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Jetpack/kernel/nvidia/drivers/net/tegra_hv_net.c

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/*
* tegra_hv_net.c: ethernet emulation over Tegra HV
*
* Very loosely based on virtio_net.c
*
* Copyright (C) 2014-2018, NVIDIA CORPORATION. All rights reserved.
*
* This file is licensed under the terms of the GNU General Public License
* version 2. This program is licensed "as is" without any warranty of any
* kind, whether express or implied.
*/
#undef DEBUG
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/netdevice.h>
#include <linux/of.h>
#include <linux/of_net.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/serial.h>
#include <linux/serial_core.h>
#include <linux/platform_device.h>
#include <linux/io.h>
#include <soc/tegra/chip-id.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/if.h>
#include <linux/slab.h>
#include <linux/version.h>
#define DRV_NAME "tegra_hv_net"
#define DRV_VERSION "0.1"
#include <linux/tegra-ivc.h>
#include <soc/tegra/virt/syscalls.h>
/* frame format is
* 0000: <flags>
* 0004: data
*
* data frame
* 0000: [16-bit frame size][13-bit pad][Last-bit][First-bit][F_CNTRL=0]
* 0004: [packet-size 32 bit]
* 0008: data
*
* control frame
* 0000: <flags> (F_CNTRL == 1) F_CNTRL_CMD(x)
* 0004: control frame data (deduced from F_CNTRL_CMD)
*/
/* data header size */
#define HDR_SIZE 8
#define F_CNTRL (1 << 0) /* control frame (0 = data frame) */
#define F_CNTRL_CMD(x) ((u32)((x) & 0xff) << 24) /* control frame command */
#define F_CNTRL_CMD_STATUS F_CNTRL_CMD(0) /* link status cmd */
#define F_STATUS_UP (1 << 1) /* link status is up */
#define F_STATUS_PAUSE (1 << 2) /* link status is pause */
#define F_STATUS_PENDING (1 << 23) /* pending link status update */
#define F_DATA_FIRST (1 << 1) /* first chunk of a frame */
#define F_DATA_LAST (1 << 2) /* last chunk of a frame */
#define F_DATA_FSIZE_SHIFT 16
#define F_DATA_FSIZE_MASK (~0 << F_DATA_FSIZE_SHIFT)
#define F_DATA_FSIZE(x) (((u32)(x) << F_DATA_FSIZE_SHIFT) & F_DATA_FSIZE_MASK)
/* jumbo frame limit */
#define MAX_MTU 9000
#define DEFAULT_HIGH_WATERMARK_MULT 50
#define DEFAULT_LOW_WATERMARK_MULT 25
#define DEFAULT_MAX_TX_DELAY_MSECS 10
enum drop_kind {
dk_none,
/* tx */
dk_linearize,
dk_full,
dk_wq,
dk_write,
/* rx */
dk_frame,
dk_packet,
dk_unexpected,
dk_alloc,
dk_overflow,
};
struct tegra_hv_net_stats {
struct u64_stats_sync tx_syncp;
struct u64_stats_sync rx_syncp;
u64 tx_bytes;
u64 tx_packets;
u64 tx_drops;
u64 rx_bytes;
u64 rx_packets;
u64 rx_drops;
/* internal tx stats */
u64 tx_linearize_fail;
u64 tx_queue_full;
u64 tx_wq_fail;
u64 tx_ivc_write_fail;
/* internal rx stats */
u64 rx_bad_frame;
u64 rx_bad_packet;
u64 rx_unexpected_packet;
u64 rx_alloc_fail;
u64 rx_overflow;
};
struct tegra_hv_net {
struct platform_device *pdev;
struct net_device *ndev;
