xref: /openbmc/linux/arch/parisc/kernel/entry.S (revision dfd4f649)
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/ldcw.h>
39#include <asm/traps.h>
40#include <asm/thread_info.h>
41#include <asm/alternative.h>
42
43#include <linux/linkage.h>
44
45#ifdef CONFIG_64BIT
46	.level 2.0w
47#else
48	.level 2.0
49#endif
50
51	.import		pa_tlb_lock,data
52	.macro  load_pa_tlb_lock reg
53#if __PA_LDCW_ALIGNMENT > 4
54	load32	PA(pa_tlb_lock) + __PA_LDCW_ALIGNMENT-1, \reg
55	depi	0,31,__PA_LDCW_ALIGN_ORDER, \reg
56#else
57	load32	PA(pa_tlb_lock), \reg
58#endif
59	.endm
60
61	/* space_to_prot macro creates a prot id from a space id */
62
63#if (SPACEID_SHIFT) == 0
64	.macro  space_to_prot spc prot
65	depd,z  \spc,62,31,\prot
66	.endm
67#else
68	.macro  space_to_prot spc prot
69	extrd,u \spc,(64 - (SPACEID_SHIFT)),32,\prot
70	.endm
71#endif
72
73	/* Switch to virtual mapping, trashing only %r1 */
74	.macro  virt_map
75	/* pcxt_ssm_bug */
76	rsm	PSW_SM_I, %r0	/* barrier for "Relied upon Translation */
77	mtsp	%r0, %sr4
78	mtsp	%r0, %sr5
79	mtsp	%r0, %sr6
80	tovirt_r1 %r29
81	load32	KERNEL_PSW, %r1
82
83	rsm     PSW_SM_QUIET,%r0	/* second "heavy weight" ctl op */
84	mtctl	%r0, %cr17	/* Clear IIASQ tail */
85	mtctl	%r0, %cr17	/* Clear IIASQ head */
86	mtctl	%r1, %ipsw
87	load32	4f, %r1
88	mtctl	%r1, %cr18	/* Set IIAOQ tail */
89	ldo	4(%r1), %r1
90	mtctl	%r1, %cr18	/* Set IIAOQ head */
91	rfir
92	nop
934:
94	.endm
95
96	/*
97	 * The "get_stack" macros are responsible for determining the
98	 * kernel stack value.
99	 *
100	 *      If sr7 == 0
101	 *          Already using a kernel stack, so call the
102	 *          get_stack_use_r30 macro to push a pt_regs structure
103	 *          on the stack, and store registers there.
104	 *      else
105	 *          Need to set up a kernel stack, so call the
106	 *          get_stack_use_cr30 macro to set up a pointer
107	 *          to the pt_regs structure contained within the
108	 *          task pointer pointed to by cr30. Set the stack
109	 *          pointer to point to the end of the task structure.
110	 *
111	 * Note that we use shadowed registers for temps until
112	 * we can save %r26 and %r29. %r26 is used to preserve
113	 * %r8 (a shadowed register) which temporarily contained
114	 * either the fault type ("code") or the eirr. We need
115	 * to use a non-shadowed register to carry the value over
116	 * the rfir in virt_map. We use %r26 since this value winds
117	 * up being passed as the argument to either do_cpu_irq_mask
118	 * or handle_interruption. %r29 is used to hold a pointer
119	 * the register save area, and once again, it needs to
120	 * be a non-shadowed register so that it survives the rfir.
121	 *
122	 * N.B. TASK_SZ_ALGN and PT_SZ_ALGN include space for a stack frame.
123	 */
124
125	.macro  get_stack_use_cr30
126
127	/* we save the registers in the task struct */
128
129	copy	%r30, %r17
130	mfctl   %cr30, %r1
131	ldo	THREAD_SZ_ALGN(%r1), %r30
132	mtsp	%r0,%sr7
133	mtsp	%r16,%sr3
134	tophys  %r1,%r9
135	LDREG	TI_TASK(%r9), %r1	/* thread_info -> task_struct */
136	tophys  %r1,%r9
137	ldo     TASK_REGS(%r9),%r9
138	STREG   %r17,PT_GR30(%r9)
139	STREG   %r29,PT_GR29(%r9)
140	STREG   %r26,PT_GR26(%r9)
141	STREG	%r16,PT_SR7(%r9)
142	copy    %r9,%r29
143	.endm
144
145	.macro  get_stack_use_r30
146
147	/* we put a struct pt_regs on the stack and save the registers there */
148
149	tophys  %r30,%r9
150	copy	%r30,%r1
151	ldo	PT_SZ_ALGN(%r30),%r30
152	STREG   %r1,PT_GR30(%r9)
153	STREG   %r29,PT_GR29(%r9)
154	STREG   %r26,PT_GR26(%r9)
155	STREG	%r16,PT_SR7(%r9)
156	copy    %r9,%r29
157	.endm
158
159	.macro  rest_stack
160	LDREG   PT_GR1(%r29), %r1
161	LDREG   PT_GR30(%r29),%r30
162	LDREG   PT_GR29(%r29),%r29
163	.endm
164
165	/* default interruption handler
166	 * (calls traps.c:handle_interruption) */
167	.macro	def code
168	b	intr_save
169	ldi     \code, %r8
170	.align	32
171	.endm
172
173	/* Interrupt interruption handler
174	 * (calls irq.c:do_cpu_irq_mask) */
175	.macro	extint code
176	b	intr_extint
177	mfsp    %sr7,%r16
178	.align	32
179	.endm
180
181	.import	os_hpmc, code
182
183	/* HPMC handler */
184	.macro	hpmc code
185	nop			/* must be a NOP, will be patched later */
186	load32	PA(os_hpmc), %r3
187	bv,n	0(%r3)
188	nop
189	.word	0		/* checksum (will be patched) */
190	.word	0		/* address of handler */
191	.word	0		/* length of handler */
192	.endm
193
194	/*
195	 * Performance Note: Instructions will be moved up into
196	 * this part of the code later on, once we are sure
197	 * that the tlb miss handlers are close to final form.
198	 */
199
200	/* Register definitions for tlb miss handler macros */
201
202	va  = r8	/* virtual address for which the trap occurred */
203	spc = r24	/* space for which the trap occurred */
204
205#ifndef CONFIG_64BIT
206
207	/*
208	 * itlb miss interruption handler (parisc 1.1 - 32 bit)
209	 */
210
211	.macro	itlb_11 code
212
213	mfctl	%pcsq, spc
214	b	itlb_miss_11
215	mfctl	%pcoq, va
216
217	.align		32
218	.endm
219#endif
220
221	/*
222	 * itlb miss interruption handler (parisc 2.0)
223	 */
224
225	.macro	itlb_20 code
226	mfctl	%pcsq, spc
227#ifdef CONFIG_64BIT
228	b       itlb_miss_20w
229#else
230	b	itlb_miss_20
231#endif
232	mfctl	%pcoq, va
233
234	.align		32
235	.endm
236
237#ifndef CONFIG_64BIT
238	/*
239	 * naitlb miss interruption handler (parisc 1.1 - 32 bit)
240	 */
241
242	.macro	naitlb_11 code
243
244	mfctl	%isr,spc
245	b	naitlb_miss_11
246	mfctl 	%ior,va
247
248	.align		32
249	.endm
250#endif
251
252	/*
253	 * naitlb miss interruption handler (parisc 2.0)
254	 */
255
256	.macro	naitlb_20 code
257
258	mfctl	%isr,spc
259#ifdef CONFIG_64BIT
260	b       naitlb_miss_20w
261#else
262	b	naitlb_miss_20
263#endif
264	mfctl 	%ior,va
265
266	.align		32
267	.endm
268
269#ifndef CONFIG_64BIT
270	/*
271	 * dtlb miss interruption handler (parisc 1.1 - 32 bit)
272	 */
273
274	.macro	dtlb_11 code
275
276	mfctl	%isr, spc
277	b	dtlb_miss_11
278	mfctl	%ior, va
279
280	.align		32
281	.endm
282#endif
283
284	/*
285	 * dtlb miss interruption handler (parisc 2.0)
286	 */
287
288	.macro	dtlb_20 code
289
290	mfctl	%isr, spc
291#ifdef CONFIG_64BIT
292	b       dtlb_miss_20w
293#else
294	b	dtlb_miss_20
295#endif
296	mfctl	%ior, va
297
298	.align		32
299	.endm
300
301#ifndef CONFIG_64BIT
302	/* nadtlb miss interruption handler (parisc 1.1 - 32 bit) */
303
304	.macro	nadtlb_11 code
305
306	mfctl	%isr,spc
307	b       nadtlb_miss_11
308	mfctl	%ior,va
309
310	.align		32
311	.endm
312#endif
313
314	/* nadtlb miss interruption handler (parisc 2.0) */
315
316	.macro	nadtlb_20 code
317
318	mfctl	%isr,spc
319#ifdef CONFIG_64BIT
320	b       nadtlb_miss_20w
321#else
322	b       nadtlb_miss_20
323#endif
324	mfctl	%ior,va
325
326	.align		32
327	.endm
328
329#ifndef CONFIG_64BIT
330	/*
331	 * dirty bit trap interruption handler (parisc 1.1 - 32 bit)
332	 */
333
334	.macro	dbit_11 code
335
336	mfctl	%isr,spc
337	b	dbit_trap_11
338	mfctl	%ior,va
339
340	.align		32
341	.endm
342#endif
343
344	/*
345	 * dirty bit trap interruption handler (parisc 2.0)
346	 */
347
348	.macro	dbit_20 code
349
350	mfctl	%isr,spc
351#ifdef CONFIG_64BIT
352	b       dbit_trap_20w
353#else
354	b	dbit_trap_20
355#endif
356	mfctl	%ior,va
357
358	.align		32
359	.endm
360
361	/* In LP64, the space contains part of the upper 32 bits of the
362	 * fault.  We have to extract this and place it in the va,
363	 * zeroing the corresponding bits in the space register */
364	.macro		space_adjust	spc,va,tmp
365#ifdef CONFIG_64BIT
366	extrd,u		\spc,63,SPACEID_SHIFT,\tmp
367	depd		%r0,63,SPACEID_SHIFT,\spc
368	depd		\tmp,31,SPACEID_SHIFT,\va
369#endif
370	.endm
371
372	.import		swapper_pg_dir,code
373
374	/* Get the pgd.  For faults on space zero (kernel space), this
375	 * is simply swapper_pg_dir.  For user space faults, the
376	 * pgd is stored in %cr25 */
377	.macro		get_pgd		spc,reg
378	ldil		L%PA(swapper_pg_dir),\reg
379	ldo		R%PA(swapper_pg_dir)(\reg),\reg
380	or,COND(=)	%r0,\spc,%r0
381	mfctl		%cr25,\reg
382	.endm
383
384	/*
385		space_check(spc,tmp,fault)
386
387		spc - The space we saw the fault with.
388		tmp - The place to store the current space.
389		fault - Function to call on failure.
390
391		Only allow faults on different spaces from the
392		currently active one if we're the kernel
393
394	*/
395	.macro		space_check	spc,tmp,fault
396	mfsp		%sr7,\tmp
397	/* check against %r0 which is same value as LINUX_GATEWAY_SPACE */
398	or,COND(<>)	%r0,\spc,%r0	/* user may execute gateway page
399					 * as kernel, so defeat the space
400					 * check if it is */
401	copy		\spc,\tmp
402	or,COND(=)	%r0,\tmp,%r0	/* nullify if executing as kernel */
403	cmpb,COND(<>),n	\tmp,\spc,\fault
404	.endm
405
406	/* Look up a PTE in a 2-Level scheme (faulting at each
407	 * level if the entry isn't present
408	 *
409	 * NOTE: we use ldw even for LP64, since the short pointers
410	 * can address up to 1TB
411	 */
412	.macro		L2_ptep	pmd,pte,index,va,fault
413#if CONFIG_PGTABLE_LEVELS == 3
414	extru		\va,31-ASM_PMD_SHIFT,ASM_BITS_PER_PMD,\index
415#else
416# if defined(CONFIG_64BIT)
417	extrd,u		\va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
418  #else
419  # if PAGE_SIZE > 4096
420	extru		\va,31-ASM_PGDIR_SHIFT,32-ASM_PGDIR_SHIFT,\index
421  # else
422	extru		\va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
423  # endif
424# endif
425#endif
426	dep             %r0,31,PAGE_SHIFT,\pmd  /* clear offset */
427	copy		%r0,\pte
428	ldw,s		\index(\pmd),\pmd
429	bb,>=,n		\pmd,_PxD_PRESENT_BIT,\fault
430	dep		%r0,31,PxD_FLAG_SHIFT,\pmd /* clear flags */
431	SHLREG		\pmd,PxD_VALUE_SHIFT,\pmd
432	extru		\va,31-PAGE_SHIFT,ASM_BITS_PER_PTE,\index
433	dep		%r0,31,PAGE_SHIFT,\pmd  /* clear offset */
434	shladd		\index,BITS_PER_PTE_ENTRY,\pmd,\pmd /* pmd is now pte */
435	.endm
436
437	/* Look up PTE in a 3-Level scheme.
438	 *
439	 * Here we implement a Hybrid L2/L3 scheme: we allocate the
440	 * first pmd adjacent to the pgd.  This means that we can
441	 * subtract a constant offset to get to it.  The pmd and pgd
442	 * sizes are arranged so that a single pmd covers 4GB (giving
443	 * a full LP64 process access to 8TB) so our lookups are
444	 * effectively L2 for the first 4GB of the kernel (i.e. for
445	 * all ILP32 processes and all the kernel for machines with
446	 * under 4GB of memory) */
447	.macro		L3_ptep pgd,pte,index,va,fault
448#if CONFIG_PGTABLE_LEVELS == 3 /* we might have a 2-Level scheme, e.g. with 16kb page size */
449	extrd,u		\va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
450	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
451	ldw,s		\index(\pgd),\pgd
452	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
453	bb,>=,n		\pgd,_PxD_PRESENT_BIT,\fault
454	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
455	shld		\pgd,PxD_VALUE_SHIFT,\index
456	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
457	copy		\index,\pgd
458	extrd,u,*<>	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
459	ldo		ASM_PGD_PMD_OFFSET(\pgd),\pgd
460#endif
461	L2_ptep		\pgd,\pte,\index,\va,\fault
462	.endm
463
464	/* Acquire pa_tlb_lock lock and check page is present. */
465	.macro		tlb_lock	spc,ptp,pte,tmp,tmp1,fault
466#ifdef CONFIG_SMP
46798:	cmpib,COND(=),n	0,\spc,2f
468	load_pa_tlb_lock \tmp
4691:	LDCW		0(\tmp),\tmp1
470	cmpib,COND(=)	0,\tmp1,1b
471	nop
472	LDREG		0(\ptp),\pte
473	bb,<,n		\pte,_PAGE_PRESENT_BIT,3f
474	b		\fault
475	stw,ma		\spc,0(\tmp)
47699:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
477#endif
4782:	LDREG		0(\ptp),\pte
479	bb,>=,n		\pte,_PAGE_PRESENT_BIT,\fault
4803:
481	.endm
482
483	/* Release pa_tlb_lock lock without reloading lock address. */
484	.macro		tlb_unlock0	spc,tmp
485#ifdef CONFIG_SMP
48698:	or,COND(=)	%r0,\spc,%r0
487	stw,ma		\spc,0(\tmp)
48899:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
489#endif
490	.endm
491
492	/* Release pa_tlb_lock lock. */
493	.macro		tlb_unlock1	spc,tmp
494#ifdef CONFIG_SMP
49598:	load_pa_tlb_lock \tmp
49699:	ALTERNATIVE(98b, 99b, ALT_COND_NO_SMP, INSN_NOP)
497	tlb_unlock0	\spc,\tmp
498#endif
499	.endm
500
501	/* Set the _PAGE_ACCESSED bit of the PTE.  Be clever and
502	 * don't needlessly dirty the cache line if it was already set */
503	.macro		update_accessed	ptp,pte,tmp,tmp1
504	ldi		_PAGE_ACCESSED,\tmp1
505	or		\tmp1,\pte,\tmp
506	and,COND(<>)	\tmp1,\pte,%r0
507	STREG		\tmp,0(\ptp)
508	.endm
509
510	/* Set the dirty bit (and accessed bit).  No need to be
511	 * clever, this is only used from the dirty fault */
512	.macro		update_dirty	ptp,pte,tmp
513	ldi		_PAGE_ACCESSED|_PAGE_DIRTY,\tmp
514	or		\tmp,\pte,\pte
515	STREG		\pte,0(\ptp)
516	.endm
517
518	/* We have (depending on the page size):
519	 * - 38 to 52-bit Physical Page Number
520	 * - 12 to 26-bit page offset
521	 */
522	/* bitshift difference between a PFN (based on kernel's PAGE_SIZE)
523	 * to a CPU TLB 4k PFN (4k => 12 bits to shift) */
524	#define PAGE_ADD_SHIFT		(PAGE_SHIFT-12)
525	#define PAGE_ADD_HUGE_SHIFT	(REAL_HPAGE_SHIFT-12)
526
527	/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
528	.macro		convert_for_tlb_insert20 pte,tmp
529#ifdef CONFIG_HUGETLB_PAGE
530	copy		\pte,\tmp
531	extrd,u		\tmp,(63-ASM_PFN_PTE_SHIFT)+(63-58)+PAGE_ADD_SHIFT,\
532				64-PAGE_SHIFT-PAGE_ADD_SHIFT,\pte
533
534	depdi		_PAGE_SIZE_ENCODING_DEFAULT,63,\
535				(63-58)+PAGE_ADD_SHIFT,\pte
536	extrd,u,*=	\tmp,_PAGE_HPAGE_BIT+32,1,%r0
537	depdi		_HUGE_PAGE_SIZE_ENCODING_DEFAULT,63,\
538				(63-58)+PAGE_ADD_HUGE_SHIFT,\pte
539#else /* Huge pages disabled */
540	extrd,u		\pte,(63-ASM_PFN_PTE_SHIFT)+(63-58)+PAGE_ADD_SHIFT,\
541				64-PAGE_SHIFT-PAGE_ADD_SHIFT,\pte
542	depdi		_PAGE_SIZE_ENCODING_DEFAULT,63,\
543				(63-58)+PAGE_ADD_SHIFT,\pte
544#endif
545	.endm
546
547	/* Convert the pte and prot to tlb insertion values.  How
548	 * this happens is quite subtle, read below */
549	.macro		make_insert_tlb	spc,pte,prot,tmp
550	space_to_prot   \spc \prot        /* create prot id from space */
551	/* The following is the real subtlety.  This is depositing
552	 * T <-> _PAGE_REFTRAP
553	 * D <-> _PAGE_DIRTY
554	 * B <-> _PAGE_DMB (memory break)
555	 *
556	 * Then incredible subtlety: The access rights are
557	 * _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE
558	 * See 3-14 of the parisc 2.0 manual
559	 *
560	 * Finally, _PAGE_READ goes in the top bit of PL1 (so we
561	 * trigger an access rights trap in user space if the user
562	 * tries to read an unreadable page */
563	depd            \pte,8,7,\prot
564
565	/* PAGE_USER indicates the page can be read with user privileges,
566	 * so deposit X1|11 to PL1|PL2 (remember the upper bit of PL1
567	 * contains _PAGE_READ) */
568	extrd,u,*=      \pte,_PAGE_USER_BIT+32,1,%r0
569	depdi		7,11,3,\prot
570	/* If we're a gateway page, drop PL2 back to zero for promotion
571	 * to kernel privilege (so we can execute the page as kernel).
572	 * Any privilege promotion page always denys read and write */
573	extrd,u,*= 	\pte,_PAGE_GATEWAY_BIT+32,1,%r0
574	depd		%r0,11,2,\prot	/* If Gateway, Set PL2 to 0 */
575
576	/* Enforce uncacheable pages.
577	 * This should ONLY be use for MMIO on PA 2.0 machines.
578	 * Memory/DMA is cache coherent on all PA2.0 machines we support
579	 * (that means T-class is NOT supported) and the memory controllers
580	 * on most of those machines only handles cache transactions.
