[Intel-gfx] [PATCH 3/5] drm/i915: Extract CSB status read

[Daniel Vetter]

On Tue, Jan 05, 2016 at 10:30:07AM -0800, Ben Widawsky wrote:
> This is a useful thing to have around as a function because the mechanism may
> change in the future.
> 
> There is a net increase in LOC here, and it will continue to be the case on GEN8
> and GEN9 - but future GENs may have an alternate mechanism for doing this.
> 
> Signed-off-by: Ben Widawsky <benjamin.widawsky at intel.com>

Merged up to this one to dinq.

Thanks, Daniel

> ---
>  drivers/gpu/drm/i915/intel_lrc.c | 19 ++++++++++++++++---
>  1 file changed, 16 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
> index 14affaa..23839ff 100644
> --- a/drivers/gpu/drm/i915/intel_lrc.c
> +++ b/drivers/gpu/drm/i915/intel_lrc.c
> @@ -496,6 +496,19 @@ static bool execlists_check_remove_request(struct intel_engine_cs *ring,
>  	return false;
>  }
>  
> +static void get_context_status(struct intel_engine_cs *ring,
> +			       u8 read_pointer,
> +			       u32 *status, u32 *context_id)
> +{
> +	struct drm_i915_private *dev_priv = ring->dev->dev_private;
> +
> +	if (WARN_ON(read_pointer >= GEN8_CSB_ENTRIES))
> +		return;
> +
> +	*status = I915_READ(RING_CONTEXT_STATUS_BUF_LO(ring, read_pointer));
> +	*context_id = I915_READ(RING_CONTEXT_STATUS_BUF_HI(ring, read_pointer));
> +}
> +
>  /**
>   * intel_lrc_irq_handler() - handle Context Switch interrupts
>   * @ring: Engine Command Streamer to handle.
> @@ -523,9 +536,9 @@ void intel_lrc_irq_handler(struct intel_engine_cs *ring)
>  	spin_lock(&ring->execlist_lock);
>  
>  	while (read_pointer < write_pointer) {
> -		read_pointer++;
> -		status = I915_READ(RING_CONTEXT_STATUS_BUF_LO(ring, read_pointer % GEN8_CSB_ENTRIES));
> -		status_id = I915_READ(RING_CONTEXT_STATUS_BUF_HI(ring, read_pointer % GEN8_CSB_ENTRIES));
> +
> +		get_context_status(ring, ++read_pointer % GEN8_CSB_ENTRIES,
> +				   &status, &status_id);
>  
>  		if (status & GEN8_CTX_STATUS_IDLE_ACTIVE)
>  			continue;
> -- 
> 2.6.4
> 
> _______________________________________________
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> Intel-gfx at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch