fix historic ioremap() abuse in AGP
Several AGP drivers right now use ioremap_nocache() on kernel ram in order
to turn a page of regular memory uncached.
There are two problems with this:
1) This is a total nightmare for the ioremap() implementation to keep
various mappings of the same page coherent.
2) It's a total nightmare for the AGP code since it adds a ton of
complexity in terms of keeping track of 2 different pointers to
the same thing, in terms of error handling etc etc.
This patch fixes this by making the AGP drivers use the new
set_memory_XX APIs instead.
Note: amd-k7-agp.c is built on Alpha too, and generic.c is built
on ia64 as well, which do not yet have the set_memory_*() APIs,
so for them some we have a few ugly #ifdefs - hopefully they'll
be fixed soon.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Dave Airlie <airlied@linux.ie>
diff --git a/drivers/char/agp/generic.c b/drivers/char/agp/generic.c
index 7484bc7..7fc0c99 100644
--- a/drivers/char/agp/generic.c
+++ b/drivers/char/agp/generic.c
@@ -932,9 +932,14 @@
agp_gatt_table = (void *)table;
bridge->driver->cache_flush();
+#ifdef CONFIG_X86
+ set_memory_uc((unsigned long)table, 1 << page_order);
+ bridge->gatt_table = (void *)table;
+#else
bridge->gatt_table = ioremap_nocache(virt_to_gart(table),
(PAGE_SIZE * (1 << page_order)));
bridge->driver->cache_flush();
+#endif
if (bridge->gatt_table == NULL) {
for (page = virt_to_page(table); page <= virt_to_page(table_end); page++)
@@ -991,7 +996,11 @@
* called, then all agp memory is deallocated and removed
* from the table. */
+#ifdef CONFIG_X86
+ set_memory_wb((unsigned long)bridge->gatt_table, 1 << page_order);
+#else
iounmap(bridge->gatt_table);
+#endif
table = (char *) bridge->gatt_table_real;
table_end = table + ((PAGE_SIZE * (1 << page_order)) - 1);