Re: [PATCH 2/7] dma-buf: Rename dma_resv helpers from _rcu to _unlocked (v2)

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Am 27.05.21 um 15:25 schrieb Daniel Vetter:
On Thu, May 27, 2021 at 1:59 PM Christian König
<christian.koenig@xxxxxxx> wrote:
Am 27.05.21 um 12:39 schrieb Daniel Vetter:
On Wed, May 26, 2021 at 12:57:40PM +0200, Christian König wrote:
Am 25.05.21 um 23:17 schrieb Jason Ekstrand:
None of these helpers actually leak any RCU details to the caller.  They
all assume you have a genuine reference, take the RCU read lock, and
retry if needed.  Naming them with an _rcu is likely to cause callers
more panic than needed.
I'm really wondering if we need this postfix in the first place.

If we use the right rcu_dereference_check() macro then those functions can
be called with both the reservation object locked and unlocked. It shouldn't
matter to them.

But getting rid of the _rcu postfix sounds like a good idea in general to
me.
So does that count as an ack or not? If yes I think we should land this
patch right away, since it's going to conflict real fast badly.
I had some follow up discussion with Jason and I would rather like to
switch to using rcu_dereference_check() in all places and completely
remove the _rcu postfix.
Hm, I'm not sure whether spreading _rcu tricks further is an
especially bright idea. At least i915 is full of very clever _rcu
tricks, and encouraging drivers to roll out their own _rcu everywhere
is probably not in our best interest. Some fast-path checking is imo
ok, but that's it. Especially once we get into the entire
SLAB_TYPESAFE_BY_RCU business it becomes really nasty really quickly.

Oh, yes completely agree. SLAB_TYPESAFE_BY_RCU is optimizing for the wrong use case I think.

You save a bit of overhead while freeing fences, but in return you have extra overhead while adding fences to the dma_resv object.

That's why I'm slightly leaning towards _unlocked variants, except we
do use those in lots of places where we hold dma_resv_lock too. So not
sure what's the best plan overall here.

Well what function names are we actually talking about?

For the dma_resv_get_excl_rcu() case I agree we should probably name that to dma_resv_get_excl_unlocked() because it makes no sense at all to use this function while holding the lock.

But for the following functions:
dma_resv_get_fences_rcu
dma_resv_wait_timeout_rcu
dma_resv_test_signaled_rcu

I think we should just drop the _rcu naming because those are supposed to work independent if the resv lock is held or not.

Regards,
Christian.

-Daniel

But yes I see the pain of rebasing this as well.

Christian.

-Daniel

Christian.

v2 (Jason Ekstrand):
    - Fix function argument indentation

Signed-off-by: Jason Ekstrand <jason@xxxxxxxxxxxxxx>
Suggested-by: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Christian König <christian.koenig@xxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Maxime Ripard <mripard@xxxxxxxxxx>
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: Lucas Stach <l.stach@xxxxxxxxxxxxxx>
Cc: Rob Clark <robdclark@xxxxxxxxx>
Cc: Sean Paul <sean@xxxxxxxxxx>
Cc: Huang Rui <ray.huang@xxxxxxx>
Cc: Gerd Hoffmann <kraxel@xxxxxxxxxx>
Cc: VMware Graphics <linux-graphics-maintainer@xxxxxxxxxx>
---
    drivers/dma-buf/dma-buf.c                     |  4 +--
    drivers/dma-buf/dma-resv.c                    | 28 +++++++++----------
    drivers/gpu/drm/amd/amdgpu/amdgpu_display.c   |  6 ++--
    drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c   |  2 +-
    drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c       |  4 +--
    drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c       |  6 ++--
    drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c        |  4 +--
    drivers/gpu/drm/amd/amdgpu/amdgpu_object.c    |  4 +--
    drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c       |  6 ++--
    drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c        | 14 +++++-----
    .../gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c |  6 ++--
    drivers/gpu/drm/drm_gem.c                     | 10 +++----
    drivers/gpu/drm/drm_gem_atomic_helper.c       |  2 +-
    drivers/gpu/drm/etnaviv/etnaviv_gem.c         |  7 ++---
    drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c  |  8 +++---
    drivers/gpu/drm/i915/display/intel_display.c  |  2 +-
    drivers/gpu/drm/i915/dma_resv_utils.c         |  2 +-
    drivers/gpu/drm/i915/gem/i915_gem_busy.c      |  2 +-
    .../gpu/drm/i915/gem/i915_gem_execbuffer.c    |  2 +-
    drivers/gpu/drm/i915/gem/i915_gem_object.h    |  2 +-
    drivers/gpu/drm/i915/gem/i915_gem_userptr.c   |  4 +--
    drivers/gpu/drm/i915/gem/i915_gem_wait.c      | 10 +++----
    drivers/gpu/drm/i915/i915_request.c           |  6 ++--
    drivers/gpu/drm/i915/i915_sw_fence.c          |  4 +--
    drivers/gpu/drm/msm/msm_gem.c                 |  3 +-
    drivers/gpu/drm/nouveau/dispnv50/wndw.c       |  2 +-
    drivers/gpu/drm/nouveau/nouveau_gem.c         |  4 +--
    drivers/gpu/drm/panfrost/panfrost_drv.c       |  4 +--
    drivers/gpu/drm/panfrost/panfrost_job.c       |  2 +-
    drivers/gpu/drm/radeon/radeon_gem.c           |  6 ++--
    drivers/gpu/drm/radeon/radeon_mn.c            |  4 +--
    drivers/gpu/drm/ttm/ttm_bo.c                  | 18 ++++++------
    drivers/gpu/drm/vgem/vgem_fence.c             |  4 +--
    drivers/gpu/drm/virtio/virtgpu_ioctl.c        |  6 ++--
    drivers/gpu/drm/vmwgfx/vmwgfx_bo.c            |  2 +-
    include/linux/dma-resv.h                      | 18 ++++++------
    36 files changed, 108 insertions(+), 110 deletions(-)

