[Intel-gfx] [PATCH 8/9] drm/i915/bdw: Implement a basic PM interrupt handler

Rodrigo Vivi rodrigo.vivi at gmail.com
Thu Feb 6 15:15:12 CET 2014


On Wed, Jan 29, 2014 at 2:25 AM, Ben Widawsky
<benjamin.widawsky at intel.com> wrote:
> Almost all of it is reusable from the existing code. The primary
> difference is we need to do even less in the interrupt handler, since
> interrupts are not shared in the same way.
>
> The patch is mostly a copy-paste of the existing snb+ code, with updates
> to the relevant parts requiring changes to the interrupt handling. As
> such it /should/ be relatively trivial. It's highly likely that I missed
> some places where I need a gen8 version of the PM interrupts, but it has
> become invisible to me by now.
>
> This patch could probably be split into adding the new functions,
> followed by actually handling the interrupts. Since the code is
> currently disabled (and broken) I think the patch stands better by
> itself.
>
> Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
> ---
>  drivers/gpu/drm/i915/i915_irq.c  | 80 ++++++++++++++++++++++++++++++++++++++--
>  drivers/gpu/drm/i915/i915_reg.h  |  1 +
>  drivers/gpu/drm/i915/intel_drv.h |  2 +
>  drivers/gpu/drm/i915/intel_pm.c  | 39 +++++++++++++++++++-
>  4 files changed, 117 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 72ade87..ab0c7ac 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -214,6 +214,53 @@ static bool ivb_can_enable_err_int(struct drm_device *dev)
>         return true;
>  }
>
> +/**
> +  * bdw_update_pm_irq - update GT interrupt 2
> +  * @dev_priv: driver private
> +  * @interrupt_mask: mask of interrupt bits to update
> +  * @enabled_irq_mask: mask of interrupt bits to enable
> +  *
> +  * Copied from the snb function, updated with relevant register offsets
> +  */
> +static void bdw_update_pm_irq(struct drm_i915_private *dev_priv,
> +                             uint32_t interrupt_mask,
> +                             uint32_t enabled_irq_mask)
> +{
> +       uint32_t new_val;
> +
> +       assert_spin_locked(&dev_priv->irq_lock);
> +
> +       if (dev_priv->pc8.irqs_disabled) {
> +               WARN(1, "IRQs disabled\n");
> +               dev_priv->pc8.regsave.gen6_pmimr &= ~interrupt_mask;
> +               dev_priv->pc8.regsave.gen6_pmimr |= (~enabled_irq_mask &
> +                                                    interrupt_mask);
> +               return;
> +       }
> +
> +       new_val = dev_priv->pm_irq_mask;
> +       new_val &= ~interrupt_mask;
> +       new_val |= (~enabled_irq_mask & interrupt_mask);
> +
> +       if (new_val != dev_priv->pm_irq_mask) {
> +               dev_priv->pm_irq_mask = new_val;
> +               I915_WRITE(GEN8_GT_IMR(2), I915_READ(GEN8_GT_IMR(2)) |
> +                                          dev_priv->pm_irq_mask);
> +               POSTING_READ(GEN8_GT_IMR(2));
> +       }
> +}
> +
> +void bdw_enable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask)
> +{
> +       bdw_update_pm_irq(dev_priv, mask, mask);
> +}
> +
> +void bdw_disable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask)
> +{
> +       bdw_update_pm_irq(dev_priv, mask, 0);
> +}
> +
> +
>  static bool cpt_can_enable_serr_int(struct drm_device *dev)
>  {
>         struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -997,11 +1044,15 @@ static void gen6_pm_rps_work(struct work_struct *work)
>         pm_iir = dev_priv->rps.pm_iir;
>         dev_priv->rps.pm_iir = 0;
>         /* Make sure not to corrupt PMIMR state used by ringbuffer code */
> -       snb_enable_pm_irq(dev_priv, GEN6_PM_RPS_EVENTS);
> +       if (IS_BROADWELL(dev_priv->dev))
> +               bdw_enable_pm_irq(dev_priv, GEN6_PM_RPS_EVENTS);
> +       else {
> +               /* Make sure we didn't queue anything we're not going to process. */
> +               snb_enable_pm_irq(dev_priv, GEN6_PM_RPS_EVENTS);

inverted lines since comment sounds to be related to above line.

