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1// SPDX-License-Identifier: GPL-2.0-only
2/*:
3 * Hibernate support specific for ARM64
4 *
5 * Derived from work on ARM hibernation support by:
6 *
7 * Ubuntu project, hibernation support for mach-dove
8 * Copyright (C) 2010 Nokia Corporation (Hiroshi Doyu)
9 * Copyright (C) 2010 Texas Instruments, Inc. (Teerth Reddy et al.)
10 * https://lkml.org/lkml/2010/6/18/4
11 * https://lists.linux-foundation.org/pipermail/linux-pm/2010-June/027422.html
12 * https://patchwork.kernel.org/patch/96442/
13 *
14 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
15 */
16#define pr_fmt(x) "hibernate: " x
17#include <linux/cpu.h>
18#include <linux/kvm_host.h>
19#include <linux/mm.h>
20#include <linux/pm.h>
21#include <linux/sched.h>
22#include <linux/suspend.h>
23#include <linux/utsname.h>
24#include <linux/version.h>
25
26#include <asm/barrier.h>
27#include <asm/cacheflush.h>
28#include <asm/cputype.h>
29#include <asm/daifflags.h>
30#include <asm/irqflags.h>
31#include <asm/kexec.h>
32#include <asm/memory.h>
33#include <asm/mmu_context.h>
34#include <asm/pgalloc.h>
35#include <asm/pgtable.h>
36#include <asm/pgtable-hwdef.h>
37#include <asm/sections.h>
38#include <asm/smp.h>
39#include <asm/smp_plat.h>
40#include <asm/suspend.h>
41#include <asm/sysreg.h>
42#include <asm/virt.h>
43
44/*
45 * Hibernate core relies on this value being 0 on resume, and marks it
46 * __nosavedata assuming it will keep the resume kernel's '0' value. This
47 * doesn't happen with either KASLR.
48 *
49 * defined as "__visible int in_suspend __nosavedata" in
50 * kernel/power/hibernate.c
51 */
52extern int in_suspend;
53
54/* Do we need to reset el2? */
55#define el2_reset_needed() (is_hyp_mode_available() && !is_kernel_in_hyp_mode())
56
57/* temporary el2 vectors in the __hibernate_exit_text section. */
58extern char hibernate_el2_vectors[];
59
60/* hyp-stub vectors, used to restore el2 during resume from hibernate. */
61extern char __hyp_stub_vectors[];
62
63/*
64 * The logical cpu number we should resume on, initialised to a non-cpu
65 * number.
66 */
67static int sleep_cpu = -EINVAL;
68
69/*
70 * Values that may not change over hibernate/resume. We put the build number
71 * and date in here so that we guarantee not to resume with a different
72 * kernel.
73 */
74struct arch_hibernate_hdr_invariants {
75 char uts_version[__NEW_UTS_LEN + 1];
76};
77
78/* These values need to be know across a hibernate/restore. */
79static struct arch_hibernate_hdr {
80 struct arch_hibernate_hdr_invariants invariants;
81
82 /* These are needed to find the relocated kernel if built with kaslr */
83 phys_addr_t ttbr1_el1;
84 void (*reenter_kernel)(void);
85
86 /*
87 * We need to know where the __hyp_stub_vectors are after restore to
88 * re-configure el2.
89 */
90 phys_addr_t __hyp_stub_vectors;
91
92 u64 sleep_cpu_mpidr;
93} resume_hdr;
94
95static inline void arch_hdr_invariants(struct arch_hibernate_hdr_invariants *i)
96{
97 memset(i, 0, sizeof(*i));
98 memcpy(i->uts_version, init_utsname()->version, sizeof(i->uts_version));
99}
100
101int pfn_is_nosave(unsigned long pfn)
102{
103 unsigned long nosave_begin_pfn = sym_to_pfn(&__nosave_begin);
104 unsigned long nosave_end_pfn = sym_to_pfn(&__nosave_end - 1);
105
106 return ((pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn)) ||
107 crash_is_nosave(pfn);
108}
109
110void notrace save_processor_state(void)
111{
112 WARN_ON(num_online_cpus() != 1);
113}
114
115void notrace restore_processor_state(void)
116{
117}
118
119int arch_hibernation_header_save(void *addr, unsigned int max_size)
120{
121 struct arch_hibernate_hdr *hdr = addr;
122
123 if (max_size < sizeof(*hdr))
124 return -EOVERFLOW;
125
126 arch_hdr_invariants(&hdr->invariants);
