fbdev: add support for handoff from firmware to hw framebuffers

With KMS we have ran into an issue where we really want the KMS fb driver
to be the one running the console, so panics etc can be shown by switching
out of X etc.

However with vesafb/efifb built-in, we end up with those on fb0 and the
KMS fb driver on fb1, driving the same piece of hw, so this adds an fb
info flag to denote a firmware fbdev, and adds a new aperture base/size
range which can be compared when the hw drivers are installed to see if
there is a conflict with a firmware driver, and if there is the firmware
driver is unregistered and the hw driver takes over.

It uses new aperture_base/size members instead of comparing on the fix
smem_start/length, as smem_start/length might for example only cover the
first 1MB of the PCI aperture, and we could allocate the kms fb from 8MB
into the aperture, thus they would never overlap.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Dave Airlie <airlied@redhat.com>
Acked-by: Peter Jones <pjones@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 14 insertions, 1 deletions

diff --git a/drivers/video/vesafb.c b/drivers/video/vesafb.c
index d6856f43d241..bd37ee1f6a25 100644
--- a/drivers/video/vesafb.c
+++ b/drivers/video/vesafb.c
@@ -174,8 +174,17 @@ static int vesafb_setcolreg(unsigned regno, unsigned red, unsigned green,
 	return err;
 }
 
+static void vesafb_destroy(struct fb_info *info)
+{
+	if (info->screen_base)
+		iounmap(info->screen_base);
+	release_mem_region(info->aperture_base, info->aperture_size);
+	framebuffer_release(info);
+}
+
 static struct fb_ops vesafb_ops = {
 	.owner		= THIS_MODULE,
+	.fb_destroy     = vesafb_destroy,
 	.fb_setcolreg	= vesafb_setcolreg,
 	.fb_pan_display	= vesafb_pan_display,
 	.fb_fillrect	= cfb_fillrect,
@@ -286,6 +295,10 @@ static int __init vesafb_probe(struct platform_device *dev)
 	info->pseudo_palette = info->par;
 	info->par = NULL;
 
+	/* set vesafb aperture size for generic probing */
+	info->aperture_base = screen_info.lfb_base;
+	info->aperture_size = size_total;
+
 	info->screen_base = ioremap(vesafb_fix.smem_start, vesafb_fix.smem_len);
 	if (!info->screen_base) {
 		printk(KERN_ERR
@@ -437,7 +450,7 @@ static int __init vesafb_probe(struct platform_device *dev)
 	info->fbops = &vesafb_ops;
 	info->var = vesafb_defined;
 	info->fix = vesafb_fix;
-	info->flags = FBINFO_FLAG_DEFAULT |
+	info->flags = FBINFO_FLAG_DEFAULT | FBINFO_MISC_FIRMWARE |
 		(ypan ? FBINFO_HWACCEL_YPAN : 0);
 
 	if (!ypan)