Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael...
[linux-2.6.git] / arch / x86 / kernel / pci-iommu_table.c
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
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
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
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         char sym_p[KSYM_SYMBOL_LEN];
54         char sym_q[KSYM_SYMBOL_LEN];
55
56         /* Simple cyclic dependency checker. */
57         for (p = start; p < finish; p++) {
58                 q = find_dependents_of(start, finish, p);
59                 x = find_dependents_of(start, finish, q);
60                 if (p == x) {
61                         sprint_symbol(sym_p, (unsigned long)p->detect);
62                         sprint_symbol(sym_q, (unsigned long)q->detect);
63
64                         printk(KERN_ERR "CYCLIC DEPENDENCY FOUND! %s depends" \
65                                         " on %s and vice-versa. BREAKING IT.\n",
66                                         sym_p, sym_q);
67                         /* Heavy handed way..*/
68                         x->depend = 0;
69                 }
70         }
71
72         for (p = start; p < finish; p++) {
73                 q = find_dependents_of(p, finish, p);
74                 if (q && q > p) {
75                         sprint_symbol(sym_p, (unsigned long)p->detect);
76                         sprint_symbol(sym_q, (unsigned long)q->detect);
77
78                         printk(KERN_ERR "EXECUTION ORDER INVALID! %s "\
79                                         "should be called before %s!\n",
80                                         sym_p, sym_q);
81                 }
82         }
83 }
84 #else
85 inline void check_iommu_entries(struct iommu_table_entry *start,
86                                        struct iommu_table_entry *finish)
87 {
88 }
89 #endif