blob: 98c2cdeb599e71ecf2f26f177a8bc6f64cad4cc8 [file] [log] [blame]
Suresh Siddha61c46282008-03-10 15:28:04 -07001#include <linux/errno.h>
2#include <linux/kernel.h>
3#include <linux/mm.h>
4#include <linux/smp.h>
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -08005#include <linux/prctl.h>
Suresh Siddha61c46282008-03-10 15:28:04 -07006#include <linux/slab.h>
7#include <linux/sched.h>
Peter Zijlstra7f424a82008-04-25 17:39:01 +02008#include <linux/module.h>
9#include <linux/pm.h>
Thomas Gleixneraa276e12008-06-09 19:15:00 +020010#include <linux/clockchips.h>
Amerigo Wang9d62dcd2009-05-11 22:05:28 -040011#include <linux/random.h>
Avi Kivity7c68af62009-09-19 09:40:22 +030012#include <linux/user-return-notifier.h>
Andy Isaacson814e2c82009-12-08 00:29:42 -080013#include <linux/dmi.h>
14#include <linux/utsname.h>
Arjan van de Ven61613522009-09-17 16:11:28 +020015#include <trace/events/power.h>
Frederic Weisbecker24f1e32c2009-09-09 19:22:48 +020016#include <linux/hw_breakpoint.h>
Zhao Yakuic1e3b372008-06-24 17:58:53 +080017#include <asm/system.h>
Ivan Vecerad3ec5ca2008-11-11 14:33:44 +010018#include <asm/apic.h>
Jaswinder Singh Rajput2c1b2842009-04-11 00:03:10 +053019#include <asm/syscalls.h>
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -080020#include <asm/idle.h>
21#include <asm/uaccess.h>
22#include <asm/i387.h>
Markus Metzger2311f0d2009-04-03 16:43:46 +020023#include <asm/ds.h>
K.Prasad66cb5912009-06-01 23:44:55 +053024#include <asm/debugreg.h>
Zhao Yakuic1e3b372008-06-24 17:58:53 +080025
26unsigned long idle_halt;
27EXPORT_SYMBOL(idle_halt);
Zhao Yakuida5e09a2008-06-24 18:01:09 +080028unsigned long idle_nomwait;
29EXPORT_SYMBOL(idle_nomwait);
Suresh Siddha61c46282008-03-10 15:28:04 -070030
Suresh Siddhaaa283f42008-03-10 15:28:05 -070031struct kmem_cache *task_xstate_cachep;
Suresh Siddha61c46282008-03-10 15:28:04 -070032
33int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
34{
35 *dst = *src;
Suresh Siddhaaa283f42008-03-10 15:28:05 -070036 if (src->thread.xstate) {
37 dst->thread.xstate = kmem_cache_alloc(task_xstate_cachep,
38 GFP_KERNEL);
39 if (!dst->thread.xstate)
40 return -ENOMEM;
41 WARN_ON((unsigned long)dst->thread.xstate & 15);
42 memcpy(dst->thread.xstate, src->thread.xstate, xstate_size);
43 }
Suresh Siddha61c46282008-03-10 15:28:04 -070044 return 0;
45}
46
Suresh Siddhaaa283f42008-03-10 15:28:05 -070047void free_thread_xstate(struct task_struct *tsk)
48{
49 if (tsk->thread.xstate) {
50 kmem_cache_free(task_xstate_cachep, tsk->thread.xstate);
51 tsk->thread.xstate = NULL;
52 }
Markus Metzger2311f0d2009-04-03 16:43:46 +020053
54 WARN(tsk->thread.ds_ctx, "leaking DS context\n");
Suresh Siddhaaa283f42008-03-10 15:28:05 -070055}
56
Suresh Siddha61c46282008-03-10 15:28:04 -070057void free_thread_info(struct thread_info *ti)
58{
Suresh Siddhaaa283f42008-03-10 15:28:05 -070059 free_thread_xstate(ti->task);
Suresh Siddha1679f272008-04-16 10:27:53 +020060 free_pages((unsigned long)ti, get_order(THREAD_SIZE));
Suresh Siddha61c46282008-03-10 15:28:04 -070061}
62
63void arch_task_cache_init(void)
64{
65 task_xstate_cachep =
66 kmem_cache_create("task_xstate", xstate_size,
67 __alignof__(union thread_xstate),
Vegard Nossum2dff4402008-05-31 15:56:17 +020068 SLAB_PANIC | SLAB_NOTRACK, NULL);
Suresh Siddha61c46282008-03-10 15:28:04 -070069}
Peter Zijlstra7f424a82008-04-25 17:39:01 +020070
Thomas Gleixner00dba562008-06-09 18:35:28 +020071/*
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -080072 * Free current thread data structures etc..
