On Wed, Feb 12, 2020 at 08:15:22PM +0530, Animesh Manna wrote:
> Pre-allocate command buffer in atomic_commit using intel_dsb_prepare
> function which also includes pinning and map in cpu domain.
>
> No change is dsb write/commit functions.
>
> Now dsb get/put function is refactored and currently used only for
> reference counting. Below dsb api added to do respective job
> mentioned below.
>
> intel_dsb_prepare - Allocate, pin and map the buffer.
> intel_dsb_cleanup - Unpin and release the gem object.
>
> RFC: Initial patch for design review.
> v2: included _init() part in _prepare(). [Daniel, Ville]
> v3: dsb_cleanup called after cleanup_planes. [Daniel]
>
> Cc: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Cc: Jani Nikula <jani.nikula at intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Signed-off-by: Animesh Manna <animesh.manna at intel.com>
I think this should fit a lot better wrt the dma_resv locking rework
that's ongoing.
Acked-by: Daniel Vetter <daniel.vetter at ffwll.ch>
Cheers, Daniel
> ---
> drivers/gpu/drm/i915/display/intel_display.c | 36 ++++-
> drivers/gpu/drm/i915/display/intel_dsb.c | 132 ++++++++++++-------
> drivers/gpu/drm/i915/display/intel_dsb.h | 2 +
> 3 files changed, 116 insertions(+), 54 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c b/drivers/gpu/drm/i915/display/intel_display.c
> index 61ba1f2256a0..ae90687e3a6b 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -15076,6 +15076,19 @@ static int intel_atomic_check(struct drm_device *dev,
>
> static int intel_atomic_prepare_commit(struct intel_atomic_state *state)
> {
> + struct intel_crtc_state *crtc_state;
> + struct intel_crtc *crtc;
> + int i;
> +
> + for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i) {
> + bool mode_changed = needs_modeset(crtc_state);
> +
> + if (mode_changed || crtc_state->update_pipe ||
> + crtc_state->uapi.color_mgmt_changed) {
> + intel_dsb_prepare(crtc);
> + }
> + }
> +
> return drm_atomic_helper_prepare_planes(state->base.dev,
> &state->base);
> }
> @@ -15643,15 +15656,26 @@ static void intel_atomic_commit_fence_wait(struct intel_atomic_state *intel_stat
> &wait_reset);
> }
>
> +static void intel_cleanup_dsbs(struct intel_atomic_state *state)
> +{
> + struct intel_crtc_state *crtc_state;
> + struct intel_crtc *crtc;
> + int i;
> +
> + for_each_new_intel_crtc_in_state(state, crtc, crtc_state, i)
> + intel_dsb_cleanup(crtc);
> +}
> +
> static void intel_atomic_cleanup_work(struct work_struct *work)
> {
> - struct drm_atomic_state *state =
> - container_of(work, struct drm_atomic_state, commit_work);
> - struct drm_i915_private *i915 = to_i915(state->dev);
> + struct intel_atomic_state *state =
> + container_of(work, struct intel_atomic_state, base.commit_work);
> + struct drm_i915_private *i915 = to_i915(state->base.dev);
>
> - drm_atomic_helper_cleanup_planes(&i915->drm, state);
> - drm_atomic_helper_commit_cleanup_done(state);
> - drm_atomic_state_put(state);
> + drm_atomic_helper_cleanup_planes(&i915->drm, &state->base);
> + intel_cleanup_dsbs(state);
> + drm_atomic_helper_commit_cleanup_done(&state->base);
> + drm_atomic_state_put(&state->base);
>
> intel_atomic_helper_free_state(i915);
> }
> diff --git a/drivers/gpu/drm/i915/display/intel_dsb.c b/drivers/gpu/drm/i915/display/intel_dsb.c
> index 76ae01277fd6..c31132c41e0f 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsb.c
> +++ b/drivers/gpu/drm/i915/display/intel_dsb.c
> @@ -34,6 +34,86 @@
> #define DSB_BYTE_EN_SHIFT 20
> #define DSB_REG_VALUE_MASK 0xfffff
>
> +/**
> + * intel_dsb_prepare() - Allocate, pin and map the DSB command buffer.
> + * @crtc: intel_crtc structure to get pipe info.
> + *
> + * This function prepare the command buffer which is used to store dsb
> + * instructions with data.
> + */
> +
> +void intel_dsb_prepare(struct intel_crtc *crtc)
> +{
> + struct drm_device *dev = crtc->base.dev;
> + struct drm_i915_private *i915 = to_i915(dev);
> + struct intel_dsb *dsb = &crtc->dsb;
> + struct drm_i915_gem_object *obj;
> + struct i915_vma *vma;
> + u32 *buf;
> + intel_wakeref_t wakeref;
> +
> + if (!HAS_DSB(i915) || dsb->cmd_buf)
> + return;
> +
> + wakeref = intel_runtime_pm_get(&i915->runtime_pm);
> +
> + obj = i915_gem_object_create_internal(i915, DSB_BUF_SIZE);
> + if (IS_ERR(obj)) {
> + DRM_ERROR("Gem object creation failed\n");
> + goto out;
> + }
> +
> + vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
> + if (IS_ERR(vma)) {
> + DRM_ERROR("Vma creation failed\n");
> + i915_gem_object_put(obj);
> + goto out;
> + }
> +
> + buf = i915_gem_object_pin_map(vma->obj, I915_MAP_WC);
> + if (IS_ERR(buf)) {
> + DRM_ERROR("Command buffer creation failed\n");
> + goto out;
> + }
> +
> + dsb->id = DSB1;
> + dsb->vma = vma;
> + dsb->cmd_buf = buf;
> +
> +out:
> + /*
> + * On error dsb->cmd_buf will continue to be NULL, making the writes
> + * pass-through. Leave the dangling ref to be removed later by the
> + * corresponding intel_dsb_put(): the important error message will
> + * already be logged above.
