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v4.17
 
   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/signal.h>
 222#include <linux/sched/cputime.h>
 223#include <linux/pm.h>
 224#include <linux/capability.h>
 225#include <linux/device.h>
 226#include <linux/kernel.h>
 227#include <linux/freezer.h>
 228#include <linux/smp.h>
 229#include <linux/dmi.h>
 230#include <linux/suspend.h>
 231#include <linux/kthread.h>
 232#include <linux/jiffies.h>
 233#include <linux/acpi.h>
 234#include <linux/syscore_ops.h>
 235#include <linux/i8253.h>
 236#include <linux/cpuidle.h>
 237
 238#include <linux/uaccess.h>
 239#include <asm/desc.h>
 240#include <asm/olpc.h>
 241#include <asm/paravirt.h>
 242#include <asm/reboot.h>
 
 
 243
 244#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 245extern int (*console_blank_hook)(int);
 246#endif
 247
 248/*
 249 * The apm_bios device is one of the misc char devices.
 250 * This is its minor number.
 251 */
 252#define	APM_MINOR_DEV	134
 253
 254/*
 255 * Various options can be changed at boot time as follows:
 256 * (We allow underscores for compatibility with the modules code)
 257 *	apm=on/off			enable/disable APM
 258 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 259 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 260 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 261 *	    					powering off
 262 *	    [no-]debug			log some debugging messages
 263 *	    [no-]power[-_]off		power off on shutdown
 264 *	    [no-]smp			Use apm even on an SMP box
 265 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 266 *	    				bounces
 267 *          idle[-_]threshold=<n>       System idle percentage above which to
 268 *                                      make APM BIOS idle calls. Set it to
 269 *                                      100 to disable.
 270 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 271 *                                      which the idle percentage is
 272 *                                      calculated.
 273 */
 274
 275/* KNOWN PROBLEM MACHINES:
 276 *
 277 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 278 *                         [Confirmed by TI representative]
 279 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 280 *                    [Confirmed by BIOS disassembly]
 281 *                    [This may work now ...]
 282 * P: Toshiba 1950S: battery life information only gets updated after resume
 283 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 284 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 285 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 286 * 	Neale Banks <neale@lowendale.com.au> December 2000
 287 *
 288 * Legend: U = unusable with APM patches
 289 *         P = partially usable with APM patches
 290 */
 291
 292/*
 293 * Define as 1 to make the driver always call the APM BIOS busy
 294 * routine even if the clock was not reported as slowed by the
 295 * idle routine.  Otherwise, define as 0.
 296 */
 297#define ALWAYS_CALL_BUSY   1
 298
 299/*
 300 * Define to make the APM BIOS calls zero all data segment registers (so
 301 * that an incorrect BIOS implementation will cause a kernel panic if it
 302 * tries to write to arbitrary memory).
 303 */
 304#define APM_ZERO_SEGS
 305
 306#include <asm/apm.h>
 307
 308/*
 309 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 310 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 311 * David Chen <chen@ctpa04.mit.edu>
 312 */
 313#undef INIT_TIMER_AFTER_SUSPEND
 314
 315#ifdef INIT_TIMER_AFTER_SUSPEND
 316#include <linux/timex.h>
 317#include <asm/io.h>
 318#include <linux/delay.h>
 319#endif
 320
 321/*
 322 * Need to poll the APM BIOS every second
 323 */
 324#define APM_CHECK_TIMEOUT	(HZ)
 325
 326/*
 327 * Ignore suspend events for this amount of time after a resume
 328 */
 329#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 330
 331/*
 332 * Maximum number of events stored
 333 */
 334#define APM_MAX_EVENTS		20
 335
 336/*
 337 * The per-file APM data
 338 */
 339struct apm_user {
 340	int		magic;
 341	struct apm_user *next;
 342	unsigned int	suser: 1;
 343	unsigned int	writer: 1;
 344	unsigned int	reader: 1;
 345	unsigned int	suspend_wait: 1;
 346	int		suspend_result;
 347	int		suspends_pending;
 348	int		standbys_pending;
 349	int		suspends_read;
 350	int		standbys_read;
 351	int		event_head;
 352	int		event_tail;
 353	apm_event_t	events[APM_MAX_EVENTS];
 354};
 355
 356/*
 357 * The magic number in apm_user
 358 */
 359#define APM_BIOS_MAGIC		0x4101
 360
 361/*
 362 * idle percentage above which bios idle calls are done
 363 */
 364#ifdef CONFIG_APM_CPU_IDLE
 365#define DEFAULT_IDLE_THRESHOLD	95
 366#else
 367#define DEFAULT_IDLE_THRESHOLD	100
 368#endif
 369#define DEFAULT_IDLE_PERIOD	(100 / 3)
 370
 371static int apm_cpu_idle(struct cpuidle_device *dev,
 372			struct cpuidle_driver *drv, int index);
 373
 374static struct cpuidle_driver apm_idle_driver = {
 375	.name = "apm_idle",
 376	.owner = THIS_MODULE,
 377	.states = {
 378		{ /* entry 0 is for polling */ },
 379		{ /* entry 1 is for APM idle */
 380			.name = "APM",
 381			.desc = "APM idle",
 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_rw(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_rw(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 err = 0;
 845
 846	if (!need_resched()) {
 847		idled = 1;
 848		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 849	}
 850
 851	if (!idled)
 852		return 0;
 853
 854	if (ret) {
 855		static unsigned long t;
 856
 857		/* This always fails on some SMP boards running UP kernels.
 858		 * Only report the failure the first 5 times.
 859		 */
 860		if (++t < 5) {
 861			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 862			t = jiffies;
 863		}
 864		return -1;
 865	}
 866	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 867	return clock_slowed;
 868}
 869
 870/**
 871 *	apm_do_busy	-	inform the BIOS the CPU is busy
 872 *
 873 *	Request that the BIOS brings the CPU back to full performance.
 874 */
 875
 876static void apm_do_busy(void)
 877{
 878	u32 dummy;
 879	int err;
 880
 881	if (clock_slowed || ALWAYS_CALL_BUSY) {
 882		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 883		clock_slowed = 0;
 884	}
 885}
 886
 887/*
 888 * If no process has really been interested in
 889 * the CPU for some time, we want to call BIOS
 890 * power management - we probably want
 891 * to conserve power.
 892 */
 893#define IDLE_CALC_LIMIT	(HZ * 100)
 894#define IDLE_LEAKY_MAX	16
 895
 896/**
 897 * apm_cpu_idle		-	cpu idling for APM capable Linux
 898 *
 899 * This is the idling function the kernel executes when APM is available. It
 900 * tries to do BIOS powermanagement based on the average system idle time.
 901 * Furthermore it calls the system default idle routine.
 902 */
 903
 904static int apm_cpu_idle(struct cpuidle_device *dev,
 905	struct cpuidle_driver *drv, int index)
 906{
 907	static int use_apm_idle; /* = 0 */
 908	static unsigned int last_jiffies; /* = 0 */
 909	static u64 last_stime; /* = 0 */
 910	u64 stime, utime;
 911
 912	int apm_idle_done = 0;
 913	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 914	unsigned int bucket;
 915
 916recalc:
 917	task_cputime(current, &utime, &stime);
 918	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 919		use_apm_idle = 0;
 920	} else if (jiffies_since_last_check > idle_period) {
 921		unsigned int idle_percentage;
 922
 923		idle_percentage = nsecs_to_jiffies(stime - last_stime);
 924		idle_percentage *= 100;
 925		idle_percentage /= jiffies_since_last_check;
 926		use_apm_idle = (idle_percentage > idle_threshold);
 927		if (apm_info.forbid_idle)
 928			use_apm_idle = 0;
 929	}
 930
 931	last_jiffies = jiffies;
 932	last_stime = stime;
 933
 934	bucket = IDLE_LEAKY_MAX;
 935
 936	while (!need_resched()) {
 937		if (use_apm_idle) {
 938			unsigned int t;
 939
 940			t = jiffies;
 941			switch (apm_do_idle()) {
 942			case 0:
 943				apm_idle_done = 1;
 944				if (t != jiffies) {
 945					if (bucket) {
 946						bucket = IDLE_LEAKY_MAX;
 947						continue;
 948					}
 949				} else if (bucket) {
 950					bucket--;
 951					continue;
 952				}
 953				break;
 954			case 1:
 955				apm_idle_done = 1;
 956				break;
 957			default: /* BIOS refused */
 958				break;
 959			}
 960		}
 961		default_idle();
 962		local_irq_disable();
 963		jiffies_since_last_check = jiffies - last_jiffies;
 964		if (jiffies_since_last_check > idle_period)
 965			goto recalc;
 966	}
 967
 968	if (apm_idle_done)
 969		apm_do_busy();
 970
 971	return index;
 972}
 973
 974/**
 975 *	apm_power_off	-	ask the BIOS to power off
 976 *
 977 *	Handle the power off sequence. This is the one piece of code we
 978 *	will execute even on SMP machines. In order to deal with BIOS
 979 *	bugs we support real mode APM BIOS power off calls. We also make
 980 *	the SMP call on CPU0 as some systems will only honour this call
 981 *	on their first cpu.
 982 */
 983
 984static void apm_power_off(void)
 985{
 986	/* Some bioses don't like being called from CPU != 0 */
 987	if (apm_info.realmode_power_off) {
 988		set_cpus_allowed_ptr(current, cpumask_of(0));
 989		machine_real_restart(MRR_APM);
 990	} else {
 991		(void)set_system_power_state(APM_STATE_OFF);
 992	}
 993}
 994
 995#ifdef CONFIG_APM_DO_ENABLE
 996
 997/**
 998 *	apm_enable_power_management - enable BIOS APM power management
 999 *	@enable: enable yes/no
1000 *
1001 *	Enable or disable the APM BIOS power services.
1002 */
1003
1004static int apm_enable_power_management(int enable)
1005{
1006	u32 eax;
1007	int err;
1008
1009	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1010		return APM_NOT_ENGAGED;
1011	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1012				 enable, &eax, &err))
1013		return err;
1014	if (enable)
1015		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1016	else
1017		apm_info.bios.flags |= APM_BIOS_DISABLED;
1018	return APM_SUCCESS;
1019}
1020#endif
1021
1022/**
1023 *	apm_get_power_status	-	get current power state
1024 *	@status: returned status
1025 *	@bat: battery info
1026 *	@life: estimated life
1027 *
1028 *	Obtain the current power status from the APM BIOS. We return a
1029 *	status which gives the rough battery status, and current power
1030 *	source. The bat value returned give an estimate as a percentage
1031 *	of life and a status value for the battery. The estimated life
1032 *	if reported is a lifetime in secodnds/minutes at current powwer
1033 *	consumption.
1034 */
1035
1036static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1037{
1038	struct apm_bios_call call;
1039
1040	call.func = APM_FUNC_GET_STATUS;
1041	call.ebx = APM_DEVICE_ALL;
1042	call.ecx = 0;
1043
1044	if (apm_info.get_power_status_broken)
1045		return APM_32_UNSUPPORTED;
1046	if (apm_bios_call(&call)) {
1047		if (!call.err)
1048			return APM_NO_ERROR;
1049		return call.err;
1050	}
1051	*status = call.ebx;
1052	*bat = call.ecx;
1053	if (apm_info.get_power_status_swabinminutes) {
1054		*life = swab16((u16)call.edx);
1055		*life |= 0x8000;
1056	} else
1057		*life = call.edx;
1058	return APM_SUCCESS;
1059}
1060
1061#if 0
1062static int apm_get_battery_status(u_short which, u_short *status,
1063				  u_short *bat, u_short *life, u_short *nbat)
1064{
1065	u32 eax;
1066	u32 ebx;
1067	u32 ecx;
1068	u32 edx;
1069	u32 esi;
1070
1071	if (apm_info.connection_version < 0x0102) {
1072		/* pretend we only have one battery. */
1073		if (which != 1)
1074			return APM_BAD_DEVICE;
1075		*nbat = 1;
1076		return apm_get_power_status(status, bat, life);
1077	}
1078
1079	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1080			  &ebx, &ecx, &edx, &esi))
1081		return (eax >> 8) & 0xff;
1082	*status = ebx;
1083	*bat = ecx;
1084	*life = edx;
1085	*nbat = esi;
1086	return APM_SUCCESS;
1087}
1088#endif
1089
1090/**
1091 *	apm_engage_power_management	-	enable PM on a device
1092 *	@device: identity of device
1093 *	@enable: on/off
1094 *
1095 *	Activate or deactivate power management on either a specific device
1096 *	or the entire system (%APM_DEVICE_ALL).
1097 */
1098
1099static int apm_engage_power_management(u_short device, int enable)
1100{
1101	u32 eax;
1102	int err;
1103
1104	if ((enable == 0) && (device == APM_DEVICE_ALL)
1105	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1106		return APM_DISABLED;
1107	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1108				 &eax, &err))
1109		return err;
1110	if (device == APM_DEVICE_ALL) {
1111		if (enable)
1112			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1113		else
1114			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1115	}
1116	return APM_SUCCESS;
1117}
1118
1119#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1120
1121/**
1122 *	apm_console_blank	-	blank the display
1123 *	@blank: on/off
1124 *
1125 *	Attempt to blank the console, firstly by blanking just video device
1126 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1127 *	all video devices. Typically the BIOS will do laptop backlight and
1128 *	monitor powerdown for us.
