xref: /openbmc/linux/include/linux/secretmem.h (revision 43fad1d0)
1 /* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
2 #ifndef _LINUX_SECRETMEM_H
3 #define _LINUX_SECRETMEM_H
4 
5 #ifdef CONFIG_SECRETMEM
6 
7 extern const struct address_space_operations secretmem_aops;
8 
folio_is_secretmem(struct folio * folio)9 static inline bool folio_is_secretmem(struct folio *folio)
10 {
11 	struct address_space *mapping;
12 
13 	/*
14 	 * Using folio_mapping() is quite slow because of the actual call
15 	 * instruction.
16 	 * We know that secretmem pages are not compound, so we can
17 	 * save a couple of cycles here.
18 	 */
19 	if (folio_test_large(folio))
20 		return false;
21 
22 	mapping = (struct address_space *)
23 		((unsigned long)folio->mapping & ~PAGE_MAPPING_FLAGS);
24 
25 	if (!mapping || mapping != folio->mapping)
26 		return false;
27 
28 	return mapping->a_ops == &secretmem_aops;
29 }
30 
31 bool vma_is_secretmem(struct vm_area_struct *vma);
32 bool secretmem_active(void);
33 
34 #else
35 
vma_is_secretmem(struct vm_area_struct * vma)36 static inline bool vma_is_secretmem(struct vm_area_struct *vma)
37 {
38 	return false;
39 }
40 
folio_is_secretmem(struct folio * folio)41 static inline bool folio_is_secretmem(struct folio *folio)
42 {
43 	return false;
44 }
45 
secretmem_active(void)46 static inline bool secretmem_active(void)
47 {
48 	return false;
49 }
50 
51 #endif /* CONFIG_SECRETMEM */
52 
53 #endif /* _LINUX_SECRETMEM_H */
54