127 hdr->ttbr1_el1 = __pa_symbol(swapper_pg_dir);
128 hdr->reenter_kernel = _cpu_resume;
129
130 /* We can't use __hyp_get_vectors() because kvm may still be loaded */
131 if (el2_reset_needed())
132 hdr->__hyp_stub_vectors = __pa_symbol(__hyp_stub_vectors);
133 else
134 hdr->__hyp_stub_vectors = 0;
135
136 /* Save the mpidr of the cpu we called cpu_suspend() on... */
137 if (sleep_cpu < 0) {
138 pr_err("Failing to hibernate on an unknown CPU.\n");
139 return -ENODEV;
140 }
141 hdr->sleep_cpu_mpidr = cpu_logical_map(sleep_cpu);
142 pr_info("Hibernating on CPU %d [mpidr:0x%llx]\n", sleep_cpu,
143 hdr->sleep_cpu_mpidr);
144
145 return 0;
146}
147EXPORT_SYMBOL(arch_hibernation_header_save);
148
149int arch_hibernation_header_restore(void *addr)
150{
151 int ret;
152 struct arch_hibernate_hdr_invariants invariants;
153 struct arch_hibernate_hdr *hdr = addr;
154
155 arch_hdr_invariants(&invariants);
156 if (memcmp(&hdr->invariants, &invariants, sizeof(invariants))) {
157 pr_crit("Hibernate image not generated by this kernel!\n");
158 return -EINVAL;
159 }
160
161 sleep_cpu = get_logical_index(hdr->sleep_cpu_mpidr);
162 pr_info("Hibernated on CPU %d [mpidr:0x%llx]\n", sleep_cpu,
163 hdr->sleep_cpu_mpidr);
164 if (sleep_cpu < 0) {
165 pr_crit("Hibernated on a CPU not known to this kernel!\n");
166 sleep_cpu = -EINVAL;
167 return -EINVAL;
168 }
169 if (!cpu_online(sleep_cpu)) {
170 pr_info("Hibernated on a CPU that is offline! Bringing CPU up.\n");
171 ret = cpu_up(sleep_cpu);
172 if (ret) {
173 pr_err("Failed to bring hibernate-CPU up!\n");
174 sleep_cpu = -EINVAL;
175 return ret;
176 }
177 }
178
179 resume_hdr = *hdr;
180
181 return 0;
182}
183EXPORT_SYMBOL(arch_hibernation_header_restore);
184
185/*
186 * Copies length bytes, starting at src_start into an new page,
187 * perform cache maintentance, then maps it at the specified address low
188 * address as executable.
189 *
190 * This is used by hibernate to copy the code it needs to execute when
191 * overwriting the kernel text. This function generates a new set of page
192 * tables, which it loads into ttbr0.
193 *
194 * Length is provided as we probably only want 4K of data, even on a 64K
195 * page system.
196 */
197static int create_safe_exec_page(void *src_start, size_t length,
198 unsigned long dst_addr,
199 phys_addr_t *phys_dst_addr,
200 void *(*allocator)(gfp_t mask),
201 gfp_t mask)
202{
203 int rc = 0;
204 pgd_t *trans_pgd;
205 pgd_t *pgdp;
206 pud_t *pudp;
207 pmd_t *pmdp;
208 pte_t *ptep;
209 unsigned long dst = (unsigned long)allocator(mask);
210
211 if (!dst) {
212 rc = -ENOMEM;
213 goto out;
214 }
215
216 memcpy((void *)dst, src_start, length);
217 __flush_icache_range(dst, dst + length);
218
219 trans_pgd = allocator(mask);
220 if (!trans_pgd) {
221 rc = -ENOMEM;
222 goto out;
223 }
224
225 pgdp = pgd_offset_raw(trans_pgd, dst_addr);
226 if (pgd_none(READ_ONCE(*pgdp))) {
227 pudp = allocator(mask);
228 if (!pudp) {
229 rc = -ENOMEM;
230 goto out;
231 }
232 pgd_populate(&init_mm, pgdp, pudp);
233 }
234
235 pudp = pud_offset(pgdp, dst_addr);
236 if (pud_none(READ_ONCE(*pudp))) {
237 pmdp = allocator(mask);
238 if (!pmdp) {
239 rc = -ENOMEM;
240 goto out;
241 }
242 pud_populate(&init_mm, pudp, pmdp);
243 }
244
245 pmdp = pmd_offset(pudp, dst_addr);
246 if (pmd_none(READ_ONCE(*pmdp))) {
247 ptep = allocator(mask);
248 if (!ptep) {
249 rc = -ENOMEM;
250 goto out;
251 }
252 pmd_populate_kernel(&init_mm, pmdp, ptep);
253 }
254
255 ptep = pte_offset_kernel(pmdp, dst_addr);
256 set_pte(ptep, pfn_pte(virt_to_pfn(dst), PAGE_KERNEL_EXEC));
257
258 /*
259 * Load our new page tables. A strict BBM approach requires that we
260 * ensure that TLBs are free of any entries that may overlap with the
261 * global mappings we are about to install.
