cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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nps_enet.c (18971B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * Copyright(c) 2015 EZchip Technologies.
      4 */
      5
      6#include <linux/module.h>
      7#include <linux/etherdevice.h>
      8#include <linux/interrupt.h>
      9#include <linux/of_address.h>
     10#include <linux/of_irq.h>
     11#include <linux/of_net.h>
     12#include <linux/of_platform.h>
     13#include "nps_enet.h"
     14
     15#define DRV_NAME			"nps_mgt_enet"
     16
     17static inline bool nps_enet_is_tx_pending(struct nps_enet_priv *priv)
     18{
     19	u32 tx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
     20	u32 tx_ctrl_ct = (tx_ctrl_value & TX_CTL_CT_MASK) >> TX_CTL_CT_SHIFT;
     21
     22	return (!tx_ctrl_ct && priv->tx_skb);
     23}
     24
     25static void nps_enet_clean_rx_fifo(struct net_device *ndev, u32 frame_len)
     26{
     27	struct nps_enet_priv *priv = netdev_priv(ndev);
     28	u32 i, len = DIV_ROUND_UP(frame_len, sizeof(u32));
     29
     30	/* Empty Rx FIFO buffer by reading all words */
     31	for (i = 0; i < len; i++)
     32		nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
     33}
     34
     35static void nps_enet_read_rx_fifo(struct net_device *ndev,
     36				  unsigned char *dst, u32 length)
     37{
     38	struct nps_enet_priv *priv = netdev_priv(ndev);
     39	s32 i, last = length & (sizeof(u32) - 1);
     40	u32 *reg = (u32 *)dst, len = length / sizeof(u32);
     41	bool dst_is_aligned = IS_ALIGNED((unsigned long)dst, sizeof(u32));
     42
     43	/* In case dst is not aligned we need an intermediate buffer */
     44	if (dst_is_aligned) {
     45		ioread32_rep(priv->regs_base + NPS_ENET_REG_RX_BUF, reg, len);
     46		reg += len;
     47	} else { /* !dst_is_aligned */
     48		for (i = 0; i < len; i++, reg++) {
     49			u32 buf = nps_enet_reg_get(priv, NPS_ENET_REG_RX_BUF);
     50
     51			put_unaligned_be32(buf, reg);
     52		}
     53	}
     54	/* copy last bytes (if any) */
     55	if (last) {
     56		u32 buf;
     57
     58		ioread32_rep(priv->regs_base + NPS_ENET_REG_RX_BUF, &buf, 1);
     59		memcpy((u8 *)reg, &buf, last);
     60	}
     61}
     62
     63static u32 nps_enet_rx_handler(struct net_device *ndev)
     64{
     65	u32 frame_len, err = 0;
     66	u32 work_done = 0;
     67	struct nps_enet_priv *priv = netdev_priv(ndev);
     68	struct sk_buff *skb;
     69	u32 rx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
     70	u32 rx_ctrl_cr = (rx_ctrl_value & RX_CTL_CR_MASK) >> RX_CTL_CR_SHIFT;
     71	u32 rx_ctrl_er = (rx_ctrl_value & RX_CTL_ER_MASK) >> RX_CTL_ER_SHIFT;
     72	u32 rx_ctrl_crc = (rx_ctrl_value & RX_CTL_CRC_MASK) >> RX_CTL_CRC_SHIFT;
     73
     74	frame_len = (rx_ctrl_value & RX_CTL_NR_MASK) >> RX_CTL_NR_SHIFT;
     75
     76	/* Check if we got RX */
     77	if (!rx_ctrl_cr)
     78		return work_done;
     79
     80	/* If we got here there is a work for us */
     81	work_done++;
     82
     83	/* Check Rx error */
     84	if (rx_ctrl_er) {
     85		ndev->stats.rx_errors++;
     86		err = 1;
     87	}
     88
     89	/* Check Rx CRC error */
     90	if (rx_ctrl_crc) {
     91		ndev->stats.rx_crc_errors++;
     92		ndev->stats.rx_dropped++;
     93		err = 1;
     94	}
     95
     96	/* Check Frame length Min 64b */