struct tegra_hv_ivc_cookie *ivck;
const void *mac_address;
struct napi_struct napi;
struct tegra_hv_net_stats __percpu *stats;
struct sk_buff *rx_skb;
struct sk_buff_head tx_q;
struct work_struct xmit_work;
struct workqueue_struct *xmit_wq;
wait_queue_head_t wq;
unsigned int high_watermark; /* mult * framesize */
unsigned int low_watermark;
unsigned int max_tx_delay;
};
static int tegra_hv_net_open(struct net_device *ndev)
{
struct tegra_hv_net *hvn = netdev_priv(ndev);
napi_enable(&hvn->napi);
netif_start_queue(ndev);
/*
* check if there are already packets in our queue,
* and if so, we need to schedule a call to handle them
*/
if (tegra_hv_ivc_can_read(hvn->ivck))
napi_schedule(&hvn->napi);
return 0;
}
static irqreturn_t tegra_hv_net_interrupt(int irq, void *data)
{
struct net_device *ndev = data;
struct tegra_hv_net *hvn = netdev_priv(ndev);
/* until this function returns 0, the channel is unusable */
if (tegra_hv_ivc_channel_notified(hvn->ivck) != 0)
return IRQ_HANDLED;
if (tegra_hv_ivc_can_write(hvn->ivck))
wake_up_interruptible_all(&hvn->wq);
if (tegra_hv_ivc_can_read(hvn->ivck))
napi_schedule(&hvn->napi);
return IRQ_HANDLED;
}
static void *tegra_hv_net_xmit_get_buffer(struct tegra_hv_net *hvn)
{
void *p;
int ret;
/*
* grabbing a frame can fail for the following reasons:
* 1. the channel is full / peer is uncooperative
* 2. the channel is under reset / peer has restarted
*/
p = tegra_hv_ivc_write_get_next_frame(hvn->ivck);
if (IS_ERR(p)) {
ret = wait_event_interruptible_timeout(hvn->wq,
!IS_ERR(p = tegra_hv_ivc_write_get_next_frame(
hvn->ivck)),
msecs_to_jiffies(hvn->max_tx_delay));
if (ret <= 0) {
net_warn_ratelimited(
"%s: timed out after %u ms\n",
hvn->ndev->name,
hvn->max_tx_delay);
}
}
return p;
}
static void tegra_hv_net_xmit_work(struct work_struct *work)
{
struct tegra_hv_net *hvn =
container_of(work, struct tegra_hv_net, xmit_work);
struct tegra_hv_net_stats *stats = raw_cpu_ptr(hvn->stats);
struct net_device *ndev = hvn->ndev;
struct sk_buff *skb;
int ret, max_frame, count, first, last, orig_len;
u32 *p, p0, p1;
enum drop_kind dk;
max_frame = hvn->ivck->frame_size - HDR_SIZE;
dk = dk_none;
while ((skb = skb_dequeue(&hvn->tx_q)) != NULL) {
/* start the queue if it is short again */
if (netif_queue_stopped(ndev) &&
skb_queue_len(&hvn->tx_q) < hvn->low_watermark)
netif_start_queue(ndev);
ret = skb_linearize(skb);
if (ret != 0) {
netdev_err(hvn->ndev,
"%s: skb_linearize error=%d\n",
__func__, ret);
dk = dk_linearize;
goto drop;
}
/* print_hex_dump(KERN_INFO, "tx-", DUMP_PREFIX_OFFSET,
* 16, 1, skb->data, skb->len, true); */
/* copy the fragments */
orig_len = skb->len;
first = 1;
while (skb->len > 0) {
count = skb->len;
if (count > max_frame)
count = max_frame;
/* wait up to the maximum send timeout */
p = tegra_hv_net_xmit_get_buffer(hvn);
if (IS_ERR(p)) {
dk = dk_wq;
goto drop;
}
last = skb->len == count;
