xref: /openbmc/linux/arch/parisc/kernel/entry.S (revision 64c70b1c)
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#define CMPIB           cmpib,*
44#define CMPB            cmpb,*
45#define COND(x)		*x
46
47	.level 2.0w
48#else
49#define CMPIB           cmpib,
50#define CMPB            cmpb,
51#define COND(x)		x
52
53	.level 2.0
54#endif
55
56	.import         pa_dbit_lock,data
57
58	/* space_to_prot macro creates a prot id from a space id */
59
60#if (SPACEID_SHIFT) == 0
61	.macro  space_to_prot spc prot
62	depd,z  \spc,62,31,\prot
63	.endm
64#else
65	.macro  space_to_prot spc prot
66	extrd,u \spc,(64 - (SPACEID_SHIFT)),32,\prot
67	.endm
68#endif
69
70	/* Switch to virtual mapping, trashing only %r1 */
71	.macro  virt_map
72	/* pcxt_ssm_bug */
73	rsm	PSW_SM_I, %r0	/* barrier for "Relied upon Translation */
74	mtsp	%r0, %sr4
75	mtsp	%r0, %sr5
76	mfsp	%sr7, %r1
77	or,=    %r0,%r1,%r0	/* Only save sr7 in sr3 if sr7 != 0 */
78	mtsp	%r1, %sr3
79	tovirt_r1 %r29
80	load32	KERNEL_PSW, %r1
81
82	rsm     PSW_SM_QUIET,%r0	/* second "heavy weight" ctl op */
83	mtsp	%r0, %sr6
84	mtsp	%r0, %sr7
85	mtctl	%r0, %cr17	/* Clear IIASQ tail */
86	mtctl	%r0, %cr17	/* Clear IIASQ head */
87	mtctl	%r1, %ipsw
88	load32	4f, %r1
89	mtctl	%r1, %cr18	/* Set IIAOQ tail */
90	ldo	4(%r1), %r1
91	mtctl	%r1, %cr18	/* Set IIAOQ head */
92	rfir
93	nop
944:
95	.endm
96
97	/*
98	 * The "get_stack" macros are responsible for determining the
99	 * kernel stack value.
100	 *
101	 * For Faults:
102	 *      If sr7 == 0
103	 *          Already using a kernel stack, so call the
104	 *          get_stack_use_r30 macro to push a pt_regs structure
105	 *          on the stack, and store registers there.
106	 *      else
107	 *          Need to set up a kernel stack, so call the
108	 *          get_stack_use_cr30 macro to set up a pointer
109	 *          to the pt_regs structure contained within the
110	 *          task pointer pointed to by cr30. Set the stack
111	 *          pointer to point to the end of the task structure.
112	 *
113	 * For Interrupts:
114	 *      If sr7 == 0
115	 *          Already using a kernel stack, check to see if r30
116	 *          is already pointing to the per processor interrupt
117	 *          stack. If it is, call the get_stack_use_r30 macro
118	 *          to push a pt_regs structure on the stack, and store
119	 *          registers there. Otherwise, call get_stack_use_cr31
120	 *          to get a pointer to the base of the interrupt stack
121	 *          and push a pt_regs structure on that stack.
122	 *      else
123	 *          Need to set up a kernel stack, so call the
124	 *          get_stack_use_cr30 macro to set up a pointer
125	 *          to the pt_regs structure contained within the
126	 *          task pointer pointed to by cr30. Set the stack
127	 *          pointer to point to the end of the task structure.
128	 *          N.B: We don't use the interrupt stack for the
129	 *          first interrupt from userland, because signals/
130	 *          resched's are processed when returning to userland,
131	 *          and we can sleep in those cases.
132	 *
133	 * Note that we use shadowed registers for temps until
134	 * we can save %r26 and %r29. %r26 is used to preserve
135	 * %r8 (a shadowed register) which temporarily contained
136	 * either the fault type ("code") or the eirr. We need
137	 * to use a non-shadowed register to carry the value over
138	 * the rfir in virt_map. We use %r26 since this value winds
139	 * up being passed as the argument to either do_cpu_irq_mask
140	 * or handle_interruption. %r29 is used to hold a pointer
141	 * the register save area, and once again, it needs to
142	 * be a non-shadowed register so that it survives the rfir.
143	 *
144	 * N.B. TASK_SZ_ALGN and PT_SZ_ALGN include space for a stack frame.
145	 */
146
147	.macro  get_stack_use_cr30
148
149	/* we save the registers in the task struct */
150
151	mfctl   %cr30, %r1
152	tophys  %r1,%r9
153	LDREG	TI_TASK(%r9), %r1	/* thread_info -> task_struct */
154	tophys  %r1,%r9
155	ldo     TASK_REGS(%r9),%r9
156	STREG   %r30, PT_GR30(%r9)
157	STREG   %r29,PT_GR29(%r9)
158	STREG   %r26,PT_GR26(%r9)
159	copy    %r9,%r29
160	mfctl   %cr30, %r1
161	ldo	THREAD_SZ_ALGN(%r1), %r30
162	.endm
163
164	.macro  get_stack_use_r30
165
166	/* we put a struct pt_regs on the stack and save the registers there */
167
168	tophys  %r30,%r9
169	STREG   %r30,PT_GR30(%r9)
170	ldo	PT_SZ_ALGN(%r30),%r30
171	STREG   %r29,PT_GR29(%r9)
172	STREG   %r26,PT_GR26(%r9)
173	copy    %r9,%r29
174	.endm
175
176	.macro  rest_stack
177	LDREG   PT_GR1(%r29), %r1
178	LDREG   PT_GR30(%r29),%r30
179	LDREG   PT_GR29(%r29),%r29
180	.endm
181
182	/* default interruption handler
183	 * (calls traps.c:handle_interruption) */
184	.macro	def code
185	b	intr_save
186	ldi     \code, %r8
187	.align	32
188	.endm
189
190	/* Interrupt interruption handler
191	 * (calls irq.c:do_cpu_irq_mask) */
192	.macro	extint code
193	b	intr_extint
194	mfsp    %sr7,%r16
195	.align	32
196	.endm
197
198	.import	os_hpmc, code
199
200	/* HPMC handler */
201	.macro	hpmc code
202	nop			/* must be a NOP, will be patched later */
203	load32	PA(os_hpmc), %r3
204	bv,n	0(%r3)
205	nop
206	.word	0		/* checksum (will be patched) */
207	.word	PA(os_hpmc)	/* address of handler */
208	.word	0		/* length of handler */
209	.endm
210
211	/*
212	 * Performance Note: Instructions will be moved up into
213	 * this part of the code later on, once we are sure
214	 * that the tlb miss handlers are close to final form.
215	 */
216
217	/* Register definitions for tlb miss handler macros */
218
219	va  = r8	/* virtual address for which the trap occured */
220	spc = r24	/* space for which the trap occured */
221
222#ifndef CONFIG_64BIT
223
224	/*
225	 * itlb miss interruption handler (parisc 1.1 - 32 bit)
226	 */
227
228	.macro	itlb_11 code
229
230	mfctl	%pcsq, spc
231	b	itlb_miss_11
232	mfctl	%pcoq, va
233
234	.align		32
235	.endm
236#endif
237
238	/*
239	 * itlb miss interruption handler (parisc 2.0)
240	 */
241
242	.macro	itlb_20 code
243	mfctl	%pcsq, spc
244#ifdef CONFIG_64BIT
245	b       itlb_miss_20w
246#else
247	b	itlb_miss_20
248#endif
249	mfctl	%pcoq, va
250
251	.align		32
252	.endm
253
254#ifndef CONFIG_64BIT
255	/*
256	 * naitlb miss interruption handler (parisc 1.1 - 32 bit)
257	 *
258	 * Note: naitlb misses will be treated
259	 * as an ordinary itlb miss for now.
260	 * However, note that naitlb misses
261	 * have the faulting address in the
262	 * IOR/ISR.
263	 */
264
265	.macro	naitlb_11 code
266
267	mfctl	%isr,spc
268	b	itlb_miss_11
269	mfctl 	%ior,va
270	/* FIXME: If user causes a naitlb miss, the priv level may not be in
271	 * lower bits of va, where the itlb miss handler is expecting them
272	 */
273
274	.align		32
275	.endm
276#endif
277
278	/*
279	 * naitlb miss interruption handler (parisc 2.0)
280	 *
281	 * Note: naitlb misses will be treated
282	 * as an ordinary itlb miss for now.
283	 * However, note that naitlb misses
284	 * have the faulting address in the
285	 * IOR/ISR.
286	 */
287
288	.macro	naitlb_20 code
289
290	mfctl	%isr,spc
291#ifdef CONFIG_64BIT
292	b       itlb_miss_20w
293#else
294	b	itlb_miss_20
295#endif
296	mfctl 	%ior,va
297	/* FIXME: If user causes a naitlb miss, the priv level may not be in
298	 * lower bits of va, where the itlb miss handler is expecting them
299	 */
300
301	.align		32
302	.endm
303
304#ifndef CONFIG_64BIT
305	/*
306	 * dtlb miss interruption handler (parisc 1.1 - 32 bit)
307	 */
308
309	.macro	dtlb_11 code
310
311	mfctl	%isr, spc
312	b	dtlb_miss_11
313	mfctl	%ior, va
314
315	.align		32
316	.endm
317#endif
318
319	/*
320	 * dtlb miss interruption handler (parisc 2.0)
321	 */
322
323	.macro	dtlb_20 code
324
325	mfctl	%isr, spc
326#ifdef CONFIG_64BIT
327	b       dtlb_miss_20w
328#else
329	b	dtlb_miss_20
330#endif
331	mfctl	%ior, va
332
333	.align		32
334	.endm
335
336#ifndef CONFIG_64BIT
337	/* nadtlb miss interruption handler (parisc 1.1 - 32 bit) */
338
339	.macro	nadtlb_11 code
340
341	mfctl	%isr,spc
342	b       nadtlb_miss_11
343	mfctl	%ior,va
344
345	.align		32
346	.endm
347#endif
348
349	/* nadtlb miss interruption handler (parisc 2.0) */
350
351	.macro	nadtlb_20 code
352
353	mfctl	%isr,spc
354#ifdef CONFIG_64BIT
355	b       nadtlb_miss_20w
356#else
357	b       nadtlb_miss_20
358#endif
359	mfctl	%ior,va
360
361	.align		32
362	.endm
363
364#ifndef CONFIG_64BIT
365	/*
366	 * dirty bit trap interruption handler (parisc 1.1 - 32 bit)
367	 */
368
369	.macro	dbit_11 code
370
371	mfctl	%isr,spc
372	b	dbit_trap_11
373	mfctl	%ior,va
374
375	.align		32
376	.endm
377#endif
378
379	/*
380	 * dirty bit trap interruption handler (parisc 2.0)
381	 */
382
383	.macro	dbit_20 code
384
385	mfctl	%isr,spc
386#ifdef CONFIG_64BIT
387	b       dbit_trap_20w
388#else
389	b	dbit_trap_20
390#endif
391	mfctl	%ior,va
392
393	.align		32
394	.endm
395
396	/* The following are simple 32 vs 64 bit instruction
397	 * abstractions for the macros */
398	.macro		EXTR	reg1,start,length,reg2
399#ifdef CONFIG_64BIT
400	extrd,u		\reg1,32+\start,\length,\reg2
401#else
402	extrw,u		\reg1,\start,\length,\reg2
403#endif
404	.endm
405
406	.macro		DEP	reg1,start,length,reg2
407#ifdef CONFIG_64BIT
408	depd		\reg1,32+\start,\length,\reg2
409#else
410	depw		\reg1,\start,\length,\reg2
411#endif
412	.endm
413
414	.macro		DEPI	val,start,length,reg
415#ifdef CONFIG_64BIT
416	depdi		\val,32+\start,\length,\reg
417#else
418	depwi		\val,\start,\length,\reg
419#endif
420	.endm
421
422	/* In LP64, the space contains part of the upper 32 bits of the
423	 * fault.  We have to extract this and place it in the va,
424	 * zeroing the corresponding bits in the space register */
425	.macro		space_adjust	spc,va,tmp
426#ifdef CONFIG_64BIT
427	extrd,u		\spc,63,SPACEID_SHIFT,\tmp
428	depd		%r0,63,SPACEID_SHIFT,\spc
429	depd		\tmp,31,SPACEID_SHIFT,\va
430#endif
431	.endm
432
433	.import		swapper_pg_dir,code
434
435	/* Get the pgd.  For faults on space zero (kernel space), this
436	 * is simply swapper_pg_dir.  For user space faults, the
437	 * pgd is stored in %cr25 */
438	.macro		get_pgd		spc,reg
439	ldil		L%PA(swapper_pg_dir),\reg
440	ldo		R%PA(swapper_pg_dir)(\reg),\reg
441	or,COND(=)	%r0,\spc,%r0
442	mfctl		%cr25,\reg
443	.endm
444
445	/*
446		space_check(spc,tmp,fault)
447
448		spc - The space we saw the fault with.
