On Thu, Oct 26, 2023 at 09:40:23AM +0000, Hogander, Jouni wrote:
> On Wed, 2023-10-25 at 17:18 +0300, Ville Syrjälä wrote:
> > On Fri, Oct 20, 2023 at 12:41:03PM +0300, Jouni Högander wrote:
> > > We are preparing for Xe driver. Xe driver doesn't have
> > > i915_sw_fence
> > > implementation. Lets drop i915_sw_fence usage from display code and
> > > use dma_fence interfaces directly.
> > >
> > > For this purpose stack dma fences from related objects into new
> > > plane
> > > state. Drm_gem_plane_helper_prepare_fb can be used for fences in
> > > new
> > > fb. Separate local implementation is used for Stacking fences from
> > > old fb
> > > into new plane state. Then wait for these stacked fences during
> > > atomic
> > > commit. There is no be need for separate GPU reset handling in
> > > intel_atomic_commit_fence_wait as the fences are signaled when GPU
> > > hang is
> > > detected and GPU is being reset.
> > >
> > > v2:
> > > - Add fences from old fb into new_plane_state->uapi.fence rather
> > > than
> > > into old_plane_state->uapi.fence
> > >
> > > Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> > > Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> > > Cc: José Roberto de Souza <jose.souza@xxxxxxxxx>
> > >
> > > Signed-off-by: Jouni Högander <jouni.hogander@xxxxxxxxx>
> > > Reviewed-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
> > > ---
> > > drivers/gpu/drm/i915/display/intel_atomic.c | 3 -
> > > .../gpu/drm/i915/display/intel_atomic_plane.c | 89 +++++++++++----
> > > ----
> > > drivers/gpu/drm/i915/display/intel_display.c | 78 ++++++---------
> > > -
> > > .../drm/i915/display/intel_display_types.h | 2 -
> > > 4 files changed, 77 insertions(+), 95 deletions(-)
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic.c
> > > b/drivers/gpu/drm/i915/display/intel_atomic.c
> > > index 5d18145da279..ec0d5168b503 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_atomic.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_atomic.c
> > > @@ -331,9 +331,6 @@ void intel_atomic_state_free(struct
> > > drm_atomic_state *_state)
> > >
> > > drm_atomic_state_default_release(&state->base);
> > > kfree(state->global_objs);
> > > -
> > > - i915_sw_fence_fini(&state->commit_ready);
> > > -
> > > kfree(state);
> > > }
> > >
> > > diff --git a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > > b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > > index b1074350616c..20fd12df6850 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_atomic_plane.c
> > > @@ -31,7 +31,10 @@
> > > * prepare/check/commit/cleanup steps.
> > > */
> > >
> > > +#include <linux/dma-fence-chain.h>
> > > +
> > > #include <drm/drm_atomic_helper.h>
> > > +#include <drm/drm_gem_atomic_helper.h>
> > > #include <drm/drm_blend.h>
> > > #include <drm/drm_fourcc.h>
> > >
> > > @@ -1012,6 +1015,44 @@ int intel_plane_check_src_coordinates(struct
> > > intel_plane_state *plane_state)
> > > return 0;
> > > }
> > >
> > > +static int add_fences(struct dma_resv *obj,
> > > + struct drm_plane_state *dst)
> >
> > I would name things differently:
> > s/obj/resv/
> > s/dst/plane_state/
> >
> > The function name should probably be a bit more
> > descriptive as well.
> >
> > > +{
> > > + struct dma_fence *fence = dma_fence_get(dst->fence);
> > > + enum dma_resv_usage usage;
> > > + struct dma_fence *new;
> > > + int ret;
> > > +
> > > + usage = fence ? DMA_RESV_USAGE_KERNEL :
> > > DMA_RESV_USAGE_WRITE;
> > > +
> > > + ret = dma_resv_get_singleton(obj, usage, &new);
> > > + if (ret)
> > > + goto error;
> > > +
> > > + if (new && fence) {
> > > + struct dma_fence_chain *chain =
> > > dma_fence_chain_alloc();
> > > +
> > > + if (!chain) {
> > > + ret = -ENOMEM;
> > > + goto error;
> > > + }
> > > +
> > > + dma_fence_chain_init(chain, fence, new, 1);
> > > + fence = &chain->base;
> > > +
> > > + } else if (new) {
> > > + fence = new;
> > > + }
> > > +
> > > + dma_fence_put(dst->fence);
> > > + dst->fence = fence;
> > > + return 0;
> > > +
> > > +error:
> > > + dma_fence_put(fence);
> > > + return ret;
> > > +}
> > > +
> > > /**
> > > * intel_prepare_plane_fb - Prepare fb for usage on plane
> > > * @_plane: drm plane to prepare for
> > > @@ -1035,7 +1076,7 @@ intel_prepare_plane_fb(struct drm_plane
> > > *_plane,
> > > struct intel_atomic_state *state =
> > > to_intel_atomic_state(new_plane_state->uapi.state);
> > > struct drm_i915_private *dev_priv = to_i915(plane-
> > > >base.dev);
> > > - const struct intel_plane_state *old_plane_state =
> > > + struct intel_plane_state *old_plane_state =
> > > intel_atomic_get_old_plane_state(state, plane);
> > > struct drm_i915_gem_object *obj =
> > > intel_fb_obj(new_plane_state->hw.fb);
> > > struct drm_i915_gem_object *old_obj =
> > > intel_fb_obj(old_plane_state->hw.fb);
> > > @@ -1057,56 +1098,30 @@ intel_prepare_plane_fb(struct drm_plane
> > > *_plane,
> > > * This should only fail upon a hung GPU, in which
> > > case we
> > > * can safely continue.
> > > */
> > > - if (new_crtc_state &&
> > > intel_crtc_needs_modeset(new_crtc_state)) {
> > > - ret =
> > > i915_sw_fence_await_reservation(&state->commit_ready,
> > > -
> > > old_obj->base.resv,
> > > -
> > > false, 0,
> > > -
> > > GFP_KERNEL);
> > > + if (new_crtc_state &&
> > > intel_crtc_needs_modeset(new_crtc_state) &&
> > > + !dma_resv_test_signaled(old_obj->base.resv,
> > > +
> > > dma_resv_usage_rw(false))) {
> >
> > Is there a specific reason for the "signaled?" test here?
>
> I will drop it. dma_resv_get_singleton will anyways provide NULL fence
> if all are signaled.
>
> >
> > > + ret = add_fences(old_obj->base.resv,
> > > &new_plane_state->uapi);
> > > if (ret < 0)
> > > return ret;
> > > }
> > > }
> > >
> > > - if (new_plane_state->uapi.fence) { /* explicit fencing */
> > > - i915_gem_fence_wait_priority(new_plane_state-
> > > >uapi.fence,
> > > - &attr);
> > > - ret = i915_sw_fence_await_dma_fence(&state-
> > > >commit_ready,
> > > -
> > > new_plane_state->uapi.fence,
> > > -
> > > i915_fence_timeout(dev_priv),
> > > - GFP_KERNEL);
> > > - if (ret < 0)
> > > - return ret;
> > > - }
> > > -
> > > if (!obj)
> > > return 0;
> > >
> > > -
> > > ret = intel_plane_pin_fb(new_plane_state);
> > > if (ret)
> > > return ret;
> > >
> > > - i915_gem_object_wait_priority(obj, 0, &attr);
> > > + ret = drm_gem_plane_helper_prepare_fb(_plane,
> > > &new_plane_state->uapi);
> >
> > I'd prefer not to consult _plane variable anywhere but the initial
> > cast.
> >
> > > + if (ret < 0)
> > > + goto unpin_fb;
> > >
> > > - if (!new_plane_state->uapi.fence) { /* implicit fencing */
> > > - struct dma_resv_iter cursor;
> > > - struct dma_fence *fence;
> > > -
> > > - ret = i915_sw_fence_await_reservation(&state-
> > > >commit_ready,
> > > - obj-
> > > >base.resv, false,
> > > -
> > > i915_fence_timeout(dev_priv),
> > > - GFP_KERNEL);
> > > - if (ret < 0)
> > > - goto unpin_fb;
> > > + if (new_plane_state->uapi.fence) {
> > > + i915_gem_fence_wait_priority(new_plane_state-
> > > >uapi.fence,
> > > + &attr);
> > >
> > > - dma_resv_iter_begin(&cursor, obj->base.resv,
> > > - DMA_RESV_USAGE_WRITE);
> > > - dma_resv_for_each_fence_unlocked(&cursor, fence) {
> > > -
> > > intel_display_rps_boost_after_vblank(new_plan
> > > e_state->hw.crtc,
> > > -
> > > fence);
> > > - }
> > > - dma_resv_iter_end(&cursor);
> > > - } else {
> > > intel_display_rps_boost_after_vblank(new_plane_stat
> > > e->hw.crtc,
> > >
> > > new_plane_state->uapi.fence);
> > > }
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> > > b/drivers/gpu/drm/i915/display/intel_display.c
> > > index 28d85e1e858e..48df0559df00 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display.c
> > > +++ b/drivers/gpu/drm/i915/display/intel_display.c
> > > @@ -48,6 +48,7 @@
> > > #include "g4x_dp.h"
> > > #include "g4x_hdmi.h"
> > > #include "hsw_ips.h"
> > > +#include "i915_config.h"
> > > #include "i915_drv.h"
> > > #include "i915_reg.h"
> > > #include "i915_utils.h"
> > > @@ -7056,29 +7057,34 @@ void
> > > intel_atomic_helper_free_state_worker(struct work_struct *work)
> > >
> > > static void intel_atomic_commit_fence_wait(struct
> > > intel_atomic_state *intel_state)
> > > {
> > > - struct wait_queue_entry wait_fence, wait_reset;
> > > - struct drm_i915_private *dev_priv = to_i915(intel_state-
> > > >base.dev);
> > > -
> > > - init_wait_entry(&wait_fence, 0);
> > > - init_wait_entry(&wait_reset, 0);
> > > - for (;;) {
> > > - prepare_to_wait(&intel_state->commit_ready.wait,
> > > - &wait_fence, TASK_UNINTERRUPTIBLE);
> > > - prepare_to_wait(bit_waitqueue(&to_gt(dev_priv)-
> > > >reset.flags,
> > > - I915_RESET_MODESET),
> > > - &wait_reset, TASK_UNINTERRUPTIBLE);
> > > + struct drm_i915_private *i915 = to_i915(intel_state-
> > > >base.dev);
> > > + struct drm_plane *plane;
> > > + struct drm_plane_state *new_plane_state, *old_plane_state;
> > > + int ret, i;
> > >
> > > + for_each_oldnew_plane_in_state(&intel_state->base, plane,
> > > + old_plane_state,
> > > new_plane_state, i) {
> > > + if (new_plane_state->fence) {
> > > + ret =
> > > dma_fence_wait_timeout(new_plane_state->fence,
> > > + false,
> > > +
> > > i915_fence_timeout(i915));
> > > + if (ret <= 0)
> > > + break;
> > >
> > > - if (i915_sw_fence_done(&intel_state->commit_ready)
> > > ||
> > > - test_bit(I915_RESET_MODESET, &to_gt(dev_priv)-
> > > >reset.flags))
> > > - break;
> > > + dma_fence_put(new_plane_state->fence);
> > > + new_plane_state->fence = NULL;
> > > + }
> > > + if (old_plane_state->fence) {
> > > + ret =
> > > dma_fence_wait_timeout(old_plane_state->fence,
> > > + false,
> > > +
> > > i915_fence_timeout(i915));
> > > + if (ret <= 0)
> > > + break;
> >
> > Why is this still here?
>
> Yeah, it isn't needed anymore. I think I can now use
> drm_atomic_helper_wait_for_fences.
I think the timeout it uses is different, so this might need some
actual thought.
> I will address this one and your
> other comments and resend.
>
> BR,
>
> Jouni Högander
> > >
> > > - schedule();
> > > + dma_fence_put(old_plane_state->fence);
> > > + old_plane_state->fence = NULL;
> > > + }
> > > }
> > > - finish_wait(&intel_state->commit_ready.wait, &wait_fence);
> > > - finish_wait(bit_waitqueue(&to_gt(dev_priv)->reset.flags,
> > > - I915_RESET_MODESET),
> > > - &wait_reset);
> > > }
> > >
> > > static void intel_atomic_cleanup_work(struct work_struct *work)
> > > @@ -7370,32 +7376,6 @@ static void intel_atomic_commit_work(struct
> > > work_struct *work)
> > > intel_atomic_commit_tail(state);
> > > }
> > >
> > > -static int
> > > -intel_atomic_commit_ready(struct i915_sw_fence *fence,
> > > - enum i915_sw_fence_notify notify)
> > > -{
> > > - struct intel_atomic_state *state =
> > > - container_of(fence, struct intel_atomic_state,
> > > commit_ready);
> > > -
> > > - switch (notify) {
> > > - case FENCE_COMPLETE:
> > > - /* we do blocking waits in the worker, nothing to
> > > do here */
> > > - break;
> > > - case FENCE_FREE:
> > > - {
> > > - struct drm_i915_private *i915 =
> > > to_i915(state->base.dev);
> > > - struct intel_atomic_helper *helper =
> > > - &i915->display.atomic_helper;
> > > -
> > > - if (llist_add(&state->freed, &helper-
> > > >free_list))
> > > - queue_work(i915->unordered_wq,
> > > &helper->free_work);
> > > - break;
> > > - }
> > > - }
> > > -
> > > - return NOTIFY_DONE;
> > > -}
> > > -
> > > static void intel_atomic_track_fbs(struct intel_atomic_state
> > > *state)
> > > {
> > > struct intel_plane_state *old_plane_state,
> > > *new_plane_state;
> > > @@ -7418,10 +7398,6 @@ int intel_atomic_commit(struct drm_device
> > > *dev, struct drm_atomic_state *_state,
> > >
> > > state->wakeref = intel_runtime_pm_get(&dev_priv-
> > > >runtime_pm);
> > >
> > > - drm_atomic_state_get(&state->base);
> > > - i915_sw_fence_init(&state->commit_ready,
> > > - intel_atomic_commit_ready);
> > > -
> > > /*
> > > * The intel_legacy_cursor_update() fast path takes care
> > > * of avoiding the vblank waits for simple cursor
> > > @@ -7454,7 +7430,6 @@ int intel_atomic_commit(struct drm_device
> > > *dev, struct drm_atomic_state *_state,
> > > if (ret) {
> > > drm_dbg_atomic(&dev_priv->drm,
> > > "Preparing state failed with %i\n",
> > > ret);
> > > - i915_sw_fence_commit(&state->commit_ready);
> > > intel_runtime_pm_put(&dev_priv->runtime_pm, state-
> > > >wakeref);
> > > return ret;
> > > }
> > > @@ -7470,8 +7445,6 @@ int intel_atomic_commit(struct drm_device
> > > *dev, struct drm_atomic_state *_state,
> > > struct intel_crtc *crtc;
> > > int i;
> > >
> > > - i915_sw_fence_commit(&state->commit_ready);
> > > -
> > > for_each_new_intel_crtc_in_state(state, crtc,
> > > new_crtc_state, i)
> > > intel_color_cleanup_commit(new_crtc_state);
> > >
> > > @@ -7485,7 +7458,6 @@ int intel_atomic_commit(struct drm_device
> > > *dev, struct drm_atomic_state *_state,
> > > drm_atomic_state_get(&state->base);
> > > INIT_WORK(&state->base.commit_work,
> > > intel_atomic_commit_work);
> > >
> > > - i915_sw_fence_commit(&state->commit_ready);
> > > if (nonblock && state->modeset) {
> > > queue_work(dev_priv->display.wq.modeset, &state-
> > > >base.commit_work);
> > > } else if (nonblock) {
> > > diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > index 65ea37fe8cff..047fe3f8905a 100644
> > > --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> > > +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> > > @@ -676,8 +676,6 @@ struct intel_atomic_state {
> > >
> > > bool rps_interactive;
> > >
> > > - struct i915_sw_fence commit_ready;
> > > -
> > > struct llist_node freed;
> > > };
> > >
> > > --
> > > 2.34.1
> >
>
--
Ville Syrjälä
Intel
