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PM / Hibernate: Fix s2disk regression related to freezing workqueues
[linux-block.git] / arch / x86 / kernel / apm_32.c
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1da177e4
LT		 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.
27b46d76 60 * The new replacement for it is, but Linux doesn't yet support this.
1da177e4
LT		 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
0d2eb44f 69 * 1.6: Cope with compiler/assembler differences.
1da177e4
LT		 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.
a2531293 143 * Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
1da177e4
LT		 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
87c6fe26 163 * broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
1da177e4 164 * 1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
87c6fe26 165 * calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
1da177e4
LT		 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
50a23e6e
JM		 192 * 916.356.6100) or 800.548.4725; or from
193 * http://www.microsoft.com/whdc/archive/amp_12.mspx It is also
1da177e4
LT		 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:
3f4b23e9 201 * http://www.microsoft.com/whdc/archive/amp_12.mspx]
1da177e4
LT		 202 */
203
1da177e4
LT		 204#include <linux/module.h>
205
206#include <linux/poll.h>
207#include <linux/types.h>
208#include <linux/stddef.h>
209#include <linux/timer.h>
210#include <linux/fcntl.h>
211#include <linux/slab.h>
212#include <linux/stat.h>
213#include <linux/proc_fs.h>
016d6f35 214#include <linux/seq_file.h>
1da177e4
LT		 215#include <linux/miscdevice.h>
216#include <linux/apm_bios.h>
217#include <linux/init.h>
218#include <linux/time.h>
219#include <linux/sched.h>
220#include <linux/pm.h>
a9415644 221#include <linux/capability.h>
1da177e4
LT		 222#include <linux/device.h>
223#include <linux/kernel.h>
83144186 224#include <linux/freezer.h>
1da177e4 225#include <linux/smp.h>
1da177e4
LT		 226#include <linux/dmi.h>
227#include <linux/suspend.h>
fc09561d 228#include <linux/kthread.h>
4f2479f0 229#include <linux/jiffies.h>
6831c6ed 230#include <linux/acpi.h>
19234c08 231#include <linux/syscore_ops.h>
334955ef 232#include <linux/i8253.h>
1da177e4
LT		 233
234#include <asm/system.h>
235#include <asm/uaccess.h>
236#include <asm/desc.h>
77a9a768 237#include <asm/olpc.h>
6020c8f3 238#include <asm/paravirt.h>
07f3331c 239#include <asm/reboot.h>
1da177e4 240
1da177e4
LT		 241#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
242extern int (*console_blank_hook)(int);
243#endif
244
245/*
246 * The apm_bios device is one of the misc char devices.
247 * This is its minor number.
248 */
249#define APM_MINOR_DEV 134
250
251/*
1da177e4
LT		 252 * Various options can be changed at boot time as follows:
253 * (We allow underscores for compatibility with the modules code)
254 * apm=on/off enable/disable APM
255 * [no-]allow[-_]ints allow interrupts during BIOS calls
256 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
257 * [no-]realmode[-_]power[-_]off switch to real mode before
258 * powering off
259 * [no-]debug log some debugging messages
260 * [no-]power[-_]off power off on shutdown
261 * [no-]smp Use apm even on an SMP box
262 * bounce[-_]interval=<n> number of ticks to ignore suspend
263 * bounces
264 * idle[-_]threshold=<n> System idle percentage above which to
265 * make APM BIOS idle calls. Set it to
266 * 100 to disable.
267 * idle[-_]period=<n> Period (in 1/100s of a second) over
268 * which the idle percentage is
269 * calculated.
270 */
271
272/* KNOWN PROBLEM MACHINES:
273 *
274 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
275 * [Confirmed by TI representative]
276 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
277 * [Confirmed by BIOS disassembly]
278 * [This may work now ...]
279 * P: Toshiba 1950S: battery life information only gets updated after resume
280 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
281 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
282 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
283 * Neale Banks <neale@lowendale.com.au> December 2000
284 *
285 * Legend: U = unusable with APM patches
286 * P = partially usable with APM patches
287 */
288
289/*
290 * Define as 1 to make the driver always call the APM BIOS busy
291 * routine even if the clock was not reported as slowed by the
292 * idle routine. Otherwise, define as 0.
293 */
294#define ALWAYS_CALL_BUSY 1
295
296/*
297 * Define to make the APM BIOS calls zero all data segment registers (so
298 * that an incorrect BIOS implementation will cause a kernel panic if it
299 * tries to write to arbitrary memory).
300 */
301#define APM_ZERO_SEGS
302
1164dd00 303#include <asm/apm.h>
1da177e4 304
1da177e4
LT		 305/*
306 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
307 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
308 * David Chen <chen@ctpa04.mit.edu>
309 */
310#undef INIT_TIMER_AFTER_SUSPEND
311
312#ifdef INIT_TIMER_AFTER_SUSPEND
313#include <linux/timex.h>
314#include <asm/io.h>
315#include <linux/delay.h>
316#endif
317
318/*
319 * Need to poll the APM BIOS every second
320 */
321#define APM_CHECK_TIMEOUT (HZ)
322
323/*
324 * Ignore suspend events for this amount of time after a resume
325 */
3f4380a1 326#define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
1da177e4
LT		 327
328/*
329 * Maximum number of events stored
330 */
331#define APM_MAX_EVENTS 20
332
333/*
334 * The per-file APM data
335 */
336struct apm_user {
337 int magic;
3f4380a1 338 struct apm_user *next;
77617bd8
DP		 339 unsigned int suser: 1;
340 unsigned int writer: 1;
341 unsigned int reader: 1;
342 unsigned int suspend_wait: 1;
1da177e4
LT		 343 int suspend_result;
344 int suspends_pending;
345 int standbys_pending;
346 int suspends_read;
347 int standbys_read;
348 int event_head;
349 int event_tail;
350 apm_event_t events[APM_MAX_EVENTS];
351};
352
353/*
354 * The magic number in apm_user
355 */
356#define APM_BIOS_MAGIC 0x4101
357
358/*
359 * idle percentage above which bios idle calls are done
360 */
361#ifdef CONFIG_APM_CPU_IDLE
99c63221 362#warning deprecated CONFIG_APM_CPU_IDLE will be deleted in 2012
1da177e4
LT		 363#define DEFAULT_IDLE_THRESHOLD 95
364#else
365#define DEFAULT_IDLE_THRESHOLD 100
366#endif
367#define DEFAULT_IDLE_PERIOD (100 / 3)
368
369/*
370 * Local variables
371 */
372static struct {
373 unsigned long offset;
374 unsigned short segment;
3f4380a1
CG		 375} apm_bios_entry;
376static int clock_slowed;
377static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
378static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
379static int set_pm_idle;
380static int suspends_pending;
381static int standbys_pending;
382static int ignore_sys_suspend;
383static int ignore_normal_resume;
384static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
385
476bc001
RR		 386static bool debug __read_mostly;
387static bool smp __read_mostly;
3f4380a1 388static int apm_disabled = -1;
1da177e4 389#ifdef CONFIG_SMP
476bc001 390static bool power_off;
1da177e4 391#else
476bc001 392static bool power_off = 1;
1da177e4 393#endif
476bc001 394static bool realmode_power_off;
1da177e4 395#ifdef CONFIG_APM_ALLOW_INTS
476bc001 396static bool allow_ints = 1;
1da177e4 397#else
476bc001 398static bool allow_ints;
1da177e4 399#endif
476bc001 400static bool broken_psr;
1da177e4
LT		 401
402static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
403static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
3f4380a1 404static struct apm_user *user_list;
1da177e4 405static DEFINE_SPINLOCK(user_list_lock);
05d86412 406static DEFINE_MUTEX(apm_mutex);
c7425314
AM		 407
408/*
409 * Set up a segment that references the real mode segment 0x40
410 * that extends up to the end of page zero (that we have reserved).
411 * This is for buggy BIOS's that refer to (real mode) segment 0x40
412 * even though they are called in protected mode.