p0 = F_DATA_FSIZE(count);
if (first)
p0 |= F_DATA_FIRST;
if (last)
p0 |= F_DATA_LAST;
p1 = orig_len;
netdev_dbg(ndev, "F: %c%c F%d P%d [%08x %08x]\n",
first ? 'F' : '.',
last ? 'L' : '.',
count, orig_len, p[0], p[1]);
first = 0;
p[0] = p0;
p[1] = p1;
skb_copy_from_linear_data(skb, &p[2], count);
/* advance the tx queue */
(void)tegra_hv_ivc_write_advance(hvn->ivck);
skb_pull(skb, count);
}
/* all OK */
dk = dk_none;
drop:
dev_kfree_skb(skb);
u64_stats_update_begin(&stats->tx_syncp);
if (dk == dk_none) {
stats->tx_packets++;
stats->tx_bytes += orig_len;
} else {
stats->tx_drops++;
switch (dk) {
default:
/* never happens but gcc sometimes whines */
break;
case dk_linearize:
stats->tx_linearize_fail++;
break;
case dk_full:
stats->tx_queue_full++;
break;
case dk_wq:
stats->tx_wq_fail++;
break;
case dk_write:
stats->tx_ivc_write_fail++;
break;
}
}
u64_stats_update_end(&stats->tx_syncp);
}
}
/* xmit is dummy, we just add the skb to the tx_q and queue work */
static netdev_tx_t tegra_hv_net_xmit(struct sk_buff *skb,
struct net_device *ndev)
{
struct tegra_hv_net *hvn = netdev_priv(ndev);
skb_orphan(skb);
nf_reset(skb);
skb_queue_tail(&hvn->tx_q, skb);
queue_work_on(WORK_CPU_UNBOUND, hvn->xmit_wq, &hvn->xmit_work);
/* stop the queue if it gets too long */
if (!netif_queue_stopped(ndev) &&
skb_queue_len(&hvn->tx_q) >= hvn->high_watermark)
netif_stop_queue(ndev);
else if (netif_queue_stopped(ndev) &&
skb_queue_len(&hvn->tx_q) < hvn->low_watermark)
netif_start_queue(ndev);
return NETDEV_TX_OK;
}
static int
tegra_hv_net_stop(struct net_device *ndev)
{
struct tegra_hv_net *hvn = netdev_priv(ndev);
netif_stop_queue(ndev);
napi_disable(&hvn->napi);
return 0;
}
static int tegra_hv_net_change_mtu(struct net_device *ndev, int new_mtu)
{
if (new_mtu < 14 || new_mtu > MAX_MTU) {
netdev_err(ndev, "invalid MTU, max MTU is: %d\n", MAX_MTU);
return -EINVAL;
}
if (ndev->mtu == new_mtu)
return 0;
/* we can really handle any MTU size */
return 0;
}
static void tegra_hv_net_set_rx_mode(struct net_device *ndev)
{
/* we don't do any kind of filtering */
}
static void tegra_hv_net_tx_timeout(struct net_device *ndev)
{
netdev_err(ndev, "%s\n", __func__);
}
#if LINUX_VERSION_CODE >= KERNEL_VERSION(4,14,0)
void
#else
static struct rtnl_link_stats64 *
#endif
tegra_hv_net_get_stats64(struct net_device *ndev,
struct rtnl_link_stats64 *tot)
{
struct tegra_hv_net *hvn = netdev_priv(ndev);
struct tegra_hv_net_stats *stats;
u64 tx_packets, tx_bytes, tx_drops, rx_packets, rx_bytes, rx_drops;
unsigned int start;
int cpu;
for_each_possible_cpu(cpu) {
stats = per_cpu_ptr(hvn->stats, cpu);
do {
start = u64_stats_fetch_begin_irq(&stats->tx_syncp);
tx_packets = stats->tx_packets;
tx_bytes = stats->tx_bytes;
tx_drops = stats->tx_drops;
} while (u64_stats_fetch_retry_irq(&stats->tx_syncp, start));
do {
start = u64_stats_fetch_begin_irq(&stats->rx_syncp);
