xref: /linux/arch/x86/kernel/apm_32.c (revision b233b28eac0cc37d07c2d007ea08c86c778c5af4)
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 complier/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@suse.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 via anonymous ftp from
193  * ftp://ftp.intel.com/pub/IAL/software_specs/apmv11.doc.  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/smp_lock.h>
208 #include <linux/types.h>
209 #include <linux/stddef.h>
210 #include <linux/timer.h>
211 #include <linux/fcntl.h>
212 #include <linux/slab.h>
213 #include <linux/stat.h>
214 #include <linux/proc_fs.h>
215 #include <linux/seq_file.h>
216 #include <linux/miscdevice.h>
217 #include <linux/apm_bios.h>
218 #include <linux/init.h>
219 #include <linux/time.h>
220 #include <linux/sched.h>
221 #include <linux/pm.h>
222 #include <linux/capability.h>
223 #include <linux/device.h>
224 #include <linux/kernel.h>
225 #include <linux/freezer.h>
226 #include <linux/smp.h>
227 #include <linux/dmi.h>
228 #include <linux/suspend.h>
229 #include <linux/kthread.h>
230 #include <linux/jiffies.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 "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 const struct desc_struct	bad_bios_desc = { { { 0, 0x00409200 } } };
407 
408 static const char driver_version[] = "1.16ac";	/* no spaces */
409 
410 static struct task_struct *kapmd_task;
411 
412 /*
413  *	APM event names taken from the APM 1.2 specification. These are
414  *	the message codes that the BIOS uses to tell us about events
415  */
416 static const char * const apm_event_name[] = {
417 	"system standby",
418 	"system suspend",
419 	"normal resume",
420 	"critical resume",
421 	"low battery",
422 	"power status change",
423 	"update time",
424 	"critical suspend",
425 	"user standby",
426 	"user suspend",
427 	"system standby resume",
428 	"capabilities change"
429 };
430 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
431 
432 typedef struct lookup_t {
433 	int	key;
434 	char 	*msg;
435 } lookup_t;
436 
437 /*
438  *	The BIOS returns a set of standard error codes in AX when the
439  *	carry flag is set.
440  */
441 
442 static const lookup_t error_table[] = {
443 /* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
444 	{ APM_DISABLED,		"Power management disabled" },
445 	{ APM_CONNECTED,	"Real mode interface already connected" },
446 	{ APM_NOT_CONNECTED,	"Interface not connected" },
447 	{ APM_16_CONNECTED,	"16 bit interface already connected" },
448 /* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
449 	{ APM_32_CONNECTED,	"32 bit interface already connected" },
450 	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
451 	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
452 	{ APM_BAD_PARAM,	"Parameter out of range" },
453 	{ APM_NOT_ENGAGED,	"Interface not engaged" },
454 	{ APM_BAD_FUNCTION,     "Function not supported" },
455 	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
456 	{ APM_BAD_STATE,	"Unable to enter requested state" },
457 /* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
458 	{ APM_NO_ERROR,		"BIOS did not set a return code" },
459 	{ APM_NOT_PRESENT,	"No APM present" }
460 };
461 #define ERROR_COUNT	ARRAY_SIZE(error_table)
462 
463 /**
464  *	apm_error	-	display an APM error
465  *	@str: information string
466  *	@err: APM BIOS return code
467  *
468  *	Write a meaningful log entry to the kernel log in the event of
469  *	an APM error.
470  */
471 
472 static void apm_error(char *str, int err)
473 {
474 	int i;
475 
476 	for (i = 0; i < ERROR_COUNT; i++)
477 		if (error_table[i].key == err)
478 			break;
479 	if (i < ERROR_COUNT)
480 		printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
481 	else
482 		printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
483 		       str, err);
484 }
485 
486 /*
487  * Lock APM functionality to physical CPU 0
488  */
489 
490 #ifdef CONFIG_SMP
491 
492 static cpumask_t apm_save_cpus(void)
493 {
494 	cpumask_t x = current->cpus_allowed;
495 	/* Some bioses don't like being called from CPU != 0 */
496 	set_cpus_allowed(current, cpumask_of_cpu(0));
497 	BUG_ON(smp_processor_id() != 0);
498 	return x;
499 }
500 
501 static inline void apm_restore_cpus(cpumask_t mask)
502 {
503 	set_cpus_allowed(current, mask);
504 }
505 
506 #else
507 
508 /*
509  *	No CPU lockdown needed on a uniprocessor
510  */
511 
512 #define apm_save_cpus()		(current->cpus_allowed)
513 #define apm_restore_cpus(x)	(void)(x)
514 
515 #endif
516 
517 /*
518  * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
519  * apm_info.allow_ints, we are being really paranoid here!  Not only
520  * are interrupts disabled, but all the segment registers (except SS)
521  * are saved and zeroed this means that if the BIOS tries to reference
522  * any data without explicitly loading the segment registers, the kernel
523  * will fault immediately rather than have some unforeseen circumstances
524  * for the rest of the kernel.  And it will be very obvious!  :-) Doing
525  * this depends on CS referring to the same physical memory as DS so that
526  * DS can be zeroed before the call. Unfortunately, we can't do anything
527  * about the stack segment/pointer.  Also, we tell the compiler that
528  * everything could change.
529  *
530  * Also, we KNOW that for the non error case of apm_bios_call, there
531  * is no useful data returned in the low order 8 bits of eax.
532  */
533 
534 static inline unsigned long __apm_irq_save(void)
535 {
536 	unsigned long flags;
537 	local_save_flags(flags);
538 	if (apm_info.allow_ints) {
539 		if (irqs_disabled_flags(flags))
540 			local_irq_enable();
541 	} else
542 		local_irq_disable();
543 
544 	return flags;
545 }
546 
547 #define apm_irq_save(flags) \
548 	do { flags = __apm_irq_save(); } while (0)
549 
550 static inline void apm_irq_restore(unsigned long flags)
551 {
552 	if (irqs_disabled_flags(flags))
553 		local_irq_disable();
554 	else if (irqs_disabled())
555 		local_irq_enable();
556 }
557 
558 #ifdef APM_ZERO_SEGS
559 #	define APM_DECL_SEGS \
560 		unsigned int saved_fs; unsigned int saved_gs;
561 #	define APM_DO_SAVE_SEGS \
562 		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
563 #	define APM_DO_RESTORE_SEGS \
564 		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
565 #else
566 #	define APM_DECL_SEGS
567 #	define APM_DO_SAVE_SEGS
568 #	define APM_DO_RESTORE_SEGS
569 #endif
570 
571 /**
572  *	apm_bios_call	-	Make an APM BIOS 32bit call
573  *	@func: APM function to execute
574  *	@ebx_in: EBX register for call entry
575  *	@ecx_in: ECX register for call entry
576  *	@eax: EAX register return
577  *	@ebx: EBX register return
578  *	@ecx: ECX register return
579  *	@edx: EDX register return
580  *	@esi: ESI register return
581  *
582  *	Make an APM call using the 32bit protected mode interface. The
583  *	caller is responsible for knowing if APM BIOS is configured and
584  *	enabled. This call can disable interrupts for a long period of
585  *	time on some laptops.  The return value is in AH and the carry
586  *	flag is loaded into AL.  If there is an error, then the error
587  *	code is returned in AH (bits 8-15 of eax) and this function
588  *	returns non-zero.
589  */
590 
591 static u8 apm_bios_call(u32 func, u32 ebx_in, u32 ecx_in,
592 	u32 *eax, u32 *ebx, u32 *ecx, u32 *edx, u32 *esi)
593 {
594 	APM_DECL_SEGS
595 	unsigned long		flags;
596 	cpumask_t		cpus;
597 	int			cpu;
598 	struct desc_struct	save_desc_40;
599 	struct desc_struct	*gdt;
600 
601 	cpus = apm_save_cpus();
602 
603 	cpu = get_cpu();
604 	gdt = get_cpu_gdt_table(cpu);
605 	save_desc_40 = gdt[0x40 / 8];
606 	gdt[0x40 / 8] = bad_bios_desc;
607 
608 	apm_irq_save(flags);
609 	APM_DO_SAVE_SEGS;
610 	apm_bios_call_asm(func, ebx_in, ecx_in, eax, ebx, ecx, edx, esi);
611 	APM_DO_RESTORE_SEGS;
612 	apm_irq_restore(flags);
613 	gdt[0x40 / 8] = save_desc_40;
614 	put_cpu();
615 	apm_restore_cpus(cpus);
616 
617 	return *eax & 0xff;
618 }
619 
620 /**
621  *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
622  *	@func: APM function to invoke
623  *	@ebx_in: EBX register value for BIOS call
624  *	@ecx_in: ECX register value for BIOS call
625  *	@eax: EAX register on return from the BIOS call
626  *
627  *	Make a BIOS call that returns one value only, or just status.
