[PATCH 0/2] staging: comedi: hide subdevice runflags stuff

[PATCH 0/2] staging: comedi: hide subdevice runflags stuff

[Ian Abbott]

Keep the details of the comedi subdevice `runflags` member local to
"comedi_fops.c".  In particular, the usage of the
`COMEDI_SRF_FREE_SPRIV` run-flag doesn't really fit in all that well
with the others.  It's used as a marker to indicate the subdevice's
`private` pointer can be automatically freed by the subdevice
clean-up code, whereas the others are associated with the operation of
asynchronous comedi commands.  Abstract it's usage away in a couple of
new wrapper functions.

1) staging: comedi: wrap COMEDI_SRF_FREE_SPRIV usage
2) staging: comedi: move COMEDI_SRF_... macros to "comedi_fops.c"

 drivers/staging/comedi/comedi_fops.c               | 41 ++++++++++++++++++++--
 drivers/staging/comedi/comedi_internal.h           |  1 +
 drivers/staging/comedi/comedidev.h                 | 18 +---------
 drivers/staging/comedi/drivers.c                   |  2 +-
 .../staging/comedi/drivers/amplc_dio200_common.c   |  6 ++--
 5 files changed, 45 insertions(+), 23 deletions(-)

[PATCH 1/2] staging: comedi: wrap COMEDI_SRF_FREE_SPRIV usage

[Ian Abbott]

The `COMEDI_SRF_FREE_SPRIV` flag in the `runflags` member of `struct
comedi_subdevice` indicates that the memory pointed to by the `private`
member can be automatically freed by the comedi core on subdevice
clean-up (when the low-level comedi device is being "detached").  the
flag doesn't really belong in `runflags`, but it was somewhere
convenient to keep it without having to add a new member to the
structure.

Rather than access the `COMEDI_SRF_FREE_SPRIV` flag directly, use some
new wrapper functions:

* comedi_can_auto_free_spriv(s) - checks whether the subdevice's
  `s->private` points to memory that can be freed automatically.
* comedi_set_spriv_auto_free(s) - marks the subdevice as having a
  `s->private` that points to memory that can be freed automatically.

Export `comedi_set_spriv_auto_free()` for use by the low-level comedi
driver modules, in particular the "amplc_dio200_common" module.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/comedi_fops.c               | 24 ++++++++++++++++++++--
 drivers/staging/comedi/comedi_internal.h           |  1 +
 drivers/staging/comedi/comedidev.h                 |  1 +
 drivers/staging/comedi/drivers.c                   |  2 +-
 .../staging/comedi/drivers/amplc_dio200_common.c   |  6 +++---
 5 files changed, 28 insertions(+), 6 deletions(-)

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index e78ddbe..fc339c5 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -679,8 +679,28 @@ static bool comedi_is_subdevice_idle(struct comedi_subdevice *s)
 	return !(runflags & COMEDI_SRF_BUSY_MASK);
 }
 
+bool comedi_can_auto_free_spriv(struct comedi_subdevice *s)
+{
+	unsigned runflags = __comedi_get_subdevice_runflags(s);
+
+	return runflags & COMEDI_SRF_FREE_SPRIV;
+}
+
+/**
+ * comedi_set_spriv_auto_free - mark subdevice private data as freeable
+ * @s: comedi_subdevice struct
+ *
+ * Mark the subdevice as having a pointer to private data that can be
+ * automatically freed by the comedi core during the detach.
+ */
+void comedi_set_spriv_auto_free(struct comedi_subdevice *s)
+{
+	__comedi_set_subdevice_runflags(s, COMEDI_SRF_FREE_SPRIV);
+}
+EXPORT_SYMBOL_GPL(comedi_set_spriv_auto_free);
+
 /**
- * comedi_alloc_spriv() - Allocate memory for the subdevice private data.
+ * comedi_alloc_spriv - Allocate memory for the subdevice private data.
  * @s: comedi_subdevice struct
  * @size: size of the memory to allocate
  *
@@ -691,7 +711,7 @@ void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size)
 {
 	s->private = kzalloc(size, GFP_KERNEL);
 	if (s->private)
-		s->runflags |= COMEDI_SRF_FREE_SPRIV;
+		comedi_set_spriv_auto_free(s);
 	return s->private;
 }
 EXPORT_SYMBOL_GPL(comedi_alloc_spriv);
diff --git a/drivers/staging/comedi/comedi_internal.h b/drivers/staging/comedi/comedi_internal.h
index 3b91853..cd9437f 100644
--- a/drivers/staging/comedi/comedi_internal.h
+++ b/drivers/staging/comedi/comedi_internal.h
@@ -33,6 +33,7 @@ struct comedi_buf_map *comedi_buf_map_from_subdev_get(
 		struct comedi_subdevice *s);
 unsigned int comedi_buf_write_n_allocated(struct comedi_subdevice *s);
 void comedi_device_cancel_all(struct comedi_device *dev);
+bool comedi_can_auto_free_spriv(struct comedi_subdevice *s);
 
