1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * APM BIOS driver for Linux
4 * Copyright 1994-2001 Stephen Rothwell (sfr@canb.auug.org.au)
6 * Initial development of this driver was funded by NEC Australia P/L
9 * October 1995, Rik Faith (faith@cs.unc.edu):
10 * Minor enhancements and updates (to the patch set) for 1.3.x
12 * January 1996, Rik Faith (faith@cs.unc.edu):
13 * Make /proc/apm easy to format (bump driver version)
14 * March 1996, Rik Faith (faith@cs.unc.edu):
15 * Prohibit APM BIOS calls unless apm_enabled.
16 * (Thanks to Ulrich Windl <Ulrich.Windl@rz.uni-regensburg.de>)
17 * April 1996, Stephen Rothwell (sfr@canb.auug.org.au)
19 * May 1996, Version 1.2
20 * Feb 1998, Version 1.3
21 * Feb 1998, Version 1.4
22 * Aug 1998, Version 1.5
23 * Sep 1998, Version 1.6
24 * Nov 1998, Version 1.7
25 * Jan 1999, Version 1.8
26 * Jan 1999, Version 1.9
27 * Oct 1999, Version 1.10
28 * Nov 1999, Version 1.11
29 * Jan 2000, Version 1.12
30 * Feb 2000, Version 1.13
31 * Nov 2000, Version 1.14
32 * Oct 2001, Version 1.15
33 * Jan 2002, Version 1.16
34 * Oct 2002, Version 1.16ac
37 * 0.6b: first version in official kernel, Linux 1.3.46
38 * 0.7: changed /proc/apm format, Linux 1.3.58
39 * 0.8: fixed gcc 2.7.[12] compilation problems, Linux 1.3.59
40 * 0.9: only call bios if bios is present, Linux 1.3.72
41 * 1.0: use fixed device number, consolidate /proc/apm into this file,
43 * 1.1: support user-space standby and suspend, power off after system
44 * halted, Linux 1.3.98
45 * 1.2: When resetting RTC after resume, take care so that the time
46 * is only incorrect by 30-60mS (vs. 1S previously) (Gabor J. Toth
47 * <jtoth@princeton.edu>); improve interaction between
48 * screen-blanking and gpm (Stephen Rothwell); Linux 1.99.4
49 * 1.2a:Simple change to stop mysterious bug reports with SMP also added
50 * levels to the printk calls. APM is not defined for SMP machines.
51 * The new replacement for it is, but Linux doesn't yet support this.
52 * Alan Cox Linux 2.1.55
53 * 1.3: Set up a valid data descriptor 0x40 for buggy BIOS's
54 * 1.4: Upgraded to support APM 1.2. Integrated ThinkPad suspend patch by
55 * Dean Gaudet <dgaudet@arctic.org>.
56 * C. Scott Ananian <cananian@alumni.princeton.edu> Linux 2.1.87
57 * 1.5: Fix segment register reloading (in case of bad segments saved
60 * 1.6: Cope with compiler/assembler differences.
61 * Only try to turn off the first display device.
62 * Fix OOPS at power off with no APM BIOS by Jan Echternach
63 * <echter@informatik.uni-rostock.de>
65 * 1.7: Modify driver's cached copy of the disabled/disengaged flags
66 * to reflect current state of APM BIOS.
67 * Chris Rankin <rankinc@bellsouth.net>
68 * Reset interrupt 0 timer to 100Hz after suspend
69 * Chad Miller <cmiller@surfsouth.com>
70 * Add CONFIG_APM_IGNORE_SUSPEND_BOUNCE
71 * Richard Gooch <rgooch@atnf.csiro.au>
72 * Allow boot time disabling of APM
73 * Make boot messages far less verbose by default
76 * 1.8: Add CONFIG_APM_RTC_IS_GMT
77 * Richard Gooch <rgooch@atnf.csiro.au>
78 * change APM_NOINTS to CONFIG_APM_ALLOW_INTS
79 * remove dependency on CONFIG_PROC_FS
81 * 1.9: Fix small typo. <laslo@wodip.opole.pl>
82 * Try to cope with BIOS's that need to have all display
83 * devices blanked and not just the first one.
84 * Ross Paterson <ross@soi.city.ac.uk>
85 * Fix segment limit setting it has always been wrong as
86 * the segments needed to have byte granularity.
87 * Mark a few things __init.
88 * Add hack to allow power off of SMP systems by popular request.
89 * Use CONFIG_SMP instead of __SMP__
90 * Ignore BOUNCES for three seconds.
92 * 1.10: Fix for Thinkpad return code.
93 * Merge 2.2 and 2.3 drivers.
94 * Remove APM dependencies in arch/i386/kernel/process.c
95 * Remove APM dependencies in drivers/char/sysrq.c
96 * Reset time across standby.
97 * Allow more initialisation on SMP.
98 * Remove CONFIG_APM_POWER_OFF and make it boot time
99 * configurable (default on).
100 * Make debug only a boot time parameter (remove APM_DEBUG).
101 * Try to blank all devices on any error.
102 * 1.11: Remove APM dependencies in drivers/char/console.c
103 * Check nr_running to detect if we are idle (from
104 * Borislav Deianov <borislav@lix.polytechnique.fr>)
105 * Fix for bioses that don't zero the top part of the
106 * entrypoint offset (Mario Sitta <sitta@al.unipmn.it>)
107 * (reported by Panos Katsaloulis <teras@writeme.com>).
108 * Real mode power off patch (Walter Hofmann
109 * <Walter.Hofmann@physik.stud.uni-erlangen.de>).
110 * 1.12: Remove CONFIG_SMP as the compiler will optimize
111 * the code away anyway (smp_num_cpus == 1 in UP)
112 * noted by Artur Skawina <skawina@geocities.com>.
113 * Make power off under SMP work again.
114 * Fix thinko with initial engaging of BIOS.
115 * Make sure power off only happens on CPU 0
116 * (Paul "Rusty" Russell <rusty@rustcorp.com.au>).
117 * Do error notification to user mode if BIOS calls fail.
118 * Move entrypoint offset fix to ...boot/setup.S
119 * where it belongs (Cosmos <gis88564@cis.nctu.edu.tw>).
120 * Remove smp-power-off. SMP users must now specify
121 * "apm=power-off" on the kernel command line. Suggested
122 * by Jim Avera <jima@hal.com>, modified by Alan Cox
123 * <alan@lxorguk.ukuu.org.uk>.
124 * Register the /proc/apm entry even on SMP so that
125 * scripts that check for it before doing power off
126 * work (Jim Avera <jima@hal.com>).
127 * 1.13: Changes for new pm_ interfaces (Andy Henroid
128 * <andy_henroid@yahoo.com>).
129 * Modularize the code.
130 * Fix the Thinkpad (again) :-( (CONFIG_APM_IGNORE_MULTIPLE_SUSPENDS
131 * is now the way life works).
132 * Fix thinko in suspend() (wrong return).
133 * Notify drivers on critical suspend.
134 * Make kapmd absorb more idle time (Pavel Machek <pavel@ucw.cz>
136 * Disable interrupts while we are suspended (Andy Henroid
137 * <andy_henroid@yahoo.com> fixed by sfr).
138 * Make power off work on SMP again (Tony Hoyle
139 * <tmh@magenta-logic.com> and <zlatko@iskon.hr>) modified by sfr.
140 * Remove CONFIG_APM_SUSPEND_BOUNCE. The bounce ignore
141 * interval is now configurable.
142 * 1.14: Make connection version persist across module unload/load.
143 * Enable and engage power management earlier.
144 * Disengage power management on module unload.
145 * Changed to use the sysrq-register hack for registering the
146 * power off function called by magic sysrq based upon discussions
147 * in irc://irc.openprojects.net/#kernelnewbies
148 * (Crutcher Dunnavant <crutcher+kernel@datastacks.com>).
149 * Make CONFIG_APM_REAL_MODE_POWER_OFF run time configurable.
150 * (Arjan van de Ven <arjanv@redhat.com>) modified by sfr.
151 * Work around byte swap bug in one of the Vaio's BIOS's
152 * (Marc Boucher <marc@mbsi.ca>).
153 * Exposed the disable flag to dmi so that we can handle known
154 * broken APM (Alan Cox <alan@lxorguk.ukuu.org.uk>).
155 * 1.14ac: If the BIOS says "I slowed the CPU down" then don't spin
156 * calling it - instead idle. (Alan Cox <alan@lxorguk.ukuu.org.uk>)
157 * If an APM idle fails log it and idle sensibly
158 * 1.15: Don't queue events to clients who open the device O_WRONLY.
159 * Don't expect replies from clients who open the device O_RDONLY.
160 * (Idea from Thomas Hood)
161 * Minor waitqueue cleanups. (John Fremlin <chief@bandits.org>)
162 * 1.16: Fix idle calling. (Andreas Steinmetz <ast@domdv.de> et al.)
163 * Notify listeners of standby or suspend events before notifying
164 * drivers. Return EBUSY to ioctl() if suspend is rejected.
165 * (Russell King <rmk@arm.linux.org.uk> and Thomas Hood)
166 * Ignore first resume after we generate our own resume event
167 * after a suspend (Thomas Hood)
168 * Daemonize now gets rid of our controlling terminal (sfr).
169 * CONFIG_APM_CPU_IDLE now just affects the default value of
170 * idle_threshold (sfr).
171 * Change name of kernel apm daemon (as it no longer idles) (sfr).
172 * 1.16ac: Fix up SMP support somewhat. You can now force SMP on and we
173 * make _all_ APM calls on the CPU#0. Fix unsafe sign bug.
174 * TODO: determine if its "boot CPU" or "CPU0" we want to lock to.
178 * Intel Corporation, Microsoft Corporation. Advanced Power Management
179 * (APM) BIOS Interface Specification, Revision 1.1, September 1993.
180 * Intel Order Number 241704-001. Microsoft Part Number 781-110-X01.
182 * [This document is available free from Intel by calling 800.628.8686 (fax
183 * 916.356.6100) or 800.548.4725; or from
184 * http://www.microsoft.com/whdc/archive/amp_12.mspx It is also
185 * available from Microsoft by calling 206.882.8080.]
188 * Intel Corporation, Microsoft Corporation. Advanced Power Management
189 * (APM) BIOS Interface Specification, Revision 1.2, February 1996.
191 * [This document is available from Microsoft at:
192 * http://www.microsoft.com/whdc/archive/amp_12.mspx]
195 #define pr_fmt(fmt) "apm: " fmt
197 #include <linux/module.h>
199 #include <linux/poll.h>
200 #include <linux/types.h>
201 #include <linux/stddef.h>
202 #include <linux/timer.h>
203 #include <linux/fcntl.h>
204 #include <linux/slab.h>
205 #include <linux/stat.h>
206 #include <linux/proc_fs.h>
207 #include <linux/seq_file.h>
208 #include <linux/miscdevice.h>
209 #include <linux/apm_bios.h>
210 #include <linux/init.h>
211 #include <linux/time.h>
212 #include <linux/sched/signal.h>
213 #include <linux/sched/cputime.h>
214 #include <linux/pm.h>
215 #include <linux/capability.h>
216 #include <linux/device.h>
217 #include <linux/kernel.h>
218 #include <linux/freezer.h>
219 #include <linux/smp.h>
220 #include <linux/dmi.h>
221 #include <linux/suspend.h>
222 #include <linux/kthread.h>
223 #include <linux/jiffies.h>
224 #include <linux/acpi.h>
225 #include <linux/syscore_ops.h>
226 #include <linux/i8253.h>
227 #include <linux/cpuidle.h>
229 #include <linux/uaccess.h>
230 #include <asm/desc.h>
231 #include <asm/olpc.h>
232 #include <asm/paravirt.h>
233 #include <asm/reboot.h>
234 #include <asm/nospec-branch.h>
237 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
238 extern int (*console_blank_hook
)(int);
242 * Various options can be changed at boot time as follows:
243 * (We allow underscores for compatibility with the modules code)
244 * apm=on/off enable/disable APM
245 * [no-]allow[-_]ints allow interrupts during BIOS calls
246 * [no-]broken[-_]psr BIOS has a broken GetPowerStatus call
247 * [no-]realmode[-_]power[-_]off switch to real mode before
249 * [no-]debug log some debugging messages
250 * [no-]power[-_]off power off on shutdown
251 * [no-]smp Use apm even on an SMP box
252 * bounce[-_]interval=<n> number of ticks to ignore suspend
254 * idle[-_]threshold=<n> System idle percentage above which to
255 * make APM BIOS idle calls. Set it to
257 * idle[-_]period=<n> Period (in 1/100s of a second) over
258 * which the idle percentage is
262 /* KNOWN PROBLEM MACHINES:
264 * U: TI 4000M TravelMate: BIOS is *NOT* APM compliant
265 * [Confirmed by TI representative]
266 * ?: ACER 486DX4/75: uses dseg 0040, in violation of APM specification
267 * [Confirmed by BIOS disassembly]
268 * [This may work now ...]
269 * P: Toshiba 1950S: battery life information only gets updated after resume
270 * P: Midwest Micro Soundbook Elite DX2/66 monochrome: screen blanking
271 * broken in BIOS [Reported by Garst R. Reese <reese@isn.net>]
272 * ?: AcerNote-950: oops on reading /proc/apm - workaround is a WIP
273 * Neale Banks <neale@lowendale.com.au> December 2000
275 * Legend: U = unusable with APM patches
276 * P = partially usable with APM patches
280 * Define as 1 to make the driver always call the APM BIOS busy
281 * routine even if the clock was not reported as slowed by the
282 * idle routine. Otherwise, define as 0.
284 #define ALWAYS_CALL_BUSY 1
287 * Define to make the APM BIOS calls zero all data segment registers (so
288 * that an incorrect BIOS implementation will cause a kernel panic if it
289 * tries to write to arbitrary memory).
291 #define APM_ZERO_SEGS
296 * Define to re-initialize the interrupt 0 timer to 100 Hz after a suspend.
297 * This patched by Chad Miller <cmiller@surfsouth.com>, original code by
298 * David Chen <chen@ctpa04.mit.edu>
300 #undef INIT_TIMER_AFTER_SUSPEND
302 #ifdef INIT_TIMER_AFTER_SUSPEND
303 #include <linux/timex.h>
305 #include <linux/delay.h>
309 * Need to poll the APM BIOS every second
311 #define APM_CHECK_TIMEOUT (HZ)
314 * Ignore suspend events for this amount of time after a resume
316 #define DEFAULT_BOUNCE_INTERVAL (3 * HZ)
319 * Maximum number of events stored
321 #define APM_MAX_EVENTS 20
324 * The per-file APM data
328 struct apm_user
*next
;
329 unsigned int suser
: 1;
330 unsigned int writer
: 1;
331 unsigned int reader
: 1;
332 unsigned int suspend_wait
: 1;
334 int suspends_pending
;
335 int standbys_pending
;
340 apm_event_t events
[APM_MAX_EVENTS
];
344 * The magic number in apm_user
346 #define APM_BIOS_MAGIC 0x4101
349 * idle percentage above which bios idle calls are done
351 #ifdef CONFIG_APM_CPU_IDLE
352 #define DEFAULT_IDLE_THRESHOLD 95
354 #define DEFAULT_IDLE_THRESHOLD 100
356 #define DEFAULT_IDLE_PERIOD (100 / 3)
358 static int apm_cpu_idle(struct cpuidle_device
*dev
,
359 struct cpuidle_driver
*drv
, int index
);
361 static struct cpuidle_driver apm_idle_driver
= {
363 .owner
= THIS_MODULE
,
365 { /* entry 0 is for polling */ },
366 { /* entry 1 is for APM idle */
369 .exit_latency
= 250, /* WAG */
370 .target_residency
= 500, /* WAG */
371 .enter
= &apm_cpu_idle
377 static struct cpuidle_device apm_cpuidle_device
;
383 unsigned long offset
;
384 unsigned short segment
;
386 static int clock_slowed
;
387 static int idle_threshold __read_mostly
= DEFAULT_IDLE_THRESHOLD
;
388 static int idle_period __read_mostly
= DEFAULT_IDLE_PERIOD
;
389 static int suspends_pending
;
390 static int standbys_pending
;
391 static int ignore_sys_suspend
;
392 static int ignore_normal_resume
;
393 static int bounce_interval __read_mostly
= DEFAULT_BOUNCE_INTERVAL
;
395 static bool debug __read_mostly
;
396 static bool smp __read_mostly
;
397 static int apm_disabled
= -1;
399 static bool power_off
;
401 static bool power_off
= 1;
403 static bool realmode_power_off
;
404 #ifdef CONFIG_APM_ALLOW_INTS
405 static bool allow_ints
= 1;
407 static bool allow_ints
;
409 static bool broken_psr
;
411 static DECLARE_WAIT_QUEUE_HEAD(apm_waitqueue
);
412 static DECLARE_WAIT_QUEUE_HEAD(apm_suspend_waitqueue
);
413 static struct apm_user
*user_list
;
414 static DEFINE_SPINLOCK(user_list_lock
);
415 static DEFINE_MUTEX(apm_mutex
);
418 * Set up a segment that references the real mode segment 0x40
419 * that extends up to the end of page zero (that we have reserved).
420 * This is for buggy BIOS's that refer to (real mode) segment 0x40
421 * even though they are called in protected mode.
423 static struct desc_struct bad_bios_desc
= GDT_ENTRY_INIT(DESC_DATA32_BIOS
,
424 (unsigned long)__va(0x400UL
), PAGE_SIZE
- 0x400 - 1);
426 static const char driver_version
[] = "1.16ac"; /* no spaces */
428 static struct task_struct
*kapmd_task
;
431 * APM event names taken from the APM 1.2 specification. These are
432 * the message codes that the BIOS uses to tell us about events
434 static const char * const apm_event_name
[] = {
440 "power status change",
445 "system standby resume",
446 "capabilities change"
448 #define NR_APM_EVENT_NAME ARRAY_SIZE(apm_event_name)
450 typedef struct lookup_t
{
456 * The BIOS returns a set of standard error codes in AX when the
460 static const lookup_t error_table
[] = {
461 /* N/A { APM_SUCCESS, "Operation succeeded" }, */
462 { APM_DISABLED
, "Power management disabled" },
463 { APM_CONNECTED
, "Real mode interface already connected" },
464 { APM_NOT_CONNECTED
, "Interface not connected" },
465 { APM_16_CONNECTED
, "16 bit interface already connected" },
466 /* N/A { APM_16_UNSUPPORTED, "16 bit interface not supported" }, */
467 { APM_32_CONNECTED
, "32 bit interface already connected" },
468 { APM_32_UNSUPPORTED
, "32 bit interface not supported" },
469 { APM_BAD_DEVICE
, "Unrecognized device ID" },
470 { APM_BAD_PARAM
, "Parameter out of range" },
471 { APM_NOT_ENGAGED
, "Interface not engaged" },
472 { APM_BAD_FUNCTION
, "Function not supported" },
473 { APM_RESUME_DISABLED
, "Resume timer disabled" },
474 { APM_BAD_STATE
, "Unable to enter requested state" },
475 /* N/A { APM_NO_EVENTS, "No events pending" }, */
476 { APM_NO_ERROR
, "BIOS did not set a return code" },
477 { APM_NOT_PRESENT
, "No APM present" }
479 #define ERROR_COUNT ARRAY_SIZE(error_table)
482 * apm_error - display an APM error
483 * @str: information string
484 * @err: APM BIOS return code
486 * Write a meaningful log entry to the kernel log in the event of
487 * an APM error. Note that this also handles (negative) kernel errors.
