xref: /openbmc/linux/arch/x86/kernel/apm_32.c (revision 565d76cb)
1 /* -*- linux-c -*-
2  * APM BIOS driver for Linux
3  * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
4  *
5  * Initial development of this driver was funded by NEC Australia P/L
6  *	and NEC Corporation
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the
10  * Free Software Foundation; either version 2, or (at your option) any
11  * later version.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * October 1995, Rik Faith (faith@cs.unc.edu):
19  *    Minor enhancements and updates (to the patch set) for 1.3.x
20  *    Documentation
21  * January 1996, Rik Faith (faith@cs.unc.edu):
22  *    Make /proc/apm easy to format (bump driver version)
23  * March 1996, Rik Faith (faith@cs.unc.edu):
24  *    Prohibit APM BIOS calls unless apm_enabled.
25  *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
26  * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
27  *    Version 1.0 and 1.1
28  * May 1996, Version 1.2
29  * Feb 1998, Version 1.3
30  * Feb 1998, Version 1.4
31  * Aug 1998, Version 1.5
32  * Sep 1998, Version 1.6
33  * Nov 1998, Version 1.7
34  * Jan 1999, Version 1.8
35  * Jan 1999, Version 1.9
36  * Oct 1999, Version 1.10
37  * Nov 1999, Version 1.11
38  * Jan 2000, Version 1.12
39  * Feb 2000, Version 1.13
40  * Nov 2000, Version 1.14
41  * Oct 2001, Version 1.15
42  * Jan 2002, Version 1.16
43  * Oct 2002, Version 1.16ac
44  *
45  * History:
46  *    0.6b: first version in official kernel, Linux 1.3.46
47  *    0.7: changed /proc/apm format, Linux 1.3.58
48  *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
49  *    0.9: only call bios if bios is present, Linux 1.3.72
50  *    1.0: use fixed device number, consolidate /proc/apm into this file,
51  *         Linux 1.3.85
52  *    1.1: support user-space standby and suspend, power off after system
53  *         halted, Linux 1.3.98
54  *    1.2: When resetting RTC after resume, take care so that the time
55  *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
56  *         <jtoth@princeton.edu>); improve interaction between
57  *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
58  *    1.2a:Simple change to stop mysterious bug reports with SMP also added
59  *	   levels to the printk calls. APM is not defined for SMP machines.
60  *         The new replacement for it is, but Linux doesn't yet support this.
61  *         Alan Cox Linux 2.1.55
62  *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
63  *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
64  *         Dean Gaudet <dgaudet@arctic.org>.
65  *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
66  *    1.5: Fix segment register reloading (in case of bad segments saved
67  *         across BIOS call).
68  *         Stephen Rothwell
69  *    1.6: Cope with compiler/assembler differences.
70  *         Only try to turn off the first display device.
71  *         Fix OOPS at power off with no APM BIOS by Jan Echternach
72  *                   <echter@informatik.uni-rostock.de>
73  *         Stephen Rothwell
74  *    1.7: Modify driver's cached copy of the disabled/disengaged flags
75  *         to reflect current state of APM BIOS.
76  *         Chris Rankin <rankinc@bellsouth.net>
77  *         Reset interrupt 0 timer to 100Hz after suspend
78  *         Chad Miller <cmiller@surfsouth.com>
79  *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
80  *         Richard Gooch <rgooch@atnf.csiro.au>
81  *         Allow boot time disabling of APM
82  *         Make boot messages far less verbose by default
83  *         Make asm safer
84  *         Stephen Rothwell
85  *    1.8: Add CONFIG_APM_RTC_IS_GMT
86  *         Richard Gooch <rgooch@atnf.csiro.au>
87  *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
88  *         remove dependency on CONFIG_PROC_FS
89  *         Stephen Rothwell
90  *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
91  *         Try to cope with BIOS's that need to have all display
92  *         devices blanked and not just the first one.
93  *         Ross Paterson <ross@soi.city.ac.uk>
94  *         Fix segment limit setting it has always been wrong as
95  *         the segments needed to have byte granularity.
96  *         Mark a few things __init.
97  *         Add hack to allow power off of SMP systems by popular request.
98  *         Use CONFIG_SMP instead of __SMP__
99  *         Ignore BOUNCES for three seconds.
100  *         Stephen Rothwell
101  *   1.10: Fix for Thinkpad return code.
102  *         Merge 2.2 and 2.3 drivers.
103  *         Remove APM dependencies in arch/i386/kernel/process.c
104  *         Remove APM dependencies in drivers/char/sysrq.c
105  *         Reset time across standby.
106  *         Allow more inititialisation on SMP.
107  *         Remove CONFIG_APM_POWER_OFF and make it boot time
108  *         configurable (default on).
109  *         Make debug only a boot time parameter (remove APM_DEBUG).
110  *         Try to blank all devices on any error.
111  *   1.11: Remove APM dependencies in drivers/char/console.c
112  *         Check nr_running to detect if we are idle (from
113  *         Borislav Deianov <borislav@lix.polytechnique.fr>)
114  *         Fix for bioses that don't zero the top part of the
115  *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
116  *         (reported by Panos Katsaloulis <teras@writeme.com>).
117  *         Real mode power off patch (Walter Hofmann
118  *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
119  *   1.12: Remove CONFIG_SMP as the compiler will optimize
120  *         the code away anyway (smp_num_cpus == 1 in UP)
121  *         noted by Artur Skawina <skawina@geocities.com>.
122  *         Make power off under SMP work again.
123  *         Fix thinko with initial engaging of BIOS.
124  *         Make sure power off only happens on CPU 0
125  *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
126  *         Do error notification to user mode if BIOS calls fail.
127  *         Move entrypoint offset fix to ...boot/setup.S
128  *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
129  *         Remove smp-power-off. SMP users must now specify
130  *         "apm=power-off" on the kernel command line. Suggested
131  *         by Jim Avera <jima@hal.com>, modified by Alan Cox
132  *         <alan@lxorguk.ukuu.org.uk>.
133  *         Register the /proc/apm entry even on SMP so that
134  *         scripts that check for it before doing power off
135  *         work (Jim Avera <jima@hal.com>).
136  *   1.13: Changes for new pm_ interfaces (Andy Henroid
137  *         <andy_henroid@yahoo.com>).
138  *         Modularize the code.
139  *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
140  *         is now the way life works).
141  *         Fix thinko in suspend() (wrong return).
142  *         Notify drivers on critical suspend.
143  *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
144  *         modified by sfr).
145  *         Disable interrupts while we are suspended (Andy Henroid
146  *         <andy_henroid@yahoo.com> fixed by sfr).
147  *         Make power off work on SMP again (Tony Hoyle
148  *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
149  *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
150  *         interval is now configurable.
151  *   1.14: Make connection version persist across module unload/load.
152  *         Enable and engage power management earlier.
153  *         Disengage power management on module unload.
154  *         Changed to use the sysrq-register hack for registering the
155  *         power off function called by magic sysrq based upon discussions
156  *         in irc://irc.openprojects.net/#kernelnewbies
157  *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
158  *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
159  *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
160  *         Work around byte swap bug in one of the Vaio's BIOS's
161  *         (Marc Boucher <marc@mbsi.ca>).
162  *         Exposed the disable flag to dmi so that we can handle known
163  *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
164  *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
165  *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
166  *         If an APM idle fails log it and idle sensibly
167  *   1.15: Don't queue events to clients who open the device O_WRONLY.
168  *         Don't expect replies from clients who open the device O_RDONLY.
169  *         (Idea from Thomas Hood)
170  *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
171  *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
172  *         Notify listeners of standby or suspend events before notifying
173  *         drivers. Return EBUSY to ioctl() if suspend is rejected.
174  *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
175  *         Ignore first resume after we generate our own resume event
176  *         after a suspend (Thomas Hood)
177  *         Daemonize now gets rid of our controlling terminal (sfr).
178  *         CONFIG_APM_CPU_IDLE now just affects the default value of
179  *         idle_threshold (sfr).
180  *         Change name of kernel apm daemon (as it no longer idles) (sfr).
181  *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
182  *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
183  *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
184  *
185  * APM 1.1 Reference:
186  *
187  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
188  *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
189  *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
190  *
191  * [This document is available free from Intel by calling 800.628.8686 (fax
192  * 916.356.6100) or 800.548.4725; or from
193  * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
194  * available from Microsoft by calling 206.882.8080.]
195  *
196  * APM 1.2 Reference:
197  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
198  *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
199  *
200  * [This document is available from Microsoft at:
201  *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
202  */
203 
204 #include <linux/module.h>
205 
206 #include <linux/poll.h>
207 #include <linux/types.h>
208 #include <linux/stddef.h>
209 #include <linux/timer.h>
210 #include <linux/fcntl.h>
211 #include <linux/slab.h>
212 #include <linux/stat.h>
213 #include <linux/proc_fs.h>
214 #include <linux/seq_file.h>
215 #include <linux/miscdevice.h>
216 #include <linux/apm_bios.h>
217 #include <linux/init.h>
218 #include <linux/time.h>
219 #include <linux/sched.h>
220 #include <linux/pm.h>
221 #include <linux/capability.h>
222 #include <linux/device.h>
223 #include <linux/kernel.h>
224 #include <linux/freezer.h>
225 #include <linux/smp.h>
226 #include <linux/dmi.h>
227 #include <linux/suspend.h>
228 #include <linux/kthread.h>
229 #include <linux/jiffies.h>
230 #include <linux/acpi.h>
231 
232 #include <asm/system.h>
233 #include <asm/uaccess.h>
234 #include <asm/desc.h>
235 #include <asm/i8253.h>
236 #include <asm/olpc.h>
237 #include <asm/paravirt.h>
238 #include <asm/reboot.h>
239 
240 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
241 extern int (*console_blank_hook)(int);
242 #endif
243 
244 /*
245  * The apm_bios device is one of the misc char devices.
246  * This is its minor number.
247  */
248 #define	APM_MINOR_DEV	134
249 
250 /*
251  * See Documentation/Config.help for the configuration options.
