Merge branch 'ethtool-mac-merge'

Vladimir Oltean says:

====================
ethtool support for IEEE 802.3 MAC Merge layer

Change log
----------

v3->v4:
- add missing opening bracket in ocelot_port_mm_irq()
- moved cfg.verify_time range checking so that it actually takes place
  for the updated rather than old value
v3 at:
https://patchwork.kernel.org/project/netdevbpf/cover/[email protected]/

v2->v3:
- made get_mm return int instead of void
- deleted ETHTOOL_A_MM_SUPPORTED
- renamed ETHTOOL_A_MM_ADD_FRAG_SIZE to ETHTOOL_A_MM_TX_MIN_FRAG_SIZE
- introduced ETHTOOL_A_MM_RX_MIN_FRAG_SIZE
- cleaned up documentation
- rebased on top of PLCA changes
- renamed ETHTOOL_STATS_SRC_* to ETHTOOL_MAC_STATS_SRC_*
v2 at:
https://patchwork.kernel.org/project/netdevbpf/cover/[email protected]/

v1->v2:
I've decided to focus just on the MAC Merge layer for now, which is why
I am able to submit this patch set as non-RFC.
v1 (RFC) at:
https://patchwork.kernel.org/project/netdevbpf/cover/[email protected]/

What is being introduced
------------------------

TL;DR: a MAC Merge layer as defined by IEEE 802.3-2018, clause 99
(interspersing of express traffic). This is controlled through ethtool
netlink (ETHTOOL_MSG_MM_GET, ETHTOOL_MSG_MM_SET). The raw ethtool
commands are posted here:
https://patchwork.kernel.org/project/netdevbpf/cover/[email protected]/

The MAC Merge layer has its own statistics counters
(ethtool --include-statistics --show-mm swp0) as well as two member
MACs, the statistics of which can be queried individually, through a new
ethtool netlink attribute, corresponding to:

$ ethtool -I --show-pause eno2 --src aggregate
$ ethtool -S eno2 --groups eth-mac eth-phy eth-ctrl rmon -- --src pmac

The core properties of the MAC Merge layer are described in great detail
in patches 02/12 and 03/12. They can be viewed in "make htmldocs" format.

Devices for which the API is supported
--------------------------------------

I decided to start with the Ethernet switch on NXP LS1028A (Felix)
because of the smaller patch set. I also have support for the ENETC
controller pending.

I would like to get confirmation that the UAPI being proposed here will
not restrict any use cases known by other hardware vendors.

Why is support for preemptible traffic classes not here?
--------------------------------------------------------

There is legitimate concern whether the 802.1Q portion of the standard
(which traffic classes go to the eMAC and which to the pMAC) should be
modeled in Linux using tc or using another UAPI. I think that is
stalling the entire series, but should be discussed separately instead.
Removing FP adminStatus support makes me confident enough to submit this
patch set without an RFC tag (meaning: I wouldn't mind if it was merged
as is).

What is submitted here is sufficient for an LLDP daemon to do its job.
I've patched openlldp to advertise and configure frame preemption:
https://github.com/vladimiroltean/openlldp/tree/frame-preemption-v3

In case someone wants to try it out, here are some commands I've used.

 # Configure the interfaces to receive and transmit LLDP Data Units
 lldptool -L -i eno0 adminStatus=rxtx
 lldptool -L -i swp0 adminStatus=rxtx
 # Enable the transmission of certain TLVs on switch's interface
 lldptool -T -i eno0 -V addEthCap enableTx=yes
 lldptool -T -i swp0 -V addEthCap enableTx=yes
 # Query LLDP statistics on switch's interface
 lldptool -S -i swp0
 # Query the received neighbor TLVs
 lldptool -i swp0 -t -n -V addEthCap
 Additional Ethernet Capabilities TLV
         Preemption capability supported
         Preemption capability enabled
         Preemption capability active
         Additional fragment size: 60 octets

So using this patch set, lldpad will be able to advertise and configure
frame preemption, but still, no data packet will be sent as preemptible
over the link, because there is no UAPI to control which traffic classes
are sent as preemptible and which as express.

