agp: add chipset flushing support to AGP interface

This bumps the AGP interface to 0.103.

Certain Intel chipsets contains a global write buffer, and this can require
flushing from the drm or X.org to make sure all data has hit RAM before
initiating a GPU transfer, due to a lack of coherency with the integrated
graphics device and this buffer.

This just adds generic support to the AGP interfaces, a follow-on patch
will add support to the Intel driver to use this interface.

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

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index 1a4674ce0c71..7484bc759c4c 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -80,6 +80,13 @@ static int agp_get_key(void)
         return -1;
 }
 
+void agp_flush_chipset(struct agp_bridge_data *bridge)
+{
+        if (bridge->driver->chipset_flush)
+                bridge->driver->chipset_flush(bridge);
+}
+EXPORT_SYMBOL(agp_flush_chipset);
+
 /*
  * Use kmalloc if possible for the page list. Otherwise fall back to
  * vmalloc. This speeds things up and also saves memory for small AGP