Re: [PATCH 1/3] Revert "drm/prime: Unexport helpers for fd/handle conversion"

[Felix Kuehling <felix.kuehling@xxxxxxx>]

On 2023-11-28 12:22, Alex Deucher wrote:
> On Thu, Nov 23, 2023 at 6:12 PM Felix Kuehling <felix.kuehling@xxxxxxx> wrote:
> > [+Alex]
> >
> > On 2023-11-17 16:44, Felix Kuehling wrote:
> >
> > > This reverts commit 71a7974ac7019afeec105a54447ae1dc7216cbb3.
> > >
> > > These helper functions are needed for KFD to export and import DMABufs
> > > the right way without duplicating the tracking of DMABufs associated with
> > > GEM objects while ensuring that move notifier callbacks are working as
> > > intended.
> > >
> > > CC: Christian König <christian.koenig@xxxxxxx>
> > > CC: Thomas Zimmermann <tzimmermann@xxxxxxx>
> > > Signed-off-by: Felix Kuehling <Felix.Kuehling@xxxxxxx>
> > Re: our discussion about v2 of this patch: If this version is
> > acceptable, can I get an R-b or A-b?
> >
> > I would like to get this patch into drm-next as a prerequisite for
> > patches 2 and 3. I cannot submit it to the current amd-staging-drm-next
> > because the patch I'm reverting doesn't exist there yet.
> >
> > Patch 2 and 3 could go into drm-next as well, or go through Alex's
> > amd-staging-drm-next branch once patch 1 is in drm-next. Alex, how do
> > you prefer to coordinate this?
> I guess ideally this would go through my drm-next tree since your
> other patches depend on it unless others feel strongly that it should
> go through drm-misc.

Yes, drm-next would work best for applying this patch and the two 
patches that depend on it. I can send you the rebased patches from my 
drm-next based branch that I used for testing this.