1129 */
1130
1131static int apm_console_blank(int blank)
1132{
1133	int error = APM_NOT_ENGAGED; /* silence gcc */
1134	int i;
1135	u_short state;
1136	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1137
1138	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1139
1140	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1141		error = set_power_state(dev[i], state);
1142
1143		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1144			return 1;
1145
1146		if (error == APM_NOT_ENGAGED)
1147			break;
1148	}
1149
1150	if (error == APM_NOT_ENGAGED) {
1151		static int tried;
1152		int eng_error;
1153		if (tried++ == 0) {
1154			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1155			if (eng_error) {
1156				apm_error("set display", error);
1157				apm_error("engage interface", eng_error);
1158				return 0;
1159			} else
1160				return apm_console_blank(blank);
1161		}
1162	}
1163	apm_error("set display", error);
1164	return 0;
1165}
1166#endif
1167
1168static int queue_empty(struct apm_user *as)
1169{
1170	return as->event_head == as->event_tail;
1171}
1172
1173static apm_event_t get_queued_event(struct apm_user *as)
1174{
1175	if (++as->event_tail >= APM_MAX_EVENTS)
1176		as->event_tail = 0;
1177	return as->events[as->event_tail];
1178}
1179
1180static void queue_event(apm_event_t event, struct apm_user *sender)
1181{
1182	struct apm_user *as;
1183
1184	spin_lock(&user_list_lock);
1185	if (user_list == NULL)
1186		goto out;
1187	for (as = user_list; as != NULL; as = as->next) {
1188		if ((as == sender) || (!as->reader))
1189			continue;
1190		if (++as->event_head >= APM_MAX_EVENTS)
1191			as->event_head = 0;
1192
1193		if (as->event_head == as->event_tail) {
1194			static int notified;
1195
1196			if (notified++ == 0)
1197				pr_err("an event queue overflowed\n");
1198			if (++as->event_tail >= APM_MAX_EVENTS)
1199				as->event_tail = 0;
1200		}
1201		as->events[as->event_head] = event;
1202		if (!as->suser || !as->writer)
1203			continue;
1204		switch (event) {
1205		case APM_SYS_SUSPEND:
1206		case APM_USER_SUSPEND:
1207			as->suspends_pending++;
1208			suspends_pending++;
1209			break;
1210
1211		case APM_SYS_STANDBY:
1212		case APM_USER_STANDBY:
1213			as->standbys_pending++;
1214			standbys_pending++;
1215			break;
1216		}
1217	}
1218	wake_up_interruptible(&apm_waitqueue);
1219out:
1220	spin_unlock(&user_list_lock);
1221}
1222
1223static void reinit_timer(void)
1224{
1225#ifdef INIT_TIMER_AFTER_SUSPEND
1226	unsigned long flags;
1227
1228	raw_spin_lock_irqsave(&i8253_lock, flags);
1229	/* set the clock to HZ */
1230	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1231	udelay(10);
1232	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1233	udelay(10);
1234	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1235	udelay(10);
1236	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1237#endif
1238}
1239
1240static int suspend(int vetoable)
1241{
1242	int err;
1243	struct apm_user	*as;
1244
1245	dpm_suspend_start(PMSG_SUSPEND);
1246	dpm_suspend_end(PMSG_SUSPEND);
1247
1248	local_irq_disable();
1249	syscore_suspend();
1250
1251	local_irq_enable();
1252
1253	save_processor_state();
1254	err = set_system_power_state(APM_STATE_SUSPEND);
1255	ignore_normal_resume = 1;
1256	restore_processor_state();
1257
1258	local_irq_disable();
1259	reinit_timer();
1260
1261	if (err == APM_NO_ERROR)
1262		err = APM_SUCCESS;
1263	if (err != APM_SUCCESS)
1264		apm_error("suspend", err);
1265	err = (err == APM_SUCCESS) ? 0 : -EIO;
1266
1267	syscore_resume();
1268	local_irq_enable();
1269
1270	dpm_resume_start(PMSG_RESUME);
1271	dpm_resume_end(PMSG_RESUME);
1272
1273	queue_event(APM_NORMAL_RESUME, NULL);
1274	spin_lock(&user_list_lock);
1275	for (as = user_list; as != NULL; as = as->next) {
1276		as->suspend_wait = 0;
1277		as->suspend_result = err;
1278	}
1279	spin_unlock(&user_list_lock);
1280	wake_up_interruptible(&apm_suspend_waitqueue);
1281	return err;
1282}
1283
1284static void standby(void)
1285{
1286	int err;
1287
1288	dpm_suspend_end(PMSG_SUSPEND);
1289
1290	local_irq_disable();
1291	syscore_suspend();
1292	local_irq_enable();
1293
1294	err = set_system_power_state(APM_STATE_STANDBY);
1295	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1296		apm_error("standby", err);
1297
1298	local_irq_disable();
1299	syscore_resume();
1300	local_irq_enable();
1301
1302	dpm_resume_start(PMSG_RESUME);
1303}
1304
1305static apm_event_t get_event(void)
1306{
1307	int error;
1308	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1309	apm_eventinfo_t	info;
1310
1311	static int notified;
1312
1313	/* we don't use the eventinfo */
1314	error = apm_get_event(&event, &info);
1315	if (error == APM_SUCCESS)
1316		return event;
1317
1318	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1319		apm_error("get_event", error);
1320
1321	return 0;
1322}
1323
1324static void check_events(void)
1325{
1326	apm_event_t event;
1327	static unsigned long last_resume;
1328	static int ignore_bounce;
1329
1330	while ((event = get_event()) != 0) {
1331		if (debug) {
1332			if (event <= NR_APM_EVENT_NAME)
1333				printk(KERN_DEBUG "apm: received %s notify\n",
1334				       apm_event_name[event - 1]);
1335			else
1336				printk(KERN_DEBUG "apm: received unknown "
1337				       "event 0x%02x\n", event);
1338		}
1339		if (ignore_bounce
1340		    && (time_after(jiffies, last_resume + bounce_interval)))
1341			ignore_bounce = 0;
1342
1343		switch (event) {
1344		case APM_SYS_STANDBY:
1345		case APM_USER_STANDBY:
1346			queue_event(event, NULL);
1347			if (standbys_pending <= 0)
1348				standby();
1349			break;
1350
1351		case APM_USER_SUSPEND:
1352#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1353			if (apm_info.connection_version > 0x100)
1354				set_system_power_state(APM_STATE_REJECT);
1355			break;
1356#endif
1357		case APM_SYS_SUSPEND:
1358			if (ignore_bounce) {
1359				if (apm_info.connection_version > 0x100)
1360					set_system_power_state(APM_STATE_REJECT);
1361				break;
1362			}
1363			/*
1364			 * If we are already processing a SUSPEND,
1365			 * then further SUSPEND events from the BIOS
1366			 * will be ignored.  We also return here to
1367			 * cope with the fact that the Thinkpads keep
1368			 * sending a SUSPEND event until something else
1369			 * happens!
1370			 */
1371			if (ignore_sys_suspend)
1372				return;
1373			ignore_sys_suspend = 1;
1374			queue_event(event, NULL);
1375			if (suspends_pending <= 0)
1376				(void) suspend(1);
1377			break;
1378
1379		case APM_NORMAL_RESUME:
1380		case APM_CRITICAL_RESUME:
1381		case APM_STANDBY_RESUME:
1382			ignore_sys_suspend = 0;
1383			last_resume = jiffies;
1384			ignore_bounce = 1;
1385			if ((event != APM_NORMAL_RESUME)
1386			    || (ignore_normal_resume == 0)) {
1387				dpm_resume_end(PMSG_RESUME);
1388				queue_event(event, NULL);
1389			}
1390			ignore_normal_resume = 0;
1391			break;
1392
1393		case APM_CAPABILITY_CHANGE:
1394		case APM_LOW_BATTERY:
1395		case APM_POWER_STATUS_CHANGE:
1396			queue_event(event, NULL);
1397			/* If needed, notify drivers here */
1398			break;
1399
1400		case APM_UPDATE_TIME:
1401			break;
1402
1403		case APM_CRITICAL_SUSPEND:
1404			/*
1405			 * We are not allowed to reject a critical suspend.
1406			 */
1407			(void)suspend(0);
1408			break;
1409		}
1410	}
1411}
1412
1413static void apm_event_handler(void)
1414{
1415	static int pending_count = 4;
1416	int err;
1417
1418	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1419		if ((apm_info.connection_version > 0x100) &&
1420		    (pending_count-- <= 0)) {
1421			pending_count = 4;
1422			if (debug)
1423				printk(KERN_DEBUG "apm: setting state busy\n");
1424			err = set_system_power_state(APM_STATE_BUSY);
1425			if (err)
1426				apm_error("busy", err);
1427		}
1428	} else
1429		pending_count = 4;
1430	check_events();
1431}
1432
1433/*
1434 * This is the APM thread main loop.
1435 */
1436
1437static void apm_mainloop(void)
1438{
1439	DECLARE_WAITQUEUE(wait, current);
1440
1441	add_wait_queue(&apm_waitqueue, &wait);
1442	set_current_state(TASK_INTERRUPTIBLE);
1443	for (;;) {
1444		schedule_timeout(APM_CHECK_TIMEOUT);
1445		if (kthread_should_stop())
1446			break;
1447		/*
1448		 * Ok, check all events, check for idle (and mark us sleeping
1449		 * so as not to count towards the load average)..
1450		 */
1451		set_current_state(TASK_INTERRUPTIBLE);
1452		apm_event_handler();
1453	}
1454	remove_wait_queue(&apm_waitqueue, &wait);
1455}
1456
1457static int check_apm_user(struct apm_user *as, const char *func)
1458{
1459	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1460		pr_err("%s passed bad filp\n", func);
1461		return 1;
1462	}
1463	return 0;
1464}
1465
1466static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1467{
1468	struct apm_user *as;
1469	int i;
1470	apm_event_t event;
1471
1472	as = fp->private_data;
1473	if (check_apm_user(as, "read"))
1474		return -EIO;
1475	if ((int)count < sizeof(apm_event_t))
1476		return -EINVAL;
1477	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1478		return -EAGAIN;
1479	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1480	i = count;
1481	while ((i >= sizeof(event)) && !queue_empty(as)) {
1482		event = get_queued_event(as);
1483		if (copy_to_user(buf, &event, sizeof(event))) {
1484			if (i < count)
1485				break;
1486			return -EFAULT;
1487		}
1488		switch (event) {
1489		case APM_SYS_SUSPEND:
1490		case APM_USER_SUSPEND:
1491			as->suspends_read++;
1492			break;
1493
1494		case APM_SYS_STANDBY:
1495		case APM_USER_STANDBY:
1496			as->standbys_read++;
1497			break;
1498		}
1499		buf += sizeof(event);
1500		i -= sizeof(event);
1501	}
1502	if (i < count)
1503		return count - i;
1504	if (signal_pending(current))
1505		return -ERESTARTSYS;
1506	return 0;
1507}
1508
1509static __poll_t do_poll(struct file *fp, poll_table *wait)
1510{
1511	struct apm_user *as;
1512
1513	as = fp->private_data;
1514	if (check_apm_user(as, "poll"))
1515		return 0;
1516	poll_wait(fp, &apm_waitqueue, wait);
1517	if (!queue_empty(as))
1518		return EPOLLIN | EPOLLRDNORM;
1519	return 0;
1520}
1521
1522static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1523{
1524	struct apm_user *as;
1525	int ret;
1526
1527	as = filp->private_data;
1528	if (check_apm_user(as, "ioctl"))
1529		return -EIO;
1530	if (!as->suser || !as->writer)
1531		return -EPERM;
1532	switch (cmd) {
1533	case APM_IOC_STANDBY:
1534		mutex_lock(&apm_mutex);
1535		if (as->standbys_read > 0) {
1536			as->standbys_read--;
1537			as->standbys_pending--;
1538			standbys_pending--;
1539		} else
1540			queue_event(APM_USER_STANDBY, as);
1541		if (standbys_pending <= 0)
1542			standby();
1543		mutex_unlock(&apm_mutex);
1544		break;
1545	case APM_IOC_SUSPEND:
1546		mutex_lock(&apm_mutex);
1547		if (as->suspends_read > 0) {
1548			as->suspends_read--;
1549			as->suspends_pending--;
1550			suspends_pending--;
1551		} else
1552			queue_event(APM_USER_SUSPEND, as);
1553		if (suspends_pending <= 0) {
1554			ret = suspend(1);
1555			mutex_unlock(&apm_mutex);
1556		} else {
1557			as->suspend_wait = 1;
1558			mutex_unlock(&apm_mutex);
1559			wait_event_interruptible(apm_suspend_waitqueue,
1560					as->suspend_wait == 0);
1561			ret = as->suspend_result;
1562		}
1563		return ret;
1564	default:
1565		return -ENOTTY;
1566	}
1567	return 0;
1568}
1569
1570static int do_release(struct inode *inode, struct file *filp)
1571{
1572	struct apm_user *as;
1573
1574	as = filp->private_data;
1575	if (check_apm_user(as, "release"))
1576		return 0;
1577	filp->private_data = NULL;
1578	if (as->standbys_pending > 0) {
1579		standbys_pending -= as->standbys_pending;
1580		if (standbys_pending <= 0)
1581			standby();
1582	}
1583	if (as->suspends_pending > 0) {
1584		suspends_pending -= as->suspends_pending;
1585		if (suspends_pending <= 0)
1586			(void) suspend(1);
1587	}
1588	spin_lock(&user_list_lock);
1589	if (user_list == as)
1590		user_list = as->next;
1591	else {
1592		struct apm_user *as1;
1593
1594		for (as1 = user_list;
1595		     (as1 != NULL) && (as1->next != as);
1596		     as1 = as1->next)
1597			;
1598		if (as1 == NULL)
1599			pr_err("filp not in user list\n");
1600		else
1601			as1->next = as->next;
1602	}
1603	spin_unlock(&user_list_lock);
1604	kfree(as);
1605	return 0;
1606}
1607
1608static int do_open(struct inode *inode, struct file *filp)
1609{
1610	struct apm_user *as;
1611
1612	as = kmalloc(sizeof(*as), GFP_KERNEL);
1613	if (as == NULL)
1614		return -ENOMEM;
1615
1616	as->magic = APM_BIOS_MAGIC;
1617	as->event_tail = as->event_head = 0;
1618	as->suspends_pending = as->standbys_pending = 0;
1619	as->suspends_read = as->standbys_read = 0;
1620	/*
1621	 * XXX - this is a tiny bit broken, when we consider BSD
1622	 * process accounting. If the device is opened by root, we
1623	 * instantly flag that we used superuser privs. Who knows,
1624	 * we might close the device immediately without doing a
1625	 * privileged operation -- cevans
1626	 */
1627	as->suser = capable(CAP_SYS_ADMIN);
1628	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1629	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1630	spin_lock(&user_list_lock);
1631	as->next = user_list;
1632	user_list = as;
1633	spin_unlock(&user_list_lock);
1634	filp->private_data = as;
1635	return 0;
1636}
1637
 
1638static int proc_apm_show(struct seq_file *m, void *v)
1639{
1640	unsigned short	bx;
1641	unsigned short	cx;
1642	unsigned short	dx;
1643	int		error;
1644	unsigned short  ac_line_status = 0xff;
1645	unsigned short  battery_status = 0xff;
1646	unsigned short  battery_flag   = 0xff;
1647	int		percentage     = -1;
1648	int             time_units     = -1;
1649	char            *units         = "?";
1650
1651	if ((num_online_cpus() == 1) &&
1652	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1653		ac_line_status = (bx >> 8) & 0xff;
1654		battery_status = bx & 0xff;
1655		if ((cx & 0xff) != 0xff)
1656			percentage = cx & 0xff;
1657
1658		if (apm_info.connection_version > 0x100) {
1659			battery_flag = (cx >> 8) & 0xff;
1660			if (dx != 0xffff) {
1661				units = (dx & 0x8000) ? "min" : "sec";
1662				time_units = dx & 0x7fff;
1663			}
1664		}
1665	}
1666	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1667	   from the Get Power Status (0x0a) call unless otherwise noted.
