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v3.15
   1/* -*- linux-c -*-
   2 * APM BIOS driver for Linux
   3 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   4 *
   5 * Initial development of this driver was funded by NEC Australia P/L
   6 *	and NEC Corporation
   7 *
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms of the GNU General Public License as published by the
  10 * Free Software Foundation; either version 2, or (at your option) any
  11 * later version.
  12 *
  13 * This program is distributed in the hope that it will be useful, but
  14 * WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 * General Public License for more details.
  17 *
  18 * October 1995, Rik Faith (faith@cs.unc.edu):
  19 *    Minor enhancements and updates (to the patch set) for 1.3.x
  20 *    Documentation
  21 * January 1996, Rik Faith (faith@cs.unc.edu):
  22 *    Make /proc/apm easy to format (bump driver version)
  23 * March 1996, Rik Faith (faith@cs.unc.edu):
  24 *    Prohibit APM BIOS calls unless apm_enabled.
  25 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  26 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  27 *    Version 1.0 and 1.1
  28 * May 1996, Version 1.2
  29 * Feb 1998, Version 1.3
  30 * Feb 1998, Version 1.4
  31 * Aug 1998, Version 1.5
  32 * Sep 1998, Version 1.6
  33 * Nov 1998, Version 1.7
  34 * Jan 1999, Version 1.8
  35 * Jan 1999, Version 1.9
  36 * Oct 1999, Version 1.10
  37 * Nov 1999, Version 1.11
  38 * Jan 2000, Version 1.12
  39 * Feb 2000, Version 1.13
  40 * Nov 2000, Version 1.14
  41 * Oct 2001, Version 1.15
  42 * Jan 2002, Version 1.16
  43 * Oct 2002, Version 1.16ac
  44 *
  45 * History:
  46 *    0.6b: first version in official kernel, Linux 1.3.46
  47 *    0.7: changed /proc/apm format, Linux 1.3.58
  48 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  49 *    0.9: only call bios if bios is present, Linux 1.3.72
  50 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  51 *         Linux 1.3.85
  52 *    1.1: support user-space standby and suspend, power off after system
  53 *         halted, Linux 1.3.98
  54 *    1.2: When resetting RTC after resume, take care so that the time
  55 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  56 *         <jtoth@princeton.edu>); improve interaction between
  57 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  58 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  59 *	   levels to the printk calls. APM is not defined for SMP machines.
  60 *         The new replacement for it is, but Linux doesn't yet support this.
  61 *         Alan Cox Linux 2.1.55
  62 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  63 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  64 *         Dean Gaudet <dgaudet@arctic.org>.
  65 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  66 *    1.5: Fix segment register reloading (in case of bad segments saved
  67 *         across BIOS call).
  68 *         Stephen Rothwell
  69 *    1.6: Cope with compiler/assembler differences.
  70 *         Only try to turn off the first display device.
  71 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  72 *                   <echter@informatik.uni-rostock.de>
  73 *         Stephen Rothwell
  74 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  75 *         to reflect current state of APM BIOS.
  76 *         Chris Rankin <rankinc@bellsouth.net>
  77 *         Reset interrupt 0 timer to 100Hz after suspend
  78 *         Chad Miller <cmiller@surfsouth.com>
  79 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  80 *         Richard Gooch <rgooch@atnf.csiro.au>
  81 *         Allow boot time disabling of APM
  82 *         Make boot messages far less verbose by default
  83 *         Make asm safer
  84 *         Stephen Rothwell
  85 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  86 *         Richard Gooch <rgooch@atnf.csiro.au>
  87 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  88 *         remove dependency on CONFIG_PROC_FS
  89 *         Stephen Rothwell
  90 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  91 *         Try to cope with BIOS's that need to have all display
  92 *         devices blanked and not just the first one.
  93 *         Ross Paterson <ross@soi.city.ac.uk>
  94 *         Fix segment limit setting it has always been wrong as
  95 *         the segments needed to have byte granularity.
  96 *         Mark a few things __init.
  97 *         Add hack to allow power off of SMP systems by popular request.
  98 *         Use CONFIG_SMP instead of __SMP__
  99 *         Ignore BOUNCES for three seconds.
 100 *         Stephen Rothwell
 101 *   1.10: Fix for Thinkpad return code.
 102 *         Merge 2.2 and 2.3 drivers.
 103 *         Remove APM dependencies in arch/i386/kernel/process.c
 104 *         Remove APM dependencies in drivers/char/sysrq.c
 105 *         Reset time across standby.
 106 *         Allow more inititialisation on SMP.
 107 *         Remove CONFIG_APM_POWER_OFF and make it boot time
 108 *         configurable (default on).
 109 *         Make debug only a boot time parameter (remove APM_DEBUG).
 110 *         Try to blank all devices on any error.
 111 *   1.11: Remove APM dependencies in drivers/char/console.c
 112 *         Check nr_running to detect if we are idle (from
 113 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 114 *         Fix for bioses that don't zero the top part of the
 115 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 116 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 117 *         Real mode power off patch (Walter Hofmann
 118 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 119 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 120 *         the code away anyway (smp_num_cpus == 1 in UP)
 121 *         noted by Artur Skawina <skawina@geocities.com>.
 122 *         Make power off under SMP work again.
 123 *         Fix thinko with initial engaging of BIOS.
 124 *         Make sure power off only happens on CPU 0
 125 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 126 *         Do error notification to user mode if BIOS calls fail.
 127 *         Move entrypoint offset fix to ...boot/setup.S
 128 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 129 *         Remove smp-power-off. SMP users must now specify
 130 *         "apm=power-off" on the kernel command line. Suggested
 131 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 132 *         <alan@lxorguk.ukuu.org.uk>.
 133 *         Register the /proc/apm entry even on SMP so that
 134 *         scripts that check for it before doing power off
 135 *         work (Jim Avera <jima@hal.com>).
 136 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 137 *         <andy_henroid@yahoo.com>).
 138 *         Modularize the code.
 139 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 140 *         is now the way life works).
 141 *         Fix thinko in suspend() (wrong return).
 142 *         Notify drivers on critical suspend.
 143 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 144 *         modified by sfr).
 145 *         Disable interrupts while we are suspended (Andy Henroid
 146 *         <andy_henroid@yahoo.com> fixed by sfr).
 147 *         Make power off work on SMP again (Tony Hoyle
 148 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 149 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 150 *         interval is now configurable.
 151 *   1.14: Make connection version persist across module unload/load.
 152 *         Enable and engage power management earlier.
 153 *         Disengage power management on module unload.
 154 *         Changed to use the sysrq-register hack for registering the
 155 *         power off function called by magic sysrq based upon discussions
 156 *         in irc://irc.openprojects.net/#kernelnewbies
 157 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 158 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 159 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 160 *         Work around byte swap bug in one of the Vaio's BIOS's
 161 *         (Marc Boucher <marc@mbsi.ca>).
 162 *         Exposed the disable flag to dmi so that we can handle known
 163 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 164 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 165 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 166 *         If an APM idle fails log it and idle sensibly
 167 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 168 *         Don't expect replies from clients who open the device O_RDONLY.
 169 *         (Idea from Thomas Hood)
 170 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 171 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 172 *         Notify listeners of standby or suspend events before notifying
 173 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 174 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 175 *         Ignore first resume after we generate our own resume event
 176 *         after a suspend (Thomas Hood)
 177 *         Daemonize now gets rid of our controlling terminal (sfr).
 178 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 179 *         idle_threshold (sfr).
 180 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 181 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 182 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 183 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 184 *
 185 * APM 1.1 Reference:
 186 *
 187 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 188 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 189 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 190 *
 191 * [This document is available free from Intel by calling 800.628.8686 (fax
 192 * 916.356.6100) or 800.548.4725; or from
 193 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 194 * available from Microsoft by calling 206.882.8080.]
 195 *
 196 * APM 1.2 Reference:
 197 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 198 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 199 *
 200 * [This document is available from Microsoft at:
 201 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 202 */
 203
 204#define pr_fmt(fmt) "apm: " fmt
 205
 206#include <linux/module.h>
 207
 208#include <linux/poll.h>
 209#include <linux/types.h>
 210#include <linux/stddef.h>
 211#include <linux/timer.h>
 212#include <linux/fcntl.h>
 213#include <linux/slab.h>
 214#include <linux/stat.h>
 215#include <linux/proc_fs.h>
 216#include <linux/seq_file.h>
 217#include <linux/miscdevice.h>
 218#include <linux/apm_bios.h>
 219#include <linux/init.h>
 220#include <linux/time.h>
 221#include <linux/sched.h>
 222#include <linux/pm.h>
 223#include <linux/capability.h>
 224#include <linux/device.h>
 225#include <linux/kernel.h>
 226#include <linux/freezer.h>
 227#include <linux/smp.h>
 228#include <linux/dmi.h>
 229#include <linux/suspend.h>
 230#include <linux/kthread.h>
 231#include <linux/jiffies.h>
 232#include <linux/acpi.h>
 233#include <linux/syscore_ops.h>
 234#include <linux/i8253.h>
 235#include <linux/cpuidle.h>
 236
 237#include <asm/uaccess.h>
 238#include <asm/desc.h>
 239#include <asm/olpc.h>
 240#include <asm/paravirt.h>
 241#include <asm/reboot.h>
 242
 243#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 244extern int (*console_blank_hook)(int);
 245#endif
 246
 247/*
 248 * The apm_bios device is one of the misc char devices.
 249 * This is its minor number.
 250 */
 251#define	APM_MINOR_DEV	134
 252
 253/*
 254 * Various options can be changed at boot time as follows:
 255 * (We allow underscores for compatibility with the modules code)
 256 *	apm=on/off			enable/disable APM
 257 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 258 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 259 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 260 *	    					powering off
 261 *	    [no-]debug			log some debugging messages
 262 *	    [no-]power[-_]off		power off on shutdown
 263 *	    [no-]smp			Use apm even on an SMP box
 264 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 265 *	    				bounces
 266 *          idle[-_]threshold=<n>       System idle percentage above which to
 267 *                                      make APM BIOS idle calls. Set it to
 268 *                                      100 to disable.
 269 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 270 *                                      which the idle percentage is
 271 *                                      calculated.
 272 */
 273
 274/* KNOWN PROBLEM MACHINES:
 275 *
 276 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 277 *                         [Confirmed by TI representative]
 278 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 279 *                    [Confirmed by BIOS disassembly]
 280 *                    [This may work now ...]
 281 * P: Toshiba 1950S: battery life information only gets updated after resume
 282 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 283 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 284 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 285 * 	Neale Banks <neale@lowendale.com.au> December 2000
 286 *
 287 * Legend: U = unusable with APM patches
 288 *         P = partially usable with APM patches
 289 */
 290
 291/*
 292 * Define as 1 to make the driver always call the APM BIOS busy
 293 * routine even if the clock was not reported as slowed by the
 294 * idle routine.  Otherwise, define as 0.
 295 */
 296#define ALWAYS_CALL_BUSY   1
 297
 298/*
 299 * Define to make the APM BIOS calls zero all data segment registers (so
 300 * that an incorrect BIOS implementation will cause a kernel panic if it
 301 * tries to write to arbitrary memory).
 302 */
 303#define APM_ZERO_SEGS
 304
 305#include <asm/apm.h>
 306
 307/*
 308 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 309 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 310 * David Chen <chen@ctpa04.mit.edu>
 311 */
 312#undef INIT_TIMER_AFTER_SUSPEND
 313
 314#ifdef INIT_TIMER_AFTER_SUSPEND
 315#include <linux/timex.h>
 316#include <asm/io.h>
 317#include <linux/delay.h>
 318#endif
 319
 320/*
 321 * Need to poll the APM BIOS every second
 322 */
 323#define APM_CHECK_TIMEOUT	(HZ)
 324
 325/*
 326 * Ignore suspend events for this amount of time after a resume
 327 */
 328#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 329
 330/*
 331 * Maximum number of events stored
 332 */
 333#define APM_MAX_EVENTS		20
 334
 335/*
 336 * The per-file APM data
 337 */
 338struct apm_user {
 339	int		magic;
 340	struct apm_user *next;
 341	unsigned int	suser: 1;
 342	unsigned int	writer: 1;
 343	unsigned int	reader: 1;
 344	unsigned int	suspend_wait: 1;
 345	int		suspend_result;
 346	int		suspends_pending;
 347	int		standbys_pending;
 348	int		suspends_read;
 349	int		standbys_read;
 350	int		event_head;
 351	int		event_tail;
 352	apm_event_t	events[APM_MAX_EVENTS];
 353};
 354
 355/*
 356 * The magic number in apm_user
 357 */
 358#define APM_BIOS_MAGIC		0x4101
 359
 360/*
 361 * idle percentage above which bios idle calls are done
 362 */
 363#ifdef CONFIG_APM_CPU_IDLE
 