 extern unsigned int comedi_default_buf_size_kb;
 extern unsigned int comedi_default_buf_maxsize_kb;
diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index dfab5a8..52071f7 100644
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -323,6 +323,7 @@ int comedi_dev_put(struct comedi_device *dev);
 bool comedi_is_subdevice_running(struct comedi_subdevice *s);
 
 void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size);
+void comedi_set_spriv_auto_free(struct comedi_subdevice *s);
 
 int comedi_check_chanlist(struct comedi_subdevice *s,
 			  int n,
diff --git a/drivers/staging/comedi/drivers.c b/drivers/staging/comedi/drivers.c
index 57dcffe..ed0b60c 100644
--- a/drivers/staging/comedi/drivers.c
+++ b/drivers/staging/comedi/drivers.c
@@ -125,7 +125,7 @@ static void comedi_device_detach_cleanup(struct comedi_device *dev)
 	if (dev->subdevices) {
 		for (i = 0; i < dev->n_subdevices; i++) {
 			s = &dev->subdevices[i];
-			if (s->runflags & COMEDI_SRF_FREE_SPRIV)
+			if (comedi_can_auto_free_spriv(s))
 				kfree(s->private);
 			comedi_free_subdevice_minor(s);
 			if (s->async) {
diff --git a/drivers/staging/comedi/drivers/amplc_dio200_common.c b/drivers/staging/comedi/drivers/amplc_dio200_common.c
index d15a3dc..3a8b3f2 100644
--- a/drivers/staging/comedi/drivers/amplc_dio200_common.c
+++ b/drivers/staging/comedi/drivers/amplc_dio200_common.c
@@ -593,10 +593,10 @@ static int dio200_subdev_8254_init(struct comedi_device *dev,
 	 * There could be multiple timers so this driver does not
 	 * use dev->pacer to save the i8254 pointer. Instead,
 	 * comedi_8254_subdevice_init() saved the i8254 pointer in
-	 * s->private. Set the runflag bit so that the core will
-	 * automatically free it when the driver is detached.
+	 * s->private.  Mark the subdevice as having private data
+	 * to be automatically freed when the device is detached.
 	 */
-	s->runflags |= COMEDI_SRF_FREE_SPRIV;
+	comedi_set_spriv_auto_free(s);
 
 	/* Initialize channels. */
 	if (board->has_clk_gat_sce) {
-- 
2.1.4

[PATCH 2/2] staging: comedi: move COMEDI_SRF_... macros to "comedi_fops.c"

[Ian Abbott]

The `COMEDI_SRF_...` macros define flag combinations in the `runflags`
member of `struct comedi_subdevice`.  They are only used directly in
"comedi_fops.c", so move them to there.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
---
 drivers/staging/comedi/comedi_fops.c | 17 +++++++++++++++++
 drivers/staging/comedi/comedidev.h   | 17 -----------------
 2 files changed, 17 insertions(+), 17 deletions(-)

diff --git a/drivers/staging/comedi/comedi_fops.c b/drivers/staging/comedi/comedi_fops.c
index fc339c5..6f269cc 100644
--- a/drivers/staging/comedi/comedi_fops.c
+++ b/drivers/staging/comedi/comedi_fops.c
@@ -44,6 +44,23 @@
 #include "comedi_internal.h"
 
 /**
+ * comedi_subdevice "runflags"
+ * @COMEDI_SRF_RT:		DEPRECATED: command is running real-time
+ * @COMEDI_SRF_ERROR:		indicates an COMEDI_CB_ERROR event has occurred
+ *				since the last command was started
+ * @COMEDI_SRF_RUNNING:		command is running
+ * @COMEDI_SRF_FREE_SPRIV:	free s->private on detach
+ *
+ * @COMEDI_SRF_BUSY_MASK:	runflags that indicate the subdevice is "busy"
+ */
+#define COMEDI_SRF_RT		BIT(1)
+#define COMEDI_SRF_ERROR	BIT(2)
+#define COMEDI_SRF_RUNNING	BIT(27)
+#define COMEDI_SRF_FREE_SPRIV	BIT(31)
+
+#define COMEDI_SRF_BUSY_MASK	(COMEDI_SRF_ERROR | COMEDI_SRF_RUNNING)
+
+/**
  * struct comedi_file - per-file private data for comedi device
  * @dev: comedi_device struct
  * @read_subdev: current "read" subdevice
diff --git a/drivers/staging/comedi/comedidev.h b/drivers/staging/comedi/comedidev.h
index 52071f7..28f2606 100644
--- a/drivers/staging/comedi/comedidev.h
+++ b/drivers/staging/comedi/comedidev.h
@@ -303,23 +303,6 @@ void comedi_event(struct comedi_device *dev, struct comedi_subdevice *s);
 struct comedi_device *comedi_dev_get_from_minor(unsigned minor);
 int comedi_dev_put(struct comedi_device *dev);
 
-/**
- * comedi_subdevice "runflags"
- * @COMEDI_SRF_RT:		DEPRECATED: command is running real-time
- * @COMEDI_SRF_ERROR:		indicates an COMEDI_CB_ERROR event has occurred
- *				since the last command was started
- * @COMEDI_SRF_RUNNING:		command is running
- * @COMEDI_SRF_FREE_SPRIV:	free s->private on detach
- *
- * @COMEDI_SRF_BUSY_MASK:	runflags that indicate the subdevice is "busy"
- */
-#define COMEDI_SRF_RT		BIT(1)
-#define COMEDI_SRF_ERROR	BIT(2)
-#define COMEDI_SRF_RUNNING	BIT(27)
-#define COMEDI_SRF_FREE_SPRIV	BIT(31)
-
-#define COMEDI_SRF_BUSY_MASK	(COMEDI_SRF_ERROR | COMEDI_SRF_RUNNING)
-
 bool comedi_is_subdevice_running(struct comedi_subdevice *s);
 
 void *comedi_alloc_spriv(struct comedi_subdevice *s, size_t size);
-- 
2.1.4

RE: [PATCH 0/2] staging: comedi: hide subdevice runflags stuff

[Hartley Sweeten]

On Tuesday, April 21, 2015 5:18 AM, Ian Abbott wrote:
> Keep the details of the comedi subdevice `runflags` member local to
> "comedi_fops.c".  In particular, the usage of the
> `COMEDI_SRF_FREE_SPRIV` run-flag doesn't really fit in all that well
> with the others.  It's used as a marker to indicate the subdevice's
> `private` pointer can be automatically freed by the subdevice
> clean-up code, whereas the others are associated with the operation of
> asynchronous comedi commands.  Abstract it's usage away in a couple of
> new wrapper functions.
>
> 1) staging: comedi: wrap COMEDI_SRF_FREE_SPRIV usage
> 2) staging: comedi: move COMEDI_SRF_... macros to "comedi_fops.c"
>
>  drivers/staging/comedi/comedi_fops.c               | 41 ++++++++++++++++++++--
>  drivers/staging/comedi/comedi_internal.h           |  1 +
>  drivers/staging/comedi/comedidev.h                 | 18 +---------
>  drivers/staging/comedi/drivers.c                   |  2 +-
>  .../staging/comedi/drivers/amplc_dio200_common.c   |  6 ++--
>  5 files changed, 45 insertions(+), 23 deletions(-)

Reviewed-by: H Hartley Sweeten <hsweeten@visionengravers.com>

Moving comedi to mainline soon?

[Joe Perches]

It seems that most all of the comedi code cleanliness
issues have been resolved.

What's left before this is accepted into mainline?