xref: /openbmc/qemu/target/ppc/mmu-hash32.c (revision ba1b5df070bb4cf1632aaefa4e17d42881d49988)
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 2.1 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 "sysemu/kvm.h"
25 #include "kvm_ppc.h"
26 #include "internal.h"
27 #include "mmu-hash32.h"
28 #include "exec/log.h"
29 
30 /* #define DEBUG_BATS */
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,
156                                     MMUAccessType access_type, int *prot)
157 {
158     CPUPPCState *env = &cpu->env;
159     target_ulong *BATlt, *BATut;
160     bool ifetch = access_type == MMU_INST_FETCH;
161     int i;
162 
163     LOG_BATS("%s: %cBAT v " TARGET_FMT_lx "\n", __func__,
164              ifetch ? 'I' : 'D', ea);
165     if (ifetch) {
166         BATlt = env->IBAT[1];
167         BATut = env->IBAT[0];
168     } else {
169         BATlt = env->DBAT[1];
170         BATut = env->DBAT[0];
171     }
172     for (i = 0; i < env->nb_BATs; i++) {
173         target_ulong batu = BATut[i];
174         target_ulong batl = BATlt[i];
175         target_ulong mask;
176 
177         if (unlikely(env->mmu_model == POWERPC_MMU_601)) {
178             mask = hash32_bat_601_size(cpu, batu, batl);
179         } else {
180             mask = hash32_bat_size(cpu, batu, batl);
181         }
182         LOG_BATS("%s: %cBAT%d v " TARGET_FMT_lx " BATu " TARGET_FMT_lx
183                  " BATl " TARGET_FMT_lx "\n", __func__,
184                  ifetch ? 'I' : 'D', i, ea, batu, batl);
185 
186         if (mask && ((ea & mask) == (batu & BATU32_BEPI))) {
187             hwaddr raddr = (batl & mask) | (ea & ~mask);
188 
189             if (unlikely(env->mmu_model == POWERPC_MMU_601)) {
190                 *prot = hash32_bat_601_prot(cpu, batu, batl);
191             } else {
192                 *prot = hash32_bat_prot(cpu, batu, batl);
193             }
194 
195             return raddr & TARGET_PAGE_MASK;
196         }
197     }
198 
199     /* No hit */
200 #if defined(DEBUG_BATS)
201     if (qemu_log_enabled()) {
202         target_ulong *BATu, *BATl;
203         target_ulong BEPIl, BEPIu, bl;
204 
205         LOG_BATS("no BAT match for " TARGET_FMT_lx ":\n", ea);
206         for (i = 0; i < 4; i++) {
207             BATu = &BATut[i];
208             BATl = &BATlt[i];
209             BEPIu = *BATu & BATU32_BEPIU;
210             BEPIl = *BATu & BATU32_BEPIL;
211             bl = (*BATu & 0x00001FFC) << 15;
212             LOG_BATS("%s: %cBAT%d v " TARGET_FMT_lx " BATu " TARGET_FMT_lx
213                      " BATl " TARGET_FMT_lx "\n\t" TARGET_FMT_lx " "
214                      TARGET_FMT_lx " " TARGET_FMT_lx "\n",
215                      __func__, ifetch ? 'I' : 'D', i, ea,
216                      *BATu, *BATl, BEPIu, BEPIl, bl);
217         }
218     }
219 #endif
220 
221     return -1;
222 }
223 
224 static bool ppc_hash32_direct_store(PowerPCCPU *cpu, target_ulong sr,
225                                     target_ulong eaddr,
226                                     MMUAccessType access_type,
227                                     hwaddr *raddr, int *prot,
228                                     bool guest_visible)
229 {
230     CPUState *cs = CPU(cpu);
231     CPUPPCState *env = &cpu->env;
232     int key = !!(msr_pr ? (sr & SR32_KP) : (sr & SR32_KS));
233 
234     qemu_log_mask(CPU_LOG_MMU, "direct store...\n");
235 
236     if ((sr & 0x1FF00000) >> 20 == 0x07f) {
237         /*
238          * Memory-forced I/O controller interface access
239          *
240          * If T=1 and BUID=x'07F', the 601 performs a memory access
241          * to SR[28-31] LA[4-31], bypassing all protection mechanisms.
242          */
243         *raddr = ((sr & 0xF) << 28) | (eaddr & 0x0FFFFFFF);
244         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
245         return true;
246     }
247 
248     if (access_type == MMU_INST_FETCH) {
249         /* No code fetch is allowed in direct-store areas */
250         if (guest_visible) {
251             cs->exception_index = POWERPC_EXCP_ISI;
252             env->error_code = 0x10000000;
253         }
254         return false;
255     }
256 
257     /*
258      * From ppc_cpu_get_phys_page_debug, env->access_type is not set.
259      * Assume ACCESS_INT for that case.
260      */
261     switch (guest_visible ? env->access_type : ACCESS_INT) {
262     case ACCESS_INT:
263         /* Integer load/store : only access allowed */
264         break;
265     case ACCESS_FLOAT:
266         /* Floating point load/store */
267         cs->exception_index = POWERPC_EXCP_ALIGN;
268         env->error_code = POWERPC_EXCP_ALIGN_FP;
269         env->spr[SPR_DAR] = eaddr;
270         return false;
271     case ACCESS_RES:
272         /* lwarx, ldarx or srwcx. */
273         env->error_code = 0;
274         env->spr[SPR_DAR] = eaddr;
275         if (access_type == MMU_DATA_STORE) {
276             env->spr[SPR_DSISR] = 0x06000000;
277         } else {
278             env->spr[SPR_DSISR] = 0x04000000;
279         }
280         return false;
281     case ACCESS_CACHE:
282         /*
283          * dcba, dcbt, dcbtst, dcbf, dcbi, dcbst, dcbz, or icbi
284          *
285          * Should make the instruction do no-op.  As it already do
286          * no-op, it's quite easy :-)
287          */
288         *raddr = eaddr;
289         return true;
290     case ACCESS_EXT:
291         /* eciwx or ecowx */
292         cs->exception_index = POWERPC_EXCP_DSI;
293         env->error_code = 0;
294         env->spr[SPR_DAR] = eaddr;
295         if (access_type == MMU_DATA_STORE) {
296             env->spr[SPR_DSISR] = 0x06100000;
297         } else {
298             env->spr[SPR_DSISR] = 0x04100000;
299         }
300         return false;
301     default:
302         cpu_abort(cs, "ERROR: insn should not need address translation\n");
303     }
304 
305     *prot = key ? PAGE_READ | PAGE_WRITE : PAGE_READ;
306     if (*prot & prot_for_access_type(access_type)) {
307         *raddr = eaddr;
308         return true;
309     }
310 
311     if (guest_visible) {
312         cs->exception_index = POWERPC_EXCP_DSI;
313         env->error_code = 0;
314         env->spr[SPR_DAR] = eaddr;
315         if (access_type == MMU_DATA_STORE) {
316             env->spr[SPR_DSISR] = 0x0a000000;
317         } else {
318             env->spr[SPR_DSISR] = 0x08000000;
319         }
320     }
321     return false;
322 }
323 
324 hwaddr get_pteg_offset32(PowerPCCPU *cpu, hwaddr hash)
325 {
326     target_ulong mask = ppc_hash32_hpt_mask(cpu);
327 
328     return (hash * HASH_PTEG_SIZE_32) & mask;
329 }
330 
331 static hwaddr ppc_hash32_pteg_search(PowerPCCPU *cpu, hwaddr pteg_off,
332                                      bool secondary, target_ulong ptem,
333                                      ppc_hash_pte32_t *pte)
334 {
335     hwaddr pte_offset = pteg_off;
336     target_ulong pte0, pte1;
337     int i;
338 
339     for (i = 0; i < HPTES_PER_GROUP; i++) {
340         pte0 = ppc_hash32_load_hpte0(cpu, pte_offset);
341         /*
342          * pte0 contains the valid bit and must be read before pte1,
343          * otherwise we might see an old pte1 with a new valid bit and
344          * thus an inconsistent hpte value
345          */
346         smp_rmb();
347         pte1 = ppc_hash32_load_hpte1(cpu, pte_offset);
348 
349         if ((pte0 & HPTE32_V_VALID)
350             && (secondary == !!(pte0 & HPTE32_V_SECONDARY))
351             && HPTE32_V_COMPARE(pte0, ptem)) {
352             pte->pte0 = pte0;
353             pte->pte1 = pte1;
354             return pte_offset;
355         }
356 
357         pte_offset += HASH_PTE_SIZE_32;
358     }
359 
360     return -1;
361 }
362 
363 static void ppc_hash32_set_r(PowerPCCPU *cpu, hwaddr pte_offset, uint32_t pte1)
364 {
365     target_ulong base = ppc_hash32_hpt_base(cpu);
366     hwaddr offset = pte_offset + 6;
367 
368     /* The HW performs a non-atomic byte update */
369     stb_phys(CPU(cpu)->as, base + offset, ((pte1 >> 8) & 0xff) | 0x01);
370 }
371 
372 static void ppc_hash32_set_c(PowerPCCPU *cpu, hwaddr pte_offset, uint64_t pte1)
373 {
374     target_ulong base = ppc_hash32_hpt_base(cpu);
375     hwaddr offset = pte_offset + 7;
376 
377     /* The HW performs a non-atomic byte update */
378     stb_phys(CPU(cpu)->as, base + offset, (pte1 & 0xff) | 0x80);
379 }
380 
381 static hwaddr ppc_hash32_htab_lookup(PowerPCCPU *cpu,
382                                      target_ulong sr, target_ulong eaddr,
383                                      ppc_hash_pte32_t *pte)
384 {
385     hwaddr pteg_off, pte_offset;
386     hwaddr hash;
387     uint32_t vsid, pgidx, ptem;
388 
389     vsid = sr & SR32_VSID;
390     pgidx = (eaddr & ~SEGMENT_MASK_256M) >> TARGET_PAGE_BITS;
391     hash = vsid ^ pgidx;
392     ptem = (vsid << 7) | (pgidx >> 10);
393 
394     /* Page address translation */
395     qemu_log_mask(CPU_LOG_MMU, "htab_base " TARGET_FMT_plx
396             " htab_mask " TARGET_FMT_plx
397             " hash " TARGET_FMT_plx "\n",
398             ppc_hash32_hpt_base(cpu), ppc_hash32_hpt_mask(cpu), hash);
399 
400     /* Primary PTEG lookup */
401     qemu_log_mask(CPU_LOG_MMU, "0 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
402             " vsid=%" PRIx32 " ptem=%" PRIx32
403             " hash=" TARGET_FMT_plx "\n",
404             ppc_hash32_hpt_base(cpu), ppc_hash32_hpt_mask(cpu),
405             vsid, ptem, hash);
406     pteg_off = get_pteg_offset32(cpu, hash);
407     pte_offset = ppc_hash32_pteg_search(cpu, pteg_off, 0, ptem, pte);
408     if (pte_offset == -1) {
409         /* Secondary PTEG lookup */
410         qemu_log_mask(CPU_LOG_MMU, "1 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
411                 " vsid=%" PRIx32 " api=%" PRIx32
412                 " hash=" TARGET_FMT_plx "\n", ppc_hash32_hpt_base(cpu),
413                 ppc_hash32_hpt_mask(cpu), vsid, ptem, ~hash);
414         pteg_off = get_pteg_offset32(cpu, ~hash);
415         pte_offset = ppc_hash32_pteg_search(cpu, pteg_off, 1, ptem, pte);
416     }
417 
418     return pte_offset;
419 }
420 
421 static hwaddr ppc_hash32_pte_raddr(target_ulong sr, ppc_hash_pte32_t pte,
422                                    target_ulong eaddr)
423 {
424     hwaddr rpn = pte.pte1 & HPTE32_R_RPN;
425     hwaddr mask = ~TARGET_PAGE_MASK;
426 
427     return (rpn & ~mask) | (eaddr & mask);
428 }
429 
430 bool ppc_hash32_xlate(PowerPCCPU *cpu, vaddr eaddr, MMUAccessType access_type,
431                       hwaddr *raddrp, int *psizep, int *protp,
432                       bool guest_visible)
433 {
434     CPUState *cs = CPU(cpu);
435     CPUPPCState *env = &cpu->env;
436     target_ulong sr;
437     hwaddr pte_offset;
438     ppc_hash_pte32_t pte;
439     int prot;
440     int need_prot;
441     hwaddr raddr;
442 
443     /* There are no hash32 large pages. */
444     *psizep = TARGET_PAGE_BITS;
445 
446     /* 1. Handle real mode accesses */
447     if (access_type == MMU_INST_FETCH ? !msr_ir : !msr_dr) {
448         /* Translation is off */
449         *raddrp = eaddr;
450         *protp = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
451         return true;
452     }
453 
454     need_prot = prot_for_access_type(access_type);
455 
456     /* 2. Check Block Address Translation entries (BATs) */
457     if (env->nb_BATs != 0) {
458         raddr = ppc_hash32_bat_lookup(cpu, eaddr, access_type, protp);
459         if (raddr != -1) {
460             if (need_prot & ~*protp) {
461                 if (guest_visible) {
462                     if (access_type == MMU_INST_FETCH) {
463                         cs->exception_index = POWERPC_EXCP_ISI;
464                         env->error_code = 0x08000000;
465                     } else {
466                         cs->exception_index = POWERPC_EXCP_DSI;
467                         env->error_code = 0;
468                         env->spr[SPR_DAR] = eaddr;
469                         if (access_type == MMU_DATA_STORE) {
470                             env->spr[SPR_DSISR] = 0x0a000000;
471                         } else {
472                             env->spr[SPR_DSISR] = 0x08000000;
473                         }
474                     }
475                 }
476                 return false;
477             }
478             *raddrp = raddr;
479             return true;
480         }
481     }
482 
483     /* 3. Look up the Segment Register */
484     sr = env->sr[eaddr >> 28];
485 
486     /* 4. Handle direct store segments */
487     if (sr & SR32_T) {
488         return ppc_hash32_direct_store(cpu, sr, eaddr, access_type,
489                                        raddrp, protp, guest_visible);
490     }
491 
492     /* 5. Check for segment level no-execute violation */
493     if (access_type == MMU_INST_FETCH && (sr & SR32_NX)) {
494         if (guest_visible) {
495             cs->exception_index = POWERPC_EXCP_ISI;
496             env->error_code = 0x10000000;
497         }
498         return false;
499     }
500 
501     /* 6. Locate the PTE in the hash table */
502     pte_offset = ppc_hash32_htab_lookup(cpu, sr, eaddr, &pte);
503     if (pte_offset == -1) {
504         if (guest_visible) {
505             if (access_type == MMU_INST_FETCH) {
506                 cs->exception_index = POWERPC_EXCP_ISI;
507                 env->error_code = 0x40000000;
508             } else {
509                 cs->exception_index = POWERPC_EXCP_DSI;
510                 env->error_code = 0;
511                 env->spr[SPR_DAR] = eaddr;
512                 if (access_type == MMU_DATA_STORE) {
513                     env->spr[SPR_DSISR] = 0x42000000;
514                 } else {
515                     env->spr[SPR_DSISR] = 0x40000000;
516                 }
517             }
518         }
519         return false;
520     }
521     qemu_log_mask(CPU_LOG_MMU,
522                 "found PTE at offset %08" HWADDR_PRIx "\n", pte_offset);
523 
524     /* 7. Check access permissions */
525 
526     prot = ppc_hash32_pte_prot(cpu, sr, pte);
527 
528     if (need_prot & ~prot) {
529         /* Access right violation */
530         qemu_log_mask(CPU_LOG_MMU, "PTE access rejected\n");
531         if (guest_visible) {
532             if (access_type == MMU_INST_FETCH) {
533                 cs->exception_index = POWERPC_EXCP_ISI;
534                 env->error_code = 0x08000000;
535             } else {
536                 cs->exception_index = POWERPC_EXCP_DSI;
537                 env->error_code = 0;
538                 env->spr[SPR_DAR] = eaddr;
539                 if (access_type == MMU_DATA_STORE) {
540                     env->spr[SPR_DSISR] = 0x0a000000;
541                 } else {
542                     env->spr[SPR_DSISR] = 0x08000000;
543                 }
544             }
545         }
546         return false;
547     }
548 
549     qemu_log_mask(CPU_LOG_MMU, "PTE access granted !\n");
550 
551     /* 8. Update PTE referenced and changed bits if necessary */
552 
553     if (!(pte.pte1 & HPTE32_R_R)) {
554         ppc_hash32_set_r(cpu, pte_offset, pte.pte1);
555     }
556     if (!(pte.pte1 & HPTE32_R_C)) {
557         if (access_type == MMU_DATA_STORE) {
558             ppc_hash32_set_c(cpu, pte_offset, pte.pte1);
559         } else {
560             /*
561              * Treat the page as read-only for now, so that a later write
562              * will pass through this function again to set the C bit
563              */
564             prot &= ~PAGE_WRITE;
565         }
566      }
567 
568     /* 9. Determine the real address from the PTE */
569 
570     *raddrp = ppc_hash32_pte_raddr(sr, pte, eaddr);
571     *protp = prot;
572     return true;
573 }
574