262 *
263 * For a real hibernate/resume cycle TTBR0 currently points to a zero
264 * page, but TLBs may contain stale ASID-tagged entries (e.g. for EFI
265 * runtime services), while for a userspace-driven test_resume cycle it
266 * points to userspace page tables (and we must point it at a zero page
267 * ourselves). Elsewhere we only (un)install the idmap with preemption
268 * disabled, so T0SZ should be as required regardless.
269 */
270 cpu_set_reserved_ttbr0();
271 local_flush_tlb_all();
272 write_sysreg(phys_to_ttbr(virt_to_phys(pgdp)), ttbr0_el1);
273 isb();
274
275 *phys_dst_addr = virt_to_phys((void *)dst);
276
277out:
278 return rc;
279}
280
281#define dcache_clean_range(start, end) __flush_dcache_area(start, (end - start))
282
283int swsusp_arch_suspend(void)
284{
285 int ret = 0;
286 unsigned long flags;
287 struct sleep_stack_data state;
288
289 if (cpus_are_stuck_in_kernel()) {
290 pr_err("Can't hibernate: no mechanism to offline secondary CPUs.\n");
291 return -EBUSY;
292 }
293
294 flags = local_daif_save();
295
296 if (__cpu_suspend_enter(&state)) {
297 /* make the crash dump kernel image visible/saveable */
298 crash_prepare_suspend();
299
300 sleep_cpu = smp_processor_id();
301 ret = swsusp_save();
302 } else {
303 /* Clean kernel core startup/idle code to PoC*/
304 dcache_clean_range(__mmuoff_data_start, __mmuoff_data_end);
305 dcache_clean_range(__idmap_text_start, __idmap_text_end);
306
307 /* Clean kvm setup code to PoC? */
308 if (el2_reset_needed()) {
309 dcache_clean_range(__hyp_idmap_text_start, __hyp_idmap_text_end);
310 dcache_clean_range(__hyp_text_start, __hyp_text_end);
311 }
312
313 /* make the crash dump kernel image protected again */
314 crash_post_resume();
315
316 /*
317 * Tell the hibernation core that we've just restored
318 * the memory
319 */
320 in_suspend = 0;
321
322 sleep_cpu = -EINVAL;
323 __cpu_suspend_exit();
324
325 /*
326 * Just in case the boot kernel did turn the SSBD
327 * mitigation off behind our back, let's set the state
328 * to what we expect it to be.
329 */
330 switch (arm64_get_ssbd_state()) {
331 case ARM64_SSBD_FORCE_ENABLE:
332 case ARM64_SSBD_KERNEL:
333 arm64_set_ssbd_mitigation(true);
334 }
335 }
336
337 local_daif_restore(flags);
338
339 return ret;
340}
341
342static void _copy_pte(pte_t *dst_ptep, pte_t *src_ptep, unsigned long addr)
343{
344 pte_t pte = READ_ONCE(*src_ptep);
345
346 if (pte_valid(pte)) {
347 /*
348 * Resume will overwrite areas that may be marked
349 * read only (code, rodata). Clear the RDONLY bit from
350 * the temporary mappings we use during restore.
351 */
352 set_pte(dst_ptep, pte_mkwrite(pte));
353 } else if (debug_pagealloc_enabled() && !pte_none(pte)) {
354 /*
355 * debug_pagealloc will removed the PTE_VALID bit if
356 * the page isn't in use by the resume kernel. It may have
357 * been in use by the original kernel, in which case we need
358 * to put it back in our copy to do the restore.
359 *
360 * Before marking this entry valid, check the pfn should
361 * be mapped.