252  *
253  * Various options can be changed at boot time as follows:
254  * (We allow underscores for compatibility with the modules code)
255  *	apm=on/off			enable/disable APM
256  *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
257  *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
258  *	    [no-]realmode[-_]power[-_]off	switch to real mode before
259  *	    					powering off
260  *	    [no-]debug			log some debugging messages
261  *	    [no-]power[-_]off		power off on shutdown
262  *	    [no-]smp			Use apm even on an SMP box
263  *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
264  *	    				bounces
265  *          idle[-_]threshold=<n>       System idle percentage above which to
266  *                                      make APM BIOS idle calls. Set it to
267  *                                      100 to disable.
268  *          idle[-_]period=<n>          Period (in 1/100s of a second) over
269  *                                      which the idle percentage is
270  *                                      calculated.
271  */
272 
273 /* KNOWN PROBLEM MACHINES:
274  *
275  * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
276  *                         [Confirmed by TI representative]
277  * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
278  *                    [Confirmed by BIOS disassembly]
279  *                    [This may work now ...]
280  * P: Toshiba 1950S: battery life information only gets updated after resume
281  * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
282  * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
283  * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
284  * 	Neale Banks <neale@lowendale.com.au> December 2000
285  *
286  * Legend: U = unusable with APM patches
287  *         P = partially usable with APM patches
288  */
289 
290 /*
291  * Define as 1 to make the driver always call the APM BIOS busy
292  * routine even if the clock was not reported as slowed by the
293  * idle routine.  Otherwise, define as 0.
294  */
295 #define ALWAYS_CALL_BUSY   1
296 
297 /*
298  * Define to make the APM BIOS calls zero all data segment registers (so
299  * that an incorrect BIOS implementation will cause a kernel panic if it
300  * tries to write to arbitrary memory).
301  */
302 #define APM_ZERO_SEGS
303 
304 #include <asm/apm.h>
305 
306 /*
307  * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
308  * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
309  * David Chen <chen@ctpa04.mit.edu>
310  */
311 #undef INIT_TIMER_AFTER_SUSPEND
312 
313 #ifdef INIT_TIMER_AFTER_SUSPEND
314 #include <linux/timex.h>
315 #include <asm/io.h>
316 #include <linux/delay.h>
317 #endif
318 
319 /*
320  * Need to poll the APM BIOS every second
321  */
322 #define APM_CHECK_TIMEOUT	(HZ)
323 
324 /*
325  * Ignore suspend events for this amount of time after a resume
326  */
327 #define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
328 
329 /*
330  * Maximum number of events stored
331  */
332 #define APM_MAX_EVENTS		20
333 
334 /*
335  * The per-file APM data
336  */
337 struct apm_user {
338 	int		magic;
339 	struct apm_user *next;
340 	unsigned int	suser: 1;
341 	unsigned int	writer: 1;
342 	unsigned int	reader: 1;
343 	unsigned int	suspend_wait: 1;
344 	int		suspend_result;
345 	int		suspends_pending;
346 	int		standbys_pending;
347 	int		suspends_read;
348 	int		standbys_read;
349 	int		event_head;
350 	int		event_tail;
351 	apm_event_t	events[APM_MAX_EVENTS];
352 };
353 
354 /*
355  * The magic number in apm_user
356  */
357 #define APM_BIOS_MAGIC		0x4101
358 
359 /*
360  * idle percentage above which bios idle calls are done
361  */
362 #ifdef CONFIG_APM_CPU_IDLE
363 #define DEFAULT_IDLE_THRESHOLD	95
364 #else
365 #define DEFAULT_IDLE_THRESHOLD	100
366 #endif
367 #define DEFAULT_IDLE_PERIOD	(100 / 3)
368 
369 /*
370  * Local variables
371  */
372 static struct {
373 	unsigned long	offset;
374 	unsigned short	segment;
375 } apm_bios_entry;
376 static int clock_slowed;
377 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
378 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
379 static int set_pm_idle;
380 static int suspends_pending;
381 static int standbys_pending;
382 static int ignore_sys_suspend;
383 static int ignore_normal_resume;
384 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
385 
386 static int debug __read_mostly;
387 static int smp __read_mostly;
388 static int apm_disabled = -1;
389 #ifdef CONFIG_SMP
390 static int power_off;
391 #else
392 static int power_off = 1;
393 #endif
394 static int realmode_power_off;
395 #ifdef CONFIG_APM_ALLOW_INTS
396 static int allow_ints = 1;
397 #else
398 static int allow_ints;
399 #endif
400 static int broken_psr;
401 
402 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
403 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
404 static struct apm_user *user_list;
405 static DEFINE_SPINLOCK(user_list_lock);
406 static DEFINE_MUTEX(apm_mutex);
407 
408 /*
409  * Set up a segment that references the real mode segment 0x40
410  * that extends up to the end of page zero (that we have reserved).
411  * This is for buggy BIOS's that refer to (real mode) segment 0x40
412  * even though they are called in protected mode.
413  */
414 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
415 			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
416 
417 static const char driver_version[] = "1.16ac";	/* no spaces */
418 
419 static struct task_struct *kapmd_task;
420 
421 /*
422  *	APM event names taken from the APM 1.2 specification. These are
423  *	the message codes that the BIOS uses to tell us about events
424  */
425 static const char * const apm_event_name[] = {
426 	"system standby",
427 	"system suspend",
428 	"normal resume",
429 	"critical resume",
430 	"low battery",
431 	"power status change",
432 	"update time",
433 	"critical suspend",
434 	"user standby",
435 	"user suspend",
436 	"system standby resume",
437 	"capabilities change"
438 };
439 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
440 
441 typedef struct lookup_t {
442 	int	key;
443 	char 	*msg;
444 } lookup_t;
445 
446 /*
447  *	The BIOS returns a set of standard error codes in AX when the
448  *	carry flag is set.
449  */
450 
451 static const lookup_t error_table[] = {
452 /* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
453 	{ APM_DISABLED,		"Power management disabled" },
454 	{ APM_CONNECTED,	"Real mode interface already connected" },
455 	{ APM_NOT_CONNECTED,	"Interface not connected" },
456 	{ APM_16_CONNECTED,	"16 bit interface already connected" },
457 /* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
458 	{ APM_32_CONNECTED,	"32 bit interface already connected" },
459 	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
460 	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
461 	{ APM_BAD_PARAM,	"Parameter out of range" },
462 	{ APM_NOT_ENGAGED,	"Interface not engaged" },
463 	{ APM_BAD_FUNCTION,     "Function not supported" },
464 	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
465 	{ APM_BAD_STATE,	"Unable to enter requested state" },
466 /* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
467 	{ APM_NO_ERROR,		"BIOS did not set a return code" },
468 	{ APM_NOT_PRESENT,	"No APM present" }
469 };
470 #define ERROR_COUNT	ARRAY_SIZE(error_table)
471 
472 /**
473  *	apm_error	-	display an APM error
474  *	@str: information string
475  *	@err: APM BIOS return code
476  *
477  *	Write a meaningful log entry to the kernel log in the event of
478  *	an APM error.  Note that this also handles (negative) kernel errors.
479  */
480 
481 static void apm_error(char *str, int err)
482 {
483 	int i;
484 
485 	for (i = 0; i < ERROR_COUNT; i++)
486 		if (error_table[i].key == err)
487 			break;
488 	if (i < ERROR_COUNT)
489 		printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
490 	else if (err < 0)
491 		printk(KERN_NOTICE "apm: %s: linux error code %i\n", str, err);
492 	else
493 		printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
494 		       str, err);
495 }
496 
497 /*
498  * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
499  * apm_info.allow_ints, we are being really paranoid here!  Not only
500  * are interrupts disabled, but all the segment registers (except SS)
501  * are saved and zeroed this means that if the BIOS tries to reference
502  * any data without explicitly loading the segment registers, the kernel
503  * will fault immediately rather than have some unforeseen circumstances
504  * for the rest of the kernel.  And it will be very obvious!  :-) Doing
505  * this depends on CS referring to the same physical memory as DS so that
506  * DS can be zeroed before the call. Unfortunately, we can't do anything
507  * about the stack segment/pointer.  Also, we tell the compiler that
508  * everything could change.
509  *
510  * Also, we KNOW that for the non error case of apm_bios_call, there
511  * is no useful data returned in the low order 8 bits of eax.
512  */
513 
514 static inline unsigned long __apm_irq_save(void)
515 {
516 	unsigned long flags;
517 	local_save_flags(flags);
518 	if (apm_info.allow_ints) {
519 		if (irqs_disabled_flags(flags))
520 			local_irq_enable();
521 	} else
522 		local_irq_disable();
523 
524 	return flags;
525 }
526 
527 #define apm_irq_save(flags) \
528 	do { flags = __apm_irq_save(); } while (0)
529 
530 static inline void apm_irq_restore(unsigned long flags)
531 {
532 	if (irqs_disabled_flags(flags))
533 		local_irq_disable();
534 	else if (irqs_disabled())
535 		local_irq_enable();
536 }
537 
538 #ifdef APM_ZERO_SEGS
539 #	define APM_DECL_SEGS \
540 		unsigned int saved_fs; unsigned int saved_gs;
541 #	define APM_DO_SAVE_SEGS \
542 		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
543 #	define APM_DO_RESTORE_SEGS \
544 		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
545 #else
546 #	define APM_DECL_SEGS
547 #	define APM_DO_SAVE_SEGS
548 #	define APM_DO_RESTORE_SEGS
549 #endif
550 
551 struct apm_bios_call {
552 	u32 func;
553 	/* In and out */
554 	u32 ebx;
555 	u32 ecx;
556 	/* Out only */
557 	u32 eax;
558 	u32 edx;
559 	u32 esi;
560 
561 	/* Error: -ENOMEM, or bits 8-15 of eax */
562 	int err;
563 };
564 
565 /**
566  *	__apm_bios_call - Make an APM BIOS 32bit call
567  *	@_call: pointer to struct apm_bios_call.
568  *
569  *	Make an APM call using the 32bit protected mode interface. The
570  *	caller is responsible for knowing if APM BIOS is configured and
571  *	enabled. This call can disable interrupts for a long period of
572  *	time on some laptops.  The return value is in AH and the carry
573  *	flag is loaded into AL.  If there is an error, then the error
574  *	code is returned in AH (bits 8-15 of eax) and this function
575  *	returns non-zero.
