locore.s revision 1.15
1/*	$NetBSD: locore.s,v 1.15 1997/04/09 20:58:33 thorpej Exp $	*/
2
3/*
4 * Copyright (c) 1988 University of Utah.
5 * Copyright (c) 1980, 1990, 1993
6 *	The Regents of the University of California.  All rights reserved.
7 *
8 * This code is derived from software contributed to Berkeley by
9 * the Systems Programming Group of the University of Utah Computer
10 * Science Department.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. All advertising materials mentioning features or use of this software
21 *    must display the following acknowledgement:
22 *	This product includes software developed by the University of
23 *	California, Berkeley and its contributors.
24 * 4. Neither the name of the University nor the names of its contributors
25 *    may be used to endorse or promote products derived from this software
26 *    without specific prior written permission.
27 *
28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
38 * SUCH DAMAGE.
39 *
40 *	from: Utah $Hdr: locore.s 1.66 92/12/22$
41 *	@(#)locore.s	8.6 (Berkeley) 5/27/94
42 */
43
44#include "assym.h"
45#include <machine/trap.h>
46
47| Remember this is a fun project!
48
49	.data
50	.globl	_mon_crp
51_mon_crp:
52	.long	0,0
53
54| This is for kvm_mkdb, and should be the address of the beginning
55| of the kernel text segment (not necessarily the same as kernbase).
56	.text
57	.globl	_kernel_text
58_kernel_text:
59
60| This is the entry point, as well as the end of the temporary stack
61| used during process switch (one 8K page ending at start)
62	.globl tmpstk
63tmpstk:
64	.globl start
65start:
66| The first step, after disabling interrupts, is to map enough of the kernel
67| into high virtual address space so that we can use position dependent code.
68| This is a tricky task on the sun3x because the MMU is already enabled and
69| the ROM monitor provides no indication of where the root MMU table is mapped.
70| Therefore we must use one of the 68030's 'transparent translation' registers
71| to define a range in the address space where the MMU translation is
72| turned off.  Once this is complete we can modify the MMU table directly
73| without the need for it to be mapped into virtual memory.
74| All code must be position independent until otherwise noted, as the
75| boot loader has loaded us into low memory but all the symbols in this
76| code have been linked high.
77	movw	#PSL_HIGHIPL, sr	| no interrupts
78	movl	#KERNBASE, a5		| for vtop conversion
79	lea	_mon_crp, a0		| where to store the CRP
80	subl	a5, a0
81	| Note: borrowing mon_crp for tt0 setup...
82	movl	#0x3F8107, a0@		| map the low 1GB v=p with the
83	.long	0xf0100800		| transparent translation reg0
84					| [ pmove a0@, tt0 ]
85| In order to map the kernel into high memory we will copy the root table
86| entry which maps the 16 megabytes of memory starting at 0x0 into the
87| entry which maps the 16 megabytes starting at KERNBASE.
88	pmove	crp, a0@		| Get monitor CPU root pointer
89	movl	a0@(4), a1		| 2nd word is PA of level A table
90
91	movl	a1, a0			| compute the descriptor address
92	addl	#0x3e0, a1		| for VA starting at KERNBASE
93	movl	a0@, a1@		| copy descriptor type
94	movl	a0@(4), a1@(4)		| copy physical address
95
96| Kernel is now double mapped at zero and KERNBASE.
97| Force a long jump to the relocated code (high VA).
98	movl	#IC_CLEAR, d0		| Flush the I-cache
99	movc	d0, cacr
100	jmp L_high_code:l		| long jump
101
102L_high_code:
103| We are now running in the correctly relocated kernel, so
104| we are no longer restricted to position-independent code.
105| It is handy to leave transparent translation enabled while
106| for the low 1GB while __bootstrap() is doing its thing.
107
108| Do bootstrap stuff needed before main() gets called.
109| Our boot loader leaves a copy of the kernel's exec header
110| just before the start of the kernel text segment, so the
111| kernel can sanity-check the DDB symbols at [end...esym].
112| Pass the struct exec at tmpstk-32 to __bootstrap().
113| Also, make sure the initial frame pointer is zero so that
114| the backtrace algorithm used by KGDB terminates nicely.
115	lea	tmpstk-32, sp
116	movl	#0,a6
117	jsr	__bootstrap		| See _startup.c
118
119| Now turn off the transparent translation of the low 1GB.
120| (this also flushes the ATC)
121	clrl	sp@-
122	.long	0xf0170800		| pmove	sp@,tt0
123	addql	#4,sp
124
125| Now that __bootstrap() is done using the PROM functions,
126| we can safely set the sfc/dfc to something != FC_CONTROL
127	moveq	#FC_USERD, d0		| make movs access "user data"
128	movc	d0, sfc			| space for copyin/copyout
129	movc	d0, dfc
130
131| Setup process zero user/kernel stacks.
132	movl	_proc0paddr,a1		| get proc0 pcb addr
133	lea	a1@(USPACE-4),sp	| set SSP to last word
134	movl	#USRSTACK-4,a2
135	movl	a2,usp			| init user SP
136
137| Note curpcb was already set in __bootstrap().
138| Will do fpu initialization during autoconfig (see fpu.c)
139| The interrupt vector table and stack are now ready.
140| Interrupts will be enabled later, AFTER  autoconfiguration
141| is finished, to avoid spurrious interrupts.
142
143/*
144 * Final preparation for calling main.
145 *
146 * Create a fake exception frame that returns to user mode,
147 * and save its address in p->p_md.md_regs for cpu_fork().
148 * The new frames for process 1 and 2 will be adjusted by
149 * cpu_set_kpc() to arrange for a call to a kernel function
150 * before the new process does its rte out to user mode.
