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authorDavid Decotigny <decot@googlers.com>2016-02-24 10:57:59 -0800
committerDavid S. Miller <davem@davemloft.net>2016-02-25 22:06:45 -0500
commit3f1ac7a700d039c61d8d8b99f28d605d489a60cf (patch)
tree29c4c9832e87bce2f685a097b00029f64d93f88c /net/core/ethtool.c
parent48133335d7e0a661f40a5899d20945dabb600f0a (diff)
net: ethtool: add new ETHTOOL_xLINKSETTINGS API
This patch defines a new ETHTOOL_GLINKSETTINGS/SLINKSETTINGS API, handled by the new get_link_ksettings/set_link_ksettings callbacks. This API provides support for most legacy ethtool_cmd fields, adds support for larger link mode masks (up to 4064 bits, variable length), and removes ethtool_cmd deprecated fields (transceiver/maxrxpkt/maxtxpkt). This API is deprecating the legacy ETHTOOL_GSET/SSET API and provides the following backward compatibility properties: - legacy ethtool with legacy drivers: no change, still using the get_settings/set_settings callbacks. - legacy ethtool with new get/set_link_ksettings drivers: the new driver callbacks are used, data internally converted to legacy ethtool_cmd. ETHTOOL_GSET will return only the 1st 32b of each link mode mask. ETHTOOL_SSET will fail if user tries to set the ethtool_cmd deprecated fields to non-0 (transceiver/maxrxpkt/maxtxpkt). A kernel warning is logged if driver sets higher bits. - future ethtool with legacy drivers: no change, still using the get_settings/set_settings callbacks, internally converted to new data structure. Deprecated fields (transceiver/maxrxpkt/maxtxpkt) will be ignored and seen as 0 from user space. Note that that "future" ethtool tool will not allow changes to these deprecated fields. - future ethtool with new drivers: direct call to the new callbacks. By "future" ethtool, what is meant is: - query: first try ETHTOOL_GLINKSETTINGS, and revert to ETHTOOL_GSET if fails - set: query first and remember which of ETHTOOL_GLINKSETTINGS or ETHTOOL_GSET was successful + if ETHTOOL_GLINKSETTINGS was successful, then change config with ETHTOOL_SLINKSETTINGS. A failure there is final (do not try ETHTOOL_SSET). + otherwise ETHTOOL_GSET was successful, change config with ETHTOOL_SSET. A failure there is final (do not try ETHTOOL_SLINKSETTINGS). The interaction user/kernel via the new API requires a small ETHTOOL_GLINKSETTINGS handshake first to agree on the length of the link mode bitmaps. If kernel doesn't agree with user, it returns the bitmap length it is expecting from user as a negative length (and cmd field is 0). When kernel and user agree, kernel returns valid info in all fields (ie. link mode length > 0 and cmd is ETHTOOL_GLINKSETTINGS). Data structure crossing user/kernel boundary is 32/64-bit agnostic. Converted internally to a legal kernel bitmap. The internal __ethtool_get_settings kernel helper will gradually be replaced by __ethtool_get_link_ksettings by the time the first "link_settings" drivers start to appear. So this patch doesn't change it, it will be removed before it needs to be changed. Signed-off-by: David Decotigny <decot@googlers.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/ethtool.c')
