Linux Audio

Check our new training course

Loading...
v5.4
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* -*- linux-c -*-
   3 * APM BIOS driver for Linux
   4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   5 *
   6 * Initial development of this driver was funded by NEC Australia P/L
   7 *	and NEC Corporation
   8 *
   9 * October 1995, Rik Faith (faith@cs.unc.edu):
  10 *    Minor enhancements and updates (to the patch set) for 1.3.x
  11 *    Documentation
  12 * January 1996, Rik Faith (faith@cs.unc.edu):
  13 *    Make /proc/apm easy to format (bump driver version)
  14 * March 1996, Rik Faith (faith@cs.unc.edu):
  15 *    Prohibit APM BIOS calls unless apm_enabled.
  16 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  18 *    Version 1.0 and 1.1
  19 * May 1996, Version 1.2
  20 * Feb 1998, Version 1.3
  21 * Feb 1998, Version 1.4
  22 * Aug 1998, Version 1.5
  23 * Sep 1998, Version 1.6
  24 * Nov 1998, Version 1.7
  25 * Jan 1999, Version 1.8
  26 * Jan 1999, Version 1.9
  27 * Oct 1999, Version 1.10
  28 * Nov 1999, Version 1.11
  29 * Jan 2000, Version 1.12
  30 * Feb 2000, Version 1.13
  31 * Nov 2000, Version 1.14
  32 * Oct 2001, Version 1.15
  33 * Jan 2002, Version 1.16
  34 * Oct 2002, Version 1.16ac
  35 *
  36 * History:
  37 *    0.6b: first version in official kernel, Linux 1.3.46
  38 *    0.7: changed /proc/apm format, Linux 1.3.58
  39 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  40 *    0.9: only call bios if bios is present, Linux 1.3.72
  41 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  42 *         Linux 1.3.85
  43 *    1.1: support user-space standby and suspend, power off after system
  44 *         halted, Linux 1.3.98
  45 *    1.2: When resetting RTC after resume, take care so that the time
  46 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  47 *         <jtoth@princeton.edu>); improve interaction between
  48 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  49 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  50 *	   levels to the printk calls. APM is not defined for SMP machines.
  51 *         The new replacement for it is, but Linux doesn't yet support this.
  52 *         Alan Cox Linux 2.1.55
  53 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  54 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  55 *         Dean Gaudet <dgaudet@arctic.org>.
  56 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  57 *    1.5: Fix segment register reloading (in case of bad segments saved
  58 *         across BIOS call).
  59 *         Stephen Rothwell
  60 *    1.6: Cope with compiler/assembler differences.
  61 *         Only try to turn off the first display device.
  62 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  63 *                   <echter@informatik.uni-rostock.de>
  64 *         Stephen Rothwell
  65 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  66 *         to reflect current state of APM BIOS.
  67 *         Chris Rankin <rankinc@bellsouth.net>
  68 *         Reset interrupt 0 timer to 100Hz after suspend
  69 *         Chad Miller <cmiller@surfsouth.com>
  70 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  71 *         Richard Gooch <rgooch@atnf.csiro.au>
  72 *         Allow boot time disabling of APM
  73 *         Make boot messages far less verbose by default
  74 *         Make asm safer
  75 *         Stephen Rothwell
  76 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  77 *         Richard Gooch <rgooch@atnf.csiro.au>
  78 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  79 *         remove dependency on CONFIG_PROC_FS
  80 *         Stephen Rothwell
  81 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  82 *         Try to cope with BIOS's that need to have all display
  83 *         devices blanked and not just the first one.
  84 *         Ross Paterson <ross@soi.city.ac.uk>
  85 *         Fix segment limit setting it has always been wrong as
  86 *         the segments needed to have byte granularity.
  87 *         Mark a few things __init.
  88 *         Add hack to allow power off of SMP systems by popular request.
  89 *         Use CONFIG_SMP instead of __SMP__
  90 *         Ignore BOUNCES for three seconds.
  91 *         Stephen Rothwell
  92 *   1.10: Fix for Thinkpad return code.
  93 *         Merge 2.2 and 2.3 drivers.
  94 *         Remove APM dependencies in arch/i386/kernel/process.c
  95 *         Remove APM dependencies in drivers/char/sysrq.c
  96 *         Reset time across standby.
  97 *         Allow more inititialisation on SMP.
  98 *         Remove CONFIG_APM_POWER_OFF and make it boot time
  99 *         configurable (default on).
 100 *         Make debug only a boot time parameter (remove APM_DEBUG).
 101 *         Try to blank all devices on any error.
 102 *   1.11: Remove APM dependencies in drivers/char/console.c
 103 *         Check nr_running to detect if we are idle (from
 104 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 105 *         Fix for bioses that don't zero the top part of the
 106 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 107 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 108 *         Real mode power off patch (Walter Hofmann
 109 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 110 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 111 *         the code away anyway (smp_num_cpus == 1 in UP)
 112 *         noted by Artur Skawina <skawina@geocities.com>.
 113 *         Make power off under SMP work again.
 114 *         Fix thinko with initial engaging of BIOS.
 115 *         Make sure power off only happens on CPU 0
 116 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 117 *         Do error notification to user mode if BIOS calls fail.
 118 *         Move entrypoint offset fix to ...boot/setup.S
 119 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 120 *         Remove smp-power-off. SMP users must now specify
 121 *         "apm=power-off" on the kernel command line. Suggested
 122 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 123 *         <alan@lxorguk.ukuu.org.uk>.
 124 *         Register the /proc/apm entry even on SMP so that
 125 *         scripts that check for it before doing power off
 126 *         work (Jim Avera <jima@hal.com>).
 127 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 128 *         <andy_henroid@yahoo.com>).
 129 *         Modularize the code.
 130 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 131 *         is now the way life works).
 132 *         Fix thinko in suspend() (wrong return).
 133 *         Notify drivers on critical suspend.
 134 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 135 *         modified by sfr).
 136 *         Disable interrupts while we are suspended (Andy Henroid
 137 *         <andy_henroid@yahoo.com> fixed by sfr).
 138 *         Make power off work on SMP again (Tony Hoyle
 139 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 140 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 141 *         interval is now configurable.
 142 *   1.14: Make connection version persist across module unload/load.
 143 *         Enable and engage power management earlier.
 144 *         Disengage power management on module unload.
 145 *         Changed to use the sysrq-register hack for registering the
 146 *         power off function called by magic sysrq based upon discussions
 147 *         in irc://irc.openprojects.net/#kernelnewbies
 148 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 149 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 150 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 151 *         Work around byte swap bug in one of the Vaio's BIOS's
 152 *         (Marc Boucher <marc@mbsi.ca>).
 153 *         Exposed the disable flag to dmi so that we can handle known
 154 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 155 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 156 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 157 *         If an APM idle fails log it and idle sensibly
 158 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 159 *         Don't expect replies from clients who open the device O_RDONLY.
 160 *         (Idea from Thomas Hood)
 161 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 162 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 163 *         Notify listeners of standby or suspend events before notifying
 164 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 165 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 166 *         Ignore first resume after we generate our own resume event
 167 *         after a suspend (Thomas Hood)
 168 *         Daemonize now gets rid of our controlling terminal (sfr).
 169 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 170 *         idle_threshold (sfr).
 171 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 172 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 173 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 174 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 175 *
 176 * APM 1.1 Reference:
 177 *
 178 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 179 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 180 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 181 *
 182 * [This document is available free from Intel by calling 800.628.8686 (fax
 183 * 916.356.6100) or 800.548.4725; or from
 184 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 185 * available from Microsoft by calling 206.882.8080.]
 186 *
 187 * APM 1.2 Reference:
 188 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 189 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 190 *
 191 * [This document is available from Microsoft at:
 192 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 193 */
 194
 195#define pr_fmt(fmt) "apm: " fmt
 196
 197#include <linux/module.h>
 198
 199#include <linux/poll.h>
 200#include <linux/types.h>
 201#include <linux/stddef.h>
 202#include <linux/timer.h>
 203#include <linux/fcntl.h>
 204#include <linux/slab.h>
 205#include <linux/stat.h>
 206#include <linux/proc_fs.h>
 207#include <linux/seq_file.h>
 208#include <linux/miscdevice.h>
 209#include <linux/apm_bios.h>
 210#include <linux/init.h>
 211#include <linux/time.h>
 212#include <linux/sched/signal.h>
 213#include <linux/sched/cputime.h>
 214#include <linux/pm.h>
 215#include <linux/capability.h>
 216#include <linux/device.h>
 217#include <linux/kernel.h>
 218#include <linux/freezer.h>
 219#include <linux/smp.h>
 220#include <linux/dmi.h>
 221#include <linux/suspend.h>
 222#include <linux/kthread.h>
 223#include <linux/jiffies.h>
 224#include <linux/acpi.h>
 225#include <linux/syscore_ops.h>
 226#include <linux/i8253.h>
 227#include <linux/cpuidle.h>
 228
 229#include <linux/uaccess.h>
 230#include <asm/desc.h>
 231#include <asm/olpc.h>
 232#include <asm/paravirt.h>
 233#include <asm/reboot.h>
 234#include <asm/nospec-branch.h>
 
 235
 236#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 237extern int (*console_blank_hook)(int);
 238#endif
 239
 240/*
 241 * The apm_bios device is one of the misc char devices.
 242 * This is its minor number.
 243 */
 244#define	APM_MINOR_DEV	134
 245
 246/*
 247 * Various options can be changed at boot time as follows:
 248 * (We allow underscores for compatibility with the modules code)
 249 *	apm=on/off			enable/disable APM
 250 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 251 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 252 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 253 *	    					powering off
 254 *	    [no-]debug			log some debugging messages
 255 *	    [no-]power[-_]off		power off on shutdown
 256 *	    [no-]smp			Use apm even on an SMP box
 257 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 258 *	    				bounces
 259 *          idle[-_]threshold=<n>       System idle percentage above which to
 260 *                                      make APM BIOS idle calls. Set it to
 261 *                                      100 to disable.
 262 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 263 *                                      which the idle percentage is
 264 *                                      calculated.
 265 */
 266
 267/* KNOWN PROBLEM MACHINES:
 268 *
 269 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 270 *                         [Confirmed by TI representative]
 271 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 272 *                    [Confirmed by BIOS disassembly]
 273 *                    [This may work now ...]
 274 * P: Toshiba 1950S: battery life information only gets updated after resume
 275 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 276 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 277 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 278 * 	Neale Banks <neale@lowendale.com.au> December 2000
 279 *
 280 * Legend: U = unusable with APM patches
 281 *         P = partially usable with APM patches
 282 */
 283
 284/*
 285 * Define as 1 to make the driver always call the APM BIOS busy
 286 * routine even if the clock was not reported as slowed by the
 287 * idle routine.  Otherwise, define as 0.
 288 */
 289#define ALWAYS_CALL_BUSY   1
 290
 291/*
 292 * Define to make the APM BIOS calls zero all data segment registers (so
 293 * that an incorrect BIOS implementation will cause a kernel panic if it
 294 * tries to write to arbitrary memory).
 295 */
 296#define APM_ZERO_SEGS
 297
 298#include <asm/apm.h>
 299
 300/*
 301 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 302 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 303 * David Chen <chen@ctpa04.mit.edu>
 304 */
 305#undef INIT_TIMER_AFTER_SUSPEND
 306
 307#ifdef INIT_TIMER_AFTER_SUSPEND
 308#include <linux/timex.h>
 309#include <asm/io.h>
 310#include <linux/delay.h>
 311#endif
 312
 313/*
 314 * Need to poll the APM BIOS every second
 315 */
 316#define APM_CHECK_TIMEOUT	(HZ)
 317
 318/*
 319 * Ignore suspend events for this amount of time after a resume
 320 */
 321#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 322
 323/*
 324 * Maximum number of events stored
 325 */
 326#define APM_MAX_EVENTS		20
 327
 328/*
 329 * The per-file APM data
 330 */
 331struct apm_user {
 332	int		magic;
 333	struct apm_user *next;
 334	unsigned int	suser: 1;
 335	unsigned int	writer: 1;
 336	unsigned int	reader: 1;
 337	unsigned int	suspend_wait: 1;
 338	int		suspend_result;
 339	int		suspends_pending;
 340	int		standbys_pending;
 341	int		suspends_read;
 342	int		standbys_read;
 343	int		event_head;
 344	int		event_tail;
 345	apm_event_t	events[APM_MAX_EVENTS];
 346};
 347
 348/*
 349 * The magic number in apm_user
 350 */
 351#define APM_BIOS_MAGIC		0x4101
 352
 353/*
 354 * idle percentage above which bios idle calls are done
 355 */
 356#ifdef CONFIG_APM_CPU_IDLE
 357#define DEFAULT_IDLE_THRESHOLD	95
 358#else
 359#define DEFAULT_IDLE_THRESHOLD	100
 360#endif
 361#define DEFAULT_IDLE_PERIOD	(100 / 3)
 362
 363static int apm_cpu_idle(struct cpuidle_device *dev,
 364			struct cpuidle_driver *drv, int index);
 365
 366static struct cpuidle_driver apm_idle_driver = {
 367	.name = "apm_idle",
 368	.owner = THIS_MODULE,
 369	.states = {
 370		{ /* entry 0 is for polling */ },
 371		{ /* entry 1 is for APM idle */
 372			.name = "APM",
 373			.desc = "APM idle",
 374			.exit_latency = 250,	/* WAG */
 375			.target_residency = 500,	/* WAG */
 376			.enter = &apm_cpu_idle
 377		},
 378	},
 379	.state_count = 2,
 380};
 381
 382static struct cpuidle_device apm_cpuidle_device;
 383
 384/*
 385 * Local variables
 386 */
 387__visible struct {
 388	unsigned long	offset;
 389	unsigned short	segment;
 390} apm_bios_entry;
 391static int clock_slowed;
 392static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 393static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 394static int suspends_pending;
 395static int standbys_pending;
 396static int ignore_sys_suspend;
 397static int ignore_normal_resume;
 398static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 399
 400static bool debug __read_mostly;
 401static bool smp __read_mostly;
 402static int apm_disabled = -1;
 403#ifdef CONFIG_SMP
 404static bool power_off;
 405#else
 406static bool power_off = 1;
 407#endif
 408static bool realmode_power_off;
 409#ifdef CONFIG_APM_ALLOW_INTS
 410static bool allow_ints = 1;
 411#else
 412static bool allow_ints;
 413#endif
 414static bool broken_psr;
 415
 416static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 417static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 418static struct apm_user *user_list;
 419static DEFINE_SPINLOCK(user_list_lock);
 420static DEFINE_MUTEX(apm_mutex);
 421
 422/*
 423 * Set up a segment that references the real mode segment 0x40
 424 * that extends up to the end of page zero (that we have reserved).
 425 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 426 * even though they are called in protected mode.
 427 */
 428static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
 429			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 430
 431static const char driver_version[] = "1.16ac";	/* no spaces */
 432
 433static struct task_struct *kapmd_task;
 434
 435/*
 436 *	APM event names taken from the APM 1.2 specification. These are
 437 *	the message codes that the BIOS uses to tell us about events
 438 */
 439static const char * const apm_event_name[] = {
 440	"system standby",
 441	"system suspend",
 442	"normal resume",
 443	"critical resume",
 444	"low battery",
 445	"power status change",
 446	"update time",
 447	"critical suspend",
 448	"user standby",
 449	"user suspend",
 450	"system standby resume",
 451	"capabilities change"
 452};
 453#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 454
 455typedef struct lookup_t {
 456	int	key;
 457	char 	*msg;
 458} lookup_t;
 459
 460/*
 461 *	The BIOS returns a set of standard error codes in AX when the
 462 *	carry flag is set.
 463 */
 464
 465static const lookup_t error_table[] = {
 466/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 467	{ APM_DISABLED,		"Power management disabled" },
 468	{ APM_CONNECTED,	"Real mode interface already connected" },
 469	{ APM_NOT_CONNECTED,	"Interface not connected" },
 470	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 471/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 472	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 473	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 474	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 475	{ APM_BAD_PARAM,	"Parameter out of range" },
 476	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 477	{ APM_BAD_FUNCTION,     "Function not supported" },
 478	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 479	{ APM_BAD_STATE,	"Unable to enter requested state" },
 480/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 481	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 482	{ APM_NOT_PRESENT,	"No APM present" }
 483};
 484#define ERROR_COUNT	ARRAY_SIZE(error_table)
 485
 486/**
 487 *	apm_error	-	display an APM error
 488 *	@str: information string
 489 *	@err: APM BIOS return code
 490 *
 491 *	Write a meaningful log entry to the kernel log in the event of
 492 *	an APM error.  Note that this also handles (negative) kernel errors.
 493 */
 494
 495static void apm_error(char *str, int err)
 496{
 497	int i;
 498
 499	for (i = 0; i < ERROR_COUNT; i++)
 500		if (error_table[i].key == err)
 501			break;
 502	if (i < ERROR_COUNT)
 503		pr_notice("%s: %s\n", str, error_table[i].msg);
 504	else if (err < 0)
 505		pr_notice("%s: linux error code %i\n", str, err);
 506	else
 507		pr_notice("%s: unknown error code %#2.2x\n",
 508		       str, err);
 509}
 510
 511/*
 512 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 513 * apm_info.allow_ints, we are being really paranoid here!  Not only
 514 * are interrupts disabled, but all the segment registers (except SS)
 515 * are saved and zeroed this means that if the BIOS tries to reference
 516 * any data without explicitly loading the segment registers, the kernel
 517 * will fault immediately rather than have some unforeseen circumstances
 518 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 519 * this depends on CS referring to the same physical memory as DS so that
 520 * DS can be zeroed before the call. Unfortunately, we can't do anything
 521 * about the stack segment/pointer.  Also, we tell the compiler that
 522 * everything could change.
 523 *
 524 * Also, we KNOW that for the non error case of apm_bios_call, there
 525 * is no useful data returned in the low order 8 bits of eax.
 526 */
 527
 528static inline unsigned long __apm_irq_save(void)
 529{
 530	unsigned long flags;
 531	local_save_flags(flags);
 532	if (apm_info.allow_ints) {
 533		if (irqs_disabled_flags(flags))
 534			local_irq_enable();
 535	} else
 536		local_irq_disable();
 537
 538	return flags;
 539}
 540
 541#define apm_irq_save(flags) \
 542	do { flags = __apm_irq_save(); } while (0)
 543
 544static inline void apm_irq_restore(unsigned long flags)
 545{
 546	if (irqs_disabled_flags(flags))
 547		local_irq_disable();
 548	else if (irqs_disabled())
 549		local_irq_enable();
 550}
 551
 552#ifdef APM_ZERO_SEGS
 553#	define APM_DECL_SEGS \
 554		unsigned int saved_fs; unsigned int saved_gs;
 555#	define APM_DO_SAVE_SEGS \
 556		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 557#	define APM_DO_RESTORE_SEGS \
 558		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 559#else
 560#	define APM_DECL_SEGS
 561#	define APM_DO_SAVE_SEGS
 562#	define APM_DO_RESTORE_SEGS
 563#endif
 564
 565struct apm_bios_call {
 566	u32 func;
 567	/* In and out */
 568	u32 ebx;
 569	u32 ecx;
 570	/* Out only */
 571	u32 eax;
 572	u32 edx;
 573	u32 esi;
 574
 575	/* Error: -ENOMEM, or bits 8-15 of eax */
 576	int err;
 577};
 578
 579/**
 580 *	__apm_bios_call - Make an APM BIOS 32bit call
 581 *	@_call: pointer to struct apm_bios_call.