151 */
152	clrw	sp@-			| tf_format,tf_vector
153	clrl	sp@-			| tf_pc (filled in later)
154	movw	#PSL_USER,sp@-		| tf_sr for user mode
155	clrl	sp@-			| tf_stackadj
156	lea	sp@(-64),sp		| tf_regs[16]
157	movl	sp,a1			| a1=trapframe
158	lea	_proc0,a0		| proc0.p_md.md_regs =
159	movl	a1,a0@(P_MDREGS)	|   trapframe
160	movl	a2,a1@(FR_SP)		| a2 == usp (from above)
161	pea	a1@			| push &trapframe
162	jbsr	_main			| main(&trapframe)
163	addql	#4,sp			| help DDB backtrace
164	trap	#15			| should not get here
165
166| This is used by cpu_fork() to return to user mode.
167| It is called with SP pointing to a struct trapframe.
168	.globl	_proc_do_uret
169_proc_do_uret:
170	movl	sp@(FR_SP),a0		| grab and load
171	movl	a0,usp			|   user SP
172	moveml	sp@+,#0x7FFF		| load most registers (all but SSP)
173	addql	#8,sp			| pop SSP and stack adjust count
174	rte
175
176/*
177 * proc_trampoline:
178 * This is used by cpu_set_kpc() to "push" a function call onto the
179 * kernel stack of some process, very much like a signal delivery.
180 * When we get here, the stack has:
181 *
182 * SP+8:	switchframe from before cpu_set_kpc
183 * SP+4:	void *proc;
184 * SP:  	u_long func;
185 *
186 * On entry, the switchframe pushed by cpu_set_kpc has already been
187 * popped off the stack, so all this needs to do is pop the function
188 * pointer into a register, call it, then pop the arg, and finally
189 * return using the switchframe that remains on the stack.
190 */
191	.globl	_proc_trampoline
192_proc_trampoline:
193	movl	sp@+,a0			| function pointer
194	jbsr	a0@			| (*func)(procp)
195	addql	#4,sp			| toss the arg
196	rts				| as cpu_switch would do
197
198| That is all the assembly startup code we need on the sun3x!
199| The rest of this is like the hp300/locore.s where possible.
200
201/*
202 * Trap/interrupt vector routines
203 */
204
205	.globl _buserr, _addrerr, _illinst, _zerodiv, _chkinst
206	.globl _trapvinst, _privinst, _trace, _badtrap, _fmterr
207	.globl _trap0, _trap1, _trap2, _trap12, _trap15
208	.globl _coperr, _fpfline, _fpunsupp
209
210	.globl	_trap, _nofault, _longjmp
211_buserr:
212	tstl	_nofault		| device probe?
213	jeq	_addrerr		| no, handle as usual
214	movl	_nofault,sp@-		| yes,
215	jbsr	_longjmp		|  longjmp(nofault)
216_addrerr:
217	clrl	sp@-			| stack adjust count
218	moveml	#0xFFFF,sp@-		| save user registers
219	movl	usp,a0			| save the user SP
220	movl	a0,sp@(FR_SP)		|   in the savearea
221	lea	sp@(FR_HW),a1		| grab base of HW berr frame
222	moveq	#0,d0
223	movw	a1@(10),d0		| grab SSW for fault processing
224	btst	#12,d0			| RB set?
225	jeq	LbeX0			| no, test RC
226	bset	#14,d0			| yes, must set FB
227	movw	d0,a1@(10)		| for hardware too
228LbeX0:
229	btst	#13,d0			| RC set?
230	jeq	LbeX1			| no, skip
231	bset	#15,d0			| yes, must set FC
232	movw	d0,a1@(10)		| for hardware too
233LbeX1:
234	btst	#8,d0			| data fault?
235	jeq	Lbe0			| no, check for hard cases
236	movl	a1@(16),d1		| fault address is as given in frame
237	jra	Lbe10			| thats it
238Lbe0:
239	btst	#4,a1@(6)		| long (type B) stack frame?
240	jne	Lbe4			| yes, go handle
241	movl	a1@(2),d1		| no, can use save PC
242	btst	#14,d0			| FB set?
243	jeq	Lbe3			| no, try FC
244	addql	#4,d1			| yes, adjust address
245	jra	Lbe10			| done
246Lbe3:
247	btst	#15,d0			| FC set?
248	jeq	Lbe10			| no, done
249	addql	#2,d1			| yes, adjust address
250	jra	Lbe10			| done
251Lbe4:
252	movl	a1@(36),d1		| long format, use stage B address
253	btst	#15,d0			| FC set?
254	jeq	Lbe10			| no, all done
255	subql	#2,d1			| yes, adjust address
256Lbe10:
257	movl	d1,sp@-			| push fault VA
258	movl	d0,sp@-			| and padded SSW
259	movw	a1@(6),d0		| get frame format/vector offset
260	andw	#0x0FFF,d0		| clear out frame format
261	cmpw	#12,d0			| address error vector?
262	jeq	Lisaerr			| yes, go to it
263
264/* MMU-specific code to determine reason for bus error. */
265	movl	d1,a0			| fault address
266	movl	sp@,d0			| function code from ssw
267	btst	#8,d0			| data fault?
268	jne	Lbe10a
269	movql	#1,d0			| user program access FC
270					| (we dont separate data/program)
271	btst	#5,a1@			| supervisor mode?
272	jeq	Lbe10a			| if no, done
273	movql	#5,d0			| else supervisor program access
274Lbe10a:
275	ptestr	d0,a0@,#7		| do a table search
276	pmove	psr,sp@			| save result
277	movb	sp@,d1
278	btst	#2,d1			| invalid? (incl. limit viol and berr)
279	jeq	Lmightnotbemerr		| no -> wp check
280	btst	#7,d1			| is it MMU table berr?
281	jeq	Lismerr			| no, must be fast
282	jra	Lisberr1		| real bus err needs not be fast
283Lmightnotbemerr:
284	btst	#3,d1			| write protect bit set?
285	jeq	Lisberr1		| no, must be bus error
286	movl	sp@,d0			| ssw into low word of d0
287	andw	#0xc0,d0		| write protect is set on page:
288	cmpw	#0x40,d0		| was it read cycle?
