[PATCH] staging: bcm2835-camera: Replace open-coded idr with a struct idr.

[PATCH] staging: bcm2835-camera: Replace open-coded idr with a struct idr.

[Eric Anholt]

We just need some integer handles that can map back to our message
struct when we're handling a reply, which struct idr is perfect for.

Signed-off-by: Eric Anholt <eric@anholt.net>
---
 .../vc04_services/bcm2835-camera/mmal-vchiq.c | 135 ++++--------------
 1 file changed, 31 insertions(+), 104 deletions(-)

diff --git a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
index 3a3b843fc122..f0dac6440cfb 100644
--- a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
+++ b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
@@ -21,7 +21,6 @@
 #include <linux/slab.h>
 #include <linux/completion.h>
 #include <linux/vmalloc.h>
-#include <linux/btree.h>
 #include <asm/cacheflush.h>
 #include <media/videobuf2-vmalloc.h>
 
@@ -111,7 +110,11 @@ struct vchiq_mmal_instance;
 /* normal message context */
 struct mmal_msg_context {
 	struct vchiq_mmal_instance *instance;
-	u32 handle;
+
+	/* Index in the context_map idr so that we can find the
+	 * mmal_msg_context again when servicing the VCHI reply.
+	 */
+	int handle;
 
 	union {
 		struct {
@@ -149,13 +152,6 @@ struct mmal_msg_context {
 
 };
 
-struct vchiq_mmal_context_map {
-	/* ensure serialized access to the btree(contention should be low) */
-	struct mutex lock;
-	struct btree_head32 btree_head;
-	u32 last_handle;
-};
-
 struct vchiq_mmal_instance {
 	VCHI_SERVICE_HANDLE_T handle;
 
@@ -165,92 +161,19 @@ struct vchiq_mmal_instance {
 	/* vmalloc page to receive scratch bulk xfers into */
 	void *bulk_scratch;
 
-	/* mapping table between context handles and mmal_msg_contexts */
-	struct vchiq_mmal_context_map context_map;
+	struct idr context_map;
+	spinlock_t context_map_lock;
 
 	/* component to use next */
 	int component_idx;
 	struct vchiq_mmal_component component[VCHIQ_MMAL_MAX_COMPONENTS];
 };
 
-static int __must_check
-mmal_context_map_init(struct vchiq_mmal_context_map *context_map)
-{
-	mutex_init(&context_map->lock);
-	context_map->last_handle = 0;
-	return btree_init32(&context_map->btree_head);
-}
-
-static void mmal_context_map_destroy(struct vchiq_mmal_context_map *context_map)
-{
-	mutex_lock(&context_map->lock);
-	btree_destroy32(&context_map->btree_head);
-	mutex_unlock(&context_map->lock);
-}
-
-static u32
-mmal_context_map_create_handle(struct vchiq_mmal_context_map *context_map,
-			       struct mmal_msg_context *msg_context,
-			       gfp_t gfp)
-{
-	u32 handle;
-
-	mutex_lock(&context_map->lock);
-
-	while (1) {
-		/* just use a simple count for handles, but do not use 0 */
-		context_map->last_handle++;
-		if (!context_map->last_handle)
-			context_map->last_handle++;
-
-		handle = context_map->last_handle;
-
-		/* check if the handle is already in use */
-		if (!btree_lookup32(&context_map->btree_head, handle))
-			break;
-	}
-
-	if (btree_insert32(&context_map->btree_head, handle,
-			   msg_context, gfp)) {
-		/* probably out of memory */
-		mutex_unlock(&context_map->lock);
-		return 0;
-	}
-
-	mutex_unlock(&context_map->lock);
-	return handle;
-}
-
-static struct mmal_msg_context *
-mmal_context_map_lookup_handle(struct vchiq_mmal_context_map *context_map,
-			       u32 handle)
-{
-	struct mmal_msg_context *msg_context;
-
-	if (!handle)
-		return NULL;
-
-	mutex_lock(&context_map->lock);
-
-	msg_context = btree_lookup32(&context_map->btree_head, handle);
-
-	mutex_unlock(&context_map->lock);
-	return msg_context;
-}
-
-static void
-mmal_context_map_destroy_handle(struct vchiq_mmal_context_map *context_map,
-				u32 handle)
-{
-	mutex_lock(&context_map->lock);
-	btree_remove32(&context_map->btree_head, handle);
-	mutex_unlock(&context_map->lock);
-}
-
 static struct mmal_msg_context *
 get_msg_context(struct vchiq_mmal_instance *instance)
 {
 	struct mmal_msg_context *msg_context;
+	int handle;
 
