1 files changed, 181 insertions, 63 deletions

diff --git a/drivers/gpu/drm/vc4/vc4_kms.c b/drivers/gpu/drm/vc4/vc4_kms.c
index 2b951cae04ad..ba310c0ab5f6 100644
--- a/drivers/gpu/drm/vc4/vc4_kms.c
+++ b/drivers/gpu/drm/vc4/vc4_kms.c
@@ -24,6 +24,8 @@
 #include "vc4_drv.h"
 #include "vc4_regs.h"
 
+#define HVS_NUM_CHANNELS 3
+
 struct vc4_ctm_state {
 	struct drm_private_state base;
 	struct drm_color_ctm *ctm;
@@ -35,6 +37,17 @@ static struct vc4_ctm_state *to_vc4_ctm_state(struct drm_private_state *priv)
 	return container_of(priv, struct vc4_ctm_state, base);
 }
 
+struct vc4_hvs_state {
+	struct drm_private_state base;
+	unsigned int unassigned_channels;
+};
+
+static struct vc4_hvs_state *
+to_vc4_hvs_state(struct drm_private_state *priv)
+{
+	return container_of(priv, struct vc4_hvs_state, base);
+}
+
 struct vc4_load_tracker_state {
 	struct drm_private_state base;
 	u64 hvs_load;
@@ -113,7 +126,7 @@ static int vc4_ctm_obj_init(struct vc4_dev *vc4)
 	drm_atomic_private_obj_init(&vc4->base, &vc4->ctm_manager, &ctm_state->base,
 				    &vc4_ctm_state_funcs);
 
-	return drmm_add_action(&vc4->base, vc4_ctm_obj_fini, NULL);
+	return drmm_add_action_or_reset(&vc4->base, vc4_ctm_obj_fini, NULL);
 }
 
 /* Converts a DRM S31.32 value to the HW S0.9 format. */
@@ -169,6 +182,19 @@ vc4_ctm_commit(struct vc4_dev *vc4, struct drm_atomic_state *state)
 		  VC4_SET_FIELD(ctm_state->fifo, SCALER_OLEDOFFS_DISPFIFO));
 }
 
+static struct vc4_hvs_state *
+vc4_hvs_get_global_state(struct drm_atomic_state *state)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(state->dev);
+	struct drm_private_state *priv_state;
+
+	priv_state = drm_atomic_get_private_obj_state(state, &vc4->hvs_channels);
+	if (IS_ERR(priv_state))
+		return ERR_CAST(priv_state);
+
+	return to_vc4_hvs_state(priv_state);
+}
+
 static void vc4_hvs_pv_muxing_commit(struct vc4_dev *vc4,
 				     struct drm_atomic_state *state)
 {
@@ -213,10 +239,7 @@ static void vc5_hvs_pv_muxing_commit(struct vc4_dev *vc4,
 {
 	struct drm_crtc_state *crtc_state;
 	struct drm_crtc *crtc;
-	unsigned char dsp2_mux = 0;
-	unsigned char dsp3_mux = 3;
-	unsigned char dsp4_mux = 3;
-	unsigned char dsp5_mux = 3;
+	unsigned char mux;
 	unsigned int i;
 	u32 reg;
 
@@ -224,50 +247,59 @@ static void vc5_hvs_pv_muxing_commit(struct vc4_dev *vc4,
 		struct vc4_crtc_state *vc4_state = to_vc4_crtc_state(crtc_state);
 		struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
 