413 */
414static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
415 (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
1da177e4 416
3f4380a1 417static const char driver_version[] = "1.16ac"; /* no spaces */
1da177e4 418
fc09561d
SH		 419static struct task_struct *kapmd_task;
420
1da177e4
LT		 421/*
422 * APM event names taken from the APM 1.2 specification. These are
423 * the message codes that the BIOS uses to tell us about events
424 */
3f4380a1 425static const char * const apm_event_name[] = {
1da177e4
LT		 426 "system standby",
427 "system suspend",
428 "normal resume",
429 "critical resume",
430 "low battery",
431 "power status change",
432 "update time",
433 "critical suspend",
434 "user standby",
435 "user suspend",
436 "system standby resume",
437 "capabilities change"
438};
38e548ee 439#define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
1da177e4
LT		 440
441typedef struct lookup_t {
442 int key;
3f4380a1 443 char *msg;
1da177e4
LT		 444} lookup_t;
445
446/*
447 * The BIOS returns a set of standard error codes in AX when the
448 * carry flag is set.
449 */
3f4380a1 450
1da177e4
LT		 451static const lookup_t error_table[] = {
452/* N/A { APM_SUCCESS, "Operation succeeded" }, */
453 { APM_DISABLED, "Power management disabled" },
454 { APM_CONNECTED, "Real mode interface already connected" },
455 { APM_NOT_CONNECTED, "Interface not connected" },
456 { APM_16_CONNECTED, "16 bit interface already connected" },
457/* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
458 { APM_32_CONNECTED, "32 bit interface already connected" },
459 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
460 { APM_BAD_DEVICE, "Unrecognized device ID" },
461 { APM_BAD_PARAM, "Parameter out of range" },
462 { APM_NOT_ENGAGED, "Interface not engaged" },
463 { APM_BAD_FUNCTION, "Function not supported" },
464 { APM_RESUME_DISABLED, "Resume timer disabled" },
465 { APM_BAD_STATE, "Unable to enter requested state" },
466/* N/A { APM_NO_EVENTS, "No events pending" }, */
467 { APM_NO_ERROR, "BIOS did not set a return code" },
468 { APM_NOT_PRESENT, "No APM present" }
469};
38e548ee 470#define ERROR_COUNT ARRAY_SIZE(error_table)
1da177e4
LT		 471
472/**
473 * apm_error - display an APM error
474 * @str: information string
475 * @err: APM BIOS return code
476 *
477 * Write a meaningful log entry to the kernel log in the event of
89bd55d1 478 * an APM error. Note that this also handles (negative) kernel errors.
1da177e4 479 */
3f4380a1 480
1da177e4
LT		 481static void apm_error(char *str, int err)
482{
3f4380a1 483 int i;
1da177e4
LT		 484
485 for (i = 0; i < ERROR_COUNT; i++)
3f4380a1
CG		 486 if (error_table[i].key == err)
487 break;
1da177e4
LT		 488 if (i < ERROR_COUNT)
489 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
89bd55d1
RR		 490 else if (err < 0)
491 printk(KERN_NOTICE "apm: %s: linux error code %i\n", str, err);
1da177e4
LT		 492 else
493 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
3f4380a1 494 str, err);
1da177e4
LT		 495}
496
1da177e4
LT		 497/*
498 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
499 * apm_info.allow_ints, we are being really paranoid here! Not only
500 * are interrupts disabled, but all the segment registers (except SS)
501 * are saved and zeroed this means that if the BIOS tries to reference
502 * any data without explicitly loading the segment registers, the kernel
503 * will fault immediately rather than have some unforeseen circumstances
504 * for the rest of the kernel. And it will be very obvious! :-) Doing
505 * this depends on CS referring to the same physical memory as DS so that
506 * DS can be zeroed before the call. Unfortunately, we can't do anything
507 * about the stack segment/pointer. Also, we tell the compiler that
508 * everything could change.
509 *
510 * Also, we KNOW that for the non error case of apm_bios_call, there
511 * is no useful data returned in the low order 8 bits of eax.
512 */
3864c489
PZ		 513
514static inline unsigned long __apm_irq_save(void)
515{
516 unsigned long flags;
517 local_save_flags(flags);
518 if (apm_info.allow_ints) {
519 if (irqs_disabled_flags(flags))
520 local_irq_enable();
521 } else
522 local_irq_disable();
523
524 return flags;
525}
526
527#define apm_irq_save(flags) \
528 do { flags = __apm_irq_save(); } while (0)
529
530static inline void apm_irq_restore(unsigned long flags)
531{
532 if (irqs_disabled_flags(flags))
1da177e4 533 local_irq_disable();
3864c489
PZ		 534 else if (irqs_disabled())
535 local_irq_enable();
536}
1da177e4
LT		 537
538#ifdef APM_ZERO_SEGS
539# define APM_DECL_SEGS \
540 unsigned int saved_fs; unsigned int saved_gs;
541# define APM_DO_SAVE_SEGS \
542 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
543# define APM_DO_RESTORE_SEGS \
544 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
545#else
546# define APM_DECL_SEGS
547# define APM_DO_SAVE_SEGS
548# define APM_DO_RESTORE_SEGS
549#endif
550
89bd55d1
RR		 551struct apm_bios_call {
552 u32 func;
553 /* In and out */
554 u32 ebx;
555 u32 ecx;
556 /* Out only */
557 u32 eax;
558 u32 edx;
559 u32 esi;
560
561 /* Error: -ENOMEM, or bits 8-15 of eax */
562 int err;
563};
564
1da177e4 565/**
89bd55d1
RR		 566 * __apm_bios_call - Make an APM BIOS 32bit call
567 * @_call: pointer to struct apm_bios_call.
1da177e4
LT		 568 *
569 * Make an APM call using the 32bit protected mode interface. The
570 * caller is responsible for knowing if APM BIOS is configured and
571 * enabled. This call can disable interrupts for a long period of
572 * time on some laptops. The return value is in AH and the carry
573 * flag is loaded into AL. If there is an error, then the error
574 * code is returned in AH (bits 8-15 of eax) and this function
575 * returns non-zero.
89bd55d1
RR		 576 *
577 * Note: this makes the call on the current CPU.
1da177e4 578 */
89bd55d1 579static long __apm_bios_call(void *_call)
1da177e4
LT		 580{
581 APM_DECL_SEGS
582 unsigned long flags;
1da177e4
LT		 583 int cpu;
584 struct desc_struct save_desc_40;
251e6912 585 struct desc_struct *gdt;
89bd55d1 586 struct apm_bios_call *call = _call;
3f4380a1 587
1da177e4 588 cpu = get_cpu();
89bd55d1 589 BUG_ON(cpu != 0);
251e6912
ZA		 590 gdt = get_cpu_gdt_table(cpu);
591 save_desc_40 = gdt[0x40 / 8];
592 gdt[0x40 / 8] = bad_bios_desc;
1da177e4 593
3864c489 594 apm_irq_save(flags);
1da177e4 595 APM_DO_SAVE_SEGS;
89bd55d1
RR		 596 apm_bios_call_asm(call->func, call->ebx, call->ecx,
597 &call->eax, &call->ebx, &call->ecx, &call->edx,
598 &call->esi);
1da177e4 599 APM_DO_RESTORE_SEGS;
3864c489 600 apm_irq_restore(flags);
251e6912 601 gdt[0x40 / 8] = save_desc_40;
1da177e4 602 put_cpu();
3f4380a1 603
89bd55d1
RR		 604 return call->eax & 0xff;
605}
606
607/* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
608static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
609{
610 int ret;
611
612 /* Don't bother with work_on_cpu in the common case, so we don't
613 * have to worry about OOM or overhead. */
614 if (get_cpu() == 0) {
615 ret = fn(call);
616 put_cpu();
617 } else {
618 put_cpu();
619 ret = work_on_cpu(0, fn, call);
620 }
621
622 /* work_on_cpu can fail with -ENOMEM */
623 if (ret < 0)
624 call->err = ret;
625 else
626 call->err = (call->eax >> 8) & 0xff;
627
628 return ret;
1da177e4
LT		 629}
630
631/**
89bd55d1
RR		 632 * apm_bios_call - Make an APM BIOS 32bit call (on CPU 0)
633 * @call: the apm_bios_call registers.
634 *
635 * If there is an error, it is returned in @call.err.
636 */
637static int apm_bios_call(struct apm_bios_call *call)
638{
639 return on_cpu0(__apm_bios_call, call);
640}
641
642/**
643 * __apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
644 * @_call: pointer to struct apm_bios_call.
