linux/net/ethtool/linkmodes.c
Sean Anderson 0c3e10cb44 net: phy: Add support for rate matching
This adds support for rate matching (also known as rate adaptation) to
the phy subsystem. The general idea is that the phy interface runs at
one speed, and the MAC throttles the rate at which it sends packets to
the link speed. There's a good overview of several techniques for
achieving this at [1]. This patch adds support for three: pause-frame
based (such as in Aquantia phys), CRS-based (such as in 10PASS-TS and
2BASE-TL), and open-loop-based (such as in 10GBASE-W).

This patch makes a few assumptions and a few non assumptions about the
types of rate matching available. First, it assumes that different phys
may use different forms of rate matching. Second, it assumes that phys
can use rate matching for any of their supported link speeds (e.g. if a
phy supports 10BASE-T and XGMII, then it can adapt XGMII to 10BASE-T).
Third, it does not assume that all interface modes will use the same
form of rate matching. Fourth, it does not assume that all phy devices
will support rate matching (even if some do). Relaxing or strengthening
these (non-)assumptions could result in a different API. For example, if
all interface modes were assumed to use the same form of rate matching,
then a bitmask of interface modes supportting rate matching would
suffice.

For some better visibility into the process, the current rate matching
mode is exposed as part of the ethtool ksettings. For the moment, only
read access is supported. I'm not sure what userspace might want to
configure yet (disable it altogether, disable just one mode, specify the
mode to use, etc.). For the moment, since only pause-based rate
adaptation support is added in the next few commits, rate matching can
be disabled altogether by adjusting the advertisement.

802.3 calls this feature "rate adaptation" in clause 49 (10GBASE-R) and
"rate matching" in clause 61 (10PASS-TL and 2BASE-TS). Aquantia also calls
this feature "rate adaptation". I chose "rate matching" because it is
shorter, and because Russell doesn't think "adaptation" is correct in this
context.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2022-09-23 11:55:35 +01:00

369 lines
11 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
#include "netlink.h"
#include "common.h"
#include "bitset.h"
/* LINKMODES_GET */
struct linkmodes_req_info {
struct ethnl_req_info base;
};
struct linkmodes_reply_data {
struct ethnl_reply_data base;
struct ethtool_link_ksettings ksettings;
struct ethtool_link_settings *lsettings;
bool peer_empty;
};
#define LINKMODES_REPDATA(__reply_base) \
container_of(__reply_base, struct linkmodes_reply_data, base)
const struct nla_policy ethnl_linkmodes_get_policy[] = {
[ETHTOOL_A_LINKMODES_HEADER] =
NLA_POLICY_NESTED(ethnl_header_policy),
};
static int linkmodes_prepare_data(const struct ethnl_req_info *req_base,
struct ethnl_reply_data *reply_base,
struct genl_info *info)
{
struct linkmodes_reply_data *data = LINKMODES_REPDATA(reply_base);
struct net_device *dev = reply_base->dev;
int ret;
data->lsettings = &data->ksettings.base;
ret = ethnl_ops_begin(dev);
if (ret < 0)
return ret;
ret = __ethtool_get_link_ksettings(dev, &data->ksettings);
if (ret < 0 && info) {
GENL_SET_ERR_MSG(info, "failed to retrieve link settings");
goto out;
}
if (!dev->ethtool_ops->cap_link_lanes_supported)
data->ksettings.lanes = 0;
data->peer_empty =
bitmap_empty(data->ksettings.link_modes.lp_advertising,
__ETHTOOL_LINK_MODE_MASK_NBITS);
out:
ethnl_ops_complete(dev);
return ret;
}
static int linkmodes_reply_size(const struct ethnl_req_info *req_base,
const struct ethnl_reply_data *reply_base)
{
const struct linkmodes_reply_data *data = LINKMODES_REPDATA(reply_base);
const struct ethtool_link_ksettings *ksettings = &data->ksettings;
const struct ethtool_link_settings *lsettings = &ksettings->base;
bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
int len, ret;
len = nla_total_size(sizeof(u8)) /* LINKMODES_AUTONEG */
+ nla_total_size(sizeof(u32)) /* LINKMODES_SPEED */
+ nla_total_size(sizeof(u32)) /* LINKMODES_LANES */
+ nla_total_size(sizeof(u8)) /* LINKMODES_DUPLEX */
+ nla_total_size(sizeof(u8)) /* LINKMODES_RATE_MATCHING */
+ 0;
ret = ethnl_bitset_size(ksettings->link_modes.advertising,
ksettings->link_modes.supported,
__ETHTOOL_LINK_MODE_MASK_NBITS,
link_mode_names, compact);
if (ret < 0)
return ret;
len += ret;
if (!data->peer_empty) {
ret = ethnl_bitset_size(ksettings->link_modes.lp_advertising,
NULL, __ETHTOOL_LINK_MODE_MASK_NBITS,
link_mode_names, compact);
if (ret < 0)
return ret;
len += ret;
}
if (lsettings->master_slave_cfg != MASTER_SLAVE_CFG_UNSUPPORTED)
len += nla_total_size(sizeof(u8));
if (lsettings->master_slave_state != MASTER_SLAVE_STATE_UNSUPPORTED)
len += nla_total_size(sizeof(u8));
return len;
}
static int linkmodes_fill_reply(struct sk_buff *skb,
const struct ethnl_req_info *req_base,
const struct ethnl_reply_data *reply_base)
{
const struct linkmodes_reply_data *data = LINKMODES_REPDATA(reply_base);
const struct ethtool_link_ksettings *ksettings = &data->ksettings;
const struct ethtool_link_settings *lsettings = &ksettings->base;
bool compact = req_base->flags & ETHTOOL_FLAG_COMPACT_BITSETS;
int ret;
if (nla_put_u8(skb, ETHTOOL_A_LINKMODES_AUTONEG, lsettings->autoneg))
return -EMSGSIZE;
ret = ethnl_put_bitset(skb, ETHTOOL_A_LINKMODES_OURS,
ksettings->link_modes.advertising,
ksettings->link_modes.supported,
__ETHTOOL_LINK_MODE_MASK_NBITS, link_mode_names,
compact);
if (ret < 0)
return -EMSGSIZE;
if (!data->peer_empty) {
ret = ethnl_put_bitset(skb, ETHTOOL_A_LINKMODES_PEER,
ksettings->link_modes.lp_advertising,
NULL, __ETHTOOL_LINK_MODE_MASK_NBITS,
link_mode_names, compact);
if (ret < 0)
return -EMSGSIZE;
}
if (nla_put_u32(skb, ETHTOOL_A_LINKMODES_SPEED, lsettings->speed) ||
nla_put_u8(skb, ETHTOOL_A_LINKMODES_DUPLEX, lsettings->duplex))
return -EMSGSIZE;
if (ksettings->lanes &&
nla_put_u32(skb, ETHTOOL_A_LINKMODES_LANES, ksettings->lanes))
return -EMSGSIZE;
if (lsettings->master_slave_cfg != MASTER_SLAVE_CFG_UNSUPPORTED &&
nla_put_u8(skb, ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG,
lsettings->master_slave_cfg))
return -EMSGSIZE;
if (lsettings->master_slave_state != MASTER_SLAVE_STATE_UNSUPPORTED &&
nla_put_u8(skb, ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE,
lsettings->master_slave_state))
return -EMSGSIZE;
if (nla_put_u8(skb, ETHTOOL_A_LINKMODES_RATE_MATCHING,
lsettings->rate_matching))
return -EMSGSIZE;
return 0;
}
const struct ethnl_request_ops ethnl_linkmodes_request_ops = {
.request_cmd = ETHTOOL_MSG_LINKMODES_GET,
.reply_cmd = ETHTOOL_MSG_LINKMODES_GET_REPLY,
.hdr_attr = ETHTOOL_A_LINKMODES_HEADER,
.req_info_size = sizeof(struct linkmodes_req_info),
.reply_data_size = sizeof(struct linkmodes_reply_data),
.prepare_data = linkmodes_prepare_data,
.reply_size = linkmodes_reply_size,
.fill_reply = linkmodes_fill_reply,
};
/* LINKMODES_SET */
const struct nla_policy ethnl_linkmodes_set_policy[] = {
[ETHTOOL_A_LINKMODES_HEADER] =
NLA_POLICY_NESTED(ethnl_header_policy),
[ETHTOOL_A_LINKMODES_AUTONEG] = { .type = NLA_U8 },
[ETHTOOL_A_LINKMODES_OURS] = { .type = NLA_NESTED },
[ETHTOOL_A_LINKMODES_SPEED] = { .type = NLA_U32 },
[ETHTOOL_A_LINKMODES_DUPLEX] = { .type = NLA_U8 },
[ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG] = { .type = NLA_U8 },
[ETHTOOL_A_LINKMODES_LANES] = NLA_POLICY_RANGE(NLA_U32, 1, 8),
};
/* Set advertised link modes to all supported modes matching requested speed,
* lanes and duplex values. Called when autonegotiation is on, speed, lanes or
* duplex is requested but no link mode change. This is done in userspace with
* ioctl() interface, move it into kernel for netlink.
