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v5.4
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* -*- linux-c -*-
   3 * APM BIOS driver for Linux
   4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   5 *
   6 * Initial development of this driver was funded by NEC Australia P/L
   7 *	and NEC Corporation
   8 *
   9 * October 1995, Rik Faith (faith@cs.unc.edu):
  10 *    Minor enhancements and updates (to the patch set) for 1.3.x
  11 *    Documentation
  12 * January 1996, Rik Faith (faith@cs.unc.edu):
  13 *    Make /proc/apm easy to format (bump driver version)
  14 * March 1996, Rik Faith (faith@cs.unc.edu):
  15 *    Prohibit APM BIOS calls unless apm_enabled.
  16 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  18 *    Version 1.0 and 1.1
  19 * May 1996, Version 1.2
  20 * Feb 1998, Version 1.3
  21 * Feb 1998, Version 1.4
  22 * Aug 1998, Version 1.5
  23 * Sep 1998, Version 1.6
  24 * Nov 1998, Version 1.7
  25 * Jan 1999, Version 1.8
  26 * Jan 1999, Version 1.9
  27 * Oct 1999, Version 1.10
  28 * Nov 1999, Version 1.11
  29 * Jan 2000, Version 1.12
  30 * Feb 2000, Version 1.13
  31 * Nov 2000, Version 1.14
  32 * Oct 2001, Version 1.15
  33 * Jan 2002, Version 1.16
  34 * Oct 2002, Version 1.16ac
  35 *
  36 * History:
  37 *    0.6b: first version in official kernel, Linux 1.3.46
  38 *    0.7: changed /proc/apm format, Linux 1.3.58
  39 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  40 *    0.9: only call bios if bios is present, Linux 1.3.72
  41 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  42 *         Linux 1.3.85
  43 *    1.1: support user-space standby and suspend, power off after system
  44 *         halted, Linux 1.3.98
  45 *    1.2: When resetting RTC after resume, take care so that the time
  46 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  47 *         <jtoth@princeton.edu>); improve interaction between
  48 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  49 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  50 *	   levels to the printk calls. APM is not defined for SMP machines.
  51 *         The new replacement for it is, but Linux doesn't yet support this.
  52 *         Alan Cox Linux 2.1.55
  53 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  54 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  55 *         Dean Gaudet <dgaudet@arctic.org>.
  56 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  57 *    1.5: Fix segment register reloading (in case of bad segments saved
  58 *         across BIOS call).
  59 *         Stephen Rothwell
  60 *    1.6: Cope with compiler/assembler differences.
  61 *         Only try to turn off the first display device.
  62 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  63 *                   <echter@informatik.uni-rostock.de>
  64 *         Stephen Rothwell
  65 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  66 *         to reflect current state of APM BIOS.
  67 *         Chris Rankin <rankinc@bellsouth.net>
  68 *         Reset interrupt 0 timer to 100Hz after suspend
  69 *         Chad Miller <cmiller@surfsouth.com>
  70 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  71 *         Richard Gooch <rgooch@atnf.csiro.au>
  72 *         Allow boot time disabling of APM
  73 *         Make boot messages far less verbose by default
  74 *         Make asm safer
  75 *         Stephen Rothwell
  76 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  77 *         Richard Gooch <rgooch@atnf.csiro.au>
  78 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  79 *         remove dependency on CONFIG_PROC_FS
  80 *         Stephen Rothwell
  81 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  82 *         Try to cope with BIOS's that need to have all display
  83 *         devices blanked and not just the first one.
  84 *         Ross Paterson <ross@soi.city.ac.uk>
  85 *         Fix segment limit setting it has always been wrong as
  86 *         the segments needed to have byte granularity.
  87 *         Mark a few things __init.
  88 *         Add hack to allow power off of SMP systems by popular request.
  89 *         Use CONFIG_SMP instead of __SMP__
  90 *         Ignore BOUNCES for three seconds.
  91 *         Stephen Rothwell
  92 *   1.10: Fix for Thinkpad return code.
  93 *         Merge 2.2 and 2.3 drivers.
  94 *         Remove APM dependencies in arch/i386/kernel/process.c
  95 *         Remove APM dependencies in drivers/char/sysrq.c
  96 *         Reset time across standby.
  97 *         Allow more inititialisation on SMP.
  98 *         Remove CONFIG_APM_POWER_OFF and make it boot time
  99 *         configurable (default on).
 100 *         Make debug only a boot time parameter (remove APM_DEBUG).
 101 *         Try to blank all devices on any error.
 102 *   1.11: Remove APM dependencies in drivers/char/console.c
 103 *         Check nr_running to detect if we are idle (from
 104 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 105 *         Fix for bioses that don't zero the top part of the
 106 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 107 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 108 *         Real mode power off patch (Walter Hofmann
 109 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 110 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 111 *         the code away anyway (smp_num_cpus == 1 in UP)
 112 *         noted by Artur Skawina <skawina@geocities.com>.
 113 *         Make power off under SMP work again.
 114 *         Fix thinko with initial engaging of BIOS.
 115 *         Make sure power off only happens on CPU 0
 116 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 117 *         Do error notification to user mode if BIOS calls fail.
 118 *         Move entrypoint offset fix to ...boot/setup.S
 119 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 120 *         Remove smp-power-off. SMP users must now specify
 121 *         "apm=power-off" on the kernel command line. Suggested
 122 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 123 *         <alan@lxorguk.ukuu.org.uk>.
 124 *         Register the /proc/apm entry even on SMP so that
 125 *         scripts that check for it before doing power off
 126 *         work (Jim Avera <jima@hal.com>).
 127 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 128 *         <andy_henroid@yahoo.com>).
 129 *         Modularize the code.
 130 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 131 *         is now the way life works).
 132 *         Fix thinko in suspend() (wrong return).
 133 *         Notify drivers on critical suspend.
 134 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 135 *         modified by sfr).
 136 *         Disable interrupts while we are suspended (Andy Henroid
 137 *         <andy_henroid@yahoo.com> fixed by sfr).
 138 *         Make power off work on SMP again (Tony Hoyle
 139 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 140 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 141 *         interval is now configurable.
 142 *   1.14: Make connection version persist across module unload/load.
 143 *         Enable and engage power management earlier.
 144 *         Disengage power management on module unload.
 145 *         Changed to use the sysrq-register hack for registering the
 146 *         power off function called by magic sysrq based upon discussions
 147 *         in irc://irc.openprojects.net/#kernelnewbies
 148 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 149 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 150 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 151 *         Work around byte swap bug in one of the Vaio's BIOS's
 152 *         (Marc Boucher <marc@mbsi.ca>).
 153 *         Exposed the disable flag to dmi so that we can handle known
 154 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 155 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 156 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 157 *         If an APM idle fails log it and idle sensibly
 158 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 159 *         Don't expect replies from clients who open the device O_RDONLY.
 160 *         (Idea from Thomas Hood)
 161 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 162 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 163 *         Notify listeners of standby or suspend events before notifying
 164 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 165 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 166 *         Ignore first resume after we generate our own resume event
 167 *         after a suspend (Thomas Hood)
 168 *         Daemonize now gets rid of our controlling terminal (sfr).
 169 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 170 *         idle_threshold (sfr).
 171 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 172 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 173 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 174 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 175 *
 176 * APM 1.1 Reference:
 177 *
 178 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 179 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 180 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 181 *
 182 * [This document is available free from Intel by calling 800.628.8686 (fax
 183 * 916.356.6100) or 800.548.4725; or from
 184 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 185 * available from Microsoft by calling 206.882.8080.]
 186 *
 187 * APM 1.2 Reference:
 188 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 189 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 190 *
 191 * [This document is available from Microsoft at:
 192 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 193 */
 194
 195#define pr_fmt(fmt) "apm: " fmt
 196
 197#include <linux/module.h>
 198
 199#include <linux/poll.h>
 200#include <linux/types.h>
 201#include <linux/stddef.h>
 202#include <linux/timer.h>
 203#include <linux/fcntl.h>
 204#include <linux/slab.h>
 205#include <linux/stat.h>
 206#include <linux/proc_fs.h>
 207#include <linux/seq_file.h>
 208#include <linux/miscdevice.h>
 209#include <linux/apm_bios.h>
 210#include <linux/init.h>
 211#include <linux/time.h>
 212#include <linux/sched/signal.h>
 213#include <linux/sched/cputime.h>
 214#include <linux/pm.h>
 215#include <linux/capability.h>
 216#include <linux/device.h>
 217#include <linux/kernel.h>
 218#include <linux/freezer.h>
 219#include <linux/smp.h>
 220#include <linux/dmi.h>
 221#include <linux/suspend.h>
 222#include <linux/kthread.h>
 223#include <linux/jiffies.h>
 224#include <linux/acpi.h>
 225#include <linux/syscore_ops.h>
 226#include <linux/i8253.h>
 227#include <linux/cpuidle.h>
 228
 229#include <linux/uaccess.h>
 230#include <asm/desc.h>
 231#include <asm/olpc.h>
 232#include <asm/paravirt.h>
 233#include <asm/reboot.h>
 234#include <asm/nospec-branch.h>
 
 235
 236#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 237extern int (*console_blank_hook)(int);
 238#endif
 239
 240/*
 241 * The apm_bios device is one of the misc char devices.
 242 * This is its minor number.
 243 */
 244#define	APM_MINOR_DEV	134
 245
 246/*
 247 * Various options can be changed at boot time as follows:
 248 * (We allow underscores for compatibility with the modules code)
 249 *	apm=on/off			enable/disable APM
 250 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 251 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 252 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 253 *	    					powering off
 254 *	    [no-]debug			log some debugging messages
 255 *	    [no-]power[-_]off		power off on shutdown
 256 *	    [no-]smp			Use apm even on an SMP box
 257 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 258 *	    				bounces
 259 *          idle[-_]threshold=<n>       System idle percentage above which to
 260 *                                      make APM BIOS idle calls. Set it to
 261 *                                      100 to disable.
 262 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 263 *                                      which the idle percentage is
 264 *                                      calculated.
 265 */
 266
 267/* KNOWN PROBLEM MACHINES:
 268 *
 269 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 270 *                         [Confirmed by TI representative]
 271 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 272 *                    [Confirmed by BIOS disassembly]
 273 *                    [This may work now ...]
 274 * P: Toshiba 1950S: battery life information only gets updated after resume
 275 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 276 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 277 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 278 * 	Neale Banks <neale@lowendale.com.au> December 2000
 279 *
 280 * Legend: U = unusable with APM patches
 281 *         P = partially usable with APM patches
 282 */
 283
 284/*
 285 * Define as 1 to make the driver always call the APM BIOS busy
 286 * routine even if the clock was not reported as slowed by the
 287 * idle routine.  Otherwise, define as 0.
 288 */
 289#define ALWAYS_CALL_BUSY   1
 290
 291/*
 292 * Define to make the APM BIOS calls zero all data segment registers (so
 293 * that an incorrect BIOS implementation will cause a kernel panic if it
 294 * tries to write to arbitrary memory).
 295 */
 296#define APM_ZERO_SEGS
 297
 298#include <asm/apm.h>
 299
 300/*
 301 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 302 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 303 * David Chen <chen@ctpa04.mit.edu>
 304 */
 305#undef INIT_TIMER_AFTER_SUSPEND
 306
 307#ifdef INIT_TIMER_AFTER_SUSPEND
 308#include <linux/timex.h>
 309#include <asm/io.h>
 310#include <linux/delay.h>
 311#endif
 312
 313/*
 314 * Need to poll the APM BIOS every second
 315 */
 316#define APM_CHECK_TIMEOUT	(HZ)
 317
 318/*
 319 * Ignore suspend events for this amount of time after a resume
 320 */
 321#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 322
 323/*
 324 * Maximum number of events stored
 325 */
 326#define APM_MAX_EVENTS		20
 327
 328/*
 329 * The per-file APM data
 330 */
 331struct apm_user {
 332	int		magic;
 333	struct apm_user *next;
 334	unsigned int	suser: 1;
 335	unsigned int	writer: 1;
 336	unsigned int	reader: 1;
 337	unsigned int	suspend_wait: 1;
 338	int		suspend_result;
 339	int		suspends_pending;
 340	int		standbys_pending;
 341	int		suspends_read;
 342	int		standbys_read;
 343	int		event_head;
 344	int		event_tail;
 345	apm_event_t	events[APM_MAX_EVENTS];
 346};
 347
 348/*
 349 * The magic number in apm_user
 350 */
 351#define APM_BIOS_MAGIC		0x4101
 352
 353/*
 354 * idle percentage above which bios idle calls are done
 355 */
 356#ifdef CONFIG_APM_CPU_IDLE
 357#define DEFAULT_IDLE_THRESHOLD	95
 358#else
 359#define DEFAULT_IDLE_THRESHOLD	100
 360#endif
 361#define DEFAULT_IDLE_PERIOD	(100 / 3)
 362
 363static int apm_cpu_idle(struct cpuidle_device *dev,
 364			struct cpuidle_driver *drv, int index);
 365
 366static struct cpuidle_driver apm_idle_driver = {
 367	.name = "apm_idle",
 368	.owner = THIS_MODULE,
 369	.states = {
 370		{ /* entry 0 is for polling */ },
 371		{ /* entry 1 is for APM idle */
 372			.name = "APM",
 373			.desc = "APM idle",
 374			.exit_latency = 250,	/* WAG */
 375			.target_residency = 500,	/* WAG */
 376			.enter = &apm_cpu_idle
 377		},
 378	},
 379	.state_count = 2,
 380};
 381
 382static struct cpuidle_device apm_cpuidle_device;
 383
 384/*
 385 * Local variables
 386 */
 387__visible struct {
 388	unsigned long	offset;
 389	unsigned short	segment;
 390} apm_bios_entry;
 391static int clock_slowed;
 392static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 393static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 394static int suspends_pending;
 395static int standbys_pending;
 396static int ignore_sys_suspend;
 397static int ignore_normal_resume;
 398static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 399
 400static bool debug __read_mostly;
 401static bool smp __read_mostly;
 402static int apm_disabled = -1;
 403#ifdef CONFIG_SMP
 404static bool power_off;
 405#else
 406static bool power_off = 1;
 407#endif
 408static bool realmode_power_off;
 409#ifdef CONFIG_APM_ALLOW_INTS
 410static bool allow_ints = 1;
 411#else
 412static bool allow_ints;
 413#endif
 414static bool broken_psr;
 415
 416static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 417static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 418static struct apm_user *user_list;
 419static DEFINE_SPINLOCK(user_list_lock);
 420static DEFINE_MUTEX(apm_mutex);
 421
 422/*
 423 * Set up a segment that references the real mode segment 0x40
 424 * that extends up to the end of page zero (that we have reserved).
 425 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 426 * even though they are called in protected mode.
 427 */
 428static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
 429			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 430
 431static const char driver_version[] = "1.16ac";	/* no spaces */
 432
 433static struct task_struct *kapmd_task;
 434
 435/*
 436 *	APM event names taken from the APM 1.2 specification. These are
 437 *	the message codes that the BIOS uses to tell us about events
 438 */
 439static const char * const apm_event_name[] = {
 440	"system standby",
 441	"system suspend",
 442	"normal resume",
 443	"critical resume",
 444	"low battery",
 445	"power status change",
 446	"update time",
 447	"critical suspend",
 448	"user standby",
 449	"user suspend",
 450	"system standby resume",
 451	"capabilities change"
 452};
 453#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 454
 455typedef struct lookup_t {
 456	int	key;
 457	char 	*msg;
 458} lookup_t;
 459
 460/*
 461 *	The BIOS returns a set of standard error codes in AX when the
 462 *	carry flag is set.
 463 */
 464
 465static const lookup_t error_table[] = {
 466/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 467	{ APM_DISABLED,		"Power management disabled" },
 468	{ APM_CONNECTED,	"Real mode interface already connected" },
 469	{ APM_NOT_CONNECTED,	"Interface not connected" },
 470	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 471/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 472	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 473	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 474	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 475	{ APM_BAD_PARAM,	"Parameter out of range" },
 476	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 477	{ APM_BAD_FUNCTION,     "Function not supported" },
 478	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 479	{ APM_BAD_STATE,	"Unable to enter requested state" },
 480/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 481	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 482	{ APM_NOT_PRESENT,	"No APM present" }
 483};
 484#define ERROR_COUNT	ARRAY_SIZE(error_table)
 485
 486/**
 487 *	apm_error	-	display an APM error
 488 *	@str: information string
 489 *	@err: APM BIOS return code
 490 *
 491 *	Write a meaningful log entry to the kernel log in the event of
 492 *	an APM error.  Note that this also handles (negative) kernel errors.
 493 */
 494
 495static void apm_error(char *str, int err)
 496{
 497	int i;
 498
 499	for (i = 0; i < ERROR_COUNT; i++)
 500		if (error_table[i].key == err)
 501			break;
 502	if (i < ERROR_COUNT)
 503		pr_notice("%s: %s\n", str, error_table[i].msg);
 504	else if (err < 0)
 505		pr_notice("%s: linux error code %i\n", str, err);
 506	else
 507		pr_notice("%s: unknown error code %#2.2x\n",
 508		       str, err);
 509}
 510
 511/*
 512 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 513 * apm_info.allow_ints, we are being really paranoid here!  Not only
 514 * are interrupts disabled, but all the segment registers (except SS)
 515 * are saved and zeroed this means that if the BIOS tries to reference
 516 * any data without explicitly loading the segment registers, the kernel
 517 * will fault immediately rather than have some unforeseen circumstances
 518 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 519 * this depends on CS referring to the same physical memory as DS so that
 520 * DS can be zeroed before the call. Unfortunately, we can't do anything
 521 * about the stack segment/pointer.  Also, we tell the compiler that
 522 * everything could change.
 523 *
 524 * Also, we KNOW that for the non error case of apm_bios_call, there
 525 * is no useful data returned in the low order 8 bits of eax.
 526 */
 527
 528static inline unsigned long __apm_irq_save(void)
 529{
 530	unsigned long flags;
 531	local_save_flags(flags);
 532	if (apm_info.allow_ints) {
 533		if (irqs_disabled_flags(flags))
 534			local_irq_enable();
 535	} else
 536		local_irq_disable();
 537
 538	return flags;
 539}
 540
 541#define apm_irq_save(flags) \
 542	do { flags = __apm_irq_save(); } while (0)
 543
 544static inline void apm_irq_restore(unsigned long flags)
 545{
 546	if (irqs_disabled_flags(flags))
 547		local_irq_disable();
 548	else if (irqs_disabled())
 549		local_irq_enable();
 550}
 551
 552#ifdef APM_ZERO_SEGS
 553#	define APM_DECL_SEGS \
 554		unsigned int saved_fs; unsigned int saved_gs;
 555#	define APM_DO_SAVE_SEGS \
 556		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 557#	define APM_DO_RESTORE_SEGS \
 558		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 559#else
 560#	define APM_DECL_SEGS
 561#	define APM_DO_SAVE_SEGS
 562#	define APM_DO_RESTORE_SEGS
 563#endif
 564
 565struct apm_bios_call {
 566	u32 func;
 567	/* In and out */
 568	u32 ebx;
 569	u32 ecx;
 570	/* Out only */
 571	u32 eax;
 572	u32 edx;
 573	u32 esi;
 574
 575	/* Error: -ENOMEM, or bits 8-15 of eax */
 576	int err;
 577};
 578
 579/**
 580 *	__apm_bios_call - Make an APM BIOS 32bit call
 581 *	@_call: pointer to struct apm_bios_call.
