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/system.h>
235 #include <asm/uaccess.h>
236 #include <asm/desc.h>
237 #include <asm/olpc.h>
238 #include <asm/paravirt.h>
239 #include <asm/reboot.h>
241 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
242 extern int (*console_blank_hook)(int);
246 * The apm_bios device is one of the misc char devices.
247 * This is its minor number.
249 #define APM_MINOR_DEV 134
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
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
264 * idle[-_]threshold=<n> System idle percentage above which to
265 * make APM BIOS idle calls. Set it to
267 * idle[-_]period=<n> Period (in 1/100s of a second) over
268 * which the idle percentage is
272 /* KNOWN PROBLEM MACHINES:
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
285 * Legend: U = unusable with APM patches
286 * P = partially usable with APM patches
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.
294 #define ALWAYS_CALL_BUSY 1
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).
301 #define APM_ZERO_SEGS
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>
310 #undef INIT_TIMER_AFTER_SUSPEND
312 #ifdef INIT_TIMER_AFTER_SUSPEND
313 #include <linux/timex.h>
315 #include <linux/delay.h>
319 * Need to poll the APM BIOS every second
321 #define APM_CHECK_TIMEOUT (HZ)
324 * Ignore suspend events for this amount of time after a resume
326 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
329 * Maximum number of events stored
331 #define APM_MAX_EVENTS 20
334 * The per-file APM data
338 struct apm_user *next;
339 unsigned int suser: 1;
340 unsigned int writer: 1;
341 unsigned int reader: 1;
342 unsigned int suspend_wait: 1;
344 int suspends_pending;
345 int standbys_pending;
350 apm_event_t events[APM_MAX_EVENTS];
354 * The magic number in apm_user
356 #define APM_BIOS_MAGIC 0x4101
359 * idle percentage above which bios idle calls are done
361 #ifdef CONFIG_APM_CPU_IDLE
362 #warning deprecated CONFIG_APM_CPU_IDLE will be deleted in 2012
363 #define DEFAULT_IDLE_THRESHOLD 95
365 #define DEFAULT_IDLE_THRESHOLD 100
367 #define DEFAULT_IDLE_PERIOD (100 / 3)
373 unsigned long offset;
374 unsigned short segment;
376 #ifdef CONFIG_APM_CPU_IDLE
377 static int clock_slowed;
378 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
379 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
380 static int set_pm_idle;
382 static int suspends_pending;
383 static int standbys_pending;
384 static int ignore_sys_suspend;
385 static int ignore_normal_resume;
386 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
388 static bool debug __read_mostly;
389 static bool smp __read_mostly;
390 static int apm_disabled = -1;
392 static bool power_off;
394 static bool power_off = 1;
396 static bool realmode_power_off;
397 #ifdef CONFIG_APM_ALLOW_INTS
398 static bool allow_ints = 1;
400 static bool allow_ints;
402 static bool broken_psr;
404 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
405 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
406 static struct apm_user *user_list;
407 static DEFINE_SPINLOCK(user_list_lock);
408 static DEFINE_MUTEX(apm_mutex);
411 * Set up a segment that references the real mode segment 0x40
412 * that extends up to the end of page zero (that we have reserved).
413 * This is for buggy BIOS's that refer to (real mode) segment 0x40
414 * even though they are called in protected mode.
416 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
417 (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
419 static const char driver_version[] = "1.16ac"; /* no spaces */
421 static struct task_struct *kapmd_task;
424 * APM event names taken from the APM 1.2 specification. These are
425 * the message codes that the BIOS uses to tell us about events
427 static const char * const apm_event_name[] = {
433 "power status change",
438 "system standby resume",
439 "capabilities change"
441 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
443 typedef struct lookup_t {
449 * The BIOS returns a set of standard error codes in AX when the
453 static const lookup_t error_table[] = {
454 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
455 { APM_DISABLED, "Power management disabled" },
456 { APM_CONNECTED, "Real mode interface already connected" },
457 { APM_NOT_CONNECTED, "Interface not connected" },
458 { APM_16_CONNECTED, "16 bit interface already connected" },
459 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
460 { APM_32_CONNECTED, "32 bit interface already connected" },
461 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
462 { APM_BAD_DEVICE, "Unrecognized device ID" },
463 { APM_BAD_PARAM, "Parameter out of range" },
464 { APM_NOT_ENGAGED, "Interface not engaged" },
465 { APM_BAD_FUNCTION, "Function not supported" },
466 { APM_RESUME_DISABLED, "Resume timer disabled" },
467 { APM_BAD_STATE, "Unable to enter requested state" },
468 /* N/A { APM_NO_EVENTS, "No events pending" }, */
469 { APM_NO_ERROR, "BIOS did not set a return code" },
470 { APM_NOT_PRESENT, "No APM present" }
472 #define ERROR_COUNT ARRAY_SIZE(error_table)
475 * apm_error - display an APM error
476 * @str: information string
477 * @err: APM BIOS return code
479 * Write a meaningful log entry to the kernel log in the event of
480 * an APM error. Note that this also handles (negative) kernel errors.
483 static void apm_error(char *str, int err)
487 for (i = 0; i < ERROR_COUNT; i++)
488 if (error_table[i].key == err)
491 printk(KERN_NOTICE "apm: %s: %s\n", str, error_table[i].msg);
493 printk(KERN_NOTICE "apm: %s: linux error code %i\n", str, err);
495 printk(KERN_NOTICE "apm: %s: unknown error code %#2.2x\n",
500 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
501 * apm_info.allow_ints, we are being really paranoid here! Not only
502 * are interrupts disabled, but all the segment registers (except SS)
503 * are saved and zeroed this means that if the BIOS tries to reference
504 * any data without explicitly loading the segment registers, the kernel
505 * will fault immediately rather than have some unforeseen circumstances
506 * for the rest of the kernel. And it will be very obvious! :-) Doing
507 * this depends on CS referring to the same physical memory as DS so that
508 * DS can be zeroed before the call. Unfortunately, we can't do anything
509 * about the stack segment/pointer. Also, we tell the compiler that
510 * everything could change.
512 * Also, we KNOW that for the non error case of apm_bios_call, there
513 * is no useful data returned in the low order 8 bits of eax.
