Re: [PATCH v3 06/19] drm/gpusvm: Make drm_gpusvm_for_each_* macros public

[Matthew Brost <matthew.brost@intel.com>]

On Tue, May 27, 2025 at 10:09:50PM +0530, Himal Prasad Ghimiray wrote:
> The drm_gpusvm_for_each_notifier, drm_gpusvm_for_each_notifier_safe and
> drm_gpusvm_for_each_range_safe macros are useful for locating notifiers
> and ranges within a user-specified range. By making these macros public,
> we enable broader access and utility for developers who need to leverage
> them in their implementations.
> 
> v2 (Matthew Brost)
> - drop inline __drm_gpusvm_range_find
> - /s/notifier_iter_first/drm_gpusvm_notifier_find
> 
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>

Reviewed-by: Matthew Brost <matthew.brost@intel.com>

> ---
>  drivers/gpu/drm/drm_gpusvm.c | 122 +++++++----------------------------
>  include/drm/drm_gpusvm.h     |  70 ++++++++++++++++++++
>  2 files changed, 95 insertions(+), 97 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_gpusvm.c b/drivers/gpu/drm/drm_gpusvm.c
> index 7bb9eb71c9aa..e50a25fe1079 100644
> --- a/drivers/gpu/drm/drm_gpusvm.c
> +++ b/drivers/gpu/drm/drm_gpusvm.c
> @@ -380,107 +380,50 @@ static void drm_gpusvm_zdd_put(struct drm_gpusvm_zdd *zdd)
>  }
>  
>  /**
> - * drm_gpusvm_range_find() - Find GPU SVM range from GPU SVM notifier
> - * @notifier: Pointer to the GPU SVM notifier structure.
> - * @start: Start address of the range
> - * @end: End address of the range
> + * drm_gpusvm_notifier_find() - Find GPU SVM notifier from GPU SVM
> + * @gpusvm: Pointer to the GPU SVM structure.
> + * @start: Start address of the notifier
> + * @end: End address of the notifier
>   *
> - * Return: A pointer to the drm_gpusvm_range if found or NULL
> + * Return: A pointer to the drm_gpusvm_notifier if found or NULL
>   */
> -struct drm_gpusvm_range *
> -drm_gpusvm_range_find(struct drm_gpusvm_notifier *notifier, unsigned long start,
> -		      unsigned long end)
> +struct drm_gpusvm_notifier *
> +drm_gpusvm_notifier_find(struct drm_gpusvm *gpusvm, unsigned long start,
> +			 unsigned long end)
>  {
>  	struct interval_tree_node *itree;
>  
> -	itree = interval_tree_iter_first(&notifier->root, start, end - 1);
> +	itree = interval_tree_iter_first(&gpusvm->root, start, end - 1);
>  
>  	if (itree)
> -		return container_of(itree, struct drm_gpusvm_range, itree);
> +		return container_of(itree, struct drm_gpusvm_notifier, itree);
>  	else
>  		return NULL;
>  }
> -EXPORT_SYMBOL_GPL(drm_gpusvm_range_find);
> +EXPORT_SYMBOL_GPL(drm_gpusvm_notifier_find);
>  
>  /**
> - * drm_gpusvm_for_each_range_safe() - Safely iterate over GPU SVM ranges in a notifier
> - * @range__: Iterator variable for the ranges
> - * @next__: Iterator variable for the ranges temporay storage
> - * @notifier__: Pointer to the GPU SVM notifier
> - * @start__: Start address of the range
> - * @end__: End address of the range
> - *
> - * This macro is used to iterate over GPU SVM ranges in a notifier while
> - * removing ranges from it.
> - */
> -#define drm_gpusvm_for_each_range_safe(range__, next__, notifier__, start__, end__)	\
> -	for ((range__) = drm_gpusvm_range_find((notifier__), (start__), (end__)),	\
> -	     (next__) = __drm_gpusvm_range_next(range__);				\
> -	     (range__) && (drm_gpusvm_range_start(range__) < (end__));			\
> -	     (range__) = (next__), (next__) = __drm_gpusvm_range_next(range__))
> -
> -/**
> - * __drm_gpusvm_notifier_next() - get the next drm_gpusvm_notifier in the list
> - * @notifier: a pointer to the current drm_gpusvm_notifier
> + * drm_gpusvm_range_find() - Find GPU SVM range from GPU SVM notifier
> + * @notifier: Pointer to the GPU SVM notifier structure.
> + * @start: Start address of the range
> + * @end: End address of the range
>   *
> - * Return: A pointer to the next drm_gpusvm_notifier if available, or NULL if
> - *         the current notifier is the last one or if the input notifier is
> - *         NULL.
