efi: dmi: List SMBIOS3 table before SMBIOS table

The SMBIOS3 table should appear before the SMBIOS table in
/sys/firmware/efi/systab. This allows user-space utilities which
support both to pick the SMBIOS3 table with a single pass on systems
where both are implemented. The SMBIOS3 entry point is more capable
than the SMBIOS entry point so it should be preferred.

This follows the same logic as the ACPI20 table being listed before
the ACPI table.

Signed-off-by: Jean Delvare <jdelvare@suse.de>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Leif Lindholm <leif.lindholm@linaro.org>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 48b4c356740f15f76b10a3f8286b8edcfe11e579..ca617f40574ac2bb8e5697b858a1c52f93c8fad9 100644 (file)
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -86,10 +86,15 @@ static ssize_t systab_show(struct kobject *kobj,
                str += sprintf(str, "ACPI20=0x%lx\n", efi.acpi20);
        if (efi.acpi != EFI_INVALID_TABLE_ADDR)
                str += sprintf(str, "ACPI=0x%lx\n", efi.acpi);
-       if (efi.smbios != EFI_INVALID_TABLE_ADDR)
-               str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
+       /*
+        * If both SMBIOS and SMBIOS3 entry points are implemented, the
+        * SMBIOS3 entry point shall be preferred, so we list it first to
+        * let applications stop parsing after the first match.
+        */
        if (efi.smbios3 != EFI_INVALID_TABLE_ADDR)
                str += sprintf(str, "SMBIOS3=0x%lx\n", efi.smbios3);
+       if (efi.smbios != EFI_INVALID_TABLE_ADDR)
+               str += sprintf(str, "SMBIOS=0x%lx\n", efi.smbios);
        if (efi.hcdp != EFI_INVALID_TABLE_ADDR)
                str += sprintf(str, "HCDP=0x%lx\n", efi.hcdp);
        if (efi.boot_info != EFI_INVALID_TABLE_ADDR)