1668
1669	   0) Linux driver version (this will change if format changes)
1670	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1671	   2) APM flags from APM Installation Check (0x00):
1672	      bit 0: APM_16_BIT_SUPPORT
1673	      bit 1: APM_32_BIT_SUPPORT
1674	      bit 2: APM_IDLE_SLOWS_CLOCK
1675	      bit 3: APM_BIOS_DISABLED
1676	      bit 4: APM_BIOS_DISENGAGED
1677	   3) AC line status
1678	      0x00: Off-line
1679	      0x01: On-line
1680	      0x02: On backup power (BIOS >= 1.1 only)
1681	      0xff: Unknown
1682	   4) Battery status
1683	      0x00: High
1684	      0x01: Low
1685	      0x02: Critical
1686	      0x03: Charging
1687	      0x04: Selected battery not present (BIOS >= 1.2 only)
1688	      0xff: Unknown
1689	   5) Battery flag
1690	      bit 0: High
1691	      bit 1: Low
1692	      bit 2: Critical
1693	      bit 3: Charging
1694	      bit 7: No system battery
1695	      0xff: Unknown
1696	   6) Remaining battery life (percentage of charge):
1697	      0-100: valid
1698	      -1: Unknown
1699	   7) Remaining battery life (time units):
1700	      Number of remaining minutes or seconds
1701	      -1: Unknown
1702	   8) min = minutes; sec = seconds */
1703
1704	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1705		   driver_version,
1706		   (apm_info.bios.version >> 8) & 0xff,
1707		   apm_info.bios.version & 0xff,
1708		   apm_info.bios.flags,
1709		   ac_line_status,
1710		   battery_status,
1711		   battery_flag,
1712		   percentage,
1713		   time_units,
1714		   units);
1715	return 0;
1716}
1717
1718static int proc_apm_open(struct inode *inode, struct file *file)
1719{
1720	return single_open(file, proc_apm_show, NULL);
1721}
1722
1723static const struct file_operations apm_file_ops = {
1724	.owner		= THIS_MODULE,
1725	.open		= proc_apm_open,
1726	.read		= seq_read,
1727	.llseek		= seq_lseek,
1728	.release	= single_release,
1729};
1730
1731static int apm(void *unused)
1732{
1733	unsigned short	bx;
1734	unsigned short	cx;
1735	unsigned short	dx;
1736	int		error;
1737	char 		*power_stat;
1738	char 		*bat_stat;
1739
1740	/* 2002/08/01 - WT
1741	 * This is to avoid random crashes at boot time during initialization
1742	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1743	 * Some bioses don't like being called from CPU != 0.
1744	 * Method suggested by Ingo Molnar.
1745	 */
1746	set_cpus_allowed_ptr(current, cpumask_of(0));
1747	BUG_ON(smp_processor_id() != 0);
1748
1749	if (apm_info.connection_version == 0) {
1750		apm_info.connection_version = apm_info.bios.version;
1751		if (apm_info.connection_version > 0x100) {
1752			/*
1753			 * We only support BIOSs up to version 1.2
1754			 */
1755			if (apm_info.connection_version > 0x0102)
1756				apm_info.connection_version = 0x0102;
1757			error = apm_driver_version(&apm_info.connection_version);
1758			if (error != APM_SUCCESS) {
1759				apm_error("driver version", error);
1760				/* Fall back to an APM 1.0 connection. */
1761				apm_info.connection_version = 0x100;
1762			}
1763		}
1764	}
1765
1766	if (debug)
1767		printk(KERN_INFO "apm: Connection version %d.%d\n",
1768			(apm_info.connection_version >> 8) & 0xff,
1769			apm_info.connection_version & 0xff);
1770
1771#ifdef CONFIG_APM_DO_ENABLE
1772	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1773		/*
1774		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1775		 * is booted with PM disabled but not in the docking station.
1776		 * Unfortunate ...
1777		 */
1778		error = apm_enable_power_management(1);
1779		if (error) {
1780			apm_error("enable power management", error);
1781			return -1;
1782		}
1783	}
1784#endif
1785
1786	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1787	    && (apm_info.connection_version > 0x0100)) {
1788		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1789		if (error) {
1790			apm_error("engage power management", error);
1791			return -1;
1792		}
1793	}
1794
1795	if (debug && (num_online_cpus() == 1 || smp)) {
1796		error = apm_get_power_status(&bx, &cx, &dx);
1797		if (error)
1798			printk(KERN_INFO "apm: power status not available\n");
1799		else {
1800			switch ((bx >> 8) & 0xff) {
1801			case 0:
1802				power_stat = "off line";
1803				break;
1804			case 1:
1805				power_stat = "on line";
1806				break;
1807			case 2:
1808				power_stat = "on backup power";
1809				break;
1810			default:
1811				power_stat = "unknown";
1812				break;
1813			}
1814			switch (bx & 0xff) {
1815			case 0:
1816				bat_stat = "high";
1817				break;
1818			case 1:
1819				bat_stat = "low";
1820				break;
1821			case 2:
1822				bat_stat = "critical";
1823				break;
1824			case 3:
1825				bat_stat = "charging";
1826				break;
1827			default:
1828				bat_stat = "unknown";
1829				break;
1830			}
1831			printk(KERN_INFO
1832			       "apm: AC %s, battery status %s, battery life ",
1833			       power_stat, bat_stat);
1834			if ((cx & 0xff) == 0xff)
1835				printk("unknown\n");
1836			else
1837				printk("%d%%\n", cx & 0xff);
1838			if (apm_info.connection_version > 0x100) {
1839				printk(KERN_INFO
1840				       "apm: battery flag 0x%02x, battery life ",
1841				       (cx >> 8) & 0xff);
1842				if (dx == 0xffff)
1843					printk("unknown\n");
1844				else
1845					printk("%d %s\n", dx & 0x7fff,
1846					       (dx & 0x8000) ?
1847					       "minutes" : "seconds");
1848			}
1849		}
1850	}
1851
1852	/* Install our power off handler.. */
1853	if (power_off)
1854		pm_power_off = apm_power_off;
1855
1856	if (num_online_cpus() == 1 || smp) {
1857#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1858		console_blank_hook = apm_console_blank;
1859#endif
1860		apm_mainloop();
1861#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1862		console_blank_hook = NULL;
1863#endif
1864	}
1865
1866	return 0;
1867}
1868
1869#ifndef MODULE
1870static int __init apm_setup(char *str)
1871{
1872	int invert;
1873
1874	while ((str != NULL) && (*str != '\0')) {
1875		if (strncmp(str, "off", 3) == 0)
1876			apm_disabled = 1;
1877		if (strncmp(str, "on", 2) == 0)
1878			apm_disabled = 0;
1879		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1880		    (strncmp(str, "bounce_interval=", 16) == 0))
1881			bounce_interval = simple_strtol(str + 16, NULL, 0);
1882		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1883		    (strncmp(str, "idle_threshold=", 15) == 0))
1884			idle_threshold = simple_strtol(str + 15, NULL, 0);
1885		if ((strncmp(str, "idle-period=", 12) == 0) ||
1886		    (strncmp(str, "idle_period=", 12) == 0))
1887			idle_period = simple_strtol(str + 12, NULL, 0);
1888		invert = (strncmp(str, "no-", 3) == 0) ||
1889			(strncmp(str, "no_", 3) == 0);
1890		if (invert)
1891			str += 3;
1892		if (strncmp(str, "debug", 5) == 0)
1893			debug = !invert;
1894		if ((strncmp(str, "power-off", 9) == 0) ||
1895		    (strncmp(str, "power_off", 9) == 0))
1896			power_off = !invert;
1897		if (strncmp(str, "smp", 3) == 0) {
1898			smp = !invert;
1899			idle_threshold = 100;
1900		}
1901		if ((strncmp(str, "allow-ints", 10) == 0) ||
1902		    (strncmp(str, "allow_ints", 10) == 0))
1903			apm_info.allow_ints = !invert;
1904		if ((strncmp(str, "broken-psr", 10) == 0) ||
1905		    (strncmp(str, "broken_psr", 10) == 0))
1906			apm_info.get_power_status_broken = !invert;
1907		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1908		    (strncmp(str, "realmode_power_off", 18) == 0))
1909			apm_info.realmode_power_off = !invert;
1910		str = strchr(str, ',');
1911		if (str != NULL)
1912			str += strspn(str, ", \t");
1913	}
1914	return 1;
1915}
1916
1917__setup("apm=", apm_setup);
1918#endif
1919
1920static const struct file_operations apm_bios_fops = {
1921	.owner		= THIS_MODULE,
1922	.read		= do_read,
1923	.poll		= do_poll,
1924	.unlocked_ioctl	= do_ioctl,
1925	.open		= do_open,
1926	.release	= do_release,
1927	.llseek		= noop_llseek,
1928};
1929
1930static struct miscdevice apm_device = {
1931	APM_MINOR_DEV,
1932	"apm_bios",
1933	&apm_bios_fops
1934};
1935
1936
1937/* Simple "print if true" callback */
1938static int __init print_if_true(const struct dmi_system_id *d)
1939{
1940	printk("%s\n", d->ident);
1941	return 0;
1942}
1943
1944/*
1945 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1946 * disabled before the suspend. Linux used to get terribly confused by that.
1947 */
1948static int __init broken_ps2_resume(const struct dmi_system_id *d)
1949{
1950	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1951	       "workaround hopefully not needed.\n", d->ident);
1952	return 0;
1953}
1954
1955/* Some bioses have a broken protected mode poweroff and need to use realmode */
1956static int __init set_realmode_power_off(const struct dmi_system_id *d)
1957{
1958	if (apm_info.realmode_power_off == 0) {
1959		apm_info.realmode_power_off = 1;
1960		printk(KERN_INFO "%s bios detected. "
1961		       "Using realmode poweroff only.\n", d->ident);
1962	}
1963	return 0;
1964}
1965
1966/* Some laptops require interrupts to be enabled during APM calls */
1967static int __init set_apm_ints(const struct dmi_system_id *d)
1968{
1969	if (apm_info.allow_ints == 0) {
1970		apm_info.allow_ints = 1;
1971		printk(KERN_INFO "%s machine detected. "
1972		       "Enabling interrupts during APM calls.\n", d->ident);
1973	}
1974	return 0;
1975}
1976
1977/* Some APM bioses corrupt memory or just plain do not work */
1978static int __init apm_is_horked(const struct dmi_system_id *d)
1979{
1980	if (apm_info.disabled == 0) {
1981		apm_info.disabled = 1;
1982		printk(KERN_INFO "%s machine detected. "
1983		       "Disabling APM.\n", d->ident);
1984	}
1985	return 0;
1986}
1987
1988static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1989{
1990	if (apm_info.disabled == 0) {
1991		apm_info.disabled = 1;
1992		printk(KERN_INFO "%s machine detected. "
1993		       "Disabling APM.\n", d->ident);
1994		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1995		printk(KERN_INFO "download from support.intel.com\n");
1996	}
1997	return 0;
1998}
1999
2000/* Some APM bioses hang on APM idle calls */
2001static int __init apm_likes_to_melt(const struct dmi_system_id *d)
2002{
2003	if (apm_info.forbid_idle == 0) {
2004		apm_info.forbid_idle = 1;
2005		printk(KERN_INFO "%s machine detected. "
2006		       "Disabling APM idle calls.\n", d->ident);
2007	}
2008	return 0;
2009}
2010
2011/*
2012 *  Check for clue free BIOS implementations who use
2013 *  the following QA technique
2014 *
2015 *      [ Write BIOS Code ]<------
2016 *               |                ^
2017 *      < Does it Compile >----N--
2018 *               |Y               ^
2019 *	< Does it Boot Win98 >-N--
2020 *               |Y
2021 *           [Ship It]
2022 *
2023 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2024 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2025 */
2026static int __init broken_apm_power(const struct dmi_system_id *d)
2027{
2028	apm_info.get_power_status_broken = 1;
2029	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2030	       "disabling power status reporting.\n");
2031	return 0;
2032}
2033
2034/*
2035 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2036 * have this problem).
2037 */
2038static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2039{
2040	apm_info.get_power_status_swabinminutes = 1;
2041	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2042	       "in minutes and wrong byte order.\n");
2043	return 0;
2044}
2045
2046static const struct dmi_system_id apm_dmi_table[] __initconst = {
2047	{
2048		print_if_true,
2049		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2050		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2051			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2052	},
2053	{	/* Handle problems with APM on the C600 */
2054		broken_ps2_resume, "Dell Latitude C600",
2055		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2056			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2057	},
2058	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2059		set_apm_ints, "Dell Latitude",
2060		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2061			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2062	},
2063	{	/* APM crashes */
2064		apm_is_horked, "Dell Inspiron 2500",
2065		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2066			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2067			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2068			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2069	},
2070	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2071		set_apm_ints, "Dell Inspiron", {
2072			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2073			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2074	},
2075	{	/* Handle problems with APM on Inspiron 5000e */
2076		broken_apm_power, "Dell Inspiron 5000e",
2077		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2078			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2079			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2080	},
2081	{	/* Handle problems with APM on Inspiron 2500 */
2082		broken_apm_power, "Dell Inspiron 2500",
2083		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2084			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2085			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2086	},
2087	{	/* APM crashes */
2088		apm_is_horked, "Dell Dimension 4100",
2089		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2090			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2091			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2092			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2093	},
2094	{	/* Allow interrupts during suspend on Compaq Laptops*/
2095		set_apm_ints, "Compaq 12XL125",
2096		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2097			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2098			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2099			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2100	},
2101	{	/* Allow interrupts during APM or the clock goes slow */
2102		set_apm_ints, "ASUSTeK",
2103		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2104			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2105	},
2106	{	/* APM blows on shutdown */
2107		apm_is_horked, "ABIT KX7-333[R]",
2108		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2109			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2110	},
2111	{	/* APM crashes */
2112		apm_is_horked, "Trigem Delhi3",
2113		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2114			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2115	},
2116	{	/* APM crashes */
2117		apm_is_horked, "Fujitsu-Siemens",
2118		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2119			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2120	},
2121	{	/* APM crashes */
2122		apm_is_horked_d850md, "Intel D850MD",
2123		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2124			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2125	},
2126	{	/* APM crashes */
2127		apm_is_horked, "Intel D810EMO",
2128		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2129			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2130	},
2131	{	/* APM crashes */
2132		apm_is_horked, "Dell XPS-Z",
2133		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2134			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2135			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2136	},
2137	{	/* APM crashes */
2138		apm_is_horked, "Sharp PC-PJ/AX",
2139		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2140			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2141			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2142			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2143	},
2144	{	/* APM crashes */
2145		apm_is_horked, "Dell Inspiron 2500",
2146		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2147			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2148			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2149			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2150	},
2151	{	/* APM idle hangs */
2152		apm_likes_to_melt, "Jabil AMD",
2153		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2154			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2155	},
2156	{	/* APM idle hangs */
2157		apm_likes_to_melt, "AMI Bios",
2158		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2159			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2160	},
2161	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2162		swab_apm_power_in_minutes, "Sony VAIO",
2163		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2164			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2165			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2166	},
2167	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2168		swab_apm_power_in_minutes, "Sony VAIO",
2169		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2170			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2171			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2172	},
2173	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2174		swab_apm_power_in_minutes, "Sony VAIO",
2175		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2176			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2177			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2178	},
2179	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2180		swab_apm_power_in_minutes, "Sony VAIO",
2181		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2182			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2183			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2184	},
2185	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2186		swab_apm_power_in_minutes, "Sony VAIO",
2187		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2188			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2189			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2190	},
2191	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2192		swab_apm_power_in_minutes, "Sony VAIO",
2193		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2194			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2195			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2196	},
2197	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2198		swab_apm_power_in_minutes, "Sony VAIO",
2199		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2200			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2201			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2202	},
2203	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2204		swab_apm_power_in_minutes, "Sony VAIO",
2205		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2206			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2207			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2208	},
2209	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2210		swab_apm_power_in_minutes, "Sony VAIO",
2211		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2212			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2213			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2214	},
2215	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2216		swab_apm_power_in_minutes, "Sony VAIO",
2217		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2218			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2219			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2220	},
2221
2222	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2223		swab_apm_power_in_minutes, "Sony VAIO",
2224		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2225			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2226			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2227	},
2228	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2229		swab_apm_power_in_minutes, "Sony VAIO",
2230		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2231			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2232			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2233	},
2234	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2235		swab_apm_power_in_minutes, "Sony VAIO",
2236		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2237			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2238			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2239	},
2240	{	/* broken PM poweroff bios */
2241		set_realmode_power_off, "Award Software v4.60 PGMA",
2242		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2243			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2244			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2245	},
2246
2247	/* Generic per vendor APM settings  */
2248
2249	{	/* Allow interrupts during suspend on IBM laptops */
2250		set_apm_ints, "IBM",
2251		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2252	},
2253
2254	{ }
2255};
2256
2257/*
2258 * Just start the APM thread. We do NOT want to do APM BIOS
2259 * calls from anything but the APM thread, if for no other reason
2260 * than the fact that we don't trust the APM BIOS. This way,
2261 * most common APM BIOS problems that lead to protection errors
2262 * etc will have at least some level of being contained...
2263 *
2264 * In short, if something bad happens, at least we have a choice
2265 * of just killing the apm thread..
2266 */
2267static int __init apm_init(void)
2268{
2269	struct desc_struct *gdt;
2270	int err;
2271
2272	dmi_check_system(apm_dmi_table);
2273
2274	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2275		printk(KERN_INFO "apm: BIOS not found.\n");
2276		return -ENODEV;
2277	}
2278	printk(KERN_INFO
2279	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2280	       ((apm_info.bios.version >> 8) & 0xff),
2281	       (apm_info.bios.version & 0xff),
2282	       apm_info.bios.flags,
2283	       driver_version);
2284	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2285		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2286		return -ENODEV;
2287	}
2288
2289	if (allow_ints)
2290		apm_info.allow_ints = 1;
2291	if (broken_psr)
2292		apm_info.get_power_status_broken = 1;
2293	if (realmode_power_off)
2294		apm_info.realmode_power_off = 1;
2295	/* User can override, but default is to trust DMI */
2296	if (apm_disabled != -1)
2297		apm_info.disabled = apm_disabled;
2298
2299	/*
2300	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2301	 * but is reportedly a 1.0 BIOS.
2302	 */
2303	if (apm_info.bios.version == 0x001)
2304		apm_info.bios.version = 0x100;
2305
2306	/* BIOS < 1.2 doesn't set cseg_16_len */
2307	if (apm_info.bios.version < 0x102)
2308		apm_info.bios.cseg_16_len = 0; /* 64k */
2309
2310	if (debug) {
2311		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2312			apm_info.bios.cseg, apm_info.bios.offset,
2313			apm_info.bios.cseg_16, apm_info.bios.dseg);
2314		if (apm_info.bios.version > 0x100)
2315			printk(" cseg len %x, dseg len %x",
2316				apm_info.bios.cseg_len,
2317				apm_info.bios.dseg_len);
2318		if (apm_info.bios.version > 0x101)
2319			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2320		printk("\n");
2321	}
2322
2323	if (apm_info.disabled) {
2324		pr_notice("disabled on user request.\n");
2325		return -ENODEV;
2326	}
2327	if ((num_online_cpus() > 1) && !power_off && !smp) {
2328		pr_notice("disabled - APM is not SMP safe.\n");
2329		apm_info.disabled = 1;
2330		return -ENODEV;
2331	}
2332	if (!acpi_disabled) {
2333		pr_notice("overridden by ACPI.\n");
2334		apm_info.disabled = 1;
2335		return -ENODEV;
2336	}
2337
2338	/*
2339	 * Set up the long jump entry point to the APM BIOS, which is called
2340	 * from inline assembly.
2341	 */
2342	apm_bios_entry.offset = apm_info.bios.offset;
2343	apm_bios_entry.segment = APM_CS;
2344
2345	/*
2346	 * The APM 1.1 BIOS is supposed to provide limit information that it
2347	 * recognizes.  Many machines do this correctly, but many others do
2348	 * not restrict themselves to their claimed limit.  When this happens,
2349	 * they will cause a segmentation violation in the kernel at boot time.
2350	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2351	 *
2352	 * Note we only set APM segments on CPU zero, since we pin the APM
2353	 * code to that CPU.
2354	 */
2355	gdt = get_cpu_gdt_rw(0);
2356	set_desc_base(&gdt[APM_CS >> 3],
2357		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2358	set_desc_base(&gdt[APM_CS_16 >> 3],
2359		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2360	set_desc_base(&gdt[APM_DS >> 3],
2361		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2362
2363	proc_create("apm", 0, NULL, &apm_file_ops);
2364
2365	kapmd_task = kthread_create(apm, NULL, "kapmd");
2366	if (IS_ERR(kapmd_task)) {
2367		pr_err("disabled - Unable to start kernel thread\n");
2368		err = PTR_ERR(kapmd_task);
2369		kapmd_task = NULL;
2370		remove_proc_entry("apm", NULL);
2371		return err;
2372	}
2373	wake_up_process(kapmd_task);
2374
2375	if (num_online_cpus() > 1 && !smp) {
2376		printk(KERN_NOTICE
2377		       "apm: disabled - APM is not SMP safe (power off active).\n");
2378		return 0;
2379	}
2380
2381	/*
2382	 * Note we don't actually care if the misc_device cannot be registered.
2383	 * this driver can do its job without it, even if userspace can't
2384	 * control it.  just log the error
2385	 */
2386	if (misc_register(&apm_device))
2387		printk(KERN_WARNING "apm: Could not register misc device.\n");
2388
2389	if (HZ != 100)
2390		idle_period = (idle_period * HZ) / 100;
2391	if (idle_threshold < 100) {
2392		cpuidle_poll_state_init(&apm_idle_driver);
2393		if (!cpuidle_register_driver(&apm_idle_driver))
2394			if (cpuidle_register_device(&apm_cpuidle_device))
2395				cpuidle_unregister_driver(&apm_idle_driver);
2396	}
2397
2398	return 0;
2399}
2400
2401static void __exit apm_exit(void)
2402{
2403	int error;
2404
2405	cpuidle_unregister_device(&apm_cpuidle_device);
2406	cpuidle_unregister_driver(&apm_idle_driver);
2407
2408	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2409	    && (apm_info.connection_version > 0x0100)) {
2410		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2411		if (error)
2412			apm_error("disengage power management", error);
2413	}
2414	misc_deregister(&apm_device);
2415	remove_proc_entry("apm", NULL);
2416	if (power_off)
2417		pm_power_off = NULL;
2418	if (kapmd_task) {
2419		kthread_stop(kapmd_task);
2420		kapmd_task = NULL;
2421	}
2422}
2423
2424module_init(apm_init);
2425module_exit(apm_exit);
2426
2427MODULE_AUTHOR("Stephen Rothwell");
2428MODULE_DESCRIPTION("Advanced Power Management");
2429MODULE_LICENSE("GPL");
2430module_param(debug, bool, 0644);
2431MODULE_PARM_DESC(debug, "Enable debug mode");
2432module_param(power_off, bool, 0444);
2433MODULE_PARM_DESC(power_off, "Enable power off");
2434module_param(bounce_interval, int, 0444);
2435MODULE_PARM_DESC(bounce_interval,
2436		"Set the number of ticks to ignore suspend bounces");
2437module_param(allow_ints, bool, 0444);
2438MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2439module_param(broken_psr, bool, 0444);
2440MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2441module_param(realmode_power_off, bool, 0444);
2442MODULE_PARM_DESC(realmode_power_off,
2443		"Switch to real mode before powering off");
2444module_param(idle_threshold, int, 0444);
2445MODULE_PARM_DESC(idle_threshold,
2446	"System idle percentage above which to make APM BIOS idle calls");
2447module_param(idle_period, int, 0444);
2448MODULE_PARM_DESC(idle_period,
2449	"Period (in sec/100) over which to caculate the idle percentage");
2450module_param(smp, bool, 0444);
2451MODULE_PARM_DESC(smp,
2452	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2453MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
v6.2
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* -*- linux-c -*-
   3 * APM BIOS driver for Linux
   4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   5 *
   6 * Initial development of this driver was funded by NEC Australia P/L
   7 *	and NEC Corporation
   8 *
 
 
 
 
 
 
 
 
 
 
   9 * October 1995, Rik Faith (faith@cs.unc.edu):
  10 *    Minor enhancements and updates (to the patch set) for 1.3.x
  11 *    Documentation
  12 * January 1996, Rik Faith (faith@cs.unc.edu):
  13 *    Make /proc/apm easy to format (bump driver version)
  14 * March 1996, Rik Faith (faith@cs.unc.edu):
  15 *    Prohibit APM BIOS calls unless apm_enabled.
  16 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  18 *    Version 1.0 and 1.1
  19 * May 1996, Version 1.2
  20 * Feb 1998, Version 1.3
  21 * Feb 1998, Version 1.4
  22 * Aug 1998, Version 1.5
  23 * Sep 1998, Version 1.6
  24 * Nov 1998, Version 1.7
  25 * Jan 1999, Version 1.8
  26 * Jan 1999, Version 1.9
  27 * Oct 1999, Version 1.10
  28 * Nov 1999, Version 1.11
  29 * Jan 2000, Version 1.12
  30 * Feb 2000, Version 1.13
  31 * Nov 2000, Version 1.14
  32 * Oct 2001, Version 1.15
  33 * Jan 2002, Version 1.16
  34 * Oct 2002, Version 1.16ac
  35 *
  36 * History:
  37 *    0.6b: first version in official kernel, Linux 1.3.46
  38 *    0.7: changed /proc/apm format, Linux 1.3.58
  39 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  40 *    0.9: only call bios if bios is present, Linux 1.3.72
  41 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  42 *         Linux 1.3.85
  43 *    1.1: support user-space standby and suspend, power off after system
  44 *         halted, Linux 1.3.98
  45 *    1.2: When resetting RTC after resume, take care so that the time
  46 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  47 *         <jtoth@princeton.edu>); improve interaction between
  48 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  49 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  50 *	   levels to the printk calls. APM is not defined for SMP machines.
  51 *         The new replacement for it is, but Linux doesn't yet support this.
  52 *         Alan Cox Linux 2.1.55
  53 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  54 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  55 *         Dean Gaudet <dgaudet@arctic.org>.
