xref: /openbmc/linux/arch/x86/kernel/apm_32.c (revision 12eb4683)
1 /* -*- linux-c -*-
2  * APM BIOS driver for Linux
3  * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
4  *
5  * Initial development of this driver was funded by NEC Australia P/L
6  *	and NEC Corporation
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the
10  * Free Software Foundation; either version 2, or (at your option) any
11  * later version.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * October 1995, Rik Faith (faith@cs.unc.edu):
19  *    Minor enhancements and updates (to the patch set) for 1.3.x
20  *    Documentation
21  * January 1996, Rik Faith (faith@cs.unc.edu):
22  *    Make /proc/apm easy to format (bump driver version)
23  * March 1996, Rik Faith (faith@cs.unc.edu):
24  *    Prohibit APM BIOS calls unless apm_enabled.
25  *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
26  * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
27  *    Version 1.0 and 1.1
28  * May 1996, Version 1.2
29  * Feb 1998, Version 1.3
30  * Feb 1998, Version 1.4
31  * Aug 1998, Version 1.5
32  * Sep 1998, Version 1.6
33  * Nov 1998, Version 1.7
34  * Jan 1999, Version 1.8
35  * Jan 1999, Version 1.9
36  * Oct 1999, Version 1.10
37  * Nov 1999, Version 1.11
38  * Jan 2000, Version 1.12
39  * Feb 2000, Version 1.13
40  * Nov 2000, Version 1.14
41  * Oct 2001, Version 1.15
42  * Jan 2002, Version 1.16
43  * Oct 2002, Version 1.16ac
44  *
45  * History:
46  *    0.6b: first version in official kernel, Linux 1.3.46
47  *    0.7: changed /proc/apm format, Linux 1.3.58
48  *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
49  *    0.9: only call bios if bios is present, Linux 1.3.72
50  *    1.0: use fixed device number, consolidate /proc/apm into this file,
51  *         Linux 1.3.85
52  *    1.1: support user-space standby and suspend, power off after system
53  *         halted, Linux 1.3.98
54  *    1.2: When resetting RTC after resume, take care so that the time
55  *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
56  *         <jtoth@princeton.edu>); improve interaction between
57  *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
58  *    1.2a:Simple change to stop mysterious bug reports with SMP also added
59  *	   levels to the printk calls. APM is not defined for SMP machines.
60  *         The new replacement for it is, but Linux doesn't yet support this.
61  *         Alan Cox Linux 2.1.55
62  *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
63  *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
64  *         Dean Gaudet <dgaudet@arctic.org>.
65  *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
66  *    1.5: Fix segment register reloading (in case of bad segments saved
67  *         across BIOS call).
68  *         Stephen Rothwell
69  *    1.6: Cope with compiler/assembler differences.
70  *         Only try to turn off the first display device.
71  *         Fix OOPS at power off with no APM BIOS by Jan Echternach
72  *                   <echter@informatik.uni-rostock.de>
73  *         Stephen Rothwell
74  *    1.7: Modify driver's cached copy of the disabled/disengaged flags
75  *         to reflect current state of APM BIOS.
76  *         Chris Rankin <rankinc@bellsouth.net>
77  *         Reset interrupt 0 timer to 100Hz after suspend
78  *         Chad Miller <cmiller@surfsouth.com>
79  *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
80  *         Richard Gooch <rgooch@atnf.csiro.au>
81  *         Allow boot time disabling of APM
82  *         Make boot messages far less verbose by default
83  *         Make asm safer
84  *         Stephen Rothwell
85  *    1.8: Add CONFIG_APM_RTC_IS_GMT
86  *         Richard Gooch <rgooch@atnf.csiro.au>
87  *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
88  *         remove dependency on CONFIG_PROC_FS
89  *         Stephen Rothwell
90  *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
91  *         Try to cope with BIOS's that need to have all display
92  *         devices blanked and not just the first one.
93  *         Ross Paterson <ross@soi.city.ac.uk>
94  *         Fix segment limit setting it has always been wrong as
95  *         the segments needed to have byte granularity.
96  *         Mark a few things __init.
97  *         Add hack to allow power off of SMP systems by popular request.
98  *         Use CONFIG_SMP instead of __SMP__
99  *         Ignore BOUNCES for three seconds.
100  *         Stephen Rothwell
101  *   1.10: Fix for Thinkpad return code.
102  *         Merge 2.2 and 2.3 drivers.
103  *         Remove APM dependencies in arch/i386/kernel/process.c
104  *         Remove APM dependencies in drivers/char/sysrq.c
105  *         Reset time across standby.
106  *         Allow more inititialisation on SMP.
107  *         Remove CONFIG_APM_POWER_OFF and make it boot time
108  *         configurable (default on).
109  *         Make debug only a boot time parameter (remove APM_DEBUG).
110  *         Try to blank all devices on any error.
111  *   1.11: Remove APM dependencies in drivers/char/console.c
112  *         Check nr_running to detect if we are idle (from
113  *         Borislav Deianov <borislav@lix.polytechnique.fr>)
114  *         Fix for bioses that don't zero the top part of the
115  *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
116  *         (reported by Panos Katsaloulis <teras@writeme.com>).
117  *         Real mode power off patch (Walter Hofmann
118  *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
119  *   1.12: Remove CONFIG_SMP as the compiler will optimize
120  *         the code away anyway (smp_num_cpus == 1 in UP)
121  *         noted by Artur Skawina <skawina@geocities.com>.
122  *         Make power off under SMP work again.
123  *         Fix thinko with initial engaging of BIOS.
124  *         Make sure power off only happens on CPU 0
125  *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
126  *         Do error notification to user mode if BIOS calls fail.
127  *         Move entrypoint offset fix to ...boot/setup.S
128  *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
129  *         Remove smp-power-off. SMP users must now specify
130  *         "apm=power-off" on the kernel command line. Suggested
131  *         by Jim Avera <jima@hal.com>, modified by Alan Cox
132  *         <alan@lxorguk.ukuu.org.uk>.
133  *         Register the /proc/apm entry even on SMP so that
134  *         scripts that check for it before doing power off
135  *         work (Jim Avera <jima@hal.com>).
136  *   1.13: Changes for new pm_ interfaces (Andy Henroid
137  *         <andy_henroid@yahoo.com>).
138  *         Modularize the code.
139  *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
140  *         is now the way life works).
141  *         Fix thinko in suspend() (wrong return).
142  *         Notify drivers on critical suspend.
143  *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
144  *         modified by sfr).
145  *         Disable interrupts while we are suspended (Andy Henroid
146  *         <andy_henroid@yahoo.com> fixed by sfr).
147  *         Make power off work on SMP again (Tony Hoyle
148  *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
149  *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
150  *         interval is now configurable.
151  *   1.14: Make connection version persist across module unload/load.
152  *         Enable and engage power management earlier.
153  *         Disengage power management on module unload.
154  *         Changed to use the sysrq-register hack for registering the
155  *         power off function called by magic sysrq based upon discussions
156  *         in irc://irc.openprojects.net/#kernelnewbies
157  *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
158  *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
159  *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
160  *         Work around byte swap bug in one of the Vaio's BIOS's
161  *         (Marc Boucher <marc@mbsi.ca>).
162  *         Exposed the disable flag to dmi so that we can handle known
163  *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
164  *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
165  *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
166  *         If an APM idle fails log it and idle sensibly
167  *   1.15: Don't queue events to clients who open the device O_WRONLY.
168  *         Don't expect replies from clients who open the device O_RDONLY.
169  *         (Idea from Thomas Hood)
170  *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
171  *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
172  *         Notify listeners of standby or suspend events before notifying
173  *         drivers. Return EBUSY to ioctl() if suspend is rejected.
174  *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
175  *         Ignore first resume after we generate our own resume event
176  *         after a suspend (Thomas Hood)
177  *         Daemonize now gets rid of our controlling terminal (sfr).
178  *         CONFIG_APM_CPU_IDLE now just affects the default value of
179  *         idle_threshold (sfr).
180  *         Change name of kernel apm daemon (as it no longer idles) (sfr).
181  *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
182  *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
183  *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
184  *
185  * APM 1.1 Reference:
186  *
187  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
188  *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
189  *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
190  *
191  * [This document is available free from Intel by calling 800.628.8686 (fax
192  * 916.356.6100) or 800.548.4725; or from
193  * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
194  * available from Microsoft by calling 206.882.8080.]
195  *
196  * APM 1.2 Reference:
197  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
198  *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
199  *
200  * [This document is available from Microsoft at:
201  *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
202  */
203 
204 #define pr_fmt(fmt) "apm: " fmt
205 
206 #include <linux/module.h>
207 
208 #include <linux/poll.h>
209 #include <linux/types.h>
210 #include <linux/stddef.h>
211 #include <linux/timer.h>
212 #include <linux/fcntl.h>
213 #include <linux/slab.h>
214 #include <linux/stat.h>
215 #include <linux/proc_fs.h>
216 #include <linux/seq_file.h>
217 #include <linux/miscdevice.h>
218 #include <linux/apm_bios.h>
219 #include <linux/init.h>
220 #include <linux/time.h>
221 #include <linux/sched.h>
222 #include <linux/pm.h>
223 #include <linux/capability.h>
224 #include <linux/device.h>
225 #include <linux/kernel.h>
226 #include <linux/freezer.h>
227 #include <linux/smp.h>
228 #include <linux/dmi.h>
229 #include <linux/suspend.h>
230 #include <linux/kthread.h>
231 #include <linux/jiffies.h>
232 #include <linux/acpi.h>
233 #include <linux/syscore_ops.h>
234 #include <linux/i8253.h>
235 #include <linux/cpuidle.h>
236 
237 #include <asm/uaccess.h>
238 #include <asm/desc.h>
239 #include <asm/olpc.h>
240 #include <asm/paravirt.h>
241 #include <asm/reboot.h>
242 
243 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
244 extern int (*console_blank_hook)(int);
245 #endif
246 
247 /*
248  * The apm_bios device is one of the misc char devices.
249  * This is its minor number.
