2 * APM BIOS driver for Linux
3 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
5 * Initial development of this driver was funded by NEC Australia P/L
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
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.
18 * October 1995, Rik Faith (faith@cs.unc.edu):
19 * Minor enhancements and updates (to the patch set) for 1.3.x
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)
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
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,
52 * 1.1: support user-space standby and suspend, power off after system
53 * halted, Linux 1.3.98
54 * 1.2: When resetting RTC after resume, take care so that the time
55 * is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
56 * <jtoth@princeton.edu>); improve interaction between
57 * screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
58 * 1.2a:Simple change to stop mysterious bug reports with SMP also added
59 * levels to the printk calls. APM is not defined for SMP machines.
60 * The new replacement for it is, but Linux doesn't yet support this.
61 * Alan Cox Linux 2.1.55
62 * 1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
63 * 1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
64 * Dean Gaudet <dgaudet@arctic.org>.
65 * C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
66 * 1.5: Fix segment register reloading (in case of bad segments saved
69 * 1.6: Cope with compiler/assembler differences.
70 * Only try to turn off the first display device.
71 * Fix OOPS at power off with no APM BIOS by Jan Echternach
72 * <echter@informatik.uni-rostock.de>
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
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
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.
101 * 1.10: Fix for Thinkpad return code.
102 * Merge 2.2 and 2.3 drivers.
103 * Remove APM dependencies in arch/i386/kernel/process.c
104 * Remove APM dependencies in drivers/char/sysrq.c
105 * Reset time across standby.
106 * Allow more inititialisation on SMP.
107 * Remove CONFIG_APM_POWER_OFF and make it boot time
108 * configurable (default on).
109 * Make debug only a boot time parameter (remove APM_DEBUG).
110 * Try to blank all devices on any error.
111 * 1.11: Remove APM dependencies in drivers/char/console.c
112 * Check nr_running to detect if we are idle (from
113 * Borislav Deianov <borislav@lix.polytechnique.fr>)
114 * Fix for bioses that don't zero the top part of the
115 * entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
116 * (reported by Panos Katsaloulis <teras@writeme.com>).
117 * Real mode power off patch (Walter Hofmann
118 * <Walter.Hofmann@physik.stud.uni-erlangen.de>).
119 * 1.12: Remove CONFIG_SMP as the compiler will optimize
120 * the code away anyway (smp_num_cpus == 1 in UP)
121 * noted by Artur Skawina <skawina@geocities.com>.
122 * Make power off under SMP work again.
123 * Fix thinko with initial engaging of BIOS.
124 * Make sure power off only happens on CPU 0
125 * (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
126 * Do error notification to user mode if BIOS calls fail.
127 * Move entrypoint offset fix to ...boot/setup.S
128 * where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
129 * Remove smp-power-off. SMP users must now specify
130 * "apm=power-off" on the kernel command line. Suggested
131 * by Jim Avera <jima@hal.com>, modified by Alan Cox
132 * <alan@lxorguk.ukuu.org.uk>.
133 * Register the /proc/apm entry even on SMP so that
134 * scripts that check for it before doing power off
135 * work (Jim Avera <jima@hal.com>).
136 * 1.13: Changes for new pm_ interfaces (Andy Henroid
137 * <andy_henroid@yahoo.com>).
138 * Modularize the code.
139 * Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
140 * is now the way life works).
141 * Fix thinko in suspend() (wrong return).
142 * Notify drivers on critical suspend.
143 * Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
145 * Disable interrupts while we are suspended (Andy Henroid
146 * <andy_henroid@yahoo.com> fixed by sfr).
147 * Make power off work on SMP again (Tony Hoyle
148 * <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
149 * Remove CONFIG_APM_SUSPEND_BOUNCE. The bounce ignore
150 * interval is now configurable.
151 * 1.14: Make connection version persist across module unload/load.
152 * Enable and engage power management earlier.
153 * Disengage power management on module unload.
154 * Changed to use the sysrq-register hack for registering the
155 * power off function called by magic sysrq based upon discussions
156 * in irc://irc.openprojects.net/#kernelnewbies
157 * (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
158 * Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
159 * (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
160 * Work around byte swap bug in one of the Vaio's BIOS's
161 * (Marc Boucher <marc@mbsi.ca>).
162 * Exposed the disable flag to dmi so that we can handle known
163 * broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
164 * 1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
165 * calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
166 * If an APM idle fails log it and idle sensibly
167 * 1.15: Don't queue events to clients who open the device O_WRONLY.
168 * Don't expect replies from clients who open the device O_RDONLY.
169 * (Idea from Thomas Hood)
170 * Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
171 * 1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
172 * Notify listeners of standby or suspend events before notifying
173 * drivers. Return EBUSY to ioctl() if suspend is rejected.
174 * (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
175 * Ignore first resume after we generate our own resume event
176 * after a suspend (Thomas Hood)
177 * Daemonize now gets rid of our controlling terminal (sfr).
178 * CONFIG_APM_CPU_IDLE now just affects the default value of
179 * idle_threshold (sfr).
180 * Change name of kernel apm daemon (as it no longer idles) (sfr).
181 * 1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
182 * make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
183 * TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
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.
191 * [This document is available free from Intel by calling 800.628.8686 (fax
192 * 916.356.6100) or 800.548.4725; or from
193 * http://www.microsoft.com/whdc/archive/amp_12.mspx It is also
194 * available from Microsoft by calling 206.882.8080.]
197 * Intel Corporation, Microsoft Corporation. Advanced Power Management
198 * (APM) BIOS Interface Specification, Revision 1.2, February 1996.
200 * [This document is available from Microsoft at:
201 * http://www.microsoft.com/whdc/archive/amp_12.mspx]
204 #include <linux/module.h>
206 #include <linux/poll.h>
207 #include <linux/types.h>
208 #include <linux/stddef.h>
209 #include <linux/timer.h>
210 #include <linux/fcntl.h>
211 #include <linux/slab.h>
212 #include <linux/stat.h>
213 #include <linux/proc_fs.h>
214 #include <linux/seq_file.h>
215 #include <linux/miscdevice.h>
216 #include <linux/apm_bios.h>
217 #include <linux/init.h>
218 #include <linux/time.h>
219 #include <linux/sched.h>
220 #include <linux/pm.h>
221 #include <linux/capability.h>
222 #include <linux/device.h>
223 #include <linux/kernel.h>
224 #include <linux/freezer.h>
225 #include <linux/smp.h>
226 #include <linux/dmi.h>
227 #include <linux/suspend.h>
228 #include <linux/kthread.h>
229 #include <linux/jiffies.h>
230 #include <linux/acpi.h>
231 #include <linux/syscore_ops.h>
232 #include <linux/i8253.h>
234 #include <asm/uaccess.h>
235 #include <asm/desc.h>
236 #include <asm/olpc.h>
237 #include <asm/paravirt.h>
238 #include <asm/reboot.h>
240 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
241 extern int (*console_blank_hook)(int);
245 * The apm_bios device is one of the misc char devices.
246 * This is its minor number.
