>> 1 /* SPDX-License-Identifier: GPL-2.0 */
1 /* 2 /*
2 * Low-level exception handling !! 3 * arch/alpha/kernel/entry.S
3 * <<
4 * This file is subject to the terms and condi <<
5 * License. See the file "COPYING" in the mai <<
6 * for more details. <<
7 * <<
8 * Copyright (C) 2004 - 2008 by Tensilica Inc. <<
9 * Copyright (C) 2015 Cadence Design Systems I <<
10 * <<
11 * Chris Zankel <chris@zankel.net> <<
12 * 4 *
>> 5 * Kernel entry-points.
13 */ 6 */
14 7
15 #include <linux/linkage.h> <<
16 #include <linux/pgtable.h> <<
17 #include <asm/asm-offsets.h> 8 #include <asm/asm-offsets.h>
18 #include <asm/asmmacro.h> <<
19 #include <asm/processor.h> <<
20 #include <asm/coprocessor.h> <<
21 #include <asm/thread_info.h> 9 #include <asm/thread_info.h>
22 #include <asm/asm-uaccess.h> !! 10 #include <asm/pal.h>
>> 11 #include <asm/errno.h>
23 #include <asm/unistd.h> 12 #include <asm/unistd.h>
24 #include <asm/ptrace.h> <<
25 #include <asm/current.h> <<
26 #include <asm/page.h> <<
27 #include <asm/signal.h> <<
28 #include <asm/tlbflush.h> <<
29 #include <variant/tie-asm.h> <<
30 <<
31 /* <<
32 * Macro to find first bit set in WINDOWBASE f <<
33 * <<
34 * 100....0 -> 1 <<
35 * 010....0 -> 2 <<
36 * 000....1 -> WSBITS <<
37 */ <<
38 <<
39 .macro ffs_ws bit mask <<
40 <<
41 #if XCHAL_HAVE_NSA <<
42 nsau \bit, \mask <<
43 addi \bit, \bit, WSBITS - 32 + 1 <<
44 #else <<
45 movi \bit, WSBITS <<
46 #if WSBITS > 16 <<
47 _bltui \mask, 0x10000, 99f <<
48 addi \bit, \bit, -16 <<
49 extui \mask, \mask, 16, 16 <<
50 #endif <<
51 #if WSBITS > 8 <<
52 99: _bltui \mask, 0x100, 99f <<
53 addi \bit, \bit, -8 <<
54 srli \mask, \mask, 8 <<
55 #endif <<
56 99: _bltui \mask, 0x10, 99f <<
57 addi \bit, \bit, -4 <<
58 srli \mask, \mask, 4 <<
59 99: _bltui \mask, 0x4, 99f <<
60 addi \bit, \bit, -2 <<
61 srli \mask, \mask, 2 <<
62 99: _bltui \mask, 0x2, 99f <<
63 addi \bit, \bit, -1 <<
64 99: <<
65 <<
66 #endif <<
67 .endm <<
68 <<
69 <<
70 .macro irq_save flags tmp <<
71 #if XTENSA_FAKE_NMI <<
72 #if defined(CONFIG_DEBUG_KERNEL) && (LOCKLEVEL <<
73 rsr \flags, ps <<
74 extui \tmp, \flags, PS_INTLEVEL_SHIF <<
75 bgei \tmp, LOCKLEVEL, 99f <<
76 rsil \tmp, LOCKLEVEL <<
77 99: <<
78 #else <<
79 movi \tmp, LOCKLEVEL <<
80 rsr \flags, ps <<
81 or \flags, \flags, \tmp <<
82 xsr \flags, ps <<
83 rsync <<
84 #endif <<
85 #else <<
86 rsil \flags, LOCKLEVEL <<
87 #endif <<
88 .endm <<
89 <<
90 /* ----------------- DEFAULT FIRST LEVEL EXCEP <<
91 <<
92 /* <<
93 * First-level exception handler for user exce <<
94 * Save some special registers, extra states a <<
95 * register file that were in use in the user <<
96 * exception code. <<
97 * We save SAR (used to calculate WMASK), and <<
98 * save them for kernel exceptions). <<
99 * <<
100 * Entry condition for user_exception: <<
101 * <<
102 * a0: trashed, original value saved <<
103 * a1: a1 <<
104 * a2: new stack pointer, original va <<
105 * a3: a3 <<
106 * depc: a2, original value saved on st <<
107 * excsave1: dispatch table <<
108 * <<
109 * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS <<
110 * < VALID_DOUBLE_EXCEPTION_ADDRESS <<
111 * <<
112 * Entry condition for _user_exception: <<
113 * <<
114 * a0-a3 and depc have been saved to PT_AREG <<
115 * excsave has been restored, and <<
116 * stack pointer (a1) has been set. <<
117 * <<
118 * Note: _user_exception might be at an odd ad <<
119 */ <<
120 .literal_position <<
121 <<
122 ENTRY(user_exception) <<
123 <<
124 /* Save a1, a2, a3, and set SP. */ <<
125 <<
126 rsr a0, depc <<
127 s32i a1, a2, PT_AREG1 <<
128 s32i a0, a2, PT_AREG2 <<
129 s32i a3, a2, PT_AREG3 <<
130 mov a1, a2 <<
131 <<
132 .globl _user_exception <<
133 _user_exception: <<
134 <<
135 /* Save SAR and turn off single steppi <<
136 <<
137 movi a2, 0 <<
138 wsr a2, depc # term <<
139 rsr a3, sar <<
140 xsr a2, icountlevel <<
141 s32i a3, a1, PT_SAR <<
142 s32i a2, a1, PT_ICOUNTLEVEL <<
143 <<
144 #if XCHAL_HAVE_THREADPTR <<
145 rur a2, threadptr <<
146 s32i a2, a1, PT_THREADPTR <<
147 #endif <<
148 <<
149 /* Rotate ws so that the current windo <<
150 /* Assume ws = xxwww1yyyy. Rotate ws r <<
151 <<
152 #if defined(USER_SUPPORT_WINDOWED) <<
153 rsr a2, windowbase <<
154 rsr a3, windowstart <<
155 ssr a2 <<
156 s32i a2, a1, PT_WINDOWBASE <<
157 s32i a3, a1, PT_WINDOWSTART <<
158 slli a2, a3, 32-WSBITS <<
159 src a2, a3, a2 <<
160 srli a2, a2, 32-WSBITS <<
161 s32i a2, a1, PT_WMASK # need <<
162 #else <<
163 movi a2, 0 <<
164 movi a3, 1 <<
165 s32i a2, a1, PT_WINDOWBASE <<
166 s32i a3, a1, PT_WINDOWSTART <<
167 s32i a3, a1, PT_WMASK <<
168 #endif <<
169 <<
170 /* Save only live registers. */ <<
171 <<
172 UABI_W _bbsi.l a2, 1, .Lsave_window_registers <<
173 s32i a4, a1, PT_AREG4 <<
174 s32i a5, a1, PT_AREG5 <<
175 s32i a6, a1, PT_AREG6 <<
176 s32i a7, a1, PT_AREG7 <<
177 UABI_W _bbsi.l a2, 2, .Lsave_window_registers <<
178 s32i a8, a1, PT_AREG8 <<
179 s32i a9, a1, PT_AREG9 <<
180 s32i a10, a1, PT_AREG10 <<
181 s32i a11, a1, PT_AREG11 <<
182 UABI_W _bbsi.l a2, 3, .Lsave_window_registers <<
183 s32i a12, a1, PT_AREG12 <<
184 s32i a13, a1, PT_AREG13 <<
185 s32i a14, a1, PT_AREG14 <<
186 s32i a15, a1, PT_AREG15 <<
187 <<
188 #if defined(USER_SUPPORT_WINDOWED) <<
189 /* If only one valid frame skip saving <<
190 <<
191 beqi a2, 1, common_exception <<
192 <<
193 /* Save the remaining registers. <<
194 * We have to save all registers up to <<
195 * the right, except the current frame <<
196 * Assume a2 is: 001001000110001 <<
197 * All register frames starting from t <<
198 * must be saved. <<
199 */ <<
200 .Lsave_window_registers: <<
201 addi a3, a2, -1 # elim <<
202 neg a3, a3 # yyyy <<
203 and a3, a3, a2 # max. <<
204 <<
205 /* Find number of frames to save */ <<
206 <<
207 ffs_ws a0, a3 # numb <<
208 <<
209 /* Store information into WMASK: <<
210 * bits 0..3: xxx1 masked lower 4 bits <<
211 * bits 4...: number of valid 4-regist <<
212 */ <<
213 <<
214 slli a3, a0, 4 # numb <<
215 extui a2, a2, 0, 4 # mask <<
216 or a2, a3, a2 <<
217 s32i a2, a1, PT_WMASK # need <<
218 <<
219 /* Save 4 registers at a time */ <<
220 <<
221 1: rotw -1 <<
222 s32i a0, a5, PT_AREG_END - 16 <<
223 s32i a1, a5, PT_AREG_END - 12 <<
224 s32i a2, a5, PT_AREG_END - 8 <<
225 s32i a3, a5, PT_AREG_END - 4 <<
226 addi a0, a4, -1 <<
227 addi a1, a5, -16 <<
228 _bnez a0, 1b <<
229 <<
230 /* WINDOWBASE still in SAR! */ <<
231 <<
232 rsr a2, sar # orig <<
233 movi a3, 1 <<
234 ssl a2 <<
235 sll a3, a3 <<
236 wsr a3, windowstart # set <<
237 wsr a2, windowbase # and <<
238 rsync <<
239 <<
240 /* We are back to the original stack p <<
241 #endif <<
242 /* Now, jump to the common exception h <<
243 <<
244 j common_exception <<
245 <<
246 ENDPROC(user_exception) <<
247 <<
248 /* <<
249 * First-level exit handler for kernel excepti <<
250 * Save special registers and the live window <<
251 * Note: Even though we changes the stack poin <<
252 * MOVSP here, as we do that when we ret <<
253 * (See comment in the kernel exception <<
254 * <<
255 * Entry condition for kernel_exception: <<
256 * <<
257 * a0: trashed, original value saved <<
258 * a1: a1 <<
259 * a2: new stack pointer, original in <<
260 * a3: a3 <<
261 * depc: a2, original value saved on st <<
262 * excsave_1: dispatch table <<
263 * <<
264 * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRESS <<
265 * < VALID_DOUBLE_EXCEPTION_ADDRESS <<
266 * <<
267 * Entry condition for _kernel_exception: <<
268 * <<
269 * a0-a3 and depc have been saved to PT_AREG <<
270 * excsave has been restored, and <<
271 * stack pointer (a1) has been set. <<
272 * <<
273 * Note: _kernel_exception might be at an odd <<
274 */ <<
275 <<
276 ENTRY(kernel_exception) <<
277 <<
278 /* Save a1, a2, a3, and set SP. */ <<
279 <<
280 rsr a0, depc # get <<
281 s32i a1, a2, PT_AREG1 <<
282 s32i a0, a2, PT_AREG2 <<
283 s32i a3, a2, PT_AREG3 <<
284 mov a1, a2 <<
285 <<
286 .globl _kernel_exception <<
287 _kernel_exception: <<
288 <<
289 /* Save SAR and turn off single steppi <<
290 <<
291 movi a2, 0 <<
292 rsr a3, sar <<
293 xsr a2, icountlevel <<
294 s32i a3, a1, PT_SAR <<
295 s32i a2, a1, PT_ICOUNTLEVEL <<
296 <<
297 #if defined(__XTENSA_WINDOWED_ABI__) <<
298 /* Rotate ws so that the current windo <<
299 /* Assume ws = xxwww1yyyy. Rotate ws r <<
300 <<
301 rsr a2, windowbase # don' <<
302 rsr a3, windowstart # need <<
303 ssr a2 <<
304 slli a2, a3, 32-WSBITS <<
305 src a2, a3, a2 <<
306 srli a2, a2, 32-WSBITS <<
307 s32i a2, a1, PT_WMASK # need <<
308 #endif <<
309 <<
310 /* Save only the live window-frame */ <<
311 <<
312 KABI_W _bbsi.l a2, 1, 1f <<
313 s32i a4, a1, PT_AREG4 <<
314 s32i a5, a1, PT_AREG5 <<
315 s32i a6, a1, PT_AREG6 <<
316 s32i a7, a1, PT_AREG7 <<
317 KABI_W _bbsi.l a2, 2, 1f <<
318 s32i a8, a1, PT_AREG8 <<
319 s32i a9, a1, PT_AREG9 <<
320 s32i a10, a1, PT_AREG10 <<
321 s32i a11, a1, PT_AREG11 <<
322 KABI_W _bbsi.l a2, 3, 1f <<
323 s32i a12, a1, PT_AREG12 <<
324 s32i a13, a1, PT_AREG13 <<
325 s32i a14, a1, PT_AREG14 <<
326 s32i a15, a1, PT_AREG15 <<
327 <<
328 #ifdef __XTENSA_WINDOWED_ABI__ <<
329 _bnei a2, 1, 1f <<
330 /* Copy spill slots of a0 and a1 to im <<
331 * in order to keep exception stack co <<
332 */ <<
333 l32i a3, a1, PT_KERNEL_SIZE <<
334 l32i a0, a1, PT_KERNEL_SIZE + 4 <<
335 s32e a3, a1, -16 <<
336 s32e a0, a1, -12 <<
337 #endif <<
338 1: <<
339 l32i a0, a1, PT_AREG0 # rest <<
340 wsr a0, depc <<
341 <<
342 /* <<
343 * This is the common exception handler. <<
344 * We get here from the user exception handler <<
345 * from the kernel exception handler. <<
346 * Save the remaining special registers, switc <<
347 * to the second-level exception handler. <<
348 * <<
349 */ <<
350 <<
351 common_exception: <<
352 <<
353 /* Save some registers, disable loops <<
354 <<
355 rsr a2, debugcause <<
356 rsr a3, epc1 <<
357 s32i a2, a1, PT_DEBUGCAUSE <<
358 s32i a3, a1, PT_PC <<
359 <<
360 movi a2, NO_SYSCALL <<
361 rsr a3, excvaddr <<
362 s32i a2, a1, PT_SYSCALL <<
363 movi a2, 0 <<
364 s32i a3, a1, PT_EXCVADDR <<
365 #if XCHAL_HAVE_LOOPS <<
366 xsr a2, lcount <<
367 s32i a2, a1, PT_LCOUNT <<
368 #endif <<
369 <<
370 #if XCHAL_HAVE_EXCLUSIVE <<
371 /* Clear exclusive access monitor set <<
372 clrex <<
373 #endif <<
374 <<
375 /* It is now save to restore the EXC_T <<
376 <<
377 rsr a2, exccause <<
378 movi a3, 0 <<
379 rsr a0, excsave1 <<
380 s32i a2, a1, PT_EXCCAUSE <<
381 s32i a3, a0, EXC_TABLE_FIXUP <<
382 <<
383 /* All unrecoverable states are saved <<
384 * Now we can allow exceptions again. <<
385 * PS.INTLEVEL is set to LOCKLEVEL dis <<
