ACPICA: Add option to favor 32-bit FADT addresses.

This change adds an option to favor 32-bit FADT addresses when there
is a conflict between the 32-bit and 64-bit versions of the same
address. The default behavior is to use the 64-bit version in accordance
with the ACPI specification. This can now be overridden via the
AcpiGbl_Use32BitFadtAddresses flag. Lv Zheng.

Also, the "Convert FADT" and "Verify FADT" functions have been merged to
simplify the code, make it easier to understand, and make it easier to
maintain. Bob Moore.

References: https://bugs.acpica.org/show_bug.cgi?id=885
References: https://bugs.acpica.org/show_bug.cgi?id=993
Original-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Bob Moore <robert.moore@intel.com>
Signed-off-by: Lv Zheng <lv.zheng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

3 files changed, 194 insertions, 152 deletions

diff --git a/drivers/acpi/acpica/acglobal.h b/drivers/acpi/acpica/acglobal.h
index cffb45742aa5..268699879904 100644
--- a/drivers/acpi/acpica/acglobal.h
+++ b/drivers/acpi/acpica/acglobal.h
@@ -127,6 +127,16 @@ u8 ACPI_INIT_GLOBAL(acpi_gbl_copy_dsdt_locally, FALSE);
 u8 ACPI_INIT_GLOBAL(acpi_gbl_do_not_use_xsdt, FALSE);
 
 /*
+ * Optionally use 32-bit FADT addresses if and when there is a conflict
+ * (address mismatch) between the 32-bit and 64-bit versions of the
+ * address. Although ACPICA adheres to the ACPI specification which
+ * requires the use of the corresponding 64-bit address if it is non-zero,
+ * some machines have been found to have a corrupted non-zero 64-bit
+ * address. Default is FALSE, do not favor the 32-bit addresses.
+ */
+u8 ACPI_INIT_GLOBAL(acpi_gbl_use32_bit_fadt_addresses, FALSE);
+
+/*
  * Optionally truncate I/O addresses to 16 bits. Provides compatibility
  * with other ACPI implementations. NOTE: During ACPICA initialization,
  * this value is set to TRUE if any Windows OSI strings have been
diff --git a/drivers/acpi/acpica/tbfadt.c b/drivers/acpi/acpica/tbfadt.c
index 9d99f2189693..8f89263ac47e 100644
--- a/drivers/acpi/acpica/tbfadt.c
+++ b/drivers/acpi/acpica/tbfadt.c
@@ -56,10 +56,11 @@ acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
 
 static void acpi_tb_convert_fadt(void);
 
-static void acpi_tb_validate_fadt(void);
-
 static void acpi_tb_setup_fadt_registers(void);
 
+static u64
+acpi_tb_select_address(char *register_name, u32 address32, u64 address64);
+
 /* Table for conversion of FADT to common internal format and FADT validation */
 
 typedef struct acpi_fadt_info {
@@ -175,6 +176,7 @@ static struct acpi_fadt_pm_info fadt_pm_info_table[] = {
  *              space_id            - ACPI Space ID for this register
  *              byte_width          - Width of this register
  *              address             - Address of the register
+ *              register_name       - ASCII name of the ACPI register
  *
  * RETURN:      None
  *
@@ -220,6 +222,68 @@ acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
 
 /*******************************************************************************
  *
+ * FUNCTION:    acpi_tb_select_address
+ *
+ * PARAMETERS:  register_name       - ASCII name of the ACPI register
+ *              address32           - 32-bit address of the register
+ *              address64           - 64-bit address of the register
+ *
+ * RETURN:      The resolved 64-bit address
+ *
+ * DESCRIPTION: Select between 32-bit and 64-bit versions of addresses within
+ *              the FADT. Used for the FACS and DSDT addresses.
+ *
+ * NOTES:
+ *
+ * Check for FACS and DSDT address mismatches. An address mismatch between
+ * the 32-bit and 64-bit address fields (FIRMWARE_CTRL/X_FIRMWARE_CTRL and
+ * DSDT/X_DSDT) could be a corrupted address field or it might indicate
+ * the presence of two FACS or two DSDT tables.
+ *
+ * November 2013:
+ * By default, as per the ACPICA specification, a valid 64-bit address is
+ * used regardless of the value of the 32-bit address. However, this
+ * behavior can be overridden via the acpi_gbl_use32_bit_fadt_addresses flag.
+ *
+ ******************************************************************************/
+
+static u64
+acpi_tb_select_address(char *register_name, u32 address32, u64 address64)
+{
+
+	if (!address64) {
+
+		/* 64-bit address is zero, use 32-bit address */
+
+		return ((u64)address32);
+	}
+
+	if (address32 && (address64 != (u64)address32)) {
+
+		/* Address mismatch between 32-bit and 64-bit versions */
+
+		ACPI_BIOS_WARNING((AE_INFO,
+				   "32/64X %s address mismatch in FADT: "
+				   "0x%8.8X/0x%8.8X%8.8X, using %u-bit address",
+				   register_name, address32,
+				   ACPI_FORMAT_UINT64(address64),
+				   acpi_gbl_use32_bit_fadt_addresses ? 32 :
+				   64));
+
+		/* 32-bit address override */
+
+		if (acpi_gbl_use32_bit_fadt_addresses) {
+			return ((u64)address32);
+		}
+	}
+
+	/* Default is to use the 64-bit address */
+
+	return (address64);
+}
+
+/*******************************************************************************
+ *
  * FUNCTION:    acpi_tb_parse_fadt
  *
  * PARAMETERS:  table_index         - Index for the FADT
@@ -331,10 +395,6 @@ void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length)
 
