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1// SPDX-License-Identifier: BSD-3-Clause OR GPL-2.02/******************************************************************************3 *4 * Module Name: tbfadt   - FADT table utilities5 *6 * Copyright (C) 2000 - 2023, Intel Corp.7 *8 *****************************************************************************/9 10#include <acpi/acpi.h>11#include "accommon.h"12#include "actables.h"13 14#define _COMPONENT          ACPI_TABLES15ACPI_MODULE_NAME("tbfadt")16 17/* Local prototypes */18static void19acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,20			     u8 space_id,21			     u8 byte_width,22			     u64 address, const char *register_name, u8 flags);23 24static void acpi_tb_convert_fadt(void);25 26static void acpi_tb_setup_fadt_registers(void);27 28static u6429acpi_tb_select_address(char *register_name, u32 address32, u64 address64);30 31/* Table for conversion of FADT to common internal format and FADT validation */32 33typedef struct acpi_fadt_info {34	const char *name;35	u16 address64;36	u16 address32;37	u16 length;38	u8 default_length;39	u8 flags;40 41} acpi_fadt_info;42 43#define ACPI_FADT_OPTIONAL          044#define ACPI_FADT_REQUIRED          145#define ACPI_FADT_SEPARATE_LENGTH   246#define ACPI_FADT_GPE_REGISTER      447 48static struct acpi_fadt_info fadt_info_table[] = {49	{"Pm1aEventBlock",50	 ACPI_FADT_OFFSET(xpm1a_event_block),51	 ACPI_FADT_OFFSET(pm1a_event_block),52	 ACPI_FADT_OFFSET(pm1_event_length),53	 ACPI_PM1_REGISTER_WIDTH * 2,	/* Enable + Status register */54	 ACPI_FADT_REQUIRED},55 56	{"Pm1bEventBlock",57	 ACPI_FADT_OFFSET(xpm1b_event_block),58	 ACPI_FADT_OFFSET(pm1b_event_block),59	 ACPI_FADT_OFFSET(pm1_event_length),60	 ACPI_PM1_REGISTER_WIDTH * 2,	/* Enable + Status register */61	 ACPI_FADT_OPTIONAL},62 63	{"Pm1aControlBlock",64	 ACPI_FADT_OFFSET(xpm1a_control_block),65	 ACPI_FADT_OFFSET(pm1a_control_block),66	 ACPI_FADT_OFFSET(pm1_control_length),67	 ACPI_PM1_REGISTER_WIDTH,68	 ACPI_FADT_REQUIRED},69 70	{"Pm1bControlBlock",71	 ACPI_FADT_OFFSET(xpm1b_control_block),72	 ACPI_FADT_OFFSET(pm1b_control_block),73	 ACPI_FADT_OFFSET(pm1_control_length),74	 ACPI_PM1_REGISTER_WIDTH,75	 ACPI_FADT_OPTIONAL},76 77	{"Pm2ControlBlock",78	 ACPI_FADT_OFFSET(xpm2_control_block),79	 ACPI_FADT_OFFSET(pm2_control_block),80	 ACPI_FADT_OFFSET(pm2_control_length),81	 ACPI_PM2_REGISTER_WIDTH,82	 ACPI_FADT_SEPARATE_LENGTH},83 84	{"PmTimerBlock",85	 ACPI_FADT_OFFSET(xpm_timer_block),86	 ACPI_FADT_OFFSET(pm_timer_block),87	 ACPI_FADT_OFFSET(pm_timer_length),88	 ACPI_PM_TIMER_WIDTH,89	 ACPI_FADT_SEPARATE_LENGTH},	/* ACPI 5.0A: Timer is optional */90 91	{"Gpe0Block",92	 ACPI_FADT_OFFSET(xgpe0_block),93	 ACPI_FADT_OFFSET(gpe0_block),94	 ACPI_FADT_OFFSET(gpe0_block_length),95	 0,96	 ACPI_FADT_SEPARATE_LENGTH | ACPI_FADT_GPE_REGISTER},97 98	{"Gpe1Block",99	 ACPI_FADT_OFFSET(xgpe1_block),100	 ACPI_FADT_OFFSET(gpe1_block),101	 ACPI_FADT_OFFSET(gpe1_block_length),102	 0,103	 ACPI_FADT_SEPARATE_LENGTH | ACPI_FADT_GPE_REGISTER}104};105 106#define ACPI_FADT_INFO_ENTRIES \107			(sizeof (fadt_info_table) / sizeof (struct acpi_fadt_info))108 109/* Table used to split Event Blocks into separate status/enable registers */110 111typedef struct acpi_fadt_pm_info {112	struct acpi_generic_address *target;113	u16 source;114	u8 register_num;115 116} acpi_fadt_pm_info;117 118static struct acpi_fadt_pm_info fadt_pm_info_table[] = {119	{&acpi_gbl_xpm1a_status,120	 ACPI_FADT_OFFSET(xpm1a_event_block),121	 0},122 123	{&acpi_gbl_xpm1a_enable,124	 ACPI_FADT_OFFSET(xpm1a_event_block),125	 1},126 127	{&acpi_gbl_xpm1b_status,128	 ACPI_FADT_OFFSET(xpm1b_event_block),129	 0},130 131	{&acpi_gbl_xpm1b_enable,132	 ACPI_FADT_OFFSET(xpm1b_event_block),133	 1}134};135 136#define ACPI_FADT_PM_INFO_ENTRIES \137			(sizeof (fadt_pm_info_table) / sizeof (struct acpi_fadt_pm_info))138 139/*******************************************************************************140 *141 * FUNCTION:    