1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Suspend support specific for i386/x86-64.
4 *
5 * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl>
6 * Copyright (c) 2002 Pavel Machek <pavel@ucw.cz>
7 * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
8 */
9
10 #include <linux/suspend.h>
11 #include <linux/export.h>
12 #include <linux/smp.h>
13 #include <linux/perf_event.h>
14 #include <linux/tboot.h>
15 #include <linux/dmi.h>
16 #include <linux/pgtable.h>
17
18 #include <asm/proto.h>
19 #include <asm/mtrr.h>
20 #include <asm/page.h>
21 #include <asm/mce.h>
22 #include <asm/suspend.h>
23 #include <asm/fpu/api.h>
24 #include <asm/debugreg.h>
25 #include <asm/cpu.h>
26 #include <asm/cacheinfo.h>
27 #include <asm/mmu_context.h>
28 #include <asm/cpu_device_id.h>
29 #include <asm/microcode.h>
30 #include <asm/msr.h>
31 #include <asm/fred.h>
32
33 #ifdef CONFIG_X86_32
34 __visible unsigned long saved_context_ebx;
35 __visible unsigned long saved_context_esp, saved_context_ebp;
36 __visible unsigned long saved_context_esi, saved_context_edi;
37 __visible unsigned long saved_context_eflags;
38 #endif
39 struct saved_context saved_context;
40
msr_save_context(struct saved_context * ctxt)41 static void msr_save_context(struct saved_context *ctxt)
42 {
43 struct saved_msr *msr = ctxt->saved_msrs.array;
44 struct saved_msr *end = msr + ctxt->saved_msrs.num;
45
46 while (msr < end) {
47 if (msr->valid)
48 rdmsrq(msr->info.msr_no, msr->info.reg.q);
49 msr++;
50 }
51 }
52
msr_restore_context(struct saved_context * ctxt)53 static void msr_restore_context(struct saved_context *ctxt)
54 {
55 struct saved_msr *msr = ctxt->saved_msrs.array;
56 struct saved_msr *end = msr + ctxt->saved_msrs.num;
57
58 while (msr < end) {
59 if (msr->valid)
60 wrmsrq(msr->info.msr_no, msr->info.reg.q);
61 msr++;
62 }
63 }
64
65 /**
66 * __save_processor_state() - Save CPU registers before creating a
67 * hibernation image and before restoring
68 * the memory state from it
69 * @ctxt: Structure to store the registers contents in.
70 *
71 * NOTE: If there is a CPU register the modification of which by the
72 * boot kernel (ie. the kernel used for loading the hibernation image)
73 * might affect the operations of the restored target kernel (ie. the one
74 * saved in the hibernation image), then its contents must be saved by this
75 * function. In other words, if kernel A is hibernated and different
76 * kernel B is used for loading the hibernation image into memory, the
77 * kernel A's __save_processor_state() function must save all registers
78 * needed by kernel A, so that it can operate correctly after the resume
79 * regardless of what kernel B does in the meantime.
80 */
__save_processor_state(struct saved_context * ctxt)81 static void __save_processor_state(struct saved_context *ctxt)
82 {
83 #ifdef CONFIG_X86_32
84 mtrr_save_fixed_ranges(NULL);
85 #endif
86 kernel_fpu_begin();
87
88 /*
89 * descriptor tables
90 */
91 store_idt(&ctxt->idt);
92
93 /*
94 * We save it here, but restore it only in the hibernate case.
95 * For ACPI S3 resume, this is loaded via 'early_gdt_desc' in 64-bit
96 * mode in "secondary_startup_64". In 32-bit mode it is done via
97 * 'pmode_gdt' in wakeup_start.
98 */
99 ctxt->gdt_desc.size = GDT_SIZE - 1;
100 ctxt->gdt_desc.address = (unsigned long)get_cpu_gdt_rw(smp_processor_id());
101
102 store_tr(ctxt->tr);
103
104 /* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
105 /*
106 * segment registers
107 */
108 savesegment(gs, ctxt->gs);
109 #ifdef CONFIG_X86_64
110 savesegment(fs, ctxt->fs);
111 savesegment(ds, ctxt->ds);
112 savesegment(es, ctxt->es);
113
114 rdmsrq(MSR_FS_BASE, ctxt->fs_base);
115 rdmsrq(MSR_GS_BASE, ctxt->kernelmode_gs_base);
116 rdmsrq(MSR_KERNEL_GS_BASE, ctxt->usermode_gs_base);
117 mtrr_save_fixed_ranges(NULL);
118
119 rdmsrq(MSR_EFER, ctxt->efer);
120 #endif
121
122 /*
123 * control registers
124 */
125 ctxt->cr0 = read_cr0();
126 ctxt->cr2 = read_cr2();
127 ctxt->cr3 = __read_cr3();
128 ctxt->cr4 = __read_cr4();
129 ctxt->misc_enable_saved = !rdmsrq_safe(MSR_IA32_MISC_ENABLE,
130 &ctxt->misc_enable);
131 msr_save_context(ctxt);
132 }
133
134 /* Needed by apm.c */
save_processor_state(void)135 void save_processor_state(void)
136 {
137 __save_processor_state(&saved_context);
138 x86_platform.save_sched_clock_state();
139 }
140 #ifdef CONFIG_X86_32
141 EXPORT_SYMBOL(save_processor_state);
142 #endif
143
do_fpu_end(void)144 static void do_fpu_end(void)
145 {
146 /*
147 * Restore FPU regs if necessary.
148 */
149 kernel_fpu_end();
150 }
151
fix_processor_context(void)152 static void fix_processor_context(void)
153 {
154 int cpu = smp_processor_id();
155 #ifdef CONFIG_X86_64
156 struct desc_struct *desc = get_cpu_gdt_rw(cpu);
157 tss_desc tss;
158 #endif
159
160 /*
161 * We need to reload TR, which requires that we change the
162 * GDT entry to indicate "available" first.
163 *
164 * XXX: This could probably all be replaced by a call to
165 * force_reload_TR().
166 */
167 set_tss_desc(cpu, &get_cpu_entry_area(cpu)->tss.x86_tss);
168
169 #ifdef CONFIG_X86_64
170 memcpy(&tss, &desc[GDT_ENTRY_TSS], sizeof(tss_desc));
171 tss.type = 0x9; /* The available 64-bit TSS (see AMD vol 2, pg 91 */
172 write_gdt_entry(desc, GDT_ENTRY_TSS, &tss, DESC_TSS);
173
174 syscall_init(); /* This sets MSR_*STAR and related */
175 #else
176 if (boot_cpu_has(X86_FEATURE_SEP))
177 enable_sep_cpu();
178 #endif
179 load_TR_desc(); /* This does ltr */
180 load_mm_ldt(current->active_mm); /* This does lldt */
181 initialize_tlbstate_and_flush();
182
183 fpu__resume_cpu();
184
185 /* The processor is back on the direct GDT, load back the fixmap */
186 load_fixmap_gdt(cpu);
187 }
188
189 /**
190 * __restore_processor_state() - Restore the contents of CPU registers saved
191 * by __save_processor_state()
192 * @ctxt: Structure to load the registers contents from.
193 *
194 * The asm code that gets us here will have restored a usable GDT, although
195 * it will be pointing to the wrong alias.
196 */
__restore_processor_state(struct saved_context * ctxt)197 static void notrace __restore_processor_state(struct saved_context *ctxt)
198 {
199 struct cpuinfo_x86 *c;
200
201 if (ctxt->misc_enable_saved)
202 wrmsrq(MSR_IA32_MISC_ENABLE, ctxt->misc_enable);
203 /*
204 * control registers
205 */
206 /* cr4 was introduced in the Pentium CPU */
207 #ifdef CONFIG_X86_32
208 if (ctxt->cr4)
209 __write_cr4(ctxt->cr4);
210 #else
211 /* CONFIG X86_64 */
212 wrmsrq(MSR_EFER, ctxt->efer);
213 __write_cr4(ctxt->cr4);
214 #endif
215 write_cr3(ctxt->cr3);
216 write_cr2(ctxt->cr2);
217 write_cr0(ctxt->cr0);
218
219 /* Restore the IDT. */
220 load_idt(&ctxt->idt);
221
222 /*
223 * Just in case the asm code got us here with the SS, DS, or ES
224 * out of sync with the GDT, update them.
225 */
226 loadsegment(ss, __KERNEL_DS);
227 loadsegment(ds, __USER_DS);
228 loadsegment(es, __USER_DS);
229
230 /*
231 * Restore percpu access. Percpu access can happen in exception
232 * handlers or in complicated helpers like load_gs_index().
233 */
234 #ifdef CONFIG_X86_64
235 wrmsrq(MSR_GS_BASE, ctxt->kernelmode_gs_base);
236
237 /*
238 * Reinitialize FRED to ensure the FRED MSRs contain the same values
239 * as before hibernation.
240 *
241 * Note, the setup of FRED RSPs requires access to percpu data
242 * structures. Therefore, FRED reinitialization can only occur after
243 * the percpu access pointer (i.e., MSR_GS_BASE) is restored.
244 */
245 if (ctxt->cr4 & X86_CR4_FRED) {
246 cpu_init_fred_exceptions();
247 cpu_init_fred_rsps();
248 }
249 #else
250 loadsegment(fs, __KERNEL_PERCPU);
251 #endif
252
253 /* Restore the TSS, RO GDT, LDT, and usermode-relevant MSRs. */
254 fix_processor_context();
255
256 /*
257 * Now that we have descriptor tables fully restored and working
258 * exception handling, restore the usermode segments.
259 */
260 #ifdef CONFIG_X86_64
261 loadsegment(ds, ctxt->es);
262 loadsegment(es, ctxt->es);
263 loadsegment(fs, ctxt->fs);
264 load_gs_index(ctxt->gs);
265
266 /*
267 * Restore FSBASE and GSBASE after restoring the selectors, since
268 * restoring the selectors clobbers the bases. Keep in mind
269 * that MSR_KERNEL_GS_BASE is horribly misnamed.
270 */
271 wrmsrq(MSR_FS_BASE, ctxt->fs_base);
272 wrmsrq(MSR_KERNEL_GS_BASE, ctxt->usermode_gs_base);
273 #else
274 loadsegment(gs, ctxt->gs);
275 #endif
276
277 do_fpu_end();
278 tsc_verify_tsc_adjust(true);
279 x86_platform.restore_sched_clock_state();
280 cache_bp_restore();
281 perf_restore_debug_store();
282
283 c = &cpu_data(smp_processor_id());
284 if (cpu_has(c, X86_FEATURE_MSR_IA32_FEAT_CTL))
285 init_ia32_feat_ctl(c);
286
287 microcode_bsp_resume();
288
289 /*
290 * This needs to happen after the microcode has been updated upon resume
291 * because some of the MSRs are "emulated" in microcode.
292 */
293 msr_restore_context(ctxt);
294 }
295
296 /* Needed by apm.c */
restore_processor_state(void)297 void notrace restore_processor_state(void)
298 {
299 __restore_processor_state(&saved_context);
300 }
301 #ifdef CONFIG_X86_32
302 EXPORT_SYMBOL(restore_processor_state);
303 #endif
304
305 #if defined(CONFIG_HIBERNATION) && defined(CONFIG_HOTPLUG_CPU)
resume_play_dead(void)306 static void __noreturn resume_play_dead(void)
307 {
308 play_dead_common();
309 tboot_shutdown(TB_SHUTDOWN_WFS);
310 hlt_play_dead();
311 }
312
hibernate_resume_nonboot_cpu_disable(void)313 int hibernate_resume_nonboot_cpu_disable(void)
314 {
315 void (*play_dead)(void) = smp_ops.play_dead;
316 int ret;
317
318 /*
319 * Ensure that MONITOR/MWAIT will not be used in the "play dead" loop
320 * during hibernate image restoration, because it is likely that the
321 * monitored address will be actually written to at that time and then
322 * the "dead" CPU will attempt to execute instructions again, but the
323 * address in its instruction pointer may not be possible to resolve
324 * any more at that point (the page tables used by it previously may
325 * have been overwritten by hibernate image data).
326 *
327 * First, make sure that we wake up all the potentially disabled SMT
328 * threads which have been initially brought up and then put into
329 * mwait/cpuidle sleep.
330 * Those will be put to proper (not interfering with hibernation
331 * resume) sleep afterwards, and the resumed kernel will decide itself
332 * what to do with them.
333 */
334 ret = cpuhp_smt_enable();
335 if (ret)
336 return ret;
337 smp_ops.play_dead = resume_play_dead;
338 ret = freeze_secondary_cpus(0);
339 smp_ops.play_dead = play_dead;
340 return ret;
341 }
342 #endif
343
344 /*
345 * When bsp_check() is called in hibernate and suspend, cpu hotplug
346 * is disabled already. So it's unnecessary to handle race condition between
347 * cpumask query and cpu hotplug.
348 */
bsp_check(void)349 static int bsp_check(void)
350 {
351 if (cpumask_first(cpu_online_mask) != 0) {
352 pr_warn("CPU0 is offline.\n");
353 return -ENODEV;
354 }
355
356 return 0;
357 }
358
bsp_pm_callback(struct notifier_block * nb,unsigned long action,void * ptr)359 static int bsp_pm_callback(struct notifier_block *nb, unsigned long action,
360 void *ptr)
361 {
362 int ret = 0;
363
364 switch (action) {
365 case PM_SUSPEND_PREPARE:
366 case PM_HIBERNATION_PREPARE:
367 ret = bsp_check();
368 break;
369 default:
370 break;
371 }
372 return notifier_from_errno(ret);
373 }
374
bsp_pm_check_init(void)375 static int __init bsp_pm_check_init(void)
376 {
377 /*
378 * Set this bsp_pm_callback as lower priority than
379 * cpu_hotplug_pm_callback. So cpu_hotplug_pm_callback will be called
380 * earlier to disable cpu hotplug before bsp online check.
381 */
382 pm_notifier(bsp_pm_callback, -INT_MAX);
383 return 0;
384 }
385
386 core_initcall(bsp_pm_check_init);
387
msr_build_context(const u32 * msr_id,const int num)388 static int msr_build_context(const u32 *msr_id, const int num)
389 {
390 struct saved_msrs *saved_msrs = &saved_context.saved_msrs;
391 struct saved_msr *msr_array;
392 int total_num;
393 int i, j;
394
395 total_num = saved_msrs->num + num;
396
397 msr_array = kmalloc_array(total_num, sizeof(struct saved_msr), GFP_KERNEL);
398 if (!msr_array) {
399 pr_err("x86/pm: Can not allocate memory to save/restore MSRs during suspend.\n");
400 return -ENOMEM;
401 }
402
403 if (saved_msrs->array) {
404 /*
405 * Multiple callbacks can invoke this function, so copy any
406 * MSR save requests from previous invocations.
407 */
408 memcpy(msr_array, saved_msrs->array,
409 sizeof(struct saved_msr) * saved_msrs->num);
410
411 kfree(saved_msrs->array);
412 }
413
414 for (i = saved_msrs->num, j = 0; i < total_num; i++, j++) {
415 u64 dummy;
416
417 msr_array[i].info.msr_no = msr_id[j];
418 msr_array[i].valid = !rdmsrq_safe(msr_id[j], &dummy);
419 msr_array[i].info.reg.q = 0;
420 }
421 saved_msrs->num = total_num;
422 saved_msrs->array = msr_array;
423
424 return 0;
425 }
426
427 /*
428 * The following sections are a quirk framework for problematic BIOSen:
429 * Sometimes MSRs are modified by the BIOSen after suspended to
430 * RAM, this might cause unexpected behavior after wakeup.
