Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 745 insertions, 0 deletions

diff --git a/drivers/gpu/drm/nouveau/dispnv50/crc.c b/drivers/gpu/drm/nouveau/dispnv50/crc.c
new file mode 100644
index 000000000..b834e8a9a
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/dispnv50/crc.c
@@ -0,0 +1,745 @@
+// SPDX-License-Identifier: MIT
+#include <linux/string.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_vblank.h>
+#include <drm/drm_vblank_work.h>
+
+#include <nvif/class.h>
+#include <nvif/cl0002.h>
+#include <nvif/timer.h>
+
+#include <nvhw/class/cl907d.h>
+
+#include "nouveau_drv.h"
+#include "core.h"
+#include "head.h"
+#include "wndw.h"
+#include "handles.h"
+#include "crc.h"
+
+static const char * const nv50_crc_sources[] = {
+	[NV50_CRC_SOURCE_NONE] = "none",
+	[NV50_CRC_SOURCE_AUTO] = "auto",
+	[NV50_CRC_SOURCE_RG] = "rg",
+	[NV50_CRC_SOURCE_OUTP_ACTIVE] = "outp-active",
+	[NV50_CRC_SOURCE_OUTP_COMPLETE] = "outp-complete",
+	[NV50_CRC_SOURCE_OUTP_INACTIVE] = "outp-inactive",
+};
+
+static int nv50_crc_parse_source(const char *buf, enum nv50_crc_source *s)
+{
+	int i;
+
+	if (!buf) {
+		*s = NV50_CRC_SOURCE_NONE;
+		return 0;
+	}
+
+	i = match_string(nv50_crc_sources, ARRAY_SIZE(nv50_crc_sources), buf);
+	if (i < 0)
+		return i;
+
+	*s = i;
+	return 0;
+}
+
+int
+nv50_crc_verify_source(struct drm_crtc *crtc, const char *source_name,
+		       size_t *values_cnt)
+{
+	struct nouveau_drm *drm = nouveau_drm(crtc->dev);
+	enum nv50_crc_source source;
+
+	if (nv50_crc_parse_source(source_name, &source) < 0) {
+		NV_DEBUG(drm, "unknown source %s\n", source_name);
+		return -EINVAL;
+	}
+
+	*values_cnt = 1;
+	return 0;
+}
+
+const char *const *nv50_crc_get_sources(struct drm_crtc *crtc, size_t *count)
+{
+	*count = ARRAY_SIZE(nv50_crc_sources);
+	return nv50_crc_sources;
+}
+
+static void
+nv50_crc_program_ctx(struct nv50_head *head,
+		     struct nv50_crc_notifier_ctx *ctx)
+{
+	struct nv50_disp *disp = nv50_disp(head->base.base.dev);
+	struct nv50_core *core = disp->core;
+	u32 interlock[NV50_DISP_INTERLOCK__SIZE] = { 0 };
+
+	core->func->crc->set_ctx(head, ctx);
+	core->func->update(core, interlock, false);
+}
+
+static void nv50_crc_ctx_flip_work(struct kthread_work *base)
+{
+	struct drm_vblank_work *work = to_drm_vblank_work(base);
+	struct nv50_crc *crc = container_of(work, struct nv50_crc, flip_work);
+	struct nv50_head *head = container_of(crc, struct nv50_head, crc);
+	struct drm_crtc *crtc = &head->base.base;
+	struct drm_device *dev = crtc->dev;
+	struct nv50_disp *disp = nv50_disp(dev);
+	const uint64_t start_vbl = drm_crtc_vblank_count(crtc);
+	uint64_t end_vbl;
+	u8 new_idx = crc->ctx_idx ^ 1;
+
+	/*
+	 * We don't want to accidentally wait for longer then the vblank, so
+	 * try again for the next vblank if we don't grab the lock
+	 */
+	if (!mutex_trylock(&disp->mutex)) {
+		drm_dbg_kms(dev, "Lock contended, delaying CRC ctx flip for %s\n", crtc->name);