576  *
577  *	Note: this makes the call on the current CPU.
578  */
579 static long __apm_bios_call(void *_call)
580 {
581 	APM_DECL_SEGS
582 	unsigned long		flags;
583 	int			cpu;
584 	struct desc_struct	save_desc_40;
585 	struct desc_struct	*gdt;
586 	struct apm_bios_call	*call = _call;
587 
588 	cpu = get_cpu();
589 	BUG_ON(cpu != 0);
590 	gdt = get_cpu_gdt_table(cpu);
591 	save_desc_40 = gdt[0x40 / 8];
592 	gdt[0x40 / 8] = bad_bios_desc;
593 
594 	apm_irq_save(flags);
595 	APM_DO_SAVE_SEGS;
596 	apm_bios_call_asm(call->func, call->ebx, call->ecx,
597 			  &call->eax, &call->ebx, &call->ecx, &call->edx,
598 			  &call->esi);
599 	APM_DO_RESTORE_SEGS;
600 	apm_irq_restore(flags);
601 	gdt[0x40 / 8] = save_desc_40;
602 	put_cpu();
603 
604 	return call->eax & 0xff;
605 }
606 
607 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
608 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
609 {
610 	int ret;
611 
612 	/* Don't bother with work_on_cpu in the common case, so we don't
613 	 * have to worry about OOM or overhead. */
614 	if (get_cpu() == 0) {
615 		ret = fn(call);
616 		put_cpu();
617 	} else {
618 		put_cpu();
619 		ret = work_on_cpu(0, fn, call);
620 	}
621 
622 	/* work_on_cpu can fail with -ENOMEM */
623 	if (ret < 0)
624 		call->err = ret;
625 	else
626 		call->err = (call->eax >> 8) & 0xff;
627 
628 	return ret;
629 }
630 
631 /**
632  *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
633  *	@call: the apm_bios_call registers.
634  *
635  *	If there is an error, it is returned in @call.err.
636  */
637 static int apm_bios_call(struct apm_bios_call *call)
638 {
639 	return on_cpu0(__apm_bios_call, call);
640 }
641 
642 /**
643  *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
644  *	@_call: pointer to struct apm_bios_call.
645  *
646  *	Make a BIOS call that returns one value only, or just status.
647  *	If there is an error, then the error code is returned in AH
648  *	(bits 8-15 of eax) and this function returns non-zero (it can
649  *	also return -ENOMEM). This is used for simpler BIOS operations.
650  *	This call may hold interrupts off for a long time on some laptops.
651  *
652  *	Note: this makes the call on the current CPU.
653  */
654 static long __apm_bios_call_simple(void *_call)
655 {
656 	u8			error;
657 	APM_DECL_SEGS
658 	unsigned long		flags;
659 	int			cpu;
660 	struct desc_struct	save_desc_40;
661 	struct desc_struct	*gdt;
662 	struct apm_bios_call	*call = _call;
663 
664 	cpu = get_cpu();
665 	BUG_ON(cpu != 0);
666 	gdt = get_cpu_gdt_table(cpu);
667 	save_desc_40 = gdt[0x40 / 8];
668 	gdt[0x40 / 8] = bad_bios_desc;
669 
670 	apm_irq_save(flags);
671 	APM_DO_SAVE_SEGS;
672 	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
673 					 &call->eax);
674 	APM_DO_RESTORE_SEGS;
675 	apm_irq_restore(flags);
676 	gdt[0x40 / 8] = save_desc_40;
677 	put_cpu();
678 	return error;
679 }
680 
681 /**
682  *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
683  *	@func: APM function to invoke
684  *	@ebx_in: EBX register value for BIOS call
685  *	@ecx_in: ECX register value for BIOS call
686  *	@eax: EAX register on return from the BIOS call
687  *	@err: bits
688  *
689  *	Make a BIOS call that returns one value only, or just status.
690  *	If there is an error, then the error code is returned in @err
691  *	and this function returns non-zero. This is used for simpler
692  *	BIOS operations.  This call may hold interrupts off for a long
693  *	time on some laptops.
694  */
695 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
696 				int *err)
697 {
698 	struct apm_bios_call call;
699 	int ret;
700 
701 	call.func = func;
702 	call.ebx = ebx_in;
703 	call.ecx = ecx_in;
704 
705 	ret = on_cpu0(__apm_bios_call_simple, &call);
706 	*eax = call.eax;
707 	*err = call.err;
708 	return ret;
709 }
710 
711 /**
712  *	apm_driver_version	-	APM driver version
713  *	@val:	loaded with the APM version on return
714  *
715  *	Retrieve the APM version supported by the BIOS. This is only
716  *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
717  *	probably present.
718  *
719  *	On entry val should point to a value indicating the APM driver
720  *	version with the high byte being the major and the low byte the
721  *	minor number both in BCD
722  *
723  *	On return it will hold the BIOS revision supported in the
724  *	same format.
725  */
726 
727 static int apm_driver_version(u_short *val)
728 {
729 	u32 eax;
730 	int err;
731 
732 	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
733 		return err;
734 	*val = eax;
735 	return APM_SUCCESS;
736 }
737 
738 /**
739  *	apm_get_event	-	get an APM event from the BIOS
740  *	@event: pointer to the event
741  *	@info: point to the event information
742  *
743  *	The APM BIOS provides a polled information for event
744  *	reporting. The BIOS expects to be polled at least every second
745  *	when events are pending. When a message is found the caller should
746  *	poll until no more messages are present.  However, this causes
747  *	problems on some laptops where a suspend event notification is
748  *	not cleared until it is acknowledged.
749  *
750  *	Additional information is returned in the info pointer, providing
751  *	that APM 1.2 is in use. If no messges are pending the value 0x80
752  *	is returned (No power management events pending).
753  */
754 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
755 {
756 	struct apm_bios_call call;
757 
758 	call.func = APM_FUNC_GET_EVENT;
759 	call.ebx = call.ecx = 0;
760 
761 	if (apm_bios_call(&call))
762 		return call.err;
763 
764 	*event = call.ebx;
765 	if (apm_info.connection_version < 0x0102)
766 		*info = ~0; /* indicate info not valid */
767 	else
768 		*info = call.ecx;
769 	return APM_SUCCESS;
770 }
771 
772 /**
773  *	set_power_state	-	set the power management state
774  *	@what: which items to transition
775  *	@state: state to transition to
776  *
777  *	Request an APM change of state for one or more system devices. The
778  *	processor state must be transitioned last of all. what holds the
779  *	class of device in the upper byte and the device number (0xFF for
780  *	all) for the object to be transitioned.
781  *
782  *	The state holds the state to transition to, which may in fact
783  *	be an acceptance of a BIOS requested state change.
784  */
785 
786 static int set_power_state(u_short what, u_short state)
787 {
788 	u32 eax;
789 	int err;
790 
791 	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
792 		return err;
793 	return APM_SUCCESS;
794 }
795 
796 /**
797  *	set_system_power_state - set system wide power state
798  *	@state: which state to enter
799  *
800  *	Transition the entire system into a new APM power state.
801  */
802 
803 static int set_system_power_state(u_short state)
804 {
805 	return set_power_state(APM_DEVICE_ALL, state);
806 }
807 
808 /**
809  *	apm_do_idle	-	perform power saving
810  *
811  *	This function notifies the BIOS that the processor is (in the view
812  *	of the OS) idle. It returns -1 in the event that the BIOS refuses
813  *	to handle the idle request. On a success the function returns 1
814  *	if the BIOS did clock slowing or 0 otherwise.
815  */
816 
817 static int apm_do_idle(void)
818 {
819 	u32 eax;
820 	u8 ret = 0;
821 	int idled = 0;
822 	int polling;
823 	int err = 0;
824 
825 	polling = !!(current_thread_info()->status & TS_POLLING);
826 	if (polling) {
827 		current_thread_info()->status &= ~TS_POLLING;
828 		/*
829 		 * TS_POLLING-cleared state must be visible before we
830 		 * test NEED_RESCHED:
831 		 */
832 		smp_mb();
833 	}
834 	if (!need_resched()) {
835 		idled = 1;
836 		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
837 	}
838 	if (polling)
839 		current_thread_info()->status |= TS_POLLING;
840 
841 	if (!idled)
842 		return 0;
843 
844 	if (ret) {
845 		static unsigned long t;
846 
847 		/* This always fails on some SMP boards running UP kernels.
848 		 * Only report the failure the first 5 times.
849 		 */
850 		if (++t < 5) {
851 			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
852 			t = jiffies;
853 		}
854 		return -1;
855 	}
856 	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
857 	return clock_slowed;
858 }
859 
860 /**
861  *	apm_do_busy	-	inform the BIOS the CPU is busy
862  *
863  *	Request that the BIOS brings the CPU back to full performance.
864  */
865 
866 static void apm_do_busy(void)
867 {
868 	u32 dummy;
869 	int err;
870 
871 	if (clock_slowed || ALWAYS_CALL_BUSY) {
872 		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
873 		clock_slowed = 0;
874 	}
875 }
876 
877 /*
878  * If no process has really been interested in
879  * the CPU for some time, we want to call BIOS
880  * power management - we probably want
881  * to conserve power.
882  */
883 #define IDLE_CALC_LIMIT	(HZ * 100)
884 #define IDLE_LEAKY_MAX	16
885 
886 static void (*original_pm_idle)(void) __read_mostly;
887 
888 /**
889  * apm_cpu_idle		-	cpu idling for APM capable Linux
890  *
891  * This is the idling function the kernel executes when APM is available. It
892  * tries to do BIOS powermanagement based on the average system idle time.
893  * Furthermore it calls the system default idle routine.
894  */
895 
896 static void apm_cpu_idle(void)
897 {
898 	static int use_apm_idle; /* = 0 */
899 	static unsigned int last_jiffies; /* = 0 */
900 	static unsigned int last_stime; /* = 0 */
901 
902 	int apm_idle_done = 0;
903 	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
904 	unsigned int bucket;
905 
906 recalc:
907 	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
908 		use_apm_idle = 0;
909 		last_jiffies = jiffies;
910 		last_stime = current->stime;
911 	} else if (jiffies_since_last_check > idle_period) {
912 		unsigned int idle_percentage;
913 
914 		idle_percentage = current->stime - last_stime;
915 		idle_percentage *= 100;
916 		idle_percentage /= jiffies_since_last_check;
917 		use_apm_idle = (idle_percentage > idle_threshold);
918 		if (apm_info.forbid_idle)
919 			use_apm_idle = 0;
920 		last_jiffies = jiffies;
921 		last_stime = current->stime;
922 	}
923 
924 	bucket = IDLE_LEAKY_MAX;
925 
926 	while (!need_resched()) {
927 		if (use_apm_idle) {
928 			unsigned int t;
929 
930 			t = jiffies;
931 			switch (apm_do_idle()) {
932 			case 0:
933 				apm_idle_done = 1;
934 				if (t != jiffies) {
935 					if (bucket) {
936 						bucket = IDLE_LEAKY_MAX;
937 						continue;
938 					}
939 				} else if (bucket) {
940 					bucket--;
941 					continue;
942 				}
943 				break;
944 			case 1:
945 				apm_idle_done = 1;
946 				break;
947 			default: /* BIOS refused */
948 				break;
949 			}
950 		}
951 		if (original_pm_idle)
952 			original_pm_idle();
953 		else
954 			default_idle();
955 		local_irq_disable();
956 		jiffies_since_last_check = jiffies - last_jiffies;
957 		if (jiffies_since_last_check > idle_period)
958 			goto recalc;
959 	}
960 
961 	if (apm_idle_done)
962 		apm_do_busy();
963 
964 	local_irq_enable();
965 }
966 
967 /**
968  *	apm_power_off	-	ask the BIOS to power off
969  *
970  *	Handle the power off sequence. This is the one piece of code we
971  *	will execute even on SMP machines. In order to deal with BIOS
972  *	bugs we support real mode APM BIOS power off calls. We also make
973  *	the SMP call on CPU0 as some systems will only honour this call
974  *	on their first cpu.
975  */
976 
977 static void apm_power_off(void)
978 {
979 	/* Some bioses don't like being called from CPU != 0 */
980 	if (apm_info.realmode_power_off) {
981 		set_cpus_allowed_ptr(current, cpumask_of(0));
982 		machine_real_restart(MRR_APM);
983 	} else {
984 		(void)set_system_power_state(APM_STATE_OFF);
985 	}
986 }
987 
988 #ifdef CONFIG_APM_DO_ENABLE
989 
990 /**
991  *	apm_enable_power_management - enable BIOS APM power management
992  *	@enable: enable yes/no
993  *
994  *	Enable or disable the APM BIOS power services.
995  */
996 
997 static int apm_enable_power_management(int enable)
998 {
999 	u32 eax;
1000 	int err;
1001 
1002 	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1003 		return APM_NOT_ENGAGED;
1004 	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1005 				 enable, &eax, &err))
1006 		return err;
1007 	if (enable)
1008 		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1009 	else
1010 		apm_info.bios.flags |= APM_BIOS_DISABLED;
1011 	return APM_SUCCESS;
1012 }
1013 #endif
1014 
1015 /**
1016  *	apm_get_power_status	-	get current power state
1017  *	@status: returned status
1018  *	@bat: battery info
1019  *	@life: estimated life
1020  *
1021  *	Obtain the current power status from the APM BIOS. We return a
1022  *	status which gives the rough battery status, and current power
1023  *	source. The bat value returned give an estimate as a percentage
1024  *	of life and a status value for the battery. The estimated life
1025  *	if reported is a lifetime in secodnds/minutes at current powwer
1026  *	consumption.
1027  */
1028 
1029 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1030 {
1031 	struct apm_bios_call call;
1032 
1033 	call.func = APM_FUNC_GET_STATUS;
1034 	call.ebx = APM_DEVICE_ALL;
1035 	call.ecx = 0;
1036 
1037 	if (apm_info.get_power_status_broken)
1038 		return APM_32_UNSUPPORTED;
1039 	if (apm_bios_call(&call))
1040 		return call.err;
1041 	*status = call.ebx;
1042 	*bat = call.ecx;
1043 	if (apm_info.get_power_status_swabinminutes) {
1044 		*life = swab16((u16)call.edx);
1045 		*life |= 0x8000;
1046 	} else
1047 		*life = call.edx;
1048 	return APM_SUCCESS;
1049 }
1050 
1051 #if 0
1052 static int apm_get_battery_status(u_short which, u_short *status,
1053 				  u_short *bat, u_short *life, u_short *nbat)
1054 {
1055 	u32 eax;
1056 	u32 ebx;
1057 	u32 ecx;
1058 	u32 edx;
1059 	u32 esi;
1060 
1061 	if (apm_info.connection_version < 0x0102) {
1062 		/* pretend we only have one battery. */
1063 		if (which != 1)
1064 			return APM_BAD_DEVICE;
1065 		*nbat = 1;
1066 		return apm_get_power_status(status, bat, life);
1067 	}
1068 
1069 	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1070 			  &ebx, &ecx, &edx, &esi))
1071 		return (eax >> 8) & 0xff;
1072 	*status = ebx;
1073 	*bat = ecx;
1074 	*life = edx;
1075 	*nbat = esi;
1076 	return APM_SUCCESS;
1077 }
1078 #endif
1079 
1080 /**
1081  *	apm_engage_power_management	-	enable PM on a device
1082  *	@device: identity of device
1083  *	@enable: on/off
1084  *
1085  *	Activate or deactive power management on either a specific device
1086  *	or the entire system (%APM_DEVICE_ALL).
1087  */
1088 
1089 static int apm_engage_power_management(u_short device, int enable)
1090 {
1091 	u32 eax;
1092 	int err;
1093 
1094 	if ((enable == 0) && (device == APM_DEVICE_ALL)
1095 	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1096 		return APM_DISABLED;
1097 	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1098 				 &eax, &err))
1099 		return err;
1100 	if (device == APM_DEVICE_ALL) {
1101 		if (enable)
1102 			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1103 		else
1104 			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1105 	}
1106 	return APM_SUCCESS;
1107 }
1108 
1109 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1110 
1111 /**
1112  *	apm_console_blank	-	blank the display
1113  *	@blank: on/off
1114  *
1115  *	Attempt to blank the console, firstly by blanking just video device
1116  *	zero, and if that fails (some BIOSes don't support it) then it blanks
1117  *	all video devices. Typically the BIOS will do laptop backlight and
1118  *	monitor powerdown for us.
1119  */
1120 
1121 static int apm_console_blank(int blank)
1122 {
1123 	int error = APM_NOT_ENGAGED; /* silence gcc */
1124 	int i;
1125 	u_short state;
1126 	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1127 
1128 	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1129 
1130 	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1131 		error = set_power_state(dev[i], state);
1132 
1133 		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1134 			return 1;
1135 
1136 		if (error == APM_NOT_ENGAGED)
1137 			break;
1138 	}
1139 
1140 	if (error == APM_NOT_ENGAGED) {
1141 		static int tried;
1142 		int eng_error;
1143 		if (tried++ == 0) {
1144 			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1145 			if (eng_error) {
1146 				apm_error("set display", error);
1147 				apm_error("engage interface", eng_error);
1148 				return 0;
1149 			} else
1150 				return apm_console_blank(blank);
1151 		}
1152 	}
1153 	apm_error("set display", error);
1154 	return 0;
1155 }
1156 #endif
1157 
1158 static int queue_empty(struct apm_user *as)
1159 {
1160 	return as->event_head == as->event_tail;
1161 }
1162 
1163 static apm_event_t get_queued_event(struct apm_user *as)
1164 {
1165 	if (++as->event_tail >= APM_MAX_EVENTS)
1166 		as->event_tail = 0;
1167 	return as->events[as->event_tail];
1168 }
1169 
1170 static void queue_event(apm_event_t event, struct apm_user *sender)
1171 {
1172 	struct apm_user *as;
1173 
1174 	spin_lock(&user_list_lock);
1175 	if (user_list == NULL)
1176 		goto out;
1177 	for (as = user_list; as != NULL; as = as->next) {
1178 		if ((as == sender) || (!as->reader))
1179 			continue;
1180 		if (++as->event_head >= APM_MAX_EVENTS)
1181 			as->event_head = 0;
1182 
1183 		if (as->event_head == as->event_tail) {
1184 			static int notified;
1185 
1186 			if (notified++ == 0)
1187 			    printk(KERN_ERR "apm: an event queue overflowed\n");
1188 			if (++as->event_tail >= APM_MAX_EVENTS)
1189 				as->event_tail = 0;
1190 		}
1191 		as->events[as->event_head] = event;
1192 		if (!as->suser || !as->writer)
1193 			continue;
1194 		switch (event) {
1195 		case APM_SYS_SUSPEND:
1196 		case APM_USER_SUSPEND:
1197 			as->suspends_pending++;
1198 			suspends_pending++;
1199 			break;
1200 
1201 		case APM_SYS_STANDBY:
1202 		case APM_USER_STANDBY:
1203 			as->standbys_pending++;
1204 			standbys_pending++;
1205 			break;
1206 		}
1207 	}
1208 	wake_up_interruptible(&apm_waitqueue);
1209 out:
1210 	spin_unlock(&user_list_lock);
1211 }
1212 
1213 static void reinit_timer(void)
1214 {
1215 #ifdef INIT_TIMER_AFTER_SUSPEND
1216 	unsigned long flags;
1217 
1218 	raw_spin_lock_irqsave(&i8253_lock, flags);
1219 	/* set the clock to HZ */
1220 	outb_pit(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1221 	udelay(10);
1222 	outb_pit(LATCH & 0xff, PIT_CH0);	/* LSB */
1223 	udelay(10);
1224 	outb_pit(LATCH >> 8, PIT_CH0);	/* MSB */
1225 	udelay(10);
1226 	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1227 #endif
1228 }
1229 
1230 static int suspend(int vetoable)
1231 {
1232 	int err;
1233 	struct apm_user	*as;
1234 
1235 	dpm_suspend_start(PMSG_SUSPEND);
1236 
1237 	dpm_suspend_noirq(PMSG_SUSPEND);
1238 
1239 	local_irq_disable();
1240 	sysdev_suspend(PMSG_SUSPEND);
1241 
1242 	local_irq_enable();
1243 
1244 	save_processor_state();
1245 	err = set_system_power_state(APM_STATE_SUSPEND);
1246 	ignore_normal_resume = 1;
1247 	restore_processor_state();
1248 
1249 	local_irq_disable();
1250 	reinit_timer();
1251 
1252 	if (err == APM_NO_ERROR)
1253 		err = APM_SUCCESS;
1254 	if (err != APM_SUCCESS)
1255 		apm_error("suspend", err);
1256 	err = (err == APM_SUCCESS) ? 0 : -EIO;
1257 
1258 	sysdev_resume();
1259 	local_irq_enable();
1260 
1261 	dpm_resume_noirq(PMSG_RESUME);
1262 
1263 	dpm_resume_end(PMSG_RESUME);
1264 	queue_event(APM_NORMAL_RESUME, NULL);
1265 	spin_lock(&user_list_lock);
1266 	for (as = user_list; as != NULL; as = as->next) {
1267 		as->suspend_wait = 0;
1268 		as->suspend_result = err;
1269 	}
1270 	spin_unlock(&user_list_lock);
1271 	wake_up_interruptible(&apm_suspend_waitqueue);
1272 	return err;
1273 }
1274 
1275 static void standby(void)
1276 {
1277 	int err;
1278 
1279 	dpm_suspend_noirq(PMSG_SUSPEND);
1280 
1281 	local_irq_disable();
1282 	sysdev_suspend(PMSG_SUSPEND);
1283 	local_irq_enable();
1284 
1285 	err = set_system_power_state(APM_STATE_STANDBY);
1286 	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1287 		apm_error("standby", err);
1288 
1289 	local_irq_disable();
1290 	sysdev_resume();
1291 	local_irq_enable();
1292 
1293 	dpm_resume_noirq(PMSG_RESUME);
1294 }
1295 
1296 static apm_event_t get_event(void)
1297 {
1298 	int error;
1299 	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1300 	apm_eventinfo_t	info;
1301 
1302 	static int notified;
1303 
1304 	/* we don't use the eventinfo */
1305 	error = apm_get_event(&event, &info);
1306 	if (error == APM_SUCCESS)
1307 		return event;
1308 
1309 	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1310 		apm_error("get_event", error);
1311 
1312 	return 0;
1313 }
1314 
1315 static void check_events(void)
1316 {
1317 	apm_event_t event;
1318 	static unsigned long last_resume;
1319 	static int ignore_bounce;
1320 
1321 	while ((event = get_event()) != 0) {
1322 		if (debug) {
1323 			if (event <= NR_APM_EVENT_NAME)
1324 				printk(KERN_DEBUG "apm: received %s notify\n",
1325 				       apm_event_name[event - 1]);
1326 			else
1327 				printk(KERN_DEBUG "apm: received unknown "
1328 				       "event 0x%02x\n", event);
1329 		}
1330 		if (ignore_bounce
1331 		    && (time_after(jiffies, last_resume + bounce_interval)))
1332 			ignore_bounce = 0;
1333 
1334 		switch (event) {
1335 		case APM_SYS_STANDBY:
1336 		case APM_USER_STANDBY:
1337 			queue_event(event, NULL);
1338 			if (standbys_pending <= 0)
1339 				standby();
1340 			break;
1341 
1342 		case APM_USER_SUSPEND:
1343 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1344 			if (apm_info.connection_version > 0x100)
1345 				set_system_power_state(APM_STATE_REJECT);
1346 			break;
1347 #endif
1348 		case APM_SYS_SUSPEND:
1349 			if (ignore_bounce) {
1350 				if (apm_info.connection_version > 0x100)
1351 					set_system_power_state(APM_STATE_REJECT);
1352 				break;
1353 			}
1354 			/*
1355 			 * If we are already processing a SUSPEND,
1356 			 * then further SUSPEND events from the BIOS
1357 			 * will be ignored.  We also return here to
1358 			 * cope with the fact that the Thinkpads keep
1359 			 * sending a SUSPEND event until something else
1360 			 * happens!
1361 			 */
1362 			if (ignore_sys_suspend)
1363 				return;
1364 			ignore_sys_suspend = 1;
1365 			queue_event(event, NULL);
1366 			if (suspends_pending <= 0)
1367 				(void) suspend(1);
1368 			break;
1369 
1370 		case APM_NORMAL_RESUME:
1371 		case APM_CRITICAL_RESUME:
1372 		case APM_STANDBY_RESUME:
1373 			ignore_sys_suspend = 0;
1374 			last_resume = jiffies;
1375 			ignore_bounce = 1;
1376 			if ((event != APM_NORMAL_RESUME)
1377 			    || (ignore_normal_resume == 0)) {
1378 				dpm_resume_end(PMSG_RESUME);
1379 				queue_event(event, NULL);
1380 			}
1381 			ignore_normal_resume = 0;
1382 			break;
1383 
1384 		case APM_CAPABILITY_CHANGE:
1385 		case APM_LOW_BATTERY:
1386 		case APM_POWER_STATUS_CHANGE:
1387 			queue_event(event, NULL);
1388 			/* If needed, notify drivers here */
1389 			break;
1390 
1391 		case APM_UPDATE_TIME:
1392 			break;
1393 
1394 		case APM_CRITICAL_SUSPEND:
1395 			/*
1396 			 * We are not allowed to reject a critical suspend.
1397 			 */
1398 			(void)suspend(0);
1399 			break;
1400 		}
1401 	}
1402 }
1403 
1404 static void apm_event_handler(void)
1405 {
1406 	static int pending_count = 4;
1407 	int err;
1408 
1409 	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1410 		if ((apm_info.connection_version > 0x100) &&
1411 		    (pending_count-- <= 0)) {
1412 			pending_count = 4;
1413 			if (debug)
1414 				printk(KERN_DEBUG "apm: setting state busy\n");
1415 			err = set_system_power_state(APM_STATE_BUSY);
1416 			if (err)
1417 				apm_error("busy", err);
1418 		}
1419 	} else
1420 		pending_count = 4;
1421 	check_events();
1422 }
1423 
1424 /*
1425  * This is the APM thread main loop.
1426  */
1427 
1428 static void apm_mainloop(void)
1429 {
1430 	DECLARE_WAITQUEUE(wait, current);
1431 
1432 	add_wait_queue(&apm_waitqueue, &wait);
1433 	set_current_state(TASK_INTERRUPTIBLE);
1434 	for (;;) {
1435 		schedule_timeout(APM_CHECK_TIMEOUT);
1436 		if (kthread_should_stop())
1437 			break;
1438 		/*
1439 		 * Ok, check all events, check for idle (and mark us sleeping
1440 		 * so as not to count towards the load average)..
1441 		 */
1442 		set_current_state(TASK_INTERRUPTIBLE);
1443 		apm_event_handler();
1444 	}
1445 	remove_wait_queue(&apm_waitqueue, &wait);
1446 }
1447 
1448 static int check_apm_user(struct apm_user *as, const char *func)
1449 {
1450 	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1451 		printk(KERN_ERR "apm: %s passed bad filp\n", func);
1452 		return 1;
1453 	}
1454 	return 0;
1455 }
1456 
1457 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1458 {
1459 	struct apm_user *as;
1460 	int i;
1461 	apm_event_t event;
1462 
1463 	as = fp->private_data;
1464 	if (check_apm_user(as, "read"))
1465 		return -EIO;
1466 	if ((int)count < sizeof(apm_event_t))
1467 		return -EINVAL;
1468 	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1469 		return -EAGAIN;
1470 	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1471 	i = count;
1472 	while ((i >= sizeof(event)) && !queue_empty(as)) {
1473 		event = get_queued_event(as);
1474 		if (copy_to_user(buf, &event, sizeof(event))) {
1475 			if (i < count)
1476 				break;
1477 			return -EFAULT;
1478 		}
1479 		switch (event) {
1480 		case APM_SYS_SUSPEND:
1481 		case APM_USER_SUSPEND:
1482 			as->suspends_read++;
1483 			break;
1484 
1485 		case APM_SYS_STANDBY:
1486 		case APM_USER_STANDBY:
1487 			as->standbys_read++;
1488 			break;
1489 		}
1490 		buf += sizeof(event);
1491 		i -= sizeof(event);
1492 	}
1493 	if (i < count)
1494 		return count - i;
1495 	if (signal_pending(current))
1496 		return -ERESTARTSYS;
1497 	return 0;
1498 }
1499 
1500 static unsigned int do_poll(struct file *fp, poll_table *wait)
1501 {
1502 	struct apm_user *as;
1503 
1504 	as = fp->private_data;
1505 	if (check_apm_user(as, "poll"))
1506 		return 0;
1507 	poll_wait(fp, &apm_waitqueue, wait);
1508 	if (!queue_empty(as))
1509 		return POLLIN | POLLRDNORM;
1510 	return 0;
1511 }
1512 
1513 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1514 {
1515 	struct apm_user *as;
1516 	int ret;
1517 
1518 	as = filp->private_data;
1519 	if (check_apm_user(as, "ioctl"))
1520 		return -EIO;
1521 	if (!as->suser || !as->writer)
1522 		return -EPERM;
1523 	switch (cmd) {
1524 	case APM_IOC_STANDBY:
1525 		mutex_lock(&apm_mutex);
1526 		if (as->standbys_read > 0) {
1527 			as->standbys_read--;
1528 			as->standbys_pending--;
1529 			standbys_pending--;
1530 		} else
1531 			queue_event(APM_USER_STANDBY, as);
1532 		if (standbys_pending <= 0)
1533 			standby();
1534 		mutex_unlock(&apm_mutex);
1535 		break;
1536 	case APM_IOC_SUSPEND:
1537 		mutex_lock(&apm_mutex);
1538 		if (as->suspends_read > 0) {
1539 			as->suspends_read--;
1540 			as->suspends_pending--;
1541 			suspends_pending--;
1542 		} else
1543 			queue_event(APM_USER_SUSPEND, as);
1544 		if (suspends_pending <= 0) {
1545 			ret = suspend(1);
1546 			mutex_unlock(&apm_mutex);
1547 		} else {
1548 			as->suspend_wait = 1;
1549 			mutex_unlock(&apm_mutex);
1550 			wait_event_interruptible(apm_suspend_waitqueue,
1551 					as->suspend_wait == 0);
1552 			ret = as->suspend_result;
1553 		}
1554 		return ret;
1555 	default:
1556 		return -ENOTTY;
1557 	}
1558 	return 0;
1559 }
1560 
1561 static int do_release(struct inode *inode, struct file *filp)
1562 {
1563 	struct apm_user *as;
1564 
1565 	as = filp->private_data;
1566 	if (check_apm_user(as, "release"))
1567 		return 0;
1568 	filp->private_data = NULL;
1569 	if (as->standbys_pending > 0) {
1570 		standbys_pending -= as->standbys_pending;
1571 		if (standbys_pending <= 0)
1572 			standby();
1573 	}
1574 	if (as->suspends_pending > 0) {
1575 		suspends_pending -= as->suspends_pending;
1576 		if (suspends_pending <= 0)
1577 			(void) suspend(1);
1578 	}
1579 	spin_lock(&user_list_lock);
1580 	if (user_list == as)
1581 		user_list = as->next;
1582 	else {
1583 		struct apm_user *as1;
1584 
1585 		for (as1 = user_list;
1586 		     (as1 != NULL) && (as1->next != as);
1587 		     as1 = as1->next)
1588 			;
1589 		if (as1 == NULL)
1590 			printk(KERN_ERR "apm: filp not in user list\n");
1591 		else
1592 			as1->next = as->next;
1593 	}
1594 	spin_unlock(&user_list_lock);
1595 	kfree(as);
1596 	return 0;
1597 }
1598 
1599 static int do_open(struct inode *inode, struct file *filp)
1600 {
1601 	struct apm_user *as;
1602 
1603 	as = kmalloc(sizeof(*as), GFP_KERNEL);
1604 	if (as == NULL) {
1605 		printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1606 		       sizeof(*as));
1607 		return -ENOMEM;
1608 	}
1609 	as->magic = APM_BIOS_MAGIC;
1610 	as->event_tail = as->event_head = 0;
1611 	as->suspends_pending = as->standbys_pending = 0;
1612 	as->suspends_read = as->standbys_read = 0;
1613 	/*
1614 	 * XXX - this is a tiny bit broken, when we consider BSD
1615 	 * process accounting. If the device is opened by root, we
1616 	 * instantly flag that we used superuser privs. Who knows,
1617 	 * we might close the device immediately without doing a
1618 	 * privileged operation -- cevans
1619 	 */
1620 	as->suser = capable(CAP_SYS_ADMIN);
1621 	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1622 	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1623 	spin_lock(&user_list_lock);
1624 	as->next = user_list;
1625 	user_list = as;
1626 	spin_unlock(&user_list_lock);
1627 	filp->private_data = as;
1628 	return 0;
1629 }
1630 
1631 static int proc_apm_show(struct seq_file *m, void *v)
1632 {
1633 	unsigned short	bx;
1634 	unsigned short	cx;
1635 	unsigned short	dx;
1636 	int		error;
1637 	unsigned short  ac_line_status = 0xff;
1638 	unsigned short  battery_status = 0xff;
1639 	unsigned short  battery_flag   = 0xff;
1640 	int		percentage     = -1;
1641 	int             time_units     = -1;
1642 	char            *units         = "?";
1643 
1644 	if ((num_online_cpus() == 1) &&
1645 	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1646 		ac_line_status = (bx >> 8) & 0xff;
1647 		battery_status = bx & 0xff;
1648 		if ((cx & 0xff) != 0xff)
1649 			percentage = cx & 0xff;
1650 
1651 		if (apm_info.connection_version > 0x100) {
1652 			battery_flag = (cx >> 8) & 0xff;
1653 			if (dx != 0xffff) {
1654 				units = (dx & 0x8000) ? "min" : "sec";
1655 				time_units = dx & 0x7fff;
1656 			}
1657 		}
1658 	}
1659 	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1660 	   from the Get Power Status (0x0a) call unless otherwise noted.
1661 
1662 	   0) Linux driver version (this will change if format changes)
1663 	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1664 	   2) APM flags from APM Installation Check (0x00):
1665 	      bit 0: APM_16_BIT_SUPPORT
1666 	      bit 1: APM_32_BIT_SUPPORT
1667 	      bit 2: APM_IDLE_SLOWS_CLOCK
1668 	      bit 3: APM_BIOS_DISABLED
1669 	      bit 4: APM_BIOS_DISENGAGED
1670 	   3) AC line status
1671 	      0x00: Off-line
1672 	      0x01: On-line
1673 	      0x02: On backup power (BIOS >= 1.1 only)
1674 	      0xff: Unknown
1675 	   4) Battery status
1676 	      0x00: High
1677 	      0x01: Low
1678 	      0x02: Critical
1679 	      0x03: Charging
1680 	      0x04: Selected battery not present (BIOS >= 1.2 only)
1681 	      0xff: Unknown
1682 	   5) Battery flag
1683 	      bit 0: High
1684 	      bit 1: Low
1685 	      bit 2: Critical
1686 	      bit 3: Charging
1687 	      bit 7: No system battery
1688 	      0xff: Unknown
1689 	   6) Remaining battery life (percentage of charge):
1690 	      0-100: valid
1691 	      -1: Unknown
1692 	   7) Remaining battery life (time units):
1693 	      Number of remaining minutes or seconds
1694 	      -1: Unknown
1695 	   8) min = minutes; sec = seconds */
1696 
1697 	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1698 		   driver_version,
1699 		   (apm_info.bios.version >> 8) & 0xff,
1700 		   apm_info.bios.version & 0xff,
1701 		   apm_info.bios.flags,
1702 		   ac_line_status,
1703 		   battery_status,
1704 		   battery_flag,
1705 		   percentage,
1706 		   time_units,
1707 		   units);
1708 	return 0;
1709 }
1710 
1711 static int proc_apm_open(struct inode *inode, struct file *file)
1712 {
1713 	return single_open(file, proc_apm_show, NULL);
1714 }
1715 
1716 static const struct file_operations apm_file_ops = {
1717 	.owner		= THIS_MODULE,
1718 	.open		= proc_apm_open,
1719 	.read		= seq_read,
1720 	.llseek		= seq_lseek,
1721 	.release	= single_release,
1722 };
1723 
1724 static int apm(void *unused)
1725 {
1726 	unsigned short	bx;
1727 	unsigned short	cx;
1728 	unsigned short	dx;
1729 	int		error;
1730 	char 		*power_stat;
1731 	char 		*bat_stat;
1732 
1733 	/* 2002/08/01 - WT
1734 	 * This is to avoid random crashes at boot time during initialization
1735 	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1736 	 * Some bioses don't like being called from CPU != 0.
1737 	 * Method suggested by Ingo Molnar.
1738 	 */
1739 	set_cpus_allowed_ptr(current, cpumask_of(0));
1740 	BUG_ON(smp_processor_id() != 0);
1741 
1742 	if (apm_info.connection_version == 0) {
1743 		apm_info.connection_version = apm_info.bios.version;
1744 		if (apm_info.connection_version > 0x100) {
1745 			/*
1746 			 * We only support BIOSs up to version 1.2
1747 			 */
1748 			if (apm_info.connection_version > 0x0102)
1749 				apm_info.connection_version = 0x0102;
1750 			error = apm_driver_version(&apm_info.connection_version);
1751 			if (error != APM_SUCCESS) {
1752 				apm_error("driver version", error);
1753 				/* Fall back to an APM 1.0 connection. */
1754 				apm_info.connection_version = 0x100;
1755 			}
1756 		}
1757 	}
1758 
1759 	if (debug)
1760 		printk(KERN_INFO "apm: Connection version %d.%d\n",
1761 			(apm_info.connection_version >> 8) & 0xff,
1762 			apm_info.connection_version & 0xff);
1763 
1764 #ifdef CONFIG_APM_DO_ENABLE
1765 	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1766 		/*
1767 		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1768 		 * is booted with PM disabled but not in the docking station.
1769 		 * Unfortunate ...
1770 		 */
1771 		error = apm_enable_power_management(1);
1772 		if (error) {
1773 			apm_error("enable power management", error);
1774 			return -1;
1775 		}
1776 	}
1777 #endif
1778 
1779 	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1780 	    && (apm_info.connection_version > 0x0100)) {
1781 		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1782 		if (error) {
1783 			apm_error("engage power management", error);
1784 			return -1;
1785 		}
1786 	}
1787 
1788 	if (debug && (num_online_cpus() == 1 || smp)) {
1789 		error = apm_get_power_status(&bx, &cx, &dx);
1790 		if (error)
1791 			printk(KERN_INFO "apm: power status not available\n");
1792 		else {
1793 			switch ((bx >> 8) & 0xff) {
1794 			case 0:
1795 				power_stat = "off line";
1796 				break;
1797 			case 1:
1798 				power_stat = "on line";
1799 				break;
1800 			case 2:
1801 				power_stat = "on backup power";
1802 				break;
1803 			default:
1804 				power_stat = "unknown";
1805 				break;
1806 			}
1807 			switch (bx & 0xff) {
1808 			case 0:
1809 				bat_stat = "high";
1810 				break;
1811 			case 1:
1812 				bat_stat = "low";
1813 				break;
1814 			case 2:
1815 				bat_stat = "critical";
1816 				break;
1817 			case 3:
1818 				bat_stat = "charging";
1819 				break;
1820 			default:
1821 				bat_stat = "unknown";
1822 				break;
1823 			}
1824 			printk(KERN_INFO
1825 			       "apm: AC %s, battery status %s, battery life ",
1826 			       power_stat, bat_stat);
1827 			if ((cx & 0xff) == 0xff)
1828 				printk("unknown\n");
1829 			else
1830 				printk("%d%%\n", cx & 0xff);
1831 			if (apm_info.connection_version > 0x100) {
1832 				printk(KERN_INFO
1833 				       "apm: battery flag 0x%02x, battery life ",
1834 				       (cx >> 8) & 0xff);
1835 				if (dx == 0xffff)
1836 					printk("unknown\n");
1837 				else
1838 					printk("%d %s\n", dx & 0x7fff,
1839 					       (dx & 0x8000) ?
1840 					       "minutes" : "seconds");
1841 			}
1842 		}
1843 	}
1844 
1845 	/* Install our power off handler.. */
1846 	if (power_off)
1847 		pm_power_off = apm_power_off;
1848 
1849 	if (num_online_cpus() == 1 || smp) {
1850 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1851 		console_blank_hook = apm_console_blank;
1852 #endif
1853 		apm_mainloop();
1854 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1855 		console_blank_hook = NULL;
1856 #endif
1857 	}
1858 
1859 	return 0;
1860 }
1861 
1862 #ifndef MODULE
1863 static int __init apm_setup(char *str)
1864 {
1865 	int invert;
1866 
1867 	while ((str != NULL) && (*str != '\0')) {
1868 		if (strncmp(str, "off", 3) == 0)
1869 			apm_disabled = 1;
1870 		if (strncmp(str, "on", 2) == 0)
1871 			apm_disabled = 0;
1872 		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1873 		    (strncmp(str, "bounce_interval=", 16) == 0))
1874 			bounce_interval = simple_strtol(str + 16, NULL, 0);
1875 		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1876 		    (strncmp(str, "idle_threshold=", 15) == 0))
1877 			idle_threshold = simple_strtol(str + 15, NULL, 0);
1878 		if ((strncmp(str, "idle-period=", 12) == 0) ||
1879 		    (strncmp(str, "idle_period=", 12) == 0))
1880 			idle_period = simple_strtol(str + 12, NULL, 0);
1881 		invert = (strncmp(str, "no-", 3) == 0) ||
1882 			(strncmp(str, "no_", 3) == 0);
1883 		if (invert)
1884 			str += 3;
1885 		if (strncmp(str, "debug", 5) == 0)
1886 			debug = !invert;
1887 		if ((strncmp(str, "power-off", 9) == 0) ||
1888 		    (strncmp(str, "power_off", 9) == 0))
1889 			power_off = !invert;
1890 		if (strncmp(str, "smp", 3) == 0) {
1891 			smp = !invert;
1892 			idle_threshold = 100;
1893 		}
1894 		if ((strncmp(str, "allow-ints", 10) == 0) ||
1895 		    (strncmp(str, "allow_ints", 10) == 0))
1896 			apm_info.allow_ints = !invert;
1897 		if ((strncmp(str, "broken-psr", 10) == 0) ||
1898 		    (strncmp(str, "broken_psr", 10) == 0))
1899 			apm_info.get_power_status_broken = !invert;
1900 		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1901 		    (strncmp(str, "realmode_power_off", 18) == 0))
1902 			apm_info.realmode_power_off = !invert;
1903 		str = strchr(str, ',');
1904 		if (str != NULL)
1905 			str += strspn(str, ", \t");
1906 	}
1907 	return 1;
1908 }
1909 
1910 __setup("apm=", apm_setup);
1911 #endif
1912 
1913 static const struct file_operations apm_bios_fops = {
1914 	.owner		= THIS_MODULE,
1915 	.read		= do_read,
1916 	.poll		= do_poll,
1917 	.unlocked_ioctl	= do_ioctl,
1918 	.open		= do_open,
1919 	.release	= do_release,
1920 	.llseek		= noop_llseek,
1921 };
1922 
1923 static struct miscdevice apm_device = {
1924 	APM_MINOR_DEV,
1925 	"apm_bios",
1926 	&apm_bios_fops
1927 };
1928 
1929 
1930 /* Simple "print if true" callback */
1931 static int __init print_if_true(const struct dmi_system_id *d)
1932 {
1933 	printk("%s\n", d->ident);
1934 	return 0;
1935 }
1936 
1937 /*
1938  * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1939  * disabled before the suspend. Linux used to get terribly confused by that.
1940  */
1941 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1942 {
1943 	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1944 	       "workaround hopefully not needed.\n", d->ident);
1945 	return 0;
1946 }
1947 
1948 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1949 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1950 {
1951 	if (apm_info.realmode_power_off == 0) {
1952 		apm_info.realmode_power_off = 1;
1953 		printk(KERN_INFO "%s bios detected. "
1954 		       "Using realmode poweroff only.\n", d->ident);
1955 	}
1956 	return 0;
1957 }
1958 
1959 /* Some laptops require interrupts to be enabled during APM calls */
1960 static int __init set_apm_ints(const struct dmi_system_id *d)
1961 {
1962 	if (apm_info.allow_ints == 0) {
1963 		apm_info.allow_ints = 1;
1964 		printk(KERN_INFO "%s machine detected. "
1965 		       "Enabling interrupts during APM calls.\n", d->ident);
1966 	}
1967 	return 0;
1968 }
1969 
1970 /* Some APM bioses corrupt memory or just plain do not work */
1971 static int __init apm_is_horked(const struct dmi_system_id *d)
1972 {
1973 	if (apm_info.disabled == 0) {
1974 		apm_info.disabled = 1;
1975 		printk(KERN_INFO "%s machine detected. "
1976 		       "Disabling APM.\n", d->ident);
1977 	}
1978 	return 0;
1979 }
1980 
1981 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1982 {
1983 	if (apm_info.disabled == 0) {
1984 		apm_info.disabled = 1;
1985 		printk(KERN_INFO "%s machine detected. "
1986 		       "Disabling APM.\n", d->ident);
1987 		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1988 		printk(KERN_INFO "download from support.intel.com\n");
1989 	}
1990 	return 0;
1991 }
1992 
1993 /* Some APM bioses hang on APM idle calls */
1994 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1995 {
1996 	if (apm_info.forbid_idle == 0) {
1997 		apm_info.forbid_idle = 1;
1998 		printk(KERN_INFO "%s machine detected. "
1999 		       "Disabling APM idle calls.\n", d->ident);
2000 	}
2001 	return 0;
2002 }
2003 
2004 /*
2005  *  Check for clue free BIOS implementations who use
2006  *  the following QA technique
2007  *
2008  *      [ Write BIOS Code ]<------
2009  *               |                ^
2010  *      < Does it Compile >----N--
2011  *               |Y               ^
2012  *	< Does it Boot Win98 >-N--
2013  *               |Y
2014  *           [Ship It]
2015  *
2016  *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2017  *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2018  */
2019 static int __init broken_apm_power(const struct dmi_system_id *d)
2020 {
2021 	apm_info.get_power_status_broken = 1;
2022 	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2023 	       "disabling power status reporting.\n");
2024 	return 0;
2025 }
2026 
2027 /*
2028  * This bios swaps the APM minute reporting bytes over (Many sony laptops
2029  * have this problem).
2030  */
2031 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2032 {
2033 	apm_info.get_power_status_swabinminutes = 1;
2034 	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2035 	       "in minutes and wrong byte order.\n");
2036 	return 0;
2037 }
2038 
2039 static struct dmi_system_id __initdata apm_dmi_table[] = {
2040 	{
2041 		print_if_true,
2042 		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2043 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2044 			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2045 	},
2046 	{	/* Handle problems with APM on the C600 */
2047 		broken_ps2_resume, "Dell Latitude C600",
2048 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2049 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2050 	},
2051 	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2052 		set_apm_ints, "Dell Latitude",
2053 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2054 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2055 	},
2056 	{	/* APM crashes */
2057 		apm_is_horked, "Dell Inspiron 2500",
2058 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2059 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2060 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2061 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2062 	},
2063 	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2064 		set_apm_ints, "Dell Inspiron", {
2065 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2066 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2067 	},
2068 	{	/* Handle problems with APM on Inspiron 5000e */
2069 		broken_apm_power, "Dell Inspiron 5000e",
2070 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2071 			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2072 			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2073 	},
2074 	{	/* Handle problems with APM on Inspiron 2500 */
2075 		broken_apm_power, "Dell Inspiron 2500",
2076 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2077 			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2078 			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2079 	},
2080 	{	/* APM crashes */
2081 		apm_is_horked, "Dell Dimension 4100",
2082 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2083 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2084 			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2085 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2086 	},
2087 	{	/* Allow interrupts during suspend on Compaq Laptops*/
2088 		set_apm_ints, "Compaq 12XL125",
2089 		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2090 			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2091 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2092 			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2093 	},
2094 	{	/* Allow interrupts during APM or the clock goes slow */
2095 		set_apm_ints, "ASUSTeK",
2096 		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2097 			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2098 	},
2099 	{	/* APM blows on shutdown */
2100 		apm_is_horked, "ABIT KX7-333[R]",
2101 		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2102 			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2103 	},
2104 	{	/* APM crashes */
2105 		apm_is_horked, "Trigem Delhi3",
2106 		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2107 			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2108 	},
2109 	{	/* APM crashes */
2110 		apm_is_horked, "Fujitsu-Siemens",
2111 		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2112 			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2113 	},
2114 	{	/* APM crashes */
2115 		apm_is_horked_d850md, "Intel D850MD",
2116 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2117 			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2118 	},
2119 	{	/* APM crashes */
2120 		apm_is_horked, "Intel D810EMO",
2121 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2122 			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2123 	},
2124 	{	/* APM crashes */
2125 		apm_is_horked, "Dell XPS-Z",
2126 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2127 			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2128 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2129 	},
2130 	{	/* APM crashes */
2131 		apm_is_horked, "Sharp PC-PJ/AX",
2132 		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2133 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2134 			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2135 			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2136 	},
2137 	{	/* APM crashes */
2138 		apm_is_horked, "Dell Inspiron 2500",
2139 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2140 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2141 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2142 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2143 	},
2144 	{	/* APM idle hangs */
2145 		apm_likes_to_melt, "Jabil AMD",
2146 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2147 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2148 	},
2149 	{	/* APM idle hangs */
2150 		apm_likes_to_melt, "AMI Bios",
2151 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2152 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2153 	},
2154 	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2155 		swab_apm_power_in_minutes, "Sony VAIO",
2156 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2157 			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2158 			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2159 	},
2160 	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2161 		swab_apm_power_in_minutes, "Sony VAIO",
2162 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2163 			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2164 			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2165 	},
2166 	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2167 		swab_apm_power_in_minutes, "Sony VAIO",
2168 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2169 			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2170 			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2171 	},
2172 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2173 		swab_apm_power_in_minutes, "Sony VAIO",
2174 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2175 			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2176 			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2177 	},
2178 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2179 		swab_apm_power_in_minutes, "Sony VAIO",
2180 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2181 			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2182 			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2183 	},
2184 	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2185 		swab_apm_power_in_minutes, "Sony VAIO",
2186 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2187 			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2188 			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2189 	},
2190 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2191 		swab_apm_power_in_minutes, "Sony VAIO",
2192 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2193 			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2194 			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2195 	},
2196 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2197 		swab_apm_power_in_minutes, "Sony VAIO",
2198 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2199 			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2200 			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2201 	},
2202 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2203 		swab_apm_power_in_minutes, "Sony VAIO",
2204 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2205 			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2206 			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2207 	},
2208 	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2209 		swab_apm_power_in_minutes, "Sony VAIO",
2210 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2211 			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2212 			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2213 	},
2214 
2215 	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2216 		swab_apm_power_in_minutes, "Sony VAIO",
2217 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2218 			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2219 			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2220 	},
2221 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2222 		swab_apm_power_in_minutes, "Sony VAIO",
2223 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2224 			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2225 			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2226 	},
2227 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2228 		swab_apm_power_in_minutes, "Sony VAIO",
2229 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2230 			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2231 			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2232 	},
2233 	{	/* broken PM poweroff bios */
2234 		set_realmode_power_off, "Award Software v4.60 PGMA",
2235 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2236 			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2237 			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2238 	},
2239 
2240 	/* Generic per vendor APM settings  */
2241 
2242 	{	/* Allow interrupts during suspend on IBM laptops */
2243 		set_apm_ints, "IBM",
2244 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2245 	},
2246 
2247 	{ }
2248 };
2249 
2250 /*
2251  * Just start the APM thread. We do NOT want to do APM BIOS
2252  * calls from anything but the APM thread, if for no other reason
2253  * than the fact that we don't trust the APM BIOS. This way,
2254  * most common APM BIOS problems that lead to protection errors
2255  * etc will have at least some level of being contained...
