xref: /linux/arch/parisc/kernel/entry.S (revision 834f0c353ae430c1a6ce023c9b77bbd3ff9241a7)
1/*
2 * Linux/PA-RISC Project (http://www.parisc-linux.org/)
3 *
4 * kernel entry points (interruptions, system call wrappers)
5 *  Copyright (C) 1999,2000 Philipp Rumpf
6 *  Copyright (C) 1999 SuSE GmbH Nuernberg
7 *  Copyright (C) 2000 Hewlett-Packard (John Marvin)
8 *  Copyright (C) 1999 Hewlett-Packard (Frank Rowand)
9 *
10 *    This program is free software; you can redistribute it and/or modify
11 *    it under the terms of the GNU General Public License as published by
12 *    the Free Software Foundation; either version 2, or (at your option)
13 *    any later version.
14 *
15 *    This program is distributed in the hope that it will be useful,
16 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
17 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18 *    GNU General Public License for more details.
19 *
20 *    You should have received a copy of the GNU General Public License
21 *    along with this program; if not, write to the Free Software
22 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
23 */
24
25#include <asm/asm-offsets.h>
26
27/* we have the following possibilities to act on an interruption:
28 *  - handle in assembly and use shadowed registers only
29 *  - save registers to kernel stack and handle in assembly or C */
30
31
32#include <asm/psw.h>
33#include <asm/cache.h>		/* for L1_CACHE_SHIFT */
34#include <asm/assembly.h>	/* for LDREG/STREG defines */
35#include <asm/pgtable.h>
36#include <asm/signal.h>
37#include <asm/unistd.h>
38#include <asm/thread_info.h>
39
40#include <linux/linkage.h>
41
42#ifdef CONFIG_64BIT
43	.level 2.0w
44#else
45	.level 2.0
46#endif
47
48	.import         pa_dbit_lock,data
49
50	/* space_to_prot macro creates a prot id from a space id */
51
52#if (SPACEID_SHIFT) == 0
53	.macro  space_to_prot spc prot
54	depd,z  \spc,62,31,\prot
55	.endm
56#else
57	.macro  space_to_prot spc prot
58	extrd,u \spc,(64 - (SPACEID_SHIFT)),32,\prot
59	.endm
60#endif
61
62	/* Switch to virtual mapping, trashing only %r1 */
63	.macro  virt_map
64	/* pcxt_ssm_bug */
65	rsm	PSW_SM_I, %r0	/* barrier for "Relied upon Translation */
66	mtsp	%r0, %sr4
67	mtsp	%r0, %sr5
68	mfsp	%sr7, %r1
69	or,=    %r0,%r1,%r0	/* Only save sr7 in sr3 if sr7 != 0 */
70	mtsp	%r1, %sr3
71	tovirt_r1 %r29
72	load32	KERNEL_PSW, %r1
73
74	rsm     PSW_SM_QUIET,%r0	/* second "heavy weight" ctl op */
75	mtsp	%r0, %sr6
76	mtsp	%r0, %sr7
77	mtctl	%r0, %cr17	/* Clear IIASQ tail */
78	mtctl	%r0, %cr17	/* Clear IIASQ head */
79	mtctl	%r1, %ipsw
80	load32	4f, %r1
81	mtctl	%r1, %cr18	/* Set IIAOQ tail */
82	ldo	4(%r1), %r1
83	mtctl	%r1, %cr18	/* Set IIAOQ head */
84	rfir
85	nop
864:
87	.endm
88
89	/*
90	 * The "get_stack" macros are responsible for determining the
91	 * kernel stack value.
92	 *
93	 *      If sr7 == 0
94	 *          Already using a kernel stack, so call the
95	 *          get_stack_use_r30 macro to push a pt_regs structure
96	 *          on the stack, and store registers there.
97	 *      else
98	 *          Need to set up a kernel stack, so call the
99	 *          get_stack_use_cr30 macro to set up a pointer
100	 *          to the pt_regs structure contained within the
101	 *          task pointer pointed to by cr30. Set the stack
102	 *          pointer to point to the end of the task structure.
103	 *
104	 * Note that we use shadowed registers for temps until
105	 * we can save %r26 and %r29. %r26 is used to preserve
106	 * %r8 (a shadowed register) which temporarily contained
107	 * either the fault type ("code") or the eirr. We need
108	 * to use a non-shadowed register to carry the value over
109	 * the rfir in virt_map. We use %r26 since this value winds
110	 * up being passed as the argument to either do_cpu_irq_mask
111	 * or handle_interruption. %r29 is used to hold a pointer
112	 * the register save area, and once again, it needs to
113	 * be a non-shadowed register so that it survives the rfir.
114	 *
115	 * N.B. TASK_SZ_ALGN and PT_SZ_ALGN include space for a stack frame.
116	 */
117
118	.macro  get_stack_use_cr30
119
120	/* we save the registers in the task struct */
121
122	mfctl   %cr30, %r1
123	tophys  %r1,%r9
124	LDREG	TI_TASK(%r9), %r1	/* thread_info -> task_struct */
125	tophys  %r1,%r9
126	ldo     TASK_REGS(%r9),%r9
127	STREG   %r30, PT_GR30(%r9)
128	STREG   %r29,PT_GR29(%r9)
129	STREG   %r26,PT_GR26(%r9)
130	copy    %r9,%r29
131	mfctl   %cr30, %r1
132	ldo	THREAD_SZ_ALGN(%r1), %r30
133	.endm
134
135	.macro  get_stack_use_r30
136
137	/* we put a struct pt_regs on the stack and save the registers there */
138
139	tophys  %r30,%r9
140	STREG   %r30,PT_GR30(%r9)
141	ldo	PT_SZ_ALGN(%r30),%r30
142	STREG   %r29,PT_GR29(%r9)
143	STREG   %r26,PT_GR26(%r9)
144	copy    %r9,%r29
145	.endm
146
147	.macro  rest_stack
148	LDREG   PT_GR1(%r29), %r1
149	LDREG   PT_GR30(%r29),%r30
150	LDREG   PT_GR29(%r29),%r29
151	.endm
152
153	/* default interruption handler
154	 * (calls traps.c:handle_interruption) */
155	.macro	def code
156	b	intr_save
157	ldi     \code, %r8
158	.align	32
159	.endm
160
161	/* Interrupt interruption handler
162	 * (calls irq.c:do_cpu_irq_mask) */
163	.macro	extint code
164	b	intr_extint
165	mfsp    %sr7,%r16
166	.align	32
167	.endm
168
169	.import	os_hpmc, code
170
171	/* HPMC handler */
172	.macro	hpmc code
173	nop			/* must be a NOP, will be patched later */
174	load32	PA(os_hpmc), %r3
175	bv,n	0(%r3)
176	nop
177	.word	0		/* checksum (will be patched) */
178	.word	PA(os_hpmc)	/* address of handler */
179	.word	0		/* length of handler */
180	.endm
181
182	/*
183	 * Performance Note: Instructions will be moved up into
184	 * this part of the code later on, once we are sure
185	 * that the tlb miss handlers are close to final form.
186	 */
187
188	/* Register definitions for tlb miss handler macros */
189
190	va  = r8	/* virtual address for which the trap occurred */
191	spc = r24	/* space for which the trap occurred */
192
193#ifndef CONFIG_64BIT
194
195	/*
196	 * itlb miss interruption handler (parisc 1.1 - 32 bit)
197	 */
198
199	.macro	itlb_11 code
200
201	mfctl	%pcsq, spc
202	b	itlb_miss_11
203	mfctl	%pcoq, va
204
205	.align		32
206	.endm
207#endif
208
209	/*
210	 * itlb miss interruption handler (parisc 2.0)
211	 */
212
213	.macro	itlb_20 code
214	mfctl	%pcsq, spc
215#ifdef CONFIG_64BIT
216	b       itlb_miss_20w
217#else
218	b	itlb_miss_20
219#endif
220	mfctl	%pcoq, va
221
222	.align		32
223	.endm
224
225#ifndef CONFIG_64BIT
226	/*
227	 * naitlb miss interruption handler (parisc 1.1 - 32 bit)
228	 */
229
230	.macro	naitlb_11 code
231
232	mfctl	%isr,spc
233	b	naitlb_miss_11
234	mfctl 	%ior,va
235
236	.align		32
237	.endm
238#endif
239
240	/*
241	 * naitlb miss interruption handler (parisc 2.0)
242	 */
243
244	.macro	naitlb_20 code
245
246	mfctl	%isr,spc
247#ifdef CONFIG_64BIT
248	b       naitlb_miss_20w
249#else
250	b	naitlb_miss_20
251#endif
252	mfctl 	%ior,va
253
254	.align		32
255	.endm
256
257#ifndef CONFIG_64BIT
258	/*
259	 * dtlb miss interruption handler (parisc 1.1 - 32 bit)
260	 */
261
262	.macro	dtlb_11 code
263
264	mfctl	%isr, spc
265	b	dtlb_miss_11
266	mfctl	%ior, va
267
268	.align		32
269	.endm
270#endif
271
272	/*
273	 * dtlb miss interruption handler (parisc 2.0)
274	 */
275
276	.macro	dtlb_20 code
277
278	mfctl	%isr, spc
279#ifdef CONFIG_64BIT
280	b       dtlb_miss_20w
281#else
282	b	dtlb_miss_20
283#endif
284	mfctl	%ior, va
285
286	.align		32
287	.endm
288
289#ifndef CONFIG_64BIT
290	/* nadtlb miss interruption handler (parisc 1.1 - 32 bit) */
291
292	.macro	nadtlb_11 code
293
294	mfctl	%isr,spc
295	b       nadtlb_miss_11
296	mfctl	%ior,va
297
298	.align		32
299	.endm
300#endif
301
302	/* nadtlb miss interruption handler (parisc 2.0) */
303
304	.macro	nadtlb_20 code
305
306	mfctl	%isr,spc
307#ifdef CONFIG_64BIT
308	b       nadtlb_miss_20w
309#else
310	b       nadtlb_miss_20
311#endif
312	mfctl	%ior,va
313
314	.align		32
315	.endm
316
317#ifndef CONFIG_64BIT
318	/*
319	 * dirty bit trap interruption handler (parisc 1.1 - 32 bit)
320	 */
321
322	.macro	dbit_11 code
323
324	mfctl	%isr,spc
325	b	dbit_trap_11
326	mfctl	%ior,va
327
328	.align		32
329	.endm
330#endif
331
332	/*
333	 * dirty bit trap interruption handler (parisc 2.0)
334	 */
335
336	.macro	dbit_20 code
337
338	mfctl	%isr,spc
339#ifdef CONFIG_64BIT
340	b       dbit_trap_20w
341#else
342	b	dbit_trap_20
343#endif
344	mfctl	%ior,va
345
346	.align		32
347	.endm
348
349	/* In LP64, the space contains part of the upper 32 bits of the
350	 * fault.  We have to extract this and place it in the va,
351	 * zeroing the corresponding bits in the space register */
352	.macro		space_adjust	spc,va,tmp
353#ifdef CONFIG_64BIT
354	extrd,u		\spc,63,SPACEID_SHIFT,\tmp
355	depd		%r0,63,SPACEID_SHIFT,\spc
356	depd		\tmp,31,SPACEID_SHIFT,\va
357#endif
358	.endm
359
360	.import		swapper_pg_dir,code
361
362	/* Get the pgd.  For faults on space zero (kernel space), this
363	 * is simply swapper_pg_dir.  For user space faults, the
364	 * pgd is stored in %cr25 */
365	.macro		get_pgd		spc,reg
366	ldil		L%PA(swapper_pg_dir),\reg
367	ldo		R%PA(swapper_pg_dir)(\reg),\reg
368	or,COND(=)	%r0,\spc,%r0
369	mfctl		%cr25,\reg
370	.endm
371
372	/*
373		space_check(spc,tmp,fault)
374
375		spc - The space we saw the fault with.
