ice: add E830 Earliest TxTime First Offload support

E830 supports Earliest TxTime First (ETF) hardware offload, which is
configured via the ETF Qdisc on a per-queue basis (see tc-etf(8)). ETF
introduces a new Tx flow mechanism that utilizes a timestamp ring
(tstamp_ring) alongside the standard Tx ring. This timestamp ring is
used to indicate when hardware will transmit a packet. Tx Time is
supported on the first 2048 Tx queues of the device, and the NVM image
limits the maximum number of Tx queues to 2048 for the device.

The allocation and initialization of the timestamp ring occur when the
feature is enabled on a specific Tx queue via tc-etf. The requested Tx
Time queue index cannot be greater than the number of Tx queues
(vsi->num_txq).

To support ETF, the following flags and bitmap are introduced:

 - ICE_F_TXTIME: Device feature flag set for E830 NICs, indicating ETF
   support.
 - txtime_txqs: PF-level bitmap set when ETF is enabled and cleared
   when disabled for a specific Tx queue. It is used by
   ice_is_txtime_ena() to check if ETF is allocated and configured on
   any Tx queue, which is checked during Tx ring allocation.
 - ICE_TX_FLAGS_TXTIME: Per Tx ring flag set when ETF is allocated and
   configured for a specific Tx queue. It determines ETF status during
   packet transmission and is checked by ice_is_txtime_ena() to verify
   if ETF is enabled on any Tx queue.

Due to a hardware issue that can result in a malicious driver detection
event, additional timestamp descriptors are required when wrapping
around the timestamp ring. Up to 64 additional timestamp descriptors
are reserved, reducing the available Tx descriptors.

To accommodate this, ICE_MAX_NUM_DESC_BY_MAC is introduced, defining:

 - E830: Maximum Tx descriptor count of 8096 (8K - 32 - 64 for timestamp
   fetch descriptors).
 - E810 and E82X: Maximum Tx descriptor count of 8160 (8K - 32).

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Co-developed-by: Alice Michael <alice.michael@intel.com>
Signed-off-by: Alice Michael <alice.michael@intel.com>
Signed-off-by: Paul Greenwalt <paul.greenwalt@intel.com>
Acked-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Tested-by: Rinitha S <sx.rinitha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 15 insertions, 0 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.h b/drivers/net/ethernet/intel/ice/ice_txrx.h
index 2fd8e78178a2..841a07bfba54 100644
--- a/drivers/net/ethernet/intel/ice/ice_txrx.h
+++ b/drivers/net/ethernet/intel/ice/ice_txrx.h
@@ -310,6 +310,16 @@ enum ice_dynamic_itr {
 #define ICE_TX_LEGACY	1
 
 /* descriptor ring, associated with a VSI */
+struct ice_tstamp_ring {
+	struct ice_tx_ring *tx_ring;	/* Backreference to associated Tx ring */
+	dma_addr_t dma;			/* physical address of ring */
+	struct rcu_head rcu;            /* to avoid race on free */
+	u8 __iomem *tail;
+	void *desc;
+	u16 next_to_use;
+	u16 count;
+} ____cacheline_internodealigned_in_smp;
+
 struct ice_rx_ring {
 	/* CL1 - 1st cacheline starts here */
 	void *desc;			/* Descriptor ring memory */
@@ -402,9 +412,11 @@ struct ice_tx_ring {
 	spinlock_t tx_lock;
 	u32 txq_teid;			/* Added Tx queue TEID */
 	/* CL4 - 4th cacheline starts here */
+	struct ice_tstamp_ring *tstamp_ring;
 #define ICE_TX_FLAGS_RING_XDP		BIT(0)
 #define ICE_TX_FLAGS_RING_VLAN_L2TAG1	BIT(1)
 #define ICE_TX_FLAGS_RING_VLAN_L2TAG2	BIT(2)
+#define ICE_TX_FLAGS_TXTIME		BIT(3)
 	u8 flags;
 	u8 dcb_tc;			/* Traffic class of ring */
 	u16 quanta_prof_id;
@@ -500,6 +512,7 @@ void ice_clean_tx_ring(struct ice_tx_ring *tx_ring);
 void ice_clean_rx_ring(struct ice_rx_ring *rx_ring);
 int ice_setup_tx_ring(struct ice_tx_ring *tx_ring);
 int ice_setup_rx_ring(struct ice_rx_ring *rx_ring);
+int ice_alloc_setup_tstamp_ring(struct ice_tx_ring *tx_ring);
 void ice_free_tx_ring(struct ice_tx_ring *tx_ring);
 void ice_free_rx_ring(struct ice_rx_ring *rx_ring);
 int ice_napi_poll(struct napi_struct *napi, int budget);
@@ -508,4 +521,6 @@ ice_prgm_fdir_fltr(struct ice_vsi *vsi, struct ice_fltr_desc *fdir_desc,
 		   u8 *raw_packet);
 void ice_clean_ctrl_tx_irq(struct ice_tx_ring *tx_ring);
 void ice_clean_ctrl_rx_irq(struct ice_rx_ring *rx_ring);
+void ice_free_tx_tstamp_ring(struct ice_tx_ring *tx_ring);
+void ice_free_tstamp_ring(struct ice_tx_ring *tx_ring);
 #endif /* _ICE_TXRX_H_ */