linux-omap.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid()
@ 2010-01-26 19:00 Kevin Hilman
  2010-01-26 19:00 ` [PATCH 2/2] OMAP: omap_device: when 'called from invalid state', print state Kevin Hilman
  2010-01-28  0:30 ` [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid() Paul Walmsley
  0 siblings, 2 replies; 6+ messages in thread
From: Kevin Hilman @ 2010-01-26 19:00 UTC (permalink / raw)
  To: linux-omap

The omap_device struct contains a 'struct platform_device'.  Normally,
converting a platform_device pointer to an omap_device pointer
consists of simply doing a container_of(), as is done currently by the
to_omap_device() macro.

However, if this is attempted when using platform_device that has not
been created as part of the omap_device creation, the container_of()
will point to a memory location before the platform_device pointer
which will contain random data.

Therefore, we need a way to detect valid omap_device pointers.  This
patch solves this by using the simple magic number approach.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
---
Changes from original version:
- set magic value before omap_device_register()

 arch/arm/plat-omap/include/plat/omap_device.h |    2 ++
 arch/arm/plat-omap/omap_device.c              |   16 ++++++++++++++++
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
index 76d4917..4677ff7 100644
--- a/arch/arm/plat-omap/include/plat/omap_device.h
+++ b/arch/arm/plat-omap/include/plat/omap_device.h
@@ -62,6 +62,7 @@
  *
  */
 struct omap_device {
+	u32                             magic;
 	struct platform_device		pdev;
 	struct omap_hwmod		**hwmods;
 	struct omap_device_pm_latency	*pm_lats;
@@ -81,6 +82,7 @@ int omap_device_shutdown(struct platform_device *pdev);
 
 /* Core code interface */
 
+bool omap_device_is_valid(struct omap_device *od);
 int omap_device_count_resources(struct omap_device *od);
 int omap_device_fill_resources(struct omap_device *od, struct resource *res);
 
diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index d8c75c8..187a08f 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -100,6 +100,8 @@
 # error Unknown OMAP device
 #endif
 
+#define OMAP_DEVICE_MAGIC 0xf00dcafe
+
 /* Private functions */
 
 /**
@@ -413,6 +415,8 @@ struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
 	od->pm_lats = pm_lats;
 	od->pm_lats_cnt = pm_lats_cnt;
 
+	od->magic = OMAP_DEVICE_MAGIC;
+
 	ret = omap_device_register(od);
 	if (ret)
 		goto odbs_exit4;
@@ -599,6 +603,18 @@ int omap_device_align_pm_lat(struct platform_device *pdev,
 }
 
 /**
+ * omap_device_is_valid()
+ * @od: struct omap_device *
+ *
+ * Return whether struct omap_device pointer @od points to a valid
+ * omap_device.
+ */
+bool omap_device_is_valid(struct omap_device *od)
+{
+	return (od && od->magic == OMAP_DEVICE_MAGIC);
+}
+
+/**
  * omap_device_get_pwrdm - return the powerdomain * associated with @od
  * @od: struct omap_device *
  *
-- 
1.6.6


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* [PATCH 2/2] OMAP: omap_device: when 'called from invalid state', print state
  2010-01-26 19:00 [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid() Kevin Hilman
@ 2010-01-26 19:00 ` Kevin Hilman
  2010-02-11  7:17   ` Paul Walmsley
  2010-01-28  0:30 ` [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid() Paul Walmsley
  1 sibling, 1 reply; 6+ messages in thread
From: Kevin Hilman @ 2010-01-26 19:00 UTC (permalink / raw)
  To: linux-omap

The omap_device_[enable|idle|shutdown] functions print a warning
when called from an invalid state.  Print the invalid state in
the warning messages.  This also uses __func__ to get the function
name.

