diff options
Diffstat (limited to 'drivers/char/virtio_console.c')
| -rw-r--r-- | drivers/char/virtio_console.c | 121 |
1 files changed, 80 insertions, 41 deletions
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index fb68b1295373..8e3c46d67cb3 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -19,8 +19,10 @@ */ #include <linux/cdev.h> #include <linux/debugfs.h> +#include <linux/completion.h> #include <linux/device.h> #include <linux/err.h> +#include <linux/freezer.h> #include <linux/fs.h> #include <linux/init.h> #include <linux/list.h> @@ -32,6 +34,7 @@ #include <linux/virtio_console.h> #include <linux/wait.h> #include <linux/workqueue.h> +#include <linux/module.h> #include "../tty/hvc/hvc_console.h" /* @@ -73,6 +76,7 @@ struct ports_driver_data { static struct ports_driver_data pdrvdata; DEFINE_SPINLOCK(pdrvdata_lock); +DECLARE_COMPLETION(early_console_added); /* This struct holds information that's relevant only for console ports */ struct console { @@ -151,6 +155,10 @@ struct ports_device { int chr_major; }; +struct port_stats { + unsigned long bytes_sent, bytes_received, bytes_discarded; +}; + /* This struct holds the per-port data */ struct port { /* Next port in the list, head is in the ports_device */ @@ -179,6 +187,13 @@ struct port { struct dentry *debugfs_file; /* + * Keep count of the bytes sent, received and discarded for + * this port for accounting and debugging purposes. These + * counts are not reset across port open / close events. + */ + struct port_stats stats; + + /* * The entries in this struct will be valid if this port is * hooked up to an hvc console */ @@ -347,17 +362,19 @@ fail: } /* Callers should take appropriate locks */ -static void *get_inbuf(struct port *port) +static struct port_buffer *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 (port->inbuf) + return port->inbuf; + + buf = virtqueue_get_buf(port->in_vq, &len); if (buf) { buf->len = len; buf->offset = 0; + port->stats.bytes_received += len; } return buf; } @@ -384,32 +401,27 @@ static int add_inbuf(struct virtqueue *vq, struct port_buffer *buf) static void discard_port_data(struct port *port) { struct port_buffer *buf; - struct virtqueue *vq; - unsigned int len; - int ret; + unsigned int err; if (!port->portdev) { /* Device has been unplugged. vqs are already gone. */ return; } - vq = port->in_vq; - if (port->inbuf) - buf = port->inbuf; - else - buf = virtqueue_get_buf(vq, &len); + buf = get_inbuf(port); - ret = 0; + err = 0; while (buf) { - if (add_inbuf(vq, buf) < 0) { - ret++; + port->stats.bytes_discarded += buf->len - buf->offset; + if (add_inbuf(port->in_vq, buf) < 0) { + err++; free_buf(buf); } - buf = virtqueue_get_buf(vq, &len); + port->inbuf = NULL; + buf = get_inbuf(port); } - port->inbuf = NULL; - if (ret) + if (err) dev_warn(port->dev, "Errors adding %d buffers back to vq\n", - ret); + err); } static bool port_has_data(struct port *port) @@ -417,18 +429,12 @@ static bool port_has_data(struct port *port) unsigned long flags; bool ret; + ret = false; spin_lock_irqsave(&port->inbuf_lock, flags); - if (port->inbuf) { - ret = true; - goto out; - } port->inbuf = get_inbuf(port); - if (port->inbuf) { + if (port->inbuf) ret = true; - goto out; - } - ret = false; -out: + spin_unlock_irqrestore(&port->inbuf_lock, flags); return ret; } @@ -529,6 +535,8 @@ static ssize_t send_buf(struct port *port, void *in_buf, size_t in_count, cpu_relax(); done: spin_unlock_irqrestore(&port->outvq_lock, flags); + + port->stats.bytes_sent += in_count; /* * We're expected to return the amount of data we wrote -- all * of it @@ -633,8 +641,8 @@ static ssize_t port_fops_read(struct file *filp, char __user *ubuf, if (filp->f_flags & O_NONBLOCK) return -EAGAIN; - ret = wait_event_interruptible(port->waitqueue, - !will_read_block(port)); + ret = wait_event_freezable(port->waitqueue, + !will_read_block(port)); if (ret < 0) return ret; } @@ -677,8 +685,8 @@ static ssize_t port_fops_write(struct file *filp, const char __user *ubuf, if (nonblock) return -EAGAIN; - ret = wait_event_interruptible(port->waitqueue, - !will_write_block(port)); + ret = wait_event_freezable(port->waitqueue, + !will_write_block(port)); if (ret < 0) return ret; } @@ -1059,6 +1067,14 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf, 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, + "bytes_sent: %lu\n", port->stats.bytes_sent); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "bytes_received: %lu\n", + port->stats.bytes_received); + out_offset += snprintf(buf + out_offset, out_count - out_offset, + "bytes_discarded: %lu\n", + port->stats.bytes_discarded); + 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, @@ -1143,6 +1159,7 @@ static int add_port(struct ports_device *portdev, u32 id) port->cons.ws.ws_row = port->cons.ws.ws_col = 0; port->host_connected = port->guest_connected = false; + port->stats = (struct port_stats) { 0 }; port->outvq_full = false; @@ -1352,6 +1369,7 @@ static void handle_control_message(struct ports_device *portdev, break; init_port_console(port); + complete(&early_console_added); /* * Could remove the port here in case init fails - but * have to notify the host first. @@ -1394,6 +1412,13 @@ static void handle_control_message(struct ports_device *portdev, break; case VIRTIO_CONSOLE_PORT_NAME: /* + * If we woke up after hibernation, we can get this + * again. Skip it in that case. + */ + if (port->name) + break; + + /* * Skip the size of the header and the cpkt to get the size * of the name that was sent */ @@ -1481,8 +1506,7 @@ static void in_intr(struct virtqueue *vq) return; spin_lock_irqsave(&port->inbuf_lock, flags); - if (!port->inbuf) - port->inbuf = get_inbuf(port); + port->inbuf = get_inbuf(port); /* * Don't queue up data when port is closed. This condition @@ -1563,7 +1587,7 @@ static int init_vqs(struct ports_device *portdev) portdev->out_vqs = kmalloc(nr_ports * sizeof(struct virtqueue *), GFP_KERNEL); if (!vqs || !io_callbacks || !io_names || !portdev->in_vqs || - !portdev->out_vqs) { + !portdev->out_vqs) { err = -ENOMEM; goto free; } @@ -1648,6 +1672,10 @@ static int __devinit virtcons_probe(struct virtio_device *vdev) struct ports_device *portdev; int err; bool multiport; + bool early = early_put_chars != NULL; + + /* Ensure to read early_put_chars now */ + barrier(); portdev = kmalloc(sizeof(*portdev), GFP_KERNEL); if (!portdev) { @@ -1675,13 +1703,11 @@ static int __devinit virtcons_probe(struct virtio_device *vdev) multiport = false; portdev->config.max_nr_ports = 1; - if (virtio_has_feature(vdev, VIRTIO_CONSOLE_F_MULTIPORT)) { + if (virtio_config_val(vdev, VIRTIO_CONSOLE_F_MULTIPORT, + offsetof(struct virtio_console_config, + max_nr_ports), + &portdev->config.max_nr_ports) == 0) multiport = true; - vdev->config->get(vdev, offsetof(struct virtio_console_config, - max_nr_ports), - &portdev->config.max_nr_ports, - sizeof(portdev->config.max_nr_ports)); - } err = init_vqs(portdev); if (err < 0) { @@ -1719,6 +1745,19 @@ static int __devinit virtcons_probe(struct virtio_device *vdev) __send_control_msg(portdev, VIRTIO_CONSOLE_BAD_ID, VIRTIO_CONSOLE_DEVICE_READY, 1); + + /* + * If there was an early virtio console, assume that there are no + * other consoles. We need to wait until the hvc_alloc matches the + * hvc_instantiate, otherwise tty_open will complain, resulting in + * a "Warning: unable to open an initial console" boot failure. + * Without multiport this is done in add_port above. With multiport + * this might take some host<->guest communication - thus we have to + * wait. + */ + if (multiport && early) + wait_for_completion(&early_console_added); + return 0; free_vqs: |