[Intel-gfx] [PATCH v2] drm/i915/gt: Move CS interrupt handler to the backend

Tvrtko Ursulin tvrtko.ursulin at linux.intel.com
Tue Feb 2 16:33:22 UTC 2021


On 02/02/2021 16:15, Chris Wilson wrote:
> The different submission backends each have their own preferred
> behaviour and interrupt setup. Let each handle their own interrupts.
> 
> This becomes more useful later as we to extract the use of auxiliary
> state in the interrupt handler that is backend specific.
> 
> v2: An overabundance of caution is always justified; put a barrier on
> updating the irq handler so that we know that the next interrupt will
> be redirected towards ourselves.
> 
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>   drivers/gpu/drm/i915/gt/intel_engine_cs.c     |  7 ++
>   drivers/gpu/drm/i915/gt/intel_engine_types.h  | 14 +---
>   .../drm/i915/gt/intel_execlists_submission.c  | 40 +++++++++
>   drivers/gpu/drm/i915/gt/intel_gt_irq.c        | 82 ++++++-------------
>   drivers/gpu/drm/i915/gt/intel_gt_irq.h        | 22 +++++
>   .../gpu/drm/i915/gt/intel_ring_submission.c   |  7 ++
>   drivers/gpu/drm/i915/gt/intel_rps.c           |  2 +-
>   .../gpu/drm/i915/gt/uc/intel_guc_submission.c | 10 ++-
>   drivers/gpu/drm/i915/i915_irq.c               |  8 +-
>   9 files changed, 118 insertions(+), 74 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> index c7d17f8767a1..e06ae4ae1710 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
> @@ -255,6 +255,11 @@ static void intel_engine_sanitize_mmio(struct intel_engine_cs *engine)
>   	intel_engine_set_hwsp_writemask(engine, ~0u);
>   }
>   
> +static void nop_irq_handler(struct intel_engine_cs *engine, u32 iir)
> +{
> +	GEM_DEBUG_WARN_ON(iir);
> +}
> +
>   static int intel_engine_setup(struct intel_gt *gt, enum intel_engine_id id)
>   {
>   	const struct engine_info *info = &intel_engines[id];
> @@ -292,6 +297,8 @@ static int intel_engine_setup(struct intel_gt *gt, enum intel_engine_id id)
>   	engine->hw_id = info->hw_id;
>   	engine->guc_id = MAKE_GUC_ID(info->class, info->instance);
>   
> +	engine->irq_handler = nop_irq_handler;
> +
>   	engine->class = info->class;
>   	engine->instance = info->instance;
>   	__sprint_engine_name(engine);
> diff --git a/drivers/gpu/drm/i915/gt/intel_engine_types.h b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> index 9d59de5c559a..7fd035d45263 100644
> --- a/drivers/gpu/drm/i915/gt/intel_engine_types.h
> +++ b/drivers/gpu/drm/i915/gt/intel_engine_types.h
> @@ -402,6 +402,7 @@ struct intel_engine_cs {
>   	u32		irq_enable_mask; /* bitmask to enable ring interrupt */
>   	void		(*irq_enable)(struct intel_engine_cs *engine);
>   	void		(*irq_disable)(struct intel_engine_cs *engine);
> +	void		(*irq_handler)(struct intel_engine_cs *engine, u32 iir);
>   
>   	void		(*sanitize)(struct intel_engine_cs *engine);
>   	int		(*resume)(struct intel_engine_cs *engine);
> @@ -481,10 +482,9 @@ struct intel_engine_cs {
>   #define I915_ENGINE_HAS_PREEMPTION   BIT(2)
>   #define I915_ENGINE_HAS_SEMAPHORES   BIT(3)
>   #define I915_ENGINE_HAS_TIMESLICES   BIT(4)
> -#define I915_ENGINE_NEEDS_BREADCRUMB_TASKLET BIT(5)
> -#define I915_ENGINE_IS_VIRTUAL       BIT(6)
> -#define I915_ENGINE_HAS_RELATIVE_MMIO BIT(7)
> -#define I915_ENGINE_REQUIRES_CMD_PARSER BIT(8)
> +#define I915_ENGINE_IS_VIRTUAL       BIT(5)