 	/* todo: should this be allocated from a pool to avoid kzalloc */
 	msg_context = kzalloc(sizeof(*msg_context), GFP_KERNEL);
@@ -258,32 +181,40 @@ get_msg_context(struct vchiq_mmal_instance *instance)
 	if (!msg_context)
 		return ERR_PTR(-ENOMEM);
 
-	msg_context->instance = instance;
-	msg_context->handle =
-		mmal_context_map_create_handle(&instance->context_map,
-					       msg_context,
-					       GFP_KERNEL);
+	/* Create an ID that will be passed along with our message so
+	 * that when we service the VCHI reply, we can look up what
+	 * message is being replied to.
+	 */
+	spin_lock(&instance->context_map_lock);
+	handle = idr_alloc(&instance->context_map, msg_context,
+			   0, 0, GFP_KERNEL);
+	spin_unlock(&instance->context_map_lock);
 
-	if (!msg_context->handle) {
+	if (msg_context->handle < 0) {
 		kfree(msg_context);
-		return ERR_PTR(-ENOMEM);
+		return ERR_PTR(handle);
 	}
 
+	msg_context->instance = instance;
+	msg_context->handle = handle;
+
 	return msg_context;
 }
 
 static struct mmal_msg_context *
-lookup_msg_context(struct vchiq_mmal_instance *instance, u32 handle)
+lookup_msg_context(struct vchiq_mmal_instance *instance, int handle)
 {
-	return mmal_context_map_lookup_handle(&instance->context_map,
-		handle);
+	return idr_find(&instance->context_map, handle);
 }
 
 static void
 release_msg_context(struct mmal_msg_context *msg_context)
 {
-	mmal_context_map_destroy_handle(&msg_context->instance->context_map,
-					msg_context->handle);
+	struct vchiq_mmal_instance *instance = msg_context->instance;
+
+	spin_lock(&instance->context_map_lock);
+	idr_remove(&instance->context_map, msg_context->handle);
+	spin_unlock(&instance->context_map_lock);
 	kfree(msg_context);
 }
 
@@ -1860,7 +1791,7 @@ int vchiq_mmal_finalise(struct vchiq_mmal_instance *instance)
 
 	vfree(instance->bulk_scratch);
 
-	mmal_context_map_destroy(&instance->context_map);
+	idr_destroy(&instance->context_map);
 
 	kfree(instance);
 
@@ -1922,12 +1853,8 @@ int vchiq_mmal_init(struct vchiq_mmal_instance **out_instance)
 
 	instance->bulk_scratch = vmalloc(PAGE_SIZE);
 
-	status = mmal_context_map_init(&instance->context_map);
-	if (status) {
-		pr_err("Failed to init context map (status=%d)\n", status);
-		kfree(instance);
-		return status;
-	}
+	spin_lock_init(&instance->context_map_lock);
+	idr_init_base(&instance->context_map, 1);
 
 	params.callback_param = instance;
 
-- 
2.17.0

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Re: [PATCH] staging: bcm2835-camera: Replace open-coded idr with a struct idr.

[Stefan Wahren]

Hi Eric,

> Eric Anholt <eric@anholt.net> hat am 11. Mai 2018 um 01:31 geschrieben:
> 
> 
> We just need some integer handles that can map back to our message
> struct when we're handling a reply, which struct idr is perfect for.
> 
> Signed-off-by: Eric Anholt <eric@anholt.net>
> ---
>  .../vc04_services/bcm2835-camera/mmal-vchiq.c | 135 ++++--------------
>  1 file changed, 31 insertions(+), 104 deletions(-)
> 
> diff --git a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
> index 3a3b843fc122..f0dac6440cfb 100644
> --- a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
> +++ b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
> @@ -21,7 +21,6 @@
>  #include <linux/slab.h>
>  #include <linux/completion.h>
>  #include <linux/vmalloc.h>
> -#include <linux/btree.h>
>  #include <asm/cacheflush.h>
>  #include <media/videobuf2-vmalloc.h>
>  
> @@ -111,7 +110,11 @@ struct vchiq_mmal_instance;
>  /* normal message context */
>  struct mmal_msg_context {
>  	struct vchiq_mmal_instance *instance;
> -	u32 handle;
> +
> +	/* Index in the context_map idr so that we can find the
> +	 * mmal_msg_context again when servicing the VCHI reply.
> +	 */
> +	int handle;
>  
>  	union {
>  		struct {
> @@ -149,13 +152,6 @@ struct mmal_msg_context {
>  
>  };
>  
> -struct vchiq_mmal_context_map {
> -	/* ensure serialized access to the btree(contention should be low) */
> -	struct mutex lock;
> -	struct btree_head32 btree_head;
> -	u32 last_handle;
> -};
> -
>  struct vchiq_mmal_instance {
>  	VCHI_SERVICE_HANDLE_T handle;
>  
> @@ -165,92 +161,19 @@ struct vchiq_mmal_instance {
>  	/* vmalloc page to receive scratch bulk xfers into */
>  	void *bulk_scratch;
>  
> -	/* mapping table between context handles and mmal_msg_contexts */
> -	struct vchiq_mmal_context_map context_map;
> +	struct idr context_map;
> +	spinlock_t context_map_lock;
>  
>  	/* component to use next */
>  	int component_idx;
>  	struct vchiq_mmal_component component[VCHIQ_MMAL_MAX_COMPONENTS];
>  };
>  
> -static int __must_check
> -mmal_context_map_init(struct vchiq_mmal_context_map *context_map)
> -{
> -	mutex_init(&context_map->lock);
> -	context_map->last_handle = 0;
> -	return btree_init32(&context_map->btree_head);
> -}
> -
> -static void mmal_context_map_destroy(struct vchiq_mmal_context_map *context_map)
> -{
> -	mutex_lock(&context_map->lock);
> -	btree_destroy32(&context_map->btree_head);
> -	mutex_unlock(&context_map->lock);
> -}
> -
> -static u32
> -mmal_context_map_create_handle(struct vchiq_mmal_context_map *context_map,
> -			       struct mmal_msg_context *msg_context,
> -			       gfp_t gfp)
> -{
> -	u32 handle;
> -
> -	mutex_lock(&context_map->lock);
> -
> -	while (1) {
> -		/* just use a simple count for handles, but do not use 0 */
> -		context_map->last_handle++;
> -		if (!context_map->last_handle)
> -			context_map->last_handle++;
> -
> -		handle = context_map->last_handle;
> -
> -		/* check if the handle is already in use */
> -		if (!btree_lookup32(&context_map->btree_head, handle))
> -			break;
> -	}
> -
> -	if (btree_insert32(&context_map->btree_head, handle,
> -			   msg_context, gfp)) {
> -		/* probably out of memory */
> -		mutex_unlock(&context_map->lock);
> -		return 0;
> -	}
> -
> -	mutex_unlock(&context_map->lock);
> -	return handle;
> -}
> -
> -static struct mmal_msg_context *
> -mmal_context_map_lookup_handle(struct vchiq_mmal_context_map *context_map,
> -			       u32 handle)
> -{
> -	struct mmal_msg_context *msg_context;
> -
> -	if (!handle)
> -		return NULL;
> -
> -	mutex_lock(&context_map->lock);
> -
> -	msg_context = btree_lookup32(&context_map->btree_head, handle);
> -
> -	mutex_unlock(&context_map->lock);
> -	return msg_context;
> -}
> -
> -static void
> -mmal_context_map_destroy_handle(struct vchiq_mmal_context_map *context_map,
> -				u32 handle)
> -{
> -	mutex_lock(&context_map->lock);
> -	btree_remove32(&context_map->btree_head, handle);
> -	mutex_unlock(&context_map->lock);
> -}
> -
>  static struct mmal_msg_context *
>  get_msg_context(struct vchiq_mmal_instance *instance)
>  {
>  	struct mmal_msg_context *msg_context;
> +	int handle;
>  
>  	/* todo: should this be allocated from a pool to avoid kzalloc */
>  	msg_context = kzalloc(sizeof(*msg_context), GFP_KERNEL);
> @@ -258,32 +181,40 @@ get_msg_context(struct vchiq_mmal_instance *instance)
>  	if (!msg_context)
>  		return ERR_PTR(-ENOMEM);
>  
> -	msg_context->instance = instance;
> -	msg_context->handle =
> -		mmal_context_map_create_handle(&instance->context_map,
> -					       msg_context,
> -					       GFP_KERNEL);
> +	/* Create an ID that will be passed along with our message so
> +	 * that when we service the VCHI reply, we can look up what
> +	 * message is being replied to.
> +	 */
> +	spin_lock(&instance->context_map_lock);
> +	handle = idr_alloc(&instance->context_map, msg_context,
> +			   0, 0, GFP_KERNEL);
> +	spin_unlock(&instance->context_map_lock);
>  
> -	if (!msg_context->handle) {
> +	if (msg_context->handle < 0) {

