Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 722 insertions, 0 deletions

diff --git a/drivers/acpi/acpica/tbfadt.c b/drivers/acpi/acpica/tbfadt.c
new file mode 100644
index 000000000..99d325a51
--- /dev/null
+++ b/drivers/acpi/acpica/tbfadt.c
@@ -0,0 +1,722 @@
+// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.0
+/******************************************************************************
+ *
+ * Module Name: tbfadt   - FADT table utilities
+ *
+ * Copyright (C) 2000 - 2018, Intel Corp.
+ *
+ *****************************************************************************/
+
+#include <acpi/acpi.h>
+#include "accommon.h"
+#include "actables.h"
+
+#define _COMPONENT          ACPI_TABLES
+ACPI_MODULE_NAME("tbfadt")
+
+/* Local prototypes */
+static void
+acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
+			     u8 space_id,
+			     u8 byte_width,
+			     u64 address, const char *register_name, u8 flags);
+
+static void acpi_tb_convert_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 {
+	const char *name;
+	u16 address64;
+	u16 address32;
+	u16 length;
+	u8 default_length;
+	u8 flags;
+
+} acpi_fadt_info;
+
+#define ACPI_FADT_OPTIONAL          0
+#define ACPI_FADT_REQUIRED          1
+#define ACPI_FADT_SEPARATE_LENGTH   2
+#define ACPI_FADT_GPE_REGISTER      4
+
+static struct acpi_fadt_info fadt_info_table[] = {
+	{"Pm1aEventBlock",
+	 ACPI_FADT_OFFSET(xpm1a_event_block),
+	 ACPI_FADT_OFFSET(pm1a_event_block),
+	 ACPI_FADT_OFFSET(pm1_event_length),
+	 ACPI_PM1_REGISTER_WIDTH * 2,	/* Enable + Status register */
+	 ACPI_FADT_REQUIRED},
+
+	{"Pm1bEventBlock",
+	 ACPI_FADT_OFFSET(xpm1b_event_block),
+	 ACPI_FADT_OFFSET(pm1b_event_block),
+	 ACPI_FADT_OFFSET(pm1_event_length),
+	 ACPI_PM1_REGISTER_WIDTH * 2,	/* Enable + Status register */
+	 ACPI_FADT_OPTIONAL},
+
+	{"Pm1aControlBlock",
+	 ACPI_FADT_OFFSET(xpm1a_control_block),
+	 ACPI_FADT_OFFSET(pm1a_control_block),
+	 ACPI_FADT_OFFSET(pm1_control_length),
+	 ACPI_PM1_REGISTER_WIDTH,
+	 ACPI_FADT_REQUIRED},
+
+	{"Pm1bControlBlock",
+	 ACPI_FADT_OFFSET(xpm1b_control_block),
+	 ACPI_FADT_OFFSET(pm1b_control_block),
+	 ACPI_FADT_OFFSET(pm1_control_length),
+	 ACPI_PM1_REGISTER_WIDTH,
+	 ACPI_FADT_OPTIONAL},
+
+	{"Pm2ControlBlock",
+	 ACPI_FADT_OFFSET(xpm2_control_block),
+	 ACPI_FADT_OFFSET(pm2_control_block),
+	 ACPI_FADT_OFFSET(pm2_control_length),
+	 ACPI_PM2_REGISTER_WIDTH,
+	 ACPI_FADT_SEPARATE_LENGTH},
+
+	{"PmTimerBlock",
+	 ACPI_FADT_OFFSET(xpm_timer_block),
+	 ACPI_FADT_OFFSET(pm_timer_block),
+	 ACPI_FADT_OFFSET(pm_timer_length),
+	 ACPI_PM_TIMER_WIDTH,
+	 ACPI_FADT_SEPARATE_LENGTH},	/* ACPI 5.0A: Timer is optional */
+
+	{"Gpe0Block",
+	 ACPI_FADT_OFFSET(xgpe0_block),
+	 ACPI_FADT_OFFSET(gpe0_block),
+	 ACPI_FADT_OFFSET(gpe0_block_length),
+	 0,
+	 ACPI_FADT_SEPARATE_LENGTH | ACPI_FADT_GPE_REGISTER},
+
+	{"Gpe1Block",
+	 ACPI_FADT_OFFSET(xgpe1_block),
+	 ACPI_FADT_OFFSET(gpe1_block),
+	 ACPI_FADT_OFFSET(gpe1_block_length),
+	 0,
+	 ACPI_FADT_SEPARATE_LENGTH | ACPI_FADT_GPE_REGISTER}
+};
+
+#define ACPI_FADT_INFO_ENTRIES \
+			(sizeof (fadt_info_table) / sizeof (struct acpi_fadt_info))
