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v4.10.11
 
   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 <linux/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			.exit_latency = 250,	/* WAG */
 382			.target_residency = 500,	/* WAG */
 383			.enter = &apm_cpu_idle
 384		},
 385	},
 386	.state_count = 2,
 387};
 388
 389static struct cpuidle_device apm_cpuidle_device;
 390
 391/*
 392 * Local variables
 393 */
 394__visible struct {
 395	unsigned long	offset;
 396	unsigned short	segment;
 397} apm_bios_entry;
 398static int clock_slowed;
 399static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 400static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 401static int suspends_pending;
 402static int standbys_pending;
 403static int ignore_sys_suspend;
 404static int ignore_normal_resume;
 405static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 406
 407static bool debug __read_mostly;
 408static bool smp __read_mostly;
 409static int apm_disabled = -1;
 410#ifdef CONFIG_SMP
 411static bool power_off;
 412#else
 413static bool power_off = 1;
 414#endif
 415static bool realmode_power_off;
 416#ifdef CONFIG_APM_ALLOW_INTS
 417static bool allow_ints = 1;
 418#else
 419static bool allow_ints;
 420#endif
 421static bool broken_psr;
 422
 423static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 424static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 425static struct apm_user *user_list;
 426static DEFINE_SPINLOCK(user_list_lock);
 427static DEFINE_MUTEX(apm_mutex);
 428
 429/*
 430 * Set up a segment that references the real mode segment 0x40
 431 * that extends up to the end of page zero (that we have reserved).
 432 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 433 * even though they are called in protected mode.
 434 */
 435static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
 436			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 437
 438static const char driver_version[] = "1.16ac";	/* no spaces */
 439
 440static struct task_struct *kapmd_task;
 441
 442/*
 443 *	APM event names taken from the APM 1.2 specification. These are
 444 *	the message codes that the BIOS uses to tell us about events
 445 */
 446static const char * const apm_event_name[] = {
 447	"system standby",
 448	"system suspend",
 449	"normal resume",
 450	"critical resume",
 451	"low battery",
 452	"power status change",
 453	"update time",
 454	"critical suspend",
 455	"user standby",
 456	"user suspend",
 457	"system standby resume",
 458	"capabilities change"
 459};
 460#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 461
 462typedef struct lookup_t {
 463	int	key;
 464	char 	*msg;
 465} lookup_t;
 466
 467/*
 468 *	The BIOS returns a set of standard error codes in AX when the
 469 *	carry flag is set.
 470 */
 471
 472static const lookup_t error_table[] = {
 473/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 474	{ APM_DISABLED,		"Power management disabled" },
 475	{ APM_CONNECTED,	"Real mode interface already connected" },
 476	{ APM_NOT_CONNECTED,	"Interface not connected" },
 477	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 478/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 479	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 480	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 481	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 482	{ APM_BAD_PARAM,	"Parameter out of range" },
 483	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 484	{ APM_BAD_FUNCTION,     "Function not supported" },
 485	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 486	{ APM_BAD_STATE,	"Unable to enter requested state" },
 487/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 488	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 489	{ APM_NOT_PRESENT,	"No APM present" }
 490};
 491#define ERROR_COUNT	ARRAY_SIZE(error_table)
 492
 493/**
 494 *	apm_error	-	display an APM error
 495 *	@str: information string
 496 *	@err: APM BIOS return code
 497 *
 498 *	Write a meaningful log entry to the kernel log in the event of
 499 *	an APM error.  Note that this also handles (negative) kernel errors.
 500 */
 501
 502static void apm_error(char *str, int err)
 503{
 504	int i;
 505
 506	for (i = 0; i < ERROR_COUNT; i++)
 507		if (error_table[i].key == err)
 508			break;
 509	if (i < ERROR_COUNT)
 510		pr_notice("%s: %s\n", str, error_table[i].msg);
 511	else if (err < 0)
 512		pr_notice("%s: linux error code %i\n", str, err);
 513	else
 514		pr_notice("%s: unknown error code %#2.2x\n",
 515		       str, err);
 516}
 517
 518/*
 519 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 520 * apm_info.allow_ints, we are being really paranoid here!  Not only
 521 * are interrupts disabled, but all the segment registers (except SS)
 522 * are saved and zeroed this means that if the BIOS tries to reference
 523 * any data without explicitly loading the segment registers, the kernel
 524 * will fault immediately rather than have some unforeseen circumstances
 525 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 526 * this depends on CS referring to the same physical memory as DS so that
 527 * DS can be zeroed before the call. Unfortunately, we can't do anything
 528 * about the stack segment/pointer.  Also, we tell the compiler that
 529 * everything could change.
 530 *
 531 * Also, we KNOW that for the non error case of apm_bios_call, there
 532 * is no useful data returned in the low order 8 bits of eax.
 533 */
 534
 535static inline unsigned long __apm_irq_save(void)
 536{
 537	unsigned long flags;
 538	local_save_flags(flags);
 539	if (apm_info.allow_ints) {
 540		if (irqs_disabled_flags(flags))
 541			local_irq_enable();
 542	} else
 543		local_irq_disable();
 544
 545	return flags;
 546}
 547
 548#define apm_irq_save(flags) \
 549	do { flags = __apm_irq_save(); } while (0)
 550
 551static inline void apm_irq_restore(unsigned long flags)
 552{
 553	if (irqs_disabled_flags(flags))
 554		local_irq_disable();
 555	else if (irqs_disabled())
 556		local_irq_enable();
 557}
 558
 559#ifdef APM_ZERO_SEGS
 560#	define APM_DECL_SEGS \
 561		unsigned int saved_fs; unsigned int saved_gs;
 562#	define APM_DO_SAVE_SEGS \
 563		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 564#	define APM_DO_RESTORE_SEGS \
 565		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 566#else
 567#	define APM_DECL_SEGS
 568#	define APM_DO_SAVE_SEGS
 569#	define APM_DO_RESTORE_SEGS
 570#endif
 571
 572struct apm_bios_call {
 573	u32 func;
 574	/* In and out */
 575	u32 ebx;
 576	u32 ecx;
 577	/* Out only */
 578	u32 eax;
 579	u32 edx;
 580	u32 esi;
 581
 582	/* Error: -ENOMEM, or bits 8-15 of eax */
 583	int err;
 584};
 585
 586/**
 587 *	__apm_bios_call - Make an APM BIOS 32bit call
 588 *	@_call: pointer to struct apm_bios_call.
 589 *
 590 *	Make an APM call using the 32bit protected mode interface. The
 591 *	caller is responsible for knowing if APM BIOS is configured and
 592 *	enabled. This call can disable interrupts for a long period of
 593 *	time on some laptops.  The return value is in AH and the carry
 594 *	flag is loaded into AL.  If there is an error, then the error
 595 *	code is returned in AH (bits 8-15 of eax) and this function
 596 *	returns non-zero.
 597 *
 598 *	Note: this makes the call on the current CPU.
 599 */
 600static long __apm_bios_call(void *_call)
 601{
 602	APM_DECL_SEGS
 603	unsigned long		flags;
 604	int			cpu;
 605	struct desc_struct	save_desc_40;
 606	struct desc_struct	*gdt;
 607	struct apm_bios_call	*call = _call;
 
 608
 609	cpu = get_cpu();
 610	BUG_ON(cpu != 0);
 611	gdt = get_cpu_gdt_table(cpu);
 612	save_desc_40 = gdt[0x40 / 8];
 613	gdt[0x40 / 8] = bad_bios_desc;
 614
 615	apm_irq_save(flags);
 
 
 616	APM_DO_SAVE_SEGS;
 617	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 618			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 619			  &call->esi);
 620	APM_DO_RESTORE_SEGS;
 
 
 621	apm_irq_restore(flags);
 622	gdt[0x40 / 8] = save_desc_40;
 623	put_cpu();
 624
 625	return call->eax & 0xff;
 626}
 627
 628/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 629static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 630{
 631	int ret;
 632
 633	/* Don't bother with work_on_cpu in the common case, so we don't
 634	 * have to worry about OOM or overhead. */
 635	if (get_cpu() == 0) {
 636		ret = fn(call);
 637		put_cpu();
 638	} else {
 639		put_cpu();
 640		ret = work_on_cpu(0, fn, call);
 641	}
 642
 643	/* work_on_cpu can fail with -ENOMEM */
 644	if (ret < 0)
 645		call->err = ret;
 646	else
 647		call->err = (call->eax >> 8) & 0xff;
 648
 649	return ret;
 650}
 651
 652/**
 653 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 654 *	@call: the apm_bios_call registers.
 655 *
 656 *	If there is an error, it is returned in @call.err.
 657 */
 658static int apm_bios_call(struct apm_bios_call *call)
 659{
 660	return on_cpu0(__apm_bios_call, call);
 661}
 662
 663/**
 664 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 665 *	@_call: pointer to struct apm_bios_call.
 666 *
 667 *	Make a BIOS call that returns one value only, or just status.
 668 *	If there is an error, then the error code is returned in AH
 669 *	(bits 8-15 of eax) and this function returns non-zero (it can
 670 *	also return -ENOMEM). This is used for simpler BIOS operations.
 671 *	This call may hold interrupts off for a long time on some laptops.
 672 *
 673 *	Note: this makes the call on the current CPU.
 674 */
 675static long __apm_bios_call_simple(void *_call)
 676{
 677	u8			error;
 678	APM_DECL_SEGS
 679	unsigned long		flags;
 680	int			cpu;
 681	struct desc_struct	save_desc_40;
 682	struct desc_struct	*gdt;
 683	struct apm_bios_call	*call = _call;
 
 684
 685	cpu = get_cpu();
 686	BUG_ON(cpu != 0);
 687	gdt = get_cpu_gdt_table(cpu);
 688	save_desc_40 = gdt[0x40 / 8];
 689	gdt[0x40 / 8] = bad_bios_desc;
 690
 691	apm_irq_save(flags);
 
 
 692	APM_DO_SAVE_SEGS;
 693	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 694					 &call->eax);
 695	APM_DO_RESTORE_SEGS;
 
