linux-stable/drivers/net/caif/caif_virtio.c
Johannes Berg 59ae1d127a networking: introduce and use skb_put_data()
A common pattern with skb_put() is to just want to memcpy()
some data into the new space, introduce skb_put_data() for
this.

An spatch similar to the one for skb_put_zero() converts many
of the places using it:

    @@
    identifier p, p2;
    expression len, skb, data;
    type t, t2;
    @@
    (
    -p = skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    |
    -p = (t)skb_put(skb, len);
    +p = skb_put_data(skb, data, len);
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, len);
    |
    -memcpy(p, data, len);
    )

    @@
    type t, t2;
    identifier p, p2;
    expression skb, data;
    @@
    t *p;
    ...
    (
    -p = skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    |
    -p = (t *)skb_put(skb, sizeof(t));
    +p = skb_put_data(skb, data, sizeof(t));
    )
    (
    p2 = (t2)p;
    -memcpy(p2, data, sizeof(*p));
    |
    -memcpy(p, data, sizeof(*p));
    )

    @@
    expression skb, len, data;
    @@
    -memcpy(skb_put(skb, len), data, len);
    +skb_put_data(skb, data, len);

(again, manually post-processed to retain some comments)

Reviewed-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16 11:48:37 -04:00

789 lines
21 KiB
C

/*
* Copyright (C) ST-Ericsson AB 2013
* Authors: Vicram Arv
* Dmitry Tarnyagin <dmitry.tarnyagin@lockless.no>
* Sjur Brendeland
* License terms: GNU General Public License (GPL) version 2
*/
#include <linux/module.h>
#include <linux/if_arp.h>
#include <linux/virtio.h>
#include <linux/vringh.h>
#include <linux/debugfs.h>
#include <linux/spinlock.h>
#include <linux/genalloc.h>
#include <linux/interrupt.h>
#include <linux/netdevice.h>
#include <linux/rtnetlink.h>
#include <linux/virtio_ids.h>
#include <linux/virtio_caif.h>
#include <linux/virtio_ring.h>
#include <linux/dma-mapping.h>
#include <net/caif/caif_dev.h>
#include <linux/virtio_config.h>
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Vicram Arv");
MODULE_AUTHOR("Sjur Brendeland");
MODULE_DESCRIPTION("Virtio CAIF Driver");
/* NAPI schedule quota */
#define CFV_DEFAULT_QUOTA 32
/* Defaults used if virtio config space is unavailable */
#define CFV_DEF_MTU_SIZE 4096
#define CFV_DEF_HEADROOM 32
#define CFV_DEF_TAILROOM 32
/* Required IP header alignment */
#define IP_HDR_ALIGN 4
/* struct cfv_napi_contxt - NAPI context info
* @riov: IOV holding data read from the ring. Note that riov may
* still hold data when cfv_rx_poll() returns.
* @head: Last descriptor ID we received from vringh_getdesc_kern.
* We use this to put descriptor back on the used ring. USHRT_MAX is
* used to indicate invalid head-id.
*/
struct cfv_napi_context {
struct vringh_kiov riov;
unsigned short head;
};
/* struct cfv_stats - statistics for debugfs
* @rx_napi_complete: Number of NAPI completions (RX)
* @rx_napi_resched: Number of calls where the full quota was used (RX)
* @rx_nomem: Number of SKB alloc failures (RX)
* @rx_kicks: Number of RX kicks
* @tx_full_ring: Number times TX ring was full
* @tx_no_mem: Number of times TX went out of memory
* @tx_flow_on: Number of flow on (TX)
* @tx_kicks: Number of TX kicks
*/
struct cfv_stats {
u32 rx_napi_complete;
u32 rx_napi_resched;
u32 rx_nomem;
u32 rx_kicks;
u32 tx_full_ring;
u32 tx_no_mem;
u32 tx_flow_on;
u32 tx_kicks;
};
/* struct cfv_info - Caif Virtio control structure
* @cfdev: caif common header
* @vdev: Associated virtio device
* @vr_rx: rx/downlink host vring
* @vq_tx: tx/uplink virtqueue
* @ndev: CAIF link layer device
* @watermark_tx: indicates number of free descriptors we need
* to reopen the tx-queues after overload.
