From 5dd3f3071070f5a306bdf8d474c80062f5691cba Mon Sep 17 00:00:00 2001 From: Andreas Oberritter Date: Thu, 23 Oct 2008 12:11:19 -0300 Subject: V4L/DVB (9361): Dynamic DVB minor allocation Implement dynamic minor allocation for DVB, to allow more than four devices of the same type per adapter, based on drivers/usb/core/file.c. Add a new config option, DVB_DYNAMIC_MINORS, to make use of this feature, which defaults to no for backwards compatibility. Signed-off-by: Andreas Oberritter Signed-off-by: Mauro Carvalho Chehab --- drivers/media/dvb/Kconfig | 13 +++++++++ drivers/media/dvb/dvb-core/dvbdev.c | 57 ++++++++++++++++++++++++------------- drivers/media/dvb/dvb-core/dvbdev.h | 1 + 3 files changed, 52 insertions(+), 19 deletions(-) diff --git a/drivers/media/dvb/Kconfig b/drivers/media/dvb/Kconfig index 0bcd852576d6..40ebde53b3ce 100644 --- a/drivers/media/dvb/Kconfig +++ b/drivers/media/dvb/Kconfig @@ -2,6 +2,19 @@ # DVB device configuration # +config DVB_DYNAMIC_MINORS + bool "Dynamic DVB minor allocation" + depends on DVB_CORE + default n + help + If you say Y here, the DVB subsystem will use dynamic minor + allocation for any device that uses the DVB major number. + This means that you can have more than 4 of a single type + of device (like demuxes and frontends) per adapter, but udev + will be required to manage the device nodes. + + If you are unsure about this, say N here. + menuconfig DVB_CAPTURE_DRIVERS bool "DVB/ATSC adapters" depends on DVB_CORE diff --git a/drivers/media/dvb/dvb-core/dvbdev.c b/drivers/media/dvb/dvb-core/dvbdev.c index a113744a56cc..e363a3b5054c 100644 --- a/drivers/media/dvb/dvb-core/dvbdev.c +++ b/drivers/media/dvb/dvb-core/dvbdev.c @@ -50,33 +50,27 @@ static const char * const dnames[] = { "net", "osd" }; +#ifdef CONFIG_DVB_DYNAMIC_MINORS +#define MAX_DVB_MINORS 256 +#define DVB_MAX_IDS MAX_DVB_MINORS +#else #define DVB_MAX_IDS 4 #define nums2minor(num,type,id) ((num << 6) | (id << 4) | type) #define MAX_DVB_MINORS (DVB_MAX_ADAPTERS*64) +#endif static struct class *dvb_class; -static struct dvb_device* dvbdev_find_device (int minor) -{ - struct dvb_adapter *adap; - - list_for_each_entry(adap, &dvb_adapter_list, list_head) { - struct dvb_device *dev; - list_for_each_entry(dev, &adap->device_list, list_head) - if (nums2minor(adap->num, dev->type, dev->id) == minor) - return dev; - } - - return NULL; -} - +static struct dvb_device *dvb_minors[MAX_DVB_MINORS]; +static DECLARE_RWSEM(minor_rwsem); static int dvb_device_open(struct inode *inode, struct file *file) { struct dvb_device *dvbdev; lock_kernel(); - dvbdev = dvbdev_find_device (iminor(inode)); + down_read(&minor_rwsem); + dvbdev = dvb_minors[iminor(inode)]; if (dvbdev && dvbdev->fops) { int err = 0; @@ -92,9 +86,11 @@ static int dvb_device_open(struct inode *inode, struct file *file) file->f_op = fops_get(old_fops); } fops_put(old_fops); + up_read(&minor_rwsem); unlock_kernel(); return err; } + up_read(&minor_rwsem); unlock_kernel(); return -ENODEV; } @@ -192,6 +188,7 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev, struct dvb_device *dvbdev; struct file_operations *dvbdevfops; struct device *clsdev; + int minor; int id; mutex_lock(&dvbdev_register_lock); @@ -231,6 +228,26 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev, list_add_tail (&dvbdev->list_head, &adap->device_list); + down_write(&minor_rwsem); +#ifdef CONFIG_DVB_DYNAMIC_MINORS + for (minor = 0; minor < MAX_DVB_MINORS; minor++) + if (dvb_minors[minor] == NULL) + break; + + if (minor == MAX_DVB_MINORS) { + kfree(dvbdevfops); + kfree(dvbdev); + mutex_unlock(&dvbdev_register_lock); + return -EINVAL; + } +#else + minor = nums2minor(adap->num, type, id); +#endif + + dvbdev->minor = minor; + dvb_minors[minor] = dvbdev; + up_write(&minor_rwsem); + mutex_unlock(&dvbdev_register_lock); clsdev = device_create(dvb_class, adap->device, @@ -243,8 +260,7 @@ int dvb_register_device(struct dvb_adapter *adap, struct dvb_device **pdvbdev, } dprintk(KERN_DEBUG "DVB: register adapter%d/%s%d @ minor: %i (0x%02x)\n", - adap->num, dnames[type], id, nums2minor(adap->num, type, id), - nums2minor(adap->num, type, id)); + adap->num, dnames[type], id, minor, minor); return 0; } @@ -256,8 +272,11 @@ void dvb_unregister_device(struct dvb_device *dvbdev) if (!dvbdev) return; - device_destroy(dvb_class, MKDEV(DVB_MAJOR, nums2minor(dvbdev->adapter->num, - dvbdev->type, dvbdev->id))); + down_write(&minor_rwsem); + dvb_minors[dvbdev->minor] = NULL; + up_write(&minor_rwsem); + + device_destroy(dvb_class, MKDEV(DVB_MAJOR, dvbdev->minor)); list_del (&dvbdev->list_head); kfree (dvbdev->fops); diff --git a/drivers/media/dvb/dvb-core/dvbdev.h b/drivers/media/dvb/dvb-core/dvbdev.h index 574e336bac35..dca49cf962e8 100644 --- a/drivers/media/dvb/dvb-core/dvbdev.h +++ b/drivers/media/dvb/dvb-core/dvbdev.h @@ -74,6 +74,7 @@ struct dvb_device { struct file_operations *fops; struct dvb_adapter *adapter; int type; + int minor; u32 id; /* in theory, 'users' can vanish now, -- cgit v1.2.3