250  */
251 #define	APM_MINOR_DEV	134
252 
253 /*
254  * Various options can be changed at boot time as follows:
255  * (We allow underscores for compatibility with the modules code)
256  *	apm=on/off			enable/disable APM
257  *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
258  *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
259  *	    [no-]realmode[-_]power[-_]off	switch to real mode before
260  *	    					powering off
261  *	    [no-]debug			log some debugging messages
262  *	    [no-]power[-_]off		power off on shutdown
263  *	    [no-]smp			Use apm even on an SMP box
264  *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
265  *	    				bounces
266  *          idle[-_]threshold=<n>       System idle percentage above which to
267  *                                      make APM BIOS idle calls. Set it to
268  *                                      100 to disable.
269  *          idle[-_]period=<n>          Period (in 1/100s of a second) over
270  *                                      which the idle percentage is
271  *                                      calculated.
272  */
273 
274 /* KNOWN PROBLEM MACHINES:
275  *
276  * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
277  *                         [Confirmed by TI representative]
278  * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
279  *                    [Confirmed by BIOS disassembly]
280  *                    [This may work now ...]
281  * P: Toshiba 1950S: battery life information only gets updated after resume
282  * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
283  * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
284  * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
285  * 	Neale Banks <neale@lowendale.com.au> December 2000
286  *
287  * Legend: U = unusable with APM patches
288  *         P = partially usable with APM patches
289  */
290 
291 /*
292  * Define as 1 to make the driver always call the APM BIOS busy
293  * routine even if the clock was not reported as slowed by the
294  * idle routine.  Otherwise, define as 0.
295  */
296 #define ALWAYS_CALL_BUSY   1
297 
298 /*
299  * Define to make the APM BIOS calls zero all data segment registers (so
300  * that an incorrect BIOS implementation will cause a kernel panic if it
301  * tries to write to arbitrary memory).
302  */
303 #define APM_ZERO_SEGS
304 
305 #include <asm/apm.h>
306 
307 /*
308  * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
309  * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
310  * David Chen <chen@ctpa04.mit.edu>
311  */
312 #undef INIT_TIMER_AFTER_SUSPEND
313 
314 #ifdef INIT_TIMER_AFTER_SUSPEND
315 #include <linux/timex.h>
316 #include <asm/io.h>
317 #include <linux/delay.h>
318 #endif
319 
320 /*
321  * Need to poll the APM BIOS every second
322  */
323 #define APM_CHECK_TIMEOUT	(HZ)
324 
325 /*
326  * Ignore suspend events for this amount of time after a resume
327  */
328 #define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
329 
330 /*
331  * Maximum number of events stored
332  */
333 #define APM_MAX_EVENTS		20
334 
335 /*
336  * The per-file APM data
337  */
338 struct apm_user {
339 	int		magic;
340 	struct apm_user *next;
341 	unsigned int	suser: 1;
342 	unsigned int	writer: 1;
343 	unsigned int	reader: 1;
344 	unsigned int	suspend_wait: 1;
345 	int		suspend_result;
346 	int		suspends_pending;
347 	int		standbys_pending;
348 	int		suspends_read;
349 	int		standbys_read;
350 	int		event_head;
351 	int		event_tail;
352 	apm_event_t	events[APM_MAX_EVENTS];
353 };
354 
355 /*
356  * The magic number in apm_user
357  */
358 #define APM_BIOS_MAGIC		0x4101
359 
360 /*
361  * idle percentage above which bios idle calls are done
362  */
363 #ifdef CONFIG_APM_CPU_IDLE
364 #define DEFAULT_IDLE_THRESHOLD	95
365 #else
366 #define DEFAULT_IDLE_THRESHOLD	100
367 #endif
368 #define DEFAULT_IDLE_PERIOD	(100 / 3)
369 
370 static int apm_cpu_idle(struct cpuidle_device *dev,
371 			struct cpuidle_driver *drv, int index);
372 
373 static struct cpuidle_driver apm_idle_driver = {
374 	.name = "apm_idle",
375 	.owner = THIS_MODULE,
376 	.states = {
377 		{ /* entry 0 is for polling */ },
378 		{ /* entry 1 is for APM idle */
379 			.name = "APM",
380 			.desc = "APM idle",
381 			.flags = CPUIDLE_FLAG_TIME_VALID,
382 			.exit_latency = 250,	/* WAG */
383 			.target_residency = 500,	/* WAG */
384 			.enter = &apm_cpu_idle
385 		},
386 	},
387 	.state_count = 2,
388 };
389 
390 static struct cpuidle_device apm_cpuidle_device;
391 
392 /*
393  * Local variables
394  */
395 __visible struct {
396 	unsigned long	offset;
397 	unsigned short	segment;
398 } apm_bios_entry;
399 static int clock_slowed;
400 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
401 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
402 static int suspends_pending;
403 static int standbys_pending;
404 static int ignore_sys_suspend;
405 static int ignore_normal_resume;
406 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
407 
408 static bool debug __read_mostly;
409 static bool smp __read_mostly;
410 static int apm_disabled = -1;
411 #ifdef CONFIG_SMP
412 static bool power_off;
413 #else
414 static bool power_off = 1;
415 #endif
416 static bool realmode_power_off;
417 #ifdef CONFIG_APM_ALLOW_INTS
418 static bool allow_ints = 1;
419 #else
420 static bool allow_ints;
421 #endif
422 static bool broken_psr;
423 
424 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
425 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
426 static struct apm_user *user_list;
427 static DEFINE_SPINLOCK(user_list_lock);
428 static DEFINE_MUTEX(apm_mutex);
429 
430 /*
431  * Set up a segment that references the real mode segment 0x40
432  * that extends up to the end of page zero (that we have reserved).
433  * This is for buggy BIOS's that refer to (real mode) segment 0x40
434  * even though they are called in protected mode.
435  */
436 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
437 			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
438 
439 static const char driver_version[] = "1.16ac";	/* no spaces */
440 
441 static struct task_struct *kapmd_task;
442 
443 /*
444  *	APM event names taken from the APM 1.2 specification. These are
445  *	the message codes that the BIOS uses to tell us about events
446  */
447 static const char * const apm_event_name[] = {
448 	"system standby",
449 	"system suspend",
450 	"normal resume",
451 	"critical resume",
452 	"low battery",
453 	"power status change",
454 	"update time",
455 	"critical suspend",
456 	"user standby",
457 	"user suspend",
458 	"system standby resume",
459 	"capabilities change"
460 };
461 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
462 
463 typedef struct lookup_t {
464 	int	key;
465 	char 	*msg;
466 } lookup_t;
467 
468 /*
469  *	The BIOS returns a set of standard error codes in AX when the
470  *	carry flag is set.
471  */
472 
473 static const lookup_t error_table[] = {
474 /* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
475 	{ APM_DISABLED,		"Power management disabled" },
476 	{ APM_CONNECTED,	"Real mode interface already connected" },
477 	{ APM_NOT_CONNECTED,	"Interface not connected" },
478 	{ APM_16_CONNECTED,	"16 bit interface already connected" },
479 /* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
480 	{ APM_32_CONNECTED,	"32 bit interface already connected" },
481 	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
482 	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
483 	{ APM_BAD_PARAM,	"Parameter out of range" },
484 	{ APM_NOT_ENGAGED,	"Interface not engaged" },
485 	{ APM_BAD_FUNCTION,     "Function not supported" },
486 	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
487 	{ APM_BAD_STATE,	"Unable to enter requested state" },
488 /* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
489 	{ APM_NO_ERROR,		"BIOS did not set a return code" },
490 	{ APM_NOT_PRESENT,	"No APM present" }
491 };
492 #define ERROR_COUNT	ARRAY_SIZE(error_table)
493 
494 /**
495  *	apm_error	-	display an APM error
496  *	@str: information string
497  *	@err: APM BIOS return code
498  *
499  *	Write a meaningful log entry to the kernel log in the event of
500  *	an APM error.  Note that this also handles (negative) kernel errors.
501  */
502 
503 static void apm_error(char *str, int err)
504 {
505 	int i;
506 
507 	for (i = 0; i < ERROR_COUNT; i++)
508 		if (error_table[i].key == err)
509 			break;
510 	if (i < ERROR_COUNT)
511 		pr_notice("%s: %s\n", str, error_table[i].msg);
512 	else if (err < 0)
513 		pr_notice("%s: linux error code %i\n", str, err);
514 	else
515 		pr_notice("%s: unknown error code %#2.2x\n",
516 		       str, err);
517 }
518 
519 /*
520  * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
521  * apm_info.allow_ints, we are being really paranoid here!  Not only
522  * are interrupts disabled, but all the segment registers (except SS)
523  * are saved and zeroed this means that if the BIOS tries to reference
524  * any data without explicitly loading the segment registers, the kernel
525  * will fault immediately rather than have some unforeseen circumstances
526  * for the rest of the kernel.  And it will be very obvious!  :-) Doing
527  * this depends on CS referring to the same physical memory as DS so that
528  * DS can be zeroed before the call. Unfortunately, we can't do anything
529  * about the stack segment/pointer.  Also, we tell the compiler that
530  * everything could change.
531  *
532  * Also, we KNOW that for the non error case of apm_bios_call, there
533  * is no useful data returned in the low order 8 bits of eax.
534  */
535 
536 static inline unsigned long __apm_irq_save(void)
537 {
538 	unsigned long flags;
539 	local_save_flags(flags);
540 	if (apm_info.allow_ints) {
541 		if (irqs_disabled_flags(flags))
542 			local_irq_enable();
543 	} else
544 		local_irq_disable();
545 
546 	return flags;
547 }
548 
549 #define apm_irq_save(flags) \
550 	do { flags = __apm_irq_save(); } while (0)
551 
552 static inline void apm_irq_restore(unsigned long flags)
553 {
554 	if (irqs_disabled_flags(flags))
555 		local_irq_disable();
556 	else if (irqs_disabled())
557 		local_irq_enable();
558 }
559 
560 #ifdef APM_ZERO_SEGS
561 #	define APM_DECL_SEGS \
562 		unsigned int saved_fs; unsigned int saved_gs;
563 #	define APM_DO_SAVE_SEGS \
564 		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
565 #	define APM_DO_RESTORE_SEGS \
566 		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
567 #else
568 #	define APM_DECL_SEGS
569 #	define APM_DO_SAVE_SEGS
570 #	define APM_DO_RESTORE_SEGS
571 #endif
572 
573 struct apm_bios_call {
574 	u32 func;
575 	/* In and out */
576 	u32 ebx;
577 	u32 ecx;
578 	/* Out only */
579 	u32 eax;
580 	u32 edx;
581 	u32 esi;
582 
583 	/* Error: -ENOMEM, or bits 8-15 of eax */
584 	int err;
585 };
586 
587 /**
588  *	__apm_bios_call - Make an APM BIOS 32bit call
589  *	@_call: pointer to struct apm_bios_call.