Also, move the entire print string onto a single line to facilitate
grepping or error messages.  Recent discussions on LKML show
strong preference for grep-able code vs. strict 80 column limit.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
---
 arch/arm/plat-omap/omap_device.c |   12 ++++++------
 1 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index 187a08f..d4f34ea 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -476,8 +476,8 @@ int omap_device_enable(struct platform_device *pdev)
 	od = _find_by_pdev(pdev);
 
 	if (od->_state == OMAP_DEVICE_STATE_ENABLED) {
-		WARN(1, "omap_device: %s.%d: omap_device_enable() called from "
-		     "invalid state\n", od->pdev.name, od->pdev.id);
+		WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
+		     od->pdev.name, od->pdev.id, __func__, od->_state);
 		return -EINVAL;
 	}
 
@@ -515,8 +515,8 @@ int omap_device_idle(struct platform_device *pdev)
 	od = _find_by_pdev(pdev);
 
 	if (od->_state != OMAP_DEVICE_STATE_ENABLED) {
-		WARN(1, "omap_device: %s.%d: omap_device_idle() called from "
-		     "invalid state\n", od->pdev.name, od->pdev.id);
+		WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
+		     od->pdev.name, od->pdev.id, __func__, od->_state);
 		return -EINVAL;
 	}
 
@@ -548,8 +548,8 @@ int omap_device_shutdown(struct platform_device *pdev)
 
 	if (od->_state != OMAP_DEVICE_STATE_ENABLED &&
 	    od->_state != OMAP_DEVICE_STATE_IDLE) {
-		WARN(1, "omap_device: %s.%d: omap_device_shutdown() called "
-		     "from invalid state\n", od->pdev.name, od->pdev.id);
+		WARN(1, "omap_device: %s.%d: %s() called from invalid state %d\n",
+		     od->pdev.name, od->pdev.id, __func__, od->_state);
 		return -EINVAL;
 	}
 
-- 
1.6.6


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid()
  2010-01-26 19:00 [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid() Kevin Hilman
  2010-01-26 19:00 ` [PATCH 2/2] OMAP: omap_device: when 'called from invalid state', print state Kevin Hilman
@ 2010-01-28  0:30 ` Paul Walmsley
  2010-01-28 17:19   ` Kevin Hilman
  1 sibling, 1 reply; 6+ messages in thread
From: Paul Walmsley @ 2010-01-28  0:30 UTC (permalink / raw)
  To: Kevin Hilman; +Cc: linux-omap

Hi Kevin,

this looks fine.  Two quick comments:

On Tue, 26 Jan 2010, Kevin Hilman wrote:

> The omap_device struct contains a 'struct platform_device'.  Normally,
> converting a platform_device pointer to an omap_device pointer
> consists of simply doing a container_of(), as is done currently by the
> to_omap_device() macro.
> 
> However, if this is attempted when using platform_device that has not
> been created as part of the omap_device creation, the container_of()
> will point to a memory location before the platform_device pointer
> which will contain random data.
> 
> Therefore, we need a way to detect valid omap_device pointers.  This
> patch solves this by using the simple magic number approach.

Sounds okay; just FYI at some point in the future, it would be good for 
one of us to take a whack at converting omap_device to contain 
platform_device, the same way that platform_device contains struct device, 
etc..

> 
> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
> ---
> Changes from original version:
> - set magic value before omap_device_register()
> 
>  arch/arm/plat-omap/include/plat/omap_device.h |    2 ++
>  arch/arm/plat-omap/omap_device.c              |   16 ++++++++++++++++
>  2 files changed, 18 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
> index 76d4917..4677ff7 100644
> --- a/arch/arm/plat-omap/include/plat/omap_device.h
> +++ b/arch/arm/plat-omap/include/plat/omap_device.h
> @@ -62,6 +62,7 @@
>   *
>   */
>  struct omap_device {
> +	u32                             magic;
>  	struct platform_device		pdev;
>  	struct omap_hwmod		**hwmods;
>  	struct omap_device_pm_latency	*pm_lats;
> @@ -81,6 +82,7 @@ int omap_device_shutdown(struct platform_device *pdev);
>  
>  /* Core code interface */
>  
> +bool omap_device_is_valid(struct omap_device *od);
>  int omap_device_count_resources(struct omap_device *od);
>  int omap_device_fill_resources(struct omap_device *od, struct resource *res);
>  
> diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
> index d8c75c8..187a08f 100644
> --- a/arch/arm/plat-omap/omap_device.c
> +++ b/arch/arm/plat-omap/omap_device.c
> @@ -100,6 +100,8 @@
>  # error Unknown OMAP device
>  #endif
>  
> +#define OMAP_DEVICE_MAGIC 0xf00dcafe
> +
>  /* Private functions */
>  
>  /**
> @@ -413,6 +415,8 @@ struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
>  	od->pm_lats = pm_lats;
>  	od->pm_lats_cnt = pm_lats_cnt;
>  
> +	od->magic = OMAP_DEVICE_MAGIC;
> +
>  	ret = omap_device_register(od);
>  	if (ret)
>  		goto odbs_exit4;
> @@ -599,6 +603,18 @@ int omap_device_align_pm_lat(struct platform_device *pdev,
>  }
>  
>  /**
> + * omap_device_is_valid()