 364#define DEFAULT_IDLE_THRESHOLD	95
 365#else
 366#define DEFAULT_IDLE_THRESHOLD	100
 367#endif
 368#define DEFAULT_IDLE_PERIOD	(100 / 3)
 369
 370static int apm_cpu_idle(struct cpuidle_device *dev,
 371			struct cpuidle_driver *drv, int index);
 372
 373static struct cpuidle_driver apm_idle_driver = {
 374	.name = "apm_idle",
 375	.owner = THIS_MODULE,
 376	.states = {
 377		{ /* entry 0 is for polling */ },
 378		{ /* entry 1 is for APM idle */
 379			.name = "APM",
 380			.desc = "APM idle",
 381			.flags = CPUIDLE_FLAG_TIME_VALID,
 382			.exit_latency = 250,	/* WAG */
 383			.target_residency = 500,	/* WAG */
 384			.enter = &apm_cpu_idle
 385		},
 386	},
 387	.state_count = 2,
 388};
 389
 390static struct cpuidle_device apm_cpuidle_device;
 391
 392/*
 393 * Local variables
 394 */
 395__visible struct {
 396	unsigned long	offset;
 397	unsigned short	segment;
 398} apm_bios_entry;
 399static int clock_slowed;
 400static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 401static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 
 402static int suspends_pending;
 403static int standbys_pending;
 404static int ignore_sys_suspend;
 405static int ignore_normal_resume;
 406static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 407
 408static bool debug __read_mostly;
 409static bool smp __read_mostly;
 410static int apm_disabled = -1;
 411#ifdef CONFIG_SMP
 412static bool power_off;
 413#else
 414static bool power_off = 1;
 415#endif
 416static bool realmode_power_off;
 417#ifdef CONFIG_APM_ALLOW_INTS
 418static bool allow_ints = 1;
 419#else
 420static bool allow_ints;
 421#endif
 422static bool broken_psr;
 423
 424static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 425static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 426static struct apm_user *user_list;
 427static DEFINE_SPINLOCK(user_list_lock);
 428static DEFINE_MUTEX(apm_mutex);
 429
 430/*
 431 * Set up a segment that references the real mode segment 0x40
 432 * that extends up to the end of page zero (that we have reserved).
 433 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 434 * even though they are called in protected mode.
 435 */
 436static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
 437			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 438
 439static const char driver_version[] = "1.16ac";	/* no spaces */
 440
 441static struct task_struct *kapmd_task;
 442
 443/*
 444 *	APM event names taken from the APM 1.2 specification. These are
 445 *	the message codes that the BIOS uses to tell us about events
 446 */
 447static const char * const apm_event_name[] = {
 448	"system standby",
 449	"system suspend",
 450	"normal resume",
 451	"critical resume",
 452	"low battery",
 453	"power status change",
 454	"update time",
 455	"critical suspend",
 456	"user standby",
 457	"user suspend",
 458	"system standby resume",
 459	"capabilities change"
 460};
 461#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 462
 463typedef struct lookup_t {
 464	int	key;
 465	char 	*msg;
 466} lookup_t;
 467
 468/*
 469 *	The BIOS returns a set of standard error codes in AX when the
 470 *	carry flag is set.
 471 */
 472
 473static const lookup_t error_table[] = {
 474/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 475	{ APM_DISABLED,		"Power management disabled" },
 476	{ APM_CONNECTED,	"Real mode interface already connected" },
 477	{ APM_NOT_CONNECTED,	"Interface not connected" },
 478	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 479/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 480	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 481	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 482	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 483	{ APM_BAD_PARAM,	"Parameter out of range" },
 484	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 485	{ APM_BAD_FUNCTION,     "Function not supported" },
 486	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 487	{ APM_BAD_STATE,	"Unable to enter requested state" },
 488/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 489	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 490	{ APM_NOT_PRESENT,	"No APM present" }
 491};
 492#define ERROR_COUNT	ARRAY_SIZE(error_table)
 493
 494/**
 495 *	apm_error	-	display an APM error
 496 *	@str: information string
 497 *	@err: APM BIOS return code
 498 *
 499 *	Write a meaningful log entry to the kernel log in the event of
 500 *	an APM error.  Note that this also handles (negative) kernel errors.
 501 */
 502
 503static void apm_error(char *str, int err)
 504{
 505	int i;
 506
 507	for (i = 0; i < ERROR_COUNT; i++)
 508		if (error_table[i].key == err)
 509			break;
 510	if (i < ERROR_COUNT)
 511		pr_notice("%s: %s\n", str, error_table[i].msg);
 512	else if (err < 0)
 513		pr_notice("%s: linux error code %i\n", str, err);
 514	else
 515		pr_notice("%s: unknown error code %#2.2x\n",
 516		       str, err);
 517}
 518
 519/*
 520 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 521 * apm_info.allow_ints, we are being really paranoid here!  Not only
 522 * are interrupts disabled, but all the segment registers (except SS)
 523 * are saved and zeroed this means that if the BIOS tries to reference
 524 * any data without explicitly loading the segment registers, the kernel
 525 * will fault immediately rather than have some unforeseen circumstances
 526 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 527 * this depends on CS referring to the same physical memory as DS so that
 528 * DS can be zeroed before the call. Unfortunately, we can't do anything
 529 * about the stack segment/pointer.  Also, we tell the compiler that
 530 * everything could change.
 531 *
 532 * Also, we KNOW that for the non error case of apm_bios_call, there
 533 * is no useful data returned in the low order 8 bits of eax.
 534 */
 535
 536static inline unsigned long __apm_irq_save(void)
 537{
 538	unsigned long flags;
 539	local_save_flags(flags);
 540	if (apm_info.allow_ints) {
 541		if (irqs_disabled_flags(flags))
 542			local_irq_enable();
 543	} else
 544		local_irq_disable();
 545
 546	return flags;
 547}
 548
 549#define apm_irq_save(flags) \
 550	do { flags = __apm_irq_save(); } while (0)
 551
 552static inline void apm_irq_restore(unsigned long flags)
 553{
 554	if (irqs_disabled_flags(flags))
 555		local_irq_disable();
 556	else if (irqs_disabled())
 557		local_irq_enable();
 558}
 559
 560#ifdef APM_ZERO_SEGS
 561#	define APM_DECL_SEGS \
 562		unsigned int saved_fs; unsigned int saved_gs;
 563#	define APM_DO_SAVE_SEGS \
 564		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 565#	define APM_DO_RESTORE_SEGS \
 566		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 567#else
 568#	define APM_DECL_SEGS
 569#	define APM_DO_SAVE_SEGS
 570#	define APM_DO_RESTORE_SEGS
 571#endif
 572
 573struct apm_bios_call {
 574	u32 func;
 575	/* In and out */
 576	u32 ebx;
 577	u32 ecx;
 578	/* Out only */
 579	u32 eax;
 580	u32 edx;
 581	u32 esi;
 582
 583	/* Error: -ENOMEM, or bits 8-15 of eax */
 584	int err;
 585};
 586
 587/**
 588 *	__apm_bios_call - Make an APM BIOS 32bit call
 589 *	@_call: pointer to struct apm_bios_call.
 590 *
 591 *	Make an APM call using the 32bit protected mode interface. The
 592 *	caller is responsible for knowing if APM BIOS is configured and
 593 *	enabled. This call can disable interrupts for a long period of
 594 *	time on some laptops.  The return value is in AH and the carry
 595 *	flag is loaded into AL.  If there is an error, then the error
 596 *	code is returned in AH (bits 8-15 of eax) and this function
 597 *	returns non-zero.
 598 *
 599 *	Note: this makes the call on the current CPU.
 600 */
 601static long __apm_bios_call(void *_call)
 602{
 603	APM_DECL_SEGS
 604	unsigned long		flags;
 605	int			cpu;
 606	struct desc_struct	save_desc_40;
 607	struct desc_struct	*gdt;
 608	struct apm_bios_call	*call = _call;
 609
 610	cpu = get_cpu();
 611	BUG_ON(cpu != 0);
 612	gdt = get_cpu_gdt_table(cpu);
 613	save_desc_40 = gdt[0x40 / 8];
 614	gdt[0x40 / 8] = bad_bios_desc;
 615
 616	apm_irq_save(flags);
 617	APM_DO_SAVE_SEGS;
 618	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 619			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 620			  &call->esi);
 621	APM_DO_RESTORE_SEGS;
 622	apm_irq_restore(flags);
 623	gdt[0x40 / 8] = save_desc_40;
 624	put_cpu();
 625
 626	return call->eax & 0xff;
 627}
 628
 629/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 630static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 631{
 632	int ret;
 633
 634	/* Don't bother with work_on_cpu in the common case, so we don't
 635	 * have to worry about OOM or overhead. */
 636	if (get_cpu() == 0) {
 637		ret = fn(call);
 638		put_cpu();
 639	} else {
 640		put_cpu();
 641		ret = work_on_cpu(0, fn, call);
 642	}
 643
 644	/* work_on_cpu can fail with -ENOMEM */
 645	if (ret < 0)
 646		call->err = ret;
 647	else
 648		call->err = (call->eax >> 8) & 0xff;
 649
 650	return ret;
 651}
 652
 653/**
 654 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 655 *	@call: the apm_bios_call registers.
 656 *
 657 *	If there is an error, it is returned in @call.err.
 658 */
 659static int apm_bios_call(struct apm_bios_call *call)
 660{
 661	return on_cpu0(__apm_bios_call, call);
 662}
 663
 664/**
 665 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 666 *	@_call: pointer to struct apm_bios_call.
 667 *
 668 *	Make a BIOS call that returns one value only, or just status.
 669 *	If there is an error, then the error code is returned in AH
 670 *	(bits 8-15 of eax) and this function returns non-zero (it can
 671 *	also return -ENOMEM). This is used for simpler BIOS operations.
 672 *	This call may hold interrupts off for a long time on some laptops.
 673 *
 674 *	Note: this makes the call on the current CPU.
 675 */
 676static long __apm_bios_call_simple(void *_call)
 677{
 678	u8			error;
 679	APM_DECL_SEGS
 680	unsigned long		flags;
 681	int			cpu;
 682	struct desc_struct	save_desc_40;
 683	struct desc_struct	*gdt;
 684	struct apm_bios_call	*call = _call;
 685
 686	cpu = get_cpu();
 687	BUG_ON(cpu != 0);
 688	gdt = get_cpu_gdt_table(cpu);
 689	save_desc_40 = gdt[0x40 / 8];
 690	gdt[0x40 / 8] = bad_bios_desc;
 691
 692	apm_irq_save(flags);
 693	APM_DO_SAVE_SEGS;
 694	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 695					 &call->eax);
 696	APM_DO_RESTORE_SEGS;
 697	apm_irq_restore(flags);
 698	gdt[0x40 / 8] = save_desc_40;
 699	put_cpu();
 700	return error;
 701}
 702
 703/**
 704 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 705 *	@func: APM function to invoke
 706 *	@ebx_in: EBX register value for BIOS call
 707 *	@ecx_in: ECX register value for BIOS call
 708 *	@eax: EAX register on return from the BIOS call
 709 *	@err: bits
 710 *
 711 *	Make a BIOS call that returns one value only, or just status.
 712 *	If there is an error, then the error code is returned in @err
 713 *	and this function returns non-zero. This is used for simpler
 714 *	BIOS operations.  This call may hold interrupts off for a long
 715 *	time on some laptops.
 716 */
 717static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 718				int *err)
 719{
 720	struct apm_bios_call call;
 721	int ret;
 722
 723	call.func = func;
 724	call.ebx = ebx_in;
 725	call.ecx = ecx_in;
 726
 727	ret = on_cpu0(__apm_bios_call_simple, &call);
 728	*eax = call.eax;
 729	*err = call.err;
 730	return ret;
 731}
 732
 733/**
 734 *	apm_driver_version	-	APM driver version
 735 *	@val:	loaded with the APM version on return
 736 *
 737 *	Retrieve the APM version supported by the BIOS. This is only
 738 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 739 *	probably present.
 740 *
 741 *	On entry val should point to a value indicating the APM driver
 742 *	version with the high byte being the major and the low byte the
 743 *	minor number both in BCD
 744 *
 745 *	On return it will hold the BIOS revision supported in the
 746 *	same format.
 747 */
 748
 749static int apm_driver_version(u_short *val)
 750{
 751	u32 eax;
 752	int err;
 753
 754	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 755		return err;
 756	*val = eax;
 757	return APM_SUCCESS;
 758}
 759
 760/**
 761 *	apm_get_event	-	get an APM event from the BIOS
 762 *	@event: pointer to the event
 763 *	@info: point to the event information
 764 *
 765 *	The APM BIOS provides a polled information for event
 766 *	reporting. The BIOS expects to be polled at least every second
 767 *	when events are pending. When a message is found the caller should
 768 *	poll until no more messages are present.  However, this causes
 769 *	problems on some laptops where a suspend event notification is
 770 *	not cleared until it is acknowledged.
 771 *
 772 *	Additional information is returned in the info pointer, providing
 773 *	that APM 1.2 is in use. If no messges are pending the value 0x80
 774 *	is returned (No power management events pending).
 775 */
 776static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 777{
 778	struct apm_bios_call call;
 779
 780	call.func = APM_FUNC_GET_EVENT;
 781	call.ebx = call.ecx = 0;
 782
 783	if (apm_bios_call(&call))
 784		return call.err;
 785
 786	*event = call.ebx;
 787	if (apm_info.connection_version < 0x0102)
 788		*info = ~0; /* indicate info not valid */
 789	else
 790		*info = call.ecx;
 791	return APM_SUCCESS;
 792}
 793
 794/**
 795 *	set_power_state	-	set the power management state
 796 *	@what: which items to transition
 797 *	@state: state to transition to
 798 *
 799 *	Request an APM change of state for one or more system devices. The
 800 *	processor state must be transitioned last of all. what holds the
 801 *	class of device in the upper byte and the device number (0xFF for
 802 *	all) for the object to be transitioned.
 803 *
 804 *	The state holds the state to transition to, which may in fact
 805 *	be an acceptance of a BIOS requested state change.
 806 */
 807
 808static int set_power_state(u_short what, u_short state)
 809{
 810	u32 eax;
 811	int err;
 812
 813	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 814		return err;
 815	return APM_SUCCESS;
 816}
 817
 818/**
 819 *	set_system_power_state - set system wide power state
 820 *	@state: which state to enter
 821 *
 822 *	Transition the entire system into a new APM power state.
 823 */
 824
 825static int set_system_power_state(u_short state)
 826{
 827	return set_power_state(APM_DEVICE_ALL, state);
 828}
 829
 830/**
 831 *	apm_do_idle	-	perform power saving
 832 *
 833 *	This function notifies the BIOS that the processor is (in the view
 834 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 835 *	to handle the idle request. On a success the function returns 1
 836 *	if the BIOS did clock slowing or 0 otherwise.
 837 */
 838
 839static int apm_do_idle(void)
 840{
 841	u32 eax;
 842	u8 ret = 0;
 843	int idled = 0;
 844	int polling;
 845	int err = 0;
 846
 847	polling = !!(current_thread_info()->status & TS_POLLING);
 848	if (polling) {
 849		current_thread_info()->status &= ~TS_POLLING;
 850		/*
 851		 * TS_POLLING-cleared state must be visible before we
 852		 * test NEED_RESCHED:
 853		 */
 854		smp_mb();
 855	}
 856	if (!need_resched()) {
 857		idled = 1;
 858		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 859	}
 860	if (polling)
 861		current_thread_info()->status |= TS_POLLING;
 862
 863	if (!idled)
 864		return 0;
 865
 866	if (ret) {
 867		static unsigned long t;
 868
 869		/* This always fails on some SMP boards running UP kernels.
 870		 * Only report the failure the first 5 times.
 871		 */
 872		if (++t < 5) {
 873			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 874			t = jiffies;
 875		}
 876		return -1;
 877	}
 878	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 879	return clock_slowed;
 880}
 881
 882/**
 883 *	apm_do_busy	-	inform the BIOS the CPU is busy
 884 *
 885 *	Request that the BIOS brings the CPU back to full performance.
 886 */
 887
 888static void apm_do_busy(void)
 889{
 890	u32 dummy;
 891	int err;
 892
 893	if (clock_slowed || ALWAYS_CALL_BUSY) {
 894		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 895		clock_slowed = 0;
 896	}
 897}
 898
 899/*
 900 * If no process has really been interested in
 901 * the CPU for some time, we want to call BIOS
 902 * power management - we probably want
 903 * to conserve power.
 904 */
 905#define IDLE_CALC_LIMIT	(HZ * 100)
 906#define IDLE_LEAKY_MAX	16
 907
 
 
 908/**
 909 * apm_cpu_idle		-	cpu idling for APM capable Linux
 910 *
 911 * This is the idling function the kernel executes when APM is available. It
 912 * tries to do BIOS powermanagement based on the average system idle time.
 913 * Furthermore it calls the system default idle routine.
 914 */
 915
 916static int apm_cpu_idle(struct cpuidle_device *dev,
 917	struct cpuidle_driver *drv, int index)
 918{
 919	static int use_apm_idle; /* = 0 */
 920	static unsigned int last_jiffies; /* = 0 */
 921	static unsigned int last_stime; /* = 0 */
 922	cputime_t stime;
 923
 924	int apm_idle_done = 0;
 925	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 926	unsigned int bucket;
 927
 
 928recalc:
 929	task_cputime(current, NULL, &stime);
 930	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 931		use_apm_idle = 0;
 
 
 932	} else if (jiffies_since_last_check > idle_period) {
 933		unsigned int idle_percentage;
 934
 935		idle_percentage = stime - last_stime;
 936		idle_percentage *= 100;
 937		idle_percentage /= jiffies_since_last_check;
 938		use_apm_idle = (idle_percentage > idle_threshold);
 939		if (apm_info.forbid_idle)
 940			use_apm_idle = 0;
 
 
 941	}
 942
 943	last_jiffies = jiffies;
 944	last_stime = stime;
 945
 946	bucket = IDLE_LEAKY_MAX;
 947
 948	while (!need_resched()) {
 949		if (use_apm_idle) {
 950			unsigned int t;
 951
 952			t = jiffies;
 953			switch (apm_do_idle()) {
 954			case 0:
 955				apm_idle_done = 1;
 956				if (t != jiffies) {
 957					if (bucket) {
 958						bucket = IDLE_LEAKY_MAX;
 959						continue;
 960					}
 961				} else if (bucket) {
 962					bucket--;
 963					continue;
 964				}
 965				break;
 966			case 1:
 967				apm_idle_done = 1;
 968				break;
 969			default: /* BIOS refused */
 970				break;
 971			}
 972		}
 973		default_idle();
 
 
 