-		if (!crtc_state->active)
+		if (!vc4_state->update_muxing)
 			continue;
 
 		switch (vc4_crtc->data->hvs_output) {
 		case 2:
-			dsp2_mux = (vc4_state->assigned_channel == 2) ? 0 : 1;
+			mux = (vc4_state->assigned_channel == 2) ? 0 : 1;
+			reg = HVS_READ(SCALER_DISPECTRL);
+			HVS_WRITE(SCALER_DISPECTRL,
+				  (reg & ~SCALER_DISPECTRL_DSP2_MUX_MASK) |
+				  VC4_SET_FIELD(mux, SCALER_DISPECTRL_DSP2_MUX));
 			break;
 
 		case 3:
-			dsp3_mux = vc4_state->assigned_channel;
+			if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED)
+				mux = 3;
+			else
+				mux = vc4_state->assigned_channel;
+
+			reg = HVS_READ(SCALER_DISPCTRL);
+			HVS_WRITE(SCALER_DISPCTRL,
+				  (reg & ~SCALER_DISPCTRL_DSP3_MUX_MASK) |
+				  VC4_SET_FIELD(mux, SCALER_DISPCTRL_DSP3_MUX));
 			break;
 
 		case 4:
-			dsp4_mux = vc4_state->assigned_channel;
+			if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED)
+				mux = 3;
+			else
+				mux = vc4_state->assigned_channel;
+
+			reg = HVS_READ(SCALER_DISPEOLN);
+			HVS_WRITE(SCALER_DISPEOLN,
+				  (reg & ~SCALER_DISPEOLN_DSP4_MUX_MASK) |
+				  VC4_SET_FIELD(mux, SCALER_DISPEOLN_DSP4_MUX));
+
 			break;
 
 		case 5:
-			dsp5_mux = vc4_state->assigned_channel;
+			if (vc4_state->assigned_channel == VC4_HVS_CHANNEL_DISABLED)
+				mux = 3;
+			else
+				mux = vc4_state->assigned_channel;
+
+			reg = HVS_READ(SCALER_DISPDITHER);
+			HVS_WRITE(SCALER_DISPDITHER,
+				  (reg & ~SCALER_DISPDITHER_DSP5_MUX_MASK) |
+				  VC4_SET_FIELD(mux, SCALER_DISPDITHER_DSP5_MUX));
 			break;
 
 		default:
 			break;
 		}
 	}
-
-	reg = HVS_READ(SCALER_DISPECTRL);
-	HVS_WRITE(SCALER_DISPECTRL,
-		  (reg & ~SCALER_DISPECTRL_DSP2_MUX_MASK) |
-		  VC4_SET_FIELD(dsp2_mux, SCALER_DISPECTRL_DSP2_MUX));
-
-	reg = HVS_READ(SCALER_DISPCTRL);
-	HVS_WRITE(SCALER_DISPCTRL,
-		  (reg & ~SCALER_DISPCTRL_DSP3_MUX_MASK) |
-		  VC4_SET_FIELD(dsp3_mux, SCALER_DISPCTRL_DSP3_MUX));
-
-	reg = HVS_READ(SCALER_DISPEOLN);
-	HVS_WRITE(SCALER_DISPEOLN,
-		  (reg & ~SCALER_DISPEOLN_DSP4_MUX_MASK) |
-		  VC4_SET_FIELD(dsp4_mux, SCALER_DISPEOLN_DSP4_MUX));
-
-	reg = HVS_READ(SCALER_DISPDITHER);
-	HVS_WRITE(SCALER_DISPDITHER,
-		  (reg & ~SCALER_DISPDITHER_DSP5_MUX_MASK) |
-		  VC4_SET_FIELD(dsp5_mux, SCALER_DISPDITHER_DSP5_MUX));
 }
 
 static void
@@ -657,53 +689,123 @@ static int vc4_load_tracker_obj_init(struct vc4_dev *vc4)
 				    &load_state->base,
 				    &vc4_load_tracker_state_funcs);
 
-	return drmm_add_action(&vc4->base, vc4_load_tracker_obj_fini, NULL);
+	return drmm_add_action_or_reset(&vc4->base, vc4_load_tracker_obj_fini, NULL);
 }
 