-rw-r--r--net/core/ethtool.c453
1 files changed, 447 insertions, 6 deletions
diff --git a/net/core/ethtool.c b/net/core/ethtool.c
index 2406101002b1..edcec56ed228 100644
--- a/net/core/ethtool.c
+++ b/net/core/ethtool.c
@@ -387,6 +387,359 @@ static int __ethtool_set_flags(struct net_device *dev, u32 data)
return 0;
}
+static void convert_legacy_u32_to_link_mode(unsigned long *dst, u32 legacy_u32)
+{
+ bitmap_zero(dst, __ETHTOOL_LINK_MODE_MASK_NBITS);
+ dst[0] = legacy_u32;
+}
+
+/* return false if src had higher bits set. lower bits always updated. */
+static bool convert_link_mode_to_legacy_u32(u32 *legacy_u32,
+ const unsigned long *src)
+{
+ bool retval = true;
+
+ /* TODO: following test will soon always be true */
+ if (__ETHTOOL_LINK_MODE_MASK_NBITS > 32) {
+ __ETHTOOL_DECLARE_LINK_MODE_MASK(ext);
+
+ bitmap_zero(ext, __ETHTOOL_LINK_MODE_MASK_NBITS);
+ bitmap_fill(ext, 32);
+ bitmap_complement(ext, ext, __ETHTOOL_LINK_MODE_MASK_NBITS);
+ if (bitmap_intersects(ext, src,
+ __ETHTOOL_LINK_MODE_MASK_NBITS)) {
+ /* src mask goes beyond bit 31 */
+ retval = false;
+ }
+ }
+ *legacy_u32 = src[0];
+ return retval;
+}
+
+/* return false if legacy contained non-0 deprecated fields
+ * transceiver/maxtxpkt/maxrxpkt. rest of ksettings always updated
+ */
+static bool
+convert_legacy_settings_to_link_ksettings(
+ struct ethtool_link_ksettings *link_ksettings,
+ const struct ethtool_cmd *legacy_settings)
+{
+ bool retval = true;
+
+ memset(link_ksettings, 0, sizeof(*link_ksettings));
+
+ /* This is used to tell users that driver is still using these
+ * deprecated legacy fields, and they should not use
+ * %ETHTOOL_GLINKSETTINGS/%ETHTOOL_SLINKSETTINGS
+ */
+ if (legacy_settings->transceiver ||
+ legacy_settings->maxtxpkt ||
+ legacy_settings->maxrxpkt)
+ retval = false;
+
+ convert_legacy_u32_to_link_mode(
+ link_ksettings->link_modes.supported,
+ legacy_settings->supported);
+ convert_legacy_u32_to_link_mode(
+ link_ksettings->link_modes.advertising,
+ legacy_settings->advertising);
+ convert_legacy_u32_to_link_mode(
+ link_ksettings->link_modes.lp_advertising,
+ legacy_settings->lp_advertising);
+ link_ksettings->base.speed
+ = ethtool_cmd_speed(legacy_settings);
+ link_ksettings->base.duplex
+ = legacy_settings->duplex;
+ link_ksettings->base.port
+ = legacy_settings->port;
+ link_ksettings->base.phy_address
+ = legacy_settings->phy_address;
+ link_ksettings->base.autoneg
+ = legacy_settings->autoneg;
+ link_ksettings->base.mdio_support
+ = legacy_settings->mdio_support;
+ link_ksettings->base.eth_tp_mdix
+ = legacy_settings->eth_tp_mdix;
+ link_ksettings->base.eth_tp_mdix_ctrl
+ = legacy_settings->eth_tp_mdix_ctrl;
+ return retval;
+}
+
+/* return false if ksettings link modes had higher bits
+ * set. legacy_settings always updated (best effort)
+ */
+static bool
+convert_link_ksettings_to_legacy_settings(
+ struct ethtool_cmd *legacy_settings,
+ const struct ethtool_link_ksettings *link_ksettings)
+{
+ bool retval = true;
+
