Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 26 insertions, 0 deletions

diff --git a/arch/x86/include/asm/agp.h b/arch/x86/include/asm/agp.h
new file mode 100644
index 0000000000..c8c111d8fb
--- /dev/null
+++ b/arch/x86/include/asm/agp.h
@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_AGP_H
+#define _ASM_X86_AGP_H
+
+#include <linux/pgtable.h>
+#include <asm/cacheflush.h>
+
+/*
+ * Functions to keep the agpgart mappings coherent with the MMU. The
+ * GART gives the CPU a physical alias of pages in memory. The alias
+ * region is mapped uncacheable. Make sure there are no conflicting
+ * mappings with different cacheability attributes for the same
+ * page. This avoids data corruption on some CPUs.
+ */
+
+#define map_page_into_agp(page) set_pages_uc(page, 1)
+#define unmap_page_from_agp(page) set_pages_wb(page, 1)
+
+/*
+ * Could use CLFLUSH here if the cpu supports it. But then it would
+ * need to be called for each cacheline of the whole page so it may
+ * not be worth it. Would need a page for it.
+ */
+#define flush_agp_cache() wbinvd()
+
+#endif /* _ASM_X86_AGP_H */