 
 696	apm_irq_restore(flags);
 697	gdt[0x40 / 8] = save_desc_40;
 698	put_cpu();
 699	return error;
 700}
 701
 702/**
 703 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 704 *	@func: APM function to invoke
 705 *	@ebx_in: EBX register value for BIOS call
 706 *	@ecx_in: ECX register value for BIOS call
 707 *	@eax: EAX register on return from the BIOS call
 708 *	@err: bits
 709 *
 710 *	Make a BIOS call that returns one value only, or just status.
 711 *	If there is an error, then the error code is returned in @err
 712 *	and this function returns non-zero. This is used for simpler
 713 *	BIOS operations.  This call may hold interrupts off for a long
 714 *	time on some laptops.
 715 */
 716static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 717				int *err)
 718{
 719	struct apm_bios_call call;
 720	int ret;
 721
 722	call.func = func;
 723	call.ebx = ebx_in;
 724	call.ecx = ecx_in;
 725
 726	ret = on_cpu0(__apm_bios_call_simple, &call);
 727	*eax = call.eax;
 728	*err = call.err;
 729	return ret;
 730}
 731
 732/**
 733 *	apm_driver_version	-	APM driver version
 734 *	@val:	loaded with the APM version on return
 735 *
 736 *	Retrieve the APM version supported by the BIOS. This is only
 737 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 738 *	probably present.
 739 *
 740 *	On entry val should point to a value indicating the APM driver
 741 *	version with the high byte being the major and the low byte the
 742 *	minor number both in BCD
 743 *
 744 *	On return it will hold the BIOS revision supported in the
 745 *	same format.
 746 */
 747
 748static int apm_driver_version(u_short *val)
 749{
 750	u32 eax;
 751	int err;
 752
 753	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 754		return err;
 755	*val = eax;
 756	return APM_SUCCESS;
 757}
 758
 759/**
 760 *	apm_get_event	-	get an APM event from the BIOS
 761 *	@event: pointer to the event
 762 *	@info: point to the event information
 763 *
 764 *	The APM BIOS provides a polled information for event
 765 *	reporting. The BIOS expects to be polled at least every second
 766 *	when events are pending. When a message is found the caller should
 767 *	poll until no more messages are present.  However, this causes
 768 *	problems on some laptops where a suspend event notification is
 769 *	not cleared until it is acknowledged.
 770 *
 771 *	Additional information is returned in the info pointer, providing
 772 *	that APM 1.2 is in use. If no messges are pending the value 0x80
 773 *	is returned (No power management events pending).
 774 */
 775static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 776{
 777	struct apm_bios_call call;
 778
 779	call.func = APM_FUNC_GET_EVENT;
 780	call.ebx = call.ecx = 0;
 781
 782	if (apm_bios_call(&call))
 783		return call.err;
 784
 785	*event = call.ebx;
 786	if (apm_info.connection_version < 0x0102)
 787		*info = ~0; /* indicate info not valid */
 788	else
 789		*info = call.ecx;
 790	return APM_SUCCESS;
 791}
 792
 793/**
 794 *	set_power_state	-	set the power management state
 795 *	@what: which items to transition
 796 *	@state: state to transition to
 797 *
 798 *	Request an APM change of state for one or more system devices. The
 799 *	processor state must be transitioned last of all. what holds the
 800 *	class of device in the upper byte and the device number (0xFF for
 801 *	all) for the object to be transitioned.
 802 *
 803 *	The state holds the state to transition to, which may in fact
 804 *	be an acceptance of a BIOS requested state change.
 805 */
 806
 807static int set_power_state(u_short what, u_short state)
 808{
 809	u32 eax;
 810	int err;
 811
 812	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 813		return err;
 814	return APM_SUCCESS;
 815}
 816
 817/**
 818 *	set_system_power_state - set system wide power state
 819 *	@state: which state to enter
 820 *
 821 *	Transition the entire system into a new APM power state.
 822 */
 823
 824static int set_system_power_state(u_short state)
 825{
 826	return set_power_state(APM_DEVICE_ALL, state);
 827}
 828
 829/**
 830 *	apm_do_idle	-	perform power saving
 831 *
 832 *	This function notifies the BIOS that the processor is (in the view
 833 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 834 *	to handle the idle request. On a success the function returns 1
 835 *	if the BIOS did clock slowing or 0 otherwise.
 836 */
 837
 838static int apm_do_idle(void)
 839{
 840	u32 eax;
 841	u8 ret = 0;
 842	int idled = 0;
 843	int err = 0;
 844
 845	if (!need_resched()) {
 846		idled = 1;
 847		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 848	}
 849
 850	if (!idled)
 851		return 0;
 852
 853	if (ret) {
 854		static unsigned long t;
 855
 856		/* This always fails on some SMP boards running UP kernels.
 857		 * Only report the failure the first 5 times.
 858		 */
 859		if (++t < 5) {
 860			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 861			t = jiffies;
 862		}
 863		return -1;
 864	}
 865	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 866	return clock_slowed;
 867}
 868
 869/**
 870 *	apm_do_busy	-	inform the BIOS the CPU is busy
 871 *
 872 *	Request that the BIOS brings the CPU back to full performance.
 873 */
 874
 875static void apm_do_busy(void)
 876{
 877	u32 dummy;
 878	int err;
 879
 880	if (clock_slowed || ALWAYS_CALL_BUSY) {
 881		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 882		clock_slowed = 0;
 883	}
 884}
 885
 886/*
 887 * If no process has really been interested in
 888 * the CPU for some time, we want to call BIOS
 889 * power management - we probably want
 890 * to conserve power.
 891 */
 892#define IDLE_CALC_LIMIT	(HZ * 100)
 893#define IDLE_LEAKY_MAX	16
 894
 895/**
 896 * apm_cpu_idle		-	cpu idling for APM capable Linux
 897 *
 898 * This is the idling function the kernel executes when APM is available. It
 899 * tries to do BIOS powermanagement based on the average system idle time.
 900 * Furthermore it calls the system default idle routine.
 901 */
 902
 903static int apm_cpu_idle(struct cpuidle_device *dev,
 904	struct cpuidle_driver *drv, int index)
 905{
 906	static int use_apm_idle; /* = 0 */
 907	static unsigned int last_jiffies; /* = 0 */
 908	static unsigned int last_stime; /* = 0 */
 909	cputime_t stime, utime;
 910
 911	int apm_idle_done = 0;
 912	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 913	unsigned int bucket;
 914
 915recalc:
 916	task_cputime(current, &utime, &stime);
 917	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 918		use_apm_idle = 0;
 919	} else if (jiffies_since_last_check > idle_period) {
 920		unsigned int idle_percentage;
 921
 922		idle_percentage = cputime_to_jiffies(stime - last_stime);
 923		idle_percentage *= 100;
 924		idle_percentage /= jiffies_since_last_check;
 925		use_apm_idle = (idle_percentage > idle_threshold);
 926		if (apm_info.forbid_idle)
 927			use_apm_idle = 0;
 928	}
 929
 930	last_jiffies = jiffies;
 931	last_stime = stime;
 932
 933	bucket = IDLE_LEAKY_MAX;
 934
 935	while (!need_resched()) {
 936		if (use_apm_idle) {
 937			unsigned int t;
 938
 939			t = jiffies;
 940			switch (apm_do_idle()) {
 941			case 0:
 942				apm_idle_done = 1;
 943				if (t != jiffies) {
 944					if (bucket) {
 945						bucket = IDLE_LEAKY_MAX;
 946						continue;
 947					}
 948				} else if (bucket) {
 949					bucket--;
 950					continue;
 951				}
 952				break;
 953			case 1:
 954				apm_idle_done = 1;
 955				break;
 956			default: /* BIOS refused */
 957				break;
 958			}
 959		}
 960		default_idle();
 961		local_irq_disable();
 962		jiffies_since_last_check = jiffies - last_jiffies;
 963		if (jiffies_since_last_check > idle_period)
 964			goto recalc;
 965	}
 966
 967	if (apm_idle_done)
 968		apm_do_busy();
 969
 970	return index;
 971}
 972
 973/**
 974 *	apm_power_off	-	ask the BIOS to power off
 975 *
 976 *	Handle the power off sequence. This is the one piece of code we
 977 *	will execute even on SMP machines. In order to deal with BIOS
 978 *	bugs we support real mode APM BIOS power off calls. We also make
 979 *	the SMP call on CPU0 as some systems will only honour this call
 980 *	on their first cpu.
 981 */
 982
 983static void apm_power_off(void)
 984{
 985	/* Some bioses don't like being called from CPU != 0 */
 986	if (apm_info.realmode_power_off) {
 987		set_cpus_allowed_ptr(current, cpumask_of(0));
 988		machine_real_restart(MRR_APM);
 989	} else {
 990		(void)set_system_power_state(APM_STATE_OFF);
 991	}
 992}
 993
 994#ifdef CONFIG_APM_DO_ENABLE
 995
 996/**
 997 *	apm_enable_power_management - enable BIOS APM power management
 998 *	@enable: enable yes/no
 999 *
1000 *	Enable or disable the APM BIOS power services.
1001 */
1002
1003static int apm_enable_power_management(int enable)
1004{
1005	u32 eax;
1006	int err;
1007
1008	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1009		return APM_NOT_ENGAGED;
1010	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1011				 enable, &eax, &err))
1012		return err;
1013	if (enable)
1014		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1015	else
1016		apm_info.bios.flags |= APM_BIOS_DISABLED;
1017	return APM_SUCCESS;
1018}
1019#endif
1020
1021/**
1022 *	apm_get_power_status	-	get current power state
1023 *	@status: returned status
1024 *	@bat: battery info
1025 *	@life: estimated life
1026 *
1027 *	Obtain the current power status from the APM BIOS. We return a
1028 *	status which gives the rough battery status, and current power
1029 *	source. The bat value returned give an estimate as a percentage
1030 *	of life and a status value for the battery. The estimated life
1031 *	if reported is a lifetime in secodnds/minutes at current powwer
1032 *	consumption.
1033 */
1034
1035static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1036{
1037	struct apm_bios_call call;
1038
1039	call.func = APM_FUNC_GET_STATUS;
1040	call.ebx = APM_DEVICE_ALL;
1041	call.ecx = 0;
1042
1043	if (apm_info.get_power_status_broken)
1044		return APM_32_UNSUPPORTED;
1045	if (apm_bios_call(&call)) {
1046		if (!call.err)
1047			return APM_NO_ERROR;
1048		return call.err;
1049	}
1050	*status = call.ebx;
1051	*bat = call.ecx;
1052	if (apm_info.get_power_status_swabinminutes) {
1053		*life = swab16((u16)call.edx);
1054		*life |= 0x8000;
1055	} else
1056		*life = call.edx;
1057	return APM_SUCCESS;
1058}
1059
1060#if 0
1061static int apm_get_battery_status(u_short which, u_short *status,
1062				  u_short *bat, u_short *life, u_short *nbat)
1063{
1064	u32 eax;
1065	u32 ebx;
1066	u32 ecx;
1067	u32 edx;
1068	u32 esi;
1069
1070	if (apm_info.connection_version < 0x0102) {
1071		/* pretend we only have one battery. */
1072		if (which != 1)
1073			return APM_BAD_DEVICE;
1074		*nbat = 1;
1075		return apm_get_power_status(status, bat, life);
1076	}
1077
1078	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1079			  &ebx, &ecx, &edx, &esi))
1080		return (eax >> 8) & 0xff;
1081	*status = ebx;
1082	*bat = ecx;
1083	*life = edx;
1084	*nbat = esi;
1085	return APM_SUCCESS;
1086}
1087#endif
1088
1089/**
1090 *	apm_engage_power_management	-	enable PM on a device
1091 *	@device: identity of device
1092 *	@enable: on/off
1093 *
1094 *	Activate or deactivate power management on either a specific device
1095 *	or the entire system (%APM_DEVICE_ALL).
1096 */
1097
1098static int apm_engage_power_management(u_short device, int enable)
1099{
1100	u32 eax;
1101	int err;
1102
1103	if ((enable == 0) && (device == APM_DEVICE_ALL)
1104	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1105		return APM_DISABLED;
1106	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1107				 &eax, &err))
1108		return err;
1109	if (device == APM_DEVICE_ALL) {
1110		if (enable)
1111			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1112		else
1113			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1114	}
1115	return APM_SUCCESS;
1116}
1117
1118#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1119
1120/**
1121 *	apm_console_blank	-	blank the display
1122 *	@blank: on/off
1123 *
1124 *	Attempt to blank the console, firstly by blanking just video device
1125 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1126 *	all video devices. Typically the BIOS will do laptop backlight and
1127 *	monitor powerdown for us.
1128 */
1129
1130static int apm_console_blank(int blank)
1131{
1132	int error = APM_NOT_ENGAGED; /* silence gcc */
1133	int i;
1134	u_short state;
1135	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1136
1137	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1138
1139	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1140		error = set_power_state(dev[i], state);
1141
1142		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1143			return 1;
1144
1145		if (error == APM_NOT_ENGAGED)
