[Intel-gfx] [PATCH 17/24] drm/i915: kill dev_priv->rps.lock

Ben Widawsky ben at bwidawsk.net
Fri Jun 28 05:35:17 CEST 2013


On Wed, Jun 12, 2013 at 01:37:19PM +0200, Daniel Vetter wrote:
> Now that the rps interrupt locking isn't clearly separated (at elast
> conceptually) from all the other interrupt locking having a different
> lock stopped making sense. With this we can (again) unifiy the
> ringbuffer irq refcounts without causing a massive confusion, but
> that's for the next patch.

I think the original reason for the RPS lock still makes sense, so I'd
say your assertion should be that it's not worth the extra complexity,
which I can agree with. (The original use of the rps_lock was just for
the rps workqueue, it expanded a bunch since then).

> 
> Signed-off-by: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
>  drivers/gpu/drm/i915/i915_dma.c         |  1 -
>  drivers/gpu/drm/i915/i915_drv.h         |  8 ++++----
>  drivers/gpu/drm/i915/i915_irq.c         | 12 ++++++------
>  drivers/gpu/drm/i915/intel_pm.c         | 16 ++++++++--------
>  drivers/gpu/drm/i915/intel_ringbuffer.c |  8 ++++----
>  drivers/gpu/drm/i915/intel_ringbuffer.h |  2 +-
>  6 files changed, 23 insertions(+), 24 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_dma.c b/drivers/gpu/drm/i915/i915_dma.c
> index b913b3d..14c3e9c 100644
> --- a/drivers/gpu/drm/i915/i915_dma.c
> +++ b/drivers/gpu/drm/i915/i915_dma.c
> @@ -1612,7 +1612,6 @@ int i915_driver_load(struct drm_device *dev, unsigned long flags)
>  
>  	spin_lock_init(&dev_priv->irq_lock);
>  	spin_lock_init(&dev_priv->gpu_error.lock);
> -	spin_lock_init(&dev_priv->rps.lock);
>  	spin_lock_init(&dev_priv->backlight.lock);
>  	mutex_init(&dev_priv->dpio_lock);
>  
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 07954b2..42d1363 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -691,12 +691,12 @@ struct i915_suspend_saved_registers {
>  };
>  
>  struct intel_gen6_power_mgmt {
> +	/* work and pm_iir are protected by dev_priv->irq_lock */
>  	struct work_struct work;
> -	struct delayed_work vlv_work;
>  	u32 pm_iir;
> -	/* lock - irqsave spinlock that protectects the work_struct and
> -	 * pm_iir. */
> -	spinlock_t lock;
> +
> +	/* On vlv we need to manually drop to Vmin with a delayed work. */
> +	struct delayed_work vlv_work;
A bit unrelated, but meh.
>  
>  	/* The below variables an all the rps hw state are protected by
>  	 * dev->struct mutext. */
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 752b98d..cd7135d 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -696,13 +696,13 @@ static void gen6_pm_rps_work(struct work_struct *work)
>  	u32 pm_iir, pm_imr;
>  	u8 new_delay;
>  
> -	spin_lock_irq(&dev_priv->rps.lock);
> +	spin_lock_irq(&dev_priv->irq_lock);
>  	pm_iir = dev_priv->rps.pm_iir;
>  	dev_priv->rps.pm_iir = 0;
>  	pm_imr = I915_READ(GEN6_PMIMR);
>  	/* Make sure not to corrupt PMIMR state used by ringbuffer code */
>  	I915_WRITE(GEN6_PMIMR, pm_imr & ~GEN6_PM_RPS_EVENTS);
> -	spin_unlock_irq(&dev_priv->rps.lock);
> +	spin_unlock_irq(&dev_priv->irq_lock);
>  
>  	if ((pm_iir & GEN6_PM_RPS_EVENTS) == 0)
>  		return;
> @@ -856,11 +856,11 @@ static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv,
>  	 * The mask bit in IMR is cleared by dev_priv->rps.work.
>  	 */
>  
> -	spin_lock(&dev_priv->rps.lock);
> +	spin_lock(&dev_priv->irq_lock);
>  	dev_priv->rps.pm_iir |= pm_iir;
>  	I915_WRITE(GEN6_PMIMR, dev_priv->rps.pm_iir);
>  	POSTING_READ(GEN6_PMIMR);
> -	spin_unlock(&dev_priv->rps.lock);
> +	spin_unlock(&dev_priv->irq_lock);
>  
>  	queue_work(dev_priv->wq, &dev_priv->rps.work);
>  }
> @@ -933,12 +933,12 @@ static void hsw_pm_irq_handler(struct drm_i915_private *dev_priv,
>  			       u32 pm_iir)
>  {
>  	if (pm_iir & GEN6_PM_RPS_EVENTS) {
> -		spin_lock(&dev_priv->rps.lock);
> +		spin_lock(&dev_priv->irq_lock);
>  		dev_priv->rps.pm_iir |= pm_iir & GEN6_PM_RPS_EVENTS;
>  		I915_WRITE(GEN6_PMIMR, dev_priv->rps.pm_iir);
>  		/* never want to mask useful interrupts. (also posting read) */
>  		WARN_ON(I915_READ_NOTRACE(GEN6_PMIMR) & ~GEN6_PM_RPS_EVENTS);
> -		spin_unlock(&dev_priv->rps.lock);
> +		spin_unlock(&dev_priv->irq_lock);
>  
>  		queue_work(dev_priv->wq, &dev_priv->rps.work);
>  	}
