dix: add ability to link output slave gpus to the current gpu (v1.1)

Just add the interfaces to attach/detach output slaves, and
a linked list to keep track of them. Hook up the randr providers
list to include these slaves.

v1.1: add another assert to the add path.

Reviewed-by: Keith Packard <keithp@keithp.com>
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/dix/dispatch.c b/dix/dispatch.c
index 9e8462124..29ac5a45a 100644
--- a/dix/dispatch.c
+++ b/dix/dispatch.c
@@ -3743,6 +3743,7 @@ static int init_screen(ScreenPtr pScreen, int i, Bool gpu)
     pScreen->CreateScreenResources = 0;
 
     xorg_list_init(&pScreen->unattached_list);
+    xorg_list_init(&pScreen->output_slave_list);
 
     /*
      * This loop gets run once for every Screen that gets added,
@@ -3909,3 +3910,19 @@ DetachUnboundGPU(ScreenPtr slave)
     slave->current_master = NULL;
 }
 
+void
+AttachOutputGPU(ScreenPtr pScreen, ScreenPtr new)
+{
+    assert(new->isGPU);
+    assert(!new->current_master);
+    xorg_list_add(&new->output_head, &pScreen->output_slave_list);
+    new->current_master = pScreen;
+}
+
+void
+DetachOutputGPU(ScreenPtr slave)
+{
+    assert(slave->isGPU);
+    xorg_list_del(&slave->output_head);
+    slave->current_master = NULL;
+}