> +#define I915_ENGINE_HAS_RELATIVE_MMIO BIT(6)
> +#define I915_ENGINE_REQUIRES_CMD_PARSER BIT(7)
>   	unsigned int flags;
>   
>   	/*
> @@ -588,12 +588,6 @@ intel_engine_has_timeslices(const struct intel_engine_cs *engine)
>   	return engine->flags & I915_ENGINE_HAS_TIMESLICES;
>   }
>   
> -static inline bool
> -intel_engine_needs_breadcrumb_tasklet(const struct intel_engine_cs *engine)
> -{
> -	return engine->flags & I915_ENGINE_NEEDS_BREADCRUMB_TASKLET;
> -}
> -
>   static inline bool
>   intel_engine_is_virtual(const struct intel_engine_cs *engine)
>   {
> diff --git a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> index 4ddd2099a931..05846f97f1af 100644
> --- a/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> +++ b/drivers/gpu/drm/i915/gt/intel_execlists_submission.c
> @@ -2394,6 +2394,45 @@ static void execlists_submission_tasklet(struct tasklet_struct *t)
>   	rcu_read_unlock();
>   }
>   
> +static void execlists_irq_handler(struct intel_engine_cs *engine, u32 iir)
> +{
> +	bool tasklet = false;
> +
> +	if (unlikely(iir & GT_CS_MASTER_ERROR_INTERRUPT)) {
> +		u32 eir;
> +
> +		/* Upper 16b are the enabling mask, rsvd for internal errors */
> +		eir = ENGINE_READ(engine, RING_EIR) & GENMASK(15, 0);
> +		ENGINE_TRACE(engine, "CS error: %x\n", eir);
> +
> +		/* Disable the error interrupt until after the reset */
> +		if (likely(eir)) {
> +			ENGINE_WRITE(engine, RING_EMR, ~0u);
> +			ENGINE_WRITE(engine, RING_EIR, eir);
> +			WRITE_ONCE(engine->execlists.error_interrupt, eir);
> +			tasklet = true;
> +		}
> +	}
> +
> +	if (iir & GT_WAIT_SEMAPHORE_INTERRUPT) {
> +		WRITE_ONCE(engine->execlists.yield,
> +			   ENGINE_READ_FW(engine, RING_EXECLIST_STATUS_HI));
> +		ENGINE_TRACE(engine, "semaphore yield: %08x\n",
> +			     engine->execlists.yield);
> +		if (del_timer(&engine->execlists.timer))
> +			tasklet = true;
> +	}
> +
> +	if (iir & GT_CONTEXT_SWITCH_INTERRUPT)
> +		tasklet = true;
> +
> +	if (iir & GT_RENDER_USER_INTERRUPT)
> +		intel_engine_signal_breadcrumbs(engine);
> +
> +	if (tasklet)
> +		tasklet_hi_schedule(&engine->execlists.tasklet);
> +}
> +
>   static void __execlists_kick(struct intel_engine_execlists *execlists)
>   {
>   	/* Kick the tasklet for some interrupt coalescing and reset handling */
> @@ -3146,6 +3185,7 @@ logical_ring_default_vfuncs(struct intel_engine_cs *engine)
>   		 * until a more refined solution exists.
>   		 */
>   	}
> +	intel_engine_set_irq_handler(engine, execlists_irq_handler);
>   
>   	engine->flags |= I915_ENGINE_SUPPORTS_STATS;
>   	if (!intel_vgpu_active(engine->i915)) {
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.c b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
> index 9fc6c912a4e5..f5aa31ae8f6c 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_irq.c
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.c
> @@ -20,48 +20,6 @@ static void guc_irq_handler(struct intel_guc *guc, u16 iir)
>   		intel_guc_to_host_event_handler(guc);
>   }
>   
> -static void
> -cs_irq_handler(struct intel_engine_cs *engine, u32 iir)
> -{
> -	bool tasklet = false;
> -
> -	if (unlikely(iir & GT_CS_MASTER_ERROR_INTERRUPT)) {
> -		u32 eir;
> -
> -		/* Upper 16b are the enabling mask, rsvd for internal errors */
> -		eir = ENGINE_READ(engine, RING_EIR) & GENMASK(15, 0);