 974		local_irq_disable();
 975		jiffies_since_last_check = jiffies - last_jiffies;
 976		if (jiffies_since_last_check > idle_period)
 977			goto recalc;
 978	}
 979
 980	if (apm_idle_done)
 981		apm_do_busy();
 982
 983	return index;
 984}
 985
 986/**
 987 *	apm_power_off	-	ask the BIOS to power off
 988 *
 989 *	Handle the power off sequence. This is the one piece of code we
 990 *	will execute even on SMP machines. In order to deal with BIOS
 991 *	bugs we support real mode APM BIOS power off calls. We also make
 992 *	the SMP call on CPU0 as some systems will only honour this call
 993 *	on their first cpu.
 994 */
 995
 996static void apm_power_off(void)
 997{
 998	/* Some bioses don't like being called from CPU != 0 */
 999	if (apm_info.realmode_power_off) {
1000		set_cpus_allowed_ptr(current, cpumask_of(0));
1001		machine_real_restart(MRR_APM);
1002	} else {
1003		(void)set_system_power_state(APM_STATE_OFF);
1004	}
1005}
1006
1007#ifdef CONFIG_APM_DO_ENABLE
1008
1009/**
1010 *	apm_enable_power_management - enable BIOS APM power management
1011 *	@enable: enable yes/no
1012 *
1013 *	Enable or disable the APM BIOS power services.
1014 */
1015
1016static int apm_enable_power_management(int enable)
1017{
1018	u32 eax;
1019	int err;
1020
1021	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1022		return APM_NOT_ENGAGED;
1023	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1024				 enable, &eax, &err))
1025		return err;
1026	if (enable)
1027		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1028	else
1029		apm_info.bios.flags |= APM_BIOS_DISABLED;
1030	return APM_SUCCESS;
1031}
1032#endif
1033
1034/**
1035 *	apm_get_power_status	-	get current power state
1036 *	@status: returned status
1037 *	@bat: battery info
1038 *	@life: estimated life
1039 *
1040 *	Obtain the current power status from the APM BIOS. We return a
1041 *	status which gives the rough battery status, and current power
1042 *	source. The bat value returned give an estimate as a percentage
1043 *	of life and a status value for the battery. The estimated life
1044 *	if reported is a lifetime in secodnds/minutes at current powwer
1045 *	consumption.
1046 */
1047
1048static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1049{
1050	struct apm_bios_call call;
1051
1052	call.func = APM_FUNC_GET_STATUS;
1053	call.ebx = APM_DEVICE_ALL;
1054	call.ecx = 0;
1055
1056	if (apm_info.get_power_status_broken)
1057		return APM_32_UNSUPPORTED;
1058	if (apm_bios_call(&call))
1059		return call.err;
1060	*status = call.ebx;
1061	*bat = call.ecx;
1062	if (apm_info.get_power_status_swabinminutes) {
1063		*life = swab16((u16)call.edx);
1064		*life |= 0x8000;
1065	} else
1066		*life = call.edx;
1067	return APM_SUCCESS;
1068}
1069
1070#if 0
1071static int apm_get_battery_status(u_short which, u_short *status,
1072				  u_short *bat, u_short *life, u_short *nbat)
1073{
1074	u32 eax;
1075	u32 ebx;
1076	u32 ecx;
1077	u32 edx;
1078	u32 esi;
1079
1080	if (apm_info.connection_version < 0x0102) {
1081		/* pretend we only have one battery. */
1082		if (which != 1)
1083			return APM_BAD_DEVICE;
1084		*nbat = 1;
1085		return apm_get_power_status(status, bat, life);
1086	}
1087
1088	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1089			  &ebx, &ecx, &edx, &esi))
1090		return (eax >> 8) & 0xff;
1091	*status = ebx;
1092	*bat = ecx;
1093	*life = edx;
1094	*nbat = esi;
1095	return APM_SUCCESS;
1096}
1097#endif
1098
1099/**
1100 *	apm_engage_power_management	-	enable PM on a device
1101 *	@device: identity of device
1102 *	@enable: on/off
1103 *
1104 *	Activate or deactive power management on either a specific device
1105 *	or the entire system (%APM_DEVICE_ALL).
1106 */
1107
1108static int apm_engage_power_management(u_short device, int enable)
1109{
1110	u32 eax;
1111	int err;
1112
1113	if ((enable == 0) && (device == APM_DEVICE_ALL)
1114	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1115		return APM_DISABLED;
1116	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1117				 &eax, &err))
1118		return err;
1119	if (device == APM_DEVICE_ALL) {
1120		if (enable)
1121			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1122		else
1123			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1124	}
1125	return APM_SUCCESS;
1126}
1127
1128#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1129
1130/**
1131 *	apm_console_blank	-	blank the display
1132 *	@blank: on/off
1133 *
1134 *	Attempt to blank the console, firstly by blanking just video device
1135 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1136 *	all video devices. Typically the BIOS will do laptop backlight and
1137 *	monitor powerdown for us.
1138 */
1139
1140static int apm_console_blank(int blank)
1141{
1142	int error = APM_NOT_ENGAGED; /* silence gcc */
1143	int i;
1144	u_short state;
1145	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1146
1147	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1148
1149	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1150		error = set_power_state(dev[i], state);
1151
1152		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1153			return 1;
1154
1155		if (error == APM_NOT_ENGAGED)
1156			break;
1157	}
1158
1159	if (error == APM_NOT_ENGAGED) {
1160		static int tried;
1161		int eng_error;
1162		if (tried++ == 0) {
1163			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1164			if (eng_error) {
1165				apm_error("set display", error);
1166				apm_error("engage interface", eng_error);
1167				return 0;
1168			} else
1169				return apm_console_blank(blank);
1170		}
1171	}
1172	apm_error("set display", error);
1173	return 0;
1174}
1175#endif
1176
1177static int queue_empty(struct apm_user *as)
1178{
1179	return as->event_head == as->event_tail;
1180}
1181
1182static apm_event_t get_queued_event(struct apm_user *as)
1183{
1184	if (++as->event_tail >= APM_MAX_EVENTS)
1185		as->event_tail = 0;
1186	return as->events[as->event_tail];
1187}
1188
1189static void queue_event(apm_event_t event, struct apm_user *sender)
1190{
1191	struct apm_user *as;
1192
1193	spin_lock(&user_list_lock);
1194	if (user_list == NULL)
1195		goto out;
1196	for (as = user_list; as != NULL; as = as->next) {
1197		if ((as == sender) || (!as->reader))
1198			continue;
1199		if (++as->event_head >= APM_MAX_EVENTS)
1200			as->event_head = 0;
1201
1202		if (as->event_head == as->event_tail) {
1203			static int notified;
1204
1205			if (notified++ == 0)
1206				pr_err("an event queue overflowed\n");
1207			if (++as->event_tail >= APM_MAX_EVENTS)
1208				as->event_tail = 0;
1209		}
1210		as->events[as->event_head] = event;
1211		if (!as->suser || !as->writer)
1212			continue;
1213		switch (event) {
1214		case APM_SYS_SUSPEND:
1215		case APM_USER_SUSPEND:
1216			as->suspends_pending++;
1217			suspends_pending++;
1218			break;
1219
1220		case APM_SYS_STANDBY:
1221		case APM_USER_STANDBY:
1222			as->standbys_pending++;
1223			standbys_pending++;
1224			break;
1225		}
1226	}
1227	wake_up_interruptible(&apm_waitqueue);
1228out:
1229	spin_unlock(&user_list_lock);
1230}
1231
1232static void reinit_timer(void)
1233{
1234#ifdef INIT_TIMER_AFTER_SUSPEND
1235	unsigned long flags;
1236
1237	raw_spin_lock_irqsave(&i8253_lock, flags);
1238	/* set the clock to HZ */
1239	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1240	udelay(10);
1241	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1242	udelay(10);
1243	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1244	udelay(10);
1245	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1246#endif
1247}
1248
1249static int suspend(int vetoable)
1250{
1251	int err;
1252	struct apm_user	*as;
1253
1254	dpm_suspend_start(PMSG_SUSPEND);
1255	dpm_suspend_end(PMSG_SUSPEND);
1256
1257	local_irq_disable();
1258	syscore_suspend();
1259
1260	local_irq_enable();
1261
1262	save_processor_state();
1263	err = set_system_power_state(APM_STATE_SUSPEND);
1264	ignore_normal_resume = 1;
1265	restore_processor_state();
1266
1267	local_irq_disable();
1268	reinit_timer();
1269
1270	if (err == APM_NO_ERROR)
1271		err = APM_SUCCESS;
1272	if (err != APM_SUCCESS)
1273		apm_error("suspend", err);
1274	err = (err == APM_SUCCESS) ? 0 : -EIO;
1275
1276	syscore_resume();
1277	local_irq_enable();
1278
1279	dpm_resume_start(PMSG_RESUME);
1280	dpm_resume_end(PMSG_RESUME);
1281
1282	queue_event(APM_NORMAL_RESUME, NULL);
1283	spin_lock(&user_list_lock);
1284	for (as = user_list; as != NULL; as = as->next) {
1285		as->suspend_wait = 0;
1286		as->suspend_result = err;
1287	}
1288	spin_unlock(&user_list_lock);
1289	wake_up_interruptible(&apm_suspend_waitqueue);
1290	return err;
1291}
1292
1293static void standby(void)
1294{
1295	int err;
1296
1297	dpm_suspend_end(PMSG_SUSPEND);
1298
1299	local_irq_disable();
1300	syscore_suspend();
1301	local_irq_enable();
1302
1303	err = set_system_power_state(APM_STATE_STANDBY);
1304	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1305		apm_error("standby", err);
1306
1307	local_irq_disable();
1308	syscore_resume();
1309	local_irq_enable();
1310
1311	dpm_resume_start(PMSG_RESUME);
1312}
1313
1314static apm_event_t get_event(void)
1315{
1316	int error;
1317	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1318	apm_eventinfo_t	info;
1319
1320	static int notified;
1321
1322	/* we don't use the eventinfo */
1323	error = apm_get_event(&event, &info);
1324	if (error == APM_SUCCESS)
1325		return event;
1326
1327	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1328		apm_error("get_event", error);
1329
1330	return 0;
1331}
1332
1333static void check_events(void)
1334{
1335	apm_event_t event;
1336	static unsigned long last_resume;
1337	static int ignore_bounce;
1338
1339	while ((event = get_event()) != 0) {
1340		if (debug) {
1341			if (event <= NR_APM_EVENT_NAME)
1342				printk(KERN_DEBUG "apm: received %s notify\n",
1343				       apm_event_name[event - 1]);
1344			else
1345				printk(KERN_DEBUG "apm: received unknown "
1346				       "event 0x%02x\n", event);
1347		}
1348		if (ignore_bounce
1349		    && (time_after(jiffies, last_resume + bounce_interval)))
1350			ignore_bounce = 0;
1351
1352		switch (event) {
1353		case APM_SYS_STANDBY:
1354		case APM_USER_STANDBY:
1355			queue_event(event, NULL);
1356			if (standbys_pending <= 0)
1357				standby();
1358			break;
1359
1360		case APM_USER_SUSPEND:
1361#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1362			if (apm_info.connection_version > 0x100)
1363				set_system_power_state(APM_STATE_REJECT);
1364			break;
1365#endif
1366		case APM_SYS_SUSPEND:
1367			if (ignore_bounce) {
1368				if (apm_info.connection_version > 0x100)
1369					set_system_power_state(APM_STATE_REJECT);
1370				break;
1371			}
1372			/*
1373			 * If we are already processing a SUSPEND,
1374			 * then further SUSPEND events from the BIOS
1375			 * will be ignored.  We also return here to
1376			 * cope with the fact that the Thinkpads keep
1377			 * sending a SUSPEND event until something else
1378			 * happens!
1379			 */
1380			if (ignore_sys_suspend)
1381				return;
1382			ignore_sys_suspend = 1;
1383			queue_event(event, NULL);
1384			if (suspends_pending <= 0)
1385				(void) suspend(1);
1386			break;
1387
1388		case APM_NORMAL_RESUME:
1389		case APM_CRITICAL_RESUME:
1390		case APM_STANDBY_RESUME:
1391			ignore_sys_suspend = 0;
1392			last_resume = jiffies;
1393			ignore_bounce = 1;
1394			if ((event != APM_NORMAL_RESUME)
1395			    || (ignore_normal_resume == 0)) {
1396				dpm_resume_end(PMSG_RESUME);
1397				queue_event(event, NULL);
1398			}
1399			ignore_normal_resume = 0;
1400			break;
1401
1402		case APM_CAPABILITY_CHANGE:
1403		case APM_LOW_BATTERY:
1404		case APM_POWER_STATUS_CHANGE:
1405			queue_event(event, NULL);
1406			/* If needed, notify drivers here */
1407			break;
1408
1409		case APM_UPDATE_TIME:
1410			break;
1411
1412		case APM_CRITICAL_SUSPEND:
1413			/*
1414			 * We are not allowed to reject a critical suspend.
1415			 */
1416			(void)suspend(0);
1417			break;
1418		}
1419	}
1420}
1421
1422static void apm_event_handler(void)
1423{
1424	static int pending_count = 4;
1425	int err;
1426
1427	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1428		if ((apm_info.connection_version > 0x100) &&
1429		    (pending_count-- <= 0)) {
1430			pending_count = 4;
1431			if (debug)
1432				printk(KERN_DEBUG "apm: setting state busy\n");
1433			err = set_system_power_state(APM_STATE_BUSY);
1434			if (err)
1435				apm_error("busy", err);
1436		}
1437	} else
1438		pending_count = 4;
1439	check_events();
1440}
1441
1442/*
1443 * This is the APM thread main loop.
1444 */
1445
1446static void apm_mainloop(void)
1447{
1448	DECLARE_WAITQUEUE(wait, current);
1449
1450	add_wait_queue(&apm_waitqueue, &wait);
1451	set_current_state(TASK_INTERRUPTIBLE);
1452	for (;;) {
1453		schedule_timeout(APM_CHECK_TIMEOUT);
1454		if (kthread_should_stop())
1455			break;
1456		/*
1457		 * Ok, check all events, check for idle (and mark us sleeping
1458		 * so as not to count towards the load average)..
1459		 */
1460		set_current_state(TASK_INTERRUPTIBLE);
1461		apm_event_handler();
1462	}
1463	remove_wait_queue(&apm_waitqueue, &wait);
1464}
1465
1466static int check_apm_user(struct apm_user *as, const char *func)
1467{
1468	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1469		pr_err("%s passed bad filp\n", func);
1470		return 1;
1471	}
1472	return 0;
1473}
1474
1475static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1476{
1477	struct apm_user *as;
1478	int i;
1479	apm_event_t event;
1480
1481	as = fp->private_data;
1482	if (check_apm_user(as, "read"))
1483		return -EIO;
1484	if ((int)count < sizeof(apm_event_t))
1485		return -EINVAL;
1486	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1487		return -EAGAIN;
1488	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1489	i = count;
1490	while ((i >= sizeof(event)) && !queue_empty(as)) {
1491		event = get_queued_event(as);
1492		if (copy_to_user(buf, &event, sizeof(event))) {
1493			if (i < count)
1494				break;
1495			return -EFAULT;
1496		}
1497		switch (event) {
1498		case APM_SYS_SUSPEND:
1499		case APM_USER_SUSPEND:
1500			as->suspends_read++;
1501			break;
1502
1503		case APM_SYS_STANDBY:
1504		case APM_USER_STANDBY:
1505			as->standbys_read++;
1506			break;
1507		}
1508		buf += sizeof(event);
1509		i -= sizeof(event);
1510	}
1511	if (i < count)
1512		return count - i;
1513	if (signal_pending(current))
1514		return -ERESTARTSYS;
1515	return 0;
1516}
1517
1518static unsigned int do_poll(struct file *fp, poll_table *wait)
1519{
1520	struct apm_user *as;
1521
1522	as = fp->private_data;
1523	if (check_apm_user(as, "poll"))
1524		return 0;
1525	poll_wait(fp, &apm_waitqueue, wait);
1526	if (!queue_empty(as))
1527		return POLLIN | POLLRDNORM;
1528	return 0;
1529}
1530
1531static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1532{
1533	struct apm_user *as;
1534	int ret;
1535
1536	as = filp->private_data;
1537	if (check_apm_user(as, "ioctl"))
1538		return -EIO;
1539	if (!as->suser || !as->writer)
1540		return -EPERM;
1541	switch (cmd) {
1542	case APM_IOC_STANDBY:
1543		mutex_lock(&apm_mutex);
1544		if (as->standbys_read > 0) {
1545			as->standbys_read--;
1546			as->standbys_pending--;
1547			standbys_pending--;
1548		} else
1549			queue_event(APM_USER_STANDBY, as);
1550		if (standbys_pending <= 0)
1551			standby();
1552		mutex_unlock(&apm_mutex);
1553		break;
1554	case APM_IOC_SUSPEND:
1555		mutex_lock(&apm_mutex);
1556		if (as->suspends_read > 0) {
1557			as->suspends_read--;
1558			as->suspends_pending--;
1559			suspends_pending--;
1560		} else
1561			queue_event(APM_USER_SUSPEND, as);
1562		if (suspends_pending <= 0) {
1563			ret = suspend(1);
1564			mutex_unlock(&apm_mutex);
1565		} else {
1566			as->suspend_wait = 1;
1567			mutex_unlock(&apm_mutex);
1568			wait_event_interruptible(apm_suspend_waitqueue,
1569					as->suspend_wait == 0);
1570			ret = as->suspend_result;
1571		}
1572		return ret;
1573	default:
1574		return -ENOTTY;
1575	}
1576	return 0;
1577}
1578
1579static int do_release(struct inode *inode, struct file *filp)
1580{
1581	struct apm_user *as;
1582
1583	as = filp->private_data;
1584	if (check_apm_user(as, "release"))
1585		return 0;
1586	filp->private_data = NULL;
1587	if (as->standbys_pending > 0) {
1588		standbys_pending -= as->standbys_pending;
1589		if (standbys_pending <= 0)
1590			standby();
1591	}
1592	if (as->suspends_pending > 0) {
1593		suspends_pending -= as->suspends_pending;
1594		if (suspends_pending <= 0)
1595			(void) suspend(1);
1596	}
1597	spin_lock(&user_list_lock);
1598	if (user_list == as)
1599		user_list = as->next;
1600	else {
1601		struct apm_user *as1;
1602
1603		for (as1 = user_list;
1604		     (as1 != NULL) && (as1->next != as);
1605		     as1 = as1->next)
1606			;
1607		if (as1 == NULL)
1608			pr_err("filp not in user list\n");
1609		else
1610			as1->next = as->next;
1611	}
1612	spin_unlock(&user_list_lock);
1613	kfree(as);
1614	return 0;
1615}
1616
1617static int do_open(struct inode *inode, struct file *filp)
1618{
1619	struct apm_user *as;
1620
1621	as = kmalloc(sizeof(*as), GFP_KERNEL);
1622	if (as == NULL)
 