628  *	If there is an error, then the error code is returned in AH
629  *	(bits 8-15 of eax) and this function returns non-zero. This is
630  *	used for simpler BIOS operations. This call may hold interrupts
631  *	off for a long time on some laptops.
632  */
633 
634 static u8 apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax)
635 {
636 	u8			error;
637 	APM_DECL_SEGS
638 	unsigned long		flags;
639 	cpumask_t		cpus;
640 	int			cpu;
641 	struct desc_struct	save_desc_40;
642 	struct desc_struct	*gdt;
643 
644 	cpus = apm_save_cpus();
645 
646 	cpu = get_cpu();
647 	gdt = get_cpu_gdt_table(cpu);
648 	save_desc_40 = gdt[0x40 / 8];
649 	gdt[0x40 / 8] = bad_bios_desc;
650 
651 	apm_irq_save(flags);
652 	APM_DO_SAVE_SEGS;
653 	error = apm_bios_call_simple_asm(func, ebx_in, ecx_in, eax);
654 	APM_DO_RESTORE_SEGS;
655 	apm_irq_restore(flags);
656 	gdt[0x40 / 8] = save_desc_40;
657 	put_cpu();
658 	apm_restore_cpus(cpus);
659 	return error;
660 }
661 
662 /**
663  *	apm_driver_version	-	APM driver version
664  *	@val:	loaded with the APM version on return
665  *
666  *	Retrieve the APM version supported by the BIOS. This is only
667  *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
668  *	probably present.
669  *
670  *	On entry val should point to a value indicating the APM driver
671  *	version with the high byte being the major and the low byte the
672  *	minor number both in BCD
673  *
674  *	On return it will hold the BIOS revision supported in the
675  *	same format.
676  */
677 
678 static int apm_driver_version(u_short *val)
679 {
680 	u32 eax;
681 
682 	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax))
683 		return (eax >> 8) & 0xff;
684 	*val = eax;
685 	return APM_SUCCESS;
686 }
687 
688 /**
689  *	apm_get_event	-	get an APM event from the BIOS
690  *	@event: pointer to the event
691  *	@info: point to the event information
692  *
693  *	The APM BIOS provides a polled information for event
694  *	reporting. The BIOS expects to be polled at least every second
695  *	when events are pending. When a message is found the caller should
696  *	poll until no more messages are present.  However, this causes
697  *	problems on some laptops where a suspend event notification is
698  *	not cleared until it is acknowledged.
699  *
700  *	Additional information is returned in the info pointer, providing
701  *	that APM 1.2 is in use. If no messges are pending the value 0x80
702  *	is returned (No power management events pending).
703  */
704 
705 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
706 {
707 	u32 eax;
708 	u32 ebx;
709 	u32 ecx;
710 	u32 dummy;
711 
712 	if (apm_bios_call(APM_FUNC_GET_EVENT, 0, 0, &eax, &ebx, &ecx,
713 			  &dummy, &dummy))
714 		return (eax >> 8) & 0xff;
715 	*event = ebx;
716 	if (apm_info.connection_version < 0x0102)
717 		*info = ~0; /* indicate info not valid */
718 	else
719 		*info = ecx;
720 	return APM_SUCCESS;
721 }
722 
723 /**
724  *	set_power_state	-	set the power management state
725  *	@what: which items to transition
726  *	@state: state to transition to
727  *
728  *	Request an APM change of state for one or more system devices. The
729  *	processor state must be transitioned last of all. what holds the
730  *	class of device in the upper byte and the device number (0xFF for
731  *	all) for the object to be transitioned.
732  *
733  *	The state holds the state to transition to, which may in fact
734  *	be an acceptance of a BIOS requested state change.
735  */
736 
737 static int set_power_state(u_short what, u_short state)
738 {
739 	u32 eax;
740 
741 	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax))
742 		return (eax >> 8) & 0xff;
743 	return APM_SUCCESS;
744 }
745 
746 /**
747  *	set_system_power_state - set system wide power state
748  *	@state: which state to enter
749  *
750  *	Transition the entire system into a new APM power state.
751  */
752 
753 static int set_system_power_state(u_short state)
754 {
755 	return set_power_state(APM_DEVICE_ALL, state);
756 }
757 
758 /**
759  *	apm_do_idle	-	perform power saving
760  *
761  *	This function notifies the BIOS that the processor is (in the view
762  *	of the OS) idle. It returns -1 in the event that the BIOS refuses
763  *	to handle the idle request. On a success the function returns 1
764  *	if the BIOS did clock slowing or 0 otherwise.
765  */
766 
767 static int apm_do_idle(void)
768 {
769 	u32 eax;
770 	u8 ret = 0;
771 	int idled = 0;
772 	int polling;
773 
774 	polling = !!(current_thread_info()->status & TS_POLLING);
775 	if (polling) {
776 		current_thread_info()->status &= ~TS_POLLING;
777 		/*
778 		 * TS_POLLING-cleared state must be visible before we
779 		 * test NEED_RESCHED:
780 		 */
781 		smp_mb();
782 	}
783 	if (!need_resched()) {
784 		idled = 1;
785 		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax);
786 	}
787 	if (polling)
788 		current_thread_info()->status |= TS_POLLING;
789 
790 	if (!idled)
791 		return 0;
792 
793 	if (ret) {
794 		static unsigned long t;
795 
796 		/* This always fails on some SMP boards running UP kernels.
797 		 * Only report the failure the first 5 times.
798 		 */
799 		if (++t < 5) {
800 			printk(KERN_DEBUG "apm_do_idle failed (%d)\n",
801 			       (eax >> 8) & 0xff);
802 			t = jiffies;
803 		}
804 		return -1;
805 	}
806 	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
807 	return clock_slowed;
808 }
809 
810 /**
811  *	apm_do_busy	-	inform the BIOS the CPU is busy
812  *
813  *	Request that the BIOS brings the CPU back to full performance.
814  */
815 
816 static void apm_do_busy(void)
817 {
818 	u32 dummy;
819 
820 	if (clock_slowed || ALWAYS_CALL_BUSY) {
821 		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy);
822 		clock_slowed = 0;
823 	}
824 }
825 
826 /*
827  * If no process has really been interested in
828  * the CPU for some time, we want to call BIOS
829  * power management - we probably want
830  * to conserve power.
831  */
832 #define IDLE_CALC_LIMIT	(HZ * 100)
833 #define IDLE_LEAKY_MAX	16
834 
835 static void (*original_pm_idle)(void) __read_mostly;
836 
837 /**
838  * apm_cpu_idle		-	cpu idling for APM capable Linux
839  *
840  * This is the idling function the kernel executes when APM is available. It
841  * tries to do BIOS powermanagement based on the average system idle time.
842  * Furthermore it calls the system default idle routine.
843  */
844 
845 static void apm_cpu_idle(void)
846 {
847 	static int use_apm_idle; /* = 0 */
848 	static unsigned int last_jiffies; /* = 0 */
849 	static unsigned int last_stime; /* = 0 */
850 
851 	int apm_idle_done = 0;
852 	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
853 	unsigned int bucket;
854 
855 recalc:
856 	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
857 		use_apm_idle = 0;
858 		last_jiffies = jiffies;
859 		last_stime = current->stime;
860 	} else if (jiffies_since_last_check > idle_period) {
861 		unsigned int idle_percentage;
862 
863 		idle_percentage = current->stime - last_stime;
864 		idle_percentage *= 100;
865 		idle_percentage /= jiffies_since_last_check;
866 		use_apm_idle = (idle_percentage > idle_threshold);
867 		if (apm_info.forbid_idle)
868 			use_apm_idle = 0;
869 		last_jiffies = jiffies;
870 		last_stime = current->stime;
871 	}
872 
873 	bucket = IDLE_LEAKY_MAX;
874 
875 	while (!need_resched()) {
876 		if (use_apm_idle) {
877 			unsigned int t;
878 
879 			t = jiffies;
880 			switch (apm_do_idle()) {
881 			case 0:
882 				apm_idle_done = 1;
883 				if (t != jiffies) {
884 					if (bucket) {
885 						bucket = IDLE_LEAKY_MAX;
886 						continue;
887 					}
888 				} else if (bucket) {
889 					bucket--;
890 					continue;
891 				}
892 				break;
893 			case 1:
894 				apm_idle_done = 1;
895 				break;
896 			default: /* BIOS refused */
897 				break;
898 			}
899 		}
900 		if (original_pm_idle)
901 			original_pm_idle();
902 		else
903 			default_idle();
904 		local_irq_disable();
905 		jiffies_since_last_check = jiffies - last_jiffies;
906 		if (jiffies_since_last_check > idle_period)
907 			goto recalc;
908 	}
909 
910 	if (apm_idle_done)
911 		apm_do_busy();
912 
913 	local_irq_enable();
914 }
915 
916 /**
917  *	apm_power_off	-	ask the BIOS to power off
918  *
919  *	Handle the power off sequence. This is the one piece of code we
920  *	will execute even on SMP machines. In order to deal with BIOS
921  *	bugs we support real mode APM BIOS power off calls. We also make
922  *	the SMP call on CPU0 as some systems will only honour this call
923  *	on their first cpu.
924  */
925 
926 static void apm_power_off(void)
927 {
928 	unsigned char po_bios_call[] = {
929 		0xb8, 0x00, 0x10,	/* movw  $0x1000,ax  */
930 		0x8e, 0xd0,		/* movw  ax,ss       */
931 		0xbc, 0x00, 0xf0,	/* movw  $0xf000,sp  */
932 		0xb8, 0x07, 0x53,	/* movw  $0x5307,ax  */
933 		0xbb, 0x01, 0x00,	/* movw  $0x0001,bx  */
934 		0xb9, 0x03, 0x00,	/* movw  $0x0003,cx  */
935 		0xcd, 0x15		/* int   $0x15       */
936 	};
937 
938 	/* Some bioses don't like being called from CPU != 0 */
939 	if (apm_info.realmode_power_off) {
940 		(void)apm_save_cpus();
941 		machine_real_restart(po_bios_call, sizeof(po_bios_call));
942 	} else {
943 		(void)set_system_power_state(APM_STATE_OFF);
944 	}
945 }
946 
947 #ifdef CONFIG_APM_DO_ENABLE
948 
949 /**
950  *	apm_enable_power_management - enable BIOS APM power management
951  *	@enable: enable yes/no
952  *
953  *	Enable or disable the APM BIOS power services.
954  */
955 
956 static int apm_enable_power_management(int enable)
957 {
958 	u32 eax;
959 
960 	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
961 		return APM_NOT_ENGAGED;
962 	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
963 				 enable, &eax))
964 		return (eax >> 8) & 0xff;
965 	if (enable)
966 		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
967 	else
968 		apm_info.bios.flags |= APM_BIOS_DISABLED;
969 	return APM_SUCCESS;
970 }
971 #endif
972 
973 /**
974  *	apm_get_power_status	-	get current power state
975  *	@status: returned status
976  *	@bat: battery info
977  *	@life: estimated life
978  *
979  *	Obtain the current power status from the APM BIOS. We return a
980  *	status which gives the rough battery status, and current power
981  *	source. The bat value returned give an estimate as a percentage
982  *	of life and a status value for the battery. The estimated life
983  *	if reported is a lifetime in secodnds/minutes at current powwer
984  *	consumption.
985  */
986 
987 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
988 {
989 	u32 eax;
990 	u32 ebx;
991 	u32 ecx;
992 	u32 edx;
993 	u32 dummy;
994 
995 	if (apm_info.get_power_status_broken)
996 		return APM_32_UNSUPPORTED;
997 	if (apm_bios_call(APM_FUNC_GET_STATUS, APM_DEVICE_ALL, 0,
998 			  &eax, &ebx, &ecx, &edx, &dummy))
999 		return (eax >> 8) & 0xff;
1000 	*status = ebx;
1001 	*bat = ecx;
1002 	if (apm_info.get_power_status_swabinminutes) {
1003 		*life = swab16((u16)edx);
1004 		*life |= 0x8000;
1005 	} else
1006 		*life = edx;
1007 	return APM_SUCCESS;
1008 }
1009 
1010 #if 0
1011 static int apm_get_battery_status(u_short which, u_short *status,
1012 				  u_short *bat, u_short *life, u_short *nbat)
1013 {
1014 	u32 eax;
1015 	u32 ebx;
1016 	u32 ecx;
1017 	u32 edx;
1018 	u32 esi;
1019 
1020 	if (apm_info.connection_version < 0x0102) {
1021 		/* pretend we only have one battery. */
1022 		if (which != 1)
1023 			return APM_BAD_DEVICE;
1024 		*nbat = 1;
1025 		return apm_get_power_status(status, bat, life);
1026 	}
1027 
1028 	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1029 			  &ebx, &ecx, &edx, &esi))
1030 		return (eax >> 8) & 0xff;
1031 	*status = ebx;
1032 	*bat = ecx;
1033 	*life = edx;
1034 	*nbat = esi;
1035 	return APM_SUCCESS;
1036 }
1037 #endif
1038 
1039 /**
1040  *	apm_engage_power_management	-	enable PM on a device
1041  *	@device: identity of device
1042  *	@enable: on/off
1043  *
1044  *	Activate or deactive power management on either a specific device
1045  *	or the entire system (%APM_DEVICE_ALL).
1046  */
1047 
1048 static int apm_engage_power_management(u_short device, int enable)
1049 {
1050 	u32 eax;
1051 
1052 	if ((enable == 0) && (device == APM_DEVICE_ALL)
1053 	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1054 		return APM_DISABLED;
1055 	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable, &eax))
1056 		return (eax >> 8) & 0xff;
1057 	if (device == APM_DEVICE_ALL) {
1058 		if (enable)
1059 			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1060 		else
1061 			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1062 	}
1063 	return APM_SUCCESS;
1064 }
1065 
1066 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1067 
1068 /**
1069  *	apm_console_blank	-	blank the display
1070  *	@blank: on/off
1071  *
1072  *	Attempt to blank the console, firstly by blanking just video device
1073  *	zero, and if that fails (some BIOSes don't support it) then it blanks
1074  *	all video devices. Typically the BIOS will do laptop backlight and
1075  *	monitor powerdown for us.
1076  */
1077 
1078 static int apm_console_blank(int blank)
1079 {
1080 	int error = APM_NOT_ENGAGED; /* silence gcc */
1081 	int i;
1082 	u_short state;
1083 	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1084 
1085 	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1086 
1087 	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1088 		error = set_power_state(dev[i], state);
1089 
1090 		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1091 			return 1;
1092 
1093 		if (error == APM_NOT_ENGAGED)
1094 			break;
1095 	}
1096 
1097 	if (error == APM_NOT_ENGAGED) {
1098 		static int tried;
1099 		int eng_error;
1100 		if (tried++ == 0) {
1101 			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1102 			if (eng_error) {
1103 				apm_error("set display", error);
1104 				apm_error("engage interface", eng_error);
1105 				return 0;
1106 			} else
1107 				return apm_console_blank(blank);
1108 		}
1109 	}
1110 	apm_error("set display", error);
1111 	return 0;
1112 }
1113 #endif
1114 
1115 static int queue_empty(struct apm_user *as)
1116 {
1117 	return as->event_head == as->event_tail;
1118 }
1119 
1120 static apm_event_t get_queued_event(struct apm_user *as)
1121 {
1122 	if (++as->event_tail >= APM_MAX_EVENTS)
1123 		as->event_tail = 0;
1124 	return as->events[as->event_tail];
1125 }
1126 
1127 static void queue_event(apm_event_t event, struct apm_user *sender)
1128 {
1129 	struct apm_user *as;
1130 
1131 	spin_lock(&user_list_lock);
1132 	if (user_list == NULL)
1133 		goto out;
1134 	for (as = user_list; as != NULL; as = as->next) {
1135 		if ((as == sender) || (!as->reader))
1136 			continue;
1137 		if (++as->event_head >= APM_MAX_EVENTS)
1138 			as->event_head = 0;
1139 
1140 		if (as->event_head == as->event_tail) {
1141 			static int notified;
1142 
1143 			if (notified++ == 0)
1144 			    printk(KERN_ERR "apm: an event queue overflowed\n");
1145 			if (++as->event_tail >= APM_MAX_EVENTS)
1146 				as->event_tail = 0;
1147 		}
1148 		as->events[as->event_head] = event;
1149 		if (!as->suser || !as->writer)
1150 			continue;
1151 		switch (event) {
1152 		case APM_SYS_SUSPEND:
1153 		case APM_USER_SUSPEND:
1154 			as->suspends_pending++;
1155 			suspends_pending++;
1156 			break;
1157 
1158 		case APM_SYS_STANDBY:
1159 		case APM_USER_STANDBY:
1160 			as->standbys_pending++;
1161 			standbys_pending++;
1162 			break;
1163 		}
1164 	}
1165 	wake_up_interruptible(&apm_waitqueue);
1166 out:
1167 	spin_unlock(&user_list_lock);
1168 }
1169 
1170 static void reinit_timer(void)
1171 {
1172 #ifdef INIT_TIMER_AFTER_SUSPEND
1173 	unsigned long flags;
1174 
1175 	spin_lock_irqsave(&i8253_lock, flags);
1176 	/* set the clock to HZ */
1177 	outb_pit(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1178 	udelay(10);
1179 	outb_pit(LATCH & 0xff, PIT_CH0);	/* LSB */
1180 	udelay(10);
1181 	outb_pit(LATCH >> 8, PIT_CH0);	/* MSB */
1182 	udelay(10);
1183 	spin_unlock_irqrestore(&i8253_lock, flags);
1184 #endif
1185 }
1186 
1187 static int suspend(int vetoable)
1188 {
1189 	int err;
1190 	struct apm_user	*as;
1191 
1192 	device_suspend(PMSG_SUSPEND);
1193 	local_irq_disable();
1194 	device_power_down(PMSG_SUSPEND);
1195 
1196 	local_irq_enable();
1197 
1198 	save_processor_state();
1199 	err = set_system_power_state(APM_STATE_SUSPEND);
1200 	ignore_normal_resume = 1;
1201 	restore_processor_state();
1202 
1203 	local_irq_disable();
1204 	reinit_timer();
1205 
1206 	if (err == APM_NO_ERROR)
1207 		err = APM_SUCCESS;
1208 	if (err != APM_SUCCESS)
1209 		apm_error("suspend", err);
1210 	err = (err == APM_SUCCESS) ? 0 : -EIO;
1211 	device_power_up(PMSG_RESUME);
1212 	local_irq_enable();
1213 	device_resume(PMSG_RESUME);
1214 	queue_event(APM_NORMAL_RESUME, NULL);
1215 	spin_lock(&user_list_lock);
1216 	for (as = user_list; as != NULL; as = as->next) {
1217 		as->suspend_wait = 0;
1218 		as->suspend_result = err;
1219 	}
1220 	spin_unlock(&user_list_lock);
1221 	wake_up_interruptible(&apm_suspend_waitqueue);
1222 	return err;
1223 }
1224 
1225 static void standby(void)
1226 {
1227 	int err;
1228 
1229 	local_irq_disable();
1230 	device_power_down(PMSG_SUSPEND);
1231 	local_irq_enable();
1232 
1233 	err = set_system_power_state(APM_STATE_STANDBY);
1234 	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1235 		apm_error("standby", err);
1236 
1237 	local_irq_disable();
1238 	device_power_up(PMSG_RESUME);
1239 	local_irq_enable();
1240 }
1241 
1242 static apm_event_t get_event(void)
1243 {
1244 	int error;
1245 	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1246 	apm_eventinfo_t	info;
1247 
1248 	static int notified;
1249 
1250 	/* we don't use the eventinfo */
1251 	error = apm_get_event(&event, &info);
1252 	if (error == APM_SUCCESS)
1253 		return event;
1254 
1255 	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1256 		apm_error("get_event", error);
1257 
1258 	return 0;
1259 }
1260 
1261 static void check_events(void)
1262 {
1263 	apm_event_t event;
1264 	static unsigned long last_resume;
1265 	static int ignore_bounce;
1266 
1267 	while ((event = get_event()) != 0) {
1268 		if (debug) {
1269 			if (event <= NR_APM_EVENT_NAME)
1270 				printk(KERN_DEBUG "apm: received %s notify\n",
1271 				       apm_event_name[event - 1]);
1272 			else
1273 				printk(KERN_DEBUG "apm: received unknown "
1274 				       "event 0x%02x\n", event);
1275 		}
1276 		if (ignore_bounce
1277 		    && (time_after(jiffies, last_resume + bounce_interval)))
1278 			ignore_bounce = 0;
1279 
1280 		switch (event) {
1281 		case APM_SYS_STANDBY:
1282 		case APM_USER_STANDBY:
1283 			queue_event(event, NULL);
1284 			if (standbys_pending <= 0)
1285 				standby();
1286 			break;
1287 
1288 		case APM_USER_SUSPEND:
1289 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1290 			if (apm_info.connection_version > 0x100)
1291 				set_system_power_state(APM_STATE_REJECT);
1292 			break;
1293 #endif
1294 		case APM_SYS_SUSPEND:
1295 			if (ignore_bounce) {
1296 				if (apm_info.connection_version > 0x100)
1297 					set_system_power_state(APM_STATE_REJECT);
1298 				break;
1299 			}
1300 			/*
1301 			 * If we are already processing a SUSPEND,
1302 			 * then further SUSPEND events from the BIOS
1303 			 * will be ignored.  We also return here to
1304 			 * cope with the fact that the Thinkpads keep
1305 			 * sending a SUSPEND event until something else
1306 			 * happens!
1307 			 */
1308 			if (ignore_sys_suspend)
1309 				return;
1310 			ignore_sys_suspend = 1;
1311 			queue_event(event, NULL);
1312 			if (suspends_pending <= 0)
1313 				(void) suspend(1);
1314 			break;
1315 
1316 		case APM_NORMAL_RESUME:
1317 		case APM_CRITICAL_RESUME:
1318 		case APM_STANDBY_RESUME:
1319 			ignore_sys_suspend = 0;
1320 			last_resume = jiffies;
1321 			ignore_bounce = 1;
1322 			if ((event != APM_NORMAL_RESUME)
1323 			    || (ignore_normal_resume == 0)) {
1324 				device_resume(PMSG_RESUME);
1325 				queue_event(event, NULL);
1326 			}
1327 			ignore_normal_resume = 0;
1328 			break;
1329 
1330 		case APM_CAPABILITY_CHANGE:
1331 		case APM_LOW_BATTERY:
1332 		case APM_POWER_STATUS_CHANGE:
1333 			queue_event(event, NULL);
1334 			/* If needed, notify drivers here */
1335 			break;
1336 
1337 		case APM_UPDATE_TIME:
1338 			break;
1339 
1340 		case APM_CRITICAL_SUSPEND:
1341 			/*
1342 			 * We are not allowed to reject a critical suspend.
1343 			 */
1344 			(void)suspend(0);
1345 			break;
1346 		}
1347 	}
1348 }
1349 
1350 static void apm_event_handler(void)
1351 {
1352 	static int pending_count = 4;
1353 	int err;
1354 
1355 	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1356 		if ((apm_info.connection_version > 0x100) &&
1357 		    (pending_count-- <= 0)) {
1358 			pending_count = 4;
1359 			if (debug)
1360 				printk(KERN_DEBUG "apm: setting state busy\n");
1361 			err = set_system_power_state(APM_STATE_BUSY);
1362 			if (err)
1363 				apm_error("busy", err);
1364 		}
1365 	} else
1366 		pending_count = 4;
1367 	check_events();
1368 }
1369 
1370 /*
1371  * This is the APM thread main loop.
1372  */
1373 
1374 static void apm_mainloop(void)
1375 {
1376 	DECLARE_WAITQUEUE(wait, current);
1377 
1378 	add_wait_queue(&apm_waitqueue, &wait);
1379 	set_current_state(TASK_INTERRUPTIBLE);
1380 	for (;;) {
1381 		schedule_timeout(APM_CHECK_TIMEOUT);
1382 		if (kthread_should_stop())
1383 			break;
1384 		/*
1385 		 * Ok, check all events, check for idle (and mark us sleeping
1386 		 * so as not to count towards the load average)..
1387 		 */
1388 		set_current_state(TASK_INTERRUPTIBLE);
1389 		apm_event_handler();
1390 	}
1391 	remove_wait_queue(&apm_waitqueue, &wait);
1392 }
1393 
1394 static int check_apm_user(struct apm_user *as, const char *func)
1395 {
1396 	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1397 		printk(KERN_ERR "apm: %s passed bad filp\n", func);
1398 		return 1;
1399 	}
1400 	return 0;
1401 }
1402 
1403 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1404 {
1405 	struct apm_user *as;
1406 	int i;
1407 	apm_event_t event;
1408 
1409 	as = fp->private_data;
1410 	if (check_apm_user(as, "read"))
1411 		return -EIO;
1412 	if ((int)count < sizeof(apm_event_t))
1413 		return -EINVAL;
1414 	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1415 		return -EAGAIN;
1416 	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1417 	i = count;
1418 	while ((i >= sizeof(event)) && !queue_empty(as)) {
1419 		event = get_queued_event(as);
1420 		if (copy_to_user(buf, &event, sizeof(event))) {
1421 			if (i < count)
1422 				break;
1423 			return -EFAULT;
1424 		}
1425 		switch (event) {
1426 		case APM_SYS_SUSPEND:
1427 		case APM_USER_SUSPEND:
1428 			as->suspends_read++;
1429 			break;
1430 
1431 		case APM_SYS_STANDBY:
1432 		case APM_USER_STANDBY:
1433 			as->standbys_read++;
1434 			break;
1435 		}
1436 		buf += sizeof(event);
1437 		i -= sizeof(event);
1438 	}
1439 	if (i < count)
1440 		return count - i;
1441 	if (signal_pending(current))
1442 		return -ERESTARTSYS;
1443 	return 0;
1444 }
1445 
1446 static unsigned int do_poll(struct file *fp, poll_table *wait)
1447 {
1448 	struct apm_user *as;
1449 
1450 	as = fp->private_data;
1451 	if (check_apm_user(as, "poll"))
1452 		return 0;
1453 	poll_wait(fp, &apm_waitqueue, wait);
1454 	if (!queue_empty(as))
1455 		return POLLIN | POLLRDNORM;
1456 	return 0;
1457 }
1458 
1459 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1460 {
1461 	struct apm_user *as;
1462 	int ret;
1463 
1464 	as = filp->private_data;
1465 	if (check_apm_user(as, "ioctl"))
1466 		return -EIO;
1467 	if (!as->suser || !as->writer)
1468 		return -EPERM;
1469 	switch (cmd) {
1470 	case APM_IOC_STANDBY:
1471 		lock_kernel();
1472 		if (as->standbys_read > 0) {
1473 			as->standbys_read--;
1474 			as->standbys_pending--;
1475 			standbys_pending--;
1476 		} else
1477 			queue_event(APM_USER_STANDBY, as);
1478 		if (standbys_pending <= 0)
1479 			standby();
1480 		unlock_kernel();
1481 		break;
1482 	case APM_IOC_SUSPEND:
1483 		lock_kernel();
1484 		if (as->suspends_read > 0) {
1485 			as->suspends_read--;
1486 			as->suspends_pending--;
1487 			suspends_pending--;
1488 		} else
1489 			queue_event(APM_USER_SUSPEND, as);
1490 		if (suspends_pending <= 0) {
1491 			ret = suspend(1);
1492 		} else {
1493 			as->suspend_wait = 1;
1494 			wait_event_interruptible(apm_suspend_waitqueue,
1495 					as->suspend_wait == 0);
1496 			ret = as->suspend_result;
1497 		}
1498 		unlock_kernel();
1499 		return ret;
1500 	default:
1501 		return -ENOTTY;
1502 	}
1503 	return 0;
1504 }
1505 
1506 static int do_release(struct inode *inode, struct file *filp)
1507 {
1508 	struct apm_user *as;
1509 
1510 	as = filp->private_data;
1511 	if (check_apm_user(as, "release"))
1512 		return 0;
1513 	filp->private_data = NULL;
1514 	if (as->standbys_pending > 0) {
1515 		standbys_pending -= as->standbys_pending;
1516 		if (standbys_pending <= 0)
1517 			standby();
1518 	}
1519 	if (as->suspends_pending > 0) {
1520 		suspends_pending -= as->suspends_pending;
1521 		if (suspends_pending <= 0)
1522 			(void) suspend(1);
1523 	}
1524 	spin_lock(&user_list_lock);
1525 	if (user_list == as)
1526 		user_list = as->next;
1527 	else {
1528 		struct apm_user *as1;
1529 
1530 		for (as1 = user_list;
1531 		     (as1 != NULL) && (as1->next != as);
1532 		     as1 = as1->next)
1533 			;
1534 		if (as1 == NULL)
1535 			printk(KERN_ERR "apm: filp not in user list\n");
1536 		else
1537 			as1->next = as->next;
1538 	}
1539 	spin_unlock(&user_list_lock);
1540 	kfree(as);
1541 	return 0;
1542 }
1543 
1544 static int do_open(struct inode *inode, struct file *filp)
1545 {
1546 	struct apm_user *as;
1547 
1548 	lock_kernel();
1549 	as = kmalloc(sizeof(*as), GFP_KERNEL);
1550 	if (as == NULL) {
1551 		printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1552 		       sizeof(*as));
1553 		       unlock_kernel();
1554 		return -ENOMEM;
1555 	}
1556 	as->magic = APM_BIOS_MAGIC;
1557 	as->event_tail = as->event_head = 0;
1558 	as->suspends_pending = as->standbys_pending = 0;
1559 	as->suspends_read = as->standbys_read = 0;
1560 	/*
1561 	 * XXX - this is a tiny bit broken, when we consider BSD
1562 	 * process accounting. If the device is opened by root, we
1563 	 * instantly flag that we used superuser privs. Who knows,
1564 	 * we might close the device immediately without doing a
1565 	 * privileged operation -- cevans
1566 	 */
1567 	as->suser = capable(CAP_SYS_ADMIN);
1568 	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1569 	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1570 	spin_lock(&user_list_lock);
1571 	as->next = user_list;
1572 	user_list = as;
1573 	spin_unlock(&user_list_lock);
1574 	filp->private_data = as;
1575 	unlock_kernel();
1576 	return 0;
1577 }
1578 
1579 static int proc_apm_show(struct seq_file *m, void *v)
1580 {
1581 	unsigned short	bx;
1582 	unsigned short	cx;
1583 	unsigned short	dx;
1584 	int		error;
1585 	unsigned short  ac_line_status = 0xff;
1586 	unsigned short  battery_status = 0xff;
1587 	unsigned short  battery_flag   = 0xff;
1588 	int		percentage     = -1;
1589 	int             time_units     = -1;
1590 	char            *units         = "?";
1591 
1592 	if ((num_online_cpus() == 1) &&
1593 	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1594 		ac_line_status = (bx >> 8) & 0xff;
1595 		battery_status = bx & 0xff;
1596 		if ((cx & 0xff) != 0xff)
1597 			percentage = cx & 0xff;
1598 
1599 		if (apm_info.connection_version > 0x100) {
1600 			battery_flag = (cx >> 8) & 0xff;
1601 			if (dx != 0xffff) {
1602 				units = (dx & 0x8000) ? "min" : "sec";
1603 				time_units = dx & 0x7fff;
1604 			}
1605 		}
1606 	}
1607 	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1608 	   from the Get Power Status (0x0a) call unless otherwise noted.
1609 
1610 	   0) Linux driver version (this will change if format changes)
1611 	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1612 	   2) APM flags from APM Installation Check (0x00):
1613 	      bit 0: APM_16_BIT_SUPPORT
1614 	      bit 1: APM_32_BIT_SUPPORT
1615 	      bit 2: APM_IDLE_SLOWS_CLOCK
1616 	      bit 3: APM_BIOS_DISABLED
1617 	      bit 4: APM_BIOS_DISENGAGED
1618 	   3) AC line status
1619 	      0x00: Off-line
1620 	      0x01: On-line
1621 	      0x02: On backup power (BIOS >= 1.1 only)
1622 	      0xff: Unknown
1623 	   4) Battery status
1624 	      0x00: High
1625 	      0x01: Low
1626 	      0x02: Critical
1627 	      0x03: Charging
1628 	      0x04: Selected battery not present (BIOS >= 1.2 only)
1629 	      0xff: Unknown
1630 	   5) Battery flag
1631 	      bit 0: High
1632 	      bit 1: Low
1633 	      bit 2: Critical
1634 	      bit 3: Charging
1635 	      bit 7: No system battery
1636 	      0xff: Unknown
1637 	   6) Remaining battery life (percentage of charge):
1638 	      0-100: valid
1639 	      -1: Unknown
1640 	   7) Remaining battery life (time units):
1641 	      Number of remaining minutes or seconds
1642 	      -1: Unknown
1643 	   8) min = minutes; sec = seconds */
1644 
1645 	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1646 		   driver_version,
1647 		   (apm_info.bios.version >> 8) & 0xff,
1648 		   apm_info.bios.version & 0xff,
1649 		   apm_info.bios.flags,
1650 		   ac_line_status,
1651 		   battery_status,
1652 		   battery_flag,
1653 		   percentage,
1654 		   time_units,
1655 		   units);
1656 	return 0;
1657 }
1658 
1659 static int proc_apm_open(struct inode *inode, struct file *file)
1660 {
1661 	return single_open(file, proc_apm_show, NULL);
1662 }
1663 
1664 static const struct file_operations apm_file_ops = {
1665 	.owner		= THIS_MODULE,
1666 	.open		= proc_apm_open,
1667 	.read		= seq_read,
1668 	.llseek		= seq_lseek,
1669 	.release	= single_release,
1670 };
1671 
1672 static int apm(void *unused)
1673 {
1674 	unsigned short	bx;
1675 	unsigned short	cx;
1676 	unsigned short	dx;
1677 	int		error;
1678 	char 		*power_stat;
1679 	char 		*bat_stat;
1680 
1681 #ifdef CONFIG_SMP
1682 	/* 2002/08/01 - WT
1683 	 * This is to avoid random crashes at boot time during initialization
1684 	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1685 	 * Some bioses don't like being called from CPU != 0.