 582 *
 583 *	Make an APM call using the 32bit protected mode interface. The
 584 *	caller is responsible for knowing if APM BIOS is configured and
 585 *	enabled. This call can disable interrupts for a long period of
 586 *	time on some laptops.  The return value is in AH and the carry
 587 *	flag is loaded into AL.  If there is an error, then the error
 588 *	code is returned in AH (bits 8-15 of eax) and this function
 589 *	returns non-zero.
 590 *
 591 *	Note: this makes the call on the current CPU.
 592 */
 593static long __apm_bios_call(void *_call)
 594{
 595	APM_DECL_SEGS
 596	unsigned long		flags;
 597	int			cpu;
 598	struct desc_struct	save_desc_40;
 599	struct desc_struct	*gdt;
 600	struct apm_bios_call	*call = _call;
 
 601
 602	cpu = get_cpu();
 603	BUG_ON(cpu != 0);
 604	gdt = get_cpu_gdt_rw(cpu);
 605	save_desc_40 = gdt[0x40 / 8];
 606	gdt[0x40 / 8] = bad_bios_desc;
 607
 608	apm_irq_save(flags);
 609	firmware_restrict_branch_speculation_start();
 
 610	APM_DO_SAVE_SEGS;
 611	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 612			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 613			  &call->esi);
 614	APM_DO_RESTORE_SEGS;
 
 615	firmware_restrict_branch_speculation_end();
 616	apm_irq_restore(flags);
 617	gdt[0x40 / 8] = save_desc_40;
 618	put_cpu();
 619
 620	return call->eax & 0xff;
 621}
 622
 623/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 624static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 625{
 626	int ret;
 627
 628	/* Don't bother with work_on_cpu in the common case, so we don't
 629	 * have to worry about OOM or overhead. */
 630	if (get_cpu() == 0) {
 631		ret = fn(call);
 632		put_cpu();
 633	} else {
 634		put_cpu();
 635		ret = work_on_cpu(0, fn, call);
 636	}
 637
 638	/* work_on_cpu can fail with -ENOMEM */
 639	if (ret < 0)
 640		call->err = ret;
 641	else
 642		call->err = (call->eax >> 8) & 0xff;
 643
 644	return ret;
 645}
 646
 647/**
 648 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 649 *	@call: the apm_bios_call registers.
 650 *
 651 *	If there is an error, it is returned in @call.err.
 652 */
 653static int apm_bios_call(struct apm_bios_call *call)
 654{
 655	return on_cpu0(__apm_bios_call, call);
 656}
 657
 658/**
 659 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 660 *	@_call: pointer to struct apm_bios_call.
 661 *
 662 *	Make a BIOS call that returns one value only, or just status.
 663 *	If there is an error, then the error code is returned in AH
 664 *	(bits 8-15 of eax) and this function returns non-zero (it can
 665 *	also return -ENOMEM). This is used for simpler BIOS operations.
 666 *	This call may hold interrupts off for a long time on some laptops.
 667 *
 668 *	Note: this makes the call on the current CPU.
 669 */
 670static long __apm_bios_call_simple(void *_call)
 671{
 672	u8			error;
 673	APM_DECL_SEGS
 674	unsigned long		flags;
 675	int			cpu;
 676	struct desc_struct	save_desc_40;
 677	struct desc_struct	*gdt;
 678	struct apm_bios_call	*call = _call;
 
 679
 680	cpu = get_cpu();
 681	BUG_ON(cpu != 0);
 682	gdt = get_cpu_gdt_rw(cpu);
 683	save_desc_40 = gdt[0x40 / 8];
 684	gdt[0x40 / 8] = bad_bios_desc;
 685
 686	apm_irq_save(flags);
 687	firmware_restrict_branch_speculation_start();
 
 688	APM_DO_SAVE_SEGS;
 689	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 690					 &call->eax);
 691	APM_DO_RESTORE_SEGS;
 
 692	firmware_restrict_branch_speculation_end();
 693	apm_irq_restore(flags);
 694	gdt[0x40 / 8] = save_desc_40;
 695	put_cpu();
 696	return error;
 697}
 698
 699/**
 700 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 701 *	@func: APM function to invoke
 702 *	@ebx_in: EBX register value for BIOS call
 703 *	@ecx_in: ECX register value for BIOS call
 704 *	@eax: EAX register on return from the BIOS call
 705 *	@err: bits
 706 *
 707 *	Make a BIOS call that returns one value only, or just status.
 708 *	If there is an error, then the error code is returned in @err
 709 *	and this function returns non-zero. This is used for simpler
 710 *	BIOS operations.  This call may hold interrupts off for a long
 711 *	time on some laptops.
 712 */
 713static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 714				int *err)
 715{
 716	struct apm_bios_call call;
 717	int ret;
 718
 719	call.func = func;
 720	call.ebx = ebx_in;
 721	call.ecx = ecx_in;
 722
 723	ret = on_cpu0(__apm_bios_call_simple, &call);
 724	*eax = call.eax;
 725	*err = call.err;
 726	return ret;
 727}
 728
 729/**
 730 *	apm_driver_version	-	APM driver version
 731 *	@val:	loaded with the APM version on return
 732 *
 733 *	Retrieve the APM version supported by the BIOS. This is only
 734 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 735 *	probably present.
 736 *
 737 *	On entry val should point to a value indicating the APM driver
 738 *	version with the high byte being the major and the low byte the
 739 *	minor number both in BCD
 740 *
 741 *	On return it will hold the BIOS revision supported in the
 742 *	same format.
 743 */
 744
 745static int apm_driver_version(u_short *val)
 746{
 747	u32 eax;
 748	int err;
 749
 750	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 751		return err;
 752	*val = eax;
 753	return APM_SUCCESS;
 754}
 755
 756/**
 757 *	apm_get_event	-	get an APM event from the BIOS
 758 *	@event: pointer to the event
 759 *	@info: point to the event information
 760 *
 761 *	The APM BIOS provides a polled information for event
 762 *	reporting. The BIOS expects to be polled at least every second
 763 *	when events are pending. When a message is found the caller should
 764 *	poll until no more messages are present.  However, this causes
 765 *	problems on some laptops where a suspend event notification is
 766 *	not cleared until it is acknowledged.
 767 *
 768 *	Additional information is returned in the info pointer, providing
 769 *	that APM 1.2 is in use. If no messges are pending the value 0x80
 770 *	is returned (No power management events pending).
 771 */
 772static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 773{
 774	struct apm_bios_call call;
 775
 776	call.func = APM_FUNC_GET_EVENT;
 777	call.ebx = call.ecx = 0;
 778
 779	if (apm_bios_call(&call))
 780		return call.err;
 781
 782	*event = call.ebx;
 783	if (apm_info.connection_version < 0x0102)
 784		*info = ~0; /* indicate info not valid */
 785	else
 786		*info = call.ecx;
 787	return APM_SUCCESS;
 788}
 789
 790/**
 791 *	set_power_state	-	set the power management state
 792 *	@what: which items to transition
 793 *	@state: state to transition to
 794 *
 795 *	Request an APM change of state for one or more system devices. The
 796 *	processor state must be transitioned last of all. what holds the
 797 *	class of device in the upper byte and the device number (0xFF for
 798 *	all) for the object to be transitioned.
 799 *
 800 *	The state holds the state to transition to, which may in fact
 801 *	be an acceptance of a BIOS requested state change.
 802 */
 803
 804static int set_power_state(u_short what, u_short state)
 805{
 806	u32 eax;
 807	int err;
 808
 809	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 810		return err;
 811	return APM_SUCCESS;
 812}
 813
 814/**
 815 *	set_system_power_state - set system wide power state
 816 *	@state: which state to enter
 817 *
 818 *	Transition the entire system into a new APM power state.
 819 */
 820
 821static int set_system_power_state(u_short state)
 822{
 823	return set_power_state(APM_DEVICE_ALL, state);
 824}
 825
 826/**
 827 *	apm_do_idle	-	perform power saving
 828 *
 829 *	This function notifies the BIOS that the processor is (in the view
 830 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 831 *	to handle the idle request. On a success the function returns 1
 832 *	if the BIOS did clock slowing or 0 otherwise.
 833 */
 834
 835static int apm_do_idle(void)
 836{
 837	u32 eax;
 838	u8 ret = 0;
 839	int idled = 0;
 840	int err = 0;
 841
 842	if (!need_resched()) {
 843		idled = 1;
 844		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 845	}
 846
 847	if (!idled)
 848		return 0;
 849
 850	if (ret) {
 851		static unsigned long t;
 852
 853		/* This always fails on some SMP boards running UP kernels.
 854		 * Only report the failure the first 5 times.
 855		 */
 856		if (++t < 5) {
 857			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 858			t = jiffies;
 859		}
 860		return -1;
 861	}
 862	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 863	return clock_slowed;
 864}
 865
 866/**
 867 *	apm_do_busy	-	inform the BIOS the CPU is busy
 868 *
 869 *	Request that the BIOS brings the CPU back to full performance.
 870 */
 871
 872static void apm_do_busy(void)
 873{
 874	u32 dummy;
 875	int err;
 876
 877	if (clock_slowed || ALWAYS_CALL_BUSY) {
 878		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 879		clock_slowed = 0;
 880	}
 881}
 882
 883/*
 884 * If no process has really been interested in
 885 * the CPU for some time, we want to call BIOS
 886 * power management - we probably want
 887 * to conserve power.
 888 */
 889#define IDLE_CALC_LIMIT	(HZ * 100)
 890#define IDLE_LEAKY_MAX	16
 891
 892/**
 893 * apm_cpu_idle		-	cpu idling for APM capable Linux
 894 *
 895 * This is the idling function the kernel executes when APM is available. It
 896 * tries to do BIOS powermanagement based on the average system idle time.
 897 * Furthermore it calls the system default idle routine.
 898 */
 899
 900static int apm_cpu_idle(struct cpuidle_device *dev,
 901	struct cpuidle_driver *drv, int index)
 902{
 903	static int use_apm_idle; /* = 0 */
 904	static unsigned int last_jiffies; /* = 0 */
 905	static u64 last_stime; /* = 0 */
 906	u64 stime, utime;
 907
 908	int apm_idle_done = 0;
 909	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 910	unsigned int bucket;
 911
 912recalc:
 913	task_cputime(current, &utime, &stime);
 914	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 915		use_apm_idle = 0;
 916	} else if (jiffies_since_last_check > idle_period) {
 917		unsigned int idle_percentage;
 918
 919		idle_percentage = nsecs_to_jiffies(stime - last_stime);
 920		idle_percentage *= 100;
 921		idle_percentage /= jiffies_since_last_check;
 922		use_apm_idle = (idle_percentage > idle_threshold);
 923		if (apm_info.forbid_idle)
 924			use_apm_idle = 0;
 925	}
 926
 927	last_jiffies = jiffies;
 928	last_stime = stime;
 929
 930	bucket = IDLE_LEAKY_MAX;
 931
 932	while (!need_resched()) {
 933		if (use_apm_idle) {
 934			unsigned int t;
 935
 936			t = jiffies;
 937			switch (apm_do_idle()) {
 938			case 0:
 939				apm_idle_done = 1;
 940				if (t != jiffies) {
 941					if (bucket) {
 942						bucket = IDLE_LEAKY_MAX;
 943						continue;
 944					}
 945				} else if (bucket) {
 946					bucket--;
 947					continue;
 948				}
 949				break;
 950			case 1:
 951				apm_idle_done = 1;
 952				break;
 953			default: /* BIOS refused */
 954				break;
 955			}
 956		}
 957		default_idle();
 958		local_irq_disable();
 959		jiffies_since_last_check = jiffies - last_jiffies;
 960		if (jiffies_since_last_check > idle_period)
 961			goto recalc;
 962	}
 963
 964	if (apm_idle_done)
 965		apm_do_busy();
 966
 967	return index;
 968}
 969
 970/**
 971 *	apm_power_off	-	ask the BIOS to power off
 972 *
 973 *	Handle the power off sequence. This is the one piece of code we
 974 *	will execute even on SMP machines. In order to deal with BIOS
 975 *	bugs we support real mode APM BIOS power off calls. We also make
 976 *	the SMP call on CPU0 as some systems will only honour this call
 977 *	on their first cpu.
 978 */
 979
 980static void apm_power_off(void)
 981{
 982	/* Some bioses don't like being called from CPU != 0 */
 983	if (apm_info.realmode_power_off) {
 984		set_cpus_allowed_ptr(current, cpumask_of(0));
 985		machine_real_restart(MRR_APM);
 986	} else {
 987		(void)set_system_power_state(APM_STATE_OFF);
 988	}
 989}
 990
 991#ifdef CONFIG_APM_DO_ENABLE
 992
 993/**
 994 *	apm_enable_power_management - enable BIOS APM power management
 995 *	@enable: enable yes/no
 996 *
 997 *	Enable or disable the APM BIOS power services.
 998 */
 999
1000static int apm_enable_power_management(int enable)
1001{
1002	u32 eax;
1003	int err;
1004
1005	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1006		return APM_NOT_ENGAGED;
1007	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1008				 enable, &eax, &err))
1009		return err;
1010	if (enable)
1011		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1012	else
1013		apm_info.bios.flags |= APM_BIOS_DISABLED;
1014	return APM_SUCCESS;
1015}
1016#endif
1017
1018/**
1019 *	apm_get_power_status	-	get current power state
1020 *	@status: returned status
1021 *	@bat: battery info
1022 *	@life: estimated life
1023 *
1024 *	Obtain the current power status from the APM BIOS. We return a
1025 *	status which gives the rough battery status, and current power
1026 *	source. The bat value returned give an estimate as a percentage
1027 *	of life and a status value for the battery. The estimated life
1028 *	if reported is a lifetime in secodnds/minutes at current powwer
1029 *	consumption.
1030 */
1031
1032static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1033{
1034	struct apm_bios_call call;
1035
1036	call.func = APM_FUNC_GET_STATUS;
1037	call.ebx = APM_DEVICE_ALL;
1038	call.ecx = 0;
1039
1040	if (apm_info.get_power_status_broken)
1041		return APM_32_UNSUPPORTED;
1042	if (apm_bios_call(&call)) {
1043		if (!call.err)
1044			return APM_NO_ERROR;
1045		return call.err;
1046	}
1047	*status = call.ebx;
1048	*bat = call.ecx;
1049	if (apm_info.get_power_status_swabinminutes) {
1050		*life = swab16((u16)call.edx);
1051		*life |= 0x8000;
1052	} else
1053		*life = call.edx;
1054	return APM_SUCCESS;
1055}
1056
1057#if 0
1058static int apm_get_battery_status(u_short which, u_short *status,
1059				  u_short *bat, u_short *life, u_short *nbat)
1060{
1061	u32 eax;
1062	u32 ebx;
1063	u32 ecx;
1064	u32 edx;
1065	u32 esi;
1066
1067	if (apm_info.connection_version < 0x0102) {
1068		/* pretend we only have one battery. */
1069		if (which != 1)
1070			return APM_BAD_DEVICE;
1071		*nbat = 1;
1072		return apm_get_power_status(status, bat, life);
1073	}
1074
1075	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1076			  &ebx, &ecx, &edx, &esi))
1077		return (eax >> 8) & 0xff;
1078	*status = ebx;
1079	*bat = ecx;
1080	*life = edx;
1081	*nbat = esi;
1082	return APM_SUCCESS;
1083}
1084#endif
1085
1086/**
1087 *	apm_engage_power_management	-	enable PM on a device
1088 *	@device: identity of device
1089 *	@enable: on/off
1090 *
1091 *	Activate or deactivate power management on either a specific device
1092 *	or the entire system (%APM_DEVICE_ALL).
1093 */
1094
1095static int apm_engage_power_management(u_short device, int enable)
1096{
1097	u32 eax;
1098	int err;
1099
1100	if ((enable == 0) && (device == APM_DEVICE_ALL)
1101	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1102		return APM_DISABLED;
1103	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1104				 &eax, &err))
1105		return err;
1106	if (device == APM_DEVICE_ALL) {
1107		if (enable)
1108			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1109		else
1110			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1111	}
1112	return APM_SUCCESS;
1113}
1114
1115#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1116
1117/**
1118 *	apm_console_blank	-	blank the display
1119 *	@blank: on/off
1120 *
1121 *	Attempt to blank the console, firstly by blanking just video device
1122 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1123 *	all video devices. Typically the BIOS will do laptop backlight and
1124 *	monitor powerdown for us.
1125 */
1126
1127static int apm_console_blank(int blank)
1128{
1129	int error = APM_NOT_ENGAGED; /* silence gcc */
1130	int i;
1131	u_short state;
1132	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1133
1134	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1135
1136	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1137		error = set_power_state(dev[i], state);
1138
1139		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1140			return 1;
1141
1142		if (error == APM_NOT_ENGAGED)
1143			break;
1144	}
1145
1146	if (error == APM_NOT_ENGAGED) {
1147		static int tried;
1148		int eng_error;
1149		if (tried++ == 0) {
1150			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1151			if (eng_error) {
1152				apm_error("set display", error);
1153				apm_error("engage interface", eng_error);
1154				return 0;
1155			} else
1156				return apm_console_blank(blank);
1157		}
1158	}
1159	apm_error("set display", error);
1160	return 0;
1161}
1162#endif
1163
1164static int queue_empty(struct apm_user *as)
1165{
1166	return as->event_head == as->event_tail;
1167}
1168
1169static apm_event_t get_queued_event(struct apm_user *as)
1170{
1171	if (++as->event_tail >= APM_MAX_EVENTS)
1172		as->event_tail = 0;
1173	return as->events[as->event_tail];
1174}
1175
1176static void queue_event(apm_event_t event, struct apm_user *sender)
1177{
1178	struct apm_user *as;
1179
1180	spin_lock(&user_list_lock);
1181	if (user_list == NULL)
1182		goto out;
1183	for (as = user_list; as != NULL; as = as->next) {
1184		if ((as == sender) || (!as->reader))
1185			continue;
1186		if (++as->event_head >= APM_MAX_EVENTS)
1187			as->event_head = 0;
1188
1189		if (as->event_head == as->event_tail) {
1190			static int notified;
1191
1192			if (notified++ == 0)
1193				pr_err("an event queue overflowed\n");
1194			if (++as->event_tail >= APM_MAX_EVENTS)
1195				as->event_tail = 0;
1196		}
1197		as->events[as->event_head] = event;
1198		if (!as->suser || !as->writer)
1199			continue;
1200		switch (event) {
1201		case APM_SYS_SUSPEND:
1202		case APM_USER_SUSPEND:
1203			as->suspends_pending++;
1204			suspends_pending++;
1205			break;
1206
1207		case APM_SYS_STANDBY:
1208		case APM_USER_STANDBY:
1209			as->standbys_pending++;
1210			standbys_pending++;
1211			break;
1212		}
1213	}
1214	wake_up_interruptible(&apm_waitqueue);
1215out:
1216	spin_unlock(&user_list_lock);
1217}
1218
1219static void reinit_timer(void)
1220{
1221#ifdef INIT_TIMER_AFTER_SUSPEND
1222	unsigned long flags;
1223
1224	raw_spin_lock_irqsave(&i8253_lock, flags);
1225	/* set the clock to HZ */
1226	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1227	udelay(10);
1228	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1229	udelay(10);
1230	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1231	udelay(10);
1232	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1233#endif
1234}
1235
1236static int suspend(int vetoable)
1237{
1238	int err;
1239	struct apm_user	*as;
1240
1241	dpm_suspend_start(PMSG_SUSPEND);
1242	dpm_suspend_end(PMSG_SUSPEND);
1243
1244	local_irq_disable();
1245	syscore_suspend();
1246
1247	local_irq_enable();
1248
1249	save_processor_state();
1250	err = set_system_power_state(APM_STATE_SUSPEND);
1251	ignore_normal_resume = 1;
1252	restore_processor_state();
1253
1254	local_irq_disable();
1255	reinit_timer();
1256
1257	if (err == APM_NO_ERROR)
1258		err = APM_SUCCESS;
1259	if (err != APM_SUCCESS)
1260		apm_error("suspend", err);
1261	err = (err == APM_SUCCESS) ? 0 : -EIO;
1262
1263	syscore_resume();
1264	local_irq_enable();
1265
1266	dpm_resume_start(PMSG_RESUME);
1267	dpm_resume_end(PMSG_RESUME);
1268
1269	queue_event(APM_NORMAL_RESUME, NULL);
1270	spin_lock(&user_list_lock);
1271	for (as = user_list; as != NULL; as = as->next) {
1272		as->suspend_wait = 0;
1273		as->suspend_result = err;
1274	}
1275	spin_unlock(&user_list_lock);
1276	wake_up_interruptible(&apm_suspend_waitqueue);
1277	return err;
1278}
1279
1280static void standby(void)
1281{
1282	int err;
1283
1284	dpm_suspend_end(PMSG_SUSPEND);
1285
1286	local_irq_disable();
1287	syscore_suspend();
1288	local_irq_enable();
1289
1290	err = set_system_power_state(APM_STATE_STANDBY);
1291	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1292		apm_error("standby", err);
1293
1294	local_irq_disable();
1295	syscore_resume();
1296	local_irq_enable();
1297
1298	dpm_resume_start(PMSG_RESUME);
1299}
1300
1301static apm_event_t get_event(void)
1302{
1303	int error;
1304	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1305	apm_eventinfo_t	info;
1306
1307	static int notified;
1308
1309	/* we don't use the eventinfo */
1310	error = apm_get_event(&event, &info);
1311	if (error == APM_SUCCESS)
1312		return event;
1313
1314	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1315		apm_error("get_event", error);
1316
1317	return 0;
1318}
1319
1320static void check_events(void)
1321{
1322	apm_event_t event;
1323	static unsigned long last_resume;
1324	static int ignore_bounce;
1325
1326	while ((event = get_event()) != 0) {
1327		if (debug) {
1328			if (event <= NR_APM_EVENT_NAME)
1329				printk(KERN_DEBUG "apm: received %s notify\n",
1330				       apm_event_name[event - 1]);
1331			else
1332				printk(KERN_DEBUG "apm: received unknown "
1333				       "event 0x%02x\n", event);
1334		}
1335		if (ignore_bounce
1336		    && (time_after(jiffies, last_resume + bounce_interval)))
1337			ignore_bounce = 0;
1338
1339		switch (event) {
1340		case APM_SYS_STANDBY:
1341		case APM_USER_STANDBY:
1342			queue_event(event, NULL);
1343			if (standbys_pending <= 0)
1344				standby();
1345			break;
1346
1347		case APM_USER_SUSPEND:
1348#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1349			if (apm_info.connection_version > 0x100)
1350				set_system_power_state(APM_STATE_REJECT);
1351			break;
1352#endif
1353		case APM_SYS_SUSPEND:
1354			if (ignore_bounce) {
1355				if (apm_info.connection_version > 0x100)
1356					set_system_power_state(APM_STATE_REJECT);
1357				break;
1358			}
1359			/*
1360			 * If we are already processing a SUSPEND,
1361			 * then further SUSPEND events from the BIOS
1362			 * will be ignored.  We also return here to
1363			 * cope with the fact that the Thinkpads keep
1364			 * sending a SUSPEND event until something else
1365			 * happens!
1366			 */
1367			if (ignore_sys_suspend)
1368				return;
1369			ignore_sys_suspend = 1;
1370			queue_event(event, NULL);
1371			if (suspends_pending <= 0)
1372				(void) suspend(1);
1373			break;
1374
1375		case APM_NORMAL_RESUME:
1376		case APM_CRITICAL_RESUME:
1377		case APM_STANDBY_RESUME:
1378			ignore_sys_suspend = 0;
1379			last_resume = jiffies;
1380			ignore_bounce = 1;
1381			if ((event != APM_NORMAL_RESUME)
1382			    || (ignore_normal_resume == 0)) {
1383				dpm_resume_end(PMSG_RESUME);
1384				queue_event(event, NULL);
1385			}
1386			ignore_normal_resume = 0;
1387			break;
1388
1389		case APM_CAPABILITY_CHANGE:
1390		case APM_LOW_BATTERY:
1391		case APM_POWER_STATUS_CHANGE:
1392			queue_event(event, NULL);
1393			/* If needed, notify drivers here */
1394			break;
1395
1396		case APM_UPDATE_TIME:
1397			break;
1398
1399		case APM_CRITICAL_SUSPEND:
1400			/*
1401			 * We are not allowed to reject a critical suspend.
1402			 */
1403			(void)suspend(0);
1404			break;
1405		}
1406	}
1407}
1408
1409static void apm_event_handler(void)
1410{
1411	static int pending_count = 4;
1412	int err;
1413
1414	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1415		if ((apm_info.connection_version > 0x100) &&
1416		    (pending_count-- <= 0)) {
1417			pending_count = 4;
1418			if (debug)
1419				printk(KERN_DEBUG "apm: setting state busy\n");
1420			err = set_system_power_state(APM_STATE_BUSY);
1421			if (err)
1422				apm_error("busy", err);
1423		}
1424	} else
1425		pending_count = 4;
1426	check_events();
1427}
1428
1429/*
1430 * This is the APM thread main loop.
1431 */
1432
1433static void apm_mainloop(void)
1434{
1435	DECLARE_WAITQUEUE(wait, current);
1436
1437	add_wait_queue(&apm_waitqueue, &wait);
1438	set_current_state(TASK_INTERRUPTIBLE);
1439	for (;;) {
1440		schedule_timeout(APM_CHECK_TIMEOUT);
1441		if (kthread_should_stop())
1442			break;
1443		/*
1444		 * Ok, check all events, check for idle (and mark us sleeping
1445		 * so as not to count towards the load average)..
1446		 */
1447		set_current_state(TASK_INTERRUPTIBLE);
1448		apm_event_handler();
1449	}
1450	remove_wait_queue(&apm_waitqueue, &wait);
1451}
1452
1453static int check_apm_user(struct apm_user *as, const char *func)
1454{
1455	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1456		pr_err("%s passed bad filp\n", func);
1457		return 1;
1458	}
1459	return 0;
1460}
1461
1462static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1463{
1464	struct apm_user *as;
1465	int i;
1466	apm_event_t event;
1467
1468	as = fp->private_data;
1469	if (check_apm_user(as, "read"))
1470		return -EIO;
1471	if ((int)count < sizeof(apm_event_t))
1472		return -EINVAL;
1473	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1474		return -EAGAIN;
1475	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1476	i = count;
1477	while ((i >= sizeof(event)) && !queue_empty(as)) {
1478		event = get_queued_event(as);
1479		if (copy_to_user(buf, &event, sizeof(event))) {
1480			if (i < count)
1481				break;
1482			return -EFAULT;
1483		}
1484		switch (event) {
1485		case APM_SYS_SUSPEND:
1486		case APM_USER_SUSPEND:
1487			as->suspends_read++;
1488			break;
1489
1490		case APM_SYS_STANDBY:
1491		case APM_USER_STANDBY:
1492			as->standbys_read++;
1493			break;
1494		}
1495		buf += sizeof(event);
1496		i -= sizeof(event);
1497	}
1498	if (i < count)
1499		return count - i;
1500	if (signal_pending(current))
1501		return -ERESTARTSYS;
1502	return 0;
1503}
1504
1505static __poll_t do_poll(struct file *fp, poll_table *wait)
1506{
1507	struct apm_user *as;
1508
1509	as = fp->private_data;
1510	if (check_apm_user(as, "poll"))
1511		return 0;
1512	poll_wait(fp, &apm_waitqueue, wait);
1513	if (!queue_empty(as))
1514		return EPOLLIN | EPOLLRDNORM;
1515	return 0;
1516}
1517
1518static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1519{
1520	struct apm_user *as;
1521	int ret;
1522
1523	as = filp->private_data;
1524	if (check_apm_user(as, "ioctl"))
1525		return -EIO;
1526	if (!as->suser || !as->writer)
1527		return -EPERM;
1528	switch (cmd) {
1529	case APM_IOC_STANDBY:
1530		mutex_lock(&apm_mutex);
1531		if (as->standbys_read > 0) {
1532			as->standbys_read--;
1533			as->standbys_pending--;
1534			standbys_pending--;
1535		} else
1536			queue_event(APM_USER_STANDBY, as);
1537		if (standbys_pending <= 0)
1538			standby();
1539		mutex_unlock(&apm_mutex);
1540		break;
1541	case APM_IOC_SUSPEND:
1542		mutex_lock(&apm_mutex);
1543		if (as->suspends_read > 0) {
1544			as->suspends_read--;
1545			as->suspends_pending--;
1546			suspends_pending--;
1547		} else
1548			queue_event(APM_USER_SUSPEND, as);
1549		if (suspends_pending <= 0) {
1550			ret = suspend(1);
1551			mutex_unlock(&apm_mutex);
1552		} else {
1553			as->suspend_wait = 1;
1554			mutex_unlock(&apm_mutex);
1555			wait_event_interruptible(apm_suspend_waitqueue,
1556					as->suspend_wait == 0);
1557			ret = as->suspend_result;
1558		}
1559		return ret;
1560	default:
1561		return -ENOTTY;
1562	}
1563	return 0;
1564}
1565
1566static int do_release(struct inode *inode, struct file *filp)
1567{
1568	struct apm_user *as;
1569
1570	as = filp->private_data;
1571	if (check_apm_user(as, "release"))
1572		return 0;
1573	filp->private_data = NULL;
1574	if (as->standbys_pending > 0) {
1575		standbys_pending -= as->standbys_pending;
1576		if (standbys_pending <= 0)
1577			standby();
1578	}
1579	if (as->suspends_pending > 0) {
1580		suspends_pending -= as->suspends_pending;
1581		if (suspends_pending <= 0)
1582			(void) suspend(1);
1583	}
1584	spin_lock(&user_list_lock);
1585	if (user_list == as)
1586		user_list = as->next;
1587	else {
1588		struct apm_user *as1;
1589
1590		for (as1 = user_list;
1591		     (as1 != NULL) && (as1->next != as);
1592		     as1 = as1->next)
1593			;
1594		if (as1 == NULL)
1595			pr_err("filp not in user list\n");
1596		else
1597			as1->next = as->next;
1598	}
1599	spin_unlock(&user_list_lock);
1600	kfree(as);
1601	return 0;
1602}
1603
1604static int do_open(struct inode *inode, struct file *filp)
1605{
1606	struct apm_user *as;
1607
1608	as = kmalloc(sizeof(*as), GFP_KERNEL);
1609	if (as == NULL)
1610		return -ENOMEM;
1611
1612	as->magic = APM_BIOS_MAGIC;
1613	as->event_tail = as->event_head = 0;
1614	as->suspends_pending = as->standbys_pending = 0;
1615	as->suspends_read = as->standbys_read = 0;
1616	/*
1617	 * XXX - this is a tiny bit broken, when we consider BSD
1618	 * process accounting. If the device is opened by root, we
1619	 * instantly flag that we used superuser privs. Who knows,
1620	 * we might close the device immediately without doing a
1621	 * privileged operation -- cevans
1622	 */
1623	as->suser = capable(CAP_SYS_ADMIN);
1624	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1625	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1626	spin_lock(&user_list_lock);
1627	as->next = user_list;
1628	user_list = as;
1629	spin_unlock(&user_list_lock);
1630	filp->private_data = as;
1631	return 0;
1632}
1633
1634#ifdef CONFIG_PROC_FS
1635static int proc_apm_show(struct seq_file *m, void *v)
1636{
1637	unsigned short	bx;
1638	unsigned short	cx;
1639	unsigned short	dx;
1640	int		error;
1641	unsigned short  ac_line_status = 0xff;
1642	unsigned short  battery_status = 0xff;
1643	unsigned short  battery_flag   = 0xff;
1644	int		percentage     = -1;
1645	int             time_units     = -1;
1646	char            *units         = "?";
1647
1648	if ((num_online_cpus() == 1) &&
1649	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1650		ac_line_status = (bx >> 8) & 0xff;
1651		battery_status = bx & 0xff;
1652		if ((cx & 0xff) != 0xff)
1653			percentage = cx & 0xff;
1654
1655		if (apm_info.connection_version > 0x100) {
1656			battery_flag = (cx >> 8) & 0xff;
1657			if (dx != 0xffff) {
1658				units = (dx & 0x8000) ? "min" : "sec";
1659				time_units = dx & 0x7fff;
1660			}
1661		}
1662	}
1663	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1664	   from the Get Power Status (0x0a) call unless otherwise noted.
1665
1666	   0) Linux driver version (this will change if format changes)
1667	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1668	   2) APM flags from APM Installation Check (0x00):
1669	      bit 0: APM_16_BIT_SUPPORT
1670	      bit 1: APM_32_BIT_SUPPORT
1671	      bit 2: APM_IDLE_SLOWS_CLOCK
1672	      bit 3: APM_BIOS_DISABLED
1673	      bit 4: APM_BIOS_DISENGAGED
1674	   3) AC line status
1675	      0x00: Off-line
1676	      0x01: On-line
1677	      0x02: On backup power (BIOS >= 1.1 only)
1678	      0xff: Unknown
1679	   4) Battery status
1680	      0x00: High
1681	      0x01: Low
1682	      0x02: Critical
1683	      0x03: Charging
1684	      0x04: Selected battery not present (BIOS >= 1.2 only)
1685	      0xff: Unknown
1686	   5) Battery flag
1687	      bit 0: High
1688	      bit 1: Low
1689	      bit 2: Critical
1690	      bit 3: Charging
1691	      bit 7: No system battery
1692	      0xff: Unknown
1693	   6) Remaining battery life (percentage of charge):
1694	      0-100: valid
1695	      -1: Unknown
1696	   7) Remaining battery life (time units):
1697	      Number of remaining minutes or seconds
1698	      -1: Unknown
1699	   8) min = minutes; sec = seconds */
1700
1701	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1702		   driver_version,
1703		   (apm_info.bios.version >> 8) & 0xff,
1704		   apm_info.bios.version & 0xff,
1705		   apm_info.bios.flags,
1706		   ac_line_status,
1707		   battery_status,
1708		   battery_flag,
1709		   percentage,
1710		   time_units,
1711		   units);
1712	return 0;
1713}
1714#endif
1715
1716static int apm(void *unused)
1717{
1718	unsigned short	bx;
1719	unsigned short	cx;
1720	unsigned short	dx;
1721	int		error;
1722	char 		*power_stat;
1723	char 		*bat_stat;
1724
1725	/* 2002/08/01 - WT
1726	 * This is to avoid random crashes at boot time during initialization
1727	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1728	 * Some bioses don't like being called from CPU != 0.
1729	 * Method suggested by Ingo Molnar.
1730	 */
1731	set_cpus_allowed_ptr(current, cpumask_of(0));
1732	BUG_ON(smp_processor_id() != 0);
1733
1734	if (apm_info.connection_version == 0) {
1735		apm_info.connection_version = apm_info.bios.version;
1736		if (apm_info.connection_version > 0x100) {
1737			/*
1738			 * We only support BIOSs up to version 1.2
1739			 */
1740			if (apm_info.connection_version > 0x0102)
1741				apm_info.connection_version = 0x0102;
1742			error = apm_driver_version(&apm_info.connection_version);
1743			if (error != APM_SUCCESS) {
1744				apm_error("driver version", error);
1745				/* Fall back to an APM 1.0 connection. */
1746				apm_info.connection_version = 0x100;
1747			}
1748		}
1749	}
1750
1751	if (debug)
1752		printk(KERN_INFO "apm: Connection version %d.%d\n",
1753			(apm_info.connection_version >> 8) & 0xff,
1754			apm_info.connection_version & 0xff);
1755
1756#ifdef CONFIG_APM_DO_ENABLE
1757	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1758		/*
1759		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1760		 * is booted with PM disabled but not in the docking station.
1761		 * Unfortunate ...
1762		 */
1763		error = apm_enable_power_management(1);
1764		if (error) {
1765			apm_error("enable power management", error);
1766			return -1;
1767		}
1768	}
1769#endif
1770
1771	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1772	    && (apm_info.connection_version > 0x0100)) {
1773		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1774		if (error) {
1775			apm_error("engage power management", error);
1776			return -1;
1777		}
1778	}
1779
1780	if (debug && (num_online_cpus() == 1 || smp)) {
1781		error = apm_get_power_status(&bx, &cx, &dx);
1782		if (error)
1783			printk(KERN_INFO "apm: power status not available\n");
1784		else {
1785			switch ((bx >> 8) & 0xff) {
1786			case 0:
1787				power_stat = "off line";
1788				break;
1789			case 1:
1790				power_stat = "on line";
1791				break;
1792			case 2:
1793				power_stat = "on backup power";
1794				break;
1795			default:
1796				power_stat = "unknown";
1797				break;
1798			}
1799			switch (bx & 0xff) {
1800			case 0:
1801				bat_stat = "high";
1802				break;
1803			case 1:
1804				bat_stat = "low";
1805				break;
1806			case 2:
1807				bat_stat = "critical";
1808				break;
1809			case 3:
1810				bat_stat = "charging";
1811				break;
1812			default:
1813				bat_stat = "unknown";
1814				break;
1815			}
1816			printk(KERN_INFO
1817			       "apm: AC %s, battery status %s, battery life ",
1818			       power_stat, bat_stat);
1819			if ((cx & 0xff) == 0xff)
1820				printk("unknown\n");
1821			else
1822				printk("%d%%\n", cx & 0xff);
1823			if (apm_info.connection_version > 0x100) {
1824				printk(KERN_INFO
1825				       "apm: battery flag 0x%02x, battery life ",
1826				       (cx >> 8) & 0xff);
1827				if (dx == 0xffff)
1828					printk("unknown\n");
1829				else
1830					printk("%d %s\n", dx & 0x7fff,
1831					       (dx & 0x8000) ?
1832					       "minutes" : "seconds");
1833			}
1834		}
1835	}
1836
1837	/* Install our power off handler.. */
1838	if (power_off)
1839		pm_power_off = apm_power_off;
1840
1841	if (num_online_cpus() == 1 || smp) {
1842#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1843		console_blank_hook = apm_console_blank;
1844#endif
1845		apm_mainloop();
1846#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1847		console_blank_hook = NULL;
1848#endif
1849	}
1850
1851	return 0;
1852}
1853
1854#ifndef MODULE
1855static int __init apm_setup(char *str)
1856{
1857	int invert;
1858
1859	while ((str != NULL) && (*str != '\0')) {
1860		if (strncmp(str, "off", 3) == 0)
1861			apm_disabled = 1;
1862		if (strncmp(str, "on", 2) == 0)
1863			apm_disabled = 0;
1864		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1865		    (strncmp(str, "bounce_interval=", 16) == 0))
1866			bounce_interval = simple_strtol(str + 16, NULL, 0);
1867		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1868		    (strncmp(str, "idle_threshold=", 15) == 0))
1869			idle_threshold = simple_strtol(str + 15, NULL, 0);
1870		if ((strncmp(str, "idle-period=", 12) == 0) ||
1871		    (strncmp(str, "idle_period=", 12) == 0))
1872			idle_period = simple_strtol(str + 12, NULL, 0);
1873		invert = (strncmp(str, "no-", 3) == 0) ||
1874			(strncmp(str, "no_", 3) == 0);
1875		if (invert)
1876			str += 3;
1877		if (strncmp(str, "debug", 5) == 0)
1878			debug = !invert;
1879		if ((strncmp(str, "power-off", 9) == 0) ||
1880		    (strncmp(str, "power_off", 9) == 0))
1881			power_off = !invert;
1882		if (strncmp(str, "smp", 3) == 0) {
1883			smp = !invert;
1884			idle_threshold = 100;
1885		}
1886		if ((strncmp(str, "allow-ints", 10) == 0) ||
1887		    (strncmp(str, "allow_ints", 10) == 0))
1888			apm_info.allow_ints = !invert;
1889		if ((strncmp(str, "broken-psr", 10) == 0) ||
1890		    (strncmp(str, "broken_psr", 10) == 0))
1891			apm_info.get_power_status_broken = !invert;
1892		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1893		    (strncmp(str, "realmode_power_off", 18) == 0))
1894			apm_info.realmode_power_off = !invert;
1895		str = strchr(str, ',');
1896		if (str != NULL)
1897			str += strspn(str, ", \t");
1898	}
1899	return 1;
1900}
1901
1902__setup("apm=", apm_setup);
1903#endif
1904
1905static const struct file_operations apm_bios_fops = {
1906	.owner		= THIS_MODULE,
1907	.read		= do_read,
1908	.poll		= do_poll,
1909	.unlocked_ioctl	= do_ioctl,
1910	.open		= do_open,
1911	.release	= do_release,
1912	.llseek		= noop_llseek,
1913};
1914
1915static struct miscdevice apm_device = {
1916	APM_MINOR_DEV,
1917	"apm_bios",
1918	&apm_bios_fops
1919};
1920
1921
1922/* Simple "print if true" callback */
1923static int __init print_if_true(const struct dmi_system_id *d)
1924{
1925	printk("%s\n", d->ident);
1926	return 0;
1927}
1928
1929/*
1930 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1931 * disabled before the suspend. Linux used to get terribly confused by that.
1932 */
1933static int __init broken_ps2_resume(const struct dmi_system_id *d)
1934{
1935	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1936	       "workaround hopefully not needed.\n", d->ident);
1937	return 0;
1938}
1939
1940/* Some bioses have a broken protected mode poweroff and need to use realmode */
1941static int __init set_realmode_power_off(const struct dmi_system_id *d)
1942{
1943	if (apm_info.realmode_power_off == 0) {
1944		apm_info.realmode_power_off = 1;
1945		printk(KERN_INFO "%s bios detected. "
1946		       "Using realmode poweroff only.\n", d->ident);
1947	}
1948	return 0;
1949}
1950
1951/* Some laptops require interrupts to be enabled during APM calls */
1952static int __init set_apm_ints(const struct dmi_system_id *d)
1953{
1954	if (apm_info.allow_ints == 0) {
1955		apm_info.allow_ints = 1;
1956		printk(KERN_INFO "%s machine detected. "
1957		       "Enabling interrupts during APM calls.\n", d->ident);
1958	}
1959	return 0;
1960}
1961
1962/* Some APM bioses corrupt memory or just plain do not work */
1963static int __init apm_is_horked(const struct dmi_system_id *d)
1964{
1965	if (apm_info.disabled == 0) {
1966		apm_info.disabled = 1;
1967		printk(KERN_INFO "%s machine detected. "
1968		       "Disabling APM.\n", d->ident);
1969	}
1970	return 0;
1971}
1972
1973static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1974{
1975	if (apm_info.disabled == 0) {
1976		apm_info.disabled = 1;
1977		printk(KERN_INFO "%s machine detected. "
1978		       "Disabling APM.\n", d->ident);
1979		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1980		printk(KERN_INFO "download from support.intel.com\n");
1981	}
1982	return 0;
1983}
1984
1985/* Some APM bioses hang on APM idle calls */
1986static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1987{
1988	if (apm_info.forbid_idle == 0) {
1989		apm_info.forbid_idle = 1;
1990		printk(KERN_INFO "%s machine detected. "
1991		       "Disabling APM idle calls.\n", d->ident);
1992	}
1993	return 0;
1994}
1995
1996/*
1997 *  Check for clue free BIOS implementations who use
1998 *  the following QA technique
1999 *
2000 *      [ Write BIOS Code ]<------
2001 *               |                ^
2002 *      < Does it Compile >----N--
2003 *               |Y               ^
2004 *	< Does it Boot Win98 >-N--
2005 *               |Y
2006 *           [Ship It]
2007 *
2008 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2009 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2010 */
2011static int __init broken_apm_power(const struct dmi_system_id *d)
2012{
2013	apm_info.get_power_status_broken = 1;
2014	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2015	       "disabling power status reporting.\n");
2016	return 0;
2017}
2018
2019/*
2020 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2021 * have this problem).
2022 */
2023static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2024{
2025	apm_info.get_power_status_swabinminutes = 1;
2026	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2027	       "in minutes and wrong byte order.\n");
2028	return 0;
2029}
2030
2031static const struct dmi_system_id apm_dmi_table[] __initconst = {
2032	{
2033		print_if_true,
2034		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2035		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2036			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2037	},
2038	{	/* Handle problems with APM on the C600 */
2039		broken_ps2_resume, "Dell Latitude C600",
2040		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2041			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2042	},
2043	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2044		set_apm_ints, "Dell Latitude",
2045		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2046			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2047	},
2048	{	/* APM crashes */
2049		apm_is_horked, "Dell Inspiron 2500",
2050		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2051			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2052			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2053			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2054	},
2055	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2056		set_apm_ints, "Dell Inspiron", {
2057			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2058			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2059	},
2060	{	/* Handle problems with APM on Inspiron 5000e */
2061		broken_apm_power, "Dell Inspiron 5000e",
2062		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2063			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2064			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2065	},
2066	{	/* Handle problems with APM on Inspiron 2500 */
2067		broken_apm_power, "Dell Inspiron 2500",
2068		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2069			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2070			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2071	},
2072	{	/* APM crashes */
2073		apm_is_horked, "Dell Dimension 4100",
2074		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2075			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2076			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2077			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2078	},
2079	{	/* Allow interrupts during suspend on Compaq Laptops*/
2080		set_apm_ints, "Compaq 12XL125",
2081		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2082			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2083			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2084			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2085	},
2086	{	/* Allow interrupts during APM or the clock goes slow */
2087		set_apm_ints, "ASUSTeK",
2088		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2089			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2090	},
2091	{	/* APM blows on shutdown */
2092		apm_is_horked, "ABIT KX7-333[R]",
2093		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2094			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2095	},
2096	{	/* APM crashes */
2097		apm_is_horked, "Trigem Delhi3",
2098		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2099			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2100	},
2101	{	/* APM crashes */
2102		apm_is_horked, "Fujitsu-Siemens",
2103		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2104			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2105	},
2106	{	/* APM crashes */
2107		apm_is_horked_d850md, "Intel D850MD",
2108		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2109			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2110	},
2111	{	/* APM crashes */
2112		apm_is_horked, "Intel D810EMO",
2113		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2114			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2115	},
2116	{	/* APM crashes */
2117		apm_is_horked, "Dell XPS-Z",
2118		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2119			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2120			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2121	},
2122	{	/* APM crashes */
2123		apm_is_horked, "Sharp PC-PJ/AX",
2124		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2125			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2126			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2127			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2128	},
2129	{	/* APM crashes */
2130		apm_is_horked, "Dell Inspiron 2500",
2131		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2132			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2133			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2134			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2135	},
2136	{	/* APM idle hangs */
2137		apm_likes_to_melt, "Jabil AMD",
2138		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2139			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2140	},
2141	{	/* APM idle hangs */
2142		apm_likes_to_melt, "AMI Bios",
2143		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2144			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2145	},
2146	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2147		swab_apm_power_in_minutes, "Sony VAIO",
2148		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2149			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2150			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2151	},
2152	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2153		swab_apm_power_in_minutes, "Sony VAIO",
2154		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2155			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2156			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2157	},
2158	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2159		swab_apm_power_in_minutes, "Sony VAIO",
2160		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2161			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2162			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2163	},
2164	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2165		swab_apm_power_in_minutes, "Sony VAIO",
2166		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2167			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2168			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2169	},
2170	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2171		swab_apm_power_in_minutes, "Sony VAIO",
2172		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2173			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2174			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2175	},
2176	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2177		swab_apm_power_in_minutes, "Sony VAIO",
2178		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2179			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2180			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2181	},
2182	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2183		swab_apm_power_in_minutes, "Sony VAIO",
2184		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2185			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2186			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2187	},
2188	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2189		swab_apm_power_in_minutes, "Sony VAIO",
2190		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2191			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2192			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2193	},
2194	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2195		swab_apm_power_in_minutes, "Sony VAIO",
2196		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2197			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2198			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2199	},
2200	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2201		swab_apm_power_in_minutes, "Sony VAIO",
2202		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2203			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2204			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2205	},
2206
2207	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2208		swab_apm_power_in_minutes, "Sony VAIO",
2209		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2211			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2212	},
2213	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2214		swab_apm_power_in_minutes, "Sony VAIO",
2215		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2216			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2217			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2218	},
2219	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2220		swab_apm_power_in_minutes, "Sony VAIO",
2221		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2222			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2223			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2224	},
2225	{	/* broken PM poweroff bios */
2226		set_realmode_power_off, "Award Software v4.60 PGMA",
2227		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2228			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2229			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2230	},
2231
2232	/* Generic per vendor APM settings  */
2233
2234	{	/* Allow interrupts during suspend on IBM laptops */
2235		set_apm_ints, "IBM",
2236		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2237	},
2238
2239	{ }
2240};
2241
2242/*
2243 * Just start the APM thread. We do NOT want to do APM BIOS
2244 * calls from anything but the APM thread, if for no other reason
2245 * than the fact that we don't trust the APM BIOS. This way,
2246 * most common APM BIOS problems that lead to protection errors
2247 * etc will have at least some level of being contained...
2248 *
2249 * In short, if something bad happens, at least we have a choice
2250 * of just killing the apm thread..
2251 */
2252static int __init apm_init(void)
2253{
2254	struct desc_struct *gdt;
2255	int err;
2256
2257	dmi_check_system(apm_dmi_table);
2258
2259	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2260		printk(KERN_INFO "apm: BIOS not found.\n");
2261		return -ENODEV;
2262	}
2263	printk(KERN_INFO
2264	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2265	       ((apm_info.bios.version >> 8) & 0xff),
2266	       (apm_info.bios.version & 0xff),
2267	       apm_info.bios.flags,
2268	       driver_version);
2269	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2270		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2271		return -ENODEV;
2272	}
2273
2274	if (allow_ints)
2275		apm_info.allow_ints = 1;
2276	if (broken_psr)
2277		apm_info.get_power_status_broken = 1;
2278	if (realmode_power_off)
2279		apm_info.realmode_power_off = 1;
2280	/* User can override, but default is to trust DMI */
2281	if (apm_disabled != -1)
2282		apm_info.disabled = apm_disabled;
2283
2284	/*
2285	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2286	 * but is reportedly a 1.0 BIOS.
2287	 */
2288	if (apm_info.bios.version == 0x001)
2289		apm_info.bios.version = 0x100;
2290
2291	/* BIOS < 1.2 doesn't set cseg_16_len */
2292	if (apm_info.bios.version < 0x102)
2293		apm_info.bios.cseg_16_len = 0; /* 64k */
2294
2295	if (debug) {
2296		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2297			apm_info.bios.cseg, apm_info.bios.offset,
2298			apm_info.bios.cseg_16, apm_info.bios.dseg);
2299		if (apm_info.bios.version > 0x100)
2300			printk(" cseg len %x, dseg len %x",
2301				apm_info.bios.cseg_len,
2302				apm_info.bios.dseg_len);
2303		if (apm_info.bios.version > 0x101)
2304			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2305		printk("\n");
2306	}
2307
2308	if (apm_info.disabled) {
2309		pr_notice("disabled on user request.\n");
2310		return -ENODEV;
2311	}
2312	if ((num_online_cpus() > 1) && !power_off && !smp) {
2313		pr_notice("disabled - APM is not SMP safe.\n");
2314		apm_info.disabled = 1;
2315		return -ENODEV;
2316	}
2317	if (!acpi_disabled) {
2318		pr_notice("overridden by ACPI.\n");
2319		apm_info.disabled = 1;
2320		return -ENODEV;
2321	}
2322
2323	/*
2324	 * Set up the long jump entry point to the APM BIOS, which is called
2325	 * from inline assembly.
2326	 */
2327	apm_bios_entry.offset = apm_info.bios.offset;
2328	apm_bios_entry.segment = APM_CS;
2329
2330	/*
2331	 * The APM 1.1 BIOS is supposed to provide limit information that it
2332	 * recognizes.  Many machines do this correctly, but many others do
2333	 * not restrict themselves to their claimed limit.  When this happens,
2334	 * they will cause a segmentation violation in the kernel at boot time.
2335	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2336	 *
2337	 * Note we only set APM segments on CPU zero, since we pin the APM
2338	 * code to that CPU.
2339	 */
2340	gdt = get_cpu_gdt_rw(0);
2341	set_desc_base(&gdt[APM_CS >> 3],
2342		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2343	set_desc_base(&gdt[APM_CS_16 >> 3],
2344		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2345	set_desc_base(&gdt[APM_DS >> 3],
2346		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2347
2348	proc_create_single("apm", 0, NULL, proc_apm_show);
2349
2350	kapmd_task = kthread_create(apm, NULL, "kapmd");
2351	if (IS_ERR(kapmd_task)) {
2352		pr_err("disabled - Unable to start kernel thread\n");
2353		err = PTR_ERR(kapmd_task);
2354		kapmd_task = NULL;
2355		remove_proc_entry("apm", NULL);
2356		return err;
2357	}
2358	wake_up_process(kapmd_task);
2359
2360	if (num_online_cpus() > 1 && !smp) {
2361		printk(KERN_NOTICE
2362		       "apm: disabled - APM is not SMP safe (power off active).\n");
2363		return 0;
2364	}
2365
2366	/*
2367	 * Note we don't actually care if the misc_device cannot be registered.
2368	 * this driver can do its job without it, even if userspace can't
2369	 * control it.  just log the error
2370	 */
2371	if (misc_register(&apm_device))
2372		printk(KERN_WARNING "apm: Could not register misc device.\n");
2373
2374	if (HZ != 100)
2375		idle_period = (idle_period * HZ) / 100;
2376	if (idle_threshold < 100) {
2377		cpuidle_poll_state_init(&apm_idle_driver);
2378		if (!cpuidle_register_driver(&apm_idle_driver))
2379			if (cpuidle_register_device(&apm_cpuidle_device))
2380				cpuidle_unregister_driver(&apm_idle_driver);
2381	}
2382
2383	return 0;
2384}
2385
2386static void __exit apm_exit(void)
2387{
2388	int error;
2389
2390	cpuidle_unregister_device(&apm_cpuidle_device);
2391	cpuidle_unregister_driver(&apm_idle_driver);
2392
2393	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2394	    && (apm_info.connection_version > 0x0100)) {
2395		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2396		if (error)
2397			apm_error("disengage power management", error);
2398	}
2399	misc_deregister(&apm_device);
2400	remove_proc_entry("apm", NULL);
2401	if (power_off)
2402		pm_power_off = NULL;
2403	if (kapmd_task) {
2404		kthread_stop(kapmd_task);
2405		kapmd_task = NULL;
2406	}
2407}
2408
2409module_init(apm_init);
2410module_exit(apm_exit);
2411
2412MODULE_AUTHOR("Stephen Rothwell");
2413MODULE_DESCRIPTION("Advanced Power Management");
2414MODULE_LICENSE("GPL");
2415module_param(debug, bool, 0644);
2416MODULE_PARM_DESC(debug, "Enable debug mode");
2417module_param(power_off, bool, 0444);
2418MODULE_PARM_DESC(power_off, "Enable power off");
2419module_param(bounce_interval, int, 0444);
2420MODULE_PARM_DESC(bounce_interval,
2421		"Set the number of ticks to ignore suspend bounces");
2422module_param(allow_ints, bool, 0444);
2423MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2424module_param(broken_psr, bool, 0444);
2425MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2426module_param(realmode_power_off, bool, 0444);
2427MODULE_PARM_DESC(realmode_power_off,
2428		"Switch to real mode before powering off");
2429module_param(idle_threshold, int, 0444);
2430MODULE_PARM_DESC(idle_threshold,
2431	"System idle percentage above which to make APM BIOS idle calls");
2432module_param(idle_period, int, 0444);
2433MODULE_PARM_DESC(idle_period,
2434	"Period (in sec/100) over which to calculate the idle percentage");
2435module_param(smp, bool, 0444);
2436MODULE_PARM_DESC(smp,
2437	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2438MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
v6.2
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* -*- linux-c -*-
   3 * APM BIOS driver for Linux
   4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   5 *
   6 * Initial development of this driver was funded by NEC Australia P/L
   7 *	and NEC Corporation
   8 *
   9 * October 1995, Rik Faith (faith@cs.unc.edu):
  10 *    Minor enhancements and updates (to the patch set) for 1.3.x
  11 *    Documentation
  12 * January 1996, Rik Faith (faith@cs.unc.edu):
  13 *    Make /proc/apm easy to format (bump driver version)
  14 * March 1996, Rik Faith (faith@cs.unc.edu):
  15 *    Prohibit APM BIOS calls unless apm_enabled.
  16 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  18 *    Version 1.0 and 1.1
  19 * May 1996, Version 1.2
  20 * Feb 1998, Version 1.3
  21 * Feb 1998, Version 1.4
  22 * Aug 1998, Version 1.5
  23 * Sep 1998, Version 1.6
  24 * Nov 1998, Version 1.7
  25 * Jan 1999, Version 1.8
  26 * Jan 1999, Version 1.9
  27 * Oct 1999, Version 1.10
  28 * Nov 1999, Version 1.11
  29 * Jan 2000, Version 1.12
  30 * Feb 2000, Version 1.13
  31 * Nov 2000, Version 1.14
  32 * Oct 2001, Version 1.15
  33 * Jan 2002, Version 1.16
  34 * Oct 2002, Version 1.16ac
  35 *
  36 * History:
  37 *    0.6b: first version in official kernel, Linux 1.3.46
  38 *    0.7: changed /proc/apm format, Linux 1.3.58
  39 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  40 *    0.9: only call bios if bios is present, Linux 1.3.72
  41 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  42 *         Linux 1.3.85
  43 *    1.1: support user-space standby and suspend, power off after system
  44 *         halted, Linux 1.3.98
  45 *    1.2: When resetting RTC after resume, take care so that the time
  46 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  47 *         <jtoth@princeton.edu>); improve interaction between
  48 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  49 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  50 *	   levels to the printk calls. APM is not defined for SMP machines.
  51 *         The new replacement for it is, but Linux doesn't yet support this.
  52 *         Alan Cox Linux 2.1.55
  53 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  54 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  55 *         Dean Gaudet <dgaudet@arctic.org>.
  56 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  57 *    1.5: Fix segment register reloading (in case of bad segments saved
  58 *         across BIOS call).
  59 *         Stephen Rothwell
  60 *    1.6: Cope with compiler/assembler differences.
  61 *         Only try to turn off the first display device.
  62 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  63 *                   <echter@informatik.uni-rostock.de>
  64 *         Stephen Rothwell
  65 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  66 *         to reflect current state of APM BIOS.
  67 *         Chris Rankin <rankinc@bellsouth.net>
  68 *         Reset interrupt 0 timer to 100Hz after suspend
  69 *         Chad Miller <cmiller@surfsouth.com>
  70 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  71 *         Richard Gooch <rgooch@atnf.csiro.au>
  72 *         Allow boot time disabling of APM
  73 *         Make boot messages far less verbose by default
  74 *         Make asm safer
  75 *         Stephen Rothwell
  76 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  77 *         Richard Gooch <rgooch@atnf.csiro.au>
  78 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  79 *         remove dependency on CONFIG_PROC_FS
  80 *         Stephen Rothwell
  81 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  82 *         Try to cope with BIOS's that need to have all display
  83 *         devices blanked and not just the first one.
  84 *         Ross Paterson <ross@soi.city.ac.uk>
  85 *         Fix segment limit setting it has always been wrong as
  86 *         the segments needed to have byte granularity.
  87 *         Mark a few things __init.
  88 *         Add hack to allow power off of SMP systems by popular request.
  89 *         Use CONFIG_SMP instead of __SMP__
  90 *         Ignore BOUNCES for three seconds.
  91 *         Stephen Rothwell
  92 *   1.10: Fix for Thinkpad return code.
  93 *         Merge 2.2 and 2.3 drivers.
  94 *         Remove APM dependencies in arch/i386/kernel/process.c
  95 *         Remove APM dependencies in drivers/char/sysrq.c
  96 *         Reset time across standby.
  97 *         Allow more initialisation on SMP.
  98 *         Remove CONFIG_APM_POWER_OFF and make it boot time
  99 *         configurable (default on).
 100 *         Make debug only a boot time parameter (remove APM_DEBUG).
 101 *         Try to blank all devices on any error.
 102 *   1.11: Remove APM dependencies in drivers/char/console.c
 103 *         Check nr_running to detect if we are idle (from
 104 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 105 *         Fix for bioses that don't zero the top part of the
 106 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 107 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 108 *         Real mode power off patch (Walter Hofmann
 109 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 110 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 111 *         the code away anyway (smp_num_cpus == 1 in UP)
 112 *         noted by Artur Skawina <skawina@geocities.com>.
 113 *         Make power off under SMP work again.
 114 *         Fix thinko with initial engaging of BIOS.
 115 *         Make sure power off only happens on CPU 0
 116 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 117 *         Do error notification to user mode if BIOS calls fail.
 118 *         Move entrypoint offset fix to ...boot/setup.S
 119 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 120 *         Remove smp-power-off. SMP users must now specify
 121 *         "apm=power-off" on the kernel command line. Suggested
 122 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 123 *         <alan@lxorguk.ukuu.org.uk>.
 124 *         Register the /proc/apm entry even on SMP so that
 125 *         scripts that check for it before doing power off
 126 *         work (Jim Avera <jima@hal.com>).
 127 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 128 *         <andy_henroid@yahoo.com>).
 129 *         Modularize the code.
 130 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 131 *         is now the way life works).
 132 *         Fix thinko in suspend() (wrong return).
 133 *         Notify drivers on critical suspend.
 134 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 135 *         modified by sfr).
 136 *         Disable interrupts while we are suspended (Andy Henroid
 137 *         <andy_henroid@yahoo.com> fixed by sfr).
 138 *         Make power off work on SMP again (Tony Hoyle
 139 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 140 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 141 *         interval is now configurable.
 142 *   1.14: Make connection version persist across module unload/load.
 143 *         Enable and engage power management earlier.
 144 *         Disengage power management on module unload.
 145 *         Changed to use the sysrq-register hack for registering the
 146 *         power off function called by magic sysrq based upon discussions
 147 *         in irc://irc.openprojects.net/#kernelnewbies
 148 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 149 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 150 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 151 *         Work around byte swap bug in one of the Vaio's BIOS's
 152 *         (Marc Boucher <marc@mbsi.ca>).
 153 *         Exposed the disable flag to dmi so that we can handle known
 154 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 155 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 156 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 157 *         If an APM idle fails log it and idle sensibly
 158 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 159 *         Don't expect replies from clients who open the device O_RDONLY.
 160 *         (Idea from Thomas Hood)
 161 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 162 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 163 *         Notify listeners of standby or suspend events before notifying
 164 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 165 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 166 *         Ignore first resume after we generate our own resume event
 167 *         after a suspend (Thomas Hood)
 168 *         Daemonize now gets rid of our controlling terminal (sfr).
 169 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 170 *         idle_threshold (sfr).
 171 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 172 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 173 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 174 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 175 *
 176 * APM 1.1 Reference:
 177 *
 178 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 179 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 180 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 181 *
 182 * [This document is available free from Intel by calling 800.628.8686 (fax
 183 * 916.356.6100) or 800.548.4725; or from
 184 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 185 * available from Microsoft by calling 206.882.8080.]
 186 *
 187 * APM 1.2 Reference:
 188 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 189 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 190 *
 191 * [This document is available from Microsoft at:
 192 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 193 */
 194
 195#define pr_fmt(fmt) "apm: " fmt
 196
 197#include <linux/module.h>
 198
 199#include <linux/poll.h>
 200#include <linux/types.h>
 201#include <linux/stddef.h>
 202#include <linux/timer.h>
 203#include <linux/fcntl.h>
 204#include <linux/slab.h>
 205#include <linux/stat.h>
 206#include <linux/proc_fs.h>
 207#include <linux/seq_file.h>
 208#include <linux/miscdevice.h>
 209#include <linux/apm_bios.h>
 210#include <linux/init.h>
 211#include <linux/time.h>
 212#include <linux/sched/signal.h>
 213#include <linux/sched/cputime.h>
 214#include <linux/pm.h>
 215#include <linux/capability.h>
 216#include <linux/device.h>
 217#include <linux/kernel.h>
 218#include <linux/freezer.h>
 219#include <linux/smp.h>
 220#include <linux/dmi.h>
 221#include <linux/suspend.h>
 222#include <linux/kthread.h>
 223#include <linux/jiffies.h>
 224#include <linux/acpi.h>
 225#include <linux/syscore_ops.h>
 226#include <linux/i8253.h>
 227#include <linux/cpuidle.h>
 228
 229#include <linux/uaccess.h>
 230#include <asm/desc.h>
 231#include <asm/olpc.h>
 232#include <asm/paravirt.h>
 233#include <asm/reboot.h>
 234#include <asm/nospec-branch.h>
 235#include <asm/ibt.h>
 236
 237#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 238extern int (*console_blank_hook)(int);
 239#endif
 240
 241/*
 242 * The apm_bios device is one of the misc char devices.
 243 * This is its minor number.
 244 */
 245#define	APM_MINOR_DEV	134
 246
 247/*
 248 * Various options can be changed at boot time as follows:
 249 * (We allow underscores for compatibility with the modules code)
 250 *	apm=on/off			enable/disable APM
 251 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 252 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 253 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 254 *	    					powering off
 255 *	    [no-]debug			log some debugging messages
 256 *	    [no-]power[-_]off		power off on shutdown
 257 *	    [no-]smp			Use apm even on an SMP box
 258 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 259 *	    				bounces
 260 *          idle[-_]threshold=<n>       System idle percentage above which to
 261 *                                      make APM BIOS idle calls. Set it to
 262 *                                      100 to disable.
 263 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 264 *                                      which the idle percentage is
 265 *                                      calculated.
 266 */
 267
 268/* KNOWN PROBLEM MACHINES:
 269 *
 270 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 271 *                         [Confirmed by TI representative]
 272 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 273 *                    [Confirmed by BIOS disassembly]
 274 *                    [This may work now ...]
 275 * P: Toshiba 1950S: battery life information only gets updated after resume
 276 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 277 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 278 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 279 * 	Neale Banks <neale@lowendale.com.au> December 2000
 280 *
 281 * Legend: U = unusable with APM patches
 282 *         P = partially usable with APM patches
 283 */
 284
 285/*
 286 * Define as 1 to make the driver always call the APM BIOS busy
 287 * routine even if the clock was not reported as slowed by the
 288 * idle routine.  Otherwise, define as 0.
 289 */
 290#define ALWAYS_CALL_BUSY   1
 291
 292/*
 293 * Define to make the APM BIOS calls zero all data segment registers (so
 294 * that an incorrect BIOS implementation will cause a kernel panic if it
 295 * tries to write to arbitrary memory).
 296 */
 297#define APM_ZERO_SEGS
 298
 299#include <asm/apm.h>
 300
 301/*
 302 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 303 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 304 * David Chen <chen@ctpa04.mit.edu>
 305 */
 306#undef INIT_TIMER_AFTER_SUSPEND
 307
 308#ifdef INIT_TIMER_AFTER_SUSPEND
 309#include <linux/timex.h>
 310#include <asm/io.h>
 311#include <linux/delay.h>
 312#endif
 313
 314/*
 315 * Need to poll the APM BIOS every second
 316 */
 317#define APM_CHECK_TIMEOUT	(HZ)
 318
 319/*
 320 * Ignore suspend events for this amount of time after a resume
 321 */
 322#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 323
 324/*
 325 * Maximum number of events stored
 326 */
 327#define APM_MAX_EVENTS		20
 328
 329/*
 330 * The per-file APM data
 331 */
 332struct apm_user {
 333	int		magic;
 334	struct apm_user *next;
 335	unsigned int	suser: 1;
 336	unsigned int	writer: 1;
 337	unsigned int	reader: 1;
 338	unsigned int	suspend_wait: 1;
 339	int		suspend_result;
 340	int		suspends_pending;
 341	int		standbys_pending;
 342	int		suspends_read;
 343	int		standbys_read;
 344	int		event_head;
 345	int		event_tail;
 346	apm_event_t	events[APM_MAX_EVENTS];
 347};
 348
 349/*
 350 * The magic number in apm_user
 351 */
 352#define APM_BIOS_MAGIC		0x4101
 353
 354/*
 355 * idle percentage above which bios idle calls are done
 356 */
 357#ifdef CONFIG_APM_CPU_IDLE
 358#define DEFAULT_IDLE_THRESHOLD	95
 359#else
 360#define DEFAULT_IDLE_THRESHOLD	100
 361#endif
 362#define DEFAULT_IDLE_PERIOD	(100 / 3)
 363
 364static int apm_cpu_idle(struct cpuidle_device *dev,
 365			struct cpuidle_driver *drv, int index);
 366
 367static struct cpuidle_driver apm_idle_driver = {
 368	.name = "apm_idle",
 369	.owner = THIS_MODULE,
 370	.states = {
 371		{ /* entry 0 is for polling */ },
 372		{ /* entry 1 is for APM idle */
 373			.name = "APM",
 374			.desc = "APM idle",
 375			.exit_latency = 250,	/* WAG */
 376			.target_residency = 500,	/* WAG */
 377			.enter = &apm_cpu_idle
 378		},
 379	},
 380	.state_count = 2,
 381};
 382
 383static struct cpuidle_device apm_cpuidle_device;
 384
 385/*
 386 * Local variables
 387 */
 388__visible struct {
 389	unsigned long	offset;
 390	unsigned short	segment;
 391} apm_bios_entry;
 392static int clock_slowed;
 393static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 394static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 395static int suspends_pending;
 396static int standbys_pending;
 397static int ignore_sys_suspend;
 398static int ignore_normal_resume;
 399static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 400
 401static bool debug __read_mostly;
 402static bool smp __read_mostly;
 403static int apm_disabled = -1;
 404#ifdef CONFIG_SMP
 405static bool power_off;
 406#else
 407static bool power_off = 1;
 408#endif
 409static bool realmode_power_off;
 410#ifdef CONFIG_APM_ALLOW_INTS
 411static bool allow_ints = 1;
 412#else
 413static bool allow_ints;
 414#endif
 415static bool broken_psr;
 416
 417static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 418static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 419static struct apm_user *user_list;
 420static DEFINE_SPINLOCK(user_list_lock);
 421static DEFINE_MUTEX(apm_mutex);
 422
 423/*
 424 * Set up a segment that references the real mode segment 0x40
 425 * that extends up to the end of page zero (that we have reserved).
 426 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 427 * even though they are called in protected mode.
 428 */
 429static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
 430			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 431
 432static const char driver_version[] = "1.16ac";	/* no spaces */
 433
 434static struct task_struct *kapmd_task;
 435
 436/*
 437 *	APM event names taken from the APM 1.2 specification. These are
 438 *	the message codes that the BIOS uses to tell us about events
 439 */
 440static const char * const apm_event_name[] = {
 441	"system standby",
 442	"system suspend",
 443	"normal resume",
 444	"critical resume",
 445	"low battery",
 446	"power status change",
 447	"update time",
 448	"critical suspend",
 449	"user standby",
 450	"user suspend",
 451	"system standby resume",
 452	"capabilities change"
 453};
 454#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 455
 456typedef struct lookup_t {
 457	int	key;
 458	char 	*msg;
 459} lookup_t;
 460
 461/*
 462 *	The BIOS returns a set of standard error codes in AX when the
 463 *	carry flag is set.
 464 */
 465
 466static const lookup_t error_table[] = {
 467/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 468	{ APM_DISABLED,		"Power management disabled" },
 469	{ APM_CONNECTED,	"Real mode interface already connected" },
 470	{ APM_NOT_CONNECTED,	"Interface not connected" },
 471	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 472/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 473	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 474	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 475	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 476	{ APM_BAD_PARAM,	"Parameter out of range" },
 477	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 478	{ APM_BAD_FUNCTION,     "Function not supported" },
 479	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 480	{ APM_BAD_STATE,	"Unable to enter requested state" },
 481/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 482	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 483	{ APM_NOT_PRESENT,	"No APM present" }
 484};
 485#define ERROR_COUNT	ARRAY_SIZE(error_table)
 486
 487/**
 488 *	apm_error	-	display an APM error
 489 *	@str: information string
 490 *	@err: APM BIOS return code
 491 *
 492 *	Write a meaningful log entry to the kernel log in the event of
 493 *	an APM error.  Note that this also handles (negative) kernel errors.
 494 */
 495
 496static void apm_error(char *str, int err)
 497{
 498	int i;
 499
 500	for (i = 0; i < ERROR_COUNT; i++)
 501		if (error_table[i].key == err)
 502			break;
 503	if (i < ERROR_COUNT)
 504		pr_notice("%s: %s\n", str, error_table[i].msg);
 505	else if (err < 0)
 506		pr_notice("%s: linux error code %i\n", str, err);
 507	else
 508		pr_notice("%s: unknown error code %#2.2x\n",
 509		       str, err);
 510}
 511
 512/*
 513 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 514 * apm_info.allow_ints, we are being really paranoid here!  Not only
 515 * are interrupts disabled, but all the segment registers (except SS)
 516 * are saved and zeroed this means that if the BIOS tries to reference
 517 * any data without explicitly loading the segment registers, the kernel
 518 * will fault immediately rather than have some unforeseen circumstances
 519 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 520 * this depends on CS referring to the same physical memory as DS so that
 521 * DS can be zeroed before the call. Unfortunately, we can't do anything
 522 * about the stack segment/pointer.  Also, we tell the compiler that
 523 * everything could change.
 524 *
 525 * Also, we KNOW that for the non error case of apm_bios_call, there
 526 * is no useful data returned in the low order 8 bits of eax.
 527 */
 528
 529static inline unsigned long __apm_irq_save(void)
 530{
 531	unsigned long flags;
 532	local_save_flags(flags);
 533	if (apm_info.allow_ints) {
 534		if (irqs_disabled_flags(flags))
 535			local_irq_enable();
 536	} else
 537		local_irq_disable();
 538
 539	return flags;
 540}
 541
 542#define apm_irq_save(flags) \
 543	do { flags = __apm_irq_save(); } while (0)
 544
 545static inline void apm_irq_restore(unsigned long flags)
 546{
 547	if (irqs_disabled_flags(flags))
 548		local_irq_disable();
 549	else if (irqs_disabled())
 550		local_irq_enable();
 551}
 552
 553#ifdef APM_ZERO_SEGS
 554#	define APM_DECL_SEGS \
 555		unsigned int saved_fs; unsigned int saved_gs;
 556#	define APM_DO_SAVE_SEGS \
 557		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 558#	define APM_DO_RESTORE_SEGS \
 559		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 560#else
 561#	define APM_DECL_SEGS
 562#	define APM_DO_SAVE_SEGS
 563#	define APM_DO_RESTORE_SEGS
 564#endif
 565
 566struct apm_bios_call {
 567	u32 func;
 568	/* In and out */
 569	u32 ebx;
 570	u32 ecx;
 571	/* Out only */
 572	u32 eax;
 573	u32 edx;
 574	u32 esi;
 575
 576	/* Error: -ENOMEM, or bits 8-15 of eax */
 577	int err;
 578};
 579
 580/**
 581 *	__apm_bios_call - Make an APM BIOS 32bit call
 582 *	@_call: pointer to struct apm_bios_call.