 582 *
 583 *	Make an APM call using the 32bit protected mode interface. The
 584 *	caller is responsible for knowing if APM BIOS is configured and
 585 *	enabled. This call can disable interrupts for a long period of
 586 *	time on some laptops.  The return value is in AH and the carry
 587 *	flag is loaded into AL.  If there is an error, then the error
 588 *	code is returned in AH (bits 8-15 of eax) and this function
 589 *	returns non-zero.
 590 *
 591 *	Note: this makes the call on the current CPU.
 592 */
 593static long __apm_bios_call(void *_call)
 594{
 595	APM_DECL_SEGS
 596	unsigned long		flags;
 597	int			cpu;
 598	struct desc_struct	save_desc_40;
 599	struct desc_struct	*gdt;
 600	struct apm_bios_call	*call = _call;
 
 601
 602	cpu = get_cpu();
 603	BUG_ON(cpu != 0);
 604	gdt = get_cpu_gdt_rw(cpu);
 605	save_desc_40 = gdt[0x40 / 8];
 606	gdt[0x40 / 8] = bad_bios_desc;
 607
 608	apm_irq_save(flags);
 609	firmware_restrict_branch_speculation_start();
 
 610	APM_DO_SAVE_SEGS;
 611	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 612			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 613			  &call->esi);
 614	APM_DO_RESTORE_SEGS;
 
 615	firmware_restrict_branch_speculation_end();
 616	apm_irq_restore(flags);
 617	gdt[0x40 / 8] = save_desc_40;
 618	put_cpu();
 619
 620	return call->eax & 0xff;
 621}
 622
 623/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 624static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 625{
 626	int ret;
 627
 628	/* Don't bother with work_on_cpu in the common case, so we don't
 629	 * have to worry about OOM or overhead. */
 630	if (get_cpu() == 0) {
 631		ret = fn(call);
 632		put_cpu();
 633	} else {
 634		put_cpu();
 635		ret = work_on_cpu(0, fn, call);
 636	}
 637
 638	/* work_on_cpu can fail with -ENOMEM */
 639	if (ret < 0)
 640		call->err = ret;
 641	else
 642		call->err = (call->eax >> 8) & 0xff;
 643
 644	return ret;
 645}
 646
 647/**
 648 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 649 *	@call: the apm_bios_call registers.
 650 *
 651 *	If there is an error, it is returned in @call.err.
 652 */
 653static int apm_bios_call(struct apm_bios_call *call)
 654{
 655	return on_cpu0(__apm_bios_call, call);
 656}
 657
 658/**
 659 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 660 *	@_call: pointer to struct apm_bios_call.
 661 *
 662 *	Make a BIOS call that returns one value only, or just status.
 663 *	If there is an error, then the error code is returned in AH
 664 *	(bits 8-15 of eax) and this function returns non-zero (it can
 665 *	also return -ENOMEM). This is used for simpler BIOS operations.
 666 *	This call may hold interrupts off for a long time on some laptops.
 667 *
 668 *	Note: this makes the call on the current CPU.
 669 */
 670static long __apm_bios_call_simple(void *_call)
 671{
 672	u8			error;
 673	APM_DECL_SEGS
 674	unsigned long		flags;
 675	int			cpu;
 676	struct desc_struct	save_desc_40;
 677	struct desc_struct	*gdt;
 678	struct apm_bios_call	*call = _call;
 
 679
 680	cpu = get_cpu();
 681	BUG_ON(cpu != 0);
 682	gdt = get_cpu_gdt_rw(cpu);
 683	save_desc_40 = gdt[0x40 / 8];
 684	gdt[0x40 / 8] = bad_bios_desc;
 685
 686	apm_irq_save(flags);
 687	firmware_restrict_branch_speculation_start();
 
 688	APM_DO_SAVE_SEGS;
 689	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 690					 &call->eax);
 691	APM_DO_RESTORE_SEGS;
 
 692	firmware_restrict_branch_speculation_end();
 693	apm_irq_restore(flags);
 694	gdt[0x40 / 8] = save_desc_40;
 695	put_cpu();
 696	return error;
 697}
 698
 699/**
 700 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 701 *	@func: APM function to invoke
 702 *	@ebx_in: EBX register value for BIOS call
 703 *	@ecx_in: ECX register value for BIOS call
 704 *	@eax: EAX register on return from the BIOS call
 705 *	@err: bits
 706 *
 707 *	Make a BIOS call that returns one value only, or just status.
 708 *	If there is an error, then the error code is returned in @err
 709 *	and this function returns non-zero. This is used for simpler
 710 *	BIOS operations.  This call may hold interrupts off for a long
 711 *	time on some laptops.
 712 */
 713static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 714				int *err)
 715{
 716	struct apm_bios_call call;
 717	int ret;
 718
 719	call.func = func;
 720	call.ebx = ebx_in;
 721	call.ecx = ecx_in;
 722
 723	ret = on_cpu0(__apm_bios_call_simple, &call);
 724	*eax = call.eax;
 725	*err = call.err;
 726	return ret;
 727}
 728
 729/**
 730 *	apm_driver_version	-	APM driver version
 731 *	@val:	loaded with the APM version on return
 732 *
 733 *	Retrieve the APM version supported by the BIOS. This is only
 734 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 735 *	probably present.
 736 *
 737 *	On entry val should point to a value indicating the APM driver
 738 *	version with the high byte being the major and the low byte the
 739 *	minor number both in BCD
 740 *
 741 *	On return it will hold the BIOS revision supported in the
 742 *	same format.
 743 */
 744
 745static int apm_driver_version(u_short *val)
 746{
 747	u32 eax;
 748	int err;
 749
 750	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 751		return err;
 752	*val = eax;
 753	return APM_SUCCESS;
 754}
 755
 756/**
 757 *	apm_get_event	-	get an APM event from the BIOS
 758 *	@event: pointer to the event
 759 *	@info: point to the event information
 760 *
 761 *	The APM BIOS provides a polled information for event
 762 *	reporting. The BIOS expects to be polled at least every second
 763 *	when events are pending. When a message is found the caller should
 764 *	poll until no more messages are present.  However, this causes
 765 *	problems on some laptops where a suspend event notification is
 766 *	not cleared until it is acknowledged.
 767 *
 768 *	Additional information is returned in the info pointer, providing
 769 *	that APM 1.2 is in use. If no messges are pending the value 0x80
 770 *	is returned (No power management events pending).
 771 */
 772static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 773{
 774	struct apm_bios_call call;
 775
 776	call.func = APM_FUNC_GET_EVENT;
 777	call.ebx = call.ecx = 0;
 778
 779	if (apm_bios_call(&call))
 780		return call.err;
 781
 782	*event = call.ebx;
 783	if (apm_info.connection_version < 0x0102)
 784		*info = ~0; /* indicate info not valid */
 785	else
 786		*info = call.ecx;
 787	return APM_SUCCESS;
 788}
 789
 790/**
 791 *	set_power_state	-	set the power management state
 792 *	@what: which items to transition
 793 *	@state: state to transition to
 794 *
 795 *	Request an APM change of state for one or more system devices. The
 796 *	processor state must be transitioned last of all. what holds the
 797 *	class of device in the upper byte and the device number (0xFF for
 798 *	all) for the object to be transitioned.
 799 *
 800 *	The state holds the state to transition to, which may in fact
 801 *	be an acceptance of a BIOS requested state change.
 802 */
 803
 804static int set_power_state(u_short what, u_short state)
 805{
 806	u32 eax;
 807	int err;
 808
 809	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 810		return err;
 811	return APM_SUCCESS;
 812}
 813
 814/**
 815 *	set_system_power_state - set system wide power state
 816 *	@state: which state to enter
 817 *
 818 *	Transition the entire system into a new APM power state.
 819 */
 820
 821static int set_system_power_state(u_short state)
 822{
 823	return set_power_state(APM_DEVICE_ALL, state);
 824}
 825
 826/**
 827 *	apm_do_idle	-	perform power saving
 828 *
 829 *	This function notifies the BIOS that the processor is (in the view
 830 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 831 *	to handle the idle request. On a success the function returns 1
 832 *	if the BIOS did clock slowing or 0 otherwise.
 833 */
 834
 835static int apm_do_idle(void)
 836{
 837	u32 eax;
 838	u8 ret = 0;
 839	int idled = 0;
 840	int err = 0;
 841
 842	if (!need_resched()) {
 843		idled = 1;
 844		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 845	}
 846
 847	if (!idled)
 848		return 0;
 849
 850	if (ret) {
 851		static unsigned long t;
 852
 853		/* This always fails on some SMP boards running UP kernels.
 854		 * Only report the failure the first 5 times.
 855		 */
 856		if (++t < 5) {
 857			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 858			t = jiffies;
 859		}
 860		return -1;
 861	}
 862	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 863	return clock_slowed;
 864}
 865
 866/**
 867 *	apm_do_busy	-	inform the BIOS the CPU is busy
 868 *
 869 *	Request that the BIOS brings the CPU back to full performance.
 870 */
 871
 872static void apm_do_busy(void)
 873{
 874	u32 dummy;
 875	int err;
 876
 877	if (clock_slowed || ALWAYS_CALL_BUSY) {
 878		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 879		clock_slowed = 0;
 880	}
 881}
 882
 883/*
 884 * If no process has really been interested in
 885 * the CPU for some time, we want to call BIOS
 886 * power management - we probably want
 887 * to conserve power.
 888 */
 889#define IDLE_CALC_LIMIT	(HZ * 100)
 890#define IDLE_LEAKY_MAX	16
 891
 892/**
 893 * apm_cpu_idle		-	cpu idling for APM capable Linux
 894 *
 895 * This is the idling function the kernel executes when APM is available. It
 896 * tries to do BIOS powermanagement based on the average system idle time.
 897 * Furthermore it calls the system default idle routine.
 898 */
 899
 900static int apm_cpu_idle(struct cpuidle_device *dev,
 901	struct cpuidle_driver *drv, int index)
 902{
 903	static int use_apm_idle; /* = 0 */
 904	static unsigned int last_jiffies; /* = 0 */
 905	static u64 last_stime; /* = 0 */
 906	u64 stime, utime;
 907
 908	int apm_idle_done = 0;
 909	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 910	unsigned int bucket;
 911
 912recalc:
 913	task_cputime(current, &utime, &stime);
 914	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 915		use_apm_idle = 0;
 916	} else if (jiffies_since_last_check > idle_period) {
 917		unsigned int idle_percentage;
 918
 919		idle_percentage = nsecs_to_jiffies(stime - last_stime);
 920		idle_percentage *= 100;
 921		idle_percentage /= jiffies_since_last_check;
 922		use_apm_idle = (idle_percentage > idle_threshold);
 923		if (apm_info.forbid_idle)
 924			use_apm_idle = 0;
 925	}
 926
 927	last_jiffies = jiffies;
 928	last_stime = stime;
 929
 930	bucket = IDLE_LEAKY_MAX;
 931
 932	while (!need_resched()) {
 933		if (use_apm_idle) {
 934			unsigned int t;
 935
 936			t = jiffies;
 937			switch (apm_do_idle()) {
 938			case 0:
 939				apm_idle_done = 1;
 940				if (t != jiffies) {
 941					if (bucket) {
 942						bucket = IDLE_LEAKY_MAX;
 943						continue;
 944					}
 945				} else if (bucket) {
 946					bucket--;
 947					continue;
 948				}
 949				break;
 950			case 1:
 951				apm_idle_done = 1;
 952				break;
 953			default: /* BIOS refused */
 954				break;
 955			}
 956		}
 957		default_idle();
 958		local_irq_disable();
 959		jiffies_since_last_check = jiffies - last_jiffies;
 960		if (jiffies_since_last_check > idle_period)
 961			goto recalc;
 962	}
 963
 964	if (apm_idle_done)
 965		apm_do_busy();
 966
 967	return index;
 968}
 969
 970/**
 971 *	apm_power_off	-	ask the BIOS to power off
 972 *
 973 *	Handle the power off sequence. This is the one piece of code we
 974 *	will execute even on SMP machines. In order to deal with BIOS
 975 *	bugs we support real mode APM BIOS power off calls. We also make
 976 *	the SMP call on CPU0 as some systems will only honour this call
 977 *	on their first cpu.
 978 */
 979
 980static void apm_power_off(void)
 981{
 982	/* Some bioses don't like being called from CPU != 0 */
 983	if (apm_info.realmode_power_off) {
 984		set_cpus_allowed_ptr(current, cpumask_of(0));
 985		machine_real_restart(MRR_APM);
 986	} else {
 987		(void)set_system_power_state(APM_STATE_OFF);
 988	}
 989}
 990
 991#ifdef CONFIG_APM_DO_ENABLE
 992
 993/**
 994 *	apm_enable_power_management - enable BIOS APM power management
 995 *	@enable: enable yes/no
 996 *
 997 *	Enable or disable the APM BIOS power services.
 998 */
 999
1000static int apm_enable_power_management(int enable)
1001{
1002	u32 eax;
1003	int err;
1004
1005	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1006		return APM_NOT_ENGAGED;
1007	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1008				 enable, &eax, &err))
1009		return err;
1010	if (enable)
1011		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1012	else
1013		apm_info.bios.flags |= APM_BIOS_DISABLED;
1014	return APM_SUCCESS;
1015}
1016#endif
1017
1018/**
1019 *	apm_get_power_status	-	get current power state
1020 *	@status: returned status
1021 *	@bat: battery info
1022 *	@life: estimated life
1023 *
1024 *	Obtain the current power status from the APM BIOS. We return a
1025 *	status which gives the rough battery status, and current power
1026 *	source. The bat value returned give an estimate as a percentage
1027 *	of life and a status value for the battery. The estimated life
1028 *	if reported is a lifetime in secodnds/minutes at current powwer
1029 *	consumption.
1030 */
1031
1032static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1033{
1034	struct apm_bios_call call;
1035
1036	call.func = APM_FUNC_GET_STATUS;
1037	call.ebx = APM_DEVICE_ALL;
1038	call.ecx = 0;
1039
1040	if (apm_info.get_power_status_broken)
1041		return APM_32_UNSUPPORTED;
1042	if (apm_bios_call(&call)) {
1043		if (!call.err)
1044			return APM_NO_ERROR;
1045		return call.err;
1046	}
1047	*status = call.ebx;
1048	*bat = call.ecx;
1049	if (apm_info.get_power_status_swabinminutes) {
1050		*life = swab16((u16)call.edx);
1051		*life |= 0x8000;
1052	} else
1053		*life = call.edx;
1054	return APM_SUCCESS;
1055}
1056
1057#if 0
1058static int apm_get_battery_status(u_short which, u_short *status,
1059				  u_short *bat, u_short *life, u_short *nbat)
1060{
1061	u32 eax;
1062	u32 ebx;
1063	u32 ecx;
1064	u32 edx;
1065	u32 esi;
1066
1067	if (apm_info.connection_version < 0x0102) {
1068		/* pretend we only have one battery. */
1069		if (which != 1)
1070			return APM_BAD_DEVICE;
1071		*nbat = 1;
1072		return apm_get_power_status(status, bat, life);
1073	}
1074
1075	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1076			  &ebx, &ecx, &edx, &esi))
1077		return (eax >> 8) & 0xff;
1078	*status = ebx;
1079	*bat = ecx;
1080	*life = edx;
1081	*nbat = esi;
1082	return APM_SUCCESS;
1083}
1084#endif
1085
1086/**
1087 *	apm_engage_power_management	-	enable PM on a device
1088 *	@device: identity of device
1089 *	@enable: on/off
1090 *
1091 *	Activate or deactivate power management on either a specific device
1092 *	or the entire system (%APM_DEVICE_ALL).
1093 */
1094
1095static int apm_engage_power_management(u_short device, int enable)
1096{
1097	u32 eax;
1098	int err;
1099
1100	if ((enable == 0) && (device == APM_DEVICE_ALL)
1101	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1102		return APM_DISABLED;
1103	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1104				 &eax, &err))
1105		return err;
1106	if (device == APM_DEVICE_ALL) {
1107		if (enable)
1108			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1109		else
1110			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1111	}
1112	return APM_SUCCESS;
1113}
1114
1115#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1116
1117/**
1118 *	apm_console_blank	-	blank the display
1119 *	@blank: on/off
1120 *
1121 *	Attempt to blank the console, firstly by blanking just video device
1122 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1123 *	all video devices. Typically the BIOS will do laptop backlight and
1124 *	monitor powerdown for us.
