[PATCH] rc-core: use an IDA rather than a bitmap

David Härdeman
2015-04-02T10:19:28Z

This patch changes rc-core to use the kernel facilities that are already
available for handling unique numbers instead of rolling its own bitmap
stuff.

Stefan, this should apply cleanly to the media git tree...could you test it?
---
drivers/media/rc/rc-ir-raw.c | 2 +-
drivers/media/rc/rc-main.c | 40 ++++++++++++++++++++--------------------
include/media/rc-core.h | 4 ++--
3 files changed, 23 insertions(+), 23 deletions(-)

diff --git a/drivers/media/rc/rc-ir-raw.c b/drivers/media/rc/rc-ir-raw.c
index b732ac6..ad26052 100644
--- a/drivers/media/rc/rc-ir-raw.c
+++ b/drivers/media/rc/rc-ir-raw.c
@@ -271,7 +271,7 @@ int ir_raw_event_register(struct rc_dev *dev)

spin_lock_init(&dev->raw->lock);
dev->raw->thread = kthread_run(ir_raw_event_thread, dev->raw,
- "rc%ld", dev->devno);
+ "rc%u", dev->minor);

if (IS_ERR(dev->raw->thread)) {
rc = PTR_ERR(dev->raw->thread);
diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c
index f8c5e47..d068c4e 100644
--- a/drivers/media/rc/rc-main.c
+++ b/drivers/media/rc/rc-main.c
@@ -18,17 +18,15 @@
#include <linux/input.h>
#include <linux/leds.h>
#include <linux/slab.h>
+#include <linux/idr.h>
#include <linux/device.h>
#include <linux/module.h>
#include "rc-core-priv.h"

-/* Bitmap to store allocated device numbers from 0 to IRRCV_NUM_DEVICES - 1 */
-#define IRRCV_NUM_DEVICES 256
-static DECLARE_BITMAP(ir_core_dev_number, IRRCV_NUM_DEVICES);
-
/* Sizes are in bytes, 256 bytes allows for 32 entries on x64 */
#define IR_TAB_MIN_SIZE 256
#define IR_TAB_MAX_SIZE 8192
+#define RC_DEV_MAX 256

/* FIXME: IR_KEYPRESS_TIMEOUT should be protocol specific */
#define IR_KEYPRESS_TIMEOUT 250
@@ -38,6 +36,9 @@ static LIST_HEAD(rc_map_list);
static DEFINE_SPINLOCK(rc_map_lock);
static struct led_trigger *led_feedback;

+/* Used to keep track of rc devices */
+static DEFINE_IDA(rc_ida);
+
static struct rc_map_list *seek_rc_map(const char *name)
{
struct rc_map_list *map = NULL;
@@ -1312,7 +1313,9 @@ int rc_register_device(struct rc_dev *dev)
static bool raw_init = false; /* raw decoders loaded? */
struct rc_map *rc_map;
const char *path;
- int rc, devno, attr = 0;
+ int attr = 0;
+ int minor;
+ int rc;

if (!dev || !dev->map_name)
return -EINVAL;
@@ -1332,13 +1335,13 @@ int rc_register_device(struct rc_dev *dev)
if (dev->close)
dev->input_dev->close = ir_close;

- do {
- devno = find_first_zero_bit(ir_core_dev_number,
- IRRCV_NUM_DEVICES);
- /* No free device slots */
- if (devno >= IRRCV_NUM_DEVICES)
- return -ENOMEM;
- } while (test_and_set_bit(devno, ir_core_dev_number));
+ minor = ida_simple_get(&rc_ida, 0, RC_DEV_MAX, GFP_KERNEL);
+ if (minor < 0)
+ return minor;
+
+ dev->minor = minor;
+ dev_set_name(&dev->dev, "rc%u", dev->minor);
+ dev_set_drvdata(&dev->dev, dev);

dev->dev.groups = dev->sysfs_groups;
dev->sysfs_groups[attr++] = &rc_dev_protocol_attr_grp;
@@ -1358,9 +1361,6 @@ int rc_register_device(struct rc_dev *dev)
*/
mutex_lock(&dev->lock);

- dev->devno = devno;
- dev_set_name(&dev->dev, "rc%ld", dev->devno);
- dev_set_drvdata(&dev->dev, dev);
rc = device_add(&dev->dev);
if (rc)
goto out_unlock;
@@ -1433,8 +1433,8 @@ int rc_register_device(struct rc_dev *dev)

mutex_unlock(&dev->lock);

- IR_dprintk(1, "Registered rc%ld (driver: %s, remote: %s, mode %s)\n",
- dev->devno,
+ IR_dprintk(1, "Registered rc%u (driver: %s, remote: %s, mode %s)\n",
+ dev->minor,
dev->driver_name ? dev->driver_name : "unknown",
rc_map->name ? rc_map->name : "unknown",
dev->driver_type == RC_DRIVER_IR_RAW ? "raw" : "cooked");
@@ -1453,7 +1453,7 @@ out_dev:
device_del(&dev->dev);
out_unlock:
mutex_unlock(&dev->lock);
- clear_bit(dev->devno, ir_core_dev_number);
+ ida_simple_remove(&rc_ida, minor);
return rc;
}
EXPORT_SYMBOL_GPL(rc_register_device);
@@ -1465,8 +1465,6 @@ void rc_unregister_device(struct rc_dev *dev)

del_timer_sync(&dev->timer_keyup);

- clear_bit(dev->devno, ir_core_dev_number);
-
if (dev->driver_type == RC_DRIVER_IR_RAW)
ir_raw_event_unregister(dev);

@@ -1479,6 +1477,8 @@ void rc_unregister_device(struct rc_dev *dev)

device_del(&dev->dev);

+ ida_simple_remove(&rc_ida, dev->minor);
+
rc_free_device(dev);
}

diff --git a/include/media/rc-core.h b/include/media/rc-core.h
index 2c7fbca..6b4400c 100644
--- a/include/media/rc-core.h
+++ b/include/media/rc-core.h
@@ -69,7 +69,7 @@ enum rc_filter_type {
* @rc_map: current scan/key table
* @lock: used to ensure we've filled in all protocol details before
* anyone can call show_protocols or store_protocols
- * @devno: unique remote control device number
+ * @minor: unique minor remote control device number
* @raw: additional data for raw pulse/space devices
* @input_dev: the input child device used to communicate events to userspace
* @driver_type: specifies if protocol decoding is done in hardware or software
@@ -129,7 +129,7 @@ struct rc_dev {
const char *map_name;
struct rc_map rc_map;
struct mutex lock;
- unsigned long devno;
+ unsigned int minor;
struct ir_raw_event_ctrl *raw;
struct input_dev *input_dev;
enum rc_driver_type driver_type;