[PATCH] x86_64: Introduce e820_all_mapped

Introduce a e820_all_mapped() function which checks if the entire range
<start,end> is mapped with type.

This is done by moving the local start variable to the end of each
known-good region; if at the end of the function the start address is
still before end, there must be a part that's not of the correct type;
otherwise it's a good region.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Arjan van de Ven
2006-04-07 19:49:27 +02:00
committed by Linus Torvalds
parent eee5a9fa63
commit 952223683e
4 changed files with 68 additions and 0 deletions

View File

@@ -963,6 +963,36 @@ efi_memory_present_wrapper(unsigned long start, unsigned long end, void *arg)
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 the highest page frame number we have available
*/