diff options
Diffstat (limited to 'drivers')
26 files changed, 1582 insertions, 178 deletions
diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c index 0ce02d7e5048..5e83ffa105e4 100644 --- a/drivers/char/hw_random/virtio-rng.c +++ b/drivers/char/hw_random/virtio-rng.c @@ -7,6 +7,7 @@ #include <asm/barrier.h> #include <linux/err.h> #include <linux/hw_random.h> +#include <linux/nospec.h> #include <linux/scatterlist.h> #include <linux/spinlock.h> #include <linux/virtio.h> @@ -69,8 +70,26 @@ static void request_entropy(struct virtrng_info *vi) static unsigned int copy_data(struct virtrng_info *vi, void *buf, unsigned int size) { - size = min_t(unsigned int, size, vi->data_avail); - memcpy(buf, vi->data + vi->data_idx, size); + unsigned int idx, avail; + + /* + * vi->data_avail was set from the device-reported used.len and + * vi->data_idx was advanced by previous copy_data() calls. A + * malicious or buggy virtio-rng backend can drive either past + * sizeof(vi->data). Clamp at point of use and harden the index + * with array_index_nospec() so the memcpy() below cannot be + * steered into adjacent slab memory, including under + * speculation. + */ + avail = min_t(unsigned int, vi->data_avail, sizeof(vi->data)); + if (vi->data_idx >= avail) { + vi->data_avail = 0; + request_entropy(vi); + return 0; + } + size = min_t(unsigned int, size, avail - vi->data_idx); + idx = array_index_nospec(vi->data_idx, sizeof(vi->data)); + memcpy(buf, vi->data + idx, size); vi->data_idx += size; vi->data_avail -= size; if (vi->data_avail == 0) diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index 9a33217c68d9..198b97314168 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1771,32 +1771,40 @@ static void config_intr(struct virtio_device *vdev) schedule_work(&portdev->config_work); } -static void config_work_handler(struct work_struct *work) +static void update_size_from_config(struct ports_device *portdev) { - struct ports_device *portdev; + struct virtio_device *vdev; + struct port *port; + u16 rows, cols; - portdev = container_of(work, struct ports_device, config_work); - if (!use_multiport(portdev)) { - struct virtio_device *vdev; - struct port *port; - u16 rows, cols; + vdev = portdev->vdev; - vdev = portdev->vdev; - virtio_cread(vdev, struct virtio_console_config, cols, &cols); - virtio_cread(vdev, struct virtio_console_config, rows, &rows); + /* + * We'll use this way of resizing only for legacy support. + * For multiport devices, use control messages to indicate + * console size changes so that it can be done per-port. + * + * Don't test F_SIZE at all if we're rproc: not a valid feature. + */ + if (is_rproc_serial(vdev) || + use_multiport(portdev) || + !virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) + return; - port = find_port_by_id(portdev, 0); - set_console_size(port, rows, cols); + virtio_cread(vdev, struct virtio_console_config, cols, &cols); + virtio_cread(vdev, struct virtio_console_config, rows, &rows); - /* - * We'll use this way of resizing only for legacy - * support. For newer userspace - * (VIRTIO_CONSOLE_F_MULTPORT+), use control messages - * to indicate console size changes so that it can be - * done per-port. - */ - resize_console(port); - } + port = find_port_by_id(portdev, 0); + set_console_size(port, rows, cols); + resize_console(port); +} + +static void config_work_handler(struct work_struct *work) +{ + struct ports_device *portdev; + + portdev = container_of(work, struct ports_device, config_work); + update_size_from_config(portdev); } static int init_vqs(struct ports_device *portdev) @@ -2052,6 +2060,8 @@ static int virtcons_probe(struct virtio_device *vdev) __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, VIRTIO_CONSOLE_DEVICE_READY, 1); + update_size_from_config(portdev); + return 0; free_chrdev: diff --git a/drivers/firmware/Kconfig b/drivers/firmware/Kconfig index bcfda01c2ab8..12dc70254842 100644 --- a/drivers/firmware/Kconfig +++ b/drivers/firmware/Kconfig @@ -124,7 +124,7 @@ config RASPBERRYPI_FIRMWARE config FW_CFG_SYSFS tristate "QEMU fw_cfg device support in sysfs" - depends on SYSFS && (ARM || ARM64 || PARISC || PPC_PMAC || RISCV || SPARC || X86) + depends on SYSFS && (ARM || ARM64 || LOONGARCH || PARISC || PPC_PMAC || RISCV || SPARC || X86) depends on HAS_IOPORT_MAP default n help diff --git a/drivers/firmware/qemu_fw_cfg.c b/drivers/firmware/qemu_fw_cfg.c index 87a5421bc7d5..0c51a9df589f 100644 --- a/drivers/firmware/qemu_fw_cfg.c +++ b/drivers/firmware/qemu_fw_cfg.c @@ -211,7 +211,7 @@ static void fw_cfg_io_cleanup(void) /* arch-specific ctrl & data register offsets are not available in ACPI, DT */ #if !(defined(FW_CFG_CTRL_OFF) && defined(FW_CFG_DATA_OFF)) -# if (defined(CONFIG_ARM) || defined(CONFIG_ARM64) || defined(CONFIG_RISCV)) +# if (defined(CONFIG_ARM) || defined(CONFIG_ARM64) || defined(CONFIG_LOONGARCH) || defined(CONFIG_RISCV)) # define FW_CFG_CTRL_OFF 0x08 # define FW_CFG_DATA_OFF 0x00 # define FW_CFG_DMA_OFF 0x10 diff --git a/drivers/net/can/Kconfig b/drivers/net/can/Kconfig index e15e320db476..e4058708ae68 100644 --- a/drivers/net/can/Kconfig +++ b/drivers/net/can/Kconfig @@ -226,6 +226,18 @@ config CAN_TI_HECC Driver for TI HECC (High End CAN Controller) module found on many TI devices. The device specifications are available from www.ti.com +config CAN_VIRTIO_CAN + depends on VIRTIO + tristate "Virtio CAN device support" + default n + help + Say Y here if you want to support for Virtio CAN. + + To compile this driver as a module, choose M here: the + module will be called virtio-can. + + If unsure, say N. + config CAN_XILINXCAN tristate "Xilinx CAN" depends on ARCH_ZYNQ || ARM64 || MICROBLAZE || COMPILE_TEST diff --git a/drivers/net/can/Makefile b/drivers/net/can/Makefile index d7bc10a6b8ea..4010d17f8583 100644 --- a/drivers/net/can/Makefile +++ b/drivers/net/can/Makefile @@ -33,6 +33,7 @@ obj-$(CONFIG_CAN_PEAK_PCIEFD) += peak_canfd/ obj-$(CONFIG_CAN_SJA1000) += sja1000/ obj-$(CONFIG_CAN_SUN4I) += sun4i_can.o obj-$(CONFIG_CAN_TI_HECC) += ti_hecc.o +obj-$(CONFIG_CAN_VIRTIO_CAN) += virtio_can.o obj-$(CONFIG_CAN_XILINXCAN) += xilinx_can.o subdir-ccflags-$(CONFIG_CAN_DEBUG_DEVICES) += -DDEBUG diff --git a/drivers/net/can/virtio_can.c b/drivers/net/can/virtio_can.c new file mode 100644 index 000000000000..f67d0bf09681 --- /dev/null +++ b/drivers/net/can/virtio_can.c @@ -0,0 +1,1022 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * CAN bus driver for the Virtio CAN controller + * + * Copyright (C) 2021-2023 OpenSynergy GmbH + * Copyright Red Hat, Inc. 2025 + */ + +#include <linux/atomic.h> +#include <linux/idr.