intel/agp: rewrite GTT on resume

On my Intel chipset (965GM), the GTT is entirely erased across
suspend/resume.  This patch simply re-plays the current mapping at resume
time to restore the table.=20

I noticed this once I started relying on persistent GTT mappings across VT
switch in our GEM work -- the old X server and DRM code carefully unbind
all memory from the GTT on VT switch, but GEM does not bother.

I placed the list management and rewrite code in the generic layer on the
assumption that it will be needed on other hardware, but I did not add the
rewrite call to anything other than the Intel resume function.

Keep a list of current GATT mappings.  At resume time, rewrite them into
the GATT.  This is needed on Intel (at least) as the entire GATT is
cleared across suspend/resume.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Keith Packard <keithp@keithp.com>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/agp_backend.h b/include/linux/agp_backend.h
index 972b12bcfb36..2b8df8b420fd 100644
--- a/include/linux/agp_backend.h
+++ b/include/linux/agp_backend.h
@@ -30,6 +30,8 @@
 #ifndef _AGP_BACKEND_H
 #define _AGP_BACKEND_H 1
 
+#include <linux/list.h>
+
 enum chipset_type {
         NOT_SUPPORTED,
         SUPPORTED,
@@ -78,6 +80,8 @@ struct agp_memory {
         bool is_bound;
         bool is_flushed;
         bool vmalloc_flag;
+        /* list of agp_memory mapped to the aperture */
+        struct list_head mapped_list;
 };
 
 #define AGP_NORMAL_MEMORY 0
@@ -96,6 +100,7 @@ extern struct agp_memory *agp_allocate_memory(struct agp_bridge_data *, size_t,
 extern int agp_copy_info(struct agp_bridge_data *, struct agp_kern_info *);
 extern int agp_bind_memory(struct agp_memory *, off_t);
 extern int agp_unbind_memory(struct agp_memory *);
+extern int agp_rebind_memory(void);
 extern void agp_enable(struct agp_bridge_data *, u32);
 extern struct agp_bridge_data *agp_backend_acquire(struct pci_dev *);
 extern void agp_backend_release(struct agp_bridge_data *);