Ingo Molnar | 549a397 | 2017-09-13 09:38:23 +0200 | [diff] [blame] | 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_64KB (16 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 24 | #define HUGETLB_FLAG_ENCODE_512KB (19 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 25 | #define HUGETLB_FLAG_ENCODE_1MB (20 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 26 | #define HUGETLB_FLAG_ENCODE_2MB (21 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 27 | #define HUGETLB_FLAG_ENCODE_8MB (23 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 28 | #define HUGETLB_FLAG_ENCODE_16MB (24 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 29 | #define HUGETLB_FLAG_ENCODE_256MB (28 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 30 | #define HUGETLB_FLAG_ENCODE_1GB (30 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 31 | #define HUGETLB_FLAG_ENCODE_2GB (31 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 32 | #define HUGETLB_FLAG_ENCODE_16GB (34 << HUGETLB_FLAG_ENCODE_SHIFT) |
| 33 | |
| 34 | #endif /* _ASM_GENERIC_HUGETLB_ENCODE_H_ */ |