Re: [PATCH v9 06/26] drm/xe/device: Update handling of xe_force_wake_get return

["Nilawar, Badal" <badal.nilawar@intel.com>]

On 14-10-2024 13:25, Himal Prasad Ghimiray wrote:
> xe_force_wake_get() now returns the reference count-incremented domain
> mask. If it fails for individual domains, the return value will always
> be 0. However, for XE_FORCEWAKE_ALL, it may return a non-zero value even
> in the event of failure. Update the return handling of xe_force_wake_get()
> to reflect this behavior, and ensure that the return value is passed as
> input to xe_force_wake_put().
> 
> v3
> - return xe_wakeref_t instead of int in xe_force_wake_get()
> - xe_force_wake_put() error doesn't need to be escalated/considered as
> probing error. It internally WARNS on domain ack failure.
> 
> v5
> - return unsigned int xe_force_wake_get()
> 
> v7
> - Fix commit message(Badal)
> 
> v9
> - s/uint/unsigned int (Nikula)
> 
> Cc: Jani Nikula <jani.nikula@intel.com>
> Cc: Badal Nilawar <badal.nilawar@intel.com>
> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
> Signed-off-by: Himal Prasad Ghimiray <himal.prasad.ghimiray@intel.com>
> ---
>   drivers/gpu/drm/xe/xe_device.c | 25 ++++++++++++++-----------
>   1 file changed, 14 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/xe_device.c b/drivers/gpu/drm/xe/xe_device.c
> index 962751c966d1..16b10bbccc6b 100644
> --- a/drivers/gpu/drm/xe/xe_device.c
> +++ b/drivers/gpu/drm/xe/xe_device.c
> @@ -604,8 +604,8 @@ int xe_device_probe_early(struct xe_device *xe)
>   static int probe_has_flat_ccs(struct xe_device *xe)
>   {
>   	struct xe_gt *gt;
> +	unsigned int fw_ref;
>   	u32 reg;
> -	int err;
>   
>   	/* Always enabled/disabled, no runtime check to do */
>   	if (GRAPHICS_VER(xe) < 20 || !xe->info.has_flat_ccs)
> @@ -613,9 +613,9 @@ static int probe_has_flat_ccs(struct xe_device *xe)
>   
>   	gt = xe_root_mmio_gt(xe);
>   
> -	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
> -	if (err)
> -		return err;
> +	fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
> +	if (!fw_ref)
> +		return -ETIMEDOUT;
>   
>   	reg = xe_gt_mcr_unicast_read_any(gt, XE2_FLAT_CCS_BASE_RANGE_LOWER);
>   	xe->info.has_flat_ccs = (reg & XE2_FLAT_CCS_ENABLE);
> @@ -624,7 +624,8 @@ static int probe_has_flat_ccs(struct xe_device *xe)
>   		drm_dbg(&xe->drm,
>   			"Flat CCS has been disabled in bios, May lead to performance impact");
>   
> -	return xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
> +	xe_force_wake_put(gt_to_fw(gt), fw_ref);
> +	return 0;
>   }
>   
>   int xe_device_probe(struct xe_device *xe)
> @@ -875,6 +876,7 @@ void xe_device_wmb(struct xe_device *xe)
>   void xe_device_td_flush(struct xe_device *xe)
>   {
>   	struct xe_gt *gt;
> +	unsigned int fw_ref;
>   	u8 id;
>   
>   	if (!IS_DGFX(xe) || GRAPHICS_VER(xe) < 20)
> @@ -889,7 +891,8 @@ void xe_device_td_flush(struct xe_device *xe)
>   		if (xe_gt_is_media_type(gt))
>   			continue;
>   
> -		if (xe_force_wake_get(gt_to_fw(gt), XE_FW_GT))
> +		fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
> +		if (!fw_ref)
>   			return;
>   
>   		xe_mmio_write32(&gt->mmio, XE2_TDF_CTRL, TRANSIENT_FLUSH_REQUEST);
> @@ -904,22 +907,22 @@ void xe_device_td_flush(struct xe_device *xe)
>   				   150, NULL, false))
>   			xe_gt_err_once(gt, "TD flush timeout\n");
>   
> -		xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
> +		xe_force_wake_put(gt_to_fw(gt), fw_ref);
>   	}
>   }
>   
>   void xe_device_l2_flush(struct xe_device *xe)
>   {
>   	struct xe_gt *gt;
> -	int err;
> +	unsigned int fw_ref;
>   
>   	gt = xe_root_mmio_gt(xe);
>   
>   	if (!XE_WA(gt, 16023588340))
>   		return;
>   
> -	err = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
> -	if (err)
> +	fw_ref = xe_force_wake_get(gt_to_fw(gt), XE_FW_GT);
> +	if (!fw_ref)
>   		return;
>   
>   	spin_lock(&gt->global_invl_lock);
> @@ -929,7 +932,7 @@ void xe_device_l2_flush(struct xe_device *xe)
>   		xe_gt_err_once(gt, "Global invalidation timeout\n");
>   	spin_unlock(&gt->global_invl_lock);
>   
> -	xe_force_wake_put(gt_to_fw(gt), XE_FW_GT);
> +	xe_force_wake_put(gt_to_fw(gt), fw_ref);
>   }

LGTM.
Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>

>   
>   u32 xe_device_ccs_bytes(struct xe_device *xe, u64 size)