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First Support on Ginger and OMAP TI
[linux-ginger.git] / arch / mips / include / asm / stackframe.h
blobdb0fa7b5aeaf3f849d0a197f63c7a1ba8a487498
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 LONG_S v1, PT_HI(sp)
55 mflo v1
56 LONG_S v1, PT_LO(sp)
57 #endif
58 #ifdef CONFIG_32BIT
59 LONG_S $8, PT_R8(sp)
60 LONG_S $9, PT_R9(sp)
61 #endif
62 LONG_S $10, PT_R10(sp)
63 LONG_S $11, PT_R11(sp)
64 LONG_S $12, PT_R12(sp)
65 LONG_S $13, PT_R13(sp)
66 LONG_S $14, PT_R14(sp)
67 LONG_S $15, PT_R15(sp)
68 LONG_S $24, PT_R24(sp)
69 .endm
70
71 .macro SAVE_STATIC
72 LONG_S $16, PT_R16(sp)
73 LONG_S $17, PT_R17(sp)
74 LONG_S $18, PT_R18(sp)
75 LONG_S $19, PT_R19(sp)
76 LONG_S $20, PT_R20(sp)
77 LONG_S $21, PT_R21(sp)
78 LONG_S $22, PT_R22(sp)
79 LONG_S $23, PT_R23(sp)
80 LONG_S $30, PT_R30(sp)
81 .endm
82
83 #ifdef CONFIG_SMP
84 #ifdef CONFIG_MIPS_MT_SMTC
85 #define PTEBASE_SHIFT 19 /* TCBIND */
86 #else
87 #define PTEBASE_SHIFT 23 /* CONTEXT */
88 #endif
89 .macro get_saved_sp /* SMP variation */
90 #ifdef CONFIG_MIPS_MT_SMTC
91 mfc0 k0, CP0_TCBIND
92 #else
93 MFC0 k0, CP0_CONTEXT
94 #endif
95 #if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
96 lui k1, %hi(kernelsp)
97 #else
98 lui k1, %highest(kernelsp)
99 daddiu k1, %higher(kernelsp)
100 dsll k1, 16
101 daddiu k1, %hi(kernelsp)
102 dsll k1, 16
103 #endif
104 LONG_SRL k0, PTEBASE_SHIFT
105 LONG_ADDU k1, k0
106 LONG_L k1, %lo(kernelsp)(k1)
107 .endm
108
109 .macro set_saved_sp stackp temp temp2
110 #ifdef CONFIG_MIPS_MT_SMTC
111 mfc0 \temp, CP0_TCBIND
112 #else
113 MFC0 \temp, CP0_CONTEXT
114 #endif
115 LONG_SRL \temp, PTEBASE_SHIFT
116 LONG_S \stackp, kernelsp(\temp)
117 .endm
118 #else
119 .macro get_saved_sp /* Uniprocessor variation */
120 #if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
121 lui k1, %hi(kernelsp)
122 #else
123 lui k1, %highest(kernelsp)
124 daddiu k1, %higher(kernelsp)
125 dsll k1, k1, 16
126 daddiu k1, %hi(kernelsp)
127 dsll k1, k1, 16
128 #endif
129 LONG_L k1, %lo(kernelsp)(k1)
130 .endm
131
132 .macro set_saved_sp stackp temp temp2
133 LONG_S \stackp, kernelsp
134 .endm
135 #endif
136
137 .macro SAVE_SOME
138 .set push
139 .set noat
140 .set reorder
141 mfc0 k0, CP0_STATUS
142 sll k0, 3 /* extract cu0 bit */
143 .set noreorder
144 bltz k0, 8f
145 move k1, sp
146 .set reorder
147 /* Called from user mode, new stack. */
148 get_saved_sp
149 #ifndef CONFIG_CPU_DADDI_WORKAROUNDS
150 8: move k0, sp
151 PTR_SUBU sp, k1, PT_SIZE
152 #else
153 .set at=k0
154 8: PTR_SUBU k1, PT_SIZE
155 .set noat
156 move k0, sp
157 move sp, k1
158 #endif
159 LONG_S k0, PT_R29(sp)
160 LONG_S $3, PT_R3(sp)
161 /*
162 * You might think that you don't need to save $0,
163 * but the FPU emulator and gdb remote debug stub
164 * need it to operate correctly
165 */
166 LONG_S $0, PT_R0(sp)
167 mfc0 v1, CP0_STATUS
168 LONG_S $2, PT_R2(sp)
169 LONG_S v1, PT_STATUS(sp)
170 #ifdef CONFIG_MIPS_MT_SMTC
171 /*
172 * Ideally, these instructions would be shuffled in
173 * to cover the pipeline delay.
174 */
175 .set mips32
176 mfc0 v1, CP0_TCSTATUS
177 .set mips0
178 LONG_S v1, PT_TCSTATUS(sp)
179 #endif /* CONFIG_MIPS_MT_SMTC */
180 LONG_S $4, PT_R4(sp)
181 mfc0 v1, CP0_CAUSE
182 LONG_S $5, PT_R5(sp)
183 LONG_S v1, PT_CAUSE(sp)
184 LONG_S $6, PT_R6(sp)
185 MFC0 v1, CP0_EPC
186 LONG_S $7, PT_R7(sp)
187 #ifdef CONFIG_64BIT
188 LONG_S $8, PT_R8(sp)
189 LONG_S $9, PT_R9(sp)
190 #endif
191 LONG_S v1, PT_EPC(sp)
192 LONG_S $25, PT_R25(sp)
193 LONG_S $28, PT_R28(sp)
194 LONG_S $31, PT_R31(sp)
195 ori $28, sp, _THREAD_MASK
196 xori $28, _THREAD_MASK
197 #ifdef CONFIG_CPU_CAVIUM_OCTEON
198 .set mips64
199 pref 0, 0($28) /* Prefetch the current pointer */
200 pref 0, PT_R31(sp) /* Prefetch the $31(ra) */
201 /* The Octeon multiplier state is affected by general multiply
202 instructions. It must be saved before and kernel code might
203 corrupt it */
204 jal octeon_mult_save
205 LONG_L v1, 0($28) /* Load the current pointer */
206 /* Restore $31(ra) that was changed by the jal */
207 LONG_L ra, PT_R31(sp)
208 pref 0, 0(v1) /* Prefetch the current thread */
209 #endif
210 .set pop
211 .endm
212
213 .macro SAVE_ALL
214 SAVE_SOME
215 SAVE_AT
216 SAVE_TEMP
217 SAVE_STATIC
218 .endm
219
220 .macro RESTORE_AT
221 .set push
222 .set noat
223 LONG_L $1, PT_R1(sp)
224 .set pop
225 .endm
226
227 .macro RESTORE_TEMP
228 #ifdef CONFIG_CPU_HAS_SMARTMIPS
229 LONG_L $24, PT_ACX(sp)
230 mtlhx $24
231 LONG_L $24, PT_HI(sp)
232 mtlhx $24
233 LONG_L $24, PT_LO(sp)
234 mtlhx $24
235 #else
236 LONG_L $24, PT_LO(sp)
237 mtlo $24
238 LONG_L $24, PT_HI(sp)
239 mthi $24
240 #endif
241 #ifdef CONFIG_32BIT
242 LONG_L $8, PT_R8(sp)
243 LONG_L $9, PT_R9(sp)
244 #endif
245 LONG_L $10, PT_R10(sp)
246 LONG_L $11, PT_R11(sp)
247 LONG_L $12, PT_R12(sp)
248 LONG_L $13, PT_R13(sp)
249 LONG_L $14, PT_R14(sp)
250 LONG_L $15, PT_R15(sp)
251 LONG_L $24, PT_R24(sp)
252 .endm
253
254 .macro RESTORE_STATIC
255 LONG_L $16, PT_R16(sp)
256 LONG_L $17, PT_R17(sp)
257 LONG_L $18, PT_R18(sp)
258 LONG_L $19, PT_R19(sp)
259 LONG_L $20, PT_R20(sp)
260 LONG_L $21, PT_R21(sp)
261 LONG_L $22, PT_R22(sp)
262 LONG_L $23, PT_R23(sp)
263 LONG_L $30, PT_R30(sp)
264 .endm
265
266 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
267
268 .macro RESTORE_SOME
269 .set push
270 .set reorder
271 .set noat
272 mfc0 a0, CP0_STATUS
273 li v1, 0xff00
274 ori a0, STATMASK
275 xori a0, STATMASK
276 mtc0 a0, CP0_STATUS
277 and a0, v1
278 LONG_L v0, PT_STATUS(sp)
279 nor v1, $0, v1
280 and v0, v1
281 or v0, a0
282 mtc0 v0, CP0_STATUS
283 LONG_L $31, PT_R31(sp)
284 LONG_L $28, PT_R28(sp)
285 LONG_L $25, PT_R25(sp)
286 LONG_L $7, PT_R7(sp)
287 LONG_L $6, PT_R6(sp)
288 LONG_L $5, PT_R5(sp)
289 LONG_L $4, PT_R4(sp)
290 LONG_L $3, PT_R3(sp)
291 LONG_L $2, PT_R2(sp)
292 .set pop
293 .endm
294
295 .macro RESTORE_SP_AND_RET
296 .set push
297 .set noreorder
298 LONG_L k0, PT_EPC(sp)
299 LONG_L sp, PT_R29(sp)
300 jr k0
301 rfe
302 .set pop
303 .endm
304
305 #else
306 .macro RESTORE_SOME
307 .set push
308 .set reorder
309 .set noat
310 #ifdef CONFIG_MIPS_MT_SMTC
311 .set mips32r2
312 /*
313 * We need to make sure the read-modify-write
314 * of Status below isn't perturbed by an interrupt
315 * or cross-TC access, so we need to do at least a DMT,
316 * protected by an interrupt-inhibit. But setting IXMT
317 * also creates a few-cycle window where an IPI could
318 * be queued and not be detected before potentially
319 * returning to a WAIT or user-mode loop. It must be
320 * replayed.
321 *
322 * We're in the middle of a context switch, and
323 * we can't dispatch it directly without trashing
324 * some registers, so we'll try to detect this unlikely
325 * case and program a software interrupt in the VPE,
326 * as would be done for a cross-VPE IPI. To accomodate
327 * the handling of that case, we're doing a DVPE instead
328 * of just a DMT here to protect against other threads.
329 * This is a lot of cruft to cover a tiny window.
330 * If you can find a better design, implement it!
331 *
332 */
333 mfc0 v0, CP0_TCSTATUS
334 ori v0, TCSTATUS_IXMT
335 mtc0 v0, CP0_TCSTATUS
336 _ehb
337 DVPE 5 # dvpe a1
338 jal mips_ihb
339 #endif /* CONFIG_MIPS_MT_SMTC */
340 #ifdef CONFIG_CPU_CAVIUM_OCTEON
341 /* Restore the Octeon multiplier state */
342 jal octeon_mult_restore
343 #endif
344 mfc0 a0, CP0_STATUS
345 ori a0, STATMASK
346 xori a0, STATMASK
347 mtc0 a0, CP0_STATUS
348 li v1, 0xff00
349 and a0, v1
350 LONG_L v0, PT_STATUS(sp)
351 nor v1, $0, v1
352 and v0, v1
353 or v0, a0
354 mtc0 v0, CP0_STATUS
355 #ifdef CONFIG_MIPS_MT_SMTC
356 /*
357 * Only after EXL/ERL have been restored to status can we
358 * restore TCStatus.IXMT.
359 */
360 LONG_L v1, PT_TCSTATUS(sp)
361 _ehb
362 mfc0 a0, CP0_TCSTATUS
363 andi v1, TCSTATUS_IXMT
364 bnez v1, 0f
365
366 /*
367 * We'd like to detect any IPIs queued in the tiny window
368 * above and request an software interrupt to service them
369 * when we ERET.
370 *
371 * Computing the offset into the IPIQ array of the executing
372 * TC's IPI queue in-line would be tedious. We use part of
373 * the TCContext register to hold 16 bits of offset that we
374 * can add in-line to find the queue head.
375 */
376 mfc0 v0, CP0_TCCONTEXT
377 la a2, IPIQ
378 srl v0, v0, 16
379 addu a2, a2, v0
380 LONG_L v0, 0(a2)
381 beqz v0, 0f
382 /*
383 * If we have a queue, provoke dispatch within the VPE by setting C_SW1
384 */
385 mfc0 v0, CP0_CAUSE
386 ori v0, v0, C_SW1
387 mtc0 v0, CP0_CAUSE
388 0:
389 /*
390 * This test should really never branch but
391 * let's be prudent here. Having atomized
392 * the shared register modifications, we can
393 * now EVPE, and must do so before interrupts
394 * are potentially re-enabled.
395 */
396 andi a1, a1, MVPCONTROL_EVP
397 beqz a1, 1f
398 evpe
399 1:
400 /* We know that TCStatua.IXMT should be set from above */
401 xori a0, a0, TCSTATUS_IXMT
402 or a0, a0, v1
403 mtc0 a0, CP0_TCSTATUS
404 _ehb
405
406 .set mips0
407 #endif /* CONFIG_MIPS_MT_SMTC */
408 LONG_L v1, PT_EPC(sp)
409 MTC0 v1, CP0_EPC
410 LONG_L $31, PT_R31(sp)
411 LONG_L $28, PT_R28(sp)
412 LONG_L $25, PT_R25(sp)
413 #ifdef CONFIG_64BIT
414 LONG_L $8, PT_R8(sp)
415 LONG_L $9, PT_R9(sp)
416 #endif
417 LONG_L $7, PT_R7(sp)
418 LONG_L $6, PT_R6(sp)
419 LONG_L $5, PT_R5(sp)
420 LONG_L $4, PT_R4(sp)
421 LONG_L $3, PT_R3(sp)
422 LONG_L $2, PT_R2(sp)
423 .set pop
424 .endm
425
426 .macro RESTORE_SP_AND_RET
427 LONG_L sp, PT_R29(sp)
428 .set mips3
429 eret
430 .set mips0
431 .endm
432
433 #endif
434
435 .macro RESTORE_SP
436 LONG_L sp, PT_R29(sp)
437 .endm
438
439 .macro RESTORE_ALL
440 RESTORE_TEMP
441 RESTORE_STATIC
442 RESTORE_AT
443 RESTORE_SOME
444 RESTORE_SP
445 .endm
446
447 .macro RESTORE_ALL_AND_RET
448 RESTORE_TEMP
449 RESTORE_STATIC
450 RESTORE_AT
451 RESTORE_SOME
452 RESTORE_SP_AND_RET
453 .endm
454
455 /*
456 * Move to kernel mode and disable interrupts.
457 * Set cp0 enable bit as sign that we're running on the kernel stack
458 */
459 .macro CLI
460 #if !defined(CONFIG_MIPS_MT_SMTC)
461 mfc0 t0, CP0_STATUS
462 li t1, ST0_CU0 | STATMASK
463 or t0, t1
464 xori t0, STATMASK
465 mtc0 t0, CP0_STATUS
466 #else /* CONFIG_MIPS_MT_SMTC */
467 /*
468 * For SMTC, we need to set privilege
469 * and disable interrupts only for the
470 * current TC, using the TCStatus register.
471 */
472 mfc0 t0, CP0_TCSTATUS
473 /* Fortunately CU 0 is in the same place in both registers */
474 /* Set TCU0, TMX, TKSU (for later inversion) and IXMT */
475 li t1, ST0_CU0 | 0x08001c00
476 or t0, t1
477 /* Clear TKSU, leave IXMT */
478 xori t0, 0x00001800
479 mtc0 t0, CP0_TCSTATUS
480 _ehb
481 /* We need to leave the global IE bit set, but clear EXL...*/
482 mfc0 t0, CP0_STATUS
483 ori t0, ST0_EXL | ST0_ERL
484 xori t0, ST0_EXL | ST0_ERL
485 mtc0 t0, CP0_STATUS
486 #endif /* CONFIG_MIPS_MT_SMTC */
487 irq_disable_hazard
488 .endm
489
490 /*
491 * Move to kernel mode and enable interrupts.
492 * Set cp0 enable bit as sign that we're running on the kernel stack
493 */
494 .macro STI
495 #if !defined(CONFIG_MIPS_MT_SMTC)
496 mfc0 t0, CP0_STATUS
497 li t1, ST0_CU0 | STATMASK
498 or t0, t1
499 xori t0, STATMASK & ~1
500 mtc0 t0, CP0_STATUS
501 #else /* CONFIG_MIPS_MT_SMTC */
502 /*
503 * For SMTC, we need to set privilege
504 * and enable interrupts only for the
505 * current TC, using the TCStatus register.
506 */
507 _ehb
508 mfc0 t0, CP0_TCSTATUS
509 /* Fortunately CU 0 is in the same place in both registers */
510 /* Set TCU0, TKSU (for later inversion) and IXMT */
511 li t1, ST0_CU0 | 0x08001c00
512 or t0, t1
513 /* Clear TKSU *and* IXMT */
514 xori t0, 0x00001c00
515 mtc0 t0, CP0_TCSTATUS
516 _ehb
517 /* We need to leave the global IE bit set, but clear EXL...*/
518 mfc0 t0, CP0_STATUS
519 ori t0, ST0_EXL
520 xori t0, ST0_EXL
521 mtc0 t0, CP0_STATUS
522 /* irq_enable_hazard below should expand to EHB for 24K/34K cpus */
523 #endif /* CONFIG_MIPS_MT_SMTC */
524 irq_enable_hazard
525 .endm
526
527 /*
528 * Just move to kernel mode and leave interrupts as they are. Note
529 * for the R3000 this means copying the previous enable from IEp.
530 * Set cp0 enable bit as sign that we're running on the kernel stack
531 */
532 .macro KMODE
533 #ifdef CONFIG_MIPS_MT_SMTC
534 /*
535 * This gets baroque in SMTC. We want to
536 * protect the non-atomic clearing of EXL
537 * with DMT/EMT, but we don't want to take
538 * an interrupt while DMT is still in effect.
539 */
540
541 /* KMODE gets invoked from both reorder and noreorder code */
542 .set push
543 .set mips32r2
544 .set noreorder
545 mfc0 v0, CP0_TCSTATUS
546 andi v1, v0, TCSTATUS_IXMT
547 ori v0, TCSTATUS_IXMT
548 mtc0 v0, CP0_TCSTATUS
549 _ehb
550 DMT 2 # dmt v0
551 /*
552 * We don't know a priori if ra is "live"
553 */
554 move t0, ra
555 jal mips_ihb
556 nop /* delay slot */
557 move ra, t0
558 #endif /* CONFIG_MIPS_MT_SMTC */
559 mfc0 t0, CP0_STATUS
560 li t1, ST0_CU0 | (STATMASK & ~1)
561 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
562 andi t2, t0, ST0_IEP
563 srl t2, 2
564 or t0, t2
565 #endif
566 or t0, t1
567 xori t0, STATMASK & ~1
568 mtc0 t0, CP0_STATUS
569 #ifdef CONFIG_MIPS_MT_SMTC
570 _ehb
571 andi v0, v0, VPECONTROL_TE
572 beqz v0, 2f
573 nop /* delay slot */
574 emt
575 2:
576 mfc0 v0, CP0_TCSTATUS
577 /* Clear IXMT, then OR in previous value */
578 ori v0, TCSTATUS_IXMT
579 xori v0, TCSTATUS_IXMT
580 or v0, v1, v0
581 mtc0 v0, CP0_TCSTATUS
582 /*
583 * irq_disable_hazard below should expand to EHB
584 * on 24K/34K CPUS
585 */
586 .set pop
587 #endif /* CONFIG_MIPS_MT_SMTC */
588 irq_disable_hazard
589 .endm
590
591 #endif /* _ASM_STACKFRAME_H */
Linux for Ginger Game Console