1146			break;
1147	}
1148
1149	if (error == APM_NOT_ENGAGED) {
1150		static int tried;
1151		int eng_error;
1152		if (tried++ == 0) {
1153			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1154			if (eng_error) {
1155				apm_error("set display", error);
1156				apm_error("engage interface", eng_error);
1157				return 0;
1158			} else
1159				return apm_console_blank(blank);
1160		}
1161	}
1162	apm_error("set display", error);
1163	return 0;
1164}
1165#endif
1166
1167static int queue_empty(struct apm_user *as)
1168{
1169	return as->event_head == as->event_tail;
1170}
1171
1172static apm_event_t get_queued_event(struct apm_user *as)
1173{
1174	if (++as->event_tail >= APM_MAX_EVENTS)
1175		as->event_tail = 0;
1176	return as->events[as->event_tail];
1177}
1178
1179static void queue_event(apm_event_t event, struct apm_user *sender)
1180{
1181	struct apm_user *as;
1182
1183	spin_lock(&user_list_lock);
1184	if (user_list == NULL)
1185		goto out;
1186	for (as = user_list; as != NULL; as = as->next) {
1187		if ((as == sender) || (!as->reader))
1188			continue;
1189		if (++as->event_head >= APM_MAX_EVENTS)
1190			as->event_head = 0;
1191
1192		if (as->event_head == as->event_tail) {
1193			static int notified;
1194
1195			if (notified++ == 0)
1196				pr_err("an event queue overflowed\n");
1197			if (++as->event_tail >= APM_MAX_EVENTS)
1198				as->event_tail = 0;
1199		}
1200		as->events[as->event_head] = event;
1201		if (!as->suser || !as->writer)
1202			continue;
1203		switch (event) {
1204		case APM_SYS_SUSPEND:
1205		case APM_USER_SUSPEND:
1206			as->suspends_pending++;
1207			suspends_pending++;
1208			break;
1209
1210		case APM_SYS_STANDBY:
1211		case APM_USER_STANDBY:
1212			as->standbys_pending++;
1213			standbys_pending++;
1214			break;
1215		}
1216	}
1217	wake_up_interruptible(&apm_waitqueue);
1218out:
1219	spin_unlock(&user_list_lock);
1220}
1221
1222static void reinit_timer(void)
1223{
1224#ifdef INIT_TIMER_AFTER_SUSPEND
1225	unsigned long flags;
1226
1227	raw_spin_lock_irqsave(&i8253_lock, flags);
1228	/* set the clock to HZ */
1229	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1230	udelay(10);
1231	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1232	udelay(10);
1233	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1234	udelay(10);
1235	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1236#endif
1237}
1238
1239static int suspend(int vetoable)
1240{
1241	int err;
1242	struct apm_user	*as;
1243
1244	dpm_suspend_start(PMSG_SUSPEND);
1245	dpm_suspend_end(PMSG_SUSPEND);
1246
1247	local_irq_disable();
1248	syscore_suspend();
1249
1250	local_irq_enable();
1251
1252	save_processor_state();
1253	err = set_system_power_state(APM_STATE_SUSPEND);
1254	ignore_normal_resume = 1;
1255	restore_processor_state();
1256
1257	local_irq_disable();
1258	reinit_timer();
1259
1260	if (err == APM_NO_ERROR)
1261		err = APM_SUCCESS;
1262	if (err != APM_SUCCESS)
1263		apm_error("suspend", err);
1264	err = (err == APM_SUCCESS) ? 0 : -EIO;
1265
1266	syscore_resume();
1267	local_irq_enable();
1268
1269	dpm_resume_start(PMSG_RESUME);
1270	dpm_resume_end(PMSG_RESUME);
1271
1272	queue_event(APM_NORMAL_RESUME, NULL);
1273	spin_lock(&user_list_lock);
1274	for (as = user_list; as != NULL; as = as->next) {
1275		as->suspend_wait = 0;
1276		as->suspend_result = err;
1277	}
1278	spin_unlock(&user_list_lock);
1279	wake_up_interruptible(&apm_suspend_waitqueue);
1280	return err;
1281}
1282
1283static void standby(void)
1284{
1285	int err;
1286
1287	dpm_suspend_end(PMSG_SUSPEND);
1288
1289	local_irq_disable();
1290	syscore_suspend();
1291	local_irq_enable();
1292
1293	err = set_system_power_state(APM_STATE_STANDBY);
1294	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1295		apm_error("standby", err);
1296
1297	local_irq_disable();
1298	syscore_resume();
1299	local_irq_enable();
1300
1301	dpm_resume_start(PMSG_RESUME);
1302}
1303
1304static apm_event_t get_event(void)
1305{
1306	int error;
1307	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1308	apm_eventinfo_t	info;
1309
1310	static int notified;
1311
1312	/* we don't use the eventinfo */
1313	error = apm_get_event(&event, &info);
1314	if (error == APM_SUCCESS)
1315		return event;
1316
1317	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1318		apm_error("get_event", error);
1319
1320	return 0;
1321}
1322
1323static void check_events(void)
1324{
1325	apm_event_t event;
1326	static unsigned long last_resume;
1327	static int ignore_bounce;
1328
1329	while ((event = get_event()) != 0) {
1330		if (debug) {
1331			if (event <= NR_APM_EVENT_NAME)
1332				printk(KERN_DEBUG "apm: received %s notify\n",
1333				       apm_event_name[event - 1]);
1334			else
1335				printk(KERN_DEBUG "apm: received unknown "
1336				       "event 0x%02x\n", event);
1337		}
1338		if (ignore_bounce
1339		    && (time_after(jiffies, last_resume + bounce_interval)))
1340			ignore_bounce = 0;
1341
1342		switch (event) {
1343		case APM_SYS_STANDBY:
1344		case APM_USER_STANDBY:
1345			queue_event(event, NULL);
1346			if (standbys_pending <= 0)
1347				standby();
1348			break;
1349
1350		case APM_USER_SUSPEND:
1351#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1352			if (apm_info.connection_version > 0x100)
1353				set_system_power_state(APM_STATE_REJECT);
1354			break;
1355#endif
1356		case APM_SYS_SUSPEND:
1357			if (ignore_bounce) {
1358				if (apm_info.connection_version > 0x100)
1359					set_system_power_state(APM_STATE_REJECT);
1360				break;
1361			}
1362			/*
1363			 * If we are already processing a SUSPEND,
1364			 * then further SUSPEND events from the BIOS
1365			 * will be ignored.  We also return here to
1366			 * cope with the fact that the Thinkpads keep
1367			 * sending a SUSPEND event until something else
1368			 * happens!
1369			 */
1370			if (ignore_sys_suspend)
1371				return;
1372			ignore_sys_suspend = 1;
1373			queue_event(event, NULL);
1374			if (suspends_pending <= 0)
1375				(void) suspend(1);
1376			break;
1377
1378		case APM_NORMAL_RESUME:
1379		case APM_CRITICAL_RESUME:
1380		case APM_STANDBY_RESUME:
1381			ignore_sys_suspend = 0;
1382			last_resume = jiffies;
1383			ignore_bounce = 1;
1384			if ((event != APM_NORMAL_RESUME)
1385			    || (ignore_normal_resume == 0)) {
1386				dpm_resume_end(PMSG_RESUME);
1387				queue_event(event, NULL);
1388			}
1389			ignore_normal_resume = 0;
1390			break;
1391
1392		case APM_CAPABILITY_CHANGE:
1393		case APM_LOW_BATTERY:
1394		case APM_POWER_STATUS_CHANGE:
1395			queue_event(event, NULL);
1396			/* If needed, notify drivers here */
1397			break;
1398
1399		case APM_UPDATE_TIME:
1400			break;
1401
1402		case APM_CRITICAL_SUSPEND:
1403			/*
1404			 * We are not allowed to reject a critical suspend.
1405			 */
1406			(void)suspend(0);
1407			break;
1408		}
1409	}
1410}
1411
1412static void apm_event_handler(void)
1413{
1414	static int pending_count = 4;
1415	int err;
1416
1417	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1418		if ((apm_info.connection_version > 0x100) &&
1419		    (pending_count-- <= 0)) {
1420			pending_count = 4;
1421			if (debug)
1422				printk(KERN_DEBUG "apm: setting state busy\n");
1423			err = set_system_power_state(APM_STATE_BUSY);
1424			if (err)
1425				apm_error("busy", err);
1426		}
1427	} else
1428		pending_count = 4;
1429	check_events();
1430}
1431
1432/*
1433 * This is the APM thread main loop.
1434 */
1435
1436static void apm_mainloop(void)
1437{
1438	DECLARE_WAITQUEUE(wait, current);
1439
1440	add_wait_queue(&apm_waitqueue, &wait);
1441	set_current_state(TASK_INTERRUPTIBLE);
1442	for (;;) {
1443		schedule_timeout(APM_CHECK_TIMEOUT);
1444		if (kthread_should_stop())
1445			break;
1446		/*
1447		 * Ok, check all events, check for idle (and mark us sleeping
1448		 * so as not to count towards the load average)..
1449		 */
1450		set_current_state(TASK_INTERRUPTIBLE);
1451		apm_event_handler();
1452	}
1453	remove_wait_queue(&apm_waitqueue, &wait);
1454}
1455
1456static int check_apm_user(struct apm_user *as, const char *func)
1457{
1458	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1459		pr_err("%s passed bad filp\n", func);
1460		return 1;
1461	}
1462	return 0;
1463}
1464
1465static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1466{
1467	struct apm_user *as;
1468	int i;
1469	apm_event_t event;
1470
1471	as = fp->private_data;
1472	if (check_apm_user(as, "read"))
1473		return -EIO;
1474	if ((int)count < sizeof(apm_event_t))
1475		return -EINVAL;
1476	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1477		return -EAGAIN;
1478	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1479	i = count;
1480	while ((i >= sizeof(event)) && !queue_empty(as)) {
1481		event = get_queued_event(as);
1482		if (copy_to_user(buf, &event, sizeof(event))) {
1483			if (i < count)
1484				break;
1485			return -EFAULT;
1486		}
1487		switch (event) {
1488		case APM_SYS_SUSPEND:
1489		case APM_USER_SUSPEND:
1490			as->suspends_read++;
1491			break;
1492
1493		case APM_SYS_STANDBY:
1494		case APM_USER_STANDBY:
1495			as->standbys_read++;
1496			break;
1497		}
1498		buf += sizeof(event);
1499		i -= sizeof(event);
1500	}
1501	if (i < count)
1502		return count - i;
1503	if (signal_pending(current))
1504		return -ERESTARTSYS;
1505	return 0;
1506}
1507
1508static unsigned int do_poll(struct file *fp, poll_table *wait)
1509{
1510	struct apm_user *as;
1511
1512	as = fp->private_data;
1513	if (check_apm_user(as, "poll"))
1514		return 0;
1515	poll_wait(fp, &apm_waitqueue, wait);
1516	if (!queue_empty(as))
1517		return POLLIN | POLLRDNORM;
1518	return 0;
1519}
1520
1521static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1522{
1523	struct apm_user *as;
1524	int ret;
1525
1526	as = filp->private_data;
1527	if (check_apm_user(as, "ioctl"))
1528		return -EIO;
1529	if (!as->suser || !as->writer)
1530		return -EPERM;
1531	switch (cmd) {
1532	case APM_IOC_STANDBY:
1533		mutex_lock(&apm_mutex);
1534		if (as->standbys_read > 0) {
1535			as->standbys_read--;
1536			as->standbys_pending--;
1537			standbys_pending--;
1538		} else
1539			queue_event(APM_USER_STANDBY, as);
1540		if (standbys_pending <= 0)
1541			standby();
1542		mutex_unlock(&apm_mutex);
1543		break;
1544	case APM_IOC_SUSPEND:
1545		mutex_lock(&apm_mutex);
1546		if (as->suspends_read > 0) {
1547			as->suspends_read--;
1548			as->suspends_pending--;
1549			suspends_pending--;
1550		} else
1551			queue_event(APM_USER_SUSPEND, as);
1552		if (suspends_pending <= 0) {
1553			ret = suspend(1);
1554			mutex_unlock(&apm_mutex);
1555		} else {
1556			as->suspend_wait = 1;
1557			mutex_unlock(&apm_mutex);
1558			wait_event_interruptible(apm_suspend_waitqueue,
1559					as->suspend_wait == 0);
1560			ret = as->suspend_result;
1561		}
1562		return ret;
1563	default:
1564		return -ENOTTY;
1565	}
1566	return 0;
1567}
1568
1569static int do_release(struct inode *inode, struct file *filp)
1570{
1571	struct apm_user *as;
1572
1573	as = filp->private_data;
1574	if (check_apm_user(as, "release"))
1575		return 0;
1576	filp->private_data = NULL;
1577	if (as->standbys_pending > 0) {
1578		standbys_pending -= as->standbys_pending;
1579		if (standbys_pending <= 0)
1580			standby();
1581	}
1582	if (as->suspends_pending > 0) {
1583		suspends_pending -= as->suspends_pending;
1584		if (suspends_pending <= 0)
1585			(void) suspend(1);
1586	}
1587	spin_lock(&user_list_lock);
1588	if (user_list == as)
1589		user_list = as->next;
1590	else {
1591		struct apm_user *as1;
1592
1593		for (as1 = user_list;
1594		     (as1 != NULL) && (as1->next != as);
1595		     as1 = as1->next)
1596			;
1597		if (as1 == NULL)
1598			pr_err("filp not in user list\n");
1599		else
1600			as1->next = as->next;
1601	}
1602	spin_unlock(&user_list_lock);
1603	kfree(as);
1604	return 0;
1605}
1606
1607static int do_open(struct inode *inode, struct file *filp)
1608{
1609	struct apm_user *as;
1610
1611	as = kmalloc(sizeof(*as), GFP_KERNEL);
1612	if (as == NULL)
1613		return -ENOMEM;
1614
1615	as->magic = APM_BIOS_MAGIC;
1616	as->event_tail = as->event_head = 0;
1617	as->suspends_pending = as->standbys_pending = 0;
1618	as->suspends_read = as->standbys_read = 0;
1619	/*
1620	 * XXX - this is a tiny bit broken, when we consider BSD
1621	 * process accounting. If the device is opened by root, we
1622	 * instantly flag that we used superuser privs. Who knows,
1623	 * we might close the device immediately without doing a
1624	 * privileged operation -- cevans
1625	 */
1626	as->suser = capable(CAP_SYS_ADMIN);
1627	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1628	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1629	spin_lock(&user_list_lock);
1630	as->next = user_list;
1631	user_list = as;
1632	spin_unlock(&user_list_lock);
1633	filp->private_data = as;
1634	return 0;
1635}
1636
 
