drm/v3d: clean caches at the end of render jobs on request from user space

Submitted by Iago Toral on Sept. 12, 2019, 8:35 a.m.

Details

Message ID 20190912083516.13797-1-itoral@igalia.com
State New
Headers show
Series "drm/v3d: clean caches at the end of render jobs on request from user space" ( rev: 1 ) in DRI devel

Not browsing as part of any series.

Commit Message

Iago Toral Sept. 12, 2019, 8:35 a.m.
Extends the user space ioctl for CL submissions so it can include a request
to flush the cache once the CL execution has completed. Fixes memory
write violation messages reported by the kernel in workloads involving
shader memory writes (SSBOs, shader images, scratch, etc) which sometimes
also lead to GPU resets during Piglit and CTS workloads.

Signed-off-by: Iago Toral Quiroga <itoral@igalia.com>
---
 drivers/gpu/drm/v3d/v3d_gem.c | 51 +++++++++++++++++++++++++++++------
 include/uapi/drm/v3d_drm.h    |  7 ++---
 2 files changed, 47 insertions(+), 11 deletions(-)

Patch hide | download patch | download mbox

diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c
index 5d80507b539b..530fe9d9d5bd 100644
--- a/drivers/gpu/drm/v3d/v3d_gem.c
+++ b/drivers/gpu/drm/v3d/v3d_gem.c
@@ -530,13 +530,16 @@  v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 	struct drm_v3d_submit_cl *args = data;
 	struct v3d_bin_job *bin = NULL;
 	struct v3d_render_job *render;
+	struct v3d_job *clean_job = NULL;
+	struct v3d_job *last_job;
 	struct ww_acquire_ctx acquire_ctx;
 	int ret = 0;
 
 	trace_v3d_submit_cl_ioctl(&v3d->drm, args->rcl_start, args->rcl_end);
 
-	if (args->pad != 0) {
-		DRM_INFO("pad must be zero: %d\n", args->pad);
+	if (args->flags != 0 &&
+	    args->flags != DRM_V3D_SUBMIT_CL_FLUSH_CACHE_FLAG) {
+		DRM_INFO("invalid flags: %d\n", args->flags);
 		return -EINVAL;
 	}
 
@@ -575,12 +578,28 @@  v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 		bin->render = render;
 	}
 
-	ret = v3d_lookup_bos(dev, file_priv, &render->base,
+	if (args->flags & DRM_V3D_SUBMIT_CL_FLUSH_CACHE_FLAG) {
+		clean_job = kcalloc(1, sizeof(*clean_job), GFP_KERNEL);
+		if (!clean_job) {
+			ret = -ENOMEM;
+			goto fail;
+		}
+
+		ret = v3d_job_init(v3d, file_priv, clean_job, v3d_job_free, 0);
+		if (ret)
+			goto fail;
+
+		last_job = clean_job;
+	} else {
+		last_job = &render->base;
+	}
+
+	ret = v3d_lookup_bos(dev, file_priv, last_job,
 			     args->bo_handles, args->bo_handle_count);
 	if (ret)
 		goto fail;
 
-	ret = v3d_lock_bo_reservations(&render->base, &acquire_ctx);
+	ret = v3d_lock_bo_reservations(last_job, &acquire_ctx);
 	if (ret)
 		goto fail;
 
@@ -599,28 +618,44 @@  v3d_submit_cl_ioctl(struct drm_device *dev, void *data,
 	ret = v3d_push_job(v3d_priv, &render->base, V3D_RENDER);
 	if (ret)
 		goto fail_unreserve;
+
+	if (clean_job) {
+		struct dma_fence *render_fence =
+			dma_fence_get(render->base.done_fence);
+		ret = drm_gem_fence_array_add(&clean_job->deps, render_fence);
+		if (ret)
+			goto fail_unreserve;
+		ret = v3d_push_job(v3d_priv, clean_job, V3D_CACHE_CLEAN);
+		if (ret)
+			goto fail_unreserve;
+	}
+
 	mutex_unlock(&v3d->sched_lock);
 
 	v3d_attach_fences_and_unlock_reservation(file_priv,
-						 &render->base,
+						 last_job,
 						 &acquire_ctx,
 						 args->out_sync,
-						 render->base.done_fence);
+						 last_job->done_fence);
 
 	if (bin)
 		v3d_job_put(&bin->base);
 	v3d_job_put(&render->base);
+	if (clean_job)
+		v3d_job_put(clean_job);
 
 	return 0;
 
 fail_unreserve:
 	mutex_unlock(&v3d->sched_lock);
-	drm_gem_unlock_reservations(render->base.bo,
-				    render->base.bo_count, &acquire_ctx);
+	drm_gem_unlock_reservations(last_job->bo,
+				    last_job->bo_count, &acquire_ctx);
 fail:
 	if (bin)
 		v3d_job_put(&bin->base);
 	v3d_job_put(&render->base);
+	if (clean_job)
+		v3d_job_put(clean_job);
 
 	return ret;
 }
diff --git a/include/uapi/drm/v3d_drm.h b/include/uapi/drm/v3d_drm.h
index 58fbe48c91e9..58d2040ea48c 100644
--- a/include/uapi/drm/v3d_drm.h
+++ b/include/uapi/drm/v3d_drm.h
@@ -48,6 +48,8 @@  extern "C" {
 #define DRM_IOCTL_V3D_SUBMIT_TFU          DRM_IOW(DRM_COMMAND_BASE + DRM_V3D_SUBMIT_TFU, struct drm_v3d_submit_tfu)
 #define DRM_IOCTL_V3D_SUBMIT_CSD          DRM_IOW(DRM_COMMAND_BASE + DRM_V3D_SUBMIT_CSD, struct drm_v3d_submit_csd)
 
