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path: root/drivers/firmware/dmi_scan.c
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Diffstat (limited to 'drivers/firmware/dmi_scan.c')
-rw-r--r--drivers/firmware/dmi_scan.c79
1 files changed, 72 insertions, 7 deletions
diff --git a/drivers/firmware/dmi_scan.c b/drivers/firmware/dmi_scan.c
index 17afc51f3054..c5f7b4e9eb6c 100644
--- a/drivers/firmware/dmi_scan.c
+++ b/drivers/firmware/dmi_scan.c
@@ -93,6 +93,12 @@ static void dmi_table(u8 *buf, int len, int num,
const struct dmi_header *dm = (const struct dmi_header *)data;
/*
+ * 7.45 End-of-Table (Type 127) [SMBIOS reference spec v3.0.0]
+ */
+ if (dm->type == DMI_ENTRY_END_OF_TABLE)
+ break;
+
+ /*
* We want to know the total length (formatted area and
* strings) before decoding to make sure we won't run off the
* table in dmi_decode or dmi_string
@@ -107,7 +113,7 @@ static void dmi_table(u8 *buf, int len, int num,
}
}
-static u32 dmi_base;
+static phys_addr_t dmi_base;
static u16 dmi_len;
static u16 dmi_num;
@@ -467,7 +473,7 @@ static int __init dmi_present(const u8 *buf)
if (memcmp(buf, "_SM_", 4) == 0 &&
buf[5] < 32 && dmi_checksum(buf, buf[5])) {
- smbios_ver = (buf[6] << 8) + buf[7];
+ smbios_ver = get_unaligned_be16(buf + 6);
/* Some BIOS report weird SMBIOS version, fix that up */
switch (smbios_ver) {
@@ -489,10 +495,9 @@ static int __init dmi_present(const u8 *buf)
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];
+ dmi_num = get_unaligned_le16(buf + 12);
+ dmi_len = get_unaligned_le16(buf + 6);
+ dmi_base = get_unaligned_le32(buf + 8);
if (dmi_walk_early(dmi_decode) == 0) {
if (smbios_ver) {
@@ -514,12 +519,72 @@ static int __init dmi_present(const u8 *buf)
return 1;
}
+/*
+ * Check for the SMBIOS 3.0 64-bit entry point signature. Unlike the legacy
+ * 32-bit entry point, there is no embedded DMI header (_DMI_) in here.
+ */
+static int __init dmi_smbios3_present(const u8 *buf)
+{
+ if (memcmp(buf, "_SM3_", 5) == 0 &&
+ buf[6] < 32 && dmi_checksum(buf, buf[6])) {
+ dmi_ver = get_unaligned_be16(buf + 7);
+ dmi_len = get_unaligned_le32(buf + 12);
+ dmi_base = get_unaligned_le64(buf + 16);
+
+ /*
+ * The 64-bit SMBIOS 3.0 entry point no longer has a field
+ * containing the number of structures present in the table.
+ * Instead, it defines the table size as a maximum size, and
+ * relies on the end-of-table structure type (#127) to be used
+ * to signal the end of the table.
+ * So let's define dmi_num as an upper bound as well: each
+ * structure has a 4 byte header, so dmi_len / 4 is an upper
+ * bound for the number of structures in the table.
+ */
+ dmi_num = dmi_len / 4;
+
+ if (dmi_walk_early(dmi_decode) == 0) {
+ pr_info("SMBIOS %d.%d present.\n",
+ dmi_ver >> 8, dmi_ver & 0xFF);
+ dmi_format_ids(dmi_ids_string, sizeof(dmi_ids_string));
+ pr_debug("DMI: %s\n", dmi_ids_string);
+ return 0;
+ }
+ }
+ return 1;
+}
+
void __init dmi_scan_machine(void)
{
char __iomem *p, *q;
char buf[32];
if (efi_enabled(EFI_CONFIG_TABLES)) {
+ /*
+ * According to the DMTF SMBIOS reference spec v3.0.0, it is
+ * allowed to define both the 64-bit entry point (smbios3) and
+ * the 32-bit entry point (smbios), in which case they should
+ * either both point to the same SMBIOS structure table, or the
+ * table pointed to by the 64-bit entry point should contain a
+ * superset of the table contents pointed to by the 32-bit entry
+ * point (section 5.2)
+ * This implies that the 64-bit entry point should have
+ * precedence if it is defined and supported by the OS. If we
+ * have the 64-bit entry point, but fail to decode it, fall
+ * back to the legacy one (if available)
+ */
+ if (efi.smbios3 != EFI_INVALID_TABLE_ADDR) {
+ p = dmi_early_remap(efi.smbios3, 32);
+ if (p == NULL)
+ goto error;
+ memcpy_fromio(buf, p, 32);
+ dmi_early_unmap(p, 32);
+
+ if (!dmi_smbios3_present(buf)) {
+ dmi_available = 1;
+ goto out;
+ }
+ }
if (efi.smbios == EFI_INVALID_TABLE_ADDR)
goto error;
@@ -552,7 +617,7 @@ void __init dmi_scan_machine(void)
memset(buf, 0, 16);
for (q = p; q < p + 0x10000; q += 16) {
memcpy_fromio(buf + 16, q, 16);
- if (!dmi_present(buf)) {
+ if (!dmi_smbios3_present(buf) || !dmi_present(buf)) {
dmi_available = 1;
dmi_early_unmap(p, 0x10000);
goto out;