[Intel-gfx] [PATCH v3] drm/i915: Rework GPU reset sequence to match driver load & thaw

Mika Kuoppala mika.kuoppala at linux.intel.com
Tue Aug 19 14:35:31 CEST 2014


"Mcaulay, Alistair" <alistair.mcaulay at intel.com> writes:

> Hi Mika,
>
> can you please review this patch, and verify it fixes the issues in your previous review.
>
> Thanks,
> Alistair.
>
>> -----Original Message-----
>> From: Mcaulay, Alistair
>> Sent: Friday, August 15, 2014 6:52 PM
>> To: intel-gfx at lists.freedesktop.org
>> Cc: Mcaulay, Alistair
>> Subject: [PATCH v3] drm/i915: Rework GPU reset sequence to match driver
>> load & thaw
>> 
>> From: "McAulay, Alistair" <alistair.mcaulay at intel.com>
>> 
>> This patch is to address Daniels concerns over different code during reset:
>> 
>> http://lists.freedesktop.org/archives/intel-gfx/2014-June/047758.html
>> 
>> "The reason for aiming as hard as possible to use the exact same code for
>> driver load, gpu reset and runtime pm/system resume is that we've simply
>> seen too many bugs due to slight variations and unintended omissions."
>> 
>> Tested using igt drv_hangman.
>> 
>> V2: Cleaner way of preventing check_wedge returning -EAGAIN
>> V3: Clean the last_context during reset, to ensure do_switch() does the
>> MI_SET_CONTEXT. As per review.
>> Signed-off-by: McAulay, Alistair <alistair.mcaulay at intel.com>
>> ---

Reviewed-by: Mika Kuoppala <mika.kuoppala at intel.com>

>>  drivers/gpu/drm/i915/i915_drv.c         |  6 +++
>>  drivers/gpu/drm/i915/i915_drv.h         |  3 ++
>>  drivers/gpu/drm/i915/i915_gem.c         |  4 +-
>>  drivers/gpu/drm/i915/i915_gem_context.c | 33 +++-------------
>>  drivers/gpu/drm/i915/i915_gem_gtt.c     | 67 +++++----------------------------
>>  drivers/gpu/drm/i915/i915_gem_gtt.h     |  3 +-
>>  6 files changed, 28 insertions(+), 88 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_drv.c
>> b/drivers/gpu/drm/i915/i915_drv.c index 5e4fefd..3bfafe6 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.c
>> +++ b/drivers/gpu/drm/i915/i915_drv.c
>> @@ -806,7 +806,13 @@ int i915_reset(struct drm_device *dev)
>>  			!dev_priv->ums.mm_suspended) {
>>  		dev_priv->ums.mm_suspended = 0;
>> 
>> +		/* Used to prevent gem_check_wedged returning -EAGAIN
>> during gpu reset */
>> +		dev_priv->gpu_error.reload_in_reset = true;
>> +
>>  		ret = i915_gem_init_hw(dev);
>> +
>> +		dev_priv->gpu_error.reload_in_reset = false;
>> +
>>  		mutex_unlock(&dev->struct_mutex);
>>  		if (ret) {
>>  			DRM_ERROR("Failed hw init on reset %d\n", ret); diff
>> --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 991b663..116daff 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -1217,6 +1217,9 @@ struct i915_gpu_error {
>> 
>>  	/* For missed irq/seqno simulation. */
>>  	unsigned int test_irq_rings;
>> +
>> +	/* Used to prevent gem_check_wedged returning -EAGAIN during
>> gpu reset   */
>> +	bool reload_in_reset;
>>  };
>> 
>>  enum modeset_restore {
