1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // mcp251xfd - Microchip MCP251xFD Family CAN controller driver
4 //
5 // Copyright (c) 2021, 2022 Pengutronix,
6 //               Marc Kleine-Budde <kernel@pengutronix.de>
7 //
8 
9 #include <linux/ethtool.h>
10 
11 #include "mcp251xfd.h"
12 #include "mcp251xfd-ram.h"
13 
14 static void
mcp251xfd_ring_get_ringparam(struct net_device * ndev,struct ethtool_ringparam * ring,struct kernel_ethtool_ringparam * kernel_ring,struct netlink_ext_ack * extack)15 mcp251xfd_ring_get_ringparam(struct net_device *ndev,
16 			     struct ethtool_ringparam *ring,
17 			     struct kernel_ethtool_ringparam *kernel_ring,
18 			     struct netlink_ext_ack *extack)
19 {
20 	const struct mcp251xfd_priv *priv = netdev_priv(ndev);
21 	const bool fd_mode = mcp251xfd_is_fd_mode(priv);
22 	struct can_ram_layout layout;
23 
24 	can_ram_get_layout(&layout, &mcp251xfd_ram_config, NULL, NULL, fd_mode);
25 	ring->rx_max_pending = layout.max_rx;
26 	ring->tx_max_pending = layout.max_tx;
27 
28 	ring->rx_pending = priv->rx_obj_num;
29 	ring->tx_pending = priv->tx->obj_num;
30 }
31 
32 static int
mcp251xfd_ring_set_ringparam(struct net_device * ndev,struct ethtool_ringparam * ring,struct kernel_ethtool_ringparam * kernel_ring,struct netlink_ext_ack * extack)33 mcp251xfd_ring_set_ringparam(struct net_device *ndev,
34 			     struct ethtool_ringparam *ring,
35 			     struct kernel_ethtool_ringparam *kernel_ring,
36 			     struct netlink_ext_ack *extack)
37 {
38 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
39 	const bool fd_mode = mcp251xfd_is_fd_mode(priv);
40 	struct can_ram_layout layout;
41 
42 	can_ram_get_layout(&layout, &mcp251xfd_ram_config, ring, NULL, fd_mode);
43 	if ((layout.cur_rx != priv->rx_obj_num ||
44 	     layout.cur_tx != priv->tx->obj_num) &&
45 	    netif_running(ndev))
46 		return -EBUSY;
47 
48 	priv->rx_obj_num = layout.cur_rx;
49 	priv->rx_obj_num_coalesce_irq = layout.rx_coalesce;
50 	priv->tx->obj_num = layout.cur_tx;
51 	priv->tx_obj_num_coalesce_irq = layout.tx_coalesce;
52 
53 	return 0;
54 }
55 
mcp251xfd_ring_get_coalesce(struct net_device * ndev,struct ethtool_coalesce * ec,struct kernel_ethtool_coalesce * kec,struct netlink_ext_ack * ext_ack)56 static int mcp251xfd_ring_get_coalesce(struct net_device *ndev,
57 				       struct ethtool_coalesce *ec,
58 				       struct kernel_ethtool_coalesce *kec,
59 				       struct netlink_ext_ack *ext_ack)
60 {
61 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
62 	u32 rx_max_frames, tx_max_frames;
63 
64 	/* The ethtool doc says:
65 	 * To disable coalescing, set usecs = 0 and max_frames = 1.
