[Intel-gfx] [PATCH 2/6] drm/i915/gt: Reorganise gen8+ interrupt handler
Chris Wilson
chris at chris-wilson.co.uk
Tue Jan 28 12:27:26 UTC 2020
Quoting Mika Kuoppala (2020-01-28 12:20:46)
> Chris Wilson <chris at chris-wilson.co.uk> writes:
>
> > We always use a deferred bottom-half (either tasklet or irq_work) for
> > processing the response to an interrupt which means we can recombine the
> > GT irq ack+handler into one. This simplicity is important in later
> > patches as we will need to handle and then ack multiple interrupt levels
> > before acking the GT and master interrupts.
> >
> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > ---
> > drivers/gpu/drm/i915/gt/intel_gt_irq.c | 70 +++++++++++---------------
> > drivers/gpu/drm/i915/gt/intel_gt_irq.h | 3 +-
> > drivers/gpu/drm/i915/i915_irq.c | 10 +---
> > 3 files changed, 33 insertions(+), 50 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.c b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
> > index f796bdf1ed30..71873a4cafc0 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gt_irq.c
> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
> > @@ -286,59 +286,49 @@ void gen6_gt_irq_handler(struct intel_gt *gt, u32 gt_iir)
> > gen7_parity_error_irq_handler(gt, gt_iir);
> > }
> >
> > -void gen8_gt_irq_ack(struct intel_gt *gt, u32 master_ctl, u32 gt_iir[4])
> > +void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl)
> > {
> > void __iomem * const regs = gt->uncore->regs;
> > + u32 iir;
> >
> > if (master_ctl & (GEN8_GT_RCS_IRQ | GEN8_GT_BCS_IRQ)) {
> > - gt_iir[0] = raw_reg_read(regs, GEN8_GT_IIR(0));
> > - if (likely(gt_iir[0]))
> > - raw_reg_write(regs, GEN8_GT_IIR(0), gt_iir[0]);
> > - }
> > -
> > - if (master_ctl & (GEN8_GT_VCS0_IRQ | GEN8_GT_VCS1_IRQ)) {
> > - gt_iir[1] = raw_reg_read(regs, GEN8_GT_IIR(1));
> > - if (likely(gt_iir[1]))
> > - raw_reg_write(regs, GEN8_GT_IIR(1), gt_iir[1]);
> > - }
> > -
> > - if (master_ctl & (GEN8_GT_PM_IRQ | GEN8_GT_GUC_IRQ)) {
> > - gt_iir[2] = raw_reg_read(regs, GEN8_GT_IIR(2));
> > - if (likely(gt_iir[2]))
> > - raw_reg_write(regs, GEN8_GT_IIR(2), gt_iir[2]);
> > - }
> > -
> > - if (master_ctl & GEN8_GT_VECS_IRQ) {
> > - gt_iir[3] = raw_reg_read(regs, GEN8_GT_IIR(3));
> > - if (likely(gt_iir[3]))
> > - raw_reg_write(regs, GEN8_GT_IIR(3), gt_iir[3]);
> > - }
> > -}
> > -
> > -void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl, u32 gt_iir[4])
> > -{
> > - if (master_ctl & (GEN8_GT_RCS_IRQ | GEN8_GT_BCS_IRQ)) {
> > - cs_irq_handler(gt->engine_class[RENDER_CLASS][0],
> > - gt_iir[0] >> GEN8_RCS_IRQ_SHIFT);
> > - cs_irq_handler(gt->engine_class[COPY_ENGINE_CLASS][0],
> > - gt_iir[0] >> GEN8_BCS_IRQ_SHIFT);
> > + iir = raw_reg_read(regs, GEN8_GT_IIR(0));
> > + if (likely(iir)) {
> > + cs_irq_handler(gt->engine_class[RENDER_CLASS][0],
> > + iir >> GEN8_RCS_IRQ_SHIFT);
> > + cs_irq_handler(gt->engine_class[COPY_ENGINE_CLASS][0],
> > + iir >> GEN8_BCS_IRQ_SHIFT);
> > + raw_reg_write(regs, GEN8_GT_IIR(0), iir);
> > + }
> > }
> >
> > if (master_ctl & (GEN8_GT_VCS0_IRQ | GEN8_GT_VCS1_IRQ)) {
> > - cs_irq_handler(gt->engine_class[VIDEO_DECODE_CLASS][0],
> > - gt_iir[1] >> GEN8_VCS0_IRQ_SHIFT);
> > - cs_irq_handler(gt->engine_class[VIDEO_DECODE_CLASS][1],
> > - gt_iir[1] >> GEN8_VCS1_IRQ_SHIFT);
> > + iir = raw_reg_read(regs, GEN8_GT_IIR(1));
> > + if (likely(iir)) {
> > + cs_irq_handler(gt->engine_class[VIDEO_DECODE_CLASS][0],
> > + iir >> GEN8_VCS0_IRQ_SHIFT);
> > + cs_irq_handler(gt->engine_class[VIDEO_DECODE_CLASS][1],
> > + iir >> GEN8_VCS1_IRQ_SHIFT);
> > + raw_reg_write(regs, GEN8_GT_IIR(1), iir);