581	 */
582	extrd,u,*=	\pte,_PAGE_NO_CACHE_BIT+32,1,%r0
583	depdi		1,12,1,\prot
584
585	/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
586	convert_for_tlb_insert20 \pte \tmp
587	.endm
588
589	/* Identical macro to make_insert_tlb above, except it
590	 * makes the tlb entry for the differently formatted pa11
591	 * insertion instructions */
592	.macro		make_insert_tlb_11	spc,pte,prot
593	zdep		\spc,30,15,\prot
594	dep		\pte,8,7,\prot
595	extru,=		\pte,_PAGE_NO_CACHE_BIT,1,%r0
596	depi		1,12,1,\prot
597	extru,=         \pte,_PAGE_USER_BIT,1,%r0
598	depi		7,11,3,\prot   /* Set for user space (1 rsvd for read) */
599	extru,= 	\pte,_PAGE_GATEWAY_BIT,1,%r0
600	depi		0,11,2,\prot	/* If Gateway, Set PL2 to 0 */
601
602	/* Get rid of prot bits and convert to page addr for iitlba */
603
604	depi		0,31,ASM_PFN_PTE_SHIFT,\pte
605	SHRREG		\pte,(ASM_PFN_PTE_SHIFT-(31-26)),\pte
606	.endm
607
608	/* This is for ILP32 PA2.0 only.  The TLB insertion needs
609	 * to extend into I/O space if the address is 0xfXXXXXXX
610	 * so we extend the f's into the top word of the pte in
611	 * this case */
612	.macro		f_extend	pte,tmp
613	extrd,s		\pte,42,4,\tmp
614	addi,<>		1,\tmp,%r0
615	extrd,s		\pte,63,25,\pte
616	.endm
617
618	/* The alias region is an 8MB aligned 16MB to do clear and
619	 * copy user pages at addresses congruent with the user
620	 * virtual address.
621	 *
622	 * To use the alias page, you set %r26 up with the to TLB
623	 * entry (identifying the physical page) and %r23 up with
624	 * the from tlb entry (or nothing if only a to entry---for
625	 * clear_user_page_asm) */
626	.macro		do_alias	spc,tmp,tmp1,va,pte,prot,fault,patype
627	cmpib,COND(<>),n 0,\spc,\fault
628	ldil		L%(TMPALIAS_MAP_START),\tmp
629#if defined(CONFIG_64BIT) && (TMPALIAS_MAP_START >= 0x80000000)
630	/* on LP64, ldi will sign extend into the upper 32 bits,
631	 * which is behaviour we don't want */
632	depdi		0,31,32,\tmp
633#endif
634	copy		\va,\tmp1
635	depi		0,31,23,\tmp1
636	cmpb,COND(<>),n	\tmp,\tmp1,\fault
637	mfctl		%cr19,\tmp	/* iir */
638	/* get the opcode (first six bits) into \tmp */
639	extrw,u		\tmp,5,6,\tmp
640	/*
641	 * Only setting the T bit prevents data cache movein
642	 * Setting access rights to zero prevents instruction cache movein
643	 *
644	 * Note subtlety here: _PAGE_GATEWAY, _PAGE_EXEC and _PAGE_WRITE go
645	 * to type field and _PAGE_READ goes to top bit of PL1
646	 */
647	ldi		(_PAGE_REFTRAP|_PAGE_READ|_PAGE_WRITE),\prot
648	/*
649	 * so if the opcode is one (i.e. this is a memory management
650	 * instruction) nullify the next load so \prot is only T.
651	 * Otherwise this is a normal data operation
652	 */
653	cmpiclr,=	0x01,\tmp,%r0
654	ldi		(_PAGE_DIRTY|_PAGE_READ|_PAGE_WRITE),\prot
655.ifc \patype,20
656	depd,z		\prot,8,7,\prot
657.else
658.ifc \patype,11
659	depw,z		\prot,8,7,\prot
660.else
661	.error "undefined PA type to do_alias"
662.endif
663.endif
664	/*
665	 * OK, it is in the temp alias region, check whether "from" or "to".
666	 * Check "subtle" note in pacache.S re: r23/r26.
667	 */
668#ifdef CONFIG_64BIT
669	extrd,u,*=	\va,41,1,%r0
670#else
671	extrw,u,=	\va,9,1,%r0
672#endif
673	or,COND(tr)	%r23,%r0,\pte
674	or		%r26,%r0,\pte
675	.endm
676
677
678	/*
679	 * Fault_vectors are architecturally required to be aligned on a 2K
680	 * boundary
681	 */
682
683	.section .text.hot
684	.align 2048
685
686ENTRY(fault_vector_20)
687	/* First vector is invalid (0) */
688	.ascii	"cows can fly"
689	.byte 0
690	.align 32
691
692	hpmc		 1
693	def		 2
694	def		 3
695	extint		 4
696	def		 5
697	itlb_20		 PARISC_ITLB_TRAP
698	def		 7
699	def		 8
700	def              9
701	def		10
702	def		11
703	def		12
704	def		13
705	def		14
706	dtlb_20		15
707	naitlb_20	16
708	nadtlb_20	17
709	def		18
710	def		19
711	dbit_20		20
712	def		21
713	def		22
714	def		23
715	def		24
716	def		25
717	def		26
718	def		27
719	def		28
720	def		29
721	def		30
722	def		31
723END(fault_vector_20)
724
725#ifndef CONFIG_64BIT
726
727	.align 2048
728
729ENTRY(fault_vector_11)
730	/* First vector is invalid (0) */
731	.ascii	"cows can fly"
732	.byte 0
733	.align 32
734
735	hpmc		 1
736	def		 2
737	def		 3
738	extint		 4
739	def		 5
740	itlb_11		 PARISC_ITLB_TRAP
741	def		 7
742	def		 8
743	def              9
744	def		10
745	def		11
746	def		12
747	def		13
748	def		14
749	dtlb_11		15
750	naitlb_11	16
751	nadtlb_11	17
752	def		18
753	def		19
754	dbit_11		20
755	def		21
756	def		22
757	def		23
758	def		24
759	def		25
760	def		26
761	def		27
762	def		28
763	def		29
764	def		30
765	def		31
766END(fault_vector_11)
767
768#endif
769	/* Fault vector is separately protected and *must* be on its own page */
770	.align		PAGE_SIZE
771
772	.import		handle_interruption,code
773	.import		do_cpu_irq_mask,code
774
775	/*
776	 * Child Returns here
777	 *
778	 * copy_thread moved args into task save area.
779	 */
780
781ENTRY(ret_from_kernel_thread)
782	/* Call schedule_tail first though */
783	BL	schedule_tail, %r2
784	nop
785
786	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
787	LDREG	TASK_PT_GR25(%r1), %r26
788#ifdef CONFIG_64BIT
789	LDREG	TASK_PT_GR27(%r1), %r27
790#endif
791	LDREG	TASK_PT_GR26(%r1), %r1
792	ble	0(%sr7, %r1)
793	copy	%r31, %r2
794	b	finish_child_return
795	nop
796END(ret_from_kernel_thread)
797
798
799	/*
800	 * struct task_struct *_switch_to(struct task_struct *prev,
801	 *	struct task_struct *next)
802	 *
803	 * switch kernel stacks and return prev */
804ENTRY_CFI(_switch_to)
805	STREG	 %r2, -RP_OFFSET(%r30)
806
807	callee_save_float
808	callee_save
809
810	load32	_switch_to_ret, %r2
811
812	STREG	%r2, TASK_PT_KPC(%r26)
813	LDREG	TASK_PT_KPC(%r25), %r2
814
815	STREG	%r30, TASK_PT_KSP(%r26)
816	LDREG	TASK_PT_KSP(%r25), %r30
817	LDREG	TASK_THREAD_INFO(%r25), %r25
818	bv	%r0(%r2)
819	mtctl   %r25,%cr30
820
821ENTRY(_switch_to_ret)
822	mtctl	%r0, %cr0		/* Needed for single stepping */
823	callee_rest
824	callee_rest_float
825
826	LDREG	-RP_OFFSET(%r30), %r2
827	bv	%r0(%r2)
828	copy	%r26, %r28
829ENDPROC_CFI(_switch_to)
830
831	/*
832	 * Common rfi return path for interruptions, kernel execve, and
833	 * sys_rt_sigreturn (sometimes).  The sys_rt_sigreturn syscall will
834	 * return via this path if the signal was received when the process
835	 * was running; if the process was blocked on a syscall then the
836	 * normal syscall_exit path is used.  All syscalls for traced
837	 * proceses exit via intr_restore.
838	 *
839	 * XXX If any syscalls that change a processes space id ever exit
840	 * this way, then we will need to copy %sr3 in to PT_SR[3..7], and
841	 * adjust IASQ[0..1].
842	 *
843	 */
844
845	.align	PAGE_SIZE
846
847ENTRY_CFI(syscall_exit_rfi)
848	mfctl   %cr30,%r16
849	LDREG	TI_TASK(%r16), %r16	/* thread_info -> task_struct */
850	ldo	TASK_REGS(%r16),%r16
851	/* Force iaoq to userspace, as the user has had access to our current
852	 * context via sigcontext. Also Filter the PSW for the same reason.
853	 */
854	LDREG	PT_IAOQ0(%r16),%r19
855	depi	3,31,2,%r19
856	STREG	%r19,PT_IAOQ0(%r16)
857	LDREG	PT_IAOQ1(%r16),%r19
858	depi	3,31,2,%r19
859	STREG	%r19,PT_IAOQ1(%r16)
860	LDREG   PT_PSW(%r16),%r19
861	load32	USER_PSW_MASK,%r1
862#ifdef CONFIG_64BIT
863	load32	USER_PSW_HI_MASK,%r20
864	depd    %r20,31,32,%r1
865#endif
866	and     %r19,%r1,%r19 /* Mask out bits that user shouldn't play with */
867	load32	USER_PSW,%r1
868	or      %r19,%r1,%r19 /* Make sure default USER_PSW bits are set */
869	STREG   %r19,PT_PSW(%r16)
870
871	/*
872	 * If we aren't being traced, we never saved space registers
873	 * (we don't store them in the sigcontext), so set them
874	 * to "proper" values now (otherwise we'll wind up restoring
875	 * whatever was last stored in the task structure, which might
876	 * be inconsistent if an interrupt occurred while on the gateway
877	 * page). Note that we may be "trashing" values the user put in
878	 * them, but we don't support the user changing them.
879	 */
880
881	STREG   %r0,PT_SR2(%r16)
882	mfsp    %sr3,%r19
883	STREG   %r19,PT_SR0(%r16)
884	STREG   %r19,PT_SR1(%r16)
885	STREG   %r19,PT_SR3(%r16)
886	STREG   %r19,PT_SR4(%r16)
887	STREG   %r19,PT_SR5(%r16)
888	STREG   %r19,PT_SR6(%r16)
889	STREG   %r19,PT_SR7(%r16)
890
891ENTRY(intr_return)
892	/* check for reschedule */
893	mfctl   %cr30,%r1
894	LDREG   TI_FLAGS(%r1),%r19	/* sched.h: TIF_NEED_RESCHED */
895	bb,<,n	%r19,31-TIF_NEED_RESCHED,intr_do_resched /* forward */
896
897	.import do_notify_resume,code
898intr_check_sig:
899	/* As above */
900	mfctl   %cr30,%r1
901	LDREG	TI_FLAGS(%r1),%r19
902	ldi	(_TIF_SIGPENDING|_TIF_NOTIFY_RESUME), %r20
903	and,COND(<>)	%r19, %r20, %r0
904	b,n	intr_restore	/* skip past if we've nothing to do */
905
906	/* This check is critical to having LWS
907	 * working. The IASQ is zero on the gateway
908	 * page and we cannot deliver any signals until
909	 * we get off the gateway page.
