diff options
Diffstat (limited to 'drivers/tty/hvc/virtio_console.c')
| -rw-r--r-- | drivers/tty/hvc/virtio_console.c | 1838 |
1 files changed, 0 insertions, 1838 deletions
diff --git a/drivers/tty/hvc/virtio_console.c b/drivers/tty/hvc/virtio_console.c deleted file mode 100644 index 896a2ced1d27..000000000000 --- a/drivers/tty/hvc/virtio_console.c +++ /dev/null @@ -1,1838 +0,0 @@ -/* - * Copyright (C) 2006, 2007, 2009 Rusty Russell, IBM Corporation - * Copyright (C) 2009, 2010 Red Hat, Inc. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ -#include <linux/cdev.h> -#include <linux/debugfs.h> -#include <linux/device.h> -#include <linux/err.h> -#include <linux/fs.h> -#include <linux/init.h> -#include <linux/list.h> -#include <linux/poll.h> -#include <linux/sched.h> -#include <linux/slab.h> -#include <linux/spinlock.h> -#include <linux/virtio.h> -#include <linux/virtio_console.h> -#include <linux/wait.h> -#include <linux/workqueue.h> -#include "hvc_console.h" - -/* - * This is a global struct for storing common data for all the devices - * this driver handles. - * - * Mainly, it has a linked list for all the consoles in one place so - * that callbacks from hvc for get_chars(), put_chars() work properly - * across multiple devices and multiple ports per device. - */ -struct ports_driver_data { - /* Used for registering chardevs */ - struct class *class; - - /* Used for exporting per-port information to debugfs */ - struct dentry *debugfs_dir; - - /* List of all the devices we're handling */ - struct list_head portdevs; - - /* Number of devices this driver is handling */ - unsigned int index; - - /* - * This is used to keep track of the number of hvc consoles - * spawned by this driver. This number is given as the first - * argument to hvc_alloc(). To correctly map an initial - * console spawned via hvc_instantiate to the console being - * hooked up via hvc_alloc, we need to pass the same vtermno. - * - * We also just assume the first console being initialised was - * the first one that got used as the initial console. - */ - unsigned int next_vtermno; - - /* All the console devices handled by this driver */ - struct list_head consoles; -}; -static struct ports_driver_data pdrvdata; - -DEFINE_SPINLOCK(pdrvdata_lock); - -/* This struct holds information that's relevant only for console ports */ -struct console { - /* We'll place all consoles in a list in the pdrvdata struct */ - struct list_head list; - - /* The hvc device associated with this console port */ - struct hvc_struct *hvc; - - /* The size of the console */ - struct winsize ws; - - /* - * This number identifies the number that we used to register - * with hvc in hvc_instantiate() and hvc_alloc(); this is the - * number passed on by the hvc callbacks to us to - * differentiate between the other console ports handled by - * this driver - */ - u32 vtermno; -}; - -struct port_buffer { - char *buf; - - /* size of the buffer in *buf above */ - size_t size; - - /* used length of the buffer */ - size_t len; - /* offset in the buf from which to consume data */ - size_t offset; -}; - -/* - * This is a per-device struct that stores data common to all the - * ports for that device (vdev->priv). - */ -struct ports_device { - /* Next portdev in the list, head is in the pdrvdata struct */ - struct list_head list; - - /* - * Workqueue handlers where we process deferred work after - * notification - */ - struct work_struct control_work; - - struct list_head ports; - - /* To protect the list of ports */ - spinlock_t ports_lock; - - /* To protect the vq operations for the control channel */ - spinlock_t cvq_lock; - - /* The current config space is stored here */ - struct virtio_console_config config; - - /* The virtio device we're associated with */ - struct virtio_device *vdev; - - /* - * A couple of virtqueues for the control channel: one for - * guest->host transfers, one for host->guest transfers - */ - struct virtqueue *c_ivq, *c_ovq; - - /* Array of per-port IO virtqueues */ - struct virtqueue **in_vqs, **out_vqs; - - /* Used for numbering devices for sysfs and debugfs */ - unsigned int drv_index; - - /* Major number for this device. Ports will be created as minors. */ - int chr_major; -}; - -/* This struct holds the per-port data */ -struct port { - /* Next port in the list, head is in the ports_device */ - struct list_head list; - - /* Pointer to the parent virtio_console device */ - struct ports_device *portdev; - - /* The current buffer from which data has to be fed to readers */ - struct port_buffer *inbuf; - - /* - * To protect the operations on the in_vq associated with this - * port. Has to be a spinlock because it can be called from - * interrupt context (get_char()). - */ - spinlock_t inbuf_lock; - - /* Protect the operations on the out_vq. */ - spinlock_t outvq_lock; - - /* The IO vqs for this port */ - struct virtqueue *in_vq, *out_vq; - - /* File in the debugfs directory that exposes this port's information */ - struct dentry *debugfs_file; - - /* - * The entries in this struct will be valid if this port is - * hooked up to an hvc console - */ - struct console cons; - - /* Each port associates with a separate char device */ - struct cdev *cdev; - struct device *dev; - - /* Reference-counting to handle port hot-unplugs and file operations */ - struct kref kref; - - /* A waitqueue for poll() or blocking read operations */ - wait_queue_head_t waitqueue; - - /* The 'name' of the port that we expose via sysfs properties */ - char *name; - - /* We can notify apps of host connect / disconnect events via SIGIO */ - struct fasync_struct *async_queue; - - /* The 'id' to identify the port with