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_ */ |
38 | |