[Intel-gfx] [PATCH] drm/i915: Store number of active engines in device info

[Dave Gordon]

On 10/08/16 16:22, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>
> Until now code was calling hweight32 to figure out the
> number from device_info->ring_mask at runtime. Instead
> we can cache it at engine init time and use directly.
>
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c     |  2 +-
>  drivers/gpu/drm/i915/i915_drv.h         |  1 +
>  drivers/gpu/drm/i915/i915_gem_context.c |  2 +-
>  drivers/gpu/drm/i915/intel_engine_cs.c  | 10 +++++-----
>  drivers/gpu/drm/i915/intel_ringbuffer.c |  6 +++---
>  5 files changed, 11 insertions(+), 10 deletions(-)

LGTM.

Reviewed-by: Dave Gordon <david.s.gordon at intel.com>

> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index 83f40e869955..c461072da142 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -3226,7 +3226,7 @@ static int i915_semaphore_status(struct seq_file *m, void *unused)
>  	struct drm_device *dev = node->minor->dev;
>  	struct drm_i915_private *dev_priv = to_i915(dev);
>  	struct intel_engine_cs *engine;
> -	int num_rings = hweight32(INTEL_INFO(dev)->ring_mask);
> +	int num_rings = INTEL_INFO(dev)->num_rings;
>  	enum intel_engine_id id;
>  	int j, ret;
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 7f2754a070a5..7971c76852df 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -793,6 +793,7 @@ struct intel_device_info {
>  	u8 gen;
>  	u16 gen_mask;
>  	u8 ring_mask; /* Rings supported by the HW */
> +	u8 num_rings;
>  	DEV_INFO_FOR_EACH_FLAG(DEFINE_FLAG, SEP_SEMICOLON);
>  	/* Register offsets for the various display pipes and transcoders */
>  	int pipe_offsets[I915_MAX_TRANSCODERS];
> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c b/drivers/gpu/drm/i915/i915_gem_context.c
> index bb72af5320b0..547caf26a6b9 100644
> --- a/drivers/gpu/drm/i915/i915_gem_context.c
> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
> @@ -568,7 +568,7 @@ mi_set_context(struct drm_i915_gem_request *req, u32 hw_flags)
>  	const int num_rings =
>  		/* Use an extended w/a on ivb+ if signalling from other rings */
>  		i915.semaphores ?
> -		hweight32(INTEL_INFO(dev_priv)->ring_mask) - 1 :
> +		INTEL_INFO(dev_priv)->num_rings - 1 :
>  		0;
>  	int len, ret;
>
> diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
> index 0dd3d1de18aa..186c12d07f99 100644
> --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> @@ -109,6 +109,7 @@ intel_engine_setup(struct drm_i915_private *dev_priv,
>  int intel_engines_init(struct drm_device *dev)
>  {
>  	struct drm_i915_private *dev_priv = to_i915(dev);
> +	struct intel_device_info *device_info = mkwrite_device_info(dev_priv);
>  	unsigned int mask = 0;
>  	int (*init)(struct intel_engine_cs *engine);
>  	unsigned int i;
> @@ -142,11 +143,10 @@ int intel_engines_init(struct drm_device *dev)
>  	 * are added to the driver by a warning and disabling the forgotten
>  	 * engines.
>  	 */
> -	if (WARN_ON(mask != INTEL_INFO(dev_priv)->ring_mask)) {
> -		struct intel_device_info *info =
> -			(struct intel_device_info *)&dev_priv->info;
> -		info->ring_mask = mask;
> -	}
> +	if (WARN_ON(mask != INTEL_INFO(dev_priv)->ring_mask))
> +		device_info->ring_mask = mask;
> +
> +	device_info->num_rings = hweight32(mask);
>
>  	return 0;
>
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 16b726fe33eb..a05a2a13ea7c 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -1317,7 +1317,7 @@ static int gen8_rcs_signal(struct drm_i915_gem_request *req)
>  	enum intel_engine_id id;
>  	int ret, num_rings;
>
> -	num_rings = hweight32(INTEL_INFO(dev_priv)->ring_mask);
> +	num_rings = INTEL_INFO(dev_priv)->num_rings;
>  	ret = intel_ring_begin(req, (num_rings-1) * 8);
>  	if (ret)
>  		return ret;
> @@ -1354,7 +1354,7 @@ static int gen8_xcs_signal(struct drm_i915_gem_request *req)
>  	enum intel_engine_id id;
>  	int ret, num_rings;
>
> -	num_rings = hweight32(INTEL_INFO(dev_priv)->ring_mask);
> +	num_rings = INTEL_INFO(dev_priv)->num_rings;
>  	ret = intel_ring_begin(req, (num_rings-1) * 6);
>  	if (ret)
>  		return ret;
> @@ -1389,7 +1389,7 @@ static int gen6_signal(struct drm_i915_gem_request *req)
>  	enum intel_engine_id id;
>  	int ret, num_rings;
>
> -	num_rings = hweight32(INTEL_INFO(dev_priv)->ring_mask);
> +	num_rings = INTEL_INFO(dev_priv)->num_rings;
>  	ret = intel_ring_begin(req, round_up((num_rings-1) * 3, 2));
>  	if (ret)
>  		return ret;
>