449		tmp - The place to store the current space.
450		fault - Function to call on failure.
451
452		Only allow faults on different spaces from the
453		currently active one if we're the kernel
454
455	*/
456	.macro		space_check	spc,tmp,fault
457	mfsp		%sr7,\tmp
458	or,COND(<>)	%r0,\spc,%r0	/* user may execute gateway page
459					 * as kernel, so defeat the space
460					 * check if it is */
461	copy		\spc,\tmp
462	or,COND(=)	%r0,\tmp,%r0	/* nullify if executing as kernel */
463	cmpb,COND(<>),n	\tmp,\spc,\fault
464	.endm
465
466	/* Look up a PTE in a 2-Level scheme (faulting at each
467	 * level if the entry isn't present
468	 *
469	 * NOTE: we use ldw even for LP64, since the short pointers
470	 * can address up to 1TB
471	 */
472	.macro		L2_ptep	pmd,pte,index,va,fault
473#if PT_NLEVELS == 3
474	EXTR		\va,31-ASM_PMD_SHIFT,ASM_BITS_PER_PMD,\index
475#else
476	EXTR		\va,31-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
477#endif
478	DEP             %r0,31,PAGE_SHIFT,\pmd  /* clear offset */
479	copy		%r0,\pte
480	ldw,s		\index(\pmd),\pmd
481	bb,>=,n		\pmd,_PxD_PRESENT_BIT,\fault
482	DEP		%r0,31,PxD_FLAG_SHIFT,\pmd /* clear flags */
483	copy		\pmd,%r9
484	SHLREG		%r9,PxD_VALUE_SHIFT,\pmd
485	EXTR		\va,31-PAGE_SHIFT,ASM_BITS_PER_PTE,\index
486	DEP		%r0,31,PAGE_SHIFT,\pmd  /* clear offset */
487	shladd		\index,BITS_PER_PTE_ENTRY,\pmd,\pmd
488	LDREG		%r0(\pmd),\pte		/* pmd is now pte */
489	bb,>=,n		\pte,_PAGE_PRESENT_BIT,\fault
490	.endm
491
492	/* Look up PTE in a 3-Level scheme.
