xref: /openbmc/qemu/target/ppc/mmu-hash32.c (revision 824f4bac)
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 "exec/helper-proto.h"
25 #include "sysemu/kvm.h"
26 #include "kvm_ppc.h"
27 #include "internal.h"
28 #include "mmu-hash32.h"
29 #include "exec/log.h"
30 
31 /* #define DEBUG_BAT */
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(PowerPCCPU *cpu,
91                                target_ulong sr, ppc_hash_pte32_t pte)
92 {
93     CPUPPCState *env = &cpu->env;
94     unsigned pp, key;
95 
96     key = !!(msr_pr ? (sr & SR32_KP) : (sr & SR32_KS));
97     pp = pte.pte1 & HPTE32_R_PP;
98 
99     return ppc_hash32_pp_prot(key, pp, !!(sr & SR32_NX));
100 }
101 
102 static target_ulong hash32_bat_size(PowerPCCPU *cpu,
103                                     target_ulong batu, target_ulong batl)
104 {
105     CPUPPCState *env = &cpu->env;
106 
107     if ((msr_pr && !(batu & BATU32_VP))
108         || (!msr_pr && !(batu & BATU32_VS))) {
109         return 0;
110     }
111 
112     return BATU32_BEPI & ~((batu & BATU32_BL) << 15);
113 }
114 
115 static int hash32_bat_prot(PowerPCCPU *cpu,
116                            target_ulong batu, target_ulong batl)
117 {
118     int pp, prot;
119 
120     prot = 0;
121     pp = batl & BATL32_PP;
122     if (pp != 0) {
123         prot = PAGE_READ | PAGE_EXEC;
124         if (pp == 0x2) {
125             prot |= PAGE_WRITE;
126         }
127     }
128     return prot;
129 }
130 
131 static target_ulong hash32_bat_601_size(PowerPCCPU *cpu,
132                                 target_ulong batu, target_ulong batl)
133 {
134     if (!(batl & BATL32_601_V)) {
135         return 0;
136     }
137 
138     return BATU32_BEPI & ~((batl & BATL32_601_BL) << 17);
139 }
140 
141 static int hash32_bat_601_prot(PowerPCCPU *cpu,
142                                target_ulong batu, target_ulong batl)
143 {
144     CPUPPCState *env = &cpu->env;
145     int key, pp;
146 
147     pp = batu & BATU32_601_PP;
148     if (msr_pr == 0) {
149         key = !!(batu & BATU32_601_KS);
150     } else {
151         key = !!(batu & BATU32_601_KP);
152     }
153     return ppc_hash32_pp_prot(key, pp, 0);
154 }
155 
156 static hwaddr ppc_hash32_bat_lookup(PowerPCCPU *cpu, target_ulong ea,
157                                     MMUAccessType access_type, int *prot)
158 {
159     CPUPPCState *env = &cpu->env;
160     target_ulong *BATlt, *BATut;
161     bool ifetch = access_type == MMU_INST_FETCH;
162     int i;
163 
164     LOG_BATS("%s: %cBAT v " TARGET_FMT_lx "\n", __func__,
165              ifetch ? 'I' : 'D', ea);
166     if (ifetch) {
167         BATlt = env->IBAT[1];
168         BATut = env->IBAT[0];
169     } else {
170         BATlt = env->DBAT[1];
171         BATut = env->DBAT[0];
172     }
173     for (i = 0; i < env->nb_BATs; i++) {
174         target_ulong batu = BATut[i];
175         target_ulong batl = BATlt[i];
176         target_ulong mask;
177 
178         if (unlikely(env->mmu_model == POWERPC_MMU_601)) {
179             mask = hash32_bat_601_size(cpu, batu, batl);
180         } else {
181             mask = hash32_bat_size(cpu, batu, batl);
182         }
183         LOG_BATS("%s: %cBAT%d v " TARGET_FMT_lx " BATu " TARGET_FMT_lx
184                  " BATl " TARGET_FMT_lx "\n", __func__,
185                  ifetch ? 'I' : 'D', i, ea, batu, batl);
186 
187         if (mask && ((ea & mask) == (batu & BATU32_BEPI))) {
188             hwaddr raddr = (batl & mask) | (ea & ~mask);
189 
190             if (unlikely(env->mmu_model == POWERPC_MMU_601)) {
191                 *prot = hash32_bat_601_prot(cpu, batu, batl);
192             } else {
193                 *prot = hash32_bat_prot(cpu, batu, batl);
194             }
195 
196             return raddr & TARGET_PAGE_MASK;
197         }
198     }
199 
200     /* No hit */
201 #if defined(DEBUG_BATS)
202     if (qemu_log_enabled()) {
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 int ppc_hash32_direct_store(PowerPCCPU *cpu, target_ulong sr,
223                                    target_ulong eaddr,
224                                    MMUAccessType access_type,
225                                    hwaddr *raddr, int *prot)
226 {
227     CPUState *cs = CPU(cpu);
228     CPUPPCState *env = &cpu->env;
229     int key = !!(msr_pr ? (sr & SR32_KP) : (sr & SR32_KS));
230 
231     qemu_log_mask(CPU_LOG_MMU, "direct store...\n");
232 
233     if ((sr & 0x1FF00000) >> 20 == 0x07f) {
234         /*
235          * Memory-forced I/O controller interface access
236          *
237          * If T=1 and BUID=x'07F', the 601 performs a memory access
238          * to SR[28-31] LA[4-31], bypassing all protection mechanisms.
239          */
240         *raddr = ((sr & 0xF) << 28) | (eaddr & 0x0FFFFFFF);
241         *prot = PAGE_READ | PAGE_WRITE | PAGE_EXEC;
242         return 0;
243     }
244 
245     if (access_type == MMU_INST_FETCH) {
246         /* No code fetch is allowed in direct-store areas */
247         cs->exception_index = POWERPC_EXCP_ISI;
248         env->error_code = 0x10000000;
249         return 1;
250     }
251 
252     switch (env->access_type) {
253     case ACCESS_INT:
254         /* Integer load/store : only access allowed */
255         break;
256     case ACCESS_FLOAT:
257         /* Floating point load/store */
258         cs->exception_index = POWERPC_EXCP_ALIGN;
259         env->error_code = POWERPC_EXCP_ALIGN_FP;
260         env->spr[SPR_DAR] = eaddr;
261         return 1;
262     case ACCESS_RES:
263         /* lwarx, ldarx or srwcx. */
264         env->error_code = 0;
265         env->spr[SPR_DAR] = eaddr;
266         if (access_type == MMU_DATA_STORE) {
267             env->spr[SPR_DSISR] = 0x06000000;
268         } else {
269             env->spr[SPR_DSISR] = 0x04000000;
270         }
271         return 1;
272     case ACCESS_CACHE:
273         /*
274          * dcba, dcbt, dcbtst, dcbf, dcbi, dcbst, dcbz, or icbi
275          *
276          * Should make the instruction do no-op.  As it already do
277          * no-op, it's quite easy :-)
278          */
279         *raddr = eaddr;
280         return 0;
281     case ACCESS_EXT:
282         /* eciwx or ecowx */
283         cs->exception_index = POWERPC_EXCP_DSI;
284         env->error_code = 0;
285         env->spr[SPR_DAR] = eaddr;
286         if (access_type == MMU_DATA_STORE) {
287             env->spr[SPR_DSISR] = 0x06100000;
288         } else {
289             env->spr[SPR_DSISR] = 0x04100000;
290         }
291         return 1;
292     default:
293         cpu_abort(cs, "ERROR: instruction should not need "
294                  "address translation\n");
295     }
296     if ((access_type == MMU_DATA_STORE || key != 1) &&
297         (access_type == MMU_DATA_LOAD || key != 0)) {
298         *raddr = eaddr;
299         return 0;
300     } else {
301         cs->exception_index = POWERPC_EXCP_DSI;
302         env->error_code = 0;
303         env->spr[SPR_DAR] = eaddr;
304         if (access_type == MMU_DATA_STORE) {
305             env->spr[SPR_DSISR] = 0x0a000000;
306         } else {
307             env->spr[SPR_DSISR] = 0x08000000;
308         }
309         return 1;
310     }
311 }
312 
313 hwaddr get_pteg_offset32(PowerPCCPU *cpu, hwaddr hash)
314 {
315     target_ulong mask = ppc_hash32_hpt_mask(cpu);
316 
317     return (hash * HASH_PTEG_SIZE_32) & mask;
318 }
319 
320 static hwaddr ppc_hash32_pteg_search(PowerPCCPU *cpu, hwaddr pteg_off,
321                                      bool secondary, target_ulong ptem,
322                                      ppc_hash_pte32_t *pte)
323 {
324     hwaddr pte_offset = pteg_off;
325     target_ulong pte0, pte1;
326     int i;
327 
328     for (i = 0; i < HPTES_PER_GROUP; i++) {
329         pte0 = ppc_hash32_load_hpte0(cpu, pte_offset);
330         /*
331          * pte0 contains the valid bit and must be read before pte1,
332          * otherwise we might see an old pte1 with a new valid bit and
333          * thus an inconsistent hpte value
334          */
335         smp_rmb();
336         pte1 = ppc_hash32_load_hpte1(cpu, pte_offset);
337 
338         if ((pte0 & HPTE32_V_VALID)
339             && (secondary == !!(pte0 & HPTE32_V_SECONDARY))
340             && HPTE32_V_COMPARE(pte0, ptem)) {
341             pte->pte0 = pte0;
342             pte->pte1 = pte1;
343             return pte_offset;
344         }
345 
346         pte_offset += HASH_PTE_SIZE_32;
347     }
348 
349     return -1;
350 }
351 
352 static void ppc_hash32_set_r(PowerPCCPU *cpu, hwaddr pte_offset, uint32_t pte1)
353 {
354     target_ulong base = ppc_hash32_hpt_base(cpu);
355     hwaddr offset = pte_offset + 6;
356 
357     /* The HW performs a non-atomic byte update */
358     stb_phys(CPU(cpu)->as, base + offset, ((pte1 >> 8) & 0xff) | 0x01);
359 }
360 
361 static void ppc_hash32_set_c(PowerPCCPU *cpu, hwaddr pte_offset, uint64_t pte1)
362 {
363     target_ulong base = ppc_hash32_hpt_base(cpu);
364     hwaddr offset = pte_offset + 7;
365 
366     /* The HW performs a non-atomic byte update */
367     stb_phys(CPU(cpu)->as, base + offset, (pte1 & 0xff) | 0x80);
368 }
369 
370 static hwaddr ppc_hash32_htab_lookup(PowerPCCPU *cpu,
371                                      target_ulong sr, target_ulong eaddr,
372                                      ppc_hash_pte32_t *pte)
373 {
374     hwaddr pteg_off, pte_offset;
375     hwaddr hash;
376     uint32_t vsid, pgidx, ptem;
377 
378     vsid = sr & SR32_VSID;
379     pgidx = (eaddr & ~SEGMENT_MASK_256M) >> TARGET_PAGE_BITS;
380     hash = vsid ^ pgidx;
381     ptem = (vsid << 7) | (pgidx >> 10);
382 
383     /* Page address translation */
384     qemu_log_mask(CPU_LOG_MMU, "htab_base " TARGET_FMT_plx
385             " htab_mask " TARGET_FMT_plx
386             " hash " TARGET_FMT_plx "\n",
387             ppc_hash32_hpt_base(cpu), ppc_hash32_hpt_mask(cpu), hash);
388 
389     /* Primary PTEG lookup */
390     qemu_log_mask(CPU_LOG_MMU, "0 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
391             " vsid=%" PRIx32 " ptem=%" PRIx32
392             " hash=" TARGET_FMT_plx "\n",
393             ppc_hash32_hpt_base(cpu), ppc_hash32_hpt_mask(cpu),
394             vsid, ptem, hash);
395     pteg_off = get_pteg_offset32(cpu, hash);
396     pte_offset = ppc_hash32_pteg_search(cpu, pteg_off, 0, ptem, pte);
397     if (pte_offset == -1) {
398         /* Secondary PTEG lookup */
399         qemu_log_mask(CPU_LOG_MMU, "1 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
400                 " vsid=%" PRIx32 " api=%" PRIx32
401                 " hash=" TARGET_FMT_plx "\n", ppc_hash32_hpt_base(cpu),
402                 ppc_hash32_hpt_mask(cpu), vsid, ptem, ~hash);
403         pteg_off = get_pteg_offset32(cpu, ~hash);
404         pte_offset = ppc_hash32_pteg_search(cpu, pteg_off, 1, ptem, pte);
405     }
406 
407     return pte_offset;
408 }
409 
410 static hwaddr ppc_hash32_pte_raddr(target_ulong sr, ppc_hash_pte32_t pte,
411                                    target_ulong eaddr)
412 {
413     hwaddr rpn = pte.pte1 & HPTE32_R_RPN;
414     hwaddr mask = ~TARGET_PAGE_MASK;
415 
416     return (rpn & ~mask) | (eaddr & mask);
417 }
418 
419 int ppc_hash32_handle_mmu_fault(PowerPCCPU *cpu, vaddr eaddr, int rwx,
420                                 int mmu_idx)
421 {
422     CPUState *cs = CPU(cpu);
423     CPUPPCState *env = &cpu->env;
424     target_ulong sr;
425     hwaddr pte_offset;
426     ppc_hash_pte32_t pte;
427     int prot;
428     int need_prot;
429     MMUAccessType access_type;
430     hwaddr raddr;
431 
432     assert((rwx == 0) || (rwx == 1) || (rwx == 2));
433     access_type = rwx;
434     need_prot = prot_for_access_type(access_type);
435 
436     /* 1. Handle real mode accesses */
437     if (access_type == MMU_INST_FETCH ? !msr_ir : !msr_dr) {
438         /* Translation is off */
439         raddr = eaddr;
440         tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
441                      PAGE_READ | PAGE_WRITE | PAGE_EXEC, mmu_idx,
442                      TARGET_PAGE_SIZE);
443         return 0;
444     }
445 
446     /* 2. Check Block Address Translation entries (BATs) */
447     if (env->nb_BATs != 0) {
448         raddr = ppc_hash32_bat_lookup(cpu, eaddr, access_type, &prot);
449         if (raddr != -1) {
450             if (need_prot & ~prot) {
451                 if (access_type == MMU_INST_FETCH) {
452                     cs->exception_index = POWERPC_EXCP_ISI;
453                     env->error_code = 0x08000000;
454                 } else {
455                     cs->exception_index = POWERPC_EXCP_DSI;
456                     env->error_code = 0;
457                     env->spr[SPR_DAR] = eaddr;
458                     if (access_type == MMU_DATA_STORE) {
459                         env->spr[SPR_DSISR] = 0x0a000000;
460                     } else {
461                         env->spr[SPR_DSISR] = 0x08000000;
462                     }
463                 }
464                 return 1;
465             }
466 
467             tlb_set_page(cs, eaddr & TARGET_PAGE_MASK,
468                          raddr & TARGET_PAGE_MASK, prot, mmu_idx,
469                          TARGET_PAGE_SIZE);
470             return 0;
471         }
472     }
473 
474     /* 3. Look up the Segment Register */
475     sr = env->sr[eaddr >> 28];
476 
477     /* 4. Handle direct store segments */
478     if (sr & SR32_T) {
479         if (ppc_hash32_direct_store(cpu, sr, eaddr, access_type,
480                                     &raddr, &prot) == 0) {
481             tlb_set_page(cs, eaddr & TARGET_PAGE_MASK,
482                          raddr & TARGET_PAGE_MASK, prot, mmu_idx,
483                          TARGET_PAGE_SIZE);
484             return 0;
485         } else {
486             return 1;
487         }
488     }
489 
490     /* 5. Check for segment level no-execute violation */
491     if (access_type == MMU_INST_FETCH && (sr & SR32_NX)) {
492         cs->exception_index = POWERPC_EXCP_ISI;
493         env->error_code = 0x10000000;
494         return 1;
495     }
496 