diff --git a/drivers/dma-buf/dma-buf.c b/drivers/dma-buf/dma-buf.c
index f264b70c383eb..ed6451d55d663 100644
--- a/drivers/dma-buf/dma-buf.c
+++ b/drivers/dma-buf/dma-buf.c
@@ -1147,8 +1147,8 @@ static int __dma_buf_begin_cpu_access(struct dma_buf *dmabuf,
     long ret;
     /* Wait on any implicit rendering fences */
-   ret = dma_resv_wait_timeout_rcu(resv, write, true,
-                                             MAX_SCHEDULE_TIMEOUT);
+   ret = dma_resv_wait_timeout_unlocked(resv, write, true,
+                                        MAX_SCHEDULE_TIMEOUT);
     if (ret < 0)
             return ret;
diff --git a/drivers/dma-buf/dma-resv.c b/drivers/dma-buf/dma-resv.c
index 6ddbeb5dfbf65..d6f1ed4cd4d55 100644
--- a/drivers/dma-buf/dma-resv.c
+++ b/drivers/dma-buf/dma-resv.c
@@ -417,7 +417,7 @@ int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src)
    EXPORT_SYMBOL(dma_resv_copy_fences);
    /**
- * dma_resv_get_fences_rcu - Get an object's shared and exclusive
+ * dma_resv_get_fences_unlocked - Get an object's shared and exclusive
     * fences without update side lock held
     * @obj: the reservation object
     * @pfence_excl: the returned exclusive fence (or NULL)
@@ -429,10 +429,10 @@ EXPORT_SYMBOL(dma_resv_copy_fences);
     * exclusive fence is not specified the fence is put into the array of the
     * shared fences as well. Returns either zero or -ENOMEM.
     */
-int dma_resv_get_fences_rcu(struct dma_resv *obj,
-                       struct dma_fence **pfence_excl,
-                       unsigned *pshared_count,
-                       struct dma_fence ***pshared)
+int dma_resv_get_fences_unlocked(struct dma_resv *obj,
+                            struct dma_fence **pfence_excl,
+                            unsigned *pshared_count,
+                            struct dma_fence ***pshared)
    {
     struct dma_fence **shared = NULL;
     struct dma_fence *fence_excl;
@@ -515,10 +515,10 @@ int dma_resv_get_fences_rcu(struct dma_resv *obj,
     *pshared = shared;
     return ret;
    }
-EXPORT_SYMBOL_GPL(dma_resv_get_fences_rcu);
+EXPORT_SYMBOL_GPL(dma_resv_get_fences_unlocked);
    /**
- * dma_resv_wait_timeout_rcu - Wait on reservation's objects
+ * dma_resv_wait_timeout_unlocked - Wait on reservation's objects
     * shared and/or exclusive fences.
     * @obj: the reservation object
     * @wait_all: if true, wait on all fences, else wait on just exclusive fence
@@ -529,9 +529,9 @@ EXPORT_SYMBOL_GPL(dma_resv_get_fences_rcu);
     * Returns -ERESTARTSYS if interrupted, 0 if the wait timed out, or
     * greater than zer on success.
     */
-long dma_resv_wait_timeout_rcu(struct dma_resv *obj,
-                          bool wait_all, bool intr,
-                          unsigned long timeout)
+long dma_resv_wait_timeout_unlocked(struct dma_resv *obj,
+                               bool wait_all, bool intr,
+                               unsigned long timeout)
    {
     struct dma_fence *fence;
     unsigned seq, shared_count;
@@ -602,7 +602,7 @@ long dma_resv_wait_timeout_rcu(struct dma_resv *obj,
     rcu_read_unlock();
     goto retry;
    }
-EXPORT_SYMBOL_GPL(dma_resv_wait_timeout_rcu);
+EXPORT_SYMBOL_GPL(dma_resv_wait_timeout_unlocked);
    static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
@@ -622,7 +622,7 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
    }
    /**
- * dma_resv_test_signaled_rcu - Test if a reservation object's
+ * dma_resv_test_signaled_unlocked - Test if a reservation object's
     * fences have been signaled.
     * @obj: the reservation object
     * @test_all: if true, test all fences, otherwise only test the exclusive
@@ -631,7 +631,7 @@ static inline int dma_resv_test_signaled_single(struct dma_fence *passed_fence)
     * RETURNS
     * true if all fences signaled, else false
     */
-bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
+bool dma_resv_test_signaled_unlocked(struct dma_resv *obj, bool test_all)
    {
     unsigned seq, shared_count;
     int ret;
@@ -680,4 +680,4 @@ bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all)
     rcu_read_unlock();
     return ret;
    }
-EXPORT_SYMBOL_GPL(dma_resv_test_signaled_rcu);
+EXPORT_SYMBOL_GPL(dma_resv_test_signaled_unlocked);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
index 8a1fb8b6606e5..b8e24f199be9a 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_display.c
@@ -203,9 +203,9 @@ int amdgpu_display_crtc_page_flip_target(struct drm_crtc *crtc,
             goto unpin;
     }
-   r = dma_resv_get_fences_rcu(new_abo->tbo.base.resv, &work->excl,
-                                         &work->shared_count,
-                                         &work->shared);
+   r = dma_resv_get_fences_unlocked(new_abo->tbo.base.resv, &work->excl,
+                                    &work->shared_count,
+                                    &work->shared);
     if (unlikely(r != 0)) {
