summaryrefslogtreecommitdiff
path: root/include/arch/x86_64/asm-generic/hugetlb_encode.h
blob: 8ad187b5df1e25c4bd74da75b519000f29b31f1f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
#ifndef _ASM_GENERIC_HUGETLB_ENCODE_H_
#define _ASM_GENERIC_HUGETLB_ENCODE_H_

/*
 * Several system calls take a flag to request "hugetlb" huge pages.
 * Without further specification, these system calls will use the
 * system's default huge page size.  If a system supports multiple
 * huge page sizes, the desired huge page size can be specified in
 * bits [26:31] of the flag arguments.  The value in these 6 bits
 * will encode the log2 of the huge page size.
 *
 * The following definitions are associated with this huge page size
 * encoding in flag arguments.  System call specific header files
 * that use this encoding should include this file.  They can then
 * provide definitions based on these with their own specific prefix.
 * for example:
 * #define MAP_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT
 */

#define HUGETLB_FLAG_ENCODE_SHIFT 26
#define HUGETLB_FLAG_ENCODE_MASK  0x3f

#define HUGETLB_FLAG_ENCODE_16KB  (14U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_64KB  (16U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_512KB (19U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_1MB	  (20U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_2MB	  (21U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_8MB	  (23U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_16MB  (24U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_32MB  (25U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_256MB (28U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_512MB (29U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_1GB	  (30U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_2GB	  (31U << HUGETLB_FLAG_ENCODE_SHIFT)
#define HUGETLB_FLAG_ENCODE_16GB  (34U << HUGETLB_FLAG_ENCODE_SHIFT)

#endif /* _ASM_GENERIC_HUGETLB_ENCODE_H_ */