> -		ENGINE_TRACE(engine, "CS error: %x\n", eir);
> -
> -		/* Disable the error interrupt until after the reset */
> -		if (likely(eir)) {
> -			ENGINE_WRITE(engine, RING_EMR, ~0u);
> -			ENGINE_WRITE(engine, RING_EIR, eir);
> -			WRITE_ONCE(engine->execlists.error_interrupt, eir);
> -			tasklet = true;
> -		}
> -	}
> -
> -	if (iir & GT_WAIT_SEMAPHORE_INTERRUPT) {
> -		WRITE_ONCE(engine->execlists.yield,
> -			   ENGINE_READ_FW(engine, RING_EXECLIST_STATUS_HI));
> -		ENGINE_TRACE(engine, "semaphore yield: %08x\n",
> -			     engine->execlists.yield);
> -		if (del_timer(&engine->execlists.timer))
> -			tasklet = true;
> -	}
> -
> -	if (iir & GT_CONTEXT_SWITCH_INTERRUPT)
> -		tasklet = true;
> -
> -	if (iir & GT_RENDER_USER_INTERRUPT) {
> -		intel_engine_signal_breadcrumbs(engine);
> -		tasklet |= intel_engine_needs_breadcrumb_tasklet(engine);
> -	}
> -
> -	if (tasklet)
> -		tasklet_hi_schedule(&engine->execlists.tasklet);
> -}
> -
>   static u32
>   gen11_gt_engine_identity(struct intel_gt *gt,
>   			 const unsigned int bank, const unsigned int bit)
> @@ -122,7 +80,7 @@ gen11_engine_irq_handler(struct intel_gt *gt, const u8 class,
>   		engine = NULL;
>   
>   	if (likely(engine))
> -		return cs_irq_handler(engine, iir);
> +		return intel_engine_cs_irq(engine, iir);
>   
>   	WARN_ONCE(1, "unhandled engine interrupt class=0x%x, instance=0x%x\n",
>   		  class, instance);
> @@ -275,9 +233,12 @@ void gen11_gt_irq_postinstall(struct intel_gt *gt)
>   void gen5_gt_irq_handler(struct intel_gt *gt, u32 gt_iir)
>   {
>   	if (gt_iir & GT_RENDER_USER_INTERRUPT)
> -		intel_engine_signal_breadcrumbs(gt->engine_class[RENDER_CLASS][0]);
> +		intel_engine_cs_irq(gt->engine_class[RENDER_CLASS][0],
> +				    gt_iir);
> +
>   	if (gt_iir & ILK_BSD_USER_INTERRUPT)
> -		intel_engine_signal_breadcrumbs(gt->engine_class[VIDEO_DECODE_CLASS][0]);
> +		intel_engine_cs_irq(gt->engine_class[VIDEO_DECODE_CLASS][0],
> +				    gt_iir);
>   }
>   
>   static void gen7_parity_error_irq_handler(struct intel_gt *gt, u32 iir)
> @@ -301,11 +262,16 @@ static void gen7_parity_error_irq_handler(struct intel_gt *gt, u32 iir)
>   void gen6_gt_irq_handler(struct intel_gt *gt, u32 gt_iir)
>   {
>   	if (gt_iir & GT_RENDER_USER_INTERRUPT)
> -		intel_engine_signal_breadcrumbs(gt->engine_class[RENDER_CLASS][0]);
> +		intel_engine_cs_irq(gt->engine_class[RENDER_CLASS][0],
> +				    gt_iir);
> +
>   	if (gt_iir & GT_BSD_USER_INTERRUPT)
> -		intel_engine_signal_breadcrumbs(gt->engine_class[VIDEO_DECODE_CLASS][0]);
> +		intel_engine_cs_irq(gt->engine_class[VIDEO_DECODE_CLASS][0],
> +				    gt_iir);
> +
>   	if (gt_iir & GT_BLT_USER_INTERRUPT)
> -		intel_engine_signal_breadcrumbs(gt->engine_class[COPY_ENGINE_CLASS][0]);
> +		intel_engine_cs_irq(gt->engine_class[COPY_ENGINE_CLASS][0],
> +				    gt_iir);
>   
>   	if (gt_iir & (GT_BLT_CS_ERROR_INTERRUPT |
>   		      GT_BSD_CS_ERROR_INTERRUPT |
> @@ -324,10 +290,10 @@ void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl)
>   	if (master_ctl & (GEN8_GT_RCS_IRQ | GEN8_GT_BCS_IRQ)) {
>   		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);
> +			intel_engine_cs_irq(gt->engine_class[RENDER_CLASS][0],
> +					    iir >> GEN8_RCS_IRQ_SHIFT);
> +			intel_engine_cs_irq(gt->engine_class[COPY_ENGINE_CLASS][0],
> +					    iir >> GEN8_BCS_IRQ_SHIFT);
