1 // SPDX-License-Identifier: GPL-2.0-only OR BSD-3-Clause
2 
3 /* Gigabit Ethernet driver for Mellanox BlueField SoC
4  *
5  * Copyright (C) 2020-2021 NVIDIA CORPORATION & AFFILIATES
6  */
7 
8 #include <linux/acpi.h>
9 #include <linux/device.h>
10 #include <linux/dma-mapping.h>
11 #include <linux/etherdevice.h>
12 #include <linux/interrupt.h>
13 #include <linux/iopoll.h>
14 #include <linux/module.h>
15 #include <linux/phy.h>
16 #include <linux/platform_device.h>
17 #include <linux/skbuff.h>
18 
19 #include "mlxbf_gige.h"
20 #include "mlxbf_gige_regs.h"
21 
22 #define DRV_NAME    "mlxbf_gige"
23 
24 /* Allocate SKB whose payload pointer aligns with the Bluefield
25  * hardware DMA limitation, i.e. DMA operation can't cross
26  * a 4KB boundary.  A maximum packet size of 2KB is assumed in the
27  * alignment formula.  The alignment logic overallocates an SKB,
28  * and then adjusts the headroom so that the SKB data pointer is
29  * naturally aligned to a 2KB boundary.
30  */
31 struct sk_buff *mlxbf_gige_alloc_skb(struct mlxbf_gige *priv,
32 				     unsigned int map_len,
33 				     dma_addr_t *buf_dma,
34 				     enum dma_data_direction dir)
35 {
36 	struct sk_buff *skb;
37 	u64 addr, offset;
38 
39 	/* Overallocate the SKB so that any headroom adjustment (to
40 	 * provide 2KB natural alignment) does not exceed payload area
41 	 */
42 	skb = netdev_alloc_skb(priv->netdev, MLXBF_GIGE_DEFAULT_BUF_SZ * 2);
43 	if (!skb)
44 		return NULL;
45 
46 	/* Adjust the headroom so that skb->data is naturally aligned to
47 	 * a 2KB boundary, which is the maximum packet size supported.
48 	 */
49 	addr = (long)skb->data;
50 	offset = (addr + MLXBF_GIGE_DEFAULT_BUF_SZ - 1) &
51 		~(MLXBF_GIGE_DEFAULT_BUF_SZ - 1);
52 	offset -= addr;
53 	if (offset)
54 		skb_reserve(skb, offset);
55 
56 	/* Return streaming DMA mapping to caller */
57 	*buf_dma = dma_map_single(priv->dev, skb->data, map_len, dir);
58 	if (dma_mapping_error(priv->dev, *buf_dma)) {
59 		dev_kfree_skb(skb);
60 		*buf_dma = (dma_addr_t)0;
61 		return NULL;
62 	}
63 
64 	return skb;
65 }
66 
67 static void mlxbf_gige_initial_mac(struct mlxbf_gige *priv)
68 {
69 	u8 mac[ETH_ALEN];
70 	u64 local_mac;
71 
72 	memset(mac, 0, ETH_ALEN);
73 	mlxbf_gige_get_mac_rx_filter(priv, MLXBF_GIGE_LOCAL_MAC_FILTER_IDX,
74 				     &local_mac);
75 	u64_to_ether_addr(local_mac, mac);
76 
77 	if (is_valid_ether_addr(mac)) {
78 		ether_addr_copy(priv->netdev->dev_addr, mac);
79 	} else {
80 		/* Provide a random MAC if for some reason the device has
81 		 * not been configured with a valid MAC address already.
