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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 | 18 | #include <asm/inst.h> |
b0a668fb | 19 | #include <asm/mips-r2-to-r6-emul.h> |
1da177e4 LT |
20 | #include <asm/ptrace.h> |
21 | #include <asm/uaccess.h> | |
22 | ||
fb6883e5 | 23 | /* |
8508488f SH |
24 | * Calculate and return exception PC in case of branch delay slot |
25 | * for microMIPS and MIPS16e. It does not clear the ISA mode bit. | |
fb6883e5 LY |
26 | */ |
27 | int __isa_exception_epc(struct pt_regs *regs) | |
28 | { | |
fb6883e5 | 29 | unsigned short inst; |
8508488f | 30 | long epc = regs->cp0_epc; |
fb6883e5 LY |
31 | |
32 | /* Calculate exception PC in branch delay slot. */ | |
33 | if (__get_user(inst, (u16 __user *) msk_isa16_mode(epc))) { | |
34 | /* This should never happen because delay slot was checked. */ | |
35 | force_sig(SIGSEGV, current); | |
36 | return epc; | |
37 | } | |
8508488f | 38 | if (cpu_has_mips16) { |
e6baf0e0 TT |
39 | union mips16e_instruction inst_mips16e; |
40 | ||
41 | inst_mips16e.full = inst; | |
42 | if (inst_mips16e.ri.opcode == MIPS16e_jal_op) | |
8508488f SH |
43 | epc += 4; |
44 | else | |
45 | epc += 2; | |
46 | } else if (mm_insn_16bit(inst)) | |
fb6883e5 LY |
47 | epc += 2; |
48 | else | |
49 | epc += 4; | |
50 | ||
51 | return epc; | |
52 | } | |
53 | ||
76fbfc31 RB |
54 | /* (microMIPS) Convert 16-bit register encoding to 32-bit register encoding. */ |
55 | static const unsigned int reg16to32map[8] = {16, 17, 2, 3, 4, 5, 6, 7}; | |
56 | ||
57 | int __mm_isBranchInstr(struct pt_regs *regs, struct mm_decoded_insn dec_insn, | |
58 | unsigned long *contpc) | |
59 | { | |
60 | union mips_instruction insn = (union mips_instruction)dec_insn.insn; | |
61 | int bc_false = 0; | |
62 | unsigned int fcr31; | |
63 | unsigned int bit; | |
64 | ||
65 | if (!cpu_has_mmips) | |
66 | return 0; | |
67 | ||
68 | switch (insn.mm_i_format.opcode) { | |
69 | case mm_pool32a_op: | |
70 | if ((insn.mm_i_format.simmediate & MM_POOL32A_MINOR_MASK) == | |
71 | mm_pool32axf_op) { | |
72 | switch (insn.mm_i_format.simmediate >> | |
73 | MM_POOL32A_MINOR_SHIFT) { | |
74 | case mm_jalr_op: | |
75 | case mm_jalrhb_op: | |
76 | case mm_jalrs_op: | |
77 | case mm_jalrshb_op: | |
78 | if (insn.mm_i_format.rt != 0) /* Not mm_jr */ | |
79 | regs->regs[insn.mm_i_format.rt] = | |
80 | regs->cp0_epc + | |
81 | dec_insn.pc_inc + | |
82 | dec_insn.next_pc_inc; | |
83 | *contpc = regs->regs[insn.mm_i_format.rs]; | |
84 | return 1; | |
85 | } | |
86 | } | |
87 | break; | |
88 | case mm_pool32i_op: | |
89 | switch (insn.mm_i_format.rt) { | |
90 | case mm_bltzals_op: | |
91 | case mm_bltzal_op: | |
92 | regs->regs[31] = regs->cp0_epc + | |
93 | dec_insn.pc_inc + | |
94 | dec_insn.next_pc_inc; | |
95 | /* Fall through */ | |
96 | case mm_bltz_op: | |
97 | if ((long)regs->regs[insn.mm_i_format.rs] < 0) | |
98 | *contpc = regs->cp0_epc + | |
99 | dec_insn.pc_inc + | |
100 | (insn.mm_i_format.simmediate << 1); | |
101 | else | |
102 | *contpc = regs->cp0_epc + | |
103 | dec_insn.pc_inc + | |
104 | dec_insn.next_pc_inc; | |
105 | return 1; | |
106 | case mm_bgezals_op: | |
107 | case mm_bgezal_op: | |
108 | regs->regs[31] = regs->cp0_epc + | |
109 | dec_insn.pc_inc + | |
110 | dec_insn.next_pc_inc; | |
111 | /* Fall through */ | |
112 | case mm_bgez_op: | |
113 | if ((long)regs->regs[insn.mm_i_format.rs] >= 0) | |
114 | *contpc = regs->cp0_epc + | |
115 | dec_insn.pc_inc + | |
116 | (insn.mm_i_format.simmediate << 1); | |
117 | else | |