490 static void apm_error(char *str
, int err
)
494 for (i
= 0; i
< ERROR_COUNT
; i
++)
495 if (error_table
[i
].key
== err
)
498 pr_notice("%s: %s\n", str
, error_table
[i
].msg
);
500 pr_notice("%s: linux error code %i\n", str
, err
);
502 pr_notice("%s: unknown error code %#2.2x\n",
507 * These are the actual BIOS calls. Depending on APM_ZERO_SEGS and
508 * apm_info.allow_ints, we are being really paranoid here! Not only
509 * are interrupts disabled, but all the segment registers (except SS)
510 * are saved and zeroed this means that if the BIOS tries to reference
511 * any data without explicitly loading the segment registers, the kernel
512 * will fault immediately rather than have some unforeseen circumstances
513 * for the rest of the kernel. And it will be very obvious! :-) Doing
514 * this depends on CS referring to the same physical memory as DS so that
515 * DS can be zeroed before the call. Unfortunately, we can't do anything
516 * about the stack segment/pointer. Also, we tell the compiler that
517 * everything could change.
519 * Also, we KNOW that for the non error case of apm_bios_call, there
520 * is no useful data returned in the low order 8 bits of eax.
523 static inline unsigned long __apm_irq_save(void)
526 local_save_flags(flags
);
527 if (apm_info
.allow_ints
) {
528 if (irqs_disabled_flags(flags
))
536 #define apm_irq_save(flags) \
537 do { flags = __apm_irq_save(); } while (0)
539 static inline void apm_irq_restore(unsigned long flags
)
541 if (irqs_disabled_flags(flags
))
543 else if (irqs_disabled())
548 # define APM_DECL_SEGS \
549 unsigned int saved_fs; unsigned int saved_gs;
550 # define APM_DO_SAVE_SEGS \
551 savesegment(fs, saved_fs); savesegment(gs, saved_gs)
552 # define APM_DO_RESTORE_SEGS \
553 loadsegment(fs, saved_fs); loadsegment(gs, saved_gs)
555 # define APM_DECL_SEGS
556 # define APM_DO_SAVE_SEGS
557 # define APM_DO_RESTORE_SEGS
560 struct apm_bios_call
{
570 /* Error: -ENOMEM, or bits 8-15 of eax */
575 * __apm_bios_call - Make an APM BIOS 32bit call
576 * @_call: pointer to struct apm_bios_call.
578 * Make an APM call using the 32bit protected mode interface. The
579 * caller is responsible for knowing if APM BIOS is configured and
580 * enabled. This call can disable interrupts for a long period of
581 * time on some laptops. The return value is in AH and the carry
582 * flag is loaded into AL. If there is an error, then the error
583 * code is returned in AH (bits 8-15 of eax) and this function
586 * Note: this makes the call on the current CPU.
588 static long __apm_bios_call(void *_call
)
593 struct desc_struct save_desc_40
;
594 struct desc_struct
*gdt
;
595 struct apm_bios_call
*call
= _call
;
600 gdt
= get_cpu_gdt_rw(cpu
);
601 save_desc_40
= gdt
[0x40 / 8];
602 gdt
[0x40 / 8] = bad_bios_desc
;
605 firmware_restrict_branch_speculation_start();
606 ibt
= ibt_save(true);
608 apm_bios_call_asm(call
->func
, call
->ebx
, call
->ecx
,
609 &call
->eax
, &call
->ebx
, &call
->ecx
, &call
->edx
,
613 firmware_restrict_branch_speculation_end();
614 apm_irq_restore(flags
);
615 gdt
[0x40 / 8] = save_desc_40
;
618 return call
->eax
& 0xff;
621 /* Run __apm_bios_call or __apm_bios_call_simple on CPU 0 */
622 static int on_cpu0(long (*fn
)(void *), struct apm_bios_call
*call
)
626 /* Don't bother with work_on_cpu in the common case, so we don't
627 * have to worry about OOM or overhead. */
628 if (get_cpu() == 0) {
633 ret
= work_on_cpu(0, fn
, call
);
636 /* work_on_cpu can fail with -ENOMEM */
640 call
->err
= (call
->eax
>> 8) & 0xff;
646 * apm_bios_call - Make an APM BIOS 32bit call (on CPU 0)
647 * @call: the apm_bios_call registers.
649 * If there is an error, it is returned in @call.err.
651 static int apm_bios_call(struct apm_bios_call
*call
)
653 return on_cpu0(__apm_bios_call
, call
);
657 * __apm_bios_call_simple - Make an APM BIOS 32bit call (on CPU 0)
658 * @_call: pointer to struct apm_bios_call.
660 * Make a BIOS call that returns one value only, or just status.
661 * If there is an error, then the error code is returned in AH
662 * (bits 8-15 of eax) and this function returns non-zero (it can
663 * also return -ENOMEM). This is used for simpler BIOS operations.
664 * This call may hold interrupts off for a long time on some laptops.
666 * Note: this makes the call on the current CPU.
668 static long __apm_bios_call_simple(void *_call
)
674 struct desc_struct save_desc_40
;
675 struct desc_struct
*gdt
;
676 struct apm_bios_call
*call
= _call
;
681 gdt
= get_cpu_gdt_rw(cpu
);
682 save_desc_40
= gdt
[0x40 / 8];
683 gdt
[0x40 / 8] = bad_bios_desc
;
686 firmware_restrict_branch_speculation_start();
687 ibt
= ibt_save(true);
689 error
= apm_bios_call_simple_asm(call
->func
, call
->ebx
, call
->ecx
,
693 firmware_restrict_branch_speculation_end();
694 apm_irq_restore(flags
);
695 gdt
[0x40 / 8] = save_desc_40
;
701 * apm_bios_call_simple - make a simple APM BIOS 32bit call
702 * @func: APM function to invoke
703 * @ebx_in: EBX register value for BIOS call
704 * @ecx_in: ECX register value for BIOS call
705 * @eax: EAX register on return from the BIOS call
708 * Make a BIOS call that returns one value only, or just status.
709 * If there is an error, then the error code is returned in @err
710 * and this function returns non-zero. This is used for simpler
711 * BIOS operations. This call may hold interrupts off for a long
712 * time on some laptops.
714 static int apm_bios_call_simple(u32 func
, u32 ebx_in
, u32 ecx_in
, u32
*eax
,
717 struct apm_bios_call call
;
724 ret
= on_cpu0(__apm_bios_call_simple
, &call
);
731 * apm_driver_version - APM driver version
732 * @val: loaded with the APM version on return
734 * Retrieve the APM version supported by the BIOS. This is only
735 * supported for APM 1.1 or higher. An error indicates APM 1.0 is
738 * On entry val should point to a value indicating the APM driver
739 * version with the high byte being the major and the low byte the
740 * minor number both in BCD
742 * On return it will hold the BIOS revision supported in the
746 static int apm_driver_version(u_short
*val
)
751 if (apm_bios_call_simple(APM_FUNC_VERSION
, 0, *val
, &eax
, &err
))
758 * apm_get_event - get an APM event from the BIOS
759 * @event: pointer to the event
760 * @info: point to the event information
762 * The APM BIOS provides a polled information for event
763 * reporting. The BIOS expects to be polled at least every second
764 * when events are pending. When a message is found the caller should
765 * poll until no more messages are present. However, this causes
766 * problems on some laptops where a suspend event notification is
767 * not cleared until it is acknowledged.
769 * Additional information is returned in the info pointer, providing
770 * that APM 1.2 is in use. If no messages are pending the value 0x80
771 * is returned (No power management events pending).
773 static int apm_get_event(apm_event_t
*event
, apm_eventinfo_t
*info
)
775 struct apm_bios_call call
;
777 call
.func
= APM_FUNC_GET_EVENT
;
778 call
.ebx
= call
.ecx
= 0;
780 if (apm_bios_call(&call
))
784 if (apm_info
.connection_version
< 0x0102)
785 *info
= ~0; /* indicate info not valid */
792 * set_power_state - set the power management state
793 * @what: which items to transition
794 * @state: state to transition to
796 * Request an APM change of state for one or more system devices. The
797 * processor state must be transitioned last of all. what holds the
798 * class of device in the upper byte and the device number (0xFF for
799 * all) for the object to be transitioned.
801 * The state holds the state to transition to, which may in fact
802 * be an acceptance of a BIOS requested state change.
805 static int set_power_state(u_short what
, u_short state
)
810 if (apm_bios_call_simple(APM_FUNC_SET_STATE
, what
, state
, &eax
, &err
))
816 * set_system_power_state - set system wide power state
817 * @state: which state to enter
819 * Transition the entire system into a new APM power state.
822 static int set_system_power_state(u_short state
)
824 return set_power_state(APM_DEVICE_ALL
, state
);
828 * apm_do_idle - perform power saving
830 * This function notifies the BIOS that the processor is (in the view
831 * of the OS) idle. It returns -1 in the event that the BIOS refuses
832 * to handle the idle request. On a success the function returns 1
833 * if the BIOS did clock slowing or 0 otherwise.
836 static int apm_do_idle(void)
843 if (!need_resched()) {
845 ret
= apm_bios_call_simple(APM_FUNC_IDLE
, 0, 0, &eax
, &err
);
852 static unsigned long t
;
854 /* This always fails on some SMP boards running UP kernels.
855 * Only report the failure the first 5 times.
858 printk(KERN_DEBUG
"apm_do_idle failed (%d)\n", err
);
863 clock_slowed
= (apm_info
.bios
.flags
& APM_IDLE_SLOWS_CLOCK
) != 0;
868 * apm_do_busy - inform the BIOS the CPU is busy
870 * Request that the BIOS brings the CPU back to full performance.
873 static void apm_do_busy(void)
878 if (clock_slowed
|| ALWAYS_CALL_BUSY
) {
879 (void)apm_bios_call_simple(APM_FUNC_BUSY
, 0, 0, &dummy
, &err
);
885 * If no process has really been interested in
886 * the CPU for some time, we want to call BIOS
887 * power management - we probably want
890 #define IDLE_CALC_LIMIT (HZ * 100)
891 #define IDLE_LEAKY_MAX 16
894 * apm_cpu_idle - cpu idling for APM capable Linux
896 * This is the idling function the kernel executes when APM is available. It
897 * tries to do BIOS powermanagement based on the average system idle time.