910	 *
911	 * Only do signals if we are returning to user space
912	 */
913	LDREG	PT_IASQ0(%r16), %r20
914	cmpib,COND(=),n LINUX_GATEWAY_SPACE, %r20, intr_restore /* backward */
915	LDREG	PT_IASQ1(%r16), %r20
916	cmpib,COND(=),n LINUX_GATEWAY_SPACE, %r20, intr_restore /* backward */
917
918	/* NOTE: We need to enable interrupts if we have to deliver
919	 * signals. We used to do this earlier but it caused kernel
920	 * stack overflows. */
921	ssm     PSW_SM_I, %r0
922
923	copy	%r0, %r25			/* long in_syscall = 0 */
924#ifdef CONFIG_64BIT
925	ldo	-16(%r30),%r29			/* Reference param save area */
926#endif
927
928	BL	do_notify_resume,%r2
929	copy	%r16, %r26			/* struct pt_regs *regs */
930
931	b,n	intr_check_sig
932
933intr_restore:
934	copy            %r16,%r29
935	ldo             PT_FR31(%r29),%r1
936	rest_fp         %r1
937	rest_general    %r29
938
939	/* inverse of virt_map */
940	pcxt_ssm_bug
941	rsm             PSW_SM_QUIET,%r0	/* prepare for rfi */
942	tophys_r1       %r29
943
944	/* Restore space id's and special cr's from PT_REGS
945	 * structure pointed to by r29
946	 */
947	rest_specials	%r29
948
949	/* IMPORTANT: rest_stack restores r29 last (we are using it)!
950	 * It also restores r1 and r30.
951	 */
952	rest_stack
953
954	rfi
955	nop
956
957#ifndef CONFIG_PREEMPT
958# define intr_do_preempt	intr_restore
959#endif /* !CONFIG_PREEMPT */
960
961	.import schedule,code
962intr_do_resched:
963	/* Only call schedule on return to userspace. If we're returning
964	 * to kernel space, we may schedule if CONFIG_PREEMPT, otherwise
965	 * we jump back to intr_restore.
966	 */
967	LDREG	PT_IASQ0(%r16), %r20
968	cmpib,COND(=)	0, %r20, intr_do_preempt
969	nop
970	LDREG	PT_IASQ1(%r16), %r20
971	cmpib,COND(=)	0, %r20, intr_do_preempt
972	nop
973
974	/* NOTE: We need to enable interrupts if we schedule.  We used
975	 * to do this earlier but it caused kernel stack overflows. */
976	ssm     PSW_SM_I, %r0
977
978#ifdef CONFIG_64BIT
979	ldo	-16(%r30),%r29		/* Reference param save area */
980#endif
981
982	ldil	L%intr_check_sig, %r2
983#ifndef CONFIG_64BIT
984	b	schedule
985#else
986	load32	schedule, %r20
987	bv	%r0(%r20)
988#endif
989	ldo	R%intr_check_sig(%r2), %r2
990
991	/* preempt the current task on returning to kernel
992	 * mode from an interrupt, iff need_resched is set,
993	 * and preempt_count is 0. otherwise, we continue on
994	 * our merry way back to the current running task.
995	 */
996#ifdef CONFIG_PREEMPT
997	.import preempt_schedule_irq,code
998intr_do_preempt:
999	rsm	PSW_SM_I, %r0		/* disable interrupts */
1000
1001	/* current_thread_info()->preempt_count */
1002	mfctl	%cr30, %r1
1003	LDREG	TI_PRE_COUNT(%r1), %r19
1004	cmpib,COND(<>)	0, %r19, intr_restore	/* if preempt_count > 0 */
1005	nop				/* prev insn branched backwards */
1006
1007	/* check if we interrupted a critical path */
1008	LDREG	PT_PSW(%r16), %r20
1009	bb,<,n	%r20, 31 - PSW_SM_I, intr_restore
1010	nop
1011
1012	BL	preempt_schedule_irq, %r2
1013	nop
1014
1015	b,n	intr_restore		/* ssm PSW_SM_I done by intr_restore */
1016#endif /* CONFIG_PREEMPT */
1017
1018	/*
1019	 * External interrupts.
1020	 */
1021
1022intr_extint:
1023	cmpib,COND(=),n 0,%r16,1f
1024
1025	get_stack_use_cr30
1026	b,n 2f
1027
10281:
1029	get_stack_use_r30
10302:
1031	save_specials	%r29
1032	virt_map
1033	save_general	%r29
1034
1035	ldo	PT_FR0(%r29), %r24
1036	save_fp	%r24
1037
1038	loadgp
1039
1040	copy	%r29, %r26	/* arg0 is pt_regs */
1041	copy	%r29, %r16	/* save pt_regs */
1042
1043	ldil	L%intr_return, %r2
1044
1045#ifdef CONFIG_64BIT
1046	ldo	-16(%r30),%r29	/* Reference param save area */
1047#endif
1048
1049	b	do_cpu_irq_mask
1050	ldo	R%intr_return(%r2), %r2	/* return to intr_return, not here */
1051ENDPROC_CFI(syscall_exit_rfi)
1052
1053
1054	/* Generic interruptions (illegal insn, unaligned, page fault, etc) */
1055
1056ENTRY_CFI(intr_save)		/* for os_hpmc */
1057	mfsp    %sr7,%r16
1058	cmpib,COND(=),n 0,%r16,1f
1059	get_stack_use_cr30
1060	b	2f
1061	copy    %r8,%r26
1062
10631:
1064	get_stack_use_r30
1065	copy    %r8,%r26
1066
10672:
1068	save_specials	%r29
1069
1070	/* If this trap is a itlb miss, skip saving/adjusting isr/ior */
1071	cmpib,COND(=),n        PARISC_ITLB_TRAP,%r26,skip_save_ior
1072
1073
1074	mfctl           %isr, %r16
1075	nop		/* serialize mfctl on PA 2.0 to avoid 4 cycle penalty */
1076	mfctl           %ior, %r17
1077
1078
1079#ifdef CONFIG_64BIT
1080	/*
1081	 * If the interrupted code was running with W bit off (32 bit),
1082	 * clear the b bits (bits 0 & 1) in the ior.
1083	 * save_specials left ipsw value in r8 for us to test.
1084	 */
1085	extrd,u,*<>     %r8,PSW_W_BIT,1,%r0
1086	depdi           0,1,2,%r17
1087
1088	/* adjust isr/ior: get high bits from isr and deposit in ior */
1089	space_adjust	%r16,%r17,%r1
1090#endif
1091	STREG           %r16, PT_ISR(%r29)
1092	STREG           %r17, PT_IOR(%r29)
1093
1094#if 0 && defined(CONFIG_64BIT)
1095	/* Revisit when we have 64-bit code above 4Gb */
1096	b,n		intr_save2
1097
1098skip_save_ior:
1099	/* We have a itlb miss, and when executing code above 4 Gb on ILP64, we
1100	 * need to adjust iasq/iaoq here in the same way we adjusted isr/ior
1101	 * above.
1102	 */
1103	extrd,u,*	%r8,PSW_W_BIT,1,%r1
1104	cmpib,COND(=),n	1,%r1,intr_save2
1105	LDREG		PT_IASQ0(%r29), %r16
1106	LDREG		PT_IAOQ0(%r29), %r17
1107	/* adjust iasq/iaoq */
1108	space_adjust	%r16,%r17,%r1
1109	STREG           %r16, PT_IASQ0(%r29)
1110	STREG           %r17, PT_IAOQ0(%r29)
1111#else
1112skip_save_ior:
1113#endif
1114
1115intr_save2:
1116	virt_map
1117	save_general	%r29
1118
1119	ldo		PT_FR0(%r29), %r25
1120	save_fp		%r25
1121
1122	loadgp
1123
1124	copy		%r29, %r25	/* arg1 is pt_regs */
1125#ifdef CONFIG_64BIT
1126	ldo		-16(%r30),%r29	/* Reference param save area */
1127#endif
1128
1129	ldil		L%intr_check_sig, %r2
1130	copy		%r25, %r16	/* save pt_regs */
1131
1132	b		handle_interruption
1133	ldo		R%intr_check_sig(%r2), %r2
1134ENDPROC_CFI(intr_save)
1135
1136
1137	/*
1138	 * Note for all tlb miss handlers:
1139	 *
1140	 * cr24 contains a pointer to the kernel address space
1141	 * page directory.
1142	 *
1143	 * cr25 contains a pointer to the current user address
1144	 * space page directory.
1145	 *
1146	 * sr3 will contain the space id of the user address space
1147	 * of the current running thread while that thread is
1148	 * running in the kernel.