Preemptable or preemptible?
---------------------------

IEEE 802.3 uses "preemptable" throughout. IEEE 802.1Q uses "preemptible"
throughout. Because the definition of "preemptible" falls under 802.1Q's
jurisdiction and 802.3 just references it, I went with the 802.1Q naming
even where supporting an 802.3 feature. Also, checkpatch agrees with this.
====================

Signed-off-by: David S. Miller <[email protected]>

1 files changed, 209 insertions, 39 deletions

diff --git a/include/linux/ethtool.h b/include/linux/ethtool.h
index 20d197693d34..6a8253d3fea8 100644
--- a/include/linux/ethtool.h
+++ b/include/linux/ethtool.h
@@ -15,6 +15,7 @@
 
 #include <linux/bitmap.h>
 #include <linux/compat.h>
+#include <linux/if_ether.h>
 #include <linux/netlink.h>
 #include <uapi/linux/ethtool.h>
 
@@ -106,11 +107,6 @@ enum ethtool_supported_ring_param {
 struct net_device;
 struct netlink_ext_ack;
 
-/* Some generic methods drivers may use in their ethtool_ops */
-u32 ethtool_op_get_link(struct net_device *dev);
-int ethtool_op_get_ts_info(struct net_device *dev, struct ethtool_ts_info *eti);
-
-
 /* Link extended state and substate. */
 struct ethtool_link_ext_state_info {
 	enum ethtool_link_ext_state link_ext_state;
@@ -311,48 +307,59 @@ static inline void ethtool_stats_init(u64 *stats, unsigned int n)
  * via a more targeted API.
  */
 struct ethtool_eth_mac_stats {
-	u64 FramesTransmittedOK;
-	u64 SingleCollisionFrames;
-	u64 MultipleCollisionFrames;
-	u64 FramesReceivedOK;
-	u64 FrameCheckSequenceErrors;
-	u64 AlignmentErrors;
-	u64 OctetsTransmittedOK;
-	u64 FramesWithDeferredXmissions;
-	u64 LateCollisions;
-	u64 FramesAbortedDueToXSColls;
-	u64 FramesLostDueToIntMACXmitError;
-	u64 CarrierSenseErrors;
-	u64 OctetsReceivedOK;
-	u64 FramesLostDueToIntMACRcvError;
-	u64 MulticastFramesXmittedOK;
-	u64 BroadcastFramesXmittedOK;
-	u64 FramesWithExcessiveDeferral;
-	u64 MulticastFramesReceivedOK;
-	u64 BroadcastFramesReceivedOK;
-	u64 InRangeLengthErrors;
-	u64 OutOfRangeLengthField;
-	u64 FrameTooLongErrors;
+	enum ethtool_mac_stats_src src;
+	struct_group(stats,
+		u64 FramesTransmittedOK;
+		u64 SingleCollisionFrames;
+		u64 MultipleCollisionFrames;
+		u64 FramesReceivedOK;
+		u64 FrameCheckSequenceErrors;
+		u64 AlignmentErrors;
+		u64 OctetsTransmittedOK;
+		u64 FramesWithDeferredXmissions;
+		u64 LateCollisions;
+		u64 FramesAbortedDueToXSColls;
+		u64 FramesLostDueToIntMACXmitError;
+		u64 CarrierSenseErrors;
+		u64 OctetsReceivedOK;
+		u64 FramesLostDueToIntMACRcvError;
+		u64 MulticastFramesXmittedOK;
+		u64 BroadcastFramesXmittedOK;
+		u64 FramesWithExcessiveDeferral;
+		u64 MulticastFramesReceivedOK;
+		u64 BroadcastFramesReceivedOK;
+		u64 InRangeLengthErrors;
+		u64 OutOfRangeLengthField;
+		u64 FrameTooLongErrors;
+	);
 };
 