1125 */
1126
1127static int apm_console_blank(int blank)
1128{
1129	int error = APM_NOT_ENGAGED; /* silence gcc */
1130	int i;
1131	u_short state;
1132	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1133
1134	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1135
1136	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1137		error = set_power_state(dev[i], state);
1138
1139		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1140			return 1;
1141
1142		if (error == APM_NOT_ENGAGED)
1143			break;
1144	}
1145
1146	if (error == APM_NOT_ENGAGED) {
1147		static int tried;
1148		int eng_error;
1149		if (tried++ == 0) {
1150			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1151			if (eng_error) {
1152				apm_error("set display", error);
1153				apm_error("engage interface", eng_error);
1154				return 0;
1155			} else
1156				return apm_console_blank(blank);
1157		}
1158	}
1159	apm_error("set display", error);
1160	return 0;
1161}
1162#endif
1163
1164static int queue_empty(struct apm_user *as)
1165{
1166	return as->event_head == as->event_tail;
1167}
1168
1169static apm_event_t get_queued_event(struct apm_user *as)
1170{
1171	if (++as->event_tail >= APM_MAX_EVENTS)
1172		as->event_tail = 0;
1173	return as->events[as->event_tail];
1174}
1175
1176static void queue_event(apm_event_t event, struct apm_user *sender)
1177{
1178	struct apm_user *as;
1179
1180	spin_lock(&user_list_lock);
1181	if (user_list == NULL)
1182		goto out;
1183	for (as = user_list; as != NULL; as = as->next) {
1184		if ((as == sender) || (!as->reader))
1185			continue;
1186		if (++as->event_head >= APM_MAX_EVENTS)
1187			as->event_head = 0;
1188
1189		if (as->event_head == as->event_tail) {
1190			static int notified;
1191
1192			if (notified++ == 0)
1193				pr_err("an event queue overflowed\n");
1194			if (++as->event_tail >= APM_MAX_EVENTS)
1195				as->event_tail = 0;
1196		}
1197		as->events[as->event_head] = event;
1198		if (!as->suser || !as->writer)
1199			continue;
1200		switch (event) {
1201		case APM_SYS_SUSPEND:
1202		case APM_USER_SUSPEND:
1203			as->suspends_pending++;
1204			suspends_pending++;
1205			break;
1206
1207		case APM_SYS_STANDBY:
1208		case APM_USER_STANDBY:
1209			as->standbys_pending++;
1210			standbys_pending++;
1211			break;
1212		}
1213	}
1214	wake_up_interruptible(&apm_waitqueue);
1215out:
1216	spin_unlock(&user_list_lock);
1217}
1218
1219static void reinit_timer(void)
1220{
1221#ifdef INIT_TIMER_AFTER_SUSPEND
1222	unsigned long flags;
1223
1224	raw_spin_lock_irqsave(&i8253_lock, flags);
1225	/* set the clock to HZ */
1226	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1227	udelay(10);
1228	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1229	udelay(10);
1230	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1231	udelay(10);
1232	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1233#endif
1234}
1235
1236static int suspend(int vetoable)
1237{
1238	int err;
1239	struct apm_user	*as;
1240
1241	dpm_suspend_start(PMSG_SUSPEND);
1242	dpm_suspend_end(PMSG_SUSPEND);
1243
1244	local_irq_disable();
1245	syscore_suspend();
1246
1247	local_irq_enable();
1248
1249	save_processor_state();
1250	err = set_system_power_state(APM_STATE_SUSPEND);
1251	ignore_normal_resume = 1;
1252	restore_processor_state();
1253
1254	local_irq_disable();
1255	reinit_timer();
1256
1257	if (err == APM_NO_ERROR)
1258		err = APM_SUCCESS;
1259	if (err != APM_SUCCESS)
1260		apm_error("suspend", err);
1261	err = (err == APM_SUCCESS) ? 0 : -EIO;
1262
1263	syscore_resume();
1264	local_irq_enable();
1265
1266	dpm_resume_start(PMSG_RESUME);
1267	dpm_resume_end(PMSG_RESUME);
1268
1269	queue_event(APM_NORMAL_RESUME, NULL);
1270	spin_lock(&user_list_lock);
1271	for (as = user_list; as != NULL; as = as->next) {
1272		as->suspend_wait = 0;
1273		as->suspend_result = err;
1274	}
1275	spin_unlock(&user_list_lock);
1276	wake_up_interruptible(&apm_suspend_waitqueue);
1277	return err;
1278}
1279
1280static void standby(void)
1281{
1282	int err;
1283
1284	dpm_suspend_end(PMSG_SUSPEND);
1285
1286	local_irq_disable();
1287	syscore_suspend();
1288	local_irq_enable();
1289
1290	err = set_system_power_state(APM_STATE_STANDBY);
1291	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1292		apm_error("standby", err);
1293
1294	local_irq_disable();
1295	syscore_resume();
1296	local_irq_enable();
1297
1298	dpm_resume_start(PMSG_RESUME);
1299}
1300
1301static apm_event_t get_event(void)
1302{
1303	int error;
1304	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1305	apm_eventinfo_t	info;
1306
1307	static int notified;
1308
1309	/* we don't use the eventinfo */
1310	error = apm_get_event(&event, &info);
1311	if (error == APM_SUCCESS)
1312		return event;
1313
1314	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1315		apm_error("get_event", error);
1316
1317	return 0;
1318}
1319
1320static void check_events(void)
1321{
1322	apm_event_t event;
1323	static unsigned long last_resume;
1324	static int ignore_bounce;
1325
1326	while ((event = get_event()) != 0) {
1327		if (debug) {
1328			if (event <= NR_APM_EVENT_NAME)
1329				printk(KERN_DEBUG "apm: received %s notify\n",
1330				       apm_event_name[event - 1]);
1331			else
1332				printk(KERN_DEBUG "apm: received unknown "
1333				       "event 0x%02x\n", event);
1334		}
1335		if (ignore_bounce
1336		    && (time_after(jiffies, last_resume + bounce_interval)))
1337			ignore_bounce = 0;
1338
1339		switch (event) {
1340		case APM_SYS_STANDBY:
1341		case APM_USER_STANDBY:
1342			queue_event(event, NULL);
1343			if (standbys_pending <= 0)
1344				standby();
1345			break;
1346
1347		case APM_USER_SUSPEND:
1348#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1349			if (apm_info.connection_version > 0x100)
1350				set_system_power_state(APM_STATE_REJECT);
1351			break;
1352#endif
1353		case APM_SYS_SUSPEND:
1354			if (ignore_bounce) {
1355				if (apm_info.connection_version > 0x100)
1356					set_system_power_state(APM_STATE_REJECT);
1357				break;
1358			}
1359			/*
1360			 * If we are already processing a SUSPEND,
1361			 * then further SUSPEND events from the BIOS
1362			 * will be ignored.  We also return here to
1363			 * cope with the fact that the Thinkpads keep
1364			 * sending a SUSPEND event until something else
1365			 * happens!
1366			 */
1367			if (ignore_sys_suspend)
1368				return;
1369			ignore_sys_suspend = 1;
1370			queue_event(event, NULL);
1371			if (suspends_pending <= 0)
1372				(void) suspend(1);
1373			break;
1374
1375		case APM_NORMAL_RESUME:
1376		case APM_CRITICAL_RESUME:
1377		case APM_STANDBY_RESUME:
1378			ignore_sys_suspend = 0;
1379			last_resume = jiffies;
1380			ignore_bounce = 1;
1381			if ((event != APM_NORMAL_RESUME)
1382			    || (ignore_normal_resume == 0)) {
1383				dpm_resume_end(PMSG_RESUME);
1384				queue_event(event, NULL);
1385			}
1386			ignore_normal_resume = 0;
1387			break;
1388
1389		case APM_CAPABILITY_CHANGE:
1390		case APM_LOW_BATTERY:
1391		case APM_POWER_STATUS_CHANGE:
1392			queue_event(event, NULL);
1393			/* If needed, notify drivers here */
1394			break;
1395
1396		case APM_UPDATE_TIME:
1397			break;
1398
1399		case APM_CRITICAL_SUSPEND:
1400			/*
1401			 * We are not allowed to reject a critical suspend.
1402			 */
1403			(void)suspend(0);
1404			break;
1405		}
1406	}
1407}
1408
1409static void apm_event_handler(void)
1410{
1411	static int pending_count = 4;
1412	int err;
1413
1414	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1415		if ((apm_info.connection_version > 0x100) &&
1416		    (pending_count-- <= 0)) {
1417			pending_count = 4;
1418			if (debug)
1419				printk(KERN_DEBUG "apm: setting state busy\n");
1420			err = set_system_power_state(APM_STATE_BUSY);
1421			if (err)
1422				apm_error("busy", err);
1423		}
1424	} else
1425		pending_count = 4;
1426	check_events();
1427}
1428
1429/*
1430 * This is the APM thread main loop.
1431 */
1432
1433static void apm_mainloop(void)
1434{
1435	DECLARE_WAITQUEUE(wait, current);
1436
1437	add_wait_queue(&apm_waitqueue, &wait);
1438	set_current_state(TASK_INTERRUPTIBLE);
1439	for (;;) {
1440		schedule_timeout(APM_CHECK_TIMEOUT);
1441		if (kthread_should_stop())
1442			break;
1443		/*
1444		 * Ok, check all events, check for idle (and mark us sleeping
1445		 * so as not to count towards the load average)..
1446		 */
1447		set_current_state(TASK_INTERRUPTIBLE);
1448		apm_event_handler();
1449	}
1450	remove_wait_queue(&apm_waitqueue, &wait);
1451}
1452
1453static int check_apm_user(struct apm_user *as, const char *func)
1454{
1455	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1456		pr_err("%s passed bad filp\n", func);
1457		return 1;
1458	}
1459	return 0;
1460}
1461
1462static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1463{
1464	struct apm_user *as;
1465	int i;
1466	apm_event_t event;
1467
1468	as = fp->private_data;
1469	if (check_apm_user(as, "read"))
1470		return -EIO;
1471	if ((int)count < sizeof(apm_event_t))
1472		return -EINVAL;
1473	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1474		return -EAGAIN;
1475	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1476	i = count;
1477	while ((i >= sizeof(event)) && !queue_empty(as)) {
1478		event = get_queued_event(as);
1479		if (copy_to_user(buf, &event, sizeof(event))) {
1480			if (i < count)
1481				break;
1482			return -EFAULT;
1483		}
1484		switch (event) {
1485		case APM_SYS_SUSPEND:
1486		case APM_USER_SUSPEND:
1487			as->suspends_read++;
1488			break;
1489
1490		case APM_SYS_STANDBY:
1491		case APM_USER_STANDBY:
1492			as->standbys_read++;
1493			break;
1494		}
1495		buf += sizeof(event);
1496		i -= sizeof(event);
1497	}
1498	if (i < count)
1499		return count - i;
1500	if (signal_pending(current))
1501		return -ERESTARTSYS;
1502	return 0;
1503}
1504
1505static __poll_t do_poll(struct file *fp, poll_table *wait)
1506{
1507	struct apm_user *as;
1508
1509	as = fp->private_data;
1510	if (check_apm_user(as, "poll"))
1511		return 0;
1512	poll_wait(fp, &apm_waitqueue, wait);
1513	if (!queue_empty(as))
1514		return EPOLLIN | EPOLLRDNORM;
1515	return 0;
1516}
1517
1518static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1519{
1520	struct apm_user *as;
1521	int ret;
1522
1523	as = filp->private_data;
1524	if (check_apm_user(as, "ioctl"))
1525		return -EIO;
1526	if (!as->suser || !as->writer)
1527		return -EPERM;
1528	switch (cmd) {
1529	case APM_IOC_STANDBY:
1530		mutex_lock(&apm_mutex);
1531		if (as->standbys_read > 0) {
1532			as->standbys_read--;
1533			as->standbys_pending--;
1534			standbys_pending--;
1535		} else
1536			queue_event(APM_USER_STANDBY, as);
1537		if (standbys_pending <= 0)
1538			standby();
1539		mutex_unlock(&apm_mutex);
1540		break;
1541	case APM_IOC_SUSPEND:
1542		mutex_lock(&apm_mutex);
1543		if (as->suspends_read > 0) {
1544			as->suspends_read--;
1545			as->suspends_pending--;
1546			suspends_pending--;
1547		} else
1548			queue_event(APM_USER_SUSPEND, as);
1549		if (suspends_pending <= 0) {
1550			ret = suspend(1);
1551			mutex_unlock(&apm_mutex);
1552		} else {
1553			as->suspend_wait = 1;
1554			mutex_unlock(&apm_mutex);
1555			wait_event_interruptible(apm_suspend_waitqueue,
1556					as->suspend_wait == 0);
1557			ret = as->suspend_result;
1558		}
1559		return ret;
1560	default:
1561		return -ENOTTY;
1562	}
1563	return 0;
1564}
1565
1566static int do_release(struct inode *inode, struct file *filp)
1567{
1568	struct apm_user *as;
1569
1570	as = filp->private_data;
1571	if (check_apm_user(as, "release"))
1572		return 0;
1573	filp->private_data = NULL;
1574	if (as->standbys_pending > 0) {
1575		standbys_pending -= as->standbys_pending;
1576		if (standbys_pending <= 0)
1577			standby();
1578	}
1579	if (as->suspends_pending > 0) {
1580		suspends_pending -= as->suspends_pending;
1581		if (suspends_pending <= 0)
1582			(void) suspend(1);
1583	}
1584	spin_lock(&user_list_lock);
1585	if (user_list == as)
1586		user_list = as->next;
1587	else {
1588		struct apm_user *as1;
1589
1590		for (as1 = user_list;
1591		     (as1 != NULL) && (as1->next != as);
1592		     as1 = as1->next)
1593			;
1594		if (as1 == NULL)
1595			pr_err("filp not in user list\n");
1596		else
1597			as1->next = as->next;
1598	}
1599	spin_unlock(&user_list_lock);
1600	kfree(as);
1601	return 0;
1602}
1603
1604static int do_open(struct inode *inode, struct file *filp)
1605{
1606	struct apm_user *as;
1607
1608	as = kmalloc(sizeof(*as), GFP_KERNEL);
1609	if (as == NULL)
1610		return -ENOMEM;
1611
1612	as->magic = APM_BIOS_MAGIC;
1613	as->event_tail = as->event_head = 0;
1614	as->suspends_pending = as->standbys_pending = 0;
1615	as->suspends_read = as->standbys_read = 0;
1616	/*
1617	 * XXX - this is a tiny bit broken, when we consider BSD
1618	 * process accounting. If the device is opened by root, we
1619	 * instantly flag that we used superuser privs. Who knows,
1620	 * we might close the device immediately without doing a
1621	 * privileged operation -- cevans
1622	 */
1623	as->suser = capable(CAP_SYS_ADMIN);
1624	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1625	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1626	spin_lock(&user_list_lock);
1627	as->next = user_list;
1628	user_list = as;
1629	spin_unlock(&user_list_lock);
1630	filp->private_data = as;
1631	return 0;
1632}
1633
1634#ifdef CONFIG_PROC_FS
1635static int proc_apm_show(struct seq_file *m, void *v)
1636{
1637	unsigned short	bx;
1638	unsigned short	cx;
1639	unsigned short	dx;
1640	int		error;
1641	unsigned short  ac_line_status = 0xff;
1642	unsigned short  battery_status = 0xff;
1643	unsigned short  battery_flag   = 0xff;
1644	int		percentage     = -1;
1645	int             time_units     = -1;
1646	char            *units         = "?";
1647
1648	if ((num_online_cpus() == 1) &&
1649	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1650		ac_line_status = (bx >> 8) & 0xff;
1651		battery_status = bx & 0xff;
1652		if ((cx & 0xff) != 0xff)
1653			percentage = cx & 0xff;
1654
1655		if (apm_info.connection_version > 0x100) {
1656			battery_flag = (cx >> 8) & 0xff;
1657			if (dx != 0xffff) {
1658				units = (dx & 0x8000) ? "min" : "sec";
1659				time_units = dx & 0x7fff;
1660			}
1661		}
1662	}
1663	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1664	   from the Get Power Status (0x0a) call unless otherwise noted.
1665
1666	   0) Linux driver version (this will change if format changes)
1667	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1668	   2) APM flags from APM Installation Check (0x00):
1669	      bit 0: APM_16_BIT_SUPPORT
1670	      bit 1: APM_32_BIT_SUPPORT
1671	      bit 2: APM_IDLE_SLOWS_CLOCK
1672	      bit 3: APM_BIOS_DISABLED
1673	      bit 4: APM_BIOS_DISENGAGED
1674	   3) AC line status
1675	      0x00: Off-line
1676	      0x01: On-line
1677	      0x02: On backup power (BIOS >= 1.1 only)
1678	      0xff: Unknown
1679	   4) Battery status
1680	      0x00: High
1681	      0x01: Low
1682	      0x02: Critical
1683	      0x03: Charging
1684	      0x04: Selected battery not present (BIOS >= 1.2 only)
1685	      0xff: Unknown
1686	   5) Battery flag
1687	      bit 0: High
1688	      bit 1: Low
1689	      bit 2: Critical
1690	      bit 3: Charging
1691	      bit 7: No system battery
1692	      0xff: Unknown
1693	   6) Remaining battery life (percentage of charge):
1694	      0-100: valid
1695	      -1: Unknown
1696	   7) Remaining battery life (time units):
1697	      Number of remaining minutes or seconds
1698	      -1: Unknown
1699	   8) min = minutes; sec = seconds */
1700
1701	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1702		   driver_version,
1703		   (apm_info.bios.version >> 8) & 0xff,
1704		   apm_info.bios.version & 0xff,
1705		   apm_info.bios.flags,
1706		   ac_line_status,
1707		   battery_status,
1708		   battery_flag,
1709		   percentage,
1710		   time_units,
1711		   units);
1712	return 0;
1713}
1714#endif
1715
1716static int apm(void *unused)
1717{
1718	unsigned short	bx;
1719	unsigned short	cx;
1720	unsigned short	dx;
1721	int		error;
1722	char 		*power_stat;
1723	char 		*bat_stat;
1724
1725	/* 2002/08/01 - WT
1726	 * This is to avoid random crashes at boot time during initialization
1727	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1728	 * Some bioses don't like being called from CPU != 0.
1729	 * Method suggested by Ingo Molnar.
1730	 */
1731	set_cpus_allowed_ptr(current, cpumask_of(0));
1732	BUG_ON(smp_processor_id() != 0);
1733
1734	if (apm_info.connection_version == 0) {
1735		apm_info.connection_version = apm_info.bios.version;
1736		if (apm_info.connection_version > 0x100) {
1737			/*
1738			 * We only support BIOSs up to version 1.2
1739			 */
1740			if (apm_info.connection_version > 0x0102)
1741				apm_info.connection_version = 0x0102;
1742			error = apm_driver_version(&apm_info.connection_version);
1743			if (error != APM_SUCCESS) {
1744				apm_error("driver version", error);
1745				/* Fall back to an APM 1.0 connection. */
1746				apm_info.connection_version = 0x100;
1747			}
1748		}
1749	}
1750
1751	if (debug)
1752		printk(KERN_INFO "apm: Connection version %d.%d\n",
1753			(apm_info.connection_version >> 8) & 0xff,
1754			apm_info.connection_version & 0xff);
1755
1756#ifdef CONFIG_APM_DO_ENABLE
1757	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1758		/*
1759		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1760		 * is booted with PM disabled but not in the docking station.
1761		 * Unfortunate ...
1762		 */
1763		error = apm_enable_power_management(1);
1764		if (error) {
1765			apm_error("enable power management", error);
1766			return -1;
1767		}
1768	}
1769#endif
1770
1771	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1772	    && (apm_info.connection_version > 0x0100)) {
1773		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1774		if (error) {
1775			apm_error("engage power management", error);
1776			return -1;
1777		}
1778	}
1779
1780	if (debug && (num_online_cpus() == 1 || smp)) {
1781		error = apm_get_power_status(&bx, &cx, &dx);
1782		if (error)
1783			printk(KERN_INFO "apm: power status not available\n");
1784		else {
1785			switch ((bx >> 8) & 0xff) {
1786			case 0:
1787				power_stat = "off line";
1788				break;
1789			case 1:
1790				power_stat = "on line";
1791				break;
1792			case 2:
1793				power_stat = "on backup power";
1794				break;
1795			default:
1796				power_stat = "unknown";
1797				break;
1798			}
1799			switch (bx & 0xff) {
1800			case 0:
1801				bat_stat = "high";
1802				break;
1803			case 1:
1804				bat_stat = "low";
1805				break;
1806			case 2:
1807				bat_stat = "critical";
1808				break;
1809			case 3:
1810				bat_stat = "charging";
1811				break;
1812			default:
1813				bat_stat = "unknown";
1814				break;
1815			}
1816			printk(KERN_INFO
1817			       "apm: AC %s, battery status %s, battery life ",
1818			       power_stat, bat_stat);
1819			if ((cx & 0xff) == 0xff)
1820				printk("unknown\n");
1821			else
1822				printk("%d%%\n", cx & 0xff);
1823			if (apm_info.connection_version > 0x100) {
1824				printk(KERN_INFO
1825				       "apm: battery flag 0x%02x, battery life ",
1826				       (cx >> 8) & 0xff);
1827				if (dx == 0xffff)
1828					printk("unknown\n");
1829				else
1830					printk("%d %s\n", dx & 0x7fff,
1831					       (dx & 0x8000) ?
