firewire: optimize fw_core_add_address_handler

Potentially avoids unnecessary loop runs.
Guarantee quadlet-aligned starts of address regions.
Document the return values.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
This commit is contained in:
Stefan Richter 2007-07-17 02:10:16 +02:00
parent 002a98f147
commit 1415d9189e
1 changed files with 9 additions and 3 deletions

View File

@ -410,7 +410,12 @@ EXPORT_SYMBOL(fw_unit_space_region);
* controller. When a request is received that falls within the
* specified address range, the specified callback is invoked. The
* parameters passed to the callback give the details of the
* particular request
* particular request.
*
* Return value: 0 on success, non-zero otherwise.
* The start offset of the handler's address region is determined by
* fw_core_add_address_handler() and is returned in handler->offset.
* The offset is quadlet-aligned.
*/
int
fw_core_add_address_handler(struct fw_address_handler *handler,
@ -422,14 +427,15 @@ fw_core_add_address_handler(struct fw_address_handler *handler,
spin_lock_irqsave(&address_handler_lock, flags);
handler->offset = region->start;
handler->offset = roundup(region->start, 4);
while (handler->offset + handler->length <= region->end) {
other =
lookup_overlapping_address_handler(&address_handler_list,
handler->offset,
handler->length);
if (other != NULL) {
handler->offset += other->length;
handler->offset =
roundup(other->offset + other->length, 4);
} else {
list_add_tail(&handler->link, &address_handler_list);
ret = 0;