1637static int proc_apm_show(struct seq_file *m, void *v)
1638{
1639	unsigned short	bx;
1640	unsigned short	cx;
1641	unsigned short	dx;
1642	int		error;
1643	unsigned short  ac_line_status = 0xff;
1644	unsigned short  battery_status = 0xff;
1645	unsigned short  battery_flag   = 0xff;
1646	int		percentage     = -1;
1647	int             time_units     = -1;
1648	char            *units         = "?";
1649
1650	if ((num_online_cpus() == 1) &&
1651	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1652		ac_line_status = (bx >> 8) & 0xff;
1653		battery_status = bx & 0xff;
1654		if ((cx & 0xff) != 0xff)
1655			percentage = cx & 0xff;
1656
1657		if (apm_info.connection_version > 0x100) {
1658			battery_flag = (cx >> 8) & 0xff;
1659			if (dx != 0xffff) {
1660				units = (dx & 0x8000) ? "min" : "sec";
1661				time_units = dx & 0x7fff;
1662			}
1663		}
1664	}
1665	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1666	   from the Get Power Status (0x0a) call unless otherwise noted.
1667
1668	   0) Linux driver version (this will change if format changes)
1669	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1670	   2) APM flags from APM Installation Check (0x00):
1671	      bit 0: APM_16_BIT_SUPPORT
1672	      bit 1: APM_32_BIT_SUPPORT
1673	      bit 2: APM_IDLE_SLOWS_CLOCK
1674	      bit 3: APM_BIOS_DISABLED
1675	      bit 4: APM_BIOS_DISENGAGED
1676	   3) AC line status
1677	      0x00: Off-line
1678	      0x01: On-line
1679	      0x02: On backup power (BIOS >= 1.1 only)
1680	      0xff: Unknown
1681	   4) Battery status
1682	      0x00: High
1683	      0x01: Low
1684	      0x02: Critical
1685	      0x03: Charging
1686	      0x04: Selected battery not present (BIOS >= 1.2 only)
1687	      0xff: Unknown
1688	   5) Battery flag
1689	      bit 0: High
1690	      bit 1: Low
1691	      bit 2: Critical
1692	      bit 3: Charging
1693	      bit 7: No system battery
1694	      0xff: Unknown
1695	   6) Remaining battery life (percentage of charge):
1696	      0-100: valid
1697	      -1: Unknown
1698	   7) Remaining battery life (time units):
1699	      Number of remaining minutes or seconds
1700	      -1: Unknown
1701	   8) min = minutes; sec = seconds */
1702
1703	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1704		   driver_version,
1705		   (apm_info.bios.version >> 8) & 0xff,
1706		   apm_info.bios.version & 0xff,
1707		   apm_info.bios.flags,
1708		   ac_line_status,
1709		   battery_status,
1710		   battery_flag,
1711		   percentage,
1712		   time_units,
1713		   units);
1714	return 0;
1715}
1716
1717static int proc_apm_open(struct inode *inode, struct file *file)
1718{
1719	return single_open(file, proc_apm_show, NULL);
1720}
1721
1722static const struct file_operations apm_file_ops = {
1723	.owner		= THIS_MODULE,
1724	.open		= proc_apm_open,
1725	.read		= seq_read,
1726	.llseek		= seq_lseek,
1727	.release	= single_release,
1728};
1729
1730static int apm(void *unused)
1731{
1732	unsigned short	bx;
1733	unsigned short	cx;
1734	unsigned short	dx;
1735	int		error;
1736	char 		*power_stat;
1737	char 		*bat_stat;
1738
1739	/* 2002/08/01 - WT
1740	 * This is to avoid random crashes at boot time during initialization
1741	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1742	 * Some bioses don't like being called from CPU != 0.
1743	 * Method suggested by Ingo Molnar.
1744	 */
1745	set_cpus_allowed_ptr(current, cpumask_of(0));
1746	BUG_ON(smp_processor_id() != 0);
1747
1748	if (apm_info.connection_version == 0) {
1749		apm_info.connection_version = apm_info.bios.version;
1750		if (apm_info.connection_version > 0x100) {
1751			/*
1752			 * We only support BIOSs up to version 1.2
1753			 */
1754			if (apm_info.connection_version > 0x0102)
1755				apm_info.connection_version = 0x0102;
1756			error = apm_driver_version(&apm_info.connection_version);
1757			if (error != APM_SUCCESS) {
1758				apm_error("driver version", error);
1759				/* Fall back to an APM 1.0 connection. */
1760				apm_info.connection_version = 0x100;
1761			}
1762		}
1763	}
1764
1765	if (debug)
1766		printk(KERN_INFO "apm: Connection version %d.%d\n",
1767			(apm_info.connection_version >> 8) & 0xff,
1768			apm_info.connection_version & 0xff);
1769
1770#ifdef CONFIG_APM_DO_ENABLE
1771	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1772		/*
1773		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1774		 * is booted with PM disabled but not in the docking station.
1775		 * Unfortunate ...
1776		 */
1777		error = apm_enable_power_management(1);
1778		if (error) {
1779			apm_error("enable power management", error);
1780			return -1;
1781		}
1782	}
1783#endif
1784
1785	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1786	    && (apm_info.connection_version > 0x0100)) {
1787		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1788		if (error) {
1789			apm_error("engage power management", error);
1790			return -1;
1791		}
1792	}
1793
1794	if (debug && (num_online_cpus() == 1 || smp)) {
1795		error = apm_get_power_status(&bx, &cx, &dx);
1796		if (error)
1797			printk(KERN_INFO "apm: power status not available\n");
1798		else {
1799			switch ((bx >> 8) & 0xff) {
1800			case 0:
1801				power_stat = "off line";
1802				break;
1803			case 1:
1804				power_stat = "on line";
1805				break;
1806			case 2:
1807				power_stat = "on backup power";
1808				break;
1809			default:
1810				power_stat = "unknown";
1811				break;
1812			}
1813			switch (bx & 0xff) {
1814			case 0:
1815				bat_stat = "high";
1816				break;
1817			case 1:
1818				bat_stat = "low";
1819				break;
1820			case 2:
1821				bat_stat = "critical";
1822				break;
1823			case 3:
1824				bat_stat = "charging";
1825				break;
1826			default:
1827				bat_stat = "unknown";
1828				break;
1829			}
1830			printk(KERN_INFO
1831			       "apm: AC %s, battery status %s, battery life ",
1832			       power_stat, bat_stat);
1833			if ((cx & 0xff) == 0xff)
1834				printk("unknown\n");
1835			else
1836				printk("%d%%\n", cx & 0xff);
1837			if (apm_info.connection_version > 0x100) {
1838				printk(KERN_INFO
1839				       "apm: battery flag 0x%02x, battery life ",
1840				       (cx >> 8) & 0xff);
1841				if (dx == 0xffff)
1842					printk("unknown\n");
1843				else
1844					printk("%d %s\n", dx & 0x7fff,
1845					       (dx & 0x8000) ?
1846					       "minutes" : "seconds");
1847			}
1848		}
1849	}
1850
1851	/* Install our power off handler.. */
1852	if (power_off)
1853		pm_power_off = apm_power_off;
1854
1855	if (num_online_cpus() == 1 || smp) {
1856#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1857		console_blank_hook = apm_console_blank;
1858#endif
1859		apm_mainloop();
1860#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1861		console_blank_hook = NULL;
1862#endif
1863	}
1864
1865	return 0;
1866}
1867
1868#ifndef MODULE
1869static int __init apm_setup(char *str)
1870{
1871	int invert;
1872
1873	while ((str != NULL) && (*str != '\0')) {
1874		if (strncmp(str, "off", 3) == 0)
1875			apm_disabled = 1;
1876		if (strncmp(str, "on", 2) == 0)
1877			apm_disabled = 0;
1878		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1879		    (strncmp(str, "bounce_interval=", 16) == 0))
1880			bounce_interval = simple_strtol(str + 16, NULL, 0);
1881		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1882		    (strncmp(str, "idle_threshold=", 15) == 0))
1883			idle_threshold = simple_strtol(str + 15, NULL, 0);
1884		if ((strncmp(str, "idle-period=", 12) == 0) ||
1885		    (strncmp(str, "idle_period=", 12) == 0))
1886			idle_period = simple_strtol(str + 12, NULL, 0);
1887		invert = (strncmp(str, "no-", 3) == 0) ||
1888			(strncmp(str, "no_", 3) == 0);
1889		if (invert)
1890			str += 3;
1891		if (strncmp(str, "debug", 5) == 0)
1892			debug = !invert;
1893		if ((strncmp(str, "power-off", 9) == 0) ||
1894		    (strncmp(str, "power_off", 9) == 0))
1895			power_off = !invert;
1896		if (strncmp(str, "smp", 3) == 0) {
1897			smp = !invert;
1898			idle_threshold = 100;
1899		}
1900		if ((strncmp(str, "allow-ints", 10) == 0) ||
1901		    (strncmp(str, "allow_ints", 10) == 0))
1902			apm_info.allow_ints = !invert;
1903		if ((strncmp(str, "broken-psr", 10) == 0) ||
1904		    (strncmp(str, "broken_psr", 10) == 0))
1905			apm_info.get_power_status_broken = !invert;
1906		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1907		    (strncmp(str, "realmode_power_off", 18) == 0))
1908			apm_info.realmode_power_off = !invert;
1909		str = strchr(str, ',');
1910		if (str != NULL)
1911			str += strspn(str, ", \t");
1912	}
1913	return 1;
1914}
1915
1916__setup("apm=", apm_setup);
1917#endif
1918
1919static const struct file_operations apm_bios_fops = {
1920	.owner		= THIS_MODULE,
1921	.read		= do_read,
1922	.poll		= do_poll,
1923	.unlocked_ioctl	= do_ioctl,
1924	.open		= do_open,
1925	.release	= do_release,
1926	.llseek		= noop_llseek,
1927};
1928
1929static struct miscdevice apm_device = {
1930	APM_MINOR_DEV,
1931	"apm_bios",
1932	&apm_bios_fops
1933};
1934
1935
1936/* Simple "print if true" callback */
1937static int __init print_if_true(const struct dmi_system_id *d)
1938{
1939	printk("%s\n", d->ident);
1940	return 0;
1941}
1942
1943/*
1944 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1945 * disabled before the suspend. Linux used to get terribly confused by that.
1946 */
1947static int __init broken_ps2_resume(const struct dmi_system_id *d)
1948{
1949	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1950	       "workaround hopefully not needed.\n", d->ident);
1951	return 0;
1952}
1953
1954/* Some bioses have a broken protected mode poweroff and need to use realmode */
1955static int __init set_realmode_power_off(const struct dmi_system_id *d)
1956{
1957	if (apm_info.realmode_power_off == 0) {
1958		apm_info.realmode_power_off = 1;
1959		printk(KERN_INFO "%s bios detected. "
1960		       "Using realmode poweroff only.\n", d->ident);
1961	}
1962	return 0;
1963}
1964
1965/* Some laptops require interrupts to be enabled during APM calls */
1966static int __init set_apm_ints(const struct dmi_system_id *d)
1967{
1968	if (apm_info.allow_ints == 0) {
1969		apm_info.allow_ints = 1;
1970		printk(KERN_INFO "%s machine detected. "
1971		       "Enabling interrupts during APM calls.\n", d->ident);
1972	}
1973	return 0;
1974}
1975
1976/* Some APM bioses corrupt memory or just plain do not work */
1977static int __init apm_is_horked(const struct dmi_system_id *d)
1978{
1979	if (apm_info.disabled == 0) {
1980		apm_info.disabled = 1;
1981		printk(KERN_INFO "%s machine detected. "
1982		       "Disabling APM.\n", d->ident);
1983	}
1984	return 0;
1985}
1986
1987static int __init apm_is_horked_d850md(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		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1994		printk(KERN_INFO "download from support.intel.com\n");
1995	}
1996	return 0;
1997}
1998
1999/* Some APM bioses hang on APM idle calls */
2000static int __init apm_likes_to_melt(const struct dmi_system_id *d)
2001{
2002	if (apm_info.forbid_idle == 0) {
2003		apm_info.forbid_idle = 1;
2004		printk(KERN_INFO "%s machine detected. "
2005		       "Disabling APM idle calls.\n", d->ident);
2006	}
2007	return 0;
2008}
2009
2010/*
2011 *  Check for clue free BIOS implementations who use
2012 *  the following QA technique
2013 *
2014 *      [ Write BIOS Code ]<------
2015 *               |                ^
2016 *      < Does it Compile >----N--
2017 *               |Y               ^
2018 *	< Does it Boot Win98 >-N--
2019 *               |Y
2020 *           [Ship It]
2021 *
2022 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2023 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2024 */
2025static int __init broken_apm_power(const struct dmi_system_id *d)
2026{
2027	apm_info.get_power_status_broken = 1;
2028	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2029	       "disabling power status reporting.\n");
2030	return 0;
2031}
2032
2033/*
2034 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2035 * have this problem).
2036 */
2037static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2038{
2039	apm_info.get_power_status_swabinminutes = 1;
2040	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2041	       "in minutes and wrong byte order.\n");
2042	return 0;
2043}
2044
2045static struct dmi_system_id __initdata apm_dmi_table[] = {
2046	{
2047		print_if_true,
2048		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2049		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2050			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2051	},
2052	{	/* Handle problems with APM on the C600 */
2053		broken_ps2_resume, "Dell Latitude C600",
2054		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2055			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2056	},
2057	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2058		set_apm_ints, "Dell Latitude",
2059		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2060			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2061	},
2062	{	/* APM crashes */
2063		apm_is_horked, "Dell Inspiron 2500",
2064		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2065			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2066			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2067			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2068	},
2069	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2070		set_apm_ints, "Dell Inspiron", {
2071			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2072			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2073	},
2074	{	/* Handle problems with APM on Inspiron 5000e */
2075		broken_apm_power, "Dell Inspiron 5000e",
2076		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2077			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2078			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2079	},
2080	{	/* Handle problems with APM on Inspiron 2500 */
2081		broken_apm_power, "Dell Inspiron 2500",
2082		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2083			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2084			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2085	},
2086	{	/* APM crashes */
2087		apm_is_horked, "Dell Dimension 4100",
2088		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2089			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2090			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2091			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2092	},
2093	{	/* Allow interrupts during suspend on Compaq Laptops*/
2094		set_apm_ints, "Compaq 12XL125",
2095		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2096			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2097			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2098			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2099	},
2100	{	/* Allow interrupts during APM or the clock goes slow */
2101		set_apm_ints, "ASUSTeK",
2102		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2103			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2104	},
2105	{	/* APM blows on shutdown */
2106		apm_is_horked, "ABIT KX7-333[R]",
2107		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2108			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2109	},
2110	{	/* APM crashes */
2111		apm_is_horked, "Trigem Delhi3",
2112		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2113			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2114	},
2115	{	/* APM crashes */
2116		apm_is_horked, "Fujitsu-Siemens",
2117		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2118			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2119	},
2120	{	/* APM crashes */
2121		apm_is_horked_d850md, "Intel D850MD",
2122		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2123			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2124	},
2125	{	/* APM crashes */
2126		apm_is_horked, "Intel D810EMO",
2127		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2128			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2129	},
2130	{	/* APM crashes */
2131		apm_is_horked, "Dell XPS-Z",
2132		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2133			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2134			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2135	},
2136	{	/* APM crashes */
2137		apm_is_horked, "Sharp PC-PJ/AX",
2138		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2139			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2140			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2141			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2142	},
2143	{	/* APM crashes */
2144		apm_is_horked, "Dell Inspiron 2500",
2145		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2146			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2147			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2148			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2149	},
2150	{	/* APM idle hangs */
2151		apm_likes_to_melt, "Jabil AMD",
2152		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2153			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2154	},
2155	{	/* APM idle hangs */
2156		apm_likes_to_melt, "AMI Bios",
2157		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2158			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2159	},
2160	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2161		swab_apm_power_in_minutes, "Sony VAIO",
2162		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2163			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2164			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2165	},
2166	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2167		swab_apm_power_in_minutes, "Sony VAIO",
2168		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2169			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2170			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2171	},
2172	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2173		swab_apm_power_in_minutes, "Sony VAIO",
2174		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2175			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2176			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2177	},
2178	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2179		swab_apm_power_in_minutes, "Sony VAIO",
2180		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2181			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2182			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2183	},
2184	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2185		swab_apm_power_in_minutes, "Sony VAIO",
2186		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2187			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2188			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2189	},
2190	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2191		swab_apm_power_in_minutes, "Sony VAIO",
2192		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2193			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2194			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2195	},
2196	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2197		swab_apm_power_in_minutes, "Sony VAIO",
2198		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2199			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2200			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2201	},
2202	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2203		swab_apm_power_in_minutes, "Sony VAIO",
2204		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2205			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2206			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2207	},
2208	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2209		swab_apm_power_in_minutes, "Sony VAIO",
2210		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2211			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2212			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2213	},
2214	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2215		swab_apm_power_in_minutes, "Sony VAIO",
2216		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2217			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2218			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2219	},
2220
2221	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2222		swab_apm_power_in_minutes, "Sony VAIO",
2223		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2224			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2225			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2226	},
2227	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2228		swab_apm_power_in_minutes, "Sony VAIO",
2229		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2230			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2231			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2232	},
2233	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2234		swab_apm_power_in_minutes, "Sony VAIO",
2235		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2236			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2237			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2238	},
2239	{	/* broken PM poweroff bios */
2240		set_realmode_power_off, "Award Software v4.60 PGMA",
2241		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2242			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2243			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2244	},
2245
2246	/* Generic per vendor APM settings  */
2247
2248	{	/* Allow interrupts during suspend on IBM laptops */
2249		set_apm_ints, "IBM",
2250		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2251	},
2252
2253	{ }
2254};
2255
2256/*
2257 * Just start the APM thread. We do NOT want to do APM BIOS
2258 * calls from anything but the APM thread, if for no other reason
2259 * than the fact that we don't trust the APM BIOS. This way,
2260 * most common APM BIOS problems that lead to protection errors
2261 * etc will have at least some level of being contained...
2262 *
2263 * In short, if something bad happens, at least we have a choice
2264 * of just killing the apm thread..
2265 */
2266static int __init apm_init(void)
2267{
2268	struct desc_struct *gdt;
2269	int err;
2270
2271	dmi_check_system(apm_dmi_table);
2272
2273	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2274		printk(KERN_INFO "apm: BIOS not found.\n");
2275		return -ENODEV;
2276	}
2277	printk(KERN_INFO
2278	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2279	       ((apm_info.bios.version >> 8) & 0xff),
2280	       (apm_info.bios.version & 0xff),
2281	       apm_info.bios.flags,
2282	       driver_version);
2283	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2284		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2285		return -ENODEV;
2286	}
2287
2288	if (allow_ints)
2289		apm_info.allow_ints = 1;
2290	if (broken_psr)
2291		apm_info.get_power_status_broken = 1;
2292	if (realmode_power_off)
2293		apm_info.realmode_power_off = 1;
2294	/* User can override, but default is to trust DMI */
2295	if (apm_disabled != -1)
2296		apm_info.disabled = apm_disabled;
2297
2298	/*
2299	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2300	 * but is reportedly a 1.0 BIOS.
2301	 */
2302	if (apm_info.bios.version == 0x001)
2303		apm_info.bios.version = 0x100;
2304
2305	/* BIOS < 1.2 doesn't set cseg_16_len */
2306	if (apm_info.bios.version < 0x102)
2307		apm_info.bios.cseg_16_len = 0; /* 64k */
2308
2309	if (debug) {
2310		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2311			apm_info.bios.cseg, apm_info.bios.offset,
2312			apm_info.bios.cseg_16, apm_info.bios.dseg);
2313		if (apm_info.bios.version > 0x100)
2314			printk(" cseg len %x, dseg len %x",
2315				apm_info.bios.cseg_len,
2316				apm_info.bios.dseg_len);
2317		if (apm_info.bios.version > 0x101)
2318			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2319		printk("\n");
2320	}
2321
2322	if (apm_info.disabled) {
2323		pr_notice("disabled on user request.\n");
2324		return -ENODEV;
2325	}
2326	if ((num_online_cpus() > 1) && !power_off && !smp) {
2327		pr_notice("disabled - APM is not SMP safe.\n");
2328		apm_info.disabled = 1;
2329		return -ENODEV;
2330	}
2331	if (!acpi_disabled) {
2332		pr_notice("overridden by ACPI.\n");
2333		apm_info.disabled = 1;
2334		return -ENODEV;
2335	}
2336
2337	/*
2338	 * Set up the long jump entry point to the APM BIOS, which is called
2339	 * from inline assembly.
2340	 */
2341	apm_bios_entry.offset = apm_info.bios.offset;
2342	apm_bios_entry.segment = APM_CS;
2343
2344	/*
2345	 * The APM 1.1 BIOS is supposed to provide limit information that it
2346	 * recognizes.  Many machines do this correctly, but many others do
2347	 * not restrict themselves to their claimed limit.  When this happens,
2348	 * they will cause a segmentation violation in the kernel at boot time.
2349	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2350	 *
2351	 * Note we only set APM segments on CPU zero, since we pin the APM
2352	 * code to that CPU.
2353	 */
2354	gdt = get_cpu_gdt_table(0);
2355	set_desc_base(&gdt[APM_CS >> 3],
2356		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2357	set_desc_base(&gdt[APM_CS_16 >> 3],
2358		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2359	set_desc_base(&gdt[APM_DS >> 3],
2360		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2361
2362	proc_create("apm", 0, NULL, &apm_file_ops);
2363
2364	kapmd_task = kthread_create(apm, NULL, "kapmd");
2365	if (IS_ERR(kapmd_task)) {
2366		pr_err("disabled - Unable to start kernel thread\n");
2367		err = PTR_ERR(kapmd_task);
2368		kapmd_task = NULL;
2369		remove_proc_entry("apm", NULL);
2370		return err;
2371	}
2372	wake_up_process(kapmd_task);
2373
2374	if (num_online_cpus() > 1 && !smp) {
2375		printk(KERN_NOTICE
2376		       "apm: disabled - APM is not SMP safe (power off active).\n");
2377		return 0;
2378	}
2379
2380	/*
2381	 * Note we don't actually care if the misc_device cannot be registered.
2382	 * this driver can do its job without it, even if userspace can't
2383	 * control it.  just log the error
2384	 */
2385	if (misc_register(&apm_device))
2386		printk(KERN_WARNING "apm: Could not register misc device.\n");
2387
2388	if (HZ != 100)
2389		idle_period = (idle_period * HZ) / 100;
2390	if (idle_threshold < 100) {
 
