1// SPDX-License-Identifier: GPL-2.0-or-later
2/* -*- linux-c -*-
3 * APM BIOS driver for Linux
4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
5 *
6 * Initial development of this driver was funded by NEC Australia P/L
7 *	and NEC Corporation
8 *
9 * October 1995, Rik Faith (faith@cs.unc.edu):
10 *    Minor enhancements and updates (to the patch set) for 1.3.x
11 *    Documentation
12 * January 1996, Rik Faith (faith@cs.unc.edu):
13 *    Make /proc/apm easy to format (bump driver version)
14 * March 1996, Rik Faith (faith@cs.unc.edu):
15 *    Prohibit APM BIOS calls unless apm_enabled.
16 *    (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
18 *    Version 1.0 and 1.1
19 * May 1996, Version 1.2
20 * Feb 1998, Version 1.3
21 * Feb 1998, Version 1.4
22 * Aug 1998, Version 1.5
23 * Sep 1998, Version 1.6
24 * Nov 1998, Version 1.7
25 * Jan 1999, Version 1.8
26 * Jan 1999, Version 1.9
27 * Oct 1999, Version 1.10
28 * Nov 1999, Version 1.11
29 * Jan 2000, Version 1.12
30 * Feb 2000, Version 1.13
31 * Nov 2000, Version 1.14
32 * Oct 2001, Version 1.15
33 * Jan 2002, Version 1.16
34 * Oct 2002, Version 1.16ac
35 *
36 * History:
37 *    0.6b: first version in official kernel, Linux 1.3.46
38 *    0.7: changed /proc/apm format, Linux 1.3.58
39 *    0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
40 *    0.9: only call bios if bios is present, Linux 1.3.72
41 *    1.0: use fixed device number, consolidate /proc/apm into this file,
42 *         Linux 1.3.85
43 *    1.1: support user-space standby and suspend, power off after system
44 *         halted, Linux 1.3.98
45 *    1.2: When resetting RTC after resume, take care so that the time
46 *         is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
47 *         <jtoth@princeton.edu>); improve interaction between
48 *         screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
49 *    1.2a:Simple change to stop mysterious bug reports with SMP also added
50 *	   levels to the printk calls. APM is not defined for SMP machines.
51 *         The new replacement for it is, but Linux doesn't yet support this.
52 *         Alan Cox Linux 2.1.55
53 *    1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
54 *    1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
55 *         Dean Gaudet <dgaudet@arctic.org>.
56 *         C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
57 *    1.5: Fix segment register reloading (in case of bad segments saved
58 *         across BIOS call).
59 *         Stephen Rothwell
60 *    1.6: Cope with compiler/assembler differences.
61 *         Only try to turn off the first display device.
62 *         Fix OOPS at power off with no APM BIOS by Jan Echternach
63 *                   <echter@informatik.uni-rostock.de>
64 *         Stephen Rothwell
65 *    1.7: Modify driver's cached copy of the disabled/disengaged flags
66 *         to reflect current state of APM BIOS.
67 *         Chris Rankin <rankinc@bellsouth.net>
68 *         Reset interrupt 0 timer to 100Hz after suspend
69 *         Chad Miller <cmiller@surfsouth.com>
70 *         Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
71 *         Richard Gooch <rgooch@atnf.csiro.au>
72 *         Allow boot time disabling of APM
73 *         Make boot messages far less verbose by default
74 *         Make asm safer
75 *         Stephen Rothwell
76 *    1.8: Add CONFIG_APM_RTC_IS_GMT
77 *         Richard Gooch <rgooch@atnf.csiro.au>
78 *         change APM_NOINTS to CONFIG_APM_ALLOW_INTS
79 *         remove dependency on CONFIG_PROC_FS
80 *         Stephen Rothwell
81 *    1.9: Fix small typo.  <laslo@wodip.opole.pl>
82 *         Try to cope with BIOS's that need to have all display
83 *         devices blanked and not just the first one.
84 *         Ross Paterson <ross@soi.city.ac.uk>
85 *         Fix segment limit setting it has always been wrong as
86 *         the segments needed to have byte granularity.
87 *         Mark a few things __init.
88 *         Add hack to allow power off of SMP systems by popular request.
89 *         Use CONFIG_SMP instead of __SMP__
90 *         Ignore BOUNCES for three seconds.
91 *         Stephen Rothwell
92 *   1.10: Fix for Thinkpad return code.
93 *         Merge 2.2 and 2.3 drivers.
94 *         Remove APM dependencies in arch/i386/kernel/process.c
95 *         Remove APM dependencies in drivers/char/sysrq.c
96 *         Reset time across standby.
97 *         Allow more initialisation on SMP.
98 *         Remove CONFIG_APM_POWER_OFF and make it boot time
99 *         configurable (default on).
100 *         Make debug only a boot time parameter (remove APM_DEBUG).
101 *         Try to blank all devices on any error.
102 *   1.11: Remove APM dependencies in drivers/char/console.c
103 *         Check nr_running to detect if we are idle (from
104 *         Borislav Deianov <borislav@lix.polytechnique.fr>)
105 *         Fix for bioses that don't zero the top part of the
106 *         entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
107 *         (reported by Panos Katsaloulis <teras@writeme.com>).
108 *         Real mode power off patch (Walter Hofmann
109 *         <Walter.Hofmann@physik.stud.uni-erlangen.de>).
110 *   1.12: Remove CONFIG_SMP as the compiler will optimize
111 *         the code away anyway (smp_num_cpus == 1 in UP)
112 *         noted by Artur Skawina <skawina@geocities.com>.
113 *         Make power off under SMP work again.
114 *         Fix thinko with initial engaging of BIOS.
115 *         Make sure power off only happens on CPU 0
116 *         (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
117 *         Do error notification to user mode if BIOS calls fail.
118 *         Move entrypoint offset fix to ...boot/setup.S
119 *         where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
120 *         Remove smp-power-off. SMP users must now specify
121 *         "apm=power-off" on the kernel command line. Suggested
122 *         by Jim Avera <jima@hal.com>, modified by Alan Cox
123 *         <alan@lxorguk.ukuu.org.uk>.
124 *         Register the /proc/apm entry even on SMP so that
125 *         scripts that check for it before doing power off
126 *         work (Jim Avera <jima@hal.com>).
127 *   1.13: Changes for new pm_ interfaces (Andy Henroid
128 *         <andy_henroid@yahoo.com>).
129 *         Modularize the code.
130 *         Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
131 *         is now the way life works).
132 *         Fix thinko in suspend() (wrong return).
133 *         Notify drivers on critical suspend.
134 *         Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
135 *         modified by sfr).
136 *         Disable interrupts while we are suspended (Andy Henroid
137 *         <andy_henroid@yahoo.com> fixed by sfr).
138 *         Make power off work on SMP again (Tony Hoyle
139 *         <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
140 *         Remove CONFIG_APM_SUSPEND_BOUNCE.  The bounce ignore
141 *         interval is now configurable.
142 *   1.14: Make connection version persist across module unload/load.
143 *         Enable and engage power management earlier.
144 *         Disengage power management on module unload.
145 *         Changed to use the sysrq-register hack for registering the
146 *         power off function called by magic sysrq based upon discussions
147 *         in irc://irc.openprojects.net/#kernelnewbies
148 *         (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
149 *         Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
150 *         (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
151 *         Work around byte swap bug in one of the Vaio's BIOS's
152 *         (Marc Boucher <marc@mbsi.ca>).
153 *         Exposed the disable flag to dmi so that we can handle known
154 *         broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
155 *   1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
156 *         calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
157 *         If an APM idle fails log it and idle sensibly
158 *   1.15: Don't queue events to clients who open the device O_WRONLY.
159 *         Don't expect replies from clients who open the device O_RDONLY.
160 *         (Idea from Thomas Hood)
161 *         Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
162 *   1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
163 *         Notify listeners of standby or suspend events before notifying
164 *         drivers. Return EBUSY to ioctl() if suspend is rejected.
165 *         (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
166 *         Ignore first resume after we generate our own resume event
167 *         after a suspend (Thomas Hood)
168 *         Daemonize now gets rid of our controlling terminal (sfr).
169 *         CONFIG_APM_CPU_IDLE now just affects the default value of
170 *         idle_threshold (sfr).
171 *         Change name of kernel apm daemon (as it no longer idles) (sfr).
172 *   1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
173 *	   make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
174 *	   TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
175 *
176 * APM 1.1 Reference:
177 *
178 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
179 *   (APM) BIOS Interface Specification, Revision 1.1, September 1993.
180 *   Intel Order Number 241704-001.  Microsoft Part Number 781-110-X01.
181 *
182 * [This document is available free from Intel by calling 800.628.8686 (fax
183 * 916.356.6100) or 800.548.4725; or from
184 * http://www.microsoft.com/whdc/archive/amp_12.mspx  It is also
185 * available from Microsoft by calling 206.882.8080.]
186 *
187 * APM 1.2 Reference:
188 *   Intel Corporation, Microsoft Corporation. Advanced Power Management
189 *   (APM) BIOS Interface Specification, Revision 1.2, February 1996.