* @tx_lock: protects vq_tx from concurrent use
* @tx_release_tasklet: Tasklet for freeing consumed TX buffers
* @napi: Napi context used in cfv_rx_poll()
* @ctx: Context data used in cfv_rx_poll()
* @tx_hr: transmit headroom
* @rx_hr: receive headroom
* @tx_tr: transmit tail room
* @rx_tr: receive tail room
* @mtu: transmit max size
* @mru: receive max size
* @allocsz: size of dma memory reserved for TX buffers
* @alloc_addr: virtual address to dma memory for TX buffers
* @alloc_dma: dma address to dma memory for TX buffers
* @genpool: Gen Pool used for allocating TX buffers
* @reserved_mem: Pointer to memory reserve allocated from genpool
* @reserved_size: Size of memory reserve allocated from genpool
* @stats: Statistics exposed in sysfs
* @debugfs: Debugfs dentry for statistic counters
*/
struct cfv_info {
struct caif_dev_common cfdev;
struct virtio_device *vdev;
struct vringh *vr_rx;
struct virtqueue *vq_tx;
struct net_device *ndev;
unsigned int watermark_tx;
/* Protect access to vq_tx */
spinlock_t tx_lock;
struct tasklet_struct tx_release_tasklet;
struct napi_struct napi;
struct cfv_napi_context ctx;
u16 tx_hr;
u16 rx_hr;
u16 tx_tr;
u16 rx_tr;
u32 mtu;
u32 mru;
size_t allocsz;
void *alloc_addr;
dma_addr_t alloc_dma;
struct gen_pool *genpool;
unsigned long reserved_mem;
size_t reserved_size;
struct cfv_stats stats;
struct dentry *debugfs;
};
/* struct buf_info - maintains transmit buffer data handle
* @size: size of transmit buffer
* @dma_handle: handle to allocated dma device memory area
* @vaddr: virtual address mapping to allocated memory area
*/
struct buf_info {
size_t size;
u8 *vaddr;
};
/* Called from virtio device, in IRQ context */
static void cfv_release_cb(struct virtqueue *vq_tx)
{
struct cfv_info *cfv = vq_tx->vdev->priv;
++cfv->stats.tx_kicks;
tasklet_schedule(&cfv->tx_release_tasklet);
}
static void free_buf_info(struct cfv_info *cfv, struct buf_info *buf_info)
{
if (!buf_info)
return;
gen_pool_free(cfv->genpool, (unsigned long) buf_info->vaddr,
buf_info->size);
kfree(buf_info);
}
/* This is invoked whenever the remote processor completed processing
* a TX msg we just sent, and the buffer is put back to the used ring.
*/
static void cfv_release_used_buf(struct virtqueue *vq_tx)
{
struct cfv_info *cfv = vq_tx->vdev->priv;
unsigned long flags;
BUG_ON(vq_tx != cfv->vq_tx);
for (;;) {
unsigned int len;
struct buf_info *buf_info;
/* Get used buffer from used ring to recycle used descriptors */
spin_lock_irqsave(&cfv->tx_lock, flags);
buf_info = virtqueue_get_buf(vq_tx, &len);
spin_unlock_irqrestore(&cfv->tx_lock, flags);
/* Stop looping if there are no more buffers to free */
if (!buf_info)
break;
free_buf_info(cfv, buf_info);
/* watermark_tx indicates if we previously stopped the tx
* queues. If we have enough free stots in the virtio ring,
* re-establish memory reserved and open up tx queues.
*/
if (cfv->vq_tx->num_free <= cfv->watermark_tx)
continue;
/* Re-establish memory reserve */
if (cfv->reserved_mem == 0 && cfv->genpool)
cfv->reserved_mem =
gen_pool_alloc(cfv->genpool,
cfv->reserved_size);
/* Open up the tx queues */
if (cfv->reserved_mem) {
cfv->watermark_tx =
virtqueue_get_vring_size(cfv->vq_tx);
netif_tx_wake_all_queues(cfv->ndev);
/* Buffers are recycled in cfv_netdev_tx, so
* disable notifications when queues are opened.
