drm/i915: Walk crtcs in pipe order

Currently our crtcs are registered in pipe order, and thus
all the for_intel_crtc*() iterators walk the crtcs in pipe
order. There are a bunch of places that more or less depend
on that. Eg. during plane updates and such we want joined
pipes to be processed back-to-back to give a better chance
of an atomic update across the whole set.

When we start to register crtcs in a different order we don't
want to change the order in which the pipes get handled.
Decouple the for_each_intel_crtc*() iterators from the crtc
registration order by using a separate list which will be
sorted by the pipe rather than the crtc index.

We could probably use a simple array or something, but that
would require some kind of extra iterator variable for the
macros, and thus would require a lot more changes. Using
a linked list keeps the fallout minimal. We can look at
using a more optimal data structure later.

I also added this extra junk to the atomic state iterators:
"(__i) = drm_crtc_index(&(crtc)->base), (void)(__i)"
even though the macro itself no longer needs the "__i" iterator.
This in case the "__i" is used by the caller, and to
avoid compiler warnings if it's completely unused now.

v2: Flip the pipe comparison (Jani)

Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260408155744.13326-3-ville.syrjala@linux.intel.com
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

6 files changed, 64 insertions, 52 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_crtc.c b/drivers/gpu/drm/i915/display/intel_crtc.c
index b8189cd5d864..c88a6810c49f 100644
--- a/drivers/gpu/drm/i915/display/intel_crtc.c
+++ b/drivers/gpu/drm/i915/display/intel_crtc.c
@@ -209,6 +209,8 @@ static struct intel_crtc *intel_crtc_alloc(void)
 	crtc->base.state = &crtc_state->uapi;
 	crtc->config = crtc_state;
 
+	INIT_LIST_HEAD(&crtc->pipe_head);
+
 	return crtc;
 }
 
@@ -222,6 +224,8 @@ static void intel_crtc_destroy(struct drm_crtc *_crtc)
 {
 	struct intel_crtc *crtc = to_intel_crtc(_crtc);
 
+	list_del(&crtc->pipe_head);
+
 	cpu_latency_qos_remove_request(&crtc->vblank_pm_qos);
 
 	drm_crtc_cleanup(&crtc->base);
@@ -308,6 +312,20 @@ static const struct drm_crtc_funcs i8xx_crtc_funcs = {
 	.get_vblank_timestamp = intel_crtc_get_vblank_timestamp,
 };
 
+static void add_crtc_to_pipe_list(struct intel_display *display, struct intel_crtc *crtc)
+{
+	struct intel_crtc *iter;
+
+	list_for_each_entry(iter, &display->pipe_list, pipe_head) {
+		if (crtc->pipe < iter->pipe) {
+			list_add_tail(&crtc->pipe_head, &iter->pipe_head);
+			return;
+		}
+	}
+
+	list_add_tail(&crtc->pipe_head, &display->pipe_list);
+}
+
 static int __intel_crtc_init(struct intel_display *display, enum pipe pipe)
 {
 	struct intel_plane *primary, *cursor;
@@ -398,6 +416,8 @@ static int __intel_crtc_init(struct intel_display *display, enum pipe pipe)
 	if (HAS_CASF(display) && crtc->num_scalers >= 2)
 		drm_crtc_create_sharpness_strength_property(&crtc->base);
 
+	add_crtc_to_pipe_list(display, crtc);
+
 	return 0;
 
 fail:
diff --git a/drivers/gpu/drm/i915/display/intel_display.h b/drivers/gpu/drm/i915/display/intel_display.h
index 552a59d19e0f..1e76a455d7c4 100644
--- a/drivers/gpu/drm/i915/display/intel_display.h
+++ b/drivers/gpu/drm/i915/display/intel_display.h
@@ -212,22 +212,23 @@ enum phy_fia {
 			    base.head)					\
 		for_each_if((intel_plane)->pipe == (intel_crtc)->pipe)
 
-#define for_each_intel_crtc(dev, intel_crtc)				\
-	list_for_each_entry(intel_crtc,					\
-			    &(dev)->mode_config.crtc_list,		\
-			    base.head)
+#define for_each_intel_crtc(dev, crtc) \
+	list_for_each_entry((crtc), \
+			    &to_intel_display(dev)->pipe_list, \
+			    pipe_head)
 
-#define for_each_intel_crtc_in_pipe_mask(dev, intel_crtc, pipe_mask)	\
-	list_for_each_entry(intel_crtc,					\
-			    &(dev)->mode_config.crtc_list,		\
-			    base.head)					\
-		for_each_if((pipe_mask) & BIT(intel_crtc->pipe))
+#define for_each_intel_crtc_reverse(dev, crtc) \
+	list_for_each_entry_reverse((crtc), \
+				    &to_intel_display(dev)->pipe_list, \
+				    pipe_head)
+
+#define for_each_intel_crtc_in_pipe_mask(dev, crtc, pipe_mask) \
+	for_each_intel_crtc((dev), (crtc)) \
+		for_each_if((pipe_mask) & BIT((crtc)->pipe))
 
-#define for_each_intel_crtc_in_pipe_mask_reverse(dev, intel_crtc, pipe_mask)	\
-	list_for_each_entry_reverse((intel_crtc),				\
-				    &(dev)->mode_config.crtc_list,		\
-				    base.head)					\
-		for_each_if((pipe_mask) & BIT((intel_crtc)->pipe))
+#define for_each_intel_crtc_in_pipe_mask_reverse(dev, crtc, pipe_mask) \
+	for_each_intel_crtc_reverse((dev), (crtc)) \
+		for_each_if((pipe_mask) & BIT((crtc)->pipe))
 
 #define for_each_intel_encoder(dev, intel_encoder)		\
 	list_for_each_entry(intel_encoder,			\
@@ -269,14 +270,6 @@ enum phy_fia {
 	     (__i)++) \
 		for_each_if(plane)
 
-#define for_each_old_intel_crtc_in_state(__state, crtc, old_crtc_state, __i) \
-	for ((__i) = 0; \
-	     (__i) < (__state)->base.dev->mode_config.num_crtc && \
-		     ((crtc) = to_intel_crtc((__state)->base.crtcs[__i].ptr), \
-		      (old_crtc_state) = to_intel_crtc_state((__state)->base.crtcs[__i].old_state), 1); \
-	     (__i)++) \
-		for_each_if(crtc)
-
 #define for_each_new_intel_plane_in_state(__state, plane, new_plane_state, __i) \
 	for ((__i) = 0; \
 	     (__i) < (__state)->base.dev->mode_config.num_total_plane && \
@@ -285,22 +278,6 @@ enum phy_fia {
 	     (__i)++) \
 		for_each_if(plane)
 
-#define for_each_new_intel_crtc_in_state(__state, crtc, new_crtc_state, __i) \
-	for ((__i) = 0; \
-	     (__i) < (__state)->base.dev->mode_config.num_crtc && \
-		     ((crtc) = to_intel_crtc((__state)->base.crtcs[__i].ptr), \
-		      (new_crtc_state) = to_intel_crtc_state((__state)->base.crtcs[__i].new_state), 1); \
-	     (__i)++) \
-		for_each_if(crtc)
-
-#define for_each_new_intel_crtc_in_state_reverse(__state, crtc, new_crtc_state, __i) \
-	for ((__i) = (__state)->base.dev->mode_config.num_crtc - 1; \
-	     (__i) >= 0  && \
-	     ((crtc) = to_intel_crtc((__state)->base.crtcs[__i].ptr), \
-	      (new_crtc_state) = to_intel_crtc_state((__state)->base.crtcs[__i].new_state), 1); \
-	     (__i)--) \
-		for_each_if(crtc)
-
 #define for_each_oldnew_intel_plane_in_state(__state, plane, old_plane_state, new_plane_state, __i) \
 	for ((__i) = 0; \
 	     (__i) < (__state)->base.dev->mode_config.num_total_plane && \
@@ -310,23 +287,32 @@ enum phy_fia {
 	     (__i)++) \
 		for_each_if(plane)
 
+#define for_each_old_intel_crtc_in_state(__state, crtc, old_crtc_state, __i) \
+	for_each_intel_crtc((__state)->base.dev, (crtc)) \
+		for_each_if(((__i) = drm_crtc_index(&(crtc)->base), (void)(__i), \
+			     (old_crtc_state) = intel_atomic_get_old_crtc_state((__state), (crtc))))
+
+#define for_each_new_intel_crtc_in_state(__state, crtc, new_crtc_state, __i) \
+	for_each_intel_crtc((__state)->base.dev, (crtc)) \
+		for_each_if(((__i) = drm_crtc_index(&(crtc)->base), (void)(__i), \
+			     (new_crtc_state) = intel_atomic_get_new_crtc_state((__state), (crtc))))
+
+#define for_each_new_intel_crtc_in_state_reverse(__state, crtc, new_crtc_state, __i) \
+	for_each_intel_crtc_reverse((__state)->base.dev, (crtc)) \
+		for_each_if(((__i) = drm_crtc_index(&(crtc)->base), (void)(__i), \
+			     (new_crtc_state) = intel_atomic_get_new_crtc_state((__state), (crtc))))
+
 #define for_each_oldnew_intel_crtc_in_state(__state, crtc, old_crtc_state, new_crtc_state, __i) \
-	for ((__i) = 0; \
-	     (__i) < (__state)->base.dev->mode_config.num_crtc && \
-		     ((crtc) = to_intel_crtc((__state)->base.crtcs[__i].ptr), \
-		      (old_crtc_state) = to_intel_crtc_state((__state)->base.crtcs[__i].old_state), \
-		      (new_crtc_state) = to_intel_crtc_state((__state)->base.crtcs[__i].new_state), 1); \
-	     (__i)++) \
-		for_each_if(crtc)
+	for_each_intel_crtc((__state)->base.dev, (crtc)) \
+		for_each_if(((__i) = drm_crtc_index(&(crtc)->base), (void)(__i), \
+			     (old_crtc_state) = intel_atomic_get_old_crtc_state((__state), (crtc)), \
+			     (new_crtc_state) = intel_atomic_get_new_crtc_state((__state), (crtc))))
 