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/mutex.h> +#include <linux/netdevice.h> +#include <linux/stddef.h> +#include <linux/can/dev.h> +#include <linux/virtio.h> +#include <linux/virtio_ring.h> +#include <linux/virtio_can.h> + +/* CAN device queues */ +#define VIRTIO_CAN_QUEUE_TX 0 +#define VIRTIO_CAN_QUEUE_RX 1 +#define VIRTIO_CAN_QUEUE_CONTROL 2 +#define VIRTIO_CAN_QUEUE_COUNT 3 + +#define CAN_KNOWN_FLAGS \ + (VIRTIO_CAN_FLAGS_EXTENDED |\ + VIRTIO_CAN_FLAGS_FD |\ + VIRTIO_CAN_FLAGS_RTR) + +/* Max. number of in flight TX messages */ +#define VIRTIO_CAN_ECHO_SKB_MAX 128 + +struct virtio_can_tx { + unsigned int putidx; + struct virtio_can_tx_in tx_in; + /* Keep virtio_can_tx_out at the end of the structure due to flex array */ + struct virtio_can_tx_out tx_out; +}; + +struct virtio_can_control { + struct virtio_can_control_out cpkt_out; + struct virtio_can_control_in cpkt_in; +}; + +/* virtio_can private data structure */ +struct virtio_can_priv { + struct can_priv can; /* must be the first member */ + /* NAPI for RX messages */ + struct napi_struct napi; + /* NAPI for TX messages */ + struct napi_struct napi_tx; + /* The network device we're associated with */ + struct net_device *dev; + /* The virtio device we're associated with */ + struct virtio_device *vdev; + /* The virtqueues */ + struct virtqueue *vqs[VIRTIO_CAN_QUEUE_COUNT]; + /* Lock for TX operations */ + spinlock_t tx_lock; + /* Control queue lock */ + struct mutex ctrl_lock; + /* Wait for control queue processing without polling */ + struct completion ctrl_done; + /* Array of receive queue messages */ + struct virtio_can_rx *rpkt; + struct virtio_can_control can_ctr_msg; + /* Data to get and maintain the putidx for local TX echo */ + struct ida tx_putidx_ida; + /* In flight TX messages */ + atomic_t tx_inflight; + /* Packet length */ + int rpkt_len; + /* BusOff pending. Reset after successful indication to upper layer */ + bool busoff_pending; + /* Tracks whether NAPI instances are currently enabled */ + bool napi_active; +}; + +static void virtqueue_napi_schedule(struct napi_struct *napi, + struct virtqueue *vq) +{ + if (napi_schedule_prep(napi)) { + virtqueue_disable_cb(vq); + __napi_schedule(napi); + } +} + +static void virtqueue_napi_complete(struct napi_struct *napi, + struct virtqueue *vq, int processed) +{ + int opaque; + + opaque = virtqueue_enable_cb_prepare(vq); + if (napi_complete_done(napi, processed)) { + if (unlikely(virtqueue_poll(vq, opaque))) + virtqueue_napi_schedule(napi, vq); + } else { + virtqueue_disable_cb(vq); + } +} + +static void virtio_can_free_candev(struct net_device *ndev) +{ + struct virtio_can_priv *priv = netdev_priv(ndev); + + ida_destroy(&priv->tx_putidx_ida); + free_candev(ndev); +} + +static void virtio_can_napi_enable(struct virtio_can_priv *priv) +{ + if (!priv->napi_active) { + napi_enable(&priv->napi); + napi_enable(&priv->napi_tx); + priv->napi_active = true; + } +} + +static void virtio_can_napi_disable(struct virtio_can_priv *priv) +{ + if (priv->napi_active) { + napi_disable(&priv->napi_tx); + napi_disable(&priv->napi); + priv->napi_active = false; + } +} + +static int virtio_can_alloc_tx_idx(struct virtio_can_priv *priv) +{ + int tx_idx; + + tx_idx = ida_alloc_max(&priv->tx_putidx_ida, + priv->can.echo_skb_max - 1, GFP_ATOMIC); + if (tx_idx >= 0) + atomic_inc(&priv->tx_inflight); + + return tx_idx; +} + +static void virtio_can_free_tx_idx(struct virtio_can_priv *priv, + unsigned int idx) +{ + ida_free(&priv->tx_putidx_ida, idx); + atomic_dec(&priv->tx_inflight); +} + +/* Create a scatter-gather list representing our input buffer and put + * it in the queue. + * + * Callers should take appropriate locks. + */ +static int virtio_can_add_inbuf(struct virtqueue *vq, void *buf, + unsigned int size) +{ + struct scatterlist sg[1]; + int ret; + + sg_init_one(sg, buf, size); + + ret = virtqueue_add_inbuf(vq, sg, 1, buf, GFP_ATOMIC); + + return ret; +} + +/* Send a control message with message type either + * + * - VIRTIO_CAN_SET_CTRL_MODE_START or + * - VIRTIO_CAN_SET_CTRL_MODE_STOP. + * + */ +static u8 virtio_can_send_ctrl_msg(struct net_device *ndev, u16 msg_type) +{ + struct scatterlist sg_out, sg_in, *sgs[2] = { &sg_out, &sg_in }; + struct virtio_can_priv *priv = netdev_priv(ndev); + struct virtqueue *vq = priv->vqs[VIRTIO_CAN_QUEUE_CONTROL]; + struct device *dev = &priv->vdev->dev; + unsigned int len; + int err; + + if (!vq) + return VIRTIO_CAN_RESULT_NOT_OK; + + guard(mutex)(&priv->ctrl_lock); + + priv->can_ctr_msg.cpkt_out.msg_type = cpu_to_le16(msg_type); + sg_init_one(&sg_out, &priv->can_ctr_msg.cpkt_out, + sizeof(priv->can_ctr_msg.cpkt_out)); + sg_init_one(&sg_in, &priv->can_ctr_msg.cpkt_in, sizeof(priv->can_ctr_msg.cpkt_in)); + + reinit_completion(&priv->ctrl_done); + + err = virtqueue_add_sgs(vq, sgs, 1u, 1u, priv, GFP_ATOMIC); + if (err != 0) { + dev_err(dev, "%s(): virtqueue_add_sgs() failed\n", __func__); + return VIRTIO_CAN_RESULT_NOT_OK; + } + + if (!virtqueue_kick(vq)) { + dev_err(dev, "%s(): Kick failed\n", __func__); + return VIRTIO_CAN_RESULT_NOT_OK; + } + + while (!virtqueue_get_buf(vq, &len) && !virtqueue_is_broken(vq)) + wait_for_completion(&priv->ctrl_done); + + return priv->can_ctr_msg.cpkt_in.result; +} + +static int virtio_can_start(struct net_device *ndev) +{ + struct virtio_can_priv *priv = netdev_priv(ndev); + u8 result; + + result = virtio_can_send_ctrl_msg(ndev, VIRTIO_CAN_SET_CTRL_MODE_START); + if (result != VIRTIO_CAN_RESULT_OK) { + netdev_err(ndev, "CAN controller start failed\n"); + return -EIO; + } + + priv->busoff_pending = false; + priv->can.state = CAN_STATE_ERROR_ACTIVE; + + return 0; +} + +static int virtio_can_set_mode(struct net_device *dev, enum can_mode mode) +{ + int err; + + switch (mode) { + case CAN_MODE_START: + err = virtio_can_start(dev); + if (err) + return err; + netif_wake_queue(dev); + break; + default: + return -EOPNOTSUPP; + } + + return 0; +} + +static int virtio_can_open(struct net_device *ndev) +{ + struct virtio_can_priv *priv = netdev_priv(ndev); + int err; + + err = open_candev(ndev); + if (err) + return err; + + err = virtio_can_start(ndev); + if (err) { + close_candev(ndev); + return err; + } + + virtio_can_napi_enable(priv); + netif_start_queue(ndev); + + return 0; +} + +static int virtio_can_stop(struct