1da177e4 645 *
87af2ffd 646 * Make a BIOS call that returns one value only, or just status.
1da177e4 647 * If there is an error, then the error code is returned in AH
89bd55d1
RR		 648 * (bits 8-15 of eax) and this function returns non-zero (it can
649 * also return -ENOMEM). This is used for simpler BIOS operations.
650 * This call may hold interrupts off for a long time on some laptops.
651 *
652 * Note: this makes the call on the current CPU.
1da177e4 653 */
89bd55d1 654static long __apm_bios_call_simple(void *_call)
1da177e4
LT		 655{
656 u8 error;
657 APM_DECL_SEGS
658 unsigned long flags;
1da177e4
LT		 659 int cpu;
660 struct desc_struct save_desc_40;
251e6912 661 struct desc_struct *gdt;
89bd55d1 662 struct apm_bios_call *call = _call;
3f4380a1 663
1da177e4 664 cpu = get_cpu();
89bd55d1 665 BUG_ON(cpu != 0);
251e6912
ZA		 666 gdt = get_cpu_gdt_table(cpu);
667 save_desc_40 = gdt[0x40 / 8];
668 gdt[0x40 / 8] = bad_bios_desc;
1da177e4 669
3864c489 670 apm_irq_save(flags);
1da177e4 671 APM_DO_SAVE_SEGS;
89bd55d1
RR		 672 error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
673 &call->eax);
1da177e4 674 APM_DO_RESTORE_SEGS;
3864c489 675 apm_irq_restore(flags);
251e6912 676 gdt[0x40 / 8] = save_desc_40;
1da177e4 677 put_cpu();
1da177e4
LT		 678 return error;
679}
680
89bd55d1
RR		 681/**
682 * apm_bios_call_simple - make a simple APM BIOS 32bit call
683 * @func: APM function to invoke
684 * @ebx_in: EBX register value for BIOS call
685 * @ecx_in: ECX register value for BIOS call
686 * @eax: EAX register on return from the BIOS call
687 * @err: bits
688 *
689 * Make a BIOS call that returns one value only, or just status.
690 * If there is an error, then the error code is returned in @err
691 * and this function returns non-zero. This is used for simpler
692 * BIOS operations. This call may hold interrupts off for a long
693 * time on some laptops.
694 */
695static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
696 int *err)
697{
698 struct apm_bios_call call;
699 int ret;
700
701 call.func = func;
702 call.ebx = ebx_in;
703 call.ecx = ecx_in;
704
705 ret = on_cpu0(__apm_bios_call_simple, &call);
706 *eax = call.eax;
707 *err = call.err;
708 return ret;
709}
710
1da177e4
LT		 711/**
712 * apm_driver_version - APM driver version
713 * @val: loaded with the APM version on return
714 *
715 * Retrieve the APM version supported by the BIOS. This is only
716 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
717 * probably present.
718 *
719 * On entry val should point to a value indicating the APM driver
720 * version with the high byte being the major and the low byte the
721 * minor number both in BCD
722 *
723 * On return it will hold the BIOS revision supported in the
724 * same format.
725 */
726
727static int apm_driver_version(u_short *val)
728{
3f4380a1 729 u32 eax;
89bd55d1 730 int err;
1da177e4 731
89bd55d1
RR		 732 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
733 return err;
1da177e4
LT		 734 *val = eax;
735 return APM_SUCCESS;
736}
737
738/**
739 * apm_get_event - get an APM event from the BIOS
740 * @event: pointer to the event
741 * @info: point to the event information
742 *
743 * The APM BIOS provides a polled information for event
744 * reporting. The BIOS expects to be polled at least every second
745 * when events are pending. When a message is found the caller should
746 * poll until no more messages are present. However, this causes
747 * problems on some laptops where a suspend event notification is
748 * not cleared until it is acknowledged.
749 *
750 * Additional information is returned in the info pointer, providing
751 * that APM 1.2 is in use. If no messges are pending the value 0x80
752 * is returned (No power management events pending).
753 */
1da177e4
LT		 754static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
755{
89bd55d1 756 struct apm_bios_call call;
1da177e4 757
89bd55d1
RR		 758 call.func = APM_FUNC_GET_EVENT;
759 call.ebx = call.ecx = 0;
760
761 if (apm_bios_call(&call))
762 return call.err;
763
764 *event = call.ebx;
1da177e4
LT		 765 if (apm_info.connection_version < 0x0102)
766 *info = ~0; /* indicate info not valid */
767 else
89bd55d1 768 *info = call.ecx;
1da177e4
LT		 769 return APM_SUCCESS;
770}
771
772/**
773 * set_power_state - set the power management state
774 * @what: which items to transition
775 * @state: state to transition to
776 *
777 * Request an APM change of state for one or more system devices. The
778 * processor state must be transitioned last of all. what holds the
779 * class of device in the upper byte and the device number (0xFF for
780 * all) for the object to be transitioned.
781 *
782 * The state holds the state to transition to, which may in fact
783 * be an acceptance of a BIOS requested state change.
784 */
3f4380a1 785
1da177e4
LT		 786static int set_power_state(u_short what, u_short state)
787{
3f4380a1 788 u32 eax;
89bd55d1 789 int err;
1da177e4 790
89bd55d1
RR		 791 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
792 return err;
1da177e4
LT		 793 return APM_SUCCESS;
794}
795
796/**
797 * set_system_power_state - set system wide power state
798 * @state: which state to enter
799 *
800 * Transition the entire system into a new APM power state.
801 */
3f4380a1 802
1da177e4
LT		 803static int set_system_power_state(u_short state)
804{
805 return set_power_state(APM_DEVICE_ALL, state);
806}
807
808/**
809 * apm_do_idle - perform power saving
810 *
811 * This function notifies the BIOS that the processor is (in the view
812 * of the OS) idle. It returns -1 in the event that the BIOS refuses
813 * to handle the idle request. On a success the function returns 1
814 * if the BIOS did clock slowing or 0 otherwise.
815 */
3f4380a1 816
1da177e4
LT		 817static int apm_do_idle(void)
818{
3f4380a1
CG		 819 u32 eax;
820 u8 ret = 0;
821 int idled = 0;
822 int polling;
dc731fbb 823 int err = 0;
64c7c8f8 824
495ab9c0 825 polling = !!(current_thread_info()->status & TS_POLLING);
64c7c8f8 826 if (polling) {
495ab9c0 827 current_thread_info()->status &= ~TS_POLLING;
0888f06a
IM		 828 /*
829 * TS_POLLING-cleared state must be visible before we
830 * test NEED_RESCHED:
831 */
832 smp_mb();
64c7c8f8
NP		 833 }
834 if (!need_resched()) {
835 idled = 1;
89bd55d1 836 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
64c7c8f8
NP		 837 }
838 if (polling)
495ab9c0 839 current_thread_info()->status |= TS_POLLING;
64c7c8f8
NP		 840
841 if (!idled)
842 return 0;
843
844 if (ret) {
1da177e4
LT		 845 static unsigned long t;
846
847 /* This always fails on some SMP boards running UP kernels.
848 * Only report the failure the first 5 times.
849 */
3f4380a1 850 if (++t < 5) {
89bd55d1 851 printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
1da177e4
LT		 852 t = jiffies;
853 }
854 return -1;
855 }
856 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
857 return clock_slowed;
858}
859
860/**
861 * apm_do_busy - inform the BIOS the CPU is busy
862 *
3f4380a1 863 * Request that the BIOS brings the CPU back to full performance.
1da177e4 864 */
3f4380a1 865
1da177e4
LT		 866static void apm_do_busy(void)
867{
3f4380a1 868 u32 dummy;
89bd55d1 869 int err;
1da177e4
LT		 870
871 if (clock_slowed || ALWAYS_CALL_BUSY) {
89bd55d1 872 (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
1da177e4
LT		 873 clock_slowed = 0;
874 }
875}
876
877/*
878 * If no process has really been interested in
879 * the CPU for some time, we want to call BIOS
880 * power management - we probably want
881 * to conserve power.
