--- /dev/null
+/*
+ * 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);
+
+ memcpy(skb_put(skb, cfpkt_len), 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->destructor = free_netdev;
+}
+
+/* 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 = vdev->config->find_vqs(vdev, 1, &cfv->vq_tx, &vq_cbs, &names);
+ 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);
Code Review / kvmfornfv.git / blobdiff