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v3.5.6
 
   1/* -*- linux-c -*-
   2 * APM BIOS driver for Linux
   3 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   4 *
   5 * Initial development of this driver was funded by NEC Australia P/L
   6 *	and NEC Corporation
   7 *
   8 * This program is free software; you can redistribute it and/or modify it
   9 * under the terms of the GNU General Public License as published by the
  10 * Free Software Foundation; either version 2, or (at your option) any
  11 * later version.
  12 *
  13 * This program is distributed in the hope that it will be useful, but
  14 * WITHOUT ANY WARRANTY; without even the implied warranty of
  15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 * General Public License for more details.
  17 *
  18 * October 1995, Rik Faith (faith@cs.unc.edu):
  19 *    Minor enhancements and updates (to the patch set) for 1.3.x
  20 *    Documentation
  21 * January 1996, Rik Faith (faith@cs.unc.edu):
  22 *    Make /proc/apm easy to format (bump driver version)
  23 * March 1996, Rik Faith (faith@cs.unc.edu):
  24 *    Prohibit APM BIOS calls unless apm_enabled.
  25 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  26 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  27 *    Version 1.0 and 1.1
  28 * May 1996, Version 1.2
  29 * Feb 1998, Version 1.3
  30 * Feb 1998, Version 1.4
  31 * Aug 1998, Version 1.5
  32 * Sep 1998, Version 1.6
  33 * Nov 1998, Version 1.7
  34 * Jan 1999, Version 1.8
  35 * Jan 1999, Version 1.9
  36 * Oct 1999, Version 1.10
  37 * Nov 1999, Version 1.11
  38 * Jan 2000, Version 1.12
  39 * Feb 2000, Version 1.13
  40 * Nov 2000, Version 1.14
  41 * Oct 2001, Version 1.15
  42 * Jan 2002, Version 1.16
  43 * Oct 2002, Version 1.16ac
  44 *
  45 * History:
  46 *    0.6b: first version in official kernel, Linux 1.3.46
  47 *    0.7: changed /proc/apm format, Linux 1.3.58
  48 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  49 *    0.9: only call bios if bios is present, Linux 1.3.72
  50 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  51 *         Linux 1.3.85
  52 *    1.1: support user-space standby and suspend, power off after system
  53 *         halted, Linux 1.3.98
  54 *    1.2: When resetting RTC after resume, take care so that the time
  55 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  56 *         <jtoth@princeton.edu>); improve interaction between
  57 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  58 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  59 *	   levels to the printk calls. APM is not defined for SMP machines.
  60 *         The new replacement for it is, but Linux doesn't yet support this.
  61 *         Alan Cox Linux 2.1.55
  62 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  63 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  64 *         Dean Gaudet <dgaudet@arctic.org>.
  65 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  66 *    1.5: Fix segment register reloading (in case of bad segments saved
  67 *         across BIOS call).
  68 *         Stephen Rothwell
  69 *    1.6: Cope with compiler/assembler differences.
  70 *         Only try to turn off the first display device.
  71 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  72 *                   <echter@informatik.uni-rostock.de>
  73 *         Stephen Rothwell
  74 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  75 *         to reflect current state of APM BIOS.
  76 *         Chris Rankin <rankinc@bellsouth.net>
  77 *         Reset interrupt 0 timer to 100Hz after suspend
  78 *         Chad Miller <cmiller@surfsouth.com>
  79 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  80 *         Richard Gooch <rgooch@atnf.csiro.au>
  81 *         Allow boot time disabling of APM
  82 *         Make boot messages far less verbose by default
  83 *         Make asm safer
  84 *         Stephen Rothwell
  85 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  86 *         Richard Gooch <rgooch@atnf.csiro.au>
  87 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  88 *         remove dependency on CONFIG_PROC_FS
  89 *         Stephen Rothwell
  90 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  91 *         Try to cope with BIOS's that need to have all display
  92 *         devices blanked and not just the first one.
  93 *         Ross Paterson <ross@soi.city.ac.uk>
  94 *         Fix segment limit setting it has always been wrong as
  95 *         the segments needed to have byte granularity.
  96 *         Mark a few things __init.
  97 *         Add hack to allow power off of SMP systems by popular request.
  98 *         Use CONFIG_SMP instead of __SMP__
  99 *         Ignore BOUNCES for three seconds.
 100 *         Stephen Rothwell
 101 *   1.10: Fix for Thinkpad return code.
 102 *         Merge 2.2 and 2.3 drivers.
 103 *         Remove APM dependencies in arch/i386/kernel/process.c
 104 *         Remove APM dependencies in drivers/char/sysrq.c
 105 *         Reset time across standby.
 106 *         Allow more inititialisation on SMP.
 107 *         Remove CONFIG_APM_POWER_OFF and make it boot time
 108 *         configurable (default on).
 109 *         Make debug only a boot time parameter (remove APM_DEBUG).
 110 *         Try to blank all devices on any error.
 111 *   1.11: Remove APM dependencies in drivers/char/console.c
 112 *         Check nr_running to detect if we are idle (from
 113 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 114 *         Fix for bioses that don't zero the top part of the
 115 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 116 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 117 *         Real mode power off patch (Walter Hofmann
 118 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 119 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 120 *         the code away anyway (smp_num_cpus == 1 in UP)
 121 *         noted by Artur Skawina <skawina@geocities.com>.
 122 *         Make power off under SMP work again.
 123 *         Fix thinko with initial engaging of BIOS.
 124 *         Make sure power off only happens on CPU 0
 125 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 126 *         Do error notification to user mode if BIOS calls fail.
 127 *         Move entrypoint offset fix to ...boot/setup.S
 128 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 129 *         Remove smp-power-off. SMP users must now specify
 130 *         "apm=power-off" on the kernel command line. Suggested
 131 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 132 *         <alan@lxorguk.ukuu.org.uk>.
 133 *         Register the /proc/apm entry even on SMP so that
 134 *         scripts that check for it before doing power off
 135 *         work (Jim Avera <jima@hal.com>).
 136 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 137 *         <andy_henroid@yahoo.com>).
 138 *         Modularize the code.
 139 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 140 *         is now the way life works).
 141 *         Fix thinko in suspend() (wrong return).
 142 *         Notify drivers on critical suspend.
 143 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 144 *         modified by sfr).
 145 *         Disable interrupts while we are suspended (Andy Henroid
 146 *         <andy_henroid@yahoo.com> fixed by sfr).
 147 *         Make power off work on SMP again (Tony Hoyle
 148 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 149 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 150 *         interval is now configurable.
 151 *   1.14: Make connection version persist across module unload/load.
 152 *         Enable and engage power management earlier.
 153 *         Disengage power management on module unload.
 154 *         Changed to use the sysrq-register hack for registering the
 155 *         power off function called by magic sysrq based upon discussions
 156 *         in irc://irc.openprojects.net/#kernelnewbies
 157 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 158 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 159 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 160 *         Work around byte swap bug in one of the Vaio's BIOS's
 161 *         (Marc Boucher <marc@mbsi.ca>).
 162 *         Exposed the disable flag to dmi so that we can handle known
 163 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 164 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 165 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 166 *         If an APM idle fails log it and idle sensibly
 167 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 168 *         Don't expect replies from clients who open the device O_RDONLY.
 169 *         (Idea from Thomas Hood)
 170 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 171 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 172 *         Notify listeners of standby or suspend events before notifying
 173 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 174 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 175 *         Ignore first resume after we generate our own resume event
 176 *         after a suspend (Thomas Hood)
 177 *         Daemonize now gets rid of our controlling terminal (sfr).
 178 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 179 *         idle_threshold (sfr).
 180 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 181 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 182 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 183 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 184 *
 185 * APM 1.1 Reference:
 186 *
 187 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 188 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 189 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 190 *
 191 * [This document is available free from Intel by calling 800.628.8686 (fax
 192 * 916.356.6100) or 800.548.4725; or from
 193 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 194 * available from Microsoft by calling 206.882.8080.]
 195 *
 196 * APM 1.2 Reference:
 197 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 198 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 199 *
 200 * [This document is available from Microsoft at:
 201 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 202 */
 203
 
 
 204#include <linux/module.h>
 205
 206#include <linux/poll.h>
 207#include <linux/types.h>
 208#include <linux/stddef.h>
 209#include <linux/timer.h>
 210#include <linux/fcntl.h>
 211#include <linux/slab.h>
 212#include <linux/stat.h>
 213#include <linux/proc_fs.h>
 214#include <linux/seq_file.h>
 215#include <linux/miscdevice.h>
 216#include <linux/apm_bios.h>
 217#include <linux/init.h>
 218#include <linux/time.h>
 219#include <linux/sched.h>
 
 220#include <linux/pm.h>
 221#include <linux/capability.h>
 222#include <linux/device.h>
 223#include <linux/kernel.h>
 224#include <linux/freezer.h>
 225#include <linux/smp.h>
 226#include <linux/dmi.h>
 227#include <linux/suspend.h>
 228#include <linux/kthread.h>
 229#include <linux/jiffies.h>
 230#include <linux/acpi.h>
 231#include <linux/syscore_ops.h>
 232#include <linux/i8253.h>
 
 233
 234#include <asm/uaccess.h>
 235#include <asm/desc.h>
 236#include <asm/olpc.h>
 237#include <asm/paravirt.h>
 238#include <asm/reboot.h>
 
 
 239
 240#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 241extern int (*console_blank_hook)(int);
 242#endif
 243
 244/*
 245 * The apm_bios device is one of the misc char devices.
 246 * This is its minor number.
 247 */
 248#define	APM_MINOR_DEV	134
 249
 250/*
 251 * Various options can be changed at boot time as follows:
 252 * (We allow underscores for compatibility with the modules code)
 253 *	apm=on/off			enable/disable APM
 254 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 255 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 256 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 257 *	    					powering off
 258 *	    [no-]debug			log some debugging messages
 259 *	    [no-]power[-_]off		power off on shutdown
 260 *	    [no-]smp			Use apm even on an SMP box
 261 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 262 *	    				bounces
 263 *          idle[-_]threshold=<n>       System idle percentage above which to
 264 *                                      make APM BIOS idle calls. Set it to
 265 *                                      100 to disable.
 266 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 267 *                                      which the idle percentage is
 268 *                                      calculated.
 269 */
 270
 271/* KNOWN PROBLEM MACHINES:
 272 *
 273 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 274 *                         [Confirmed by TI representative]
 275 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 276 *                    [Confirmed by BIOS disassembly]
 277 *                    [This may work now ...]
 278 * P: Toshiba 1950S: battery life information only gets updated after resume
 279 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 280 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 281 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 282 * 	Neale Banks <neale@lowendale.com.au> December 2000
 283 *
 284 * Legend: U = unusable with APM patches
 285 *         P = partially usable with APM patches
 286 */
 287
 288/*
 289 * Define as 1 to make the driver always call the APM BIOS busy
 290 * routine even if the clock was not reported as slowed by the
 291 * idle routine.  Otherwise, define as 0.
 292 */
 293#define ALWAYS_CALL_BUSY   1
 294
 295/*
 296 * Define to make the APM BIOS calls zero all data segment registers (so
 297 * that an incorrect BIOS implementation will cause a kernel panic if it
 298 * tries to write to arbitrary memory).
 299 */
 300#define APM_ZERO_SEGS
 301
 302#include <asm/apm.h>
 303
 304/*
 305 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 306 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 307 * David Chen <chen@ctpa04.mit.edu>
 308 */
 309#undef INIT_TIMER_AFTER_SUSPEND
 310
 311#ifdef INIT_TIMER_AFTER_SUSPEND
 312#include <linux/timex.h>
 313#include <asm/io.h>
 314#include <linux/delay.h>
 315#endif
 316
 317/*
 318 * Need to poll the APM BIOS every second
 319 */
 320#define APM_CHECK_TIMEOUT	(HZ)
 321
 322/*
 323 * Ignore suspend events for this amount of time after a resume
 324 */
 325#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 326
 327/*
 328 * Maximum number of events stored
 329 */
 330#define APM_MAX_EVENTS		20
 331
 332/*
 333 * The per-file APM data
 334 */
 335struct apm_user {
 336	int		magic;
 337	struct apm_user *next;
 338	unsigned int	suser: 1;
 339	unsigned int	writer: 1;
 340	unsigned int	reader: 1;
 341	unsigned int	suspend_wait: 1;
 342	int		suspend_result;
 343	int		suspends_pending;
 344	int		standbys_pending;
 345	int		suspends_read;
 346	int		standbys_read;
 347	int		event_head;
 348	int		event_tail;
 349	apm_event_t	events[APM_MAX_EVENTS];
 350};
 351
 352/*
 353 * The magic number in apm_user
 354 */
 355#define APM_BIOS_MAGIC		0x4101
 356
 357/*
 358 * idle percentage above which bios idle calls are done
 359 */
 360#ifdef CONFIG_APM_CPU_IDLE
 361#warning deprecated CONFIG_APM_CPU_IDLE will be deleted in 2012
 362#define DEFAULT_IDLE_THRESHOLD	95
 363#else
 364#define DEFAULT_IDLE_THRESHOLD	100
 365#endif
 366#define DEFAULT_IDLE_PERIOD	(100 / 3)
 367
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 368/*
 369 * Local variables
 370 */
 371static struct {
 372	unsigned long	offset;
 373	unsigned short	segment;
 374} apm_bios_entry;
 375static int clock_slowed;
 376static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 377static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 378static int set_pm_idle;
 379static int suspends_pending;
 380static int standbys_pending;
 381static int ignore_sys_suspend;
 382static int ignore_normal_resume;
 383static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 384
 385static bool debug __read_mostly;
 386static bool smp __read_mostly;
 387static int apm_disabled = -1;
 388#ifdef CONFIG_SMP
 389static bool power_off;
 390#else
 391static bool power_off = 1;
 392#endif
 393static bool realmode_power_off;
 394#ifdef CONFIG_APM_ALLOW_INTS
 395static bool allow_ints = 1;
 396#else
 397static bool allow_ints;
 398#endif
 399static bool broken_psr;
 400
 401static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 402static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 403static struct apm_user *user_list;
 404static DEFINE_SPINLOCK(user_list_lock);
 405static DEFINE_MUTEX(apm_mutex);
 406
 407/*
 408 * Set up a segment that references the real mode segment 0x40
 409 * that extends up to the end of page zero (that we have reserved).
 410 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 411 * even though they are called in protected mode.
 412 */
 413static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
 414			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 415
 416static const char driver_version[] = "1.16ac";	/* no spaces */
 417
 418static struct task_struct *kapmd_task;
 419
 420/*
 421 *	APM event names taken from the APM 1.2 specification. These are
 422 *	the message codes that the BIOS uses to tell us about events
 423 */
 424static const char * const apm_event_name[] = {
 425	"system standby",
 426	"system suspend",
 427	"normal resume",
 428	"critical resume",
 429	"low battery",
 430	"power status change",
 431	"update time",
 432	"critical suspend",
 433	"user standby",
 434	"user suspend",
 435	"system standby resume",
 436	"capabilities change"
 437};
 438#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 439
 440typedef struct lookup_t {
 441	int	key;
 442	char 	*msg;
 443} lookup_t;
 444
 445/*
 446 *	The BIOS returns a set of standard error codes in AX when the
 447 *	carry flag is set.
 448 */
 449
 450static const lookup_t error_table[] = {
 451/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 452	{ APM_DISABLED,		"Power management disabled" },
 453	{ APM_CONNECTED,	"Real mode interface already connected" },
 454	{ APM_NOT_CONNECTED,	"Interface not connected" },
 455	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 456/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 457	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 458	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 459	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 460	{ APM_BAD_PARAM,	"Parameter out of range" },
 461	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 462	{ APM_BAD_FUNCTION,     "Function not supported" },
 463	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 464	{ APM_BAD_STATE,	"Unable to enter requested state" },
 465/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 466	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 467	{ APM_NOT_PRESENT,	"No APM present" }
 468};
 469#define ERROR_COUNT	ARRAY_SIZE(error_table)
 470
 471/**
 472 *	apm_error	-	display an APM error
 473 *	@str: information string
 474 *	@err: APM BIOS return code
 475 *
 476 *	Write a meaningful log entry to the kernel log in the event of
 477 *	an APM error.  Note that this also handles (negative) kernel errors.
 478 */
 479
 480static void apm_error(char *str, int err)
 481{
 482	int i;
 483
 484	for (i = 0; i < ERROR_COUNT; i++)
 485		if (error_table[i].key == err)
 486			break;
 487	if (i < ERROR_COUNT)
 488		printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
 489	else if (err < 0)
 490		printk(KERN_NOTICE "apm: %s: linux error code %i\n", str, err);
 491	else
 492		printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
 493		       str, err);
 494}
 495
 496/*
 497 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 498 * apm_info.allow_ints, we are being really paranoid here!  Not only
 499 * are interrupts disabled, but all the segment registers (except SS)
 500 * are saved and zeroed this means that if the BIOS tries to reference
 501 * any data without explicitly loading the segment registers, the kernel
 502 * will fault immediately rather than have some unforeseen circumstances
 503 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 504 * this depends on CS referring to the same physical memory as DS so that
 505 * DS can be zeroed before the call. Unfortunately, we can't do anything
 506 * about the stack segment/pointer.  Also, we tell the compiler that
 507 * everything could change.
 508 *
 509 * Also, we KNOW that for the non error case of apm_bios_call, there
 510 * is no useful data returned in the low order 8 bits of eax.
 511 */
 512
 513static inline unsigned long __apm_irq_save(void)
 514{
 515	unsigned long flags;
 516	local_save_flags(flags);
 517	if (apm_info.allow_ints) {
 518		if (irqs_disabled_flags(flags))
 519			local_irq_enable();
 520	} else
 521		local_irq_disable();
 522
 523	return flags;
 524}
 525
 526#define apm_irq_save(flags) \
 527	do { flags = __apm_irq_save(); } while (0)
 528
 529static inline void apm_irq_restore(unsigned long flags)
 530{
 531	if (irqs_disabled_flags(flags))
 532		local_irq_disable();
 533	else if (irqs_disabled())
 534		local_irq_enable();
 535}
 536
 537#ifdef APM_ZERO_SEGS
 538#	define APM_DECL_SEGS \
 539		unsigned int saved_fs; unsigned int saved_gs;
 540#	define APM_DO_SAVE_SEGS \
 541		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 542#	define APM_DO_RESTORE_SEGS \
 543		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 544#else
 545#	define APM_DECL_SEGS
 546#	define APM_DO_SAVE_SEGS
 547#	define APM_DO_RESTORE_SEGS
 548#endif
 549
 550struct apm_bios_call {
 551	u32 func;
 552	/* In and out */
 553	u32 ebx;
 554	u32 ecx;
 555	/* Out only */
 556	u32 eax;
 557	u32 edx;
 558	u32 esi;
 559
 560	/* Error: -ENOMEM, or bits 8-15 of eax */
 561	int err;
 562};
 563
 564/**
 565 *	__apm_bios_call - Make an APM BIOS 32bit call
 566 *	@_call: pointer to struct apm_bios_call.
 567 *
 568 *	Make an APM call using the 32bit protected mode interface. The
 569 *	caller is responsible for knowing if APM BIOS is configured and
 570 *	enabled. This call can disable interrupts for a long period of
 571 *	time on some laptops.  The return value is in AH and the carry
 572 *	flag is loaded into AL.  If there is an error, then the error
 573 *	code is returned in AH (bits 8-15 of eax) and this function
 574 *	returns non-zero.
 575 *
 576 *	Note: this makes the call on the current CPU.
 577 */
 578static long __apm_bios_call(void *_call)
 579{
 580	APM_DECL_SEGS
 581	unsigned long		flags;
 582	int			cpu;
 583	struct desc_struct	save_desc_40;
 584	struct desc_struct	*gdt;
 585	struct apm_bios_call	*call = _call;
 