 	acpi_tb_convert_fadt();
 
-	/* Validate FADT values now, before we make any changes */
-
-	acpi_tb_validate_fadt();
-
 	/* Initialize the global ACPI register structures */
 
 	acpi_tb_setup_fadt_registers();
@@ -344,66 +404,55 @@ void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length)
  *
  * FUNCTION:    acpi_tb_convert_fadt
  *
- * PARAMETERS:  None, uses acpi_gbl_FADT
+ * PARAMETERS:  none - acpi_gbl_FADT is used.
  *
  * RETURN:      None
  *
  * DESCRIPTION: Converts all versions of the FADT to a common internal format.
- *              Expand 32-bit addresses to 64-bit as necessary.
+ *              Expand 32-bit addresses to 64-bit as necessary. Also validate
+ *              important fields within the FADT.
  *
- * NOTE:        acpi_gbl_FADT must be of size (struct acpi_table_fadt),
- *              and must contain a copy of the actual FADT.
+ * NOTE:        acpi_gbl_FADT must be of size (struct acpi_table_fadt), and must
+ *              contain a copy of the actual BIOS-provided FADT.
  *
  * Notes on 64-bit register addresses:
  *
  * After this FADT conversion, later ACPICA code will only use the 64-bit "X"
  * fields of the FADT for all ACPI register addresses.
  *
- * The 64-bit "X" fields are optional extensions to the original 32-bit FADT
+ * 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.
+ * 32-bit V1.0 fields to the 64-bit X fields if the the 64-bit X field is
+ * originally zero.
  *
- * For ACPI 1.0 FADTs, all 32-bit address fields are expanded to the
- * corresponding "X" fields in the internal FADT.
+ * For ACPI 1.0 FADTs (that contain no 64-bit addresses), all 32-bit address
+ * fields are expanded to the corresponding 64-bit X fields in the internal
+ * common 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.
+ * to the corresponding 64-bit X fields, if the 64-bit field is originally
+ * zero. Adhering to the ACPI specification, we completely ignore the 32-bit
+ * field if the 64-bit field is valid, regardless of whether the host OS is
+ * 32-bit or 64-bit.
+ *
+ * Possible additional checks:
+ *  (acpi_gbl_FADT.pm1_event_length >= 4)
+ *  (acpi_gbl_FADT.pm1_control_length >= 2)
+ *  (acpi_gbl_FADT.pm_timer_length >= 4)
+ *  Gpe block lengths must be multiple of 2
  *
  ******************************************************************************/
 
 static void acpi_tb_convert_fadt(void)
 {
+	char *name;
 	struct acpi_generic_address *address64;
 	u32 address32;
+	u8 length;
 	u32 i;
 
 	/*
-	 * Expand the 32-bit FACS and DSDT addresses to 64-bit as necessary.
-	 * Later code will always use the X 64-bit field. Also, check for an
-	 * address mismatch between the 32-bit and 64-bit address fields
-	 * (FIRMWARE_CTRL/X_FIRMWARE_CTRL, DSDT/X_DSDT) which would indicate
-	 * the presence of two FACS or two DSDT tables.
-	 */
-	if (!acpi_gbl_FADT.Xfacs) {
-		acpi_gbl_FADT.Xfacs = (u64) acpi_gbl_FADT.facs;
-	} else if (acpi_gbl_FADT.facs &&
-		   (acpi_gbl_FADT.Xfacs != (u64) acpi_gbl_FADT.facs)) {
-		ACPI_WARNING((AE_INFO,
-		    "32/64 FACS address mismatch in FADT - two FACS tables!"));
-	}
-
-	if (!acpi_gbl_FADT.Xdsdt) {
-		acpi_gbl_FADT.Xdsdt = (u64) acpi_gbl_FADT.dsdt;
-	} else if (acpi_gbl_FADT.dsdt &&
-		   (acpi_gbl_FADT.Xdsdt != (u64) acpi_gbl_FADT.dsdt)) {
-		ACPI_WARNING((AE_INFO,
-		    "32/64 DSDT address mismatch in FADT - two DSDT tables!"));
-	}
-
-	/*
 	 * For ACPI 1.0 FADTs (revision 1 or 2), ensure that reserved fields which
 	 * should be zero are indeed zero. This will workaround BIOSs that
 	 * inadvertently place values in these fields.
@@ -421,119 +470,24 @@ static void acpi_tb_convert_fadt(void)
 		acpi_gbl_FADT.boot_flags = 0;
 	}
 