1149	 */
1150
1151	/*
1152	 * register number allocations.  Note that these are all
1153	 * in the shadowed registers
1154	 */
1155
1156	t0 = r1		/* temporary register 0 */
1157	va = r8		/* virtual address for which the trap occurred */
1158	t1 = r9		/* temporary register 1 */
1159	pte  = r16	/* pte/phys page # */
1160	prot = r17	/* prot bits */
1161	spc  = r24	/* space for which the trap occurred */
1162	ptp = r25	/* page directory/page table pointer */
1163
1164#ifdef CONFIG_64BIT
1165
1166dtlb_miss_20w:
1167	space_adjust	spc,va,t0
1168	get_pgd		spc,ptp
1169	space_check	spc,t0,dtlb_fault
1170
1171	L3_ptep		ptp,pte,t0,va,dtlb_check_alias_20w
1172
1173	tlb_lock	spc,ptp,pte,t0,t1,dtlb_check_alias_20w
1174	update_accessed	ptp,pte,t0,t1
1175
1176	make_insert_tlb	spc,pte,prot,t1
1177
1178	idtlbt          pte,prot
1179
1180	tlb_unlock1	spc,t0
1181	rfir
1182	nop
1183
1184dtlb_check_alias_20w:
1185	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault,20
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	tlb_lock	spc,ptp,pte,t0,t1,nadtlb_check_alias_20w
1200	update_accessed	ptp,pte,t0,t1
1201
1202	make_insert_tlb	spc,pte,prot,t1
1203
1204	idtlbt          pte,prot
1205
1206	tlb_unlock1	spc,t0
1207	rfir
1208	nop
1209
1210nadtlb_check_alias_20w:
1211	do_alias	spc,t0,t1,va,pte,prot,nadtlb_emulate,20
1212
1213	idtlbt          pte,prot
1214
1215	rfir
1216	nop
1217
1218#else
1219
1220dtlb_miss_11:
1221	get_pgd		spc,ptp
1222
1223	space_check	spc,t0,dtlb_fault
1224
1225	L2_ptep		ptp,pte,t0,va,dtlb_check_alias_11
1226
1227	tlb_lock	spc,ptp,pte,t0,t1,dtlb_check_alias_11
1228	update_accessed	ptp,pte,t0,t1
1229
1230	make_insert_tlb_11	spc,pte,prot
1231
1232	mfsp		%sr1,t1  /* Save sr1 so we can use it in tlb inserts */
1233	mtsp		spc,%sr1
1234
1235	idtlba		pte,(%sr1,va)
1236	idtlbp		prot,(%sr1,va)
1237
1238	mtsp		t1, %sr1	/* Restore sr1 */
1239
1240	tlb_unlock1	spc,t0
1241	rfir
1242	nop
1243
1244dtlb_check_alias_11:
1245	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault,11
1246
1247	idtlba          pte,(va)
1248	idtlbp          prot,(va)
1249
1250	rfir
1251	nop
1252
1253nadtlb_miss_11:
1254	get_pgd		spc,ptp
1255
1256	space_check	spc,t0,nadtlb_fault
1257
1258	L2_ptep		ptp,pte,t0,va,nadtlb_check_alias_11
1259
1260	tlb_lock	spc,ptp,pte,t0,t1,nadtlb_check_alias_11
1261	update_accessed	ptp,pte,t0,t1
1262
1263	make_insert_tlb_11	spc,pte,prot
1264
1265	mfsp		%sr1,t1  /* Save sr1 so we can use it in tlb inserts */
1266	mtsp		spc,%sr1
1267
1268	idtlba		pte,(%sr1,va)
1269	idtlbp		prot,(%sr1,va)
1270
1271	mtsp		t1, %sr1	/* Restore sr1 */
1272
1273	tlb_unlock1	spc,t0
1274	rfir
1275	nop
1276
1277nadtlb_check_alias_11:
1278	do_alias	spc,t0,t1,va,pte,prot,nadtlb_emulate,11
1279
1280	idtlba          pte,(va)
1281	idtlbp          prot,(va)
1282
1283	rfir
1284	nop
1285
1286dtlb_miss_20:
1287	space_adjust	spc,va,t0
1288	get_pgd		spc,ptp
1289	space_check	spc,t0,dtlb_fault
1290
1291	L2_ptep		ptp,pte,t0,va,dtlb_check_alias_20
1292
1293	tlb_lock	spc,ptp,pte,t0,t1,dtlb_check_alias_20
1294	update_accessed	ptp,pte,t0,t1
1295
1296	make_insert_tlb	spc,pte,prot,t1
1297
1298	f_extend	pte,t1
1299
1300	idtlbt          pte,prot
1301
1302	tlb_unlock1	spc,t0
1303	rfir
1304	nop
1305
1306dtlb_check_alias_20:
1307	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault,20
1308
1309	idtlbt          pte,prot
1310
1311	rfir
1312	nop
1313
1314nadtlb_miss_20:
1315	get_pgd		spc,ptp
1316
1317	space_check	spc,t0,nadtlb_fault
1318
1319	L2_ptep		ptp,pte,t0,va,nadtlb_check_alias_20
1320
1321	tlb_lock	spc,ptp,pte,t0,t1,nadtlb_check_alias_20
1322	update_accessed	ptp,pte,t0,t1
1323
1324	make_insert_tlb	spc,pte,prot,t1
1325
1326	f_extend	pte,t1
1327
1328	idtlbt		pte,prot
1329
1330	tlb_unlock1	spc,t0
1331	rfir
1332	nop
1333
1334nadtlb_check_alias_20:
1335	do_alias	spc,t0,t1,va,pte,prot,nadtlb_emulate,20
1336
1337	idtlbt          pte,prot
1338
1339	rfir
1340	nop
1341
1342#endif
1343
1344nadtlb_emulate:
1345
1346	/*
1347	 * Non access misses can be caused by fdc,fic,pdc,lpa,probe and
1348	 * probei instructions. We don't want to fault for these
1349	 * instructions (not only does it not make sense, it can cause
1350	 * deadlocks, since some flushes are done with the mmap
1351	 * semaphore held). If the translation doesn't exist, we can't
1352	 * insert a translation, so have to emulate the side effects
1353	 * of the instruction. Since we don't insert a translation
1354	 * we can get a lot of faults during a flush loop, so it makes
1355	 * sense to try to do it here with minimum overhead. We only
1356	 * emulate fdc,fic,pdc,probew,prober instructions whose base
1357	 * and index registers are not shadowed. We defer everything
1358	 * else to the "slow" path.
1359	 */
1360
1361	mfctl           %cr19,%r9 /* Get iir */
1362
1363	/* PA 2.0 Arch Ref. Book pg 382 has a good description of the insn bits.
1364	   Checks for fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw */
1365
1366	/* Checks for fdc,fdce,pdc,"fic,4f" only */
1367	ldi             0x280,%r16
1368	and             %r9,%r16,%r17
1369	cmpb,<>,n       %r16,%r17,nadtlb_probe_check
1370	bb,>=,n         %r9,26,nadtlb_nullify  /* m bit not set, just nullify */
1371	BL		get_register,%r25
1372	extrw,u         %r9,15,5,%r8           /* Get index register # */
1373	cmpib,COND(=),n        -1,%r1,nadtlb_fault    /* have to use slow path */
1374	copy            %r1,%r24
1375	BL		get_register,%r25
1376	extrw,u         %r9,10,5,%r8           /* Get base register # */
1377	cmpib,COND(=),n        -1,%r1,nadtlb_fault    /* have to use slow path */
1378	BL		set_register,%r25
1379	add,l           %r1,%r24,%r1           /* doesn't affect c/b bits */
1380
1381nadtlb_nullify:
1382	mfctl           %ipsw,%r8
1383	ldil            L%PSW_N,%r9
1384	or              %r8,%r9,%r8            /* Set PSW_N */
1385	mtctl           %r8,%ipsw
1386
1387	rfir
1388	nop
1389
1390	/*
1391		When there is no translation for the probe address then we
1392		must nullify the insn and return zero in the target register.
1393		This will indicate to the calling code that it does not have
1394		write/read privileges to this address.
1395
1396		This should technically work for prober and probew in PA 1.1,
1397		and also probe,r and probe,w in PA 2.0
1398
1399		WARNING: USE ONLY NON-SHADOW REGISTERS WITH PROBE INSN!
1400		THE SLOW-PATH EMULATION HAS NOT BEEN WRITTEN YET.
1401
1402	*/
1403nadtlb_probe_check:
1404	ldi             0x80,%r16
1405	and             %r9,%r16,%r17
1406	cmpb,<>,n       %r16,%r17,nadtlb_fault /* Must be probe,[rw]*/
1407	BL              get_register,%r25      /* Find the target register */
1408	extrw,u         %r9,31,5,%r8           /* Get target register */
1409	cmpib,COND(=),n        -1,%r1,nadtlb_fault    /* have to use slow path */
1410	BL		set_register,%r25
1411	copy            %r0,%r1                /* Write zero to target register */
1412	b nadtlb_nullify                       /* Nullify return insn */
1413	nop
1414
1415
1416#ifdef CONFIG_64BIT
1417itlb_miss_20w:
1418
1419	/*
1420	 * I miss is a little different, since we allow users to fault
1421	 * on the gateway page which is in the kernel address space.
1422	 */
1423
1424	space_adjust	spc,va,t0
1425	get_pgd		spc,ptp
1426	space_check	spc,t0,itlb_fault
1427
1428	L3_ptep		ptp,pte,t0,va,itlb_fault
1429
1430	tlb_lock	spc,ptp,pte,t0,t1,itlb_fault
1431	update_accessed	ptp,pte,t0,t1
1432
1433	make_insert_tlb	spc,pte,prot,t1
1434
1435	iitlbt          pte,prot
1436
1437	tlb_unlock1	spc,t0
1438	rfir
1439	nop
1440
1441naitlb_miss_20w:
1442
1443	/*
1444	 * I miss is a little different, since we allow users to fault
1445	 * on the gateway page which is in the kernel address space.
1446	 */
1447
1448	space_adjust	spc,va,t0
1449	get_pgd		spc,ptp
1450	space_check	spc,t0,naitlb_fault
1451
1452	L3_ptep		ptp,pte,t0,va,naitlb_check_alias_20w
1453
1454	tlb_lock	spc,ptp,pte,t0,t1,naitlb_check_alias_20w
1455	update_accessed	ptp,pte,t0,t1
1456
1457	make_insert_tlb	spc,pte,prot,t1
1458
1459	iitlbt          pte,prot
1460
1461	tlb_unlock1	spc,t0
1462	rfir
1463	nop
1464
1465naitlb_check_alias_20w:
1466	do_alias	spc,t0,t1,va,pte,prot,naitlb_fault,20
1467
1468	iitlbt		pte,prot
1469
1470	rfir
1471	nop
1472
1473#else
1474
1475itlb_miss_11:
1476	get_pgd		spc,ptp
1477
1478	space_check	spc,t0,itlb_fault
1479
1480	L2_ptep		ptp,pte,t0,va,itlb_fault
1481
1482	tlb_lock	spc,ptp,pte,t0,t1,itlb_fault
1483	update_accessed	ptp,pte,t0,t1
1484
1485	make_insert_tlb_11	spc,pte,prot
1486
1487	mfsp		%sr1,t1  /* Save sr1 so we can use it in tlb inserts */
1488	mtsp		spc,%sr1
1489
1490	iitlba		pte,(%sr1,va)
1491	iitlbp		prot,(%sr1,va)
1492
1493	mtsp		t1, %sr1	/* Restore sr1 */
1494
1495	tlb_unlock1	spc,t0
1496	rfir
1497	nop
1498
1499naitlb_miss_11:
1500	get_pgd		spc,ptp
1501
1502	space_check	spc,t0,naitlb_fault
1503
1504	L2_ptep		ptp,pte,t0,va,naitlb_check_alias_11
1505
1506	tlb_lock	spc,ptp,pte,t0,t1,naitlb_check_alias_11
1507	update_accessed	ptp,pte,t0,t1
1508
1509	make_insert_tlb_11	spc,pte,prot
1510
1511	mfsp		%sr1,t1  /* Save sr1 so we can use it in tlb inserts */
1512	mtsp		spc,%sr1
1513
1514	iitlba		pte,(%sr1,va)
1515	iitlbp		prot,(%sr1,va)
1516
1517	mtsp		t1, %sr1	/* Restore sr1 */
1518
1519	tlb_unlock1	spc,t0
1520	rfir
1521	nop
1522
1523naitlb_check_alias_11:
1524	do_alias	spc,t0,t1,va,pte,prot,itlb_fault,11
1525
1526	iitlba          pte,(%sr0, va)
1527	iitlbp          prot,(%sr0, va)
1528
1529	rfir
1530	nop
1531
1532
1533itlb_miss_20:
1534	get_pgd		spc,ptp
1535
1536	space_check	spc,t0,itlb_fault
1537
1538	L2_ptep		ptp,pte,t0,va,itlb_fault
1539
1540	tlb_lock	spc,ptp,pte,t0,t1,itlb_fault
1541	update_accessed	ptp,pte,t0,t1
1542
1543	make_insert_tlb	spc,pte,prot,t1
1544
1545	f_extend	pte,t1
1546
1547	iitlbt          pte,prot
1548
1549	tlb_unlock1	spc,t0
1550	rfir
1551	nop
1552
1553naitlb_miss_20:
1554	get_pgd		spc,ptp
1555
1556	space_check	spc,t0,naitlb_fault
1557
1558	L2_ptep		ptp,pte,t0,va,naitlb_check_alias_20
1559
1560	tlb_lock	spc,ptp,pte,t0,t1,naitlb_check_alias_20
1561	update_accessed	ptp,pte,t0,t1
1562
1563	make_insert_tlb	spc,pte,prot,t1
1564
1565	f_extend	pte,t1
1566
1567	iitlbt          pte,prot
1568
1569	tlb_unlock1	spc,t0
1570	rfir
1571	nop
1572
1573naitlb_check_alias_20:
1574	do_alias	spc,t0,t1,va,pte,prot,naitlb_fault,20
1575
1576	iitlbt          pte,prot
1577
1578	rfir
1579	nop
1580
1581#endif
1582
1583#ifdef CONFIG_64BIT
1584
1585dbit_trap_20w:
1586	space_adjust	spc,va,t0
1587	get_pgd		spc,ptp
1588	space_check	spc,t0,dbit_fault
1589
1590	L3_ptep		ptp,pte,t0,va,dbit_fault
1591
1592	tlb_lock	spc,ptp,pte,t0,t1,dbit_fault
1593	update_dirty	ptp,pte,t1
1594
1595	make_insert_tlb	spc,pte,prot,t1
1596
1597	idtlbt          pte,prot
1598
1599	tlb_unlock0	spc,t0
1600	rfir
1601	nop
1602#else
1603
1604dbit_trap_11:
1605
1606	get_pgd		spc,ptp
1607
1608	space_check	spc,t0,dbit_fault
1609
1610	L2_ptep		ptp,pte,t0,va,dbit_fault
1611
1612	tlb_lock	spc,ptp,pte,t0,t1,dbit_fault
1613	update_dirty	ptp,pte,t1
1614
1615	make_insert_tlb_11	spc,pte,prot
1616
1617	mfsp            %sr1,t1  /* Save sr1 so we can use it in tlb inserts */
1618	mtsp		spc,%sr1
1619
1620	idtlba		pte,(%sr1,va)
1621	idtlbp		prot,(%sr1,va)
1622
1623	mtsp            t1, %sr1     /* Restore sr1 */
1624
1625	tlb_unlock0	spc,t0
1626	rfir
1627	nop
1628
1629dbit_trap_20:
1630	get_pgd		spc,ptp
1631
1632	space_check	spc,t0,dbit_fault
1633
1634	L2_ptep		ptp,pte,t0,va,dbit_fault
1635
1636	tlb_lock	spc,ptp,pte,t0,t1,dbit_fault
1637	update_dirty	ptp,pte,t1
1638
1639	make_insert_tlb	spc,pte,prot,t1
1640
1641	f_extend	pte,t1
1642
1643	idtlbt		pte,prot
1644
1645	tlb_unlock0	spc,t0
1646	rfir
1647	nop
1648#endif
1649
1650	.import handle_interruption,code
1651
1652kernel_bad_space:
1653	b               intr_save
1654	ldi             31,%r8  /* Use an unused code */
1655
1656dbit_fault:
1657	b               intr_save
1658	ldi             20,%r8
1659
1660itlb_fault:
1661	b               intr_save
1662	ldi             PARISC_ITLB_TRAP,%r8
1663
1664nadtlb_fault:
1665	b               intr_save
1666	ldi             17,%r8
1667
1668naitlb_fault:
1669	b               intr_save
1670	ldi             16,%r8
1671
1672dtlb_fault:
1673	b               intr_save
1674	ldi             15,%r8
1675
1676	/* Register saving semantics for system calls:
1677
1678	   %r1		   clobbered by system call macro in userspace
1679	   %r2		   saved in PT_REGS by gateway page
1680	   %r3  - %r18	   preserved by C code (saved by signal code)
1681	   %r19 - %r20	   saved in PT_REGS by gateway page
1682	   %r21 - %r22	   non-standard syscall args
1683			   stored in kernel stack by gateway page
1684	   %r23 - %r26	   arg3-arg0, saved in PT_REGS by gateway page
1685	   %r27 - %r30	   saved in PT_REGS by gateway page
1686	   %r31		   syscall return pointer
1687	 */
1688
1689	/* Floating point registers (FIXME: what do we do with these?)
1690
1691	   %fr0  - %fr3	   status/exception, not preserved
1692	   %fr4  - %fr7	   arguments
1693	   %fr8	 - %fr11   not preserved by C code
1694	   %fr12 - %fr21   preserved by C code
1695	   %fr22 - %fr31   not preserved by C code
1696	 */
1697
1698	.macro	reg_save regs
1699	STREG	%r3, PT_GR3(\regs)
1700	STREG	%r4, PT_GR4(\regs)
1701	STREG	%r5, PT_GR5(\regs)
1702	STREG	%r6, PT_GR6(\regs)
1703	STREG	%r7, PT_GR7(\regs)
1704	STREG	%r8, PT_GR8(\regs)
1705	STREG	%r9, PT_GR9(\regs)
1706	STREG   %r10,PT_GR10(\regs)
1707	STREG   %r11,PT_GR11(\regs)
1708	STREG   %r12,PT_GR12(\regs)
1709	STREG   %r13,PT_GR13(\regs)
1710	STREG   %r14,PT_GR14(\regs)
1711	STREG   %r15,PT_GR15(\regs)
1712	STREG   %r16,PT_GR16(\regs)
1713	STREG   %r17,PT_GR17(\regs)
1714	STREG   %r18,PT_GR18(\regs)
1715	.endm
1716
1717	.macro	reg_restore regs
1718	LDREG	PT_GR3(\regs), %r3
1719	LDREG	PT_GR4(\regs), %r4
1720	LDREG	PT_GR5(\regs), %r5
1721	LDREG	PT_GR6(\regs), %r6
1722	LDREG	PT_GR7(\regs), %r7
1723	LDREG	PT_GR8(\regs), %r8
1724	LDREG	PT_GR9(\regs), %r9
1725	LDREG   PT_GR10(\regs),%r10
1726	LDREG   PT_GR11(\regs),%r11
1727	LDREG   PT_GR12(\regs),%r12
1728	LDREG   PT_GR13(\regs),%r13
1729	LDREG   PT_GR14(\regs),%r14
1730	LDREG   PT_GR15(\regs),%r15
1731	LDREG   PT_GR16(\regs),%r16
1732	LDREG   PT_GR17(\regs),%r17
1733	LDREG   PT_GR18(\regs),%r18
1734	.endm
1735
1736	.macro	fork_like name
1737ENTRY_CFI(sys_\name\()_wrapper)
1738	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
1739	ldo	TASK_REGS(%r1),%r1
1740	reg_save %r1
1741	mfctl	%cr27, %r28
1742	ldil	L%sys_\name, %r31
1743	be	R%sys_\name(%sr4,%r31)
1744	STREG	%r28, PT_CR27(%r1)
1745ENDPROC_CFI(sys_\name\()_wrapper)
1746	.endm
1747
1748fork_like clone
1749fork_like fork
1750fork_like vfork
1751
1752	/* Set the return value for the child */
1753ENTRY(child_return)
1754	BL	schedule_tail, %r2
1755	nop
1756finish_child_return:
1757	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
1758	ldo	TASK_REGS(%r1),%r1	 /* get pt regs */
1759
1760	LDREG	PT_CR27(%r1), %r3
1761	mtctl	%r3, %cr27
1762	reg_restore %r1
1763	b	syscall_exit
1764	copy	%r0,%r28
1765END(child_return)
1766
1767ENTRY_CFI(sys_rt_sigreturn_wrapper)
1768	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r26
1769	ldo	TASK_REGS(%r26),%r26	/* get pt regs */
1770	/* Don't save regs, we are going to restore them from sigcontext. */
1771	STREG	%r2, -RP_OFFSET(%r30)
1772#ifdef CONFIG_64BIT
1773	ldo	FRAME_SIZE(%r30), %r30
1774	BL	sys_rt_sigreturn,%r2
1775	ldo	-16(%r30),%r29		/* Reference param save area */
1776#else
1777	BL	sys_rt_sigreturn,%r2
1778	ldo	FRAME_SIZE(%r30), %r30
1779#endif
1780
1781	ldo	-FRAME_SIZE(%r30), %r30
1782	LDREG	-RP_OFFSET(%r30), %r2
1783
1784	/* FIXME: I think we need to restore a few more things here. */
1785	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1786	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
1787	reg_restore %r1
1788
1789	/* If the signal was received while the process was blocked on a
1790	 * syscall, then r2 will take us to syscall_exit; otherwise r2 will
1791	 * take us to syscall_exit_rfi and on to intr_return.
1792	 */
1793	bv	%r0(%r2)
1794	LDREG	PT_GR28(%r1),%r28  /* reload original r28 for syscall_exit */
1795ENDPROC_CFI(sys_rt_sigreturn_wrapper)
1796
1797ENTRY(syscall_exit)
1798	/* NOTE: Not all syscalls exit this way.  rt_sigreturn will exit
1799	 * via syscall_exit_rfi if the signal was received while the process
1800	 * was running.