+
+/* Table used to split Event Blocks into separate status/enable registers */
+
+typedef struct acpi_fadt_pm_info {
+	struct acpi_generic_address *target;
+	u16 source;
+	u8 register_num;
+
+} acpi_fadt_pm_info;
+
+static struct acpi_fadt_pm_info fadt_pm_info_table[] = {
+	{&acpi_gbl_xpm1a_status,
+	 ACPI_FADT_OFFSET(xpm1a_event_block),
+	 0},
+
+	{&acpi_gbl_xpm1a_enable,
+	 ACPI_FADT_OFFSET(xpm1a_event_block),
+	 1},
+
+	{&acpi_gbl_xpm1b_status,
+	 ACPI_FADT_OFFSET(xpm1b_event_block),
+	 0},
+
+	{&acpi_gbl_xpm1b_enable,
+	 ACPI_FADT_OFFSET(xpm1b_event_block),
+	 1}
+};
+
+#define ACPI_FADT_PM_INFO_ENTRIES \
+			(sizeof (fadt_pm_info_table) / sizeof (struct acpi_fadt_pm_info))
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_init_generic_address
+ *
+ * PARAMETERS:  generic_address     - GAS struct to be initialized
+ *              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
+ *
+ * DESCRIPTION: Initialize a Generic Address Structure (GAS)
+ *              See the ACPI specification for a full description and
+ *              definition of this structure.
+ *
+ ******************************************************************************/
+
+static void
+acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,
+			     u8 space_id,
+			     u8 byte_width,
+			     u64 address, const char *register_name, u8 flags)
+{
+	u8 bit_width;
+
+	/*
+	 * Bit width field in the GAS is only one byte long, 255 max.
+	 * Check for bit_width overflow in GAS.
+	 */
+	bit_width = (u8)(byte_width * 8);
+	if (byte_width > 31) {	/* (31*8)=248, (32*8)=256 */
+		/*
+		 * No error for GPE blocks, because we do not use the bit_width
+		 * for GPEs, the legacy length (byte_width) is used instead to
+		 * allow for a large number of GPEs.
+		 */
+		if (!(flags & ACPI_FADT_GPE_REGISTER)) {
+			ACPI_ERROR((AE_INFO,
+				    "%s - 32-bit FADT register is too long (%u bytes, %u bits) "
+				    "to convert to GAS struct - 255 bits max, truncating",
+				    register_name, byte_width,
+				    (byte_width * 8)));
+		}
+
+		bit_width = 255;
+	}
+
+	/*
+	 * The 64-bit Address field is non-aligned in the byte packed
+	 * GAS struct.
+	 */
+	ACPI_MOVE_64_TO_64(&generic_address->address, &address);
+
+	/* All other fields are byte-wide */
+
+	generic_address->space_id = space_id;
+	generic_address->bit_width = bit_width;
+	generic_address->bit_offset = 0;
+	generic_address->access_width = 0;	/* Access width ANY */
+}
+
+/*******************************************************************************
+ *
+ * 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:  None
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Initialize the FADT, DSDT and FACS tables
+ *              (FADT contains the addresses of the DSDT and FACS)
+ *
+ ******************************************************************************/
+
+void acpi_tb_parse_fadt(void)
+{
+	u32 length;
+	struct acpi_table_header *table;
+	struct acpi_table_desc *fadt_desc;
+	acpi_status status;
+
+	/*
+	 * The FADT has multiple versions with different lengths,
+	 * and it contains pointers to both the DSDT and FACS tables.
