xref: /openbmc/qemu/target/ppc/mem_helper.c (revision 4921d0a7)
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 "exec/helper-proto.h"
25 #include "helper_regs.h"
26 #include "exec/cpu_ldst.h"
27 #include "internal.h"
28 #include "qemu/atomic128.h"
29 
30 /* #define DEBUG_OP */
31 
32 static inline bool needs_byteswap(const CPUPPCState *env)
33 {
34 #if TARGET_BIG_ENDIAN
35   return FIELD_EX64(env->msr, MSR, LE);
36 #else
37   return !FIELD_EX64(env->msr, MSR, LE);
38 #endif
39 }
40 
41 /*****************************************************************************/
42 /* Memory load and stores */
43 
44 static inline target_ulong addr_add(CPUPPCState *env, target_ulong addr,
45                                     target_long arg)
46 {
47 #if defined(TARGET_PPC64)
48     if (!msr_is_64bit(env, env->msr)) {
49         return (uint32_t)(addr + arg);
50     } else
51 #endif
52     {
53         return addr + arg;
54     }
55 }
56 
57 static void *probe_contiguous(CPUPPCState *env, target_ulong addr, uint32_t nb,
58                               MMUAccessType access_type, int mmu_idx,
59                               uintptr_t raddr)
60 {
61     void *host1, *host2;
62     uint32_t nb_pg1, nb_pg2;
63 
64     nb_pg1 = -(addr | TARGET_PAGE_MASK);
65     if (likely(nb <= nb_pg1)) {
66         /* The entire operation is on a single page.  */
67         return probe_access(env, addr, nb, access_type, mmu_idx, raddr);
68     }
69 
70     /* The operation spans two pages.  */
71     nb_pg2 = nb - nb_pg1;
72     host1 = probe_access(env, addr, nb_pg1, access_type, mmu_idx, raddr);
73     addr = addr_add(env, addr, nb_pg1);
74     host2 = probe_access(env, addr, nb_pg2, access_type, mmu_idx, raddr);
75 
76     /* If the two host pages are contiguous, optimize.  */
77     if (host2 == host1 + nb_pg1) {
78         return host1;
79     }
80     return NULL;
81 }
82 
83 void helper_lmw(CPUPPCState *env, target_ulong addr, uint32_t reg)
84 {
85     uintptr_t raddr = GETPC();
86     int mmu_idx = ppc_env_mmu_index(env, false);
87     void *host = probe_contiguous(env, addr, (32 - reg) * 4,
88                                   MMU_DATA_LOAD, mmu_idx, raddr);
89 
90     if (likely(host)) {
91         /* Fast path -- the entire operation is in RAM at host.  */
92         for (; reg < 32; reg++) {
93             env->gpr[reg] = (uint32_t)ldl_be_p(host);
94             host += 4;
95         }
96     } else {
97         /* Slow path -- at least some of the operation requires i/o.  */
98         for (; reg < 32; reg++) {
99             env->gpr[reg] = cpu_ldl_mmuidx_ra(env, addr, mmu_idx, raddr);
100             addr = addr_add(env, addr, 4);
101         }
102     }
103 }
104 
105 void helper_stmw(CPUPPCState *env, target_ulong addr, uint32_t reg)
106 {
107     uintptr_t raddr = GETPC();
108     int mmu_idx = ppc_env_mmu_index(env, false);
109     void *host = probe_contiguous(env, addr, (32 - reg) * 4,
110                                   MMU_DATA_STORE, mmu_idx, raddr);
111 
112     if (likely(host)) {
113         /* Fast path -- the entire operation is in RAM at host.  */
114         for (; reg < 32; reg++) {
115             stl_be_p(host, env->gpr[reg]);
116             host += 4;
117         }
118     } else {
119         /* Slow path -- at least some of the operation requires i/o.  */
120         for (; reg < 32; reg++) {
121             cpu_stl_mmuidx_ra(env, addr, env->gpr[reg], mmu_idx, raddr);
122             addr = addr_add(env, addr, 4);
123         }
124     }
125 }
126 
127 static void do_lsw(CPUPPCState *env, target_ulong addr, uint32_t nb,
128                    uint32_t reg, uintptr_t raddr)
129 {
130     int mmu_idx;
131     void *host;
132     uint32_t val;
133 
134     if (unlikely(nb == 0)) {
135         return;
136     }
137 
138     mmu_idx = ppc_env_mmu_index(env, false);
139     host = probe_contiguous(env, addr, nb, MMU_DATA_LOAD, mmu_idx, raddr);
140 
141     if (likely(host)) {
142         /* Fast path -- the entire operation is in RAM at host.  */
143         for (; nb > 3; nb -= 4) {
144             env->gpr[reg] = (uint32_t)ldl_be_p(host);
145             reg = (reg + 1) % 32;
146             host += 4;
147         }
148         switch (nb) {
149         default:
150             return;
151         case 1:
152             val = ldub_p(host) << 24;
153             break;
154         case 2:
155             val = lduw_be_p(host) << 16;
156             break;
157         case 3:
158             val = (lduw_be_p(host) << 16) | (ldub_p(host + 2) << 8);
159             break;
160         }
161     } else {
162         /* Slow path -- at least some of the operation requires i/o.  */
163         for (; nb > 3; nb -= 4) {
164             env->gpr[reg] = cpu_ldl_mmuidx_ra(env, addr, mmu_idx, raddr);
165             reg = (reg + 1) % 32;
166             addr = addr_add(env, addr, 4);
167         }
168         switch (nb) {
169         default:
170             return;
171         case 1:
172             val = cpu_ldub_mmuidx_ra(env, addr, mmu_idx, raddr) << 24;
173             break;
174         case 2:
175             val = cpu_lduw_mmuidx_ra(env, addr, mmu_idx, raddr) << 16;
176             break;
177         case 3:
178             val = cpu_lduw_mmuidx_ra(env, addr, mmu_idx, raddr) << 16;
179             addr = addr_add(env, addr, 2);
180             val |= cpu_ldub_mmuidx_ra(env, addr, mmu_idx, raddr) << 8;
181             break;
182         }
183     }
184     env->gpr[reg] = val;
185 }
186 
187 void helper_lsw(CPUPPCState *env, target_ulong addr,
188                 uint32_t nb, uint32_t reg)
189 {
190     do_lsw(env, addr, nb, reg, GETPC());
191 }
192 
193 /*
194  * PPC32 specification says we must generate an exception if rA is in
195  * the range of registers to be loaded.  In an other hand, IBM says
196  * this is valid, but rA won't be loaded.  For now, I'll follow the
197  * spec...
198  */
199 void helper_lswx(CPUPPCState *env, target_ulong addr, uint32_t reg,
200                  uint32_t ra, uint32_t rb)
201 {
202     if (likely(xer_bc != 0)) {
203         int num_used_regs = DIV_ROUND_UP(xer_bc, 4);
204         if (unlikely((ra != 0 && lsw_reg_in_range(reg, num_used_regs, ra)) ||
205                      lsw_reg_in_range(reg, num_used_regs, rb))) {
206             raise_exception_err_ra(env, POWERPC_EXCP_PROGRAM,
207                                    POWERPC_EXCP_INVAL |
208                                    POWERPC_EXCP_INVAL_LSWX, GETPC());
209         } else {
210             do_lsw(env, addr, xer_bc, reg, GETPC());
211         }
212     }
213 }
214 
215 void helper_stsw(CPUPPCState *env, target_ulong addr, uint32_t nb,
216                  uint32_t reg)
217 {
218     uintptr_t raddr = GETPC();
219     int mmu_idx;
220     void *host;
221     uint32_t val;
222 
223     if (unlikely(nb == 0)) {