590  *
591  *	Make an APM call using the 32bit protected mode interface. The
592  *	caller is responsible for knowing if APM BIOS is configured and
593  *	enabled. This call can disable interrupts for a long period of
594  *	time on some laptops.  The return value is in AH and the carry
595  *	flag is loaded into AL.  If there is an error, then the error
596  *	code is returned in AH (bits 8-15 of eax) and this function
597  *	returns non-zero.
598  *
599  *	Note: this makes the call on the current CPU.
600  */
601 static long __apm_bios_call(void *_call)
602 {
603 	APM_DECL_SEGS
604 	unsigned long		flags;
605 	int			cpu;
606 	struct desc_struct	save_desc_40;
607 	struct desc_struct	*gdt;
608 	struct apm_bios_call	*call = _call;
609 
610 	cpu = get_cpu();
611 	BUG_ON(cpu != 0);
612 	gdt = get_cpu_gdt_table(cpu);
613 	save_desc_40 = gdt[0x40 / 8];
614 	gdt[0x40 / 8] = bad_bios_desc;
615 
616 	apm_irq_save(flags);
617 	APM_DO_SAVE_SEGS;
618 	apm_bios_call_asm(call->func, call->ebx, call->ecx,
619 			  &call->eax, &call->ebx, &call->ecx, &call->edx,
620 			  &call->esi);
621 	APM_DO_RESTORE_SEGS;
622 	apm_irq_restore(flags);
623 	gdt[0x40 / 8] = save_desc_40;
624 	put_cpu();
625 
626 	return call->eax & 0xff;
627 }
628 
629 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
630 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
631 {
632 	int ret;
633 
634 	/* Don't bother with work_on_cpu in the common case, so we don't
635 	 * have to worry about OOM or overhead. */
636 	if (get_cpu() == 0) {
637 		ret = fn(call);
638 		put_cpu();
639 	} else {
640 		put_cpu();
641 		ret = work_on_cpu(0, fn, call);
642 	}
643 
644 	/* work_on_cpu can fail with -ENOMEM */
645 	if (ret < 0)
646 		call->err = ret;
647 	else
648 		call->err = (call->eax >> 8) & 0xff;
649 
650 	return ret;
651 }
652 
653 /**
654  *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
655  *	@call: the apm_bios_call registers.
656  *
657  *	If there is an error, it is returned in @call.err.
658  */
659 static int apm_bios_call(struct apm_bios_call *call)
660 {
661 	return on_cpu0(__apm_bios_call, call);
662 }
663 
664 /**
665  *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
666  *	@_call: pointer to struct apm_bios_call.
667  *
668  *	Make a BIOS call that returns one value only, or just status.
669  *	If there is an error, then the error code is returned in AH
670  *	(bits 8-15 of eax) and this function returns non-zero (it can
671  *	also return -ENOMEM). This is used for simpler BIOS operations.
672  *	This call may hold interrupts off for a long time on some laptops.
673  *
674  *	Note: this makes the call on the current CPU.
675  */
676 static long __apm_bios_call_simple(void *_call)
677 {
678 	u8			error;
679 	APM_DECL_SEGS
680 	unsigned long		flags;
681 	int			cpu;
682 	struct desc_struct	save_desc_40;
683 	struct desc_struct	*gdt;
684 	struct apm_bios_call	*call = _call;
685 
686 	cpu = get_cpu();
687 	BUG_ON(cpu != 0);
688 	gdt = get_cpu_gdt_table(cpu);
689 	save_desc_40 = gdt[0x40 / 8];
690 	gdt[0x40 / 8] = bad_bios_desc;
691 
692 	apm_irq_save(flags);
693 	APM_DO_SAVE_SEGS;
694 	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
695 					 &call->eax);
696 	APM_DO_RESTORE_SEGS;
697 	apm_irq_restore(flags);
698 	gdt[0x40 / 8] = save_desc_40;
699 	put_cpu();
700 	return error;
701 }
702 
703 /**
704  *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
705  *	@func: APM function to invoke
706  *	@ebx_in: EBX register value for BIOS call
707  *	@ecx_in: ECX register value for BIOS call
708  *	@eax: EAX register on return from the BIOS call
709  *	@err: bits
710  *
711  *	Make a BIOS call that returns one value only, or just status.
712  *	If there is an error, then the error code is returned in @err
713  *	and this function returns non-zero. This is used for simpler
714  *	BIOS operations.  This call may hold interrupts off for a long
715  *	time on some laptops.
716  */
717 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
718 				int *err)
719 {
720 	struct apm_bios_call call;
721 	int ret;
722 
723 	call.func = func;
724 	call.ebx = ebx_in;
725 	call.ecx = ecx_in;
726 
727 	ret = on_cpu0(__apm_bios_call_simple, &call);
728 	*eax = call.eax;
729 	*err = call.err;
730 	return ret;
731 }
732 
733 /**
734  *	apm_driver_version	-	APM driver version
735  *	@val:	loaded with the APM version on return
736  *
737  *	Retrieve the APM version supported by the BIOS. This is only
738  *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
739  *	probably present.
740  *
741  *	On entry val should point to a value indicating the APM driver
742  *	version with the high byte being the major and the low byte the
743  *	minor number both in BCD
744  *
745  *	On return it will hold the BIOS revision supported in the
746  *	same format.
747  */
748 
749 static int apm_driver_version(u_short *val)
750 {
751 	u32 eax;
752 	int err;
753 
754 	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
755 		return err;
756 	*val = eax;
757 	return APM_SUCCESS;
758 }
759 
760 /**
761  *	apm_get_event	-	get an APM event from the BIOS
762  *	@event: pointer to the event
763  *	@info: point to the event information
764  *
765  *	The APM BIOS provides a polled information for event
766  *	reporting. The BIOS expects to be polled at least every second
767  *	when events are pending. When a message is found the caller should
768  *	poll until no more messages are present.  However, this causes
769  *	problems on some laptops where a suspend event notification is
770  *	not cleared until it is acknowledged.
771  *
772  *	Additional information is returned in the info pointer, providing
773  *	that APM 1.2 is in use. If no messges are pending the value 0x80
774  *	is returned (No power management events pending).
775  */
776 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
777 {
778 	struct apm_bios_call call;
779 
780 	call.func = APM_FUNC_GET_EVENT;
781 	call.ebx = call.ecx = 0;
782 
783 	if (apm_bios_call(&call))
784 		return call.err;
785 
786 	*event = call.ebx;
787 	if (apm_info.connection_version < 0x0102)
788 		*info = ~0; /* indicate info not valid */
789 	else
790 		*info = call.ecx;
791 	return APM_SUCCESS;
792 }
793 
794 /**
795  *	set_power_state	-	set the power management state
796  *	@what: which items to transition
797  *	@state: state to transition to
798  *
799  *	Request an APM change of state for one or more system devices. The
800  *	processor state must be transitioned last of all. what holds the
801  *	class of device in the upper byte and the device number (0xFF for
802  *	all) for the object to be transitioned.
803  *
804  *	The state holds the state to transition to, which may in fact
805  *	be an acceptance of a BIOS requested state change.
806  */
807 
808 static int set_power_state(u_short what, u_short state)
809 {
810 	u32 eax;
811 	int err;
812 
813 	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
814 		return err;
815 	return APM_SUCCESS;
816 }
817 
818 /**
819  *	set_system_power_state - set system wide power state
820  *	@state: which state to enter
821  *
822  *	Transition the entire system into a new APM power state.
823  */
824 
825 static int set_system_power_state(u_short state)
826 {
827 	return set_power_state(APM_DEVICE_ALL, state);
828 }
829 
830 /**
831  *	apm_do_idle	-	perform power saving
832  *
833  *	This function notifies the BIOS that the processor is (in the view
834  *	of the OS) idle. It returns -1 in the event that the BIOS refuses
835  *	to handle the idle request. On a success the function returns 1
836  *	if the BIOS did clock slowing or 0 otherwise.
837  */
838 
839 static int apm_do_idle(void)
840 {
841 	u32 eax;
842 	u8 ret = 0;
843 	int idled = 0;
844 	int polling;
845 	int err = 0;
846 
847 	polling = !!(current_thread_info()->status & TS_POLLING);
848 	if (polling) {
849 		current_thread_info()->status &= ~TS_POLLING;
850 		/*
851 		 * TS_POLLING-cleared state must be visible before we
852 		 * test NEED_RESCHED:
853 		 */
854 		smp_mb();
855 	}
856 	if (!need_resched()) {
857 		idled = 1;
858 		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
859 	}
860 	if (polling)
861 		current_thread_info()->status |= TS_POLLING;
862 
863 	if (!idled)
864 		return 0;
865 
866 	if (ret) {
867 		static unsigned long t;
868 
869 		/* This always fails on some SMP boards running UP kernels.
870 		 * Only report the failure the first 5 times.
871 		 */
872 		if (++t < 5) {
873 			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
874 			t = jiffies;
875 		}
876 		return -1;
877 	}
878 	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
879 	return clock_slowed;
880 }
881 
882 /**
883  *	apm_do_busy	-	inform the BIOS the CPU is busy
884  *
885  *	Request that the BIOS brings the CPU back to full performance.
886  */
887 
888 static void apm_do_busy(void)
889 {
890 	u32 dummy;
891 	int err;
892 
893 	if (clock_slowed || ALWAYS_CALL_BUSY) {
894 		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
895 		clock_slowed = 0;
896 	}
897 }
898 
899 /*
900  * If no process has really been interested in
901  * the CPU for some time, we want to call BIOS
902  * power management - we probably want
903  * to conserve power.
904  */
905 #define IDLE_CALC_LIMIT	(HZ * 100)
906 #define IDLE_LEAKY_MAX	16
907 
908 /**
909  * apm_cpu_idle		-	cpu idling for APM capable Linux
910  *
911  * This is the idling function the kernel executes when APM is available. It
912  * tries to do BIOS powermanagement based on the average system idle time.
913  * Furthermore it calls the system default idle routine.
914  */
915 
916 static int apm_cpu_idle(struct cpuidle_device *dev,
917 	struct cpuidle_driver *drv, int index)
918 {
919 	static int use_apm_idle; /* = 0 */
920 	static unsigned int last_jiffies; /* = 0 */
921 	static unsigned int last_stime; /* = 0 */
922 	cputime_t stime;
923 
924 	int apm_idle_done = 0;
925 	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
926 	unsigned int bucket;
927 
928 recalc:
929 	task_cputime(current, NULL, &stime);
930 	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
931 		use_apm_idle = 0;
932 	} else if (jiffies_since_last_check > idle_period) {
933 		unsigned int idle_percentage;
934 
935 		idle_percentage = stime - last_stime;
936 		idle_percentage *= 100;
937 		idle_percentage /= jiffies_since_last_check;
938 		use_apm_idle = (idle_percentage > idle_threshold);
939 		if (apm_info.forbid_idle)
940 			use_apm_idle = 0;
941 	}
942 
943 	last_jiffies = jiffies;
944 	last_stime = stime;
945 
946 	bucket = IDLE_LEAKY_MAX;
947 
948 	while (!need_resched()) {
949 		if (use_apm_idle) {
950 			unsigned int t;
951 
952 			t = jiffies;
953 			switch (apm_do_idle()) {
954 			case 0:
955 				apm_idle_done = 1;
956 				if (t != jiffies) {
957 					if (bucket) {
958 						bucket = IDLE_LEAKY_MAX;
959 						continue;
960 					}
961 				} else if (bucket) {
962 					bucket--;
963 					continue;
964 				}
965 				break;
966 			case 1:
967 				apm_idle_done = 1;
968 				break;
969 			default: /* BIOS refused */
970 				break;
971 			}
972 		}
973 		default_idle();
974 		local_irq_disable();
975 		jiffies_since_last_check = jiffies - last_jiffies;
976 		if (jiffies_since_last_check > idle_period)
977 			goto recalc;
978 	}
979 
980 	if (apm_idle_done)
981 		apm_do_busy();
982 
983 	return index;
984 }
985 
986 /**
987  *	apm_power_off	-	ask the BIOS to power off
988  *
989  *	Handle the power off sequence. This is the one piece of code we
990  *	will execute even on SMP machines. In order to deal with BIOS
991  *	bugs we support real mode APM BIOS power off calls. We also make
992  *	the SMP call on CPU0 as some systems will only honour this call
993  *	on their first cpu.
994  */
995 
996 static void apm_power_off(void)
997 {
998 	/* Some bioses don't like being called from CPU != 0 */
999 	if (apm_info.realmode_power_off) {
1000 		set_cpus_allowed_ptr(current, cpumask_of(0));
1001 		machine_real_restart(MRR_APM);
1002 	} else {
1003 		(void)set_system_power_state(APM_STATE_OFF);
1004 	}
1005 }
1006 
1007 #ifdef CONFIG_APM_DO_ENABLE
1008 
1009 /**
1010  *	apm_enable_power_management - enable BIOS APM power management
1011  *	@enable: enable yes/no
1012  *
1013  *	Enable or disable the APM BIOS power services.
1014  */
1015 
1016 static int apm_enable_power_management(int enable)
1017 {
1018 	u32 eax;
1019 	int err;
1020 
1021 	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1022 		return APM_NOT_ENGAGED;
1023 	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1024 				 enable, &eax, &err))
1025 		return err;
1026 	if (enable)
1027 		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1028 	else
1029 		apm_info.bios.flags |= APM_BIOS_DISABLED;
1030 	return APM_SUCCESS;
1031 }
1032 #endif
1033 
1034 /**
1035  *	apm_get_power_status	-	get current power state
1036  *	@status: returned status
1037  *	@bat: battery info
1038  *	@life: estimated life
1039  *
1040  *	Obtain the current power status from the APM BIOS. We return a
1041  *	status which gives the rough battery status, and current power
1042  *	source. The bat value returned give an estimate as a percentage
1043  *	of life and a status value for the battery. The estimated life
1044  *	if reported is a lifetime in secodnds/minutes at current powwer
1045  *	consumption.
1046  */
1047 
1048 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1049 {
1050 	struct apm_bios_call call;
1051 
1052 	call.func = APM_FUNC_GET_STATUS;
1053 	call.ebx = APM_DEVICE_ALL;
1054 	call.ecx = 0;
1055 
1056 	if (apm_info.get_power_status_broken)
1057 		return APM_32_UNSUPPORTED;
1058 	if (apm_bios_call(&call))
1059 		return call.err;
1060 	*status = call.ebx;
1061 	*bat = call.ecx;
1062 	if (apm_info.get_power_status_swabinminutes) {
1063 		*life = swab16((u16)call.edx);
1064 		*life |= 0x8000;
1065 	} else
1066 		*life = call.edx;
1067 	return APM_SUCCESS;
1068 }
1069 
1070 #if 0
1071 static int apm_get_battery_status(u_short which, u_short *status,
1072 				  u_short *bat, u_short *life, u_short *nbat)
1073 {
1074 	u32 eax;
1075 	u32 ebx;
1076 	u32 ecx;
1077 	u32 edx;
1078 	u32 esi;
1079 
1080 	if (apm_info.connection_version < 0x0102) {
1081 		/* pretend we only have one battery. */
1082 		if (which != 1)
1083 			return APM_BAD_DEVICE;
1084 		*nbat = 1;
1085 		return apm_get_power_status(status, bat, life);
1086 	}
1087 
1088 	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1089 			  &ebx, &ecx, &edx, &esi))
1090 		return (eax >> 8) & 0xff;
1091 	*status = ebx;
1092 	*bat = ecx;
1093 	*life = edx;
1094 	*nbat = esi;
1095 	return APM_SUCCESS;
1096 }
1097 #endif
1098 
1099 /**
1100  *	apm_engage_power_management	-	enable PM on a device
1101  *	@device: identity of device
1102  *	@enable: on/off
1103  *
1104  *	Activate or deactive power management on either a specific device
1105  *	or the entire system (%APM_DEVICE_ALL).
1106  */
1107 
1108 static int apm_engage_power_management(u_short device, int enable)
1109 {
1110 	u32 eax;
1111 	int err;
1112 
1113 	if ((enable == 0) && (device == APM_DEVICE_ALL)
1114 	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1115 		return APM_DISABLED;
1116 	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1117 				 &eax, &err))
1118 		return err;
1119 	if (device == APM_DEVICE_ALL) {
1120 		if (enable)
1121 			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1122 		else
1123 			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1124 	}
1125 	return APM_SUCCESS;
1126 }
1127 
1128 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1129 
1130 /**
1131  *	apm_console_blank	-	blank the display
1132  *	@blank: on/off
1133  *
1134  *	Attempt to blank the console, firstly by blanking just video device
1135  *	zero, and if that fails (some BIOSes don't support it) then it blanks
1136  *	all video devices. Typically the BIOS will do laptop backlight and
1137  *	monitor powerdown for us.