516 static inline unsigned long __apm_irq_save(void)
519 local_save_flags(flags);
520 if (apm_info.allow_ints) {
521 if (irqs_disabled_flags(flags))
529 #define apm_irq_save(flags) \
530 do { flags = __apm_irq_save(); } while (0)
532 static inline void apm_irq_restore(unsigned long flags)
534 if (irqs_disabled_flags(flags))
536 else if (irqs_disabled())
541 # define APM_DECL_SEGS \
542 unsigned int saved_fs; unsigned int saved_gs;
543 # define APM_DO_SAVE_SEGS \
544 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
545 # define APM_DO_RESTORE_SEGS \
546 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
548 # define APM_DECL_SEGS
549 # define APM_DO_SAVE_SEGS
550 # define APM_DO_RESTORE_SEGS
553 struct apm_bios_call {
563 /* Error: -ENOMEM, or bits 8-15 of eax */
568 * __apm_bios_call - Make an APM BIOS 32bit call
569 * @_call: pointer to struct apm_bios_call.
571 * Make an APM call using the 32bit protected mode interface. The
572 * caller is responsible for knowing if APM BIOS is configured and
573 * enabled. This call can disable interrupts for a long period of
574 * time on some laptops. The return value is in AH and the carry
575 * flag is loaded into AL. If there is an error, then the error
576 * code is returned in AH (bits 8-15 of eax) and this function
579 * Note: this makes the call on the current CPU.
581 static long __apm_bios_call(void *_call)
586 struct desc_struct save_desc_40;
587 struct desc_struct *gdt;
588 struct apm_bios_call *call = _call;
592 gdt = get_cpu_gdt_table(cpu);
593 save_desc_40 = gdt[0x40 / 8];
594 gdt[0x40 / 8] = bad_bios_desc;
598 apm_bios_call_asm(call->func, call->ebx, call->ecx,
599 &call->eax, &call->ebx, &call->ecx, &call->edx,
602 apm_irq_restore(flags);
603 gdt[0x40 / 8] = save_desc_40;
606 return call->eax & 0xff;
609 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
610 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
614 /* Don't bother with work_on_cpu in the common case, so we don't
615 * have to worry about OOM or overhead. */
616 if (get_cpu() == 0) {
621 ret = work_on_cpu(0, fn, call);
624 /* work_on_cpu can fail with -ENOMEM */
628 call->err = (call->eax >> 8) & 0xff;
634 * apm_bios_call - Make an APM BIOS 32bit call (on CPU 0)
635 * @call: the apm_bios_call registers.
637 * If there is an error, it is returned in @call.err.
639 static int apm_bios_call(struct apm_bios_call *call)
641 return on_cpu0(__apm_bios_call, call);
645 * __apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
646 * @_call: pointer to struct apm_bios_call.
648 * Make a BIOS call that returns one value only, or just status.
649 * If there is an error, then the error code is returned in AH
650 * (bits 8-15 of eax) and this function returns non-zero (it can
651 * also return -ENOMEM). This is used for simpler BIOS operations.
652 * This call may hold interrupts off for a long time on some laptops.
654 * Note: this makes the call on the current CPU.
656 static long __apm_bios_call_simple(void *_call)
662 struct desc_struct save_desc_40;
663 struct desc_struct *gdt;
664 struct apm_bios_call *call = _call;
668 gdt = get_cpu_gdt_table(cpu);
669 save_desc_40 = gdt[0x40 / 8];
670 gdt[0x40 / 8] = bad_bios_desc;
674 error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
677 apm_irq_restore(flags);
678 gdt[0x40 / 8] = save_desc_40;
684 * apm_bios_call_simple - make a simple APM BIOS 32bit call
685 * @func: APM function to invoke
686 * @ebx_in: EBX register value for BIOS call
687 * @ecx_in: ECX register value for BIOS call
688 * @eax: EAX register on return from the BIOS call
691 * Make a BIOS call that returns one value only, or just status.
692 * If there is an error, then the error code is returned in @err
693 * and this function returns non-zero. This is used for simpler
694 * BIOS operations. This call may hold interrupts off for a long
695 * time on some laptops.
697 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
700 struct apm_bios_call call;
707 ret = on_cpu0(__apm_bios_call_simple, &call);
714 * apm_driver_version - APM driver version
715 * @val: loaded with the APM version on return
717 * Retrieve the APM version supported by the BIOS. This is only
718 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
721 * On entry val should point to a value indicating the APM driver
722 * version with the high byte being the major and the low byte the
723 * minor number both in BCD
725 * On return it will hold the BIOS revision supported in the
729 static int apm_driver_version(u_short *val)
734 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
741 * apm_get_event - get an APM event from the BIOS
742 * @event: pointer to the event
743 * @info: point to the event information
745 * The APM BIOS provides a polled information for event
746 * reporting. The BIOS expects to be polled at least every second
747 * when events are pending. When a message is found the caller should
748 * poll until no more messages are present. However, this causes
749 * problems on some laptops where a suspend event notification is
750 * not cleared until it is acknowledged.
752 * Additional information is returned in the info pointer, providing
753 * that APM 1.2 is in use. If no messges are pending the value 0x80
754 * is returned (No power management events pending).
756 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
758 struct apm_bios_call call;
760 call.func = APM_FUNC_GET_EVENT;
761 call.ebx = call.ecx = 0;
763 if (apm_bios_call(&call))
767 if (apm_info.connection_version < 0x0102)
768 *info = ~0; /* indicate info not valid */
775 * set_power_state - set the power management state
776 * @what: which items to transition
777 * @state: state to transition to
779 * Request an APM change of state for one or more system devices. The
780 * processor state must be transitioned last of all. what holds the
781 * class of device in the upper byte and the device number (0xFF for
782 * all) for the object to be transitioned.
784 * The state holds the state to transition to, which may in fact
785 * be an acceptance of a BIOS requested state change.
788 static int set_power_state(u_short what, u_short state)
793 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
799 * set_system_power_state - set system wide power state
800 * @state: which state to enter
802 * Transition the entire system into a new APM power state.