73 */
74void exit_thread(void)
75{
76 struct task_struct *me = current;
77 struct thread_struct *t = &me->thread;
Thomas Gleixner250981e2009-03-16 13:07:21 +010078 unsigned long *bp = t->io_bitmap_ptr;
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -080079
Thomas Gleixner250981e2009-03-16 13:07:21 +010080 if (bp) {
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -080081 struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
82
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -080083 t->io_bitmap_ptr = NULL;
84 clear_thread_flag(TIF_IO_BITMAP);
85 /*
86 * Careful, clear this in the TSS too:
87 */
88 memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
89 t->io_bitmap_max = 0;
90 put_cpu();
Thomas Gleixner250981e2009-03-16 13:07:21 +010091 kfree(bp);
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -080092 }
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -080093}
94
Andy Isaacson814e2c82009-12-08 00:29:42 -080095void show_regs_common(void)
96{
Andy Isaacsona1884b82009-12-08 00:30:21 -080097 const char *board, *product;
Andy Isaacson814e2c82009-12-08 00:29:42 -080098
Andy Isaacsona1884b82009-12-08 00:30:21 -080099 board = dmi_get_system_info(DMI_BOARD_NAME);
Andy Isaacson814e2c82009-12-08 00:29:42 -0800100 if (!board)
101 board = "";
Andy Isaacsona1884b82009-12-08 00:30:21 -0800102 product = dmi_get_system_info(DMI_PRODUCT_NAME);
103 if (!product)
104 product = "";
Andy Isaacson814e2c82009-12-08 00:29:42 -0800105
106 printk("\n");
Andy Isaacsona1884b82009-12-08 00:30:21 -0800107 printk(KERN_INFO "Pid: %d, comm: %.20s %s %s %.*s %s/%s\n",
Andy Isaacson814e2c82009-12-08 00:29:42 -0800108 current->pid, current->comm, print_tainted(),
109 init_utsname()->release,
110 (int)strcspn(init_utsname()->version, " "),
Andy Isaacsona1884b82009-12-08 00:30:21 -0800111 init_utsname()->version, board, product);
Andy Isaacson814e2c82009-12-08 00:29:42 -0800112}
113
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -0800114void flush_thread(void)
115{
116 struct task_struct *tsk = current;
117
118#ifdef CONFIG_X86_64
119 if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) {
120 clear_tsk_thread_flag(tsk, TIF_ABI_PENDING);
121 if (test_tsk_thread_flag(tsk, TIF_IA32)) {
122 clear_tsk_thread_flag(tsk, TIF_IA32);
123 } else {
124 set_tsk_thread_flag(tsk, TIF_IA32);
125 current_thread_info()->status |= TS_COMPAT;
126 }
127 }
128#endif
129
Frederic Weisbecker24f1e32c2009-09-09 19:22:48 +0200130 flush_ptrace_hw_breakpoint(tsk);
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -0800131 memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
132 /*
133 * Forget coprocessor state..
134 */
135 tsk->fpu_counter = 0;
136 clear_fpu(tsk);
137 clear_used_math();
138}
139
140static void hard_disable_TSC(void)
141{
142 write_cr4(read_cr4() | X86_CR4_TSD);
143}
144
145void disable_TSC(void)
146{
147 preempt_disable();
148 if (!test_and_set_thread_flag(TIF_NOTSC))
149 /*
150 * Must flip the CPU state synchronously with
151 * TIF_NOTSC in the current running context.
152 */
153 hard_disable_TSC();
154 preempt_enable();
155}
156
157static void hard_enable_TSC(void)
158{
159 write_cr4(read_cr4() & ~X86_CR4_TSD);
160}
161
162static void enable_TSC(void)
163{
164 preempt_disable();
165 if (test_and_clear_thread_flag(TIF_NOTSC))
166 /*
167 * Must flip the CPU state synchronously with
168 * TIF_NOTSC in the current running context.
169 */
170 hard_enable_TSC();
171 preempt_enable();
172}
173
174int get_tsc_mode(unsigned long adr)
175{
176 unsigned int val;
177
178 if (test_thread_flag(TIF_NOTSC))
179 val = PR_TSC_SIGSEGV;
180 else
181 val = PR_TSC_ENABLE;
182
183 return put_user(val, (unsigned int __user *)adr);
184}
185
186int set_tsc_mode(unsigned int val)
187{
188 if (val == PR_TSC_SIGSEGV)
189 disable_TSC();
190 else if (val == PR_TSC_ENABLE)
191 enable_TSC();
192 else
193 return -EINVAL;
194
195 return 0;
196}
197
198void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
199 struct tss_struct *tss)
200{
201 struct thread_struct *prev, *next;
202
203 prev = &prev_p->thread;
204 next = &next_p->thread;
205
206 if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
207 test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
208 ds_switch_to(prev_p, next_p);
209 else if (next->debugctlmsr != prev->debugctlmsr)
210 update_debugctlmsr(next->debugctlmsr);
211
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -0800212 if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
213 test_tsk_thread_flag(next_p, TIF_NOTSC)) {
214 /* prev and next are different */
215 if (test_tsk_thread_flag(next_p, TIF_NOTSC))
216 hard_disable_TSC();
217 else
218 hard_enable_TSC();
219 }
220
221 if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
222 /*
223 * Copy the relevant range of the IO bitmap.
224 * Normally this is 128 bytes or less:
225 */
226 memcpy(tss->io_bitmap, next->io_bitmap_ptr,
227 max(prev->io_bitmap_max, next->io_bitmap_max));
228 } else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) {
229 /*
230 * Clear any possible leftover bits:
231 */
232 memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
233 }
Avi Kivity7c68af62009-09-19 09:40:22 +0300234 propagate_user_return_notify(prev_p, next_p);
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -0800235}
236
237int sys_fork(struct pt_regs *regs)
238{
239 return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
240}
241
242/*
243 * This is trivial, and on the face of it looks like it
244 * could equally well be done in user mode.
245 *
246 * Not so, for quite unobvious reasons - register pressure.
247 * In user mode vfork() cannot have a stack frame, and if
248 * done by calling the "clone()" system call directly, you
249 * do not have enough call-clobbered registers to hold all
250 * the information you need.
251 */
252int sys_vfork(struct pt_regs *regs)
253{
254 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0,
255 NULL, NULL);
256}
257
Brian Gerstf839bbc2009-12-09 19:01:56 -0500258long
259sys_clone(unsigned long clone_flags, unsigned long newsp,
260 void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
261{
262 if (!newsp)
263 newsp = regs->sp;
264 return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
265}
266
Brian Gerstdf59e7b2009-12-09 12:34:44 -0500267/*
268 * This gets run with %si containing the
269 * function to call, and %di containing
270 * the "args".
271 */
272extern void kernel_thread_helper(void);
273
274/*
275 * Create a kernel thread
276 */
277int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
278{
279 struct pt_regs regs;
280
281 memset(&regs, 0, sizeof(regs));
282
283 regs.si = (unsigned long) fn;
284 regs.di = (unsigned long) arg;
285
286#ifdef CONFIG_X86_32
287 regs.ds = __USER_DS;
288 regs.es = __USER_DS;
289 regs.fs = __KERNEL_PERCPU;
290 regs.gs = __KERNEL_STACK_CANARY;
291#endif
292
293 regs.orig_ax = -1;
294 regs.ip = (unsigned long) kernel_thread_helper;
295 regs.cs = __KERNEL_CS | get_kernel_rpl();
296 regs.flags = X86_EFLAGS_IF | 0x2;
297
298 /* Ok, create the new process.. */
299 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
300}
301EXPORT_SYMBOL(kernel_thread);
Jeremy Fitzhardinge389d1fb2009-02-27 13:25:28 -0800302
303/*
Brian Gerst11cf88b2009-12-09 19:01:53 -0500304 * sys_execve() executes a new program.
