diff --git a/Documentation/networking/ethtool-netlink.rst b/Documentation/networking/ethtool-netlink.rst
index dbca3e9ec782..65ed29e78499 100644
--- a/Documentation/networking/ethtool-netlink.rst
+++ b/Documentation/networking/ethtool-netlink.rst
@@ -426,6 +426,7 @@ Kernel response contents:
   ``ETHTOOL_A_LINKMODES_DUPLEX``              u8      duplex mode
   ``ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG``    u8      Master/slave port mode
   ``ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE``  u8      Master/slave port state
+  ``ETHTOOL_A_LINKMODES_RATE_ADAPTATION``     u8      PHY rate adaptation
   ==========================================  ======  ==========================
 
 For ``ETHTOOL_A_LINKMODES_OURS``, value represents advertised modes and mask
@@ -449,6 +450,7 @@ Request contents:
   ``ETHTOOL_A_LINKMODES_SPEED``               u32     link speed (Mb/s)
   ``ETHTOOL_A_LINKMODES_DUPLEX``              u8      duplex mode
   ``ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG``    u8      Master/slave port mode
+  ``ETHTOOL_A_LINKMODES_RATE_ADAPTATION``     u8      PHY rate adaptation
   ``ETHTOOL_A_LINKMODES_LANES``               u32     lanes
   ==========================================  ======  ==========================
 
diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c
index 2a2924bc8f76..b1c9c40fe378 100644
--- a/drivers/net/phy/phy-core.c
+++ b/drivers/net/phy/phy-core.c
@@ -74,6 +74,27 @@ const char *phy_duplex_to_str(unsigned int duplex)
 }
 EXPORT_SYMBOL_GPL(phy_duplex_to_str);
 
+/**
+ * phy_rate_adaptation_to_str - Return a string describing the rate adaptation
+ *
+ * @rate_adaptation: Type of rate adaptation to describe
+ */
+const char *phy_rate_adaptation_to_str(int rate_adaptation)
+{
+	switch (rate_adaptation) {
+	case RATE_ADAPT_NONE:
+		return "none";
+	case RATE_ADAPT_PAUSE:
+		return "pause";
+	case RATE_ADAPT_CRS:
+		return "crs";
+	case RATE_ADAPT_OPEN_LOOP:
+		return "open-loop";
+	}
+	return "Unsupported (update phy-core.c)";
+}
+EXPORT_SYMBOL_GPL(phy_rate_adaptation_to_str);
+
 /**
  * phy_interface_num_ports - Return the number of links that can be carried by
  *			     a given MAC-PHY physical link. Returns 0 if this is
diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c
index 8d3ee3a6495b..77cbf07852e6 100644
--- a/drivers/net/phy/phy.c
+++ b/drivers/net/phy/phy.c
@@ -114,6 +114,33 @@ void phy_print_status(struct phy_device *phydev)
 }
 EXPORT_SYMBOL(phy_print_status);
 
+/**
+ * phy_get_rate_adaptation - determine if rate adaptation is supported
+ * @phydev: The phy device to return rate adaptation for
+ * @iface: The interface mode to use
+ *
+ * This determines the type of rate adaptation (if any) that @phy supports
+ * using @iface. @iface may be %PHY_INTERFACE_MODE_NA to determine if any
+ * interface supports rate adaptation.
+ *
+ * Return: The type of rate adaptation @phy supports for @iface, or
+ *         %RATE_ADAPT_NONE.
+ */
+int phy_get_rate_adaptation(struct phy_device *phydev,
+			    phy_interface_t iface)
+{
+	int ret = RATE_ADAPT_NONE;
+
+	if (phydev->drv->get_rate_adaptation) {
+		mutex_lock(&phydev->lock);
+		ret = phydev->drv->get_rate_adaptation(phydev, iface);
+		mutex_unlock(&phydev->lock);
+	}
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(phy_get_rate_adaptation);
+
 /**
  * phy_config_interrupt - configure the PHY device for the requested interrupts
  * @phydev: the phy_device struct
@@ -256,6 +283,7 @@ void phy_ethtool_ksettings_get(struct phy_device *phydev,
 	cmd->base.duplex = phydev->duplex;
 	cmd->base.master_slave_cfg = phydev->master_slave_get;
 	cmd->base.master_slave_state = phydev->master_slave_state;
+	cmd->base.rate_adaptation = phydev->rate_adaptation;
 	if (phydev->interface == PHY_INTERFACE_MODE_MOCA)
 		cmd->base.port = PORT_BNC;
 	else
diff --git a/include/linux/phy.h b/include/linux/phy.h
index 337230c135f7..3e784137b2f3 100644
--- a/include/linux/phy.h
+++ b/include/linux/phy.h
@@ -280,7 +280,6 @@ static inline const char *phy_modes(phy_interface_t interface)
 	}
 }
 