 586
 587	cpu = get_cpu();
 588	BUG_ON(cpu != 0);
 589	gdt = get_cpu_gdt_table(cpu);
 590	save_desc_40 = gdt[0x40 / 8];
 591	gdt[0x40 / 8] = bad_bios_desc;
 592
 593	apm_irq_save(flags);
 
 
 594	APM_DO_SAVE_SEGS;
 595	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 596			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 597			  &call->esi);
 598	APM_DO_RESTORE_SEGS;
 
 
 599	apm_irq_restore(flags);
 600	gdt[0x40 / 8] = save_desc_40;
 601	put_cpu();
 602
 603	return call->eax & 0xff;
 604}
 605
 606/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 607static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 608{
 609	int ret;
 610
 611	/* Don't bother with work_on_cpu in the common case, so we don't
 612	 * have to worry about OOM or overhead. */
 613	if (get_cpu() == 0) {
 614		ret = fn(call);
 615		put_cpu();
 616	} else {
 617		put_cpu();
 618		ret = work_on_cpu(0, fn, call);
 619	}
 620
 621	/* work_on_cpu can fail with -ENOMEM */
 622	if (ret < 0)
 623		call->err = ret;
 624	else
 625		call->err = (call->eax >> 8) & 0xff;
 626
 627	return ret;
 628}
 629
 630/**
 631 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 632 *	@call: the apm_bios_call registers.
 633 *
 634 *	If there is an error, it is returned in @call.err.
 635 */
 636static int apm_bios_call(struct apm_bios_call *call)
 637{
 638	return on_cpu0(__apm_bios_call, call);
 639}
 640
 641/**
 642 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 643 *	@_call: pointer to struct apm_bios_call.
 644 *
 645 *	Make a BIOS call that returns one value only, or just status.
 646 *	If there is an error, then the error code is returned in AH
 647 *	(bits 8-15 of eax) and this function returns non-zero (it can
 648 *	also return -ENOMEM). This is used for simpler BIOS operations.
 649 *	This call may hold interrupts off for a long time on some laptops.
 650 *
 651 *	Note: this makes the call on the current CPU.
 652 */
 653static long __apm_bios_call_simple(void *_call)
 654{
 655	u8			error;
 656	APM_DECL_SEGS
 657	unsigned long		flags;
 658	int			cpu;
 659	struct desc_struct	save_desc_40;
 660	struct desc_struct	*gdt;
 661	struct apm_bios_call	*call = _call;
 
 662
 663	cpu = get_cpu();
 664	BUG_ON(cpu != 0);
 665	gdt = get_cpu_gdt_table(cpu);
 666	save_desc_40 = gdt[0x40 / 8];
 667	gdt[0x40 / 8] = bad_bios_desc;
 668
 669	apm_irq_save(flags);
 
 
 670	APM_DO_SAVE_SEGS;
 671	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 672					 &call->eax);
 673	APM_DO_RESTORE_SEGS;
 
 
 674	apm_irq_restore(flags);
 675	gdt[0x40 / 8] = save_desc_40;
 676	put_cpu();
 677	return error;
 678}
 679
 680/**
 681 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 682 *	@func: APM function to invoke
 683 *	@ebx_in: EBX register value for BIOS call
 684 *	@ecx_in: ECX register value for BIOS call
 685 *	@eax: EAX register on return from the BIOS call
 686 *	@err: bits
 687 *
 688 *	Make a BIOS call that returns one value only, or just status.
 689 *	If there is an error, then the error code is returned in @err
 690 *	and this function returns non-zero. This is used for simpler
 691 *	BIOS operations.  This call may hold interrupts off for a long
 692 *	time on some laptops.
 693 */
 694static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 695				int *err)
 696{
 697	struct apm_bios_call call;
 698	int ret;
 699
 700	call.func = func;
 701	call.ebx = ebx_in;
 702	call.ecx = ecx_in;
 703
 704	ret = on_cpu0(__apm_bios_call_simple, &call);
 705	*eax = call.eax;
 706	*err = call.err;
 707	return ret;
 708}
 709
 710/**
 711 *	apm_driver_version	-	APM driver version
 712 *	@val:	loaded with the APM version on return
 713 *
 714 *	Retrieve the APM version supported by the BIOS. This is only
 715 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 716 *	probably present.
 717 *
 718 *	On entry val should point to a value indicating the APM driver
 719 *	version with the high byte being the major and the low byte the
 720 *	minor number both in BCD
 721 *
 722 *	On return it will hold the BIOS revision supported in the
 723 *	same format.
 724 */
 725
 726static int apm_driver_version(u_short *val)
 727{
 728	u32 eax;
 729	int err;
 730
 731	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 732		return err;
 733	*val = eax;
 734	return APM_SUCCESS;
 735}
 736
 737/**
 738 *	apm_get_event	-	get an APM event from the BIOS
 739 *	@event: pointer to the event
 740 *	@info: point to the event information
 741 *
 742 *	The APM BIOS provides a polled information for event
 743 *	reporting. The BIOS expects to be polled at least every second
 744 *	when events are pending. When a message is found the caller should
 745 *	poll until no more messages are present.  However, this causes
 746 *	problems on some laptops where a suspend event notification is
 747 *	not cleared until it is acknowledged.
 748 *
 749 *	Additional information is returned in the info pointer, providing
 750 *	that APM 1.2 is in use. If no messges are pending the value 0x80
 751 *	is returned (No power management events pending).
 752 */
 753static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 754{
 755	struct apm_bios_call call;
 756
 757	call.func = APM_FUNC_GET_EVENT;
 758	call.ebx = call.ecx = 0;
 759
 760	if (apm_bios_call(&call))
 761		return call.err;
 762
 763	*event = call.ebx;
 764	if (apm_info.connection_version < 0x0102)
 765		*info = ~0; /* indicate info not valid */
 766	else
 767		*info = call.ecx;
 768	return APM_SUCCESS;
 769}
 770
 771/**
 772 *	set_power_state	-	set the power management state
 773 *	@what: which items to transition
 774 *	@state: state to transition to
 775 *
 776 *	Request an APM change of state for one or more system devices. The
 777 *	processor state must be transitioned last of all. what holds the
 778 *	class of device in the upper byte and the device number (0xFF for
 779 *	all) for the object to be transitioned.
 780 *
 781 *	The state holds the state to transition to, which may in fact
 782 *	be an acceptance of a BIOS requested state change.
 783 */
 784
 785static int set_power_state(u_short what, u_short state)
 786{
 787	u32 eax;
 788	int err;
 789
 790	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 791		return err;
 792	return APM_SUCCESS;
 793}
 794
 795/**
 796 *	set_system_power_state - set system wide power state
 797 *	@state: which state to enter
 798 *
 799 *	Transition the entire system into a new APM power state.
 800 */
 801
 802static int set_system_power_state(u_short state)
 803{
 804	return set_power_state(APM_DEVICE_ALL, state);
 805}
 806
 807/**
 808 *	apm_do_idle	-	perform power saving
 809 *
 810 *	This function notifies the BIOS that the processor is (in the view
 811 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 812 *	to handle the idle request. On a success the function returns 1
 813 *	if the BIOS did clock slowing or 0 otherwise.
 814 */
 815
 816static int apm_do_idle(void)
 817{
 818	u32 eax;
 819	u8 ret = 0;
 820	int idled = 0;
 821	int polling;
 822	int err = 0;
 823
 824	polling = !!(current_thread_info()->status & TS_POLLING);
 825	if (polling) {
 826		current_thread_info()->status &= ~TS_POLLING;
 827		/*
 828		 * TS_POLLING-cleared state must be visible before we
 829		 * test NEED_RESCHED:
 830		 */
 831		smp_mb();
 832	}
 833	if (!need_resched()) {
 834		idled = 1;
 835		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 836	}
 837	if (polling)
 838		current_thread_info()->status |= TS_POLLING;
 839
 840	if (!idled)
 841		return 0;
 842
 843	if (ret) {
 844		static unsigned long t;
 845
 846		/* This always fails on some SMP boards running UP kernels.
 847		 * Only report the failure the first 5 times.
 848		 */
 849		if (++t < 5) {
 850			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 851			t = jiffies;
 852		}
 853		return -1;
 854	}
 855	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 856	return clock_slowed;
 857}
 858
 859/**
 860 *	apm_do_busy	-	inform the BIOS the CPU is busy
 861 *
 862 *	Request that the BIOS brings the CPU back to full performance.
 863 */
 864
 865static void apm_do_busy(void)
 866{
 867	u32 dummy;
 868	int err;
 869
 870	if (clock_slowed || ALWAYS_CALL_BUSY) {
 871		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 872		clock_slowed = 0;
 873	}
 874}
 875
 876/*
 877 * If no process has really been interested in
 878 * the CPU for some time, we want to call BIOS
 879 * power management - we probably want
 880 * to conserve power.
 881 */
 882#define IDLE_CALC_LIMIT	(HZ * 100)
 883#define IDLE_LEAKY_MAX	16
 884
 885static void (*original_pm_idle)(void) __read_mostly;
 886
 887/**
 888 * apm_cpu_idle		-	cpu idling for APM capable Linux
 889 *
 890 * This is the idling function the kernel executes when APM is available. It
 891 * tries to do BIOS powermanagement based on the average system idle time.
 892 * Furthermore it calls the system default idle routine.
 893 */
 894
 895static void apm_cpu_idle(void)
 
 896{
 897	static int use_apm_idle; /* = 0 */
 898	static unsigned int last_jiffies; /* = 0 */
 899	static unsigned int last_stime; /* = 0 */
 
 900
 901	int apm_idle_done = 0;
 902	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 903	unsigned int bucket;
 904
 905	WARN_ONCE(1, "deprecated apm_cpu_idle will be deleted in 2012");
 906recalc:
 
 907	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 908		use_apm_idle = 0;
 909		last_jiffies = jiffies;
 910		last_stime = current->stime;
 911	} else if (jiffies_since_last_check > idle_period) {
 912		unsigned int idle_percentage;
 913
 914		idle_percentage = current->stime - last_stime;
 915		idle_percentage *= 100;
 916		idle_percentage /= jiffies_since_last_check;
 917		use_apm_idle = (idle_percentage > idle_threshold);
 918		if (apm_info.forbid_idle)
 919			use_apm_idle = 0;
 920		last_jiffies = jiffies;
 921		last_stime = current->stime;
 922	}
 923
 
 
 
 924	bucket = IDLE_LEAKY_MAX;
 925
 926	while (!need_resched()) {
 927		if (use_apm_idle) {
 928			unsigned int t;
 929
 930			t = jiffies;
 931			switch (apm_do_idle()) {
 932			case 0:
 933				apm_idle_done = 1;
 934				if (t != jiffies) {
 935					if (bucket) {
 936						bucket = IDLE_LEAKY_MAX;
 937						continue;
 938					}
 939				} else if (bucket) {
 940					bucket--;
 941					continue;
 942				}
 943				break;
 944			case 1:
 945				apm_idle_done = 1;
 946				break;
 947			default: /* BIOS refused */
 948				break;
 949			}
 950		}
 951		if (original_pm_idle)
 952			original_pm_idle();
 953		else
 954			default_idle();
 955		local_irq_disable();
 956		jiffies_since_last_check = jiffies - last_jiffies;
 957		if (jiffies_since_last_check > idle_period)
 958			goto recalc;
 959	}
 960
 961	if (apm_idle_done)
 962		apm_do_busy();
 963
 964	local_irq_enable();
 965}
 966
 967/**
 968 *	apm_power_off	-	ask the BIOS to power off
 969 *
 970 *	Handle the power off sequence. This is the one piece of code we
 971 *	will execute even on SMP machines. In order to deal with BIOS
 972 *	bugs we support real mode APM BIOS power off calls. We also make
 973 *	the SMP call on CPU0 as some systems will only honour this call
 974 *	on their first cpu.
 975 */
 976
 977static void apm_power_off(void)
 978{
 979	/* Some bioses don't like being called from CPU != 0 */
 980	if (apm_info.realmode_power_off) {
 981		set_cpus_allowed_ptr(current, cpumask_of(0));
 982		machine_real_restart(MRR_APM);
 983	} else {
 984		(void)set_system_power_state(APM_STATE_OFF);
 985	}
 986}
 987
 988#ifdef CONFIG_APM_DO_ENABLE
 989
 990/**
 991 *	apm_enable_power_management - enable BIOS APM power management
 992 *	@enable: enable yes/no
 993 *
 994 *	Enable or disable the APM BIOS power services.
 995 */
 996
 997static int apm_enable_power_management(int enable)
 998{
 999	u32 eax;
1000	int err;
1001
1002	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1003		return APM_NOT_ENGAGED;
1004	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1005				 enable, &eax, &err))
1006		return err;
1007	if (enable)
1008		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1009	else
1010		apm_info.bios.flags |= APM_BIOS_DISABLED;
1011	return APM_SUCCESS;
1012}
1013#endif
1014
1015/**
1016 *	apm_get_power_status	-	get current power state
1017 *	@status: returned status
1018 *	@bat: battery info
1019 *	@life: estimated life
1020 *
1021 *	Obtain the current power status from the APM BIOS. We return a
1022 *	status which gives the rough battery status, and current power
1023 *	source. The bat value returned give an estimate as a percentage
1024 *	of life and a status value for the battery. The estimated life
1025 *	if reported is a lifetime in secodnds/minutes at current powwer
1026 *	consumption.
1027 */
1028
1029static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1030{
1031	struct apm_bios_call call;
1032
1033	call.func = APM_FUNC_GET_STATUS;
1034	call.ebx = APM_DEVICE_ALL;
1035	call.ecx = 0;
1036
1037	if (apm_info.get_power_status_broken)
1038		return APM_32_UNSUPPORTED;
1039	if (apm_bios_call(&call))
 
 
1040		return call.err;
 
1041	*status = call.ebx;
1042	*bat = call.ecx;
1043	if (apm_info.get_power_status_swabinminutes) {
1044		*life = swab16((u16)call.edx);
1045		*life |= 0x8000;
1046	} else
1047		*life = call.edx;
1048	return APM_SUCCESS;
1049}
1050
1051#if 0
1052static int apm_get_battery_status(u_short which, u_short *status,
1053				  u_short *bat, u_short *life, u_short *nbat)
1054{
1055	u32 eax;
1056	u32 ebx;
1057	u32 ecx;
1058	u32 edx;
1059	u32 esi;
1060
1061	if (apm_info.connection_version < 0x0102) {
1062		/* pretend we only have one battery. */
1063		if (which != 1)
1064			return APM_BAD_DEVICE;
1065		*nbat = 1;
1066		return apm_get_power_status(status, bat, life);
1067	}
1068
1069	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1070			  &ebx, &ecx, &edx, &esi))
1071		return (eax >> 8) & 0xff;
1072	*status = ebx;
1073	*bat = ecx;
1074	*life = edx;
1075	*nbat = esi;
1076	return APM_SUCCESS;
1077}
1078#endif
1079
1080/**
1081 *	apm_engage_power_management	-	enable PM on a device
1082 *	@device: identity of device
1083 *	@enable: on/off
1084 *
1085 *	Activate or deactive power management on either a specific device
1086 *	or the entire system (%APM_DEVICE_ALL).
1087 */
1088
1089static int apm_engage_power_management(u_short device, int enable)
1090{
1091	u32 eax;
1092	int err;
1093
1094	if ((enable == 0) && (device == APM_DEVICE_ALL)
1095	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1096		return APM_DISABLED;
1097	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1098				 &eax, &err))
1099		return err;
1100	if (device == APM_DEVICE_ALL) {
1101		if (enable)
1102			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1103		else
1104			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1105	}
1106	return APM_SUCCESS;
1107}
1108
1109#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1110
1111/**
1112 *	apm_console_blank	-	blank the display
1113 *	@blank: on/off
1114 *
1115 *	Attempt to blank the console, firstly by blanking just video device
1116 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1117 *	all video devices. Typically the BIOS will do laptop backlight and
1118 *	monitor powerdown for us.
1119 */
1120
1121static int apm_console_blank(int blank)
1122{
1123	int error = APM_NOT_ENGAGED; /* silence gcc */
1124	int i;
1125	u_short state;
1126	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1127
1128	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1129
1130	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1131		error = set_power_state(dev[i], state);
1132
1133		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1134			return 1;
1135
1136		if (error == APM_NOT_ENGAGED)
1137			break;
1138	}
1139
1140	if (error == APM_NOT_ENGAGED) {
1141		static int tried;
1142		int eng_error;
1143		if (tried++ == 0) {
1144			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1145			if (eng_error) {
1146				apm_error("set display", error);
1147				apm_error("engage interface", eng_error);
1148				return 0;
1149			} else
1150				return apm_console_blank(blank);
1151		}
1152	}
1153	apm_error("set display", error);
1154	return 0;
1155}
1156#endif
1157
1158static int queue_empty(struct apm_user *as)
1159{
1160	return as->event_head == as->event_tail;
1161}
1162
1163static apm_event_t get_queued_event(struct apm_user *as)
1164{
1165	if (++as->event_tail >= APM_MAX_EVENTS)
1166		as->event_tail = 0;
1167	return as->events[as->event_tail];
1168}
1169
1170static void queue_event(apm_event_t event, struct apm_user *sender)
1171{
1172	struct apm_user *as;
1173
1174	spin_lock(&user_list_lock);
1175	if (user_list == NULL)
1176		goto out;
1177	for (as = user_list; as != NULL; as = as->next) {
1178		if ((as == sender) || (!as->reader))
1179			continue;
1180		if (++as->event_head >= APM_MAX_EVENTS)
1181			as->event_head = 0;
1182
1183		if (as->event_head == as->event_tail) {
1184			static int notified;
1185
1186			if (notified++ == 0)
1187			    printk(KERN_ERR "apm: an event queue overflowed\n");
1188			if (++as->event_tail >= APM_MAX_EVENTS)
1189				as->event_tail = 0;
1190		}
1191		as->events[as->event_head] = event;
1192		if (!as->suser || !as->writer)
1193			continue;
1194		switch (event) {
1195		case APM_SYS_SUSPEND:
1196		case APM_USER_SUSPEND:
1197			as->suspends_pending++;
1198			suspends_pending++;
1199			break;
1200
1201		case APM_SYS_STANDBY:
1202		case APM_USER_STANDBY:
1203			as->standbys_pending++;
1204			standbys_pending++;
1205			break;
1206		}
1207	}
1208	wake_up_interruptible(&apm_waitqueue);
1209out:
1210	spin_unlock(&user_list_lock);
1211}
1212
1213static void reinit_timer(void)
1214{
1215#ifdef INIT_TIMER_AFTER_SUSPEND
1216	unsigned long flags;
1217
1218	raw_spin_lock_irqsave(&i8253_lock, flags);
1219	/* set the clock to HZ */
1220	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1221	udelay(10);
1222	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1223	udelay(10);
1224	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1225	udelay(10);
1226	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1227#endif
1228}
1229
1230static int suspend(int vetoable)
1231{
1232	int err;
1233	struct apm_user	*as;
1234
1235	dpm_suspend_start(PMSG_SUSPEND);
1236	dpm_suspend_end(PMSG_SUSPEND);
1237
1238	local_irq_disable();
1239	syscore_suspend();
1240
1241	local_irq_enable();
1242
1243	save_processor_state();
1244	err = set_system_power_state(APM_STATE_SUSPEND);
1245	ignore_normal_resume = 1;
1246	restore_processor_state();
1247
1248	local_irq_disable();
1249	reinit_timer();
1250
1251	if (err == APM_NO_ERROR)
1252		err = APM_SUCCESS;
1253	if (err != APM_SUCCESS)
1254		apm_error("suspend", err);
1255	err = (err == APM_SUCCESS) ? 0 : -EIO;
1256
1257	syscore_resume();
1258	local_irq_enable();
1259
1260	dpm_resume_start(PMSG_RESUME);
1261	dpm_resume_end(PMSG_RESUME);
1262
1263	queue_event(APM_NORMAL_RESUME, NULL);
1264	spin_lock(&user_list_lock);
1265	for (as = user_list; as != NULL; as = as->next) {
1266		as->suspend_wait = 0;
1267		as->suspend_result = err;
1268	}
1269	spin_unlock(&user_list_lock);
1270	wake_up_interruptible(&apm_suspend_waitqueue);
1271	return err;
1272}
1273
1274static void standby(void)
1275{
1276	int err;
1277
1278	dpm_suspend_end(PMSG_SUSPEND);
1279
1280	local_irq_disable();
1281	syscore_suspend();
1282	local_irq_enable();
1283
1284	err = set_system_power_state(APM_STATE_STANDBY);
1285	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1286		apm_error("standby", err);
1287
1288	local_irq_disable();
1289	syscore_resume();
1290	local_irq_enable();
1291
1292	dpm_resume_start(PMSG_RESUME);
1293}
1294
1295static apm_event_t get_event(void)
1296{
1297	int error;
1298	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1299	apm_eventinfo_t	info;
1300
1301	static int notified;
1302
1303	/* we don't use the eventinfo */
1304	error = apm_get_event(&event, &info);
1305	if (error == APM_SUCCESS)
1306		return event;
1307
1308	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1309		apm_error("get_event", error);
1310
1311	return 0;
1312}
1313
1314static void check_events(void)
1315{
1316	apm_event_t event;
1317	static unsigned long last_resume;
1318	static int ignore_bounce;
1319
1320	while ((event = get_event()) != 0) {
1321		if (debug) {
1322			if (event <= NR_APM_EVENT_NAME)
1323				printk(KERN_DEBUG "apm: received %s notify\n",
1324				       apm_event_name[event - 1]);
1325			else
1326				printk(KERN_DEBUG "apm: received unknown "
1327				       "event 0x%02x\n", event);
1328		}
1329		if (ignore_bounce
1330		    && (time_after(jiffies, last_resume + bounce_interval)))
1331			ignore_bounce = 0;
1332
1333		switch (event) {
1334		case APM_SYS_STANDBY:
1335		case APM_USER_STANDBY:
1336			queue_event(event, NULL);
1337			if (standbys_pending <= 0)
1338				standby();
1339			break;
1340
1341		case APM_USER_SUSPEND:
1342#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1343			if (apm_info.connection_version > 0x100)
1344				set_system_power_state(APM_STATE_REJECT);
1345			break;
1346#endif
1347		case APM_SYS_SUSPEND:
1348			if (ignore_bounce) {
1349				if (apm_info.connection_version > 0x100)
1350					set_system_power_state(APM_STATE_REJECT);
1351				break;
1352			}
1353			/*
1354			 * If we are already processing a SUSPEND,
1355			 * then further SUSPEND events from the BIOS
1356			 * will be ignored.  We also return here to
1357			 * cope with the fact that the Thinkpads keep
1358			 * sending a SUSPEND event until something else
1359			 * happens!
1360			 */
1361			if (ignore_sys_suspend)
1362				return;
1363			ignore_sys_suspend = 1;
1364			queue_event(event, NULL);
1365			if (suspends_pending <= 0)
1366				(void) suspend(1);
1367			break;
1368
1369		case APM_NORMAL_RESUME:
1370		case APM_CRITICAL_RESUME:
1371		case APM_STANDBY_RESUME:
1372			ignore_sys_suspend = 0;
1373			last_resume = jiffies;
1374			ignore_bounce = 1;
1375			if ((event != APM_NORMAL_RESUME)
1376			    || (ignore_normal_resume == 0)) {
1377				dpm_resume_end(PMSG_RESUME);
1378				queue_event(event, NULL);
1379			}
1380			ignore_normal_resume = 0;
1381			break;
1382
1383		case APM_CAPABILITY_CHANGE:
1384		case APM_LOW_BATTERY:
1385		case APM_POWER_STATUS_CHANGE:
1386			queue_event(event, NULL);
1387			/* If needed, notify drivers here */
1388			break;
1389
1390		case APM_UPDATE_TIME:
1391			break;
1392
1393		case APM_CRITICAL_SUSPEND:
1394			/*
1395			 * We are not allowed to reject a critical suspend.
1396			 */
1397			(void)suspend(0);
1398			break;
1399		}
1400	}
1401}
1402
1403static void apm_event_handler(void)
1404{
1405	static int pending_count = 4;
1406	int err;
1407
1408	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1409		if ((apm_info.connection_version > 0x100) &&
1410		    (pending_count-- <= 0)) {
1411			pending_count = 4;
1412			if (debug)
1413				printk(KERN_DEBUG "apm: setting state busy\n");
1414			err = set_system_power_state(APM_STATE_BUSY);
1415			if (err)
1416				apm_error("busy", err);
1417		}
1418	} else
1419		pending_count = 4;
1420	check_events();
1421}
1422
1423/*
1424 * This is the APM thread main loop.
1425 */
1426
1427static void apm_mainloop(void)
1428{
1429	DECLARE_WAITQUEUE(wait, current);
1430
1431	add_wait_queue(&apm_waitqueue, &wait);
1432	set_current_state(TASK_INTERRUPTIBLE);
1433	for (;;) {
1434		schedule_timeout(APM_CHECK_TIMEOUT);
1435		if (kthread_should_stop())
1436			break;
1437		/*
1438		 * Ok, check all events, check for idle (and mark us sleeping
1439		 * so as not to count towards the load average)..
1440		 */
1441		set_current_state(TASK_INTERRUPTIBLE);
1442		apm_event_handler();
1443	}
1444	remove_wait_queue(&apm_waitqueue, &wait);
1445}
1446
1447static int check_apm_user(struct apm_user *as, const char *func)
1448{
1449	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1450		printk(KERN_ERR "apm: %s passed bad filp\n", func);
1451		return 1;
1452	}
1453	return 0;
1454}
1455
1456static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1457{
1458	struct apm_user *as;
1459	int i;
1460	apm_event_t event;
1461
1462	as = fp->private_data;
1463	if (check_apm_user(as, "read"))
1464		return -EIO;
1465	if ((int)count < sizeof(apm_event_t))
1466		return -EINVAL;
1467	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1468		return -EAGAIN;
1469	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1470	i = count;
1471	while ((i >= sizeof(event)) && !queue_empty(as)) {
1472		event = get_queued_event(as);
1473		if (copy_to_user(buf, &event, sizeof(event))) {
1474			if (i < count)
1475				break;
1476			return -EFAULT;
1477		}
1478		switch (event) {
1479		case APM_SYS_SUSPEND:
1480		case APM_USER_SUSPEND:
1481			as->suspends_read++;
1482			break;
1483
1484		case APM_SYS_STANDBY:
1485		case APM_USER_STANDBY:
1486			as->standbys_read++;
1487			break;
1488		}
1489		buf += sizeof(event);
1490		i -= sizeof(event);
1491	}
1492	if (i < count)
1493		return count - i;
1494	if (signal_pending(current))
1495		return -ERESTARTSYS;
1496	return 0;
1497}
1498
1499static unsigned int do_poll(struct file *fp, poll_table *wait)
1500{
1501	struct apm_user *as;
1502
1503	as = fp->private_data;
1504	if (check_apm_user(as, "poll"))
1505		return 0;
1506	poll_wait(fp, &apm_waitqueue, wait);
1507	if (!queue_empty(as))
1508		return POLLIN | POLLRDNORM;
1509	return 0;
1510}
1511
1512static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1513{
1514	struct apm_user *as;
1515	int ret;
1516
1517	as = filp->private_data;
1518	if (check_apm_user(as, "ioctl"))
1519		return -EIO;
1520	if (!as->suser || !as->writer)
1521		return -EPERM;
1522	switch (cmd) {
1523	case APM_IOC_STANDBY:
1524		mutex_lock(&apm_mutex);
1525		if (as->standbys_read > 0) {
1526			as->standbys_read--;
1527			as->standbys_pending--;
1528			standbys_pending--;
1529		} else
1530			queue_event(APM_USER_STANDBY, as);
1531		if (standbys_pending <= 0)
1532			standby();
1533		mutex_unlock(&apm_mutex);
1534		break;
1535	case APM_IOC_SUSPEND:
1536		mutex_lock(&apm_mutex);
1537		if (as->suspends_read > 0) {
1538			as->suspends_read--;
1539			as->suspends_pending--;
1540			suspends_pending--;
1541		} else
1542			queue_event(APM_USER_SUSPEND, as);
1543		if (suspends_pending <= 0) {
1544			ret = suspend(1);
1545			mutex_unlock(&apm_mutex);
1546		} else {
1547			as->suspend_wait = 1;
1548			mutex_unlock(&apm_mutex);
1549			wait_event_interruptible(apm_suspend_waitqueue,
1550					as->suspend_wait == 0);
1551			ret = as->suspend_result;
1552		}
1553		return ret;
1554	default:
1555		return -ENOTTY;
1556	}
1557	return 0;
1558}
1559
1560static int do_release(struct inode *inode, struct file *filp)
1561{
1562	struct apm_user *as;
1563
1564	as = filp->private_data;
1565	if (check_apm_user(as, "release"))
1566		return 0;
1567	filp->private_data = NULL;
1568	if (as->standbys_pending > 0) {
1569		standbys_pending -= as->standbys_pending;
1570		if (standbys_pending <= 0)
1571			standby();
1572	}
1573	if (as->suspends_pending > 0) {
1574		suspends_pending -= as->suspends_pending;
1575		if (suspends_pending <= 0)
1576			(void) suspend(1);
1577	}
1578	spin_lock(&user_list_lock);
1579	if (user_list == as)
1580		user_list = as->next;
1581	else {
1582		struct apm_user *as1;
1583
1584		for (as1 = user_list;
1585		     (as1 != NULL) && (as1->next != as);
1586		     as1 = as1->next)
1587			;
1588		if (as1 == NULL)
1589			printk(KERN_ERR "apm: filp not in user list\n");
1590		else
1591			as1->next = as->next;
1592	}
1593	spin_unlock(&user_list_lock);
1594	kfree(as);
1595	return 0;
1596}
1597
1598static int do_open(struct inode *inode, struct file *filp)
1599{
1600	struct apm_user *as;
1601
1602	as = kmalloc(sizeof(*as), GFP_KERNEL);
1603	if (as == NULL) {
1604		printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1605		       sizeof(*as));
1606		return -ENOMEM;
1607	}
1608	as->magic = APM_BIOS_MAGIC;
1609	as->event_tail = as->event_head = 0;
1610	as->suspends_pending = as->standbys_pending = 0;
1611	as->suspends_read = as->standbys_read = 0;
1612	/*
1613	 * XXX - this is a tiny bit broken, when we consider BSD
1614	 * process accounting. If the device is opened by root, we
1615	 * instantly flag that we used superuser privs. Who knows,
1616	 * we might close the device immediately without doing a
1617	 * privileged operation -- cevans
1618	 */
1619	as->suser = capable(CAP_SYS_ADMIN);
1620	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1621	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1622	spin_lock(&user_list_lock);
1623	as->next = user_list;
1624	user_list = as;
1625	spin_unlock(&user_list_lock);
1626	filp->private_data = as;
1627	return 0;
1628}
1629
 
1630static int proc_apm_show(struct seq_file *m, void *v)
1631{
1632	unsigned short	bx;
1633	unsigned short	cx;
1634	unsigned short	dx;
1635	int		error;
1636	unsigned short  ac_line_status = 0xff;
1637	unsigned short  battery_status = 0xff;
1638	unsigned short  battery_flag   = 0xff;
1639	int		percentage     = -1;
1640	int             time_units     = -1;
1641	char            *units         = "?";
1642
1643	if ((num_online_cpus() == 1) &&
1644	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1645		ac_line_status = (bx >> 8) & 0xff;
1646		battery_status = bx & 0xff;
1647		if ((cx & 0xff) != 0xff)
1648			percentage = cx & 0xff;
1649
1650		if (apm_info.connection_version > 0x100) {
1651			battery_flag = (cx >> 8) & 0xff;
1652			if (dx != 0xffff) {
1653				units = (dx & 0x8000) ? "min" : "sec";
1654				time_units = dx & 0x7fff;
1655			}
1656		}
1657	}
1658	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1659	   from the Get Power Status (0x0a) call unless otherwise noted.
1660
1661	   0) Linux driver version (this will change if format changes)
1662	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1663	   2) APM flags from APM Installation Check (0x00):
1664	      bit 0: APM_16_BIT_SUPPORT
1665	      bit 1: APM_32_BIT_SUPPORT
1666	      bit 2: APM_IDLE_SLOWS_CLOCK
1667	      bit 3: APM_BIOS_DISABLED
1668	      bit 4: APM_BIOS_DISENGAGED
1669	   3) AC line status
1670	      0x00: Off-line
1671	      0x01: On-line
1672	      0x02: On backup power (BIOS >= 1.1 only)
1673	      0xff: Unknown
1674	   4) Battery status
1675	      0x00: High
1676	      0x01: Low
1677	      0x02: Critical
1678	      0x03: Charging
1679	      0x04: Selected battery not present (BIOS >= 1.2 only)
1680	      0xff: Unknown
1681	   5) Battery flag
1682	      bit 0: High
1683	      bit 1: Low
1684	      bit 2: Critical
1685	      bit 3: Charging
1686	      bit 7: No system battery
1687	      0xff: Unknown
1688	   6) Remaining battery life (percentage of charge):
1689	      0-100: valid
1690	      -1: Unknown
1691	   7) Remaining battery life (time units):
1692	      Number of remaining minutes or seconds
1693	      -1: Unknown
1694	   8) min = minutes; sec = seconds */
1695
1696	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1697		   driver_version,
1698		   (apm_info.bios.version >> 8) & 0xff,
1699		   apm_info.bios.version & 0xff,
1700		   apm_info.bios.flags,
1701		   ac_line_status,
1702		   battery_status,
1703		   battery_flag,
1704		   percentage,
1705		   time_units,
1706		   units);
1707	return 0;
1708}
1709
1710static int proc_apm_open(struct inode *inode, struct file *file)
1711{
1712	return single_open(file, proc_apm_show, NULL);
1713}
1714
1715static const struct file_operations apm_file_ops = {
1716	.owner		= THIS_MODULE,
1717	.open		= proc_apm_open,
1718	.read		= seq_read,
1719	.llseek		= seq_lseek,
1720	.release	= single_release,
1721};
1722
1723static int apm(void *unused)
1724{
1725	unsigned short	bx;
1726	unsigned short	cx;
1727	unsigned short	dx;
1728	int		error;
1729	char 		*power_stat;
1730	char 		*bat_stat;
1731
1732	/* 2002/08/01 - WT
1733	 * This is to avoid random crashes at boot time during initialization
1734	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1735	 * Some bioses don't like being called from CPU != 0.
1736	 * Method suggested by Ingo Molnar.
1737	 */
1738	set_cpus_allowed_ptr(current, cpumask_of(0));
1739	BUG_ON(smp_processor_id() != 0);
1740
1741	if (apm_info.connection_version == 0) {
1742		apm_info.connection_version = apm_info.bios.version;
1743		if (apm_info.connection_version > 0x100) {
1744			/*
1745			 * We only support BIOSs up to version 1.2
1746			 */
1747			if (apm_info.connection_version > 0x0102)
1748				apm_info.connection_version = 0x0102;
1749			error = apm_driver_version(&apm_info.connection_version);
1750			if (error != APM_SUCCESS) {
1751				apm_error("driver version", error);
1752				/* Fall back to an APM 1.0 connection. */
1753				apm_info.connection_version = 0x100;
1754			}
1755		}
1756	}
1757
1758	if (debug)
1759		printk(KERN_INFO "apm: Connection version %d.%d\n",
1760			(apm_info.connection_version >> 8) & 0xff,
1761			apm_info.connection_version & 0xff);
1762
1763#ifdef CONFIG_APM_DO_ENABLE
1764	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1765		/*
1766		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1767		 * is booted with PM disabled but not in the docking station.
1768		 * Unfortunate ...
1769		 */
1770		error = apm_enable_power_management(1);
1771		if (error) {
1772			apm_error("enable power management", error);
1773			return -1;
1774		}
1775	}
1776#endif
1777
1778	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1779	    && (apm_info.connection_version > 0x0100)) {
1780		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1781		if (error) {
1782			apm_error("engage power management", error);
1783			return -1;
1784		}
1785	}
1786
1787	if (debug && (num_online_cpus() == 1 || smp)) {
1788		error = apm_get_power_status(&bx, &cx, &dx);
1789		if (error)
1790			printk(KERN_INFO "apm: power status not available\n");
1791		else {
1792			switch ((bx >> 8) & 0xff) {
1793			case 0:
1794				power_stat = "off line";
1795				break;
1796			case 1:
1797				power_stat = "on line";
1798				break;
1799			case 2:
1800				power_stat = "on backup power";
1801				break;
1802			default:
1803				power_stat = "unknown";
1804				break;
1805			}
1806			switch (bx & 0xff) {
1807			case 0:
1808				bat_stat = "high";
1809				break;
1810			case 1:
1811				bat_stat = "low";
1812				break;
1813			case 2:
1814				bat_stat = "critical";
1815				break;
1816			case 3:
1817				bat_stat = "charging";
1818				break;
1819			default:
1820				bat_stat = "unknown";
1821				break;
1822			}
1823			printk(KERN_INFO
1824			       "apm: AC %s, battery status %s, battery life ",
1825			       power_stat, bat_stat);
1826			if ((cx & 0xff) == 0xff)
1827				printk("unknown\n");
1828			else
1829				printk("%d%%\n", cx & 0xff);
1830			if (apm_info.connection_version > 0x100) {
1831				printk(KERN_INFO
1832				       "apm: battery flag 0x%02x, battery life ",
1833				       (cx >> 8) & 0xff);
1834				if (dx == 0xffff)
1835					printk("unknown\n");
1836				else
1837					printk("%d %s\n", dx & 0x7fff,
1838					       (dx & 0x8000) ?
1839					       "minutes" : "seconds");
1840			}
1841		}
1842	}
1843
1844	/* Install our power off handler.. */
1845	if (power_off)
1846		pm_power_off = apm_power_off;
1847
1848	if (num_online_cpus() == 1 || smp) {
1849#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1850		console_blank_hook = apm_console_blank;
1851#endif
1852		apm_mainloop();
1853#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1854		console_blank_hook = NULL;
1855#endif
1856	}
1857
1858	return 0;
1859}
1860
1861#ifndef MODULE
1862static int __init apm_setup(char *str)
1863{
1864	int invert;
1865
1866	while ((str != NULL) && (*str != '\0')) {
1867		if (strncmp(str, "off", 3) == 0)
1868			apm_disabled = 1;
1869		if (strncmp(str, "on", 2) == 0)
1870			apm_disabled = 0;
1871		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1872		    (strncmp(str, "bounce_interval=", 16) == 0))
1873			bounce_interval = simple_strtol(str + 16, NULL, 0);
1874		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1875		    (strncmp(str, "idle_threshold=", 15) == 0))
1876			idle_threshold = simple_strtol(str + 15, NULL, 0);
1877		if ((strncmp(str, "idle-period=", 12) == 0) ||
1878		    (strncmp(str, "idle_period=", 12) == 0))
1879			idle_period = simple_strtol(str + 12, NULL, 0);
1880		invert = (strncmp(str, "no-", 3) == 0) ||
1881			(strncmp(str, "no_", 3) == 0);
1882		if (invert)
1883			str += 3;
1884		if (strncmp(str, "debug", 5) == 0)
1885			debug = !invert;
1886		if ((strncmp(str, "power-off", 9) == 0) ||
1887		    (strncmp(str, "power_off", 9) == 0))
1888			power_off = !invert;
1889		if (strncmp(str, "smp", 3) == 0) {
1890			smp = !invert;
1891			idle_threshold = 100;
1892		}
1893		if ((strncmp(str, "allow-ints", 10) == 0) ||
1894		    (strncmp(str, "allow_ints", 10) == 0))
1895			apm_info.allow_ints = !invert;
1896		if ((strncmp(str, "broken-psr", 10) == 0) ||
1897		    (strncmp(str, "broken_psr", 10) == 0))
1898			apm_info.get_power_status_broken = !invert;
1899		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1900		    (strncmp(str, "realmode_power_off", 18) == 0))
1901			apm_info.realmode_power_off = !invert;
1902		str = strchr(str, ',');
1903		if (str != NULL)
1904			str += strspn(str, ", \t");
1905	}
1906	return 1;
1907}
1908
1909__setup("apm=", apm_setup);
1910#endif
1911
1912static const struct file_operations apm_bios_fops = {
1913	.owner		= THIS_MODULE,
1914	.read		= do_read,
1915	.poll		= do_poll,
1916	.unlocked_ioctl	= do_ioctl,
1917	.open		= do_open,
1918	.release	= do_release,
1919	.llseek		= noop_llseek,
1920};
1921
1922static struct miscdevice apm_device = {
1923	APM_MINOR_DEV,
1924	"apm_bios",
1925	&apm_bios_fops
1926};
1927
1928
1929/* Simple "print if true" callback */
1930static int __init print_if_true(const struct dmi_system_id *d)
1931{
1932	printk("%s\n", d->ident);
1933	return 0;
1934}
1935
1936/*
1937 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1938 * disabled before the suspend. Linux used to get terribly confused by that.
1939 */
1940static int __init broken_ps2_resume(const struct dmi_system_id *d)
1941{
1942	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1943	       "workaround hopefully not needed.\n", d->ident);
1944	return 0;
1945}
1946
1947/* Some bioses have a broken protected mode poweroff and need to use realmode */
1948static int __init set_realmode_power_off(const struct dmi_system_id *d)
1949{
1950	if (apm_info.realmode_power_off == 0) {
1951		apm_info.realmode_power_off = 1;
1952		printk(KERN_INFO "%s bios detected. "
1953		       "Using realmode poweroff only.\n", d->ident);
1954	}
1955	return 0;
1956}
1957
1958/* Some laptops require interrupts to be enabled during APM calls */
1959static int __init set_apm_ints(const struct dmi_system_id *d)
1960{
1961	if (apm_info.allow_ints == 0) {
1962		apm_info.allow_ints = 1;
1963		printk(KERN_INFO "%s machine detected. "
1964		       "Enabling interrupts during APM calls.\n", d->ident);
1965	}
1966	return 0;
1967}
1968
1969/* Some APM bioses corrupt memory or just plain do not work */
1970static int __init apm_is_horked(const struct dmi_system_id *d)
1971{
1972	if (apm_info.disabled == 0) {
1973		apm_info.disabled = 1;
1974		printk(KERN_INFO "%s machine detected. "
1975		       "Disabling APM.\n", d->ident);
1976	}
1977	return 0;
1978}
1979
1980static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1981{
1982	if (apm_info.disabled == 0) {
1983		apm_info.disabled = 1;
1984		printk(KERN_INFO "%s machine detected. "
1985		       "Disabling APM.\n", d->ident);
1986		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1987		printk(KERN_INFO "download from support.intel.com\n");
1988	}
1989	return 0;
1990}
1991
1992/* Some APM bioses hang on APM idle calls */
1993static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1994{
1995	if (apm_info.forbid_idle == 0) {
1996		apm_info.forbid_idle = 1;
1997		printk(KERN_INFO "%s machine detected. "
1998		       "Disabling APM idle calls.\n", d->ident);
1999	}
2000	return 0;
2001}
2002
2003/*
2004 *  Check for clue free BIOS implementations who use
2005 *  the following QA technique
2006 *
2007 *      [ Write BIOS Code ]<------
2008 *               |                ^
2009 *      < Does it Compile >----N--
2010 *               |Y               ^
2011 *	< Does it Boot Win98 >-N--
2012 *               |Y
2013 *           [Ship It]
2014 *
2015 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2016 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2017 */
2018static int __init broken_apm_power(const struct dmi_system_id *d)
2019{
2020	apm_info.get_power_status_broken = 1;
2021	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2022	       "disabling power status reporting.\n");
2023	return 0;
2024}
2025
2026/*
2027 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2028 * have this problem).
2029 */
2030static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2031{
2032	apm_info.get_power_status_swabinminutes = 1;
2033	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2034	       "in minutes and wrong byte order.\n");
2035	return 0;
2036}
2037
2038static struct dmi_system_id __initdata apm_dmi_table[] = {
2039	{
2040		print_if_true,
2041		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2042		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2043			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2044	},
2045	{	/* Handle problems with APM on the C600 */
2046		broken_ps2_resume, "Dell Latitude C600",
2047		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2048			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2049	},
2050	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2051		set_apm_ints, "Dell Latitude",
2052		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2053			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2054	},
2055	{	/* APM crashes */
2056		apm_is_horked, "Dell Inspiron 2500",
2057		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2058			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2059			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2060			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2061	},
2062	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2063		set_apm_ints, "Dell Inspiron", {
2064			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2065			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2066	},
2067	{	/* Handle problems with APM on Inspiron 5000e */
2068		broken_apm_power, "Dell Inspiron 5000e",
2069		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2070			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2071			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2072	},
2073	{	/* Handle problems with APM on Inspiron 2500 */
2074		broken_apm_power, "Dell Inspiron 2500",
2075		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2076			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2077			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2078	},
2079	{	/* APM crashes */
2080		apm_is_horked, "Dell Dimension 4100",
2081		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2082			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2083			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2084			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2085	},
2086	{	/* Allow interrupts during suspend on Compaq Laptops*/
2087		set_apm_ints, "Compaq 12XL125",
2088		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2089			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2090			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2091			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2092	},
2093	{	/* Allow interrupts during APM or the clock goes slow */
2094		set_apm_ints, "ASUSTeK",
2095		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2096			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2097	},
2098	{	/* APM blows on shutdown */
2099		apm_is_horked, "ABIT KX7-333[R]",
2100		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2101			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2102	},
2103	{	/* APM crashes */
2104		apm_is_horked, "Trigem Delhi3",
2105		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2106			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2107	},
2108	{	/* APM crashes */
2109		apm_is_horked, "Fujitsu-Siemens",
2110		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2111			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2112	},
2113	{	/* APM crashes */
2114		apm_is_horked_d850md, "Intel D850MD",
2115		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2116			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2117	},
2118	{	/* APM crashes */
2119		apm_is_horked, "Intel D810EMO",
2120		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2121			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2122	},
2123	{	/* APM crashes */
2124		apm_is_horked, "Dell XPS-Z",
2125		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2126			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2127			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2128	},
2129	{	/* APM crashes */
2130		apm_is_horked, "Sharp PC-PJ/AX",
2131		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2132			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2133			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2134			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2135	},
2136	{	/* APM crashes */
2137		apm_is_horked, "Dell Inspiron 2500",
2138		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2139			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2140			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2141			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2142	},
2143	{	/* APM idle hangs */
2144		apm_likes_to_melt, "Jabil AMD",
2145		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2146			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2147	},
2148	{	/* APM idle hangs */
2149		apm_likes_to_melt, "AMI Bios",
2150		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2151			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2152	},
2153	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2154		swab_apm_power_in_minutes, "Sony VAIO",
2155		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2156			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2157			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2158	},
2159	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2160		swab_apm_power_in_minutes, "Sony VAIO",
2161		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2162			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2163			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2164	},
2165	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2166		swab_apm_power_in_minutes, "Sony VAIO",
2167		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2168			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2169			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2170	},
2171	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2172		swab_apm_power_in_minutes, "Sony VAIO",
2173		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2174			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2175			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2176	},
2177	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2178		swab_apm_power_in_minutes, "Sony VAIO",
2179		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2180			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2181			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2182	},
2183	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2184		swab_apm_power_in_minutes, "Sony VAIO",
2185		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2186			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2187			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2188	},
2189	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2190		swab_apm_power_in_minutes, "Sony VAIO",
2191		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2192			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2193			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2194	},
2195	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2196		swab_apm_power_in_minutes, "Sony VAIO",
2197		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2198			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2199			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2200	},
2201	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2202		swab_apm_power_in_minutes, "Sony VAIO",
2203		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2204			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2205			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2206	},
2207	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2208		swab_apm_power_in_minutes, "Sony VAIO",
2209		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2211			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2212	},
2213
2214	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2215		swab_apm_power_in_minutes, "Sony VAIO",
2216		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2217			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2218			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2219	},
2220	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2221		swab_apm_power_in_minutes, "Sony VAIO",
2222		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2223			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2224			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2225	},
2226	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2227		swab_apm_power_in_minutes, "Sony VAIO",
2228		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2229			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2230			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2231	},
2232	{	/* broken PM poweroff bios */
2233		set_realmode_power_off, "Award Software v4.60 PGMA",
2234		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2235			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2236			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2237	},
2238
2239	/* Generic per vendor APM settings  */
2240
2241	{	/* Allow interrupts during suspend on IBM laptops */
2242		set_apm_ints, "IBM",
2243		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2244	},
2245
2246	{ }
2247};
2248
2249/*
2250 * Just start the APM thread. We do NOT want to do APM BIOS
2251 * calls from anything but the APM thread, if for no other reason
2252 * than the fact that we don't trust the APM BIOS. This way,
2253 * most common APM BIOS problems that lead to protection errors
2254 * etc will have at least some level of being contained...
2255 *
2256 * In short, if something bad happens, at least we have a choice
2257 * of just killing the apm thread..
2258 */
2259static int __init apm_init(void)
2260{
2261	struct desc_struct *gdt;
2262	int err;
2263
2264	dmi_check_system(apm_dmi_table);
2265
2266	if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2267		printk(KERN_INFO "apm: BIOS not found.\n");
2268		return -ENODEV;
2269	}
2270	printk(KERN_INFO
2271	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2272	       ((apm_info.bios.version >> 8) & 0xff),
2273	       (apm_info.bios.version & 0xff),
2274	       apm_info.bios.flags,
2275	       driver_version);
2276	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2277		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2278		return -ENODEV;
2279	}
2280
2281	if (allow_ints)
2282		apm_info.allow_ints = 1;
2283	if (broken_psr)
2284		apm_info.get_power_status_broken = 1;
2285	if (realmode_power_off)
2286		apm_info.realmode_power_off = 1;
2287	/* User can override, but default is to trust DMI */
2288	if (apm_disabled != -1)
2289		apm_info.disabled = apm_disabled;
2290
2291	/*
2292	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2293	 * but is reportedly a 1.0 BIOS.
2294	 */
2295	if (apm_info.bios.version == 0x001)
2296		apm_info.bios.version = 0x100;
2297
2298	/* BIOS < 1.2 doesn't set cseg_16_len */
2299	if (apm_info.bios.version < 0x102)
2300		apm_info.bios.cseg_16_len = 0; /* 64k */
2301
2302	if (debug) {
2303		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2304			apm_info.bios.cseg, apm_info.bios.offset,
2305			apm_info.bios.cseg_16, apm_info.bios.dseg);
2306		if (apm_info.bios.version > 0x100)
2307			printk(" cseg len %x, dseg len %x",
2308				apm_info.bios.cseg_len,
2309				apm_info.bios.dseg_len);
2310		if (apm_info.bios.version > 0x101)
2311			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2312		printk("\n");
2313	}
2314
2315	if (apm_info.disabled) {
2316		printk(KERN_NOTICE "apm: disabled on user request.\n");
2317		return -ENODEV;
2318	}
2319	if ((num_online_cpus() > 1) && !power_off && !smp) {
2320		printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2321		apm_info.disabled = 1;
2322		return -ENODEV;
2323	}
2324	if (!acpi_disabled) {
2325		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2326		apm_info.disabled = 1;
2327		return -ENODEV;
2328	}
2329
2330	/*
2331	 * Set up the long jump entry point to the APM BIOS, which is called
2332	 * from inline assembly.
2333	 */
2334	apm_bios_entry.offset = apm_info.bios.offset;
2335	apm_bios_entry.segment = APM_CS;
2336
2337	/*
2338	 * The APM 1.1 BIOS is supposed to provide limit information that it
2339	 * recognizes.  Many machines do this correctly, but many others do
2340	 * not restrict themselves to their claimed limit.  When this happens,
2341	 * they will cause a segmentation violation in the kernel at boot time.
2342	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2343	 *
2344	 * Note we only set APM segments on CPU zero, since we pin the APM
2345	 * code to that CPU.
2346	 */
2347	gdt = get_cpu_gdt_table(0);
2348	set_desc_base(&gdt[APM_CS >> 3],
2349		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2350	set_desc_base(&gdt[APM_CS_16 >> 3],
2351		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2352	set_desc_base(&gdt[APM_DS >> 3],
2353		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2354
2355	proc_create("apm", 0, NULL, &apm_file_ops);
2356
2357	kapmd_task = kthread_create(apm, NULL, "kapmd");
2358	if (IS_ERR(kapmd_task)) {
2359		printk(KERN_ERR "apm: disabled - Unable to start kernel "
2360				"thread.\n");
2361		err = PTR_ERR(kapmd_task);
2362		kapmd_task = NULL;
2363		remove_proc_entry("apm", NULL);
2364		return err;
2365	}
2366	wake_up_process(kapmd_task);
2367
2368	if (num_online_cpus() > 1 && !smp) {
2369		printk(KERN_NOTICE
2370		       "apm: disabled - APM is not SMP safe (power off active).\n");
2371		return 0;
2372	}
2373
2374	/*
2375	 * Note we don't actually care if the misc_device cannot be registered.
2376	 * this driver can do its job without it, even if userspace can't
2377	 * control it.  just log the error
2378	 */
2379	if (misc_register(&apm_device))
2380		printk(KERN_WARNING "apm: Could not register misc device.\n");
2381
2382	if (HZ != 100)
2383		idle_period = (idle_period * HZ) / 100;
2384	if (idle_threshold < 100) {
2385		original_pm_idle = pm_idle;
2386		pm_idle  = apm_cpu_idle;
2387		set_pm_idle = 1;
 
2388	}
2389
2390	return 0;
2391}
2392
2393static void __exit apm_exit(void)
2394{
2395	int error;
2396
2397	if (set_pm_idle) {
2398		pm_idle = original_pm_idle;
2399		/*
2400		 * We are about to unload the current idle thread pm callback
2401		 * (pm_idle), Wait for all processors to update cached/local
2402		 * copies of pm_idle before proceeding.
2403		 */
2404		kick_all_cpus_sync();
2405	}
2406	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2407	    && (apm_info.connection_version > 0x0100)) {
2408		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2409		if (error)
2410			apm_error("disengage power management", error);
2411	}
2412	misc_deregister(&apm_device);
2413	remove_proc_entry("apm", NULL);
2414	if (power_off)
2415		pm_power_off = NULL;
2416	if (kapmd_task) {
2417		kthread_stop(kapmd_task);
2418		kapmd_task = NULL;
2419	}
2420}
2421
2422module_init(apm_init);
2423module_exit(apm_exit);
2424
2425MODULE_AUTHOR("Stephen Rothwell");
2426MODULE_DESCRIPTION("Advanced Power Management");
2427MODULE_LICENSE("GPL");
2428module_param(debug, bool, 0644);
2429MODULE_PARM_DESC(debug, "Enable debug mode");
2430module_param(power_off, bool, 0444);
2431MODULE_PARM_DESC(power_off, "Enable power off");
2432module_param(bounce_interval, int, 0444);
2433MODULE_PARM_DESC(bounce_interval,
2434		"Set the number of ticks to ignore suspend bounces");
2435module_param(allow_ints, bool, 0444);
2436MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2437module_param(broken_psr, bool, 0444);
2438MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2439module_param(realmode_power_off, bool, 0444);
2440MODULE_PARM_DESC(realmode_power_off,
2441		"Switch to real mode before powering off");
2442module_param(idle_threshold, int, 0444);
2443MODULE_PARM_DESC(idle_threshold,
2444	"System idle percentage above which to make APM BIOS idle calls");
2445module_param(idle_period, int, 0444);
2446MODULE_PARM_DESC(idle_period,
2447	"Period (in sec/100) over which to caculate the idle percentage");
2448module_param(smp, bool, 0444);
2449MODULE_PARM_DESC(smp,
2450	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2451MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
v6.8
   1// SPDX-License-Identifier: GPL-2.0-or-later
   2/* -*- linux-c -*-
   3 * APM BIOS driver for Linux
   4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   5 *
   6 * Initial development of this driver was funded by NEC Australia P/L
   7 *	and NEC Corporation
   8 *
 
 
 
 
 
 
 
 
 
