arch/x86/kernel/apm

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This source file includes following definitions.
apm_error
__apm_irq_save
apm_irq_restore
__apm_bios_call
on_cpu0
apm_bios_call
__apm_bios_call_simple
apm_bios_call_simple
apm_driver_version
apm_get_event
set_power_state
set_system_power_state
apm_do_idle
apm_do_busy
apm_cpu_idle
apm_power_off
apm_enable_power_management
apm_get_power_status
apm_get_battery_status
apm_engage_power_management
apm_console_blank
queue_empty
get_queued_event
queue_event
reinit_timer
suspend
standby
get_event
check_events
apm_event_handler
apm_mainloop
check_apm_user
do_read
do_poll
do_ioctl
do_release
do_open
proc_apm_show
apm
apm_setup
print_if_true
broken_ps2_resume
set_realmode_power_off
set_apm_ints
apm_is_horked
apm_is_horked_d850md
apm_likes_to_melt
broken_apm_power
swab_apm_power_in_minutes
apm_init
apm_exit
   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* -*- linux-c -*-
   3  * APM BIOS driver for Linux
   4  * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
   5  *
   6  * Initial development of this driver was funded by NEC Australia P/L
   7  *      and NEC Corporation
   8  *
   9  * October 1995, Rik Faith (faith@cs.unc.edu):
  10  *    Minor enhancements and updates (to the patch set) for 1.3.x
  11  *    Documentation
  12  * January 1996, Rik Faith (faith@cs.unc.edu):
  13  *    Make /proc/apm easy to format (bump driver version)
  14  * March 1996, Rik Faith (faith@cs.unc.edu):
  15  *    Prohibit APM BIOS calls unless apm_enabled.
  16  *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
  17  * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
  18  *    Version 1.0 and 1.1
  19  * May 1996, Version 1.2
  20  * Feb 1998, Version 1.3
  21  * Feb 1998, Version 1.4
  22  * Aug 1998, Version 1.5
  23  * Sep 1998, Version 1.6
  24  * Nov 1998, Version 1.7
  25  * Jan 1999, Version 1.8
  26  * Jan 1999, Version 1.9
  27  * Oct 1999, Version 1.10
  28  * Nov 1999, Version 1.11
  29  * Jan 2000, Version 1.12
  30  * Feb 2000, Version 1.13
  31  * Nov 2000, Version 1.14
  32  * Oct 2001, Version 1.15
  33  * Jan 2002, Version 1.16
  34  * Oct 2002, Version 1.16ac
  35  *
  36  * History:
  37  *    0.6b: first version in official kernel, Linux 1.3.46
  38  *    0.7: changed /proc/apm format, Linux 1.3.58
  39  *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
  40  *    0.9: only call bios if bios is present, Linux 1.3.72
  41  *    1.0: use fixed device number, consolidate /proc/apm into this file,
  42  *         Linux 1.3.85
  43  *    1.1: support user-space standby and suspend, power off after system
  44  *         halted, Linux 1.3.98
  45  *    1.2: When resetting RTC after resume, take care so that the time
  46  *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
  47  *         <jtoth@princeton.edu>); improve interaction between
  48  *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
  49  *    1.2a:Simple change to stop mysterious bug reports with SMP also added
  50  *         levels to the printk calls. APM is not defined for SMP machines.
  51  *         The new replacement for it is, but Linux doesn't yet support this.
  52  *         Alan Cox Linux 2.1.55
  53  *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
  54  *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
  55  *         Dean Gaudet <dgaudet@arctic.org>.
  56  *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
  57  *    1.5: Fix segment register reloading (in case of bad segments saved
  58  *         across BIOS call).
  59  *         Stephen Rothwell
  60  *    1.6: Cope with compiler/assembler differences.
  61  *         Only try to turn off the first display device.
  62  *         Fix OOPS at power off with no APM BIOS by Jan Echternach
  63  *                   <echter@informatik.uni-rostock.de>
  64  *         Stephen Rothwell
  65  *    1.7: Modify driver's cached copy of the disabled/disengaged flags
  66  *         to reflect current state of APM BIOS.
  67  *         Chris Rankin <rankinc@bellsouth.net>
  68  *         Reset interrupt 0 timer to 100Hz after suspend
  69  *         Chad Miller <cmiller@surfsouth.com>
  70  *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
  71  *         Richard Gooch <rgooch@atnf.csiro.au>
  72  *         Allow boot time disabling of APM
  73  *         Make boot messages far less verbose by default
  74  *         Make asm safer
  75  *         Stephen Rothwell
  76  *    1.8: Add CONFIG_APM_RTC_IS_GMT
  77  *         Richard Gooch <rgooch@atnf.csiro.au>
  78  *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
  79  *         remove dependency on CONFIG_PROC_FS
  80  *         Stephen Rothwell
  81  *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
  82  *         Try to cope with BIOS's that need to have all display
  83  *         devices blanked and not just the first one.
  84  *         Ross Paterson <ross@soi.city.ac.uk>
  85  *         Fix segment limit setting it has always been wrong as
  86  *         the segments needed to have byte granularity.
  87  *         Mark a few things __init.
  88  *         Add hack to allow power off of SMP systems by popular request.
  89  *         Use CONFIG_SMP instead of __SMP__
  90  *         Ignore BOUNCES for three seconds.
  91  *         Stephen Rothwell
  92  *   1.10: Fix for Thinkpad return code.
  93  *         Merge 2.2 and 2.3 drivers.
  94  *         Remove APM dependencies in arch/i386/kernel/process.c
  95  *         Remove APM dependencies in drivers/char/sysrq.c
  96  *         Reset time across standby.
  97  *         Allow more inititialisation on SMP.
  98  *         Remove CONFIG_APM_POWER_OFF and make it boot time
  99  *         configurable (default on).
 100  *         Make debug only a boot time parameter (remove APM_DEBUG).
 101  *         Try to blank all devices on any error.
 102  *   1.11: Remove APM dependencies in drivers/char/console.c
 103  *         Check nr_running to detect if we are idle (from
 104  *         Borislav Deianov <borislav@lix.polytechnique.fr>)
 105  *         Fix for bioses that don't zero the top part of the
 106  *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
 107  *         (reported by Panos Katsaloulis <teras@writeme.com>).
 108  *         Real mode power off patch (Walter Hofmann
 109  *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
 110  *   1.12: Remove CONFIG_SMP as the compiler will optimize
 111  *         the code away anyway (smp_num_cpus == 1 in UP)
 112  *         noted by Artur Skawina <skawina@geocities.com>.
 113  *         Make power off under SMP work again.
 114  *         Fix thinko with initial engaging of BIOS.
 115  *         Make sure power off only happens on CPU 0
 116  *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
 117  *         Do error notification to user mode if BIOS calls fail.
 118  *         Move entrypoint offset fix to ...boot/setup.S
 119  *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
 120  *         Remove smp-power-off. SMP users must now specify
 121  *         "apm=power-off" on the kernel command line. Suggested
 122  *         by Jim Avera <jima@hal.com>, modified by Alan Cox
 123  *         <alan@lxorguk.ukuu.org.uk>.
 124  *         Register the /proc/apm entry even on SMP so that
 125  *         scripts that check for it before doing power off
 126  *         work (Jim Avera <jima@hal.com>).
 127  *   1.13: Changes for new pm_ interfaces (Andy Henroid
 128  *         <andy_henroid@yahoo.com>).
 129  *         Modularize the code.
 130  *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
 131  *         is now the way life works).
 132  *         Fix thinko in suspend() (wrong return).
 133  *         Notify drivers on critical suspend.
 134  *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
 135  *         modified by sfr).
 136  *         Disable interrupts while we are suspended (Andy Henroid
 137  *         <andy_henroid@yahoo.com> fixed by sfr).
 138  *         Make power off work on SMP again (Tony Hoyle
 139  *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
 140  *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
 141  *         interval is now configurable.
 142  *   1.14: Make connection version persist across module unload/load.
 143  *         Enable and engage power management earlier.
 144  *         Disengage power management on module unload.
 145  *         Changed to use the sysrq-register hack for registering the
 146  *         power off function called by magic sysrq based upon discussions
 147  *         in irc://irc.openprojects.net/#kernelnewbies
 148  *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
 149  *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
 150  *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
 151  *         Work around byte swap bug in one of the Vaio's BIOS's
 152  *         (Marc Boucher <marc@mbsi.ca>).
 153  *         Exposed the disable flag to dmi so that we can handle known
 154  *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
 155  *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
 156  *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
 157  *         If an APM idle fails log it and idle sensibly
 158  *   1.15: Don't queue events to clients who open the device O_WRONLY.
 159  *         Don't expect replies from clients who open the device O_RDONLY.
 160  *         (Idea from Thomas Hood)
 161  *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
 162  *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
 163  *         Notify listeners of standby or suspend events before notifying
 164  *         drivers. Return EBUSY to ioctl() if suspend is rejected.
 165  *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
 166  *         Ignore first resume after we generate our own resume event
 167  *         after a suspend (Thomas Hood)
 168  *         Daemonize now gets rid of our controlling terminal (sfr).
 169  *         CONFIG_APM_CPU_IDLE now just affects the default value of
 170  *         idle_threshold (sfr).
 171  *         Change name of kernel apm daemon (as it no longer idles) (sfr).
 172  *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
 173  *         make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
 174  *         TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
 175  *
 176  * APM 1.1 Reference:
 177  *
 178  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 179  *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
 180  *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
 181  *
 182  * [This document is available free from Intel by calling 800.628.8686 (fax
 183  * 916.356.6100) or 800.548.4725; or from
 184  * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
 185  * available from Microsoft by calling 206.882.8080.]
 186  *
 187  * APM 1.2 Reference:
 188  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
 189  *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
 190  *
 191  * [This document is available from Microsoft at:
 192  *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
 193  */
 194 
 195 #define pr_fmt(fmt) "apm: " fmt
 196 
 197 #include <linux/module.h>
 198 
 199 #include <linux/poll.h>
 200 #include <linux/types.h>
 201 #include <linux/stddef.h>
 202 #include <linux/timer.h>
 203 #include <linux/fcntl.h>
 204 #include <linux/slab.h>
 205 #include <linux/stat.h>
 206 #include <linux/proc_fs.h>
 207 #include <linux/seq_file.h>
 208 #include <linux/miscdevice.h>
 209 #include <linux/apm_bios.h>
 210 #include <linux/init.h>
 211 #include <linux/time.h>
 212 #include <linux/sched/signal.h>
 213 #include <linux/sched/cputime.h>
 214 #include <linux/pm.h>
 215 #include <linux/capability.h>
 216 #include <linux/device.h>
 217 #include <linux/kernel.h>
 218 #include <linux/freezer.h>
 219 #include <linux/smp.h>
 220 #include <linux/dmi.h>
 221 #include <linux/suspend.h>
 222 #include <linux/kthread.h>
 223 #include <linux/jiffies.h>
 224 #include <linux/acpi.h>
 225 #include <linux/syscore_ops.h>
 226 #include <linux/i8253.h>
 227 #include <linux/cpuidle.h>
 228 
 229 #include <linux/uaccess.h>
 230 #include <asm/desc.h>
 231 #include <asm/olpc.h>
 232 #include <asm/paravirt.h>
 233 #include <asm/reboot.h>
 234 #include <asm/nospec-branch.h>
 235 
 236 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
 237 extern int (*console_blank_hook)(int);
 238 #endif
 239 
 240 /*
 241  * The apm_bios device is one of the misc char devices.