898 * Furthermore it calls the system default idle routine.
901 static int apm_cpu_idle(struct cpuidle_device
*dev
,
902 struct cpuidle_driver
*drv
, int index
)
904 static int use_apm_idle
; /* = 0 */
905 static unsigned int last_jiffies
; /* = 0 */
906 static u64 last_stime
; /* = 0 */
909 int apm_idle_done
= 0;
910 unsigned int jiffies_since_last_check
= jiffies
- last_jiffies
;
914 task_cputime(current
, &utime
, &stime
);
915 if (jiffies_since_last_check
> IDLE_CALC_LIMIT
) {
917 } else if (jiffies_since_last_check
> idle_period
) {
918 unsigned int idle_percentage
;
920 idle_percentage
= nsecs_to_jiffies(stime
- last_stime
);
921 idle_percentage
*= 100;
922 idle_percentage
/= jiffies_since_last_check
;
923 use_apm_idle
= (idle_percentage
> idle_threshold
);
924 if (apm_info
.forbid_idle
)
928 last_jiffies
= jiffies
;
931 bucket
= IDLE_LEAKY_MAX
;
933 while (!need_resched()) {
938 switch (apm_do_idle()) {
943 bucket
= IDLE_LEAKY_MAX
;
954 default: /* BIOS refused */
960 jiffies_since_last_check
= jiffies
- last_jiffies
;
961 if (jiffies_since_last_check
> idle_period
)
972 * apm_power_off - ask the BIOS to power off
974 * Handle the power off sequence. This is the one piece of code we
975 * will execute even on SMP machines. In order to deal with BIOS
976 * bugs we support real mode APM BIOS power off calls. We also make
977 * the SMP call on CPU0 as some systems will only honour this call
978 * on their first cpu.
981 static void apm_power_off(void)
983 /* Some bioses don't like being called from CPU != 0 */
984 if (apm_info
.realmode_power_off
) {
985 set_cpus_allowed_ptr(current
, cpumask_of(0));
986 machine_real_restart(MRR_APM
);
988 (void)set_system_power_state(APM_STATE_OFF
);
992 #ifdef CONFIG_APM_DO_ENABLE
995 * apm_enable_power_management - enable BIOS APM power management
996 * @enable: enable yes/no
998 * Enable or disable the APM BIOS power services.
1001 static int apm_enable_power_management(int enable
)
1006 if ((enable
== 0) && (apm_info
.bios
.flags
& APM_BIOS_DISENGAGED
))
1007 return APM_NOT_ENGAGED
;
1008 if (apm_bios_call_simple(APM_FUNC_ENABLE_PM
, APM_DEVICE_BALL
,
1009 enable
, &eax
, &err
))
1012 apm_info
.bios
.flags
&= ~APM_BIOS_DISABLED
;
1014 apm_info
.bios
.flags
|= APM_BIOS_DISABLED
;
1020 * apm_get_power_status - get current power state
1021 * @status: returned status
1022 * @bat: battery info
1023 * @life: estimated life
1025 * Obtain the current power status from the APM BIOS. We return a
1026 * status which gives the rough battery status, and current power
1027 * source. The bat value returned give an estimate as a percentage
1028 * of life and a status value for the battery. The estimated life
1029 * if reported is a lifetime in seconds/minutes at current power
1033 static int apm_get_power_status(u_short
*status
, u_short
*bat
, u_short
*life
)
1035 struct apm_bios_call call
;
1037 call
.func
= APM_FUNC_GET_STATUS
;
1038 call
.ebx
= APM_DEVICE_ALL
;
1041 if (apm_info
.get_power_status_broken
)
1042 return APM_32_UNSUPPORTED
;
1043 if (apm_bios_call(&call
)) {
1045 return APM_NO_ERROR
;
1050 if (apm_info
.get_power_status_swabinminutes
) {
1051 *life
= swab16((u16
)call
.edx
);
1059 * apm_engage_power_management - enable PM on a device
1060 * @device: identity of device
1063 * Activate or deactivate power management on either a specific device
1064 * or the entire system (%APM_DEVICE_ALL).
1067 static int apm_engage_power_management(u_short device
, int enable
)
1072 if ((enable
== 0) && (device
== APM_DEVICE_ALL
)
1073 && (apm_info
.bios
.flags
& APM_BIOS_DISABLED
))
1074 return APM_DISABLED
;
1075 if (apm_bios_call_simple(APM_FUNC_ENGAGE_PM
, device
, enable
,
1078 if (device
== APM_DEVICE_ALL
) {
1080 apm_info
.bios
.flags
&= ~APM_BIOS_DISENGAGED
;
1082 apm_info
.bios
.flags
|= APM_BIOS_DISENGAGED
;
1087 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1090 * apm_console_blank - blank the display
1093 * Attempt to blank the console, firstly by blanking just video device
1094 * zero, and if that fails (some BIOSes don't support it) then it blanks
1095 * all video devices. Typically the BIOS will do laptop backlight and
1096 * monitor powerdown for us.
1099 static int apm_console_blank(int blank
)
1101 int error
= APM_NOT_ENGAGED
; /* silence gcc */
1104 static const u_short dev
[3] = { 0x100, 0x1FF, 0x101 };
1106 state
= blank
? APM_STATE_STANDBY
: APM_STATE_READY
;
1108 for (i
= 0; i
< ARRAY_SIZE(dev
); i
++) {
1109 error
= set_power_state(dev
[i
], state
);
1111 if ((error
== APM_SUCCESS
) || (error
== APM_NO_ERROR
))
1114 if (error
== APM_NOT_ENGAGED
)
1118 if (error
== APM_NOT_ENGAGED
) {
1122 eng_error
= apm_engage_power_management(APM_DEVICE_ALL
, 1);
1124 apm_error("set display", error
);
1125 apm_error("engage interface", eng_error
);
1128 return apm_console_blank(blank
);
1131 apm_error("set display", error
);
1136 static int queue_empty(struct apm_user
*as
)
1138 return as
->event_head
== as
->event_tail
;
1141 static apm_event_t
get_queued_event(struct apm_user
*as
)
1143 if (++as
->event_tail
>= APM_MAX_EVENTS
)
1145 return as
->events
[as
->event_tail
];
1148 static void queue_event(apm_event_t event
, struct apm_user
*sender
)
1150 struct apm_user
*as
;
1152 spin_lock(&user_list_lock
);
1153 if (user_list
== NULL
)
1155 for (as
= user_list
; as
!= NULL
; as
= as
->next
) {
1156 if ((as
== sender
) || (!as
->reader
))
1158 if (++as
->event_head
>= APM_MAX_EVENTS
)
1161 if (as
->event_head
== as
->event_tail
) {
1162 static int notified
;
1164 if (notified
++ == 0)
1165 pr_err("an event queue overflowed\n");
1166 if (++as
->event_tail
>= APM_MAX_EVENTS
)
1169 as
->events
[as
->event_head
] = event
;
1170 if (!as
->suser
|| !as
->writer
)
1173 case APM_SYS_SUSPEND
:
1174 case APM_USER_SUSPEND
:
1175 as
->suspends_pending
++;
1179 case APM_SYS_STANDBY
:
1180 case APM_USER_STANDBY
:
1181 as
->standbys_pending
++;
1186 wake_up_interruptible(&apm_waitqueue
);
1188 spin_unlock(&user_list_lock
);
1191 static void reinit_timer(void)
1193 #ifdef INIT_TIMER_AFTER_SUSPEND
1194 unsigned long flags
;
1196 raw_spin_lock_irqsave(&i8253_lock
, flags
);
1197 /* set the clock to HZ */
1198 outb_p(0x34, PIT_MODE
); /* binary, mode 2, LSB/MSB, ch 0 */
1200 outb_p(LATCH
& 0xff, PIT_CH0
); /* LSB */
1202 outb_p(LATCH
>> 8, PIT_CH0
); /* MSB */
1204 raw_spin_unlock_irqrestore(&i8253_lock
, flags
);
1208 static int suspend(int vetoable
)
1211 struct apm_user
*as
;
1213 dpm_suspend_start(PMSG_SUSPEND
);
1214 dpm_suspend_end(PMSG_SUSPEND
);
1216 local_irq_disable();
1221 save_processor_state();
1222 err
= set_system_power_state(APM_STATE_SUSPEND
);
1223 ignore_normal_resume
= 1;
1224 restore_processor_state();
1226 local_irq_disable();
1229 if (err
== APM_NO_ERROR
)
1231 if (err
!= APM_SUCCESS
)
1232 apm_error("suspend", err
);
1233 err
= (err
== APM_SUCCESS
) ? 0 : -EIO
;
1238 dpm_resume_start(PMSG_RESUME
);
1239 dpm_resume_end(PMSG_RESUME
);
1241 queue_event(APM_NORMAL_RESUME
, NULL
);
1242 spin_lock(&user_list_lock
);
1243 for (as
= user_list
; as
!= NULL
; as
= as
->next
) {
1244 as
->suspend_wait
= 0;
1245 as
->suspend_result
= err
;
1247 spin_unlock(&user_list_lock
);
1248 wake_up_interruptible(&apm_suspend_waitqueue
);
1252 static void standby(void)
1256 dpm_suspend_end(PMSG_SUSPEND
);
1258 local_irq_disable();
1262 err
= set_system_power_state(APM_STATE_STANDBY
);
1263 if ((err
!= APM_SUCCESS
) && (err
!= APM_NO_ERROR
))
1264 apm_error("standby", err
);
1266 local_irq_disable();
1270 dpm_resume_start(PMSG_RESUME
);
1273 static apm_event_t
get_event(void)
1276 apm_event_t event
= APM_NO_EVENTS
; /* silence gcc */
1277 apm_eventinfo_t info
;
1279 static int notified
;
1281 /* we don't use the eventinfo */
1282 error
= apm_get_event(&event
, &info
);
1283 if (error
== APM_SUCCESS
)
1286 if ((error
!= APM_NO_EVENTS
) && (notified
++ == 0))
1287 apm_error("get_event", error
);
1292 static void check_events(void)
1295 static unsigned long last_resume
;
1296 static int ignore_bounce
;
1298 while ((event
= get_event()) != 0) {
1300 if (event
<= NR_APM_EVENT_NAME
)
1301 printk(KERN_DEBUG
"apm: received %s notify\n",
1302 apm_event_name
[event
- 1]);
1304 printk(KERN_DEBUG
"apm: received unknown "
1305 "event 0x%02x\n", event
);
1308 && (time_after(jiffies
, last_resume
+ bounce_interval
)))
1312 case APM_SYS_STANDBY
:
1313 case APM_USER_STANDBY
:
1314 queue_event(event
, NULL
);
1315 if (standbys_pending
<= 0)
1319 case APM_USER_SUSPEND
:
1320 #ifdef CONFIG_APM_IGNORE_USER_SUSPEND
1321 if (apm_info
.connection_version
> 0x100)
1322 set_system_power_state(APM_STATE_REJECT
);
1325 case APM_SYS_SUSPEND
:
1326 if (ignore_bounce
) {
1327 if (apm_info
.connection_version
> 0x100)
1328 set_system_power_state(APM_STATE_REJECT
);
1332 * If we are already processing a SUSPEND,
1333 * then further SUSPEND events from the BIOS
1334 * will be ignored. We also return here to
1335 * cope with the fact that the Thinkpads keep
1336 * sending a SUSPEND event until something else
1339 if (ignore_sys_suspend
)
1341 ignore_sys_suspend
= 1;
1342 queue_event(event
, NULL
);
1343 if (suspends_pending
<= 0)
1347 case APM_NORMAL_RESUME
:
1348 case APM_CRITICAL_RESUME
:
1349 case APM_STANDBY_RESUME
:
1350 ignore_sys_suspend
= 0;
1351 last_resume
= jiffies
;
1353 if ((event
!= APM_NORMAL_RESUME
)
1354 || (ignore_normal_resume
== 0)) {
1355 dpm_resume_end(PMSG_RESUME
);
1356 queue_event(event
, NULL
);
1358 ignore_normal_resume
= 0;
1361 case APM_CAPABILITY_CHANGE
:
1362 case APM_LOW_BATTERY
:
1363 case APM_POWER_STATUS_CHANGE
:
1364 queue_event(event
, NULL
);
1365 /* If needed, notify drivers here */
1368 case APM_UPDATE_TIME
:
1371 case APM_CRITICAL_SUSPEND
:
1373 * We are not allowed to reject a critical suspend.