> + * Return: A pointer to the drm_gpusvm_range if found or NULL
>   */
> -static struct drm_gpusvm_notifier *
> -__drm_gpusvm_notifier_next(struct drm_gpusvm_notifier *notifier)
> -{
> -	if (notifier && !list_is_last(&notifier->entry,
> -				      &notifier->gpusvm->notifier_list))
> -		return list_next_entry(notifier, entry);
> -
> -	return NULL;
> -}
> -
> -static struct drm_gpusvm_notifier *
> -notifier_iter_first(struct rb_root_cached *root, unsigned long start,
> -		    unsigned long last)
> +struct drm_gpusvm_range *
> +drm_gpusvm_range_find(struct drm_gpusvm_notifier *notifier, unsigned long start,
> +		      unsigned long end)
>  {
>  	struct interval_tree_node *itree;
>  
> -	itree = interval_tree_iter_first(root, start, last);
> +	itree = interval_tree_iter_first(&notifier->root, start, end - 1);
>  
>  	if (itree)
> -		return container_of(itree, struct drm_gpusvm_notifier, itree);
> +		return container_of(itree, struct drm_gpusvm_range, itree);
>  	else
>  		return NULL;
>  }
> -
> -/**
> - * drm_gpusvm_for_each_notifier() - Iterate over GPU SVM notifiers in a gpusvm
> - * @notifier__: Iterator variable for the notifiers
> - * @notifier__: Pointer to the GPU SVM notifier
> - * @start__: Start address of the notifier
> - * @end__: End address of the notifier
> - *
> - * This macro is used to iterate over GPU SVM notifiers in a gpusvm.
> - */
> -#define drm_gpusvm_for_each_notifier(notifier__, gpusvm__, start__, end__)		\
> -	for ((notifier__) = notifier_iter_first(&(gpusvm__)->root, (start__), (end__) - 1);	\
> -	     (notifier__) && (drm_gpusvm_notifier_start(notifier__) < (end__));		\
> -	     (notifier__) = __drm_gpusvm_notifier_next(notifier__))
> -
> -/**
> - * drm_gpusvm_for_each_notifier_safe() - Safely iterate over GPU SVM notifiers in a gpusvm
> - * @notifier__: Iterator variable for the notifiers
> - * @next__: Iterator variable for the notifiers temporay storage
> - * @notifier__: Pointer to the GPU SVM notifier
> - * @start__: Start address of the notifier
> - * @end__: End address of the notifier
> - *
> - * This macro is used to iterate over GPU SVM notifiers in a gpusvm while
> - * removing notifiers from it.
> - */
> -#define drm_gpusvm_for_each_notifier_safe(notifier__, next__, gpusvm__, start__, end__)	\
> -	for ((notifier__) = notifier_iter_first(&(gpusvm__)->root, (start__), (end__) - 1),	\
> -	     (next__) = __drm_gpusvm_notifier_next(notifier__);				\
> -	     (notifier__) && (drm_gpusvm_notifier_start(notifier__) < (end__));		\
> -	     (notifier__) = (next__), (next__) = __drm_gpusvm_notifier_next(notifier__))
> +EXPORT_SYMBOL_GPL(drm_gpusvm_range_find);
>  
>  /**
>   * drm_gpusvm_notifier_invalidate() - Invalidate a GPU SVM notifier.
> @@ -581,22 +524,6 @@ int drm_gpusvm_init(struct drm_gpusvm *gpusvm,
>  }
>  EXPORT_SYMBOL_GPL(drm_gpusvm_init);
>  
> -/**
> - * drm_gpusvm_notifier_find() - Find GPU SVM notifier
> - * @gpusvm: Pointer to the GPU SVM structure
> - * @fault_addr: Fault address
> - *
> - * This function finds the GPU SVM notifier associated with the fault address.
> - *
> - * Return: Pointer to the GPU SVM notifier on success, NULL otherwise.