+ memset(legacy_settings, 0, sizeof(*legacy_settings));
+ /* this also clears the deprecated fields in legacy structure:
+ * __u8 transceiver;
+ * __u32 maxtxpkt;
+ * __u32 maxrxpkt;
+ */
+
+ retval &= convert_link_mode_to_legacy_u32(
+ &legacy_settings->supported,
+ link_ksettings->link_modes.supported);
+ retval &= convert_link_mode_to_legacy_u32(
+ &legacy_settings->advertising,
+ link_ksettings->link_modes.advertising);
+ retval &= convert_link_mode_to_legacy_u32(
+ &legacy_settings->lp_advertising,
+ link_ksettings->link_modes.lp_advertising);
+ ethtool_cmd_speed_set(legacy_settings, link_ksettings->base.speed);
+ legacy_settings->duplex
+ = link_ksettings->base.duplex;
+ legacy_settings->port
+ = link_ksettings->base.port;
+ legacy_settings->phy_address
+ = link_ksettings->base.phy_address;
+ legacy_settings->autoneg
+ = link_ksettings->base.autoneg;
+ legacy_settings->mdio_support
+ = link_ksettings->base.mdio_support;
+ legacy_settings->eth_tp_mdix
+ = link_ksettings->base.eth_tp_mdix;
+ legacy_settings->eth_tp_mdix_ctrl
+ = link_ksettings->base.eth_tp_mdix_ctrl;
+ return retval;
+}
+
+/* number of 32-bit words to store the user's link mode bitmaps */
+#define __ETHTOOL_LINK_MODE_MASK_NU32 \
+ DIV_ROUND_UP(__ETHTOOL_LINK_MODE_MASK_NBITS, 32)
+
+/* layout of the struct passed from/to userland */
+struct ethtool_link_usettings {
+ struct ethtool_link_settings base;
+ struct {
+ __u32 supported[__ETHTOOL_LINK_MODE_MASK_NU32];
+ __u32 advertising[__ETHTOOL_LINK_MODE_MASK_NU32];
+ __u32 lp_advertising[__ETHTOOL_LINK_MODE_MASK_NU32];
+ } link_modes;
+};
+
+/* Internal kernel helper to query a device ethtool_link_settings.
+ *
+ * Backward compatibility note: for compatibility with legacy drivers
+ * that implement only the ethtool_cmd API, this has to work with both
+ * drivers implementing get_link_ksettings API and drivers
+ * implementing get_settings API. When drivers implement get_settings
+ * and report ethtool_cmd deprecated fields
+ * (transceiver/maxrxpkt/maxtxpkt), these fields are silently ignored
+ * because the resulting struct ethtool_link_settings does not report them.
+ */
+int __ethtool_get_link_ksettings(struct net_device *dev,
+ struct ethtool_link_ksettings *link_ksettings)
+{
+ int err;
+ struct ethtool_cmd cmd;
+
+ ASSERT_RTNL();
+
+ if (dev->ethtool_ops->get_link_ksettings) {
+ memset(link_ksettings, 0, sizeof(*link_ksettings));
+ return dev->ethtool_ops->get_link_ksettings(dev,
+ link_ksettings);
+ }
+
+ /* driver doesn't support %ethtool_link_ksettings API. revert to
+ * legacy %ethtool_cmd API, unless it's not supported either.
+ * TODO: remove when ethtool_ops::get_settings disappears internally
+ */
+ err = __ethtool_get_settings(dev, &cmd);
+ if (err < 0)
+ return err;
+
+ /* we ignore deprecated fields transceiver/maxrxpkt/maxtxpkt
+ */
+ convert_legacy_settings_to_link_ksettings(link_ksettings, &cmd);
+ return err;
+}
+EXPORT_SYMBOL(__ethtool_get_link_ksettings);
+
+/* convert ethtool_link_usettings in user space to a kernel internal
+ * ethtool_link_ksettings. return 0 on success, errno on error.
