GNU Linux-libre 4.19.286-gnu1
[releases.git] / arch / mips / kvm / tlb.c
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * KVM/MIPS TLB handling, this file is part of the Linux host kernel so that
7  * TLB handlers run from KSEG0
8  *
9  * Copyright (C) 2012  MIPS Technologies, Inc.  All rights reserved.
10  * Authors: Sanjay Lal <sanjayl@kymasys.com>
11  */
12
13 #include <linux/sched.h>
14 #include <linux/smp.h>
15 #include <linux/mm.h>
16 #include <linux/delay.h>
17 #include <linux/export.h>
18 #include <linux/kvm_host.h>
19 #include <linux/srcu.h>
20
21 #include <asm/cpu.h>
22 #include <asm/bootinfo.h>
23 #include <asm/mmu_context.h>
24 #include <asm/pgtable.h>
25 #include <asm/cacheflush.h>
26 #include <asm/tlb.h>
27 #include <asm/tlbdebug.h>
28
29 #undef CONFIG_MIPS_MT
30 #include <asm/r4kcache.h>
31 #define CONFIG_MIPS_MT
32
33 #define KVM_GUEST_PC_TLB    0
34 #define KVM_GUEST_SP_TLB    1
35
36 #ifdef CONFIG_KVM_MIPS_VZ
37 unsigned long GUESTID_MASK;
38 EXPORT_SYMBOL_GPL(GUESTID_MASK);
39 unsigned long GUESTID_FIRST_VERSION;
40 EXPORT_SYMBOL_GPL(GUESTID_FIRST_VERSION);
41 unsigned long GUESTID_VERSION_MASK;
42 EXPORT_SYMBOL_GPL(GUESTID_VERSION_MASK);
43
44 static u32 kvm_mips_get_root_asid(struct kvm_vcpu *vcpu)
45 {
46         struct mm_struct *gpa_mm = &vcpu->kvm->arch.gpa_mm;
47
48         if (cpu_has_guestid)
49                 return 0;
50         else
51                 return cpu_asid(smp_processor_id(), gpa_mm);
52 }
53 #endif
54
55 static u32 kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
56 {
57         struct mm_struct *kern_mm = &vcpu->arch.guest_kernel_mm;
58         int cpu = smp_processor_id();
59
60         return cpu_asid(cpu, kern_mm);
61 }
62
63 static u32 kvm_mips_get_user_asid(struct kvm_vcpu *vcpu)
64 {
65         struct mm_struct *user_mm = &vcpu->arch.guest_user_mm;
66         int cpu = smp_processor_id();
67
68         return cpu_asid(cpu, user_mm);
69 }
70
71 /* Structure defining an tlb entry data set. */
72
73 void kvm_mips_dump_host_tlbs(void)
74 {
75         unsigned long flags;
76
77         local_irq_save(flags);
78
79         kvm_info("HOST TLBs:\n");
80         dump_tlb_regs();
81         pr_info("\n");
82         dump_tlb_all();
83
84         local_irq_restore(flags);
85 }
86 EXPORT_SYMBOL_GPL(kvm_mips_dump_host_tlbs);
87
88 void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu)
89 {
90         struct mips_coproc *cop0 = vcpu->arch.cop0;
91         struct kvm_mips_tlb tlb;
92         int i;
93
94         kvm_info("Guest TLBs:\n");
95         kvm_info("Guest EntryHi: %#lx\n", kvm_read_c0_guest_entryhi(cop0));
96
97         for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
98                 tlb = vcpu->arch.guest_tlb[i];
99                 kvm_info("TLB%c%3d Hi 0x%08lx ",
100                          (tlb.tlb_lo[0] | tlb.tlb_lo[1]) & ENTRYLO_V
101                                                         ? ' ' : '*',
102                          i, tlb.tlb_hi);
103                 kvm_info("Lo0=0x%09llx %c%c attr %lx ",
104                          (u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[0]),
105                          (tlb.tlb_lo[0] & ENTRYLO_D) ? 'D' : ' ',
106                          (tlb.tlb_lo[0] & ENTRYLO_G) ? 'G' : ' ',
107                          (tlb.tlb_lo[0] & ENTRYLO_C) >> ENTRYLO_C_SHIFT);
108                 kvm_info("Lo1=0x%09llx %c%c attr %lx sz=%lx\n",
109                          (u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[1]),
110                          (tlb.tlb_lo[1] & ENTRYLO_D) ? 'D' : ' ',
111                          (tlb.tlb_lo[1] & ENTRYLO_G) ? 'G' : ' ',
112                          (tlb.tlb_lo[1] & ENTRYLO_C) >> ENTRYLO_C_SHIFT,
113                          tlb.tlb_mask);
114         }