+		drm_vblank_work_schedule(work, start_vbl + 1, true);
+		return;
+	}
+
+	drm_dbg_kms(dev, "Flipping notifier ctx for %s (%d -> %d)\n",
+		    crtc->name, crc->ctx_idx, new_idx);
+
+	nv50_crc_program_ctx(head, NULL);
+	nv50_crc_program_ctx(head, &crc->ctx[new_idx]);
+	mutex_unlock(&disp->mutex);
+
+	end_vbl = drm_crtc_vblank_count(crtc);
+	if (unlikely(end_vbl != start_vbl))
+		NV_ERROR(nouveau_drm(dev),
+			 "Failed to flip CRC context on %s on time (%llu > %llu)\n",
+			 crtc->name, end_vbl, start_vbl);
+
+	spin_lock_irq(&crc->lock);
+	crc->ctx_changed = true;
+	spin_unlock_irq(&crc->lock);
+}
+
+static inline void nv50_crc_reset_ctx(struct nv50_crc_notifier_ctx *ctx)
+{
+	memset_io(ctx->mem.object.map.ptr, 0, ctx->mem.object.map.size);
+}
+
+static void
+nv50_crc_get_entries(struct nv50_head *head,
+		     const struct nv50_crc_func *func,
+		     enum nv50_crc_source source)
+{
+	struct drm_crtc *crtc = &head->base.base;
+	struct nv50_crc *crc = &head->crc;
+	u32 output_crc;
+
+	while (crc->entry_idx < func->num_entries) {
+		/*
+		 * While Nvidia's documentation says CRCs are written on each
+		 * subsequent vblank after being enabled, in practice they
+		 * aren't written immediately.
+		 */
+		output_crc = func->get_entry(head, &crc->ctx[crc->ctx_idx],
+					     source, crc->entry_idx);
+		if (!output_crc)
+			return;
+
+		drm_crtc_add_crc_entry(crtc, true, crc->frame, &output_crc);
+		crc->frame++;
+		crc->entry_idx++;
+	}
+}
+
+void nv50_crc_handle_vblank(struct nv50_head *head)
+{
+	struct drm_crtc *crtc = &head->base.base;
+	struct nv50_crc *crc = &head->crc;
+	const struct nv50_crc_func *func =
+		nv50_disp(head->base.base.dev)->core->func->crc;
+	struct nv50_crc_notifier_ctx *ctx;
+	bool need_reschedule = false;
+
+	if (!func)
+		return;
+
+	/*
+	 * We don't lose events if we aren't able to report CRCs until the
+	 * next vblank, so only report CRCs if the locks we need aren't
+	 * contended to prevent missing an actual vblank event
+	 */
+	if (!spin_trylock(&crc->lock))
+		return;
+
+	if (!crc->src)
+		goto out;
+
+	ctx = &crc->ctx[crc->ctx_idx];
+	if (crc->ctx_changed && func->ctx_finished(head, ctx)) {
+		nv50_crc_get_entries(head, func, crc->src);
+
+		crc->ctx_idx ^= 1;
+		crc->entry_idx = 0;
+		crc->ctx_changed = false;
+
+		/*
+		 * Unfortunately when notifier contexts are changed during CRC
+		 * capture, we will inevitably lose the CRC entry for the
+		 * frame where the hardware actually latched onto the first
+		 * UPDATE. According to Nvidia's hardware engineers, there's
+		 * no workaround for this.
+		 *
+		 * Now, we could try to be smart here and calculate the number
+		 * of missed CRCs based on audit timestamps, but those were
+		 * removed starting with volta. Since we always flush our
+		 * updates back-to-back without waiting, we'll just be
+		 * optimistic and assume we always miss exactly one frame.
+		 */
+		drm_dbg_kms(head->base.base.dev,
+			    "Notifier ctx flip for head-%d finished, lost CRC for frame %llu\n",
+			    head->base.index, crc->frame);
+		crc->frame++;
+
+		nv50_crc_reset_ctx(ctx);
+		need_reschedule = true;
+	}
+
+	nv50_crc_get_entries(head, func, crc->src);
+
+	if (need_reschedule)
+		drm_vblank_work_schedule(&crc->flip_work,
+					 drm_crtc_vblank_count(crtc)
+					 + crc->flip_threshold
+					 - crc->entry_idx,
+					 true);
+
+out:
+	spin_unlock(&crc->lock);
+}
+
+static void nv50_crc_wait_ctx_finished(struct nv50_head *head,
+				       const struct nv50_crc_func *func,
+				       struct nv50_crc_notifier_ctx *ctx)
+{
+	struct drm_device *dev = head->base.base.dev;
+	struct nouveau_drm *drm = nouveau_drm(dev);
+	s64 ret;
+
+	ret = nvif_msec(&drm->client.device, 50,
+			if (func->ctx_finished(head, ctx)) break;);
+	if (ret == -ETIMEDOUT)
+		NV_ERROR(drm,
+			 "CRC notifier ctx for head %d not finished after 50ms\n",
+			 head->base.index);
+	else if (ret)
+		NV_ATOMIC(drm,
+			  "CRC notifier ctx for head-%d finished after %lldns\n",
+			  head->base.index, ret);
+}
+
+void nv50_crc_atomic_stop_reporting(struct drm_atomic_state *state)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_crtc *crtc;
+	int i;
+
+	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
+		struct nv50_head *head = nv50_head(crtc);
+		struct nv50_head_atom *asyh = nv50_head_atom(crtc_state);
+		struct nv50_crc *crc = &head->crc;
+
+		if (!asyh->clr.crc)
+			continue;
+
+		spin_lock_irq(&crc->lock);
+		crc->src = NV50_CRC_SOURCE_NONE;
+		spin_unlock_irq(&crc->lock);
+
+		drm_crtc_vblank_put(crtc);
+		drm_vblank_work_cancel_sync(&crc->flip_work);
+
+		NV_ATOMIC(nouveau_drm(crtc->dev),
+			  "CRC reporting on vblank for head-%d disabled\n",
+			  head->base.index);
+
+		/* CRC generation is still enabled in hw, we'll just report
+		 * any remaining CRC entries ourselves after it gets disabled
+		 * in hardware
+		 */
+	}
+}
+
+void nv50_crc_atomic_init_notifier_contexts(struct drm_atomic_state *state)
+{
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_crtc *crtc;
+	int i;
+
+	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
+		struct nv50_head *head = nv50_head(crtc);
+		struct nv50_head_atom *asyh = nv50_head_atom(new_crtc_state);
+		struct nv50_crc *crc = &head->crc;
+		int i;
+
+		if (!asyh->set.crc)
+			continue;
+
+		crc->entry_idx = 0;
+		crc->ctx_changed = false;
+		for (i = 0; i < ARRAY_SIZE(crc->ctx); i++)
+			nv50_crc_reset_ctx(&crc->ctx[i]);
+	}
+}
+
+void nv50_crc_atomic_release_notifier_contexts(struct drm_atomic_state *state)
+{
+	const struct nv50_crc_func *func =
+		nv50_disp(state->dev)->core->func->crc;
+	struct drm_crtc_state *new_crtc_state;
+	struct drm_crtc *crtc;
+	int i;
+
+	for_each_new_crtc_in_state(state, crtc, new_crtc_state, i) {