     97	if (unlikely(frame_len < ETH_ZLEN)) {
     98		ndev->stats.rx_length_errors++;
     99		ndev->stats.rx_dropped++;
    100		err = 1;
    101	}
    102
    103	if (err)
    104		goto rx_irq_clean;
    105
    106	/* Skb allocation */
    107	skb = netdev_alloc_skb_ip_align(ndev, frame_len);
    108	if (unlikely(!skb)) {
    109		ndev->stats.rx_errors++;
    110		ndev->stats.rx_dropped++;
    111		goto rx_irq_clean;
    112	}
    113
    114	/* Copy frame from Rx fifo into the skb */
    115	nps_enet_read_rx_fifo(ndev, skb->data, frame_len);
    116
    117	skb_put(skb, frame_len);
    118	skb->protocol = eth_type_trans(skb, ndev);
    119	skb->ip_summed = CHECKSUM_UNNECESSARY;
    120
    121	ndev->stats.rx_packets++;
    122	ndev->stats.rx_bytes += frame_len;
    123	netif_receive_skb(skb);
    124
    125	goto rx_irq_frame_done;
    126
    127rx_irq_clean:
    128	/* Clean Rx fifo */
    129	nps_enet_clean_rx_fifo(ndev, frame_len);
    130
    131rx_irq_frame_done:
    132	/* Ack Rx ctrl register */
    133	nps_enet_reg_set(priv, NPS_ENET_REG_RX_CTL, 0);
    134
    135	return work_done;
    136}
    137
    138static void nps_enet_tx_handler(struct net_device *ndev)
    139{
    140	struct nps_enet_priv *priv = netdev_priv(ndev);
    141	u32 tx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_TX_CTL);
    142	u32 tx_ctrl_et = (tx_ctrl_value & TX_CTL_ET_MASK) >> TX_CTL_ET_SHIFT;
    143	u32 tx_ctrl_nt = (tx_ctrl_value & TX_CTL_NT_MASK) >> TX_CTL_NT_SHIFT;
    144
    145	/* Check if we got TX */
    146	if (!nps_enet_is_tx_pending(priv))
    147		return;
    148
    149	/* Ack Tx ctrl register */
    150	nps_enet_reg_set(priv, NPS_ENET_REG_TX_CTL, 0);
    151
    152	/* Check Tx transmit error */
    153	if (unlikely(tx_ctrl_et)) {
    154		ndev->stats.tx_errors++;
    155	} else {
    156		ndev->stats.tx_packets++;
    157		ndev->stats.tx_bytes += tx_ctrl_nt;
    158	}
    159
    160	dev_kfree_skb(priv->tx_skb);
    161	priv->tx_skb = NULL;
    162
    163	if (netif_queue_stopped(ndev))
    164		netif_wake_queue(ndev);
    165}
    166
    167/**
    168 * nps_enet_poll - NAPI poll handler.
    169 * @napi:       Pointer to napi_struct structure.
    170 * @budget:     How many frames to process on one call.
    171 *
    172 * returns:     Number of processed frames
    173 */
    174static int nps_enet_poll(struct napi_struct *napi, int budget)
    175{
    176	struct net_device *ndev = napi->dev;
    177	struct nps_enet_priv *priv = netdev_priv(ndev);
    178	u32 work_done;
    179
    180	nps_enet_tx_handler(ndev);
    181	work_done = nps_enet_rx_handler(ndev);
    182	if ((work_done < budget) && napi_complete_done(napi, work_done)) {
    183		u32 buf_int_enable_value = 0;
    184
    185		/* set tx_done and rx_rdy bits */
    186		buf_int_enable_value |= NPS_ENET_ENABLE << RX_RDY_SHIFT;
    187		buf_int_enable_value |= NPS_ENET_ENABLE << TX_DONE_SHIFT;
    188
    189		nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
    190				 buf_int_enable_value);
    191
    192		/* in case we will get a tx interrupt while interrupts
    193		 * are masked, we will lose it since the tx is edge interrupt.
    194		 * specifically, while executing the code section above,
    195		 * between nps_enet_tx_handler and the interrupts enable, all
    196		 * tx requests will be stuck until we will get an rx interrupt.