1686 	 * Method suggested by Ingo Molnar.
1687 	 */
1688 	set_cpus_allowed(current, cpumask_of_cpu(0));
1689 	BUG_ON(smp_processor_id() != 0);
1690 #endif
1691 
1692 	if (apm_info.connection_version == 0) {
1693 		apm_info.connection_version = apm_info.bios.version;
1694 		if (apm_info.connection_version > 0x100) {
1695 			/*
1696 			 * We only support BIOSs up to version 1.2
1697 			 */
1698 			if (apm_info.connection_version > 0x0102)
1699 				apm_info.connection_version = 0x0102;
1700 			error = apm_driver_version(&apm_info.connection_version);
1701 			if (error != APM_SUCCESS) {
1702 				apm_error("driver version", error);
1703 				/* Fall back to an APM 1.0 connection. */
1704 				apm_info.connection_version = 0x100;
1705 			}
1706 		}
1707 	}
1708 
1709 	if (debug)
1710 		printk(KERN_INFO "apm: Connection version %d.%d\n",
1711 			(apm_info.connection_version >> 8) & 0xff,
1712 			apm_info.connection_version & 0xff);
1713 
1714 #ifdef CONFIG_APM_DO_ENABLE
1715 	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1716 		/*
1717 		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1718 		 * is booted with PM disabled but not in the docking station.
1719 		 * Unfortunate ...
1720 		 */
1721 		error = apm_enable_power_management(1);
1722 		if (error) {
1723 			apm_error("enable power management", error);
1724 			return -1;
1725 		}
1726 	}
1727 #endif
1728 
1729 	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1730 	    && (apm_info.connection_version > 0x0100)) {
1731 		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1732 		if (error) {
1733 			apm_error("engage power management", error);
1734 			return -1;
1735 		}
1736 	}
1737 
1738 	if (debug && (num_online_cpus() == 1 || smp)) {
1739 		error = apm_get_power_status(&bx, &cx, &dx);
1740 		if (error)
1741 			printk(KERN_INFO "apm: power status not available\n");
1742 		else {
1743 			switch ((bx >> 8) & 0xff) {
1744 			case 0:
1745 				power_stat = "off line";
1746 				break;
1747 			case 1:
1748 				power_stat = "on line";
1749 				break;
1750 			case 2:
1751 				power_stat = "on backup power";
1752 				break;
1753 			default:
1754 				power_stat = "unknown";
1755 				break;
1756 			}
1757 			switch (bx & 0xff) {
1758 			case 0:
1759 				bat_stat = "high";
1760 				break;
1761 			case 1:
1762 				bat_stat = "low";
1763 				break;
1764 			case 2:
1765 				bat_stat = "critical";
1766 				break;
1767 			case 3:
1768 				bat_stat = "charging";
1769 				break;
1770 			default:
1771 				bat_stat = "unknown";
1772 				break;
1773 			}
1774 			printk(KERN_INFO
1775 			       "apm: AC %s, battery status %s, battery life ",
1776 			       power_stat, bat_stat);
1777 			if ((cx & 0xff) == 0xff)
1778 				printk("unknown\n");
1779 			else
1780 				printk("%d%%\n", cx & 0xff);
1781 			if (apm_info.connection_version > 0x100) {
1782 				printk(KERN_INFO
1783 				       "apm: battery flag 0x%02x, battery life ",
1784 				       (cx >> 8) & 0xff);
1785 				if (dx == 0xffff)
1786 					printk("unknown\n");
1787 				else
1788 					printk("%d %s\n", dx & 0x7fff,
1789 					       (dx & 0x8000) ?
1790 					       "minutes" : "seconds");
1791 			}
1792 		}
1793 	}
1794 
1795 	/* Install our power off handler.. */
1796 	if (power_off)
1797 		pm_power_off = apm_power_off;
1798 
1799 	if (num_online_cpus() == 1 || smp) {
1800 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1801 		console_blank_hook = apm_console_blank;
1802 #endif
1803 		apm_mainloop();
1804 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1805 		console_blank_hook = NULL;
1806 #endif
1807 	}
1808 
1809 	return 0;
1810 }
1811 
1812 #ifndef MODULE
1813 static int __init apm_setup(char *str)
1814 {
1815 	int invert;
1816 
1817 	while ((str != NULL) && (*str != '\0')) {
1818 		if (strncmp(str, "off", 3) == 0)
1819 			apm_disabled = 1;
1820 		if (strncmp(str, "on", 2) == 0)
1821 			apm_disabled = 0;
1822 		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1823 		    (strncmp(str, "bounce_interval=", 16) == 0))
1824 			bounce_interval = simple_strtol(str + 16, NULL, 0);
1825 		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1826 		    (strncmp(str, "idle_threshold=", 15) == 0))
1827 			idle_threshold = simple_strtol(str + 15, NULL, 0);
1828 		if ((strncmp(str, "idle-period=", 12) == 0) ||
1829 		    (strncmp(str, "idle_period=", 12) == 0))
1830 			idle_period = simple_strtol(str + 12, NULL, 0);
1831 		invert = (strncmp(str, "no-", 3) == 0) ||
1832 			(strncmp(str, "no_", 3) == 0);
1833 		if (invert)
1834 			str += 3;
1835 		if (strncmp(str, "debug", 5) == 0)
1836 			debug = !invert;
1837 		if ((strncmp(str, "power-off", 9) == 0) ||
1838 		    (strncmp(str, "power_off", 9) == 0))
1839 			power_off = !invert;
1840 		if (strncmp(str, "smp", 3) == 0) {
1841 			smp = !invert;
1842 			idle_threshold = 100;
1843 		}
1844 		if ((strncmp(str, "allow-ints", 10) == 0) ||
1845 		    (strncmp(str, "allow_ints", 10) == 0))
1846 			apm_info.allow_ints = !invert;
1847 		if ((strncmp(str, "broken-psr", 10) == 0) ||
1848 		    (strncmp(str, "broken_psr", 10) == 0))
1849 			apm_info.get_power_status_broken = !invert;
1850 		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1851 		    (strncmp(str, "realmode_power_off", 18) == 0))
1852 			apm_info.realmode_power_off = !invert;
1853 		str = strchr(str, ',');
1854 		if (str != NULL)
1855 			str += strspn(str, ", \t");
1856 	}
1857 	return 1;
1858 }
1859 
1860 __setup("apm=", apm_setup);
1861 #endif
1862 
1863 static const struct file_operations apm_bios_fops = {
1864 	.owner		= THIS_MODULE,
1865 	.read		= do_read,
1866 	.poll		= do_poll,
1867 	.unlocked_ioctl	= do_ioctl,
1868 	.open		= do_open,
1869 	.release	= do_release,
1870 };
1871 
1872 static struct miscdevice apm_device = {
1873 	APM_MINOR_DEV,
1874 	"apm_bios",
1875 	&apm_bios_fops
1876 };
1877 
1878 
1879 /* Simple "print if true" callback */
1880 static int __init print_if_true(const struct dmi_system_id *d)
1881 {
1882 	printk("%s\n", d->ident);
1883 	return 0;
1884 }
1885 
1886 /*
1887  * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1888  * disabled before the suspend. Linux used to get terribly confused by that.
