xref: /openbmc/qemu/target/ppc/mmu-hash32.c (revision b097ba37)
1 /*
2  *  PowerPC MMU, TLB and BAT emulation helpers for QEMU.
3  *
4  *  Copyright (c) 2003-2007 Jocelyn Mayer
5  *  Copyright (c) 2013 David Gibson, IBM Corporation
6  *
7  * This library is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2 of the License, or (at your option) any later version.
11  *
12  * This library is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
19  */
20 
21 #include "qemu/osdep.h"
22 #include "cpu.h"
23 #include "exec/exec-all.h"
24 #include "exec/helper-proto.h"
25 #include "sysemu/kvm.h"
26 #include "kvm_ppc.h"
27 #include "mmu-hash32.h"
28 #include "exec/log.h"
29 
30 /* #define DEBUG_BAT */
31 
32 #ifdef DEBUG_BATS
33 #  define LOG_BATS(...) qemu_log_mask(CPU_LOG_MMU, __VA_ARGS__)
34 #else
35 #  define LOG_BATS(...) do { } while (0)
36 #endif
37 
38 struct mmu_ctx_hash32 {
39     hwaddr raddr;      /* Real address              */
40     int prot;                      /* Protection bits           */
41     int key;                       /* Access key                */
42 };
43 
44 static int ppc_hash32_pp_prot(int key, int pp, int nx)
45 {
46     int prot;
47 
48     if (key == 0) {
49         switch (pp) {
50         case 0x0:
51         case 0x1:
52         case 0x2:
53             prot = PAGE_READ | PAGE_WRITE;
54             break;
55 
56         case 0x3:
57             prot = PAGE_READ;
58             break;
59 
60         default:
61             abort();
62         }
63     } else {
64         switch (pp) {
65         case 0x0:
66             prot = 0;
67             break;
68 
69         case 0x1:
70         case 0x3:
71             prot = PAGE_READ;
72             break;
73 
74         case 0x2:
75             prot = PAGE_READ | PAGE_WRITE;
76             break;
77 
78         default:
79             abort();
80         }
81     }
82     if (nx == 0) {
83         prot |= PAGE_EXEC;
84     }
85 
86     return prot;
87 }
88 
89 static int ppc_hash32_pte_prot(PowerPCCPU *cpu,
90                                target_ulong sr, ppc_hash_pte32_t pte)
91 {
92     CPUPPCState *env = &cpu->env;
93     unsigned pp, key;
94 
95     key = !!(msr_pr ? (sr & SR32_KP) : (sr & SR32_KS));
96     pp = pte.pte1 & HPTE32_R_PP;
97 
98     return ppc_hash32_pp_prot(key, pp, !!(sr & SR32_NX));
99 }
100 
101 static target_ulong hash32_bat_size(PowerPCCPU *cpu,
102                                     target_ulong batu, target_ulong batl)
103 {
104     CPUPPCState *env = &cpu->env;
105 
106     if ((msr_pr && !(batu & BATU32_VP))
107         || (!msr_pr && !(batu & BATU32_VS))) {
108         return 0;
109     }
110 
111     return BATU32_BEPI & ~((batu & BATU32_BL) << 15);
112 }
113 
114 static int hash32_bat_prot(PowerPCCPU *cpu,
115                            target_ulong batu, target_ulong batl)
116 {
117     int pp, prot;
118 
119     prot = 0;
120     pp = batl & BATL32_PP;
121     if (pp != 0) {
122         prot = PAGE_READ | PAGE_EXEC;
123         if (pp == 0x2) {
124             prot |= PAGE_WRITE;
125         }
126     }
127     return prot;
128 }
129 
130 static target_ulong hash32_bat_601_size(PowerPCCPU *cpu,
131                                 target_ulong batu, target_ulong batl)
132 {
133     if (!(batl & BATL32_601_V)) {
134         return 0;
135     }
136 
137     return BATU32_BEPI & ~((batl & BATL32_601_BL) << 17);
138 }
139 
140 static int hash32_bat_601_prot(PowerPCCPU *cpu,
141                                target_ulong batu, target_ulong batl)
142 {
143     CPUPPCState *env = &cpu->env;
144     int key, pp;
145 
146     pp = batu & BATU32_601_PP;
147     if (msr_pr == 0) {
148         key = !!(batu & BATU32_601_KS);
149     } else {
150         key = !!(batu & BATU32_601_KP);
151     }
152     return ppc_hash32_pp_prot(key, pp, 0);
153 }
154 
155 static hwaddr ppc_hash32_bat_lookup(PowerPCCPU *cpu, target_ulong ea, int rwx,
156                                     int *prot)
157 {
158     CPUPPCState *env = &cpu->env;
159     target_ulong *BATlt, *BATut;
160     int i;
161 
162     LOG_BATS("%s: %cBAT v " TARGET_FMT_lx "\n", __func__,
163              rwx == 2 ? 'I' : 'D', ea);
164     if (rwx == 2) {
165         BATlt = env->IBAT[1];
166         BATut = env->IBAT[0];
167     } else {
168         BATlt = env->DBAT[1];
169         BATut = env->DBAT[0];
170     }
171     for (i = 0; i < env->nb_BATs; i++) {
172         target_ulong batu = BATut[i];
173         target_ulong batl = BATlt[i];
174         target_ulong mask;
175 
176         if (unlikely(env->mmu_model == POWERPC_MMU_601)) {
177             mask = hash32_bat_601_size(cpu, batu, batl);
178         } else {
179             mask = hash32_bat_size(cpu, batu, batl);
180         }
181         LOG_BATS("%s: %cBAT%d v " TARGET_FMT_lx " BATu " TARGET_FMT_lx
182                  " BATl " TARGET_FMT_lx "\n", __func__,
183                  type == ACCESS_CODE ? 'I' : 'D', i, ea, batu, batl);
184 
185         if (mask && ((ea & mask) == (batu & BATU32_BEPI))) {
186             hwaddr raddr = (batl & mask) | (ea & ~mask);
187 
188             if (unlikely(env->mmu_model == POWERPC_MMU_601)) {
189                 *prot = hash32_bat_601_prot(cpu, batu, batl);
190             } else {
191                 *prot = hash32_bat_prot(cpu, batu, batl);
192             }
193 
194             return raddr & TARGET_PAGE_MASK;
195         }
196     }
197 
198     /* No hit */
199 #if defined(DEBUG_BATS)
200     if (qemu_log_enabled()) {
201         LOG_BATS("no BAT match for " TARGET_FMT_lx ":\n", ea);
202         for (i = 0; i < 4; i++) {
203             BATu = &BATut[i];
204             BATl = &BATlt[i];
205             BEPIu = *BATu & BATU32_BEPIU;
206             BEPIl = *BATu & BATU32_BEPIL;
207             bl = (*BATu & 0x00001FFC) << 15;
208             LOG_BATS("%s: %cBAT%d v " TARGET_FMT_lx " BATu " TARGET_FMT_lx
209                      " BATl " TARGET_FMT_lx "\n\t" TARGET_FMT_lx " "
210                      TARGET_FMT_lx " " TARGET_FMT_lx "\n",
211                      __func__, type == ACCESS_CODE ? 'I' : 'D', i, ea,
212                      *BATu, *BATl, BEPIu, BEPIl, bl);
213         }
214     }
215 #endif
216 
217     return -1;
218 }
219 
220 static int ppc_hash32_direct_store(PowerPCCPU *cpu, target_ulong sr,
221                                    target_ulong eaddr, int rwx,
222                                    hwaddr *raddr, int *prot)
223 {
224     CPUState *cs = CPU(cpu);
225     CPUPPCState *env = &cpu->env;
226     int key = !!(msr_pr ? (sr & SR32_KP) : (sr & SR32_KS));
227 
228     qemu_log_mask(CPU_LOG_MMU, "direct store...\n");
229 
230     if ((sr & 0x1FF00000) >> 20 == 0x07f) {
231         /*
232          * Memory-forced I/O controller interface access
233          *
234          * If T=1 and BUID=x'07F', the 601 performs a memory access
235          * to SR[28-31] LA[4-31], bypassing all protection mechanisms.
236          */
237         *raddr = ((sr & 0xF) << 28) | (eaddr & 0x0FFFFFFF);
238         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
239         return 0;
240     }
241 
242     if (rwx == 2) {
243         /* No code fetch is allowed in direct-store areas */
244         cs->exception_index = POWERPC_EXCP_ISI;
245         env->error_code = 0x10000000;
246         return 1;
247     }
248 
249     switch (env->access_type) {
250     case ACCESS_INT:
251         /* Integer load/store : only access allowed */
252         break;
253     case ACCESS_FLOAT:
254         /* Floating point load/store */
255         cs->exception_index = POWERPC_EXCP_ALIGN;
256         env->error_code = POWERPC_EXCP_ALIGN_FP;
257         env->spr[SPR_DAR] = eaddr;
258         return 1;
259     case ACCESS_RES:
260         /* lwarx, ldarx or srwcx. */
261         env->error_code = 0;
262         env->spr[SPR_DAR] = eaddr;
263         if (rwx == 1) {
264             env->spr[SPR_DSISR] = 0x06000000;
265         } else {
266             env->spr[SPR_DSISR] = 0x04000000;
267         }
268         return 1;
269     case ACCESS_CACHE:
270         /*
271          * dcba, dcbt, dcbtst, dcbf, dcbi, dcbst, dcbz, or icbi
272          *
273          * Should make the instruction do no-op.  As it already do
274          * no-op, it's quite easy :-)
275          */
276         *raddr = eaddr;
277         return 0;
278     case ACCESS_EXT:
279         /* eciwx or ecowx */
280         cs->exception_index = POWERPC_EXCP_DSI;
281         env->error_code = 0;
282         env->spr[SPR_DAR] = eaddr;
283         if (rwx == 1) {
284             env->spr[SPR_DSISR] = 0x06100000;
285         } else {
286             env->spr[SPR_DSISR] = 0x04100000;
287         }
288         return 1;
289     default:
290         cpu_abort(cs, "ERROR: instruction should not need "
291                  "address translation\n");
292     }
293     if ((rwx == 1 || key != 1) && (rwx == 0 || key != 0)) {
294         *raddr = eaddr;
295         return 0;
296     } else {
297         cs->exception_index = POWERPC_EXCP_DSI;
298         env->error_code = 0;
299         env->spr[SPR_DAR] = eaddr;
300         if (rwx == 1) {
301             env->spr[SPR_DSISR] = 0x0a000000;
302         } else {
303             env->spr[SPR_DSISR] = 0x08000000;
304         }
305         return 1;
306     }
307 }
308 
309 hwaddr get_pteg_offset32(PowerPCCPU *cpu, hwaddr hash)
310 {
311     target_ulong mask = ppc_hash32_hpt_mask(cpu);
312 
313     return (hash * HASH_PTEG_SIZE_32) & mask;
314 }
315 
316 static hwaddr ppc_hash32_pteg_search(PowerPCCPU *cpu, hwaddr pteg_off,
317                                      bool secondary, target_ulong ptem,
318                                      ppc_hash_pte32_t *pte)
319 {
320     hwaddr pte_offset = pteg_off;
321     target_ulong pte0, pte1;
322     int i;
323 
324     for (i = 0; i < HPTES_PER_GROUP; i++) {
325         pte0 = ppc_hash32_load_hpte0(cpu, pte_offset);
326         /*
327          * pte0 contains the valid bit and must be read before pte1,
328          * otherwise we might see an old pte1 with a new valid bit and
329          * thus an inconsistent hpte value
330          */
331         smp_rmb();
332         pte1 = ppc_hash32_load_hpte1(cpu, pte_offset);
333 
334         if ((pte0 & HPTE32_V_VALID)
335             && (secondary == !!(pte0 & HPTE32_V_SECONDARY))
336             && HPTE32_V_COMPARE(pte0, ptem)) {
337             pte->pte0 = pte0;
338             pte->pte1 = pte1;
339             return pte_offset;
340         }
341 
342         pte_offset += HASH_PTE_SIZE_32;
343     }
344 
345     return -1;
346 }
347 
348 static void ppc_hash32_set_r(PowerPCCPU *cpu, hwaddr pte_offset, uint32_t pte1)
349 {
350     target_ulong base = ppc_hash32_hpt_base(cpu);
351     hwaddr offset = pte_offset + 6;
352 
353     /* The HW performs a non-atomic byte update */
354     stb_phys(CPU(cpu)->as, base + offset, ((pte1 >> 8) & 0xff) | 0x01);
355 }
356 
357 static void ppc_hash32_set_c(PowerPCCPU *cpu, hwaddr pte_offset, uint64_t pte1)
358 {
359     target_ulong base = ppc_hash32_hpt_base(cpu);
360     hwaddr offset = pte_offset + 7;
361 
362     /* The HW performs a non-atomic byte update */
363     stb_phys(CPU(cpu)->as, base + offset, (pte1 & 0xff) | 0x80);
364 }
365 
366 static hwaddr ppc_hash32_htab_lookup(PowerPCCPU *cpu,
367                                      target_ulong sr, target_ulong eaddr,
368                                      ppc_hash_pte32_t *pte)
369 {
370     hwaddr pteg_off, pte_offset;
371     hwaddr hash;
372     uint32_t vsid, pgidx, ptem;
373 
374     vsid = sr & SR32_VSID;
375     pgidx = (eaddr & ~SEGMENT_MASK_256M) >> TARGET_PAGE_BITS;
376     hash = vsid ^ pgidx;
377     ptem = (vsid << 7) | (pgidx >> 10);
378 
379     /* Page address translation */
380     qemu_log_mask(CPU_LOG_MMU, "htab_base " TARGET_FMT_plx
381             " htab_mask " TARGET_FMT_plx
382             " hash " TARGET_FMT_plx "\n",
383             ppc_hash32_hpt_base(cpu), ppc_hash32_hpt_mask(cpu), hash);
384 
385     /* Primary PTEG lookup */
386     qemu_log_mask(CPU_LOG_MMU, "0 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
387             " vsid=%" PRIx32 " ptem=%" PRIx32
388             " hash=" TARGET_FMT_plx "\n",
389             ppc_hash32_hpt_base(cpu), ppc_hash32_hpt_mask(cpu),
390             vsid, ptem, hash);
391     pteg_off = get_pteg_offset32(cpu, hash);
392     pte_offset = ppc_hash32_pteg_search(cpu, pteg_off, 0, ptem, pte);
393     if (pte_offset == -1) {
394         /* Secondary PTEG lookup */
395         qemu_log_mask(CPU_LOG_MMU, "1 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
396                 " vsid=%" PRIx32 " api=%" PRIx32
397                 " hash=" TARGET_FMT_plx "\n", ppc_hash32_hpt_base(cpu),
398                 ppc_hash32_hpt_mask(cpu), vsid, ptem, ~hash);
399         pteg_off = get_pteg_offset32(cpu, ~hash);
400         pte_offset = ppc_hash32_pteg_search(cpu, pteg_off, 1, ptem, pte);
401     }
402 
403     return pte_offset;
404 }
405 
406 static hwaddr ppc_hash32_pte_raddr(target_ulong sr, ppc_hash_pte32_t pte,
407                                    target_ulong eaddr)
408 {
409     hwaddr rpn = pte.pte1 & HPTE32_R_RPN;
410     hwaddr mask = ~TARGET_PAGE_MASK;
411 
412     return (rpn & ~mask) | (eaddr & mask);
413 }
414 
415 int ppc_hash32_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
416                                 int mmu_idx)
417 {
418     CPUState *cs = CPU(cpu);
419     CPUPPCState *env = &cpu->env;
420     target_ulong sr;
421     hwaddr pte_offset;
422     ppc_hash_pte32_t pte;
423     int prot;
424     const int need_prot[] = {PAGE_READ, PAGE_WRITE, PAGE_EXEC};
425     hwaddr raddr;
426 
427     assert((rwx == 0) || (rwx == 1) || (rwx == 2));
428 
429     /* 1. Handle real mode accesses */
430     if (((rwx == 2) && (msr_ir == 0)) || ((rwx != 2) && (msr_dr == 0))) {
431         /* Translation is off */
432         raddr = eaddr;
433         tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
434                      PAGE_READ | PAGE_WRITE | PAGE_EXEC, mmu_idx,
435                      TARGET_PAGE_SIZE);
436         return 0;
437     }
438 
439     /* 2. Check Block Address Translation entries (BATs) */
440     if (env->nb_BATs != 0) {
441         raddr = ppc_hash32_bat_lookup(cpu, eaddr, rwx, &prot);
442         if (raddr != -1) {
443             if (need_prot[rwx] & ~prot) {
444                 if (rwx == 2) {
445                     cs->exception_index = POWERPC_EXCP_ISI;
446                     env->error_code = 0x08000000;
447                 } else {
448                     cs->exception_index = POWERPC_EXCP_DSI;
449                     env->error_code = 0;
450                     env->spr[SPR_DAR] = eaddr;
451                     if (rwx == 1) {
452                         env->spr[SPR_DSISR] = 0x0a000000;
453                     } else {
454                         env->spr[SPR_DSISR] = 0x08000000;
455                     }
456                 }
457                 return 1;
458             }
459 
460             tlb_set_page(cs, eaddr & TARGET_PAGE_MASK,
461                          raddr & TARGET_PAGE_MASK, prot, mmu_idx,
462                          TARGET_PAGE_SIZE);
463             return 0;
464         }
465     }
466 
467     /* 3. Look up the Segment Register */
468     sr = env->sr[eaddr >> 28];
469 
470     /* 4. Handle direct store segments */
471     if (sr & SR32_T) {
472         if (ppc_hash32_direct_store(cpu, sr, eaddr, rwx,
473                                     &raddr, &prot) == 0) {
474             tlb_set_page(cs, eaddr & TARGET_PAGE_MASK,
475                          raddr & TARGET_PAGE_MASK, prot, mmu_idx,
476                          TARGET_PAGE_SIZE);
477             return 0;
478         } else {
479             return 1;
480         }
481     }
482 
483     /* 5. Check for segment level no-execute violation */
484     if ((rwx == 2) && (sr & SR32_NX)) {
485         cs->exception_index = POWERPC_EXCP_ISI;
486         env->error_code = 0x10000000;
487         return 1;
488     }
489 
490     /* 6. Locate the PTE in the hash table */
491     pte_offset = ppc_hash32_htab_lookup(cpu, sr, eaddr, &pte);
492     if (pte_offset == -1) {
493         if (rwx == 2) {
494             cs->exception_index = POWERPC_EXCP_ISI;
495             env->error_code = 0x40000000;
496         } else {
497             cs->exception_index = POWERPC_EXCP_DSI;
498             env->error_code = 0;
499             env->spr[SPR_DAR] = eaddr;
500             if (rwx == 1) {
501                 env->spr[SPR_DSISR] = 0x42000000;
502             } else {
503                 env->spr[SPR_DSISR] = 0x40000000;
504             }
505         }
506 
507         return 1;
508     }
509     qemu_log_mask(CPU_LOG_MMU,
510                 "found PTE at offset %08" HWADDR_PRIx "\n", pte_offset);
511 
512     /* 7. Check access permissions */
513 
514     prot = ppc_hash32_pte_prot(cpu, sr, pte);
515 
516     if (need_prot[rwx] & ~prot) {
517         /* Access right violation */
518         qemu_log_mask(CPU_LOG_MMU, "PTE access rejected\n");
519         if (rwx == 2) {
520             cs->exception_index = POWERPC_EXCP_ISI;
521             env->error_code = 0x08000000;
522         } else {
523             cs->exception_index = POWERPC_EXCP_DSI;
524             env->error_code = 0;
525             env->spr[SPR_DAR] = eaddr;
526             if (rwx == 1) {
527                 env->spr[SPR_DSISR] = 0x0a000000;
528             } else {
529                 env->spr[SPR_DSISR] = 0x08000000;
530             }
531         }
532         return 1;
533     }
534 
535     qemu_log_mask(CPU_LOG_MMU, "PTE access granted !\n");
536 
537     /* 8. Update PTE referenced and changed bits if necessary */
538 
539     if (!(pte.pte1 & HPTE32_R_R)) {
540         ppc_hash32_set_r(cpu, pte_offset, pte.pte1);
541     }
542     if (!(pte.pte1 & HPTE32_R_C)) {
543         if (rwx == 1) {
544             ppc_hash32_set_c(cpu, pte_offset, pte.pte1);
545         } else {
546             /*
547              * Treat the page as read-only for now, so that a later write
548              * will pass through this function again to set the C bit
549              */
550             prot &= ~PAGE_WRITE;
551         }
552      }
553 
554     /* 9. Determine the real address from the PTE */
555 
556     raddr = ppc_hash32_pte_raddr(sr, pte, eaddr);
557 
558     tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
559                  prot, mmu_idx, TARGET_PAGE_SIZE);
560 
561     return 0;
562 }
563 
564 hwaddr ppc_hash32_get_phys_page_debug(PowerPCCPU *cpu, target_ulong eaddr)
565 {
566     CPUPPCState *env = &cpu->env;
567     target_ulong sr;
568     hwaddr pte_offset;
569     ppc_hash_pte32_t pte;
570     int prot;
571 
572     if (msr_dr == 0) {
573         /* Translation is off */
574         return eaddr;
575     }
576 
577     if (env->nb_BATs != 0) {
578         hwaddr raddr = ppc_hash32_bat_lookup(cpu, eaddr, 0, &prot);
579         if (raddr != -1) {
580             return raddr;
581         }
582     }
583 
584     sr = env->sr[eaddr >> 28];
585 
586     if (sr & SR32_T) {
587         /* FIXME: Add suitable debug support for Direct Store segments */
588         return -1;
589     }
590 
591     pte_offset = ppc_hash32_htab_lookup(cpu, sr, eaddr, &pte);
592     if (pte_offset == -1) {
593         return -1;
594     }
595 
596     return ppc_hash32_pte_raddr(sr, pte, eaddr) & TARGET_PAGE_MASK;
597 }
598