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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
c767a54b JP |
2 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
3 | ||
61c4628b SS |
4 | #include <linux/errno.h> |
5 | #include <linux/kernel.h> | |
6 | #include <linux/mm.h> | |
7 | #include <linux/smp.h> | |
389d1fb1 | 8 | #include <linux/prctl.h> |
61c4628b SS |
9 | #include <linux/slab.h> |
10 | #include <linux/sched.h> | |
4c822698 | 11 | #include <linux/sched/idle.h> |
b17b0153 | 12 | #include <linux/sched/debug.h> |
29930025 | 13 | #include <linux/sched/task.h> |
68db0cf1 | 14 | #include <linux/sched/task_stack.h> |
186f4360 PG |
15 | #include <linux/init.h> |
16 | #include <linux/export.h> | |
7f424a8b | 17 | #include <linux/pm.h> |
162a688e | 18 | #include <linux/tick.h> |
9d62dcdf | 19 | #include <linux/random.h> |
7c68af6e | 20 | #include <linux/user-return-notifier.h> |
814e2c84 AI |
21 | #include <linux/dmi.h> |
22 | #include <linux/utsname.h> | |
90e24014 RW |
23 | #include <linux/stackprotector.h> |
24 | #include <linux/tick.h> | |
25 | #include <linux/cpuidle.h> | |
61613521 | 26 | #include <trace/events/power.h> |
24f1e32c | 27 | #include <linux/hw_breakpoint.h> |
93789b32 | 28 | #include <asm/cpu.h> |
d3ec5cae | 29 | #include <asm/apic.h> |
2c1b284e | 30 | #include <asm/syscalls.h> |
7c0f6ba6 | 31 | #include <linux/uaccess.h> |
b253149b | 32 | #include <asm/mwait.h> |
78f7f1e5 | 33 | #include <asm/fpu/internal.h> |
66cb5917 | 34 | #include <asm/debugreg.h> |
90e24014 | 35 | #include <asm/nmi.h> |
375074cc | 36 | #include <asm/tlbflush.h> |
8838eb6c | 37 | #include <asm/mce.h> |
9fda6a06 | 38 | #include <asm/vm86.h> |
7b32aead | 39 | #include <asm/switch_to.h> |
b7ffc44d | 40 | #include <asm/desc.h> |
e9ea1e7f | 41 | #include <asm/prctl.h> |
90e24014 | 42 | |
45046892 TG |
43 | /* |
44 | * per-CPU TSS segments. Threads are completely 'soft' on Linux, | |
45 | * no more per-task TSS's. The TSS size is kept cacheline-aligned | |
46 | * so they are allowed to end up in the .data..cacheline_aligned | |
47 | * section. Since TSS's are completely CPU-local, we want them | |
48 | * on exact cacheline boundaries, to eliminate cacheline ping-pong. | |
49 | */ | |
d0a0de21 AL |
50 | __visible DEFINE_PER_CPU_SHARED_ALIGNED(struct tss_struct, cpu_tss) = { |
51 | .x86_tss = { | |
d9e05cc5 | 52 | .sp0 = TOP_OF_INIT_STACK, |
d0a0de21 AL |
53 | #ifdef CONFIG_X86_32 |
54 | .ss0 = __KERNEL_DS, | |
55 | .ss1 = __KERNEL_CS, | |
56 | .io_bitmap_base = INVALID_IO_BITMAP_OFFSET, | |
57 | #endif | |
58 | }, | |
59 | #ifdef CONFIG_X86_32 | |
60 | /* | |
61 | * Note that the .io_bitmap member must be extra-big. This is because | |
62 | * the CPU will access an additional byte beyond the end of the IO | |
63 | * permission bitmap. The extra byte must be all 1 bits, and must | |
64 | * be within the limit. | |
65 | */ | |