882 */
3f4380a1
CG		 883#define IDLE_CALC_LIMIT (HZ * 100)
884#define IDLE_LEAKY_MAX 16
1da177e4 885
87af2ffd 886static void (*original_pm_idle)(void) __read_mostly;
1da177e4 887
1da177e4
LT		 888/**
889 * apm_cpu_idle - cpu idling for APM capable Linux
890 *
3f4380a1 891 * This is the idling function the kernel executes when APM is available. It
1da177e4
LT		 892 * tries to do BIOS powermanagement based on the average system idle time.
893 * Furthermore it calls the system default idle routine.
894 */
895
896static void apm_cpu_idle(void)
897{
898 static int use_apm_idle; /* = 0 */
899 static unsigned int last_jiffies; /* = 0 */
900 static unsigned int last_stime; /* = 0 */
901
902 int apm_idle_done = 0;
903 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
904 unsigned int bucket;
905
99c63221 906 WARN_ONCE(1, "deprecated apm_cpu_idle will be deleted in 2012");
1da177e4
LT		 907recalc:
908 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
909 use_apm_idle = 0;
910 last_jiffies = jiffies;
911 last_stime = current->stime;
912 } else if (jiffies_since_last_check > idle_period) {
913 unsigned int idle_percentage;
914
915 idle_percentage = current->stime - last_stime;
916 idle_percentage *= 100;
917 idle_percentage /= jiffies_since_last_check;
918 use_apm_idle = (idle_percentage > idle_threshold);
919 if (apm_info.forbid_idle)
920 use_apm_idle = 0;
921 last_jiffies = jiffies;
922 last_stime = current->stime;
923 }
924
925 bucket = IDLE_LEAKY_MAX;
926
927 while (!need_resched()) {
928 if (use_apm_idle) {
929 unsigned int t;
930
931 t = jiffies;
932 switch (apm_do_idle()) {
3f4380a1
CG		 933 case 0:
934 apm_idle_done = 1;
1da177e4
LT		 935 if (t != jiffies) {
936 if (bucket) {
937 bucket = IDLE_LEAKY_MAX;
938 continue;
939 }
940 } else if (bucket) {
941 bucket--;
942 continue;
943 }
944 break;
3f4380a1
CG		 945 case 1:
946 apm_idle_done = 1;
1da177e4
LT		 947 break;
948 default: /* BIOS refused */
949 break;
950 }
951 }
952 if (original_pm_idle)
953 original_pm_idle();
954 else
955 default_idle();
7f424a8b 956 local_irq_disable();
1da177e4
LT		 957 jiffies_since_last_check = jiffies - last_jiffies;
958 if (jiffies_since_last_check > idle_period)
959 goto recalc;
960 }
961
962 if (apm_idle_done)
963 apm_do_busy();
7f424a8b
PZ		 964
965 local_irq_enable();
1da177e4
LT		 966}
967
968/**
969 * apm_power_off - ask the BIOS to power off
970 *
971 * Handle the power off sequence. This is the one piece of code we
972 * will execute even on SMP machines. In order to deal with BIOS
973 * bugs we support real mode APM BIOS power off calls. We also make
974 * the SMP call on CPU0 as some systems will only honour this call
975 * on their first cpu.
976 */
3f4380a1 977
1da177e4
LT		 978static void apm_power_off(void)
979{
1da177e4 980 /* Some bioses don't like being called from CPU != 0 */
3f4380a1 981 if (apm_info.realmode_power_off) {
89bd55d1 982 set_cpus_allowed_ptr(current, cpumask_of(0));
3d35ac34 983 machine_real_restart(MRR_APM);
3f4380a1
CG		 984 } else {
985 (void)set_system_power_state(APM_STATE_OFF);
1da177e4 986 }
1da177e4
LT		 987}
988
989#ifdef CONFIG_APM_DO_ENABLE
990
991/**
992 * apm_enable_power_management - enable BIOS APM power management
993 * @enable: enable yes/no
994 *
3f4380a1 995 * Enable or disable the APM BIOS power services.
1da177e4 996 */
3f4380a1 997
1da177e4
LT		 998static int apm_enable_power_management(int enable)
999{
3f4380a1 1000 u32 eax;
89bd55d1 1001 int err;
1da177e4
LT		 1002
1003 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1004 return APM_NOT_ENGAGED;
1005 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
89bd55d1
RR		 1006 enable, &eax, &err))
1007 return err;
1da177e4
LT		 1008 if (enable)
1009 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1010 else
1011 apm_info.bios.flags |= APM_BIOS_DISABLED;
1012 return APM_SUCCESS;
1013}
1014#endif
1015
1016/**
1017 * apm_get_power_status - get current power state
1018 * @status: returned status
1019 * @bat: battery info
1020 * @life: estimated life
1021 *
1022 * Obtain the current power status from the APM BIOS. We return a
1023 * status which gives the rough battery status, and current power
1024 * source. The bat value returned give an estimate as a percentage
1025 * of life and a status value for the battery. The estimated life
1026 * if reported is a lifetime in secodnds/minutes at current powwer
1027 * consumption.
1028 */
3f4380a1 1029
1da177e4
LT		 1030static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1031{
89bd55d1
RR		 1032 struct apm_bios_call call;
1033
1034 call.func = APM_FUNC_GET_STATUS;
1035 call.ebx = APM_DEVICE_ALL;
1036 call.ecx = 0;
1da177e4
LT		 1037
1038 if (apm_info.get_power_status_broken)
1039 return APM_32_UNSUPPORTED;
89bd55d1
RR		 1040 if (apm_bios_call(&call))
1041 return call.err;
1042 *status = call.ebx;
1043 *bat = call.ecx;
1da177e4 1044 if (apm_info.get_power_status_swabinminutes) {
89bd55d1 1045 *life = swab16((u16)call.edx);
1da177e4
LT		 1046 *life |= 0x8000;
1047 } else
89bd55d1 1048 *life = call.edx;
1da177e4
LT		 1049 return APM_SUCCESS;
1050}
1051
1052#if 0
1053static int apm_get_battery_status(u_short which, u_short *status,
1054 u_short *bat, u_short *life, u_short *nbat)
1055{
3f4380a1
CG		 1056 u32 eax;
1057 u32 ebx;
1058 u32 ecx;
1059 u32 edx;
1060 u32 esi;
1da177e4
LT		 1061
1062 if (apm_info.connection_version < 0x0102) {
1063 /* pretend we only have one battery. */
1064 if (which != 1)
1065 return APM_BAD_DEVICE;
1066 *nbat = 1;
1067 return apm_get_power_status(status, bat, life);
1068 }
1069
1070 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
3f4380a1 1071 &ebx, &ecx, &edx, &esi))
1da177e4
LT		 1072 return (eax >> 8) & 0xff;
1073 *status = ebx;
1074 *bat = ecx;
1075 *life = edx;
1076 *nbat = esi;
1077 return APM_SUCCESS;
1078}
1079#endif
1080
1081/**
1082 * apm_engage_power_management - enable PM on a device
1083 * @device: identity of device
1084 * @enable: on/off
1085 *
1086 * Activate or deactive power management on either a specific device
1087 * or the entire system (%APM_DEVICE_ALL).
1088 */
3f4380a1 1089
1da177e4
LT		 1090static int apm_engage_power_management(u_short device, int enable)
1091{
3f4380a1 1092 u32 eax;
89bd55d1 1093 int err;
1da177e4
LT		 1094
1095 if ((enable == 0) && (device == APM_DEVICE_ALL)
1096 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1097 return APM_DISABLED;
89bd55d1
RR		 1098 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1099 &eax, &err))
1100 return err;
1da177e4
LT		 1101 if (device == APM_DEVICE_ALL) {
1102 if (enable)
1103 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1104 else
1105 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1106 }
1107 return APM_SUCCESS;
1108}
1109
1110#if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1111
1112/**
1113 * apm_console_blank - blank the display
1114 * @blank: on/off
1115 *
1116 * Attempt to blank the console, firstly by blanking just video device
1117 * zero, and if that fails (some BIOSes don't support it) then it blanks
1118 * all video devices. Typically the BIOS will do laptop backlight and
1119 * monitor powerdown for us.