+		struct nv50_head *head = nv50_head(crtc);
+		struct nv50_head_atom *asyh = nv50_head_atom(new_crtc_state);
+		struct nv50_crc *crc = &head->crc;
+		struct nv50_crc_notifier_ctx *ctx = &crc->ctx[crc->ctx_idx];
+
+		if (!asyh->clr.crc)
+			continue;
+
+		if (crc->ctx_changed) {
+			nv50_crc_wait_ctx_finished(head, func, ctx);
+			ctx = &crc->ctx[crc->ctx_idx ^ 1];
+		}
+		nv50_crc_wait_ctx_finished(head, func, ctx);
+	}
+}
+
+void nv50_crc_atomic_start_reporting(struct drm_atomic_state *state)
+{
+	struct drm_crtc_state *crtc_state;
+	struct drm_crtc *crtc;
+	int i;
+
+	for_each_new_crtc_in_state(state, crtc, crtc_state, i) {
+		struct nv50_head *head = nv50_head(crtc);
+		struct nv50_head_atom *asyh = nv50_head_atom(crtc_state);
+		struct nv50_crc *crc = &head->crc;
+		u64 vbl_count;
+
+		if (!asyh->set.crc)
+			continue;
+
+		drm_crtc_vblank_get(crtc);
+
+		spin_lock_irq(&crc->lock);
+		vbl_count = drm_crtc_vblank_count(crtc);
+		crc->frame = vbl_count;
+		crc->src = asyh->crc.src;
+		drm_vblank_work_schedule(&crc->flip_work,
+					 vbl_count + crc->flip_threshold,
+					 true);
+		spin_unlock_irq(&crc->lock);
+
+		NV_ATOMIC(nouveau_drm(crtc->dev),
+			  "CRC reporting on vblank for head-%d enabled\n",
+			  head->base.index);
+	}
+}
+
+int nv50_crc_atomic_check_head(struct nv50_head *head,
+			       struct nv50_head_atom *asyh,
+			       struct nv50_head_atom *armh)
+{
+	struct nv50_atom *atom = nv50_atom(asyh->state.state);
+	bool changed = armh->crc.src != asyh->crc.src;
+
+	if (!armh->crc.src && !asyh->crc.src) {
+		asyh->set.crc = false;
+		asyh->clr.crc = false;
+		return 0;
+	}
+
+	if (drm_atomic_crtc_needs_modeset(&asyh->state) || changed) {
+		asyh->clr.crc = armh->crc.src && armh->state.active;
+		asyh->set.crc = asyh->crc.src && asyh->state.active;
+		if (changed)
+			asyh->set.or |= armh->or.crc_raster !=
+					asyh->or.crc_raster;
+
+		if (asyh->clr.crc && asyh->set.crc)
+			atom->flush_disable = true;
+	} else {
+		asyh->set.crc = false;
+		asyh->clr.crc = false;
+	}
+
+	return 0;
+}
+
+void nv50_crc_atomic_check_outp(struct nv50_atom *atom)
+{
+	struct drm_crtc *crtc;
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	int i;
+
+	if (atom->flush_disable)
+		return;
+
+	for_each_oldnew_crtc_in_state(&atom->state, crtc, old_crtc_state,
+				      new_crtc_state, i) {
+		struct nv50_head_atom *armh = nv50_head_atom(old_crtc_state);
+		struct nv50_head_atom *asyh = nv50_head_atom(new_crtc_state);
+		struct nv50_outp_atom *outp_atom;
+		struct nouveau_encoder *outp;
+		struct drm_encoder *encoder, *enc;
+
+		enc = nv50_head_atom_get_encoder(armh);
+		if (!enc)
+			continue;
+
+		outp = nv50_real_outp(enc);
+		if (!outp)
+			continue;
+
+		encoder = &outp->base.base;
+
+		if (!asyh->clr.crc)
+			continue;
+
+		/*
+		 * Re-programming ORs can't be done in the same flush as
