[PATCH 2/2] drm/amdgpu: add the interface of waiting multiple fences (v4)

Christian König deathsimple at vodafone.de
Mon Nov 7 08:04:31 UTC 2016


Am 07.11.2016 um 02:10 schrieb Gustavo Padovan:
> Hi Alex,
>
> 2016-11-04 Alex Deucher <alexdeucher at gmail.com>:
>
>> From: Junwei Zhang <Jerry.Zhang at amd.com>
>>
>> v2: agd: rebase and squash in all the previous optimizations and
>> changes so everything compiles.
>> v3: squash in Slava's 32bit build fix
>> v4: rebase on drm-next (fence -> dma_fence),
>>      squash in Monk's ioctl update patch
>>
>> Signed-off-by: Junwei Zhang <Jerry.Zhang at amd.com>
>> Reviewed-by: Monk Liu <monk.liu at amd.com>
>> Reviewed-by: Jammy Zhou <Jammy.Zhou at amd.com>
>> Signed-off-by: Alex Deucher <alexander.deucher at amd.com>
>> ---
>>   drivers/gpu/drm/amd/amdgpu/amdgpu.h     |   2 +
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c  | 173 ++++++++++++++++++++++++++++++++
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_kms.c |   1 +
>>   drivers/gpu/drm/amd/amdgpu/amdgpu_sa.c  |   2 +-
>>   include/uapi/drm/amdgpu_drm.h           |  28 ++++++
>>   5 files changed, 205 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu.h b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> index dc98ceb..7a94a3c 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu.h
>> @@ -1212,6 +1212,8 @@ int amdgpu_gem_op_ioctl(struct drm_device *dev, void *data,
>>   			struct drm_file *filp);
>>   int amdgpu_cs_ioctl(struct drm_device *dev, void *data, struct drm_file *filp);
>>   int amdgpu_cs_wait_ioctl(struct drm_device *dev, void *data, struct drm_file *filp);
>> +int amdgpu_cs_wait_fences_ioctl(struct drm_device *dev, void *data,
>> +				struct drm_file *filp);
>>   
>>   int amdgpu_gem_metadata_ioctl(struct drm_device *dev, void *data,
>>   				struct drm_file *filp);
>> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> index 2728805..2004836 100644
>> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_cs.c
>> @@ -1130,6 +1130,179 @@ int amdgpu_cs_wait_ioctl(struct drm_device *dev, void *data,
>>   }
>>   
>>   /**
>> + * amdgpu_cs_get_fence - helper to get fence from drm_amdgpu_fence
>> + *
>> + * @adev: amdgpu device
>> + * @filp: file private
>> + * @user: drm_amdgpu_fence copied from user space
>> + */
>> +static struct dma_fence *amdgpu_cs_get_fence(struct amdgpu_device *adev,
>> +					     struct drm_file *filp,
>> +					     struct drm_amdgpu_fence *user)
>> +{
>> +	struct amdgpu_ring *ring;
>> +	struct amdgpu_ctx *ctx;
>> +	struct dma_fence *fence;
>> +	int r;
>> +
>> +	r = amdgpu_cs_get_ring(adev, user->ip_type, user->ip_instance,
>> +			       user->ring, &ring);
>> +	if (r)
>> +		return ERR_PTR(r);
>> +
>> +	ctx = amdgpu_ctx_get(filp->driver_priv, user->ctx_id);
>> +	if (ctx == NULL)
>> +		return ERR_PTR(-EINVAL);
>> +
>> +	fence = amdgpu_ctx_get_fence(ctx, ring, user->seq_no);
>> +	amdgpu_ctx_put(ctx);
>> +
>> +	return fence;
>> +}
>> +
>> +/**
>> + * amdgpu_cs_wait_all_fence - wait on all fences to signal
>> + *
>> + * @adev: amdgpu device
>> + * @filp: file private
>> + * @wait: wait parameters
>> + * @fences: array of drm_amdgpu_fence
>> + */
>> +static int amdgpu_cs_wait_all_fences(struct amdgpu_device *adev,
>> +				     struct drm_file *filp,
>> +				     union drm_amdgpu_wait_fences *wait,
>> +				     struct drm_amdgpu_fence *fences)
>> +{
>> +	uint32_t fence_count = wait->in.fence_count;
>> +	unsigned i;
>> +	long r = 1;
>> +
>> +	for (i = 0; i < fence_count; i++) {
>> +		struct dma_fence *fence;
>> +		unsigned long timeout = amdgpu_gem_timeout(wait->in.timeout_ns);
>> +
>> +		fence = amdgpu_cs_get_fence(adev, filp, &fences[i]);
>> +		if (IS_ERR(fence))
>> +			return PTR_ERR(fence);