 583 *
 584 *	Make an APM call using the 32bit protected mode interface. The
 585 *	caller is responsible for knowing if APM BIOS is configured and
 586 *	enabled. This call can disable interrupts for a long period of
 587 *	time on some laptops.  The return value is in AH and the carry
 588 *	flag is loaded into AL.  If there is an error, then the error
 589 *	code is returned in AH (bits 8-15 of eax) and this function
 590 *	returns non-zero.
 591 *
 592 *	Note: this makes the call on the current CPU.
 593 */
 594static long __apm_bios_call(void *_call)
 595{
 596	APM_DECL_SEGS
 597	unsigned long		flags;
 598	int			cpu;
 599	struct desc_struct	save_desc_40;
 600	struct desc_struct	*gdt;
 601	struct apm_bios_call	*call = _call;
 602	u64			ibt;
 603
 604	cpu = get_cpu();
 605	BUG_ON(cpu != 0);
 606	gdt = get_cpu_gdt_rw(cpu);
 607	save_desc_40 = gdt[0x40 / 8];
 608	gdt[0x40 / 8] = bad_bios_desc;
 609
 610	apm_irq_save(flags);
 611	firmware_restrict_branch_speculation_start();
 612	ibt = ibt_save();
 613	APM_DO_SAVE_SEGS;
 614	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 615			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 616			  &call->esi);
 617	APM_DO_RESTORE_SEGS;
 618	ibt_restore(ibt);
 619	firmware_restrict_branch_speculation_end();
 620	apm_irq_restore(flags);
 621	gdt[0x40 / 8] = save_desc_40;
 622	put_cpu();
 623
 624	return call->eax & 0xff;
 625}
 626
 627/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 628static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 629{
 630	int ret;
 631
 632	/* Don't bother with work_on_cpu in the common case, so we don't
 633	 * have to worry about OOM or overhead. */
 634	if (get_cpu() == 0) {
 635		ret = fn(call);
 636		put_cpu();
 637	} else {
 638		put_cpu();
 639		ret = work_on_cpu(0, fn, call);
 640	}
 641
 642	/* work_on_cpu can fail with -ENOMEM */
 643	if (ret < 0)
 644		call->err = ret;
 645	else
 646		call->err = (call->eax >> 8) & 0xff;
 647
 648	return ret;
 649}
 650
 651/**
 652 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 653 *	@call: the apm_bios_call registers.
 654 *
 655 *	If there is an error, it is returned in @call.err.
 656 */
 657static int apm_bios_call(struct apm_bios_call *call)
 658{
 659	return on_cpu0(__apm_bios_call, call);
 660}
 661
 662/**
 663 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 664 *	@_call: pointer to struct apm_bios_call.
 665 *
 666 *	Make a BIOS call that returns one value only, or just status.
 667 *	If there is an error, then the error code is returned in AH
 668 *	(bits 8-15 of eax) and this function returns non-zero (it can
 669 *	also return -ENOMEM). This is used for simpler BIOS operations.
 670 *	This call may hold interrupts off for a long time on some laptops.
 671 *
 672 *	Note: this makes the call on the current CPU.
 673 */
 674static long __apm_bios_call_simple(void *_call)
 675{
 676	u8			error;
 677	APM_DECL_SEGS
 678	unsigned long		flags;
 679	int			cpu;
 680	struct desc_struct	save_desc_40;
 681	struct desc_struct	*gdt;
 682	struct apm_bios_call	*call = _call;
 683	u64			ibt;
 684
 685	cpu = get_cpu();
 686	BUG_ON(cpu != 0);
 687	gdt = get_cpu_gdt_rw(cpu);
 688	save_desc_40 = gdt[0x40 / 8];
 689	gdt[0x40 / 8] = bad_bios_desc;
 690
 691	apm_irq_save(flags);
 692	firmware_restrict_branch_speculation_start();
 693	ibt = ibt_save();
 694	APM_DO_SAVE_SEGS;
 695	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 696					 &call->eax);
 697	APM_DO_RESTORE_SEGS;
 698	ibt_restore(ibt);
 699	firmware_restrict_branch_speculation_end();
 700	apm_irq_restore(flags);
 701	gdt[0x40 / 8] = save_desc_40;
 702	put_cpu();
 703	return error;
 704}
 705
 706/**
 707 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 708 *	@func: APM function to invoke
 709 *	@ebx_in: EBX register value for BIOS call
 710 *	@ecx_in: ECX register value for BIOS call
 711 *	@eax: EAX register on return from the BIOS call
 712 *	@err: bits
 713 *
 714 *	Make a BIOS call that returns one value only, or just status.
 715 *	If there is an error, then the error code is returned in @err
 716 *	and this function returns non-zero. This is used for simpler
 717 *	BIOS operations.  This call may hold interrupts off for a long
 718 *	time on some laptops.
 719 */
 720static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 721				int *err)
 722{
 723	struct apm_bios_call call;
 724	int ret;
 725
 726	call.func = func;
 727	call.ebx = ebx_in;
 728	call.ecx = ecx_in;
 729
 730	ret = on_cpu0(__apm_bios_call_simple, &call);
 731	*eax = call.eax;
 732	*err = call.err;
 733	return ret;
 734}
 735
 736/**
 737 *	apm_driver_version	-	APM driver version
 738 *	@val:	loaded with the APM version on return
 739 *
 740 *	Retrieve the APM version supported by the BIOS. This is only
 741 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 742 *	probably present.
 743 *
 744 *	On entry val should point to a value indicating the APM driver
 745 *	version with the high byte being the major and the low byte the
 746 *	minor number both in BCD
 747 *
 748 *	On return it will hold the BIOS revision supported in the
 749 *	same format.
 750 */
 751
 752static int apm_driver_version(u_short *val)
 753{
 754	u32 eax;
 755	int err;
 756
 757	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 758		return err;
 759	*val = eax;
 760	return APM_SUCCESS;
 761}
 762
 763/**
 764 *	apm_get_event	-	get an APM event from the BIOS
 765 *	@event: pointer to the event
 766 *	@info: point to the event information
 767 *
 768 *	The APM BIOS provides a polled information for event
 769 *	reporting. The BIOS expects to be polled at least every second
 770 *	when events are pending. When a message is found the caller should
 771 *	poll until no more messages are present.  However, this causes
 772 *	problems on some laptops where a suspend event notification is
 773 *	not cleared until it is acknowledged.
 774 *
 775 *	Additional information is returned in the info pointer, providing
 776 *	that APM 1.2 is in use. If no messages are pending the value 0x80
 777 *	is returned (No power management events pending).
 778 */
 779static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 780{
 781	struct apm_bios_call call;
 782
 783	call.func = APM_FUNC_GET_EVENT;
 784	call.ebx = call.ecx = 0;
 785
 786	if (apm_bios_call(&call))
 787		return call.err;
 788
 789	*event = call.ebx;
 790	if (apm_info.connection_version < 0x0102)
 791		*info = ~0; /* indicate info not valid */
 792	else
 793		*info = call.ecx;
 794	return APM_SUCCESS;
 795}
 796
 797/**
 798 *	set_power_state	-	set the power management state
 799 *	@what: which items to transition
 800 *	@state: state to transition to
 801 *
 802 *	Request an APM change of state for one or more system devices. The
 803 *	processor state must be transitioned last of all. what holds the
 804 *	class of device in the upper byte and the device number (0xFF for
 805 *	all) for the object to be transitioned.
 806 *
 807 *	The state holds the state to transition to, which may in fact
 808 *	be an acceptance of a BIOS requested state change.
 809 */
 810
 811static int set_power_state(u_short what, u_short state)
 812{
 813	u32 eax;
 814	int err;
 815
 816	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 817		return err;
 818	return APM_SUCCESS;
 819}
 820
 821/**
 822 *	set_system_power_state - set system wide power state
 823 *	@state: which state to enter
 824 *
 825 *	Transition the entire system into a new APM power state.
 826 */
 827
 828static int set_system_power_state(u_short state)
 829{
 830	return set_power_state(APM_DEVICE_ALL, state);
 831}
 832
 833/**
 834 *	apm_do_idle	-	perform power saving
 835 *
 836 *	This function notifies the BIOS that the processor is (in the view
 837 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 838 *	to handle the idle request. On a success the function returns 1
 839 *	if the BIOS did clock slowing or 0 otherwise.
 840 */
 841
 842static int apm_do_idle(void)
 843{
 844	u32 eax;
 845	u8 ret = 0;
 846	int idled = 0;
 847	int err = 0;
 848
 849	if (!need_resched()) {
 850		idled = 1;
 851		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 852	}
 853
 854	if (!idled)
 855		return 0;
 856
 857	if (ret) {
 858		static unsigned long t;
 859
 860		/* This always fails on some SMP boards running UP kernels.
 861		 * Only report the failure the first 5 times.
 862		 */
 863		if (++t < 5) {
 864			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 865			t = jiffies;
 866		}
 867		return -1;
 868	}
 869	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 870	return clock_slowed;
 871}
 872
 873/**
 874 *	apm_do_busy	-	inform the BIOS the CPU is busy
 875 *
 876 *	Request that the BIOS brings the CPU back to full performance.
 877 */
 878
 879static void apm_do_busy(void)
 880{
 881	u32 dummy;
 882	int err;
 883
 884	if (clock_slowed || ALWAYS_CALL_BUSY) {
 885		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 886		clock_slowed = 0;
 887	}
 888}
 889
 890/*
 891 * If no process has really been interested in
 892 * the CPU for some time, we want to call BIOS
 893 * power management - we probably want
 894 * to conserve power.
 895 */
 896#define IDLE_CALC_LIMIT	(HZ * 100)
 897#define IDLE_LEAKY_MAX	16
 898
 899/**
 900 * apm_cpu_idle		-	cpu idling for APM capable Linux
 901 *
 902 * This is the idling function the kernel executes when APM is available. It
 903 * tries to do BIOS powermanagement based on the average system idle time.
 904 * Furthermore it calls the system default idle routine.
 905 */
 906
 907static int apm_cpu_idle(struct cpuidle_device *dev,
 908	struct cpuidle_driver *drv, int index)
 909{
 910	static int use_apm_idle; /* = 0 */
 911	static unsigned int last_jiffies; /* = 0 */
 912	static u64 last_stime; /* = 0 */
 913	u64 stime, utime;
 914
 915	int apm_idle_done = 0;
 916	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 917	unsigned int bucket;
 918
 919recalc:
 920	task_cputime(current, &utime, &stime);
 921	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 922		use_apm_idle = 0;
 923	} else if (jiffies_since_last_check > idle_period) {
 924		unsigned int idle_percentage;
 925
 926		idle_percentage = nsecs_to_jiffies(stime - last_stime);
 927		idle_percentage *= 100;
 928		idle_percentage /= jiffies_since_last_check;
 929		use_apm_idle = (idle_percentage > idle_threshold);
 930		if (apm_info.forbid_idle)
 931			use_apm_idle = 0;
 932	}
 933
 934	last_jiffies = jiffies;
 935	last_stime = stime;
 936
 937	bucket = IDLE_LEAKY_MAX;
 938
 939	while (!need_resched()) {
 940		if (use_apm_idle) {
 941			unsigned int t;
 942
 943			t = jiffies;
 944			switch (apm_do_idle()) {
 945			case 0:
 946				apm_idle_done = 1;
 947				if (t != jiffies) {
 948					if (bucket) {
 949						bucket = IDLE_LEAKY_MAX;
 950						continue;
 951					}
 952				} else if (bucket) {
 953					bucket--;
 954					continue;
 955				}
 956				break;
 957			case 1:
 958				apm_idle_done = 1;
 959				break;
 960			default: /* BIOS refused */
 961				break;
 962			}
 963		}
 964		default_idle();
 965		local_irq_disable();
 966		jiffies_since_last_check = jiffies - last_jiffies;
 967		if (jiffies_since_last_check > idle_period)
 968			goto recalc;
 969	}
 970
 971	if (apm_idle_done)
 972		apm_do_busy();
 973
 974	return index;
 975}
 976
 977/**
 978 *	apm_power_off	-	ask the BIOS to power off
 979 *
 980 *	Handle the power off sequence. This is the one piece of code we
 981 *	will execute even on SMP machines. In order to deal with BIOS
 982 *	bugs we support real mode APM BIOS power off calls. We also make
 983 *	the SMP call on CPU0 as some systems will only honour this call
 984 *	on their first cpu.
 985 */
 986
 987static void apm_power_off(void)
 988{
 989	/* Some bioses don't like being called from CPU != 0 */
 990	if (apm_info.realmode_power_off) {
 991		set_cpus_allowed_ptr(current, cpumask_of(0));
 992		machine_real_restart(MRR_APM);
 993	} else {
 994		(void)set_system_power_state(APM_STATE_OFF);
 995	}
 996}
 997
 998#ifdef CONFIG_APM_DO_ENABLE
 999
1000/**
1001 *	apm_enable_power_management - enable BIOS APM power management
1002 *	@enable: enable yes/no
1003 *
1004 *	Enable or disable the APM BIOS power services.
1005 */
1006
1007static int apm_enable_power_management(int enable)
1008{
1009	u32 eax;
1010	int err;
1011
1012	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1013		return APM_NOT_ENGAGED;
1014	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1015				 enable, &eax, &err))
1016		return err;
1017	if (enable)
1018		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1019	else
1020		apm_info.bios.flags |= APM_BIOS_DISABLED;
1021	return APM_SUCCESS;
1022}
1023#endif
1024
1025/**
1026 *	apm_get_power_status	-	get current power state
1027 *	@status: returned status
1028 *	@bat: battery info
1029 *	@life: estimated life
1030 *
1031 *	Obtain the current power status from the APM BIOS. We return a
1032 *	status which gives the rough battery status, and current power
1033 *	source. The bat value returned give an estimate as a percentage
1034 *	of life and a status value for the battery. The estimated life
1035 *	if reported is a lifetime in seconds/minutes at current power
1036 *	consumption.
1037 */
1038
1039static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1040{
1041	struct apm_bios_call call;
1042
1043	call.func = APM_FUNC_GET_STATUS;
1044	call.ebx = APM_DEVICE_ALL;
1045	call.ecx = 0;
1046
1047	if (apm_info.get_power_status_broken)
1048		return APM_32_UNSUPPORTED;
1049	if (apm_bios_call(&call)) {
1050		if (!call.err)
1051			return APM_NO_ERROR;
1052		return call.err;
1053	}
1054	*status = call.ebx;
1055	*bat = call.ecx;
1056	if (apm_info.get_power_status_swabinminutes) {
1057		*life = swab16((u16)call.edx);
1058		*life |= 0x8000;
1059	} else
1060		*life = call.edx;
1061	return APM_SUCCESS;
1062}
1063
1064#if 0
1065static int apm_get_battery_status(u_short which, u_short *status,
1066				  u_short *bat, u_short *life, u_short *nbat)
1067{
1068	u32 eax;
1069	u32 ebx;
1070	u32 ecx;
1071	u32 edx;
1072	u32 esi;
1073
1074	if (apm_info.connection_version < 0x0102) {
1075		/* pretend we only have one battery. */
1076		if (which != 1)
1077			return APM_BAD_DEVICE;
1078		*nbat = 1;
1079		return apm_get_power_status(status, bat, life);
1080	}
1081
1082	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1083			  &ebx, &ecx, &edx, &esi))
1084		return (eax >> 8) & 0xff;
1085	*status = ebx;
1086	*bat = ecx;
1087	*life = edx;
1088	*nbat = esi;
1089	return APM_SUCCESS;
1090}
1091#endif
1092
1093/**
1094 *	apm_engage_power_management	-	enable PM on a device
1095 *	@device: identity of device
1096 *	@enable: on/off
1097 *
1098 *	Activate or deactivate power management on either a specific device
1099 *	or the entire system (%APM_DEVICE_ALL).
1100 */
1101
1102static int apm_engage_power_management(u_short device, int enable)
1103{
1104	u32 eax;
1105	int err;
1106
1107	if ((enable == 0) && (device == APM_DEVICE_ALL)
1108	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1109		return APM_DISABLED;
1110	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1111				 &eax, &err))
1112		return err;
1113	if (device == APM_DEVICE_ALL) {
1114		if (enable)
1115			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1116		else
1117			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1118	}
1119	return APM_SUCCESS;
1120}
1121
1122#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1123
1124/**
1125 *	apm_console_blank	-	blank the display
1126 *	@blank: on/off
1127 *
1128 *	Attempt to blank the console, firstly by blanking just video device
1129 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1130 *	all video devices. Typically the BIOS will do laptop backlight and
1131 *	monitor powerdown for us.
