1 #include <linux/dma-mapping.h>
2 #include <asm/iommu_table.h>
3 #include <linux/string.h>
4 #include <linux/kallsyms.h>
5
6
7 #define DEBUG 1
8
9 static struct iommu_table_entry * __init
find_dependents_of(struct iommu_table_entry * start,struct iommu_table_entry * finish,struct iommu_table_entry * q)10 find_dependents_of(struct iommu_table_entry *start,
11 struct iommu_table_entry *finish,
12 struct iommu_table_entry *q)
13 {
14 struct iommu_table_entry *p;
15
16 if (!q)
17 return NULL;
18
19 for (p = start; p < finish; p++)
20 if (p->detect == q->depend)
21 return p;
22
23 return NULL;
24 }
25
26
sort_iommu_table(struct iommu_table_entry * start,struct iommu_table_entry * finish)27 void __init sort_iommu_table(struct iommu_table_entry *start,
28 struct iommu_table_entry *finish) {
29
30 struct iommu_table_entry *p, *q, tmp;
31
32 for (p = start; p < finish; p++) {
33 again:
34 q = find_dependents_of(start, finish, p);
35 /* We are bit sneaky here. We use the memory address to figure
36 * out if the node we depend on is past our point, if so, swap.
37 */
38 if (q > p) {
39 tmp = *p;
40 memmove(p, q, sizeof(*p));
41 *q = tmp;
42 goto again;
43 }
44 }
45
46 }
47
48 #ifdef DEBUG
check_iommu_entries(struct iommu_table_entry * start,struct iommu_table_entry * finish)49 void __init check_iommu_entries(struct iommu_table_entry *start,
50 struct iommu_table_entry *finish)
51 {
52 struct iommu_table_entry *p, *q, *x;
53
54 /* Simple cyclic dependency checker. */
55 for (p = start; p < finish; p++) {
56 q = find_dependents_of(start, finish, p);
57 x = find_dependents_of(start, finish, q);
58 if (p == x) {
59 printk(KERN_ERR "CYCLIC DEPENDENCY FOUND! %pS depends on %pS and vice-versa. BREAKING IT.\n",
60 p->detect, q->detect);
61 /* Heavy handed way..*/
62 x->depend = 0;
63 }
64 }
65
66 for (p = start; p < finish; p++) {
67 q = find_dependents_of(p, finish, p);
68 if (q && q > p) {
69 printk(KERN_ERR "EXECUTION ORDER INVALID! %pS should be called before %pS!\n",
70 p->detect, q->detect);
71 }
72 }
73 }
74 #else
check_iommu_entries(struct iommu_table_entry * start,struct iommu_table_entry * finish)75 inline void check_iommu_entries(struct iommu_table_entry *start,
76 struct iommu_table_entry *finish)
77 {
78 }
79 #endif
80