drm/i915/fbdev: Add intel_fbdev_get_map()

The vaddr of the fbdev framebuffer is private to the struct
intel_fbdev, so this function is needed to access it for drm_panic.
Also the struct i915_vma is different between i915 and xe, so it
requires a few functions to access fbdev->vma->iomap.

Signed-off-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://lore.kernel.org/r/20250624091501.257661-3-jfalempe@redhat.com
Signed-off-by: Maarten Lankhorst <dev@lankhorst.se>

Author: Jocelyn Falempe

drivers/gpu/drm/i915/display/intel_fb_pin.c

@@ -334,3 +334,8 @@ void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state)
 			intel_dpt_unpin_from_ggtt(fb->dpt_vm);
 	}
 }
+
+void intel_fb_get_map(struct i915_vma *vma, struct iosys_map *map)
+{
+	iosys_map_set_vaddr_iomem(map, i915_vma_get_iomap(vma));
+}

drivers/gpu/drm/i915/display/intel_fb_pin.h

@@ -12,6 +12,7 @@ struct drm_framebuffer;
 struct i915_vma;
 struct intel_plane_state;
 struct i915_gtt_view;
+struct iosys_map;
 
 struct i915_vma *
 intel_fb_pin_to_ggtt(const struct drm_framebuffer *fb,
@@ -27,5 +28,6 @@ void intel_fb_unpin_vma(struct i915_vma *vma, unsigned long flags);
 int intel_plane_pin_fb(struct intel_plane_state *new_plane_state,
 		       const struct intel_plane_state *old_plane_state);
 void intel_plane_unpin_fb(struct intel_plane_state *old_plane_state);
+void intel_fb_get_map(struct i915_vma *vma, struct iosys_map *map);
 
 #endif

drivers/gpu/drm/i915/display/intel_fbdev.c

@@ -512,3 +512,8 @@ struct i915_vma *intel_fbdev_vma_pointer(struct intel_fbdev *fbdev)
 {
 	return fbdev ? fbdev->vma : NULL;
 }
+
+void intel_fbdev_get_map(struct intel_fbdev *fbdev, struct iosys_map *map)
+{
+	intel_fb_get_map(fbdev->vma, map);
+}

drivers/gpu/drm/i915/display/intel_fbdev.h

@@ -13,6 +13,7 @@ struct drm_fb_helper_surface_size;
 struct intel_display;
 struct intel_fbdev;
 struct intel_framebuffer;
+struct iosys_map;
 
 #ifdef CONFIG_DRM_FBDEV_EMULATION
 int intel_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
@@ -22,7 +23,7 @@ int intel_fbdev_driver_fbdev_probe(struct drm_fb_helper *helper,
 void intel_fbdev_setup(struct intel_display *display);
 struct intel_framebuffer *intel_fbdev_framebuffer(struct intel_fbdev *fbdev);
 struct i915_vma *intel_fbdev_vma_pointer(struct intel_fbdev *fbdev);
-
+void intel_fbdev_get_map(struct intel_fbdev *fbdev, struct iosys_map *map);
 #else
 #define INTEL_FBDEV_DRIVER_OPS \
 	.fbdev_probe = NULL
@@ -39,6 +40,9 @@ static inline struct i915_vma *intel_fbdev_vma_pointer(struct intel_fbdev *fbdev
 	return NULL;
 }
 
+static inline void intel_fbdev_get_map(struct intel_fbdev *fbdev, struct iosys_map *map)
+{
+}
 #endif
 
 #endif /* __INTEL_FBDEV_H__ */

drivers/gpu/drm/i915/i915_vma.h

@@ -353,6 +353,11 @@ static inline bool i915_node_color_differs(const struct drm_mm_node *node,
 	return drm_mm_node_allocated(node) && node->color != color;
 }
 
+static inline void __iomem *i915_vma_get_iomap(struct i915_vma *vma)
+{
+	return READ_ONCE(vma->iomap);
+}
+
 /**
  * i915_vma_pin_iomap - calls ioremap_wc to map the GGTT VMA via the aperture
  * @vma: VMA to iomap

drivers/gpu/drm/xe/display/xe_fb_pin.c

@@ -457,3 +457,8 @@ u64 intel_dpt_offset(struct i915_vma *dpt_vma)
 {
 	return 0;
 }
+
+void intel_fb_get_map(struct i915_vma *vma, struct iosys_map *map)
+{
+	*map = vma->bo->vmap;
+}