805 static int set_system_power_state(u_short state)
807 return set_power_state(APM_DEVICE_ALL, state);
810 #ifdef CONFIG_APM_CPU_IDLE
812 * apm_do_idle - perform power saving
814 * This function notifies the BIOS that the processor is (in the view
815 * of the OS) idle. It returns -1 in the event that the BIOS refuses
816 * to handle the idle request. On a success the function returns 1
817 * if the BIOS did clock slowing or 0 otherwise.
820 static int apm_do_idle(void)
828 polling = !!(current_thread_info()->status & TS_POLLING);
830 current_thread_info()->status &= ~TS_POLLING;
832 * TS_POLLING-cleared state must be visible before we
837 if (!need_resched()) {
839 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
842 current_thread_info()->status |= TS_POLLING;
848 static unsigned long t;
850 /* This always fails on some SMP boards running UP kernels.
851 * Only report the failure the first 5 times.
854 printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
859 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
864 * apm_do_busy - inform the BIOS the CPU is busy
866 * Request that the BIOS brings the CPU back to full performance.
869 static void apm_do_busy(void)
874 if (clock_slowed || ALWAYS_CALL_BUSY) {
875 (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
881 * If no process has really been interested in
882 * the CPU for some time, we want to call BIOS
883 * power management - we probably want
886 #define IDLE_CALC_LIMIT (HZ * 100)
887 #define IDLE_LEAKY_MAX 16
889 static void (*original_pm_idle)(void) __read_mostly;
892 * apm_cpu_idle - cpu idling for APM capable Linux
894 * This is the idling function the kernel executes when APM is available. It
895 * tries to do BIOS powermanagement based on the average system idle time.
896 * Furthermore it calls the system default idle routine.
899 static void apm_cpu_idle(void)
901 static int use_apm_idle; /* = 0 */
902 static unsigned int last_jiffies; /* = 0 */
903 static unsigned int last_stime; /* = 0 */
905 int apm_idle_done = 0;
906 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
909 WARN_ONCE(1, "deprecated apm_cpu_idle will be deleted in 2012");
911 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
913 last_jiffies = jiffies;
914 last_stime = current->stime;
915 } else if (jiffies_since_last_check > idle_period) {
916 unsigned int idle_percentage;
918 idle_percentage = current->stime - last_stime;
919 idle_percentage *= 100;
920 idle_percentage /= jiffies_since_last_check;
921 use_apm_idle = (idle_percentage > idle_threshold);
922 if (apm_info.forbid_idle)
924 last_jiffies = jiffies;
925 last_stime = current->stime;
928 bucket = IDLE_LEAKY_MAX;
930 while (!need_resched()) {
935 switch (apm_do_idle()) {
940 bucket = IDLE_LEAKY_MAX;
951 default: /* BIOS refused */
955 if (original_pm_idle)
960 jiffies_since_last_check = jiffies - last_jiffies;
961 if (jiffies_since_last_check > idle_period)
973 * apm_power_off - ask the BIOS to power off
975 * Handle the power off sequence. This is the one piece of code we
976 * will execute even on SMP machines. In order to deal with BIOS
977 * bugs we support real mode APM BIOS power off calls. We also make
978 * the SMP call on CPU0 as some systems will only honour this call
979 * on their first cpu.
982 static void apm_power_off(void)
984 /* Some bioses don't like being called from CPU != 0 */
985 if (apm_info.realmode_power_off) {
986 set_cpus_allowed_ptr(current, cpumask_of(0));
987 machine_real_restart(MRR_APM);
989 (void)set_system_power_state(APM_STATE_OFF);
993 #ifdef CONFIG_APM_DO_ENABLE
996 * apm_enable_power_management - enable BIOS APM power management
997 * @enable: enable yes/no
999 * Enable or disable the APM BIOS power services.
1002 static int apm_enable_power_management(int enable)
1007 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1008 return APM_NOT_ENGAGED;
1009 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1010 enable, &eax, &err))
1013 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1015 apm_info.bios.flags |= APM_BIOS_DISABLED;
1021 * apm_get_power_status - get current power state
1022 * @status: returned status
1023 * @bat: battery info
1024 * @life: estimated life
1026 * Obtain the current power status from the APM BIOS. We return a
1027 * status which gives the rough battery status, and current power
1028 * source. The bat value returned give an estimate as a percentage
1029 * of life and a status value for the battery. The estimated life
1030 * if reported is a lifetime in secodnds/minutes at current powwer
1034 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1036 struct apm_bios_call call;
1038 call.func = APM_FUNC_GET_STATUS;
1039 call.ebx = APM_DEVICE_ALL;
1042 if (apm_info.get_power_status_broken)
1043 return APM_32_UNSUPPORTED;
1044 if (apm_bios_call(&call))
1048 if (apm_info.get_power_status_swabinminutes) {
1049 *life = swab16((u16)call.edx);
1057 static int apm_get_battery_status(u_short which, u_short *status,
1058 u_short *bat, u_short *life, u_short *nbat)
1066 if (apm_info.connection_version < 0x0102) {
1067 /* pretend we only have one battery. */
1069 return APM_BAD_DEVICE;
1071 return apm_get_power_status(status, bat, life);
1074 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1075 &ebx, &ecx, &edx, &esi))
1076 return (eax >> 8) & 0xff;
1086 * apm_engage_power_management - enable PM on a device
1087 * @device: identity of device
1090 * Activate or deactive power management on either a specific device
1091 * or the entire system (%APM_DEVICE_ALL).
1094 static int apm_engage_power_management(u_short device, int enable)
1099 if ((enable == 0) && (device == APM_DEVICE_ALL)
1100 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1101 return APM_DISABLED;
1102 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1105 if (device == APM_DEVICE_ALL) {
1107 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1109 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1114 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1117 * apm_console_blank - blank the display
1120 * Attempt to blank the console, firstly by blanking just video device
1121 * zero, and if that fails (some BIOSes don't support it) then it blanks
1122 * all video devices. Typically the BIOS will do laptop backlight and
1123 * monitor powerdown for us.
