projects / deliverable / linux.git / blame
| Commit | Line | Data |
|---|---|---|
| 1da177e4 LT |
1 | /* |
| 2 | * An extensible bitmap is a bitmap that supports an | |
| 3 | * arbitrary number of bits. Extensible bitmaps are | |
| 4 | * used to represent sets of values, such as types, | |
| 5 | * roles, categories, and classes. | |
| 6 | * | |
| 7 | * Each extensible bitmap is implemented as a linked | |
| 8 | * list of bitmap nodes, where each bitmap node has | |
| 9 | * an explicitly specified starting bit position within | |
| 10 | * the total bitmap. | |
| 11 | * | |
| 12 | * Author : Stephen Smalley, <sds@epoch.ncsc.mil> | |
| 13 | */ | |
| 14 | #ifndef _SS_EBITMAP_H_ | |
| 15 | #define _SS_EBITMAP_H_ | |
| 16 | ||
| 17 | #define MAPTYPE u64 /* portion of bitmap in each node */ | |
| 18 | #define MAPSIZE (sizeof(MAPTYPE) * 8) /* number of bits in node bitmap */ | |
| 19 | #define MAPBIT 1ULL /* a bit in the node bitmap */ | |
| 20 | ||
| 21 | struct ebitmap_node { | |
| 22 | u32 startbit; /* starting position in the total bitmap */ | |
| 23 | MAPTYPE map; /* this node's portion of the bitmap */ | |
| 24 | struct ebitmap_node *next; | |
| 25 | }; | |
| 26 | ||
| 27 | struct ebitmap { | |
| 28 | struct ebitmap_node *node; /* first node in the bitmap */ | |
| 29 | u32 highbit; /* highest position in the total bitmap */ | |
| 30 | }; | |
| 31 | ||
| 32 | #define ebitmap_length(e) ((e)->highbit) | |
| 33 | #define ebitmap_startbit(e) ((e)->node ? (e)->node->startbit : 0) | |
| 34 | ||
| 782ebb99 SS |
35 | static inline unsigned int ebitmap_start(struct ebitmap *e, |
| 36 | struct ebitmap_node **n) | |
| 37 | { | |
| 38 | *n = e->node; | |
| 39 | return ebitmap_startbit(e); | |
| 40 | } | |
| 41 | ||
| 1da177e4 LT |
42 | static inline void ebitmap_init(struct ebitmap *e) |
| 43 | { | |
| 44 | memset(e, 0, sizeof(*e)); | |
| 45 | } | |
| 46 | ||
| 782ebb99 SS |
47 | static inline unsigned int ebitmap_next(struct ebitmap_node **n, |
| 48 | unsigned int bit) | |
| 49 | { | |
| 50 | if ((bit == ((*n)->startbit + MAPSIZE - 1)) && | |
| 51 | (*n)->next) { | |
| 52 | *n = (*n)->next; | |
| 53 | return (*n)->startbit; | |
| 54 | } | |
| 55 | ||
| 56 | return (bit+1); | |
| 57 | } | |
| 58 | ||
| 59 | static inline int ebitmap_node_get_bit(struct ebitmap_node * n, | |
| 60 | unsigned int bit) | |
| 61 | { | |
| 62 | if (n->map & (MAPBIT << (bit - n->startbit))) | |
| 63 | return 1; | |
| 64 | return 0; | |
| 65 | } | |
| 66 | ||
| 67 | #define ebitmap_for_each_bit(e, n, bit) \ | |
| 68 | for (bit = ebitmap_start(e, &n); bit < ebitmap_length(e); bit = ebitmap_next(&n, bit)) \ | |
| 69 | ||
| 1da177e4 LT |
70 | int ebitmap_cmp(struct ebitmap *e1, struct ebitmap *e2); |
| 71 | int ebitmap_cpy(struct ebitmap *dst, struct ebitmap *src); | |
| 72 | int ebitmap_contains(struct ebitmap *e1, struct ebitmap *e2); | |
| 73 | int ebitmap_get_bit(struct ebitmap *e, unsigned long bit); | |
| 74 | int ebitmap_set_bit(struct ebitmap *e, unsigned long bit, int value); | |
| 75 | void ebitmap_destroy(struct ebitmap *e); | |
| 76 | int ebitmap_read(struct ebitmap *e, void *fp); | |
| 77 | ||
| 78 | #endif /* _SS_EBITMAP_H_ */ |