acpi_tb_init_generic_address142 *143 * PARAMETERS:  generic_address     - GAS struct to be initialized144 *              space_id            - ACPI Space ID for this register145 *              byte_width          - Width of this register146 *              address             - Address of the register147 *              register_name       - ASCII name of the ACPI register148 *149 * RETURN:      None150 *151 * DESCRIPTION: Initialize a Generic Address Structure (GAS)152 *              See the ACPI specification for a full description and153 *              definition of this structure.154 *155 ******************************************************************************/156 157static void158acpi_tb_init_generic_address(struct acpi_generic_address *generic_address,159			     u8 space_id,160			     u8 byte_width,161			     u64 address, const char *register_name, u8 flags)162{163	u8 bit_width;164 165	/*166	 * Bit width field in the GAS is only one byte long, 255 max.167	 * Check for bit_width overflow in GAS.168	 */169	bit_width = (u8)(byte_width * 8);170	if (byte_width > 31) {	/* (31*8)=248, (32*8)=256 */171		/*172		 * No error for GPE blocks, because we do not use the bit_width173		 * for GPEs, the legacy length (byte_width) is used instead to174		 * allow for a large number of GPEs.175		 */176		if (!(flags & ACPI_FADT_GPE_REGISTER)) {177			ACPI_ERROR((AE_INFO,178				    "%s - 32-bit FADT register is too long (%u bytes, %u bits) "179				    "to convert to GAS struct - 255 bits max, truncating",180				    register_name, byte_width,181				    (byte_width * 8)));182		}183 184		bit_width = 255;185	}186 187	/*188	 * The 64-bit Address field is non-aligned in the byte packed189	 * GAS struct.190	 */191	ACPI_MOVE_64_TO_64(&generic_address->address, &address);192 193	/* All other fields are byte-wide */194 195	generic_address->space_id = space_id;196	generic_address->bit_width = bit_width;197	generic_address->bit_offset = 0;198	generic_address->access_width = 0;	/* Access width ANY */199}200 201/*******************************************************************************202 *203 * FUNCTION:    acpi_tb_select_address204 *205 * PARAMETERS:  register_name       - ASCII name of the ACPI register206 *              address32           - 32-bit address of the register207 *              address64           - 64-bit address of the register208 *209 * RETURN:      The resolved 64-bit address210 *211 * DESCRIPTION: Select between 32-bit and 64-bit versions of addresses within212 *              the FADT. Used for the FACS and DSDT addresses.213 *214 * NOTES:215 *216 * Check for FACS and DSDT address mismatches. An address mismatch between217 * the 32-bit and 64-bit address fields (FIRMWARE_CTRL/X_FIRMWARE_CTRL and218 * DSDT/X_DSDT) could be a corrupted address field or it might indicate219 * the presence of two FACS or two DSDT tables.220 *221 * November 2013:222 * By default, as per the ACPICA specification, a valid 64-bit address is223 * used regardless of the value of the 32-bit address. However, this224 * behavior can be overridden via the acpi_gbl_use32_bit_fadt_addresses flag.225 *226 ******************************************************************************/227 228static u64229acpi_tb_select_address(char *register_name, u32 address32, u64 address64)230{231 232	if (!address64) {233 234		/* 64-bit address is zero, use 32-bit address */235 236		return ((u64)address32);237	}238 239	if (address32 && (address64 != (u64)address32)) {240 241		/* Address mismatch between 32-bit and 64-bit versions */242 243		ACPI_BIOS_WARNING((AE_INFO,244				   "32/64X %s address mismatch in FADT: "245				   "0x%8.8X/0x%8.8X%8.8X, using %u-bit address",246				   register_name, address32,247				   ACPI_FORMAT_UINT64(address64),248				   acpi_gbl_use32_bit_fadt_addresses ? 