1381 static void apm_event_handler(void)
1383 static int pending_count
= 4;
1386 if ((standbys_pending
> 0) || (suspends_pending
> 0)) {
1387 if ((apm_info
.connection_version
> 0x100) &&
1388 (pending_count
-- <= 0)) {
1391 printk(KERN_DEBUG
"apm: setting state busy\n");
1392 err
= set_system_power_state(APM_STATE_BUSY
);
1394 apm_error("busy", err
);
1402 * This is the APM thread main loop.
1405 static void apm_mainloop(void)
1407 DECLARE_WAITQUEUE(wait
, current
);
1409 add_wait_queue(&apm_waitqueue
, &wait
);
1410 set_current_state(TASK_INTERRUPTIBLE
);
1412 schedule_timeout(APM_CHECK_TIMEOUT
);
1413 if (kthread_should_stop())
1416 * Ok, check all events, check for idle (and mark us sleeping
1417 * so as not to count towards the load average)..
1419 set_current_state(TASK_INTERRUPTIBLE
);
1420 apm_event_handler();
1422 remove_wait_queue(&apm_waitqueue
, &wait
);
1425 static int check_apm_user(struct apm_user
*as
, const char *func
)
1427 if (as
== NULL
|| as
->magic
!= APM_BIOS_MAGIC
) {
1428 pr_err("%s passed bad filp\n", func
);
1434 static ssize_t
do_read(struct file
*fp
, char __user
*buf
, size_t count
, loff_t
*ppos
)
1436 struct apm_user
*as
;
1440 as
= fp
->private_data
;
1441 if (check_apm_user(as
, "read"))
1443 if ((int)count
< sizeof(apm_event_t
))
1445 if ((queue_empty(as
)) && (fp
->f_flags
& O_NONBLOCK
))
1447 wait_event_interruptible(apm_waitqueue
, !queue_empty(as
));
1449 while ((i
>= sizeof(event
)) && !queue_empty(as
)) {
1450 event
= get_queued_event(as
);
1451 if (copy_to_user(buf
, &event
, sizeof(event
))) {
1457 case APM_SYS_SUSPEND
:
1458 case APM_USER_SUSPEND
:
1459 as
->suspends_read
++;
1462 case APM_SYS_STANDBY
:
1463 case APM_USER_STANDBY
:
1464 as
->standbys_read
++;
1467 buf
+= sizeof(event
);
1472 if (signal_pending(current
))
1473 return -ERESTARTSYS
;
1477 static __poll_t
do_poll(struct file
*fp
, poll_table
*wait
)
1479 struct apm_user
*as
;
1481 as
= fp
->private_data
;
1482 if (check_apm_user(as
, "poll"))
1484 poll_wait(fp
, &apm_waitqueue
, wait
);
1485 if (!queue_empty(as
))
1486 return EPOLLIN
| EPOLLRDNORM
;
1490 static long do_ioctl(struct file
*filp
, u_int cmd
, u_long arg
)
1492 struct apm_user
*as
;
1495 as
= filp
->private_data
;
1496 if (check_apm_user(as
, "ioctl"))
1498 if (!as
->suser
|| !as
->writer
)
1501 case APM_IOC_STANDBY
:
1502 mutex_lock(&apm_mutex
);
1503 if (as
->standbys_read
> 0) {
1504 as
->standbys_read
--;
1505 as
->standbys_pending
--;
1508 queue_event(APM_USER_STANDBY
, as
);
1509 if (standbys_pending
<= 0)
1511 mutex_unlock(&apm_mutex
);
1513 case APM_IOC_SUSPEND
:
1514 mutex_lock(&apm_mutex
);
1515 if (as
->suspends_read
> 0) {
1516 as
->suspends_read
--;
1517 as
->suspends_pending
--;
1520 queue_event(APM_USER_SUSPEND
, as
);
1521 if (suspends_pending
<= 0) {
1523 mutex_unlock(&apm_mutex
);
1525 as
->suspend_wait
= 1;
1526 mutex_unlock(&apm_mutex
);
1527 wait_event_interruptible(apm_suspend_waitqueue
,
1528 as
->suspend_wait
== 0);
1529 ret
= as
->suspend_result
;
1538 static int do_release(struct inode
*inode
, struct file
*filp
)
1540 struct apm_user
*as
;
1542 as
= filp
->private_data
;
1543 if (check_apm_user(as
, "release"))
1545 filp
->private_data
= NULL
;
1546 if (as
->standbys_pending
> 0) {
1547 standbys_pending
-= as
->standbys_pending
;
1548 if (standbys_pending
<= 0)
1551 if (as
->suspends_pending
> 0) {
1552 suspends_pending
-= as
->suspends_pending
;
1553 if (suspends_pending
<= 0)
1556 spin_lock(&user_list_lock
);
1557 if (user_list
== as
)
1558 user_list
= as
->next
;
1560 struct apm_user
*as1
;
1562 for (as1
= user_list
;
1563 (as1
!= NULL
) && (as1
->next
!= as
);
1567 pr_err("filp not in user list\n");
1569 as1
->next
= as
->next
;
1571 spin_unlock(&user_list_lock
);
1576 static int do_open(struct inode
*inode
, struct file
*filp
)
1578 struct apm_user
*as
;
1580 as
= kmalloc(sizeof(*as
), GFP_KERNEL
);
1584 as
->magic
= APM_BIOS_MAGIC
;
1585 as
->event_tail
= as
->event_head
= 0;
1586 as
->suspends_pending
= as
->standbys_pending
= 0;
1587 as
->suspends_read
= as
->standbys_read
= 0;
1589 * XXX - this is a tiny bit broken, when we consider BSD
1590 * process accounting. If the device is opened by root, we
1591 * instantly flag that we used superuser privs. Who knows,
1592 * we might close the device immediately without doing a
1593 * privileged operation -- cevans
1595 as
->suser
= capable(CAP_SYS_ADMIN
);
1596 as
->writer
= (filp
->f_mode
& FMODE_WRITE
) == FMODE_WRITE
;
1597 as
->reader
= (filp
->f_mode
& FMODE_READ
) == FMODE_READ
;
1598 spin_lock(&user_list_lock
);
1599 as
->next
= user_list
;
1601 spin_unlock(&user_list_lock
);
1602 filp
->private_data
= as
;
1606 #ifdef CONFIG_PROC_FS
1607 static int proc_apm_show(struct seq_file
*m
, void *v
)
1613 unsigned short ac_line_status
= 0xff;
1614 unsigned short battery_status
= 0xff;
1615 unsigned short battery_flag
= 0xff;
1616 int percentage
= -1;
1617 int time_units
= -1;
1620 if ((num_online_cpus() == 1) &&
1621 !(error
= apm_get_power_status(&bx
, &cx
, &dx
))) {
1622 ac_line_status
= (bx
>> 8) & 0xff;
1623 battery_status
= bx
& 0xff;
1624 if ((cx
& 0xff) != 0xff)
1625 percentage
= cx
& 0xff;
1627 if (apm_info
.connection_version
> 0x100) {
1628 battery_flag
= (cx
>> 8) & 0xff;
1630 units
= (dx
& 0x8000) ? "min" : "sec";
1631 time_units
= dx
& 0x7fff;
1635 /* Arguments, with symbols from linux/apm_bios.h. Information is
1636 from the Get Power Status (0x0a) call unless otherwise noted.
