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 #define pr_fmt(fmt) "apm: " fmt
206 #include <linux/module.h>
208 #include <linux/poll.h>
209 #include <linux/types.h>
210 #include <linux/stddef.h>
211 #include <linux/timer.h>
212 #include <linux/fcntl.h>
213 #include <linux/slab.h>
214 #include <linux/stat.h>
215 #include <linux/proc_fs.h>
216 #include <linux/seq_file.h>
217 #include <linux/miscdevice.h>
218 #include <linux/apm_bios.h>
219 #include <linux/init.h>
220 #include <linux/time.h>
221 #include <linux/sched.h>
222 #include <linux/pm.h>
223 #include <linux/capability.h>
224 #include <linux/device.h>
225 #include <linux/kernel.h>
226 #include <linux/freezer.h>
227 #include <linux/smp.h>
228 #include <linux/dmi.h>
229 #include <linux/suspend.h>
230 #include <linux/kthread.h>
231 #include <linux/jiffies.h>
232 #include <linux/acpi.h>
233 #include <linux/syscore_ops.h>
234 #include <linux/i8253.h>
235 #include <linux/cpuidle.h>
237 #include <asm/uaccess.h>
238 #include <asm/desc.h>
239 #include <asm/olpc.h>
240 #include <asm/paravirt.h>
241 #include <asm/reboot.h>
242 #include <asm/nospec-branch.h>
244 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
245 extern int (*console_blank_hook)(int);
249 * The apm_bios device is one of the misc char devices.
250 * This is its minor number.
252 #define APM_MINOR_DEV 134
255 * Various options can be changed at boot time as follows:
256 * (We allow underscores for compatibility with the modules code)
257 * apm=on/off enable/disable APM
258 * [no-]allow[-_]ints allow interrupts during BIOS calls
259 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
260 * [no-]realmode[-_]power[-_]off switch to real mode before
262 * [no-]debug log some debugging messages
263 * [no-]power[-_]off power off on shutdown
264 * [no-]smp Use apm even on an SMP box
265 * bounce[-_]interval=<n> number of ticks to ignore suspend
267 * idle[-_]threshold=<n> System idle percentage above which to
268 * make APM BIOS idle calls. Set it to
270 * idle[-_]period=<n> Period (in 1/100s of a second) over
271 * which the idle percentage is
275 /* KNOWN PROBLEM MACHINES:
277 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
278 * [Confirmed by TI representative]
279 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
280 * [Confirmed by BIOS disassembly]
281 * [This may work now ...]
282 * P: Toshiba 1950S: battery life information only gets updated after resume
283 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
284 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
285 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
286 * Neale Banks <neale@lowendale.com.au> December 2000
288 * Legend: U = unusable with APM patches
289 * P = partially usable with APM patches
293 * Define as 1 to make the driver always call the APM BIOS busy
294 * routine even if the clock was not reported as slowed by the
295 * idle routine. Otherwise, define as 0.
297 #define ALWAYS_CALL_BUSY 1
300 * Define to make the APM BIOS calls zero all data segment registers (so
301 * that an incorrect BIOS implementation will cause a kernel panic if it
302 * tries to write to arbitrary memory).
304 #define APM_ZERO_SEGS
309 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
310 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
311 * David Chen <chen@ctpa04.mit.edu>
313 #undef INIT_TIMER_AFTER_SUSPEND
315 #ifdef INIT_TIMER_AFTER_SUSPEND
316 #include <linux/timex.h>
318 #include <linux/delay.h>
322 * Need to poll the APM BIOS every second
324 #define APM_CHECK_TIMEOUT (HZ)
327 * Ignore suspend events for this amount of time after a resume
329 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
332 * Maximum number of events stored
334 #define APM_MAX_EVENTS 20
337 * The per-file APM data
341 struct apm_user *next;
342 unsigned int suser: 1;
343 unsigned int writer: 1;
344 unsigned int reader: 1;
345 unsigned int suspend_wait: 1;
347 int suspends_pending;
348 int standbys_pending;
353 apm_event_t events[APM_MAX_EVENTS];
357 * The magic number in apm_user
359 #define APM_BIOS_MAGIC 0x4101
362 * idle percentage above which bios idle calls are done
364 #ifdef CONFIG_APM_CPU_IDLE
365 #define DEFAULT_IDLE_THRESHOLD 95
367 #define DEFAULT_IDLE_THRESHOLD 100
369 #define DEFAULT_IDLE_PERIOD (100 / 3)
371 static int apm_cpu_idle(struct cpuidle_device *dev,
372 struct cpuidle_driver *drv, int index);
374 static struct cpuidle_driver apm_idle_driver = {
376 .owner = THIS_MODULE,
378 { /* entry 0 is for polling */ },
379 { /* entry 1 is for APM idle */
382 .exit_latency = 250, /* WAG */
383 .target_residency = 500, /* WAG */
384 .enter = &apm_cpu_idle
390 static struct cpuidle_device apm_cpuidle_device;
396 unsigned long offset;
397 unsigned short segment;
399 static int clock_slowed;
400 static int idle_threshold __read_mostly = DEFAULT_IDLE_THRESHOLD;
401 static int idle_period __read_mostly = DEFAULT_IDLE_PERIOD;
402 static int suspends_pending;
403 static int standbys_pending;
404 static int ignore_sys_suspend;
405 static int ignore_normal_resume;
406 static int bounce_interval __read_mostly = DEFAULT_BOUNCE_INTERVAL;
408 static bool debug __read_mostly;
409 static bool smp __read_mostly;
410 static int apm_disabled = -1;
412 static bool power_off;
414 static bool power_off = 1;
416 static bool realmode_power_off;
417 #ifdef CONFIG_APM_ALLOW_INTS
418 static bool allow_ints = 1;
420 static bool allow_ints;
422 static bool broken_psr;
424 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue);
425 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue);
426 static struct apm_user *user_list;
427 static DEFINE_SPINLOCK(user_list_lock);
428 static DEFINE_MUTEX(apm_mutex);
431 * Set up a segment that references the real mode segment 0x40
432 * that extends up to the end of page zero (that we have reserved).
433 * This is for buggy BIOS's that refer to (real mode) segment 0x40
434 * even though they are called in protected mode.
436 static struct desc_struct bad_bios_desc = GDT_ENTRY_INIT(0x4092,
437 (unsigned long)__va(0x400UL), PAGE_SIZE - 0x400 - 1);
439 static const char driver_version[] = "1.16ac"; /* no spaces */
441 static struct task_struct *kapmd_task;
444 * APM event names taken from the APM 1.2 specification. These are
445 * the message codes that the BIOS uses to tell us about events
447 static const char * const apm_event_name[] = {
453 "power status change",
458 "system standby resume",
459 "capabilities change"
461 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
463 typedef struct lookup_t {
469 * The BIOS returns a set of standard error codes in AX when the
473 static const lookup_t error_table[] = {
474 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
475 { APM_DISABLED, "Power management disabled" },
476 { APM_CONNECTED, "Real mode interface already connected" },
477 { APM_NOT_CONNECTED, "Interface not connected" },
478 { APM_16_CONNECTED, "16 bit interface already connected" },
479 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
480 { APM_32_CONNECTED, "32 bit interface already connected" },
481 { APM_32_UNSUPPORTED, "32 bit interface not supported" },
482 { APM_BAD_DEVICE, "Unrecognized device ID" },
483 { APM_BAD_PARAM, "Parameter out of range" },
484 { APM_NOT_ENGAGED, "Interface not engaged" },
485 { APM_BAD_FUNCTION, "Function not supported" },
486 { APM_RESUME_DISABLED, "Resume timer disabled" },
487 { APM_BAD_STATE, "Unable to enter requested state" },
488 /* N/A { APM_NO_EVENTS, "No events pending" }, */
489 { APM_NO_ERROR, "BIOS did not set a return code" },
490 { APM_NOT_PRESENT, "No APM present" }
492 #define ERROR_COUNT ARRAY_SIZE(error_table)
495 * apm_error - display an APM error
496 * @str: information string
497 * @err: APM BIOS return code
499 * Write a meaningful log entry to the kernel log in the event of
500 * an APM error. Note that this also handles (negative) kernel errors.
