Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
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) 1994, 95, 96, 99, 2001 Ralf Baechle
7 * Copyright (C) 1994, 1995, 1996 Paul M. Antoine.
8 * Copyright (C) 1999 Silicon Graphics, Inc.
9 * Copyright (C) 2007 Maciej W. Rozycki
10 */
11#ifndef _ASM_STACKFRAME_H
12#define _ASM_STACKFRAME_H
13
14#include <linux/threads.h>
15
16#include <asm/asm.h>
17#include <asm/asmmacro.h>
18#include <asm/mipsregs.h>
19#include <asm/asm-offsets.h>
20
21/*
22 * For SMTC kernel, global IE should be left set, and interrupts
23 * controlled exclusively via IXMT.
24 */
25#ifdef CONFIG_MIPS_MT_SMTC
26#define STATMASK 0x1e
27#elif defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
28#define STATMASK 0x3f
29#else
30#define STATMASK 0x1f
31#endif
32
33#ifdef CONFIG_MIPS_MT_SMTC
34#include <asm/mipsmtregs.h>
35#endif /* CONFIG_MIPS_MT_SMTC */
36
37 .macro SAVE_AT
38 .set push
39 .set noat
40 LONG_S $1, PT_R1(sp)
41 .set pop
42 .endm
43
44 .macro SAVE_TEMP
45#ifdef CONFIG_CPU_HAS_SMARTMIPS
46 mflhxu v1
47 LONG_S v1, PT_LO(sp)
48 mflhxu v1
49 LONG_S v1, PT_HI(sp)
50 mflhxu v1
51 LONG_S v1, PT_ACX(sp)
52#else
53 mfhi v1
54#endif
55#ifdef CONFIG_32BIT
56 LONG_S $8, PT_R8(sp)
57 LONG_S $9, PT_R9(sp)
58#endif
59 LONG_S $10, PT_R10(sp)
60 LONG_S $11, PT_R11(sp)
61 LONG_S $12, PT_R12(sp)
62#ifndef CONFIG_CPU_HAS_SMARTMIPS
63 LONG_S v1, PT_HI(sp)
64 mflo v1
65#endif
66 LONG_S $13, PT_R13(sp)
67 LONG_S $14, PT_R14(sp)
68 LONG_S $15, PT_R15(sp)
69 LONG_S $24, PT_R24(sp)
70#ifndef CONFIG_CPU_HAS_SMARTMIPS
71 LONG_S v1, PT_LO(sp)
72#endif
73 .endm
74
75 .macro SAVE_STATIC
76 LONG_S $16, PT_R16(sp)
77 LONG_S $17, PT_R17(sp)
78 LONG_S $18, PT_R18(sp)
79 LONG_S $19, PT_R19(sp)
80 LONG_S $20, PT_R20(sp)
81 LONG_S $21, PT_R21(sp)
82 LONG_S $22, PT_R22(sp)
83 LONG_S $23, PT_R23(sp)
84 LONG_S $30, PT_R30(sp)
85 .endm
86
87#ifdef CONFIG_SMP
88#ifdef CONFIG_MIPS_MT_SMTC
89#define PTEBASE_SHIFT 19 /* TCBIND */
90#define CPU_ID_REG CP0_TCBIND
91#define CPU_ID_MFC0 mfc0
92#elif defined(CONFIG_MIPS_PGD_C0_CONTEXT)
93#define PTEBASE_SHIFT 48 /* XCONTEXT */
94#define CPU_ID_REG CP0_XCONTEXT
95#define CPU_ID_MFC0 MFC0
96#else
97#define PTEBASE_SHIFT 23 /* CONTEXT */
98#define CPU_ID_REG CP0_CONTEXT
99#define CPU_ID_MFC0 MFC0
100#endif
101 .macro get_saved_sp /* SMP variation */
102 CPU_ID_MFC0 k0, CPU_ID_REG
103#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
104 lui k1, %hi(kernelsp)
105#else
106 lui k1, %highest(kernelsp)
107 daddiu k1, %higher(kernelsp)
108 dsll k1, 16
109 daddiu k1, %hi(kernelsp)
110 dsll k1, 16
111#endif
112 LONG_SRL k0, PTEBASE_SHIFT
113 LONG_ADDU k1, k0
114 LONG_L k1, %lo(kernelsp)(k1)
115 .endm
116
117 .macro set_saved_sp stackp temp temp2
118 CPU_ID_MFC0 \temp, CPU_ID_REG
119 LONG_SRL \temp, PTEBASE_SHIFT
120 LONG_S \stackp, kernelsp(\temp)
121 .endm
122#else
123 .macro get_saved_sp /* Uniprocessor variation */
124#ifdef CONFIG_CPU_JUMP_WORKAROUNDS
125 /*
126 * Clear BTB (branch target buffer), forbid RAS (return address
127 * stack) to workaround the Out-of-order Issue in Loongson2F
128 * via its diagnostic register.