+ */
+static int load_link_ksettings_from_user(struct ethtool_link_ksettings *to,
+ const void __user *from)
+{
+ struct ethtool_link_usettings link_usettings;
+
+ if (copy_from_user(&link_usettings, from, sizeof(link_usettings)))
+ return -EFAULT;
+
+ memcpy(&to->base, &link_usettings.base, sizeof(to->base));
+ bitmap_from_u32array(to->link_modes.supported,
+ __ETHTOOL_LINK_MODE_MASK_NBITS,
+ link_usettings.link_modes.supported,
+ __ETHTOOL_LINK_MODE_MASK_NU32);
+ bitmap_from_u32array(to->link_modes.advertising,
+ __ETHTOOL_LINK_MODE_MASK_NBITS,
+ link_usettings.link_modes.advertising,
+ __ETHTOOL_LINK_MODE_MASK_NU32);
+ bitmap_from_u32array(to->link_modes.lp_advertising,
+ __ETHTOOL_LINK_MODE_MASK_NBITS,
+ link_usettings.link_modes.lp_advertising,
+ __ETHTOOL_LINK_MODE_MASK_NU32);
+
+ return 0;
+}
+
+/* convert a kernel internal ethtool_link_ksettings to
+ * ethtool_link_usettings in user space. return 0 on success, errno on
+ * error.
+ */
+static int
+store_link_ksettings_for_user(void __user *to,
+ const struct ethtool_link_ksettings *from)
+{
+ struct ethtool_link_usettings link_usettings;
+
+ memcpy(&link_usettings.base, &from->base, sizeof(link_usettings));
+ bitmap_to_u32array(link_usettings.link_modes.supported,
+ __ETHTOOL_LINK_MODE_MASK_NU32,
+ from->link_modes.supported,
+ __ETHTOOL_LINK_MODE_MASK_NBITS);
+ bitmap_to_u32array(link_usettings.link_modes.advertising,
+ __ETHTOOL_LINK_MODE_MASK_NU32,
+ from->link_modes.advertising,
+ __ETHTOOL_LINK_MODE_MASK_NBITS);
+ bitmap_to_u32array(link_usettings.link_modes.lp_advertising,
+ __ETHTOOL_LINK_MODE_MASK_NU32,
+ from->link_modes.lp_advertising,
+ __ETHTOOL_LINK_MODE_MASK_NBITS);
+
+ if (copy_to_user(to, &link_usettings, sizeof(link_usettings)))
+ return -EFAULT;
+
+ return 0;
+}
+
+/* Query device for its ethtool_link_settings.
+ *
+ * Backward compatibility note: this function must fail when driver
+ * does not implement ethtool::get_link_ksettings, even if legacy
+ * ethtool_ops::get_settings is implemented. This tells new versions
+ * of ethtool that they should use the legacy API %ETHTOOL_GSET for
+ * this driver, so that they can correctly access the ethtool_cmd
+ * deprecated fields (transceiver/maxrxpkt/maxtxpkt), until no driver
+ * implements ethtool_ops::get_settings anymore.
+ */
+static int ethtool_get_link_ksettings(struct net_device *dev,
+ void __user *useraddr)
+{
+ int err = 0;
+ struct ethtool_link_ksettings link_ksettings;
+
+ ASSERT_RTNL();
+
+ if (!dev->ethtool_ops->get_link_ksettings)
+ return -EOPNOTSUPP;
+
+ /* handle bitmap nbits handshake */
+ if (copy_from_user(&link_ksettings.base, useraddr,
+ sizeof(link_ksettings.base)))
+ return -EFAULT;
+
+ if (__ETHTOOL_LINK_MODE_MASK_NU32
+ != link_ksettings.base.link_mode_masks_nwords) {
+ /* wrong link mode nbits requested */
+ memset(&link_ksettings, 0, sizeof(link_ksettings));
+ /* keep cmd field reset to 0 */
+ /* send back number of words required as negative val */
+ compiletime_assert(__ETHTOOL_LINK_MODE_MASK_NU32 <= S8_MAX,
+ "need too many bits for link modes!");
+ link_ksettings.base.link_mode_masks_nwords
+ = -((s8)__ETHTOOL_LINK_MODE_MASK_NU32);
+
+ /* copy the base fields back to user, not the link
+ * mode bitmaps
+ */
+ if (copy_to_user(useraddr, &link_ksettings.base,
+ sizeof(link_ksettings.base)))
+ return -EFAULT;
+
+ return 0;
+ }
+
+ /* handshake successful: user/kernel agree on
+ * link_mode_masks_nwords
+ */
+
+ memset(&link_ksettings, 0, sizeof(link_ksettings));
+ err = dev->ethtool_ops->get_link_ksettings(dev, &link_ksettings);
+ if (err < 0)
+ return err;
+
+ /* make sure we tell the right values to user */
+ link_ksettings.base.cmd = ETHTOOL_GLINKSETTINGS;
+ link_ksettings.base.link_mode_masks_nwords
+ = __ETHTOOL_LINK_MODE_MASK_NU32;
+
+ return store_link_ksettings_for_user(useraddr, &link_ksettings);
+}
+
+/* Update device ethtool_link_settings.