362 */
363 BUG_ON(!pfn_valid(pte_pfn(pte)));
364
365 set_pte(dst_ptep, pte_mkpresent(pte_mkwrite(pte)));
366 }
367}
368
369static int copy_pte(pmd_t *dst_pmdp, pmd_t *src_pmdp, unsigned long start,
370 unsigned long end)
371{
372 pte_t *src_ptep;
373 pte_t *dst_ptep;
374 unsigned long addr = start;
375
376 dst_ptep = (pte_t *)get_safe_page(GFP_ATOMIC);
377 if (!dst_ptep)
378 return -ENOMEM;
379 pmd_populate_kernel(&init_mm, dst_pmdp, dst_ptep);
380 dst_ptep = pte_offset_kernel(dst_pmdp, start);
381
382 src_ptep = pte_offset_kernel(src_pmdp, start);
383 do {
384 _copy_pte(dst_ptep, src_ptep, addr);
385 } while (dst_ptep++, src_ptep++, addr += PAGE_SIZE, addr != end);
386
387 return 0;
388}
389
390static int copy_pmd(pud_t *dst_pudp, pud_t *src_pudp, unsigned long start,
391 unsigned long end)
392{
393 pmd_t *src_pmdp;
394 pmd_t *dst_pmdp;
395 unsigned long next;
396 unsigned long addr = start;
397
398 if (pud_none(READ_ONCE(*dst_pudp))) {
399 dst_pmdp = (pmd_t *)get_safe_page(GFP_ATOMIC);
400 if (!dst_pmdp)
401 return -ENOMEM;
402 pud_populate(&init_mm, dst_pudp, dst_pmdp);
403 }
404 dst_pmdp = pmd_offset(dst_pudp, start);
405
406 src_pmdp = pmd_offset(src_pudp, start);
407 do {
408 pmd_t pmd = READ_ONCE(*src_pmdp);
409
410 next = pmd_addr_end(addr, end);
411 if (pmd_none(pmd))
412 continue;
413 if (pmd_table(pmd)) {
414 if (copy_pte(dst_pmdp, src_pmdp, addr, next))
415 return -ENOMEM;
416 } else {
417 set_pmd(dst_pmdp,
418 __pmd(pmd_val(pmd) & ~PMD_SECT_RDONLY));
419 }
420 } while (dst_pmdp++, src_pmdp++, addr = next, addr != end);
421
422 return 0;
423}
424
425static int copy_pud(pgd_t *dst_pgdp, pgd_t *src_pgdp, unsigned long start,
426 unsigned long end)
427{
428 pud_t *dst_pudp;
429 pud_t *src_pudp;
430 unsigned long next;
431 unsigned long addr = start;
432
433 if (pgd_none(READ_ONCE(*dst_pgdp))) {
434 dst_pudp = (pud_t *)get_safe_page(GFP_ATOMIC);
435 if (!dst_pudp)
436 return -ENOMEM;
437 pgd_populate(&init_mm, dst_pgdp, dst_pudp);
438 }
439 dst_pudp = pud_offset(dst_pgdp, start);
440
441 src_pudp = pud_offset(src_pgdp, start);
442 do {
443 pud_t pud = READ_ONCE(*src_pudp);
444
445 next = pud_addr_end(addr, end);
446 if (pud_none(pud))
447 continue;
448 if (pud_table(pud)) {
449 if (copy_pmd(dst_pudp, src_pudp, addr, next))
450 return -ENOMEM;
451 } else {
452 set_pud(dst_pudp,
453 __pud(pud_val(pud) & ~PMD_SECT_RDONLY));
454 }
455 } while (dst_pudp++, src_pudp++, addr = next, addr != end);
456
457 return 0;
458}
459
460static int copy_page_tables(pgd_t *dst_pgdp, unsigned long start,
461 unsigned long end)
462{
463 unsigned long next;
464 unsigned long addr = start;
465 pgd_t *src_pgdp = pgd_offset_k(start);
466
467 dst_pgdp = pgd_offset_raw(dst_pgdp, start);
468 do {
469 next = pgd_addr_end(addr, end);
470 if (pgd_none(READ_ONCE(*src_pgdp)))
471 continue;
472 if (copy_pud(dst_pgdp, src_pgdp, addr, next))
473 return -ENOMEM;
474 } while (dst_pgdp++, src_pgdp++, addr = next, addr != end);
475
476 return 0;
477}
478
479/*
480 * Setup then Resume from the hibernate image using swsusp_arch_suspend_exit().
481 *
482 * Memory allocated by get_safe_page() will be dealt with by the hibernate code,
483 * we don't need to free it here.
484 */
485int swsusp_arch_resume(void)
486{
487 int rc = 0;
488 void *zero_page;
489 size_t exit_size;
490 pgd_t *tmp_pg_dir;
491 phys_addr_t phys_hibernate_exit;
492 void __noreturn (*hibernate_exit)(phys_addr_t, phys_addr_t, void *,
493 void *, phys_addr_t, phys_addr_t);
494
495 /*
496 * Restoring the memory image will overwrite the ttbr1 page tables.
497 * Create a second copy of just the linear map, and use this when
498 * restoring.
499 */
500 tmp_pg_dir = (pgd_t *)get_safe_page(GFP_ATOMIC);
501 if (!tmp_pg_dir) {
502 pr_err("Failed to allocate memory for temporary page tables.\n");
503 rc = -ENOMEM;
504 goto out;
505 }
506 rc = copy_page_tables(tmp_pg_dir, PAGE_OFFSET, PAGE_END);
507 if (rc)
508 goto out;
509
510 /*
511 * We need a zero page that is zero before & after resume in order to
512 * to break before make on the ttbr1 page tables.
513 */
514 zero_page = (void *)get_safe_page(GFP_ATOMIC);
515 if (!zero_page) {
516 pr_err("Failed to allocate zero page.\n");
517 rc = -ENOMEM;
518 goto out;
519 }
520
521 /*
522 * Locate the exit code in the bottom-but-one page, so that *NULL
523 * still has disastrous affects.
524 */
525 hibernate_exit = (void *)PAGE_SIZE;
526 exit_size = __hibernate_exit_text_end - __hibernate_exit_text_start;
527 /*
528 * Copy swsusp_arch_suspend_exit() to a safe page. This will generate
529 * a new set of ttbr0 page tables and load them.
530 */
531 rc = create_safe_exec_page(__hibernate_exit_text_start, exit_size,
532 (unsigned long)hibernate_exit,
533 &phys_hibernate_exit,
534 (void *)get_safe_page, GFP_ATOMIC);
535 if (rc) {
536 pr_err("Failed to create safe executable page for hibernate_exit code.\n");
537 goto out;
538 }
539
540 /*
541 * The hibernate exit text contains a set of el2 vectors, that will
542 * be executed at el2 with the mmu off in order to reload hyp-stub.
543 */
544 __flush_dcache_area(hibernate_exit, exit_size);
545
546 /*
547 * KASLR will cause the el2 vectors to be in a different location in
548 * the resumed kernel. Load hibernate's temporary copy into el2.
549 *
550 * We can skip this step if we booted at EL1, or are running with VHE.
551 */
552 if (el2_reset_needed()) {
553 phys_addr_t el2_vectors = phys_hibernate_exit; /* base */
554 el2_vectors += hibernate_el2_vectors -
555 __hibernate_exit_text_start; /* offset */
556
557 __hyp_set_vectors(el2_vectors);
558 }
559
560 hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1,
561 resume_hdr.reenter_kernel, restore_pblist,
562 resume_hdr.__hyp_stub_vectors, virt_to_phys(zero_page));
563
564out:
565 return rc;
566}
567
568int hibernate_resume_nonboot_cpu_disable(void)
569{
570 if (sleep_cpu < 0) {
571 pr_err("Failing to resume from hibernate on an unknown CPU.\n");
572 return -ENODEV;
573 }
574
575 return freeze_secondary_cpus(sleep_cpu);
576}
1// SPDX-License-Identifier: GPL-2.0-only
2/*:
3 * Hibernate support specific for ARM64
4 *
5 * Derived from work on ARM hibernation support by:
6 *
7 * Ubuntu project, hibernation support for mach-dove
8 * Copyright (C) 2010 Nokia Corporation (Hiroshi Doyu)
9 * Copyright (C) 2010 Texas Instruments, Inc. (Teerth Reddy et al.)
10 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
11 */
12#define pr_fmt(x) "hibernate: " x
13#include <linux/cpu.h>
14#include <linux/kvm_host.h>
15#include <linux/pm.h>
16#include <linux/sched.h>
17#include <linux/suspend.h>
18#include <linux/utsname.h>
19
20#include <asm/barrier.h>
21#include <asm/cacheflush.h>
22#include <asm/cputype.h>
23#include <asm/daifflags.h>
24#include <asm/irqflags.h>
25#include <asm/kexec.h>
26#include <asm/memory.h>
27#include <asm/mmu_context.h>
28#include <asm/mte.h>
29#include <asm/sections.h>
30#include <asm/smp.h>
31#include <asm/smp_plat.h>
32#include <asm/suspend.h>
33#include <asm/sysreg.h>
34#include <asm/trans_pgd.h>
35#include <asm/virt.h>
36
37/*
38 * Hibernate core relies on this value being 0 on resume, and marks it
39 * __nosavedata assuming it will keep the resume kernel's '0' value. This
40 * doesn't happen with either KASLR.
41 *
42 * defined as "__visible int in_suspend __nosavedata" in
43 * kernel/power/hibernate.c
44 */
45extern int in_suspend;
46
47/* Do we need to reset el2? */
48#define el2_reset_needed() (is_hyp_nvhe())
49
50/* hyp-stub vectors, used to restore el2 during resume from hibernate. */
51extern char __hyp_stub_vectors[];
52
53/*
54 * The logical cpu number we should resume on, initialised to a non-cpu
55 * number.
56 */
57static int sleep_cpu = -EINVAL;
58
59/*
60 * Values that may not change over hibernate/resume. We put the build number
61 * and date in here so that we guarantee not to resume with a different
62 * kernel.
