drm/i915/display: Add drm_panic support

This adds drm_panic support for a wide range of Intel GPU. I've
tested it only on 4 laptops, Haswell (with 128MB of eDRAM),
Comet Lake, Raptor Lake, and Lunar Lake.
For hardware using DPT, it's not possible to disable tiling, as you
will need to reconfigure the way the GPU is accessing the
framebuffer, so this will be handled by the following patches.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250624091501.257661-9-jfalempe@redhat.com
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>

1 files changed, 82 insertions, 1 deletions

diff --git a/drivers/gpu/drm/i915/display/intel_plane.c b/drivers/gpu/drm/i915/display/intel_plane.c
index 7c28ef677107..3271b70fde2e 100644
--- a/drivers/gpu/drm/i915/display/intel_plane.c
+++ b/drivers/gpu/drm/i915/display/intel_plane.c
@@ -33,18 +33,22 @@
 
 #include <linux/dma-fence-chain.h>
 #include <linux/dma-resv.h>
+#include <linux/iosys-map.h>
 
 #include <drm/drm_atomic_helper.h>
 #include <drm/drm_blend.h>
+#include <drm/drm_cache.h>
 #include <drm/drm_damage_helper.h>
 #include <drm/drm_fourcc.h>
 #include <drm/drm_gem.h>
 #include <drm/drm_gem_atomic_helper.h>
+#include <drm/drm_panic.h>
 
 #include "gem/i915_gem_object.h"
 #include "i915_scheduler_types.h"
 #include "i915_vma.h"
 #include "i9xx_plane_regs.h"
+#include "intel_bo.h"
 #include "intel_cdclk.h"
 #include "intel_cursor.h"
 #include "intel_display_rps.h"
@@ -52,6 +56,7 @@
 #include "intel_display_types.h"
 #include "intel_fb.h"
 #include "intel_fb_pin.h"
+#include "intel_fbdev.h"
 #include "intel_plane.h"
 #include "skl_scaler.h"
 #include "skl_universal_plane.h"
@@ -1267,14 +1272,90 @@ intel_cleanup_plane_fb(struct drm_plane *plane,
 	intel_plane_unpin_fb(old_plane_state);
 }
 
+static void intel_panic_flush(struct drm_plane *plane)
+{
+	struct intel_plane_state *plane_state = to_intel_plane_state(plane->state);
+	struct intel_plane *iplane = to_intel_plane(plane);
+	struct intel_display *display = to_intel_display(iplane);
+	struct drm_framebuffer *fb = plane_state->hw.fb;
+	struct intel_framebuffer *intel_fb = to_intel_framebuffer(fb);
+
+	intel_bo_panic_finish(intel_fb);
+
+	/* Flush the cache and don't disable tiling if it's the fbdev framebuffer.*/
+	if (intel_fb == intel_fbdev_framebuffer(display->fbdev.fbdev)) {
+		struct iosys_map map;
+
+		intel_fbdev_get_map(display->fbdev.fbdev, &map);
+		drm_clflush_virt_range(map.vaddr, fb->pitches[0] * fb->height);
+		return;
+	}
+
+	if (fb->modifier && iplane->disable_tiling)
+		iplane->disable_tiling(iplane);
+}
+
+static int intel_get_scanout_buffer(struct drm_plane *plane,
+				    struct drm_scanout_buffer *sb)
+{
+	struct intel_plane_state *plane_state;
+	struct drm_gem_object *obj;
+	struct drm_framebuffer *fb;
+	struct intel_framebuffer *intel_fb;
+	struct intel_display *display = to_intel_display(plane->dev);
+
+	if (!plane->state || !plane->state->fb || !plane->state->visible)
+		return -ENODEV;
+
+	plane_state = to_intel_plane_state(plane->state);
+	fb = plane_state->hw.fb;
+	intel_fb = to_intel_framebuffer(fb);
+
+	obj = intel_fb_bo(fb);
+	if (!obj)
+		return -ENODEV;
+
+	if (intel_fb == intel_fbdev_framebuffer(display->fbdev.fbdev)) {
+		intel_fbdev_get_map(display->fbdev.fbdev, &sb->map[0]);
+	} else {
+		int ret;
+		/* Can't disable tiling if DPT is in use */
+		if (intel_fb_uses_dpt(fb))
+			return -EOPNOTSUPP;
+		sb->private = intel_fb;
+		ret = intel_bo_panic_setup(sb);
+		if (ret)
+			return ret;
+	}
+	sb->width = fb->width;
+	sb->height = fb->height;
+	/* Use the generic linear format, because tiling, RC, CCS, CC
+	 * will be disabled in disable_tiling()
+	 */
+	sb->format = drm_format_info(fb->format->format);
+	sb->pitch[0] = fb->pitches[0];
+
+	return 0;
+}
+
 static const struct drm_plane_helper_funcs intel_plane_helper_funcs = {
 	.prepare_fb = intel_prepare_plane_fb,
 	.cleanup_fb = intel_cleanup_plane_fb,
 };
 
+static const struct drm_plane_helper_funcs intel_primary_plane_helper_funcs = {
+	.prepare_fb = intel_prepare_plane_fb,
+	.cleanup_fb = intel_cleanup_plane_fb,
+	.get_scanout_buffer = intel_get_scanout_buffer,
+	.panic_flush = intel_panic_flush,
+};
+
 void intel_plane_helper_add(struct intel_plane *plane)
 {
-	drm_plane_helper_add(&plane->base, &intel_plane_helper_funcs);
+	if (plane->base.type == DRM_PLANE_TYPE_PRIMARY)
+		drm_plane_helper_add(&plane->base, &intel_primary_plane_helper_funcs);
+	else
+		drm_plane_helper_add(&plane->base, &intel_plane_helper_funcs);
 }
 
 void intel_plane_init_cursor_vblank_work(struct intel_plane_state *old_plane_state,