xref: /openbmc/linux/arch/x86/kernel/apm_32.c (revision c67e8ec0)
1 /* -*- linux-c -*-
2  * APM BIOS driver for Linux
3  * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
4  *
5  * Initial development of this driver was funded by NEC Australia P/L
6  *	and NEC Corporation
7  *
8  * This program is free software; you can redistribute it and/or modify it
9  * under the terms of the GNU General Public License as published by the
10  * Free Software Foundation; either version 2, or (at your option) any
11  * later version.
12  *
13  * This program is distributed in the hope that it will be useful, but
14  * WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * General Public License for more details.
17  *
18  * October 1995, Rik Faith (faith@cs.unc.edu):
19  *    Minor enhancements and updates (to the patch set) for 1.3.x
20  *    Documentation
21  * January 1996, Rik Faith (faith@cs.unc.edu):
22  *    Make /proc/apm easy to format (bump driver version)
23  * March 1996, Rik Faith (faith@cs.unc.edu):
24  *    Prohibit APM BIOS calls unless apm_enabled.
25  *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
26  * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
27  *    Version 1.0 and 1.1
28  * May 1996, Version 1.2
29  * Feb 1998, Version 1.3
30  * Feb 1998, Version 1.4
31  * Aug 1998, Version 1.5
32  * Sep 1998, Version 1.6
33  * Nov 1998, Version 1.7
34  * Jan 1999, Version 1.8
35  * Jan 1999, Version 1.9
36  * Oct 1999, Version 1.10
37  * Nov 1999, Version 1.11
38  * Jan 2000, Version 1.12
39  * Feb 2000, Version 1.13
40  * Nov 2000, Version 1.14
41  * Oct 2001, Version 1.15
42  * Jan 2002, Version 1.16
43  * Oct 2002, Version 1.16ac
44  *
45  * History:
46  *    0.6b: first version in official kernel, Linux 1.3.46
47  *    0.7: changed /proc/apm format, Linux 1.3.58
48  *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
49  *    0.9: only call bios if bios is present, Linux 1.3.72
50  *    1.0: use fixed device number, consolidate /proc/apm into this file,
51  *         Linux 1.3.85
52  *    1.1: support user-space standby and suspend, power off after system
53  *         halted, Linux 1.3.98
54  *    1.2: When resetting RTC after resume, take care so that the time
55  *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
56  *         <jtoth@princeton.edu>); improve interaction between
57  *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
58  *    1.2a:Simple change to stop mysterious bug reports with SMP also added
59  *	   levels to the printk calls. APM is not defined for SMP machines.
60  *         The new replacement for it is, but Linux doesn't yet support this.
61  *         Alan Cox Linux 2.1.55
62  *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
63  *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
64  *         Dean Gaudet <dgaudet@arctic.org>.
65  *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
66  *    1.5: Fix segment register reloading (in case of bad segments saved
67  *         across BIOS call).
68  *         Stephen Rothwell
69  *    1.6: Cope with compiler/assembler differences.
70  *         Only try to turn off the first display device.
71  *         Fix OOPS at power off with no APM BIOS by Jan Echternach
72  *                   <echter@informatik.uni-rostock.de>
73  *         Stephen Rothwell
74  *    1.7: Modify driver's cached copy of the disabled/disengaged flags
75  *         to reflect current state of APM BIOS.
76  *         Chris Rankin <rankinc@bellsouth.net>
77  *         Reset interrupt 0 timer to 100Hz after suspend
78  *         Chad Miller <cmiller@surfsouth.com>
79  *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
80  *         Richard Gooch <rgooch@atnf.csiro.au>
81  *         Allow boot time disabling of APM
82  *         Make boot messages far less verbose by default
83  *         Make asm safer
84  *         Stephen Rothwell
85  *    1.8: Add CONFIG_APM_RTC_IS_GMT
86  *         Richard Gooch <rgooch@atnf.csiro.au>
87  *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
88  *         remove dependency on CONFIG_PROC_FS
89  *         Stephen Rothwell
90  *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
91  *         Try to cope with BIOS's that need to have all display
92  *         devices blanked and not just the first one.
93  *         Ross Paterson <ross@soi.city.ac.uk>
94  *         Fix segment limit setting it has always been wrong as
95  *         the segments needed to have byte granularity.
96  *         Mark a few things __init.
97  *         Add hack to allow power off of SMP systems by popular request.
98  *         Use CONFIG_SMP instead of __SMP__
99  *         Ignore BOUNCES for three seconds.
100  *         Stephen Rothwell
101  *   1.10: Fix for Thinkpad return code.
102  *         Merge 2.2 and 2.3 drivers.
103  *         Remove APM dependencies in arch/i386/kernel/process.c
104  *         Remove APM dependencies in drivers/char/sysrq.c
105  *         Reset time across standby.
106  *         Allow more inititialisation on SMP.
107  *         Remove CONFIG_APM_POWER_OFF and make it boot time
108  *         configurable (default on).
109  *         Make debug only a boot time parameter (remove APM_DEBUG).
110  *         Try to blank all devices on any error.
111  *   1.11: Remove APM dependencies in drivers/char/console.c
112  *         Check nr_running to detect if we are idle (from
113  *         Borislav Deianov <borislav@lix.polytechnique.fr>)
114  *         Fix for bioses that don't zero the top part of the
115  *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
116  *         (reported by Panos Katsaloulis <teras@writeme.com>).
117  *         Real mode power off patch (Walter Hofmann
118  *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
119  *   1.12: Remove CONFIG_SMP as the compiler will optimize
120  *         the code away anyway (smp_num_cpus == 1 in UP)
121  *         noted by Artur Skawina <skawina@geocities.com>.
122  *         Make power off under SMP work again.
123  *         Fix thinko with initial engaging of BIOS.
124  *         Make sure power off only happens on CPU 0
125  *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
126  *         Do error notification to user mode if BIOS calls fail.
127  *         Move entrypoint offset fix to ...boot/setup.S
128  *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
129  *         Remove smp-power-off. SMP users must now specify
130  *         "apm=power-off" on the kernel command line. Suggested
131  *         by Jim Avera <jima@hal.com>, modified by Alan Cox
132  *         <alan@lxorguk.ukuu.org.uk>.
133  *         Register the /proc/apm entry even on SMP so that
134  *         scripts that check for it before doing power off
135  *         work (Jim Avera <jima@hal.com>).
136  *   1.13: Changes for new pm_ interfaces (Andy Henroid
137  *         <andy_henroid@yahoo.com>).
138  *         Modularize the code.
139  *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
140  *         is now the way life works).
141  *         Fix thinko in suspend() (wrong return).
142  *         Notify drivers on critical suspend.
143  *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
144  *         modified by sfr).
145  *         Disable interrupts while we are suspended (Andy Henroid
146  *         <andy_henroid@yahoo.com> fixed by sfr).
147  *         Make power off work on SMP again (Tony Hoyle
148  *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
149  *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
150  *         interval is now configurable.
151  *   1.14: Make connection version persist across module unload/load.
152  *         Enable and engage power management earlier.
153  *         Disengage power management on module unload.
154  *         Changed to use the sysrq-register hack for registering the
155  *         power off function called by magic sysrq based upon discussions
156  *         in irc://irc.openprojects.net/#kernelnewbies
157  *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
158  *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
159  *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
160  *         Work around byte swap bug in one of the Vaio's BIOS's
161  *         (Marc Boucher <marc@mbsi.ca>).
162  *         Exposed the disable flag to dmi so that we can handle known
163  *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
164  *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
165  *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
166  *         If an APM idle fails log it and idle sensibly
167  *   1.15: Don't queue events to clients who open the device O_WRONLY.
168  *         Don't expect replies from clients who open the device O_RDONLY.
169  *         (Idea from Thomas Hood)
170  *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
171  *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
172  *         Notify listeners of standby or suspend events before notifying
173  *         drivers. Return EBUSY to ioctl() if suspend is rejected.
174  *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
175  *         Ignore first resume after we generate our own resume event
176  *         after a suspend (Thomas Hood)
177  *         Daemonize now gets rid of our controlling terminal (sfr).
178  *         CONFIG_APM_CPU_IDLE now just affects the default value of
179  *         idle_threshold (sfr).
180  *         Change name of kernel apm daemon (as it no longer idles) (sfr).
181  *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
182  *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
183  *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
184  *
185  * APM 1.1 Reference:
186  *
187  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
188  *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
189  *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
190  *
191  * [This document is available free from Intel by calling 800.628.8686 (fax
192  * 916.356.6100) or 800.548.4725; or from
193  * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
194  * available from Microsoft by calling 206.882.8080.]
195  *
196  * APM 1.2 Reference:
197  *   Intel Corporation, Microsoft Corporation. Advanced Power Management
198  *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
199  *
200  * [This document is available from Microsoft at:
201  *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
202  */
203 
204 #define pr_fmt(fmt) "apm: " fmt
205 
206 #include <linux/module.h>
207 
208 #include <linux/poll.h>
209 #include <linux/types.h>
210 #include <linux/stddef.h>
211 #include <linux/timer.h>
212 #include <linux/fcntl.h>
213 #include <linux/slab.h>
214 #include <linux/stat.h>
215 #include <linux/proc_fs.h>
216 #include <linux/seq_file.h>
217 #include <linux/miscdevice.h>
218 #include <linux/apm_bios.h>
219 #include <linux/init.h>
220 #include <linux/time.h>
221 #include <linux/sched/signal.h>
222 #include <linux/sched/cputime.h>
223 #include <linux/pm.h>
224 #include <linux/capability.h>
225 #include <linux/device.h>
226 #include <linux/kernel.h>
227 #include <linux/freezer.h>
228 #include <linux/smp.h>
229 #include <linux/dmi.h>
230 #include <linux/suspend.h>
231 #include <linux/kthread.h>
232 #include <linux/jiffies.h>
233 #include <linux/acpi.h>
234 #include <linux/syscore_ops.h>
235 #include <linux/i8253.h>
236 #include <linux/cpuidle.h>
237 
238 #include <linux/uaccess.h>
239 #include <asm/desc.h>
240 #include <asm/olpc.h>
241 #include <asm/paravirt.h>
242 #include <asm/reboot.h>
243 #include <asm/nospec-branch.h>
244 
245 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
246 extern int (*console_blank_hook)(int);
247 #endif
248 
249 /*
250  * The apm_bios device is one of the misc char devices.