2391		if (!cpuidle_register_driver(&apm_idle_driver))
2392			if (cpuidle_register_device(&apm_cpuidle_device))
2393				cpuidle_unregister_driver(&apm_idle_driver);
2394	}
2395
2396	return 0;
2397}
2398
2399static void __exit apm_exit(void)
2400{
2401	int error;
2402
2403	cpuidle_unregister_device(&apm_cpuidle_device);
2404	cpuidle_unregister_driver(&apm_idle_driver);
2405
2406	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2407	    && (apm_info.connection_version > 0x0100)) {
2408		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2409		if (error)
2410			apm_error("disengage power management", error);
2411	}
2412	misc_deregister(&apm_device);
2413	remove_proc_entry("apm", NULL);
2414	if (power_off)
2415		pm_power_off = NULL;
2416	if (kapmd_task) {
2417		kthread_stop(kapmd_task);
2418		kapmd_task = NULL;
2419	}
2420}
2421
2422module_init(apm_init);
2423module_exit(apm_exit);
2424
2425MODULE_AUTHOR("Stephen Rothwell");
2426MODULE_DESCRIPTION("Advanced Power Management");
2427MODULE_LICENSE("GPL");
2428module_param(debug, bool, 0644);
2429MODULE_PARM_DESC(debug, "Enable debug mode");
2430module_param(power_off, bool, 0444);
2431MODULE_PARM_DESC(power_off, "Enable power off");
2432module_param(bounce_interval, int, 0444);
2433MODULE_PARM_DESC(bounce_interval,
2434		"Set the number of ticks to ignore suspend bounces");
2435module_param(allow_ints, bool, 0444);
2436MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2437module_param(broken_psr, bool, 0444);
2438MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2439module_param(realmode_power_off, bool, 0444);
2440MODULE_PARM_DESC(realmode_power_off,
2441		"Switch to real mode before powering off");
2442module_param(idle_threshold, int, 0444);
2443MODULE_PARM_DESC(idle_threshold,
2444	"System idle percentage above which to make APM BIOS idle calls");
2445module_param(idle_period, int, 0444);
2446MODULE_PARM_DESC(idle_period,
2447	"Period (in sec/100) over which to caculate the idle percentage");
2448module_param(smp, bool, 0444);
2449MODULE_PARM_DESC(smp,
2450	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2451MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
v6.8
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* -*- linux-c -*-
   3 * APM BIOS driver for Linux
   4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   5 *
   6 * Initial development of this driver was funded by NEC Australia P/L
   7 *	and NEC Corporation
   8 *
 
 
 
 
 
 
 
 
 
 
   9 * October 1995, Rik Faith (faith@cs.unc.edu):
  10 *    Minor enhancements and updates (to the patch set) for 1.3.x
  11 *    Documentation
  12 * January 1996, Rik Faith (faith@cs.unc.edu):
  13 *    Make /proc/apm easy to format (bump driver version)
  14 * March 1996, Rik Faith (faith@cs.unc.edu):
  15 *    Prohibit APM BIOS calls unless apm_enabled.
  16 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  18 *    Version 1.0 and 1.1
  19 * May 1996, Version 1.2
  20 * Feb 1998, Version 1.3
  21 * Feb 1998, Version 1.4
  22 * Aug 1998, Version 1.5
  23 * Sep 1998, Version 1.6
  24 * Nov 1998, Version 1.7
  25 * Jan 1999, Version 1.8
  26 * Jan 1999, Version 1.9
  27 * Oct 1999, Version 1.10
  28 * Nov 1999, Version 1.11
  29 * Jan 2000, Version 1.12
  30 * Feb 2000, Version 1.13
  31 * Nov 2000, Version 1.14
  32 * Oct 2001, Version 1.15
  33 * Jan 2002, Version 1.16
  34 * Oct 2002, Version 1.16ac
  35 *
  36 * History:
  37 *    0.6b: first version in official kernel, Linux 1.3.46
  38 *    0.7: changed /proc/apm format, Linux 1.3.58
  39 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  40 *    0.9: only call bios if bios is present, Linux 1.3.72
  41 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  42 *         Linux 1.3.85
  43 *    1.1: support user-space standby and suspend, power off after system
  44 *         halted, Linux 1.3.98
  45 *    1.2: When resetting RTC after resume, take care so that the time
  46 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  47 *         <jtoth@princeton.edu>); improve interaction between
  48 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  49 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  50 *	   levels to the printk calls. APM is not defined for SMP machines.
  51 *         The new replacement for it is, but Linux doesn't yet support this.
  52 *         Alan Cox Linux 2.1.55
  53 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  54 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  55 *         Dean Gaudet <dgaudet@arctic.org>.
  56 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  57 *    1.5: Fix segment register reloading (in case of bad segments saved
  58 *         across BIOS call).
  59 *         Stephen Rothwell
  60 *    1.6: Cope with compiler/assembler differences.
  61 *         Only try to turn off the first display device.
  62 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  63 *                   <echter@informatik.uni-rostock.de>
  64 *         Stephen Rothwell
  65 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  66 *         to reflect current state of APM BIOS.
  67 *         Chris Rankin <rankinc@bellsouth.net>
  68 *         Reset interrupt 0 timer to 100Hz after suspend
  69 *         Chad Miller <cmiller@surfsouth.com>
  70 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  71 *         Richard Gooch <rgooch@atnf.csiro.au>
  72 *         Allow boot time disabling of APM
  73 *         Make boot messages far less verbose by default
  74 *         Make asm safer
  75 *         Stephen Rothwell
  76 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  77 *         Richard Gooch <rgooch@atnf.csiro.au>
  78 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  79 *         remove dependency on CONFIG_PROC_FS
  80 *         Stephen Rothwell
  81 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  82 *         Try to cope with BIOS's that need to have all display
  83 *         devices blanked and not just the first one.
  84 *         Ross Paterson <ross@soi.city.ac.uk>
  85 *         Fix segment limit setting it has always been wrong as
  86 *         the segments needed to have byte granularity.
  87 *         Mark a few things __init.
  88 *         Add hack to allow power off of SMP systems by popular request.
  89 *         Use CONFIG_SMP instead of __SMP__
  90 *         Ignore BOUNCES for three seconds.
  91 *         Stephen Rothwell
  92 *   1.10: Fix for Thinkpad return code.
  93 *         Merge 2.2 and 2.3 drivers.
  94 *         Remove APM dependencies in arch/i386/kernel/process.c
  95 *         Remove APM dependencies in drivers/char/sysrq.c
  96 *         Reset time across standby.
  97 *         Allow more initialisation on SMP.
  98 *         Remove CONFIG_APM_POWER_OFF and make it boot time
  99 *         configurable (default on).
 100 *         Make debug only a boot time parameter (remove APM_DEBUG).
 101 *         Try to blank all devices on any error.
 102 *   1.11: Remove APM dependencies in drivers/char/console.c
 103 *         Check nr_running to detect if we are idle (from
 104 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 105 *         Fix for bioses that don't zero the top part of the
 106 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 107 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 108 *         Real mode power off patch (Walter Hofmann
 109 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 110 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 111 *         the code away anyway (smp_num_cpus == 1 in UP)
 112 *         noted by Artur Skawina <skawina@geocities.com>.
 113 *         Make power off under SMP work again.
 114 *         Fix thinko with initial engaging of BIOS.
 115 *         Make sure power off only happens on CPU 0
 116 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 117 *         Do error notification to user mode if BIOS calls fail.
 118 *         Move entrypoint offset fix to ...boot/setup.S
 119 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 120 *         Remove smp-power-off. SMP users must now specify
 121 *         "apm=power-off" on the kernel command line. Suggested
 122 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 123 *         <alan@lxorguk.ukuu.org.uk>.
 124 *         Register the /proc/apm entry even on SMP so that
 125 *         scripts that check for it before doing power off
 126 *         work (Jim Avera <jima@hal.com>).
 127 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 128 *         <andy_henroid@yahoo.com>).
 129 *         Modularize the code.
 130 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 131 *         is now the way life works).
 132 *         Fix thinko in suspend() (wrong return).
 133 *         Notify drivers on critical suspend.
 134 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 135 *         modified by sfr).
 136 *         Disable interrupts while we are suspended (Andy Henroid
 137 *         <andy_henroid@yahoo.com> fixed by sfr).
 138 *         Make power off work on SMP again (Tony Hoyle
 139 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 140 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 141 *         interval is now configurable.
 142 *   1.14: Make connection version persist across module unload/load.
 143 *         Enable and engage power management earlier.
 144 *         Disengage power management on module unload.
 145 *         Changed to use the sysrq-register hack for registering the
 146 *         power off function called by magic sysrq based upon discussions
 147 *         in irc://irc.openprojects.net/#kernelnewbies
 148 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 149 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 150 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 151 *         Work around byte swap bug in one of the Vaio's BIOS's
 152 *         (Marc Boucher <marc@mbsi.ca>).
 153 *         Exposed the disable flag to dmi so that we can handle known
 154 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 155 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 156 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 157 *         If an APM idle fails log it and idle sensibly
 158 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 159 *         Don't expect replies from clients who open the device O_RDONLY.
 160 *         (Idea from Thomas Hood)
 161 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 162 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 163 *         Notify listeners of standby or suspend events before notifying
 164 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 165 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 166 *         Ignore first resume after we generate our own resume event
 167 *         after a suspend (Thomas Hood)
 168 *         Daemonize now gets rid of our controlling terminal (sfr).
 169 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 170 *         idle_threshold (sfr).
 171 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 172 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 173 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 174 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 175 *
 176 * APM 1.1 Reference:
 177 *
 178 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 179 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 180 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 181 *
 182 * [This document is available free from Intel by calling 800.628.8686 (fax
 183 * 916.356.6100) or 800.548.4725; or from
 184 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 185 * available from Microsoft by calling 206.882.8080.]
 186 *
 187 * APM 1.2 Reference:
 188 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 189 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 190 *
 191 * [This document is available from Microsoft at:
 192 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 193 */
 194
 195#define pr_fmt(fmt) "apm: " fmt
 196
 197#include <linux/module.h>
 198
 199#include <linux/poll.h>
 200#include <linux/types.h>
 201#include <linux/stddef.h>
 202#include <linux/timer.h>
 203#include <linux/fcntl.h>
 204#include <linux/slab.h>
 205#include <linux/stat.h>
 206#include <linux/proc_fs.h>
 207#include <linux/seq_file.h>
 208#include <linux/miscdevice.h>
 209#include <linux/apm_bios.h>
 210#include <linux/init.h>
 211#include <linux/time.h>
 212#include <linux/sched/signal.h>
 213#include <linux/sched/cputime.h>
 214#include <linux/pm.h>
 215#include <linux/capability.h>
 216#include <linux/device.h>
 217#include <linux/kernel.h>
 218#include <linux/freezer.h>
 219#include <linux/smp.h>
 220#include <linux/dmi.h>
 221#include <linux/suspend.h>
 222#include <linux/kthread.h>
 223#include <linux/jiffies.h>
 224#include <linux/acpi.h>
 225#include <linux/syscore_ops.h>
 226#include <linux/i8253.h>
 227#include <linux/cpuidle.h>
 228
 229#include <linux/uaccess.h>
 230#include <asm/desc.h>
 231#include <asm/olpc.h>
 232#include <asm/paravirt.h>
 233#include <asm/reboot.h>
 234#include <asm/nospec-branch.h>
 235#include <asm/ibt.h>
 236
 237#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 238extern int (*console_blank_hook)(int);
 239#endif
 240
 241/*
 