305 */
306long sys_execve(char __user *name, char __user * __user *argv,
307 char __user * __user *envp, struct pt_regs *regs)
308{
309 long error;
310 char *filename;
311
312 filename = getname(name);
313 error = PTR_ERR(filename);
314 if (IS_ERR(filename))
315 return error;
316 error = do_execve(filename, argv, envp, regs);
317
318#ifdef CONFIG_X86_32
319 if (error == 0) {
320 /* Make sure we don't return using sysenter.. */
321 set_thread_flag(TIF_IRET);
322 }
323#endif
324
325 putname(filename);
326 return error;
327}
Thomas Gleixner09fd4b42008-06-09 18:04:27 +0200328
329/*
Thomas Gleixnere9623b32008-05-16 22:55:26 +0200330 * Idle related variables and functions
331 */
Thomas Gleixner09fd4b42008-06-09 18:04:27 +0200332unsigned long boot_option_idle_override = 0;
333EXPORT_SYMBOL(boot_option_idle_override);
Thomas Gleixnere9623b32008-05-16 22:55:26 +0200334
335/*
336 * Powermanagement idle function, if any..
Thomas Gleixner09fd4b42008-06-09 18:04:27 +0200337 */
338void (*pm_idle)(void);
339EXPORT_SYMBOL(pm_idle);
340
341#ifdef CONFIG_X86_32
342/*
343 * This halt magic was a workaround for ancient floppy DMA
344 * wreckage. It should be safe to remove.
345 */
346static int hlt_counter;
347void disable_hlt(void)
348{
349 hlt_counter++;
Thomas Gleixnere9623b32008-05-16 22:55:26 +0200350}
351EXPORT_SYMBOL(disable_hlt);
Thomas Gleixneraa276e12008-06-09 19:15:00 +0200352
353void enable_hlt(void)
354{
355 hlt_counter--;
356}
357EXPORT_SYMBOL(enable_hlt);
358
359static inline int hlt_use_halt(void)
360{
361 return (!hlt_counter && boot_cpu_data.hlt_works_ok);
362}
363#else
364static inline int hlt_use_halt(void)
365{
366 return 1;
367}
368#endif
369
Thomas Gleixner4faac972008-09-22 18:54:29 +0200370/*
371 * We use this if we don't have any better
372 * idle routine..
373 */
374void default_idle(void)
375{
376 if (hlt_use_halt()) {
Arjan van de Ven61613522009-09-17 16:11:28 +0200377 trace_power_start(POWER_CSTATE, 1);
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200378 current_thread_info()->status &= ~TS_POLLING;
379 /*
380 * TS_POLLING-cleared state must be visible before we
381 * test NEED_RESCHED:
382 */
383 smp_mb();
384
385 if (!need_resched())
386 safe_halt(); /* enables interrupts racelessly */
387 else
388 local_irq_enable();
389 current_thread_info()->status |= TS_POLLING;
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200390 } else {
391 local_irq_enable();
392 /* loop is done by the caller */
393 cpu_relax();
394 }
395}
396#ifdef CONFIG_APM_MODULE
397EXPORT_SYMBOL(default_idle);
398#endif
399
400void stop_this_cpu(void *dummy)
401{
402 local_irq_disable();
403 /*
404 * Remove this CPU:
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200405 */
Rusty Russell4f062892009-03-13 14:49:54 +1030406 set_cpu_online(smp_processor_id(), false);
Suresh Siddha61c46282008-03-10 15:28:04 -0700407 disable_local_APIC();
408
409 for (;;) {
410 if (hlt_works(smp_processor_id()))
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200411 halt();
412 }
413}
414
415static void do_nothing(void *unused)
416{
417}
418
419/*
420 * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
421 * pm_idle and update to new pm_idle value. Required while changing pm_idle
422 * handler on SMP systems.
