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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
36atomic_t kvm_mips_instance;
37EXPORT_SYMBOL_GPL(kvm_mips_instance);
38
39static u32 kvm_mips_get_kernel_asid(struct kvm_vcpu *vcpu)
40{
41 int cpu = smp_processor_id();
42
43 return vcpu->arch.guest_kernel_asid[cpu] &
44 cpu_asid_mask(&cpu_data[cpu]);
45}
46
47static u32 kvm_mips_get_user_asid(struct kvm_vcpu *vcpu)
48{
49 int cpu = smp_processor_id();
50
51 return vcpu->arch.guest_user_asid[cpu] &
52 cpu_asid_mask(&cpu_data[cpu]);
53}
54
55inline u32 kvm_mips_get_commpage_asid(struct kvm_vcpu *vcpu)
56{
57 return vcpu->kvm->arch.commpage_tlb;
58}
59
60/* Structure defining an tlb entry data set. */
61
62void kvm_mips_dump_host_tlbs(void)
63{
64 unsigned long flags;
65
66 local_irq_save(flags);
67
68 kvm_info("HOST TLBs:\n");
69 dump_tlb_regs();
70 pr_info("\n");
71 dump_tlb_all();
72
73 local_irq_restore(flags);
74}
75EXPORT_SYMBOL_GPL(kvm_mips_dump_host_tlbs);
76
77void kvm_mips_dump_guest_tlbs(struct kvm_vcpu *vcpu)
78{
79 struct mips_coproc *cop0 = vcpu->arch.cop0;
80 struct kvm_mips_tlb tlb;
81 int i;
82
83 kvm_info("Guest TLBs:\n");
84 kvm_info("Guest EntryHi: %#lx\n", kvm_read_c0_guest_entryhi(cop0));
85
86 for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
87 tlb = vcpu->arch.guest_tlb[i];
88 kvm_info("TLB%c%3d Hi 0x%08lx ",
89 (tlb.tlb_lo[0] | tlb.tlb_lo[1]) & ENTRYLO_V
90 ? ' ' : '*',
91 i, tlb.tlb_hi);
92 kvm_info("Lo0=0x%09llx %c%c attr %lx ",
93 (u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[0]),
94 (tlb.tlb_lo[0] & ENTRYLO_D) ? 'D' : ' ',
95 (tlb.tlb_lo[0] & ENTRYLO_G) ? 'G' : ' ',
96 (tlb.tlb_lo[0] & ENTRYLO_C) >> ENTRYLO_C_SHIFT);
97 kvm_info("Lo1=0x%09llx %c%c attr %lx sz=%lx\n",
98 (u64) mips3_tlbpfn_to_paddr(tlb.tlb_lo[1]),
99 (tlb.tlb_lo[1] & ENTRYLO_D) ? 'D' : ' ',
100 (tlb.tlb_lo[1] & ENTRYLO_G) ? 'G' : ' ',
101 (tlb.tlb_lo[1] & ENTRYLO_C) >> ENTRYLO_C_SHIFT,
102 tlb.tlb_mask);
103 }
104}
105EXPORT_SYMBOL_GPL(kvm_mips_dump_guest_tlbs);
106
107/* XXXKYMA: Must be called with interrupts disabled */
108/* set flush_dcache_mask == 0 if no dcache flush required */
109int kvm_mips_host_tlb_write(struct kvm_vcpu *vcpu, unsigned long entryhi,
110 unsigned long entrylo0, unsigned long entrylo1,
111 int flush_dcache_mask)
112{
113 unsigned long flags;
114 unsigned long old_entryhi;
115 int idx;
116
117 local_irq_save(flags);
118
119 old_entryhi = read_c0_entryhi();
120 write_c0_entryhi(entryhi);
121 mtc0_tlbw_hazard();
122
123 tlb_probe();
124 tlb_probe_hazard();
125 idx = read_c0_index();
126
127 if (idx > current_cpu_data.tlbsize) {
128 kvm_err("%s: Invalid Index: %d\n", __func__, idx);
129 kvm_mips_dump_host_tlbs();
130 local_irq_restore(flags);
131 return -1;
132 }
133
134 write_c0_entrylo0(entrylo0);
135 write_c0_entrylo1(entrylo1);
136 mtc0_tlbw_hazard();
137
138 if (idx < 0)
139 tlb_write_random();
140 else
141 tlb_write_indexed();
142 tlbw_use_hazard();
143
144 kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0(R): 0x%08lx, entrylo1(R): 0x%08lx\n",
145 vcpu->arch.pc, idx, read_c0_entryhi(),
146 read_c0_entrylo0(), read_c0_entrylo1());
147
148 /* Flush D-cache */
149 if (flush_dcache_mask) {
150 if (entrylo0 & ENTRYLO_V) {
151 ++vcpu->stat.flush_dcache_exits;
152 flush_data_cache_page((entryhi & VPN2_MASK) &
153 ~flush_dcache_mask);
154 }
155 if (entrylo1 & ENTRYLO_V) {
156 ++vcpu->stat.flush_dcache_exits;
157 flush_data_cache_page(((entryhi & VPN2_MASK) &
158 ~flush_dcache_mask) |
159 (0x1 << PAGE_SHIFT));
160 }
161 }
162
163 /* Restore old ASID */
164 write_c0_entryhi(old_entryhi);
165 mtc0_tlbw_hazard();
166 local_irq_restore(flags);
167 return 0;
168}
169EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_write);
170
171int kvm_mips_handle_commpage_tlb_fault(unsigned long badvaddr,
172 struct kvm_vcpu *vcpu)
173{
174 kvm_pfn_t pfn;
175 unsigned long flags, old_entryhi = 0, vaddr = 0;
176 unsigned long entrylo[2] = { 0, 0 };
177 unsigned int pair_idx;
178
179 pfn = PFN_DOWN(virt_to_phys(vcpu->arch.kseg0_commpage));
180 pair_idx = (badvaddr >> PAGE_SHIFT) & 1;
181 entrylo[pair_idx] = mips3_paddr_to_tlbpfn(pfn << PAGE_SHIFT) |
182 ((_page_cachable_default >> _CACHE_SHIFT) << ENTRYLO_C_SHIFT) |
183 ENTRYLO_D | ENTRYLO_V;
184
185 local_irq_save(flags);
186
187 old_entryhi = read_c0_entryhi();
188 vaddr = badvaddr & (PAGE_MASK << 1);
189 write_c0_entryhi(vaddr | kvm_mips_get_kernel_asid(vcpu));
190 write_c0_entrylo0(entrylo[0]);
191 write_c0_entrylo1(entrylo[1]);
192 write_c0_index(kvm_mips_get_commpage_asid(vcpu));
193 mtc0_tlbw_hazard();
194 tlb_write_indexed();
195 tlbw_use_hazard();
196
197 kvm_debug("@ %#lx idx: %2d [entryhi(R): %#lx] entrylo0 (R): 0x%08lx, entrylo1(R): 0x%08lx\n",
198 vcpu->arch.pc, read_c0_index(), read_c0_entryhi(),
199 read_c0_entrylo0(), read_c0_entrylo1());
200
201 /* Restore old ASID */
202 write_c0_entryhi(old_entryhi);
203 mtc0_tlbw_hazard();
204 local_irq_restore(flags);
205
206 return 0;
207}
208EXPORT_SYMBOL_GPL(kvm_mips_handle_commpage_tlb_fault);
209
210int kvm_mips_guest_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long entryhi)
211{
212 int i;
213 int index = -1;
214 struct kvm_mips_tlb *tlb = vcpu->arch.guest_tlb;
215
216 for (i = 0; i < KVM_MIPS_GUEST_TLB_SIZE; i++) {
217 if (TLB_HI_VPN2_HIT(tlb[i], entryhi) &&
218 TLB_HI_ASID_HIT(tlb[i], entryhi)) {
219 index = i;
220 break;
221 }
222 }
223
224 kvm_debug("%s: entryhi: %#lx, index: %d lo0: %#lx, lo1: %#lx\n",
225 __func__, entryhi, index, tlb[i].tlb_lo[0], tlb[i].tlb_lo[1]);
226
227 return index;
228}
229EXPORT_SYMBOL_GPL(kvm_mips_guest_tlb_lookup);
230
231int kvm_mips_host_tlb_lookup(struct kvm_vcpu *vcpu, unsigned long vaddr)
232{
233 unsigned long old_entryhi, flags;
234 int idx;
235
236 local_irq_save(flags);
237
238 old_entryhi = read_c0_entryhi();
239
240 if (KVM_GUEST_KERNEL_MODE(vcpu))
241 write_c0_entryhi((vaddr & VPN2_MASK) |
242 kvm_mips_get_kernel_asid(vcpu));
243 else {
244 write_c0_entryhi((vaddr & VPN2_MASK) |
245 kvm_mips_get_user_asid(vcpu));
246 }
247
248 mtc0_tlbw_hazard();
249
250 tlb_probe();
251 tlb_probe_hazard();
252 idx = read_c0_index();
253
254 /* Restore old ASID */
255 write_c0_entryhi(old_entryhi);
256 mtc0_tlbw_hazard();
257
258 local_irq_restore(flags);
259
260 kvm_debug("Host TLB lookup, %#lx, idx: %2d\n", vaddr, idx);
261
262 return idx;
263}
264EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_lookup);
265
266int kvm_mips_host_tlb_inv(struct kvm_vcpu *vcpu, unsigned long va)
267{
268 int idx;
269 unsigned long flags, old_entryhi;
270
271 local_irq_save(flags);
272
273 old_entryhi = read_c0_entryhi();
274
275 write_c0_entryhi((va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu));
276 mtc0_tlbw_hazard();
277
278 tlb_probe();
279 tlb_probe_hazard();
280 idx = read_c0_index();
281
282 if (idx >= current_cpu_data.tlbsize)
283 BUG();
284
285 if (idx > 0) {
286 write_c0_entryhi(UNIQUE_ENTRYHI(idx));
287 write_c0_entrylo0(0);
288 write_c0_entrylo1(0);
289 mtc0_tlbw_hazard();
290
291 tlb_write_indexed();
292 tlbw_use_hazard();
293 }
294
295 write_c0_entryhi(old_entryhi);
296 mtc0_tlbw_hazard();
297
298 local_irq_restore(flags);
299
300 if (idx > 0)
301 kvm_debug("%s: Invalidated entryhi %#lx @ idx %d\n", __func__,
302 (va & VPN2_MASK) | kvm_mips_get_user_asid(vcpu), idx);
303
304 return 0;
305}
306EXPORT_SYMBOL_GPL(kvm_mips_host_tlb_inv);
307
308void kvm_mips_flush_host_tlb(int skip_kseg0)
309{
310 unsigned long flags;
311 unsigned long old_entryhi, entryhi;
312 unsigned long old_pagemask;
313 int entry = 0;
314 int maxentry = current_cpu_data.tlbsize;
315
316 local_irq_save(flags);
317
318 old_entryhi = read_c0_entryhi();
319 old_pagemask = read_c0_pagemask();
320
321 /* Blast 'em all away. */
322 for (entry = 0; entry < maxentry; entry++) {
323 write_c0_index(entry);
324
325 if (skip_kseg0) {
326 mtc0_tlbr_hazard();
327 tlb_read();
328 tlb_read_hazard();
329
330 entryhi = read_c0_entryhi();
331
332 /* Don't blow away guest kernel entries */
333 if (KVM_GUEST_KSEGX(entryhi) == KVM_GUEST_KSEG0)
334 continue;
335
336 write_c0_pagemask(old_pagemask);
337 }
338
339 /* Make sure all entries differ. */
340 write_c0_entryhi(UNIQUE_ENTRYHI(entry));
341 write_c0_entrylo0(0);
342 write_c0_entrylo1(0);
343 mtc0_tlbw_hazard();
344
345 tlb_write_indexed();
346 tlbw_use_hazard();
347 }
348
349 write_c0_entryhi(old_entryhi);
350 write_c0_pagemask(old_pagemask);
351 mtc0_tlbw_hazard();
352
353 local_irq_restore(flags);
354}
355EXPORT_SYMBOL_GPL(kvm_mips_flush_host_tlb);
356
357void kvm_local_flush_tlb_all(void)
358{
359 unsigned long flags;
360 unsigned long old_ctx;
361 int entry = 0;
362
363 local_irq_save(flags);
364 /* Save old context and create impossible VPN2 value */
365 old_ctx = read_c0_entryhi();
366 write_c0_entrylo0(0);
367 write_c0_entrylo1(0);
368
369 /* Blast 'em all away. */
370 while (entry < current_cpu_data.tlbsize) {
371 /* Make sure all entries differ. */
372 write_c0_entryhi(UNIQUE_ENTRYHI(entry));
373 write_c0_index(entry);
374 mtc0_tlbw_hazard();
375 tlb_write_indexed();
376 tlbw_use_hazard();
377 entry++;
378 }
379 write_c0_entryhi(old_ctx);
380 mtc0_tlbw_hazard();
381
382 local_irq_restore(flags);
383}
384EXPORT_SYMBOL_GPL(kvm_local_flush_tlb_all);