1638 0) Linux driver version (this will change if format changes)
1639 1) APM BIOS Version. Usually 1.0, 1.1 or 1.2.
1640 2) APM flags from APM Installation Check (0x00):
1641 bit 0: APM_16_BIT_SUPPORT
1642 bit 1: APM_32_BIT_SUPPORT
1643 bit 2: APM_IDLE_SLOWS_CLOCK
1644 bit 3: APM_BIOS_DISABLED
1645 bit 4: APM_BIOS_DISENGAGED
1649 0x02: On backup power (BIOS >= 1.1 only)
1656 0x04: Selected battery not present (BIOS >= 1.2 only)
1663 bit 7: No system battery
1665 6) Remaining battery life (percentage of charge):
1668 7) Remaining battery life (time units):
1669 Number of remaining minutes or seconds
1671 8) min = minutes; sec = seconds */
1673 seq_printf(m
, "%s %d.%d 0x%02x 0x%02x 0x%02x 0x%02x %d%% %d %s\n",
1675 (apm_info
.bios
.version
>> 8) & 0xff,
1676 apm_info
.bios
.version
& 0xff,
1677 apm_info
.bios
.flags
,
1688 static int apm(void *unused
)
1698 * This is to avoid random crashes at boot time during initialization
1699 * on SMP systems in case of "apm=power-off" mode. Seen on ASUS A7M266D.
1700 * Some bioses don't like being called from CPU != 0.
1701 * Method suggested by Ingo Molnar.
1703 set_cpus_allowed_ptr(current
, cpumask_of(0));
1704 BUG_ON(smp_processor_id() != 0);
1706 if (apm_info
.connection_version
== 0) {
1707 apm_info
.connection_version
= apm_info
.bios
.version
;
1708 if (apm_info
.connection_version
> 0x100) {
1710 * We only support BIOSs up to version 1.2
1712 if (apm_info
.connection_version
> 0x0102)
1713 apm_info
.connection_version
= 0x0102;
1714 error
= apm_driver_version(&apm_info
.connection_version
);
1715 if (error
!= APM_SUCCESS
) {
1716 apm_error("driver version", error
);
1717 /* Fall back to an APM 1.0 connection. */
1718 apm_info
.connection_version
= 0x100;
1724 printk(KERN_INFO
"apm: Connection version %d.%d\n",
1725 (apm_info
.connection_version
>> 8) & 0xff,
1726 apm_info
.connection_version
& 0xff);
1728 #ifdef CONFIG_APM_DO_ENABLE
1729 if (apm_info
.bios
.flags
& APM_BIOS_DISABLED
) {
1731 * This call causes my NEC UltraLite Versa 33/C to hang if it
1732 * is booted with PM disabled but not in the docking station.
1735 error
= apm_enable_power_management(1);
1737 apm_error("enable power management", error
);
1743 if ((apm_info
.bios
.flags
& APM_BIOS_DISENGAGED
)
1744 && (apm_info
.connection_version
> 0x0100)) {
1745 error
= apm_engage_power_management(APM_DEVICE_ALL
, 1);
1747 apm_error("engage power management", error
);
1752 if (debug
&& (num_online_cpus() == 1 || smp
)) {
1753 error
= apm_get_power_status(&bx
, &cx
, &dx
);
1755 printk(KERN_INFO
"apm: power status not available\n");
1757 switch ((bx
>> 8) & 0xff) {
1759 power_stat
= "off line";
1762 power_stat
= "on line";
1765 power_stat
= "on backup power";
1768 power_stat
= "unknown";
1771 switch (bx
& 0xff) {
1779 bat_stat
= "critical";
1782 bat_stat
= "charging";
1785 bat_stat
= "unknown";
1789 "apm: AC %s, battery status %s, battery life ",
1790 power_stat
, bat_stat
);
1791 if ((cx
& 0xff) == 0xff)
1792 printk("unknown\n");
1794 printk("%d%%\n", cx
& 0xff);
1795 if (apm_info
.connection_version
> 0x100) {
1797 "apm: battery flag 0x%02x, battery life ",
1800 printk("unknown\n");
1802 printk("%d %s\n", dx
& 0x7fff,
1804 "minutes" : "seconds");
1809 /* Install our power off handler.. */
1811 pm_power_off
= apm_power_off
;
1813 if (num_online_cpus() == 1 || smp
) {
1814 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1815 console_blank_hook
= apm_console_blank
;
1818 #if defined(CONFIG_APM_DISPLAY_BLANK) && defined(CONFIG_VT)
1819 console_blank_hook
= NULL
;
1827 static int __init
apm_setup(char *str
)
1831 while ((str
!= NULL
) && (*str
!= '\0')) {
1832 if (strncmp(str
, "off", 3) == 0)
1834 if (strncmp(str
, "on", 2) == 0)
1836 if ((strncmp(str
, "bounce-interval=", 16) == 0) ||
1837 (strncmp(str
, "bounce_interval=", 16) == 0))
1838 bounce_interval
= simple_strtol(str
+ 16, NULL
, 0);
1839 if ((strncmp(str
, "idle-threshold=", 15) == 0) ||
1840 (strncmp(str
, "idle_threshold=", 15) == 0))
1841 idle_threshold
= simple_strtol(str
+ 15, NULL
, 0);
1842 if ((strncmp(str
, "idle-period=", 12) == 0) ||
1843 (strncmp(str
, "idle_period=", 12) == 0))
1844 idle_period
= simple_strtol(str
+ 12, NULL
, 0);
1845 invert
= (strncmp(str
, "no-", 3) == 0) ||
1846 (strncmp(str
, "no_", 3) == 0);
1849 if (strncmp(str
, "debug", 5) == 0)
1851 if ((strncmp(str
, "power-off", 9) == 0) ||
1852 (strncmp(str
, "power_off", 9) == 0))
1853 power_off
= !invert
;
1854 if (strncmp(str
, "smp", 3) == 0) {
1856 idle_threshold
= 100;
1858 if ((strncmp(str
, "allow-ints", 10) == 0) ||
1859 (strncmp(str
, "allow_ints", 10) == 0))
1860 apm_info
.allow_ints
= !invert
;
1861 if ((strncmp(str
, "broken-psr", 10) == 0) ||
1862 (strncmp(str
, "broken_psr", 10) == 0))
1863 apm_info
.get_power_status_broken
= !invert
;
1864 if ((strncmp(str
, "realmode-power-off", 18) == 0) ||
1865 (strncmp(str
, "realmode_power_off", 18) == 0))
1866 apm_info
.realmode_power_off
= !invert
;
1867 str
= strchr(str
, ',');
1869 str
+= strspn(str
, ", \t");
1874 __setup("apm=", apm_setup
);
1877 static const struct file_operations apm_bios_fops
= {
1878 .owner
= THIS_MODULE
,
1881 .unlocked_ioctl
= do_ioctl
,
1883 .release
= do_release
,
1884 .llseek
= noop_llseek
,
1887 static struct miscdevice apm_device
= {
1894 /* Simple "print if true" callback */
1895 static int __init
print_if_true(const struct dmi_system_id
*d
)
1897 printk("%s\n", d
->ident
);
1902 * Some Bioses enable the PS/2 mouse (touchpad) at resume, even if it was
1903 * disabled before the suspend. Linux used to get terribly confused by that.
1905 static int __init
broken_ps2_resume(const struct dmi_system_id
*d
)
1907 printk(KERN_INFO
"%s machine detected. Mousepad Resume Bug "
1908 "workaround hopefully not needed.\n", d
->ident
);
1912 /* Some bioses have a broken protected mode poweroff and need to use realmode */
1913 static int __init
set_realmode_power_off(const struct dmi_system_id
*d
)
1915 if (apm_info
.realmode_power_off
== 0) {
1916 apm_info
.realmode_power_off
= 1;
1917 printk(KERN_INFO
"%s bios detected. "
1918 "Using realmode poweroff only.\n", d
->ident
);
1923 /* Some laptops require interrupts to be enabled during APM calls */
1924 static int __init
set_apm_ints(const struct dmi_system_id
*d
)
1926 if (apm_info
.allow_ints
== 0) {
1927 apm_info
.allow_ints
= 1;
1928 printk(KERN_INFO
"%s machine detected. "
1929 "Enabling interrupts during APM calls.\n", d
->ident
);
1934 /* Some APM bioses corrupt memory or just plain do not work */
1935 static int __init
apm_is_horked(const struct dmi_system_id
*d
)
1937 if (apm_info
.disabled
== 0) {
1938 apm_info
.disabled
= 1;
1939 printk(KERN_INFO
"%s machine detected. "
1940 "Disabling APM.\n", d
->ident
);
1945 static int __init
apm_is_horked_d850md(const struct dmi_system_id
*d
)
1947 if (apm_info
.disabled
== 0) {
1948 apm_info
.disabled
= 1;
1949 printk(KERN_INFO
"%s machine detected. "
1950 "Disabling APM.\n", d
->ident
);
1951 printk(KERN_INFO
"This bug is fixed in bios P15 which is available for\n");
1952 printk(KERN_INFO
"download from support.intel.com\n");
1957 /* Some APM bioses hang on APM idle calls */
1958 static int __init
apm_likes_to_melt(const struct dmi_system_id
*d
)
1960 if (apm_info
.forbid_idle
== 0) {
1961 apm_info
.forbid_idle
= 1;
1962 printk(KERN_INFO
"%s machine detected. "
1963 "Disabling APM idle calls.\n", d
->ident
);
1969 * Check for clue free BIOS implementations who use
1970 * the following QA technique
1972 * [ Write BIOS Code ]<------
1974 * < Does it Compile >----N--
1976 * < Does it Boot Win98 >-N--
1980 * Phoenix A04 08/24/2000 is known bad (Dell Inspiron 5000e)
1981 * Phoenix A07 09/29/2000 is known good (Dell Inspiron 5000)
1983 static int __init
broken_apm_power(const struct dmi_system_id
*d
)
1985 apm_info
.get_power_status_broken
= 1;
1986 printk(KERN_WARNING
"BIOS strings suggest APM bugs, "
1987 "disabling power status reporting.\n");
1992 * This bios swaps the APM minute reporting bytes over (Many sony laptops
1993 * have this problem).