32 :249				   64));250 251		/* 32-bit address override */252 253		if (acpi_gbl_use32_bit_fadt_addresses) {254			return ((u64)address32);255		}256	}257 258	/* Default is to use the 64-bit address */259 260	return (address64);261}262 263/*******************************************************************************264 *265 * FUNCTION:    acpi_tb_parse_fadt266 *267 * PARAMETERS:  None268 *269 * RETURN:      None270 *271 * DESCRIPTION: Initialize the FADT, DSDT and FACS tables272 *              (FADT contains the addresses of the DSDT and FACS)273 *274 ******************************************************************************/275 276void acpi_tb_parse_fadt(void)277{278	u32 length;279	struct acpi_table_header *table;280	struct acpi_table_desc *fadt_desc;281	acpi_status status;282 283	/*284	 * The FADT has multiple versions with different lengths,285	 * and it contains pointers to both the DSDT and FACS tables.286	 *287	 * Get a local copy of the FADT and convert it to a common format288	 * Map entire FADT, assumed to be smaller than one page.289	 */290	fadt_desc = &acpi_gbl_root_table_list.tables[acpi_gbl_fadt_index];291	status = acpi_tb_get_table(fadt_desc, &table);292	if (ACPI_FAILURE(status)) {293		return;294	}295	length = fadt_desc->length;296 297	/*298	 * Validate the FADT checksum before we copy the table. Ignore299	 * checksum error as we want to try to get the DSDT and FACS.300	 */301	(void)acpi_ut_verify_checksum(table, length);302 303	/* Create a local copy of the FADT in common ACPI 2.0+ format */304 305	acpi_tb_create_local_fadt(table, length);306 307	/* All done with the real FADT, unmap it */308 309	acpi_tb_put_table(fadt_desc);310 311	/* Obtain the DSDT and FACS tables via their addresses within the FADT */312 313	acpi_tb_install_standard_table((acpi_physical_address)acpi_gbl_FADT.314				       Xdsdt,315				       ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,316				       NULL, FALSE, TRUE, &acpi_gbl_dsdt_index);317 318	if (acpi_gbl_FADT.facs) {319		acpi_tb_install_standard_table((acpi_physical_address)320					       acpi_gbl_FADT.facs,321					       ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,322					       NULL, FALSE, TRUE,323					       &acpi_gbl_facs_index);324	}325	if (acpi_gbl_FADT.Xfacs) {326		acpi_tb_install_standard_table((acpi_physical_address)327					       acpi_gbl_FADT.Xfacs,328					       ACPI_TABLE_ORIGIN_INTERNAL_PHYSICAL,329					       NULL, FALSE, TRUE,330					       &acpi_gbl_xfacs_index);331	}332}333 334/*******************************************************************************335 *336 * FUNCTION:    acpi_tb_create_local_fadt337 *338 * PARAMETERS:  table               - Pointer to BIOS FADT339 *              length              - Length of the table340 *341 * RETURN:      None342 *343 * DESCRIPTION: Get a local copy of the FADT and convert it to a common format.344 *              Performs validation on some important FADT fields.345 *346 * NOTE:        We create a local copy of the FADT regardless of the version.347 *348 ******************************************************************************/349 350void acpi_tb_create_local_fadt(struct acpi_table_header *table, u32 length)351{352	/*353	 * Check if the FADT is larger than the largest table that we expect354	 * (typically the current ACPI specification version). If so, truncate355	 * the table, and issue a warning.356	 */357	if (length > sizeof(struct acpi_table_fadt)) {358		ACPI_BIOS_WARNING((AE_INFO,359				   "FADT (revision %u) is longer than %s length, "360				   "truncating length %u to %u",361				   table->revision, ACPI_FADT_CONFORMANCE,362				   length,363				   (u32)sizeof(struct acpi_table_fadt)));364	}365 366	/* Clear the entire local FADT */367 368	memset(&acpi_gbl_FADT, 0, sizeof(struct acpi_table_fadt));369 370	/* Copy the original FADT, up to sizeof (struct acpi_table_fadt) */371 372	memcpy(&acpi_gbl_FADT, table,373	       ACPI_MIN(length, sizeof(struct acpi_table_fadt)));374 375	/* Take a copy of the Hardware Reduced flag */376 377	acpi_gbl_reduced_hardware = FALSE;378	if (acpi_gbl_FADT.flags & ACPI_FADT_HW_REDUCED) {379		