+	 *
+	 * Get a local copy of the FADT and convert it to a common format
+	 * Map entire FADT, assumed to be smaller than one page.
+	 */
+	fadt_desc = &acpi_gbl_root_table_list.tables[acpi_gbl_fadt_index];
+	status = acpi_tb_get_table(fadt_desc, &table);
+	if (ACPI_FAILURE(status)) {
+		return;
+	}
+	length = fadt_desc->length;
+
+	/*
+	 * Validate the FADT checksum before we copy the table. Ignore
+	 * checksum error as we want to try to get the DSDT and FACS.
+	 */
+	(void)acpi_tb_verify_checksum(table, length);
+
+	/* Create a local copy of the FADT in common ACPI 2.0+ format */
+
+	acpi_tb_create_local_fadt(table, length);
+
+	/* All done with the real FADT, unmap it */
+
+	acpi_tb_put_table(fadt_desc);
+
+	/* Obtain the DSDT and FACS tables via their addresses within the FADT */
+
+	acpi_tb_install_standard_table((acpi_physical_address)acpi_gbl_FADT.
+				       Xdsdt,
+				       ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
+				       FALSE, TRUE, &acpi_gbl_dsdt_index);
+
+	/* If Hardware Reduced flag is set, there is no FACS */
+
+	if (!acpi_gbl_reduced_hardware) {
+		if (acpi_gbl_FADT.facs) {
+			acpi_tb_install_standard_table((acpi_physical_address)
+						       acpi_gbl_FADT.facs,
+						       ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
+						       FALSE, TRUE,
+						       &acpi_gbl_facs_index);
+		}
+		if (acpi_gbl_FADT.Xfacs) {
+			acpi_tb_install_standard_table((acpi_physical_address)
+						       acpi_gbl_FADT.Xfacs,
+						       ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,
+						       FALSE, TRUE,
+						       &acpi_gbl_xfacs_index);
+		}
+	}
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_create_local_fadt
+ *
+ * PARAMETERS:  table               - Pointer to BIOS FADT
+ *              length              - Length of the table
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Get a local copy of the FADT and convert it to a common format.
+ *              Performs validation on some important FADT fields.
+ *
+ * NOTE:        We create a local copy of the FADT regardless of the version.
+ *
+ ******************************************************************************/
+
+void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length)
+{
+	/*
+	 * Check if the FADT is larger than the largest table that we expect
+	 * (typically the current ACPI specification version). If so, truncate
+	 * the table, and issue a warning.
+	 */
+	if (length > sizeof(struct acpi_table_fadt)) {
+		ACPI_BIOS_WARNING((AE_INFO,
+				   "FADT (revision %u) is longer than %s length, "
+				   "truncating length %u to %u",
+				   table->revision, ACPI_FADT_CONFORMANCE,
+				   length,
+				   (u32)sizeof(struct acpi_table_fadt)));
+	}
+
+	/* Clear the entire local FADT */
+
+	memset(&acpi_gbl_FADT, 0, sizeof(struct acpi_table_fadt));
+
+	/* Copy the original FADT, up to sizeof (struct acpi_table_fadt) */
+
+	memcpy(&acpi_gbl_FADT, table,
+	       ACPI_MIN(length, sizeof(struct acpi_table_fadt)));
+
+	/* Take a copy of the Hardware Reduced flag */
+
+	acpi_gbl_reduced_hardware = FALSE;
+	if (acpi_gbl_FADT.flags & ACPI_FADT_HW_REDUCED) {
+		acpi_gbl_reduced_hardware = TRUE;
+	}
+
+	/* Convert the local copy of the FADT to the common internal format */
+
+	acpi_tb_convert_fadt();
+
+	/* Initialize the global ACPI register structures */
+
+	acpi_tb_setup_fadt_registers();
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_convert_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. 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 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
+ * 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 to the 64-bit X fields if the 64-bit X field is originally
+ * zero.
