On Sun, Jun 6, 2021 at 3:53 AM Christian König
<ckoenig.leichtzumerken@xxxxxxxxx> wrote:
>
> Am 02.06.21 um 22:22 schrieb Jason Ekstrand:
> > On Wed, Jun 2, 2021 at 6:17 AM Christian König
> > <ckoenig.leichtzumerken@xxxxxxxxx> wrote:
> >> When the comment needs to state explicitly that this is doesn't get a reference
> >> to the object then the function is named rather badly.
> >>
> >> Rename the function and use it in even more places.
> >>
> >> Signed-off-by: Christian König <christian.koenig@xxxxxxx>
> >> ---
> >> drivers/dma-buf/dma-resv.c | 32 +++++++++----------
> >> .../gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c | 2 +-
> >> drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c | 2 +-
> >> drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c | 2 +-
> >> drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c | 2 +-
> >> drivers/gpu/drm/etnaviv/etnaviv_gem.c | 2 +-
> >> drivers/gpu/drm/i915/gem/i915_gem_busy.c | 2 +-
> >> drivers/gpu/drm/msm/msm_gem.c | 4 +--
> >> drivers/gpu/drm/nouveau/nouveau_fence.c | 2 +-
> >> drivers/gpu/drm/qxl/qxl_debugfs.c | 2 +-
> >> drivers/gpu/drm/radeon/radeon_sync.c | 2 +-
> >> drivers/gpu/drm/ttm/ttm_bo.c | 2 +-
> >> include/linux/dma-resv.h | 25 +++++++--------
> >> 13 files changed, 39 insertions(+), 42 deletions(-)
> >>
> >> diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
> >> index 81b032b43457..b1a1a31dc009 100644
> >> --- a/drivers/dma-buf/dma-resv.c
> >> +++ b/drivers/dma-buf/dma-resv.c
> >> @@ -149,8 +149,7 @@ int dma_resv_reserve_shared(struct dma_resv *obj, unsigned int num_fences)
> >>
> >> dma_resv_assert_held(obj);
> >>
> >> - old = dma_resv_get_list(obj);
> >> -
> >> + old = dma_resv_shared(obj);
> >> if (old && old->shared_max) {
> >> if ((old->shared_count + num_fences) <= old->shared_max)
> >> return 0;
> >> @@ -217,12 +216,13 @@ EXPORT_SYMBOL(dma_resv_reserve_shared);
> >> */
> >> void dma_resv_reset_shared_max(struct dma_resv *obj)
> >> {
> >> - /* Test shared fence slot reservation */
> >> - if (rcu_access_pointer(obj->fence)) {
> >> - struct dma_resv_list *fence = dma_resv_get_list(obj);
> >> + struct dma_resv_list *fences = dma_resv_shared(obj);
> >>
> >> - fence->shared_max = fence->shared_count;
> >> - }
> >> + dma_resv_assert_held(obj);
> > Does it make sense to assert we hold the lock *before* we touch it
> > with something that requires that we do? Maybe it doesn't matter?
>
> As far as I can see that shouldn't matter.
