Re: [RFC PATCH v2] drm/ttm: Try to check if new ttm man out of bounds during compile

[Christian König <christian.koenig@xxxxxxx>]

Am 13.09.21 um 10:09 schrieb xinhui pan:
> Allow TTM know if vendor set new ttm mananger out of bounds by adding
> build_bug_on.
>
> Signed-off-by: xinhui pan <xinhui.pan@xxxxxxx>

Yeah, that looks better. Reviewed-by: Christian König 
<christian.koenig@xxxxxxx>

Going to push that to drm-misc-next.

Thanks,
Christian.

> ---
>   drivers/gpu/drm/ttm/ttm_range_manager.c |  8 ++++----
>   include/drm/ttm/ttm_device.h            |  3 +++
>   include/drm/ttm/ttm_range_manager.h     | 18 ++++++++++++++++--
>   3 files changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_range_manager.c b/drivers/gpu/drm/ttm/ttm_range_manager.c
> index 03395386e8a7..f2d702b66749 100644
> --- a/drivers/gpu/drm/ttm/ttm_range_manager.c
> +++ b/drivers/gpu/drm/ttm/ttm_range_manager.c
> @@ -138,7 +138,7 @@ static const struct ttm_resource_manager_func ttm_range_manager_func = {
>    * Initialise a generic range manager for the selected memory type.
>    * The range manager is installed for this device in the type slot.
>    */
> -int ttm_range_man_init(struct ttm_device *bdev,
> +int ttm_range_man_init_nocheck(struct ttm_device *bdev,
>   		       unsigned type, bool use_tt,
>   		       unsigned long p_size)
>   {
> @@ -163,7 +163,7 @@ int ttm_range_man_init(struct ttm_device *bdev,
>   	ttm_resource_manager_set_used(man, true);
>   	return 0;
>   }
> -EXPORT_SYMBOL(ttm_range_man_init);
> +EXPORT_SYMBOL(ttm_range_man_init_nocheck);
>   
>   /**
>    * ttm_range_man_fini
> @@ -173,7 +173,7 @@ EXPORT_SYMBOL(ttm_range_man_init);
>    *
>    * Remove the generic range manager from a slot and tear it down.
>    */
> -int ttm_range_man_fini(struct ttm_device *bdev,
> +int ttm_range_man_fini_nocheck(struct ttm_device *bdev,
>   		       unsigned type)
>   {
>   	struct ttm_resource_manager *man = ttm_manager_type(bdev, type);
> @@ -197,4 +197,4 @@ int ttm_range_man_fini(struct ttm_device *bdev,
>   	kfree(rman);
>   	return 0;
>   }
> -EXPORT_SYMBOL(ttm_range_man_fini);
> +EXPORT_SYMBOL(ttm_range_man_fini_nocheck);
> diff --git a/include/drm/ttm/ttm_device.h b/include/drm/ttm/ttm_device.h
> index 07d722950d5b..6f23724f5a06 100644
> --- a/include/drm/ttm/ttm_device.h
> +++ b/include/drm/ttm/ttm_device.h
> @@ -285,12 +285,15 @@ int ttm_device_swapout(struct ttm_device *bdev, struct ttm_operation_ctx *ctx,
>   static inline struct ttm_resource_manager *
>   ttm_manager_type(struct ttm_device *bdev, int mem_type)
>   {
> +	BUILD_BUG_ON(__builtin_constant_p(mem_type)
> +		     && mem_type >= TTM_NUM_MEM_TYPES);
>   	return bdev->man_drv[mem_type];
>   }
>   
>   static inline void ttm_set_driver_manager(struct ttm_device *bdev, int type,
>   					  struct ttm_resource_manager *manager)
>   {
> +	BUILD_BUG_ON(__builtin_constant_p(type) && type >= TTM_NUM_MEM_TYPES);
>   	bdev->man_drv[type] = manager;
>   }
>   
> diff --git a/include/drm/ttm/ttm_range_manager.h b/include/drm/ttm/ttm_range_manager.h
> index 22b6fa42ac20..7963b957e9ef 100644
> --- a/include/drm/ttm/ttm_range_manager.h
> +++ b/include/drm/ttm/ttm_range_manager.h
> @@ -4,6 +4,7 @@
>   #define _TTM_RANGE_MANAGER_H_
>   
>   #include <drm/ttm/ttm_resource.h>
> +#include <drm/ttm/ttm_device.h>
>   #include <drm/drm_mm.h>
>   
>   /**
> @@ -33,10 +34,23 @@ to_ttm_range_mgr_node(struct ttm_resource *res)
>   	return container_of(res, struct ttm_range_mgr_node, base);
>   }
>   
> -int ttm_range_man_init(struct ttm_device *bdev,
> +int ttm_range_man_init_nocheck(struct ttm_device *bdev,
>   		       unsigned type, bool use_tt,
>   		       unsigned long p_size);
> -int ttm_range_man_fini(struct ttm_device *bdev,
> +int ttm_range_man_fini_nocheck(struct ttm_device *bdev,
>   		       unsigned type);
> +static __always_inline int ttm_range_man_init(struct ttm_device *bdev,
> +		       unsigned int type, bool use_tt,
> +		       unsigned long p_size)
> +{
> +	BUILD_BUG_ON(__builtin_constant_p(type) && type >= TTM_NUM_MEM_TYPES);
> +	return ttm_range_man_init_nocheck(bdev, type, use_tt, p_size);
> +}
>   
> +static __always_inline int ttm_range_man_fini(struct ttm_device *bdev,
> +		       unsigned int type)
> +{
> +	BUILD_BUG_ON(__builtin_constant_p(type) && type >= TTM_NUM_MEM_TYPES);
> +	return ttm_range_man_fini_nocheck(bdev, type);
> +}
>   #endif