190 *
191 * [This document is available from Microsoft at:
192 *    http://www.microsoft.com/whdc/archive/amp_12.mspx]
193 */
194
195#define pr_fmt(fmt) "apm: " fmt
196
197#include <linux/module.h>
198
199#include <linux/poll.h>
200#include <linux/types.h>
201#include <linux/stddef.h>
202#include <linux/timer.h>
203#include <linux/fcntl.h>
204#include <linux/slab.h>
205#include <linux/stat.h>
206#include <linux/proc_fs.h>
207#include <linux/seq_file.h>
208#include <linux/miscdevice.h>
209#include <linux/apm_bios.h>
210#include <linux/init.h>
211#include <linux/time.h>
212#include <linux/sched/signal.h>
213#include <linux/sched/cputime.h>
214#include <linux/pm.h>
215#include <linux/capability.h>
216#include <linux/device.h>
217#include <linux/kernel.h>
218#include <linux/freezer.h>
219#include <linux/smp.h>
220#include <linux/dmi.h>
221#include <linux/suspend.h>
222#include <linux/kthread.h>
223#include <linux/jiffies.h>
224#include <linux/acpi.h>
225#include <linux/syscore_ops.h>
226#include <linux/i8253.h>
227#include <linux/cpuidle.h>
228
229#include <linux/uaccess.h>
230#include <asm/desc.h>
231#include <asm/olpc.h>
232#include <asm/paravirt.h>
233#include <asm/reboot.h>
234#include <asm/nospec-branch.h>
235#include <asm/ibt.h>
236
237#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
238extern int (*console_blank_hook)(int);
239#endif
240
241/*
242 * Various options can be changed at boot time as follows:
243 * (We allow underscores for compatibility with the modules code)
244 *	apm=on/off			enable/disable APM
245 *	    [no-]allow[-_]ints		allow interrupts during BIOS calls
246 *	    [no-]broken[-_]psr		BIOS has a broken GetPowerStatus call
247 *	    [no-]realmode[-_]power[-_]off	switch to real mode before
248 *	    					powering off
249 *	    [no-]debug			log some debugging messages
250 *	    [no-]power[-_]off		power off on shutdown
251 *	    [no-]smp			Use apm even on an SMP box
252 *	    bounce[-_]interval=<n>	number of ticks to ignore suspend
253 *	    				bounces
254 *          idle[-_]threshold=<n>       System idle percentage above which to
255 *                                      make APM BIOS idle calls. Set it to
256 *                                      100 to disable.
257 *          idle[-_]period=<n>          Period (in 1/100s of a second) over
258 *                                      which the idle percentage is
259 *                                      calculated.
260 */
261
262/* KNOWN PROBLEM MACHINES:
263 *
264 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
265 *                         [Confirmed by TI representative]
266 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
267 *                    [Confirmed by BIOS disassembly]
268 *                    [This may work now ...]
269 * P: Toshiba 1950S: battery life information only gets updated after resume
270 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
271 * 	broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
272 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
273 * 	Neale Banks <neale@lowendale.com.au> December 2000
274 *
275 * Legend: U = unusable with APM patches
276 *         P = partially usable with APM patches
277 */
278
279/*
280 * Define as 1 to make the driver always call the APM BIOS busy
281 * routine even if the clock was not reported as slowed by the
282 * idle routine.  Otherwise, define as 0.
283 */
284#define ALWAYS_CALL_BUSY   1
285
286/*
287 * Define to make the APM BIOS calls zero all data segment registers (so
288 * that an incorrect BIOS implementation will cause a kernel panic if it
289 * tries to write to arbitrary memory).
290 */
291#define APM_ZERO_SEGS
292
293#include <asm/apm.h>
294
295/*
296 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
297 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
298 * David Chen <chen@ctpa04.mit.edu>
299 */
300#undef INIT_TIMER_AFTER_SUSPEND
301
302#ifdef INIT_TIMER_AFTER_SUSPEND
303#include <linux/timex.h>
304#include <asm/io.h>
305#include <linux/delay.h>
306#endif
307
308/*
309 * Need to poll the APM BIOS every second
310 */
311#define APM_CHECK_TIMEOUT	(HZ)
312
313/*
314 * Ignore suspend events for this amount of time after a resume
315 */
316#define DEFAULT_BOUNCE_INTERVAL	(3 * HZ)
317
318/*
319 * Maximum number of events stored
320 */
321#define APM_MAX_EVENTS		20
322
323/*
324 * The per-file APM data
325 */
326struct apm_user {
327	int		magic;
328	struct apm_user *next;
329	unsigned int	suser: 1;
330	unsigned int	writer: 1;
331	unsigned int	reader: 1;
332	unsigned int	suspend_wait: 1;
333	int		suspend_result;
334	int		suspends_pending;
335	int		standbys_pending;
336	int		suspends_read;
337	int		standbys_read;
338	int		event_head;
339	int		event_tail;
340	apm_event_t	events[APM_MAX_EVENTS];
341};
342
343/*
344 * The magic number in apm_user
345 */
346#define APM_BIOS_MAGIC		0x4101
347
348/*
349 * idle percentage above which bios idle calls are done
350 */
351#ifdef CONFIG_APM_CPU_IDLE
352#define DEFAULT_IDLE_THRESHOLD	95
353#else
354#define DEFAULT_IDLE_THRESHOLD	100
355#endif
356#define DEFAULT_IDLE_PERIOD	(100 / 3)
357
358static int apm_cpu_idle(struct cpuidle_device *dev,
359			struct cpuidle_driver *drv, int index);
360
361static struct cpuidle_driver apm_idle_driver = {
362	.name = "apm_idle",
363	.owner = THIS_MODULE,
364	.states = {
365		{ /* entry 0 is for polling */ },
366		{ /* entry 1 is for APM idle */
367			.name = "APM",
368			.desc = "APM idle",
369			.exit_latency = 250,	/* WAG */
370			.target_residency = 500,	/* WAG */
371			.enter = &apm_cpu_idle
372		},
373	},
374	.state_count = 2,
375};
376
377static struct cpuidle_device apm_cpuidle_device;
378
379/*
380 * Local variables
381 */
382__visible struct {
383	unsigned long	offset;
384	unsigned short	segment;
385} apm_bios_entry;
386static int clock_slowed;
387static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
388static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
389static int suspends_pending;
390static int standbys_pending;
391static int ignore_sys_suspend;
392static int ignore_normal_resume;
393static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
394
395static bool debug __read_mostly;
396static bool smp __read_mostly;
397static int apm_disabled = -1;
398#ifdef CONFIG_SMP
399static bool power_off;
400#else
401static bool power_off = 1;
402#endif
403static bool realmode_power_off;
404#ifdef CONFIG_APM_ALLOW_INTS
405static bool allow_ints = 1;
406#else
407static bool allow_ints;
408#endif
409static bool broken_psr;
410
411static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
412static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
413static struct apm_user *user_list;
414static DEFINE_SPINLOCK(user_list_lock);
415static DEFINE_MUTEX(apm_mutex);
416
417/*
418 * Set up a segment that references the real mode segment 0x40
419 * that extends up to the end of page zero (that we have reserved).
420 * This is for buggy BIOS's that refer to (real mode) segment 0x40
421 * even though they are called in protected mode.
422 */
423static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(DESC_DATA32_BIOS,
424			(unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
425
426static const char driver_version[] = "1.16ac";	/* no spaces */
427
428static struct task_struct *kapmd_task;
429
430/*
431 *	APM event names taken from the APM 1.2 specification. These are
432 *	the message codes that the BIOS uses to tell us about events
433 */
434static const char * const apm_event_name[] = {
435	"system standby",
436	"system suspend",
437	"normal resume",
438	"critical resume",
439	"low battery",
440	"power status change",
441	"update time",
442	"critical suspend",
443	"user standby",
444	"user suspend",
445	"system standby resume",
446	"capabilities change"
447};
448#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
449
450typedef struct lookup_t {
451	int	key;
452	char 	*msg;
453} lookup_t;
454
455/*
456 *	The BIOS returns a set of standard error codes in AX when the
457 *	carry flag is set.
458 */
459
460static const lookup_t error_table[] = {
461/* N/A	{ APM_SUCCESS,		"Operation succeeded" }, */
462	{ APM_DISABLED,		"Power management disabled" },
463	{ APM_CONNECTED,	"Real mode interface already connected" },
464	{ APM_NOT_CONNECTED,	"Interface not connected" },
465	{ APM_16_CONNECTED,	"16 bit interface already connected" },
466/* N/A	{ APM_16_UNSUPPORTED,	"16 bit interface not supported" }, */
467	{ APM_32_CONNECTED,	"32 bit interface already connected" },
468	{ APM_32_UNSUPPORTED,	"32 bit interface not supported" },
469	{ APM_BAD_DEVICE,	"Unrecognized device ID" },
470	{ APM_BAD_PARAM,	"Parameter out of range" },
471	{ APM_NOT_ENGAGED,	"Interface not engaged" },
472	{ APM_BAD_FUNCTION,     "Function not supported" },
473	{ APM_RESUME_DISABLED,	"Resume timer disabled" },
474	{ APM_BAD_STATE,	"Unable to enter requested state" },
475/* N/A	{ APM_NO_EVENTS,	"No events pending" }, */
476	{ APM_NO_ERROR,		"BIOS did not set a return code" },
477	{ APM_NOT_PRESENT,	"No APM present" }
478};
479#define ERROR_COUNT	ARRAY_SIZE(error_table)
480
481/**
482 *	apm_error	-	display an APM error
483 *	@str: information string
484 *	@err: APM BIOS return code
485 *
486 *	Write a meaningful log entry to the kernel log in the event of
487 *	an APM error.  Note that this also handles (negative) kernel errors.
488 */
489
490static void apm_error(char *str, int err)
491{
492	int i;
493
494	for (i = 0; i < ERROR_COUNT; i++)
495		if (error_table[i].key == err)
496			break;
497	if (i < ERROR_COUNT)
498		pr_notice("%s: %s\n", str, error_table[i].msg);
499	else if (err < 0)
500		pr_notice("%s: linux error code %i\n", str, err);
501	else
502		pr_notice("%s: unknown error code %#2.2x\n",
503		       str, err);
504}
505
506/*
507 * These are the actual BIOS calls.  Depending on APM_ZERO_SEGS and
508 * apm_info.allow_ints, we are being really paranoid here!  Not only
509 * are interrupts disabled, but all the segment registers (except SS)
510 * are saved and zeroed this means that if the BIOS tries to reference
511 * any data without explicitly loading the segment registers, the kernel
512 * will fault immediately rather than have some unforeseen circumstances
513 * for the rest of the kernel.  And it will be very obvious!  :-) Doing
514 * this depends on CS referring to the same physical memory as DS so that
515 * DS can be zeroed before the call. Unfortunately, we can't do anything
516 * about the stack segment/pointer.  Also, we tell the compiler that
517 * everything could change.