+#define DRM_V3D_SUBMIT_CL_FLUSH_CACHE_FLAG        0x01
+
 /**
  * struct drm_v3d_submit_cl - ioctl argument for submitting commands to the 3D
  * engine.
@@ -61,7 +63,7 @@  extern "C" {
  * flushed by the time the render done IRQ happens, which is the
  * trigger for out_sync.  Any dirtying of cachelines by the job (only
  * possible using TMU writes) must be flushed by the caller using the
- * CL's cache flush commands.
+ * DRM_V3D_SUBMIT_CL_FLUSH_CACHE_FLAG flag.
  */
 struct drm_v3d_submit_cl {
 	/* Pointer to the binner command list.
@@ -124,8 +126,7 @@  struct drm_v3d_submit_cl {
 	/* Number of BO handles passed in (size is that times 4). */
 	__u32 bo_handle_count;
 
-	/* Pad, must be zero-filled. */
-	__u32 pad;
+	__u32 flags;
 };
 
 /**

Comments


On Thu, 2019-09-12 at 10:25 -0700, Eric Anholt wrote:
> Iago Toral Quiroga <itoral@igalia.com> writes:
> 
> > Extends the user space ioctl for CL submissions so it can include a
> > request
> > to flush the cache once the CL execution has completed. Fixes
> > memory
> > write violation messages reported by the kernel in workloads
> > involving
> > shader memory writes (SSBOs, shader images, scratch, etc) which
> > sometimes
> > also lead to GPU resets during Piglit and CTS workloads.
> 
> Some context for any other reviewers: This patch is the interface
> change
> necessary to expose GLES 3.1 on V3D.  It turns out the HW packets for
> flushing the caches were broken in multiple ways.
> 
> > Signed-off-by: Iago Toral Quiroga <itoral@igalia.com>
> > ---
> >  drivers/gpu/drm/v3d/v3d_gem.c | 51 +++++++++++++++++++++++++++++
> > ------
> >  include/uapi/drm/v3d_drm.h    |  7 ++---
> >  2 files changed, 47 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/v3d/v3d_gem.c
> > b/drivers/gpu/drm/v3d/v3d_gem.c
> > index 5d80507b539b..530fe9d9d5bd 100644
> > --- a/drivers/gpu/drm/v3d/v3d_gem.c
> > +++ b/drivers/gpu/drm/v3d/v3d_gem.c
> > @@ -530,13 +530,16 @@ v3d_submit_cl_ioctl(struct drm_device *dev,
> > void *data,
> >  	struct drm_v3d_submit_cl *args = data;
> >  	struct v3d_bin_job *bin = NULL;
> >  	struct v3d_render_job *render;
> > +	struct v3d_job *clean_job = NULL;
> > +	struct v3d_job *last_job;
> >  	struct ww_acquire_ctx acquire_ctx;
> >  	int ret = 0;
> >  
> >  	trace_v3d_submit_cl_ioctl(&v3d->drm, args->rcl_start, args-
> > >rcl_end);
> >  
> > -	if (args->pad != 0) {
> > -		DRM_INFO("pad must be zero: %d\n", args->pad);
> > +	if (args->flags != 0 &&
> > +	    args->flags != DRM_V3D_SUBMIT_CL_FLUSH_CACHE_FLAG) {
> > +		DRM_INFO("invalid flags: %d\n", args->flags);
> >  		return -EINVAL;
> >  	}
> >  
> > @@ -575,12 +578,28 @@ v3d_submit_cl_ioctl(struct drm_device *dev,
> > void *data,
> >  		bin->render = render;
> >  	}
> >  
> > -	ret = v3d_lookup_bos(dev, file_priv, &render->base,
> > +	if (args->flags & DRM_V3D_SUBMIT_CL_FLUSH_CACHE_FLAG) {
> > +		clean_job = kcalloc(1, sizeof(*clean_job), GFP_KERNEL);
> > +		if (!clean_job) {
> > +			ret = -ENOMEM;
> > +			goto fail;
> > +		}
> > +
> > +		ret = v3d_job_init(v3d, file_priv, clean_job,
> > v3d_job_free, 0);
> > +		if (ret)
> > +			goto fail;
> 
> Only issue I see: If v3d_job_init() fails, we need to not
> v3d_job_put()
> it.  I'm fine with either kfree() it and NULL the ptr before jumping
> to
> fail, or open code the bin/render puts.