376		tmp - The place to store the current space.
377		fault - Function to call on failure.
378
379		Only allow faults on different spaces from the
380		currently active one if we're the kernel
381
382	*/
383	.macro		space_check	spc,tmp,fault
384	mfsp		%sr7,\tmp
385	or,COND(<>)	%r0,\spc,%r0	/* user may execute gateway page
386					 * as kernel, so defeat the space
387					 * check if it is */
388	copy		\spc,\tmp
389	or,COND(=)	%r0,\tmp,%r0	/* nullify if executing as kernel */
390	cmpb,COND(<>),n	\tmp,\spc,\fault
391	.endm
392
393	/* Look up a PTE in a 2-Level scheme (faulting at each
394	 * level if the entry isn't present
395	 *
396	 * NOTE: we use ldw even for LP64, since the short pointers
397	 * can address up to 1TB
398	 */
399	.macro		L2_ptep	pmd,pte,index,va,fault
400#if PT_NLEVELS == 3
401	extru		\va,31-ASM_PMD_SHIFT,ASM_BITS_PER_PMD,\index
402#else
403	extru		\va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
404#endif
405	dep             %r0,31,PAGE_SHIFT,\pmd  /* clear offset */
406	copy		%r0,\pte
407	ldw,s		\index(\pmd),\pmd
408	bb,>=,n		\pmd,_PxD_PRESENT_BIT,\fault
409	dep		%r0,31,PxD_FLAG_SHIFT,\pmd /* clear flags */
410	copy		\pmd,%r9
411	SHLREG		%r9,PxD_VALUE_SHIFT,\pmd
412	extru		\va,31-PAGE_SHIFT,ASM_BITS_PER_PTE,\index
413	dep		%r0,31,PAGE_SHIFT,\pmd  /* clear offset */
414	shladd		\index,BITS_PER_PTE_ENTRY,\pmd,\pmd
415	LDREG		%r0(\pmd),\pte		/* pmd is now pte */
416	bb,>=,n		\pte,_PAGE_PRESENT_BIT,\fault
417	.endm
418
419	/* Look up PTE in a 3-Level scheme.
420	 *
421	 * Here we implement a Hybrid L2/L3 scheme: we allocate the
422	 * first pmd adjacent to the pgd.  This means that we can
423	 * subtract a constant offset to get to it.  The pmd and pgd
424	 * sizes are arranged so that a single pmd covers 4GB (giving
425	 * a full LP64 process access to 8TB) so our lookups are
426	 * effectively L2 for the first 4GB of the kernel (i.e. for
427	 * all ILP32 processes and all the kernel for machines with
428	 * under 4GB of memory) */
429	.macro		L3_ptep pgd,pte,index,va,fault
430#if PT_NLEVELS == 3 /* we might have a 2-Level scheme, e.g. with 16kb page size */
431	extrd,u		\va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
432	copy		%r0,\pte
433	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
434	ldw,s		\index(\pgd),\pgd
435	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
436	bb,>=,n		\pgd,_PxD_PRESENT_BIT,\fault
437	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
438	shld		\pgd,PxD_VALUE_SHIFT,\index
439	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
440	copy		\index,\pgd
441	extrd,u,*<>	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
442	ldo		ASM_PGD_PMD_OFFSET(\pgd),\pgd
443#endif
444	L2_ptep		\pgd,\pte,\index,\va,\fault
445	.endm
446
447	/* Set the _PAGE_ACCESSED bit of the PTE.  Be clever and
448	 * don't needlessly dirty the cache line if it was already set */
449	.macro		update_ptep	ptep,pte,tmp,tmp1
450	ldi		_PAGE_ACCESSED,\tmp1
451	or		\tmp1,\pte,\tmp
452	and,COND(<>)	\tmp1,\pte,%r0
453	STREG		\tmp,0(\ptep)
454	.endm
455
456	/* Set the dirty bit (and accessed bit).  No need to be
457	 * clever, this is only used from the dirty fault */
458	.macro		update_dirty	ptep,pte,tmp
459	ldi		_PAGE_ACCESSED|_PAGE_DIRTY,\tmp
460	or		\tmp,\pte,\pte
461	STREG		\pte,0(\ptep)
462	.endm
463
464	/* bitshift difference between a PFN (based on kernel's PAGE_SIZE)
465	 * to a CPU TLB 4k PFN (4k => 12 bits to shift) */
466	#define PAGE_ADD_SHIFT  (PAGE_SHIFT-12)
467
468	/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
469	.macro		convert_for_tlb_insert20 pte
470	extrd,u		\pte,(63-ASM_PFN_PTE_SHIFT)+(63-58)+PAGE_ADD_SHIFT,\
471				64-PAGE_SHIFT-PAGE_ADD_SHIFT,\pte
472	depdi		_PAGE_SIZE_ENCODING_DEFAULT,63,\
473				(63-58)+PAGE_ADD_SHIFT,\pte
474	.endm
475
476	/* Convert the pte and prot to tlb insertion values.  How
477	 * this happens is quite subtle, read below */
478	.macro		make_insert_tlb	spc,pte,prot
479	space_to_prot   \spc \prot        /* create prot id from space */
480	/* The following is the real subtlety.  This is depositing
481	 * T <-> _PAGE_REFTRAP
482	 * D <-> _PAGE_DIRTY
483	 * B <-> _PAGE_DMB (memory break)
484	 *
485	 * Then incredible subtlety: The access rights are
486	 * _PAGE_GATEWAY _PAGE_EXEC _PAGE_READ
487	 * See 3-14 of the parisc 2.0 manual
488	 *
489	 * Finally, _PAGE_READ goes in the top bit of PL1 (so we
490	 * trigger an access rights trap in user space if the user
491	 * tries to read an unreadable page */
492	depd            \pte,8,7,\prot
493
494	/* PAGE_USER indicates the page can be read with user privileges,
495	 * so deposit X1|11 to PL1|PL2 (remember the upper bit of PL1
496	 * contains _PAGE_READ */
497	extrd,u,*=      \pte,_PAGE_USER_BIT+32,1,%r0
498	depdi		7,11,3,\prot
499	/* If we're a gateway page, drop PL2 back to zero for promotion
500	 * to kernel privilege (so we can execute the page as kernel).
501	 * Any privilege promotion page always denys read and write */
502	extrd,u,*= 	\pte,_PAGE_GATEWAY_BIT+32,1,%r0
503	depd		%r0,11,2,\prot	/* If Gateway, Set PL2 to 0 */
504
505	/* Enforce uncacheable pages.
506	 * This should ONLY be use for MMIO on PA 2.0 machines.
507	 * Memory/DMA is cache coherent on all PA2.0 machines we support
508	 * (that means T-class is NOT supported) and the memory controllers
509	 * on most of those machines only handles cache transactions.
510	 */
511	extrd,u,*=	\pte,_PAGE_NO_CACHE_BIT+32,1,%r0
512	depdi		1,12,1,\prot
513
514	/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
515	convert_for_tlb_insert20 \pte
516	.endm
517
518	/* Identical macro to make_insert_tlb above, except it
519	 * makes the tlb entry for the differently formatted pa11
520	 * insertion instructions */
521	.macro		make_insert_tlb_11	spc,pte,prot
522	zdep		\spc,30,15,\prot
523	dep		\pte,8,7,\prot
524	extru,=		\pte,_PAGE_NO_CACHE_BIT,1,%r0
525	depi		1,12,1,\prot
526	extru,=         \pte,_PAGE_USER_BIT,1,%r0
527	depi		7,11,3,\prot   /* Set for user space (1 rsvd for read) */
528	extru,= 	\pte,_PAGE_GATEWAY_BIT,1,%r0
529	depi		0,11,2,\prot	/* If Gateway, Set PL2 to 0 */
530
531	/* Get rid of prot bits and convert to page addr for iitlba */
532
533	depi		0,31,ASM_PFN_PTE_SHIFT,\pte
534	SHRREG		\pte,(ASM_PFN_PTE_SHIFT-(31-26)),\pte
535	.endm
536
537	/* This is for ILP32 PA2.0 only.  The TLB insertion needs
538	 * to extend into I/O space if the address is 0xfXXXXXXX
539	 * so we extend the f's into the top word of the pte in
540	 * this case */
541	.macro		f_extend	pte,tmp
542	extrd,s		\pte,42,4,\tmp
543	addi,<>		1,\tmp,%r0
544	extrd,s		\pte,63,25,\pte
545	.endm
546
547	/* The alias region is an 8MB aligned 16MB to do clear and
548	 * copy user pages at addresses congruent with the user
549	 * virtual address.
550	 *
551	 * To use the alias page, you set %r26 up with the to TLB
552	 * entry (identifying the physical page) and %r23 up with
553	 * the from tlb entry (or nothing if only a to entry---for
554	 * clear_user_page_asm) */
555	.macro		do_alias	spc,tmp,tmp1,va,pte,prot,fault
556	cmpib,COND(<>),n 0,\spc,\fault
557	ldil		L%(TMPALIAS_MAP_START),\tmp
558#if defined(CONFIG_64BIT) && (TMPALIAS_MAP_START >= 0x80000000)
559	/* on LP64, ldi will sign extend into the upper 32 bits,
560	 * which is behaviour we don't want */
561	depdi		0,31,32,\tmp
562#endif
563	copy		\va,\tmp1
564	depi		0,31,23,\tmp1
565	cmpb,COND(<>),n	\tmp,\tmp1,\fault
566	mfctl		%cr19,\tmp	/* iir */
567	/* get the opcode (first six bits) into \tmp */
568	extrw,u		\tmp,5,6,\tmp
569	/*
570	 * Only setting the T bit prevents data cache movein
571	 * Setting access rights to zero prevents instruction cache movein
572	 *
573	 * Note subtlety here: _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE go
574	 * to type field and _PAGE_READ goes to top bit of PL1
575	 */
576	ldi		(_PAGE_REFTRAP|_PAGE_READ|_PAGE_WRITE),\prot
577	/*
578	 * so if the opcode is one (i.e. this is a memory management
579	 * instruction) nullify the next load so \prot is only T.