rx_packets = stats->rx_packets;
rx_bytes = stats->rx_bytes;
rx_drops = stats->rx_drops;
} while (u64_stats_fetch_retry_irq(&stats->rx_syncp, start));
tot->tx_packets += tx_packets;
tot->tx_bytes += tx_bytes;
tot->tx_dropped += tx_drops;
tot->rx_packets += rx_packets;
tot->rx_bytes += rx_bytes;
tot->rx_dropped += rx_drops;
}
#if LINUX_VERSION_CODE < KERNEL_VERSION(4,14,0)
return tot;
#endif
}
static int tegra_hv_net_set_mac_address(struct net_device *dev, void *p)
{
return 0;
}
static const struct net_device_ops tegra_hv_netdev_ops = {
.ndo_open = tegra_hv_net_open,
.ndo_start_xmit = tegra_hv_net_xmit,
.ndo_stop = tegra_hv_net_stop,
.ndo_change_mtu = tegra_hv_net_change_mtu,
.ndo_set_rx_mode = tegra_hv_net_set_rx_mode,
.ndo_tx_timeout = tegra_hv_net_tx_timeout,
.ndo_get_stats64 = tegra_hv_net_get_stats64,
.ndo_set_mac_address = tegra_hv_net_set_mac_address,
};
static void tegra_hv_net_ethtool_get_drvinfo(struct net_device *ndev,
struct ethtool_drvinfo *info)
{
struct tegra_hv_net *hvn = netdev_priv(ndev);
strlcpy(info->driver, DRV_NAME, sizeof(info->driver));
strlcpy(info->version, DRV_VERSION, sizeof(info->version));
strlcpy(info->bus_info, dev_name(&hvn->pdev->dev),
sizeof(info->bus_info));
}
static const struct ethtool_ops tegra_hv_ethtool_ops = {
.get_drvinfo = tegra_hv_net_ethtool_get_drvinfo,
.get_link = ethtool_op_get_link,
};
static void tegra_hv_net_tx_complete(struct tegra_hv_net *hvn)
{
struct net_device *ndev = hvn->ndev;
/* wake queue if no more tx buffers */
if (skb_queue_len(&hvn->tx_q) == 0)
netif_wake_queue(ndev);
}
static int tegra_hv_net_rx(struct tegra_hv_net *hvn, int limit)
{
struct tegra_hv_net_stats *stats = this_cpu_ptr(hvn->stats);
struct net_device *ndev = hvn->ndev;
struct sk_buff *skb;
int nr, frame_size, max_frame, count, first, last;
u32 *p, p0;
enum drop_kind dk;
max_frame = hvn->ivck->frame_size - HDR_SIZE;
nr = 0;
dk = dk_none;
while (nr < limit) {
/*
* grabbing a frame can fail for the following reasons:
* 1. the channel is empty / peer is uncooperative
* 2. the channel is under reset / peer has restarted
*/
p = tegra_hv_ivc_read_get_next_frame(hvn->ivck);
if (IS_ERR(p))
break;
nr++;
p0 = p[0];
first = !!(p0 & F_DATA_FIRST);
last = !!(p0 & F_DATA_LAST);
frame_size = (p0 & F_DATA_FSIZE_MASK) >> F_DATA_FSIZE_SHIFT;
count = p[1];
netdev_dbg(ndev, "F: %c%c F%d P%d [%08x %08x]\n",
first ? 'F' : '.',
last ? 'L' : '.',
frame_size, count, p[0], p[1]);
if (frame_size > max_frame) {
netdev_err(ndev, "Bad fragment size %d\n", frame_size);
dk = dk_frame;
goto drop;
}
/* verify that packet is sane */
if (count < 14 || count > MAX_MTU) {
netdev_err(ndev, "Bad packet size %d\n", count);
dk = dk_packet;
goto drop;
}
/* receive state machine */
if (hvn->rx_skb == NULL) {
if (!first) {
netdev_err(ndev, "unexpected fragment\n");
dk = dk_unexpected;
goto drop;
}
hvn->rx_skb = netdev_alloc_skb(ndev, count);