1132 */
1133
1134static int apm_console_blank(int blank)
1135{
1136	int error = APM_NOT_ENGAGED; /* silence gcc */
1137	int i;
1138	u_short state;
1139	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1140
1141	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1142
1143	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1144		error = set_power_state(dev[i], state);
1145
1146		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1147			return 1;
1148
1149		if (error == APM_NOT_ENGAGED)
1150			break;
1151	}
1152
1153	if (error == APM_NOT_ENGAGED) {
1154		static int tried;
1155		int eng_error;
1156		if (tried++ == 0) {
1157			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1158			if (eng_error) {
1159				apm_error("set display", error);
1160				apm_error("engage interface", eng_error);
1161				return 0;
1162			} else
1163				return apm_console_blank(blank);
1164		}
1165	}
1166	apm_error("set display", error);
1167	return 0;
1168}
1169#endif
1170
1171static int queue_empty(struct apm_user *as)
1172{
1173	return as->event_head == as->event_tail;
1174}
1175
1176static apm_event_t get_queued_event(struct apm_user *as)
1177{
1178	if (++as->event_tail >= APM_MAX_EVENTS)
1179		as->event_tail = 0;
1180	return as->events[as->event_tail];
1181}
1182
1183static void queue_event(apm_event_t event, struct apm_user *sender)
1184{
1185	struct apm_user *as;
1186
1187	spin_lock(&user_list_lock);
1188	if (user_list == NULL)
1189		goto out;
1190	for (as = user_list; as != NULL; as = as->next) {
1191		if ((as == sender) || (!as->reader))
1192			continue;
1193		if (++as->event_head >= APM_MAX_EVENTS)
1194			as->event_head = 0;
1195
1196		if (as->event_head == as->event_tail) {
1197			static int notified;
1198
1199			if (notified++ == 0)
1200				pr_err("an event queue overflowed\n");
1201			if (++as->event_tail >= APM_MAX_EVENTS)
1202				as->event_tail = 0;
1203		}
1204		as->events[as->event_head] = event;
1205		if (!as->suser || !as->writer)
1206			continue;
1207		switch (event) {
1208		case APM_SYS_SUSPEND:
1209		case APM_USER_SUSPEND:
1210			as->suspends_pending++;
1211			suspends_pending++;
1212			break;
1213
1214		case APM_SYS_STANDBY:
1215		case APM_USER_STANDBY:
1216			as->standbys_pending++;
1217			standbys_pending++;
1218			break;
1219		}
1220	}
1221	wake_up_interruptible(&apm_waitqueue);
1222out:
1223	spin_unlock(&user_list_lock);
1224}
1225
1226static void reinit_timer(void)
1227{
1228#ifdef INIT_TIMER_AFTER_SUSPEND
1229	unsigned long flags;
1230
1231	raw_spin_lock_irqsave(&i8253_lock, flags);
1232	/* set the clock to HZ */
1233	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1234	udelay(10);
1235	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1236	udelay(10);
1237	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1238	udelay(10);
1239	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1240#endif
1241}
1242
1243static int suspend(int vetoable)
1244{
1245	int err;
1246	struct apm_user	*as;
1247
1248	dpm_suspend_start(PMSG_SUSPEND);
1249	dpm_suspend_end(PMSG_SUSPEND);
1250
1251	local_irq_disable();
1252	syscore_suspend();
1253
1254	local_irq_enable();
1255
1256	save_processor_state();
1257	err = set_system_power_state(APM_STATE_SUSPEND);
1258	ignore_normal_resume = 1;
1259	restore_processor_state();
1260
1261	local_irq_disable();
1262	reinit_timer();
1263
1264	if (err == APM_NO_ERROR)
1265		err = APM_SUCCESS;
1266	if (err != APM_SUCCESS)
1267		apm_error("suspend", err);
1268	err = (err == APM_SUCCESS) ? 0 : -EIO;
1269
1270	syscore_resume();
1271	local_irq_enable();
1272
1273	dpm_resume_start(PMSG_RESUME);
1274	dpm_resume_end(PMSG_RESUME);
1275
1276	queue_event(APM_NORMAL_RESUME, NULL);
1277	spin_lock(&user_list_lock);
1278	for (as = user_list; as != NULL; as = as->next) {
1279		as->suspend_wait = 0;
1280		as->suspend_result = err;
1281	}
1282	spin_unlock(&user_list_lock);
1283	wake_up_interruptible(&apm_suspend_waitqueue);
1284	return err;
1285}
1286
1287static void standby(void)
1288{
1289	int err;
1290
1291	dpm_suspend_end(PMSG_SUSPEND);
1292
1293	local_irq_disable();
1294	syscore_suspend();
1295	local_irq_enable();
1296
1297	err = set_system_power_state(APM_STATE_STANDBY);
1298	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1299		apm_error("standby", err);
1300
1301	local_irq_disable();
1302	syscore_resume();
1303	local_irq_enable();
1304
1305	dpm_resume_start(PMSG_RESUME);
1306}
1307
1308static apm_event_t get_event(void)
1309{
1310	int error;
1311	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1312	apm_eventinfo_t	info;
1313
1314	static int notified;
1315
1316	/* we don't use the eventinfo */
1317	error = apm_get_event(&event, &info);
1318	if (error == APM_SUCCESS)
1319		return event;
1320
1321	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1322		apm_error("get_event", error);
1323
1324	return 0;
1325}
1326
1327static void check_events(void)
1328{
1329	apm_event_t event;
1330	static unsigned long last_resume;
1331	static int ignore_bounce;
1332
1333	while ((event = get_event()) != 0) {
1334		if (debug) {
1335			if (event <= NR_APM_EVENT_NAME)
1336				printk(KERN_DEBUG "apm: received %s notify\n",
1337				       apm_event_name[event - 1]);
1338			else
1339				printk(KERN_DEBUG "apm: received unknown "
1340				       "event 0x%02x\n", event);
1341		}
1342		if (ignore_bounce
1343		    && (time_after(jiffies, last_resume + bounce_interval)))
1344			ignore_bounce = 0;
1345
1346		switch (event) {
1347		case APM_SYS_STANDBY:
1348		case APM_USER_STANDBY:
1349			queue_event(event, NULL);
1350			if (standbys_pending <= 0)
1351				standby();
1352			break;
1353
1354		case APM_USER_SUSPEND:
1355#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1356			if (apm_info.connection_version > 0x100)
1357				set_system_power_state(APM_STATE_REJECT);
1358			break;
1359#endif
1360		case APM_SYS_SUSPEND:
1361			if (ignore_bounce) {
1362				if (apm_info.connection_version > 0x100)
1363					set_system_power_state(APM_STATE_REJECT);
1364				break;
1365			}
1366			/*
1367			 * If we are already processing a SUSPEND,
1368			 * then further SUSPEND events from the BIOS
1369			 * will be ignored.  We also return here to
1370			 * cope with the fact that the Thinkpads keep
1371			 * sending a SUSPEND event until something else
1372			 * happens!
1373			 */
1374			if (ignore_sys_suspend)
1375				return;
1376			ignore_sys_suspend = 1;
1377			queue_event(event, NULL);
1378			if (suspends_pending <= 0)
1379				(void) suspend(1);
1380			break;
1381
1382		case APM_NORMAL_RESUME:
1383		case APM_CRITICAL_RESUME:
1384		case APM_STANDBY_RESUME:
1385			ignore_sys_suspend = 0;
1386			last_resume = jiffies;
1387			ignore_bounce = 1;
1388			if ((event != APM_NORMAL_RESUME)
1389			    || (ignore_normal_resume == 0)) {
1390				dpm_resume_end(PMSG_RESUME);
1391				queue_event(event, NULL);
1392			}
1393			ignore_normal_resume = 0;
1394			break;
1395
1396		case APM_CAPABILITY_CHANGE:
1397		case APM_LOW_BATTERY:
1398		case APM_POWER_STATUS_CHANGE:
1399			queue_event(event, NULL);
1400			/* If needed, notify drivers here */
1401			break;
1402
1403		case APM_UPDATE_TIME:
1404			break;
1405
1406		case APM_CRITICAL_SUSPEND:
1407			/*
1408			 * We are not allowed to reject a critical suspend.
1409			 */
1410			(void)suspend(0);
1411			break;
1412		}
1413	}
1414}
1415
1416static void apm_event_handler(void)
1417{
1418	static int pending_count = 4;
1419	int err;
1420
1421	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1422		if ((apm_info.connection_version > 0x100) &&
1423		    (pending_count-- <= 0)) {
1424			pending_count = 4;
1425			if (debug)
1426				printk(KERN_DEBUG "apm: setting state busy\n");
1427			err = set_system_power_state(APM_STATE_BUSY);
1428			if (err)
1429				apm_error("busy", err);
1430		}
1431	} else
1432		pending_count = 4;
1433	check_events();
1434}
1435
1436/*
1437 * This is the APM thread main loop.
1438 */
1439
1440static void apm_mainloop(void)
1441{
1442	DECLARE_WAITQUEUE(wait, current);
1443
1444	add_wait_queue(&apm_waitqueue, &wait);
1445	set_current_state(TASK_INTERRUPTIBLE);
1446	for (;;) {
1447		schedule_timeout(APM_CHECK_TIMEOUT);
1448		if (kthread_should_stop())
1449			break;
1450		/*
1451		 * Ok, check all events, check for idle (and mark us sleeping
1452		 * so as not to count towards the load average)..
1453		 */
1454		set_current_state(TASK_INTERRUPTIBLE);
1455		apm_event_handler();
1456	}
1457	remove_wait_queue(&apm_waitqueue, &wait);
1458}
1459
1460static int check_apm_user(struct apm_user *as, const char *func)
1461{
1462	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1463		pr_err("%s passed bad filp\n", func);
1464		return 1;
1465	}
1466	return 0;
1467}
1468
1469static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1470{
1471	struct apm_user *as;
1472	int i;
1473	apm_event_t event;
1474
1475	as = fp->private_data;
1476	if (check_apm_user(as, "read"))
1477		return -EIO;
1478	if ((int)count < sizeof(apm_event_t))
1479		return -EINVAL;
1480	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1481		return -EAGAIN;
1482	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1483	i = count;
1484	while ((i >= sizeof(event)) && !queue_empty(as)) {
1485		event = get_queued_event(as);
1486		if (copy_to_user(buf, &event, sizeof(event))) {
1487			if (i < count)
1488				break;
1489			return -EFAULT;
1490		}
1491		switch (event) {
1492		case APM_SYS_SUSPEND:
1493		case APM_USER_SUSPEND:
1494			as->suspends_read++;
1495			break;
1496
1497		case APM_SYS_STANDBY:
1498		case APM_USER_STANDBY:
1499			as->standbys_read++;
1500			break;
1501		}
1502		buf += sizeof(event);
1503		i -= sizeof(event);
1504	}
1505	if (i < count)
1506		return count - i;
1507	if (signal_pending(current))
1508		return -ERESTARTSYS;
1509	return 0;
1510}
1511
1512static __poll_t do_poll(struct file *fp, poll_table *wait)
1513{
1514	struct apm_user *as;
1515
1516	as = fp->private_data;
1517	if (check_apm_user(as, "poll"))
1518		return 0;
1519	poll_wait(fp, &apm_waitqueue, wait);
1520	if (!queue_empty(as))
1521		return EPOLLIN | EPOLLRDNORM;
1522	return 0;
1523}
1524
1525static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1526{
1527	struct apm_user *as;
1528	int ret;
1529
1530	as = filp->private_data;
1531	if (check_apm_user(as, "ioctl"))
1532		return -EIO;
1533	if (!as->suser || !as->writer)
1534		return -EPERM;
1535	switch (cmd) {
1536	case APM_IOC_STANDBY:
1537		mutex_lock(&apm_mutex);
1538		if (as->standbys_read > 0) {
1539			as->standbys_read--;
1540			as->standbys_pending--;
1541			standbys_pending--;
1542		} else
1543			queue_event(APM_USER_STANDBY, as);
1544		if (standbys_pending <= 0)
1545			standby();
1546		mutex_unlock(&apm_mutex);
1547		break;
1548	case APM_IOC_SUSPEND:
1549		mutex_lock(&apm_mutex);
1550		if (as->suspends_read > 0) {
1551			as->suspends_read--;
1552			as->suspends_pending--;
1553			suspends_pending--;
1554		} else
1555			queue_event(APM_USER_SUSPEND, as);
1556		if (suspends_pending <= 0) {
1557			ret = suspend(1);
1558			mutex_unlock(&apm_mutex);
1559		} else {
1560			as->suspend_wait = 1;
1561			mutex_unlock(&apm_mutex);
1562			wait_event_interruptible(apm_suspend_waitqueue,
1563					as->suspend_wait == 0);
1564			ret = as->suspend_result;
1565		}
1566		return ret;
1567	default:
1568		return -ENOTTY;
1569	}
1570	return 0;
1571}
1572
1573static int do_release(struct inode *inode, struct file *filp)
1574{
1575	struct apm_user *as;
1576
1577	as = filp->private_data;
1578	if (check_apm_user(as, "release"))
1579		return 0;
1580	filp->private_data = NULL;
1581	if (as->standbys_pending > 0) {
1582		standbys_pending -= as->standbys_pending;
1583		if (standbys_pending <= 0)
1584			standby();
1585	}
1586	if (as->suspends_pending > 0) {
1587		suspends_pending -= as->suspends_pending;
1588		if (suspends_pending <= 0)
1589			(void) suspend(1);
1590	}
1591	spin_lock(&user_list_lock);
1592	if (user_list == as)
1593		user_list = as->next;
1594	else {
1595		struct apm_user *as1;
1596
1597		for (as1 = user_list;
1598		     (as1 != NULL) && (as1->next != as);
1599		     as1 = as1->next)
1600			;
1601		if (as1 == NULL)
1602			pr_err("filp not in user list\n");
1603		else
1604			as1->next = as->next;
1605	}
1606	spin_unlock(&user_list_lock);
1607	kfree(as);
1608	return 0;
1609}
1610
1611static int do_open(struct inode *inode, struct file *filp)
1612{
1613	struct apm_user *as;
1614
1615	as = kmalloc(sizeof(*as), GFP_KERNEL);
1616	if (as == NULL)
1617		return -ENOMEM;
1618
1619	as->magic = APM_BIOS_MAGIC;
1620	as->event_tail = as->event_head = 0;
1621	as->suspends_pending = as->standbys_pending = 0;
1622	as->suspends_read = as->standbys_read = 0;
1623	/*
1624	 * XXX - this is a tiny bit broken, when we consider BSD
1625	 * process accounting. If the device is opened by root, we
1626	 * instantly flag that we used superuser privs. Who knows,
1627	 * we might close the device immediately without doing a
1628	 * privileged operation -- cevans
1629	 */
1630	as->suser = capable(CAP_SYS_ADMIN);
1631	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1632	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1633	spin_lock(&user_list_lock);
1634	as->next = user_list;
1635	user_list = as;
1636	spin_unlock(&user_list_lock);
1637	filp->private_data = as;
1638	return 0;
1639}
1640
1641#ifdef CONFIG_PROC_FS
1642static int proc_apm_show(struct seq_file *m, void *v)
1643{
1644	unsigned short	bx;
1645	unsigned short	cx;
1646	unsigned short	dx;
1647	int		error;
1648	unsigned short  ac_line_status = 0xff;
1649	unsigned short  battery_status = 0xff;
1650	unsigned short  battery_flag   = 0xff;
1651	int		percentage     = -1;
1652	int             time_units     = -1;
1653	char            *units         = "?";
1654
1655	if ((num_online_cpus() == 1) &&
1656	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1657		ac_line_status = (bx >> 8) & 0xff;
1658		battery_status = bx & 0xff;
1659		if ((cx & 0xff) != 0xff)
1660			percentage = cx & 0xff;
1661
1662		if (apm_info.connection_version > 0x100) {
1663			battery_flag = (cx >> 8) & 0xff;
1664			if (dx != 0xffff) {
1665				units = (dx & 0x8000) ? "min" : "sec";
1666				time_units = dx & 0x7fff;
1667			}
1668		}
1669	}
1670	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1671	   from the Get Power Status (0x0a) call unless otherwise noted.
1672
1673	   0) Linux driver version (this will change if format changes)
1674	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1675	   2) APM flags from APM Installation Check (0x00):
1676	      bit 0: APM_16_BIT_SUPPORT
1677	      bit 1: APM_32_BIT_SUPPORT
1678	      bit 2: APM_IDLE_SLOWS_CLOCK
1679	      bit 3: APM_BIOS_DISABLED
1680	      bit 4: APM_BIOS_DISENGAGED
1681	   3) AC line status
1682	      0x00: Off-line
1683	      0x01: On-line
1684	      0x02: On backup power (BIOS >= 1.1 only)
1685	      0xff: Unknown
1686	   4) Battery status
1687	      0x00: High
1688	      0x01: Low
1689	      0x02: Critical
1690	      0x03: Charging
1691	      0x04: Selected battery not present (BIOS >= 1.2 only)
1692	      0xff: Unknown
1693	   5) Battery flag
1694	      bit 0: High
1695	      bit 1: Low
1696	      bit 2: Critical
1697	      bit 3: Charging
1698	      bit 7: No system battery
1699	      0xff: Unknown
1700	   6) Remaining battery life (percentage of charge):
1701	      0-100: valid
1702	      -1: Unknown
1703	   7) Remaining battery life (time units):
1704	      Number of remaining minutes or seconds
1705	      -1: Unknown
1706	   8) min = minutes; sec = seconds */
1707
1708	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1709		   driver_version,
1710		   (apm_info.bios.version >> 8) & 0xff,
1711		   apm_info.bios.version & 0xff,
1712		   apm_info.bios.flags,
1713		   ac_line_status,
1714		   battery_status,
1715		   battery_flag,
1716		   percentage,
1717		   time_units,
1718		   units);
1719	return 0;
1720}
1721#endif
1722
1723static int apm(void *unused)
1724{
1725	unsigned short	bx;
1726	unsigned short	cx;
1727	unsigned short	dx;
1728	int		error;
1729	char 		*power_stat;
1730	char 		*bat_stat;
1731
1732	/* 2002/08/01 - WT
1733	 * This is to avoid random crashes at boot time during initialization
1734	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1735	 * Some bioses don't like being called from CPU != 0.
1736	 * Method suggested by Ingo Molnar.
1737	 */
1738	set_cpus_allowed_ptr(current, cpumask_of(0));
1739	BUG_ON(smp_processor_id() != 0);
1740
1741	if (apm_info.connection_version == 0) {
1742		apm_info.connection_version = apm_info.bios.version;
1743		if (apm_info.connection_version > 0x100) {
1744			/*
1745			 * We only support BIOSs up to version 1.2
1746			 */
1747			if (apm_info.connection_version > 0x0102)
1748				apm_info.connection_version = 0x0102;
1749			error = apm_driver_version(&apm_info.connection_version);
1750			if (error != APM_SUCCESS) {
1751				apm_error("driver version", error);
1752				/* Fall back to an APM 1.0 connection. */
1753				apm_info.connection_version = 0x100;
1754			}
1755		}
1756	}
1757
1758	if (debug)
1759		printk(KERN_INFO "apm: Connection version %d.%d\n",
1760			(apm_info.connection_version >> 8) & 0xff,
1761			apm_info.connection_version & 0xff);
1762
1763#ifdef CONFIG_APM_DO_ENABLE
1764	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1765		/*
1766		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1767		 * is booted with PM disabled but not in the docking station.
1768		 * Unfortunate ...
1769		 */
1770		error = apm_enable_power_management(1);
1771		if (error) {
1772			apm_error("enable power management", error);
1773			return -1;
1774		}
1775	}
1776#endif
1777
1778	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1779	    && (apm_info.connection_version > 0x0100)) {
1780		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1781		if (error) {
1782			apm_error("engage power management", error);
1783			return -1;
1784		}
1785	}
1786
1787	if (debug && (num_online_cpus() == 1 || smp)) {
1788		error = apm_get_power_status(&bx, &cx, &dx);
1789		if (error)
1790			printk(KERN_INFO "apm: power status not available\n");
1791		else {
1792			switch ((bx >> 8) & 0xff) {
1793			case 0:
1794				power_stat = "off line";
1795				break;
1796			case 1:
1797				power_stat = "on line";
1798				break;
1799			case 2:
1800				power_stat = "on backup power";
1801				break;
1802			default:
1803				power_stat = "unknown";
1804				break;
1805			}
1806			switch (bx & 0xff) {
1807			case 0:
1808				bat_stat = "high";
1809				break;
1810			case 1:
1811				bat_stat = "low";
1812				break;
1813			case 2:
1814				bat_stat = "critical";
1815				break;
1816			case 3:
1817				bat_stat = "charging";
1818				break;
1819			default:
1820				bat_stat = "unknown";
1821				break;
1822			}
1823			printk(KERN_INFO
1824			       "apm: AC %s, battery status %s, battery life ",
1825			       power_stat, bat_stat);
1826			if ((cx & 0xff) == 0xff)
1827				printk("unknown\n");
1828			else
1829				printk("%d%%\n", cx & 0xff);
1830			if (apm_info.connection_version > 0x100) {
1831				printk(KERN_INFO
1832				       "apm: battery flag 0x%02x, battery life ",
1833				       (cx >> 8) & 0xff);
1834				if (dx == 0xffff)
1835					printk("unknown\n");
1836				else
1837					printk("%d %s\n", dx & 0x7fff,
1838					       (dx & 0x8000) ?