1889  */
1890 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1891 {
1892 	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1893 	       "workaround hopefully not needed.\n", d->ident);
1894 	return 0;
1895 }
1896 
1897 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1898 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1899 {
1900 	if (apm_info.realmode_power_off == 0) {
1901 		apm_info.realmode_power_off = 1;
1902 		printk(KERN_INFO "%s bios detected. "
1903 		       "Using realmode poweroff only.\n", d->ident);
1904 	}
1905 	return 0;
1906 }
1907 
1908 /* Some laptops require interrupts to be enabled during APM calls */
1909 static int __init set_apm_ints(const struct dmi_system_id *d)
1910 {
1911 	if (apm_info.allow_ints == 0) {
1912 		apm_info.allow_ints = 1;
1913 		printk(KERN_INFO "%s machine detected. "
1914 		       "Enabling interrupts during APM calls.\n", d->ident);
1915 	}
1916 	return 0;
1917 }
1918 
1919 /* Some APM bioses corrupt memory or just plain do not work */
1920 static int __init apm_is_horked(const struct dmi_system_id *d)
1921 {
1922 	if (apm_info.disabled == 0) {
1923 		apm_info.disabled = 1;
1924 		printk(KERN_INFO "%s machine detected. "
1925 		       "Disabling APM.\n", d->ident);
1926 	}
1927 	return 0;
1928 }
1929 
1930 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1931 {
1932 	if (apm_info.disabled == 0) {
1933 		apm_info.disabled = 1;
1934 		printk(KERN_INFO "%s machine detected. "
1935 		       "Disabling APM.\n", d->ident);
1936 		printk(KERN_INFO "This bug is fixed in bios P15 which is available for \n");
1937 		printk(KERN_INFO "download from support.intel.com \n");
1938 	}
1939 	return 0;
1940 }
1941 
1942 /* Some APM bioses hang on APM idle calls */
1943 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1944 {
1945 	if (apm_info.forbid_idle == 0) {
1946 		apm_info.forbid_idle = 1;
1947 		printk(KERN_INFO "%s machine detected. "
1948 		       "Disabling APM idle calls.\n", d->ident);
1949 	}
1950 	return 0;
1951 }
1952 
1953 /*
1954  *  Check for clue free BIOS implementations who use
1955  *  the following QA technique
1956  *
1957  *      [ Write BIOS Code ]<------
1958  *               |                ^
1959  *      < Does it Compile >----N--
1960  *               |Y               ^
1961  *	< Does it Boot Win98 >-N--
1962  *               |Y
1963  *           [Ship It]
1964  *
1965  *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
1966  *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
1967  */
1968 static int __init broken_apm_power(const struct dmi_system_id *d)
1969 {
1970 	apm_info.get_power_status_broken = 1;
1971 	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
1972 	       "disabling power status reporting.\n");
1973 	return 0;
1974 }
1975 
1976 /*
1977  * This bios swaps the APM minute reporting bytes over (Many sony laptops
1978  * have this problem).
1979  */
1980 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
1981 {
1982 	apm_info.get_power_status_swabinminutes = 1;
1983 	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
1984 	       "in minutes and wrong byte order.\n");
1985 	return 0;
1986 }
1987 
1988 static struct dmi_system_id __initdata apm_dmi_table[] = {
1989 	{
1990 		print_if_true,
1991 		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
1992 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
1993 			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
1994 	},
1995 	{	/* Handle problems with APM on the C600 */
1996 		broken_ps2_resume, "Dell Latitude C600",
1997 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
1998 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
1999 	},
2000 	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2001 		set_apm_ints, "Dell Latitude",
2002 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2003 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2004 	},
2005 	{	/* APM crashes */
2006 		apm_is_horked, "Dell Inspiron 2500",
2007 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2008 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2009 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2010 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2011 	},
2012 	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2013 		set_apm_ints, "Dell Inspiron", {
2014 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2015 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2016 	},
2017 	{	/* Handle problems with APM on Inspiron 5000e */
2018 		broken_apm_power, "Dell Inspiron 5000e",
2019 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2020 			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2021 			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2022 	},
2023 	{	/* Handle problems with APM on Inspiron 2500 */
2024 		broken_apm_power, "Dell Inspiron 2500",
2025 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2026 			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2027 			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2028 	},
2029 	{	/* APM crashes */
2030 		apm_is_horked, "Dell Dimension 4100",
2031 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2032 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2033 			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2034 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2035 	},
2036 	{	/* Allow interrupts during suspend on Compaq Laptops*/
2037 		set_apm_ints, "Compaq 12XL125",
2038 		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2039 			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2040 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2041 			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2042 	},
2043 	{	/* Allow interrupts during APM or the clock goes slow */
2044 		set_apm_ints, "ASUSTeK",
2045 		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2046 			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2047 	},
2048 	{	/* APM blows on shutdown */
2049 		apm_is_horked, "ABIT KX7-333[R]",
2050 		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2051 			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2052 	},
2053 	{	/* APM crashes */
2054 		apm_is_horked, "Trigem Delhi3",
2055 		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2056 			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2057 	},
2058 	{	/* APM crashes */
2059 		apm_is_horked, "Fujitsu-Siemens",
2060 		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2061 			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2062 	},
2063 	{	/* APM crashes */
2064 		apm_is_horked_d850md, "Intel D850MD",
2065 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2066 			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2067 	},
2068 	{	/* APM crashes */
2069 		apm_is_horked, "Intel D810EMO",
2070 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2071 			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2072 	},
2073 	{	/* APM crashes */
2074 		apm_is_horked, "Dell XPS-Z",
2075 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2076 			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2077 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2078 	},
2079 	{	/* APM crashes */
2080 		apm_is_horked, "Sharp PC-PJ/AX",
2081 		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2082 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2083 			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2084 			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2085 	},
2086 	{	/* APM crashes */
2087 		apm_is_horked, "Dell Inspiron 2500",
2088 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2089 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2090 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2091 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2092 	},
2093 	{	/* APM idle hangs */
2094 		apm_likes_to_melt, "Jabil AMD",
2095 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2096 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2097 	},
2098 	{	/* APM idle hangs */
2099 		apm_likes_to_melt, "AMI Bios",
2100 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2101 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2102 	},
2103 	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2104 		swab_apm_power_in_minutes, "Sony VAIO",
2105 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2106 			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2107 			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2108 	},
2109 	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2110 		swab_apm_power_in_minutes, "Sony VAIO",
2111 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2112 			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2113 			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2114 	},
2115 	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2116 		swab_apm_power_in_minutes, "Sony VAIO",
2117 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2118 			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2119 			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2120 	},
2121 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2122 		swab_apm_power_in_minutes, "Sony VAIO",
2123 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2124 			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2125 			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2126 	},
2127 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2128 		swab_apm_power_in_minutes, "Sony VAIO",
2129 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2130 			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2131 			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2132 	},
2133 	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2134 		swab_apm_power_in_minutes, "Sony VAIO",
2135 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2136 			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2137 			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2138 	},
2139 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2140 		swab_apm_power_in_minutes, "Sony VAIO",
2141 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2142 			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2143 			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2144 	},
2145 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2146 		swab_apm_power_in_minutes, "Sony VAIO",
2147 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2148 			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2149 			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2150 	},
2151 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2152 		swab_apm_power_in_minutes, "Sony VAIO",
2153 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2154 			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2155 			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2156 	},
2157 	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2158 		swab_apm_power_in_minutes, "Sony VAIO",
2159 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2160 			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2161 			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2162 	},
2163 
2164 	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2165 		swab_apm_power_in_minutes, "Sony VAIO",
2166 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2167 			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2168 			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2169 	},
2170 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2171 		swab_apm_power_in_minutes, "Sony VAIO",
2172 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2173 			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2174 			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2175 	},
2176 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2177 		swab_apm_power_in_minutes, "Sony VAIO",
2178 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2179 			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2180 			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2181 	},
2182 	{	/* broken PM poweroff bios */
2183 		set_realmode_power_off, "Award Software v4.60 PGMA",
2184 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2185 			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2186 			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2187 	},
2188 
2189 	/* Generic per vendor APM settings  */
2190 
2191 	{	/* Allow interrupts during suspend on IBM laptops */
2192 		set_apm_ints, "IBM",
2193 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2194 	},
2195 
2196 	{ }
2197 };
2198 
2199 /*
2200  * Just start the APM thread. We do NOT want to do APM BIOS
2201  * calls from anything but the APM thread, if for no other reason
2202  * than the fact that we don't trust the APM BIOS. This way,
2203  * most common APM BIOS problems that lead to protection errors
2204  * etc will have at least some level of being contained...