* Returns true if advertised modes bitmap was modified.
*/
static bool ethnl_auto_linkmodes(struct ethtool_link_ksettings *ksettings,
bool req_speed, bool req_lanes, bool req_duplex)
{
unsigned long *advertising = ksettings->link_modes.advertising;
unsigned long *supported = ksettings->link_modes.supported;
DECLARE_BITMAP(old_adv, __ETHTOOL_LINK_MODE_MASK_NBITS);
unsigned int i;
bitmap_copy(old_adv, advertising, __ETHTOOL_LINK_MODE_MASK_NBITS);
for (i = 0; i < __ETHTOOL_LINK_MODE_MASK_NBITS; i++) {
const struct link_mode_info *info = &link_mode_params[i];
if (info->speed == SPEED_UNKNOWN)
continue;
if (test_bit(i, supported) &&
(!req_speed || info->speed == ksettings->base.speed) &&
(!req_lanes || info->lanes == ksettings->lanes) &&
(!req_duplex || info->duplex == ksettings->base.duplex))
set_bit(i, advertising);
else
clear_bit(i, advertising);
}
return !bitmap_equal(old_adv, advertising,
__ETHTOOL_LINK_MODE_MASK_NBITS);
}
static bool ethnl_validate_master_slave_cfg(u8 cfg)
{
switch (cfg) {
case MASTER_SLAVE_CFG_MASTER_PREFERRED:
case MASTER_SLAVE_CFG_SLAVE_PREFERRED:
case MASTER_SLAVE_CFG_MASTER_FORCE:
case MASTER_SLAVE_CFG_SLAVE_FORCE:
return true;
}
return false;
}
static int ethnl_check_linkmodes(struct genl_info *info, struct nlattr **tb)
{
const struct nlattr *master_slave_cfg, *lanes_cfg;
master_slave_cfg = tb[ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG];
if (master_slave_cfg &&
!ethnl_validate_master_slave_cfg(nla_get_u8(master_slave_cfg))) {
NL_SET_ERR_MSG_ATTR(info->extack, master_slave_cfg,
"master/slave value is invalid");
return -EOPNOTSUPP;
}
lanes_cfg = tb[ETHTOOL_A_LINKMODES_LANES];
if (lanes_cfg && !is_power_of_2(nla_get_u32(lanes_cfg))) {
NL_SET_ERR_MSG_ATTR(info->extack, lanes_cfg,
"lanes value is invalid");
return -EINVAL;
}
return 0;
}
static int ethnl_update_linkmodes(struct genl_info *info, struct nlattr **tb,
struct ethtool_link_ksettings *ksettings,
bool *mod, const struct net_device *dev)
{
struct ethtool_link_settings *lsettings = &ksettings->base;
bool req_speed, req_lanes, req_duplex;
const struct nlattr *master_slave_cfg, *lanes_cfg;
int ret;
master_slave_cfg = tb[ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG];
if (master_slave_cfg) {
if (lsettings->master_slave_cfg == MASTER_SLAVE_CFG_UNSUPPORTED) {
NL_SET_ERR_MSG_ATTR(info->extack, master_slave_cfg,
"master/slave configuration not supported by device");
return -EOPNOTSUPP;
}
}
*mod = false;
req_speed = tb[ETHTOOL_A_LINKMODES_SPEED];
req_lanes = tb[ETHTOOL_A_LINKMODES_LANES];
req_duplex = tb[ETHTOOL_A_LINKMODES_DUPLEX];
ethnl_update_u8(&lsettings->autoneg, tb[ETHTOOL_A_LINKMODES_AUTONEG],
mod);
lanes_cfg = tb[ETHTOOL_A_LINKMODES_LANES];
if (lanes_cfg) {
/* If autoneg is off and lanes parameter is not supported by the
* driver, return an error.