503 static void apm_error(char *str, int err)
507 for (i = 0; i < ERROR_COUNT; i++)
508 if (error_table[i].key == err)
511 pr_notice("%s: %s\n", str, error_table[i].msg);
513 pr_notice("%s: linux error code %i\n", str, err);
515 pr_notice("%s: unknown error code %#2.2x\n",
520 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
521 * apm_info.allow_ints, we are being really paranoid here! Not only
522 * are interrupts disabled, but all the segment registers (except SS)
523 * are saved and zeroed this means that if the BIOS tries to reference
524 * any data without explicitly loading the segment registers, the kernel
525 * will fault immediately rather than have some unforeseen circumstances
526 * for the rest of the kernel. And it will be very obvious! :-) Doing
527 * this depends on CS referring to the same physical memory as DS so that
528 * DS can be zeroed before the call. Unfortunately, we can't do anything
529 * about the stack segment/pointer. Also, we tell the compiler that
530 * everything could change.
532 * Also, we KNOW that for the non error case of apm_bios_call, there
533 * is no useful data returned in the low order 8 bits of eax.
536 static inline unsigned long __apm_irq_save(void)
539 local_save_flags(flags);
540 if (apm_info.allow_ints) {
541 if (irqs_disabled_flags(flags))
549 #define apm_irq_save(flags) \
550 do { flags = __apm_irq_save(); } while (0)
552 static inline void apm_irq_restore(unsigned long flags)
554 if (irqs_disabled_flags(flags))
556 else if (irqs_disabled())
561 # define APM_DECL_SEGS \
562 unsigned int saved_fs; unsigned int saved_gs;
563 # define APM_DO_SAVE_SEGS \
564 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
565 # define APM_DO_RESTORE_SEGS \
566 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
568 # define APM_DECL_SEGS
569 # define APM_DO_SAVE_SEGS
570 # define APM_DO_RESTORE_SEGS
573 struct apm_bios_call {
583 /* Error: -ENOMEM, or bits 8-15 of eax */
588 * __apm_bios_call - Make an APM BIOS 32bit call
589 * @_call: pointer to struct apm_bios_call.
591 * Make an APM call using the 32bit protected mode interface. The
592 * caller is responsible for knowing if APM BIOS is configured and
593 * enabled. This call can disable interrupts for a long period of
594 * time on some laptops. The return value is in AH and the carry
595 * flag is loaded into AL. If there is an error, then the error
596 * code is returned in AH (bits 8-15 of eax) and this function
599 * Note: this makes the call on the current CPU.
601 static long __apm_bios_call(void *_call)
606 struct desc_struct save_desc_40;
607 struct desc_struct *gdt;
608 struct apm_bios_call *call = _call;
612 gdt = get_cpu_gdt_table(cpu);
613 save_desc_40 = gdt[0x40 / 8];
614 gdt[0x40 / 8] = bad_bios_desc;
617 firmware_restrict_branch_speculation_start();
619 apm_bios_call_asm(call->func, call->ebx, call->ecx,
620 &call->eax, &call->ebx, &call->ecx, &call->edx,
623 firmware_restrict_branch_speculation_end();
624 apm_irq_restore(flags);
625 gdt[0x40 / 8] = save_desc_40;
628 return call->eax & 0xff;
631 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
632 static int on_cpu0(long (*fn)(void *), struct apm_bios_call *call)
636 /* Don't bother with work_on_cpu in the common case, so we don't
637 * have to worry about OOM or overhead. */
638 if (get_cpu() == 0) {
643 ret = work_on_cpu(0, fn, call);
646 /* work_on_cpu can fail with -ENOMEM */
650 call->err = (call->eax >> 8) & 0xff;
656 * apm_bios_call - Make an APM BIOS 32bit call (on CPU 0)
657 * @call: the apm_bios_call registers.
659 * If there is an error, it is returned in @call.err.
661 static int apm_bios_call(struct apm_bios_call *call)
663 return on_cpu0(__apm_bios_call, call);
667 * __apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
668 * @_call: pointer to struct apm_bios_call.
670 * Make a BIOS call that returns one value only, or just status.
671 * If there is an error, then the error code is returned in AH
672 * (bits 8-15 of eax) and this function returns non-zero (it can
673 * also return -ENOMEM). This is used for simpler BIOS operations.
674 * This call may hold interrupts off for a long time on some laptops.
676 * Note: this makes the call on the current CPU.
678 static long __apm_bios_call_simple(void *_call)
684 struct desc_struct save_desc_40;
685 struct desc_struct *gdt;
686 struct apm_bios_call *call = _call;
690 gdt = get_cpu_gdt_table(cpu);
691 save_desc_40 = gdt[0x40 / 8];
692 gdt[0x40 / 8] = bad_bios_desc;
695 firmware_restrict_branch_speculation_start();
697 error = apm_bios_call_simple_asm(call->func, call->ebx, call->ecx,
700 firmware_restrict_branch_speculation_end();
701 apm_irq_restore(flags);
702 gdt[0x40 / 8] = save_desc_40;
708 * apm_bios_call_simple - make a simple APM BIOS 32bit call
709 * @func: APM function to invoke
710 * @ebx_in: EBX register value for BIOS call
711 * @ecx_in: ECX register value for BIOS call
712 * @eax: EAX register on return from the BIOS call
715 * Make a BIOS call that returns one value only, or just status.
716 * If there is an error, then the error code is returned in @err
717 * and this function returns non-zero. This is used for simpler
718 * BIOS operations. This call may hold interrupts off for a long
719 * time on some laptops.
721 static int apm_bios_call_simple(u32 func, u32 ebx_in, u32 ecx_in, u32 *eax,
724 struct apm_bios_call call;
731 ret = on_cpu0(__apm_bios_call_simple, &call);
738 * apm_driver_version - APM driver version
739 * @val: loaded with the APM version on return
741 * Retrieve the APM version supported by the BIOS. This is only
742 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
745 * On entry val should point to a value indicating the APM driver
746 * version with the high byte being the major and the low byte the
747 * minor number both in BCD
749 * On return it will hold the BIOS revision supported in the
753 static int apm_driver_version(u_short *val)
758 if (apm_bios_call_simple(APM_FUNC_VERSION, 0, *val, &eax, &err))
765 * apm_get_event - get an APM event from the BIOS
766 * @event: pointer to the event
767 * @info: point to the event information
769 * The APM BIOS provides a polled information for event
770 * reporting. The BIOS expects to be polled at least every second
771 * when events are pending. When a message is found the caller should
772 * poll until no more messages are present. However, this causes
773 * problems on some laptops where a suspend event notification is
774 * not cleared until it is acknowledged.
776 * Additional information is returned in the info pointer, providing
777 * that APM 1.2 is in use. If no messges are pending the value 0x80
778 * is returned (No power management events pending).
780 static int apm_get_event(apm_event_t *event, apm_eventinfo_t *info)
782 struct apm_bios_call call;
784 call.func = APM_FUNC_GET_EVENT;
785 call.ebx = call.ecx = 0;
787 if (apm_bios_call(&call))
791 if (apm_info.connection_version < 0x0102)
792 *info = ~0; /* indicate info not valid */
799 * set_power_state - set the power management state
800 * @what: which items to transition
801 * @state: state to transition to
803 * Request an APM change of state for one or more system devices. The
804 * processor state must be transitioned last of all. what holds the
805 * class of device in the upper byte and the device number (0xFF for
806 * all) for the object to be transitioned.