82 		 */
83 		eth_hw_addr_random(priv->netdev);
84 	}
85 
86 	local_mac = ether_addr_to_u64(priv->netdev->dev_addr);
87 	mlxbf_gige_set_mac_rx_filter(priv, MLXBF_GIGE_LOCAL_MAC_FILTER_IDX,
88 				     local_mac);
89 }
90 
91 static void mlxbf_gige_cache_stats(struct mlxbf_gige *priv)
92 {
93 	struct mlxbf_gige_stats *p;
94 
95 	/* Cache stats that will be cleared by clean port operation */
96 	p = &priv->stats;
97 	p->rx_din_dropped_pkts += readq(priv->base +
98 					MLXBF_GIGE_RX_DIN_DROP_COUNTER);
99 	p->rx_filter_passed_pkts += readq(priv->base +
100 					  MLXBF_GIGE_RX_PASS_COUNTER_ALL);
101 	p->rx_filter_discard_pkts += readq(priv->base +
102 					   MLXBF_GIGE_RX_DISC_COUNTER_ALL);
103 }
104 
105 static int mlxbf_gige_clean_port(struct mlxbf_gige *priv)
106 {
107 	u64 control;
108 	u64 temp;
109 	int err;
110 
111 	/* Set the CLEAN_PORT_EN bit to trigger SW reset */
112 	control = readq(priv->base + MLXBF_GIGE_CONTROL);
113 	control |= MLXBF_GIGE_CONTROL_CLEAN_PORT_EN;
114 	writeq(control, priv->base + MLXBF_GIGE_CONTROL);
115 
116 	/* Ensure completion of "clean port" write before polling status */
117 	mb();
118 
119 	err = readq_poll_timeout_atomic(priv->base + MLXBF_GIGE_STATUS, temp,
120 					(temp & MLXBF_GIGE_STATUS_READY),
121 					100, 100000);
122 
123 	/* Clear the CLEAN_PORT_EN bit at end of this loop */
124 	control = readq(priv->base + MLXBF_GIGE_CONTROL);
125 	control &= ~MLXBF_GIGE_CONTROL_CLEAN_PORT_EN;
126 	writeq(control, priv->base + MLXBF_GIGE_CONTROL);
127 
128 	return err;
129 }
130 
131 static int mlxbf_gige_open(struct net_device *netdev)
132 {
133 	struct mlxbf_gige *priv = netdev_priv(netdev);
134 	struct phy_device *phydev = netdev->phydev;
135 	u64 int_en;
136 	int err;
137 
138 	err = mlxbf_gige_request_irqs(priv);
139 	if (err)
140 		return err;
141 	mlxbf_gige_cache_stats(priv);
142 	err = mlxbf_gige_clean_port(priv);
143 	if (err)
144 		goto free_irqs;
145 	err = mlxbf_gige_rx_init(priv);
146 	if (err)
147 		goto free_irqs;
148 	err = mlxbf_gige_tx_init(priv);
149 	if (err)
150 		goto rx_deinit;
151 
152 	phy_start(phydev);
153 
154 	netif_napi_add(netdev, &priv->napi, mlxbf_gige_poll, NAPI_POLL_WEIGHT);
155 	napi_enable(&priv->napi);
156 	netif_start_queue(netdev);
157 
158 	/* Set bits in INT_EN that we care about */
159 	int_en = MLXBF_GIGE_INT_EN_HW_ACCESS_ERROR |
160 		 MLXBF_GIGE_INT_EN_TX_CHECKSUM_INPUTS |
161 		 MLXBF_GIGE_INT_EN_TX_SMALL_FRAME_SIZE |
162 		 MLXBF_GIGE_INT_EN_TX_PI_CI_EXCEED_WQ_SIZE |
163 		 MLXBF_GIGE_INT_EN_SW_CONFIG_ERROR |
164 		 MLXBF_GIGE_INT_EN_SW_ACCESS_ERROR |
165 		 MLXBF_GIGE_INT_EN_RX_RECEIVE_PACKET;
166 
167 	/* Ensure completion of all initialization before enabling interrupts */
168 	mb();
169 
170 	writeq(int_en, priv->base + MLXBF_GIGE_INT_EN);
171 
172 	return 0;
173 
174 rx_deinit:
175 	mlxbf_gige_rx_deinit(priv);
176 
177 free_irqs:
178 	mlxbf_gige_free_irqs(priv);
179 	return err;
180 }
181 
182 static int mlxbf_gige_stop(struct net_device *netdev)
183 {
184 	struct mlxbf_gige *priv = netdev_priv(netdev);
185 
186 	writeq(0, priv->base + MLXBF_GIGE_INT_EN);
187 	netif_stop_queue(netdev);
188 	napi_disable(&priv->napi);
189 	netif_napi_del(&priv->napi);
190 	mlxbf_gige_free_irqs(priv);
191 
192 	phy_stop(netdev->phydev);
193 
194 	mlxbf_gige_rx_deinit(priv);
195 	mlxbf_gige_tx_deinit(priv);
196 	mlxbf_gige_cache_stats(priv);
197 	mlxbf_gige_clean_port(priv);
198 
199 	return 0;
200 }
201 
202 static int mlxbf_gige_eth_ioctl(struct net_device *netdev,
203 			       struct ifreq *ifr, int cmd)
204 {
205 	if (!(netif_running(netdev)))
206 		return -EINVAL;
207 
208 	return phy_mii_ioctl(netdev->phydev, ifr, cmd);
209 }
210 
211 static void mlxbf_gige_set_rx_mode(struct net_device *netdev)
212 {
213 	struct mlxbf_gige *priv = netdev_priv(netdev);
214 	bool new_promisc_enabled;
215 
216 	new_promisc_enabled = netdev->flags & IFF_PROMISC;
217 
218 	/* Only write to the hardware registers if the new setting
219 	 * of promiscuous mode is different from the current one.
220 	 */
221 	if (new_promisc_enabled != priv->promisc_enabled) {
222 		priv->promisc_enabled = new_promisc_enabled;
223 
224 		if (new_promisc_enabled)
225 			mlxbf_gige_enable_promisc(priv);
226 		else
227 			mlxbf_gige_disable_promisc(priv);
228 	}
229 }
230 
231 static void mlxbf_gige_get_stats64(struct net_device *netdev,
232 				   struct rtnl_link_stats64 *stats)
233 {
234 	struct mlxbf_gige *priv = netdev_priv(netdev);
235 
236 	netdev_stats_to_stats64(stats, &netdev->stats);
237 
238 	stats->rx_length_errors = priv->stats.rx_truncate_errors;
239 	stats->rx_fifo_errors = priv->stats.rx_din_dropped_pkts +
240 				readq(priv->base + MLXBF_GIGE_RX_DIN_DROP_COUNTER);
241 	stats->rx_crc_errors = priv->stats.rx_mac_errors;
242 	stats->rx_errors = stats->rx_length_errors +
243 			   stats->rx_fifo_errors +
244 			   stats->rx_crc_errors;
245 
246 	stats->tx_fifo_errors = priv->stats.tx_fifo_full;
247 	stats->tx_errors = stats->tx_fifo_errors;
248 }
249 
250 static const struct net_device_ops mlxbf_gige_netdev_ops = {
251 	.ndo_open		= mlxbf_gige_open,
252 	.ndo_stop		= mlxbf_gige_stop,
253 	.ndo_start_xmit		= mlxbf_gige_start_xmit,
254 	.ndo_set_mac_address	= eth_mac_addr,
255 	.ndo_validate_addr	= eth_validate_addr,
256 	.ndo_eth_ioctl		= mlxbf_gige_eth_ioctl,
257 	.ndo_set_rx_mode        = mlxbf_gige_set_rx_mode,
258 	.ndo_get_stats64        = mlxbf_gige_get_stats64,
259 };
260 
261 static void mlxbf_gige_adjust_link(struct net_device *netdev)
262 {
263 	struct phy_device *phydev = netdev->phydev;
264 
265 	phy_print_status(phydev);
266 }
267 
268 static int mlxbf_gige_probe(struct platform_device *pdev)
269 {
270 	struct phy_device *phydev;
271 	struct net_device *netdev;
272 	struct mlxbf_gige *priv;
273 	void __iomem *llu_base;
274 	void __iomem *plu_base;
275 	void __iomem *base;
276 	u64 control;
277 	int addr;
278 	int err;
279 
280 	base = devm_platform_ioremap_resource(pdev, MLXBF_GIGE_RES_MAC);
281 	if (IS_ERR(base))
282 		return PTR_ERR(base);
283 
284 	llu_base = devm_platform_ioremap_resource(pdev, MLXBF_GIGE_RES_LLU);
285 	if (IS_ERR(llu_base))
286 		return PTR_ERR(llu_base);
287 
288 	plu_base = devm_platform_ioremap_resource(pdev, MLXBF_GIGE_RES_PLU);
289 	if (IS_ERR(plu_base))
290 		return PTR_ERR(plu_base);
291 
292 	/* Perform general init of GigE block */
293 	control = readq(base + MLXBF_GIGE_CONTROL);
294 	control |= MLXBF_GIGE_CONTROL_PORT_EN;
295 	writeq(control, base + MLXBF_GIGE_CONTROL);
296 
297 	netdev = devm_alloc_etherdev(&pdev->dev, sizeof(*priv));
298 	if (!netdev)
299 		return -ENOMEM;
300 
301 	SET_NETDEV_DEV(netdev, &pdev->dev);
302 	netdev->netdev_ops = &mlxbf_gige_netdev_ops;
303 	netdev->ethtool_ops = &mlxbf_gige_ethtool_ops;
304 	priv = netdev_priv(netdev);
305 	priv->netdev = netdev;
306 
307 	platform_set_drvdata(pdev, priv);
308 	priv->dev = &pdev->dev;
309 	priv->pdev = pdev;
310 
311 	spin_lock_init(&priv->lock);
312 	spin_lock_init(&priv->gpio_lock);
313 
314 	/* Attach MDIO device */
315 	err = mlxbf_gige_mdio_probe(pdev, priv);
316 	if (err)
317 		return err;
318 
319 	err = mlxbf_gige_gpio_init(pdev, priv);
320 	if (err) {
321 		dev_err(&pdev->dev, "PHY IRQ initialization failed\n");
322 		mlxbf_gige_mdio_remove(priv);
323 		return -ENODEV;
324 	}
325 
326 	priv->base = base;
327 	priv->llu_base = llu_base;
328 	priv->plu_base = plu_base;
329 
330 	priv->rx_q_entries = MLXBF_GIGE_DEFAULT_RXQ_SZ;
331 	priv->tx_q_entries = MLXBF_GIGE_DEFAULT_TXQ_SZ;