  56 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  57 *    1.5: Fix segment register reloading (in case of bad segments saved
  58 *         across BIOS call).
  59 *         Stephen Rothwell
  60 *    1.6: Cope with compiler/assembler differences.
  61 *         Only try to turn off the first display device.
  62 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  63 *                   <echter@informatik.uni-rostock.de>
  64 *         Stephen Rothwell
  65 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  66 *         to reflect current state of APM BIOS.
  67 *         Chris Rankin <rankinc@bellsouth.net>
  68 *         Reset interrupt 0 timer to 100Hz after suspend
  69 *         Chad Miller <cmiller@surfsouth.com>
  70 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  71 *         Richard Gooch <rgooch@atnf.csiro.au>
  72 *         Allow boot time disabling of APM
  73 *         Make boot messages far less verbose by default
  74 *         Make asm safer
  75 *         Stephen Rothwell
  76 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  77 *         Richard Gooch <rgooch@atnf.csiro.au>
  78 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  79 *         remove dependency on CONFIG_PROC_FS
  80 *         Stephen Rothwell
  81 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  82 *         Try to cope with BIOS's that need to have all display
  83 *         devices blanked and not just the first one.
  84 *         Ross Paterson <ross@soi.city.ac.uk>
  85 *         Fix segment limit setting it has always been wrong as
  86 *         the segments needed to have byte granularity.
  87 *         Mark a few things __init.
  88 *         Add hack to allow power off of SMP systems by popular request.
  89 *         Use CONFIG_SMP instead of __SMP__
  90 *         Ignore BOUNCES for three seconds.
  91 *         Stephen Rothwell
  92 *   1.10: Fix for Thinkpad return code.
  93 *         Merge 2.2 and 2.3 drivers.
  94 *         Remove APM dependencies in arch/i386/kernel/process.c
  95 *         Remove APM dependencies in drivers/char/sysrq.c
  96 *         Reset time across standby.
  97 *         Allow more initialisation on SMP.
  98 *         Remove CONFIG_APM_POWER_OFF and make it boot time
  99 *         configurable (default on).
 100 *         Make debug only a boot time parameter (remove APM_DEBUG).
 101 *         Try to blank all devices on any error.
 102 *   1.11: Remove APM dependencies in drivers/char/console.c
 103 *         Check nr_running to detect if we are idle (from
 104 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 105 *         Fix for bioses that don't zero the top part of the
 106 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 107 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 108 *         Real mode power off patch (Walter Hofmann
 109 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 110 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 111 *         the code away anyway (smp_num_cpus == 1 in UP)
 112 *         noted by Artur Skawina <skawina@geocities.com>.
 113 *         Make power off under SMP work again.
 114 *         Fix thinko with initial engaging of BIOS.
 115 *         Make sure power off only happens on CPU 0
 116 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 117 *         Do error notification to user mode if BIOS calls fail.
 118 *         Move entrypoint offset fix to ...boot/setup.S
 119 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 120 *         Remove smp-power-off. SMP users must now specify
 121 *         "apm=power-off" on the kernel command line. Suggested
 122 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 123 *         <alan@lxorguk.ukuu.org.uk>.
 124 *         Register the /proc/apm entry even on SMP so that
 125 *         scripts that check for it before doing power off
 126 *         work (Jim Avera <jima@hal.com>).
 127 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 128 *         <andy_henroid@yahoo.com>).
 129 *         Modularize the code.
 130 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 131 *         is now the way life works).
 132 *         Fix thinko in suspend() (wrong return).
 133 *         Notify drivers on critical suspend.
 134 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 135 *         modified by sfr).
 136 *         Disable interrupts while we are suspended (Andy Henroid
 137 *         <andy_henroid@yahoo.com> fixed by sfr).
 138 *         Make power off work on SMP again (Tony Hoyle
 139 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 140 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 141 *         interval is now configurable.
 142 *   1.14: Make connection version persist across module unload/load.
 143 *         Enable and engage power management earlier.
 144 *         Disengage power management on module unload.
 145 *         Changed to use the sysrq-register hack for registering the
 146 *         power off function called by magic sysrq based upon discussions
 147 *         in irc://irc.openprojects.net/#kernelnewbies
 148 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 149 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 150 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 151 *         Work around byte swap bug in one of the Vaio's BIOS's
 152 *         (Marc Boucher <marc@mbsi.ca>).
 153 *         Exposed the disable flag to dmi so that we can handle known
 154 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 155 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 156 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 157 *         If an APM idle fails log it and idle sensibly
 158 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 159 *         Don't expect replies from clients who open the device O_RDONLY.
 160 *         (Idea from Thomas Hood)
 161 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 162 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 163 *         Notify listeners of standby or suspend events before notifying
 164 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 165 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 166 *         Ignore first resume after we generate our own resume event
 167 *         after a suspend (Thomas Hood)
 168 *         Daemonize now gets rid of our controlling terminal (sfr).
 169 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 170 *         idle_threshold (sfr).
 171 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 172 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 173 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 174 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 175 *
 176 * APM 1.1 Reference:
 177 *
 178 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 179 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 180 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 181 *
 182 * [This document is available free from Intel by calling 800.628.8686 (fax
 183 * 916.356.6100) or 800.548.4725; or from
 184 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 185 * available from Microsoft by calling 206.882.8080.]
 186 *
 187 * APM 1.2 Reference:
 188 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 189 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 190 *
 191 * [This document is available from Microsoft at:
 192 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 193 */
 194
 195#define pr_fmt(fmt) "apm: " fmt
 196
 197#include <linux/module.h>
 198
 199#include <linux/poll.h>
 200#include <linux/types.h>
 201#include <linux/stddef.h>
 202#include <linux/timer.h>
 203#include <linux/fcntl.h>
 204#include <linux/slab.h>
 205#include <linux/stat.h>
 206#include <linux/proc_fs.h>
 207#include <linux/seq_file.h>
 208#include <linux/miscdevice.h>
 209#include <linux/apm_bios.h>
 210#include <linux/init.h>
 211#include <linux/time.h>
 212#include <linux/sched/signal.h>
 213#include <linux/sched/cputime.h>
 214#include <linux/pm.h>
 215#include <linux/capability.h>
 216#include <linux/device.h>
 217#include <linux/kernel.h>
 218#include <linux/freezer.h>
 219#include <linux/smp.h>
 220#include <linux/dmi.h>
 221#include <linux/suspend.h>
 222#include <linux/kthread.h>
 223#include <linux/jiffies.h>
 224#include <linux/acpi.h>
 225#include <linux/syscore_ops.h>
 226#include <linux/i8253.h>
 227#include <linux/cpuidle.h>
 228
 229#include <linux/uaccess.h>
 230#include <asm/desc.h>
 231#include <asm/olpc.h>
 232#include <asm/paravirt.h>
 233#include <asm/reboot.h>
 234#include <asm/nospec-branch.h>
 235#include <asm/ibt.h>
 236
 237#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 238extern int (*console_blank_hook)(int);
 239#endif
 240
 241/*
 242 * The apm_bios device is one of the misc char devices.
 243 * This is its minor number.
 244 */
 245#define	APM_MINOR_DEV	134
 246
 247/*
 248 * Various options can be changed at boot time as follows:
 249 * (We allow underscores for compatibility with the modules code)
 250 *	apm=on/off			enable/disable APM
 251 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 252 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 253 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 254 *	    					powering off
 255 *	    [no-]debug			log some debugging messages
 256 *	    [no-]power[-_]off		power off on shutdown
 257 *	    [no-]smp			Use apm even on an SMP box
 258 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 259 *	    				bounces
 260 *          idle[-_]threshold=<n>       System idle percentage above which to
 261 *                                      make APM BIOS idle calls. Set it to
 262 *                                      100 to disable.
 263 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 264 *                                      which the idle percentage is
 265 *                                      calculated.
 266 */
 267
 268/* KNOWN PROBLEM MACHINES:
 269 *
 270 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 271 *                         [Confirmed by TI representative]
 272 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 273 *                    [Confirmed by BIOS disassembly]
 274 *                    [This may work now ...]
 275 * P: Toshiba 1950S: battery life information only gets updated after resume
 276 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 277 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 278 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 279 * 	Neale Banks <neale@lowendale.com.au> December 2000
 280 *
 281 * Legend: U = unusable with APM patches
 282 *         P = partially usable with APM patches
 283 */
 284
 285/*
 286 * Define as 1 to make the driver always call the APM BIOS busy
 287 * routine even if the clock was not reported as slowed by the
 288 * idle routine.  Otherwise, define as 0.
 289 */
 290#define ALWAYS_CALL_BUSY   1
 291
 292/*
 293 * Define to make the APM BIOS calls zero all data segment registers (so
 294 * that an incorrect BIOS implementation will cause a kernel panic if it
 295 * tries to write to arbitrary memory).
 296 */
 297#define APM_ZERO_SEGS
 298
 299#include <asm/apm.h>
 300
 301/*
 302 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 303 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 304 * David Chen <chen@ctpa04.mit.edu>
 305 */
 306#undef INIT_TIMER_AFTER_SUSPEND
 307
 308#ifdef INIT_TIMER_AFTER_SUSPEND
 309#include <linux/timex.h>
 310#include <asm/io.h>
 311#include <linux/delay.h>
 312#endif
 313
 314/*
 315 * Need to poll the APM BIOS every second
 316 */
 317#define APM_CHECK_TIMEOUT	(HZ)
 318
 319/*
 320 * Ignore suspend events for this amount of time after a resume
 321 */
 322#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 323
 324/*
 325 * Maximum number of events stored
 326 */
 327#define APM_MAX_EVENTS		20
 328
 329/*
 330 * The per-file APM data
 331 */
 332struct apm_user {
 333	int		magic;
 334	struct apm_user *next;
 335	unsigned int	suser: 1;
 336	unsigned int	writer: 1;
 337	unsigned int	reader: 1;
 338	unsigned int	suspend_wait: 1;
 339	int		suspend_result;
 340	int		suspends_pending;
 341	int		standbys_pending;
 342	int		suspends_read;
 343	int		standbys_read;
 344	int		event_head;
 345	int		event_tail;
 346	apm_event_t	events[APM_MAX_EVENTS];
 347};
 348
 349/*
 350 * The magic number in apm_user
 351 */
 352#define APM_BIOS_MAGIC		0x4101
 353
 354/*
 355 * idle percentage above which bios idle calls are done
 356 */
 357#ifdef CONFIG_APM_CPU_IDLE
 358#define DEFAULT_IDLE_THRESHOLD	95
 359#else
 360#define DEFAULT_IDLE_THRESHOLD	100
 361#endif
 362#define DEFAULT_IDLE_PERIOD	(100 / 3)
 363
 364static int apm_cpu_idle(struct cpuidle_device *dev,
 365			struct cpuidle_driver *drv, int index);
 366
 367static struct cpuidle_driver apm_idle_driver = {
 368	.name = "apm_idle",
 369	.owner = THIS_MODULE,
 370	.states = {
 371		{ /* entry 0 is for polling */ },
 372		{ /* entry 1 is for APM idle */
 373			.name = "APM",
 374			.desc = "APM idle",
 375			.exit_latency = 250,	/* WAG */
 376			.target_residency = 500,	/* WAG */
 377			.enter = &apm_cpu_idle
 378		},
 379	},
 380	.state_count = 2,
 381};
 382
 383static struct cpuidle_device apm_cpuidle_device;
 384
 385/*
 386 * Local variables
 387 */
 388__visible struct {
 389	unsigned long	offset;
 390	unsigned short	segment;
 391} apm_bios_entry;
 392static int clock_slowed;
 393static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 394static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 395static int suspends_pending;
 396static int standbys_pending;
 397static int ignore_sys_suspend;
 398static int ignore_normal_resume;
 399static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 400
 401static bool debug __read_mostly;
 402static bool smp __read_mostly;
 403static int apm_disabled = -1;
 404#ifdef CONFIG_SMP
 405static bool power_off;
 406#else
 407static bool power_off = 1;
 408#endif
 409static bool realmode_power_off;
 410#ifdef CONFIG_APM_ALLOW_INTS
 411static bool allow_ints = 1;
 412#else
 413static bool allow_ints;
 414#endif
 415static bool broken_psr;
 416
 417static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 418static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 419static struct apm_user *user_list;
 420static DEFINE_SPINLOCK(user_list_lock);
 421static DEFINE_MUTEX(apm_mutex);
 422
 423/*
 424 * Set up a segment that references the real mode segment 0x40
 425 * that extends up to the end of page zero (that we have reserved).
 426 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 427 * even though they are called in protected mode.
 428 */
 429static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
 430			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 431
 432static const char driver_version[] = "1.16ac";	/* no spaces */
 433
 434static struct task_struct *kapmd_task;
 435
 436/*
 437 *	APM event names taken from the APM 1.2 specification. These are
 438 *	the message codes that the BIOS uses to tell us about events
 439 */
 440static const char * const apm_event_name[] = {
 441	"system standby",
 442	"system suspend",
 443	"normal resume",
 444	"critical resume",
 445	"low battery",
 446	"power status change",
 447	"update time",
 448	"critical suspend",
 449	"user standby",
 450	"user suspend",
 451	"system standby resume",
 452	"capabilities change"
 453};
 454#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 455
 456typedef struct lookup_t {
 457	int	key;
 458	char 	*msg;
 459} lookup_t;
 460
 461/*
 462 *	The BIOS returns a set of standard error codes in AX when the
 463 *	carry flag is set.
 464 */
 465
 466static const lookup_t error_table[] = {
 467/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 468	{ APM_DISABLED,		"Power management disabled" },
 469	{ APM_CONNECTED,	"Real mode interface already connected" },
 470	{ APM_NOT_CONNECTED,	"Interface not connected" },
 471	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 472/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 473	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 474	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 475	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 476	{ APM_BAD_PARAM,	"Parameter out of range" },
 477	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 478	{ APM_BAD_FUNCTION,     "Function not supported" },
 479	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 480	{ APM_BAD_STATE,	"Unable to enter requested state" },
 481/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 482	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 483	{ APM_NOT_PRESENT,	"No APM present" }
 484};
 485#define ERROR_COUNT	ARRAY_SIZE(error_table)
 486
 487/**
 488 *	apm_error	-	display an APM error
 489 *	@str: information string
 490 *	@err: APM BIOS return code
 491 *
 492 *	Write a meaningful log entry to the kernel log in the event of
 493 *	an APM error.  Note that this also handles (negative) kernel errors.