if (hvn->rx_skb == NULL) {
netdev_err(ndev, "failed to allocate packet\n");
dk = dk_alloc;
goto drop;
}
}
/* verify that skb still can receive the data */
if (skb_tailroom(hvn->rx_skb) < frame_size) {
netdev_err(ndev, "skb overflow\n");
dev_kfree_skb(hvn->rx_skb);
hvn->rx_skb = NULL;
dk = dk_overflow;
goto drop;
}
/* append the data */
skb = hvn->rx_skb;
skb_copy_to_linear_data_offset(skb, skb->len, p + 2,
frame_size);
skb_put(skb, frame_size);
if (last) {
/* print_hex_dump(KERN_INFO, "rx-", DUMP_PREFIX_OFFSET,
* 16, 1, skb->data, skb->len, true); */
count = skb->len;
skb->protocol = eth_type_trans(skb, ndev);
skb->ip_summed = CHECKSUM_NONE;
netif_receive_skb(skb);
hvn->rx_skb = NULL;
}
dk = dk_none;
drop:
(void)tegra_hv_ivc_read_advance(hvn->ivck);
u64_stats_update_begin(&stats->rx_syncp);
if (dk == dk_none) {
if (last) {
stats->rx_packets++;
stats->rx_bytes += count;
}
} else {
stats->rx_drops++;
switch (dk) {
default:
/* never happens but gcc sometimes whines */
break;
case dk_frame:
stats->rx_bad_frame++;
break;
case dk_packet:
stats->rx_bad_packet++;
break;
case dk_unexpected:
stats->rx_unexpected_packet++;
break;
case dk_alloc:
stats->rx_alloc_fail++;
break;
case dk_overflow:
stats->rx_overflow++;
break;
}
}
u64_stats_update_end(&stats->rx_syncp);
}
return nr;
}
static int tegra_hv_net_poll(struct napi_struct *napi, int budget)
{
struct tegra_hv_net *hvn =
container_of(napi, struct tegra_hv_net, napi);
int work_done = 0;
tegra_hv_net_tx_complete(hvn);
work_done = tegra_hv_net_rx(hvn, budget);
if (work_done < budget) {
napi_complete(napi);
/*
* if an interrupt occurs after tegra_hv_net_rx() but before
* napi_complete(), we lose the call to napi_schedule().
*/
if (tegra_hv_ivc_can_read(hvn->ivck))
napi_reschedule(napi);
}
return work_done;
}
static int tegra_hv_net_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *dn, *hv_dn;
struct net_device *ndev = NULL;
struct tegra_hv_net *hvn = NULL;
int ret;
u32 id;
u32 highmark, lowmark, txdelay;
if (!is_tegra_hypervisor_mode()) {
dev_info(dev, "Hypervisor is not present\n");
return -ENODEV;
}
dn = dev->of_node;
if (dn == NULL) {
dev_err(dev, "No OF data\n");
return -EINVAL;
}
hv_dn = of_parse_phandle(dn, "ivc", 0);
if (hv_dn == NULL) {
dev_err(dev, "Failed to parse phandle of ivc prop\n");
return -EINVAL;
}
ret = of_property_read_u32_index(dn, "ivc", 1, &id);
if (ret != 0) {
dev_err(dev, "Failed to read IVC property ID\n");
goto out_of_put;
}
ret = of_property_read_u32(dn, "high-watermark-mult", &highmark);
if (ret != 0)
highmark = DEFAULT_HIGH_WATERMARK_MULT;
ret = of_property_read_u32(dn, "low-watermark-mult", &lowmark);
if (ret != 0)
lowmark = DEFAULT_LOW_WATERMARK_MULT;
if (highmark <= lowmark) {
dev_err(dev, "Bad watermark configuration (high <= low = %u < %u)\n",
highmark, lowmark);
goto out_of_put;
}