 242  * This is its minor number.
 243  */
 244 #define APM_MINOR_DEV   134
 245 
 246 /*
 247  * Various options can be changed at boot time as follows:
 248  * (We allow underscores for compatibility with the modules code)
 249  *      apm=on/off                      enable/disable APM
 250  *          [no-]allow[-_]ints          allow interrupts during BIOS calls
 251  *          [no-]broken[-_]psr          BIOS has a broken GetPowerStatus call
 252  *          [no-]realmode[-_]power[-_]off       switch to real mode before
 253  *                                              powering off
 254  *          [no-]debug                  log some debugging messages
 255  *          [no-]power[-_]off           power off on shutdown
 256  *          [no-]smp                    Use apm even on an SMP box
 257  *          bounce[-_]interval=<n>      number of ticks to ignore suspend
 258  *                                      bounces
 259  *          idle[-_]threshold=<n>       System idle percentage above which to
 260  *                                      make APM BIOS idle calls. Set it to
 261  *                                      100 to disable.
 262  *          idle[-_]period=<n>          Period (in 1/100s of a second) over
 263  *                                      which the idle percentage is
 264  *                                      calculated.
 265  */
 266 
 267 /* KNOWN PROBLEM MACHINES:
 268  *
 269  * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
 270  *                         [Confirmed by TI representative]
 271  * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
 272  *                    [Confirmed by BIOS disassembly]
 273  *                    [This may work now ...]
 274  * P: Toshiba 1950S: battery life information only gets updated after resume
 275  * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
 276  *      broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
 277  * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
 278  *      Neale Banks <neale@lowendale.com.au> December 2000
 279  *
 280  * Legend: U = unusable with APM patches
 281  *         P = partially usable with APM patches
 282  */
 283 
 284 /*
 285  * Define as 1 to make the driver always call the APM BIOS busy
 286  * routine even if the clock was not reported as slowed by the
 287  * idle routine.  Otherwise, define as 0.
 288  */
 289 #define ALWAYS_CALL_BUSY   1
 290 
 291 /*
 292  * Define to make the APM BIOS calls zero all data segment registers (so
 293  * that an incorrect BIOS implementation will cause a kernel panic if it
 294  * tries to write to arbitrary memory).
 295  */
 296 #define APM_ZERO_SEGS
 297 
 298 #include <asm/apm.h>
 299 
 300 /*
 301  * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
 302  * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
 303  * David Chen <chen@ctpa04.mit.edu>
 304  */
 305 #undef INIT_TIMER_AFTER_SUSPEND
 306 
 307 #ifdef INIT_TIMER_AFTER_SUSPEND
 308 #include <linux/timex.h>
 309 #include <asm/io.h>
 310 #include <linux/delay.h>
 311 #endif
 312 
 313 /*
 314  * Need to poll the APM BIOS every second
 315  */
 316 #define APM_CHECK_TIMEOUT       (HZ)
 317 
 318 /*
 319  * Ignore suspend events for this amount of time after a resume
 320  */
 321 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
 322 
 323 /*
 324  * Maximum number of events stored
 325  */
 326 #define APM_MAX_EVENTS          20
 327 
 328 /*
 329  * The per-file APM data
 330  */
 331 struct apm_user {
 332         int             magic;
 333         struct apm_user *next;
 334         unsigned int    suser: 1;
 335         unsigned int    writer: 1;
 336         unsigned int    reader: 1;
 337         unsigned int    suspend_wait: 1;
 338         int             suspend_result;
 339         int             suspends_pending;
 340         int             standbys_pending;
 341         int             suspends_read;
 342         int             standbys_read;
 343         int             event_head;
 344         int             event_tail;
 345         apm_event_t     events[APM_MAX_EVENTS];
 346 };
 347 
 348 /*
 349  * The magic number in apm_user
 350  */
 351 #define APM_BIOS_MAGIC          0x4101
 352 
 353 /*
 354  * idle percentage above which bios idle calls are done
 355  */
 356 #ifdef CONFIG_APM_CPU_IDLE
 357 #define DEFAULT_IDLE_THRESHOLD  95
 358 #else
 359 #define DEFAULT_IDLE_THRESHOLD  100
 360 #endif
 361 #define DEFAULT_IDLE_PERIOD     (100 / 3)
 362 
 363 static int apm_cpu_idle(struct cpuidle_device *dev,
 364                         struct cpuidle_driver *drv, int index);
 365 
 366 static struct cpuidle_driver apm_idle_driver = {
 367         .name = "apm_idle",
 368         .owner = THIS_MODULE,
 369         .states = {
 370                 { /* entry 0 is for polling */ },
 371                 { /* entry 1 is for APM idle */
 372                         .name = "APM",
 373                         .desc = "APM idle",
 374                         .exit_latency = 250,    /* WAG */
 375                         .target_residency = 500,        /* WAG */
 376                         .enter = &apm_cpu_idle
 377                 },
 378         },
 379         .state_count = 2,
 380 };
 381 
 382 static struct cpuidle_device apm_cpuidle_device;
 383 
 384 /*
 385  * Local variables
 386  */
 387 __visible struct {
 388         unsigned long   offset;
 389         unsigned short  segment;
 390 } apm_bios_entry;
 391 static int clock_slowed;
 392 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
 393 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
 394 static int suspends_pending;
 395 static int standbys_pending;
 396 static int ignore_sys_suspend;
 397 static int ignore_normal_resume;
 398 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
 399 
 400 static bool debug __read_mostly;
 401 static bool smp __read_mostly;
 402 static int apm_disabled = -1;
 403 #ifdef CONFIG_SMP
 404 static bool power_off;
 405 #else
 406 static bool power_off = 1;
 407 #endif
 408 static bool realmode_power_off;
 409 #ifdef CONFIG_APM_ALLOW_INTS
 410 static bool allow_ints = 1;
 411 #else
 412 static bool allow_ints;
 413 #endif
 414 static bool broken_psr;
 415 
 416 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
 417 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
 418 static struct apm_user *user_list;
 419 static DEFINE_SPINLOCK(user_list_lock);
 420 static DEFINE_MUTEX(apm_mutex);
 421 
 422 /*
 423  * Set up a segment that references the real mode segment 0x40
 424  * that extends up to the end of page zero (that we have reserved).
 425  * This is for buggy BIOS's that refer to (real mode) segment 0x40
 426  * even though they are called in protected mode.
 427  */
 428 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
 429                         (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
 430 
 431 static const char driver_version[] = "1.16ac";  /* no spaces */
 432 
 433 static struct task_struct *kapmd_task;
 434 
 435 /*
 436  *      APM event names taken from the APM 1.2 specification. These are
 437  *      the message codes that the BIOS uses to tell us about events
 438  */
 439 static const char * const apm_event_name[] = {
 440         "system standby",
 441         "system suspend",
 442         "normal resume",
 443         "critical resume",
 444         "low battery",
 445         "power status change",
 446         "update time",
 447         "critical suspend",
 448         "user standby",
 449         "user suspend",
 450         "system standby resume",
 451         "capabilities change"
 452 };
 453 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
 454 
 455 typedef struct lookup_t {
 456         int     key;
 457         char    *msg;
 458 } lookup_t;
 459 
 460 /*
 461  *      The BIOS returns a set of standard error codes in AX when the
 462  *      carry flag is set.
 463  */
 464 
 465 static const lookup_t error_table[] = {
 466 /* N/A  { APM_SUCCESS,          "Operation succeeded" }, */
 467         { APM_DISABLED,         "Power management disabled" },
 468         { APM_CONNECTED,        "Real mode interface already connected" },
 469         { APM_NOT_CONNECTED,    "Interface not connected" },
 470         { APM_16_CONNECTED,     "16 bit interface already connected" },
 471 /* N/A  { APM_16_UNSUPPORTED,   "16 bit interface not supported" }, */
 472         { APM_32_CONNECTED,     "32 bit interface already connected" },
 473         { APM_32_UNSUPPORTED,   "32 bit interface not supported" },
 474         { APM_BAD_DEVICE,       "Unrecognized device ID" },
 475         { APM_BAD_PARAM,        "Parameter out of range" },
 476         { APM_NOT_ENGAGED,      "Interface not engaged" },
 477         { APM_BAD_FUNCTION,     "Function not supported" },
 478         { APM_RESUME_DISABLED,  "Resume timer disabled" },
 479         { APM_BAD_STATE,        "Unable to enter requested state" },
 480 /* N/A  { APM_NO_EVENTS,        "No events pending" }, */
 481         { APM_NO_ERROR,         "BIOS did not set a return code" },
 482         { APM_NOT_PRESENT,      "No APM present" }
 483 };
 484 #define ERROR_COUNT     ARRAY_SIZE(error_table)
 485 
 486 /**
 487  *      apm_error       -       display an APM error
 488  *      @str: information string
 489  *      @err: APM BIOS return code
 490  *
 491  *      Write a meaningful log entry to the kernel log in the event of
 492  *      an APM error.  Note that this also handles (negative) kernel errors.
 493  */
 494 
 495 static void apm_error(char *str, int err)
 496 {
 497         int i;
 498 
 499         for (i = 0; i < ERROR_COUNT; i++)
 500                 if (error_table[i].key == err)
 501                         break;
 502         if (i < ERROR_COUNT)
 503                 pr_notice("%s: %s\n", str, error_table[i].msg);
 504         else if (err < 0)
 505                 pr_notice("%s: linux error code %i\n", str, err);
 506         else
 507                 pr_notice("%s: unknown error code %#2.2x\n",
 508                        str, err);
 509 }
 510 
 511 /*
 512  * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
 513  * apm_info.allow_ints, we are being really paranoid here!  Not only
 514  * are interrupts disabled, but all the segment registers (except SS)
 515  * are saved and zeroed this means that if the BIOS tries to reference
 516  * any data without explicitly loading the segment registers, the kernel
 517  * will fault immediately rather than have some unforeseen circumstances
 518  * for the rest of the kernel.  And it will be very obvious!  :-) Doing
 519  * this depends on CS referring to the same physical memory as DS so that
 520  * DS can be zeroed before the call. Unfortunately, we can't do anything
 521  * about the stack segment/pointer.  Also, we tell the compiler that
 522  * everything could change.
 523  *
 524  * Also, we KNOW that for the non error case of apm_bios_call, there
 525  * is no useful data returned in the low order 8 bits of eax.
 526  */
 527 
 528 static inline unsigned long __apm_irq_save(void)
 529 {
 530         unsigned long flags;
 531         local_save_flags(flags);
 532         if (apm_info.allow_ints) {
 533                 if (irqs_disabled_flags(flags))
 534                         local_irq_enable();
 535         } else
 536                 local_irq_disable();
 537 
 538         return flags;
 539 }
 540 
 541 #define apm_irq_save(flags) \
 542         do { flags = __apm_irq_save(); } while (0)
 543 
 544 static inline void apm_irq_restore(unsigned long flags)
 545 {
 546         if (irqs_disabled_flags(flags))
 547                 local_irq_disable();
 548         else if (irqs_disabled())
 549                 local_irq_enable();
 550 }
 551 
 552 #ifdef APM_ZERO_SEGS
 553 #       define APM_DECL_SEGS \
 554                 unsigned int saved_fs; unsigned int saved_gs;
 555 #       define APM_DO_SAVE_SEGS \
 556                 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
 557 #       define APM_DO_RESTORE_SEGS \
 558                 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
 559 #else
 560 #       define APM_DECL_SEGS
 561 #       define APM_DO_SAVE_SEGS
 562 #       define APM_DO_RESTORE_SEGS
 563 #endif
 564 
 565 struct apm_bios_call {
 566         u32 func;
 567         /* In and out */
 568         u32 ebx;
 569         u32 ecx;
 570         /* Out only */
 571         u32 eax;
 572         u32 edx;
 573         u32 esi;
 574 
 575         /* Error: -ENOMEM, or bits 8-15 of eax */
 576         int err;
 577 };
 578 
 579 /**
 580  *      __apm_bios_call - Make an APM BIOS 32bit call
 581  *      @_call: pointer to struct apm_bios_call.
 582  *
 583  *      Make an APM call using the 32bit protected mode interface. The
 584  *      caller is responsible for knowing if APM BIOS is configured and
 585  *      enabled. This call can disable interrupts for a long period of
 586  *      time on some laptops.  The return value is in AH and the carry
 587  *      flag is loaded into AL.  If there is an error, then the error
 588  *      code is returned in AH (bits 8-15 of eax) and this function
 589  *      returns non-zero.
 590  *
 591  *      Note: this makes the call on the current CPU.
 592  */
 593 static long __apm_bios_call(void *_call)
 594 {
 595         APM_DECL_SEGS
 596         unsigned long           flags;
 597         int                     cpu;
 598         struct desc_struct      save_desc_40;
 599         struct desc_struct      *gdt;
 600         struct apm_bios_call    *call = _call;
 601 
 602         cpu = get_cpu();
 603         BUG_ON(cpu != 0);
 604         gdt = get_cpu_gdt_rw(cpu);
 605         save_desc_40 = gdt[0x40 / 8];
 606         gdt[0x40 / 8] = bad_bios_desc;
 607 
 608         apm_irq_save(flags);
 609         firmware_restrict_branch_speculation_start();
 610         APM_DO_SAVE_SEGS;
 611         apm_bios_call_asm(call->func, call->ebx, call->ecx,
 612                           &call->eax, &call->ebx, &call->ecx, &call->edx,
 613                           &call->esi);
 614         APM_DO_RESTORE_SEGS;
 615         firmware_restrict_branch_speculation_end();
 616         apm_irq_restore(flags);
 617         gdt[0x40 / 8] = save_desc_40;
 618         put_cpu();
 619 
 620         return call->eax & 0xff;
 621 }
 622 
 623 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
 624 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
 625 {
 626         int ret;
 627 
 628         /* Don't bother with work_on_cpu in the common case, so we don't
 629          * have to worry about OOM or overhead. */
 630         if (get_cpu() == 0) {
 631                 ret = fn(call);
 632                 put_cpu();
 633         } else {
 634                 put_cpu();
 635                 ret = work_on_cpu(0, fn, call);
 636         }
 637 
 638         /* work_on_cpu can fail with -ENOMEM */
 639         if (ret < 0)
 640                 call->err = ret;
 641         else
 642                 call->err = (call->eax >> 8) & 0xff;
 643 
 644         return ret;
 645 }
 646 
 647 /**
 648  *      apm_bios_call   -       Make an APM BIOS 32bit call (on CPU 0)
 649  *      @call: the apm_bios_call registers.
 650  *
 651  *      If there is an error, it is returned in @call.err.
 652  */
 653 static int apm_bios_call(struct apm_bios_call *call)
 654 {
 655         return on_cpu0(__apm_bios_call, call);
 656 }
 657 
 658 /**
 659  *      __apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
 660  *      @_call: pointer to struct apm_bios_call.
 661  *
 662  *      Make a BIOS call that returns one value only, or just status.
 663  *      If there is an error, then the error code is returned in AH
 664  *      (bits 8-15 of eax) and this function returns non-zero (it can
 665  *      also return -ENOMEM). This is used for simpler BIOS operations.
 666  *      This call may hold interrupts off for a long time on some laptops.
 667  *
 668  *      Note: this makes the call on the current CPU.
 669  */
 670 static long __apm_bios_call_simple(void *_call)
 671 {
 672         u8                      error;
 673         APM_DECL_SEGS
 674         unsigned long           flags;
 675         int                     cpu;
 676         struct desc_struct      save_desc_40;
 677         struct desc_struct      *gdt;
 678         struct apm_bios_call    *call = _call;
 679 
 680         cpu = get_cpu();
 681         BUG_ON(cpu != 0);
 682         gdt = get_cpu_gdt_rw(cpu);
 683         save_desc_40 = gdt[0x40 / 8];
 684         gdt[0x40 / 8] = bad_bios_desc;
 685 
 686         apm_irq_save(flags);
 687         firmware_restrict_branch_speculation_start();
 688         APM_DO_SAVE_SEGS;
 689         error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
 690                                          &call->eax);
 691         APM_DO_RESTORE_SEGS;
 692         firmware_restrict_branch_speculation_end();
 693         apm_irq_restore(flags);
 694         gdt[0x40 / 8] = save_desc_40;
 695         put_cpu();
 696         return error;
 697 }
 698 
 699 /**
 700  *      apm_bios_call_simple    -       make a simple APM BIOS 32bit call
 701  *      @func: APM function to invoke
 702  *      @ebx_in: EBX register value for BIOS call
 703  *      @ecx_in: ECX register value for BIOS call
 704  *      @eax: EAX register on return from the BIOS call
 705  *      @err: bits
 706  *
 707  *      Make a BIOS call that returns one value only, or just status.
 708  *      If there is an error, then the error code is returned in @err
 709  *      and this function returns non-zero. This is used for simpler
 710  *      BIOS operations.  This call may hold interrupts off for a long
 711  *      time on some laptops.
 712  */
 713 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
 714                                 int *err)
 715 {
 716         struct apm_bios_call call;
 717         int ret;
 718 
 719         call.func = func;
 720         call.ebx = ebx_in;
 721         call.ecx = ecx_in;
 722 
 723         ret = on_cpu0(__apm_bios_call_simple, &call);
 724         *eax = call.eax;
 725         *err = call.err;
 726         return ret;
 727 }
 728 
 729 /**
 730  *      apm_driver_version      -       APM driver version
 731  *      @val:   loaded with the APM version on return
 732  *
 733  *      Retrieve the APM version supported by the BIOS. This is only
 734  *      supported for APM 1.1 or higher. An error indicates APM 1.0 is
 735  *      probably present.
 736  *
 737  *      On entry val should point to a value indicating the APM driver
 738  *      version with the high byte being the major and the low byte the
 739  *      minor number both in BCD
 740  *
 741  *      On return it will hold the BIOS revision supported in the
 742  *      same format.
 743  */
 744 
 745 static int apm_driver_version(u_short *val)
 746 {
 747         u32 eax;
 748         int err;
 749 
 750         if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
 751                 return err;
 752         *val = eax;
 753         return APM_SUCCESS;
 754 }
 755 
 756 /**
 757  *      apm_get_event   -       get an APM event from the BIOS
 758  *      @event: pointer to the event
 759  *      @info: point to the event information
 760  *
 761  *      The APM BIOS provides a polled information for event
 762  *      reporting. The BIOS expects to be polled at least every second
 763  *      when events are pending. When a message is found the caller should
 764  *      poll until no more messages are present.  However, this causes
 765  *      problems on some laptops where a suspend event notification is
 766  *      not cleared until it is acknowledged.
 767  *
 768  *      Additional information is returned in the info pointer, providing
 769  *      that APM 1.2 is in use. If no messges are pending the value 0x80
 770  *      is returned (No power management events pending).
 771  */
 772 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
 773 {
 774         struct apm_bios_call call;
 775 
 776         call.func = APM_FUNC_GET_EVENT;
 777         call.ebx = call.ecx = 0;
 778 
 779         if (apm_bios_call(&call))
 780                 return call.err;
 781 
 782         *event = call.ebx;
 783         if (apm_info.connection_version < 0x0102)
 784                 *info = ~0; /* indicate info not valid */
 785         else
 786                 *info = call.ecx;
 787         return APM_SUCCESS;
 788 }
 789 
 790 /**
 791  *      set_power_state -       set the power management state
 792  *      @what: which items to transition
 793  *      @state: state to transition to
 794  *
 795  *      Request an APM change of state for one or more system devices. The
 796  *      processor state must be transitioned last of all. what holds the
 797  *      class of device in the upper byte and the device number (0xFF for
 798  *      all) for the object to be transitioned.
 799  *
 800  *      The state holds the state to transition to, which may in fact
 801  *      be an acceptance of a BIOS requested state change.
 802  */
 803 
 804 static int set_power_state(u_short what, u_short state)
 805 {
 806         u32 eax;
 807         int err;
 808 
 809         if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
 810                 return err;
 811         return APM_SUCCESS;
 812 }
 813 
 814 /**
 815  *      set_system_power_state - set system wide power state
 816  *      @state: which state to enter
 817  *
 818  *      Transition the entire system into a new APM power state.
