On Wed, Nov 15, 2023 at 11:33 AM Dmitry Baryshkov
<[email protected]> wrote:
>
> On Wed, 15 Nov 2023 at 20:46, Dipam Turkar <[email protected]> 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 They are not outdated, my bad.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.
BR,
-R
> >
> > Thanks and regards
> > Dipam Turkar
> >
> > On Wed, Nov 15, 2023 at 8:37 PM Dmitry Baryshkov
> > <[email protected]> wrote:
> >>
> >> On Wed, 15 Nov 2023 at 16:30, Dipam Turkar <[email protected]> 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 This also removes the outdated locking leftovers.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 Why are they outdated?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 <[email protected]>
> >> > ---
> >> > 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