-
 #define PHY_INIT_TIMEOUT	100000
 #define PHY_FORCE_TIMEOUT	10
 
@@ -574,6 +573,7 @@ struct macsec_ops;
  * @lp_advertising: Current link partner advertised linkmodes
  * @eee_broken_modes: Energy efficient ethernet modes which should be prohibited
  * @autoneg: Flag autoneg being used
+ * @rate_adaptation: Current rate adaptation mode
  * @link: Current link state
  * @autoneg_complete: Flag auto negotiation of the link has completed
  * @mdix: Current crossover
@@ -641,6 +641,8 @@ struct phy_device {
 	unsigned irq_suspended:1;
 	unsigned irq_rerun:1;
 
+	int rate_adaptation;
+
 	enum phy_state state;
 
 	u32 dev_flags;
@@ -805,6 +807,21 @@ struct phy_driver {
 	 */
 	int (*get_features)(struct phy_device *phydev);
 
+	/**
+	 * @get_rate_adaptation: Get the supported type of rate adaptation for a
+	 * particular phy interface. This is used by phy consumers to determine
+	 * whether to advertise lower-speed modes for that interface. It is
+	 * assumed that if a rate adaptation mode is supported on an interface,
+	 * then that interface's rate can be adapted to all slower link speeds
+	 * supported by the phy. If iface is %PHY_INTERFACE_MODE_NA, and the phy
+	 * supports any kind of rate adaptation for any interface, then it must
+	 * return that rate adaptation mode (preferring %RATE_ADAPT_PAUSE to
+	 * %RATE_ADAPT_CRS). If the interface is not supported, this should
+	 * return %RATE_ADAPT_NONE.
+	 */
+	int (*get_rate_adaptation)(struct phy_device *phydev,
+				   phy_interface_t iface);
+
 	/* PHY Power Management */
 	/** @suspend: Suspend the hardware, saving state if needed */
 	int (*suspend)(struct phy_device *phydev);
@@ -971,6 +988,7 @@ struct phy_fixup {
 
 const char *phy_speed_to_str(int speed);
 const char *phy_duplex_to_str(unsigned int duplex);
+const char *phy_rate_adaptation_to_str(int rate_adaptation);
 
 int phy_interface_num_ports(phy_interface_t interface);
 
@@ -1687,6 +1705,8 @@ int phy_disable_interrupts(struct phy_device *phydev);
 void phy_request_interrupt(struct phy_device *phydev);
 void phy_free_interrupt(struct phy_device *phydev);
 void phy_print_status(struct phy_device *phydev);
+int phy_get_rate_adaptation(struct phy_device *phydev,
+			    phy_interface_t iface);
 void phy_set_max_speed(struct phy_device *phydev, u32 max_speed);
 void phy_remove_link_mode(struct phy_device *phydev, u32 link_mode);
 void phy_advertise_supported(struct phy_device *phydev);
diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h
index 2d5741fd44bb..49496acbeac9 100644
--- a/include/uapi/linux/ethtool.h
+++ b/include/uapi/linux/ethtool.h
@@ -1840,6 +1840,20 @@ static inline int ethtool_validate_duplex(__u8 duplex)
 #define MASTER_SLAVE_STATE_SLAVE		3
 #define MASTER_SLAVE_STATE_ERR			4
 
