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authorZhenzhong Duan <zhenzhong.duan@oracle.com>2012-12-20 15:05:14 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-01-27 20:47:44 -0800
commitb88532f7efaff806193edbbe826ef0d0f8ac1063 (patch)
tree64bea366565cc41c88e6542d1b18501af38cb60e
parent220a0bc2df2b7385d278864fa1f8b47f9c78c8a2 (diff)
downloadlinux-linaro-stable-b88532f7efaff806193edbbe826ef0d0f8ac1063.tar.gz
drivers/firmware/dmi_scan.c: fetch dmi version from SMBIOS if it exists
commit 9f9c9cbb60576a1518d0bf93fb8e499cffccf377 upstream. The right dmi version is in SMBIOS if it's zero in DMI region This issue was originally found from an oracle bug. One customer noticed system UUID doesn't match between dmidecode & uek2. - HP ProLiant BL460c G6 : # cat /sys/devices/virtual/dmi/id/product_uuid 00000000-0000-4C48-3031-4D5030333531 # dmidecode | grep -i uuid UUID: 00000000-0000-484C-3031-4D5030333531 From SMBIOS 2.6 on, spec use little-endian encoding for UUID other than network byte order. So we need to get dmi version to distinguish. If version is 0.0, the real version is taken from the SMBIOS version. This is part of original kernel comment in code. [akpm@linux-foundation.org: checkpatch fixes] Signed-off-by: Zhenzhong Duan <zhenzhong.duan@oracle.com> Cc: Feng Jin <joe.jin@oracle.com> Cc: Jean Delvare <khali@linux-fr.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Abdallah Chatila <abdallah.chatila@ericsson.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/firmware/dmi_scan.c62
1 files changed, 47 insertions, 15 deletions
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 3714e3c..fd3ae62 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -119,12 +119,12 @@ static int __init dmi_walk_early(void (*decode)(const struct dmi_header *,
return 0;
}
-static int __init dmi_checksum(const u8 *buf)
+static int __init dmi_checksum(const u8 *buf, u8 len)
{
u8 sum = 0;
int a;
- for (a = 0; a < 15; a++)
+ for (a = 0; a < len; a++)
sum += buf[a];
return sum == 0;
@@ -415,30 +415,57 @@ static int __init dmi_present(const char __iomem *p)
u8 buf[15];
memcpy_fromio(buf, p, 15);
- if ((memcmp(buf, "_DMI_", 5) == 0) && dmi_checksum(buf)) {
+ if (dmi_checksum(buf, 15)) {
dmi_num = (buf[13] << 8) | buf[12];
dmi_len = (buf[7] << 8) | buf[6];
dmi_base = (buf[11] << 24) | (buf[10] << 16) |
(buf[9] << 8) | buf[8];
- /*
- * DMI version 0.0 means that the real version is taken from
- * the SMBIOS version, which we don't know at this point.
- */
- dmi_ver = (buf[14] & 0xf0) << 4 | (buf[14] & 0x0f);
- if (buf[14] != 0)
- printk(KERN_INFO "DMI %d.%d present.\n",
- buf[14] >> 4, buf[14] & 0xF);
- else
- printk(KERN_INFO "DMI present.\n");
if (dmi_walk_early(dmi_decode) == 0) {
+ if (dmi_ver)
+ pr_info("SMBIOS %d.%d present.\n",
+ dmi_ver >> 8, dmi_ver & 0xFF);
+ else {
+ dmi_ver = (buf[14] & 0xF0) << 4 |
+ (buf[14] & 0x0F);
+ pr_info("Legacy DMI %d.%d present.\n",
+ dmi_ver >> 8, dmi_ver & 0xFF);
+ }
dmi_dump_ids();
return 0;
}
}
+ dmi_ver = 0;
return 1;
}
+static int __init smbios_present(const char __iomem *p)
+{
+ u8 buf[32];
+ int offset = 0;
+
+ memcpy_fromio(buf, p, 32);
+ if ((buf[5] < 32) && dmi_checksum(buf, buf[5])) {
+ dmi_ver = (buf[6] << 8) + buf[7];
+
+ /* Some BIOS report weird SMBIOS version, fix that up */
+ switch (dmi_ver) {
+ case 0x021F:
+ case 0x0221:
+ pr_debug("SMBIOS version fixup(2.%d->2.%d)\n",
+ dmi_ver & 0xFF, 3);
+ dmi_ver = 0x0203;
+ break;
+ case 0x0233:
+ pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", 51, 6);
+ dmi_ver = 0x0206;
+ break;
+ }
+ offset = 16;
+ }
+ return dmi_present(buf + offset);
+}
+
void __init dmi_scan_machine(void)
{
char __iomem *p, *q;
@@ -456,7 +483,7 @@ void __init dmi_scan_machine(void)
if (p == NULL)
goto error;
- rc = dmi_present(p + 0x10); /* offset of _DMI_ string */
+ rc = smbios_present(p);
dmi_iounmap(p, 32);
if (!rc) {
dmi_available = 1;
@@ -474,7 +501,12 @@ void __init dmi_scan_machine(void)
goto error;
for (q = p; q < p + 0x10000; q += 16) {
- rc = dmi_present(q);
+ if (memcmp(q, "_SM_", 4) == 0 && q - p <= 0xFFE0)
+ rc = smbios_present(q);
+ else if (memcmp(q, "_DMI_", 5) == 0)
+ rc = dmi_present(q);
+ else
+ continue;
if (!rc) {
dmi_available = 1;
dmi_iounmap(p, 0x10000);