 /* Basic IEEE 802.3 PHY statistics (30.3.2.1.*), not otherwise exposed
  * via a more targeted API.
  */
 struct ethtool_eth_phy_stats {
-	u64 SymbolErrorDuringCarrier;
+	enum ethtool_mac_stats_src src;
+	struct_group(stats,
+		u64 SymbolErrorDuringCarrier;
+	);
 };
 
 /* Basic IEEE 802.3 MAC Ctrl statistics (30.3.3.*), not otherwise exposed
  * via a more targeted API.
  */
 struct ethtool_eth_ctrl_stats {
-	u64 MACControlFramesTransmitted;
-	u64 MACControlFramesReceived;
-	u64 UnsupportedOpcodesReceived;
+	enum ethtool_mac_stats_src src;
+	struct_group(stats,
+		u64 MACControlFramesTransmitted;
+		u64 MACControlFramesReceived;
+		u64 UnsupportedOpcodesReceived;
+	);
 };
 
 /**
  * struct ethtool_pause_stats - statistics for IEEE 802.3x pause frames
+ * @src: input field denoting whether stats should be queried from the eMAC or
+ *	pMAC (if the MM layer is supported). To be ignored otherwise.
  * @tx_pause_frames: transmitted pause frame count. Reported to user space
  *	as %ETHTOOL_A_PAUSE_STAT_TX_FRAMES.
  *
@@ -366,8 +373,11 @@ struct ethtool_eth_ctrl_stats {
  *	from the standard.
  */
 struct ethtool_pause_stats {
-	u64 tx_pause_frames;
-	u64 rx_pause_frames;
+	enum ethtool_mac_stats_src src;
+	struct_group(stats,
+		u64 tx_pause_frames;
+		u64 rx_pause_frames;
+	);
 };
 
 #define ETHTOOL_MAX_LANES	8
@@ -417,6 +427,8 @@ struct ethtool_rmon_hist_range {
 
 /**
  * struct ethtool_rmon_stats - selected RMON (RFC 2819) statistics
+ * @src: input field denoting whether stats should be queried from the eMAC or
+ *	pMAC (if the MM layer is supported). To be ignored otherwise.
  * @undersize_pkts: Equivalent to `etherStatsUndersizePkts` from the RFC.
  * @oversize_pkts: Equivalent to `etherStatsOversizePkts` from the RFC.
  * @fragments: Equivalent to `etherStatsFragments` from the RFC.
@@ -432,13 +444,16 @@ struct ethtool_rmon_hist_range {
  * ranges is left to the driver.
  */
 struct ethtool_rmon_stats {
-	u64 undersize_pkts;
-	u64 oversize_pkts;
-	u64 fragments;
-	u64 jabbers;
+	enum ethtool_mac_stats_src src;
+	struct_group(stats,
+		u64 undersize_pkts;
+		u64 oversize_pkts;
+		u64 fragments;
+		u64 jabbers;
 
-	u64 hist[ETHTOOL_RMON_HIST_MAX];
-	u64 hist_tx[ETHTOOL_RMON_HIST_MAX];
+		u64 hist[ETHTOOL_RMON_HIST_MAX];
+		u64 hist_tx[ETHTOOL_RMON_HIST_MAX];
+	);
 };
 
 #define ETH_MODULE_EEPROM_PAGE_LEN	128
@@ -478,6 +493,98 @@ struct ethtool_module_power_mode_params {
 };
 