 
1623		return -ENOMEM;
1624
1625	as->magic = APM_BIOS_MAGIC;
1626	as->event_tail = as->event_head = 0;
1627	as->suspends_pending = as->standbys_pending = 0;
1628	as->suspends_read = as->standbys_read = 0;
1629	/*
1630	 * XXX - this is a tiny bit broken, when we consider BSD
1631	 * process accounting. If the device is opened by root, we
1632	 * instantly flag that we used superuser privs. Who knows,
1633	 * we might close the device immediately without doing a
1634	 * privileged operation -- cevans
1635	 */
1636	as->suser = capable(CAP_SYS_ADMIN);
1637	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1638	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1639	spin_lock(&user_list_lock);
1640	as->next = user_list;
1641	user_list = as;
1642	spin_unlock(&user_list_lock);
1643	filp->private_data = as;
1644	return 0;
1645}
1646
1647static int proc_apm_show(struct seq_file *m, void *v)
1648{
1649	unsigned short	bx;
1650	unsigned short	cx;
1651	unsigned short	dx;
1652	int		error;
1653	unsigned short  ac_line_status = 0xff;
1654	unsigned short  battery_status = 0xff;
1655	unsigned short  battery_flag   = 0xff;
1656	int		percentage     = -1;
1657	int             time_units     = -1;
1658	char            *units         = "?";
1659
1660	if ((num_online_cpus() == 1) &&
1661	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1662		ac_line_status = (bx >> 8) & 0xff;
1663		battery_status = bx & 0xff;
1664		if ((cx & 0xff) != 0xff)
1665			percentage = cx & 0xff;
1666
1667		if (apm_info.connection_version > 0x100) {
1668			battery_flag = (cx >> 8) & 0xff;
1669			if (dx != 0xffff) {
1670				units = (dx & 0x8000) ? "min" : "sec";
1671				time_units = dx & 0x7fff;
1672			}
1673		}
1674	}
1675	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1676	   from the Get Power Status (0x0a) call unless otherwise noted.
1677
1678	   0) Linux driver version (this will change if format changes)
1679	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1680	   2) APM flags from APM Installation Check (0x00):
1681	      bit 0: APM_16_BIT_SUPPORT
1682	      bit 1: APM_32_BIT_SUPPORT
1683	      bit 2: APM_IDLE_SLOWS_CLOCK
1684	      bit 3: APM_BIOS_DISABLED
1685	      bit 4: APM_BIOS_DISENGAGED
1686	   3) AC line status
1687	      0x00: Off-line
1688	      0x01: On-line
1689	      0x02: On backup power (BIOS >= 1.1 only)
1690	      0xff: Unknown
1691	   4) Battery status
1692	      0x00: High
1693	      0x01: Low
1694	      0x02: Critical
1695	      0x03: Charging
1696	      0x04: Selected battery not present (BIOS >= 1.2 only)
1697	      0xff: Unknown
1698	   5) Battery flag
1699	      bit 0: High
1700	      bit 1: Low
1701	      bit 2: Critical
1702	      bit 3: Charging
1703	      bit 7: No system battery
1704	      0xff: Unknown
1705	   6) Remaining battery life (percentage of charge):
1706	      0-100: valid
1707	      -1: Unknown
1708	   7) Remaining battery life (time units):
1709	      Number of remaining minutes or seconds
1710	      -1: Unknown
1711	   8) min = minutes; sec = seconds */
1712
1713	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1714		   driver_version,
1715		   (apm_info.bios.version >> 8) & 0xff,
1716		   apm_info.bios.version & 0xff,
1717		   apm_info.bios.flags,
1718		   ac_line_status,
1719		   battery_status,
1720		   battery_flag,
1721		   percentage,
1722		   time_units,
1723		   units);
1724	return 0;
1725}
1726
1727static int proc_apm_open(struct inode *inode, struct file *file)
1728{
1729	return single_open(file, proc_apm_show, NULL);
1730}
1731
1732static const struct file_operations apm_file_ops = {
1733	.owner		= THIS_MODULE,
1734	.open		= proc_apm_open,
1735	.read		= seq_read,
1736	.llseek		= seq_lseek,
1737	.release	= single_release,
1738};
1739
1740static int apm(void *unused)
1741{
1742	unsigned short	bx;
1743	unsigned short	cx;
1744	unsigned short	dx;
1745	int		error;
1746	char 		*power_stat;
1747	char 		*bat_stat;
1748
1749	/* 2002/08/01 - WT
1750	 * This is to avoid random crashes at boot time during initialization
1751	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1752	 * Some bioses don't like being called from CPU != 0.
1753	 * Method suggested by Ingo Molnar.
1754	 */
1755	set_cpus_allowed_ptr(current, cpumask_of(0));
1756	BUG_ON(smp_processor_id() != 0);
1757
1758	if (apm_info.connection_version == 0) {
1759		apm_info.connection_version = apm_info.bios.version;
1760		if (apm_info.connection_version > 0x100) {
1761			/*
1762			 * We only support BIOSs up to version 1.2
1763			 */
1764			if (apm_info.connection_version > 0x0102)
1765				apm_info.connection_version = 0x0102;
1766			error = apm_driver_version(&apm_info.connection_version);
1767			if (error != APM_SUCCESS) {
1768				apm_error("driver version", error);
1769				/* Fall back to an APM 1.0 connection. */
1770				apm_info.connection_version = 0x100;
1771			}
1772		}
1773	}
1774
1775	if (debug)
1776		printk(KERN_INFO "apm: Connection version %d.%d\n",
1777			(apm_info.connection_version >> 8) & 0xff,
1778			apm_info.connection_version & 0xff);
1779
1780#ifdef CONFIG_APM_DO_ENABLE
1781	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1782		/*
1783		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1784		 * is booted with PM disabled but not in the docking station.
1785		 * Unfortunate ...
1786		 */
1787		error = apm_enable_power_management(1);
1788		if (error) {
1789			apm_error("enable power management", error);
1790			return -1;
1791		}
1792	}
1793#endif
1794
1795	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1796	    && (apm_info.connection_version > 0x0100)) {
1797		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1798		if (error) {
1799			apm_error("engage power management", error);
1800			return -1;
1801		}
1802	}
1803
1804	if (debug && (num_online_cpus() == 1 || smp)) {
1805		error = apm_get_power_status(&bx, &cx, &dx);
1806		if (error)
1807			printk(KERN_INFO "apm: power status not available\n");
1808		else {
1809			switch ((bx >> 8) & 0xff) {
1810			case 0:
1811				power_stat = "off line";
1812				break;
1813			case 1:
1814				power_stat = "on line";
1815				break;
1816			case 2:
1817				power_stat = "on backup power";
1818				break;
1819			default:
1820				power_stat = "unknown";
1821				break;
1822			}
1823			switch (bx & 0xff) {
1824			case 0:
1825				bat_stat = "high";
1826				break;
1827			case 1:
1828				bat_stat = "low";
1829				break;
1830			case 2:
1831				bat_stat = "critical";
1832				break;
1833			case 3:
1834				bat_stat = "charging";
1835				break;
1836			default:
1837				bat_stat = "unknown";
1838				break;
1839			}
1840			printk(KERN_INFO
1841			       "apm: AC %s, battery status %s, battery life ",
1842			       power_stat, bat_stat);
1843			if ((cx & 0xff) == 0xff)
1844				printk("unknown\n");
1845			else
1846				printk("%d%%\n", cx & 0xff);
1847			if (apm_info.connection_version > 0x100) {
1848				printk(KERN_INFO
1849				       "apm: battery flag 0x%02x, battery life ",
1850				       (cx >> 8) & 0xff);
1851				if (dx == 0xffff)
1852					printk("unknown\n");
1853				else
1854					printk("%d %s\n", dx & 0x7fff,
1855					       (dx & 0x8000) ?
1856					       "minutes" : "seconds");
1857			}
1858		}
1859	}
1860
1861	/* Install our power off handler.. */
1862	if (power_off)
1863		pm_power_off = apm_power_off;
1864
1865	if (num_online_cpus() == 1 || smp) {
1866#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1867		console_blank_hook = apm_console_blank;
1868#endif
1869		apm_mainloop();
1870#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1871		console_blank_hook = NULL;
1872#endif
1873	}
1874
1875	return 0;
1876}
1877
1878#ifndef MODULE
1879static int __init apm_setup(char *str)
1880{
1881	int invert;
1882
1883	while ((str != NULL) && (*str != '\0')) {
1884		if (strncmp(str, "off", 3) == 0)
1885			apm_disabled = 1;
1886		if (strncmp(str, "on", 2) == 0)
1887			apm_disabled = 0;
1888		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1889		    (strncmp(str, "bounce_interval=", 16) == 0))
1890			bounce_interval = simple_strtol(str + 16, NULL, 0);
1891		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1892		    (strncmp(str, "idle_threshold=", 15) == 0))
1893			idle_threshold = simple_strtol(str + 15, NULL, 0);
1894		if ((strncmp(str, "idle-period=", 12) == 0) ||
1895		    (strncmp(str, "idle_period=", 12) == 0))
1896			idle_period = simple_strtol(str + 12, NULL, 0);
1897		invert = (strncmp(str, "no-", 3) == 0) ||
1898			(strncmp(str, "no_", 3) == 0);
1899		if (invert)
1900			str += 3;
1901		if (strncmp(str, "debug", 5) == 0)
1902			debug = !invert;
1903		if ((strncmp(str, "power-off", 9) == 0) ||
1904		    (strncmp(str, "power_off", 9) == 0))
1905			power_off = !invert;
1906		if (strncmp(str, "smp", 3) == 0) {
1907			smp = !invert;
1908			idle_threshold = 100;
1909		}
1910		if ((strncmp(str, "allow-ints", 10) == 0) ||
1911		    (strncmp(str, "allow_ints", 10) == 0))
1912			apm_info.allow_ints = !invert;
1913		if ((strncmp(str, "broken-psr", 10) == 0) ||
1914		    (strncmp(str, "broken_psr", 10) == 0))
1915			apm_info.get_power_status_broken = !invert;
1916		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1917		    (strncmp(str, "realmode_power_off", 18) == 0))
1918			apm_info.realmode_power_off = !invert;
1919		str = strchr(str, ',');
1920		if (str != NULL)
1921			str += strspn(str, ", \t");
1922	}
1923	return 1;
1924}
1925
1926__setup("apm=", apm_setup);
1927#endif
1928
1929static const struct file_operations apm_bios_fops = {
1930	.owner		= THIS_MODULE,
1931	.read		= do_read,
1932	.poll		= do_poll,
1933	.unlocked_ioctl	= do_ioctl,
1934	.open		= do_open,
1935	.release	= do_release,
1936	.llseek		= noop_llseek,
1937};
1938
1939static struct miscdevice apm_device = {
1940	APM_MINOR_DEV,
1941	"apm_bios",
1942	&apm_bios_fops
1943};
1944
1945
1946/* Simple "print if true" callback */
1947static int __init print_if_true(const struct dmi_system_id *d)
1948{
1949	printk("%s\n", d->ident);
1950	return 0;
1951}
1952
1953/*
1954 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1955 * disabled before the suspend. Linux used to get terribly confused by that.
1956 */
1957static int __init broken_ps2_resume(const struct dmi_system_id *d)
1958{
1959	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1960	       "workaround hopefully not needed.\n", d->ident);
1961	return 0;
1962}
1963
1964/* Some bioses have a broken protected mode poweroff and need to use realmode */
1965static int __init set_realmode_power_off(const struct dmi_system_id *d)
1966{
1967	if (apm_info.realmode_power_off == 0) {
1968		apm_info.realmode_power_off = 1;
1969		printk(KERN_INFO "%s bios detected. "
1970		       "Using realmode poweroff only.\n", d->ident);
1971	}
1972	return 0;
1973}
1974
1975/* Some laptops require interrupts to be enabled during APM calls */
1976static int __init set_apm_ints(const struct dmi_system_id *d)
1977{
1978	if (apm_info.allow_ints == 0) {
1979		apm_info.allow_ints = 1;
1980		printk(KERN_INFO "%s machine detected. "
1981		       "Enabling interrupts during APM calls.\n", d->ident);
1982	}
1983	return 0;
1984}
1985
1986/* Some APM bioses corrupt memory or just plain do not work */
1987static int __init apm_is_horked(const struct dmi_system_id *d)
1988{
1989	if (apm_info.disabled == 0) {
1990		apm_info.disabled = 1;
1991		printk(KERN_INFO "%s machine detected. "
1992		       "Disabling APM.\n", d->ident);
1993	}
1994	return 0;
1995}
1996
1997static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1998{
1999	if (apm_info.disabled == 0) {
2000		apm_info.disabled = 1;
2001		printk(KERN_INFO "%s machine detected. "
2002		       "Disabling APM.\n", d->ident);
2003		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
2004		printk(KERN_INFO "download from support.intel.com\n");
2005	}
2006	return 0;
2007}
2008
2009/* Some APM bioses hang on APM idle calls */
2010static int __init apm_likes_to_melt(const struct dmi_system_id *d)
2011{
2012	if (apm_info.forbid_idle == 0) {
2013		apm_info.forbid_idle = 1;
2014		printk(KERN_INFO "%s machine detected. "
2015		       "Disabling APM idle calls.\n", d->ident);
2016	}
2017	return 0;
2018}
2019
2020/*
2021 *  Check for clue free BIOS implementations who use
2022 *  the following QA technique
2023 *
2024 *      [ Write BIOS Code ]<------
2025 *               |                ^
2026 *      < Does it Compile >----N--
2027 *               |Y               ^
2028 *	< Does it Boot Win98 >-N--
2029 *               |Y
2030 *           [Ship It]
2031 *
2032 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2033 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2034 */
2035static int __init broken_apm_power(const struct dmi_system_id *d)
2036{
2037	apm_info.get_power_status_broken = 1;
2038	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2039	       "disabling power status reporting.\n");
2040	return 0;
2041}
2042
2043/*
2044 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2045 * have this problem).
2046 */
2047static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2048{
2049	apm_info.get_power_status_swabinminutes = 1;
2050	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2051	       "in minutes and wrong byte order.\n");
2052	return 0;
2053}
2054
2055static struct dmi_system_id __initdata apm_dmi_table[] = {
2056	{
2057		print_if_true,
2058		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2059		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2060			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2061	},
2062	{	/* Handle problems with APM on the C600 */
2063		broken_ps2_resume, "Dell Latitude C600",
2064		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2065			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2066	},
2067	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2068		set_apm_ints, "Dell Latitude",
2069		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2070			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2071	},
2072	{	/* APM crashes */
2073		apm_is_horked, "Dell Inspiron 2500",
2074		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2075			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2076			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2077			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2078	},
2079	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2080		set_apm_ints, "Dell Inspiron", {
2081			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2082			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2083	},
2084	{	/* Handle problems with APM on Inspiron 5000e */
2085		broken_apm_power, "Dell Inspiron 5000e",
2086		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2087			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2088			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2089	},
2090	{	/* Handle problems with APM on Inspiron 2500 */
2091		broken_apm_power, "Dell Inspiron 2500",
2092		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2093			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2094			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2095	},
2096	{	/* APM crashes */
2097		apm_is_horked, "Dell Dimension 4100",
2098		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2099			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2100			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2101			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2102	},
2103	{	/* Allow interrupts during suspend on Compaq Laptops*/
2104		set_apm_ints, "Compaq 12XL125",
2105		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2106			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2107			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2108			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2109	},
2110	{	/* Allow interrupts during APM or the clock goes slow */
2111		set_apm_ints, "ASUSTeK",
2112		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2113			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2114	},
2115	{	/* APM blows on shutdown */
2116		apm_is_horked, "ABIT KX7-333[R]",
2117		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2118			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2119	},
2120	{	/* APM crashes */
2121		apm_is_horked, "Trigem Delhi3",
2122		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2123			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2124	},
2125	{	/* APM crashes */
2126		apm_is_horked, "Fujitsu-Siemens",
2127		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2128			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2129	},
2130	{	/* APM crashes */
2131		apm_is_horked_d850md, "Intel D850MD",
2132		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2133			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2134	},
2135	{	/* APM crashes */
2136		apm_is_horked, "Intel D810EMO",
2137		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2138			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2139	},
2140	{	/* APM crashes */
2141		apm_is_horked, "Dell XPS-Z",
2142		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2143			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2144			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2145	},
2146	{	/* APM crashes */
2147		apm_is_horked, "Sharp PC-PJ/AX",
2148		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2149			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2150			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2151			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2152	},
2153	{	/* APM crashes */
2154		apm_is_horked, "Dell Inspiron 2500",
2155		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2156			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2157			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2158			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2159	},
2160	{	/* APM idle hangs */
2161		apm_likes_to_melt, "Jabil AMD",
2162		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2163			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2164	},
2165	{	/* APM idle hangs */
2166		apm_likes_to_melt, "AMI Bios",
2167		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2168			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2169	},
2170	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2171		swab_apm_power_in_minutes, "Sony VAIO",
2172		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2173			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2174			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2175	},
2176	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2177		swab_apm_power_in_minutes, "Sony VAIO",
2178		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2179			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2180			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2181	},
2182	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2183		swab_apm_power_in_minutes, "Sony VAIO",
2184		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2185			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2186			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2187	},
2188	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2189		swab_apm_power_in_minutes, "Sony VAIO",
2190		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2191			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2192			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2193	},
2194	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2195		swab_apm_power_in_minutes, "Sony VAIO",
2196		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2197			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2198			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2199	},
2200	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2201		swab_apm_power_in_minutes, "Sony VAIO",
2202		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2203			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2204			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2205	},
2206	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2207		swab_apm_power_in_minutes, "Sony VAIO",
2208		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2209			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2210			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2211	},
2212	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2213		swab_apm_power_in_minutes, "Sony VAIO",
2214		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2215			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2216			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2217	},
2218	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2219		swab_apm_power_in_minutes, "Sony VAIO",
2220		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2221			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2222			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2223	},
2224	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2225		swab_apm_power_in_minutes, "Sony VAIO",
2226		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2227			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2228			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2229	},
2230
2231	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2232		swab_apm_power_in_minutes, "Sony VAIO",
2233		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2234			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2235			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2236	},
2237	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2238		swab_apm_power_in_minutes, "Sony VAIO",
2239		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2240			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2241			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2242	},
2243	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2244		swab_apm_power_in_minutes, "Sony VAIO",
2245		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2246			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2247			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2248	},
2249	{	/* broken PM poweroff bios */
2250		set_realmode_power_off, "Award Software v4.60 PGMA",
2251		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2252			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2253			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2254	},
2255
2256	/* Generic per vendor APM settings  */
2257
2258	{	/* Allow interrupts during suspend on IBM laptops */
2259		set_apm_ints, "IBM",
2260		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2261	},
2262
2263	{ }
2264};
2265
2266/*
2267 * Just start the APM thread. We do NOT want to do APM BIOS
2268 * calls from anything but the APM thread, if for no other reason
2269 * than the fact that we don't trust the APM BIOS. This way,
2270 * most common APM BIOS problems that lead to protection errors
2271 * etc will have at least some level of being contained...
2272 *
2273 * In short, if something bad happens, at least we have a choice
2274 * of just killing the apm thread..
2275 */
2276static int __init apm_init(void)
2277{
2278	struct desc_struct *gdt;
2279	int err;
2280
2281	dmi_check_system(apm_dmi_table);
2282
2283	if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2284		printk(KERN_INFO "apm: BIOS not found.\n");
2285		return -ENODEV;
2286	}
2287	printk(KERN_INFO
2288	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2289	       ((apm_info.bios.version >> 8) & 0xff),
2290	       (apm_info.bios.version & 0xff),
2291	       apm_info.bios.flags,
2292	       driver_version);
2293	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2294		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2295		return -ENODEV;
2296	}
2297
2298	if (allow_ints)
2299		apm_info.allow_ints = 1;
2300	if (broken_psr)
2301		apm_info.get_power_status_broken = 1;
2302	if (realmode_power_off)
2303		apm_info.realmode_power_off = 1;
2304	/* User can override, but default is to trust DMI */
2305	if (apm_disabled != -1)
2306		apm_info.disabled = apm_disabled;
2307
2308	/*
2309	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2310	 * but is reportedly a 1.0 BIOS.
2311	 */
2312	if (apm_info.bios.version == 0x001)
2313		apm_info.bios.version = 0x100;
2314
2315	/* BIOS < 1.2 doesn't set cseg_16_len */
2316	if (apm_info.bios.version < 0x102)
2317		apm_info.bios.cseg_16_len = 0; /* 64k */
2318
2319	if (debug) {
2320		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2321			apm_info.bios.cseg, apm_info.bios.offset,
2322			apm_info.bios.cseg_16, apm_info.bios.dseg);
2323		if (apm_info.bios.version > 0x100)
2324			printk(" cseg len %x, dseg len %x",
2325				apm_info.bios.cseg_len,
2326				apm_info.bios.dseg_len);
2327		if (apm_info.bios.version > 0x101)
2328			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2329		printk("\n");
2330	}
2331
2332	if (apm_info.disabled) {
2333		pr_notice("disabled on user request.\n");
2334		return -ENODEV;
2335	}
2336	if ((num_online_cpus() > 1) && !power_off && !smp) {
2337		pr_notice("disabled - APM is not SMP safe.\n");
2338		apm_info.disabled = 1;
2339		return -ENODEV;
2340	}
2341	if (!acpi_disabled) {
2342		pr_notice("overridden by ACPI.\n");
2343		apm_info.disabled = 1;
2344		return -ENODEV;
2345	}
2346
2347	/*
2348	 * Set up the long jump entry point to the APM BIOS, which is called
2349	 * from inline assembly.
2350	 */
2351	apm_bios_entry.offset = apm_info.bios.offset;
2352	apm_bios_entry.segment = APM_CS;
2353
2354	/*
2355	 * The APM 1.1 BIOS is supposed to provide limit information that it
2356	 * recognizes.  Many machines do this correctly, but many others do
2357	 * not restrict themselves to their claimed limit.  When this happens,
2358	 * they will cause a segmentation violation in the kernel at boot time.
2359	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2360	 *
2361	 * Note we only set APM segments on CPU zero, since we pin the APM
2362	 * code to that CPU.
2363	 */
2364	gdt = get_cpu_gdt_table(0);
2365	set_desc_base(&gdt[APM_CS >> 3],
2366		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2367	set_desc_base(&gdt[APM_CS_16 >> 3],
2368		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2369	set_desc_base(&gdt[APM_DS >> 3],
2370		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2371
2372	proc_create("apm", 0, NULL, &apm_file_ops);
2373
2374	kapmd_task = kthread_create(apm, NULL, "kapmd");
2375	if (IS_ERR(kapmd_task)) {
2376		pr_err("disabled - Unable to start kernel thread\n");
 
2377		err = PTR_ERR(kapmd_task);
2378		kapmd_task = NULL;
2379		remove_proc_entry("apm", NULL);
2380		return err;
2381	}
2382	wake_up_process(kapmd_task);
2383
2384	if (num_online_cpus() > 1 && !smp) {
2385		printk(KERN_NOTICE
2386		       "apm: disabled - APM is not SMP safe (power off active).\n");
2387		return 0;
2388	}
2389
2390	/*
2391	 * Note we don't actually care if the misc_device cannot be registered.
2392	 * this driver can do its job without it, even if userspace can't
2393	 * control it.  just log the error
2394	 */
2395	if (misc_register(&apm_device))
2396		printk(KERN_WARNING "apm: Could not register misc device.\n");
2397
2398	if (HZ != 100)
2399		idle_period = (idle_period * HZ) / 100;
2400	if (idle_threshold < 100) {
2401		if (!cpuidle_register_driver(&apm_idle_driver))
2402			if (cpuidle_register_device(&apm_cpuidle_device))
2403				cpuidle_unregister_driver(&apm_idle_driver);
2404	}
2405
2406	return 0;
2407}
2408
2409static void __exit apm_exit(void)
2410{
2411	int error;
2412
2413	cpuidle_unregister_device(&apm_cpuidle_device);
2414	cpuidle_unregister_driver(&apm_idle_driver);
2415
 
 
 
 
 