             DRM_ERROR("failed to get fences for buffer\n");
             goto unpin;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
index baa980a477d94..0d0319bc51577 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_dma_buf.c
@@ -98,7 +98,7 @@ __dma_resv_make_exclusive(struct dma_resv *obj)
     if (!dma_resv_get_list(obj)) /* no shared fences to convert */
             return 0;
-   r = dma_resv_get_fences_rcu(obj, NULL, &count, &fences);
+   r = dma_resv_get_fences_unlocked(obj, NULL, &count, &fences);
     if (r)
             return r;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
index 18974bd081f00..8e2996d6ba3ad 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_gem.c
@@ -471,8 +471,8 @@ int amdgpu_gem_wait_idle_ioctl(struct drm_device *dev, void *data,
             return -ENOENT;
     }
     robj = gem_to_amdgpu_bo(gobj);
-   ret = dma_resv_wait_timeout_rcu(robj->tbo.base.resv, true, true,
-                                             timeout);
+   ret = dma_resv_wait_timeout_unlocked(robj->tbo.base.resv, true, true,
+                                        timeout);
     /* ret == 0 means not signaled,
      * ret > 0 means signaled
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
index b4971e90b98cf..38e1b32dd2cef 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ids.c
@@ -112,7 +112,7 @@ void amdgpu_pasid_free_delayed(struct dma_resv *resv,
     unsigned count;
     int r;
-   r = dma_resv_get_fences_rcu(resv, NULL, &count, &fences);
+   r = dma_resv_get_fences_unlocked(resv, NULL, &count, &fences);
     if (r)
             goto fallback;
@@ -156,8 +156,8 @@ void amdgpu_pasid_free_delayed(struct dma_resv *resv,
     /* Not enough memory for the delayed delete, as last resort
      * block for all the fences to complete.
      */
-   dma_resv_wait_timeout_rcu(resv, true, false,
-                                       MAX_SCHEDULE_TIMEOUT);
+   dma_resv_wait_timeout_unlocked(resv, true, false,
+                                  MAX_SCHEDULE_TIMEOUT);
     amdgpu_pasid_free(pasid);
    }
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
index 828b5167ff128..0319c8b547c48 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_mn.c
@@ -75,8 +75,8 @@ static bool amdgpu_mn_invalidate_gfx(struct mmu_interval_notifier *mni,
     mmu_interval_set_seq(mni, cur_seq);
-   r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
-                                 MAX_SCHEDULE_TIMEOUT);
+   r = dma_resv_wait_timeout_unlocked(bo->tbo.base.resv, true, false,
+                                      MAX_SCHEDULE_TIMEOUT);
     mutex_unlock(&adev->notifier_lock);
     if (r <= 0)
             DRM_ERROR("(%ld) failed to wait for user bo\n", r);
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
index 0adffcace3263..de1c7c5501683 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_object.c
@@ -791,8 +791,8 @@ int amdgpu_bo_kmap(struct amdgpu_bo *bo, void **ptr)
             return 0;
     }
-   r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, false, false,
-                                           MAX_SCHEDULE_TIMEOUT);
+   r = dma_resv_wait_timeout_unlocked(bo->tbo.base.resv, false, false,
+                                      MAX_SCHEDULE_TIMEOUT);
     if (r < 0)
             return r;
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c
index c6dbc08016045..4a2196404fb69 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_uvd.c
@@ -1115,9 +1115,9 @@ static int amdgpu_uvd_send_msg(struct amdgpu_ring *ring, struct amdgpu_bo *bo,
     ib->length_dw = 16;
     if (direct) {
-           r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv,
-                                                   true, false,
-                                                   msecs_to_jiffies(10));
+           r = dma_resv_wait_timeout_unlocked(bo->tbo.base.resv,
+                                              true, false,
+                                              msecs_to_jiffies(10));
             if (r == 0)
                     r = -ETIMEDOUT;
             if (r < 0)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
index 4a3e3f72e1277..7ba1c537d6584 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vm.c
@@ -2007,14 +2007,14 @@ static void amdgpu_vm_prt_fini(struct amdgpu_device *adev, struct amdgpu_vm *vm)
     unsigned i, shared_count;
     int r;
-   r = dma_resv_get_fences_rcu(resv, &excl,
-                                         &shared_count, &shared);
+   r = dma_resv_get_fences_unlocked(resv, &excl,
+                                    &shared_count, &shared);
     if (r) {
             /* Not enough memory to grab the fence list, as last resort
              * block for all the fences to complete.
              */
-           dma_resv_wait_timeout_rcu(resv, true, false,
-                                               MAX_SCHEDULE_TIMEOUT);
+           dma_resv_wait_timeout_unlocked(resv, true, false,
