Commit eebab60f authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Don't mix srcu tag and negative error codes 



While srcu may use an integer tag, it does not exclude potential error
codes and so may overlap with our own use of -EINTR. Use a separate
outparam to store the tag, and report the error code separately.

Fixes: 2caffbf1 ("drm/i915: Revoke mmaps and prevent access to fence registers across reset")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Reviewed-by: default avatarMika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190912160834.30601-1-chris@chris-wilson.co.uk
parent e91c8a29

drivers/gpu/drm/i915/gem/i915_gem_mman.c

+2 −4
Original line number Diff line number Diff line
@@ -245,11 +245,9 @@ vm_fault_t i915_gem_fault(struct vm_fault *vmf) 


	wakeref = intel_runtime_pm_get(rpm);



	srcu = intel_gt_reset_trylock(ggtt->vm.gt);

	if (srcu < 0) {

		ret = srcu;

	ret = intel_gt_reset_trylock(ggtt->vm.gt, &srcu);

	if (ret)

		goto err_rpm;

	}



	ret = i915_mutex_lock_interruptible(dev);

	if (ret)

drivers/gpu/drm/i915/gt/intel_reset.c

+3 −5
Original line number Diff line number Diff line
@@ -1214,10 +1214,8 @@ out: 
	intel_runtime_pm_put(&gt->i915->runtime_pm, wakeref);

}



int intel_gt_reset_trylock(struct intel_gt *gt)

int intel_gt_reset_trylock(struct intel_gt *gt, int *srcu)

{

	int srcu;



	might_lock(&gt->reset.backoff_srcu);

	might_sleep();
@@ -1232,10 +1230,10 @@ int intel_gt_reset_trylock(struct intel_gt *gt) 


		rcu_read_lock();

	}

	srcu = srcu_read_lock(&gt->reset.backoff_srcu);

	*srcu = srcu_read_lock(&gt->reset.backoff_srcu);

	rcu_read_unlock();



	return srcu;

	return 0;

}



void intel_gt_reset_unlock(struct intel_gt *gt, int tag)

drivers/gpu/drm/i915/gt/intel_reset.h

+1 −1
Original line number Diff line number Diff line
@@ -38,7 +38,7 @@ int intel_engine_reset(struct intel_engine_cs *engine, 


void __i915_request_reset(struct i915_request *rq, bool guilty);



int __must_check intel_gt_reset_trylock(struct intel_gt *gt);

int __must_check intel_gt_reset_trylock(struct intel_gt *gt, int *srcu);

void intel_gt_reset_unlock(struct intel_gt *gt, int tag);



void intel_gt_set_wedged(struct intel_gt *gt);

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