[Intel-gfx] [PATCH 2/5] drm/i915/icl: Use hw engine class, instance to find irq handler

Daniele Ceraolo Spurio daniele.ceraolospurio at intel.com
Thu Apr 5 17:10:40 UTC 2018



On 05/04/18 07:00, Mika Kuoppala wrote:
> Interrupt identity register we already read from hardware
> contains engine class and instance fields. Leverage
> these fields to find correct engine to handle the interrupt.
> 
> v3: rebase on top of rps intr
>      use correct class / instance limits (Michel)
> v4: split engine/other handling
> 
> Suggested-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> Cc: Michel Thierry <michel.thierry at intel.com>
> Signed-off-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> ---
>   drivers/gpu/drm/i915/i915_irq.c | 102 ++++++++++++++++++++++------------------
>   drivers/gpu/drm/i915/i915_reg.h |   4 +-
>   2 files changed, 59 insertions(+), 47 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
> index 27aee25429b7..f984bf12a0b6 100644
> --- a/drivers/gpu/drm/i915/i915_irq.c
> +++ b/drivers/gpu/drm/i915/i915_irq.c
> @@ -2732,47 +2732,9 @@ static void __fini_wedge(struct wedge_me *w)
>   	     (W)->i915;							\
>   	     __fini_wedge((W)))
>   
> -static void
> -gen11_gt_engine_irq_handler(struct drm_i915_private * const i915,
> -			    const unsigned int bank,
> -			    const unsigned int engine_n,
> -			    const u16 iir)
> -{
> -	struct intel_engine_cs ** const engine = i915->engine;
> -
> -	switch (bank) {
> -	case 0:
> -		switch (engine_n) {
> -
> -		case GEN11_RCS0:
> -			return gen8_cs_irq_handler(engine[RCS], iir);
> -
> -		case GEN11_BCS:
> -			return gen8_cs_irq_handler(engine[BCS], iir);
> -		}
> -	case 1:
> -		switch (engine_n) {
> -
> -		case GEN11_VCS(0):
> -			return gen8_cs_irq_handler(engine[_VCS(0)], iir);
> -		case GEN11_VCS(1):
> -			return gen8_cs_irq_handler(engine[_VCS(1)], iir);
> -		case GEN11_VCS(2):
> -			return gen8_cs_irq_handler(engine[_VCS(2)], iir);
> -		case GEN11_VCS(3):
> -			return gen8_cs_irq_handler(engine[_VCS(3)], iir);
> -
> -		case GEN11_VECS(0):
> -			return gen8_cs_irq_handler(engine[_VECS(0)], iir);
> -		case GEN11_VECS(1):
> -			return gen8_cs_irq_handler(engine[_VECS(1)], iir);
> -		}
> -	}
> -}
> -
>   static u32
> -gen11_gt_engine_intr(struct drm_i915_private * const i915,
> -		     const unsigned int bank, const unsigned int bit)
> +gen11_gt_engine_identity(struct drm_i915_private * const i915,
> +			 const unsigned int bank, const unsigned int bit)
>   {
>   	void __iomem * const regs = i915->regs;
>   	u32 timeout_ts;
> @@ -2799,7 +2761,57 @@ gen11_gt_engine_intr(struct drm_i915_private * const i915,
>   	raw_reg_write(regs, GEN11_INTR_IDENTITY_REG(bank),
>   		      GEN11_INTR_DATA_VALID);
>   
> -	return ident & GEN11_INTR_ENGINE_MASK;
> +	return ident;
> +}
> +
> +static void
> +gen11_other_irq_handler(struct drm_i915_private * const i915,
> +			const u8 instance, const u16 iir)
> +{
> +	WARN_ONCE(1, "unhandled other interrupt instance=0x%x, iir=0x%x\n",
> +		  instance, iir);
> +}
> +
> +static void
> +gen11_engine_irq_handler(struct drm_i915_private * const i915,
> +			 const u8 class, const u8 instance, const u16 iir)
> +{
> +	struct intel_engine_cs *engine;
> +
> +	if (instance <= MAX_ENGINE_INSTANCE)
> +		engine = i915->engine_class[class][instance];
> +	else
> +		engine = NULL;
> +

bikeshed: if we initialize the engine pointer to null above we can skip 
the else case here.

> +	if (likely(engine))
> +		return gen8_cs_irq_handler(engine, iir);
> +
> +	WARN_ONCE(1, "unhandled engine interrupt class=0x%x, instance=0x%x\n",
> +		  class, instance);
> +}
> +
> +static void
> +gen11_gt_identity_handler(struct drm_i915_private * const i915,
> +			  const u32 identity)
> +{
> +	const u8 class = GEN11_INTR_ENGINE_CLASS(identity);
> +	const u8 instance = GEN11_INTR_ENGINE_INSTANCE(identity);
> +	const u16 intr = GEN11_INTR_ENGINE_INTR(identity);
> +
> +	if (unlikely(!intr)) {
> +		DRM_ERROR("class=0x%x, instance=0x%x, intr expected!\n",
> +			  class, instance);

This is not an error, it is possible to have an empty iir with double 
buffering. With the log removed:

Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>

Thanks,
Daniele

> +		return;
> +	}
> +
> +	if (class <= COPY_ENGINE_CLASS)
> +		return gen11_engine_irq_handler(i915, class, instance, intr);
> +
> +	if (class == OTHER_CLASS)
> +		return gen11_other_irq_handler(i915, instance, intr);
> +
> +	WARN_ONCE(1, "unknown interrupt class=0x%x, instance=0x%x, intr=0x%x\n",
> +		  class, instance, intr);
>   }
>   
>   static void
> @@ -2824,12 +2836,10 @@ gen11_gt_irq_handler(struct drm_i915_private * const i915,
>   		}
>   
>   		for_each_set_bit(bit, &intr_dw, 32) {
> -			const u16 iir = gen11_gt_engine_intr(i915, bank, bit);
> -
> -			if (unlikely(!iir))
> -				continue;
> +			const u32 ident = gen11_gt_engine_identity(i915,
> +								   bank, bit);
>   
> -			gen11_gt_engine_irq_handler(i915, bank, bit, iir);
> +			gen11_gt_identity_handler(i915, ident);
>   		}
>   
>   		/* Clear must be after shared has been served for engine */
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index b2a2d8fbbc68..d4b5fba7a2dc 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -6998,7 +6998,9 @@ enum {
>   #define GEN11_INTR_IDENTITY_REG0	_MMIO(0x190060)
>   #define GEN11_INTR_IDENTITY_REG1	_MMIO(0x190064)
>   #define  GEN11_INTR_DATA_VALID		(1 << 31)
> -#define  GEN11_INTR_ENGINE_MASK		(0xffff)
> +#define  GEN11_INTR_ENGINE_CLASS(x)	(((x) & GENMASK(18, 16)) >> 16)
> +#define  GEN11_INTR_ENGINE_INSTANCE(x)	(((x) & GENMASK(25, 20)) >> 20)
> +#define  GEN11_INTR_ENGINE_INTR(x)	((x) & 0xffff)
>   
>   #define GEN11_INTR_IDENTITY_REG(x)	_MMIO(0x190060 + (x * 4))
>   
> 


More information about the Intel-gfx mailing list