518 *
519 * Also, we KNOW that for the non error case of apm_bios_call, there
520 * is no useful data returned in the low order 8 bits of eax.
521 */
522
523static inline unsigned long __apm_irq_save(void)
524{
525	unsigned long flags;
526	local_save_flags(flags);
527	if (apm_info.allow_ints) {
528		if (irqs_disabled_flags(flags))
529			local_irq_enable();
530	} else
531		local_irq_disable();
532
533	return flags;
534}
535
536#define apm_irq_save(flags) \
537	do { flags = __apm_irq_save(); } while (0)
538
539static inline void apm_irq_restore(unsigned long flags)
540{
541	if (irqs_disabled_flags(flags))
542		local_irq_disable();
543	else if (irqs_disabled())
544		local_irq_enable();
545}
546
547#ifdef APM_ZERO_SEGS
548#	define APM_DECL_SEGS \
549		unsigned int saved_fs; unsigned int saved_gs;
550#	define APM_DO_SAVE_SEGS \
551		savesegment(fs, saved_fs); savesegment(gs, saved_gs)
552#	define APM_DO_RESTORE_SEGS \
553		loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
554#else
555#	define APM_DECL_SEGS
556#	define APM_DO_SAVE_SEGS
557#	define APM_DO_RESTORE_SEGS
558#endif
559
560struct apm_bios_call {
561	u32 func;
562	/* In and out */
563	u32 ebx;
564	u32 ecx;
565	/* Out only */
566	u32 eax;
567	u32 edx;
568	u32 esi;
569
570	/* Error: -ENOMEM, or bits 8-15 of eax */
571	int err;
572};
573
574/**
575 *	__apm_bios_call - Make an APM BIOS 32bit call
576 *	@_call: pointer to struct apm_bios_call.
577 *
578 *	Make an APM call using the 32bit protected mode interface. The
579 *	caller is responsible for knowing if APM BIOS is configured and
580 *	enabled. This call can disable interrupts for a long period of
581 *	time on some laptops.  The return value is in AH and the carry
582 *	flag is loaded into AL.  If there is an error, then the error
583 *	code is returned in AH (bits 8-15 of eax) and this function
584 *	returns non-zero.
585 *
586 *	Note: this makes the call on the current CPU.
587 */
588static long __apm_bios_call(void *_call)
589{
590	APM_DECL_SEGS
591	unsigned long		flags;
592	int			cpu;
593	struct desc_struct	save_desc_40;
594	struct desc_struct	*gdt;
595	struct apm_bios_call	*call = _call;
596	u64			ibt;
597
598	cpu = get_cpu();
599	BUG_ON(cpu != 0);
600	gdt = get_cpu_gdt_rw(cpu);
601	save_desc_40 = gdt[0x40 / 8];
602	gdt[0x40 / 8] = bad_bios_desc;
603
604	apm_irq_save(flags);
605	firmware_restrict_branch_speculation_start();
606	ibt = ibt_save(true);
607	APM_DO_SAVE_SEGS;
608	apm_bios_call_asm(call->func, call->ebx, call->ecx,
609			  &call->eax, &call->ebx, &call->ecx, &call->edx,
610			  &call->esi);
611	APM_DO_RESTORE_SEGS;
612	ibt_restore(ibt);
613	firmware_restrict_branch_speculation_end();
614	apm_irq_restore(flags);
615	gdt[0x40 / 8] = save_desc_40;
616	put_cpu();
617
618	return call->eax & 0xff;
619}
620
621/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
622static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
623{
624	int ret;
625
626	/* Don't bother with work_on_cpu in the common case, so we don't
627	 * have to worry about OOM or overhead. */
628	if (get_cpu() == 0) {
629		ret = fn(call);
630		put_cpu();
631	} else {
632		put_cpu();
633		ret = work_on_cpu(0, fn, call);
634	}
635
636	/* work_on_cpu can fail with -ENOMEM */
637	if (ret < 0)
638		call->err = ret;
639	else
640		call->err = (call->eax >> 8) & 0xff;
641
642	return ret;
643}
644
645/**
646 *	apm_bios_call	-	Make an APM BIOS 32bit call (on CPU 0)
647 *	@call: the apm_bios_call registers.
648 *
649 *	If there is an error, it is returned in @call.err.
650 */
651static int apm_bios_call(struct apm_bios_call *call)
652{
653	return on_cpu0(__apm_bios_call, call);
654}
655
656/**
657 *	__apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
658 *	@_call: pointer to struct apm_bios_call.
659 *
660 *	Make a BIOS call that returns one value only, or just status.
661 *	If there is an error, then the error code is returned in AH
662 *	(bits 8-15 of eax) and this function returns non-zero (it can
663 *	also return -ENOMEM). This is used for simpler BIOS operations.
664 *	This call may hold interrupts off for a long time on some laptops.
665 *
666 *	Note: this makes the call on the current CPU.
667 */
668static long __apm_bios_call_simple(void *_call)
669{
670	u8			error;
671	APM_DECL_SEGS
672	unsigned long		flags;
673	int			cpu;
674	struct desc_struct	save_desc_40;
675	struct desc_struct	*gdt;
676	struct apm_bios_call	*call = _call;
677	u64			ibt;
678
679	cpu = get_cpu();
680	BUG_ON(cpu != 0);
681	gdt = get_cpu_gdt_rw(cpu);
682	save_desc_40 = gdt[0x40 / 8];
683	gdt[0x40 / 8] = bad_bios_desc;
684
685	apm_irq_save(flags);
686	firmware_restrict_branch_speculation_start();
687	ibt = ibt_save(true);
688	APM_DO_SAVE_SEGS;
689	error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
690					 &call->eax);
691	APM_DO_RESTORE_SEGS;
692	ibt_restore(ibt);
693	firmware_restrict_branch_speculation_end();
694	apm_irq_restore(flags);
695	gdt[0x40 / 8] = save_desc_40;
696	put_cpu();
697	return error;
698}
699
700/**
701 *	apm_bios_call_simple	-	make a simple APM BIOS 32bit call
702 *	@func: APM function to invoke
703 *	@ebx_in: EBX register value for BIOS call
704 *	@ecx_in: ECX register value for BIOS call
705 *	@eax: EAX register on return from the BIOS call
706 *	@err: bits
707 *
708 *	Make a BIOS call that returns one value only, or just status.
709 *	If there is an error, then the error code is returned in @err
710 *	and this function returns non-zero. This is used for simpler
711 *	BIOS operations.  This call may hold interrupts off for a long
712 *	time on some laptops.
713 */
714static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
715				int *err)
716{
717	struct apm_bios_call call;
718	int ret;
719
720	call.func = func;
721	call.ebx = ebx_in;
722	call.ecx = ecx_in;
723
724	ret = on_cpu0(__apm_bios_call_simple, &call);
725	*eax = call.eax;
726	*err = call.err;
727	return ret;
728}
729
730/**
731 *	apm_driver_version	-	APM driver version
732 *	@val:	loaded with the APM version on return
733 *
734 *	Retrieve the APM version supported by the BIOS. This is only
735 *	supported for APM 1.1 or higher. An error indicates APM 1.0 is
736 *	probably present.
737 *
738 *	On entry val should point to a value indicating the APM driver
739 *	version with the high byte being the major and the low byte the
740 *	minor number both in BCD
741 *
742 *	On return it will hold the BIOS revision supported in the
743 *	same format.
744 */
745
746static int apm_driver_version(u_short *val)
747{
748	u32 eax;
749	int err;
750
751	if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
752		return err;
753	*val = eax;
754	return APM_SUCCESS;
755}
756
757/**
758 *	apm_get_event	-	get an APM event from the BIOS
759 *	@event: pointer to the event
760 *	@info: point to the event information
761 *
762 *	The APM BIOS provides a polled information for event
763 *	reporting. The BIOS expects to be polled at least every second
764 *	when events are pending. When a message is found the caller should
765 *	poll until no more messages are present.  However, this causes
766 *	problems on some laptops where a suspend event notification is
767 *	not cleared until it is acknowledged.
768 *
769 *	Additional information is returned in the info pointer, providing
770 *	that APM 1.2 is in use. If no messages are pending the value 0x80
771 *	is returned (No power management events pending).
772 */
773static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
774{
775	struct apm_bios_call call;
776
777	call.func = APM_FUNC_GET_EVENT;
778	call.ebx = call.ecx = 0;
779
780	if (apm_bios_call(&call))
781		return call.err;
782
783	*event = call.ebx;
784	if (apm_info.connection_version < 0x0102)
785		*info = ~0; /* indicate info not valid */
786	else
787		*info = call.ecx;
788	return APM_SUCCESS;
789}
790
791/**
792 *	set_power_state	-	set the power management state
793 *	@what: which items to transition
794 *	@state: state to transition to
795 *
796 *	Request an APM change of state for one or more system devices. The
797 *	processor state must be transitioned last of all. what holds the
798 *	class of device in the upper byte and the device number (0xFF for
799 *	all) for the object to be transitioned.
800 *
801 *	The state holds the state to transition to, which may in fact
802 *	be an acceptance of a BIOS requested state change.
803 */
804
805static int set_power_state(u_short what, u_short state)
806{
807	u32 eax;
808	int err;
809
810	if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
811		return err;
812	return APM_SUCCESS;
813}
814
815/**
816 *	set_system_power_state - set system wide power state
817 *	@state: which state to enter
818 *
819 *	Transition the entire system into a new APM power state.
820 */
821
822static int set_system_power_state(u_short state)
823{
824	return set_power_state(APM_DEVICE_ALL, state);
825}
826
827/**
828 *	apm_do_idle	-	perform power saving
829 *
830 *	This function notifies the BIOS that the processor is (in the view
831 *	of the OS) idle. It returns -1 in the event that the BIOS refuses
832 *	to handle the idle request. On a success the function returns 1
833 *	if the BIOS did clock slowing or 0 otherwise.