1832					       "minutes" : "seconds");
1833			}
1834		}
1835	}
1836
1837	/* Install our power off handler.. */
1838	if (power_off)
1839		pm_power_off = apm_power_off;
1840
1841	if (num_online_cpus() == 1 || smp) {
1842#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1843		console_blank_hook = apm_console_blank;
1844#endif
1845		apm_mainloop();
1846#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1847		console_blank_hook = NULL;
1848#endif
1849	}
1850
1851	return 0;
1852}
1853
1854#ifndef MODULE
1855static int __init apm_setup(char *str)
1856{
1857	int invert;
1858
1859	while ((str != NULL) && (*str != '\0')) {
1860		if (strncmp(str, "off", 3) == 0)
1861			apm_disabled = 1;
1862		if (strncmp(str, "on", 2) == 0)
1863			apm_disabled = 0;
1864		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1865		    (strncmp(str, "bounce_interval=", 16) == 0))
1866			bounce_interval = simple_strtol(str + 16, NULL, 0);
1867		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1868		    (strncmp(str, "idle_threshold=", 15) == 0))
1869			idle_threshold = simple_strtol(str + 15, NULL, 0);
1870		if ((strncmp(str, "idle-period=", 12) == 0) ||
1871		    (strncmp(str, "idle_period=", 12) == 0))
1872			idle_period = simple_strtol(str + 12, NULL, 0);
1873		invert = (strncmp(str, "no-", 3) == 0) ||
1874			(strncmp(str, "no_", 3) == 0);
1875		if (invert)
1876			str += 3;
1877		if (strncmp(str, "debug", 5) == 0)
1878			debug = !invert;
1879		if ((strncmp(str, "power-off", 9) == 0) ||
1880		    (strncmp(str, "power_off", 9) == 0))
1881			power_off = !invert;
1882		if (strncmp(str, "smp", 3) == 0) {
1883			smp = !invert;
1884			idle_threshold = 100;
1885		}
1886		if ((strncmp(str, "allow-ints", 10) == 0) ||
1887		    (strncmp(str, "allow_ints", 10) == 0))
1888			apm_info.allow_ints = !invert;
1889		if ((strncmp(str, "broken-psr", 10) == 0) ||
1890		    (strncmp(str, "broken_psr", 10) == 0))
1891			apm_info.get_power_status_broken = !invert;
1892		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1893		    (strncmp(str, "realmode_power_off", 18) == 0))
1894			apm_info.realmode_power_off = !invert;
1895		str = strchr(str, ',');
1896		if (str != NULL)
1897			str += strspn(str, ", \t");
1898	}
1899	return 1;
1900}
1901
1902__setup("apm=", apm_setup);
1903#endif
1904
1905static const struct file_operations apm_bios_fops = {
1906	.owner		= THIS_MODULE,
1907	.read		= do_read,
1908	.poll		= do_poll,
1909	.unlocked_ioctl	= do_ioctl,
1910	.open		= do_open,
1911	.release	= do_release,
1912	.llseek		= noop_llseek,
1913};
1914
1915static struct miscdevice apm_device = {
1916	APM_MINOR_DEV,
1917	"apm_bios",
1918	&apm_bios_fops
1919};
1920
1921
1922/* Simple "print if true" callback */
1923static int __init print_if_true(const struct dmi_system_id *d)
1924{
1925	printk("%s\n", d->ident);
1926	return 0;
1927}
1928
1929/*
1930 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1931 * disabled before the suspend. Linux used to get terribly confused by that.
1932 */
1933static int __init broken_ps2_resume(const struct dmi_system_id *d)
1934{
1935	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1936	       "workaround hopefully not needed.\n", d->ident);
1937	return 0;
1938}
1939
1940/* Some bioses have a broken protected mode poweroff and need to use realmode */
1941static int __init set_realmode_power_off(const struct dmi_system_id *d)
1942{
1943	if (apm_info.realmode_power_off == 0) {
1944		apm_info.realmode_power_off = 1;
1945		printk(KERN_INFO "%s bios detected. "
1946		       "Using realmode poweroff only.\n", d->ident);
1947	}
1948	return 0;
1949}
1950
1951/* Some laptops require interrupts to be enabled during APM calls */
1952static int __init set_apm_ints(const struct dmi_system_id *d)
1953{
1954	if (apm_info.allow_ints == 0) {
1955		apm_info.allow_ints = 1;
1956		printk(KERN_INFO "%s machine detected. "
1957		       "Enabling interrupts during APM calls.\n", d->ident);
1958	}
1959	return 0;
1960}
1961
1962/* Some APM bioses corrupt memory or just plain do not work */
1963static int __init apm_is_horked(const struct dmi_system_id *d)
1964{
1965	if (apm_info.disabled == 0) {
1966		apm_info.disabled = 1;
1967		printk(KERN_INFO "%s machine detected. "
1968		       "Disabling APM.\n", d->ident);
1969	}
1970	return 0;
1971}
1972
1973static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1974{
1975	if (apm_info.disabled == 0) {
1976		apm_info.disabled = 1;
1977		printk(KERN_INFO "%s machine detected. "
1978		       "Disabling APM.\n", d->ident);
1979		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1980		printk(KERN_INFO "download from support.intel.com\n");
1981	}
1982	return 0;
1983}
1984
1985/* Some APM bioses hang on APM idle calls */
1986static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1987{
1988	if (apm_info.forbid_idle == 0) {
1989		apm_info.forbid_idle = 1;
1990		printk(KERN_INFO "%s machine detected. "
1991		       "Disabling APM idle calls.\n", d->ident);
1992	}
1993	return 0;
1994}
1995
1996/*
1997 *  Check for clue free BIOS implementations who use
1998 *  the following QA technique
1999 *
2000 *      [ Write BIOS Code ]<------
2001 *               |                ^
2002 *      < Does it Compile >----N--
2003 *               |Y               ^
2004 *	< Does it Boot Win98 >-N--
2005 *               |Y
2006 *           [Ship It]
2007 *
2008 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2009 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2010 */
2011static int __init broken_apm_power(const struct dmi_system_id *d)
2012{
2013	apm_info.get_power_status_broken = 1;
2014	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2015	       "disabling power status reporting.\n");
2016	return 0;
2017}
2018
2019/*
2020 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2021 * have this problem).
2022 */
2023static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2024{
2025	apm_info.get_power_status_swabinminutes = 1;
2026	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2027	       "in minutes and wrong byte order.\n");
2028	return 0;
2029}
2030
2031static const struct dmi_system_id apm_dmi_table[] __initconst = {
2032	{
2033		print_if_true,
2034		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2035		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2036			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2037	},
2038	{	/* Handle problems with APM on the C600 */
2039		broken_ps2_resume, "Dell Latitude C600",
2040		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2041			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2042	},
2043	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2044		set_apm_ints, "Dell Latitude",
2045		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2046			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2047	},
2048	{	/* APM crashes */
2049		apm_is_horked, "Dell Inspiron 2500",
2050		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2051			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2052			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2053			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2054	},
2055	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2056		set_apm_ints, "Dell Inspiron", {
2057			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2058			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2059	},
2060	{	/* Handle problems with APM on Inspiron 5000e */
2061		broken_apm_power, "Dell Inspiron 5000e",
2062		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2063			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2064			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2065	},
2066	{	/* Handle problems with APM on Inspiron 2500 */
2067		broken_apm_power, "Dell Inspiron 2500",
2068		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2069			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2070			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2071	},
2072	{	/* APM crashes */
2073		apm_is_horked, "Dell Dimension 4100",
2074		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2075			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2076			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2077			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2078	},
2079	{	/* Allow interrupts during suspend on Compaq Laptops*/
2080		set_apm_ints, "Compaq 12XL125",
2081		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2082			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2083			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2084			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2085	},
2086	{	/* Allow interrupts during APM or the clock goes slow */
2087		set_apm_ints, "ASUSTeK",
2088		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2089			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2090	},
2091	{	/* APM blows on shutdown */
2092		apm_is_horked, "ABIT KX7-333[R]",
2093		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2094			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2095	},
2096	{	/* APM crashes */
2097		apm_is_horked, "Trigem Delhi3",
2098		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2099			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2100	},
2101	{	/* APM crashes */
2102		apm_is_horked, "Fujitsu-Siemens",
2103		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2104			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2105	},
2106	{	/* APM crashes */
2107		apm_is_horked_d850md, "Intel D850MD",
2108		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2109			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2110	},
2111	{	/* APM crashes */
2112		apm_is_horked, "Intel D810EMO",
2113		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2114			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2115	},
2116	{	/* APM crashes */
2117		apm_is_horked, "Dell XPS-Z",
2118		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2119			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2120			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2121	},
2122	{	/* APM crashes */
2123		apm_is_horked, "Sharp PC-PJ/AX",
2124		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2125			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2126			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2127			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2128	},
2129	{	/* APM crashes */
2130		apm_is_horked, "Dell Inspiron 2500",
2131		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2132			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2133			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2134			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2135	},
2136	{	/* APM idle hangs */
2137		apm_likes_to_melt, "Jabil AMD",
2138		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2139			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2140	},
2141	{	/* APM idle hangs */
2142		apm_likes_to_melt, "AMI Bios",
2143		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2144			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2145	},
2146	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2147		swab_apm_power_in_minutes, "Sony VAIO",
2148		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2149			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2150			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2151	},
2152	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2153		swab_apm_power_in_minutes, "Sony VAIO",
2154		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2155			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2156			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2157	},
2158	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2159		swab_apm_power_in_minutes, "Sony VAIO",
2160		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2161			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2162			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2163	},
2164	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2165		swab_apm_power_in_minutes, "Sony VAIO",
2166		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2167			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2168			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2169	},
2170	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2171		swab_apm_power_in_minutes, "Sony VAIO",
2172		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2173			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2174			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2175	},
2176	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2177		swab_apm_power_in_minutes, "Sony VAIO",
2178		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2179			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2180			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2181	},
2182	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2183		swab_apm_power_in_minutes, "Sony VAIO",
2184		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2185			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2186			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2187	},
2188	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2189		swab_apm_power_in_minutes, "Sony VAIO",
2190		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2191			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2192			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2193	},
2194	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2195		swab_apm_power_in_minutes, "Sony VAIO",
2196		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2197			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2198			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2199	},
2200	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2201		swab_apm_power_in_minutes, "Sony VAIO",
2202		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2203			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2204			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2205	},
2206
2207	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2208		swab_apm_power_in_minutes, "Sony VAIO",
2209		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2211			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2212	},
2213	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2214		swab_apm_power_in_minutes, "Sony VAIO",
2215		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2216			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2217			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2218	},
2219	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2220		swab_apm_power_in_minutes, "Sony VAIO",
2221		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2222			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2223			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2224	},
2225	{	/* broken PM poweroff bios */
2226		set_realmode_power_off, "Award Software v4.60 PGMA",
2227		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2228			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2229			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2230	},
2231
2232	/* Generic per vendor APM settings  */
2233
2234	{	/* Allow interrupts during suspend on IBM laptops */
2235		set_apm_ints, "IBM",
2236		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2237	},
2238
2239	{ }
2240};
2241
2242/*
2243 * Just start the APM thread. We do NOT want to do APM BIOS
2244 * calls from anything but the APM thread, if for no other reason
2245 * than the fact that we don't trust the APM BIOS. This way,
2246 * most common APM BIOS problems that lead to protection errors
2247 * etc will have at least some level of being contained...
2248 *
2249 * In short, if something bad happens, at least we have a choice
2250 * of just killing the apm thread..
2251 */
2252static int __init apm_init(void)
2253{
2254	struct desc_struct *gdt;
2255	int err;
2256
2257	dmi_check_system(apm_dmi_table);
2258
2259	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2260		printk(KERN_INFO "apm: BIOS not found.\n");
2261		return -ENODEV;
2262	}
2263	printk(KERN_INFO
2264	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2265	       ((apm_info.bios.version >> 8) & 0xff),
2266	       (apm_info.bios.version & 0xff),
2267	       apm_info.bios.flags,
2268	       driver_version);
2269	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2270		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2271		return -ENODEV;
2272	}
2273
2274	if (allow_ints)
2275		apm_info.allow_ints = 1;
2276	if (broken_psr)
2277		apm_info.get_power_status_broken = 1;
2278	if (realmode_power_off)
2279		apm_info.realmode_power_off = 1;
2280	/* User can override, but default is to trust DMI */
2281	if (apm_disabled != -1)
2282		apm_info.disabled = apm_disabled;
2283
2284	/*
2285	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2286	 * but is reportedly a 1.0 BIOS.
2287	 */
2288	if (apm_info.bios.version == 0x001)
2289		apm_info.bios.version = 0x100;
2290
2291	/* BIOS < 1.2 doesn't set cseg_16_len */
2292	if (apm_info.bios.version < 0x102)
2293		apm_info.bios.cseg_16_len = 0; /* 64k */
2294
2295	if (debug) {
2296		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2297			apm_info.bios.cseg, apm_info.bios.offset,
2298			apm_info.bios.cseg_16, apm_info.bios.dseg);
2299		if (apm_info.bios.version > 0x100)
2300			printk(" cseg len %x, dseg len %x",
2301				apm_info.bios.cseg_len,
2302				apm_info.bios.dseg_len);
2303		if (apm_info.bios.version > 0x101)
2304			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2305		printk("\n");
2306	}
2307
2308	if (apm_info.disabled) {
2309		pr_notice("disabled on user request.\n");
2310		return -ENODEV;
2311	}
2312	if ((num_online_cpus() > 1) && !power_off && !smp) {
2313		pr_notice("disabled - APM is not SMP safe.\n");
2314		apm_info.disabled = 1;
2315		return -ENODEV;
2316	}
2317	if (!acpi_disabled) {
2318		pr_notice("overridden by ACPI.\n");
2319		apm_info.disabled = 1;
2320		return -ENODEV;
2321	}
2322
2323	/*
2324	 * Set up the long jump entry point to the APM BIOS, which is called
2325	 * from inline assembly.
2326	 */
2327	apm_bios_entry.offset = apm_info.bios.offset;
2328	apm_bios_entry.segment = APM_CS;
2329
2330	/*
2331	 * The APM 1.1 BIOS is supposed to provide limit information that it
2332	 * recognizes.  Many machines do this correctly, but many others do
2333	 * not restrict themselves to their claimed limit.  When this happens,
2334	 * they will cause a segmentation violation in the kernel at boot time.
2335	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2336	 *
2337	 * Note we only set APM segments on CPU zero, since we pin the APM
2338	 * code to that CPU.
2339	 */
2340	gdt = get_cpu_gdt_rw(0);
2341	set_desc_base(&gdt[APM_CS >> 3],
2342		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2343	set_desc_base(&gdt[APM_CS_16 >> 3],
2344		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2345	set_desc_base(&gdt[APM_DS >> 3],
2346		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2347
2348	proc_create_single("apm", 0, NULL, proc_apm_show);
2349
2350	kapmd_task = kthread_create(apm, NULL, "kapmd");
2351	if (IS_ERR(kapmd_task)) {
2352		pr_err("disabled - Unable to start kernel thread\n");
2353		err = PTR_ERR(kapmd_task);
2354		kapmd_task = NULL;
2355		remove_proc_entry("apm", NULL);
2356		return err;
2357	}
2358	wake_up_process(kapmd_task);
2359
2360	if (num_online_cpus() > 1 && !smp) {
2361		printk(KERN_NOTICE
2362		       "apm: disabled - APM is not SMP safe (power off active).\n");
2363		return 0;
2364	}
2365
2366	/*
2367	 * Note we don't actually care if the misc_device cannot be registered.
2368	 * this driver can do its job without it, even if userspace can't
2369	 * control it.  just log the error
2370	 */
2371	if (misc_register(&apm_device))
2372		printk(KERN_WARNING "apm: Could not register misc device.\n");
2373
2374	if (HZ != 100)
2375		idle_period = (idle_period * HZ) / 100;
2376	if (idle_threshold < 100) {
2377		cpuidle_poll_state_init(&apm_idle_driver);
2378		if (!cpuidle_register_driver(&apm_idle_driver))
2379			if (cpuidle_register_device(&apm_cpuidle_device))
2380				cpuidle_unregister_driver(&apm_idle_driver);
2381	}
2382
2383	return 0;
2384}
2385
2386static void __exit apm_exit(void)
2387{
2388	int error;
2389
2390	cpuidle_unregister_device(&apm_cpuidle_device);
2391	cpuidle_unregister_driver(&apm_idle_driver);
2392
2393	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2394	    && (apm_info.connection_version > 0x0100)) {
2395		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2396		if (error)
2397			apm_error("disengage power management", error);
2398	}
2399	misc_deregister(&apm_device);
2400	remove_proc_entry("apm", NULL);
2401	if (power_off)
2402		pm_power_off = NULL;
2403	if (kapmd_task) {
2404		kthread_stop(kapmd_task);
2405		kapmd_task = NULL;
2406	}
2407}
2408
2409module_init(apm_init);
2410module_exit(apm_exit);
2411
2412MODULE_AUTHOR("Stephen Rothwell");
2413MODULE_DESCRIPTION("Advanced Power Management");
2414MODULE_LICENSE("GPL");
2415module_param(debug, bool, 0644);
2416MODULE_PARM_DESC(debug, "Enable debug mode");
2417module_param(power_off, bool, 0444);
2418MODULE_PARM_DESC(power_off, "Enable power off");
2419module_param(bounce_interval, int, 0444);
2420MODULE_PARM_DESC(bounce_interval,
2421		"Set the number of ticks to ignore suspend bounces");
2422module_param(allow_ints, bool, 0444);
2423MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2424module_param(broken_psr, bool, 0444);
2425MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2426module_param(realmode_power_off, bool, 0444);
2427MODULE_PARM_DESC(realmode_power_off,
2428		"Switch to real mode before powering off");
2429module_param(idle_threshold, int, 0444);
2430MODULE_PARM_DESC(idle_threshold,
2431	"System idle percentage above which to make APM BIOS idle calls");
2432module_param(idle_period, int, 0444);
2433MODULE_PARM_DESC(idle_period,
2434	"Period (in sec/100) over which to calculate the idle percentage");
2435module_param(smp, bool, 0444);
2436MODULE_PARM_DESC(smp,
2437	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2438MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
v6.13.7
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* -*- linux-c -*-
   3 * APM BIOS driver for Linux
   4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   5 *
   6 * Initial development of this driver was funded by NEC Australia P/L
   7 *	and NEC Corporation
   8 *
   9 * October 1995, Rik Faith (faith@cs.unc.edu):
  10 *    Minor enhancements and updates (to the patch set) for 1.3.x
  11 *    Documentation
  12 * January 1996, Rik Faith (faith@cs.unc.edu):
  13 *    Make /proc/apm easy to format (bump driver version)
  14 * March 1996, Rik Faith (faith@cs.unc.edu):
  15 *    Prohibit APM BIOS calls unless apm_enabled.