66 | .io_bitmap = { [0 ... IO_BITMAP_LONGS] = ~0 }, | |
67 | #endif | |
2a41aa4f AL |
68 | #ifdef CONFIG_X86_32 |
69 | .SYSENTER_stack_canary = STACK_END_MAGIC, | |
70 | #endif | |
d0a0de21 | 71 | }; |
de71ad2c | 72 | EXPORT_PER_CPU_SYMBOL(cpu_tss); |
45046892 | 73 | |
b7ceaec1 AL |
74 | DEFINE_PER_CPU(bool, __tss_limit_invalid); |
75 | EXPORT_PER_CPU_SYMBOL_GPL(__tss_limit_invalid); | |
b7ffc44d | 76 | |
55ccf3fe SS |
77 | /* |
78 | * this gets called so that we can store lazy state into memory and copy the | |
79 | * current task into the new thread. | |
80 | */ | |
61c4628b SS |
81 | int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src) |
82 | { | |
5aaeb5c0 | 83 | memcpy(dst, src, arch_task_struct_size); |
2459ee86 AL |
84 | #ifdef CONFIG_VM86 |
85 | dst->thread.vm86 = NULL; | |
86 | #endif | |
f1853505 | 87 | |
c69e098b | 88 | return fpu__copy(&dst->thread.fpu, &src->thread.fpu); |
61c4628b | 89 | } |
7f424a8b | 90 | |
389d1fb1 JF |
91 | /* |
92 | * Free current thread data structures etc.. | |
93 | */ | |
e6464694 | 94 | void exit_thread(struct task_struct *tsk) |
389d1fb1 | 95 | { |
e6464694 | 96 | struct thread_struct *t = &tsk->thread; |
250981e6 | 97 | unsigned long *bp = t->io_bitmap_ptr; |
ca6787ba | 98 | struct fpu *fpu = &t->fpu; |
389d1fb1 | 99 | |
250981e6 | 100 | if (bp) { |
24933b82 | 101 | struct tss_struct *tss = &per_cpu(cpu_tss, get_cpu()); |
389d1fb1 | 102 | |
389d1fb1 JF |
103 | t->io_bitmap_ptr = NULL; |
104 | clear_thread_flag(TIF_IO_BITMAP); | |
105 | /* | |
106 | * Careful, clear this in the TSS too: | |
107 | */ | |
108 | memset(tss->io_bitmap, 0xff, t->io_bitmap_max); | |
109 | t->io_bitmap_max = 0; | |
110 | put_cpu(); | |
250981e6 | 111 | kfree(bp); |
389d1fb1 | 112 | } |
1dcc8d7b | 113 | |
9fda6a06 BG |
114 | free_vm86(t); |
115 | ||
50338615 | 116 | fpu__drop(fpu); |
389d1fb1 JF |
117 | } |
118 | ||
119 | void flush_thread(void) | |
120 | { | |
121 | struct task_struct *tsk = current; | |
122 | ||
24f1e32c | 123 | flush_ptrace_hw_breakpoint(tsk); |
389d1fb1 | 124 | memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array)); |
110d7f75 | 125 | |
04c8e01d | 126 | fpu__clear(&tsk->thread.fpu); |
389d1fb1 JF |
127 | } |
128 | ||
389d1fb1 JF |
129 | void disable_TSC(void) |
130 | { | |
131 | preempt_disable(); | |
132 | if (!test_and_set_thread_flag(TIF_NOTSC)) | |
133 | /* | |
134 | * Must flip the CPU state synchronously with | |
135 | * TIF_NOTSC in the current running context. | |
136 | */ | |
5a920155 | 137 | cr4_set_bits(X86_CR4_TSD); |
389d1fb1 JF |
138 | preempt_enable(); |
139 | } | |
140 | ||
389d1fb1 JF |
141 | static void enable_TSC(void) |
142 | { | |
143 | preempt_disable(); | |
144 | if (test_and_clear_thread_flag(TIF_NOTSC)) | |
145 | /* | |
146 | * Must flip the CPU state synchronously with | |
147 | * TIF_NOTSC in the current running context. | |
148 | */ | |
5a920155 | 149 | cr4_clear_bits(X86_CR4_TSD); |