the Host */ - u32 id; - - bool outvq_full; - - /* Is the host device open */ - bool host_connected; - - /* We should allow only one process to open a port */ - bool guest_connected; -}; - -/* This is the very early arch-specified put chars function. */ -static int (*early_put_chars)(u32, const char *, int); - -static struct port *find_port_by_vtermno(u32 vtermno) -{ - struct port *port; - struct console *cons; - unsigned long flags; - - spin_lock_irqsave(&pdrvdata_lock, flags); - list_for_each_entry(cons, &pdrvdata.consoles, list) { - if (cons->vtermno == vtermno) { - port = container_of(cons, struct port, cons); - goto out; - } - } - port = NULL; -out: - spin_unlock_irqrestore(&pdrvdata_lock, flags); - return port; -} - -static struct port *find_port_by_devt_in_portdev(struct ports_device *portdev, - dev_t dev) -{ - struct port *port; - unsigned long flags; - - spin_lock_irqsave(&portdev->ports_lock, flags); - list_for_each_entry(port, &portdev->ports, list) - if (port->cdev->dev == dev) - goto out; - port = NULL; -out: - spin_unlock_irqrestore(&portdev->ports_lock, flags); - - return port; -} - -static struct port *find_port_by_devt(dev_t dev) -{ - struct ports_device *portdev; - struct port *port; - unsigned long flags; - - spin_lock_irqsave(&pdrvdata_lock, flags); - list_for_each_entry(portdev, &pdrvdata.portdevs, list) { - port = find_port_by_devt_in_portdev(portdev, dev); - if (port) - goto out; - } - port = NULL; -out: - spin_unlock_irqrestore(&pdrvdata_lock, flags); - return port; -} - -static struct port *find_port_by_id(struct ports_device *portdev, u32 id) -{ - struct port *port; - unsigned long flags; - - spin_lock_irqsave(&portdev->ports_lock, flags); - list_for_each_entry(port, &portdev->ports, list) - if (port->id == id) - goto out; - port = NULL; -out: - spin_unlock_irqrestore(&portdev->ports_lock, flags); - - return port; -} - -static struct port *find_port_by_vq(struct ports_device *portdev, - struct virtqueue *vq) -{ - struct port *port; - unsigned long flags; - - spin_lock_irqsave(&portdev->ports_lock, flags); - list_for_each_entry(port, &portdev->ports, list) - if (port->in_vq == vq || port->out_vq == vq) - goto out; - port = NULL; -out: - spin_unlock_irqrestore(&portdev->ports_lock, flags); - return port; -} - -static bool is_console_port(struct port *port) -{ - if (port->cons.hvc) - return true; - return false; -} - -static inline bool use_multiport(struct ports_device *portdev) -{ - /* - * This condition can be true when put_chars is called from - * early_init - */ - if (!portdev->vdev) - return 0; - return portdev->vdev->features[0] & (1 << VIRTIO_CONSOLE_F_MULTIPORT); -} - -static void free_buf(struct port_buffer *buf) -{ - kfree(buf->buf); - kfree(buf); -} - -static struct port_buffer *alloc_buf(size_t buf_size) -{ - struct port_buffer *buf; - - buf = kmalloc(sizeof(*buf), GFP_KERNEL); - if (!buf) - goto fail; - buf->buf = kzalloc(buf_size, GFP_KERNEL); - if (!buf->buf) - goto free_buf; - buf->len = 0; - buf->offset = 0; - buf->size = buf_size; - return buf; - -free_buf: - kfree(buf); -fail: - return NULL; -} - -/* Callers should take appropriate locks */ -static void *get_inbuf(struct port *port) -{ - struct port_buffer *buf; - struct virtqueue *vq; - unsigned int len; - - vq = port->in_vq; - buf = virtqueue_get_buf(vq, &len); - if (buf) { - buf->len = len; - buf->offset = 0; - } - return buf; -} - -/* - * Create a scatter-gather list representing our input buffer and put - * it in the queue. - * - * Callers should take appropriate locks. - */ -static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf) -{ - struct scatterlist sg[1]; - int ret; - - sg_init_one(sg, buf->buf, buf->size); - - ret = virtqueue_add_buf(vq, sg, 0, 1, buf); - virtqueue_kick(vq); - return ret; -} - -/* Discard any unread data this port has. Callers lockers. */ -static void discard_port_data(struct port *port) -{ - struct port_buffer *buf; - struct virtqueue *vq; - unsigned int len; - int ret; - - vq = port->in_vq; - if (port->inbuf) - buf = port->inbuf; - else - buf = virtqueue_get_buf(vq, &len); - - ret = 0; - while (buf) { - if (add_inbuf(vq, buf) < 0) { - ret++; - free_buf(buf); - } - buf = virtqueue_get_buf(vq, &len); - } - port->inbuf = NULL; - if (ret) - dev_warn(port->dev, "Errors adding %d buffers back to vq\n", - ret); -} - -static bool port_has_data(struct port *port) -{ - unsigned long flags; - bool ret; - - spin_lock_irqsave(&port->inbuf_lock, flags); - if (port->inbuf) { - ret = true; - goto out; - } - port->inbuf = get_inbuf(port); - if (port->inbuf) { - ret = true; - goto out; - } - ret = false; -out: - spin_unlock_irqrestore(&port->inbuf_lock, flags); - return ret; -} - -static ssize_t __send_control_msg(struct ports_device *portdev, u32 port_id, - unsigned int event, unsigned int value) -{ - struct scatterlist sg[1]; - struct virtio_console_control cpkt; - struct virtqueue *vq; - unsigned int len; - - if (!use_multiport(portdev)) - return 0; - - cpkt.id = port_id; - cpkt.event = event; - cpkt.value = value; - - vq = portdev->c_ovq; - - sg_init_one(sg, &cpkt, sizeof(cpkt)); - if (virtqueue_add_buf(vq, sg, 1, 0, &cpkt) >= 0) { - virtqueue_kick(vq); - while (!virtqueue_get_buf(vq, &len)) - cpu_relax(); - } - return 0; -} - -static ssize_t send_control_msg(struct port *port, unsigned int event, - unsigned int value) -{ - /* Did the port get unplugged before userspace closed it? */ - if (port->portdev) - return __send_control_msg(port->portdev, port->id, event, value); - return 0; -} - -/* Callers must take the port->outvq_lock */ -static void reclaim_consumed_buffers(struct port *port) -{ - void *buf; - unsigned int