*/
virtqueue_disable_cb(cfv->vq_tx);
++cfv->stats.tx_flow_on;
} else {
/* if no memory reserve, wait for more free slots */
WARN_ON(cfv->watermark_tx >
virtqueue_get_vring_size(cfv->vq_tx));
cfv->watermark_tx +=
virtqueue_get_vring_size(cfv->vq_tx) / 4;
}
}
}
/* Allocate a SKB and copy packet data to it */
static struct sk_buff *cfv_alloc_and_copy_skb(int *err,
struct cfv_info *cfv,
u8 *frm, u32 frm_len)
{
struct sk_buff *skb;
u32 cfpkt_len, pad_len;
*err = 0;
/* Verify that packet size with down-link header and mtu size */
if (frm_len > cfv->mru || frm_len <= cfv->rx_hr + cfv->rx_tr) {
netdev_err(cfv->ndev,
"Invalid frmlen:%u mtu:%u hr:%d tr:%d\n",
frm_len, cfv->mru, cfv->rx_hr,
cfv->rx_tr);
*err = -EPROTO;
return NULL;
}
cfpkt_len = frm_len - (cfv->rx_hr + cfv->rx_tr);
pad_len = (unsigned long)(frm + cfv->rx_hr) & (IP_HDR_ALIGN - 1);
skb = netdev_alloc_skb(cfv->ndev, frm_len + pad_len);
if (!skb) {
*err = -ENOMEM;
return NULL;
}
skb_reserve(skb, cfv->rx_hr + pad_len);
skb_put_data(skb, frm + cfv->rx_hr, cfpkt_len);
return skb;
}
/* Get packets from the host vring */
static int cfv_rx_poll(struct napi_struct *napi, int quota)
{
struct cfv_info *cfv = container_of(napi, struct cfv_info, napi);
int rxcnt = 0;
int err = 0;
void *buf;
struct sk_buff *skb;
struct vringh_kiov *riov = &cfv->ctx.riov;
unsigned int skb_len;
do {
skb = NULL;
/* Put the previous iovec back on the used ring and
* fetch a new iovec if we have processed all elements.
*/
if (riov->i == riov->used) {
if (cfv->ctx.head != USHRT_MAX) {
vringh_complete_kern(cfv->vr_rx,
cfv->ctx.head,
0);
cfv->ctx.head = USHRT_MAX;
}
err = vringh_getdesc_kern(
cfv->vr_rx,
riov,
NULL,
&cfv->ctx.head,
GFP_ATOMIC);
if (err <= 0)
goto exit;
}
buf = phys_to_virt((unsigned long) riov->iov[riov->i].iov_base);
/* TODO: Add check on valid buffer address */
skb = cfv_alloc_and_copy_skb(&err, cfv, buf,
riov->iov[riov->i].iov_len);
if (unlikely(err))
goto exit;
/* Push received packet up the stack. */
skb_len = skb->len;
skb->protocol = htons(ETH_P_CAIF);
skb_reset_mac_header(skb);
skb->dev = cfv->ndev;
err = netif_receive_skb(skb);
if (unlikely(err)) {
++cfv->ndev->stats.rx_dropped;
} else {
++cfv->ndev->stats.rx_packets;
cfv->ndev->stats.rx_bytes += skb_len;
}
++riov->i;
++rxcnt;
} while (rxcnt < quota);
++cfv->stats.rx_napi_resched;
goto out;
exit:
switch (err) {
case 0:
++cfv->stats.rx_napi_complete;
/* Really out of patckets? (stolen from virtio_net)*/
napi_complete(napi);
if (unlikely(!vringh_notify_enable_kern(cfv->vr_rx)) &&
