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 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
>