423 *
424 * Caller must have changed pm_idle to the new value before the call. Old
425 * pm_idle value will not be used by any CPU after the return of this function.
426 */
427void cpu_idle_wait(void)
428{
429 smp_mb();
430 /* kick all the CPUs so that they exit out of pm_idle */
431 smp_call_function(do_nothing, NULL, 1);
432}
433EXPORT_SYMBOL_GPL(cpu_idle_wait);
434
435/*
436 * This uses new MONITOR/MWAIT instructions on P4 processors with PNI,
437 * which can obviate IPI to trigger checking of need_resched.
438 * We execute MONITOR against need_resched and enter optimized wait state
439 * through MWAIT. Whenever someone changes need_resched, we would be woken
440 * up from MWAIT (without an IPI).
441 *
442 * New with Core Duo processors, MWAIT can take some hints based on CPU
443 * capability.
444 */
445void mwait_idle_with_hints(unsigned long ax, unsigned long cx)
446{
Arjan van de Ven61613522009-09-17 16:11:28 +0200447 trace_power_start(POWER_CSTATE, (ax>>4)+1);
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200448 if (!need_resched()) {
449 if (cpu_has(&current_cpu_data, X86_FEATURE_CLFLUSH_MONITOR))
450 clflush((void *)&current_thread_info()->flags);
451
452 __monitor((void *)&current_thread_info()->flags, 0, 0);
453 smp_mb();
454 if (!need_resched())
455 __mwait(ax, cx);
456 }
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200457}
458
459/* Default MONITOR/MWAIT with no hints, used for default C1 state */
460static void mwait_idle(void)
461{
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200462 if (!need_resched()) {
Arjan van de Ven61613522009-09-17 16:11:28 +0200463 trace_power_start(POWER_CSTATE, 1);
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200464 if (cpu_has(&current_cpu_data, X86_FEATURE_CLFLUSH_MONITOR))
465 clflush((void *)&current_thread_info()->flags);
466
467 __monitor((void *)&current_thread_info()->flags, 0, 0);
468 smp_mb();
469 if (!need_resched())
470 __sti_mwait(0, 0);
471 else
472 local_irq_enable();
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200473 } else
474 local_irq_enable();
475}
476
477/*
478 * On SMP it's slightly faster (but much more power-consuming!)
479 * to poll the ->work.need_resched flag instead of waiting for the
480 * cross-CPU IPI to arrive. Use this option with caution.
481 */
482static void poll_idle(void)
483{
Arjan van de Ven61613522009-09-17 16:11:28 +0200484 trace_power_start(POWER_CSTATE, 0);
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200485 local_irq_enable();
486 while (!need_resched())
487 cpu_relax();
Arjan van de Ven61613522009-09-17 16:11:28 +0200488 trace_power_end(0);
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200489}
490
491/*
492 * mwait selection logic:
493 *
494 * It depends on the CPU. For AMD CPUs that support MWAIT this is
495 * wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings
496 * then depend on a clock divisor and current Pstate of the core. If
497 * all cores of a processor are in halt state (C1) the processor can
498 * enter the C1E (C1 enhanced) state. If mwait is used this will never
499 * happen.
500 *
501 * idle=mwait overrides this decision and forces the usage of mwait.
