dmi_scan: refactor dmi_scan_machine(), {smbios,dmi}_present()
Move the calls to memcpy_fromio() up into the loop in
dmi_scan_machine(), and move the signature checks back down into
dmi_decode(). We need to check at 16-byte intervals but keep a 32-byte
buffer for an SMBIOS entry, so shift the buffer after each iteration.
Merge smbios_present() into dmi_present(), so we look for an SMBIOS
signature at the beginning of the given buffer and then for a DMI
signature at an offset of 16 bytes.
[artem.savkov@gmail.com: use proper buf type in dmi_present()]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Reported-by: Tim McGrath <tmhikaru@gmail.com>
Tested-by: Tim Mcgrath <tmhikaru@gmail.com>
Cc: Zhenzhong Duan <zhenzhong.duan@oracle.com>
Signed-off-by: Artem Savkov <artem.savkov@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 98c62081..b95159b 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -419,22 +419,45 @@
dmi_get_system_info(DMI_BIOS_DATE));
}
-static int __init dmi_present(const char __iomem *p)
+static int __init dmi_present(const u8 *buf)
{
- u8 buf[15];
+ int smbios_ver;
- memcpy_fromio(buf, p, 15);
- if (dmi_checksum(buf, 15)) {
+ if (memcmp(buf, "_SM_", 4) == 0 &&
+ buf[5] < 32 && dmi_checksum(buf, buf[5])) {
+ smbios_ver = (buf[6] << 8) + buf[7];
+
+ /* Some BIOS report weird SMBIOS version, fix that up */
+ switch (smbios_ver) {
+ case 0x021F:
+ case 0x0221:
+ pr_debug("SMBIOS version fixup(2.%d->2.%d)\n",
+ smbios_ver & 0xFF, 3);
+ smbios_ver = 0x0203;
+ break;
+ case 0x0233:
+ pr_debug("SMBIOS version fixup(2.%d->2.%d)\n", 51, 6);
+ smbios_ver = 0x0206;
+ break;
+ }
+ } else {
+ smbios_ver = 0;
+ }
+
+ buf += 16;
+
+ if (memcmp(buf, "_DMI_", 5) == 0 && 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];
if (dmi_walk_early(dmi_decode) == 0) {
- if (dmi_ver)
+ if (smbios_ver) {
+ dmi_ver = smbios_ver;
pr_info("SMBIOS %d.%d present.\n",
dmi_ver >> 8, dmi_ver & 0xFF);
- else {
+ } else {
dmi_ver = (buf[14] & 0xF0) << 4 |
(buf[14] & 0x0F);
pr_info("Legacy DMI %d.%d present.\n",
@@ -445,40 +468,14 @@
return 0;
}
}
- dmi_ver = 0;
- return 1;
-}
-static int __init smbios_present(const char __iomem *p)
-{
- u8 buf[32];
-
- 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;
- }
- return memcmp(p + 16, "_DMI_", 5) || dmi_present(p + 16);
- }
return 1;
}
void __init dmi_scan_machine(void)
{
char __iomem *p, *q;
- int rc;
+ char buf[32];
if (efi_enabled(EFI_CONFIG_TABLES)) {
if (efi.smbios == EFI_INVALID_TABLE_ADDR)
@@ -491,10 +488,10 @@
p = dmi_ioremap(efi.smbios, 32);
if (p == NULL)
goto error;
-
- rc = smbios_present(p);
+ memcpy_fromio(buf, p, 32);
dmi_iounmap(p, 32);
- if (!rc) {
+
+ if (!dmi_present(buf)) {
dmi_available = 1;
goto out;
}
@@ -509,18 +506,15 @@
if (p == NULL)
goto error;
+ memset(buf, 0, 16);
for (q = p; q < p + 0x10000; q += 16) {
- 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) {
+ memcpy_fromio(buf + 16, q, 16);
+ if (!dmi_present(buf)) {
dmi_available = 1;
dmi_iounmap(p, 0x10000);
goto out;
}
+ memcpy(buf, buf + 16, 16);
}
dmi_iounmap(p, 0x10000);
}
