On Tue, 2023-10-31 at 10:45 +0200, 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.
Thank you Ville and Maarten for checking my patch. This is now merged.
BR,
Jouni Högander
>
> v4:
> - Drop to_new_plane_state suffix from add_dma_resv_fences
> - Use dma_resv_usage_rw(false) (DMA_RESV_USAGE_WRITE)
> v3:
> - Rename add_fences and it's parameters
> - Remove signaled check
> - Remove waiting old_plane_state fences
> 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>
> Reviewed-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx>
> ---
> drivers/gpu/drm/i915/display/intel_atomic.c | 3 -
> .../gpu/drm/i915/display/intel_atomic_plane.c | 83 +++++++++++------
> --
> drivers/gpu/drm/i915/display/intel_display.c | 68 ++++-----------
> .../drm/i915/display/intel_display_types.h | 2 -
> 4 files changed, 61 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..3b9a66923422 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 +1015,41 @@ int intel_plane_check_src_coordinates(struct
> intel_plane_state *plane_state)
> return 0;
> }
>
> +static int add_dma_resv_fences(struct dma_resv *resv,
> + struct drm_plane_state
> *new_plane_state)
> +{
> + struct dma_fence *fence = dma_fence_get(new_plane_state-
> >fence);
> + struct dma_fence *new;
> + int ret;
> +
> + ret = dma_resv_get_singleton(resv, dma_resv_usage_rw(false),
> &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(new_plane_state->fence);
> + new_plane_state->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 +1073,7 @@ 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);
> @@ -1058,55 +1096,28 @@ intel_prepare_plane_fb(struct drm_plane
> *_plane,
> * 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);
> + ret = add_dma_resv_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->base,
> &new_plane_state->uapi);
> + 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_plane_
> state->hw.crtc,
> - fence);
> - }
> - dma_resv_iter_end(&cursor);
> - } else {
> intel_display_rps_boost_after_vblank(new_plane_state-
> >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 1caf46e3e569..6a37573c3d82 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 +7057,22 @@ 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;
> + int ret, i;
>
> - if (i915_sw_fence_done(&intel_state->commit_ready) ||
> - test_bit(I915_RESET_MODESET, &to_gt(dev_priv)-
> >reset.flags))
> - break;
> + for_each_new_plane_in_state(&intel_state->base, plane,
> 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;
>
> - schedule();
> + dma_fence_put(new_plane_state->fence);
> + new_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 +7364,6 @@ 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 +7386,6 @@ 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 +7418,6 @@ 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 +7433,6 @@ 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 +7446,6 @@ 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;
> };
>