+                                          MAX_SCHEDULE_TIMEOUT);
             return;
     }
@@ -2625,7 +2625,7 @@ bool amdgpu_vm_evictable(struct amdgpu_bo *bo)
             return true;
     /* Don't evict VM page tables while they are busy */
-   if (!dma_resv_test_signaled_rcu(bo->tbo.base.resv, true))
+   if (!dma_resv_test_signaled_unlocked(bo->tbo.base.resv, true))
             return false;
     /* Try to block ongoing updates */
@@ -2805,8 +2805,8 @@ void amdgpu_vm_adjust_size(struct amdgpu_device *adev, uint32_t min_vm_size,
     */
    long amdgpu_vm_wait_idle(struct amdgpu_vm *vm, long timeout)
    {
-   timeout = dma_resv_wait_timeout_rcu(vm->root.base.bo->tbo.base.resv,
-                                       true, true, timeout);
+   timeout = dma_resv_wait_timeout_unlocked(vm->root.base.bo->tbo.base.resv,
+                                            true, true, timeout);
     if (timeout <= 0)
             return timeout;
diff --git a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
index 9ca517b658546..0121d2817fa26 100644
--- a/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
+++ b/drivers/gpu/drm/amd/display/amdgpu_dm/amdgpu_dm.c
@@ -8276,9 +8276,9 @@ static void amdgpu_dm_commit_planes(struct drm_atomic_state *state,
              * deadlock during GPU reset when this fence will not signal
              * but we hold reservation lock for the BO.
              */
-           r = dma_resv_wait_timeout_rcu(abo->tbo.base.resv, true,
-                                                   false,
-                                                   msecs_to_jiffies(5000));
+           r = dma_resv_wait_timeout_unlocked(abo->tbo.base.resv, true,
+                                              false,
+                                              msecs_to_jiffies(5000));
             if (unlikely(r <= 0))
                     DRM_ERROR("Waiting for fences timed out!");
diff --git a/drivers/gpu/drm/drm_gem.c b/drivers/gpu/drm/drm_gem.c
index 9989425e9875a..1241a421b9e81 100644
--- a/drivers/gpu/drm/drm_gem.c
+++ b/drivers/gpu/drm/drm_gem.c
@@ -770,8 +770,8 @@ long drm_gem_dma_resv_wait(struct drm_file *filep, u32 handle,
             return -EINVAL;
     }
-   ret = dma_resv_wait_timeout_rcu(obj->resv, wait_all,
-                                             true, timeout);
+   ret = dma_resv_wait_timeout_unlocked(obj->resv, wait_all,
+                                        true, timeout);
     if (ret == 0)
             ret = -ETIME;
     else if (ret > 0)
@@ -1375,13 +1375,13 @@ int drm_gem_fence_array_add_implicit(struct xarray *fence_array,
     if (!write) {
             struct dma_fence *fence =
-                   dma_resv_get_excl_rcu(obj->resv);
+                   dma_resv_get_excl_unlocked(obj->resv);
             return drm_gem_fence_array_add(fence_array, fence);
     }
-   ret = dma_resv_get_fences_rcu(obj->resv, NULL,
-                                           &fence_count, &fences);
+   ret = dma_resv_get_fences_unlocked(obj->resv, NULL,
+                                      &fence_count, &fences);
     if (ret || !fence_count)
             return ret;
diff --git a/drivers/gpu/drm/drm_gem_atomic_helper.c b/drivers/gpu/drm/drm_gem_atomic_helper.c
index a005c5a0ba46a..a27135084ae5c 100644
--- a/drivers/gpu/drm/drm_gem_atomic_helper.c
+++ b/drivers/gpu/drm/drm_gem_atomic_helper.c
@@ -147,7 +147,7 @@ int drm_gem_plane_helper_prepare_fb(struct drm_plane *plane, struct drm_plane_st
             return 0;
     obj = drm_gem_fb_get_obj(state->fb, 0);
-   fence = dma_resv_get_excl_rcu(obj->resv);
+   fence = dma_resv_get_excl_unlocked(obj->resv);
     drm_atomic_set_fence_for_plane(state, fence);
     return 0;
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem.c b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
index db69f19ab5bca..4e6f5346e84e4 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem.c
@@ -390,14 +390,13 @@ int etnaviv_gem_cpu_prep(struct drm_gem_object *obj, u32 op,
     }
     if (op & ETNA_PREP_NOSYNC) {
-           if (!dma_resv_test_signaled_rcu(obj->resv,
-                                                     write))
+           if (!dma_resv_test_signaled_unlocked(obj->resv, write))
                     return -EBUSY;
     } else {
             unsigned long remain = etnaviv_timeout_to_jiffies(timeout);
-           ret = dma_resv_wait_timeout_rcu(obj->resv,
-                                                     write, true, remain);
+           ret = dma_resv_wait_timeout_unlocked(obj->resv,
+                                                write, true, remain);
             if (ret <= 0)
                     return ret == 0 ? -ETIMEDOUT : ret;
     }
diff --git a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
index d05c359945799..6617fada4595d 100644
--- a/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