>   			raw_reg_write(regs, GEN8_GT_IIR(0), iir);
>   		}
>   	}
> @@ -335,10 +301,10 @@ void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl)
>   	if (master_ctl & (GEN8_GT_VCS0_IRQ | GEN8_GT_VCS1_IRQ)) {
>   		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);
> +			intel_engine_cs_irq(gt->engine_class[VIDEO_DECODE_CLASS][0],
> +					    iir >> GEN8_VCS0_IRQ_SHIFT);
> +			intel_engine_cs_irq(gt->engine_class[VIDEO_DECODE_CLASS][1],
> +					    iir >> GEN8_VCS1_IRQ_SHIFT);
>   			raw_reg_write(regs, GEN8_GT_IIR(1), iir);
>   		}
>   	}
> @@ -346,8 +312,8 @@ void gen8_gt_irq_handler(struct intel_gt *gt, u32 master_ctl)
>   	if (master_ctl & GEN8_GT_VECS_IRQ) {
>   		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);
> +			intel_engine_cs_irq(gt->engine_class[VIDEO_ENHANCEMENT_CLASS][0],
> +					    iir >> GEN8_VECS_IRQ_SHIFT);
>   			raw_reg_write(regs, GEN8_GT_IIR(3), iir);
>   		}
>   	}
> diff --git a/drivers/gpu/drm/i915/gt/intel_gt_irq.h b/drivers/gpu/drm/i915/gt/intel_gt_irq.h
> index f667e976fb2b..894efd471e93 100644
> --- a/drivers/gpu/drm/i915/gt/intel_gt_irq.h
> +++ b/drivers/gpu/drm/i915/gt/intel_gt_irq.h
> @@ -8,6 +8,8 @@
>   
>   #include <linux/types.h>
>   
> +#include "intel_engine_types.h"
> +
>   struct intel_gt;
>   
>   #define GEN8_GT_IRQS (GEN8_GT_RCS_IRQ | \
> @@ -39,4 +41,24 @@ 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_postinstall(struct intel_gt *gt);
>   
> +static inline void intel_engine_cs_irq(struct intel_engine_cs *engine, u32 iir)
> +{
> +	engine->irq_handler(engine, iir);
> +}
> +
> +static inline void
> +intel_engine_set_irq_handler(struct intel_engine_cs *engine,
> +			     void (*fn)(struct intel_engine_cs *engine,
> +					u32 iir))
> +{
> +	/*
> +	 * As the interrupt is live as allocate and setup the engines,
> +	 * err on the side of caution and apply barriers to updating
> +	 * the irq handler callback, so that we assured that before
> +	 * we do use the engine, we will receive interrupts to ourselves.
> +	 */
> +	smp_store_mb(engine->irq_handler, fn);
> +}
> +
> +
>   #endif /* INTEL_GT_IRQ_H */
> diff --git a/drivers/gpu/drm/i915/gt/intel_ring_submission.c b/drivers/gpu/drm/i915/gt/intel_ring_submission.c
> index 3cb2ce503544..3673f61c0813 100644
> --- a/drivers/gpu/drm/i915/gt/intel_ring_submission.c
> +++ b/drivers/gpu/drm/i915/gt/intel_ring_submission.c
> @@ -997,10 +997,17 @@ static void ring_release(struct intel_engine_cs *engine)
>   	intel_timeline_put(engine->legacy.timeline);
>   }
>   
> +static void irq_handler(struct intel_engine_cs *engine, u32 iir)
> +{
> +	intel_engine_signal_breadcrumbs(engine);
> +}
> +
>   static void setup_irq(struct intel_engine_cs *engine)
>   {
>   	struct drm_i915_private *i915 = engine->i915;
>   
> +	intel_engine_set_irq_handler(engine, irq_handler);
> +
>   	if (INTEL_GEN(i915) >= 6) {
>   		engine->irq_enable = gen6_irq_enable;
>   		engine->irq_disable = gen6_irq_disable;
> diff --git a/drivers/gpu/drm/i915/gt/intel_rps.c b/drivers/gpu/drm/i915/gt/intel_rps.c
> index 405d814e9040..4ba6a33f65cf 100644
> --- a/drivers/gpu/drm/i915/gt/intel_rps.c
> +++ b/drivers/gpu/drm/i915/gt/intel_rps.c
> @@ -1774,7 +1774,7 @@ void gen6_rps_irq_handler(struct intel_rps *rps, u32 pm_iir)
>   		return;
>   
>   	if (pm_iir & PM_VEBOX_USER_INTERRUPT)