ret = of_property_read_u32(dn, "max-tx-delay-msecs", &txdelay);
if (ret != 0)
txdelay = DEFAULT_MAX_TX_DELAY_MSECS;
ndev = alloc_netdev(sizeof(*hvn), "hv%d", NET_NAME_UNKNOWN,
ether_setup);
if (ndev == NULL) {
dev_err(dev, "Failed to allocate netdev\n");
ret = -ENOMEM;
goto out_of_put;
}
hvn = netdev_priv(ndev);
hvn->stats = alloc_percpu(struct tegra_hv_net_stats);
if (hvn->stats == NULL) {
dev_err(dev, "Failed to allocate per-cpu stats\n");
ret = -ENOMEM;
goto out_free_ndev;
}
hvn->ivck = tegra_hv_ivc_reserve(hv_dn, id, NULL);
of_node_put(hv_dn);
hv_dn = NULL;
if (IS_ERR_OR_NULL(hvn->ivck)) {
dev_err(dev, "Failed to reserve IVC channel %d\n", id);
ret = PTR_ERR(hvn->ivck);
hvn->ivck = NULL;
goto out_free_stats;
}
hvn->high_watermark = highmark * hvn->ivck->nframes;
hvn->low_watermark = lowmark * hvn->ivck->nframes;
hvn->max_tx_delay = txdelay;
/* make sure the frame size is sufficient */
if (hvn->ivck->frame_size <= HDR_SIZE + 4) {
dev_err(dev, "frame size too small to support COMM\n");
ret = -EINVAL;
goto out_unreserve;
}
dev_info(dev, "Reserved IVC channel #%d - frame_size=%d\n",
id, hvn->ivck->frame_size);
SET_NETDEV_DEV(ndev, dev);
platform_set_drvdata(pdev, ndev);
ether_setup(ndev);
ndev->netdev_ops = &tegra_hv_netdev_ops;
ndev->ethtool_ops = &tegra_hv_ethtool_ops;
skb_queue_head_init(&hvn->tx_q);
INIT_WORK(&hvn->xmit_work, tegra_hv_net_xmit_work);
hvn->pdev = pdev;
hvn->ndev = ndev;
ndev->irq = hvn->ivck->irq;
init_waitqueue_head(&hvn->wq);
ndev->priv_flags |= IFF_UNICAST_FLT | IFF_LIVE_ADDR_CHANGE;
ndev->hw_features = 0; /* we're a really dumb device for now */
ndev->features |= ndev->hw_features;
/* get mac address from the DT */
hvn->mac_address = of_get_mac_address(dev->of_node);
if (hvn->mac_address == NULL) {
if (of_property_read_bool(dev->of_node, "use-random-mac-addr"))
eth_hw_addr_random(ndev);
else {
unsigned int gid;
dev_warn(dev, "No valid mac-address found, using fixed local address\n");
ndev->dev_addr[0] = 0x0a;
ndev->dev_addr[1] = 0x86;
ndev->dev_addr[2] = 0x4c;
ndev->dev_addr[3] = 0xf8;
ndev->dev_addr[4] = (uint8_t)id;
ret = hyp_read_gid(&gid);
if (ret != 0) {
dev_err(dev, "Failed to read guest id\n");
goto out_unreserve;
}
ndev->dev_addr[5] = (uint8_t)(gid);
}
} else {
/* Set the MAC address. */
ether_addr_copy(ndev->dev_addr, hvn->mac_address);
}
hvn->xmit_wq = alloc_workqueue("tgvnet-wq-%d",
WQ_UNBOUND | WQ_MEM_RECLAIM,
1, /* FIXME: from DT? */
pdev->id);
if (hvn->xmit_wq == NULL) {
dev_err(dev, "Failed to allocate workqueue\n");
ret = -ENOMEM;
goto out_unreserve;
}
netif_napi_add(ndev, &hvn->napi, tegra_hv_net_poll, 64);
ret = register_netdev(ndev);
if (ret) {
dev_err(dev, "Failed to register netdev\n");
goto out_free_wq;
}
/*
* start the channel reset process asynchronously. until the reset
* process completes, any attempt to use the ivc channel will return
* an error (e.g., all transmits will fail).