1995 static int __init
swab_apm_power_in_minutes(const struct dmi_system_id
*d
)
1997 apm_info
.get_power_status_swabinminutes
= 1;
1998 printk(KERN_WARNING
"BIOS strings suggest APM reports battery life "
1999 "in minutes and wrong byte order.\n");
2003 static const struct dmi_system_id apm_dmi_table
[] __initconst
= {
2006 KERN_WARNING
"IBM T23 - BIOS 1.03b+ and controller firmware 1.02+ may be needed for Linux APM.",
2007 { DMI_MATCH(DMI_SYS_VENDOR
, "IBM"),
2008 DMI_MATCH(DMI_BIOS_VERSION
, "1AET38WW (1.01b)"), },
2010 { /* Handle problems with APM on the C600 */
2011 broken_ps2_resume
, "Dell Latitude C600",
2012 { DMI_MATCH(DMI_SYS_VENDOR
, "Dell"),
2013 DMI_MATCH(DMI_PRODUCT_NAME
, "Latitude C600"), },
2015 { /* Allow interrupts during suspend on Dell Latitude laptops*/
2016 set_apm_ints
, "Dell Latitude",
2017 { DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer Corporation"),
2018 DMI_MATCH(DMI_PRODUCT_NAME
, "Latitude C510"), }
2021 apm_is_horked
, "Dell Inspiron 2500",
2022 { DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer Corporation"),
2023 DMI_MATCH(DMI_PRODUCT_NAME
, "Inspiron 2500"),
2024 DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2025 DMI_MATCH(DMI_BIOS_VERSION
, "A11"), },
2027 { /* Allow interrupts during suspend on Dell Inspiron laptops*/
2028 set_apm_ints
, "Dell Inspiron", {
2029 DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer Corporation"),
2030 DMI_MATCH(DMI_PRODUCT_NAME
, "Inspiron 4000"), },
2032 { /* Handle problems with APM on Inspiron 5000e */
2033 broken_apm_power
, "Dell Inspiron 5000e",
2034 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2035 DMI_MATCH(DMI_BIOS_VERSION
, "A04"),
2036 DMI_MATCH(DMI_BIOS_DATE
, "08/24/2000"), },
2038 { /* Handle problems with APM on Inspiron 2500 */
2039 broken_apm_power
, "Dell Inspiron 2500",
2040 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2041 DMI_MATCH(DMI_BIOS_VERSION
, "A12"),
2042 DMI_MATCH(DMI_BIOS_DATE
, "02/04/2002"), },
2045 apm_is_horked
, "Dell Dimension 4100",
2046 { DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer Corporation"),
2047 DMI_MATCH(DMI_PRODUCT_NAME
, "XPS-Z"),
2048 DMI_MATCH(DMI_BIOS_VENDOR
, "Intel Corp."),
2049 DMI_MATCH(DMI_BIOS_VERSION
, "A11"), },
2051 { /* Allow interrupts during suspend on Compaq Laptops*/
2052 set_apm_ints
, "Compaq 12XL125",
2053 { DMI_MATCH(DMI_SYS_VENDOR
, "Compaq"),
2054 DMI_MATCH(DMI_PRODUCT_NAME
, "Compaq PC"),
2055 DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2056 DMI_MATCH(DMI_BIOS_VERSION
, "4.06"), },
2058 { /* Allow interrupts during APM or the clock goes slow */
2059 set_apm_ints
, "ASUSTeK",
2060 { DMI_MATCH(DMI_SYS_VENDOR
, "ASUSTeK Computer Inc."),
2061 DMI_MATCH(DMI_PRODUCT_NAME
, "L8400K series Notebook PC"), },
2063 { /* APM blows on shutdown */
2064 apm_is_horked
, "ABIT KX7-333[R]",
2065 { DMI_MATCH(DMI_BOARD_VENDOR
, "ABIT"),
2066 DMI_MATCH(DMI_BOARD_NAME
, "VT8367-8233A (KX7-333[R])"), },
2069 apm_is_horked
, "Trigem Delhi3",
2070 { DMI_MATCH(DMI_SYS_VENDOR
, "TriGem Computer, Inc"),
2071 DMI_MATCH(DMI_PRODUCT_NAME
, "Delhi3"), },
2074 apm_is_horked
, "Fujitsu-Siemens",
2075 { DMI_MATCH(DMI_BIOS_VENDOR
, "hoenix/FUJITSU SIEMENS"),
2076 DMI_MATCH(DMI_BIOS_VERSION
, "Version1.01"), },
2079 apm_is_horked_d850md
, "Intel D850MD",
2080 { DMI_MATCH(DMI_BIOS_VENDOR
, "Intel Corp."),
2081 DMI_MATCH(DMI_BIOS_VERSION
, "MV85010A.86A.0016.P07.0201251536"), },
2084 apm_is_horked
, "Intel D810EMO",
2085 { DMI_MATCH(DMI_BIOS_VENDOR
, "Intel Corp."),
2086 DMI_MATCH(DMI_BIOS_VERSION
, "MO81010A.86A.0008.P04.0004170800"), },
2089 apm_is_horked
, "Dell XPS-Z",
2090 { DMI_MATCH(DMI_BIOS_VENDOR
, "Intel Corp."),
2091 DMI_MATCH(DMI_BIOS_VERSION
, "A11"),
2092 DMI_MATCH(DMI_PRODUCT_NAME
, "XPS-Z"), },
2095 apm_is_horked
, "Sharp PC-PJ/AX",
2096 { DMI_MATCH(DMI_SYS_VENDOR
, "SHARP"),
2097 DMI_MATCH(DMI_PRODUCT_NAME
, "PC-PJ/AX"),
2098 DMI_MATCH(DMI_BIOS_VENDOR
, "SystemSoft"),
2099 DMI_MATCH(DMI_BIOS_VERSION
, "Version R2.08"), },
2102 apm_is_horked
, "Dell Inspiron 2500",
2103 { DMI_MATCH(DMI_SYS_VENDOR
, "Dell Computer Corporation"),
2104 DMI_MATCH(DMI_PRODUCT_NAME
, "Inspiron 2500"),
2105 DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2106 DMI_MATCH(DMI_BIOS_VERSION
, "A11"), },
2108 { /* APM idle hangs */
2109 apm_likes_to_melt
, "Jabil AMD",
2110 { DMI_MATCH(DMI_BIOS_VENDOR
, "American Megatrends Inc."),
2111 DMI_MATCH(DMI_BIOS_VERSION
, "0AASNP06"), },
2113 { /* APM idle hangs */
2114 apm_likes_to_melt
, "AMI Bios",
2115 { DMI_MATCH(DMI_BIOS_VENDOR
, "American Megatrends Inc."),
2116 DMI_MATCH(DMI_BIOS_VERSION
, "0AASNP05"), },
2118 { /* Handle problems with APM on Sony Vaio PCG-N505X(DE) */
2119 swab_apm_power_in_minutes
, "Sony VAIO",
2120 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2121 DMI_MATCH(DMI_BIOS_VERSION
, "R0206H"),
2122 DMI_MATCH(DMI_BIOS_DATE
, "08/23/99"), },
2124 { /* Handle problems with APM on Sony Vaio PCG-N505VX */
2125 swab_apm_power_in_minutes
, "Sony VAIO",
2126 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2127 DMI_MATCH(DMI_BIOS_VERSION
, "W2K06H0"),
2128 DMI_MATCH(DMI_BIOS_DATE
, "02/03/00"), },
2130 { /* Handle problems with APM on Sony Vaio PCG-XG29 */
2131 swab_apm_power_in_minutes
, "Sony VAIO",
2132 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2133 DMI_MATCH(DMI_BIOS_VERSION
, "R0117A0"),
2134 DMI_MATCH(DMI_BIOS_DATE
, "04/25/00"), },
2136 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2137 swab_apm_power_in_minutes
, "Sony VAIO",
2138 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2139 DMI_MATCH(DMI_BIOS_VERSION
, "R0121Z1"),
2140 DMI_MATCH(DMI_BIOS_DATE
, "05/11/00"), },
2142 { /* Handle problems with APM on Sony Vaio PCG-Z600NE */
2143 swab_apm_power_in_minutes
, "Sony VAIO",
2144 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2145 DMI_MATCH(DMI_BIOS_VERSION
, "WME01Z1"),
2146 DMI_MATCH(DMI_BIOS_DATE
, "08/11/00"), },
2148 { /* Handle problems with APM on Sony Vaio PCG-Z600LEK(DE) */
2149 swab_apm_power_in_minutes
, "Sony VAIO",
2150 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2151 DMI_MATCH(DMI_BIOS_VERSION
, "R0206Z3"),
2152 DMI_MATCH(DMI_BIOS_DATE
, "12/25/00"), },
2154 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2155 swab_apm_power_in_minutes
, "Sony VAIO",
2156 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2157 DMI_MATCH(DMI_BIOS_VERSION
, "R0203D0"),
2158 DMI_MATCH(DMI_BIOS_DATE
, "05/12/00"), },
2160 { /* Handle problems with APM on Sony Vaio PCG-Z505LS */
2161 swab_apm_power_in_minutes
, "Sony VAIO",
2162 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2163 DMI_MATCH(DMI_BIOS_VERSION
, "R0203Z3"),
2164 DMI_MATCH(DMI_BIOS_DATE
, "08/25/00"), },
2166 { /* Handle problems with APM on Sony Vaio PCG-Z505LS (with updated BIOS) */
2167 swab_apm_power_in_minutes
, "Sony VAIO",
2168 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2169 DMI_MATCH(DMI_BIOS_VERSION
, "R0209Z3"),
2170 DMI_MATCH(DMI_BIOS_DATE
, "05/12/01"), },
2172 { /* Handle problems with APM on Sony Vaio PCG-F104K */
2173 swab_apm_power_in_minutes
, "Sony VAIO",
2174 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2175 DMI_MATCH(DMI_BIOS_VERSION
, "R0204K2"),
2176 DMI_MATCH(DMI_BIOS_DATE
, "08/28/00"), },
2179 { /* Handle problems with APM on Sony Vaio PCG-C1VN/C1VE */
2180 swab_apm_power_in_minutes
, "Sony VAIO",
2181 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2182 DMI_MATCH(DMI_BIOS_VERSION
, "R0208P1"),
2183 DMI_MATCH(DMI_BIOS_DATE
, "11/09/00"), },
2185 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2186 swab_apm_power_in_minutes
, "Sony VAIO",
2187 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2188 DMI_MATCH(DMI_BIOS_VERSION
, "R0204P1"),
2189 DMI_MATCH(DMI_BIOS_DATE
, "09/12/00"), },
2191 { /* Handle problems with APM on Sony Vaio PCG-C1VE */
2192 swab_apm_power_in_minutes
, "Sony VAIO",
2193 { DMI_MATCH(DMI_BIOS_VENDOR
, "Phoenix Technologies LTD"),
2194 DMI_MATCH(DMI_BIOS_VERSION
, "WXPO1Z3"),
2195 DMI_MATCH(DMI_BIOS_DATE
, "10/26/01"), },
2197 { /* broken PM poweroff bios */
2198 set_realmode_power_off
, "Award Software v4.60 PGMA",
2199 { DMI_MATCH(DMI_BIOS_VENDOR
, "Award Software International, Inc."),
2200 DMI_MATCH(DMI_BIOS_VERSION
, "4.60 PGMA"),
2201 DMI_MATCH(DMI_BIOS_DATE
, "134526184"), },
2204 /* Generic per vendor APM settings */
2206 { /* Allow interrupts during suspend on IBM laptops */
2207 set_apm_ints
, "IBM",
2208 { DMI_MATCH(DMI_SYS_VENDOR
, "IBM"), },
2215 * Just start the APM thread. We do NOT want to do APM BIOS
2216 * calls from anything but the APM thread, if for no other reason
2217 * than the fact that we don't trust the APM BIOS. This way,
2218 * most common APM BIOS problems that lead to protection errors
2219 * etc will have at least some level of being contained...
