i40e: increase max descriptors for XL710

In Tables 8-12 and 8-22 in the X710/XXV710/XL710 datasheet, the QLEN
description states that the maximum size of the descriptor queue is 8k
minus 32, or 8160.
Signed-off-by: Justin Bronder <jsbronder@cold-front.org>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Pucha Himasekhar Reddy <himasekharx.reddy.pucha@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20231113231047.548659-2-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/intel/i40e/i40e.h

@@ -24,6 +24,7 @@
 #define I40E_MAX_VEB			16
 
 #define I40E_MAX_NUM_DESCRIPTORS	4096
+#define I40E_MAX_NUM_DESCRIPTORS_XL710	8160
 #define I40E_MAX_CSR_SPACE		(4 * 1024 * 1024 - 64 * 1024)
 #define I40E_DEFAULT_NUM_DESCRIPTORS	512
 #define I40E_REQ_DESCRIPTOR_MULTIPLE	32

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -2015,6 +2015,18 @@ static void i40e_get_drvinfo(struct net_device *netdev,
 		drvinfo->n_priv_flags += I40E_GL_PRIV_FLAGS_STR_LEN;
 }
 
+static u32 i40e_get_max_num_descriptors(struct i40e_pf *pf)
+{
+	struct i40e_hw *hw = &pf->hw;
+
+	switch (hw->mac.type) {
+	case I40E_MAC_XL710:
+		return I40E_MAX_NUM_DESCRIPTORS_XL710;
+	default:
+		return I40E_MAX_NUM_DESCRIPTORS;
+	}
+}
+
 static void i40e_get_ringparam(struct net_device *netdev,
 			       struct ethtool_ringparam *ring,
 			       struct kernel_ethtool_ringparam *kernel_ring,
@@ -2024,8 +2036,8 @@ static void i40e_get_ringparam(struct net_device *netdev,
 	struct i40e_pf *pf = np->vsi->back;
 	struct i40e_vsi *vsi = pf->vsi[pf->lan_vsi];
 
-	ring->rx_max_pending = I40E_MAX_NUM_DESCRIPTORS;
-	ring->tx_max_pending = I40E_MAX_NUM_DESCRIPTORS;
+	ring->rx_max_pending = i40e_get_max_num_descriptors(pf);
+	ring->tx_max_pending = i40e_get_max_num_descriptors(pf);
 	ring->rx_mini_max_pending = 0;
 	ring->rx_jumbo_max_pending = 0;
 	ring->rx_pending = vsi->rx_rings[0]->count;
@@ -2050,12 +2062,12 @@ static int i40e_set_ringparam(struct net_device *netdev,
 			      struct kernel_ethtool_ringparam *kernel_ring,
 			      struct netlink_ext_ack *extack)
 {
+	u32 new_rx_count, new_tx_count, max_num_descriptors;
 	struct i40e_ring *tx_rings = NULL, *rx_rings = NULL;
 	struct i40e_netdev_priv *np = netdev_priv(netdev);
 	struct i40e_hw *hw = &np->vsi->back->hw;
 	struct i40e_vsi *vsi = np->vsi;
 	struct i40e_pf *pf = vsi->back;
-	u32 new_rx_count, new_tx_count;
 	u16 tx_alloc_queue_pairs;
 	int timeout = 50;
 	int i, err = 0;
@@ -2063,14 +2075,15 @@ static int i40e_set_ringparam(struct net_device *netdev,
 	if ((ring->rx_mini_pending) || (ring->rx_jumbo_pending))
 		return -EINVAL;
 
-	if (ring->tx_pending > I40E_MAX_NUM_DESCRIPTORS ||
+	max_num_descriptors = i40e_get_max_num_descriptors(pf);
+	if (ring->tx_pending > max_num_descriptors ||
 	    ring->tx_pending < I40E_MIN_NUM_DESCRIPTORS ||
-	    ring->rx_pending > I40E_MAX_NUM_DESCRIPTORS ||
+	    ring->rx_pending > max_num_descriptors ||
 	    ring->rx_pending < I40E_MIN_NUM_DESCRIPTORS) {
 		netdev_info(netdev,
 			    "Descriptors requested (Tx: %d / Rx: %d) out of range [%d-%d]\n",
 			    ring->tx_pending, ring->rx_pending,
-			    I40E_MIN_NUM_DESCRIPTORS, I40E_MAX_NUM_DESCRIPTORS);
+			    I40E_MIN_NUM_DESCRIPTORS, max_num_descriptors);
 		return -EINVAL;
 	}