>> +		else if (!fence)
>> +			continue;
>> +
>> +		r = dma_fence_wait_timeout(fence, true, timeout);
>> +		if (r < 0)
>> +			return r;
>> +
>> +		if (r == 0)
>> +			break;
>> +	}
>> +
>> +	memset(wait, 0, sizeof(*wait));
>> +	wait->out.status = (r > 0);
>> +
>> +	return 0;
>> +}
>> +
>> +/**
>> + * amdgpu_cs_wait_any_fence - wait on any fence to signal
>> + *
>> + * @adev: amdgpu device
>> + * @filp: file private
>> + * @wait: wait parameters
>> + * @fences: array of drm_amdgpu_fence
>> + */
>> +static int amdgpu_cs_wait_any_fence(struct amdgpu_device *adev,
>> +				    struct drm_file *filp,
>> +				    union drm_amdgpu_wait_fences *wait,
>> +				    struct drm_amdgpu_fence *fences)
>> +{
>> +	unsigned long timeout = amdgpu_gem_timeout(wait->in.timeout_ns);
>> +	uint32_t fence_count = wait->in.fence_count;
>> +	uint32_t first = ~0;
>> +	struct dma_fence **array;
>> +	unsigned i;
>> +	long r;
>> +
>> +	/* Prepare the fence array */
>> +	array = (struct dma_fence **)kcalloc(fence_count, sizeof(struct dma_fence *),
>> +			GFP_KERNEL);
>> +	if (array == NULL)
>> +		return -ENOMEM;
>> +
>> +	for (i = 0; i < fence_count; i++) {
>> +		struct dma_fence *fence;
>> +
>> +		fence = amdgpu_cs_get_fence(adev, filp, &fences[i]);
>> +		if (IS_ERR(fence)) {
>> +			r = PTR_ERR(fence);
>> +			goto err_free_fence_array;
>> +		} else if (fence) {
>> +			array[i] = fence;
>> +		} else { /* NULL, the fence has been already signaled */
>> +			r = 1;
>> +			goto out;
>> +		}
>> +	}
>> +
>> +	r = dma_fence_wait_any_timeout(array, fence_count, true, timeout, &first);
>> +	if (r < 0)
>> +		goto err_free_fence_array;
>> +
>> +out:
>> +	memset(wait, 0, sizeof(*wait));
>> +	wait->out.status = (r > 0);
>> +	wait->out.first_signaled = first;
>> +	/* set return value 0 to indicate success */
>> +	r = 0;
>> +
>> +err_free_fence_array:
>> +	for (i = 0; i < fence_count; i++)
>> +		dma_fence_put(array[i]);
>> +	kfree(array);
>> +
>> +	return r;
>> +}
>> +
>> +/**
>> + * amdgpu_cs_wait_fences_ioctl - wait for multiple command submissions to finish
>> + *
>> + * @dev: drm device
>> + * @data: data from userspace
>> + * @filp: file private
>> + */
>> +int amdgpu_cs_wait_fences_ioctl(struct drm_device *dev, void *data,
>> +				struct drm_file *filp)
>> +{
>> +	struct amdgpu_device *adev = dev->dev_private;
>> +	union drm_amdgpu_wait_fences *wait = data;
>> +	uint32_t fence_count = wait->in.fence_count;
>> +	struct drm_amdgpu_fence *fences_user;
>> +	struct drm_amdgpu_fence *fences;
>> +	int r;
>> +
>> +	/* Get the fences from userspace */
>> +	fences = kmalloc_array(fence_count, sizeof(struct drm_amdgpu_fence),
>> +			GFP_KERNEL);
>> +	if (fences == NULL)
>> +		return -ENOMEM;
>> +
>> +	fences_user = (void __user *)(unsigned long)(wait->in.fences);
>> +	if (copy_from_user(fences, fences_user,
>> +		sizeof(struct drm_amdgpu_fence) * fence_count)) {
>> +		r = -EFAULT;
>> +		goto err_free_fences;
>> +	}
>> +
>> +	if (wait->in.wait_all)
>> +		r = amdgpu_cs_wait_all_fences(adev, filp, wait, fences);
>> +	else
>> +		r = amdgpu_cs_wait_any_fence(adev, filp, wait, fences);
> I wonder if it wouldn't be better if we use fence_array here and
> register callbacks to get notfied of the first signaled fence the "any" case.
> It seems to me that we could simplify this code by using a fence_array.

I had this code in mind as well when working on the fence_array.

But this code actually precedes the fence_array implementation, so I 
would like to push it upstream unchanged and then clean it up to use the 
fence array.

That would make our backporting efforts a bit easier and shouldn't 
affect upstream to much in any way.

Regards,
Christian.

>
> Gustavo
>
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