*/
if (!lsettings->autoneg &&
!dev->ethtool_ops->cap_link_lanes_supported) {
NL_SET_ERR_MSG_ATTR(info->extack, lanes_cfg,
"lanes configuration not supported by device");
return -EOPNOTSUPP;
}
} else if (!lsettings->autoneg) {
/* If autoneg is off and lanes parameter is not passed from user,
* set the lanes parameter to 0.
*/
ksettings->lanes = 0;
}
ret = ethnl_update_bitset(ksettings->link_modes.advertising,
__ETHTOOL_LINK_MODE_MASK_NBITS,
tb[ETHTOOL_A_LINKMODES_OURS], link_mode_names,
info->extack, mod);
if (ret < 0)
return ret;
ethnl_update_u32(&lsettings->speed, tb[ETHTOOL_A_LINKMODES_SPEED],
mod);
ethnl_update_u32(&ksettings->lanes, lanes_cfg, mod);
ethnl_update_u8(&lsettings->duplex, tb[ETHTOOL_A_LINKMODES_DUPLEX],
mod);
ethnl_update_u8(&lsettings->master_slave_cfg, master_slave_cfg, mod);
if (!tb[ETHTOOL_A_LINKMODES_OURS] && lsettings->autoneg &&
(req_speed || req_lanes || req_duplex) &&
ethnl_auto_linkmodes(ksettings, req_speed, req_lanes, req_duplex))
*mod = true;
return 0;
}
int ethnl_set_linkmodes(struct sk_buff *skb, struct genl_info *info)
{
struct ethtool_link_ksettings ksettings = {};
struct ethnl_req_info req_info = {};
struct nlattr **tb = info->attrs;
struct net_device *dev;
bool mod = false;
int ret;
ret = ethnl_check_linkmodes(info, tb);
if (ret < 0)
return ret;
ret = ethnl_parse_header_dev_get(&req_info,
tb[ETHTOOL_A_LINKMODES_HEADER],
genl_info_net(info), info->extack,
true);
if (ret < 0)
return ret;
dev = req_info.dev;
ret = -EOPNOTSUPP;
if (!dev->ethtool_ops->get_link_ksettings ||
!dev->ethtool_ops->set_link_ksettings)
goto out_dev;
rtnl_lock();
ret = ethnl_ops_begin(dev);
if (ret < 0)
goto out_rtnl;
ret = __ethtool_get_link_ksettings(dev, &ksettings);
if (ret < 0) {
GENL_SET_ERR_MSG(info, "failed to retrieve link settings");
goto out_ops;
}
ret = ethnl_update_linkmodes(info, tb, &ksettings, &mod, dev);
if (ret < 0)
goto out_ops;
if (mod) {
ret = dev->ethtool_ops->set_link_ksettings(dev, &ksettings);
if (ret < 0)
GENL_SET_ERR_MSG(info, "link settings update failed");
else
ethtool_notify(dev, ETHTOOL_MSG_LINKMODES_NTF, NULL);
}
out_ops:
ethnl_ops_complete(dev);
out_rtnl:
rtnl_unlock();
out_dev:
ethnl_parse_header_dev_put(&req_info);
return ret;
}