580	 * Otherwise this is a normal data operation
581	 */
582	cmpiclr,=	0x01,\tmp,%r0
583	ldi		(_PAGE_DIRTY|_PAGE_READ|_PAGE_WRITE),\prot
584	depd,z		\prot,8,7,\prot
585	/*
586	 * OK, it is in the temp alias region, check whether "from" or "to".
587	 * Check "subtle" note in pacache.S re: r23/r26.
588	 */
589#ifdef CONFIG_64BIT
590	extrd,u,*=	\va,41,1,%r0
591#else
592	extrw,u,=	\va,9,1,%r0
593#endif
594	or,COND(tr)	%r23,%r0,\pte
595	or		%r26,%r0,\pte
596	.endm
597
598
599	/*
600	 * Align fault_vector_20 on 4K boundary so that both
601	 * fault_vector_11 and fault_vector_20 are on the
602	 * same page. This is only necessary as long as we
603	 * write protect the kernel text, which we may stop
604	 * doing once we use large page translations to cover
605	 * the static part of the kernel address space.
606	 */
607
608	.text
609
610	.align	PAGE_SIZE
611
612ENTRY(fault_vector_20)
613	/* First vector is invalid (0) */
614	.ascii	"cows can fly"
615	.byte 0
616	.align 32
617
618	hpmc		 1
619	def		 2
620	def		 3
621	extint		 4
622	def		 5
623	itlb_20		 6
624	def		 7
625	def		 8
626	def              9
627	def		10
628	def		11
629	def		12
630	def		13
631	def		14
632	dtlb_20		15
633	naitlb_20	16
634	nadtlb_20	17
635	def		18
636	def		19
637	dbit_20		20
638	def		21
639	def		22
640	def		23
641	def		24
642	def		25
643	def		26
644	def		27
645	def		28
646	def		29
647	def		30
648	def		31
649END(fault_vector_20)
650
651#ifndef CONFIG_64BIT
652
653	.align 2048
654
655ENTRY(fault_vector_11)
656	/* First vector is invalid (0) */
657	.ascii	"cows can fly"
658	.byte 0
659	.align 32
660
661	hpmc		 1
662	def		 2
663	def		 3
664	extint		 4
665	def		 5
666	itlb_11		 6
667	def		 7
668	def		 8
669	def              9
670	def		10
671	def		11
672	def		12
673	def		13
674	def		14
675	dtlb_11		15
676	naitlb_11	16
677	nadtlb_11	17
678	def		18
679	def		19
680	dbit_11		20
681	def		21
682	def		22
683	def		23
684	def		24
685	def		25
686	def		26
687	def		27
688	def		28
689	def		29
690	def		30
691	def		31
692END(fault_vector_11)
693
694#endif
695
696	.import		handle_interruption,code
697	.import		do_cpu_irq_mask,code
698
699	/*
700	 * r26 = function to be called
701	 * r25 = argument to pass in
702	 * r24 = flags for do_fork()
703	 *
704	 * Kernel threads don't ever return, so they don't need
705	 * a true register context. We just save away the arguments
706	 * for copy_thread/ret_ to properly set up the child.
707	 */
708
709#define CLONE_VM 0x100	/* Must agree with <linux/sched.h> */
710#define CLONE_UNTRACED 0x00800000
711
712	.import do_fork
713ENTRY(__kernel_thread)
714	STREG	%r2, -RP_OFFSET(%r30)
715
716	copy	%r30, %r1
717	ldo	PT_SZ_ALGN(%r30),%r30
718#ifdef CONFIG_64BIT
719	/* Yo, function pointers in wide mode are little structs... -PB */
720	ldd	24(%r26), %r2
721	STREG	%r2, PT_GR27(%r1)	/* Store childs %dp */
722	ldd	16(%r26), %r26
723
724	STREG	%r22, PT_GR22(%r1)	/* save r22 (arg5) */
725	copy	%r0, %r22		/* user_tid */
726#endif
727	STREG	%r26, PT_GR26(%r1)  /* Store function & argument for child */
728	STREG	%r25, PT_GR25(%r1)
729	ldil	L%CLONE_UNTRACED, %r26
730	ldo	CLONE_VM(%r26), %r26   /* Force CLONE_VM since only init_mm */
731	or	%r26, %r24, %r26      /* will have kernel mappings.	 */
732	ldi	1, %r25			/* stack_start, signals kernel thread */
733	stw	%r0, -52(%r30)	     	/* user_tid */
734#ifdef CONFIG_64BIT
735	ldo	-16(%r30),%r29		/* Reference param save area */
736#endif
737	BL	do_fork, %r2
738	copy	%r1, %r24		/* pt_regs */
739
740	/* Parent Returns here */
741
742	LDREG	-PT_SZ_ALGN-RP_OFFSET(%r30), %r2
743	ldo	-PT_SZ_ALGN(%r30), %r30
744	bv	%r0(%r2)
745	nop
746ENDPROC(__kernel_thread)
747
748	/*
749	 * Child Returns here
750	 *
751	 * copy_thread moved args from temp save area set up above
752	 * into task save area.
753	 */
754
755ENTRY(ret_from_kernel_thread)
756
757	/* Call schedule_tail first though */
758	BL	schedule_tail, %r2
759	nop
760
761	LDREG	TI_TASK-THREAD_SZ_ALGN(%r30), %r1
762	LDREG	TASK_PT_GR25(%r1), %r26
763#ifdef CONFIG_64BIT
764	LDREG	TASK_PT_GR27(%r1), %r27
765	LDREG	TASK_PT_GR22(%r1), %r22
766#endif
767	LDREG	TASK_PT_GR26(%r1), %r1
768	ble	0(%sr7, %r1)
769	copy	%r31, %r2
770
771#ifdef CONFIG_64BIT
772	ldo	-16(%r30),%r29		/* Reference param save area */
773	loadgp				/* Thread could have been in a module */
774#endif
775#ifndef CONFIG_64BIT
776	b	sys_exit
777#else
778	load32	sys_exit, %r1
779	bv	%r0(%r1)
780#endif
781	ldi	0, %r26
782ENDPROC(ret_from_kernel_thread)
783
784	.import	sys_execve, code
785ENTRY(__execve)
786	copy	%r2, %r15
787	copy	%r30, %r16
788	ldo	PT_SZ_ALGN(%r30), %r30
789	STREG	%r26, PT_GR26(%r16)
790	STREG	%r25, PT_GR25(%r16)
791	STREG	%r24, PT_GR24(%r16)
792#ifdef CONFIG_64BIT
793	ldo	-16(%r30),%r29		/* Reference param save area */
794#endif
795	BL	sys_execve, %r2
796	copy	%r16, %r26
797
798	cmpib,=,n 0,%r28,intr_return    /* forward */
799
800	/* yes, this will trap and die. */
801	copy	%r15, %r2
802	copy	%r16, %r30
803	bv	%r0(%r2)
804	nop
805ENDPROC(__execve)
806
807
808	/*
809	 * struct task_struct *_switch_to(struct task_struct *prev,
810	 *	struct task_struct *next)
811	 *
812	 * switch kernel stacks and return prev */
813ENTRY(_switch_to)
814	STREG	 %r2, -RP_OFFSET(%r30)
815
816	callee_save_float
817	callee_save
818
819	load32	_switch_to_ret, %r2
820
821	STREG	%r2, TASK_PT_KPC(%r26)
822	LDREG	TASK_PT_KPC(%r25), %r2
823
824	STREG	%r30, TASK_PT_KSP(%r26)
825	LDREG	TASK_PT_KSP(%r25), %r30
826	LDREG	TASK_THREAD_INFO(%r25), %r25
827	bv	%r0(%r2)
828	mtctl   %r25,%cr30
829
830_switch_to_ret:
831	mtctl	%r0, %cr0		/* Needed for single stepping */
832	callee_rest
833	callee_rest_float
834
835	LDREG	-RP_OFFSET(%r30), %r2
836	bv	%r0(%r2)
837	copy	%r26, %r28
838ENDPROC(_switch_to)
839
840	/*
841	 * Common rfi return path for interruptions, kernel execve, and
842	 * sys_rt_sigreturn (sometimes).  The sys_rt_sigreturn syscall will
843	 * return via this path if the signal was received when the process
844	 * was running; if the process was blocked on a syscall then the
845	 * normal syscall_exit path is used.  All syscalls for traced
846	 * proceses exit via intr_restore.
847	 *
848	 * XXX If any syscalls that change a processes space id ever exit
849	 * this way, then we will need to copy %sr3 in to PT_SR[3..7], and
850	 * adjust IASQ[0..1].
851	 *
852	 */
853
854	.align	PAGE_SIZE
855
856ENTRY(syscall_exit_rfi)
857	mfctl   %cr30,%r16
858	LDREG	TI_TASK(%r16), %r16	/* thread_info -> task_struct */
859	ldo	TASK_REGS(%r16),%r16
860	/* Force iaoq to userspace, as the user has had access to our current
861	 * context via sigcontext. Also Filter the PSW for the same reason.
862	 */
863	LDREG	PT_IAOQ0(%r16),%r19
864	depi	3,31,2,%r19
865	STREG	%r19,PT_IAOQ0(%r16)
866	LDREG	PT_IAOQ1(%r16),%r19
867	depi	3,31,2,%r19
868	STREG	%r19,PT_IAOQ1(%r16)
869	LDREG   PT_PSW(%r16),%r19
870	load32	USER_PSW_MASK,%r1
871#ifdef CONFIG_64BIT
872	load32	USER_PSW_HI_MASK,%r20
873	depd    %r20,31,32,%r1
874#endif
875	and     %r19,%r1,%r19 /* Mask out bits that user shouldn't play with */
876	load32	USER_PSW,%r1
877	or      %r19,%r1,%r19 /* Make sure default USER_PSW bits are set */
878	STREG   %r19,PT_PSW(%r16)
879
880	/*
881	 * If we aren't being traced, we never saved space registers
882	 * (we don't store them in the sigcontext), so set them
883	 * to "proper" values now (otherwise we'll wind up restoring
884	 * whatever was last stored in the task structure, which might
885	 * be inconsistent if an interrupt occurred while on the gateway
886	 * page). Note that we may be "trashing" values the user put in
887	 * them, but we don't support the user changing them.