224         return;
225     }
226 
227     mmu_idx = ppc_env_mmu_index(env, false);
228     host = probe_contiguous(env, addr, nb, MMU_DATA_STORE, mmu_idx, raddr);
229 
230     if (likely(host)) {
231         /* Fast path -- the entire operation is in RAM at host.  */
232         for (; nb > 3; nb -= 4) {
233             stl_be_p(host, env->gpr[reg]);
234             reg = (reg + 1) % 32;
235             host += 4;
236         }
237         val = env->gpr[reg];
238         switch (nb) {
239         case 1:
240             stb_p(host, val >> 24);
241             break;
242         case 2:
243             stw_be_p(host, val >> 16);
244             break;
245         case 3:
246             stw_be_p(host, val >> 16);
247             stb_p(host + 2, val >> 8);
248             break;
249         }
250     } else {
251         for (; nb > 3; nb -= 4) {
252             cpu_stl_mmuidx_ra(env, addr, env->gpr[reg], mmu_idx, raddr);
253             reg = (reg + 1) % 32;
254             addr = addr_add(env, addr, 4);
255         }
256         val = env->gpr[reg];
257         switch (nb) {
258         case 1:
259             cpu_stb_mmuidx_ra(env, addr, val >> 24, mmu_idx, raddr);
260             break;
261         case 2:
262             cpu_stw_mmuidx_ra(env, addr, val >> 16, mmu_idx, raddr);
263             break;
264         case 3:
265             cpu_stw_mmuidx_ra(env, addr, val >> 16, mmu_idx, raddr);
266             addr = addr_add(env, addr, 2);
267             cpu_stb_mmuidx_ra(env, addr, val >> 8, mmu_idx, raddr);
268             break;
269         }
270     }
271 }
272 
273 static void dcbz_common(CPUPPCState *env, target_ulong addr,
274                         uint32_t opcode, bool epid, uintptr_t retaddr)
275 {
276     target_ulong mask, dcbz_size = env->dcache_line_size;
277     uint32_t i;
278     void *haddr;
279     int mmu_idx = epid ? PPC_TLB_EPID_STORE : ppc_env_mmu_index(env, false);
280 
281 #if defined(TARGET_PPC64)
282     /* Check for dcbz vs dcbzl on 970 */
283     if (env->excp_model == POWERPC_EXCP_970 &&
284         !(opcode & 0x00200000) && ((env->spr[SPR_970_HID5] >> 7) & 0x3) == 1) {
285         dcbz_size = 32;
286     }
287 #endif
288 
289     /* Align address */
290     mask = ~(dcbz_size - 1);
291     addr &= mask;
292 
293     /* Check reservation */
294     if ((env->reserve_addr & mask) == addr)  {
295         env->reserve_addr = (target_ulong)-1ULL;
296     }
297 
298     /* Try fast path translate */
299     haddr = probe_write(env, addr, dcbz_size, mmu_idx, retaddr);
300     if (haddr) {
301         memset(haddr, 0, dcbz_size);
302     } else {
303         /* Slow path */
304         for (i = 0; i < dcbz_size; i += 8) {
305             cpu_stq_mmuidx_ra(env, addr + i, 0, mmu_idx, retaddr);
306         }
307     }
308 }
309 
310 void helper_dcbz(CPUPPCState *env, target_ulong addr, uint32_t opcode)
311 {
312     dcbz_common(env, addr, opcode, false, GETPC());
313 }
314 
315 void helper_dcbzep(CPUPPCState *env, target_ulong addr, uint32_t opcode)
316 {
317     dcbz_common(env, addr, opcode, true, GETPC());
318 }
319 
320 void helper_icbi(CPUPPCState *env, target_ulong addr)
321 {
322     addr &= ~(env->dcache_line_size - 1);
323     /*
324      * Invalidate one cache line :
325      * PowerPC specification says this is to be treated like a load
326      * (not a fetch) by the MMU. To be sure it will be so,
327      * do the load "by hand".