+		 * disabling CRCs
+		 */
+		list_for_each_entry(outp_atom, &atom->outp, head) {
+			if (outp_atom->encoder == encoder) {
+				if (outp_atom->set.mask) {
+					atom->flush_disable = true;
+					return;
+				} else {
+					break;
+				}
+			}
+		}
+	}
+}
+
+static enum nv50_crc_source_type
+nv50_crc_source_type(struct nouveau_encoder *outp,
+		     enum nv50_crc_source source)
+{
+	struct dcb_output *dcbe = outp->dcb;
+
+	switch (source) {
+	case NV50_CRC_SOURCE_NONE: return NV50_CRC_SOURCE_TYPE_NONE;
+	case NV50_CRC_SOURCE_RG:   return NV50_CRC_SOURCE_TYPE_RG;
+	default:		   break;
+	}
+
+	if (dcbe->location != DCB_LOC_ON_CHIP)
+		return NV50_CRC_SOURCE_TYPE_PIOR;
+
+	switch (dcbe->type) {
+	case DCB_OUTPUT_DP:	return NV50_CRC_SOURCE_TYPE_SF;
+	case DCB_OUTPUT_ANALOG:	return NV50_CRC_SOURCE_TYPE_DAC;
+	default:		return NV50_CRC_SOURCE_TYPE_SOR;
+	}
+}
+
+void nv50_crc_atomic_set(struct nv50_head *head,
+			 struct nv50_head_atom *asyh)
+{
+	struct drm_crtc *crtc = &head->base.base;
+	struct drm_device *dev = crtc->dev;
+	struct nv50_crc *crc = &head->crc;
+	const struct nv50_crc_func *func = nv50_disp(dev)->core->func->crc;
+	struct nouveau_encoder *outp;
+	struct drm_encoder *encoder;
+
+	encoder = nv50_head_atom_get_encoder(asyh);
+	if (!encoder)
+		return;
+
+	outp = nv50_real_outp(encoder);
+	if (!outp)
+		return;
+
+	func->set_src(head, outp->or, nv50_crc_source_type(outp, asyh->crc.src),
+		      &crc->ctx[crc->ctx_idx]);
+}
+
+void nv50_crc_atomic_clr(struct nv50_head *head)
+{
+	const struct nv50_crc_func *func =
+		nv50_disp(head->base.base.dev)->core->func->crc;
+
+	func->set_src(head, 0, NV50_CRC_SOURCE_TYPE_NONE, NULL);
+}
+
+static inline int
+nv50_crc_raster_type(enum nv50_crc_source source)
+{
+	switch (source) {
+	case NV50_CRC_SOURCE_NONE:
+	case NV50_CRC_SOURCE_AUTO:
+	case NV50_CRC_SOURCE_RG:
+	case NV50_CRC_SOURCE_OUTP_ACTIVE:
+		return NV907D_HEAD_SET_CONTROL_OUTPUT_RESOURCE_CRC_MODE_ACTIVE_RASTER;
+	case NV50_CRC_SOURCE_OUTP_COMPLETE:
+		return NV907D_HEAD_SET_CONTROL_OUTPUT_RESOURCE_CRC_MODE_COMPLETE_RASTER;
+	case NV50_CRC_SOURCE_OUTP_INACTIVE:
+		return NV907D_HEAD_SET_CONTROL_OUTPUT_RESOURCE_CRC_MODE_NON_ACTIVE_RASTER;
+	}
+
+	return 0;
+}
+
+/* We handle mapping the memory for CRC notifiers ourselves, since each
+ * notifier needs it's own handle
+ */
+static inline int
+nv50_crc_ctx_init(struct nv50_head *head, struct nvif_mmu *mmu,
+		  struct nv50_crc_notifier_ctx *ctx, size_t len, int idx)
+{
+	struct nv50_core *core = nv50_disp(head->base.base.dev)->core;
+	int ret;
+
+	ret = nvif_mem_ctor_map(mmu, "kmsCrcNtfy", NVIF_MEM_VRAM, len, &ctx->mem);
+	if (ret)
+		return ret;
+
+	ret = nvif_object_ctor(&core->chan.base.user, "kmsCrcNtfyCtxDma",
+			       NV50_DISP_HANDLE_CRC_CTX(head, idx),
+			       NV_DMA_IN_MEMORY,
+			       &(struct nv_dma_v0) {