handle < 0 ?

>  		kfree(msg_context);
> -		return ERR_PTR(-ENOMEM);
> +		return ERR_PTR(handle);
>  	}
>  
> +	msg_context->instance = instance;
> +	msg_context->handle = handle;
> +
>  	return msg_context;
>  }
>  

Regards
Stefan
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Re: [PATCH] staging: bcm2835-camera: Replace open-coded idr with a struct idr.

[Eric Anholt]

[-- Attachment #1.1: Type: text/plain, Size: 5497 bytes --]

Stefan Wahren <stefan.wahren@i2se.com> writes:

> Hi Eric,
>
>> Eric Anholt <eric@anholt.net> hat am 11. Mai 2018 um 01:31 geschrieben:
>> 
>> 
>> We just need some integer handles that can map back to our message
>> struct when we're handling a reply, which struct idr is perfect for.
>> 
>> Signed-off-by: Eric Anholt <eric@anholt.net>
>> ---
>>  .../vc04_services/bcm2835-camera/mmal-vchiq.c | 135 ++++--------------
>>  1 file changed, 31 insertions(+), 104 deletions(-)
>> 
>> diff --git a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
>> index 3a3b843fc122..f0dac6440cfb 100644
>> --- a/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
>> +++ b/drivers/staging/vc04_services/bcm2835-camera/mmal-vchiq.c
>> @@ -21,7 +21,6 @@
>>  #include <linux/slab.h>
>>  #include <linux/completion.h>
>>  #include <linux/vmalloc.h>
>> -#include <linux/btree.h>
>>  #include <asm/cacheflush.h>
>>  #include <media/videobuf2-vmalloc.h>
>>  
>> @@ -111,7 +110,11 @@ struct vchiq_mmal_instance;
>>  /* normal message context */
>>  struct mmal_msg_context {
>>  	struct vchiq_mmal_instance *instance;
>> -	u32 handle;
>> +
>> +	/* Index in the context_map idr so that we can find the
>> +	 * mmal_msg_context again when servicing the VCHI reply.
>> +	 */
>> +	int handle;
>>  
>>  	union {
>>  		struct {
>> @@ -149,13 +152,6 @@ struct mmal_msg_context {
>>  
>>  };
>>  
>> -struct vchiq_mmal_context_map {
>> -	/* ensure serialized access to the btree(contention should be low) */
>> -	struct mutex lock;
>> -	struct btree_head32 btree_head;
>> -	u32 last_handle;
>> -};
>> -
>>  struct vchiq_mmal_instance {
>>  	VCHI_SERVICE_HANDLE_T handle;
>>  
>> @@ -165,92 +161,19 @@ struct vchiq_mmal_instance {
>>  	/* vmalloc page to receive scratch bulk xfers into */
>>  	void *bulk_scratch;
>>  
>> -	/* mapping table between context handles and mmal_msg_contexts */
>> -	struct vchiq_mmal_context_map context_map;
>> +	struct idr context_map;
>> +	spinlock_t context_map_lock;
>>  
>>  	/* component to use next */
>>  	int component_idx;
>>  	struct vchiq_mmal_component component[VCHIQ_MMAL_MAX_COMPONENTS];
>>  };
>>  
>> -static int __must_check
>> -mmal_context_map_init(struct vchiq_mmal_context_map *context_map)
>> -{
>> -	mutex_init(&context_map->lock);
>> -	context_map->last_handle = 0;
>> -	return btree_init32(&context_map->btree_head);
>> -}
>> -