493	 *
494	 * Here we implement a Hybrid L2/L3 scheme: we allocate the
495	 * first pmd adjacent to the pgd.  This means that we can
496	 * subtract a constant offset to get to it.  The pmd and pgd
497	 * sizes are arranged so that a single pmd covers 4GB (giving
498	 * a full LP64 process access to 8TB) so our lookups are
499	 * effectively L2 for the first 4GB of the kernel (i.e. for
500	 * all ILP32 processes and all the kernel for machines with
501	 * under 4GB of memory) */
502	.macro		L3_ptep pgd,pte,index,va,fault
503#if PT_NLEVELS == 3 /* we might have a 2-Level scheme, e.g. with 16kb page size */
504	extrd,u		\va,63-ASM_PGDIR_SHIFT,ASM_BITS_PER_PGD,\index
505	copy		%r0,\pte
506	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
507	ldw,s		\index(\pgd),\pgd
508	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
509	bb,>=,n		\pgd,_PxD_PRESENT_BIT,\fault
510	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
511	shld		\pgd,PxD_VALUE_SHIFT,\index
512	extrd,u,*=	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
513	copy		\index,\pgd
514	extrd,u,*<>	\va,63-ASM_PGDIR_SHIFT,64-ASM_PGDIR_SHIFT,%r0
515	ldo		ASM_PGD_PMD_OFFSET(\pgd),\pgd
516#endif
517	L2_ptep		\pgd,\pte,\index,\va,\fault
518	.endm
519
520	/* Set the _PAGE_ACCESSED bit of the PTE.  Be clever and
521	 * don't needlessly dirty the cache line if it was already set */
522	.macro		update_ptep	ptep,pte,tmp,tmp1
523	ldi		_PAGE_ACCESSED,\tmp1
524	or		\tmp1,\pte,\tmp
525	and,COND(<>)	\tmp1,\pte,%r0
526	STREG		\tmp,0(\ptep)
527	.endm
528
529	/* Set the dirty bit (and accessed bit).  No need to be
530	 * clever, this is only used from the dirty fault */
531	.macro		update_dirty	ptep,pte,tmp
532	ldi		_PAGE_ACCESSED|_PAGE_DIRTY,\tmp
533	or		\tmp,\pte,\pte
534	STREG		\pte,0(\ptep)
535	.endm
536
537	/* Convert the pte and prot to tlb insertion values.  How
538	 * this happens is quite subtle, read below */
539	.macro		make_insert_tlb	spc,pte,prot
540	space_to_prot   \spc \prot        /* create prot id from space */
541	/* The following is the real subtlety.  This is depositing
542	 * T <-> _PAGE_REFTRAP
543	 * D <-> _PAGE_DIRTY
544	 * B <-> _PAGE_DMB (memory break)
545	 *
546	 * Then incredible subtlety: The access rights are
547	 * _PAGE_GATEWAY _PAGE_EXEC _PAGE_READ
548	 * See 3-14 of the parisc 2.0 manual
549	 *
550	 * Finally, _PAGE_READ goes in the top bit of PL1 (so we
551	 * trigger an access rights trap in user space if the user
552	 * tries to read an unreadable page */
553	depd            \pte,8,7,\prot
554
555	/* PAGE_USER indicates the page can be read with user privileges,
556	 * so deposit X1|11 to PL1|PL2 (remember the upper bit of PL1
557	 * contains _PAGE_READ */
558	extrd,u,*=      \pte,_PAGE_USER_BIT+32,1,%r0
559	depdi		7,11,3,\prot
560	/* If we're a gateway page, drop PL2 back to zero for promotion
561	 * to kernel privilege (so we can execute the page as kernel).
562	 * Any privilege promotion page always denys read and write */
563	extrd,u,*= 	\pte,_PAGE_GATEWAY_BIT+32,1,%r0
564	depd		%r0,11,2,\prot	/* If Gateway, Set PL2 to 0 */
565
566	/* Enforce uncacheable pages.
567	 * This should ONLY be use for MMIO on PA 2.0 machines.
568	 * Memory/DMA is cache coherent on all PA2.0 machines we support
569	 * (that means T-class is NOT supported) and the memory controllers
570	 * on most of those machines only handles cache transactions.