1839					       "minutes" : "seconds");
1840			}
1841		}
1842	}
1843
1844	/* Install our power off handler.. */
1845	if (power_off)
1846		pm_power_off = apm_power_off;
1847
1848	if (num_online_cpus() == 1 || smp) {
1849#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1850		console_blank_hook = apm_console_blank;
1851#endif
1852		apm_mainloop();
1853#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1854		console_blank_hook = NULL;
1855#endif
1856	}
1857
1858	return 0;
1859}
1860
1861#ifndef MODULE
1862static int __init apm_setup(char *str)
1863{
1864	int invert;
1865
1866	while ((str != NULL) && (*str != '\0')) {
1867		if (strncmp(str, "off", 3) == 0)
1868			apm_disabled = 1;
1869		if (strncmp(str, "on", 2) == 0)
1870			apm_disabled = 0;
1871		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1872		    (strncmp(str, "bounce_interval=", 16) == 0))
1873			bounce_interval = simple_strtol(str + 16, NULL, 0);
1874		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1875		    (strncmp(str, "idle_threshold=", 15) == 0))
1876			idle_threshold = simple_strtol(str + 15, NULL, 0);
1877		if ((strncmp(str, "idle-period=", 12) == 0) ||
1878		    (strncmp(str, "idle_period=", 12) == 0))
1879			idle_period = simple_strtol(str + 12, NULL, 0);
1880		invert = (strncmp(str, "no-", 3) == 0) ||
1881			(strncmp(str, "no_", 3) == 0);
1882		if (invert)
1883			str += 3;
1884		if (strncmp(str, "debug", 5) == 0)
1885			debug = !invert;
1886		if ((strncmp(str, "power-off", 9) == 0) ||
1887		    (strncmp(str, "power_off", 9) == 0))
1888			power_off = !invert;
1889		if (strncmp(str, "smp", 3) == 0) {
1890			smp = !invert;
1891			idle_threshold = 100;
1892		}
1893		if ((strncmp(str, "allow-ints", 10) == 0) ||
1894		    (strncmp(str, "allow_ints", 10) == 0))
1895			apm_info.allow_ints = !invert;
1896		if ((strncmp(str, "broken-psr", 10) == 0) ||
1897		    (strncmp(str, "broken_psr", 10) == 0))
1898			apm_info.get_power_status_broken = !invert;
1899		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1900		    (strncmp(str, "realmode_power_off", 18) == 0))
1901			apm_info.realmode_power_off = !invert;
1902		str = strchr(str, ',');
1903		if (str != NULL)
1904			str += strspn(str, ", \t");
1905	}
1906	return 1;
1907}
1908
1909__setup("apm=", apm_setup);
1910#endif
1911
1912static const struct file_operations apm_bios_fops = {
1913	.owner		= THIS_MODULE,
1914	.read		= do_read,
1915	.poll		= do_poll,
1916	.unlocked_ioctl	= do_ioctl,
1917	.open		= do_open,
1918	.release	= do_release,
1919	.llseek		= noop_llseek,
1920};
1921
1922static struct miscdevice apm_device = {
1923	APM_MINOR_DEV,
1924	"apm_bios",
1925	&apm_bios_fops
1926};
1927
1928
1929/* Simple "print if true" callback */
1930static int __init print_if_true(const struct dmi_system_id *d)
1931{
1932	printk("%s\n", d->ident);
1933	return 0;
1934}
1935
1936/*
1937 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1938 * disabled before the suspend. Linux used to get terribly confused by that.
1939 */
1940static int __init broken_ps2_resume(const struct dmi_system_id *d)
1941{
1942	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1943	       "workaround hopefully not needed.\n", d->ident);
1944	return 0;
1945}
1946
1947/* Some bioses have a broken protected mode poweroff and need to use realmode */
1948static int __init set_realmode_power_off(const struct dmi_system_id *d)
1949{
1950	if (apm_info.realmode_power_off == 0) {
1951		apm_info.realmode_power_off = 1;
1952		printk(KERN_INFO "%s bios detected. "
1953		       "Using realmode poweroff only.\n", d->ident);
1954	}
1955	return 0;
1956}
1957
1958/* Some laptops require interrupts to be enabled during APM calls */
1959static int __init set_apm_ints(const struct dmi_system_id *d)
1960{
1961	if (apm_info.allow_ints == 0) {
1962		apm_info.allow_ints = 1;
1963		printk(KERN_INFO "%s machine detected. "
1964		       "Enabling interrupts during APM calls.\n", d->ident);
1965	}
1966	return 0;
1967}
1968
1969/* Some APM bioses corrupt memory or just plain do not work */
1970static int __init apm_is_horked(const struct dmi_system_id *d)
1971{
1972	if (apm_info.disabled == 0) {
1973		apm_info.disabled = 1;
1974		printk(KERN_INFO "%s machine detected. "
1975		       "Disabling APM.\n", d->ident);
1976	}
1977	return 0;
1978}
1979
1980static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1981{
1982	if (apm_info.disabled == 0) {
1983		apm_info.disabled = 1;
1984		printk(KERN_INFO "%s machine detected. "
1985		       "Disabling APM.\n", d->ident);
1986		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1987		printk(KERN_INFO "download from support.intel.com\n");
1988	}
1989	return 0;
1990}
1991
1992/* Some APM bioses hang on APM idle calls */
1993static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1994{
1995	if (apm_info.forbid_idle == 0) {
1996		apm_info.forbid_idle = 1;
1997		printk(KERN_INFO "%s machine detected. "
1998		       "Disabling APM idle calls.\n", d->ident);
1999	}
2000	return 0;
2001}
2002
2003/*
2004 *  Check for clue free BIOS implementations who use
2005 *  the following QA technique
2006 *
2007 *      [ Write BIOS Code ]<------
2008 *               |                ^
2009 *      < Does it Compile >----N--
2010 *               |Y               ^
2011 *	< Does it Boot Win98 >-N--
2012 *               |Y
2013 *           [Ship It]
2014 *
2015 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2016 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2017 */
2018static int __init broken_apm_power(const struct dmi_system_id *d)
2019{
2020	apm_info.get_power_status_broken = 1;
2021	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2022	       "disabling power status reporting.\n");
2023	return 0;
2024}
2025
2026/*
2027 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2028 * have this problem).
2029 */
2030static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2031{
2032	apm_info.get_power_status_swabinminutes = 1;
2033	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2034	       "in minutes and wrong byte order.\n");
2035	return 0;
2036}
2037
2038static const struct dmi_system_id apm_dmi_table[] __initconst = {
2039	{
2040		print_if_true,
2041		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2042		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2043			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2044	},
2045	{	/* Handle problems with APM on the C600 */
2046		broken_ps2_resume, "Dell Latitude C600",
2047		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2048			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2049	},
2050	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2051		set_apm_ints, "Dell Latitude",
2052		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2053			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2054	},
2055	{	/* APM crashes */
2056		apm_is_horked, "Dell Inspiron 2500",
2057		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2058			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2059			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2060			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2061	},
2062	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2063		set_apm_ints, "Dell Inspiron", {
2064			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2065			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2066	},
2067	{	/* Handle problems with APM on Inspiron 5000e */
2068		broken_apm_power, "Dell Inspiron 5000e",
2069		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2070			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2071			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2072	},
2073	{	/* Handle problems with APM on Inspiron 2500 */
2074		broken_apm_power, "Dell Inspiron 2500",
2075		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2076			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2077			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2078	},
2079	{	/* APM crashes */
2080		apm_is_horked, "Dell Dimension 4100",
2081		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2082			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2083			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2084			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2085	},
2086	{	/* Allow interrupts during suspend on Compaq Laptops*/
2087		set_apm_ints, "Compaq 12XL125",
2088		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2089			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2090			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2091			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2092	},
2093	{	/* Allow interrupts during APM or the clock goes slow */
2094		set_apm_ints, "ASUSTeK",
2095		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2096			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2097	},
2098	{	/* APM blows on shutdown */
2099		apm_is_horked, "ABIT KX7-333[R]",
2100		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2101			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2102	},
2103	{	/* APM crashes */
2104		apm_is_horked, "Trigem Delhi3",
2105		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2106			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2107	},
2108	{	/* APM crashes */
2109		apm_is_horked, "Fujitsu-Siemens",
2110		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2111			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2112	},
2113	{	/* APM crashes */
2114		apm_is_horked_d850md, "Intel D850MD",
2115		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2116			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2117	},
2118	{	/* APM crashes */
2119		apm_is_horked, "Intel D810EMO",
2120		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2121			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2122	},
2123	{	/* APM crashes */
2124		apm_is_horked, "Dell XPS-Z",
2125		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2126			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2127			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2128	},
2129	{	/* APM crashes */
2130		apm_is_horked, "Sharp PC-PJ/AX",
2131		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2132			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2133			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2134			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2135	},
2136	{	/* APM crashes */
2137		apm_is_horked, "Dell Inspiron 2500",
2138		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2139			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2140			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2141			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2142	},
2143	{	/* APM idle hangs */
2144		apm_likes_to_melt, "Jabil AMD",
2145		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2146			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2147	},
2148	{	/* APM idle hangs */
2149		apm_likes_to_melt, "AMI Bios",
2150		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2151			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2152	},
2153	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2154		swab_apm_power_in_minutes, "Sony VAIO",
2155		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2156			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2157			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2158	},
2159	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2160		swab_apm_power_in_minutes, "Sony VAIO",
2161		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2162			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2163			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2164	},
2165	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2166		swab_apm_power_in_minutes, "Sony VAIO",
2167		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2168			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2169			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2170	},
2171	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2172		swab_apm_power_in_minutes, "Sony VAIO",
2173		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2174			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2175			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2176	},
2177	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2178		swab_apm_power_in_minutes, "Sony VAIO",
2179		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2180			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2181			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2182	},
2183	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2184		swab_apm_power_in_minutes, "Sony VAIO",
2185		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2186			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2187			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2188	},
2189	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2190		swab_apm_power_in_minutes, "Sony VAIO",
2191		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2192			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2193			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2194	},
2195	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2196		swab_apm_power_in_minutes, "Sony VAIO",
2197		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2198			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2199			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2200	},
2201	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2202		swab_apm_power_in_minutes, "Sony VAIO",
2203		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2204			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2205			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2206	},
2207	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2208		swab_apm_power_in_minutes, "Sony VAIO",
2209		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2211			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2212	},
2213
2214	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2215		swab_apm_power_in_minutes, "Sony VAIO",
2216		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2217			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2218			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2219	},
2220	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2221		swab_apm_power_in_minutes, "Sony VAIO",
2222		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2223			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2224			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2225	},
2226	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2227		swab_apm_power_in_minutes, "Sony VAIO",
2228		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2229			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2230			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2231	},
2232	{	/* broken PM poweroff bios */
2233		set_realmode_power_off, "Award Software v4.60 PGMA",
2234		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2235			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2236			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2237	},
2238
2239	/* Generic per vendor APM settings  */
2240
2241	{	/* Allow interrupts during suspend on IBM laptops */
2242		set_apm_ints, "IBM",
2243		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2244	},
2245
2246	{ }
2247};
2248
2249/*
2250 * Just start the APM thread. We do NOT want to do APM BIOS
2251 * calls from anything but the APM thread, if for no other reason
2252 * than the fact that we don't trust the APM BIOS. This way,
2253 * most common APM BIOS problems that lead to protection errors
2254 * etc will have at least some level of being contained...
2255 *
2256 * In short, if something bad happens, at least we have a choice
2257 * of just killing the apm thread..
2258 */
2259static int __init apm_init(void)
2260{
2261	struct desc_struct *gdt;
2262	int err;
2263
2264	dmi_check_system(apm_dmi_table);
2265
2266	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2267		printk(KERN_INFO "apm: BIOS not found.\n");
2268		return -ENODEV;
2269	}
2270	printk(KERN_INFO
2271	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2272	       ((apm_info.bios.version >> 8) & 0xff),
2273	       (apm_info.bios.version & 0xff),
2274	       apm_info.bios.flags,
2275	       driver_version);
2276	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2277		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2278		return -ENODEV;
2279	}
2280
2281	if (allow_ints)
2282		apm_info.allow_ints = 1;
2283	if (broken_psr)
2284		apm_info.get_power_status_broken = 1;
2285	if (realmode_power_off)
2286		apm_info.realmode_power_off = 1;
2287	/* User can override, but default is to trust DMI */
2288	if (apm_disabled != -1)
2289		apm_info.disabled = apm_disabled;
2290
2291	/*
2292	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2293	 * but is reportedly a 1.0 BIOS.
2294	 */
2295	if (apm_info.bios.version == 0x001)
2296		apm_info.bios.version = 0x100;
2297
2298	/* BIOS < 1.2 doesn't set cseg_16_len */
2299	if (apm_info.bios.version < 0x102)
2300		apm_info.bios.cseg_16_len = 0; /* 64k */
2301
2302	if (debug) {
2303		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2304			apm_info.bios.cseg, apm_info.bios.offset,
2305			apm_info.bios.cseg_16, apm_info.bios.dseg);
2306		if (apm_info.bios.version > 0x100)
2307			printk(" cseg len %x, dseg len %x",
2308				apm_info.bios.cseg_len,
2309				apm_info.bios.dseg_len);
2310		if (apm_info.bios.version > 0x101)
2311			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2312		printk("\n");
2313	}
2314
2315	if (apm_info.disabled) {
2316		pr_notice("disabled on user request.\n");
2317		return -ENODEV;
2318	}
2319	if ((num_online_cpus() > 1) && !power_off && !smp) {
2320		pr_notice("disabled - APM is not SMP safe.\n");
2321		apm_info.disabled = 1;
2322		return -ENODEV;
2323	}
2324	if (!acpi_disabled) {
2325		pr_notice("overridden by ACPI.\n");
2326		apm_info.disabled = 1;
2327		return -ENODEV;
2328	}
2329
2330	/*
2331	 * Set up the long jump entry point to the APM BIOS, which is called
2332	 * from inline assembly.
2333	 */
2334	apm_bios_entry.offset = apm_info.bios.offset;
2335	apm_bios_entry.segment = APM_CS;
2336
2337	/*
2338	 * The APM 1.1 BIOS is supposed to provide limit information that it
2339	 * recognizes.  Many machines do this correctly, but many others do
2340	 * not restrict themselves to their claimed limit.  When this happens,
2341	 * they will cause a segmentation violation in the kernel at boot time.
2342	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2343	 *
2344	 * Note we only set APM segments on CPU zero, since we pin the APM
2345	 * code to that CPU.
2346	 */
2347	gdt = get_cpu_gdt_rw(0);
2348	set_desc_base(&gdt[APM_CS >> 3],
2349		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2350	set_desc_base(&gdt[APM_CS_16 >> 3],
2351		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2352	set_desc_base(&gdt[APM_DS >> 3],
2353		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2354
2355	proc_create_single("apm", 0, NULL, proc_apm_show);
2356
2357	kapmd_task = kthread_create(apm, NULL, "kapmd");
2358	if (IS_ERR(kapmd_task)) {
2359		pr_err("disabled - Unable to start kernel thread\n");
2360		err = PTR_ERR(kapmd_task);
2361		kapmd_task = NULL;
2362		remove_proc_entry("apm", NULL);
2363		return err;
2364	}
2365	wake_up_process(kapmd_task);
2366
2367	if (num_online_cpus() > 1 && !smp) {
2368		printk(KERN_NOTICE
2369		       "apm: disabled - APM is not SMP safe (power off active).\n");
2370		return 0;
2371	}
2372
2373	/*
2374	 * Note we don't actually care if the misc_device cannot be registered.
2375	 * this driver can do its job without it, even if userspace can't
2376	 * control it.  just log the error
2377	 */
2378	if (misc_register(&apm_device))
2379		printk(KERN_WARNING "apm: Could not register misc device.\n");
2380
2381	if (HZ != 100)
2382		idle_period = (idle_period * HZ) / 100;
2383	if (idle_threshold < 100) {
2384		cpuidle_poll_state_init(&apm_idle_driver);
2385		if (!cpuidle_register_driver(&apm_idle_driver))
2386			if (cpuidle_register_device(&apm_cpuidle_device))
2387				cpuidle_unregister_driver(&apm_idle_driver);
2388	}
2389
2390	return 0;
2391}
2392
2393static void __exit apm_exit(void)
2394{
2395	int error;
2396
2397	cpuidle_unregister_device(&apm_cpuidle_device);
2398	cpuidle_unregister_driver(&apm_idle_driver);
2399
2400	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2401	    && (apm_info.connection_version > 0x0100)) {
2402		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2403		if (error)
2404			apm_error("disengage power management", error);
2405	}
2406	misc_deregister(&apm_device);
2407	remove_proc_entry("apm", NULL);
2408	if (power_off)
2409		pm_power_off = NULL;
2410	if (kapmd_task) {
2411		kthread_stop(kapmd_task);
2412		kapmd_task = NULL;
2413	}
2414}
2415
2416module_init(apm_init);
2417module_exit(apm_exit);
2418
2419MODULE_AUTHOR("Stephen Rothwell");
2420MODULE_DESCRIPTION("Advanced Power Management");
2421MODULE_LICENSE("GPL");
2422module_param(debug, bool, 0644);
2423MODULE_PARM_DESC(debug, "Enable debug mode");
2424module_param(power_off, bool, 0444);
2425MODULE_PARM_DESC(power_off, "Enable power off");
2426module_param(bounce_interval, int, 0444);
2427MODULE_PARM_DESC(bounce_interval,
2428		"Set the number of ticks to ignore suspend bounces");
2429module_param(allow_ints, bool, 0444);
2430MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2431module_param(broken_psr, bool, 0444);
2432MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2433module_param(realmode_power_off, bool, 0444);
2434MODULE_PARM_DESC(realmode_power_off,
2435		"Switch to real mode before powering off");
2436module_param(idle_threshold, int, 0444);
2437MODULE_PARM_DESC(idle_threshold,
2438	"System idle percentage above which to make APM BIOS idle calls");
2439module_param(idle_period, int, 0444);
2440MODULE_PARM_DESC(idle_period,
2441	"Period (in sec/100) over which to calculate the idle percentage");
2442module_param(smp, bool, 0444);
2443MODULE_PARM_DESC(smp,
2444	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2445MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);