1120 */
3f4380a1 1121
1da177e4
LT		 1122static int apm_console_blank(int blank)
1123{
87af2ffd
AM		 1124 int error = APM_NOT_ENGAGED; /* silence gcc */
1125 int i;
3841b0a1
JC		 1126 u_short state;
1127 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1da177e4
LT		 1128
1129 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
3841b0a1
JC		 1130
1131 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1132 error = set_power_state(dev[i], state);
1133
1134 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1135 return 1;
1136
1137 if (error == APM_NOT_ENGAGED)
1138 break;
1da177e4 1139 }
3841b0a1 1140
73374454 1141 if (error == APM_NOT_ENGAGED) {
1da177e4
LT		 1142 static int tried;
1143 int eng_error;
1144 if (tried++ == 0) {
1145 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1146 if (eng_error) {
1147 apm_error("set display", error);
1148 apm_error("engage interface", eng_error);
1149 return 0;
1150 } else
1151 return apm_console_blank(blank);
1152 }
1153 }
1154 apm_error("set display", error);
1155 return 0;
1156}
1157#endif
1158
1159static int queue_empty(struct apm_user *as)
1160{
1161 return as->event_head == as->event_tail;
1162}
1163
1164static apm_event_t get_queued_event(struct apm_user *as)
1165{
87af2ffd
AM		 1166 if (++as->event_tail >= APM_MAX_EVENTS)
1167 as->event_tail = 0;
1da177e4
LT		 1168 return as->events[as->event_tail];
1169}
1170
1171static void queue_event(apm_event_t event, struct apm_user *sender)
1172{
3f4380a1 1173 struct apm_user *as;
1da177e4
LT		 1174
1175 spin_lock(&user_list_lock);
1176 if (user_list == NULL)
1177 goto out;
1178 for (as = user_list; as != NULL; as = as->next) {
1179 if ((as == sender) || (!as->reader))
1180 continue;
87af2ffd
AM		 1181 if (++as->event_head >= APM_MAX_EVENTS)
1182 as->event_head = 0;
1183
1da177e4
LT		 1184 if (as->event_head == as->event_tail) {
1185 static int notified;
1186
1187 if (notified++ == 0)
1188 printk(KERN_ERR "apm: an event queue overflowed\n");
87af2ffd
AM		 1189 if (++as->event_tail >= APM_MAX_EVENTS)
1190 as->event_tail = 0;
1da177e4
LT		 1191 }
1192 as->events[as->event_head] = event;
b764a15f 1193 if (!as->suser || !as->writer)
1da177e4
LT		 1194 continue;
1195 switch (event) {
1196 case APM_SYS_SUSPEND:
1197 case APM_USER_SUSPEND:
1198 as->suspends_pending++;
1199 suspends_pending++;
1200 break;
1201
1202 case APM_SYS_STANDBY:
1203 case APM_USER_STANDBY:
1204 as->standbys_pending++;
1205 standbys_pending++;
1206 break;
1207 }
1208 }
1209 wake_up_interruptible(&apm_waitqueue);
1210out:
1211 spin_unlock(&user_list_lock);
1212}
1213
1da177e4
LT		 1214static void reinit_timer(void)
1215{
1216#ifdef INIT_TIMER_AFTER_SUSPEND
306e440d 1217 unsigned long flags;
1da177e4 1218
ced918eb 1219 raw_spin_lock_irqsave(&i8253_lock, flags);
c9919380 1220 /* set the clock to HZ */
01898e3e 1221 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1da177e4 1222 udelay(10);
01898e3e 1223 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1da177e4 1224 udelay(10);
01898e3e 1225 outb_p(LATCH >> 8, PIT_CH0); /* MSB */
1da177e4 1226 udelay(10);
ced918eb 1227 raw_spin_unlock_irqrestore(&i8253_lock, flags);
1da177e4
LT		 1228#endif
1229}
1230
1231static int suspend(int vetoable)
1232{
3f4380a1 1233 int err;
1da177e4
LT		 1234 struct apm_user *as;
1235
d1616302 1236 dpm_suspend_start(PMSG_SUSPEND);
2ed8d2b3 1237
d1616302 1238 dpm_suspend_noirq(PMSG_SUSPEND);
2ed8d2b3
RW		 1239
1240 local_irq_disable();
19234c08 1241 syscore_suspend();
1da177e4 1242
1da177e4
LT		 1243 local_irq_enable();
1244
1245 save_processor_state();
1246 err = set_system_power_state(APM_STATE_SUSPEND);
92c6dc59 1247 ignore_normal_resume = 1;
1da177e4
LT		 1248 restore_processor_state();
1249
1250 local_irq_disable();
c7f40ff1 1251 reinit_timer();
1da177e4
LT		 1252
1253 if (err == APM_NO_ERROR)
1254 err = APM_SUCCESS;
1255 if (err != APM_SUCCESS)
1256 apm_error("suspend", err);
1257 err = (err == APM_SUCCESS) ? 0 : -EIO;
2ed8d2b3 1258
19234c08 1259 syscore_resume();
1da177e4 1260 local_irq_enable();
2ed8d2b3 1261
d1616302 1262 dpm_resume_noirq(PMSG_RESUME);
2ed8d2b3 1263
d1616302 1264 dpm_resume_end(PMSG_RESUME);
1da177e4 1265 queue_event(APM_NORMAL_RESUME, NULL);
1da177e4
LT		 1266 spin_lock(&user_list_lock);
1267 for (as = user_list; as != NULL; as = as->next) {
1268 as->suspend_wait = 0;
1269 as->suspend_result = err;
1270 }
1271 spin_unlock(&user_list_lock);
1272 wake_up_interruptible(&apm_suspend_waitqueue);
1273 return err;
1274}
1275
1276static void standby(void)
1277{
3f4380a1 1278 int err;
1da177e4 1279
d1616302 1280 dpm_suspend_noirq(PMSG_SUSPEND);
2ed8d2b3
RW		 1281
1282 local_irq_disable();
19234c08 1283 syscore_suspend();
1da177e4
LT		 1284 local_irq_enable();
1285
1286 err = set_system_power_state(APM_STATE_STANDBY);
1287 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1288 apm_error("standby", err);
1289
1290 local_irq_disable();
19234c08 1291 syscore_resume();
1da177e4 1292 local_irq_enable();
2ed8d2b3 1293
d1616302 1294 dpm_resume_noirq(PMSG_RESUME);
1da177e4
LT		 1295}
1296
1297static apm_event_t get_event(void)
1298{
3f4380a1
CG		 1299 int error;
1300 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1da177e4
LT		 1301 apm_eventinfo_t info;
1302
1303 static int notified;
1304
1305 /* we don't use the eventinfo */
1306 error = apm_get_event(&event, &info);
1307 if (error == APM_SUCCESS)
1308 return event;
1309
1310 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1311 apm_error("get_event", error);
1312
1313 return 0;
1314}
1315
1316static void check_events(void)
1317{
3f4380a1
CG		 1318 apm_event_t event;
1319 static unsigned long last_resume;
1320 static int ignore_bounce;
1da177e4
LT		 1321
1322 while ((event = get_event()) != 0) {
1323 if (debug) {
1324 if (event <= NR_APM_EVENT_NAME)
1325 printk(KERN_DEBUG "apm: received %s notify\n",
1326 apm_event_name[event - 1]);
1327 else
1328 printk(KERN_DEBUG "apm: received unknown "
1329 "event 0x%02x\n", event);
1330 }
1331 if (ignore_bounce
4f2479f0 1332 && (time_after(jiffies, last_resume + bounce_interval)))
1da177e4
LT		 1333 ignore_bounce = 0;
1334
1335 switch (event) {
1336 case APM_SYS_STANDBY:
1337 case APM_USER_STANDBY:
1338 queue_event(event, NULL);
1339 if (standbys_pending <= 0)
1340 standby();
1341 break;
1342
1343 case APM_USER_SUSPEND:
1344#ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1345 if (apm_info.connection_version > 0x100)
1346 set_system_power_state(APM_STATE_REJECT);
1347 break;
1348#endif
1349 case APM_SYS_SUSPEND:
1350 if (ignore_bounce) {
1351 if (apm_info.connection_version > 0x100)
1352 set_system_power_state(APM_STATE_REJECT);
1353 break;
1354 }
1355 /*
1356 * If we are already processing a SUSPEND,
1357 * then further SUSPEND events from the BIOS
1358 * will be ignored. We also return here to
1359 * cope with the fact that the Thinkpads keep
1360 * sending a SUSPEND event until something else
1361 * happens!