> - */
> -static struct drm_gpusvm_notifier *
> -drm_gpusvm_notifier_find(struct drm_gpusvm *gpusvm,
> -			 unsigned long fault_addr)
> -{
> -	return notifier_iter_first(&gpusvm->root, fault_addr, fault_addr + 1);
> -}
> -
>  /**
>   * to_drm_gpusvm_notifier() - retrieve the container struct for a given rbtree node
>   * @node: a pointer to the rbtree node embedded within a drm_gpusvm_notifier struct
> @@ -1052,7 +979,7 @@ drm_gpusvm_range_find_or_insert(struct drm_gpusvm *gpusvm,
>  	if (!mmget_not_zero(mm))
>  		return ERR_PTR(-EFAULT);
>  
> -	notifier = drm_gpusvm_notifier_find(gpusvm, fault_addr);
> +	notifier = drm_gpusvm_notifier_find(gpusvm, fault_addr, fault_addr + 1);
>  	if (!notifier) {
>  		notifier = drm_gpusvm_notifier_alloc(gpusvm, fault_addr);
>  		if (IS_ERR(notifier)) {
> @@ -1216,7 +1143,8 @@ void drm_gpusvm_range_remove(struct drm_gpusvm *gpusvm,
>  	drm_gpusvm_driver_lock_held(gpusvm);
>  
>  	notifier = drm_gpusvm_notifier_find(gpusvm,
> -					    drm_gpusvm_range_start(range));
> +					    drm_gpusvm_range_start(range),
> +					    drm_gpusvm_range_start(range) + 1);
>  	if (WARN_ON_ONCE(!notifier))
>  		return;
>  
> diff --git a/include/drm/drm_gpusvm.h b/include/drm/drm_gpusvm.h
> index 6a5156476bf4..cdd89e5af4f8 100644
> --- a/include/drm/drm_gpusvm.h
> +++ b/include/drm/drm_gpusvm.h
> @@ -373,6 +373,10 @@ const struct dev_pagemap_ops *drm_gpusvm_pagemap_ops_get(void);
>  bool drm_gpusvm_has_mapping(struct drm_gpusvm *gpusvm, unsigned long start,
>  			    unsigned long end);
>  
> +struct drm_gpusvm_notifier *
> +drm_gpusvm_notifier_find(struct drm_gpusvm *gpusvm, unsigned long start,
> +			 unsigned long end);
> +
>  struct drm_gpusvm_range *
>  drm_gpusvm_range_find(struct drm_gpusvm_notifier *notifier, unsigned long start,
>  		      unsigned long end);
> @@ -530,4 +534,70 @@ __drm_gpusvm_range_next(struct drm_gpusvm_range *range)
>  	     (range__) && (drm_gpusvm_range_start(range__) < (end__));	\
>  	     (range__) = __drm_gpusvm_range_next(range__))
>  
> +/**
> + * drm_gpusvm_for_each_range_safe() - Safely iterate over GPU SVM ranges in a notifier
> + * @range__: Iterator variable for the ranges
> + * @next__: Iterator variable for the ranges temporay storage
> + * @notifier__: Pointer to the GPU SVM notifier
> + * @start__: Start address of the range
> + * @end__: End address of the range
> + *
> + * This macro is used to iterate over GPU SVM ranges in a notifier while
> + * removing ranges from it.
> + */
> +#define drm_gpusvm_for_each_range_safe(range__, next__, notifier__, start__, end__)	\
> +	for ((range__) = drm_gpusvm_range_find((notifier__), (start__), (end__)),	\
> +	     (next__) = __drm_gpusvm_range_next(range__);				\
> +	     (range__) && (drm_gpusvm_range_start(range__) < (end__));			\
> +	     (range__) = (next__), (next__) = __drm_gpusvm_range_next(range__))
> +
> +/**
> + * __drm_gpusvm_notifier_next() - get the next drm_gpusvm_notifier in the list
> + * @notifier: a pointer to the current drm_gpusvm_notifier
> + *
> + * Return: A pointer to the next drm_gpusvm_notifier if available, or NULL if
> + *         the current notifier is the last one or if the input notifier is
> + *         NULL.
> + */
> +static inline struct drm_gpusvm_notifier *
> +__drm_gpusvm_notifier_next(struct drm_gpusvm_notifier *notifier)
> +{
> +	if (notifier && !list_is_last(&notifier->entry,
> +				      &notifier->gpusvm->notifier_list))
> +		return list_next_entry(notifier, entry);
> +
> +	return NULL;
> +}
> +
> +/**
> + * drm_gpusvm_for_each_notifier() - Iterate over GPU SVM notifiers in a gpusvm
> + * @notifier__: Iterator variable for the notifiers
> + * @gpusvm__: Pointer to the GPU SVM notifier
> + * @start__: Start address of the notifier
> + * @end__: End address of the notifier
> + *
> + * This macro is used to iterate over GPU SVM notifiers in a gpusvm.
> + */
> +#define drm_gpusvm_for_each_notifier(notifier__, gpusvm__, start__, end__)		\
> +	for ((notifier__) = drm_gpusvm_notifier_find((gpusvm__), (start__), (end__));	\
> +	     (notifier__) && (drm_gpusvm_notifier_start(notifier__) < (end__));		\
> +	     (notifier__) = __drm_gpusvm_notifier_next(notifier__))
> +
> +/**
> + * drm_gpusvm_for_each_notifier_safe() - Safely iterate over GPU SVM notifiers in a gpusvm
> + * @notifier__: Iterator variable for the notifiers
> + * @next__: Iterator variable for the notifiers temporay storage
> + * @gpusvm__: Pointer to the GPU SVM notifier
> + * @start__: Start address of the notifier
> + * @end__: End address of the notifier
> + *
> + * This macro is used to iterate over GPU SVM notifiers in a gpusvm while
> + * removing notifiers from it.
> + */
> +#define drm_gpusvm_for_each_notifier_safe(notifier__, next__, gpusvm__, start__, end__)	\
> +	for ((notifier__) = drm_gpusvm_notifier_find((gpusvm__), (start__), (end__)),	\
> +	     (next__) = __drm_gpusvm_notifier_next(notifier__);				\
> +	     (notifier__) && (drm_gpusvm_notifier_start(notifier__) < (end__));		\
> +	     (notifier__) = (next__), (next__) = __drm_gpusvm_notifier_next(notifier__))
> +
>  #endif /* __DRM_GPUSVM_H__ */
> -- 
> 2.34.1
>