Re: [PATCH 03/11] drm/i915: Add low level set of routines for programming PM IER/IIR/IMR register set

Tvrtko Ursulin
2016-06-27T15:46:02Z

On 27/06/16 13:16, akash.goel@intel.com wrote:
> From: Akash Goel <akash.goel@intel.com>
>
> So far PM IER/IIR/IMR registers were being used only for Turbo related
> interrupts. But interrupts coming from GuC also use the same set.
> As a precursor to supporting GuC interrupts, added new low level routines
> so as to allow sharing the programming of PM IER/IIR/IMR registers between
> Turbo & GuC.
> Also similar to PM IMR, maintaining a bitmask for PM IER register, to allow
> easy sharing of it between Turbo & GuC without involving a rmw operation.
>
> Suggested-by: Chris Wilson <chris@chris-wilson.co.uk>
> Signed-off-by: Akash Goel <akash.goel@intel.com>
> ---
> drivers/gpu/drm/i915/i915_drv.h | 1 +
> drivers/gpu/drm/i915/i915_irq.c | 55 ++++++++++++++++++++++++++++++++--------
> drivers/gpu/drm/i915/intel_drv.h | 6 +++++
> 3 files changed, 52 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
> index 9ef4919..85a7103 100644
> --- a/drivers/gpu/drm/i915/i915_drv.h
> +++ b/drivers/gpu/drm/i915/i915_drv.h
> @@ -1806,6 +1806,7 @@ struct drm_i915_private {
> };
> u32 gt_irq_mask;
> u32 pm_irq_mask;
> + u32 pm_ier_mask;
> u32 pm_rps_events;
> u32 pipestat_irq_mask[I915_MAX_PIPES];
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 4378a65..7316ab4 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -336,14 +336,52 @@ void gen6_disable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask)
> __gen6_disable_pm_irq(dev_priv, mask);
> }
>
> -void gen6_reset_rps_interrupts(struct drm_i915_private *dev_priv)
> +void gen6_reset_pm_interrupts(struct drm_i915_private *dev_priv,
> + uint32_t reset_mask)

Kernel prefers u32. It is not that overall i915 is clean in that
respect, but every time maintainers merge patches checkpatch shouts
about it, and more noise tougher it is to spot more important issues. I
would appreciate if u32 was used throughout.

> {
> i915_reg_t reg = gen6_pm_iir(dev_priv);
>
> - spin_lock_irq(&dev_priv->irq_lock);
> - I915_WRITE(reg, dev_priv->pm_rps_events);
> - I915_WRITE(reg, dev_priv->pm_rps_events);
> + assert_spin_locked(&dev_priv->irq_lock);
> +
> + I915_WRITE(reg, reset_mask);
> + I915_WRITE(reg, reset_mask);
> POSTING_READ(reg);
> +}
> +
> +void gen6_enable_pm_interrupts(struct drm_i915_private *dev_priv,
> + uint32_t enable_mask)
> +{
> + uint32_t new_val;
> +
> + assert_spin_locked(&dev_priv->irq_lock);
> +
> + new_val = dev_priv->pm_ier_mask;
> + new_val |= enable_mask;
> +
> + dev_priv->pm_ier_mask = new_val;
> + I915_WRITE(gen6_pm_ier(dev_priv), dev_priv->pm_ier_mask);
> + gen6_enable_pm_irq(dev_priv, enable_mask);

Hm, will this be confusing that we will have gen6_enable_pm_interrupts
and gen6_enable_pm_irq, so extremely similar names and same parameters,
but for different use?

Maybe rename the old one to gen6_unmask_pm_irq and name this one
gen6_enable_pm_irq ? If there is really need to have both. Or add some
kerneldoc explaining which one is used for what?