389d1fb1 JF |
150 | preempt_enable(); |
151 | } | |
152 | ||
153 | int get_tsc_mode(unsigned long adr) | |
154 | { | |
155 | unsigned int val; | |
156 | ||
157 | if (test_thread_flag(TIF_NOTSC)) | |
158 | val = PR_TSC_SIGSEGV; | |
159 | else | |
160 | val = PR_TSC_ENABLE; | |
161 | ||
162 | return put_user(val, (unsigned int __user *)adr); | |
163 | } | |
164 | ||
165 | int set_tsc_mode(unsigned int val) | |
166 | { | |
167 | if (val == PR_TSC_SIGSEGV) | |
168 | disable_TSC(); | |
169 | else if (val == PR_TSC_ENABLE) | |
170 | enable_TSC(); | |
171 | else | |
172 | return -EINVAL; | |
173 | ||
174 | return 0; | |
175 | } | |
176 | ||
e9ea1e7f KH |
177 | DEFINE_PER_CPU(u64, msr_misc_features_shadow); |
178 | ||
179 | static void set_cpuid_faulting(bool on) | |
180 | { | |
181 | u64 msrval; | |
182 | ||
183 | msrval = this_cpu_read(msr_misc_features_shadow); | |
184 | msrval &= ~MSR_MISC_FEATURES_ENABLES_CPUID_FAULT; | |
185 | msrval |= (on << MSR_MISC_FEATURES_ENABLES_CPUID_FAULT_BIT); | |
186 | this_cpu_write(msr_misc_features_shadow, msrval); | |
187 | wrmsrl(MSR_MISC_FEATURES_ENABLES, msrval); | |
188 | } | |
189 | ||
190 | static void disable_cpuid(void) | |
191 | { | |
192 | preempt_disable(); | |
193 | if (!test_and_set_thread_flag(TIF_NOCPUID)) { | |
194 | /* | |
195 | * Must flip the CPU state synchronously with | |
196 | * TIF_NOCPUID in the current running context. | |
197 | */ | |
198 | set_cpuid_faulting(true); | |
199 | } | |
200 | preempt_enable(); | |
201 | } | |
202 | ||
203 | static void enable_cpuid(void) | |
204 | { | |
205 | preempt_disable(); | |
206 | if (test_and_clear_thread_flag(TIF_NOCPUID)) { | |
207 | /* | |
208 | * Must flip the CPU state synchronously with | |
209 | * TIF_NOCPUID in the current running context. | |
210 | */ | |
211 | set_cpuid_faulting(false); | |
212 | } | |
213 | preempt_enable(); | |
214 | } | |
215 | ||
216 | static int get_cpuid_mode(void) | |
217 | { | |
218 | return !test_thread_flag(TIF_NOCPUID); | |
219 | } | |
220 | ||
221 | static int set_cpuid_mode(struct task_struct *task, unsigned long cpuid_enabled) | |
222 | { | |
223 | if (!static_cpu_has(X86_FEATURE_CPUID_FAULT)) | |
224 | return -ENODEV; | |
225 | ||
226 | if (cpuid_enabled) | |
227 | enable_cpuid(); | |
228 | else | |
229 | disable_cpuid(); | |
230 | ||
231 | return 0; | |
232 | } | |
233 | ||
234 | /* | |
235 | * Called immediately after a successful exec. | |
236 | */ | |
237 | void arch_setup_new_exec(void) | |
238 | { | |
239 | /* If cpuid was previously disabled for this task, re-enable it. */ | |
240 | if (test_thread_flag(TIF_NOCPUID)) | |
241 | enable_cpuid(); | |
242 | } | |
243 | ||
af8b3cd3 KH |
244 | static inline void switch_to_bitmap(struct tss_struct *tss, |
245 | struct thread_struct *prev, | |
246 | struct thread_struct *next, | |
247 | unsigned long tifp, unsigned long tifn) | |
248 | { | |
