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