115 }
116 EXPORT_SYMBOL_GPL(kvm_mips_dump_guest_tlbs);
117
118 int kvm_mips_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long entryhi)
119 {
120         int i;
121         int index = -1;
122         struct kvm_mips_tlb *tlb = vcpu->arch.guest_tlb;
123
124         for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
125                 if (TLB_HI_VPN2_HIT(tlb[i], entryhi) &&
126                     TLB_HI_ASID_HIT(tlb[i], entryhi)) {
127                         index = i;
128                         break;
129                 }
130         }
131
132         kvm_debug("%s: entryhi: %#lx, index: %d lo0: %#lx, lo1: %#lx\n",
133                   __func__, entryhi, index, tlb[i].tlb_lo[0], tlb[i].tlb_lo[1]);
134
135         return index;
136 }
137 EXPORT_SYMBOL_GPL(kvm_mips_guest_tlb_lookup);
138
139 static int _kvm_mips_host_tlb_inv(unsigned long entryhi)
140 {
141         int idx;
142
143         write_c0_entryhi(entryhi);
144         mtc0_tlbw_hazard();
145
146         tlb_probe();
147         tlb_probe_hazard();
148         idx = read_c0_index();
149
150         if (idx >= current_cpu_data.tlbsize)
151                 BUG();
152
153         if (idx >= 0) {
154                 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
155                 write_c0_entrylo0(0);
156                 write_c0_entrylo1(0);
157                 mtc0_tlbw_hazard();
158
159                 tlb_write_indexed();
160                 tlbw_use_hazard();
161         }
162
163         return idx;
164 }
165
166 int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va,
167                           bool user, bool kernel)
168 {
169         /*
170          * Initialize idx_user and idx_kernel to workaround bogus
171          * maybe-initialized warning when using GCC 6.
172          */
173         int idx_user = 0, idx_kernel = 0;
174         unsigned long flags, old_entryhi;
175
176         local_irq_save(flags);
177
178         old_entryhi = read_c0_entryhi();
179
180         if (user)
181                 idx_user = _kvm_mips_host_tlb_inv((va & VPN2_MASK) |
182                                                   kvm_mips_get_user_asid(vcpu));
183         if (kernel)
184                 idx_kernel = _kvm_mips_host_tlb_inv((va & VPN2_MASK) |
185                                                 kvm_mips_get_kernel_asid(vcpu));
186
187         write_c0_entryhi(old_entryhi);
188         mtc0_tlbw_hazard();
189
190         local_irq_restore(flags);
191
192         /*
193          * We don't want to get reserved instruction exceptions for missing tlb
194          * entries.
195          */
196         if (cpu_has_vtag_icache)
197                 flush_icache_all();
198
199         if (user && idx_user >= 0)
200                 kvm_debug("%s: Invalidated guest user entryhi %#lx @ idx %d\n",
201                           __func__, (va & VPN2_MASK) |
202                                     kvm_mips_get_user_asid(vcpu), idx_user);
203         if (kernel && idx_kernel >= 0)
204                 kvm_debug("%s: Invalidated guest kernel entryhi %#lx @ idx %d\n",
205                           __func__, (va & VPN2_MASK) |
206                                     kvm_mips_get_kernel_asid(vcpu), idx_kernel);
207
208         return 0;
209 }
210 EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_inv);
211
212 #ifdef CONFIG_KVM_MIPS_VZ
213
214 /* GuestID management */
215
216 /**
217  * clear_root_gid() - Set GuestCtl1.RID for normal root operation.
218  */
219 static inline void clear_root_gid(void)
220 {
221         if (cpu_has_guestid) {
222                 clear_c0_guestctl1(MIPS_GCTL1_RID);
223                 mtc0_tlbw_hazard();
224         }
225 }
226
227 /**
228  * set_root_gid_to_guest_gid() - Set GuestCtl1.RID to match GuestCtl1.ID.
