On Tue, Nov 21, 2023 at 5:14 AM Dmitry Baryshkov
<dmitry.barysh...@linaro.org> wrote:
>
> On Tue, 21 Nov 2023 at 04:26, Rob Clark <robdcl...@gmail.com> wrote:
> >
> > On Wed, Nov 15, 2023 at 11:33 AM Dmitry Baryshkov
> > <dmitry.barysh...@linaro.org> wrote:
> > >
> > > On Wed, 15 Nov 2023 at 20:46, Dipam Turkar <dipamt1...@gmail.com> wrote:
> > > >
> > > > They are not outdated, my bad. I went through the locks' code and saw
> > > > that they have been updated. But they are probably not necessary here
> > > > as most of the drivers do not use any form of locking in their
> > > > implementations. The generic implementations drm_gem_dumb_map_offset()
> > > > and drm_gem_ttm_dumb_map_offset() do not have any locking mechanisms
> > > > either.
> > >
> > > Excuse me, but this doesn't sound right to me. There are different
> > > drivers with different implementations. So either we'd need a good
> > > explanation of why it is not necessary, or this patch is NAKed.
> >
> > Digging a bit thru history, it looks like commit 0de23977cfeb
> > ("drm/gem: convert to new unified vma manager") made external locking
> > unnecessary, since the vma mgr already had it's own internal locking.
>
> So, should we drop our own locking system?
specifically for _just_ vma_offset_manager/vma_node, we could. But I
think that only amounts to mmap_offset().
BR,
-R
> >
> > BR,
> > -R
> >
> > > >
> > > > Thanks and regards
> > > > Dipam Turkar
> > > >
> > > > On Wed, Nov 15, 2023 at 8:37 PM Dmitry Baryshkov
> > > > <dmitry.barysh...@linaro.org> wrote:
> > > >>
> > > >> On Wed, 15 Nov 2023 at 16:30, Dipam Turkar <dipamt1...@gmail.com>
> > > >> wrote:
> > > >> >
> > > >> > Make msm use drm_gem_create_map_offset() instead of its custom
> > > >> > implementation for associating GEM object with a fake offset. Since,
> > > >> > we already have this generic implementation, we don't need the custom
> > > >> > implementation and it is better to standardize the code for GEM based
> > > >> > drivers. This also removes the outdated locking leftovers.
> > > >>
> > > >> Why are they outdated?
> > > >>
> > > >> >
> > > >> > Signed-off-by: Dipam Turkar <dipamt1...@gmail.com>
> > > >> > ---
> > > >> > drivers/gpu/drm/msm/msm_drv.c | 2 +-
> > > >> > drivers/gpu/drm/msm/msm_gem.c | 21 ---------------------
> > > >> > drivers/gpu/drm/msm/msm_gem.h | 2 --
> > > >> > 3 files changed, 1 insertion(+), 24 deletions(-)
> > > >> >
> > > >> > Changes in v2:
> > > >> > Modify commit message to include the absence of internal locking
> > > >> > leftovers
> > > >> > around allocating a fake offset in msm_gem_mmap_offset() in the
> > > >> > generic
> > > >> > implementation drm_gem_create_map_offset().
> > > >> >
> > > >> > diff --git a/drivers/gpu/drm/msm/msm_drv.c
> > > >> > b/drivers/gpu/drm/msm/msm_drv.c
> > > >> > index a428951ee539..86a15992c717 100644
> > > >> > --- a/drivers/gpu/drm/msm/msm_drv.c
> > > >> > +++ b/drivers/gpu/drm/msm/msm_drv.c
> > > >> > @@ -1085,7 +1085,7 @@ static const struct drm_driver msm_driver = {
> > > >> > .open = msm_open,
> > > >> > .postclose = msm_postclose,
> > > >> > .dumb_create = msm_gem_dumb_create,
> > > >> > - .dumb_map_offset = msm_gem_dumb_map_offset,
> > > >> > + .dumb_map_offset = drm_gem_dumb_map_offset,
> > > >> > .gem_prime_import_sg_table = msm_gem_prime_import_sg_table,
> > > >> > #ifdef CONFIG_DEBUG_FS
> > > >> > .debugfs_init = msm_debugfs_init,
> > > >> > diff --git a/drivers/gpu/drm/msm/msm_gem.c
> > > >> > b/drivers/gpu/drm/msm/msm_gem.c
> > > >> > index db1e748daa75..489694ef79cb 100644
> > > >> > --- a/drivers/gpu/drm/msm/msm_gem.c
> > > >> > +++ b/drivers/gpu/drm/msm/msm_gem.c
> > > >> > @@ -671,27 +671,6 @@ int msm_gem_dumb_create(struct drm_file *file,
> > > >> > struct drm_device *dev,
> > > >> > MSM_BO_SCANOUT | MSM_BO_WC, &args->handle,
> > > >> > "dumb");
> > > >> > }
> > > >> >
> > > >> > -int msm_gem_dumb_map_offset(struct drm_file *file, struct
> > > >> > drm_device *dev,
> > > >> > - uint32_t handle, uint64_t *offset)
> > > >> > -{
> > > >> > - struct drm_gem_object *obj;
> > > >> > - int ret = 0;
> > > >> > -
> > > >> > - /* GEM does all our handle to object mapping */
> > > >> > - obj = drm_gem_object_lookup(file, handle);
> > > >> > - if (obj == NULL) {
> > > >> > - ret = -ENOENT;
> > > >> > - goto fail;
> > > >> > - }
> > > >> > -
> > > >> > - *offset = msm_gem_mmap_offset(obj);
> > > >> > -
> > > >> > - drm_gem_object_put(obj);
> > > >> > -
> > > >> > -fail:
> > > >> > - return ret;
> > > >> > -}
> > > >> > -
> > > >> > static void *get_vaddr(struct drm_gem_object *obj, unsigned madv)
> > > >> > {
> > > >> > struct msm_gem_object *msm_obj = to_msm_bo(obj);
> > > >> > diff --git a/drivers/gpu/drm/msm/msm_gem.h
> > > >> > b/drivers/gpu/drm/msm/msm_gem.h
> > > >> > index 8ddef5443140..dc74a0ef865d 100644
> > > >> > --- a/drivers/gpu/drm/msm/msm_gem.h
> > > >> > +++ b/drivers/gpu/drm/msm/msm_gem.h
> > > >> > @@ -139,8 +139,6 @@ struct page **msm_gem_pin_pages(struct
> > > >> > drm_gem_object *obj);
> > > >> > void msm_gem_unpin_pages(struct drm_gem_object *obj);
> > > >> > int msm_gem_dumb_create(struct drm_file *file, struct drm_device
> > > >> > *dev,
> > > >> > struct drm_mode_create_dumb *args);
> > > >> > -int msm_gem_dumb_map_offset(struct drm_file *file, struct
> > > >> > drm_device *dev,
> > > >> > - uint32_t handle, uint64_t *offset);
> > > >> > void *msm_gem_get_vaddr_locked(struct drm_gem_object *obj);
> > > >> > void *msm_gem_get_vaddr(struct drm_gem_object *obj);
> > > >> > void *msm_gem_get_vaddr_active(struct drm_gem_object *obj);
> > > >> > --
> > > >> > 2.34.1
> > > >> >
> > > >>
> > > >>
> > > >> --
> > > >> With best wishes
> > > >> Dmitry
> > >
> > >
> > >
> > > --
> > > With best wishes
> > > Dmitry
>
>
>
> --
> With best wishes
> Dmitry
