Re: [PATCH][next] drm/amdgpu/amdkfd: Avoid a couple hundred -Wflex-array-member-not-at-end warnings

["Kuehling, Felix" <felix.kuehling@amd.com>]

On 2025-08-29 5:58 a.m., Gustavo A. R. Silva wrote:
> -Wflex-array-member-not-at-end was introduced in GCC-14, and we are
> getting ready to enable it, globally.
>
> Move the conflicting declarations to the end of the corresponding
> structures. Notice that `struct dev_pagemap` is a flexible structure,
> this is a structure that contains a flexible-array member.
>
> Fix 283 of the following type of warnings:
>      283 drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h:111:28: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
>
> Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Thank you. I'll apply this to amd-staging-drm-next. I'll also add a note 
to the commit description that struct dev_pagemap always has space for 
at least one range, and that amdgpu only uses a single range. Therefore 
no changes are needed in the way struct amdgpu_device is allocated.

Reviewed-by: Felix Kuehling <felix.kuehling@amd.com>


> ---
>   drivers/gpu/drm/amd/amdgpu/amdgpu.h        | 8 +++++---
>   drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h | 8 +++++---
>   2 files changed, 10 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> index ddd472e56f69..24f3e5cfbe5d 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
> @@ -1155,9 +1155,6 @@ struct amdgpu_device {
>   	/* for userq and VM fences */
>   	struct amdgpu_seq64		seq64;
>   
> -	/* KFD */
> -	struct amdgpu_kfd_dev		kfd;
> -
>   	/* UMC */
>   	struct amdgpu_umc		umc;
>   
> @@ -1320,6 +1317,11 @@ struct amdgpu_device {
>   	struct mutex                    userq_mutex;
>   	bool                            userq_halt_for_enforce_isolation;
>   	struct amdgpu_uid *uid_info;
> +
> +	/* KFD
> +	 * Must be last --ends in a flexible-array member.
> +	 */
> +	struct amdgpu_kfd_dev		kfd;
>   };
>   
>   static inline uint32_t amdgpu_ip_version(const struct amdgpu_device *adev,
> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> index 33eb4826b58b..127927b16ee2 100644
> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.h
> @@ -107,11 +107,13 @@ struct amdgpu_kfd_dev {
>   	bool init_complete;
>   	struct work_struct reset_work;
>   
> -	/* HMM page migration MEMORY_DEVICE_PRIVATE mapping */
> -	struct dev_pagemap pgmap;
> -
>   	/* Client for KFD BO GEM handle allocations */
>   	struct drm_client_dev client;
> +
> +	/* HMM page migration MEMORY_DEVICE_PRIVATE mapping
> +	 * Must be last --ends in a flexible-array member.
> +	 */
> +	struct dev_pagemap pgmap;
>   };
>   
>   enum kgd_engine_type {