+++ b/drivers/gpu/drm/etnaviv/etnaviv_gem_submit.c
@@ -189,13 +189,13 @@ static int submit_fence_sync(struct etnaviv_gem_submit *submit)
                     continue;
             if (bo->flags & ETNA_SUBMIT_BO_WRITE) {
-                   ret = dma_resv_get_fences_rcu(robj, &bo->excl,
-                                                           &bo->nr_shared,
-                                                           &bo->shared);
+                   ret = dma_resv_get_fences_unlocked(robj, &bo->excl,
+                                                      &bo->nr_shared,
+                                                      &bo->shared);
                     if (ret)
                             return ret;
             } else {
-                   bo->excl = dma_resv_get_excl_rcu(robj);
+                   bo->excl = dma_resv_get_excl_unlocked(robj);
             }
     }
diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
index 422b59ebf6dce..5f0b85a102159 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -11040,7 +11040,7 @@ intel_prepare_plane_fb(struct drm_plane *_plane,
             if (ret < 0)
                     goto unpin_fb;
-           fence = dma_resv_get_excl_rcu(obj->base.resv);
+           fence = dma_resv_get_excl_unlocked(obj->base.resv);
             if (fence) {
                     add_rps_boost_after_vblank(new_plane_state->hw.crtc,
                                                fence);
diff --git a/drivers/gpu/drm/i915/dma_resv_utils.c b/drivers/gpu/drm/i915/dma_resv_utils.c
index 9e508e7d4629f..bdfc6bf16a4e9 100644
--- a/drivers/gpu/drm/i915/dma_resv_utils.c
+++ b/drivers/gpu/drm/i915/dma_resv_utils.c
@@ -10,7 +10,7 @@
    void dma_resv_prune(struct dma_resv *resv)
    {
     if (dma_resv_trylock(resv)) {
-           if (dma_resv_test_signaled_rcu(resv, true))
+           if (dma_resv_test_signaled_unlocked(resv, true))
                     dma_resv_add_excl_fence(resv, NULL);
             dma_resv_unlock(resv);
     }
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_busy.c b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
index 25235ef630c10..754ad6d1bace9 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_busy.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_busy.c
@@ -105,7 +105,7 @@ i915_gem_busy_ioctl(struct drm_device *dev, void *data,
      * Alternatively, we can trade that extra information on read/write
      * activity with
      *      args->busy =
-    *              !dma_resv_test_signaled_rcu(obj->resv, true);
+    *              !dma_resv_test_signaled_unlocked(obj->resv, true);
      * to report the overall busyness. This is what the wait-ioctl does.
      *
      */
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 297143511f99b..e8f323564e57b 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -1481,7 +1481,7 @@ static inline bool use_reloc_gpu(struct i915_vma *vma)
     if (DBG_FORCE_RELOC)
             return false;
-   return !dma_resv_test_signaled_rcu(vma->resv, true);
+   return !dma_resv_test_signaled_unlocked(vma->resv, true);
    }
    static unsigned long vma_phys_addr(struct i915_vma *vma, u32 offset)
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_object.h b/drivers/gpu/drm/i915/gem/i915_gem_object.h
index 2ebd79537aea9..7c0eb425cb3b3 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_object.h
+++ b/drivers/gpu/drm/i915/gem/i915_gem_object.h
@@ -500,7 +500,7 @@ i915_gem_object_last_write_engine(struct drm_i915_gem_object *obj)
     struct dma_fence *fence;
     rcu_read_lock();
-   fence = dma_resv_get_excl_rcu(obj->base.resv);
+   fence = dma_resv_get_excl_unlocked(obj->base.resv);
     rcu_read_unlock();
     if (fence && dma_fence_is_i915(fence) && !dma_fence_is_signaled(fence))
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
index a657b99ec7606..44df18dc9669f 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_userptr.c
@@ -85,8 +85,8 @@ static bool i915_gem_userptr_invalidate(struct mmu_interval_notifier *mni,
             return true;
     /* we will unbind on next submission, still have userptr pins */
-   r = dma_resv_wait_timeout_rcu(obj->base.resv, true, false,
-                                 MAX_SCHEDULE_TIMEOUT);
+   r = dma_resv_wait_timeout_unlocked(obj->base.resv, true, false,
+                                      MAX_SCHEDULE_TIMEOUT);
     if (r <= 0)
             drm_err(&i915->drm, "(%ld) failed to wait for idle\n", r);
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_wait.c b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
index 4b9856d5ba14f..5b6c52659ad4d 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_wait.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_wait.c
@@ -45,7 +45,7 @@ i915_gem_object_wait_reservation(struct dma_resv *resv,
             unsigned int count, i;
             int ret;
-           ret = dma_resv_get_fences_rcu(resv, &excl, &count, &shared);
