]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * This file is subject to the terms and conditions of the GNU General Public | |
3 | * License. See the file "COPYING" in the main directory of this archive | |
4 | * for more details. | |
5 | * | |
6 | * Copyright (C) 1996, 97, 2000, 2001 by Ralf Baechle | |
7 | * Copyright (C) 2001 MIPS Technologies, Inc. | |
8 | */ | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/sched.h> | |
11 | #include <linux/signal.h> | |
d8d4e3ae | 12 | #include <linux/module.h> |
1da177e4 LT |
13 | #include <asm/branch.h> |
14 | #include <asm/cpu.h> | |
15 | #include <asm/cpu-features.h> | |
1d74f6bc | 16 | #include <asm/fpu.h> |
fb6883e5 | 17 | #include <asm/fpu_emulator.h> |
1da177e4 LT |
18 | #include <asm/inst.h> |
19 | #include <asm/ptrace.h> | |
20 | #include <asm/uaccess.h> | |
21 | ||
fb6883e5 | 22 | /* |
8508488f SH |
23 | * Calculate and return exception PC in case of branch delay slot |
24 | * for microMIPS and MIPS16e. It does not clear the ISA mode bit. | |
fb6883e5 LY |
25 | */ |
26 | int __isa_exception_epc(struct pt_regs *regs) | |
27 | { | |
fb6883e5 | 28 | unsigned short inst; |
8508488f | 29 | long epc = regs->cp0_epc; |
fb6883e5 LY |
30 | |
31 | /* Calculate exception PC in branch delay slot. */ | |
32 | if (__get_user(inst, (u16 __user *) msk_isa16_mode(epc))) { | |
33 | /* This should never happen because delay slot was checked. */ | |
34 | force_sig(SIGSEGV, current); | |
35 | return epc; | |
36 | } | |
8508488f SH |
37 | if (cpu_has_mips16) { |
38 | if (((union mips16e_instruction)inst).ri.opcode | |
39 | == MIPS16e_jal_op) | |
40 | epc += 4; | |
41 | else | |
42 | epc += 2; | |
43 | } else if (mm_insn_16bit(inst)) | |
fb6883e5 LY |
44 | epc += 2; |
45 | else | |
46 | epc += 4; | |
47 | ||
48 | return epc; | |
49 | } | |
50 | ||
76fbfc31 RB |
51 | /* (microMIPS) Convert 16-bit register encoding to 32-bit register encoding. */ |
52 | static const unsigned int reg16to32map[8] = {16, 17, 2, 3, 4, 5, 6, 7}; | |
53 | ||
54 | int __mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, | |
55 | unsigned long *contpc) | |
56 | { | |
57 | union mips_instruction insn = (union mips_instruction)dec_insn.insn; | |
58 | int bc_false = 0; | |
59 | unsigned int fcr31; | |
60 | unsigned int bit; | |
61 | ||
62 | if (!cpu_has_mmips) | |
63 | return 0; | |
64 | ||
65 | switch (insn.mm_i_format.opcode) { | |
66 | case mm_pool32a_op: | |
67 | if ((insn.mm_i_format.simmediate & MM_POOL32A_MINOR_MASK) == | |
68 | mm_pool32axf_op) { | |
69 | switch (insn.mm_i_format.simmediate >> | |
70 | MM_POOL32A_MINOR_SHIFT) { | |
71 | case mm_jalr_op: | |
72 | case mm_jalrhb_op: | |
73 | case mm_jalrs_op: | |
74 | case mm_jalrshb_op: | |
75 | if (insn.mm_i_format.rt != 0) /* Not mm_jr */ | |
76 | regs->regs[insn.mm_i_format.rt] = | |
77 | regs->cp0_epc + | |
78 | dec_insn.pc_inc + | |
79 | dec_insn.next_pc_inc; | |
80 | *contpc = regs->regs[insn.mm_i_format.rs]; | |
81 | return 1; | |
82 | } | |
83 | } | |
84 | break; | |
85 | case mm_pool32i_op: | |
86 | switch (insn.mm_i_format.rt) { | |
87 | case mm_bltzals_op: | |
88 | case mm_bltzal_op: | |
89 | regs->regs[31] = regs->cp0_epc + | |
90 | dec_insn.pc_inc + | |
91 | dec_insn.next_pc_inc; | |
92 | /* Fall through */ | |
93 | case mm_bltz_op: | |
94 | if ((long)regs->regs[insn.mm_i_format.rs] < 0) | |
95 | *contpc = regs->cp0_epc + | |
96 | dec_insn.pc_inc + | |
97 | (insn.mm_i_format.simmediate << 1); | |
98 | else | |
99 | *contpc = regs->cp0_epc + | |
100 | dec_insn.pc_inc + | |
101 | dec_insn.next_pc_inc; | |
102 | return 1; | |
103 | case mm_bgezals_op: | |
104 | case mm_bgezal_op: | |
105 | regs->regs[31] = regs->cp0_epc + | |
106 | dec_insn.pc_inc + | |
107 | dec_insn.next_pc_inc; | |
108 | /* Fall through */ | |
109 | case mm_bgez_op: | |
110 | if ((long)regs->regs[insn.mm_i_format.rs] >= 0) | |
111 | *contpc = regs->cp0_epc + | |
112 | dec_insn.pc_inc + | |
113 | (insn.mm_i_format.simmediate << 1); | |
114 | else | |
115 | *contpc = regs->cp0_epc + | |
116 | dec_insn.pc_inc + | |
117 | dec_insn.next_pc_inc; | |
118 | return 1; | |
119 | case mm_blez_op: | |
120 | if ((long)regs->regs[insn.mm_i_format.rs] <= 0) | |
121 | *contpc = regs->cp0_epc + | |
122 | dec_insn.pc_inc + | |
123 | (insn.mm_i_format.simmediate << 1); | |
124 | else | |
125 | *contpc = regs->cp0_epc + | |
126 | dec_insn.pc_inc + | |
127 | dec_insn.next_pc_inc; | |
128 | return 1; | |
129 | case mm_bgtz_op: | |
130 | if ((long)regs->regs[insn.mm_i_format.rs] <= 0) | |
131 | *contpc = regs->cp0_epc + | |
132 | dec_insn.pc_inc + | |
133 | (insn.mm_i_format.simmediate << 1); | |
134 | else | |
135 | *contpc = regs->cp0_epc + | |
136 | dec_insn.pc_inc + | |
137 | dec_insn.next_pc_inc; | |
138 | return 1; | |
139 | case mm_bc2f_op: | |
140 | case mm_bc1f_op: | |
141 | bc_false = 1; | |
142 | /* Fall through */ | |
143 | case mm_bc2t_op: | |
144 | case mm_bc1t_op: | |
145 | preempt_disable(); | |
146 | if (is_fpu_owner()) | |
842dfc11 | 147 | fcr31 = read_32bit_cp1_register(CP1_STATUS); |
76fbfc31 RB |
148 | else |
149 | fcr31 = current->thread.fpu.fcr31; | |
150 | preempt_enable(); | |
151 | ||
152 | if (bc_false) | |
153 | fcr31 = ~fcr31; | |
154 | ||
155 | bit = (insn.mm_i_format.rs >> 2); | |
156 | bit += (bit != 0); | |
157 | bit += 23; | |
158 | if (fcr31 & (1 << bit)) | |
159 | *contpc = regs->cp0_epc + | |
160 | dec_insn.pc_inc + | |
161 | (insn.mm_i_format.simmediate << 1); | |
162 | else | |
163 | *contpc = regs->cp0_epc + | |
164 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
165 | return 1; | |
166 | } | |
167 | break; | |
168 | case mm_pool16c_op: | |
169 | switch (insn.mm_i_format.rt) { | |
170 | case mm_jalr16_op: | |
171 | case mm_jalrs16_op: | |
172 | regs->regs[31] = regs->cp0_epc + | |
173 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
174 | /* Fall through */ | |
175 | case mm_jr16_op: | |
176 | *contpc = regs->regs[insn.mm_i_format.rs]; | |
177 | return 1; | |
178 | } | |
179 | break; | |
180 | case mm_beqz16_op: | |
181 | if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] == 0) | |
182 | *contpc = regs->cp0_epc + | |
183 | dec_insn.pc_inc + | |
184 | (insn.mm_b1_format.simmediate << 1); | |
185 | else | |
186 | *contpc = regs->cp0_epc + | |
187 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
188 | return 1; | |
189 | case mm_bnez16_op: | |
190 | if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] != 0) | |
191 | *contpc = regs->cp0_epc + | |
192 | dec_insn.pc_inc + | |
193 | (insn.mm_b1_format.simmediate << 1); | |
194 | else | |
195 | *contpc = regs->cp0_epc + | |
196 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
197 | return 1; | |
198 | case mm_b16_op: | |
199 | *contpc = regs->cp0_epc + dec_insn.pc_inc + | |
200 | (insn.mm_b0_format.simmediate << 1); | |
201 | return 1; | |
202 | case mm_beq32_op: | |
203 | if (regs->regs[insn.mm_i_format.rs] == | |
204 | regs->regs[insn.mm_i_format.rt]) | |
205 | *contpc = regs->cp0_epc + | |
206 | dec_insn.pc_inc + | |
207 | (insn.mm_i_format.simmediate << 1); | |
208 | else | |
209 | *contpc = regs->cp0_epc + | |
210 | dec_insn.pc_inc + | |
211 | dec_insn.next_pc_inc; | |
212 | return 1; | |
213 | case mm_bne32_op: | |
214 | if (regs->regs[insn.mm_i_format.rs] != | |
215 | regs->regs[insn.mm_i_format.rt]) | |
216 | *contpc = regs->cp0_epc + | |
217 | dec_insn.pc_inc + | |
218 | (insn.mm_i_format.simmediate << 1); | |
219 | else | |
220 | *contpc = regs->cp0_epc + | |
221 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
222 | return 1; | |
223 | case mm_jalx32_op: | |
224 | regs->regs[31] = regs->cp0_epc + | |
225 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
226 | *contpc = regs->cp0_epc + dec_insn.pc_inc; | |
227 | *contpc >>= 28; | |
228 | *contpc <<= 28; | |
229 | *contpc |= (insn.j_format.target << 2); | |
230 | return 1; | |
231 | case mm_jals32_op: | |
232 | case mm_jal32_op: | |
233 | regs->regs[31] = regs->cp0_epc + | |
234 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
235 | /* Fall through */ | |
236 | case mm_j32_op: | |
237 | *contpc = regs->cp0_epc + dec_insn.pc_inc; | |
238 | *contpc >>= 27; | |
239 | *contpc <<= 27; | |
240 | *contpc |= (insn.j_format.target << 1); | |
241 | set_isa16_mode(*contpc); | |
242 | return 1; | |
243 | } | |
244 | return 0; | |
245 | } | |
246 | ||
fb6883e5 LY |
247 | /* |
248 | * Compute return address and emulate branch in microMIPS mode after an | |
249 | * exception only. It does not handle compact branches/jumps and cannot | |
250 | * be used in interrupt context. (Compact branches/jumps do not cause | |
251 | * exceptions.) | |
252 | */ | |
253 | int __microMIPS_compute_return_epc(struct pt_regs *regs) | |
254 | { | |
255 | u16 __user *pc16; | |
256 | u16 halfword; | |
257 | unsigned int word; | |
258 | unsigned long contpc; | |
259 | struct mm_decoded_insn mminsn = { 0 }; | |
260 | ||
261 | mminsn.micro_mips_mode = 1; | |
262 | ||
263 | /* This load never faults. */ | |
264 | pc16 = (unsigned short __user *)msk_isa16_mode(regs->cp0_epc); | |
265 | __get_user(halfword, pc16); | |
266 | pc16++; | |