>> diff --git a/drivers/gpu/drm/i915/i915_gem.c
>> b/drivers/gpu/drm/i915/i915_gem.c index ef047bc..e7396eb 100644
>> --- a/drivers/gpu/drm/i915/i915_gem.c
>> +++ b/drivers/gpu/drm/i915/i915_gem.c
>> @@ -1085,7 +1085,9 @@ i915_gem_check_wedge(struct i915_gpu_error
>> *error,
>>  		if (i915_terminally_wedged(error))
>>  			return -EIO;
>> 
>> -		return -EAGAIN;
>> +		/* Check if GPU Reset is in progress */
>> +		if (!error->reload_in_reset)
>> +			return -EAGAIN;
>>  	}
>> 
>>  	return 0;
>> diff --git a/drivers/gpu/drm/i915/i915_gem_context.c
>> b/drivers/gpu/drm/i915/i915_gem_context.c
>> index de72a28..9378ad8 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_context.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_context.c
>> @@ -377,34 +377,17 @@ void i915_gem_context_reset(struct drm_device
>> *dev)
>>  	struct drm_i915_private *dev_priv = dev->dev_private;
>>  	int i;
>> 
>> -	/* Prevent the hardware from restoring the last context (which
>> hung) on
>> -	 * the next switch */
>>  	for (i = 0; i < I915_NUM_RINGS; i++) {
>>  		struct intel_engine_cs *ring = &dev_priv->ring[i];
>> -		struct intel_context *dctx = ring->default_context;
>>  		struct intel_context *lctx = ring->last_context;
>> 
>> -		/* Do a fake switch to the default context */
>> -		if (lctx == dctx)
>> -			continue;
>> -
>> -		if (!lctx)
>> -			continue;
>> +		if (lctx) {
>> +			if (lctx->legacy_hw_ctx.rcs_state && i == RCS)
>> +				i915_gem_object_ggtt_unpin(lctx-
>> >legacy_hw_ctx.rcs_state);
>> 
>> -		if (dctx->legacy_hw_ctx.rcs_state && i == RCS) {
>> -			WARN_ON(i915_gem_obj_ggtt_pin(dctx-
>> >legacy_hw_ctx.rcs_state,
>> -
>> get_context_alignment(dev), 0));
>> -			/* Fake a finish/inactive */
>> -			dctx->legacy_hw_ctx.rcs_state->base.write_domain
>> = 0;
>> -			dctx->legacy_hw_ctx.rcs_state->active = 0;
>> +			i915_gem_context_unreference(lctx);
>> +			ring->last_context = NULL;
>>  		}
>> -
>> -		if (lctx->legacy_hw_ctx.rcs_state && i == RCS)
>> -			i915_gem_object_ggtt_unpin(lctx-
>> >legacy_hw_ctx.rcs_state);
>> -
>> -		i915_gem_context_unreference(lctx);
>> -		i915_gem_context_reference(dctx);
>> -		ring->last_context = dctx;
>>  	}
>>  }
>> 
>> @@ -498,10 +481,6 @@ int i915_gem_context_enable(struct
>> drm_i915_private *dev_priv)
>>  		ppgtt->enable(ppgtt);
>>  	}
>> 
>> -	/* FIXME: We should make this work, even in reset */
>> -	if (i915_reset_in_progress(&dev_priv->gpu_error))
>> -		return 0;
>> -
>>  	BUG_ON(!dev_priv->ring[RCS].default_context);
>> 
>>  	for_each_ring(ring, dev_priv, i) {
>> @@ -645,7 +624,7 @@ static int do_switch(struct intel_engine_cs *ring,
>>  	from = ring->last_context;
>> 
>>  	if (USES_FULL_PPGTT(ring->dev)) {
>> -		ret = ppgtt->switch_mm(ppgtt, ring, false);
>> +		ret = ppgtt->switch_mm(ppgtt, ring);
>>  		if (ret)
>>  			goto unpin_out;
>>  	}
>> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c
>> b/drivers/gpu/drm/i915/i915_gem_gtt.c