808 * The state holds the state to transition to, which may in fact
809 * be an acceptance of a BIOS requested state change.
812 static int set_power_state(u_short what, u_short state)
817 if (apm_bios_call_simple(APM_FUNC_SET_STATE, what, state, &eax, &err))
823 * set_system_power_state - set system wide power state
824 * @state: which state to enter
826 * Transition the entire system into a new APM power state.
829 static int set_system_power_state(u_short state)
831 return set_power_state(APM_DEVICE_ALL, state);
835 * apm_do_idle - perform power saving
837 * This function notifies the BIOS that the processor is (in the view
838 * of the OS) idle. It returns -1 in the event that the BIOS refuses
839 * to handle the idle request. On a success the function returns 1
840 * if the BIOS did clock slowing or 0 otherwise.
843 static int apm_do_idle(void)
850 if (!need_resched()) {
852 ret = apm_bios_call_simple(APM_FUNC_IDLE, 0, 0, &eax, &err);
859 static unsigned long t;
861 /* This always fails on some SMP boards running UP kernels.
862 * Only report the failure the first 5 times.
865 printk(KERN_DEBUG "apm_do_idle failed (%d)\n", err);
870 clock_slowed = (apm_info.bios.flags & APM_IDLE_SLOWS_CLOCK) != 0;
875 * apm_do_busy - inform the BIOS the CPU is busy
877 * Request that the BIOS brings the CPU back to full performance.
880 static void apm_do_busy(void)
885 if (clock_slowed || ALWAYS_CALL_BUSY) {
886 (void)apm_bios_call_simple(APM_FUNC_BUSY, 0, 0, &dummy, &err);
892 * If no process has really been interested in
893 * the CPU for some time, we want to call BIOS
894 * power management - we probably want
897 #define IDLE_CALC_LIMIT (HZ * 100)
898 #define IDLE_LEAKY_MAX 16
901 * apm_cpu_idle - cpu idling for APM capable Linux
903 * This is the idling function the kernel executes when APM is available. It
904 * tries to do BIOS powermanagement based on the average system idle time.
905 * Furthermore it calls the system default idle routine.
908 static int apm_cpu_idle(struct cpuidle_device *dev,
909 struct cpuidle_driver *drv, int index)
911 static int use_apm_idle; /* = 0 */
912 static unsigned int last_jiffies; /* = 0 */
913 static unsigned int last_stime; /* = 0 */
916 int apm_idle_done = 0;
917 unsigned int jiffies_since_last_check = jiffies - last_jiffies;
921 task_cputime(current, NULL, &stime);
922 if (jiffies_since_last_check > IDLE_CALC_LIMIT) {
924 } else if (jiffies_since_last_check > idle_period) {
925 unsigned int idle_percentage;
927 idle_percentage = cputime_to_jiffies(stime - last_stime);
928 idle_percentage *= 100;
929 idle_percentage /= jiffies_since_last_check;
930 use_apm_idle = (idle_percentage > idle_threshold);
931 if (apm_info.forbid_idle)
935 last_jiffies = jiffies;
938 bucket = IDLE_LEAKY_MAX;
940 while (!need_resched()) {
945 switch (apm_do_idle()) {
950 bucket = IDLE_LEAKY_MAX;
961 default: /* BIOS refused */
967 jiffies_since_last_check = jiffies - last_jiffies;
968 if (jiffies_since_last_check > idle_period)
979 * apm_power_off - ask the BIOS to power off
981 * Handle the power off sequence. This is the one piece of code we
982 * will execute even on SMP machines. In order to deal with BIOS
983 * bugs we support real mode APM BIOS power off calls. We also make
984 * the SMP call on CPU0 as some systems will only honour this call
985 * on their first cpu.
988 static void apm_power_off(void)
990 /* Some bioses don't like being called from CPU != 0 */
991 if (apm_info.realmode_power_off) {
992 set_cpus_allowed_ptr(current, cpumask_of(0));
993 machine_real_restart(MRR_APM);
995 (void)set_system_power_state(APM_STATE_OFF);
999 #ifdef CONFIG_APM_DO_ENABLE
1002 * apm_enable_power_management - enable BIOS APM power management
1003 * @enable: enable yes/no
1005 * Enable or disable the APM BIOS power services.
1008 static int apm_enable_power_management(int enable)
1013 if ((enable == 0) && (apm_info.bios.flags & APM_BIOS_DISENGAGED))
1014 return APM_NOT_ENGAGED;
1015 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM, APM_DEVICE_BALL,
1016 enable, &eax, &err))
1019 apm_info.bios.flags &= ~APM_BIOS_DISABLED;
1021 apm_info.bios.flags |= APM_BIOS_DISABLED;
1027 * apm_get_power_status - get current power state
1028 * @status: returned status
1029 * @bat: battery info
1030 * @life: estimated life
1032 * Obtain the current power status from the APM BIOS. We return a
1033 * status which gives the rough battery status, and current power
1034 * source. The bat value returned give an estimate as a percentage
1035 * of life and a status value for the battery. The estimated life
1036 * if reported is a lifetime in secodnds/minutes at current powwer
1040 static int apm_get_power_status(u_short *status, u_short *bat, u_short *life)
1042 struct apm_bios_call call;
1044 call.func = APM_FUNC_GET_STATUS;
1045 call.ebx = APM_DEVICE_ALL;
1048 if (apm_info.get_power_status_broken)
1049 return APM_32_UNSUPPORTED;
1050 if (apm_bios_call(&call)) {
1052 return APM_NO_ERROR;
1057 if (apm_info.get_power_status_swabinminutes) {
1058 *life = swab16((u16)call.edx);
1066 static int apm_get_battery_status(u_short which, u_short *status,
1067 u_short *bat, u_short *life, u_short *nbat)
1075 if (apm_info.connection_version < 0x0102) {
1076 /* pretend we only have one battery. */
1078 return APM_BAD_DEVICE;
1080 return apm_get_power_status(status, bat, life);
1083 if (apm_bios_call(APM_FUNC_GET_STATUS, (0x8000 | (which)), 0, &eax,
1084 &ebx, &ecx, &edx, &esi))
1085 return (eax >> 8) & 0xff;
1095 * apm_engage_power_management - enable PM on a device
1096 * @device: identity of device
1099 * Activate or deactivate power management on either a specific device
1100 * or the entire system (%APM_DEVICE_ALL).
1103 static int apm_engage_power_management(u_short device, int enable)
1108 if ((enable == 0) && (device == APM_DEVICE_ALL)
1109 && (apm_info.bios.flags & APM_BIOS_DISABLED))
1110 return APM_DISABLED;
1111 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM, device, enable,
1114 if (device == APM_DEVICE_ALL) {
1116 apm_info.bios.flags &= ~APM_BIOS_DISENGAGED;
1118 apm_info.bios.flags |= APM_BIOS_DISENGAGED;
1123 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1126 * apm_console_blank - blank the display
1129 * Attempt to blank the console, firstly by blanking just video device
1130 * zero, and if that fails (some BIOSes don't support it) then it blanks
1131 * all video devices. Typically the BIOS will do laptop backlight and
1132 * monitor powerdown for us.