888	 */
889
890	STREG   %r0,PT_SR2(%r16)
891	mfsp    %sr3,%r19
892	STREG   %r19,PT_SR0(%r16)
893	STREG   %r19,PT_SR1(%r16)
894	STREG   %r19,PT_SR3(%r16)
895	STREG   %r19,PT_SR4(%r16)
896	STREG   %r19,PT_SR5(%r16)
897	STREG   %r19,PT_SR6(%r16)
898	STREG   %r19,PT_SR7(%r16)
899
900intr_return:
901	/* NOTE: Need to enable interrupts incase we schedule. */
902	ssm     PSW_SM_I, %r0
903
904intr_check_resched:
905
906	/* check for reschedule */
907	mfctl   %cr30,%r1
908	LDREG   TI_FLAGS(%r1),%r19	/* sched.h: TIF_NEED_RESCHED */
909	bb,<,n	%r19,31-TIF_NEED_RESCHED,intr_do_resched /* forward */
910
911	.import do_notify_resume,code
912intr_check_sig:
913	/* As above */
914	mfctl   %cr30,%r1
915	LDREG	TI_FLAGS(%r1),%r19
916	ldi	(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK|_TIF_NOTIFY_RESUME), %r20
917	and,COND(<>)	%r19, %r20, %r0
918	b,n	intr_restore	/* skip past if we've nothing to do */
919
920	/* This check is critical to having LWS
921	 * working. The IASQ is zero on the gateway
922	 * page and we cannot deliver any signals until
923	 * we get off the gateway page.
924	 *
925	 * Only do signals if we are returning to user space
926	 */
927	LDREG	PT_IASQ0(%r16), %r20
928	cmpib,COND(=),n 0,%r20,intr_restore /* backward */
929	LDREG	PT_IASQ1(%r16), %r20
930	cmpib,COND(=),n 0,%r20,intr_restore /* backward */
931
932	copy	%r0, %r25			/* long in_syscall = 0 */
933#ifdef CONFIG_64BIT
934	ldo	-16(%r30),%r29			/* Reference param save area */
935#endif
936
937	BL	do_notify_resume,%r2
938	copy	%r16, %r26			/* struct pt_regs *regs */
939
940	b,n	intr_check_sig
941
942intr_restore:
943	copy            %r16,%r29
944	ldo             PT_FR31(%r29),%r1
945	rest_fp         %r1
946	rest_general    %r29
947
948	/* inverse of virt_map */
949	pcxt_ssm_bug
950	rsm             PSW_SM_QUIET,%r0	/* prepare for rfi */
951	tophys_r1       %r29
952
953	/* Restore space id's and special cr's from PT_REGS
954	 * structure pointed to by r29
955	 */
956	rest_specials	%r29
957
958	/* IMPORTANT: rest_stack restores r29 last (we are using it)!
959	 * It also restores r1 and r30.
960	 */
961	rest_stack
962
963	rfi
964	nop
965
966#ifndef CONFIG_PREEMPT
967# define intr_do_preempt	intr_restore
968#endif /* !CONFIG_PREEMPT */
969
970	.import schedule,code
971intr_do_resched:
972	/* Only call schedule on return to userspace. If we're returning
973	 * to kernel space, we may schedule if CONFIG_PREEMPT, otherwise
974	 * we jump back to intr_restore.
975	 */
976	LDREG	PT_IASQ0(%r16), %r20
977	cmpib,COND(=)	0, %r20, intr_do_preempt
978	nop
979	LDREG	PT_IASQ1(%r16), %r20
980	cmpib,COND(=)	0, %r20, intr_do_preempt
981	nop
982
983#ifdef CONFIG_64BIT
984	ldo	-16(%r30),%r29		/* Reference param save area */
985#endif
986
987	ldil	L%intr_check_sig, %r2
988#ifndef CONFIG_64BIT
989	b	schedule
990#else
991	load32	schedule, %r20
992	bv	%r0(%r20)
993#endif
994	ldo	R%intr_check_sig(%r2), %r2
995
996	/* preempt the current task on returning to kernel
997	 * mode from an interrupt, iff need_resched is set,
998	 * and preempt_count is 0. otherwise, we continue on
999	 * our merry way back to the current running task.
1000	 */
1001#ifdef CONFIG_PREEMPT
1002	.import preempt_schedule_irq,code
1003intr_do_preempt:
1004	rsm	PSW_SM_I, %r0		/* disable interrupts */
1005
1006	/* current_thread_info()->preempt_count */
1007	mfctl	%cr30, %r1
1008	LDREG	TI_PRE_COUNT(%r1), %r19
1009	cmpib,COND(<>)	0, %r19, intr_restore	/* if preempt_count > 0 */
1010	nop				/* prev insn branched backwards */
1011
1012	/* check if we interrupted a critical path */
1013	LDREG	PT_PSW(%r16), %r20
1014	bb,<,n	%r20, 31 - PSW_SM_I, intr_restore
1015	nop
1016
1017	BL	preempt_schedule_irq, %r2
1018	nop
1019
1020	b,n	intr_restore		/* ssm PSW_SM_I done by intr_restore */
1021#endif /* CONFIG_PREEMPT */
1022
1023	/*
1024	 * External interrupts.
1025	 */
1026
1027intr_extint:
1028	cmpib,COND(=),n 0,%r16,1f
1029
1030	get_stack_use_cr30
1031	b,n 2f
1032
10331:
1034	get_stack_use_r30
10352:
1036	save_specials	%r29
1037	virt_map
1038	save_general	%r29
1039
1040	ldo	PT_FR0(%r29), %r24
1041	save_fp	%r24
1042
1043	loadgp
1044
1045	copy	%r29, %r26	/* arg0 is pt_regs */
1046	copy	%r29, %r16	/* save pt_regs */
1047
1048	ldil	L%intr_return, %r2
1049
1050#ifdef CONFIG_64BIT
1051	ldo	-16(%r30),%r29	/* Reference param save area */
1052#endif
1053
1054	b	do_cpu_irq_mask
1055	ldo	R%intr_return(%r2), %r2	/* return to intr_return, not here */
1056ENDPROC(syscall_exit_rfi)
1057
1058
1059	/* Generic interruptions (illegal insn, unaligned, page fault, etc) */
1060
1061ENTRY(intr_save)		/* for os_hpmc */
1062	mfsp    %sr7,%r16
1063	cmpib,COND(=),n 0,%r16,1f
1064	get_stack_use_cr30
1065	b	2f
1066	copy    %r8,%r26
1067
10681:
1069	get_stack_use_r30
1070	copy    %r8,%r26
1071
10722:
1073	save_specials	%r29
1074
1075	/* If this trap is a itlb miss, skip saving/adjusting isr/ior */
1076
1077	/*
1078	 * FIXME: 1) Use a #define for the hardwired "6" below (and in
1079	 *           traps.c.
1080	 *        2) Once we start executing code above 4 Gb, we need
1081	 *           to adjust iasq/iaoq here in the same way we
1082	 *           adjust isr/ior below.
1083	 */
1084
1085	cmpib,COND(=),n        6,%r26,skip_save_ior
1086
1087
1088	mfctl           %cr20, %r16 /* isr */
1089	nop		/* serialize mfctl on PA 2.0 to avoid 4 cycle penalty */
1090	mfctl           %cr21, %r17 /* ior */
1091
1092
1093#ifdef CONFIG_64BIT
1094	/*
1095	 * If the interrupted code was running with W bit off (32 bit),
1096	 * clear the b bits (bits 0 & 1) in the ior.
1097	 * save_specials left ipsw value in r8 for us to test.
1098	 */
1099	extrd,u,*<>     %r8,PSW_W_BIT,1,%r0
1100	depdi           0,1,2,%r17
1101
1102	/*
1103	 * FIXME: This code has hardwired assumptions about the split
1104	 *        between space bits and offset bits. This will change
1105	 *        when we allow alternate page sizes.
1106	 */
1107
1108	/* adjust isr/ior. */
1109	extrd,u         %r16,63,SPACEID_SHIFT,%r1	/* get high bits from isr for ior */
1110	depd            %r1,31,SPACEID_SHIFT,%r17	/* deposit them into ior */
1111	depdi           0,63,SPACEID_SHIFT,%r16		/* clear them from isr */
1112#endif
1113	STREG           %r16, PT_ISR(%r29)
1114	STREG           %r17, PT_IOR(%r29)
1115
1116
1117skip_save_ior:
1118	virt_map
1119	save_general	%r29
1120
1121	ldo		PT_FR0(%r29), %r25
1122	save_fp		%r25
1123
1124	loadgp
1125
1126	copy		%r29, %r25	/* arg1 is pt_regs */
1127#ifdef CONFIG_64BIT
1128	ldo		-16(%r30),%r29	/* Reference param save area */
1129#endif
1130
1131	ldil		L%intr_check_sig, %r2
1132	copy		%r25, %r16	/* save pt_regs */
1133
1134	b		handle_interruption
1135	ldo		R%intr_check_sig(%r2), %r2
1136ENDPROC(intr_save)
1137
1138
1139	/*
1140	 * Note for all tlb miss handlers:
1141	 *
1142	 * cr24 contains a pointer to the kernel address space
1143	 * page directory.
1144	 *
1145	 * cr25 contains a pointer to the current user address
1146	 * space page directory.
1147	 *
1148	 * sr3 will contain the space id of the user address space
1149	 * of the current running thread while that thread is
1150	 * running in the kernel.
