From: Boris Brezillon Date: Fri, 6 Jun 2025 08:09:31 +0000 (+0200) Subject: drm/panthor: Add missing explicit padding in drm_panthor_gpu_info X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=95cbab48782bf62e4093837dc15ac6133902c12f;p=thirdparty%2Flinux.git drm/panthor: Add missing explicit padding in drm_panthor_gpu_info drm_panthor_gpu_info::shader_present is currently automatically offset by 4 byte to meet Arm's 32-bit/64-bit field alignment rules, but those constraints don't stand on 32-bit x86 and cause a mismatch when running an x86 binary in a user emulated environment like FEX. It's also generally agreed that uAPIs should explicitly pad their struct fields, which we originally intended to do, but a mistake slipped through during the submission process, leading drm_panthor_gpu_info::shader_present to be misaligned. This uAPI change doesn't break any of the existing users of panthor which are either arm32 or arm64 where the 64-bit alignment of u64 fields is already enforced a the compiler level. Changes in v2: - Rename the garbage field into pad0 and adjust the comment accordingly - Add Liviu's A-b Changes in v3: - Add R-bs Fixes: 0f25e493a246 ("drm/panthor: Add uAPI") Acked-by: Liviu Dudau Reviewed-by: Adrián Larumbe Reviewed-by: Steven Price Link: https://lore.kernel.org/r/20250606080932.4140010-2-boris.brezillon@collabora.com Signed-off-by: Boris Brezillon --- diff --git a/include/uapi/drm/panthor_drm.h b/include/uapi/drm/panthor_drm.h index ad9a70afea6c2..3a76c4f2882b6 100644 --- a/include/uapi/drm/panthor_drm.h +++ b/include/uapi/drm/panthor_drm.h @@ -296,6 +296,9 @@ struct drm_panthor_gpu_info { /** @as_present: Bitmask encoding the number of address-space exposed by the MMU. */ __u32 as_present; + /** @pad0: MBZ. */ + __u32 pad0; + /** @shader_present: Bitmask encoding the shader cores exposed by the GPU. */ __u64 shader_present;