[net-next,04/10] nfp: prepare for multi-part descriptors

Commit Message

Simon Horman March 18, 2022, 10:12 a.m. UTC

From: Jakub Kicinski <[e-mail]>

New datapaths may use multiple descriptor units to describe
a single packet.  Prepare for that by adding a descriptors
per simple frame constant into ring size calculations.

Signed-off-by: Jakub Kicinski <[e-mail]>
Signed-off-by: Fei Qin <[e-mail]>
Signed-off-by: Simon Horman <[e-mail]>
---
 drivers/net/ethernet/netronome/nfp/nfd3/rings.c      | 1 +
 drivers/net/ethernet/netronome/nfp/nfp_net.h         | 4 ++--
 drivers/net/ethernet/netronome/nfp/nfp_net_dp.h      | 2 ++
 drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c | 8 +++++---
 4 files changed, 10 insertions(+), 5 deletions(-)

Patch

diff --git a/drivers/net/ethernet/netronome/nfp/nfd3/rings.c b/drivers/net/ethernet/netronome/nfp/nfd3/rings.c
index 342871d23e15..3ebbedd8ba64 100644
--- a/drivers/net/ethernet/netronome/nfp/nfd3/rings.c
+++ b/drivers/net/ethernet/netronome/nfp/nfd3/rings.c
@@ -244,6 +244,7 @@  nfp_nfd3_print_tx_descs(struct seq_file *file,
 
 const struct nfp_dp_ops nfp_nfd3_ops = {
 	.version		= NFP_NFD_VER_NFD3,
+	.tx_min_desc_per_pkt	= 1,
 	.poll			= nfp_nfd3_poll,
 	.xsk_poll		= nfp_nfd3_xsk_poll,
 	.ctrl_poll		= nfp_nfd3_ctrl_poll,
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net.h b/drivers/net/ethernet/netronome/nfp/nfp_net.h
index 13a9e6731d0d..d4b82c893c2a 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net.h
@@ -441,8 +441,8 @@  struct nfp_stat_pair {
  * @ctrl_bar:		Pointer to mapped control BAR
  *
  * @ops:		Callbacks and parameters for this vNIC's NFD version
- * @txd_cnt:		Size of the TX ring in number of descriptors
- * @rxd_cnt:		Size of the RX ring in number of descriptors
+ * @txd_cnt:		Size of the TX ring in number of min size packets
+ * @rxd_cnt:		Size of the RX ring in number of min size packets
  * @num_r_vecs:		Number of used ring vectors
  * @num_tx_rings:	Currently configured number of TX rings
  * @num_stack_tx_rings:	Number of TX rings used by the stack (not XDP)
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_dp.h b/drivers/net/ethernet/netronome/nfp/nfp_net_dp.h
index 25af0e3c7af7..81be8d17fa93 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_dp.h
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_dp.h
@@ -106,6 +106,7 @@  enum nfp_nfd_version {
 /**
  * struct nfp_dp_ops - Hooks to wrap different implementation of different dp
  * @version:			Indicate dp type
+ * @tx_min_desc_per_pkt:	Minimal TX descs needed for each packet
  * @poll:			Napi poll for normal rx/tx
  * @xsk_poll:			Napi poll when xsk is enabled
  * @ctrl_poll:			Tasklet poll for ctrl rx/tx
@@ -121,6 +122,7 @@  enum nfp_nfd_version {
  */
 struct nfp_dp_ops {
 	enum nfp_nfd_version version;
+	unsigned int tx_min_desc_per_pkt;
 
 	int (*poll)(struct napi_struct *napi, int budget);
 	int (*xsk_poll)(struct napi_struct *napi, int budget);
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c b/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
index b9abae176793..7d7150600485 100644
--- a/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
+++ b/drivers/net/ethernet/netronome/nfp/nfp_net_ethtool.c
@@ -26,6 +26,7 @@ 
 #include "nfp_app.h"
 #include "nfp_main.h"
 #include "nfp_net_ctrl.h"
+#include "nfp_net_dp.h"
 #include "nfp_net.h"
 #include "nfp_port.h"
 
@@ -390,7 +391,7 @@  static void nfp_net_get_ringparam(struct net_device *netdev,
 	u32 qc_max = nn->dev_info->max_qc_size;
 
 	ring->rx_max_pending = qc_max;
-	ring->tx_max_pending = qc_max;
+	ring->tx_max_pending = qc_max / nn->dp.ops->tx_min_desc_per_pkt;
 	ring->rx_pending = nn->dp.rxd_cnt;
 	ring->tx_pending = nn->dp.txd_cnt;
 }
@@ -414,8 +415,8 @@  static int nfp_net_set_ringparam(struct net_device *netdev,
 				 struct kernel_ethtool_ringparam *kernel_ring,
 				 struct netlink_ext_ack *extack)
 {
+	u32 tx_dpp, qc_min, qc_max, rxd_cnt, txd_cnt;
 	struct nfp_net *nn = netdev_priv(netdev);
-	u32 qc_min, qc_max, rxd_cnt, txd_cnt;
 
 	/* We don't have separate queues/rings for small/large frames. */
 	if (ring->rx_mini_pending || ring->rx_jumbo_pending)
@@ -423,12 +424,13 @@  static int nfp_net_set_ringparam(struct net_device *netdev,
 
 	qc_min = nn->dev_info->min_qc_size;
 	qc_max = nn->dev_info->max_qc_size;
+	tx_dpp = nn->dp.ops->tx_min_desc_per_pkt;
 	/* Round up to supported values */
 	rxd_cnt = roundup_pow_of_two(ring->rx_pending);
 	txd_cnt = roundup_pow_of_two(ring->tx_pending);
 
 	if (rxd_cnt < qc_min || rxd_cnt > qc_max ||
-	    txd_cnt < qc_min || txd_cnt > qc_max)
+	    txd_cnt < qc_min / tx_dpp || txd_cnt > qc_max / tx_dpp)
 		return -EINVAL;
 
 	if (nn->dp.rxd_cnt == rxd_cnt && nn->dp.txd_cnt == txd_cnt)