diff options
Diffstat (limited to 'drivers/firmware/efi/libstub/arm64.c')
| -rw-r--r-- | drivers/firmware/efi/libstub/arm64.c | 39 |
1 files changed, 31 insertions, 8 deletions
diff --git a/drivers/firmware/efi/libstub/arm64.c b/drivers/firmware/efi/libstub/arm64.c index 399770266372..8aad8c49d43f 100644 --- a/drivers/firmware/efi/libstub/arm64.c +++ b/drivers/firmware/efi/libstub/arm64.c @@ -16,20 +16,43 @@ static bool system_needs_vamap(void) { - const u8 *type1_family = efi_get_smbios_string(1, family); + const struct efi_smbios_type4_record *record; + const u32 __aligned(1) *socid; + const u8 *version; /* * Ampere eMAG, Altra, and Altra Max machines crash in SetTime() if - * SetVirtualAddressMap() has not been called prior. + * SetVirtualAddressMap() has not been called prior. Most Altra systems + * can be identified by the SMCCC soc ID, which is conveniently exposed + * via the type 4 SMBIOS records. Otherwise, test the processor version + * field. eMAG systems all appear to have the processor version field + * set to "eMAG". */ - if (!type1_family || ( - strcmp(type1_family, "eMAG") && - strcmp(type1_family, "Altra") && - strcmp(type1_family, "Altra Max"))) + record = (struct efi_smbios_type4_record *)efi_get_smbios_record(4); + if (!record) return false; - efi_warn("Working around broken SetVirtualAddressMap()\n"); - return true; + socid = (u32 *)record->processor_id; + switch (*socid & 0xffff000f) { + static char const altra[] = "Ampere(TM) Altra(TM) Processor"; + static char const emag[] = "eMAG"; + + default: + version = efi_get_smbios_string(&record->header, 4, + processor_version); + if (!version || (strncmp(version, altra, sizeof(altra) - 1) && + strncmp(version, emag, sizeof(emag) - 1))) + break; + + fallthrough; + + case 0x0a160001: // Altra + case 0x0a160002: // Altra Max + efi_warn("Working around broken SetVirtualAddressMap()\n"); + return true; + } + + return false; } efi_status_t check_platform_features(void) |