 
2416	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2417	    && (apm_info.connection_version > 0x0100)) {
2418		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2419		if (error)
2420			apm_error("disengage power management", error);
2421	}
2422	misc_deregister(&apm_device);
2423	remove_proc_entry("apm", NULL);
2424	if (power_off)
2425		pm_power_off = NULL;
2426	if (kapmd_task) {
2427		kthread_stop(kapmd_task);
2428		kapmd_task = NULL;
2429	}
2430}
2431
2432module_init(apm_init);
2433module_exit(apm_exit);
2434
2435MODULE_AUTHOR("Stephen Rothwell");
2436MODULE_DESCRIPTION("Advanced Power Management");
2437MODULE_LICENSE("GPL");
2438module_param(debug, bool, 0644);
2439MODULE_PARM_DESC(debug, "Enable debug mode");
2440module_param(power_off, bool, 0444);
2441MODULE_PARM_DESC(power_off, "Enable power off");
2442module_param(bounce_interval, int, 0444);
2443MODULE_PARM_DESC(bounce_interval,
2444		"Set the number of ticks to ignore suspend bounces");
2445module_param(allow_ints, bool, 0444);
2446MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2447module_param(broken_psr, bool, 0444);
2448MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2449module_param(realmode_power_off, bool, 0444);
2450MODULE_PARM_DESC(realmode_power_off,
2451		"Switch to real mode before powering off");
2452module_param(idle_threshold, int, 0444);
2453MODULE_PARM_DESC(idle_threshold,
2454	"System idle percentage above which to make APM BIOS idle calls");
2455module_param(idle_period, int, 0444);
2456MODULE_PARM_DESC(idle_period,
2457	"Period (in sec/100) over which to caculate the idle percentage");
2458module_param(smp, bool, 0444);
2459MODULE_PARM_DESC(smp,
2460	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2461MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
v3.5.6
   1/* -*- linux-c -*-
   2 * APM BIOS driver for Linux
   3 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   4 *
   5 * Initial development of this driver was funded by NEC Australia P/L
   6 *	and NEC Corporation
   7 *
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms of the GNU General Public License as published by the
  10 * Free Software Foundation; either version 2, or (at your option) any
  11 * later version.
  12 *
  13 * This program is distributed in the hope that it will be useful, but
  14 * WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 * General Public License for more details.
  17 *
  18 * October 1995, Rik Faith (faith@cs.unc.edu):
  19 *    Minor enhancements and updates (to the patch set) for 1.3.x
  20 *    Documentation
  21 * January 1996, Rik Faith (faith@cs.unc.edu):
  22 *    Make /proc/apm easy to format (bump driver version)
  23 * March 1996, Rik Faith (faith@cs.unc.edu):
  24 *    Prohibit APM BIOS calls unless apm_enabled.
  25 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  26 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  27 *    Version 1.0 and 1.1
  28 * May 1996, Version 1.2
  29 * Feb 1998, Version 1.3
  30 * Feb 1998, Version 1.4
  31 * Aug 1998, Version 1.5
  32 * Sep 1998, Version 1.6
  33 * Nov 1998, Version 1.7
  34 * Jan 1999, Version 1.8
  35 * Jan 1999, Version 1.9
  36 * Oct 1999, Version 1.10
  37 * Nov 1999, Version 1.11
  38 * Jan 2000, Version 1.12
  39 * Feb 2000, Version 1.13
  40 * Nov 2000, Version 1.14
  41 * Oct 2001, Version 1.15
  42 * Jan 2002, Version 1.16
  43 * Oct 2002, Version 1.16ac
  44 *
  45 * History:
  46 *    0.6b: first version in official kernel, Linux 1.3.46
  47 *    0.7: changed /proc/apm format, Linux 1.3.58
  48 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  49 *    0.9: only call bios if bios is present, Linux 1.3.72
  50 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  51 *         Linux 1.3.85
  52 *    1.1: support user-space standby and suspend, power off after system
  53 *         halted, Linux 1.3.98
  54 *    1.2: When resetting RTC after resume, take care so that the time
  55 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  56 *         <jtoth@princeton.edu>); improve interaction between
  57 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  58 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  59 *	   levels to the printk calls. APM is not defined for SMP machines.
  60 *         The new replacement for it is, but Linux doesn't yet support this.
  61 *         Alan Cox Linux 2.1.55
  62 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  63 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  64 *         Dean Gaudet <dgaudet@arctic.org>.
  65 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  66 *    1.5: Fix segment register reloading (in case of bad segments saved
  67 *         across BIOS call).
  68 *         Stephen Rothwell
  69 *    1.6: Cope with compiler/assembler differences.
  70 *         Only try to turn off the first display device.
  71 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  72 *                   <echter@informatik.uni-rostock.de>
  73 *         Stephen Rothwell
  74 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  75 *         to reflect current state of APM BIOS.
  76 *         Chris Rankin <rankinc@bellsouth.net>
  77 *         Reset interrupt 0 timer to 100Hz after suspend
  78 *         Chad Miller <cmiller@surfsouth.com>
  79 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  80 *         Richard Gooch <rgooch@atnf.csiro.au>
  81 *         Allow boot time disabling of APM
  82 *         Make boot messages far less verbose by default
  83 *         Make asm safer
  84 *         Stephen Rothwell
  85 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  86 *         Richard Gooch <rgooch@atnf.csiro.au>
  87 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  88 *         remove dependency on CONFIG_PROC_FS
  89 *         Stephen Rothwell
  90 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  91 *         Try to cope with BIOS's that need to have all display
  92 *         devices blanked and not just the first one.
  93 *         Ross Paterson <ross@soi.city.ac.uk>
  94 *         Fix segment limit setting it has always been wrong as
  95 *         the segments needed to have byte granularity.
  96 *         Mark a few things __init.
  97 *         Add hack to allow power off of SMP systems by popular request.
  98 *         Use CONFIG_SMP instead of __SMP__
  99 *         Ignore BOUNCES for three seconds.
 100 *         Stephen Rothwell
 101 *   1.10: Fix for Thinkpad return code.
 102 *         Merge 2.2 and 2.3 drivers.
 103 *         Remove APM dependencies in arch/i386/kernel/process.c
 104 *         Remove APM dependencies in drivers/char/sysrq.c
 105 *         Reset time across standby.
 106 *         Allow more inititialisation on SMP.
 107 *         Remove CONFIG_APM_POWER_OFF and make it boot time
 108 *         configurable (default on).
 109 *         Make debug only a boot time parameter (remove APM_DEBUG).
 110 *         Try to blank all devices on any error.
 111 *   1.11: Remove APM dependencies in drivers/char/console.c
 112 *         Check nr_running to detect if we are idle (from
 113 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 114 *         Fix for bioses that don't zero the top part of the
 115 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 116 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 117 *         Real mode power off patch (Walter Hofmann
 118 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 119 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 120 *         the code away anyway (smp_num_cpus == 1 in UP)
 121 *         noted by Artur Skawina <skawina@geocities.com>.
 122 *         Make power off under SMP work again.
 123 *         Fix thinko with initial engaging of BIOS.
 124 *         Make sure power off only happens on CPU 0
 125 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 126 *         Do error notification to user mode if BIOS calls fail.
 127 *         Move entrypoint offset fix to ...boot/setup.S
 128 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 129 *         Remove smp-power-off. SMP users must now specify
 130 *         "apm=power-off" on the kernel command line. Suggested
 131 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 132 *         <alan@lxorguk.ukuu.org.uk>.
 133 *         Register the /proc/apm entry even on SMP so that
 134 *         scripts that check for it before doing power off
 135 *         work (Jim Avera <jima@hal.com>).
 136 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 137 *         <andy_henroid@yahoo.com>).
 138 *         Modularize the code.
 139 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 140 *         is now the way life works).
 141 *         Fix thinko in suspend() (wrong return).
 142 *         Notify drivers on critical suspend.
 143 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 144 *         modified by sfr).
 145 *         Disable interrupts while we are suspended (Andy Henroid
 146 *         <andy_henroid@yahoo.com> fixed by sfr).
 147 *         Make power off work on SMP again (Tony Hoyle
 148 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 149 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 150 *         interval is now configurable.
 151 *   1.14: Make connection version persist across module unload/load.
 152 *         Enable and engage power management earlier.
 153 *         Disengage power management on module unload.
 154 *         Changed to use the sysrq-register hack for registering the
 155 *         power off function called by magic sysrq based upon discussions
 156 *         in irc://irc.openprojects.net/#kernelnewbies
 157 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 158 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 159 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 160 *         Work around byte swap bug in one of the Vaio's BIOS's
 161 *         (Marc Boucher <marc@mbsi.ca>).
 162 *         Exposed the disable flag to dmi so that we can handle known
 163 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 164 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 165 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 166 *         If an APM idle fails log it and idle sensibly
 167 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 168 *         Don't expect replies from clients who open the device O_RDONLY.
 169 *         (Idea from Thomas Hood)
 170 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 171 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 172 *         Notify listeners of standby or suspend events before notifying
 173 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 174 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 175 *         Ignore first resume after we generate our own resume event
 176 *         after a suspend (Thomas Hood)
 177 *         Daemonize now gets rid of our controlling terminal (sfr).
 178 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 179 *         idle_threshold (sfr).
 180 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 181 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 182 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 183 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 184 *
 185 * APM 1.1 Reference:
 186 *
 187 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 188 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 189 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 190 *
 191 * [This document is available free from Intel by calling 800.628.8686 (fax
 192 * 916.356.6100) or 800.548.4725; or from
 193 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 194 * available from Microsoft by calling 206.882.8080.]
 195 *
 196 * APM 1.2 Reference:
 197 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 198 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 199 *
 200 * [This document is available from Microsoft at:
 201 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 202 */
 203
 
 
 204#include <linux/module.h>
 205
 206#include <linux/poll.h>
 207#include <linux/types.h>
 208#include <linux/stddef.h>
 209#include <linux/timer.h>
 210#include <linux/fcntl.h>
 211#include <linux/slab.h>
 212#include <linux/stat.h>
 213#include <linux/proc_fs.h>
 214#include <linux/seq_file.h>
 215#include <linux/miscdevice.h>
 216#include <linux/apm_bios.h>
 217#include <linux/init.h>
 218#include <linux/time.h>
 219#include <linux/sched.h>
 220#include <linux/pm.h>
 221#include <linux/capability.h>
 222#include <linux/device.h>
 223#include <linux/kernel.h>
 224#include <linux/freezer.h>
 225#include <linux/smp.h>
 226#include <linux/dmi.h>
 227#include <linux/suspend.h>
 228#include <linux/kthread.h>
 229#include <linux/jiffies.h>
 230#include <linux/acpi.h>
 231#include <linux/syscore_ops.h>
 232#include <linux/i8253.h>
 