+					.target = NV_DMA_V0_TARGET_VRAM,
+					.access = NV_DMA_V0_ACCESS_RDWR,
+					.start = ctx->mem.addr,
+					.limit =  ctx->mem.addr
+						+ ctx->mem.size - 1,
+			       }, sizeof(struct nv_dma_v0),
+			       &ctx->ntfy);
+	if (ret)
+		goto fail_fini;
+
+	return 0;
+
+fail_fini:
+	nvif_mem_dtor(&ctx->mem);
+	return ret;
+}
+
+static inline void
+nv50_crc_ctx_fini(struct nv50_crc_notifier_ctx *ctx)
+{
+	nvif_object_dtor(&ctx->ntfy);
+	nvif_mem_dtor(&ctx->mem);
+}
+
+int nv50_crc_set_source(struct drm_crtc *crtc, const char *source_str)
+{
+	struct drm_device *dev = crtc->dev;
+	struct drm_atomic_state *state;
+	struct drm_modeset_acquire_ctx ctx;
+	struct nv50_head *head = nv50_head(crtc);
+	struct nv50_crc *crc = &head->crc;
+	const struct nv50_crc_func *func = nv50_disp(dev)->core->func->crc;
+	struct nvif_mmu *mmu = &nouveau_drm(dev)->client.mmu;
+	struct nv50_head_atom *asyh;
+	struct drm_crtc_state *crtc_state;
+	enum nv50_crc_source source;
+	int ret = 0, ctx_flags = 0, i;
+
+	ret = nv50_crc_parse_source(source_str, &source);
+	if (ret)
+		return ret;
+
+	/*
+	 * Since we don't want the user to accidentally interrupt us as we're
+	 * disabling CRCs
+	 */
+	if (source)
+		ctx_flags |= DRM_MODESET_ACQUIRE_INTERRUPTIBLE;
+	drm_modeset_acquire_init(&ctx, ctx_flags);
+
+	state = drm_atomic_state_alloc(dev);
+	if (!state) {
+		ret = -ENOMEM;
+		goto out_acquire_fini;
+	}
+	state->acquire_ctx = &ctx;
+
+	if (source) {
+		for (i = 0; i < ARRAY_SIZE(head->crc.ctx); i++) {
+			ret = nv50_crc_ctx_init(head, mmu, &crc->ctx[i],
+						func->notifier_len, i);
+			if (ret)
+				goto out_ctx_fini;
+		}
+	}
+
+retry:
+	crtc_state = drm_atomic_get_crtc_state(state, &head->base.base);
+	if (IS_ERR(crtc_state)) {
+		ret = PTR_ERR(crtc_state);
+		if (ret == -EDEADLK)
+			goto deadlock;
+		else if (ret)
+			goto out_drop_locks;
+	}
+	asyh = nv50_head_atom(crtc_state);
+	asyh->crc.src = source;
+	asyh->or.crc_raster = nv50_crc_raster_type(source);
+
+	ret = drm_atomic_commit(state);
+	if (ret == -EDEADLK)
+		goto deadlock;
+	else if (ret)
+		goto out_drop_locks;
+
+	if (!source) {
+		/*
+		 * If the user specified a custom flip threshold through
+		 * debugfs, reset it
+		 */
+		crc->flip_threshold = func->flip_threshold;
+	}
+
+out_drop_locks:
+	drm_modeset_drop_locks(&ctx);
+out_ctx_fini:
+	if (!source || ret) {
+		for (i = 0; i < ARRAY_SIZE(crc->ctx); i++)
+			nv50_crc_ctx_fini(&crc->ctx[i]);
+	}
+	drm_atomic_state_put(state);
+out_acquire_fini:
+	drm_modeset_acquire_fini(&ctx);
+	return ret;
+
+deadlock:
+	drm_atomic_state_clear(state);
+	drm_modeset_backoff(&ctx);
+	goto retry;
+}
+
+static int
+nv50_crc_debugfs_flip_threshold_get(struct seq_file *m, void *data)
+{
+	struct nv50_head *head = m->private;
+	struct drm_crtc *crtc = &head->base.base;
+	struct nv50_crc *crc = &head->crc;