251  * This is its minor number.
252  */
253 #define	APM_MINOR_DEV	134
254 
255 /*
256  * Various options can be changed at boot time as follows:
257  * (We allow underscores for compatibility with the modules code)
258  *	apm=on/off			enable/disable APM
259  *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
260  *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
261  *	    [no-]realmode[-_]power[-_]off	switch to real mode before
262  *	    					powering off
263  *	    [no-]debug			log some debugging messages
264  *	    [no-]power[-_]off		power off on shutdown
265  *	    [no-]smp			Use apm even on an SMP box
266  *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
267  *	    				bounces
268  *          idle[-_]threshold=<n>       System idle percentage above which to
269  *                                      make APM BIOS idle calls. Set it to
270  *                                      100 to disable.
271  *          idle[-_]period=<n>          Period (in 1/100s of a second) over
272  *                                      which the idle percentage is
273  *                                      calculated.
274  */
275 
276 /* KNOWN PROBLEM MACHINES:
277  *
278  * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
279  *                         [Confirmed by TI representative]
280  * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
281  *                    [Confirmed by BIOS disassembly]
282  *                    [This may work now ...]
283  * P: Toshiba 1950S: battery life information only gets updated after resume
284  * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
285  * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
286  * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
287  * 	Neale Banks <neale@lowendale.com.au> December 2000
288  *
289  * Legend: U = unusable with APM patches
290  *         P = partially usable with APM patches
291  */
292 
293 /*
294  * Define as 1 to make the driver always call the APM BIOS busy
295  * routine even if the clock was not reported as slowed by the
296  * idle routine.  Otherwise, define as 0.
297  */
298 #define ALWAYS_CALL_BUSY   1
299 
300 /*
301  * Define to make the APM BIOS calls zero all data segment registers (so
302  * that an incorrect BIOS implementation will cause a kernel panic if it
303  * tries to write to arbitrary memory).
304  */
305 #define APM_ZERO_SEGS
306 
307 #include <asm/apm.h>
308 
309 /*
310  * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
311  * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
312  * David Chen <chen@ctpa04.mit.edu>
313  */
314 #undef INIT_TIMER_AFTER_SUSPEND
315 
316 #ifdef INIT_TIMER_AFTER_SUSPEND
317 #include <linux/timex.h>
318 #include <asm/io.h>
319 #include <linux/delay.h>
320 #endif
321 
322 /*
323  * Need to poll the APM BIOS every second
324  */
325 #define APM_CHECK_TIMEOUT	(HZ)
326 
327 /*
328  * Ignore suspend events for this amount of time after a resume
329  */
330 #define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
331 
332 /*
333  * Maximum number of events stored
334  */
335 #define APM_MAX_EVENTS		20
336 
337 /*
338  * The per-file APM data
339  */
340 struct apm_user {
341 	int		magic;
342 	struct apm_user *next;
343 	unsigned int	suser: 1;
344 	unsigned int	writer: 1;
345 	unsigned int	reader: 1;
346 	unsigned int	suspend_wait: 1;
347 	int		suspend_result;
348 	int		suspends_pending;
349 	int		standbys_pending;
350 	int		suspends_read;
351 	int		standbys_read;
352 	int		event_head;
353 	int		event_tail;
354 	apm_event_t	events[APM_MAX_EVENTS];
355 };
356 
357 /*
358  * The magic number in apm_user
359  */
360 #define APM_BIOS_MAGIC		0x4101
361 
362 /*
363  * idle percentage above which bios idle calls are done
364  */
365 #ifdef CONFIG_APM_CPU_IDLE
366 #define DEFAULT_IDLE_THRESHOLD	95
367 #else
368 #define DEFAULT_IDLE_THRESHOLD	100
369 #endif
370 #define DEFAULT_IDLE_PERIOD	(100 / 3)
371 
372 static int apm_cpu_idle(struct cpuidle_device *dev,
373 			struct cpuidle_driver *drv, int index);
374 
375 static struct cpuidle_driver apm_idle_driver = {
376 	.name = "apm_idle",
377 	.owner = THIS_MODULE,
378 	.states = {
379 		{ /* entry 0 is for polling */ },
380 		{ /* entry 1 is for APM idle */
381 			.name = "APM",
382 			.desc = "APM idle",
383 			.exit_latency = 250,	/* WAG */
384 			.target_residency = 500,	/* WAG */
385 			.enter = &apm_cpu_idle
386 		},
387 	},
388 	.state_count = 2,
389 };
390 
391 static struct cpuidle_device apm_cpuidle_device;
392 
393 /*
394  * Local variables
395  */
396 __visible struct {
397 	unsigned long	offset;
398 	unsigned short	segment;
399 } apm_bios_entry;
400 static int clock_slowed;
401 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
402 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
403 static int suspends_pending;
404 static int standbys_pending;
405 static int ignore_sys_suspend;
406 static int ignore_normal_resume;
407 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
408 
409 static bool debug __read_mostly;
410 static bool smp __read_mostly;
411 static int apm_disabled = -1;
412 #ifdef CONFIG_SMP
413 static bool power_off;
414 #else
415 static bool power_off = 1;
416 #endif
417 static bool realmode_power_off;
418 #ifdef CONFIG_APM_ALLOW_INTS
419 static bool allow_ints = 1;
420 #else
421 static bool allow_ints;
422 #endif
423 static bool broken_psr;
424 
425 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
426 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
427 static struct apm_user *user_list;
428 static DEFINE_SPINLOCK(user_list_lock);
429 static DEFINE_MUTEX(apm_mutex);
430 
431 /*
432  * Set up a segment that references the real mode segment 0x40
433  * that extends up to the end of page zero (that we have reserved).
434  * This is for buggy BIOS's that refer to (real mode) segment 0x40
435  * even though they are called in protected mode.
436  */
437 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
438 			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
439 
440 static const char driver_version[] = "1.16ac";	/* no spaces */
441 
442 static struct task_struct *kapmd_task;
443 
444 /*
445  *	APM event names taken from the APM 1.2 specification. These are
446  *	the message codes that the BIOS uses to tell us about events
447  */
448 static const char * const apm_event_name[] = {
449 	"system standby",
450 	"system suspend",
451 	"normal resume",
452 	"critical resume",
453 	"low battery",
454 	"power status change",
455 	"update time",
456 	"critical suspend",
457 	"user standby",
458 	"user suspend",
459 	"system standby resume",
460 	"capabilities change"
461 };
462 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
463 
464 typedef struct lookup_t {
465 	int	key;
466 	char 	*msg;
467 } lookup_t;
468 
469 /*
470  *	The BIOS returns a set of standard error codes in AX when the
471  *	carry flag is set.
472  */
473 
474 static const lookup_t error_table[] = {
475 /* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
476 	{ APM_DISABLED,		"Power management disabled" },
477 	{ APM_CONNECTED,	"Real mode interface already connected" },
478 	{ APM_NOT_CONNECTED,	"Interface not connected" },
479 	{ APM_16_CONNECTED,	"16 bit interface already connected" },
480 /* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
481 	{ APM_32_CONNECTED,	"32 bit interface already connected" },
482 	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
483 	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
484 	{ APM_BAD_PARAM,	"Parameter out of range" },
485 	{ APM_NOT_ENGAGED,	"Interface not engaged" },
486 	{ APM_BAD_FUNCTION,     "Function not supported" },
487 	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
488 	{ APM_BAD_STATE,	"Unable to enter requested state" },
489 /* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
490 	{ APM_NO_ERROR,		"BIOS did not set a return code" },
491 	{ APM_NOT_PRESENT,	"No APM present" }
492 };
493 #define ERROR_COUNT	ARRAY_SIZE(error_table)
494 
495 /**
496  *	apm_error	-	display an APM error
497  *	@str: information string
498  *	@err: APM BIOS return code
499  *
500  *	Write a meaningful log entry to the kernel log in the event of
501  *	an APM error.  Note that this also handles (negative) kernel errors.
502  */
503 
504 static void apm_error(char *str, int err)
505 {
506 	int i;
507 
508 	for (i = 0; i < ERROR_COUNT; i++)
509 		if (error_table[i].key == err)
510 			break;
511 	if (i < ERROR_COUNT)
512 		pr_notice("%s: %s\n", str, error_table[i].msg);
513 	else if (err < 0)
514 		pr_notice("%s: linux error code %i\n", str, err);
515 	else
516 		pr_notice("%s: unknown error code %#2.2x\n",
517 		       str, err);
518 }
519 
520 /*
521  * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
522  * apm_info.allow_ints, we are being really paranoid here!  Not only
523  * are interrupts disabled, but all the segment registers (except SS)
524  * are saved and zeroed this means that if the BIOS tries to reference
525  * any data without explicitly loading the segment registers, the kernel
526  * will fault immediately rather than have some unforeseen circumstances
527  * for the rest of the kernel.  And it will be very obvious!  :-) Doing
528  * this depends on CS referring to the same physical memory as DS so that
529  * DS can be zeroed before the call. Unfortunately, we can't do anything
530  * about the stack segment/pointer.  Also, we tell the compiler that
531  * everything could change.
532  *
533  * Also, we KNOW that for the non error case of apm_bios_call, there
534  * is no useful data returned in the low order 8 bits of eax.
