Re: [PATCH v2 7/7] drm/xe/uapi: Add a query flag for has_device_atomics_on_smem

["Souza, Jose" <jose.souza@intel.com>]

On Fri, 2024-04-12 at 11:22 +0200, Nirmoy Das wrote:
> Add a query flag for xe->info.has_device_atomics_on_smem
> as this is platform dependent. This flag can be use to inform
> whether DRM_XE_VM_BIND_FLAG_DEVICE_ATOMICS can be effectively
> applied for a given platform.
> 
> Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_query.c | 4 +++-
>  include/uapi/drm/xe_drm.h     | 3 +++
>  2 files changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_query.c b/drivers/gpu/drm/xe/xe_query.c
> index df407d73e5f5..b8a606698e38 100644
> --- a/drivers/gpu/drm/xe/xe_query.c
> +++ b/drivers/gpu/drm/xe/xe_query.c
> @@ -312,7 +312,7 @@ static int query_mem_regions(struct xe_device *xe,
>  
>  static int query_config(struct xe_device *xe, struct drm_xe_device_query *query)
>  {
> -	const u32 num_params = DRM_XE_QUERY_CONFIG_MAX_EXEC_QUEUE_PRIORITY + 1;
> +	const u32 num_params = DRM_XE_QUERY_CONFIG_SUPP_DEV_ATOMIC_ON_SMEM + 1;
>  	size_t size =
>  		sizeof(struct drm_xe_query_config) + num_params * sizeof(u64);
>  	struct drm_xe_query_config __user *query_ptr =
> @@ -341,6 +341,8 @@ static int query_config(struct xe_device *xe, struct drm_xe_device_query *query)
>  	config->info[DRM_XE_QUERY_CONFIG_VA_BITS] = xe->info.va_bits;
>  	config->info[DRM_XE_QUERY_CONFIG_MAX_EXEC_QUEUE_PRIORITY] =
>  		xe_exec_queue_device_get_max_priority(xe);
> +	config->info[DRM_XE_QUERY_CONFIG_SUPP_DEV_ATOMIC_ON_SMEM] =
> +		xe->info.has_device_atomics_on_smem;
>  
>  	if (copy_to_user(query_ptr, config, size)) {
>  		kfree(config);
> diff --git a/include/uapi/drm/xe_drm.h b/include/uapi/drm/xe_drm.h
> index a44c057d4471..4804b8a5d028 100644
> --- a/include/uapi/drm/xe_drm.h
> +++ b/include/uapi/drm/xe_drm.h
> @@ -394,6 +394,8 @@ struct drm_xe_query_mem_regions {
>   *  - %DRM_XE_QUERY_CONFIG_VA_BITS - Maximum bits of a virtual address
>   *  - %DRM_XE_QUERY_CONFIG_MAX_EXEC_QUEUE_PRIORITY - Value of the highest
>   *    available exec queue priority
> + *  - %DRM_XE_QUERY_CONFIG_SUPP_DEV_ATOMIC_ON_SMEM - Flag is set if the device
> + *    supports device atomics on system memory
>   */
>  struct drm_xe_query_config {
>  	/** @num_params: number of parameters returned in info */
> @@ -408,6 +410,7 @@ struct drm_xe_query_config {
>  #define DRM_XE_QUERY_CONFIG_MIN_ALIGNMENT		2
>  #define DRM_XE_QUERY_CONFIG_VA_BITS			3
>  #define DRM_XE_QUERY_CONFIG_MAX_EXEC_QUEUE_PRIORITY	4
> +#define DRM_XE_QUERY_CONFIG_SUPP_DEV_ATOMIC_ON_SMEM	5
>  	/** @info: array of elements containing the config info */
>  	__u64 info[];

this will use a whole 64bits for just one bit, better add as add as a bit in DRM_XE_QUERY_CONFIG_FLAGS(after DRM_XE_QUERY_CONFIG_FLAG_HAS_VRAM)

>  };