2221 * In short, if something bad happens, at least we have a choice
2222 * of just killing the apm thread..
2224 static int __init
apm_init(void)
2226 struct desc_struct
*gdt
;
2229 dmi_check_system(apm_dmi_table
);
2231 if (apm_info
.bios
.version
== 0 || machine_is_olpc()) {
2232 printk(KERN_INFO
"apm: BIOS not found.\n");
2236 "apm: BIOS version %d.%d Flags 0x%02x (Driver version %s)\n",
2237 ((apm_info
.bios
.version
>> 8) & 0xff),
2238 (apm_info
.bios
.version
& 0xff),
2239 apm_info
.bios
.flags
,
2241 if ((apm_info
.bios
.flags
& APM_32_BIT_SUPPORT
) == 0) {
2242 printk(KERN_INFO
"apm: no 32 bit BIOS support\n");
2247 apm_info
.allow_ints
= 1;
2249 apm_info
.get_power_status_broken
= 1;
2250 if (realmode_power_off
)
2251 apm_info
.realmode_power_off
= 1;
2252 /* User can override, but default is to trust DMI */
2253 if (apm_disabled
!= -1)
2254 apm_info
.disabled
= apm_disabled
;
2257 * Fix for the Compaq Contura 3/25c which reports BIOS version 0.1
2258 * but is reportedly a 1.0 BIOS.
2260 if (apm_info
.bios
.version
== 0x001)
2261 apm_info
.bios
.version
= 0x100;
2263 /* BIOS < 1.2 doesn't set cseg_16_len */
2264 if (apm_info
.bios
.version
< 0x102)
2265 apm_info
.bios
.cseg_16_len
= 0; /* 64k */
2268 printk(KERN_INFO
"apm: entry %x:%x cseg16 %x dseg %x",
2269 apm_info
.bios
.cseg
, apm_info
.bios
.offset
,
2270 apm_info
.bios
.cseg_16
, apm_info
.bios
.dseg
);
2271 if (apm_info
.bios
.version
> 0x100)
2272 printk(" cseg len %x, dseg len %x",
2273 apm_info
.bios
.cseg_len
,
2274 apm_info
.bios
.dseg_len
);
2275 if (apm_info
.bios
.version
> 0x101)
2276 printk(" cseg16 len %x", apm_info
.bios
.cseg_16_len
);
2280 if (apm_info
.disabled
) {
2281 pr_notice("disabled on user request.\n");
2284 if ((num_online_cpus() > 1) && !power_off
&& !smp
) {
2285 pr_notice("disabled - APM is not SMP safe.\n");
2286 apm_info
.disabled
= 1;
2289 if (!acpi_disabled
) {
2290 pr_notice("overridden by ACPI.\n");
2291 apm_info
.disabled
= 1;
2296 * Set up the long jump entry point to the APM BIOS, which is called
2297 * from inline assembly.
2299 apm_bios_entry
.offset
= apm_info
.bios
.offset
;
2300 apm_bios_entry
.segment
= APM_CS
;
2303 * The APM 1.1 BIOS is supposed to provide limit information that it
2304 * recognizes. Many machines do this correctly, but many others do
2305 * not restrict themselves to their claimed limit. When this happens,
2306 * they will cause a segmentation violation in the kernel at boot time.
2307 * Most BIOS's, however, will respect a 64k limit, so we use that.
2309 * Note we only set APM segments on CPU zero, since we pin the APM
2312 gdt
= get_cpu_gdt_rw(0);
2313 set_desc_base(&gdt
[APM_CS
>> 3],
2314 (unsigned long)__va((unsigned long)apm_info
.bios
.cseg
<< 4));
2315 set_desc_base(&gdt
[APM_CS_16
>> 3],
2316 (unsigned long)__va((unsigned long)apm_info
.bios
.cseg_16
<< 4));
2317 set_desc_base(&gdt
[APM_DS
>> 3],
2318 (unsigned long)__va((unsigned long)apm_info
.bios
.dseg
<< 4));
2320 proc_create_single("apm", 0, NULL
, proc_apm_show
);
2322 kapmd_task
= kthread_create(apm
, NULL
, "kapmd");
2323 if (IS_ERR(kapmd_task
)) {
2324 pr_err("disabled - Unable to start kernel thread\n");
2325 err
= PTR_ERR(kapmd_task
);
2327 remove_proc_entry("apm", NULL
);
2330 wake_up_process(kapmd_task
);
2332 if (num_online_cpus() > 1 && !smp
) {
2334 "apm: disabled - APM is not SMP safe (power off active).\n");
2339 * Note we don't actually care if the misc_device cannot be registered.
2340 * this driver can do its job without it, even if userspace can't
2341 * control it. just log the error
2343 if (misc_register(&apm_device
))
2344 printk(KERN_WARNING
"apm: Could not register misc device.\n");
2347 idle_period
= (idle_period
* HZ
) / 100;
2348 if (idle_threshold
< 100) {
2349 cpuidle_poll_state_init(&apm_idle_driver
);
2350 if (!cpuidle_register_driver(&apm_idle_driver
))
2351 if (cpuidle_register_device(&apm_cpuidle_device
))
2352 cpuidle_unregister_driver(&apm_idle_driver
);
2358 static void __exit
apm_exit(void)
2362 cpuidle_unregister_device(&apm_cpuidle_device
);
2363 cpuidle_unregister_driver(&apm_idle_driver
);
2365 if (((apm_info
.bios
.flags
& APM_BIOS_DISENGAGED
) == 0)
2366 && (apm_info
.connection_version
> 0x0100)) {
2367 error
= apm_engage_power_management(APM_DEVICE_ALL
, 0);
2369 apm_error("disengage power management", error
);
2371 misc_deregister(&apm_device
);
2372 remove_proc_entry("apm", NULL
);
2374 pm_power_off
= NULL
;
2376 kthread_stop(kapmd_task
);
2381 module_init(apm_init
);
2382 module_exit(apm_exit
);
2384 MODULE_AUTHOR("Stephen Rothwell");
2385 MODULE_DESCRIPTION("Advanced Power Management");
2386 MODULE_LICENSE("GPL");
2387 module_param(debug
, bool, 0644);
2388 MODULE_PARM_DESC(debug
, "Enable debug mode");
2389 module_param(power_off
, bool, 0444);
2390 MODULE_PARM_DESC(power_off
, "Enable power off");
2391 module_param(bounce_interval
, int, 0444);
2392 MODULE_PARM_DESC(bounce_interval
,
2393 "Set the number of ticks to ignore suspend bounces");
2394 module_param(allow_ints
, bool, 0444);
2395 MODULE_PARM_DESC(allow_ints
, "Allow interrupts during BIOS calls");
2396 module_param(broken_psr
, bool, 0444);
2397 MODULE_PARM_DESC(broken_psr
, "BIOS has a broken GetPowerStatus call");
2398 module_param(realmode_power_off
, bool, 0444);
2399 MODULE_PARM_DESC(realmode_power_off
,
2400 "Switch to real mode before powering off");
2401 module_param(idle_threshold
, int, 0444);
2402 MODULE_PARM_DESC(idle_threshold
,
2403 "System idle percentage above which to make APM BIOS idle calls");
2404 module_param(idle_period
, int, 0444);
2405 MODULE_PARM_DESC(idle_period
,
2406 "Period (in sec/100) over which to calculate the idle percentage");
2407 module_param(smp
, bool, 0444);
2408 MODULE_PARM_DESC(smp
,
2409 "Set this to enable APM use on an SMP platform. Use with caution on older systems");
2410 MODULE_ALIAS_MISCDEV(APM_MINOR_DEV
);