2256  *
2257  * In short, if something bad happens, at least we have a choice
2258  * of just killing the apm thread..
2259  */
2260 static int __init apm_init(void)
2261 {
2262 	struct desc_struct *gdt;
2263 	int err;
2264 
2265 	dmi_check_system(apm_dmi_table);
2266 
2267 	if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2268 		printk(KERN_INFO "apm: BIOS not found.\n");
2269 		return -ENODEV;
2270 	}
2271 	printk(KERN_INFO
2272 	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2273 	       ((apm_info.bios.version >> 8) & 0xff),
2274 	       (apm_info.bios.version & 0xff),
2275 	       apm_info.bios.flags,
2276 	       driver_version);
2277 	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2278 		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2279 		return -ENODEV;
2280 	}
2281 
2282 	if (allow_ints)
2283 		apm_info.allow_ints = 1;
2284 	if (broken_psr)
2285 		apm_info.get_power_status_broken = 1;
2286 	if (realmode_power_off)
2287 		apm_info.realmode_power_off = 1;
2288 	/* User can override, but default is to trust DMI */
2289 	if (apm_disabled != -1)
2290 		apm_info.disabled = apm_disabled;
2291 
2292 	/*
2293 	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2294 	 * but is reportedly a 1.0 BIOS.
2295 	 */
2296 	if (apm_info.bios.version == 0x001)
2297 		apm_info.bios.version = 0x100;
2298 
2299 	/* BIOS < 1.2 doesn't set cseg_16_len */
2300 	if (apm_info.bios.version < 0x102)
2301 		apm_info.bios.cseg_16_len = 0; /* 64k */
2302 
2303 	if (debug) {
2304 		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2305 			apm_info.bios.cseg, apm_info.bios.offset,
2306 			apm_info.bios.cseg_16, apm_info.bios.dseg);
2307 		if (apm_info.bios.version > 0x100)
2308 			printk(" cseg len %x, dseg len %x",
2309 				apm_info.bios.cseg_len,
2310 				apm_info.bios.dseg_len);
2311 		if (apm_info.bios.version > 0x101)
2312 			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2313 		printk("\n");
2314 	}
2315 
2316 	if (apm_info.disabled) {
2317 		printk(KERN_NOTICE "apm: disabled on user request.\n");
2318 		return -ENODEV;
2319 	}
2320 	if ((num_online_cpus() > 1) && !power_off && !smp) {
2321 		printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2322 		apm_info.disabled = 1;
2323 		return -ENODEV;
2324 	}
2325 	if (!acpi_disabled) {
2326 		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2327 		apm_info.disabled = 1;
2328 		return -ENODEV;
2329 	}
2330 
2331 	/*
2332 	 * Set up the long jump entry point to the APM BIOS, which is called
2333 	 * from inline assembly.
2334 	 */
2335 	apm_bios_entry.offset = apm_info.bios.offset;
2336 	apm_bios_entry.segment = APM_CS;
2337 
2338 	/*
2339 	 * The APM 1.1 BIOS is supposed to provide limit information that it
2340 	 * recognizes.  Many machines do this correctly, but many others do
2341 	 * not restrict themselves to their claimed limit.  When this happens,
2342 	 * they will cause a segmentation violation in the kernel at boot time.
2343 	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2344 	 *
2345 	 * Note we only set APM segments on CPU zero, since we pin the APM
2346 	 * code to that CPU.
2347 	 */
2348 	gdt = get_cpu_gdt_table(0);
2349 	set_desc_base(&gdt[APM_CS >> 3],
2350 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2351 	set_desc_base(&gdt[APM_CS_16 >> 3],
2352 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2353 	set_desc_base(&gdt[APM_DS >> 3],
2354 		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2355 
2356 	proc_create("apm", 0, NULL, &apm_file_ops);
2357 
2358 	kapmd_task = kthread_create(apm, NULL, "kapmd");
2359 	if (IS_ERR(kapmd_task)) {
2360 		printk(KERN_ERR "apm: disabled - Unable to start kernel "
2361 				"thread.\n");
2362 		err = PTR_ERR(kapmd_task);
2363 		kapmd_task = NULL;
2364 		remove_proc_entry("apm", NULL);
2365 		return err;
2366 	}
2367 	wake_up_process(kapmd_task);
2368 
2369 	if (num_online_cpus() > 1 && !smp) {
2370 		printk(KERN_NOTICE
2371 		       "apm: disabled - APM is not SMP safe (power off active).\n");
2372 		return 0;
2373 	}
2374 
2375 	/*
2376 	 * Note we don't actually care if the misc_device cannot be registered.
2377 	 * this driver can do its job without it, even if userspace can't
2378 	 * control it.  just log the error
2379 	 */
2380 	if (misc_register(&apm_device))
2381 		printk(KERN_WARNING "apm: Could not register misc device.\n");
2382 
2383 	if (HZ != 100)
2384 		idle_period = (idle_period * HZ) / 100;
2385 	if (idle_threshold < 100) {
2386 		original_pm_idle = pm_idle;
2387 		pm_idle  = apm_cpu_idle;
2388 		set_pm_idle = 1;
2389 	}
2390 
2391 	return 0;
2392 }
2393 
2394 static void __exit apm_exit(void)
2395 {
2396 	int error;
2397 
2398 	if (set_pm_idle) {
2399 		pm_idle = original_pm_idle;
2400 		/*
2401 		 * We are about to unload the current idle thread pm callback
2402 		 * (pm_idle), Wait for all processors to update cached/local
2403 		 * copies of pm_idle before proceeding.
2404 		 */
2405 		cpu_idle_wait();
2406 	}
2407 	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2408 	    && (apm_info.connection_version > 0x0100)) {
2409 		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2410 		if (error)
2411 			apm_error("disengage power management", error);
2412 	}
2413 	misc_deregister(&apm_device);
2414 	remove_proc_entry("apm", NULL);
2415 	if (power_off)
2416 		pm_power_off = NULL;
2417 	if (kapmd_task) {
2418 		kthread_stop(kapmd_task);
2419 		kapmd_task = NULL;
2420 	}
2421 }
2422 
2423 module_init(apm_init);
2424 module_exit(apm_exit);
2425 
2426 MODULE_AUTHOR("Stephen Rothwell");
2427 MODULE_DESCRIPTION("Advanced Power Management");
2428 MODULE_LICENSE("GPL");
2429 module_param(debug, bool, 0644);
2430 MODULE_PARM_DESC(debug, "Enable debug mode");
2431 module_param(power_off, bool, 0444);
2432 MODULE_PARM_DESC(power_off, "Enable power off");
2433 module_param(bounce_interval, int, 0444);
2434 MODULE_PARM_DESC(bounce_interval,
2435 		"Set the number of ticks to ignore suspend bounces");
2436 module_param(allow_ints, bool, 0444);
2437 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2438 module_param(broken_psr, bool, 0444);
2439 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2440 module_param(realmode_power_off, bool, 0444);
2441 MODULE_PARM_DESC(realmode_power_off,
2442 		"Switch to real mode before powering off");
2443 module_param(idle_threshold, int, 0444);
2444 MODULE_PARM_DESC(idle_threshold,
2445 	"System idle percentage above which to make APM BIOS idle calls");
2446 module_param(idle_period, int, 0444);
2447 MODULE_PARM_DESC(idle_period,
2448 	"Period (in sec/100) over which to caculate the idle percentage");
2449 module_param(smp, bool, 0444);
2450 MODULE_PARM_DESC(smp,
2451 	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2452 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
2453