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path: root/drivers/usb/serial/usb-serial.c
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Diffstat (limited to 'drivers/usb/serial/usb-serial.c')
-rw-r--r--drivers/usb/serial/usb-serial.c133
1 files changed, 62 insertions, 71 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 5f6b1ff9d29e..cb27fcb2fc90 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -37,11 +37,15 @@
#include <linux/usb.h>
#include <linux/usb/serial.h>
#include <linux/kfifo.h>
+#include <linux/idr.h>
#include "pl2303.h"
#define DRIVER_AUTHOR "Greg Kroah-Hartman <gregkh@linuxfoundation.org>"
#define DRIVER_DESC "USB Serial Driver core"
+#define USB_SERIAL_TTY_MAJOR 188
+#define USB_SERIAL_TTY_MINORS 512 /* should be enough for a while */
+
/* There is no MODULE_DEVICE_TABLE for usbserial.c. Instead
the MODULE_DEVICE_TABLE declarations in each serial driver
cause the "hotplug" program to pull in whatever module is necessary
@@ -49,81 +53,75 @@
drivers depend on it.
*/
-static struct usb_serial *serial_table[SERIAL_TTY_MINORS];
+static DEFINE_IDR(serial_minors);
static DEFINE_MUTEX(table_lock);
static LIST_HEAD(usb_serial_driver_list);
/*
- * Look up the serial structure. If it is found and it hasn't been
- * disconnected, return with its disc_mutex held and its refcount
- * incremented. Otherwise return NULL.
+ * Look up the serial port structure. If it is found and it hasn't been
+ * disconnected, return with the parent usb_serial structure's disc_mutex held
+ * and its refcount incremented. Otherwise return NULL.
*/
-struct usb_serial *usb_serial_get_by_index(unsigned index)
+struct usb_serial_port *usb_serial_port_get_by_minor(unsigned minor)
{
struct usb_serial *serial;
+ struct usb_serial_port *port;
mutex_lock(&table_lock);
- serial = serial_table[index];
-
- if (serial) {
- mutex_lock(&serial->disc_mutex);
- if (serial->disconnected) {
- mutex_unlock(&serial->disc_mutex);
- serial = NULL;
- } else {
- kref_get(&serial->kref);
- }
+ port = idr_find(&serial_minors, minor);
+ if (!port)
+ goto exit;
+
+ serial = port->serial;
+ mutex_lock(&serial->disc_mutex);
+ if (serial->disconnected) {
+ mutex_unlock(&serial->disc_mutex);
+ port = NULL;
+ } else {
+ kref_get(&serial->kref);
}
+exit:
mutex_unlock(&table_lock);
- return serial;
+ return port;
}
-static struct usb_serial *get_free_serial(struct usb_serial *serial,
- int num_ports, unsigned int *minor)
+static int allocate_minors(struct usb_serial *serial, int num_ports)
{
+ struct usb_serial_port *port;
unsigned int i, j;
- int good_spot;
+ int minor;
dev_dbg(&serial->interface->dev, "%s %d\n", __func__, num_ports);
- *minor = 0;
mutex_lock(&table_lock);
- for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
- if (serial_table[i])
- continue;
-
- good_spot = 1;
- for (j = 1; j <= num_ports-1; ++j)
- if ((i+j >= SERIAL_TTY_MINORS) || (serial_table[i+j])) {
- good_spot = 0;
- i += j;
- break;
- }
- if (good_spot == 0)
- continue;
-
- *minor = i;
- j = 0;
- dev_dbg(&serial->interface->dev, "%s - minor base = %d\n", __func__, *minor);
- for (i = *minor; (i < (*minor + num_ports)) && (i < SERIAL_TTY_MINORS); ++i) {
- serial_table[i] = serial;
- serial->port[j++]->number = i;
- }
- mutex_unlock(&table_lock);
- return serial;
+ for (i = 0; i < num_ports; ++i) {
+ port = serial->port[i];
+ minor = idr_alloc(&serial_minors, port, 0, 0, GFP_KERNEL);
+ if (minor < 0)
+ goto error;
+ port->minor = minor;
+ port->port_number = i;
}
+ serial->minors_reserved = 1;
mutex_unlock(&table_lock);
- return NULL;
+ return 0;
+error:
+ /* unwind the already allocated minors */
+ for (j = 0; j < i; ++j)
+ idr_remove(&serial_minors, serial->port[j]->minor);
+ mutex_unlock(&table_lock);
+ return minor;
}
-static void return_serial(struct usb_serial *serial)
+static void release_minors(struct usb_serial *serial)
{
int i;
mutex_lock(&table_lock);
for (i = 0; i < serial->num_ports; ++i)
- serial_table[serial->minor + i] = NULL;
+ idr_remove(&serial_minors, serial->port[i]->minor);
mutex_unlock(&table_lock);
+ serial->minors_reserved = 0;
}
static void destroy_serial(struct kref *kref)
@@ -135,8 +133,8 @@ static void destroy_serial(struct kref *kref)
serial = to_usb_serial(kref);
/* return the minor range that this device had */
