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path: root/drivers/input/serio/serio_raw.c
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Diffstat (limited to 'drivers/input/serio/serio_raw.c')
-rw-r--r--drivers/input/serio/serio_raw.c215
1 files changed, 125 insertions, 90 deletions
diff --git a/drivers/input/serio/serio_raw.c b/drivers/input/serio/serio_raw.c
index b7ba459..4d4cd14 100644
--- a/drivers/input/serio/serio_raw.c
+++ b/drivers/input/serio/serio_raw.c
@@ -9,6 +9,7 @@
* the Free Software Foundation.
*/
+#include <linux/kref.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/poll.h>
@@ -33,15 +34,16 @@ struct serio_raw {
unsigned int tail, head;
char name[16];
- unsigned int refcnt;
+ struct kref kref;
struct serio *serio;
struct miscdevice dev;
wait_queue_head_t wait;
- struct list_head list;
+ struct list_head client_list;
struct list_head node;
+ bool dead;
};
-struct serio_raw_list {
+struct serio_raw_client {
struct fasync_struct *fasync;
struct serio_raw *serio_raw;
struct list_head node;
@@ -49,7 +51,6 @@ struct serio_raw_list {
static DEFINE_MUTEX(serio_raw_mutex);
static LIST_HEAD(serio_raw_list);
-static unsigned int serio_raw_no;
/*********************************************************************
* Interface with userspace (file operations) *
@@ -57,9 +58,9 @@ static unsigned int serio_raw_no;
static int serio_raw_fasync(int fd, struct file *file, int on)
{
- struct serio_raw_list *list = file->private_data;
+ struct serio_raw_client *client = file->private_data;
- return fasync_helper(fd, file, on, &list->fasync);
+ return fasync_helper(fd, file, on, &client->fasync);
}
static struct serio_raw *serio_raw_locate(int minor)
@@ -77,8 +78,8 @@ static struct serio_raw *serio_raw_locate(int minor)
static int serio_raw_open(struct inode *inode, struct file *file)
{
struct serio_raw *serio_raw;
- struct serio_raw_list *list;
- int retval = 0;
+ struct serio_raw_client *client;
+ int retval;
retval = mutex_lock_interruptible(&serio_raw_mutex);
if (retval)
@@ -90,60 +91,61 @@ static int serio_raw_open(struct inode *inode, struct file *file)
goto out;
}
- if (!serio_raw->serio) {
+ if (serio_raw->dead) {
retval = -ENODEV;
goto out;
}
- list = kzalloc(sizeof(struct serio_raw_list), GFP_KERNEL);
- if (!list) {
+ client = kzalloc(sizeof(struct serio_raw_client), GFP_KERNEL);
+ if (!client) {
retval = -ENOMEM;
goto out;
}
- list->serio_raw = serio_raw;
- file->private_data = list;
+ client->serio_raw = serio_raw;
+ file->private_data = client;
+
+ kref_get(&serio_raw->kref);
- serio_raw->refcnt++;
- list_add_tail(&list->node, &serio_raw->list);
+ serio_pause_rx(serio_raw->serio);
+ list_add_tail(&client->node, &serio_raw->client_list);
+ serio_continue_rx(serio_raw->serio);
out:
mutex_unlock(&serio_raw_mutex);
return retval;
}
-static int serio_raw_cleanup(struct serio_raw *serio_raw)
+static void serio_raw_free(struct kref *kref)
{
- if (--serio_raw->refcnt == 0) {
- misc_deregister(&serio_raw->dev);
- list_del_init(&serio_raw->node);
- kfree(serio_raw);
+ struct serio_raw *serio_raw =
+ container_of(kref, struct serio_raw, kref);
- return 1;
- }
-
