From: Vikram ARV Date: Tue, 19 Feb 2013 20:45:00 +0000 (+1030) Subject: caif_virtio: Introduce caif over virtio X-Git-Tag: next-20130220~60^2 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=49075de29b4fdc08eaec8bcd2c8f1f2238fa9e14;p=karo-tx-linux.git caif_virtio: Introduce caif over virtio Add the the Virtio shared memory driver for STE Modems. caif_virtio is implemented utilizing the virtio framework for data transport and is managed with the remoteproc frameworks. The Virtio queue is used for transmitting data to the modem, and the new vringh implementation is receiving data over the vring. Signed-off-by: Vikram ARV Signed-off-by: Sjur Brændeland cc: David S. Miller cc: Ohad Ben-Cohen cc: Rusty Russell cc: Ido Yariv cc: Erwan Yvin Signed-off-by: Rusty Russell --- diff --git a/drivers/net/caif/Kconfig b/drivers/net/caif/Kconfig index abf4d7a9dcce..a8b67e9be8be 100644 --- a/drivers/net/caif/Kconfig +++ b/drivers/net/caif/Kconfig @@ -47,3 +47,11 @@ config CAIF_HSI The caif low level driver for CAIF over HSI. Be aware that if you enable this then you also need to enable a low-level HSI driver. + +config CAIF_VIRTIO + tristate "CAIF virtio transport driver" + depends on CAIF + depends on REMOTEPROC + default n + ---help--- + The caif driver for CAIF over Virtio. diff --git a/drivers/net/caif/Makefile b/drivers/net/caif/Makefile index 91dff861560f..d9ee26a96c6e 100644 --- a/drivers/net/caif/Makefile +++ b/drivers/net/caif/Makefile @@ -13,3 +13,6 @@ obj-$(CONFIG_CAIF_SHM) += caif_shm.o # HSI interface obj-$(CONFIG_CAIF_HSI) += caif_hsi.o + +# Virtio interface +obj-$(CONFIG_CAIF_VIRTIO) += caif_virtio.o diff --git a/drivers/net/caif/caif_virtio.c b/drivers/net/caif/caif_virtio.c new file mode 100644 index 000000000000..df832e71ee57 --- /dev/null +++ b/drivers/net/caif/caif_virtio.c @@ -0,0 +1,547 @@ +/* + * Copyright (C) ST-Ericsson AB 2012 + * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com + * Authors: Vicram Arv / vikram.arv@stericsson.com, + * Dmitry Tarnyagin / dmitry.tarnyagin@stericsson.com + * Sjur Brendeland / sjur.brandeland@stericsson.com + * License terms: GNU General Public License (GPL) version 2 + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +MODULE_LICENSE("GPL v2"); +MODULE_AUTHOR("Vicram Arv "); +MODULE_AUTHOR("Sjur Brendeland vdev->priv; + tasklet_schedule(&cfv->tx_release_tasklet); +} + +/* This is invoked whenever the remote processor completed processing + * a TX msg we just sent it, 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); + WARN_ON_ONCE(irqs_disabled()); + + for (;;) { + unsigned int len; + struct token_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); + + if (!buf_info) + goto out; + + BUG_ON(!cfv->queued_tx); + if (--cfv->queued_tx <= cfv->watermark_tx) { + cfv->watermark_tx = 0; + netif_tx_wake_all_queues(cfv->ndev); + } + spin_unlock_irqrestore(&cfv->tx_lock, flags); + + dma_free_coherent(vq_tx->vdev->dev.parent->parent, + buf_info->size, buf_info->vaddr, + buf_info->dma_handle); + kfree(buf_info); + } + return; +out: + spin_unlock_irqrestore(&cfv->tx_lock, flags); +} + +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; + } + /* Reserve space for headers. */ + skb_reserve(skb, cfv->rx_hr + pad_len); + + memcpy(skb_put(skb, cfpkt_len), frm + cfv->rx_hr, cfpkt_len); + return skb; +} + +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; + + do { + skb = NULL; + 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 out; + + } + + 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 out; + + /* Push received packet up the stack. */ + 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); + + return rxcnt; + +out: + switch (err) { + case 0: + /* Empty ring, enable notifications and stop NAPI polling */ + if (!vringh_notify_enable_kern(cfv->vr_rx)) + napi_complete(napi); + + return rxcnt; + + case -ENOMEM: + 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; + } + + return rxcnt; +} + +static irqreturn_t cfv_recv(struct virtio_device *vdev, struct vringh *vr_rx) +{ + struct cfv_info *cfv = vdev->priv; + + vringh_notify_disable_kern(cfv->vr_rx); + napi_schedule(&cfv->napi); + return IRQ_HANDLED; +} + +static int cfv_netdev_open(struct net_device *netdev) +{ + struct cfv_info *cfv = netdev_priv(netdev); + + netif_carrier_on(netdev); + napi_enable(&cfv->napi); + return 0; +} + +static int cfv_netdev_close(struct net_device *netdev) +{ + struct cfv_info *cfv = netdev_priv(netdev); + + netif_carrier_off(netdev); + napi_disable(&cfv->napi); + return 0; +} + +static struct token_info *cfv_alloc_and_copy_to_dmabuf(struct cfv_info *cfv, + struct sk_buff *skb, + struct scatterlist *sg) +{ + struct caif_payload_info *info = (void *)&skb->cb; + struct token_info *buf_info = NULL; + u8 pad_len, hdr_ofs; + + 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 token_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; + + if (WARN_ON_ONCE(!cfv->vdev->dev.parent)) + goto err; + + /* allocate coherent memory for the buffers */ + buf_info->vaddr = + dma_alloc_coherent(cfv->vdev->dev.parent->parent, + buf_info->size, &buf_info->dma_handle, + GFP_ATOMIC); + if (unlikely(!buf_info->vaddr)) { + netdev_warn(cfv->ndev, + "Out of DMA memory (alloc %zu bytes)\n", + buf_info->size); + 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; +} + +/* This is invoked whenever the host processor application has sent + * up-link data. Send it in the TX VQ avail ring. + * + * CAIF Virtio sends does not use linked descriptors in the tx direction. + */ +static int cfv_netdev_tx(struct sk_buff *skb, struct net_device *netdev) +{ + struct cfv_info *cfv = netdev_priv(netdev); + struct token_info *buf_info; + struct scatterlist sg; + unsigned long flags; + int ret; + + buf_info = cfv_alloc_and_copy_to_dmabuf(cfv, skb, &sg); + + spin_lock_irqsave(&cfv->tx_lock, flags); + if (unlikely(!buf_info)) + goto flow_off; + + /* Add buffer to avail ring. Flow control below should ensure + * that this always succeedes + */ + ret = virtqueue_add_buf(cfv->vq_tx, &sg, 1, 0, + buf_info, GFP_ATOMIC); + + if (unlikely(WARN_ON(ret < 0))) { + kfree(buf_info); + goto flow_off; + } + + + /* update netdev statistics */ + cfv->queued_tx++; + cfv->ndev->stats.tx_packets++; + cfv->ndev->stats.tx_bytes += skb->len; + + /* tell the remote processor it has a pending message to read */ + virtqueue_kick(cfv->vq_tx); + + /* 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 (ret <= num_present_cpus()) { +flow_off: + cfv->watermark_tx = cfv->queued_tx >> 1; + netif_tx_stop_all_queues(netdev); + } + + spin_unlock_irqrestore(&cfv->tx_lock, flags); + + dev_kfree_skb(skb); + tasklet_schedule(&cfv->tx_release_tasklet); + 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; +} + +static