 494 */
 495
 496static void apm_error(char *str, int err)
 497{
 498	int i;
 499
 500	for (i = 0; i < ERROR_COUNT; i++)
 501		if (error_table[i].key == err)
 502			break;
 503	if (i < ERROR_COUNT)
 504		pr_notice("%s: %s\n", str, error_table[i].msg);
 505	else if (err < 0)
 506		pr_notice("%s: linux error code %i\n", str, err);
 507	else
 508		pr_notice("%s: unknown error code %#2.2x\n",
 509		       str, err);
 510}
 511
 512/*
 513 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 514 * apm_info.allow_ints, we are being really paranoid here!  Not only
 515 * are interrupts disabled, but all the segment registers (except SS)
 516 * are saved and zeroed this means that if the BIOS tries to reference
 517 * any data without explicitly loading the segment registers, the kernel
 518 * will fault immediately rather than have some unforeseen circumstances
 519 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 520 * this depends on CS referring to the same physical memory as DS so that
 521 * DS can be zeroed before the call. Unfortunately, we can't do anything
 522 * about the stack segment/pointer.  Also, we tell the compiler that
 523 * everything could change.
 524 *
 525 * Also, we KNOW that for the non error case of apm_bios_call, there
 526 * is no useful data returned in the low order 8 bits of eax.
 527 */
 528
 529static inline unsigned long __apm_irq_save(void)
 530{
 531	unsigned long flags;
 532	local_save_flags(flags);
 533	if (apm_info.allow_ints) {
 534		if (irqs_disabled_flags(flags))
 535			local_irq_enable();
 536	} else
 537		local_irq_disable();
 538
 539	return flags;
 540}
 541
 542#define apm_irq_save(flags) \
 543	do { flags = __apm_irq_save(); } while (0)
 544
 545static inline void apm_irq_restore(unsigned long flags)
 546{
 547	if (irqs_disabled_flags(flags))
 548		local_irq_disable();
 549	else if (irqs_disabled())
 550		local_irq_enable();
 551}
 552
 553#ifdef APM_ZERO_SEGS
 554#	define APM_DECL_SEGS \
 555		unsigned int saved_fs; unsigned int saved_gs;
 556#	define APM_DO_SAVE_SEGS \
 557		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 558#	define APM_DO_RESTORE_SEGS \
 559		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 560#else
 561#	define APM_DECL_SEGS
 562#	define APM_DO_SAVE_SEGS
 563#	define APM_DO_RESTORE_SEGS
 564#endif
 565
 566struct apm_bios_call {
 567	u32 func;
 568	/* In and out */
 569	u32 ebx;
 570	u32 ecx;
 571	/* Out only */
 572	u32 eax;
 573	u32 edx;
 574	u32 esi;
 575
 576	/* Error: -ENOMEM, or bits 8-15 of eax */
 577	int err;
 578};
 579
 580/**
 581 *	__apm_bios_call - Make an APM BIOS 32bit call
 582 *	@_call: pointer to struct apm_bios_call.
 583 *
 584 *	Make an APM call using the 32bit protected mode interface. The
 585 *	caller is responsible for knowing if APM BIOS is configured and
 586 *	enabled. This call can disable interrupts for a long period of
 587 *	time on some laptops.  The return value is in AH and the carry
 588 *	flag is loaded into AL.  If there is an error, then the error
 589 *	code is returned in AH (bits 8-15 of eax) and this function
 590 *	returns non-zero.
 591 *
 592 *	Note: this makes the call on the current CPU.
 593 */
 594static long __apm_bios_call(void *_call)
 595{
 596	APM_DECL_SEGS
 597	unsigned long		flags;
 598	int			cpu;
 599	struct desc_struct	save_desc_40;
 600	struct desc_struct	*gdt;
 601	struct apm_bios_call	*call = _call;
 602	u64			ibt;
 603
 604	cpu = get_cpu();
 605	BUG_ON(cpu != 0);
 606	gdt = get_cpu_gdt_rw(cpu);
 607	save_desc_40 = gdt[0x40 / 8];
 608	gdt[0x40 / 8] = bad_bios_desc;
 609
 610	apm_irq_save(flags);
 611	firmware_restrict_branch_speculation_start();
 612	ibt = ibt_save();
 613	APM_DO_SAVE_SEGS;
 614	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 615			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 616			  &call->esi);
 617	APM_DO_RESTORE_SEGS;
 618	ibt_restore(ibt);
 619	firmware_restrict_branch_speculation_end();
 620	apm_irq_restore(flags);
 621	gdt[0x40 / 8] = save_desc_40;
 622	put_cpu();
 623
 624	return call->eax & 0xff;
 625}
 626
 627/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 628static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 629{
 630	int ret;
 631
 632	/* Don't bother with work_on_cpu in the common case, so we don't
 633	 * have to worry about OOM or overhead. */
 634	if (get_cpu() == 0) {
 635		ret = fn(call);
 636		put_cpu();
 637	} else {
 638		put_cpu();
 639		ret = work_on_cpu(0, fn, call);
 640	}
 641
 642	/* work_on_cpu can fail with -ENOMEM */
 643	if (ret < 0)
 644		call->err = ret;
 645	else
 646		call->err = (call->eax >> 8) & 0xff;
 647
 648	return ret;
 649}
 650
 651/**
 652 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 653 *	@call: the apm_bios_call registers.
 654 *
 655 *	If there is an error, it is returned in @call.err.
 656 */
 657static int apm_bios_call(struct apm_bios_call *call)
 658{
 659	return on_cpu0(__apm_bios_call, call);
 660}
 661
 662/**
 663 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 664 *	@_call: pointer to struct apm_bios_call.
 665 *
 666 *	Make a BIOS call that returns one value only, or just status.
 667 *	If there is an error, then the error code is returned in AH
 668 *	(bits 8-15 of eax) and this function returns non-zero (it can
 669 *	also return -ENOMEM). This is used for simpler BIOS operations.
 670 *	This call may hold interrupts off for a long time on some laptops.
 671 *
 672 *	Note: this makes the call on the current CPU.
 673 */
 674static long __apm_bios_call_simple(void *_call)
 675{
 676	u8			error;
 677	APM_DECL_SEGS
 678	unsigned long		flags;
 679	int			cpu;
 680	struct desc_struct	save_desc_40;
 681	struct desc_struct	*gdt;
 682	struct apm_bios_call	*call = _call;
 683	u64			ibt;
 684
 685	cpu = get_cpu();
 686	BUG_ON(cpu != 0);
 687	gdt = get_cpu_gdt_rw(cpu);
 688	save_desc_40 = gdt[0x40 / 8];
 689	gdt[0x40 / 8] = bad_bios_desc;
 690
 691	apm_irq_save(flags);
 692	firmware_restrict_branch_speculation_start();
 693	ibt = ibt_save();
 694	APM_DO_SAVE_SEGS;
 695	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 696					 &call->eax);
 697	APM_DO_RESTORE_SEGS;
 698	ibt_restore(ibt);
 699	firmware_restrict_branch_speculation_end();
 700	apm_irq_restore(flags);
 701	gdt[0x40 / 8] = save_desc_40;
 702	put_cpu();
 703	return error;
 704}
 705
 706/**
 707 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 708 *	@func: APM function to invoke
 709 *	@ebx_in: EBX register value for BIOS call
 710 *	@ecx_in: ECX register value for BIOS call
 711 *	@eax: EAX register on return from the BIOS call
 712 *	@err: bits
 713 *
 714 *	Make a BIOS call that returns one value only, or just status.
 715 *	If there is an error, then the error code is returned in @err
 716 *	and this function returns non-zero. This is used for simpler
 717 *	BIOS operations.  This call may hold interrupts off for a long
 718 *	time on some laptops.
 719 */
 720static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 721				int *err)
 722{
 723	struct apm_bios_call call;
 724	int ret;
 725
 726	call.func = func;
 727	call.ebx = ebx_in;
 728	call.ecx = ecx_in;
 729
 730	ret = on_cpu0(__apm_bios_call_simple, &call);
 731	*eax = call.eax;
 732	*err = call.err;
 733	return ret;
 734}
 735
 736/**
 737 *	apm_driver_version	-	APM driver version
 738 *	@val:	loaded with the APM version on return
 739 *
 740 *	Retrieve the APM version supported by the BIOS. This is only
 741 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 742 *	probably present.
 743 *
 744 *	On entry val should point to a value indicating the APM driver
 745 *	version with the high byte being the major and the low byte the
 746 *	minor number both in BCD
 747 *
 748 *	On return it will hold the BIOS revision supported in the
 749 *	same format.
 750 */
 751
 752static int apm_driver_version(u_short *val)
 753{
 754	u32 eax;
 755	int err;
 756
 757	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 758		return err;
 759	*val = eax;
 760	return APM_SUCCESS;
 761}
 762
 763/**
 764 *	apm_get_event	-	get an APM event from the BIOS
 765 *	@event: pointer to the event
 766 *	@info: point to the event information
 767 *
 768 *	The APM BIOS provides a polled information for event
 769 *	reporting. The BIOS expects to be polled at least every second
 770 *	when events are pending. When a message is found the caller should
 771 *	poll until no more messages are present.  However, this causes
 772 *	problems on some laptops where a suspend event notification is
 773 *	not cleared until it is acknowledged.
 774 *
 775 *	Additional information is returned in the info pointer, providing
 776 *	that APM 1.2 is in use. If no messages are pending the value 0x80
 777 *	is returned (No power management events pending).
 778 */
 779static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 780{
 781	struct apm_bios_call call;
 782
 783	call.func = APM_FUNC_GET_EVENT;
 784	call.ebx = call.ecx = 0;
 785
 786	if (apm_bios_call(&call))
 787		return call.err;
 788
 789	*event = call.ebx;
 790	if (apm_info.connection_version < 0x0102)
 791		*info = ~0; /* indicate info not valid */
 792	else
 793		*info = call.ecx;
 794	return APM_SUCCESS;
 795}
 796
 797/**
 798 *	set_power_state	-	set the power management state
 799 *	@what: which items to transition
 800 *	@state: state to transition to
 801 *
 802 *	Request an APM change of state for one or more system devices. The
 803 *	processor state must be transitioned last of all. what holds the
 804 *	class of device in the upper byte and the device number (0xFF for
 805 *	all) for the object to be transitioned.
 806 *
 807 *	The state holds the state to transition to, which may in fact
 808 *	be an acceptance of a BIOS requested state change.
 809 */
 810
 811static int set_power_state(u_short what, u_short state)
 812{
 813	u32 eax;
 814	int err;
 815
 816	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 817		return err;
 818	return APM_SUCCESS;
 819}
 820
 821/**
 822 *	set_system_power_state - set system wide power state
 823 *	@state: which state to enter
 824 *
 825 *	Transition the entire system into a new APM power state.
 826 */
 827
 828static int set_system_power_state(u_short state)
 829{
 830	return set_power_state(APM_DEVICE_ALL, state);
 831}
 832
 833/**
 834 *	apm_do_idle	-	perform power saving
 835 *
 836 *	This function notifies the BIOS that the processor is (in the view
 837 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 838 *	to handle the idle request. On a success the function returns 1
 839 *	if the BIOS did clock slowing or 0 otherwise.
 840 */
 841
 842static int apm_do_idle(void)
 843{
 844	u32 eax;
 845	u8 ret = 0;
 846	int idled = 0;
 847	int err = 0;
 848
 849	if (!need_resched()) {
 850		idled = 1;
 851		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 852	}
 853
 854	if (!idled)
 855		return 0;
 856
 857	if (ret) {
 858		static unsigned long t;
 859
 860		/* This always fails on some SMP boards running UP kernels.
 861		 * Only report the failure the first 5 times.
 862		 */
 863		if (++t < 5) {
 864			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 865			t = jiffies;
 866		}
 867		return -1;
 868	}
 869	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 870	return clock_slowed;
 871}
 872
 873/**
 874 *	apm_do_busy	-	inform the BIOS the CPU is busy
 875 *
 876 *	Request that the BIOS brings the CPU back to full performance.
 877 */
 878
 879static void apm_do_busy(void)
 880{
 881	u32 dummy;
 882	int err;
 883
 884	if (clock_slowed || ALWAYS_CALL_BUSY) {
 885		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 886		clock_slowed = 0;
 887	}
 888}
 889
 890/*
 891 * If no process has really been interested in
 892 * the CPU for some time, we want to call BIOS
 893 * power management - we probably want
 894 * to conserve power.
 895 */
 896#define IDLE_CALC_LIMIT	(HZ * 100)
 897#define IDLE_LEAKY_MAX	16
 898
 899/**
 900 * apm_cpu_idle		-	cpu idling for APM capable Linux
 901 *
 902 * This is the idling function the kernel executes when APM is available. It
 903 * tries to do BIOS powermanagement based on the average system idle time.
 904 * Furthermore it calls the system default idle routine.