 233
 234#include <asm/uaccess.h>
 235#include <asm/desc.h>
 236#include <asm/olpc.h>
 237#include <asm/paravirt.h>
 238#include <asm/reboot.h>
 239
 240#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 241extern int (*console_blank_hook)(int);
 242#endif
 243
 244/*
 245 * The apm_bios device is one of the misc char devices.
 246 * This is its minor number.
 247 */
 248#define	APM_MINOR_DEV	134
 249
 250/*
 251 * Various options can be changed at boot time as follows:
 252 * (We allow underscores for compatibility with the modules code)
 253 *	apm=on/off			enable/disable APM
 254 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 255 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 256 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 257 *	    					powering off
 258 *	    [no-]debug			log some debugging messages
 259 *	    [no-]power[-_]off		power off on shutdown
 260 *	    [no-]smp			Use apm even on an SMP box
 261 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 262 *	    				bounces
 263 *          idle[-_]threshold=<n>       System idle percentage above which to
 264 *                                      make APM BIOS idle calls. Set it to
 265 *                                      100 to disable.
 266 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 267 *                                      which the idle percentage is
 268 *                                      calculated.
 269 */
 270
 271/* KNOWN PROBLEM MACHINES:
 272 *
 273 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 274 *                         [Confirmed by TI representative]
 275 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 276 *                    [Confirmed by BIOS disassembly]
 277 *                    [This may work now ...]
 278 * P: Toshiba 1950S: battery life information only gets updated after resume
 279 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 280 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 281 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 282 * 	Neale Banks <neale@lowendale.com.au> December 2000
 283 *
 284 * Legend: U = unusable with APM patches
 285 *         P = partially usable with APM patches
 286 */
 287
 288/*
 289 * Define as 1 to make the driver always call the APM BIOS busy
 290 * routine even if the clock was not reported as slowed by the
 291 * idle routine.  Otherwise, define as 0.
 292 */
 293#define ALWAYS_CALL_BUSY   1
 294
 295/*
 296 * Define to make the APM BIOS calls zero all data segment registers (so
 297 * that an incorrect BIOS implementation will cause a kernel panic if it
 298 * tries to write to arbitrary memory).
 299 */
 300#define APM_ZERO_SEGS
 301
 302#include <asm/apm.h>
 303
 304/*
 305 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 306 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 307 * David Chen <chen@ctpa04.mit.edu>
 308 */
 309#undef INIT_TIMER_AFTER_SUSPEND
 310
 311#ifdef INIT_TIMER_AFTER_SUSPEND
 312#include <linux/timex.h>
 313#include <asm/io.h>
 314#include <linux/delay.h>
 315#endif
 316
 317/*
 318 * Need to poll the APM BIOS every second
 319 */
 320#define APM_CHECK_TIMEOUT	(HZ)
 321
 322/*
 323 * Ignore suspend events for this amount of time after a resume
 324 */
 325#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 326
 327/*
 328 * Maximum number of events stored
 329 */
 330#define APM_MAX_EVENTS		20
 331
 332/*
 333 * The per-file APM data
 334 */
 335struct apm_user {
 336	int		magic;
 337	struct apm_user *next;
 338	unsigned int	suser: 1;
 339	unsigned int	writer: 1;
 340	unsigned int	reader: 1;
 341	unsigned int	suspend_wait: 1;
 342	int		suspend_result;
 343	int		suspends_pending;
 344	int		standbys_pending;
 345	int		suspends_read;
 346	int		standbys_read;
 347	int		event_head;
 348	int		event_tail;
 349	apm_event_t	events[APM_MAX_EVENTS];
 350};
 351
 352/*
 353 * The magic number in apm_user
 354 */
 355#define APM_BIOS_MAGIC		0x4101
 356
 357/*
 358 * idle percentage above which bios idle calls are done
 359 */
 360#ifdef CONFIG_APM_CPU_IDLE
 361#warning deprecated CONFIG_APM_CPU_IDLE will be deleted in 2012
 362#define DEFAULT_IDLE_THRESHOLD	95
 363#else
 364#define DEFAULT_IDLE_THRESHOLD	100
 365#endif
 366#define DEFAULT_IDLE_PERIOD	(100 / 3)
 367
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 368/*
 369 * Local variables
 370 */
 371static struct {
 372	unsigned long	offset;
 373	unsigned short	segment;
 374} apm_bios_entry;
 375static int clock_slowed;
 376static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 377static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 378static int set_pm_idle;
 379static int suspends_pending;
 380static int standbys_pending;
 381static int ignore_sys_suspend;
 382static int ignore_normal_resume;
 383static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 384
 385static bool debug __read_mostly;
 386static bool smp __read_mostly;
 387static int apm_disabled = -1;
 388#ifdef CONFIG_SMP
 389static bool power_off;
 390#else
 391static bool power_off = 1;
 392#endif
 393static bool realmode_power_off;
 394#ifdef CONFIG_APM_ALLOW_INTS
 395static bool allow_ints = 1;
 396#else
 397static bool allow_ints;
 398#endif
 399static bool broken_psr;
 400
 401static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 402static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 403static struct apm_user *user_list;
 404static DEFINE_SPINLOCK(user_list_lock);
 405static DEFINE_MUTEX(apm_mutex);
 406
 407/*
 408 * Set up a segment that references the real mode segment 0x40
 409 * that extends up to the end of page zero (that we have reserved).
 410 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 411 * even though they are called in protected mode.
 412 */
 413static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
 414			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 415
 416static const char driver_version[] = "1.16ac";	/* no spaces */
 417
 418static struct task_struct *kapmd_task;
 419
 420/*
 421 *	APM event names taken from the APM 1.2 specification. These are
 422 *	the message codes that the BIOS uses to tell us about events
 423 */
 424static const char * const apm_event_name[] = {
 425	"system standby",
 426	"system suspend",
 427	"normal resume",
 428	"critical resume",
 429	"low battery",
 430	"power status change",
 431	"update time",
 432	"critical suspend",
 433	"user standby",
 434	"user suspend",
 435	"system standby resume",
 436	"capabilities change"
 437};
 438#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 439
 440typedef struct lookup_t {
 441	int	key;
 442	char 	*msg;
 443} lookup_t;
 444
 445/*
 446 *	The BIOS returns a set of standard error codes in AX when the
 447 *	carry flag is set.
 448 */
 449
 450static const lookup_t error_table[] = {
 451/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 452	{ APM_DISABLED,		"Power management disabled" },
 453	{ APM_CONNECTED,	"Real mode interface already connected" },
 454	{ APM_NOT_CONNECTED,	"Interface not connected" },
 455	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 456/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 457	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 458	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 459	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 460	{ APM_BAD_PARAM,	"Parameter out of range" },
 461	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 462	{ APM_BAD_FUNCTION,     "Function not supported" },
 463	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 464	{ APM_BAD_STATE,	"Unable to enter requested state" },
 465/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 466	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 467	{ APM_NOT_PRESENT,	"No APM present" }
 468};
 469#define ERROR_COUNT	ARRAY_SIZE(error_table)
 470
 471/**
 472 *	apm_error	-	display an APM error
 473 *	@str: information string
 474 *	@err: APM BIOS return code
 475 *
 476 *	Write a meaningful log entry to the kernel log in the event of
 477 *	an APM error.  Note that this also handles (negative) kernel errors.
 478 */
 479
 480static void apm_error(char *str, int err)
 481{
 482	int i;
 483
 484	for (i = 0; i < ERROR_COUNT; i++)
 485		if (error_table[i].key == err)
 486			break;
 487	if (i < ERROR_COUNT)
 488		printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
 489	else if (err < 0)
 490		printk(KERN_NOTICE "apm: %s: linux error code %i\n", str, err);
 491	else
 492		printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
 493		       str, err);
 494}
 495
 496/*
 497 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 498 * apm_info.allow_ints, we are being really paranoid here!  Not only
 499 * are interrupts disabled, but all the segment registers (except SS)
 500 * are saved and zeroed this means that if the BIOS tries to reference
 501 * any data without explicitly loading the segment registers, the kernel
 502 * will fault immediately rather than have some unforeseen circumstances
 503 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 504 * this depends on CS referring to the same physical memory as DS so that
 505 * DS can be zeroed before the call. Unfortunately, we can't do anything
 506 * about the stack segment/pointer.  Also, we tell the compiler that
 507 * everything could change.
 508 *
 509 * Also, we KNOW that for the non error case of apm_bios_call, there
 510 * is no useful data returned in the low order 8 bits of eax.
 511 */
 512
 513static inline unsigned long __apm_irq_save(void)
 514{
 515	unsigned long flags;
 516	local_save_flags(flags);
 517	if (apm_info.allow_ints) {
 518		if (irqs_disabled_flags(flags))
 519			local_irq_enable();
 520	} else
 521		local_irq_disable();
 522
 523	return flags;
 524}
 525
 526#define apm_irq_save(flags) \
 527	do { flags = __apm_irq_save(); } while (0)
 528
 529static inline void apm_irq_restore(unsigned long flags)
 530{
 531	if (irqs_disabled_flags(flags))
 532		local_irq_disable();
 533	else if (irqs_disabled())
 534		local_irq_enable();
 535}
 536
 537#ifdef APM_ZERO_SEGS
 538#	define APM_DECL_SEGS \
 539		unsigned int saved_fs; unsigned int saved_gs;
 540#	define APM_DO_SAVE_SEGS \
 541		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 542#	define APM_DO_RESTORE_SEGS \
 543		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 544#else
 545#	define APM_DECL_SEGS
 546#	define APM_DO_SAVE_SEGS
 547#	define APM_DO_RESTORE_SEGS
 548#endif
 549
 550struct apm_bios_call {
 551	u32 func;
 552	/* In and out */
 553	u32 ebx;
 554	u32 ecx;
 555	/* Out only */
 556	u32 eax;
 557	u32 edx;
 558	u32 esi;
 559
 560	/* Error: -ENOMEM, or bits 8-15 of eax */
 561	int err;
 562};
 563
 564/**
 565 *	__apm_bios_call - Make an APM BIOS 32bit call
 566 *	@_call: pointer to struct apm_bios_call.
 567 *
 568 *	Make an APM call using the 32bit protected mode interface. The
 569 *	caller is responsible for knowing if APM BIOS is configured and
 570 *	enabled. This call can disable interrupts for a long period of
 571 *	time on some laptops.  The return value is in AH and the carry
 572 *	flag is loaded into AL.  If there is an error, then the error
 573 *	code is returned in AH (bits 8-15 of eax) and this function
 574 *	returns non-zero.
 575 *
 576 *	Note: this makes the call on the current CPU.
 577 */
 578static long __apm_bios_call(void *_call)
 579{
 580	APM_DECL_SEGS
 581	unsigned long		flags;
 582	int			cpu;
 583	struct desc_struct	save_desc_40;
 584	struct desc_struct	*gdt;
 585	struct apm_bios_call	*call = _call;
 586
 587	cpu = get_cpu();
 588	BUG_ON(cpu != 0);
 589	gdt = get_cpu_gdt_table(cpu);
 590	save_desc_40 = gdt[0x40 / 8];
 591	gdt[0x40 / 8] = bad_bios_desc;
 592
 593	apm_irq_save(flags);
 594	APM_DO_SAVE_SEGS;
 595	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 596			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 597			  &call->esi);
 598	APM_DO_RESTORE_SEGS;
 599	apm_irq_restore(flags);
 600	gdt[0x40 / 8] = save_desc_40;
 601	put_cpu();
 602
 603	return call->eax & 0xff;
 604}
 605
 606/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 607static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 608{
 609	int ret;
 610
 611	/* Don't bother with work_on_cpu in the common case, so we don't
 612	 * have to worry about OOM or overhead. */
 613	if (get_cpu() == 0) {
 614		ret = fn(call);
 615		put_cpu();
 616	} else {
 617		put_cpu();
 618		ret = work_on_cpu(0, fn, call);
 619	}
 620
 621	/* work_on_cpu can fail with -ENOMEM */
 622	if (ret < 0)
 623		call->err = ret;
 624	else
 625		call->err = (call->eax >> 8) & 0xff;
 626
 627	return ret;
 628}
 629
 630/**
 631 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 632 *	@call: the apm_bios_call registers.
 633 *
 634 *	If there is an error, it is returned in @call.err.
 635 */
 636static int apm_bios_call(struct apm_bios_call *call)
 637{
 638	return on_cpu0(__apm_bios_call, call);
 639}
 640
 641/**
 642 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 643 *	@_call: pointer to struct apm_bios_call.
 644 *
 645 *	Make a BIOS call that returns one value only, or just status.
 646 *	If there is an error, then the error code is returned in AH
 647 *	(bits 8-15 of eax) and this function returns non-zero (it can
 648 *	also return -ENOMEM). This is used for simpler BIOS operations.
 649 *	This call may hold interrupts off for a long time on some laptops.
 650 *
 651 *	Note: this makes the call on the current CPU.
 652 */
 653static long __apm_bios_call_simple(void *_call)
 654{
 655	u8			error;
 656	APM_DECL_SEGS
 657	unsigned long		flags;
 658	int			cpu;
 659	struct desc_struct	save_desc_40;
 660	struct desc_struct	*gdt;
 661	struct apm_bios_call	*call = _call;
 662
 663	cpu = get_cpu();
 664	BUG_ON(cpu != 0);
 665	gdt = get_cpu_gdt_table(cpu);
 666	save_desc_40 = gdt[0x40 / 8];
 667	gdt[0x40 / 8] = bad_bios_desc;
 668
 669	apm_irq_save(flags);
 670	APM_DO_SAVE_SEGS;
 671	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 672					 &call->eax);
 673	APM_DO_RESTORE_SEGS;
 674	apm_irq_restore(flags);
 675	gdt[0x40 / 8] = save_desc_40;
 676	put_cpu();
 677	return error;
 678}
 679
 680/**
 681 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 682 *	@func: APM function to invoke
 683 *	@ebx_in: EBX register value for BIOS call
 684 *	@ecx_in: ECX register value for BIOS call
 685 *	@eax: EAX register on return from the BIOS call
 686 *	@err: bits
 687 *
 688 *	Make a BIOS call that returns one value only, or just status.
 689 *	If there is an error, then the error code is returned in @err
 690 *	and this function returns non-zero. This is used for simpler
 691 *	BIOS operations.  This call may hold interrupts off for a long
 692 *	time on some laptops.
 693 */
 694static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 695				int *err)
 696{
 697	struct apm_bios_call call;
 698	int ret;
 699
 700	call.func = func;
 701	call.ebx = ebx_in;
 702	call.ecx = ecx_in;
 703
 704	ret = on_cpu0(__apm_bios_call_simple, &call);
 705	*eax = call.eax;
 706	*err = call.err;
 707	return ret;
 708}
 709
 710/**
 711 *	apm_driver_version	-	APM driver version
 712 *	@val:	loaded with the APM version on return
 713 *
 714 *	Retrieve the APM version supported by the BIOS. This is only
 715 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 716 *	probably present.
 717 *
 718 *	On entry val should point to a value indicating the APM driver
 719 *	version with the high byte being the major and the low byte the
 720 *	minor number both in BCD
 721 *
 722 *	On return it will hold the BIOS revision supported in the
 723 *	same format.
 724 */
 725
 726static int apm_driver_version(u_short *val)
 727{
 728	u32 eax;
 729	int err;
 730
 731	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 732		return err;
 733	*val = eax;
 734	return APM_SUCCESS;
 735}
 736
 737/**
 738 *	apm_get_event	-	get an APM event from the BIOS
 739 *	@event: pointer to the event
 740 *	@info: point to the event information
 741 *
 742 *	The APM BIOS provides a polled information for event
 743 *	reporting. The BIOS expects to be polled at least every second
 744 *	when events are pending. When a message is found the caller should
 745 *	poll until no more messages are present.  However, this causes
 746 *	problems on some laptops where a suspend event notification is
 747 *	not cleared until it is acknowledged.
 748 *
 749 *	Additional information is returned in the info pointer, providing
 750 *	that APM 1.2 is in use. If no messges are pending the value 0x80
 751 *	is returned (No power management events pending).
 752 */
 753static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 754{
 755	struct apm_bios_call call;
 756
 757	call.func = APM_FUNC_GET_EVENT;
 758	call.ebx = call.ecx = 0;
 759
 760	if (apm_bios_call(&call))
 761		return call.err;
 762
 763	*event = call.ebx;
 764	if (apm_info.connection_version < 0x0102)
 765		*info = ~0; /* indicate info not valid */
 766	else
 767		*info = call.ecx;
 768	return APM_SUCCESS;
 769}
 770
 771/**
 772 *	set_power_state	-	set the power management state
 773 *	@what: which items to transition
 774 *	@state: state to transition to
 775 *
 776 *	Request an APM change of state for one or more system devices. The
 777 *	processor state must be transitioned last of all. what holds the
 778 *	class of device in the upper byte and the device number (0xFF for
 779 *	all) for the object to be transitioned.
 780 *
 781 *	The state holds the state to transition to, which may in fact
 782 *	be an acceptance of a BIOS requested state change.
 783 */
 784
 785static int set_power_state(u_short what, u_short state)
 786{
 787	u32 eax;
 788	int err;
 789
 790	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 791		return err;
 792	return APM_SUCCESS;
 793}
 794
 795/**
 796 *	set_system_power_state - set system wide power state
 797 *	@state: which state to enter
 798 *
 799 *	Transition the entire system into a new APM power state.
 800 */
 801
 802static int set_system_power_state(u_short state)
 803{
 804	return set_power_state(APM_DEVICE_ALL, state);
 805}
 806
 807/**
 808 *	apm_do_idle	-	perform power saving
 809 *
 810 *	This function notifies the BIOS that the processor is (in the view
 811 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 812 *	to handle the idle request. On a success the function returns 1
 813 *	if the BIOS did clock slowing or 0 otherwise.
 814 */
 815
 816static int apm_do_idle(void)
 817{
 818	u32 eax;
 819	u8 ret = 0;
 820	int idled = 0;
 821	int polling;
 822	int err = 0;
 823
 824	polling = !!(current_thread_info()->status & TS_POLLING);
 825	if (polling) {
 826		current_thread_info()->status &= ~TS_POLLING;
 827		/*
 828		 * TS_POLLING-cleared state must be visible before we
 829		 * test NEED_RESCHED:
 830		 */
 831		smp_mb();
 832	}
 833	if (!need_resched()) {
 834		idled = 1;
 835		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 836	}
 837	if (polling)
 838		current_thread_info()->status |= TS_POLLING;
 839
 840	if (!idled)
 841		return 0;
 842
 843	if (ret) {
 844		static unsigned long t;
 845
 846		/* This always fails on some SMP boards running UP kernels.
 847		 * Only report the failure the first 5 times.
 848		 */
 849		if (++t < 5) {
 850			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 851			t = jiffies;
 852		}
 853		return -1;
 854	}
 855	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 856	return clock_slowed;
 857}
 858
 859/**
 860 *	apm_do_busy	-	inform the BIOS the CPU is busy
 861 *
 862 *	Request that the BIOS brings the CPU back to full performance.
 863 */
 864
 865static void apm_do_busy(void)
 866{
 867	u32 dummy;
 868	int err;
 869
 870	if (clock_slowed || ALWAYS_CALL_BUSY) {
 871		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 872		clock_slowed = 0;
 873	}
 874}
 875
 876/*
 877 * If no process has really been interested in
 878 * the CPU for some time, we want to call BIOS
 879 * power management - we probably want
 880 * to conserve power.
 881 */
 882#define IDLE_CALC_LIMIT	(HZ * 100)
 883#define IDLE_LEAKY_MAX	16
 884
 885static void (*original_pm_idle)(void) __read_mostly;
 886
 887/**
 888 * apm_cpu_idle		-	cpu idling for APM capable Linux
 889 *
 890 * This is the idling function the kernel executes when APM is available. It
 891 * tries to do BIOS powermanagement based on the average system idle time.
 892 * Furthermore it calls the system default idle routine.
 893 */
 894
 895static void apm_cpu_idle(void)
 
 896{
 897	static int use_apm_idle; /* = 0 */
 898	static unsigned int last_jiffies; /* = 0 */
 899	static unsigned int last_stime; /* = 0 */
 
 900
 901	int apm_idle_done = 0;
 902	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 903	unsigned int bucket;
 904
 905	WARN_ONCE(1, "deprecated apm_cpu_idle will be deleted in 2012");
 906recalc:
 
 907	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 908		use_apm_idle = 0;
 909		last_jiffies = jiffies;
 910		last_stime = current->stime;
 911	} else if (jiffies_since_last_check > idle_period) {
 912		unsigned int idle_percentage;
 913
 914		idle_percentage = current->stime - last_stime;
 915		idle_percentage *= 100;
 916		idle_percentage /= jiffies_since_last_check;
 917		use_apm_idle = (idle_percentage > idle_threshold);
 918		if (apm_info.forbid_idle)
 919			use_apm_idle = 0;
 920		last_jiffies = jiffies;
 921		last_stime = current->stime;
 922	}
 923
 
 
 