66 	 */
67 	if (priv->rx_obj_num_coalesce_irq == 0)
68 		rx_max_frames = 1;
69 	else
70 		rx_max_frames = priv->rx_obj_num_coalesce_irq;
71 
72 	ec->rx_max_coalesced_frames_irq = rx_max_frames;
73 	ec->rx_coalesce_usecs_irq = priv->rx_coalesce_usecs_irq;
74 
75 	if (priv->tx_obj_num_coalesce_irq == 0)
76 		tx_max_frames = 1;
77 	else
78 		tx_max_frames = priv->tx_obj_num_coalesce_irq;
79 
80 	ec->tx_max_coalesced_frames_irq = tx_max_frames;
81 	ec->tx_coalesce_usecs_irq = priv->tx_coalesce_usecs_irq;
82 
83 	return 0;
84 }
85 
mcp251xfd_ring_set_coalesce(struct net_device * ndev,struct ethtool_coalesce * ec,struct kernel_ethtool_coalesce * kec,struct netlink_ext_ack * ext_ack)86 static int mcp251xfd_ring_set_coalesce(struct net_device *ndev,
87 				       struct ethtool_coalesce *ec,
88 				       struct kernel_ethtool_coalesce *kec,
89 				       struct netlink_ext_ack *ext_ack)
90 {
91 	struct mcp251xfd_priv *priv = netdev_priv(ndev);
92 	const bool fd_mode = mcp251xfd_is_fd_mode(priv);
93 	const struct ethtool_ringparam ring = {
94 		.rx_pending = priv->rx_obj_num,
95 		.tx_pending = priv->tx->obj_num,
96 	};
97 	struct can_ram_layout layout;
98 
99 	can_ram_get_layout(&layout, &mcp251xfd_ram_config, &ring, ec, fd_mode);
100 
101 	if ((layout.rx_coalesce != priv->rx_obj_num_coalesce_irq ||
102 	     ec->rx_coalesce_usecs_irq != priv->rx_coalesce_usecs_irq ||
103 	     layout.tx_coalesce != priv->tx_obj_num_coalesce_irq ||
104 	     ec->tx_coalesce_usecs_irq != priv->tx_coalesce_usecs_irq) &&
105 	    netif_running(ndev))
106 		return -EBUSY;
107 
108 	priv->rx_obj_num = layout.cur_rx;
109 	priv->rx_obj_num_coalesce_irq = layout.rx_coalesce;
110 	priv->rx_coalesce_usecs_irq = ec->rx_coalesce_usecs_irq;
111 
112 	priv->tx->obj_num = layout.cur_tx;
113 	priv->tx_obj_num_coalesce_irq = layout.tx_coalesce;
114 	priv->tx_coalesce_usecs_irq = ec->tx_coalesce_usecs_irq;
115 
116 	return 0;
117 }
118 
119 static const struct ethtool_ops mcp251xfd_ethtool_ops = {
120 	.supported_coalesce_params = ETHTOOL_COALESCE_RX_USECS_IRQ |
121 		ETHTOOL_COALESCE_RX_MAX_FRAMES_IRQ |
122 		ETHTOOL_COALESCE_TX_USECS_IRQ |
123 		ETHTOOL_COALESCE_TX_MAX_FRAMES_IRQ,
124 	.get_ringparam = mcp251xfd_ring_get_ringparam,
125 	.set_ringparam = mcp251xfd_ring_set_ringparam,
126 	.get_coalesce = mcp251xfd_ring_get_coalesce,
127 	.set_coalesce = mcp251xfd_ring_set_coalesce,
128 	.get_ts_info = can_ethtool_op_get_ts_info_hwts,
129 };
130 
mcp251xfd_ethtool_init(struct mcp251xfd_priv * priv)131 void mcp251xfd_ethtool_init(struct mcp251xfd_priv *priv)
132 {
133 	struct can_ram_layout layout;
134 
135 	priv->ndev->ethtool_ops = &mcp251xfd_ethtool_ops;
136 
137 	can_ram_get_layout(&layout, &mcp251xfd_ram_config, NULL, NULL, false);
138 	priv->rx_obj_num = layout.default_rx;
139 	priv->tx->obj_num = layout.default_tx;
140 
141 	priv->rx_obj_num_coalesce_irq = 0;
142 	priv->tx_obj_num_coalesce_irq = 0;
143 	priv->rx_coalesce_usecs_irq = 0;
144 	priv->tx_coalesce_usecs_irq = 0;
145 }
146