834 */
835
836static int apm_do_idle(void)
837{
838	u32 eax;
839	u8 ret = 0;
840	int idled = 0;
841	int err = 0;
842
843	if (!need_resched()) {
844		idled = 1;
845		ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
846	}
847
848	if (!idled)
849		return 0;
850
851	if (ret) {
852		static unsigned long t;
853
854		/* This always fails on some SMP boards running UP kernels.
855		 * Only report the failure the first 5 times.
856		 */
857		if (++t < 5) {
858			printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
859			t = jiffies;
860		}
861		return -1;
862	}
863	clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
864	return clock_slowed;
865}
866
867/**
868 *	apm_do_busy	-	inform the BIOS the CPU is busy
869 *
870 *	Request that the BIOS brings the CPU back to full performance.
871 */
872
873static void apm_do_busy(void)
874{
875	u32 dummy;
876	int err;
877
878	if (clock_slowed || ALWAYS_CALL_BUSY) {
879		(void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
880		clock_slowed = 0;
881	}
882}
883
884/*
885 * If no process has really been interested in
886 * the CPU for some time, we want to call BIOS
887 * power management - we probably want
888 * to conserve power.
889 */
890#define IDLE_CALC_LIMIT	(HZ * 100)
891#define IDLE_LEAKY_MAX	16
892
893/**
894 * apm_cpu_idle		-	cpu idling for APM capable Linux
895 *
896 * This is the idling function the kernel executes when APM is available. It
897 * tries to do BIOS powermanagement based on the average system idle time.
898 * Furthermore it calls the system default idle routine.
899 */
900
901static int apm_cpu_idle(struct cpuidle_device *dev,
902	struct cpuidle_driver *drv, int index)
903{
904	static int use_apm_idle; /* = 0 */
905	static unsigned int last_jiffies; /* = 0 */
906	static u64 last_stime; /* = 0 */
907	u64 stime, utime;
908
909	int apm_idle_done = 0;
910	unsigned int jiffies_since_last_check = jiffies - last_jiffies;
911	unsigned int bucket;
912
913recalc:
914	task_cputime(current, &utime, &stime);
915	if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
916		use_apm_idle = 0;
917	} else if (jiffies_since_last_check > idle_period) {
918		unsigned int idle_percentage;
919
920		idle_percentage = nsecs_to_jiffies(stime - last_stime);
921		idle_percentage *= 100;
922		idle_percentage /= jiffies_since_last_check;
923		use_apm_idle = (idle_percentage > idle_threshold);
924		if (apm_info.forbid_idle)
925			use_apm_idle = 0;
926	}
927
928	last_jiffies = jiffies;
929	last_stime = stime;
930
931	bucket = IDLE_LEAKY_MAX;
932
933	while (!need_resched()) {
934		if (use_apm_idle) {
935			unsigned int t;
936
937			t = jiffies;
938			switch (apm_do_idle()) {
939			case 0:
940				apm_idle_done = 1;
941				if (t != jiffies) {
942					if (bucket) {
943						bucket = IDLE_LEAKY_MAX;
944						continue;
945					}
946				} else if (bucket) {
947					bucket--;
948					continue;
949				}
950				break;
951			case 1:
952				apm_idle_done = 1;
953				break;
954			default: /* BIOS refused */
955				break;
956			}
957		}
958		default_idle();
959		local_irq_disable();
960		jiffies_since_last_check = jiffies - last_jiffies;
961		if (jiffies_since_last_check > idle_period)
962			goto recalc;
963	}
964
965	if (apm_idle_done)
966		apm_do_busy();
967
968	return index;
969}
970
971/**
972 *	apm_power_off	-	ask the BIOS to power off
973 *
974 *	Handle the power off sequence. This is the one piece of code we
975 *	will execute even on SMP machines. In order to deal with BIOS
976 *	bugs we support real mode APM BIOS power off calls. We also make
977 *	the SMP call on CPU0 as some systems will only honour this call
978 *	on their first cpu.
979 */
980
981static void apm_power_off(void)
982{
983	/* Some bioses don't like being called from CPU != 0 */
984	if (apm_info.realmode_power_off) {
985		set_cpus_allowed_ptr(current, cpumask_of(0));
986		machine_real_restart(MRR_APM);
987	} else {
988		(void)set_system_power_state(APM_STATE_OFF);
989	}
990}
991
992#ifdef CONFIG_APM_DO_ENABLE
993
994/**
995 *	apm_enable_power_management - enable BIOS APM power management
996 *	@enable: enable yes/no
997 *
998 *	Enable or disable the APM BIOS power services.
999 */
1000
1001static int apm_enable_power_management(int enable)
1002{
1003	u32 eax;
1004	int err;
1005
1006	if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1007		return APM_NOT_ENGAGED;
1008	if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1009				 enable, &eax, &err))
1010		return err;
1011	if (enable)
1012		apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1013	else
1014		apm_info.bios.flags |= APM_BIOS_DISABLED;
1015	return APM_SUCCESS;
1016}
1017#endif
1018
1019/**
1020 *	apm_get_power_status	-	get current power state
1021 *	@status: returned status
1022 *	@bat: battery info
1023 *	@life: estimated life
1024 *
1025 *	Obtain the current power status from the APM BIOS. We return a
1026 *	status which gives the rough battery status, and current power
1027 *	source. The bat value returned give an estimate as a percentage
1028 *	of life and a status value for the battery. The estimated life
1029 *	if reported is a lifetime in seconds/minutes at current power
1030 *	consumption.
1031 */
1032
1033static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1034{
1035	struct apm_bios_call call;
1036
1037	call.func = APM_FUNC_GET_STATUS;
1038	call.ebx = APM_DEVICE_ALL;
1039	call.ecx = 0;
1040
1041	if (apm_info.get_power_status_broken)
1042		return APM_32_UNSUPPORTED;
1043	if (apm_bios_call(&call)) {
1044		if (!call.err)
1045			return APM_NO_ERROR;
1046		return call.err;
1047	}
1048	*status = call.ebx;
1049	*bat = call.ecx;
1050	if (apm_info.get_power_status_swabinminutes) {
1051		*life = swab16((u16)call.edx);
1052		*life |= 0x8000;
1053	} else
1054		*life = call.edx;
1055	return APM_SUCCESS;
1056}
1057
1058/**
1059 *	apm_engage_power_management	-	enable PM on a device
1060 *	@device: identity of device
1061 *	@enable: on/off
1062 *
1063 *	Activate or deactivate power management on either a specific device
1064 *	or the entire system (%APM_DEVICE_ALL).
1065 */
1066
1067static int apm_engage_power_management(u_short device, int enable)
1068{
1069	u32 eax;
1070	int err;
1071
1072	if ((enable == 0) && (device == APM_DEVICE_ALL)
1073	    && (apm_info.bios.flags & APM_BIOS_DISABLED))
1074		return APM_DISABLED;
1075	if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1076				 &eax, &err))
1077		return err;
1078	if (device == APM_DEVICE_ALL) {
1079		if (enable)
1080			apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1081		else
1082			apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1083	}
1084	return APM_SUCCESS;
1085}
1086
1087#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1088
1089/**
1090 *	apm_console_blank	-	blank the display
1091 *	@blank: on/off
1092 *
1093 *	Attempt to blank the console, firstly by blanking just video device
1094 *	zero, and if that fails (some BIOSes don't support it) then it blanks
1095 *	all video devices. Typically the BIOS will do laptop backlight and
1096 *	monitor powerdown for us.
1097 */
1098
1099static int apm_console_blank(int blank)
1100{
1101	int error = APM_NOT_ENGAGED; /* silence gcc */
1102	int i;
1103	u_short state;
1104	static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1105
1106	state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1107
1108	for (i = 0; i < ARRAY_SIZE(dev); i++) {
1109		error = set_power_state(dev[i], state);
1110
1111		if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1112			return 1;
1113
1114		if (error == APM_NOT_ENGAGED)
1115			break;
1116	}
1117
1118	if (error == APM_NOT_ENGAGED) {
1119		static int tried;
1120		int eng_error;
1121		if (tried++ == 0) {
1122			eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1123			if (eng_error) {
1124				apm_error("set display", error);
1125				apm_error("engage interface", eng_error);
1126				return 0;
1127			} else
1128				return apm_console_blank(blank);
1129		}
1130	}
1131	apm_error("set display", error);
1132	return 0;
1133}
1134#endif
1135
1136static int queue_empty(struct apm_user *as)
1137{
1138	return as->event_head == as->event_tail;
1139}
1140
1141static apm_event_t get_queued_event(struct apm_user *as)
1142{
1143	if (++as->event_tail >= APM_MAX_EVENTS)
1144		as->event_tail = 0;
1145	return as->events[as->event_tail];
1146}
1147
1148static void queue_event(apm_event_t event, struct apm_user *sender)
1149{
1150	struct apm_user *as;
1151
1152	spin_lock(&user_list_lock);
1153	if (user_list == NULL)
1154		goto out;
1155	for (as = user_list; as != NULL; as = as->next) {
1156		if ((as == sender) || (!as->reader))
1157			continue;
1158		if (++as->event_head >= APM_MAX_EVENTS)
1159			as->event_head = 0;
1160
1161		if (as->event_head == as->event_tail) {
1162			static int notified;
1163
1164			if (notified++ == 0)
1165				pr_err("an event queue overflowed\n");
1166			if (++as->event_tail >= APM_MAX_EVENTS)
1167				as->event_tail = 0;
1168		}
1169		as->events[as->event_head] = event;
1170		if (!as->suser || !as->writer)
1171			continue;
1172		switch (event) {
1173		case APM_SYS_SUSPEND:
1174		case APM_USER_SUSPEND:
1175			as->suspends_pending++;
1176			suspends_pending++;
1177			break;
1178
1179		case APM_SYS_STANDBY:
1180		case APM_USER_STANDBY:
1181			as->standbys_pending++;
1182			standbys_pending++;
1183			break;
1184		}
1185	}
1186	wake_up_interruptible(&apm_waitqueue);
1187out:
1188	spin_unlock(&user_list_lock);
1189}
1190
1191static void reinit_timer(void)
1192{
1193#ifdef INIT_TIMER_AFTER_SUSPEND
1194	unsigned long flags;
1195
1196	raw_spin_lock_irqsave(&i8253_lock, flags);
1197	/* set the clock to HZ */
1198	outb_p(0x34, PIT_MODE);		/* binary, mode 2, LSB/MSB, ch 0 */
1199	udelay(10);
1200	outb_p(LATCH & 0xff, PIT_CH0);	/* LSB */
1201	udelay(10);
1202	outb_p(LATCH >> 8, PIT_CH0);	/* MSB */
1203	udelay(10);
1204	raw_spin_unlock_irqrestore(&i8253_lock, flags);
1205#endif
1206}
1207
1208static int suspend(int vetoable)
1209{
1210	int err;
1211	struct apm_user	*as;
1212
1213	dpm_suspend_start(PMSG_SUSPEND);
1214	dpm_suspend_end(PMSG_SUSPEND);
1215
1216	local_irq_disable();
1217	syscore_suspend();
1218
1219	local_irq_enable();
1220
1221	save_processor_state();
1222	err = set_system_power_state(APM_STATE_SUSPEND);
1223	ignore_normal_resume = 1;
1224	restore_processor_state();
1225
1226	local_irq_disable();
1227	reinit_timer();
1228
1229	if (err == APM_NO_ERROR)
1230		err = APM_SUCCESS;
1231	if (err != APM_SUCCESS)
1232		apm_error("suspend", err);
1233	err = (err == APM_SUCCESS) ? 0 : -EIO;
1234
1235	syscore_resume();
1236	local_irq_enable();
1237
1238	dpm_resume_start(PMSG_RESUME);
1239	dpm_resume_end(PMSG_RESUME);
1240
1241	queue_event(APM_NORMAL_RESUME, NULL);
1242	spin_lock(&user_list_lock);
1243	for (as = user_list; as != NULL; as = as->next) {
1244		as->suspend_wait = 0;
1245		as->suspend_result = err;
1246	}
1247	spin_unlock(&user_list_lock);
1248	wake_up_interruptible(&apm_suspend_waitqueue);
1249	return err;
1250}
1251
1252static void standby(void)
1253{
1254	int err;
1255
1256	dpm_suspend_end(PMSG_SUSPEND);
1257
1258	local_irq_disable();
1259	syscore_suspend();
1260	local_irq_enable();
1261
1262	err = set_system_power_state(APM_STATE_STANDBY);
1263	if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1264		apm_error("standby", err);
1265
1266	local_irq_disable();
1267	syscore_resume();
1268	local_irq_enable();
1269
1270	dpm_resume_start(PMSG_RESUME);
1271}
1272
1273static apm_event_t get_event(void)
1274{
1275	int error;
1276	apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1277	apm_eventinfo_t	info;
1278
1279	static int notified;
1280
1281	/* we don't use the eventinfo */
1282	error = apm_get_event(&event, &info);
1283	if (error == APM_SUCCESS)
1284		return event;
1285
1286	if ((error != APM_NO_EVENTS) && (notified++ == 0))
1287		apm_error("get_event", error);
1288
1289	return 0;
1290}
1291
1292static void check_events(void)
1293{
1294	apm_event_t event;
1295	static unsigned long last_resume;
1296	static int ignore_bounce;
1297
1298	while ((event = get_event()) != 0) {
1299		if (debug) {
1300			if (event <= NR_APM_EVENT_NAME)
1301				printk(KERN_DEBUG "apm: received %s notify\n",
1302				       apm_event_name[event - 1]);
1303			else
1304				printk(KERN_DEBUG "apm: received unknown "
1305				       "event 0x%02x\n", event);
1306		}
1307		if (ignore_bounce
1308		    && (time_after(jiffies, last_resume + bounce_interval)))
1309			ignore_bounce = 0;
1310
1311		switch (event) {
1312		case APM_SYS_STANDBY:
1313		case APM_USER_STANDBY:
1314			queue_event(event, NULL);
1315			if (standbys_pending <= 0)
1316				standby();
1317			break;
1318
1319		case APM_USER_SUSPEND:
1320#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1321			if (apm_info.connection_version > 0x100)
1322				set_system_power_state(APM_STATE_REJECT);
1323			break;
1324#endif
1325		case APM_SYS_SUSPEND:
1326			if (ignore_bounce) {
1327				if (apm_info.connection_version > 0x100)
1328					set_system_power_state(APM_STATE_REJECT);
1329				break;
1330			}
1331			/*
1332			 * If we are already processing a SUSPEND,
1333			 * then further SUSPEND events from the BIOS
1334			 * will be ignored.  We also return here to
1335			 * cope with the fact that the Thinkpads keep
1336			 * sending a SUSPEND event until something else
1337			 * happens!
1338			 */
1339			if (ignore_sys_suspend)
1340				return;
1341			ignore_sys_suspend = 1;
1342			queue_event(event, NULL);
1343			if (suspends_pending <= 0)
1344				(void) suspend(1);
1345			break;
1346
1347		case APM_NORMAL_RESUME:
1348		case APM_CRITICAL_RESUME:
1349		case APM_STANDBY_RESUME:
1350			ignore_sys_suspend = 0;
1351			last_resume = jiffies;
1352			ignore_bounce = 1;
1353			if ((event != APM_NORMAL_RESUME)
1354			    || (ignore_normal_resume == 0)) {
1355				dpm_resume_end(PMSG_RESUME);
1356				queue_event(event, NULL);
1357			}
1358			ignore_normal_resume = 0;
1359			break;
1360
1361		case APM_CAPABILITY_CHANGE:
1362		case APM_LOW_BATTERY:
1363		case APM_POWER_STATUS_CHANGE:
1364			queue_event(event, NULL);
1365			/* If needed, notify drivers here */
1366			break;
1367
1368		case APM_UPDATE_TIME:
1369			break;
1370
1371		case APM_CRITICAL_SUSPEND:
1372			/*
1373			 * We are not allowed to reject a critical suspend.
1374			 */
1375			(void)suspend(0);
1376			break;
1377		}
1378	}
1379}
1380
1381static void apm_event_handler(void)
1382{
1383	static int pending_count = 4;
1384	int err;
1385
1386	if ((standbys_pending > 0) || (suspends_pending > 0)) {
1387		if ((apm_info.connection_version > 0x100) &&
1388		    (pending_count-- <= 0)) {
1389			pending_count = 4;
1390			if (debug)
1391				printk(KERN_DEBUG "apm: setting state busy\n");
1392			err = set_system_power_state(APM_STATE_BUSY);
1393			if (err)
1394				apm_error("busy", err);
1395		}
1396	} else
1397		pending_count = 4;
1398	check_events();
1399}
1400
1401/*
1402 * This is the APM thread main loop.
1403 */
1404
1405static void apm_mainloop(void)
1406{
1407	DECLARE_WAITQUEUE(wait, current);
1408
1409	add_wait_queue(&apm_waitqueue, &wait);
1410	set_current_state(TASK_INTERRUPTIBLE);
1411	for (;;) {
1412		schedule_timeout(APM_CHECK_TIMEOUT);
1413		if (kthread_should_stop())
1414			break;
1415		/*
1416		 * Ok, check all events, check for idle (and mark us sleeping
1417		 * so as not to count towards the load average)..
