[PATCH v2 4/6] drm/radeon: Implement the is_boot_device callback function

[Sui Jingfeng <sui.jingfeng@linux.dev>]

From: Sui Jingfeng <suijingfeng@loongson.cn>

[why]

The vga_is_firmware_default() defined in drivers/pci/vgaarb.c is
arch-dependent, it's a dummy on non-x86 architectures currently.
This made VGAARB lost an important condition for the arbitration.
It could still be wrong even if we remove the #ifdef and #endif guards.
because the PCI bar will move (resource re-allocation).

[how]

The device that owns the firmware framebuffer should be the default boot
device. This patch adds an arch-independent function to enforce this rule.
The vgaarb subsystem will call back to radeon_is_boot_device() function
when drm/radeon is successfully bound to a radeon GPU device.

Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: Christian Konig <christian.koenig@amd.com>
Cc: Pan Xinhui <Xinhui.Pan@amd.com>
Cc: David Airlie <airlied@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Sui Jingfeng <suijingfeng@loongson.cn>
---
 drivers/gpu/drm/radeon/radeon_device.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/radeon/radeon_device.c b/drivers/gpu/drm/radeon/radeon_device.c
index 71f2ff39d6a1..afb49000830c 100644
--- a/drivers/gpu/drm/radeon/radeon_device.c
+++ b/drivers/gpu/drm/radeon/radeon_device.c
@@ -34,6 +34,7 @@
 #include <linux/vga_switcheroo.h>
 #include <linux/vgaarb.h>
 
+#include <drm/drm_aperture.h>
 #include <drm/drm_cache.h>
 #include <drm/drm_crtc_helper.h>
 #include <drm/drm_device.h>
@@ -1263,6 +1264,15 @@ static const struct vga_switcheroo_client_ops radeon_switcheroo_ops = {
 	.can_switch = radeon_switcheroo_can_switch,
 };
 
+static bool radeon_is_boot_device(struct pci_dev *pdev)
+{
+	struct drm_device *dev = pci_get_drvdata(pdev);
+	struct radeon_device *rdev = dev->dev_private;
+	struct radeon_mc *gmc = &rdev->mc;
+
+	return drm_aperture_contain_firmware_fb(gmc->aper_base, gmc->aper_size);
+}
+
 /**
  * radeon_device_init - initialize the driver
  *
@@ -1425,7 +1435,7 @@ int radeon_device_init(struct radeon_device *rdev,
 	/* if we have > 1 VGA cards, then disable the radeon VGA resources */
 	/* this will fail for cards that aren't VGA class devices, just
 	 * ignore it */
-	vga_client_register(rdev->pdev, radeon_vga_set_decode, NULL);
+	vga_client_register(rdev->pdev, radeon_vga_set_decode, radeon_is_boot_device);
 
 	if (rdev->flags & RADEON_IS_PX)
 		runtime = true;
-- 
2.25.1