*/
tegra_hv_ivc_channel_reset(hvn->ivck);
/* the interrupt request must be the last action */
ret = devm_request_irq(dev, ndev->irq, tegra_hv_net_interrupt, 0,
dev_name(dev), ndev);
if (ret != 0) {
dev_err(dev, "Could not request irq #%d\n", ndev->irq);
goto out_unreg_netdev;
}
dev_info(dev, "ready\n");
return 0;
out_unreg_netdev:
unregister_netdev(ndev);
out_free_wq:
netif_napi_del(&hvn->napi);
destroy_workqueue(hvn->xmit_wq);
out_unreserve:
tegra_hv_ivc_unreserve(hvn->ivck);
out_free_stats:
free_percpu(hvn->stats);
out_free_ndev:
free_netdev(ndev);
out_of_put:
of_node_put(hv_dn);
return ret;
}
static int tegra_hv_net_remove(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct net_device *ndev = platform_get_drvdata(pdev);
struct tegra_hv_net *hvn = netdev_priv(ndev);
platform_set_drvdata(pdev, NULL);
devm_free_irq(dev, ndev->irq, dev);
unregister_netdev(ndev);
netif_napi_del(&hvn->napi);
destroy_workqueue(hvn->xmit_wq);
tegra_hv_ivc_unreserve(hvn->ivck);
free_percpu(hvn->stats);
free_netdev(ndev);
return 0;
}
#ifdef CONFIG_PM
static int tegra_hv_net_suspend(struct platform_device *pdev,
pm_message_t state)
{
struct net_device *ndev = platform_get_drvdata(pdev);
struct tegra_hv_net *hvn = netdev_priv(ndev);
/* If the netdev is not even running, no action */
if (!netif_running(ndev))
return 0;
/* As this device is going to suspend,
* link can't be considered up, although we are not resetting
* the IVC channel. Therefore mark the link detached
* This would stop tx from getting queued as well
*/
netif_device_detach(ndev);
ndev->netdev_ops->ndo_stop(ndev);
/* tegra_hv_net_stop uses netif_stop_queue to disable the queue.
* netif_stop_queue doesn't prevent xmit_transfer running on another
* cpu, so additionally we need netif_tx_disable
*/
netif_tx_disable(ndev);
/* Now no further job should be coming in, but
* there could be one queued or running already.
* Cancel or wait for such a job
*/
cancel_work_sync(&hvn->xmit_work);
/* Workqueue should not be running at this point,
* so disable irq
*/
disable_irq(ndev->irq);
return 0;
}
static int tegra_hv_net_resume(struct platform_device *pdev)
{
struct net_device *ndev = platform_get_drvdata(pdev);
struct tegra_hv_net *hvn = netdev_priv(ndev);
if (!netif_running(ndev))
return 0;
enable_irq(ndev->irq);
ndev->netdev_ops->ndo_open(ndev);
/* Would wake the queue and mark the link enabled */
netif_device_attach(ndev);
/* Start the queue blindly, in case the previous
* work was cancelled during suspend
* If there is no pending xmit,
* the workqueue will wake up then exit gracefully
*/
queue_work_on(WORK_CPU_UNBOUND, hvn->xmit_wq, &hvn->xmit_work);
return 0;
}
#endif
#ifdef CONFIG_OF
static struct of_device_id tegra_hv_net_match[] = {
{ .compatible = "nvidia,tegra-hv-net", },
{},
};
MODULE_DEVICE_TABLE(of, tegra_hv_net_match);
#endif /* CONFIG_OF */
static struct platform_driver tegra_hv_net_driver = {
.probe = tegra_hv_net_probe,
.remove = tegra_hv_net_remove,
#ifdef CONFIG_PM_SLEEP
.suspend = tegra_hv_net_suspend,
.resume = tegra_hv_net_resume,
#endif
.driver = {
.name = DRV_NAME,
.owner = THIS_MODULE,
.of_match_table = of_match_ptr(tegra_hv_net_match),
},
};
module_platform_driver(tegra_hv_net_driver);
MODULE_AUTHOR("Pantelis Antoniou <pantoniou@nvidia.com>");
MODULE_DESCRIPTION("Ethernet network device over Tegra Hypervisor IVC channel");
MODULE_LICENSE("GPL");
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