From: Daniel Vetter Date: Thu, 4 Jul 2013 21:35:25 +0000 (+0200) Subject: drm/i915: irq handlers don't need interrupt-safe spinlocks X-Git-Tag: v3.12-rc2~3^2~179^2~11 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d0ecd7e221c87514b1eca84b11fee1e262f5d816;p=kernel%2Fkernel-generic.git drm/i915: irq handlers don't need interrupt-safe spinlocks Since we only have one interrupt handler and interrupt handlers are non-reentrant. To drive the point really home give them all an _irq_handler suffix. This is a tiny micro-optimization but even more important it makes it clearer what locking we actually need. And in case someone screws this up: lockdep will catch hardirq vs. other context deadlocks. v2: Fix up compile fail. Reviewed-by: Paulo Zanoni Reviewed-by: Ben Widawsky Signed-off-by: Daniel Vetter --- diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index 69957f8..a7c0a73 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -656,14 +656,13 @@ static void i915_hotplug_work_func(struct work_struct *work) drm_kms_helper_hotplug_event(dev); } -static void ironlake_handle_rps_change(struct drm_device *dev) +static void ironlake_rps_change_irq_handler(struct drm_device *dev) { drm_i915_private_t *dev_priv = dev->dev_private; u32 busy_up, busy_down, max_avg, min_avg; u8 new_delay; - unsigned long flags; - spin_lock_irqsave(&mchdev_lock, flags); + spin_lock(&mchdev_lock); I915_WRITE16(MEMINTRSTS, I915_READ(MEMINTRSTS)); @@ -691,7 +690,7 @@ static void ironlake_handle_rps_change(struct drm_device *dev) if (ironlake_set_drps(dev, new_delay)) dev_priv->ips.cur_delay = new_delay; - spin_unlock_irqrestore(&mchdev_lock, flags); + spin_unlock(&mchdev_lock); return; } @@ -835,18 +834,17 @@ static void ivybridge_parity_work(struct work_struct *work) kfree(parity_event[1]); } -static void ivybridge_handle_parity_error(struct drm_device *dev) +static void ivybridge_parity_error_irq_handler(struct drm_device *dev) { drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private; - unsigned long flags; if (!HAS_L3_GPU_CACHE(dev)) return; - spin_lock_irqsave(&dev_priv->irq_lock, flags); + spin_lock(&dev_priv->irq_lock); dev_priv->gt_irq_mask |= GT_RENDER_L3_PARITY_ERROR_INTERRUPT; I915_WRITE(GTIMR, dev_priv->gt_irq_mask); - spin_unlock_irqrestore(&dev_priv->irq_lock, flags); + spin_unlock(&dev_priv->irq_lock); queue_work(dev_priv->wq, &dev_priv->l3_parity.error_work); } @@ -872,15 +870,13 @@ static void snb_gt_irq_handler(struct drm_device *dev, } if (gt_iir & GT_RENDER_L3_PARITY_ERROR_INTERRUPT) - ivybridge_handle_parity_error(dev); + ivybridge_parity_error_irq_handler(dev); } /* Legacy way of handling PM interrupts */ -static void gen6_queue_rps_work(struct drm_i915_private *dev_priv, - u32 pm_iir) +static void gen6_rps_irq_handler(struct drm_i915_private *dev_priv, + u32 pm_iir) { - unsigned long flags; - /* * IIR bits should never already be set because IMR should * prevent an interrupt from being shown in IIR. The warning @@ -891,11 +887,11 @@ static void gen6_queue_rps_work(struct drm_i915_private *dev_priv, * The mask bit in IMR is cleared by dev_priv->rps.work. */ - spin_lock_irqsave(&dev_priv->rps.lock, flags); + spin_lock(&dev_priv->rps.lock); dev_priv->rps.pm_iir |= pm_iir; I915_WRITE(GEN6_PMIMR, dev_priv->rps.pm_iir); POSTING_READ(GEN6_PMIMR); - spin_unlock_irqrestore(&dev_priv->rps.lock, flags); + spin_unlock(&dev_priv->rps.lock); queue_work(dev_priv->wq, &dev_priv->rps.work); } @@ -959,7 +955,7 @@ static void dp_aux_irq_handler(struct drm_device *dev) wake_up_all(&dev_priv->gmbus_wait_queue); } -/* Unlike gen6_queue_rps_work() from which this function is originally derived, +/* Unlike gen6_rps_irq_handler() from which this function is originally derived, * we must be able to deal with other PM interrupts. This is complicated because * of the way in which we use the masks to defer the RPS work (which for * posterity is necessary because of forcewake). @@ -967,9 +963,7 @@ static void dp_aux_irq_handler(struct drm_device *dev) static void hsw_pm_irq_handler(struct drm_i915_private *dev_priv, u32 pm_iir) { - unsigned long flags; - - spin_lock_irqsave(&dev_priv->rps.lock, flags); + spin_lock(&dev_priv->rps.lock); dev_priv->rps.pm_iir |= pm_iir & GEN6_PM_RPS_EVENTS; if (dev_priv->rps.pm_iir) { I915_WRITE(GEN6_PMIMR, dev_priv->rps.pm_iir); @@ -978,7 +972,7 @@ static void hsw_pm_irq_handler(struct drm_i915_private *dev_priv, /* TODO: if queue_work is slow, move it out of the spinlock */ queue_work(dev_priv->wq, &dev_priv->rps.work); } - spin_unlock_irqrestore(&dev_priv->rps.lock, flags); + spin_unlock(&dev_priv->rps.lock); if (pm_iir & ~GEN6_PM_RPS_EVENTS) { if (pm_iir & PM_VEBOX_USER_INTERRUPT) @@ -1060,7 +1054,7 @@ static irqreturn_t valleyview_irq_handler(int irq, void *arg) gmbus_irq_handler(dev); if (pm_iir & GEN6_PM_RPS_EVENTS) - gen6_queue_rps_work(dev_priv, pm_iir); + gen6_rps_irq_handler(dev_priv, pm_iir); I915_WRITE(GTIIR, gt_iir); I915_WRITE(GEN6_PMIIR, pm_iir); @@ -1298,7 +1292,7 @@ static irqreturn_t ivybridge_irq_handler(int irq, void *arg) if (IS_HASWELL(dev)) hsw_pm_irq_handler(dev_priv, pm_iir); else if (pm_iir & GEN6_PM_RPS_EVENTS) - gen6_queue_rps_work(dev_priv, pm_iir); + gen6_rps_irq_handler(dev_priv, pm_iir); I915_WRITE(GEN6_PMIIR, pm_iir); ret = IRQ_HANDLED; } @@ -1415,10 +1409,10 @@ static irqreturn_t ironlake_irq_handler(int irq, void *arg) } if (IS_GEN5(dev) && de_iir & DE_PCU_EVENT) - ironlake_handle_rps_change(dev); + ironlake_rps_change_irq_handler(dev); if (IS_GEN6(dev) && pm_iir & GEN6_PM_RPS_EVENTS) - gen6_queue_rps_work(dev_priv, pm_iir); + gen6_rps_irq_handler(dev_priv, pm_iir); I915_WRITE(GTIIR, gt_iir); I915_WRITE(DEIIR, de_iir);