-#define NUM_OUTPUTS  6
-#define NUM_CHANNELS 3
+static struct drm_private_state *
+vc4_hvs_channels_duplicate_state(struct drm_private_obj *obj)
+{
+	struct vc4_hvs_state *old_state = to_vc4_hvs_state(obj->state);
+	struct vc4_hvs_state *state;
+
+	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return NULL;
 
-static int
-vc4_atomic_check(struct drm_device *dev, struct drm_atomic_state *state)
+	__drm_atomic_helper_private_obj_duplicate_state(obj, &state->base);
+
+	state->unassigned_channels = old_state->unassigned_channels;
+
+	return &state->base;
+}
+
+static void vc4_hvs_channels_destroy_state(struct drm_private_obj *obj,
+					   struct drm_private_state *state)
 {
-	unsigned long unassigned_channels = GENMASK(NUM_CHANNELS - 1, 0);
-	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
-	struct drm_crtc *crtc;
-	int i, ret;
+	struct vc4_hvs_state *hvs_state = to_vc4_hvs_state(state);
 
-	/*
-	 * Since the HVS FIFOs are shared across all the pixelvalves and
-	 * the TXP (and thus all the CRTCs), we need to pull the current
-	 * state of all the enabled CRTCs so that an update to a single
-	 * CRTC still keeps the previous FIFOs enabled and assigned to
-	 * the same CRTCs, instead of evaluating only the CRTC being
-	 * modified.
-	 */
-	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
-		struct drm_crtc_state *crtc_state;
+	kfree(hvs_state);
+}
 
-		if (!crtc->state->enable)
-			continue;
+static const struct drm_private_state_funcs vc4_hvs_state_funcs = {
+	.atomic_duplicate_state = vc4_hvs_channels_duplicate_state,
+	.atomic_destroy_state = vc4_hvs_channels_destroy_state,
+};
 
-		crtc_state = drm_atomic_get_crtc_state(state, crtc);
-		if (IS_ERR(crtc_state))
-			return PTR_ERR(crtc_state);
-	}
+static void vc4_hvs_channels_obj_fini(struct drm_device *dev, void *unused)
+{
+	struct vc4_dev *vc4 = to_vc4_dev(dev);
+
+	drm_atomic_private_obj_fini(&vc4->hvs_channels);
+}
+
+static int vc4_hvs_channels_obj_init(struct vc4_dev *vc4)
+{
+	struct vc4_hvs_state *state;
+
+	state = kzalloc(sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return -ENOMEM;
+
+	state->unassigned_channels = GENMASK(HVS_NUM_CHANNELS - 1, 0);
+	drm_atomic_private_obj_init(&vc4->base, &vc4->hvs_channels,
+				    &state->base,
+				    &vc4_hvs_state_funcs);
+
+	return drmm_add_action_or_reset(&vc4->base, vc4_hvs_channels_obj_fini, NULL);
+}
+
+/*
+ * The BCM2711 HVS has up to 7 outputs connected to the pixelvalves and
+ * the TXP (and therefore all the CRTCs found on that platform).
+ *
+ * The naive (and our initial) implementation would just iterate over
+ * all the active CRTCs, try to find a suitable FIFO, and then remove it
+ * from the pool of available FIFOs. However, there are a few corner
+ * cases that need to be considered:
+ *
+ * - When running in a dual-display setup (so with two CRTCs involved),
+ *   we can update the state of a single CRTC (for example by changing
+ *   its mode using xrandr under X11) without affecting the other. In
+ *   this case, the other CRTC wouldn't be in the state at all, so we
+ *   need to consider all the running CRTCs in the DRM device to assign
+ *   a FIFO, not just the one in the state.
+ *
+ * - To fix the above, we can't use drm_atomic_get_crtc_state on all
+ *   enabled CRTCs to pull their CRTC state into the global state, since
+ *   a page flip would start considering their vblank to complete. Since
+ *   we don't have a guarantee that they are actually active, that
+ *   vblank might never happen, and shouldn't even be considered if we
+ *   want to do a page flip on a single CRTC. That can be tested by
+ *   doing a modetest -v first on HDMI1 and then on HDMI0.
+ *
+ * - Since we need the pixelvalve to be disabled and enabled back when
+ *   the FIFO is changed, we should keep the FIFO assigned for as long
+ *   as the CRTC is enabled, only considering it free again once that
+ *   CRTC has been disabled. This can be tested by booting X11 on a
+ *   single display, and changing the resolution down and then back up.
+ */
+static int vc4_pv_muxing_atomic_check(struct drm_device *dev,
+				      struct drm_atomic_state *state)
+{
+	struct vc4_hvs_state *hvs_new_state;
+	struct drm_crtc_state *old_crtc_state, *new_crtc_state;
+	struct drm_crtc *crtc;
+	unsigned int i;
+
+	hvs_new_state = vc4_hvs_get_global_state(state);
+	if (!hvs_new_state)
+		return -EINVAL;
 