>
> >
> >> +
> >> + /* Test shared fence slot reservation */
> >> + if (fences)
> >> + fences->shared_max = fences->shared_count;
> >> }
> >> #endif
> >>
> >> @@ -244,7 +244,7 @@ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence)
> >>
> >> dma_resv_assert_held(obj);
> >>
> >> - fobj = dma_resv_get_list(obj);
> >> + fobj = dma_resv_shared(obj);
> >> count = fobj->shared_count;
> >>
> >> write_seqcount_begin(&obj->seq);
> >> @@ -287,7 +287,7 @@ void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence)
> >>
> >> dma_resv_assert_held(obj);
> >>
> >> - old = dma_resv_get_list(obj);
> >> + old = dma_resv_shared(obj);
> >> if (old)
> >> i = old->shared_count;
> >>
> >> @@ -326,7 +326,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
> >> dma_resv_assert_held(dst);
> >>
> >> rcu_read_lock();
> >> - src_list = rcu_dereference(src->fence);
> >> + src_list = dma_resv_shared(src);
> >>
> >> retry:
> >> if (src_list) {
> >> @@ -339,7 +339,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
> >> return -ENOMEM;
> >>
> >> rcu_read_lock();
> >> - src_list = rcu_dereference(src->fence);
> >> + src_list = dma_resv_shared(src);
> >> if (!src_list || src_list->shared_count > shared_count) {
> >> kfree(dst_list);
> >> goto retry;
> >> @@ -357,7 +357,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
> >>
> >> if (!dma_fence_get_rcu(fence)) {
> >> dma_resv_list_free(dst_list);
> >> - src_list = rcu_dereference(src->fence);
> >> + src_list = dma_resv_shared(src);
> >> goto retry;
> >> }
> >>
> >> @@ -376,7 +376,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
> >> new = dma_fence_get_rcu_safe(&src->fence_excl);
> >> rcu_read_unlock();
> >>
> >> - src_list = dma_resv_get_list(dst);
> >> + src_list = dma_resv_shared(dst);
> >> old = dma_resv_exclusive(dst);
> >>
> >> write_seqcount_begin(&dst->seq);
> >> @@ -429,7 +429,7 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj,
> >> if (fence_excl && !dma_fence_get_rcu(fence_excl))
> >> goto unlock;
> >>
> >> - fobj = rcu_dereference(obj->fence);
> >> + fobj = dma_resv_shared(obj);
> >> if (fobj)
> >> sz += sizeof(*shared) * fobj->shared_max;
> >>
> >> @@ -535,7 +535,7 @@ long dma_resv_wait_timeout_rcu(struct dma_resv *obj,
> >> }
> >>
> >> if (wait_all) {
> >> - struct dma_resv_list *fobj = rcu_dereference(obj->fence);
> >> + struct dma_resv_list *fobj = dma_resv_shared(obj);
> >>
> >> if (fobj)
> >> shared_count = fobj->shared_count;
> >> @@ -620,7 +620,7 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
> >> seq = read_seqcount_begin(&obj->seq);
> >>
> >> if (test_all) {
> >> - struct dma_resv_list *fobj = rcu_dereference(obj->fence);
> >> + struct dma_resv_list *fobj = dma_resv_shared(obj);
> >> unsigned int i;
> >>
> >> if (fobj)
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> >> index d5e6519bdea1..e90495ca49fd 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd_gpuvm.c
> >> @@ -247,7 +247,7 @@ static int amdgpu_amdkfd_remove_eviction_fence(struct amdgpu_bo *bo,
> >> if (!ef)
> >> return -EINVAL;
> >>
> >> - old = dma_resv_get_list(resv);
> >> + old = dma_resv_shared(resv);
> >> if (!old)
> >> return 0;
> >>
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> >> index 6dd0ea6e9e24..3b13c8a38c4e 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
> >> @@ -49,7 +49,7 @@ __dma_resv_make_exclusive(struct dma_resv *obj)
> >> unsigned int count;
> >> int r;
> >>
> >> - if (!dma_resv_get_list(obj)) /* no shared fences to convert */
> >> + if (!dma_resv_shared(obj)) /* no shared fences to convert */
> >> return 0;
> >>
> >> r = dma_resv_get_fences_rcu(obj, NULL, &count, &fences);