+	int ret;
+
+	ret = drm_modeset_lock_single_interruptible(&crtc->mutex);
+	if (ret)
+		return ret;
+
+	seq_printf(m, "%d\n", crc->flip_threshold);
+
+	drm_modeset_unlock(&crtc->mutex);
+	return ret;
+}
+
+static int
+nv50_crc_debugfs_flip_threshold_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, nv50_crc_debugfs_flip_threshold_get,
+			   inode->i_private);
+}
+
+static ssize_t
+nv50_crc_debugfs_flip_threshold_set(struct file *file,
+				    const char __user *ubuf, size_t len,
+				    loff_t *offp)
+{
+	struct seq_file *m = file->private_data;
+	struct nv50_head *head = m->private;
+	struct nv50_head_atom *armh;
+	struct drm_crtc *crtc = &head->base.base;
+	struct nouveau_drm *drm = nouveau_drm(crtc->dev);
+	struct nv50_crc *crc = &head->crc;
+	const struct nv50_crc_func *func =
+		nv50_disp(crtc->dev)->core->func->crc;
+	int value, ret;
+
+	ret = kstrtoint_from_user(ubuf, len, 10, &value);
+	if (ret)
+		return ret;
+
+	if (value > func->flip_threshold)
+		return -EINVAL;
+	else if (value == -1)
+		value = func->flip_threshold;
+	else if (value < -1)
+		return -EINVAL;
+
+	ret = drm_modeset_lock_single_interruptible(&crtc->mutex);
+	if (ret)
+		return ret;
+
+	armh = nv50_head_atom(crtc->state);
+	if (armh->crc.src) {
+		ret = -EBUSY;
+		goto out;
+	}
+
+	NV_DEBUG(drm,
+		 "Changing CRC flip threshold for next capture on head-%d to %d\n",
+		 head->base.index, value);
+	crc->flip_threshold = value;
+	ret = len;
+
+out:
+	drm_modeset_unlock(&crtc->mutex);
+	return ret;
+}
+
+static const struct file_operations nv50_crc_flip_threshold_fops = {
+	.owner = THIS_MODULE,
+	.open = nv50_crc_debugfs_flip_threshold_open,
+	.read = seq_read,
+	.write = nv50_crc_debugfs_flip_threshold_set,
+	.release = single_release,
+};
+
+int nv50_head_crc_late_register(struct nv50_head *head)
+{
+	struct drm_crtc *crtc = &head->base.base;
+	const struct nv50_crc_func *func =
+		nv50_disp(crtc->dev)->core->func->crc;
+	struct dentry *root;
+
+	if (!func || !crtc->debugfs_entry)
+		return 0;
+
+	root = debugfs_create_dir("nv_crc", crtc->debugfs_entry);
+	debugfs_create_file("flip_threshold", 0644, root, head,
+			    &nv50_crc_flip_threshold_fops);
+
+	return 0;
+}
+
+static inline void
+nv50_crc_init_head(struct nv50_disp *disp, const struct nv50_crc_func *func,
+		   struct nv50_head *head)
+{
+	struct nv50_crc *crc = &head->crc;
+
+	crc->flip_threshold = func->flip_threshold;
+	spin_lock_init(&crc->lock);
+	drm_vblank_work_init(&crc->flip_work, &head->base.base,
+			     nv50_crc_ctx_flip_work);
+}
+
+void nv50_crc_init(struct drm_device *dev)
+{
+	struct nv50_disp *disp = nv50_disp(dev);
+	struct drm_crtc *crtc;
+	const struct nv50_crc_func *func = disp->core->func->crc;
+
+	if (!func)
+		return;
+
+	drm_for_each_crtc(crtc, dev)
+		nv50_crc_init_head(disp, func, nv50_head(crtc));
+}