    197		 * the two code lines below will solve this situation by
    198		 * re-adding ourselves to the poll list.
    199		 */
    200		if (nps_enet_is_tx_pending(priv)) {
    201			nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
    202			napi_reschedule(napi);
    203		}
    204	}
    205
    206	return work_done;
    207}
    208
    209/**
    210 * nps_enet_irq_handler - Global interrupt handler for ENET.
    211 * @irq:                irq number.
    212 * @dev_instance:       device instance.
    213 *
    214 * returns: IRQ_HANDLED for all cases.
    215 *
    216 * EZchip ENET has 2 interrupt causes, and depending on bits raised in
    217 * CTRL registers we may tell what is a reason for interrupt to fire up.
    218 * We got one for RX and the other for TX (completion).
    219 */
    220static irqreturn_t nps_enet_irq_handler(s32 irq, void *dev_instance)
    221{
    222	struct net_device *ndev = dev_instance;
    223	struct nps_enet_priv *priv = netdev_priv(ndev);
    224	u32 rx_ctrl_value = nps_enet_reg_get(priv, NPS_ENET_REG_RX_CTL);
    225	u32 rx_ctrl_cr = (rx_ctrl_value & RX_CTL_CR_MASK) >> RX_CTL_CR_SHIFT;
    226
    227	if (nps_enet_is_tx_pending(priv) || rx_ctrl_cr)
    228		if (likely(napi_schedule_prep(&priv->napi))) {
    229			nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
    230			__napi_schedule(&priv->napi);
    231		}
    232
    233	return IRQ_HANDLED;
    234}
    235
    236static void nps_enet_set_hw_mac_address(struct net_device *ndev)
    237{
    238	struct nps_enet_priv *priv = netdev_priv(ndev);
    239	u32 ge_mac_cfg_1_value = 0;
    240	u32 *ge_mac_cfg_2_value = &priv->ge_mac_cfg_2_value;
    241
    242	/* set MAC address in HW */
    243	ge_mac_cfg_1_value |= ndev->dev_addr[0] << CFG_1_OCTET_0_SHIFT;
    244	ge_mac_cfg_1_value |= ndev->dev_addr[1] << CFG_1_OCTET_1_SHIFT;
    245	ge_mac_cfg_1_value |= ndev->dev_addr[2] << CFG_1_OCTET_2_SHIFT;
    246	ge_mac_cfg_1_value |= ndev->dev_addr[3] << CFG_1_OCTET_3_SHIFT;
    247	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_OCTET_4_MASK)
    248		 | ndev->dev_addr[4] << CFG_2_OCTET_4_SHIFT;
    249	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_OCTET_5_MASK)
    250		 | ndev->dev_addr[5] << CFG_2_OCTET_5_SHIFT;
    251
    252	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_1,
    253			 ge_mac_cfg_1_value);
    254
    255	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2,
    256			 *ge_mac_cfg_2_value);
    257}
    258
    259/**
    260 * nps_enet_hw_reset - Reset the network device.
    261 * @ndev:       Pointer to the network device.
    262 *
    263 * This function reset the PCS and TX fifo.
    264 * The programming model is to set the relevant reset bits
    265 * wait for some time for this to propagate and then unset
    266 * the reset bits. This way we ensure that reset procedure
    267 * is done successfully by device.
    268 */
    269static void nps_enet_hw_reset(struct net_device *ndev)
    270{
    271	struct nps_enet_priv *priv = netdev_priv(ndev);
    272	u32 ge_rst_value = 0, phase_fifo_ctl_value = 0;
    273
    274	/* Pcs reset sequence*/
    275	ge_rst_value |= NPS_ENET_ENABLE << RST_GMAC_0_SHIFT;
    276	nps_enet_reg_set(priv, NPS_ENET_REG_GE_RST, ge_rst_value);
    277	usleep_range(10, 20);
    278	ge_rst_value = 0;
    279	nps_enet_reg_set(priv, NPS_ENET_REG_GE_RST, ge_rst_value);
    280
    281	/* Tx fifo reset sequence */
    282	phase_fifo_ctl_value |= NPS_ENET_ENABLE << PHASE_FIFO_CTL_RST_SHIFT;
    283	phase_fifo_ctl_value |= NPS_ENET_ENABLE << PHASE_FIFO_CTL_INIT_SHIFT;
    284	nps_enet_reg_set(priv, NPS_ENET_REG_PHASE_FIFO_CTL,
    285			 phase_fifo_ctl_value);
    286	usleep_range(10, 20);
    287	phase_fifo_ctl_value = 0;
    288	nps_enet_reg_set(priv, NPS_ENET_REG_PHASE_FIFO_CTL,
    289			 phase_fifo_ctl_value);
    290}
    291
    292static void nps_enet_hw_enable_control(struct net_device *ndev)
    293{
    294	struct nps_enet_priv *priv = netdev_priv(ndev);
    295	u32 ge_mac_cfg_0_value = 0, buf_int_enable_value = 0;
    296	u32 *ge_mac_cfg_2_value = &priv->ge_mac_cfg_2_value;
    297	u32 *ge_mac_cfg_3_value = &priv->ge_mac_cfg_3_value;
    298	s32 max_frame_length;
    299
    300	/* Enable Rx and Tx statistics */
    301	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_STAT_EN_MASK)
    302		 | NPS_ENET_GE_MAC_CFG_2_STAT_EN << CFG_2_STAT_EN_SHIFT;
    303
    304	/* Discard packets with different MAC address */
    305	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_DISK_DA_MASK)
    306		 | NPS_ENET_ENABLE << CFG_2_DISK_DA_SHIFT;
    307
    308	/* Discard multicast packets */
    309	*ge_mac_cfg_2_value = (*ge_mac_cfg_2_value & ~CFG_2_DISK_MC_MASK)
    310		 | NPS_ENET_ENABLE << CFG_2_DISK_MC_SHIFT;
    311
    312	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2,
    313			 *ge_mac_cfg_2_value);
    314
    315	/* Discard Packets bigger than max frame length */
    316	max_frame_length = ETH_HLEN + ndev->mtu + ETH_FCS_LEN;
    317	if (max_frame_length <= NPS_ENET_MAX_FRAME_LENGTH) {
    318		*ge_mac_cfg_3_value =
    319			 (*ge_mac_cfg_3_value & ~CFG_3_MAX_LEN_MASK)
    320			 | max_frame_length << CFG_3_MAX_LEN_SHIFT;
    321	}
    322
    323	/* Enable interrupts */
    324	buf_int_enable_value |= NPS_ENET_ENABLE << RX_RDY_SHIFT;
    325	buf_int_enable_value |= NPS_ENET_ENABLE << TX_DONE_SHIFT;
    326	nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE,
    327			 buf_int_enable_value);
    328
    329	/* Write device MAC address to HW */
    330	nps_enet_set_hw_mac_address(ndev);
    331
    332	/* Rx and Tx HW features */
    333	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_PAD_EN_SHIFT;
    334	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_CRC_EN_SHIFT;
    335	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_CRC_STRIP_SHIFT;
    336
    337	/* IFG configuration */
    338	ge_mac_cfg_0_value |=
    339		 NPS_ENET_GE_MAC_CFG_0_RX_IFG << CFG_0_RX_IFG_SHIFT;
    340	ge_mac_cfg_0_value |=
    341		 NPS_ENET_GE_MAC_CFG_0_TX_IFG << CFG_0_TX_IFG_SHIFT;
    342
    343	/* preamble configuration */
    344	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_PR_CHECK_EN_SHIFT;
    345	ge_mac_cfg_0_value |=
    346		 NPS_ENET_GE_MAC_CFG_0_TX_PR_LEN << CFG_0_TX_PR_LEN_SHIFT;
    347
    348	/* enable flow control frames */
    349	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_FC_EN_SHIFT;
    350	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_FC_EN_SHIFT;
    351	ge_mac_cfg_0_value |=
    352		 NPS_ENET_GE_MAC_CFG_0_TX_FC_RETR << CFG_0_TX_FC_RETR_SHIFT;
    353	*ge_mac_cfg_3_value = (*ge_mac_cfg_3_value & ~CFG_3_CF_DROP_MASK)
    354		 | NPS_ENET_ENABLE << CFG_3_CF_DROP_SHIFT;
    355