1362 */
1363 if (ignore_sys_suspend)
1364 return;
1365 ignore_sys_suspend = 1;
1366 queue_event(event, NULL);
1367 if (suspends_pending <= 0)
1368 (void) suspend(1);
1369 break;
1370
1371 case APM_NORMAL_RESUME:
1372 case APM_CRITICAL_RESUME:
1373 case APM_STANDBY_RESUME:
1374 ignore_sys_suspend = 0;
1375 last_resume = jiffies;
1376 ignore_bounce = 1;
1377 if ((event != APM_NORMAL_RESUME)
1378 || (ignore_normal_resume == 0)) {
d1616302 1379 dpm_resume_end(PMSG_RESUME);
1da177e4
LT		 1380 queue_event(event, NULL);
1381 }
1382 ignore_normal_resume = 0;
1383 break;
1384
1385 case APM_CAPABILITY_CHANGE:
1386 case APM_LOW_BATTERY:
1387 case APM_POWER_STATUS_CHANGE:
1388 queue_event(event, NULL);
1389 /* If needed, notify drivers here */
1390 break;
1391
1392 case APM_UPDATE_TIME:
1da177e4
LT		 1393 break;
1394
1395 case APM_CRITICAL_SUSPEND:
1396 /*
1397 * We are not allowed to reject a critical suspend.
1398 */
3f4380a1 1399 (void)suspend(0);
1da177e4
LT		 1400 break;
1401 }
1402 }
1403}
1404
1405static void apm_event_handler(void)
1406{
3f4380a1
CG		 1407 static int pending_count = 4;
1408 int err;
1da177e4
LT		 1409
1410 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1411 if ((apm_info.connection_version > 0x100) &&
3f4380a1 1412 (pending_count-- <= 0)) {
1da177e4
LT		 1413 pending_count = 4;
1414 if (debug)
1415 printk(KERN_DEBUG "apm: setting state busy\n");
1416 err = set_system_power_state(APM_STATE_BUSY);
1417 if (err)
1418 apm_error("busy", err);
1419 }
1420 } else
1421 pending_count = 4;
1422 check_events();
1423}
1424
1425/*
1426 * This is the APM thread main loop.
1427 */
1428
1429static void apm_mainloop(void)
1430{
1431 DECLARE_WAITQUEUE(wait, current);
1432
1433 add_wait_queue(&apm_waitqueue, &wait);
1434 set_current_state(TASK_INTERRUPTIBLE);
1435 for (;;) {
1436 schedule_timeout(APM_CHECK_TIMEOUT);
fc09561d 1437 if (kthread_should_stop())
1da177e4
LT		 1438 break;
1439 /*
1440 * Ok, check all events, check for idle (and mark us sleeping
1441 * so as not to count towards the load average)..
1442 */
1443 set_current_state(TASK_INTERRUPTIBLE);
1444 apm_event_handler();
1445 }
1446 remove_wait_queue(&apm_waitqueue, &wait);
1447}
1448
1449static int check_apm_user(struct apm_user *as, const char *func)
1450{
b764a15f 1451 if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1da177e4
LT		 1452 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1453 return 1;
1454 }
1455 return 0;
1456}
1457
1458static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1459{
3f4380a1
CG		 1460 struct apm_user *as;
1461 int i;
1462 apm_event_t event;
1da177e4
LT		 1463
1464 as = fp->private_data;
1465 if (check_apm_user(as, "read"))
1466 return -EIO;
1467 if ((int)count < sizeof(apm_event_t))
1468 return -EINVAL;
1469 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1470 return -EAGAIN;
1471 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1472 i = count;
1473 while ((i >= sizeof(event)) && !queue_empty(as)) {
1474 event = get_queued_event(as);
1475 if (copy_to_user(buf, &event, sizeof(event))) {
1476 if (i < count)
1477 break;
1478 return -EFAULT;
1479 }
1480 switch (event) {
1481 case APM_SYS_SUSPEND:
1482 case APM_USER_SUSPEND:
1483 as->suspends_read++;
1484 break;
1485
1486 case APM_SYS_STANDBY:
1487 case APM_USER_STANDBY:
1488 as->standbys_read++;
1489 break;
1490 }
1491 buf += sizeof(event);
1492 i -= sizeof(event);
1493 }
1494 if (i < count)
1495 return count - i;
1496 if (signal_pending(current))
1497 return -ERESTARTSYS;
1498 return 0;
1499}
1500
3f4380a1 1501static unsigned int do_poll(struct file *fp, poll_table *wait)
1da177e4 1502{
3f4380a1 1503 struct apm_user *as;
1da177e4
LT		 1504
1505 as = fp->private_data;
1506 if (check_apm_user(as, "poll"))
1507 return 0;
1508 poll_wait(fp, &apm_waitqueue, wait);
1509 if (!queue_empty(as))
1510 return POLLIN | POLLRDNORM;
1511 return 0;
1512}
1513
b764a15f 1514static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1da177e4 1515{
3f4380a1 1516 struct apm_user *as;
b764a15f 1517 int ret;
1da177e4
LT		 1518
1519 as = filp->private_data;
1520 if (check_apm_user(as, "ioctl"))
1521 return -EIO;
b764a15f 1522 if (!as->suser || !as->writer)
1da177e4
LT		 1523 return -EPERM;
1524 switch (cmd) {
1525 case APM_IOC_STANDBY:
05d86412 1526 mutex_lock(&apm_mutex);
1da177e4
LT		 1527 if (as->standbys_read > 0) {
1528 as->standbys_read--;
1529 as->standbys_pending--;
1530 standbys_pending--;
1531 } else
1532 queue_event(APM_USER_STANDBY, as);
1533 if (standbys_pending <= 0)
1534 standby();
05d86412 1535 mutex_unlock(&apm_mutex);
1da177e4
LT		 1536 break;
1537 case APM_IOC_SUSPEND:
05d86412 1538 mutex_lock(&apm_mutex);
1da177e4
LT		 1539 if (as->suspends_read > 0) {
1540 as->suspends_read--;
1541 as->suspends_pending--;
1542 suspends_pending--;
1543 } else
1544 queue_event(APM_USER_SUSPEND, as);
1545 if (suspends_pending <= 0) {
b764a15f 1546 ret = suspend(1);
05d86412 1547 mutex_unlock(&apm_mutex);
1da177e4
LT		 1548 } else {
1549 as->suspend_wait = 1;
05d86412 1550 mutex_unlock(&apm_mutex);
1da177e4
LT		 1551 wait_event_interruptible(apm_suspend_waitqueue,
1552 as->suspend_wait == 0);
b764a15f 1553 ret = as->suspend_result;
1da177e4 1554 }
b764a15f 1555 return ret;
1da177e4 1556 default:
b764a15f 1557 return -ENOTTY;
1da177e4
LT		 1558 }
1559 return 0;
1560}
1561
3f4380a1 1562static int do_release(struct inode *inode, struct file *filp)
1da177e4 1563{
3f4380a1 1564 struct apm_user *as;
1da177e4
LT		 1565
1566 as = filp->private_data;
1567 if (check_apm_user(as, "release"))
1568 return 0;
1569 filp->private_data = NULL;
1570 if (as->standbys_pending > 0) {
1571 standbys_pending -= as->standbys_pending;
1572 if (standbys_pending <= 0)
1573 standby();
1574 }
1575 if (as->suspends_pending > 0) {
1576 suspends_pending -= as->suspends_pending;
1577 if (suspends_pending <= 0)
1578 (void) suspend(1);
1579 }
3f4380a1 1580 spin_lock(&user_list_lock);
1da177e4
LT		 1581 if (user_list == as)
1582 user_list = as->next;
1583 else {
3f4380a1 1584 struct apm_user *as1;
1da177e4
LT		 1585
1586 for (as1 = user_list;
1587 (as1 != NULL) && (as1->next != as);
1588 as1 = as1->next)
1589 ;
1590 if (as1 == NULL)
1591 printk(KERN_ERR "apm: filp not in user list\n");
1592 else
1593 as1->next = as->next;
1594 }
1595 spin_unlock(&user_list_lock);
1596 kfree(as);
1597 return 0;
1598}
1599
3f4380a1 1600static int do_open(struct inode *inode, struct file *filp)
1da177e4 1601{
3f4380a1 1602 struct apm_user *as;
1da177e4 1603
5cbded58 1604 as = kmalloc(sizeof(*as), GFP_KERNEL);
1da177e4
LT		 1605 if (as == NULL) {
1606 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1607 sizeof(*as));
1608 return -ENOMEM;
1609 }
1610 as->magic = APM_BIOS_MAGIC;
1611 as->event_tail = as->event_head = 0;
1612 as->suspends_pending = as->standbys_pending = 0;
1613 as->suspends_read = as->standbys_read = 0;
1614 /*
1615 * XXX - this is a tiny bit broken, when we consider BSD
3f4380a1 1616 * process accounting. If the device is opened by root, we
1da177e4
LT		 1617 * instantly flag that we used superuser privs. Who knows,
1618 * we might close the device immediately without doing a
1619 * privileged operation -- cevans
1620 */
1621 as->suser = capable(CAP_SYS_ADMIN);
1622 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1623 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1624 spin_lock(&user_list_lock);
1625 as->next = user_list;
1626 user_list = as;
1627 spin_unlock(&user_list_lock);
1628 filp->private_data = as;
1629 return 0;
1630}
1631
