Re: [PATCH v2 2/4] drm/v3d: alloc and init job in one shot

On Wed, 2021-09-29 at 10:43 +0100, Melissa Wen wrote:

Move job memory allocation to v3d_job_init function. This aim to facilitate error handling in job initialization, since cleanup steps are similar for all (struct v3d_job)-based types of job involved in a command submission. To generalize v3d_job_init(), this change takes into account that all job structs have the first element a struct v3d_job (bin, render, tfu, csd) or it is a v3d_job itself (clean_job) for pointer casting.

Suggested-by: Iago Toral itoral@igalia.com Signed-off-by: Melissa Wen mwen@igalia.com

---

drivers/gpu/drm/v3d/v3d_gem.c | 115 +++++++++++++-------------------

1 file changed, 42 insertions(+), 73 deletions(-)

diff --git a/drivers/gpu/drm/v3d/v3d_gem.c b/drivers/gpu/drm/v3d/v3d_gem.c index e60fbc28ef29..9cfa6f8d4357 100644 --- a/drivers/gpu/drm/v3d/v3d_gem.c +++ b/drivers/gpu/drm/v3d/v3d_gem.c @@ -392,6 +392,9 @@ v3d_render_job_free(struct kref *ref)

void v3d_job_cleanup(struct v3d_job *job) {

• if (!job)

• return;
  

• drm_sched_job_cleanup(&job->base); v3d_job_put(job);

} @@ -450,12 +453,20 @@ v3d_job_add_deps(struct drm_file *file_priv, struct v3d_job *job,

static int v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv,

•     struct v3d_job *job, void (*free)(struct kref *ref),
  

•     void **container, size_t size, void (*free)(struct kref
  

*ref), u32 in_sync, enum v3d_queue queue) { struct v3d_file_priv *v3d_priv = file_priv->driver_priv;

• struct v3d_job *job; int ret;

• *container = kcalloc(1, size, GFP_KERNEL);

• if (!*container) {

• DRM_ERROR("Cannot allocate memory for v3d job.");
  

• return -ENOMEM;
  

• }

• job = *container; job->v3d = v3d; job->free = free;

Right below this hunk we have an early return that doesn't jump to fail:

ret = pm_runtime_get_sync(v3d->drm.dev); if (ret < 0) return ret;

so we should kfree(*container) and set it to NULL there, right?

@@ -479,6 +490,9 @@ v3d_job_init(struct v3d_dev *v3d, struct drm_file *file_priv, drm_sched_job_cleanup(&job->base); fail: pm_runtime_put_autosuspend(v3d->drm.dev);

• kfree(*container);
• *container = NULL;
• return ret;

}

(...)

@@ -806,29 +789,15 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data, return -EINVAL; }

• job = kcalloc(1, sizeof(*job), GFP_KERNEL);
• if (!job)

• return -ENOMEM;
  

• ret = v3d_job_init(v3d, file_priv, &job->base,

• ret = v3d_job_init(v3d, file_priv, (void *)&job, sizeof(*job), v3d_job_free, args->in_sync, V3D_CSD);

• if (ret) {

• kfree(job);
  

• return ret;
  

• }
• clean_job = kcalloc(1, sizeof(*clean_job), GFP_KERNEL);
• if (!clean_job) {

• v3d_job_cleanup(&job->base);
  

• return -ENOMEM;
  

• }

• if (ret)

• goto fail;
  
  

For this to work we need to explicitly initialize clean_job to NULL. Notice that the same applies to the bin and clean jobs in the CL ioctl, but in that case we're already initializing them to NULL.

• ret = v3d_job_init(v3d, file_priv, clean_job, v3d_job_free, 0,

V3D_CACHE_CLEAN);

• if (ret) {

• v3d_job_cleanup(&job->base);
  

• kfree(clean_job);
  

• return ret;
  

• }

• ret = v3d_job_init(v3d, file_priv, (void *)&clean_job,

sizeof(*clean_job),

• 	   v3d_job_free, 0, V3D_CACHE_CLEAN);
  

• if (ret)

• goto fail;
  
  

  job->args = *args;

@@ -877,7 +846,7 @@ v3d_submit_csd_ioctl(struct drm_device *dev, void *data, drm_gem_unlock_reservations(clean_job->bo, clean_job->bo_count, &acquire_ctx); fail:

• v3d_job_cleanup(&job->base);

• v3d_job_cleanup((void *)job); v3d_job_cleanup(clean_job);

  return ret;