    356	/* Enable Rx and Tx */
    357	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_RX_EN_SHIFT;
    358	ge_mac_cfg_0_value |= NPS_ENET_ENABLE << CFG_0_TX_EN_SHIFT;
    359
    360	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_3,
    361			 *ge_mac_cfg_3_value);
    362	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_0,
    363			 ge_mac_cfg_0_value);
    364}
    365
    366static void nps_enet_hw_disable_control(struct net_device *ndev)
    367{
    368	struct nps_enet_priv *priv = netdev_priv(ndev);
    369
    370	/* Disable interrupts */
    371	nps_enet_reg_set(priv, NPS_ENET_REG_BUF_INT_ENABLE, 0);
    372
    373	/* Disable Rx and Tx */
    374	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_0, 0);
    375}
    376
    377static void nps_enet_send_frame(struct net_device *ndev,
    378				struct sk_buff *skb)
    379{
    380	struct nps_enet_priv *priv = netdev_priv(ndev);
    381	u32 tx_ctrl_value = 0;
    382	short length = skb->len;
    383	u32 i, len = DIV_ROUND_UP(length, sizeof(u32));
    384	u32 *src = (void *)skb->data;
    385	bool src_is_aligned = IS_ALIGNED((unsigned long)src, sizeof(u32));
    386
    387	/* In case src is not aligned we need an intermediate buffer */
    388	if (src_is_aligned)
    389		iowrite32_rep(priv->regs_base + NPS_ENET_REG_TX_BUF, src, len);
    390	else /* !src_is_aligned */
    391		for (i = 0; i < len; i++, src++)
    392			nps_enet_reg_set(priv, NPS_ENET_REG_TX_BUF,
    393					 get_unaligned_be32(src));
    394
    395	/* Write the length of the Frame */
    396	tx_ctrl_value |= length << TX_CTL_NT_SHIFT;
    397
    398	tx_ctrl_value |= NPS_ENET_ENABLE << TX_CTL_CT_SHIFT;
    399	/* Send Frame */
    400	nps_enet_reg_set(priv, NPS_ENET_REG_TX_CTL, tx_ctrl_value);
    401}
    402
    403/**
    404 * nps_enet_set_mac_address - Set the MAC address for this device.
    405 * @ndev:       Pointer to net_device structure.
    406 * @p:          6 byte Address to be written as MAC address.
    407 *
    408 * This function copies the HW address from the sockaddr structure to the
    409 * net_device structure and updates the address in HW.
    410 *
    411 * returns:     -EBUSY if the net device is busy or 0 if the address is set
    412 *              successfully.
    413 */
    414static s32 nps_enet_set_mac_address(struct net_device *ndev, void *p)
    415{
    416	struct sockaddr *addr = p;
    417	s32 res;
    418
    419	if (netif_running(ndev))
    420		return -EBUSY;
    421
    422	res = eth_mac_addr(ndev, p);
    423	if (!res) {
    424		eth_hw_addr_set(ndev, addr->sa_data);
    425		nps_enet_set_hw_mac_address(ndev);
    426	}
    427
    428	return res;
    429}
    430
    431/**
    432 * nps_enet_set_rx_mode - Change the receive filtering mode.
    433 * @ndev:       Pointer to the network device.
    434 *
    435 * This function enables/disables promiscuous mode
    436 */
    437static void nps_enet_set_rx_mode(struct net_device *ndev)
    438{
    439	struct nps_enet_priv *priv = netdev_priv(ndev);
    440	u32 ge_mac_cfg_2_value = priv->ge_mac_cfg_2_value;
    441
    442	if (ndev->flags & IFF_PROMISC) {
    443		ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_DA_MASK)
    444			 | NPS_ENET_DISABLE << CFG_2_DISK_DA_SHIFT;
    445		ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_MC_MASK)
    446			 | NPS_ENET_DISABLE << CFG_2_DISK_MC_SHIFT;
    447
    448	} else {
    449		ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_DA_MASK)
    450			 | NPS_ENET_ENABLE << CFG_2_DISK_DA_SHIFT;
    451		ge_mac_cfg_2_value = (ge_mac_cfg_2_value & ~CFG_2_DISK_MC_MASK)
    452			 | NPS_ENET_ENABLE << CFG_2_DISK_MC_SHIFT;
    453	}
    454
    455	nps_enet_reg_set(priv, NPS_ENET_REG_GE_MAC_CFG_2, ge_mac_cfg_2_value);
    456}
    457
    458/**
    459 * nps_enet_open - Open the network device.