1418		 */
1419		set_current_state(TASK_INTERRUPTIBLE);
1420		apm_event_handler();
1421	}
1422	remove_wait_queue(&apm_waitqueue, &wait);
1423}
1424
1425static int check_apm_user(struct apm_user *as, const char *func)
1426{
1427	if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1428		pr_err("%s passed bad filp\n", func);
1429		return 1;
1430	}
1431	return 0;
1432}
1433
1434static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1435{
1436	struct apm_user *as;
1437	int i;
1438	apm_event_t event;
1439
1440	as = fp->private_data;
1441	if (check_apm_user(as, "read"))
1442		return -EIO;
1443	if ((int)count < sizeof(apm_event_t))
1444		return -EINVAL;
1445	if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1446		return -EAGAIN;
1447	wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1448	i = count;
1449	while ((i >= sizeof(event)) && !queue_empty(as)) {
1450		event = get_queued_event(as);
1451		if (copy_to_user(buf, &event, sizeof(event))) {
1452			if (i < count)
1453				break;
1454			return -EFAULT;
1455		}
1456		switch (event) {
1457		case APM_SYS_SUSPEND:
1458		case APM_USER_SUSPEND:
1459			as->suspends_read++;
1460			break;
1461
1462		case APM_SYS_STANDBY:
1463		case APM_USER_STANDBY:
1464			as->standbys_read++;
1465			break;
1466		}
1467		buf += sizeof(event);
1468		i -= sizeof(event);
1469	}
1470	if (i < count)
1471		return count - i;
1472	if (signal_pending(current))
1473		return -ERESTARTSYS;
1474	return 0;
1475}
1476
1477static __poll_t do_poll(struct file *fp, poll_table *wait)
1478{
1479	struct apm_user *as;
1480
1481	as = fp->private_data;
1482	if (check_apm_user(as, "poll"))
1483		return 0;
1484	poll_wait(fp, &apm_waitqueue, wait);
1485	if (!queue_empty(as))
1486		return EPOLLIN | EPOLLRDNORM;
1487	return 0;
1488}
1489
1490static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1491{
1492	struct apm_user *as;
1493	int ret;
1494
1495	as = filp->private_data;
1496	if (check_apm_user(as, "ioctl"))
1497		return -EIO;
1498	if (!as->suser || !as->writer)
1499		return -EPERM;
1500	switch (cmd) {
1501	case APM_IOC_STANDBY:
1502		mutex_lock(&apm_mutex);
1503		if (as->standbys_read > 0) {
1504			as->standbys_read--;
1505			as->standbys_pending--;
1506			standbys_pending--;
1507		} else
1508			queue_event(APM_USER_STANDBY, as);
1509		if (standbys_pending <= 0)
1510			standby();
1511		mutex_unlock(&apm_mutex);
1512		break;
1513	case APM_IOC_SUSPEND:
1514		mutex_lock(&apm_mutex);
1515		if (as->suspends_read > 0) {
1516			as->suspends_read--;
1517			as->suspends_pending--;
1518			suspends_pending--;
1519		} else
1520			queue_event(APM_USER_SUSPEND, as);
1521		if (suspends_pending <= 0) {
1522			ret = suspend(1);
1523			mutex_unlock(&apm_mutex);
1524		} else {
1525			as->suspend_wait = 1;
1526			mutex_unlock(&apm_mutex);
1527			wait_event_interruptible(apm_suspend_waitqueue,
1528					as->suspend_wait == 0);
1529			ret = as->suspend_result;
1530		}
1531		return ret;
1532	default:
1533		return -ENOTTY;
1534	}
1535	return 0;
1536}
1537
1538static int do_release(struct inode *inode, struct file *filp)
1539{
1540	struct apm_user *as;
1541
1542	as = filp->private_data;
1543	if (check_apm_user(as, "release"))
1544		return 0;
1545	filp->private_data = NULL;
1546	if (as->standbys_pending > 0) {
1547		standbys_pending -= as->standbys_pending;
1548		if (standbys_pending <= 0)
1549			standby();
1550	}
1551	if (as->suspends_pending > 0) {
1552		suspends_pending -= as->suspends_pending;
1553		if (suspends_pending <= 0)
1554			(void) suspend(1);
1555	}
1556	spin_lock(&user_list_lock);
1557	if (user_list == as)
1558		user_list = as->next;
1559	else {
1560		struct apm_user *as1;
1561
1562		for (as1 = user_list;
1563		     (as1 != NULL) && (as1->next != as);
1564		     as1 = as1->next)
1565			;
1566		if (as1 == NULL)
1567			pr_err("filp not in user list\n");
1568		else
1569			as1->next = as->next;
1570	}
1571	spin_unlock(&user_list_lock);
1572	kfree(as);
1573	return 0;
1574}
1575
1576static int do_open(struct inode *inode, struct file *filp)
1577{
1578	struct apm_user *as;
1579
1580	as = kmalloc(sizeof(*as), GFP_KERNEL);
1581	if (as == NULL)
1582		return -ENOMEM;
1583
1584	as->magic = APM_BIOS_MAGIC;
1585	as->event_tail = as->event_head = 0;
1586	as->suspends_pending = as->standbys_pending = 0;
1587	as->suspends_read = as->standbys_read = 0;
1588	/*
1589	 * XXX - this is a tiny bit broken, when we consider BSD
1590	 * process accounting. If the device is opened by root, we
1591	 * instantly flag that we used superuser privs. Who knows,
1592	 * we might close the device immediately without doing a
1593	 * privileged operation -- cevans
1594	 */
1595	as->suser = capable(CAP_SYS_ADMIN);
1596	as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1597	as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1598	spin_lock(&user_list_lock);
1599	as->next = user_list;
1600	user_list = as;
1601	spin_unlock(&user_list_lock);
1602	filp->private_data = as;
1603	return 0;
1604}
1605
1606#ifdef CONFIG_PROC_FS
1607static int proc_apm_show(struct seq_file *m, void *v)
1608{
1609	unsigned short	bx;
1610	unsigned short	cx;
1611	unsigned short	dx;
1612	int		error;
1613	unsigned short  ac_line_status = 0xff;
1614	unsigned short  battery_status = 0xff;
1615	unsigned short  battery_flag   = 0xff;
1616	int		percentage     = -1;
1617	int             time_units     = -1;
1618	char            *units         = "?";
1619
1620	if ((num_online_cpus() == 1) &&
1621	    !(error = apm_get_power_status(&bx, &cx, &dx))) {
1622		ac_line_status = (bx >> 8) & 0xff;
1623		battery_status = bx & 0xff;
1624		if ((cx & 0xff) != 0xff)
1625			percentage = cx & 0xff;
1626
1627		if (apm_info.connection_version > 0x100) {
1628			battery_flag = (cx >> 8) & 0xff;
1629			if (dx != 0xffff) {
1630				units = (dx & 0x8000) ? "min" : "sec";
1631				time_units = dx & 0x7fff;
1632			}
1633		}
1634	}
1635	/* Arguments, with symbols from linux/apm_bios.h.  Information is
1636	   from the Get Power Status (0x0a) call unless otherwise noted.
1637
1638	   0) Linux driver version (this will change if format changes)
1639	   1) APM BIOS Version.  Usually 1.0, 1.1 or 1.2.
1640	   2) APM flags from APM Installation Check (0x00):
1641	      bit 0: APM_16_BIT_SUPPORT
1642	      bit 1: APM_32_BIT_SUPPORT
1643	      bit 2: APM_IDLE_SLOWS_CLOCK
1644	      bit 3: APM_BIOS_DISABLED
1645	      bit 4: APM_BIOS_DISENGAGED
1646	   3) AC line status
1647	      0x00: Off-line
1648	      0x01: On-line
1649	      0x02: On backup power (BIOS >= 1.1 only)
1650	      0xff: Unknown
1651	   4) Battery status
1652	      0x00: High
1653	      0x01: Low
1654	      0x02: Critical
1655	      0x03: Charging
1656	      0x04: Selected battery not present (BIOS >= 1.2 only)
1657	      0xff: Unknown
1658	   5) Battery flag
1659	      bit 0: High
1660	      bit 1: Low
1661	      bit 2: Critical
1662	      bit 3: Charging
1663	      bit 7: No system battery
1664	      0xff: Unknown
1665	   6) Remaining battery life (percentage of charge):
1666	      0-100: valid
1667	      -1: Unknown
1668	   7) Remaining battery life (time units):
1669	      Number of remaining minutes or seconds
1670	      -1: Unknown
1671	   8) min = minutes; sec = seconds */
1672
1673	seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1674		   driver_version,
1675		   (apm_info.bios.version >> 8) & 0xff,
1676		   apm_info.bios.version & 0xff,
1677		   apm_info.bios.flags,
1678		   ac_line_status,
1679		   battery_status,
1680		   battery_flag,
1681		   percentage,
1682		   time_units,
1683		   units);
1684	return 0;
1685}
1686#endif
1687
1688static int apm(void *unused)
1689{
1690	unsigned short	bx;
1691	unsigned short	cx;
1692	unsigned short	dx;
1693	int		error;
1694	char 		*power_stat;
1695	char 		*bat_stat;
1696
1697	/* 2002/08/01 - WT
1698	 * This is to avoid random crashes at boot time during initialization
1699	 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1700	 * Some bioses don't like being called from CPU != 0.
1701	 * Method suggested by Ingo Molnar.
1702	 */
1703	set_cpus_allowed_ptr(current, cpumask_of(0));
1704	BUG_ON(smp_processor_id() != 0);
1705
1706	if (apm_info.connection_version == 0) {
1707		apm_info.connection_version = apm_info.bios.version;
1708		if (apm_info.connection_version > 0x100) {
1709			/*
1710			 * We only support BIOSs up to version 1.2
1711			 */
1712			if (apm_info.connection_version > 0x0102)
1713				apm_info.connection_version = 0x0102;
1714			error = apm_driver_version(&apm_info.connection_version);
1715			if (error != APM_SUCCESS) {
1716				apm_error("driver version", error);
1717				/* Fall back to an APM 1.0 connection. */
1718				apm_info.connection_version = 0x100;
1719			}
1720		}
1721	}
1722
1723	if (debug)
1724		printk(KERN_INFO "apm: Connection version %d.%d\n",
1725			(apm_info.connection_version >> 8) & 0xff,
1726			apm_info.connection_version & 0xff);
1727
1728#ifdef CONFIG_APM_DO_ENABLE
1729	if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1730		/*
1731		 * This call causes my NEC UltraLite Versa 33/C to hang if it
1732		 * is booted with PM disabled but not in the docking station.
1733		 * Unfortunate ...
1734		 */
1735		error = apm_enable_power_management(1);
1736		if (error) {
1737			apm_error("enable power management", error);
1738			return -1;
1739		}
1740	}
1741#endif
1742
1743	if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1744	    && (apm_info.connection_version > 0x0100)) {
1745		error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1746		if (error) {
1747			apm_error("engage power management", error);
1748			return -1;
1749		}
1750	}
1751
1752	if (debug && (num_online_cpus() == 1 || smp)) {
1753		error = apm_get_power_status(&bx, &cx, &dx);
1754		if (error)
1755			printk(KERN_INFO "apm: power status not available\n");
1756		else {
1757			switch ((bx >> 8) & 0xff) {
1758			case 0:
1759				power_stat = "off line";
1760				break;
1761			case 1:
1762				power_stat = "on line";
1763				break;
1764			case 2:
1765				power_stat = "on backup power";
1766				break;
1767			default:
1768				power_stat = "unknown";
1769				break;
1770			}
1771			switch (bx & 0xff) {
1772			case 0:
1773				bat_stat = "high";
1774				break;
1775			case 1:
1776				bat_stat = "low";
1777				break;
1778			case 2:
1779				bat_stat = "critical";
1780				break;
1781			case 3:
1782				bat_stat = "charging";
1783				break;
1784			default:
1785				bat_stat = "unknown";
1786				break;
1787			}
1788			printk(KERN_INFO
1789			       "apm: AC %s, battery status %s, battery life ",
1790			       power_stat, bat_stat);
1791			if ((cx & 0xff) == 0xff)
1792				printk("unknown\n");
1793			else
1794				printk("%d%%\n", cx & 0xff);
1795			if (apm_info.connection_version > 0x100) {
1796				printk(KERN_INFO
1797				       "apm: battery flag 0x%02x, battery life ",
1798				       (cx >> 8) & 0xff);
1799				if (dx == 0xffff)
1800					printk("unknown\n");
1801				else
1802					printk("%d %s\n", dx & 0x7fff,
1803					       (dx & 0x8000) ?