len; - - while ((buf = virtqueue_get_buf(port->out_vq, &len))) { - kfree(buf); - port->outvq_full = false; - } -} - -static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count, - bool nonblock) -{ - struct scatterlist sg[1]; - struct virtqueue *out_vq; - ssize_t ret; - unsigned long flags; - unsigned int len; - - out_vq = port->out_vq; - - spin_lock_irqsave(&port->outvq_lock, flags); - - reclaim_consumed_buffers(port); - - sg_init_one(sg, in_buf, in_count); - ret = virtqueue_add_buf(out_vq, sg, 1, 0, in_buf); - - /* Tell Host to go! */ - virtqueue_kick(out_vq); - - if (ret < 0) { - in_count = 0; - goto done; - } - - if (ret == 0) - port->outvq_full = true; - - if (nonblock) - goto done; - - /* - * Wait till the host acknowledges it pushed out the data we - * sent. This is done for data from the hvc_console; the tty - * operations are performed with spinlocks held so we can't - * sleep here. An alternative would be to copy the data to a - * buffer and relax the spinning requirement. The downside is - * we need to kmalloc a GFP_ATOMIC buffer each time the - * console driver writes something out. - */ - while (!virtqueue_get_buf(out_vq, &len)) - cpu_relax(); -done: - spin_unlock_irqrestore(&port->outvq_lock, flags); - /* - * We're expected to return the amount of data we wrote -- all - * of it - */ - return in_count; -} - -/* - * Give out the data that's requested from the buffer that we have - * queued up. - */ -static ssize_t fill_readbuf(struct port *port, char *out_buf, size_t out_count, - bool to_user) -{ - struct port_buffer *buf; - unsigned long flags; - - if (!out_count || !port_has_data(port)) - return 0; - - buf = port->inbuf; - out_count = min(out_count, buf->len - buf->offset); - - if (to_user) { - ssize_t ret; - - ret = copy_to_user(out_buf, buf->buf + buf->offset, out_count); - if (ret) - return -EFAULT; - } else { - memcpy(out_buf, buf->buf + buf->offset, out_count); - } - - buf->offset += out_count; - - if (buf->offset == buf->len) { - /* - * We're done using all the data in this buffer. - * Re-queue so that the Host can send us more data. - */ - spin_lock_irqsave(&port->inbuf_lock, flags); - port->inbuf = NULL; - - if (add_inbuf(port->in_vq, buf) < 0) - dev_warn(port->dev, "failed add_buf\n"); - - spin_unlock_irqrestore(&port->inbuf_lock, flags); - } - /* Return the number of bytes actually copied */ - return out_count; -} - -/* The condition that must be true for polling to end */ -static bool will_read_block(struct port *port) -{ - if (!port->guest_connected) { - /* Port got hot-unplugged. Let's exit. */ - return false; - } - return !port_has_data(port) && port->host_connected; -} - -static bool will_write_block(struct port *port) -{ - bool ret; - - if (!port->guest_connected) { - /* Port got hot-unplugged. Let's exit. */ - return false; - } - if (!port->host_connected) - return true; - - spin_lock_irq(&port->outvq_lock); - /* - * Check if the Host has consumed any buffers since we last - * sent data (this is only applicable for nonblocking ports). - */ - reclaim_consumed_buffers(port); - ret = port->outvq_full; - spin_unlock_irq(&port->outvq_lock); - - return ret; -} - -static ssize_t port_fops_read(struct file *filp, char __user *ubuf, - size_t count, loff_t *offp) -{ - struct port *port; - ssize_t ret; - - port = filp->private_data; - - if (!port_has_data(port)) { - /* - * If nothing's connected on the host just return 0 in - * case of list_empty; this tells the userspace app - * that there's no connection - */ - if (!port->host_connected) - return 0; - if (filp->f_flags & O_NONBLOCK) - return -EAGAIN; - - ret = wait_event_interruptible(port->waitqueue, - !will_read_block(port)); - if (ret < 0) - return ret; - } - /* Port got hot-unplugged. */ - if (!port->guest_connected) - return -ENODEV; - /* - * We could've received a disconnection message while we were - * waiting for more data. - * - * This check is not clubbed in the if() statement above as we - * might receive some data as well as the host could get - * disconnected after we got woken up from our wait. So we - * really want to give off whatever data we have and only then - * check for host_connected. - */ - if (!port_has_data(port) && !port->host_connected) - return 0; - - return fill_readbuf(port, ubuf, count, true); -} - -static ssize_t port_fops_write(struct file *filp, const char __user *ubuf, - size_t count, loff_t *offp) -{ - struct port *port; - char *buf; - ssize_t ret; - bool nonblock; - - /* Userspace could be out to fool us */ - if (!count) - return 0; - - port = filp->private_data; - - nonblock = filp->f_flags & O_NONBLOCK; - - if (will_write_block(port)) { - if (nonblock) - return -EAGAIN; - - ret = wait_event_interruptible(port->waitqueue, - !will_write_block(port)); - if (ret < 0) - return ret; - } - /* Port got hot-unplugged. */ - if (!port->guest_connected) - return -ENODEV; - - count = min((size_t)(32 * 1024), count); - - buf = kmalloc(count, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - ret = copy_from_user(buf, ubuf, count); - if (ret) { - ret = -EFAULT; - goto free_buf; - } - - /* - * We now ask send_buf() to not spin for generic ports -- we - * can re-use the same code path that non-blocking file - * descriptors take for blocking file descriptors since the - * wait is already done and we're certain the write will go - * through to the host. - */ - nonblock = true; - ret = send_buf(port, buf, count, nonblock); - - if (nonblock && ret > 0) - goto out; - -free_buf: - kfree(buf); -out: - return ret; -} - -static unsigned int port_fops_poll(struct file *filp, poll_table *wait) -{ - struct port *port; - unsigned int ret; - - port = filp->private_data; - poll_wait(filp, &port->waitqueue, wait); - - if (!port->guest_connected) { - /* Port got unplugged */ - return POLLHUP; - } - ret = 0; - if (!will_read_block(port)) - ret |= POLLIN | POLLRDNORM; - if (!will_write_block(port)) - ret |= POLLOUT; - if (!port->host_connected) - ret |= POLLHUP; - - return ret; -} - -static void remove_port(struct kref *kref); - -static int port_fops_release(struct inode *inode, struct file *filp) -{ - struct port *port; - - port = filp->private_data; - - /* Notify host of port being closed */ - send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 0); - - spin_lock_irq(&port->inbuf_lock); - port->guest_connected = false; - - discard_port_data(port); - - spin_unlock_irq(&port->inbuf_lock); - - spin_lock_irq(&port->outvq_lock); - reclaim_consumed_buffers(port); - spin_unlock_irq(&port->outvq_lock); - - /* - * Locks aren't necessary here as a port can't be opened after - * unplug, and if a port isn't unplugged, a kref would already - * exist for the port. Plus, taking ports_lock here would - * create a dependency on other locks taken by functions - * inside remove_port if we're the last holder of the port, - * creating many problems. - */ - kref_put(&port->kref, remove_port); - - return 0; -} - -static int port_fops_open(struct inode *inode, struct file *filp) -{ - struct cdev *cdev = inode->i_cdev; - struct port *port; - int ret; - - port = find_port_by_devt(cdev->dev); - filp->private_data = port; - - /* Prevent against a port getting hot-unplugged at the same time */ - spin_lock_irq(&port->portdev->ports_lock); - kref_get(&port->kref); - spin_unlock_irq(&port->portdev->ports_lock); - - /* - * Don't allow opening of console port devices -- that's done - * via /dev/hvc - */ - if (is_console_port(port)) { - ret = -ENXIO; - goto out; - } - - /* Allow only one process to open a particular port at a time */ - spin_lock_irq(&port->inbuf_lock); - if (port->guest_connected) { - spin_unlock_irq(&port->inbuf_lock); - ret = -EMFILE; - goto out; - } - - port->guest_connected = true; - spin_unlock_irq(&port->inbuf_lock); - - spin_lock_irq(&port->outvq_lock); - /* - * There might be a chance that we missed reclaiming a few - * buffers in the window of the port getting previously closed - * and opening now. - */ - reclaim_consumed_buffers(port); - spin_unlock_irq(&port->outvq_lock); - - nonseekable_open(inode, filp); - - /* Notify host of port being opened */ - send_control_msg(filp->private_data, VIRTIO_CONSOLE_PORT_OPEN, 1); - - return 0; -out: - kref_put(&port->kref, remove_port); - return ret; -} - -static int port_fops_fasync(int fd, struct file *filp, int mode) -{ - struct port *port; - - port = filp->private_data; - return fasync_helper(fd, filp, mode, &port->async_queue); -} - -/* - * The file operations that we support: programs in the guest can open - * a console device, read from it, write to it, poll for data and - * close it. The devices are at - * /dev/vport<device number>p<port number> - */ -static const struct file_operations port_fops = { - .owner = THIS_MODULE, - .open = port_fops_open, - .read = port_fops_read, - .write = port_fops_write, - .poll = port_fops_poll, - .release = port_fops_release, - .fasync = port_fops_fasync, - .llseek = no_llseek, -}; - -/* - * The put_chars() callback is pretty straightforward. - * - * We turn the characters into a scatter-gather list, add it to the - * output queue and then kick the Host. Then we sit here waiting for - * it to finish: inefficient in theory, but in practice - * implementations will do it immediately (lguest's Launcher does). - */ -static int put_chars(u32 vtermno, const char *buf, int count) -{ - struct port *port; - - if (unlikely(early_put_chars)) - return early_put_chars(vtermno, buf, count); - - port = find_port_by_vtermno(vtermno); - if (!port) - return -EPIPE; - - return send_buf(port, (void *)buf, count, false); -} - -/* - * get_chars() is the callback from the hvc_console infrastructure - * when an interrupt is received. - * - * We call out to fill_readbuf that gets us the required data from the - * buffers that are queued up. - */ -static int get_chars(u32 vtermno, char *buf, int count) -{ - struct port *port; - - /* If we've not set up the port yet, we have no input to give. */ - if (unlikely(early_put_chars)) - return 0; - - port = find_port_by_vtermno(vtermno); - if (!port) - return -EPIPE; - - /* If we don't have an input queue yet, we can't get input. */ - BUG_ON(!port->in_vq); - - return fill_readbuf(port, buf, count, false); -} - -static void resize_console(struct port *port) -{ - struct virtio_device *vdev; - - /* The port could have been hot-unplugged */ - if (!port || !is_console_port(port)) - return; - - vdev = port->portdev->vdev; - if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_SIZE)) - hvc_resize(port->cons.hvc, port->cons.ws); -} - -/* We set the configuration at this point, since we now have a tty */ -static int notifier_add_vio(struct hvc_struct *hp, int data) -{ - struct port *port; - - port = find_port_by_vtermno(hp->vtermno); - if (!port) - return -EINVAL; - - hp->irq_requested = 1; - resize_console(port); - - return 0; -} - -static void notifier_del_vio(struct hvc_struct *hp, int data) -{ - hp->irq_requested = 0; -} - -/* The operations for console ports. */ -static const struct hv_ops hv_ops = { - .get_chars = get_chars, - .put_chars = put_chars, - .notifier_add = notifier_add_vio, - .notifier_del = notifier_del_vio, - .notifier_hangup = notifier_del_vio, -}; - -/* - * Console drivers are initialized very early so boot messages can go - * out, so we do things slightly differently from the generic virtio - * initialization of the net and block drivers. - * - * At this stage, the console is output-only. It's too early to set - * up a virtqueue, so we let the drivers do some boutique early-output - * thing. - */ -int __init virtio_cons_early_init(int (*put_chars)(u32, const char *, int)) -{ - early_put_chars = put_chars; - return hvc_instantiate(0, 0, &hv_ops); -} - -int init_port_console(struct port *port) -{ - int ret; - - /* - * The Host's telling us this port is a console port. Hook it - * up with an hvc console. - * - * To set up and manage our virtual console, we call - * hvc_alloc(). - * - * The first argument of hvc_alloc() is the virtual console - * number. The second argument is the parameter for the - * notification mechanism (like irq number). We currently - * leave this as zero, virtqueues have implicit notifications. - * - * The third argument is a "struct hv_ops" containing the - * put_chars() get_chars(), notifier_add() and notifier_del() - * pointers. The final argument is the output buffer size: we - * can do any size, so we put PAGE_SIZE here. - */ - port->cons.vtermno = pdrvdata.next_vtermno; - - port->cons.hvc = hvc_alloc(port->cons.vtermno, 0, &hv_ops, PAGE_SIZE); - if (IS_ERR(port->cons.hvc)) { - ret = PTR_ERR(port->cons.hvc); - dev_err(port->dev, - "error %d allocating hvc for port\n", ret); - port->cons.hvc = NULL; - return ret; - } - spin_lock_irq(&pdrvdata_lock); - pdrvdata.next_vtermno++; - list_add_tail(&port->cons.list, &pdrvdata.consoles); - spin_unlock_irq(&pdrvdata_lock); - port->guest_connected = true; - - /* - * Start using the new console output if this is the first - * console to come up. - */ - if (early_put_chars) - early_put_chars = NULL; - - /* Notify host of port being opened */ - send_control_msg(port, VIRTIO_CONSOLE_PORT_OPEN, 1); - - return 0; -} - -static ssize_t show_port_name(struct device *dev, - struct device_attribute *attr, char *buffer) -{ - struct port *port; - - port = dev_get_drvdata(dev); - - return sprintf(buffer, "%s\n", port->name); -} - -static DEVICE_ATTR(name, S_IRUGO, show_port_name, NULL); - -static struct attribute *port_sysfs_entries[] = { - &dev_attr_name.attr, - NULL -}; - -static struct attribute_group port_attribute_group = { - .name = NULL, /* put in device directory */ - .attrs = port_sysfs_entries, -}; - -static int debugfs_open(struct inode *inode, struct file *filp) -{ - filp->private_data = inode->i_private; - return 0; -} - -static ssize_t debugfs_read(struct file *filp, char __user *ubuf, - size_t count, loff_t *offp) -{ - struct port *port; - char *buf; - ssize_t ret, out_offset, out_count; - - out_count = 1024; - buf = kmalloc(out_count, GFP_KERNEL); - if (!buf) - return -ENOMEM; - - port = filp->private_data; - out_offset = 0; - out_offset += snprintf(buf + out_offset, out_count, - "name: %s\n", port->name ? port->name : ""); - out_offset += snprintf(buf + out_offset, out_count - out_offset, - "guest_connected: %d\n", port->guest_connected); - out_offset += snprintf(buf + out_offset, out_count - out_offset, - "host_connected: %d\n", port->host_connected); - out_offset += snprintf(buf + out_offset, out_count - out_offset, - "outvq_full: %d\n", port->outvq_full); - out_offset += snprintf(buf + out_offset, out_count - out_offset, - "is_console: %s\n", - is_console_port(port) ? "yes" : "no"); - out_offset += snprintf(buf + out_offset, out_count - out_offset, - "console_vtermno: %u\n", port->cons.vtermno); - - ret = simple_read_from_buffer(ubuf, count, offp, buf, out_offset); - kfree(buf); - return ret; -} - -static const struct file_operations port_debugfs_ops = { - .owner = THIS_MODULE, - .open = debugfs_open, - .read = debugfs_read, -}; - -static void set_console_size(struct port *port, u16 rows, u16 cols) -{ - if (!port || !is_console_port(port)) - return; - - port->cons.ws.ws_row = rows; - port->cons.ws.ws_col = cols; -} - -static unsigned int fill_queue(struct virtqueue *vq, spinlock_t *lock) -{ - struct port_buffer *buf; - unsigned int nr_added_bufs; - int ret; - - nr_added_bufs = 0; - do { - buf = alloc_buf(PAGE_SIZE); - if (!buf) - break; - - spin_lock_irq(lock); - ret = add_inbuf(vq, buf); - if (ret < 0) { - spin_unlock_irq(lock); - free_buf(buf); - break; - } - nr_added_bufs++; - spin_unlock_irq(lock); - } while (ret > 0); - - return nr_added_bufs; -} - -static void send_sigio_to_port(struct port *port) -{ - if (port->async_queue && port->guest_connected) - kill_fasync(&port->async_queue, SIGIO, POLL_OUT); -} - -static int add_port(struct ports_device *portdev, u32 id) -{ - char debugfs_name[16]; - struct port *port; - struct port_buffer *buf; - dev_t devt; - unsigned int nr_added_bufs; - int err; - - port = kmalloc(sizeof(*port), GFP_KERNEL); - if (!port) { - err = -ENOMEM; - goto fail; - } - kref_init(&port->kref); - - port->portdev = portdev; - port->id = id; - - port->name = NULL; - port->inbuf = NULL; - port->cons.hvc = NULL; - port->async_queue = NULL; - - port->cons.ws.ws_row = port->cons.ws.ws_col = 0; - - port->host_connected = port->guest_connected = false; - - port->outvq_full = false; - - port->in_vq = portdev->in_vqs[port->id]; - port->out_vq = portdev->out_vqs[port->id]; - - port->cdev = cdev_alloc(); - if (!port->cdev) { - dev_err(&port->portdev->vdev->dev, "Error allocating cdev\n"); - err = -ENOMEM; - goto free_port; - } - port->cdev->ops = &port_fops; - - devt = MKDEV(portdev->chr_major, id); - err = cdev_add(port->cdev, devt, 1); - if (err < 0) { - dev_err(&port->portdev->vdev->dev, - "Error %d adding cdev for port %u\n", err, id); - goto free_cdev; - } - port->dev = device_create(pdrvdata.class, &port->portdev->vdev->dev, - devt, port, "vport%up%u", - port->portdev->drv_index, id); - if (IS_ERR(port->dev)) { - err = PTR_ERR(port->dev); - dev_err(&port->portdev->vdev->dev, - "Error %d creating device for port %u\n", - err, id); - goto free_cdev; - } - - spin_lock_init(&port->inbuf_lock); - spin_lock_init(&port->outvq_lock); - init_waitqueue_head(&port->waitqueue); - - /* Fill the in_vq with buffers so the host can send us data. */ - nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); - if (!nr_added_bufs) { - dev_err(port->dev, "Error allocating inbufs\n"); - err = -ENOMEM; - goto free_device; - } - - /* - * If we're not using multiport support, this has to be a console port - */ - if (!use_multiport(port->portdev)) { - err = init_port_console(port); - if (err) - goto free_inbufs; - } - - spin_lock_irq(&portdev->ports_lock); - list_add_tail(&port->list, &port->portdev->ports); - spin_unlock_irq(&portdev->ports_lock); - - /* - * Tell the Host we're set so that it can send us various - * configuration parameters for this port (eg, port name, - * caching, whether this is a console port, etc.) - */ - send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); - - if (pdrvdata.debugfs_dir) { - /* - * Finally, create the debugfs file that we can use to - * inspect a port's state at any time - */ - sprintf(debugfs_name, "vport%up%u", - port->portdev->drv_index, id); - port->debugfs_file = debugfs_create_file(debugfs_name, 0444, - pdrvdata.debugfs_dir, - port, - &port_debugfs_ops); - } - return 0; - -free_inbufs: - while ((buf = virtqueue_detach_unused_buf(port->in_vq))) - free_buf(buf); -free_device: - device_destroy(pdrvdata.class, port->dev->devt); -free_cdev: - cdev_del(port->cdev); -free_port: - kfree(port); -fail: - /* The host might want to notify management sw about port add failure */ - __send_control_msg(portdev, id, VIRTIO_CONSOLE_PORT_READY, 0); - return err; -} - -/* No users remain, remove all port-specific data. */ -static void remove_port(struct kref *kref) -{ - struct port *port; - - port = container_of(kref, struct port, kref); - - sysfs_remove_group(&port->dev->kobj, &port_attribute_group); - device_destroy(pdrvdata.class, port->dev->devt); - cdev_del(port->cdev); - - kfree(port->name); - - debugfs_remove(port->debugfs_file); - - kfree(port); -} - -/* - * Port got unplugged. Remove port from portdev's list and drop the - * kref reference. If no userspace has this port opened, it will - * result in immediate removal the port. - */ -static void unplug_port(struct port *port) -{ - struct port_buffer *buf; - - spin_lock_irq(&port->portdev->ports_lock); - list_del(&port->list); - spin_unlock_irq(&port->portdev->ports_lock); - - if (port->guest_connected) { - port->guest_connected = false; - port->host_connected = false; - wake_up_interruptible(&port->waitqueue); - - /* Let the app know the port is going down. */ - send_sigio_to_port(port); - } - - if (is_console_port(port)) { - spin_lock_irq(&pdrvdata_lock); - list_del(&port->cons.list); - spin_unlock_irq(&pdrvdata_lock); -#if 0 - /* - * hvc_remove() not called as removing one hvc port - * results in other hvc ports getting frozen. - * - * Once this is resolved in hvc, this functionality - * will be enabled. Till that is done, the -EPIPE - * return from get_chars() above will help - * hvc_console.c to clean up on ports we remove here. - */ - hvc_remove(port->cons.hvc); -#endif - } - - /* Remove unused data this port might have received. */ - discard_port_data(port); - - reclaim_consumed_buffers(port); - - /* Remove buffers we queued up for the Host to send us data in. */ - while ((buf = virtqueue_detach_unused_buf(port->in_vq))) - free_buf(buf); - - /* - * We should just assume the device itself has gone off -- - * else a close on an open port later will try to send out a - * control message. - */ - port->portdev = NULL; - - /* - * Locks around here are not necessary - a port can't be - * opened after we removed the port struct from ports_list - * above. - */ - kref_put(&port->kref, remove_port); -} - -/* Any private messages that the Host and Guest want to share */ -static void handle_control_message(struct ports_device *portdev, - struct port_buffer *buf) -{ - struct virtio_console_control *cpkt; - struct port *port; - size_t name_size; - int err; - - cpkt = (struct virtio_console_control *)(buf->buf + buf->offset); - - port = find_port_by_id(portdev, cpkt->id); - if (!port && cpkt->event != VIRTIO_CONSOLE_PORT_ADD) { - /* No valid header at start of buffer. Drop it. */ - dev_dbg(&portdev->vdev->dev, - "Invalid index %u in control packet\n", cpkt->id); - return; - } - - switch (cpkt->event) { - case VIRTIO_CONSOLE_PORT_ADD: - if (port) { - dev_dbg(&portdev->vdev->dev, - "Port %u already added\n", port->id); - send_control_msg(port, VIRTIO_CONSOLE_PORT_READY, 1); - break; - } - if (cpkt->id >= portdev->config.max_nr_ports) { - dev_warn(&portdev->vdev->dev, - "Request for adding port with out-of-bound id %u, max. supported id: %u\n", - cpkt->id, portdev->config.max_nr_ports - 1); - break; - } - add_port(portdev, cpkt->id); - break; - case VIRTIO_CONSOLE_PORT_REMOVE: - unplug_port(port); - break; - case VIRTIO_CONSOLE_CONSOLE_PORT: - if (!cpkt->value) - break; - if (is_console_port(port)) - break; - - init_port_console(port); - /* - * Could remove the port here in case init fails - but - * have to notify the host first. - */ - break; - case VIRTIO_CONSOLE_RESIZE: { - struct { - __u16 rows; - __u16 cols; - } size; - - if (!is_console_port(port)) - break; - - memcpy(&size, buf->buf + buf->offset + sizeof(*cpkt), - sizeof(size)); - set_console_size(port, size.rows, size.cols); - - port->cons.hvc->irq_requested = 