502 */
503static int __cpuinitdata force_mwait;
504
505#define MWAIT_INFO 0x05
506#define MWAIT_ECX_EXTENDED_INFO 0x01
507#define MWAIT_EDX_C1 0xf0
508
509static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c)
510{
511 u32 eax, ebx, ecx, edx;
512
513 if (force_mwait)
514 return 1;
515
516 if (c->cpuid_level < MWAIT_INFO)
517 return 0;
518
519 cpuid(MWAIT_INFO, &eax, &ebx, &ecx, &edx);
520 /* Check, whether EDX has extended info about MWAIT */
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200521 if (!(ecx & MWAIT_ECX_EXTENDED_INFO))
522 return 1;
523
524 /*
525 * edx enumeratios MONITOR/MWAIT extensions. Check, whether
526 * C1 supports MWAIT
Thomas Gleixner6ddd2a22008-06-09 16:59:53 +0200527 */
528 return (edx & MWAIT_EDX_C1);
529}
Thomas Gleixnere9623b32008-05-16 22:55:26 +0200530
Thomas Gleixneraa276e12008-06-09 19:15:00 +0200531/*
532 * Check for AMD CPUs, which have potentially C1E support
533 */
534static int __cpuinit check_c1e_idle(const struct cpuinfo_x86 *c)
535{
536 if (c->x86_vendor != X86_VENDOR_AMD)
537 return 0;
538
539 if (c->x86 < 0x0F)
540 return 0;
541
542 /* Family 0x0f models < rev F do not have C1E */
543 if (c->x86 == 0x0f && c->x86_model < 0x40)
544 return 0;
545
546 return 1;
547}
548
Rusty Russellbc9b83d2009-03-13 14:49:49 +1030549static cpumask_var_t c1e_mask;
Thomas Gleixner4faac972008-09-22 18:54:29 +0200550static int c1e_detected;
551
552void c1e_remove_cpu(int cpu)
553{
Rusty Russell30e1e6d2009-03-17 14:50:34 +1030554 if (c1e_mask != NULL)
555 cpumask_clear_cpu(cpu, c1e_mask);
Thomas Gleixner4faac972008-09-22 18:54:29 +0200556}
557
Thomas Gleixneraa276e12008-06-09 19:15:00 +0200558/*
559 * C1E aware idle routine. We check for C1E active in the interrupt
560 * pending message MSR. If we detect C1E, then we handle it the same
561 * way as C3 power states (local apic timer and TSC stop)
562 */
563static void c1e_idle(void)
564{
Thomas Gleixneraa276e12008-06-09 19:15:00 +0200565 if (need_resched())
566 return;
567
568 if (!c1e_detected) {
569 u32 lo, hi;
570
571 rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
572 if (lo & K8_INTP_C1E_ACTIVE_MASK) {
573 c1e_detected = 1;
Venki Pallipadi40fb1712008-11-17 16:11:37 -0800574 if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
Andreas Herrmann09bfeea2008-09-18 21:12:10 +0200575 mark_tsc_unstable("TSC halt in AMD C1E");
576 printk(KERN_INFO "System has AMD C1E enabled\n");
Thomas Gleixnera8d68292008-09-22 19:02:25 +0200577 set_cpu_cap(&boot_cpu_data, X86_FEATURE_AMDC1E);
Thomas Gleixneraa276e12008-06-09 19:15:00 +0200578 }
579 }
580
581 if (c1e_detected) {
582 int cpu = smp_processor_id();
583
Rusty Russellbc9b83d2009-03-13 14:49:49 +1030584 if (!cpumask_test_cpu(cpu, c1e_mask)) {
585 cpumask_set_cpu(cpu, c1e_mask);
Thomas Gleixner0beefa22008-06-17 09:12:03 +0200586 /*
Suresh Siddhaf833bab2009-08-17 14:34:59 -0700587 * Force broadcast so ACPI can not interfere.
Thomas Gleixner0beefa22008-06-17 09:12:03 +0200588 */
Thomas Gleixneraa276e12008-06-09 19:15:00 +0200589 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_FORCE,
590 &cpu);
591 printk(KERN_INFO "Switch to broadcast mode on CPU%d\n",
592 cpu);
593 }
594 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
Thomas Gleixner0beefa22008-06-17 09:12:03 +0200595
Thomas Gleixneraa276e12008-06-09 19:15:00 +0200596 default_idle();
Thomas Gleixner0beefa22008-06-17 09:12:03 +0200597
598 /*
599 * The switch back from broadcast mode needs to be
600 * called with interrupts disabled.
