xref: /openbmc/qemu/target/ppc/mmu-hash32.c (revision b91a0fa7)
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 "mmu-books.h"
29 #include "exec/log.h"
30 
31 /* #define DEBUG_BATS */
32 
33 #ifdef DEBUG_BATS
34 #  define LOG_BATS(...) qemu_log_mask(CPU_LOG_MMU, __VA_ARGS__)
35 #else
36 #  define LOG_BATS(...) do { } while (0)
37 #endif
38 
39 struct mmu_ctx_hash32 {
40     hwaddr raddr;      /* Real address              */
41     int prot;                      /* Protection bits           */
42     int key;                       /* Access key                */
43 };
44 
45 static int ppc_hash32_pp_prot(int key, int pp, int nx)
46 {
47     int prot;
48 
49     if (key == 0) {
50         switch (pp) {
51         case 0x0:
52         case 0x1:
53         case 0x2:
54             prot = PAGE_READ | PAGE_WRITE;
55             break;
56 
57         case 0x3:
58             prot = PAGE_READ;
59             break;
60 
61         default:
62             abort();
63         }
64     } else {
65         switch (pp) {
66         case 0x0:
67             prot = 0;
68             break;
69 
70         case 0x1:
71         case 0x3:
72             prot = PAGE_READ;
73             break;
74 
75         case 0x2:
76             prot = PAGE_READ | PAGE_WRITE;
77             break;
78 
79         default:
80             abort();
81         }
82     }
83     if (nx == 0) {
84         prot |= PAGE_EXEC;
85     }
86 
87     return prot;
88 }
89 
90 static int ppc_hash32_pte_prot(int mmu_idx,
91                                target_ulong sr, ppc_hash_pte32_t pte)
92 {
93     unsigned pp, key;
94 
95     key = !!(mmuidx_pr(mmu_idx) ? (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(int mmu_idx,
102                                     target_ulong batu, target_ulong batl)
103 {
104     if ((mmuidx_pr(mmu_idx) && !(batu & BATU32_VP))
105         || (!mmuidx_pr(mmu_idx) && !(batu & BATU32_VS))) {
106         return 0;
107     }
108 
109     return BATU32_BEPI & ~((batu & BATU32_BL) << 15);
110 }
111 
112 static int hash32_bat_prot(PowerPCCPU *cpu,
113                            target_ulong batu, target_ulong batl)
114 {
115     int pp, prot;
116 
117     prot = 0;
118     pp = batl & BATL32_PP;
119     if (pp != 0) {
120         prot = PAGE_READ | PAGE_EXEC;
121         if (pp == 0x2) {
122             prot |= PAGE_WRITE;
123         }
124     }
125     return prot;
126 }
127 
128 static target_ulong hash32_bat_601_size(PowerPCCPU *cpu,
129                                 target_ulong batu, target_ulong batl)
130 {
131     if (!(batl & BATL32_601_V)) {
132         return 0;
133     }
134 
135     return BATU32_BEPI & ~((batl & BATL32_601_BL) << 17);
136 }
137 
138 static int hash32_bat_601_prot(int mmu_idx,
139                                target_ulong batu, target_ulong batl)
140 {
141     int key, pp;
142 
143     pp = batu & BATU32_601_PP;
144     if (mmuidx_pr(mmu_idx) == 0) {
145         key = !!(batu & BATU32_601_KS);
146     } else {
147         key = !!(batu & BATU32_601_KP);
148     }
149     return ppc_hash32_pp_prot(key, pp, 0);
150 }
151 
152 static hwaddr ppc_hash32_bat_lookup(PowerPCCPU *cpu, target_ulong ea,
153                                     MMUAccessType access_type, int *prot,
154                                     int mmu_idx)
155 {
156     CPUPPCState *env = &cpu->env;
157     target_ulong *BATlt, *BATut;
158     bool ifetch = access_type == MMU_INST_FETCH;
159     int i;
160 
161     LOG_BATS("%s: %cBAT v " TARGET_FMT_lx "\n", __func__,
162              ifetch ? 'I' : 'D', ea);
163     if (ifetch) {
164         BATlt = env->IBAT[1];
165         BATut = env->IBAT[0];
166     } else {
167         BATlt = env->DBAT[1];
168         BATut = env->DBAT[0];
169     }
170     for (i = 0; i < env->nb_BATs; i++) {
171         target_ulong batu = BATut[i];
172         target_ulong batl = BATlt[i];
173         target_ulong mask;
174 
175         if (unlikely(env->mmu_model == POWERPC_MMU_601)) {
176             mask = hash32_bat_601_size(cpu, batu, batl);
177         } else {
178             mask = hash32_bat_size(mmu_idx, batu, batl);
179         }
180         LOG_BATS("%s: %cBAT%d v " TARGET_FMT_lx " BATu " TARGET_FMT_lx
181                  " BATl " TARGET_FMT_lx "\n", __func__,
182                  ifetch ? 'I' : 'D', i, ea, batu, batl);
183 
184         if (mask && ((ea & mask) == (batu & BATU32_BEPI))) {
185             hwaddr raddr = (batl & mask) | (ea & ~mask);
186 
187             if (unlikely(env->mmu_model == POWERPC_MMU_601)) {
188                 *prot = hash32_bat_601_prot(mmu_idx, batu, batl);
189             } else {
190                 *prot = hash32_bat_prot(cpu, batu, batl);
191             }
192 
193             return raddr & TARGET_PAGE_MASK;
194         }
195     }
196 
197     /* No hit */
198 #if defined(DEBUG_BATS)
199     if (qemu_log_enabled()) {
200         target_ulong *BATu, *BATl;
201         target_ulong BEPIl, BEPIu, bl;
202 
203         LOG_BATS("no BAT match for " TARGET_FMT_lx ":\n", ea);
204         for (i = 0; i < 4; i++) {
205             BATu = &BATut[i];
206             BATl = &BATlt[i];
207             BEPIu = *BATu & BATU32_BEPIU;
208             BEPIl = *BATu & BATU32_BEPIL;
209             bl = (*BATu & 0x00001FFC) << 15;
210             LOG_BATS("%s: %cBAT%d v " TARGET_FMT_lx " BATu " TARGET_FMT_lx
211                      " BATl " TARGET_FMT_lx "\n\t" TARGET_FMT_lx " "
212                      TARGET_FMT_lx " " TARGET_FMT_lx "\n",
213                      __func__, ifetch ? 'I' : 'D', i, ea,
214                      *BATu, *BATl, BEPIu, BEPIl, bl);
215         }
216     }
217 #endif
218 
219     return -1;
220 }
221 
222 static bool ppc_hash32_direct_store(PowerPCCPU *cpu, target_ulong sr,
223                                     target_ulong eaddr,
224                                     MMUAccessType access_type,
225                                     hwaddr *raddr, int *prot, int mmu_idx,
226                                     bool guest_visible)
227 {
228     CPUState *cs = CPU(cpu);
229     CPUPPCState *env = &cpu->env;
230     int key = !!(mmuidx_pr(mmu_idx) ? (sr & SR32_KP) : (sr & SR32_KS));
231 
232     qemu_log_mask(CPU_LOG_MMU, "direct store...\n");
233 
234     if ((sr & 0x1FF00000) >> 20 == 0x07f) {
235         /*
236          * Memory-forced I/O controller interface access
237          *
238          * If T=1 and BUID=x'07F', the 601 performs a memory access
239          * to SR[28-31] LA[4-31], bypassing all protection mechanisms.
240          */
241         *raddr = ((sr & 0xF) << 28) | (eaddr & 0x0FFFFFFF);
242         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
243         return true;
244     }
245 
246     if (access_type == MMU_INST_FETCH) {
247         /* No code fetch is allowed in direct-store areas */
248         if (guest_visible) {
249             cs->exception_index = POWERPC_EXCP_ISI;
250             env->error_code = 0x10000000;
251         }
252         return false;
253     }
254 
255     /*
256      * From ppc_cpu_get_phys_page_debug, env->access_type is not set.
257      * Assume ACCESS_INT for that case.
258      */
259     switch (guest_visible ? env->access_type : ACCESS_INT) {
260     case ACCESS_INT:
261         /* Integer load/store : only access allowed */
262         break;
263     case ACCESS_FLOAT:
264         /* Floating point load/store */
265         cs->exception_index = POWERPC_EXCP_ALIGN;
266         env->error_code = POWERPC_EXCP_ALIGN_FP;
267         env->spr[SPR_DAR] = eaddr;
268         return false;
269     case ACCESS_RES:
270         /* lwarx, ldarx or srwcx. */
271         env->error_code = 0;
272         env->spr[SPR_DAR] = eaddr;
273         if (access_type == MMU_DATA_STORE) {
274             env->spr[SPR_DSISR] = 0x06000000;
275         } else {
276             env->spr[SPR_DSISR] = 0x04000000;
277         }
278         return false;
279     case ACCESS_CACHE:
280         /*
281          * dcba, dcbt, dcbtst, dcbf, dcbi, dcbst, dcbz, or icbi
282          *
283          * Should make the instruction do no-op.  As it already do
284          * no-op, it's quite easy :-)
285          */
286         *raddr = eaddr;
287         return true;
288     case ACCESS_EXT:
289         /* eciwx or ecowx */
290         cs->exception_index = POWERPC_EXCP_DSI;
291         env->error_code = 0;
292         env->spr[SPR_DAR] = eaddr;
293         if (access_type == MMU_DATA_STORE) {
294             env->spr[SPR_DSISR] = 0x06100000;
295         } else {
296             env->spr[SPR_DSISR] = 0x04100000;
297         }
298         return false;
299     default:
300         cpu_abort(cs, "ERROR: insn should not need address translation\n");
301     }
302 
303     *prot = key ? PAGE_READ | PAGE_WRITE : PAGE_READ;
304     if (*prot & prot_for_access_type(access_type)) {
305         *raddr = eaddr;
306         return true;
307     }
308 
309     if (guest_visible) {
310         cs->exception_index = POWERPC_EXCP_DSI;
311         env->error_code = 0;
312         env->spr[SPR_DAR] = eaddr;
313         if (access_type == MMU_DATA_STORE) {
314             env->spr[SPR_DSISR] = 0x0a000000;
315         } else {
316             env->spr[SPR_DSISR] = 0x08000000;
317         }
318     }
319     return false;
320 }
321 
322 hwaddr get_pteg_offset32(PowerPCCPU *cpu, hwaddr hash)
323 {
324     target_ulong mask = ppc_hash32_hpt_mask(cpu);
325 
326     return (hash * HASH_PTEG_SIZE_32) & mask;
327 }
328 
329 static hwaddr ppc_hash32_pteg_search(PowerPCCPU *cpu, hwaddr pteg_off,
330                                      bool secondary, target_ulong ptem,
331                                      ppc_hash_pte32_t *pte)
332 {
333     hwaddr pte_offset = pteg_off;
334     target_ulong pte0, pte1;
335     int i;
336 
337     for (i = 0; i < HPTES_PER_GROUP; i++) {
338         pte0 = ppc_hash32_load_hpte0(cpu, pte_offset);
339         /*
340          * pte0 contains the valid bit and must be read before pte1,
341          * otherwise we might see an old pte1 with a new valid bit and
342          * thus an inconsistent hpte value
343          */
344         smp_rmb();
345         pte1 = ppc_hash32_load_hpte1(cpu, pte_offset);
346 
347         if ((pte0 & HPTE32_V_VALID)
348             && (secondary == !!(pte0 & HPTE32_V_SECONDARY))
349             && HPTE32_V_COMPARE(pte0, ptem)) {
350             pte->pte0 = pte0;
351             pte->pte1 = pte1;
352             return pte_offset;
353         }
354 
355         pte_offset += HASH_PTE_SIZE_32;
356     }
357 
358     return -1;
359 }
360 
361 static void ppc_hash32_set_r(PowerPCCPU *cpu, hwaddr pte_offset, uint32_t pte1)
362 {
363     target_ulong base = ppc_hash32_hpt_base(cpu);
364     hwaddr offset = pte_offset + 6;
365 
366     /* The HW performs a non-atomic byte update */
367     stb_phys(CPU(cpu)->as, base + offset, ((pte1 >> 8) & 0xff) | 0x01);
368 }
369 
370 static void ppc_hash32_set_c(PowerPCCPU *cpu, hwaddr pte_offset, uint64_t pte1)
371 {
372     target_ulong base = ppc_hash32_hpt_base(cpu);
373     hwaddr offset = pte_offset + 7;
374 
375     /* The HW performs a non-atomic byte update */
376     stb_phys(CPU(cpu)->as, base + offset, (pte1 & 0xff) | 0x80);
377 }
378 
379 static hwaddr ppc_hash32_htab_lookup(PowerPCCPU *cpu,
380                                      target_ulong sr, target_ulong eaddr,
381                                      ppc_hash_pte32_t *pte)
382 {
383     hwaddr pteg_off, pte_offset;
384     hwaddr hash;
385     uint32_t vsid, pgidx, ptem;
386 
387     vsid = sr & SR32_VSID;
388     pgidx = (eaddr & ~SEGMENT_MASK_256M) >> TARGET_PAGE_BITS;
389     hash = vsid ^ pgidx;
390     ptem = (vsid << 7) | (pgidx >> 10);
391 
392     /* Page address translation */
393     qemu_log_mask(CPU_LOG_MMU, "htab_base " TARGET_FMT_plx
394             " htab_mask " TARGET_FMT_plx
395             " hash " TARGET_FMT_plx "\n",
396             ppc_hash32_hpt_base(cpu), ppc_hash32_hpt_mask(cpu), hash);
397 
398     /* Primary PTEG lookup */
399     qemu_log_mask(CPU_LOG_MMU, "0 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
400             " vsid=%" PRIx32 " ptem=%" PRIx32
401             " hash=" TARGET_FMT_plx "\n",
402             ppc_hash32_hpt_base(cpu), ppc_hash32_hpt_mask(cpu),
403             vsid, ptem, hash);
404     pteg_off = get_pteg_offset32(cpu, hash);
405     pte_offset = ppc_hash32_pteg_search(cpu, pteg_off, 0, ptem, pte);
406     if (pte_offset == -1) {
407         /* Secondary PTEG lookup */
408         qemu_log_mask(CPU_LOG_MMU, "1 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
409                 " vsid=%" PRIx32 " api=%" PRIx32
410                 " hash=" TARGET_FMT_plx "\n", ppc_hash32_hpt_base(cpu),
411                 ppc_hash32_hpt_mask(cpu), vsid, ptem, ~hash);
412         pteg_off = get_pteg_offset32(cpu, ~hash);
413         pte_offset = ppc_hash32_pteg_search(cpu, pteg_off, 1, ptem, pte);
414     }
415 
416     return pte_offset;
417 }
418 
419 static hwaddr ppc_hash32_pte_raddr(target_ulong sr, ppc_hash_pte32_t pte,
420                                    target_ulong eaddr)
421 {
422     hwaddr rpn = pte.pte1 & HPTE32_R_RPN;
423     hwaddr mask = ~TARGET_PAGE_MASK;
424 
425     return (rpn & ~mask) | (eaddr & mask);
426 }
427 
428 bool ppc_hash32_xlate(PowerPCCPU *cpu, vaddr eaddr, MMUAccessType access_type,
429                       hwaddr *raddrp, int *psizep, int *protp, int mmu_idx,
430                       bool guest_visible)
431 {
432     CPUState *cs = CPU(cpu);
433     CPUPPCState *env = &cpu->env;
434     target_ulong sr;
435     hwaddr pte_offset;
436     ppc_hash_pte32_t pte;
437     int prot;
438     int need_prot;
439     hwaddr raddr;
440 
441     /* There are no hash32 large pages. */
442     *psizep = TARGET_PAGE_BITS;
443 
444     /* 1. Handle real mode accesses */
445     if (mmuidx_real(mmu_idx)) {
446         /* Translation is off */
447         *raddrp = eaddr;
448         *protp = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
449         return true;
450     }
451 
452     need_prot = prot_for_access_type(access_type);
453 
454     /* 2. Check Block Address Translation entries (BATs) */
455     if (env->nb_BATs != 0) {
456         raddr = ppc_hash32_bat_lookup(cpu, eaddr, access_type, protp, mmu_idx);
457         if (raddr != -1) {
458             if (need_prot & ~*protp) {
459                 if (guest_visible) {
460                     if (access_type == MMU_INST_FETCH) {
461                         cs->exception_index = POWERPC_EXCP_ISI;
462                         env->error_code = 0x08000000;
463                     } else {
464                         cs->exception_index = POWERPC_EXCP_DSI;
465                         env->error_code = 0;