  16 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  18 *    Version 1.0 and 1.1
  19 * May 1996, Version 1.2
  20 * Feb 1998, Version 1.3
  21 * Feb 1998, Version 1.4
  22 * Aug 1998, Version 1.5
  23 * Sep 1998, Version 1.6
  24 * Nov 1998, Version 1.7
  25 * Jan 1999, Version 1.8
  26 * Jan 1999, Version 1.9
  27 * Oct 1999, Version 1.10
  28 * Nov 1999, Version 1.11
  29 * Jan 2000, Version 1.12
  30 * Feb 2000, Version 1.13
  31 * Nov 2000, Version 1.14
  32 * Oct 2001, Version 1.15
  33 * Jan 2002, Version 1.16
  34 * Oct 2002, Version 1.16ac
  35 *
  36 * History:
  37 *    0.6b: first version in official kernel, Linux 1.3.46
  38 *    0.7: changed /proc/apm format, Linux 1.3.58
  39 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  40 *    0.9: only call bios if bios is present, Linux 1.3.72
  41 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  42 *         Linux 1.3.85
  43 *    1.1: support user-space standby and suspend, power off after system
  44 *         halted, Linux 1.3.98
  45 *    1.2: When resetting RTC after resume, take care so that the time
  46 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  47 *         <jtoth@princeton.edu>); improve interaction between
  48 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  49 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  50 *	   levels to the printk calls. APM is not defined for SMP machines.
  51 *         The new replacement for it is, but Linux doesn't yet support this.
  52 *         Alan Cox Linux 2.1.55
  53 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  54 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  55 *         Dean Gaudet <dgaudet@arctic.org>.
  56 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  57 *    1.5: Fix segment register reloading (in case of bad segments saved
  58 *         across BIOS call).
  59 *         Stephen Rothwell
  60 *    1.6: Cope with compiler/assembler differences.
  61 *         Only try to turn off the first display device.
  62 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  63 *                   <echter@informatik.uni-rostock.de>
  64 *         Stephen Rothwell
  65 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  66 *         to reflect current state of APM BIOS.
  67 *         Chris Rankin <rankinc@bellsouth.net>
  68 *         Reset interrupt 0 timer to 100Hz after suspend
  69 *         Chad Miller <cmiller@surfsouth.com>
  70 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  71 *         Richard Gooch <rgooch@atnf.csiro.au>
  72 *         Allow boot time disabling of APM
  73 *         Make boot messages far less verbose by default
  74 *         Make asm safer
  75 *         Stephen Rothwell
  76 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  77 *         Richard Gooch <rgooch@atnf.csiro.au>
  78 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  79 *         remove dependency on CONFIG_PROC_FS
  80 *         Stephen Rothwell
  81 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  82 *         Try to cope with BIOS's that need to have all display
  83 *         devices blanked and not just the first one.
  84 *         Ross Paterson <ross@soi.city.ac.uk>
  85 *         Fix segment limit setting it has always been wrong as
  86 *         the segments needed to have byte granularity.
  87 *         Mark a few things __init.
  88 *         Add hack to allow power off of SMP systems by popular request.
  89 *         Use CONFIG_SMP instead of __SMP__
  90 *         Ignore BOUNCES for three seconds.
  91 *         Stephen Rothwell
  92 *   1.10: Fix for Thinkpad return code.
  93 *         Merge 2.2 and 2.3 drivers.
  94 *         Remove APM dependencies in arch/i386/kernel/process.c
  95 *         Remove APM dependencies in drivers/char/sysrq.c
  96 *         Reset time across standby.
  97 *         Allow more initialisation on SMP.
  98 *         Remove CONFIG_APM_POWER_OFF and make it boot time
  99 *         configurable (default on).
 100 *         Make debug only a boot time parameter (remove APM_DEBUG).
 101 *         Try to blank all devices on any error.
 102 *   1.11: Remove APM dependencies in drivers/char/console.c
 103 *         Check nr_running to detect if we are idle (from
 104 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 105 *         Fix for bioses that don't zero the top part of the
 106 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 107 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 108 *         Real mode power off patch (Walter Hofmann
 109 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 110 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 111 *         the code away anyway (smp_num_cpus == 1 in UP)
 112 *         noted by Artur Skawina <skawina@geocities.com>.
 113 *         Make power off under SMP work again.
 114 *         Fix thinko with initial engaging of BIOS.
 115 *         Make sure power off only happens on CPU 0
 116 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 117 *         Do error notification to user mode if BIOS calls fail.
 118 *         Move entrypoint offset fix to ...boot/setup.S
 119 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 120 *         Remove smp-power-off. SMP users must now specify
 121 *         "apm=power-off" on the kernel command line. Suggested
 122 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 123 *         <alan@lxorguk.ukuu.org.uk>.
 124 *         Register the /proc/apm entry even on SMP so that
 125 *         scripts that check for it before doing power off
 126 *         work (Jim Avera <jima@hal.com>).
 127 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 128 *         <andy_henroid@yahoo.com>).
 129 *         Modularize the code.
 130 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 131 *         is now the way life works).
 132 *         Fix thinko in suspend() (wrong return).
 133 *         Notify drivers on critical suspend.
 134 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 135 *         modified by sfr).
 136 *         Disable interrupts while we are suspended (Andy Henroid
 137 *         <andy_henroid@yahoo.com> fixed by sfr).
 138 *         Make power off work on SMP again (Tony Hoyle
 139 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 140 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 141 *         interval is now configurable.
 142 *   1.14: Make connection version persist across module unload/load.
 143 *         Enable and engage power management earlier.
 144 *         Disengage power management on module unload.
 145 *         Changed to use the sysrq-register hack for registering the
 146 *         power off function called by magic sysrq based upon discussions
 147 *         in irc://irc.openprojects.net/#kernelnewbies
 148 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 149 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 150 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 151 *         Work around byte swap bug in one of the Vaio's BIOS's
 152 *         (Marc Boucher <marc@mbsi.ca>).
 153 *         Exposed the disable flag to dmi so that we can handle known
 154 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 155 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 156 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 157 *         If an APM idle fails log it and idle sensibly
 158 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 159 *         Don't expect replies from clients who open the device O_RDONLY.
 160 *         (Idea from Thomas Hood)
 161 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 162 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 163 *         Notify listeners of standby or suspend events before notifying
 164 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 165 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 166 *         Ignore first resume after we generate our own resume event
 167 *         after a suspend (Thomas Hood)
 168 *         Daemonize now gets rid of our controlling terminal (sfr).
 169 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 170 *         idle_threshold (sfr).
 171 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 172 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 173 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 174 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 175 *
 176 * APM 1.1 Reference:
 177 *
 178 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 179 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 180 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 181 *
 182 * [This document is available free from Intel by calling 800.628.8686 (fax
 183 * 916.356.6100) or 800.548.4725; or from
 184 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 185 * available from Microsoft by calling 206.882.8080.]
 186 *
 187 * APM 1.2 Reference:
 188 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 189 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 190 *
 191 * [This document is available from Microsoft at:
 192 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 193 */
 194
 195#define pr_fmt(fmt) "apm: " fmt
 196
 197#include <linux/module.h>
 198
 199#include <linux/poll.h>
 200#include <linux/types.h>
 201#include <linux/stddef.h>
 202#include <linux/timer.h>
 203#include <linux/fcntl.h>
 204#include <linux/slab.h>
 205#include <linux/stat.h>
 206#include <linux/proc_fs.h>
 207#include <linux/seq_file.h>
 208#include <linux/miscdevice.h>
 209#include <linux/apm_bios.h>
 210#include <linux/init.h>
 211#include <linux/time.h>
 212#include <linux/sched/signal.h>
 213#include <linux/sched/cputime.h>
 214#include <linux/pm.h>
 215#include <linux/capability.h>
 216#include <linux/device.h>
 217#include <linux/kernel.h>
 218#include <linux/freezer.h>
 219#include <linux/smp.h>
 220#include <linux/dmi.h>
 221#include <linux/suspend.h>
 222#include <linux/kthread.h>
 223#include <linux/jiffies.h>
 224#include <linux/acpi.h>
 225#include <linux/syscore_ops.h>
 226#include <linux/i8253.h>
 227#include <linux/cpuidle.h>
 228
 229#include <linux/uaccess.h>
 230#include <asm/desc.h>
 231#include <asm/olpc.h>
 232#include <asm/paravirt.h>
 233#include <asm/reboot.h>
 234#include <asm/nospec-branch.h>
 235#include <asm/ibt.h>
 236
 237#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 238extern int (*console_blank_hook)(int);
 239#endif
 240
 241/*
 
 
 
 
 
 
 242 * Various options can be changed at boot time as follows:
 243 * (We allow underscores for compatibility with the modules code)
 244 *	apm=on/off			enable/disable APM
 245 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 246 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 247 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 248 *	    					powering off
 249 *	    [no-]debug			log some debugging messages
 250 *	    [no-]power[-_]off		power off on shutdown
 251 *	    [no-]smp			Use apm even on an SMP box
 252 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 253 *	    				bounces
 254 *          idle[-_]threshold=<n>       System idle percentage above which to
 255 *                                      make APM BIOS idle calls. Set it to
 256 *                                      100 to disable.
 257 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 258 *                                      which the idle percentage is
 259 *                                      calculated.
 260 */
 261
 262/* KNOWN PROBLEM MACHINES:
 263 *
 264 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 265 *                         [Confirmed by TI representative]
 266 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 267 *                    [Confirmed by BIOS disassembly]
 268 *                    [This may work now ...]
 269 * P: Toshiba 1950S: battery life information only gets updated after resume
 270 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 271 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 272 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 273 * 	Neale Banks <neale@lowendale.com.au> December 2000
 274 *
 275 * Legend: U = unusable with APM patches
 276 *         P = partially usable with APM patches
 277 */
 278
 279/*
 280 * Define as 1 to make the driver always call the APM BIOS busy
 281 * routine even if the clock was not reported as slowed by the
 282 * idle routine.  Otherwise, define as 0.
 283 */
 284#define ALWAYS_CALL_BUSY   1
 285
 286/*
 287 * Define to make the APM BIOS calls zero all data segment registers (so
 288 * that an incorrect BIOS implementation will cause a kernel panic if it
 289 * tries to write to arbitrary memory).
 290 */
 291#define APM_ZERO_SEGS
 292
 293#include <asm/apm.h>
 294
 295/*
 296 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 297 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 298 * David Chen <chen@ctpa04.mit.edu>
 299 */
 300#undef INIT_TIMER_AFTER_SUSPEND
 301
 302#ifdef INIT_TIMER_AFTER_SUSPEND
 303#include <linux/timex.h>
 304#include <asm/io.h>
 305#include <linux/delay.h>
 306#endif
 307
 308/*
 309 * Need to poll the APM BIOS every second
 310 */
 311#define APM_CHECK_TIMEOUT	(HZ)
 312
 313/*
 314 * Ignore suspend events for this amount of time after a resume
 315 */
 316#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 317
 318/*
 319 * Maximum number of events stored
 320 */
 321#define APM_MAX_EVENTS		20
 322
 323/*
 324 * The per-file APM data
 325 */
 326struct apm_user {
 327	int		magic;
 328	struct apm_user *next;
 329	unsigned int	suser: 1;
 330	unsigned int	writer: 1;
 331	unsigned int	reader: 1;
 332	unsigned int	suspend_wait: 1;
 333	int		suspend_result;
 334	int		suspends_pending;
 335	int		standbys_pending;
 336	int		suspends_read;
 337	int		standbys_read;
 338	int		event_head;
 339	int		event_tail;
 340	apm_event_t	events[APM_MAX_EVENTS];
 341};
 342
 343/*
 344 * The magic number in apm_user
 345 */
 346#define APM_BIOS_MAGIC		0x4101
 347
 348/*
 349 * idle percentage above which bios idle calls are done
 350 */
 351#ifdef CONFIG_APM_CPU_IDLE
 352#define DEFAULT_IDLE_THRESHOLD	95
 353#else
 354#define DEFAULT_IDLE_THRESHOLD	100
 355#endif
 356#define DEFAULT_IDLE_PERIOD	(100 / 3)
 357
 358static int apm_cpu_idle(struct cpuidle_device *dev,
 359			struct cpuidle_driver *drv, int index);
 360
 361static struct cpuidle_driver apm_idle_driver = {
 362	.name = "apm_idle",
 363	.owner = THIS_MODULE,
 364	.states = {
 365		{ /* entry 0 is for polling */ },
 366		{ /* entry 1 is for APM idle */
 367			.name = "APM",
 368			.desc = "APM idle",
 369			.exit_latency = 250,	/* WAG */
 370			.target_residency = 500,	/* WAG */
 371			.enter = &apm_cpu_idle
 372		},
 373	},
 374	.state_count = 2,
 375};
 376
 377static struct cpuidle_device apm_cpuidle_device;
 378
 379/*
 380 * Local variables
 381 */
 382__visible struct {
 383	unsigned long	offset;
 384	unsigned short	segment;
 385} apm_bios_entry;
 386static int clock_slowed;
 387static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 388static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 389static int suspends_pending;
 390static int standbys_pending;
 391static int ignore_sys_suspend;
 392static int ignore_normal_resume;
 393static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 394
 395static bool debug __read_mostly;
 396static bool smp __read_mostly;
 397static int apm_disabled = -1;
 398#ifdef CONFIG_SMP
 399static bool power_off;
 400#else
 401static bool power_off = 1;
 402#endif
 403static bool realmode_power_off;
 404#ifdef CONFIG_APM_ALLOW_INTS
 405static bool allow_ints = 1;
 406#else
 407static bool allow_ints;
 408#endif
 409static bool broken_psr;
 410
 411static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 412static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 413static struct apm_user *user_list;
 414static DEFINE_SPINLOCK(user_list_lock);
 415static DEFINE_MUTEX(apm_mutex);
 416
 417/*
 418 * Set up a segment that references the real mode segment 0x40
 419 * that extends up to the end of page zero (that we have reserved).
 420 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 421 * even though they are called in protected mode.
 422 */
 423static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(DESC_DATA32_BIOS,
 424			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 425
 426static const char driver_version[] = "1.16ac";	/* no spaces */
 427
 428static struct task_struct *kapmd_task;
 429
 430/*
 431 *	APM event names taken from the APM 1.2 specification. These are
 432 *	the message codes that the BIOS uses to tell us about events
 433 */
 434static const char * const apm_event_name[] = {
 435	"system standby",
 436	"system suspend",
 437	"normal resume",
 438	"critical resume",
 439	"low battery",
 440	"power status change",
 441	"update time",
 442	"critical suspend",
 443	"user standby",
 444	"user suspend",
 445	"system standby resume",
 446	"capabilities change"
 447};
 448#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 449
 450typedef struct lookup_t {
 451	int	key;
 452	char 	*msg;
 453} lookup_t;
 454
 455/*
 456 *	The BIOS returns a set of standard error codes in AX when the
 457 *	carry flag is set.
 458 */
 459
 460static const lookup_t error_table[] = {
 461/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 462	{ APM_DISABLED,		"Power management disabled" },
 463	{ APM_CONNECTED,	"Real mode interface already connected" },
 464	{ APM_NOT_CONNECTED,	"Interface not connected" },
 465	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 466/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 467	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 468	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 469	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 470	{ APM_BAD_PARAM,	"Parameter out of range" },
 471	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 472	{ APM_BAD_FUNCTION,     "Function not supported" },
 473	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 474	{ APM_BAD_STATE,	"Unable to enter requested state" },
 475/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 476	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 477	{ APM_NOT_PRESENT,	"No APM present" }
 478};
 479#define ERROR_COUNT	ARRAY_SIZE(error_table)
 480
 481/**
 482 *	apm_error	-	display an APM error
 483 *	@str: information string
 484 *	@err: APM BIOS return code
 485 *
 486 *	Write a meaningful log entry to the kernel log in the event of
 487 *	an APM error.  Note that this also handles (negative) kernel errors.
 488 */
 489
 490static void apm_error(char *str, int err)
 491{
 492	int i;
 493
 494	for (i = 0; i < ERROR_COUNT; i++)
 495		if (error_table[i].key == err)
 496			break;
 497	if (i < ERROR_COUNT)
 498		pr_notice("%s: %s\n", str, error_table[i].msg);
 499	else if (err < 0)
 500		pr_notice("%s: linux error code %i\n", str, err);
 501	else
 502		pr_notice("%s: unknown error code %#2.2x\n",
 503		       str, err);
 504}
 505
 506/*
 507 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 508 * apm_info.allow_ints, we are being really paranoid here!  Not only
 509 * are interrupts disabled, but all the segment registers (except SS)
 510 * are saved and zeroed this means that if the BIOS tries to reference
 511 * any data without explicitly loading the segment registers, the kernel
 512 * will fault immediately rather than have some unforeseen circumstances
 513 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 514 * this depends on CS referring to the same physical memory as DS so that
 515 * DS can be zeroed before the call. Unfortunately, we can't do anything
 516 * about the stack segment/pointer.  Also, we tell the compiler that
 517 * everything could change.
 518 *
 519 * Also, we KNOW that for the non error case of apm_bios_call, there
 520 * is no useful data returned in the low order 8 bits of eax.