> +               WARN_ON(pm_iir & ~GEN6_PM_RPS_EVENTS);
> +       }
>         spin_unlock_irq(&dev_priv->irq_lock);
>
> -       /* Make sure we didn't queue anything we're not going to process. */
> -       WARN_ON(pm_iir & ~GEN6_PM_RPS_EVENTS);
>
>         if ((pm_iir & GEN6_PM_RPS_EVENTS) == 0)
>                 return;
> @@ -1192,6 +1243,19 @@ static void snb_gt_irq_handler(struct drm_device *dev,
>                 ivybridge_parity_error_irq_handler(dev, gt_iir);
>  }
>
> +static void gen8_rps_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir)
> +{
> +       if ((pm_iir & GEN6_PM_RPS_EVENTS) == 0)
> +               return;
> +
> +       spin_lock(&dev_priv->irq_lock);
> +       dev_priv->rps.pm_iir |= pm_iir & GEN6_PM_RPS_EVENTS;
> +       bdw_disable_pm_irq(dev_priv, pm_iir & GEN6_PM_RPS_EVENTS);
> +       spin_unlock(&dev_priv->irq_lock);
> +
> +       queue_work(dev_priv->wq, &dev_priv->rps.work);

sorry if this is a stupid question, but don't we need the vebox part here?