1138  */
1139 
1140 static int apm_console_blank(int blank)
1141 {
1142 	int error = APM_NOT_ENGAGED; /* silence gcc */
1143 	int i;
1144 	u_short state;
1145 	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1146 
1147 	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1148 
1149 	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1150 		error = set_power_state(dev[i], state);
1151 
1152 		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1153 			return 1;
1154 
1155 		if (error == APM_NOT_ENGAGED)
1156 			break;
1157 	}
1158 
1159 	if (error == APM_NOT_ENGAGED) {
1160 		static int tried;
1161 		int eng_error;
1162 		if (tried++ == 0) {
1163 			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1164 			if (eng_error) {
1165 				apm_error("set display", error);
1166 				apm_error("engage interface", eng_error);
1167 				return 0;
1168 			} else
1169 				return apm_console_blank(blank);
1170 		}
1171 	}
1172 	apm_error("set display", error);
1173 	return 0;
1174 }
1175 #endif
1176 
1177 static int queue_empty(struct apm_user *as)
1178 {
1179 	return as->event_head == as->event_tail;
1180 }
1181 
1182 static apm_event_t get_queued_event(struct apm_user *as)
1183 {
1184 	if (++as->event_tail >= APM_MAX_EVENTS)
1185 		as->event_tail = 0;
1186 	return as->events[as->event_tail];
1187 }
1188 
1189 static void queue_event(apm_event_t event, struct apm_user *sender)
1190 {
1191 	struct apm_user *as;
1192 
1193 	spin_lock(&user_list_lock);
1194 	if (user_list == NULL)
1195 		goto out;
1196 	for (as = user_list; as != NULL; as = as->next) {
1197 		if ((as == sender) || (!as->reader))
1198 			continue;
1199 		if (++as->event_head >= APM_MAX_EVENTS)
1200 			as->event_head = 0;
1201 
1202 		if (as->event_head == as->event_tail) {
1203 			static int notified;
1204 
1205 			if (notified++ == 0)
1206 				pr_err("an event queue overflowed\n");
1207 			if (++as->event_tail >= APM_MAX_EVENTS)
1208 				as->event_tail = 0;
1209 		}
1210 		as->events[as->event_head] = event;
1211 		if (!as->suser || !as->writer)
1212 			continue;
1213 		switch (event) {
1214 		case APM_SYS_SUSPEND:
1215 		case APM_USER_SUSPEND:
1216 			as->suspends_pending++;
1217 			suspends_pending++;
1218 			break;
1219 
1220 		case APM_SYS_STANDBY:
1221 		case APM_USER_STANDBY:
1222 			as->standbys_pending++;
1223 			standbys_pending++;
1224 			break;
1225 		}
1226 	}
1227 	wake_up_interruptible(&apm_waitqueue);
1228 out:
1229 	spin_unlock(&user_list_lock);
1230 }
1231 
1232 static void reinit_timer(void)
1233 {
1234 #ifdef INIT_TIMER_AFTER_SUSPEND
1235 	unsigned long flags;
1236 
1237 	raw_spin_lock_irqsave(&i8253_lock, flags);
1238 	/* set the clock to HZ */
1239 	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1240 	udelay(10);
1241 	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1242 	udelay(10);
1243 	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1244 	udelay(10);
1245 	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1246 #endif
1247 }
1248 
1249 static int suspend(int vetoable)
1250 {
1251 	int err;
1252 	struct apm_user	*as;
1253 
1254 	dpm_suspend_start(PMSG_SUSPEND);
1255 	dpm_suspend_end(PMSG_SUSPEND);
1256 
1257 	local_irq_disable();
1258 	syscore_suspend();
1259 
1260 	local_irq_enable();
1261 
1262 	save_processor_state();
1263 	err = set_system_power_state(APM_STATE_SUSPEND);
1264 	ignore_normal_resume = 1;
1265 	restore_processor_state();
1266 
1267 	local_irq_disable();
1268 	reinit_timer();
1269 
1270 	if (err == APM_NO_ERROR)
1271 		err = APM_SUCCESS;
1272 	if (err != APM_SUCCESS)
1273 		apm_error("suspend", err);
1274 	err = (err == APM_SUCCESS) ? 0 : -EIO;
1275 
1276 	syscore_resume();
1277 	local_irq_enable();
1278 
1279 	dpm_resume_start(PMSG_RESUME);
1280 	dpm_resume_end(PMSG_RESUME);
1281 
1282 	queue_event(APM_NORMAL_RESUME, NULL);
1283 	spin_lock(&user_list_lock);
1284 	for (as = user_list; as != NULL; as = as->next) {
1285 		as->suspend_wait = 0;
1286 		as->suspend_result = err;
1287 	}
1288 	spin_unlock(&user_list_lock);
1289 	wake_up_interruptible(&apm_suspend_waitqueue);
1290 	return err;
1291 }
1292 
1293 static void standby(void)
1294 {
1295 	int err;
1296 
1297 	dpm_suspend_end(PMSG_SUSPEND);
1298 
1299 	local_irq_disable();
1300 	syscore_suspend();
1301 	local_irq_enable();
1302 
1303 	err = set_system_power_state(APM_STATE_STANDBY);
1304 	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1305 		apm_error("standby", err);
1306 
1307 	local_irq_disable();
1308 	syscore_resume();
1309 	local_irq_enable();
1310 
1311 	dpm_resume_start(PMSG_RESUME);
1312 }
1313 
1314 static apm_event_t get_event(void)
1315 {
1316 	int error;
1317 	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1318 	apm_eventinfo_t	info;
1319 
1320 	static int notified;
1321 
1322 	/* we don't use the eventinfo */
1323 	error = apm_get_event(&event, &info);
1324 	if (error == APM_SUCCESS)
1325 		return event;
1326 
1327 	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1328 		apm_error("get_event", error);
1329 
1330 	return 0;
1331 }
1332 
1333 static void check_events(void)
1334 {
1335 	apm_event_t event;
1336 	static unsigned long last_resume;
1337 	static int ignore_bounce;
1338 
1339 	while ((event = get_event()) != 0) {
1340 		if (debug) {
1341 			if (event <= NR_APM_EVENT_NAME)
1342 				printk(KERN_DEBUG "apm: received %s notify\n",
1343 				       apm_event_name[event - 1]);
1344 			else
1345 				printk(KERN_DEBUG "apm: received unknown "
1346 				       "event 0x%02x\n", event);
1347 		}
1348 		if (ignore_bounce
1349 		    && (time_after(jiffies, last_resume + bounce_interval)))
1350 			ignore_bounce = 0;
1351 
1352 		switch (event) {
1353 		case APM_SYS_STANDBY:
1354 		case APM_USER_STANDBY:
1355 			queue_event(event, NULL);
1356 			if (standbys_pending <= 0)
1357 				standby();
1358 			break;
1359 
1360 		case APM_USER_SUSPEND:
1361 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1362 			if (apm_info.connection_version > 0x100)
1363 				set_system_power_state(APM_STATE_REJECT);
1364 			break;
1365 #endif
1366 		case APM_SYS_SUSPEND:
1367 			if (ignore_bounce) {
1368 				if (apm_info.connection_version > 0x100)
1369 					set_system_power_state(APM_STATE_REJECT);
1370 				break;
1371 			}
1372 			/*
1373 			 * If we are already processing a SUSPEND,
1374 			 * then further SUSPEND events from the BIOS
1375 			 * will be ignored.  We also return here to
1376 			 * cope with the fact that the Thinkpads keep
1377 			 * sending a SUSPEND event until something else
1378 			 * happens!
1379 			 */
1380 			if (ignore_sys_suspend)
1381 				return;
1382 			ignore_sys_suspend = 1;
1383 			queue_event(event, NULL);
1384 			if (suspends_pending <= 0)
1385 				(void) suspend(1);
1386 			break;
1387 
1388 		case APM_NORMAL_RESUME:
1389 		case APM_CRITICAL_RESUME:
1390 		case APM_STANDBY_RESUME:
1391 			ignore_sys_suspend = 0;
1392 			last_resume = jiffies;
1393 			ignore_bounce = 1;
1394 			if ((event != APM_NORMAL_RESUME)
1395 			    || (ignore_normal_resume == 0)) {
1396 				dpm_resume_end(PMSG_RESUME);
1397 				queue_event(event, NULL);
1398 			}
1399 			ignore_normal_resume = 0;
1400 			break;
1401 
1402 		case APM_CAPABILITY_CHANGE:
1403 		case APM_LOW_BATTERY:
1404 		case APM_POWER_STATUS_CHANGE:
1405 			queue_event(event, NULL);
1406 			/* If needed, notify drivers here */
1407 			break;
1408 
1409 		case APM_UPDATE_TIME:
1410 			break;
1411 
1412 		case APM_CRITICAL_SUSPEND:
1413 			/*
1414 			 * We are not allowed to reject a critical suspend.
1415 			 */
1416 			(void)suspend(0);
1417 			break;
1418 		}
1419 	}
1420 }
1421 
1422 static void apm_event_handler(void)
1423 {
1424 	static int pending_count = 4;
1425 	int err;
1426 
1427 	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1428 		if ((apm_info.connection_version > 0x100) &&
1429 		    (pending_count-- <= 0)) {
1430 			pending_count = 4;
1431 			if (debug)
1432 				printk(KERN_DEBUG "apm: setting state busy\n");
1433 			err = set_system_power_state(APM_STATE_BUSY);
1434 			if (err)
1435 				apm_error("busy", err);
1436 		}
1437 	} else
1438 		pending_count = 4;
1439 	check_events();
1440 }
1441 
1442 /*
1443  * This is the APM thread main loop.
1444  */
1445 
1446 static void apm_mainloop(void)
1447 {
1448 	DECLARE_WAITQUEUE(wait, current);
1449 
1450 	add_wait_queue(&apm_waitqueue, &wait);
1451 	set_current_state(TASK_INTERRUPTIBLE);
1452 	for (;;) {
1453 		schedule_timeout(APM_CHECK_TIMEOUT);
1454 		if (kthread_should_stop())
1455 			break;
1456 		/*
1457 		 * Ok, check all events, check for idle (and mark us sleeping
1458 		 * so as not to count towards the load average)..