- return 0;
+ put_device(&serio_raw->serio->dev);
+ kfree(serio_raw);
}
static int serio_raw_release(struct inode *inode, struct file *file)
{
- struct serio_raw_list *list = file->private_data;
- struct serio_raw *serio_raw = list->serio_raw;
+ struct serio_raw_client *client = file->private_data;
+ struct serio_raw *serio_raw = client->serio_raw;
- mutex_lock(&serio_raw_mutex);
+ serio_pause_rx(serio_raw->serio);
+ list_del(&client->node);
+ serio_continue_rx(serio_raw->serio);
- serio_raw_cleanup(serio_raw);
+ kfree(client);
+
+ kref_put(&serio_raw->kref, serio_raw_free);
- mutex_unlock(&serio_raw_mutex);
return 0;
}
-static int serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c)
+static bool serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c)
{
- unsigned long flags;
- int empty;
+ bool empty;
- spin_lock_irqsave(&serio_raw->serio->lock, flags);
+ serio_pause_rx(serio_raw->serio);
empty = serio_raw->head == serio_raw->tail;
if (!empty) {
@@ -151,30 +153,31 @@ static int serio_raw_fetch_byte(struct serio_raw *serio_raw, char *c)
serio_raw->tail = (serio_raw->tail + 1) % SERIO_RAW_QUEUE_LEN;
}
- spin_unlock_irqrestore(&serio_raw->serio->lock, flags);
+ serio_continue_rx(serio_raw->serio);
return !empty;
}
-static ssize_t serio_raw_read(struct file *file, char __user *buffer, size_t count, loff_t *ppos)
+static ssize_t serio_raw_read(struct file *file, char __user *buffer,
+ size_t count, loff_t *ppos)
{
- struct serio_raw_list *list = file->private_data;
- struct serio_raw *serio_raw = list->serio_raw;
+ struct serio_raw_client *client = file->private_data;
+ struct serio_raw *serio_raw = client->serio_raw;
char uninitialized_var(c);
ssize_t retval = 0;
- if (!serio_raw->serio)
+ if (serio_raw->dead)
return -ENODEV;
if (serio_raw->head == serio_raw->tail && (file->f_flags & O_NONBLOCK))
return -EAGAIN;
- retval = wait_event_interruptible(list->serio_raw->wait,
- serio_raw->head != serio_raw->tail || !serio_raw->serio);
+ retval = wait_event_interruptible(serio_raw->wait,
+ serio_raw->head != serio_raw->tail || serio_raw->dead);
if (retval)
return retval;
- if (!serio_raw->serio)
+ if (serio_raw->dead)
return -ENODEV;
while (retval < count && serio_raw_fetch_byte(serio_raw, &c)) {
@@ -186,9 +189,11 @@ static ssize_t serio_raw_read(struct file *file, char __user *buffer, size_t cou
return retval;
}
-static ssize_t serio_raw_write(struct file *file, const char __user *buffer, size_t count, loff_t *ppos)
+static ssize_t serio_raw_write(struct file *file, const char __user *buffer,
+ size_t count, loff_t *ppos)
{
- struct serio_raw_list *list = file->private_data;
+ struct serio_raw_client *client = file->private_data;
+ struct serio_raw *serio_raw = client->serio_raw;
ssize_t written = 0;
int retval;
unsigned char c;
@@ -197,7 +202,7 @@ static ssize_t serio_raw_write(struct file *file, const char __user *buffer, siz
if (retval)
return retval;
- if (!list->serio_raw->serio) {
+ if (serio_raw->dead) {
retval = -ENODEV;
goto out;
}
@@ -210,7 +215,7 @@ static ssize_t serio_raw_write(struct file *file, const char __user *buffer, siz
retval = -EFAULT;
goto out;
}