 
   9 * October 1995, Rik Faith (faith@cs.unc.edu):
  10 *    Minor enhancements and updates (to the patch set) for 1.3.x
  11 *    Documentation
  12 * January 1996, Rik Faith (faith@cs.unc.edu):
  13 *    Make /proc/apm easy to format (bump driver version)
  14 * March 1996, Rik Faith (faith@cs.unc.edu):
  15 *    Prohibit APM BIOS calls unless apm_enabled.
  16 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  18 *    Version 1.0 and 1.1
  19 * May 1996, Version 1.2
  20 * Feb 1998, Version 1.3
  21 * Feb 1998, Version 1.4
  22 * Aug 1998, Version 1.5
  23 * Sep 1998, Version 1.6
  24 * Nov 1998, Version 1.7
  25 * Jan 1999, Version 1.8
  26 * Jan 1999, Version 1.9
  27 * Oct 1999, Version 1.10
  28 * Nov 1999, Version 1.11
  29 * Jan 2000, Version 1.12
  30 * Feb 2000, Version 1.13
  31 * Nov 2000, Version 1.14
  32 * Oct 2001, Version 1.15
  33 * Jan 2002, Version 1.16
  34 * Oct 2002, Version 1.16ac
  35 *
  36 * History:
  37 *    0.6b: first version in official kernel, Linux 1.3.46
  38 *    0.7: changed /proc/apm format, Linux 1.3.58
  39 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  40 *    0.9: only call bios if bios is present, Linux 1.3.72
  41 *    1.0: use fixed device number, consolidate /proc/apm into this file,
  42 *         Linux 1.3.85
  43 *    1.1: support user-space standby and suspend, power off after system
  44 *         halted, Linux 1.3.98
  45 *    1.2: When resetting RTC after resume, take care so that the time
  46 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  47 *         <jtoth@princeton.edu>); improve interaction between
  48 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  49 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  50 *	   levels to the printk calls. APM is not defined for SMP machines.
  51 *         The new replacement for it is, but Linux doesn't yet support this.
  52 *         Alan Cox Linux 2.1.55
  53 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  54 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  55 *         Dean Gaudet <dgaudet@arctic.org>.
  56 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  57 *    1.5: Fix segment register reloading (in case of bad segments saved
  58 *         across BIOS call).
  59 *         Stephen Rothwell
  60 *    1.6: Cope with compiler/assembler differences.
  61 *         Only try to turn off the first display device.
  62 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  63 *                   <echter@informatik.uni-rostock.de>
  64 *         Stephen Rothwell
  65 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  66 *         to reflect current state of APM BIOS.
  67 *         Chris Rankin <rankinc@bellsouth.net>
  68 *         Reset interrupt 0 timer to 100Hz after suspend
  69 *         Chad Miller <cmiller@surfsouth.com>
  70 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  71 *         Richard Gooch <rgooch@atnf.csiro.au>
  72 *         Allow boot time disabling of APM
  73 *         Make boot messages far less verbose by default
  74 *         Make asm safer
  75 *         Stephen Rothwell
  76 *    1.8: Add CONFIG_APM_RTC_IS_GMT
  77 *         Richard Gooch <rgooch@atnf.csiro.au>
  78 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  79 *         remove dependency on CONFIG_PROC_FS
  80 *         Stephen Rothwell
  81 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  82 *         Try to cope with BIOS's that need to have all display
  83 *         devices blanked and not just the first one.
  84 *         Ross Paterson <ross@soi.city.ac.uk>
  85 *         Fix segment limit setting it has always been wrong as
  86 *         the segments needed to have byte granularity.
  87 *         Mark a few things __init.
  88 *         Add hack to allow power off of SMP systems by popular request.
  89 *         Use CONFIG_SMP instead of __SMP__
  90 *         Ignore BOUNCES for three seconds.
  91 *         Stephen Rothwell
  92 *   1.10: Fix for Thinkpad return code.
  93 *         Merge 2.2 and 2.3 drivers.
  94 *         Remove APM dependencies in arch/i386/kernel/process.c
  95 *         Remove APM dependencies in drivers/char/sysrq.c
  96 *         Reset time across standby.
  97 *         Allow more initialisation on SMP.
  98 *         Remove CONFIG_APM_POWER_OFF and make it boot time
  99 *         configurable (default on).
 100 *         Make debug only a boot time parameter (remove APM_DEBUG).
 101 *         Try to blank all devices on any error.
 102 *   1.11: Remove APM dependencies in drivers/char/console.c
 103 *         Check nr_running to detect if we are idle (from
 104 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 105 *         Fix for bioses that don't zero the top part of the
 106 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 107 *         (reported by Panos Katsaloulis <teras@writeme.com>).
 108 *         Real mode power off patch (Walter Hofmann
 109 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 110 *   1.12: Remove CONFIG_SMP as the compiler will optimize
 111 *         the code away anyway (smp_num_cpus == 1 in UP)
 112 *         noted by Artur Skawina <skawina@geocities.com>.
 113 *         Make power off under SMP work again.
 114 *         Fix thinko with initial engaging of BIOS.
 115 *         Make sure power off only happens on CPU 0
 116 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 117 *         Do error notification to user mode if BIOS calls fail.
 118 *         Move entrypoint offset fix to ...boot/setup.S
 119 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 120 *         Remove smp-power-off. SMP users must now specify
 121 *         "apm=power-off" on the kernel command line. Suggested
 122 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 123 *         <alan@lxorguk.ukuu.org.uk>.
 124 *         Register the /proc/apm entry even on SMP so that
 125 *         scripts that check for it before doing power off
 126 *         work (Jim Avera <jima@hal.com>).
 127 *   1.13: Changes for new pm_ interfaces (Andy Henroid
 128 *         <andy_henroid@yahoo.com>).
 129 *         Modularize the code.
 130 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 131 *         is now the way life works).
 132 *         Fix thinko in suspend() (wrong return).
 133 *         Notify drivers on critical suspend.
 134 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 135 *         modified by sfr).
 136 *         Disable interrupts while we are suspended (Andy Henroid
 137 *         <andy_henroid@yahoo.com> fixed by sfr).
 138 *         Make power off work on SMP again (Tony Hoyle
 139 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 140 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 141 *         interval is now configurable.
 142 *   1.14: Make connection version persist across module unload/load.
 143 *         Enable and engage power management earlier.
 144 *         Disengage power management on module unload.
 145 *         Changed to use the sysrq-register hack for registering the
 146 *         power off function called by magic sysrq based upon discussions
 147 *         in irc://irc.openprojects.net/#kernelnewbies
 148 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 149 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 150 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 151 *         Work around byte swap bug in one of the Vaio's BIOS's
 152 *         (Marc Boucher <marc@mbsi.ca>).
 153 *         Exposed the disable flag to dmi so that we can handle known
 154 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 155 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 156 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 157 *         If an APM idle fails log it and idle sensibly
 158 *   1.15: Don't queue events to clients who open the device O_WRONLY.
 159 *         Don't expect replies from clients who open the device O_RDONLY.
 160 *         (Idea from Thomas Hood)
 161 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 162 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 163 *         Notify listeners of standby or suspend events before notifying
 164 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 165 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 166 *         Ignore first resume after we generate our own resume event
 167 *         after a suspend (Thomas Hood)
 168 *         Daemonize now gets rid of our controlling terminal (sfr).
 169 *         CONFIG_APM_CPU_IDLE now just affects the default value of
 170 *         idle_threshold (sfr).
 171 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 172 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 173 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 174 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 175 *
 176 * APM 1.1 Reference:
 177 *
 178 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 179 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 180 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 181 *
 182 * [This document is available free from Intel by calling 800.628.8686 (fax
 183 * 916.356.6100) or 800.548.4725; or from
 184 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 185 * available from Microsoft by calling 206.882.8080.]
 186 *
 187 * APM 1.2 Reference:
 188 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 189 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 190 *
 191 * [This document is available from Microsoft at:
 192 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 193 */
 194
 195#define pr_fmt(fmt) "apm: " fmt
 196
 197#include <linux/module.h>
 198
 199#include <linux/poll.h>
 200#include <linux/types.h>
 201#include <linux/stddef.h>
 202#include <linux/timer.h>
 203#include <linux/fcntl.h>
 204#include <linux/slab.h>
 205#include <linux/stat.h>
 206#include <linux/proc_fs.h>
 207#include <linux/seq_file.h>
 208#include <linux/miscdevice.h>
 209#include <linux/apm_bios.h>
 210#include <linux/init.h>
 211#include <linux/time.h>
 212#include <linux/sched/signal.h>
 213#include <linux/sched/cputime.h>
 214#include <linux/pm.h>
 215#include <linux/capability.h>
 216#include <linux/device.h>
 217#include <linux/kernel.h>
 218#include <linux/freezer.h>
 219#include <linux/smp.h>
 220#include <linux/dmi.h>
 221#include <linux/suspend.h>
 222#include <linux/kthread.h>
 223#include <linux/jiffies.h>
 224#include <linux/acpi.h>
 225#include <linux/syscore_ops.h>
 226#include <linux/i8253.h>
 227#include <linux/cpuidle.h>
 228
 229#include <linux/uaccess.h>
 230#include <asm/desc.h>
 231#include <asm/olpc.h>
 232#include <asm/paravirt.h>
 233#include <asm/reboot.h>
 234#include <asm/nospec-branch.h>
 235#include <asm/ibt.h>
 236
 237#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 238extern int (*console_blank_hook)(int);
 239#endif
 240
 241/*
 
 
 
 
 
 
 242 * Various options can be changed at boot time as follows:
 243 * (We allow underscores for compatibility with the modules code)
 244 *	apm=on/off			enable/disable APM
 245 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
 246 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
 247 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
 248 *	    					powering off
 249 *	    [no-]debug			log some debugging messages
 250 *	    [no-]power[-_]off		power off on shutdown
 251 *	    [no-]smp			Use apm even on an SMP box
 252 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
 253 *	    				bounces
 254 *          idle[-_]threshold=<n>       System idle percentage above which to
 255 *                                      make APM BIOS idle calls. Set it to
 256 *                                      100 to disable.
 257 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 258 *                                      which the idle percentage is
 259 *                                      calculated.
 260 */
 261
 262/* KNOWN PROBLEM MACHINES:
 263 *
 264 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 265 *                         [Confirmed by TI representative]
 266 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 267 *                    [Confirmed by BIOS disassembly]
 268 *                    [This may work now ...]
 269 * P: Toshiba 1950S: battery life information only gets updated after resume
 270 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 271 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 272 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 273 * 	Neale Banks <neale@lowendale.com.au> December 2000
 274 *
 275 * Legend: U = unusable with APM patches
 276 *         P = partially usable with APM patches
 277 */
 278
 279/*
 280 * Define as 1 to make the driver always call the APM BIOS busy
 281 * routine even if the clock was not reported as slowed by the
 282 * idle routine.  Otherwise, define as 0.
 283 */
 284#define ALWAYS_CALL_BUSY   1
 285
 286/*
 287 * Define to make the APM BIOS calls zero all data segment registers (so
 288 * that an incorrect BIOS implementation will cause a kernel panic if it
 289 * tries to write to arbitrary memory).
 290 */
 291#define APM_ZERO_SEGS
 292
 293#include <asm/apm.h>
 294
 295/*
 296 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 297 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 298 * David Chen <chen@ctpa04.mit.edu>
 299 */
 300#undef INIT_TIMER_AFTER_SUSPEND
 301
 302#ifdef INIT_TIMER_AFTER_SUSPEND
 303#include <linux/timex.h>
 304#include <asm/io.h>
 305#include <linux/delay.h>
 306#endif
 307
 308/*
 309 * Need to poll the APM BIOS every second
 310 */
 311#define APM_CHECK_TIMEOUT	(HZ)
 312
 313/*
 314 * Ignore suspend events for this amount of time after a resume
 315 */
 316#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
 317
 318/*
 319 * Maximum number of events stored
 320 */
 321#define APM_MAX_EVENTS		20
 322
 323/*
 324 * The per-file APM data
 325 */
 326struct apm_user {
 327	int		magic;
 328	struct apm_user *next;
 329	unsigned int	suser: 1;
 330	unsigned int	writer: 1;
 331	unsigned int	reader: 1;
 332	unsigned int	suspend_wait: 1;
 333	int		suspend_result;
 334	int		suspends_pending;
 335	int		standbys_pending;
 336	int		suspends_read;
 337	int		standbys_read;
 338	int		event_head;
 339	int		event_tail;
 340	apm_event_t	events[APM_MAX_EVENTS];
 341};
 342
 343/*
 344 * The magic number in apm_user
 345 */
 346#define APM_BIOS_MAGIC		0x4101
 347
 348/*
 349 * idle percentage above which bios idle calls are done
 350 */
 351#ifdef CONFIG_APM_CPU_IDLE
 