1459 		 */
1460 		set_current_state(TASK_INTERRUPTIBLE);
1461 		apm_event_handler();
1462 	}
1463 	remove_wait_queue(&apm_waitqueue, &wait);
1464 }
1465 
1466 static int check_apm_user(struct apm_user *as, const char *func)
1467 {
1468 	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1469 		pr_err("%s passed bad filp\n", func);
1470 		return 1;
1471 	}
1472 	return 0;
1473 }
1474 
1475 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1476 {
1477 	struct apm_user *as;
1478 	int i;
1479 	apm_event_t event;
1480 
1481 	as = fp->private_data;
1482 	if (check_apm_user(as, "read"))
1483 		return -EIO;
1484 	if ((int)count < sizeof(apm_event_t))
1485 		return -EINVAL;
1486 	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1487 		return -EAGAIN;
1488 	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1489 	i = count;
1490 	while ((i >= sizeof(event)) && !queue_empty(as)) {
1491 		event = get_queued_event(as);
1492 		if (copy_to_user(buf, &event, sizeof(event))) {
1493 			if (i < count)
1494 				break;
1495 			return -EFAULT;
1496 		}
1497 		switch (event) {
1498 		case APM_SYS_SUSPEND:
1499 		case APM_USER_SUSPEND:
1500 			as->suspends_read++;
1501 			break;
1502 
1503 		case APM_SYS_STANDBY:
1504 		case APM_USER_STANDBY:
1505 			as->standbys_read++;
1506 			break;
1507 		}
1508 		buf += sizeof(event);
1509 		i -= sizeof(event);
1510 	}
1511 	if (i < count)
1512 		return count - i;
1513 	if (signal_pending(current))
1514 		return -ERESTARTSYS;
1515 	return 0;
1516 }
1517 
1518 static unsigned int do_poll(struct file *fp, poll_table *wait)
1519 {
1520 	struct apm_user *as;
1521 
1522 	as = fp->private_data;
1523 	if (check_apm_user(as, "poll"))
1524 		return 0;
1525 	poll_wait(fp, &apm_waitqueue, wait);
1526 	if (!queue_empty(as))
1527 		return POLLIN | POLLRDNORM;
1528 	return 0;
1529 }
1530 
1531 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1532 {
1533 	struct apm_user *as;
1534 	int ret;
1535 
1536 	as = filp->private_data;
1537 	if (check_apm_user(as, "ioctl"))
1538 		return -EIO;
1539 	if (!as->suser || !as->writer)
1540 		return -EPERM;
1541 	switch (cmd) {
1542 	case APM_IOC_STANDBY:
1543 		mutex_lock(&apm_mutex);
1544 		if (as->standbys_read > 0) {
1545 			as->standbys_read--;
1546 			as->standbys_pending--;
1547 			standbys_pending--;
1548 		} else
1549 			queue_event(APM_USER_STANDBY, as);
1550 		if (standbys_pending <= 0)
1551 			standby();
1552 		mutex_unlock(&apm_mutex);
1553 		break;
1554 	case APM_IOC_SUSPEND:
1555 		mutex_lock(&apm_mutex);
1556 		if (as->suspends_read > 0) {
1557 			as->suspends_read--;
1558 			as->suspends_pending--;
1559 			suspends_pending--;
1560 		} else
1561 			queue_event(APM_USER_SUSPEND, as);
1562 		if (suspends_pending <= 0) {
1563 			ret = suspend(1);
1564 			mutex_unlock(&apm_mutex);
1565 		} else {
1566 			as->suspend_wait = 1;
1567 			mutex_unlock(&apm_mutex);
1568 			wait_event_interruptible(apm_suspend_waitqueue,
1569 					as->suspend_wait == 0);
1570 			ret = as->suspend_result;
1571 		}
1572 		return ret;
1573 	default:
1574 		return -ENOTTY;
1575 	}
1576 	return 0;
1577 }
1578 
1579 static int do_release(struct inode *inode, struct file *filp)
1580 {
1581 	struct apm_user *as;
1582 
1583 	as = filp->private_data;
1584 	if (check_apm_user(as, "release"))
1585 		return 0;
1586 	filp->private_data = NULL;
1587 	if (as->standbys_pending > 0) {
1588 		standbys_pending -= as->standbys_pending;
1589 		if (standbys_pending <= 0)
1590 			standby();
1591 	}
1592 	if (as->suspends_pending > 0) {
1593 		suspends_pending -= as->suspends_pending;
1594 		if (suspends_pending <= 0)
1595 			(void) suspend(1);
1596 	}
1597 	spin_lock(&user_list_lock);
1598 	if (user_list == as)
1599 		user_list = as->next;
1600 	else {
1601 		struct apm_user *as1;
1602 
1603 		for (as1 = user_list;
1604 		     (as1 != NULL) && (as1->next != as);
1605 		     as1 = as1->next)
1606 			;
1607 		if (as1 == NULL)
1608 			pr_err("filp not in user list\n");
1609 		else
1610 			as1->next = as->next;
1611 	}
1612 	spin_unlock(&user_list_lock);
1613 	kfree(as);
1614 	return 0;
1615 }
1616 
1617 static int do_open(struct inode *inode, struct file *filp)
1618 {
1619 	struct apm_user *as;
1620 
1621 	as = kmalloc(sizeof(*as), GFP_KERNEL);
1622 	if (as == NULL)
1623 		return -ENOMEM;
1624 
1625 	as->magic = APM_BIOS_MAGIC;
1626 	as->event_tail = as->event_head = 0;
1627 	as->suspends_pending = as->standbys_pending = 0;
1628 	as->suspends_read = as->standbys_read = 0;
1629 	/*
1630 	 * XXX - this is a tiny bit broken, when we consider BSD
1631 	 * process accounting. If the device is opened by root, we
1632 	 * instantly flag that we used superuser privs. Who knows,
1633 	 * we might close the device immediately without doing a
1634 	 * privileged operation -- cevans
1635 	 */
1636 	as->suser = capable(CAP_SYS_ADMIN);
1637 	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1638 	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1639 	spin_lock(&user_list_lock);
1640 	as->next = user_list;
1641 	user_list = as;
1642 	spin_unlock(&user_list_lock);
1643 	filp->private_data = as;
1644 	return 0;
1645 }
1646 
1647 static int proc_apm_show(struct seq_file *m, void *v)
1648 {
1649 	unsigned short	bx;
1650 	unsigned short	cx;
1651 	unsigned short	dx;
1652 	int		error;
1653 	unsigned short  ac_line_status = 0xff;
1654 	unsigned short  battery_status = 0xff;
1655 	unsigned short  battery_flag   = 0xff;
1656 	int		percentage     = -1;
1657 	int             time_units     = -1;
1658 	char            *units         = "?";
1659 
1660 	if ((num_online_cpus() == 1) &&
1661 	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1662 		ac_line_status = (bx >> 8) & 0xff;
1663 		battery_status = bx & 0xff;
1664 		if ((cx & 0xff) != 0xff)
1665 			percentage = cx & 0xff;
1666 
1667 		if (apm_info.connection_version > 0x100) {
1668 			battery_flag = (cx >> 8) & 0xff;
1669 			if (dx != 0xffff) {
1670 				units = (dx & 0x8000) ? "min" : "sec";
1671 				time_units = dx & 0x7fff;
1672 			}
1673 		}
1674 	}
1675 	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1676 	   from the Get Power Status (0x0a) call unless otherwise noted.
1677 
1678 	   0) Linux driver version (this will change if format changes)
1679 	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1680 	   2) APM flags from APM Installation Check (0x00):
1681 	      bit 0: APM_16_BIT_SUPPORT
1682 	      bit 1: APM_32_BIT_SUPPORT
1683 	      bit 2: APM_IDLE_SLOWS_CLOCK
1684 	      bit 3: APM_BIOS_DISABLED
1685 	      bit 4: APM_BIOS_DISENGAGED
1686 	   3) AC line status
1687 	      0x00: Off-line
1688 	      0x01: On-line
1689 	      0x02: On backup power (BIOS >= 1.1 only)
1690 	      0xff: Unknown
1691 	   4) Battery status
1692 	      0x00: High
1693 	      0x01: Low
1694 	      0x02: Critical
1695 	      0x03: Charging
1696 	      0x04: Selected battery not present (BIOS >= 1.2 only)
1697 	      0xff: Unknown
1698 	   5) Battery flag
1699 	      bit 0: High
1700 	      bit 1: Low
1701 	      bit 2: Critical
1702 	      bit 3: Charging
1703 	      bit 7: No system battery
1704 	      0xff: Unknown
1705 	   6) Remaining battery life (percentage of charge):
1706 	      0-100: valid
1707 	      -1: Unknown
1708 	   7) Remaining battery life (time units):
1709 	      Number of remaining minutes or seconds
1710 	      -1: Unknown
1711 	   8) min = minutes; sec = seconds */
1712 
1713 	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1714 		   driver_version,
1715 		   (apm_info.bios.version >> 8) & 0xff,
1716 		   apm_info.bios.version & 0xff,
1717 		   apm_info.bios.flags,
1718 		   ac_line_status,
1719 		   battery_status,
1720 		   battery_flag,
1721 		   percentage,
1722 		   time_units,
1723 		   units);
1724 	return 0;
1725 }
1726 
1727 static int proc_apm_open(struct inode *inode, struct file *file)
1728 {
1729 	return single_open(file, proc_apm_show, NULL);
1730 }
1731 
1732 static const struct file_operations apm_file_ops = {
1733 	.owner		= THIS_MODULE,
1734 	.open		= proc_apm_open,
1735 	.read		= seq_read,
1736 	.llseek		= seq_lseek,
1737 	.release	= single_release,
1738 };
1739 
1740 static int apm(void *unused)
1741 {
1742 	unsigned short	bx;
1743 	unsigned short	cx;
1744 	unsigned short	dx;
1745 	int		error;
1746 	char 		*power_stat;
1747 	char 		*bat_stat;
1748 
1749 	/* 2002/08/01 - WT
1750 	 * This is to avoid random crashes at boot time during initialization
1751 	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1752 	 * Some bioses don't like being called from CPU != 0.
1753 	 * Method suggested by Ingo Molnar.
1754 	 */
1755 	set_cpus_allowed_ptr(current, cpumask_of(0));
1756 	BUG_ON(smp_processor_id() != 0);
1757 
1758 	if (apm_info.connection_version == 0) {
1759 		apm_info.connection_version = apm_info.bios.version;
1760 		if (apm_info.connection_version > 0x100) {
1761 			/*
1762 			 * We only support BIOSs up to version 1.2
1763 			 */
1764 			if (apm_info.connection_version > 0x0102)
1765 				apm_info.connection_version = 0x0102;
1766 			error = apm_driver_version(&apm_info.connection_version);
1767 			if (error != APM_SUCCESS) {
1768 				apm_error("driver version", error);
1769 				/* Fall back to an APM 1.0 connection. */
1770 				apm_info.connection_version = 0x100;
1771 			}
1772 		}
1773 	}
1774 
1775 	if (debug)
1776 		printk(KERN_INFO "apm: Connection version %d.%d\n",
1777 			(apm_info.connection_version >> 8) & 0xff,
1778 			apm_info.connection_version & 0xff);
1779 
1780 #ifdef CONFIG_APM_DO_ENABLE
1781 	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1782 		/*
1783 		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1784 		 * is booted with PM disabled but not in the docking station.
1785 		 * Unfortunate ...
1786 		 */
1787 		error = apm_enable_power_management(1);
1788 		if (error) {
1789 			apm_error("enable power management", error);
1790 			return -1;
1791 		}
1792 	}
1793 #endif
1794 
1795 	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1796 	    && (apm_info.connection_version > 0x0100)) {
1797 		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1798 		if (error) {
1799 			apm_error("engage power management", error);
1800 			return -1;
1801 		}
1802 	}
1803 
1804 	if (debug && (num_online_cpus() == 1 || smp)) {
1805 		error = apm_get_power_status(&bx, &cx, &dx);
1806 		if (error)
1807 			printk(KERN_INFO "apm: power status not available\n");
1808 		else {
1809 			switch ((bx >> 8) & 0xff) {
1810 			case 0:
1811 				power_stat = "off line";
1812 				break;
1813 			case 1:
1814 				power_stat = "on line";
1815 				break;
1816 			case 2:
1817 				power_stat = "on backup power";
1818 				break;
1819 			default:
1820 				power_stat = "unknown";
1821 				break;
1822 			}
1823 			switch (bx & 0xff) {
1824 			case 0:
1825 				bat_stat = "high";
1826 				break;
1827 			case 1:
1828 				bat_stat = "low";
1829 				break;
1830 			case 2:
1831 				bat_stat = "critical";
1832 				break;
1833 			case 3:
1834 				bat_stat = "charging";
1835 				break;
1836 			default:
1837 				bat_stat = "unknown";
1838 				break;
1839 			}
1840 			printk(KERN_INFO
1841 			       "apm: AC %s, battery status %s, battery life ",
1842 			       power_stat, bat_stat);
1843 			if ((cx & 0xff) == 0xff)
1844 				printk("unknown\n");
1845 			else
1846 				printk("%d%%\n", cx & 0xff);
1847 			if (apm_info.connection_version > 0x100) {
1848 				printk(KERN_INFO
1849 				       "apm: battery flag 0x%02x, battery life ",
1850 				       (cx >> 8) & 0xff);
1851 				if (dx == 0xffff)
1852 					printk("unknown\n");
1853 				else
1854 					printk("%d %s\n", dx & 0x7fff,
1855 					       (dx & 0x8000) ?