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index adc44e4..6a5cfb5 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3128,9 +3128,9 @@ static void gen6_disable_rps(struct drm_device *dev)
>  	 * register (PMIMR) to mask PM interrupts. The only risk is in leaving
>  	 * stale bits in PMIIR and PMIMR which gen6_enable_rps will clean up. */
>  
> -	spin_lock_irq(&dev_priv->rps.lock);
> +	spin_lock_irq(&dev_priv->irq_lock);
>  	dev_priv->rps.pm_iir = 0;
> -	spin_unlock_irq(&dev_priv->rps.lock);
> +	spin_unlock_irq(&dev_priv->irq_lock);
>  
>  	I915_WRITE(GEN6_PMIIR, GEN6_PM_RPS_EVENTS);
>  }
> @@ -3147,9 +3147,9 @@ static void valleyview_disable_rps(struct drm_device *dev)
>  	 * register (PMIMR) to mask PM interrupts. The only risk is in leaving
>  	 * stale bits in PMIIR and PMIMR which gen6_enable_rps will clean up. */
>  
> -	spin_lock_irq(&dev_priv->rps.lock);
> +	spin_lock_irq(&dev_priv->irq_lock);
>  	dev_priv->rps.pm_iir = 0;
> -	spin_unlock_irq(&dev_priv->rps.lock);
> +	spin_unlock_irq(&dev_priv->irq_lock);
>  
>  	I915_WRITE(GEN6_PMIIR, I915_READ(GEN6_PMIIR));
>  
> @@ -3314,13 +3314,13 @@ static void gen6_enable_rps(struct drm_device *dev)
>  
>  	/* requires MSI enabled */
>  	I915_WRITE(GEN6_PMIER, I915_READ(GEN6_PMIER) | GEN6_PM_RPS_EVENTS);
> -	spin_lock_irq(&dev_priv->rps.lock);
> +	spin_lock_irq(&dev_priv->irq_lock);
>  	/* FIXME: Our interrupt enabling sequence is bonghits.
>  	 * dev_priv->rps.pm_iir really should be 0 here. */
>  	dev_priv->rps.pm_iir = 0;
>  	I915_WRITE(GEN6_PMIMR, I915_READ(GEN6_PMIMR) & ~GEN6_PM_RPS_EVENTS);
>  	I915_WRITE(GEN6_PMIIR, GEN6_PM_RPS_EVENTS);
> -	spin_unlock_irq(&dev_priv->rps.lock);
> +	spin_unlock_irq(&dev_priv->irq_lock);
>  	/* unmask all PM interrupts */
>  	I915_WRITE(GEN6_PMINTRMSK, 0);
>  
> @@ -3585,10 +3585,10 @@ static void valleyview_enable_rps(struct drm_device *dev)
>  
>  	/* requires MSI enabled */
>  	I915_WRITE(GEN6_PMIER, GEN6_PM_RPS_EVENTS);
> -	spin_lock_irq(&dev_priv->rps.lock);
> +	spin_lock_irq(&dev_priv->irq_lock);
>  	WARN_ON(dev_priv->rps.pm_iir != 0);
>  	I915_WRITE(GEN6_PMIMR, 0);
> -	spin_unlock_irq(&dev_priv->rps.lock);
> +	spin_unlock_irq(&dev_priv->irq_lock);
>  	/* enable all PM interrupts */
>  	I915_WRITE(GEN6_PMINTRMSK, 0);
>  
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> index 1ef081c..a7c9934 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> @@ -1053,14 +1053,14 @@ hsw_vebox_get_irq(struct intel_ring_buffer *ring)
>  	if (!dev->irq_enabled)
>  		return false;
>  
> -	spin_lock_irqsave(&dev_priv->rps.lock, flags);
> +	spin_lock_irqsave(&dev_priv->irq_lock, flags);
>  	if (ring->irq_refcount.pm++ == 0) {
>  		u32 pm_imr = I915_READ(GEN6_PMIMR);
>  		I915_WRITE_IMR(ring, ~ring->irq_enable_mask);
>  		I915_WRITE(GEN6_PMIMR, pm_imr & ~ring->irq_enable_mask);
>  		POSTING_READ(GEN6_PMIMR);
>  	}
> -	spin_unlock_irqrestore(&dev_priv->rps.lock, flags);
> +	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
>  
>  	return true;
>  }
> @@ -1075,14 +1075,14 @@ hsw_vebox_put_irq(struct intel_ring_buffer *ring)
>  	if (!dev->irq_enabled)
>  		return;
>  
> -	spin_lock_irqsave(&dev_priv->rps.lock, flags);
> +	spin_lock_irqsave(&dev_priv->irq_lock, flags);
>  	if (--ring->irq_refcount.pm == 0) {
>  		u32 pm_imr = I915_READ(GEN6_PMIMR);
>  		I915_WRITE_IMR(ring, ~0);
>  		I915_WRITE(GEN6_PMIMR, pm_imr | ring->irq_enable_mask);
>  		POSTING_READ(GEN6_PMIMR);
>  	}
> -	spin_unlock_irqrestore(&dev_priv->rps.lock, flags);
> +	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
>  }
>  
>  static int
> diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.h b/drivers/gpu/drm/i915/intel_ringbuffer.h
> index efc403d..f960805 100644
> --- a/drivers/gpu/drm/i915/intel_ringbuffer.h
> +++ b/drivers/gpu/drm/i915/intel_ringbuffer.h
> @@ -76,7 +76,7 @@ struct  intel_ring_buffer {
>  
>  	struct {
>  		u32	gt; /*  protected by dev_priv->irq_lock */
> -		u32	pm; /*  protected by dev_priv->rps.lock (sucks) */
> +		u32	pm; /*  protected by dev_priv->irq_lock */
>  	} irq_refcount;
>  	u32		irq_enable_mask;	/* bitmask to enable ring interrupt */
>  	u32		trace_irq_seqno;
> -- 
> 1.8.1.4
> 
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-- 
Ben Widawsky, Intel Open Source Technology Center



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