289	jeq	Lisberr1		| yes, was not WPE, must be bus err
290/* End of MMU-specific bus error code. */
291
292Lismerr:
293	movl	#T_MMUFLT,sp@-		| show that we are an MMU fault
294	jra	Ltrapnstkadj		| and deal with it
295Lisaerr:
296	movl	#T_ADDRERR,sp@-		| mark address error
297	jra	Ltrapnstkadj		| and deal with it
298Lisberr1:
299	clrw	sp@			| re-clear pad word
300Lisberr:
301	movl	#T_BUSERR,sp@-		| mark bus error
302Ltrapnstkadj:
303	jbsr	_trap			| handle the error
304	lea	sp@(12),sp		| pop value args
305	movl	sp@(FR_SP),a0		| restore user SP
306	movl	a0,usp			|   from save area
307	movw	sp@(FR_ADJ),d0		| need to adjust stack?
308	jne	Lstkadj			| yes, go to it
309	moveml	sp@+,#0x7FFF		| no, restore most user regs
310	addql	#8,sp			| toss SSP and stkadj
311	jra	rei			| all done
312Lstkadj:
313	lea	sp@(FR_HW),a1		| pointer to HW frame
314	addql	#8,a1			| source pointer
315	movl	a1,a0			| source
316	addw	d0,a0			|  + hole size = dest pointer
317	movl	a1@-,a0@-		| copy
318	movl	a1@-,a0@-		|  8 bytes
319	movl	a0,sp@(FR_SP)		| new SSP
320	moveml	sp@+,#0x7FFF		| restore user registers
321	movl	sp@,sp			| and our SP
322	jra	rei			| all done
323
324/*
325 * FP exceptions.
326 */
327_fpfline:
328	clrl	sp@-			| stack adjust count
329	moveml	#0xFFFF,sp@-		| save registers
330	moveq	#T_FPEMULI,d0		| denote as FP emulation trap
331	jra	fault			| do it
332
333_fpunsupp:
334	clrl	sp@-			| stack adjust count
335	moveml	#0xFFFF,sp@-		| save registers
336	moveq	#T_FPEMULD,d0		| denote as FP emulation trap
337	jra	fault			| do it
338
339/*
340 * Handles all other FP coprocessor exceptions.
341 * Note that since some FP exceptions generate mid-instruction frames
342 * and may cause signal delivery, we need to test for stack adjustment
343 * after the trap call.
344 */
345	.globl	_fpfault
346_fpfault:
347	clrl	sp@-		| stack adjust count
348	moveml	#0xFFFF,sp@-	| save user registers
349	movl	usp,a0		| and save
350	movl	a0,sp@(FR_SP)	|   the user stack pointer
351	clrl	sp@-		| no VA arg
352	movl	_curpcb,a0	| current pcb
353	lea	a0@(PCB_FPCTX),a0 | address of FP savearea
354	fsave	a0@		| save state
355	tstb	a0@		| null state frame?
356	jeq	Lfptnull	| yes, safe
357	clrw	d0		| no, need to tweak BIU
358	movb	a0@(1),d0	| get frame size
359	bset	#3,a0@(0,d0:w)	| set exc_pend bit of BIU
360Lfptnull:
361	fmovem	fpsr,sp@-	| push fpsr as code argument
362	frestore a0@		| restore state
363	movl	#T_FPERR,sp@-	| push type arg
364	jra	Ltrapnstkadj	| call trap and deal with stack cleanup
365
366/*
367 * Coprocessor and format errors can generate mid-instruction stack
368 * frames and cause signal delivery hence we need to check for potential
369 * stack adjustment.
370 */
371_coperr:
372	clrl	sp@-		| stack adjust count
373	moveml	#0xFFFF,sp@-
374	movl	usp,a0		| get and save
375	movl	a0,sp@(FR_SP)	|   the user stack pointer
376	clrl	sp@-		| no VA arg
377	clrl	sp@-		| or code arg
378	movl	#T_COPERR,sp@-	| push trap type
379	jra	Ltrapnstkadj	| call trap and deal with stack adjustments
380
381_fmterr:
382	clrl	sp@-		| stack adjust count
383	moveml	#0xFFFF,sp@-
384	movl	usp,a0		| get and save
385	movl	a0,sp@(FR_SP)	|   the user stack pointer
386	clrl	sp@-		| no VA arg
387	clrl	sp@-		| or code arg
388	movl	#T_FMTERR,sp@-	| push trap type
389	jra	Ltrapnstkadj	| call trap and deal with stack adjustments
390
391/*
392 * Other exceptions only cause four and six word stack frame and require
393 * no post-trap stack adjustment.
394 */
395_illinst:
396	clrl	sp@-
397	moveml	#0xFFFF,sp@-
398	moveq	#T_ILLINST,d0
399	jra	fault
400
401_zerodiv:
402	clrl	sp@-
403	moveml	#0xFFFF,sp@-
404	moveq	#T_ZERODIV,d0
405	jra	fault
406
407_chkinst:
408	clrl	sp@-
409	moveml	#0xFFFF,sp@-
410	moveq	#T_CHKINST,d0
411	jra	fault
412
413_trapvinst:
414	clrl	sp@-
415	moveml	#0xFFFF,sp@-
416	moveq	#T_TRAPVINST,d0
417	jra	fault
418
419_privinst:
420	clrl	sp@-
421	moveml	#0xFFFF,sp@-
422	moveq	#T_PRIVINST,d0
423	jra	fault
424
425	.globl	fault
426fault:
427	movl	usp,a0			| get and save
428	movl	a0,sp@(FR_SP)		|   the user stack pointer
429	clrl	sp@-			| no VA arg
430	clrl	sp@-			| or code arg
431	movl	d0,sp@-			| push trap type
432	jbsr	_trap			| handle trap
433	lea	sp@(12),sp		| pop value args
434	movl	sp@(FR_SP),a0		| restore
435	movl	a0,usp			|   user SP
436	moveml	sp@+,#0x7FFF		| restore most user regs
437	addql	#8,sp			| pop SP and stack adjust
438	jra	rei			| all done
439
440	.globl	_straytrap
441_badtrap:
442	clrl	sp@-			| stack adjust count
443	moveml	#0xFFFF,sp@-		| save std frame regs
444	jbsr	_straytrap		| report
445	moveml	sp@+,#0xFFFF		| restore regs
446	addql	#4, sp			| stack adjust count
447	jra	rei			| all done
448
449/*
450 * Trap 0 is for system calls
451 */
452	.globl	_syscall
453_trap0:
454	clrl	sp@-			| stack adjust count
455	moveml	#0xFFFF,sp@-		| save user registers
456	movl	usp,a0			| save the user SP
457	movl	a0,sp@(FR_SP)		|   in the savearea
458	movl	d0,sp@-			| push syscall number
459	jbsr	_syscall		| handle it
460	addql	#4,sp			| pop syscall arg
461	movl	sp@(FR_SP),a0		| grab and restore
462	movl	a0,usp			|   user SP
463	moveml	sp@+,#0x7FFF		| restore most registers
464	addql	#8,sp			| pop SP and stack adjust
465	jra	rei			| all done
466
467/*
468 * Trap 1 action depends on the emulation type:
469 * NetBSD: sigreturn "syscall"
470 *   HPUX: user breakpoint
471 */
472_trap1:
473#if 0 /* COMPAT_HPUX */
474	/* If process is HPUX, this is a user breakpoint. */
475	jne	_trap15			| HPUX user breakpoint
476#endif
477	jra	sigreturn		| NetBSD
478
479/*
480 * Trap 2 action depends on the emulation type:
481 * NetBSD: user breakpoint -- See XXX below...