acpi_gbl_reduced_hardware = TRUE;380	}381 382	/* Convert the local copy of the FADT to the common internal format */383 384	acpi_tb_convert_fadt();385 386	/* Initialize the global ACPI register structures */387 388	acpi_tb_setup_fadt_registers();389}390 391/*******************************************************************************392 *393 * FUNCTION:    acpi_tb_convert_fadt394 *395 * PARAMETERS:  none - acpi_gbl_FADT is used.396 *397 * RETURN:      None398 *399 * DESCRIPTION: Converts all versions of the FADT to a common internal format.400 *              Expand 32-bit addresses to 64-bit as necessary. Also validate401 *              important fields within the FADT.402 *403 * NOTE:        acpi_gbl_FADT must be of size (struct acpi_table_fadt), and must404 *              contain a copy of the actual BIOS-provided FADT.405 *406 * Notes on 64-bit register addresses:407 *408 * After this FADT conversion, later ACPICA code will only use the 64-bit "X"409 * fields of the FADT for all ACPI register addresses.410 *411 * The 64-bit X fields are optional extensions to the original 32-bit FADT412 * V1.0 fields. Even if they are present in the FADT, they are optional and413 * are unused if the BIOS sets them to zero. Therefore, we must copy/expand414 * 32-bit V1.0 fields to the 64-bit X fields if the 64-bit X field is originally415 * zero.416 *417 * For ACPI 1.0 FADTs (that contain no 64-bit addresses), all 32-bit address418 * fields are expanded to the corresponding 64-bit X fields in the internal419 * common FADT.420 *421 * For ACPI 2.0+ FADTs, all valid (non-zero) 32-bit address fields are expanded422 * to the corresponding 64-bit X fields, if the 64-bit field is originally423 * zero. Adhering to the ACPI specification, we completely ignore the 32-bit424 * field if the 64-bit field is valid, regardless of whether the host OS is425 * 32-bit or 64-bit.426 *427 * Possible additional checks:428 *  (acpi_gbl_FADT.pm1_event_length >= 4)429 *  (acpi_gbl_FADT.pm1_control_length >= 2)430 *  (acpi_gbl_FADT.pm_timer_length >= 4)431 *  Gpe block lengths must be multiple of 2432 *433 ******************************************************************************/434 435static void acpi_tb_convert_fadt(void)436{437	const char *name;438	struct acpi_generic_address *address64;439	u32 address32;440	u8 length;441	u8 flags;442	u32 i;443 444	/*445	 * For ACPI 1.0 FADTs (revision 1 or 2), ensure that reserved fields which446	 * should be zero are indeed zero. This will workaround BIOSs that447	 * inadvertently place values in these fields.448	 *449	 * The ACPI 1.0 reserved fields that will be zeroed are the bytes located450	 * at offset 45, 55, 95, and the word located at offset 109, 110.451	 *452	 * Note: The FADT revision value is unreliable. Only the length can be453	 * trusted.454	 */455	if (acpi_gbl_FADT.header.length <= ACPI_FADT_V2_SIZE) {456		acpi_gbl_FADT.preferred_profile = 0;457		acpi_gbl_FADT.pstate_control = 0;458		acpi_gbl_FADT.cst_control = 0;459		acpi_gbl_FADT.boot_flags = 0;460	}461 462	/*463	 * Now we can update the local FADT length to the length of the464	 * current FADT version as defined by the ACPI specification.465	 * Thus, we will have a common FADT internally.466	 */467	acpi_gbl_FADT.header.length = sizeof(struct acpi_table_fadt);468 469	/*470	 * Expand the 32-bit DSDT addresses to 64-bit as necessary.471	 * Later ACPICA code will always use the X 64-bit field.472	 */473	acpi_gbl_FADT.Xdsdt = acpi_tb_select_address("DSDT",474						     acpi_gbl_FADT.dsdt,475						     acpi_gbl_FADT.Xdsdt);476 477	/* If Hardware Reduced flag is set, we are all done */478 479	if (acpi_gbl_reduced_hardware) {480		return;481	}482 483	/* Examine all of the 64-bit extended address fields (X fields) */484 485	for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {486		/*487		 * Get the 32-bit and 64-bit addresses, as well as the register488		 * length and register name.489		 */490		address32 = *ACPI_ADD_PTR(u32,491					  &acpi_gbl_FADT,492					  fadt_info_table[i].address32);493 494		address64 = ACPI_ADD_PTR(struct acpi_generic_address,495					 &acpi_gbl_FADT,496					 fadt_info_table[i].address64);497 498		length = *ACPI_ADD_PTR(u8,499				       &acpi_gbl_FADT,500				       fadt_info_table[i].length);501 502		name = fadt_info_table[i].name;503		flags = fadt_info_table[i].flags;504 505		/*506		 * Expand the ACPI 1.0 32-bit addresses to the ACPI 2.0 64-bit "X"507		 * generic address structures as necessary. Later code will always use508		 * the 64-bit address structures.509		 *510		 * November 2013:511		 * Now always use the 64-bit address if it is valid (non-zero), in512		 * accordance with the ACPI specification which states that a 64-bit513		 * address supersedes the 32-bit version. This behavior can be514		 * overridden by the acpi_gbl_use32_bit_fadt_addresses flag.515		 *516		 * During 64-bit address construction and verification,517		 * these cases are handled:518		 *519		 * Address32 zero, Address64 [don't care]   - Use Address64520		 *521		 * No override: if acpi_gbl_use32_bit_fadt_addresses is FALSE, and:522		 * Address32 non-zero, Address64 zero       - Copy/use Address32523		 * Address32 non-zero == Address64 non-zero - Use Address64524		 * Address32 non-zero != Address64 non-zero - Warning, use Address64525		 *526		 * Override: if acpi_gbl_use32_bit_fadt_addresses is TRUE, and:527		 * Address32 non-zero, Address64 zero       - Copy/use Address32528		 * Address32 non-zero == Address64 non-zero - Copy/use Address32529		 * Address32 non-zero != Address64 non-zero - Warning, copy/use Address32530		 *531		 * Note: space_id is always I/O for 32-bit legacy address fields532		 */533		if (address32) {534			if (address64->address) {535				if (address64->address != (u64)address32) {536 537					/* Address mismatch */538 539					ACPI_BIOS_WARNING((AE_INFO,540							   "32/64X address mismatch in FADT/%s: "541							   "0x%8.8X/0x%8.8X%8.8X, using %u-bit address",542							   name, address32,543							   ACPI_FORMAT_UINT64544							   (address64->address),545							   acpi_gbl_use32_bit_fadt_addresses546							   ? 32 : 64));547				}548 549				/*550				 * For each extended field, check for length mismatch551				 * between the legacy length field and the corresponding552				 * 64-bit X length field.553				 * Note: If the legacy length field is > 0xFF bits, ignore554				 * this check. (GPE registers can be larger than the555				 * 64-bit GAS structure can accommodate, 0xFF bits).556				 */557				if ((ACPI_MUL_8(length) <= ACPI_UINT8_MAX) &&558				    (address64->bit_width !=559				     ACPI_MUL_8(length))) {560					ACPI_BIOS_WARNING((AE_INFO,561							   "32/64X length mismatch in FADT/%s: %u/%u",562							   name,563							   ACPI_MUL_8(length),564							   address64->565							   bit_width));566				}567			}568 569			/*570			 * Hardware register access code always uses the 64-bit fields.571			 * So if the 64-bit field is zero or is to be overridden,572			 * initialize it with the 32-bit fields.573			 * Note that when the 32-bit address favor is specified, the574			 * 64-bit fields are always re-initialized so that575			 * access_size/bit_width/bit_offset fields can be correctly576			 * configured to the values to trigger a 32-bit compatible577			 * access mode in the hardware register access code.578			 */579			if (!address64->address580			    || acpi_gbl_use32_bit_fadt_addresses) {581				acpi_tb_init_generic_address(address64,582							     ACPI_ADR_SPACE_SYSTEM_IO,583							     length,584							     (u64)address32,585							     name, flags);586			}587		}588 589		if (fadt_info_table[i].flags & ACPI_FADT_REQUIRED) {590			/*591			 * Field is required (Pm1a_event, Pm1a_control).592			 * Both the address and length must be non-zero.593			 */594			if (!address64->address || !length) {595				ACPI_BIOS_ERROR((AE_INFO,596						 "Required FADT field %s has zero address and/or length: "597						 "0x%8.8X%8.8X/0x%X",598						 name,599						 ACPI_FORMAT_UINT64(address64->600								    address),601						 length));602			}603		} else if (fadt_info_table[i].flags & ACPI_FADT_SEPARATE_LENGTH) {604			/*605			 * Field is optional (Pm2_control, GPE0, GPE1) AND has its own606			 * length field. If present, both the address and length must607			 * be valid.608			 */609			if ((address64->address && !length) ||610			    (!address64->address && length)) {611				ACPI_BIOS_WARNING((AE_INFO,612						   "Optional FADT field %s has valid %s but zero %s: "613						   "0x%8.8X%8.8X/0x%X", name,614						   (length ? "Length" :615						    "Address"),616						   (length ? "Address" :617						    "Length"),618						   ACPI_FORMAT_UINT64619						   (address64->address),620						   length));621			}622		}623	}624}625 626/*******************************************************************************627 *628 * FUNCTION:    acpi_tb_setup_fadt_registers629 *630 * PARAMETERS:  None, uses acpi_gbl_FADT.631 *632 * RETURN:      None633 *634 * DESCRIPTION: Initialize global ACPI PM1 register definitions. Optionally,635 *              force FADT register definitions to their default lengths.636 *637 ******************************************************************************/638 639static void acpi_tb_setup_fadt_registers(void)640{641	struct acpi_generic_address *target64;642	struct acpi_generic_address *source64;643	u8 pm1_register_byte_width;644	u32 i;645 646	/*647	 * Optionally check all register lengths against the default values and648	 * update them if they are incorrect.649	 */650	if (acpi_gbl_use_default_register_widths) {651		for (i = 0; i < ACPI_FADT_INFO_ENTRIES; i++) {652			target64 =653			    ACPI_ADD_PTR(struct acpi_generic_address,654					 &acpi_gbl_FADT,655					 fadt_info_table[i].address64);656 657			/*658			 * If a valid register (Address != 0) and the (default_length > 0)659			 * (Not a GPE register), then check the width against the default.660			 */661			if ((target64->address) &&662			    (fadt_info_table[i].default_length > 0) &&663			    (fadt_info_table[i].default_length !=664			     target64->bit_width)) {665				ACPI_BIOS_WARNING((AE_INFO,666						   "Invalid length for FADT/%s: %u, using default %u",667						   fadt_info_table[i].name,668						   target64->bit_width,669						   fadt_info_table[i].670						   default_length));671 672				/* Incorrect size, set width to the default */673 674				target64->bit_width =675				    fadt_info_table[i].default_length;676			}677		}678	}679 680	/*681	 * Get the length of the individual PM1 registers (enable and status).682	 * Each register is defined to be (event block length / 2). Extra divide683	 * by 8 converts bits to bytes.684	 */685	pm1_register_byte_width = (u8)686	    ACPI_DIV_16(acpi_gbl_FADT.xpm1a_event_block.bit_width);687 688	/*689	 * Calculate separate GAS structs for the PM1x (A/B) Status and Enable690	 * registers. These addresses do not appear (directly) in the FADT, so it691	 * is useful to pre-calculate them from the PM1 Event Block definitions.692	 *693	 * The PM event blocks are split into two register blocks, first is the694	 * PM Status Register block, followed immediately by the PM Enable695	 * Register block. Each is of length (pm1_event_length/2)696	 *697	 * Note: The PM1A event block is required by the ACPI specification.698	 * However, the PM1B event block is optional and is rarely, if ever,699	 * used.700	 */701 702	for (i = 0; i < ACPI_FADT_PM_INFO_ENTRIES; i++) {703		source64 =704		    ACPI_ADD_PTR(struct acpi_generic_address, &acpi_gbl_FADT,705				 fadt_pm_info_table[i].source);706 707		if (source64->address) {708			acpi_tb_init_generic_address(fadt_pm_info_table[i].709						     target, source64->space_id,710						     pm1_register_byte_width,711						     source64->address +712						     (fadt_pm_info_table[i].713						      register_num *714						      pm1_register_byte_width),715						     "PmRegisters", 0);716		}717	}718}719