 352#define DEFAULT_IDLE_THRESHOLD	95
 353#else
 354#define DEFAULT_IDLE_THRESHOLD	100
 355#endif
 356#define DEFAULT_IDLE_PERIOD	(100 / 3)
 357
 358static int apm_cpu_idle(struct cpuidle_device *dev,
 359			struct cpuidle_driver *drv, int index);
 360
 361static struct cpuidle_driver apm_idle_driver = {
 362	.name = "apm_idle",
 363	.owner = THIS_MODULE,
 364	.states = {
 365		{ /* entry 0 is for polling */ },
 366		{ /* entry 1 is for APM idle */
 367			.name = "APM",
 368			.desc = "APM idle",
 369			.exit_latency = 250,	/* WAG */
 370			.target_residency = 500,	/* WAG */
 371			.enter = &apm_cpu_idle
 372		},
 373	},
 374	.state_count = 2,
 375};
 376
 377static struct cpuidle_device apm_cpuidle_device;
 378
 379/*
 380 * Local variables
 381 */
 382__visible struct {
 383	unsigned long	offset;
 384	unsigned short	segment;
 385} apm_bios_entry;
 386static int clock_slowed;
 387static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 388static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 
 389static int suspends_pending;
 390static int standbys_pending;
 391static int ignore_sys_suspend;
 392static int ignore_normal_resume;
 393static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 394
 395static bool debug __read_mostly;
 396static bool smp __read_mostly;
 397static int apm_disabled = -1;
 398#ifdef CONFIG_SMP
 399static bool power_off;
 400#else
 401static bool power_off = 1;
 402#endif
 403static bool realmode_power_off;
 404#ifdef CONFIG_APM_ALLOW_INTS
 405static bool allow_ints = 1;
 406#else
 407static bool allow_ints;
 408#endif
 409static bool broken_psr;
 410
 411static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 412static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 413static struct apm_user *user_list;
 414static DEFINE_SPINLOCK(user_list_lock);
 415static DEFINE_MUTEX(apm_mutex);
 416
 417/*
 418 * Set up a segment that references the real mode segment 0x40
 419 * that extends up to the end of page zero (that we have reserved).
 420 * This is for buggy BIOS's that refer to (real mode) segment 0x40
 421 * even though they are called in protected mode.
 422 */
 423static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(DESC_DATA32_BIOS,
 424			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 425
 426static const char driver_version[] = "1.16ac";	/* no spaces */
 427
 428static struct task_struct *kapmd_task;
 429
 430/*
 431 *	APM event names taken from the APM 1.2 specification. These are
 432 *	the message codes that the BIOS uses to tell us about events
 433 */
 434static const char * const apm_event_name[] = {
 435	"system standby",
 436	"system suspend",
 437	"normal resume",
 438	"critical resume",
 439	"low battery",
 440	"power status change",
 441	"update time",
 442	"critical suspend",
 443	"user standby",
 444	"user suspend",
 445	"system standby resume",
 446	"capabilities change"
 447};
 448#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 449
 450typedef struct lookup_t {
 451	int	key;
 452	char 	*msg;
 453} lookup_t;
 454
 455/*
 456 *	The BIOS returns a set of standard error codes in AX when the
 457 *	carry flag is set.
 458 */
 459
 460static const lookup_t error_table[] = {
 461/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
 462	{ APM_DISABLED,		"Power management disabled" },
 463	{ APM_CONNECTED,	"Real mode interface already connected" },
 464	{ APM_NOT_CONNECTED,	"Interface not connected" },
 465	{ APM_16_CONNECTED,	"16 bit interface already connected" },
 466/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
 467	{ APM_32_CONNECTED,	"32 bit interface already connected" },
 468	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
 469	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
 470	{ APM_BAD_PARAM,	"Parameter out of range" },
 471	{ APM_NOT_ENGAGED,	"Interface not engaged" },
 472	{ APM_BAD_FUNCTION,     "Function not supported" },
 473	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
 474	{ APM_BAD_STATE,	"Unable to enter requested state" },
 475/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
 476	{ APM_NO_ERROR,		"BIOS did not set a return code" },
 477	{ APM_NOT_PRESENT,	"No APM present" }
 478};
 479#define ERROR_COUNT	ARRAY_SIZE(error_table)
 480
 481/**
 482 *	apm_error	-	display an APM error
 483 *	@str: information string
 484 *	@err: APM BIOS return code
 485 *
 486 *	Write a meaningful log entry to the kernel log in the event of
 487 *	an APM error.  Note that this also handles (negative) kernel errors.
 488 */
 489
 490static void apm_error(char *str, int err)
 491{
 492	int i;
 493
 494	for (i = 0; i < ERROR_COUNT; i++)
 495		if (error_table[i].key == err)
 496			break;
 497	if (i < ERROR_COUNT)
 498		pr_notice("%s: %s\n", str, error_table[i].msg);
 499	else if (err < 0)
 500		pr_notice("%s: linux error code %i\n", str, err);
 501	else
 502		pr_notice("%s: unknown error code %#2.2x\n",
 503		       str, err);
 504}
 505
 506/*
 507 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 508 * apm_info.allow_ints, we are being really paranoid here!  Not only
 509 * are interrupts disabled, but all the segment registers (except SS)
 510 * are saved and zeroed this means that if the BIOS tries to reference
 511 * any data without explicitly loading the segment registers, the kernel
 512 * will fault immediately rather than have some unforeseen circumstances
 513 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 514 * this depends on CS referring to the same physical memory as DS so that
 515 * DS can be zeroed before the call. Unfortunately, we can't do anything
 516 * about the stack segment/pointer.  Also, we tell the compiler that
 517 * everything could change.
 518 *
 519 * Also, we KNOW that for the non error case of apm_bios_call, there
 520 * is no useful data returned in the low order 8 bits of eax.
 521 */
 522
 523static inline unsigned long __apm_irq_save(void)
 524{
 525	unsigned long flags;
 526	local_save_flags(flags);
 527	if (apm_info.allow_ints) {
 528		if (irqs_disabled_flags(flags))
 529			local_irq_enable();
 530	} else
 531		local_irq_disable();
 532
 533	return flags;
 534}
 535
 536#define apm_irq_save(flags) \
 537	do { flags = __apm_irq_save(); } while (0)
 538
 539static inline void apm_irq_restore(unsigned long flags)
 540{
 541	if (irqs_disabled_flags(flags))
 542		local_irq_disable();
 543	else if (irqs_disabled())
 544		local_irq_enable();
 545}
 546
 547#ifdef APM_ZERO_SEGS
 548#	define APM_DECL_SEGS \
 549		unsigned int saved_fs; unsigned int saved_gs;
 550#	define APM_DO_SAVE_SEGS \
 551		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 552#	define APM_DO_RESTORE_SEGS \
 553		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 554#else
 555#	define APM_DECL_SEGS
 556#	define APM_DO_SAVE_SEGS
 557#	define APM_DO_RESTORE_SEGS
 558#endif
 559
 560struct apm_bios_call {
 561	u32 func;
 562	/* In and out */
 563	u32 ebx;
 564	u32 ecx;
 565	/* Out only */
 566	u32 eax;
 567	u32 edx;
 568	u32 esi;
 569
 570	/* Error: -ENOMEM, or bits 8-15 of eax */
 571	int err;
 572};
 573
 574/**
 575 *	__apm_bios_call - Make an APM BIOS 32bit call
 576 *	@_call: pointer to struct apm_bios_call.
 577 *
 578 *	Make an APM call using the 32bit protected mode interface. The
 579 *	caller is responsible for knowing if APM BIOS is configured and
 580 *	enabled. This call can disable interrupts for a long period of
 581 *	time on some laptops.  The return value is in AH and the carry
 582 *	flag is loaded into AL.  If there is an error, then the error
 583 *	code is returned in AH (bits 8-15 of eax) and this function
 584 *	returns non-zero.
 585 *
 586 *	Note: this makes the call on the current CPU.
 587 */
 588static long __apm_bios_call(void *_call)
 589{
 590	APM_DECL_SEGS
 591	unsigned long		flags;
 592	int			cpu;
 593	struct desc_struct	save_desc_40;
 594	struct desc_struct	*gdt;
 595	struct apm_bios_call	*call = _call;
 596	u64			ibt;
 597
 598	cpu = get_cpu();
 599	BUG_ON(cpu != 0);
 600	gdt = get_cpu_gdt_rw(cpu);
 601	save_desc_40 = gdt[0x40 / 8];
 602	gdt[0x40 / 8] = bad_bios_desc;
 603
 604	apm_irq_save(flags);
 605	firmware_restrict_branch_speculation_start();
 606	ibt = ibt_save(true);
 607	APM_DO_SAVE_SEGS;
 608	apm_bios_call_asm(call->func, call->ebx, call->ecx,
 609			  &call->eax, &call->ebx, &call->ecx, &call->edx,
 610			  &call->esi);
 611	APM_DO_RESTORE_SEGS;
 612	ibt_restore(ibt);
 613	firmware_restrict_branch_speculation_end();
 614	apm_irq_restore(flags);
 615	gdt[0x40 / 8] = save_desc_40;
 616	put_cpu();
 617
 618	return call->eax & 0xff;
 619}
 620
 621/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 622static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 623{
 624	int ret;
 625
 626	/* Don't bother with work_on_cpu in the common case, so we don't
 627	 * have to worry about OOM or overhead. */
 628	if (get_cpu() == 0) {
 629		ret = fn(call);
 630		put_cpu();
 631	} else {
 632		put_cpu();
 633		ret = work_on_cpu(0, fn, call);
 634	}
 635
 636	/* work_on_cpu can fail with -ENOMEM */
 637	if (ret < 0)
 638		call->err = ret;
 639	else
 640		call->err = (call->eax >> 8) & 0xff;
 641
 642	return ret;
 643}
 644
 645/**
 646 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
 647 *	@call: the apm_bios_call registers.
 648 *
 649 *	If there is an error, it is returned in @call.err.
 650 */
 651static int apm_bios_call(struct apm_bios_call *call)
 652{
 653	return on_cpu0(__apm_bios_call, call);
 654}
 655
 656/**
 657 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 658 *	@_call: pointer to struct apm_bios_call.
 659 *
 660 *	Make a BIOS call that returns one value only, or just status.
 661 *	If there is an error, then the error code is returned in AH
 662 *	(bits 8-15 of eax) and this function returns non-zero (it can
 663 *	also return -ENOMEM). This is used for simpler BIOS operations.
 664 *	This call may hold interrupts off for a long time on some laptops.
 665 *
 666 *	Note: this makes the call on the current CPU.
 667 */
 668static long __apm_bios_call_simple(void *_call)
 669{
 670	u8			error;
 671	APM_DECL_SEGS
 672	unsigned long		flags;
 673	int			cpu;
 674	struct desc_struct	save_desc_40;
 675	struct desc_struct	*gdt;
 676	struct apm_bios_call	*call = _call;
 677	u64			ibt;
 678
 679	cpu = get_cpu();
 680	BUG_ON(cpu != 0);
 681	gdt = get_cpu_gdt_rw(cpu);
 682	save_desc_40 = gdt[0x40 / 8];
 683	gdt[0x40 / 8] = bad_bios_desc;
 684
 685	apm_irq_save(flags);
 686	firmware_restrict_branch_speculation_start();
 687	ibt = ibt_save(true);
 688	APM_DO_SAVE_SEGS;
 689	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 690					 &call->eax);
 691	APM_DO_RESTORE_SEGS;
 692	ibt_restore(ibt);
 693	firmware_restrict_branch_speculation_end();
 694	apm_irq_restore(flags);
 695	gdt[0x40 / 8] = save_desc_40;
 696	put_cpu();
 697	return error;
 698}
 699
 700/**
 701 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
 702 *	@func: APM function to invoke
 703 *	@ebx_in: EBX register value for BIOS call
 704 *	@ecx_in: ECX register value for BIOS call
 705 *	@eax: EAX register on return from the BIOS call
 706 *	@err: bits
 707 *
 708 *	Make a BIOS call that returns one value only, or just status.
 709 *	If there is an error, then the error code is returned in @err
 710 *	and this function returns non-zero. This is used for simpler
 711 *	BIOS operations.  This call may hold interrupts off for a long
 712 *	time on some laptops.
 713 */
 714static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 715				int *err)
 716{
 717	struct apm_bios_call call;
 718	int ret;
 719
 720	call.func = func;
 721	call.ebx = ebx_in;
 722	call.ecx = ecx_in;
 723
 724	ret = on_cpu0(__apm_bios_call_simple, &call);
 725	*eax = call.eax;
 726	*err = call.err;
 727	return ret;
 728}
 729
 730/**
 731 *	apm_driver_version	-	APM driver version
 732 *	@val:	loaded with the APM version on return
 733 *
 734 *	Retrieve the APM version supported by the BIOS. This is only
 735 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
 736 *	probably present.
 737 *
 738 *	On entry val should point to a value indicating the APM driver
 739 *	version with the high byte being the major and the low byte the
 740 *	minor number both in BCD
 741 *
 742 *	On return it will hold the BIOS revision supported in the
 743 *	same format.
 744 */
 745
 746static int apm_driver_version(u_short *val)
 747{
 748	u32 eax;
 749	int err;
 750
 751	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 752		return err;
 753	*val = eax;
 754	return APM_SUCCESS;
 755}
 756
 757/**
 758 *	apm_get_event	-	get an APM event from the BIOS
 759 *	@event: pointer to the event
 760 *	@info: point to the event information
 761 *
 762 *	The APM BIOS provides a polled information for event
 763 *	reporting. The BIOS expects to be polled at least every second
 764 *	when events are pending. When a message is found the caller should
 765 *	poll until no more messages are present.  However, this causes
 766 *	problems on some laptops where a suspend event notification is
 767 *	not cleared until it is acknowledged.
 768 *
 769 *	Additional information is returned in the info pointer, providing
 770 *	that APM 1.2 is in use. If no messages are pending the value 0x80
 771 *	is returned (No power management events pending).
 772 */
 773static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 774{
 775	struct apm_bios_call call;
 776
 777	call.func = APM_FUNC_GET_EVENT;
 778	call.ebx = call.ecx = 0;
 779
 780	if (apm_bios_call(&call))
 781		return call.err;
 782
 783	*event = call.ebx;
 784	if (apm_info.connection_version < 0x0102)
 785		*info = ~0; /* indicate info not valid */
 786	else
 787		*info = call.ecx;
 788	return APM_SUCCESS;
 789}
 790
 791/**
 792 *	set_power_state	-	set the power management state
 793 *	@what: which items to transition
 794 *	@state: state to transition to
 795 *
 796 *	Request an APM change of state for one or more system devices. The
 797 *	processor state must be transitioned last of all. what holds the
 798 *	class of device in the upper byte and the device number (0xFF for
 799 *	all) for the object to be transitioned.
 800 *
 801 *	The state holds the state to transition to, which may in fact
 802 *	be an acceptance of a BIOS requested state change.
 803 */
 804
 805static int set_power_state(u_short what, u_short state)
 806{
 807	u32 eax;
 808	int err;
 809
 810	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 811		return err;
 812	return APM_SUCCESS;
 813}
 814
 815/**
 816 *	set_system_power_state - set system wide power state
 817 *	@state: which state to enter
 818 *
 819 *	Transition the entire system into a new APM power state.
 820 */
 821
 822static int set_system_power_state(u_short state)
 823{
 824	return set_power_state(APM_DEVICE_ALL, state);
 825}
 826
 827/**
 828 *	apm_do_idle	-	perform power saving
 829 *
 830 *	This function notifies the BIOS that the processor is (in the view
 831 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
 832 *	to handle the idle request. On a success the function returns 1
 833 *	if the BIOS did clock slowing or 0 otherwise.
 834 */
 835
 836static int apm_do_idle(void)
 837{
 838	u32 eax;
 839	u8 ret = 0;
 840	int idled = 0;
 
 841	int err = 0;
 842
 
 
 
 
 
 
 
 
 
 843	if (!need_resched()) {
 844		idled = 1;
 845		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 846	}
 
 
 847
 848	if (!idled)
 849		return 0;
 850
 851	if (ret) {
 852		static unsigned long t;
 853
 854		/* This always fails on some SMP boards running UP kernels.
 855		 * Only report the failure the first 5 times.
 856		 */
 857		if (++t < 5) {
 858			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 859			t = jiffies;
 860		}
 861		return -1;
 862	}
 863	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 864	return clock_slowed;
 865}
 866
 867/**
 868 *	apm_do_busy	-	inform the BIOS the CPU is busy
 869 *
 870 *	Request that the BIOS brings the CPU back to full performance.
 871 */
 872
 873static void apm_do_busy(void)
 874{
 875	u32 dummy;
 876	int err;
 877
 878	if (clock_slowed || ALWAYS_CALL_BUSY) {
 879		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 880		clock_slowed = 0;
 881	}
 882}
 883
 884/*
 885 * If no process has really been interested in
 886 * the CPU for some time, we want to call BIOS
 887 * power management - we probably want
 888 * to conserve power.
 889 */
 890#define IDLE_CALC_LIMIT	(HZ * 100)
 891#define IDLE_LEAKY_MAX	16
 892
 
 
 893/**
 894 * apm_cpu_idle		-	cpu idling for APM capable Linux
 895 *
 896 * This is the idling function the kernel executes when APM is available. It
 897 * tries to do BIOS powermanagement based on the average system idle time.
 898 * Furthermore it calls the system default idle routine.
 899 */
 900
 901static int apm_cpu_idle(struct cpuidle_device *dev,
 902	struct cpuidle_driver *drv, int index)
 903{
 904	static int use_apm_idle; /* = 0 */
 905	static unsigned int last_jiffies; /* = 0 */
 906	static u64 last_stime; /* = 0 */
 907	u64 stime, utime;
 908
 909	int apm_idle_done = 0;
 910	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 911	unsigned int bucket;
 912
 
 913recalc:
 914	task_cputime(current, &utime, &stime);
 915	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 916		use_apm_idle = 0;
 
 
 917	} else if (jiffies_since_last_check > idle_period) {
 918		unsigned int idle_percentage;
 919
 920		idle_percentage = nsecs_to_jiffies(stime - last_stime);
 921		idle_percentage *= 100;
 922		idle_percentage /= jiffies_since_last_check;
 923		use_apm_idle = (idle_percentage > idle_threshold);
 924		if (apm_info.forbid_idle)
 925			use_apm_idle = 0;
 
 
 926	}
 927
 928	last_jiffies = jiffies;
 929	last_stime = stime;
 930
 931	bucket = IDLE_LEAKY_MAX;
 932
 933	while (!need_resched()) {
 934		if (use_apm_idle) {
 935			unsigned int t;
 936
 937			t = jiffies;
 938			switch (apm_do_idle()) {
 939			case 0:
 940				apm_idle_done = 1;
 941				if (t != jiffies) {
 942					if (bucket) {
 943						bucket = IDLE_LEAKY_MAX;
 944						continue;
 945					}
 946				} else if (bucket) {
 947					bucket--;
 948					continue;
 949				}
 950				break;
 951			case 1:
 952				apm_idle_done = 1;
 953				break;
 954			default: /* BIOS refused */
 955				break;
 956			}
 957		}
 958		default_idle();
 
 
 