    460 * @ndev:       Pointer to the network device.
    461 *
    462 * returns: 0, on success or non-zero error value on failure.
    463 *
    464 * This function sets the MAC address, requests and enables an IRQ
    465 * for the ENET device and starts the Tx queue.
    466 */
    467static s32 nps_enet_open(struct net_device *ndev)
    468{
    469	struct nps_enet_priv *priv = netdev_priv(ndev);
    470	s32 err;
    471
    472	/* Reset private variables */
    473	priv->tx_skb = NULL;
    474	priv->ge_mac_cfg_2_value = 0;
    475	priv->ge_mac_cfg_3_value = 0;
    476
    477	/* ge_mac_cfg_3 default values */
    478	priv->ge_mac_cfg_3_value |=
    479		 NPS_ENET_GE_MAC_CFG_3_RX_IFG_TH << CFG_3_RX_IFG_TH_SHIFT;
    480
    481	priv->ge_mac_cfg_3_value |=
    482		 NPS_ENET_GE_MAC_CFG_3_MAX_LEN << CFG_3_MAX_LEN_SHIFT;
    483
    484	/* Disable HW device */
    485	nps_enet_hw_disable_control(ndev);
    486
    487	/* irq Rx allocation */
    488	err = request_irq(priv->irq, nps_enet_irq_handler,
    489			  0, "enet-rx-tx", ndev);
    490	if (err)
    491		return err;
    492
    493	napi_enable(&priv->napi);
    494
    495	/* Enable HW device */
    496	nps_enet_hw_reset(ndev);
    497	nps_enet_hw_enable_control(ndev);
    498
    499	netif_start_queue(ndev);
    500
    501	return 0;
    502}
    503
    504/**
    505 * nps_enet_stop - Close the network device.
    506 * @ndev:       Pointer to the network device.
    507 *
    508 * This function stops the Tx queue, disables interrupts for the ENET device.
    509 */
    510static s32 nps_enet_stop(struct net_device *ndev)
    511{
    512	struct nps_enet_priv *priv = netdev_priv(ndev);
    513
    514	napi_disable(&priv->napi);
    515	netif_stop_queue(ndev);
    516	nps_enet_hw_disable_control(ndev);
    517	free_irq(priv->irq, ndev);
    518
    519	return 0;
    520}
    521
    522/**
    523 * nps_enet_start_xmit - Starts the data transmission.
    524 * @skb:        sk_buff pointer that contains data to be Transmitted.
    525 * @ndev:       Pointer to net_device structure.
    526 *
    527 * returns: NETDEV_TX_OK, on success
    528 *              NETDEV_TX_BUSY, if any of the descriptors are not free.
    529 *
    530 * This function is invoked from upper layers to initiate transmission.
    531 */
    532static netdev_tx_t nps_enet_start_xmit(struct sk_buff *skb,
    533				       struct net_device *ndev)
    534{
    535	struct nps_enet_priv *priv = netdev_priv(ndev);
    536
    537	/* This driver handles one frame at a time  */
    538	netif_stop_queue(ndev);
    539
    540	priv->tx_skb = skb;
    541
    542	/* make sure tx_skb is actually written to the memory
    543	 * before the HW is informed and the IRQ is fired.