net_device *ndev) +{ + struct virtio_can_priv *priv = netdev_priv(ndev); + struct device *dev = &priv->vdev->dev; + u8 result; + + result = virtio_can_send_ctrl_msg(ndev, VIRTIO_CAN_SET_CTRL_MODE_STOP); + if (result != VIRTIO_CAN_RESULT_OK) { + dev_err(dev, "CAN controller stop failed\n"); + return -EIO; + } + + priv->busoff_pending = false; + priv->can.state = CAN_STATE_STOPPED; + + /* Switch carrier off if device was connected to the bus */ + if (netif_carrier_ok(ndev)) + netif_carrier_off(ndev); + + return 0; +} + +static int virtio_can_close(struct net_device *dev) +{ + struct virtio_can_priv *priv = netdev_priv(dev); + + netif_stop_queue(dev); + /* Ignore stop error: ndo_stop must always complete cleanup regardless. + * virtio_can_stop() already logs the error if it fails. + */ + virtio_can_stop(dev); + virtio_can_napi_disable(priv); + close_candev(dev); + + return 0; +} + +static netdev_tx_t virtio_can_start_xmit(struct sk_buff *skb, + struct net_device *dev) +{ + struct scatterlist sg_out, sg_in, *sgs[2] = { &sg_out, &sg_in }; + const unsigned int hdr_size = sizeof(struct virtio_can_tx_out); + struct canfd_frame *cf = (struct canfd_frame *)skb->data; + struct virtio_can_priv *priv = netdev_priv(dev); + struct virtqueue *vq = priv->vqs[VIRTIO_CAN_QUEUE_TX]; + netdev_tx_t xmit_ret = NETDEV_TX_OK; + struct virtio_can_tx *can_tx_msg; + u32 can_flags; + int putidx; + int err; + + if (can_dev_dropped_skb(dev, skb)) + goto kick; /* No way to return NET_XMIT_DROP here */ + + /* No local check for CAN_RTR_FLAG or FD frame against negotiated + * features. The device will reject those anyway if not supported. + */ + + can_tx_msg = kzalloc(sizeof(*can_tx_msg) + cf->len, GFP_ATOMIC); + if (!can_tx_msg) { + kfree_skb(skb); + dev->stats.tx_dropped++; + goto kick; /* No way to return NET_XMIT_DROP here */ + } + + can_tx_msg->tx_out.msg_type = cpu_to_le16(VIRTIO_CAN_TX); + can_tx_msg->tx_out.length = cpu_to_le16(cf->len); + can_flags = 0; + + if (cf->can_id & CAN_EFF_FLAG) { + can_flags |= VIRTIO_CAN_FLAGS_EXTENDED; + can_tx_msg->tx_out.can_id = cpu_to_le32(cf->can_id & CAN_EFF_MASK); + } else { + can_tx_msg->tx_out.can_id = cpu_to_le32(cf->can_id & CAN_SFF_MASK); + } + if (cf->can_id & CAN_RTR_FLAG) + can_flags |= VIRTIO_CAN_FLAGS_RTR; + else + memcpy(can_tx_msg->tx_out.sdu, cf->data, cf->len); + if (can_is_canfd_skb(skb)) + can_flags |= VIRTIO_CAN_FLAGS_FD; + + can_tx_msg->tx_out.flags = cpu_to_le32(can_flags); + + sg_init_one(&sg_out, &can_tx_msg->tx_out, hdr_size + cf->len); + sg_init_one(&sg_in, &can_tx_msg->tx_in, sizeof(can_tx_msg->tx_in)); + + putidx = virtio_can_alloc_tx_idx(priv); + + if (unlikely(putidx < 0)) { + /* -ENOMEM or -ENOSPC here. -ENOSPC should not be possible as + * tx_inflight >= can.echo_skb_max is checked in flow control + */ + WARN_ON_ONCE(putidx == -ENOSPC); + kfree(can_tx_msg); + kfree_skb(skb); + dev->stats.tx_dropped++; + goto kick; /* No way to return NET_XMIT_DROP here */ + } + + can_tx_msg->putidx = (unsigned int)putidx; + + /* Push loopback echo. Will be looped back on TX interrupt/TX NAPI */ + err = can_put_echo_skb(skb, dev, can_tx_msg->putidx, 0); + if (unlikely(err)) { + /* skb was already freed by can_put_echo_skb() on error */ + virtio_can_free_tx_idx(priv, can_tx_msg->putidx); + kfree(can_tx_msg); + dev->stats.tx_dropped++; + goto kick; + } + + /* Protect queue and list operations */ + scoped_guard(spinlock_irqsave, &priv->tx_lock) + err = virtqueue_add_sgs(vq, sgs, 1u, 1u, can_tx_msg, GFP_ATOMIC); + + if (unlikely(err)) { + /* + * can_put_echo_skb() already consumed skb via consume_skb(), + * so returning NETDEV_TX_BUSY would cause the stack to requeue + * a freed pointer. Drop the frame and return OK instead. + */ + can_free_echo_skb(dev, can_tx_msg->putidx, NULL); + virtio_can_free_tx_idx(priv, can_tx_msg->putidx); + netif_stop_queue(dev); + kfree(can_tx_msg); + dev->stats.tx_dropped++; + /* Expected never to be seen */ + netdev_warn(dev, "TX: Stop queue, err = %d\n", err); + goto kick; + } + + /* Normal flow control: stop queue when no transmission slots left */ + if (atomic_read(&priv->tx_inflight) >= priv->can.echo_skb_max || + vq->num_free == 0 || (vq->num_free < ARRAY_SIZE(sgs) && + !virtio_has_feature(vq->vdev, VIRTIO_RING_F_INDIRECT_DESC))) { + netif_stop_queue(dev); + netdev_dbg(dev, "TX: Normal stop queue\n"); + } + +kick: + if (netif_queue_stopped(dev) || !netdev_xmit_more()) { + scoped_guard(spinlock_irqsave, &priv->tx_lock) { + if (!virtqueue_kick(vq)) + netdev_err(dev, "%s(): Kick failed\n", __func__); + } + } + + return xmit_ret; +} + +static const struct net_device_ops virtio_can_netdev_ops = { + .ndo_open = virtio_can_open, + .ndo_stop = virtio_can_close, + .ndo_start_xmit = virtio_can_start_xmit, +}; + +static int register_virtio_can_dev(struct net_device *dev) +{ + dev->flags |= IFF_ECHO; /* we support local echo */ + dev->netdev_ops = &virtio_can_netdev_ops; + + return register_candev(dev); +} + +static int virtio_can_read_tx_queue(struct virtqueue *vq) +{ + struct virtio_can_priv *can_priv = vq->vdev->priv; + struct net_device *dev = can_priv->dev; + struct virtio_can_tx *can_tx_msg; + struct net_device_stats *stats; + unsigned int len; + u8 result; + + stats = &dev->stats; + + scoped_guard(spinlock_irqsave, &can_priv->tx_lock) + can_tx_msg = virtqueue_get_buf(vq, &len); + + if (!can_tx_msg) + return 0; + + if (unlikely(len < sizeof(struct virtio_can_tx_in))) { + netdev_err(dev, "TX ACK: Device sent no result code\n"); + result = VIRTIO_CAN_RESULT_NOT_OK; /* Keep things going */ + } else { + result = can_tx_msg->tx_in.result; + } + + if (can_priv->can.state < CAN_STATE_BUS_OFF) { + if (result != VIRTIO_CAN_RESULT_OK) { + struct can_frame *skb_cf; + struct sk_buff *skb = alloc_can_err_skb(dev, &skb_cf); + + if (skb) { + skb_cf->can_id |= CAN_ERR_CRTL; + skb_cf->data[1] |= CAN_ERR_CRTL_UNSPEC; + netif_rx(skb); + } + netdev_warn(dev, "TX ACK: Result = %u\n", result); + can_free_echo_skb(dev, can_tx_msg->putidx, NULL); + stats->tx_dropped++; + } else { + stats->tx_bytes += can_get_echo_skb(dev, can_tx_msg->putidx, + NULL); + stats->tx_packets++; + } + } else { + netdev_dbg(dev, "TX ACK: Controller inactive, drop echo\n"); + can_free_echo_skb(dev, can_tx_msg->putidx, NULL); + stats->tx_dropped++; + } + + virtio_can_free_tx_idx(can_priv, can_tx_msg->putidx); + + /* Flow control */ + if (netif_queue_stopped(dev)) { + netdev_dbg(dev, "TX ACK: Wake up stopped