firmware: dmi: Optimize dmi_matches
Function dmi_matches can me made a bit faster:
* The documented purpose of dmi_initialized is to catch too early
calls to dmi_check_system(). I'm not fully convinced it justifies
slowing down the initialization of all systems out there, but at
least the check should not have been moved from dmi_check_system()
to dmi_matches(). dmi_matches() is being called for every entry of
the table passed to dmi_check_system(), causing the same redundant
check to be performed again and again. So move it back to
dmi_check_system(), reverting this specific portion of commit
d7b1956fed33 ("DMI: Introduce dmi_first_match to make the interface
more flexible").
* Don't check for the exact_match flag again when we already know its
value.
Signed-off-by: Jean Delvare <jdelvare@suse.de>
Fixes: d7b1956fed33 ("DMI: Introduce dmi_first_match to make the interface more flexible")
Cc: Jani Nikula <jani.nikula@linux.intel.com>
Cc: Daniel Vetter <daniel.vetter@intel.com>
Cc: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Jeff Garzik <jgarzik@redhat.com>
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 7830419..84356d8 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -784,19 +784,20 @@ static bool dmi_matches(const struct dmi_system_id *dmi)
{
int i;
- WARN(!dmi_initialized, KERN_ERR "dmi check: not initialized yet.\n");
-
for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
int s = dmi->matches[i].slot;
if (s == DMI_NONE)
break;
if (dmi_ident[s]) {
- if (!dmi->matches[i].exact_match &&
- strstr(dmi_ident[s], dmi->matches[i].substr))
- continue;
- else if (dmi->matches[i].exact_match &&
- !strcmp(dmi_ident[s], dmi->matches[i].substr))
- continue;
+ if (dmi->matches[i].exact_match) {
+ if (!strcmp(dmi_ident[s],
+ dmi->matches[i].substr))
+ continue;
+ } else {
+ if (strstr(dmi_ident[s],
+ dmi->matches[i].substr))
+ continue;
+ }
}
/* No match */
@@ -832,6 +833,8 @@ int dmi_check_system(const struct dmi_system_id *list)
int count = 0;
const struct dmi_system_id *d;
+ WARN(!dmi_initialized, KERN_ERR "dmi check: not initialized yet.\n");
+
for (d = list; !dmi_is_end_of_table(d); d++)
if (dmi_matches(d)) {
count++;