- if (serial->minor != SERIAL_TTY_NO_MINOR)
- return_serial(serial);
+ if (serial->minors_reserved)
+ release_minors(serial);
if (serial->attached && serial->type->release)
serial->type->release(serial);
@@ -185,13 +183,11 @@ static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
struct usb_serial_port *port;
int retval = -ENODEV;
- serial = usb_serial_get_by_index(idx);
- if (!serial)
+ port = usb_serial_port_get_by_minor(idx);
+ if (!port)
return retval;
- port = serial->port[idx - serial->minor];
- if (!port)
- goto error_no_port;
+ serial = port->serial;
if (!try_module_get(serial->type->driver.owner))
goto error_module_get;
@@ -218,7 +214,6 @@ static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
error_get_interface:
module_put(serial->type->driver.owner);
error_module_get:
- error_no_port:
usb_serial_put(serial);
mutex_unlock(&serial->disc_mutex);
return retval;
@@ -452,14 +447,16 @@ static int serial_break(struct tty_struct *tty, int break_state)
static int serial_proc_show(struct seq_file *m, void *v)
{
struct usb_serial *serial;
+ struct usb_serial_port *port;
int i;
char tmp[40];
seq_puts(m, "usbserinfo:1.0 driver:2.0\n");
- for (i = 0; i < SERIAL_TTY_MINORS; ++i) {
- serial = usb_serial_get_by_index(i);
- if (serial == NULL)
+ for (i = 0; i < USB_SERIAL_TTY_MINORS; ++i) {
+ port = usb_serial_port_get_by_minor(i);
+ if (port == NULL)
continue;
+ serial = port->serial;
seq_printf(m, "%d:", i);
if (serial->type->driver.owner)
@@ -471,7 +468,7 @@ static int serial_proc_show(struct seq_file *m, void *v)
le16_to_cpu(serial->dev->descriptor.idVendor),
le16_to_cpu(serial->dev->descriptor.idProduct));
seq_printf(m, " num_ports:%d", serial->num_ports);
- seq_printf(m, " port:%d", i - serial->minor + 1);
+ seq_printf(m, " port:%d", port->port_number);
usb_make_path(serial->dev, tmp, sizeof(tmp));
seq_printf(m, " path:%s", tmp);
@@ -613,7 +610,7 @@ static struct usb_serial *create_serial(struct usb_device *dev,
serial->interface = usb_get_intf(interface);
kref_init(&serial->kref);
mutex_init(&serial->disc_mutex);
- serial->minor = SERIAL_TTY_NO_MINOR;
+ serial->minors_reserved = 0;
return serial;
}
@@ -722,7 +719,6 @@ static int usb_serial_probe(struct usb_interface *interface,
struct usb_endpoint_descriptor *bulk_out_endpoint[MAX_NUM_PORTS];
struct usb_serial_driver *type = NULL;
int retval;
- unsigned int minor;
int buffer_size;
int i;
int j;
@@ -1039,16 +1035,15 @@ static int usb_serial_probe(struct usb_interface *interface,
*/
serial->disconnected = 1;
- if (get_free_serial(serial, num_ports, &minor) == NULL) {
- dev_err(ddev, "No more free serial devices\n");
+ if (allocate_minors(serial, num_ports)) {
+ dev_err(ddev, "No more free serial minor numbers\n");
goto probe_error;
}
- serial->minor = minor;
/* register all of the individual ports with the driver core */
for (i = 0; i < num_ports; ++i) {
port = serial->port[i];
- dev_set_name(&port->dev, "ttyUSB%d", port->number);
+ dev_set_name(&port->dev, "ttyUSB%d", port->minor);
dev_dbg(ddev, "registering %s", dev_name(&port->dev));
device_enable_async_suspend(&port->dev);
@@ -1059,7 +1054,7 @@ static int usb_serial_probe(struct usb_interface *interface,
serial->disconnected = 0;
- usb_serial_console_init(minor);
+ usb_serial_console_init(serial->port[0]->minor);
exit:
module_put(type->driver.owner);
return 0;
@@ -1223,17 +1218,13 @@ static struct usb_driver usb_serial_driver = {
static int __init usb_serial_init(void)
{
- int i;
int result;
- usb_serial_tty_driver = alloc_tty_driver(SERIAL_TTY_MINORS);
+ usb_serial_tty_driver = alloc_tty_driver(USB_SERIAL_TTY_MINORS);
if (!usb_serial_tty_driver)
return -ENOMEM;
/* Initialize our global data */
- for (i = 0; i < SERIAL_TTY_MINORS; ++i)
- serial_table[i] = NULL;
-
result = bus_register(&usb_serial_bus_type);
if (result) {
pr_err("%s - registering bus driver failed\n", __func__);
@@ -1242,7 +1233,7 @@ static int __init usb_serial_init(void)
usb_serial_tty_driver->driver_name = "usbserial";
usb_serial_tty_driver->name = "ttyUSB";
- usb_serial_tty_driver->major = SERIAL_TTY_MAJOR;
+ usb_serial_tty_driver->major = USB_SERIAL_TTY_MAJOR;
usb_serial_tty_driver->minor_start = 0;
usb_serial_tty_driver->type = TTY_DRIVER_TYPE_SERIAL;
usb_serial_tty_driver->subtype = SERIAL_TYPE_NORMAL;