 
 
 
 
 
 242 * Various options can be changed at boot time as follows:
 243 * (We allow underscores for compatibility with the modules code)
 244 *	apm=on/off			enable/disable APM
 245 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 246 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 247 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 248 *	    					powering off
 249 *	    [no-]debug			log some debugging messages
 250 *	    [no-]power[-_]off		power off on shutdown
 251 *	    [no-]smp			Use apm even on an SMP box
 252 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 253 *	    				bounces
 254 *          idle[-_]threshold=<n>       System idle percentage above which to
 255 *                                      make APM BIOS idle calls. Set it to
 256 *                                      100 to disable.
 257 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 258 *                                      which the idle percentage is
 259 *                                      calculated.
 260 */
 261
 262/* KNOWN PROBLEM MACHINES:
 263 *
 264 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 265 *                         [Confirmed by TI representative]
 266 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 267 *                    [Confirmed by BIOS disassembly]
 268 *                    [This may work now ...]
 269 * P: Toshiba 1950S: battery life information only gets updated after resume
 270 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 271 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 272 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 273 * 	Neale Banks <neale@lowendale.com.au> December 2000
 274 *
 275 * Legend: U = unusable with APM patches
 276 *         P = partially usable with APM patches
 277 */
 278
 279/*
 280 * Define as 1 to make the driver always call the APM BIOS busy
 281 * routine even if the clock was not reported as slowed by the
 282 * idle routine.  Otherwise, define as 0.
 283 */
 284#define ALWAYS_CALL_BUSY   1
 285
 286/*
 287 * Define to make the APM BIOS calls zero all data segment registers (so
 288 * that an incorrect BIOS implementation will cause a kernel panic if it
 289 * tries to write to arbitrary memory).
 290 */
 291#define APM_ZERO_SEGS
 292
 293#include <asm/apm.h>
 294
 295/*
 296 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 297 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 298 * David Chen <chen@ctpa04.mit.edu>
 299 */
 300#undef INIT_TIMER_AFTER_SUSPEND
 301
 302#ifdef INIT_TIMER_AFTER_SUSPEND
 303#include <linux/timex.h>
 304#include <asm/io.h>
 305#include <linux/delay.h>
 306#endif
 307
 308/*
 309 * Need to poll the APM BIOS every second
 310 */
 311#define APM_CHECK_TIMEOUT	(HZ)
 312
 313/*
 314 * Ignore suspend events for this amount of time after a resume
 315 */
 316#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 317
 318/*
 319 * Maximum number of events stored
 320 */
 321#define APM_MAX_EVENTS		20
 322
 323/*
 324 * The per-file APM data
 325 */
 326struct apm_user {
 327	int		magic;
 328	struct apm_user *next;
 329	unsigned int	suser: 1;
 330	unsigned int	writer: 1;
 331	unsigned int	reader: 1;
 332	unsigned int	suspend_wait: 1;
 333	int		suspend_result;
 334	int		suspends_pending;
 335	int		standbys_pending;
 336	int		suspends_read;
 337	int		standbys_read;
 338	int		event_head;
 339	int		event_tail;
 340	apm_event_t	events[APM_MAX_EVENTS];
 341};
 342
 343/*
 344 * The magic number in apm_user
 345 */
 346#define APM_BIOS_MAGIC		0x4101
 347
 348/*
 349 * idle percentage above which bios idle calls are done
 350 */
 351#ifdef CONFIG_APM_CPU_IDLE
 352#define DEFAULT_IDLE_THRESHOLD	95
 353#else
 354#define DEFAULT_IDLE_THRESHOLD	100
 355#endif
 356#define DEFAULT_IDLE_PERIOD	(100 / 3)
 357
 358static int apm_cpu_idle(struct cpuidle_device *dev,
 359			struct cpuidle_driver *drv, int index);
 360
 361static struct cpuidle_driver apm_idle_driver = {
 362	.name = "apm_idle",
 363	.owner = THIS_MODULE,
 364	.states = {
 365		{ /* entry 0 is for polling */ },
 366		{ /* entry 1 is for APM idle */
 367			.name = "APM",
 368			.desc = "APM idle",
 369			.exit_latency = 250,	/* WAG */
 370			.target_residency = 500,	/* WAG */
 371			.enter = &apm_cpu_idle
 372		},
 373	},
 374	.state_count = 2,
 375};
 376
 377static struct cpuidle_device apm_cpuidle_device;
 378
 379/*
 380 * Local variables
 381 */
 382__visible struct {
 383	unsigned long	offset;
 384	unsigned short	segment;
 385} apm_bios_entry;
 386static int clock_slowed;
 387static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 388static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 389static int suspends_pending;
 390static int standbys_pending;
 391static int ignore_sys_suspend;
 392static int ignore_normal_resume;
 393static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 394
 395static bool debug __read_mostly;
 396static bool smp __read_mostly;
 397static int apm_disabled = -1;
 398#ifdef CONFIG_SMP
 399static bool power_off;
 400#else
 401static bool power_off = 1;
 402#endif
 403static bool realmode_power_off;
 404#ifdef CONFIG_APM_ALLOW_INTS
 405static bool allow_ints = 1;
 406#else
 407static bool allow_ints;
 408#endif
 409static bool broken_psr;
 410
 411static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 412static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 413static struct apm_user *user_list;
 414static DEFINE_SPINLOCK(user_list_lock);
 415static DEFINE_MUTEX(apm_mutex);
 416
 417/*
 418 * Set up a segment that references the real mode segment 0x40
 419 * that extends up to the end of page zero (that we have reserved).
 420 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 421 * even though they are called in protected mode.
 422 */
 423static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(DESC_DATA32_BIOS,
 424			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 425
 426static const char driver_version[] = "1.16ac";	/* no spaces */
 427
 428static struct task_struct *kapmd_task;
 429
 430/*
 431 *	APM event names taken from the APM 1.2 specification. These are
 432 *	the message codes that the BIOS uses to tell us about events
 433 */
 434static const char * const apm_event_name[] = {
 435	"system standby",
 436	"system suspend",
 437	"normal resume",
 438	"critical resume",
 439	"low battery",
 440	"power status change",
 441	"update time",
 442	"critical suspend",
 443	"user standby",
 444	"user suspend",
 445	"system standby resume",
 446	"capabilities change"
 447};
 448#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 449
 450typedef struct lookup_t {
 451	int	key;
 452	char 	*msg;
 453} lookup_t;
 454
 455/*
 456 *	The BIOS returns a set of standard error codes in AX when the
 457 *	carry flag is set.
 458 */
 459
 460static const lookup_t error_table[] = {
 461/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 462	{ APM_DISABLED,		"Power management disabled" },
 463	{ APM_CONNECTED,	"Real mode interface already connected" },
 464	{ APM_NOT_CONNECTED,	"Interface not connected" },
 465	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 466/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 467	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 468	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 469	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 470	{ APM_BAD_PARAM,	"Parameter out of range" },
 471	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 472	{ APM_BAD_FUNCTION,     "Function not supported" },
 473	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 474	{ APM_BAD_STATE,	"Unable to enter requested state" },
 475/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 476	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 477	{ APM_NOT_PRESENT,	"No APM present" }
 478};
 479#define ERROR_COUNT	ARRAY_SIZE(error_table)
 480
 481/**
 482 *	apm_error	-	display an APM error
 483 *	@str: information string
 484 *	@err: APM BIOS return code
 485 *
 486 *	Write a meaningful log entry to the kernel log in the event of
 487 *	an APM error.  Note that this also handles (negative) kernel errors.
 488 */
 489
 490static void apm_error(char *str, int err)
 491{
 492	int i;
 493
 494	for (i = 0; i < ERROR_COUNT; i++)
 495		if (error_table[i].key == err)
 496			break;
 497	if (i < ERROR_COUNT)
 498		pr_notice("%s: %s\n", str, error_table[i].msg);
 499	else if (err < 0)
 500		pr_notice("%s: linux error code %i\n", str, err);
 501	else
 502		pr_notice("%s: unknown error code %#2.2x\n",
 503		       str, err);
 504}
 505
 506/*
 507 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 508 * apm_info.allow_ints, we are being really paranoid here!  Not only
 509 * are interrupts disabled, but all the segment registers (except SS)
 510 * are saved and zeroed this means that if the BIOS tries to reference
 511 * any data without explicitly loading the segment registers, the kernel
 512 * will fault immediately rather than have some unforeseen circumstances
 513 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 514 * this depends on CS referring to the same physical memory as DS so that
 515 * DS can be zeroed before the call. Unfortunately, we can't do anything
 516 * about the stack segment/pointer.  Also, we tell the compiler that
 517 * everything could change.
 518 *
 519 * Also, we KNOW that for the non error case of apm_bios_call, there
 520 * is no useful data returned in the low order 8 bits of eax.
 521 */
 522
 523static inline unsigned long __apm_irq_save(void)
 524{
 525	unsigned long flags;
 526	local_save_flags(flags);
 527	if (apm_info.allow_ints) {
 528		if (irqs_disabled_flags(flags))
 529			local_irq_enable();
 530	} else
 531		local_irq_disable();
 532
 533	return flags;
 534}
 535
 536#define apm_irq_save(flags) \
 537	do { flags = __apm_irq_save(); } while (0)
 538
 539static inline void apm_irq_restore(unsigned long flags)
 540{
 541	if (irqs_disabled_flags(flags))
 542		local_irq_disable();
 543	else if (irqs_disabled())
 544		local_irq_enable();
 545}
 546
 547#ifdef APM_ZERO_SEGS
 548#	define APM_DECL_SEGS \
 549		unsigned int saved_fs; unsigned int saved_gs;
 550#	define APM_DO_SAVE_SEGS \
 551		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 552#	define APM_DO_RESTORE_SEGS \
 553		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 554#else
 555#	define APM_DECL_SEGS
 556#	define APM_DO_SAVE_SEGS
 557#	define APM_DO_RESTORE_SEGS
 558#endif
 559
 560struct apm_bios_call {
 561	u32 func;
 562	/* In and out */
 563	u32 ebx;
 564	u32 ecx;
 565	/* Out only */
 566	u32 eax;
 567	u32 edx;
 568	u32 esi;
 569
 570	/* Error: -ENOMEM, or bits 8-15 of eax */
 571	int err;
 572};
 573
 574/**
 575 *	__apm_bios_call - Make an APM BIOS 32bit call
 576 *	@_call: pointer to struct apm_bios_call.
 577 *
 578 *	Make an APM call using the 32bit protected mode interface. The
 579 *	caller is responsible for knowing if APM BIOS is configured and
 580 *	enabled. This call can disable interrupts for a long period of
 581 *	time on some laptops.  The return value is in AH and the carry
 582 *	flag is loaded into AL.  If there is an error, then the error
 583 *	code is returned in AH (bits 8-15 of eax) and this function
 584 *	returns non-zero.
 585 *
 586 *	Note: this makes the call on the current CPU.
 587 */
 588static long __apm_bios_call(void *_call)
 589{
 590	APM_DECL_SEGS
 591	unsigned long		flags;
 592	int			cpu;
 593	struct desc_struct	save_desc_40;
 594	struct desc_struct	*gdt;
 595	struct apm_bios_call	*call = _call;
 596	u64			ibt;
 597
 598	cpu = get_cpu();
 599	BUG_ON(cpu != 0);
 600	gdt = get_cpu_gdt_rw(cpu);
 601	save_desc_40 = gdt[0x40 / 8];
 602	gdt[0x40 / 8] = bad_bios_desc;
 603
 604	apm_irq_save(flags);
 605	firmware_restrict_branch_speculation_start();
 606	ibt = ibt_save(true);
 607	APM_DO_SAVE_SEGS;
 608	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 609			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 610			  &call->esi);
 611	APM_DO_RESTORE_SEGS;
 612	ibt_restore(ibt);
 613	firmware_restrict_branch_speculation_end();
 614	apm_irq_restore(flags);
 615	gdt[0x40 / 8] = save_desc_40;
 616	put_cpu();
 617
 618	return call->eax & 0xff;
 619}
 620
 621/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 622static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 623{
 624	int ret;
 625
 626	/* Don't bother with work_on_cpu in the common case, so we don't
 627	 * have to worry about OOM or overhead. */
 628	if (get_cpu() == 0) {
 629		ret = fn(call);
 630		put_cpu();
 631	} else {
 632		put_cpu();
 633		ret = work_on_cpu(0, fn, call);
 634	}
 635
 636	/* work_on_cpu can fail with -ENOMEM */
 637	if (ret < 0)
 638		call->err = ret;
 639	else
 640		call->err = (call->eax >> 8) & 0xff;
 641
 642	return ret;
 643}
 644
 645/**
 646 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 647 *	@call: the apm_bios_call registers.
 648 *
 649 *	If there is an error, it is returned in @call.err.
 650 */
 651static int apm_bios_call(struct apm_bios_call *call)
 652{
 653	return on_cpu0(__apm_bios_call, call);
 654}
 655
 656/**
 657 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 658 *	@_call: pointer to struct apm_bios_call.
 659 *
 660 *	Make a BIOS call that returns one value only, or just status.
 661 *	If there is an error, then the error code is returned in AH
 662 *	(bits 8-15 of eax) and this function returns non-zero (it can
 663 *	also return -ENOMEM). This is used for simpler BIOS operations.
 664 *	This call may hold interrupts off for a long time on some laptops.
 665 *
 666 *	Note: this makes the call on the current CPU.
 667 */
 668static long __apm_bios_call_simple(void *_call)
 669{
 670	u8			error;
 671	APM_DECL_SEGS
 672	unsigned long		flags;
 673	int			cpu;
 674	struct desc_struct	save_desc_40;
 675	struct desc_struct	*gdt;
 676	struct apm_bios_call	*call = _call;
 677	u64			ibt;
 678
 679	cpu = get_cpu();
 680	BUG_ON(cpu != 0);
 681	gdt = get_cpu_gdt_rw(cpu);
 682	save_desc_40 = gdt[0x40 / 8];
 683	gdt[0x40 / 8] = bad_bios_desc;
 684
 685	apm_irq_save(flags);
 686	firmware_restrict_branch_speculation_start();
 687	ibt = ibt_save(true);
 688	APM_DO_SAVE_SEGS;
 689	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 690					 &call->eax);
 691	APM_DO_RESTORE_SEGS;
 692	ibt_restore(ibt);
 693	firmware_restrict_branch_speculation_end();
 694	apm_irq_restore(flags);
 695	gdt[0x40 / 8] = save_desc_40;
 696	put_cpu();
 697	return error;
 698}
 699
 700/**
 701 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 702 *	@func: APM function to invoke
 703 *	@ebx_in: EBX register value for BIOS call
 704 *	@ecx_in: ECX register value for BIOS call
 705 *	@eax: EAX register on return from the BIOS call
 706 *	@err: bits
 707 *
 708 *	Make a BIOS call that returns one value only, or just status.
 709 *	If there is an error, then the error code is returned in @err
 710 *	and this function returns non-zero. This is used for simpler
 711 *	BIOS operations.  This call may hold interrupts off for a long
 712 *	time on some laptops.
 713 */
 714static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 715				int *err)
 716{
 717	struct apm_bios_call call;
 718	int ret;
 719
 720	call.func = func;
 721	call.ebx = ebx_in;
 722	call.ecx = ecx_in;
 723
 724	ret = on_cpu0(__apm_bios_call_simple, &call);
 725	*eax = call.eax;
 726	*err = call.err;
 727	return ret;
 728}
 729
 730/**
 731 *	apm_driver_version	-	APM driver version
 732 *	@val:	loaded with the APM version on return
 733 *
 734 *	Retrieve the APM version supported by the BIOS. This is only
 735 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 736 *	probably present.
 737 *
 738 *	On entry val should point to a value indicating the APM driver
 739 *	version with the high byte being the major and the low byte the
 740 *	minor number both in BCD
 741 *
 742 *	On return it will hold the BIOS revision supported in the
 743 *	same format.
 744 */
 745
 746static int apm_driver_version(u_short *val)
 747{
 748	u32 eax;
 749	int err;
 750
 751	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 752		return err;
 753	*val = eax;
 754	return APM_SUCCESS;
 755}
 756
 757/**
 758 *	apm_get_event	-	get an APM event from the BIOS
 759 *	@event: pointer to the event
 760 *	@info: point to the event information
 761 *
 762 *	The APM BIOS provides a polled information for event
 763 *	reporting. The BIOS expects to be polled at least every second
 764 *	when events are pending. When a message is found the caller should
 765 *	poll until no more messages are present.  However, this causes
 766 *	problems on some laptops where a suspend event notification is
 767 *	not cleared until it is acknowledged.
 768 *
 769 *	Additional information is returned in the info pointer, providing
 770 *	that APM 1.2 is in use. If no messages are pending the value 0x80
 771 *	is returned (No power management events pending).
 772 */
 773static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 774{
 775	struct apm_bios_call call;
 776
 777	call.func = APM_FUNC_GET_EVENT;
 778	call.ebx = call.ecx = 0;
 779
 780	if (apm_bios_call(&call))
 781		return call.err;
 782
 783	*event = call.ebx;
 784	if (apm_info.connection_version < 0x0102)
 785		*info = ~0; /* indicate info not valid */
 786	else
 787		*info = call.ecx;
 788	return APM_SUCCESS;
 789}
 790
 791/**
 792 *	set_power_state	-	set the power management state
 793 *	@what: which items to transition
 794 *	@state: state to transition to
 795 *
 796 *	Request an APM change of state for one or more system devices. The
 797 *	processor state must be transitioned last of all. what holds the
 798 *	class of device in the upper byte and the device number (0xFF for
 799 *	all) for the object to be transitioned.
 800 *
 801 *	The state holds the state to transition to, which may in fact
 802 *	be an acceptance of a BIOS requested state change.
 803 */
 804
 805static int set_power_state(u_short what, u_short state)
 806{
 807	u32 eax;
 808	int err;
 809
 810	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 811		return err;
 812	return APM_SUCCESS;
 813}
 814
 815/**
 816 *	set_system_power_state - set system wide power state
 817 *	@state: which state to enter
 818 *
 819 *	Transition the entire system into a new APM power state.
 820 */
 821
 822static int set_system_power_state(u_short state)
 823{
 824	return set_power_state(APM_DEVICE_ALL, state);
 825}
 826
 827/**
 828 *	apm_do_idle	-	perform power saving
 829 *
 830 *	This function notifies the BIOS that the processor is (in the view
 831 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 832 *	to handle the idle request. On a success the function returns 1
 833 *	if the BIOS did clock slowing or 0 otherwise.
 834 */
 835
 836static int apm_do_idle(void)
 837{
 838	u32 eax;
 839	u8 ret = 0;
 840	int idled = 0;
 841	int err = 0;
 842
 843	if (!need_resched()) {
 844		idled = 1;
 845		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 846	}
 847
 848	if (!idled)
 849		return 0;
 850
 851	if (ret) {
 852		static unsigned long t;
 853
 854		/* This always fails on some SMP boards running UP kernels.
 855		 * Only report the failure the first 5 times.
 856		 */
 857		if (++t < 5) {
 858			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 859			t = jiffies;
 860		}
 861		return -1;
 862	}
 863	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 864	return clock_slowed;
 865}
 866
 867/**
 868 *	apm_do_busy	-	inform the BIOS the CPU is busy
 869 *
 870 *	Request that the BIOS brings the CPU back to full performance.
 871 */
 872
 873static void apm_do_busy(void)
 874{
 875	u32 dummy;
 876	int err;
 877
 878	if (clock_slowed || ALWAYS_CALL_BUSY) {
 879		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 880		clock_slowed = 0;
 881	}
 882}
 883
 884/*
 885 * If no process has really been interested in
 886 * the CPU for some time, we want to call BIOS
 887 * power management - we probably want
 888 * to conserve power.
 889 */
 890#define IDLE_CALC_LIMIT	(HZ * 100)
 891#define IDLE_LEAKY_MAX	16
 892
 893/**
 894 * apm_cpu_idle		-	cpu idling for APM capable Linux
 895 *
 896 * This is the idling function the kernel executes when APM is available. It
 897 * tries to do BIOS powermanagement based on the average system idle time.
 898 * Furthermore it calls the system default idle routine.
 899 */
 900
 901static int apm_cpu_idle(struct cpuidle_device *dev,
 902	struct cpuidle_driver *drv, int index)
 903{
 904	static int use_apm_idle; /* = 0 */
 905	static unsigned int last_jiffies; /* = 0 */
 906	static u64 last_stime; /* = 0 */
 907	u64 stime, utime;
 908
 909	int apm_idle_done = 0;
 910	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 911	unsigned int bucket;
 912
 913recalc:
 914	task_cputime(current, &utime, &stime);
 915	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 916		use_apm_idle = 0;
 917	} else if (jiffies_since_last_check > idle_period) {
 918		unsigned int idle_percentage;
 919
 920		idle_percentage = nsecs_to_jiffies(stime - last_stime);
 921		idle_percentage *= 100;
 922		idle_percentage /= jiffies_since_last_check;
 923		use_apm_idle = (idle_percentage > idle_threshold);
 924		if (apm_info.forbid_idle)