+ *
+ * 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, 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)
+{
+	const char *name;
+	struct acpi_generic_address *address64;
+	u32 address32;
+	u8 length;
+	u8 flags;
+	u32 i;
+
+	/*
+	 * 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.
+	 *
+	 * The ACPI 1.0 reserved fields that will be zeroed are the bytes located
+	 * at offset 45, 55, 95, and the word located at offset 109, 110.
+	 *
+	 * Note: The FADT revision value is unreliable. Only the length can be
+	 * trusted.
+	 */
+	if (acpi_gbl_FADT.header.length <= ACPI_FADT_V2_SIZE) {
+		acpi_gbl_FADT.preferred_profile = 0;
+		acpi_gbl_FADT.pstate_control = 0;
+		acpi_gbl_FADT.cst_control = 0;
+		acpi_gbl_FADT.boot_flags = 0;
+	}
+
+	/*
+	 * 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.
+	 */
+	acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);
+
+	/*
+	 * Expand the 32-bit DSDT addresses to 64-bit as necessary.
+	 * Later ACPICA code will always use the X 64-bit field.
+	 */
+	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 */
+
+	if (acpi_gbl_reduced_hardware) {
+		return;
+	}
+
+	/* Examine all of the 64-bit extended address fields (X fields) */
+
+	for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {
+		/*
+		 * 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);
+
+		name = fadt_info_table[i].name;
+		flags = fadt_info_table[i].flags;
+
+		/*
+		 * 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
+		 *
+		 * No override: if acpi_gbl_use32_bit_fadt_addresses is FALSE, and:
+		 * 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 zero       - Copy/use Address32
+		 * Address32 non-zero == Address64 non-zero - Copy/use Address32
+		 * 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) {
+				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));
+				}
+
+				/*
+				 * 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 check. (GPE registers can be larger than the
+				 * 64-bit GAS structure can accomodate, 0xFF bits).
+				 */
+				if ((ACPI_MUL_8(length) <= ACPI_UINT8_MAX) &&
+				    (address64->bit_width !=
+				     ACPI_MUL_8(length))) {
+					ACPI_BIOS_WARNING((AE_INFO,
+							   "32/64X length mismatch in FADT/%s: %u/%u",
+							   name,
+							   ACPI_MUL_8(length),
+							   address64->
+							   bit_width));
+				}
+			}
+
+			/*
+			 * Hardware register access code always uses the 64-bit fields.
+			 * So if the 64-bit field is zero or is to be overridden,
+			 * initialize it with the 32-bit fields.
+			 * Note that when the 32-bit address favor is specified, the
+			 * 64-bit fields are always re-initialized so that
+			 * access_size/bit_width/bit_offset fields can be correctly
+			 * configured to the values to trigger a 32-bit compatible
+			 * access mode in the hardware register access code.
+			 */
+			if (!address64->address
+			    || acpi_gbl_use32_bit_fadt_addresses) {
+				acpi_tb_init_generic_address(address64,
+							     ACPI_ADR_SPACE_SYSTEM_IO,
+							     length,
+							     (u64)address32,
+							     name, flags);
+			}
+		}
+
+		if (fadt_info_table[i].flags & ACPI_FADT_REQUIRED) {
+			/*
+			 * Field is required (Pm1a_event, Pm1a_control).
+			 * Both the address and length must be non-zero.
+			 */
+			if (!address64->address || !length) {
+				ACPI_BIOS_ERROR((AE_INFO,
+						 "Required FADT field %s has zero address and/or length: "
+						 "0x%8.8X%8.8X/0x%X",
+						 name,
+						 ACPI_FORMAT_UINT64(address64->
+								    address),
+						 length));
+			}
+		} else if (fadt_info_table[i].flags & ACPI_FADT_SEPARATE_LENGTH) {
+			/*
+			 * Field is optional (Pm2_control, GPE0, GPE1) AND has its own
+			 * length field. If present, both the address and length must
+			 * be valid.
