);
packing(extraction, &src_port, 46, 43, OCELOT_TAG_LEN, UNPACK, 0);
packing(extraction, &qos_class, 19, 17, OCELOT_TAG_LEN, UNPACK, 0);
skb->dev = dsa_master_find_slave(netdev, 0, src_port);
if (!skb->dev)
/* The switch will reflect back some frames sent through
* sockets opened on the bare DSA master. These will come back
* with src_port equal to the index of the CPU port, for which
* there is no slave registered. So don't print any error
* message here (ignore and drop those frames).
*/
return NULL;
skb->offload_fwd_mark = 1;
skb->priority = qos_class;
return skb;
}
static const struct dsa_device_ops ocelot_netdev_ops = {
.name = "ocelot",
.proto = DSA_TAG_PROTO_OCELOT,
.xmit = ocelot_xmit,
.rcv = ocelot_rcv,
.overhead = OCELOT_TAG_LEN + OCELOT_LONG_PREFIX_LEN,
};
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_DSA_TAG_DRIVER(DSA_TAG_PROTO_OCELOT);
module_dsa_tag_driver(ocelot_netdev_ops);