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staging: comedi: simplify comedi_board_minor_table[]
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`comedi_alloc_board_minor()` allocates and initializes a `struct
comedi_file_info` and a `struct comedi_device`, and assigns a board
minor device number (if there are any available), storing a pointer to
the allocated `struct comedi_file_info` in
`comedi_board_minor_table[minor]` where `minor` is the board minor
device number.

There is no longer anything useful in the `struct comedi_file_info`
apart from the pointer to the `struct comedi_device` that was allocated,
so the `struct comedi_file_info` is superfluous.

Change `comedi_board_minor_table[]` to hold pointers to the actual
`struct comedi_device`'s.  `comedi_alloc_board_minor()` no longer needs
to allocate a `struct comedi_file_info`.  Replace
`comedi_free_board_file_info()` with `comedi_free_board_dev()` with its
parameter pointing to the `struct comedi_device` to be freed (there is
no longer a `struct comedi_file_info` to be freed).

There are consequential changes to `comedi_dev_from_board_minor()`,
`comedi_clear_board_minor()` (which now returns a `struct comedi_device
*`), `comedi_free_board_minor()`, `comedi_release_hardware_device()` and
`comedi_unlocked_ioctl()` (when dealing with detachment of a dynamically
allocated comedi device by the `COMEDI_DEVCONFIG` ioctl).

`comedi_dev_from_file_info()` is no longer used as a result of the above
changes so remove it.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Ian Abbott authored and Greg Kroah-Hartman committed Apr 5, 2013
1 parent bd5b417 commit cb6b79d
Showing 1 changed file with 26 additions and 44 deletions.
70 changes: 26 additions & 44 deletions drivers/staging/comedi/comedi_fops.c
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Original file line number Diff line number Diff line change
Expand Up @@ -88,7 +88,7 @@ struct comedi_file_info {
};

static DEFINE_MUTEX(comedi_board_minor_table_lock);
static struct comedi_file_info
static struct comedi_device
*comedi_board_minor_table[COMEDI_NUM_BOARD_MINORS];

static DEFINE_MUTEX(comedi_subdevice_minor_table_lock);
Expand Down Expand Up @@ -126,30 +126,26 @@ static void comedi_device_cleanup(struct comedi_device *dev)
mutex_destroy(&dev->mutex);
}

static struct comedi_file_info *comedi_clear_board_minor(unsigned minor)
static struct comedi_device *comedi_clear_board_minor(unsigned minor)
{
struct comedi_file_info *info;
struct comedi_device *dev;

mutex_lock(&comedi_board_minor_table_lock);
info = comedi_board_minor_table[minor];
dev = comedi_board_minor_table[minor];
comedi_board_minor_table[minor] = NULL;
mutex_unlock(&comedi_board_minor_table_lock);
return info;
return dev;
}

static void comedi_free_board_file_info(struct comedi_file_info *info)
static void comedi_free_board_dev(struct comedi_device *dev)
{
if (info) {
struct comedi_device *dev = info->device;
if (dev) {
if (dev->class_dev) {
device_destroy(comedi_class,
MKDEV(COMEDI_MAJOR, dev->minor));
}
comedi_device_cleanup(dev);
kfree(dev);
if (dev) {
if (dev->class_dev) {
device_destroy(comedi_class,
MKDEV(COMEDI_MAJOR, dev->minor));
}
kfree(info);
comedi_device_cleanup(dev);
kfree(dev);
}
}

Expand All @@ -166,21 +162,15 @@ static struct comedi_subdevice
return s;
}

static struct comedi_device *
comedi_dev_from_file_info(struct comedi_file_info *info)
{
return info ? info->device : NULL;
}

static struct comedi_device *comedi_dev_from_board_minor(unsigned minor)
{
struct comedi_file_info *info;
struct comedi_device *dev;

BUG_ON(minor >= COMEDI_NUM_BOARD_MINORS);
mutex_lock(&comedi_board_minor_table_lock);
info = comedi_board_minor_table[minor];
dev = comedi_board_minor_table[minor];
mutex_unlock(&comedi_board_minor_table_lock);
return comedi_dev_from_file_info(info);
return dev;
}

static struct comedi_device *comedi_dev_from_subdevice_minor(unsigned minor)
Expand Down Expand Up @@ -1782,11 +1772,11 @@ static long comedi_unlocked_ioctl(struct file *file, unsigned int cmd,
dev->minor >= comedi_num_legacy_minors) {
/* Successfully unconfigured a dynamically
* allocated device. Try and remove it. */
struct comedi_file_info *info;
info = comedi_clear_board_minor(dev->minor);
if (info) {
struct comedi_device *devr;
devr = comedi_clear_board_minor(dev->minor);
if (dev == devr) {
mutex_unlock(&dev->mutex);
comedi_free_board_file_info(info);
comedi_free_board_dev(dev);
return rc;
}
}
Expand Down Expand Up @@ -2396,28 +2386,21 @@ EXPORT_SYMBOL(comedi_event);
/* Note: the ->mutex is pre-locked on successful return */
struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device)
{
struct comedi_file_info *info;
struct comedi_device *dev;
struct device *csdev;
unsigned i;

info = kzalloc(sizeof(*info), GFP_KERNEL);
if (info == NULL)
return ERR_PTR(-ENOMEM);
dev = kzalloc(sizeof(struct comedi_device), GFP_KERNEL);
if (dev == NULL) {
kfree(info);
if (dev == NULL)
return ERR_PTR(-ENOMEM);
}
info->device = dev;
comedi_device_init(dev);
comedi_set_hw_dev(dev, hardware_device);
mutex_lock(&dev->mutex);
mutex_lock(&comedi_board_minor_table_lock);
for (i = hardware_device ? comedi_num_legacy_minors : 0;
i < COMEDI_NUM_BOARD_MINORS; ++i) {
if (comedi_board_minor_table[i] == NULL) {
comedi_board_minor_table[i] = info;
comedi_board_minor_table[i] = dev;
break;
}
}
Expand All @@ -2426,7 +2409,6 @@ struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device)
mutex_unlock(&dev->mutex);
comedi_device_cleanup(dev);
kfree(dev);
kfree(info);
pr_err("comedi: error: ran out of minor numbers for board device files.\n");
return ERR_PTR(-EBUSY);
}
Expand All @@ -2443,22 +2425,22 @@ struct comedi_device *comedi_alloc_board_minor(struct device *hardware_device)
static void comedi_free_board_minor(unsigned minor)
{
BUG_ON(minor >= COMEDI_NUM_BOARD_MINORS);
comedi_free_board_file_info(comedi_clear_board_minor(minor));
comedi_free_board_dev(comedi_clear_board_minor(minor));
}

void comedi_release_hardware_device(struct device *hardware_device)
{
int minor;
struct comedi_file_info *info;
struct comedi_device *dev;

for (minor = comedi_num_legacy_minors; minor < COMEDI_NUM_BOARD_MINORS;
minor++) {
mutex_lock(&comedi_board_minor_table_lock);
info = comedi_board_minor_table[minor];
if (info && info->device->hw_dev == hardware_device) {
dev = comedi_board_minor_table[minor];
if (dev && dev->hw_dev == hardware_device) {
comedi_board_minor_table[minor] = NULL;
mutex_unlock(&comedi_board_minor_table_lock);
comedi_free_board_file_info(info);
comedi_free_board_dev(dev);
break;
}
mutex_unlock(&comedi_board_minor_table_lock);
Expand Down

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