63 */
64struct arch_hibernate_hdr_invariants {
65 char uts_version[__NEW_UTS_LEN + 1];
66};
67
68/* These values need to be know across a hibernate/restore. */
69static struct arch_hibernate_hdr {
70 struct arch_hibernate_hdr_invariants invariants;
71
72 /* These are needed to find the relocated kernel if built with kaslr */
73 phys_addr_t ttbr1_el1;
74 void (*reenter_kernel)(void);
75
76 /*
77 * We need to know where the __hyp_stub_vectors are after restore to
78 * re-configure el2.
79 */
80 phys_addr_t __hyp_stub_vectors;
81
82 u64 sleep_cpu_mpidr;
83} resume_hdr;
84
85static inline void arch_hdr_invariants(struct arch_hibernate_hdr_invariants *i)
86{
87 memset(i, 0, sizeof(*i));
88 memcpy(i->uts_version, init_utsname()->version, sizeof(i->uts_version));
89}
90
91int pfn_is_nosave(unsigned long pfn)
92{
93 unsigned long nosave_begin_pfn = sym_to_pfn(&__nosave_begin);
94 unsigned long nosave_end_pfn = sym_to_pfn(&__nosave_end - 1);
95
96 return ((pfn >= nosave_begin_pfn) && (pfn <= nosave_end_pfn)) ||
97 crash_is_nosave(pfn);
98}
99
100void notrace save_processor_state(void)
101{
102 WARN_ON(num_online_cpus() != 1);
103}
104
105void notrace restore_processor_state(void)
106{
107}
108
109int arch_hibernation_header_save(void *addr, unsigned int max_size)
110{
111 struct arch_hibernate_hdr *hdr = addr;
112
113 if (max_size < sizeof(*hdr))
114 return -EOVERFLOW;
115
116 arch_hdr_invariants(&hdr->invariants);
117 hdr->ttbr1_el1 = __pa_symbol(swapper_pg_dir);
118 hdr->reenter_kernel = _cpu_resume;
119
120 /* We can't use __hyp_get_vectors() because kvm may still be loaded */
121 if (el2_reset_needed())
122 hdr->__hyp_stub_vectors = __pa_symbol(__hyp_stub_vectors);
123 else
124 hdr->__hyp_stub_vectors = 0;
125
126 /* Save the mpidr of the cpu we called cpu_suspend() on... */
127 if (sleep_cpu < 0) {
128 pr_err("Failing to hibernate on an unknown CPU.\n");
129 return -ENODEV;
130 }
131 hdr->sleep_cpu_mpidr = cpu_logical_map(sleep_cpu);
132 pr_info("Hibernating on CPU %d [mpidr:0x%llx]\n", sleep_cpu,
133 hdr->sleep_cpu_mpidr);
134
135 return 0;
136}
137EXPORT_SYMBOL(arch_hibernation_header_save);
138
139int arch_hibernation_header_restore(void *addr)
140{
141 int ret;
142 struct arch_hibernate_hdr_invariants invariants;
143 struct arch_hibernate_hdr *hdr = addr;
144
145 arch_hdr_invariants(&invariants);
146 if (memcmp(&hdr->invariants, &invariants, sizeof(invariants))) {
147 pr_crit("Hibernate image not generated by this kernel!\n");
148 return -EINVAL;
149 }
150
151 sleep_cpu = get_logical_index(hdr->sleep_cpu_mpidr);
152 pr_info("Hibernated on CPU %d [mpidr:0x%llx]\n", sleep_cpu,
153 hdr->sleep_cpu_mpidr);
154 if (sleep_cpu < 0) {
155 pr_crit("Hibernated on a CPU not known to this kernel!\n");
156 sleep_cpu = -EINVAL;
157 return -EINVAL;
158 }
159
160 ret = bringup_hibernate_cpu(sleep_cpu);
161 if (ret) {
162 sleep_cpu = -EINVAL;
163 return ret;
164 }
165
166 resume_hdr = *hdr;
167
168 return 0;
169}
170EXPORT_SYMBOL(arch_hibernation_header_restore);
171
172static void *hibernate_page_alloc(void *arg)
173{
174 return (void *)get_safe_page((__force gfp_t)(unsigned long)arg);
175}
176
177/*
178 * Copies length bytes, starting at src_start into an new page,
179 * perform cache maintenance, then maps it at the specified address low
180 * address as executable.
181 *
182 * This is used by hibernate to copy the code it needs to execute when
183 * overwriting the kernel text. This function generates a new set of page
184 * tables, which it loads into ttbr0.
185 *
186 * Length is provided as we probably only want 4K of data, even on a 64K
187 * page system.