571	 */
572	extrd,u,*=	\pte,_PAGE_NO_CACHE_BIT+32,1,%r0
573	depi		1,12,1,\prot
574
575	/* Drop prot bits and convert to page addr for iitlbt and idtlbt */
576	extrd,u		\pte,(63-ASM_PFN_PTE_SHIFT)+(63-58),64-PAGE_SHIFT,\pte
577	depdi		_PAGE_SIZE_ENCODING_DEFAULT,63,63-58,\pte
578	.endm
579
580	/* Identical macro to make_insert_tlb above, except it
581	 * makes the tlb entry for the differently formatted pa11
582	 * insertion instructions */
583	.macro		make_insert_tlb_11	spc,pte,prot
584	zdep		\spc,30,15,\prot
585	dep		\pte,8,7,\prot
586	extru,=		\pte,_PAGE_NO_CACHE_BIT,1,%r0
587	depi		1,12,1,\prot
588	extru,=         \pte,_PAGE_USER_BIT,1,%r0
589	depi		7,11,3,\prot   /* Set for user space (1 rsvd for read) */
590	extru,= 	\pte,_PAGE_GATEWAY_BIT,1,%r0
591	depi		0,11,2,\prot	/* If Gateway, Set PL2 to 0 */
592
593	/* Get rid of prot bits and convert to page addr for iitlba */
594
595	depi		_PAGE_SIZE_ENCODING_DEFAULT,31,ASM_PFN_PTE_SHIFT,\pte
596	extru		\pte,24,25,\pte
597	.endm
598
599	/* This is for ILP32 PA2.0 only.  The TLB insertion needs
600	 * to extend into I/O space if the address is 0xfXXXXXXX
601	 * so we extend the f's into the top word of the pte in
602	 * this case */
603	.macro		f_extend	pte,tmp
604	extrd,s		\pte,42,4,\tmp
605	addi,<>		1,\tmp,%r0
606	extrd,s		\pte,63,25,\pte
607	.endm
608
609	/* The alias region is an 8MB aligned 16MB to do clear and
610	 * copy user pages at addresses congruent with the user
611	 * virtual address.
612	 *
613	 * To use the alias page, you set %r26 up with the to TLB
614	 * entry (identifying the physical page) and %r23 up with
615	 * the from tlb entry (or nothing if only a to entry---for
616	 * clear_user_page_asm) */
617	.macro		do_alias	spc,tmp,tmp1,va,pte,prot,fault
618	cmpib,COND(<>),n 0,\spc,\fault
619	ldil		L%(TMPALIAS_MAP_START),\tmp
620#if defined(CONFIG_64BIT) && (TMPALIAS_MAP_START >= 0x80000000)
621	/* on LP64, ldi will sign extend into the upper 32 bits,
622	 * which is behaviour we don't want */
623	depdi		0,31,32,\tmp
624#endif
625	copy		\va,\tmp1
626	DEPI		0,31,23,\tmp1
627	cmpb,COND(<>),n	\tmp,\tmp1,\fault
628	ldi		(_PAGE_DIRTY|_PAGE_WRITE|_PAGE_READ),\prot
629	depd,z		\prot,8,7,\prot
630	/*
631	 * OK, it is in the temp alias region, check whether "from" or "to".
632	 * Check "subtle" note in pacache.S re: r23/r26.
633	 */
634#ifdef CONFIG_64BIT
635	extrd,u,*=	\va,41,1,%r0
636#else
637	extrw,u,=	\va,9,1,%r0
638#endif
639	or,COND(tr)	%r23,%r0,\pte
640	or		%r26,%r0,\pte
641	.endm
642
643
644	/*
645	 * Align fault_vector_20 on 4K boundary so that both
646	 * fault_vector_11 and fault_vector_20 are on the
647	 * same page. This is only necessary as long as we
648	 * write protect the kernel text, which we may stop
649	 * doing once we use large page translations to cover
650	 * the static part of the kernel address space.
651	 */
652
653	.text
654
655	.align 4096
656
657ENTRY(fault_vector_20)
658	/* First vector is invalid (0) */
659	.ascii	"cows can fly"
660	.byte 0
661	.align 32
662
663	hpmc		 1
664	def		 2
665	def		 3
666	extint		 4
667	def		 5
668	itlb_20		 6
669	def		 7
670	def		 8
671	def              9
672	def		10
673	def		11
674	def		12
675	def		13
676	def		14
677	dtlb_20		15
678#if 0
679	naitlb_20	16
680#else
681	def             16
682#endif
683	nadtlb_20	17
684	def		18
685	def		19
686	dbit_20		20
687	def		21
688	def		22
689	def		23
690	def		24
691	def		25
692	def		26
693	def		27
694	def		28
695	def		29
696	def		30
697	def		31
698END(fault_vector_20)
699
700#ifndef CONFIG_64BIT
701
702	.align 2048
703
704ENTRY(fault_vector_11)
705	/* First vector is invalid (0) */
706	.ascii	"cows can fly"
707	.byte 0
708	.align 32
709
710	hpmc		 1
711	def		 2
712	def		 3
713	extint		 4
714	def		 5
715	itlb_11		 6
716	def		 7
717	def		 8
718	def              9
719	def		10
720	def		11
721	def		12
722	def		13
723	def		14
724	dtlb_11		15
725#if 0
726	naitlb_11	16
727#else
728	def             16
729#endif
730	nadtlb_11	17
731	def		18
732	def		19
733	dbit_11		20
734	def		21
735	def		22
736	def		23
737	def		24
738	def		25
739	def		26
740	def		27
741	def		28
742	def		29
743	def		30
744	def		31
745END(fault_vector_11)
746
747#endif
748
749	.import		handle_interruption,code
750	.import		do_cpu_irq_mask,code
751
752	/*
753	 * r26 = function to be called
754	 * r25 = argument to pass in
755	 * r24 = flags for do_fork()
756	 *
757	 * Kernel threads don't ever return, so they don't need
758	 * a true register context. We just save away the arguments
759	 * for copy_thread/ret_ to properly set up the child.