1151	 */
1152
1153	/*
1154	 * register number allocations.  Note that these are all
1155	 * in the shadowed registers
1156	 */
1157
1158	t0 = r1		/* temporary register 0 */
1159	va = r8		/* virtual address for which the trap occurred */
1160	t1 = r9		/* temporary register 1 */
1161	pte  = r16	/* pte/phys page # */
1162	prot = r17	/* prot bits */
1163	spc  = r24	/* space for which the trap occurred */
1164	ptp = r25	/* page directory/page table pointer */
1165
1166#ifdef CONFIG_64BIT
1167
1168dtlb_miss_20w:
1169	space_adjust	spc,va,t0
1170	get_pgd		spc,ptp
1171	space_check	spc,t0,dtlb_fault
1172
1173	L3_ptep		ptp,pte,t0,va,dtlb_check_alias_20w
1174
1175	update_ptep	ptp,pte,t0,t1
1176
1177	make_insert_tlb	spc,pte,prot
1178
1179	idtlbt          pte,prot
1180
1181	rfir
1182	nop
1183
1184dtlb_check_alias_20w:
1185	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault
1186
1187	idtlbt          pte,prot
1188
1189	rfir
1190	nop
1191
1192nadtlb_miss_20w:
1193	space_adjust	spc,va,t0
1194	get_pgd		spc,ptp
1195	space_check	spc,t0,nadtlb_fault
1196
1197	L3_ptep		ptp,pte,t0,va,nadtlb_check_alias_20w
1198
1199	update_ptep	ptp,pte,t0,t1
1200
1201	make_insert_tlb	spc,pte,prot
1202
1203	idtlbt          pte,prot
1204
1205	rfir
1206	nop
1207
1208nadtlb_check_alias_20w:
1209	do_alias	spc,t0,t1,va,pte,prot,nadtlb_emulate
1210
1211	idtlbt          pte,prot
1212
1213	rfir
1214	nop
1215
1216#else
1217
1218dtlb_miss_11:
1219	get_pgd		spc,ptp
1220
1221	space_check	spc,t0,dtlb_fault
1222
1223	L2_ptep		ptp,pte,t0,va,dtlb_check_alias_11
1224
1225	update_ptep	ptp,pte,t0,t1
1226
1227	make_insert_tlb_11	spc,pte,prot
1228
1229	mfsp		%sr1,t0  /* Save sr1 so we can use it in tlb inserts */
1230	mtsp		spc,%sr1
1231
1232	idtlba		pte,(%sr1,va)
1233	idtlbp		prot,(%sr1,va)
1234
1235	mtsp		t0, %sr1	/* Restore sr1 */
1236
1237	rfir
1238	nop
1239
1240dtlb_check_alias_11:
1241	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault
1242
1243	idtlba          pte,(va)
1244	idtlbp          prot,(va)
1245
1246	rfir
1247	nop
1248
1249nadtlb_miss_11:
1250	get_pgd		spc,ptp
1251
1252	space_check	spc,t0,nadtlb_fault
1253
1254	L2_ptep		ptp,pte,t0,va,nadtlb_check_alias_11
1255
1256	update_ptep	ptp,pte,t0,t1
1257
1258	make_insert_tlb_11	spc,pte,prot
1259
1260
1261	mfsp		%sr1,t0  /* Save sr1 so we can use it in tlb inserts */
1262	mtsp		spc,%sr1
1263
1264	idtlba		pte,(%sr1,va)
1265	idtlbp		prot,(%sr1,va)
1266
1267	mtsp		t0, %sr1	/* Restore sr1 */
1268
1269	rfir
1270	nop
1271
1272nadtlb_check_alias_11:
1273	do_alias	spc,t0,t1,va,pte,prot,nadtlb_emulate
1274
1275	idtlba          pte,(va)
1276	idtlbp          prot,(va)
1277
1278	rfir
1279	nop
1280
1281dtlb_miss_20:
1282	space_adjust	spc,va,t0
1283	get_pgd		spc,ptp
1284	space_check	spc,t0,dtlb_fault
1285
1286	L2_ptep		ptp,pte,t0,va,dtlb_check_alias_20
1287
1288	update_ptep	ptp,pte,t0,t1
1289
1290	make_insert_tlb	spc,pte,prot
1291
1292	f_extend	pte,t0
1293
1294	idtlbt          pte,prot
1295
1296	rfir
1297	nop
1298
1299dtlb_check_alias_20:
1300	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault
1301
1302	idtlbt          pte,prot
1303
1304	rfir
1305	nop
1306
1307nadtlb_miss_20:
1308	get_pgd		spc,ptp
1309
1310	space_check	spc,t0,nadtlb_fault
1311
1312	L2_ptep		ptp,pte,t0,va,nadtlb_check_alias_20
1313
1314	update_ptep	ptp,pte,t0,t1
1315
1316	make_insert_tlb	spc,pte,prot
1317
1318	f_extend	pte,t0
1319
1320        idtlbt          pte,prot
1321
1322	rfir
1323	nop
1324
1325nadtlb_check_alias_20:
1326	do_alias	spc,t0,t1,va,pte,prot,nadtlb_emulate
1327
1328	idtlbt          pte,prot
1329
1330	rfir
1331	nop
1332
1333#endif
1334
1335nadtlb_emulate:
1336
1337	/*
1338	 * Non access misses can be caused by fdc,fic,pdc,lpa,probe and
1339	 * probei instructions. We don't want to fault for these
1340	 * instructions (not only does it not make sense, it can cause
1341	 * deadlocks, since some flushes are done with the mmap
1342	 * semaphore held). If the translation doesn't exist, we can't
1343	 * insert a translation, so have to emulate the side effects
1344	 * of the instruction. Since we don't insert a translation
1345	 * we can get a lot of faults during a flush loop, so it makes
1346	 * sense to try to do it here with minimum overhead. We only
1347	 * emulate fdc,fic,pdc,probew,prober instructions whose base
1348	 * and index registers are not shadowed. We defer everything
1349	 * else to the "slow" path.
1350	 */
1351
1352	mfctl           %cr19,%r9 /* Get iir */
1353
1354	/* PA 2.0 Arch Ref. Book pg 382 has a good description of the insn bits.
1355	   Checks for fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw */
1356
1357	/* Checks for fdc,fdce,pdc,"fic,4f" only */
1358	ldi             0x280,%r16
1359	and             %r9,%r16,%r17
1360	cmpb,<>,n       %r16,%r17,nadtlb_probe_check
1361	bb,>=,n         %r9,26,nadtlb_nullify  /* m bit not set, just nullify */
1362	BL		get_register,%r25
1363	extrw,u         %r9,15,5,%r8           /* Get index register # */
1364	cmpib,COND(=),n        -1,%r1,nadtlb_fault    /* have to use slow path */
1365	copy            %r1,%r24
1366	BL		get_register,%r25
1367	extrw,u         %r9,10,5,%r8           /* Get base register # */
1368	cmpib,COND(=),n        -1,%r1,nadtlb_fault    /* have to use slow path */
1369	BL		set_register,%r25
1370	add,l           %r1,%r24,%r1           /* doesn't affect c/b bits */
1371
1372nadtlb_nullify:
1373	mfctl           %ipsw,%r8
1374	ldil            L%PSW_N,%r9
1375	or              %r8,%r9,%r8            /* Set PSW_N */
1376	mtctl           %r8,%ipsw
1377
1378	rfir
1379	nop
1380
1381	/*
1382		When there is no translation for the probe address then we
1383		must nullify the insn and return zero in the target regsiter.
1384		This will indicate to the calling code that it does not have
1385		write/read privileges to this address.
1386
1387		This should technically work for prober and probew in PA 1.1,
1388		and also probe,r and probe,w in PA 2.0
1389
1390		WARNING: USE ONLY NON-SHADOW REGISTERS WITH PROBE INSN!
1391		THE SLOW-PATH EMULATION HAS NOT BEEN WRITTEN YET.
1392
1393	*/
1394nadtlb_probe_check:
1395	ldi             0x80,%r16
1396	and             %r9,%r16,%r17
1397	cmpb,<>,n       %r16,%r17,nadtlb_fault /* Must be probe,[rw]*/
1398	BL              get_register,%r25      /* Find the target register */
1399	extrw,u         %r9,31,5,%r8           /* Get target register */
1400	cmpib,COND(=),n        -1,%r1,nadtlb_fault    /* have to use slow path */
1401	BL		set_register,%r25
1402	copy            %r0,%r1                /* Write zero to target register */
1403	b nadtlb_nullify                       /* Nullify return insn */
1404	nop
1405
1406
1407#ifdef CONFIG_64BIT
1408itlb_miss_20w:
1409
1410	/*
1411	 * I miss is a little different, since we allow users to fault
1412	 * on the gateway page which is in the kernel address space.
1413	 */
1414
1415	space_adjust	spc,va,t0
1416	get_pgd		spc,ptp
1417	space_check	spc,t0,itlb_fault
1418
1419	L3_ptep		ptp,pte,t0,va,itlb_fault
1420
1421	update_ptep	ptp,pte,t0,t1
1422
1423	make_insert_tlb	spc,pte,prot
1424
1425	iitlbt          pte,prot
1426
1427	rfir
1428	nop
1429
1430naitlb_miss_20w:
1431
1432	/*
1433	 * I miss is a little different, since we allow users to fault
1434	 * on the gateway page which is in the kernel address space.
1435	 */
1436
1437	space_adjust	spc,va,t0
1438	get_pgd		spc,ptp
1439	space_check	spc,t0,naitlb_fault
1440
1441	L3_ptep		ptp,pte,t0,va,naitlb_check_alias_20w
1442
1443	update_ptep	ptp,pte,t0,t1
1444
1445	make_insert_tlb	spc,pte,prot
1446
1447	iitlbt          pte,prot
1448
1449	rfir
1450	nop
1451
1452naitlb_check_alias_20w:
1453	do_alias	spc,t0,t1,va,pte,prot,naitlb_fault
1454
1455	iitlbt		pte,prot
1456
1457	rfir
1458	nop
1459
1460#else
1461
1462itlb_miss_11:
1463	get_pgd		spc,ptp
1464
1465	space_check	spc,t0,itlb_fault
1466
1467	L2_ptep		ptp,pte,t0,va,itlb_fault
1468
1469	update_ptep	ptp,pte,t0,t1
1470
1471	make_insert_tlb_11	spc,pte,prot
1472
1473	mfsp		%sr1,t0  /* Save sr1 so we can use it in tlb inserts */
1474	mtsp		spc,%sr1
1475
1476	iitlba		pte,(%sr1,va)
1477	iitlbp		prot,(%sr1,va)
1478
1479	mtsp		t0, %sr1	/* Restore sr1 */
1480
1481	rfir
1482	nop
1483
1484naitlb_miss_11:
1485	get_pgd		spc,ptp
1486
1487	space_check	spc,t0,naitlb_fault
1488
1489	L2_ptep		ptp,pte,t0,va,naitlb_check_alias_11
1490
1491	update_ptep	ptp,pte,t0,t1
1492
1493	make_insert_tlb_11	spc,pte,prot
1494
1495	mfsp		%sr1,t0  /* Save sr1 so we can use it in tlb inserts */
1496	mtsp		spc,%sr1
1497
1498	iitlba		pte,(%sr1,va)
1499	iitlbp		prot,(%sr1,va)
1500
1501	mtsp		t0, %sr1	/* Restore sr1 */
1502
1503	rfir
1504	nop
1505
1506naitlb_check_alias_11:
1507	do_alias	spc,t0,t1,va,pte,prot,itlb_fault
1508
1509	iitlba          pte,(%sr0, va)
1510	iitlbp          prot,(%sr0, va)
1511
1512	rfir
1513	nop
1514
1515
1516itlb_miss_20:
1517	get_pgd		spc,ptp
1518
1519	space_check	spc,t0,itlb_fault
1520
1521	L2_ptep		ptp,pte,t0,va,itlb_fault
1522
1523	update_ptep	ptp,pte,t0,t1
1524
1525	make_insert_tlb	spc,pte,prot
1526
1527	f_extend	pte,t0
1528
1529	iitlbt          pte,prot
1530
1531	rfir
1532	nop
1533
1534naitlb_miss_20:
1535	get_pgd		spc,ptp
1536
1537	space_check	spc,t0,naitlb_fault
1538
1539	L2_ptep		ptp,pte,t0,va,naitlb_check_alias_20
1540
1541	update_ptep	ptp,pte,t0,t1
1542
1543	make_insert_tlb	spc,pte,prot
1544
1545	f_extend	pte,t0
1546
1547	iitlbt          pte,prot
1548
1549	rfir
1550	nop
1551
1552naitlb_check_alias_20:
1553	do_alias	spc,t0,t1,va,pte,prot,naitlb_fault
1554
1555	iitlbt          pte,prot
1556
1557	rfir
1558	nop
1559
1560#endif
1561
1562#ifdef CONFIG_64BIT
1563
1564dbit_trap_20w:
1565	space_adjust	spc,va,t0
1566	get_pgd		spc,ptp
1567	space_check	spc,t0,dbit_fault
1568
1569	L3_ptep		ptp,pte,t0,va,dbit_fault
1570
1571#ifdef CONFIG_SMP
1572	cmpib,COND(=),n        0,spc,dbit_nolock_20w
1573	load32		PA(pa_dbit_lock),t0
1574
1575dbit_spin_20w:
1576	LDCW		0(t0),t1
1577	cmpib,COND(=)         0,t1,dbit_spin_20w
1578	nop
1579
1580dbit_nolock_20w:
1581#endif
1582	update_dirty	ptp,pte,t1
1583
1584	make_insert_tlb	spc,pte,prot
1585
1586	idtlbt          pte,prot
1587#ifdef CONFIG_SMP
1588	cmpib,COND(=),n        0,spc,dbit_nounlock_20w
1589	ldi             1,t1
1590	stw             t1,0(t0)
1591
1592dbit_nounlock_20w:
1593#endif
1594
1595	rfir
1596	nop
1597#else
1598
1599dbit_trap_11:
1600
1601	get_pgd		spc,ptp
1602
1603	space_check	spc,t0,dbit_fault
1604
1605	L2_ptep		ptp,pte,t0,va,dbit_fault
1606
1607#ifdef CONFIG_SMP
1608	cmpib,COND(=),n        0,spc,dbit_nolock_11
1609	load32		PA(pa_dbit_lock),t0
1610
1611dbit_spin_11:
1612	LDCW		0(t0),t1
1613	cmpib,=         0,t1,dbit_spin_11
1614	nop
1615
1616dbit_nolock_11:
1617#endif
1618	update_dirty	ptp,pte,t1
1619
1620	make_insert_tlb_11	spc,pte,prot
1621
1622	mfsp            %sr1,t1  /* Save sr1 so we can use it in tlb inserts */
1623	mtsp		spc,%sr1
1624
1625	idtlba		pte,(%sr1,va)
1626	idtlbp		prot,(%sr1,va)
1627
1628	mtsp            t1, %sr1     /* Restore sr1 */
1629#ifdef CONFIG_SMP
1630	cmpib,COND(=),n        0,spc,dbit_nounlock_11
1631	ldi             1,t1
1632	stw             t1,0(t0)
1633
1634dbit_nounlock_11:
1635#endif
1636
1637	rfir
1638	nop
1639
1640dbit_trap_20:
1641	get_pgd		spc,ptp
1642
1643	space_check	spc,t0,dbit_fault
1644
1645	L2_ptep		ptp,pte,t0,va,dbit_fault
1646
1647#ifdef CONFIG_SMP
1648	cmpib,COND(=),n        0,spc,dbit_nolock_20
1649	load32		PA(pa_dbit_lock),t0
1650
1651dbit_spin_20:
1652	LDCW		0(t0),t1
1653	cmpib,=         0,t1,dbit_spin_20
1654	nop
1655
1656dbit_nolock_20:
1657#endif
1658	update_dirty	ptp,pte,t1
1659
1660	make_insert_tlb	spc,pte,prot
1661
1662	f_extend	pte,t1
1663
1664        idtlbt          pte,prot
1665
1666#ifdef CONFIG_SMP
1667	cmpib,COND(=),n        0,spc,dbit_nounlock_20
1668	ldi             1,t1
1669	stw             t1,0(t0)
1670
1671dbit_nounlock_20:
1672#endif
1673
1674	rfir
1675	nop
1676#endif
1677
1678	.import handle_interruption,code
1679
1680kernel_bad_space:
1681	b               intr_save
1682	ldi             31,%r8  /* Use an unused code */
1683
1684dbit_fault:
1685	b               intr_save
1686	ldi             20,%r8
1687
1688itlb_fault:
1689	b               intr_save
1690	ldi             6,%r8
1691
1692nadtlb_fault:
1693	b               intr_save
1694	ldi             17,%r8
1695
1696naitlb_fault:
1697	b               intr_save
1698	ldi             16,%r8
1699
1700dtlb_fault:
1701	b               intr_save
1702	ldi             15,%r8
1703
1704	/* Register saving semantics for system calls:
1705
1706	   %r1		   clobbered by system call macro in userspace
1707	   %r2		   saved in PT_REGS by gateway page
1708	   %r3  - %r18	   preserved by C code (saved by signal code)
1709	   %r19 - %r20	   saved in PT_REGS by gateway page
1710	   %r21 - %r22	   non-standard syscall args
1711			   stored in kernel stack by gateway page
1712	   %r23 - %r26	   arg3-arg0, saved in PT_REGS by gateway page
1713	   %r27 - %r30	   saved in PT_REGS by gateway page
1714	   %r31		   syscall return pointer
1715	 */
1716
1717	/* Floating point registers (FIXME: what do we do with these?)
1718
1719	   %fr0  - %fr3	   status/exception, not preserved
1720	   %fr4  - %fr7	   arguments
1721	   %fr8	 - %fr11   not preserved by C code
1722	   %fr12 - %fr21   preserved by C code
1723	   %fr22 - %fr31   not preserved by C code
1724	 */
1725
1726	.macro	reg_save regs
1727	STREG	%r3, PT_GR3(\regs)
1728	STREG	%r4, PT_GR4(\regs)
1729	STREG	%r5, PT_GR5(\regs)
1730	STREG	%r6, PT_GR6(\regs)
1731	STREG	%r7, PT_GR7(\regs)
1732	STREG	%r8, PT_GR8(\regs)
1733	STREG	%r9, PT_GR9(\regs)
1734	STREG   %r10,PT_GR10(\regs)
1735	STREG   %r11,PT_GR11(\regs)
1736	STREG   %r12,PT_GR12(\regs)
1737	STREG   %r13,PT_GR13(\regs)
1738	STREG   %r14,PT_GR14(\regs)
1739	STREG   %r15,PT_GR15(\regs)
1740	STREG   %r16,PT_GR16(\regs)
1741	STREG   %r17,PT_GR17(\regs)
1742	STREG   %r18,PT_GR18(\regs)
1743	.endm
1744
1745	.macro	reg_restore regs
1746	LDREG	PT_GR3(\regs), %r3
1747	LDREG	PT_GR4(\regs), %r4
1748	LDREG	PT_GR5(\regs), %r5
1749	LDREG	PT_GR6(\regs), %r6
1750	LDREG	PT_GR7(\regs), %r7
1751	LDREG	PT_GR8(\regs), %r8
1752	LDREG	PT_GR9(\regs), %r9
1753	LDREG   PT_GR10(\regs),%r10
1754	LDREG   PT_GR11(\regs),%r11
1755	LDREG   PT_GR12(\regs),%r12
1756	LDREG   PT_GR13(\regs),%r13
1757	LDREG   PT_GR14(\regs),%r14
1758	LDREG   PT_GR15(\regs),%r15
1759	LDREG   PT_GR16(\regs),%r16
1760	LDREG   PT_GR17(\regs),%r17
1761	LDREG   PT_GR18(\regs),%r18
1762	.endm
1763
1764ENTRY(sys_fork_wrapper)
1765	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
1766	ldo	TASK_REGS(%r1),%r1
1767	reg_save %r1
1768	mfctl	%cr27, %r3
1769	STREG	%r3, PT_CR27(%r1)
1770
1771	STREG	%r2,-RP_OFFSET(%r30)
1772	ldo	FRAME_SIZE(%r30),%r30
1773#ifdef CONFIG_64BIT
1774	ldo	-16(%r30),%r29		/* Reference param save area */
1775#endif
1776
1777	/* These are call-clobbered registers and therefore
1778	   also syscall-clobbered (we hope). */
1779	STREG	%r2,PT_GR19(%r1)	/* save for child */
1780	STREG	%r30,PT_GR21(%r1)
1781
1782	LDREG	PT_GR30(%r1),%r25
1783	copy	%r1,%r24
1784	BL	sys_clone,%r2
1785	ldi	SIGCHLD,%r26
1786
1787	LDREG	-RP_OFFSET-FRAME_SIZE(%r30),%r2
1788wrapper_exit:
1789	ldo	-FRAME_SIZE(%r30),%r30		/* get the stackframe */
1790	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1791	ldo	TASK_REGS(%r1),%r1	 /* get pt regs */
1792
1793	LDREG	PT_CR27(%r1), %r3
1794	mtctl	%r3, %cr27
1795	reg_restore %r1
1796
1797	/* strace expects syscall # to be preserved in r20 */
1798	ldi	__NR_fork,%r20
1799	bv %r0(%r2)
1800	STREG	%r20,PT_GR20(%r1)
1801ENDPROC(sys_fork_wrapper)
1802
1803	/* Set the return value for the child */
1804ENTRY(child_return)
1805	BL	schedule_tail, %r2
1806	nop
1807
1808	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE-FRAME_SIZE(%r30), %r1
1809	LDREG	TASK_PT_GR19(%r1),%r2
1810	b	wrapper_exit
1811	copy	%r0,%r28
1812ENDPROC(child_return)
1813
1814
1815ENTRY(sys_clone_wrapper)
1816	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1817	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
1818	reg_save %r1
1819	mfctl	%cr27, %r3
1820	STREG	%r3, PT_CR27(%r1)
1821
1822	STREG	%r2,-RP_OFFSET(%r30)
1823	ldo	FRAME_SIZE(%r30),%r30
1824#ifdef CONFIG_64BIT
1825	ldo	-16(%r30),%r29		/* Reference param save area */
1826#endif
1827
1828	/* WARNING - Clobbers r19 and r21, userspace must save these! */
1829	STREG	%r2,PT_GR19(%r1)	/* save for child */
1830	STREG	%r30,PT_GR21(%r1)
1831	BL	sys_clone,%r2
1832	copy	%r1,%r24
1833
1834	b	wrapper_exit
1835	LDREG	-RP_OFFSET-FRAME_SIZE(%r30),%r2
1836ENDPROC(sys_clone_wrapper)
1837
1838
1839ENTRY(sys_vfork_wrapper)
1840	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1841	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
1842	reg_save %r1
1843	mfctl	%cr27, %r3
1844	STREG	%r3, PT_CR27(%r1)
1845
1846	STREG	%r2,-RP_OFFSET(%r30)
1847	ldo	FRAME_SIZE(%r30),%r30
1848#ifdef CONFIG_64BIT
1849	ldo	-16(%r30),%r29		/* Reference param save area */
1850#endif
1851
1852	STREG	%r2,PT_GR19(%r1)	/* save for child */
1853	STREG	%r30,PT_GR21(%r1)
1854
1855	BL	sys_vfork,%r2
1856	copy	%r1,%r26
1857
1858	b	wrapper_exit
1859	LDREG	-RP_OFFSET-FRAME_SIZE(%r30),%r2
1860ENDPROC(sys_vfork_wrapper)
1861
1862
1863	.macro  execve_wrapper execve
1864	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1865	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
1866
1867	/*
1868	 * Do we need to save/restore r3-r18 here?
1869	 * I don't think so. why would new thread need old
1870	 * threads registers?
1871	 */
1872
1873	/* %arg0 - %arg3 are already saved for us. */
1874
1875	STREG %r2,-RP_OFFSET(%r30)
1876	ldo FRAME_SIZE(%r30),%r30
1877#ifdef CONFIG_64BIT
1878	ldo	-16(%r30),%r29		/* Reference param save area */
1879#endif
1880	BL \execve,%r2
1881	copy %r1,%arg0
1882
1883	ldo -FRAME_SIZE(%r30),%r30
1884	LDREG -RP_OFFSET(%r30),%r2
1885
1886	/* If exec succeeded we need to load the args */
1887
1888	ldo -1024(%r0),%r1
1889	cmpb,>>= %r28,%r1,error_\execve
1890	copy %r2,%r19
1891
1892error_\execve:
1893	bv %r0(%r19)
1894	nop
1895	.endm
1896
1897	.import sys_execve
1898ENTRY(sys_execve_wrapper)
1899	execve_wrapper sys_execve
1900ENDPROC(sys_execve_wrapper)
1901
1902#ifdef CONFIG_64BIT
1903	.import sys32_execve
1904ENTRY(sys32_execve_wrapper)
1905	execve_wrapper sys32_execve
1906ENDPROC(sys32_execve_wrapper)
1907#endif
1908
1909ENTRY(sys_rt_sigreturn_wrapper)
1910	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r26
1911	ldo	TASK_REGS(%r26),%r26	/* get pt regs */
1912	/* Don't save regs, we are going to restore them from sigcontext. */
1913	STREG	%r2, -RP_OFFSET(%r30)
1914#ifdef CONFIG_64BIT
1915	ldo	FRAME_SIZE(%r30), %r30
1916	BL	sys_rt_sigreturn,%r2
1917	ldo	-16(%r30),%r29		/* Reference param save area */
1918#else
1919	BL	sys_rt_sigreturn,%r2
1920	ldo	FRAME_SIZE(%r30), %r30
1921#endif
1922
1923	ldo	-FRAME_SIZE(%r30), %r30
1924	LDREG	-RP_OFFSET(%r30), %r2
1925
1926	/* FIXME: I think we need to restore a few more things here. */
1927	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1928	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
1929	reg_restore %r1
1930
1931	/* If the signal was received while the process was blocked on a
1932	 * syscall, then r2 will take us to syscall_exit; otherwise r2 will
1933	 * take us to syscall_exit_rfi and on to intr_return.
1934	 */
1935	bv	%r0(%r2)
1936	LDREG	PT_GR28(%r1),%r28  /* reload original r28 for syscall_exit */
1937ENDPROC(sys_rt_sigreturn_wrapper)
1938
1939ENTRY(sys_sigaltstack_wrapper)
1940	/* Get the user stack pointer */
1941	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1942	ldo	TASK_REGS(%r1),%r24	/* get pt regs */
1943	LDREG	TASK_PT_GR30(%r24),%r24
1944	STREG	%r2, -RP_OFFSET(%r30)
1945#ifdef CONFIG_64BIT
1946	ldo	FRAME_SIZE(%r30), %r30
1947	BL	do_sigaltstack,%r2
1948	ldo	-16(%r30),%r29		/* Reference param save area */
1949#else
1950	BL	do_sigaltstack,%r2
1951	ldo	FRAME_SIZE(%r30), %r30
1952#endif
1953
1954	ldo	-FRAME_SIZE(%r30), %r30
1955	LDREG	-RP_OFFSET(%r30), %r2
1956	bv	%r0(%r2)
1957	nop
1958ENDPROC(sys_sigaltstack_wrapper)
1959
1960#ifdef CONFIG_64BIT
1961ENTRY(sys32_sigaltstack_wrapper)
1962	/* Get the user stack pointer */
1963	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r24
1964	LDREG	TASK_PT_GR30(%r24),%r24
1965	STREG	%r2, -RP_OFFSET(%r30)
1966	ldo	FRAME_SIZE(%r30), %r30
1967	BL	do_sigaltstack32,%r2
1968	ldo	-16(%r30),%r29		/* Reference param save area */
1969
1970	ldo	-FRAME_SIZE(%r30), %r30
1971	LDREG	-RP_OFFSET(%r30), %r2
1972	bv	%r0(%r2)
1973	nop
1974ENDPROC(sys32_sigaltstack_wrapper)
1975#endif
1976
1977ENTRY(syscall_exit)
1978	/* NOTE: HP-UX syscalls also come through here
1979	 * after hpux_syscall_exit fixes up return
1980	 * values. */
1981
1982	/* NOTE: Not all syscalls exit this way.  rt_sigreturn will exit
1983	 * via syscall_exit_rfi if the signal was received while the process
1984	 * was running.
1985	 */
1986
1987	/* save return value now */
1988
1989	mfctl     %cr30, %r1
1990	LDREG     TI_TASK(%r1),%r1
1991	STREG     %r28,TASK_PT_GR28(%r1)
1992
1993#ifdef CONFIG_HPUX
1994/* <linux/personality.h> cannot be easily included */
1995#define PER_HPUX 0x10
1996	ldw	TASK_PERSONALITY(%r1),%r19
1997
1998	/* We can't use "CMPIB<> PER_HPUX" since "im5" field is sign extended */
1999	ldo	  -PER_HPUX(%r19), %r19
2000	cmpib,COND(<>),n 0,%r19,1f
2001
2002	/* Save other hpux returns if personality is PER_HPUX */
2003	STREG     %r22,TASK_PT_GR22(%r1)
2004	STREG     %r29,TASK_PT_GR29(%r1)
20051:
2006
2007#endif /* CONFIG_HPUX */
2008
2009	/* Seems to me that dp could be wrong here, if the syscall involved
2010	 * calling a module, and nothing got round to restoring dp on return.
2011	 */
2012	loadgp
2013
2014syscall_check_resched:
2015
2016	/* check for reschedule */
2017
2018	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19	/* long */
2019	bb,<,n	%r19, 31-TIF_NEED_RESCHED, syscall_do_resched /* forward */
2020
2021	.import do_signal,code
2022syscall_check_sig:
2023	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
2024	ldi	(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK), %r26
2025	and,COND(<>)	%r19, %r26, %r0
2026	b,n	syscall_restore	/* skip past if we've nothing to do */
2027
2028syscall_do_signal:
2029	/* Save callee-save registers (for sigcontext).
2030	 * FIXME: After this point the process structure should be
2031	 * consistent with all the relevant state of the process
2032	 * before the syscall.  We need to verify this.
2033	 */
2034	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
2035	ldo	TASK_REGS(%r1), %r26		/* struct pt_regs *regs */
2036	reg_save %r26
2037
2038#ifdef CONFIG_64BIT
2039	ldo	-16(%r30),%r29			/* Reference param save area */
2040#endif
2041
2042	BL	do_notify_resume,%r2
2043	ldi	1, %r25				/* long in_syscall = 1 */
2044
2045	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
2046	ldo	TASK_REGS(%r1), %r20		/* reload pt_regs */
2047	reg_restore %r20
2048
2049	b,n     syscall_check_sig
2050
2051syscall_restore:
2052	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
2053
2054	/* Are we being ptraced? */
2055	ldw	TASK_FLAGS(%r1),%r19
2056	ldi	(_TIF_SINGLESTEP|_TIF_BLOCKSTEP),%r2
2057	and,COND(=)	%r19,%r2,%r0
2058	b,n	syscall_restore_rfi
2059
2060	ldo	TASK_PT_FR31(%r1),%r19		   /* reload fpregs */
2061	rest_fp	%r19
2062
2063	LDREG	TASK_PT_SAR(%r1),%r19		   /* restore SAR */
2064	mtsar	%r19
2065
2066	LDREG	TASK_PT_GR2(%r1),%r2		   /* restore user rp */
2067	LDREG	TASK_PT_GR19(%r1),%r19
2068	LDREG   TASK_PT_GR20(%r1),%r20
2069	LDREG	TASK_PT_GR21(%r1),%r21
2070	LDREG	TASK_PT_GR22(%r1),%r22
2071	LDREG	TASK_PT_GR23(%r1),%r23
2072	LDREG	TASK_PT_GR24(%r1),%r24
2073	LDREG	TASK_PT_GR25(%r1),%r25
2074	LDREG	TASK_PT_GR26(%r1),%r26
2075	LDREG	TASK_PT_GR27(%r1),%r27	   /* restore user dp */
2076	LDREG	TASK_PT_GR28(%r1),%r28	   /* syscall return value */
2077	LDREG	TASK_PT_GR29(%r1),%r29
2078	LDREG	TASK_PT_GR31(%r1),%r31	   /* restore syscall rp */
2079
2080	/* NOTE: We use rsm/ssm pair to make this operation atomic */
2081	LDREG   TASK_PT_GR30(%r1),%r1              /* Get user sp */
2082	rsm     PSW_SM_I, %r0
2083	copy    %r1,%r30                           /* Restore user sp */
2084	mfsp    %sr3,%r1                           /* Get user space id */
2085	mtsp    %r1,%sr7                           /* Restore sr7 */
2086	ssm     PSW_SM_I, %r0
2087
2088	/* Set sr2 to zero for userspace syscalls to work. */
2089	mtsp	%r0,%sr2
2090	mtsp	%r1,%sr4			   /* Restore sr4 */
2091	mtsp	%r1,%sr5			   /* Restore sr5 */
2092	mtsp	%r1,%sr6			   /* Restore sr6 */
2093
2094	depi	3,31,2,%r31			   /* ensure return to user mode. */
2095
2096#ifdef CONFIG_64BIT
2097	/* decide whether to reset the wide mode bit
2098	 *
2099	 * For a syscall, the W bit is stored in the lowest bit
2100	 * of sp.  Extract it and reset W if it is zero */
2101	extrd,u,*<>	%r30,63,1,%r1
2102	rsm	PSW_SM_W, %r0
2103	/* now reset the lowest bit of sp if it was set */
2104	xor	%r30,%r1,%r30
2105#endif
2106	be,n    0(%sr3,%r31)                       /* return to user space */
2107
2108	/* We have to return via an RFI, so that PSW T and R bits can be set
2109	 * appropriately.
2110	 * This sets up pt_regs so we can return via intr_restore, which is not
2111	 * the most efficient way of doing things, but it works.