> +}
> +
> +void gen6_disable_pm_interrupts(struct drm_i915_private *dev_priv,
> + uint32_t disable_mask)
> +{
> + uint32_t new_val;
> +
> + assert_spin_locked(&dev_priv->irq_lock);
> +
> + new_val = dev_priv->pm_ier_mask;
> + new_val &= ~disable_mask;
> +
> + dev_priv->pm_ier_mask = new_val;
> + __gen6_disable_pm_irq(dev_priv, disable_mask);
> + I915_WRITE(gen6_pm_ier(dev_priv), dev_priv->pm_ier_mask);
> +}
> +
> +void gen6_reset_rps_interrupts(struct drm_i915_private *dev_priv)
> +{
> + spin_lock_irq(&dev_priv->irq_lock);
> + gen6_reset_pm_interrupts(dev_priv, dev_priv->pm_rps_events);
> dev_priv->rps.pm_iir = 0;
> spin_unlock_irq(&dev_priv->irq_lock);
> }
> @@ -355,9 +393,7 @@ void gen6_enable_rps_interrupts(struct drm_i915_private *dev_priv)
> WARN_ON(dev_priv->rps.pm_iir);
> WARN_ON(I915_READ(gen6_pm_iir(dev_priv)) & dev_priv->pm_rps_events);
> dev_priv->rps.interrupts_enabled = true;
> - I915_WRITE(gen6_pm_ier(dev_priv), I915_READ(gen6_pm_ier(dev_priv)) |
> - dev_priv->pm_rps_events);
> - gen6_enable_pm_irq(dev_priv, dev_priv->pm_rps_events);
> + gen6_enable_pm_interrupts(dev_priv, dev_priv->pm_rps_events);
>
> spin_unlock_irq(&dev_priv->irq_lock);
> }
> @@ -379,9 +415,7 @@ void gen6_disable_rps_interrupts(struct drm_i915_private *dev_priv)
>
> I915_WRITE(GEN6_PMINTRMSK, gen6_sanitize_rps_pm_mask(dev_priv, ~0));
>
> - __gen6_disable_pm_irq(dev_priv, dev_priv->pm_rps_events);
> - I915_WRITE(gen6_pm_ier(dev_priv), I915_READ(gen6_pm_ier(dev_priv)) &
> - ~dev_priv->pm_rps_events);
> + gen6_disable_pm_interrupts(dev_priv, dev_priv->pm_rps_events);
>
> spin_unlock_irq(&dev_priv->irq_lock);
>
> @@ -3770,6 +3804,7 @@ static void gen8_gt_irq_postinstall(struct drm_i915_private *dev_priv)
> gt_interrupts[0] |= GT_RENDER_L3_PARITY_ERROR_INTERRUPT;
>
> dev_priv->pm_irq_mask = 0xffffffff;
> + dev_priv->pm_ier_mask = 0x0;
> GEN8_IRQ_INIT_NDX(GT, 0, ~gt_interrupts[0], gt_interrupts[0]);
> GEN8_IRQ_INIT_NDX(GT, 1, ~gt_interrupts[1], gt_interrupts[1]);
> /*
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 3156d8d..2a013fc 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -1060,6 +1060,12 @@ void gen6_disable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask);
> void gen6_reset_rps_interrupts(struct drm_i915_private *dev_priv);
> void gen6_enable_rps_interrupts(struct drm_i915_private *dev_priv);
> void gen6_disable_rps_interrupts(struct drm_i915_private *dev_priv);
> +void gen6_reset_pm_interrupts(struct drm_i915_private *dev_priv,
> + uint32_t reset_mask);
> +void gen6_enable_pm_interrupts(struct drm_i915_private *dev_priv,
> + uint32_t enable_mask);
> +void gen6_disable_pm_interrupts(struct drm_i915_private *dev_priv,
> + uint32_t disable_mask);
> u32 gen6_sanitize_rps_pm_mask(struct drm_i915_private *dev_priv, u32 mask);
> void intel_runtime_pm_disable_interrupts(struct drm_i915_private *dev_priv);
> void intel_runtime_pm_enable_interrupts(struct drm_i915_private *dev_priv);
>

Regards,

Tvrtko