+ *
+ * Backward compatibility note: this function must fail when driver
+ * does not implement ethtool::set_link_ksettings, even if legacy
+ * ethtool_ops::set_settings is implemented. This tells new versions
+ * of ethtool that they should use the legacy API %ETHTOOL_SSET for
+ * this driver, so that they can correctly update the ethtool_cmd
+ * deprecated fields (transceiver/maxrxpkt/maxtxpkt), until no driver
+ * implements ethtool_ops::get_settings anymore.
+ */
+static int ethtool_set_link_ksettings(struct net_device *dev,
+ void __user *useraddr)
+{
+ int err;
+ struct ethtool_link_ksettings link_ksettings;
+
+ ASSERT_RTNL();
+
+ if (!dev->ethtool_ops->set_link_ksettings)
+ return -EOPNOTSUPP;
+
+ /* make sure nbits field has expected value */
+ if (copy_from_user(&link_ksettings.base, useraddr,
+ sizeof(link_ksettings.base)))
+ return -EFAULT;
+
+ if (__ETHTOOL_LINK_MODE_MASK_NU32
+ != link_ksettings.base.link_mode_masks_nwords)
+ return -EINVAL;
+
+ /* copy the whole structure, now that we know it has expected
+ * format
+ */
+ err = load_link_ksettings_from_user(&link_ksettings, useraddr);
+ if (err)
+ return err;
+
+ /* re-check nwords field, just in case */
+ if (__ETHTOOL_LINK_MODE_MASK_NU32
+ != link_ksettings.base.link_mode_masks_nwords)
+ return -EINVAL;
+
+ return dev->ethtool_ops->set_link_ksettings(dev, &link_ksettings);
+}
+
+/* Internal kernel helper to query a device ethtool_cmd settings.
+ *
+ * Note about transition to ethtool_link_settings API: We do not need
+ * (or want) this function to support "dev" instances that implement
+ * the ethtool_link_settings API as we will update the drivers calling
+ * this function to call __ethtool_get_link_ksettings instead, before
+ * the first drivers implement ethtool_ops::get_link_ksettings.
+ *
+ * TODO 1: at least make this function static when no driver is using it
+ * TODO 2: remove when ethtool_ops::get_settings disappears internally
+ */
int __ethtool_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
{
ASSERT_RTNL();
@@ -400,30 +753,112 @@ int __ethtool_get_settings(struct net_device *dev, struct ethtool_cmd *cmd)
}
EXPORT_SYMBOL(__ethtool_get_settings);
+static void
+warn_incomplete_ethtool_legacy_settings_conversion(const char *details)
+{
+ char name[sizeof(current->comm)];
+
+ pr_info_once("warning: `%s' uses legacy ethtool link settings API, %s\n",
+ get_task_comm(name, current), details);
+}
+
+/* Query device for its ethtool_cmd settings.
+ *
+ * Backward compatibility note: for compatibility with legacy ethtool,
+ * this has to work with both drivers implementing get_link_ksettings
+ * API and drivers implementing get_settings API. When drivers
+ * implement get_link_ksettings and report higher link mode bits, a
+ * kernel warning is logged once (with name of 1st driver/device) to
+ * recommend user to upgrade ethtool, but the command is successful
+ * (only the lower link mode bits reported back to user).