1126 static int apm_console_blank(int blank)
1128 int error = APM_NOT_ENGAGED; /* silence gcc */
1131 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1133 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1135 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1136 error = set_power_state(dev[i], state);
1138 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1141 if (error == APM_NOT_ENGAGED)
1145 if (error == APM_NOT_ENGAGED) {
1149 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1151 apm_error("set display", error);
1152 apm_error("engage interface", eng_error);
1155 return apm_console_blank(blank);
1158 apm_error("set display", error);
1163 static int queue_empty(struct apm_user *as)
1165 return as->event_head == as->event_tail;
1168 static apm_event_t get_queued_event(struct apm_user *as)
1170 if (++as->event_tail >= APM_MAX_EVENTS)
1172 return as->events[as->event_tail];
1175 static void queue_event(apm_event_t event, struct apm_user *sender)
1177 struct apm_user *as;
1179 spin_lock(&user_list_lock);
1180 if (user_list == NULL)
1182 for (as = user_list; as != NULL; as = as->next) {
1183 if ((as == sender) || (!as->reader))
1185 if (++as->event_head >= APM_MAX_EVENTS)
1188 if (as->event_head == as->event_tail) {
1189 static int notified;
1191 if (notified++ == 0)
1192 printk(KERN_ERR "apm: an event queue overflowed\n");
1193 if (++as->event_tail >= APM_MAX_EVENTS)
1196 as->events[as->event_head] = event;
1197 if (!as->suser || !as->writer)
1200 case APM_SYS_SUSPEND:
1201 case APM_USER_SUSPEND:
1202 as->suspends_pending++;
1206 case APM_SYS_STANDBY:
1207 case APM_USER_STANDBY:
1208 as->standbys_pending++;
1213 wake_up_interruptible(&apm_waitqueue);
1215 spin_unlock(&user_list_lock);
1218 static void reinit_timer(void)
1220 #ifdef INIT_TIMER_AFTER_SUSPEND
1221 unsigned long flags;
1223 raw_spin_lock_irqsave(&i8253_lock, flags);
1224 /* set the clock to HZ */
1225 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1227 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1229 outb_p(LATCH >> 8, PIT_CH0); /* MSB */
1231 raw_spin_unlock_irqrestore(&i8253_lock, flags);
1235 static int suspend(int vetoable)
1238 struct apm_user *as;
1240 dpm_suspend_start(PMSG_SUSPEND);
1242 dpm_suspend_noirq(PMSG_SUSPEND);
1244 local_irq_disable();
1249 save_processor_state();
1250 err = set_system_power_state(APM_STATE_SUSPEND);
1251 ignore_normal_resume = 1;
1252 restore_processor_state();
1254 local_irq_disable();
1257 if (err == APM_NO_ERROR)
1259 if (err != APM_SUCCESS)
1260 apm_error("suspend", err);
1261 err = (err == APM_SUCCESS) ? 0 : -EIO;
1266 dpm_resume_noirq(PMSG_RESUME);
1268 dpm_resume_end(PMSG_RESUME);
1269 queue_event(APM_NORMAL_RESUME, NULL);
1270 spin_lock(&user_list_lock);
1271 for (as = user_list; as != NULL; as = as->next) {
1272 as->suspend_wait = 0;
1273 as->suspend_result = err;
1275 spin_unlock(&user_list_lock);
1276 wake_up_interruptible(&apm_suspend_waitqueue);
1280 static void standby(void)
1284 dpm_suspend_noirq(PMSG_SUSPEND);
1286 local_irq_disable();
1290 err = set_system_power_state(APM_STATE_STANDBY);
1291 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1292 apm_error("standby", err);
1294 local_irq_disable();
1298 dpm_resume_noirq(PMSG_RESUME);
1301 static apm_event_t get_event(void)
1304 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1305 apm_eventinfo_t info;
1307 static int notified;
1309 /* we don't use the eventinfo */
1310 error = apm_get_event(&event, &info);
1311 if (error == APM_SUCCESS)
1314 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1315 apm_error("get_event", error);
1320 static void check_events(void)
1323 static unsigned long last_resume;
1324 static int ignore_bounce;
1326 while ((event = get_event()) != 0) {
1328 if (event <= NR_APM_EVENT_NAME)
1329 printk(KERN_DEBUG "apm: received %s notify\n",
1330 apm_event_name[event - 1]);
1332 printk(KERN_DEBUG "apm: received unknown "
1333 "event 0x%02x\n", event);
1336 && (time_after(jiffies, last_resume + bounce_interval)))
1340 case APM_SYS_STANDBY:
1341 case APM_USER_STANDBY:
1342 queue_event(event, NULL);
1343 if (standbys_pending <= 0)
1347 case APM_USER_SUSPEND:
1348 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1349 if (apm_info.connection_version > 0x100)
1350 set_system_power_state(APM_STATE_REJECT);
1353 case APM_SYS_SUSPEND:
1354 if (ignore_bounce) {
1355 if (apm_info.connection_version > 0x100)
1356 set_system_power_state(APM_STATE_REJECT);
1360 * If we are already processing a SUSPEND,
1361 * then further SUSPEND events from the BIOS
1362 * will be ignored. We also return here to
1363 * cope with the fact that the Thinkpads keep
1364 * sending a SUSPEND event until something else
1367 if (ignore_sys_suspend)
1369 ignore_sys_suspend = 1;
1370 queue_event(event, NULL);
1371 if (suspends_pending <= 0)
1375 case APM_NORMAL_RESUME:
1376 case APM_CRITICAL_RESUME:
1377 case APM_STANDBY_RESUME:
1378 ignore_sys_suspend = 0;
1379 last_resume = jiffies;
1381 if ((event != APM_NORMAL_RESUME)
1382 || (ignore_normal_resume == 0)) {
1383 dpm_resume_end(PMSG_RESUME);
1384 queue_event(event, NULL);
1386 ignore_normal_resume = 0;
1389 case APM_CAPABILITY_CHANGE:
1390 case APM_LOW_BATTERY:
1391 case APM_POWER_STATUS_CHANGE:
1392 queue_event(event, NULL);
1393 /* If needed, notify drivers here */
1396 case APM_UPDATE_TIME:
1399 case APM_CRITICAL_SUSPEND:
1401 * We are not allowed to reject a critical suspend.
1409 static void apm_event_handler(void)
1411 static int pending_count = 4;
1414 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1415 if ((apm_info.connection_version > 0x100) &&
1416 (pending_count-- <= 0)) {
1419 printk(KERN_DEBUG "apm: setting state busy\n");
1420 err = set_system_power_state(APM_STATE_BUSY);
1422 apm_error("busy", err);
1430 * This is the APM thread main loop.