248 #define APM_MINOR_DEV 134
251 * Various options can be changed at boot time as follows:
252 * (We allow underscores for compatibility with the modules code)
253 * apm=on/off enable/disable APM
254 * [no-]allow[-_]ints allow interrupts during BIOS calls
255 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
256 * [no-]realmode[-_]power[-_]off switch to real mode before
258 * [no-]debug log some debugging messages
259 * [no-]power[-_]off power off on shutdown
260 * [no-]smp Use apm even on an SMP box
261 * bounce[-_]interval=<n> number of ticks to ignore suspend
263 * idle[-_]threshold=<n> System idle percentage above which to
264 * make APM BIOS idle calls. Set it to
266 * idle[-_]period=<n> Period (in 1/100s of a second) over
267 * which the idle percentage is
271 /* KNOWN PROBLEM MACHINES:
273 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
274 * [Confirmed by TI representative]
275 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
276 * [Confirmed by BIOS disassembly]
277 * [This may work now ...]
278 * P: Toshiba 1950S: battery life information only gets updated after resume
279 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
280 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
281 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
282 * Neale Banks <neale@lowendale.com.au> December 2000
284 * Legend: U = unusable with APM patches
285 * P = partially usable with APM patches
289 * Define as 1 to make the driver always call the APM BIOS busy
290 * routine even if the clock was not reported as slowed by the
291 * idle routine. Otherwise, define as 0.
293 #define ALWAYS_CALL_BUSY 1
296 * Define to make the APM BIOS calls zero all data segment registers (so
297 * that an incorrect BIOS implementation will cause a kernel panic if it
298 * tries to write to arbitrary memory).
300 #define APM_ZERO_SEGS
305 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
306 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
307 * David Chen <chen@ctpa04.mit.edu>
309 #undef INIT_TIMER_AFTER_SUSPEND
311 #ifdef INIT_TIMER_AFTER_SUSPEND
312 #include <linux/timex.h>
314 #include <linux/delay.h>
318 * Need to poll the APM BIOS every second
320 #define APM_CHECK_TIMEOUT (HZ)
323 * Ignore suspend events for this amount of time after a resume
325 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
328 * Maximum number of events stored
330 #define APM_MAX_EVENTS 20
333 * The per-file APM data
337 struct apm_user *next;
338 unsigned int suser: 1;
339 unsigned int writer: 1;
340 unsigned int reader: 1;
341 unsigned int suspend_wait: 1;
343 int suspends_pending;
344 int standbys_pending;
349 apm_event_t events[APM_MAX_EVENTS];
353 * The magic number in apm_user
355 #define APM_BIOS_MAGIC 0x4101
358 * idle percentage above which bios idle calls are done
360 #ifdef CONFIG_APM_CPU_IDLE
361 #warning deprecated CONFIG_APM_CPU_IDLE will be deleted in 2012
362 #define DEFAULT_IDLE_THRESHOLD 95
364 #define DEFAULT_IDLE_THRESHOLD 100
366 #define DEFAULT_IDLE_PERIOD (100 / 3)
372 unsigned long offset;
373 unsigned short segment;
375 #ifdef CONFIG_APM_CPU_IDLE
376 static int clock_slowed;
377 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
378 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
379 static int set_pm_idle;
381 static int suspends_pending;
382 static int standbys_pending;
383 static int ignore_sys_suspend;
384 static int ignore_normal_resume;
385 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
387 static bool debug __read_mostly;
388 static bool smp __read_mostly;
389 static int apm_disabled = -1;
391 static bool power_off;
393 static bool power_off = 1;
395 static bool realmode_power_off;
396 #ifdef CONFIG_APM_ALLOW_INTS
397 static bool allow_ints = 1;
399 static bool allow_ints;
401 static bool broken_psr;
403 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
404 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
405 static struct apm_user *user_list;
406 static DEFINE_SPINLOCK(user_list_lock);
407 static DEFINE_MUTEX(apm_mutex);
410 * Set up a segment that references the real mode segment 0x40
411 * that extends up to the end of page zero (that we have reserved).
412 * This is for buggy BIOS's that refer to (real mode) segment 0x40
413 * even though they are called in protected mode.
415 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
416 (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
418 static const char driver_version[] = "1.16ac"; /* no spaces */
420 static struct task_struct *kapmd_task;
423 * APM event names taken from the APM 1.2 specification. These are
424 * the message codes that the BIOS uses to tell us about events
426 static const char * const apm_event_name[] = {
432 "power status change",
437 "system standby resume",
438 "capabilities change"
440 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
442 typedef struct lookup_t {
448 * The BIOS returns a set of standard error codes in AX when the
452 static const lookup_t error_table[] = {
453 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
454 { APM_DISABLED, "Power management disabled" },
455 { APM_CONNECTED, "Real mode interface already connected" },
456 { APM_NOT_CONNECTED, "Interface not connected" },
457 { APM_16_CONNECTED, "16 bit interface already connected" },
458 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
459 { APM_32_CONNECTED, "32 bit interface already connected" },
460 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
461 { APM_BAD_DEVICE, "Unrecognized device ID" },
462 { APM_BAD_PARAM, "Parameter out of range" },
463 { APM_NOT_ENGAGED, "Interface not engaged" },
464 { APM_BAD_FUNCTION, "Function not supported" },
465 { APM_RESUME_DISABLED, "Resume timer disabled" },
466 { APM_BAD_STATE, "Unable to enter requested state" },
467 /* N/A { APM_NO_EVENTS, "No events pending" }, */
468 { APM_NO_ERROR, "BIOS did not set a return code" },
469 { APM_NOT_PRESENT, "No APM present" }
471 #define ERROR_COUNT ARRAY_SIZE(error_table)
474 * apm_error - display an APM error
475 * @str: information string
476 * @err: APM BIOS return code
478 * Write a meaningful log entry to the kernel log in the event of
479 * an APM error. Note that this also handles (negative) kernel errors.
482 static void apm_error(char *str, int err)
486 for (i = 0; i < ERROR_COUNT; i++)
487 if (error_table[i].key == err)
490 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
492 printk(KERN_NOTICE "apm: %s: linux error code %i\n", str, err);
494 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
499 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
500 * apm_info.allow_ints, we are being really paranoid here! Not only
501 * are interrupts disabled, but all the segment registers (except SS)
502 * are saved and zeroed this means that if the BIOS tries to reference
503 * any data without explicitly loading the segment registers, the kernel
504 * will fault immediately rather than have some unforeseen circumstances
505 * for the rest of the kernel. And it will be very obvious! :-) Doing
506 * this depends on CS referring to the same physical memory as DS so that
507 * DS can be zeroed before the call. Unfortunately, we can't do anything
508 * about the stack segment/pointer. Also, we tell the compiler that
509 * everything could change.
511 * Also, we KNOW that for the non error case of apm_bios_call, there
512 * is no useful data returned in the low order 8 bits of eax.