1135 static int apm_console_blank(int blank)
1137 int error = APM_NOT_ENGAGED; /* silence gcc */
1140 static const u_short dev[3] = { 0x100, 0x1FF, 0x101 };
1142 state = blank ? APM_STATE_STANDBY : APM_STATE_READY;
1144 for (i = 0; i < ARRAY_SIZE(dev); i++) {
1145 error = set_power_state(dev[i], state);
1147 if ((error == APM_SUCCESS) || (error == APM_NO_ERROR))
1150 if (error == APM_NOT_ENGAGED)
1154 if (error == APM_NOT_ENGAGED) {
1158 eng_error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1160 apm_error("set display", error);
1161 apm_error("engage interface", eng_error);
1164 return apm_console_blank(blank);
1167 apm_error("set display", error);
1172 static int queue_empty(struct apm_user *as)
1174 return as->event_head == as->event_tail;
1177 static apm_event_t get_queued_event(struct apm_user *as)
1179 if (++as->event_tail >= APM_MAX_EVENTS)
1181 return as->events[as->event_tail];
1184 static void queue_event(apm_event_t event, struct apm_user *sender)
1186 struct apm_user *as;
1188 spin_lock(&user_list_lock);
1189 if (user_list == NULL)
1191 for (as = user_list; as != NULL; as = as->next) {
1192 if ((as == sender) || (!as->reader))
1194 if (++as->event_head >= APM_MAX_EVENTS)
1197 if (as->event_head == as->event_tail) {
1198 static int notified;
1200 if (notified++ == 0)
1201 pr_err("an event queue overflowed\n");
1202 if (++as->event_tail >= APM_MAX_EVENTS)
1205 as->events[as->event_head] = event;
1206 if (!as->suser || !as->writer)
1209 case APM_SYS_SUSPEND:
1210 case APM_USER_SUSPEND:
1211 as->suspends_pending++;
1215 case APM_SYS_STANDBY:
1216 case APM_USER_STANDBY:
1217 as->standbys_pending++;
1222 wake_up_interruptible(&apm_waitqueue);
1224 spin_unlock(&user_list_lock);
1227 static void reinit_timer(void)
1229 #ifdef INIT_TIMER_AFTER_SUSPEND
1230 unsigned long flags;
1232 raw_spin_lock_irqsave(&i8253_lock, flags);
1233 /* set the clock to HZ */
1234 outb_p(0x34, PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
1236 outb_p(LATCH & 0xff, PIT_CH0); /* LSB */
1238 outb_p(LATCH >> 8, PIT_CH0); /* MSB */
1240 raw_spin_unlock_irqrestore(&i8253_lock, flags);
1244 static int suspend(int vetoable)
1247 struct apm_user *as;
1249 dpm_suspend_start(PMSG_SUSPEND);
1250 dpm_suspend_end(PMSG_SUSPEND);
1252 local_irq_disable();
1257 save_processor_state();
1258 err = set_system_power_state(APM_STATE_SUSPEND);
1259 ignore_normal_resume = 1;
1260 restore_processor_state();
1262 local_irq_disable();
1265 if (err == APM_NO_ERROR)
1267 if (err != APM_SUCCESS)
1268 apm_error("suspend", err);
1269 err = (err == APM_SUCCESS) ? 0 : -EIO;
1274 dpm_resume_start(PMSG_RESUME);
1275 dpm_resume_end(PMSG_RESUME);
1277 queue_event(APM_NORMAL_RESUME, NULL);
1278 spin_lock(&user_list_lock);
1279 for (as = user_list; as != NULL; as = as->next) {
1280 as->suspend_wait = 0;
1281 as->suspend_result = err;
1283 spin_unlock(&user_list_lock);
1284 wake_up_interruptible(&apm_suspend_waitqueue);
1288 static void standby(void)
1292 dpm_suspend_end(PMSG_SUSPEND);
1294 local_irq_disable();
1298 err = set_system_power_state(APM_STATE_STANDBY);
1299 if ((err != APM_SUCCESS) && (err != APM_NO_ERROR))
1300 apm_error("standby", err);
1302 local_irq_disable();
1306 dpm_resume_start(PMSG_RESUME);
1309 static apm_event_t get_event(void)
1312 apm_event_t event = APM_NO_EVENTS; /* silence gcc */
1313 apm_eventinfo_t info;
1315 static int notified;
1317 /* we don't use the eventinfo */
1318 error = apm_get_event(&event, &info);
1319 if (error == APM_SUCCESS)
1322 if ((error != APM_NO_EVENTS) && (notified++ == 0))
1323 apm_error("get_event", error);
1328 static void check_events(void)
1331 static unsigned long last_resume;
1332 static int ignore_bounce;
1334 while ((event = get_event()) != 0) {
1336 if (event <= NR_APM_EVENT_NAME)
1337 printk(KERN_DEBUG "apm: received %s notify\n",
1338 apm_event_name[event - 1]);
1340 printk(KERN_DEBUG "apm: received unknown "
1341 "event 0x%02x\n", event);
1344 && (time_after(jiffies, last_resume + bounce_interval)))
1348 case APM_SYS_STANDBY:
1349 case APM_USER_STANDBY:
1350 queue_event(event, NULL);
1351 if (standbys_pending <= 0)
1355 case APM_USER_SUSPEND:
1356 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1357 if (apm_info.connection_version > 0x100)
1358 set_system_power_state(APM_STATE_REJECT);
1361 case APM_SYS_SUSPEND:
1362 if (ignore_bounce) {
1363 if (apm_info.connection_version > 0x100)
1364 set_system_power_state(APM_STATE_REJECT);
1368 * If we are already processing a SUSPEND,
1369 * then further SUSPEND events from the BIOS
1370 * will be ignored. We also return here to
1371 * cope with the fact that the Thinkpads keep
1372 * sending a SUSPEND event until something else
1375 if (ignore_sys_suspend)
1377 ignore_sys_suspend = 1;
1378 queue_event(event, NULL);
1379 if (suspends_pending <= 0)
1383 case APM_NORMAL_RESUME:
1384 case APM_CRITICAL_RESUME:
1385 case APM_STANDBY_RESUME:
1386 ignore_sys_suspend = 0;
1387 last_resume = jiffies;
1389 if ((event != APM_NORMAL_RESUME)
1390 || (ignore_normal_resume == 0)) {
1391 dpm_resume_end(PMSG_RESUME);
1392 queue_event(event, NULL);
1394 ignore_normal_resume = 0;
1397 case APM_CAPABILITY_CHANGE:
1398 case APM_LOW_BATTERY:
1399 case APM_POWER_STATUS_CHANGE:
1400 queue_event(event, NULL);
1401 /* If needed, notify drivers here */
1404 case APM_UPDATE_TIME:
1407 case APM_CRITICAL_SUSPEND:
1409 * We are not allowed to reject a critical suspend.
1417 static void apm_event_handler(void)
1419 static int pending_count = 4;
1422 if ((standbys_pending > 0) || (suspends_pending > 0)) {
1423 if ((apm_info.connection_version > 0x100) &&
1424 (pending_count-- <= 0)) {
1427 printk(KERN_DEBUG "apm: setting state busy\n");
1428 err = set_system_power_state(APM_STATE_BUSY);
1430 apm_error("busy", err);
1438 * This is the APM thread main loop.
1441 static void apm_mainloop(void)
1443 DECLARE_WAITQUEUE(wait, current);
1445 add_wait_queue(&apm_waitqueue, &wait);
1446 set_current_state(TASK_INTERRUPTIBLE);
1448 schedule_timeout(APM_CHECK_TIMEOUT);
1449 if (kthread_should_stop())
1452 * Ok, check all events, check for idle (and mark us sleeping
1453 * so as not to count towards the load average)..
1455 set_current_state(TASK_INTERRUPTIBLE);
1456 apm_event_handler();
1458 remove_wait_queue(&apm_waitqueue, &wait);
1461 static int check_apm_user(struct apm_user *as, const char *func)
1463 if (as == NULL || as->magic != APM_BIOS_MAGIC) {
1464 pr_err("%s passed bad filp\n", func);
1470 static ssize_t do_read(struct file *fp, char __user *buf, size_t count, loff_t *ppos)
1472 struct apm_user *as;
1476 as = fp->private_data;
1477 if (check_apm_user(as, "read"))
1479 if ((int)count < sizeof(apm_event_t))
1481 if ((queue_empty(as)) && (fp->f_flags & O_NONBLOCK))
1483 wait_event_interruptible(apm_waitqueue, !queue_empty(as));
1485 while ((i >= sizeof(event)) && !queue_empty(as)) {
1486 event = get_queued_event(as);
1487 if (copy_to_user(buf, &event, sizeof(event))) {
1493 case APM_SYS_SUSPEND:
1494 case APM_USER_SUSPEND:
1495 as->suspends_read++;
1498 case APM_SYS_STANDBY:
1499 case APM_USER_STANDBY:
1500 as->standbys_read++;
1503 buf += sizeof(event);
1508 if (signal_pending(current))
1509 return -ERESTARTSYS;
1513 static unsigned int do_poll(struct file *fp, poll_table *wait)
1515 struct apm_user *as;
1517 as = fp->private_data;
1518 if (check_apm_user(as, "poll"))
1520 poll_wait(fp, &apm_waitqueue, wait);
1521 if (!queue_empty(as))
1522 return POLLIN | POLLRDNORM;
1526 static long do_ioctl(struct file *filp, u_int cmd, u_long arg)
1528 struct apm_user *as;
1531 as = filp->private_data;
1532 if (check_apm_user(as, "ioctl"))
1534 if (!as->suser || !as->writer)
1537 case APM_IOC_STANDBY:
1538 mutex_lock(&apm_mutex);
1539 if (as->standbys_read > 0) {
1540 as->standbys_read--;
1541 as->standbys_pending--;
1544 queue_event(APM_USER_STANDBY, as);
1545 if (standbys_pending <= 0)
1547 mutex_unlock(&apm_mutex);
1549 case APM_IOC_SUSPEND:
1550 mutex_lock(&apm_mutex);
1551 if (as->suspends_read > 0) {
1552 as->suspends_read--;
1553 as->suspends_pending--;
1556 queue_event(APM_USER_SUSPEND, as);
1557 if (suspends_pending <= 0) {
1559 mutex_unlock(&apm_mutex);
1561 as->suspend_wait = 1;
1562 mutex_unlock(&apm_mutex);
1563 wait_event_interruptible(apm_suspend_waitqueue,
1564 as->suspend_wait == 0);
1565 ret = as->suspend_result;
1574 static int do_release(struct inode *inode, struct file *filp)
1576 struct apm_user *as;
1578 as = filp->private_data;
1579 if (check_apm_user(as, "release"))
1581 filp->private_data = NULL;
1582 if (as->standbys_pending > 0) {
1583 standbys_pending -= as->standbys_pending;
1584 if (standbys_pending <= 0)
1587 if (as->suspends_pending > 0) {
1588 suspends_pending -= as->suspends_pending;
1589 if (suspends_pending <= 0)
1592 spin_lock(&user_list_lock);
1593 if (user_list == as)
1594 user_list = as->next;
1596 struct apm_user *as1;
1598 for (as1 = user_list;
1599 (as1 != NULL) && (as1->next != as);
1603 pr_err("filp not in user list\n");
1605 as1->next = as->next;
1607 spin_unlock(&user_list_lock);
1612 static int do_open(struct inode *inode, struct file *filp)
1614 struct apm_user *as;
1616 as = kmalloc(sizeof(*as), GFP_KERNEL);
1620 as->magic = APM_BIOS_MAGIC;
1621 as->event_tail = as->event_head = 0;
1622 as->suspends_pending = as->standbys_pending = 0;
1623 as->suspends_read = as->standbys_read = 0;
1625 * XXX - this is a tiny bit broken, when we consider BSD
1626 * process accounting. If the device is opened by root, we
1627 * instantly flag that we used superuser privs. Who knows,
1628 * we might close the device immediately without doing a
1629 * privileged operation -- cevans
1631 as->suser = capable(CAP_SYS_ADMIN);
1632 as->writer = (filp->f_mode & FMODE_WRITE) == FMODE_WRITE;
1633 as->reader = (filp->f_mode & FMODE_READ) == FMODE_READ;
1634 spin_lock(&user_list_lock);
1635 as->next = user_list;
1637 spin_unlock(&user_list_lock);
1638 filp->private_data = as;
1642 static int proc_apm_show(struct seq_file *m, void *v)
1648 unsigned short ac_line_status = 0xff;
1649 unsigned short battery_status = 0xff;
1650 unsigned short battery_flag = 0xff;
1651 int percentage = -1;
1652 int time_units = -1;
1655 if ((num_online_cpus() == 1) &&
1656 !(error = apm_get_power_status(&bx, &cx, &dx))) {
1657 ac_line_status = (bx >> 8) & 0xff;
1658 battery_status = bx & 0xff;
1659 if ((cx & 0xff) != 0xff)
1660 percentage = cx & 0xff;
1662 if (apm_info.connection_version > 0x100) {
1663 battery_flag = (cx >> 8) & 0xff;
1665 units = (dx & 0x8000) ? "min" : "sec";
1666 time_units = dx & 0x7fff;
1670 /* Arguments, with symbols from linux/apm_bios.h. Information is
1671 from the Get Power Status (0x0a) call unless otherwise noted.
1673 0) Linux driver version (this will change if format changes)
1674 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1675 2) APM flags from APM Installation Check (0x00):
1676 bit 0: APM_16_BIT_SUPPORT
1677 bit 1: APM_32_BIT_SUPPORT
1678 bit 2: APM_IDLE_SLOWS_CLOCK
1679 bit 3: APM_BIOS_DISABLED
1680 bit 4: APM_BIOS_DISENGAGED
1684 0x02: On backup power (BIOS >= 1.1 only)
1691 0x04: Selected battery not present (BIOS >= 1.2 only)
1698 bit 7: No system battery
1700 6) Remaining battery life (percentage of charge):
1703 7) Remaining battery life (time units):
1704 Number of remaining minutes or seconds
1706 8) min = minutes; sec = seconds */
1708 seq_printf(m, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1710 (apm_info.bios.version >> 8) & 0xff,
1711 apm_info.bios.version & 0xff,
1712 apm_info.bios.flags,
1722 static int proc_apm_open(struct inode *inode, struct file *file)
1724 return single_open(file, proc_apm_show, NULL);
1727 static const struct file_operations apm_file_ops = {
1728 .owner = THIS_MODULE,
1729 .open = proc_apm_open,
1731 .llseek = seq_lseek,
1732 .release = single_release,
1735 static int apm(void *unused)
1745 * This is to avoid random crashes at boot time during initialization
1746 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1747 * Some bioses don't like being called from CPU != 0.
1748 * Method suggested by Ingo Molnar.
1750 set_cpus_allowed_ptr(current, cpumask_of(0));
1751 BUG_ON(smp_processor_id() != 0);
1753 if (apm_info.connection_version == 0) {
1754 apm_info.connection_version = apm_info.bios.version;
1755 if (apm_info.connection_version > 0x100) {
1757 * We only support BIOSs up to version 1.2
1759 if (apm_info.connection_version > 0x0102)
1760 apm_info.connection_version = 0x0102;
1761 error = apm_driver_version(&apm_info.connection_version);
1762 if (error != APM_SUCCESS) {
1763 apm_error("driver version", error);
1764 /* Fall back to an APM 1.0 connection. */
1765 apm_info.connection_version = 0x100;
1771 printk(KERN_INFO "apm: Connection version %d.%d\n",
1772 (apm_info.connection_version >> 8) & 0xff,
1773 apm_info.connection_version & 0xff);
1775 #ifdef CONFIG_APM_DO_ENABLE
1776 if (apm_info.bios.flags & APM_BIOS_DISABLED) {
1778 * This call causes my NEC UltraLite Versa 33/C to hang if it
1779 * is booted with PM disabled but not in the docking station.