 819  */
 820 
 821 static int set_system_power_state(u_short state)
 822 {
 823         return set_power_state(APM_DEVICE_ALL, state);
 824 }
 825 
 826 /**
 827  *      apm_do_idle     -       perform power saving
 828  *
 829  *      This function notifies the BIOS that the processor is (in the view
 830  *      of the OS) idle. It returns -1 in the event that the BIOS refuses
 831  *      to handle the idle request. On a success the function returns 1
 832  *      if the BIOS did clock slowing or 0 otherwise.
 833  */
 834 
 835 static int apm_do_idle(void)
 836 {
 837         u32 eax;
 838         u8 ret = 0;
 839         int idled = 0;
 840         int err = 0;
 841 
 842         if (!need_resched()) {
 843                 idled = 1;
 844                 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
 845         }
 846 
 847         if (!idled)
 848                 return 0;
 849 
 850         if (ret) {
 851                 static unsigned long t;
 852 
 853                 /* This always fails on some SMP boards running UP kernels.
 854                  * Only report the failure the first 5 times.
 855                  */
 856                 if (++t < 5) {
 857                         printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
 858                         t = jiffies;
 859                 }
 860                 return -1;
 861         }
 862         clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
 863         return clock_slowed;
 864 }
 865 
 866 /**
 867  *      apm_do_busy     -       inform the BIOS the CPU is busy
 868  *
 869  *      Request that the BIOS brings the CPU back to full performance.
 870  */
 871 
 872 static void apm_do_busy(void)
 873 {
 874         u32 dummy;
 875         int err;
 876 
 877         if (clock_slowed || ALWAYS_CALL_BUSY) {
 878                 (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
 879                 clock_slowed = 0;
 880         }
 881 }
 882 
 883 /*
 884  * If no process has really been interested in
 885  * the CPU for some time, we want to call BIOS
 886  * power management - we probably want
 887  * to conserve power.
 888  */
 889 #define IDLE_CALC_LIMIT (HZ * 100)
 890 #define IDLE_LEAKY_MAX  16
 891 
 892 /**
 893  * apm_cpu_idle         -       cpu idling for APM capable Linux
 894  *
 895  * This is the idling function the kernel executes when APM is available. It
 896  * tries to do BIOS powermanagement based on the average system idle time.
 897  * Furthermore it calls the system default idle routine.
 898  */
 899 
 900 static int apm_cpu_idle(struct cpuidle_device *dev,
 901         struct cpuidle_driver *drv, int index)
 902 {
 903         static int use_apm_idle; /* = 0 */
 904         static unsigned int last_jiffies; /* = 0 */
 905         static u64 last_stime; /* = 0 */
 906         u64 stime, utime;
 907 
 908         int apm_idle_done = 0;
 909         unsigned int jiffies_since_last_check = jiffies - last_jiffies;
 910         unsigned int bucket;
 911 
 912 recalc:
 913         task_cputime(current, &utime, &stime);
 914         if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
 915                 use_apm_idle = 0;
 916         } else if (jiffies_since_last_check > idle_period) {
 917                 unsigned int idle_percentage;
 918 
 919                 idle_percentage = nsecs_to_jiffies(stime - last_stime);
 920                 idle_percentage *= 100;
 921                 idle_percentage /= jiffies_since_last_check;
 922                 use_apm_idle = (idle_percentage > idle_threshold);
 923                 if (apm_info.forbid_idle)
 924                         use_apm_idle = 0;
 925         }
 926 
 927         last_jiffies = jiffies;
 928         last_stime = stime;
 929 
 930         bucket = IDLE_LEAKY_MAX;
 931 
 932         while (!need_resched()) {
 933                 if (use_apm_idle) {
 934                         unsigned int t;
 935 
 936                         t = jiffies;
 937                         switch (apm_do_idle()) {
 938                         case 0:
 939                                 apm_idle_done = 1;
 940                                 if (t != jiffies) {
 941                                         if (bucket) {
 942                                                 bucket = IDLE_LEAKY_MAX;
 943                                                 continue;
 944                                         }
 945                                 } else if (bucket) {
 946                                         bucket--;
 947                                         continue;
 948                                 }
 949                                 break;
 950                         case 1:
 951                                 apm_idle_done = 1;
 952                                 break;
 953                         default: /* BIOS refused */
 954                                 break;
 955                         }
 956                 }
 957                 default_idle();
 958                 local_irq_disable();
 959                 jiffies_since_last_check = jiffies - last_jiffies;
 960                 if (jiffies_since_last_check > idle_period)
 961                         goto recalc;
 962         }
 963 
 964         if (apm_idle_done)
 965                 apm_do_busy();
 966 
 967         return index;
 968 }
 969 
 970 /**
 971  *      apm_power_off   -       ask the BIOS to power off
 972  *
 973  *      Handle the power off sequence. This is the one piece of code we
 974  *      will execute even on SMP machines. In order to deal with BIOS
 975  *      bugs we support real mode APM BIOS power off calls. We also make
 976  *      the SMP call on CPU0 as some systems will only honour this call
 977  *      on their first cpu.
 978  */
 979 
 980 static void apm_power_off(void)
 981 {
 982         /* Some bioses don't like being called from CPU != 0 */
 983         if (apm_info.realmode_power_off) {
 984                 set_cpus_allowed_ptr(current, cpumask_of(0));
 985                 machine_real_restart(MRR_APM);
 986         } else {
 987                 (void)set_system_power_state(APM_STATE_OFF);
 988         }
 989 }
 990 
 991 #ifdef CONFIG_APM_DO_ENABLE
 992 
 993 /**
 994  *      apm_enable_power_management - enable BIOS APM power management
 995  *      @enable: enable yes/no
 996  *
 997  *      Enable or disable the APM BIOS power services.
 998  */
 999 
1000 static int apm_enable_power_management(int enable)
1001 {
1002         u32 eax;
1003         int err;
1004 
1005         if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1006                 return APM_NOT_ENGAGED;
1007         if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1008                                  enable, &eax, &err))
1009                 return err;
1010         if (enable)
1011                 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1012         else
1013                 apm_info.bios.flags |= APM_BIOS_DISABLED;
1014         return APM_SUCCESS;
1015 }
1016 #endif
1017 
1018 /**
1019  *      apm_get_power_status    -       get current power state
1020  *      @status: returned status
1021  *      @bat: battery info
1022  *      @life: estimated life
1023  *
1024  *      Obtain the current power status from the APM BIOS. We return a
1025  *      status which gives the rough battery status, and current power
1026  *      source. The bat value returned give an estimate as a percentage
1027  *      of life and a status value for the battery. The estimated life
1028  *      if reported is a lifetime in secodnds/minutes at current powwer
1029  *      consumption.
1030  */
1031 
1032 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1033 {
1034         struct apm_bios_call call;
1035 
1036         call.func = APM_FUNC_GET_STATUS;
1037         call.ebx = APM_DEVICE_ALL;
1038         call.ecx = 0;
1039 
1040         if (apm_info.get_power_status_broken)
1041                 return APM_32_UNSUPPORTED;
1042         if (apm_bios_call(&call)) {
1043                 if (!call.err)
1044                         return APM_NO_ERROR;
1045                 return call.err;
1046         }
1047         *status = call.ebx;
1048         *bat = call.ecx;
1049         if (apm_info.get_power_status_swabinminutes) {
1050                 *life = swab16((u16)call.edx);
1051                 *life |= 0x8000;
1052         } else
1053                 *life = call.edx;
1054         return APM_SUCCESS;
1055 }
1056 
1057 #if 0
1058 static int apm_get_battery_status(u_short which, u_short *status,
1059                                   u_short *bat, u_short *life, u_short *nbat)
1060 {
1061         u32 eax;
1062         u32 ebx;
1063         u32 ecx;
1064         u32 edx;
1065         u32 esi;
1066 
1067         if (apm_info.connection_version < 0x0102) {
1068                 /* pretend we only have one battery. */
1069                 if (which != 1)
1070                         return APM_BAD_DEVICE;
1071                 *nbat = 1;
1072                 return apm_get_power_status(status, bat, life);
1073         }
1074 
1075         if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1076                           &ebx, &ecx, &edx, &esi))
1077                 return (eax >> 8) & 0xff;
1078         *status = ebx;
1079         *bat = ecx;
1080         *life = edx;
1081         *nbat = esi;
1082         return APM_SUCCESS;
1083 }
1084 #endif
1085 
1086 /**
1087  *      apm_engage_power_management     -       enable PM on a device
1088  *      @device: identity of device
1089  *      @enable: on/off
1090  *
1091  *      Activate or deactivate power management on either a specific device
1092  *      or the entire system (%APM_DEVICE_ALL).
1093  */
1094 
1095 static int apm_engage_power_management(u_short device, int enable)
1096 {
1097         u32 eax;
1098         int err;
1099 
1100         if ((enable == 0) && (device == APM_DEVICE_ALL)
1101             && (apm_info.bios.flags & APM_BIOS_DISABLED))
1102                 return APM_DISABLED;
1103         if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1104                                  &eax, &err))
1105                 return err;
1106         if (device == APM_DEVICE_ALL) {
1107                 if (enable)
1108                         apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1109                 else
1110                         apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1111         }
1112         return APM_SUCCESS;
1113 }
1114 
1115 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1116 
1117 /**
1118  *      apm_console_blank       -       blank the display
1119  *      @blank: on/off
1120  *
1121  *      Attempt to blank the console, firstly by blanking just video device
1122  *      zero, and if that fails (some BIOSes don't support it) then it blanks
1123  *      all video devices. Typically the BIOS will do laptop backlight and
1124  *      monitor powerdown for us.
1125  */
1126 
1127 static int apm_console_blank(int blank)
1128 {
1129         int error = APM_NOT_ENGAGED; /* silence gcc */
1130         int i;
1131         u_short state;
1132         static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1133 
1134         state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1135 
1136         for (i = 0; i < ARRAY_SIZE(dev); i++) {
1137                 error = set_power_state(dev[i], state);
1138 
1139                 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1140                         return 1;
1141 
1142                 if (error == APM_NOT_ENGAGED)
1143                         break;
1144         }
1145 
1146         if (error == APM_NOT_ENGAGED) {
1147                 static int tried;
1148                 int eng_error;
1149                 if (tried++ == 0) {
1150                         eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1151                         if (eng_error) {
1152                                 apm_error("set display", error);
1153                                 apm_error("engage interface", eng_error);
1154                                 return 0;
1155                         } else
1156                                 return apm_console_blank(blank);
1157                 }
1158         }
1159         apm_error("set display", error);
1160         return 0;
1161 }
1162 #endif
1163 
1164 static int queue_empty(struct apm_user *as)
1165 {
1166         return as->event_head == as->event_tail;
1167 }
1168 
1169 static apm_event_t get_queued_event(struct apm_user *as)
1170 {
1171         if (++as->event_tail >= APM_MAX_EVENTS)
1172                 as->event_tail = 0;
1173         return as->events[as->event_tail];
1174 }
1175 
1176 static void queue_event(apm_event_t event, struct apm_user *sender)
1177 {
1178         struct apm_user *as;
1179 
1180         spin_lock(&user_list_lock);
1181         if (user_list == NULL)
1182                 goto out;
1183         for (as = user_list; as != NULL; as = as->next) {
1184                 if ((as == sender) || (!as->reader))
1185                         continue;
1186                 if (++as->event_head >= APM_MAX_EVENTS)
1187                         as->event_head = 0;
1188 
1189                 if (as->event_head == as->event_tail) {
1190                         static int notified;
1191 
1192                         if (notified++ == 0)
1193                                 pr_err("an event queue overflowed\n");
1194                         if (++as->event_tail >= APM_MAX_EVENTS)
1195                                 as->event_tail = 0;
1196                 }
1197                 as->events[as->event_head] = event;
1198                 if (!as->suser || !as->writer)
1199                         continue;
1200                 switch (event) {
1201                 case APM_SYS_SUSPEND:
1202                 case APM_USER_SUSPEND:
1203                         as->suspends_pending++;
1204                         suspends_pending++;
1205                         break;
1206 
1207                 case APM_SYS_STANDBY:
1208                 case APM_USER_STANDBY:
1209                         as->standbys_pending++;
1210                         standbys_pending++;
1211                         break;
1212                 }
1213         }
1214         wake_up_interruptible(&apm_waitqueue);
1215 out:
1216         spin_unlock(&user_list_lock);
1217 }
1218 
1219 static void reinit_timer(void)
1220 {
1221 #ifdef INIT_TIMER_AFTER_SUSPEND
1222         unsigned long flags;
1223 
1224         raw_spin_lock_irqsave(&i8253_lock, flags);
1225         /* set the clock to HZ */
1226         outb_p(0x34, PIT_MODE);         /* binary, mode 2, LSB/MSB, ch 0 */
1227         udelay(10);
1228         outb_p(LATCH & 0xff, PIT_CH0);  /* LSB */
1229         udelay(10);
1230         outb_p(LATCH >> 8, PIT_CH0);    /* MSB */
1231         udelay(10);
1232         raw_spin_unlock_irqrestore(&i8253_lock, flags);
1233 #endif
1234 }
1235 
1236 static int suspend(int vetoable)
1237 {
1238         int err;
1239         struct apm_user *as;
1240 
1241         dpm_suspend_start(PMSG_SUSPEND);
1242         dpm_suspend_end(PMSG_SUSPEND);
1243 
1244         local_irq_disable();
1245         syscore_suspend();
1246 
1247         local_irq_enable();
1248 
1249         save_processor_state();
1250         err = set_system_power_state(APM_STATE_SUSPEND);
1251         ignore_normal_resume = 1;
1252         restore_processor_state();
1253 
1254         local_irq_disable();
1255         reinit_timer();
1256 
1257         if (err == APM_NO_ERROR)
1258                 err = APM_SUCCESS;
1259         if (err != APM_SUCCESS)
1260                 apm_error("suspend", err);
1261         err = (err == APM_SUCCESS) ? 0 : -EIO;
1262 
1263         syscore_resume();
1264         local_irq_enable();
1265 
1266         dpm_resume_start(PMSG_RESUME);
1267         dpm_resume_end(PMSG_RESUME);
1268 
1269         queue_event(APM_NORMAL_RESUME, NULL);
1270         spin_lock(&user_list_lock);
1271         for (as = user_list; as != NULL; as = as->next) {
1272                 as->suspend_wait = 0;
1273                 as->suspend_result = err;
1274         }
1275         spin_unlock(&user_list_lock);
1276         wake_up_interruptible(&apm_suspend_waitqueue);
1277         return err;
1278 }
1279 
1280 static void standby(void)
1281 {
1282         int err;
1283 
1284         dpm_suspend_end(PMSG_SUSPEND);
1285 
1286         local_irq_disable();
1287         syscore_suspend();
1288         local_irq_enable();
1289 
1290         err = set_system_power_state(APM_STATE_STANDBY);
1291         if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1292                 apm_error("standby", err);
1293 
1294         local_irq_disable();
1295         syscore_resume();
1296         local_irq_enable();
1297 
1298         dpm_resume_start(PMSG_RESUME);
1299 }
1300 
1301 static apm_event_t get_event(void)
1302 {
1303         int error;
1304         apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1305         apm_eventinfo_t info;
1306 
1307         static int notified;
1308 
1309         /* we don't use the eventinfo */
1310         error = apm_get_event(&event, &info);
1311         if (error == APM_SUCCESS)
1312                 return event;
1313 
1314         if ((error != APM_NO_EVENTS) && (notified++ == 0))
1315                 apm_error("get_event", error);
1316 
1317         return 0;
1318 }
1319 
1320 static void check_events(void)
1321 {
1322         apm_event_t event;
1323         static unsigned long last_resume;
1324         static int ignore_bounce;
1325 
1326         while ((event = get_event()) != 0) {
1327                 if (debug) {
1328                         if (event <= NR_APM_EVENT_NAME)
1329                                 printk(KERN_DEBUG "apm: received %s notify\n",
1330                                        apm_event_name[event - 1]);
1331                         else
1332                                 printk(KERN_DEBUG "apm: received unknown "
1333                                        "event 0x%02x\n", event);
1334                 }
1335                 if (ignore_bounce
1336                     && (time_after(jiffies, last_resume + bounce_interval)))
1337                         ignore_bounce = 0;
1338 
1339                 switch (event) {
1340                 case APM_SYS_STANDBY:
1341                 case APM_USER_STANDBY:
1342                         queue_event(event, NULL);
1343                         if (standbys_pending <= 0)
1344                                 standby();
1345                         break;
1346 
1347                 case APM_USER_SUSPEND:
1348 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1349                         if (apm_info.connection_version > 0x100)
1350                                 set_system_power_state(APM_STATE_REJECT);
1351                         break;
1352 #endif
1353                 case APM_SYS_SUSPEND:
1354                         if (ignore_bounce) {
1355                                 if (apm_info.connection_version > 0x100)
1356                                         set_system_power_state(APM_STATE_REJECT);
1357                                 break;
1358                         }
1359                         /*
1360                          * If we are already processing a SUSPEND,
1361                          * then further SUSPEND events from the BIOS
1362                          * will be ignored.  We also return here to
1363                          * cope with the fact that the Thinkpads keep
1364                          * sending a SUSPEND event until something else
1365                          * happens!
1366                          */
1367                         if (ignore_sys_suspend)
1368                                 return;
1369                         ignore_sys_suspend = 1;
1370                         queue_event(event, NULL);
1371                         if (suspends_pending <= 0)
1372                                 (void) suspend(1);
1373                         break;
1374 
1375                 case APM_NORMAL_RESUME:
1376                 case APM_CRITICAL_RESUME:
1377                 case APM_STANDBY_RESUME:
1378                         ignore_sys_suspend = 0;
1379                         last_resume = jiffies;
1380                         ignore_bounce = 1;
1381                         if ((event != APM_NORMAL_RESUME)
1382                             || (ignore_normal_resume == 0)) {
1383                                 dpm_resume_end(PMSG_RESUME);
1384                                 queue_event(event, NULL);
1385                         }
1386                         ignore_normal_resume = 0;
1387                         break;
1388 
1389                 case APM_CAPABILITY_CHANGE:
1390                 case APM_LOW_BATTERY:
1391                 case APM_POWER_STATUS_CHANGE:
1392                         queue_event(event, NULL);
1393                         /* If needed, notify drivers here */
1394                         break;
1395 
1396                 case APM_UPDATE_TIME:
1397                         break;
1398 
1399                 case APM_CRITICAL_SUSPEND:
1400                         /*
1401                          * We are not allowed to reject a critical suspend.
1402                          */
1403                         (void)suspend(0);
1404                         break;
1405                 }
1406         }
1407 }
1408 
1409 static void apm_event_handler(void)
1410 {
1411         static int pending_count = 4;
1412         int err;
1413 
1414         if ((standbys_pending > 0) || (suspends_pending > 0)) {
1415                 if ((apm_info.connection_version > 0x100) &&
1416                     (pending_count-- <= 0)) {
1417                         pending_count = 4;
1418                         if (debug)
1419                                 printk(KERN_DEBUG "apm: setting state busy\n");
1420                         err = set_system_power_state(APM_STATE_BUSY);
1421                         if (err)
1422                                 apm_error("busy", err);
1423                 }
1424         } else
1425                 pending_count = 4;
1426         check_events();
1427 }
1428 
1429 /*
1430  * This is the APM thread main loop.
1431  */
1432 
1433 static void apm_mainloop(void)
1434 {
1435         DECLARE_WAITQUEUE(wait, current);
1436 
1437         add_wait_queue(&apm_waitqueue, &wait);
1438         set_current_state(TASK_INTERRUPTIBLE);
1439         for (;;) {
1440                 schedule_timeout(APM_CHECK_TIMEOUT);
1441                 if (kthread_should_stop())
1442                         break;
1443                 /*
1444                  * Ok, check all events, check for idle (and mark us sleeping
1445                  * so as not to count towards the load average)..
1446                  */
1447                 set_current_state(TASK_INTERRUPTIBLE);
1448                 apm_event_handler();
1449         }
1450         remove_wait_queue(&apm_waitqueue, &wait);
1451 }
1452 
1453 static int check_apm_user(struct apm_user *as, const char *func)
1454 {
1455         if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1456                 pr_err("%s passed bad filp\n", func);
1457                 return 1;
1458         }
1459         return 0;
1460 }
1461 
1462 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1463 {
1464         struct apm_user *as;
1465         int i;
1466         apm_event_t event;
1467 
1468         as = fp->private_data;
1469         if (check_apm_user(as, "read"))
1470                 return -EIO;
1471         if ((int)count < sizeof(apm_event_t))
1472                 return -EINVAL;
1473         if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1474                 return -EAGAIN;
1475         wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1476         i = count;
1477         while ((i >= sizeof(event)) && !queue_empty(as)) {
1478                 event = get_queued_event(as);
1479                 if (copy_to_user(buf, &event, sizeof(event))) {
1480                         if (i < count)
1481                                 break;
1482                         return -EFAULT;
1483                 }
1484                 switch (event) {
1485                 case APM_SYS_SUSPEND:
1486                 case APM_USER_SUSPEND:
1487                         as->suspends_read++;
1488                         break;
1489 
1490                 case APM_SYS_STANDBY:
1491                 case APM_USER_STANDBY:
1492                         as->standbys_read++;
1493                         break;
1494                 }
1495                 buf += sizeof(event);
1496                 i -= sizeof(event);
1497         }
1498         if (i < count)
1499                 return count - i;
1500         if (signal_pending(current))
1501                 return -ERESTARTSYS;
1502         return 0;
1503 }
1504 
1505 static __poll_t do_poll(struct file *fp, poll_table *wait)
1506 {
1507         struct apm_user *as;
1508 
1509         as = fp->private_data;
1510         if (check_apm_user(as, "poll"))
1511                 return 0;
1512         poll_wait(fp, &apm_waitqueue, wait);
1513         if (!queue_empty(as))
1514                 return EPOLLIN | EPOLLRDNORM;
1515         return 0;
1516 }
1517 
1518 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1519 {
1520         struct apm_user *as;
1521         int ret;
1522 
1523         as = filp->private_data;
1524         if (check_apm_user(as, "ioctl"))
1525                 return -EIO;
1526         if (!as->suser || !as->writer)
1527                 return -EPERM;
1528         switch (cmd) {
1529         case APM_IOC_STANDBY:
1530                 mutex_lock(&apm_mutex);
1531                 if (as->standbys_read > 0) {
1532                         as->standbys_read--;
1533                         as->standbys_pending--;
1534                         standbys_pending--;
1535                 } else
1536                         queue_event(APM_USER_STANDBY, as);
1537                 if (standbys_pending <= 0)
1538                         standby();
1539                 mutex_unlock(&apm_mutex);
1540                 break;
1541         case APM_IOC_SUSPEND:
1542                 mutex_lock(&apm_mutex);
1543                 if (as->suspends_read > 0) {
1544                         as->suspends_read--;
1545                         as->suspends_pending--;
1546                         suspends_pending--;
1547                 } else
1548                         queue_event(APM_USER_SUSPEND, as);
1549                 if (suspends_pending <= 0) {
1550                         ret = suspend(1);
1551                         mutex_unlock(&apm_mutex);
1552                 } else {
1553                         as->suspend_wait = 1;
1554                         mutex_unlock(&apm_mutex);
1555                         wait_event_interruptible(apm_suspend_waitqueue,
1556                                         as->suspend_wait == 0);
1557                         ret = as->suspend_result;
1558                 }
1559                 return ret;
1560         default:
1561                 return -ENOTTY;
1562         }
1563         return 0;
1564 }
1565 
1566 static int do_release(struct inode *inode, struct file *filp)
1567 {
1568         struct apm_user *as;
1569 
1570         as = filp->private_data;
1571         if (check_apm_user(as, "release"))
1572                 return 0;
1573         filp->private_data = NULL;
1574         if (as->standbys_pending > 0) {
1575                 standbys_pending -= as->standbys_pending;
1576                 if (standbys_pending <= 0)
1577                         standby();
1578         }
1579         if (as->suspends_pending > 0) {
1580                 suspends_pending -= as->suspends_pending;
1581                 if (suspends_pending <= 0)
1582                         (void) suspend(1);
1583         }
1584         spin_lock(&user_list_lock);
1585         if (user_list == as)
1586                 user_list = as->next;
1587         else {
1588                 struct apm_user *as1;
1589 
1590                 for (as1 = user_list;
1591                      (as1 != NULL) && (as1->next != as);
1592                      as1 = as1->next)
1593                         ;
1594                 if (as1 == NULL)
1595                         pr_err("filp not in user list\n");
1596                 else
1597                         as1->next = as->next;
1598         }
1599         spin_unlock(&user_list_lock);
1600         kfree(as);
1601         return 0;
1602 }
1603 
1604 static int do_open(struct inode *inode, struct file *filp)
1605 {
1606         struct apm_user *as;
1607 
1608         as = kmalloc(sizeof(*as), GFP_KERNEL);
1609         if (as == NULL)
1610                 return -ENOMEM;
1611 
1612         as->magic = APM_BIOS_MAGIC;
1613         as->event_tail = as->event_head = 0;
1614         as->suspends_pending = as->standbys_pending = 0;
1615         as->suspends_read = as->standbys_read = 0;
1616         /*
1617          * XXX - this is a tiny bit broken, when we consider BSD
1618          * process accounting. If the device is opened by root, we
1619          * instantly flag that we used superuser privs. Who knows,
1620          * we might close the device immediately without doing a
1621          * privileged operation -- cevans
1622          */
1623         as->suser = capable(CAP_SYS_ADMIN);
1624         as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1625         as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1626         spin_lock(&user_list_lock);
1627         as->next = user_list;
1628         user_list = as;
1629         spin_unlock(&user_list_lock);
1630         filp->private_data = as;
1631         return 0;
1632 }
1633 
1634 #ifdef CONFIG_PROC_FS
1635 static int proc_apm_show(struct seq_file *m, void *v)
1636 {
1637         unsigned short  bx;
1638         unsigned short  cx;
1639         unsigned short  dx;
1640         int             error;
1641         unsigned short  ac_line_status = 0xff;
1642         unsigned short  battery_status = 0xff;
1643         unsigned short  battery_flag   = 0xff;
1644         int             percentage     = -1;
1645         int             time_units     = -1;
1646         char            *units         = "?";
1647 
1648         if ((num_online_cpus() == 1) &&
1649             !(error = apm_get_power_status(&bx, &cx, &dx))) {
1650                 ac_line_status = (bx >> 8) & 0xff;
1651                 battery_status = bx & 0xff;
1652                 if ((cx & 0xff) != 0xff)
1653                         percentage = cx & 0xff;
1654 
1655                 if (apm_info.connection_version > 0x100) {
1656                         battery_flag = (cx >> 8) & 0xff;
1657                         if (dx != 0xffff) {
1658                                 units = (dx & 0x8000) ? "min" : "sec";
1659                                 time_units = dx & 0x7fff;
1660                         }
1661                 }
1662         }
1663         /* Arguments, with symbols from linux/apm_bios.h.  Information is
1664            from the Get Power Status (0x0a) call unless otherwise noted.
1665 
1666            0) Linux driver version (this will change if format changes)
1667            1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1668            2) APM flags from APM Installation Check (0x00):
1669               bit 0: APM_16_BIT_SUPPORT
1670               bit 1: APM_32_BIT_SUPPORT
1671               bit 2: APM_IDLE_SLOWS_CLOCK
1672               bit 3: APM_BIOS_DISABLED
1673               bit 4: APM_BIOS_DISENGAGED
1674            3) AC line status
1675               0x00: Off-line
1676               0x01: On-line
1677               0x02: On backup power (BIOS >= 1.1 only)
1678               0xff: Unknown
1679            4) Battery status
1680               0x00: High
1681               0x01: Low
1682               0x02: Critical
1683               0x03: Charging
1684               0x04: Selected battery not present (BIOS >= 1.2 only)
1685               0xff: Unknown
1686            5) Battery flag
1687               bit 0: High
1688               bit 1: Low
1689               bit 2: Critical
1690               bit 3: Charging
1691               bit 7: No system battery
1692               0xff: Unknown
1693            6) Remaining battery life (percentage of charge):
1694               0-100: valid
1695               -1: Unknown
1696            7) Remaining battery life (time units):
1697               Number of remaining minutes or seconds
1698               -1: Unknown
1699            8) min = minutes; sec = seconds */
1700 
1701         seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1702                    driver_version,
1703                    (apm_info.bios.version >> 8) & 0xff,
1704                    apm_info.bios.version & 0xff,
1705                    apm_info.bios.flags,
1706                    ac_line_status,
1707                    battery_status,
1708                    battery_flag,
1709                    percentage,
1710                    time_units,
1711                    units);
1712         return 0;
1713 }
1714 #endif
1715 
1716 static int apm(void *unused)
1717 {
1718         unsigned short  bx;
1719         unsigned short  cx;
1720         unsigned short  dx;
1721         int             error;
1722         char            *power_stat;
1723         char            *bat_stat;
1724 
1725         /* 2002/08/01 - WT
1726          * This is to avoid random crashes at boot time during initialization
1727          * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1728          * Some bioses don't like being called from CPU != 0.
1729          * Method suggested by Ingo Molnar.
1730          */
1731         set_cpus_allowed_ptr(current, cpumask_of(0));
1732         BUG_ON(smp_processor_id() != 0);
1733 
1734         if (apm_info.connection_version == 0) {
1735                 apm_info.connection_version = apm_info.bios.version;
1736                 if (apm_info.connection_version > 0x100) {
1737                         /*
1738                          * We only support BIOSs up to version 1.2
1739                          */
1740                         if (apm_info.connection_version > 0x0102)
1741                                 apm_info.connection_version = 0x0102;
1742                         error = apm_driver_version(&apm_info.connection_version);
1743                         if (error != APM_SUCCESS) {
1744                                 apm_error("driver version", error);
1745                                 /* Fall back to an APM 1.0 connection. */
1746                                 apm_info.connection_version = 0x100;
1747                         }
1748                 }
1749         }
1750 
1751         if (debug)
1752                 printk(KERN_INFO "apm: Connection version %d.%d\n",
1753                         (apm_info.connection_version >> 8) & 0xff,
1754                         apm_info.connection_version & 0xff);
1755 
1756 #ifdef CONFIG_APM_DO_ENABLE
1757         if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1758                 /*
1759                  * This call causes my NEC UltraLite Versa 33/C to hang if it
1760                  * is booted with PM disabled but not in the docking station.
1761                  * Unfortunate ...
1762                  */
1763                 error = apm_enable_power_management(1);
1764                 if (error) {
1765                         apm_error("enable power management", error);
1766                         return -1;
1767                 }
1768         }
1769 #endif
1770 
1771         if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1772             && (apm_info.connection_version > 0x0100)) {
1773                 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1774                 if (error) {
1775                         apm_error("engage power management", error);
1776                         return -1;
1777                 }
1778         }
1779 
1780         if (debug && (num_online_cpus() == 1 || smp)) {
1781                 error = apm_get_power_status(&bx, &cx, &dx);
1782                 if (error)
1783                         printk(KERN_INFO "apm: power status not available\n");
1784                 else {
1785                         switch ((bx >> 8) & 0xff) {
1786                         case 0:
1787                                 power_stat = "off line";
1788                                 break;
1789                         case 1:
1790                                 power_stat = "on line";
1791                                 break;
1792                         case 2:
1793                                 power_stat = "on backup power";
1794                                 break;
1795                         default:
1796                                 power_stat = "unknown";
1797                                 break;
1798                         }
1799                         switch (bx & 0xff) {
1800                         case 0:
1801                                 bat_stat = "high";
1802                                 break;
1803                         case 1:
1804                                 bat_stat = "low";
1805                                 break;
1806                         case 2:
1807                                 bat_stat = "critical";
1808                                 break;
1809                         case 3:
1810                                 bat_stat = "charging";
1811                                 break;
1812                         default:
1813                                 bat_stat = "unknown";
1814                                 break;
1815                         }
1816                         printk(KERN_INFO
1817                                "apm: AC %s, battery status %s, battery life ",
1818                                power_stat, bat_stat);
1819                         if ((cx & 0xff) == 0xff)
1820                                 printk("unknown\n");
1821                         else
1822                                 printk("%d%%\n", cx & 0xff);
1823                         if (apm_info.connection_version > 0x100) {
1824                                 printk(KERN_INFO
1825                                        "apm: battery flag 0x%02x, battery life ",
1826                                        (cx >> 8) & 0xff);
1827                                 if (dx == 0xffff)
1828                                         printk("unknown\n");
1829                                 else
1830                                         printk("%d %s\n", dx & 0x7fff,
1831                                                (dx & 0x8000) ?
1832                                                "minutes" : "seconds");
1833                         }
1834                 }
1835         }
1836 
1837         /* Install our power off handler.. */
1838         if (power_off)
1839                 pm_power_off = apm_power_off;
1840 
1841         if (num_online_cpus() == 1 || smp) {
1842 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1843                 console_blank_hook = apm_console_blank;
1844 #endif
1845                 apm_mainloop();
1846 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1847                 console_blank_hook = NULL;
1848 #endif
1849         }
1850 
1851         return 0;
1852 }
1853 
1854 #ifndef MODULE
1855 static int __init apm_setup(char *str)
1856 {
1857         int invert;
1858 
1859         while ((str != NULL) && (*str != '\0')) {
1860                 if (strncmp(str, "off", 3) == 0)
1861                         apm_disabled = 1;
1862                 if (strncmp(str, "on", 2) == 0)
1863                         apm_disabled = 0;
1864                 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1865                     (strncmp(str, "bounce_interval=", 16) == 0))
1866                         bounce_interval = simple_strtol(str + 16, NULL, 0);
1867                 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1868                     (strncmp(str, "idle_threshold=", 15) == 0))
1869                         idle_threshold = simple_strtol(str + 15, NULL, 0);
1870                 if ((strncmp(str, "idle-period=", 12) == 0) ||
1871                     (strncmp(str, "idle_period=", 12) == 0))
1872                         idle_period = simple_strtol(str + 12, NULL, 0);
1873                 invert = (strncmp(str, "no-", 3) == 0) ||
1874                         (strncmp(str, "no_", 3) == 0);
1875                 if (invert)
1876                         str += 3;
1877                 if (strncmp(str, "debug", 5) == 0)
1878                         debug = !invert;
1879                 if ((strncmp(str, "power-off", 9) == 0) ||
1880                     (strncmp(str, "power_off", 9) == 0))
1881                         power_off = !invert;
1882                 if (strncmp(str, "smp", 3) == 0) {
1883                         smp = !invert;
1884                         idle_threshold = 100;
1885                 }
1886                 if ((strncmp(str, "allow-ints", 10) == 0) ||
1887                     (strncmp(str, "allow_ints", 10) == 0))
1888                         apm_info.allow_ints = !invert;
1889                 if ((strncmp(str, "broken-psr", 10) == 0) ||
1890                     (strncmp(str, "broken_psr", 10) == 0))
1891                         apm_info.get_power_status_broken = !invert;
1892                 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1893                     (strncmp(str, "realmode_power_off", 18) == 0))
1894                         apm_info.realmode_power_off = !invert;
1895                 str = strchr(str, ',');
1896                 if (str != NULL)
1897                         str += strspn(str, ", \t");
1898         }
1899         return 1;
1900 }
1901 
1902 __setup("apm=", apm_setup);
1903 #endif
1904 
1905 static const struct file_operations apm_bios_fops = {
1906         .owner          = THIS_MODULE,
1907         .read           = do_read,
1908         .poll           = do_poll,
1909         .unlocked_ioctl = do_ioctl,
1910         .open           = do_open,
1911         .release        = do_release,
1912         .llseek         = noop_llseek,
1913 };
1914 
1915 static struct miscdevice apm_device = {
1916         APM_MINOR_DEV,
1917         "apm_bios",
1918         &apm_bios_fops
1919 };
1920 
1921 
1922 /* Simple "print if true" callback */
1923 static int __init print_if_true(const struct dmi_system_id *d)
1924 {
1925         printk("%s\n", d->ident);
1926         return 0;
1927 }
1928 
1929 /*
1930  * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1931  * disabled before the suspend. Linux used to get terribly confused by that.
1932  */
1933 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1934 {
1935         printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1936                "workaround hopefully not needed.\n", d->ident);
1937         return 0;
1938 }
1939 
1940 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1941 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1942 {
1943         if (apm_info.realmode_power_off == 0) {
1944                 apm_info.realmode_power_off = 1;
1945                 printk(KERN_INFO "%s bios detected. "
1946                        "Using realmode poweroff only.\n", d->ident);
1947         }
1948         return 0;
1949 }
1950 
1951 /* Some laptops require interrupts to be enabled during APM calls */
1952 static int __init set_apm_ints(const struct dmi_system_id *d)
1953 {
1954         if (apm_info.allow_ints == 0) {
1955                 apm_info.allow_ints = 1;
1956                 printk(KERN_INFO "%s machine detected. "
1957                        "Enabling interrupts during APM calls.\n", d->ident);
1958         }
1959         return 0;
1960 }
1961 
1962 /* Some APM bioses corrupt memory or just plain do not work */
1963 static int __init apm_is_horked(const struct dmi_system_id *d)
1964 {
1965         if (apm_info.disabled == 0) {
1966                 apm_info.disabled = 1;
1967                 printk(KERN_INFO "%s machine detected. "
1968                        "Disabling APM.\n", d->ident);
1969         }
1970         return 0;
1971 }
1972 
1973 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1974 {
1975         if (apm_info.disabled == 0) {
1976                 apm_info.disabled = 1;
1977                 printk(KERN_INFO "%s machine detected. "
1978                        "Disabling APM.\n", d->ident);
1979                 printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1980                 printk(KERN_INFO "download from support.intel.com\n");
1981         }
1982         return 0;
1983 }
1984 
1985 /* Some APM bioses hang on APM idle calls */
1986 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1987 {
1988         if (apm_info.forbid_idle == 0) {
1989                 apm_info.forbid_idle = 1;
1990                 printk(KERN_INFO "%s machine detected. "
1991                        "Disabling APM idle calls.\n", d->ident);
1992         }
1993         return 0;
1994 }
1995 
1996 /*
1997  *  Check for clue free BIOS implementations who use
1998  *  the following QA technique
1999  *
2000  *      [ Write BIOS Code ]<------
2001  *               |                ^
2002  *      < Does it Compile >----N--
2003  *               |Y               ^
2004  *      < Does it Boot Win98 >-N--
2005  *               |Y
2006  *           [Ship It]
2007  *
2008  *      Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2009  *      Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2010  */
2011 static int __init broken_apm_power(const struct dmi_system_id *d)
2012 {
2013         apm_info.get_power_status_broken = 1;
2014         printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2015                "disabling power status reporting.\n");
2016         return 0;
2017 }
2018 
2019 /*
2020  * This bios swaps the APM minute reporting bytes over (Many sony laptops
2021  * have this problem).
2022  */
2023 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2024 {
2025         apm_info.get_power_status_swabinminutes = 1;
2026         printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2027                "in minutes and wrong byte order.\n");
2028         return 0;
2029 }
2030 
2031 static const struct dmi_system_id apm_dmi_table[] __initconst = {
2032         {
2033                 print_if_true,
2034                 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2035                 {       DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2036                         DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2037         },
2038         {       /* Handle problems with APM on the C600 */
2039                 broken_ps2_resume, "Dell Latitude C600",
2040                 {       DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2041                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2042         },
2043         {       /* Allow interrupts during suspend on Dell Latitude laptops*/
2044                 set_apm_ints, "Dell Latitude",
2045                 {       DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2046                         DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2047         },
2048         {       /* APM crashes */
2049                 apm_is_horked, "Dell Inspiron 2500",
2050                 {       DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2051                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2052                         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2053                         DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2054         },
2055         {       /* Allow interrupts during suspend on Dell Inspiron laptops*/
2056                 set_apm_ints, "Dell Inspiron", {
2057                         DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2058                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2059         },
2060         {       /* Handle problems with APM on Inspiron 5000e */
2061                 broken_apm_power, "Dell Inspiron 5000e",
2062                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2063                         DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2064                         DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2065         },
2066         {       /* Handle problems with APM on Inspiron 2500 */
2067                 broken_apm_power, "Dell Inspiron 2500",
2068                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2069                         DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2070                         DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2071         },
2072         {       /* APM crashes */
2073                 apm_is_horked, "Dell Dimension 4100",
2074                 {       DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2075                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2076                         DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2077                         DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2078         },
2079         {       /* Allow interrupts during suspend on Compaq Laptops*/
2080                 set_apm_ints, "Compaq 12XL125",
2081                 {       DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2082                         DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2083                         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2084                         DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2085         },
2086         {       /* Allow interrupts during APM or the clock goes slow */
2087                 set_apm_ints, "ASUSTeK",
2088                 {       DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2089                         DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2090         },
2091         {       /* APM blows on shutdown */
2092                 apm_is_horked, "ABIT KX7-333[R]",
2093                 {       DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2094                         DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2095         },
2096         {       /* APM crashes */
2097                 apm_is_horked, "Trigem Delhi3",
2098                 {       DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2099                         DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2100         },
2101         {       /* APM crashes */
2102                 apm_is_horked, "Fujitsu-Siemens",
2103                 {       DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2104                         DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2105         },
2106         {       /* APM crashes */
2107                 apm_is_horked_d850md, "Intel D850MD",
2108                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2109                         DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2110         },
2111         {       /* APM crashes */
2112                 apm_is_horked, "Intel D810EMO",
2113                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2114                         DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2115         },
2116         {       /* APM crashes */
2117                 apm_is_horked, "Dell XPS-Z",
2118                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2119                         DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2120                         DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2121         },
2122         {       /* APM crashes */
2123                 apm_is_horked, "Sharp PC-PJ/AX",
2124                 {       DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2125                         DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2126                         DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2127                         DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2128         },
2129         {       /* APM crashes */
2130                 apm_is_horked, "Dell Inspiron 2500",
2131                 {       DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2132                         DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2133                         DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2134                         DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2135         },
2136         {       /* APM idle hangs */
2137                 apm_likes_to_melt, "Jabil AMD",
2138                 {       DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2139                         DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2140         },
2141         {       /* APM idle hangs */
2142                 apm_likes_to_melt, "AMI Bios",
2143                 {       DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2144                         DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2145         },
2146         {       /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2147                 swab_apm_power_in_minutes, "Sony VAIO",
2148                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2149                         DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2150                         DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2151         },
2152         {       /* Handle problems with APM on Sony Vaio PCG-N505VX */
2153                 swab_apm_power_in_minutes, "Sony VAIO",
2154                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2155                         DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2156                         DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2157         },
2158         {       /* Handle problems with APM on Sony Vaio PCG-XG29 */
2159                 swab_apm_power_in_minutes, "Sony VAIO",
2160                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2161                         DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2162                         DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2163         },
2164         {       /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2165                 swab_apm_power_in_minutes, "Sony VAIO",
2166                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2167                         DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2168                         DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2169         },
2170         {       /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2171                 swab_apm_power_in_minutes, "Sony VAIO",
2172                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2173                         DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2174                         DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2175         },
2176         {       /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2177                 swab_apm_power_in_minutes, "Sony VAIO",
2178                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2179                         DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2180                         DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2181         },
2182         {       /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2183                 swab_apm_power_in_minutes, "Sony VAIO",
2184                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2185                         DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2186                         DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2187         },
2188         {       /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2189                 swab_apm_power_in_minutes, "Sony VAIO",
2190                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2191                         DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2192                         DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2193         },
2194         {       /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2195                 swab_apm_power_in_minutes, "Sony VAIO",
2196                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2197                         DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2198                         DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2199         },
2200         {       /* Handle problems with APM on Sony Vaio PCG-F104K */
2201                 swab_apm_power_in_minutes, "Sony VAIO",
2202                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2203                         DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2204                         DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2205         },
2206 
2207         {       /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2208                 swab_apm_power_in_minutes, "Sony VAIO",
2209                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210                         DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2211                         DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2212         },
2213         {       /* Handle problems with APM on Sony Vaio PCG-C1VE */
2214                 swab_apm_power_in_minutes, "Sony VAIO",
2215                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2216                         DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2217                         DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2218         },
2219         {       /* Handle problems with APM on Sony Vaio PCG-C1VE */
2220                 swab_apm_power_in_minutes, "Sony VAIO",
2221                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2222                         DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2223                         DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2224         },
2225         {       /* broken PM poweroff bios */
2226                 set_realmode_power_off, "Award Software v4.60 PGMA",
2227                 {       DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2228                         DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2229                         DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2230         },
2231 
2232         /* Generic per vendor APM settings  */
2233 
2234         {       /* Allow interrupts during suspend on IBM laptops */
2235                 set_apm_ints, "IBM",
2236                 {       DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2237         },
2238 
2239         { }
2240 };
2241 
2242 /*
2243  * Just start the APM thread. We do NOT want to do APM BIOS
2244  * calls from anything but the APM thread, if for no other reason
2245  * than the fact that we don't trust the APM BIOS. This way,
2246  * most common APM BIOS problems that lead to protection errors
2247  * etc will have at least some level of being contained...
2248  *
2249  * In short, if something bad happens, at least we have a choice
2250  * of just killing the apm thread..
2251  */
2252 static int __init apm_init(void)
2253 {
2254         struct desc_struct *gdt;
2255         int err;
2256 
2257         dmi_check_system(apm_dmi_table);
2258 
2259         if (apm_info.bios.version == 0 || machine_is_olpc()) {
2260                 printk(KERN_INFO "apm: BIOS not found.\n");
2261                 return -ENODEV;
2262         }
2263         printk(KERN_INFO
2264                "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2265                ((apm_info.bios.version >> 8) & 0xff),
2266                (apm_info.bios.version & 0xff),
2267                apm_info.bios.flags,
2268                driver_version);
2269         if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2270                 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2271                 return -ENODEV;
2272         }
2273 
2274         if (allow_ints)
2275                 apm_info.allow_ints = 1;
2276         if (broken_psr)
2277                 apm_info.get_power_status_broken = 1;
2278         if (realmode_power_off)
2279                 apm_info.realmode_power_off = 1;
2280         /* User can override, but default is to trust DMI */
2281         if (apm_disabled != -1)
2282                 apm_info.disabled = apm_disabled;
2283 
2284         /*
2285          * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2286          * but is reportedly a 1.0 BIOS.
2287          */
2288         if (apm_info.bios.version == 0x001)
2289                 apm_info.bios.version = 0x100;
2290 
2291         /* BIOS < 1.2 doesn't set cseg_16_len */
2292         if (apm_info.bios.version < 0x102)
2293                 apm_info.bios.cseg_16_len = 0; /* 64k */
2294 
2295         if (debug) {
2296                 printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2297                         apm_info.bios.cseg, apm_info.bios.offset,
2298                         apm_info.bios.cseg_16, apm_info.bios.dseg);
2299                 if (apm_info.bios.version > 0x100)
2300                         printk(" cseg len %x, dseg len %x",
2301                                 apm_info.bios.cseg_len,
2302                                 apm_info.bios.dseg_len);
2303                 if (apm_info.bios.version > 0x101)
2304                         printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2305                 printk("\n");
2306         }
2307 
2308         if (apm_info.disabled) {
2309                 pr_notice("disabled on user request.\n");
2310                 return -ENODEV;
2311         }
2312         if ((num_online_cpus() > 1) && !power_off && !smp) {
2313                 pr_notice("disabled - APM is not SMP safe.\n");
2314                 apm_info.disabled = 1;
2315                 return -ENODEV;
2316         }
2317         if (!acpi_disabled) {
2318                 pr_notice("overridden by ACPI.\n");
2319                 apm_info.disabled = 1;
2320                 return -ENODEV;
2321         }
2322 
2323         /*
2324          * Set up the long jump entry point to the APM BIOS, which is called
2325          * from inline assembly.
2326          */
2327         apm_bios_entry.offset = apm_info.bios.offset;
2328         apm_bios_entry.segment = APM_CS;
2329 
2330         /*
2331          * The APM 1.1 BIOS is supposed to provide limit information that it
2332          * recognizes.  Many machines do this correctly, but many others do
2333          * not restrict themselves to their claimed limit.  When this happens,
2334          * they will cause a segmentation violation in the kernel at boot time.
2335          * Most BIOS's, however, will respect a 64k limit, so we use that.
2336          *
2337          * Note we only set APM segments on CPU zero, since we pin the APM
2338          * code to that CPU.
2339          */
2340         gdt = get_cpu_gdt_rw(0);
2341         set_desc_base(&gdt[APM_CS >> 3],
2342                  (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2343         set_desc_base(&gdt[APM_CS_16 >> 3],
2344                  (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2345         set_desc_base(&gdt[APM_DS >> 3],
2346                  (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2347 
2348         proc_create_single("apm", 0, NULL, proc_apm_show);
2349 
2350         kapmd_task = kthread_create(apm, NULL, "kapmd");
2351         if (IS_ERR(kapmd_task)) {
2352                 pr_err("disabled - Unable to start kernel thread\n");
2353                 err = PTR_ERR(kapmd_task);
2354                 kapmd_task = NULL;
2355                 remove_proc_entry("apm", NULL);
2356                 return err;
2357         }
2358         wake_up_process(kapmd_task);
2359 
2360         if (num_online_cpus() > 1 && !smp) {
2361                 printk(KERN_NOTICE
2362                        "apm: disabled - APM is not SMP safe (power off active).\n");
2363                 return 0;
2364         }
2365 
2366         /*
2367          * Note we don't actually care if the misc_device cannot be registered.
2368          * this driver can do its job without it, even if userspace can't
2369          * control it.  just log the error
2370          */
2371         if (misc_register(&apm_device))
2372                 printk(KERN_WARNING "apm: Could not register misc device.\n");
2373 
2374         if (HZ != 100)
2375                 idle_period = (idle_period * HZ) / 100;
2376         if (idle_threshold < 100) {
2377                 cpuidle_poll_state_init(&apm_idle_driver);
2378                 if (!cpuidle_register_driver(&apm_idle_driver))
2379                         if (cpuidle_register_device(&apm_cpuidle_device))
2380                                 cpuidle_unregister_driver(&apm_idle_driver);
2381         }
2382 
2383         return 0;
2384 }
2385 
2386 static void __exit apm_exit(void)
2387 {
2388         int error;
2389 
2390         cpuidle_unregister_device(&apm_cpuidle_device);
2391         cpuidle_unregister_driver(&apm_idle_driver);
2392 
2393         if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2394             && (apm_info.connection_version > 0x0100)) {
2395                 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2396                 if (error)
2397                         apm_error("disengage power management", error);
2398         }
2399         misc_deregister(&apm_device);
2400         remove_proc_entry("apm", NULL);
2401         if (power_off)
2402                 pm_power_off = NULL;
2403         if (kapmd_task) {
2404                 kthread_stop(kapmd_task);
2405                 kapmd_task = NULL;
2406         }
2407 }
2408 
2409 module_init(apm_init);
2410 module_exit(apm_exit);
2411 
2412 MODULE_AUTHOR("Stephen Rothwell");
2413 MODULE_DESCRIPTION("Advanced Power Management");
2414 MODULE_LICENSE("GPL");
2415 module_param(debug, bool, 0644);
2416 MODULE_PARM_DESC(debug, "Enable debug mode");
2417 module_param(power_off, bool, 0444);
2418 MODULE_PARM_DESC(power_off, "Enable power off");
2419 module_param(bounce_interval, int, 0444);
2420 MODULE_PARM_DESC(bounce_interval,
2421                 "Set the number of ticks to ignore suspend bounces");
2422 module_param(allow_ints, bool, 0444);
2423 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2424 module_param(broken_psr, bool, 0444);
2425 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2426 module_param(realmode_power_off, bool, 0444);
2427 MODULE_PARM_DESC(realmode_power_off,
2428                 "Switch to real mode before powering off");
2429 module_param(idle_threshold, int, 0444);
2430 MODULE_PARM_DESC(idle_threshold,
2431         "System idle percentage above which to make APM BIOS idle calls");
2432 module_param(idle_period, int, 0444);
2433 MODULE_PARM_DESC(idle_period,
2434         "Period (in sec/100) over which to calculate the idle percentage");
2435 module_param(smp, bool, 0444);
2436 MODULE_PARM_DESC(smp,
2437         "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2438 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
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root/arch/x86/kernel/apm_32.c

DEFINITIONS