- if (serio_write(list->serio_raw->serio, c)) {
+ if (serio_write(serio_raw->serio, c)) {
retval = -EIO;
goto out;
}
@@ -224,46 +229,49 @@ out:
static unsigned int serio_raw_poll(struct file *file, poll_table *wait)
{
- struct serio_raw_list *list = file->private_data;
+ struct serio_raw_client *client = file->private_data;
+ struct serio_raw *serio_raw = client->serio_raw;
+ unsigned int mask;
- poll_wait(file, &list->serio_raw->wait, wait);
+ poll_wait(file, &serio_raw->wait, wait);
- if (list->serio_raw->head != list->serio_raw->tail)
+ mask = serio_raw->dead ? POLLHUP | POLLERR : POLLOUT | POLLWRNORM;
+ if (serio_raw->head != serio_raw->tail)
return POLLIN | POLLRDNORM;
return 0;
}
static const struct file_operations serio_raw_fops = {
- .owner = THIS_MODULE,
- .open = serio_raw_open,
- .release = serio_raw_release,
- .read = serio_raw_read,
- .write = serio_raw_write,
- .poll = serio_raw_poll,
- .fasync = serio_raw_fasync,
- .llseek = noop_llseek,
+ .owner = THIS_MODULE,
+ .open = serio_raw_open,
+ .release = serio_raw_release,
+ .read = serio_raw_read,
+ .write = serio_raw_write,
+ .poll = serio_raw_poll,
+ .fasync = serio_raw_fasync,
+ .llseek = noop_llseek,
};
/*********************************************************************
- * Interface with serio port *
+ * Interface with serio port *
*********************************************************************/
static irqreturn_t serio_raw_interrupt(struct serio *serio, unsigned char data,
unsigned int dfl)
{
struct serio_raw *serio_raw = serio_get_drvdata(serio);
- struct serio_raw_list *list;
+ struct serio_raw_client *client;
unsigned int head = serio_raw->head;
- /* we are holding serio->lock here so we are prootected */
+ /* we are holding serio->lock here so we are protected */
serio_raw->queue[head] = data;
head = (head + 1) % SERIO_RAW_QUEUE_LEN;
if (likely(head != serio_raw->tail)) {
serio_raw->head = head;
- list_for_each_entry(list, &serio_raw->list, node)
- kill_fasync(&list->fasync, SIGIO, POLL_IN);
+ list_for_each_entry(client, &serio_raw->client_list, node)
+ kill_fasync(&client->fasync, SIGIO, POLL_IN);
wake_up_interruptible(&serio_raw->wait);
}
@@ -272,29 +280,37 @@ static irqreturn_t serio_raw_interrupt(struct serio *serio, unsigned char data,
static int serio_raw_connect(struct serio *serio, struct serio_driver *drv)
{
+ static atomic_t serio_raw_no = ATOMIC_INIT(0);
struct serio_raw *serio_raw;
int err;
- if (!(serio_raw = kzalloc(sizeof(struct serio_raw), GFP_KERNEL))) {
- printk(KERN_ERR "serio_raw.c: can't allocate memory for a device\n");
+ serio_raw = kzalloc(sizeof(struct serio_raw), GFP_KERNEL);
+ if (!serio_raw) {
+ dev_dbg(&serio->dev, "can't allocate memory for a device\n");
return -ENOMEM;
}
- mutex_lock(&serio_raw_mutex);
+ snprintf(serio_raw->name, sizeof(serio_raw->name),
+ "serio_raw%ld", (long)atomic_inc_return(&serio_raw_no) - 1);
+ kref_init(&serio_raw->kref);
+ INIT_LIST_HEAD(&serio_raw->client_list);
+ init_waitqueue_head(&serio_raw->wait);
- snprintf(serio_raw->name, sizeof(serio_raw->name), "serio_raw%d", serio_raw_no++);
- serio_raw->refcnt = 1;
serio_raw->serio = serio;
- INIT_LIST_HEAD(&serio_raw->list);
- init_waitqueue_head(&serio_raw->wait);
+ get_device(&serio->dev);
serio_set_drvdata(serio, serio_raw);
err = serio_open(serio, drv);
if (err)
- goto out_free;
+ goto err_free;
+
+ err = mutex_lock_killable(&serio_raw_mutex);
+ if (err)
+ goto err_close;
list_add_tail(&serio_raw->node, &serio_raw_list);
+ mutex_unlock(&serio_raw_mutex);
serio_raw->dev.minor = PSMOUSE_MINOR;
serio_raw->dev.name = serio_raw->name;
@@ -308,23 +324,23 @@ static int serio_raw_connect(struct serio *serio, struct serio_driver *drv)
}
if (err) {
- printk(KERN_INFO "serio_raw: failed to register raw access device for %s\n",
+ dev_err(&serio->dev,
+ "failed to register raw access device for %s\n",
serio->phys);
- goto out_close;
+ goto err_unlink;
}
- printk(KERN_INFO "serio_raw: raw access enabled on %s (%s, minor %d)\n",
- serio->phys, serio_raw->name, serio_raw->dev.minor);
- goto out;
+ dev_info(&serio->dev, "raw access enabled on %s (%s, minor %d)\n",
+ serio->phys, serio_raw->name, serio_raw->dev.minor);
+ return 0;
-out_close:
- serio_close(serio);
+err_unlink:
list_del_init(&serio_raw->node);
-out_free:
+err_close:
+ serio_close(serio);
+err_free:
serio_set_drvdata(serio, NULL);
- kfree(serio_raw);
-out:
- mutex_unlock(&serio_raw_mutex);
+ kref_put(&serio_raw->kref, serio_raw_free);
return err;
}
@@ -334,7 +350,8 @@ static int serio_raw_reconnect(struct serio *serio)
struct serio_driver *drv = serio->drv;
if (!drv || !serio_raw) {
- printk(KERN_DEBUG "serio_raw: reconnect request, but serio is disconnected, ignoring...\n");
+ dev_dbg(&serio->dev,
+ "reconnect request, but serio is disconnected, ignoring...\n");
return -1;
}
@@ -345,22 +362,40 @@ static int serio_raw_reconnect(struct serio *serio)
return 0;
}
+/*
+ * Wake up users waiting for IO so they can disconnect from
+ * dead device.
+ */
+static void serio_raw_hangup(struct serio_raw *serio_raw)
+{
+ struct serio_raw_client *client;
+
+ serio_pause_rx(serio_raw->serio);
+ list_for_each_entry(client, &serio_raw->client_list, node)
+ kill_fasync(&client->fasync, SIGIO, POLL_HUP);
+ serio_continue_rx(serio_raw->serio);
+
+ wake_up_interruptible(&serio_raw->wait);
+}
+
+
static void serio_raw_disconnect(struct serio *serio)
{
- struct serio_raw *serio_raw;
+ struct serio_raw *serio_raw = serio_get_drvdata(serio);
+
+ misc_deregister(&serio_raw->dev);
mutex_lock(&serio_raw_mutex);
+ serio_raw->dead = true;
+ list_del_init(&serio_raw->node);
+ mutex_unlock(&serio_raw_mutex);
- serio_raw = serio_get_drvdata(serio);
+ serio_raw_hangup(serio_raw);
serio_close(serio);
- serio_set_drvdata(serio, NULL);
-
- serio_raw->serio = NULL;
- if (!serio_raw_cleanup(serio_raw))
- wake_up_interruptible(&serio_raw->wait);
+ kref_put(&serio_raw->kref, serio_raw_free);
- mutex_unlock(&serio_raw_mutex);
+ serio_set_drvdata(serio, NULL);
}
static struct serio_device_id serio_raw_serio_ids[] = {
@@ -391,7 +426,7 @@ static struct serio_driver serio_raw_drv = {
.connect = serio_raw_connect,
.reconnect = serio_raw_reconnect,
.disconnect = serio_raw_disconnect,
- .manual_bind = 1,
+ .manual_bind = true,
};
static int __init serio_raw_init(void)