1; - resize_console(port); - break; - } - case VIRTIO_CONSOLE_PORT_OPEN: - port->host_connected = cpkt->value; - wake_up_interruptible(&port->waitqueue); - /* - * If the host port got closed and the host had any - * unconsumed buffers, we'll be able to reclaim them - * now. - */ - spin_lock_irq(&port->outvq_lock); - reclaim_consumed_buffers(port); - spin_unlock_irq(&port->outvq_lock); - - /* - * If the guest is connected, it'll be interested in - * knowing the host connection state changed. - */ - send_sigio_to_port(port); - break; - case VIRTIO_CONSOLE_PORT_NAME: - /* - * Skip the size of the header and the cpkt to get the size - * of the name that was sent - */ - name_size = buf->len - buf->offset - sizeof(*cpkt) + 1; - - port->name = kmalloc(name_size, GFP_KERNEL); - if (!port->name) { - dev_err(port->dev, - "Not enough space to store port name\n"); - break; - } - strncpy(port->name, buf->buf + buf->offset + sizeof(*cpkt), - name_size - 1); - port->name[name_size - 1] = 0; - - /* - * Since we only have one sysfs attribute, 'name', - * create it only if we have a name for the port. - */ - err = sysfs_create_group(&port->dev->kobj, - &port_attribute_group); - if (err) { - dev_err(port->dev, - "Error %d creating sysfs device attributes\n", - err); - } else { - /* - * Generate a udev event so that appropriate - * symlinks can be created based on udev - * rules. - */ - kobject_uevent(&port->dev->kobj, KOBJ_CHANGE); - } - break; - } -} - -static void control_work_handler(struct work_struct *work) -{ - struct ports_device *portdev; - struct virtqueue *vq; - struct port_buffer *buf; - unsigned int len; - - portdev = container_of(work, struct ports_device, control_work); - vq = portdev->c_ivq; - - spin_lock(&portdev->cvq_lock); - while ((buf = virtqueue_get_buf(vq, &len))) { - spin_unlock(&portdev->cvq_lock); - - buf->len = len; - buf->offset = 0; - - handle_control_message(portdev, buf); - - spin_lock(&portdev->cvq_lock); - if (add_inbuf(portdev->c_ivq, buf) < 0) { - dev_warn(&portdev->vdev->dev, - "Error adding buffer to queue\n"); - free_buf(buf); - } - } - spin_unlock(&portdev->cvq_lock); -} - -static void in_intr(struct virtqueue *vq) -{ - struct port *port; - unsigned long flags; - - port = find_port_by_vq(vq->vdev->priv, vq); - if (!port) - return; - - spin_lock_irqsave(&port->inbuf_lock, flags); - if (!port->inbuf) - port->inbuf = get_inbuf(port); - - /* - * Don't queue up data when port is closed. This condition - * can be reached when a console port is not yet connected (no - * tty is spawned) and the host sends out data to console - * ports. For generic serial ports, the host won't - * (shouldn't) send data till the guest is connected. - */ - if (!port->guest_connected) - discard_port_data(port); - - spin_unlock_irqrestore(&port->inbuf_lock, flags); - - wake_up_interruptible(&port->waitqueue); - - /* Send a SIGIO indicating new data in case the process asked for it */ - send_sigio_to_port(port); - - if (is_console_port(port) && hvc_poll(port->cons.hvc)) - hvc_kick(); -} - -static void control_intr(struct virtqueue *vq) -{ - struct ports_device *portdev; - - portdev = vq->vdev->priv; - schedule_work(&portdev->control_work); -} - -static void config_intr(struct virtio_device *vdev) -{ - struct ports_device *portdev; - - portdev = vdev->priv; - - if (!use_multiport(portdev)) { - struct port *port; - u16 rows, cols; - - vdev->config->get(vdev, - offsetof(struct virtio_console_config, cols), - &cols, sizeof(u16)); - vdev->config->get(vdev, - offsetof(struct virtio_console_config, rows), - &rows, sizeof(u16)); - - port = find_port_by_id(portdev, 0); - set_console_size(port, rows, cols); - - /* - * 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); - } -} - -static int init_vqs(struct ports_device *portdev) -{ - vq_callback_t **io_callbacks; - char **io_names; - struct virtqueue **vqs; - u32 i, j, nr_ports, nr_queues; - int err; - - nr_ports = portdev->config.max_nr_ports; - nr_queues = use_multiport(portdev) ? (nr_ports + 1) * 2 : 2; - - vqs = kmalloc(nr_queues * sizeof(struct virtqueue *), GFP_KERNEL); - io_callbacks = kmalloc(nr_queues * sizeof(vq_callback_t *), GFP_KERNEL); - io_names = kmalloc(nr_queues * sizeof(char *), GFP_KERNEL); - portdev->in_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *), - GFP_KERNEL); - portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *), - GFP_KERNEL); - if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs || - !portdev->out_vqs) { - err = -ENOMEM; - goto free; - } - - /* - * For backward compat (newer host but older guest), the host - * spawns a console port first and also inits the vqs for port - * 0 before others. - */ - j = 0; - io_callbacks[j] = in_intr; - io_callbacks[j + 1] = NULL; - io_names[j] = "input"; - io_names[j + 1] = "output"; - j += 2; - - if (use_multiport(portdev)) { - io_callbacks[j] = control_intr; - io_callbacks[j + 1] = NULL; - io_names[j] = "control-i"; - io_names[j + 1] = "control-o"; - - for (i = 1; i < nr_ports; i++) { - j += 2; - io_callbacks[j] = in_intr; - io_callbacks[j + 1] = NULL; - io_names[j] = "input"; - io_names[j + 1] = "output"; - } - } - /* Find the queues. */ - err = portdev->vdev->config->find_vqs(portdev->vdev, nr_queues, vqs, - io_callbacks, - (const char **)io_names); - if (err) - goto free; - - j = 0; - portdev->in_vqs[0] = vqs[0]; - portdev->out_vqs[0] = vqs[1]; - j += 2; - if (use_multiport(portdev)) { - portdev->c_ivq = vqs[j]; - portdev->c_ovq = vqs[j + 1]; - - for (i = 1; i < nr_ports; i++) { - j += 2; - portdev->in_vqs[i] = vqs[j]; - portdev->out_vqs[i] = vqs[j + 1]; - } - } - kfree(io_names); - kfree(io_callbacks); - kfree(vqs); - - return 