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-rw-r--r--arch/x86/include/asm/agp.h32
1 files changed, 32 insertions, 0 deletions
diff --git a/arch/x86/include/asm/agp.h b/arch/x86/include/asm/agp.h
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+++ b/arch/x86/include/asm/agp.h
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+/* 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()
+
+/* GATT allocation. Returns/accepts GATT kernel virtual address. */
+#define alloc_gatt_pages(order) \
+ ((char *)__get_free_pages(GFP_KERNEL, (order)))
+#define free_gatt_pages(table, order) \
+ free_pages((unsigned long)(table), (order))
+
+#endif /* _ASM_X86_AGP_H */