>> -static void mmal_context_map_destroy(struct vchiq_mmal_context_map *context_map)
>> -{
>> -	mutex_lock(&context_map->lock);
>> -	btree_destroy32(&context_map->btree_head);
>> -	mutex_unlock(&context_map->lock);
>> -}
>> -
>> -static u32
>> -mmal_context_map_create_handle(struct vchiq_mmal_context_map *context_map,
>> -			       struct mmal_msg_context *msg_context,
>> -			       gfp_t gfp)
>> -{
>> -	u32 handle;
>> -
>> -	mutex_lock(&context_map->lock);
>> -
>> -	while (1) {
>> -		/* just use a simple count for handles, but do not use 0 */
>> -		context_map->last_handle++;
>> -		if (!context_map->last_handle)
>> -			context_map->last_handle++;
>> -
>> -		handle = context_map->last_handle;
>> -
>> -		/* check if the handle is already in use */
>> -		if (!btree_lookup32(&context_map->btree_head, handle))
>> -			break;
>> -	}
>> -
>> -	if (btree_insert32(&context_map->btree_head, handle,
>> -			   msg_context, gfp)) {
>> -		/* probably out of memory */
>> -		mutex_unlock(&context_map->lock);
>> -		return 0;
>> -	}
>> -
>> -	mutex_unlock(&context_map->lock);
>> -	return handle;
>> -}
>> -
>> -static struct mmal_msg_context *
>> -mmal_context_map_lookup_handle(struct vchiq_mmal_context_map *context_map,
>> -			       u32 handle)
>> -{
>> -	struct mmal_msg_context *msg_context;
>> -
>> -	if (!handle)
>> -		return NULL;
>> -
>> -	mutex_lock(&context_map->lock);
>> -
>> -	msg_context = btree_lookup32(&context_map->btree_head, handle);
>> -
>> -	mutex_unlock(&context_map->lock);
>> -	return msg_context;
>> -}
>> -
>> -static void
>> -mmal_context_map_destroy_handle(struct vchiq_mmal_context_map *context_map,
>> -				u32 handle)
>> -{
>> -	mutex_lock(&context_map->lock);
>> -	btree_remove32(&context_map->btree_head, handle);
>> -	mutex_unlock(&context_map->lock);
>> -}
>> -
>>  static struct mmal_msg_context *
>>  get_msg_context(struct vchiq_mmal_instance *instance)
>>  {
>>  	struct mmal_msg_context *msg_context;
>> +	int handle;
>>  
>>  	/* todo: should this be allocated from a pool to avoid kzalloc */
>>  	msg_context = kzalloc(sizeof(*msg_context), GFP_KERNEL);
>> @@ -258,32 +181,40 @@ get_msg_context(struct vchiq_mmal_instance *instance)
>>  	if (!msg_context)
>>  		return ERR_PTR(-ENOMEM);
>>  
>> -	msg_context->instance = instance;
>> -	msg_context->handle =
>> -		mmal_context_map_create_handle(&instance->context_map,
>> -					       msg_context,
>> -					       GFP_KERNEL);
>> +	/* Create an ID that will be passed along with our message so
>> +	 * that when we service the VCHI reply, we can look up what
>> +	 * message is being replied to.
>> +	 */
>> +	spin_lock(&instance->context_map_lock);
>> +	handle = idr_alloc(&instance->context_map, msg_context,
>> +			   0, 0, GFP_KERNEL);
>> +	spin_unlock(&instance->context_map_lock);
>>  
>> -	if (!msg_context->handle) {
>> +	if (msg_context->handle < 0) {
>
> handle < 0 ?

