From: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Date: Fri, 4 Dec 2009 18:24:19 +0000 (-0800)
Subject: DMI: allow omitting ident strings in DMI tables
X-Git-Tag: v2.6.33-rc6~2^2~62
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=75757507e014fa074d25d2883c4ab604999584bd;p=platform%2Fkernel%2Flinux-3.10.git

DMI: allow omitting ident strings in DMI tables

The purpose of dmi->ident is twofold - it may be used by DMI callback
functions when composing log messages; it is also used to determine
end of DMI table in dmi_check_system() and dmi_first_match(). However,
in case when callbacks are not interested in using ident at all it just
wastes memory. Let's make entries with empty first match slot serve as
end-of-table markers instead.

Acked-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
---

diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 938100f..3a2ccb0 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -429,7 +429,7 @@ static bool dmi_matches(const struct dmi_system_id *dmi)
 	for (i = 0; i < ARRAY_SIZE(dmi->matches); i++) {
 		int s = dmi->matches[i].slot;
 		if (s == DMI_NONE)
-			continue;
+			break;
 		if (dmi_ident[s]
 		    && strstr(dmi_ident[s], dmi->matches[i].substr))
 			continue;
@@ -440,6 +440,15 @@ static bool dmi_matches(const struct dmi_system_id *dmi)
 }
 
 /**
+ *	dmi_is_end_of_table - check for end-of-table marker
+ *	@dmi: pointer to the dmi_system_id structure to check
+ */
+static bool dmi_is_end_of_table(const struct dmi_system_id *dmi)
+{
+	return dmi->matches[0].slot == DMI_NONE;
+}
+
+/**
  *	dmi_check_system - check system DMI data
  *	@list: array of dmi_system_id structures to match against
  *		All non-null elements of the list must match
@@ -457,7 +466,7 @@ int dmi_check_system(const struct dmi_system_id *list)
 	int count = 0;
 	const struct dmi_system_id *d;
 
-	for (d = list; d->ident; d++)
+	for (d = list; !dmi_is_end_of_table(d); d++)
 		if (dmi_matches(d)) {
 			count++;
 			if (d->callback && d->callback(d))
@@ -484,7 +493,7 @@ const struct dmi_system_id *dmi_first_match(const struct dmi_system_id *list)
 {
 	const struct dmi_system_id *d;
 
-	for (d = list; d->ident; d++)
+	for (d = list; !dmi_is_end_of_table(d); d++)
 		if (dmi_matches(d))
 			return d;