188 */
189static int create_safe_exec_page(void *src_start, size_t length,
190 phys_addr_t *phys_dst_addr)
191{
192 struct trans_pgd_info trans_info = {
193 .trans_alloc_page = hibernate_page_alloc,
194 .trans_alloc_arg = (__force void *)GFP_ATOMIC,
195 };
196
197 void *page = (void *)get_safe_page(GFP_ATOMIC);
198 phys_addr_t trans_ttbr0;
199 unsigned long t0sz;
200 int rc;
201
202 if (!page)
203 return -ENOMEM;
204
205 memcpy(page, src_start, length);
206 caches_clean_inval_pou((unsigned long)page, (unsigned long)page + length);
207 rc = trans_pgd_idmap_page(&trans_info, &trans_ttbr0, &t0sz, page);
208 if (rc)
209 return rc;
210
211 cpu_install_ttbr0(trans_ttbr0, t0sz);
212 *phys_dst_addr = virt_to_phys(page);
213
214 return 0;
215}
216
217#ifdef CONFIG_ARM64_MTE
218
219static DEFINE_XARRAY(mte_pages);
220
221static int save_tags(struct page *page, unsigned long pfn)
222{
223 void *tag_storage, *ret;
224
225 tag_storage = mte_allocate_tag_storage();
226 if (!tag_storage)
227 return -ENOMEM;
228
229 mte_save_page_tags(page_address(page), tag_storage);
230
231 ret = xa_store(&mte_pages, pfn, tag_storage, GFP_KERNEL);
232 if (WARN(xa_is_err(ret), "Failed to store MTE tags")) {
233 mte_free_tag_storage(tag_storage);
234 return xa_err(ret);
235 } else if (WARN(ret, "swsusp: %s: Duplicate entry", __func__)) {
236 mte_free_tag_storage(ret);
237 }
238
239 return 0;
240}
241
242static void swsusp_mte_free_storage(void)
243{
244 XA_STATE(xa_state, &mte_pages, 0);
245 void *tags;
246
247 xa_lock(&mte_pages);
248 xas_for_each(&xa_state, tags, ULONG_MAX) {
249 mte_free_tag_storage(tags);
250 }
251 xa_unlock(&mte_pages);
252
253 xa_destroy(&mte_pages);
254}
255
256static int swsusp_mte_save_tags(void)
257{
258 struct zone *zone;
259 unsigned long pfn, max_zone_pfn;
260 int ret = 0;
261 int n = 0;
262
263 if (!system_supports_mte())
264 return 0;
265
266 for_each_populated_zone(zone) {
267 max_zone_pfn = zone_end_pfn(zone);
268 for (pfn = zone->zone_start_pfn; pfn < max_zone_pfn; pfn++) {
269 struct page *page = pfn_to_online_page(pfn);
270
271 if (!page)
272 continue;
273
274 if (!page_mte_tagged(page))
275 continue;
276
277 ret = save_tags(page, pfn);
278 if (ret) {
279 swsusp_mte_free_storage();
280 goto out;
281 }
282
283 n++;
284 }
285 }
286 pr_info("Saved %d MTE pages\n", n);
287
288out:
289 return ret;
290}
291
292static void swsusp_mte_restore_tags(void)
293{
294 XA_STATE(xa_state, &mte_pages, 0);
295 int n = 0;
296 void *tags;
297
298 xa_lock(&mte_pages);
299 xas_for_each(&xa_state, tags, ULONG_MAX) {
300 unsigned long pfn = xa_state.xa_index;
301 struct page *page = pfn_to_online_page(pfn);
302
303 mte_restore_page_tags(page_address(page), tags);
304
305 mte_free_tag_storage(tags);
306 n++;
307 }
308 xa_unlock(&mte_pages);
309
310 pr_info("Restored %d MTE pages\n", n);
311
312 xa_destroy(&mte_pages);
313}
314
315#else /* CONFIG_ARM64_MTE */
316
317static int swsusp_mte_save_tags(void)
318{
319 return 0;
320}
321
322static void swsusp_mte_restore_tags(void)
323{
324}
325
326#endif /* CONFIG_ARM64_MTE */
327
328int swsusp_arch_suspend(void)
329{
330 int ret = 0;
331 unsigned long flags;
332 struct sleep_stack_data state;
333
334 if (cpus_are_stuck_in_kernel()) {
335 pr_err("Can't hibernate: no mechanism to offline secondary CPUs.\n");
336 return -EBUSY;
337 }
338
339 flags = local_daif_save();
340
341 if (__cpu_suspend_enter(&state)) {
342 /* make the crash dump kernel image visible/saveable */
343 crash_prepare_suspend();
344
345 ret = swsusp_mte_save_tags();
346 if (ret)
347 return ret;
348
349 sleep_cpu = smp_processor_id();
350 ret = swsusp_save();
351 } else {
352 /* Clean kernel core startup/idle code to PoC*/
353 dcache_clean_inval_poc((unsigned long)__mmuoff_data_start,
354 (unsigned long)__mmuoff_data_end);
355 dcache_clean_inval_poc((unsigned long)__idmap_text_start,
356 (unsigned long)__idmap_text_end);
357
358 /* Clean kvm setup code to PoC? */
359 if (el2_reset_needed()) {
360 dcache_clean_inval_poc(
361 (unsigned long)__hyp_idmap_text_start,
362 (unsigned long)__hyp_idmap_text_end);
363 dcache_clean_inval_poc((unsigned long)__hyp_text_start,
364 (unsigned long)__hyp_text_end);
365 }
366
367 swsusp_mte_restore_tags();
368
369 /* make the crash dump kernel image protected again */
370 crash_post_resume();
371
372 /*
373 * Tell the hibernation core that we've just restored
374 * the memory
375 */
376 in_suspend = 0;
377
378 sleep_cpu = -EINVAL;
379 __cpu_suspend_exit();
380
381 /*
382 * Just in case the boot kernel did turn the SSBD
383 * mitigation off behind our back, let's set the state
384 * to what we expect it to be.
385 */
386 spectre_v4_enable_mitigation(NULL);
387 }
388
389 local_daif_restore(flags);
390
391 return ret;
392}
393
394/*
395 * Setup then Resume from the hibernate image using swsusp_arch_suspend_exit().
396 *
397 * Memory allocated by get_safe_page() will be dealt with by the hibernate code,
398 * we don't need to free it here.
399 */
400int swsusp_arch_resume(void)
401{
402 int rc;
403 void *zero_page;
404 size_t exit_size;
405 pgd_t *tmp_pg_dir;
406 phys_addr_t el2_vectors;
407 void __noreturn (*hibernate_exit)(phys_addr_t, phys_addr_t, void *,
408 void *, phys_addr_t, phys_addr_t);
409 struct trans_pgd_info trans_info = {
410 .trans_alloc_page = hibernate_page_alloc,
411 .trans_alloc_arg = (void *)GFP_ATOMIC,
412 };
413
414 /*
415 * Restoring the memory image will overwrite the ttbr1 page tables.
416 * Create a second copy of just the linear map, and use this when
417 * restoring.
418 */
419 rc = trans_pgd_create_copy(&trans_info, &tmp_pg_dir, PAGE_OFFSET,
420 PAGE_END);
421 if (rc)
422 return rc;
423
424 /*
425 * We need a zero page that is zero before & after resume in order
426 * to break before make on the ttbr1 page tables.
427 */
428 zero_page = (void *)get_safe_page(GFP_ATOMIC);
429 if (!zero_page) {
430 pr_err("Failed to allocate zero page.\n");
431 return -ENOMEM;
432 }
433
434 if (el2_reset_needed()) {
435 rc = trans_pgd_copy_el2_vectors(&trans_info, &el2_vectors);
436 if (rc) {
437 pr_err("Failed to setup el2 vectors\n");
438 return rc;
439 }
440 }
441
442 exit_size = __hibernate_exit_text_end - __hibernate_exit_text_start;
443 /*
444 * Copy swsusp_arch_suspend_exit() to a safe page. This will generate
445 * a new set of ttbr0 page tables and load them.
446 */
447 rc = create_safe_exec_page(__hibernate_exit_text_start, exit_size,
448 (phys_addr_t *)&hibernate_exit);
449 if (rc) {
450 pr_err("Failed to create safe executable page for hibernate_exit code.\n");
451 return rc;
452 }
453
454 /*
455 * KASLR will cause the el2 vectors to be in a different location in
456 * the resumed kernel. Load hibernate's temporary copy into el2.
457 *
458 * We can skip this step if we booted at EL1, or are running with VHE.
459 */
460 if (el2_reset_needed())
461 __hyp_set_vectors(el2_vectors);
462
463 hibernate_exit(virt_to_phys(tmp_pg_dir), resume_hdr.ttbr1_el1,
464 resume_hdr.reenter_kernel, restore_pblist,
465 resume_hdr.__hyp_stub_vectors, virt_to_phys(zero_page));
466
467 return 0;
468}
469
470int hibernate_resume_nonboot_cpu_disable(void)
471{
472 if (sleep_cpu < 0) {
473 pr_err("Failing to resume from hibernate on an unknown CPU.\n");
474 return -ENODEV;
475 }
476
477 return freeze_secondary_cpus(sleep_cpu);
478}