328      */
329     cpu_ldl_data_ra(env, addr, GETPC());
330 }
331 
332 void helper_icbiep(CPUPPCState *env, target_ulong addr)
333 {
334 #if !defined(CONFIG_USER_ONLY)
335     /* See comments above */
336     addr &= ~(env->dcache_line_size - 1);
337     cpu_ldl_mmuidx_ra(env, addr, PPC_TLB_EPID_LOAD, GETPC());
338 #endif
339 }
340 
341 /* XXX: to be tested */
342 target_ulong helper_lscbx(CPUPPCState *env, target_ulong addr, uint32_t reg,
343                           uint32_t ra, uint32_t rb)
344 {
345     int i, c, d;
346 
347     d = 24;
348     for (i = 0; i < xer_bc; i++) {
349         c = cpu_ldub_data_ra(env, addr, GETPC());
350         addr = addr_add(env, addr, 1);
351         /* ra (if not 0) and rb are never modified */
352         if (likely(reg != rb && (ra == 0 || reg != ra))) {
353             env->gpr[reg] = (env->gpr[reg] & ~(0xFF << d)) | (c << d);
354         }
355         if (unlikely(c == xer_cmp)) {
356             break;
357         }
358         if (likely(d != 0)) {
359             d -= 8;
360         } else {
361             d = 24;
362             reg++;
363             reg = reg & 0x1F;
364         }
365     }
366     return i;
367 }
368 
369 /*****************************************************************************/
370 /* Altivec extension helpers */
371 #if HOST_BIG_ENDIAN
372 #define HI_IDX 0
373 #define LO_IDX 1
374 #else
375 #define HI_IDX 1
376 #define LO_IDX 0
377 #endif
378 
379 /*
380  * We use MSR_LE to determine index ordering in a vector.  However,
381  * byteswapping is not simply controlled by MSR_LE.  We also need to
382  * take into account endianness of the target.  This is done for the
383  * little-endian PPC64 user-mode target.
384  */
385 
386 #define LVE(name, access, swap, element)                        \
387     void helper_##name(CPUPPCState *env, ppc_avr_t *r,          \
388                        target_ulong addr)                       \
389     {                                                           \
390         size_t n_elems = ARRAY_SIZE(r->element);                \
391         int adjust = HI_IDX * (n_elems - 1);                    \
392         int sh = sizeof(r->element[0]) >> 1;                    \
393         int index = (addr & 0xf) >> sh;                         \
394         if (FIELD_EX64(env->msr, MSR, LE)) {                    \
395             index = n_elems - index - 1;                        \
396         }                                                       \
397                                                                 \
398         if (needs_byteswap(env)) {                              \
399             r->element[LO_IDX ? index : (adjust - index)] =     \
400                 swap(access(env, addr, GETPC()));               \
401         } else {                                                \
402             r->element[LO_IDX ? index : (adjust - index)] =     \
403                 access(env, addr, GETPC());                     \
404         }                                                       \
405     }
406 #define I(x) (x)
407 LVE(lvebx, cpu_ldub_data_ra, I, u8)
408 LVE(lvehx, cpu_lduw_data_ra, bswap16, u16)
409 LVE(lvewx, cpu_ldl_data_ra, bswap32, u32)
410 #undef I
411 #undef LVE
412 
413 #define STVE(name, access, swap, element)                               \
414     void helper_##name(CPUPPCState *env, ppc_avr_t *r,                  \
415                        target_ulong addr)                               \
416     {                                                                   \
417         size_t n_elems = ARRAY_SIZE(r->element);                        \
418         int adjust = HI_IDX * (n_elems - 1);                            \
419         int sh = sizeof(r->element[0]) >> 1;                            \
420         int index = (addr & 0xf) >> sh;                                 \
421         if (FIELD_EX64(env->msr, MSR, LE)) {                            \
422             index = n_elems - index - 1;                                \
423         }                                                               \
424                                                                         \
425         if (needs_byteswap(env)) {                                      \
426             access(env, addr, swap(r->element[LO_IDX ? index :          \
427                                               (adjust - index)]),       \
428                         GETPC());                                       \
429         } else {                                                        \
430             access(env, addr, r->element[LO_IDX ? index :               \
431                                          (adjust - index)], GETPC());   \
432         }                                                               \
433     }
434 #define I(x) (x)
435 STVE(stvebx, cpu_stb_data_ra, I, u8)
436 STVE(stvehx, cpu_stw_data_ra, bswap16, u16)
437 STVE(stvewx, cpu_stl_data_ra, bswap32, u32)
438 #undef I
439 #undef LVE
440 
441 #ifdef TARGET_PPC64
442 #define GET_NB(rb) ((rb >> 56) & 0xFF)
443 
444 #define VSX_LXVL(name, lj)                                              \
445 void helper_##name(CPUPPCState *env, target_ulong addr,                 \
446                    ppc_vsr_t *xt, target_ulong rb)                      \
447 {                                                                       \
448     ppc_vsr_t t;                                                        \
449     uint64_t nb = GET_NB(rb);                                           \
450     int i;                                                              \
451                                                                         \
452     t.s128 = int128_zero();                                             \
453     if (nb) {                                                           \
454         nb = (nb >= 16) ? 16 : nb;                                      \
455         if (FIELD_EX64(env->msr, MSR, LE) && !lj) {                     \
456             for (i = 16; i > 16 - nb; i--) {                            \
457                 t.VsrB(i - 1) = cpu_ldub_data_ra(env, addr, GETPC());   \
458                 addr = addr_add(env, addr, 1);                          \
459             }                                                           \
460         } else {                                                        \
461             for (i = 0; i < nb; i++) {                                  \
462                 t.VsrB(i) = cpu_ldub_data_ra(env, addr, GETPC());       \
463                 addr = addr_add(env, addr, 1);                          \
464             }                                                           \
465         }                                                               \
466     }                                                                   \
467     *xt = t;                                                            \
468 }
469 
470 VSX_LXVL(lxvl, 0)
471 VSX_LXVL(lxvll, 1)
472 #undef VSX_LXVL
473 
474 #define VSX_STXVL(name, lj)                                       \
475 void helper_##name(CPUPPCState *env, target_ulong addr,           \
476                    ppc_vsr_t *xt, target_ulong rb)                \
477 {                                                                 \
478     target_ulong nb = GET_NB(rb);                                 \
479     int i;                                                        \
480                                                                   \
481     if (!nb) {                                                    \
482         return;                                                   \
483     }                                                             \
484                                                                   \
485     nb = (nb >= 16) ? 16 : nb;                                    \
486     if (FIELD_EX64(env->msr, MSR, LE) && !lj) {                   \
487         for (i = 16; i > 16 - nb; i--) {                          \
488             cpu_stb_data_ra(env, addr, xt->VsrB(i - 1), GETPC()); \
489             addr = addr_add(env, addr, 1);                        \
490         }                                                         \
491     } else {                                                      \
492         for (i = 0; i < nb; i++) {                                \
493             cpu_stb_data_ra(env, addr, xt->VsrB(i), GETPC());     \
494             addr = addr_add(env, addr, 1);                        \
495         }                                                         \
496     }                                                             \
497 }
498 
499 VSX_STXVL(stxvl, 0)
500 VSX_STXVL(stxvll, 1)
501 #undef VSX_STXVL
502 #undef GET_NB
503 #endif /* TARGET_PPC64 */
504 
505 #undef HI_IDX
506 #undef LO_IDX
507 
508 void helper_tbegin(CPUPPCState *env)
509 {
510     /*
511      * As a degenerate implementation, always fail tbegin.  The reason
512      * given is "Nesting overflow".  The "persistent" bit is set,
513      * providing a hint to the error handler to not retry.  The TFIAR
514      * captures the address of the failure, which is this tbegin
515      * instruction.  Instruction execution will continue with the next
516      * instruction in memory, which is precisely what we want.
517      */
518 
519     env->spr[SPR_TEXASR] =
520         (1ULL << TEXASR_FAILURE_PERSISTENT) |
521         (1ULL << TEXASR_NESTING_OVERFLOW) |
522         (FIELD_EX64_HV(env->msr) << TEXASR_PRIVILEGE_HV) |
523         (FIELD_EX64(env->msr, MSR, PR) << TEXASR_PRIVILEGE_PR) |
524         (1ULL << TEXASR_FAILURE_SUMMARY) |
525         (1ULL << TEXASR_TFIAR_EXACT);
526     env->spr[SPR_TFIAR] = env->nip | (FIELD_EX64_HV(env->msr) << 1) |
527                           FIELD_EX64(env->msr, MSR, PR);
528     env->spr[SPR_TFHAR] = env->nip + 4;
529     env->crf[0] = 0xB; /* 0b1010 = transaction failure */
530 }
531