1782 error = apm_enable_power_management(1);
1784 apm_error("enable power management", error);
1790 if ((apm_info.bios.flags & APM_BIOS_DISENGAGED)
1791 && (apm_info.connection_version > 0x0100)) {
1792 error = apm_engage_power_management(APM_DEVICE_ALL, 1);
1794 apm_error("engage power management", error);
1799 if (debug && (num_online_cpus() == 1 || smp)) {
1800 error = apm_get_power_status(&bx, &cx, &dx);
1802 printk(KERN_INFO "apm: power status not available\n");
1804 switch ((bx >> 8) & 0xff) {
1806 power_stat = "off line";
1809 power_stat = "on line";
1812 power_stat = "on backup power";
1815 power_stat = "unknown";
1818 switch (bx & 0xff) {
1826 bat_stat = "critical";
1829 bat_stat = "charging";
1832 bat_stat = "unknown";
1836 "apm: AC %s, battery status %s, battery life ",
1837 power_stat, bat_stat);
1838 if ((cx & 0xff) == 0xff)
1839 printk("unknown\n");
1841 printk("%d%%\n", cx & 0xff);
1842 if (apm_info.connection_version > 0x100) {
1844 "apm: battery flag 0x%02x, battery life ",
1847 printk("unknown\n");
1849 printk("%d %s\n", dx & 0x7fff,
1851 "minutes" : "seconds");
1856 /* Install our power off handler.. */
1858 pm_power_off = apm_power_off;
1860 if (num_online_cpus() == 1 || smp) {
1861 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1862 console_blank_hook = apm_console_blank;
1865 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1866 console_blank_hook = NULL;
1874 static int __init apm_setup(char *str)
1878 while ((str != NULL) && (*str != '\0')) {
1879 if (strncmp(str, "off", 3) == 0)
1881 if (strncmp(str, "on", 2) == 0)
1883 if ((strncmp(str, "bounce-interval=", 16) == 0) ||
1884 (strncmp(str, "bounce_interval=", 16) == 0))
1885 bounce_interval = simple_strtol(str + 16, NULL, 0);
1886 if ((strncmp(str, "idle-threshold=", 15) == 0) ||
1887 (strncmp(str, "idle_threshold=", 15) == 0))
1888 idle_threshold = simple_strtol(str + 15, NULL, 0);
1889 if ((strncmp(str, "idle-period=", 12) == 0) ||
1890 (strncmp(str, "idle_period=", 12) == 0))
1891 idle_period = simple_strtol(str + 12, NULL, 0);
1892 invert = (strncmp(str, "no-", 3) == 0) ||
1893 (strncmp(str, "no_", 3) == 0);
1896 if (strncmp(str, "debug", 5) == 0)
1898 if ((strncmp(str, "power-off", 9) == 0) ||
1899 (strncmp(str, "power_off", 9) == 0))
1900 power_off = !invert;
1901 if (strncmp(str, "smp", 3) == 0) {
1903 idle_threshold = 100;
1905 if ((strncmp(str, "allow-ints", 10) == 0) ||
1906 (strncmp(str, "allow_ints", 10) == 0))
1907 apm_info.allow_ints = !invert;
1908 if ((strncmp(str, "broken-psr", 10) == 0) ||
1909 (strncmp(str, "broken_psr", 10) == 0))
1910 apm_info.get_power_status_broken = !invert;
1911 if ((strncmp(str, "realmode-power-off", 18) == 0) ||
1912 (strncmp(str, "realmode_power_off", 18) == 0))
1913 apm_info.realmode_power_off = !invert;
1914 str = strchr(str, ',');
1916 str += strspn(str, ", \t");
1921 __setup("apm=", apm_setup);
1924 static const struct file_operations apm_bios_fops = {
1925 .owner = THIS_MODULE,
1928 .unlocked_ioctl = do_ioctl,
1930 .release = do_release,
1931 .llseek = noop_llseek,
1934 static struct miscdevice apm_device = {
1941 /* Simple "print if true" callback */
1942 static int __init print_if_true(const struct dmi_system_id *d)
1944 printk("%s\n", d->ident);
1949 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1950 * disabled before the suspend. Linux used to get terribly confused by that.
1952 static int __init broken_ps2_resume(const struct dmi_system_id *d)
1954 printk(KERN_INFO "%s machine detected. Mousepad Resume Bug "
1955 "workaround hopefully not needed.\n", d->ident);
1959 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1960 static int __init set_realmode_power_off(const struct dmi_system_id *d)
1962 if (apm_info.realmode_power_off == 0) {
1963 apm_info.realmode_power_off = 1;
1964 printk(KERN_INFO "%s bios detected. "
1965 "Using realmode poweroff only.\n", d->ident);
1970 /* Some laptops require interrupts to be enabled during APM calls */
1971 static int __init set_apm_ints(const struct dmi_system_id *d)
1973 if (apm_info.allow_ints == 0) {
1974 apm_info.allow_ints = 1;
1975 printk(KERN_INFO "%s machine detected. "
1976 "Enabling interrupts during APM calls.\n", d->ident);
1981 /* Some APM bioses corrupt memory or just plain do not work */
1982 static int __init apm_is_horked(const struct dmi_system_id *d)
1984 if (apm_info.disabled == 0) {
1985 apm_info.disabled = 1;
1986 printk(KERN_INFO "%s machine detected. "
1987 "Disabling APM.\n", d->ident);
1992 static int __init apm_is_horked_d850md(const struct dmi_system_id *d)
1994 if (apm_info.disabled == 0) {
1995 apm_info.disabled = 1;
1996 printk(KERN_INFO "%s machine detected. "
1997 "Disabling APM.\n", d->ident);
1998 printk(KERN_INFO "This bug is fixed in bios P15 which is available for\n");
1999 printk(KERN_INFO "download from support.intel.com\n");
2004 /* Some APM bioses hang on APM idle calls */
2005 static int __init apm_likes_to_melt(const struct dmi_system_id *d)
2007 if (apm_info.forbid_idle == 0) {
2008 apm_info.forbid_idle = 1;
2009 printk(KERN_INFO "%s machine detected. "
2010 "Disabling APM idle calls.\n", d->ident);
2016 * Check for clue free BIOS implementations who use
2017 * the following QA technique
2019 * [ Write BIOS Code ]<------
2021 * < Does it Compile >----N--
2023 * < Does it Boot Win98 >-N--
2027 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
2028 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
2030 static int __init broken_apm_power(const struct dmi_system_id *d)
2032 apm_info.get_power_status_broken = 1;
2033 printk(KERN_WARNING "BIOS strings suggest APM bugs, "
2034 "disabling power status reporting.\n");
2039 * This bios swaps the APM minute reporting bytes over (Many sony laptops
2040 * have this problem).
