drm/vgaarb: add VGA arbitration support to the drm and kms.

VGA arb requires DRM support for non-kms drivers, to turn on/off
irqs when disabling the mem/io regions.

VGA arb requires KMS support for GPUs where we can turn off VGA
decoding. Currently we know how to do this for intel and radeon
kms drivers, which allows them to be removed from the arbiter.

This patch comes from Fedora rawhide kernel.

Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 14 insertions, 0 deletions

diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c
index 5f42fad19190..eab31c1d6df1 100644
--- a/drivers/gpu/drm/radeon/r600.c
+++ b/drivers/gpu/drm/radeon/r600.c
@@ -1499,6 +1499,20 @@ int r600_startup(struct radeon_device *rdev)
         return 0;
 }
 
+void r600_vga_set_state(struct radeon_device *rdev, bool state)
+{
+        uint32_t temp;
+
+        temp = RREG32(CONFIG_CNTL);
+        if (state == false) {
+                temp &= ~(1<<0);
+                temp |= (1<<1);
+        } else {
+                temp &= ~(1<<1);
+        }
+        WREG32(CONFIG_CNTL, temp);
+}
+
 int r600_resume(struct radeon_device *rdev)
 {
         int r;