332 
333 	/* Write initial MAC address to hardware */
334 	mlxbf_gige_initial_mac(priv);
335 
336 	err = dma_set_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(64));
337 	if (err) {
338 		dev_err(&pdev->dev, "DMA configuration failed: 0x%x\n", err);
339 		goto out;
340 	}
341 
342 	priv->error_irq = platform_get_irq(pdev, MLXBF_GIGE_ERROR_INTR_IDX);
343 	priv->rx_irq = platform_get_irq(pdev, MLXBF_GIGE_RECEIVE_PKT_INTR_IDX);
344 	priv->llu_plu_irq = platform_get_irq(pdev, MLXBF_GIGE_LLU_PLU_INTR_IDX);
345 
346 	phydev = phy_find_first(priv->mdiobus);
347 	if (!phydev) {
348 		err = -ENODEV;
349 		goto out;
350 	}
351 
352 	addr = phydev->mdio.addr;
353 	priv->mdiobus->irq[addr] = priv->phy_irq;
354 	phydev->irq = priv->phy_irq;
355 
356 	err = phy_connect_direct(netdev, phydev,
357 				 mlxbf_gige_adjust_link,
358 				 PHY_INTERFACE_MODE_GMII);
359 	if (err) {
360 		dev_err(&pdev->dev, "Could not attach to PHY\n");
361 		goto out;
362 	}
363 
364 	/* MAC only supports 1000T full duplex mode */
365 	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_1000baseT_Half_BIT);
366 	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_100baseT_Full_BIT);
367 	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_100baseT_Half_BIT);
368 	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_10baseT_Full_BIT);
369 	phy_remove_link_mode(phydev, ETHTOOL_LINK_MODE_10baseT_Half_BIT);
370 
371 	/* Only symmetric pause with flow control enabled is supported so no
372 	 * need to negotiate pause.
373 	 */
374 	linkmode_clear_bit(ETHTOOL_LINK_MODE_Pause_BIT, phydev->advertising);
375 	linkmode_clear_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, phydev->advertising);
376 
377 	/* Display information about attached PHY device */
378 	phy_attached_info(phydev);
379 
380 	err = register_netdev(netdev);
381 	if (err) {
382 		dev_err(&pdev->dev, "Failed to register netdev\n");
383 		phy_disconnect(phydev);
384 		goto out;
385 	}
386 
387 	return 0;
388 
389 out:
390 	mlxbf_gige_gpio_free(priv);
391 	mlxbf_gige_mdio_remove(priv);
392 	return err;
393 }
394 
395 static int mlxbf_gige_remove(struct platform_device *pdev)
396 {
397 	struct mlxbf_gige *priv = platform_get_drvdata(pdev);
398 
399 	unregister_netdev(priv->netdev);
400 	phy_disconnect(priv->netdev->phydev);
401 	mlxbf_gige_gpio_free(priv);
402 	mlxbf_gige_mdio_remove(priv);
403 	platform_set_drvdata(pdev, NULL);
404 
405 	return 0;
406 }
407 
408 static void mlxbf_gige_shutdown(struct platform_device *pdev)
409 {
410 	struct mlxbf_gige *priv = platform_get_drvdata(pdev);
411 
412 	writeq(0, priv->base + MLXBF_GIGE_INT_EN);
413 	mlxbf_gige_clean_port(priv);
414 }
415 
416 static const struct acpi_device_id __maybe_unused mlxbf_gige_acpi_match[] = {
417 	{ "MLNXBF17", 0 },
418 	{},
419 };
420 MODULE_DEVICE_TABLE(acpi, mlxbf_gige_acpi_match);
421 
422 static struct platform_driver mlxbf_gige_driver = {
423 	.probe = mlxbf_gige_probe,
424 	.remove = mlxbf_gige_remove,
425 	.shutdown = mlxbf_gige_shutdown,
426 	.driver = {
427 		.name = DRV_NAME,
428 		.acpi_match_table = ACPI_PTR(mlxbf_gige_acpi_match),
429 	},
430 };
431 
432 module_platform_driver(mlxbf_gige_driver);
433 
434 MODULE_DESCRIPTION("Mellanox BlueField SoC Gigabit Ethernet Driver");
435 MODULE_AUTHOR("David Thompson <davthompson@nvidia.com>");
436 MODULE_AUTHOR("Asmaa Mnebhi <asmaa@nvidia.com>");
437 MODULE_LICENSE("Dual BSD/GPL");
438