 925			use_apm_idle = 0;
 926	}
 927
 928	last_jiffies = jiffies;
 929	last_stime = stime;
 930
 931	bucket = IDLE_LEAKY_MAX;
 932
 933	while (!need_resched()) {
 934		if (use_apm_idle) {
 935			unsigned int t;
 936
 937			t = jiffies;
 938			switch (apm_do_idle()) {
 939			case 0:
 940				apm_idle_done = 1;
 941				if (t != jiffies) {
 942					if (bucket) {
 943						bucket = IDLE_LEAKY_MAX;
 944						continue;
 945					}
 946				} else if (bucket) {
 947					bucket--;
 948					continue;
 949				}
 950				break;
 951			case 1:
 952				apm_idle_done = 1;
 953				break;
 954			default: /* BIOS refused */
 955				break;
 956			}
 957		}
 958		default_idle();
 959		local_irq_disable();
 960		jiffies_since_last_check = jiffies - last_jiffies;
 961		if (jiffies_since_last_check > idle_period)
 962			goto recalc;
 963	}
 964
 965	if (apm_idle_done)
 966		apm_do_busy();
 967
 968	return index;
 969}
 970
 971/**
 972 *	apm_power_off	-	ask the BIOS to power off
 973 *
 974 *	Handle the power off sequence. This is the one piece of code we
 975 *	will execute even on SMP machines. In order to deal with BIOS
 976 *	bugs we support real mode APM BIOS power off calls. We also make
 977 *	the SMP call on CPU0 as some systems will only honour this call
 978 *	on their first cpu.
 979 */
 980
 981static void apm_power_off(void)
 982{
 983	/* Some bioses don't like being called from CPU != 0 */
 984	if (apm_info.realmode_power_off) {
 985		set_cpus_allowed_ptr(current, cpumask_of(0));
 986		machine_real_restart(MRR_APM);
 987	} else {
 988		(void)set_system_power_state(APM_STATE_OFF);
 989	}
 990}
 991
 992#ifdef CONFIG_APM_DO_ENABLE
 993
 994/**
 995 *	apm_enable_power_management - enable BIOS APM power management
 996 *	@enable: enable yes/no
 997 *
 998 *	Enable or disable the APM BIOS power services.
 999 */
1000
1001static int apm_enable_power_management(int enable)
1002{
1003	u32 eax;
1004	int err;
1005
1006	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1007		return APM_NOT_ENGAGED;
1008	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1009				 enable, &eax, &err))
1010		return err;
1011	if (enable)
1012		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1013	else
1014		apm_info.bios.flags |= APM_BIOS_DISABLED;
1015	return APM_SUCCESS;
1016}
1017#endif
1018
1019/**
1020 *	apm_get_power_status	-	get current power state
1021 *	@status: returned status
1022 *	@bat: battery info
1023 *	@life: estimated life
1024 *
1025 *	Obtain the current power status from the APM BIOS. We return a
1026 *	status which gives the rough battery status, and current power
1027 *	source. The bat value returned give an estimate as a percentage
1028 *	of life and a status value for the battery. The estimated life
1029 *	if reported is a lifetime in seconds/minutes at current power
1030 *	consumption.
1031 */
1032
1033static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1034{
1035	struct apm_bios_call call;
1036
1037	call.func = APM_FUNC_GET_STATUS;
1038	call.ebx = APM_DEVICE_ALL;
1039	call.ecx = 0;
1040
1041	if (apm_info.get_power_status_broken)
1042		return APM_32_UNSUPPORTED;
1043	if (apm_bios_call(&call)) {
1044		if (!call.err)
1045			return APM_NO_ERROR;
1046		return call.err;
1047	}
1048	*status = call.ebx;
1049	*bat = call.ecx;
1050	if (apm_info.get_power_status_swabinminutes) {
1051		*life = swab16((u16)call.edx);
1052		*life |= 0x8000;
1053	} else
1054		*life = call.edx;
1055	return APM_SUCCESS;
1056}
1057
1058#if 0
1059static int apm_get_battery_status(u_short which, u_short *status,
1060				  u_short *bat, u_short *life, u_short *nbat)
1061{
1062	u32 eax;
1063	u32 ebx;
1064	u32 ecx;
1065	u32 edx;
1066	u32 esi;
1067
1068	if (apm_info.connection_version < 0x0102) {
1069		/* pretend we only have one battery. */
1070		if (which != 1)
1071			return APM_BAD_DEVICE;
1072		*nbat = 1;
1073		return apm_get_power_status(status, bat, life);
1074	}
1075
1076	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1077			  &ebx, &ecx, &edx, &esi))
1078		return (eax >> 8) & 0xff;
1079	*status = ebx;
1080	*bat = ecx;
1081	*life = edx;
1082	*nbat = esi;
1083	return APM_SUCCESS;
1084}
1085#endif
1086
1087/**
1088 *	apm_engage_power_management	-	enable PM on a device
1089 *	@device: identity of device
1090 *	@enable: on/off
1091 *
1092 *	Activate or deactivate power management on either a specific device
1093 *	or the entire system (%APM_DEVICE_ALL).
1094 */
1095
1096static int apm_engage_power_management(u_short device, int enable)
1097{
1098	u32 eax;
1099	int err;
1100
1101	if ((enable == 0) && (device == APM_DEVICE_ALL)
1102	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1103		return APM_DISABLED;
1104	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1105				 &eax, &err))
1106		return err;
1107	if (device == APM_DEVICE_ALL) {
1108		if (enable)
1109			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1110		else
1111			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1112	}
1113	return APM_SUCCESS;
1114}
1115
1116#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1117
1118/**
1119 *	apm_console_blank	-	blank the display
1120 *	@blank: on/off
1121 *
1122 *	Attempt to blank the console, firstly by blanking just video device
1123 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1124 *	all video devices. Typically the BIOS will do laptop backlight and
1125 *	monitor powerdown for us.
1126 */
1127
1128static int apm_console_blank(int blank)
1129{
1130	int error = APM_NOT_ENGAGED; /* silence gcc */
1131	int i;
1132	u_short state;
1133	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1134
1135	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1136
1137	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1138		error = set_power_state(dev[i], state);
1139
1140		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1141			return 1;
1142
1143		if (error == APM_NOT_ENGAGED)
1144			break;
1145	}
1146
1147	if (error == APM_NOT_ENGAGED) {
1148		static int tried;
1149		int eng_error;
1150		if (tried++ == 0) {
1151			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1152			if (eng_error) {
1153				apm_error("set display", error);
1154				apm_error("engage interface", eng_error);
1155				return 0;
1156			} else
1157				return apm_console_blank(blank);
1158		}
1159	}
1160	apm_error("set display", error);
1161	return 0;
1162}
1163#endif
1164
1165static int queue_empty(struct apm_user *as)
1166{
1167	return as->event_head == as->event_tail;
1168}
1169
1170static apm_event_t get_queued_event(struct apm_user *as)
1171{
1172	if (++as->event_tail >= APM_MAX_EVENTS)
1173		as->event_tail = 0;
1174	return as->events[as->event_tail];
1175}
1176
1177static void queue_event(apm_event_t event, struct apm_user *sender)
1178{
1179	struct apm_user *as;
1180
1181	spin_lock(&user_list_lock);
1182	if (user_list == NULL)
1183		goto out;
1184	for (as = user_list; as != NULL; as = as->next) {
1185		if ((as == sender) || (!as->reader))
1186			continue;
1187		if (++as->event_head >= APM_MAX_EVENTS)
1188			as->event_head = 0;
1189
1190		if (as->event_head == as->event_tail) {
1191			static int notified;
1192
1193			if (notified++ == 0)
1194				pr_err("an event queue overflowed\n");
1195			if (++as->event_tail >= APM_MAX_EVENTS)
1196				as->event_tail = 0;
1197		}
1198		as->events[as->event_head] = event;
1199		if (!as->suser || !as->writer)
1200			continue;
1201		switch (event) {
1202		case APM_SYS_SUSPEND:
1203		case APM_USER_SUSPEND:
1204			as->suspends_pending++;
1205			suspends_pending++;
1206			break;
1207
1208		case APM_SYS_STANDBY:
1209		case APM_USER_STANDBY:
1210			as->standbys_pending++;
1211			standbys_pending++;
1212			break;
1213		}
1214	}
1215	wake_up_interruptible(&apm_waitqueue);
1216out:
1217	spin_unlock(&user_list_lock);
1218}
1219
1220static void reinit_timer(void)
1221{
1222#ifdef INIT_TIMER_AFTER_SUSPEND
1223	unsigned long flags;
1224
1225	raw_spin_lock_irqsave(&i8253_lock, flags);
1226	/* set the clock to HZ */
1227	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1228	udelay(10);
1229	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1230	udelay(10);
1231	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1232	udelay(10);
1233	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1234#endif
1235}
1236
1237static int suspend(int vetoable)
1238{
1239	int err;
1240	struct apm_user	*as;
1241
1242	dpm_suspend_start(PMSG_SUSPEND);
1243	dpm_suspend_end(PMSG_SUSPEND);
1244
1245	local_irq_disable();
1246	syscore_suspend();
1247
1248	local_irq_enable();
1249
1250	save_processor_state();
1251	err = set_system_power_state(APM_STATE_SUSPEND);
1252	ignore_normal_resume = 1;
1253	restore_processor_state();
1254
1255	local_irq_disable();
1256	reinit_timer();
1257
1258	if (err == APM_NO_ERROR)
1259		err = APM_SUCCESS;
1260	if (err != APM_SUCCESS)
1261		apm_error("suspend", err);
1262	err = (err == APM_SUCCESS) ? 0 : -EIO;
1263
1264	syscore_resume();
1265	local_irq_enable();
1266
1267	dpm_resume_start(PMSG_RESUME);
1268	dpm_resume_end(PMSG_RESUME);
1269
1270	queue_event(APM_NORMAL_RESUME, NULL);
1271	spin_lock(&user_list_lock);
1272	for (as = user_list; as != NULL; as = as->next) {
1273		as->suspend_wait = 0;
1274		as->suspend_result = err;
1275	}
1276	spin_unlock(&user_list_lock);
1277	wake_up_interruptible(&apm_suspend_waitqueue);
1278	return err;
1279}
1280
1281static void standby(void)
1282{
1283	int err;
1284
1285	dpm_suspend_end(PMSG_SUSPEND);
1286
1287	local_irq_disable();
1288	syscore_suspend();
1289	local_irq_enable();
1290
1291	err = set_system_power_state(APM_STATE_STANDBY);
1292	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1293		apm_error("standby", err);
1294
1295	local_irq_disable();
1296	syscore_resume();
1297	local_irq_enable();
1298
1299	dpm_resume_start(PMSG_RESUME);
1300}
1301
1302static apm_event_t get_event(void)
1303{
1304	int error;
1305	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1306	apm_eventinfo_t	info;
1307
1308	static int notified;
1309
1310	/* we don't use the eventinfo */
1311	error = apm_get_event(&event, &info);
1312	if (error == APM_SUCCESS)
1313		return event;
1314
1315	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1316		apm_error("get_event", error);
1317
1318	return 0;
1319}
1320
1321static void check_events(void)
1322{
1323	apm_event_t event;
1324	static unsigned long last_resume;
1325	static int ignore_bounce;
1326
1327	while ((event = get_event()) != 0) {
1328		if (debug) {
1329			if (event <= NR_APM_EVENT_NAME)
1330				printk(KERN_DEBUG "apm: received %s notify\n",
1331				       apm_event_name[event - 1]);
1332			else
1333				printk(KERN_DEBUG "apm: received unknown "
1334				       "event 0x%02x\n", event);
1335		}
1336		if (ignore_bounce
1337		    && (time_after(jiffies, last_resume + bounce_interval)))
1338			ignore_bounce = 0;
1339
1340		switch (event) {
1341		case APM_SYS_STANDBY:
1342		case APM_USER_STANDBY:
1343			queue_event(event, NULL);
1344			if (standbys_pending <= 0)
1345				standby();
1346			break;
1347
1348		case APM_USER_SUSPEND:
1349#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1350			if (apm_info.connection_version > 0x100)
1351				set_system_power_state(APM_STATE_REJECT);
1352			break;
1353#endif
1354		case APM_SYS_SUSPEND:
1355			if (ignore_bounce) {
1356				if (apm_info.connection_version > 0x100)
1357					set_system_power_state(APM_STATE_REJECT);
1358				break;
1359			}
1360			/*
1361			 * If we are already processing a SUSPEND,
1362			 * then further SUSPEND events from the BIOS
1363			 * will be ignored.  We also return here to
1364			 * cope with the fact that the Thinkpads keep
1365			 * sending a SUSPEND event until something else
1366			 * happens!
1367			 */
1368			if (ignore_sys_suspend)
1369				return;
1370			ignore_sys_suspend = 1;
1371			queue_event(event, NULL);
1372			if (suspends_pending <= 0)
1373				(void) suspend(1);
1374			break;
1375
1376		case APM_NORMAL_RESUME:
1377		case APM_CRITICAL_RESUME:
1378		case APM_STANDBY_RESUME:
1379			ignore_sys_suspend = 0;
1380			last_resume = jiffies;
1381			ignore_bounce = 1;
1382			if ((event != APM_NORMAL_RESUME)
1383			    || (ignore_normal_resume == 0)) {
1384				dpm_resume_end(PMSG_RESUME);
1385				queue_event(event, NULL);
1386			}
1387			ignore_normal_resume = 0;
1388			break;
1389
1390		case APM_CAPABILITY_CHANGE:
1391		case APM_LOW_BATTERY:
1392		case APM_POWER_STATUS_CHANGE:
1393			queue_event(event, NULL);
1394			/* If needed, notify drivers here */
1395			break;
1396
1397		case APM_UPDATE_TIME:
1398			break;
1399
1400		case APM_CRITICAL_SUSPEND:
1401			/*
1402			 * We are not allowed to reject a critical suspend.
1403			 */
1404			(void)suspend(0);
1405			break;
1406		}
1407	}
1408}
1409
1410static void apm_event_handler(void)
1411{
1412	static int pending_count = 4;
1413	int err;
1414
1415	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1416		if ((apm_info.connection_version > 0x100) &&
1417		    (pending_count-- <= 0)) {
1418			pending_count = 4;
1419			if (debug)
1420				printk(KERN_DEBUG "apm: setting state busy\n");
1421			err = set_system_power_state(APM_STATE_BUSY);
1422			if (err)
1423				apm_error("busy", err);
1424		}
1425	} else
1426		pending_count = 4;
1427	check_events();
1428}
1429
1430/*
1431 * This is the APM thread main loop.
1432 */
1433
1434static void apm_mainloop(void)
1435{
1436	DECLARE_WAITQUEUE(wait, current);
1437
1438	add_wait_queue(&apm_waitqueue, &wait);
1439	set_current_state(TASK_INTERRUPTIBLE);
1440	for (;;) {
1441		schedule_timeout(APM_CHECK_TIMEOUT);
1442		if (kthread_should_stop())
1443			break;
1444		/*
1445		 * Ok, check all events, check for idle (and mark us sleeping
1446		 * so as not to count towards the load average)..
1447		 */
1448		set_current_state(TASK_INTERRUPTIBLE);
1449		apm_event_handler();
1450	}
1451	remove_wait_queue(&apm_waitqueue, &wait);
1452}
1453
1454static int check_apm_user(struct apm_user *as, const char *func)
1455{
1456	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1457		pr_err("%s passed bad filp\n", func);
1458		return 1;
1459	}
1460	return 0;
1461}
1462
1463static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1464{
1465	struct apm_user *as;
1466	int i;
1467	apm_event_t event;
1468
1469	as = fp->private_data;
1470	if (check_apm_user(as, "read"))
1471		return -EIO;
1472	if ((int)count < sizeof(apm_event_t))
1473		return -EINVAL;
1474	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1475		return -EAGAIN;
1476	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1477	i = count;
1478	while ((i >= sizeof(event)) && !queue_empty(as)) {
1479		event = get_queued_event(as);
1480		if (copy_to_user(buf, &event, sizeof(event))) {
1481			if (i < count)
1482				break;
1483			return -EFAULT;
1484		}
1485		switch (event) {
1486		case APM_SYS_SUSPEND:
1487		case APM_USER_SUSPEND:
1488			as->suspends_read++;
1489			break;
1490
1491		case APM_SYS_STANDBY:
1492		case APM_USER_STANDBY:
1493			as->standbys_read++;
1494			break;
1495		}
1496		buf += sizeof(event);
1497		i -= sizeof(event);
1498	}
1499	if (i < count)
1500		return count - i;
1501	if (signal_pending(current))
1502		return -ERESTARTSYS;
1503	return 0;
1504}
1505
1506static __poll_t do_poll(struct file *fp, poll_table *wait)
1507{
1508	struct apm_user *as;
1509
1510	as = fp->private_data;
1511	if (check_apm_user(as, "poll"))
1512		return 0;
1513	poll_wait(fp, &apm_waitqueue, wait);
1514	if (!queue_empty(as))
1515		return EPOLLIN | EPOLLRDNORM;
1516	return 0;
1517}
1518
1519static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1520{
1521	struct apm_user *as;
1522	int ret;
1523
1524	as = filp->private_data;
1525	if (check_apm_user(as, "ioctl"))
1526		return -EIO;
1527	if (!as->suser || !as->writer)
1528		return -EPERM;
1529	switch (cmd) {
1530	case APM_IOC_STANDBY:
1531		mutex_lock(&apm_mutex);
1532		if (as->standbys_read > 0) {
1533			as->standbys_read--;
1534			as->standbys_pending--;
1535			standbys_pending--;
1536		} else
1537			queue_event(APM_USER_STANDBY, as);
1538		if (standbys_pending <= 0)
1539			standby();
1540		mutex_unlock(&apm_mutex);
1541		break;
1542	case APM_IOC_SUSPEND:
1543		mutex_lock(&apm_mutex);
1544		if (as->suspends_read > 0) {
1545			as->suspends_read--;
1546			as->suspends_pending--;
1547			suspends_pending--;
1548		} else
1549			queue_event(APM_USER_SUSPEND, as);
1550		if (suspends_pending <= 0) {
1551			ret = suspend(1);
1552			mutex_unlock(&apm_mutex);
1553		} else {
1554			as->suspend_wait = 1;
1555			mutex_unlock(&apm_mutex);
1556			wait_event_interruptible(apm_suspend_waitqueue,
1557					as->suspend_wait == 0);
1558			ret = as->suspend_result;
1559		}
1560		return ret;
1561	default:
1562		return -ENOTTY;
1563	}
1564	return 0;
1565}
1566
1567static int do_release(struct inode *inode, struct file *filp)
1568{
1569	struct apm_user *as;
1570
1571	as = filp->private_data;
1572	if (check_apm_user(as, "release"))
1573		return 0;
1574	filp->private_data = NULL;
1575	if (as->standbys_pending > 0) {
1576		standbys_pending -= as->standbys_pending;
1577		if (standbys_pending <= 0)
1578			standby();
1579	}
1580	if (as->suspends_pending > 0) {
1581		suspends_pending -= as->suspends_pending;
1582		if (suspends_pending <= 0)
1583			(void) suspend(1);
1584	}
1585	spin_lock(&user_list_lock);
1586	if (user_list == as)
1587		user_list = as->next;
1588	else {
1589		struct apm_user *as1;
1590
1591		for (as1 = user_list;
1592		     (as1 != NULL) && (as1->next != as);
1593		     as1 = as1->next)
1594			;
1595		if (as1 == NULL)
1596			pr_err("filp not in user list\n");
1597		else
1598			as1->next = as->next;
1599	}
1600	spin_unlock(&user_list_lock);
1601	kfree(as);
1602	return 0;
1603}
1604
1605static int do_open(struct inode *inode, struct file *filp)
1606{
1607	struct apm_user *as;
1608
1609	as = kmalloc(sizeof(*as), GFP_KERNEL);
1610	if (as == NULL)
1611		return -ENOMEM;
1612
1613	as->magic = APM_BIOS_MAGIC;
1614	as->event_tail = as->event_head = 0;
1615	as->suspends_pending = as->standbys_pending = 0;
1616	as->suspends_read = as->standbys_read = 0;
1617	/*
1618	 * XXX - this is a tiny bit broken, when we consider BSD
1619	 * process accounting. If the device is opened by root, we
1620	 * instantly flag that we used superuser privs. Who knows,
1621	 * we might close the device immediately without doing a
1622	 * privileged operation -- cevans
1623	 */
1624	as->suser = capable(CAP_SYS_ADMIN);
1625	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1626	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1627	spin_lock(&user_list_lock);
1628	as->next = user_list;
1629	user_list = as;
1630	spin_unlock(&user_list_lock);
1631	filp->private_data = as;
1632	return 0;
1633}
1634
1635#ifdef CONFIG_PROC_FS
1636static int proc_apm_show(struct seq_file *m, void *v)
1637{
1638	unsigned short	bx;
1639	unsigned short	cx;
1640	unsigned short	dx;
1641	int		error;
1642	unsigned short  ac_line_status = 0xff;
1643	unsigned short  battery_status = 0xff;
1644	unsigned short  battery_flag   = 0xff;
1645	int		percentage     = -1;
1646	int             time_units     = -1;
1647	char            *units         = "?";
1648
1649	if ((num_online_cpus() == 1) &&
1650	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1651		ac_line_status = (bx >> 8) & 0xff;
1652		battery_status = bx & 0xff;
1653		if ((cx & 0xff) != 0xff)
1654			percentage = cx & 0xff;
1655
1656		if (apm_info.connection_version > 0x100) {
1657			battery_flag = (cx >> 8) & 0xff;
1658			if (dx != 0xffff) {
1659				units = (dx & 0x8000) ? "min" : "sec";
1660				time_units = dx & 0x7fff;
1661			}
1662		}
1663	}
1664	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1665	   from the Get Power Status (0x0a) call unless otherwise noted.
1666
1667	   0) Linux driver version (this will change if format changes)
1668	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1669	   2) APM flags from APM Installation Check (0x00):
1670	      bit 0: APM_16_BIT_SUPPORT
1671	      bit 1: APM_32_BIT_SUPPORT
1672	      bit 2: APM_IDLE_SLOWS_CLOCK
1673	      bit 3: APM_BIOS_DISABLED
1674	      bit 4: APM_BIOS_DISENGAGED
1675	   3) AC line status
1676	      0x00: Off-line
1677	      0x01: On-line
1678	      0x02: On backup power (BIOS >= 1.1 only)
1679	      0xff: Unknown
1680	   4) Battery status
1681	      0x00: High
1682	      0x01: Low
1683	      0x02: Critical
1684	      0x03: Charging
1685	      0x04: Selected battery not present (BIOS >= 1.2 only)
1686	      0xff: Unknown
1687	   5) Battery flag
1688	      bit 0: High
1689	      bit 1: Low
1690	      bit 2: Critical
1691	      bit 3: Charging
1692	      bit 7: No system battery
1693	      0xff: Unknown
1694	   6) Remaining battery life (percentage of charge):
1695	      0-100: valid
1696	      -1: Unknown
1697	   7) Remaining battery life (time units):
1698	      Number of remaining minutes or seconds
1699	      -1: Unknown
1700	   8) min = minutes; sec = seconds */
1701
1702	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1703		   driver_version,
1704		   (apm_info.bios.version >> 8) & 0xff,
1705		   apm_info.bios.version & 0xff,
1706		   apm_info.bios.flags,
1707		   ac_line_status,
1708		   battery_status,
1709		   battery_flag,
1710		   percentage,
1711		   time_units,
1712		   units);
1713	return 0;
1714}
1715#endif
 