1856 					       "minutes" : "seconds");
1857 			}
1858 		}
1859 	}
1860 
1861 	/* Install our power off handler.. */
1862 	if (power_off)
1863 		pm_power_off = apm_power_off;
1864 
1865 	if (num_online_cpus() == 1 || smp) {
1866 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1867 		console_blank_hook = apm_console_blank;
1868 #endif
1869 		apm_mainloop();
1870 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1871 		console_blank_hook = NULL;
1872 #endif
1873 	}
1874 
1875 	return 0;
1876 }
1877 
1878 #ifndef MODULE
1879 static int __init apm_setup(char *str)
1880 {
1881 	int invert;
1882 
1883 	while ((str != NULL) && (*str != '\0')) {
1884 		if (strncmp(str, "off", 3) == 0)
1885 			apm_disabled = 1;
1886 		if (strncmp(str, "on", 2) == 0)
1887 			apm_disabled = 0;
1888 		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1889 		    (strncmp(str, "bounce_interval=", 16) == 0))
1890 			bounce_interval = simple_strtol(str + 16, NULL, 0);
1891 		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1892 		    (strncmp(str, "idle_threshold=", 15) == 0))
1893 			idle_threshold = simple_strtol(str + 15, NULL, 0);
1894 		if ((strncmp(str, "idle-period=", 12) == 0) ||
1895 		    (strncmp(str, "idle_period=", 12) == 0))
1896 			idle_period = simple_strtol(str + 12, NULL, 0);
1897 		invert = (strncmp(str, "no-", 3) == 0) ||
1898 			(strncmp(str, "no_", 3) == 0);
1899 		if (invert)
1900 			str += 3;
1901 		if (strncmp(str, "debug", 5) == 0)
1902 			debug = !invert;
1903 		if ((strncmp(str, "power-off", 9) == 0) ||
1904 		    (strncmp(str, "power_off", 9) == 0))
1905 			power_off = !invert;
1906 		if (strncmp(str, "smp", 3) == 0) {
1907 			smp = !invert;
1908 			idle_threshold = 100;
1909 		}
1910 		if ((strncmp(str, "allow-ints", 10) == 0) ||
1911 		    (strncmp(str, "allow_ints", 10) == 0))
1912 			apm_info.allow_ints = !invert;
1913 		if ((strncmp(str, "broken-psr", 10) == 0) ||
1914 		    (strncmp(str, "broken_psr", 10) == 0))
1915 			apm_info.get_power_status_broken = !invert;
1916 		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1917 		    (strncmp(str, "realmode_power_off", 18) == 0))
1918 			apm_info.realmode_power_off = !invert;
1919 		str = strchr(str, ',');
1920 		if (str != NULL)
1921 			str += strspn(str, ", \t");
1922 	}
1923 	return 1;
1924 }
1925 
1926 __setup("apm=", apm_setup);
1927 #endif
1928 
1929 static const struct file_operations apm_bios_fops = {
1930 	.owner		= THIS_MODULE,
1931 	.read		= do_read,
1932 	.poll		= do_poll,
1933 	.unlocked_ioctl	= do_ioctl,
1934 	.open		= do_open,
1935 	.release	= do_release,
1936 	.llseek		= noop_llseek,
1937 };
1938 
1939 static struct miscdevice apm_device = {
1940 	APM_MINOR_DEV,
1941 	"apm_bios",
1942 	&apm_bios_fops
1943 };
1944 
1945 
1946 /* Simple "print if true" callback */
1947 static int __init print_if_true(const struct dmi_system_id *d)
1948 {
1949 	printk("%s\n", d->ident);
1950 	return 0;
1951 }
1952 
1953 /*
1954  * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1955  * disabled before the suspend. Linux used to get terribly confused by that.
1956  */
1957 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1958 {
1959 	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1960 	       "workaround hopefully not needed.\n", d->ident);
1961 	return 0;
1962 }
1963 
1964 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1965 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1966 {
1967 	if (apm_info.realmode_power_off == 0) {
1968 		apm_info.realmode_power_off = 1;
1969 		printk(KERN_INFO "%s bios detected. "
1970 		       "Using realmode poweroff only.\n", d->ident);
1971 	}
1972 	return 0;
1973 }
1974 
1975 /* Some laptops require interrupts to be enabled during APM calls */
1976 static int __init set_apm_ints(const struct dmi_system_id *d)
1977 {
1978 	if (apm_info.allow_ints == 0) {
1979 		apm_info.allow_ints = 1;
1980 		printk(KERN_INFO "%s machine detected. "
1981 		       "Enabling interrupts during APM calls.\n", d->ident);
1982 	}
1983 	return 0;
1984 }
1985 
1986 /* Some APM bioses corrupt memory or just plain do not work */
1987 static int __init apm_is_horked(const struct dmi_system_id *d)
1988 {
1989 	if (apm_info.disabled == 0) {
1990 		apm_info.disabled = 1;
1991 		printk(KERN_INFO "%s machine detected. "
1992 		       "Disabling APM.\n", d->ident);
1993 	}
1994 	return 0;
1995 }
1996 
1997 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1998 {
1999 	if (apm_info.disabled == 0) {
2000 		apm_info.disabled = 1;
2001 		printk(KERN_INFO "%s machine detected. "
2002 		       "Disabling APM.\n", d->ident);
2003 		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
2004 		printk(KERN_INFO "download from support.intel.com\n");
2005 	}
2006 	return 0;
2007 }
2008 
2009 /* Some APM bioses hang on APM idle calls */
2010 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
2011 {
2012 	if (apm_info.forbid_idle == 0) {
2013 		apm_info.forbid_idle = 1;
2014 		printk(KERN_INFO "%s machine detected. "
2015 		       "Disabling APM idle calls.\n", d->ident);
2016 	}
2017 	return 0;
2018 }
2019 
2020 /*
2021  *  Check for clue free BIOS implementations who use
2022  *  the following QA technique
2023  *
2024  *      [ Write BIOS Code ]<------
2025  *               |                ^
2026  *      < Does it Compile >----N--
2027  *               |Y               ^
2028  *	< Does it Boot Win98 >-N--
2029  *               |Y
2030  *           [Ship It]
2031  *
2032  *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2033  *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2034  */
2035 static int __init broken_apm_power(const struct dmi_system_id *d)
2036 {
2037 	apm_info.get_power_status_broken = 1;
2038 	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2039 	       "disabling power status reporting.\n");
2040 	return 0;
2041 }
2042 
2043 /*
2044  * This bios swaps the APM minute reporting bytes over (Many sony laptops
2045  * have this problem).
2046  */
2047 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2048 {
2049 	apm_info.get_power_status_swabinminutes = 1;
2050 	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2051 	       "in minutes and wrong byte order.\n");
2052 	return 0;
2053 }
2054 
2055 static struct dmi_system_id __initdata apm_dmi_table[] = {
2056 	{
2057 		print_if_true,
2058 		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2059 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2060 			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2061 	},
2062 	{	/* Handle problems with APM on the C600 */
2063 		broken_ps2_resume, "Dell Latitude C600",
2064 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2065 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2066 	},
2067 	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2068 		set_apm_ints, "Dell Latitude",
2069 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2070 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2071 	},
2072 	{	/* APM crashes */
2073 		apm_is_horked, "Dell Inspiron 2500",
2074 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2075 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2076 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2077 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2078 	},
2079 	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2080 		set_apm_ints, "Dell Inspiron", {
2081 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2082 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2083 	},
2084 	{	/* Handle problems with APM on Inspiron 5000e */
2085 		broken_apm_power, "Dell Inspiron 5000e",
2086 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2087 			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2088 			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2089 	},
2090 	{	/* Handle problems with APM on Inspiron 2500 */
2091 		broken_apm_power, "Dell Inspiron 2500",
2092 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2093 			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2094 			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2095 	},
2096 	{	/* APM crashes */
2097 		apm_is_horked, "Dell Dimension 4100",
2098 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2099 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2100 			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2101 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2102 	},
2103 	{	/* Allow interrupts during suspend on Compaq Laptops*/
2104 		set_apm_ints, "Compaq 12XL125",
2105 		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2106 			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2107 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2108 			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2109 	},
2110 	{	/* Allow interrupts during APM or the clock goes slow */
2111 		set_apm_ints, "ASUSTeK",
2112 		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2113 			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2114 	},
2115 	{	/* APM blows on shutdown */
2116 		apm_is_horked, "ABIT KX7-333[R]",
2117 		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2118 			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2119 	},
2120 	{	/* APM crashes */
2121 		apm_is_horked, "Trigem Delhi3",
2122 		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2123 			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2124 	},
2125 	{	/* APM crashes */
2126 		apm_is_horked, "Fujitsu-Siemens",
2127 		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2128 			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2129 	},
2130 	{	/* APM crashes */
2131 		apm_is_horked_d850md, "Intel D850MD",
2132 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2133 			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2134 	},
2135 	{	/* APM crashes */
2136 		apm_is_horked, "Intel D810EMO",
2137 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2138 			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2139 	},
2140 	{	/* APM crashes */
2141 		apm_is_horked, "Dell XPS-Z",
2142 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2143 			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2144 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2145 	},
2146 	{	/* APM crashes */
2147 		apm_is_horked, "Sharp PC-PJ/AX",
2148 		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2149 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2150 			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2151 			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2152 	},
2153 	{	/* APM crashes */
2154 		apm_is_horked, "Dell Inspiron 2500",
2155 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2156 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2157 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2158 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2159 	},
2160 	{	/* APM idle hangs */
2161 		apm_likes_to_melt, "Jabil AMD",
2162 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2163 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2164 	},
2165 	{	/* APM idle hangs */
2166 		apm_likes_to_melt, "AMI Bios",
2167 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2168 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2169 	},
2170 	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2171 		swab_apm_power_in_minutes, "Sony VAIO",
2172 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2173 			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2174 			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2175 	},
2176 	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2177 		swab_apm_power_in_minutes, "Sony VAIO",
2178 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2179 			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2180 			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2181 	},
2182 	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2183 		swab_apm_power_in_minutes, "Sony VAIO",
2184 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2185 			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2186 			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2187 	},
2188 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2189 		swab_apm_power_in_minutes, "Sony VAIO",
2190 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2191 			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2192 			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2193 	},
2194 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2195 		swab_apm_power_in_minutes, "Sony VAIO",
2196 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2197 			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2198 			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2199 	},
2200 	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2201 		swab_apm_power_in_minutes, "Sony VAIO",
2202 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2203 			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2204 			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2205 	},
2206 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2207 		swab_apm_power_in_minutes, "Sony VAIO",
2208 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2209 			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2210 			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2211 	},
2212 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2213 		swab_apm_power_in_minutes, "Sony VAIO",
2214 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2215 			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2216 			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2217 	},
2218 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2219 		swab_apm_power_in_minutes, "Sony VAIO",
2220 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2221 			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2222 			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2223 	},
2224 	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2225 		swab_apm_power_in_minutes, "Sony VAIO",
2226 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2227 			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2228 			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2229 	},
2230 
2231 	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2232 		swab_apm_power_in_minutes, "Sony VAIO",
2233 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2234 			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2235 			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2236 	},
2237 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2238 		swab_apm_power_in_minutes, "Sony VAIO",
2239 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2240 			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2241 			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2242 	},
2243 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2244 		swab_apm_power_in_minutes, "Sony VAIO",
2245 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2246 			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2247 			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2248 	},
2249 	{	/* broken PM poweroff bios */
2250 		set_realmode_power_off, "Award Software v4.60 PGMA",
2251 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2252 			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2253 			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2254 	},
2255 
2256 	/* Generic per vendor APM settings  */
2257 
2258 	{	/* Allow interrupts during suspend on IBM laptops */
2259 		set_apm_ints, "IBM",
2260 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2261 	},
2262 
2263 	{ }
2264 };
2265 
2266 /*
2267  * Just start the APM thread. We do NOT want to do APM BIOS
2268  * calls from anything but the APM thread, if for no other reason
2269  * than the fact that we don't trust the APM BIOS. This way,
2270  * most common APM BIOS problems that lead to protection errors
2271  * etc will have at least some level of being contained...