 /**
+ * struct ethtool_mm_state - 802.3 MAC merge layer state
+ * @verify_time:
+ *	wait time between verification attempts in ms (according to clause
+ *	30.14.1.6 aMACMergeVerifyTime)
+ * @max_verify_time:
+ *	maximum accepted value for the @verify_time variable in set requests
+ * @verify_status:
+ *	state of the verification state machine of the MM layer (according to
+ *	clause 30.14.1.2 aMACMergeStatusVerify)
+ * @tx_enabled:
+ *	set if the MM layer is administratively enabled in the TX direction
+ *	(according to clause 30.14.1.3 aMACMergeEnableTx)
+ * @tx_active:
+ *	set if the MM layer is enabled in the TX direction, which makes FP
+ *	possible (according to 30.14.1.5 aMACMergeStatusTx). This should be
+ *	true if MM is enabled, and the verification status is either verified,
+ *	or disabled.
+ * @pmac_enabled:
+ *	set if the preemptible MAC is powered on and is able to receive
+ *	preemptible packets and respond to verification frames.
+ * @verify_enabled:
+ *	set if the Verify function of the MM layer (which sends SMD-V
+ *	verification requests) is administratively enabled (regardless of
+ *	whether it is currently in the ETHTOOL_MM_VERIFY_STATUS_DISABLED state
+ *	or not), according to clause 30.14.1.4 aMACMergeVerifyDisableTx (but
+ *	using positive rather than negative logic). The device should always
+ *	respond to received SMD-V requests as long as @pmac_enabled is set.
+ * @tx_min_frag_size:
+ *	the minimum size of non-final mPacket fragments that the link partner
+ *	supports receiving, expressed in octets. Compared to the definition
+ *	from clause 30.14.1.7 aMACMergeAddFragSize which is expressed in the
+ *	range 0 to 3 (requiring a translation to the size in octets according
+ *	to the formula 64 * (1 + addFragSize) - 4), a value in a continuous and
+ *	unbounded range can be specified here.
+ * @rx_min_frag_size:
+ *	the minimum size of non-final mPacket fragments that this device
+ *	supports receiving, expressed in octets.
+ */
+struct ethtool_mm_state {
+	u32 verify_time;
+	u32 max_verify_time;
+	enum ethtool_mm_verify_status verify_status;
+	bool tx_enabled;
+	bool tx_active;
+	bool pmac_enabled;
+	bool verify_enabled;
+	u32 tx_min_frag_size;
+	u32 rx_min_frag_size;
+};
+
+/**
+ * struct ethtool_mm_cfg - 802.3 MAC merge layer configuration
+ * @verify_time: see struct ethtool_mm_state
+ * @verify_enabled: see struct ethtool_mm_state
+ * @tx_enabled: see struct ethtool_mm_state
+ * @pmac_enabled: see struct ethtool_mm_state
+ * @tx_min_frag_size: see struct ethtool_mm_state
+ */
+struct ethtool_mm_cfg {
+	u32 verify_time;
+	bool verify_enabled;
+	bool tx_enabled;
+	bool pmac_enabled;
+	u32 tx_min_frag_size;
+};
+
+/**
+ * struct ethtool_mm_stats - 802.3 MAC merge layer statistics
+ * @MACMergeFrameAssErrorCount:
+ *	received MAC frames with reassembly errors
+ * @MACMergeFrameSmdErrorCount:
+ *	received MAC frames/fragments rejected due to unknown or incorrect SMD
+ * @MACMergeFrameAssOkCount:
+ *	received MAC frames that were successfully reassembled and passed up
+ * @MACMergeFragCountRx:
+ *	number of additional correct SMD-C mPackets received due to preemption
+ * @MACMergeFragCountTx:
+ *	number of additional mPackets sent due to preemption
+ * @MACMergeHoldCount:
+ *	number of times the MM layer entered the HOLD state, which blocks
+ *	transmission of preemptible traffic
+ */
+struct ethtool_mm_stats {
+	u64 MACMergeFrameAssErrorCount;
+	u64 MACMergeFrameSmdErrorCount;
+	u64 MACMergeFrameAssOkCount;
+	u64 MACMergeFragCountRx;
+	u64 MACMergeFragCountTx;
+	u64 MACMergeHoldCount;
+};
+
+/**
  * struct ethtool_ops - optional netdev operations
  * @cap_link_lanes_supported: indicates if the driver supports lanes
  *	parameter.
@@ -649,6 +756,9 @@ struct ethtool_module_power_mode_params {
  *	plugged-in.
  * @set_module_power_mode: Set the power mode policy for the plug-in module
  *	used by the network device.
+ * @get_mm: Query the 802.3 MAC Merge layer state.
+ * @set_mm: Set the 802.3 MAC Merge layer parameters.
+ * @get_mm_stats: Query the 802.3 MAC Merge layer statistics.
  *
  * All operations are optional (i.e. the function pointer may be set
  * to %NULL) and callers must take this into account.  Callers must
@@ -787,6 +897,10 @@ struct ethtool_ops {
 	int	(*set_module_power_mode)(struct net_device *dev,
 					 const struct ethtool_module_power_mode_params *params,
 					 struct netlink_ext_ack *extack);
+	int	(*get_mm)(struct net_device *dev, struct ethtool_mm_state *state);
+	int	(*set_mm)(struct net_device *dev, struct ethtool_mm_cfg *cfg,
+			  struct netlink_ext_ack *extack);
+	void	(*get_mm_stats)(struct net_device *dev, struct ethtool_mm_stats *stats);
 };
 
