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/mipsregs.h>
24 #include <asm/mmu_context.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 
kvm_mips_get_root_asid(struct kvm_vcpu * vcpu)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 
kvm_mips_get_kernel_asid(struct kvm_vcpu * vcpu)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 
kvm_mips_get_user_asid(struct kvm_vcpu * vcpu)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 
kvm_mips_dump_host_tlbs(void)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 
kvm_mips_dump_guest_tlbs(struct kvm_vcpu * vcpu)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 
kvm_mips_guest_tlb_lookup(struct kvm_vcpu * vcpu,unsigned long entryhi)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 
_kvm_mips_host_tlb_inv(unsigned long entryhi)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 
kvm_mips_host_tlb_inv(struct kvm_vcpu * vcpu,unsigned long va,bool user,bool kernel)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  */
clear_root_gid(void)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  */
set_root_gid_to_guest_gid(void)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 
kvm_vz_host_tlb_inv(struct kvm_vcpu * vcpu,unsigned long va)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  */
kvm_vz_guest_tlb_lookup(struct kvm_vcpu * vcpu,unsigned long gva,unsigned long * gpa)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  */
kvm_vz_local_flush_roottlb_all_guests(void)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  */
kvm_vz_local_flush_guesttlb_all(void)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  */
kvm_vz_save_guesttlb(struct kvm_mips_tlb * buf,unsigned int index,unsigned int count)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  */
kvm_vz_load_guesttlb(const struct kvm_mips_tlb * buf,unsigned int index,unsigned int count)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 #ifdef CONFIG_CPU_LOONGSON64
kvm_loongson_clear_guest_vtlb(void)626 void kvm_loongson_clear_guest_vtlb(void)
627 {
628 	int idx = read_gc0_index();
629 
630 	/* Set root GuestID for root probe and write of guest TLB entry */
631 	set_root_gid_to_guest_gid();
632 
633 	write_gc0_index(0);
634 	guest_tlbinvf();
635 	write_gc0_index(idx);
636 
637 	clear_root_gid();
638 	set_c0_diag(LOONGSON_DIAG_ITLB | LOONGSON_DIAG_DTLB);
639 }
640 EXPORT_SYMBOL_GPL(kvm_loongson_clear_guest_vtlb);
641 
kvm_loongson_clear_guest_ftlb(void)642 void kvm_loongson_clear_guest_ftlb(void)
643 {
644 	int i;
645 	int idx = read_gc0_index();
646 
647 	/* Set root GuestID for root probe and write of guest TLB entry */
648 	set_root_gid_to_guest_gid();
649 
650 	for (i = current_cpu_data.tlbsizevtlb;
651 	     i < (current_cpu_data.tlbsizevtlb +
652 		     current_cpu_data.tlbsizeftlbsets);
653 	     i++) {
654 		write_gc0_index(i);
655 		guest_tlbinvf();
656 	}
657 	write_gc0_index(idx);
658 
659 	clear_root_gid();
660 	set_c0_diag(LOONGSON_DIAG_ITLB | LOONGSON_DIAG_DTLB);
661 }
662 EXPORT_SYMBOL_GPL(kvm_loongson_clear_guest_ftlb);
663 #endif
664 
665 #endif
666 
667 /**
668  * kvm_mips_suspend_mm() - Suspend the active mm.
669  * @cpu		The CPU we're running on.
670  *
671  * Suspend the active_mm, ready for a switch to a KVM guest virtual address
672  * space. This is left active for the duration of guest context, including time
673  * with interrupts enabled, so we need to be careful not to confuse e.g. cache
674  * management IPIs.
675  *
676  * kvm_mips_resume_mm() should be called before context switching to a different
677  * process so we don't need to worry about reference counting.
678  *
679  * This needs to be in static kernel code to avoid exporting init_mm.
680  */
kvm_mips_suspend_mm(int cpu)681 void kvm_mips_suspend_mm(int cpu)
682 {
683 	cpumask_clear_cpu(cpu, mm_cpumask(current->active_mm));
684 	current->active_mm = &init_mm;
685 }
686 EXPORT_SYMBOL_GPL(kvm_mips_suspend_mm);
687 
688 /**
689  * kvm_mips_resume_mm() - Resume the current process mm.
690  * @cpu		The CPU we're running on.
691  *
692  * Resume the mm of the current process, after a switch back from a KVM guest
693  * virtual address space (see kvm_mips_suspend_mm()).
694  */
kvm_mips_resume_mm(int cpu)695 void kvm_mips_resume_mm(int cpu)
696 {
697 	cpumask_set_cpu(cpu, mm_cpumask(current->mm));
698 	current->active_mm = current->mm;
699 }
700 EXPORT_SYMBOL_GPL(kvm_mips_resume_mm);
701