| #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_64KB (16 << HUGETLB_FLAG_ENCODE_SHIFT) |
| #define HUGETLB_FLAG_ENCODE_512KB (19 << HUGETLB_FLAG_ENCODE_SHIFT) |
| #define HUGETLB_FLAG_ENCODE_1MB (20 << HUGETLB_FLAG_ENCODE_SHIFT) |
| #define HUGETLB_FLAG_ENCODE_2MB (21 << HUGETLB_FLAG_ENCODE_SHIFT) |
| #define HUGETLB_FLAG_ENCODE_8MB (23 << HUGETLB_FLAG_ENCODE_SHIFT) |
| #define HUGETLB_FLAG_ENCODE_16MB (24 << HUGETLB_FLAG_ENCODE_SHIFT) |
| #define HUGETLB_FLAG_ENCODE_256MB (28 << HUGETLB_FLAG_ENCODE_SHIFT) |
| #define HUGETLB_FLAG_ENCODE_1GB (30 << HUGETLB_FLAG_ENCODE_SHIFT) |
| #define HUGETLB_FLAG_ENCODE_2GB (31 << HUGETLB_FLAG_ENCODE_SHIFT) |
| #define HUGETLB_FLAG_ENCODE_16GB (34 << HUGETLB_FLAG_ENCODE_SHIFT) |
| |
| #endif /* _ASM_GENERIC_HUGETLB_ENCODE_H_ */ |