queue\n"); + netif_wake_queue(dev); + } + + kfree(can_tx_msg); + + return 1; /* Queue was not empty so there may be more data */ +} + +static int virtio_can_tx_poll(struct napi_struct *napi, int quota) +{ + struct net_device *dev = napi->dev; + struct virtio_can_priv *priv = netdev_priv(dev); + struct virtqueue *vq = priv->vqs[VIRTIO_CAN_QUEUE_TX]; + int work_done = 0; + + while (work_done < quota && virtio_can_read_tx_queue(vq) != 0) + work_done++; + + if (work_done < quota) + virtqueue_napi_complete(napi, vq, work_done); + + return work_done; +} + +static void virtio_can_tx_intr(struct virtqueue *vq) +{ + struct virtio_can_priv *can_priv = vq->vdev->priv; + + virtqueue_disable_cb(vq); + napi_schedule(&can_priv->napi_tx); +} + +/* This function is the NAPI RX poll function and NAPI guarantees that this + * function is not invoked simultaneously on multiple processors. + * Read a RX message from the used queue and sends it to the upper layer. + */ +static int virtio_can_read_rx_queue(struct virtqueue *vq) +{ + const unsigned int header_size = sizeof(struct virtio_can_rx); + struct virtio_can_priv *priv = vq->vdev->priv; + struct net_device *dev = priv->dev; + struct net_device_stats *stats; + struct virtio_can_rx *can_rx; + unsigned int transport_len; + struct canfd_frame *cf; + struct sk_buff *skb; + unsigned int len; + u32 can_flags; + u16 msg_type; + u32 can_id; + int ret; + + stats = &dev->stats; + + can_rx = virtqueue_get_buf(vq, &transport_len); + if (!can_rx) + return 0; /* No more data */ + + if (transport_len < header_size) { + netdev_warn(dev, "RX: Message too small\n"); + goto putback; + } + + if (priv->can.state >= CAN_STATE_ERROR_PASSIVE) { + netdev_dbg(dev, "%s(): Controller not active\n", __func__); + goto putback; + } + + msg_type = le16_to_cpu(can_rx->msg_type); + if (msg_type != VIRTIO_CAN_RX) { + netdev_warn(dev, "RX: Got unknown msg_type %04x\n", msg_type); + goto putback; + } + + len = le16_to_cpu(can_rx->length); + can_flags = le32_to_cpu(can_rx->flags); + can_id = le32_to_cpu(can_rx->can_id); + + if (can_flags & ~CAN_KNOWN_FLAGS) { + stats->rx_dropped++; + netdev_warn(dev, "RX: CAN Id 0x%08x: Invalid flags 0x%x\n", + can_id, can_flags); + goto putback; + } + + if (can_flags & VIRTIO_CAN_FLAGS_EXTENDED) { + can_id &= CAN_EFF_MASK; + can_id |= CAN_EFF_FLAG; + } else { + can_id &= CAN_SFF_MASK; + } + + if (can_flags & VIRTIO_CAN_FLAGS_RTR) { + if (!virtio_has_feature(vq->vdev, VIRTIO_CAN_F_RTR_FRAMES)) { + stats->rx_dropped++; + netdev_warn(dev, "RX: CAN Id 0x%08x: RTR not negotiated\n", + can_id); + goto putback; + } + if (can_flags & VIRTIO_CAN_FLAGS_FD) { + stats->rx_dropped++; + netdev_warn(dev, "RX: CAN Id 0x%08x: RTR with FD not possible\n", + can_id); + goto putback; + } + + if (len > 0xF) { + stats->rx_dropped++; + netdev_warn(dev, "RX: CAN Id 0x%08x: RTR with DLC > 0xF\n", + can_id); + goto putback; + } + + if (len > 0x8) + len = 0x8; + + can_id |= CAN_RTR_FLAG; + } + + if (transport_len < header_size + len) { + netdev_warn(dev, "RX: Message too small for payload\n"); + goto putback; + } + + if (can_flags & VIRTIO_CAN_FLAGS_FD) { + if (!virtio_has_feature(vq->vdev, VIRTIO_CAN_F_CAN_FD)) { + stats->rx_dropped++; + netdev_warn(dev, "RX: CAN Id 0x%08x: FD not