+ */
static int ethtool_get_settings(struct net_device *dev, void __user *useraddr)
{
- int err;
struct ethtool_cmd cmd;
- err = __ethtool_get_settings(dev, &cmd);
- if (err < 0)
- return err;
+ ASSERT_RTNL();
+
+ if (dev->ethtool_ops->get_link_ksettings) {
+ /* First, use link_ksettings API if it is supported */
+ int err;
+ struct ethtool_link_ksettings link_ksettings;
+
+ memset(&link_ksettings, 0, sizeof(link_ksettings));
+ err = dev->ethtool_ops->get_link_ksettings(dev,
+ &link_ksettings);
+ if (err < 0)
+ return err;
+ if (!convert_link_ksettings_to_legacy_settings(&cmd,
+ &link_ksettings))
+ warn_incomplete_ethtool_legacy_settings_conversion(
+ "link modes are only partially reported");
+
+ /* send a sensible cmd tag back to user */
+ cmd.cmd = ETHTOOL_GSET;
+ } else {
+ int err;
+ /* TODO: return -EOPNOTSUPP when
+ * ethtool_ops::get_settings disappears internally
+ */
+
+ /* driver doesn't support %ethtool_link_ksettings
+ * API. revert to legacy %ethtool_cmd API, unless it's
+ * not supported either.
+ */
+ err = __ethtool_get_settings(dev, &cmd);
+ if (err < 0)
+ return err;
+ }
if (copy_to_user(useraddr, &cmd, sizeof(cmd)))
return -EFAULT;
+
return 0;
}
+/* Update device link settings with given ethtool_cmd.
+ *
+ * Backward compatibility note: for compatibility with legacy ethtool,
+ * this has to work with both drivers implementing set_link_ksettings
+ * API and drivers implementing set_settings API. When drivers
+ * implement set_link_ksettings and user's request updates deprecated
+ * ethtool_cmd fields (transceiver/maxrxpkt/maxtxpkt), a kernel
+ * warning is logged once (with name of 1st driver/device) to
+ * recommend user to upgrade ethtool, and the request is rejected.
+ */
static int ethtool_set_settings(struct net_device *dev, void __user *useraddr)
{
struct ethtool_cmd cmd;
- if (!dev->ethtool_ops->set_settings)
- return -EOPNOTSUPP;
+ ASSERT_RTNL();
if (copy_from_user(&cmd, useraddr, sizeof(cmd)))
return -EFAULT;
+ /* first, try new %ethtool_link_ksettings API. */
+ if (dev->ethtool_ops->set_link_ksettings) {
+ struct ethtool_link_ksettings link_ksettings;
+
+ if (!convert_legacy_settings_to_link_ksettings(&link_ksettings,
+ &cmd))
+ return -EINVAL;
+
+ link_ksettings.base.cmd = ETHTOOL_SLINKSETTINGS;
+ link_ksettings.base.link_mode_masks_nwords
+ = __ETHTOOL_LINK_MODE_MASK_NU32;
+ return dev->ethtool_ops->set_link_ksettings(dev,
+ &link_ksettings);
+ }
+
+ /* legacy %ethtool_cmd API */
+
+ /* TODO: return -EOPNOTSUPP when ethtool_ops::get_settings
+ * disappears internally
+ */
+
+ if (!dev->ethtool_ops->set_settings)
+ return -EOPNOTSUPP;
+
return dev->ethtool_ops->set_settings(dev, &cmd);
}
@@ -2252,6 +2687,12 @@ int dev_ethtool(struct net *net, struct ifreq *ifr)
case ETHTOOL_PERQUEUE:
rc = ethtool_set_per_queue(dev, useraddr);
break;
+ case ETHTOOL_GLINKSETTINGS:
+ rc = ethtool_get_link_ksettings(dev, useraddr);
+ break;
+ case ETHTOOL_SLINKSETTINGS:
+ rc = ethtool_set_link_ksettings(dev, useraddr);
+ break;
default:
rc = -EOPNOTSUPP;
}