1801	 */
1802
1803	/* save return value now */
1804
1805	mfctl     %cr30, %r1
1806	LDREG     TI_TASK(%r1),%r1
1807	STREG     %r28,TASK_PT_GR28(%r1)
1808
1809	/* Seems to me that dp could be wrong here, if the syscall involved
1810	 * calling a module, and nothing got round to restoring dp on return.
1811	 */
1812	loadgp
1813
1814syscall_check_resched:
1815
1816	/* check for reschedule */
1817
1818	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19	/* long */
1819	bb,<,n	%r19, 31-TIF_NEED_RESCHED, syscall_do_resched /* forward */
1820
1821	.import do_signal,code
1822syscall_check_sig:
1823	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
1824	ldi	(_TIF_SIGPENDING|_TIF_NOTIFY_RESUME), %r26
1825	and,COND(<>)	%r19, %r26, %r0
1826	b,n	syscall_restore	/* skip past if we've nothing to do */
1827
1828syscall_do_signal:
1829	/* Save callee-save registers (for sigcontext).
1830	 * FIXME: After this point the process structure should be
1831	 * consistent with all the relevant state of the process
1832	 * before the syscall.  We need to verify this.
1833	 */
1834	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1835	ldo	TASK_REGS(%r1), %r26		/* struct pt_regs *regs */
1836	reg_save %r26
1837
1838#ifdef CONFIG_64BIT
1839	ldo	-16(%r30),%r29			/* Reference param save area */
1840#endif
1841
1842	BL	do_notify_resume,%r2
1843	ldi	1, %r25				/* long in_syscall = 1 */
1844
1845	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1846	ldo	TASK_REGS(%r1), %r20		/* reload pt_regs */
1847	reg_restore %r20
1848
1849	b,n     syscall_check_sig
1850
1851syscall_restore:
1852	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1853
1854	/* Are we being ptraced? */
1855	ldw	TASK_FLAGS(%r1),%r19
1856	ldi	_TIF_SYSCALL_TRACE_MASK,%r2
1857	and,COND(=)	%r19,%r2,%r0
1858	b,n	syscall_restore_rfi
1859
1860	ldo	TASK_PT_FR31(%r1),%r19		   /* reload fpregs */
1861	rest_fp	%r19
1862
1863	LDREG	TASK_PT_SAR(%r1),%r19		   /* restore SAR */
1864	mtsar	%r19
1865
1866	LDREG	TASK_PT_GR2(%r1),%r2		   /* restore user rp */
1867	LDREG	TASK_PT_GR19(%r1),%r19
1868	LDREG   TASK_PT_GR20(%r1),%r20
1869	LDREG	TASK_PT_GR21(%r1),%r21
1870	LDREG	TASK_PT_GR22(%r1),%r22
1871	LDREG	TASK_PT_GR23(%r1),%r23
1872	LDREG	TASK_PT_GR24(%r1),%r24
1873	LDREG	TASK_PT_GR25(%r1),%r25
1874	LDREG	TASK_PT_GR26(%r1),%r26
1875	LDREG	TASK_PT_GR27(%r1),%r27	   /* restore user dp */
1876	LDREG	TASK_PT_GR28(%r1),%r28	   /* syscall return value */
1877	LDREG	TASK_PT_GR29(%r1),%r29
1878	LDREG	TASK_PT_GR31(%r1),%r31	   /* restore syscall rp */
1879
1880	/* NOTE: We use rsm/ssm pair to make this operation atomic */
1881	LDREG   TASK_PT_GR30(%r1),%r1              /* Get user sp */
1882	rsm     PSW_SM_I, %r0
1883	copy    %r1,%r30                           /* Restore user sp */
1884	mfsp    %sr3,%r1                           /* Get user space id */
1885	mtsp    %r1,%sr7                           /* Restore sr7 */
1886	ssm     PSW_SM_I, %r0
1887
1888	/* Set sr2 to zero for userspace syscalls to work. */
1889	mtsp	%r0,%sr2
1890	mtsp	%r1,%sr4			   /* Restore sr4 */
1891	mtsp	%r1,%sr5			   /* Restore sr5 */
1892	mtsp	%r1,%sr6			   /* Restore sr6 */
1893
1894	depi	3,31,2,%r31			   /* ensure return to user mode. */
1895
1896#ifdef CONFIG_64BIT
1897	/* decide whether to reset the wide mode bit
1898	 *
1899	 * For a syscall, the W bit is stored in the lowest bit
1900	 * of sp.  Extract it and reset W if it is zero */
1901	extrd,u,*<>	%r30,63,1,%r1
1902	rsm	PSW_SM_W, %r0
1903	/* now reset the lowest bit of sp if it was set */
1904	xor	%r30,%r1,%r30
1905#endif
1906	be,n    0(%sr3,%r31)                       /* return to user space */
1907
1908	/* We have to return via an RFI, so that PSW T and R bits can be set
1909	 * appropriately.
1910	 * This sets up pt_regs so we can return via intr_restore, which is not
1911	 * the most efficient way of doing things, but it works.
1912	 */
1913syscall_restore_rfi:
1914	ldo	-1(%r0),%r2			   /* Set recovery cntr to -1 */
1915	mtctl	%r2,%cr0			   /*   for immediate trap */
1916	LDREG	TASK_PT_PSW(%r1),%r2		   /* Get old PSW */
1917	ldi	0x0b,%r20			   /* Create new PSW */
1918	depi	-1,13,1,%r20			   /* C, Q, D, and I bits */
1919
1920	/* The values of SINGLESTEP_BIT and BLOCKSTEP_BIT are
1921	 * set in thread_info.h and converted to PA bitmap
1922	 * numbers in asm-offsets.c */
1923
1924	/* if ((%r19.SINGLESTEP_BIT)) { %r20.27=1} */
1925	extru,=	%r19,TIF_SINGLESTEP_PA_BIT,1,%r0
1926	depi	-1,27,1,%r20			   /* R bit */
1927
1928	/* if ((%r19.BLOCKSTEP_BIT)) { %r20.7=1} */
1929	extru,= %r19,TIF_BLOCKSTEP_PA_BIT,1,%r0
1930	depi	-1,7,1,%r20			   /* T bit */
1931
1932	STREG	%r20,TASK_PT_PSW(%r1)
1933
1934	/* Always store space registers, since sr3 can be changed (e.g. fork) */
1935
1936	mfsp    %sr3,%r25
1937	STREG   %r25,TASK_PT_SR3(%r1)
1938	STREG   %r25,TASK_PT_SR4(%r1)
1939	STREG   %r25,TASK_PT_SR5(%r1)
1940	STREG   %r25,TASK_PT_SR6(%r1)
1941	STREG   %r25,TASK_PT_SR7(%r1)
1942	STREG   %r25,TASK_PT_IASQ0(%r1)
1943	STREG   %r25,TASK_PT_IASQ1(%r1)
1944
1945	/* XXX W bit??? */
1946	/* Now if old D bit is clear, it means we didn't save all registers
1947	 * on syscall entry, so do that now.  This only happens on TRACEME
1948	 * calls, or if someone attached to us while we were on a syscall.
1949	 * We could make this more efficient by not saving r3-r18, but
1950	 * then we wouldn't be able to use the common intr_restore path.
1951	 * It is only for traced processes anyway, so performance is not
1952	 * an issue.
1953	 */
1954	bb,<	%r2,30,pt_regs_ok		   /* Branch if D set */
1955	ldo	TASK_REGS(%r1),%r25
1956	reg_save %r25				   /* Save r3 to r18 */
1957
1958	/* Save the current sr */
1959	mfsp	%sr0,%r2
1960	STREG	%r2,TASK_PT_SR0(%r1)
1961
1962	/* Save the scratch sr */
1963	mfsp	%sr1,%r2
1964	STREG	%r2,TASK_PT_SR1(%r1)
1965
1966	/* sr2 should be set to zero for userspace syscalls */
1967	STREG	%r0,TASK_PT_SR2(%r1)
1968
1969	LDREG	TASK_PT_GR31(%r1),%r2
1970	depi	3,31,2,%r2		   /* ensure return to user mode. */
1971	STREG   %r2,TASK_PT_IAOQ0(%r1)
1972	ldo	4(%r2),%r2
1973	STREG	%r2,TASK_PT_IAOQ1(%r1)
1974	b	intr_restore
1975	copy	%r25,%r16
1976
1977pt_regs_ok:
1978	LDREG	TASK_PT_IAOQ0(%r1),%r2
1979	depi	3,31,2,%r2		   /* ensure return to user mode. */
1980	STREG	%r2,TASK_PT_IAOQ0(%r1)
1981	LDREG	TASK_PT_IAOQ1(%r1),%r2
1982	depi	3,31,2,%r2
1983	STREG	%r2,TASK_PT_IAOQ1(%r1)
1984	b	intr_restore
1985	copy	%r25,%r16
1986
1987syscall_do_resched:
1988	load32	syscall_check_resched,%r2 /* if resched, we start over again */
1989	load32	schedule,%r19
1990	bv	%r0(%r19)		/* jumps to schedule() */
1991#ifdef CONFIG_64BIT
1992	ldo	-16(%r30),%r29		/* Reference param save area */
1993#else
1994	nop
1995#endif
1996END(syscall_exit)
1997
1998
1999#ifdef CONFIG_FUNCTION_TRACER
2000
2001	.import ftrace_function_trampoline,code
2002	.align L1_CACHE_BYTES
2003ENTRY_CFI(mcount, caller)
2004_mcount:
2005	.export _mcount,data
2006	/*
2007	 * The 64bit mcount() function pointer needs 4 dwords, of which the
2008	 * first two are free.  We optimize it here and put 2 instructions for
2009	 * calling mcount(), and 2 instructions for ftrace_stub().  That way we
2010	 * have all on one L1 cacheline.