229  *
230  * Sets the root GuestID to match the current guest GuestID, for TLB operation
231  * on the GPA->RPA mappings in the root TLB.
232  *
233  * The caller must be sure to disable HTW while the root GID is set, and
234  * possibly longer if TLB registers are modified.
235  */
236 static inline void set_root_gid_to_guest_gid(void)
237 {
238         unsigned int guestctl1;
239
240         if (cpu_has_guestid) {
241                 back_to_back_c0_hazard();
242                 guestctl1 = read_c0_guestctl1();
243                 guestctl1 = (guestctl1 & ~MIPS_GCTL1_RID) |
244                         ((guestctl1 & MIPS_GCTL1_ID) >> MIPS_GCTL1_ID_SHIFT)
245                                                      << MIPS_GCTL1_RID_SHIFT;
246                 write_c0_guestctl1(guestctl1);
247                 mtc0_tlbw_hazard();
248         }
249 }
250
251 int kvm_vz_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va)
252 {
253         int idx;
254         unsigned long flags, old_entryhi;
255
256         local_irq_save(flags);
257         htw_stop();
258
259         /* Set root GuestID for root probe and write of guest TLB entry */
260         set_root_gid_to_guest_gid();
261
262         old_entryhi = read_c0_entryhi();
263
264         idx = _kvm_mips_host_tlb_inv((va & VPN2_MASK) |
265                                      kvm_mips_get_root_asid(vcpu));
266
267         write_c0_entryhi(old_entryhi);
268         clear_root_gid();
269         mtc0_tlbw_hazard();
270
271         htw_start();
272         local_irq_restore(flags);
273
274         /*
275          * We don't want to get reserved instruction exceptions for missing tlb
276          * entries.
277          */
278         if (cpu_has_vtag_icache)
279                 flush_icache_all();
280
281         if (idx > 0)
282                 kvm_debug("%s: Invalidated root entryhi %#lx @ idx %d\n",
283                           __func__, (va & VPN2_MASK) |
284                                     kvm_mips_get_root_asid(vcpu), idx);
285
286         return 0;
287 }
288 EXPORT_SYMBOL_GPL(kvm_vz_host_tlb_inv);
289
290 /**
291  * kvm_vz_guest_tlb_lookup() - Lookup a guest VZ TLB mapping.
292  * @vcpu:       KVM VCPU pointer.
293  * @gpa:        Guest virtual address in a TLB mapped guest segment.
294  * @gpa:        Ponter to output guest physical address it maps to.
295  *
296  * Converts a guest virtual address in a guest TLB mapped segment to a guest
297  * physical address, by probing the guest TLB.
298  *
299  * Returns:     0 if guest TLB mapping exists for @gva. *@gpa will have been
300  *              written.
301  *              -EFAULT if no guest TLB mapping exists for @gva. *@gpa may not
302  *              have been written.
303  */
304 int kvm_vz_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long gva,
305                             unsigned long *gpa)
306 {
307         unsigned long o_entryhi, o_entrylo[2], o_pagemask;
308         unsigned int o_index;
309         unsigned long entrylo[2], pagemask, pagemaskbit, pa;
310         unsigned long flags;
311         int index;
312
313         /* Probe the guest TLB for a mapping */
314         local_irq_save(flags);
315         /* Set root GuestID for root probe of guest TLB entry */
316         htw_stop();
317         set_root_gid_to_guest_gid();
318
319         o_entryhi = read_gc0_entryhi();
320         o_index = read_gc0_index();
321
322         write_gc0_entryhi((o_entryhi & 0x3ff) | (gva & ~0xfffl));
323         mtc0_tlbw_hazard();
324         guest_tlb_probe();
325         tlb_probe_hazard();
326
327         index = read_gc0_index();
328         if (index < 0) {
329                 /* No match, fail */
330                 write_gc0_entryhi(o_entryhi);
331                 write_gc0_index(o_index);
332
333                 clear_root_gid();
334                 htw_start();
335                 local_irq_restore(flags);
336                 return -EFAULT;
337         }
338
339         /* Match! read the TLB entry */
340         o_entrylo[0] = read_gc0_entrylo0();
341         o_entrylo[1] = read_gc0_entrylo1();
342         o_pagemask = read_gc0_pagemask();
343
344         mtc0_tlbr_hazard();
345         guest_tlb_read();
346         tlb_read_hazard();
347
348         entrylo[0] = read_gc0_entrylo0();
349         entrylo[1] = read_gc0_entrylo1();
350         pagemask = ~read_gc0_pagemask() & ~0x1fffl;
351
352         write_gc0_entryhi(o_entryhi);
353         write_gc0_index(o_index);
354         write_gc0_entrylo0(o_entrylo[0]);
355         write_gc0_entrylo1(o_entrylo[1]);
356         write_gc0_pagemask(o_pagemask);
357
358         clear_root_gid();
359         htw_start();
360         local_irq_restore(flags);
361
362         /* Select one of the EntryLo values and interpret the GPA */
363         pagemaskbit = (pagemask ^ (pagemask & (pagemask - 1))) >> 1;
364         pa = entrylo[!!(gva & pagemaskbit)];
365
366         /*
367          * TLB entry may have become invalid since TLB probe if physical FTLB
368          * entries are shared between threads (e.g. I6400).