482 *  SunOS: cache flush
483 *   HPUX: sigreturn
484 */
485_trap2:
486#if 0 /* COMPAT_HPUX */
487	/* If process is HPUX, this is a sigreturn call */
488	jne	sigreturn
489#endif
490	jra	_trap15			| NetBSD user breakpoint
491| XXX - Make NetBSD use trap 15 for breakpoints?
492| XXX - That way, we can allow this cache flush...
493| XXX SunOS trap #2 (and NetBSD?)
494| Flush on-chip cache (leave it enabled)
495|	movl	#CACHE_CLR,d0
496|	movc	d0,cacr
497|	rte
498
499/*
500 * Trap 12 is the entry point for the cachectl "syscall"
501 *	cachectl(command, addr, length)
502 * command in d0, addr in a1, length in d1
503 */
504	.globl	_cachectl
505_trap12:
506	movl	d1,sp@-			| push length
507	movl	a1,sp@-			| push addr
508	movl	d0,sp@-			| push command
509	jbsr	_cachectl		| do it
510	lea	sp@(12),sp		| pop args
511	jra	rei			| all done
512
513/*
514 * Trace (single-step) trap.  Kernel-mode is special.
515 * User mode traps are simply passed on to trap().
516 */
517_trace:
518	clrl	sp@-			| stack adjust count
519	moveml	#0xFFFF,sp@-
520	moveq	#T_TRACE,d0
521	btst	#5,sp@(FR_HW)		| was supervisor mode?
522	jne	kbrkpt			|  yes, kernel brkpt
523	jra	fault			| no, user-mode fault
524
525/*
526 * Trap 15 is used for:
527 *	- GDB breakpoints (in user programs)
528 *	- KGDB breakpoints (in the kernel)
529 *	- trace traps for SUN binaries (not fully supported yet)
530 * User mode traps are simply passed to trap().
531 */
532_trap15:
533	clrl	sp@-			| stack adjust count
534	moveml	#0xFFFF,sp@-
535	moveq	#T_TRAP15,d0
536	btst	#5,sp@(FR_HW)		| was supervisor mode?
537	jne	kbrkpt			|  yes, kernel brkpt
538	jra	fault			| no, user-mode fault
539
540kbrkpt:
541	| Kernel-mode breakpoint or trace trap. (d0=trap_type)
542	| Save the system sp rather than the user sp.
543	movw	#PSL_HIGHIPL,sr		| lock out interrupts
544	lea	sp@(FR_SIZE),a6		| Save stack pointer
545	movl	a6,sp@(FR_SP)		|  from before trap
546
547	| If we are not on tmpstk switch to it.
548	| (so debugger can change the stack pointer)
549	movl	a6,d1
550	cmpl	#tmpstk,d1
551	jls	Lbrkpt2 		| already on tmpstk
552	| Copy frame to the temporary stack
553	movl	sp,a0			| a0=src
554	lea	tmpstk-96,a1		| a1=dst
555	movl	a1,sp			| sp=new frame
556	moveq	#FR_SIZE,d1
557Lbrkpt1:
558	movl	a0@+,a1@+
559	subql	#4,d1
560	bgt	Lbrkpt1
561
562Lbrkpt2:
563	| Call the trap handler for the kernel debugger.
564	| Do not call trap() to handle it, so that we can
565	| set breakpoints in trap() if we want.  We know
566	| the trap type is either T_TRACE or T_BREAKPOINT.
567	movl	d0,sp@-			| push trap type
568	jbsr	_trap_kdebug
569	addql	#4,sp			| pop args
570
571	| The stack pointer may have been modified, or
572	| data below it modified (by kgdb push call),
573	| so push the hardware frame at the current sp
574	| before restoring registers and returning.
575	movl	sp@(FR_SP),a0		| modified sp
576	lea	sp@(FR_SIZE),a1		| end of our frame
577	movl	a1@-,a0@-		| copy 2 longs with
578	movl	a1@-,a0@-		| ... predecrement
579	movl	a0,sp@(FR_SP)		| sp = h/w frame
580	moveml	sp@+,#0x7FFF		| restore all but sp
581	movl	sp@,sp			| ... and sp
582	rte				| all done
583
584/* Use common m68k sigreturn */
585#include <m68k/m68k/sigreturn.s>
586
587/*
588 * Interrupt handlers.  Most are auto-vectored,
589 * and hard-wired the same way on all sun3 models.
590 * Format in the stack is:
591 *   d0,d1,a0,a1, sr, pc, vo
592 */
593
594#define INTERRUPT_SAVEREG \
595	moveml	#0xC0C0,sp@-
596
597#define INTERRUPT_RESTORE \
598	moveml	sp@+,#0x0303
599
600/*
601 * This is the common auto-vector interrupt handler,
602 * for which the CPU provides the vector=0x18+level.