Regards,
  Felix


> Alex
>
>
> > Regards,
> >     Felix
> >
> >
> > > ---
> > >    drivers/gpu/drm/drm_prime.c | 33 ++++++++++++++++++---------------
> > >    include/drm/drm_prime.h     |  7 +++++++
> > >    2 files changed, 25 insertions(+), 15 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/drm_prime.c b/drivers/gpu/drm/drm_prime.c
> > > index 63b709a67471..834a5e28abbe 100644
> > > --- a/drivers/gpu/drm/drm_prime.c
> > > +++ b/drivers/gpu/drm/drm_prime.c
> > > @@ -278,7 +278,7 @@ void drm_gem_dmabuf_release(struct dma_buf *dma_buf)
> > >    }
> > >    EXPORT_SYMBOL(drm_gem_dmabuf_release);
> > >
> > > -/*
> > > +/**
> > >     * drm_gem_prime_fd_to_handle - PRIME import function for GEM drivers
> > >     * @dev: drm_device to import into
> > >     * @file_priv: drm file-private structure
> > > @@ -292,9 +292,9 @@ EXPORT_SYMBOL(drm_gem_dmabuf_release);
> > >     *
> > >     * Returns 0 on success or a negative error code on failure.
> > >     */
> > > -static int drm_gem_prime_fd_to_handle(struct drm_device *dev,
> > > -                                   struct drm_file *file_priv, int prime_fd,
> > > -                                   uint32_t *handle)
> > > +int drm_gem_prime_fd_to_handle(struct drm_device *dev,
> > > +                            struct drm_file *file_priv, int prime_fd,
> > > +                            uint32_t *handle)
> > >    {
> > >        struct dma_buf *dma_buf;
> > >        struct drm_gem_object *obj;
> > > @@ -360,6 +360,7 @@ static int drm_gem_prime_fd_to_handle(struct drm_device *dev,
> > >        dma_buf_put(dma_buf);
> > >        return ret;
> > >    }
> > > +EXPORT_SYMBOL(drm_gem_prime_fd_to_handle);
> > >
> > >    int drm_prime_fd_to_handle_ioctl(struct drm_device *dev, void *data,
> > >                                 struct drm_file *file_priv)
> > > @@ -408,7 +409,7 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,
> > >        return dmabuf;
> > >    }
> > >
> > > -/*
> > > +/**
> > >     * drm_gem_prime_handle_to_fd - PRIME export function for GEM drivers
> > >     * @dev: dev to export the buffer from
> > >     * @file_priv: drm file-private structure
> > > @@ -421,10 +422,10 @@ static struct dma_buf *export_and_register_object(struct drm_device *dev,
> > >     * The actual exporting from GEM object to a dma-buf is done through the
> > >     * &drm_gem_object_funcs.export callback.
> > >     */
> > > -static int drm_gem_prime_handle_to_fd(struct drm_device *dev,
> > > -                                   struct drm_file *file_priv, uint32_t handle,
> > > -                                   uint32_t flags,
> > > -                                   int *prime_fd)
> > > +int drm_gem_prime_handle_to_fd(struct drm_device *dev,
> > > +                            struct drm_file *file_priv, uint32_t handle,
> > > +                            uint32_t flags,
> > > +                            int *prime_fd)
> > >    {
> > >        struct drm_gem_object *obj;
> > >        int ret = 0;
> > > @@ -506,6 +507,7 @@ static int drm_gem_prime_handle_to_fd(struct drm_device *dev,
> > >
> > >        return ret;
> > >    }
> > > +EXPORT_SYMBOL(drm_gem_prime_handle_to_fd);
> > >
> > >    int drm_prime_handle_to_fd_ioctl(struct drm_device *dev, void *data,
> > >                                 struct drm_file *file_priv)
> > > @@ -864,9 +866,9 @@ EXPORT_SYMBOL(drm_prime_get_contiguous_size);
> > >     * @obj: GEM object to export
> > >     * @flags: flags like DRM_CLOEXEC and DRM_RDWR
> > >     *
> > > - * This is the implementation of the &drm_gem_object_funcs.export functions
> > > - * for GEM drivers using the PRIME helpers. It is used as the default for
> > > - * drivers that do not set their own.
> > > + * This is the implementation of the &drm_gem_object_funcs.export functions for GEM drivers
> > > + * using the PRIME helpers. It is used as the default in
> > > + * drm_gem_prime_handle_to_fd().
> > >     */
> > >    struct dma_buf *drm_gem_prime_export(struct drm_gem_object *obj,
> > >                                     int flags)
> > > @@ -962,9 +964,10 @@ EXPORT_SYMBOL(drm_gem_prime_import_dev);
> > >     * @dev: drm_device to import into
> > >     * @dma_buf: dma-buf object to import
> > >     *
> > > - * This is the implementation of the gem_prime_import functions for GEM
> > > - * drivers using the PRIME helpers. It is the default for drivers that do
> > > - * not set their own &drm_driver.gem_prime_import.
> > > + * This is the implementation of the gem_prime_import functions for GEM drivers
> > > + * using the PRIME helpers. Drivers can use this as their
> > > + * &drm_driver.gem_prime_import implementation. It is used as the default
> > > + * implementation in drm_gem_prime_fd_to_handle().
> > >     *
> > >     * Drivers must arrange to call drm_prime_gem_destroy() from their
> > >     * &drm_gem_object_funcs.free hook when using this function.
> > > diff --git a/include/drm/drm_prime.h b/include/drm/drm_prime.h
> > > index a7abf9f3e697..2a1d01e5b56b 100644
> > > --- a/include/drm/drm_prime.h
> > > +++ b/include/drm/drm_prime.h
> > > @@ -60,12 +60,19 @@ enum dma_data_direction;
> > >
> > >    struct drm_device;
> > >    struct drm_gem_object;
> > > +struct drm_file;
> > >
> > >    /* core prime functions */
> > >    struct dma_buf *drm_gem_dmabuf_export(struct drm_device *dev,
> > >                                      struct dma_buf_export_info *exp_info);
> > >    void drm_gem_dmabuf_release(struct dma_buf *dma_buf);
> > >
> > > +int drm_gem_prime_fd_to_handle(struct drm_device *dev,
> > > +                            struct drm_file *file_priv, int prime_fd, uint32_t *handle);
> > > +int drm_gem_prime_handle_to_fd(struct drm_device *dev,
> > > +                            struct drm_file *file_priv, uint32_t handle, uint32_t flags,
> > > +                            int *prime_fd);
> > > +
> > >    /* helper functions for exporting */
> > >    int drm_gem_map_attach(struct dma_buf *dma_buf,
> > >                       struct dma_buf_attachment *attach);