drm: updated DRM map patch for 32/64 bit systems

I basically combined Paul's patches with additions that I had made
for PCI scatter gather.
I also tried more carefully to avoid problems with the same token
assigned multiple times while trying to use the base address in the
token if possible to gain as much backward compatibility as possible
for broken DRI clients.

From: Paul Mackerras <paulus@samba.org> and Egbert Eich <eich@suse.de>
Signed-off-by: Dave Airlie <airlied@linux.ie>

1 files changed, 9 insertions, 2 deletions

diff --git a/drivers/char/drm/drm_scatter.c b/drivers/char/drm/drm_scatter.c
index 54fddb6ea2d..ed267d49bc6 100644
--- a/drivers/char/drm/drm_scatter.c
+++ b/drivers/char/drm/drm_scatter.c
@@ -61,6 +61,12 @@ void drm_sg_cleanup( drm_sg_mem_t *entry )
                    DRM_MEM_SGLISTS );
 }
 
+#ifdef _LP64
+# define ScatterHandle(x) (unsigned int)((x >> 32) + (x & ((1L << 32) - 1)))
+#else
+# define ScatterHandle(x) (unsigned int)(x)
+#endif
+
 int drm_sg_alloc( struct inode *inode, struct file *filp,
                    unsigned int cmd, unsigned long arg )
 {
@@ -133,12 +139,13 @@ int drm_sg_alloc( struct inode *inode, struct file *filp,
          */
         memset( entry->virtual, 0, pages << PAGE_SHIFT );
 
-        entry->handle = (unsigned long)entry->virtual;
+        entry->handle = ScatterHandle((unsigned long)entry->virtual);
 
         DRM_DEBUG( "sg alloc handle  = %08lx\n", entry->handle );
         DRM_DEBUG( "sg alloc virtual = %p\n", entry->virtual );
 
-        for ( i = entry->handle, j = 0 ; j < pages ; i += PAGE_SIZE, j++ ) {
+        for (i = (unsigned long)entry->virtual, j = 0; j < pages; 
+                i += PAGE_SIZE, j++) {
                 entry->pagelist[j] = vmalloc_to_page((void *)i);
                 if (!entry->pagelist[j])
                         goto failed;