603 * These are installed in the interrupt vector table.
604 */
605	.align	2
606	.globl	__isr_autovec, _isr_autovec
607__isr_autovec:
608	INTERRUPT_SAVEREG
609	jbsr	_isr_autovec
610	INTERRUPT_RESTORE
611	jra	rei
612
613/* clock: see clock.c */
614	.align	2
615	.globl	__isr_clock, _clock_intr
616__isr_clock:
617	INTERRUPT_SAVEREG
618	jbsr	_clock_intr
619	INTERRUPT_RESTORE
620	jra	rei
621
622| Handler for all vectored interrupts (i.e. VME interrupts)
623	.align	2
624	.globl	__isr_vectored, _isr_vectored
625__isr_vectored:
626	INTERRUPT_SAVEREG
627	jbsr	_isr_vectored
628	INTERRUPT_RESTORE
629	jra	rei
630
631#undef	INTERRUPT_SAVEREG
632#undef	INTERRUPT_RESTORE
633
634/* interrupt counters (needed by vmstat) */
635	.globl	_intrcnt,_eintrcnt,_intrnames,_eintrnames
636_intrnames:
637	.asciz	"spur"	| 0
638	.asciz	"lev1"	| 1
639	.asciz	"lev2"	| 2
640	.asciz	"lev3"	| 3
641	.asciz	"lev4"	| 4
642	.asciz	"clock"	| 5
643	.asciz	"lev6"	| 6
644	.asciz	"nmi"	| 7
645_eintrnames:
646
647	.data
648	.even
649_intrcnt:
650	.long	0,0,0,0,0,0,0,0,0,0
651_eintrcnt:
652	.text
653
654/*
655 * Emulation of VAX REI instruction.
656 *
657 * This code is (mostly) un-altered from the hp300 code,
658 * except that sun machines do not need a simulated SIR
659 * because they have a real software interrupt register.
660 *
661 * This code deals with checking for and servicing ASTs
662 * (profiling, scheduling) and software interrupts (network, softclock).
663 * We check for ASTs first, just like the VAX.  To avoid excess overhead
664 * the T_ASTFLT handling code will also check for software interrupts so we
665 * do not have to do it here.  After identifying that we need an AST we
666 * drop the IPL to allow device interrupts.
667 *
668 * This code is complicated by the fact that sendsig may have been called
669 * necessitating a stack cleanup.
670 */
671
672	.globl	_astpending
673	.globl	rei
674rei:
675#ifdef	DIAGNOSTIC
676	tstl	_panicstr		| have we paniced?
677	jne	Ldorte			| yes, do not make matters worse
678#endif
679	tstl	_astpending		| AST pending?
680	jeq	Ldorte			| no, done
681Lrei1:
682	btst	#5,sp@			| yes, are we returning to user mode?
683	jne	Ldorte			| no, done
684	movw	#PSL_LOWIPL,sr		| lower SPL
685	clrl	sp@-			| stack adjust
686	moveml	#0xFFFF,sp@-		| save all registers
687	movl	usp,a1			| including
688	movl	a1,sp@(FR_SP)		|    the users SP
689	clrl	sp@-			| VA == none
690	clrl	sp@-			| code == none
691	movl	#T_ASTFLT,sp@-		| type == async system trap
692	jbsr	_trap			| go handle it
693	lea	sp@(12),sp		| pop value args
694	movl	sp@(FR_SP),a0		| restore user SP
695	movl	a0,usp			|   from save area
696	movw	sp@(FR_ADJ),d0		| need to adjust stack?
697	jne	Laststkadj		| yes, go to it
698	moveml	sp@+,#0x7FFF		| no, restore most user regs
699	addql	#8,sp			| toss SP and stack adjust
700	rte				| and do real RTE
701Laststkadj:
702	lea	sp@(FR_HW),a1		| pointer to HW frame
703	addql	#8,a1			| source pointer
704	movl	a1,a0			| source
705	addw	d0,a0			|  + hole size = dest pointer
706	movl	a1@-,a0@-		| copy
707	movl	a1@-,a0@-		|  8 bytes
708	movl	a0,sp@(FR_SP)		| new SSP
709	moveml	sp@+,#0x7FFF		| restore user registers
710	movl	sp@,sp			| and our SP
711Ldorte:
712	rte				| real return
713
714/*
715 * Initialization is at the beginning of this file, because the
716 * kernel entry point needs to be at zero for compatibility with
717 * the Sun boot loader.  This works on Sun machines because the
718 * interrupt vector table for reset is NOT at address zero.
719 * (The MMU has a "boot" bit that forces access to the PROM)
720 */
721
722/*
723 * Signal "trampoline" code (18 bytes).  Invoked from RTE setup by sendsig().
724 *
725 * Stack looks like:
726 *
727 *	sp+0 ->	signal number
728 *	sp+4	signal specific code
729 *	sp+8	pointer to signal context frame (scp)
730 *	sp+12	address of handler
731 *	sp+16	saved hardware state
732 *			.
733 *			.
734 *	scp+0->	beginning of signal context frame
735 */
736	.globl	_sigcode, _esigcode
737	.data
738	.align	2
739_sigcode:	/* Found at address: 0x0DFFffdc */
740	movl	sp@(12),a0		| signal handler addr	(4 bytes)
741	jsr	a0@			| call signal handler	(2 bytes)
742	addql	#4,sp			| pop signo		(2 bytes)
743	trap	#1			| special syscall entry	(2 bytes)
744	movl	d0,sp@(4)		| save errno		(4 bytes)
745	moveq	#1,d0			| syscall == exit	(2 bytes)
746	trap	#0			| exit(errno)		(2 bytes)
747	.align	2
748_esigcode:
749	.text
750
751/* XXX - hp300 still has icode here... */
752
753/*
754 * Primitives
755 */
756#include <machine/asm.h>
757
758/*
759 * Use common m68k support routines.