 	for_each_oldnew_crtc_in_state(state, crtc, old_crtc_state, new_crtc_state, i) {
+		struct vc4_crtc_state *old_vc4_crtc_state =
+			to_vc4_crtc_state(old_crtc_state);
 		struct vc4_crtc_state *new_vc4_crtc_state =
 			to_vc4_crtc_state(new_crtc_state);
 		struct vc4_crtc *vc4_crtc = to_vc4_crtc(crtc);
 		unsigned int matching_channels;
 
-		if (old_crtc_state->enable && !new_crtc_state->enable)
-			new_vc4_crtc_state->assigned_channel = VC4_HVS_CHANNEL_DISABLED;
-
-		if (!new_crtc_state->enable)
+		/* Nothing to do here, let's skip it */
+		if (old_crtc_state->enable == new_crtc_state->enable)
 			continue;
 
-		if (new_vc4_crtc_state->assigned_channel != VC4_HVS_CHANNEL_DISABLED) {
-			unassigned_channels &= ~BIT(new_vc4_crtc_state->assigned_channel);
+		/* Muxing will need to be modified, mark it as such */
+		new_vc4_crtc_state->update_muxing = true;
+
+		/* If we're disabling our CRTC, we put back our channel */
+		if (!new_crtc_state->enable) {
+			hvs_new_state->unassigned_channels |= BIT(old_vc4_crtc_state->assigned_channel);
+			new_vc4_crtc_state->assigned_channel = VC4_HVS_CHANNEL_DISABLED;
 			continue;
 		}
 
@@ -731,17 +833,29 @@ vc4_atomic_check(struct drm_device *dev, struct drm_atomic_state *state)
 		 * the future, we will need to have something smarter,
 		 * but it works so far.
 		 */
-		matching_channels = unassigned_channels & vc4_crtc->data->hvs_available_channels;
+		matching_channels = hvs_new_state->unassigned_channels & vc4_crtc->data->hvs_available_channels;
 		if (matching_channels) {
 			unsigned int channel = ffs(matching_channels) - 1;
 
 			new_vc4_crtc_state->assigned_channel = channel;
-			unassigned_channels &= ~BIT(channel);
+			hvs_new_state->unassigned_channels &= ~BIT(channel);
 		} else {
 			return -EINVAL;
 		}
 	}
 
+	return 0;
+}
+
+static int
+vc4_atomic_check(struct drm_device *dev, struct drm_atomic_state *state)
+{
+	int ret;
+
+	ret = vc4_pv_muxing_atomic_check(dev, state);
+	if (ret)
+		return ret;
+
 	ret = vc4_ctm_atomic_check(dev, state);
 	if (ret < 0)
 		return ret;
@@ -808,6 +922,10 @@ int vc4_kms_load(struct drm_device *dev)
 	if (ret)
 		return ret;
 
+	ret = vc4_hvs_channels_obj_init(vc4);
+	if (ret)
+		return ret;
+
 	drm_mode_config_reset(dev);
 
 	drm_kms_helper_poll_init(dev);