2112	 */
2113syscall_restore_rfi:
2114	ldo	-1(%r0),%r2			   /* Set recovery cntr to -1 */
2115	mtctl	%r2,%cr0			   /*   for immediate trap */
2116	LDREG	TASK_PT_PSW(%r1),%r2		   /* Get old PSW */
2117	ldi	0x0b,%r20			   /* Create new PSW */
2118	depi	-1,13,1,%r20			   /* C, Q, D, and I bits */
2119
2120	/* The values of SINGLESTEP_BIT and BLOCKSTEP_BIT are
2121	 * set in thread_info.h and converted to PA bitmap
2122	 * numbers in asm-offsets.c */
2123
2124	/* if ((%r19.SINGLESTEP_BIT)) { %r20.27=1} */
2125	extru,=	%r19,TIF_SINGLESTEP_PA_BIT,1,%r0
2126	depi	-1,27,1,%r20			   /* R bit */
2127
2128	/* if ((%r19.BLOCKSTEP_BIT)) { %r20.7=1} */
2129	extru,= %r19,TIF_BLOCKSTEP_PA_BIT,1,%r0
2130	depi	-1,7,1,%r20			   /* T bit */
2131
2132	STREG	%r20,TASK_PT_PSW(%r1)
2133
2134	/* Always store space registers, since sr3 can be changed (e.g. fork) */
2135
2136	mfsp    %sr3,%r25
2137	STREG   %r25,TASK_PT_SR3(%r1)
2138	STREG   %r25,TASK_PT_SR4(%r1)
2139	STREG   %r25,TASK_PT_SR5(%r1)
2140	STREG   %r25,TASK_PT_SR6(%r1)
2141	STREG   %r25,TASK_PT_SR7(%r1)
2142	STREG   %r25,TASK_PT_IASQ0(%r1)
2143	STREG   %r25,TASK_PT_IASQ1(%r1)
2144
2145	/* XXX W bit??? */
2146	/* Now if old D bit is clear, it means we didn't save all registers
2147	 * on syscall entry, so do that now.  This only happens on TRACEME
2148	 * calls, or if someone attached to us while we were on a syscall.
2149	 * We could make this more efficient by not saving r3-r18, but
2150	 * then we wouldn't be able to use the common intr_restore path.
2151	 * It is only for traced processes anyway, so performance is not
2152	 * an issue.
2153	 */
2154	bb,<	%r2,30,pt_regs_ok		   /* Branch if D set */
2155	ldo	TASK_REGS(%r1),%r25
2156	reg_save %r25				   /* Save r3 to r18 */
2157
2158	/* Save the current sr */
2159	mfsp	%sr0,%r2
2160	STREG	%r2,TASK_PT_SR0(%r1)
2161
2162	/* Save the scratch sr */
2163	mfsp	%sr1,%r2
2164	STREG	%r2,TASK_PT_SR1(%r1)
2165
2166	/* sr2 should be set to zero for userspace syscalls */
2167	STREG	%r0,TASK_PT_SR2(%r1)
2168
2169pt_regs_ok:
2170	LDREG	TASK_PT_GR31(%r1),%r2
2171	depi	3,31,2,%r2			   /* ensure return to user mode. */
2172	STREG	%r2,TASK_PT_IAOQ0(%r1)
2173	ldo	4(%r2),%r2
2174	STREG	%r2,TASK_PT_IAOQ1(%r1)
2175	copy	%r25,%r16
2176	b	intr_restore
2177	nop
2178
2179	.import schedule,code
2180syscall_do_resched:
2181	BL	schedule,%r2
2182#ifdef CONFIG_64BIT
2183	ldo	-16(%r30),%r29		/* Reference param save area */
2184#else
2185	nop
2186#endif
2187	b	syscall_check_resched	/* if resched, we start over again */
2188	nop
2189ENDPROC(syscall_exit)
2190
2191
2192#ifdef CONFIG_FUNCTION_TRACER
2193	.import ftrace_function_trampoline,code
2194ENTRY(_mcount)
2195	copy	%r3, %arg2
2196	b	ftrace_function_trampoline
2197	nop
2198ENDPROC(_mcount)
2199
2200ENTRY(return_to_handler)
2201	load32	return_trampoline, %rp
2202	copy	%ret0, %arg0
2203	copy	%ret1, %arg1
2204	b	ftrace_return_to_handler
2205	nop
2206return_trampoline:
2207	copy	%ret0, %rp
2208	copy	%r23, %ret0
2209	copy	%r24, %ret1
2210
2211.globl ftrace_stub
2212ftrace_stub:
2213	bv	%r0(%rp)
2214	nop
2215ENDPROC(return_to_handler)
2216#endif	/* CONFIG_FUNCTION_TRACER */
2217
2218
2219get_register:
2220	/*
2221	 * get_register is used by the non access tlb miss handlers to
2222	 * copy the value of the general register specified in r8 into
2223	 * r1. This routine can't be used for shadowed registers, since
2224	 * the rfir will restore the original value. So, for the shadowed
2225	 * registers we put a -1 into r1 to indicate that the register
2226	 * should not be used (the register being copied could also have
2227	 * a -1 in it, but that is OK, it just means that we will have
2228	 * to use the slow path instead).
2229	 */
2230	blr     %r8,%r0
2231	nop
2232	bv      %r0(%r25)    /* r0 */
2233	copy    %r0,%r1
2234	bv      %r0(%r25)    /* r1 - shadowed */
2235	ldi     -1,%r1
2236	bv      %r0(%r25)    /* r2 */
2237	copy    %r2,%r1
2238	bv      %r0(%r25)    /* r3 */
2239	copy    %r3,%r1
2240	bv      %r0(%r25)    /* r4 */
2241	copy    %r4,%r1
2242	bv      %r0(%r25)    /* r5 */
2243	copy    %r5,%r1
2244	bv      %r0(%r25)    /* r6 */
2245	copy    %r6,%r1
2246	bv      %r0(%r25)    /* r7 */
2247	copy    %r7,%r1
2248	bv      %r0(%r25)    /* r8 - shadowed */
2249	ldi     -1,%r1
2250	bv      %r0(%r25)    /* r9 - shadowed */
2251	ldi     -1,%r1
2252	bv      %r0(%r25)    /* r10 */
2253	copy    %r10,%r1
2254	bv      %r0(%r25)    /* r11 */
2255	copy    %r11,%r1
2256	bv      %r0(%r25)    /* r12 */
2257	copy    %r12,%r1
2258	bv      %r0(%r25)    /* r13 */
2259	copy    %r13,%r1
2260	bv      %r0(%r25)    /* r14 */
2261	copy    %r14,%r1
2262	bv      %r0(%r25)    /* r15 */
2263	copy    %r15,%r1
2264	bv      %r0(%r25)    /* r16 - shadowed */
2265	ldi     -1,%r1
2266	bv      %r0(%r25)    /* r17 - shadowed */
2267	ldi     -1,%r1
2268	bv      %r0(%r25)    /* r18 */
2269	copy    %r18,%r1
2270	bv      %r0(%r25)    /* r19 */
2271	copy    %r19,%r1
2272	bv      %r0(%r25)    /* r20 */
2273	copy    %r20,%r1
2274	bv      %r0(%r25)    /* r21 */
2275	copy    %r21,%r1
2276	bv      %r0(%r25)    /* r22 */
2277	copy    %r22,%r1
2278	bv      %r0(%r25)    /* r23 */
2279	copy    %r23,%r1
2280	bv      %r0(%r25)    /* r24 - shadowed */
2281	ldi     -1,%r1
2282	bv      %r0(%r25)    /* r25 - shadowed */
2283	ldi     -1,%r1
2284	bv      %r0(%r25)    /* r26 */
2285	copy    %r26,%r1
2286	bv      %r0(%r25)    /* r27 */
2287	copy    %r27,%r1
2288	bv      %r0(%r25)    /* r28 */
2289	copy    %r28,%r1
2290	bv      %r0(%r25)    /* r29 */
2291	copy    %r29,%r1
2292	bv      %r0(%r25)    /* r30 */
2293	copy    %r30,%r1
2294	bv      %r0(%r25)    /* r31 */
2295	copy    %r31,%r1
2296
2297
2298set_register:
2299	/*
2300	 * set_register is used by the non access tlb miss handlers to
2301	 * copy the value of r1 into the general register specified in
2302	 * r8.
2303	 */
2304	blr     %r8,%r0
2305	nop
2306	bv      %r0(%r25)    /* r0 (silly, but it is a place holder) */
2307	copy    %r1,%r0
2308	bv      %r0(%r25)    /* r1 */
2309	copy    %r1,%r1
2310	bv      %r0(%r25)    /* r2 */
2311	copy    %r1,%r2
2312	bv      %r0(%r25)    /* r3 */
2313	copy    %r1,%r3
2314	bv      %r0(%r25)    /* r4 */
2315	copy    %r1,%r4
2316	bv      %r0(%r25)    /* r5 */
2317	copy    %r1,%r5
2318	bv      %r0(%r25)    /* r6 */
2319	copy    %r1,%r6
2320	bv      %r0(%r25)    /* r7 */
2321	copy    %r1,%r7
2322	bv      %r0(%r25)    /* r8 */
2323	copy    %r1,%r8
2324	bv      %r0(%r25)    /* r9 */
2325	copy    %r1,%r9
2326	bv      %r0(%r25)    /* r10 */
2327	copy    %r1,%r10
2328	bv      %r0(%r25)    /* r11 */
2329	copy    %r1,%r11
2330	bv      %r0(%r25)    /* r12 */
2331	copy    %r1,%r12
2332	bv      %r0(%r25)    /* r13 */
2333	copy    %r1,%r13
2334	bv      %r0(%r25)    /* r14 */
2335	copy    %r1,%r14
2336	bv      %r0(%r25)    /* r15 */
2337	copy    %r1,%r15
2338	bv      %r0(%r25)    /* r16 */
2339	copy    %r1,%r16
2340	bv      %r0(%r25)    /* r17 */
2341	copy    %r1,%r17
2342	bv      %r0(%r25)    /* r18 */
2343	copy    %r1,%r18
2344	bv      %r0(%r25)    /* r19 */
2345	copy    %r1,%r19
2346	bv      %r0(%r25)    /* r20 */
2347	copy    %r1,%r20
2348	bv      %r0(%r25)    /* r21 */
2349	copy    %r1,%r21
2350	bv      %r0(%r25)    /* r22 */
2351	copy    %r1,%r22
2352	bv      %r0(%r25)    /* r23 */
2353	copy    %r1,%r23
2354	bv      %r0(%r25)    /* r24 */
2355	copy    %r1,%r24
2356	bv      %r0(%r25)    /* r25 */
2357	copy    %r1,%r25
2358	bv      %r0(%r25)    /* r26 */
2359	copy    %r1,%r26
2360	bv      %r0(%r25)    /* r27 */
2361	copy    %r1,%r27
2362	bv      %r0(%r25)    /* r28 */
2363	copy    %r1,%r28
2364	bv      %r0(%r25)    /* r29 */
2365	copy    %r1,%r29
2366	bv      %r0(%r25)    /* r30 */
2367	copy    %r1,%r30
2368	bv      %r0(%r25)    /* r31 */
2369	copy    %r1,%r31
2370
2371