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> >> index c84d5b843985..c50d9f92a0cd 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_sync.c
> >> @@ -213,7 +213,7 @@ int amdgpu_sync_resv(struct amdgpu_device *adev, struct amdgpu_sync *sync,
> >> f = dma_resv_exclusive(resv);
> >> r = amdgpu_sync_fence(sync, f);
> >>
> >> - flist = dma_resv_get_list(resv);
> >> + flist = dma_resv_shared(resv);
> >> if (!flist || r)
> >> return r;
> >>
> >> diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> >> index 663aa7d2e2ea..ddb6ce7d48bc 100644
> >> --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> >> +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ttm.c
> >> @@ -1338,7 +1338,7 @@ static bool amdgpu_ttm_bo_eviction_valuable(struct ttm_buffer_object *bo,
> >> * If true, then return false as any KFD process needs all its BOs to
> >> * be resident to run successfully
> >> */
> >> - flist = dma_resv_get_list(bo->base.resv);
> >> + flist = dma_resv_shared(bo->base.resv);
> >> if (flist) {
> >> for (i = 0; i < flist->shared_count; ++i) {
> >> f = rcu_dereference_protected(flist->shared[i],
> >> diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
> >> index d4f54dea8ac1..4d43b8630f0e 100644
> >> --- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
> >> +++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
> >> @@ -461,7 +461,7 @@ static void etnaviv_gem_describe(struct drm_gem_object *obj, struct seq_file *m)
> >> off, etnaviv_obj->vaddr, obj->size);
> >>
> >> rcu_read_lock();
> >> - fobj = rcu_dereference(robj->fence);
> >> + fobj = dma_resv_shared(robj);
> >> if (fobj) {
> >> unsigned int i, shared_count = fobj->shared_count;
> >>
> >> diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
> >> index 02312a0c3a36..3f94becac541 100644
> >> --- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c
> >> +++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
> >> @@ -116,7 +116,7 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
> >> args->busy = busy_check_writer(dma_resv_exclusive(obj->base.resv));
> >>
> >> /* Translate shared fences to READ set of engines */
> >> - list = rcu_dereference(obj->base.resv->fence);
> >> + list = dma_resv_shared(obj->base.resv);
> >> if (list) {
> >> unsigned int shared_count = list->shared_count, i;
> >>
> >> diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
> >> index 54c1b53426d6..43af91df552e 100644
> >> --- a/drivers/gpu/drm/msm/msm_gem.c
> >> +++ b/drivers/gpu/drm/msm/msm_gem.c
> >> @@ -817,7 +817,7 @@ int msm_gem_sync_object(struct drm_gem_object *obj,
> >> struct dma_fence *fence;
> >> int i, ret;
> >>
> >> - fobj = dma_resv_get_list(obj->resv);
> >> + fobj = dma_resv_shared(obj->resv);
> >> if (!fobj || (fobj->shared_count == 0)) {
> >> fence = dma_resv_exclusive(obj->resv);
> >> /* don't need to wait on our own fences, since ring is fifo */
> >> @@ -1025,7 +1025,7 @@ void msm_gem_describe(struct drm_gem_object *obj, struct seq_file *m,
> >> }
> >>
> >> rcu_read_lock();
> >> - fobj = rcu_dereference(robj->fence);
> >> + fobj = dma_resv_shared(robj);
> >> if (fobj) {
> >> unsigned int i, shared_count = fobj->shared_count;
> >>
> >> diff --git a/drivers/gpu/drm/nouveau/nouveau_fence.c b/drivers/gpu/drm/nouveau/nouveau_fence.c
> >> index a6cb35181aee..5ce441c655ea 100644
> >> --- a/drivers/gpu/drm/nouveau/nouveau_fence.c
> >> +++ b/drivers/gpu/drm/nouveau/nouveau_fence.c
> >> @@ -355,7 +355,7 @@ nouveau_fence_sync(struct nouveau_bo *nvbo, struct nouveau_channel *chan, bool e
> >> return ret;
> >> }
> >>
> >> - fobj = dma_resv_get_list(resv);
> >> + fobj = dma_resv_shared(resv);