+           ret = dma_resv_get_fences_unlocked(resv, &excl, &count, &shared);
             if (ret)
                     return ret;
@@ -73,7 +73,7 @@ i915_gem_object_wait_reservation(struct dma_resv *resv,
              */
             prune_fences = count && timeout >= 0;
     } else {
-           excl = dma_resv_get_excl_rcu(resv);
+           excl = dma_resv_get_excl_unlocked(resv);
     }
     if (excl && timeout >= 0)
@@ -158,8 +158,8 @@ i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
             unsigned int count, i;
             int ret;
-           ret = dma_resv_get_fences_rcu(obj->base.resv,
-                                         &excl, &count, &shared);
+           ret = dma_resv_get_fences_unlocked(obj->base.resv,
+                                              &excl, &count, &shared);
             if (ret)
                     return ret;
@@ -170,7 +170,7 @@ i915_gem_object_wait_priority(struct drm_i915_gem_object *obj,
             kfree(shared);
     } else {
-           excl = dma_resv_get_excl_rcu(obj->base.resv);
+           excl = dma_resv_get_excl_unlocked(obj->base.resv);
     }
     if (excl) {
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index 970d8f4986bbe..f1ed03ced7dd1 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -1594,8 +1594,8 @@ i915_request_await_object(struct i915_request *to,
             struct dma_fence **shared;
             unsigned int count, i;
-           ret = dma_resv_get_fences_rcu(obj->base.resv,
-                                                   &excl, &count, &shared);
+           ret = dma_resv_get_fences_unlocked(obj->base.resv,
+                                              &excl, &count, &shared);
             if (ret)
                     return ret;
@@ -1611,7 +1611,7 @@ i915_request_await_object(struct i915_request *to,
                     dma_fence_put(shared[i]);
             kfree(shared);
     } else {
-           excl = dma_resv_get_excl_rcu(obj->base.resv);
+           excl = dma_resv_get_excl_unlocked(obj->base.resv);
     }
     if (excl) {
diff --git a/drivers/gpu/drm/i915/i915_sw_fence.c b/drivers/gpu/drm/i915/i915_sw_fence.c
index 2744558f30507..0bcb7ea44201e 100644
--- a/drivers/gpu/drm/i915/i915_sw_fence.c
+++ b/drivers/gpu/drm/i915/i915_sw_fence.c
@@ -582,7 +582,7 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
             struct dma_fence **shared;
             unsigned int count, i;
-           ret = dma_resv_get_fences_rcu(resv, &excl, &count, &shared);
+           ret = dma_resv_get_fences_unlocked(resv, &excl, &count, &shared);
             if (ret)
                     return ret;
@@ -606,7 +606,7 @@ int i915_sw_fence_await_reservation(struct i915_sw_fence *fence,
                     dma_fence_put(shared[i]);
             kfree(shared);
     } else {
-           excl = dma_resv_get_excl_rcu(resv);
+           excl = dma_resv_get_excl_unlocked(resv);
     }
     if (ret >= 0 && excl && excl->ops != exclude) {
diff --git a/drivers/gpu/drm/msm/msm_gem.c b/drivers/gpu/drm/msm/msm_gem.c
index 56df86e5f7400..1aca60507bb14 100644
--- a/drivers/gpu/drm/msm/msm_gem.c
+++ b/drivers/gpu/drm/msm/msm_gem.c
@@ -915,8 +915,7 @@ int msm_gem_cpu_prep(struct drm_gem_object *obj, uint32_t op, ktime_t *timeout)
             op & MSM_PREP_NOSYNC ? 0 : timeout_to_jiffies(timeout);
     long ret;
-   ret = dma_resv_wait_timeout_rcu(obj->resv, write,
-                                             true,  remain);
+   ret = dma_resv_wait_timeout_unlocked(obj->resv, write, true, remain);
     if (ret == 0)
             return remain == 0 ? -EBUSY : -ETIMEDOUT;
     else if (ret < 0)
diff --git a/drivers/gpu/drm/nouveau/dispnv50/wndw.c b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
index 0cb1f9d848d3e..8d048bacd6f02 100644
--- a/drivers/gpu/drm/nouveau/dispnv50/wndw.c
+++ b/drivers/gpu/drm/nouveau/dispnv50/wndw.c
@@ -561,7 +561,7 @@ nv50_wndw_prepare_fb(struct drm_plane *plane, struct drm_plane_state *state)
                     asyw->image.handle[0] = ctxdma->object.handle;
     }
-   asyw->state.fence = dma_resv_get_excl_rcu(nvbo->bo.base.resv);
+   asyw->state.fence = dma_resv_get_excl_unlocked(nvbo->bo.base.resv);
     asyw->image.offset[0] = nvbo->offset;
     if (wndw->func->prepare) {
diff --git a/drivers/gpu/drm/nouveau/nouveau_gem.c b/drivers/gpu/drm/nouveau/nouveau_gem.c
index a70e82413fa75..bc6b09ee9b552 100644
--- a/drivers/gpu/drm/nouveau/nouveau_gem.c
+++ b/drivers/gpu/drm/nouveau/nouveau_gem.c
@@ -928,8 +928,8 @@ nouveau_gem_ioctl_cpu_prep(struct drm_device *dev, void *data,
             return -ENOENT;
     nvbo = nouveau_gem_object(gem);
-   lret = dma_resv_wait_timeout_rcu(nvbo->bo.base.resv, write, true,
-                                              no_wait ? 0 : 30 * HZ);
+   lret = dma_resv_wait_timeout_unlocked(nvbo->bo.base.resv, write, true,
+                                         no_wait ? 0 : 30 * HZ);
     if (!lret)