It seems we also call v3d_job_put() for the bin job when v3d_job_init()
fails, which also returns immediately in that case instead of jumping
to fail to v3d_job_put the render job, so I guess we need the same
treatment there. Shall I fix that in this patch too or would you rather
see a different patch sent separately for that?

> With that,
> 
> Reviewed-by: Eric Anholt <eric@anholt.net>
> 
> > +
> > +		last_job = clean_job;
> > +	} else {
> > +		last_job = &render->base;
> > +	}
> > +
> > +	ret = v3d_lookup_bos(dev, file_priv, last_job,
> >  			     args->bo_handles, args->bo_handle_count);
> >  	if (ret)
> >  		goto fail;
> >  
> > -	ret = v3d_lock_bo_reservations(&render->base, &acquire_ctx);
> > +	ret = v3d_lock_bo_reservations(last_job, &acquire_ctx);
> >  	if (ret)
> >  		goto fail;
> >  
> > @@ -599,28 +618,44 @@ v3d_submit_cl_ioctl(struct drm_device *dev,
> > void *data,
> >  	ret = v3d_push_job(v3d_priv, &render->base, V3D_RENDER);
> >  	if (ret)
> >  		goto fail_unreserve;
> > +
> > +	if (clean_job) {
> > +		struct dma_fence *render_fence =
> > +			dma_fence_get(render->base.done_fence);
> > +		ret = drm_gem_fence_array_add(&clean_job->deps,
> > render_fence);
> > +		if (ret)
> > +			goto fail_unreserve;
> > +		ret = v3d_push_job(v3d_priv, clean_job,
> > V3D_CACHE_CLEAN);
> > +		if (ret)
> > +			goto fail_unreserve;
> > +	}
> > +
> >  	mutex_unlock(&v3d->sched_lock);
> >  
> >  	v3d_attach_fences_and_unlock_reservation(file_priv,
> > -						 &render->base,
> > +						 last_job,
> >  						 &acquire_ctx,
> >  						 args->out_sync,
> > -						 render-
> > >base.done_fence);
> > +						 last_job->done_fence);
> >  
> >  	if (bin)
> >  		v3d_job_put(&bin->base);
> >  	v3d_job_put(&render->base);
> > +	if (clean_job)
> > +		v3d_job_put(clean_job);
> >  
> >  	return 0;
> >  
> >  fail_unreserve:
> >  	mutex_unlock(&v3d->sched_lock);
> > -	drm_gem_unlock_reservations(render->base.bo,
> > -				    render->base.bo_count,
> > &acquire_ctx);
> > +	drm_gem_unlock_reservations(last_job->bo,
> > +				    last_job->bo_count, &acquire_ctx);
> >  fail:
> >  	if (bin)
> >  		v3d_job_put(&bin->base);
> >  	v3d_job_put(&render->base);
> > +	if (clean_job)
> > +		v3d_job_put(clean_job);
> >  
> >  	return ret;
> >  }
> > diff --git a/include/uapi/drm/v3d_drm.h
> > b/include/uapi/drm/v3d_drm.h
> > index 58fbe48c91e9..58d2040ea48c 100644
> > --- a/include/uapi/drm/v3d_drm.h
> > +++ b/include/uapi/drm/v3d_drm.h
> > @@ -48,6 +48,8 @@ extern "C" {
> >  #define DRM_IOCTL_V3D_SUBMIT_TFU          DRM_IOW(DRM_COMMAND_BASE
> > + DRM_V3D_SUBMIT_TFU, struct drm_v3d_submit_tfu)
> >  #define DRM_IOCTL_V3D_SUBMIT_CSD          DRM_IOW(DRM_COMMAND_BASE
> > + DRM_V3D_SUBMIT_CSD, struct drm_v3d_submit_csd)
> >  
> > +#define DRM_V3D_SUBMIT_CL_FLUSH_CACHE_FLAG        0x01
> > +
> >  /**
> >   * struct drm_v3d_submit_cl - ioctl argument for submitting
> > commands to the 3D
> >   * engine.
> > @@ -61,7 +63,7 @@ extern "C" {
> >   * flushed by the time the render done IRQ happens, which is the
> >   * trigger for out_sync.  Any dirtying of cachelines by the job
> > (only
> >   * possible using TMU writes) must be flushed by the caller using
> > the
> > - * CL's cache flush commands.
> > + * DRM_V3D_SUBMIT_CL_FLUSH_CACHE_FLAG flag.
> >   */
> >  struct drm_v3d_submit_cl {
> >  	/* Pointer to the binner command list.
> > @@ -124,8 +126,7 @@ struct drm_v3d_submit_cl {
> >  	/* Number of BO handles passed in (size is that times 4). */
> >  	__u32 bo_handle_count;
> >  
> > -	/* Pad, must be zero-filled. */
> > -	__u32 pad;
> > +	__u32 flags;
> >  };
> >  
> >  /**
> > -- 
> > 2.17.1