+			 */
+			if ((address64->address && !length) ||
+			    (!address64->address && length)) {
+				ACPI_BIOS_WARNING((AE_INFO,
+						   "Optional FADT field %s has valid %s but zero %s: "
+						   "0x%8.8X%8.8X/0x%X", name,
+						   (length ? "Length" :
+						    "Address"),
+						   (length ? "Address" :
+						    "Length"),
+						   ACPI_FORMAT_UINT64
+						   (address64->address),
+						   length));
+			}
+		}
+	}
+}
+
+/*******************************************************************************
+ *
+ * FUNCTION:    acpi_tb_setup_fadt_registers
+ *
+ * PARAMETERS:  None, uses acpi_gbl_FADT.
+ *
+ * RETURN:      None
+ *
+ * DESCRIPTION: Initialize global ACPI PM1 register definitions. Optionally,
+ *              force FADT register definitions to their default lengths.
+ *
+ ******************************************************************************/
+
+static void acpi_tb_setup_fadt_registers(void)
+{
+	struct acpi_generic_address *target64;
+	struct acpi_generic_address *source64;
+	u8 pm1_register_byte_width;
+	u32 i;
+
+	/*
+	 * Optionally check all register lengths against the default values and
+	 * update them if they are incorrect.
+	 */
+	if (acpi_gbl_use_default_register_widths) {
+		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);
+
+			/*
+			 * If a valid register (Address != 0) and the (default_length > 0)
+			 * (Not a GPE register), then check the width against the default.
+			 */
+			if ((target64->address) &&
+			    (fadt_info_table[i].default_length > 0) &&
+			    (fadt_info_table[i].default_length !=
+			     target64->bit_width)) {
+				ACPI_BIOS_WARNING((AE_INFO,
+						   "Invalid length for FADT/%s: %u, using default %u",
+						   fadt_info_table[i].name,
+						   target64->bit_width,
+						   fadt_info_table[i].
+						   default_length));
+
+				/* Incorrect size, set width to the default */
+
+				target64->bit_width =
+				    fadt_info_table[i].default_length;
+			}
+		}
+	}
+
+	/*
+	 * Get the length of the individual PM1 registers (enable and status).
+	 * Each register is defined to be (event block length / 2). Extra divide
+	 * by 8 converts bits to bytes.
+	 */
+	pm1_register_byte_width = (u8)
+	    ACPI_DIV_16(acpi_gbl_FADT.xpm1a_event_block.bit_width);
+
+	/*
+	 * Calculate separate GAS structs for the PM1x (A/B) Status and Enable
+	 * registers. These addresses do not appear (directly) in the FADT, so it
+	 * is useful to pre-calculate them from the PM1 Event Block definitions.
+	 *
+	 * The PM event blocks are split into two register blocks, first is the
+	 * PM Status Register block, followed immediately by the PM Enable
+	 * Register block. Each is of length (pm1_event_length/2)
+	 *
+	 * Note: The PM1A event block is required by the ACPI specification.
+	 * However, the PM1B event block is optional and is rarely, if ever,
+	 * used.
+	 */
+
+	for (i = 0; i < ACPI_FADT_PM_INFO_ENTRIES; i++) {
+		source64 =
+		    ACPI_ADD_PTR(struct acpi_generic_address, &acpi_gbl_FADT,
+				 fadt_pm_info_table[i].source);
+
+		if (source64->address) {
+			acpi_tb_init_generic_address(fadt_pm_info_table[i].
+						     target, source64->space_id,
+						     pm1_register_byte_width,
+						     source64->address +
+						     (fadt_pm_info_table[i].
+						      register_num *
+						      pm1_register_byte_width),
+						     "PmRegisters", 0);
+		}
+	}
+}