> +}
> +
>  static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
>                                        struct drm_i915_private *dev_priv,
>                                        u32 master_ctl)
> @@ -1227,6 +1291,16 @@ static irqreturn_t gen8_gt_irq_handler(struct drm_device *dev,
>                         DRM_ERROR("The master control interrupt lied (GT1)!\n");
>         }
>
> +       if (master_ctl & GEN8_GT_PM_IRQ) {
> +               tmp = I915_READ(GEN8_GT_IIR(2));
> +               if (tmp & GEN6_PM_RPS_EVENTS) {
> +                       ret = IRQ_HANDLED;
> +                       gen8_rps_irq_handler(dev_priv, tmp);
> +                       I915_WRITE(GEN8_GT_IIR(1), tmp & GEN6_PM_RPS_EVENTS);
> +               } else
> +                       DRM_ERROR("The master control interrupt lied (PM)!\n");
> +       }
> +
>         if (master_ctl & GEN8_GT_VECS_IRQ) {
>                 tmp = I915_READ(GEN8_GT_IIR(3));
>                 if (tmp) {
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index d77720e..f9e582e 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -4024,6 +4024,7 @@
>  #define  GEN8_DE_PIPE_A_IRQ            (1<<16)
>  #define  GEN8_DE_PIPE_IRQ(pipe)                (1<<(16+pipe))
>  #define  GEN8_GT_VECS_IRQ              (1<<6)
> +#define  GEN8_GT_PM_IRQ                        (1<<4)
>  #define  GEN8_GT_VCS2_IRQ              (1<<3)
>  #define  GEN8_GT_VCS1_IRQ              (1<<2)
>  #define  GEN8_GT_BCS_IRQ               (1<<1)
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 44067bc..7b49779 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -608,6 +608,8 @@ void ilk_enable_gt_irq(struct drm_i915_private *dev_priv, uint32_t mask);
>  void ilk_disable_gt_irq(struct drm_i915_private *dev_priv, uint32_t mask);
>  void snb_enable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask);
>  void snb_disable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask);
> +void bdw_enable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask);
> +void bdw_disable_pm_irq(struct drm_i915_private *dev_priv, uint32_t mask);
>  void hsw_pc8_disable_interrupts(struct drm_device *dev);
>  void hsw_pc8_restore_interrupts(struct drm_device *dev);
>
> diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
> index deaaaf2..a5c9142 100644
> --- a/drivers/gpu/drm/i915/intel_pm.c
> +++ b/drivers/gpu/drm/i915/intel_pm.c
> @@ -3091,6 +3091,25 @@ void valleyview_set_rps(struct drm_device *dev, u8 val)
>         trace_intel_gpu_freq_change(vlv_gpu_freq(dev_priv, val));
>  }
>
> +static void gen8_disable_rps_interrupts(struct drm_device *dev)
> +{
> +       struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +       I915_WRITE(GEN6_PMINTRMSK, 0xffffffff);
> +       I915_WRITE(GEN8_GT_IER(2), I915_READ(GEN8_GT_IER(2)) &
> +                                  ~GEN6_PM_RPS_EVENTS);
> +       /* Complete PM interrupt masking here doesn't race with the rps work
> +        * item again unmasking PM interrupts because that is using a different
> +        * 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->irq_lock);
> +       dev_priv->rps.pm_iir = 0;
> +       spin_unlock_irq(&dev_priv->irq_lock);
> +
> +       I915_WRITE(GEN8_GT_IIR(2), GEN6_PM_RPS_EVENTS);
> +}
> +
>  static void gen6_disable_rps_interrupts(struct drm_device *dev)
>  {
>         struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -3116,7 +3135,10 @@ static void gen6_disable_rps(struct drm_device *dev)
>         I915_WRITE(GEN6_RC_CONTROL, 0);
>         I915_WRITE(GEN6_RPNSWREQ, 1 << 31);
>
> -       gen6_disable_rps_interrupts(dev);
> +       if (IS_BROADWELL(dev))
> +               gen8_disable_rps_interrupts(dev);
> +       else
> +               gen6_disable_rps_interrupts(dev);
>  }
>
>  static void valleyview_disable_rps(struct drm_device *dev)
> @@ -3161,6 +3183,19 @@ int intel_enable_rc6(const struct drm_device *dev)
>                 return INTEL_RC6_ENABLE;
>  }
>
> +static void gen8_enable_rps_interrupts(struct drm_device *dev)
> +{
> +       struct drm_i915_private *dev_priv = dev->dev_private;
> +
> +       spin_lock_irq(&dev_priv->irq_lock);
> +       WARN_ON(dev_priv->rps.pm_iir);
> +       bdw_enable_pm_irq(dev_priv, GEN6_PM_RPS_EVENTS);
> +       I915_WRITE(GEN8_GT_IIR(2), GEN6_PM_RPS_EVENTS);
> +       spin_unlock_irq(&dev_priv->irq_lock);
> +
> +       I915_WRITE(GEN6_PMINTRMSK, ~GEN6_PM_RPS_EVENTS);
> +}
> +
>  static void gen6_enable_rps_interrupts(struct drm_device *dev)
>  {
>         struct drm_i915_private *dev_priv = dev->dev_private;
> @@ -3263,7 +3298,7 @@ static void gen8_enable_rps(struct drm_device *dev)
>
>         gen6_set_rps(dev, (I915_READ(GEN6_GT_PERF_STATUS) & 0xff00) >> 8);
>
> -       gen6_enable_rps_interrupts(dev);
> +       gen8_enable_rps_interrupts(dev);
>
>         gen6_gt_force_wake_put(dev_priv, FORCEWAKE_ALL);
>  }
> --
> 1.8.5.3
>
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> Intel-gfx at lists.freedesktop.org
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with those explained or fixed feel free to use:

Reviewed-by: Rodrigo Vivi <rodrigo.vivi at gmail.com>

-- 
Rodrigo Vivi
Blog: http://blog.vivi.eng.br



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