[PATCH v2 1/6] drm/gem: refine drm_gem_objects_lookup
Qiang Yu
yuq825 at gmail.com
Sun Sep 29 06:07:57 UTC 2019
On Fri, Sep 27, 2019 at 9:57 PM Steven Price <steven.price at arm.com> wrote:
>
> On 27/09/2019 14:46, Qiang Yu wrote:
> > drm_gem_objects_lookup does not use user space bo handles
> > directly and left the user to kernel copy work to a new
> > interface drm_gem_objects_lookup_user.
> >
> > This is for driver like lima which does not pass gem bo
> > handles continously in an array in ioctl argument.
>
> Nit: It would be good to mention in the commit message that this adds
> drm_gem_objects_lookup_user() as it helps grepping commits. Also if
> you're rewriting it - it would be good to point out that you are
> _changing_ the behvaviour of drm_gem_objects_lookpu() to not use user
> space handles.
>
OK, I can improve the comments of two patches in v3.
Thanks,
Qiang
> >
> > v2:
> > 1. add drm_gem_objects_lookup_user
> > 2. remove none-zero check as all caller will check before
> > calling this function
> >
> > Cc: Rob Herring <robh at kernel.org>
> > Cc: Tomeu Vizoso <tomeu.vizoso at collabora.com>
> > Cc: Steven Price <steven.price at arm.com>
> > Cc: Alyssa Rosenzweig <alyssa.rosenzweig at collabora.com>
> > Suggested-by: Rob Herring <robh at kernel.org>
> > Signed-off-by: Qiang Yu <yuq825 at gmail.com>
>
> Reviewed-by: Steven Price <steven.price at arm.com>
>
> > ---
> > drivers/gpu/drm/drm_gem.c | 57 +++++++++++++++++++------
> > drivers/gpu/drm/panfrost/panfrost_drv.c | 6 +--
> > include/drm/drm_gem.h | 4 +-
> > 3 files changed, 49 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
> > index 6854f5867d51..a5e88c3e6d25 100644
> > --- a/drivers/gpu/drm/drm_gem.c
> > +++ b/drivers/gpu/drm/drm_gem.c
> > @@ -679,11 +679,11 @@ static int objects_lookup(struct drm_file *filp, u32 *handle, int count,
> > /**
> > * drm_gem_objects_lookup - look up GEM objects from an array of handles
> > * @filp: DRM file private date
> > - * @bo_handles: user pointer to array of userspace handle
> > + * @bo_handles: array of GEM object handles
> > * @count: size of handle array
> > * @objs_out: returned pointer to array of drm_gem_object pointers
> > *
> > - * Takes an array of userspace handles and returns a newly allocated array of
> > + * Takes an array of GEM object handles and returns a newly allocated array of
> > * GEM objects.
> > *
> > * For a single handle lookup, use drm_gem_object_lookup().
> > @@ -695,26 +695,56 @@ static int objects_lookup(struct drm_file *filp, u32 *handle, int count,
> > * failure. 0 is returned on success.
> > *
> > */
> > -int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
> > +int drm_gem_objects_lookup(struct drm_file *filp, u32 *bo_handles,
> > int count, struct drm_gem_object ***objs_out)
> > {
> > int ret;
> > - u32 *handles;
> > struct drm_gem_object **objs;
> >
> > - if (!count)
> > - return 0;
> > -
> > objs = kvmalloc_array(count, sizeof(struct drm_gem_object *),
> > GFP_KERNEL | __GFP_ZERO);
> > if (!objs)
> > return -ENOMEM;
> >
> > + ret = objects_lookup(filp, bo_handles, count, objs);
> > + if (ret)
> > + kvfree(objs);
> > + else
> > + *objs_out = objs;
> > +
> > + return ret;
> > +
> > +}
> > +EXPORT_SYMBOL(drm_gem_objects_lookup);
> > +
> > +/**
> > + * drm_gem_objects_lookup_user - look up GEM objects from an array of handles
> > + * @filp: DRM file private date
> > + * @bo_handles: user pointer to array of userspace handle
> > + * @count: size of handle array
> > + * @objs_out: returned pointer to array of drm_gem_object pointers
> > + *
> > + * Takes an array of userspace handles and returns a newly allocated array of
> > + * GEM objects.
> > + *
> > + * For a single handle lookup, use drm_gem_object_lookup().
> > + *
> > + * Returns:
> > + *
> > + * @objs filled in with GEM object pointers. Returned GEM objects need to be
> > + * released with drm_gem_object_put(). -ENOENT is returned on a lookup
> > + * failure. 0 is returned on success.
> > + *
> > + */
> > +int drm_gem_objects_lookup_user(struct drm_file *filp, void __user *bo_handles,
> > + int count, struct drm_gem_object ***objs_out)
> > +{
> > + int ret;
> > + u32 *handles;
> > +
> > handles = kvmalloc_array(count, sizeof(u32), GFP_KERNEL);
> > - if (!handles) {
> > - ret = -ENOMEM;
> > - goto out;
> > - }
> > + if (!handles)
> > + return -ENOMEM;
> >
> > if (copy_from_user(handles, bo_handles, count * sizeof(u32))) {
> > ret = -EFAULT;
> > @@ -722,15 +752,14 @@ int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
> > goto out;
> > }
> >
> > - ret = objects_lookup(filp, handles, count, objs);
> > - *objs_out = objs;
> > + ret = drm_gem_objects_lookup(filp, handles, count, objs_out);
> >
> > out:
> > kvfree(handles);
> > return ret;
> >
> > }
> > -EXPORT_SYMBOL(drm_gem_objects_lookup);
> > +EXPORT_SYMBOL(drm_gem_objects_lookup_user);
> >
> > /**
> > * drm_gem_object_lookup - look up a GEM object from its handle
> > diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
> > index d74442d71048..486ca51d5662 100644
> > --- a/drivers/gpu/drm/panfrost/panfrost_drv.c
> > +++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
> > @@ -130,9 +130,9 @@ panfrost_lookup_bos(struct drm_device *dev,
> > if (!job->implicit_fences)
> > return -ENOMEM;
> >
> > - return drm_gem_objects_lookup(file_priv,
> > - (void __user *)(uintptr_t)args->bo_handles,
> > - job->bo_count, &job->bos);
> > + return drm_gem_objects_lookup_user(file_priv,
> > + (void __user *)(uintptr_t)args->bo_handles,
> > + job->bo_count, &job->bos);
> > }
> >
> > /**
> > diff --git a/include/drm/drm_gem.h b/include/drm/drm_gem.h
> > index 6aaba14f5972..354fc8d240e4 100644
> > --- a/include/drm/drm_gem.h
> > +++ b/include/drm/drm_gem.h
> > @@ -387,8 +387,10 @@ struct page **drm_gem_get_pages(struct drm_gem_object *obj);
> > void drm_gem_put_pages(struct drm_gem_object *obj, struct page **pages,
> > bool dirty, bool accessed);
> >
> > -int drm_gem_objects_lookup(struct drm_file *filp, void __user *bo_handles,
> > +int drm_gem_objects_lookup(struct drm_file *filp, u32 *bo_handles,
> > int count, struct drm_gem_object ***objs_out);
> > +int drm_gem_objects_lookup_user(struct drm_file *filp, void __user *bo_handles,
> > + int count, struct drm_gem_object ***objs_out);
> > struct drm_gem_object *drm_gem_object_lookup(struct drm_file *filp, u32 handle);
> > long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle,
> > bool wait_all, unsigned long timeout);
> >
>
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