> >> fence = dma_resv_exclusive(resv);
> >>
> >> if (fence && (!exclusive || !fobj || !fobj->shared_count)) {
> >> diff --git a/drivers/gpu/drm/qxl/qxl_debugfs.c b/drivers/gpu/drm/qxl/qxl_debugfs.c
> >> index 183d15e2cf58..0acc70a6d3dd 100644
> >> --- a/drivers/gpu/drm/qxl/qxl_debugfs.c
> >> +++ b/drivers/gpu/drm/qxl/qxl_debugfs.c
> >> @@ -61,7 +61,7 @@ qxl_debugfs_buffers_info(struct seq_file *m, void *data)
> >> int rel;
> >>
> >> rcu_read_lock();
> >> - fobj = rcu_dereference(bo->tbo.base.resv->fence);
> >> + fobj = dma_resv_shared(bo->tbo.base.resv);
> >> rel = fobj ? fobj->shared_count : 0;
> >> rcu_read_unlock();
> >>
> >> diff --git a/drivers/gpu/drm/radeon/radeon_sync.c b/drivers/gpu/drm/radeon/radeon_sync.c
> >> index e476f90ef1c1..a9cdb88da173 100644
> >> --- a/drivers/gpu/drm/radeon/radeon_sync.c
> >> +++ b/drivers/gpu/drm/radeon/radeon_sync.c
> >> @@ -105,7 +105,7 @@ int radeon_sync_resv(struct radeon_device *rdev,
> >> else if (f)
> >> r = dma_fence_wait(f, true);
> >>
> >> - flist = dma_resv_get_list(resv);
> >> + flist = dma_resv_shared(resv);
> >> if (shared || !flist || r)
> >> return r;
> >>
> >> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
> >> index 92361556bf0b..c41ef0caa492 100644
> >> --- a/drivers/gpu/drm/ttm/ttm_bo.c
> >> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
> >> @@ -261,7 +261,7 @@ static void ttm_bo_flush_all_fences(struct ttm_buffer_object *bo)
> >> int i;
> >>
> >> rcu_read_lock();
> >> - fobj = rcu_dereference(resv->fence);
> >> + fobj = dma_resv_shared(resv);
> >> fence = dma_resv_exclusive(resv);
> >> if (fence && !fence->ops->signaled)
> >> dma_fence_enable_sw_signaling(fence);
> >> diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h
> >> index 7549ec5eb35c..98ac66fecb71 100644
> >> --- a/include/linux/dma-resv.h
> >> +++ b/include/linux/dma-resv.h
> >> @@ -78,20 +78,6 @@ struct dma_resv {
> >> #define dma_resv_held(obj) lockdep_is_held(&(obj)->lock.base)
> >> #define dma_resv_assert_held(obj) lockdep_assert_held(&(obj)->lock.base)
> >>
> >> -/**
> >> - * dma_resv_get_list - get the reservation object's
> >> - * shared fence list, with update-side lock held
> >> - * @obj: the reservation object
> >> - *
> >> - * Returns the shared fence list. Does NOT take references to
> >> - * the fence. The obj->lock must be held.
> >> - */
> >> -static inline struct dma_resv_list *dma_resv_get_list(struct dma_resv *obj)
> >> -{
> >> - return rcu_dereference_protected(obj->fence,
> >> - dma_resv_held(obj));
> >> -}
> >> -
> >> #ifdef CONFIG_DEBUG_MUTEXES
> >> void dma_resv_reset_shared_max(struct dma_resv *obj);
> >> #else
> >> @@ -267,6 +253,17 @@ dma_resv_get_excl_rcu(struct dma_resv *obj)
> >> return fence;
> >> }
> >>
> >> +/**
> >> + * dma_resv_shared - get the reservation object's shared fence list
> >> + * @obj: the reservation object
> >> + *
> >> + * Returns the shared fence list. The obj->lock or rcu read side must be held.
> >> + */
> >> +static inline struct dma_resv_list *dma_resv_shared(struct dma_resv *obj)
> > Maybe dma_resv_shared_list() just to be a little more clear what's
> > being returned?
>
> Ok, renamed this one and dma_resv_exclusive into dma_resv_excl_fence as
> well.
Cool
Reviewed-by: Jason Ekstrand <jason@xxxxxxxxxxxxxx>
then. Any more left needing review?
--Jason
> Christian.
>
> >
> > --Jason
> >
> >> +{
> >> + return rcu_dereference_check(obj->fence, dma_resv_held(obj));
> >> +}
> >> +
> >> void dma_resv_init(struct dma_resv *obj);
> >> void dma_resv_fini(struct dma_resv *obj);
> >> int dma_resv_reserve_shared(struct dma_resv *obj, unsigned int num_fences);
> >> --
> >> 2.25.1
> >>
>