napi_schedule_prep(napi)) {
vringh_notify_disable_kern(cfv->vr_rx);
__napi_schedule(napi);
}
break;
case -ENOMEM:
++cfv->stats.rx_nomem;
dev_kfree_skb(skb);
/* Stop NAPI poll on OOM, we hope to be polled later */
napi_complete(napi);
vringh_notify_enable_kern(cfv->vr_rx);
break;
default:
/* We're doomed, any modem fault is fatal */
netdev_warn(cfv->ndev, "Bad ring, disable device\n");
cfv->ndev->stats.rx_dropped = riov->used - riov->i;
napi_complete(napi);
vringh_notify_disable_kern(cfv->vr_rx);
netif_carrier_off(cfv->ndev);
break;
}
out:
if (rxcnt && vringh_need_notify_kern(cfv->vr_rx) > 0)
vringh_notify(cfv->vr_rx);
return rxcnt;
}
static void cfv_recv(struct virtio_device *vdev, struct vringh *vr_rx)
{
struct cfv_info *cfv = vdev->priv;
++cfv->stats.rx_kicks;
vringh_notify_disable_kern(cfv->vr_rx);
napi_schedule(&cfv->napi);
}
static void cfv_destroy_genpool(struct cfv_info *cfv)
{
if (cfv->alloc_addr)
dma_free_coherent(cfv->vdev->dev.parent->parent,
cfv->allocsz, cfv->alloc_addr,
cfv->alloc_dma);
if (!cfv->genpool)
return;
gen_pool_free(cfv->genpool, cfv->reserved_mem,
cfv->reserved_size);
gen_pool_destroy(cfv->genpool);
cfv->genpool = NULL;
}
static int cfv_create_genpool(struct cfv_info *cfv)
{
int err;
/* dma_alloc can only allocate whole pages, and we need a more
* fine graned allocation so we use genpool. We ask for space needed
* by IP and a full ring. If the dma allcoation fails we retry with a
* smaller allocation size.
*/
err = -ENOMEM;
cfv->allocsz = (virtqueue_get_vring_size(cfv->vq_tx) *
(ETH_DATA_LEN + cfv->tx_hr + cfv->tx_tr) * 11)/10;
if (cfv->allocsz <= (num_possible_cpus() + 1) * cfv->ndev->mtu)
return -EINVAL;
for (;;) {
if (cfv->allocsz <= num_possible_cpus() * cfv->ndev->mtu) {
netdev_info(cfv->ndev, "Not enough device memory\n");
return -ENOMEM;
}
cfv->alloc_addr = dma_alloc_coherent(
cfv->vdev->dev.parent->parent,
cfv->allocsz, &cfv->alloc_dma,
GFP_ATOMIC);
if (cfv->alloc_addr)
break;
cfv->allocsz = (cfv->allocsz * 3) >> 2;
}
netdev_dbg(cfv->ndev, "Allocated %zd bytes from dma-memory\n",
cfv->allocsz);
/* Allocate on 128 bytes boundaries (1 << 7)*/
cfv->genpool = gen_pool_create(7, -1);
if (!cfv->genpool)
goto err;
err = gen_pool_add_virt(cfv->genpool, (unsigned long)cfv->alloc_addr,
(phys_addr_t)virt_to_phys(cfv->alloc_addr),
cfv->allocsz, -1);
if (err)
goto err;
/* Reserve some memory for low memory situations. If we hit the roof
* in the memory pool, we stop TX flow and release the reserve.