negotiated\n", + can_id); + goto putback; + } + + if (len > CANFD_MAX_DLEN) + len = CANFD_MAX_DLEN; + + skb = alloc_canfd_skb(priv->dev, &cf); + } else { + if (!virtio_has_feature(vq->vdev, VIRTIO_CAN_F_CAN_CLASSIC)) { + stats->rx_dropped++; + netdev_warn(dev, "RX: CAN Id 0x%08x: classic not negotiated\n", + can_id); + goto putback; + } + + if (len > CAN_MAX_DLEN) + len = CAN_MAX_DLEN; + + skb = alloc_can_skb(priv->dev, (struct can_frame **)&cf); + } + if (!skb) { + stats->rx_dropped++; + netdev_warn(dev, "RX: No skb available\n"); + goto putback; + } + + cf->can_id = can_id; + cf->len = len; + if (!(can_flags & VIRTIO_CAN_FLAGS_RTR)) { + /* RTR frames have a DLC but no payload */ + memcpy(cf->data, can_rx->sdu, len); + } + + if (netif_receive_skb(skb) == NET_RX_SUCCESS) { + stats->rx_packets++; + if (!(can_flags & VIRTIO_CAN_FLAGS_RTR)) + stats->rx_bytes += len; + } + +putback: + /* Put processed RX buffer back into avail queue */ + ret = virtio_can_add_inbuf(vq, can_rx, + priv->rpkt_len); + if (!ret) + virtqueue_kick(vq); + return 1; /* Queue was not empty so there may be more data */ +} + +static int virtio_can_handle_busoff(struct net_device *dev) +{ + struct virtio_can_priv *priv = netdev_priv(dev); + struct can_frame *cf; + struct sk_buff *skb; + + if (!priv->busoff_pending) + return 0; + + if (priv->can.state < CAN_STATE_BUS_OFF) { + netdev_dbg(dev, "entered error bus off state\n"); + + /* bus-off state */ + priv->can.state = CAN_STATE_BUS_OFF; + priv->can.can_stats.bus_off++; + can_bus_off(dev); + } + + /* propagate the error condition to the CAN stack */ + skb = alloc_can_err_skb(dev, &cf); + if (unlikely(!skb)) + return 0; + + /* bus-off state */ + cf->can_id |= CAN_ERR_BUSOFF; + + /* Ensure that the BusOff indication does not get lost */ + if (netif_receive_skb(skb) == NET_RX_SUCCESS) + priv->busoff_pending = false; + + return 1; +} + +static int virtio_can_rx_poll(struct napi_struct *napi, int quota) +{ + struct net_device *dev = napi->dev; + struct virtio_can_priv *priv = netdev_priv(dev); + struct virtqueue *vq = priv->vqs[VIRTIO_CAN_QUEUE_RX]; + int work_done = 0; + + work_done += virtio_can_handle_busoff(dev); + + while (work_done < quota && virtio_can_read_rx_queue(vq) != 0) + work_done++; + + if (work_done < quota) + virtqueue_napi_complete(napi, vq, work_done); + + return work_done; +} + +static void virtio_can_rx_intr(struct virtqueue *vq) +{ + struct virtio_can_priv *can_priv = vq->vdev->priv; + + virtqueue_disable_cb(vq); + napi_schedule(&can_priv->napi); +} + +static void virtio_can_control_intr(struct virtqueue *vq) +{ + struct virtio_can_priv *can_priv = vq->vdev->priv; + + complete(&can_priv->ctrl_done); +} + +static void virtio_can_config_changed(struct virtio_device *vdev) +{ + struct virtio_can_priv *can_priv = vdev->priv; + u16 status; + + status = virtio_cread16(vdev, offsetof(struct virtio_can_config, + status)); + + if (!(status & VIRTIO_CAN_S_CTRL_BUSOFF)) + return; + + if (!can_priv->busoff_pending && + can_priv->can.state < CAN_STATE_BUS_OFF) { + can_priv->busoff_pending = true; + napi_schedule(&can_priv->napi); + } +} + +static void virtio_can_populate_rx_vq(struct virtio_device *vdev) +{ + struct virtio_can_priv *priv = vdev->priv; + struct virt |