 int ethtool_check_ops(const struct ethtool_ops *ops);
@@ -873,6 +987,62 @@ ethtool_params_from_link_mode(struct ethtool_link_ksettings *link_ksettings,
  */
 int ethtool_get_phc_vclocks(struct net_device *dev, int **vclock_index);
 
+/* Some generic methods drivers may use in their ethtool_ops */
+u32 ethtool_op_get_link(struct net_device *dev);
+int ethtool_op_get_ts_info(struct net_device *dev, struct ethtool_ts_info *eti);
+
+void ethtool_aggregate_mac_stats(struct net_device *dev,
+				 struct ethtool_eth_mac_stats *mac_stats);
+void ethtool_aggregate_phy_stats(struct net_device *dev,
+				 struct ethtool_eth_phy_stats *phy_stats);
+void ethtool_aggregate_ctrl_stats(struct net_device *dev,
+				  struct ethtool_eth_ctrl_stats *ctrl_stats);
+void ethtool_aggregate_pause_stats(struct net_device *dev,
+				   struct ethtool_pause_stats *pause_stats);
+void ethtool_aggregate_rmon_stats(struct net_device *dev,
+				  struct ethtool_rmon_stats *rmon_stats);
+
+/**
+ * ethtool_mm_frag_size_add_to_min - Translate (standard) additional fragment
+ *	size expressed as multiplier into (absolute) minimum fragment size
+ *	value expressed in octets
+ * @val_add: Value of addFragSize multiplier
+ */
+static inline u32 ethtool_mm_frag_size_add_to_min(u32 val_add)
+{
+	return (ETH_ZLEN + ETH_FCS_LEN) * (1 + val_add) - ETH_FCS_LEN;
+}
+
+/**
+ * ethtool_mm_frag_size_min_to_add - Translate (absolute) minimum fragment size
+ *	expressed in octets into (standard) additional fragment size expressed
+ *	as multiplier
+ * @val_min: Value of addFragSize variable in octets
+ * @val_add: Pointer where the standard addFragSize value is to be returned
+ * @extack: Netlink extended ack
+ *
+ * Translate a value in octets to one of 0, 1, 2, 3 according to the reverse
+ * application of the 802.3 formula 64 * (1 + addFragSize) - 4. To be called
+ * by drivers which do not support programming the minimum fragment size to a
+ * continuous range. Returns error on other fragment length values.
+ */
+static inline int ethtool_mm_frag_size_min_to_add(u32 val_min, u32 *val_add,
+						  struct netlink_ext_ack *extack)
+{
+	u32 add_frag_size;
+
+	for (add_frag_size = 0; add_frag_size < 4; add_frag_size++) {
+		if (ethtool_mm_frag_size_add_to_min(add_frag_size) == val_min) {
+			*val_add = add_frag_size;
+			return 0;
+		}
+	}
+
+	NL_SET_ERR_MSG_MOD(extack,
+			   "minFragSize required to be one of 60, 124, 188 or 252");
+	return -EINVAL;
+}
+
 /**
  * ethtool_sprintf - Write formatted string to ethtool string data
  * @data: Pointer to start of string to update