1433 static void apm_mainloop(void)
1435 DECLARE_WAITQUEUE(wait, current);
1437 add_wait_queue(&apm_waitqueue, &wait);
1438 set_current_state(TASK_INTERRUPTIBLE);
1440 schedule_timeout(APM_CHECK_TIMEOUT);
1441 if (kthread_should_stop())
1444 * Ok, check all events, check for idle (and mark us sleeping
1445 * so as not to count towards the load average)..
1447 set_current_state(TASK_INTERRUPTIBLE);
1448 apm_event_handler();
1450 remove_wait_queue(&apm_waitqueue, &wait);
1453 static int check_apm_user(struct apm_user *as, const char *func)
1455 if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1456 printk(KERN_ERR "apm: %s passed bad filp\n", func);
1462 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1464 struct apm_user *as;
1468 as = fp->private_data;
1469 if (check_apm_user(as, "read"))
1471 if ((int)count < sizeof(apm_event_t))
1473 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1475 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1477 while ((i >= sizeof(event)) && !queue_empty(as)) {
1478 event = get_queued_event(as);
1479 if (copy_to_user(buf, &event, sizeof(event))) {
1485 case APM_SYS_SUSPEND:
1486 case APM_USER_SUSPEND:
1487 as->suspends_read++;
1490 case APM_SYS_STANDBY:
1491 case APM_USER_STANDBY:
1492 as->standbys_read++;
1495 buf += sizeof(event);
1500 if (signal_pending(current))
1501 return -ERESTARTSYS;
1505 static unsigned int do_poll(struct file *fp, poll_table *wait)
1507 struct apm_user *as;
1509 as = fp->private_data;
1510 if (check_apm_user(as, "poll"))
1512 poll_wait(fp, &apm_waitqueue, wait);
1513 if (!queue_empty(as))
1514 return POLLIN | POLLRDNORM;
1518 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1520 struct apm_user *as;
1523 as = filp->private_data;
1524 if (check_apm_user(as, "ioctl"))
1526 if (!as->suser || !as->writer)
1529 case APM_IOC_STANDBY:
1530 mutex_lock(&apm_mutex);
1531 if (as->standbys_read > 0) {
1532 as->standbys_read--;
1533 as->standbys_pending--;
1536 queue_event(APM_USER_STANDBY, as);
1537 if (standbys_pending <= 0)
1539 mutex_unlock(&apm_mutex);
1541 case APM_IOC_SUSPEND:
1542 mutex_lock(&apm_mutex);
1543 if (as->suspends_read > 0) {
1544 as->suspends_read--;
1545 as->suspends_pending--;
1548 queue_event(APM_USER_SUSPEND, as);
1549 if (suspends_pending <= 0) {
1551 mutex_unlock(&apm_mutex);
1553 as->suspend_wait = 1;
1554 mutex_unlock(&apm_mutex);
1555 wait_event_interruptible(apm_suspend_waitqueue,
1556 as->suspend_wait == 0);
1557 ret = as->suspend_result;
1566 static int do_release(struct inode *inode, struct file *filp)
1568 struct apm_user *as;
1570 as = filp->private_data;
1571 if (check_apm_user(as, "release"))
1573 filp->private_data = NULL;
1574 if (as->standbys_pending > 0) {
1575 standbys_pending -= as->standbys_pending;
1576 if (standbys_pending <= 0)
1579 if (as->suspends_pending > 0) {
1580 suspends_pending -= as->suspends_pending;
1581 if (suspends_pending <= 0)
1584 spin_lock(&user_list_lock);
1585 if (user_list == as)
1586 user_list = as->next;
1588 struct apm_user *as1;
1590 for (as1 = user_list;
1591 (as1 != NULL) && (as1->next != as);
1595 printk(KERN_ERR "apm: filp not in user list\n");
1597 as1->next = as->next;
1599 spin_unlock(&user_list_lock);
1604 static int do_open(struct inode *inode, struct file *filp)
1606 struct apm_user *as;
1608 as = kmalloc(sizeof(*as), GFP_KERNEL);
1610 printk(KERN_ERR "apm: cannot allocate struct of size %d bytes\n",
1614 as->magic = APM_BIOS_MAGIC;
1615 as->event_tail = as->event_head = 0;
1616 as->suspends_pending = as->standbys_pending = 0;
1617 as->suspends_read = as->standbys_read = 0;
1619 * XXX - this is a tiny bit broken, when we consider BSD
1620 * process accounting. If the device is opened by root, we
1621 * instantly flag that we used superuser privs. Who knows,
1622 * we might close the device immediately without doing a
1623 * privileged operation -- cevans
1625 as->suser = capable(CAP_SYS_ADMIN);
1626 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1627 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1628 spin_lock(&user_list_lock);
1629 as->next = user_list;
1631 spin_unlock(&user_list_lock);
1632 filp->private_data = as;
1636 static int proc_apm_show(struct seq_file *m, void *v)
1642 unsigned short ac_line_status = 0xff;
1643 unsigned short battery_status = 0xff;
1644 unsigned short battery_flag = 0xff;
1645 int percentage = -1;
1646 int time_units = -1;
1649 if ((num_online_cpus() == 1) &&
1650 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1651 ac_line_status = (bx >> 8) & 0xff;
1652 battery_status = bx & 0xff;
1653 if ((cx & 0xff) != 0xff)
1654 percentage = cx & 0xff;
1656 if (apm_info.connection_version > 0x100) {
1657 battery_flag = (cx >> 8) & 0xff;
1659 units = (dx & 0x8000) ? "min" : "sec";
1660 time_units = dx & 0x7fff;
1664 /* Arguments, with symbols from linux/apm_bios.h. Information is
1665 from the Get Power Status (0x0a) call unless otherwise noted.
1667 0) Linux driver version (this will change if format changes)
1668 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1669 2) APM flags from APM Installation Check (0x00):
1670 bit 0: APM_16_BIT_SUPPORT
1671 bit 1: APM_32_BIT_SUPPORT
1672 bit 2: APM_IDLE_SLOWS_CLOCK
1673 bit 3: APM_BIOS_DISABLED
1674 bit 4: APM_BIOS_DISENGAGED
1678 0x02: On backup power (BIOS >= 1.1 only)
1685 0x04: Selected battery not present (BIOS >= 1.2 only)
1692 bit 7: No system battery
1694 6) Remaining battery life (percentage of charge):
1697 7) Remaining battery life (time units):
1698 Number of remaining minutes or seconds
1700 8) min = minutes; sec = seconds */
1702 seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1704 (apm_info.bios.version >> 8) & 0xff,
1705 apm_info.bios.version & 0xff,
1706 apm_info.bios.flags,
1716 static int proc_apm_open(struct inode *inode, struct file *file)
1718 return single_open(file, proc_apm_show, NULL);
1721 static const struct file_operations apm_file_ops = {
1722 .owner = THIS_MODULE,
1723 .open = proc_apm_open,
1725 .llseek = seq_lseek,
1726 .release = single_release,
1729 static int apm(void *unused)
1739 * This is to avoid random crashes at boot time during initialization
1740 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1741 * Some bioses don't like being called from CPU != 0.
1742 * Method suggested by Ingo Molnar.
1744 set_cpus_allowed_ptr(current, cpumask_of(0));
1745 BUG_ON(smp_processor_id() != 0);
1747 if (apm_info.connection_version == 0) {
1748 apm_info.connection_version = apm_info.bios.version;
1749 if (apm_info.connection_version > 0x100) {
1751 * We only support BIOSs up to version 1.2
1753 if (apm_info.connection_version > 0x0102)
1754 apm_info.connection_version = 0x0102;
1755 error = apm_driver_version(&apm_info.connection_version);
1756 if (error != APM_SUCCESS) {
1757 apm_error("driver version", error);
1758 /* Fall back to an APM 1.0 connection. */
1759 apm_info.connection_version = 0x100;
1765 printk(KERN_INFO "apm: Connection version %d.%d\n",
1766 (apm_info.connection_version >> 8) & 0xff,
1767 apm_info.connection_version & 0xff);
1769 #ifdef CONFIG_APM_DO_ENABLE
1770 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1772 * This call causes my NEC UltraLite Versa 33/C to hang if it
1773 * is booted with PM disabled but not in the docking station.
1776 error = apm_enable_power_management(1);
1778 apm_error("enable power management", error);
1784 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1785 && (apm_info.connection_version > 0x0100)) {
1786 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1788 apm_error("engage power management", error);
1793 if (debug && (num_online_cpus() == 1 || smp)) {
1794 error = apm_get_power_status(&bx, &cx, &dx);
1796 printk(KERN_INFO "apm: power status not available\n");
1798 switch ((bx >> 8) & 0xff) {
1800 power_stat = "off line";
1803 power_stat = "on line";
1806 power_stat = "on backup power";
1809 power_stat = "unknown";
1812 switch (bx & 0xff) {
1820 bat_stat = "critical";
1823 bat_stat = "charging";
1826 bat_stat = "unknown";
1830 "apm: AC %s, battery status %s, battery life ",
1831 power_stat, bat_stat);
1832 if ((cx & 0xff) == 0xff)
1833 printk("unknown\n");
1835 printk("%d%%\n", cx & 0xff);
1836 if (apm_info.connection_version > 0x100) {
1838 "apm: battery flag 0x%02x, battery life ",
1841 printk("unknown\n");
1843 printk("%d %s\n", dx & 0x7fff,
1845 "minutes" : "seconds");
1850 /* Install our power off handler.. */
1852 pm_power_off = apm_power_off;
1854 if (num_online_cpus() == 1 || smp) {
1855 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1856 console_blank_hook = apm_console_blank;
1859 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1860 console_blank_hook = NULL;
1868 static int __init apm_setup(char *str)
1872 while ((str != NULL) && (*str != '\0')) {
1873 if (strncmp(str, "off", 3) == 0)
1875 if (strncmp(str, "on", 2) == 0)
1877 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1878 (strncmp(str, "bounce_interval=", 16) == 0))
1879 bounce_interval = simple_strtol(str + 16, NULL, 0);
1880 #ifdef CONFIG_APM_CPU_IDLE
1881 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1882 (strncmp(str, "idle_threshold=", 15) == 0))
1883 idle_threshold = simple_strtol(str + 15, NULL, 0);
1884 if ((strncmp(str, "idle-period=", 12) == 0) ||
1885 (strncmp(str, "idle_period=", 12) == 0))
1886 idle_period = simple_strtol(str + 12, NULL, 0);
1888 invert = (strncmp(str, "no-", 3) == 0) ||
1889 (strncmp(str, "no_", 3) == 0);
1892 if (strncmp(str, "debug", 5) == 0)
1894 if ((strncmp(str, "power-off", 9) == 0) ||
1895 (strncmp(str, "power_off", 9) == 0))
1896 power_off = !invert;
1897 if (strncmp(str, "smp", 3) == 0) {
1899 idle_threshold = 100;
1901 if ((strncmp(str, "allow-ints", 10) == 0) ||
1902 (strncmp(str, "allow_ints", 10) == 0))
1903 apm_info.allow_ints = !invert;
1904 if ((strncmp(str, "broken-psr", 10) == 0) ||
1905 (strncmp(str, "broken_psr", 10) == 0))
1906 apm_info.get_power_status_broken = !invert;
1907 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1908 (strncmp(str, "realmode_power_off", 18) == 0))
1909 apm_info.realmode_power_off = !invert;
1910 str = strchr(str, ',');
1912 str += strspn(str, ", \t");
1917 __setup("apm=", apm_setup);
1920 static const struct file_operations apm_bios_fops = {
1921 .owner = THIS_MODULE,
1924 .unlocked_ioctl = do_ioctl,
1926 .release = do_release,
1927 .llseek = noop_llseek,
1930 static struct miscdevice apm_device = {
1937 /* Simple "print if true" callback */
1938 static int __init print_if_true(const struct dmi_system_id *d)
1940 printk("%s\n", d->ident);
1945 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1946 * disabled before the suspend. Linux used to get terribly confused by that.