             ret = -EBUSY;
     else if (lret > 0)
diff --git a/drivers/gpu/drm/panfrost/panfrost_drv.c b/drivers/gpu/drm/panfrost/panfrost_drv.c
index ca07098a61419..eef5b632ee0ce 100644
--- a/drivers/gpu/drm/panfrost/panfrost_drv.c
+++ b/drivers/gpu/drm/panfrost/panfrost_drv.c
@@ -311,8 +311,8 @@ panfrost_ioctl_wait_bo(struct drm_device *dev, void *data,
     if (!gem_obj)
             return -ENOENT;
-   ret = dma_resv_wait_timeout_rcu(gem_obj->resv, true,
-                                             true, timeout);
+   ret = dma_resv_wait_timeout_unlocked(gem_obj->resv, true,
+                                        true, timeout);
     if (!ret)
             ret = timeout ? -ETIMEDOUT : -EBUSY;
diff --git a/drivers/gpu/drm/panfrost/panfrost_job.c b/drivers/gpu/drm/panfrost/panfrost_job.c
index 6003cfeb13221..2df3e999a38d0 100644
--- a/drivers/gpu/drm/panfrost/panfrost_job.c
+++ b/drivers/gpu/drm/panfrost/panfrost_job.c
@@ -203,7 +203,7 @@ static void panfrost_acquire_object_fences(struct drm_gem_object **bos,
     int i;
     for (i = 0; i < bo_count; i++)
-           implicit_fences[i] = dma_resv_get_excl_rcu(bos[i]->resv);
+           implicit_fences[i] = dma_resv_get_excl_unlocked(bos[i]->resv);
    }
    static void panfrost_attach_object_fences(struct drm_gem_object **bos,
diff --git a/drivers/gpu/drm/radeon/radeon_gem.c b/drivers/gpu/drm/radeon/radeon_gem.c
index 05ea2f39f6261..1a38b0bf36d11 100644
--- a/drivers/gpu/drm/radeon/radeon_gem.c
+++ b/drivers/gpu/drm/radeon/radeon_gem.c
@@ -125,7 +125,7 @@ static int radeon_gem_set_domain(struct drm_gem_object *gobj,
     }
     if (domain == RADEON_GEM_DOMAIN_CPU) {
             /* Asking for cpu access wait for object idle */
-           r = dma_resv_wait_timeout_rcu(robj->tbo.base.resv, true, true, 30 * HZ);
+           r = dma_resv_wait_timeout_unlocked(robj->tbo.base.resv, true, true, 30 * HZ);
             if (!r)
                     r = -EBUSY;
@@ -474,7 +474,7 @@ int radeon_gem_busy_ioctl(struct drm_device *dev, void *data,
     }
     robj = gem_to_radeon_bo(gobj);
-   r = dma_resv_test_signaled_rcu(robj->tbo.base.resv, true);
+   r = dma_resv_test_signaled_unlocked(robj->tbo.base.resv, true);
     if (r == 0)
             r = -EBUSY;
     else
@@ -503,7 +503,7 @@ int radeon_gem_wait_idle_ioctl(struct drm_device *dev, void *data,
     }
     robj = gem_to_radeon_bo(gobj);
-   ret = dma_resv_wait_timeout_rcu(robj->tbo.base.resv, true, true, 30 * HZ);
+   ret = dma_resv_wait_timeout_unlocked(robj->tbo.base.resv, true, true, 30 * HZ);
     if (ret == 0)
             r = -EBUSY;
     else if (ret < 0)
diff --git a/drivers/gpu/drm/radeon/radeon_mn.c b/drivers/gpu/drm/radeon/radeon_mn.c
index e37c9a57a7c36..a19be3f8a218c 100644
--- a/drivers/gpu/drm/radeon/radeon_mn.c
+++ b/drivers/gpu/drm/radeon/radeon_mn.c
@@ -66,8 +66,8 @@ static bool radeon_mn_invalidate(struct mmu_interval_notifier *mn,
             return true;
     }
-   r = dma_resv_wait_timeout_rcu(bo->tbo.base.resv, true, false,
-                                 MAX_SCHEDULE_TIMEOUT);
+   r = dma_resv_wait_timeout_unlocked(bo->tbo.base.resv, true, false,
+                                      MAX_SCHEDULE_TIMEOUT);
     if (r <= 0)
             DRM_ERROR("(%ld) failed to wait for user bo\n", r);
diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index ca1b098b6a561..215cad3149621 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -294,7 +294,7 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
     struct dma_resv *resv = &bo->base._resv;
     int ret;
-   if (dma_resv_test_signaled_rcu(resv, true))
+   if (dma_resv_test_signaled_unlocked(resv, true))
             ret = 0;
     else
             ret = -EBUSY;
@@ -306,8 +306,8 @@ static int ttm_bo_cleanup_refs(struct ttm_buffer_object *bo,
                     dma_resv_unlock(bo->base.resv);
             spin_unlock(&bo->bdev->lru_lock);
-           lret = dma_resv_wait_timeout_rcu(resv, true, interruptible,
-                                            30 * HZ);
+           lret = dma_resv_wait_timeout_unlocked(resv, true, interruptible,
+                                                 30 * HZ);
             if (lret < 0)
                     return lret;
@@ -409,8 +409,8 @@ static void ttm_bo_release(struct kref *kref)
                     /* Last resort, if we fail to allocate memory for the
                      * fences block for the BO to become idle
                      */
-                   dma_resv_wait_timeout_rcu(bo->base.resv, true, false,
-                                             30 * HZ);
+                   dma_resv_wait_timeout_unlocked(bo->base.resv, true, false,
+                                                  30 * HZ);
             }
             if (bo->bdev->funcs->release_notify)
@@ -420,7 +420,7 @@ static void ttm_bo_release(struct kref *kref)
             ttm_mem_io_free(bdev, &bo->mem);
     }
-   if (!dma_resv_test_signaled_rcu(bo->base.resv, true) ||
+   if (!dma_resv_test_signaled_unlocked(bo->base.resv, true) ||
         !dma_resv_trylock(bo->base.resv)) {
             /* The BO is not idle, resurrect it for delayed destroy */
             ttm_bo_flush_all_fences(bo);
@@ -1116,14 +1116,14 @@ int ttm_bo_wait(struct ttm_buffer_object *bo,
     long timeout = 15 * HZ;
     if (no_wait) {
-           if (dma_resv_test_signaled_rcu(bo->base.resv, true))
+           if (dma_resv_test_signaled_unlocked(bo->base.resv, true))
                     return 0;
             else
                     return -EBUSY;
     }
-   timeout = dma_resv_wait_timeout_rcu(bo->base.resv, true,
-                                                 interruptible, timeout);
+   timeout = dma_resv_wait_timeout_unlocked(bo->base.resv, true,
+                                            interruptible, timeout);
     if (timeout < 0)
             return timeout;
diff --git a/drivers/gpu/drm/vgem/vgem_fence.c b/drivers/gpu/drm/vgem/vgem_fence.c
index 2902dc6e64faf..010a82405e374 100644
--- a/drivers/gpu/drm/vgem/vgem_fence.c
+++ b/drivers/gpu/drm/vgem/vgem_fence.c
@@ -151,8 +151,8 @@ int vgem_fence_attach_ioctl(struct drm_device *dev,
     /* Check for a conflicting fence */
     resv = obj->resv;
-   if (!dma_resv_test_signaled_rcu(resv,
-                                             arg->flags & VGEM_FENCE_WRITE)) {
+   if (!dma_resv_test_signaled_unlocked(resv,
+                                        arg->flags & VGEM_FENCE_WRITE)) {
             ret = -EBUSY;
             goto err_fence;
     }
diff --git a/drivers/gpu/drm/virtio/virtgpu_ioctl.c b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
index 669f2ee395154..ab010c8e32816 100644
--- a/drivers/gpu/drm/virtio/virtgpu_ioctl.c
+++ b/drivers/gpu/drm/virtio/virtgpu_ioctl.c
@@ -451,10 +451,10 @@ static int virtio_gpu_wait_ioctl(struct drm_device *dev, void *data,
             return -ENOENT;
     if (args->flags & VIRTGPU_WAIT_NOWAIT) {
-           ret = dma_resv_test_signaled_rcu(obj->resv, true);
+           ret = dma_resv_test_signaled_unlocked(obj->resv, true);
     } else {
-           ret = dma_resv_wait_timeout_rcu(obj->resv, true, true,
-                                           timeout);
+           ret = dma_resv_wait_timeout_unlocked(obj->resv, true, true,
+                                                timeout);
     }
     if (ret == 0)
             ret = -EBUSY;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
index 04dd49c4c2572..19e1ce23842a9 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_bo.c
@@ -743,7 +743,7 @@ static int vmw_user_bo_synccpu_grab(struct vmw_user_buffer_object *user_bo,
     if (flags & drm_vmw_synccpu_allow_cs) {
             long lret;
-           lret = dma_resv_wait_timeout_rcu
+           lret = dma_resv_wait_timeout_unlocked
                     (bo->base.resv, true, true,
                      nonblock ? 0 : MAX_SCHEDULE_TIMEOUT);
             if (!lret)
diff --git a/include/linux/dma-resv.h b/include/linux/dma-resv.h
index d44a77e8a7e34..99cfb7af966b8 100644
--- a/include/linux/dma-resv.h
+++ b/include/linux/dma-resv.h
@@ -246,7 +246,7 @@ dma_resv_get_excl(struct dma_resv *obj)
    }
    /**
- * dma_resv_get_excl_rcu - get the reservation object's
+ * dma_resv_get_excl_unlocked - get the reservation object's
     * exclusive fence, without lock held.
     * @obj: the reservation object
     *
@@ -257,7 +257,7 @@ dma_resv_get_excl(struct dma_resv *obj)
     * The exclusive fence or NULL if none
     */
    static inline struct dma_fence *
-dma_resv_get_excl_rcu(struct dma_resv *obj)
+dma_resv_get_excl_unlocked(struct dma_resv *obj)
    {
     struct dma_fence *fence;
@@ -278,16 +278,16 @@ void dma_resv_add_shared_fence(struct dma_resv *obj, struct dma_fence *fence);
    void dma_resv_add_excl_fence(struct dma_resv *obj, struct dma_fence *fence);
-int dma_resv_get_fences_rcu(struct dma_resv *obj,
-                       struct dma_fence **pfence_excl,
-                       unsigned *pshared_count,
-                       struct dma_fence ***pshared);
+int dma_resv_get_fences_unlocked(struct dma_resv *obj,
+                            struct dma_fence **pfence_excl,
+                            unsigned *pshared_count,
+                            struct dma_fence ***pshared);
    int dma_resv_copy_fences(struct dma_resv *dst, struct dma_resv *src);
-long dma_resv_wait_timeout_rcu(struct dma_resv *obj, bool wait_all, bool intr,
-                          unsigned long timeout);
+long dma_resv_wait_timeout_unlocked(struct dma_resv *obj, bool wait_all, bool intr,
+                               unsigned long timeout);
-bool dma_resv_test_signaled_rcu(struct dma_resv *obj, bool test_all);
+bool dma_resv_test_signaled_unlocked(struct dma_resv *obj, bool test_all);
    #endif /* _LINUX_RESERVATION_H */





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