2042 static int __init swab_apm_power_in_minutes(const struct dmi_system_id *d)
2044 apm_info.get_power_status_swabinminutes = 1;
2045 printk(KERN_WARNING "BIOS strings suggest APM reports battery life "
2046 "in minutes and wrong byte order.\n");
2050 static struct dmi_system_id __initdata apm_dmi_table[] = {
2053 KERN_WARNING "IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2054 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
2055 DMI_MATCH(DMI_BIOS_VERSION, "1AET38WW (1.01b)"), },
2057 { /* Handle problems with APM on the C600 */
2058 broken_ps2_resume, "Dell Latitude C600",
2059 { DMI_MATCH(DMI_SYS_VENDOR, "Dell"),
2060 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C600"), },
2062 { /* Allow interrupts during suspend on Dell Latitude laptops*/
2063 set_apm_ints, "Dell Latitude",
2064 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2065 DMI_MATCH(DMI_PRODUCT_NAME, "Latitude C510"), }
2068 apm_is_horked, "Dell Inspiron 2500",
2069 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2070 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2071 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2072 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2074 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
2075 set_apm_ints, "Dell Inspiron", {
2076 DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2077 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 4000"), },
2079 { /* Handle problems with APM on Inspiron 5000e */
2080 broken_apm_power, "Dell Inspiron 5000e",
2081 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2082 DMI_MATCH(DMI_BIOS_VERSION, "A04"),
2083 DMI_MATCH(DMI_BIOS_DATE, "08/24/2000"), },
2085 { /* Handle problems with APM on Inspiron 2500 */
2086 broken_apm_power, "Dell Inspiron 2500",
2087 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2088 DMI_MATCH(DMI_BIOS_VERSION, "A12"),
2089 DMI_MATCH(DMI_BIOS_DATE, "02/04/2002"), },
2092 apm_is_horked, "Dell Dimension 4100",
2093 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2094 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"),
2095 DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2096 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2098 { /* Allow interrupts during suspend on Compaq Laptops*/
2099 set_apm_ints, "Compaq 12XL125",
2100 { DMI_MATCH(DMI_SYS_VENDOR, "Compaq"),
2101 DMI_MATCH(DMI_PRODUCT_NAME, "Compaq PC"),
2102 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2103 DMI_MATCH(DMI_BIOS_VERSION, "4.06"), },
2105 { /* Allow interrupts during APM or the clock goes slow */
2106 set_apm_ints, "ASUSTeK",
2107 { DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
2108 DMI_MATCH(DMI_PRODUCT_NAME, "L8400K series Notebook PC"), },
2110 { /* APM blows on shutdown */
2111 apm_is_horked, "ABIT KX7-333[R]",
2112 { DMI_MATCH(DMI_BOARD_VENDOR, "ABIT"),
2113 DMI_MATCH(DMI_BOARD_NAME, "VT8367-8233A (KX7-333[R])"), },
2116 apm_is_horked, "Trigem Delhi3",
2117 { DMI_MATCH(DMI_SYS_VENDOR, "TriGem Computer, Inc"),
2118 DMI_MATCH(DMI_PRODUCT_NAME, "Delhi3"), },
2121 apm_is_horked, "Fujitsu-Siemens",
2122 { DMI_MATCH(DMI_BIOS_VENDOR, "hoenix/FUJITSU SIEMENS"),
2123 DMI_MATCH(DMI_BIOS_VERSION, "Version1.01"), },
2126 apm_is_horked_d850md, "Intel D850MD",
2127 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2128 DMI_MATCH(DMI_BIOS_VERSION, "MV85010A.86A.0016.P07.0201251536"), },
2131 apm_is_horked, "Intel D810EMO",
2132 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2133 DMI_MATCH(DMI_BIOS_VERSION, "MO81010A.86A.0008.P04.0004170800"), },
2136 apm_is_horked, "Dell XPS-Z",
2137 { DMI_MATCH(DMI_BIOS_VENDOR, "Intel Corp."),
2138 DMI_MATCH(DMI_BIOS_VERSION, "A11"),
2139 DMI_MATCH(DMI_PRODUCT_NAME, "XPS-Z"), },
2142 apm_is_horked, "Sharp PC-PJ/AX",
2143 { DMI_MATCH(DMI_SYS_VENDOR, "SHARP"),
2144 DMI_MATCH(DMI_PRODUCT_NAME, "PC-PJ/AX"),
2145 DMI_MATCH(DMI_BIOS_VENDOR, "SystemSoft"),
2146 DMI_MATCH(DMI_BIOS_VERSION, "Version R2.08"), },
2149 apm_is_horked, "Dell Inspiron 2500",
2150 { DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
2151 DMI_MATCH(DMI_PRODUCT_NAME, "Inspiron 2500"),
2152 DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2153 DMI_MATCH(DMI_BIOS_VERSION, "A11"), },
2155 { /* APM idle hangs */
2156 apm_likes_to_melt, "Jabil AMD",
2157 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2158 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP06"), },
2160 { /* APM idle hangs */
2161 apm_likes_to_melt, "AMI Bios",
2162 { DMI_MATCH(DMI_BIOS_VENDOR, "American Megatrends Inc."),
2163 DMI_MATCH(DMI_BIOS_VERSION, "0AASNP05"), },
2165 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2166 swab_apm_power_in_minutes, "Sony VAIO",
2167 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2168 DMI_MATCH(DMI_BIOS_VERSION, "R0206H"),
2169 DMI_MATCH(DMI_BIOS_DATE, "08/23/99"), },
2171 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2172 swab_apm_power_in_minutes, "Sony VAIO",
2173 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2174 DMI_MATCH(DMI_BIOS_VERSION, "W2K06H0"),
2175 DMI_MATCH(DMI_BIOS_DATE, "02/03/00"), },
2177 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2178 swab_apm_power_in_minutes, "Sony VAIO",
2179 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2180 DMI_MATCH(DMI_BIOS_VERSION, "R0117A0"),
2181 DMI_MATCH(DMI_BIOS_DATE, "04/25/00"), },
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, "R0121Z1"),
2187 DMI_MATCH(DMI_BIOS_DATE, "05/11/00"), },
2189 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2190 swab_apm_power_in_minutes, "Sony VAIO",
2191 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2192 DMI_MATCH(DMI_BIOS_VERSION, "WME01Z1"),
2193 DMI_MATCH(DMI_BIOS_DATE, "08/11/00"), },
2195 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2196 swab_apm_power_in_minutes, "Sony VAIO",
2197 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2198 DMI_MATCH(DMI_BIOS_VERSION, "R0206Z3"),
2199 DMI_MATCH(DMI_BIOS_DATE, "12/25/00"), },
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, "R0203D0"),
2205 DMI_MATCH(DMI_BIOS_DATE, "05/12/00"), },
2207 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2208 swab_apm_power_in_minutes, "Sony VAIO",
2209 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2210 DMI_MATCH(DMI_BIOS_VERSION, "R0203Z3"),
2211 DMI_MATCH(DMI_BIOS_DATE, "08/25/00"), },
2213 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2214 swab_apm_power_in_minutes, "Sony VAIO",
2215 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2216 DMI_MATCH(DMI_BIOS_VERSION, "R0209Z3"),
2217 DMI_MATCH(DMI_BIOS_DATE, "05/12/01"), },
2219 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2220 swab_apm_power_in_minutes, "Sony VAIO",
2221 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2222 DMI_MATCH(DMI_BIOS_VERSION, "R0204K2"),
2223 DMI_MATCH(DMI_BIOS_DATE, "08/28/00"), },
2226 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2227 swab_apm_power_in_minutes, "Sony VAIO",
2228 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2229 DMI_MATCH(DMI_BIOS_VERSION, "R0208P1"),
2230 DMI_MATCH(DMI_BIOS_DATE, "11/09/00"), },
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, "R0204P1"),
2236 DMI_MATCH(DMI_BIOS_DATE, "09/12/00"), },
2238 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2239 swab_apm_power_in_minutes, "Sony VAIO",
2240 { DMI_MATCH(DMI_BIOS_VENDOR, "Phoenix Technologies LTD"),
2241 DMI_MATCH(DMI_BIOS_VERSION, "WXPO1Z3"),
2242 DMI_MATCH(DMI_BIOS_DATE, "10/26/01"), },
2244 { /* broken PM poweroff bios */
2245 set_realmode_power_off, "Award Software v4.60 PGMA",
2246 { DMI_MATCH(DMI_BIOS_VENDOR, "Award Software International, Inc."),
2247 DMI_MATCH(DMI_BIOS_VERSION, "4.60 PGMA"),
2248 DMI_MATCH(DMI_BIOS_DATE, "134526184"), },
2251 /* Generic per vendor APM settings */
2253 { /* Allow interrupts during suspend on IBM laptops */
2254 set_apm_ints, "IBM",
2255 { DMI_MATCH(DMI_SYS_VENDOR, "IBM"), },
2262 * Just start the APM thread. We do NOT want to do APM BIOS
2263 * calls from anything but the APM thread, if for no other reason
2264 * than the fact that we don't trust the APM BIOS. This way,
2265 * most common APM BIOS problems that lead to protection errors
2266 * etc will have at least some level of being contained...
