name : hugetlb_encode.h #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_16KB (14 << HUGETLB_FLAG_ENCODE_SHIFT) #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_32MB (25 << HUGETLB_FLAG_ENCODE_SHIFT) #define HUGETLB_FLAG_ENCODE_256MB (28 << HUGETLB_FLAG_ENCODE_SHIFT) #define HUGETLB_FLAG_ENCODE_512MB (29 << 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_ */