466                         env->spr[SPR_DAR] = eaddr;
467                         if (access_type == MMU_DATA_STORE) {
468                             env->spr[SPR_DSISR] = 0x0a000000;
469                         } else {
470                             env->spr[SPR_DSISR] = 0x08000000;
471                         }
472                     }
473                 }
474                 return false;
475             }
476             *raddrp = raddr;
477             return true;
478         }
479     }
480 
481     /* 3. Look up the Segment Register */
482     sr = env->sr[eaddr >> 28];
483 
484     /* 4. Handle direct store segments */
485     if (sr & SR32_T) {
486         return ppc_hash32_direct_store(cpu, sr, eaddr, access_type,
487                                        raddrp, protp, mmu_idx, guest_visible);
488     }
489 
490     /* 5. Check for segment level no-execute violation */
491     if (access_type == MMU_INST_FETCH && (sr & SR32_NX)) {
492         if (guest_visible) {
493             cs->exception_index = POWERPC_EXCP_ISI;
494             env->error_code = 0x10000000;
495         }
496         return false;
497     }
498 
499     /* 6. Locate the PTE in the hash table */
500     pte_offset = ppc_hash32_htab_lookup(cpu, sr, eaddr, &pte);
501     if (pte_offset == -1) {
502         if (guest_visible) {
503             if (access_type == MMU_INST_FETCH) {
504                 cs->exception_index = POWERPC_EXCP_ISI;
505                 env->error_code = 0x40000000;
506             } else {
507                 cs->exception_index = POWERPC_EXCP_DSI;
508                 env->error_code = 0;
509                 env->spr[SPR_DAR] = eaddr;
510                 if (access_type == MMU_DATA_STORE) {
511                     env->spr[SPR_DSISR] = 0x42000000;
512                 } else {
513                     env->spr[SPR_DSISR] = 0x40000000;
514                 }
515             }
516         }
517         return false;
518     }
519     qemu_log_mask(CPU_LOG_MMU,
520                 "found PTE at offset %08" HWADDR_PRIx "\n", pte_offset);
521 
522     /* 7. Check access permissions */
523 
524     prot = ppc_hash32_pte_prot(mmu_idx, sr, pte);
525 
526     if (need_prot & ~prot) {
527         /* Access right violation */
528         qemu_log_mask(CPU_LOG_MMU, "PTE access rejected\n");
529         if (guest_visible) {
530             if (access_type == MMU_INST_FETCH) {
531                 cs->exception_index = POWERPC_EXCP_ISI;
532                 env->error_code = 0x08000000;
533             } else {
534                 cs->exception_index = POWERPC_EXCP_DSI;
535                 env->error_code = 0;
536                 env->spr[SPR_DAR] = eaddr;
537                 if (access_type == MMU_DATA_STORE) {
538                     env->spr[SPR_DSISR] = 0x0a000000;
539                 } else {
540                     env->spr[SPR_DSISR] = 0x08000000;
541                 }
542             }
543         }
544         return false;
545     }
546 
547     qemu_log_mask(CPU_LOG_MMU, "PTE access granted !\n");
548 
549     /* 8. Update PTE referenced and changed bits if necessary */
550 
551     if (!(pte.pte1 & HPTE32_R_R)) {
552         ppc_hash32_set_r(cpu, pte_offset, pte.pte1);
553     }
554     if (!(pte.pte1 & HPTE32_R_C)) {
555         if (access_type == MMU_DATA_STORE) {
556             ppc_hash32_set_c(cpu, pte_offset, pte.pte1);
557         } else {
558             /*
559              * Treat the page as read-only for now, so that a later write
560              * will pass through this function again to set the C bit
561              */
562             prot &= ~PAGE_WRITE;
563         }
564      }
565 
566     /* 9. Determine the real address from the PTE */
567 
568     *raddrp = ppc_hash32_pte_raddr(sr, pte, eaddr);
569     *protp = prot;
570     return true;
571 }
572