016d6f35 1632static int proc_apm_show(struct seq_file *m, void *v)
1da177e4 1633{
1da177e4
LT		 1634 unsigned short bx;
1635 unsigned short cx;
1636 unsigned short dx;
1637 int error;
1638 unsigned short ac_line_status = 0xff;
1639 unsigned short battery_status = 0xff;
1640 unsigned short battery_flag = 0xff;
1641 int percentage = -1;
1642 int time_units = -1;
1643 char *units = "?";
1644
1da177e4
LT		 1645 if ((num_online_cpus() == 1) &&
1646 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1647 ac_line_status = (bx >> 8) & 0xff;
1648 battery_status = bx & 0xff;
1649 if ((cx & 0xff) != 0xff)
1650 percentage = cx & 0xff;
1651
1652 if (apm_info.connection_version > 0x100) {
1653 battery_flag = (cx >> 8) & 0xff;
1654 if (dx != 0xffff) {
1655 units = (dx & 0x8000) ? "min" : "sec";
1656 time_units = dx & 0x7fff;
1657 }
1658 }
1659 }
1660 /* Arguments, with symbols from linux/apm_bios.h. Information is
1661 from the Get Power Status (0x0a) call unless otherwise noted.
1662
1663 0) Linux driver version (this will change if format changes)
1664 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1665 2) APM flags from APM Installation Check (0x00):
1666 bit 0: APM_16_BIT_SUPPORT
1667 bit 1: APM_32_BIT_SUPPORT
1668 bit 2: APM_IDLE_SLOWS_CLOCK
1669 bit 3: APM_BIOS_DISABLED
1670 bit 4: APM_BIOS_DISENGAGED
1671 3) AC line status
1672 0x00: Off-line
1673 0x01: On-line
1674 0x02: On backup power (BIOS >= 1.1 only)
1675 0xff: Unknown
1676 4) Battery status
1677 0x00: High
1678 0x01: Low
1679 0x02: Critical
1680 0x03: Charging
1681 0x04: Selected battery not present (BIOS >= 1.2 only)
1682 0xff: Unknown
1683 5) Battery flag
1684 bit 0: High
1685 bit 1: Low
1686 bit 2: Critical
1687 bit 3: Charging
1688 bit 7: No system battery
1689 0xff: Unknown
1690 6) Remaining battery life (percentage of charge):
1691 0-100: valid
1692 -1: Unknown
1693 7) Remaining battery life (time units):
1694 Number of remaining minutes or seconds
1695 -1: Unknown
1696 8) min = minutes; sec = seconds */
1697
016d6f35 1698 seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
3f4380a1
CG		 1699 driver_version,
1700 (apm_info.bios.version >> 8) & 0xff,
1701 apm_info.bios.version & 0xff,
1702 apm_info.bios.flags,
1703 ac_line_status,
1704 battery_status,
1705 battery_flag,
1706 percentage,
1707 time_units,
1708 units);
016d6f35
AD		 1709 return 0;
1710}
1da177e4 1711
016d6f35
AD		 1712static int proc_apm_open(struct inode *inode, struct file *file)
1713{
1714 return single_open(file, proc_apm_show, NULL);
1da177e4
LT		 1715}
1716
016d6f35
AD		 1717static const struct file_operations apm_file_ops = {
1718 .owner = THIS_MODULE,
1719 .open = proc_apm_open,
1720 .read = seq_read,
1721 .llseek = seq_lseek,
1722 .release = single_release,
1723};
1724
1da177e4
LT		 1725static int apm(void *unused)
1726{
1727 unsigned short bx;
1728 unsigned short cx;
1729 unsigned short dx;
1730 int error;
3f4380a1
CG		 1731 char *power_stat;
1732 char *bat_stat;
1da177e4 1733
1da177e4
LT		 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 */
89bd55d1 1740 set_cpus_allowed_ptr(current, cpumask_of(0));
1da177e4 1741 BUG_ON(smp_processor_id() != 0);
1da177e4
LT		 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
3f4380a1 1789 if (debug && (num_online_cpus() == 1 || smp)) {
1da177e4
LT		 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) {
3f4380a1
CG		 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;
1da177e4
LT		 1807 }
1808 switch (bx & 0xff) {
3f4380a1
CG		 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;
1da177e4
LT		 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,
3f4380a1
CG		 1840 (dx & 0x8000) ?
1841 "minutes" : "seconds");
1da177e4
LT		 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 }
1da177e4
LT		 1859
1860 return 0;
1861}
1862
1863#ifndef MODULE
1864static int __init apm_setup(char *str)
1865{
3f4380a1 1866 int invert;
1da177e4
LT		 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;
3f4380a1 1891 if (strncmp(str, "smp", 3) == 0) {
1da177e4
LT		 1892 smp = !invert;
1893 idle_threshold = 100;
1894 }
1895 if ((strncmp(str, "allow-ints", 10) == 0) ||
1896 (strncmp(str, "allow_ints", 10) == 0))
3f4380a1 1897 apm_info.allow_ints = !invert;
1da177e4
LT		 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
5dfe4c96 1914static const struct file_operations apm_bios_fops = {
1da177e4
LT		 1915 .owner = THIS_MODULE,
1916 .read = do_read,
1917 .poll = do_poll,
b764a15f 1918 .unlocked_ioctl = do_ioctl,
1da177e4
LT		 1919 .open = do_open,
1920 .release = do_release,
6038f373 1921 .llseek = noop_llseek,
1da177e4
LT		 1922};
1923
1924static struct miscdevice apm_device = {
1925 APM_MINOR_DEV,
1926 "apm_bios",
1927 &apm_bios_fops
1928};
1929
1930
1931/* Simple "print if true" callback */
1855256c 1932static int __init print_if_true(const struct dmi_system_id *d)
1da177e4
LT		 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 */
1855256c 1942static int __init broken_ps2_resume(const struct dmi_system_id *d)
1da177e4 1943{
3f4380a1
CG		 1944 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1945 "workaround hopefully not needed.\n", d->ident);
1da177e4
LT		 1946 return 0;
1947}
1948
1949/* Some bioses have a broken protected mode poweroff and need to use realmode */
1855256c 1950static int __init set_realmode_power_off(const struct dmi_system_id *d)
1da177e4
LT		 1951{
1952 if (apm_info.realmode_power_off == 0) {
1953 apm_info.realmode_power_off = 1;
3f4380a1
CG		 1954 printk(KERN_INFO "%s bios detected. "
1955 "Using realmode poweroff only.\n", d->ident);
1da177e4
LT		 1956 }
1957 return 0;
1958}
1959
1960/* Some laptops require interrupts to be enabled during APM calls */
1855256c 1961static int __init set_apm_ints(const struct dmi_system_id *d)
1da177e4
LT		 1962{
1963 if (apm_info.allow_ints == 0) {
1964 apm_info.allow_ints = 1;
3f4380a1
CG		 1965 printk(KERN_INFO "%s machine detected. "
1966 "Enabling interrupts during APM calls.\n", d->ident);
1da177e4
LT		 1967 }
1968 return 0;
1969}
1970
1971/* Some APM bioses corrupt memory or just plain do not work */
1855256c 1972static int __init apm_is_horked(const struct dmi_system_id *d)
1da177e4
LT		 1973{
1974 if (apm_info.disabled == 0) {
1975 apm_info.disabled = 1;
3f4380a1
CG		 1976 printk(KERN_INFO "%s machine detected. "
1977 "Disabling APM.\n", d->ident);
1da177e4
LT		 1978 }
1979 return 0;
1980}
1981
1855256c 1982static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1da177e4
LT		 1983{
1984 if (apm_info.disabled == 0) {
1985 apm_info.disabled = 1;
3f4380a1
CG		 1986 printk(KERN_INFO "%s machine detected. "
1987 "Disabling APM.\n", d->ident);
3235dc3f
FP		 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");
1da177e4
LT		 1990 }
1991 return 0;
1992}
1993
1994/* Some APM bioses hang on APM idle calls */
1855256c 1995static int __init apm_likes_to_melt(const struct dmi_system_id *d)
1da177e4
LT		 1996{
1997 if (apm_info.forbid_idle == 0) {
1998 apm_info.forbid_idle = 1;
3f4380a1
CG		 1999 printk(KERN_INFO "%s machine detected. "
2000 "Disabling APM idle calls.\n", d->ident);
1da177e4
LT		 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 */
1855256c 2020static int __init broken_apm_power(const struct dmi_system_id *d)
1da177e4
LT		 2021{
2022 apm_info.get_power_status_broken = 1;
3f4380a1
CG		 2023 printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2024 "disabling power status reporting.\n");
1da177e4
LT		 2025 return 0;
2026}
2027
2028/*
2029 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2030 * have this problem).
