1#include <drivers/iommu/vt_d.h>
2#include <global.h>
3#include <math/div.h>
4#include <mem/alloc.h>
5
6static inline int bit_is_used(const uint8_t *bitmap, size_t bit_index) {
7 return (bitmap[bit_index / 8] >> (bit_index % 8)) & 1u;
8}
9
10static inline void bit_set_used(uint8_t *bitmap, size_t bit_index) {
11 bitmap[bit_index / 8] |= (uint8_t) (1u << (bit_index % 8));
12}
13
14static inline void bit_clear_used(uint8_t *bitmap, size_t bit_index) {
15 bitmap[bit_index / 8] &= (uint8_t) ~(1u << (bit_index % 8));
16}
17
18ssize_t bitmap_alloc_first_free(uint8_t *bitmap, size_t total_bits) {
19 if (!bitmap)
20 return -1;
21
22 for (size_t i = 0; i < total_bits; ++i) {
23 if (!bit_is_used(bitmap, bit_index: i)) {
24 bit_set_used(bitmap, bit_index: i);
25 return (ssize_t) i;
26 }
27 }
28
29 return -1;
30}
31
32/* TODO: Move this out */
33ssize_t bitmap_free(uint8_t *bitmap, size_t total_bits, size_t bit_index) {
34 if (!bitmap)
35 return -1;
36
37 if (bit_index >= total_bits)
38 return -1;
39
40 bit_clear_used(bitmap, bit_index);
41 return 0;
42}
43
44ssize_t vtd_domain_alloc(struct vtd_unit *unit) {
45 enum irql irql = spin_lock(&unit->domain_bitmap_lock);
46
47 size_t ret =
48 bitmap_alloc_first_free(bitmap: unit->domain_bitmap, total_bits: unit->domain_count);
49
50 spin_unlock(&unit->domain_bitmap_lock, irql);
51
52 return ret;
53}
54
55ssize_t vtd_domain_free(struct vtd_unit *unit, size_t domain) {
56 enum irql irql = spin_lock(&unit->domain_bitmap_lock);
57
58 size_t ret = bitmap_free(bitmap: unit->domain_bitmap, total_bits: unit->domain_count, bit_index: domain);
59
60 spin_unlock(&unit->domain_bitmap_lock, irql);
61
62 return ret;
63}
64
65bool vtd_domain_init(struct vtd_unit *unit) {
66 spinlock_init(&unit->domain_bitmap_lock);
67 return (unit->domain_bitmap =
68 kmalloc(DIV_ROUND_UP(unit->domain_count, 8), ALLOC_FLAGS_ZERO));
69}
70