*/
cfv->reserved_size = num_possible_cpus() * cfv->ndev->mtu;
cfv->reserved_mem = gen_pool_alloc(cfv->genpool,
cfv->reserved_size);
if (!cfv->reserved_mem) {
err = -ENOMEM;
goto err;
}
cfv->watermark_tx = virtqueue_get_vring_size(cfv->vq_tx);
return 0;
err:
cfv_destroy_genpool(cfv);
return err;
}
/* Enable the CAIF interface and allocate the memory-pool */
static int cfv_netdev_open(struct net_device *netdev)
{
struct cfv_info *cfv = netdev_priv(netdev);
if (cfv_create_genpool(cfv))
return -ENOMEM;
netif_carrier_on(netdev);
napi_enable(&cfv->napi);
/* Schedule NAPI to read any pending packets */
napi_schedule(&cfv->napi);
return 0;
}
/* Disable the CAIF interface and free the memory-pool */
static int cfv_netdev_close(struct net_device *netdev)
{
struct cfv_info *cfv = netdev_priv(netdev);
unsigned long flags;
struct buf_info *buf_info;
/* Disable interrupts, queues and NAPI polling */
netif_carrier_off(netdev);
virtqueue_disable_cb(cfv->vq_tx);
vringh_notify_disable_kern(cfv->vr_rx);
napi_disable(&cfv->napi);
/* Release any TX buffers on both used and avilable rings */
cfv_release_used_buf(cfv->vq_tx);
spin_lock_irqsave(&cfv->tx_lock, flags);
while ((buf_info = virtqueue_detach_unused_buf(cfv->vq_tx)))
free_buf_info(cfv, buf_info);
spin_unlock_irqrestore(&cfv->tx_lock, flags);
/* Release all dma allocated memory and destroy the pool */
cfv_destroy_genpool(cfv);
return 0;
}
/* Allocate a buffer in dma-memory and copy skb to it */
static struct buf_info *cfv_alloc_and_copy_to_shm(struct cfv_info *cfv,
struct sk_buff *skb,
struct scatterlist *sg)
{
struct caif_payload_info *info = (void *)&skb->cb;
struct buf_info *buf_info = NULL;
u8 pad_len, hdr_ofs;
if (!cfv->genpool)
goto err;
if (unlikely(cfv->tx_hr + skb->len + cfv->tx_tr > cfv->mtu)) {
netdev_warn(cfv->ndev, "Invalid packet len (%d > %d)\n",
cfv->tx_hr + skb->len + cfv->tx_tr, cfv->mtu);
goto err;
}
buf_info = kmalloc(sizeof(struct buf_info), GFP_ATOMIC);
if (unlikely(!buf_info))
goto err;
/* Make the IP header aligned in tbe buffer */
hdr_ofs = cfv->tx_hr + info->hdr_len;
pad_len = hdr_ofs & (IP_HDR_ALIGN - 1);
buf_info->size = cfv->tx_hr + skb->len + cfv->tx_tr + pad_len;
/* allocate dma memory buffer */
buf_info->vaddr = (void *)gen_pool_alloc(cfv->genpool, buf_info->size);
if (unlikely(!buf_info->vaddr))
goto err;
/* copy skbuf contents to send buffer */
skb_copy_bits(skb, 0, buf_info->vaddr + cfv->tx_hr + pad_len, skb->len);
sg_init_one(sg, buf_info->vaddr + pad_len,
skb->len + cfv->tx_hr + cfv->rx_hr);
return buf_info;
err:
kfree(buf_info);
return NULL;
}
/* Put the CAIF packet on the virtio ring and kick the receiver */
static int cfv_netdev_tx(struct sk_buff *skb, struct net_device *netdev)
{
struct cfv_info *cfv = netdev_priv(netdev);
struct buf_info *buf_info;
struct scatterlist sg;
unsigned long flags;
bool flow_off = false;
int ret;
/* garbage collect released buffers */
cfv_release_used_buf(cfv->vq_tx);
spin_lock_irqsave(&cfv->tx_lock, flags);
/* Flow-off check takes into account number of cpus to make sure
* virtqueue will not be overfilled in any possible smp conditions.
*
* Flow-on is triggered when sufficient buffers are freed
*/
if (unlikely(cfv->vq_tx->num_free <= num_present_cpus())) {
flow_off = true;
cfv->stats.tx_full_ring++;
}
/* If we run out of memory, we release the memory reserve and retry
* allocation.