You're right, thanks!

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Re: [PATCH] staging: bcm2835-camera: Replace open-coded idr with a struct idr.

[Dan Carpenter]

On Thu, May 10, 2018 at 04:31:07PM -0700, Eric Anholt wrote:
> @@ -258,32 +181,40 @@ get_msg_context(struct vchiq_mmal_instance *instance)
>  	if (!msg_context)
>  		return ERR_PTR(-ENOMEM);
>  
> -	msg_context->instance = instance;
> -	msg_context->handle =
> -		mmal_context_map_create_handle(&instance->context_map,
> -					       msg_context,
> -					       GFP_KERNEL);
> +	/* Create an ID that will be passed along with our message so
> +	 * that when we service the VCHI reply, we can look up what
> +	 * message is being replied to.
> +	 */
> +	spin_lock(&instance->context_map_lock);
> +	handle = idr_alloc(&instance->context_map, msg_context,
> +			   0, 0, GFP_KERNEL);
> +	spin_unlock(&instance->context_map_lock);
>  
> -	if (!msg_context->handle) {
> +	if (msg_context->handle < 0) {

This should probably be testing:

	if (handle < 0) {

>  		kfree(msg_context);
> -		return ERR_PTR(-ENOMEM);
> +		return ERR_PTR(handle);
>  	}
>  
> +	msg_context->instance = instance;
> +	msg_context->handle = handle;
> +
>  	return msg_context;
>  }
>  

Re: [PATCH] staging: bcm2835-camera: Replace open-coded idr with a struct idr.

[Eric Anholt]

[-- Attachment #1.1: Type: text/plain, Size: 1013 bytes --]

Dan Carpenter <dan.carpenter@oracle.com> writes:

> On Thu, May 10, 2018 at 04:31:07PM -0700, Eric Anholt wrote:
>> @@ -258,32 +181,40 @@ get_msg_context(struct vchiq_mmal_instance *instance)
>>  	if (!msg_context)
>>  		return ERR_PTR(-ENOMEM);
>>  
>> -	msg_context->instance = instance;
>> -	msg_context->handle =
>> -		mmal_context_map_create_handle(&instance->context_map,
>> -					       msg_context,
>> -					       GFP_KERNEL);
>> +	/* Create an ID that will be passed along with our message so
>> +	 * that when we service the VCHI reply, we can look up what
>> +	 * message is being replied to.
>> +	 */
>> +	spin_lock(&instance->context_map_lock);
>> +	handle = idr_alloc(&instance->context_map, msg_context,
>> +			   0, 0, GFP_KERNEL);
>> +	spin_unlock(&instance->context_map_lock);
>>  
>> -	if (!msg_context->handle) {
>> +	if (msg_context->handle < 0) {
>
> This should probably be testing:
>
> 	if (handle < 0) {

That's what Stefan said and was fixed in v2 already.

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