[PATCH] x86_64: Clean up and tweak ACPI blacklist year code

 - Move the core parser into dmi_scan.c.  It can be useful for other
   subsystems too.
 - Differentiate between field doesn't exist and field is 0 or
   unparseable.  The first case is likely an old BIOS with broken ACPI,
   the later is likely a slightly buggy BIOS where someone forget to
   edit the date.  Don't blacklist in the later case.

Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 30 insertions, 0 deletions

diff --git a/arch/i386/kernel/dmi_scan.c b/arch/i386/kernel/dmi_scan.c
index ca2a0cbcac04..d2dfd9c8d691 100644
--- a/arch/i386/kernel/dmi_scan.c
+++ b/arch/i386/kernel/dmi_scan.c
@@ -299,3 +299,33 @@ struct dmi_device * dmi_find_device(int type, const char *name,
         return NULL;
 }
 EXPORT_SYMBOL(dmi_find_device);
+
+/**
+ *      dmi_get_year - Return year of a DMI date
+ *      @field: data index (like dmi_get_system_info)
+ *
+ *      Returns -1 when the field doesn't exist. 0 when it is broken.
+ */
+int dmi_get_year(int field)
+{
+        int year;
+        char *s = dmi_get_system_info(field);
+
+        if (!s)
+                return -1;
+        if (*s == '\0')
+                return 0;
+        s = strrchr(s, '/');
+        if (!s)
+                return 0;
+
+        s += 1;
+        year = simple_strtoul(s, NULL, 0);
+        if (year && year < 100) {       /* 2-digit year */
+                year += 1900;
+                if (year < 1996)        /* no dates < spec 1.0 */
+                        year += 100;
+        }
+
+        return year;
+}