118 | *contpc = regs->cp0_epc + | |
119 | dec_insn.pc_inc + | |
120 | dec_insn.next_pc_inc; | |
121 | return 1; | |
122 | case mm_blez_op: | |
123 | if ((long)regs->regs[insn.mm_i_format.rs] <= 0) | |
124 | *contpc = regs->cp0_epc + | |
125 | dec_insn.pc_inc + | |
126 | (insn.mm_i_format.simmediate << 1); | |
127 | else | |
128 | *contpc = regs->cp0_epc + | |
129 | dec_insn.pc_inc + | |
130 | dec_insn.next_pc_inc; | |
131 | return 1; | |
132 | case mm_bgtz_op: | |
133 | if ((long)regs->regs[insn.mm_i_format.rs] <= 0) | |
134 | *contpc = regs->cp0_epc + | |
135 | dec_insn.pc_inc + | |
136 | (insn.mm_i_format.simmediate << 1); | |
137 | else | |
138 | *contpc = regs->cp0_epc + | |
139 | dec_insn.pc_inc + | |
140 | dec_insn.next_pc_inc; | |
141 | return 1; | |
142 | case mm_bc2f_op: | |
143 | case mm_bc1f_op: | |
144 | bc_false = 1; | |
145 | /* Fall through */ | |
146 | case mm_bc2t_op: | |
147 | case mm_bc1t_op: | |
148 | preempt_disable(); | |
149 | if (is_fpu_owner()) | |
842dfc11 | 150 | fcr31 = read_32bit_cp1_register(CP1_STATUS); |
76fbfc31 RB |
151 | else |
152 | fcr31 = current->thread.fpu.fcr31; | |
153 | preempt_enable(); | |
154 | ||
155 | if (bc_false) | |
156 | fcr31 = ~fcr31; | |
157 | ||
158 | bit = (insn.mm_i_format.rs >> 2); | |
159 | bit += (bit != 0); | |
160 | bit += 23; | |
161 | if (fcr31 & (1 << bit)) | |
162 | *contpc = regs->cp0_epc + | |
163 | dec_insn.pc_inc + | |
164 | (insn.mm_i_format.simmediate << 1); | |
165 | else | |
166 | *contpc = regs->cp0_epc + | |
167 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
168 | return 1; | |
169 | } | |
170 | break; | |
171 | case mm_pool16c_op: | |
172 | switch (insn.mm_i_format.rt) { | |
173 | case mm_jalr16_op: | |
174 | case mm_jalrs16_op: | |
175 | regs->regs[31] = regs->cp0_epc + | |
176 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
177 | /* Fall through */ | |
178 | case mm_jr16_op: | |
179 | *contpc = regs->regs[insn.mm_i_format.rs]; | |
180 | return 1; | |
181 | } | |
182 | break; | |
183 | case mm_beqz16_op: | |
184 | if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] == 0) | |
185 | *contpc = regs->cp0_epc + | |
186 | dec_insn.pc_inc + | |
187 | (insn.mm_b1_format.simmediate << 1); | |
188 | else | |
189 | *contpc = regs->cp0_epc + | |
190 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
191 | return 1; | |
192 | case mm_bnez16_op: | |
193 | if ((long)regs->regs[reg16to32map[insn.mm_b1_format.rs]] != 0) | |
194 | *contpc = regs->cp0_epc + | |
195 | dec_insn.pc_inc + | |
196 | (insn.mm_b1_format.simmediate << 1); | |
197 | else | |
198 | *contpc = regs->cp0_epc + | |
199 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
200 | return 1; | |
201 | case mm_b16_op: | |
202 | *contpc = regs->cp0_epc + dec_insn.pc_inc + | |
203 | (insn.mm_b0_format.simmediate << 1); | |
204 | return 1; | |
205 | case mm_beq32_op: | |
206 | if (regs->regs[insn.mm_i_format.rs] == | |
207 | regs->regs[insn.mm_i_format.rt]) | |
208 | *contpc = regs->cp0_epc + | |
209 | dec_insn.pc_inc + | |
210 | (insn.mm_i_format.simmediate << 1); | |
211 | else | |
212 | *contpc = regs->cp0_epc + | |
213 | dec_insn.pc_inc + | |
214 | dec_insn.next_pc_inc; | |
215 | return 1; | |
216 | case mm_bne32_op: | |
217 | if (regs->regs[insn.mm_i_format.rs] != | |
218 | regs->regs[insn.mm_i_format.rt]) | |
219 | *contpc = regs->cp0_epc + | |
220 | dec_insn.pc_inc + | |
221 | (insn.mm_i_format.simmediate << 1); | |
222 | else | |
223 | *contpc = regs->cp0_epc + | |
224 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
225 | return 1; | |
226 | case mm_jalx32_op: | |
227 | regs->regs[31] = regs->cp0_epc + | |
228 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
229 | *contpc = regs->cp0_epc + dec_insn.pc_inc; | |
230 | *contpc >>= 28; | |
231 | *contpc <<= 28; | |
232 | *contpc |= (insn.j_format.target << 2); | |
233 | return 1; | |
234 | case mm_jals32_op: | |
235 | case mm_jal32_op: | |
236 | regs->regs[31] = regs->cp0_epc + | |
237 | dec_insn.pc_inc + dec_insn.next_pc_inc; | |
238 | /* Fall through */ | |
239 | case mm_j32_op: | |
240 | *contpc = regs->cp0_epc + dec_insn.pc_inc; | |
241 | *contpc >>= 27; | |
242 | *contpc <<= 27; | |
243 | *contpc |= (insn.j_format.target << 1); | |
244 | set_isa16_mode(*contpc); | |
245 | return 1; | |
246 | } | |
247 | return 0; | |
248 | } | |
249 | ||
fb6883e5 LY |
250 | /* |
251 | * Compute return address and emulate branch in microMIPS mode after an | |
252 | * exception only. It does not handle compact branches/jumps and cannot | |
253 | * be used in interrupt context. (Compact branches/jumps do not cause | |
254 | * exceptions.) | |
255 | */ | |
256 | int __microMIPS_compute_return_epc(struct pt_regs *regs) | |
257 | { | |
258 | u16 __user *pc16; | |
259 | u16 halfword; | |
260 | unsigned int word; | |
261 | unsigned long contpc; | |
262 | struct mm_decoded_insn mminsn = { 0 }; | |
263 | ||
264 | mminsn.micro_mips_mode = 1; | |
265 | ||
266 | /* This load never faults. */ | |
267 | pc16 = (unsigned short __user *)msk_isa16_mode(regs->cp0_epc); | |
268 | __get_user(halfword, pc16); | |
269 | pc16++; | |
270 | contpc = regs->cp0_epc + 2; | |
271 | word = ((unsigned int)halfword << 16); | |
272 | mminsn.pc_inc = 2; | |
273 | ||
274 | if (!mm_insn_16bit(halfword)) { | |
275 | __get_user(halfword, pc16); | |
276 | pc16++; | |
277 | contpc = regs->cp0_epc + 4; | |
278 | mminsn.pc_inc = 4; | |
279 | word |= halfword; | |
280 | } | |
281 | mminsn.insn = word; | |
282 | ||
283 | if (get_user(halfword, pc16)) | |
284 | goto sigsegv; | |
285 | mminsn.next_pc_inc = 2; | |
286 | word = ((unsigned int)halfword << 16); | |
287 | ||
288 | if (!mm_insn_16bit(halfword)) { | |
289 | pc16++; | |
290 | if (get_user(halfword, pc16)) | |
291 | goto sigsegv; | |
292 | mminsn.next_pc_inc = 4; | |
293 | word |= halfword; | |
294 | } | |
295 | mminsn.next_insn = word; | |
296 | ||
297 | mm_isBranchInstr(regs, mminsn, &contpc); | |
298 | ||
299 | regs->cp0_epc = contpc; | |
300 | ||
301 | return 0; | |
302 | ||
303 | sigsegv: | |
304 | force_sig(SIGSEGV, current); | |
305 | return -EFAULT; | |
306 | } | |
307 | ||
8508488f SH |
308 | /* |
309 | * Compute return address and emulate branch in MIPS16e mode after an | |
310 | * exception only. It does not handle compact branches/jumps and cannot | |
311 | * be used in interrupt context. (Compact branches/jumps do not cause | |
312 | * exceptions.) | |
313 | */ | |
314 | int __MIPS16e_compute_return_epc(struct pt_regs *regs) | |
315 | { | |
316 | u16 __user *addr; | |
317 | union mips16e_instruction inst; | |
318 | u16 inst2; | |
319 | u32 fullinst; | |
320 | long epc; | |
321 | ||
322 | epc = regs->cp0_epc; | |
323 | ||
324 | /* Read the instruction. */ | |
325 | addr = (u16 __user *)msk_isa16_mode(epc); | |
326 | if (__get_user(inst.full, addr)) { | |
327 | force_sig(SIGSEGV, current); | |
328 | return -EFAULT; | |
329 | } | |
330 | ||
331 | switch (inst.ri.opcode) { | |
332 | case MIPS16e_extend_op: | |
333 | regs->cp0_epc += 4; | |
334 | return 0; | |
335 | ||
336 | /* | |
337 | * JAL and JALX in MIPS16e mode | |
338 | */ | |
339 | case MIPS16e_jal_op: | |
340 | addr += 1; | |
341 | if (__get_user(inst2, addr)) { | |
342 | force_sig(SIGSEGV, current); | |
343 | return -EFAULT; | |
344 | } | |
345 | fullinst = ((unsigned)inst.full << 16) | inst2; | |
346 | regs->regs[31] = epc + 6; | |
347 | epc += 4; | |
348 | epc >>= 28; | |
349 | epc <<= 28; | |
350 | /* | |
351 | * JAL:5 X:1 TARGET[20-16]:5 TARGET[25:21]:5 TARGET[15:0]:16 | |
352 | * | |
353 | * ......TARGET[15:0].................TARGET[20:16]........... | |
354 | * ......TARGET[25:21] | |
355 | */ | |
356 | epc |= | |
357 | ((fullinst & 0xffff) << 2) | ((fullinst & 0x3e00000) >> 3) | | |
358 | ((fullinst & 0x1f0000) << 7); | |
359 | if (!inst.jal.x) | |
360 | set_isa16_mode(epc); /* Set ISA mode bit. */ | |
361 | regs->cp0_epc = epc; | |
362 | return 0; | |
363 | ||
364 | /* | |
365 | * J(AL)R(C) | |
366 | */ | |
367 | case MIPS16e_rr_op: | |
368 | if (inst.rr.func == MIPS16e_jr_func) { | |
369 | ||
370 | if (inst.rr.ra) | |
371 | regs->cp0_epc = regs->regs[31]; | |
372 | else | |
373 | regs->cp0_epc = | |
374 | regs->regs[reg16to32[inst.rr.rx]]; | |
375 | ||
376 | if (inst.rr.l) { | |
377 | if (inst.rr.nd) | |
378 | regs->regs[31] = epc + 2; | |
379 | else | |
380 | regs->regs[31] = epc + 4; | |
381 | } | |
382 | return 0; | |
383 | } | |
384 | break; | |
385 | } | |
386 | ||
387 | /* | |
388 | * All other cases have no branch delay slot and are 16-bits. | |
389 | * Branches do not cause an exception. | |
390 | */ | |
391 | regs->cp0_epc += 2; | |
392 | ||
393 | return 0; | |
394 | } | |
395 | ||
d8d4e3ae MS |
396 | /** |
397 | * __compute_return_epc_for_insn - Computes the return address and do emulate | |
398 | * branch simulation, if required. | |
399 | * | |
400 | * @regs: Pointer to pt_regs | |
401 | * @insn: branch instruction to decode | |
402 | * @returns: -EFAULT on error and forces SIGBUS, and on success | |
403 | * returns 0 or BRANCH_LIKELY_TAKEN as appropriate after | |
404 | * evaluating the branch. | |
a8ff66f5 MC |
405 | * |
406 | * MIPS R6 Compact branches and forbidden slots: | |
407 | * Compact branches do not throw exceptions because they do | |
408 | * not have delay slots. The forbidden slot instruction ($PC+4) | |
409 | * is only executed if the branch was not taken. Otherwise the | |
410 | * forbidden slot is skipped entirely. This means that the | |
411 | * only possible reason to be here because of a MIPS R6 compact | |
412 | * branch instruction is that the forbidden slot has thrown one. | |
413 | * In that case the branch was not taken, so the EPC can be safely | |
414 | * set to EPC + 8. | |
1da177e4 | 415 | */ |
d8d4e3ae MS |
416 | int __compute_return_epc_for_insn(struct pt_regs *regs, |
417 | union mips_instruction insn) | |
1da177e4 | 418 | { |
c8a34581 | 419 | unsigned int bit, fcr31, dspcontrol, reg; |
d8d4e3ae MS |
420 | long epc = regs->cp0_epc; |
421 | int ret = 0; | |
1da177e4 | 422 | |
1da177e4 LT |
423 | switch (insn.i_format.opcode) { |
424 | /* | |
425 | * jr and jalr are in r_format format. | |
426 | */ | |
427 | case spec_op: | |
428 | switch (insn.r_format.func) { | |
429 | case jalr_op: | |
430 | regs->regs[insn.r_format.rd] = epc + 8; | |
431 | /* Fall through */ | |
432 | case jr_op: | |
5f9f41c4 MC |
433 | if (NO_R6EMU && insn.r_format.func == jr_op) |
434 | goto sigill_r6; | |
1da177e4 LT |
435 | regs->cp0_epc = regs->regs[insn.r_format.rs]; |
436 | break; | |
437 | } | |
438 | break; | |
439 | ||
440 | /* | |
441 | * This group contains: | |
442 | * bltz_op, bgez_op, bltzl_op, bgezl_op, | |
443 | * bltzal_op, bgezal_op, bltzall_op, bgezall_op. | |
444 | */ | |
445 | case bcond_op: | |
446 | switch (insn.i_format.rt) { | |
1da177e4 | 447 | case bltzl_op: |
319824ea MC |
448 | if (NO_R6EMU) |
449 | goto sigill_r6; | |
450 | case bltz_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 == bltzl_op) |
454 | ret = BRANCH_LIKELY_TAKEN; | |
455 | } else | |
1da177e4 LT |
456 | epc += 8; |
457 | regs->cp0_epc = epc; | |
458 | break; | |
459 | ||
1da177e4 | 460 | case bgezl_op: |
319824ea MC |
461 | if (NO_R6EMU) |
462 | goto sigill_r6; | |
463 | case bgez_op: | |
d8d4e3ae | 464 | if ((long)regs->regs[insn.i_format.rs] >= 0) { |
1da177e4 | 465 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
d8d4e3ae MS |
466 | if (insn.i_format.rt == bgezl_op) |
467 | ret = BRANCH_LIKELY_TAKEN; | |
468 | } else | |
1da177e4 LT |
469 | epc += 8; |
470 | regs->cp0_epc = epc; | |
471 | break; | |
472 | ||
473 | case bltzal_op: | |
474 | case bltzall_op: | |
319824ea MC |
475 | if (NO_R6EMU && (insn.i_format.rs || |
476 | insn.i_format.rt == bltzall_op)) { | |
477 | ret = -SIGILL; | |
478 | break; | |
479 | } | |
1da177e4 | 480 | regs->regs[31] = epc + 8; |
319824ea MC |
481 | /* |
482 | * OK we are here either because we hit a NAL | |
483 | * instruction or because we are emulating an | |
4939788e | 484 | * old bltzal{,l} one. Let's figure out what the |
319824ea MC |
485 | * case really is. |
486 | */ | |
487 | if (!insn.i_format.rs) { | |
488 | /* | |
489 | * NAL or BLTZAL with rs == 0 | |
490 | * Doesn't matter if we are R6 or not. The | |
491 | * result is the same | |
492 | */ | |
493 | regs->cp0_epc += 4 + | |
494 | (insn.i_format.simmediate << 2); | |
495 | break; | |
496 | } | |
497 | /* Now do the real thing for non-R6 BLTZAL{,L} */ | |
d8d4e3ae | 498 | if ((long)regs->regs[insn.i_format.rs] < 0) { |
1da177e4 | 499 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
d8d4e3ae MS |
500 | if (insn.i_format.rt == bltzall_op) |
501 | ret = BRANCH_LIKELY_TAKEN; | |
502 | } else | |
1da177e4 LT |
503 | epc += 8; |
504 | regs->cp0_epc = epc; | |
505 | break; | |
506 | ||
507 | case bgezal_op: | |
508 | case bgezall_op: | |
319824ea MC |
509 | if (NO_R6EMU && (insn.i_format.rs || |
510 | insn.i_format.rt == bgezall_op)) { | |
511 | ret = -SIGILL; | |
512 | break; | |
513 | } | |
1da177e4 | 514 | regs->regs[31] = epc + 8; |
319824ea MC |
515 | /* |
516 | * OK we are here either because we hit a BAL | |
517 | * instruction or because we are emulating an | |
4939788e | 518 | * old bgezal{,l} one. Let's figure out what the |
319824ea MC |
519 | * case really is. |
520 | */ | |
521 | if (!insn.i_format.rs) { | |
522 | /* | |
523 | * BAL or BGEZAL with rs == 0 | |
524 | * Doesn't matter if we are R6 or not. The | |
525 | * result is the same | |
526 | */ | |
527 | regs->cp0_epc += 4 + | |
528 | (insn.i_format.simmediate << 2); | |
529 | break; | |
530 | } | |
531 | /* Now do the real thing for non-R6 BGEZAL{,L} */ | |
d8d4e3ae | 532 | if ((long)regs->regs[insn.i_format.rs] >= 0) { |
1da177e4 | 533 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
d8d4e3ae MS |
534 | if (insn.i_format.rt == bgezall_op) |
535 | ret = BRANCH_LIKELY_TAKEN; | |
536 | } else | |
1da177e4 LT |
537 | epc += 8; |
538 | regs->cp0_epc = epc; | |
539 | break; | |
d8d4e3ae | 540 | |
e50c0a8f RB |
541 | case bposge32_op: |
542 | if (!cpu_has_dsp) | |
5f9f41c4 | 543 | goto sigill_dsp; |
e50c0a8f RB |
544 | |
545 | dspcontrol = rddsp(0x01); | |
546 | ||
547 | if (dspcontrol >= 32) { | |
548 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
549 | } else | |
550 | epc += 8; | |
551 | regs->cp0_epc = epc; | |
552 | break; | |
1da177e4 LT |
553 | } |
554 | break; | |
555 | ||
556 | /* | |
557 | * These are unconditional and in j_format. | |
558 | */ | |
559 | case jal_op: | |
560 | regs->regs[31] = regs->cp0_epc + 8; | |
561 | case j_op: | |
562 | epc += 4; | |
563 | epc >>= 28; | |
564 | epc <<= 28; | |
565 | epc |= (insn.j_format.target << 2); | |
566 | regs->cp0_epc = epc; | |
fb6883e5 LY |
567 | if (insn.i_format.opcode == jalx_op) |
568 | set_isa16_mode(regs->cp0_epc); | |
1da177e4 LT |
569 | break; |
570 | ||
571 | /* | |
572 | * These are conditional and in i_format. | |
573 | */ | |
1da177e4 | 574 | case beql_op: |
319824ea MC |
575 | if (NO_R6EMU) |
576 | goto sigill_r6; | |
577 | case beq_op: | |
1da177e4 | 578 | if (regs->regs[insn.i_format.rs] == |
d8d4e3ae | 579 | regs->regs[insn.i_format.rt]) { |
1da177e4 | 580 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
41ca86e8 | 581 | if (insn.i_format.opcode == beql_op) |
d8d4e3ae MS |
582 | ret = BRANCH_LIKELY_TAKEN; |
583 | } else | |
1da177e4 LT |
584 | epc += 8; |
585 | regs->cp0_epc = epc; | |
586 | break; | |
587 | ||
1da177e4 | 588 | case bnel_op: |
319824ea MC |
589 | if (NO_R6EMU) |
590 | goto sigill_r6; | |
591 | case bne_op: | |
1da177e4 | 592 | if (regs->regs[insn.i_format.rs] != |
d8d4e3ae | 593 | regs->regs[insn.i_format.rt]) { |
1da177e4 | 594 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
41ca86e8 | 595 | if (insn.i_format.opcode == bnel_op) |
d8d4e3ae MS |
596 | ret = BRANCH_LIKELY_TAKEN; |
597 | } else | |
1da177e4 LT |
598 | epc += 8; |
599 | regs->cp0_epc = epc; | |
600 | break; | |
601 | ||
319824ea | 602 | case blezl_op: /* not really i_format */ |
e9d92d22 | 603 | if (!insn.i_format.rt && NO_R6EMU) |
319824ea MC |
604 | goto sigill_r6; |
605 | case blez_op: | |
a8ff66f5 MC |
606 | /* |
607 | * Compact branches for R6 for the | |
608 | * blez and blezl opcodes. | |
609 | * BLEZ | rs = 0 | rt != 0 == BLEZALC | |
610 | * BLEZ | rs = rt != 0 == BGEZALC | |
611 | * BLEZ | rs != 0 | rt != 0 == BGEUC | |
612 | * BLEZL | rs = 0 | rt != 0 == BLEZC | |
613 | * BLEZL | rs = rt != 0 == BGEZC | |
614 | * BLEZL | rs != 0 | rt != 0 == BGEC | |
615 | * | |
616 | * For real BLEZ{,L}, rt is always 0. | |
617 | */ | |
618 | ||
619 | if (cpu_has_mips_r6 && insn.i_format.rt) { | |
620 | if ((insn.i_format.opcode == blez_op) && | |
621 | ((!insn.i_format.rs && insn.i_format.rt) || | |
622 | (insn.i_format.rs == insn.i_format.rt))) | |
623 | regs->regs[31] = epc + 4; | |
624 | regs->cp0_epc += 8; | |
625 | break; | |
626 | } | |
1da177e4 | 627 | /* rt field assumed to be zero */ |
d8d4e3ae | 628 | if ((long)regs->regs[insn.i_format.rs] <= 0) { |
1da177e4 | 629 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
41ca86e8 | 630 | if (insn.i_format.opcode == blezl_op) |
d8d4e3ae MS |
631 | ret = BRANCH_LIKELY_TAKEN; |
632 | } else | |
1da177e4 LT |
633 | epc += 8; |
634 | regs->cp0_epc = epc; | |
635 | break; | |
636 | ||
1da177e4 | 637 | case bgtzl_op: |
e9d92d22 | 638 | if (!insn.i_format.rt && NO_R6EMU) |
319824ea MC |
639 | goto sigill_r6; |
640 | case bgtz_op: | |
f1b44067 MC |
641 | /* |
642 | * Compact branches for R6 for the | |
643 | * bgtz and bgtzl opcodes. | |
644 | * BGTZ | rs = 0 | rt != 0 == BGTZALC | |
645 | * BGTZ | rs = rt != 0 == BLTZALC | |
646 | * BGTZ | rs != 0 | rt != 0 == BLTUC | |
647 | * BGTZL | rs = 0 | rt != 0 == BGTZC | |
648 | * BGTZL | rs = rt != 0 == BLTZC | |
649 | * BGTZL | rs != 0 | rt != 0 == BLTC | |
650 | * | |
651 | * *ZALC varint for BGTZ &&& rt != 0 | |
652 | * For real GTZ{,L}, rt is always 0. | |
653 | */ | |
654 | if (cpu_has_mips_r6 && insn.i_format.rt) { | |
655 | if ((insn.i_format.opcode == blez_op) && | |
656 | ((!insn.i_format.rs && insn.i_format.rt) || | |
657 | (insn.i_format.rs == insn.i_format.rt))) | |
658 | regs->regs[31] = epc + 4; | |
659 | regs->cp0_epc += 8; | |
660 | break; | |
661 | } | |
662 | ||
1da177e4 | 663 | /* rt field assumed to be zero */ |
d8d4e3ae | 664 | if ((long)regs->regs[insn.i_format.rs] > 0) { |
1da177e4 | 665 | epc = epc + 4 + (insn.i_format.simmediate << 2); |
41ca86e8 | 666 | if (insn.i_format.opcode == bgtzl_op) |
d8d4e3ae MS |
667 | ret = BRANCH_LIKELY_TAKEN; |
668 | } else | |
1da177e4 LT |
669 | epc += 8; |
670 | regs->cp0_epc = epc; | |
671 | break; | |
672 | ||
673 | /* | |
674 | * And now the FPA/cp1 branch instructions. | |
675 | */ | |
676 | case cop1_op: | |
c8a34581 MC |
677 | if (cpu_has_mips_r6 && |
678 | ((insn.i_format.rs == bc1eqz_op) || | |
679 | (insn.i_format.rs == bc1nez_op))) { | |
680 | if (!used_math()) { /* First time FPU user */ | |
681 | ret = init_fpu(); | |
682 | if (ret && NO_R6EMU) { | |
683 | ret = -ret; | |
684 | break; | |
685 | } | |
686 | ret = 0; | |
687 | set_used_math(); | |
688 | } | |
689 | lose_fpu(1); /* Save FPU state for the emulator. */ | |
690 | reg = insn.i_format.rt; | |
ac149698 PB |
691 | bit = get_fpr32(¤t->thread.fpu.fpr[reg], 0) & 0x1; |
692 | if (insn.i_format.rs == bc1eqz_op) | |
693 | bit = !bit; | |
c8a34581 MC |
694 | own_fpu(1); |
695 | if (bit) | |
696 | epc = epc + 4 + | |
697 | (insn.i_format.simmediate << 2); | |
698 | else | |
1da177e4 LT |
699 | epc += 8; |
700 | regs->cp0_epc = epc; | |
c8a34581 | 701 | |
1da177e4 | 702 | break; |
c8a34581 | 703 | } else { |
1da177e4 | 704 | |
c8a34581 MC |
705 | preempt_disable(); |
706 | if (is_fpu_owner()) | |
707 | fcr31 = read_32bit_cp1_register(CP1_STATUS); | |
708 | else | |
709 | fcr31 = current->thread.fpu.fcr31; | |
710 | preempt_enable(); | |
711 | ||
712 | bit = (insn.i_format.rt >> 2); | |
713 | bit += (bit != 0); | |
714 | bit += 23; | |
715 | switch (insn.i_format.rt & 3) { | |
716 | case 0: /* bc1f */ | |
717 | case 2: /* bc1fl */ | |
718 | if (~fcr31 & (1 << bit)) { | |
719 | epc = epc + 4 + | |
720 | (insn.i_format.simmediate << 2); | |
721 | if (insn.i_format.rt == 2) | |
722 | ret = BRANCH_LIKELY_TAKEN; | |
723 | } else | |
724 | epc += 8; | |
725 | regs->cp0_epc = epc; | |
726 | break; | |
727 | ||
728 | case 1: /* bc1t */ | |
729 | case 3: /* bc1tl */ | |
730 | if (fcr31 & (1 << bit)) { | |
731 | epc = epc + 4 + | |
732 | (insn.i_format.simmediate << 2); | |
733 | if (insn.i_format.rt == 3) | |
734 | ret = BRANCH_LIKELY_TAKEN; | |
735 | } else | |
736 | epc += 8; | |
737 | regs->cp0_epc = epc; | |
738 | break; | |
739 | } | |
1da177e4 LT |
740 | break; |
741 | } | |
126336f0 DD |
742 | #ifdef CONFIG_CPU_CAVIUM_OCTEON |
743 | case lwc2_op: /* This is bbit0 on Octeon */ | |
744 | if ((regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) | |
745 | == 0) | |
746 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
747 | else | |
748 | epc += 8; | |
749 | regs->cp0_epc = epc; | |
750 | break; | |
751 | case ldc2_op: /* This is bbit032 on Octeon */ | |
752 | if ((regs->regs[insn.i_format.rs] & | |
753 | (1ull<<(insn.i_format.rt+32))) == 0) | |
754 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
755 | else | |
756 | epc += 8; | |
757 | regs->cp0_epc = epc; | |
758 | break; | |
759 | case swc2_op: /* This is bbit1 on Octeon */ | |
760 | if (regs->regs[insn.i_format.rs] & (1ull<<insn.i_format.rt)) | |
761 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
762 | else | |
763 | epc += 8; | |
764 | regs->cp0_epc = epc; | |
765 | break; | |
766 | case sdc2_op: /* This is bbit132 on Octeon */ | |
767 | if (regs->regs[insn.i_format.rs] & | |
768 | (1ull<<(insn.i_format.rt+32))) | |
769 | epc = epc + 4 + (insn.i_format.simmediate << 2); | |
770 | else | |
771 | epc += 8; | |
772 | regs->cp0_epc = epc; | |
773 | break; | |
8467ca01 MC |
774 | #else |
775 | case bc6_op: | |
776 | /* Only valid for MIPS R6 */ | |
777 | if (!cpu_has_mips_r6) { | |
778 | ret = -SIGILL; | |
779 | break; | |
780 | } | |
781 | regs->cp0_epc += 8; | |
782 | break; | |
84fef630 MC |
783 | case balc6_op: |
784 | if (!cpu_has_mips_r6) { | |
785 | ret = -SIGILL; | |
786 | break; | |
787 | } | |
788 | /* Compact branch: BALC */ | |
789 | regs->regs[31] = epc + 4; | |
790 | epc += 4 + (insn.i_format.simmediate << 2); | |
791 | regs->cp0_epc = epc; | |
792 | break; | |
1c66b79b | 793 | case pop66_op: |
69b9a2fd MC |
794 | if (!cpu_has_mips_r6) { |
795 | ret = -SIGILL; | |
796 | break; | |
797 | } | |
798 | /* Compact branch: BEQZC || JIC */ | |
799 | regs->cp0_epc += 8; | |
800 | break; | |
1c66b79b | 801 | case pop76_op: |
28d6f93d MC |
802 | if (!cpu_has_mips_r6) { |
803 | ret = -SIGILL; | |
804 | break; | |
805 | } | |
806 | /* Compact branch: BNEZC || JIALC */ | |
807 | if (insn.i_format.rs) | |
808 | regs->regs[31] = epc + 4; | |
809 | regs->cp0_epc += 8; | |
810 | break; | |
126336f0 | 811 | #endif |
1b492600 PB |
812 | case pop10_op: |
813 | case pop30_op: | |
c893ce38 MC |
814 | /* Only valid for MIPS R6 */ |
815 | if (!cpu_has_mips_r6) { | |
816 | ret = -SIGILL; | |
817 | break; | |
818 | } | |
10d962d5 MC |
819 | /* |
820 | * Compact branches: | |
821 | * bovc, beqc, beqzalc, bnvc, bnec, bnezlac | |
822 | */ | |
c893ce38 MC |
823 | if (insn.i_format.rt && !insn.i_format.rs) |
824 | regs->regs[31] = epc + 4; | |
825 | regs->cp0_epc += 8; | |
826 | break; | |
1da177e4 LT |
827 | } |
828 | ||
d8d4e3ae | 829 | return ret; |
1da177e4 | 830 | |
5f9f41c4 | 831 | sigill_dsp: |
d8d4e3ae | 832 | printk("%s: DSP branch but not DSP ASE - sending SIGBUS.\n", current->comm); |
1da177e4 LT |
833 | force_sig(SIGBUS, current); |
834 | return -EFAULT; | |
5f9f41c4 MC |
835 | sigill_r6: |
836 | pr_info("%s: R2 branch but r2-to-r6 emulator is not preset - sending SIGILL.\n", | |
837 | current->comm); | |
838 | force_sig(SIGILL, current); | |
839 | return -EFAULT; | |
d8d4e3ae MS |
840 | } |
841 | EXPORT_SYMBOL_GPL(__compute_return_epc_for_insn); | |
e50c0a8f | 842 | |
d8d4e3ae MS |
843 | int __compute_return_epc(struct pt_regs *regs) |
844 | { | |
845 | unsigned int __user *addr; | |
846 | long epc; | |
847 | union mips_instruction insn; | |
848 | ||
849 | epc = regs->cp0_epc; | |
850 | if (epc & 3) | |
851 | goto unaligned; | |
852 | ||
853 | /* | |
854 | * Read the instruction | |
855 | */ | |
856 | addr = (unsigned int __user *) epc; | |
857 | if (__get_user(insn.word, addr)) { | |
858 | force_sig(SIGSEGV, current); | |
859 | return -EFAULT; | |
860 | } | |
861 | ||
862 | return __compute_return_epc_for_insn(regs, insn); | |
863 | ||
864 | unaligned: | |
865 | printk("%s: unaligned epc - sending SIGBUS.\n", current->comm); | |
e50c0a8f RB |
866 | force_sig(SIGBUS, current); |
867 | return -EFAULT; | |
1da177e4 | 868 | } |