129 */
130 move k0, ra
131 jal 1f
132 nop
1331: jal 1f
134 nop
1351: jal 1f
136 nop
1371: jal 1f
138 nop
1391: move ra, k0
140 li k0, 3
141 mtc0 k0, $22
142#endif /* CONFIG_CPU_LOONGSON2F */
143#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
144 lui k1, %hi(kernelsp)
145#else
146 lui k1, %highest(kernelsp)
147 daddiu k1, %higher(kernelsp)
148 dsll k1, k1, 16
149 daddiu k1, %hi(kernelsp)
150 dsll k1, k1, 16
151#endif
152 LONG_L k1, %lo(kernelsp)(k1)
153 .endm
154
155 .macro set_saved_sp stackp temp temp2
156 LONG_S \stackp, kernelsp
157 .endm
158#endif
159
160 .macro SAVE_SOME
161 .set push
162 .set noat
163 .set reorder
164 mfc0 k0, CP0_STATUS
165 sll k0, 3 /* extract cu0 bit */
166 .set noreorder
167 bltz k0, 8f
168 move k1, sp
169 .set reorder
170 /* Called from user mode, new stack. */
171 get_saved_sp
172#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
1738: move k0, sp
174 PTR_SUBU sp, k1, PT_SIZE
175#else
176 .set at=k0
1778: PTR_SUBU k1, PT_SIZE
178 .set noat
179 move k0, sp
180 move sp, k1
181#endif
182 LONG_S k0, PT_R29(sp)
183 LONG_S $3, PT_R3(sp)
184 /*
185 * You might think that you don't need to save $0,
186 * but the FPU emulator and gdb remote debug stub
187 * need it to operate correctly
188 */
189 LONG_S $0, PT_R0(sp)
190 mfc0 v1, CP0_STATUS
191 LONG_S $2, PT_R2(sp)
192#ifdef CONFIG_MIPS_MT_SMTC
193 /*
194 * Ideally, these instructions would be shuffled in
195 * to cover the pipeline delay.
196 */
197 .set mips32
198 mfc0 k0, CP0_TCSTATUS
199 .set mips0
200 LONG_S k0, PT_TCSTATUS(sp)
201#endif /* CONFIG_MIPS_MT_SMTC */
202 LONG_S $4, PT_R4(sp)
203 LONG_S $5, PT_R5(sp)
204 LONG_S v1, PT_STATUS(sp)
205 mfc0 v1, CP0_CAUSE
206 LONG_S $6, PT_R6(sp)
207 LONG_S $7, PT_R7(sp)
208 LONG_S v1, PT_CAUSE(sp)
209 MFC0 v1, CP0_EPC
210#ifdef CONFIG_64BIT
211 LONG_S $8, PT_R8(sp)
212 LONG_S $9, PT_R9(sp)
213#endif
214 LONG_S $25, PT_R25(sp)
215 LONG_S $28, PT_R28(sp)
216 LONG_S $31, PT_R31(sp)
217 LONG_S v1, PT_EPC(sp)
218 ori $28, sp, _THREAD_MASK
219 xori $28, _THREAD_MASK
220#ifdef CONFIG_CPU_CAVIUM_OCTEON
221 .set mips64
222 pref 0, 0($28) /* Prefetch the current pointer */
223 pref 0, PT_R31(sp) /* Prefetch the $31(ra) */
224 /* The Octeon multiplier state is affected by general multiply
225 instructions. It must be saved before and kernel code might
226 corrupt it */
227 jal octeon_mult_save
228 LONG_L v1, 0($28) /* Load the current pointer */
229 /* Restore $31(ra) that was changed by the jal */
230 LONG_L ra, PT_R31(sp)
231 pref 0, 0(v1) /* Prefetch the current thread */
232#endif
233 .set pop
234 .endm
235
236 .macro SAVE_ALL
237 SAVE_SOME
238 SAVE_AT
239 SAVE_TEMP
240 SAVE_STATIC
241 .endm
242
243 .macro RESTORE_AT
244 .set push
245 .set noat
246 LONG_L $1, PT_R1(sp)
247 .set pop
248 .endm
249
250 .macro RESTORE_TEMP
251#ifdef CONFIG_CPU_HAS_SMARTMIPS
252 LONG_L $24, PT_ACX(sp)
253 mtlhx $24
254 LONG_L $24, PT_HI(sp)
255 mtlhx $24
256 LONG_L $24, PT_LO(sp)
257 mtlhx $24
258#else
259 LONG_L $24, PT_LO(sp)
260 mtlo $24
261 LONG_L $24, PT_HI(sp)
262 mthi $24
263#endif
264#ifdef CONFIG_32BIT
265 LONG_L $8, PT_R8(sp)
266 LONG_L $9, PT_R9(sp)
267#endif
268 LONG_L $10, PT_R10(sp)
269 LONG_L $11, PT_R11(sp)
270 LONG_L $12, PT_R12(sp)
271 LONG_L $13, PT_R13(sp)
272 LONG_L $14, PT_R14(sp)
273 LONG_L $15, PT_R15(sp)
274 LONG_L $24, PT_R24(sp)
275 .endm
276
277 .macro RESTORE_STATIC
278 LONG_L $16, PT_R16(sp)
279 LONG_L $17, PT_R17(sp)
280 LONG_L $18, PT_R18(sp)
281 LONG_L $19, PT_R19(sp)
282 LONG_L $20, PT_R20(sp)
283 LONG_L $21, PT_R21(sp)
284 LONG_L $22, PT_R22(sp)
285 LONG_L $23, PT_R23(sp)
286 LONG_L $30, PT_R30(sp)
287 .endm
288
289#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
290
291 .macro RESTORE_SOME
292 .set push
293 .set reorder
294 .set noat
295 mfc0 a0, CP0_STATUS
296 li v1, 0xff00
297 ori a0, STATMASK
298 xori a0, STATMASK
299 mtc0 a0, CP0_STATUS
300 and a0, v1
301 LONG_L v0, PT_STATUS(sp)
302 nor v1, $0, v1
303 and v0, v1
304 or v0, a0
305 mtc0 v0, CP0_STATUS
306 LONG_L $31, PT_R31(sp)
307 LONG_L $28, PT_R28(sp)
308 LONG_L $25, PT_R25(sp)
309 LONG_L $7, PT_R7(sp)
310 LONG_L $6, PT_R6(sp)
311 LONG_L $5, PT_R5(sp)
312 LONG_L $4, PT_R4(sp)
313 LONG_L $3, PT_R3(sp)
314 LONG_L $2, PT_R2(sp)
315 .set pop
316 .endm
317
318 .macro RESTORE_SP_AND_RET
319 .set push
320 .set noreorder
321 LONG_L k0, PT_EPC(sp)
322 LONG_L sp, PT_R29(sp)
323 jr k0
324 rfe
325 .set pop
326 .endm
327
328#else
329 .macro RESTORE_SOME
330 .set push
331 .set reorder
332 .set noat
333#ifdef CONFIG_MIPS_MT_SMTC
334 .set mips32r2
335 /*
336 * We need to make sure the read-modify-write
337 * of Status below isn't perturbed by an interrupt
338 * or cross-TC access, so we need to do at least a DMT,
339 * protected by an interrupt-inhibit. But setting IXMT
340 * also creates a few-cycle window where an IPI could
341 * be queued and not be detected before potentially
342 * returning to a WAIT or user-mode loop. It must be
343 * replayed.
344 *
345 * We're in the middle of a context switch, and
346 * we can't dispatch it directly without trashing
347 * some registers, so we'll try to detect this unlikely
348 * case and program a software interrupt in the VPE,
349 * as would be done for a cross-VPE IPI. To accommodate
350 * the handling of that case, we're doing a DVPE instead
351 * of just a DMT here to protect against other threads.
352 * This is a lot of cruft to cover a tiny window.
353 * If you can find a better design, implement it!
354 *
355 */
356 mfc0 v0, CP0_TCSTATUS
357 ori v0, TCSTATUS_IXMT
358 mtc0 v0, CP0_TCSTATUS
359 _ehb
360 DVPE 5 # dvpe a1
361 jal mips_ihb
362#endif /* CONFIG_MIPS_MT_SMTC */
363#ifdef CONFIG_CPU_CAVIUM_OCTEON
364 /* Restore the Octeon multiplier state */
365 jal octeon_mult_restore
366#endif
367 mfc0 a0, CP0_STATUS
368 ori a0, STATMASK
369 xori a0, STATMASK
370 mtc0 a0, CP0_STATUS
371 li v1, 0xff00
372 and a0, v1
373 LONG_L v0, PT_STATUS(sp)
374 nor v1, $0, v1
375 and v0, v1
376 or v0, a0
377 mtc0 v0, CP0_STATUS
378#ifdef CONFIG_MIPS_MT_SMTC
379/*
380 * Only after EXL/ERL have been restored to status can we
381 * restore TCStatus.IXMT.
382 */
383 LONG_L v1, PT_TCSTATUS(sp)
384 _ehb
385 mfc0 a0, CP0_TCSTATUS
386 andi v1, TCSTATUS_IXMT
387 bnez v1, 0f
388
389/*
390 * We'd like to detect any IPIs queued in the tiny window
391 * above and request an software interrupt to service them
392 * when we ERET.
393 *
394 * Computing the offset into the IPIQ array of the executing
395 * TC's IPI queue in-line would be tedious. We use part of
396 * the TCContext register to hold 16 bits of offset that we
397 * can add in-line to find the queue head.
398 */
399 mfc0 v0, CP0_TCCONTEXT
400 la a2, IPIQ
401 srl v0, v0, 16
402 addu a2, a2, v0
403 LONG_L v0, 0(a2)
404 beqz v0, 0f
405/*
406 * If we have a queue, provoke dispatch within the VPE by setting C_SW1
407 */
408 mfc0 v0, CP0_CAUSE
409 ori v0, v0, C_SW1
410 mtc0 v0, CP0_CAUSE
4110:
412 /*
413 * This test should really never branch but
414 * let's be prudent here. Having atomized
415 * the shared register modifications, we can
416 * now EVPE, and must do so before interrupts
417 * are potentially re-enabled.
418 */
419 andi a1, a1, MVPCONTROL_EVP
420 beqz a1, 1f
421 evpe
4221:
423 /* We know that TCStatua.IXMT should be set from above */
424 xori a0, a0, TCSTATUS_IXMT
425 or a0, a0, v1
426 mtc0 a0, CP0_TCSTATUS
427 _ehb
428
429 .set mips0
430#endif /* CONFIG_MIPS_MT_SMTC */
431 LONG_L v1, PT_EPC(sp)
432 MTC0 v1, CP0_EPC
433 LONG_L $31, PT_R31(sp)
434 LONG_L $28, PT_R28(sp)
435 LONG_L $25, PT_R25(sp)
436#ifdef CONFIG_64BIT
437 LONG_L $8, PT_R8(sp)
438 LONG_L $9, PT_R9(sp)
439#endif
440 LONG_L $7, PT_R7(sp)
441 LONG_L $6, PT_R6(sp)
442 LONG_L $5, PT_R5(sp)
443 LONG_L $4, PT_R4(sp)
444 LONG_L $3, PT_R3(sp)
445 LONG_L $2, PT_R2(sp)
446 .set pop
447 .endm
448
449 .macro RESTORE_SP_AND_RET
450 LONG_L sp, PT_R29(sp)
451 .set mips3
452 eret
453 .set mips0
454 .endm
455
456#endif
457
458 .macro RESTORE_SP
459 LONG_L sp, PT_R29(sp)
460 .endm
461
462 .macro RESTORE_ALL
463 RESTORE_TEMP
464 RESTORE_STATIC
465 RESTORE_AT
466 RESTORE_SOME
467 RESTORE_SP
468 .endm
469
470 .macro RESTORE_ALL_AND_RET
471 RESTORE_TEMP
472 RESTORE_STATIC
473 RESTORE_AT
474 RESTORE_SOME
475 RESTORE_SP_AND_RET
476 .endm
477
478/*
479 * Move to kernel mode and disable interrupts.
480 * Set cp0 enable bit as sign that we're running on the kernel stack
481 */
482 .macro CLI
483#if !defined(CONFIG_MIPS_MT_SMTC)
484 mfc0 t0, CP0_STATUS
485 li t1, ST0_CU0 | STATMASK
486 or t0, t1
487 xori t0, STATMASK
488 mtc0 t0, CP0_STATUS
489#else /* CONFIG_MIPS_MT_SMTC */
490 /*
491 * For SMTC, we need to set privilege
492 * and disable interrupts only for the
493 * current TC, using the TCStatus register.
494 */
495 mfc0 t0, CP0_TCSTATUS
496 /* Fortunately CU 0 is in the same place in both registers */
497 /* Set TCU0, TMX, TKSU (for later inversion) and IXMT */
498 li t1, ST0_CU0 | 0x08001c00
499 or t0, t1
500 /* Clear TKSU, leave IXMT */
501 xori t0, 0x00001800
502 mtc0 t0, CP0_TCSTATUS
503 _ehb
504 /* We need to leave the global IE bit set, but clear EXL...*/
505 mfc0 t0, CP0_STATUS
506 ori t0, ST0_EXL | ST0_ERL
507 xori t0, ST0_EXL | ST0_ERL
508 mtc0 t0, CP0_STATUS
509#endif /* CONFIG_MIPS_MT_SMTC */
510 irq_disable_hazard
511 .endm
512
513/*
514 * Move to kernel mode and enable interrupts.
515 * Set cp0 enable bit as sign that we're running on the kernel stack
516 */
517 .macro STI
518#if !defined(CONFIG_MIPS_MT_SMTC)
519 mfc0 t0, CP0_STATUS
520 li t1, ST0_CU0 | STATMASK
521 or t0, t1
522 xori t0, STATMASK & ~1
523 mtc0 t0, CP0_STATUS
524#else /* CONFIG_MIPS_MT_SMTC */
525 /*
526 * For SMTC, we need to set privilege
527 * and enable interrupts only for the
528 * current TC, using the TCStatus register.
529 */
530 _ehb
531 mfc0 t0, CP0_TCSTATUS
532 /* Fortunately CU 0 is in the same place in both registers */
533 /* Set TCU0, TKSU (for later inversion) and IXMT */
534 li t1, ST0_CU0 | 0x08001c00
535 or t0, t1
536 /* Clear TKSU *and* IXMT */
537 xori t0, 0x00001c00
538 mtc0 t0, CP0_TCSTATUS
539 _ehb
540 /* We need to leave the global IE bit set, but clear EXL...*/
541 mfc0 t0, CP0_STATUS
542 ori t0, ST0_EXL
543 xori t0, ST0_EXL
544 mtc0 t0, CP0_STATUS
545 /* irq_enable_hazard below should expand to EHB for 24K/34K cpus */
546#endif /* CONFIG_MIPS_MT_SMTC */
547 irq_enable_hazard
548 .endm
549
550/*
551 * Just move to kernel mode and leave interrupts as they are. Note
552 * for the R3000 this means copying the previous enable from IEp.
553 * Set cp0 enable bit as sign that we're running on the kernel stack
554 */
555 .macro KMODE
556#ifdef CONFIG_MIPS_MT_SMTC
557 /*
558 * This gets baroque in SMTC. We want to
559 * protect the non-atomic clearing of EXL
560 * with DMT/EMT, but we don't want to take
561 * an interrupt while DMT is still in effect.
562 */
563
564 /* KMODE gets invoked from both reorder and noreorder code */
565 .set push
566 .set mips32r2
567 .set noreorder
568 mfc0 v0, CP0_TCSTATUS
569 andi v1, v0, TCSTATUS_IXMT
570 ori v0, TCSTATUS_IXMT
571 mtc0 v0, CP0_TCSTATUS
572 _ehb
573 DMT 2 # dmt v0
574 /*
575 * We don't know a priori if ra is "live"
576 */
577 move t0, ra
578 jal mips_ihb
579 nop /* delay slot */
580 move ra, t0
581#endif /* CONFIG_MIPS_MT_SMTC */
582 mfc0 t0, CP0_STATUS
583 li t1, ST0_CU0 | (STATMASK & ~1)
584#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
585 andi t2, t0, ST0_IEP
586 srl t2, 2
587 or t0, t2
588#endif
589 or t0, t1
590 xori t0, STATMASK & ~1
591 mtc0 t0, CP0_STATUS
592#ifdef CONFIG_MIPS_MT_SMTC
593 _ehb
594 andi v0, v0, VPECONTROL_TE
595 beqz v0, 2f
596 nop /* delay slot */
597 emt
5982:
599 mfc0 v0, CP0_TCSTATUS
600 /* Clear IXMT, then OR in previous value */
601 ori v0, TCSTATUS_IXMT
602 xori v0, TCSTATUS_IXMT
603 or v0, v1, v0
604 mtc0 v0, CP0_TCSTATUS
605 /*
606 * irq_disable_hazard below should expand to EHB
607 * on 24K/34K CPUS
608 */
609 .set pop
610#endif /* CONFIG_MIPS_MT_SMTC */
611 irq_disable_hazard
612 .endm
613
614#endif /* _ASM_STACKFRAME_H */