0; - -free: - kfree(portdev->out_vqs); - kfree(portdev->in_vqs); - kfree(io_names); - kfree(io_callbacks); - kfree(vqs); - - return err; -} - -static const struct file_operations portdev_fops = { - .owner = THIS_MODULE, -}; - -/* - * Once we're further in boot, we get probed like any other virtio - * device. - * - * If the host also supports multiple console ports, we check the - * config space to see how many ports the host has spawned. We - * initialize each port found. - */ -static int __devinit virtcons_probe(struct virtio_device *vdev) -{ - struct ports_device *portdev; - int err; - bool multiport; - - portdev = kmalloc(sizeof(*portdev), GFP_KERNEL); - if (!portdev) { - err = -ENOMEM; - goto fail; - } - - /* Attach this portdev to this virtio_device, and vice-versa. */ - portdev->vdev = vdev; - vdev->priv = portdev; - - spin_lock_irq(&pdrvdata_lock); - portdev->drv_index = pdrvdata.index++; - spin_unlock_irq(&pdrvdata_lock); - - portdev->chr_major = register_chrdev(0, "virtio-portsdev", - &portdev_fops); - if (portdev->chr_major < 0) { - dev_err(&vdev->dev, - "Error %d registering chrdev for device %u\n", - portdev->chr_major, portdev->drv_index); - err = portdev->chr_major; - goto free; - } - - multiport = false; - portdev->config.max_nr_ports = 1; - if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) { - multiport = true; - vdev->features[0] |= 1 << VIRTIO_CONSOLE_F_MULTIPORT; - - vdev->config->get(vdev, offsetof(struct virtio_console_config, - max_nr_ports), - &portdev->config.max_nr_ports, - sizeof(portdev->config.max_nr_ports)); - } - - /* Let the Host know we support multiple ports.*/ - vdev->config->finalize_features(vdev); - - err = init_vqs(portdev); - if (err < 0) { - dev_err(&vdev->dev, "Error %d initializing vqs\n", err); - goto free_chrdev; - } - - spin_lock_init(&portdev->ports_lock); - INIT_LIST_HEAD(&portdev->ports); - - if (multiport) { - unsigned int nr_added_bufs; - - spin_lock_init(&portdev->cvq_lock); - INIT_WORK(&portdev->control_work, &control_work_handler); - - nr_added_bufs = fill_queue(portdev->c_ivq, &portdev->cvq_lock); - if (!nr_added_bufs) { - dev_err(&vdev->dev, - "Error allocating buffers for control queue\n"); - err = -ENOMEM; - goto free_vqs; - } - } else { - /* - * For backward compatibility: Create a console port - * if we're running on older host. - */ - add_port(portdev, 0); - } - - spin_lock_irq(&pdrvdata_lock); - list_add_tail(&portdev->list, &pdrvdata.portdevs); - spin_unlock_irq(&pdrvdata_lock); - - __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, - VIRTIO_CONSOLE_DEVICE_READY, 1); - return 0; - -free_vqs: - /* The host might want to notify mgmt sw about device add failure */ - __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, - VIRTIO_CONSOLE_DEVICE_READY, 0); - vdev->config->del_vqs(vdev); - kfree(portdev->in_vqs); - kfree(portdev->out_vqs); -free_chrdev: - unregister_chrdev(portdev->chr_major, "virtio-portsdev"); -free: - kfree(portdev); -fail: - return err; -} - -static void virtcons_remove(struct virtio_device *vdev) -{ - struct ports_device *portdev; - struct port *port, *port2; - - portdev = vdev->priv; - - spin_lock_irq(&pdrvdata_lock); - list_del(&portdev->list); - spin_unlock_irq(&pdrvdata_lock); - - /* Disable interrupts for vqs */ - vdev->config->reset(vdev); - /* Finish up work that's lined up */ - cancel_work_sync(&portdev->control_work); - - list_for_each_entry_safe(port, port2, &portdev->ports, list) - unplug_port(port); - - unregister_chrdev(portdev->chr_major, "virtio-portsdev"); - - /* - * When yanking out a device, we immediately lose the - * (device-side) queues. So there's no point in keeping the - * guest side around till we drop our final reference. This - * also means that any ports which are in an open state will - * have to just stop using the port, as the vqs are going - * away. - */ - if (use_multiport(portdev)) { - struct port_buffer *buf; - unsigned int len; - - while ((buf = virtqueue_get_buf(portdev->c_ivq, &len))) - free_buf(buf); - - while ((buf = virtqueue_detach_unused_buf(portdev->c_ivq))) - free_buf(buf); - } - - vdev->config->del_vqs(vdev); - kfree(portdev->in_vqs); - kfree(portdev->out_vqs); - - kfree(portdev); -} - -static struct virtio_device_id id_table[] = { - { VIRTIO_ID_CONSOLE, VIRTIO_DEV_ANY_ID }, - { 0 }, -}; - -static unsigned int features[] = { - VIRTIO_CONSOLE_F_SIZE, - VIRTIO_CONSOLE_F_MULTIPORT, -}; - -static struct virtio_driver virtio_console = { - .feature_table = features, - .feature_table_size = ARRAY_SIZE(features), - .driver.name = KBUILD_MODNAME, - .driver.owner = THIS_MODULE, - .id_table = id_table, - .probe = virtcons_probe, - .remove = virtcons_remove, - .config_changed = config_intr, -}; - -static int __init init(void) -{ - int err; - - pdrvdata.class = class_create(THIS_MODULE, "virtio-ports"); - if (IS_ERR(pdrvdata.class)) { - err = PTR_ERR(pdrvdata.class); - pr_err("Error %d creating virtio-ports class\n", err); - return err; - } - - pdrvdata.debugfs_dir = debugfs_create_dir("virtio-ports", NULL); - if (!pdrvdata.debugfs_dir) { - pr_warning("Error %ld creating debugfs dir for virtio-ports\n", - PTR_ERR(pdrvdata.debugfs_dir)); - } - INIT_LIST_HEAD(&pdrvdata.consoles); - INIT_LIST_HEAD(&pdrvdata.portdevs); - - return register_virtio_driver(&virtio_console); -} - -static void __exit fini(void) -{ - unregister_virtio_driver(&virtio_console); - - class_destroy(pdrvdata.class); - if (pdrvdata.debugfs_dir) - debugfs_remove_recursive(pdrvdata.debugfs_dir); -} -module_init(init); -module_exit(fini); - -MODULE_DEVICE_TABLE(virtio, id_table); -MODULE_DESCRIPTION("Virtio console driver"); -MODULE_LICENSE("GPL"); |