369          */
370         if (!(pa & ENTRYLO_V))
371                 return -EFAULT;
372
373         /*
374          * Note, this doesn't take guest MIPS32 XPA into account, where PFN is
375          * split with XI/RI in the middle.
376          */
377         pa = (pa << 6) & ~0xfffl;
378         pa |= gva & ~(pagemask | pagemaskbit);
379
380         *gpa = pa;
381         return 0;
382 }
383 EXPORT_SYMBOL_GPL(kvm_vz_guest_tlb_lookup);
384
385 /**
386  * kvm_vz_local_flush_roottlb_all_guests() - Flush all root TLB entries for
387  * guests.
388  *
389  * Invalidate all entries in root tlb which are GPA mappings.
390  */
391 void kvm_vz_local_flush_roottlb_all_guests(void)
392 {
393         unsigned long flags;
394         unsigned long old_entryhi, old_pagemask, old_guestctl1;
395         int entry;
396
397         if (WARN_ON(!cpu_has_guestid))
398                 return;
399
400         local_irq_save(flags);
401         htw_stop();
402
403         /* TLBR may clobber EntryHi.ASID, PageMask, and GuestCtl1.RID */
404         old_entryhi = read_c0_entryhi();
405         old_pagemask = read_c0_pagemask();
406         old_guestctl1 = read_c0_guestctl1();
407
408         /*
409          * Invalidate guest entries in root TLB while leaving root entries
410          * intact when possible.
411          */
412         for (entry = 0; entry < current_cpu_data.tlbsize; entry++) {
413                 write_c0_index(entry);
414                 mtc0_tlbw_hazard();
415                 tlb_read();
416                 tlb_read_hazard();
417
418                 /* Don't invalidate non-guest (RVA) mappings in the root TLB */
419                 if (!(read_c0_guestctl1() & MIPS_GCTL1_RID))
420                         continue;
421
422                 /* Make sure all entries differ. */
423                 write_c0_entryhi(UNIQUE_ENTRYHI(entry));
424                 write_c0_entrylo0(0);
425                 write_c0_entrylo1(0);
426                 write_c0_guestctl1(0);
427                 mtc0_tlbw_hazard();
428                 tlb_write_indexed();
429         }
430
431         write_c0_entryhi(old_entryhi);
432         write_c0_pagemask(old_pagemask);
433         write_c0_guestctl1(old_guestctl1);
434         tlbw_use_hazard();
435
436         htw_start();
437         local_irq_restore(flags);
438 }
439 EXPORT_SYMBOL_GPL(kvm_vz_local_flush_roottlb_all_guests);
440
441 /**
442  * kvm_vz_local_flush_guesttlb_all() - Flush all guest TLB entries.
443  *
444  * Invalidate all entries in guest tlb irrespective of guestid.
445  */
446 void kvm_vz_local_flush_guesttlb_all(void)
447 {
448         unsigned long flags;
449         unsigned long old_index;
450         unsigned long old_entryhi;
451         unsigned long old_entrylo[2];
452         unsigned long old_pagemask;
453         int entry;
454         u64 cvmmemctl2 = 0;
455
456         local_irq_save(flags);
457
458         /* Preserve all clobbered guest registers */
459         old_index = read_gc0_index();
460         old_entryhi = read_gc0_entryhi();
461         old_entrylo[0] = read_gc0_entrylo0();
462         old_entrylo[1] = read_gc0_entrylo1();
463         old_pagemask = read_gc0_pagemask();
464
465         switch (current_cpu_type()) {
466         case CPU_CAVIUM_OCTEON3:
467                 /* Inhibit machine check due to multiple matching TLB entries */
468                 cvmmemctl2 = read_c0_cvmmemctl2();
469                 cvmmemctl2 |= CVMMEMCTL2_INHIBITTS;
470                 write_c0_cvmmemctl2(cvmmemctl2);
471                 break;
472         };
473
474         /* Invalidate guest entries in guest TLB */
475         write_gc0_entrylo0(0);
476         write_gc0_entrylo1(0);
477         write_gc0_pagemask(0);
478         for (entry = 0; entry < current_cpu_data.guest.tlbsize; entry++) {
479                 /* Make sure all entries differ. */
480                 write_gc0_index(entry);
481                 write_gc0_entryhi(UNIQUE_GUEST_ENTRYHI(entry));
482                 mtc0_tlbw_hazard();
483                 guest_tlb_write_indexed();
484         }
485
486         if (cvmmemctl2) {
487                 cvmmemctl2 &= ~CVMMEMCTL2_INHIBITTS;
488                 write_c0_cvmmemctl2(cvmmemctl2);
489         };
490
491         write_gc0_index(old_index);
492         write_gc0_entryhi(old_entryhi);
493         write_gc0_entrylo0(old_entrylo[0]);
494         write_gc0_entrylo1(old_entrylo[1]);
495         write_gc0_pagemask(old_pagemask);
496         tlbw_use_hazard();
497
498         local_irq_restore(flags);
499 }
500 EXPORT_SYMBOL_GPL(kvm_vz_local_flush_guesttlb_all);
501
502 /**
503  * kvm_vz_save_guesttlb() - Save a range of guest TLB entries.
504  * @buf:        Buffer to write TLB entries into.
505  * @index:      Start index.
506  * @count:      Number of entries to save.
507  *
508  * Save a range of guest TLB entries. The caller must ensure interrupts are
509  * disabled.
510  */
511 void kvm_vz_save_guesttlb(struct kvm_mips_tlb *buf, unsigned int index,
512                           unsigned int count)
513 {
514         unsigned int end = index + count;
515         unsigned long old_entryhi, old_entrylo0, old_entrylo1, old_pagemask;
516         unsigned int guestctl1 = 0;
517         int old_index, i;
518
519         /* Save registers we're about to clobber */
520         old_index = read_gc0_index();
521         old_entryhi = read_gc0_entryhi();
522         old_entrylo0 = read_gc0_entrylo0();
523         old_entrylo1 = read_gc0_entrylo1();
524         old_pagemask = read_gc0_pagemask();
525
526         /* Set root GuestID for root probe */
527         htw_stop();
528         set_root_gid_to_guest_gid();
529         if (cpu_has_guestid)
530                 guestctl1 = read_c0_guestctl1();
531
532         /* Read each entry from guest TLB */
533         for (i = index; i < end; ++i, ++buf) {
534                 write_gc0_index(i);
535
536                 mtc0_tlbr_hazard();
537                 guest_tlb_read();
538                 tlb_read_hazard();
539
540                 if (cpu_has_guestid &&
541                     (read_c0_guestctl1() ^ guestctl1) & MIPS_GCTL1_RID) {
542                         /* Entry invalid or belongs to another guest */
543                         buf->tlb_hi = UNIQUE_GUEST_ENTRYHI(i);
544                         buf->tlb_lo[0] = 0;
545                         buf->tlb_lo[1] = 0;
546                         buf->tlb_mask = 0;
547                 } else {
548                         /* Entry belongs to the right guest */
549                         buf->tlb_hi = read_gc0_entryhi();
550                         buf->tlb_lo[0] = read_gc0_entrylo0();
551                         buf->tlb_lo[1] = read_gc0_entrylo1();
552                         buf->tlb_mask = read_gc0_pagemask();
553                 }
554         }
555
556         /* Clear root GuestID again */
557         clear_root_gid();
558         htw_start();
559
560         /* Restore clobbered registers */
561         write_gc0_index(old_index);
562         write_gc0_entryhi(old_entryhi);
563         write_gc0_entrylo0(old_entrylo0);
564         write_gc0_entrylo1(old_entrylo1);
565         write_gc0_pagemask(old_pagemask);
566
567         tlbw_use_hazard();
568 }
569 EXPORT_SYMBOL_GPL(kvm_vz_save_guesttlb);
570
571 /**
572  * kvm_vz_load_guesttlb() - Save a range of guest TLB entries.
