1 files changed, 86 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h
new file mode 100644
index 000000000..1c99fcadb
--- /dev/null
+++ b/arch/arm64/include/asm/mte.h
@@ -0,0 +1,86 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020 ARM Ltd.
+ */
+#ifndef __ASM_MTE_H
+#define __ASM_MTE_H
+
+#define MTE_GRANULE_SIZE	UL(16)
+#define MTE_GRANULE_MASK	(~(MTE_GRANULE_SIZE - 1))
+#define MTE_TAG_SHIFT		56
+#define MTE_TAG_SIZE		4
+
+#ifndef __ASSEMBLY__
+
+#include <linux/page-flags.h>
+
+#include <asm/pgtable-types.h>
+
+void mte_clear_page_tags(void *addr);
+unsigned long mte_copy_tags_from_user(void *to, const void __user *from,
+				      unsigned long n);
+unsigned long mte_copy_tags_to_user(void __user *to, void *from,
+				    unsigned long n);
+int mte_save_tags(struct page *page);
+void mte_save_page_tags(const void *page_addr, void *tag_storage);
+bool mte_restore_tags(swp_entry_t entry, struct page *page);
+void mte_restore_page_tags(void *page_addr, const void *tag_storage);
+void mte_invalidate_tags(int type, pgoff_t offset);
+void mte_invalidate_tags_area(int type);
+void *mte_allocate_tag_storage(void);
+void mte_free_tag_storage(char *storage);
+
+#ifdef CONFIG_ARM64_MTE
+
+/* track which pages have valid allocation tags */
+#define PG_mte_tagged	PG_arch_2
+
+void mte_sync_tags(pte_t *ptep, pte_t pte);
+void mte_copy_page_tags(void *kto, const void *kfrom);
+void flush_mte_state(void);
+void mte_thread_switch(struct task_struct *next);
+void mte_suspend_exit(void);
+long set_mte_ctrl(struct task_struct *task, unsigned long arg);
+long get_mte_ctrl(struct task_struct *task);
+int mte_ptrace_copy_tags(struct task_struct *child, long request,
+			 unsigned long addr, unsigned long data);
+
+#else
+
+/* unused if !CONFIG_ARM64_MTE, silence the compiler */
+#define PG_mte_tagged	0
+
+static inline void mte_sync_tags(pte_t *ptep, pte_t pte)
+{
+}
+static inline void mte_copy_page_tags(void *kto, const void *kfrom)
+{
+}
+static inline void flush_mte_state(void)
+{
+}
+static inline void mte_thread_switch(struct task_struct *next)
+{
+}
+static inline void mte_suspend_exit(void)
+{
+}
+static inline long set_mte_ctrl(struct task_struct *task, unsigned long arg)
+{
+	return 0;
+}
+static inline long get_mte_ctrl(struct task_struct *task)
+{
+	return 0;
+}
+static inline int mte_ptrace_copy_tags(struct task_struct *child,
+				       long request, unsigned long addr,
+				       unsigned long data)
+{
+	return -EIO;
+}
+
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_MTE_H  */