+/* These are used to throttle the rate of data on the phy interface when the
+ * native speed of the interface is higher than the link speed. These should
+ * not be used for phy interfaces which natively support multiple speeds (e.g.
+ * MII or SGMII).
+ */
+/* No rate adaptation performed. */
+#define RATE_ADAPT_NONE		0
+/* The phy sends pause frames to throttle the MAC. */
+#define RATE_ADAPT_PAUSE	1
+/* The phy asserts CRS to prevent the MAC from transmitting. */
+#define RATE_ADAPT_CRS		2
+/* The MAC is programmed with a sufficiently-large IPG. */
+#define RATE_ADAPT_OPEN_LOOP	3
+
 /* Which connector port. */
 #define PORT_TP			0x00
 #define PORT_AUI		0x01
@@ -2033,8 +2047,8 @@ enum ethtool_reset_flags {
  *	reported consistently by PHYLIB.  Read-only.
  * @master_slave_cfg: Master/slave port mode.
  * @master_slave_state: Master/slave port state.
+ * @rate_adaptation: Rate adaptation performed by the PHY
  * @reserved: Reserved for future use; see the note on reserved space.
- * @reserved1: Reserved for future use; see the note on reserved space.
  * @link_mode_masks: Variable length bitmaps.
  *
  * If autonegotiation is disabled, the speed and @duplex represent the
@@ -2085,7 +2099,7 @@ struct ethtool_link_settings {
 	__u8	transceiver;
 	__u8	master_slave_cfg;
 	__u8	master_slave_state;
-	__u8	reserved1[1];
+	__u8	rate_adaptation;
 	__u32	reserved[7];
 	__u32	link_mode_masks[];
 	/* layout of link_mode_masks fields:
diff --git a/include/uapi/linux/ethtool_netlink.h b/include/uapi/linux/ethtool_netlink.h
index d2fb4f7be61b..3a5d81769ff4 100644
--- a/include/uapi/linux/ethtool_netlink.h
+++ b/include/uapi/linux/ethtool_netlink.h
@@ -242,6 +242,7 @@ enum {
 	ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG,	/* u8 */
 	ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE,	/* u8 */
 	ETHTOOL_A_LINKMODES_LANES,		/* u32 */
+	ETHTOOL_A_LINKMODES_RATE_ADAPTATION,	/* u8 */
 
 	/* add new constants above here */
 	__ETHTOOL_A_LINKMODES_CNT,
diff --git a/net/ethtool/ioctl.c b/net/ethtool/ioctl.c
index 9298eb3251cb..6166f3e6b8d5 100644
--- a/net/ethtool/ioctl.c
+++ b/net/ethtool/ioctl.c
@@ -571,6 +571,7 @@ static int ethtool_get_link_ksettings(struct net_device *dev,
 		= __ETHTOOL_LINK_MODE_MASK_NU32;
 	link_ksettings.base.master_slave_cfg = MASTER_SLAVE_CFG_UNSUPPORTED;
 	link_ksettings.base.master_slave_state = MASTER_SLAVE_STATE_UNSUPPORTED;
+	link_ksettings.base.rate_adaptation = RATE_ADAPT_NONE;
 
 	return store_link_ksettings_for_user(useraddr, &link_ksettings);
 }
diff --git a/net/ethtool/linkmodes.c b/net/ethtool/linkmodes.c
index 99b29b4fe947..7905bd985c7f 100644
--- a/net/ethtool/linkmodes.c
+++ b/net/ethtool/linkmodes.c
@@ -70,6 +70,7 @@ static int linkmodes_reply_size(const struct ethnl_req_info *req_base,
 		+ 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_ADAPTATION */
 		+ 0;
 	ret = ethnl_bitset_size(ksettings->link_modes.advertising,
 				ksettings->link_modes.supported,
@@ -143,6 +144,10 @@ static int linkmodes_fill_reply(struct sk_buff *skb,
 		       lsettings->master_slave_state))
 		return -EMSGSIZE;
 
+	if (nla_put_u8(skb, ETHTOOL_A_LINKMODES_RATE_ADAPTATION,
+		       lsettings->rate_adaptation))
+		return -EMSGSIZE;
+
 	return 0;
 }
 