601 */
602 local_irq_disable();
603 clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
604 local_irq_enable();
Thomas Gleixneraa276e12008-06-09 19:15:00 +0200605 } else
606 default_idle();
607}
608
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200609void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
610{
Ingo Molnar3e5095d2009-01-27 17:07:08 +0100611#ifdef CONFIG_SMP
Peter Zijlstra7f424a82008-04-25 17:39:01 +0200612 if (pm_idle == poll_idle && smp_num_siblings > 1) {
613 printk(KERN_WARNING "WARNING: polling idle and HT enabled,"
614 " performance may degrade.\n");
615 }
616#endif
617 if (pm_idle)
618 return;
619
620 if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
Suresh Siddha61c46282008-03-10 15:28:04 -0700621 /*
Suresh Siddha61c46282008-03-10 15:28:04 -0700622 * One CPU supports mwait => All CPUs supports mwait
623 */
Thomas Gleixner6ddd2a22008-06-09 16:59:53 +0200624 printk(KERN_INFO "using mwait in idle threads.\n");
625 pm_idle = mwait_idle;
Thomas Gleixneraa276e12008-06-09 19:15:00 +0200626 } else if (check_c1e_idle(c)) {
627 printk(KERN_INFO "using C1E aware idle routine\n");
628 pm_idle = c1e_idle;
Thomas Gleixner6ddd2a22008-06-09 16:59:53 +0200629 } else
630 pm_idle = default_idle;
Suresh Siddha61c46282008-03-10 15:28:04 -0700631}
632
Rusty Russell30e1e6d2009-03-17 14:50:34 +1030633void __init init_c1e_mask(void)
634{
635 /* If we're using c1e_idle, we need to allocate c1e_mask. */
Li Zefan79f55992009-06-15 14:58:26 +0800636 if (pm_idle == c1e_idle)
637 zalloc_cpumask_var(&c1e_mask, GFP_KERNEL);
Rusty Russell30e1e6d2009-03-17 14:50:34 +1030638}
639
Suresh Siddha61c46282008-03-10 15:28:04 -0700640static int __init idle_setup(char *str)
641{
Cyrill Gorcunovab6bc3e2008-07-05 15:53:36 +0400642 if (!str)
643 return -EINVAL;
644
Suresh Siddha61c46282008-03-10 15:28:04 -0700645 if (!strcmp(str, "poll")) {
646 printk("using polling idle threads.\n");
647 pm_idle = poll_idle;
648 } else if (!strcmp(str, "mwait"))
649 force_mwait = 1;
Zhao Yakuic1e3b372008-06-24 17:58:53 +0800650 else if (!strcmp(str, "halt")) {
651 /*
652 * When the boot option of idle=halt is added, halt is
653 * forced to be used for CPU idle. In such case CPU C2/C3
654 * won't be used again.
655 * To continue to load the CPU idle driver, don't touch
656 * the boot_option_idle_override.
657 */
658 pm_idle = default_idle;
659 idle_halt = 1;
660 return 0;
Zhao Yakuida5e09a2008-06-24 18:01:09 +0800661 } else if (!strcmp(str, "nomwait")) {
662 /*
663 * If the boot option of "idle=nomwait" is added,
664 * it means that mwait will be disabled for CPU C2/C3
665 * states. In such case it won't touch the variable
666 * of boot_option_idle_override.
667 */
668 idle_nomwait = 1;
669 return 0;
Zhao Yakuic1e3b372008-06-24 17:58:53 +0800670 } else
Suresh Siddha61c46282008-03-10 15:28:04 -0700671 return -1;
672
673 boot_option_idle_override = 1;
674 return 0;
675}
676early_param("idle", idle_setup);
677
Amerigo Wang9d62dcd2009-05-11 22:05:28 -0400678unsigned long arch_align_stack(unsigned long sp)
679{
680 if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
681 sp -= get_random_int() % 8192;
682 return sp & ~0xf;
683}
684
685unsigned long arch_randomize_brk(struct mm_struct *mm)
686{
687 unsigned long range_end = mm->brk + 0x02000000;
688 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
689}
690