2268 * In short, if something bad happens, at least we have a choice
2269 * of just killing the apm thread..
2271 static int __init apm_init(void)
2273 struct desc_struct *gdt;
2276 dmi_check_system(apm_dmi_table);
2278 if (apm_info.bios.version == 0 || machine_is_olpc()) {
2279 printk(KERN_INFO "apm: BIOS not found.\n");
2283 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2284 ((apm_info.bios.version >> 8) & 0xff),
2285 (apm_info.bios.version & 0xff),
2286 apm_info.bios.flags,
2288 if ((apm_info.bios.flags & APM_32_BIT_SUPPORT) == 0) {
2289 printk(KERN_INFO "apm: no 32 bit BIOS support\n");
2294 apm_info.allow_ints = 1;
2296 apm_info.get_power_status_broken = 1;
2297 if (realmode_power_off)
2298 apm_info.realmode_power_off = 1;
2299 /* User can override, but default is to trust DMI */
2300 if (apm_disabled != -1)
2301 apm_info.disabled = apm_disabled;
2304 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2305 * but is reportedly a 1.0 BIOS.
2307 if (apm_info.bios.version == 0x001)
2308 apm_info.bios.version = 0x100;
2310 /* BIOS < 1.2 doesn't set cseg_16_len */
2311 if (apm_info.bios.version < 0x102)
2312 apm_info.bios.cseg_16_len = 0; /* 64k */
2315 printk(KERN_INFO "apm: entry %x:%x cseg16 %x dseg %x",
2316 apm_info.bios.cseg, apm_info.bios.offset,
2317 apm_info.bios.cseg_16, apm_info.bios.dseg);
2318 if (apm_info.bios.version > 0x100)
2319 printk(" cseg len %x, dseg len %x",
2320 apm_info.bios.cseg_len,
2321 apm_info.bios.dseg_len);
2322 if (apm_info.bios.version > 0x101)
2323 printk(" cseg16 len %x", apm_info.bios.cseg_16_len);
2327 if (apm_info.disabled) {
2328 pr_notice("disabled on user request.\n");
2331 if ((num_online_cpus() > 1) && !power_off && !smp) {
2332 pr_notice("disabled - APM is not SMP safe.\n");
2333 apm_info.disabled = 1;
2336 if (!acpi_disabled) {
2337 pr_notice("overridden by ACPI.\n");
2338 apm_info.disabled = 1;
2343 * Set up the long jump entry point to the APM BIOS, which is called
2344 * from inline assembly.
2346 apm_bios_entry.offset = apm_info.bios.offset;
2347 apm_bios_entry.segment = APM_CS;
2350 * The APM 1.1 BIOS is supposed to provide limit information that it
2351 * recognizes. Many machines do this correctly, but many others do
2352 * not restrict themselves to their claimed limit. When this happens,
2353 * they will cause a segmentation violation in the kernel at boot time.
2354 * Most BIOS's, however, will respect a 64k limit, so we use that.
2356 * Note we only set APM segments on CPU zero, since we pin the APM
2359 gdt = get_cpu_gdt_table(0);
2360 set_desc_base(&gdt[APM_CS >> 3],
2361 (unsigned long)__va((unsigned long)apm_info.bios.cseg << 4));
2362 set_desc_base(&gdt[APM_CS_16 >> 3],
2363 (unsigned long)__va((unsigned long)apm_info.bios.cseg_16 << 4));
2364 set_desc_base(&gdt[APM_DS >> 3],
2365 (unsigned long)__va((unsigned long)apm_info.bios.dseg << 4));
2367 proc_create("apm", 0, NULL, &apm_file_ops);
2369 kapmd_task = kthread_create(apm, NULL, "kapmd");
2370 if (IS_ERR(kapmd_task)) {
2371 pr_err("disabled - Unable to start kernel thread\n");
2372 err = PTR_ERR(kapmd_task);
2374 remove_proc_entry("apm", NULL);
2377 wake_up_process(kapmd_task);
2379 if (num_online_cpus() > 1 && !smp) {
2381 "apm: disabled - APM is not SMP safe (power off active).\n");
2386 * Note we don't actually care if the misc_device cannot be registered.
2387 * this driver can do its job without it, even if userspace can't
2388 * control it. just log the error
2390 if (misc_register(&apm_device))
2391 printk(KERN_WARNING "apm: Could not register misc device.\n");
2394 idle_period = (idle_period * HZ) / 100;
2395 if (idle_threshold < 100) {
2396 if (!cpuidle_register_driver(&apm_idle_driver))
2397 if (cpuidle_register_device(&apm_cpuidle_device))
2398 cpuidle_unregister_driver(&apm_idle_driver);
2404 static void __exit apm_exit(void)
2408 cpuidle_unregister_device(&apm_cpuidle_device);
2409 cpuidle_unregister_driver(&apm_idle_driver);
2411 if (((apm_info.bios.flags & APM_BIOS_DISENGAGED) == 0)
2412 && (apm_info.connection_version > 0x0100)) {
2413 error = apm_engage_power_management(APM_DEVICE_ALL, 0);
2415 apm_error("disengage power management", error);
2417 misc_deregister(&apm_device);
2418 remove_proc_entry("apm", NULL);
2420 pm_power_off = NULL;
2422 kthread_stop(kapmd_task);
2427 module_init(apm_init);
2428 module_exit(apm_exit);
2430 MODULE_AUTHOR("Stephen Rothwell");
2431 MODULE_DESCRIPTION("Advanced Power Management");
2432 MODULE_LICENSE("GPL");
2433 module_param(debug, bool, 0644);
2434 MODULE_PARM_DESC(debug, "Enable debug mode");
2435 module_param(power_off, bool, 0444);
2436 MODULE_PARM_DESC(power_off, "Enable power off");
2437 module_param(bounce_interval, int, 0444);
2438 MODULE_PARM_DESC(bounce_interval,
2439 "Set the number of ticks to ignore suspend bounces");
2440 module_param(allow_ints, bool, 0444);
2441 MODULE_PARM_DESC(allow_ints, "Allow interrupts during BIOS calls");
2442 module_param(broken_psr, bool, 0444);
2443 MODULE_PARM_DESC(broken_psr, "BIOS has a broken GetPowerStatus call");
2444 module_param(realmode_power_off, bool, 0444);
2445 MODULE_PARM_DESC(realmode_power_off,
2446 "Switch to real mode before powering off");
2447 module_param(idle_threshold, int, 0444);
2448 MODULE_PARM_DESC(idle_threshold,
2449 "System idle percentage above which to make APM BIOS idle calls");
2450 module_param(idle_period, int, 0444);
2451 MODULE_PARM_DESC(idle_period,
2452 "Period (in sec/100) over which to caculate the idle percentage");
2453 module_param(smp, bool, 0444);
2454 MODULE_PARM_DESC(smp,
2455 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2456 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV);