Revert "fbdev: fbmem: add a helper to determine if an aperture is used by a fw fb"

This reverts commit 9a45ac23.

This was added a helper for amdgpu to workaround a runtime pm regression
caused by a runtime pm fix in efifb.  We now have a better workaround
in amdgpu in
commit f95af4a9 ("drm/amdgpu: don't runtime suspend if there are displays attached (v3)")
so this workaround is no longer necessary.  Since amdgpu was the only
user of this interface, we can remove it.
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/video/fbdev/core/fbmem.c

@@ -1783,53 +1783,6 @@ int remove_conflicting_framebuffers(struct apertures_struct *a,
 }
 EXPORT_SYMBOL(remove_conflicting_framebuffers);
 
-/**
- * is_firmware_framebuffer - detect if firmware-configured framebuffer matches
- * @a: memory range, users of which are to be checked
- *
- * This function checks framebuffer devices (initialized by firmware/bootloader)
- * which use memory range described by @a. If @a matchesm the function returns
- * true, otherwise false.
- */
-bool is_firmware_framebuffer(struct apertures_struct *a)
-{
-	bool do_free = false;
-	bool found = false;
-	int i;
-
-	if (!a) {
-		a = alloc_apertures(1);
-		if (!a)
-			return false;
-
-		a->ranges[0].base = 0;
-		a->ranges[0].size = ~0;
-		do_free = true;
-	}
-
-	mutex_lock(&registration_lock);
-	/* check all firmware fbs and kick off if the base addr overlaps */
-	for_each_registered_fb(i) {
-		struct apertures_struct *gen_aper;
-
-		if (!(registered_fb[i]->flags & FBINFO_MISC_FIRMWARE))
-			continue;
-
-		gen_aper = registered_fb[i]->apertures;
-		if (fb_do_apertures_overlap(gen_aper, a)) {
-			found = true;
-			break;
-		}
-	}
-	mutex_unlock(&registration_lock);
-
-	if (do_free)
-		kfree(a);
-
-	return found;
-}
-EXPORT_SYMBOL(is_firmware_framebuffer);
-
 /**
  * remove_conflicting_pci_framebuffers - remove firmware-configured framebuffers for PCI devices
  * @pdev: PCI device

include/linux/fb.h

@@ -612,7 +612,6 @@ extern int remove_conflicting_pci_framebuffers(struct pci_dev *pdev,
 					       const char *name);
 extern int remove_conflicting_framebuffers(struct apertures_struct *a,
 					   const char *name, bool primary);
-extern bool is_firmware_framebuffer(struct apertures_struct *a);
 extern int fb_prepare_logo(struct fb_info *fb_info, int rotate);
 extern int fb_show_logo(struct fb_info *fb_info, int rotate);
 extern char* fb_get_buffer_offset(struct fb_info *info, struct fb_pixmap *buf, u32 size);