>> index 5188936..450c8a9 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_gtt.c
>> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
>> @@ -216,19 +216,12 @@ static gen6_gtt_pte_t
>> iris_pte_encode(dma_addr_t addr,
>> 
>>  /* Broadwell Page Directory Pointer Descriptors */  static int
>> gen8_write_pdp(struct intel_engine_cs *ring, unsigned entry,
>> -			   uint64_t val, bool synchronous)
>> +			   uint64_t val)
>>  {
>> -	struct drm_i915_private *dev_priv = ring->dev->dev_private;
>>  	int ret;
>> 
>>  	BUG_ON(entry >= 4);
>> 
>> -	if (synchronous) {
>> -		I915_WRITE(GEN8_RING_PDP_UDW(ring, entry), val >> 32);
>> -		I915_WRITE(GEN8_RING_PDP_LDW(ring, entry), (u32)val);
>> -		return 0;
>> -	}
>> -
>>  	ret = intel_ring_begin(ring, 6);
>>  	if (ret)
>>  		return ret;
>> @@ -245,8 +238,7 @@ static int gen8_write_pdp(struct intel_engine_cs
>> *ring, unsigned entry,  }
>> 
>>  static int gen8_mm_switch(struct i915_hw_ppgtt *ppgtt,
>> -			  struct intel_engine_cs *ring,
>> -			  bool synchronous)
>> +			  struct intel_engine_cs *ring)
>>  {
>>  	int i, ret;
>> 
>> @@ -255,7 +247,7 @@ static int gen8_mm_switch(struct i915_hw_ppgtt
>> *ppgtt,
>> 
>>  	for (i = used_pd - 1; i >= 0; i--) {
>>  		dma_addr_t addr = ppgtt->pd_dma_addr[i];
>> -		ret = gen8_write_pdp(ring, i, addr, synchronous);
>> +		ret = gen8_write_pdp(ring, i, addr);
>>  		if (ret)
>>  			return ret;
>>  	}
>> @@ -724,29 +716,10 @@ static uint32_t get_pd_offset(struct i915_hw_ppgtt
>> *ppgtt)  }
>> 
>>  static int hsw_mm_switch(struct i915_hw_ppgtt *ppgtt,
>> -			 struct intel_engine_cs *ring,
>> -			 bool synchronous)
>> +			 struct intel_engine_cs *ring)
>>  {
>> -	struct drm_device *dev = ppgtt->base.dev;
>> -	struct drm_i915_private *dev_priv = dev->dev_private;
>>  	int ret;
>> 
>> -	/* If we're in reset, we can assume the GPU is sufficiently idle to
>> -	 * manually frob these bits. Ideally we could use the ring functions,
>> -	 * except our error handling makes it quite difficult (can't use
>> -	 * intel_ring_begin, ring->flush, or intel_ring_advance)
>> -	 *
>> -	 * FIXME: We should try not to special case reset
>> -	 */
>> -	if (synchronous ||
>> -	    i915_reset_in_progress(&dev_priv->gpu_error)) {
>> -		WARN_ON(ppgtt != dev_priv->mm.aliasing_ppgtt);
>> -		I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
>> -		I915_WRITE(RING_PP_DIR_BASE(ring),
>> get_pd_offset(ppgtt));
>> -		POSTING_READ(RING_PP_DIR_BASE(ring));
>> -		return 0;
>> -	}
>> -
>>  	/* NB: TLBs must be flushed and invalidated before a switch */
>>  	ret = ring->flush(ring, I915_GEM_GPU_DOMAINS,
>> I915_GEM_GPU_DOMAINS);
>>  	if (ret)
>> @@ -768,29 +741,10 @@ static int hsw_mm_switch(struct i915_hw_ppgtt
>> *ppgtt,  }
>> 
>>  static int gen7_mm_switch(struct i915_hw_ppgtt *ppgtt,
>> -			  struct intel_engine_cs *ring,
>> -			  bool synchronous)
>> +			  struct intel_engine_cs *ring)
>>  {
>> -	struct drm_device *dev = ppgtt->base.dev;
>> -	struct drm_i915_private *dev_priv = dev->dev_private;