 521 */
 522
 523static inline unsigned long __apm_irq_save(void)
 524{
 525	unsigned long flags;
 526	local_save_flags(flags);
 527	if (apm_info.allow_ints) {
 528		if (irqs_disabled_flags(flags))
 529			local_irq_enable();
 530	} else
 531		local_irq_disable();
 532
 533	return flags;
 534}
 535
 536#define apm_irq_save(flags) \
 537	do { flags = __apm_irq_save(); } while (0)
 538
 539static inline void apm_irq_restore(unsigned long flags)
 540{
 541	if (irqs_disabled_flags(flags))
 542		local_irq_disable();
 543	else if (irqs_disabled())
 544		local_irq_enable();
 545}
 546
 547#ifdef APM_ZERO_SEGS
 548#	define APM_DECL_SEGS \
 549		unsigned int saved_fs; unsigned int saved_gs;
 550#	define APM_DO_SAVE_SEGS \
 551		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 552#	define APM_DO_RESTORE_SEGS \
 553		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 554#else
 555#	define APM_DECL_SEGS
 556#	define APM_DO_SAVE_SEGS
 557#	define APM_DO_RESTORE_SEGS
 558#endif
 559
 560struct apm_bios_call {
 561	u32 func;
 562	/* In and out */
 563	u32 ebx;
 564	u32 ecx;
 565	/* Out only */
 566	u32 eax;
 567	u32 edx;
 568	u32 esi;
 569
 570	/* Error: -ENOMEM, or bits 8-15 of eax */
 571	int err;
 572};
 573
 574/**
 575 *	__apm_bios_call - Make an APM BIOS 32bit call
 576 *	@_call: pointer to struct apm_bios_call.
 577 *
 578 *	Make an APM call using the 32bit protected mode interface. The
 579 *	caller is responsible for knowing if APM BIOS is configured and
 580 *	enabled. This call can disable interrupts for a long period of
 581 *	time on some laptops.  The return value is in AH and the carry
 582 *	flag is loaded into AL.  If there is an error, then the error
 583 *	code is returned in AH (bits 8-15 of eax) and this function
 584 *	returns non-zero.
 585 *
 586 *	Note: this makes the call on the current CPU.
 587 */
 588static long __apm_bios_call(void *_call)
 589{
 590	APM_DECL_SEGS
 591	unsigned long		flags;
 592	int			cpu;
 593	struct desc_struct	save_desc_40;
 594	struct desc_struct	*gdt;
 595	struct apm_bios_call	*call = _call;
 596	u64			ibt;
 597
 598	cpu = get_cpu();
 599	BUG_ON(cpu != 0);
 600	gdt = get_cpu_gdt_rw(cpu);
 601	save_desc_40 = gdt[0x40 / 8];
 602	gdt[0x40 / 8] = bad_bios_desc;
 603
 604	apm_irq_save(flags);
 605	firmware_restrict_branch_speculation_start();
 606	ibt = ibt_save(true);
 607	APM_DO_SAVE_SEGS;
 608	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 609			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 610			  &call->esi);
 611	APM_DO_RESTORE_SEGS;
 612	ibt_restore(ibt);
 613	firmware_restrict_branch_speculation_end();
 614	apm_irq_restore(flags);
 615	gdt[0x40 / 8] = save_desc_40;
 616	put_cpu();
 617
 618	return call->eax & 0xff;
 619}
 620
 621/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 622static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 623{
 624	int ret;
 625
 626	/* Don't bother with work_on_cpu in the common case, so we don't
 627	 * have to worry about OOM or overhead. */
 628	if (get_cpu() == 0) {
 629		ret = fn(call);
 630		put_cpu();
 631	} else {
 632		put_cpu();
 633		ret = work_on_cpu(0, fn, call);
 634	}
 635
 636	/* work_on_cpu can fail with -ENOMEM */
 637	if (ret < 0)
 638		call->err = ret;
 639	else
 640		call->err = (call->eax >> 8) & 0xff;
 641
 642	return ret;
 643}
 644
 645/**
 646 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 647 *	@call: the apm_bios_call registers.
 648 *
 649 *	If there is an error, it is returned in @call.err.
 650 */
 651static int apm_bios_call(struct apm_bios_call *call)
 652{
 653	return on_cpu0(__apm_bios_call, call);
 654}
 655
 656/**
 657 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 658 *	@_call: pointer to struct apm_bios_call.
 659 *
 660 *	Make a BIOS call that returns one value only, or just status.
 661 *	If there is an error, then the error code is returned in AH
 662 *	(bits 8-15 of eax) and this function returns non-zero (it can
 663 *	also return -ENOMEM). This is used for simpler BIOS operations.
 664 *	This call may hold interrupts off for a long time on some laptops.
 665 *
 666 *	Note: this makes the call on the current CPU.
 667 */
 668static long __apm_bios_call_simple(void *_call)
 669{
 670	u8			error;
 671	APM_DECL_SEGS
 672	unsigned long		flags;
 673	int			cpu;
 674	struct desc_struct	save_desc_40;
 675	struct desc_struct	*gdt;
 676	struct apm_bios_call	*call = _call;
 677	u64			ibt;
 678
 679	cpu = get_cpu();
 680	BUG_ON(cpu != 0);
 681	gdt = get_cpu_gdt_rw(cpu);
 682	save_desc_40 = gdt[0x40 / 8];
 683	gdt[0x40 / 8] = bad_bios_desc;
 684
 685	apm_irq_save(flags);
 686	firmware_restrict_branch_speculation_start();
 687	ibt = ibt_save(true);
 688	APM_DO_SAVE_SEGS;
 689	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 690					 &call->eax);
 691	APM_DO_RESTORE_SEGS;
 692	ibt_restore(ibt);
 693	firmware_restrict_branch_speculation_end();
 694	apm_irq_restore(flags);
 695	gdt[0x40 / 8] = save_desc_40;
 696	put_cpu();
 697	return error;
 698}
 699
 700/**
 701 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 702 *	@func: APM function to invoke
 703 *	@ebx_in: EBX register value for BIOS call
 704 *	@ecx_in: ECX register value for BIOS call
 705 *	@eax: EAX register on return from the BIOS call
 706 *	@err: bits
 707 *
 708 *	Make a BIOS call that returns one value only, or just status.
 709 *	If there is an error, then the error code is returned in @err
 710 *	and this function returns non-zero. This is used for simpler
 711 *	BIOS operations.  This call may hold interrupts off for a long
 712 *	time on some laptops.
 713 */
 714static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 715				int *err)
 716{
 717	struct apm_bios_call call;
 718	int ret;
 719
 720	call.func = func;
 721	call.ebx = ebx_in;
 722	call.ecx = ecx_in;
 723
 724	ret = on_cpu0(__apm_bios_call_simple, &call);
 725	*eax = call.eax;
 726	*err = call.err;
 727	return ret;
 728}
 729
 730/**
 731 *	apm_driver_version	-	APM driver version
 732 *	@val:	loaded with the APM version on return
 733 *
 734 *	Retrieve the APM version supported by the BIOS. This is only
 735 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 736 *	probably present.
 737 *
 738 *	On entry val should point to a value indicating the APM driver
 739 *	version with the high byte being the major and the low byte the
 740 *	minor number both in BCD
 741 *
 742 *	On return it will hold the BIOS revision supported in the
 743 *	same format.
 744 */
 745
 746static int apm_driver_version(u_short *val)
 747{
 748	u32 eax;
 749	int err;
 750
 751	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 752		return err;
 753	*val = eax;
 754	return APM_SUCCESS;
 755}
 756
 757/**
 758 *	apm_get_event	-	get an APM event from the BIOS
 759 *	@event: pointer to the event
 760 *	@info: point to the event information
 761 *
 762 *	The APM BIOS provides a polled information for event
 763 *	reporting. The BIOS expects to be polled at least every second
 764 *	when events are pending. When a message is found the caller should
 765 *	poll until no more messages are present.  However, this causes
 766 *	problems on some laptops where a suspend event notification is
 767 *	not cleared until it is acknowledged.
 768 *
 769 *	Additional information is returned in the info pointer, providing
 770 *	that APM 1.2 is in use. If no messages are pending the value 0x80
 771 *	is returned (No power management events pending).
 772 */
 773static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 774{
 775	struct apm_bios_call call;
 776
 777	call.func = APM_FUNC_GET_EVENT;
 778	call.ebx = call.ecx = 0;
 779
 780	if (apm_bios_call(&call))
 781		return call.err;
 782
 783	*event = call.ebx;
 784	if (apm_info.connection_version < 0x0102)
 785		*info = ~0; /* indicate info not valid */
 786	else
 787		*info = call.ecx;
 788	return APM_SUCCESS;
 789}
 790
 791/**
 792 *	set_power_state	-	set the power management state
 793 *	@what: which items to transition
 794 *	@state: state to transition to
 795 *
 796 *	Request an APM change of state for one or more system devices. The
 797 *	processor state must be transitioned last of all. what holds the
 798 *	class of device in the upper byte and the device number (0xFF for
 799 *	all) for the object to be transitioned.
 800 *
 801 *	The state holds the state to transition to, which may in fact
 802 *	be an acceptance of a BIOS requested state change.
 803 */
 804
 805static int set_power_state(u_short what, u_short state)
 806{
 807	u32 eax;
 808	int err;
 809
 810	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 811		return err;
 812	return APM_SUCCESS;
 813}
 814
 815/**
 816 *	set_system_power_state - set system wide power state
 817 *	@state: which state to enter
 818 *
 819 *	Transition the entire system into a new APM power state.
 820 */
 821
 822static int set_system_power_state(u_short state)
 823{
 824	return set_power_state(APM_DEVICE_ALL, state);
 825}
 826
 827/**
 828 *	apm_do_idle	-	perform power saving
 829 *
 830 *	This function notifies the BIOS that the processor is (in the view
 831 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 832 *	to handle the idle request. On a success the function returns 1
 833 *	if the BIOS did clock slowing or 0 otherwise.
 834 */
 835
 836static int apm_do_idle(void)
 837{
 838	u32 eax;
 839	u8 ret = 0;
 840	int idled = 0;
 841	int err = 0;
 842
 843	if (!need_resched()) {
 844		idled = 1;
 845		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 846	}
 847
 848	if (!idled)
 849		return 0;
 850
 851	if (ret) {
 852		static unsigned long t;
 853
 854		/* This always fails on some SMP boards running UP kernels.
 855		 * Only report the failure the first 5 times.
 856		 */
 857		if (++t < 5) {
 858			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 859			t = jiffies;
 860		}
 861		return -1;
 862	}
 863	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 864	return clock_slowed;
 865}
 866
 867/**
 868 *	apm_do_busy	-	inform the BIOS the CPU is busy
 869 *
 870 *	Request that the BIOS brings the CPU back to full performance.
 871 */
 872
 873static void apm_do_busy(void)
 874{
 875	u32 dummy;
 876	int err;
 877
 878	if (clock_slowed || ALWAYS_CALL_BUSY) {
 879		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 880		clock_slowed = 0;
 881	}
 882}
 883
 884/*
 885 * If no process has really been interested in
 886 * the CPU for some time, we want to call BIOS
 887 * power management - we probably want
 888 * to conserve power.
 889 */
 890#define IDLE_CALC_LIMIT	(HZ * 100)
 891#define IDLE_LEAKY_MAX	16
 892
 893/**
 894 * apm_cpu_idle		-	cpu idling for APM capable Linux
 895 *
 896 * This is the idling function the kernel executes when APM is available. It
 897 * tries to do BIOS powermanagement based on the average system idle time.
 898 * Furthermore it calls the system default idle routine.
 899 */
 900
 901static int apm_cpu_idle(struct cpuidle_device *dev,
 902	struct cpuidle_driver *drv, int index)
 903{
 904	static int use_apm_idle; /* = 0 */
 905	static unsigned int last_jiffies; /* = 0 */
 906	static u64 last_stime; /* = 0 */
 907	u64 stime, utime;
 908
 909	int apm_idle_done = 0;
 910	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 911	unsigned int bucket;
 912
 913recalc:
 914	task_cputime(current, &utime, &stime);
 915	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 916		use_apm_idle = 0;
 917	} else if (jiffies_since_last_check > idle_period) {
 918		unsigned int idle_percentage;
 919
 920		idle_percentage = nsecs_to_jiffies(stime - last_stime);
 921		idle_percentage *= 100;
 922		idle_percentage /= jiffies_since_last_check;
 923		use_apm_idle = (idle_percentage > idle_threshold);
 924		if (apm_info.forbid_idle)
 925			use_apm_idle = 0;
 926	}
 927
 928	last_jiffies = jiffies;
 929	last_stime = stime;
 930
 931	bucket = IDLE_LEAKY_MAX;
 932
 933	while (!need_resched()) {
 934		if (use_apm_idle) {
 935			unsigned int t;
 936
 937			t = jiffies;
 938			switch (apm_do_idle()) {
 939			case 0:
 940				apm_idle_done = 1;
 941				if (t != jiffies) {
 942					if (bucket) {
 943						bucket = IDLE_LEAKY_MAX;
 944						continue;
 945					}
 946				} else if (bucket) {
 947					bucket--;
 948					continue;
 949				}
 950				break;
 951			case 1:
 952				apm_idle_done = 1;
 953				break;
 954			default: /* BIOS refused */
 955				break;
 956			}
 957		}
 958		default_idle();
 959		local_irq_disable();
 960		jiffies_since_last_check = jiffies - last_jiffies;
 961		if (jiffies_since_last_check > idle_period)
 962			goto recalc;
 963	}
 964
 965	if (apm_idle_done)
 966		apm_do_busy();
 967
 968	return index;
 969}
 970
 971/**
 972 *	apm_power_off	-	ask the BIOS to power off
 973 *
 974 *	Handle the power off sequence. This is the one piece of code we
 975 *	will execute even on SMP machines. In order to deal with BIOS
 976 *	bugs we support real mode APM BIOS power off calls. We also make
 977 *	the SMP call on CPU0 as some systems will only honour this call
 978 *	on their first cpu.
 979 */
 980
 981static void apm_power_off(void)
 982{
 983	/* Some bioses don't like being called from CPU != 0 */
 984	if (apm_info.realmode_power_off) {
 985		set_cpus_allowed_ptr(current, cpumask_of(0));
 986		machine_real_restart(MRR_APM);
 987	} else {
 988		(void)set_system_power_state(APM_STATE_OFF);
 989	}
 990}
 991
 992#ifdef CONFIG_APM_DO_ENABLE
 993
 994/**
 995 *	apm_enable_power_management - enable BIOS APM power management
 996 *	@enable: enable yes/no
 997 *
 998 *	Enable or disable the APM BIOS power services.
 999 */
1000
1001static int apm_enable_power_management(int enable)
1002{
1003	u32 eax;
1004	int err;
1005
1006	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1007		return APM_NOT_ENGAGED;
1008	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1009				 enable, &eax, &err))
1010		return err;
1011	if (enable)
1012		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1013	else
1014		apm_info.bios.flags |= APM_BIOS_DISABLED;
1015	return APM_SUCCESS;
1016}
1017#endif
1018
1019/**
1020 *	apm_get_power_status	-	get current power state
1021 *	@status: returned status
1022 *	@bat: battery info
1023 *	@life: estimated life
1024 *
1025 *	Obtain the current power status from the APM BIOS. We return a
1026 *	status which gives the rough battery status, and current power
1027 *	source. The bat value returned give an estimate as a percentage
1028 *	of life and a status value for the battery. The estimated life
1029 *	if reported is a lifetime in seconds/minutes at current power
1030 *	consumption.
1031 */
1032
1033static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1034{
1035	struct apm_bios_call call;
1036
1037	call.func = APM_FUNC_GET_STATUS;
1038	call.ebx = APM_DEVICE_ALL;
1039	call.ecx = 0;
1040
1041	if (apm_info.get_power_status_broken)
1042		return APM_32_UNSUPPORTED;
1043	if (apm_bios_call(&call)) {
1044		if (!call.err)
1045			return APM_NO_ERROR;
1046		return call.err;
1047	}
1048	*status = call.ebx;
1049	*bat = call.ecx;
1050	if (apm_info.get_power_status_swabinminutes) {
1051		*life = swab16((u16)call.edx);
1052		*life |= 0x8000;
1053	} else
1054		*life = call.edx;
1055	return APM_SUCCESS;
1056}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1057
1058/**
1059 *	apm_engage_power_management	-	enable PM on a device
1060 *	@device: identity of device
1061 *	@enable: on/off
1062 *
1063 *	Activate or deactivate power management on either a specific device
1064 *	or the entire system (%APM_DEVICE_ALL).
1065 */
1066
1067static int apm_engage_power_management(u_short device, int enable)
1068{
1069	u32 eax;
1070	int err;
1071
1072	if ((enable == 0) && (device == APM_DEVICE_ALL)
1073	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1074		return APM_DISABLED;
1075	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1076				 &eax, &err))
1077		return err;
1078	if (device == APM_DEVICE_ALL) {
1079		if (enable)
1080			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1081		else
1082			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1083	}
1084	return APM_SUCCESS;
1085}
1086
1087#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1088
1089/**
1090 *	apm_console_blank	-	blank the display
1091 *	@blank: on/off
1092 *
1093 *	Attempt to blank the console, firstly by blanking just video device
1094 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1095 *	all video devices. Typically the BIOS will do laptop backlight and
1096 *	monitor powerdown for us.