2205  *
2206  * In short, if something bad happens, at least we have a choice
2207  * of just killing the apm thread..
2208  */
2209 static int __init apm_init(void)
2210 {
2211 	struct desc_struct *gdt;
2212 	int err;
2213 
2214 	dmi_check_system(apm_dmi_table);
2215 
2216 	if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2217 		printk(KERN_INFO "apm: BIOS not found.\n");
2218 		return -ENODEV;
2219 	}
2220 	printk(KERN_INFO
2221 	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2222 	       ((apm_info.bios.version >> 8) & 0xff),
2223 	       (apm_info.bios.version & 0xff),
2224 	       apm_info.bios.flags,
2225 	       driver_version);
2226 	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2227 		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2228 		return -ENODEV;
2229 	}
2230 
2231 	if (allow_ints)
2232 		apm_info.allow_ints = 1;
2233 	if (broken_psr)
2234 		apm_info.get_power_status_broken = 1;
2235 	if (realmode_power_off)
2236 		apm_info.realmode_power_off = 1;
2237 	/* User can override, but default is to trust DMI */
2238 	if (apm_disabled != -1)
2239 		apm_info.disabled = apm_disabled;
2240 
2241 	/*
2242 	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2243 	 * but is reportedly a 1.0 BIOS.
2244 	 */
2245 	if (apm_info.bios.version == 0x001)
2246 		apm_info.bios.version = 0x100;
2247 
2248 	/* BIOS < 1.2 doesn't set cseg_16_len */
2249 	if (apm_info.bios.version < 0x102)
2250 		apm_info.bios.cseg_16_len = 0; /* 64k */
2251 
2252 	if (debug) {
2253 		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2254 			apm_info.bios.cseg, apm_info.bios.offset,
2255 			apm_info.bios.cseg_16, apm_info.bios.dseg);
2256 		if (apm_info.bios.version > 0x100)
2257 			printk(" cseg len %x, dseg len %x",
2258 				apm_info.bios.cseg_len,
2259 				apm_info.bios.dseg_len);
2260 		if (apm_info.bios.version > 0x101)
2261 			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2262 		printk("\n");
2263 	}
2264 
2265 	if (apm_info.disabled) {
2266 		printk(KERN_NOTICE "apm: disabled on user request.\n");
2267 		return -ENODEV;
2268 	}
2269 	if ((num_online_cpus() > 1) && !power_off && !smp) {
2270 		printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2271 		apm_info.disabled = 1;
2272 		return -ENODEV;
2273 	}
2274 	if (pm_flags & PM_ACPI) {
2275 		printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2276 		apm_info.disabled = 1;
2277 		return -ENODEV;
2278 	}
2279 	pm_flags |= PM_APM;
2280 
2281 	/*
2282 	 * Set up a segment that references the real mode segment 0x40
2283 	 * that extends up to the end of page zero (that we have reserved).
2284 	 * This is for buggy BIOS's that refer to (real mode) segment 0x40
2285 	 * even though they are called in protected mode.
2286 	 */
2287 	set_base(bad_bios_desc, __va((unsigned long)0x40 << 4));
2288 	_set_limit((char *)&bad_bios_desc, 4095 - (0x40 << 4));
2289 
2290 	/*
2291 	 * Set up the long jump entry point to the APM BIOS, which is called
2292 	 * from inline assembly.
2293 	 */
2294 	apm_bios_entry.offset = apm_info.bios.offset;
2295 	apm_bios_entry.segment = APM_CS;
2296 
2297 	/*
2298 	 * The APM 1.1 BIOS is supposed to provide limit information that it
2299 	 * recognizes.  Many machines do this correctly, but many others do
2300 	 * not restrict themselves to their claimed limit.  When this happens,
2301 	 * they will cause a segmentation violation in the kernel at boot time.
2302 	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2303 	 *
2304 	 * Note we only set APM segments on CPU zero, since we pin the APM
2305 	 * code to that CPU.
2306 	 */
2307 	gdt = get_cpu_gdt_table(0);
2308 	set_base(gdt[APM_CS >> 3],
2309 		 __va((unsigned long)apm_info.bios.cseg << 4));
2310 	set_base(gdt[APM_CS_16 >> 3],
2311 		 __va((unsigned long)apm_info.bios.cseg_16 << 4));
2312 	set_base(gdt[APM_DS >> 3],
2313 		 __va((unsigned long)apm_info.bios.dseg << 4));
2314 
2315 	proc_create("apm", 0, NULL, &apm_file_ops);
2316 
2317 	kapmd_task = kthread_create(apm, NULL, "kapmd");
2318 	if (IS_ERR(kapmd_task)) {
2319 		printk(KERN_ERR "apm: disabled - Unable to start kernel "
2320 				"thread.\n");
2321 		err = PTR_ERR(kapmd_task);
2322 		kapmd_task = NULL;
2323 		remove_proc_entry("apm", NULL);
2324 		return err;
2325 	}
2326 	wake_up_process(kapmd_task);
2327 
2328 	if (num_online_cpus() > 1 && !smp) {
2329 		printk(KERN_NOTICE
2330 		       "apm: disabled - APM is not SMP safe (power off active).\n");
2331 		return 0;
2332 	}
2333 
2334 	/*
2335 	 * Note we don't actually care if the misc_device cannot be registered.
2336 	 * this driver can do its job without it, even if userspace can't
2337 	 * control it.  just log the error
2338 	 */
2339 	if (misc_register(&apm_device))
2340 		printk(KERN_WARNING "apm: Could not register misc device.\n");
2341 
2342 	if (HZ != 100)
2343 		idle_period = (idle_period * HZ) / 100;
2344 	if (idle_threshold < 100) {
2345 		original_pm_idle = pm_idle;
2346 		pm_idle  = apm_cpu_idle;
2347 		set_pm_idle = 1;
2348 	}
2349 
2350 	return 0;
2351 }
2352 
2353 static void __exit apm_exit(void)
2354 {
2355 	int error;
2356 
2357 	if (set_pm_idle) {
2358 		pm_idle = original_pm_idle;
2359 		/*
2360 		 * We are about to unload the current idle thread pm callback
2361 		 * (pm_idle), Wait for all processors to update cached/local
2362 		 * copies of pm_idle before proceeding.
2363 		 */
2364 		cpu_idle_wait();
2365 	}
2366 	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2367 	    && (apm_info.connection_version > 0x0100)) {
2368 		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2369 		if (error)
2370 			apm_error("disengage power management", error);
2371 	}
2372 	misc_deregister(&apm_device);
2373 	remove_proc_entry("apm", NULL);
2374 	if (power_off)
2375 		pm_power_off = NULL;
2376 	if (kapmd_task) {
2377 		kthread_stop(kapmd_task);
2378 		kapmd_task = NULL;
2379 	}
2380 	pm_flags &= ~PM_APM;
2381 }
2382 
2383 module_init(apm_init);
2384 module_exit(apm_exit);
2385 
2386 MODULE_AUTHOR("Stephen Rothwell");
2387 MODULE_DESCRIPTION("Advanced Power Management");
2388 MODULE_LICENSE("GPL");
2389 module_param(debug, bool, 0644);
2390 MODULE_PARM_DESC(debug, "Enable debug mode");
2391 module_param(power_off, bool, 0444);
2392 MODULE_PARM_DESC(power_off, "Enable power off");
2393 module_param(bounce_interval, int, 0444);
2394 MODULE_PARM_DESC(bounce_interval,
2395 		"Set the number of ticks to ignore suspend bounces");
2396 module_param(allow_ints, bool, 0444);
2397 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2398 module_param(broken_psr, bool, 0444);
2399 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2400 module_param(realmode_power_off, bool, 0444);
2401 MODULE_PARM_DESC(realmode_power_off,
2402 		"Switch to real mode before powering off");
2403 module_param(idle_threshold, int, 0444);
2404 MODULE_PARM_DESC(idle_threshold,
2405 	"System idle percentage above which to make APM BIOS idle calls");
2406 module_param(idle_period, int, 0444);
2407 MODULE_PARM_DESC(idle_period,
2408 	"Period (in sec/100) over which to caculate the idle percentage");
2409 module_param(smp, bool, 0444);
2410 MODULE_PARM_DESC(smp,
2411 	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2412 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
2413