-	/* Update the local FADT table header length */
-
-	acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);
-
 	/*
-	 * 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.
+	 * Now we can update the local FADT length to the length of the
+	 * current FADT version as defined by the ACPI specification.
+	 * Thus, we will have a common FADT internally.
 	 */
-	for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
-		address32 = *ACPI_ADD_PTR(u32,
-					  &acpi_gbl_FADT,
-					  fadt_info_table[i].address32);
-
-		address64 = ACPI_ADD_PTR(struct acpi_generic_address,
-					 &acpi_gbl_FADT,
-					 fadt_info_table[i].address64);
-
-		/*
-		 * If both 32- and 64-bit addresses are valid (non-zero),
-		 * they must match.
-		 */
-		if (address64->address && address32 &&
-		    (address64->address != (u64)address32)) {
-			ACPI_BIOS_ERROR((AE_INFO,
-					 "32/64X address mismatch in FADT/%s: "
-					 "0x%8.8X/0x%8.8X%8.8X, using 32",
-					 fadt_info_table[i].name, address32,
-					 ACPI_FORMAT_UINT64(address64->
-							    address)));
-		}
-
-		/* Always use 32-bit address if it is valid (non-null) */
-
-		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) address32,
-						     fadt_info_table[i].name);
-		}
-	}
-}
-
-/*******************************************************************************
- *
- * FUNCTION:    acpi_tb_validate_fadt
- *
- * PARAMETERS:  table           - Pointer to the FADT to be validated
- *
- * RETURN:      None
- *
- * DESCRIPTION: Validate various important fields within the FADT. If a problem
- *              is found, issue a message, but no status is returned.
- *              Used by both the table manager and the disassembler.
- *
- * Possible additional checks:
- * (acpi_gbl_FADT.pm1_event_length >= 4)
- * (acpi_gbl_FADT.pm1_control_length >= 2)
- * (acpi_gbl_FADT.pm_timer_length >= 4)
- * Gpe block lengths must be multiple of 2
- *
- ******************************************************************************/
-
-static void acpi_tb_validate_fadt(void)
-{
-	char *name;
-	struct acpi_generic_address *address64;
-	u8 length;
-	u32 i;
+	acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);
 
 	/*
-	 * Check for FACS and DSDT address mismatches. An address mismatch between
-	 * the 32-bit and 64-bit address fields (FIRMWARE_CTRL/X_FIRMWARE_CTRL and
-	 * DSDT/X_DSDT) would indicate the presence of two FACS or two DSDT tables.
+	 * Expand the 32-bit FACS and DSDT addresses to 64-bit as necessary.
+	 * Later ACPICA code will always use the X 64-bit field.
 	 */
-	if (acpi_gbl_FADT.facs &&
-	    (acpi_gbl_FADT.Xfacs != (u64)acpi_gbl_FADT.facs)) {
-		ACPI_BIOS_WARNING((AE_INFO,
-				   "32/64X FACS address mismatch in FADT - "
-				   "0x%8.8X/0x%8.8X%8.8X, using 32",
-				   acpi_gbl_FADT.facs,
-				   ACPI_FORMAT_UINT64(acpi_gbl_FADT.Xfacs)));
-
-		acpi_gbl_FADT.Xfacs = (u64)acpi_gbl_FADT.facs;
-	}
-
-	if (acpi_gbl_FADT.dsdt &&
-	    (acpi_gbl_FADT.Xdsdt != (u64)acpi_gbl_FADT.dsdt)) {
-		ACPI_BIOS_WARNING((AE_INFO,
-				   "32/64X DSDT address mismatch in FADT - "
-				   "0x%8.8X/0x%8.8X%8.8X, using 32",
-				   acpi_gbl_FADT.dsdt,
-				   ACPI_FORMAT_UINT64(acpi_gbl_FADT.Xdsdt)));
+	acpi_gbl_FADT.Xfacs = acpi_tb_select_address("FACS",
+						     acpi_gbl_FADT.facs,
+						     acpi_gbl_FADT.Xfacs);
 
