38 lines · c
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 the7 * system's default huge page size. If a system supports multiple8 * huge page sizes, the desired huge page size can be specified in9 * bits [26:31] of the flag arguments. The value in these 6 bits10 * will encode the log2 of the huge page size.11 *12 * The following definitions are associated with this huge page size13 * encoding in flag arguments. System call specific header files14 * that use this encoding should include this file. They can then15 * provide definitions based on these with their own specific prefix.16 * for example:17 * #define MAP_HUGE_SHIFT HUGETLB_FLAG_ENCODE_SHIFT18 */19 20#define HUGETLB_FLAG_ENCODE_SHIFT 2621#define HUGETLB_FLAG_ENCODE_MASK 0x3f22 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