2011	 */
2012	b	ftrace_function_trampoline
2013	copy	%r3, %arg2	/* caller original %sp */
2014ftrace_stub:
2015	.globl ftrace_stub
2016        .type  ftrace_stub, @function
2017#ifdef CONFIG_64BIT
2018	bve	(%rp)
2019#else
2020	bv	%r0(%rp)
2021#endif
2022	nop
2023#ifdef CONFIG_64BIT
2024	.dword mcount
2025	.dword 0 /* code in head.S puts value of global gp here */
2026#endif
2027ENDPROC_CFI(mcount)
2028
2029#ifdef CONFIG_FUNCTION_GRAPH_TRACER
2030	.align 8
2031ENTRY_CFI(return_to_handler, caller,frame=FRAME_SIZE)
2032	.export parisc_return_to_handler,data
2033parisc_return_to_handler:
2034	copy %r3,%r1
2035	STREG %r0,-RP_OFFSET(%sp)	/* store 0 as %rp */
2036	copy %sp,%r3
2037	STREGM %r1,FRAME_SIZE(%sp)
2038	STREG %ret0,8(%r3)
2039	STREG %ret1,16(%r3)
2040
2041#ifdef CONFIG_64BIT
2042	loadgp
2043#endif
2044
2045	/* call ftrace_return_to_handler(0) */
2046	.import ftrace_return_to_handler,code
2047	load32 ftrace_return_to_handler,%ret0
2048	load32 .Lftrace_ret,%r2
2049#ifdef CONFIG_64BIT
2050	ldo -16(%sp),%ret1		/* Reference param save area */
2051	bve	(%ret0)
2052#else
2053	bv	%r0(%ret0)
2054#endif
2055	ldi 0,%r26
2056.Lftrace_ret:
2057	copy %ret0,%rp
2058
2059	/* restore original return values */
2060	LDREG 8(%r3),%ret0
2061	LDREG 16(%r3),%ret1
2062
2063	/* return from function */
2064#ifdef CONFIG_64BIT
2065	bve	(%rp)
2066#else
2067	bv	%r0(%rp)
2068#endif
2069	LDREGM -FRAME_SIZE(%sp),%r3
2070ENDPROC_CFI(return_to_handler)
2071
2072#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
2073
2074#endif	/* CONFIG_FUNCTION_TRACER */
2075
2076#ifdef CONFIG_IRQSTACKS
2077/* void call_on_stack(unsigned long param1, void *func,
2078		      unsigned long new_stack) */
2079ENTRY_CFI(call_on_stack, FRAME=2*FRAME_SIZE,CALLS,SAVE_RP,SAVE_SP)
2080ENTRY(_call_on_stack)
2081	copy	%sp, %r1
2082
2083	/* Regarding the HPPA calling conventions for function pointers,
2084	   we assume the PIC register is not changed across call.  For
2085	   CONFIG_64BIT, the argument pointer is left to point at the
2086	   argument region allocated for the call to call_on_stack. */
2087
2088	/* Switch to new stack.  We allocate two frames.  */
2089	ldo	2*FRAME_SIZE(%arg2), %sp
2090# ifdef CONFIG_64BIT
2091	/* Save previous stack pointer and return pointer in frame marker */
2092	STREG	%rp, -FRAME_SIZE-RP_OFFSET(%sp)
2093	/* Calls always use function descriptor */
2094	LDREG	16(%arg1), %arg1
2095	bve,l	(%arg1), %rp
2096	STREG	%r1, -FRAME_SIZE-REG_SZ(%sp)
2097	LDREG	-FRAME_SIZE-RP_OFFSET(%sp), %rp
2098	bve	(%rp)
2099	LDREG	-FRAME_SIZE-REG_SZ(%sp), %sp
2100# else
2101	/* Save previous stack pointer and return pointer in frame marker */
2102	STREG	%r1, -FRAME_SIZE-REG_SZ(%sp)
2103	STREG	%rp, -FRAME_SIZE-RP_OFFSET(%sp)
2104	/* Calls use function descriptor if PLABEL bit is set */
2105	bb,>=,n	%arg1, 30, 1f
2106	depwi	0,31,2, %arg1
2107	LDREG	0(%arg1), %arg1
21081:
2109	be,l	0(%sr4,%arg1), %sr0, %r31
2110	copy	%r31, %rp
2111	LDREG	-FRAME_SIZE-RP_OFFSET(%sp), %rp
2112	bv	(%rp)
2113	LDREG	-FRAME_SIZE-REG_SZ(%sp), %sp
2114# endif /* CONFIG_64BIT */
2115ENDPROC_CFI(call_on_stack)
2116#endif /* CONFIG_IRQSTACKS */
2117
2118ENTRY_CFI(get_register)
2119	/*
2120	 * get_register is used by the non access tlb miss handlers to
2121	 * copy the value of the general register specified in r8 into
2122	 * r1. This routine can't be used for shadowed registers, since
2123	 * the rfir will restore the original value. So, for the shadowed
2124	 * registers we put a -1 into r1 to indicate that the register
2125	 * should not be used (the register being copied could also have
2126	 * a -1 in it, but that is OK, it just means that we will have
2127	 * to use the slow path instead).
2128	 */
2129	blr     %r8,%r0
2130	nop
2131	bv      %r0(%r25)    /* r0 */
2132	copy    %r0,%r1
2133	bv      %r0(%r25)    /* r1 - shadowed */
2134	ldi     -1,%r1
2135	bv      %r0(%r25)    /* r2 */
2136	copy    %r2,%r1
2137	bv      %r0(%r25)    /* r3 */
2138	copy    %r3,%r1
2139	bv      %r0(%r25)    /* r4 */
2140	copy    %r4,%r1
2141	bv      %r0(%r25)    /* r5 */
2142	copy    %r5,%r1
2143	bv      %r0(%r25)    /* r6 */
2144	copy    %r6,%r1
2145	bv      %r0(%r25)    /* r7 */
2146	copy    %r7,%r1
2147	bv      %r0(%r25)    /* r8 - shadowed */
2148	ldi     -1,%r1
2149	bv      %r0(%r25)    /* r9 - shadowed */
2150	ldi     -1,%r1
2151	bv      %r0(%r25)    /* r10 */
2152	copy    %r10,%r1
2153	bv      %r0(%r25)    /* r11 */
2154	copy    %r11,%r1
2155	bv      %r0(%r25)    /* r12 */
2156	copy    %r12,%r1
2157	bv      %r0(%r25)    /* r13 */
2158	copy    %r13,%r1
2159	bv      %r0(%r25)    /* r14 */
2160	copy    %r14,%r1
2161	bv      %r0(%r25)    /* r15 */
2162	copy    %r15,%r1
2163	bv      %r0(%r25)    /* r16 - shadowed */
2164	ldi     -1,%r1
2165	bv      %r0(%r25)    /* r17 - shadowed */
2166	ldi     -1,%r1
2167	bv      %r0(%r25)    /* r18 */
2168	copy    %r18,%r1
2169	bv      %r0(%r25)    /* r19 */
2170	copy    %r19,%r1
2171	bv      %r0(%r25)    /* r20 */
2172	copy    %r20,%r1
2173	bv      %r0(%r25)    /* r21 */
2174	copy    %r21,%r1
2175	bv      %r0(%r25)    /* r22 */
2176	copy    %r22,%r1
2177	bv      %r0(%r25)    /* r23 */
2178	copy    %r23,%r1
2179	bv      %r0(%r25)    /* r24 - shadowed */
2180	ldi     -1,%r1
2181	bv      %r0(%r25)    /* r25 - shadowed */
2182	ldi     -1,%r1
2183	bv      %r0(%r25)    /* r26 */
2184	copy    %r26,%r1
2185	bv      %r0(%r25)    /* r27 */
2186	copy    %r27,%r1
2187	bv      %r0(%r25)    /* r28 */
2188	copy    %r28,%r1
2189	bv      %r0(%r25)    /* r29 */
2190	copy    %r29,%r1
2191	bv      %r0(%r25)    /* r30 */
2192	copy    %r30,%r1
2193	bv      %r0(%r25)    /* r31 */
2194	copy    %r31,%r1
2195ENDPROC_CFI(get_register)
2196
2197
2198ENTRY_CFI(set_register)
2199	/*
2200	 * set_register is used by the non access tlb miss handlers to
2201	 * copy the value of r1 into the general register specified in
2202	 * r8.
2203	 */
2204	blr     %r8,%r0
2205	nop
2206	bv      %r0(%r25)    /* r0 (silly, but it is a place holder) */
2207	copy    %r1,%r0
2208	bv      %r0(%r25)    /* r1 */
2209	copy    %r1,%r1
2210	bv      %r0(%r25)    /* r2 */
2211	copy    %r1,%r2
2212	bv      %r0(%r25)    /* r3 */
2213	copy    %r1,%r3
2214	bv      %r0(%r25)    /* r4 */
2215	copy    %r1,%r4
2216	bv      %r0(%r25)    /* r5 */
2217	copy    %r1,%r5
2218	bv      %r0(%r25)    /* r6 */
2219	copy    %r1,%r6
2220	bv      %r0(%r25)    /* r7 */
2221	copy    %r1,%r7
2222	bv      %r0(%r25)    /* r8 */
2223	copy    %r1,%r8
2224	bv      %r0(%r25)    /* r9 */
2225	copy    %r1,%r9
2226	bv      %r0(%r25)    /* r10 */
2227	copy    %r1,%r10
2228	bv      %r0(%r25)    /* r11 */
2229	copy    %r1,%r11
2230	bv      %r0(%r25)    /* r12 */
2231	copy    %r1,%r12
2232	bv      %r0(%r25)    /* r13 */
2233	copy    %r1,%r13
2234	bv      %r0(%r25)    /* r14 */
2235	copy    %r1,%r14
2236	bv      %r0(%r25)    /* r15 */
2237	copy    %r1,%r15
2238	bv      %r0(%r25)    /* r16 */
2239	copy    %r1,%r16
2240	bv      %r0(%r25)    /* r17 */
2241	copy    %r1,%r17
2242	bv      %r0(%r25)    /* r18 */
2243	copy    %r1,%r18
2244	bv      %r0(%r25)    /* r19 */
2245	copy    %r1,%r19
2246	bv      %r0(%r25)    /* r20 */
2247	copy    %r1,%r20
2248	bv      %r0(%r25)    /* r21 */
2249	copy    %r1,%r21
2250	bv      %r0(%r25)    /* r22 */
2251	copy    %r1,%r22
2252	bv      %r0(%r25)    /* r23 */
2253	copy    %r1,%r23
2254	bv      %r0(%r25)    /* r24 */
2255	copy    %r1,%r24
2256	bv      %r0(%r25)    /* r25 */
2257	copy    %r1,%r25
2258	bv      %r0(%r25)    /* r26 */
2259	copy    %r1,%r26
2260	bv      %r0(%r25)    /* r27 */
2261	copy    %r1,%r27
2262	bv      %r0(%r25)    /* r28 */
2263	copy    %r1,%r28
2264	bv      %r0(%r25)    /* r29 */
2265	copy    %r1,%r29
2266	bv      %r0(%r25)    /* r30 */
2267	copy    %r1,%r30
2268	bv      %r0(%r25)    /* r31 */
2269	copy    %r1,%r31
2270ENDPROC_CFI(set_register)
2271
2272