1804					       "minutes" : "seconds");
1805			}
1806		}
1807	}
1808
1809	/* Install our power off handler.. */
1810	if (power_off)
1811		pm_power_off = apm_power_off;
1812
1813	if (num_online_cpus() == 1 || smp) {
1814#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1815		console_blank_hook = apm_console_blank;
1816#endif
1817		apm_mainloop();
1818#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1819		console_blank_hook = NULL;
1820#endif
1821	}
1822
1823	return 0;
1824}
1825
1826#ifndef MODULE
1827static int __init apm_setup(char *str)
1828{
1829	int invert;
1830
1831	while ((str != NULL) && (*str != '\0')) {
1832		if (strncmp(str, "off", 3) == 0)
1833			apm_disabled = 1;
1834		if (strncmp(str, "on", 2) == 0)
1835			apm_disabled = 0;
1836		if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1837		    (strncmp(str, "bounce_interval=", 16) == 0))
1838			bounce_interval = simple_strtol(str + 16, NULL, 0);
1839		if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1840		    (strncmp(str, "idle_threshold=", 15) == 0))
1841			idle_threshold = simple_strtol(str + 15, NULL, 0);
1842		if ((strncmp(str, "idle-period=", 12) == 0) ||
1843		    (strncmp(str, "idle_period=", 12) == 0))
1844			idle_period = simple_strtol(str + 12, NULL, 0);
1845		invert = (strncmp(str, "no-", 3) == 0) ||
1846			(strncmp(str, "no_", 3) == 0);
1847		if (invert)
1848			str += 3;
1849		if (strncmp(str, "debug", 5) == 0)
1850			debug = !invert;
1851		if ((strncmp(str, "power-off", 9) == 0) ||
1852		    (strncmp(str, "power_off", 9) == 0))
1853			power_off = !invert;
1854		if (strncmp(str, "smp", 3) == 0) {
1855			smp = !invert;
1856			idle_threshold = 100;
1857		}
1858		if ((strncmp(str, "allow-ints", 10) == 0) ||
1859		    (strncmp(str, "allow_ints", 10) == 0))
1860			apm_info.allow_ints = !invert;
1861		if ((strncmp(str, "broken-psr", 10) == 0) ||
1862		    (strncmp(str, "broken_psr", 10) == 0))
1863			apm_info.get_power_status_broken = !invert;
1864		if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1865		    (strncmp(str, "realmode_power_off", 18) == 0))
1866			apm_info.realmode_power_off = !invert;
1867		str = strchr(str, ',');
1868		if (str != NULL)
1869			str += strspn(str, ", \t");
1870	}
1871	return 1;
1872}
1873
1874__setup("apm=", apm_setup);
1875#endif
1876
1877static const struct file_operations apm_bios_fops = {
1878	.owner		= THIS_MODULE,
1879	.read		= do_read,
1880	.poll		= do_poll,
1881	.unlocked_ioctl	= do_ioctl,
1882	.open		= do_open,
1883	.release	= do_release,
1884	.llseek		= noop_llseek,
1885};
1886
1887static struct miscdevice apm_device = {
1888	APM_MINOR_DEV,
1889	"apm_bios",
1890	&apm_bios_fops
1891};
1892
1893
1894/* Simple "print if true" callback */
1895static int __init print_if_true(const struct dmi_system_id *d)
1896{
1897	printk("%s\n", d->ident);
1898	return 0;
1899}
1900
1901/*
1902 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1903 * disabled before the suspend. Linux used to get terribly confused by that.
1904 */
1905static int __init broken_ps2_resume(const struct dmi_system_id *d)
1906{
1907	printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1908	       "workaround hopefully not needed.\n", d->ident);
1909	return 0;
1910}
1911
1912/* Some bioses have a broken protected mode poweroff and need to use realmode */
1913static int __init set_realmode_power_off(const struct dmi_system_id *d)
1914{
1915	if (apm_info.realmode_power_off == 0) {
1916		apm_info.realmode_power_off = 1;
1917		printk(KERN_INFO "%s bios detected. "
1918		       "Using realmode poweroff only.\n", d->ident);
1919	}
1920	return 0;
1921}
1922
1923/* Some laptops require interrupts to be enabled during APM calls */
1924static int __init set_apm_ints(const struct dmi_system_id *d)
1925{
1926	if (apm_info.allow_ints == 0) {
1927		apm_info.allow_ints = 1;
1928		printk(KERN_INFO "%s machine detected. "
1929		       "Enabling interrupts during APM calls.\n", d->ident);
1930	}
1931	return 0;
1932}
1933
1934/* Some APM bioses corrupt memory or just plain do not work */
1935static int __init apm_is_horked(const struct dmi_system_id *d)
1936{
1937	if (apm_info.disabled == 0) {
1938		apm_info.disabled = 1;
1939		printk(KERN_INFO "%s machine detected. "
1940		       "Disabling APM.\n", d->ident);
1941	}
1942	return 0;
1943}
1944
1945static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1946{
1947	if (apm_info.disabled == 0) {
1948		apm_info.disabled = 1;
1949		printk(KERN_INFO "%s machine detected. "
1950		       "Disabling APM.\n", d->ident);
1951		printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1952		printk(KERN_INFO "download from support.intel.com\n");
1953	}
1954	return 0;
1955}
1956
1957/* Some APM bioses hang on APM idle calls */
1958static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1959{
1960	if (apm_info.forbid_idle == 0) {
1961		apm_info.forbid_idle = 1;
1962		printk(KERN_INFO "%s machine detected. "
1963		       "Disabling APM idle calls.\n", d->ident);
1964	}
1965	return 0;
1966}
1967
1968/*
1969 *  Check for clue free BIOS implementations who use
1970 *  the following QA technique
1971 *
1972 *      [ Write BIOS Code ]<------
1973 *               |                ^
1974 *      < Does it Compile >----N--
1975 *               |Y               ^
1976 *	< Does it Boot Win98 >-N--
1977 *               |Y
1978 *           [Ship It]
1979 *
1980 *	Phoenix A04  08/24/2000 is known bad (Dell Inspiron 5000e)
1981 *	Phoenix A07  09/29/2000 is known good (Dell Inspiron 5000)
1982 */
1983static int __init broken_apm_power(const struct dmi_system_id *d)
1984{
1985	apm_info.get_power_status_broken = 1;
1986	printk(KERN_WARNING "BIOS strings suggest APM bugs, "
1987	       "disabling power status reporting.\n");
1988	return 0;
1989}
1990
1991/*
1992 * This bios swaps the APM minute reporting bytes over (Many sony laptops
1993 * have this problem).
1994 */
1995static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
1996{
1997	apm_info.get_power_status_swabinminutes = 1;
1998	printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
1999	       "in minutes and wrong byte order.\n");
2000	return 0;
2001}
2002
2003static const struct dmi_system_id apm_dmi_table[] __initconst = {
2004	{
2005		print_if_true,
2006		KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2007		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2008			DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2009	},
2010	{	/* Handle problems with APM on the C600 */
2011		broken_ps2_resume, "Dell Latitude C600",
2012		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2013			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2014	},
2015	{	/* Allow interrupts during suspend on Dell Latitude laptops*/
2016		set_apm_ints, "Dell Latitude",
2017		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2018			DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2019	},
2020	{	/* APM crashes */
2021		apm_is_horked, "Dell Inspiron 2500",
2022		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2023			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2024			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2025			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2026	},
2027	{	/* Allow interrupts during suspend on Dell Inspiron laptops*/
2028		set_apm_ints, "Dell Inspiron", {
2029			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2030			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2031	},
2032	{	/* Handle problems with APM on Inspiron 5000e */
2033		broken_apm_power, "Dell Inspiron 5000e",
2034		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2035			DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2036			DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2037	},
2038	{	/* Handle problems with APM on Inspiron 2500 */
2039		broken_apm_power, "Dell Inspiron 2500",
2040		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2041			DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2042			DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2043	},
2044	{	/* APM crashes */
2045		apm_is_horked, "Dell Dimension 4100",
2046		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2047			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2048			DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2049			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2050	},
2051	{	/* Allow interrupts during suspend on Compaq Laptops*/
2052		set_apm_ints, "Compaq 12XL125",
2053		{	DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2054			DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2055			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2056			DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2057	},
2058	{	/* Allow interrupts during APM or the clock goes slow */
2059		set_apm_ints, "ASUSTeK",
2060		{	DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2061			DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2062	},
2063	{	/* APM blows on shutdown */
2064		apm_is_horked, "ABIT KX7-333[R]",
2065		{	DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2066			DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2067	},
2068	{	/* APM crashes */
2069		apm_is_horked, "Trigem Delhi3",
2070		{	DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2071			DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2072	},
2073	{	/* APM crashes */
2074		apm_is_horked, "Fujitsu-Siemens",
2075		{	DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2076			DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2077	},
2078	{	/* APM crashes */
2079		apm_is_horked_d850md, "Intel D850MD",
2080		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2081			DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2082	},
2083	{	/* APM crashes */
2084		apm_is_horked, "Intel D810EMO",
2085		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2086			DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2087	},
2088	{	/* APM crashes */
2089		apm_is_horked, "Dell XPS-Z",
2090		{	DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2091			DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2092			DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2093	},
2094	{	/* APM crashes */
2095		apm_is_horked, "Sharp PC-PJ/AX",
2096		{	DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2097			DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2098			DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2099			DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2100	},
2101	{	/* APM crashes */
2102		apm_is_horked, "Dell Inspiron 2500",
2103		{	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2104			DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2105			DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2106			DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2107	},
2108	{	/* APM idle hangs */
2109		apm_likes_to_melt, "Jabil AMD",
2110		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2111			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2112	},
2113	{	/* APM idle hangs */
2114		apm_likes_to_melt, "AMI Bios",
2115		{	DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2116			DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2117	},
2118	{	/* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2119		swab_apm_power_in_minutes, "Sony VAIO",
2120		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2121			DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2122			DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2123	},
2124	{	/* Handle problems with APM on Sony Vaio PCG-N505VX */
2125		swab_apm_power_in_minutes, "Sony VAIO",
2126		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2127			DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2128			DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2129	},
2130	{	/* Handle problems with APM on Sony Vaio PCG-XG29 */
2131		swab_apm_power_in_minutes, "Sony VAIO",
2132		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2133			DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2134			DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2135	},
2136	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2137		swab_apm_power_in_minutes, "Sony VAIO",
2138		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2139			DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2140			DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2141	},
2142	{	/* Handle problems with APM on Sony Vaio PCG-Z600NE */
2143		swab_apm_power_in_minutes, "Sony VAIO",
2144		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2145			DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2146			DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2147	},
2148	{	/* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2149		swab_apm_power_in_minutes, "Sony VAIO",
2150		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2151			DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2152			DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2153	},
2154	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2155		swab_apm_power_in_minutes, "Sony VAIO",
2156		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2157			DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2158			DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2159	},
2160	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS */
2161		swab_apm_power_in_minutes, "Sony VAIO",
2162		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2163			DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2164			DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2165	},
2166	{	/* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2167		swab_apm_power_in_minutes, "Sony VAIO",
2168		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2169			DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2170			DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2171	},
2172	{	/* Handle problems with APM on Sony Vaio PCG-F104K */
2173		swab_apm_power_in_minutes, "Sony VAIO",
2174		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2175			DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2176			DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2177	},
2178
2179	{	/* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2180		swab_apm_power_in_minutes, "Sony VAIO",
2181		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2182			DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2183			DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2184	},
2185	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2186		swab_apm_power_in_minutes, "Sony VAIO",
2187		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2188			DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2189			DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2190	},
2191	{	/* Handle problems with APM on Sony Vaio PCG-C1VE */
2192		swab_apm_power_in_minutes, "Sony VAIO",
2193		{	DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2194			DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2195			DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2196	},
2197	{	/* broken PM poweroff bios */
2198		set_realmode_power_off, "Award Software v4.60 PGMA",
2199		{	DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2200			DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2201			DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2202	},
2203
2204	/* Generic per vendor APM settings  */
2205
2206	{	/* Allow interrupts during suspend on IBM laptops */
2207		set_apm_ints, "IBM",
2208		{	DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2209	},
2210
2211	{ }
2212};
2213
2214/*
2215 * Just start the APM thread. We do NOT want to do APM BIOS
2216 * calls from anything but the APM thread, if for no other reason
2217 * than the fact that we don't trust the APM BIOS. This way,
2218 * most common APM BIOS problems that lead to protection errors
2219 * etc will have at least some level of being contained...