int cfv_probe(struct virtio_device *vdev) +{ + vq_callback_t *vq_cbs = cfv_release_cb; + const char *names = "output"; + const char *cfv_netdev_name = "cfvrt"; + struct net_device *netdev; + struct virtqueue *vqs; + + struct cfv_info *cfv; + int err = 0; + + netdev = alloc_netdev(sizeof(struct cfv_info), cfv_netdev_name, + cfv_netdev_setup); + if (!netdev) + return -ENOMEM; + + cfv = netdev_priv(netdev); + cfv->vdev = vdev; + cfv->ndev = netdev; + + spin_lock_init(&cfv->tx_lock); + + cfv->vr_rx = rproc_virtio_new_vringh(vdev, RX_RING_INDEX, cfv_recv); + if (!cfv->vr_rx) + goto free_cfv; + + /* Get the TX (uplink) virtque */ + err = vdev->config->find_vqs(vdev, 1, &vqs, &vq_cbs, &names); + if (err) + goto free_cfv; + + cfv->vq_tx = vqs; + +#define GET_VIRTIO_CONFIG_OPS(_v, _var, _f) \ + ((_v)->config->get(_v, offsetof(struct virtio_caif_transf_config, _f), \ + &_var, \ + FIELD_SIZEOF(struct virtio_caif_transf_config, _f))) + + if (vdev->config->get) { + GET_VIRTIO_CONFIG_OPS(vdev, cfv->tx_hr, headroom); + GET_VIRTIO_CONFIG_OPS(vdev, cfv->rx_hr, headroom); + GET_VIRTIO_CONFIG_OPS(vdev, cfv->tx_tr, tailroom); + GET_VIRTIO_CONFIG_OPS(vdev, cfv->rx_tr, tailroom); + GET_VIRTIO_CONFIG_OPS(vdev, cfv->mtu, mtu); + GET_VIRTIO_CONFIG_OPS(vdev, cfv->mru, mtu); + } 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; + + /* Subtract needed tailroom from MTU to ensure enough room */ + netdev->mtu = cfv->mtu - cfv->tx_tr; + + vdev->priv = cfv; + + 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); + + netif_carrier_off(netdev); + + /* register Netdev */ + err = register_netdev(netdev); + if (err) { + dev_err(&vdev->dev, "Unable to register netdev (%d)\n", err); + goto vqs_del; + } + + /* tell the remote processor it can start sending messages */ + rproc_virtio_kick_vringh(vdev, RX_RING_INDEX); + + return 0; + +vqs_del: + vdev->config->del_vqs(cfv->vdev); +free_cfv: + free_netdev(netdev); + return err; +} + +static void cfv_remove(struct virtio_device *vdev) +{ + struct cfv_info *cfv = vdev->priv; + + tasklet_kill(&cfv->tx_release_tasklet); + vringh_kiov_cleanup(&cfv->ctx.riov); + vdev->config->reset(vdev); + rproc_virtio_del_vringh(vdev, RX_RING_INDEX); + 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); diff --git a/include/linux/virtio_caif.h b/include/linux/virtio_caif.h new file mode 100644 index 000000000000..5d2d3124ca3d --- /dev/null +++ b/include/linux/virtio_caif.h @@ -0,0 +1,24 @@ +/* + * Copyright (C) ST-Ericsson AB 2012 + * Author: Sjur Brændeland + * + * This header is BSD licensed so + * anyone can use the definitions to implement compatible remote processors + */ + +#ifndef VIRTIO_CAIF_H +#define VIRTIO_CAIF_H + +#include +struct virtio_caif_transf_config { + u16 headroom; + u16 tailroom; + u32 mtu; + u8 reserved[4]; +}; + +struct virtio_caif_config { + struct virtio_caif_transf_config uplink, downlink; + u8 reserved[8]; +}; +#endif diff --git a/include/uapi/linux/virtio_ids.h b/include/uapi/linux/virtio_ids.h index a7630d04029f..284fc3a05f7b 100644 --- a/include/uapi/linux/virtio_ids.h +++ b/include/uapi/linux/virtio_ids.h @@ -38,5 +38,6 @@ #define VIRTIO_ID_SCSI 8 /* virtio scsi */ #define VIRTIO_ID_9P 9 /* 9p virtio console */ #define VIRTIO_ID_RPROC_SERIAL 11 /* virtio remoteproc serial link */ +#define VIRTIO_ID_CAIF 12 /* Virtio caif */ #endif /* _LINUX_VIRTIO_IDS_H */