535  */
536 
537 static inline unsigned long __apm_irq_save(void)
538 {
539 	unsigned long flags;
540 	local_save_flags(flags);
541 	if (apm_info.allow_ints) {
542 		if (irqs_disabled_flags(flags))
543 			local_irq_enable();
544 	} else
545 		local_irq_disable();
546 
547 	return flags;
548 }
549 
550 #define apm_irq_save(flags) \
551 	do { flags = __apm_irq_save(); } while (0)
552 
553 static inline void apm_irq_restore(unsigned long flags)
554 {
555 	if (irqs_disabled_flags(flags))
556 		local_irq_disable();
557 	else if (irqs_disabled())
558 		local_irq_enable();
559 }
560 
561 #ifdef APM_ZERO_SEGS
562 #	define APM_DECL_SEGS \
563 		unsigned int saved_fs; unsigned int saved_gs;
564 #	define APM_DO_SAVE_SEGS \
565 		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
566 #	define APM_DO_RESTORE_SEGS \
567 		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
568 #else
569 #	define APM_DECL_SEGS
570 #	define APM_DO_SAVE_SEGS
571 #	define APM_DO_RESTORE_SEGS
572 #endif
573 
574 struct apm_bios_call {
575 	u32 func;
576 	/* In and out */
577 	u32 ebx;
578 	u32 ecx;
579 	/* Out only */
580 	u32 eax;
581 	u32 edx;
582 	u32 esi;
583 
584 	/* Error: -ENOMEM, or bits 8-15 of eax */
585 	int err;
586 };
587 
588 /**
589  *	__apm_bios_call - Make an APM BIOS 32bit call
590  *	@_call: pointer to struct apm_bios_call.
591  *
592  *	Make an APM call using the 32bit protected mode interface. The
593  *	caller is responsible for knowing if APM BIOS is configured and
594  *	enabled. This call can disable interrupts for a long period of
595  *	time on some laptops.  The return value is in AH and the carry
596  *	flag is loaded into AL.  If there is an error, then the error
597  *	code is returned in AH (bits 8-15 of eax) and this function
598  *	returns non-zero.
599  *
600  *	Note: this makes the call on the current CPU.
601  */
602 static long __apm_bios_call(void *_call)
603 {
604 	APM_DECL_SEGS
605 	unsigned long		flags;
606 	int			cpu;
607 	struct desc_struct	save_desc_40;
608 	struct desc_struct	*gdt;
609 	struct apm_bios_call	*call = _call;
610 
611 	cpu = get_cpu();
612 	BUG_ON(cpu != 0);
613 	gdt = get_cpu_gdt_rw(cpu);
614 	save_desc_40 = gdt[0x40 / 8];
615 	gdt[0x40 / 8] = bad_bios_desc;
616 
617 	apm_irq_save(flags);
618 	firmware_restrict_branch_speculation_start();
619 	APM_DO_SAVE_SEGS;
620 	apm_bios_call_asm(call->func, call->ebx, call->ecx,
621 			  &call->eax, &call->ebx, &call->ecx, &call->edx,
622 			  &call->esi);
623 	APM_DO_RESTORE_SEGS;
624 	firmware_restrict_branch_speculation_end();
625 	apm_irq_restore(flags);
626 	gdt[0x40 / 8] = save_desc_40;
627 	put_cpu();
628 
629 	return call->eax & 0xff;
630 }
631 
632 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
633 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
634 {
635 	int ret;
636 
637 	/* Don't bother with work_on_cpu in the common case, so we don't
638 	 * have to worry about OOM or overhead. */
639 	if (get_cpu() == 0) {
640 		ret = fn(call);
641 		put_cpu();
642 	} else {
643 		put_cpu();
644 		ret = work_on_cpu(0, fn, call);
645 	}
646 
647 	/* work_on_cpu can fail with -ENOMEM */
648 	if (ret < 0)
649 		call->err = ret;
650 	else
651 		call->err = (call->eax >> 8) & 0xff;
652 
653 	return ret;
654 }
655 
656 /**
657  *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
658  *	@call: the apm_bios_call registers.
659  *
660  *	If there is an error, it is returned in @call.err.
661  */
662 static int apm_bios_call(struct apm_bios_call *call)
663 {
664 	return on_cpu0(__apm_bios_call, call);
665 }
666 
667 /**
668  *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
669  *	@_call: pointer to struct apm_bios_call.
670  *
671  *	Make a BIOS call that returns one value only, or just status.
672  *	If there is an error, then the error code is returned in AH
673  *	(bits 8-15 of eax) and this function returns non-zero (it can
674  *	also return -ENOMEM). This is used for simpler BIOS operations.
675  *	This call may hold interrupts off for a long time on some laptops.
676  *
677  *	Note: this makes the call on the current CPU.
678  */
679 static long __apm_bios_call_simple(void *_call)
680 {
681 	u8			error;
682 	APM_DECL_SEGS
683 	unsigned long		flags;
684 	int			cpu;
685 	struct desc_struct	save_desc_40;
686 	struct desc_struct	*gdt;
687 	struct apm_bios_call	*call = _call;
688 
689 	cpu = get_cpu();
690 	BUG_ON(cpu != 0);
691 	gdt = get_cpu_gdt_rw(cpu);
692 	save_desc_40 = gdt[0x40 / 8];
693 	gdt[0x40 / 8] = bad_bios_desc;
694 
695 	apm_irq_save(flags);
696 	firmware_restrict_branch_speculation_start();
697 	APM_DO_SAVE_SEGS;
698 	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
699 					 &call->eax);
700 	APM_DO_RESTORE_SEGS;
701 	firmware_restrict_branch_speculation_end();
702 	apm_irq_restore(flags);
703 	gdt[0x40 / 8] = save_desc_40;
704 	put_cpu();
705 	return error;
706 }
707 
708 /**
709  *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
710  *	@func: APM function to invoke
711  *	@ebx_in: EBX register value for BIOS call
712  *	@ecx_in: ECX register value for BIOS call
713  *	@eax: EAX register on return from the BIOS call
714  *	@err: bits
715  *
716  *	Make a BIOS call that returns one value only, or just status.
717  *	If there is an error, then the error code is returned in @err
718  *	and this function returns non-zero. This is used for simpler
719  *	BIOS operations.  This call may hold interrupts off for a long
720  *	time on some laptops.
721  */
722 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
723 				int *err)
724 {
725 	struct apm_bios_call call;
726 	int ret;
727 
728 	call.func = func;
729 	call.ebx = ebx_in;
730 	call.ecx = ecx_in;
731 
732 	ret = on_cpu0(__apm_bios_call_simple, &call);
733 	*eax = call.eax;
734 	*err = call.err;
735 	return ret;
736 }
737 
738 /**
739  *	apm_driver_version	-	APM driver version
740  *	@val:	loaded with the APM version on return
741  *
742  *	Retrieve the APM version supported by the BIOS. This is only
743  *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
744  *	probably present.
745  *
746  *	On entry val should point to a value indicating the APM driver
747  *	version with the high byte being the major and the low byte the
748  *	minor number both in BCD
749  *
750  *	On return it will hold the BIOS revision supported in the
751  *	same format.
752  */
753 
754 static int apm_driver_version(u_short *val)
755 {
756 	u32 eax;
757 	int err;
758 
759 	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
760 		return err;
761 	*val = eax;
762 	return APM_SUCCESS;
763 }
764 
765 /**
766  *	apm_get_event	-	get an APM event from the BIOS
767  *	@event: pointer to the event
768  *	@info: point to the event information
769  *
770  *	The APM BIOS provides a polled information for event
771  *	reporting. The BIOS expects to be polled at least every second
772  *	when events are pending. When a message is found the caller should
773  *	poll until no more messages are present.  However, this causes
774  *	problems on some laptops where a suspend event notification is
775  *	not cleared until it is acknowledged.
776  *
777  *	Additional information is returned in the info pointer, providing
778  *	that APM 1.2 is in use. If no messges are pending the value 0x80
779  *	is returned (No power management events pending).
780  */
781 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
782 {
783 	struct apm_bios_call call;
784 
785 	call.func = APM_FUNC_GET_EVENT;
786 	call.ebx = call.ecx = 0;
787 
788 	if (apm_bios_call(&call))
789 		return call.err;
790 
791 	*event = call.ebx;
792 	if (apm_info.connection_version < 0x0102)
793 		*info = ~0; /* indicate info not valid */
794 	else
795 		*info = call.ecx;
796 	return APM_SUCCESS;
797 }
798 
799 /**
800  *	set_power_state	-	set the power management state
801  *	@what: which items to transition
802  *	@state: state to transition to
803  *
804  *	Request an APM change of state for one or more system devices. The
805  *	processor state must be transitioned last of all. what holds the
806  *	class of device in the upper byte and the device number (0xFF for
807  *	all) for the object to be transitioned.
808  *
809  *	The state holds the state to transition to, which may in fact
810  *	be an acceptance of a BIOS requested state change.
811  */
812 
813 static int set_power_state(u_short what, u_short state)
814 {
815 	u32 eax;
816 	int err;
817 
818 	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
819 		return err;
820 	return APM_SUCCESS;
821 }
822 
823 /**
824  *	set_system_power_state - set system wide power state
825  *	@state: which state to enter
826  *
827  *	Transition the entire system into a new APM power state.
828  */
829 
830 static int set_system_power_state(u_short state)
831 {
832 	return set_power_state(APM_DEVICE_ALL, state);
833 }
834 
835 /**
836  *	apm_do_idle	-	perform power saving
837  *
838  *	This function notifies the BIOS that the processor is (in the view
839  *	of the OS) idle. It returns -1 in the event that the BIOS refuses
840  *	to handle the idle request. On a success the function returns 1
841  *	if the BIOS did clock slowing or 0 otherwise.
842  */
843 
844 static int apm_do_idle(void)
845 {
846 	u32 eax;
847 	u8 ret = 0;
848 	int idled = 0;
849 	int err = 0;
850 
851 	if (!need_resched()) {
852 		idled = 1;
853 		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
854 	}
855 
856 	if (!idled)
857 		return 0;
858 
859 	if (ret) {
860 		static unsigned long t;
861 
862 		/* This always fails on some SMP boards running UP kernels.
863 		 * Only report the failure the first 5 times.
864 		 */
865 		if (++t < 5) {
866 			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
867 			t = jiffies;
868 		}
869 		return -1;
870 	}
871 	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
872 	return clock_slowed;
873 }
874 
875 /**
876  *	apm_do_busy	-	inform the BIOS the CPU is busy
877  *
878  *	Request that the BIOS brings the CPU back to full performance.
879  */
880 
881 static void apm_do_busy(void)
882 {
883 	u32 dummy;
884 	int err;
885 
886 	if (clock_slowed || ALWAYS_CALL_BUSY) {
887 		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
888 		clock_slowed = 0;
889 	}
890 }
891 
892 /*
893  * If no process has really been interested in
894  * the CPU for some time, we want to call BIOS
895  * power management - we probably want
896  * to conserve power.
897  */
898 #define IDLE_CALC_LIMIT	(HZ * 100)
899 #define IDLE_LEAKY_MAX	16
900 
901 /**
902  * apm_cpu_idle		-	cpu idling for APM capable Linux
903  *
904  * This is the idling function the kernel executes when APM is available. It
905  * tries to do BIOS powermanagement based on the average system idle time.
906  * Furthermore it calls the system default idle routine.
907  */
908 
909 static int apm_cpu_idle(struct cpuidle_device *dev,
910 	struct cpuidle_driver *drv, int index)
911 {
912 	static int use_apm_idle; /* = 0 */
913 	static unsigned int last_jiffies; /* = 0 */
914 	static u64 last_stime; /* = 0 */
915 	u64 stime, utime;
916 
917 	int apm_idle_done = 0;
918 	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
919 	unsigned int bucket;
920 
921 recalc:
922 	task_cputime(current, &utime, &stime);
923 	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
924 		use_apm_idle = 0;
925 	} else if (jiffies_since_last_check > idle_period) {
926 		unsigned int idle_percentage;
927 
928 		idle_percentage = nsecs_to_jiffies(stime - last_stime);
929 		idle_percentage *= 100;
930 		idle_percentage /= jiffies_since_last_check;
931 		use_apm_idle = (idle_percentage > idle_threshold);
932 		if (apm_info.forbid_idle)
933 			use_apm_idle = 0;
934 	}
935 
936 	last_jiffies = jiffies;
937 	last_stime = stime;
938 
939 	bucket = IDLE_LEAKY_MAX;
940 
941 	while (!need_resched()) {
942 		if (use_apm_idle) {
943 			unsigned int t;
944 
945 			t = jiffies;
946 			switch (apm_do_idle()) {
947 			case 0:
948 				apm_idle_done = 1;
949 				if (t != jiffies) {
950 					if (bucket) {
951 						bucket = IDLE_LEAKY_MAX;
952 						continue;
953 					}
954 				} else if (bucket) {
955 					bucket--;
956 					continue;
957 				}
958 				break;
959 			case 1:
960 				apm_idle_done = 1;
961 				break;
962 			default: /* BIOS refused */
963 				break;
964 			}
965 		}
966 		default_idle();
967 		local_irq_disable();
968 		jiffies_since_last_check = jiffies - last_jiffies;
969 		if (jiffies_since_last_check > idle_period)
970 			goto recalc;
971 	}
972 
973 	if (apm_idle_done)
974 		apm_do_busy();
975 
976 	return index;
977 }
978 
979 /**
980  *	apm_power_off	-	ask the BIOS to power off
981  *
982  *	Handle the power off sequence. This is the one piece of code we
983  *	will execute even on SMP machines. In order to deal with BIOS
984  *	bugs we support real mode APM BIOS power off calls. We also make
985  *	the SMP call on CPU0 as some systems will only honour this call
986  *	on their first cpu.
987  */
988 
989 static void apm_power_off(void)
990 {
991 	/* Some bioses don't like being called from CPU != 0 */
992 	if (apm_info.realmode_power_off) {
993 		set_cpus_allowed_ptr(current, cpumask_of(0));
994 		machine_real_restart(MRR_APM);
995 	} else {
996 		(void)set_system_power_state(APM_STATE_OFF);
997 	}
998 }
999 
1000 #ifdef CONFIG_APM_DO_ENABLE
1001 
1002 /**
1003  *	apm_enable_power_management - enable BIOS APM power management
1004  *	@enable: enable yes/no
1005  *
1006  *	Enable or disable the APM BIOS power services.
1007  */
1008 
1009 static int apm_enable_power_management(int enable)
1010 {
1011 	u32 eax;
1012 	int err;
1013 
1014 	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1015 		return APM_NOT_ENGAGED;
1016 	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1017 				 enable, &eax, &err))
1018 		return err;
1019 	if (enable)
1020 		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1021 	else
1022 		apm_info.bios.flags |= APM_BIOS_DISABLED;
1023 	return APM_SUCCESS;
1024 }
1025 #endif
1026 
1027 /**
1028  *	apm_get_power_status	-	get current power state
1029  *	@status: returned status
1030  *	@bat: battery info
1031  *	@life: estimated life
1032  *
1033  *	Obtain the current power status from the APM BIOS. We return a
1034  *	status which gives the rough battery status, and current power
1035  *	source. The bat value returned give an estimate as a percentage
1036  *	of life and a status value for the battery. The estimated life
1037  *	if reported is a lifetime in secodnds/minutes at current powwer
1038  *	consumption.
1039  */
1040 
1041 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1042 {
1043 	struct apm_bios_call call;
1044 
1045 	call.func = APM_FUNC_GET_STATUS;
1046 	call.ebx = APM_DEVICE_ALL;
1047 	call.ecx = 0;
1048 
1049 	if (apm_info.get_power_status_broken)
1050 		return APM_32_UNSUPPORTED;
1051 	if (apm_bios_call(&call)) {
1052 		if (!call.err)
1053 			return APM_NO_ERROR;
1054 		return call.err;
1055 	}
1056 	*status = call.ebx;
1057 	*bat = call.ecx;
1058 	if (apm_info.get_power_status_swabinminutes) {
1059 		*life = swab16((u16)call.edx);
1060 		*life |= 0x8000;
1061 	} else
1062 		*life = call.edx;
1063 	return APM_SUCCESS;
1064 }
1065 
1066 #if 0
1067 static int apm_get_battery_status(u_short which, u_short *status,
1068 				  u_short *bat, u_short *life, u_short *nbat)
1069 {
1070 	u32 eax;
1071 	u32 ebx;
1072 	u32 ecx;
1073 	u32 edx;
1074 	u32 esi;
1075 
1076 	if (apm_info.connection_version < 0x0102) {
1077 		/* pretend we only have one battery. */
1078 		if (which != 1)
1079 			return APM_BAD_DEVICE;
1080 		*nbat = 1;
1081 		return apm_get_power_status(status, bat, life);
1082 	}
1083 
1084 	if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1085 			  &ebx, &ecx, &edx, &esi))
1086 		return (eax >> 8) & 0xff;
1087 	*status = ebx;
1088 	*bat = ecx;
1089 	*life = edx;
1090 	*nbat = esi;
1091 	return APM_SUCCESS;
1092 }
1093 #endif
1094 
1095 /**
1096  *	apm_engage_power_management	-	enable PM on a device
1097  *	@device: identity of device
1098  *	@enable: on/off
1099  *
1100  *	Activate or deactivate power management on either a specific device
1101  *	or the entire system (%APM_DEVICE_ALL).
1102  */
1103 
1104 static int apm_engage_power_management(u_short device, int enable)
1105 {
1106 	u32 eax;
1107 	int err;
1108 
1109 	if ((enable == 0) && (device == APM_DEVICE_ALL)
1110 	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1111 		return APM_DISABLED;
1112 	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1113 				 &eax, &err))
1114 		return err;
1115 	if (device == APM_DEVICE_ALL) {
1116 		if (enable)
1117 			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1118 		else
1119 			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1120 	}
1121 	return APM_SUCCESS;
1122 }
1123 
1124 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1125 
1126 /**
1127  *	apm_console_blank	-	blank the display
1128  *	@blank: on/off
1129  *
1130  *	Attempt to blank the console, firstly by blanking just video device
1131  *	zero, and if that fails (some BIOSes don't support it) then it blanks
1132  *	all video devices. Typically the BIOS will do laptop backlight and
1133  *	monitor powerdown for us.
1134  */
1135 
1136 static int apm_console_blank(int blank)
1137 {
1138 	int error = APM_NOT_ENGAGED; /* silence gcc */
1139 	int i;
1140 	u_short state;
1141 	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1142 
1143 	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1144 
1145 	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1146 		error = set_power_state(dev[i], state);
1147 
1148 		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1149 			return 1;
1150 
1151 		if (error == APM_NOT_ENGAGED)
1152 			break;
1153 	}
1154 
1155 	if (error == APM_NOT_ENGAGED) {
1156 		static int tried;
1157 		int eng_error;
1158 		if (tried++ == 0) {
1159 			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1160 			if (eng_error) {
1161 				apm_error("set display", error);
1162 				apm_error("engage interface", eng_error);
1163 				return 0;
1164 			} else
1165 				return apm_console_blank(blank);
1166 		}
1167 	}
1168 	apm_error("set display", error);
1169 	return 0;
1170 }
1171 #endif
1172 
1173 static int queue_empty(struct apm_user *as)
1174 {
1175 	return as->event_head == as->event_tail;
1176 }
1177 
1178 static apm_event_t get_queued_event(struct apm_user *as)
1179 {
1180 	if (++as->event_tail >= APM_MAX_EVENTS)
1181 		as->event_tail = 0;
1182 	return as->events[as->event_tail];
1183 }
1184 
1185 static void queue_event(apm_event_t event, struct apm_user *sender)
1186 {
1187 	struct apm_user *as;
1188 
1189 	spin_lock(&user_list_lock);
1190 	if (user_list == NULL)
1191 		goto out;
1192 	for (as = user_list; as != NULL; as = as->next) {
1193 		if ((as == sender) || (!as->reader))
1194 			continue;
1195 		if (++as->event_head >= APM_MAX_EVENTS)
1196 			as->event_head = 0;
1197 
1198 		if (as->event_head == as->event_tail) {
1199 			static int notified;
1200 
1201 			if (notified++ == 0)
1202 				pr_err("an event queue overflowed\n");
1203 			if (++as->event_tail >= APM_MAX_EVENTS)
1204 				as->event_tail = 0;
1205 		}
1206 		as->events[as->event_head] = event;
1207 		if (!as->suser || !as->writer)
1208 			continue;
1209 		switch (event) {
1210 		case APM_SYS_SUSPEND:
1211 		case APM_USER_SUSPEND:
1212 			as->suspends_pending++;
1213 			suspends_pending++;
1214 			break;
1215 
1216 		case APM_SYS_STANDBY:
1217 		case APM_USER_STANDBY:
1218 			as->standbys_pending++;
1219 			standbys_pending++;
1220 			break;
1221 		}
1222 	}
1223 	wake_up_interruptible(&apm_waitqueue);
1224 out:
1225 	spin_unlock(&user_list_lock);
1226 }
1227 
1228 static void reinit_timer(void)
1229 {
1230 #ifdef INIT_TIMER_AFTER_SUSPEND
1231 	unsigned long flags;
1232 
1233 	raw_spin_lock_irqsave(&i8253_lock, flags);
1234 	/* set the clock to HZ */
1235 	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1236 	udelay(10);
1237 	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1238 	udelay(10);
1239 	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1240 	udelay(10);
1241 	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1242 #endif
1243 }
1244 
1245 static int suspend(int vetoable)
1246 {
1247 	int err;
1248 	struct apm_user	*as;
1249 
1250 	dpm_suspend_start(PMSG_SUSPEND);
1251 	dpm_suspend_end(PMSG_SUSPEND);
1252 
1253 	local_irq_disable();
1254 	syscore_suspend();
1255 
1256 	local_irq_enable();
1257 
1258 	save_processor_state();
1259 	err = set_system_power_state(APM_STATE_SUSPEND);
1260 	ignore_normal_resume = 1;
1261 	restore_processor_state();
1262 
1263 	local_irq_disable();
1264 	reinit_timer();
1265 
1266 	if (err == APM_NO_ERROR)
1267 		err = APM_SUCCESS;
1268 	if (err != APM_SUCCESS)
1269 		apm_error("suspend", err);
1270 	err = (err == APM_SUCCESS) ? 0 : -EIO;
1271 
1272 	syscore_resume();
1273 	local_irq_enable();
1274 
1275 	dpm_resume_start(PMSG_RESUME);
1276 	dpm_resume_end(PMSG_RESUME);
1277 
1278 	queue_event(APM_NORMAL_RESUME, NULL);
1279 	spin_lock(&user_list_lock);
1280 	for (as = user_list; as != NULL; as = as->next) {
1281 		as->suspend_wait = 0;
1282 		as->suspend_result = err;
1283 	}
1284 	spin_unlock(&user_list_lock);
1285 	wake_up_interruptible(&apm_suspend_waitqueue);
1286 	return err;
1287 }
1288 
1289 static void standby(void)
1290 {
1291 	int err;
1292 
1293 	dpm_suspend_end(PMSG_SUSPEND);
1294 
1295 	local_irq_disable();
1296 	syscore_suspend();
1297 	local_irq_enable();
1298 
1299 	err = set_system_power_state(APM_STATE_STANDBY);
1300 	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1301 		apm_error("standby", err);
1302 
1303 	local_irq_disable();
1304 	syscore_resume();
1305 	local_irq_enable();
1306 
1307 	dpm_resume_start(PMSG_RESUME);
1308 }
1309 
1310 static apm_event_t get_event(void)
1311 {
1312 	int error;
1313 	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1314 	apm_eventinfo_t	info;
1315 
1316 	static int notified;
1317 
1318 	/* we don't use the eventinfo */
1319 	error = apm_get_event(&event, &info);
1320 	if (error == APM_SUCCESS)
1321 		return event;
1322 
1323 	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1324 		apm_error("get_event", error);
1325 
1326 	return 0;
1327 }
1328 
1329 static void check_events(void)
1330 {
1331 	apm_event_t event;
1332 	static unsigned long last_resume;
1333 	static int ignore_bounce;
1334 
1335 	while ((event = get_event()) != 0) {
1336 		if (debug) {
1337 			if (event <= NR_APM_EVENT_NAME)
1338 				printk(KERN_DEBUG "apm: received %s notify\n",
1339 				       apm_event_name[event - 1]);
1340 			else
1341 				printk(KERN_DEBUG "apm: received unknown "
1342 				       "event 0x%02x\n", event);
1343 		}
1344 		if (ignore_bounce
1345 		    && (time_after(jiffies, last_resume + bounce_interval)))
1346 			ignore_bounce = 0;
1347 
1348 		switch (event) {
1349 		case APM_SYS_STANDBY:
1350 		case APM_USER_STANDBY:
1351 			queue_event(event, NULL);
1352 			if (standbys_pending <= 0)
1353 				standby();
1354 			break;
1355 
1356 		case APM_USER_SUSPEND:
1357 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1358 			if (apm_info.connection_version > 0x100)
1359 				set_system_power_state(APM_STATE_REJECT);
1360 			break;
1361 #endif
1362 		case APM_SYS_SUSPEND:
1363 			if (ignore_bounce) {
1364 				if (apm_info.connection_version > 0x100)
1365 					set_system_power_state(APM_STATE_REJECT);
1366 				break;
1367 			}
1368 			/*
1369 			 * If we are already processing a SUSPEND,
1370 			 * then further SUSPEND events from the BIOS
1371 			 * will be ignored.  We also return here to
1372 			 * cope with the fact that the Thinkpads keep
1373 			 * sending a SUSPEND event until something else
1374 			 * happens!
1375 			 */
1376 			if (ignore_sys_suspend)
1377 				return;
1378 			ignore_sys_suspend = 1;
1379 			queue_event(event, NULL);
1380 			if (suspends_pending <= 0)
1381 				(void) suspend(1);
1382 			break;
1383 
1384 		case APM_NORMAL_RESUME:
1385 		case APM_CRITICAL_RESUME:
1386 		case APM_STANDBY_RESUME:
1387 			ignore_sys_suspend = 0;
1388 			last_resume = jiffies;
1389 			ignore_bounce = 1;
1390 			if ((event != APM_NORMAL_RESUME)
1391 			    || (ignore_normal_resume == 0)) {
1392 				dpm_resume_end(PMSG_RESUME);
1393 				queue_event(event, NULL);
1394 			}
1395 			ignore_normal_resume = 0;
1396 			break;
1397 
1398 		case APM_CAPABILITY_CHANGE:
1399 		case APM_LOW_BATTERY:
1400 		case APM_POWER_STATUS_CHANGE:
1401 			queue_event(event, NULL);
1402 			/* If needed, notify drivers here */
1403 			break;
1404 
1405 		case APM_UPDATE_TIME:
1406 			break;
1407 
1408 		case APM_CRITICAL_SUSPEND:
1409 			/*
1410 			 * We are not allowed to reject a critical suspend.
1411 			 */
1412 			(void)suspend(0);
1413 			break;
1414 		}
1415 	}
1416 }
1417 
1418 static void apm_event_handler(void)
1419 {
1420 	static int pending_count = 4;
1421 	int err;
1422 
1423 	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1424 		if ((apm_info.connection_version > 0x100) &&
1425 		    (pending_count-- <= 0)) {
1426 			pending_count = 4;
1427 			if (debug)
1428 				printk(KERN_DEBUG "apm: setting state busy\n");
1429 			err = set_system_power_state(APM_STATE_BUSY);
1430 			if (err)
1431 				apm_error("busy", err);
1432 		}
1433 	} else
1434 		pending_count = 4;
1435 	check_events();
1436 }
1437 
1438 /*
1439  * This is the APM thread main loop.
1440  */
1441 
1442 static void apm_mainloop(void)
1443 {
1444 	DECLARE_WAITQUEUE(wait, current);
1445 
1446 	add_wait_queue(&apm_waitqueue, &wait);
1447 	set_current_state(TASK_INTERRUPTIBLE);
1448 	for (;;) {
1449 		schedule_timeout(APM_CHECK_TIMEOUT);
1450 		if (kthread_should_stop())
1451 			break;
1452 		/*
1453 		 * Ok, check all events, check for idle (and mark us sleeping
1454 		 * so as not to count towards the load average)..
1455 		 */
1456 		set_current_state(TASK_INTERRUPTIBLE);
1457 		apm_event_handler();
1458 	}
1459 	remove_wait_queue(&apm_waitqueue, &wait);
1460 }
1461 
1462 static int check_apm_user(struct apm_user *as, const char *func)
1463 {
1464 	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1465 		pr_err("%s passed bad filp\n", func);
1466 		return 1;
1467 	}
1468 	return 0;
1469 }
1470 
1471 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1472 {
1473 	struct apm_user *as;
1474 	int i;
1475 	apm_event_t event;
1476 
1477 	as = fp->private_data;
1478 	if (check_apm_user(as, "read"))
1479 		return -EIO;
1480 	if ((int)count < sizeof(apm_event_t))
1481 		return -EINVAL;
1482 	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1483 		return -EAGAIN;
1484 	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1485 	i = count;
1486 	while ((i >= sizeof(event)) && !queue_empty(as)) {
1487 		event = get_queued_event(as);
1488 		if (copy_to_user(buf, &event, sizeof(event))) {
1489 			if (i < count)
1490 				break;
1491 			return -EFAULT;
1492 		}
1493 		switch (event) {
1494 		case APM_SYS_SUSPEND:
1495 		case APM_USER_SUSPEND:
1496 			as->suspends_read++;
1497 			break;
1498 
1499 		case APM_SYS_STANDBY:
1500 		case APM_USER_STANDBY:
1501 			as->standbys_read++;
1502 			break;
1503 		}
1504 		buf += sizeof(event);
1505 		i -= sizeof(event);
1506 	}
1507 	if (i < count)
1508 		return count - i;
1509 	if (signal_pending(current))
1510 		return -ERESTARTSYS;
1511 	return 0;
1512 }
1513 
1514 static __poll_t do_poll(struct file *fp, poll_table *wait)
1515 {
1516 	struct apm_user *as;
1517 
1518 	as = fp->private_data;
1519 	if (check_apm_user(as, "poll"))
1520 		return 0;
1521 	poll_wait(fp, &apm_waitqueue, wait);
1522 	if (!queue_empty(as))
1523 		return EPOLLIN | EPOLLRDNORM;
1524 	return 0;
1525 }
1526 
1527 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1528 {
1529 	struct apm_user *as;
1530 	int ret;
1531 
1532 	as = filp->private_data;
1533 	if (check_apm_user(as, "ioctl"))
1534 		return -EIO;
1535 	if (!as->suser || !as->writer)
1536 		return -EPERM;
1537 	switch (cmd) {
1538 	case APM_IOC_STANDBY:
1539 		mutex_lock(&apm_mutex);
1540 		if (as->standbys_read > 0) {
1541 			as->standbys_read--;
1542 			as->standbys_pending--;
1543 			standbys_pending--;
1544 		} else
1545 			queue_event(APM_USER_STANDBY, as);
1546 		if (standbys_pending <= 0)
1547 			standby();
1548 		mutex_unlock(&apm_mutex);
1549 		break;
1550 	case APM_IOC_SUSPEND:
1551 		mutex_lock(&apm_mutex);
1552 		if (as->suspends_read > 0) {
1553 			as->suspends_read--;
1554 			as->suspends_pending--;
1555 			suspends_pending--;
1556 		} else
1557 			queue_event(APM_USER_SUSPEND, as);
1558 		if (suspends_pending <= 0) {
1559 			ret = suspend(1);
1560 			mutex_unlock(&apm_mutex);
1561 		} else {
1562 			as->suspend_wait = 1;
1563 			mutex_unlock(&apm_mutex);
1564 			wait_event_interruptible(apm_suspend_waitqueue,
1565 					as->suspend_wait == 0);
1566 			ret = as->suspend_result;
1567 		}
1568 		return ret;
1569 	default:
1570 		return -ENOTTY;
1571 	}
1572 	return 0;
1573 }
1574 
1575 static int do_release(struct inode *inode, struct file *filp)
1576 {
1577 	struct apm_user *as;
1578 
1579 	as = filp->private_data;
1580 	if (check_apm_user(as, "release"))
1581 		return 0;
1582 	filp->private_data = NULL;
1583 	if (as->standbys_pending > 0) {
1584 		standbys_pending -= as->standbys_pending;
1585 		if (standbys_pending <= 0)
1586 			standby();
1587 	}
1588 	if (as->suspends_pending > 0) {
1589 		suspends_pending -= as->suspends_pending;
1590 		if (suspends_pending <= 0)
1591 			(void) suspend(1);
1592 	}
1593 	spin_lock(&user_list_lock);
1594 	if (user_list == as)
1595 		user_list = as->next;
1596 	else {
1597 		struct apm_user *as1;
1598 
1599 		for (as1 = user_list;
1600 		     (as1 != NULL) && (as1->next != as);
1601 		     as1 = as1->next)
1602 			;
1603 		if (as1 == NULL)
1604 			pr_err("filp not in user list\n");
1605 		else
1606 			as1->next = as->next;
1607 	}
1608 	spin_unlock(&user_list_lock);
1609 	kfree(as);
1610 	return 0;
1611 }
1612 
1613 static int do_open(struct inode *inode, struct file *filp)
1614 {
1615 	struct apm_user *as;
1616 
1617 	as = kmalloc(sizeof(*as), GFP_KERNEL);
1618 	if (as == NULL)
1619 		return -ENOMEM;
1620 
1621 	as->magic = APM_BIOS_MAGIC;
1622 	as->event_tail = as->event_head = 0;
1623 	as->suspends_pending = as->standbys_pending = 0;
1624 	as->suspends_read = as->standbys_read = 0;
1625 	/*
1626 	 * XXX - this is a tiny bit broken, when we consider BSD
1627 	 * process accounting. If the device is opened by root, we
1628 	 * instantly flag that we used superuser privs. Who knows,
1629 	 * we might close the device immediately without doing a
1630 	 * privileged operation -- cevans
1631 	 */
1632 	as->suser = capable(CAP_SYS_ADMIN);
1633 	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1634 	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1635 	spin_lock(&user_list_lock);
1636 	as->next = user_list;
1637 	user_list = as;
1638 	spin_unlock(&user_list_lock);
1639 	filp->private_data = as;
1640 	return 0;
1641 }
1642 
1643 #ifdef CONFIG_PROC_FS
1644 static int proc_apm_show(struct seq_file *m, void *v)
1645 {
1646 	unsigned short	bx;
1647 	unsigned short	cx;
1648 	unsigned short	dx;
1649 	int		error;
1650 	unsigned short  ac_line_status = 0xff;
1651 	unsigned short  battery_status = 0xff;
1652 	unsigned short  battery_flag   = 0xff;
1653 	int		percentage     = -1;
1654 	int             time_units     = -1;
1655 	char            *units         = "?";
1656 
1657 	if ((num_online_cpus() == 1) &&
1658 	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1659 		ac_line_status = (bx >> 8) & 0xff;
1660 		battery_status = bx & 0xff;
1661 		if ((cx & 0xff) != 0xff)
1662 			percentage = cx & 0xff;
1663 
1664 		if (apm_info.connection_version > 0x100) {
1665 			battery_flag = (cx >> 8) & 0xff;
1666 			if (dx != 0xffff) {
1667 				units = (dx & 0x8000) ? "min" : "sec";
1668 				time_units = dx & 0x7fff;
1669 			}
1670 		}
1671 	}
1672 	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1673 	   from the Get Power Status (0x0a) call unless otherwise noted.
1674 
1675 	   0) Linux driver version (this will change if format changes)
1676 	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1677 	   2) APM flags from APM Installation Check (0x00):
1678 	      bit 0: APM_16_BIT_SUPPORT
1679 	      bit 1: APM_32_BIT_SUPPORT
1680 	      bit 2: APM_IDLE_SLOWS_CLOCK
1681 	      bit 3: APM_BIOS_DISABLED
1682 	      bit 4: APM_BIOS_DISENGAGED
1683 	   3) AC line status
1684 	      0x00: Off-line
1685 	      0x01: On-line
1686 	      0x02: On backup power (BIOS >= 1.1 only)
1687 	      0xff: Unknown
1688 	   4) Battery status
1689 	      0x00: High
1690 	      0x01: Low
1691 	      0x02: Critical
1692 	      0x03: Charging
1693 	      0x04: Selected battery not present (BIOS >= 1.2 only)
1694 	      0xff: Unknown
1695 	   5) Battery flag
1696 	      bit 0: High
1697 	      bit 1: Low
1698 	      bit 2: Critical
1699 	      bit 3: Charging
1700 	      bit 7: No system battery
1701 	      0xff: Unknown
1702 	   6) Remaining battery life (percentage of charge):
1703 	      0-100: valid
1704 	      -1: Unknown
1705 	   7) Remaining battery life (time units):
1706 	      Number of remaining minutes or seconds
1707 	      -1: Unknown
1708 	   8) min = minutes; sec = seconds */
1709 
1710 	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1711 		   driver_version,
1712 		   (apm_info.bios.version >> 8) & 0xff,
1713 		   apm_info.bios.version & 0xff,
1714 		   apm_info.bios.flags,
1715 		   ac_line_status,
1716 		   battery_status,
1717 		   battery_flag,
1718 		   percentage,
1719 		   time_units,
1720 		   units);
1721 	return 0;
1722 }
1723 #endif
1724 
1725 static int apm(void *unused)
1726 {
1727 	unsigned short	bx;
1728 	unsigned short	cx;
1729 	unsigned short	dx;
1730 	int		error;
1731 	char 		*power_stat;
1732 	char 		*bat_stat;
1733 
1734 	/* 2002/08/01 - WT
1735 	 * This is to avoid random crashes at boot time during initialization
1736 	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1737 	 * Some bioses don't like being called from CPU != 0.
1738 	 * Method suggested by Ingo Molnar.
1739 	 */
1740 	set_cpus_allowed_ptr(current, cpumask_of(0));
1741 	BUG_ON(smp_processor_id() != 0);
1742 
1743 	if (apm_info.connection_version == 0) {
1744 		apm_info.connection_version = apm_info.bios.version;
1745 		if (apm_info.connection_version > 0x100) {
1746 			/*
1747 			 * We only support BIOSs up to version 1.2
1748 			 */
1749 			if (apm_info.connection_version > 0x0102)
1750 				apm_info.connection_version = 0x0102;
1751 			error = apm_driver_version(&apm_info.connection_version);
1752 			if (error != APM_SUCCESS) {
1753 				apm_error("driver version", error);
1754 				/* Fall back to an APM 1.0 connection. */
1755 				apm_info.connection_version = 0x100;
1756 			}
1757 		}
1758 	}
1759 
1760 	if (debug)
1761 		printk(KERN_INFO "apm: Connection version %d.%d\n",
1762 			(apm_info.connection_version >> 8) & 0xff,
1763 			apm_info.connection_version & 0xff);
1764 
1765 #ifdef CONFIG_APM_DO_ENABLE
1766 	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1767 		/*
1768 		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1769 		 * is booted with PM disabled but not in the docking station.
1770 		 * Unfortunate ...
1771 		 */
1772 		error = apm_enable_power_management(1);
1773 		if (error) {
1774 			apm_error("enable power management", error);
1775 			return -1;
1776 		}
1777 	}
1778 #endif
1779 
1780 	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1781 	    && (apm_info.connection_version > 0x0100)) {
1782 		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1783 		if (error) {
1784 			apm_error("engage power management", error);
1785 			return -1;
1786 		}
1787 	}
1788 
1789 	if (debug && (num_online_cpus() == 1 || smp)) {
1790 		error = apm_get_power_status(&bx, &cx, &dx);
1791 		if (error)
1792 			printk(KERN_INFO "apm: power status not available\n");
1793 		else {
1794 			switch ((bx >> 8) & 0xff) {
1795 			case 0:
1796 				power_stat = "off line";
1797 				break;
1798 			case 1:
1799 				power_stat = "on line";
1800 				break;
1801 			case 2:
1802 				power_stat = "on backup power";
1803 				break;
1804 			default:
1805 				power_stat = "unknown";
1806 				break;
1807 			}
1808 			switch (bx & 0xff) {
1809 			case 0:
1810 				bat_stat = "high";
1811 				break;
1812 			case 1:
1813 				bat_stat = "low";
1814 				break;
1815 			case 2:
1816 				bat_stat = "critical";
1817 				break;
1818 			case 3:
1819 				bat_stat = "charging";
1820 				break;
1821 			default:
1822 				bat_stat = "unknown";
1823 				break;
1824 			}
1825 			printk(KERN_INFO
1826 			       "apm: AC %s, battery status %s, battery life ",
1827 			       power_stat, bat_stat);
1828 			if ((cx & 0xff) == 0xff)
1829 				printk("unknown\n");
1830 			else
1831 				printk("%d%%\n", cx & 0xff);
1832 			if (apm_info.connection_version > 0x100) {
1833 				printk(KERN_INFO
1834 				       "apm: battery flag 0x%02x, battery life ",
1835 				       (cx >> 8) & 0xff);
1836 				if (dx == 0xffff)
1837 					printk("unknown\n");
1838 				else
1839 					printk("%d %s\n", dx & 0x7fff,
1840 					       (dx & 0x8000) ?
1841 					       "minutes" : "seconds");
1842 			}
1843 		}
1844 	}
1845 
1846 	/* Install our power off handler.. */
1847 	if (power_off)
1848 		pm_power_off = apm_power_off;
1849 
1850 	if (num_online_cpus() == 1 || smp) {
1851 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1852 		console_blank_hook = apm_console_blank;
1853 #endif
1854 		apm_mainloop();
1855 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1856 		console_blank_hook = NULL;
1857 #endif
1858 	}
1859 
1860 	return 0;
1861 }
1862 
1863 #ifndef MODULE
1864 static int __init apm_setup(char *str)
1865 {
1866 	int invert;
1867 
1868 	while ((str != NULL) && (*str != '\0')) {
1869 		if (strncmp(str, "off", 3) == 0)
1870 			apm_disabled = 1;
1871 		if (strncmp(str, "on", 2) == 0)
1872 			apm_disabled = 0;
1873 		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1874 		    (strncmp(str, "bounce_interval=", 16) == 0))
1875 			bounce_interval = simple_strtol(str + 16, NULL, 0);
1876 		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1877 		    (strncmp(str, "idle_threshold=", 15) == 0))
1878 			idle_threshold = simple_strtol(str + 15, NULL, 0);
1879 		if ((strncmp(str, "idle-period=", 12) == 0) ||
1880 		    (strncmp(str, "idle_period=", 12) == 0))
1881 			idle_period = simple_strtol(str + 12, NULL, 0);
1882 		invert = (strncmp(str, "no-", 3) == 0) ||
1883 			(strncmp(str, "no_", 3) == 0);
1884 		if (invert)
1885 			str += 3;
1886 		if (strncmp(str, "debug", 5) == 0)
1887 			debug = !invert;
1888 		if ((strncmp(str, "power-off", 9) == 0) ||
1889 		    (strncmp(str, "power_off", 9) == 0))
1890 			power_off = !invert;
1891 		if (strncmp(str, "smp", 3) == 0) {
1892 			smp = !invert;
1893 			idle_threshold = 100;
1894 		}
1895 		if ((strncmp(str, "allow-ints", 10) == 0) ||
1896 		    (strncmp(str, "allow_ints", 10) == 0))
1897 			apm_info.allow_ints = !invert;
1898 		if ((strncmp(str, "broken-psr", 10) == 0) ||
1899 		    (strncmp(str, "broken_psr", 10) == 0))
1900 			apm_info.get_power_status_broken = !invert;
1901 		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1902 		    (strncmp(str, "realmode_power_off", 18) == 0))
1903 			apm_info.realmode_power_off = !invert;
1904 		str = strchr(str, ',');
1905 		if (str != NULL)
1906 			str += strspn(str, ", \t");
1907 	}
1908 	return 1;
1909 }
1910 
1911 __setup("apm=", apm_setup);
1912 #endif
1913 
1914 static const struct file_operations apm_bios_fops = {
1915 	.owner		= THIS_MODULE,
1916 	.read		= do_read,
1917 	.poll		= do_poll,
1918 	.unlocked_ioctl	= do_ioctl,
1919 	.open		= do_open,
1920 	.release	= do_release,
1921 	.llseek		= noop_llseek,
1922 };
1923 
1924 static struct miscdevice apm_device = {
1925 	APM_MINOR_DEV,
1926 	"apm_bios",
1927 	&apm_bios_fops
1928 };
1929 
1930 
1931 /* Simple "print if true" callback */
1932 static int __init print_if_true(const struct dmi_system_id *d)
1933 {
1934 	printk("%s\n", d->ident);
1935 	return 0;
1936 }
1937 
1938 /*
1939  * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1940  * disabled before the suspend. Linux used to get terribly confused by that.
1941  */
1942 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1943 {
1944 	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1945 	       "workaround hopefully not needed.\n", d->ident);
1946 	return 0;
1947 }
1948 
1949 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1950 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1951 {
1952 	if (apm_info.realmode_power_off == 0) {
1953 		apm_info.realmode_power_off = 1;
1954 		printk(KERN_INFO "%s bios detected. "
1955 		       "Using realmode poweroff only.\n", d->ident);
1956 	}
1957 	return 0;
1958 }
1959 
1960 /* Some laptops require interrupts to be enabled during APM calls */
1961 static int __init set_apm_ints(const struct dmi_system_id *d)
1962 {
1963 	if (apm_info.allow_ints == 0) {
1964 		apm_info.allow_ints = 1;
1965 		printk(KERN_INFO "%s machine detected. "
1966 		       "Enabling interrupts during APM calls.\n", d->ident);
1967 	}
1968 	return 0;
1969 }
1970 
1971 /* Some APM bioses corrupt memory or just plain do not work */
1972 static int __init apm_is_horked(const struct dmi_system_id *d)
1973 {
1974 	if (apm_info.disabled == 0) {
1975 		apm_info.disabled = 1;
1976 		printk(KERN_INFO "%s machine detected. "
1977 		       "Disabling APM.\n", d->ident);
1978 	}
1979 	return 0;
1980 }
1981 
1982 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1983 {
1984 	if (apm_info.disabled == 0) {
1985 		apm_info.disabled = 1;
1986 		printk(KERN_INFO "%s machine detected. "
1987 		       "Disabling APM.\n", d->ident);
1988 		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1989 		printk(KERN_INFO "download from support.intel.com\n");
1990 	}
1991 	return 0;
1992 }
1993 
1994 /* Some APM bioses hang on APM idle calls */
1995 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1996 {
1997 	if (apm_info.forbid_idle == 0) {
1998 		apm_info.forbid_idle = 1;
1999 		printk(KERN_INFO "%s machine detected. "
2000 		       "Disabling APM idle calls.\n", d->ident);
2001 	}
2002 	return 0;
2003 }
2004 
2005 /*
2006  *  Check for clue free BIOS implementations who use
2007  *  the following QA technique
2008  *
2009  *      [ Write BIOS Code ]<------
2010  *               |                ^
2011  *      < Does it Compile >----N--
2012  *               |Y               ^
2013  *	< Does it Boot Win98 >-N--
2014  *               |Y
2015  *           [Ship It]
2016  *
2017  *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
2018  *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
2019  */
2020 static int __init broken_apm_power(const struct dmi_system_id *d)
2021 {
2022 	apm_info.get_power_status_broken = 1;
2023 	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2024 	       "disabling power status reporting.\n");
2025 	return 0;
2026 }
2027 
2028 /*
2029  * This bios swaps the APM minute reporting bytes over (Many sony laptops
2030  * have this problem).
2031  */
2032 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2033 {
2034 	apm_info.get_power_status_swabinminutes = 1;
2035 	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2036 	       "in minutes and wrong byte order.\n");
2037 	return 0;
2038 }
2039 
2040 static const struct dmi_system_id apm_dmi_table[] __initconst = {
2041 	{
2042 		print_if_true,
2043 		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2044 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2045 			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2046 	},
2047 	{	/* Handle problems with APM on the C600 */
2048 		broken_ps2_resume, "Dell Latitude C600",
2049 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2050 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2051 	},
2052 	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2053 		set_apm_ints, "Dell Latitude",
2054 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2055 			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2056 	},
2057 	{	/* APM crashes */
2058 		apm_is_horked, "Dell Inspiron 2500",
2059 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2060 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2061 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2062 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2063 	},
2064 	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2065 		set_apm_ints, "Dell Inspiron", {
2066 			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2067 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2068 	},
2069 	{	/* Handle problems with APM on Inspiron 5000e */
2070 		broken_apm_power, "Dell Inspiron 5000e",
2071 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2072 			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2073 			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2074 	},
2075 	{	/* Handle problems with APM on Inspiron 2500 */
2076 		broken_apm_power, "Dell Inspiron 2500",
2077 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2078 			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2079 			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2080 	},
2081 	{	/* APM crashes */
2082 		apm_is_horked, "Dell Dimension 4100",
2083 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2084 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2085 			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2086 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2087 	},
2088 	{	/* Allow interrupts during suspend on Compaq Laptops*/
2089 		set_apm_ints, "Compaq 12XL125",
2090 		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2091 			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2092 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2093 			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2094 	},
2095 	{	/* Allow interrupts during APM or the clock goes slow */
2096 		set_apm_ints, "ASUSTeK",
2097 		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2098 			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2099 	},
2100 	{	/* APM blows on shutdown */
2101 		apm_is_horked, "ABIT KX7-333[R]",
2102 		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2103 			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2104 	},
2105 	{	/* APM crashes */
2106 		apm_is_horked, "Trigem Delhi3",
2107 		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2108 			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2109 	},
2110 	{	/* APM crashes */
2111 		apm_is_horked, "Fujitsu-Siemens",
2112 		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2113 			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2114 	},
2115 	{	/* APM crashes */
2116 		apm_is_horked_d850md, "Intel D850MD",
2117 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2118 			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2119 	},
2120 	{	/* APM crashes */
2121 		apm_is_horked, "Intel D810EMO",
2122 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2123 			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2124 	},
2125 	{	/* APM crashes */
2126 		apm_is_horked, "Dell XPS-Z",
2127 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2128 			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2129 			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2130 	},
2131 	{	/* APM crashes */
2132 		apm_is_horked, "Sharp PC-PJ/AX",
2133 		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2134 			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2135 			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2136 			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2137 	},
2138 	{	/* APM crashes */
2139 		apm_is_horked, "Dell Inspiron 2500",
2140 		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2141 			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2142 			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2143 			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2144 	},
2145 	{	/* APM idle hangs */
2146 		apm_likes_to_melt, "Jabil AMD",
2147 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2148 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2149 	},
2150 	{	/* APM idle hangs */
2151 		apm_likes_to_melt, "AMI Bios",
2152 		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2153 			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2154 	},
2155 	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2156 		swab_apm_power_in_minutes, "Sony VAIO",
2157 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2158 			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2159 			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2160 	},
2161 	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2162 		swab_apm_power_in_minutes, "Sony VAIO",
2163 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2164 			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2165 			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2166 	},
2167 	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2168 		swab_apm_power_in_minutes, "Sony VAIO",
2169 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2170 			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2171 			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2172 	},
2173 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2174 		swab_apm_power_in_minutes, "Sony VAIO",
2175 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2176 			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2177 			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2178 	},
2179 	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2180 		swab_apm_power_in_minutes, "Sony VAIO",
2181 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2182 			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2183 			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2184 	},
2185 	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2186 		swab_apm_power_in_minutes, "Sony VAIO",
2187 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2188 			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2189 			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2190 	},
2191 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2192 		swab_apm_power_in_minutes, "Sony VAIO",
2193 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2194 			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2195 			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2196 	},
2197 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2198 		swab_apm_power_in_minutes, "Sony VAIO",
2199 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2200 			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2201 			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2202 	},
2203 	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2204 		swab_apm_power_in_minutes, "Sony VAIO",
2205 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2206 			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2207 			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2208 	},
2209 	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2210 		swab_apm_power_in_minutes, "Sony VAIO",
2211 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2212 			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2213 			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2214 	},
2215 
2216 	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2217 		swab_apm_power_in_minutes, "Sony VAIO",
2218 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2219 			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2220 			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2221 	},
2222 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2223 		swab_apm_power_in_minutes, "Sony VAIO",
2224 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2225 			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2226 			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2227 	},
2228 	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2229 		swab_apm_power_in_minutes, "Sony VAIO",
2230 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2231 			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2232 			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2233 	},
2234 	{	/* broken PM poweroff bios */
2235 		set_realmode_power_off, "Award Software v4.60 PGMA",
2236 		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2237 			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2238 			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2239 	},
2240 
2241 	/* Generic per vendor APM settings  */
2242 
2243 	{	/* Allow interrupts during suspend on IBM laptops */
2244 		set_apm_ints, "IBM",
2245 		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2246 	},
2247 
2248 	{ }
2249 };
2250 
2251 /*
2252  * Just start the APM thread. We do NOT want to do APM BIOS
2253  * calls from anything but the APM thread, if for no other reason
2254  * than the fact that we don't trust the APM BIOS. This way,
2255  * most common APM BIOS problems that lead to protection errors
2256  * etc will have at least some level of being contained...
2257  *
2258  * In short, if something bad happens, at least we have a choice
2259  * of just killing the apm thread..
2260  */
2261 static int __init apm_init(void)
2262 {
2263 	struct desc_struct *gdt;
2264 	int err;
2265 
2266 	dmi_check_system(apm_dmi_table);
2267 
2268 	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2269 		printk(KERN_INFO "apm: BIOS not found.\n");
2270 		return -ENODEV;
2271 	}
2272 	printk(KERN_INFO
2273 	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2274 	       ((apm_info.bios.version >> 8) & 0xff),
2275 	       (apm_info.bios.version & 0xff),
2276 	       apm_info.bios.flags,
2277 	       driver_version);
2278 	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2279 		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2280 		return -ENODEV;
2281 	}
2282 
2283 	if (allow_ints)
2284 		apm_info.allow_ints = 1;
2285 	if (broken_psr)
2286 		apm_info.get_power_status_broken = 1;
2287 	if (realmode_power_off)
2288 		apm_info.realmode_power_off = 1;
2289 	/* User can override, but default is to trust DMI */
2290 	if (apm_disabled != -1)
2291 		apm_info.disabled = apm_disabled;
2292 
2293 	/*
2294 	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2295 	 * but is reportedly a 1.0 BIOS.
2296 	 */
2297 	if (apm_info.bios.version == 0x001)
2298 		apm_info.bios.version = 0x100;
2299 
2300 	/* BIOS < 1.2 doesn't set cseg_16_len */
2301 	if (apm_info.bios.version < 0x102)
2302 		apm_info.bios.cseg_16_len = 0; /* 64k */
2303 
2304 	if (debug) {
2305 		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2306 			apm_info.bios.cseg, apm_info.bios.offset,
2307 			apm_info.bios.cseg_16, apm_info.bios.dseg);
2308 		if (apm_info.bios.version > 0x100)
2309 			printk(" cseg len %x, dseg len %x",
2310 				apm_info.bios.cseg_len,
2311 				apm_info.bios.dseg_len);
2312 		if (apm_info.bios.version > 0x101)
2313 			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2314 		printk("\n");
2315 	}
2316 
2317 	if (apm_info.disabled) {
2318 		pr_notice("disabled on user request.\n");
2319 		return -ENODEV;
2320 	}
2321 	if ((num_online_cpus() > 1) && !power_off && !smp) {
2322 		pr_notice("disabled - APM is not SMP safe.\n");
2323 		apm_info.disabled = 1;
2324 		return -ENODEV;
2325 	}
2326 	if (!acpi_disabled) {
2327 		pr_notice("overridden by ACPI.\n");
2328 		apm_info.disabled = 1;
2329 		return -ENODEV;
2330 	}
2331 
2332 	/*
2333 	 * Set up the long jump entry point to the APM BIOS, which is called
2334 	 * from inline assembly.
2335 	 */
2336 	apm_bios_entry.offset = apm_info.bios.offset;
2337 	apm_bios_entry.segment = APM_CS;
2338 
2339 	/*
2340 	 * The APM 1.1 BIOS is supposed to provide limit information that it
2341 	 * recognizes.  Many machines do this correctly, but many others do
2342 	 * not restrict themselves to their claimed limit.  When this happens,
2343 	 * they will cause a segmentation violation in the kernel at boot time.
2344 	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2345 	 *
2346 	 * Note we only set APM segments on CPU zero, since we pin the APM
2347 	 * code to that CPU.
2348 	 */
2349 	gdt = get_cpu_gdt_rw(0);
2350 	set_desc_base(&gdt[APM_CS >> 3],
2351 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2352 	set_desc_base(&gdt[APM_CS_16 >> 3],
2353 		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2354 	set_desc_base(&gdt[APM_DS >> 3],
2355 		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2356 
2357 	proc_create_single("apm", 0, NULL, proc_apm_show);
2358 
2359 	kapmd_task = kthread_create(apm, NULL, "kapmd");
2360 	if (IS_ERR(kapmd_task)) {
2361 		pr_err("disabled - Unable to start kernel 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 		cpuidle_poll_state_init(&apm_idle_driver);
2387 		if (!cpuidle_register_driver(&apm_idle_driver))
2388 			if (cpuidle_register_device(&apm_cpuidle_device))
2389 				cpuidle_unregister_driver(&apm_idle_driver);
2390 	}
2391 
2392 	return 0;
2393 }
2394 
2395 static void __exit apm_exit(void)
2396 {
2397 	int error;
2398 
2399 	cpuidle_unregister_device(&apm_cpuidle_device);
2400 	cpuidle_unregister_driver(&apm_idle_driver);
2401 
2402 	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2403 	    && (apm_info.connection_version > 0x0100)) {
2404 		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2405 		if (error)
2406 			apm_error("disengage power management", error);
2407 	}
2408 	misc_deregister(&apm_device);
2409 	remove_proc_entry("apm", NULL);
2410 	if (power_off)
2411 		pm_power_off = NULL;
2412 	if (kapmd_task) {
2413 		kthread_stop(kapmd_task);
2414 		kapmd_task = NULL;
2415 	}
2416 }
2417 
2418 module_init(apm_init);
2419 module_exit(apm_exit);
2420 
2421 MODULE_AUTHOR("Stephen Rothwell");
2422 MODULE_DESCRIPTION("Advanced Power Management");
2423 MODULE_LICENSE("GPL");
2424 module_param(debug, bool, 0644);
2425 MODULE_PARM_DESC(debug, "Enable debug mode");
2426 module_param(power_off, bool, 0444);
2427 MODULE_PARM_DESC(power_off, "Enable power off");
2428 module_param(bounce_interval, int, 0444);
2429 MODULE_PARM_DESC(bounce_interval,
2430 		"Set the number of ticks to ignore suspend bounces");
2431 module_param(allow_ints, bool, 0444);
2432 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2433 module_param(broken_psr, bool, 0444);
2434 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2435 module_param(realmode_power_off, bool, 0444);
2436 MODULE_PARM_DESC(realmode_power_off,
2437 		"Switch to real mode before powering off");
2438 module_param(idle_threshold, int, 0444);
2439 MODULE_PARM_DESC(idle_threshold,
2440 	"System idle percentage above which to make APM BIOS idle calls");
2441 module_param(idle_period, int, 0444);
2442 MODULE_PARM_DESC(idle_period,
2443 	"Period (in sec/100) over which to calculate the idle percentage");
2444 module_param(smp, bool, 0444);
2445 MODULE_PARM_DESC(smp,
2446 	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2447 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
2448