2220 *
2221 * In short, if something bad happens, at least we have a choice
2222 * of just killing the apm thread..
2223 */
2224static int __init apm_init(void)
2225{
2226	struct desc_struct *gdt;
2227	int err;
2228
2229	dmi_check_system(apm_dmi_table);
2230
2231	if (apm_info.bios.version == 0 || machine_is_olpc()) {
2232		printk(KERN_INFO "apm: BIOS not found.\n");
2233		return -ENODEV;
2234	}
2235	printk(KERN_INFO
2236	       "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2237	       ((apm_info.bios.version >> 8) & 0xff),
2238	       (apm_info.bios.version & 0xff),
2239	       apm_info.bios.flags,
2240	       driver_version);
2241	if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2242		printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2243		return -ENODEV;
2244	}
2245
2246	if (allow_ints)
2247		apm_info.allow_ints = 1;
2248	if (broken_psr)
2249		apm_info.get_power_status_broken = 1;
2250	if (realmode_power_off)
2251		apm_info.realmode_power_off = 1;
2252	/* User can override, but default is to trust DMI */
2253	if (apm_disabled != -1)
2254		apm_info.disabled = apm_disabled;
2255
2256	/*
2257	 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2258	 * but is reportedly a 1.0 BIOS.
2259	 */
2260	if (apm_info.bios.version == 0x001)
2261		apm_info.bios.version = 0x100;
2262
2263	/* BIOS < 1.2 doesn't set cseg_16_len */
2264	if (apm_info.bios.version < 0x102)
2265		apm_info.bios.cseg_16_len = 0; /* 64k */
2266
2267	if (debug) {
2268		printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2269			apm_info.bios.cseg, apm_info.bios.offset,
2270			apm_info.bios.cseg_16, apm_info.bios.dseg);
2271		if (apm_info.bios.version > 0x100)
2272			printk(" cseg len %x, dseg len %x",
2273				apm_info.bios.cseg_len,
2274				apm_info.bios.dseg_len);
2275		if (apm_info.bios.version > 0x101)
2276			printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2277		printk("\n");
2278	}
2279
2280	if (apm_info.disabled) {
2281		pr_notice("disabled on user request.\n");
2282		return -ENODEV;
2283	}
2284	if ((num_online_cpus() > 1) && !power_off && !smp) {
2285		pr_notice("disabled - APM is not SMP safe.\n");
2286		apm_info.disabled = 1;
2287		return -ENODEV;
2288	}
2289	if (!acpi_disabled) {
2290		pr_notice("overridden by ACPI.\n");
2291		apm_info.disabled = 1;
2292		return -ENODEV;
2293	}
2294
2295	/*
2296	 * Set up the long jump entry point to the APM BIOS, which is called
2297	 * from inline assembly.
2298	 */
2299	apm_bios_entry.offset = apm_info.bios.offset;
2300	apm_bios_entry.segment = APM_CS;
2301
2302	/*
2303	 * The APM 1.1 BIOS is supposed to provide limit information that it
2304	 * recognizes.  Many machines do this correctly, but many others do
2305	 * not restrict themselves to their claimed limit.  When this happens,
2306	 * they will cause a segmentation violation in the kernel at boot time.
2307	 * Most BIOS's, however, will respect a 64k limit, so we use that.
2308	 *
2309	 * Note we only set APM segments on CPU zero, since we pin the APM
2310	 * code to that CPU.
2311	 */
2312	gdt = get_cpu_gdt_rw(0);
2313	set_desc_base(&gdt[APM_CS >> 3],
2314		 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2315	set_desc_base(&gdt[APM_CS_16 >> 3],
2316		 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2317	set_desc_base(&gdt[APM_DS >> 3],
2318		 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2319
2320	proc_create_single("apm", 0, NULL, proc_apm_show);
2321
2322	kapmd_task = kthread_create(apm, NULL, "kapmd");
2323	if (IS_ERR(kapmd_task)) {
2324		pr_err("disabled - Unable to start kernel thread\n");
2325		err = PTR_ERR(kapmd_task);
2326		kapmd_task = NULL;
2327		remove_proc_entry("apm", NULL);
2328		return err;
2329	}
2330	wake_up_process(kapmd_task);
2331
2332	if (num_online_cpus() > 1 && !smp) {
2333		printk(KERN_NOTICE
2334		       "apm: disabled - APM is not SMP safe (power off active).\n");
2335		return 0;
2336	}
2337
2338	/*
2339	 * Note we don't actually care if the misc_device cannot be registered.
2340	 * this driver can do its job without it, even if userspace can't
2341	 * control it.  just log the error
2342	 */
2343	if (misc_register(&apm_device))
2344		printk(KERN_WARNING "apm: Could not register misc device.\n");
2345
2346	if (HZ != 100)
2347		idle_period = (idle_period * HZ) / 100;
2348	if (idle_threshold < 100) {
2349		cpuidle_poll_state_init(&apm_idle_driver);
2350		if (!cpuidle_register_driver(&apm_idle_driver))
2351			if (cpuidle_register_device(&apm_cpuidle_device))
2352				cpuidle_unregister_driver(&apm_idle_driver);
2353	}
2354
2355	return 0;
2356}
2357
2358static void __exit apm_exit(void)
2359{
2360	int error;
2361
2362	cpuidle_unregister_device(&apm_cpuidle_device);
2363	cpuidle_unregister_driver(&apm_idle_driver);
2364
2365	if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2366	    && (apm_info.connection_version > 0x0100)) {
2367		error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2368		if (error)
2369			apm_error("disengage power management", error);
2370	}
2371	misc_deregister(&apm_device);
2372	remove_proc_entry("apm", NULL);
2373	if (power_off)
2374		pm_power_off = NULL;
2375	if (kapmd_task) {
2376		kthread_stop(kapmd_task);
2377		kapmd_task = NULL;
2378	}
2379}
2380
2381module_init(apm_init);
2382module_exit(apm_exit);
2383
2384MODULE_AUTHOR("Stephen Rothwell");
2385MODULE_DESCRIPTION("Advanced Power Management");
2386MODULE_LICENSE("GPL");
2387module_param(debug, bool, 0644);
2388MODULE_PARM_DESC(debug, "Enable debug mode");
2389module_param(power_off, bool, 0444);
2390MODULE_PARM_DESC(power_off, "Enable power off");
2391module_param(bounce_interval, int, 0444);
2392MODULE_PARM_DESC(bounce_interval,
2393		"Set the number of ticks to ignore suspend bounces");
2394module_param(allow_ints, bool, 0444);
2395MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2396module_param(broken_psr, bool, 0444);
2397MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2398module_param(realmode_power_off, bool, 0444);
2399MODULE_PARM_DESC(realmode_power_off,
2400		"Switch to real mode before powering off");
2401module_param(idle_threshold, int, 0444);
2402MODULE_PARM_DESC(idle_threshold,
2403	"System idle percentage above which to make APM BIOS idle calls");
2404module_param(idle_period, int, 0444);
2405MODULE_PARM_DESC(idle_period,
2406	"Period (in sec/100) over which to calculate the idle percentage");
2407module_param(smp, bool, 0444);
2408MODULE_PARM_DESC(smp,
2409	"Set this to enable APM use on an SMP platform. Use with caution on older systems");
2410MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
2411