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
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