386 * otherwise it's left unchanged. <<
387 * <<
388 * Set PS(EXCM = 0, UM = 0, RING = 0, <<
389 */ <<
390 <<
391 rsr a3, ps <<
392 s32i a3, a1, PT_PS # save <<
393 <<
394 #if XTENSA_FAKE_NMI <<
395 /* Correct PS needs to be saved in the <<
396 * - in case of exception or level-1 i <<
397 * and is already saved. <<
398 * - in case of medium level interrupt <<
399 */ <<
400 movi a0, EXCCAUSE_MAPPED_NMI <<
401 extui a3, a3, PS_INTLEVEL_SHIFT, PS_ <<
402 beq a2, a0, .Lmedium_level_irq <<
403 bnei a2, EXCCAUSE_LEVEL1_INTERRUPT, <<
404 beqz a3, .Llevel1_irq # leve <<
405 <<
406 .Lmedium_level_irq: <<
407 rsr a0, excsave2 <<
408 s32i a0, a1, PT_PS # save <<
409 bgei a3, LOCKLEVEL, .Lexception <<
410 <<
411 .Llevel1_irq: <<
412 movi a3, LOCKLEVEL <<
413 <<
414 .Lexception: <<
415 KABI_W movi a0, PS_WOE_MASK <<
416 KABI_W or a3, a3, a0 <<
417 #else <<
418 addi a2, a2, -EXCCAUSE_LEVEL1_INTER <<
419 movi a0, LOCKLEVEL <<
420 extui a3, a3, PS_INTLEVEL_SHIFT, PS_ <<
421 # a3 = <<
422 moveqz a3, a0, a2 # a3 = <<
423 KABI_W movi a2, PS_WOE_MASK <<
424 KABI_W or a3, a3, a2 <<
425 #endif <<
426 <<
427 /* restore return address (or 0 if ret <<
428 rsr a0, depc <<
429 wsr a3, ps <<
430 rsync # PS.W <<
431 <<
432 /* Save lbeg, lend */ <<
433 #if XCHAL_HAVE_LOOPS <<
434 rsr a4, lbeg <<
435 rsr a3, lend <<
436 s32i a4, a1, PT_LBEG <<
437 s32i a3, a1, PT_LEND <<
438 #endif <<
439 <<
440 /* Save SCOMPARE1 */ <<
441 <<
442 #if XCHAL_HAVE_S32C1I <<
443 rsr a3, scompare1 <<
444 s32i a3, a1, PT_SCOMPARE1 <<
445 #endif <<
446 <<
447 /* Save optional registers. */ <<
448 <<
449 save_xtregs_opt a1 a3 a4 a5 a6 a7 PT_X <<
450 <<
451 #ifdef CONFIG_TRACE_IRQFLAGS <<
452 rsr abi_tmp0, ps <<
453 extui abi_tmp0, abi_tmp0, PS <<
454 beqz abi_tmp0, 1f <<
455 abi_call trace_hardirqs_off <<
456 1: <<
457 #endif <<
458 #ifdef CONFIG_CONTEXT_TRACKING_USER <<
459 l32i abi_tmp0, a1, PT_PS <<
460 bbci.l abi_tmp0, PS_UM_BIT, 1 <<
461 abi_call user_exit_callable <<
462 1: <<
463 #endif <<
464 <<
465 /* Go to second-level dispatcher. Set <<
466 * exception handler and call the exce <<
467 */ <<
468 <<
469 l32i abi_arg1, a1, PT_EXCCA <<
470 rsr abi_tmp0, excsave1 <<
471 addx4 abi_tmp0, abi_arg1, ab <<
472 l32i abi_tmp0, abi_tmp0, EX <<
473 mov abi_arg0, a1 <<
474 <<
475 /* Call the second-level handler */ <<
476 <<
477 abi_callx abi_tmp0 <<
478 <<
479 /* Jump here for exception exit */ <<
480 .global common_exception_return <<
481 common_exception_return: <<
482 <<
483 #if XTENSA_FAKE_NMI <<
484 l32i abi_tmp0, a1, PT_EXCCA <<
485 movi abi_tmp1, EXCCAUSE_MAP <<
486 l32i abi_saved1, a1, PT_PS <<
487 beq abi_tmp0, abi_tmp1, .L <<
488 #endif <<
489 .Ltif_loop: <<
490 irq_save abi_tmp0, abi_tmp1 <<
491 #ifdef CONFIG_TRACE_IRQFLAGS <<
492 abi_call trace_hardirqs_off <<
493 #endif <<
494 <<
495 /* Jump if we are returning from kerne <<
496 <<
497 l32i abi_saved1, a1, PT_PS <<
498 GET_THREAD_INFO(abi_tmp0, a1) <<
499 l32i abi_saved0, abi_tmp0, <<
500 _bbci.l abi_saved1, PS_UM_BIT, <<
501 <<
502 /* Specific to a user exception exit: <<
503 * We need to check some flags for sig <<
504 * and have to restore WB and WS, extr <<
505 * in the register file that were in u <<
506 * Note that we don't disable interrup <<
507 */ <<
508 <<
509 _bbsi.l abi_saved0, TIF_NEED_R <<
510 movi abi_tmp0, _TIF_SIGPEND <<
511 bnone abi_saved0, abi_tmp0, <<
512 <<
513 l32i abi_tmp0, a1, PT_DEPC <<
514 bgeui abi_tmp0, VALID_DOUBLE <<
515 <<
516 /* Call do_signal() */ <<
517 <<
518 #ifdef CONFIG_TRACE_IRQFLAGS <<
519 abi_call trace_hardirqs_on <<
520 #endif <<
521 rsil abi_tmp0, 0 <<
522 mov abi_arg0, a1 <<
523 abi_call do_notify_resume <<
524 j .Ltif_loop <<
525 <<
526 .Lresched: <<
527 #ifdef CONFIG_TRACE_IRQFLAGS <<
528 abi_call trace_hardirqs_on <<
529 #endif <<
530 rsil abi_tmp0, 0 <<
531 abi_call schedule # void <<
532 j .Ltif_loop <<
533 <<
534 .Lexit_tif_loop_kernel: <<
535 #ifdef CONFIG_PREEMPTION <<
536 _bbci.l abi_saved0, TIF_NEED_R <<
537 <<
538 /* Check current_thread_info->preempt_ <<
539 <<
540 l32i abi_tmp1, abi_tmp0, TI <<
541 bnez abi_tmp1, .Lrestore_st <<
542 abi_call preempt_schedule_irq <<
543 #endif <<
544 j .Lrestore_state <<
545 <<
546 .Lexit_tif_loop_user: <<
547 #ifdef CONFIG_CONTEXT_TRACKING_USER <<
548 abi_call user_enter_callable <<
549 #endif <<
550 #ifdef CONFIG_HAVE_HW_BREAKPOINT <<
551 _bbci.l abi_saved0, TIF_DB_DIS <<
552 abi_call restore_dbreak <<
553 1: <<
554 #endif <<
555 #ifdef CONFIG_DEBUG_TLB_SANITY <<
556 l32i abi_tmp0, a1, PT_DEPC <<
557 bgeui abi_tmp0, VALID_DOUBLE <<
558 abi_call check_tlb_sanity <<
559 #endif <<
560 <<
561 .Lrestore_state: <<
562 #ifdef CONFIG_TRACE_IRQFLAGS <<
563 extui abi_tmp0, abi_saved1, <<
564 bgei abi_tmp0, LOCKLEVEL, 1 <<
565 abi_call trace_hardirqs_on <<
566 1: <<
567 #endif <<
568 /* <<
569 * Restore optional registers. <<
570 * abi_arg* are used as temporary regi <<
571 */ <<
572 <<
573 load_xtregs_opt a1 abi_tmp0 abi_arg0 a <<
574 <<
575 /* Restore SCOMPARE1 */ <<
576 <<
577 #if XCHAL_HAVE_S32C1I <<
578 l32i abi_tmp0, a1, PT_SCOMP <<
579 wsr abi_tmp0, scompare1 <<
580 #endif <<
581 wsr abi_saved1, ps <<
582 _bbci.l abi_saved1, PS_UM_BIT, <<
583 <<
584 user_exception_exit: <<
585 <<
586 /* Restore the state of the task and r <<
587 13
588 #if defined(USER_SUPPORT_WINDOWED) !! 14 .text
589 /* Switch to the user thread WINDOWBAS !! 15 .set noat
590 !! 16 .cfi_sections .debug_frame
591 l32i a2, a1, PT_WINDOWBASE <<
592 l32i a3, a1, PT_WINDOWSTART <<
593 wsr a1, depc # use <<
594 wsr a3, windowstart # rest <<
595 ssr a2 # pres <<
596 wsr a2, windowbase # swit <<
597 rsync <<
598 rsr a1, depc # rest <<
599 l32i a2, a1, PT_WMASK # regi <<
600 rotw -1 # we r <<
601 _bltui a6, 16, .Lclear_regs # only <<
602 <<
603 /* The working registers are a0 and a3 <<
604 * a4..a7. Be careful not to destroy <<
605 * Note: wmask has the format YYYYM: <<
606 * Y: number of registers saved <<
607 * M: 4 bit mask of first 16 reg <<
608 */ <<
609 <<
610 mov a2, a6 <<
611 mov a3, a5 <<
612 <<
613 1: rotw -1 # a0.. <<
614 addi a3, a7, -4*4 # next <<
615 addi a2, a6, -16 # decr <<
616 l32i a4, a3, PT_AREG_END + 0 <<
617 l32i a5, a3, PT_AREG_END + 4 <<
618 l32i a6, a3, PT_AREG_END + 8 <<
619 l32i a7, a3, PT_AREG_END + 12 <<
620 _bgeui a2, 16, 1b <<
621 <<
622 /* Clear unrestored registers (don't l <<
623 <<
624 .Lclear_regs: <<
625 rsr a0, windowbase <<
626 rsr a3, sar <<
627 sub a3, a0, a3 <<
628 beqz a3, 2f <<
629 extui a3, a3, 0, WBBITS <<
630 <<
631 1: rotw -1 <<
632 addi a3, a7, -1 <<
633 movi a4, 0 <<
634 movi a5, 0 <<
635 movi a6, 0 <<
636 movi a7, 0 <<
637 bgei a3, 1, 1b <<
638 <<
639 /* We are back were we were when we st <<
640 * Note: a2 still contains WMASK (if w <<
641 * frame where we had loaded a2) <<
642 * (if we have restored WSBITS-1 <<
643 */ <<
644 2: <<
645 #else <<
646 movi a2, 1 <<
647 #endif <<
648 #if XCHAL_HAVE_THREADPTR <<
649 l32i a3, a1, PT_THREADPTR <<
650 wur a3, threadptr <<
651 #endif <<
652 <<
653 j common_exception_exit <<
654 <<
655 /* This is the kernel exception exit. <<
656 * We avoided to do a MOVSP when we en <<
657 * have to do it here. <<
658 */ <<
659 <<
660 kernel_exception_exit: <<
661 <<
662 #if defined(__XTENSA_WINDOWED_ABI__) <<
663 /* Check if we have to do a movsp. <<
664 * <<
665 * We only have to do a movsp if the p <<
666 * been spilled to the *temporary* exc <<
667 * task's stack. This is the case if t <<
668 * WINDOWSTART for the previous window <<
669 * (not spilled) but is zero now (spil <<
670 * If this bit is zero, all other bits <<
671 * current window frame are also zero. <<
672 * 'and' WINDOWSTART and WINDOWSTART-1 <<
673 * <<
674 * (XXXXXX1[0]* - 1) AND XXXXXX1[0]* <<
675 * <<
676 * The result is zero only if one bit <<
677 * <<
678 * (Note: We might have gone through s <<
679 * we come back to the current <<
680 * different from the time the <<
681 */ <<
682 <<
683 /* Test WINDOWSTART before and after t <<
684 * We actually have WMASK, so we only <<
685 */ <<
686 <<
687 l32i a2, a1, PT_WMASK <<
688 _beqi a2, 1, common_exception_exit <<
689 <<
690 /* Test WINDOWSTART now. If spilled, d <<
691 <<
692 rsr a3, windowstart <<
693 addi a0, a3, -1 <<
694 and a3, a3, a0 <<
695 _bnez a3, common_exception_exit <<
696 <<
697 /* Do a movsp (we returned from a call <<
698 <<
699 addi a0, a1, -16 <<
700 l32i a3, a0, 0 <<
701 l32i a4, a0, 4 <<
702 s32i a3, a1, PT_KERNEL_SIZE + 0 <<
703 s32i a4, a1, PT_KERNEL_SIZE + 4 <<
704 l32i a3, a0, 8 <<
705 l32i a4, a0, 12 <<
706 s32i a3, a1, PT_KERNEL_SIZE + 8 <<
707 s32i a4, a1, PT_KERNEL_SIZE + 12 <<
708 <<
709 /* Common exception exit. <<
710 * We restore the special register and <<
711 * return from the exception. <<
712 * <<
713 * Note: We expect a2 to hold PT_WMASK <<
714 */ <<
715 #else <<
716 movi a2, 1 <<
717 #endif <<
718 <<
719 common_exception_exit: <<
720 <<
721 /* Restore address registers. */ <<
722 <<
723 _bbsi.l a2, 1, 1f <<
724 l32i a4, a1, PT_AREG4 <<
725 l32i a5, a1, PT_AREG5 <<
726 l32i a6, a1, PT_AREG6 <<
727 l32i a7, a1, PT_AREG7 <<
728 _bbsi.l a2, 2, 1f <<
729 l32i a8, a1, PT_AREG8 <<
730 l32i a9, a1, PT_AREG9 <<
731 l32i a10, a1, PT_AREG10 <<
732 l32i a11, a1, PT_AREG11 <<
733 _bbsi.l a2, 3, 1f <<
734 l32i a12, a1, PT_AREG12 <<
735 l32i a13, a1, PT_AREG13 <<
736 l32i a14, a1, PT_AREG14 <<
737 l32i a15, a1, PT_AREG15 <<
738 <<
739 /* Restore PC, SAR */ <<
740 <<
741 1: l32i a2, a1, PT_PC <<
742 l32i a3, a1, PT_SAR <<
743 wsr a2, epc1 <<
744 wsr a3, sar <<
745 <<
746 /* Restore LBEG, LEND, LCOUNT */ <<
747 #if XCHAL_HAVE_LOOPS <<
748 l32i a2, a1, PT_LBEG <<
749 l32i a3, a1, PT_LEND <<
750 wsr a2, lbeg <<
751 l32i a2, a1, PT_LCOUNT <<
752 wsr a3, lend <<
753 wsr a2, lcount <<
754 #endif <<
755 <<
756 /* We control single stepping through <<
757 <<
758 l32i a2, a1, PT_ICOUNTLEVEL <<
759 movi a3, -2 <<
760 wsr a2, icountlevel <<
761 wsr a3, icount <<
762 <<
763 /* Check if it was double exception. * <<
764 <<
765 l32i a0, a1, PT_DEPC <<
766 l32i a3, a1, PT_AREG3 <<
767 l32i a2, a1, PT_AREG2 <<
768 _bgeui a0, VALID_DOUBLE_EXCEPTION_ADD <<
769 <<
770 /* Restore a0...a3 and return */ <<
771 <<
772 l32i a0, a1, PT_AREG0 <<
773 l32i a1, a1, PT_AREG1 <<
774 rfe <<
775 <<
776 1: wsr a0, depc <<
777 l32i a0, a1, PT_AREG0 <<
778 l32i a1, a1, PT_AREG1 <<
779 rfde <<
780 <<
781 ENDPROC(kernel_exception) <<
782 <<
783 /* <<
784 * Debug exception handler. <<
785 * <<
786 * Currently, we don't support KGDB, so only u <<
787 * <<
788 * When we get here, a0 is trashed and saved <<
789 */ <<
790 <<
791 .literal_position <<
792 <<
793 ENTRY(debug_exception) <<
794 <<
795 rsr a0, SREG_EPS + XCHAL_DEBUGLEVE <<
796 bbsi.l a0, PS_EXCM_BIT, .Ldebug_excep <<
797 <<
798 /* Set EPC1 and EXCCAUSE */ <<
799 <<
800 wsr a2, depc # save <<
801 rsr a2, SREG_EPC + XCHAL_DEBUGLEVE <<
802 wsr a2, epc1 <<
803 <<
804 movi a2, EXCCAUSE_MAPPED_DEBUG <<
805 wsr a2, exccause <<
806 <<
807 /* Restore PS to the value before the <<
808 <<
809 movi a2, 1 << PS_EXCM_BIT <<
810 or a2, a0, a2 <<
811 wsr a2, ps <<
812 <<
813 /* Switch to kernel/user stack, restor <<
814 <<
815 bbsi.l a2, PS_UM_BIT, .Ldebug_excepti <<
816 addi a2, a1, -16 - PT_KERNEL_SIZE <<
817 <<
818 .Ldebug_exception_continue: <<
819 l32i a0, a3, DT_DEBUG_SAVE <<
820 s32i a1, a2, PT_AREG1 <<
821 s32i a0, a2, PT_AREG0 <<
822 movi a0, 0 <<
823 s32i a0, a2, PT_DEPC # mark <<
824 xsr a3, SREG_EXCSAVE + XCHAL_DEBUG <<
825 xsr a0, depc <<
826 s32i a3, a2, PT_AREG3 <<
827 s32i a0, a2, PT_AREG2 <<
828 mov a1, a2 <<
829 <<
830 /* Debug exception is handled as an ex <<
831 * likely be enabled in the common exc <<
832 * preemption if we have HW breakpoint <<
833 * meaning. <<
834 */ <<
835 #if defined(CONFIG_PREEMPT_COUNT) && defined(C <<
836 GET_THREAD_INFO(a2, a1) <<
837 l32i a3, a2, TI_PRE_COUNT <<
838 addi a3, a3, 1 <<
839 s32i a3, a2, TI_PRE_COUNT <<
840 #endif <<
841 <<
842 rsr a2, ps <<
843 bbsi.l a2, PS_UM_BIT, _user_exception <<
844 j _kernel_exception <<
845 <<
846 .Ldebug_exception_user: <<
847 rsr a2, excsave1 <<
848 l32i a2, a2, EXC_TABLE_KSTK # load <<
849 j .Ldebug_exception_continue <<
850 <<
851 .Ldebug_exception_in_exception: <<
852 #ifdef CONFIG_HAVE_HW_BREAKPOINT <<
853 /* Debug exception while in exception <<
854 * window overflow/underflow handler o <<
855 * data breakpoint, in which case save <<
856 * breakpoints, single-step faulting i <<
857 * breakpoints. <<
858 */ <<
859 <<
860 bbci.l a0, PS_UM_BIT, .Ldebug_excepti <<
861 <<
862 rsr a0, debugcause <<
863 bbsi.l a0, DEBUGCAUSE_DBREAK_BIT, .Ld <<
864 <<
865 .set _index, 0 <<
866 .rept XCHAL_NUM_DBREAK <<
867 l32i a0, a3, DT_DBREAKC_SAVE + _ind <<
868 wsr a0, SREG_DBREAKC + _index <<
869 .set _index, _index + 1 <<
870 .endr <<
871 <<
872 l32i a0, a3, DT_ICOUNT_LEVEL_SAVE <<
873 wsr a0, icountlevel <<
874 <<
875 l32i a0, a3, DT_ICOUNT_SAVE <<
876 xsr a0, icount <<
877 <<
878 l32i a0, a3, DT_DEBUG_SAVE <<
879 xsr a3, SREG_EXCSAVE + XCHAL_DEBUG <<
880 rfi XCHAL_DEBUGLEVEL <<
881 <<
882 .Ldebug_save_dbreak: <<
883 .set _index, 0 <<
884 .rept XCHAL_NUM_DBREAK <<
885 movi a0, 0 <<
886 xsr a0, SREG_DBREAKC + _index <<
887 s32i a0, a3, DT_DBREAKC_SAVE + _ind <<
888 .set _index, _index + 1 <<
889 .endr <<
890 <<
891 movi a0, XCHAL_EXCM_LEVEL + 1 <<
892 xsr a0, icountlevel <<
893 s32i a0, a3, DT_ICOUNT_LEVEL_SAVE <<
894 <<
895 movi a0, 0xfffffffe <<
896 xsr a0, icount <<
897 s32i a0, a3, DT_ICOUNT_SAVE <<
898 <<
899 l32i a0, a3, DT_DEBUG_SAVE <<
900 xsr a3, SREG_EXCSAVE + XCHAL_DEBUG <<
901 rfi XCHAL_DEBUGLEVEL <<
902 #else <<
903 /* Debug exception while in exception <<
904 j .Ldebug_exception_in_exception <<
905 #endif <<
906 <<
907 ENDPROC(debug_exception) <<
908 <<
909 /* <<
910 * We get here in case of an unrecoverable exc <<
911 * The only thing we can do is to be nice and <<
912 * We only produce a single stack frame for pa <<
913 * <<
914 * <<
915 * Entry conditions: <<
916 * <<
917 * - a0 contains the caller address; origina <<
918 * - the original a0 contains a valid return <<
919 * - a2 contains a valid stackpointer <<
920 * <<
921 * Notes: <<
922 * <<
923 * - If the stack pointer could be invalid, <<
924 * dummy stack pointer (e.g. the stack of <<
925 * <<
926 * - If the return address could be invalid, <<
927 * to 0, so the backtrace would stop. <<
928 * <<
929 */ <<
930 .align 4 <<
931 unrecoverable_text: <<
932 .ascii "Unrecoverable error in excepti <<
933 <<
934 .literal_position <<
935 <<
936 ENTRY(unrecoverable_exception) <<
937 <<
938 #if XCHAL_HAVE_WINDOWED <<
939 movi a0, 1 <<
940 movi a1, 0 <<
941 <<
942 wsr a0, windowstart <<
943 wsr a1, windowbase <<
944 rsync <<
945 #endif <<
946 <<
947 movi a1, KERNEL_PS_WOE_MASK | LOCKL <<
948 wsr a1, ps <<
949 rsync <<
950 <<
951 movi a1, init_task <<
952 movi a0, 0 <<
953 addi a1, a1, PT_REGS_OFFSET <<
954 <<
955 movi abi_arg0, unrecoverable_text <<
956 abi_call panic <<
957 <<
958 1: j 1b <<
959 <<
960 ENDPROC(unrecoverable_exception) <<
961 <<
962 /* -------------------------- FAST EXCEPTION H <<
963 <<
964 __XTENSA_HANDLER <<
965 .literal_position <<
966 17
967 #ifdef SUPPORT_WINDOWED !! 18 /* Stack offsets. */
968 /* !! 19 #define SP_OFF 184
969 * Fast-handler for alloca exceptions !! 20 #define SWITCH_STACK_SIZE 64
970 * <<
971 * The ALLOCA handler is entered when user co <<
972 * instruction and the caller's frame is not <<
973 * <<
974 * This algorithm was taken from the Ross Morl <<
975 * <<
976 * /home/ross/rtos/porting/XtensaRTOS-Porti <<
977 * <<
978 * It leverages the existing window spill/fill <<
979 * double exceptions. The 'movsp' instruction <<
980 * the next window needs to be loaded. In fact <<
981 * replaced at some point by changing the hard <<
982 * of the proper size instead. <<
983 * <<
984 * This algorithm simply backs out the registe <<
985 * exception handler, makes it appear that we <<
986 * by rotating the window back and then settin <<
987 * the 'ps' register with the rolled back wind <<
988 * will be re-executed and this time since the <<
989 * active AR registers it won't cause an excep <<
990 * <<
991 * If the WindowUnderflow code gets a TLB miss <<
992 * the partial WindowUnderflow will be handled <<
993 * handler. <<
994 * <<
995 * Entry condition: <<
996 * <<
997 * a0: trashed, original value saved <<
998 * a1: a1 <<
999 * a2: new stack pointer, original in <<
1000 * a3: a3 <<
1001 * depc: a2, original value saved on s <<
1002 * excsave_1: dispatch table <<
1003 * <<
1004 * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRES <<
1005 * < VALID_DOUBLE_EXCEPTION_ADDRES <<
1006 */ <<
1007 21
1008 ENTRY(fast_alloca) !! 22 .macro CFI_START_OSF_FRAME func
1009 rsr a0, windowbase !! 23 .align 4
1010 rotw -1 !! 24 .globl \func
1011 rsr a2, ps !! 25 .type \func,@function
1012 extui a3, a2, PS_OWB_SHIFT, PS_OWB_ !! 26 \func:
1013 xor a3, a3, a4 !! 27 .cfi_startproc simple
1014 l32i a4, a6, PT_AREG0 !! 28 .cfi_return_column 64
1015 l32i a1, a6, PT_DEPC !! 29 .cfi_def_cfa $sp, 48
1016 rsr a6, depc !! 30 .cfi_rel_offset 64, 8
1017 wsr a1, depc !! 31 .cfi_rel_offset $gp, 16
1018 slli a3, a3, PS_OWB_SHIFT !! 32 .cfi_rel_offset $16, 24
1019 xor a2, a2, a3 !! 33 .cfi_rel_offset $17, 32
1020 wsr a2, ps !! 34 .cfi_rel_offset $18, 40
1021 rsync !! 35 .endm
1022 !! 36
1023 _bbci.l a4, 31, 4f !! 37 .macro CFI_END_OSF_FRAME func
1024 rotw -1 !! 38 .cfi_endproc
1025 _bbci.l a8, 30, 8f !! 39 .size \func, . - \func
1026 rotw -1 !! 40 .endm
1027 j _WindowUnderflow12 !! 41
1028 8: j _WindowUnderflow8 !! 42 /*
1029 4: j _WindowUnderflow4 !! 43 * This defines the normal kernel pt-regs layout.
1030 ENDPROC(fast_alloca) !! 44 *
1031 #endif !! 45 * regs 9-15 preserved by C code
>> 46 * regs 16-18 saved by PAL-code
>> 47 * regs 29-30 saved and set up by PAL-code
>> 48 * JRP - Save regs 16-18 in a special area of the stack, so that
>> 49 * the palcode-provided values are available to the signal handler.
>> 50 */
>> 51
>> 52 .macro SAVE_ALL
>> 53 subq $sp, SP_OFF, $sp
>> 54 .cfi_adjust_cfa_offset SP_OFF
>> 55 stq $0, 0($sp)
>> 56 stq $1, 8($sp)
>> 57 stq $2, 16($sp)
>> 58 stq $3, 24($sp)
>> 59 stq $4, 32($sp)
>> 60 stq $28, 144($sp)
>> 61 .cfi_rel_offset $0, 0
>> 62 .cfi_rel_offset $1, 8
>> 63 .cfi_rel_offset $2, 16
>> 64 .cfi_rel_offset $3, 24
>> 65 .cfi_rel_offset $4, 32
>> 66 .cfi_rel_offset $28, 144
>> 67 lda $2, alpha_mv
>> 68 stq $5, 40($sp)
>> 69 stq $6, 48($sp)
>> 70 stq $7, 56($sp)
>> 71 stq $8, 64($sp)
>> 72 stq $19, 72($sp)
>> 73 stq $20, 80($sp)
>> 74 stq $21, 88($sp)
>> 75 ldq $2, HAE_CACHE($2)
>> 76 stq $22, 96($sp)
>> 77 stq $23, 104($sp)
>> 78 stq $24, 112($sp)
>> 79 stq $25, 120($sp)
>> 80 stq $26, 128($sp)
>> 81 stq $27, 136($sp)
>> 82 stq $2, 152($sp)
>> 83 stq $16, 160($sp)
>> 84 stq $17, 168($sp)
>> 85 stq $18, 176($sp)
>> 86 .cfi_rel_offset $5, 40
>> 87 .cfi_rel_offset $6, 48
>> 88 .cfi_rel_offset $7, 56
>> 89 .cfi_rel_offset $8, 64
>> 90 .cfi_rel_offset $19, 72
>> 91 .cfi_rel_offset $20, 80
>> 92 .cfi_rel_offset $21, 88
>> 93 .cfi_rel_offset $22, 96
>> 94 .cfi_rel_offset $23, 104
>> 95 .cfi_rel_offset $24, 112
>> 96 .cfi_rel_offset $25, 120
>> 97 .cfi_rel_offset $26, 128
>> 98 .cfi_rel_offset $27, 136
>> 99 .endm
>> 100
>> 101 .macro RESTORE_ALL
>> 102 lda $19, alpha_mv
>> 103 ldq $0, 0($sp)
>> 104 ldq $1, 8($sp)
>> 105 ldq $2, 16($sp)
>> 106 ldq $3, 24($sp)
>> 107 ldq $21, 152($sp)
>> 108 ldq $20, HAE_CACHE($19)
>> 109 ldq $4, 32($sp)
>> 110 ldq $5, 40($sp)
>> 111 ldq $6, 48($sp)
>> 112 ldq $7, 56($sp)
>> 113 subq $20, $21, $20
>> 114 ldq $8, 64($sp)
>> 115 beq $20, 99f
>> 116 ldq $20, HAE_REG($19)
>> 117 stq $21, HAE_CACHE($19)
>> 118 stq $21, 0($20)
>> 119 99: ldq $19, 72($sp)
>> 120 ldq $20, 80($sp)
>> 121 ldq $21, 88($sp)
>> 122 ldq $22, 96($sp)
>> 123 ldq $23, 104($sp)
>> 124 ldq $24, 112($sp)
>> 125 ldq $25, 120($sp)
>> 126 ldq $26, 128($sp)
>> 127 ldq $27, 136($sp)
>> 128 ldq $28, 144($sp)
>> 129 addq $sp, SP_OFF, $sp
>> 130 .cfi_restore $0
>> 131 .cfi_restore $1
>> 132 .cfi_restore $2
>> 133 .cfi_restore $3
>> 134 .cfi_restore $4
>> 135 .cfi_restore $5
>> 136 .cfi_restore $6
>> 137 .cfi_restore $7
>> 138 .cfi_restore $8
>> 139 .cfi_restore $19
>> 140 .cfi_restore $20
>> 141 .cfi_restore $21
>> 142 .cfi_restore $22
>> 143 .cfi_restore $23
>> 144 .cfi_restore $24
>> 145 .cfi_restore $25
>> 146 .cfi_restore $26
>> 147 .cfi_restore $27
>> 148 .cfi_restore $28
>> 149 .cfi_adjust_cfa_offset -SP_OFF
>> 150 .endm
>> 151
>> 152 .macro DO_SWITCH_STACK
>> 153 bsr $1, do_switch_stack
>> 154 .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
>> 155 .cfi_rel_offset $9, 0
>> 156 .cfi_rel_offset $10, 8
>> 157 .cfi_rel_offset $11, 16
>> 158 .cfi_rel_offset $12, 24
>> 159 .cfi_rel_offset $13, 32
>> 160 .cfi_rel_offset $14, 40
>> 161 .cfi_rel_offset $15, 48
>> 162 .endm
>> 163
>> 164 .macro UNDO_SWITCH_STACK
>> 165 bsr $1, undo_switch_stack
>> 166 .cfi_restore $9
>> 167 .cfi_restore $10
>> 168 .cfi_restore $11
>> 169 .cfi_restore $12
>> 170 .cfi_restore $13
>> 171 .cfi_restore $14
>> 172 .cfi_restore $15
>> 173 .cfi_adjust_cfa_offset -SWITCH_STACK_SIZE
>> 174 .endm
>> 175
>> 176 /*
>> 177 * Non-syscall kernel entry points.
>> 178 */
>> 179
>> 180 CFI_START_OSF_FRAME entInt
>> 181 SAVE_ALL
>> 182 lda $8, 0x3fff
>> 183 lda $26, ret_from_sys_call
>> 184 bic $sp, $8, $8
>> 185 mov $sp, $19
>> 186 jsr $31, do_entInt
>> 187 CFI_END_OSF_FRAME entInt
>> 188
>> 189 CFI_START_OSF_FRAME entArith
>> 190 SAVE_ALL
>> 191 lda $8, 0x3fff
>> 192 lda $26, ret_from_sys_call
>> 193 bic $sp, $8, $8
>> 194 mov $sp, $18
>> 195 jsr $31, do_entArith
>> 196 CFI_END_OSF_FRAME entArith
>> 197
>> 198 CFI_START_OSF_FRAME entMM
>> 199 SAVE_ALL
>> 200 /* save $9 - $15 so the inline exception code can manipulate them. */
>> 201 subq $sp, 56, $sp
>> 202 .cfi_adjust_cfa_offset 56
>> 203 stq $9, 0($sp)
>> 204 stq $10, 8($sp)
>> 205 stq $11, 16($sp)
>> 206 stq $12, 24($sp)
>> 207 stq $13, 32($sp)
>> 208 stq $14, 40($sp)
>> 209 stq $15, 48($sp)
>> 210 .cfi_rel_offset $9, 0
>> 211 .cfi_rel_offset $10, 8
>> 212 .cfi_rel_offset $11, 16
>> 213 .cfi_rel_offset $12, 24
>> 214 .cfi_rel_offset $13, 32
>> 215 .cfi_rel_offset $14, 40
>> 216 .cfi_rel_offset $15, 48
>> 217 addq $sp, 56, $19
>> 218 /* handle the fault */
>> 219 lda $8, 0x3fff
>> 220 bic $sp, $8, $8
>> 221 jsr $26, do_page_fault
>> 222 /* reload the registers after the exception code played. */
>> 223 ldq $9, 0($sp)
>> 224 ldq $10, 8($sp)
>> 225 ldq $11, 16($sp)
>> 226 ldq $12, 24($sp)
>> 227 ldq $13, 32($sp)
>> 228 ldq $14, 40($sp)
>> 229 ldq $15, 48($sp)
>> 230 addq $sp, 56, $sp
>> 231 .cfi_restore $9
>> 232 .cfi_restore $10
>> 233 .cfi_restore $11
>> 234 .cfi_restore $12
>> 235 .cfi_restore $13
>> 236 .cfi_restore $14
>> 237 .cfi_restore $15
>> 238 .cfi_adjust_cfa_offset -56
>> 239 /* finish up the syscall as normal. */
>> 240 br ret_from_sys_call
>> 241 CFI_END_OSF_FRAME entMM
>> 242
>> 243 CFI_START_OSF_FRAME entIF
>> 244 SAVE_ALL
>> 245 lda $8, 0x3fff
>> 246 lda $26, ret_from_sys_call
>> 247 bic $sp, $8, $8
>> 248 mov $sp, $17
>> 249 jsr $31, do_entIF
>> 250 CFI_END_OSF_FRAME entIF
>> 251
>> 252 CFI_START_OSF_FRAME entUna
>> 253 lda $sp, -256($sp)
>> 254 .cfi_adjust_cfa_offset 256
>> 255 stq $0, 0($sp)
>> 256 .cfi_rel_offset $0, 0
>> 257 .cfi_remember_state
>> 258 ldq $0, 256($sp) /* get PS */
>> 259 stq $1, 8($sp)
>> 260 stq $2, 16($sp)
>> 261 stq $3, 24($sp)
>> 262 and $0, 8, $0 /* user mode? */
>> 263 stq $4, 32($sp)
>> 264 bne $0, entUnaUser /* yup -> do user-level unaligned fault */
>> 265 stq $5, 40($sp)
>> 266 stq $6, 48($sp)
>> 267 stq $7, 56($sp)
>> 268 stq $8, 64($sp)
>> 269 stq $9, 72($sp)
>> 270 stq $10, 80($sp)
>> 271 stq $11, 88($sp)
>> 272 stq $12, 96($sp)
>> 273 stq $13, 104($sp)
>> 274 stq $14, 112($sp)
>> 275 stq $15, 120($sp)
>> 276 /* 16-18 PAL-saved */
>> 277 stq $19, 152($sp)
>> 278 stq $20, 160($sp)
>> 279 stq $21, 168($sp)
>> 280 stq $22, 176($sp)
>> 281 stq $23, 184($sp)
>> 282 stq $24, 192($sp)
>> 283 stq $25, 200($sp)
>> 284 stq $26, 208($sp)
>> 285 stq $27, 216($sp)
>> 286 stq $28, 224($sp)
>> 287 mov $sp, $19
>> 288 stq $gp, 232($sp)
>> 289 .cfi_rel_offset $1, 1*8
>> 290 .cfi_rel_offset $2, 2*8
>> 291 .cfi_rel_offset $3, 3*8
>> 292 .cfi_rel_offset $4, 4*8
>> 293 .cfi_rel_offset $5, 5*8
>> 294 .cfi_rel_offset $6, 6*8
>> 295 .cfi_rel_offset $7, 7*8
>> 296 .cfi_rel_offset $8, 8*8
>> 297 .cfi_rel_offset $9, 9*8
>> 298 .cfi_rel_offset $10, 10*8
>> 299 .cfi_rel_offset $11, 11*8
>> 300 .cfi_rel_offset $12, 12*8
>> 301 .cfi_rel_offset $13, 13*8
>> 302 .cfi_rel_offset $14, 14*8
>> 303 .cfi_rel_offset $15, 15*8
>> 304 .cfi_rel_offset $19, 19*8
>> 305 .cfi_rel_offset $20, 20*8
>> 306 .cfi_rel_offset $21, 21*8
>> 307 .cfi_rel_offset $22, 22*8
>> 308 .cfi_rel_offset $23, 23*8
>> 309 .cfi_rel_offset $24, 24*8
>> 310 .cfi_rel_offset $25, 25*8
>> 311 .cfi_rel_offset $26, 26*8
>> 312 .cfi_rel_offset $27, 27*8
>> 313 .cfi_rel_offset $28, 28*8
>> 314 .cfi_rel_offset $29, 29*8
>> 315 lda $8, 0x3fff
>> 316 stq $31, 248($sp)
>> 317 bic $sp, $8, $8
>> 318 jsr $26, do_entUna
>> 319 ldq $0, 0($sp)
>> 320 ldq $1, 8($sp)
>> 321 ldq $2, 16($sp)
>> 322 ldq $3, 24($sp)
>> 323 ldq $4, 32($sp)
>> 324 ldq $5, 40($sp)
>> 325 ldq $6, 48($sp)
>> 326 ldq $7, 56($sp)
>> 327 ldq $8, 64($sp)
>> 328 ldq $9, 72($sp)
>> 329 ldq $10, 80($sp)
>> 330 ldq $11, 88($sp)
>> 331 ldq $12, 96($sp)
>> 332 ldq $13, 104($sp)
>> 333 ldq $14, 112($sp)
>> 334 ldq $15, 120($sp)
>> 335 /* 16-18 PAL-saved */
>> 336 ldq $19, 152($sp)
>> 337 ldq $20, 160($sp)
>> 338 ldq $21, 168($sp)
>> 339 ldq $22, 176($sp)
>> 340 ldq $23, 184($sp)
>> 341 ldq $24, 192($sp)
>> 342 ldq $25, 200($sp)
>> 343 ldq $26, 208($sp)
>> 344 ldq $27, 216($sp)
>> 345 ldq $28, 224($sp)
>> 346 ldq $gp, 232($sp)
>> 347 lda $sp, 256($sp)
>> 348 .cfi_restore $1
>> 349 .cfi_restore $2
>> 350 .cfi_restore $3
>> 351 .cfi_restore $4
>> 352 .cfi_restore $5
>> 353 .cfi_restore $6
>> 354 .cfi_restore $7
>> 355 .cfi_restore $8
>> 356 .cfi_restore $9
>> 357 .cfi_restore $10
>> 358 .cfi_restore $11
>> 359 .cfi_restore $12
>> 360 .cfi_restore $13
>> 361 .cfi_restore $14
>> 362 .cfi_restore $15
>> 363 .cfi_restore $19
>> 364 .cfi_restore $20
>> 365 .cfi_restore $21
>> 366 .cfi_restore $22
>> 367 .cfi_restore $23
>> 368 .cfi_restore $24
>> 369 .cfi_restore $25
>> 370 .cfi_restore $26
>> 371 .cfi_restore $27
>> 372 .cfi_restore $28
>> 373 .cfi_restore $29
>> 374 .cfi_adjust_cfa_offset -256
>> 375 call_pal PAL_rti
1032 376
1033 #ifdef CONFIG_USER_ABI_CALL0_PROBE !! 377 .align 4
1034 /* !! 378 entUnaUser:
1035 * fast illegal instruction handler. !! 379 .cfi_restore_state
1036 * !! 380 ldq $0, 0($sp) /* restore original $0 */
1037 * This is used to fix up user PS.WOE on the !! 381 lda $sp, 256($sp) /* pop entUna's stack frame */
1038 * by the first opcode related to register wi !! 382 .cfi_restore $0
1039 * already set it goes directly to the common !! 383 .cfi_adjust_cfa_offset -256
>> 384 SAVE_ALL /* setup normal kernel stack */
>> 385 lda $sp, -56($sp)
>> 386 .cfi_adjust_cfa_offset 56
>> 387 stq $9, 0($sp)
>> 388 stq $10, 8($sp)
>> 389 stq $11, 16($sp)
>> 390 stq $12, 24($sp)
>> 391 stq $13, 32($sp)
>> 392 stq $14, 40($sp)
>> 393 stq $15, 48($sp)
>> 394 .cfi_rel_offset $9, 0
>> 395 .cfi_rel_offset $10, 8
>> 396 .cfi_rel_offset $11, 16
>> 397 .cfi_rel_offset $12, 24
>> 398 .cfi_rel_offset $13, 32
>> 399 .cfi_rel_offset $14, 40
>> 400 .cfi_rel_offset $15, 48
>> 401 lda $8, 0x3fff
>> 402 addq $sp, 56, $19
>> 403 bic $sp, $8, $8
>> 404 jsr $26, do_entUnaUser
>> 405 ldq $9, 0($sp)
>> 406 ldq $10, 8($sp)
>> 407 ldq $11, 16($sp)
>> 408 ldq $12, 24($sp)
>> 409 ldq $13, 32($sp)
>> 410 ldq $14, 40($sp)
>> 411 ldq $15, 48($sp)
>> 412 lda $sp, 56($sp)
>> 413 .cfi_restore $9
>> 414 .cfi_restore $10
>> 415 .cfi_restore $11
>> 416 .cfi_restore $12
>> 417 .cfi_restore $13
>> 418 .cfi_restore $14
>> 419 .cfi_restore $15
>> 420 .cfi_adjust_cfa_offset -56
>> 421 br ret_from_sys_call
>> 422 CFI_END_OSF_FRAME entUna
>> 423
>> 424 CFI_START_OSF_FRAME entDbg
>> 425 SAVE_ALL
>> 426 lda $8, 0x3fff
>> 427 lda $26, ret_from_sys_call
>> 428 bic $sp, $8, $8
>> 429 mov $sp, $16
>> 430 jsr $31, do_entDbg
>> 431 CFI_END_OSF_FRAME entDbg
>> 432
>> 433 /*
>> 434 * The system call entry point is special. Most importantly, it looks
>> 435 * like a function call to userspace as far as clobbered registers. We
>> 436 * do preserve the argument registers (for syscall restarts) and $26
>> 437 * (for leaf syscall functions).
1040 * 438 *
1041 * Entry condition: !! 439 * So much for theory. We don't take advantage of this yet.
1042 * 440 *
1043 * a0: trashed, original value saved !! 441 * Note that a0-a2 are not saved by PALcode as with the other entry points.
1044 * a1: a1 <<
1045 * a2: new stack pointer, original i <<
1046 * a3: a3 <<
1047 * depc: a2, original value saved on s <<
1048 * excsave_1: dispatch table <<
1049 */ 442 */
1050 443
1051 ENTRY(fast_illegal_instruction_user) !! 444 .align 4
1052 !! 445 .globl entSys
1053 rsr a0, ps !! 446 .type entSys, @function
1054 bbsi.l a0, PS_WOE_BIT, 1f !! 447 .cfi_startproc simple
1055 s32i a3, a2, PT_AREG3 !! 448 .cfi_return_column 64
1056 movi a3, PS_WOE_MASK !! 449 .cfi_def_cfa $sp, 48
1057 or a0, a0, a3 !! 450 .cfi_rel_offset 64, 8
1058 wsr a0, ps !! 451 .cfi_rel_offset $gp, 16
1059 #ifdef CONFIG_USER_ABI_CALL0_PROBE !! 452 entSys:
1060 GET_THREAD_INFO(a3, a2) !! 453 SAVE_ALL
1061 rsr a0, epc1 !! 454 lda $8, 0x3fff
1062 s32i a0, a3, TI_PS_WOE_FIX_ADDR !! 455 bic $sp, $8, $8
1063 #endif !! 456 lda $4, NR_syscalls($31)
1064 l32i a3, a2, PT_AREG3 !! 457 stq $16, SP_OFF+24($sp)
1065 l32i a0, a2, PT_AREG0 !! 458 lda $5, sys_call_table
1066 rsr a2, depc !! 459 lda $27, sys_ni_syscall
1067 rfe !! 460 cmpult $0, $4, $4
1068 1: !! 461 ldl $3, TI_FLAGS($8)
1069 call0 user_exception !! 462 stq $17, SP_OFF+32($sp)
>> 463 s8addq $0, $5, $5
>> 464 stq $18, SP_OFF+40($sp)
>> 465 .cfi_rel_offset $16, SP_OFF+24
>> 466 .cfi_rel_offset $17, SP_OFF+32
>> 467 .cfi_rel_offset $18, SP_OFF+40
>> 468 #ifdef CONFIG_AUDITSYSCALL
>> 469 lda $6, _TIF_SYSCALL_TRACE | _TIF_SYSCALL_AUDIT
>> 470 and $3, $6, $3
>> 471 bne $3, strace
>> 472 #else
>> 473 blbs $3, strace /* check for SYSCALL_TRACE in disguise */
>> 474 #endif
>> 475 beq $4, 1f
>> 476 ldq $27, 0($5)
>> 477 1: jsr $26, ($27), sys_ni_syscall
>> 478 ldgp $gp, 0($26)
>> 479 blt $0, $syscall_error /* the call failed */
>> 480 $ret_success:
>> 481 stq $0, 0($sp)
>> 482 stq $31, 72($sp) /* a3=0 => no error */
1070 483
1071 ENDPROC(fast_illegal_instruction_user) !! 484 .align 4
1072 #endif !! 485 .globl ret_from_sys_call
>> 486 ret_from_sys_call:
>> 487 cmovne $26, 0, $18 /* $18 = 0 => non-restartable */
>> 488 ldq $0, SP_OFF($sp)
>> 489 and $0, 8, $0
>> 490 beq $0, ret_to_kernel
>> 491 ret_to_user:
>> 492 /* Make sure need_resched and sigpending don't change between
>> 493 sampling and the rti. */
>> 494 lda $16, 7
>> 495 call_pal PAL_swpipl
>> 496 ldl $17, TI_FLAGS($8)
>> 497 and $17, _TIF_WORK_MASK, $2
>> 498 bne $2, work_pending
>> 499 restore_all:
>> 500 ldl $2, TI_STATUS($8)
>> 501 and $2, TS_SAVED_FP | TS_RESTORE_FP, $3
>> 502 bne $3, restore_fpu
>> 503 restore_other:
>> 504 .cfi_remember_state
>> 505 RESTORE_ALL
>> 506 call_pal PAL_rti
>> 507
>> 508 ret_to_kernel:
>> 509 .cfi_restore_state
>> 510 lda $16, 7
>> 511 call_pal PAL_swpipl
>> 512 br restore_other
1073 513
>> 514 .align 3
>> 515 $syscall_error:
1074 /* 516 /*
1075 * fast system calls. !! 517 * Some system calls (e.g., ptrace) can return arbitrary
1076 * !! 518 * values which might normally be mistaken as error numbers.
1077 * WARNING: The kernel doesn't save the enti !! 519 * Those functions must zero $0 (v0) directly in the stack
1078 * handling a fast system call. These functi !! 520 * frame to indicate that a negative return value wasn't an
1079 * usually offering some functionality not av !! 521 * error number..
1080 * !! 522 */
1081 * BE CAREFUL TO PRESERVE THE USER'S CONTEXT. !! 523 ldq $18, 0($sp) /* old syscall nr (zero if success) */
1082 * !! 524 beq $18, $ret_success
1083 * Entry condition: !! 525
1084 * !! 526 ldq $19, 72($sp) /* .. and this a3 */
1085 * a0: trashed, original value saved !! 527 subq $31, $0, $0 /* with error in v0 */
1086 * a1: a1 !! 528 addq $31, 1, $1 /* set a3 for errno return */
1087 * a2: new stack pointer, original i !! 529 stq $0, 0($sp)
1088 * a3: a3 !! 530 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
1089 * depc: a2, original value saved on s !! 531 stq $1, 72($sp) /* a3 for return */
1090 * excsave_1: dispatch table !! 532 br ret_from_sys_call
>> 533
>> 534 /*
>> 535 * Do all cleanup when returning from all interrupts and system calls.
>> 536 *
>> 537 * Arguments:
>> 538 * $8: current.
>> 539 * $17: TI_FLAGS.
>> 540 * $18: The old syscall number, or zero if this is not a return
>> 541 * from a syscall that errored and is possibly restartable.
>> 542 * $19: The old a3 value
1091 */ 543 */
1092 544
1093 ENTRY(fast_syscall_user) !! 545 .align 4
1094 !! 546 .type work_pending, @function
1095 /* Skip syscall. */ !! 547 work_pending:
1096 !! 548 and $17, _TIF_NOTIFY_RESUME | _TIF_SIGPENDING | _TIF_NOTIFY_SIGNAL, $2
1097 rsr a0, epc1 !! 549 bne $2, $work_notifysig
1098 addi a0, a0, 3 <<
1099 wsr a0, epc1 <<
1100 <<
1101 l32i a0, a2, PT_DEPC <<
1102 bgeui a0, VALID_DOUBLE_EXCEPTION_AD <<
1103 <<
1104 rsr a0, depc <<
1105 _beqz a0, fast_syscall_spill_regist <<
1106 _beqi a0, __NR_xtensa, fast_syscall <<
1107 <<
1108 call0 user_exception <<
1109 <<
1110 ENDPROC(fast_syscall_user) <<
1111 <<
1112 ENTRY(fast_syscall_unrecoverable) <<
1113 <<
1114 /* Restore all states. */ <<
1115 <<
1116 l32i a0, a2, PT_AREG0 # res <<
1117 xsr a2, depc # res <<
1118 <<
1119 wsr a0, excsave1 <<
1120 call0 unrecoverable_exception <<
1121 <<
1122 ENDPROC(fast_syscall_unrecoverable) <<
1123 <<
1124 /* <<
1125 * sysxtensa syscall handler <<
1126 * <<
1127 * int sysxtensa (SYS_XTENSA_ATOMIC_SET, <<
1128 * int sysxtensa (SYS_XTENSA_ATOMIC_ADD, <<
1129 * int sysxtensa (SYS_XTENSA_ATOMIC_EXG_ADD, <<
1130 * int sysxtensa (SYS_XTENSA_ATOMIC_CMP_SWP, <<
1131 * a2 a6 <<
1132 * <<
1133 * Entry condition: <<
1134 * <<
1135 * a0: a2 (syscall-nr), original val <<
1136 * a1: a1 <<
1137 * a2: new stack pointer, original i <<
1138 * a3: a3 <<
1139 * a4..a15: unchanged <<
1140 * depc: a2, original value saved on s <<
1141 * excsave_1: dispatch table <<
1142 * <<
1143 * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRES <<
1144 * < VALID_DOUBLE_EXCEPTION_ADDRES <<
1145 * <<
1146 * Note: we don't have to save a2; a2 holds t <<
1147 */ <<
1148 <<
1149 .literal_position <<
1150 <<
1151 #ifdef CONFIG_FAST_SYSCALL_XTENSA <<
1152 <<
1153 ENTRY(fast_syscall_xtensa) <<
1154 <<
1155 s32i a7, a2, PT_AREG7 # we <<
1156 movi a7, 4 # siz <<
1157 access_ok a3, a7, a0, a2, .Leac # a0: <<
1158 <<
1159 _bgeui a6, SYS_XTENSA_COUNT, .Lill <<
1160 _bnei a6, SYS_XTENSA_ATOMIC_CMP_SWP <<
1161 <<
1162 /* Fall through for ATOMIC_CMP_SWP. * <<
1163 <<
1164 .Lswp: /* Atomic compare and swap */ <<
1165 <<
1166 EX(.Leac) l32i a0, a3, 0 # rea <<
1167 bne a0, a4, 1f # sam <<
1168 EX(.Leac) s32i a5, a3, 0 # dif <<
1169 l32i a7, a2, PT_AREG7 # res <<
1170 l32i a0, a2, PT_AREG0 # res <<
1171 movi a2, 1 # and <<
1172 rfe <<
1173 <<
1174 1: l32i a7, a2, PT_AREG7 # res <<
1175 l32i a0, a2, PT_AREG0 # res <<
1176 movi a2, 0 # ret <<
1177 rfe <<
1178 <<
1179 .Lnswp: /* Atomic set, add, and exg_add. */ <<
1180 <<
1181 EX(.Leac) l32i a7, a3, 0 # ori <<
1182 addi a6, a6, -SYS_XTENSA_ATOMIC_SE <<
1183 add a0, a4, a7 # + a <<
1184 moveqz a0, a4, a6 # set <<
1185 addi a6, a6, SYS_XTENSA_ATOMIC_SET <<
1186 EX(.Leac) s32i a0, a3, 0 # wri <<
1187 <<
1188 mov a0, a2 <<
1189 mov a2, a7 <<
1190 l32i a7, a0, PT_AREG7 # res <<
1191 l32i a0, a0, PT_AREG0 # res <<
1192 rfe <<
1193 <<
1194 .Leac: l32i a7, a2, PT_AREG7 # res <<
1195 l32i a0, a2, PT_AREG0 # res <<
1196 movi a2, -EFAULT <<
1197 rfe <<
1198 <<
1199 .Lill: l32i a7, a2, PT_AREG7 # res <<
1200 l32i a0, a2, PT_AREG0 # res <<
1201 movi a2, -EINVAL <<
1202 rfe <<
1203 <<
1204 ENDPROC(fast_syscall_xtensa) <<
1205 <<
1206 #else /* CONFIG_FAST_SYSCALL_XTENSA */ <<
1207 <<
1208 ENTRY(fast_syscall_xtensa) <<
1209 <<
1210 l32i a0, a2, PT_AREG0 # res <<
1211 movi a2, -ENOSYS <<
1212 rfe <<
1213 <<
1214 ENDPROC(fast_syscall_xtensa) <<
1215 <<
1216 #endif /* CONFIG_FAST_SYSCALL_XTENSA */ <<
1217 <<
1218 <<
1219 /* fast_syscall_spill_registers. <<
1220 * <<
1221 * Entry condition: <<
1222 * <<
1223 * a0: trashed, original value saved <<
1224 * a1: a1 <<
1225 * a2: new stack pointer, original i <<
1226 * a3: a3 <<
1227 * depc: a2, original value saved on s <<
1228 * excsave_1: dispatch table <<
1229 * <<
1230 * Note: We assume the stack pointer is EXC_T <<
1231 */ <<
1232 <<
1233 #if defined(CONFIG_FAST_SYSCALL_SPILL_REGISTE <<
1234 defined(USER_SUPPORT_WINDOWED <<
1235 <<
1236 ENTRY(fast_syscall_spill_registers) <<
1237 <<
1238 /* Register a FIXUP handler (pass cur <<
1239 <<
1240 xsr a3, excsave1 <<
1241 movi a0, fast_syscall_spill_regist <<
1242 s32i a0, a3, EXC_TABLE_FIXUP <<
1243 rsr a0, windowbase <<
1244 s32i a0, a3, EXC_TABLE_PARAM <<
1245 xsr a3, excsave1 # res <<
1246 <<
1247 /* Save a3, a4 and SAR on stack. */ <<
1248 <<
1249 rsr a0, sar <<
1250 s32i a3, a2, PT_AREG3 <<
1251 s32i a0, a2, PT_SAR <<
1252 <<
1253 /* The spill routine might clobber a4 <<
1254 <<
1255 s32i a4, a2, PT_AREG4 <<
1256 s32i a7, a2, PT_AREG7 <<
1257 s32i a8, a2, PT_AREG8 <<
1258 s32i a11, a2, PT_AREG11 <<
1259 s32i a12, a2, PT_AREG12 <<
1260 s32i a15, a2, PT_AREG15 <<
1261 550
>> 551 $work_resched:
1262 /* 552 /*
1263 * Rotate ws so that the current wind !! 553 * We can get here only if we returned from syscall without SIGPENDING
1264 * Assume ws = xxxwww1yy (www1 curren !! 554 * or got through work_notifysig already. Either case means no syscall
1265 * Rotate ws right so that a4 = yyxxx !! 555 * restarts for us, so let $18 and $19 burn.
1266 */ !! 556 */
1267 !! 557 jsr $26, schedule
1268 rsr a0, windowbase !! 558 mov 0, $18
1269 rsr a3, windowstart # a3 !! 559 br ret_to_user
1270 ssr a0 # hol !! 560
1271 slli a0, a3, WSBITS !! 561 $work_notifysig:
1272 or a3, a3, a0 # a3 !! 562 mov $sp, $16
1273 srl a3, a3 # a3 !! 563 DO_SWITCH_STACK
1274 !! 564 jsr $26, do_work_pending
1275 /* We are done if there are no more t !! 565 UNDO_SWITCH_STACK
1276 !! 566 br restore_all
1277 extui a3, a3, 1, WSBITS-1 # a3 <<
1278 movi a0, (1 << (WSBITS-1)) <<
1279 _beqz a3, .Lnospill # onl <<
1280 <<
1281 /* We want 1 at the top, so that we r <<
1282 <<
1283 or a3, a3, a0 # 1yy <<
1284 <<
1285 /* Skip empty frames - get 'oldest' W <<
1286 <<
1287 wsr a3, windowstart # sav <<
1288 neg a0, a3 <<
1289 and a3, a0, a3 # fir <<
1290 <<
1291 ffs_ws a0, a3 # a0: <<
1292 movi a3, WSBITS <<
1293 sub a0, a3, a0 # WSB <<
1294 ssr a0 # sav <<
1295 <<
1296 rsr a3, windowbase <<
1297 add a3, a3, a0 <<
1298 wsr a3, windowbase <<
1299 rsync <<
1300 <<
1301 rsr a3, windowstart <<
1302 srl a3, a3 # shi <<
1303 <<
1304 /* WB is now just one frame below the <<
1305 window. WS is shifted so the oldes <<
1306 and WS differ by one 4-register fr <<
1307 <<
1308 /* Save frames. Depending what call w <<
1309 * we have to save 4,8. or 12 registe <<
1310 */ <<
1311 <<
1312 <<
1313 .Lloop: _bbsi.l a3, 1, .Lc4 <<
1314 _bbci.l a3, 2, .Lc12 <<
1315 <<
1316 .Lc8: s32e a4, a13, -16 <<
1317 l32e a4, a5, -12 <<
1318 s32e a8, a4, -32 <<
1319 s32e a5, a13, -12 <<
1320 s32e a6, a13, -8 <<
1321 s32e a7, a13, -4 <<
1322 s32e a9, a4, -28 <<
1323 s32e a10, a4, -24 <<
1324 s32e a11, a4, -20 <<
1325 srli a11, a3, 2 # shi <<
1326 rotw 2 <<
1327 _bnei a3, 1, .Lloop <<
1328 j .Lexit <<
1329 <<
1330 .Lc4: s32e a4, a9, -16 <<
1331 s32e a5, a9, -12 <<
1332 s32e a6, a9, -8 <<
1333 s32e a7, a9, -4 <<
1334 <<
1335 srli a7, a3, 1 <<
1336 rotw 1 <<
1337 _bnei a3, 1, .Lloop <<
1338 j .Lexit <<
1339 <<
1340 .Lc12: _bbci.l a3, 3, .Linvalid_mask # bit <<
1341 <<
1342 /* 12-register frame (call12) */ <<
1343 <<
1344 l32e a0, a5, -12 <<
1345 s32e a8, a0, -48 <<
1346 mov a8, a0 <<
1347 <<
1348 s32e a9, a8, -44 <<
1349 s32e a10, a8, -40 <<
1350 s32e a11, a8, -36 <<
1351 s32e a12, a8, -32 <<
1352 s32e a13, a8, -28 <<
1353 s32e a14, a8, -24 <<
1354 s32e a15, a8, -20 <<
1355 srli a15, a3, 3 <<
1356 <<
1357 /* The stack pointer for a4..a7 is ou <<
1358 * window, grab the stackpointer, and <<
1359 * Alternatively, we could also use t <<
1360 * makes the fixup routine much more <<
1361 * rotw 1 <<
1362 * s32e a0, a13, -16 <<
1363 * ... <<
1364 * rotw 2 <<
1365 */ <<
1366 <<
1367 rotw 1 <<
1368 mov a4, a13 <<
1369 rotw -1 <<
1370 <<
1371 s32e a4, a8, -16 <<
1372 s32e a5, a8, -12 <<
1373 s32e a6, a8, -8 <<
1374 s32e a7, a8, -4 <<
1375 <<
1376 rotw 3 <<
1377 <<
1378 _beqi a3, 1, .Lexit <<
1379 j .Lloop <<
1380 <<
1381 .Lexit: <<
1382 <<
1383 /* Done. Do the final rotation and se <<
1384 <<
1385 rotw 1 <<
1386 rsr a3, windowbase <<
1387 ssl a3 <<
1388 movi a3, 1 <<
1389 sll a3, a3 <<
1390 wsr a3, windowstart <<
1391 .Lnospill: <<
1392 <<
1393 /* Advance PC, restore registers and <<
1394 <<
1395 l32i a3, a2, PT_SAR <<
1396 l32i a0, a2, PT_AREG0 <<
1397 wsr a3, sar <<
1398 l32i a3, a2, PT_AREG3 <<
1399 <<
1400 /* Restore clobbered registers. */ <<
1401 <<
1402 l32i a4, a2, PT_AREG4 <<
1403 l32i a7, a2, PT_AREG7 <<
1404 l32i a8, a2, PT_AREG8 <<
1405 l32i a11, a2, PT_AREG11 <<
1406 l32i a12, a2, PT_AREG12 <<
1407 l32i a15, a2, PT_AREG15 <<
1408 <<
1409 movi a2, 0 <<
1410 rfe <<
1411 <<
1412 .Linvalid_mask: <<
1413 <<
1414 /* We get here because of an unrecove <<
1415 * registers, so set up a dummy frame <<
1416 * Note: We assume EXC_TABLE_KSTK con <<
1417 */ <<
1418 <<
1419 movi a0, 1 <<
1420 movi a1, 0 <<
1421 567
1422 wsr a0, windowstart <<
1423 wsr a1, windowbase <<
1424 rsync <<
1425 <<
1426 movi a0, 0 <<
1427 <<
1428 rsr a3, excsave1 <<
1429 l32i a1, a3, EXC_TABLE_KSTK <<
1430 <<
1431 movi a4, KERNEL_PS_WOE_MASK | LOCK <<
1432 wsr a4, ps <<
1433 rsync <<
1434 <<
1435 movi abi_arg0, SIGSEGV <<
1436 abi_call make_task_dead <<
1437 <<
1438 /* shouldn't return, so panic */ <<
1439 <<
1440 wsr a0, excsave1 <<
1441 call0 unrecoverable_exception <<
1442 1: j 1b <<
1443 <<
1444 <<
1445 ENDPROC(fast_syscall_spill_registers) <<
1446 <<
1447 /* Fixup handler. <<
1448 * <<
1449 * We get here if the spill routine causes an <<
1450 * We basically restore WINDOWBASE and WINDOW <<
1451 * we entered the spill routine and jump to t <<
1452 * <<
1453 * Note that we only need to restore the bits <<
1454 * been spilled yet by the _spill_register ro <<
1455 * rotated windowstart with only those bits s <<
1456 * spilled yet. Because a3 is rotated such th <<
1457 * frame for the current windowbase - 1, we n <<
1458 * value of the current windowbase + 1 and mo <<
1459 * <<
1460 * a0: value of depc, original value in depc <<
1461 * a2: trashed, original value in EXC_TABLE_D <<
1462 * a3: exctable, original value in excsave1 <<
1463 */ <<
1464 <<
1465 ENTRY(fast_syscall_spill_registers_fixup) <<
1466 <<
1467 rsr a2, windowbase # get current <<
1468 xsr a0, depc # restore dep <<
1469 ssl a2 # set shift ( <<
1470 <<
1471 /* We need to make sure the current r <<
1472 * To do this, we simply set the bit <<
1473 * in WS, so that the exception handl <<
1474 * <<
1475 * Note: we use a3 to set the windowb <<
1476 * of it, saving it in the original _ <<
1477 * the exception handler call. <<
1478 */ <<
1479 <<
1480 xsr a3, excsave1 # get spill-m <<
1481 slli a3, a3, 1 # shift left <<
1482 addi a3, a3, 1 # set the bit <<
1483 <<
1484 slli a2, a3, 32-WSBITS <<
1485 src a2, a3, a2 # a2 = xxwww1 <<
1486 wsr a2, windowstart # set correct <<
1487 <<
1488 srli a3, a3, 1 <<
1489 rsr a2, excsave1 <<
1490 l32i a2, a2, EXC_TABLE_DOUBLE_SAVE <<
1491 xsr a2, excsave1 <<
1492 s32i a3, a2, EXC_TABLE_DOUBLE_SAVE <<
1493 l32i a3, a2, EXC_TABLE_PARAM # ori <<
1494 xsr a2, excsave1 <<
1495 <<
1496 /* Return to the original (user task) <<
1497 * We leave the following frame behin <<
1498 * a0, a1, a2 same <<
1499 * a3: trashed (saved in EXC <<
1500 * depc: depc (we have to retu <<
1501 * excsave_1: exctable <<
1502 */ <<
1503 <<
1504 wsr a3, windowbase <<
1505 rsync <<
1506 <<
1507 /* We are now in the original frame w <<
1508 * a0: return address <<
1509 * a1: used, stack pointer <<
1510 * a2: kernel stack pointer <<
1511 * a3: available <<
1512 * depc: exception address <<
1513 * excsave: exctable <<
1514 * Note: This frame might be the same <<
1515 */ <<
1516 <<
1517 /* Setup stack pointer. */ <<
1518 <<
1519 addi a2, a2, -PT_USER_SIZE <<
1520 s32i a0, a2, PT_AREG0 <<
1521 <<
1522 /* Make sure we return to this fixup <<
1523 <<
1524 movi a3, fast_syscall_spill_regist <<
1525 s32i a3, a2, PT_DEPC # set <<
1526 <<
1527 /* Jump to the exception handler. */ <<
1528 <<
1529 rsr a3, excsave1 <<
1530 rsr a0, exccause <<
1531 addx4 a0, a0, a3 <<
1532 l32i a0, a0, EXC_TABLE_FAST_USER <<
1533 l32i a3, a3, EXC_TABLE_DOUBLE_SAVE <<
1534 jx a0 <<
1535 <<
1536 ENDPROC(fast_syscall_spill_registers_fixup) <<
1537 <<
1538 ENTRY(fast_syscall_spill_registers_fixup_retu <<
1539 <<
1540 /* When we return here, all registers <<
1541 <<
1542 wsr a2, depc # exc <<
1543 <<
1544 /* Restore fixup handler. */ <<
1545 <<
1546 rsr a2, excsave1 <<
1547 s32i a3, a2, EXC_TABLE_DOUBLE_SAVE <<
1548 movi a3, fast_syscall_spill_regist <<
1549 s32i a3, a2, EXC_TABLE_FIXUP <<
1550 rsr a3, windowbase <<
1551 s32i a3, a2, EXC_TABLE_PARAM <<
1552 l32i a2, a2, EXC_TABLE_KSTK <<
1553 <<
1554 /* Load WB at the time the exception <<
1555 <<
1556 rsr a3, sar # WB <<
1557 neg a3, a3 <<
1558 wsr a3, windowbase <<
1559 rsync <<
1560 <<
1561 rsr a3, excsave1 <<
1562 l32i a3, a3, EXC_TABLE_DOUBLE_SAVE <<
1563 <<
1564 rfde <<
1565 <<
1566 ENDPROC(fast_syscall_spill_registers_fixup_re <<
1567 <<
1568 #else /* CONFIG_FAST_SYSCALL_SPILL_REGISTERS <<
1569 <<
1570 ENTRY(fast_syscall_spill_registers) <<
1571 <<
1572 l32i a0, a2, PT_AREG0 # res <<
1573 movi a2, -ENOSYS <<
1574 rfe <<
1575 <<
1576 ENDPROC(fast_syscall_spill_registers) <<
1577 <<
1578 #endif /* CONFIG_FAST_SYSCALL_SPILL_REGISTERS <<
1579 <<
1580 #ifdef CONFIG_MMU <<
1581 /* 568 /*
1582 * We should never get here. Bail out! !! 569 * PTRACE syscall handler
1583 */ <<
1584 <<
1585 ENTRY(fast_second_level_miss_double_kernel) <<
1586 <<
1587 1: <<
1588 call0 unrecoverable_exception <<
1589 1: j 1b <<
1590 <<
1591 ENDPROC(fast_second_level_miss_double_kernel) <<
1592 <<
1593 /* First-level entry handler for user, kernel <<
1594 * TLB miss exceptions. Note that for now, u <<
1595 * exceptions share the same entry point and <<
1596 * <<
1597 * An old, less-efficient C version of this f <<
1598 * We include it below, interleaved as commen <<
1599 * <<
1600 * Entry condition: <<
1601 * <<
1602 * a0: trashed, original value saved <<
1603 * a1: a1 <<
1604 * a2: new stack pointer, original i <<
1605 * a3: a3 <<
1606 * depc: a2, original value saved on s <<
1607 * excsave_1: dispatch table <<
1608 * <<
1609 * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRES <<
1610 * < VALID_DOUBLE_EXCEPTION_ADDRES <<
1611 */ 570 */
1612 571
1613 ENTRY(fast_second_level_miss) !! 572 .align 4
1614 !! 573 .type strace, @function
1615 /* Save a1 and a3. Note: we don't exp !! 574 strace:
1616 !! 575 /* set up signal stack, call syscall_trace */
1617 s32i a1, a2, PT_AREG1 !! 576 // NB: if anyone adds preemption, this block will need to be protected
1618 s32i a3, a2, PT_AREG3 !! 577 ldl $1, TI_STATUS($8)
1619 !! 578 and $1, TS_SAVED_FP, $3
1620 /* We need to map the page of PTEs fo !! 579 or $1, TS_SAVED_FP, $2
1621 * the pointer to that page. Also, i !! 580 bne $3, 1f
1622 * to be NULL while tsk->active_mm is !! 581 stl $2, TI_STATUS($8)
1623 * a vmalloc address. In that rare c !! 582 bsr $26, __save_fpu
1624 * active_mm instead to avoid a fault !! 583 1:
1625 * !! 584 DO_SWITCH_STACK
1626 * http://mail.nl.linux.org/linux-mm/ !! 585 jsr $26, syscall_trace_enter /* returns the syscall number */
1627 * (or search Internet on "mm vs. a !! 586 UNDO_SWITCH_STACK
1628 * !! 587
1629 * if (!mm) !! 588 /* get the arguments back.. */
1630 * mm = tsk->active_mm; !! 589 ldq $16, SP_OFF+24($sp)
1631 * pgd = pgd_offset (mm, regs->e !! 590 ldq $17, SP_OFF+32($sp)
1632 * pmd = pmd_offset (pgd, regs-> !! 591 ldq $18, SP_OFF+40($sp)
1633 * pmdval = *pmd; !! 592 ldq $19, 72($sp)
1634 */ !! 593 ldq $20, 80($sp)
1635 !! 594 ldq $21, 88($sp)
1636 GET_CURRENT(a1,a2) !! 595
1637 l32i a0, a1, TASK_MM # tsk !! 596 /* get the system call pointer.. */
1638 beqz a0, .Lfast_second_level_miss_ !! 597 lda $1, NR_syscalls($31)
1639 !! 598 lda $2, sys_call_table
1640 .Lfast_second_level_miss_continue: !! 599 lda $27, sys_ni_syscall
1641 rsr a3, excvaddr # fau !! 600 cmpult $0, $1, $1
1642 _PGD_OFFSET(a0, a3, a1) !! 601 s8addq $0, $2, $2
1643 l32i a0, a0, 0 # rea !! 602 beq $1, 1f
1644 beqz a0, .Lfast_second_level_miss_ !! 603 ldq $27, 0($2)
1645 !! 604 1: jsr $26, ($27), sys_gettimeofday
1646 /* Read ptevaddr and convert to top o !! 605 ret_from_straced:
1647 * !! 606 ldgp $gp, 0($26)
1648 * vpnval = read_ptevaddr_regist !! 607
1649 * vpnval += DTLB_WAY_PGTABLE; !! 608 /* check return.. */
1650 * pteval = mk_pte (virt_to_page !! 609 blt $0, $strace_error /* the call failed */
1651 * write_dtlb_entry (pteval, vpn !! 610 $strace_success:
1652 * !! 611 stq $31, 72($sp) /* a3=0 => no error */
1653 * The messy computation for 'pteval' !! 612 stq $0, 0($sp) /* save return value */
1654 * into the following: !! 613
1655 * !! 614 DO_SWITCH_STACK
1656 * pteval = ((pmdval - PAGE_OFFSET + !! 615 jsr $26, syscall_trace_leave
1657 * | PAGE_DIRECTORY !! 616 UNDO_SWITCH_STACK
1658 */ !! 617 br $31, ret_from_sys_call
1659 !! 618
1660 movi a1, (PHYS_OFFSET - PAGE_OFFSE !! 619 .align 3
1661 add a0, a0, a1 # pmd !! 620 $strace_error:
1662 extui a1, a0, 0, PAGE_SHIFT # ... !! 621 ldq $18, 0($sp) /* old syscall nr (zero if success) */
1663 xor a0, a0, a1 !! 622 beq $18, $strace_success
1664 !! 623 ldq $19, 72($sp) /* .. and this a3 */
1665 movi a1, _PAGE_DIRECTORY !! 624
1666 or a0, a0, a1 # ... !! 625 subq $31, $0, $0 /* with error in v0 */
1667 !! 626 addq $31, 1, $1 /* set a3 for errno return */
1668 /* !! 627 stq $0, 0($sp)
1669 * We utilize all three wired-ways (7 !! 628 stq $1, 72($sp) /* a3 for return */
1670 * Memory regions are mapped to the D !! 629
1671 * This allows to map the three most !! 630 DO_SWITCH_STACK
1672 * DTLBs: !! 631 mov $18, $9 /* save old syscall number */
1673 * 0,1 -> way 7 program (0040 !! 632 mov $19, $10 /* save old a3 */
1674 * 2 -> way 8 shared libari !! 633 jsr $26, syscall_trace_leave
1675 * 3 -> way 0 stack (3000.0 !! 634 mov $9, $18
1676 */ !! 635 mov $10, $19
1677 !! 636 UNDO_SWITCH_STACK
1678 extui a3, a3, 28, 2 # add !! 637
1679 rsr a1, ptevaddr !! 638 mov $31, $26 /* tell "ret_from_sys_call" we can restart */
1680 addx2 a3, a3, a3 # -> !! 639 br ret_from_sys_call
1681 srli a1, a1, PAGE_SHIFT !! 640 CFI_END_OSF_FRAME entSys
1682 extui a3, a3, 2, 2 # -> !! 641
1683 slli a1, a1, PAGE_SHIFT # pte <<
1684 addi a3, a3, DTLB_WAY_PGD <<
1685 add a1, a1, a3 # ... <<
1686 <<
1687 .Lfast_second_level_miss_wdtlb: <<
1688 wdtlb a0, a1 <<
1689 dsync <<
1690 <<
1691 /* Exit critical section. */ <<
1692 .Lfast_second_level_miss_skip_wdtlb: <<
1693 rsr a3, excsave1 <<
1694 movi a0, 0 <<
1695 s32i a0, a3, EXC_TABLE_FIXUP <<
1696 <<
1697 /* Restore the working registers, and <<
1698 <<
1699 l32i a0, a2, PT_AREG0 <<
1700 l32i a1, a2, PT_AREG1 <<
1701 l32i a3, a2, PT_AREG3 <<
1702 l32i a2, a2, PT_DEPC <<
1703 <<
1704 bgeui a2, VALID_DOUBLE_EXCEPTION_AD <<
1705 <<
1706 /* Restore excsave1 and return. */ <<
1707 <<
1708 rsr a2, depc <<
1709 rfe <<
1710 <<
1711 /* Return from double exception. */ <<
1712 <<
1713 1: xsr a2, depc <<
1714 esync <<
1715 rfde <<
1716 <<
1717 .Lfast_second_level_miss_no_mm: <<
1718 l32i a0, a1, TASK_ACTIVE_MM # unl <<
1719 bnez a0, .Lfast_second_level_miss_ <<
1720 <<
1721 /* Even more unlikely case active_mm <<
1722 * We can get here with NMI in the mi <<
1723 * touches vmalloc area. <<
1724 */ <<
1725 movi a0, init_mm <<
1726 j .Lfast_second_level_miss_cont <<
1727 <<
1728 .Lfast_second_level_miss_no_pmd: <<
1729 #if (DCACHE_WAY_SIZE > PAGE_SIZE) <<
1730 <<
1731 /* Special case for cache aliasing. <<
1732 * We (should) only get here if a cle <<
1733 * or the aliased cache flush functio <<
1734 * by another task. Re-establish temp <<
1735 * TLBTEMP_BASE areas. <<
1736 */ <<
1737 <<
1738 /* We shouldn't be in a double except <<
1739 <<
1740 l32i a0, a2, PT_DEPC <<
1741 bgeui a0, VALID_DOUBLE_EXCEPTION_AD <<
1742 <<
1743 /* Make sure the exception originated <<
1744 <<
1745 movi a0, __tlbtemp_mapping_start <<
1746 rsr a3, epc1 <<
1747 bltu a3, a0, .Lfast_second_level_m <<
1748 movi a0, __tlbtemp_mapping_end <<
1749 bgeu a3, a0, .Lfast_second_level_m <<
1750 <<
1751 /* Check if excvaddr was in one of th <<
1752 <<
1753 movi a3, TLBTEMP_BASE_1 <<
1754 rsr a0, excvaddr <<
1755 bltu a0, a3, .Lfast_second_level_m <<
1756 <<
1757 addi a1, a0, -TLBTEMP_SIZE <<
1758 bgeu a1, a3, .Lfast_second_level_m <<
1759 <<
1760 /* Check if we have to restore an ITL <<
1761 <<
1762 movi a1, __tlbtemp_mapping_itlb <<
1763 rsr a3, epc1 <<
1764 sub a3, a3, a1 <<
1765 <<
1766 /* Calculate VPN */ <<
1767 <<
1768 movi a1, PAGE_MASK <<
1769 and a1, a1, a0 <<
1770 <<
1771 /* Jump for ITLB entry */ <<
1772 <<
1773 bgez a3, 1f <<
1774 <<
1775 /* We can use up to two TLBTEMP areas <<
1776 <<
1777 extui a3, a0, PAGE_SHIFT + DCACHE_A <<
1778 add a1, a3, a1 <<
1779 <<
1780 /* PPN is in a6 for the first TLBTEMP <<
1781 <<
1782 mov a0, a6 <<
1783 movnez a0, a7, a3 <<
1784 j .Lfast_second_level_miss_wdtl <<
1785 <<
1786 /* ITLB entry. We only use dst in a6. <<
1787 <<
1788 1: witlb a6, a1 <<
1789 isync <<
1790 j .Lfast_second_level_miss_skip <<
1791 <<
1792 <<
1793 #endif // DCACHE_WAY_SIZE > PAGE_SIZE <<
1794 <<
1795 /* Invalid PGD, default exception han <<
1796 .Lfast_second_level_miss_slow: <<
1797 <<
1798 rsr a1, depc <<
1799 s32i a1, a2, PT_AREG2 <<
1800 mov a1, a2 <<
1801 <<
1802 rsr a2, ps <<
1803 bbsi.l a2, PS_UM_BIT, 1f <<
1804 call0 _kernel_exception <<
1805 1: call0 _user_exception <<
1806 <<
1807 ENDPROC(fast_second_level_miss) <<
1808 <<
1809 /* 642 /*
1810 * StoreProhibitedException !! 643 * Save and restore the switch stack -- aka the balance of the user context.
1811 * <<
1812 * Update the pte and invalidate the itlb map <<
1813 * <<
1814 * Entry condition: <<
1815 * <<
1816 * a0: trashed, original value saved <<
1817 * a1: a1 <<
1818 * a2: new stack pointer, original i <<
1819 * a3: a3 <<
1820 * depc: a2, original value saved on s <<
1821 * excsave_1: dispatch table <<
1822 * <<
1823 * PT_DEPC >= VALID_DOUBLE_EXCEPTION_ADDRES <<
1824 * < VALID_DOUBLE_EXCEPTION_ADDRES <<
1825 */ 644 */
1826 645
1827 ENTRY(fast_store_prohibited) !! 646 .align 4
1828 !! 647 .type do_switch_stack, @function
1829 /* Save a1 and a3. */ !! 648 .cfi_startproc simple
1830 !! 649 .cfi_return_column 64
1831 s32i a1, a2, PT_AREG1 !! 650 .cfi_def_cfa $sp, 0
1832 s32i a3, a2, PT_AREG3 !! 651 .cfi_register 64, $1
1833 !! 652 do_switch_stack:
1834 GET_CURRENT(a1,a2) !! 653 lda $sp, -SWITCH_STACK_SIZE($sp)
1835 l32i a0, a1, TASK_MM # tsk !! 654 .cfi_adjust_cfa_offset SWITCH_STACK_SIZE
1836 beqz a0, .Lfast_store_no_mm !! 655 stq $9, 0($sp)
1837 !! 656 stq $10, 8($sp)
1838 .Lfast_store_continue: !! 657 stq $11, 16($sp)
1839 rsr a1, excvaddr # fau !! 658 stq $12, 24($sp)
1840 _PGD_OFFSET(a0, a1, a3) !! 659 stq $13, 32($sp)
1841 l32i a0, a0, 0 !! 660 stq $14, 40($sp)
1842 beqz a0, .Lfast_store_slow !! 661 stq $15, 48($sp)
1843 !! 662 stq $26, 56($sp)
1844 /* !! 663 ret $31, ($1), 1
1845 * Note that we test _PAGE_WRITABLE_B !! 664 .cfi_endproc
1846 * and is not PAGE_NONE. See pgtable. !! 665 .size do_switch_stack, .-do_switch_stack
1847 */ <<
1848 <<
1849 _PTE_OFFSET(a0, a1, a3) <<
1850 l32i a3, a0, 0 # rea <<
1851 movi a1, _PAGE_CA_INVALID <<
1852 ball a3, a1, .Lfast_store_slow <<
1853 bbci.l a3, _PAGE_WRITABLE_BIT, .Lfas <<
1854 <<
1855 movi a1, _PAGE_ACCESSED | _PAGE_DI <<
1856 or a3, a3, a1 <<
1857 rsr a1, excvaddr <<
1858 s32i a3, a0, 0 <<
1859 <<
1860 /* We need to flush the cache if we h <<
1861 #if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DC <<
1862 dhwb a0, 0 <<
1863 #endif <<
1864 pdtlb a0, a1 <<
1865 wdtlb a3, a0 <<
1866 <<
1867 /* Exit critical section. */ <<
1868 666
1869 movi a0, 0 !! 667 .align 4
1870 rsr a3, excsave1 !! 668 .type undo_switch_stack, @function
1871 s32i a0, a3, EXC_TABLE_FIXUP !! 669 .cfi_startproc simple
1872 !! 670 .cfi_def_cfa $sp, 0
1873 /* Restore the working registers, and !! 671 .cfi_register 64, $1
1874 !! 672 undo_switch_stack:
1875 l32i a3, a2, PT_AREG3 !! 673 ldq $9, 0($sp)
1876 l32i a1, a2, PT_AREG1 !! 674 ldq $10, 8($sp)
1877 l32i a0, a2, PT_AREG0 !! 675 ldq $11, 16($sp)
1878 l32i a2, a2, PT_DEPC !! 676 ldq $12, 24($sp)
1879 !! 677 ldq $13, 32($sp)
1880 bgeui a2, VALID_DOUBLE_EXCEPTION_AD !! 678 ldq $14, 40($sp)
1881 rsr a2, depc !! 679 ldq $15, 48($sp)
1882 rfe !! 680 ldq $26, 56($sp)
1883 !! 681 lda $sp, SWITCH_STACK_SIZE($sp)
1884 /* Double exception. Restore FIXUP ha !! 682 ret $31, ($1), 1
1885 !! 683 .cfi_endproc
1886 1: xsr a2, depc !! 684 .size undo_switch_stack, .-undo_switch_stack
1887 esync <<
1888 rfde <<
1889 <<
1890 .Lfast_store_no_mm: <<
1891 l32i a0, a1, TASK_ACTIVE_MM # unl <<
1892 j .Lfast_store_continue <<
1893 <<
1894 /* If there was a problem, handle fau <<
1895 .Lfast_store_slow: <<
1896 rsr a1, excvaddr <<
1897 pdtlb a0, a1 <<
1898 bbci.l a0, DTLB_HIT_BIT, 1f <<
1899 idtlb a0 <<
1900 1: <<
1901 rsr a3, depc # still holds <<
1902 s32i a3, a2, PT_AREG2 <<
1903 mov a1, a2 <<
1904 <<
1905 rsr a2, ps <<
1906 bbsi.l a2, PS_UM_BIT, 1f <<
1907 call0 _kernel_exception <<
1908 1: call0 _user_exception <<
1909 685
1910 ENDPROC(fast_store_prohibited) !! 686 #define FR(n) n * 8 + TI_FP($8)
>> 687 .align 4
>> 688 .globl __save_fpu
>> 689 .type __save_fpu, @function
>> 690 __save_fpu:
>> 691 #define V(n) stt $f##n, FR(n)
>> 692 V( 0); V( 1); V( 2); V( 3)
>> 693 V( 4); V( 5); V( 6); V( 7)
>> 694 V( 8); V( 9); V(10); V(11)
>> 695 V(12); V(13); V(14); V(15)
>> 696 V(16); V(17); V(18); V(19)
>> 697 V(20); V(21); V(22); V(23)
>> 698 V(24); V(25); V(26); V(27)
>> 699 mf_fpcr $f0 # get fpcr
>> 700 V(28); V(29); V(30)
>> 701 stt $f0, FR(31) # save fpcr in slot of $f31
>> 702 ldt $f0, FR(0) # don't let "__save_fpu" change fp state.
>> 703 ret
>> 704 #undef V
>> 705 .size __save_fpu, .-__save_fpu
1911 706
1912 #endif /* CONFIG_MMU */ !! 707 .align 4
>> 708 restore_fpu:
>> 709 and $3, TS_RESTORE_FP, $3
>> 710 bic $2, TS_SAVED_FP | TS_RESTORE_FP, $2
>> 711 beq $3, 1f
>> 712 #define V(n) ldt $f##n, FR(n)
>> 713 ldt $f30, FR(31) # get saved fpcr
>> 714 V( 0); V( 1); V( 2); V( 3)
>> 715 mt_fpcr $f30 # install saved fpcr
>> 716 V( 4); V( 5); V( 6); V( 7)
>> 717 V( 8); V( 9); V(10); V(11)
>> 718 V(12); V(13); V(14); V(15)
>> 719 V(16); V(17); V(18); V(19)
>> 720 V(20); V(21); V(22); V(23)
>> 721 V(24); V(25); V(26); V(27)
>> 722 V(28); V(29); V(30)
>> 723 1: stl $2, TI_STATUS($8)
>> 724 br restore_other
>> 725 #undef V
1913 726
1914 .text !! 727
1915 /* 728 /*
1916 * System Calls. !! 729 * The meat of the context switch code.
1917 * <<
1918 * void system_call (struct pt_regs* regs, in <<
1919 * a2 <<
1920 */ 730 */
1921 .literal_position !! 731 .align 4
1922 !! 732 .globl alpha_switch_to
1923 ENTRY(system_call) !! 733 .type alpha_switch_to, @function
1924 !! 734 .cfi_startproc
1925 #if defined(__XTENSA_WINDOWED_ABI__) !! 735 alpha_switch_to:
1926 abi_entry_default !! 736 DO_SWITCH_STACK
1927 #elif defined(__XTENSA_CALL0_ABI__) !! 737 ldl $1, TI_STATUS($8)
1928 abi_entry(12) !! 738 and $1, TS_RESTORE_FP, $3
1929 !! 739 bne $3, 1f
1930 s32i a0, sp, 0 !! 740 or $1, TS_RESTORE_FP | TS_SAVED_FP, $2
1931 s32i abi_saved0, sp, 4 !! 741 and $1, TS_SAVED_FP, $3
1932 s32i abi_saved1, sp, 8 !! 742 stl $2, TI_STATUS($8)
1933 mov abi_saved0, a2 !! 743 bne $3, 1f
1934 #else !! 744 bsr $26, __save_fpu
1935 #error Unsupported Xtensa ABI !! 745 1:
1936 #endif !! 746 call_pal PAL_swpctx
1937 !! 747 lda $8, 0x3fff
1938 /* regs->syscall = regs->areg[2] */ !! 748 UNDO_SWITCH_STACK
1939 !! 749 bic $sp, $8, $8
1940 l32i a7, abi_saved0, PT_AREG2 !! 750 mov $17, $0
1941 s32i a7, abi_saved0, PT_SYSCALL !! 751 ret
1942 !! 752 .cfi_endproc
1943 GET_THREAD_INFO(a4, a1) !! 753 .size alpha_switch_to, .-alpha_switch_to
1944 l32i abi_saved1, a4, TI_FLAGS <<
1945 movi a4, _TIF_WORK_MASK <<
1946 and abi_saved1, abi_saved1, a4 <<
1947 beqz abi_saved1, 1f <<
1948 <<
1949 mov abi_arg0, abi_saved0 <<
1950 abi_call do_syscall_trace_ente <<
1951 beqz abi_rv, .Lsyscall_exit <<
1952 l32i a7, abi_saved0, PT_SYSCALL <<
1953 <<
1954 1: <<
1955 /* syscall = sys_call_table[syscall_n <<
1956 <<
1957 movi a4, sys_call_table <<
1958 movi a5, __NR_syscalls <<
1959 movi abi_rv, -ENOSYS <<
1960 bgeu a7, a5, 1f <<
1961 <<
1962 addx4 a4, a7, a4 <<
1963 l32i abi_tmp0, a4, 0 <<
1964 <<
1965 /* Load args: arg0 - arg5 are passed <<
1966 <<
1967 l32i abi_arg0, abi_saved0, PT_AREG <<
1968 l32i abi_arg1, abi_saved0, PT_AREG <<
1969 l32i abi_arg2, abi_saved0, PT_AREG <<
1970 l32i abi_arg3, abi_saved0, PT_AREG <<
1971 l32i abi_arg4, abi_saved0, PT_AREG <<
1972 l32i abi_arg5, abi_saved0, PT_AREG <<
1973 <<
1974 abi_callx abi_tmp0 <<
1975 <<
1976 1: /* regs->areg[2] = return_value */ <<
1977 <<
1978 s32i abi_rv, abi_saved0, PT_AREG2 <<
1979 bnez abi_saved1, 1f <<
1980 .Lsyscall_exit: <<
1981 #if defined(__XTENSA_WINDOWED_ABI__) <<
1982 abi_ret_default <<
1983 #elif defined(__XTENSA_CALL0_ABI__) <<
1984 l32i a0, sp, 0 <<
1985 l32i abi_saved0, sp, 4 <<
1986 l32i abi_saved1, sp, 8 <<
1987 abi_ret(12) <<
1988 #else <<
1989 #error Unsupported Xtensa ABI <<
1990 #endif <<
1991 <<
1992 1: <<
1993 mov abi_arg0, abi_saved0 <<
1994 abi_call do_syscall_trace_leav <<
1995 j .Lsyscall_exit <<
1996 <<
1997 ENDPROC(system_call) <<
1998 754
1999 /* 755 /*
2000 * Spill live registers on the kernel stack m !! 756 * New processes begin life here.
2001 * <<
2002 * Entry condition: ps.woe is set, ps.excm is <<
2003 * Exit condition: windowstart has single bit <<
2004 * May clobber: a12, a13 <<
2005 */ 757 */
2006 .macro spill_registers_kernel <<
2007 758
2008 #if XCHAL_NUM_AREGS > 16 !! 759 .globl ret_from_fork
2009 call12 1f <<
2010 _j 2f <<
2011 retw <<
2012 .align 4 760 .align 4
2013 1: !! 761 .ent ret_from_fork
2014 _entry a1, 48 !! 762 ret_from_fork:
2015 addi a12, a0, 3 !! 763 lda $26, ret_to_user
2016 #if XCHAL_NUM_AREGS > 32 !! 764 mov $17, $16
2017 .rept (XCHAL_NUM_AREGS - 32) / 12 !! 765 jmp $31, schedule_tail
2018 _entry a1, 48 !! 766 .end ret_from_fork
2019 mov a12, a0 <<
2020 .endr <<
2021 #endif <<
2022 _entry a1, 16 <<
2023 #if XCHAL_NUM_AREGS % 12 == 0 <<
2024 mov a8, a8 <<
2025 #elif XCHAL_NUM_AREGS % 12 == 4 <<
2026 mov a12, a12 <<
2027 #elif XCHAL_NUM_AREGS % 12 == 8 <<
2028 mov a4, a4 <<
2029 #endif <<
2030 retw <<
2031 2: <<
2032 #else <<
2033 mov a12, a12 <<
2034 #endif <<
2035 .endm <<
2036 767
2037 /* 768 /*
2038 * Task switch. !! 769 * ... and new kernel threads - here
2039 * <<
2040 * struct task* _switch_to (struct task* pre <<
2041 * a2 a2 <<
2042 */ 770 */
>> 771 .align 4
>> 772 .globl ret_from_kernel_thread
>> 773 .ent ret_from_kernel_thread
>> 774 ret_from_kernel_thread:
>> 775 mov $17, $16
>> 776 jsr $26, schedule_tail
>> 777 mov $9, $27
>> 778 mov $10, $16
>> 779 jsr $26, ($9)
>> 780 br $31, ret_to_user
>> 781 .end ret_from_kernel_thread
2043 782
2044 ENTRY(_switch_to) !! 783
2045 <<
2046 #if defined(__XTENSA_WINDOWED_ABI__) <<
2047 abi_entry(XTENSA_SPILL_STACK_RESERVE) <<
2048 #elif defined(__XTENSA_CALL0_ABI__) <<
2049 abi_entry(16) <<
2050 <<
2051 s32i a12, sp, 0 <<
2052 s32i a13, sp, 4 <<
2053 s32i a14, sp, 8 <<
2054 s32i a15, sp, 12 <<
2055 #else <<
2056 #error Unsupported Xtensa ABI <<
2057 #endif <<
2058 mov a11, a3 # and <<
2059 <<
2060 l32i a4, a2, TASK_THREAD_INFO <<
2061 l32i a5, a3, TASK_THREAD_INFO <<
2062 <<
2063 save_xtregs_user a4 a6 a8 a9 a12 a13 <<
2064 <<
2065 #if THREAD_RA > 1020 || THREAD_SP > 1020 <<
2066 addi a10, a2, TASK_THREAD <<
2067 s32i a0, a10, THREAD_RA - TASK_THR <<
2068 s32i a1, a10, THREAD_SP - TASK_THR <<
2069 #else <<
2070 s32i a0, a2, THREAD_RA # sav <<
2071 s32i a1, a2, THREAD_SP # sav <<
2072 #endif <<
2073 <<
2074 #if defined(CONFIG_STACKPROTECTOR) && !define <<
2075 movi a6, __stack_chk_guard <<
2076 l32i a8, a3, TASK_STACK_CANARY <<
2077 s32i a8, a6, 0 <<
2078 #endif <<
2079 <<
2080 /* Disable ints while we manipulate t <<
2081 <<
2082 irq_save a14, a3 <<
2083 rsync <<
2084 <<
2085 /* Switch CPENABLE */ <<
2086 <<
2087 #if (XTENSA_HAVE_COPROCESSORS || XTENSA_HAVE_ <<
2088 l32i a3, a5, THREAD_CPENABLE <<
2089 #ifdef CONFIG_SMP <<
2090 beqz a3, 1f <<
2091 memw # pairs with <<
2092 l32i a6, a5, THREAD_CP_OWNER_CPU <<
2093 l32i a7, a5, THREAD_CPU <<
2094 beq a6, a7, 1f # load 0 into <<
2095 movi a3, 0 <<
2096 1: <<
2097 #endif <<
2098 wsr a3, cpenable <<
2099 #endif <<
2100 <<
2101 #if XCHAL_HAVE_EXCLUSIVE <<
2102 l32i a3, a5, THREAD_ATOMCTL8 <<
2103 getex a3 <<
2104 s32i a3, a4, THREAD_ATOMCTL8 <<
2105 #endif <<
2106 <<
2107 /* Flush register file. */ <<
2108 <<
2109 #if defined(__XTENSA_WINDOWED_ABI__) <<
2110 spill_registers_kernel <<
2111 #endif <<
2112 <<
2113 /* Set kernel stack (and leave critic <<
2114 * Note: It's save to set it here. Th <<
2115 * because the kernel stack wil <<
2116 * we return from kernel space. <<
2117 */ <<
2118 <<
2119 rsr a3, excsave1 # exc <<
2120 addi a7, a5, PT_REGS_OFFSET <<
2121 s32i a7, a3, EXC_TABLE_KSTK <<
2122 <<
2123 /* restore context of the task 'next' <<
2124 <<
2125 l32i a0, a11, THREAD_RA # res <<
2126 l32i a1, a11, THREAD_SP # res <<
2127 <<
2128 load_xtregs_user a5 a6 a8 a9 a12 a13 <<
2129 <<
2130 wsr a14, ps <<
2131 rsync <<
2132 <<
2133 #if defined(__XTENSA_WINDOWED_ABI__) <<
2134 abi_ret(XTENSA_SPILL_STACK_RESERVE) <<
2135 #elif defined(__XTENSA_CALL0_ABI__) <<
2136 l32i a12, sp, 0 <<
2137 l32i a13, sp, 4 <<
2138 l32i a14, sp, 8 <<
2139 l32i a15, sp, 12 <<
2140 abi_ret(16) <<
2141 #else <<
2142 #error Unsupported Xtensa ABI <<
2143 #endif <<
2144 <<
2145 ENDPROC(_switch_to) <<
2146 <<
2147 ENTRY(ret_from_fork) <<
2148 <<
2149 /* void schedule_tail (struct task_st <<
2150 * Note: prev is still in abi_arg0 (r <<
2151 */ <<
2152 abi_call schedule_tail <<
2153 <<
2154 mov abi_arg0, a1 <<
2155 abi_call do_syscall_trace_leav <<
2156 j common_exception_retu <<
2157 <<
2158 ENDPROC(ret_from_fork) <<
2159 <<
2160 /* 784 /*
2161 * Kernel thread creation helper !! 785 * Special system calls. Most of these are special in that they either
2162 * On entry, set up by copy_thread: abi_saved !! 786 * have to play switch_stack games.
2163 * abi_saved1 = thread_fn arg. Left from _swi <<
2164 */ 787 */
2165 ENTRY(ret_from_kernel_thread) <<
2166 <<
2167 abi_call schedule_tail <<
2168 mov abi_arg0, abi_saved1 <<
2169 abi_callx abi_saved0 <<
2170 j common_exception_retu <<
2171 788
2172 ENDPROC(ret_from_kernel_thread) !! 789 .macro fork_like name
2173 <<
2174 #ifdef CONFIG_HIBERNATION <<
2175 <<
2176 .section .bss, "aw" <<
2177 .align 4 790 .align 4
2178 .Lsaved_regs: !! 791 .globl alpha_\name
2179 #if defined(__XTENSA_WINDOWED_ABI__) !! 792 .ent alpha_\name
2180 .fill 2, 4 !! 793 alpha_\name:
2181 #elif defined(__XTENSA_CALL0_ABI__) !! 794 .prologue 0
2182 .fill 6, 4 !! 795 bsr $1, do_switch_stack
2183 #else !! 796 // NB: if anyone adds preemption, this block will need to be protected
2184 #error Unsupported Xtensa ABI !! 797 ldl $1, TI_STATUS($8)
2185 #endif !! 798 and $1, TS_SAVED_FP, $3
2186 .align XCHAL_NCP_SA_ALIGN !! 799 or $1, TS_SAVED_FP, $2
2187 .Lsaved_user_regs: !! 800 bne $3, 1f
2188 .fill XTREGS_USER_SIZE, 1 !! 801 stl $2, TI_STATUS($8)
2189 !! 802 bsr $26, __save_fpu
2190 .previous !! 803 1:
2191 !! 804 jsr $26, sys_\name
2192 ENTRY(swsusp_arch_suspend) !! 805 ldq $26, 56($sp)
2193 !! 806 lda $sp, SWITCH_STACK_SIZE($sp)
2194 abi_entry_default !! 807 ret
2195 !! 808 .end alpha_\name
2196 movi a2, .Lsaved_regs !! 809 .endm
2197 movi a3, .Lsaved_user_regs !! 810
2198 s32i a0, a2, 0 !! 811 fork_like fork
2199 s32i a1, a2, 4 !! 812 fork_like vfork
2200 save_xtregs_user a3 a4 a5 a6 a7 a8 0 !! 813 fork_like clone
2201 #if defined(__XTENSA_WINDOWED_ABI__) !! 814 fork_like clone3
2202 spill_registers_kernel <<
2203 #elif defined(__XTENSA_CALL0_ABI__) <<
2204 s32i a12, a2, 8 <<
2205 s32i a13, a2, 12 <<
2206 s32i a14, a2, 16 <<
2207 s32i a15, a2, 20 <<
2208 #else <<
2209 #error Unsupported Xtensa ABI <<
2210 #endif <<
2211 abi_call swsusp_save <<
2212 mov a2, abi_rv <<
2213 abi_ret_default <<
2214 <<
2215 ENDPROC(swsusp_arch_suspend) <<
2216 <<
2217 ENTRY(swsusp_arch_resume) <<
2218 815
2219 abi_entry_default !! 816 .macro sigreturn_like name
2220 !! 817 .align 4
2221 #if defined(__XTENSA_WINDOWED_ABI__) !! 818 .globl sys_\name
2222 spill_registers_kernel !! 819 .ent sys_\name
2223 #endif !! 820 sys_\name:
2224 !! 821 .prologue 0
2225 movi a2, restore_pblist !! 822 lda $9, ret_from_straced
2226 l32i a2, a2, 0 !! 823 cmpult $26, $9, $9
2227 !! 824 lda $sp, -SWITCH_STACK_SIZE($sp)
2228 .Lcopy_pbe: !! 825 jsr $26, do_\name
2229 l32i a3, a2, PBE_ADDRESS !! 826 bne $9, 1f
2230 l32i a4, a2, PBE_ORIG_ADDR !! 827 jsr $26, syscall_trace_leave
2231 !! 828 1: br $1, undo_switch_stack
2232 __loopi a3, a9, PAGE_SIZE, 16 !! 829 br ret_from_sys_call
2233 l32i a5, a3, 0 !! 830 .end sys_\name
2234 l32i a6, a3, 4 !! 831 .endm
2235 l32i a7, a3, 8 <<
2236 l32i a8, a3, 12 <<
2237 addi a3, a3, 16 <<
2238 s32i a5, a4, 0 <<
2239 s32i a6, a4, 4 <<
2240 s32i a7, a4, 8 <<
2241 s32i a8, a4, 12 <<
2242 addi a4, a4, 16 <<
2243 __endl a3, a9 <<
2244 <<
2245 l32i a2, a2, PBE_NEXT <<
2246 bnez a2, .Lcopy_pbe <<
2247 <<
2248 movi a2, .Lsaved_regs <<
2249 movi a3, .Lsaved_user_regs <<
2250 l32i a0, a2, 0 <<
2251 l32i a1, a2, 4 <<
2252 load_xtregs_user a3 a4 a5 a6 a7 a8 0 <<
2253 #if defined(__XTENSA_CALL0_ABI__) <<
2254 l32i a12, a2, 8 <<
2255 l32i a13, a2, 12 <<
2256 l32i a14, a2, 16 <<
2257 l32i a15, a2, 20 <<
2258 #endif <<
2259 movi a2, 0 <<
2260 abi_ret_default <<
2261 832
2262 ENDPROC(swsusp_arch_resume) !! 833 sigreturn_like sigreturn
>> 834 sigreturn_like rt_sigreturn
2263 835
2264 #endif !! 836 .align 4
>> 837 .globl alpha_syscall_zero
>> 838 .ent alpha_syscall_zero
>> 839 alpha_syscall_zero:
>> 840 .prologue 0
>> 841 /* Special because it needs to do something opposite to
>> 842 force_successful_syscall_return(). We use the saved
>> 843 syscall number for that, zero meaning "not an error".
>> 844 That works nicely, but for real syscall 0 we need to
>> 845 make sure that this logics doesn't get confused.
>> 846 Store a non-zero there - -ENOSYS we need in register
>> 847 for our return value will do just fine.
>> 848 */
>> 849 lda $0, -ENOSYS
>> 850 unop
>> 851 stq $0, 0($sp)
>> 852 ret
>> 853 .end alpha_syscall_zero
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