1097 */
1098
1099static int apm_console_blank(int blank)
1100{
1101	int error = APM_NOT_ENGAGED; /* silence gcc */
1102	int i;
1103	u_short state;
1104	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1105
1106	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1107
1108	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1109		error = set_power_state(dev[i], state);
1110
1111		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1112			return 1;
1113
1114		if (error == APM_NOT_ENGAGED)
1115			break;
1116	}
1117
1118	if (error == APM_NOT_ENGAGED) {
1119		static int tried;
1120		int eng_error;
1121		if (tried++ == 0) {
1122			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1123			if (eng_error) {
1124				apm_error("set display", error);
1125				apm_error("engage interface", eng_error);
1126				return 0;
1127			} else
1128				return apm_console_blank(blank);
1129		}
1130	}
1131	apm_error("set display", error);
1132	return 0;
1133}
1134#endif
1135
1136static int queue_empty(struct apm_user *as)
1137{
1138	return as->event_head == as->event_tail;
1139}
1140
1141static apm_event_t get_queued_event(struct apm_user *as)
1142{
1143	if (++as->event_tail >= APM_MAX_EVENTS)
1144		as->event_tail = 0;
1145	return as->events[as->event_tail];
1146}
1147
1148static void queue_event(apm_event_t event, struct apm_user *sender)
1149{
1150	struct apm_user *as;
1151
1152	spin_lock(&user_list_lock);
1153	if (user_list == NULL)
1154		goto out;
1155	for (as = user_list; as != NULL; as = as->next) {
1156		if ((as == sender) || (!as->reader))
1157			continue;
1158		if (++as->event_head >= APM_MAX_EVENTS)
1159			as->event_head = 0;
1160
1161		if (as->event_head == as->event_tail) {
1162			static int notified;
1163
1164			if (notified++ == 0)
1165				pr_err("an event queue overflowed\n");
1166			if (++as->event_tail >= APM_MAX_EVENTS)
1167				as->event_tail = 0;
1168		}
1169		as->events[as->event_head] = event;
1170		if (!as->suser || !as->writer)
1171			continue;
1172		switch (event) {
1173		case APM_SYS_SUSPEND:
1174		case APM_USER_SUSPEND:
1175			as->suspends_pending++;
1176			suspends_pending++;
1177			break;
1178
1179		case APM_SYS_STANDBY:
1180		case APM_USER_STANDBY:
1181			as->standbys_pending++;
1182			standbys_pending++;
1183			break;
1184		}
1185	}
1186	wake_up_interruptible(&apm_waitqueue);
1187out:
1188	spin_unlock(&user_list_lock);
1189}
1190
1191static void reinit_timer(void)
1192{
1193#ifdef INIT_TIMER_AFTER_SUSPEND
1194	unsigned long flags;
1195
1196	raw_spin_lock_irqsave(&i8253_lock, flags);
1197	/* set the clock to HZ */
1198	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1199	udelay(10);
1200	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1201	udelay(10);
1202	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1203	udelay(10);
1204	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1205#endif
1206}
1207
1208static int suspend(int vetoable)
1209{
1210	int err;
1211	struct apm_user	*as;
1212
1213	dpm_suspend_start(PMSG_SUSPEND);
1214	dpm_suspend_end(PMSG_SUSPEND);
1215
1216	local_irq_disable();
1217	syscore_suspend();
1218
1219	local_irq_enable();
1220
1221	save_processor_state();
1222	err = set_system_power_state(APM_STATE_SUSPEND);
1223	ignore_normal_resume = 1;
1224	restore_processor_state();
1225
1226	local_irq_disable();
1227	reinit_timer();
1228
1229	if (err == APM_NO_ERROR)
1230		err = APM_SUCCESS;
1231	if (err != APM_SUCCESS)
1232		apm_error("suspend", err);
1233	err = (err == APM_SUCCESS) ? 0 : -EIO;
1234
1235	syscore_resume();
1236	local_irq_enable();
1237
1238	dpm_resume_start(PMSG_RESUME);
1239	dpm_resume_end(PMSG_RESUME);
1240
1241	queue_event(APM_NORMAL_RESUME, NULL);
1242	spin_lock(&user_list_lock);
1243	for (as = user_list; as != NULL; as = as->next) {
1244		as->suspend_wait = 0;
1245		as->suspend_result = err;
1246	}
1247	spin_unlock(&user_list_lock);
1248	wake_up_interruptible(&apm_suspend_waitqueue);
1249	return err;
1250}
1251
1252static void standby(void)
1253{
1254	int err;
1255
1256	dpm_suspend_end(PMSG_SUSPEND);
1257
1258	local_irq_disable();
1259	syscore_suspend();
1260	local_irq_enable();
1261
1262	err = set_system_power_state(APM_STATE_STANDBY);
1263	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1264		apm_error("standby", err);
1265
1266	local_irq_disable();
1267	syscore_resume();
1268	local_irq_enable();
1269
1270	dpm_resume_start(PMSG_RESUME);
1271}
1272
1273static apm_event_t get_event(void)
1274{
1275	int error;
1276	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1277	apm_eventinfo_t	info;
1278
1279	static int notified;
1280
1281	/* we don't use the eventinfo */
1282	error = apm_get_event(&event, &info);
1283	if (error == APM_SUCCESS)
1284		return event;
1285
1286	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1287		apm_error("get_event", error);
1288
1289	return 0;
1290}
1291
1292static void check_events(void)
1293{
1294	apm_event_t event;
1295	static unsigned long last_resume;
1296	static int ignore_bounce;
1297
1298	while ((event = get_event()) != 0) {
1299		if (debug) {
1300			if (event <= NR_APM_EVENT_NAME)
1301				printk(KERN_DEBUG "apm: received %s notify\n",
1302				       apm_event_name[event - 1]);
1303			else
1304				printk(KERN_DEBUG "apm: received unknown "
1305				       "event 0x%02x\n", event);
1306		}
1307		if (ignore_bounce
1308		    && (time_after(jiffies, last_resume + bounce_interval)))
1309			ignore_bounce = 0;
1310
1311		switch (event) {
1312		case APM_SYS_STANDBY:
1313		case APM_USER_STANDBY:
1314			queue_event(event, NULL);
1315			if (standbys_pending <= 0)
1316				standby();
1317			break;
1318
1319		case APM_USER_SUSPEND:
1320#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1321			if (apm_info.connection_version > 0x100)
1322				set_system_power_state(APM_STATE_REJECT);
1323			break;
1324#endif
1325		case APM_SYS_SUSPEND:
1326			if (ignore_bounce) {
1327				if (apm_info.connection_version > 0x100)
1328					set_system_power_state(APM_STATE_REJECT);
1329				break;
1330			}
1331			/*
1332			 * If we are already processing a SUSPEND,
1333			 * then further SUSPEND events from the BIOS
1334			 * will be ignored.  We also return here to
1335			 * cope with the fact that the Thinkpads keep
1336			 * sending a SUSPEND event until something else
1337			 * happens!
1338			 */
1339			if (ignore_sys_suspend)
1340				return;
1341			ignore_sys_suspend = 1;
1342			queue_event(event, NULL);
1343			if (suspends_pending <= 0)
1344				(void) suspend(1);
1345			break;
1346
1347		case APM_NORMAL_RESUME:
1348		case APM_CRITICAL_RESUME:
1349		case APM_STANDBY_RESUME:
1350			ignore_sys_suspend = 0;
1351			last_resume = jiffies;
1352			ignore_bounce = 1;
1353			if ((event != APM_NORMAL_RESUME)
1354			    || (ignore_normal_resume == 0)) {
1355				dpm_resume_end(PMSG_RESUME);
1356				queue_event(event, NULL);
1357			}
1358			ignore_normal_resume = 0;
1359			break;
1360
1361		case APM_CAPABILITY_CHANGE:
1362		case APM_LOW_BATTERY:
1363		case APM_POWER_STATUS_CHANGE:
1364			queue_event(event, NULL);
1365			/* If needed, notify drivers here */
1366			break;
1367
1368		case APM_UPDATE_TIME:
1369			break;
1370
1371		case APM_CRITICAL_SUSPEND:
1372			/*
1373			 * We are not allowed to reject a critical suspend.
1374			 */
1375			(void)suspend(0);
1376			break;
1377		}
1378	}
1379}
1380
1381static void apm_event_handler(void)
1382{
1383	static int pending_count = 4;
1384	int err;
1385
1386	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1387		if ((apm_info.connection_version > 0x100) &&
1388		    (pending_count-- <= 0)) {
1389			pending_count = 4;
1390			if (debug)
1391				printk(KERN_DEBUG "apm: setting state busy\n");
1392			err = set_system_power_state(APM_STATE_BUSY);
1393			if (err)
1394				apm_error("busy", err);
1395		}
1396	} else
1397		pending_count = 4;
1398	check_events();
1399}
1400
1401/*
1402 * This is the APM thread main loop.
1403 */
1404
1405static void apm_mainloop(void)
1406{
1407	DECLARE_WAITQUEUE(wait, current);
1408
1409	add_wait_queue(&apm_waitqueue, &wait);
1410	set_current_state(TASK_INTERRUPTIBLE);
1411	for (;;) {
1412		schedule_timeout(APM_CHECK_TIMEOUT);
1413		if (kthread_should_stop())
1414			break;
1415		/*
1416		 * Ok, check all events, check for idle (and mark us sleeping
1417		 * so as not to count towards the load average)..
1418		 */
1419		set_current_state(TASK_INTERRUPTIBLE);
1420		apm_event_handler();
1421	}
1422	remove_wait_queue(&apm_waitqueue, &wait);
1423}
1424
1425static int check_apm_user(struct apm_user *as, const char *func)
1426{
1427	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1428		pr_err("%s passed bad filp\n", func);
1429		return 1;
1430	}
1431	return 0;
1432}
1433
1434static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1435{
1436	struct apm_user *as;
1437	int i;
1438	apm_event_t event;
1439
1440	as = fp->private_data;
1441	if (check_apm_user(as, "read"))
1442		return -EIO;
1443	if ((int)count < sizeof(apm_event_t))
1444		return -EINVAL;
1445	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1446		return -EAGAIN;
1447	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1448	i = count;
1449	while ((i >= sizeof(event)) && !queue_empty(as)) {
1450		event = get_queued_event(as);
1451		if (copy_to_user(buf, &event, sizeof(event))) {
1452			if (i < count)
1453				break;
1454			return -EFAULT;
1455		}
1456		switch (event) {
1457		case APM_SYS_SUSPEND:
1458		case APM_USER_SUSPEND:
1459			as->suspends_read++;
1460			break;
1461
1462		case APM_SYS_STANDBY:
1463		case APM_USER_STANDBY:
1464			as->standbys_read++;
1465			break;
1466		}
1467		buf += sizeof(event);
1468		i -= sizeof(event);
1469	}
1470	if (i < count)
1471		return count - i;
1472	if (signal_pending(current))
1473		return -ERESTARTSYS;
1474	return 0;
1475}
1476
1477static __poll_t do_poll(struct file *fp, poll_table *wait)
1478{
1479	struct apm_user *as;
1480
1481	as = fp->private_data;
1482	if (check_apm_user(as, "poll"))
1483		return 0;
1484	poll_wait(fp, &apm_waitqueue, wait);
1485	if (!queue_empty(as))
1486		return EPOLLIN | EPOLLRDNORM;
1487	return 0;
1488}
1489
1490static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1491{
1492	struct apm_user *as;
1493	int ret;
1494
1495	as = filp->private_data;
1496	if (check_apm_user(as, "ioctl"))
1497		return -EIO;
1498	if (!as->suser || !as->writer)
1499		return -EPERM;
1500	switch (cmd) {
1501	case APM_IOC_STANDBY:
1502		mutex_lock(&apm_mutex);
1503		if (as->standbys_read > 0) {
1504			as->standbys_read--;
1505			as->standbys_pending--;
1506			standbys_pending--;
1507		} else
1508			queue_event(APM_USER_STANDBY, as);
1509		if (standbys_pending <= 0)
1510			standby();
1511		mutex_unlock(&apm_mutex);
1512		break;
1513	case APM_IOC_SUSPEND:
1514		mutex_lock(&apm_mutex);
1515		if (as->suspends_read > 0) {
1516			as->suspends_read--;
1517			as->suspends_pending--;
1518			suspends_pending--;
1519		} else
1520			queue_event(APM_USER_SUSPEND, as);
1521		if (suspends_pending <= 0) {
1522			ret = suspend(1);
1523			mutex_unlock(&apm_mutex);
1524		} else {
1525			as->suspend_wait = 1;
1526			mutex_unlock(&apm_mutex);
1527			wait_event_interruptible(apm_suspend_waitqueue,
1528					as->suspend_wait == 0);
1529			ret = as->suspend_result;
1530		}
1531		return ret;
1532	default:
1533		return -ENOTTY;
1534	}
1535	return 0;
1536}
1537
1538static int do_release(struct inode *inode, struct file *filp)
1539{
1540	struct apm_user *as;
1541
1542	as = filp->private_data;
1543	if (check_apm_user(as, "release"))
1544		return 0;
1545	filp->private_data = NULL;
1546	if (as->standbys_pending > 0) {
1547		standbys_pending -= as->standbys_pending;
1548		if (standbys_pending <= 0)
1549			standby();
1550	}
1551	if (as->suspends_pending > 0) {
1552		suspends_pending -= as->suspends_pending;
1553		if (suspends_pending <= 0)
1554			(void) suspend(1);
1555	}
1556	spin_lock(&user_list_lock);
1557	if (user_list == as)
1558		user_list = as->next;
1559	else {
1560		struct apm_user *as1;
1561
1562		for (as1 = user_list;
1563		     (as1 != NULL) && (as1->next != as);
1564		     as1 = as1->next)
1565			;
1566		if (as1 == NULL)
1567			pr_err("filp not in user list\n");
1568		else
1569			as1->next = as->next;
1570	}
1571	spin_unlock(&user_list_lock);
1572	kfree(as);
1573	return 0;
1574}
1575
1576static int do_open(struct inode *inode, struct file *filp)
1577{
1578	struct apm_user *as;
1579
1580	as = kmalloc(sizeof(*as), GFP_KERNEL);
1581	if (as == NULL)
1582		return -ENOMEM;
1583
1584	as->magic = APM_BIOS_MAGIC;
1585	as->event_tail = as->event_head = 0;
1586	as->suspends_pending = as->standbys_pending = 0;
1587	as->suspends_read = as->standbys_read = 0;
1588	/*
1589	 * XXX - this is a tiny bit broken, when we consider BSD
1590	 * process accounting. If the device is opened by root, we
1591	 * instantly flag that we used superuser privs. Who knows,
1592	 * we might close the device immediately without doing a
1593	 * privileged operation -- cevans
1594	 */
1595	as->suser = capable(CAP_SYS_ADMIN);
1596	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1597	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1598	spin_lock(&user_list_lock);
1599	as->next = user_list;
1600	user_list = as;
1601	spin_unlock(&user_list_lock);
1602	filp->private_data = as;
1603	return 0;
1604}
1605
1606#ifdef CONFIG_PROC_FS
1607static int proc_apm_show(struct seq_file *m, void *v)
1608{
1609	unsigned short	bx;
1610	unsigned short	cx;
1611	unsigned short	dx;
1612	int		error;
1613	unsigned short  ac_line_status = 0xff;
1614	unsigned short  battery_status = 0xff;
1615	unsigned short  battery_flag   = 0xff;
1616	int		percentage     = -1;
1617	int             time_units     = -1;
1618	char            *units         = "?";
1619
1620	if ((num_online_cpus() == 1) &&
1621	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1622		ac_line_status = (bx >> 8) & 0xff;
1623		battery_status = bx & 0xff;
1624		if ((cx & 0xff) != 0xff)
1625			percentage = cx & 0xff;
1626
1627		if (apm_info.connection_version > 0x100) {
1628			battery_flag = (cx >> 8) & 0xff;
1629			if (dx != 0xffff) {
1630				units = (dx & 0x8000) ? "min" : "sec";
1631				time_units = dx & 0x7fff;
1632			}
1633		}
1634	}
1635	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1636	   from the Get Power Status (0x0a) call unless otherwise noted.
1637
1638	   0) Linux driver version (this will change if format changes)
1639	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1640	   2) APM flags from APM Installation Check (0x00):
1641	      bit 0: APM_16_BIT_SUPPORT
1642	      bit 1: APM_32_BIT_SUPPORT
1643	      bit 2: APM_IDLE_SLOWS_CLOCK
1644	      bit 3: APM_BIOS_DISABLED
1645	      bit 4: APM_BIOS_DISENGAGED
1646	   3) AC line status
1647	      0x00: Off-line
1648	      0x01: On-line
1649	      0x02: On backup power (BIOS >= 1.1 only)
1650	      0xff: Unknown
1651	   4) Battery status
1652	      0x00: High
1653	      0x01: Low
1654	      0x02: Critical
1655	      0x03: Charging
1656	      0x04: Selected battery not present (BIOS >= 1.2 only)
1657	      0xff: Unknown
1658	   5) Battery flag
1659	      bit 0: High
1660	      bit 1: Low
1661	      bit 2: Critical
1662	      bit 3: Charging
1663	      bit 7: No system battery
1664	      0xff: Unknown
1665	   6) Remaining battery life (percentage of charge):
1666	      0-100: valid
1667	      -1: Unknown
1668	   7) Remaining battery life (time units):
1669	      Number of remaining minutes or seconds
1670	      -1: Unknown
1671	   8) min = minutes; sec = seconds */
1672
1673	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1674		   driver_version,
1675		   (apm_info.bios.version >> 8) & 0xff,
1676		   apm_info.bios.version & 0xff,
1677		   apm_info.bios.flags,
1678		   ac_line_status,
1679		   battery_status,
1680		   battery_flag,
1681		   percentage,
1682		   time_units,
1683		   units);
1684	return 0;
1685}
1686#endif
1687
1688static int apm(void *unused)
1689{
1690	unsigned short	bx;
1691	unsigned short	cx;
1692	unsigned short	dx;
1693	int		error;
1694	char 		*power_stat;
1695	char 		*bat_stat;
1696
1697	/* 2002/08/01 - WT
1698	 * This is to avoid random crashes at boot time during initialization
1699	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1700	 * Some bioses don't like being called from CPU != 0.
1701	 * Method suggested by Ingo Molnar.
1702	 */
1703	set_cpus_allowed_ptr(current, cpumask_of(0));
1704	BUG_ON(smp_processor_id() != 0);
1705
1706	if (apm_info.connection_version == 0) {
1707		apm_info.connection_version = apm_info.bios.version;
1708		if (apm_info.connection_version > 0x100) {
1709			/*
1710			 * We only support BIOSs up to version 1.2
1711			 */
1712			if (apm_info.connection_version > 0x0102)
1713				apm_info.connection_version = 0x0102;
1714			error = apm_driver_version(&apm_info.connection_version);
1715			if (error != APM_SUCCESS) {
1716				apm_error("driver version", error);
1717				/* Fall back to an APM 1.0 connection. */
1718				apm_info.connection_version = 0x100;
1719			}
1720		}
1721	}
1722
1723	if (debug)
1724		printk(KERN_INFO "apm: Connection version %d.%d\n",
1725			(apm_info.connection_version >> 8) & 0xff,
1726			apm_info.connection_version & 0xff);
1727
1728#ifdef CONFIG_APM_DO_ENABLE
1729	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1730		/*
1731		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1732		 * is booted with PM disabled but not in the docking station.
1733		 * Unfortunate ...
1734		 */
1735		error = apm_enable_power_management(1);
1736		if (error) {
1737			apm_error("enable power management", error);
1738			return -1;
1739		}
1740	}
1741#endif
1742
1743	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1744	    && (apm_info.connection_version > 0x0100)) {
1745		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1746		if (error) {
1747			apm_error("engage power management", error);
1748			return -1;
1749		}
1750	}
1751
1752	if (debug && (num_online_cpus() == 1 || smp)) {
1753		error = apm_get_power_status(&bx, &cx, &dx);
1754		if (error)
1755			printk(KERN_INFO "apm: power status not available\n");
1756		else {
1757			switch ((bx >> 8) & 0xff) {
1758			case 0:
1759				power_stat = "off line";
1760				break;
1761			case 1:
1762				power_stat = "on line";
1763				break;
1764			case 2:
1765				power_stat = "on backup power";
1766				break;
1767			default:
1768				power_stat = "unknown";
1769				break;
1770			}
1771			switch (bx & 0xff) {
1772			case 0:
1773				bat_stat = "high";
1774				break;
1775			case 1:
1776				bat_stat = "low";
1777				break;
1778			case 2:
1779				bat_stat = "critical";
1780				break;
1781			case 3:
1782				bat_stat = "charging";
1783				break;
1784			default:
1785				bat_stat = "unknown";
1786				break;
1787			}
1788			printk(KERN_INFO
1789			       "apm: AC %s, battery status %s, battery life ",
1790			       power_stat, bat_stat);
1791			if ((cx & 0xff) == 0xff)
1792				printk("unknown\n");
1793			else
1794				printk("%d%%\n", cx & 0xff);
1795			if (apm_info.connection_version > 0x100) {
1796				printk(KERN_INFO
1797				       "apm: battery flag 0x%02x, battery life ",
1798				       (cx >> 8) & 0xff);
1799				if (dx == 0xffff)
1800					printk("unknown\n");
1801				else
1802					printk("%d %s\n", dx & 0x7fff,
1803					       (dx & 0x8000) ?