760 */
761#include <m68k/m68k/support.s>
762
763	.globl	_whichqs,_qs,_cnt,_panic
764	.globl	_curproc
765	.comm	_want_resched,4
766
767/*
768 * Use common m68k process manipulation routines.
769 */
770#include <m68k/m68k/proc_subr.s>
771
772| Message for Lbadsw panic
773Lsw0:
774	.asciz	"cpu_switch"
775	.even
776
777	.globl	_curpcb
778	.globl	_masterpaddr	| XXX compatibility (debuggers)
779	.data
780_masterpaddr:			| XXX compatibility (debuggers)
781_curpcb:
782	.long	0
783	.comm	nullpcb,SIZEOF_PCB
784	.text
785
786/*
787 * At exit of a process, do a cpu_switch for the last time.
788 * Switch to a safe stack and PCB, and deallocate the process's resources.
789 * The ipl is high enough to prevent the memory from being reallocated.
790 */
791ENTRY(switch_exit)
792	movl	sp@(4),a0		| struct proc *p
793	movl	#nullpcb,_curpcb	| save state into garbage pcb
794	lea	tmpstk,sp		| goto a tmp stack
795	movl	a0,sp@-			| pass proc ptr down
796
797	/* Free old process's u-area. */
798	movl	#USPACE,sp@-		| size of u-area
799	movl	a0@(P_ADDR),sp@-	| address of process's u-area
800	movl	_kernel_map,sp@-	| map it was allocated in
801	jbsr	_kmem_free		| deallocate it
802	lea	sp@(12),sp		| pop args
803
804	jra	_cpu_switch
805
806/*
807 * When no processes are on the runq, cpu_switch() branches to idle
808 * to wait for something to come ready.
809 */
810	.data
811	.globl _Idle_count
812_Idle_count:
813	.long	0
814	.text
815
816	.globl	Idle
817Lidle:
818	stop	#PSL_LOWIPL
819Idle:
820	movw	#PSL_HIGHIPL,sr
821	addql	#1, _Idle_count
822	tstl	_whichqs
823	jeq	Lidle
824	movw	#PSL_LOWIPL,sr
825	jra	Lsw1
826
827Lbadsw:
828	movl	#Lsw0,sp@-
829	jbsr	_panic
830	/*NOTREACHED*/
831
832/*
833 * cpu_switch()
834 * Hacked for sun3
835 * XXX - Arg 1 is a proc pointer (curproc) but this doesn't use it.
836 * XXX - Sould we use p->p_addr instead of curpcb? -gwr
837 */
838ENTRY(cpu_switch)
839	movl	_curpcb,a1		| current pcb
840	movw	sr,a1@(PCB_PS)		| save sr before changing ipl
841#ifdef notyet
842	movl	_curproc,sp@-		| remember last proc running
843#endif
844	clrl	_curproc
845
846Lsw1:
847	/*
848	 * Find the highest-priority queue that isn't empty,
849	 * then take the first proc from that queue.
850	 */
851	clrl	d0
852	lea	_whichqs,a0
853	movl	a0@,d1
854Lswchk:
855	btst	d0,d1
856	jne	Lswfnd
857	addqb	#1,d0
858	cmpb	#32,d0
859	jne	Lswchk
860	jra	Idle
861Lswfnd:
862	movw	#PSL_HIGHIPL,sr		| lock out interrupts
863	movl	a0@,d1			| and check again...
864	bclr	d0,d1
865	jeq	Lsw1			| proc moved, rescan
866	movl	d1,a0@			| update whichqs
867	moveq	#1,d1			| double check for higher priority
868	lsll	d0,d1			| process (which may have snuck in
869	subql	#1,d1			| while we were finding this one)
870	andl	a0@,d1
871	jeq	Lswok			| no one got in, continue
872	movl	a0@,d1
873	bset	d0,d1			| otherwise put this one back
874	movl	d1,a0@
875	jra	Lsw1			| and rescan
876Lswok:
877	movl	d0,d1
878	lslb	#3,d1			| convert queue number to index
879	addl	#_qs,d1			| locate queue (q)
880	movl	d1,a1
881	cmpl	a1@(P_FORW),a1		| anyone on queue?
882	jeq	Lbadsw			| no, panic
883	movl	a1@(P_FORW),a0		| p = q->p_forw
884	movl	a0@(P_FORW),a1@(P_FORW)	| q->p_forw = p->p_forw
885	movl	a0@(P_FORW),a1		| q = p->p_forw
886	movl	a0@(P_BACK),a1@(P_BACK)	| q->p_back = p->p_back
887	cmpl	a0@(P_FORW),d1		| anyone left on queue?
888	jeq	Lsw2			| no, skip
889	movl	_whichqs,d1
890	bset	d0,d1			| yes, reset bit
891	movl	d1,_whichqs
892Lsw2:
893	movl	a0,_curproc
894	clrl	_want_resched
895#ifdef notyet
896	movl	sp@+,a1			| XXX - Make this work!
897	cmpl	a0,a1			| switching to same proc?
898	jeq	Lswdone			| yes, skip save and restore
899#endif
900	/*
901	 * Save state of previous process in its pcb.
902	 */
903	movl	_curpcb,a1
904	moveml	#0xFCFC,a1@(PCB_REGS)	| save non-scratch registers
905	movl	usp,a2			| grab USP (a2 has been saved)
906	movl	a2,a1@(PCB_USP)		| and save it
907
908	tstl	_fputype		| Do we have an fpu?
909	jeq	Lswnofpsave		| No?  Then don't try save.
910	lea	a1@(PCB_FPCTX),a2	| pointer to FP save area
911	fsave	a2@			| save FP state
912	tstb	a2@			| null state frame?
913	jeq	Lswnofpsave		| yes, all done
914	fmovem	fp0-fp7,a2@(FPF_REGS)		| save FP general regs
915	fmovem	fpcr/fpsr/fpi,a2@(FPF_FPCR)	| save FP control regs
916Lswnofpsave:
917
918	/*
919	 * Now that we have saved all the registers that must be
920	 * preserved, we are free to use those registers until
921	 * we load the registers for the switched-to process.
922	 * In this section, keep:  a0=curproc, a1=curpcb
923	 */
924
925#ifdef DIAGNOSTIC
926	tstl	a0@(P_WCHAN)
927	jne	Lbadsw
928	cmpb	#SRUN,a0@(P_STAT)
929	jne	Lbadsw
930#endif
931	clrl	a0@(P_BACK)		| clear back link
932	movl	a0@(P_ADDR),a1		| get p_addr
933	movl	a1,_curpcb
934
935	/*
936	 * Load the new VM context (new MMU root pointer)
937	 */
938	movl	a0@(P_VMSPACE),a2	| vm = p->p_vmspace
939#ifdef DIAGNOSTIC
940	tstl	a2			| map == VM_MAP_NULL?
941	jeq	Lbadsw			| panic
942#endif
943#ifdef PMAP_DEBUG
944	/*
945	 * Just call pmap_activate() for now.  Later on,
946	 * use the in-line version below (for speed).
947	 */
948	lea	a2@(VM_PMAP),a2 	| pmap = &vmspace.vm_pmap
949	pea	a2@			| push pmap
950	jbsr	_pmap_activate		| pmap_activate(pmap)
951	addql	#4,sp
952	movl	_curpcb,a1		| restore p_addr
953#else
954	/* XXX - Later, use this inline version. */
955	/* Just load the new CPU Root Pointer (MMU) */
956	lea	_kernel_crp, a3		| our CPU Root Ptr. (CRP)
957	lea	a2@(VM_PMAP),a2 	| pmap = &vmspace.vm_pmap
958	movl	a2@(PM_A_PHYS),d0	| phys = pmap->pm_a_phys
959	cmpl	a3@(4),d0		|  == kernel_crp.rp_addr ?
960	jeq	Lsame_mmuctx		| skip loadcrp/flush
961	/* OK, it is a new MMU context.  Load it up. */
962	movl	d0,a3@(4)
963	movl	#CACHE_CLR,d0
964	movc	d0,cacr			| invalidate cache(s)
965	pflusha				| flush entire TLB
966	pmove	a3@,crp			| load new user root pointer
967Lsame_mmuctx:
968#endif
969
970	/*
971	 * Reload the registers for the new process.
972	 * After this point we can only use d0,d1,a0,a1
973	 */
974	moveml	a1@(PCB_REGS),#0xFCFC	| reload registers
975	movl	a1@(PCB_USP),a0
976	movl	a0,usp			| and USP
977
978	tstl	_fputype		| If we don't have an fpu,
979	jeq	Lres_skip		|  don't try to restore it.
980	lea	a1@(PCB_FPCTX),a0	| pointer to FP save area
981	tstb	a0@			| null state frame?
982	jeq	Lresfprest		| yes, easy
983	fmovem	a0@(FPF_FPCR),fpcr/fpsr/fpi	| restore FP control regs
984	fmovem	a0@(FPF_REGS),fp0-fp7		| restore FP general regs
985Lresfprest:
986	frestore a0@			| restore state
987Lres_skip:
988	movw	a1@(PCB_PS),d0		| no, restore PS
989#ifdef DIAGNOSTIC
990	btst	#13,d0			| supervisor mode?
991	jeq	Lbadsw			| no? panic!
992#endif
993	movw	d0,sr			| OK, restore PS
994	moveq	#1,d0			| return 1 (for alternate returns)
995	rts
996
997/*
998 * savectx(pcb)
999 * Update pcb, saving current processor state.
1000 */
1001ENTRY(savectx)
1002	movl	sp@(4),a1
1003	movw	sr,a1@(PCB_PS)
1004	movl	usp,a0			| grab USP
1005	movl	a0,a1@(PCB_USP)		| and save it
1006	moveml	#0xFCFC,a1@(PCB_REGS)	| save non-scratch registers
1007
1008	tstl	_fputype		| Do we have FPU?
1009	jeq	Lsavedone		| No?  Then don't save state.
1010	lea	a1@(PCB_FPCTX),a0	| pointer to FP save area
1011	fsave	a0@			| save FP state
1012	tstb	a0@			| null state frame?
1013	jeq	Lsavedone		| yes, all done
1014	fmovem	fp0-fp7,a0@(FPF_REGS)		| save FP general regs
1015	fmovem	fpcr/fpsr/fpi,a0@(FPF_FPCR)	| save FP control regs
1016Lsavedone:
1017	moveq	#0,d0			| return 0
1018	rts
1019
1020/* suline() `040 only */
1021
1022#ifdef DEBUG
1023	.data
1024	.globl	fulltflush, fullcflush
1025fulltflush:
1026	.long	0
1027fullcflush:
1028	.long	0
1029	.text
1030#endif
1031
1032/*
1033 * Invalidate entire TLB.
1034 */
1035ENTRY(TBIA)
1036__TBIA:
1037	pflusha
1038	movl	#DC_CLEAR,d0
1039	movc	d0,cacr			| invalidate on-chip d-cache
1040	rts
1041
1042/*
1043 * Invalidate any TLB entry for given VA (TB Invalidate Single)
1044 */
1045ENTRY(TBIS)
1046#ifdef DEBUG
1047	tstl	fulltflush		| being conservative?
1048	jne	__TBIA			| yes, flush entire TLB
1049#endif
1050	movl	sp@(4),a0
1051	pflush	#0,#0,a0@		| flush address from both sides
1052	movl	#DC_CLEAR,d0
1053	movc	d0,cacr			| invalidate on-chip data cache
1054	rts
1055
1056/*
1057 * Invalidate supervisor side of TLB
1058 */
1059ENTRY(TBIAS)
1060#ifdef DEBUG
1061	tstl	fulltflush		| being conservative?
1062	jne	__TBIA			| yes, flush everything
1063#endif
1064	pflush	#4,#4			| flush supervisor TLB entries
1065	movl	#DC_CLEAR,d0
1066	movc	d0,cacr			| invalidate on-chip d-cache
1067	rts
1068
1069/*
1070 * Invalidate user side of TLB
1071 */
1072ENTRY(TBIAU)
1073#ifdef DEBUG
1074	tstl	fulltflush		| being conservative?
