| Konrad Rzeszutek Wilk | 5bef80a | 2010-08-26 13:57:58 -0400 | [diff] [blame] | 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 |