497     /* 6. Locate the PTE in the hash table */
498     pte_offset = ppc_hash32_htab_lookup(cpu, sr, eaddr, &pte);
499     if (pte_offset == -1) {
500         if (access_type == MMU_INST_FETCH) {
501             cs->exception_index = POWERPC_EXCP_ISI;
502             env->error_code = 0x40000000;
503         } else {
504             cs->exception_index = POWERPC_EXCP_DSI;
505             env->error_code = 0;
506             env->spr[SPR_DAR] = eaddr;
507             if (access_type == MMU_DATA_STORE) {
508                 env->spr[SPR_DSISR] = 0x42000000;
509             } else {
510                 env->spr[SPR_DSISR] = 0x40000000;
511             }
512         }
513 
514         return 1;
515     }
516     qemu_log_mask(CPU_LOG_MMU,
517                 "found PTE at offset %08" HWADDR_PRIx "\n", pte_offset);
518 
519     /* 7. Check access permissions */
520 
521     prot = ppc_hash32_pte_prot(cpu, sr, pte);
522 
523     if (need_prot & ~prot) {
524         /* Access right violation */
525         qemu_log_mask(CPU_LOG_MMU, "PTE access rejected\n");
526         if (access_type == MMU_INST_FETCH) {
527             cs->exception_index = POWERPC_EXCP_ISI;
528             env->error_code = 0x08000000;
529         } else {
530             cs->exception_index = POWERPC_EXCP_DSI;
531             env->error_code = 0;
532             env->spr[SPR_DAR] = eaddr;
533             if (access_type == MMU_DATA_STORE) {
534                 env->spr[SPR_DSISR] = 0x0a000000;
535             } else {
536                 env->spr[SPR_DSISR] = 0x08000000;
537             }
538         }
539         return 1;
540     }
541 
542     qemu_log_mask(CPU_LOG_MMU, "PTE access granted !\n");
543 
544     /* 8. Update PTE referenced and changed bits if necessary */
545 
546     if (!(pte.pte1 & HPTE32_R_R)) {
547         ppc_hash32_set_r(cpu, pte_offset, pte.pte1);
548     }
549     if (!(pte.pte1 & HPTE32_R_C)) {
550         if (access_type == MMU_DATA_STORE) {
551             ppc_hash32_set_c(cpu, pte_offset, pte.pte1);
552         } else {
553             /*
554              * Treat the page as read-only for now, so that a later write
555              * will pass through this function again to set the C bit
556              */
557             prot &= ~PAGE_WRITE;
558         }
559      }
560 
561     /* 9. Determine the real address from the PTE */
562 
563     raddr = ppc_hash32_pte_raddr(sr, pte, eaddr);
564 
565     tlb_set_page(cs, eaddr & TARGET_PAGE_MASK, raddr & TARGET_PAGE_MASK,
566                  prot, mmu_idx, TARGET_PAGE_SIZE);
567 
568     return 0;
569 }
570 
571 hwaddr ppc_hash32_get_phys_page_debug(PowerPCCPU *cpu, target_ulong eaddr)
572 {
573     CPUPPCState *env = &cpu->env;
574     target_ulong sr;
575     hwaddr pte_offset;
576     ppc_hash_pte32_t pte;
577     int prot;
578 
579     if (msr_dr == 0) {
580         /* Translation is off */
581         return eaddr;
582     }
583 
584     if (env->nb_BATs != 0) {
585         hwaddr raddr = ppc_hash32_bat_lookup(cpu, eaddr, 0, &prot);
586         if (raddr != -1) {
587             return raddr;
588         }
589     }
590 
591     sr = env->sr[eaddr >> 28];
592 
593     if (sr & SR32_T) {
594         /* FIXME: Add suitable debug support for Direct Store segments */
595         return -1;
596     }
597 
598     pte_offset = ppc_hash32_htab_lookup(cpu, sr, eaddr, &pte);
599     if (pte_offset == -1) {
600         return -1;
601     }
602 
603     return ppc_hash32_pte_raddr(sr, pte, eaddr) & TARGET_PAGE_MASK;
604 }
605