1804					       "minutes" : "seconds");
1805			}
1806		}
1807	}
1808
1809	/* Install our power off handler.. */
1810	if (power_off)
1811		pm_power_off = apm_power_off;
1812
1813	if (num_online_cpus() == 1 || smp) {
1814#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1815		console_blank_hook = apm_console_blank;
1816#endif
1817		apm_mainloop();
1818#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1819		console_blank_hook = NULL;
1820#endif
1821	}
1822
1823	return 0;
1824}
1825
1826#ifndef MODULE
1827static int __init apm_setup(char *str)
1828{
1829	int invert;
1830
1831	while ((str != NULL) && (*str != '\0')) {
1832		if (strncmp(str, "off", 3) == 0)
1833			apm_disabled = 1;
1834		if (strncmp(str, "on", 2) == 0)
1835			apm_disabled = 0;
1836		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1837		    (strncmp(str, "bounce_interval=", 16) == 0))
1838			bounce_interval = simple_strtol(str + 16, NULL, 0);
1839		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1840		    (strncmp(str, "idle_threshold=", 15) == 0))
1841			idle_threshold = simple_strtol(str + 15, NULL, 0);
1842		if ((strncmp(str, "idle-period=", 12) == 0) ||
1843		    (strncmp(str, "idle_period=", 12) == 0))
1844			idle_period = simple_strtol(str + 12, NULL, 0);
1845		invert = (strncmp(str, "no-", 3) == 0) ||
1846			(strncmp(str, "no_", 3) == 0);
1847		if (invert)
1848			str += 3;
1849		if (strncmp(str, "debug", 5) == 0)
1850			debug = !invert;
1851		if ((strncmp(str, "power-off", 9) == 0) ||
1852		    (strncmp(str, "power_off", 9) == 0))
1853			power_off = !invert;
1854		if (strncmp(str, "smp", 3) == 0) {
1855			smp = !invert;
1856			idle_threshold = 100;
1857		}
1858		if ((strncmp(str, "allow-ints", 10) == 0) ||
1859		    (strncmp(str, "allow_ints", 10) == 0))
1860			apm_info.allow_ints = !invert;
1861		if ((strncmp(str, "broken-psr", 10) == 0) ||
1862		    (strncmp(str, "broken_psr", 10) == 0))
1863			apm_info.get_power_status_broken = !invert;
1864		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1865		    (strncmp(str, "realmode_power_off", 18) == 0))
1866			apm_info.realmode_power_off = !invert;
1867		str = strchr(str, ',');
1868		if (str != NULL)
1869			str += strspn(str, ", \t");
1870	}
1871	return 1;
1872}
1873
1874__setup("apm=", apm_setup);
1875#endif
1876
1877static const struct file_operations apm_bios_fops = {
1878	.owner		= THIS_MODULE,
1879	.read		= do_read,
1880	.poll		= do_poll,
1881	.unlocked_ioctl	= do_ioctl,
1882	.open		= do_open,
1883	.release	= do_release,
1884	.llseek		= noop_llseek,
1885};
1886
1887static struct miscdevice apm_device = {
1888	APM_MINOR_DEV,
1889	"apm_bios",
1890	&apm_bios_fops
1891};
1892
1893
1894/* Simple "print if true" callback */
1895static int __init print_if_true(const struct dmi_system_id *d)
1896{
1897	printk("%s\n", d->ident);
1898	return 0;
1899}
1900
1901/*
1902 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1903 * disabled before the suspend. Linux used to get terribly confused by that.
1904 */
1905static int __init broken_ps2_resume(const struct dmi_system_id *d)
1906{
1907	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1908	       "workaround hopefully not needed.\n", d->ident);
1909	return 0;
1910}
1911
1912/* Some bioses have a broken protected mode poweroff and need to use realmode */
1913static int __init set_realmode_power_off(const struct dmi_system_id *d)
1914{
1915	if (apm_info.realmode_power_off == 0) {
1916		apm_info.realmode_power_off = 1;
1917		printk(KERN_INFO "%s bios detected. "
1918		       "Using realmode poweroff only.\n", d->ident);
1919	}
1920	return 0;
1921}
1922
1923/* Some laptops require interrupts to be enabled during APM calls */
1924static int __init set_apm_ints(const struct dmi_system_id *d)
1925{
1926	if (apm_info.allow_ints == 0) {
1927		apm_info.allow_ints = 1;
1928		printk(KERN_INFO "%s machine detected. "
1929		       "Enabling interrupts during APM calls.\n", d->ident);
1930	}
1931	return 0;
1932}
1933
1934/* Some APM bioses corrupt memory or just plain do not work */
1935static int __init apm_is_horked(const struct dmi_system_id *d)
1936{
1937	if (apm_info.disabled == 0) {
1938		apm_info.disabled = 1;
1939		printk(KERN_INFO "%s machine detected. "
1940		       "Disabling APM.\n", d->ident);
1941	}
1942	return 0;
1943}
1944
1945static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1946{
1947	if (apm_info.disabled == 0) {
1948		apm_info.disabled = 1;
1949		printk(KERN_INFO "%s machine detected. "
1950		       "Disabling APM.\n", d->ident);
1951		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1952		printk(KERN_INFO "download from support.intel.com\n");
1953	}
1954	return 0;
1955}
1956
1957/* Some APM bioses hang on APM idle calls */
1958static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1959{
1960	if (apm_info.forbid_idle == 0) {
1961		apm_info.forbid_idle = 1;
1962		printk(KERN_INFO "%s machine detected. "
1963		       "Disabling APM idle calls.\n", d->ident);
1964	}
1965	return 0;
1966}
1967
1968/*
1969 *  Check for clue free BIOS implementations who use
1970 *  the following QA technique
1971 *
1972 *      [ Write BIOS Code ]<------
1973 *               |                ^
1974 *      < Does it Compile >----N--
1975 *               |Y               ^
1976 *	< Does it Boot Win98 >-N--
1977 *               |Y
1978 *           [Ship It]
1979 *
1980 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
1981 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
1982 */
1983static int __init broken_apm_power(const struct dmi_system_id *d)
1984{
1985	apm_info.get_power_status_broken = 1;
1986	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
1987	       "disabling power status reporting.\n");
1988	return 0;
1989}
1990
1991/*
1992 * This bios swaps the APM minute reporting bytes over (Many sony laptops
1993 * have this problem).
1994 */
1995static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
1996{
1997	apm_info.get_power_status_swabinminutes = 1;
1998	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
1999	       "in minutes and wrong byte order.\n");
2000	return 0;
2001}
2002
2003static const struct dmi_system_id apm_dmi_table[] __initconst = {
2004	{
2005		print_if_true,
2006		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2007		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2008			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2009	},
2010	{	/* Handle problems with APM on the C600 */
2011		broken_ps2_resume, "Dell Latitude C600",
2012		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2013			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2014	},
2015	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2016		set_apm_ints, "Dell Latitude",
2017		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2018			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2019	},
2020	{	/* APM crashes */
2021		apm_is_horked, "Dell Inspiron 2500",
2022		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2023			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2024			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2025			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2026	},
2027	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2028		set_apm_ints, "Dell Inspiron", {
2029			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2030			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2031	},
2032	{	/* Handle problems with APM on Inspiron 5000e */
2033		broken_apm_power, "Dell Inspiron 5000e",
2034		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2035			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2036			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2037	},
2038	{	/* Handle problems with APM on Inspiron 2500 */
2039		broken_apm_power, "Dell Inspiron 2500",
2040		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2041			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2042			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2043	},
2044	{	/* APM crashes */
2045		apm_is_horked, "Dell Dimension 4100",
2046		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2047			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2048			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2049			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2050	},
2051	{	/* Allow interrupts during suspend on Compaq Laptops*/
2052		set_apm_ints, "Compaq 12XL125",
2053		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2054			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2055			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2056			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2057	},
2058	{	/* Allow interrupts during APM or the clock goes slow */
2059		set_apm_ints, "ASUSTeK",
2060		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2061			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2062	},
2063	{	/* APM blows on shutdown */
2064		apm_is_horked, "ABIT KX7-333[R]",
2065		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2066			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2067	},
2068	{	/* APM crashes */
2069		apm_is_horked, "Trigem Delhi3",
2070		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2071			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2072	},
2073	{	/* APM crashes */
2074		apm_is_horked, "Fujitsu-Siemens",
2075		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2076			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2077	},
2078	{	/* APM crashes */
2079		apm_is_horked_d850md, "Intel D850MD",
2080		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2081			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2082	},
2083	{	/* APM crashes */
2084		apm_is_horked, "Intel D810EMO",
2085		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2086			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2087	},
2088	{	/* APM crashes */
2089		apm_is_horked, "Dell XPS-Z",
2090		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2091			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2092			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2093	},
2094	{	/* APM crashes */
2095		apm_is_horked, "Sharp PC-PJ/AX",
2096		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2097			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2098			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2099			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2100	},
2101	{	/* APM crashes */
2102		apm_is_horked, "Dell Inspiron 2500",
2103		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2104			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2105			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2106			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2107	},
2108	{	/* APM idle hangs */
2109		apm_likes_to_melt, "Jabil AMD",
2110		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2111			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2112	},
2113	{	/* APM idle hangs */
2114		apm_likes_to_melt, "AMI Bios",
2115		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2116			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2117	},
2118	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2119		swab_apm_power_in_minutes, "Sony VAIO",
2120		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2121			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2122			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2123	},
2124	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2125		swab_apm_power_in_minutes, "Sony VAIO",
2126		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2127			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2128			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2129	},
2130	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2131		swab_apm_power_in_minutes, "Sony VAIO",
2132		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2133			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2134			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2135	},
2136	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2137		swab_apm_power_in_minutes, "Sony VAIO",
2138		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2139			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2140			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2141	},
2142	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2143		swab_apm_power_in_minutes, "Sony VAIO",
2144		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2145			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2146			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2147	},
2148	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2149		swab_apm_power_in_minutes, "Sony VAIO",
2150		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2151			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2152			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2153	},
2154	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2155		swab_apm_power_in_minutes, "Sony VAIO",
2156		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2157			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2158			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2159	},
2160	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2161		swab_apm_power_in_minutes, "Sony VAIO",
2162		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2163			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2164			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2165	},
2166	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2167		swab_apm_power_in_minutes, "Sony VAIO",
2168		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2169			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2170			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2171	},
2172	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2173		swab_apm_power_in_minutes, "Sony VAIO",
2174		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2175			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2176			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2177	},
2178
2179	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2180		swab_apm_power_in_minutes, "Sony VAIO",
2181		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2182			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2183			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2184	},
2185	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2186		swab_apm_power_in_minutes, "Sony VAIO",
2187		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2188			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2189			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2190	},
2191	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2192		swab_apm_power_in_minutes, "Sony VAIO",
2193		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2194			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2195			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2196	},
2197	{	/* broken PM poweroff bios */
2198		set_realmode_power_off, "Award Software v4.60 PGMA",
2199		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2200			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2201			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2202	},
2203
2204	/* Generic per vendor APM settings  */
2205
2206	{	/* Allow interrupts during suspend on IBM laptops */
2207		set_apm_ints, "IBM",
2208		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2209	},
2210
2211	{ }
2212};
2213
2214/*
2215 * Just start the APM thread. We do NOT want to do APM BIOS
2216 * calls from anything but the APM thread, if for no other reason
2217 * than the fact that we don't trust the APM BIOS. This way,
2218 * most common APM BIOS problems that lead to protection errors
2219 * etc will have at least some level of being contained...
2220 *
2221 * In short, if something bad happens, at least we have a choice
2222 * of just killing the apm thread..
2223 */
2224static int __init apm_init(void)
2225{
2226	struct desc_struct *gdt;
2227	int err;
2228
2229	dmi_check_system(apm_dmi_table);
2230
2231	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2232		printk(KERN_INFO "apm: BIOS not found.\n");
2233		return -ENODEV;
2234	}
2235	printk(KERN_INFO
2236	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2237	       ((apm_info.bios.version >> 8) & 0xff),
2238	       (apm_info.bios.version & 0xff),
2239	       apm_info.bios.flags,
2240	       driver_version);
2241	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2242		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2243		return -ENODEV;
2244	}
2245
2246	if (allow_ints)
2247		apm_info.allow_ints = 1;
2248	if (broken_psr)
2249		apm_info.get_power_status_broken = 1;
2250	if (realmode_power_off)
2251		apm_info.realmode_power_off = 1;
2252	/* User can override, but default is to trust DMI */
2253	if (apm_disabled != -1)
2254		apm_info.disabled = apm_disabled;
2255
2256	/*
2257	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2258	 * but is reportedly a 1.0 BIOS.
2259	 */
2260	if (apm_info.bios.version == 0x001)
2261		apm_info.bios.version = 0x100;
2262
2263	/* BIOS < 1.2 doesn't set cseg_16_len */
2264	if (apm_info.bios.version < 0x102)
2265		apm_info.bios.cseg_16_len = 0; /* 64k */
2266
2267	if (debug) {
2268		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2269			apm_info.bios.cseg, apm_info.bios.offset,
2270			apm_info.bios.cseg_16, apm_info.bios.dseg);
2271		if (apm_info.bios.version > 0x100)
2272			printk(" cseg len %x, dseg len %x",
2273				apm_info.bios.cseg_len,
2274				apm_info.bios.dseg_len);
2275		if (apm_info.bios.version > 0x101)
2276			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2277		printk("\n");
2278	}
2279
2280	if (apm_info.disabled) {
2281		pr_notice("disabled on user request.\n");
2282		return -ENODEV;
2283	}
2284	if ((num_online_cpus() > 1) && !power_off && !smp) {
2285		pr_notice("disabled - APM is not SMP safe.\n");
2286		apm_info.disabled = 1;
2287		return -ENODEV;
2288	}
2289	if (!acpi_disabled) {
2290		pr_notice("overridden by ACPI.\n");
2291		apm_info.disabled = 1;
2292		return -ENODEV;
2293	}
2294
2295	/*
2296	 * Set up the long jump entry point to the APM BIOS, which is called
2297	 * from inline assembly.
2298	 */
2299	apm_bios_entry.offset = apm_info.bios.offset;
2300	apm_bios_entry.segment = APM_CS;
2301
2302	/*
2303	 * The APM 1.1 BIOS is supposed to provide limit information that it
2304	 * recognizes.  Many machines do this correctly, but many others do
2305	 * not restrict themselves to their claimed limit.  When this happens,
2306	 * they will cause a segmentation violation in the kernel at boot time.
2307	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2308	 *
2309	 * Note we only set APM segments on CPU zero, since we pin the APM
2310	 * code to that CPU.
2311	 */
2312	gdt = get_cpu_gdt_rw(0);
2313	set_desc_base(&gdt[APM_CS >> 3],
2314		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2315	set_desc_base(&gdt[APM_CS_16 >> 3],
2316		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2317	set_desc_base(&gdt[APM_DS >> 3],
2318		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2319
2320	proc_create_single("apm", 0, NULL, proc_apm_show);
2321
2322	kapmd_task = kthread_create(apm, NULL, "kapmd");
2323	if (IS_ERR(kapmd_task)) {
2324		pr_err("disabled - Unable to start kernel thread\n");
2325		err = PTR_ERR(kapmd_task);
2326		kapmd_task = NULL;
2327		remove_proc_entry("apm", NULL);
2328		return err;
2329	}
2330	wake_up_process(kapmd_task);
2331
2332	if (num_online_cpus() > 1 && !smp) {
2333		printk(KERN_NOTICE
2334		       "apm: disabled - APM is not SMP safe (power off active).\n");
2335		return 0;
2336	}
2337
2338	/*
2339	 * Note we don't actually care if the misc_device cannot be registered.
2340	 * this driver can do its job without it, even if userspace can't
2341	 * control it.  just log the error
2342	 */
2343	if (misc_register(&apm_device))
2344		printk(KERN_WARNING "apm: Could not register misc device.\n");
2345
2346	if (HZ != 100)
2347		idle_period = (idle_period * HZ) / 100;
2348	if (idle_threshold < 100) {
2349		cpuidle_poll_state_init(&apm_idle_driver);
2350		if (!cpuidle_register_driver(&apm_idle_driver))
2351			if (cpuidle_register_device(&apm_cpuidle_device))
2352				cpuidle_unregister_driver(&apm_idle_driver);
2353	}
2354
2355	return 0;
2356}
2357
2358static void __exit apm_exit(void)
2359{
2360	int error;
2361
2362	cpuidle_unregister_device(&apm_cpuidle_device);
2363	cpuidle_unregister_driver(&apm_idle_driver);
2364
2365	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2366	    && (apm_info.connection_version > 0x0100)) {
2367		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2368		if (error)
2369			apm_error("disengage power management", error);
2370	}
2371	misc_deregister(&apm_device);
2372	remove_proc_entry("apm", NULL);
2373	if (power_off)
2374		pm_power_off = NULL;
2375	if (kapmd_task) {
2376		kthread_stop(kapmd_task);
2377		kapmd_task = NULL;
2378	}
2379}
2380
2381module_init(apm_init);
2382module_exit(apm_exit);
2383
2384MODULE_AUTHOR("Stephen Rothwell");
2385MODULE_DESCRIPTION("Advanced Power Management");
2386MODULE_LICENSE("GPL");
2387module_param(debug, bool, 0644);
2388MODULE_PARM_DESC(debug, "Enable debug mode");
2389module_param(power_off, bool, 0444);
2390MODULE_PARM_DESC(power_off, "Enable power off");
2391module_param(bounce_interval, int, 0444);
2392MODULE_PARM_DESC(bounce_interval,
2393		"Set the number of ticks to ignore suspend bounces");
2394module_param(allow_ints, bool, 0444);
2395MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2396module_param(broken_psr, bool, 0444);
2397MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2398module_param(realmode_power_off, bool, 0444);
2399MODULE_PARM_DESC(realmode_power_off,
2400		"Switch to real mode before powering off");
2401module_param(idle_threshold, int, 0444);
2402MODULE_PARM_DESC(idle_threshold,
2403	"System idle percentage above which to make APM BIOS idle calls");
2404module_param(idle_period, int, 0444);
2405MODULE_PARM_DESC(idle_period,
2406	"Period (in sec/100) over which to calculate the idle percentage");
2407module_param(smp, bool, 0444);
2408MODULE_PARM_DESC(smp,
2409	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2410MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);