> > + }
> > }
> >
> > if (master_ctl & GEN8_GT_VECS_IRQ) {
> > - cs_irq_handler(gt->engine_class[VIDEO_ENHANCEMENT_CLASS][0],
> > - gt_iir[3] >> GEN8_VECS_IRQ_SHIFT);
> > + iir = raw_reg_read(regs, GEN8_GT_IIR(3));
> > + if (likely(iir)) {
> > + cs_irq_handler(gt->engine_class[VIDEO_ENHANCEMENT_CLASS][0],
> > + iir >> GEN8_VECS_IRQ_SHIFT);
> > + raw_reg_write(regs, GEN8_GT_IIR(3), iir);
> > + }
> > }
> >
> > if (master_ctl & (GEN8_GT_PM_IRQ | GEN8_GT_GUC_IRQ)) {
> > - gen6_rps_irq_handler(>->rps, gt_iir[2]);
> > - guc_irq_handler(>->uc.guc, gt_iir[2] >> 16);
> > + iir = raw_reg_read(regs, GEN8_GT_IIR(2));
> > + if (likely(iir)) {
> > + gen6_rps_irq_handler(>->rps, iir);
> > + guc_irq_handler(>->uc.guc, iir >> 16);
> > + raw_reg_write(regs, GEN8_GT_IIR(2), iir);
> > + }
> > }
> > }
> >
> > diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.h b/drivers/gpu/drm/i915/gt/intel_gt_irq.h
> > index 8f37593712c9..886c5cf408a2 100644
> > --- a/drivers/gpu/drm/i915/gt/intel_gt_irq.h
> > +++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.h
> > @@ -36,9 +36,8 @@ void gen5_gt_enable_irq(struct intel_gt *gt, u32 mask);
> >
> > void gen6_gt_irq_handler(struct intel_gt *gt, u32 gt_iir);
> >
> > -void gen8_gt_irq_ack(struct intel_gt *gt, u32 master_ctl, u32 gt_iir[4]);
> > +void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl);
> > void gen8_gt_irq_reset(struct intel_gt *gt);
> > -void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl, u32 gt_iir[4]);
> > void gen8_gt_irq_postinstall(struct intel_gt *gt);
> >
> > #endif /* INTEL_GT_IRQ_H */
> > diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> > index 87a6662abc1b..e40dd226fde8 100644
> > --- a/drivers/gpu/drm/i915/i915_irq.c
> > +++ b/drivers/gpu/drm/i915/i915_irq.c
> > @@ -1614,7 +1614,6 @@ static irqreturn_t cherryview_irq_handler(int irq, void *arg)
> > u32 master_ctl, iir;
> > u32 pipe_stats[I915_MAX_PIPES] = {};
> > u32 hotplug_status = 0;
> > - u32 gt_iir[4];
> > u32 ier = 0;
> >
> > master_ctl = I915_READ(GEN8_MASTER_IRQ) & ~GEN8_MASTER_IRQ_CONTROL;
> > @@ -1642,7 +1641,7 @@ static irqreturn_t cherryview_irq_handler(int irq, void *arg)
> > ier = I915_READ(VLV_IER);
> > I915_WRITE(VLV_IER, 0);
> >
> > - gen8_gt_irq_ack(&dev_priv->gt, master_ctl, gt_iir);
> > + gen8_gt_irq_handler(&dev_priv->gt, master_ctl);
> >
> > if (iir & I915_DISPLAY_PORT_INTERRUPT)
> > hotplug_status = i9xx_hpd_irq_ack(dev_priv);
> > @@ -1666,8 +1665,6 @@ static irqreturn_t cherryview_irq_handler(int irq, void *arg)
> > I915_WRITE(VLV_IER, ier);
> > I915_WRITE(GEN8_MASTER_IRQ, GEN8_MASTER_IRQ_CONTROL);
> >
> > - gen8_gt_irq_handler(&dev_priv->gt, master_ctl, gt_iir);
> > -
> > if (hotplug_status)
> > i9xx_hpd_irq_handler(dev_priv, hotplug_status);
> >
> > @@ -2396,7 +2393,6 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
> > struct drm_i915_private *dev_priv = arg;
> > void __iomem * const regs = dev_priv->uncore.regs;
> > u32 master_ctl;
> > - u32 gt_iir[4];
> >
> > if (!intel_irqs_enabled(dev_priv))
> > return IRQ_NONE;
> > @@ -2408,7 +2404,7 @@ static irqreturn_t gen8_irq_handler(int irq, void *arg)
> > }
> >
> > /* Find, clear, then process each source of interrupt */
>
> /* Find, process and then clear each source of interrupt */
The order is still ack / process, and that is quite important for
allowing interrupt delivery as we process. It's just that we use
bottom-halves rather than a local deferral.
/* Find, clear, then process (via bottom-halves) each source of interrupt */
-Chris
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