2272  *
2273  * In short, if something bad happens, at least we have a choice
2274  * of just killing the apm thread..
2275  */
2276 static int __init apm_init(void)
2277 {
2278 	struct desc_struct *gdt;
2279 	int err;
2280 
2281 	dmi_check_system(apm_dmi_table);
2282 
2283 	if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2284 		printk(KERN_INFO "apm: BIOS not found.\n");
2285 		return -ENODEV;
2286 	}
2287 	printk(KERN_INFO
2288 	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2289 	       ((apm_info.bios.version >> 8) & 0xff),
2290 	       (apm_info.bios.version & 0xff),
2291 	       apm_info.bios.flags,
2292 	       driver_version);
2293 	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2294 		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2295 		return -ENODEV;
2296 	}
2297 
2298 	if (allow_ints)
2299 		apm_info.allow_ints = 1;
2300 	if (broken_psr)
2301 		apm_info.get_power_status_broken = 1;
2302 	if (realmode_power_off)
2303 		apm_info.realmode_power_off = 1;
2304 	/* User can override, but default is to trust DMI */
2305 	if (apm_disabled != -1)
2306 		apm_info.disabled = apm_disabled;
2307 
2308 	/*
2309 	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2310 	 * but is reportedly a 1.0 BIOS.
2311 	 */
2312 	if (apm_info.bios.version == 0x001)
2313 		apm_info.bios.version = 0x100;
2314 
2315 	/* BIOS < 1.2 doesn't set cseg_16_len */
2316 	if (apm_info.bios.version < 0x102)
2317 		apm_info.bios.cseg_16_len = 0; /* 64k */
2318 
2319 	if (debug) {
2320 		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2321 			apm_info.bios.cseg, apm_info.bios.offset,
2322 			apm_info.bios.cseg_16, apm_info.bios.dseg);
2323 		if (apm_info.bios.version > 0x100)
2324 			printk(" cseg len %x, dseg len %x",
2325 				apm_info.bios.cseg_len,
2326 				apm_info.bios.dseg_len);
2327 		if (apm_info.bios.version > 0x101)
2328 			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2329 		printk("\n");
2330 	}
2331 
2332 	if (apm_info.disabled) {
2333 		pr_notice("disabled on user request.\n");
2334 		return -ENODEV;
2335 	}
2336 	if ((num_online_cpus() > 1) && !power_off && !smp) {
2337 		pr_notice("disabled - APM is not SMP safe.\n");
2338 		apm_info.disabled = 1;
2339 		return -ENODEV;
2340 	}
2341 	if (!acpi_disabled) {
2342 		pr_notice("overridden by ACPI.\n");
2343 		apm_info.disabled = 1;
2344 		return -ENODEV;
2345 	}
2346 
2347 	/*
2348 	 * Set up the long jump entry point to the APM BIOS, which is called
2349 	 * from inline assembly.
2350 	 */
2351 	apm_bios_entry.offset = apm_info.bios.offset;
2352 	apm_bios_entry.segment = APM_CS;
2353 
2354 	/*
2355 	 * The APM 1.1 BIOS is supposed to provide limit information that it
2356 	 * recognizes.  Many machines do this correctly, but many others do
2357 	 * not restrict themselves to their claimed limit.  When this happens,
2358 	 * they will cause a segmentation violation in the kernel at boot time.
2359 	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2360 	 *
2361 	 * Note we only set APM segments on CPU zero, since we pin the APM
2362 	 * code to that CPU.
2363 	 */
2364 	gdt = get_cpu_gdt_table(0);
2365 	set_desc_base(&gdt[APM_CS >> 3],
2366 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2367 	set_desc_base(&gdt[APM_CS_16 >> 3],
2368 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2369 	set_desc_base(&gdt[APM_DS >> 3],
2370 		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2371 
2372 	proc_create("apm", 0, NULL, &apm_file_ops);
2373 
2374 	kapmd_task = kthread_create(apm, NULL, "kapmd");
2375 	if (IS_ERR(kapmd_task)) {
2376 		pr_err("disabled - Unable to start kernel thread\n");
2377 		err = PTR_ERR(kapmd_task);
2378 		kapmd_task = NULL;
2379 		remove_proc_entry("apm", NULL);
2380 		return err;
2381 	}
2382 	wake_up_process(kapmd_task);
2383 
2384 	if (num_online_cpus() > 1 && !smp) {
2385 		printk(KERN_NOTICE
2386 		       "apm: disabled - APM is not SMP safe (power off active).\n");
2387 		return 0;
2388 	}
2389 
2390 	/*
2391 	 * Note we don't actually care if the misc_device cannot be registered.
2392 	 * this driver can do its job without it, even if userspace can't
2393 	 * control it.  just log the error
2394 	 */
2395 	if (misc_register(&apm_device))
2396 		printk(KERN_WARNING "apm: Could not register misc device.\n");
2397 
2398 	if (HZ != 100)
2399 		idle_period = (idle_period * HZ) / 100;
2400 	if (idle_threshold < 100) {
2401 		if (!cpuidle_register_driver(&apm_idle_driver))
2402 			if (cpuidle_register_device(&apm_cpuidle_device))
2403 				cpuidle_unregister_driver(&apm_idle_driver);
2404 	}
2405 
2406 	return 0;
2407 }
2408 
2409 static void __exit apm_exit(void)
2410 {
2411 	int error;
2412 
2413 	cpuidle_unregister_device(&apm_cpuidle_device);
2414 	cpuidle_unregister_driver(&apm_idle_driver);
2415 
2416 	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2417 	    && (apm_info.connection_version > 0x0100)) {
2418 		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2419 		if (error)
2420 			apm_error("disengage power management", error);
2421 	}
2422 	misc_deregister(&apm_device);
2423 	remove_proc_entry("apm", NULL);
2424 	if (power_off)
2425 		pm_power_off = NULL;
2426 	if (kapmd_task) {
2427 		kthread_stop(kapmd_task);
2428 		kapmd_task = NULL;
2429 	}
2430 }
2431 
2432 module_init(apm_init);
2433 module_exit(apm_exit);
2434 
2435 MODULE_AUTHOR("Stephen Rothwell");
2436 MODULE_DESCRIPTION("Advanced Power Management");
2437 MODULE_LICENSE("GPL");
2438 module_param(debug, bool, 0644);
2439 MODULE_PARM_DESC(debug, "Enable debug mode");
2440 module_param(power_off, bool, 0444);
2441 MODULE_PARM_DESC(power_off, "Enable power off");
2442 module_param(bounce_interval, int, 0444);
2443 MODULE_PARM_DESC(bounce_interval,
2444 		"Set the number of ticks to ignore suspend bounces");
2445 module_param(allow_ints, bool, 0444);
2446 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2447 module_param(broken_psr, bool, 0444);
2448 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2449 module_param(realmode_power_off, bool, 0444);
2450 MODULE_PARM_DESC(realmode_power_off,
2451 		"Switch to real mode before powering off");
2452 module_param(idle_threshold, int, 0444);
2453 MODULE_PARM_DESC(idle_threshold,
2454 	"System idle percentage above which to make APM BIOS idle calls");
2455 module_param(idle_period, int, 0444);
2456 MODULE_PARM_DESC(idle_period,
2457 	"Period (in sec/100) over which to caculate the idle percentage");
2458 module_param(smp, bool, 0444);
2459 MODULE_PARM_DESC(smp,
2460 	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2461 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
2462