 905 */
 906
 907static int apm_cpu_idle(struct cpuidle_device *dev,
 908	struct cpuidle_driver *drv, int index)
 909{
 910	static int use_apm_idle; /* = 0 */
 911	static unsigned int last_jiffies; /* = 0 */
 912	static u64 last_stime; /* = 0 */
 913	u64 stime, utime;
 914
 915	int apm_idle_done = 0;
 916	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 917	unsigned int bucket;
 918
 919recalc:
 920	task_cputime(current, &utime, &stime);
 921	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 922		use_apm_idle = 0;
 923	} else if (jiffies_since_last_check > idle_period) {
 924		unsigned int idle_percentage;
 925
 926		idle_percentage = nsecs_to_jiffies(stime - last_stime);
 927		idle_percentage *= 100;
 928		idle_percentage /= jiffies_since_last_check;
 929		use_apm_idle = (idle_percentage > idle_threshold);
 930		if (apm_info.forbid_idle)
 931			use_apm_idle = 0;
 932	}
 933
 934	last_jiffies = jiffies;
 935	last_stime = stime;
 936
 937	bucket = IDLE_LEAKY_MAX;
 938
 939	while (!need_resched()) {
 940		if (use_apm_idle) {
 941			unsigned int t;
 942
 943			t = jiffies;
 944			switch (apm_do_idle()) {
 945			case 0:
 946				apm_idle_done = 1;
 947				if (t != jiffies) {
 948					if (bucket) {
 949						bucket = IDLE_LEAKY_MAX;
 950						continue;
 951					}
 952				} else if (bucket) {
 953					bucket--;
 954					continue;
 955				}
 956				break;
 957			case 1:
 958				apm_idle_done = 1;
 959				break;
 960			default: /* BIOS refused */
 961				break;
 962			}
 963		}
 964		default_idle();
 965		local_irq_disable();
 966		jiffies_since_last_check = jiffies - last_jiffies;
 967		if (jiffies_since_last_check > idle_period)
 968			goto recalc;
 969	}
 970
 971	if (apm_idle_done)
 972		apm_do_busy();
 973
 974	return index;
 975}
 976
 977/**
 978 *	apm_power_off	-	ask the BIOS to power off
 979 *
 980 *	Handle the power off sequence. This is the one piece of code we
 981 *	will execute even on SMP machines. In order to deal with BIOS
 982 *	bugs we support real mode APM BIOS power off calls. We also make
 983 *	the SMP call on CPU0 as some systems will only honour this call
 984 *	on their first cpu.
 985 */
 986
 987static void apm_power_off(void)
 988{
 989	/* Some bioses don't like being called from CPU != 0 */
 990	if (apm_info.realmode_power_off) {
 991		set_cpus_allowed_ptr(current, cpumask_of(0));
 992		machine_real_restart(MRR_APM);
 993	} else {
 994		(void)set_system_power_state(APM_STATE_OFF);
 995	}
 996}
 997
 998#ifdef CONFIG_APM_DO_ENABLE
 999
1000/**
1001 *	apm_enable_power_management - enable BIOS APM power management
1002 *	@enable: enable yes/no
1003 *
1004 *	Enable or disable the APM BIOS power services.
1005 */
1006
1007static int apm_enable_power_management(int enable)
1008{
1009	u32 eax;
1010	int err;
1011
1012	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1013		return APM_NOT_ENGAGED;
1014	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1015				 enable, &eax, &err))
1016		return err;
1017	if (enable)
1018		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1019	else
1020		apm_info.bios.flags |= APM_BIOS_DISABLED;
1021	return APM_SUCCESS;
1022}
1023#endif
1024
1025/**
1026 *	apm_get_power_status	-	get current power state
1027 *	@status: returned status
1028 *	@bat: battery info
1029 *	@life: estimated life
1030 *
1031 *	Obtain the current power status from the APM BIOS. We return a
1032 *	status which gives the rough battery status, and current power
1033 *	source. The bat value returned give an estimate as a percentage
1034 *	of life and a status value for the battery. The estimated life
1035 *	if reported is a lifetime in seconds/minutes at current power
1036 *	consumption.
1037 */
1038
1039static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1040{
1041	struct apm_bios_call call;
1042
1043	call.func = APM_FUNC_GET_STATUS;
1044	call.ebx = APM_DEVICE_ALL;
1045	call.ecx = 0;
1046
1047	if (apm_info.get_power_status_broken)
1048		return APM_32_UNSUPPORTED;
1049	if (apm_bios_call(&call)) {
1050		if (!call.err)
1051			return APM_NO_ERROR;
1052		return call.err;
1053	}
1054	*status = call.ebx;
1055	*bat = call.ecx;
1056	if (apm_info.get_power_status_swabinminutes) {
1057		*life = swab16((u16)call.edx);
1058		*life |= 0x8000;
1059	} else
1060		*life = call.edx;
1061	return APM_SUCCESS;
1062}
1063
1064#if 0
1065static int apm_get_battery_status(u_short which, u_short *status,
1066				  u_short *bat, u_short *life, u_short *nbat)
1067{
1068	u32 eax;
1069	u32 ebx;
1070	u32 ecx;
1071	u32 edx;
1072	u32 esi;
1073
1074	if (apm_info.connection_version < 0x0102) {
1075		/* pretend we only have one battery. */
1076		if (which != 1)
1077			return APM_BAD_DEVICE;
1078		*nbat = 1;
1079		return apm_get_power_status(status, bat, life);
1080	}
1081
1082	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1083			  &ebx, &ecx, &edx, &esi))
1084		return (eax >> 8) & 0xff;
1085	*status = ebx;
1086	*bat = ecx;
1087	*life = edx;
1088	*nbat = esi;
1089	return APM_SUCCESS;
1090}
1091#endif
1092
1093/**
1094 *	apm_engage_power_management	-	enable PM on a device
1095 *	@device: identity of device
1096 *	@enable: on/off
1097 *
1098 *	Activate or deactivate power management on either a specific device
1099 *	or the entire system (%APM_DEVICE_ALL).
1100 */
1101
1102static int apm_engage_power_management(u_short device, int enable)
1103{
1104	u32 eax;
1105	int err;
1106
1107	if ((enable == 0) && (device == APM_DEVICE_ALL)
1108	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1109		return APM_DISABLED;
1110	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1111				 &eax, &err))
1112		return err;
1113	if (device == APM_DEVICE_ALL) {
1114		if (enable)
1115			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1116		else
1117			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1118	}
1119	return APM_SUCCESS;
1120}
1121
1122#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1123
1124/**
1125 *	apm_console_blank	-	blank the display
1126 *	@blank: on/off
1127 *
1128 *	Attempt to blank the console, firstly by blanking just video device
1129 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1130 *	all video devices. Typically the BIOS will do laptop backlight and
1131 *	monitor powerdown for us.
1132 */
1133
1134static int apm_console_blank(int blank)
1135{
1136	int error = APM_NOT_ENGAGED; /* silence gcc */
1137	int i;
1138	u_short state;
1139	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1140
1141	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1142
1143	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1144		error = set_power_state(dev[i], state);
1145
1146		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1147			return 1;
1148
1149		if (error == APM_NOT_ENGAGED)
1150			break;
1151	}
1152
1153	if (error == APM_NOT_ENGAGED) {
1154		static int tried;
1155		int eng_error;
1156		if (tried++ == 0) {
1157			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1158			if (eng_error) {
1159				apm_error("set display", error);
1160				apm_error("engage interface", eng_error);
1161				return 0;
1162			} else
1163				return apm_console_blank(blank);
1164		}
1165	}
1166	apm_error("set display", error);
1167	return 0;
1168}
1169#endif
1170
1171static int queue_empty(struct apm_user *as)
1172{
1173	return as->event_head == as->event_tail;
1174}
1175
1176static apm_event_t get_queued_event(struct apm_user *as)
1177{
1178	if (++as->event_tail >= APM_MAX_EVENTS)
1179		as->event_tail = 0;
1180	return as->events[as->event_tail];
1181}
1182
1183static void queue_event(apm_event_t event, struct apm_user *sender)
1184{
1185	struct apm_user *as;
1186
1187	spin_lock(&user_list_lock);
1188	if (user_list == NULL)
1189		goto out;
1190	for (as = user_list; as != NULL; as = as->next) {
1191		if ((as == sender) || (!as->reader))
1192			continue;
1193		if (++as->event_head >= APM_MAX_EVENTS)
1194			as->event_head = 0;
1195
1196		if (as->event_head == as->event_tail) {
1197			static int notified;
1198
1199			if (notified++ == 0)
1200				pr_err("an event queue overflowed\n");
1201			if (++as->event_tail >= APM_MAX_EVENTS)
1202				as->event_tail = 0;
1203		}
1204		as->events[as->event_head] = event;
1205		if (!as->suser || !as->writer)
1206			continue;
1207		switch (event) {
1208		case APM_SYS_SUSPEND:
1209		case APM_USER_SUSPEND:
1210			as->suspends_pending++;
1211			suspends_pending++;
1212			break;
1213
1214		case APM_SYS_STANDBY:
1215		case APM_USER_STANDBY:
1216			as->standbys_pending++;
1217			standbys_pending++;
1218			break;
1219		}
1220	}
1221	wake_up_interruptible(&apm_waitqueue);
1222out:
1223	spin_unlock(&user_list_lock);
1224}
1225
1226static void reinit_timer(void)
1227{
1228#ifdef INIT_TIMER_AFTER_SUSPEND
1229	unsigned long flags;
1230
1231	raw_spin_lock_irqsave(&i8253_lock, flags);
1232	/* set the clock to HZ */
1233	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1234	udelay(10);
1235	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1236	udelay(10);
1237	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1238	udelay(10);
1239	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1240#endif
1241}
1242
1243static int suspend(int vetoable)
1244{
1245	int err;
1246	struct apm_user	*as;
1247
1248	dpm_suspend_start(PMSG_SUSPEND);
1249	dpm_suspend_end(PMSG_SUSPEND);
1250
1251	local_irq_disable();
1252	syscore_suspend();
1253
1254	local_irq_enable();
1255
1256	save_processor_state();
1257	err = set_system_power_state(APM_STATE_SUSPEND);
1258	ignore_normal_resume = 1;
1259	restore_processor_state();
1260
1261	local_irq_disable();
1262	reinit_timer();
1263
1264	if (err == APM_NO_ERROR)
1265		err = APM_SUCCESS;
1266	if (err != APM_SUCCESS)
1267		apm_error("suspend", err);
1268	err = (err == APM_SUCCESS) ? 0 : -EIO;
1269
1270	syscore_resume();
1271	local_irq_enable();
1272
1273	dpm_resume_start(PMSG_RESUME);
1274	dpm_resume_end(PMSG_RESUME);
1275
1276	queue_event(APM_NORMAL_RESUME, NULL);
1277	spin_lock(&user_list_lock);
1278	for (as = user_list; as != NULL; as = as->next) {
1279		as->suspend_wait = 0;
1280		as->suspend_result = err;
1281	}
1282	spin_unlock(&user_list_lock);
1283	wake_up_interruptible(&apm_suspend_waitqueue);
1284	return err;
1285}
1286
1287static void standby(void)
1288{
1289	int err;
1290
1291	dpm_suspend_end(PMSG_SUSPEND);
1292
1293	local_irq_disable();
1294	syscore_suspend();
1295	local_irq_enable();
1296
1297	err = set_system_power_state(APM_STATE_STANDBY);
1298	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1299		apm_error("standby", err);
1300
1301	local_irq_disable();
1302	syscore_resume();
1303	local_irq_enable();
1304
1305	dpm_resume_start(PMSG_RESUME);
1306}
1307
1308static apm_event_t get_event(void)
1309{
1310	int error;
1311	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1312	apm_eventinfo_t	info;
1313
1314	static int notified;
1315
1316	/* we don't use the eventinfo */
1317	error = apm_get_event(&event, &info);
1318	if (error == APM_SUCCESS)
1319		return event;
1320
1321	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1322		apm_error("get_event", error);
1323
1324	return 0;
1325}
1326
1327static void check_events(void)
1328{
1329	apm_event_t event;
1330	static unsigned long last_resume;
1331	static int ignore_bounce;
1332
1333	while ((event = get_event()) != 0) {
1334		if (debug) {
1335			if (event <= NR_APM_EVENT_NAME)
1336				printk(KERN_DEBUG "apm: received %s notify\n",
1337				       apm_event_name[event - 1]);
1338			else
1339				printk(KERN_DEBUG "apm: received unknown "
1340				       "event 0x%02x\n", event);
1341		}
1342		if (ignore_bounce
1343		    && (time_after(jiffies, last_resume + bounce_interval)))
1344			ignore_bounce = 0;
1345
1346		switch (event) {
1347		case APM_SYS_STANDBY:
1348		case APM_USER_STANDBY:
1349			queue_event(event, NULL);
1350			if (standbys_pending <= 0)
1351				standby();
1352			break;
1353
1354		case APM_USER_SUSPEND:
1355#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1356			if (apm_info.connection_version > 0x100)
1357				set_system_power_state(APM_STATE_REJECT);
1358			break;
1359#endif
1360		case APM_SYS_SUSPEND:
1361			if (ignore_bounce) {
1362				if (apm_info.connection_version > 0x100)
1363					set_system_power_state(APM_STATE_REJECT);
1364				break;
1365			}
1366			/*
1367			 * If we are already processing a SUSPEND,
1368			 * then further SUSPEND events from the BIOS
1369			 * will be ignored.  We also return here to
1370			 * cope with the fact that the Thinkpads keep
1371			 * sending a SUSPEND event until something else
1372			 * happens!
1373			 */
1374			if (ignore_sys_suspend)
1375				return;
1376			ignore_sys_suspend = 1;
1377			queue_event(event, NULL);
1378			if (suspends_pending <= 0)
1379				(void) suspend(1);
1380			break;
1381
1382		case APM_NORMAL_RESUME:
1383		case APM_CRITICAL_RESUME:
1384		case APM_STANDBY_RESUME:
1385			ignore_sys_suspend = 0;
1386			last_resume = jiffies;
1387			ignore_bounce = 1;
1388			if ((event != APM_NORMAL_RESUME)
1389			    || (ignore_normal_resume == 0)) {
1390				dpm_resume_end(PMSG_RESUME);
1391				queue_event(event, NULL);
1392			}
1393			ignore_normal_resume = 0;
1394			break;
1395
1396		case APM_CAPABILITY_CHANGE:
1397		case APM_LOW_BATTERY:
1398		case APM_POWER_STATUS_CHANGE:
1399			queue_event(event, NULL);
1400			/* If needed, notify drivers here */
1401			break;
1402
1403		case APM_UPDATE_TIME:
1404			break;
1405
1406		case APM_CRITICAL_SUSPEND:
1407			/*
1408			 * We are not allowed to reject a critical suspend.