 924	bucket = IDLE_LEAKY_MAX;
 925
 926	while (!need_resched()) {
 927		if (use_apm_idle) {
 928			unsigned int t;
 929
 930			t = jiffies;
 931			switch (apm_do_idle()) {
 932			case 0:
 933				apm_idle_done = 1;
 934				if (t != jiffies) {
 935					if (bucket) {
 936						bucket = IDLE_LEAKY_MAX;
 937						continue;
 938					}
 939				} else if (bucket) {
 940					bucket--;
 941					continue;
 942				}
 943				break;
 944			case 1:
 945				apm_idle_done = 1;
 946				break;
 947			default: /* BIOS refused */
 948				break;
 949			}
 950		}
 951		if (original_pm_idle)
 952			original_pm_idle();
 953		else
 954			default_idle();
 955		local_irq_disable();
 956		jiffies_since_last_check = jiffies - last_jiffies;
 957		if (jiffies_since_last_check > idle_period)
 958			goto recalc;
 959	}
 960
 961	if (apm_idle_done)
 962		apm_do_busy();
 963
 964	local_irq_enable();
 965}
 966
 967/**
 968 *	apm_power_off	-	ask the BIOS to power off
 969 *
 970 *	Handle the power off sequence. This is the one piece of code we
 971 *	will execute even on SMP machines. In order to deal with BIOS
 972 *	bugs we support real mode APM BIOS power off calls. We also make
 973 *	the SMP call on CPU0 as some systems will only honour this call
 974 *	on their first cpu.
 975 */
 976
 977static void apm_power_off(void)
 978{
 979	/* Some bioses don't like being called from CPU != 0 */
 980	if (apm_info.realmode_power_off) {
 981		set_cpus_allowed_ptr(current, cpumask_of(0));
 982		machine_real_restart(MRR_APM);
 983	} else {
 984		(void)set_system_power_state(APM_STATE_OFF);
 985	}
 986}
 987
 988#ifdef CONFIG_APM_DO_ENABLE
 989
 990/**
 991 *	apm_enable_power_management - enable BIOS APM power management
 992 *	@enable: enable yes/no
 993 *
 994 *	Enable or disable the APM BIOS power services.
 995 */
 996
 997static int apm_enable_power_management(int enable)
 998{
 999	u32 eax;
1000	int err;
1001
1002	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1003		return APM_NOT_ENGAGED;
1004	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1005				 enable, &eax, &err))
1006		return err;
1007	if (enable)
1008		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1009	else
1010		apm_info.bios.flags |= APM_BIOS_DISABLED;
1011	return APM_SUCCESS;
1012}
1013#endif
1014
1015/**
1016 *	apm_get_power_status	-	get current power state
1017 *	@status: returned status
1018 *	@bat: battery info
1019 *	@life: estimated life
1020 *
1021 *	Obtain the current power status from the APM BIOS. We return a
1022 *	status which gives the rough battery status, and current power
1023 *	source. The bat value returned give an estimate as a percentage
1024 *	of life and a status value for the battery. The estimated life
1025 *	if reported is a lifetime in secodnds/minutes at current powwer
1026 *	consumption.
1027 */
1028
1029static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1030{
1031	struct apm_bios_call call;
1032
1033	call.func = APM_FUNC_GET_STATUS;
1034	call.ebx = APM_DEVICE_ALL;
1035	call.ecx = 0;
1036
1037	if (apm_info.get_power_status_broken)
1038		return APM_32_UNSUPPORTED;
1039	if (apm_bios_call(&call))
1040		return call.err;
1041	*status = call.ebx;
1042	*bat = call.ecx;
1043	if (apm_info.get_power_status_swabinminutes) {
1044		*life = swab16((u16)call.edx);
1045		*life |= 0x8000;
1046	} else
1047		*life = call.edx;
1048	return APM_SUCCESS;
1049}
1050
1051#if 0
1052static int apm_get_battery_status(u_short which, u_short *status,
1053				  u_short *bat, u_short *life, u_short *nbat)
1054{
1055	u32 eax;
1056	u32 ebx;
1057	u32 ecx;
1058	u32 edx;
1059	u32 esi;
1060
1061	if (apm_info.connection_version < 0x0102) {
1062		/* pretend we only have one battery. */
1063		if (which != 1)
1064			return APM_BAD_DEVICE;
1065		*nbat = 1;
1066		return apm_get_power_status(status, bat, life);
1067	}
1068
1069	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1070			  &ebx, &ecx, &edx, &esi))
1071		return (eax >> 8) & 0xff;
1072	*status = ebx;
1073	*bat = ecx;
1074	*life = edx;
1075	*nbat = esi;
1076	return APM_SUCCESS;
1077}
1078#endif
1079
1080/**
1081 *	apm_engage_power_management	-	enable PM on a device
1082 *	@device: identity of device
1083 *	@enable: on/off
1084 *
1085 *	Activate or deactive power management on either a specific device
1086 *	or the entire system (%APM_DEVICE_ALL).
1087 */
1088
1089static int apm_engage_power_management(u_short device, int enable)
1090{
1091	u32 eax;
1092	int err;
1093
1094	if ((enable == 0) && (device == APM_DEVICE_ALL)
1095	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1096		return APM_DISABLED;
1097	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1098				 &eax, &err))
1099		return err;
1100	if (device == APM_DEVICE_ALL) {
1101		if (enable)
1102			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1103		else
1104			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1105	}
1106	return APM_SUCCESS;
1107}
1108
1109#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1110
1111/**
1112 *	apm_console_blank	-	blank the display
1113 *	@blank: on/off
1114 *
1115 *	Attempt to blank the console, firstly by blanking just video device
1116 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1117 *	all video devices. Typically the BIOS will do laptop backlight and
1118 *	monitor powerdown for us.
1119 */
1120
1121static int apm_console_blank(int blank)
1122{
1123	int error = APM_NOT_ENGAGED; /* silence gcc */
1124	int i;
1125	u_short state;
1126	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1127
1128	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1129
1130	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1131		error = set_power_state(dev[i], state);
1132
1133		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1134			return 1;
1135
1136		if (error == APM_NOT_ENGAGED)
1137			break;
1138	}
1139
1140	if (error == APM_NOT_ENGAGED) {
1141		static int tried;
1142		int eng_error;
1143		if (tried++ == 0) {
1144			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1145			if (eng_error) {
1146				apm_error("set display", error);
1147				apm_error("engage interface", eng_error);
1148				return 0;
1149			} else
1150				return apm_console_blank(blank);
1151		}
1152	}
1153	apm_error("set display", error);
1154	return 0;
1155}
1156#endif
1157
1158static int queue_empty(struct apm_user *as)
1159{
1160	return as->event_head == as->event_tail;
1161}
1162
1163static apm_event_t get_queued_event(struct apm_user *as)
1164{
1165	if (++as->event_tail >= APM_MAX_EVENTS)
1166		as->event_tail = 0;
1167	return as->events[as->event_tail];
1168}
1169
1170static void queue_event(apm_event_t event, struct apm_user *sender)
1171{
1172	struct apm_user *as;
1173
1174	spin_lock(&user_list_lock);
1175	if (user_list == NULL)
1176		goto out;
1177	for (as = user_list; as != NULL; as = as->next) {
1178		if ((as == sender) || (!as->reader))
1179			continue;
1180		if (++as->event_head >= APM_MAX_EVENTS)
1181			as->event_head = 0;
1182
1183		if (as->event_head == as->event_tail) {
1184			static int notified;
1185
1186			if (notified++ == 0)
1187			    printk(KERN_ERR "apm: an event queue overflowed\n");
1188			if (++as->event_tail >= APM_MAX_EVENTS)
1189				as->event_tail = 0;
1190		}
1191		as->events[as->event_head] = event;
1192		if (!as->suser || !as->writer)
1193			continue;
1194		switch (event) {
1195		case APM_SYS_SUSPEND:
1196		case APM_USER_SUSPEND:
1197			as->suspends_pending++;
1198			suspends_pending++;
1199			break;
1200
1201		case APM_SYS_STANDBY:
1202		case APM_USER_STANDBY:
1203			as->standbys_pending++;
1204			standbys_pending++;
1205			break;
1206		}
1207	}
1208	wake_up_interruptible(&apm_waitqueue);
1209out:
1210	spin_unlock(&user_list_lock);
1211}
1212
1213static void reinit_timer(void)
1214{
1215#ifdef INIT_TIMER_AFTER_SUSPEND
1216	unsigned long flags;
1217
1218	raw_spin_lock_irqsave(&i8253_lock, flags);
1219	/* set the clock to HZ */
1220	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1221	udelay(10);
1222	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1223	udelay(10);
1224	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1225	udelay(10);
1226	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1227#endif
1228}
1229
1230static int suspend(int vetoable)
1231{
1232	int err;
1233	struct apm_user	*as;
1234
1235	dpm_suspend_start(PMSG_SUSPEND);
1236	dpm_suspend_end(PMSG_SUSPEND);
1237
1238	local_irq_disable();
1239	syscore_suspend();
1240
1241	local_irq_enable();
1242
1243	save_processor_state();
1244	err = set_system_power_state(APM_STATE_SUSPEND);
1245	ignore_normal_resume = 1;
1246	restore_processor_state();
1247
1248	local_irq_disable();
1249	reinit_timer();
1250
1251	if (err == APM_NO_ERROR)
1252		err = APM_SUCCESS;
1253	if (err != APM_SUCCESS)
1254		apm_error("suspend", err);
1255	err = (err == APM_SUCCESS) ? 0 : -EIO;
1256
1257	syscore_resume();
1258	local_irq_enable();
1259
1260	dpm_resume_start(PMSG_RESUME);
1261	dpm_resume_end(PMSG_RESUME);
1262
1263	queue_event(APM_NORMAL_RESUME, NULL);
1264	spin_lock(&user_list_lock);
1265	for (as = user_list; as != NULL; as = as->next) {
1266		as->suspend_wait = 0;
1267		as->suspend_result = err;
1268	}
1269	spin_unlock(&user_list_lock);
1270	wake_up_interruptible(&apm_suspend_waitqueue);
1271	return err;
1272}
1273
1274static void standby(void)
1275{
1276	int err;
1277
1278	dpm_suspend_end(PMSG_SUSPEND);
1279
1280	local_irq_disable();
1281	syscore_suspend();
1282	local_irq_enable();
1283
1284	err = set_system_power_state(APM_STATE_STANDBY);
1285	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1286		apm_error("standby", err);
1287
1288	local_irq_disable();
1289	syscore_resume();
1290	local_irq_enable();
1291
1292	dpm_resume_start(PMSG_RESUME);
1293}
1294
1295static apm_event_t get_event(void)
1296{
1297	int error;
1298	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1299	apm_eventinfo_t	info;
1300
1301	static int notified;
1302
1303	/* we don't use the eventinfo */
1304	error = apm_get_event(&event, &info);
1305	if (error == APM_SUCCESS)
1306		return event;
1307
1308	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1309		apm_error("get_event", error);
1310
1311	return 0;
1312}
1313
1314static void check_events(void)
1315{
1316	apm_event_t event;
1317	static unsigned long last_resume;
1318	static int ignore_bounce;
1319
1320	while ((event = get_event()) != 0) {
1321		if (debug) {
1322			if (event <= NR_APM_EVENT_NAME)
1323				printk(KERN_DEBUG "apm: received %s notify\n",
1324				       apm_event_name[event - 1]);
1325			else
1326				printk(KERN_DEBUG "apm: received unknown "
1327				       "event 0x%02x\n", event);
1328		}
1329		if (ignore_bounce
1330		    && (time_after(jiffies, last_resume + bounce_interval)))
1331			ignore_bounce = 0;
1332
1333		switch (event) {
1334		case APM_SYS_STANDBY:
1335		case APM_USER_STANDBY:
1336			queue_event(event, NULL);
1337			if (standbys_pending <= 0)
1338				standby();
1339			break;
1340
1341		case APM_USER_SUSPEND:
1342#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1343			if (apm_info.connection_version > 0x100)
1344				set_system_power_state(APM_STATE_REJECT);
1345			break;
1346#endif
1347		case APM_SYS_SUSPEND:
1348			if (ignore_bounce) {
1349				if (apm_info.connection_version > 0x100)
1350					set_system_power_state(APM_STATE_REJECT);
1351				break;
1352			}
1353			/*
1354			 * If we are already processing a SUSPEND,
1355			 * then further SUSPEND events from the BIOS
1356			 * will be ignored.  We also return here to
1357			 * cope with the fact that the Thinkpads keep
1358			 * sending a SUSPEND event until something else
1359			 * happens!
1360			 */
1361			if (ignore_sys_suspend)
1362				return;
1363			ignore_sys_suspend = 1;
1364			queue_event(event, NULL);
1365			if (suspends_pending <= 0)
1366				(void) suspend(1);
1367			break;
1368
1369		case APM_NORMAL_RESUME:
1370		case APM_CRITICAL_RESUME:
1371		case APM_STANDBY_RESUME:
1372			ignore_sys_suspend = 0;
1373			last_resume = jiffies;
1374			ignore_bounce = 1;
1375			if ((event != APM_NORMAL_RESUME)
1376			    || (ignore_normal_resume == 0)) {
1377				dpm_resume_end(PMSG_RESUME);
1378				queue_event(event, NULL);
1379			}
1380			ignore_normal_resume = 0;
1381			break;
1382
1383		case APM_CAPABILITY_CHANGE:
1384		case APM_LOW_BATTERY:
1385		case APM_POWER_STATUS_CHANGE:
1386			queue_event(event, NULL);
1387			/* If needed, notify drivers here */
1388			break;
1389
1390		case APM_UPDATE_TIME:
1391			break;
1392
1393		case APM_CRITICAL_SUSPEND:
1394			/*
1395			 * We are not allowed to reject a critical suspend.
1396			 */
1397			(void)suspend(0);
1398			break;
1399		}
1400	}
1401}
1402
1403static void apm_event_handler(void)
1404{
1405	static int pending_count = 4;
1406	int err;
1407
1408	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1409		if ((apm_info.connection_version > 0x100) &&
1410		    (pending_count-- <= 0)) {
1411			pending_count = 4;
1412			if (debug)
1413				printk(KERN_DEBUG "apm: setting state busy\n");
1414			err = set_system_power_state(APM_STATE_BUSY);
1415			if (err)
1416				apm_error("busy", err);
1417		}
1418	} else
1419		pending_count = 4;
1420	check_events();
1421}
1422
1423/*
1424 * This is the APM thread main loop.
1425 */
1426
1427static void apm_mainloop(void)
1428{
1429	DECLARE_WAITQUEUE(wait, current);
1430
1431	add_wait_queue(&apm_waitqueue, &wait);
1432	set_current_state(TASK_INTERRUPTIBLE);
1433	for (;;) {
1434		schedule_timeout(APM_CHECK_TIMEOUT);
1435		if (kthread_should_stop())
1436			break;
1437		/*
1438		 * Ok, check all events, check for idle (and mark us sleeping
1439		 * so as not to count towards the load average)..
1440		 */
1441		set_current_state(TASK_INTERRUPTIBLE);
1442		apm_event_handler();
1443	}
1444	remove_wait_queue(&apm_waitqueue, &wait);
1445}
1446
1447static int check_apm_user(struct apm_user *as, const char *func)
1448{
1449	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1450		printk(KERN_ERR "apm: %s passed bad filp\n", func);
1451		return 1;
1452	}
1453	return 0;
1454}
1455
1456static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1457{
1458	struct apm_user *as;
1459	int i;
1460	apm_event_t event;
1461
1462	as = fp->private_data;
1463	if (check_apm_user(as, "read"))
1464		return -EIO;
1465	if ((int)count < sizeof(apm_event_t))
1466		return -EINVAL;
1467	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1468		return -EAGAIN;
1469	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1470	i = count;
1471	while ((i >= sizeof(event)) && !queue_empty(as)) {
1472		event = get_queued_event(as);
1473		if (copy_to_user(buf, &event, sizeof(event))) {
1474			if (i < count)
1475				break;
1476			return -EFAULT;
1477		}
1478		switch (event) {
1479		case APM_SYS_SUSPEND:
1480		case APM_USER_SUSPEND:
1481			as->suspends_read++;
1482			break;
1483
1484		case APM_SYS_STANDBY:
1485		case APM_USER_STANDBY:
1486			as->standbys_read++;
1487			break;
1488		}
1489		buf += sizeof(event);
1490		i -= sizeof(event);
1491	}
1492	if (i < count)
1493		return count - i;
1494	if (signal_pending(current))
1495		return -ERESTARTSYS;
1496	return 0;
1497}
1498
1499static unsigned int do_poll(struct file *fp, poll_table *wait)
1500{
1501	struct apm_user *as;
1502
1503	as = fp->private_data;
1504	if (check_apm_user(as, "poll"))
1505		return 0;
1506	poll_wait(fp, &apm_waitqueue, wait);
1507	if (!queue_empty(as))
1508		return POLLIN | POLLRDNORM;
1509	return 0;
1510}
1511
1512static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1513{
1514	struct apm_user *as;
1515	int ret;
1516
1517	as = filp->private_data;
1518	if (check_apm_user(as, "ioctl"))
1519		return -EIO;
1520	if (!as->suser || !as->writer)
1521		return -EPERM;
1522	switch (cmd) {
1523	case APM_IOC_STANDBY:
1524		mutex_lock(&apm_mutex);
1525		if (as->standbys_read > 0) {
1526			as->standbys_read--;
1527			as->standbys_pending--;
1528			standbys_pending--;
1529		} else
1530			queue_event(APM_USER_STANDBY, as);
1531		if (standbys_pending <= 0)
1532			standby();
1533		mutex_unlock(&apm_mutex);
1534		break;
1535	case APM_IOC_SUSPEND:
1536		mutex_lock(&apm_mutex);
1537		if (as->suspends_read > 0) {
1538			as->suspends_read--;
1539			as->suspends_pending--;
1540			suspends_pending--;
1541		} else
1542			queue_event(APM_USER_SUSPEND, as);
1543		if (suspends_pending <= 0) {
1544			ret = suspend(1);
1545			mutex_unlock(&apm_mutex);
1546		} else {
1547			as->suspend_wait = 1;
1548			mutex_unlock(&apm_mutex);
1549			wait_event_interruptible(apm_suspend_waitqueue,
1550					as->suspend_wait == 0);
1551			ret = as->suspend_result;
1552		}
1553		return ret;
1554	default:
1555		return -ENOTTY;
1556	}
1557	return 0;
1558}
1559
1560static int do_release(struct inode *inode, struct file *filp)
1561{
1562	struct apm_user *as;
1563
1564	as = filp->private_data;
1565	if (check_apm_user(as, "release"))
1566		return 0;
1567	filp->private_data = NULL;
1568	if (as->standbys_pending > 0) {
1569		standbys_pending -= as->standbys_pending;
1570		if (standbys_pending <= 0)
1571			standby();
1572	}
1573	if (as->suspends_pending > 0) {
1574		suspends_pending -= as->suspends_pending;
1575		if (suspends_pending <= 0)
1576			(void) suspend(1);
1577	}
1578	spin_lock(&user_list_lock);
1579	if (user_list == as)
1580		user_list = as->next;
1581	else {
1582		struct apm_user *as1;
1583
1584		for (as1 = user_list;
1585		     (as1 != NULL) && (as1->next != as);
1586		     as1 = as1->next)
1587			;
1588		if (as1 == NULL)
1589			printk(KERN_ERR "apm: filp not in user list\n");
1590		else
1591			as1->next = as->next;
1592	}
1593	spin_unlock(&user_list_lock);
1594	kfree(as);
1595	return 0;
1596}
1597
1598static int do_open(struct inode *inode, struct file *filp)
1599{
1600	struct apm_user *as;
1601
1602	as = kmalloc(sizeof(*as), GFP_KERNEL);
1603	if (as == NULL) {
1604		printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1605		       sizeof(*as));
1606		return -ENOMEM;
1607	}
1608	as->magic = APM_BIOS_MAGIC;
1609	as->event_tail = as->event_head = 0;
1610	as->suspends_pending = as->standbys_pending = 0;
1611	as->suspends_read = as->standbys_read = 0;
1612	/*
1613	 * XXX - this is a tiny bit broken, when we consider BSD
1614	 * process accounting. If the device is opened by root, we
1615	 * instantly flag that we used superuser privs. Who knows,
1616	 * we might close the device immediately without doing a
1617	 * privileged operation -- cevans
1618	 */
1619	as->suser = capable(CAP_SYS_ADMIN);
1620	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1621	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1622	spin_lock(&user_list_lock);
1623	as->next = user_list;
1624	user_list = as;
1625	spin_unlock(&user_list_lock);
1626	filp->private_data = as;
1627	return 0;
1628}
1629
1630static int proc_apm_show(struct seq_file *m, void *v)
1631{
1632	unsigned short	bx;
1633	unsigned short	cx;
1634	unsigned short	dx;
1635	int		error;
1636	unsigned short  ac_line_status = 0xff;
1637	unsigned short  battery_status = 0xff;
1638	unsigned short  battery_flag   = 0xff;
1639	int		percentage     = -1;
1640	int             time_units     = -1;
1641	char            *units         = "?";
1642
1643	if ((num_online_cpus() == 1) &&
1644	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1645		ac_line_status = (bx >> 8) & 0xff;
1646		battery_status = bx & 0xff;
1647		if ((cx & 0xff) != 0xff)
1648			percentage = cx & 0xff;
1649
1650		if (apm_info.connection_version > 0x100) {
1651			battery_flag = (cx >> 8) & 0xff;
1652			if (dx != 0xffff) {
1653				units = (dx & 0x8000) ? "min" : "sec";
1654				time_units = dx & 0x7fff;
1655			}
1656		}
1657	}
1658	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1659	   from the Get Power Status (0x0a) call unless otherwise noted.
1660
1661	   0) Linux driver version (this will change if format changes)
1662	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1663	   2) APM flags from APM Installation Check (0x00):
1664	      bit 0: APM_16_BIT_SUPPORT
1665	      bit 1: APM_32_BIT_SUPPORT
1666	      bit 2: APM_IDLE_SLOWS_CLOCK
1667	      bit 3: APM_BIOS_DISABLED
1668	      bit 4: APM_BIOS_DISENGAGED
1669	   3) AC line status
1670	      0x00: Off-line
1671	      0x01: On-line
1672	      0x02: On backup power (BIOS >= 1.1 only)
1673	      0xff: Unknown
1674	   4) Battery status
1675	      0x00: High
1676	      0x01: Low
1677	      0x02: Critical
1678	      0x03: Charging
1679	      0x04: Selected battery not present (BIOS >= 1.2 only)
1680	      0xff: Unknown
1681	   5) Battery flag
1682	      bit 0: High
1683	      bit 1: Low
1684	      bit 2: Critical
1685	      bit 3: Charging
1686	      bit 7: No system battery
1687	      0xff: Unknown
1688	   6) Remaining battery life (percentage of charge):
1689	      0-100: valid
1690	      -1: Unknown
1691	   7) Remaining battery life (time units):
1692	      Number of remaining minutes or seconds
1693	      -1: Unknown
1694	   8) min = minutes; sec = seconds */
1695
1696	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1697		   driver_version,
1698		   (apm_info.bios.version >> 8) & 0xff,
1699		   apm_info.bios.version & 0xff,
1700		   apm_info.bios.flags,
1701		   ac_line_status,
1702		   battery_status,
1703		   battery_flag,
1704		   percentage,
1705		   time_units,
1706		   units);
1707	return 0;
1708}
1709
1710static int proc_apm_open(struct inode *inode, struct file *file)
1711{
1712	return single_open(file, proc_apm_show, NULL);
1713}
1714
1715static const struct file_operations apm_file_ops = {
1716	.owner		= THIS_MODULE,
1717	.open		= proc_apm_open,
1718	.read		= seq_read,
1719	.llseek		= seq_lseek,
1720	.release	= single_release,
1721};
1722
1723static int apm(void *unused)
1724{
1725	unsigned short	bx;
1726	unsigned short	cx;
1727	unsigned short	dx;
1728	int		error;
1729	char 		*power_stat;
1730	char 		*bat_stat;
1731
1732	/* 2002/08/01 - WT
1733	 * This is to avoid random crashes at boot time during initialization
1734	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1735	 * Some bioses don't like being called from CPU != 0.
1736	 * Method suggested by Ingo Molnar.
1737	 */
1738	set_cpus_allowed_ptr(current, cpumask_of(0));
1739	BUG_ON(smp_processor_id() != 0);
1740
1741	if (apm_info.connection_version == 0) {
1742		apm_info.connection_version = apm_info.bios.version;
1743		if (apm_info.connection_version > 0x100) {
1744			/*
1745			 * We only support BIOSs up to version 1.2
1746			 */
1747			if (apm_info.connection_version > 0x0102)
1748				apm_info.connection_version = 0x0102;
1749			error = apm_driver_version(&apm_info.connection_version);
1750			if (error != APM_SUCCESS) {
1751				apm_error("driver version", error);
1752				/* Fall back to an APM 1.0 connection. */
1753				apm_info.connection_version = 0x100;
1754			}
1755		}
1756	}
1757
1758	if (debug)
1759		printk(KERN_INFO "apm: Connection version %d.%d\n",
1760			(apm_info.connection_version >> 8) & 0xff,
1761			apm_info.connection_version & 0xff);
1762
1763#ifdef CONFIG_APM_DO_ENABLE
1764	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1765		/*
1766		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1767		 * is booted with PM disabled but not in the docking station.
1768		 * Unfortunate ...
1769		 */
1770		error = apm_enable_power_management(1);
1771		if (error) {
1772			apm_error("enable power management", error);
1773			return -1;
1774		}
1775	}
1776#endif
1777
1778	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1779	    && (apm_info.connection_version > 0x0100)) {
1780		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1781		if (error) {
1782			apm_error("engage power management", error);
1783			return -1;
1784		}
1785	}
1786