 
 
 
 
 
 
 
 
 
 
 
1716
1717static int apm(void *unused)
1718{
1719	unsigned short	bx;
1720	unsigned short	cx;
1721	unsigned short	dx;
1722	int		error;
1723	char 		*power_stat;
1724	char 		*bat_stat;
1725
1726	/* 2002/08/01 - WT
1727	 * This is to avoid random crashes at boot time during initialization
1728	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1729	 * Some bioses don't like being called from CPU != 0.
1730	 * Method suggested by Ingo Molnar.
1731	 */
1732	set_cpus_allowed_ptr(current, cpumask_of(0));
1733	BUG_ON(smp_processor_id() != 0);
1734
1735	if (apm_info.connection_version == 0) {
1736		apm_info.connection_version = apm_info.bios.version;
1737		if (apm_info.connection_version > 0x100) {
1738			/*
1739			 * We only support BIOSs up to version 1.2
1740			 */
1741			if (apm_info.connection_version > 0x0102)
1742				apm_info.connection_version = 0x0102;
1743			error = apm_driver_version(&apm_info.connection_version);
1744			if (error != APM_SUCCESS) {
1745				apm_error("driver version", error);
1746				/* Fall back to an APM 1.0 connection. */
1747				apm_info.connection_version = 0x100;
1748			}
1749		}
1750	}
1751
1752	if (debug)
1753		printk(KERN_INFO "apm: Connection version %d.%d\n",
1754			(apm_info.connection_version >> 8) & 0xff,
1755			apm_info.connection_version & 0xff);
1756
1757#ifdef CONFIG_APM_DO_ENABLE
1758	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1759		/*
1760		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1761		 * is booted with PM disabled but not in the docking station.
1762		 * Unfortunate ...
1763		 */
1764		error = apm_enable_power_management(1);
1765		if (error) {
1766			apm_error("enable power management", error);
1767			return -1;
1768		}
1769	}
1770#endif
1771
1772	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1773	    && (apm_info.connection_version > 0x0100)) {
1774		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1775		if (error) {
1776			apm_error("engage power management", error);
1777			return -1;
1778		}
1779	}
1780
1781	if (debug && (num_online_cpus() == 1 || smp)) {
1782		error = apm_get_power_status(&bx, &cx, &dx);
1783		if (error)
1784			printk(KERN_INFO "apm: power status not available\n");
1785		else {
1786			switch ((bx >> 8) & 0xff) {
1787			case 0:
1788				power_stat = "off line";
1789				break;
1790			case 1:
1791				power_stat = "on line";
1792				break;
1793			case 2:
1794				power_stat = "on backup power";
1795				break;
1796			default:
1797				power_stat = "unknown";
1798				break;
1799			}
1800			switch (bx & 0xff) {
1801			case 0:
1802				bat_stat = "high";
1803				break;
1804			case 1:
1805				bat_stat = "low";
1806				break;
1807			case 2:
1808				bat_stat = "critical";
1809				break;
1810			case 3:
1811				bat_stat = "charging";
1812				break;
1813			default:
1814				bat_stat = "unknown";
1815				break;
1816			}
1817			printk(KERN_INFO
1818			       "apm: AC %s, battery status %s, battery life ",
1819			       power_stat, bat_stat);
1820			if ((cx & 0xff) == 0xff)
1821				printk("unknown\n");
1822			else
1823				printk("%d%%\n", cx & 0xff);
1824			if (apm_info.connection_version > 0x100) {
1825				printk(KERN_INFO
1826				       "apm: battery flag 0x%02x, battery life ",
1827				       (cx >> 8) & 0xff);
1828				if (dx == 0xffff)
1829					printk("unknown\n");
1830				else
1831					printk("%d %s\n", dx & 0x7fff,
1832					       (dx & 0x8000) ?
1833					       "minutes" : "seconds");
1834			}
1835		}
1836	}
1837
1838	/* Install our power off handler.. */
1839	if (power_off)
1840		pm_power_off = apm_power_off;
1841
1842	if (num_online_cpus() == 1 || smp) {
1843#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1844		console_blank_hook = apm_console_blank;
1845#endif
1846		apm_mainloop();
1847#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1848		console_blank_hook = NULL;
1849#endif
1850	}
1851
1852	return 0;
1853}
1854
1855#ifndef MODULE
1856static int __init apm_setup(char *str)
1857{
1858	int invert;
1859
1860	while ((str != NULL) && (*str != '\0')) {
1861		if (strncmp(str, "off", 3) == 0)
1862			apm_disabled = 1;
1863		if (strncmp(str, "on", 2) == 0)
1864			apm_disabled = 0;
1865		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1866		    (strncmp(str, "bounce_interval=", 16) == 0))
1867			bounce_interval = simple_strtol(str + 16, NULL, 0);
1868		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1869		    (strncmp(str, "idle_threshold=", 15) == 0))
1870			idle_threshold = simple_strtol(str + 15, NULL, 0);
1871		if ((strncmp(str, "idle-period=", 12) == 0) ||
1872		    (strncmp(str, "idle_period=", 12) == 0))
1873			idle_period = simple_strtol(str + 12, NULL, 0);
1874		invert = (strncmp(str, "no-", 3) == 0) ||
1875			(strncmp(str, "no_", 3) == 0);
1876		if (invert)
1877			str += 3;
1878		if (strncmp(str, "debug", 5) == 0)
1879			debug = !invert;
1880		if ((strncmp(str, "power-off", 9) == 0) ||
1881		    (strncmp(str, "power_off", 9) == 0))
1882			power_off = !invert;
1883		if (strncmp(str, "smp", 3) == 0) {
1884			smp = !invert;
1885			idle_threshold = 100;
1886		}
1887		if ((strncmp(str, "allow-ints", 10) == 0) ||
1888		    (strncmp(str, "allow_ints", 10) == 0))
1889			apm_info.allow_ints = !invert;
1890		if ((strncmp(str, "broken-psr", 10) == 0) ||
1891		    (strncmp(str, "broken_psr", 10) == 0))
1892			apm_info.get_power_status_broken = !invert;
1893		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1894		    (strncmp(str, "realmode_power_off", 18) == 0))
1895			apm_info.realmode_power_off = !invert;
1896		str = strchr(str, ',');
1897		if (str != NULL)
1898			str += strspn(str, ", \t");
1899	}
1900	return 1;
1901}
1902
1903__setup("apm=", apm_setup);
1904#endif
1905
1906static const struct file_operations apm_bios_fops = {
1907	.owner		= THIS_MODULE,
1908	.read		= do_read,
1909	.poll		= do_poll,
1910	.unlocked_ioctl	= do_ioctl,
1911	.open		= do_open,
1912	.release	= do_release,
1913	.llseek		= noop_llseek,
1914};
1915
1916static struct miscdevice apm_device = {
1917	APM_MINOR_DEV,
1918	"apm_bios",
1919	&apm_bios_fops
1920};
1921
1922
1923/* Simple "print if true" callback */
1924static int __init print_if_true(const struct dmi_system_id *d)
1925{
1926	printk("%s\n", d->ident);
1927	return 0;
1928}
1929
1930/*
1931 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1932 * disabled before the suspend. Linux used to get terribly confused by that.
1933 */
1934static int __init broken_ps2_resume(const struct dmi_system_id *d)
1935{
1936	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1937	       "workaround hopefully not needed.\n", d->ident);
1938	return 0;
1939}
1940
1941/* Some bioses have a broken protected mode poweroff and need to use realmode */
1942static int __init set_realmode_power_off(const struct dmi_system_id *d)
1943{
1944	if (apm_info.realmode_power_off == 0) {
1945		apm_info.realmode_power_off = 1;
1946		printk(KERN_INFO "%s bios detected. "
1947		       "Using realmode poweroff only.\n", d->ident);
1948	}
1949	return 0;
1950}
1951
1952/* Some laptops require interrupts to be enabled during APM calls */
1953static int __init set_apm_ints(const struct dmi_system_id *d)
1954{
1955	if (apm_info.allow_ints == 0) {
1956		apm_info.allow_ints = 1;
1957		printk(KERN_INFO "%s machine detected. "
1958		       "Enabling interrupts during APM calls.\n", d->ident);
1959	}
1960	return 0;
1961}
1962
1963/* Some APM bioses corrupt memory or just plain do not work */
1964static int __init apm_is_horked(const struct dmi_system_id *d)
1965{
1966	if (apm_info.disabled == 0) {
1967		apm_info.disabled = 1;
1968		printk(KERN_INFO "%s machine detected. "
1969		       "Disabling APM.\n", d->ident);
1970	}
1971	return 0;
1972}
1973
1974static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1975{
1976	if (apm_info.disabled == 0) {
1977		apm_info.disabled = 1;
1978		printk(KERN_INFO "%s machine detected. "
1979		       "Disabling APM.\n", d->ident);
1980		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1981		printk(KERN_INFO "download from support.intel.com\n");
1982	}
1983	return 0;
1984}
1985
1986/* Some APM bioses hang on APM idle calls */
1987static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1988{
1989	if (apm_info.forbid_idle == 0) {
1990		apm_info.forbid_idle = 1;
1991		printk(KERN_INFO "%s machine detected. "
1992		       "Disabling APM idle calls.\n", d->ident);
1993	}
1994	return 0;
1995}
1996
1997/*
1998 *  Check for clue free BIOS implementations who use
1999 *  the following QA technique
2000 *
2001 *      [ Write BIOS Code ]<------
2002 *               |                ^
2003 *      < Does it Compile >----N--
2004 *               |Y               ^
2005 *	< Does it Boot Win98 >-N--
2006 *               |Y
2007 *           [Ship It]
2008 *
2009 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2010 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2011 */
2012static int __init broken_apm_power(const struct dmi_system_id *d)
2013{
2014	apm_info.get_power_status_broken = 1;
2015	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2016	       "disabling power status reporting.\n");
2017	return 0;
2018}
2019
2020/*
2021 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2022 * have this problem).
2023 */
2024static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2025{
2026	apm_info.get_power_status_swabinminutes = 1;
2027	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2028	       "in minutes and wrong byte order.\n");
2029	return 0;
2030}
2031
2032static const struct dmi_system_id apm_dmi_table[] __initconst = {
2033	{
2034		print_if_true,
2035		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2036		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2037			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2038	},
2039	{	/* Handle problems with APM on the C600 */
2040		broken_ps2_resume, "Dell Latitude C600",
2041		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2042			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2043	},
2044	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2045		set_apm_ints, "Dell Latitude",
2046		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2047			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2048	},
2049	{	/* APM crashes */
2050		apm_is_horked, "Dell Inspiron 2500",
2051		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2052			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2053			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2054			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2055	},
2056	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2057		set_apm_ints, "Dell Inspiron", {
2058			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2059			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2060	},
2061	{	/* Handle problems with APM on Inspiron 5000e */
2062		broken_apm_power, "Dell Inspiron 5000e",
2063		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2064			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2065			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2066	},
2067	{	/* Handle problems with APM on Inspiron 2500 */
2068		broken_apm_power, "Dell Inspiron 2500",
2069		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2070			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2071			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2072	},
2073	{	/* APM crashes */
2074		apm_is_horked, "Dell Dimension 4100",
2075		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2076			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2077			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2078			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2079	},
2080	{	/* Allow interrupts during suspend on Compaq Laptops*/
2081		set_apm_ints, "Compaq 12XL125",
2082		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2083			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2084			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2085			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2086	},
2087	{	/* Allow interrupts during APM or the clock goes slow */
2088		set_apm_ints, "ASUSTeK",
2089		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2090			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2091	},
2092	{	/* APM blows on shutdown */
2093		apm_is_horked, "ABIT KX7-333[R]",
2094		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2095			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2096	},
2097	{	/* APM crashes */
2098		apm_is_horked, "Trigem Delhi3",
2099		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2100			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2101	},
2102	{	/* APM crashes */
2103		apm_is_horked, "Fujitsu-Siemens",
2104		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2105			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2106	},
2107	{	/* APM crashes */
2108		apm_is_horked_d850md, "Intel D850MD",
2109		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2110			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2111	},
2112	{	/* APM crashes */
2113		apm_is_horked, "Intel D810EMO",
2114		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2115			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2116	},
2117	{	/* APM crashes */
2118		apm_is_horked, "Dell XPS-Z",
2119		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2120			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2121			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2122	},
2123	{	/* APM crashes */
2124		apm_is_horked, "Sharp PC-PJ/AX",
2125		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2126			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2127			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2128			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2129	},
2130	{	/* APM crashes */
2131		apm_is_horked, "Dell Inspiron 2500",
2132		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2133			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2134			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2135			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2136	},
2137	{	/* APM idle hangs */
2138		apm_likes_to_melt, "Jabil AMD",
2139		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2140			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2141	},
2142	{	/* APM idle hangs */
2143		apm_likes_to_melt, "AMI Bios",
2144		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2145			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2146	},
2147	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2148		swab_apm_power_in_minutes, "Sony VAIO",
2149		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2150			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2151			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2152	},
2153	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2154		swab_apm_power_in_minutes, "Sony VAIO",
2155		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2156			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2157			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2158	},
2159	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2160		swab_apm_power_in_minutes, "Sony VAIO",
2161		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2162			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2163			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2164	},
2165	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2166		swab_apm_power_in_minutes, "Sony VAIO",
2167		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2168			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2169			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2170	},
2171	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2172		swab_apm_power_in_minutes, "Sony VAIO",
2173		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2174			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2175			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2176	},
2177	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2178		swab_apm_power_in_minutes, "Sony VAIO",
2179		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2180			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2181			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2182	},
2183	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2184		swab_apm_power_in_minutes, "Sony VAIO",
2185		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2186			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2187			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2188	},
2189	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2190		swab_apm_power_in_minutes, "Sony VAIO",
2191		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2192			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2193			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2194	},
2195	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2196		swab_apm_power_in_minutes, "Sony VAIO",
2197		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2198			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2199			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2200	},
2201	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2202		swab_apm_power_in_minutes, "Sony VAIO",
2203		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2204			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2205			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2206	},
2207
2208	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2209		swab_apm_power_in_minutes, "Sony VAIO",
2210		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2211			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2212			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2213	},
2214	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2215		swab_apm_power_in_minutes, "Sony VAIO",
2216		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2217			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2218			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2219	},
2220	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2221		swab_apm_power_in_minutes, "Sony VAIO",
2222		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2223			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2224			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2225	},
2226	{	/* broken PM poweroff bios */
2227		set_realmode_power_off, "Award Software v4.60 PGMA",
2228		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2229			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2230			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2231	},
2232
2233	/* Generic per vendor APM settings  */
2234
2235	{	/* Allow interrupts during suspend on IBM laptops */
2236		set_apm_ints, "IBM",
2237		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2238	},
2239
2240	{ }
2241};
2242
2243/*
2244 * Just start the APM thread. We do NOT want to do APM BIOS
2245 * calls from anything but the APM thread, if for no other reason
2246 * than the fact that we don't trust the APM BIOS. This way,
2247 * most common APM BIOS problems that lead to protection errors
2248 * etc will have at least some level of being contained...
2249 *
2250 * In short, if something bad happens, at least we have a choice
2251 * of just killing the apm thread..
2252 */
2253static int __init apm_init(void)
2254{
2255	struct desc_struct *gdt;
2256	int err;
2257
2258	dmi_check_system(apm_dmi_table);
2259
2260	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2261		printk(KERN_INFO "apm: BIOS not found.\n");
2262		return -ENODEV;
2263	}
2264	printk(KERN_INFO
2265	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2266	       ((apm_info.bios.version >> 8) & 0xff),
2267	       (apm_info.bios.version & 0xff),
2268	       apm_info.bios.flags,
2269	       driver_version);
2270	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2271		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2272		return -ENODEV;
2273	}
2274
2275	if (allow_ints)
2276		apm_info.allow_ints = 1;
2277	if (broken_psr)
2278		apm_info.get_power_status_broken = 1;
2279	if (realmode_power_off)
2280		apm_info.realmode_power_off = 1;
2281	/* User can override, but default is to trust DMI */
2282	if (apm_disabled != -1)
2283		apm_info.disabled = apm_disabled;
2284
2285	/*
2286	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2287	 * but is reportedly a 1.0 BIOS.
2288	 */
2289	if (apm_info.bios.version == 0x001)
2290		apm_info.bios.version = 0x100;
2291
2292	/* BIOS < 1.2 doesn't set cseg_16_len */
2293	if (apm_info.bios.version < 0x102)
2294		apm_info.bios.cseg_16_len = 0; /* 64k */
2295
2296	if (debug) {
2297		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2298			apm_info.bios.cseg, apm_info.bios.offset,
2299			apm_info.bios.cseg_16, apm_info.bios.dseg);
2300		if (apm_info.bios.version > 0x100)
2301			printk(" cseg len %x, dseg len %x",
2302				apm_info.bios.cseg_len,
2303				apm_info.bios.dseg_len);
2304		if (apm_info.bios.version > 0x101)
2305			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2306		printk("\n");
2307	}
2308
2309	if (apm_info.disabled) {
2310		pr_notice("disabled on user request.\n");
2311		return -ENODEV;
2312	}
2313	if ((num_online_cpus() > 1) && !power_off && !smp) {
2314		pr_notice("disabled - APM is not SMP safe.\n");
2315		apm_info.disabled = 1;
2316		return -ENODEV;
2317	}
2318	if (!acpi_disabled) {
2319		pr_notice("overridden by ACPI.\n");
2320		apm_info.disabled = 1;
2321		return -ENODEV;
2322	}
2323
2324	/*
2325	 * Set up the long jump entry point to the APM BIOS, which is called
2326	 * from inline assembly.
2327	 */
2328	apm_bios_entry.offset = apm_info.bios.offset;
2329	apm_bios_entry.segment = APM_CS;
2330
2331	/*
2332	 * The APM 1.1 BIOS is supposed to provide limit information that it
2333	 * recognizes.  Many machines do this correctly, but many others do
2334	 * not restrict themselves to their claimed limit.  When this happens,
2335	 * they will cause a segmentation violation in the kernel at boot time.
2336	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2337	 *
2338	 * Note we only set APM segments on CPU zero, since we pin the APM
2339	 * code to that CPU.
2340	 */
2341	gdt = get_cpu_gdt_rw(0);
2342	set_desc_base(&gdt[APM_CS >> 3],
2343		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2344	set_desc_base(&gdt[APM_CS_16 >> 3],
2345		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2346	set_desc_base(&gdt[APM_DS >> 3],
2347		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2348
2349	proc_create_single("apm", 0, NULL, proc_apm_show);
2350
2351	kapmd_task = kthread_create(apm, NULL, "kapmd");
2352	if (IS_ERR(kapmd_task)) {
2353		pr_err("disabled - Unable to start kernel thread\n");
2354		err = PTR_ERR(kapmd_task);
2355		kapmd_task = NULL;
2356		remove_proc_entry("apm", NULL);
2357		return err;
2358	}
2359	wake_up_process(kapmd_task);
2360
2361	if (num_online_cpus() > 1 && !smp) {
2362		printk(KERN_NOTICE
2363		       "apm: disabled - APM is not SMP safe (power off active).\n");
2364		return 0;
2365	}
2366
2367	/*
2368	 * Note we don't actually care if the misc_device cannot be registered.
2369	 * this driver can do its job without it, even if userspace can't
2370	 * control it.  just log the error
2371	 */
2372	if (misc_register(&apm_device))
2373		printk(KERN_WARNING "apm: Could not register misc device.\n");
2374
2375	if (HZ != 100)
2376		idle_period = (idle_period * HZ) / 100;
2377	if (idle_threshold < 100) {
2378		cpuidle_poll_state_init(&apm_idle_driver);
2379		if (!cpuidle_register_driver(&apm_idle_driver))
2380			if (cpuidle_register_device(&apm_cpuidle_device))
2381				cpuidle_unregister_driver(&apm_idle_driver);
2382	}
2383
2384	return 0;
2385}
2386
2387static void __exit apm_exit(void)
2388{
2389	int error;
2390
2391	cpuidle_unregister_device(&apm_cpuidle_device);
2392	cpuidle_unregister_driver(&apm_idle_driver);
2393
2394	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2395	    && (apm_info.connection_version > 0x0100)) {
2396		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2397		if (error)
2398			apm_error("disengage power management", error);
2399	}
2400	misc_deregister(&apm_device);
2401	remove_proc_entry("apm", NULL);
2402	if (power_off)
2403		pm_power_off = NULL;
2404	if (kapmd_task) {
2405		kthread_stop(kapmd_task);
2406		kapmd_task = NULL;
2407	}
2408}
2409
2410module_init(apm_init);
2411module_exit(apm_exit);
2412
2413MODULE_AUTHOR("Stephen Rothwell");
2414MODULE_DESCRIPTION("Advanced Power Management");
2415MODULE_LICENSE("GPL");
2416module_param(debug, bool, 0644);
2417MODULE_PARM_DESC(debug, "Enable debug mode");
2418module_param(power_off, bool, 0444);
2419MODULE_PARM_DESC(power_off, "Enable power off");
2420module_param(bounce_interval, int, 0444);
2421MODULE_PARM_DESC(bounce_interval,
2422		"Set the number of ticks to ignore suspend bounces");
2423module_param(allow_ints, bool, 0444);
2424MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2425module_param(broken_psr, bool, 0444);
2426MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2427module_param(realmode_power_off, bool, 0444);
2428MODULE_PARM_DESC(realmode_power_off,
2429		"Switch to real mode before powering off");
2430module_param(idle_threshold, int, 0444);
2431MODULE_PARM_DESC(idle_threshold,
2432	"System idle percentage above which to make APM BIOS idle calls");
2433module_param(idle_period, int, 0444);
2434MODULE_PARM_DESC(idle_period,
2435	"Period (in sec/100) over which to calculate the idle percentage");
2436module_param(smp, bool, 0444);
2437MODULE_PARM_DESC(smp,
2438	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2439MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);