virtio: console: don't assume a single console port. (38edf58d) · Commits · 戴 / test

drivers/char/virtio_console.c

+65 −9

Original line number	Diff line number	Diff line
		@@ -17,10 +17,28 @@
		*/
		#include <linux/err.h>
		#include <linux/init.h>
		#include <linux/list.h>
		#include <linux/spinlock.h>
		#include <linux/virtio.h>
		#include <linux/virtio_console.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 {
		/* All the console devices handled by this driver */
		struct list_head consoles;
		};
		static struct ports_driver_data pdrvdata;

		DEFINE_SPINLOCK(pdrvdata_lock);

		struct port_buffer {
		char *buf;

		@@ -40,8 +58,15 @@ struct port {
		/* The current buffer from which data has to be fed to readers */
		struct port_buffer *inbuf;

		/* For console ports, hvc != NULL and these are valid. */
		/* The hvc device */
		struct hvc_struct *hvc;

		/* We'll place all consoles in a list in the pdrvdata struct */
		struct list_head list;

		/* Our vterm number. */
		u32 vtermno;
		};

		/* We have one port ready to go immediately, for a console. */
		@@ -50,6 +75,22 @@ static struct port console;
		/* 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;
		unsigned long flags;

		spin_lock_irqsave(&pdrvdata_lock, flags);
		list_for_each_entry(port, &pdrvdata.consoles, list) {
		if (port->vtermno == vtermno)
		goto out;
		}
		port = NULL;
		out:
		spin_unlock_irqrestore(&pdrvdata_lock, flags);
		return port;
		}

		static void free_buf(struct port_buffer *buf)
		{
		kfree(buf->buf);
		@@ -120,14 +161,16 @@ static void add_inbuf(struct virtqueue vq, struct port_buffer buf)
		static int put_chars(u32 vtermno, const char *buf, int count)
		{
		struct scatterlist sg[1];
		unsigned int len;
		struct port *port;
		unsigned int len;

		port = find_port_by_vtermno(vtermno);
		if (!port)
		return 0;

		if (unlikely(early_put_chars))
		return early_put_chars(vtermno, buf, count);

		port = &console;

		/* This is a convenient routine to initialize a single-elem sg list */
		sg_init_one(sg, buf, count);

		@@ -155,7 +198,10 @@ static int get_chars(u32 vtermno, char *buf, int count)
		{
		struct port *port;

		port = &console;

		port = find_port_by_vtermno(vtermno);
		if (!port)
		return 0;

		/* If we don't have an input queue yet, we can't get input. */
		BUG_ON(!port->in_vq);
		@@ -201,14 +247,17 @@ static void virtcons_apply_config(struct virtio_device *dev)
		}
		}

		/*
		* we support only one console, the hvc struct is a global var We set
		* the configuration at this point, since we now have a tty
		*/
		/* 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;
		virtcons_apply_config(console.vdev);
		virtcons_apply_config(port->vdev);

		return 0;
		}
		@@ -313,6 +362,11 @@ static int __devinit virtcons_probe(struct virtio_device *vdev)
		goto free_vqs;
		}

		/* Add to vtermno list. */
		spin_lock_irq(&pdrvdata_lock);
		list_add(&port->list, &pdrvdata.consoles);
		spin_unlock_irq(&pdrvdata_lock);

		/* Register the input buffer the first time. */
		add_inbuf(port->in_vq, port->inbuf);

		@@ -349,6 +403,8 @@ static struct virtio_driver virtio_console = {

		static int __init init(void)
		{
		INIT_LIST_HEAD(&pdrvdata.consoles);

		return register_virtio_driver(&virtio_console);
		}
		module_init(init);

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