1075	jne	__TBIA			| yes, flush everything
1076#endif
1077	pflush	#0,#4			| flush user TLB entries
1078	movl	#DC_CLEAR,d0
1079	movc	d0,cacr			| invalidate on-chip d-cache
1080	rts
1081
1082/*
1083 * Invalidate instruction cache
1084 */
1085ENTRY(ICIA)
1086	movl	#IC_CLEAR,d0
1087	movc	d0,cacr			| invalidate i-cache
1088	rts
1089
1090/*
1091 * Invalidate data cache.
1092 * NOTE: we do not flush 68030 on-chip cache as there are no aliasing
1093 * problems with DC_WA.  The only cases we have to worry about are context
1094 * switch and TLB changes, both of which are handled "in-line" in resume
1095 * and TBI*.
1096 */
1097ENTRY(DCIA)
1098__DCIA:
1099	rts
1100
1101ENTRY(DCIS)
1102__DCIS:
1103	rts
1104
1105/*
1106 * Invalidate data cache.
1107 */
1108ENTRY(DCIU)
1109	movl	#DC_CLEAR,d0
1110	movc	d0,cacr			| invalidate on-chip d-cache
1111	rts
1112
1113/* ICPL, ICPP, DCPL, DCPP, DCPA, DCFL, DCFP */
1114
1115ENTRY(PCIA)
1116	movl	#DC_CLEAR,d0
1117	movc	d0,cacr			| invalidate on-chip d-cache
1118	rts
1119
1120ENTRY(ecacheon)
1121	rts
1122
1123ENTRY(ecacheoff)
1124	rts
1125
1126/*
1127 * Get callers current SP value.
1128 * Note that simply taking the address of a local variable in a C function
1129 * doesn't work because callee saved registers may be outside the stack frame
1130 * defined by A6 (e.g. GCC generated code).
1131 *
1132 * [I don't think the ENTRY() macro will do the right thing with this -- glass]
1133 */
1134	.globl	_getsp
1135_getsp:
1136	movl	sp,d0			| get current SP
1137	addql	#4,d0			| compensate for return address
1138	rts
1139
1140ENTRY(getsfc)
1141	movc	sfc,d0
1142	rts
1143
1144ENTRY(getdfc)
1145	movc	dfc,d0
1146	rts
1147
1148ENTRY(getvbr)
1149	movc vbr, d0
1150	rts
1151
1152ENTRY(setvbr)
1153	movl sp@(4), d0
1154	movc d0, vbr
1155	rts
1156
1157/*
1158 * Load a new CPU Root Pointer (CRP) into the MMU.
1159 *	void	loadcrp(struct mmu_rootptr *);
1160 */
1161ENTRY(loadcrp)
1162	movl	sp@(4),a0		| arg1: &CRP
1163	movl	#CACHE_CLR,d0
1164	movc	d0,cacr			| invalidate cache(s)
1165	pflusha				| flush entire TLB
1166	pmove	a0@,crp			| load new user root pointer
1167	rts
1168
1169/*
1170 * Get the physical address of the PTE for a given VA.
1171 */
1172ENTRY(ptest_addr)
1173	movl	sp@(4),a0		| VA
1174	ptestr	#5,a0@,#7,a1		| a1 = addr of PTE
1175	movl	a1,d0
1176	rts
1177
1178/*
1179 * Set processor priority level calls.  Most are implemented with
1180 * inline asm expansions.  However, we need one instantiation here
1181 * in case some non-optimized code makes external references.
1182 * Most places will use the inlined function param.h supplies.
1183 */
1184
1185ENTRY(_spl)
1186	movl	sp@(4),d1
1187	clrl	d0
1188	movw	sr,d0
1189	movw	d1,sr
1190	rts
1191
1192ENTRY(getsr)
1193	moveq	#0, d0
1194	movw	sr, d0
1195	rts
1196
1197/*
1198 * Save and restore 68881 state.
1199 */
1200ENTRY(m68881_save)
1201	movl	sp@(4),a0		| save area pointer
1202	fsave	a0@			| save state
1203	tstb	a0@			| null state frame?
1204	jeq	Lm68881sdone		| yes, all done
1205	fmovem fp0-fp7,a0@(FPF_REGS)		| save FP general regs
1206	fmovem fpcr/fpsr/fpi,a0@(FPF_FPCR)	| save FP control regs
1207Lm68881sdone:
1208	rts
1209
1210ENTRY(m68881_restore)
1211	movl	sp@(4),a0		| save area pointer
1212	tstb	a0@			| null state frame?
1213	jeq	Lm68881rdone		| yes, easy
1214	fmovem	a0@(FPF_FPCR),fpcr/fpsr/fpi	| restore FP control regs
1215	fmovem	a0@(FPF_REGS),fp0-fp7		| restore FP general regs
1216Lm68881rdone:
1217	frestore a0@			| restore state
1218	rts
1219
1220/*
1221 * _delay(unsigned N)
1222 * Delay for at least (N/256) microseconds.
1223 * This routine depends on the variable:  delay_divisor
1224 * which should be set based on the CPU clock rate.
1225 * XXX: Currently this is set in sun3_startup.c based on the
1226 * XXX: CPU model but this should be determined at run time...
1227 */
1228	.globl	__delay
1229__delay:
1230	| d0 = arg = (usecs << 8)
1231	movl	sp@(4),d0
1232	| d1 = delay_divisor;
1233	movl	_delay_divisor,d1
1234L_delay:
1235	subl	d1,d0
1236	jgt	L_delay
1237	rts
1238
1239
1240| Define some addresses, mostly so DDB can print useful info.
1241	.globl	_kernbase
1242	.set	_kernbase,KERNBASE
1243	.globl	_dvma_base
1244	.set	_dvma_base,DVMA_SPACE_START
1245	.globl	_prom_start
1246	.set	_prom_start,MONSTART
1247	.globl	_prom_base
1248	.set	_prom_base,PROM_BASE
1249
1250|The end!
1251