I think kerneldoc will want a short description after the function name.  
Can plug this in here during the merge process if you want...

> + * @od: struct omap_device *
> + *
> + * Return whether struct omap_device pointer @od points to a valid
> + * omap_device.
> + */
> +bool omap_device_is_valid(struct omap_device *od)
> +{
> +	return (od && od->magic == OMAP_DEVICE_MAGIC);
> +}
> +
> +/**
>   * omap_device_get_pwrdm - return the powerdomain * associated with @od
>   * @od: struct omap_device *
>   *
> -- 
> 1.6.6
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-omap" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> 


- Paul

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid()
  2010-01-28  0:30 ` [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid() Paul Walmsley
@ 2010-01-28 17:19   ` Kevin Hilman
  2010-02-21  8:35     ` Paul Walmsley
  0 siblings, 1 reply; 6+ messages in thread
From: Kevin Hilman @ 2010-01-28 17:19 UTC (permalink / raw)
  To: Paul Walmsley; +Cc: linux-omap

Paul Walmsley <paul@pwsan.com> writes:

> Hi Kevin,
>
> this looks fine.  Two quick comments:
>
> On Tue, 26 Jan 2010, Kevin Hilman wrote:
>
>> The omap_device struct contains a 'struct platform_device'.  Normally,
>> converting a platform_device pointer to an omap_device pointer
>> consists of simply doing a container_of(), as is done currently by the
>> to_omap_device() macro.
>> 
>> However, if this is attempted when using platform_device that has not
>> been created as part of the omap_device creation, the container_of()
>> will point to a memory location before the platform_device pointer
>> which will contain random data.
>> 
>> Therefore, we need a way to detect valid omap_device pointers.  This
>> patch solves this by using the simple magic number approach.
>
> Sounds okay; just FYI at some point in the future, it would be good for 
> one of us to take a whack at converting omap_device to contain 
> platform_device, the same way that platform_device contains struct device, 
> etc..

Hmm, not sure I follow...  

struct omap_device already contains a struct platform_device, which in
turn contains a struct device, so to get an omap_device from a struct
device, there are two container of operaions: to_platform_device() and
to_omap_device()


from omap_device.h:

struct omap_device {
	u32                             magic;
	struct platform_device		pdev;
        [...]
}
#define to_omap_device(x) container_of((x), struct omap_device, pdev)

from platform_device.h:
struct platform_device {
	const char	* name;
	int		id;
	struct device	dev;
        [...]
}
#define to_platform_device(x) container_of((x), struct platform_device, dev)