249 | if (tifn & _TIF_IO_BITMAP) { | |
250 | /* | |
251 | * Copy the relevant range of the IO bitmap. | |
252 | * Normally this is 128 bytes or less: | |
253 | */ | |
254 | memcpy(tss->io_bitmap, next->io_bitmap_ptr, | |
255 | max(prev->io_bitmap_max, next->io_bitmap_max)); | |
256 | /* | |
257 | * Make sure that the TSS limit is correct for the CPU | |
258 | * to notice the IO bitmap. | |
259 | */ | |
260 | refresh_tss_limit(); | |
261 | } else if (tifp & _TIF_IO_BITMAP) { | |
262 | /* | |
263 | * Clear any possible leftover bits: | |
264 | */ | |
265 | memset(tss->io_bitmap, 0xff, prev->io_bitmap_max); | |
266 | } | |
267 | } | |
268 | ||
389d1fb1 JF |
269 | void __switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p, |
270 | struct tss_struct *tss) | |
271 | { | |
272 | struct thread_struct *prev, *next; | |
af8b3cd3 | 273 | unsigned long tifp, tifn; |
389d1fb1 JF |
274 | |
275 | prev = &prev_p->thread; | |
276 | next = &next_p->thread; | |
277 | ||
af8b3cd3 KH |
278 | tifn = READ_ONCE(task_thread_info(next_p)->flags); |
279 | tifp = READ_ONCE(task_thread_info(prev_p)->flags); | |
280 | switch_to_bitmap(tss, prev, next, tifp, tifn); | |
281 | ||
282 | propagate_user_return_notify(prev_p, next_p); | |
283 | ||
b9894a2f KH |
284 | if ((tifp & _TIF_BLOCKSTEP || tifn & _TIF_BLOCKSTEP) && |
285 | arch_has_block_step()) { | |
286 | unsigned long debugctl, msk; | |
ea8e61b7 | 287 | |
b9894a2f | 288 | rdmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); |
ea8e61b7 | 289 | debugctl &= ~DEBUGCTLMSR_BTF; |
b9894a2f KH |
290 | msk = tifn & _TIF_BLOCKSTEP; |
291 | debugctl |= (msk >> TIF_BLOCKSTEP) << DEBUGCTLMSR_BTF_SHIFT; | |
292 | wrmsrl(MSR_IA32_DEBUGCTLMSR, debugctl); | |
ea8e61b7 | 293 | } |
389d1fb1 | 294 | |
5a920155 TG |
295 | if ((tifp ^ tifn) & _TIF_NOTSC) |
296 | cr4_toggle_bits(X86_CR4_TSD); | |
e9ea1e7f KH |
297 | |
298 | if ((tifp ^ tifn) & _TIF_NOCPUID) | |
299 | set_cpuid_faulting(!!(tifn & _TIF_NOCPUID)); | |
389d1fb1 JF |
300 | } |
301 | ||
00dba564 TG |
302 | /* |
303 | * Idle related variables and functions | |
304 | */ | |
d1896049 | 305 | unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE; |
00dba564 TG |
306 | EXPORT_SYMBOL(boot_option_idle_override); |
307 | ||
a476bda3 | 308 | static void (*x86_idle)(void); |
00dba564 | 309 | |
90e24014 RW |
310 | #ifndef CONFIG_SMP |
311 | static inline void play_dead(void) | |
312 | { | |
313 | BUG(); | |
314 | } | |
315 | #endif | |
316 | ||
7d1a9417 TG |
317 | void arch_cpu_idle_enter(void) |
318 | { | |
6a369583 | 319 | tsc_verify_tsc_adjust(false); |
7d1a9417 | 320 | local_touch_nmi(); |
7d1a9417 | 321 | } |
90e24014 | 322 | |
7d1a9417 TG |
323 | void arch_cpu_idle_dead(void) |
324 | { | |
325 | play_dead(); | |
326 | } | |
90e24014 | 327 | |
7d1a9417 TG |
328 | /* |
329 | * Called from the generic idle code. | |
330 | */ | |
331 | void arch_cpu_idle(void) | |