267 | contpc = regs->cp0_epc + 2; | |
268 | word = ((unsigned int)halfword << 16); | |
269 | mminsn.pc_inc = 2; | |
270 | ||
271 | if (!mm_insn_16bit(halfword)) { | |
272 | __get_user(halfword, pc16); | |
273 | pc16++; | |
274 | contpc = regs->cp0_epc + 4; | |
275 | mminsn.pc_inc = 4; | |
276 | word |= halfword; | |
277 | } | |
278 | mminsn.insn = word; | |
279 | ||
280 | if (get_user(halfword, pc16)) | |
281 | goto sigsegv; | |
282 | mminsn.next_pc_inc = 2; | |
283 | word = ((unsigned int)halfword << 16); | |
284 | ||
285 | if (!mm_insn_16bit(halfword)) { | |
286 | pc16++; | |
287 | if (get_user(halfword, pc16)) | |
288 | goto sigsegv; | |
289 | mminsn.next_pc_inc = 4; | |
290 | word |= halfword; | |
291 | } | |
292 | mminsn.next_insn = word; | |
293 | ||
294 | mm_isBranchInstr(regs, mminsn, &contpc); | |
295 | ||
296 | regs->cp0_epc = contpc; | |
297 | ||
298 | return 0; | |
299 | ||
300 | sigsegv: | |
301 | force_sig(SIGSEGV, current); | |
302 | return -EFAULT; | |
303 | } | |
304 | ||
8508488f SH |
305 | /* |
306 | * Compute return address and emulate branch in MIPS16e mode after an | |
307 | * exception only. It does not handle compact branches/jumps and cannot | |
308 | * be used in interrupt context. (Compact branches/jumps do not cause | |
309 | * exceptions.) | |
310 | */ | |
311 | int __MIPS16e_compute_return_epc(struct pt_regs *regs) | |
312 | { | |
313 | u16 __user *addr; | |
314 | union mips16e_instruction inst; | |
315 | u16 inst2; | |
316 | u32 fullinst; | |
317 | long epc; | |
318 | ||
319 | epc = regs->cp0_epc; | |
320 | ||
321 | /* Read the instruction. */ | |
322 | addr = (u16 __user *)msk_isa16_mode(epc); | |
323 | if (__get_user(inst.full, addr)) { | |
324 | force_sig(SIGSEGV, current); | |
325 | return -EFAULT; | |
326 | } | |
327 | ||
328 | switch (inst.ri.opcode) { | |
329 | case MIPS16e_extend_op: | |
330 | regs->cp0_epc += 4; | |
331 | return 0; | |
332 | ||
333 | /* | |
334 | * JAL and JALX in MIPS16e mode | |
335 | */ | |
336 | case MIPS16e_jal_op: | |
337 | addr += 1; | |
338 | if (__get_user(inst2, addr)) { | |
339 | force_sig(SIGSEGV, current); | |
340 | return -EFAULT; | |
341 | } | |
342 | fullinst = ((unsigned)inst.full << 16) | inst2; | |
343 | regs->regs[31] = epc + 6; | |
344 | epc += 4; | |
345 | epc >>= 28; | |
346 | epc <<= 28; | |
347 | /* | |
348 | * JAL:5 X:1 TARGET[20-16]:5 TARGET[25:21]:5 TARGET[15:0]:16 | |
349 | * | |
350 | * ......TARGET[15:0].................TARGET[20:16]........... | |
351 | * ......TARGET[25:21] | |
352 | */ | |
353 | epc |= | |
354 | ((fullinst & 0xffff) << 2) | ((fullinst & 0x3e00000) >> 3) | | |
355 | ((fullinst & 0x1f0000) << 7); | |
356 | if (!inst.jal.x) | |
357 | set_isa16_mode(epc); /* Set ISA mode bit. */ | |
358 | regs->cp0_epc = epc; | |
359 | return 0; | |
360 | ||
361 | /* | |
362 | * J(AL)R(C) | |
363 | */ | |
364 | case MIPS16e_rr_op: | |
365 | if (inst.rr.func == MIPS16e_jr_func) { | |
366 | ||
367 | if (inst.rr.ra) | |
368 | regs->cp0_epc = regs->regs[31]; | |
369 | else | |
370 | regs->cp0_epc = | |
371 | regs->regs[reg16to32[inst.rr.rx]]; | |
372 | ||
373 | if (inst.rr.l) { | |
374 | if (inst.rr.nd) | |
375 | regs->regs[31] = epc + 2; | |
376 | else | |
377 | regs->regs[31] = epc + 4; | |
378 | } | |
379 | return 0; | |
380 | } | |
381 | break; | |
382 | } | |
383 | ||
384 | /* | |
385 | * All other cases have no branch delay slot and are 16-bits. | |
386 | * Branches do not cause an exception. | |
387 | */ | |
388 | regs->cp0_epc += 2; | |
389 | ||
390 | return 0; | |
391 | } | |
392 | ||
d8d4e3ae MS |
393 | /** |
394 | * __compute_return_epc_for_insn - Computes the return address and do emulate | |
395 | * branch simulation, if required. | |
396 | * | |
397 | * @regs: Pointer to pt_regs | |
398 | * @insn: branch instruction to decode | |
399 | * @returns: -EFAULT on error and forces SIGBUS, and on success | |
400 | * returns 0 or BRANCH_LIKELY_TAKEN as appropriate after | |
401 | * evaluating the branch. | |
1da177e4 | 402 | */ |
d8d4e3ae MS |
403 | int __compute_return_epc_for_insn(struct pt_regs *regs, |
404 | union mips_instruction insn) | |
1da177e4 | 405 | { |
5e0373b8 | 406 | unsigned int bit, fcr31, dspcontrol; |
d8d4e3ae MS |
407 | long epc = regs->cp0_epc; |
408 | int ret = 0; | |
1da177e4 | 409 | |
1da177e4 LT |
410 | switch (insn.i_format.opcode) { |
411 | /* | |
412 | * jr and jalr are in r_format format. | |
413 | */ | |
414 | case spec_op: | |
415 | switch (insn.r_format.func) { | |
416 | case jalr_op: | |
417 | regs->regs[insn.r_format.rd] = epc + 8; | |
418 | /* Fall through */ | |
419 | case jr_op: | |
5f9f41c4 MC |
420 | if (NO_R6EMU && insn.r_format.func == jr_op) |
421 | goto sigill_r6; | |
1da177e4 LT |
422 | regs->cp0_epc = regs->regs[insn.r_format.rs]; |
423 | break; | |
424 | } | |
425 | break; | |
426 | ||
427 | /* | |
428 | * This group contains: | |
429 | * bltz_op, bgez_op, bltzl_op, bgezl_op, | |
430 | * bltzal_op, bgezal_op, bltzall_op, bgezall_op. | |
431 | */ | |
432 | case bcond_op: | |
433 | switch (insn.i_format.rt) { | |
1da177e4 | 434 | case bltzl_op: |
319824ea MC |
435 | if (NO_R6EMU) |
436 | goto sigill_r6; | |
437 | case bltz_op: | |
d8d4e3ae | 438 | if ((long)regs->regs[insn.i_format.rs] < 0) { |
1da177e4 | 439 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
d8d4e3ae MS |
440 | if (insn.i_format.rt == bltzl_op) |
441 | ret = BRANCH_LIKELY_TAKEN; | |
442 | } else | |
1da177e4 LT |
443 | epc += 8; |
444 | regs->cp0_epc = epc; | |
445 | break; | |
446 | ||
1da177e4 | 447 | case bgezl_op: |
319824ea MC |
448 | if (NO_R6EMU) |
449 | goto sigill_r6; | |
450 | case bgez_op: | |
d8d4e3ae | 451 | if ((long)regs->regs[insn.i_format.rs] >= 0) { |
1da177e4 | 452 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
d8d4e3ae MS |
453 | if (insn.i_format.rt == bgezl_op) |
454 | ret = BRANCH_LIKELY_TAKEN; | |
455 | } else | |
1da177e4 LT |
456 | epc += 8; |
457 | regs->cp0_epc = epc; | |
458 | break; | |
459 | ||
460 | case bltzal_op: | |
461 | case bltzall_op: | |
319824ea MC |
462 | if (NO_R6EMU && (insn.i_format.rs || |
463 | insn.i_format.rt == bltzall_op)) { | |
464 | ret = -SIGILL; | |
465 | break; | |
466 | } | |
1da177e4 | 467 | regs->regs[31] = epc + 8; |
319824ea MC |
468 | /* |
469 | * OK we are here either because we hit a NAL | |
470 | * instruction or because we are emulating an | |
471 | * old bltzal{,l} one. Lets figure out what the | |
472 | * case really is. | |
473 | */ | |
474 | if (!insn.i_format.rs) { | |
475 | /* | |
476 | * NAL or BLTZAL with rs == 0 | |
477 | * Doesn't matter if we are R6 or not. The | |
478 | * result is the same | |
479 | */ | |
480 | regs->cp0_epc += 4 + | |
481 | (insn.i_format.simmediate << 2); | |
482 | break; | |
483 | } | |
484 | /* Now do the real thing for non-R6 BLTZAL{,L} */ | |
d8d4e3ae | 485 | if ((long)regs->regs[insn.i_format.rs] < 0) { |
1da177e4 | 486 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
d8d4e3ae MS |
487 | if (insn.i_format.rt == bltzall_op) |
488 | ret = BRANCH_LIKELY_TAKEN; | |
489 | } else | |
1da177e4 LT |
490 | epc += 8; |
491 | regs->cp0_epc = epc; | |
492 | break; | |
493 | ||
494 | case bgezal_op: | |
495 | case bgezall_op: | |
319824ea MC |
496 | if (NO_R6EMU && (insn.i_format.rs || |
497 | insn.i_format.rt == bgezall_op)) { | |
498 | ret = -SIGILL; | |
499 | break; | |
500 | } | |
1da177e4 | 501 | regs->regs[31] = epc + 8; |
319824ea MC |
502 | /* |
503 | * OK we are here either because we hit a BAL | |
504 | * instruction or because we are emulating an | |
505 | * old bgezal{,l} one. Lets figure out what the | |
506 | * case really is. | |
507 | */ | |
508 | if (!insn.i_format.rs) { | |
509 | /* | |
510 | * BAL or BGEZAL with rs == 0 | |
511 | * Doesn't matter if we are R6 or not. The | |
512 | * result is the same | |
513 | */ | |
514 | regs->cp0_epc += 4 + | |
515 | (insn.i_format.simmediate << 2); | |
516 | break; | |
517 | } | |
518 | /* Now do the real thing for non-R6 BGEZAL{,L} */ | |
d8d4e3ae | 519 | if ((long)regs->regs[insn.i_format.rs] >= 0) { |
1da177e4 | 520 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
d8d4e3ae MS |
521 | if (insn.i_format.rt == bgezall_op) |
522 | ret = BRANCH_LIKELY_TAKEN; | |
523 | } else | |
1da177e4 LT |
524 | epc += 8; |
525 | regs->cp0_epc = epc; | |
526 | break; | |
d8d4e3ae | 527 | |
e50c0a8f RB |
528 | case bposge32_op: |
529 | if (!cpu_has_dsp) | |
5f9f41c4 | 530 | goto sigill_dsp; |
e50c0a8f RB |
531 | |
532 | dspcontrol = rddsp(0x01); | |
533 | ||
534 | if (dspcontrol >= 32) { | |
535 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
536 | } else | |
537 | epc += 8; | |
538 | regs->cp0_epc = epc; | |
539 | break; | |
1da177e4 LT |
540 | } |
541 | break; | |
542 | ||
543 | /* | |
544 | * These are unconditional and in j_format. | |
545 | */ | |
546 | case jal_op: | |
547 | regs->regs[31] = regs->cp0_epc + 8; | |
548 | case j_op: | |
549 | epc += 4; | |
550 | epc >>= 28; | |
551 | epc <<= 28; | |
552 | epc |= (insn.j_format.target << 2); | |
553 | regs->cp0_epc = epc; | |
fb6883e5 LY |
554 | if (insn.i_format.opcode == jalx_op) |
555 | set_isa16_mode(regs->cp0_epc); | |
1da177e4 LT |
556 | break; |
557 | ||
558 | /* | |
559 | * These are conditional and in i_format. | |
560 | */ | |
1da177e4 | 561 | case beql_op: |
319824ea MC |
562 | if (NO_R6EMU) |
563 | goto sigill_r6; | |
564 | case beq_op: | |
1da177e4 | 565 | if (regs->regs[insn.i_format.rs] == |
d8d4e3ae | 566 | regs->regs[insn.i_format.rt]) { |
1da177e4 | 567 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
41ca86e8 | 568 | if (insn.i_format.opcode == beql_op) |
d8d4e3ae MS |
569 | ret = BRANCH_LIKELY_TAKEN; |
570 | } else | |
1da177e4 LT |
571 | epc += 8; |
572 | regs->cp0_epc = epc; | |
573 | break; | |
574 | ||
1da177e4 | 575 | case bnel_op: |
319824ea MC |
576 | if (NO_R6EMU) |
577 | goto sigill_r6; | |
578 | case bne_op: | |
1da177e4 | 579 | if (regs->regs[insn.i_format.rs] != |
d8d4e3ae | 580 | regs->regs[insn.i_format.rt]) { |
1da177e4 | 581 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
41ca86e8 | 582 | if (insn.i_format.opcode == bnel_op) |
d8d4e3ae MS |
583 | ret = BRANCH_LIKELY_TAKEN; |
584 | } else | |
1da177e4 LT |
585 | epc += 8; |
586 | regs->cp0_epc = epc; | |
587 | break; | |
588 | ||
319824ea MC |
589 | case blezl_op: /* not really i_format */ |
590 | if (NO_R6EMU) | |
591 | goto sigill_r6; | |
592 | case blez_op: | |
1da177e4 | 593 | /* rt field assumed to be zero */ |
d8d4e3ae | 594 | if ((long)regs->regs[insn.i_format.rs] <= 0) { |
1da177e4 | 595 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
41ca86e8 | 596 | if (insn.i_format.opcode == blezl_op) |
d8d4e3ae MS |
597 | ret = BRANCH_LIKELY_TAKEN; |
598 | } else | |
1da177e4 LT |
599 | epc += 8; |
600 | regs->cp0_epc = epc; | |
601 | break; | |
602 | ||
1da177e4 | 603 | case bgtzl_op: |
319824ea MC |
604 | if (NO_R6EMU) |
605 | goto sigill_r6; | |
606 | case bgtz_op: | |
1da177e4 | 607 | /* rt field assumed to be zero */ |
d8d4e3ae | 608 | if ((long)regs->regs[insn.i_format.rs] > 0) { |
1da177e4 | 609 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
41ca86e8 | 610 | if (insn.i_format.opcode == bgtzl_op) |
d8d4e3ae MS |
611 | ret = BRANCH_LIKELY_TAKEN; |
612 | } else | |
1da177e4 LT |
613 | epc += 8; |
614 | regs->cp0_epc = epc; | |
615 | break; | |
616 | ||
617 | /* | |
618 | * And now the FPA/cp1 branch instructions. | |
619 | */ | |
620 | case cop1_op: | |
1d74f6bc RB |
621 | preempt_disable(); |
622 | if (is_fpu_owner()) | |
842dfc11 | 623 | fcr31 = read_32bit_cp1_register(CP1_STATUS); |
1d74f6bc | 624 | else |
eae89076 | 625 | fcr31 = current->thread.fpu.fcr31; |
1d74f6bc RB |
626 | preempt_enable(); |
627 | ||
1da177e4 LT |
628 | bit = (insn.i_format.rt >> 2); |
629 | bit += (bit != 0); | |
630 | bit += 23; | |
ee1cca1b | 631 | switch (insn.i_format.rt & 3) { |
70342287 RB |
632 | case 0: /* bc1f */ |
633 | case 2: /* bc1fl */ | |
d8d4e3ae | 634 | if (~fcr31 & (1 << bit)) { |
1da177e4 | 635 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
d8d4e3ae MS |
636 | if (insn.i_format.rt == 2) |
637 | ret = BRANCH_LIKELY_TAKEN; | |
638 | } else | |
1da177e4 LT |
639 | epc += 8; |
640 | regs->cp0_epc = epc; | |
641 | break; | |
642 | ||
70342287 RB |
643 | case 1: /* bc1t */ |
644 | case 3: /* bc1tl */ | |
d8d4e3ae | 645 | if (fcr31 & (1 << bit)) { |
1da177e4 | 646 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
d8d4e3ae MS |
647 | if (insn.i_format.rt == 3) |
648 | ret = BRANCH_LIKELY_TAKEN; | |
649 | } else | |
1da177e4 LT |
650 | epc += 8; |
651 | regs->cp0_epc = epc; | |
652 | break; | |
653 | } | |
654 | break; | |
126336f0 DD |
655 | #ifdef CONFIG_CPU_CAVIUM_OCTEON |
656 | case lwc2_op: /* This is bbit0 on Octeon */ | |
657 | if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) | |
658 | == 0) | |
659 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
660 | else | |
661 | epc += 8; | |
662 | regs->cp0_epc = epc; | |
663 | break; | |
664 | case ldc2_op: /* This is bbit032 on Octeon */ | |
665 | if ((regs->regs[insn.i_format.rs] & | |
666 | (1ull<<(insn.i_format.rt+32))) == 0) | |
667 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
668 | else | |
669 | epc += 8; | |
670 | regs->cp0_epc = epc; | |
671 | break; | |
672 | case swc2_op: /* This is bbit1 on Octeon */ | |
673 | if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) | |
674 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
675 | else | |
676 | epc += 8; | |
677 | regs->cp0_epc = epc; | |
678 | break; | |
679 | case sdc2_op: /* This is bbit132 on Octeon */ | |
680 | if (regs->regs[insn.i_format.rs] & | |
681 | (1ull<<(insn.i_format.rt+32))) | |
682 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
683 | else | |
684 | epc += 8; | |
685 | regs->cp0_epc = epc; | |
686 | break; | |
687 | #endif | |
1da177e4 LT |
688 | } |
689 | ||
d8d4e3ae | 690 | return ret; |
1da177e4 | 691 | |
5f9f41c4 | 692 | sigill_dsp: |
d8d4e3ae | 693 | printk("%s: DSP branch but not DSP ASE - sending SIGBUS.\n", current->comm); |
1da177e4 LT |
694 | force_sig(SIGBUS, current); |
695 | return -EFAULT; | |
5f9f41c4 MC |
696 | sigill_r6: |
697 | pr_info("%s: R2 branch but r2-to-r6 emulator is not preset - sending SIGILL.\n", | |
698 | current->comm); | |
699 | force_sig(SIGILL, current); | |
700 | return -EFAULT; | |
d8d4e3ae MS |
701 | } |
702 | EXPORT_SYMBOL_GPL(__compute_return_epc_for_insn); | |
e50c0a8f | 703 | |
d8d4e3ae MS |
704 | int __compute_return_epc(struct pt_regs *regs) |
705 | { | |
706 | unsigned int __user *addr; | |
707 | long epc; | |
708 | union mips_instruction insn; | |
709 | ||
710 | epc = regs->cp0_epc; | |
711 | if (epc & 3) | |
712 | goto unaligned; | |
713 | ||
714 | /* | |
715 | * Read the instruction | |
716 | */ | |
717 | addr = (unsigned int __user *) epc; | |
718 | if (__get_user(insn.word, addr)) { | |
719 | force_sig(SIGSEGV, current); | |
720 | return -EFAULT; | |
721 | } | |
722 | ||
723 | return __compute_return_epc_for_insn(regs, insn); | |
724 | ||
725 | unaligned: | |
726 | printk("%s: unaligned epc - sending SIGBUS.\n", current->comm); | |
e50c0a8f RB |
727 | force_sig(SIGBUS, current); |
728 | return -EFAULT; | |
1da177e4 | 729 | } |