diff options
Diffstat (limited to 'arch/x86/kernel/pci-iommu_table.c')
-rw-r--r-- | arch/x86/kernel/pci-iommu_table.c | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/arch/x86/kernel/pci-iommu_table.c b/arch/x86/kernel/pci-iommu_table.c new file mode 100644 index 000000000000..35ccf75696eb --- /dev/null +++ b/arch/x86/kernel/pci-iommu_table.c | |||
@@ -0,0 +1,79 @@ | |||
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 | |||
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 | ||
75 | inline void check_iommu_entries(struct iommu_table_entry *start, | ||
76 | struct iommu_table_entry *finish) | ||
77 | { | ||
78 | } | ||
79 | #endif | ||