1409			 */
1410			(void)suspend(0);
1411			break;
1412		}
1413	}
1414}
1415
1416static void apm_event_handler(void)
1417{
1418	static int pending_count = 4;
1419	int err;
1420
1421	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1422		if ((apm_info.connection_version > 0x100) &&
1423		    (pending_count-- <= 0)) {
1424			pending_count = 4;
1425			if (debug)
1426				printk(KERN_DEBUG "apm: setting state busy\n");
1427			err = set_system_power_state(APM_STATE_BUSY);
1428			if (err)
1429				apm_error("busy", err);
1430		}
1431	} else
1432		pending_count = 4;
1433	check_events();
1434}
1435
1436/*
1437 * This is the APM thread main loop.
1438 */
1439
1440static void apm_mainloop(void)
1441{
1442	DECLARE_WAITQUEUE(wait, current);
1443
1444	add_wait_queue(&apm_waitqueue, &wait);
1445	set_current_state(TASK_INTERRUPTIBLE);
1446	for (;;) {
1447		schedule_timeout(APM_CHECK_TIMEOUT);
1448		if (kthread_should_stop())
1449			break;
1450		/*
1451		 * Ok, check all events, check for idle (and mark us sleeping
1452		 * so as not to count towards the load average)..
1453		 */
1454		set_current_state(TASK_INTERRUPTIBLE);
1455		apm_event_handler();
1456	}
1457	remove_wait_queue(&apm_waitqueue, &wait);
1458}
1459
1460static int check_apm_user(struct apm_user *as, const char *func)
1461{
1462	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1463		pr_err("%s passed bad filp\n", func);
1464		return 1;
1465	}
1466	return 0;
1467}
1468
1469static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1470{
1471	struct apm_user *as;
1472	int i;
1473	apm_event_t event;
1474
1475	as = fp->private_data;
1476	if (check_apm_user(as, "read"))
1477		return -EIO;
1478	if ((int)count < sizeof(apm_event_t))
1479		return -EINVAL;
1480	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1481		return -EAGAIN;
1482	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1483	i = count;
1484	while ((i >= sizeof(event)) && !queue_empty(as)) {
1485		event = get_queued_event(as);
1486		if (copy_to_user(buf, &event, sizeof(event))) {
1487			if (i < count)
1488				break;
1489			return -EFAULT;
1490		}
1491		switch (event) {
1492		case APM_SYS_SUSPEND:
1493		case APM_USER_SUSPEND:
1494			as->suspends_read++;
1495			break;
1496
1497		case APM_SYS_STANDBY:
1498		case APM_USER_STANDBY:
1499			as->standbys_read++;
1500			break;
1501		}
1502		buf += sizeof(event);
1503		i -= sizeof(event);
1504	}
1505	if (i < count)
1506		return count - i;
1507	if (signal_pending(current))
1508		return -ERESTARTSYS;
1509	return 0;
1510}
1511
1512static __poll_t do_poll(struct file *fp, poll_table *wait)
1513{
1514	struct apm_user *as;
1515
1516	as = fp->private_data;
1517	if (check_apm_user(as, "poll"))
1518		return 0;
1519	poll_wait(fp, &apm_waitqueue, wait);
1520	if (!queue_empty(as))
1521		return EPOLLIN | EPOLLRDNORM;
1522	return 0;
1523}
1524
1525static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1526{
1527	struct apm_user *as;
1528	int ret;
1529
1530	as = filp->private_data;
1531	if (check_apm_user(as, "ioctl"))
1532		return -EIO;
1533	if (!as->suser || !as->writer)
1534		return -EPERM;
1535	switch (cmd) {
1536	case APM_IOC_STANDBY:
1537		mutex_lock(&apm_mutex);
1538		if (as->standbys_read > 0) {
1539			as->standbys_read--;
1540			as->standbys_pending--;
1541			standbys_pending--;
1542		} else
1543			queue_event(APM_USER_STANDBY, as);
1544		if (standbys_pending <= 0)
1545			standby();
1546		mutex_unlock(&apm_mutex);
1547		break;
1548	case APM_IOC_SUSPEND:
1549		mutex_lock(&apm_mutex);
1550		if (as->suspends_read > 0) {
1551			as->suspends_read--;
1552			as->suspends_pending--;
1553			suspends_pending--;
1554		} else
1555			queue_event(APM_USER_SUSPEND, as);
1556		if (suspends_pending <= 0) {
1557			ret = suspend(1);
1558			mutex_unlock(&apm_mutex);
1559		} else {
1560			as->suspend_wait = 1;
1561			mutex_unlock(&apm_mutex);
1562			wait_event_interruptible(apm_suspend_waitqueue,
1563					as->suspend_wait == 0);
1564			ret = as->suspend_result;
1565		}
1566		return ret;
1567	default:
1568		return -ENOTTY;
1569	}
1570	return 0;
1571}
1572
1573static int do_release(struct inode *inode, struct file *filp)
1574{
1575	struct apm_user *as;
1576
1577	as = filp->private_data;
1578	if (check_apm_user(as, "release"))
1579		return 0;
1580	filp->private_data = NULL;
1581	if (as->standbys_pending > 0) {
1582		standbys_pending -= as->standbys_pending;
1583		if (standbys_pending <= 0)
1584			standby();
1585	}
1586	if (as->suspends_pending > 0) {
1587		suspends_pending -= as->suspends_pending;
1588		if (suspends_pending <= 0)
1589			(void) suspend(1);
1590	}
1591	spin_lock(&user_list_lock);
1592	if (user_list == as)
1593		user_list = as->next;
1594	else {
1595		struct apm_user *as1;
1596
1597		for (as1 = user_list;
1598		     (as1 != NULL) && (as1->next != as);
1599		     as1 = as1->next)
1600			;
1601		if (as1 == NULL)
1602			pr_err("filp not in user list\n");
1603		else
1604			as1->next = as->next;
1605	}
1606	spin_unlock(&user_list_lock);
1607	kfree(as);
1608	return 0;
1609}
1610
1611static int do_open(struct inode *inode, struct file *filp)
1612{
1613	struct apm_user *as;
1614
1615	as = kmalloc(sizeof(*as), GFP_KERNEL);
1616	if (as == NULL)
1617		return -ENOMEM;
1618
1619	as->magic = APM_BIOS_MAGIC;
1620	as->event_tail = as->event_head = 0;
1621	as->suspends_pending = as->standbys_pending = 0;
1622	as->suspends_read = as->standbys_read = 0;
1623	/*
1624	 * XXX - this is a tiny bit broken, when we consider BSD
1625	 * process accounting. If the device is opened by root, we
1626	 * instantly flag that we used superuser privs. Who knows,
1627	 * we might close the device immediately without doing a
1628	 * privileged operation -- cevans
1629	 */
1630	as->suser = capable(CAP_SYS_ADMIN);
1631	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1632	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1633	spin_lock(&user_list_lock);
1634	as->next = user_list;
1635	user_list = as;
1636	spin_unlock(&user_list_lock);
1637	filp->private_data = as;
1638	return 0;
1639}
1640
1641#ifdef CONFIG_PROC_FS
1642static int proc_apm_show(struct seq_file *m, void *v)
1643{
1644	unsigned short	bx;
1645	unsigned short	cx;
1646	unsigned short	dx;
1647	int		error;
1648	unsigned short  ac_line_status = 0xff;
1649	unsigned short  battery_status = 0xff;
1650	unsigned short  battery_flag   = 0xff;
1651	int		percentage     = -1;
1652	int             time_units     = -1;
1653	char            *units         = "?";
1654
1655	if ((num_online_cpus() == 1) &&
1656	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1657		ac_line_status = (bx >> 8) & 0xff;
1658		battery_status = bx & 0xff;
1659		if ((cx & 0xff) != 0xff)
1660			percentage = cx & 0xff;
1661
1662		if (apm_info.connection_version > 0x100) {
1663			battery_flag = (cx >> 8) & 0xff;
1664			if (dx != 0xffff) {
1665				units = (dx & 0x8000) ? "min" : "sec";
1666				time_units = dx & 0x7fff;
1667			}
1668		}
1669	}
1670	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1671	   from the Get Power Status (0x0a) call unless otherwise noted.
1672
1673	   0) Linux driver version (this will change if format changes)
1674	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1675	   2) APM flags from APM Installation Check (0x00):
1676	      bit 0: APM_16_BIT_SUPPORT
1677	      bit 1: APM_32_BIT_SUPPORT
1678	      bit 2: APM_IDLE_SLOWS_CLOCK
1679	      bit 3: APM_BIOS_DISABLED
1680	      bit 4: APM_BIOS_DISENGAGED
1681	   3) AC line status
1682	      0x00: Off-line
1683	      0x01: On-line
1684	      0x02: On backup power (BIOS >= 1.1 only)
1685	      0xff: Unknown
1686	   4) Battery status
1687	      0x00: High
1688	      0x01: Low
1689	      0x02: Critical
1690	      0x03: Charging
1691	      0x04: Selected battery not present (BIOS >= 1.2 only)
1692	      0xff: Unknown
1693	   5) Battery flag
1694	      bit 0: High
1695	      bit 1: Low
1696	      bit 2: Critical
1697	      bit 3: Charging
1698	      bit 7: No system battery
1699	      0xff: Unknown
1700	   6) Remaining battery life (percentage of charge):
1701	      0-100: valid
1702	      -1: Unknown
1703	   7) Remaining battery life (time units):
1704	      Number of remaining minutes or seconds
1705	      -1: Unknown
1706	   8) min = minutes; sec = seconds */
1707
1708	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1709		   driver_version,
1710		   (apm_info.bios.version >> 8) & 0xff,
1711		   apm_info.bios.version & 0xff,
1712		   apm_info.bios.flags,
1713		   ac_line_status,
1714		   battery_status,
1715		   battery_flag,
1716		   percentage,
1717		   time_units,
1718		   units);
1719	return 0;
1720}
1721#endif
 
 
 
 
 
 
 
 
 
 
 
 
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 const struct dmi_system_id apm_dmi_table[] __initconst = {
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 || 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		pr_notice("disabled on user request.\n");
2317		return -ENODEV;
2318	}
2319	if ((num_online_cpus() > 1) && !power_off && !smp) {
2320		pr_notice("disabled - APM is not SMP safe.\n");
2321		apm_info.disabled = 1;
2322		return -ENODEV;
2323	}
2324	if (!acpi_disabled) {
2325		pr_notice("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_rw(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_single("apm", 0, NULL, proc_apm_show);
2356
2357	kapmd_task = kthread_create(apm, NULL, "kapmd");
2358	if (IS_ERR(kapmd_task)) {
2359		pr_err("disabled - Unable to start kernel thread\n");
2360		err = PTR_ERR(kapmd_task);
2361		kapmd_task = NULL;
2362		remove_proc_entry("apm", NULL);
2363		return err;
2364	}
2365	wake_up_process(kapmd_task);
2366
2367	if (num_online_cpus() > 1 && !smp) {
2368		printk(KERN_NOTICE
2369		       "apm: disabled - APM is not SMP safe (power off active).\n");
2370		return 0;
2371	}
2372
2373	/*
2374	 * Note we don't actually care if the misc_device cannot be registered.
2375	 * this driver can do its job without it, even if userspace can't
2376	 * control it.  just log the error
2377	 */
2378	if (misc_register(&apm_device))
2379		printk(KERN_WARNING "apm: Could not register misc device.\n");
2380
2381	if (HZ != 100)
2382		idle_period = (idle_period * HZ) / 100;
2383	if (idle_threshold < 100) {
2384		cpuidle_poll_state_init(&apm_idle_driver);
2385		if (!cpuidle_register_driver(&apm_idle_driver))
2386			if (cpuidle_register_device(&apm_cpuidle_device))
2387				cpuidle_unregister_driver(&apm_idle_driver);
2388	}
2389
2390	return 0;
2391}
2392
2393static void __exit apm_exit(void)
2394{
2395	int error;
2396
2397	cpuidle_unregister_device(&apm_cpuidle_device);
2398	cpuidle_unregister_driver(&apm_idle_driver);
2399
2400	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2401	    && (apm_info.connection_version > 0x0100)) {
2402		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2403		if (error)
2404			apm_error("disengage power management", error);
2405	}
2406	misc_deregister(&apm_device);
2407	remove_proc_entry("apm", NULL);
2408	if (power_off)
2409		pm_power_off = NULL;
2410	if (kapmd_task) {
2411		kthread_stop(kapmd_task);
2412		kapmd_task = NULL;
2413	}
2414}
2415
2416module_init(apm_init);
2417module_exit(apm_exit);
2418
2419MODULE_AUTHOR("Stephen Rothwell");
2420MODULE_DESCRIPTION("Advanced Power Management");
2421MODULE_LICENSE("GPL");
2422module_param(debug, bool, 0644);
2423MODULE_PARM_DESC(debug, "Enable debug mode");
2424module_param(power_off, bool, 0444);
2425MODULE_PARM_DESC(power_off, "Enable power off");
2426module_param(bounce_interval, int, 0444);
2427MODULE_PARM_DESC(bounce_interval,
2428		"Set the number of ticks to ignore suspend bounces");
2429module_param(allow_ints, bool, 0444);
2430MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2431module_param(broken_psr, bool, 0444);
2432MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2433module_param(realmode_power_off, bool, 0444);
2434MODULE_PARM_DESC(realmode_power_off,
2435		"Switch to real mode before powering off");
2436module_param(idle_threshold, int, 0444);
2437MODULE_PARM_DESC(idle_threshold,
2438	"System idle percentage above which to make APM BIOS idle calls");
2439module_param(idle_period, int, 0444);
2440MODULE_PARM_DESC(idle_period,
2441	"Period (in sec/100) over which to calculate the idle percentage");
2442module_param(smp, bool, 0444);
2443MODULE_PARM_DESC(smp,
2444	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2445MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);