>>  	int ret;
>> 
>> -	/* If we're in reset, we can assume the GPU is sufficiently idle to
>> -	 * manually frob these bits. Ideally we could use the ring functions,
>> -	 * except our error handling makes it quite difficult (can't use
>> -	 * intel_ring_begin, ring->flush, or intel_ring_advance)
>> -	 *
>> -	 * FIXME: We should try not to special case reset
>> -	 */
>> -	if (synchronous ||
>> -	    i915_reset_in_progress(&dev_priv->gpu_error)) {
>> -		WARN_ON(ppgtt != dev_priv->mm.aliasing_ppgtt);
>> -		I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
>> -		I915_WRITE(RING_PP_DIR_BASE(ring),
>> get_pd_offset(ppgtt));
>> -		POSTING_READ(RING_PP_DIR_BASE(ring));
>> -		return 0;
>> -	}
>> -
>>  	/* NB: TLBs must be flushed and invalidated before a switch */
>>  	ret = ring->flush(ring, I915_GEM_GPU_DOMAINS,
>> I915_GEM_GPU_DOMAINS);
>>  	if (ret)
>> @@ -819,14 +773,11 @@ static int gen7_mm_switch(struct i915_hw_ppgtt
>> *ppgtt,  }
>> 
>>  static int gen6_mm_switch(struct i915_hw_ppgtt *ppgtt,
>> -			  struct intel_engine_cs *ring,
>> -			  bool synchronous)
>> +			  struct intel_engine_cs *ring)
>>  {
>>  	struct drm_device *dev = ppgtt->base.dev;
>>  	struct drm_i915_private *dev_priv = dev->dev_private;
>> 
>> -	if (!synchronous)
>> -		return 0;
>> 
>>  	I915_WRITE(RING_PP_DIR_DCLV(ring), PP_DIR_DCLV_2G);
>>  	I915_WRITE(RING_PP_DIR_BASE(ring), get_pd_offset(ppgtt)); @@ -
>> 852,7 +803,7 @@ static int gen8_ppgtt_enable(struct i915_hw_ppgtt *ppgtt)
>>  		if (USES_FULL_PPGTT(dev))
>>  			continue;
>> 
>> -		ret = ppgtt->switch_mm(ppgtt, ring, true);
>> +		ret = ppgtt->switch_mm(ppgtt, ring);
>>  		if (ret)
>>  			goto err_out;
>>  	}
>> @@ -897,7 +848,7 @@ static int gen7_ppgtt_enable(struct i915_hw_ppgtt
>> *ppgtt)
>>  		if (USES_FULL_PPGTT(dev))
>>  			continue;
>> 
>> -		ret = ppgtt->switch_mm(ppgtt, ring, true);
>> +		ret = ppgtt->switch_mm(ppgtt, ring);
>>  		if (ret)
>>  			return ret;
>>  	}
>> @@ -926,7 +877,7 @@ static int gen6_ppgtt_enable(struct i915_hw_ppgtt
>> *ppgtt)
>>  	I915_WRITE(GFX_MODE,
>> _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
>> 
>>  	for_each_ring(ring, dev_priv, i) {
>> -		int ret = ppgtt->switch_mm(ppgtt, ring, true);
>> +		int ret = ppgtt->switch_mm(ppgtt, ring);
>>  		if (ret)
>>  			return ret;
>>  	}
>> diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.h
>> b/drivers/gpu/drm/i915/i915_gem_gtt.h
>> index 8d6f7c1..bf1e4fc 100644
>> --- a/drivers/gpu/drm/i915/i915_gem_gtt.h
>> +++ b/drivers/gpu/drm/i915/i915_gem_gtt.h
>> @@ -262,8 +262,7 @@ struct i915_hw_ppgtt {
>> 
>>  	int (*enable)(struct i915_hw_ppgtt *ppgtt);
>>  	int (*switch_mm)(struct i915_hw_ppgtt *ppgtt,
>> -			 struct intel_engine_cs *ring,
>> -			 bool synchronous);
>> +			 struct intel_engine_cs *ring);
>>  	void (*debug_dump)(struct i915_hw_ppgtt *ppgtt, struct seq_file
>> *m);  };
>> 
>> --
>> 2.0.4



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