515 static inline unsigned long __apm_irq_save(void)
518 local_save_flags(flags);
519 if (apm_info.allow_ints) {
520 if (irqs_disabled_flags(flags))
528 #define apm_irq_save(flags) \
529 do { flags = __apm_irq_save(); } while (0)
531 static inline void apm_irq_restore(unsigned long flags)
533 if (irqs_disabled_flags(flags))
535 else if (irqs_disabled())
540 # define APM_DECL_SEGS \
541 unsigned int saved_fs; unsigned int saved_gs;
542 # define APM_DO_SAVE_SEGS \
543 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
544 # define APM_DO_RESTORE_SEGS \
545 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
547 # define APM_DECL_SEGS
548 # define APM_DO_SAVE_SEGS
549 # define APM_DO_RESTORE_SEGS
552 struct apm_bios_call {
562 /* Error: -ENOMEM, or bits 8-15 of eax */
567 * __apm_bios_call - Make an APM BIOS 32bit call
568 * @_call: pointer to struct apm_bios_call.
570 * Make an APM call using the 32bit protected mode interface. The
571 * caller is responsible for knowing if APM BIOS is configured and
572 * enabled. This call can disable interrupts for a long period of
573 * time on some laptops. The return value is in AH and the carry
574 * flag is loaded into AL. If there is an error, then the error
575 * code is returned in AH (bits 8-15 of eax) and this function
578 * Note: this makes the call on the current CPU.
580 static long __apm_bios_call(void *_call)
585 struct desc_struct save_desc_40;
586 struct desc_struct *gdt;
587 struct apm_bios_call *call = _call;
591 gdt = get_cpu_gdt_table(cpu);
592 save_desc_40 = gdt[0x40 / 8];
593 gdt[0x40 / 8] = bad_bios_desc;
597 apm_bios_call_asm(call->func, call->ebx, call->ecx,
598 &call->eax, &call->ebx, &call->ecx, &call->edx,
601 apm_irq_restore(flags);
602 gdt[0x40 / 8] = save_desc_40;
605 return call->eax & 0xff;
608 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
609 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
613 /* Don't bother with work_on_cpu in the common case, so we don't
614 * have to worry about OOM or overhead. */
615 if (get_cpu() == 0) {
620 ret = work_on_cpu(0, fn, call);
623 /* work_on_cpu can fail with -ENOMEM */
627 call->err = (call->eax >> 8) & 0xff;
633 * apm_bios_call - Make an APM BIOS 32bit call (on CPU 0)
634 * @call: the apm_bios_call registers.
636 * If there is an error, it is returned in @call.err.
638 static int apm_bios_call(struct apm_bios_call *call)
640 return on_cpu0(__apm_bios_call, call);
644 * __apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
645 * @_call: pointer to struct apm_bios_call.
647 * Make a BIOS call that returns one value only, or just status.
648 * If there is an error, then the error code is returned in AH
649 * (bits 8-15 of eax) and this function returns non-zero (it can
650 * also return -ENOMEM). This is used for simpler BIOS operations.
651 * This call may hold interrupts off for a long time on some laptops.
653 * Note: this makes the call on the current CPU.
655 static long __apm_bios_call_simple(void *_call)
661 struct desc_struct save_desc_40;
662 struct desc_struct *gdt;
663 struct apm_bios_call *call = _call;
667 gdt = get_cpu_gdt_table(cpu);
668 save_desc_40 = gdt[0x40 / 8];
669 gdt[0x40 / 8] = bad_bios_desc;
673 error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
676 apm_irq_restore(flags);
677 gdt[0x40 / 8] = save_desc_40;
683 * apm_bios_call_simple - make a simple APM BIOS 32bit call
684 * @func: APM function to invoke
685 * @ebx_in: EBX register value for BIOS call
686 * @ecx_in: ECX register value for BIOS call
687 * @eax: EAX register on return from the BIOS call
690 * Make a BIOS call that returns one value only, or just status.
691 * If there is an error, then the error code is returned in @err
692 * and this function returns non-zero. This is used for simpler
693 * BIOS operations. This call may hold interrupts off for a long
694 * time on some laptops.
696 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
699 struct apm_bios_call call;
706 ret = on_cpu0(__apm_bios_call_simple, &call);
713 * apm_driver_version - APM driver version
714 * @val: loaded with the APM version on return
716 * Retrieve the APM version supported by the BIOS. This is only
717 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
720 * On entry val should point to a value indicating the APM driver
721 * version with the high byte being the major and the low byte the
722 * minor number both in BCD
724 * On return it will hold the BIOS revision supported in the
728 static int apm_driver_version(u_short *val)
733 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
740 * apm_get_event - get an APM event from the BIOS
741 * @event: pointer to the event
742 * @info: point to the event information
744 * The APM BIOS provides a polled information for event
745 * reporting. The BIOS expects to be polled at least every second
746 * when events are pending. When a message is found the caller should
747 * poll until no more messages are present. However, this causes
748 * problems on some laptops where a suspend event notification is
749 * not cleared until it is acknowledged.
751 * Additional information is returned in the info pointer, providing
752 * that APM 1.2 is in use. If no messges are pending the value 0x80
753 * is returned (No power management events pending).
755 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
757 struct apm_bios_call call;
759 call.func = APM_FUNC_GET_EVENT;
760 call.ebx = call.ecx = 0;
762 if (apm_bios_call(&call))
766 if (apm_info.connection_version < 0x0102)
767 *info = ~0; /* indicate info not valid */
774 * set_power_state - set the power management state
775 * @what: which items to transition
776 * @state: state to transition to
778 * Request an APM change of state for one or more system devices. The
779 * processor state must be transitioned last of all. what holds the
780 * class of device in the upper byte and the device number (0xFF for
781 * all) for the object to be transitioned.
783 * The state holds the state to transition to, which may in fact
784 * be an acceptance of a BIOS requested state change.
787 static int set_power_state(u_short what, u_short state)
792 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
798 * set_system_power_state - set system wide power state
799 * @state: which state to enter
801 * Transition the entire system into a new APM power state.
804 static int set_system_power_state(u_short state)
806 return set_power_state(APM_DEVICE_ALL, state);
809 #ifdef CONFIG_APM_CPU_IDLE
811 * apm_do_idle - perform power saving
813 * This function notifies the BIOS that the processor is (in the view
814 * of the OS) idle. It returns -1 in the event that the BIOS refuses
815 * to handle the idle request. On a success the function returns 1
816 * if the BIOS did clock slowing or 0 otherwise.
819 static int apm_do_idle(void)
827 polling = !!(current_thread_info()->status & TS_POLLING);
829 current_thread_info()->status &= ~TS_POLLING;
831 * TS_POLLING-cleared state must be visible before we
836 if (!need_resched()) {
838 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
841 current_thread_info()->status |= TS_POLLING;
847 static unsigned long t;
849 /* This always fails on some SMP boards running UP kernels.
850 * Only report the failure the first 5 times.
853 printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
858 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
863 * apm_do_busy - inform the BIOS the CPU is busy
865 * Request that the BIOS brings the CPU back to full performance.
868 static void apm_do_busy(void)
873 if (clock_slowed || ALWAYS_CALL_BUSY) {
874 (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
880 * If no process has really been interested in
881 * the CPU for some time, we want to call BIOS
882 * power management - we probably want
885 #define IDLE_CALC_LIMIT (HZ * 100)
886 #define IDLE_LEAKY_MAX 16
888 static void (*original_pm_idle)(void) __read_mostly;
891 * apm_cpu_idle - cpu idling for APM capable Linux
893 * This is the idling function the kernel executes when APM is available. It
894 * tries to do BIOS powermanagement based on the average system idle time.
895 * Furthermore it calls the system default idle routine.
898 static void apm_cpu_idle(void)
900 static int use_apm_idle; /* = 0 */
901 static unsigned int last_jiffies; /* = 0 */
902 static unsigned int last_stime; /* = 0 */
904 int apm_idle_done = 0;
905 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
908 WARN_ONCE(1, "deprecated apm_cpu_idle will be deleted in 2012");
910 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
912 last_jiffies = jiffies;
913 last_stime = current->stime;
914 } else if (jiffies_since_last_check > idle_period) {
915 unsigned int idle_percentage;
917 idle_percentage = current->stime - last_stime;
918 idle_percentage *= 100;
919 idle_percentage /= jiffies_since_last_check;
920 use_apm_idle = (idle_percentage > idle_threshold);
921 if (apm_info.forbid_idle)
923 last_jiffies = jiffies;
924 last_stime = current->stime;
927 bucket = IDLE_LEAKY_MAX;
929 while (!need_resched()) {
934 switch (apm_do_idle()) {
939 bucket = IDLE_LEAKY_MAX;
950 default: /* BIOS refused */
954 if (original_pm_idle)
959 jiffies_since_last_check = jiffies - last_jiffies;
960 if (jiffies_since_last_check > idle_period)
972 * apm_power_off - ask the BIOS to power off
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.
981 static void apm_power_off(void)
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);
988 (void)set_system_power_state(APM_STATE_OFF);
992 #ifdef CONFIG_APM_DO_ENABLE
995 * apm_enable_power_management - enable BIOS APM power management
996 * @enable: enable yes/no
998 * Enable or disable the APM BIOS power services.
1001 static int apm_enable_power_management(int enable)
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))
1012 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1014 apm_info.bios.flags |= APM_BIOS_DISABLED;
1020 * apm_get_power_status - get current power state
1021 * @status: returned status
1022 * @bat: battery info
1023 * @life: estimated life
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 secodnds/minutes at current powwer
1033 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1035 struct apm_bios_call call;
1037 call.func = APM_FUNC_GET_STATUS;
1038 call.ebx = APM_DEVICE_ALL;
1041 if (apm_info.get_power_status_broken)
1042 return APM_32_UNSUPPORTED;
1043 if (apm_bios_call(&call))
1047 if (apm_info.get_power_status_swabinminutes) {
1048 *life = swab16((u16)call.edx);
1056 static int apm_get_battery_status(u_short which, u_short *status,
1057 u_short *bat, u_short *life, u_short *nbat)
1065 if (apm_info.connection_version < 0x0102) {
1066 /* pretend we only have one battery. */
1068 return APM_BAD_DEVICE;
1070 return apm_get_power_status(status, bat, life);
1073 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1074 &ebx, &ecx, &edx, &esi))
1075 return (eax >> 8) & 0xff;
1085 * apm_engage_power_management - enable PM on a device
1086 * @device: identity of device
1089 * Activate or deactive power management on either a specific device
1090 * or the entire system (%APM_DEVICE_ALL).
1093 static int apm_engage_power_management(u_short device, int enable)
1098 if ((enable == 0) && (device == APM_DEVICE_ALL)
1099 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1100 return APM_DISABLED;
1101 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1104 if (device == APM_DEVICE_ALL) {
1106 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1108 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1113 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1116 * apm_console_blank - blank the display
1119 * Attempt to blank the console, firstly by blanking just video device
1120 * zero, and if that fails (some BIOSes don't support it) then it blanks
1121 * all video devices. Typically the BIOS will do laptop backlight and
1122 * monitor powerdown for us.
1125 static int apm_console_blank(int blank)
1127 int error = APM_NOT_ENGAGED; /* silence gcc */
1130 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1132 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1134 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1135 error = set_power_state(dev[i], state);
1137 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1140 if (error == APM_NOT_ENGAGED)
1144 if (error == APM_NOT_ENGAGED) {
1148 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1150 apm_error("set display", error);
1151 apm_error("engage interface", eng_error);
1154 return apm_console_blank(blank);
1157 apm_error("set display", error);
1162 static int queue_empty(struct apm_user *as)
1164 return as->event_head == as->event_tail;
1167 static apm_event_t get_queued_event(struct apm_user *as)
1169 if (++as->event_tail >= APM_MAX_EVENTS)
1171 return as->events[as->event_tail];
1174 static void queue_event(apm_event_t event, struct apm_user *sender)
1176 struct apm_user *as;
1178 spin_lock(&user_list_lock);
1179 if (user_list == NULL)
1181 for (as = user_list; as != NULL; as = as->next) {
1182 if ((as == sender) || (!as->reader))
1184 if (++as->event_head >= APM_MAX_EVENTS)
1187 if (as->event_head == as->event_tail) {
1188 static int notified;
1190 if (notified++ == 0)
1191 printk(KERN_ERR "apm: an event queue overflowed\n");
1192 if (++as->event_tail >= APM_MAX_EVENTS)
1195 as->events[as->event_head] = event;
1196 if (!as->suser || !as->writer)
1199 case APM_SYS_SUSPEND:
1200 case APM_USER_SUSPEND:
1201 as->suspends_pending++;
1205 case APM_SYS_STANDBY:
1206 case APM_USER_STANDBY:
1207 as->standbys_pending++;
1212 wake_up_interruptible(&apm_waitqueue);
1214 spin_unlock(&user_list_lock);
1217 static void reinit_timer(void)
1219 #ifdef INIT_TIMER_AFTER_SUSPEND
1220 unsigned long flags;
1222 raw_spin_lock_irqsave(&i8253_lock, flags);
1223 /* set the clock to HZ */
1224 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1226 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1228 outb_p(LATCH >> 8, PIT_CH0); /* MSB */
1230 raw_spin_unlock_irqrestore(&i8253_lock, flags);
1234 static int suspend(int vetoable)
1237 struct apm_user *as;
1239 dpm_suspend_start(PMSG_SUSPEND);
1240 dpm_suspend_end(PMSG_SUSPEND);
1242 local_irq_disable();
1247 save_processor_state();
1248 err = set_system_power_state(APM_STATE_SUSPEND);
1249 ignore_normal_resume = 1;
1250 restore_processor_state();
1252 local_irq_disable();
1255 if (err == APM_NO_ERROR)
1257 if (err != APM_SUCCESS)
1258 apm_error("suspend", err);
1259 err = (err == APM_SUCCESS) ? 0 : -EIO;
1264 dpm_resume_start(PMSG_RESUME);
1265 dpm_resume_end(PMSG_RESUME);
1267 queue_event(APM_NORMAL_RESUME, NULL);
1268 spin_lock(&user_list_lock);
1269 for (as = user_list; as != NULL; as = as->next) {
1270 as->suspend_wait = 0;
1271 as->suspend_result = err;
1273 spin_unlock(&user_list_lock);
1274 wake_up_interruptible(&apm_suspend_waitqueue);
1278 static void standby(void)
1282 dpm_suspend_end(PMSG_SUSPEND);
1284 local_irq_disable();
1288 err = set_system_power_state(APM_STATE_STANDBY);
1289 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1290 apm_error("standby", err);
1292 local_irq_disable();
1296 dpm_resume_start(PMSG_RESUME);
1299 static apm_event_t get_event(void)
1302 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1303 apm_eventinfo_t info;
1305 static int notified;
1307 /* we don't use the eventinfo */
1308 error = apm_get_event(&event, &info);
1309 if (error == APM_SUCCESS)
1312 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1313 apm_error("get_event", error);
1318 static void check_events(void)
1321 static unsigned long last_resume;
1322 static int ignore_bounce;
1324 while ((event = get_event()) != 0) {
1326 if (event <= NR_APM_EVENT_NAME)
1327 printk(KERN_DEBUG "apm: received %s notify\n",
1328 apm_event_name[event - 1]);
1330 printk(KERN_DEBUG "apm: received unknown "
1331 "event 0x%02x\n", event);
1334 && (time_after(jiffies, last_resume + bounce_interval)))
1338 case APM_SYS_STANDBY:
1339 case APM_USER_STANDBY:
1340 queue_event(event, NULL);
1341 if (standbys_pending <= 0)
1345 case APM_USER_SUSPEND:
1346 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1347 if (apm_info.connection_version > 0x100)
1348 set_system_power_state(APM_STATE_REJECT);
1351 case APM_SYS_SUSPEND:
1352 if (ignore_bounce) {
1353 if (apm_info.connection_version > 0x100)
1354 set_system_power_state(APM_STATE_REJECT);
1358 * If we are already processing a SUSPEND,
1359 * then further SUSPEND events from the BIOS
1360 * will be ignored. We also return here to
1361 * cope with the fact that the Thinkpads keep
1362 * sending a SUSPEND event until something else
1365 if (ignore_sys_suspend)
1367 ignore_sys_suspend = 1;
1368 queue_event(event, NULL);
1369 if (suspends_pending <= 0)
1373 case APM_NORMAL_RESUME:
1374 case APM_CRITICAL_RESUME:
1375 case APM_STANDBY_RESUME:
1376 ignore_sys_suspend = 0;
1377 last_resume = jiffies;
1379 if ((event != APM_NORMAL_RESUME)
1380 || (ignore_normal_resume == 0)) {
1381 dpm_resume_end(PMSG_RESUME);
1382 queue_event(event, NULL);
1384 ignore_normal_resume = 0;
1387 case APM_CAPABILITY_CHANGE:
1388 case APM_LOW_BATTERY:
1389 case APM_POWER_STATUS_CHANGE:
1390 queue_event(event, NULL);
1391 /* If needed, notify drivers here */
1394 case APM_UPDATE_TIME:
1397 case APM_CRITICAL_SUSPEND:
1399 * We are not allowed to reject a critical suspend.
1407 static void apm_event_handler(void)
1409 static int pending_count = 4;
1412 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1413 if ((apm_info.connection_version > 0x100) &&
1414 (pending_count-- <= 0)) {
1417 printk(KERN_DEBUG "apm: setting state busy\n");
1418 err = set_system_power_state(APM_STATE_BUSY);
1420 apm_error("busy", err);
1428 * This is the APM thread main loop.
1431 static void apm_mainloop(void)
1433 DECLARE_WAITQUEUE(wait, current);
1435 add_wait_queue(&apm_waitqueue, &wait);
1436 set_current_state(TASK_INTERRUPTIBLE);
1438 schedule_timeout(APM_CHECK_TIMEOUT);
1439 if (kthread_should_stop())
1442 * Ok, check all events, check for idle (and mark us sleeping
1443 * so as not to count towards the load average)..
1445 set_current_state(TASK_INTERRUPTIBLE);
1446 apm_event_handler();
1448 remove_wait_queue(&apm_waitqueue, &wait);
1451 static int check_apm_user(struct apm_user *as, const char *func)
1453 if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1454 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1460 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1462 struct apm_user *as;
1466 as = fp->private_data;
1467 if (check_apm_user(as, "read"))
1469 if ((int)count < sizeof(apm_event_t))
1471 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1473 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1475 while ((i >= sizeof(event)) && !queue_empty(as)) {
1476 event = get_queued_event(as);
1477 if (copy_to_user(buf, &event, sizeof(event))) {
1483 case APM_SYS_SUSPEND:
1484 case APM_USER_SUSPEND:
1485 as->suspends_read++;
1488 case APM_SYS_STANDBY:
1489 case APM_USER_STANDBY:
1490 as->standbys_read++;
1493 buf += sizeof(event);
1498 if (signal_pending(current))
1499 return -ERESTARTSYS;
1503 static unsigned int do_poll(struct file *fp, poll_table *wait)
1505 struct apm_user *as;
1507 as = fp->private_data;
1508 if (check_apm_user(as, "poll"))
1510 poll_wait(fp, &apm_waitqueue, wait);
1511 if (!queue_empty(as))
1512 return POLLIN | POLLRDNORM;
1516 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1518 struct apm_user *as;
1521 as = filp->private_data;
1522 if (check_apm_user(as, "ioctl"))
1524 if (!as->suser || !as->writer)
1527 case APM_IOC_STANDBY:
1528 mutex_lock(&apm_mutex);
1529 if (as->standbys_read > 0) {
1530 as->standbys_read--;
1531 as->standbys_pending--;
1534 queue_event(APM_USER_STANDBY, as);
1535 if (standbys_pending <= 0)
1537 mutex_unlock(&apm_mutex);
1539 case APM_IOC_SUSPEND:
1540 mutex_lock(&apm_mutex);
1541 if (as->suspends_read > 0) {
1542 as->suspends_read--;
1543 as->suspends_pending--;
1546 queue_event(APM_USER_SUSPEND, as);
1547 if (suspends_pending <= 0) {
1549 mutex_unlock(&apm_mutex);
1551 as->suspend_wait = 1;
1552 mutex_unlock(&apm_mutex);
1553 wait_event_interruptible(apm_suspend_waitqueue,
1554 as->suspend_wait == 0);
1555 ret = as->suspend_result;
1564 static int do_release(struct inode *inode, struct file *filp)
1566 struct apm_user *as;
1568 as = filp->private_data;
1569 if (check_apm_user(as, "release"))
1571 filp->private_data = NULL;
1572 if (as->standbys_pending > 0) {
1573 standbys_pending -= as->standbys_pending;
1574 if (standbys_pending <= 0)
1577 if (as->suspends_pending > 0) {
1578 suspends_pending -= as->suspends_pending;
1579 if (suspends_pending <= 0)
1582 spin_lock(&user_list_lock);
1583 if (user_list == as)
1584 user_list = as->next;
1586 struct apm_user *as1;
1588 for (as1 = user_list;
1589 (as1 != NULL) && (as1->next != as);
1593 printk(KERN_ERR "apm: filp not in user list\n");
1595 as1->next = as->next;
1597 spin_unlock(&user_list_lock);
1602 static int do_open(struct inode *inode, struct file *filp)
1604 struct apm_user *as;
1606 as = kmalloc(sizeof(*as), GFP_KERNEL);
1608 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1612 as->magic = APM_BIOS_MAGIC;
1613 as->event_tail = as->event_head = 0;
1614 as->suspends_pending = as->standbys_pending = 0;
1615 as->suspends_read = as->standbys_read = 0;
1617 * XXX - this is a tiny bit broken, when we consider BSD
1618 * process accounting. If the device is opened by root, we
1619 * instantly flag that we used superuser privs. Who knows,
1620 * we might close the device immediately without doing a
1621 * privileged operation -- cevans
1623 as->suser = capable(CAP_SYS_ADMIN);
1624 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1625 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1626 spin_lock(&user_list_lock);
1627 as->next = user_list;
1629 spin_unlock(&user_list_lock);
1630 filp->private_data = as;
1634 static int proc_apm_show(struct seq_file *m, void *v)
1640 unsigned short ac_line_status = 0xff;
1641 unsigned short battery_status = 0xff;
1642 unsigned short battery_flag = 0xff;
1643 int percentage = -1;
1644 int time_units = -1;
1647 if ((num_online_cpus() == 1) &&
1648 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1649 ac_line_status = (bx >> 8) & 0xff;
1650 battery_status = bx & 0xff;
1651 if ((cx & 0xff) != 0xff)
1652 percentage = cx & 0xff;
1654 if (apm_info.connection_version > 0x100) {
1655 battery_flag = (cx >> 8) & 0xff;
1657 units = (dx & 0x8000) ? "min" : "sec";
1658 time_units = dx & 0x7fff;
1662 /* Arguments, with symbols from linux/apm_bios.h. Information is
1663 from the Get Power Status (0x0a) call unless otherwise noted.
1665 0) Linux driver version (this will change if format changes)
1666 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1667 2) APM flags from APM Installation Check (0x00):
1668 bit 0: APM_16_BIT_SUPPORT
1669 bit 1: APM_32_BIT_SUPPORT
1670 bit 2: APM_IDLE_SLOWS_CLOCK
1671 bit 3: APM_BIOS_DISABLED
1672 bit 4: APM_BIOS_DISENGAGED
1676 0x02: On backup power (BIOS >= 1.1 only)
1683 0x04: Selected battery not present (BIOS >= 1.2 only)
1690 bit 7: No system battery
1692 6) Remaining battery life (percentage of charge):
1695 7) Remaining battery life (time units):
1696 Number of remaining minutes or seconds
1698 8) min = minutes; sec = seconds */
1700 seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1702 (apm_info.bios.version >> 8) & 0xff,
1703 apm_info.bios.version & 0xff,
1704 apm_info.bios.flags,
1714 static int proc_apm_open(struct inode *inode, struct file *file)
1716 return single_open(file, proc_apm_show, NULL);
1719 static const struct file_operations apm_file_ops = {
1720 .owner = THIS_MODULE,
1721 .open = proc_apm_open,
1723 .llseek = seq_lseek,
1724 .release = single_release,
1727 static int apm(void *unused)
1737 * This is to avoid random crashes at boot time during initialization
1738 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1739 * Some bioses don't like being called from CPU != 0.
1740 * Method suggested by Ingo Molnar.
1742 set_cpus_allowed_ptr(current, cpumask_of(0));
1743 BUG_ON(smp_processor_id() != 0);
1745 if (apm_info.connection_version == 0) {
1746 apm_info.connection_version = apm_info.bios.version;
1747 if (apm_info.connection_version > 0x100) {
1749 * We only support BIOSs up to version 1.2
1751 if (apm_info.connection_version > 0x0102)
1752 apm_info.connection_version = 0x0102;
1753 error = apm_driver_version(&apm_info.connection_version);
1754 if (error != APM_SUCCESS) {
1755 apm_error("driver version", error);
1756 /* Fall back to an APM 1.0 connection. */
1757 apm_info.connection_version = 0x100;
1763 printk(KERN_INFO "apm: Connection version %d.%d\n",
1764 (apm_info.connection_version >> 8) & 0xff,
1765 apm_info.connection_version & 0xff);
1767 #ifdef CONFIG_APM_DO_ENABLE
1768 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1770 * This call causes my NEC UltraLite Versa 33/C to hang if it
1771 * is booted with PM disabled but not in the docking station.
1774 error = apm_enable_power_management(1);
1776 apm_error("enable power management", error);
1782 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1783 && (apm_info.connection_version > 0x0100)) {
1784 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1786 apm_error("engage power management", error);
1791 if (debug && (num_online_cpus() == 1 || smp)) {
1792 error = apm_get_power_status(&bx, &cx, &dx);
1794 printk(KERN_INFO "apm: power status not available\n");
1796 switch ((bx >> 8) & 0xff) {
1798 power_stat = "off line";
1801 power_stat = "on line";
1804 power_stat = "on backup power";
1807 power_stat = "unknown";
1810 switch (bx & 0xff) {
1818 bat_stat = "critical";
1821 bat_stat = "charging";
1824 bat_stat = "unknown";
1828 "apm: AC %s, battery status %s, battery life ",
1829 power_stat, bat_stat);
1830 if ((cx & 0xff) == 0xff)
1831 printk("unknown\n");
1833 printk("%d%%\n", cx & 0xff);
1834 if (apm_info.connection_version > 0x100) {
1836 "apm: battery flag 0x%02x, battery life ",
1839 printk("unknown\n");
1841 printk("%d %s\n", dx & 0x7fff,
1843 "minutes" : "seconds");
1848 /* Install our power off handler.. */
1850 pm_power_off = apm_power_off;
1852 if (num_online_cpus() == 1 || smp) {
1853 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1854 console_blank_hook = apm_console_blank;
1857 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1858 console_blank_hook = NULL;
1866 static int __init apm_setup(char *str)
1870 while ((str != NULL) && (*str != '\0')) {
1871 if (strncmp(str, "off", 3) == 0)
1873 if (strncmp(str, "on", 2) == 0)
1875 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1876 (strncmp(str, "bounce_interval=", 16) == 0))
1877 bounce_interval = simple_strtol(str + 16, NULL, 0);
1878 #ifdef CONFIG_APM_CPU_IDLE
1879 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1880 (strncmp(str, "idle_threshold=", 15) == 0))
1881 idle_threshold = simple_strtol(str + 15, NULL, 0);
1882 if ((strncmp(str, "idle-period=", 12) == 0) ||
1883 (strncmp(str, "idle_period=", 12) == 0))
1884 idle_period = simple_strtol(str + 12, NULL, 0);
1886 invert = (strncmp(str, "no-", 3) == 0) ||
1887 (strncmp(str, "no_", 3) == 0);
1890 if (strncmp(str, "debug", 5) == 0)
1892 if ((strncmp(str, "power-off", 9) == 0) ||
1893 (strncmp(str, "power_off", 9) == 0))
1894 power_off = !invert;
1895 if (strncmp(str, "smp", 3) == 0) {
1897 idle_threshold = 100;
1899 if ((strncmp(str, "allow-ints", 10) == 0) ||
1900 (strncmp(str, "allow_ints", 10) == 0))
1901 apm_info.allow_ints = !invert;
1902 if ((strncmp(str, "broken-psr", 10) == 0) ||
1903 (strncmp(str, "broken_psr", 10) == 0))
1904 apm_info.get_power_status_broken = !invert;
1905 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1906 (strncmp(str, "realmode_power_off", 18) == 0))
1907 apm_info.realmode_power_off = !invert;
1908 str = strchr(str, ',');
1910 str += strspn(str, ", \t");
1915 __setup("apm=", apm_setup);
1918 static const struct file_operations apm_bios_fops = {
1919 .owner = THIS_MODULE,
1922 .unlocked_ioctl = do_ioctl,
1924 .release = do_release,
1925 .llseek = noop_llseek,
1928 static struct miscdevice apm_device = {
1935 /* Simple "print if true" callback */
1936 static int __init print_if_true(const struct dmi_system_id *d)
1938 printk("%s\n", d->ident);
1943 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1944 * disabled before the suspend. Linux used to get terribly confused by that.
1946 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1948 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1949 "workaround hopefully not needed.\n", d->ident);
1953 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1954 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1956 if (apm_info.realmode_power_off == 0) {
1957 apm_info.realmode_power_off = 1;
1958 printk(KERN_INFO "%s bios detected. "
1959 "Using realmode poweroff only.\n", d->ident);
1964 /* Some laptops require interrupts to be enabled during APM calls */
1965 static int __init set_apm_ints(const struct dmi_system_id *d)
1967 if (apm_info.allow_ints == 0) {
1968 apm_info.allow_ints = 1;
1969 printk(KERN_INFO "%s machine detected. "
1970 "Enabling interrupts during APM calls.\n", d->ident);
1975 /* Some APM bioses corrupt memory or just plain do not work */
1976 static int __init apm_is_horked(const struct dmi_system_id *d)
1978 if (apm_info.disabled == 0) {
1979 apm_info.disabled = 1;
1980 printk(KERN_INFO "%s machine detected. "
1981 "Disabling APM.\n", d->ident);
1986 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1988 if (apm_info.disabled == 0) {
1989 apm_info.disabled = 1;
1990 printk(KERN_INFO "%s machine detected. "
1991 "Disabling APM.\n", d->ident);
1992 printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1993 printk(KERN_INFO "download from support.intel.com\n");
1998 /* Some APM bioses hang on APM idle calls */
1999 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
2001 if (apm_info.forbid_idle == 0) {
2002 apm_info.forbid_idle = 1;
2003 printk(KERN_INFO "%s machine detected. "
2004 "Disabling APM idle calls.\n", d->ident);
2010 * Check for clue free BIOS implementations who use
2011 * the following QA technique
2013 * [ Write BIOS Code ]<------
2015 * < Does it Compile >----N--
2017 * < Does it Boot Win98 >-N--
2021 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
2022 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
2024 static int __init broken_apm_power(const struct dmi_system_id *d)
2026 apm_info.get_power_status_broken = 1;
2027 printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2028 "disabling power status reporting.\n");
2033 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2034 * have this problem).
2036 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2038 apm_info.get_power_status_swabinminutes = 1;
2039 printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2040 "in minutes and wrong byte order.\n");
2044 static struct dmi_system_id __initdata apm_dmi_table[] = {
2047 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2048 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2049 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2051 { /* Handle problems with APM on the C600 */
2052 broken_ps2_resume, "Dell Latitude C600",
2053 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2054 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2056 { /* Allow interrupts during suspend on Dell Latitude laptops*/
2057 set_apm_ints, "Dell Latitude",
2058 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2059 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2062 apm_is_horked, "Dell Inspiron 2500",
2063 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2064 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2065 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2066 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2068 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
2069 set_apm_ints, "Dell Inspiron", {
2070 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2071 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2073 { /* Handle problems with APM on Inspiron 5000e */
2074 broken_apm_power, "Dell Inspiron 5000e",
2075 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2076 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2077 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2079 { /* Handle problems with APM on Inspiron 2500 */
2080 broken_apm_power, "Dell Inspiron 2500",
2081 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2082 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2083 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2086 apm_is_horked, "Dell Dimension 4100",
2087 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2088 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2089 DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2090 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2092 { /* Allow interrupts during suspend on Compaq Laptops*/
2093 set_apm_ints, "Compaq 12XL125",
2094 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2095 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2096 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2097 DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2099 { /* Allow interrupts during APM or the clock goes slow */
2100 set_apm_ints, "ASUSTeK",
2101 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2102 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2104 { /* APM blows on shutdown */
2105 apm_is_horked, "ABIT KX7-333[R]",
2106 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2107 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2110 apm_is_horked, "Trigem Delhi3",
2111 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2112 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2115 apm_is_horked, "Fujitsu-Siemens",
2116 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2117 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2120 apm_is_horked_d850md, "Intel D850MD",
2121 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2122 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2125 apm_is_horked, "Intel D810EMO",
2126 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2127 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2130 apm_is_horked, "Dell XPS-Z",
2131 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2132 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2133 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2136 apm_is_horked, "Sharp PC-PJ/AX",
2137 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2138 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2139 DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2140 DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2143 apm_is_horked, "Dell Inspiron 2500",
2144 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2145 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2146 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2147 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2149 { /* APM idle hangs */
2150 apm_likes_to_melt, "Jabil AMD",
2151 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2152 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2154 { /* APM idle hangs */
2155 apm_likes_to_melt, "AMI Bios",
2156 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2157 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2159 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2160 swab_apm_power_in_minutes, "Sony VAIO",
2161 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2162 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2163 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2165 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2166 swab_apm_power_in_minutes, "Sony VAIO",
2167 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2168 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2169 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2171 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2172 swab_apm_power_in_minutes, "Sony VAIO",
2173 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2174 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2175 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
2177 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2178 swab_apm_power_in_minutes, "Sony VAIO",
2179 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2180 DMI_MATCH(DMI_BIOS_VERSION, "R0121Z1"),
2181 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2183 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2184 swab_apm_power_in_minutes, "Sony VAIO",
2185 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2186 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2187 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2189 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2190 swab_apm_power_in_minutes, "Sony VAIO",
2191 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2192 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2193 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
2195 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2196 swab_apm_power_in_minutes, "Sony VAIO",
2197 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2198 DMI_MATCH(DMI_BIOS_VERSION, "R0203D0"),
2199 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2201 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2202 swab_apm_power_in_minutes, "Sony VAIO",
2203 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2204 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2205 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2207 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2208 swab_apm_power_in_minutes, "Sony VAIO",
2209 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2211 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2213 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2214 swab_apm_power_in_minutes, "Sony VAIO",
2215 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2216 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2217 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2220 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2221 swab_apm_power_in_minutes, "Sony VAIO",
2222 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2223 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2224 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
2226 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2227 swab_apm_power_in_minutes, "Sony VAIO",
2228 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2229 DMI_MATCH(DMI_BIOS_VERSION, "R0204P1"),
2230 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2232 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2233 swab_apm_power_in_minutes, "Sony VAIO",
2234 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2235 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2236 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2238 { /* broken PM poweroff bios */
2239 set_realmode_power_off, "Award Software v4.60 PGMA",
2240 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2241 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2242 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2245 /* Generic per vendor APM settings */
2247 { /* Allow interrupts during suspend on IBM laptops */
2248 set_apm_ints, "IBM",
2249 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2256 * Just start the APM thread. We do NOT want to do APM BIOS
2257 * calls from anything but the APM thread, if for no other reason
2258 * than the fact that we don't trust the APM BIOS. This way,
2259 * most common APM BIOS problems that lead to protection errors
2260 * etc will have at least some level of being contained...
2262 * In short, if something bad happens, at least we have a choice
2263 * of just killing the apm thread..
2265 static int __init apm_init(void)
2267 struct desc_struct *gdt;
2270 dmi_check_system(apm_dmi_table);
2272 if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2273 printk(KERN_INFO "apm: BIOS not found.\n");
2277 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2278 ((apm_info.bios.version >> 8) & 0xff),
2279 (apm_info.bios.version & 0xff),
2280 apm_info.bios.flags,
2282 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2283 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2288 apm_info.allow_ints = 1;
2290 apm_info.get_power_status_broken = 1;
2291 if (realmode_power_off)
2292 apm_info.realmode_power_off = 1;
2293 /* User can override, but default is to trust DMI */
2294 if (apm_disabled != -1)
2295 apm_info.disabled = apm_disabled;
2298 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2299 * but is reportedly a 1.0 BIOS.
2301 if (apm_info.bios.version == 0x001)
2302 apm_info.bios.version = 0x100;
2304 /* BIOS < 1.2 doesn't set cseg_16_len */
2305 if (apm_info.bios.version < 0x102)
2306 apm_info.bios.cseg_16_len = 0; /* 64k */
2309 printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2310 apm_info.bios.cseg, apm_info.bios.offset,
2311 apm_info.bios.cseg_16, apm_info.bios.dseg);
2312 if (apm_info.bios.version > 0x100)
2313 printk(" cseg len %x, dseg len %x",
2314 apm_info.bios.cseg_len,
2315 apm_info.bios.dseg_len);
2316 if (apm_info.bios.version > 0x101)
2317 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2321 if (apm_info.disabled) {
2322 printk(KERN_NOTICE "apm: disabled on user request.\n");
2325 if ((num_online_cpus() > 1) && !power_off && !smp) {
2326 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2327 apm_info.disabled = 1;
2330 if (!acpi_disabled) {
2331 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2332 apm_info.disabled = 1;
2337 * Set up the long jump entry point to the APM BIOS, which is called
2338 * from inline assembly.
2340 apm_bios_entry.offset = apm_info.bios.offset;
2341 apm_bios_entry.segment = APM_CS;
2344 * The APM 1.1 BIOS is supposed to provide limit information that it
2345 * recognizes. Many machines do this correctly, but many others do
2346 * not restrict themselves to their claimed limit. When this happens,
2347 * they will cause a segmentation violation in the kernel at boot time.
2348 * Most BIOS's, however, will respect a 64k limit, so we use that.
2350 * Note we only set APM segments on CPU zero, since we pin the APM
2353 gdt = get_cpu_gdt_table(0);
2354 set_desc_base(&gdt[APM_CS >> 3],
2355 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2356 set_desc_base(&gdt[APM_CS_16 >> 3],
2357 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2358 set_desc_base(&gdt[APM_DS >> 3],
2359 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2361 proc_create("apm", 0, NULL, &apm_file_ops);
2363 kapmd_task = kthread_create(apm, NULL, "kapmd");
2364 if (IS_ERR(kapmd_task)) {
2365 printk(KERN_ERR "apm: disabled - Unable to start kernel "
2367 err = PTR_ERR(kapmd_task);
2369 remove_proc_entry("apm", NULL);
2372 wake_up_process(kapmd_task);
2374 if (num_online_cpus() > 1 && !smp) {
2376 "apm: disabled - APM is not SMP safe (power off active).\n");
2381 * Note we don't actually care if the misc_device cannot be registered.
2382 * this driver can do its job without it, even if userspace can't
2383 * control it. just log the error
2385 if (misc_register(&apm_device))
2386 printk(KERN_WARNING "apm: Could not register misc device.\n");
2388 #ifdef CONFIG_APM_CPU_IDLE
2390 idle_period = (idle_period * HZ) / 100;
2391 if (idle_threshold < 100) {
2392 original_pm_idle = pm_idle;
2393 pm_idle = apm_cpu_idle;
2401 static void __exit apm_exit(void)
2405 #ifdef CONFIG_APM_CPU_IDLE
2407 pm_idle = original_pm_idle;
2409 * We are about to unload the current idle thread pm callback
2410 * (pm_idle), Wait for all processors to update cached/local
2411 * copies of pm_idle before proceeding.
2416 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2417 && (apm_info.connection_version > 0x0100)) {
2418 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2420 apm_error("disengage power management", error);
2422 misc_deregister(&apm_device);
2423 remove_proc_entry("apm", NULL);
2425 pm_power_off = NULL;
2427 kthread_stop(kapmd_task);
2432 module_init(apm_init);
2433 module_exit(apm_exit);
2435 MODULE_AUTHOR("Stephen Rothwell");
2436 MODULE_DESCRIPTION("Advanced Power Management");
2437 MODULE_LICENSE("GPL");
2438 module_param(debug, bool, 0644);
2439 MODULE_PARM_DESC(debug, "Enable debug mode");
2440 module_param(power_off, bool, 0444);
2441 MODULE_PARM_DESC(power_off, "Enable power off");
2442 module_param(bounce_interval, int, 0444);
2443 MODULE_PARM_DESC(bounce_interval,
2444 "Set the number of ticks to ignore suspend bounces");
2445 module_param(allow_ints, bool, 0444);
2446 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2447 module_param(broken_psr, bool, 0444);
2448 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2449 module_param(realmode_power_off, bool, 0444);
2450 MODULE_PARM_DESC(realmode_power_off,
2451 "Switch to real mode before powering off");
2452 #ifdef CONFIG_APM_CPU_IDLE
2453 module_param(idle_threshold, int, 0444);
2454 MODULE_PARM_DESC(idle_threshold,
2455 "System idle percentage above which to make APM BIOS idle calls");
2456 module_param(idle_period, int, 0444);
2457 MODULE_PARM_DESC(idle_period,
2458 "Period (in sec/100) over which to caculate the idle percentage");
2460 module_param(smp, bool, 0444);
2461 MODULE_PARM_DESC(smp,
2462 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2463 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);