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

Michel Thierry michel.thierry at intel.com
Thu Apr 5 18:17:17 UTC 2018


On 4/5/2018 10:10 AM, Daniele Ceraolo Spurio wrote:
> 
> 
> 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:
> 

I agree with Daniele, unlikely but possible.

> Reviewed-by: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
> 
So with that, also

Reviewed-by: Michel Thierry <michel.thierry 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