>> 
>> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
>> ---
>> Changes from original version:
>> - set magic value before omap_device_register()
>> 
>>  arch/arm/plat-omap/include/plat/omap_device.h |    2 ++
>>  arch/arm/plat-omap/omap_device.c              |   16 ++++++++++++++++
>>  2 files changed, 18 insertions(+), 0 deletions(-)
>> 
>> diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
>> index 76d4917..4677ff7 100644
>> --- a/arch/arm/plat-omap/include/plat/omap_device.h
>> +++ b/arch/arm/plat-omap/include/plat/omap_device.h
>> @@ -62,6 +62,7 @@
>>   *
>>   */
>>  struct omap_device {
>> +	u32                             magic;
>>  	struct platform_device		pdev;
>>  	struct omap_hwmod		**hwmods;
>>  	struct omap_device_pm_latency	*pm_lats;
>> @@ -81,6 +82,7 @@ int omap_device_shutdown(struct platform_device *pdev);
>>  
>>  /* Core code interface */
>>  
>> +bool omap_device_is_valid(struct omap_device *od);
>>  int omap_device_count_resources(struct omap_device *od);
>>  int omap_device_fill_resources(struct omap_device *od, struct resource *res);
>>  
>> diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
>> index d8c75c8..187a08f 100644
>> --- a/arch/arm/plat-omap/omap_device.c
>> +++ b/arch/arm/plat-omap/omap_device.c
>> @@ -100,6 +100,8 @@
>>  # error Unknown OMAP device
>>  #endif
>>  
>> +#define OMAP_DEVICE_MAGIC 0xf00dcafe
>> +
>>  /* Private functions */
>>  
>>  /**
>> @@ -413,6 +415,8 @@ struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
>>  	od->pm_lats = pm_lats;
>>  	od->pm_lats_cnt = pm_lats_cnt;
>>  
>> +	od->magic = OMAP_DEVICE_MAGIC;
>> +
>>  	ret = omap_device_register(od);
>>  	if (ret)
>>  		goto odbs_exit4;
>> @@ -599,6 +603,18 @@ int omap_device_align_pm_lat(struct platform_device *pdev,
>>  }
>>  
>>  /**
>> + * omap_device_is_valid()
>
> I think kerneldoc will want a short description after the function name.  
> Can plug this in here during the merge process if you want...

done, updated version below.

Thanks for comments,

Kevin

>From cd8cfaf6663da00645eca7bcf8f2faf1d5b96cf2 Mon Sep 17 00:00:00 2001
From: Kevin Hilman <khilman@deeprootsystems.com>
Date: Tue, 12 Jan 2010 16:37:47 -0800
Subject: [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid()

The omap_device struct contains a 'struct platform_device'.  Normally,
converting a platform_device pointer to an omap_device pointer
consists of simply doing a container_of(), as is done currently by the
to_omap_device() macro.

However, if this is attempted when using platform_device that has not
been created as part of the omap_device creation, the container_of()
will point to a memory location before the platform_device pointer
which will contain random data.

Therefore, we need a way to detect valid omap_device pointers.  This
patch solves this by using the simple magic number approach.

Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>
---
 arch/arm/plat-omap/include/plat/omap_device.h |    2 ++
 arch/arm/plat-omap/omap_device.c              |   16 ++++++++++++++++
 2 files changed, 18 insertions(+), 0 deletions(-)

diff --git a/arch/arm/plat-omap/include/plat/omap_device.h b/arch/arm/plat-omap/include/plat/omap_device.h
index 76d4917..4677ff7 100644
--- a/arch/arm/plat-omap/include/plat/omap_device.h
+++ b/arch/arm/plat-omap/include/plat/omap_device.h
@@ -62,6 +62,7 @@
  *
  */
 struct omap_device {
+	u32                             magic;
 	struct platform_device		pdev;
 	struct omap_hwmod		**hwmods;
 	struct omap_device_pm_latency	*pm_lats;
@@ -81,6 +82,7 @@ int omap_device_shutdown(struct platform_device *pdev);
 
 /* Core code interface */
 
+bool omap_device_is_valid(struct omap_device *od);
 int omap_device_count_resources(struct omap_device *od);
 int omap_device_fill_resources(struct omap_device *od, struct resource *res);
 
diff --git a/arch/arm/plat-omap/omap_device.c b/arch/arm/plat-omap/omap_device.c
index d6b593d..ec0bcca 100644
--- a/arch/arm/plat-omap/omap_device.c
+++ b/arch/arm/plat-omap/omap_device.c
@@ -100,6 +100,8 @@
 # error Unknown OMAP device
 #endif
 
+#define OMAP_DEVICE_MAGIC 0xf00dcafe
+
 /* Private functions */
 
 /**
@@ -413,6 +415,8 @@ struct omap_device *omap_device_build_ss(const char *pdev_name, int pdev_id,
 	od->pm_lats = pm_lats;
 	od->pm_lats_cnt = pm_lats_cnt;
 
+	od->magic = OMAP_DEVICE_MAGIC;
+
 	ret = omap_device_register(od);
 	if (ret)
 		goto odbs_exit4;
@@ -599,6 +603,18 @@ int omap_device_align_pm_lat(struct platform_device *pdev,
 }
 
 /**
+ * omap_device_is_valid - Check if pointer is a valid omap_device
+ * @od: struct omap_device *
+ *
+ * Return whether struct omap_device pointer @od points to a valid
+ * omap_device.
+ */
+bool omap_device_is_valid(struct omap_device *od)
+{
+	return (od && od->magic == OMAP_DEVICE_MAGIC);
+}
+
+/**
  * omap_device_get_pwrdm - return the powerdomain * associated with @od
  * @od: struct omap_device *
  *
-- 
1.6.6


^ permalink raw reply related	[flat|nested] 6+ messages in thread

* Re: [PATCH 2/2] OMAP: omap_device: when 'called from invalid state', print state
  2010-01-26 19:00 ` [PATCH 2/2] OMAP: omap_device: when 'called from invalid state', print state Kevin Hilman
@ 2010-02-11  7:17   ` Paul Walmsley
  0 siblings, 0 replies; 6+ messages in thread
From: Paul Walmsley @ 2010-02-11  7:17 UTC (permalink / raw)
  To: Kevin Hilman; +Cc: linux-omap

On Tue, 26 Jan 2010, Kevin Hilman wrote:

> The omap_device_[enable|idle|shutdown] functions print a warning
> when called from an invalid state.  Print the invalid state in
> the warning messages.  This also uses __func__ to get the function
> name.
> 
> Also, move the entire print string onto a single line to facilitate
> grepping or error messages.  Recent discussions on LKML show
> strong preference for grep-able code vs. strict 80 column limit.
> 
> Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>

Thanks, queued for 2.6.34.


- Paul

^ permalink raw reply	[flat|nested] 6+ messages in thread

* Re: [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid()
  2010-01-28 17:19   ` Kevin Hilman
@ 2010-02-21  8:35     ` Paul Walmsley
  0 siblings, 0 replies; 6+ messages in thread
From: Paul Walmsley @ 2010-02-21  8:35 UTC (permalink / raw)
  To: Kevin Hilman; +Cc: linux-omap

Hi Kevin,

On Thu, 28 Jan 2010, Kevin Hilman wrote:

> Hmm, not sure I follow...  
> 
> struct omap_device already contains a struct platform_device, which in
> turn contains a struct device, so to get an omap_device from a struct
> device, there are two container of operaions: to_platform_device() and
> to_omap_device()
> 
> 
> from omap_device.h:
> 
> struct omap_device {
> 	u32                             magic;
> 	struct platform_device		pdev;
>         [...]
> }
> #define to_omap_device(x) container_of((x), struct omap_device, pdev)
> 
> from platform_device.h:
> struct platform_device {
> 	const char	* name;
> 	int		id;
> 	struct device	dev;
>         [...]
> }
> #define to_platform_device(x) container_of((x), struct platform_device, dev)

Sorry - my E-mail was too hasty and unclear.  What I had in mind was the 
lifecycle aspect of omap_device - i.e., ensuring that omap_devices are 
automatically freed by the device core, similar to the way that 
platform_device_alloc() does it.


- Paul

^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2010-02-21  8:35 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2010-01-26 19:00 [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid() Kevin Hilman
2010-01-26 19:00 ` [PATCH 2/2] OMAP: omap_device: when 'called from invalid state', print state Kevin Hilman
2010-02-11  7:17   ` Paul Walmsley
2010-01-28  0:30 ` [PATCH 1/2] OMAP: omap_device: add omap_device_is_valid() Paul Walmsley
2010-01-28 17:19   ` Kevin Hilman
2010-02-21  8:35     ` Paul Walmsley

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).