diff options
Diffstat (limited to 'arch/x86_64/kernel/e820.c')
| -rw-r--r-- | arch/x86_64/kernel/e820.c | 29 |
1 files changed, 29 insertions, 0 deletions
diff --git a/arch/x86_64/kernel/e820.c b/arch/x86_64/kernel/e820.c index 764bf23c710..d6d7f731f6f 100644 --- a/arch/x86_64/kernel/e820.c +++ b/arch/x86_64/kernel/e820.c @@ -108,6 +108,35 @@ e820_any_mapped(unsigned long start, unsigned long end, unsigned type) return 0; } +/* + * This function checks if the entire range <start,end> is mapped with type. + * + * Note: this function only works correct if the e820 table is sorted and + * not-overlapping, which is the case + */ +int __init e820_all_mapped(unsigned long start, unsigned long end, unsigned type) +{ + int i; + for (i = 0; i < e820.nr_map; i++) { + struct e820entry *ei = &e820.map[i]; + if (type && ei->type != type) + continue; + /* is the region (part) in overlap with the current region ?*/ + if (ei->addr >= end || ei->addr + ei->size <= start) + continue; + + /* if the region is at the beginning of <start,end> we move + * start to the end of the region since it's ok until there + */ + if (ei->addr <= start) + start = ei->addr + ei->size; + /* if start is now at or beyond end, we're done, full coverage */ + if (start >= end) + return 1; /* we're done */ + } + return 0; +} + /* * Find a free area in a specific range. */ |