332 | { | |
16f8b05a | 333 | x86_idle(); |
90e24014 RW |
334 | } |
335 | ||
00dba564 | 336 | /* |
7d1a9417 | 337 | * We use this if we don't have any better idle routine.. |
00dba564 | 338 | */ |
6727ad9e | 339 | void __cpuidle default_idle(void) |
00dba564 | 340 | { |
4d0e42cc | 341 | trace_cpu_idle_rcuidle(1, smp_processor_id()); |
7d1a9417 | 342 | safe_halt(); |
4d0e42cc | 343 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); |
00dba564 | 344 | } |
60b8b1de | 345 | #ifdef CONFIG_APM_MODULE |
00dba564 TG |
346 | EXPORT_SYMBOL(default_idle); |
347 | #endif | |
348 | ||
6a377ddc LB |
349 | #ifdef CONFIG_XEN |
350 | bool xen_set_default_idle(void) | |
e5fd47bf | 351 | { |
a476bda3 | 352 | bool ret = !!x86_idle; |
e5fd47bf | 353 | |
a476bda3 | 354 | x86_idle = default_idle; |
e5fd47bf KRW |
355 | |
356 | return ret; | |
357 | } | |
6a377ddc | 358 | #endif |
bba4ed01 | 359 | |
d3ec5cae IV |
360 | void stop_this_cpu(void *dummy) |
361 | { | |
362 | local_irq_disable(); | |
363 | /* | |
364 | * Remove this CPU: | |
365 | */ | |
4f062896 | 366 | set_cpu_online(smp_processor_id(), false); |
d3ec5cae | 367 | disable_local_APIC(); |
8838eb6c | 368 | mcheck_cpu_clear(this_cpu_ptr(&cpu_info)); |
d3ec5cae | 369 | |
bba4ed01 TL |
370 | for (;;) { |
371 | /* | |
372 | * Use wbinvd followed by hlt to stop the processor. This | |
373 | * provides support for kexec on a processor that supports | |
374 | * SME. With kexec, going from SME inactive to SME active | |
375 | * requires clearing cache entries so that addresses without | |
376 | * the encryption bit set don't corrupt the same physical | |
377 | * address that has the encryption bit set when caches are | |
378 | * flushed. To achieve this a wbinvd is performed followed by | |
379 | * a hlt. Even if the processor is not in the kexec/SME | |
380 | * scenario this only adds a wbinvd to a halting processor. | |
381 | */ | |
382 | asm volatile("wbinvd; hlt" : : : "memory"); | |
383 | } | |
7f424a8b PZ |
384 | } |
385 | ||
aa276e1c | 386 | /* |
07c94a38 BP |
387 | * AMD Erratum 400 aware idle routine. We handle it the same way as C3 power |
388 | * states (local apic timer and TSC stop). | |
aa276e1c | 389 | */ |
02c68a02 | 390 | static void amd_e400_idle(void) |
aa276e1c | 391 | { |
07c94a38 BP |
392 | /* |
393 | * We cannot use static_cpu_has_bug() here because X86_BUG_AMD_APIC_C1E | |
394 | * gets set after static_cpu_has() places have been converted via | |
395 | * alternatives. | |
396 | */ | |
397 | if (!boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) { | |
398 | default_idle(); | |
399 | return; | |
aa276e1c TG |
400 | } |
401 | ||
07c94a38 | 402 | tick_broadcast_enter(); |
aa276e1c | 403 | |
07c94a38 | 404 | default_idle(); |
0beefa20 | 405 | |
07c94a38 BP |
406 | /* |
407 | * The switch back from broadcast mode needs to be called with | |
408 | * interrupts disabled. | |
409 | */ | |
410 | local_irq_disable(); | |
411 | tick_broadcast_exit(); | |
412 | local_irq_enable(); | |
aa276e1c TG |
413 | } |
414 | ||
b253149b LB |
415 | /* |
416 | * Intel Core2 and older machines prefer MWAIT over HALT for C1. | |
417 | * We can't rely on cpuidle installing MWAIT, because it will not load | |
418 | * on systems that support only C1 -- so the boot default must be MWAIT. | |
419 | * | |
420 | * Some AMD machines are the opposite, they depend on using HALT. | |
421 | * | |
422 | * So for default C1, which is used during boot until cpuidle loads, | |
423 | * use MWAIT-C1 on Intel HW that has it, else use HALT. | |
424 | */ | |
425 | static int prefer_mwait_c1_over_halt(const struct cpuinfo_x86 *c) | |
426 | { | |
427 | if (c->x86_vendor != X86_VENDOR_INTEL) | |
428 | return 0; | |
429 | ||
08e237fa | 430 | if (!cpu_has(c, X86_FEATURE_MWAIT) || static_cpu_has_bug(X86_BUG_MONITOR)) |
b253149b LB |
431 | return 0; |
432 | ||
433 | return 1; | |
434 | } | |
435 | ||
436 | /* | |
0fb0328d HR |
437 | * MONITOR/MWAIT with no hints, used for default C1 state. This invokes MWAIT |
438 | * with interrupts enabled and no flags, which is backwards compatible with the | |
439 | * original MWAIT implementation. | |
b253149b | 440 | */ |
6727ad9e | 441 | static __cpuidle void mwait_idle(void) |
b253149b | 442 | { |
f8e617f4 | 443 | if (!current_set_polling_and_test()) { |
e43d0189 | 444 | trace_cpu_idle_rcuidle(1, smp_processor_id()); |
f8e617f4 | 445 | if (this_cpu_has(X86_BUG_CLFLUSH_MONITOR)) { |
ca59809f | 446 | mb(); /* quirk */ |
b253149b | 447 | clflush((void *)¤t_thread_info()->flags); |
ca59809f | 448 | mb(); /* quirk */ |
f8e617f4 | 449 | } |
b253149b LB |
450 | |
451 | __monitor((void *)¤t_thread_info()->flags, 0, 0); | |
b253149b LB |
452 | if (!need_resched()) |
453 | __sti_mwait(0, 0); | |
454 | else | |
455 | local_irq_enable(); | |
e43d0189 | 456 | trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id()); |
f8e617f4 | 457 | } else { |
b253149b | 458 | local_irq_enable(); |
f8e617f4 MG |
459 | } |
460 | __current_clr_polling(); | |
b253149b LB |
461 | } |
462 | ||
148f9bb8 | 463 | void select_idle_routine(const struct cpuinfo_x86 *c) |
7f424a8b | 464 | { |
3e5095d1 | 465 | #ifdef CONFIG_SMP |
7d1a9417 | 466 | if (boot_option_idle_override == IDLE_POLL && smp_num_siblings > 1) |
c767a54b | 467 | pr_warn_once("WARNING: polling idle and HT enabled, performance may degrade\n"); |
7f424a8b | 468 | #endif |
7d1a9417 | 469 | if (x86_idle || boot_option_idle_override == IDLE_POLL) |
6ddd2a27 TG |
470 | return; |
471 | ||
3344ed30 | 472 | if (boot_cpu_has_bug(X86_BUG_AMD_E400)) { |
c767a54b | 473 | pr_info("using AMD E400 aware idle routine\n"); |
a476bda3 | 474 | x86_idle = amd_e400_idle; |
b253149b LB |
475 | } else if (prefer_mwait_c1_over_halt(c)) { |
476 | pr_info("using mwait in idle threads\n"); | |
477 | x86_idle = mwait_idle; | |
