1#include <drivers/iommu/vt_d.h>
2#include <global.h>
3#include <math/align.h>
4#include <mem/alloc.h>
5
6#include "internal.h"
7
8static inline int bit_is_used(const uint8_t *bitmap, size_t bit_index) {
9 return (bitmap[bit_index / 8] >> (bit_index % 8)) & 1u;
10}
11
12static inline void bit_set_used(uint8_t *bitmap, size_t bit_index) {
13 bitmap[bit_index / 8] |= (uint8_t) (1u << (bit_index % 8));
14}
15
16static inline void bit_clear_used(uint8_t *bitmap, size_t bit_index) {
17 bitmap[bit_index / 8] &= (uint8_t) ~(1u << (bit_index % 8));
18}
19
20static ssize_t bitmap_alloc_first_free(uint8_t *bitmap, size_t total_bits) {
21 if (!bitmap)
22 return -1;
23
24 for (size_t i = 0; i < total_bits; ++i) {
25 if (!bit_is_used(bitmap, bit_index: i)) {
26 bit_set_used(bitmap, bit_index: i);
27 return (ssize_t) i;
28 }
29 }
30
31 return -1;
32}
33
34/* TODO: Move this out */
35static ssize_t bitmap_free(uint8_t *bitmap, size_t total_bits,
36 size_t bit_index) {
37 if (!bitmap)
38 return -1;
39
40 if (bit_index >= total_bits)
41 return -1;
42
43 bit_clear_used(bitmap, bit_index);
44 return 0;
45}
46
47ssize_t vtd_domain_alloc(struct vtd_unit *unit) {
48 enum irql irql = spin_lock(&unit->domain_bitmap_lock);
49
50 size_t ret =
51 bitmap_alloc_first_free(bitmap: unit->domain_bitmap, total_bits: unit->domain_count);
52
53 spin_unlock(&unit->domain_bitmap_lock, irql);
54
55 return ret;
56}
57
58ssize_t vtd_domain_free(struct vtd_unit *unit, size_t domain) {
59 enum irql irql = spin_lock(&unit->domain_bitmap_lock);
60
61 size_t ret = bitmap_free(bitmap: unit->domain_bitmap, total_bits: unit->domain_count, bit_index: domain);
62
63 spin_unlock(&unit->domain_bitmap_lock, irql);
64
65 return ret;
66}
67
68bool vtd_domain_init(struct vtd_unit *unit) {
69 spinlock_init(&unit->domain_bitmap_lock);
70 return (unit->domain_bitmap =
71 valloc(DIV_ROUND_UP(unit->domain_count, 8), ALLOC_ZERO));
72}
73