1787	if (debug && (num_online_cpus() == 1 || smp)) {
1788		error = apm_get_power_status(&bx, &cx, &dx);
1789		if (error)
1790			printk(KERN_INFO "apm: power status not available\n");
1791		else {
1792			switch ((bx >> 8) & 0xff) {
1793			case 0:
1794				power_stat = "off line";
1795				break;
1796			case 1:
1797				power_stat = "on line";
1798				break;
1799			case 2:
1800				power_stat = "on backup power";
1801				break;
1802			default:
1803				power_stat = "unknown";
1804				break;
1805			}
1806			switch (bx & 0xff) {
1807			case 0:
1808				bat_stat = "high";
1809				break;
1810			case 1:
1811				bat_stat = "low";
1812				break;
1813			case 2:
1814				bat_stat = "critical";
1815				break;
1816			case 3:
1817				bat_stat = "charging";
1818				break;
1819			default:
1820				bat_stat = "unknown";
1821				break;
1822			}
1823			printk(KERN_INFO
1824			       "apm: AC %s, battery status %s, battery life ",
1825			       power_stat, bat_stat);
1826			if ((cx & 0xff) == 0xff)
1827				printk("unknown\n");
1828			else
1829				printk("%d%%\n", cx & 0xff);
1830			if (apm_info.connection_version > 0x100) {
1831				printk(KERN_INFO
1832				       "apm: battery flag 0x%02x, battery life ",
1833				       (cx >> 8) & 0xff);
1834				if (dx == 0xffff)
1835					printk("unknown\n");
1836				else
1837					printk("%d %s\n", dx & 0x7fff,
1838					       (dx & 0x8000) ?
1839					       "minutes" : "seconds");
1840			}
1841		}
1842	}
1843
1844	/* Install our power off handler.. */
1845	if (power_off)
1846		pm_power_off = apm_power_off;
1847
1848	if (num_online_cpus() == 1 || smp) {
1849#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1850		console_blank_hook = apm_console_blank;
1851#endif
1852		apm_mainloop();
1853#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1854		console_blank_hook = NULL;
1855#endif
1856	}
1857
1858	return 0;
1859}
1860
1861#ifndef MODULE
1862static int __init apm_setup(char *str)
1863{
1864	int invert;
1865
1866	while ((str != NULL) && (*str != '\0')) {
1867		if (strncmp(str, "off", 3) == 0)
1868			apm_disabled = 1;
1869		if (strncmp(str, "on", 2) == 0)
1870			apm_disabled = 0;
1871		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1872		    (strncmp(str, "bounce_interval=", 16) == 0))
1873			bounce_interval = simple_strtol(str + 16, NULL, 0);
1874		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1875		    (strncmp(str, "idle_threshold=", 15) == 0))
1876			idle_threshold = simple_strtol(str + 15, NULL, 0);
1877		if ((strncmp(str, "idle-period=", 12) == 0) ||
1878		    (strncmp(str, "idle_period=", 12) == 0))
1879			idle_period = simple_strtol(str + 12, NULL, 0);
1880		invert = (strncmp(str, "no-", 3) == 0) ||
1881			(strncmp(str, "no_", 3) == 0);
1882		if (invert)
1883			str += 3;
1884		if (strncmp(str, "debug", 5) == 0)
1885			debug = !invert;
1886		if ((strncmp(str, "power-off", 9) == 0) ||
1887		    (strncmp(str, "power_off", 9) == 0))
1888			power_off = !invert;
1889		if (strncmp(str, "smp", 3) == 0) {
1890			smp = !invert;
1891			idle_threshold = 100;
1892		}
1893		if ((strncmp(str, "allow-ints", 10) == 0) ||
1894		    (strncmp(str, "allow_ints", 10) == 0))
1895			apm_info.allow_ints = !invert;
1896		if ((strncmp(str, "broken-psr", 10) == 0) ||
1897		    (strncmp(str, "broken_psr", 10) == 0))
1898			apm_info.get_power_status_broken = !invert;
1899		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1900		    (strncmp(str, "realmode_power_off", 18) == 0))
1901			apm_info.realmode_power_off = !invert;
1902		str = strchr(str, ',');
1903		if (str != NULL)
1904			str += strspn(str, ", \t");
1905	}
1906	return 1;
1907}
1908
1909__setup("apm=", apm_setup);
1910#endif
1911
1912static const struct file_operations apm_bios_fops = {
1913	.owner		= THIS_MODULE,
1914	.read		= do_read,
1915	.poll		= do_poll,
1916	.unlocked_ioctl	= do_ioctl,
1917	.open		= do_open,
1918	.release	= do_release,
1919	.llseek		= noop_llseek,
1920};
1921
1922static struct miscdevice apm_device = {
1923	APM_MINOR_DEV,
1924	"apm_bios",
1925	&apm_bios_fops
1926};
1927
1928
1929/* Simple "print if true" callback */
1930static int __init print_if_true(const struct dmi_system_id *d)
1931{
1932	printk("%s\n", d->ident);
1933	return 0;
1934}
1935
1936/*
1937 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1938 * disabled before the suspend. Linux used to get terribly confused by that.
1939 */
1940static int __init broken_ps2_resume(const struct dmi_system_id *d)
1941{
1942	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1943	       "workaround hopefully not needed.\n", d->ident);
1944	return 0;
1945}
1946
1947/* Some bioses have a broken protected mode poweroff and need to use realmode */
1948static int __init set_realmode_power_off(const struct dmi_system_id *d)
1949{
1950	if (apm_info.realmode_power_off == 0) {
1951		apm_info.realmode_power_off = 1;
1952		printk(KERN_INFO "%s bios detected. "
1953		       "Using realmode poweroff only.\n", d->ident);
1954	}
1955	return 0;
1956}
1957
1958/* Some laptops require interrupts to be enabled during APM calls */
1959static int __init set_apm_ints(const struct dmi_system_id *d)
1960{
1961	if (apm_info.allow_ints == 0) {
1962		apm_info.allow_ints = 1;
1963		printk(KERN_INFO "%s machine detected. "
1964		       "Enabling interrupts during APM calls.\n", d->ident);
1965	}
1966	return 0;
1967}
1968
1969/* Some APM bioses corrupt memory or just plain do not work */
1970static int __init apm_is_horked(const struct dmi_system_id *d)
1971{
1972	if (apm_info.disabled == 0) {
1973		apm_info.disabled = 1;
1974		printk(KERN_INFO "%s machine detected. "
1975		       "Disabling APM.\n", d->ident);
1976	}
1977	return 0;
1978}
1979
1980static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1981{
1982	if (apm_info.disabled == 0) {
1983		apm_info.disabled = 1;
1984		printk(KERN_INFO "%s machine detected. "
1985		       "Disabling APM.\n", d->ident);
1986		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1987		printk(KERN_INFO "download from support.intel.com\n");
1988	}
1989	return 0;
1990}
1991
1992/* Some APM bioses hang on APM idle calls */
1993static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1994{
1995	if (apm_info.forbid_idle == 0) {
1996		apm_info.forbid_idle = 1;
1997		printk(KERN_INFO "%s machine detected. "
1998		       "Disabling APM idle calls.\n", d->ident);
1999	}
2000	return 0;
2001}
2002
2003/*
2004 *  Check for clue free BIOS implementations who use
2005 *  the following QA technique
2006 *
2007 *      [ Write BIOS Code ]<------
2008 *               |                ^
2009 *      < Does it Compile >----N--
2010 *               |Y               ^
2011 *	< Does it Boot Win98 >-N--
2012 *               |Y
2013 *           [Ship It]
2014 *
2015 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2016 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2017 */
2018static int __init broken_apm_power(const struct dmi_system_id *d)
2019{
2020	apm_info.get_power_status_broken = 1;
2021	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2022	       "disabling power status reporting.\n");
2023	return 0;
2024}
2025
2026/*
2027 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2028 * have this problem).
2029 */
2030static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2031{
2032	apm_info.get_power_status_swabinminutes = 1;
2033	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2034	       "in minutes and wrong byte order.\n");
2035	return 0;
2036}
2037
2038static struct dmi_system_id __initdata apm_dmi_table[] = {
2039	{
2040		print_if_true,
2041		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2042		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2043			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2044	},
2045	{	/* Handle problems with APM on the C600 */
2046		broken_ps2_resume, "Dell Latitude C600",
2047		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2048			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2049	},
2050	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2051		set_apm_ints, "Dell Latitude",
2052		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2053			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2054	},
2055	{	/* APM crashes */
2056		apm_is_horked, "Dell Inspiron 2500",
2057		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2058			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2059			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2060			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2061	},
2062	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2063		set_apm_ints, "Dell Inspiron", {
2064			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2065			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2066	},
2067	{	/* Handle problems with APM on Inspiron 5000e */
2068		broken_apm_power, "Dell Inspiron 5000e",
2069		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2070			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2071			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2072	},
2073	{	/* Handle problems with APM on Inspiron 2500 */
2074		broken_apm_power, "Dell Inspiron 2500",
2075		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2076			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2077			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2078	},
2079	{	/* APM crashes */
2080		apm_is_horked, "Dell Dimension 4100",
2081		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2082			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2083			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2084			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2085	},
2086	{	/* Allow interrupts during suspend on Compaq Laptops*/
2087		set_apm_ints, "Compaq 12XL125",
2088		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2089			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2090			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2091			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2092	},
2093	{	/* Allow interrupts during APM or the clock goes slow */
2094		set_apm_ints, "ASUSTeK",
2095		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2096			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2097	},
2098	{	/* APM blows on shutdown */
2099		apm_is_horked, "ABIT KX7-333[R]",
2100		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2101			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2102	},
2103	{	/* APM crashes */
2104		apm_is_horked, "Trigem Delhi3",
2105		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2106			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2107	},
2108	{	/* APM crashes */
2109		apm_is_horked, "Fujitsu-Siemens",
2110		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2111			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2112	},
2113	{	/* APM crashes */
2114		apm_is_horked_d850md, "Intel D850MD",
2115		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2116			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2117	},
2118	{	/* APM crashes */
2119		apm_is_horked, "Intel D810EMO",
2120		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2121			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2122	},
2123	{	/* APM crashes */
2124		apm_is_horked, "Dell XPS-Z",
2125		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2126			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2127			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2128	},
2129	{	/* APM crashes */
2130		apm_is_horked, "Sharp PC-PJ/AX",
2131		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2132			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2133			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2134			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2135	},
2136	{	/* APM crashes */
2137		apm_is_horked, "Dell Inspiron 2500",
2138		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2139			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2140			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2141			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2142	},
2143	{	/* APM idle hangs */
2144		apm_likes_to_melt, "Jabil AMD",
2145		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2146			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2147	},
2148	{	/* APM idle hangs */
2149		apm_likes_to_melt, "AMI Bios",
2150		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2151			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2152	},
2153	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2154		swab_apm_power_in_minutes, "Sony VAIO",
2155		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2156			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2157			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2158	},
2159	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2160		swab_apm_power_in_minutes, "Sony VAIO",
2161		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2162			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2163			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2164	},
2165	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2166		swab_apm_power_in_minutes, "Sony VAIO",
2167		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2168			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2169			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2170	},
2171	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2172		swab_apm_power_in_minutes, "Sony VAIO",
2173		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2174			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2175			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2176	},
2177	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2178		swab_apm_power_in_minutes, "Sony VAIO",
2179		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2180			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2181			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2182	},
2183	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2184		swab_apm_power_in_minutes, "Sony VAIO",
2185		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2186			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2187			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2188	},
2189	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2190		swab_apm_power_in_minutes, "Sony VAIO",
2191		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2192			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2193			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2194	},
2195	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2196		swab_apm_power_in_minutes, "Sony VAIO",
2197		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2198			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2199			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2200	},
2201	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2202		swab_apm_power_in_minutes, "Sony VAIO",
2203		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2204			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2205			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2206	},
2207	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2208		swab_apm_power_in_minutes, "Sony VAIO",
2209		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2211			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2212	},
2213
2214	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2215		swab_apm_power_in_minutes, "Sony VAIO",
2216		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2217			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2218			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2219	},
2220	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2221		swab_apm_power_in_minutes, "Sony VAIO",
2222		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2223			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2224			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2225	},
2226	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2227		swab_apm_power_in_minutes, "Sony VAIO",
2228		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2229			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2230			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2231	},
2232	{	/* broken PM poweroff bios */
2233		set_realmode_power_off, "Award Software v4.60 PGMA",
2234		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2235			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2236			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2237	},
2238
2239	/* Generic per vendor APM settings  */
2240
2241	{	/* Allow interrupts during suspend on IBM laptops */
2242		set_apm_ints, "IBM",
2243		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2244	},
2245
2246	{ }
2247};
2248
2249/*
2250 * Just start the APM thread. We do NOT want to do APM BIOS
2251 * calls from anything but the APM thread, if for no other reason
2252 * than the fact that we don't trust the APM BIOS. This way,
2253 * most common APM BIOS problems that lead to protection errors
2254 * etc will have at least some level of being contained...
2255 *
2256 * In short, if something bad happens, at least we have a choice
2257 * of just killing the apm thread..
2258 */
2259static int __init apm_init(void)
2260{
2261	struct desc_struct *gdt;
2262	int err;
2263
2264	dmi_check_system(apm_dmi_table);
2265
2266	if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2267		printk(KERN_INFO "apm: BIOS not found.\n");
2268		return -ENODEV;
2269	}
2270	printk(KERN_INFO
2271	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2272	       ((apm_info.bios.version >> 8) & 0xff),
2273	       (apm_info.bios.version & 0xff),
2274	       apm_info.bios.flags,
2275	       driver_version);
2276	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2277		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2278		return -ENODEV;
2279	}
2280
2281	if (allow_ints)
2282		apm_info.allow_ints = 1;
2283	if (broken_psr)
2284		apm_info.get_power_status_broken = 1;
2285	if (realmode_power_off)
2286		apm_info.realmode_power_off = 1;
2287	/* User can override, but default is to trust DMI */
2288	if (apm_disabled != -1)
2289		apm_info.disabled = apm_disabled;
2290
2291	/*
2292	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2293	 * but is reportedly a 1.0 BIOS.
2294	 */
2295	if (apm_info.bios.version == 0x001)
2296		apm_info.bios.version = 0x100;
2297
2298	/* BIOS < 1.2 doesn't set cseg_16_len */
2299	if (apm_info.bios.version < 0x102)
2300		apm_info.bios.cseg_16_len = 0; /* 64k */
2301
2302	if (debug) {
2303		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2304			apm_info.bios.cseg, apm_info.bios.offset,
2305			apm_info.bios.cseg_16, apm_info.bios.dseg);
2306		if (apm_info.bios.version > 0x100)
2307			printk(" cseg len %x, dseg len %x",
2308				apm_info.bios.cseg_len,
2309				apm_info.bios.dseg_len);
2310		if (apm_info.bios.version > 0x101)
2311			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2312		printk("\n");
2313	}
2314
2315	if (apm_info.disabled) {
2316		printk(KERN_NOTICE "apm: disabled on user request.\n");
2317		return -ENODEV;
2318	}
2319	if ((num_online_cpus() > 1) && !power_off && !smp) {
2320		printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2321		apm_info.disabled = 1;
2322		return -ENODEV;
2323	}
2324	if (!acpi_disabled) {
2325		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2326		apm_info.disabled = 1;
2327		return -ENODEV;
2328	}
2329
2330	/*
2331	 * Set up the long jump entry point to the APM BIOS, which is called
2332	 * from inline assembly.
2333	 */
2334	apm_bios_entry.offset = apm_info.bios.offset;
2335	apm_bios_entry.segment = APM_CS;
2336
2337	/*
2338	 * The APM 1.1 BIOS is supposed to provide limit information that it
2339	 * recognizes.  Many machines do this correctly, but many others do
2340	 * not restrict themselves to their claimed limit.  When this happens,
2341	 * they will cause a segmentation violation in the kernel at boot time.
2342	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2343	 *
2344	 * Note we only set APM segments on CPU zero, since we pin the APM
2345	 * code to that CPU.
2346	 */
2347	gdt = get_cpu_gdt_table(0);
2348	set_desc_base(&gdt[APM_CS >> 3],
2349		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2350	set_desc_base(&gdt[APM_CS_16 >> 3],
2351		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2352	set_desc_base(&gdt[APM_DS >> 3],
2353		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2354
2355	proc_create("apm", 0, NULL, &apm_file_ops);
2356
2357	kapmd_task = kthread_create(apm, NULL, "kapmd");
2358	if (IS_ERR(kapmd_task)) {
2359		printk(KERN_ERR "apm: disabled - Unable to start kernel "
2360				"thread.\n");
2361		err = PTR_ERR(kapmd_task);
2362		kapmd_task = NULL;
2363		remove_proc_entry("apm", NULL);
2364		return err;
2365	}
2366	wake_up_process(kapmd_task);
2367
2368	if (num_online_cpus() > 1 && !smp) {
2369		printk(KERN_NOTICE
2370		       "apm: disabled - APM is not SMP safe (power off active).\n");
2371		return 0;
2372	}
2373
2374	/*
2375	 * Note we don't actually care if the misc_device cannot be registered.
2376	 * this driver can do its job without it, even if userspace can't
2377	 * control it.  just log the error
2378	 */
2379	if (misc_register(&apm_device))
2380		printk(KERN_WARNING "apm: Could not register misc device.\n");
2381
2382	if (HZ != 100)
2383		idle_period = (idle_period * HZ) / 100;
2384	if (idle_threshold < 100) {
2385		original_pm_idle = pm_idle;
2386		pm_idle  = apm_cpu_idle;
2387		set_pm_idle = 1;
2388	}
2389
2390	return 0;
2391}
2392
2393static void __exit apm_exit(void)
2394{
2395	int error;
2396
2397	if (set_pm_idle) {
2398		pm_idle = original_pm_idle;
2399		/*
2400		 * We are about to unload the current idle thread pm callback
2401		 * (pm_idle), Wait for all processors to update cached/local
2402		 * copies of pm_idle before proceeding.
2403		 */
2404		kick_all_cpus_sync();
2405	}
2406	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2407	    && (apm_info.connection_version > 0x0100)) {
2408		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2409		if (error)
2410			apm_error("disengage power management", error);
2411	}
2412	misc_deregister(&apm_device);
2413	remove_proc_entry("apm", NULL);
2414	if (power_off)
2415		pm_power_off = NULL;
2416	if (kapmd_task) {
2417		kthread_stop(kapmd_task);
2418		kapmd_task = NULL;
2419	}
2420}
2421
2422module_init(apm_init);
2423module_exit(apm_exit);
2424
2425MODULE_AUTHOR("Stephen Rothwell");
2426MODULE_DESCRIPTION("Advanced Power Management");
2427MODULE_LICENSE("GPL");
2428module_param(debug, bool, 0644);
2429MODULE_PARM_DESC(debug, "Enable debug mode");
2430module_param(power_off, bool, 0444);
2431MODULE_PARM_DESC(power_off, "Enable power off");
2432module_param(bounce_interval, int, 0444);
2433MODULE_PARM_DESC(bounce_interval,
2434		"Set the number of ticks to ignore suspend bounces");
2435module_param(allow_ints, bool, 0444);
2436MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2437module_param(broken_psr, bool, 0444);
2438MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2439module_param(realmode_power_off, bool, 0444);
2440MODULE_PARM_DESC(realmode_power_off,
2441		"Switch to real mode before powering off");
2442module_param(idle_threshold, int, 0444);
2443MODULE_PARM_DESC(idle_threshold,
2444	"System idle percentage above which to make APM BIOS idle calls");
2445module_param(idle_period, int, 0444);
2446MODULE_PARM_DESC(idle_period,
2447	"Period (in sec/100) over which to caculate the idle percentage");
2448module_param(smp, bool, 0444);
2449MODULE_PARM_DESC(smp,
2450	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2451MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);