*/
buf_info = cfv_alloc_and_copy_to_shm(cfv, skb, &sg);
if (unlikely(!buf_info)) {
cfv->stats.tx_no_mem++;
flow_off = true;
if (cfv->reserved_mem && cfv->genpool) {
gen_pool_free(cfv->genpool, cfv->reserved_mem,
cfv->reserved_size);
cfv->reserved_mem = 0;
buf_info = cfv_alloc_and_copy_to_shm(cfv, skb, &sg);
}
}
if (unlikely(flow_off)) {
/* Turn flow on when a 1/4 of the descriptors are released */
cfv->watermark_tx = virtqueue_get_vring_size(cfv->vq_tx) / 4;
/* Enable notifications of recycled TX buffers */
virtqueue_enable_cb(cfv->vq_tx);
netif_tx_stop_all_queues(netdev);
}
if (unlikely(!buf_info)) {
/* If the memory reserve does it's job, this shouldn't happen */
netdev_warn(cfv->ndev, "Out of gen_pool memory\n");
goto err;
}
ret = virtqueue_add_outbuf(cfv->vq_tx, &sg, 1, buf_info, GFP_ATOMIC);
if (unlikely((ret < 0))) {
/* If flow control works, this shouldn't happen */
netdev_warn(cfv->ndev, "Failed adding buffer to TX vring:%d\n",
ret);
goto err;
}
/* update netdev statistics */
cfv->ndev->stats.tx_packets++;
cfv->ndev->stats.tx_bytes += skb->len;
spin_unlock_irqrestore(&cfv->tx_lock, flags);
/* tell the remote processor it has a pending message to read */
virtqueue_kick(cfv->vq_tx);
dev_kfree_skb(skb);
return NETDEV_TX_OK;
err:
spin_unlock_irqrestore(&cfv->tx_lock, flags);
cfv->ndev->stats.tx_dropped++;
free_buf_info(cfv, buf_info);
dev_kfree_skb(skb);
return NETDEV_TX_OK;
}
static void cfv_tx_release_tasklet(unsigned long drv)
{
struct cfv_info *cfv = (struct cfv_info *)drv;
cfv_release_used_buf(cfv->vq_tx);
}
static const struct net_device_ops cfv_netdev_ops = {
.ndo_open = cfv_netdev_open,
.ndo_stop = cfv_netdev_close,
.ndo_start_xmit = cfv_netdev_tx,
};
static void cfv_netdev_setup(struct net_device *netdev)
{
netdev->netdev_ops = &cfv_netdev_ops;
netdev->type = ARPHRD_CAIF;
netdev->tx_queue_len = 100;
netdev->flags = IFF_POINTOPOINT | IFF_NOARP;
netdev->mtu = CFV_DEF_MTU_SIZE;
netdev->needs_free_netdev = true;
}
/* Create debugfs counters for the device */
static inline void debugfs_init(struct cfv_info *cfv)
{
cfv->debugfs =
debugfs_create_dir(netdev_name(cfv->ndev), NULL);
if (IS_ERR(cfv->debugfs))
return;
debugfs_create_u32("rx-napi-complete", S_IRUSR, cfv->debugfs,
&cfv->stats.rx_napi_complete);
debugfs_create_u32("rx-napi-resched", S_IRUSR, cfv->debugfs,
&cfv->stats.rx_napi_resched);
debugfs_create_u32("rx-nomem", S_IRUSR, cfv->debugfs,
&cfv->stats.rx_nomem);
debugfs_create_u32("rx-kicks", S_IRUSR, cfv->debugfs,
&cfv->stats.rx_kicks);
debugfs_create_u32("tx-full-ring", S_IRUSR, cfv->debugfs,
&cfv->stats.tx_full_ring);
debugfs_create_u32("tx-no-mem", S_IRUSR, cfv->debugfs,
&cfv->stats.tx_no_mem);
debugfs_create_u32("tx-kicks", S_IRUSR, cfv->debugfs,
&cfv->stats.tx_kicks);
debugfs_create_u32("tx-flow-on", S_IRUSR, cfv->debugfs,
&cfv->stats.tx_flow_on);
}
/* Setup CAIF for the a virtio device */
static int cfv_probe(struct virtio_device *vdev)
{
vq_callback_t *vq_cbs = cfv_release_cb;
vrh_callback_t *vrh_cbs = cfv_recv;
const char *names = "output";
const char *cfv_netdev_name = "cfvrt";
struct net_device *netdev;
struct cfv_info *cfv;
int err = -EINVAL;
