agp/uninorth: Fix oops caused by flushing too much

This fixes a sporadic oops at boot on G5 Power Macs.  The table_end
variable has the address of the last byte of the table.  Adding on
PAGE_SIZE means we flush too much, and if the page after the table
is not mapped for any reason, the kernel will oops.  Instead we add
on 1 because flush_dcache_range() interprets its second argument as
the first byte past the range to be flushed.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/drivers/char/agp/uninorth-agp.c b/drivers/char/agp/uninorth-agp.c
index 95db71360d2416b437c0447c7ffd64b582ff6b5b..f845a8f718b39af2bd1277e331d50143e24ae9fc 100644 (file)
--- a/drivers/char/agp/uninorth-agp.c
+++ b/drivers/char/agp/uninorth-agp.c
@@ -415,7 +415,7 @@ static int uninorth_create_gatt_table(struct agp_bridge_data *bridge)
        bridge->gatt_table_real = (u32 *) table;
        /* Need to clear out any dirty data still sitting in caches */
        flush_dcache_range((unsigned long)table,
-                          (unsigned long)(table_end + PAGE_SIZE));
+                          (unsigned long)table_end + 1);
        bridge->gatt_table = vmap(pages, (1 << page_order), 0, PAGE_KERNEL_NCG);
 
        if (bridge->gatt_table == NULL)