 #define for_each_oldnew_intel_crtc_in_state_reverse(__state, crtc, old_crtc_state, new_crtc_state, __i) \
-	for ((__i) = (__state)->base.dev->mode_config.num_crtc - 1; \
-	     (__i) >= 0  && \
-	     ((crtc) = to_intel_crtc((__state)->base.crtcs[__i].ptr), \
-	      (old_crtc_state) = to_intel_crtc_state((__state)->base.crtcs[__i].old_state), \
-	      (new_crtc_state) = to_intel_crtc_state((__state)->base.crtcs[__i].new_state), 1); \
-	     (__i)--) \
-		for_each_if(crtc)
+	for_each_intel_crtc_reverse((__state)->base.dev, (crtc)) \
+		for_each_if(((__i) = drm_crtc_index(&(crtc)->base), (void)(__i), \
+			     (old_crtc_state) = intel_atomic_get_old_crtc_state((__state), (crtc)), \
+			     (new_crtc_state) = intel_atomic_get_new_crtc_state((__state), (crtc))))
 
 #define intel_atomic_crtc_state_for_each_plane_state( \
 		  plane, plane_state, \
diff --git a/drivers/gpu/drm/i915/display/intel_display_core.h b/drivers/gpu/drm/i915/display/intel_display_core.h
index d708d322aa85..d9baca2d5aaf 100644
--- a/drivers/gpu/drm/i915/display/intel_display_core.h
+++ b/drivers/gpu/drm/i915/display/intel_display_core.h
@@ -294,6 +294,9 @@ struct intel_display {
 	/* Parent, or core, driver functions exposed to display */
 	const struct intel_display_parent_interface *parent;
 
+	/* list of all intel_crtcs sorted by pipe */
+	struct list_head pipe_list;
+
 	/* Display functions */
 	struct {
 		/* Top level crtc-ish functions */
diff --git a/drivers/gpu/drm/i915/display/intel_display_driver.c b/drivers/gpu/drm/i915/display/intel_display_driver.c
index 23bfecc983e8..9c2f7ad6c7b7 100644
--- a/drivers/gpu/drm/i915/display/intel_display_driver.c
+++ b/drivers/gpu/drm/i915/display/intel_display_driver.c
@@ -117,6 +117,7 @@ static void intel_mode_config_init(struct intel_display *display)
 
 	drm_mode_config_init(display->drm);
 	INIT_LIST_HEAD(&display->global.obj_list);
+	INIT_LIST_HEAD(&display->pipe_list);
 
 	mode_config->min_width = 0;
 	mode_config->min_height = 0;
diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
index e2496db1642a..f6cd0a062090 100644
--- a/drivers/gpu/drm/i915/display/intel_display_types.h
+++ b/drivers/gpu/drm/i915/display/intel_display_types.h
@@ -1484,6 +1484,7 @@ struct intel_flipq {
 
 struct intel_crtc {
 	struct drm_crtc base;
+	struct list_head pipe_head;
 	enum pipe pipe;
 	/*
 	 * Whether the crtc and the connected output pipeline is active. Implies
diff --git a/drivers/gpu/drm/xe/display/xe_display.c b/drivers/gpu/drm/xe/display/xe_display.c
index a0a4ddf3bb46..00dfa68af29a 100644
--- a/drivers/gpu/drm/xe/display/xe_display.c
+++ b/drivers/gpu/drm/xe/display/xe_display.c
@@ -21,6 +21,7 @@
 #include "intel_audio.h"
 #include "intel_bw.h"
 #include "intel_display.h"
+#include "intel_display_core.h"
 #include "intel_display_device.h"
 #include "intel_display_driver.h"
 #include "intel_display_irq.h"