> -		intel_engine_signal_breadcrumbs(gt->engine[VECS0]);
> +		intel_engine_cs_irq(gt->engine[VECS0], pm_iir);
>   
>   	if (pm_iir & PM_VEBOX_CS_ERROR_INTERRUPT)
>   		DRM_DEBUG("Command parser error, pm_iir 0x%08x\n", pm_iir);
> diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> index 17b551a0c89f..838e12b42009 100644
> --- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> +++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
> @@ -264,6 +264,14 @@ static void guc_submission_tasklet(struct tasklet_struct *t)
>   	spin_unlock_irqrestore(&engine->active.lock, flags);
>   }
>   
> +static void cs_irq_handler(struct intel_engine_cs *engine, u32 iir)
> +{
> +	if (iir & GT_RENDER_USER_INTERRUPT) {
> +		intel_engine_signal_breadcrumbs(engine);
> +		tasklet_hi_schedule(&engine->execlists.tasklet);
> +	}
> +}
> +
>   static void guc_reset_prepare(struct intel_engine_cs *engine)
>   {
>   	struct intel_engine_execlists * const execlists = &engine->execlists;
> @@ -645,7 +653,6 @@ static void guc_default_vfuncs(struct intel_engine_cs *engine)
>   	}
>   	engine->set_default_submission = guc_set_default_submission;
>   
> -	engine->flags |= I915_ENGINE_NEEDS_BREADCRUMB_TASKLET;
>   	engine->flags |= I915_ENGINE_HAS_PREEMPTION;
>   
>   	/*
> @@ -681,6 +688,7 @@ static void rcs_submission_override(struct intel_engine_cs *engine)
>   static inline void guc_default_irqs(struct intel_engine_cs *engine)
>   {
>   	engine->irq_keep_mask = GT_RENDER_USER_INTERRUPT;
> +	intel_engine_set_irq_handler(engine, cs_irq_handler);
>   }
>   
>   int intel_guc_submission_setup(struct intel_engine_cs *engine)
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 9d47da8ec86d..37a48402adc1 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -3954,7 +3954,7 @@ static irqreturn_t i8xx_irq_handler(int irq, void *arg)
>   		intel_uncore_write16(&dev_priv->uncore, GEN2_IIR, iir);
>   
>   		if (iir & I915_USER_INTERRUPT)
> -			intel_engine_signal_breadcrumbs(dev_priv->gt.engine[RCS0]);
> +			intel_engine_cs_irq(dev_priv->gt.engine[RCS0], iir);
>   
>   		if (iir & I915_MASTER_ERROR_INTERRUPT)
>   			i8xx_error_irq_handler(dev_priv, eir, eir_stuck);
> @@ -4062,7 +4062,7 @@ static irqreturn_t i915_irq_handler(int irq, void *arg)
>   		intel_uncore_write(&dev_priv->uncore, GEN2_IIR, iir);
>   
>   		if (iir & I915_USER_INTERRUPT)
> -			intel_engine_signal_breadcrumbs(dev_priv->gt.engine[RCS0]);
> +			intel_engine_cs_irq(dev_priv->gt.engine[RCS0], iir);
>   
>   		if (iir & I915_MASTER_ERROR_INTERRUPT)
>   			i9xx_error_irq_handler(dev_priv, eir, eir_stuck);
> @@ -4207,10 +4207,10 @@ static irqreturn_t i965_irq_handler(int irq, void *arg)
>   		intel_uncore_write(&dev_priv->uncore, GEN2_IIR, iir);
>   
>   		if (iir & I915_USER_INTERRUPT)
> -			intel_engine_signal_breadcrumbs(dev_priv->gt.engine[RCS0]);
> +			intel_engine_cs_irq(dev_priv->gt.engine[RCS0], iir);
>   
>   		if (iir & I915_BSD_USER_INTERRUPT)
> -			intel_engine_signal_breadcrumbs(dev_priv->gt.engine[VCS0]);
> +			intel_engine_cs_irq(dev_priv->gt.engine[VCS0], iir);
>   
>   		if (iir & I915_MASTER_ERROR_INTERRUPT)
>   			i9xx_error_irq_handler(dev_priv, eir, eir_stuck);
> 

Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Regards,

Tvrtko


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