From: Bob Moore Date: Thu, 19 Mar 2009 02:12:13 +0000 (+0800) Subject: ACPICA: FADT: Favor 32-bit register addresses for compatibility X-Git-Url: http://pilppa.com/gitweb/?a=commitdiff_plain;h=31fbc073a35a017e34840deb9e865a701e986002;p=linux-2.6-omap-h63xx.git ACPICA: FADT: Favor 32-bit register addresses for compatibility Use the 32-bit register addresses whenever they are non-zero. This means that the 32-bit addresses are favored over the 64-bit (GAS) addresses. The 64-bit addresses are only used if the 32-bit addresses are zero. This change provides compatibility with all versions of Windows. The worst case that this solves is when both the 32-bit and 64-bit addresses are non-zero, but only the 32-bit addresses are actually valid. This appears to happen in some BIOSes because in this case, Windows uses the 32-bit addresses. Signed-off-by: Bob Moore Signed-off-by: Lin Ming Signed-off-by: Len Brown --- diff --git a/drivers/acpi/acpica/tbfadt.c b/drivers/acpi/acpica/tbfadt.c index ff89cfee0e7..f87bfb259ef 100644 --- a/drivers/acpi/acpica/tbfadt.c +++ b/drivers/acpi/acpica/tbfadt.c @@ -320,29 +320,35 @@ void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length) * RETURN: None * * DESCRIPTION: Converts all versions of the FADT to a common internal format. - * Expand all 32-bit addresses to 64-bit. + * Expand 32-bit addresses to 64-bit as necessary. * * NOTE: acpi_gbl_FADT must be of size (struct acpi_table_fadt), * and must contain a copy of the actual FADT. * - * ACPICA will use the "X" fields of the FADT for all addresses. + * Notes on 64-bit register addresses: * - * "X" fields are optional extensions to the original V1.0 fields. Even if - * they are present in the structure, they can be optionally not used by - * setting them to zero. Therefore, we must selectively expand V1.0 fields - * if the corresponding X field is zero. + * After this FADT conversion, later ACPICA code will only use the 64-bit "X" + * fields of the FADT for all ACPI register addresses. * - * For ACPI 1.0 FADTs, all address fields are expanded to the corresponding - * "X" fields. + * The 64-bit "X" fields are optional extensions to the original 32-bit FADT + * V1.0 fields. Even if they are present in the FADT, they are optional and + * are unused if the BIOS sets them to zero. Therefore, we must copy/expand + * 32-bit V1.0 fields if the corresponding X field is zero. * - * For ACPI 2.0 FADTs, any "X" fields that are NULL are filled in by - * expanding the corresponding ACPI 1.0 field. + * For ACPI 1.0 FADTs, all 32-bit address fields are expanded to the + * corresponding "X" fields in the internal FADT. + * + * For ACPI 2.0+ FADTs, all valid (non-zero) 32-bit address fields are expanded + * to the corresponding 64-bit X fields. For compatibility with other ACPI + * implementations, we ignore the 64-bit field if the 32-bit field is valid, + * regardless of whether the host OS is 32-bit or 64-bit. * ******************************************************************************/ static void acpi_tb_convert_fadt(void) { - struct acpi_generic_address *target64; + struct acpi_generic_address *address64; + u32 address32; u32 i; /* Update the local FADT table header length */ @@ -391,29 +397,51 @@ static void acpi_tb_convert_fadt(void) * Expand the ACPI 1.0 32-bit addresses to the ACPI 2.0 64-bit "X" * generic address structures as necessary. Later code will always use * the 64-bit address structures. + * + * March 2009: + * We now always use the 32-bit address if it is valid (non-null). This + * is not in accordance with the ACPI specification which states that + * the 64-bit address supersedes the 32-bit version, but we do this for + * compatibility with other ACPI implementations. Most notably, in the + * case where both the 32 and 64 versions are non-null, we use the 32-bit + * version. This is the only address that is guaranteed to have been + * tested by the BIOS manufacturer. */ for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) { - target64 = - ACPI_ADD_PTR(struct acpi_generic_address, &acpi_gbl_FADT, - fadt_info_table[i].address64); + address32 = *ACPI_ADD_PTR(u32, + &acpi_gbl_FADT, + fadt_info_table[i].address32); - /* Expand only if the 64-bit X target is null */ + address64 = ACPI_ADD_PTR(struct acpi_generic_address, + &acpi_gbl_FADT, + fadt_info_table[i].address64); - if (!target64->address) { + /* + * If both 32- and 64-bit addresses are valid (non-zero), + * they must match. + */ + if (address64->address && address32 && + (address64->address != (u64) address32)) { + ACPI_ERROR((AE_INFO, + "32/64X address mismatch in %s: %8.8X/%8.8X%8.8X, using 32", + fadt_info_table[i].name, address32, + ACPI_FORMAT_UINT64(address64->address))); + } - /* The space_id is always I/O for the 32-bit legacy address fields */ + /* Always use 32-bit address if it is valid (non-null) */ - acpi_tb_init_generic_address(target64, + if (address32) { + /* + * Copy the 32-bit address to the 64-bit GAS structure. The + * Space ID is always I/O for 32-bit legacy address fields + */ + acpi_tb_init_generic_address(address64, ACPI_ADR_SPACE_SYSTEM_IO, *ACPI_ADD_PTR(u8, &acpi_gbl_FADT, fadt_info_table [i].length), - (u64) * ACPI_ADD_PTR(u32, - &acpi_gbl_FADT, - fadt_info_table - [i]. - address32)); + address32); } } } @@ -530,18 +558,6 @@ static void acpi_tb_validate_fadt(void) length)); } } - - /* - * If both 32- and 64-bit addresses are valid (non-zero), - * they must match - */ - if (address64->address && *address32 && - (address64->address != (u64) * address32)) { - ACPI_ERROR((AE_INFO, - "32/64X address mismatch in %s: %8.8X/%8.8X%8.8X, using 64X", - name, *address32, - ACPI_FORMAT_UINT64(address64->address))); - } } }