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;