    544	 */
    545	wmb();
    546
    547	nps_enet_send_frame(ndev, skb);
    548
    549	return NETDEV_TX_OK;
    550}
    551
    552#ifdef CONFIG_NET_POLL_CONTROLLER
    553static void nps_enet_poll_controller(struct net_device *ndev)
    554{
    555	disable_irq(ndev->irq);
    556	nps_enet_irq_handler(ndev->irq, ndev);
    557	enable_irq(ndev->irq);
    558}
    559#endif
    560
    561static const struct net_device_ops nps_netdev_ops = {
    562	.ndo_open		= nps_enet_open,
    563	.ndo_stop		= nps_enet_stop,
    564	.ndo_start_xmit		= nps_enet_start_xmit,
    565	.ndo_set_mac_address	= nps_enet_set_mac_address,
    566	.ndo_set_rx_mode        = nps_enet_set_rx_mode,
    567#ifdef CONFIG_NET_POLL_CONTROLLER
    568	.ndo_poll_controller	= nps_enet_poll_controller,
    569#endif
    570};
    571
    572static s32 nps_enet_probe(struct platform_device *pdev)
    573{
    574	struct device *dev = &pdev->dev;
    575	struct net_device *ndev;
    576	struct nps_enet_priv *priv;
    577	s32 err = 0;
    578
    579	if (!dev->of_node)
    580		return -ENODEV;
    581
    582	ndev = alloc_etherdev(sizeof(struct nps_enet_priv));
    583	if (!ndev)
    584		return -ENOMEM;
    585
    586	platform_set_drvdata(pdev, ndev);
    587	SET_NETDEV_DEV(ndev, dev);
    588	priv = netdev_priv(ndev);
    589
    590	/* The EZ NET specific entries in the device structure. */
    591	ndev->netdev_ops = &nps_netdev_ops;
    592	ndev->watchdog_timeo = (400 * HZ / 1000);
    593	/* FIXME :: no multicast support yet */
    594	ndev->flags &= ~IFF_MULTICAST;
    595
    596	priv->regs_base = devm_platform_ioremap_resource(pdev, 0);
    597	if (IS_ERR(priv->regs_base)) {
    598		err = PTR_ERR(priv->regs_base);
    599		goto out_netdev;
    600	}
    601	dev_dbg(dev, "Registers base address is 0x%p\n", priv->regs_base);
    602
    603	/* set kernel MAC address to dev */
    604	err = of_get_ethdev_address(dev->of_node, ndev);
    605	if (err)
    606		eth_hw_addr_random(ndev);
    607
    608	/* Get IRQ number */
    609	priv->irq = platform_get_irq(pdev, 0);
    610	if (priv->irq < 0) {
    611		err = -ENODEV;
    612		goto out_netdev;
    613	}
    614
    615	netif_napi_add_weight(ndev, &priv->napi, nps_enet_poll,
    616			      NPS_ENET_NAPI_POLL_WEIGHT);
    617
    618	/* Register the driver. Should be the last thing in probe */
    619	err = register_netdev(ndev);
    620	if (err) {
    621		dev_err(dev, "Failed to register ndev for %s, err = 0x%08x\n",
    622			ndev->name, (s32)err);
    623		goto out_netif_api;
    624	}
    625
    626	dev_info(dev, "(rx/tx=%d)\n", priv->irq);
    627	return 0;
    628
    629out_netif_api:
    630	netif_napi_del(&priv->napi);
    631out_netdev:
    632	free_netdev(ndev);
    633
    634	return err;
    635}
    636
    637static s32 nps_enet_remove(struct platform_device *pdev)
    638{
    639	struct net_device *ndev = platform_get_drvdata(pdev);
    640	struct nps_enet_priv *priv = netdev_priv(ndev);
    641
    642	unregister_netdev(ndev);
    643	netif_napi_del(&priv->napi);
    644	free_netdev(ndev);
    645
    646	return 0;
    647}
    648
    649static const struct of_device_id nps_enet_dt_ids[] = {
    650	{ .compatible = "ezchip,nps-mgt-enet" },
    651	{ /* Sentinel */ }
    652};
    653MODULE_DEVICE_TABLE(of, nps_enet_dt_ids);
    654
    655static struct platform_driver nps_enet_driver = {
    656	.probe = nps_enet_probe,
    657	.remove = nps_enet_remove,
    658	.driver = {
    659		.name = DRV_NAME,
    660		.of_match_table  = nps_enet_dt_ids,
    661	},
    662};
    663
    664module_platform_driver(nps_enet_driver);
    665
    666MODULE_AUTHOR("EZchip Semiconductor");
    667MODULE_LICENSE("GPL v2");