431 * Thus we save/restore these specified MSRs across suspend/resume
432 * in order to work around it.
433 *
434 * For any further problematic BIOSen/platforms,
435 * please add your own function similar to msr_initialize_bdw.
436 */
msr_initialize_bdw(const struct dmi_system_id * d)437 static int msr_initialize_bdw(const struct dmi_system_id *d)
438 {
439 /* Add any extra MSR ids into this array. */
440 u32 bdw_msr_id[] = { MSR_IA32_THERM_CONTROL };
441
442 pr_info("x86/pm: %s detected, MSR saving is needed during suspending.\n", d->ident);
443 return msr_build_context(bdw_msr_id, ARRAY_SIZE(bdw_msr_id));
444 }
445
446 static const struct dmi_system_id msr_save_dmi_table[] = {
447 {
448 .callback = msr_initialize_bdw,
449 .ident = "BROADWELL BDX_EP",
450 .matches = {
451 DMI_MATCH(DMI_PRODUCT_NAME, "GRANTLEY"),
452 DMI_MATCH(DMI_PRODUCT_VERSION, "E63448-400"),
453 },
454 },
455 {}
456 };
457
msr_save_cpuid_features(const struct x86_cpu_id * c)458 static int msr_save_cpuid_features(const struct x86_cpu_id *c)
459 {
460 u32 cpuid_msr_id[] = {
461 MSR_AMD64_CPUID_FN_1,
462 };
463
464 pr_info("x86/pm: family %#hx cpu detected, MSR saving is needed during suspending.\n",
465 c->family);
466
467 return msr_build_context(cpuid_msr_id, ARRAY_SIZE(cpuid_msr_id));
468 }
469
470 static const struct x86_cpu_id msr_save_cpu_table[] = {
471 X86_MATCH_VENDOR_FAM(AMD, 0x15, &msr_save_cpuid_features),
472 X86_MATCH_VENDOR_FAM(AMD, 0x16, &msr_save_cpuid_features),
473 {}
474 };
475
476 typedef int (*pm_cpu_match_t)(const struct x86_cpu_id *);
pm_cpu_check(const struct x86_cpu_id * c)477 static int pm_cpu_check(const struct x86_cpu_id *c)
478 {
479 const struct x86_cpu_id *m;
480 int ret = 0;
481
482 m = x86_match_cpu(msr_save_cpu_table);
483 if (m) {
484 pm_cpu_match_t fn;
485
486 fn = (pm_cpu_match_t)m->driver_data;
487 ret = fn(m);
488 }
489
490 return ret;
491 }
492
pm_save_spec_msr(void)493 static void pm_save_spec_msr(void)
494 {
495 struct msr_enumeration {
496 u32 msr_no;
497 u32 feature;
498 } msr_enum[] = {
499 { MSR_IA32_SPEC_CTRL, X86_FEATURE_MSR_SPEC_CTRL },
500 { MSR_IA32_TSX_CTRL, X86_FEATURE_MSR_TSX_CTRL },
501 { MSR_TSX_FORCE_ABORT, X86_FEATURE_TSX_FORCE_ABORT },
502 { MSR_IA32_MCU_OPT_CTRL, X86_FEATURE_SRBDS_CTRL },
503 { MSR_AMD64_LS_CFG, X86_FEATURE_LS_CFG_SSBD },
504 { MSR_AMD64_DE_CFG, X86_FEATURE_LFENCE_RDTSC },
505 };
506 int i;
507
508 for (i = 0; i < ARRAY_SIZE(msr_enum); i++) {
509 if (boot_cpu_has(msr_enum[i].feature))
510 msr_build_context(&msr_enum[i].msr_no, 1);
511 }
512 }
513
pm_check_save_msr(void)514 static int pm_check_save_msr(void)
515 {
516 dmi_check_system(msr_save_dmi_table);
517 pm_cpu_check(msr_save_cpu_table);
518 pm_save_spec_msr();
519
520 return 0;
521 }
522
523 device_initcall(pm_check_save_msr);
524