1948 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1950 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1951 "workaround hopefully not needed.\n", d->ident);
1955 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1956 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1958 if (apm_info.realmode_power_off == 0) {
1959 apm_info.realmode_power_off = 1;
1960 printk(KERN_INFO "%s bios detected. "
1961 "Using realmode poweroff only.\n", d->ident);
1966 /* Some laptops require interrupts to be enabled during APM calls */
1967 static int __init set_apm_ints(const struct dmi_system_id *d)
1969 if (apm_info.allow_ints == 0) {
1970 apm_info.allow_ints = 1;
1971 printk(KERN_INFO "%s machine detected. "
1972 "Enabling interrupts during APM calls.\n", d->ident);
1977 /* Some APM bioses corrupt memory or just plain do not work */
1978 static int __init apm_is_horked(const struct dmi_system_id *d)
1980 if (apm_info.disabled == 0) {
1981 apm_info.disabled = 1;
1982 printk(KERN_INFO "%s machine detected. "
1983 "Disabling APM.\n", d->ident);
1988 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1990 if (apm_info.disabled == 0) {
1991 apm_info.disabled = 1;
1992 printk(KERN_INFO "%s machine detected. "
1993 "Disabling APM.\n", d->ident);
1994 printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1995 printk(KERN_INFO "download from support.intel.com\n");
2000 /* Some APM bioses hang on APM idle calls */
2001 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
2003 if (apm_info.forbid_idle == 0) {
2004 apm_info.forbid_idle = 1;
2005 printk(KERN_INFO "%s machine detected. "
2006 "Disabling APM idle calls.\n", d->ident);
2012 * Check for clue free BIOS implementations who use
2013 * the following QA technique
2015 * [ Write BIOS Code ]<------
2017 * < Does it Compile >----N--
2019 * < Does it Boot Win98 >-N--
2023 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
2024 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
2026 static int __init broken_apm_power(const struct dmi_system_id *d)
2028 apm_info.get_power_status_broken = 1;
2029 printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2030 "disabling power status reporting.\n");
2035 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2036 * have this problem).
2038 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2040 apm_info.get_power_status_swabinminutes = 1;
2041 printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2042 "in minutes and wrong byte order.\n");
2046 static struct dmi_system_id __initdata apm_dmi_table[] = {
2049 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2050 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2051 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2053 { /* Handle problems with APM on the C600 */
2054 broken_ps2_resume, "Dell Latitude C600",
2055 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2056 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2058 { /* Allow interrupts during suspend on Dell Latitude laptops*/
2059 set_apm_ints, "Dell Latitude",
2060 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2061 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2064 apm_is_horked, "Dell Inspiron 2500",
2065 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2066 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2067 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2068 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2070 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
2071 set_apm_ints, "Dell Inspiron", {
2072 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2073 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2075 { /* Handle problems with APM on Inspiron 5000e */
2076 broken_apm_power, "Dell Inspiron 5000e",
2077 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2078 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2079 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2081 { /* Handle problems with APM on Inspiron 2500 */
2082 broken_apm_power, "Dell Inspiron 2500",
2083 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2084 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2085 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2088 apm_is_horked, "Dell Dimension 4100",
2089 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2090 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2091 DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2092 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2094 { /* Allow interrupts during suspend on Compaq Laptops*/
2095 set_apm_ints, "Compaq 12XL125",
2096 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2097 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2098 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2099 DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2101 { /* Allow interrupts during APM or the clock goes slow */
2102 set_apm_ints, "ASUSTeK",
2103 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2104 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2106 { /* APM blows on shutdown */
2107 apm_is_horked, "ABIT KX7-333[R]",
2108 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2109 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2112 apm_is_horked, "Trigem Delhi3",
2113 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2114 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2117 apm_is_horked, "Fujitsu-Siemens",
2118 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2119 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2122 apm_is_horked_d850md, "Intel D850MD",
2123 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2124 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2127 apm_is_horked, "Intel D810EMO",
2128 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2129 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2132 apm_is_horked, "Dell XPS-Z",
2133 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2134 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2135 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2138 apm_is_horked, "Sharp PC-PJ/AX",
2139 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2140 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2141 DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2142 DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2145 apm_is_horked, "Dell Inspiron 2500",
2146 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2147 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2148 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2149 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2151 { /* APM idle hangs */
2152 apm_likes_to_melt, "Jabil AMD",
2153 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2154 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2156 { /* APM idle hangs */
2157 apm_likes_to_melt, "AMI Bios",
2158 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2159 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2161 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2162 swab_apm_power_in_minutes, "Sony VAIO",
2163 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2164 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2165 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2167 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2168 swab_apm_power_in_minutes, "Sony VAIO",
2169 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2170 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2171 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2173 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2174 swab_apm_power_in_minutes, "Sony VAIO",
2175 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2176 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2177 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
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, "R0121Z1"),
2183 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2185 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2186 swab_apm_power_in_minutes, "Sony VAIO",
2187 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2188 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2189 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2191 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2192 swab_apm_power_in_minutes, "Sony VAIO",
2193 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2194 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2195 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
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, "R0203D0"),
2201 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2203 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2204 swab_apm_power_in_minutes, "Sony VAIO",
2205 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2206 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2207 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2209 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2210 swab_apm_power_in_minutes, "Sony VAIO",
2211 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2212 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2213 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2215 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2216 swab_apm_power_in_minutes, "Sony VAIO",
2217 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2218 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2219 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2222 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2223 swab_apm_power_in_minutes, "Sony VAIO",
2224 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2225 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2226 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
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, "R0204P1"),
2232 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2234 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2235 swab_apm_power_in_minutes, "Sony VAIO",
2236 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2237 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2238 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2240 { /* broken PM poweroff bios */
2241 set_realmode_power_off, "Award Software v4.60 PGMA",
2242 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2243 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2244 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2247 /* Generic per vendor APM settings */
2249 { /* Allow interrupts during suspend on IBM laptops */
2250 set_apm_ints, "IBM",
2251 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2258 * Just start the APM thread. We do NOT want to do APM BIOS
2259 * calls from anything but the APM thread, if for no other reason
2260 * than the fact that we don't trust the APM BIOS. This way,
2261 * most common APM BIOS problems that lead to protection errors
2262 * etc will have at least some level of being contained...