netdev = alloc_netdev(sizeof(struct cfv_info), cfv_netdev_name,
NET_NAME_UNKNOWN, cfv_netdev_setup);
if (!netdev)
return -ENOMEM;
cfv = netdev_priv(netdev);
cfv->vdev = vdev;
cfv->ndev = netdev;
spin_lock_init(&cfv->tx_lock);
/* Get the RX virtio ring. This is a "host side vring". */
err = -ENODEV;
if (!vdev->vringh_config || !vdev->vringh_config->find_vrhs)
goto err;
err = vdev->vringh_config->find_vrhs(vdev, 1, &cfv->vr_rx, &vrh_cbs);
if (err)
goto err;
/* Get the TX virtio ring. This is a "guest side vring". */
err = virtio_find_vqs(vdev, 1, &cfv->vq_tx, &vq_cbs, &names, NULL);
if (err)
goto err;
/* Get the CAIF configuration from virtio config space, if available */
if (vdev->config->get) {
virtio_cread(vdev, struct virtio_caif_transf_config, headroom,
&cfv->tx_hr);
virtio_cread(vdev, struct virtio_caif_transf_config, headroom,
&cfv->rx_hr);
virtio_cread(vdev, struct virtio_caif_transf_config, tailroom,
&cfv->tx_tr);
virtio_cread(vdev, struct virtio_caif_transf_config, tailroom,
&cfv->rx_tr);
virtio_cread(vdev, struct virtio_caif_transf_config, mtu,
&cfv->mtu);
virtio_cread(vdev, struct virtio_caif_transf_config, mtu,
&cfv->mru);
} else {
cfv->tx_hr = CFV_DEF_HEADROOM;
cfv->rx_hr = CFV_DEF_HEADROOM;
cfv->tx_tr = CFV_DEF_TAILROOM;
cfv->rx_tr = CFV_DEF_TAILROOM;
cfv->mtu = CFV_DEF_MTU_SIZE;
cfv->mru = CFV_DEF_MTU_SIZE;
}
netdev->needed_headroom = cfv->tx_hr;
netdev->needed_tailroom = cfv->tx_tr;
/* Disable buffer release interrupts unless we have stopped TX queues */
virtqueue_disable_cb(cfv->vq_tx);
netdev->mtu = cfv->mtu - cfv->tx_tr;
vdev->priv = cfv;
/* Initialize NAPI poll context data */
vringh_kiov_init(&cfv->ctx.riov, NULL, 0);
cfv->ctx.head = USHRT_MAX;
netif_napi_add(netdev, &cfv->napi, cfv_rx_poll, CFV_DEFAULT_QUOTA);
tasklet_init(&cfv->tx_release_tasklet,
cfv_tx_release_tasklet,
(unsigned long)cfv);
/* Carrier is off until netdevice is opened */
netif_carrier_off(netdev);
/* register Netdev */
err = register_netdev(netdev);
if (err) {
dev_err(&vdev->dev, "Unable to register netdev (%d)\n", err);
goto err;
}
debugfs_init(cfv);
return 0;
err:
netdev_warn(cfv->ndev, "CAIF Virtio probe failed:%d\n", err);
if (cfv->vr_rx)
vdev->vringh_config->del_vrhs(cfv->vdev);
if (cfv->vdev)
vdev->config->del_vqs(cfv->vdev);
free_netdev(netdev);
return err;
}
static void cfv_remove(struct virtio_device *vdev)
{
struct cfv_info *cfv = vdev->priv;
rtnl_lock();
dev_close(cfv->ndev);
rtnl_unlock();
tasklet_kill(&cfv->tx_release_tasklet);
debugfs_remove_recursive(cfv->debugfs);
vringh_kiov_cleanup(&cfv->ctx.riov);
vdev->config->reset(vdev);
vdev->vringh_config->del_vrhs(cfv->vdev);
cfv->vr_rx = NULL;
vdev->config->del_vqs(cfv->vdev);
unregister_netdev(cfv->ndev);
}
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_CAIF, VIRTIO_DEV_ANY_ID },
{ 0 },
};
static unsigned int features[] = {
};
static struct virtio_driver caif_virtio_driver = {
.feature_table = features,
.feature_table_size = ARRAY_SIZE(features),
.driver.name = KBUILD_MODNAME,
.driver.owner = THIS_MODULE,
.id_table = id_table,
.probe = cfv_probe,
.remove = cfv_remove,
};
module_virtio_driver(caif_virtio_driver);
MODULE_DEVICE_TABLE(virtio, id_table);