6ddd2a27 | 478 | } else |
a476bda3 | 479 | x86_idle = default_idle; |
7f424a8b PZ |
480 | } |
481 | ||
07c94a38 | 482 | void amd_e400_c1e_apic_setup(void) |
30e1e6d1 | 483 | { |
07c94a38 BP |
484 | if (boot_cpu_has_bug(X86_BUG_AMD_APIC_C1E)) { |
485 | pr_info("Switch to broadcast mode on CPU%d\n", smp_processor_id()); | |
486 | local_irq_disable(); | |
487 | tick_broadcast_force(); | |
488 | local_irq_enable(); | |
489 | } | |
30e1e6d1 RR |
490 | } |
491 | ||
e7ff3a47 TG |
492 | void __init arch_post_acpi_subsys_init(void) |
493 | { | |
494 | u32 lo, hi; | |
495 | ||
496 | if (!boot_cpu_has_bug(X86_BUG_AMD_E400)) | |
497 | return; | |
498 | ||
499 | /* | |
500 | * AMD E400 detection needs to happen after ACPI has been enabled. If | |
501 | * the machine is affected K8_INTP_C1E_ACTIVE_MASK bits are set in | |
502 | * MSR_K8_INT_PENDING_MSG. | |
503 | */ | |
504 | rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi); | |
505 | if (!(lo & K8_INTP_C1E_ACTIVE_MASK)) | |
506 | return; | |
507 | ||
508 | boot_cpu_set_bug(X86_BUG_AMD_APIC_C1E); | |
509 | ||
510 | if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC)) | |
511 | mark_tsc_unstable("TSC halt in AMD C1E"); | |
512 | pr_info("System has AMD C1E enabled\n"); | |
513 | } | |
514 | ||
7f424a8b PZ |
515 | static int __init idle_setup(char *str) |
516 | { | |
ab6bc3e3 CG |
517 | if (!str) |
518 | return -EINVAL; | |
519 | ||
7f424a8b | 520 | if (!strcmp(str, "poll")) { |
c767a54b | 521 | pr_info("using polling idle threads\n"); |
d1896049 | 522 | boot_option_idle_override = IDLE_POLL; |
7d1a9417 | 523 | cpu_idle_poll_ctrl(true); |
d1896049 | 524 | } else if (!strcmp(str, "halt")) { |
c1e3b377 ZY |
525 | /* |
526 | * When the boot option of idle=halt is added, halt is | |
527 | * forced to be used for CPU idle. In such case CPU C2/C3 | |
528 | * won't be used again. | |
529 | * To continue to load the CPU idle driver, don't touch | |
530 | * the boot_option_idle_override. | |
531 | */ | |
a476bda3 | 532 | x86_idle = default_idle; |
d1896049 | 533 | boot_option_idle_override = IDLE_HALT; |
da5e09a1 ZY |
534 | } else if (!strcmp(str, "nomwait")) { |
535 | /* | |
536 | * If the boot option of "idle=nomwait" is added, | |
537 | * it means that mwait will be disabled for CPU C2/C3 | |
538 | * states. In such case it won't touch the variable | |
539 | * of boot_option_idle_override. | |
540 | */ | |
d1896049 | 541 | boot_option_idle_override = IDLE_NOMWAIT; |
c1e3b377 | 542 | } else |
7f424a8b PZ |
543 | return -1; |
544 | ||
7f424a8b PZ |
545 | return 0; |
546 | } | |
547 | early_param("idle", idle_setup); | |
548 | ||
9d62dcdf AW |
549 | unsigned long arch_align_stack(unsigned long sp) |
550 | { | |
551 | if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space) | |
552 | sp -= get_random_int() % 8192; | |
553 | return sp & ~0xf; | |
554 | } | |
555 | ||