2264 * In short, if something bad happens, at least we have a choice
2265 * of just killing the apm thread..
2267 static int __init apm_init(void)
2269 struct desc_struct *gdt;
2272 dmi_check_system(apm_dmi_table);
2274 if (apm_info.bios.version == 0 || paravirt_enabled() || machine_is_olpc()) {
2275 printk(KERN_INFO "apm: BIOS not found.\n");
2279 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2280 ((apm_info.bios.version >> 8) & 0xff),
2281 (apm_info.bios.version & 0xff),
2282 apm_info.bios.flags,
2284 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2285 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2290 apm_info.allow_ints = 1;
2292 apm_info.get_power_status_broken = 1;
2293 if (realmode_power_off)
2294 apm_info.realmode_power_off = 1;
2295 /* User can override, but default is to trust DMI */
2296 if (apm_disabled != -1)
2297 apm_info.disabled = apm_disabled;
2300 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2301 * but is reportedly a 1.0 BIOS.
2303 if (apm_info.bios.version == 0x001)
2304 apm_info.bios.version = 0x100;
2306 /* BIOS < 1.2 doesn't set cseg_16_len */
2307 if (apm_info.bios.version < 0x102)
2308 apm_info.bios.cseg_16_len = 0; /* 64k */
2311 printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2312 apm_info.bios.cseg, apm_info.bios.offset,
2313 apm_info.bios.cseg_16, apm_info.bios.dseg);
2314 if (apm_info.bios.version > 0x100)
2315 printk(" cseg len %x, dseg len %x",
2316 apm_info.bios.cseg_len,
2317 apm_info.bios.dseg_len);
2318 if (apm_info.bios.version > 0x101)
2319 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2323 if (apm_info.disabled) {
2324 printk(KERN_NOTICE "apm: disabled on user request.\n");
2327 if ((num_online_cpus() > 1) && !power_off && !smp) {
2328 printk(KERN_NOTICE "apm: disabled - APM is not SMP safe.\n");
2329 apm_info.disabled = 1;
2332 if (!acpi_disabled) {
2333 printk(KERN_NOTICE "apm: overridden by ACPI.\n");
2334 apm_info.disabled = 1;
2339 * Set up the long jump entry point to the APM BIOS, which is called
2340 * from inline assembly.
2342 apm_bios_entry.offset = apm_info.bios.offset;
2343 apm_bios_entry.segment = APM_CS;
2346 * The APM 1.1 BIOS is supposed to provide limit information that it
2347 * recognizes. Many machines do this correctly, but many others do
2348 * not restrict themselves to their claimed limit. When this happens,
2349 * they will cause a segmentation violation in the kernel at boot time.
2350 * Most BIOS's, however, will respect a 64k limit, so we use that.
2352 * Note we only set APM segments on CPU zero, since we pin the APM
2355 gdt = get_cpu_gdt_table(0);
2356 set_desc_base(&gdt[APM_CS >> 3],
2357 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2358 set_desc_base(&gdt[APM_CS_16 >> 3],
2359 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2360 set_desc_base(&gdt[APM_DS >> 3],
2361 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2363 proc_create("apm", 0, NULL, &apm_file_ops);
2365 kapmd_task = kthread_create(apm, NULL, "kapmd");
2366 if (IS_ERR(kapmd_task)) {
2367 printk(KERN_ERR "apm: disabled - Unable to start kernel "
2369 err = PTR_ERR(kapmd_task);
2371 remove_proc_entry("apm", NULL);
2374 wake_up_process(kapmd_task);
2376 if (num_online_cpus() > 1 && !smp) {
2378 "apm: disabled - APM is not SMP safe (power off active).\n");
2383 * Note we don't actually care if the misc_device cannot be registered.
2384 * this driver can do its job without it, even if userspace can't
2385 * control it. just log the error
2387 if (misc_register(&apm_device))
2388 printk(KERN_WARNING "apm: Could not register misc device.\n");
2390 #ifdef CONFIG_APM_CPU_IDLE
2392 idle_period = (idle_period * HZ) / 100;
2393 if (idle_threshold < 100) {
2394 original_pm_idle = pm_idle;
2395 pm_idle = apm_cpu_idle;
2403 static void __exit apm_exit(void)
2407 #ifdef CONFIG_APM_CPU_IDLE
2409 pm_idle = original_pm_idle;
2411 * We are about to unload the current idle thread pm callback
2412 * (pm_idle), Wait for all processors to update cached/local
2413 * copies of pm_idle before proceeding.
2418 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2419 && (apm_info.connection_version > 0x0100)) {
2420 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2422 apm_error("disengage power management", error);
2424 misc_deregister(&apm_device);
2425 remove_proc_entry("apm", NULL);
2427 pm_power_off = NULL;
2429 kthread_stop(kapmd_task);
2434 module_init(apm_init);
2435 module_exit(apm_exit);
2437 MODULE_AUTHOR("Stephen Rothwell");
2438 MODULE_DESCRIPTION("Advanced Power Management");
2439 MODULE_LICENSE("GPL");
2440 module_param(debug, bool, 0644);
2441 MODULE_PARM_DESC(debug, "Enable debug mode");
2442 module_param(power_off, bool, 0444);
2443 MODULE_PARM_DESC(power_off, "Enable power off");
2444 module_param(bounce_interval, int, 0444);
2445 MODULE_PARM_DESC(bounce_interval,
2446 "Set the number of ticks to ignore suspend bounces");
2447 module_param(allow_ints, bool, 0444);
2448 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2449 module_param(broken_psr, bool, 0444);
2450 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2451 module_param(realmode_power_off, bool, 0444);
2452 MODULE_PARM_DESC(realmode_power_off,
2453 "Switch to real mode before powering off");
2454 #ifdef CONFIG_APM_CPU_IDLE
2455 module_param(idle_threshold, int, 0444);
2456 MODULE_PARM_DESC(idle_threshold,
2457 "System idle percentage above which to make APM BIOS idle calls");
2458 module_param(idle_period, int, 0444);
2459 MODULE_PARM_DESC(idle_period,
2460 "Period (in sec/100) over which to caculate the idle percentage");
2462 module_param(smp, bool, 0444);
2463 MODULE_PARM_DESC(smp,
2464 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2465 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);