 959		local_irq_disable();
 960		jiffies_since_last_check = jiffies - last_jiffies;
 961		if (jiffies_since_last_check > idle_period)
 962			goto recalc;
 963	}
 964
 965	if (apm_idle_done)
 966		apm_do_busy();
 967
 968	return index;
 969}
 970
 971/**
 972 *	apm_power_off	-	ask the BIOS to power off
 973 *
 974 *	Handle the power off sequence. This is the one piece of code we
 975 *	will execute even on SMP machines. In order to deal with BIOS
 976 *	bugs we support real mode APM BIOS power off calls. We also make
 977 *	the SMP call on CPU0 as some systems will only honour this call
 978 *	on their first cpu.
 979 */
 980
 981static void apm_power_off(void)
 982{
 983	/* Some bioses don't like being called from CPU != 0 */
 984	if (apm_info.realmode_power_off) {
 985		set_cpus_allowed_ptr(current, cpumask_of(0));
 986		machine_real_restart(MRR_APM);
 987	} else {
 988		(void)set_system_power_state(APM_STATE_OFF);
 989	}
 990}
 991
 992#ifdef CONFIG_APM_DO_ENABLE
 993
 994/**
 995 *	apm_enable_power_management - enable BIOS APM power management
 996 *	@enable: enable yes/no
 997 *
 998 *	Enable or disable the APM BIOS power services.
 999 */
1000
1001static int apm_enable_power_management(int enable)
1002{
1003	u32 eax;
1004	int err;
1005
1006	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1007		return APM_NOT_ENGAGED;
1008	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1009				 enable, &eax, &err))
1010		return err;
1011	if (enable)
1012		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1013	else
1014		apm_info.bios.flags |= APM_BIOS_DISABLED;
1015	return APM_SUCCESS;
1016}
1017#endif
1018
1019/**
1020 *	apm_get_power_status	-	get current power state
1021 *	@status: returned status
1022 *	@bat: battery info
1023 *	@life: estimated life
1024 *
1025 *	Obtain the current power status from the APM BIOS. We return a
1026 *	status which gives the rough battery status, and current power
1027 *	source. The bat value returned give an estimate as a percentage
1028 *	of life and a status value for the battery. The estimated life
1029 *	if reported is a lifetime in seconds/minutes at current power
1030 *	consumption.
1031 */
1032
1033static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1034{
1035	struct apm_bios_call call;
1036
1037	call.func = APM_FUNC_GET_STATUS;
1038	call.ebx = APM_DEVICE_ALL;
1039	call.ecx = 0;
1040
1041	if (apm_info.get_power_status_broken)
1042		return APM_32_UNSUPPORTED;
1043	if (apm_bios_call(&call)) {
1044		if (!call.err)
1045			return APM_NO_ERROR;
1046		return call.err;
1047	}
1048	*status = call.ebx;
1049	*bat = call.ecx;
1050	if (apm_info.get_power_status_swabinminutes) {
1051		*life = swab16((u16)call.edx);
1052		*life |= 0x8000;
1053	} else
1054		*life = call.edx;
1055	return APM_SUCCESS;
1056}
1057
1058#if 0
1059static int apm_get_battery_status(u_short which, u_short *status,
1060				  u_short *bat, u_short *life, u_short *nbat)
1061{
1062	u32 eax;
1063	u32 ebx;
1064	u32 ecx;
1065	u32 edx;
1066	u32 esi;
1067
1068	if (apm_info.connection_version < 0x0102) {
1069		/* pretend we only have one battery. */
1070		if (which != 1)
1071			return APM_BAD_DEVICE;
1072		*nbat = 1;
1073		return apm_get_power_status(status, bat, life);
1074	}
1075
1076	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1077			  &ebx, &ecx, &edx, &esi))
1078		return (eax >> 8) & 0xff;
1079	*status = ebx;
1080	*bat = ecx;
1081	*life = edx;
1082	*nbat = esi;
1083	return APM_SUCCESS;
1084}
1085#endif
1086
1087/**
1088 *	apm_engage_power_management	-	enable PM on a device
1089 *	@device: identity of device
1090 *	@enable: on/off
1091 *
1092 *	Activate or deactivate power management on either a specific device
1093 *	or the entire system (%APM_DEVICE_ALL).
1094 */
1095
1096static int apm_engage_power_management(u_short device, int enable)
1097{
1098	u32 eax;
1099	int err;
1100
1101	if ((enable == 0) && (device == APM_DEVICE_ALL)
1102	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1103		return APM_DISABLED;
1104	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1105				 &eax, &err))
1106		return err;
1107	if (device == APM_DEVICE_ALL) {
1108		if (enable)
1109			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1110		else
1111			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1112	}
1113	return APM_SUCCESS;
1114}
1115
1116#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1117
1118/**
1119 *	apm_console_blank	-	blank the display
1120 *	@blank: on/off
1121 *
1122 *	Attempt to blank the console, firstly by blanking just video device
1123 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1124 *	all video devices. Typically the BIOS will do laptop backlight and
1125 *	monitor powerdown for us.
1126 */
1127
1128static int apm_console_blank(int blank)
1129{
1130	int error = APM_NOT_ENGAGED; /* silence gcc */
1131	int i;
1132	u_short state;
1133	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1134
1135	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1136
1137	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1138		error = set_power_state(dev[i], state);
1139
1140		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1141			return 1;
1142
1143		if (error == APM_NOT_ENGAGED)
1144			break;
1145	}
1146
1147	if (error == APM_NOT_ENGAGED) {
1148		static int tried;
1149		int eng_error;
1150		if (tried++ == 0) {
1151			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1152			if (eng_error) {
1153				apm_error("set display", error);
1154				apm_error("engage interface", eng_error);
1155				return 0;
1156			} else
1157				return apm_console_blank(blank);
1158		}
1159	}
1160	apm_error("set display", error);
1161	return 0;
1162}
1163#endif
1164
1165static int queue_empty(struct apm_user *as)
1166{
1167	return as->event_head == as->event_tail;
1168}
1169
1170static apm_event_t get_queued_event(struct apm_user *as)
1171{
1172	if (++as->event_tail >= APM_MAX_EVENTS)
1173		as->event_tail = 0;
1174	return as->events[as->event_tail];
1175}
1176
1177static void queue_event(apm_event_t event, struct apm_user *sender)
1178{
1179	struct apm_user *as;
1180
1181	spin_lock(&user_list_lock);
1182	if (user_list == NULL)
1183		goto out;
1184	for (as = user_list; as != NULL; as = as->next) {
1185		if ((as == sender) || (!as->reader))
1186			continue;
1187		if (++as->event_head >= APM_MAX_EVENTS)
1188			as->event_head = 0;
1189
1190		if (as->event_head == as->event_tail) {
1191			static int notified;
1192
1193			if (notified++ == 0)
1194				pr_err("an event queue overflowed\n");
1195			if (++as->event_tail >= APM_MAX_EVENTS)
1196				as->event_tail = 0;
1197		}
1198		as->events[as->event_head] = event;
1199		if (!as->suser || !as->writer)
1200			continue;
1201		switch (event) {
1202		case APM_SYS_SUSPEND:
1203		case APM_USER_SUSPEND:
1204			as->suspends_pending++;
1205			suspends_pending++;
1206			break;
1207
1208		case APM_SYS_STANDBY:
1209		case APM_USER_STANDBY:
1210			as->standbys_pending++;
1211			standbys_pending++;
1212			break;
1213		}
1214	}
1215	wake_up_interruptible(&apm_waitqueue);
1216out:
1217	spin_unlock(&user_list_lock);
1218}
1219
1220static void reinit_timer(void)
1221{
1222#ifdef INIT_TIMER_AFTER_SUSPEND
1223	unsigned long flags;
1224
1225	raw_spin_lock_irqsave(&i8253_lock, flags);
1226	/* set the clock to HZ */
1227	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1228	udelay(10);
1229	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1230	udelay(10);
1231	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1232	udelay(10);
1233	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1234#endif
1235}
1236
1237static int suspend(int vetoable)
1238{
1239	int err;
1240	struct apm_user	*as;
1241
1242	dpm_suspend_start(PMSG_SUSPEND);
1243	dpm_suspend_end(PMSG_SUSPEND);
1244
1245	local_irq_disable();
1246	syscore_suspend();
1247
1248	local_irq_enable();
1249
1250	save_processor_state();
1251	err = set_system_power_state(APM_STATE_SUSPEND);
1252	ignore_normal_resume = 1;
1253	restore_processor_state();
1254
1255	local_irq_disable();
1256	reinit_timer();
1257
1258	if (err == APM_NO_ERROR)
1259		err = APM_SUCCESS;
1260	if (err != APM_SUCCESS)
1261		apm_error("suspend", err);
1262	err = (err == APM_SUCCESS) ? 0 : -EIO;
1263
1264	syscore_resume();
1265	local_irq_enable();
1266
1267	dpm_resume_start(PMSG_RESUME);
1268	dpm_resume_end(PMSG_RESUME);
1269
1270	queue_event(APM_NORMAL_RESUME, NULL);
1271	spin_lock(&user_list_lock);
1272	for (as = user_list; as != NULL; as = as->next) {
1273		as->suspend_wait = 0;
1274		as->suspend_result = err;
1275	}
1276	spin_unlock(&user_list_lock);
1277	wake_up_interruptible(&apm_suspend_waitqueue);
1278	return err;
1279}
1280
1281static void standby(void)
1282{
1283	int err;
1284
1285	dpm_suspend_end(PMSG_SUSPEND);
1286
1287	local_irq_disable();
1288	syscore_suspend();
1289	local_irq_enable();
1290
1291	err = set_system_power_state(APM_STATE_STANDBY);
1292	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1293		apm_error("standby", err);
1294
1295	local_irq_disable();
1296	syscore_resume();
1297	local_irq_enable();
1298
1299	dpm_resume_start(PMSG_RESUME);
1300}
1301
1302static apm_event_t get_event(void)
1303{
1304	int error;
1305	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1306	apm_eventinfo_t	info;
1307
1308	static int notified;
1309
1310	/* we don't use the eventinfo */
1311	error = apm_get_event(&event, &info);
1312	if (error == APM_SUCCESS)
1313		return event;
1314
1315	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1316		apm_error("get_event", error);
1317
1318	return 0;
1319}
1320
1321static void check_events(void)
1322{
1323	apm_event_t event;
1324	static unsigned long last_resume;
1325	static int ignore_bounce;
1326
1327	while ((event = get_event()) != 0) {
1328		if (debug) {
1329			if (event <= NR_APM_EVENT_NAME)
1330				printk(KERN_DEBUG "apm: received %s notify\n",
1331				       apm_event_name[event - 1]);
1332			else
1333				printk(KERN_DEBUG "apm: received unknown "
1334				       "event 0x%02x\n", event);
1335		}
1336		if (ignore_bounce
1337		    && (time_after(jiffies, last_resume + bounce_interval)))
1338			ignore_bounce = 0;
1339
1340		switch (event) {
1341		case APM_SYS_STANDBY:
1342		case APM_USER_STANDBY:
1343			queue_event(event, NULL);
1344			if (standbys_pending <= 0)
1345				standby();
1346			break;
1347
1348		case APM_USER_SUSPEND:
1349#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1350			if (apm_info.connection_version > 0x100)
1351				set_system_power_state(APM_STATE_REJECT);
1352			break;
1353#endif
1354		case APM_SYS_SUSPEND:
1355			if (ignore_bounce) {
1356				if (apm_info.connection_version > 0x100)
1357					set_system_power_state(APM_STATE_REJECT);
1358				break;
1359			}
1360			/*
1361			 * If we are already processing a SUSPEND,
1362			 * then further SUSPEND events from the BIOS
1363			 * will be ignored.  We also return here to
1364			 * cope with the fact that the Thinkpads keep
1365			 * sending a SUSPEND event until something else
1366			 * happens!
1367			 */
1368			if (ignore_sys_suspend)
1369				return;
1370			ignore_sys_suspend = 1;
1371			queue_event(event, NULL);
1372			if (suspends_pending <= 0)
1373				(void) suspend(1);
1374			break;
1375
1376		case APM_NORMAL_RESUME:
1377		case APM_CRITICAL_RESUME:
1378		case APM_STANDBY_RESUME:
1379			ignore_sys_suspend = 0;
1380			last_resume = jiffies;
1381			ignore_bounce = 1;
1382			if ((event != APM_NORMAL_RESUME)
1383			    || (ignore_normal_resume == 0)) {
1384				dpm_resume_end(PMSG_RESUME);
1385				queue_event(event, NULL);
1386			}
1387			ignore_normal_resume = 0;
1388			break;
1389
1390		case APM_CAPABILITY_CHANGE:
1391		case APM_LOW_BATTERY:
1392		case APM_POWER_STATUS_CHANGE:
1393			queue_event(event, NULL);
1394			/* If needed, notify drivers here */
1395			break;
1396
1397		case APM_UPDATE_TIME:
1398			break;
1399
1400		case APM_CRITICAL_SUSPEND:
1401			/*
1402			 * We are not allowed to reject a critical suspend.
1403			 */
1404			(void)suspend(0);
1405			break;
1406		}
1407	}
1408}
1409
1410static void apm_event_handler(void)
1411{
1412	static int pending_count = 4;
1413	int err;
1414
1415	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1416		if ((apm_info.connection_version > 0x100) &&
1417		    (pending_count-- <= 0)) {
1418			pending_count = 4;
1419			if (debug)
1420				printk(KERN_DEBUG "apm: setting state busy\n");
1421			err = set_system_power_state(APM_STATE_BUSY);
1422			if (err)
1423				apm_error("busy", err);
1424		}
1425	} else
1426		pending_count = 4;
1427	check_events();
1428}
1429
1430/*
1431 * This is the APM thread main loop.
1432 */
1433
1434static void apm_mainloop(void)
1435{
1436	DECLARE_WAITQUEUE(wait, current);
1437
1438	add_wait_queue(&apm_waitqueue, &wait);
1439	set_current_state(TASK_INTERRUPTIBLE);
1440	for (;;) {
1441		schedule_timeout(APM_CHECK_TIMEOUT);
1442		if (kthread_should_stop())
1443			break;
1444		/*
1445		 * Ok, check all events, check for idle (and mark us sleeping
1446		 * so as not to count towards the load average)..
1447		 */
1448		set_current_state(TASK_INTERRUPTIBLE);
1449		apm_event_handler();
1450	}
1451	remove_wait_queue(&apm_waitqueue, &wait);
1452}
1453
1454static int check_apm_user(struct apm_user *as, const char *func)
1455{
1456	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1457		pr_err("%s passed bad filp\n", func);
1458		return 1;
1459	}
1460	return 0;
1461}
1462
1463static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1464{
1465	struct apm_user *as;
1466	int i;
1467	apm_event_t event;
1468
1469	as = fp->private_data;
1470	if (check_apm_user(as, "read"))
1471		return -EIO;
1472	if ((int)count < sizeof(apm_event_t))
1473		return -EINVAL;
1474	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1475		return -EAGAIN;
1476	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1477	i = count;
1478	while ((i >= sizeof(event)) && !queue_empty(as)) {
1479		event = get_queued_event(as);
1480		if (copy_to_user(buf, &event, sizeof(event))) {
1481			if (i < count)
1482				break;
1483			return -EFAULT;
1484		}
1485		switch (event) {
1486		case APM_SYS_SUSPEND:
1487		case APM_USER_SUSPEND:
1488			as->suspends_read++;
1489			break;
1490
1491		case APM_SYS_STANDBY:
1492		case APM_USER_STANDBY:
1493			as->standbys_read++;
1494			break;
1495		}
1496		buf += sizeof(event);
1497		i -= sizeof(event);
1498	}
1499	if (i < count)
1500		return count - i;
1501	if (signal_pending(current))
1502		return -ERESTARTSYS;
1503	return 0;
1504}
1505
1506static __poll_t do_poll(struct file *fp, poll_table *wait)
1507{
1508	struct apm_user *as;
1509
1510	as = fp->private_data;
1511	if (check_apm_user(as, "poll"))
1512		return 0;
1513	poll_wait(fp, &apm_waitqueue, wait);
1514	if (!queue_empty(as))
1515		return EPOLLIN | EPOLLRDNORM;
1516	return 0;
1517}
1518
1519static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1520{
1521	struct apm_user *as;
1522	int ret;
1523
1524	as = filp->private_data;
1525	if (check_apm_user(as, "ioctl"))
1526		return -EIO;
1527	if (!as->suser || !as->writer)
1528		return -EPERM;
1529	switch (cmd) {
1530	case APM_IOC_STANDBY:
1531		mutex_lock(&apm_mutex);
1532		if (as->standbys_read > 0) {
1533			as->standbys_read--;
1534			as->standbys_pending--;
1535			standbys_pending--;
1536		} else
1537			queue_event(APM_USER_STANDBY, as);
1538		if (standbys_pending <= 0)
1539			standby();
1540		mutex_unlock(&apm_mutex);
1541		break;
1542	case APM_IOC_SUSPEND:
1543		mutex_lock(&apm_mutex);
1544		if (as->suspends_read > 0) {
1545			as->suspends_read--;
1546			as->suspends_pending--;
1547			suspends_pending--;
1548		} else
1549			queue_event(APM_USER_SUSPEND, as);
1550		if (suspends_pending <= 0) {
1551			ret = suspend(1);
1552			mutex_unlock(&apm_mutex);
1553		} else {
1554			as->suspend_wait = 1;
1555			mutex_unlock(&apm_mutex);
1556			wait_event_interruptible(apm_suspend_waitqueue,
1557					as->suspend_wait == 0);
1558			ret = as->suspend_result;
1559		}
1560		return ret;
1561	default:
1562		return -ENOTTY;
1563	}
1564	return 0;
1565}
1566
1567static int do_release(struct inode *inode, struct file *filp)
1568{
1569	struct apm_user *as;
1570
1571	as = filp->private_data;
1572	if (check_apm_user(as, "release"))
1573		return 0;
1574	filp->private_data = NULL;
1575	if (as->standbys_pending > 0) {
1576		standbys_pending -= as->standbys_pending;
1577		if (standbys_pending <= 0)
1578			standby();
1579	}
1580	if (as->suspends_pending > 0) {
1581		suspends_pending -= as->suspends_pending;
1582		if (suspends_pending <= 0)
1583			(void) suspend(1);
1584	}
1585	spin_lock(&user_list_lock);
1586	if (user_list == as)
1587		user_list = as->next;
1588	else {
1589		struct apm_user *as1;
1590
1591		for (as1 = user_list;
1592		     (as1 != NULL) && (as1->next != as);
1593		     as1 = as1->next)
1594			;
1595		if (as1 == NULL)
1596			pr_err("filp not in user list\n");
1597		else
1598			as1->next = as->next;
1599	}
1600	spin_unlock(&user_list_lock);
1601	kfree(as);
1602	return 0;
1603}
1604
1605static int do_open(struct inode *inode, struct file *filp)
1606{
1607	struct apm_user *as;
1608
1609	as = kmalloc(sizeof(*as), GFP_KERNEL);
1610	if (as == NULL)
 
 
1611		return -ENOMEM;
1612
1613	as->magic = APM_BIOS_MAGIC;
1614	as->event_tail = as->event_head = 0;
1615	as->suspends_pending = as->standbys_pending = 0;
1616	as->suspends_read = as->standbys_read = 0;
1617	/*
1618	 * XXX - this is a tiny bit broken, when we consider BSD
1619	 * process accounting. If the device is opened by root, we
1620	 * instantly flag that we used superuser privs. Who knows,
1621	 * we might close the device immediately without doing a
1622	 * privileged operation -- cevans
1623	 */
1624	as->suser = capable(CAP_SYS_ADMIN);
1625	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1626	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1627	spin_lock(&user_list_lock);
1628	as->next = user_list;
1629	user_list = as;
1630	spin_unlock(&user_list_lock);
1631	filp->private_data = as;
1632	return 0;
1633}
1634
1635#ifdef CONFIG_PROC_FS
1636static int proc_apm_show(struct seq_file *m, void *v)
1637{
1638	unsigned short	bx;
1639	unsigned short	cx;
1640	unsigned short	dx;
1641	int		error;
1642	unsigned short  ac_line_status = 0xff;
1643	unsigned short  battery_status = 0xff;
1644	unsigned short  battery_flag   = 0xff;
1645	int		percentage     = -1;
1646	int             time_units     = -1;
1647	char            *units         = "?";
1648
1649	if ((num_online_cpus() == 1) &&
1650	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1651		ac_line_status = (bx >> 8) & 0xff;
1652		battery_status = bx & 0xff;
1653		if ((cx & 0xff) != 0xff)
1654			percentage = cx & 0xff;
1655
1656		if (apm_info.connection_version > 0x100) {
1657			battery_flag = (cx >> 8) & 0xff;
1658			if (dx != 0xffff) {
1659				units = (dx & 0x8000) ? "min" : "sec";
1660				time_units = dx & 0x7fff;
1661			}
1662		}
1663	}
1664	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1665	   from the Get Power Status (0x0a) call unless otherwise noted.
1666
1667	   0) Linux driver version (this will change if format changes)
1668	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1669	   2) APM flags from APM Installation Check (0x00):
1670	      bit 0: APM_16_BIT_SUPPORT
1671	      bit 1: APM_32_BIT_SUPPORT
1672	      bit 2: APM_IDLE_SLOWS_CLOCK
1673	      bit 3: APM_BIOS_DISABLED
1674	      bit 4: APM_BIOS_DISENGAGED
1675	   3) AC line status
1676	      0x00: Off-line
1677	      0x01: On-line
1678	      0x02: On backup power (BIOS >= 1.1 only)
1679	      0xff: Unknown
1680	   4) Battery status
1681	      0x00: High
1682	      0x01: Low
1683	      0x02: Critical
1684	      0x03: Charging
1685	      0x04: Selected battery not present (BIOS >= 1.2 only)
1686	      0xff: Unknown
1687	   5) Battery flag
1688	      bit 0: High
1689	      bit 1: Low
1690	      bit 2: Critical
1691	      bit 3: Charging
1692	      bit 7: No system battery
1693	      0xff: Unknown
1694	   6) Remaining battery life (percentage of charge):
1695	      0-100: valid
1696	      -1: Unknown
1697	   7) Remaining battery life (time units):
1698	      Number of remaining minutes or seconds
1699	      -1: Unknown
1700	   8) min = minutes; sec = seconds */
1701
1702	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1703		   driver_version,
1704		   (apm_info.bios.version >> 8) & 0xff,
1705		   apm_info.bios.version & 0xff,
1706		   apm_info.bios.flags,
1707		   ac_line_status,
1708		   battery_status,
1709		   battery_flag,
1710		   percentage,
1711		   time_units,
1712		   units);
1713	return 0;
1714}
1715#endif
 
 
 
 
 
 
 
 
 
 
 
 
1716
1717static int apm(void *unused)
1718{
1719	unsigned short	bx;
1720	unsigned short	cx;
1721	unsigned short	dx;
1722	int		error;
1723	char 		*power_stat;
1724	char 		*bat_stat;
1725
1726	/* 2002/08/01 - WT
1727	 * This is to avoid random crashes at boot time during initialization
1728	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1729	 * Some bioses don't like being called from CPU != 0.
1730	 * Method suggested by Ingo Molnar.
1731	 */
1732	set_cpus_allowed_ptr(current, cpumask_of(0));
1733	BUG_ON(smp_processor_id() != 0);
1734
1735	if (apm_info.connection_version == 0) {
1736		apm_info.connection_version = apm_info.bios.version;
1737		if (apm_info.connection_version > 0x100) {
1738			/*
1739			 * We only support BIOSs up to version 1.2
1740			 */
1741			if (apm_info.connection_version > 0x0102)
1742				apm_info.connection_version = 0x0102;
1743			error = apm_driver_version(&apm_info.connection_version);
1744			if (error != APM_SUCCESS) {
1745				apm_error("driver version", error);
1746				/* Fall back to an APM 1.0 connection. */
1747				apm_info.connection_version = 0x100;
1748			}
1749		}
1750	}
1751
1752	if (debug)
1753		printk(KERN_INFO "apm: Connection version %d.%d\n",
1754			(apm_info.connection_version >> 8) & 0xff,
1755			apm_info.connection_version & 0xff);
1756
1757#ifdef CONFIG_APM_DO_ENABLE
1758	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1759		/*
1760		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1761		 * is booted with PM disabled but not in the docking station.
1762		 * Unfortunate ...
1763		 */
1764		error = apm_enable_power_management(1);
1765		if (error) {
1766			apm_error("enable power management", error);
1767			return -1;
1768		}
1769	}
1770#endif
1771
1772	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1773	    && (apm_info.connection_version > 0x0100)) {
1774		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1775		if (error) {
1776			apm_error("engage power management", error);
1777			return -1;
1778		}
1779	}
1780
1781	if (debug && (num_online_cpus() == 1 || smp)) {
1782		error = apm_get_power_status(&bx, &cx, &dx);
1783		if (error)
1784			printk(KERN_INFO "apm: power status not available\n");
1785		else {
1786			switch ((bx >> 8) & 0xff) {
1787			case 0:
1788				power_stat = "off line";
1789				break;
1790			case 1:
1791				power_stat = "on line";
1792				break;
1793			case 2:
1794				power_stat = "on backup power";
1795				break;
1796			default:
1797				power_stat = "unknown";
1798				break;
1799			}
1800			switch (bx & 0xff) {
1801			case 0:
1802				bat_stat = "high";
1803				break;
1804			case 1:
1805				bat_stat = "low";
1806				break;
1807			case 2:
1808				bat_stat = "critical";
1809				break;
1810			case 3:
1811				bat_stat = "charging";
1812				break;
1813			default:
1814				bat_stat = "unknown";
1815				break;
1816			}
1817			printk(KERN_INFO
1818			       "apm: AC %s, battery status %s, battery life ",
1819			       power_stat, bat_stat);
1820			if ((cx & 0xff) == 0xff)
1821				printk("unknown\n");
1822			else
1823				printk("%d%%\n", cx & 0xff);
1824			if (apm_info.connection_version > 0x100) {
1825				printk(KERN_INFO
1826				       "apm: battery flag 0x%02x, battery life ",
1827				       (cx >> 8) & 0xff);
1828				if (dx == 0xffff)
1829					printk("unknown\n");
1830				else
1831					printk("%d %s\n", dx & 0x7fff,
1832					       (dx & 0x8000) ?
1833					       "minutes" : "seconds");
1834			}
1835		}
1836	}
1837
1838	/* Install our power off handler.. */
1839	if (power_off)
1840		pm_power_off = apm_power_off;
1841
1842	if (num_online_cpus() == 1 || smp) {
1843#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1844		console_blank_hook = apm_console_blank;
1845#endif
1846		apm_mainloop();
1847#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1848		console_blank_hook = NULL;
1849#endif
1850	}
1851
1852	return 0;
1853}
1854
1855#ifndef MODULE
1856static int __init apm_setup(char *str)
1857{
1858	int invert;
1859
1860	while ((str != NULL) && (*str != '\0')) {
1861		if (strncmp(str, "off", 3) == 0)
1862			apm_disabled = 1;
1863		if (strncmp(str, "on", 2) == 0)
1864			apm_disabled = 0;
1865		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1866		    (strncmp(str, "bounce_interval=", 16) == 0))
1867			bounce_interval = simple_strtol(str + 16, NULL, 0);
1868		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1869		    (strncmp(str, "idle_threshold=", 15) == 0))
1870			idle_threshold = simple_strtol(str + 15, NULL, 0);
1871		if ((strncmp(str, "idle-period=", 12) == 0) ||
1872		    (strncmp(str, "idle_period=", 12) == 0))
1873			idle_period = simple_strtol(str + 12, NULL, 0);
1874		invert = (strncmp(str, "no-", 3) == 0) ||
1875			(strncmp(str, "no_", 3) == 0);
1876		if (invert)
1877			str += 3;
1878		if (strncmp(str, "debug", 5) == 0)
1879			debug = !invert;
1880		if ((strncmp(str, "power-off", 9) == 0) ||
1881		    (strncmp(str, "power_off", 9) == 0))
1882			power_off = !invert;
1883		if (strncmp(str, "smp", 3) == 0) {
1884			smp = !invert;
1885			idle_threshold = 100;
1886		}
1887		if ((strncmp(str, "allow-ints", 10) == 0) ||
1888		    (strncmp(str, "allow_ints", 10) == 0))
1889			apm_info.allow_ints = !invert;
1890		if ((strncmp(str, "broken-psr", 10) == 0) ||
1891		    (strncmp(str, "broken_psr", 10) == 0))
1892			apm_info.get_power_status_broken = !invert;
1893		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1894		    (strncmp(str, "realmode_power_off", 18) == 0))
1895			apm_info.realmode_power_off = !invert;
1896		str = strchr(str, ',');
1897		if (str != NULL)
1898			str += strspn(str, ", \t");
1899	}
1900	return 1;
1901}
1902
1903__setup("apm=", apm_setup);
1904#endif
1905
1906static const struct file_operations apm_bios_fops = {
1907	.owner		= THIS_MODULE,
1908	.read		= do_read,
1909	.poll		= do_poll,
1910	.unlocked_ioctl	= do_ioctl,
1911	.open		= do_open,
1912	.release	= do_release,
1913	.llseek		= noop_llseek,
1914};
1915
1916static struct miscdevice apm_device = {
1917	APM_MINOR_DEV,
1918	"apm_bios",
1919	&apm_bios_fops
1920};
1921
1922
1923/* Simple "print if true" callback */
1924static int __init print_if_true(const struct dmi_system_id *d)
1925{
1926	printk("%s\n", d->ident);
1927	return 0;
1928}
1929
1930/*
1931 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1932 * disabled before the suspend. Linux used to get terribly confused by that.
1933 */
1934static int __init broken_ps2_resume(const struct dmi_system_id *d)
1935{
1936	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1937	       "workaround hopefully not needed.\n", d->ident);
1938	return 0;
1939}
1940
1941/* Some bioses have a broken protected mode poweroff and need to use realmode */
1942static int __init set_realmode_power_off(const struct dmi_system_id *d)
1943{
1944	if (apm_info.realmode_power_off == 0) {
1945		apm_info.realmode_power_off = 1;
1946		printk(KERN_INFO "%s bios detected. "
1947		       "Using realmode poweroff only.\n", d->ident);
1948	}
1949	return 0;
1950}
1951
1952/* Some laptops require interrupts to be enabled during APM calls */
1953static int __init set_apm_ints(const struct dmi_system_id *d)
1954{
1955	if (apm_info.allow_ints == 0) {
1956		apm_info.allow_ints = 1;
1957		printk(KERN_INFO "%s machine detected. "
1958		       "Enabling interrupts during APM calls.\n", d->ident);
1959	}
1960	return 0;
1961}
1962
1963/* Some APM bioses corrupt memory or just plain do not work */
1964static int __init apm_is_horked(const struct dmi_system_id *d)
1965{
1966	if (apm_info.disabled == 0) {
1967		apm_info.disabled = 1;
1968		printk(KERN_INFO "%s machine detected. "
1969		       "Disabling APM.\n", d->ident);
1970	}
1971	return 0;
1972}
1973
1974static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1975{
1976	if (apm_info.disabled == 0) {
1977		apm_info.disabled = 1;
1978		printk(KERN_INFO "%s machine detected. "
1979		       "Disabling APM.\n", d->ident);
1980		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1981		printk(KERN_INFO "download from support.intel.com\n");
1982	}
1983	return 0;
1984}
1985
1986/* Some APM bioses hang on APM idle calls */
1987static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1988{
1989	if (apm_info.forbid_idle == 0) {
1990		apm_info.forbid_idle = 1;
1991		printk(KERN_INFO "%s machine detected. "
1992		       "Disabling APM idle calls.\n", d->ident);
1993	}
1994	return 0;
1995}
1996
1997/*
1998 *  Check for clue free BIOS implementations who use
1999 *  the following QA technique
2000 *
2001 *      [ Write BIOS Code ]<------
2002 *               |                ^
2003 *      < Does it Compile >----N--
2004 *               |Y               ^
2005 *	< Does it Boot Win98 >-N--
2006 *               |Y
2007 *           [Ship It]
2008 *
2009 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2010 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2011 */
2012static int __init broken_apm_power(const struct dmi_system_id *d)
2013{
2014	apm_info.get_power_status_broken = 1;
2015	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2016	       "disabling power status reporting.\n");
2017	return 0;
2018}
2019
2020/*
2021 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2022 * have this problem).
2023 */
2024static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2025{
2026	apm_info.get_power_status_swabinminutes = 1;
2027	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2028	       "in minutes and wrong byte order.\n");
2029	return 0;
2030}
2031
2032static const struct dmi_system_id apm_dmi_table[] __initconst = {
2033	{
2034		print_if_true,
2035		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2036		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2037			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2038	},
2039	{	/* Handle problems with APM on the C600 */
2040		broken_ps2_resume, "Dell Latitude C600",
2041		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2042			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2043	},
2044	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2045		set_apm_ints, "Dell Latitude",
2046		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2047			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2048	},
2049	{	/* APM crashes */
2050		apm_is_horked, "Dell Inspiron 2500",
2051		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2052			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2053			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2054			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2055	},
2056	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2057		set_apm_ints, "Dell Inspiron", {
2058			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2059			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2060	},
2061	{	/* Handle problems with APM on Inspiron 5000e */
2062		broken_apm_power, "Dell Inspiron 5000e",
2063		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2064			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2065			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2066	},
2067	{	/* Handle problems with APM on Inspiron 2500 */
2068		broken_apm_power, "Dell Inspiron 2500",
2069		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2070			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2071			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2072	},
2073	{	/* APM crashes */
2074		apm_is_horked, "Dell Dimension 4100",
2075		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2076			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2077			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2078			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2079	},
2080	{	/* Allow interrupts during suspend on Compaq Laptops*/
2081		set_apm_ints, "Compaq 12XL125",
2082		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2083			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2084			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2085			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2086	},
2087	{	/* Allow interrupts during APM or the clock goes slow */
2088		set_apm_ints, "ASUSTeK",
2089		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2090			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2091	},
2092	{	/* APM blows on shutdown */
2093		apm_is_horked, "ABIT KX7-333[R]",
2094		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2095			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2096	},
2097	{	/* APM crashes */
2098		apm_is_horked, "Trigem Delhi3",
2099		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2100			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2101	},
2102	{	/* APM crashes */
2103		apm_is_horked, "Fujitsu-Siemens",
2104		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2105			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2106	},
2107	{	/* APM crashes */
2108		apm_is_horked_d850md, "Intel D850MD",
2109		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2110			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2111	},
2112	{	/* APM crashes */
2113		apm_is_horked, "Intel D810EMO",
2114		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2115			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2116	},
2117	{	/* APM crashes */
2118		apm_is_horked, "Dell XPS-Z",
2119		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2120			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2121			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2122	},
2123	{	/* APM crashes */
2124		apm_is_horked, "Sharp PC-PJ/AX",
2125		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2126			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2127			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2128			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2129	},
2130	{	/* APM crashes */
2131		apm_is_horked, "Dell Inspiron 2500",
2132		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2133			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2134			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2135			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2136	},
2137	{	/* APM idle hangs */
2138		apm_likes_to_melt, "Jabil AMD",
2139		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2140			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2141	},
2142	{	/* APM idle hangs */
2143		apm_likes_to_melt, "AMI Bios",
2144		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2145			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2146	},
2147	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2148		swab_apm_power_in_minutes, "Sony VAIO",
2149		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2150			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2151			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2152	},
2153	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2154		swab_apm_power_in_minutes, "Sony VAIO",
2155		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2156			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2157			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2158	},
2159	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2160		swab_apm_power_in_minutes, "Sony VAIO",
2161		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2162			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2163			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2164	},
2165	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2166		swab_apm_power_in_minutes, "Sony VAIO",
2167		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2168			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2169			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2170	},
2171	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2172		swab_apm_power_in_minutes, "Sony VAIO",
2173		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2174			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2175			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2176	},
2177	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2178		swab_apm_power_in_minutes, "Sony VAIO",
2179		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2180			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2181			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2182	},
2183	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2184		swab_apm_power_in_minutes, "Sony VAIO",
2185		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2186			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2187			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2188	},
2189	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2190		swab_apm_power_in_minutes, "Sony VAIO",
2191		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2192			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2193			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2194	},
2195	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2196		swab_apm_power_in_minutes, "Sony VAIO",
2197		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2198			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2199			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2200	},
2201	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2202		swab_apm_power_in_minutes, "Sony VAIO",
2203		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2204			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2205			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2206	},
2207
2208	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2209		swab_apm_power_in_minutes, "Sony VAIO",
2210		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2211			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2212			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2213	},
2214	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2215		swab_apm_power_in_minutes, "Sony VAIO",
2216		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2217			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2218			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2219	},
2220	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2221		swab_apm_power_in_minutes, "Sony VAIO",
2222		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2223			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2224			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2225	},
2226	{	/* broken PM poweroff bios */
2227		set_realmode_power_off, "Award Software v4.60 PGMA",
2228		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2229			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2230			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2231	},
2232
2233	/* Generic per vendor APM settings  */
2234
2235	{	/* Allow interrupts during suspend on IBM laptops */
2236		set_apm_ints, "IBM",
2237		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2238	},
2239
2240	{ }
2241};
2242
2243/*
2244 * Just start the APM thread. We do NOT want to do APM BIOS
2245 * calls from anything but the APM thread, if for no other reason
2246 * than the fact that we don't trust the APM BIOS. This way,
2247 * most common APM BIOS problems that lead to protection errors
2248 * etc will have at least some level of being contained...
2249 *
2250 * In short, if something bad happens, at least we have a choice
2251 * of just killing the apm thread..
2252 */
2253static int __init apm_init(void)
2254{
2255	struct desc_struct *gdt;
2256	int err;
2257
2258	dmi_check_system(apm_dmi_table);
2259
2260	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2261		printk(KERN_INFO "apm: BIOS not found.\n");
2262		return -ENODEV;
2263	}
2264	printk(KERN_INFO
2265	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2266	       ((apm_info.bios.version >> 8) & 0xff),
2267	       (apm_info.bios.version & 0xff),
2268	       apm_info.bios.flags,
2269	       driver_version);
2270	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2271		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2272		return -ENODEV;
2273	}
2274
2275	if (allow_ints)
2276		apm_info.allow_ints = 1;
2277	if (broken_psr)
2278		apm_info.get_power_status_broken = 1;
2279	if (realmode_power_off)
2280		apm_info.realmode_power_off = 1;
2281	/* User can override, but default is to trust DMI */
2282	if (apm_disabled != -1)
2283		apm_info.disabled = apm_disabled;
2284
2285	/*
2286	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2287	 * but is reportedly a 1.0 BIOS.
2288	 */
2289	if (apm_info.bios.version == 0x001)
2290		apm_info.bios.version = 0x100;
2291
2292	/* BIOS < 1.2 doesn't set cseg_16_len */
2293	if (apm_info.bios.version < 0x102)
2294		apm_info.bios.cseg_16_len = 0; /* 64k */
2295
2296	if (debug) {
2297		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2298			apm_info.bios.cseg, apm_info.bios.offset,
2299			apm_info.bios.cseg_16, apm_info.bios.dseg);
2300		if (apm_info.bios.version > 0x100)
2301			printk(" cseg len %x, dseg len %x",
2302				apm_info.bios.cseg_len,
2303				apm_info.bios.dseg_len);
2304		if (apm_info.bios.version > 0x101)
2305			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2306		printk("\n");
2307	}
2308
2309	if (apm_info.disabled) {
2310		pr_notice("disabled on user request.\n");
2311		return -ENODEV;
2312	}
2313	if ((num_online_cpus() > 1) && !power_off && !smp) {
2314		pr_notice("disabled - APM is not SMP safe.\n");
2315		apm_info.disabled = 1;
2316		return -ENODEV;
2317	}
2318	if (!acpi_disabled) {
2319		pr_notice("overridden by ACPI.\n");
2320		apm_info.disabled = 1;
2321		return -ENODEV;
2322	}
2323
2324	/*
2325	 * Set up the long jump entry point to the APM BIOS, which is called
2326	 * from inline assembly.
2327	 */
2328	apm_bios_entry.offset = apm_info.bios.offset;
2329	apm_bios_entry.segment = APM_CS;
2330
2331	/*
2332	 * The APM 1.1 BIOS is supposed to provide limit information that it
2333	 * recognizes.  Many machines do this correctly, but many others do
2334	 * not restrict themselves to their claimed limit.  When this happens,
2335	 * they will cause a segmentation violation in the kernel at boot time.
2336	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2337	 *
2338	 * Note we only set APM segments on CPU zero, since we pin the APM
2339	 * code to that CPU.
2340	 */
2341	gdt = get_cpu_gdt_rw(0);
2342	set_desc_base(&gdt[APM_CS >> 3],
2343		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2344	set_desc_base(&gdt[APM_CS_16 >> 3],
2345		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2346	set_desc_base(&gdt[APM_DS >> 3],
2347		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2348
2349	proc_create_single("apm", 0, NULL, proc_apm_show);
2350
2351	kapmd_task = kthread_create(apm, NULL, "kapmd");
2352	if (IS_ERR(kapmd_task)) {
2353		pr_err("disabled - Unable to start kernel thread\n");
 
2354		err = PTR_ERR(kapmd_task);
2355		kapmd_task = NULL;
2356		remove_proc_entry("apm", NULL);
2357		return err;
2358	}
2359	wake_up_process(kapmd_task);
2360
2361	if (num_online_cpus() > 1 && !smp) {
2362		printk(KERN_NOTICE
2363		       "apm: disabled - APM is not SMP safe (power off active).\n");
2364		return 0;
2365	}
2366
2367	/*
2368	 * Note we don't actually care if the misc_device cannot be registered.
2369	 * this driver can do its job without it, even if userspace can't
2370	 * control it.  just log the error
2371	 */
2372	if (misc_register(&apm_device))
2373		printk(KERN_WARNING "apm: Could not register misc device.\n");
2374
2375	if (HZ != 100)
2376		idle_period = (idle_period * HZ) / 100;
2377	if (idle_threshold < 100) {
2378		cpuidle_poll_state_init(&apm_idle_driver);
2379		if (!cpuidle_register_driver(&apm_idle_driver))
2380			if (cpuidle_register_device(&apm_cpuidle_device))
2381				cpuidle_unregister_driver(&apm_idle_driver);
2382	}
2383
2384	return 0;
2385}
2386
2387static void __exit apm_exit(void)
2388{
2389	int error;
2390
2391	cpuidle_unregister_device(&apm_cpuidle_device);
2392	cpuidle_unregister_driver(&apm_idle_driver);
2393
 
 
 
 
 
 
2394	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2395	    && (apm_info.connection_version > 0x0100)) {
2396		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2397		if (error)
2398			apm_error("disengage power management", error);
2399	}
2400	misc_deregister(&apm_device);
2401	remove_proc_entry("apm", NULL);
2402	if (power_off)
2403		pm_power_off = NULL;
2404	if (kapmd_task) {
2405		kthread_stop(kapmd_task);
2406		kapmd_task = NULL;
2407	}
2408}
2409
2410module_init(apm_init);
2411module_exit(apm_exit);
2412
2413MODULE_AUTHOR("Stephen Rothwell");
2414MODULE_DESCRIPTION("Advanced Power Management");
2415MODULE_LICENSE("GPL");
2416module_param(debug, bool, 0644);
2417MODULE_PARM_DESC(debug, "Enable debug mode");
2418module_param(power_off, bool, 0444);
2419MODULE_PARM_DESC(power_off, "Enable power off");
2420module_param(bounce_interval, int, 0444);
2421MODULE_PARM_DESC(bounce_interval,
2422		"Set the number of ticks to ignore suspend bounces");
2423module_param(allow_ints, bool, 0444);
2424MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2425module_param(broken_psr, bool, 0444);
2426MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2427module_param(realmode_power_off, bool, 0444);
2428MODULE_PARM_DESC(realmode_power_off,
2429		"Switch to real mode before powering off");
2430module_param(idle_threshold, int, 0444);
2431MODULE_PARM_DESC(idle_threshold,
2432	"System idle percentage above which to make APM BIOS idle calls");
2433module_param(idle_period, int, 0444);
2434MODULE_PARM_DESC(idle_period,
2435	"Period (in sec/100) over which to calculate the idle percentage");
2436module_param(smp, bool, 0444);
2437MODULE_PARM_DESC(smp,
2438	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2439MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);