linux-headers (unknown)
1 #ifndef _ASM_GENERIC_HUGETLB_ENCODE_H_
2 #define _ASM_GENERIC_HUGETLB_ENCODE_H_
3
4 /*
5 * Several system calls take a flag to request "hugetlb" huge pages.
6 * Without further specification, these system calls will use the
7 * system's default huge page size. If a system supports multiple
8 * huge page sizes, the desired huge page size can be specified in
9 * bits [26:31] of the flag arguments. The value in these 6 bits
10 * will encode the log2 of the huge page size.
11 *
12 * The following definitions are associated with this huge page size
13 * encoding in flag arguments. System call specific header files
14 * that use this encoding should include this file. They can then
15 * provide definitions based on these with their own specific prefix.
16 * for example:
17 * #define MAP_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT
18 */
19
20 #define HUGETLB_FLAG_ENCODE_SHIFT 26
21 #define HUGETLB_FLAG_ENCODE_MASK 0x3f
22
23 #define HUGETLB_FLAG_ENCODE_16KB (14U << HUGETLB_FLAG_ENCODE_SHIFT)
24 #define HUGETLB_FLAG_ENCODE_64KB (16U << HUGETLB_FLAG_ENCODE_SHIFT)
25 #define HUGETLB_FLAG_ENCODE_512KB (19U << HUGETLB_FLAG_ENCODE_SHIFT)
26 #define HUGETLB_FLAG_ENCODE_1MB (20U << HUGETLB_FLAG_ENCODE_SHIFT)
27 #define HUGETLB_FLAG_ENCODE_2MB (21U << HUGETLB_FLAG_ENCODE_SHIFT)
28 #define HUGETLB_FLAG_ENCODE_8MB (23U << HUGETLB_FLAG_ENCODE_SHIFT)
29 #define HUGETLB_FLAG_ENCODE_16MB (24U << HUGETLB_FLAG_ENCODE_SHIFT)
30 #define HUGETLB_FLAG_ENCODE_32MB (25U << HUGETLB_FLAG_ENCODE_SHIFT)
31 #define HUGETLB_FLAG_ENCODE_256MB (28U << HUGETLB_FLAG_ENCODE_SHIFT)
32 #define HUGETLB_FLAG_ENCODE_512MB (29U << HUGETLB_FLAG_ENCODE_SHIFT)
33 #define HUGETLB_FLAG_ENCODE_1GB (30U << HUGETLB_FLAG_ENCODE_SHIFT)
34 #define HUGETLB_FLAG_ENCODE_2GB (31U << HUGETLB_FLAG_ENCODE_SHIFT)
35 #define HUGETLB_FLAG_ENCODE_16GB (34U << HUGETLB_FLAG_ENCODE_SHIFT)
36
37 #endif /* _ASM_GENERIC_HUGETLB_ENCODE_H_ */
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