2031 */
1855256c 2032static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
1da177e4
LT		 2033{
2034 apm_info.get_power_status_swabinminutes = 1;
3f4380a1
CG		 2035 printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2036 "in minutes and wrong byte order.\n");
1da177e4
LT		 2037 return 0;
2038}
2039
2040static struct dmi_system_id __initdata apm_dmi_table[] = {
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"),
3f4380a1
CG		 2061 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2062 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
1da177e4
LT		 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"),
3f4380a1
CG		 2085 DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2086 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
1da177e4
LT		 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"),
3f4380a1 2093 DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
1da177e4
LT		 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"),
3f4380a1
CG		 2135 DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2136 DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
1da177e4
LT		 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"),
3f4380a1
CG		 2142 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2143 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
1da177e4
LT		 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 */
2261static int __init apm_init(void)
2262{
92f17f01 2263 struct desc_struct *gdt;
fc09561d 2264 int err;
1da177e4
LT		 2265
2266 dmi_check_system(apm_dmi_table);
2267
77a9a768 2268 if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
1da177e4
LT		 2269 printk(KERN_INFO "apm: BIOS not found.\n");
2270 return -ENODEV;
2271 }
2272 printk(KERN_INFO
3f4380a1
CG		 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);
1da177e4
LT		 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) {
07a30460 2305 printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
1da177e4
LT		 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 printk(KERN_NOTICE "apm: disabled on user request.\n");
2319 return -ENODEV;
2320 }
2321 if ((num_online_cpus() > 1) && !power_off && !smp) {
2322 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2323 apm_info.disabled = 1;
2324 return -ENODEV;
2325 }
6831c6ed 2326 if (!acpi_disabled) {
1da177e4
LT		 2327 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2328 apm_info.disabled = 1;
2329 return -ENODEV;
2330 }
1da177e4 2331
3012d2d2
ZA		 2332 /*
2333 * Set up the long jump entry point to the APM BIOS, which is called
2334 * from inline assembly.
2335 */
1da177e4
LT		 2336 apm_bios_entry.offset = apm_info.bios.offset;
2337 apm_bios_entry.segment = APM_CS;
2338
3012d2d2
ZA		 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.
92f17f01
ZA		 2345 *
2346 * Note we only set APM segments on CPU zero, since we pin the APM
2347 * code to that CPU.
3012d2d2 2348 */
92f17f01 2349 gdt = get_cpu_gdt_table(0);
57594742
AM		 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));
1da177e4 2356
11ae9dd4 2357 proc_create("apm", 0, NULL, &apm_file_ops);
1da177e4 2358
fc09561d
SH		 2359 kapmd_task = kthread_create(apm, NULL, "kapmd");
2360 if (IS_ERR(kapmd_task)) {
2361 printk(KERN_ERR "apm: disabled - Unable to start kernel "
2362 "thread.\n");
2363 err = PTR_ERR(kapmd_task);
2364 kapmd_task = NULL;
c94a62aa 2365 remove_proc_entry("apm", NULL);
fc09561d 2366 return err;
1da177e4 2367 }
fc09561d 2368 wake_up_process(kapmd_task);
1da177e4 2369
3f4380a1 2370 if (num_online_cpus() > 1 && !smp) {
1da177e4 2371 printk(KERN_NOTICE
3f4380a1 2372 "apm: disabled - APM is not SMP safe (power off active).\n");
1da177e4
LT		 2373 return 0;
2374 }
2375
c94a62aa
NH		 2376 /*
2377 * Note we don't actually care if the misc_device cannot be registered.
2378 * this driver can do its job without it, even if userspace can't
2379 * control it. just log the error
2380 */
2381 if (misc_register(&apm_device))
2382 printk(KERN_WARNING "apm: Could not register misc device.\n");
1da177e4
LT		 2383
2384 if (HZ != 100)
2385 idle_period = (idle_period * HZ) / 100;
2386 if (idle_threshold < 100) {
2387 original_pm_idle = pm_idle;
2388 pm_idle = apm_cpu_idle;
2389 set_pm_idle = 1;
2390 }
2391
2392 return 0;
2393}
2394
2395static void __exit apm_exit(void)
2396{
3f4380a1 2397 int error;
1da177e4
LT		 2398
2399 if (set_pm_idle) {
2400 pm_idle = original_pm_idle;
2401 /*
2402 * We are about to unload the current idle thread pm callback
2403 * (pm_idle), Wait for all processors to update cached/local
2404 * copies of pm_idle before proceeding.
2405 */
2406 cpu_idle_wait();
2407 }
2408 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2409 && (apm_info.connection_version > 0x0100)) {
2410 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2411 if (error)
2412 apm_error("disengage power management", error);
2413 }
2414 misc_deregister(&apm_device);
2415 remove_proc_entry("apm", NULL);
2416 if (power_off)
2417 pm_power_off = NULL;
fc09561d
SH		 2418 if (kapmd_task) {
2419 kthread_stop(kapmd_task);
2420 kapmd_task = NULL;
2421 }
1da177e4
LT		 2422}
2423
2424module_init(apm_init);
2425module_exit(apm_exit);
2426
2427MODULE_AUTHOR("Stephen Rothwell");
2428MODULE_DESCRIPTION("Advanced Power Management");
2429MODULE_LICENSE("GPL");
2430module_param(debug, bool, 0644);
2431MODULE_PARM_DESC(debug, "Enable debug mode");
2432module_param(power_off, bool, 0444);
2433MODULE_PARM_DESC(power_off, "Enable power off");
2434module_param(bounce_interval, int, 0444);
2435MODULE_PARM_DESC(bounce_interval,
2436 "Set the number of ticks to ignore suspend bounces");
2437module_param(allow_ints, bool, 0444);
2438MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2439module_param(broken_psr, bool, 0444);
2440MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2441module_param(realmode_power_off, bool, 0444);
2442MODULE_PARM_DESC(realmode_power_off,
2443 "Switch to real mode before powering off");
2444module_param(idle_threshold, int, 0444);
2445MODULE_PARM_DESC(idle_threshold,
2446 "System idle percentage above which to make APM BIOS idle calls");
2447module_param(idle_period, int, 0444);
2448MODULE_PARM_DESC(idle_period,
2449 "Period (in sec/100) over which to caculate the idle percentage");
2450module_param(smp, bool, 0444);
2451MODULE_PARM_DESC(smp,
2452 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2453MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);
Linux 6.x block layer and io_uring tree(s)