xref: /openbmc/qemu/target/ppc/mem_helper.c (revision 06831001)
1 /*
2  *  PowerPC memory access emulation helpers for QEMU.
3  *
4  *  Copyright (c) 2003-2007 Jocelyn Mayer
5  *
6  * This library is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * This library is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #include "qemu/osdep.h"
21 #include "cpu.h"
22 #include "exec/exec-all.h"
23 #include "qemu/host-utils.h"
24 #include "qemu/main-loop.h"
25 #include "exec/helper-proto.h"
26 #include "helper_regs.h"
27 #include "exec/cpu_ldst.h"
28 #include "internal.h"
29 #include "qemu/atomic128.h"
30 
31 /* #define DEBUG_OP */
32 
33 static inline bool needs_byteswap(const CPUPPCState *env)
34 {
35 #if TARGET_BIG_ENDIAN
36   return FIELD_EX64(env->msr, MSR, LE);
37 #else
38   return !FIELD_EX64(env->msr, MSR, LE);
39 #endif
40 }
41 
42 /*****************************************************************************/
43 /* Memory load and stores */
44 
45 static inline target_ulong addr_add(CPUPPCState *env, target_ulong addr,
46                                     target_long arg)
47 {
48 #if defined(TARGET_PPC64)
49     if (!msr_is_64bit(env, env->msr)) {
50         return (uint32_t)(addr + arg);
51     } else
52 #endif
53     {
54         return addr + arg;
55     }
56 }
57 
58 static void *probe_contiguous(CPUPPCState *env, target_ulong addr, uint32_t nb,
59                               MMUAccessType access_type, int mmu_idx,
60                               uintptr_t raddr)
61 {
62     void *host1, *host2;
63     uint32_t nb_pg1, nb_pg2;
64 
65     nb_pg1 = -(addr | TARGET_PAGE_MASK);
66     if (likely(nb <= nb_pg1)) {
67         /* The entire operation is on a single page.  */
68         return probe_access(env, addr, nb, access_type, mmu_idx, raddr);
69     }
70 
71     /* The operation spans two pages.  */
72     nb_pg2 = nb - nb_pg1;
73     host1 = probe_access(env, addr, nb_pg1, access_type, mmu_idx, raddr);
74     addr = addr_add(env, addr, nb_pg1);
75     host2 = probe_access(env, addr, nb_pg2, access_type, mmu_idx, raddr);
76 
77     /* If the two host pages are contiguous, optimize.  */
78     if (host2 == host1 + nb_pg1) {
79         return host1;
80     }
81     return NULL;
82 }
83 
84 void helper_lmw(CPUPPCState *env, target_ulong addr, uint32_t reg)
85 {
86     uintptr_t raddr = GETPC();
87     int mmu_idx = cpu_mmu_index(env, false);
88     void *host = probe_contiguous(env, addr, (32 - reg) * 4,
89                                   MMU_DATA_LOAD, mmu_idx, raddr);
90 
91     if (likely(host)) {
92         /* Fast path -- the entire operation is in RAM at host.  */
93         for (; reg < 32; reg++) {
94             env->gpr[reg] = (uint32_t)ldl_be_p(host);
95             host += 4;
96         }
97     } else {
98         /* Slow path -- at least some of the operation requires i/o.  */
99         for (; reg < 32; reg++) {
100             env->gpr[reg] = cpu_ldl_mmuidx_ra(env, addr, mmu_idx, raddr);
101             addr = addr_add(env, addr, 4);
102         }
103     }
104 }
105 
106 void helper_stmw(CPUPPCState *env, target_ulong addr, uint32_t reg)
107 {
108     uintptr_t raddr = GETPC();
109     int mmu_idx = cpu_mmu_index(env, false);
110     void *host = probe_contiguous(env, addr, (32 - reg) * 4,
111                                   MMU_DATA_STORE, mmu_idx, raddr);
112 
113     if (likely(host)) {
114         /* Fast path -- the entire operation is in RAM at host.  */
115         for (; reg < 32; reg++) {
116             stl_be_p(host, env->gpr[reg]);
117             host += 4;
118         }
119     } else {
120         /* Slow path -- at least some of the operation requires i/o.  */
121         for (; reg < 32; reg++) {
122             cpu_stl_mmuidx_ra(env, addr, env->gpr[reg], mmu_idx, raddr);
123             addr = addr_add(env, addr, 4);
124         }
125     }
126 }
127 
128 static void do_lsw(CPUPPCState *env, target_ulong addr, uint32_t nb,
129                    uint32_t reg, uintptr_t raddr)
130 {
131     int mmu_idx;
132     void *host;
133     uint32_t val;
134 
135     if (unlikely(nb == 0)) {
136         return;
137     }
138 
139     mmu_idx = cpu_mmu_index(env, false);
140     host = probe_contiguous(env, addr, nb, MMU_DATA_LOAD, mmu_idx, raddr);
141 
142     if (likely(host)) {
143         /* Fast path -- the entire operation is in RAM at host.  */
144         for (; nb > 3; nb -= 4) {
145             env->gpr[reg] = (uint32_t)ldl_be_p(host);
146             reg = (reg + 1) % 32;
147             host += 4;
148         }
149         switch (nb) {
150         default:
151             return;
152         case 1:
153             val = ldub_p(host) << 24;
154             break;
155         case 2:
156             val = lduw_be_p(host) << 16;
157             break;
158         case 3:
159             val = (lduw_be_p(host) << 16) | (ldub_p(host + 2) << 8);
160             break;
161         }
162     } else {
163         /* Slow path -- at least some of the operation requires i/o.  */
164         for (; nb > 3; nb -= 4) {
165             env->gpr[reg] = cpu_ldl_mmuidx_ra(env, addr, mmu_idx, raddr);
166             reg = (reg + 1) % 32;
167             addr = addr_add(env, addr, 4);
168         }
169         switch (nb) {
170         default:
171             return;
172         case 1:
173             val = cpu_ldub_mmuidx_ra(env, addr, mmu_idx, raddr) << 24;
174             break;
175         case 2:
176             val = cpu_lduw_mmuidx_ra(env, addr, mmu_idx, raddr) << 16;
177             break;
178         case 3:
179             val = cpu_lduw_mmuidx_ra(env, addr, mmu_idx, raddr) << 16;
180             addr = addr_add(env, addr, 2);
181             val |= cpu_ldub_mmuidx_ra(env, addr, mmu_idx, raddr) << 8;
182             break;
183         }
184     }
185     env->gpr[reg] = val;
186 }
187 
188 void helper_lsw(CPUPPCState *env, target_ulong addr,
189                 uint32_t nb, uint32_t reg)
190 {
191     do_lsw(env, addr, nb, reg, GETPC());
192 }
193 
194 /*
195  * PPC32 specification says we must generate an exception if rA is in
196  * the range of registers to be loaded.  In an other hand, IBM says
197  * this is valid, but rA won't be loaded.  For now, I'll follow the
198  * spec...
199  */
200 void helper_lswx(CPUPPCState *env, target_ulong addr, uint32_t reg,
201                  uint32_t ra, uint32_t rb)
202 {
203     if (likely(xer_bc != 0)) {
204         int num_used_regs = DIV_ROUND_UP(xer_bc, 4);
205         if (unlikely((ra != 0 && lsw_reg_in_range(reg, num_used_regs, ra)) ||
206                      lsw_reg_in_range(reg, num_used_regs, rb))) {
207             raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
208                                    POWERPC_EXCP_INVAL |
209                                    POWERPC_EXCP_INVAL_LSWX, GETPC());
210         } else {
211             do_lsw(env, addr, xer_bc, reg, GETPC());
212         }
213     }
214 }
215 
216 void helper_stsw(CPUPPCState *env, target_ulong addr, uint32_t nb,
217                  uint32_t reg)
218 {
219     uintptr_t raddr = GETPC();
220     int mmu_idx;
221     void *host;
222     uint32_t val;
223 
224     if (unlikely(nb == 0)) {
225         return;
226     }
227 
228     mmu_idx = cpu_mmu_index(env, false);
229     host = probe_contiguous(env, addr, nb, MMU_DATA_STORE, mmu_idx, raddr);
230 
231     if (likely(host)) {
232         /* Fast path -- the entire operation is in RAM at host.  */
233         for (; nb > 3; nb -= 4) {
234             stl_be_p(host, env->gpr[reg]);
235             reg = (reg + 1) % 32;
236             host += 4;
237         }
238         val = env->gpr[reg];
239         switch (nb) {
240         case 1:
241             stb_p(host, val >> 24);
242             break;
243         case 2:
244             stw_be_p(host, val >> 16);
245             break;
246         case 3:
247             stw_be_p(host, val >> 16);
248             stb_p(host + 2, val >> 8);
249             break;
250         }
251     } else {
252         for (; nb > 3; nb -= 4) {
253             cpu_stl_mmuidx_ra(env, addr, env->gpr[reg], mmu_idx, raddr);
254             reg = (reg + 1) % 32;
255             addr = addr_add(env, addr, 4);
256         }
257         val = env->gpr[reg];
258         switch (nb) {
259         case 1:
260             cpu_stb_mmuidx_ra(env, addr, val >> 24, mmu_idx, raddr);
261             break;
262         case 2:
263             cpu_stw_mmuidx_ra(env, addr, val >> 16, mmu_idx, raddr);
264             break;
265         case 3:
266             cpu_stw_mmuidx_ra(env, addr, val >> 16, mmu_idx, raddr);
267             addr = addr_add(env, addr, 2);
268             cpu_stb_mmuidx_ra(env, addr, val >> 8, mmu_idx, raddr);
269             break;
270         }
271     }
272 }
273 
274 static void dcbz_common(CPUPPCState *env, target_ulong addr,
275                         uint32_t opcode, bool epid, uintptr_t retaddr)
276 {
277     target_ulong mask, dcbz_size = env->dcache_line_size;
278     uint32_t i;
279     void *haddr;
280     int mmu_idx = epid ? PPC_TLB_EPID_STORE : cpu_mmu_index(env, false);
281 
282 #if defined(TARGET_PPC64)
283     /* Check for dcbz vs dcbzl on 970 */
284     if (env->excp_model == POWERPC_EXCP_970 &&
285         !(opcode & 0x00200000) && ((env->spr[SPR_970_HID5] >> 7) & 0x3) == 1) {
286         dcbz_size = 32;
287     }
288 #endif
289 
290     /* Align address */
291     mask = ~(dcbz_size - 1);
292     addr &= mask;
293 
294     /* Check reservation */
295     if ((env->reserve_addr & mask) == addr)  {
296         env->reserve_addr = (target_ulong)-1ULL;
297     }
298 
299     /* Try fast path translate */
300     haddr = probe_write(env, addr, dcbz_size, mmu_idx, retaddr);
301     if (haddr) {
302         memset(haddr, 0, dcbz_size);
303     } else {
304         /* Slow path */
305         for (i = 0; i < dcbz_size; i += 8) {
306             cpu_stq_mmuidx_ra(env, addr + i, 0, mmu_idx, retaddr);
307         }
308     }
309 }
310 
311 void helper_dcbz(CPUPPCState *env, target_ulong addr, uint32_t opcode)
312 {
313     dcbz_common(env, addr, opcode, false, GETPC());
314 }
315 
316 void helper_dcbzep(CPUPPCState *env, target_ulong addr, uint32_t opcode)
317 {
318     dcbz_common(env, addr, opcode, true, GETPC());
319 }
320 
321 void helper_icbi(CPUPPCState *env, target_ulong addr)
322 {
323     addr &= ~(env->dcache_line_size - 1);
324     /*
325      * Invalidate one cache line :
326      * PowerPC specification says this is to be treated like a load
327      * (not a fetch) by the MMU. To be sure it will be so,
328      * do the load "by hand".
329      */
330     cpu_ldl_data_ra(env, addr, GETPC());
331 }
332 
333 void helper_icbiep(CPUPPCState *env, target_ulong addr)
334 {
335 #if !defined(CONFIG_USER_ONLY)
336     /* See comments above */
337     addr &= ~(env->dcache_line_size - 1);
338     cpu_ldl_mmuidx_ra(env, addr, PPC_TLB_EPID_LOAD, GETPC());
339 #endif
340 }
341 
342 /* XXX: to be tested */
343 target_ulong helper_lscbx(CPUPPCState *env, target_ulong addr, uint32_t reg,
344                           uint32_t ra, uint32_t rb)
345 {
346     int i, c, d;
347 
348     d = 24;
349     for (i = 0; i < xer_bc; i++) {
350         c = cpu_ldub_data_ra(env, addr, GETPC());
351         addr = addr_add(env, addr, 1);
352         /* ra (if not 0) and rb are never modified */
353         if (likely(reg != rb && (ra == 0 || reg != ra))) {
354             env->gpr[reg] = (env->gpr[reg] & ~(0xFF << d)) | (c << d);
355         }
356         if (unlikely(c == xer_cmp)) {
357             break;
358         }
359         if (likely(d != 0)) {
360             d -= 8;
361         } else {
362             d = 24;
363             reg++;
364             reg = reg & 0x1F;
365         }
366     }
367     return i;
368 }
369 
370 /*****************************************************************************/
371 /* Altivec extension helpers */
372 #if HOST_BIG_ENDIAN
373 #define HI_IDX 0
374 #define LO_IDX 1
375 #else
376 #define HI_IDX 1
377 #define LO_IDX 0
378 #endif
379 
380 /*
381  * We use MSR_LE to determine index ordering in a vector.  However,
382  * byteswapping is not simply controlled by MSR_LE.  We also need to
383  * take into account endianness of the target.  This is done for the
384  * little-endian PPC64 user-mode target.
385  */
386 
387 #define LVE(name, access, swap, element)                        \
388     void helper_##name(CPUPPCState *env, ppc_avr_t *r,          \
389                        target_ulong addr)                       \
390     {                                                           \
391         size_t n_elems = ARRAY_SIZE(r->element);                \
392         int adjust = HI_IDX * (n_elems - 1);                    \
393         int sh = sizeof(r->element[0]) >> 1;                    \
394         int index = (addr & 0xf) >> sh;                         \
395         if (FIELD_EX64(env->msr, MSR, LE)) {                    \
396             index = n_elems - index - 1;                        \
397         }                                                       \
398                                                                 \
399         if (needs_byteswap(env)) {                              \
400             r->element[LO_IDX ? index : (adjust - index)] =     \
401                 swap(access(env, addr, GETPC()));               \
402         } else {                                                \
403             r->element[LO_IDX ? index : (adjust - index)] =     \
404                 access(env, addr, GETPC());                     \
405         }                                                       \
406     }
407 #define I(x) (x)
408 LVE(lvebx, cpu_ldub_data_ra, I, u8)
409 LVE(lvehx, cpu_lduw_data_ra, bswap16, u16)
410 LVE(lvewx, cpu_ldl_data_ra, bswap32, u32)
411 #undef I
412 #undef LVE
413 
414 #define STVE(name, access, swap, element)                               \
415     void helper_##name(CPUPPCState *env, ppc_avr_t *r,                  \
416                        target_ulong addr)                               \
417     {                                                                   \
418         size_t n_elems = ARRAY_SIZE(r->element);                        \
419         int adjust = HI_IDX * (n_elems - 1);                            \
420         int sh = sizeof(r->element[0]) >> 1;                            \
421         int index = (addr & 0xf) >> sh;                                 \
422         if (FIELD_EX64(env->msr, MSR, LE)) {                            \
423             index = n_elems - index - 1;                                \
424         }                                                               \
425                                                                         \
426         if (needs_byteswap(env)) {                                      \
427             access(env, addr, swap(r->element[LO_IDX ? index :          \
428                                               (adjust - index)]),       \
429                         GETPC());                                       \
430         } else {                                                        \
431             access(env, addr, r->element[LO_IDX ? index :               \
432                                          (adjust - index)], GETPC());   \
433         }                                                               \
434     }
435 #define I(x) (x)
436 STVE(stvebx, cpu_stb_data_ra, I, u8)
437 STVE(stvehx, cpu_stw_data_ra, bswap16, u16)
438 STVE(stvewx, cpu_stl_data_ra, bswap32, u32)
439 #undef I
440 #undef LVE
441 
442 #ifdef TARGET_PPC64
443 #define GET_NB(rb) ((rb >> 56) & 0xFF)
444 
445 #define VSX_LXVL(name, lj)                                              \
446 void helper_##name(CPUPPCState *env, target_ulong addr,                 \
447                    ppc_vsr_t *xt, target_ulong rb)                      \
448 {                                                                       \
449     ppc_vsr_t t;                                                        \
450     uint64_t nb = GET_NB(rb);                                           \
451     int i;                                                              \
452                                                                         \
453     t.s128 = int128_zero();                                             \
454     if (nb) {                                                           \
455         nb = (nb >= 16) ? 16 : nb;                                      \
456         if (FIELD_EX64(env->msr, MSR, LE) && !lj) {                     \
457             for (i = 16; i > 16 - nb; i--) {                            \
458                 t.VsrB(i - 1) = cpu_ldub_data_ra(env, addr, GETPC());   \
459                 addr = addr_add(env, addr, 1);                          \
460             }                                                           \
461         } else {                                                        \
462             for (i = 0; i < nb; i++) {                                  \
463                 t.VsrB(i) = cpu_ldub_data_ra(env, addr, GETPC());       \
464                 addr = addr_add(env, addr, 1);                          \
465             }                                                           \
466         }                                                               \
467     }                                                                   \
468     *xt = t;                                                            \
469 }
470 
471 VSX_LXVL(lxvl, 0)
472 VSX_LXVL(lxvll, 1)
473 #undef VSX_LXVL
474 
475 #define VSX_STXVL(name, lj)                                       \
476 void helper_##name(CPUPPCState *env, target_ulong addr,           \
477                    ppc_vsr_t *xt, target_ulong rb)                \
478 {                                                                 \
479     target_ulong nb = GET_NB(rb);                                 \
480     int i;                                                        \
481                                                                   \
482     if (!nb) {                                                    \
483         return;                                                   \
484     }                                                             \
485                                                                   \
486     nb = (nb >= 16) ? 16 : nb;                                    \
487     if (FIELD_EX64(env->msr, MSR, LE) && !lj) {                   \
488         for (i = 16; i > 16 - nb; i--) {                          \
489             cpu_stb_data_ra(env, addr, xt->VsrB(i - 1), GETPC()); \
490             addr = addr_add(env, addr, 1);                        \
491         }                                                         \
492     } else {                                                      \
493         for (i = 0; i < nb; i++) {                                \
494             cpu_stb_data_ra(env, addr, xt->VsrB(i), GETPC());     \
495             addr = addr_add(env, addr, 1);                        \
496         }                                                         \
497     }                                                             \
498 }
499 
500 VSX_STXVL(stxvl, 0)
501 VSX_STXVL(stxvll, 1)
502 #undef VSX_STXVL
503 #undef GET_NB
504 #endif /* TARGET_PPC64 */
505 
506 #undef HI_IDX
507 #undef LO_IDX
508 
509 void helper_tbegin(CPUPPCState *env)
510 {
511     /*
512      * As a degenerate implementation, always fail tbegin.  The reason
513      * given is "Nesting overflow".  The "persistent" bit is set,
514      * providing a hint to the error handler to not retry.  The TFIAR
515      * captures the address of the failure, which is this tbegin
516      * instruction.  Instruction execution will continue with the next
517      * instruction in memory, which is precisely what we want.
518      */
519 
520     env->spr[SPR_TEXASR] =
521         (1ULL << TEXASR_FAILURE_PERSISTENT) |
522         (1ULL << TEXASR_NESTING_OVERFLOW) |
523         (FIELD_EX64_HV(env->msr) << TEXASR_PRIVILEGE_HV) |
524         (FIELD_EX64(env->msr, MSR, PR) << TEXASR_PRIVILEGE_PR) |
525         (1ULL << TEXASR_FAILURE_SUMMARY) |
526         (1ULL << TEXASR_TFIAR_EXACT);
527     env->spr[SPR_TFIAR] = env->nip | (FIELD_EX64_HV(env->msr) << 1) |
528                           FIELD_EX64(env->msr, MSR, PR);
529     env->spr[SPR_TFHAR] = env->nip + 4;
530     env->crf[0] = 0xB; /* 0b1010 = transaction failure */
531 }
532