573  * @buf:        Buffer to read TLB entries from.
574  * @index:      Start index.
575  * @count:      Number of entries to load.
576  *
577  * Load a range of guest TLB entries. The caller must ensure interrupts are
578  * disabled.
579  */
580 void kvm_vz_load_guesttlb(const struct kvm_mips_tlb *buf, unsigned int index,
581                           unsigned int count)
582 {
583         unsigned int end = index + count;
584         unsigned long old_entryhi, old_entrylo0, old_entrylo1, old_pagemask;
585         int old_index, i;
586
587         /* Save registers we're about to clobber */
588         old_index = read_gc0_index();
589         old_entryhi = read_gc0_entryhi();
590         old_entrylo0 = read_gc0_entrylo0();
591         old_entrylo1 = read_gc0_entrylo1();
592         old_pagemask = read_gc0_pagemask();
593
594         /* Set root GuestID for root probe */
595         htw_stop();
596         set_root_gid_to_guest_gid();
597
598         /* Write each entry to guest TLB */
599         for (i = index; i < end; ++i, ++buf) {
600                 write_gc0_index(i);
601                 write_gc0_entryhi(buf->tlb_hi);
602                 write_gc0_entrylo0(buf->tlb_lo[0]);
603                 write_gc0_entrylo1(buf->tlb_lo[1]);
604                 write_gc0_pagemask(buf->tlb_mask);
605
606                 mtc0_tlbw_hazard();
607                 guest_tlb_write_indexed();
608         }
609
610         /* Clear root GuestID again */
611         clear_root_gid();
612         htw_start();
613
614         /* Restore clobbered registers */
615         write_gc0_index(old_index);
616         write_gc0_entryhi(old_entryhi);
617         write_gc0_entrylo0(old_entrylo0);
618         write_gc0_entrylo1(old_entrylo1);
619         write_gc0_pagemask(old_pagemask);
620
621         tlbw_use_hazard();
622 }
623 EXPORT_SYMBOL_GPL(kvm_vz_load_guesttlb);
624
625 #endif
626
627 /**
628  * kvm_mips_suspend_mm() - Suspend the active mm.
629  * @cpu         The CPU we're running on.
630  *
631  * Suspend the active_mm, ready for a switch to a KVM guest virtual address
632  * space. This is left active for the duration of guest context, including time
633  * with interrupts enabled, so we need to be careful not to confuse e.g. cache
634  * management IPIs.
635  *
636  * kvm_mips_resume_mm() should be called before context switching to a different
637  * process so we don't need to worry about reference counting.
638  *
639  * This needs to be in static kernel code to avoid exporting init_mm.
640  */
641 void kvm_mips_suspend_mm(int cpu)
642 {
643         cpumask_clear_cpu(cpu, mm_cpumask(current->active_mm));
644         current->active_mm = &init_mm;
645 }
646 EXPORT_SYMBOL_GPL(kvm_mips_suspend_mm);
647
648 /**
649  * kvm_mips_resume_mm() - Resume the current process mm.
650  * @cpu         The CPU we're running on.
651  *
652  * Resume the mm of the current process, after a switch back from a KVM guest
653  * virtual address space (see kvm_mips_suspend_mm()).
654  */
655 void kvm_mips_resume_mm(int cpu)
656 {
657         cpumask_set_cpu(cpu, mm_cpumask(current->mm));
658         current->active_mm = current->mm;
659 }
660 EXPORT_SYMBOL_GPL(kvm_mips_resume_mm);