556 | unsigned long arch_randomize_brk(struct mm_struct *mm) | |
557 | { | |
9c6f0902 | 558 | return randomize_page(mm->brk, 0x02000000); |
9d62dcdf AW |
559 | } |
560 | ||
7ba78053 TG |
561 | /* |
562 | * Called from fs/proc with a reference on @p to find the function | |
563 | * which called into schedule(). This needs to be done carefully | |
564 | * because the task might wake up and we might look at a stack | |
565 | * changing under us. | |
566 | */ | |
567 | unsigned long get_wchan(struct task_struct *p) | |
568 | { | |
74327a3e | 569 | unsigned long start, bottom, top, sp, fp, ip, ret = 0; |
7ba78053 TG |
570 | int count = 0; |
571 | ||
572 | if (!p || p == current || p->state == TASK_RUNNING) | |
573 | return 0; | |
574 | ||
74327a3e AL |
575 | if (!try_get_task_stack(p)) |
576 | return 0; | |
577 | ||
7ba78053 TG |
578 | start = (unsigned long)task_stack_page(p); |
579 | if (!start) | |
74327a3e | 580 | goto out; |
7ba78053 TG |
581 | |
582 | /* | |
583 | * Layout of the stack page: | |
584 | * | |
585 | * ----------- topmax = start + THREAD_SIZE - sizeof(unsigned long) | |
586 | * PADDING | |
587 | * ----------- top = topmax - TOP_OF_KERNEL_STACK_PADDING | |
588 | * stack | |
15f4eae7 | 589 | * ----------- bottom = start |
7ba78053 TG |
590 | * |
591 | * The tasks stack pointer points at the location where the | |
592 | * framepointer is stored. The data on the stack is: | |
593 | * ... IP FP ... IP FP | |
594 | * | |
595 | * We need to read FP and IP, so we need to adjust the upper | |
596 | * bound by another unsigned long. | |
597 | */ | |
598 | top = start + THREAD_SIZE - TOP_OF_KERNEL_STACK_PADDING; | |
599 | top -= 2 * sizeof(unsigned long); | |
15f4eae7 | 600 | bottom = start; |
7ba78053 TG |
601 | |
602 | sp = READ_ONCE(p->thread.sp); | |
603 | if (sp < bottom || sp > top) | |
74327a3e | 604 | goto out; |
7ba78053 | 605 | |
7b32aead | 606 | fp = READ_ONCE_NOCHECK(((struct inactive_task_frame *)sp)->bp); |
7ba78053 TG |
607 | do { |
608 | if (fp < bottom || fp > top) | |
74327a3e | 609 | goto out; |
f7d27c35 | 610 | ip = READ_ONCE_NOCHECK(*(unsigned long *)(fp + sizeof(unsigned long))); |
74327a3e AL |
611 | if (!in_sched_functions(ip)) { |
612 | ret = ip; | |
613 | goto out; | |
614 | } | |
f7d27c35 | 615 | fp = READ_ONCE_NOCHECK(*(unsigned long *)fp); |
7ba78053 | 616 | } while (count++ < 16 && p->state != TASK_RUNNING); |
74327a3e AL |
617 | |
618 | out: | |
619 | put_task_stack(p); | |
620 | return ret; | |
7ba78053 | 621 | } |
b0b9b014 KH |
622 | |
623 | long do_arch_prctl_common(struct task_struct *task, int option, | |
624 | unsigned long cpuid_enabled) | |
625 | { | |
e9ea1e7f KH |
626 | switch (option) { |
627 | case ARCH_GET_CPUID: | |
628 | return get_cpuid_mode(); | |
629 | case ARCH_SET_CPUID: | |
630 | return set_cpuid_mode(task, cpuid_enabled); | |
631 | } | |
632 | ||
b0b9b014 KH |
633 | return -EINVAL; |
634 | } |