> + */
> +
> + intel_runtime_pm_put(&i915->runtime_pm, wakeref);
> +}
> +
> +/**
> + * intel_dsb_cleanup() - To cleanup DSB context.
> + * @dsb: intel_dsb structure.
> + *
> + * This function cleanup the DSB context by unpinning and releasing
> + * the VMA object associated with it.
> + */
> +
> +void intel_dsb_cleanup(struct intel_crtc *crtc)
> +{
> + struct drm_i915_private *i915 = to_i915(crtc->base.dev);
> + struct intel_dsb *dsb = &crtc->dsb;
> +
> + if (!HAS_DSB(i915))
> + return;
> +
> + if (dsb->vma) {
> + i915_vma_unpin_and_release(&dsb->vma, I915_VMA_RELEASE_MAP);
> + dsb->vma = NULL;
> + dsb->cmd_buf = NULL;
> + }
> +}
> +
> static inline bool is_dsb_busy(struct intel_dsb *dsb)
> {
> struct intel_crtc *crtc = container_of(dsb, typeof(*crtc), dsb);
> @@ -84,14 +164,13 @@ static inline bool intel_dsb_disable_engine(struct intel_dsb *dsb)
> }
>
> /**
> - * intel_dsb_get() - Allocate DSB context and return a DSB instance.
> + * intel_dsb_get() - Return a DSB instance and increase reference count.
> * @crtc: intel_crtc structure to get pipe info.
> *
> * This function provides handle of a DSB instance, for the further DSB
> * operations.
> *
> * Returns: address of Intel_dsb instance requested for.
> - * Failure: Returns the same DSB instance, but without a command buffer.
> */
>
> struct intel_dsb *
> @@ -100,52 +179,11 @@ intel_dsb_get(struct intel_crtc *crtc)
> struct drm_device *dev = crtc->base.dev;
> struct drm_i915_private *i915 = to_i915(dev);
> struct intel_dsb *dsb = &crtc->dsb;
> - struct drm_i915_gem_object *obj;
> - struct i915_vma *vma;
> - u32 *buf;
> - intel_wakeref_t wakeref;
>
> if (!HAS_DSB(i915))
> return dsb;
>
> - if (dsb->refcount++ != 0)
> - return dsb;
> -
> - wakeref = intel_runtime_pm_get(&i915->runtime_pm);
> -
> - obj = i915_gem_object_create_internal(i915, DSB_BUF_SIZE);
> - if (IS_ERR(obj)) {
> - DRM_ERROR("Gem object creation failed\n");
> - goto out;
> - }
> -
> - vma = i915_gem_object_ggtt_pin(obj, NULL, 0, 0, 0);
> - if (IS_ERR(vma)) {
> - DRM_ERROR("Vma creation failed\n");
> - i915_gem_object_put(obj);
> - goto out;
> - }
> -
> - buf = i915_gem_object_pin_map(vma->obj, I915_MAP_WC);
> - if (IS_ERR(buf)) {
> - DRM_ERROR("Command buffer creation failed\n");
> - goto out;
> - }
> -
> - dsb->id = DSB1;
> - dsb->vma = vma;
> - dsb->cmd_buf = buf;
> -
> -out:
> - /*
> - * On error dsb->cmd_buf will continue to be NULL, making the writes
> - * pass-through. Leave the dangling ref to be removed later by the
> - * corresponding intel_dsb_put(): the important error message will
> - * already be logged above.
> - */
> -
> - intel_runtime_pm_put(&i915->runtime_pm, wakeref);
> -
> + dsb->refcount++;
> return dsb;
> }
>
> @@ -153,8 +191,8 @@ intel_dsb_get(struct intel_crtc *crtc)
> * intel_dsb_put() - To destroy DSB context.
> * @dsb: intel_dsb structure.
> *
> - * This function destroys the DSB context allocated by a dsb_get(), by
> - * unpinning and releasing the VMA object associated with it.
> + * This function decrease the reference count and reset the command
> + * buffer position.
> */
>
> void intel_dsb_put(struct intel_dsb *dsb)
> @@ -169,8 +207,6 @@ void intel_dsb_put(struct intel_dsb *dsb)
> return;
>
> if (--dsb->refcount == 0) {
> - i915_vma_unpin_and_release(&dsb->vma, I915_VMA_RELEASE_MAP);
> - dsb->cmd_buf = NULL;
> dsb->free_pos = 0;
> dsb->ins_start_offset = 0;
> }
> diff --git a/drivers/gpu/drm/i915/display/intel_dsb.h b/drivers/gpu/drm/i915/display/intel_dsb.h
> index 395ef9ce558e..1dcce198899a 100644
> --- a/drivers/gpu/drm/i915/display/intel_dsb.h
> +++ b/drivers/gpu/drm/i915/display/intel_dsb.h
> @@ -41,6 +41,8 @@ struct intel_dsb {
> u32 ins_start_offset;
> };
>
> +void intel_dsb_prepare(struct intel_crtc *crtc);
> +void intel_dsb_cleanup(struct intel_crtc *crtc);
> struct intel_dsb *
> intel_dsb_get(struct intel_crtc *crtc);
> void intel_dsb_put(struct intel_dsb *dsb);
> --
> 2.24.0
>
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch