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v5.14.15
  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 - 2000, 2001, 2003 Ralf Baechle
  7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 
  8 * Copyright (C) 2002, 2007  Maciej W. Rozycki
  9 * Copyright (C) 2001, 2012 MIPS Technologies, Inc.  All rights reserved.
 10 */
 11#include <linux/init.h>
 12
 13#include <asm/asm.h>
 14#include <asm/asmmacro.h>
 15#include <asm/cacheops.h>
 16#include <asm/irqflags.h>
 17#include <asm/regdef.h>
 18#include <asm/fpregdef.h>
 19#include <asm/mipsregs.h>
 20#include <asm/stackframe.h>
 21#include <asm/sync.h>
 22#include <asm/war.h>
 
 23#include <asm/thread_info.h>
 24
 
 
 
 
 
 
 
 
 
 
 
 25	__INIT
 26
 
 
 
 
 
 
 
 
 27/*
 28 * General exception vector for all other CPUs.
 29 *
 30 * Be careful when changing this, it has to be at most 128 bytes
 31 * to fit into space reserved for the exception handler.
 32 */
 33NESTED(except_vec3_generic, 0, sp)
 34	.set	push
 35	.set	noat
 
 
 
 36	mfc0	k1, CP0_CAUSE
 37	andi	k1, k1, 0x7c
 38#ifdef CONFIG_64BIT
 39	dsll	k1, k1, 1
 40#endif
 41	PTR_L	k0, exception_handlers(k1)
 42	jr	k0
 43	.set	pop
 44	END(except_vec3_generic)
 45
 46/*
 47 * General exception handler for CPUs with virtual coherency exception.
 48 *
 49 * Be careful when changing this, it has to be at most 256 (as a special
 50 * exception) bytes to fit into space reserved for the exception handler.
 51 */
 52NESTED(except_vec3_r4000, 0, sp)
 53	.set	push
 54	.set	arch=r4000
 55	.set	noat
 56	mfc0	k1, CP0_CAUSE
 57	li	k0, 31<<2
 58	andi	k1, k1, 0x7c
 59	.set	push
 60	.set	noreorder
 61	.set	nomacro
 62	beq	k1, k0, handle_vced
 63	 li	k0, 14<<2
 64	beq	k1, k0, handle_vcei
 65#ifdef CONFIG_64BIT
 66	 dsll	k1, k1, 1
 67#endif
 68	.set	pop
 69	PTR_L	k0, exception_handlers(k1)
 70	jr	k0
 71
 72	/*
 73	 * Big shit, we now may have two dirty primary cache lines for the same
 74	 * physical address.  We can safely invalidate the line pointed to by
 75	 * c0_badvaddr because after return from this exception handler the
 76	 * load / store will be re-executed.
 77	 */
 78handle_vced:
 79	MFC0	k0, CP0_BADVADDR
 80	li	k1, -4					# Is this ...
 81	and	k0, k1					# ... really needed?
 82	mtc0	zero, CP0_TAGLO
 83	cache	Index_Store_Tag_D, (k0)
 84	cache	Hit_Writeback_Inv_SD, (k0)
 85#ifdef CONFIG_PROC_FS
 86	PTR_LA	k0, vced_count
 87	lw	k1, (k0)
 88	addiu	k1, 1
 89	sw	k1, (k0)
 90#endif
 91	eret
 92
 93handle_vcei:
 94	MFC0	k0, CP0_BADVADDR
 95	cache	Hit_Writeback_Inv_SD, (k0)		# also cleans pi
 96#ifdef CONFIG_PROC_FS
 97	PTR_LA	k0, vcei_count
 98	lw	k1, (k0)
 99	addiu	k1, 1
100	sw	k1, (k0)
101#endif
102	eret
103	.set	pop
104	END(except_vec3_r4000)
105
106	__FINIT
107
108	.align	5	/* 32 byte rollback region */
109LEAF(__r4k_wait)
110	.set	push
111	.set	noreorder
112	/* start of rollback region */
113	LONG_L	t0, TI_FLAGS($28)
114	nop
115	andi	t0, _TIF_NEED_RESCHED
116	bnez	t0, 1f
117	 nop
118	nop
119	nop
120#ifdef CONFIG_CPU_MICROMIPS
121	nop
122	nop
123	nop
124	nop
125#endif
126	.set	MIPS_ISA_ARCH_LEVEL_RAW
127	wait
128	/* end of rollback region (the region size must be power of two) */
 
1291:
130	jr	ra
131	 nop
132	.set	pop
133	END(__r4k_wait)
134
135	.macro	BUILD_ROLLBACK_PROLOGUE handler
136	FEXPORT(rollback_\handler)
137	.set	push
138	.set	noat
139	MFC0	k0, CP0_EPC
140	PTR_LA	k1, __r4k_wait
141	ori	k0, 0x1f	/* 32 byte rollback region */
142	xori	k0, 0x1f
143	bne	k0, k1, \handler
144	MTC0	k0, CP0_EPC
 
145	.set pop
146	.endm
147
148	.align	5
149BUILD_ROLLBACK_PROLOGUE handle_int
150NESTED(handle_int, PT_SIZE, sp)
151	.cfi_signal_frame
152#ifdef CONFIG_TRACE_IRQFLAGS
153	/*
154	 * Check to see if the interrupted code has just disabled
155	 * interrupts and ignore this interrupt for now if so.
156	 *
157	 * local_irq_disable() disables interrupts and then calls
158	 * trace_hardirqs_off() to track the state. If an interrupt is taken
159	 * after interrupts are disabled but before the state is updated
160	 * it will appear to restore_all that it is incorrectly returning with
161	 * interrupts disabled
162	 */
163	.set	push
164	.set	noat
165	mfc0	k0, CP0_STATUS
166#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
167	and	k0, ST0_IEP
168	bnez	k0, 1f
169
170	mfc0	k0, CP0_EPC
171	.set	noreorder
172	j	k0
173	 rfe
174#else
175	and	k0, ST0_IE
176	bnez	k0, 1f
177
178	eret
179#endif
1801:
181	.set pop
182#endif
183	SAVE_ALL docfi=1
184	CLI
185	TRACE_IRQS_OFF
186
187	LONG_L	s0, TI_REGS($28)
188	LONG_S	sp, TI_REGS($28)
189
190	/*
191	 * SAVE_ALL ensures we are using a valid kernel stack for the thread.
192	 * Check if we are already using the IRQ stack.
193	 */
194	move	s1, sp # Preserve the sp
195
196	/* Get IRQ stack for this CPU */
197	ASM_CPUID_MFC0	k0, ASM_SMP_CPUID_REG
198#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
199	lui	k1, %hi(irq_stack)
200#else
201	lui	k1, %highest(irq_stack)
202	daddiu	k1, %higher(irq_stack)
203	dsll	k1, 16
204	daddiu	k1, %hi(irq_stack)
205	dsll	k1, 16
206#endif
207	LONG_SRL	k0, SMP_CPUID_PTRSHIFT
208	LONG_ADDU	k1, k0
209	LONG_L	t0, %lo(irq_stack)(k1)
210
211	# Check if already on IRQ stack
212	PTR_LI	t1, ~(_THREAD_SIZE-1)
213	and	t1, t1, sp
214	beq	t0, t1, 2f
215
216	/* Switch to IRQ stack */
217	li	t1, _IRQ_STACK_START
218	PTR_ADD sp, t0, t1
219
220	/* Save task's sp on IRQ stack so that unwinding can follow it */
221	LONG_S	s1, 0(sp)
2222:
223	jal	plat_irq_dispatch
224
225	/* Restore sp */
226	move	sp, s1
227
228	j	ret_from_irq
229#ifdef CONFIG_CPU_MICROMIPS
230	nop
231#endif
232	END(handle_int)
233
234	__INIT
235
236/*
237 * Special interrupt vector for MIPS64 ISA & embedded MIPS processors.
238 * This is a dedicated interrupt exception vector which reduces the
239 * interrupt processing overhead.  The jump instruction will be replaced
240 * at the initialization time.
241 *
242 * Be careful when changing this, it has to be at most 128 bytes
243 * to fit into space reserved for the exception handler.
244 */
245NESTED(except_vec4, 0, sp)
2461:	j	1b			/* Dummy, will be replaced */
247	END(except_vec4)
248
249/*
250 * EJTAG debug exception handler.
251 * The EJTAG debug exception entry point is 0xbfc00480, which
252 * normally is in the boot PROM, so the boot PROM must do an
253 * unconditional jump to this vector.
254 */
255NESTED(except_vec_ejtag_debug, 0, sp)
256	j	ejtag_debug_handler
257#ifdef CONFIG_CPU_MICROMIPS
258	 nop
259#endif
260	END(except_vec_ejtag_debug)
261
262	__FINIT
263
264/*
265 * Vectored interrupt handler.
266 * This prototype is copied to ebase + n*IntCtl.VS and patched
267 * to invoke the handler
268 */
269BUILD_ROLLBACK_PROLOGUE except_vec_vi
270NESTED(except_vec_vi, 0, sp)
271	SAVE_SOME docfi=1
272	SAVE_AT docfi=1
273	.set	push
274	.set	noreorder
275	PTR_LA	v1, except_vec_vi_handler
 
 
 
 
 
 
 
 
276FEXPORT(except_vec_vi_lui)
277	lui	v0, 0		/* Patched */
278	jr	v1
279FEXPORT(except_vec_vi_ori)
280	 ori	v0, 0		/* Patched */
281	.set	pop
282	END(except_vec_vi)
283EXPORT(except_vec_vi_end)
284
285/*
286 * Common Vectored Interrupt code
287 * Complete the register saves and invoke the handler which is passed in $v0
288 */
289NESTED(except_vec_vi_handler, 0, sp)
290	SAVE_TEMP
291	SAVE_STATIC
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
292	CLI
293#ifdef CONFIG_TRACE_IRQFLAGS
294	move	s0, v0
 
 
 
295	TRACE_IRQS_OFF
 
 
 
296	move	v0, s0
297#endif
298
299	LONG_L	s0, TI_REGS($28)
300	LONG_S	sp, TI_REGS($28)
301
302	/*
303	 * SAVE_ALL ensures we are using a valid kernel stack for the thread.
304	 * Check if we are already using the IRQ stack.
305	 */
306	move	s1, sp # Preserve the sp
307
308	/* Get IRQ stack for this CPU */
309	ASM_CPUID_MFC0	k0, ASM_SMP_CPUID_REG
310#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
311	lui	k1, %hi(irq_stack)
312#else
313	lui	k1, %highest(irq_stack)
314	daddiu	k1, %higher(irq_stack)
315	dsll	k1, 16
316	daddiu	k1, %hi(irq_stack)
317	dsll	k1, 16
318#endif
319	LONG_SRL	k0, SMP_CPUID_PTRSHIFT
320	LONG_ADDU	k1, k0
321	LONG_L	t0, %lo(irq_stack)(k1)
322
323	# Check if already on IRQ stack
324	PTR_LI	t1, ~(_THREAD_SIZE-1)
325	and	t1, t1, sp
326	beq	t0, t1, 2f
327
328	/* Switch to IRQ stack */
329	li	t1, _IRQ_STACK_START
330	PTR_ADD sp, t0, t1
331
332	/* Save task's sp on IRQ stack so that unwinding can follow it */
333	LONG_S	s1, 0(sp)
3342:
335	jalr	v0
336
337	/* Restore sp */
338	move	sp, s1
339
340	j	ret_from_irq
341	END(except_vec_vi_handler)
342
343/*
344 * EJTAG debug exception handler.
345 */
346NESTED(ejtag_debug_handler, PT_SIZE, sp)
347	.set	push
348	.set	noat
349	MTC0	k0, CP0_DESAVE
350	mfc0	k0, CP0_DEBUG
351
352	andi	k0, k0, MIPS_DEBUG_DBP	# Check for SDBBP.
353	beqz	k0, ejtag_return
354
355#ifdef CONFIG_SMP
3561:	PTR_LA	k0, ejtag_debug_buffer_spinlock
357	__SYNC(full, loongson3_war)
3582:	ll	k0, 0(k0)
359	bnez	k0, 2b
360	PTR_LA	k0, ejtag_debug_buffer_spinlock
361	sc	k0, 0(k0)
362	beqz	k0, 1b
363# ifdef CONFIG_WEAK_REORDERING_BEYOND_LLSC
364	sync
365# endif
366
367	PTR_LA	k0, ejtag_debug_buffer
368	LONG_S	k1, 0(k0)
369
370	ASM_CPUID_MFC0 k1, ASM_SMP_CPUID_REG
371	PTR_SRL	k1, SMP_CPUID_PTRSHIFT
372	PTR_SLL	k1, LONGLOG
373	PTR_LA	k0, ejtag_debug_buffer_per_cpu
374	PTR_ADDU k0, k1
375
376	PTR_LA	k1, ejtag_debug_buffer
377	LONG_L	k1, 0(k1)
378	LONG_S	k1, 0(k0)
379
380	PTR_LA	k0, ejtag_debug_buffer_spinlock
381	sw	zero, 0(k0)
382#else
383	PTR_LA	k0, ejtag_debug_buffer
384	LONG_S	k1, 0(k0)
385#endif
386
387	SAVE_ALL
388	move	a0, sp
389	jal	ejtag_exception_handler
390	RESTORE_ALL
391
392#ifdef CONFIG_SMP
393	ASM_CPUID_MFC0 k1, ASM_SMP_CPUID_REG
394	PTR_SRL	k1, SMP_CPUID_PTRSHIFT
395	PTR_SLL	k1, LONGLOG
396	PTR_LA	k0, ejtag_debug_buffer_per_cpu
397	PTR_ADDU k0, k1
398	LONG_L	k1, 0(k0)
399#else
400	PTR_LA	k0, ejtag_debug_buffer
401	LONG_L	k1, 0(k0)
402#endif
403
404ejtag_return:
405	back_to_back_c0_hazard
406	MFC0	k0, CP0_DESAVE
407	.set	mips32
408	deret
409	.set	pop
410	END(ejtag_debug_handler)
411
412/*
413 * This buffer is reserved for the use of the EJTAG debug
414 * handler.
415 */
416	.data
417EXPORT(ejtag_debug_buffer)
418	.fill	LONGSIZE
419#ifdef CONFIG_SMP
420EXPORT(ejtag_debug_buffer_spinlock)
421	.fill	LONGSIZE
422EXPORT(ejtag_debug_buffer_per_cpu)
423	.fill	LONGSIZE * NR_CPUS
424#endif
425	.previous
426
427	__INIT
428
429/*
430 * NMI debug exception handler for MIPS reference boards.
431 * The NMI debug exception entry point is 0xbfc00000, which
432 * normally is in the boot PROM, so the boot PROM must do a
433 * unconditional jump to this vector.
434 */
435NESTED(except_vec_nmi, 0, sp)
436	j	nmi_handler
437#ifdef CONFIG_CPU_MICROMIPS
438	 nop
439#endif
440	END(except_vec_nmi)
441
442	__FINIT
443
444NESTED(nmi_handler, PT_SIZE, sp)
445	.cfi_signal_frame
446	.set	push
447	.set	noat
448	/*
449	 * Clear ERL - restore segment mapping
450	 * Clear BEV - required for page fault exception handler to work
451	 */
452	mfc0	k0, CP0_STATUS
453	ori	k0, k0, ST0_EXL
454	li	k1, ~(ST0_BEV | ST0_ERL)
455	and	k0, k0, k1
456	mtc0	k0, CP0_STATUS
457	_ehb
458	SAVE_ALL
459	move	a0, sp
460	jal	nmi_exception_handler
461	/* nmi_exception_handler never returns */
 
 
462	.set	pop
463	END(nmi_handler)
464
465	.macro	__build_clear_none
466	.endm
467
468	.macro	__build_clear_sti
469	TRACE_IRQS_ON
470	STI
471	.endm
472
473	.macro	__build_clear_cli
474	CLI
475	TRACE_IRQS_OFF
476	.endm
477
478	.macro	__build_clear_fpe
479	CLI
480	TRACE_IRQS_OFF
481	.set	push
482	/* gas fails to assemble cfc1 for some archs (octeon).*/ \
483	.set	mips1
484	SET_HARDFLOAT
485	cfc1	a1, fcr31
 
 
 
486	.set	pop
487	.endm
488
489	.macro	__build_clear_msa_fpe
490	CLI
491	TRACE_IRQS_OFF
492	_cfcmsa	a1, MSA_CSR
493	.endm
494
495	.macro	__build_clear_ade
496	MFC0	t0, CP0_BADVADDR
497	PTR_S	t0, PT_BVADDR(sp)
498	KMODE
499	.endm
500
501	.macro __build_clear_gsexc
502	.set	push
503	/*
504	 * We need to specify a selector to access the CP0.Diag1 (GSCause)
505	 * register. All GSExc-equipped processors have MIPS32.
506	 */
507	.set	mips32
508	mfc0	a1, CP0_DIAGNOSTIC1
509	.set	pop
510	TRACE_IRQS_ON
511	STI
512	.endm
513
514	.macro	__BUILD_silent exception
515	.endm
516
517	/* Gas tries to parse the ASM_PRINT argument as a string containing
518	   string escapes and emits bogus warnings if it believes to
519	   recognize an unknown escape code.  So make the arguments
520	   start with an n and gas will believe \n is ok ...  */
521	.macro	__BUILD_verbose nexception
522	LONG_L	a1, PT_EPC(sp)
523#ifdef CONFIG_32BIT
524	ASM_PRINT("Got \nexception at %08lx\012")
525#endif
526#ifdef CONFIG_64BIT
527	ASM_PRINT("Got \nexception at %016lx\012")
528#endif
529	.endm
530
531	.macro	__BUILD_count exception
532	LONG_L	t0,exception_count_\exception
533	LONG_ADDIU	t0, 1
534	LONG_S	t0,exception_count_\exception
535	.comm	exception_count\exception, 8, 8
536	.endm
537
538	.macro	__BUILD_HANDLER exception handler clear verbose ext
539	.align	5
540	NESTED(handle_\exception, PT_SIZE, sp)
541	.cfi_signal_frame
542	.set	noat
543	SAVE_ALL
544	FEXPORT(handle_\exception\ext)
545	__build_clear_\clear
546	.set	at
547	__BUILD_\verbose \exception
548	move	a0, sp
549	jal	do_\handler
550	j	ret_from_exception
551	END(handle_\exception)
552	.endm
553
554	.macro	BUILD_HANDLER exception handler clear verbose
555	__BUILD_HANDLER \exception \handler \clear \verbose _int
556	.endm
557
558	BUILD_HANDLER adel ade ade silent		/* #4  */
559	BUILD_HANDLER ades ade ade silent		/* #5  */
560	BUILD_HANDLER ibe be cli silent			/* #6  */
561	BUILD_HANDLER dbe be cli silent			/* #7  */
562	BUILD_HANDLER bp bp sti silent			/* #9  */
563	BUILD_HANDLER ri ri sti silent			/* #10 */
564	BUILD_HANDLER cpu cpu sti silent		/* #11 */
565	BUILD_HANDLER ov ov sti silent			/* #12 */
566	BUILD_HANDLER tr tr sti silent			/* #13 */
567	BUILD_HANDLER msa_fpe msa_fpe msa_fpe silent	/* #14 */
568#ifdef CONFIG_MIPS_FP_SUPPORT
569	BUILD_HANDLER fpe fpe fpe silent		/* #15 */
570#endif
571	BUILD_HANDLER ftlb ftlb none silent		/* #16 */
572	BUILD_HANDLER gsexc gsexc gsexc silent		/* #16 */
573	BUILD_HANDLER msa msa sti silent		/* #21 */
574	BUILD_HANDLER mdmx mdmx sti silent		/* #22 */
575#ifdef	CONFIG_HARDWARE_WATCHPOINTS
576	/*
577	 * For watch, interrupts will be enabled after the watch
578	 * registers are read.
579	 */
580	BUILD_HANDLER watch watch cli silent		/* #23 */
581#else
582	BUILD_HANDLER watch watch sti verbose		/* #23 */
583#endif
584	BUILD_HANDLER mcheck mcheck cli verbose		/* #24 */
585	BUILD_HANDLER mt mt sti silent			/* #25 */
586	BUILD_HANDLER dsp dsp sti silent		/* #26 */
587	BUILD_HANDLER reserved reserved sti verbose	/* others */
588
589	.align	5
590	LEAF(handle_ri_rdhwr_tlbp)
 
 
 
591	.set	push
592	.set	noat
593	.set	noreorder
594	/* check if TLB contains a entry for EPC */
595	MFC0	k1, CP0_ENTRYHI
596	andi	k1, MIPS_ENTRYHI_ASID | MIPS_ENTRYHI_ASIDX
597	MFC0	k0, CP0_EPC
598	PTR_SRL	k0, _PAGE_SHIFT + 1
599	PTR_SLL	k0, _PAGE_SHIFT + 1
600	or	k1, k0
601	MTC0	k1, CP0_ENTRYHI
602	mtc0_tlbw_hazard
603	tlbp
604	tlb_probe_hazard
605	mfc0	k1, CP0_INDEX
606	.set	pop
607	bltz	k1, handle_ri	/* slow path */
608	/* fall thru */
609	END(handle_ri_rdhwr_tlbp)
 
610
611	LEAF(handle_ri_rdhwr)
612	.set	push
613	.set	noat
614	.set	noreorder
615	/* MIPS32:    0x7c03e83b: rdhwr v1,$29 */
616	/* microMIPS: 0x007d6b3c: rdhwr v1,$29 */
617	MFC0	k1, CP0_EPC
618#if defined(CONFIG_CPU_MICROMIPS) || defined(CONFIG_CPU_MIPS32_R2) || defined(CONFIG_CPU_MIPS64_R2)
619	and	k0, k1, 1
620	beqz	k0, 1f
621	 xor	k1, k0
622	lhu	k0, (k1)
623	lhu	k1, 2(k1)
624	ins	k1, k0, 16, 16
625	lui	k0, 0x007d
626	b	docheck
627	 ori	k0, 0x6b3c
6281:
629	lui	k0, 0x7c03
630	lw	k1, (k1)
631	ori	k0, 0xe83b
632#else
633	andi	k0, k1, 1
634	bnez	k0, handle_ri
635	 lui	k0, 0x7c03
636	lw	k1, (k1)
637	ori	k0, 0xe83b
638#endif
639	.set	reorder
640docheck:
641	bne	k0, k1, handle_ri	/* if not ours */
642
643isrdhwr:
644	/* The insn is rdhwr.  No need to check CAUSE.BD here. */
645	get_saved_sp	/* k1 := current_thread_info */
646	.set	noreorder
647	MFC0	k0, CP0_EPC
648#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
649	ori	k1, _THREAD_MASK
650	xori	k1, _THREAD_MASK
651	LONG_L	v1, TI_TP_VALUE(k1)
652	LONG_ADDIU	k0, 4
653	jr	k0
654	 rfe
655#else
656#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
657	LONG_ADDIU	k0, 4		/* stall on $k0 */
658#else
659	.set	at=v1
660	LONG_ADDIU	k0, 4
661	.set	noat
662#endif
663	MTC0	k0, CP0_EPC
664	/* I hope three instructions between MTC0 and ERET are enough... */
665	ori	k1, _THREAD_MASK
666	xori	k1, _THREAD_MASK
667	LONG_L	v1, TI_TP_VALUE(k1)
668	.set	push
669	.set	arch=r4000
670	eret
671	.set	pop
672#endif
673	.set	pop
674	END(handle_ri_rdhwr)
675
676#ifdef CONFIG_CPU_R4X00_BUGS64
677/* A temporary overflow handler used by check_daddi(). */
678
679	__INIT
680
681	BUILD_HANDLER  daddi_ov daddi_ov none silent	/* #12 */
682#endif
v3.5.6
  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 - 2000, 2001, 2003 Ralf Baechle
  7 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
  8 * Copyright (C) 2001 MIPS Technologies, Inc.
  9 * Copyright (C) 2002, 2007  Maciej W. Rozycki
 
 10 */
 11#include <linux/init.h>
 12
 13#include <asm/asm.h>
 14#include <asm/asmmacro.h>
 15#include <asm/cacheops.h>
 16#include <asm/irqflags.h>
 17#include <asm/regdef.h>
 18#include <asm/fpregdef.h>
 19#include <asm/mipsregs.h>
 20#include <asm/stackframe.h>
 
 21#include <asm/war.h>
 22#include <asm/page.h>
 23#include <asm/thread_info.h>
 24
 25#define PANIC_PIC(msg)					\
 26		.set push;				\
 27		.set	reorder;			\
 28		PTR_LA	a0,8f;				\
 29		.set	noat;				\
 30		PTR_LA	AT, panic;			\
 31		jr	AT;				\
 329:		b	9b;				\
 33		.set	pop;				\
 34		TEXT(msg)
 35
 36	__INIT
 37
 38NESTED(except_vec0_generic, 0, sp)
 39	PANIC_PIC("Exception vector 0 called")
 40	END(except_vec0_generic)
 41
 42NESTED(except_vec1_generic, 0, sp)
 43	PANIC_PIC("Exception vector 1 called")
 44	END(except_vec1_generic)
 45
 46/*
 47 * General exception vector for all other CPUs.
 48 *
 49 * Be careful when changing this, it has to be at most 128 bytes
 50 * to fit into space reserved for the exception handler.
 51 */
 52NESTED(except_vec3_generic, 0, sp)
 53	.set	push
 54	.set	noat
 55#if R5432_CP0_INTERRUPT_WAR
 56	mfc0	k0, CP0_INDEX
 57#endif
 58	mfc0	k1, CP0_CAUSE
 59	andi	k1, k1, 0x7c
 60#ifdef CONFIG_64BIT
 61	dsll	k1, k1, 1
 62#endif
 63	PTR_L	k0, exception_handlers(k1)
 64	jr	k0
 65	.set	pop
 66	END(except_vec3_generic)
 67
 68/*
 69 * General exception handler for CPUs with virtual coherency exception.
 70 *
 71 * Be careful when changing this, it has to be at most 256 (as a special
 72 * exception) bytes to fit into space reserved for the exception handler.
 73 */
 74NESTED(except_vec3_r4000, 0, sp)
 75	.set	push
 76	.set	mips3
 77	.set	noat
 78	mfc0	k1, CP0_CAUSE
 79	li	k0, 31<<2
 80	andi	k1, k1, 0x7c
 81	.set	push
 82	.set	noreorder
 83	.set	nomacro
 84	beq	k1, k0, handle_vced
 85	 li	k0, 14<<2
 86	beq	k1, k0, handle_vcei
 87#ifdef CONFIG_64BIT
 88	 dsll	k1, k1, 1
 89#endif
 90	.set	pop
 91	PTR_L	k0, exception_handlers(k1)
 92	jr	k0
 93
 94	/*
 95	 * Big shit, we now may have two dirty primary cache lines for the same
 96	 * physical address.  We can safely invalidate the line pointed to by
 97	 * c0_badvaddr because after return from this exception handler the
 98	 * load / store will be re-executed.
 99	 */
100handle_vced:
101	MFC0	k0, CP0_BADVADDR
102	li	k1, -4					# Is this ...
103	and	k0, k1					# ... really needed?
104	mtc0	zero, CP0_TAGLO
105	cache	Index_Store_Tag_D, (k0)
106	cache	Hit_Writeback_Inv_SD, (k0)
107#ifdef CONFIG_PROC_FS
108	PTR_LA	k0, vced_count
109	lw	k1, (k0)
110	addiu	k1, 1
111	sw	k1, (k0)
112#endif
113	eret
114
115handle_vcei:
116	MFC0	k0, CP0_BADVADDR
117	cache	Hit_Writeback_Inv_SD, (k0)		# also cleans pi
118#ifdef CONFIG_PROC_FS
119	PTR_LA	k0, vcei_count
120	lw	k1, (k0)
121	addiu	k1, 1
122	sw	k1, (k0)
123#endif
124	eret
125	.set	pop
126	END(except_vec3_r4000)
127
128	__FINIT
129
130	.align	5	/* 32 byte rollback region */
131LEAF(r4k_wait)
132	.set	push
133	.set	noreorder
134	/* start of rollback region */
135	LONG_L	t0, TI_FLAGS($28)
136	nop
137	andi	t0, _TIF_NEED_RESCHED
138	bnez	t0, 1f
139	 nop
140	nop
141	nop
142	.set	mips3
 
 
 
 
 
 
143	wait
144	/* end of rollback region (the region size must be power of two) */
145	.set	pop
1461:
147	jr	ra
148	END(r4k_wait)
 
 
149
150	.macro	BUILD_ROLLBACK_PROLOGUE handler
151	FEXPORT(rollback_\handler)
152	.set	push
153	.set	noat
154	MFC0	k0, CP0_EPC
155	PTR_LA	k1, r4k_wait
156	ori	k0, 0x1f	/* 32 byte rollback region */
157	xori	k0, 0x1f
158	bne	k0, k1, 9f
159	MTC0	k0, CP0_EPC
1609:
161	.set pop
162	.endm
163
164	.align  5
165BUILD_ROLLBACK_PROLOGUE handle_int
166NESTED(handle_int, PT_SIZE, sp)
 
167#ifdef CONFIG_TRACE_IRQFLAGS
168	/*
169	 * Check to see if the interrupted code has just disabled
170	 * interrupts and ignore this interrupt for now if so.
171	 *
172	 * local_irq_disable() disables interrupts and then calls
173	 * trace_hardirqs_off() to track the state. If an interrupt is taken
174	 * after interrupts are disabled but before the state is updated
175	 * it will appear to restore_all that it is incorrectly returning with
176	 * interrupts disabled
177	 */
178	.set	push
179	.set	noat
180	mfc0	k0, CP0_STATUS
181#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
182	and	k0, ST0_IEP
183	bnez	k0, 1f
184
185	mfc0	k0, CP0_EPC
186	.set	noreorder
187	j	k0
188	rfe
189#else
190	and	k0, ST0_IE
191	bnez	k0, 1f
192
193	eret
194#endif
1951:
196	.set pop
197#endif
198	SAVE_ALL
199	CLI
200	TRACE_IRQS_OFF
201
202	LONG_L	s0, TI_REGS($28)
203	LONG_S	sp, TI_REGS($28)
204	PTR_LA	ra, ret_from_irq
205	j	plat_irq_dispatch
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
206	END(handle_int)
207
208	__INIT
209
210/*
211 * Special interrupt vector for MIPS64 ISA & embedded MIPS processors.
212 * This is a dedicated interrupt exception vector which reduces the
213 * interrupt processing overhead.  The jump instruction will be replaced
214 * at the initialization time.
215 *
216 * Be careful when changing this, it has to be at most 128 bytes
217 * to fit into space reserved for the exception handler.
218 */
219NESTED(except_vec4, 0, sp)
2201:	j	1b			/* Dummy, will be replaced */
221	END(except_vec4)
222
223/*
224 * EJTAG debug exception handler.
225 * The EJTAG debug exception entry point is 0xbfc00480, which
226 * normally is in the boot PROM, so the boot PROM must do a
227 * unconditional jump to this vector.
228 */
229NESTED(except_vec_ejtag_debug, 0, sp)
230	j	ejtag_debug_handler
 
 
 
231	END(except_vec_ejtag_debug)
232
233	__FINIT
234
235/*
236 * Vectored interrupt handler.
237 * This prototype is copied to ebase + n*IntCtl.VS and patched
238 * to invoke the handler
239 */
240BUILD_ROLLBACK_PROLOGUE except_vec_vi
241NESTED(except_vec_vi, 0, sp)
242	SAVE_SOME
243	SAVE_AT
244	.set	push
245	.set	noreorder
246#ifdef CONFIG_MIPS_MT_SMTC
247	/*
248	 * To keep from blindly blocking *all* interrupts
249	 * during service by SMTC kernel, we also want to
250	 * pass the IM value to be cleared.
251	 */
252FEXPORT(except_vec_vi_mori)
253	ori	a0, $0, 0
254#endif /* CONFIG_MIPS_MT_SMTC */
255FEXPORT(except_vec_vi_lui)
256	lui	v0, 0		/* Patched */
257	j	except_vec_vi_handler
258FEXPORT(except_vec_vi_ori)
259	 ori	v0, 0		/* Patched */
260	.set	pop
261	END(except_vec_vi)
262EXPORT(except_vec_vi_end)
263
264/*
265 * Common Vectored Interrupt code
266 * Complete the register saves and invoke the handler which is passed in $v0
267 */
268NESTED(except_vec_vi_handler, 0, sp)
269	SAVE_TEMP
270	SAVE_STATIC
271#ifdef CONFIG_MIPS_MT_SMTC
272	/*
273	 * SMTC has an interesting problem that interrupts are level-triggered,
274	 * and the CLI macro will clear EXL, potentially causing a duplicate
275	 * interrupt service invocation. So we need to clear the associated
276	 * IM bit of Status prior to doing CLI, and restore it after the
277	 * service routine has been invoked - we must assume that the
278	 * service routine will have cleared the state, and any active
279	 * level represents a new or otherwised unserviced event...
280	 */
281	mfc0	t1, CP0_STATUS
282	and	t0, a0, t1
283#ifdef CONFIG_MIPS_MT_SMTC_IM_BACKSTOP
284	mfc0	t2, CP0_TCCONTEXT
285	or	t2, t0, t2
286	mtc0	t2, CP0_TCCONTEXT
287#endif /* CONFIG_MIPS_MT_SMTC_IM_BACKSTOP */
288	xor	t1, t1, t0
289	mtc0	t1, CP0_STATUS
290	_ehb
291#endif /* CONFIG_MIPS_MT_SMTC */
292	CLI
293#ifdef CONFIG_TRACE_IRQFLAGS
294	move	s0, v0
295#ifdef CONFIG_MIPS_MT_SMTC
296	move	s1, a0
297#endif
298	TRACE_IRQS_OFF
299#ifdef CONFIG_MIPS_MT_SMTC
300	move	a0, s1
301#endif
302	move	v0, s0
303#endif
304
305	LONG_L	s0, TI_REGS($28)
306	LONG_S	sp, TI_REGS($28)
307	PTR_LA	ra, ret_from_irq
308	jr	v0
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
309	END(except_vec_vi_handler)
310
311/*
312 * EJTAG debug exception handler.
313 */
314NESTED(ejtag_debug_handler, PT_SIZE, sp)
315	.set	push
316	.set	noat
317	MTC0	k0, CP0_DESAVE
318	mfc0	k0, CP0_DEBUG
319
320	sll	k0, k0, 30	# Check for SDBBP.
321	bgez	k0, ejtag_return
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
322
 
 
 
 
 
 
 
323	PTR_LA	k0, ejtag_debug_buffer
324	LONG_S	k1, 0(k0)
 
 
325	SAVE_ALL
326	move	a0, sp
327	jal	ejtag_exception_handler
328	RESTORE_ALL
 
 
 
 
 
 
 
 
 
329	PTR_LA	k0, ejtag_debug_buffer
330	LONG_L	k1, 0(k0)
 
331
332ejtag_return:
 
333	MFC0	k0, CP0_DESAVE
334	.set	mips32
335	deret
336	.set pop
337	END(ejtag_debug_handler)
338
339/*
340 * This buffer is reserved for the use of the EJTAG debug
341 * handler.
342 */
343	.data
344EXPORT(ejtag_debug_buffer)
345	.fill	LONGSIZE
 
 
 
 
 
 
346	.previous
347
348	__INIT
349
350/*
351 * NMI debug exception handler for MIPS reference boards.
352 * The NMI debug exception entry point is 0xbfc00000, which
353 * normally is in the boot PROM, so the boot PROM must do a
354 * unconditional jump to this vector.
355 */
356NESTED(except_vec_nmi, 0, sp)
357	j	nmi_handler
 
 
 
358	END(except_vec_nmi)
359
360	__FINIT
361
362NESTED(nmi_handler, PT_SIZE, sp)
 
363	.set	push
364	.set	noat
 
 
 
 
 
 
 
 
 
 
365	SAVE_ALL
366 	move	a0, sp
367	jal	nmi_exception_handler
368	RESTORE_ALL
369	.set	mips3
370	eret
371	.set	pop
372	END(nmi_handler)
373
374	.macro	__build_clear_none
375	.endm
376
377	.macro	__build_clear_sti
378	TRACE_IRQS_ON
379	STI
380	.endm
381
382	.macro	__build_clear_cli
383	CLI
384	TRACE_IRQS_OFF
385	.endm
386
387	.macro	__build_clear_fpe
 
 
388	.set	push
389	/* gas fails to assemble cfc1 for some archs (octeon).*/ \
390	.set	mips1
 
391	cfc1	a1, fcr31
392	li	a2, ~(0x3f << 12)
393	and	a2, a1
394	ctc1	a2, fcr31
395	.set	pop
396	TRACE_IRQS_ON
397	STI
 
 
 
 
398	.endm
399
400	.macro	__build_clear_ade
401	MFC0	t0, CP0_BADVADDR
402	PTR_S	t0, PT_BVADDR(sp)
403	KMODE
404	.endm
405
 
 
 
 
 
 
 
 
 
 
 
 
 
406	.macro	__BUILD_silent exception
407	.endm
408
409	/* Gas tries to parse the PRINT argument as a string containing
410	   string escapes and emits bogus warnings if it believes to
411	   recognize an unknown escape code.  So make the arguments
412	   start with an n and gas will believe \n is ok ...  */
413	.macro	__BUILD_verbose	nexception
414	LONG_L	a1, PT_EPC(sp)
415#ifdef CONFIG_32BIT
416	PRINT("Got \nexception at %08lx\012")
417#endif
418#ifdef CONFIG_64BIT
419	PRINT("Got \nexception at %016lx\012")
420#endif
421	.endm
422
423	.macro	__BUILD_count exception
424	LONG_L	t0,exception_count_\exception
425	LONG_ADDIU t0, 1
426	LONG_S	t0,exception_count_\exception
427	.comm	exception_count\exception, 8, 8
428	.endm
429
430	.macro	__BUILD_HANDLER exception handler clear verbose ext
431	.align	5
432	NESTED(handle_\exception, PT_SIZE, sp)
 
433	.set	noat
434	SAVE_ALL
435	FEXPORT(handle_\exception\ext)
436	__BUILD_clear_\clear
437	.set	at
438	__BUILD_\verbose \exception
439	move	a0, sp
440	PTR_LA	ra, ret_from_exception
441	j	do_\handler
442	END(handle_\exception)
443	.endm
444
445	.macro	BUILD_HANDLER exception handler clear verbose
446	__BUILD_HANDLER	\exception \handler \clear \verbose _int
447	.endm
448
449	BUILD_HANDLER adel ade ade silent		/* #4  */
450	BUILD_HANDLER ades ade ade silent		/* #5  */
451	BUILD_HANDLER ibe be cli silent			/* #6  */
452	BUILD_HANDLER dbe be cli silent			/* #7  */
453	BUILD_HANDLER bp bp sti silent			/* #9  */
454	BUILD_HANDLER ri ri sti silent			/* #10 */
455	BUILD_HANDLER cpu cpu sti silent		/* #11 */
456	BUILD_HANDLER ov ov sti silent			/* #12 */
457	BUILD_HANDLER tr tr sti silent			/* #13 */
 
 
458	BUILD_HANDLER fpe fpe fpe silent		/* #15 */
 
 
 
 
459	BUILD_HANDLER mdmx mdmx sti silent		/* #22 */
460#ifdef 	CONFIG_HARDWARE_WATCHPOINTS
461	/*
462	 * For watch, interrupts will be enabled after the watch
463	 * registers are read.
464	 */
465	BUILD_HANDLER watch watch cli silent		/* #23 */
466#else
467	BUILD_HANDLER watch watch sti verbose		/* #23 */
468#endif
469	BUILD_HANDLER mcheck mcheck cli verbose		/* #24 */
470	BUILD_HANDLER mt mt sti silent			/* #25 */
471	BUILD_HANDLER dsp dsp sti silent		/* #26 */
472	BUILD_HANDLER reserved reserved sti verbose	/* others */
473
474	.align	5
475	LEAF(handle_ri_rdhwr_vivt)
476#ifdef CONFIG_MIPS_MT_SMTC
477	PANIC_PIC("handle_ri_rdhwr_vivt called")
478#else
479	.set	push
480	.set	noat
481	.set	noreorder
482	/* check if TLB contains a entry for EPC */
483	MFC0	k1, CP0_ENTRYHI
484	andi	k1, 0xff	/* ASID_MASK */
485	MFC0	k0, CP0_EPC
486	PTR_SRL	k0, PAGE_SHIFT + 1
487	PTR_SLL	k0, PAGE_SHIFT + 1
488	or	k1, k0
489	MTC0	k1, CP0_ENTRYHI
490	mtc0_tlbw_hazard
491	tlbp
492	tlb_probe_hazard
493	mfc0	k1, CP0_INDEX
494	.set	pop
495	bltz	k1, handle_ri	/* slow path */
496	/* fall thru */
497#endif
498	END(handle_ri_rdhwr_vivt)
499
500	LEAF(handle_ri_rdhwr)
501	.set	push
502	.set	noat
503	.set	noreorder
504	/* 0x7c03e83b: rdhwr v1,$29 */
 
505	MFC0	k1, CP0_EPC
 
 
 
 
 
 
 
 
 
 
 
506	lui	k0, 0x7c03
507	lw	k1, (k1)
508	ori	k0, 0xe83b
 
 
 
 
 
 
 
509	.set	reorder
 
510	bne	k0, k1, handle_ri	/* if not ours */
 
 
511	/* The insn is rdhwr.  No need to check CAUSE.BD here. */
512	get_saved_sp	/* k1 := current_thread_info */
513	.set	noreorder
514	MFC0	k0, CP0_EPC
515#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
516	ori	k1, _THREAD_MASK
517	xori	k1, _THREAD_MASK
518	LONG_L	v1, TI_TP_VALUE(k1)
519	LONG_ADDIU	k0, 4
520	jr	k0
521	 rfe
522#else
523#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
524	LONG_ADDIU	k0, 4		/* stall on $k0 */
525#else
526	.set	at=v1
527	LONG_ADDIU	k0, 4
528	.set	noat
529#endif
530	MTC0	k0, CP0_EPC
531	/* I hope three instructions between MTC0 and ERET are enough... */
532	ori	k1, _THREAD_MASK
533	xori	k1, _THREAD_MASK
534	LONG_L	v1, TI_TP_VALUE(k1)
535	.set	mips3
 
536	eret
537	.set	mips0
538#endif
539	.set	pop
540	END(handle_ri_rdhwr)
541
542#ifdef CONFIG_64BIT
543/* A temporary overflow handler used by check_daddi(). */
544
545	__INIT
546
547	BUILD_HANDLER  daddi_ov daddi_ov none silent	/* #12 */
548#endif