Re: [PATCH v2 5/7] drm/xe: Introduce has_device_atomics_on_smem device info

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

On Fri, 2024-04-12 at 11:22 +0200, Nirmoy Das wrote:
> Add has_device_atomics_on_smem to specify that a device
> supports device atomics on system memory. Currently XE2
> supports this so set this for XE2.
> 
> Signed-off-by: Nirmoy Das <nirmoy.das@intel.com>
> ---
>  drivers/gpu/drm/xe/xe_device_types.h | 2 ++
>  drivers/gpu/drm/xe/xe_pci.c          | 2 ++
>  drivers/gpu/drm/xe/xe_pci_types.h    | 1 +
>  3 files changed, 5 insertions(+)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device_types.h b/drivers/gpu/drm/xe/xe_device_types.h
> index bde42fe288ff..c06be1e00f1a 100644
> --- a/drivers/gpu/drm/xe/xe_device_types.h
> +++ b/drivers/gpu/drm/xe/xe_device_types.h
> @@ -283,6 +283,8 @@ struct xe_device {
>  		u8 skip_guc_pc:1;
>  		/** @info.has_atomic_enable_pte_bit: Device has atomic enable PTE bit */
>  		u8 has_atomic_enable_pte_bit:1;
> +		/** @info.has_device_atomics_on_smem: Supports device atomics on SMEM */
> +		u8 has_device_atomics_on_smem:1;
>  

This one can be easily replaced by a simple gfx_ip >= 20.

In my opinion it should only be added to xe_graphics_desc when feature check is more complex, like the has_atomic_enable_pte_bit.
Otherwise it will get complex and error prone to add new platforms.

>  #if IS_ENABLED(CONFIG_DRM_XE_DISPLAY)
>  		struct {
> diff --git a/drivers/gpu/drm/xe/xe_pci.c b/drivers/gpu/drm/xe/xe_pci.c
> index 9cf45559b915..4e4699962337 100644
> --- a/drivers/gpu/drm/xe/xe_pci.c
> +++ b/drivers/gpu/drm/xe/xe_pci.c
> @@ -165,6 +165,7 @@ static const struct xe_graphics_desc graphics_xelpg = {
>  	.dma_mask_size = 46, \
>  	.has_asid = 1, \
>  	.has_atomic_enable_pte_bit = 1, \
> +	.has_device_atomics_on_smem = 1, \
>  	.has_flat_ccs = 1, \
>  	.has_range_tlb_invalidation = 1, \
>  	.has_usm = 1, \
> @@ -630,6 +631,7 @@ static int xe_info_init(struct xe_device *xe,
>  	xe->info.vm_max_level = graphics_desc->vm_max_level;
>  	xe->info.has_asid = graphics_desc->has_asid;
>  	xe->info.has_atomic_enable_pte_bit = graphics_desc->has_atomic_enable_pte_bit;
> +	xe->info.has_device_atomics_on_smem = graphics_desc->has_device_atomics_on_smem;
>  	xe->info.has_flat_ccs = graphics_desc->has_flat_ccs;
>  	xe->info.has_range_tlb_invalidation = graphics_desc->has_range_tlb_invalidation;
>  	xe->info.has_usm = graphics_desc->has_usm;
> diff --git a/drivers/gpu/drm/xe/xe_pci_types.h b/drivers/gpu/drm/xe/xe_pci_types.h
> index e1f2b4879fc2..d403814a7a84 100644
> --- a/drivers/gpu/drm/xe/xe_pci_types.h
> +++ b/drivers/gpu/drm/xe/xe_pci_types.h
> @@ -26,6 +26,7 @@ struct xe_graphics_desc {
>  
>  	u8 has_asid:1;
>  	u8 has_atomic_enable_pte_bit:1;
> +	u8 has_device_atomics_on_smem:1;
>  	u8 has_flat_ccs:1;
>  	u8 has_range_tlb_invalidation:1;
>  	u8 has_usm:1;