-		acpi_gbl_FADT.Xdsdt = (u64)acpi_gbl_FADT.dsdt;
-	}
+	acpi_gbl_FADT.Xdsdt = acpi_tb_select_address("DSDT",
+						     acpi_gbl_FADT.dsdt,
+						     acpi_gbl_FADT.Xdsdt);
 
 	/* If Hardware Reduced flag is set, we are all done */
 
@@ -545,18 +499,95 @@ static void acpi_tb_validate_fadt(void)
 
 	for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
 		/*
-		 * Generate pointer to the 64-bit address, get the register
-		 * length (width) and the register name
+		 * Get the 32-bit and 64-bit addresses, as well as the register
+		 * length and register name.
 		 */
+		address32 = *ACPI_ADD_PTR(u32,
+					  &acpi_gbl_FADT,
+					  fadt_info_table[i].address32);
+
 		address64 = ACPI_ADD_PTR(struct acpi_generic_address,
 					 &acpi_gbl_FADT,
 					 fadt_info_table[i].address64);
-		length =
-		    *ACPI_ADD_PTR(u8, &acpi_gbl_FADT,
-				  fadt_info_table[i].length);
+
+		length = *ACPI_ADD_PTR(u8,
+				       &acpi_gbl_FADT,
+				       fadt_info_table[i].length);
+
 		name = fadt_info_table[i].name;
 
 		/*
+		 * 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.
+		 *
+		 * November 2013:
+		 * Now always use the 64-bit address if it is valid (non-zero), in
+		 * accordance with the ACPI specification which states that a 64-bit
+		 * address supersedes the 32-bit version. This behavior can be
+		 * overridden by the acpi_gbl_use32_bit_fadt_addresses flag.
+		 *
+		 * During 64-bit address construction and verification,
+		 * these cases are handled:
+		 *
+		 * Address32 zero, Address64 [don't care]   - Use Address64
+		 *
+		 * Address32 non-zero, Address64 zero       - Copy/use Address32
+		 * Address32 non-zero == Address64 non-zero - Use Address64
+		 * Address32 non-zero != Address64 non-zero - Warning, use Address64
+		 *
+		 * Override: if acpi_gbl_use32_bit_fadt_addresses is TRUE, and:
+		 * Address32 non-zero != Address64 non-zero - Warning, copy/use Address32
+		 *
+		 * Note: space_id is always I/O for 32-bit legacy address fields
+		 */
+		if (address32) {
+			if (!address64->address) {
+
+				/* 64-bit address is zero, use 32-bit address */
+
+				acpi_tb_init_generic_address(address64,
+							     ACPI_ADR_SPACE_SYSTEM_IO,
+							     *ACPI_ADD_PTR(u8,
+									   &acpi_gbl_FADT,
+									   fadt_info_table
+									   [i].
+									   length),
+							     (u64)address32,
+							     name);
+			} else if (address64->address != (u64)address32) {
+
+				/* Address mismatch */
+
+				ACPI_BIOS_WARNING((AE_INFO,
+						   "32/64X address mismatch in FADT/%s: "
+						   "0x%8.8X/0x%8.8X%8.8X, using %u-bit address",
+						   name, address32,
+						   ACPI_FORMAT_UINT64
+						   (address64->address),
+						   acpi_gbl_use32_bit_fadt_addresses
+						   ? 32 : 64));
+
+				if (acpi_gbl_use32_bit_fadt_addresses) {
+
+					/* 32-bit address override */
+
+					acpi_tb_init_generic_address(address64,
+								     ACPI_ADR_SPACE_SYSTEM_IO,
+								     *ACPI_ADD_PTR
+								     (u8,
+								      &acpi_gbl_FADT,
+								      fadt_info_table
+								      [i].
+								      length),
+								     (u64)
+								     address32,
+								     name);
+				}
+			}
+		}
+
+		/*
 		 * For each extended field, check for length mismatch between the
 		 * legacy length field and the corresponding 64-bit X length field.
 		 * Note: If the legacy length field is > 0xFF bits, ignore this
diff --git a/include/acpi/acpixf.h b/include/acpi/acpixf.h
index 30b01f889538..01ba80b1f91f 100644
--- a/include/acpi/acpixf.h
+++ b/include/acpi/acpixf.h
@@ -82,6 +82,7 @@ extern u8 acpi_gbl_enable_interpreter_slack;
 extern u32 acpi_gbl_trace_flags;
 extern acpi_name acpi_gbl_trace_method_name;
 extern u8 acpi_gbl_truncate_io_addresses;
+extern u8 acpi_gbl_use32_bit_fadt_addresses;
 extern u8 acpi_gbl_use_default_register_widths;
 
 /*