760	 */
761
762#define CLONE_VM 0x100	/* Must agree with <linux/sched.h> */
763#define CLONE_UNTRACED 0x00800000
764
765	.import do_fork
766ENTRY(__kernel_thread)
767	STREG	%r2, -RP_OFFSET(%r30)
768
769	copy	%r30, %r1
770	ldo	PT_SZ_ALGN(%r30),%r30
771#ifdef CONFIG_64BIT
772	/* Yo, function pointers in wide mode are little structs... -PB */
773	ldd	24(%r26), %r2
774	STREG	%r2, PT_GR27(%r1)	/* Store childs %dp */
775	ldd	16(%r26), %r26
776
777	STREG	%r22, PT_GR22(%r1)	/* save r22 (arg5) */
778	copy	%r0, %r22		/* user_tid */
779#endif
780	STREG	%r26, PT_GR26(%r1)  /* Store function & argument for child */
781	STREG	%r25, PT_GR25(%r1)
782	ldil	L%CLONE_UNTRACED, %r26
783	ldo	CLONE_VM(%r26), %r26   /* Force CLONE_VM since only init_mm */
784	or	%r26, %r24, %r26      /* will have kernel mappings.	 */
785	ldi	1, %r25			/* stack_start, signals kernel thread */
786	stw	%r0, -52(%r30)	     	/* user_tid */
787#ifdef CONFIG_64BIT
788	ldo	-16(%r30),%r29		/* Reference param save area */
789#endif
790	BL	do_fork, %r2
791	copy	%r1, %r24		/* pt_regs */
792
793	/* Parent Returns here */
794
795	LDREG	-PT_SZ_ALGN-RP_OFFSET(%r30), %r2
796	ldo	-PT_SZ_ALGN(%r30), %r30
797	bv	%r0(%r2)
798	nop
799ENDPROC(__kernel_thread)
800
801	/*
802	 * Child Returns here
803	 *
804	 * copy_thread moved args from temp save area set up above
805	 * into task save area.
806	 */
807
808ENTRY(ret_from_kernel_thread)
809
810	/* Call schedule_tail first though */
811	BL	schedule_tail, %r2
812	nop
813
814	LDREG	TI_TASK-THREAD_SZ_ALGN(%r30), %r1
815	LDREG	TASK_PT_GR25(%r1), %r26
816#ifdef CONFIG_64BIT
817	LDREG	TASK_PT_GR27(%r1), %r27
818	LDREG	TASK_PT_GR22(%r1), %r22
819#endif
820	LDREG	TASK_PT_GR26(%r1), %r1
821	ble	0(%sr7, %r1)
822	copy	%r31, %r2
823
824#ifdef CONFIG_64BIT
825	ldo	-16(%r30),%r29		/* Reference param save area */
826	loadgp				/* Thread could have been in a module */
827#endif
828#ifndef CONFIG_64BIT
829	b	sys_exit
830#else
831	load32	sys_exit, %r1
832	bv	%r0(%r1)
833#endif
834	ldi	0, %r26
835ENDPROC(ret_from_kernel_thread)
836
837	.import	sys_execve, code
838ENTRY(__execve)
839	copy	%r2, %r15
840	copy	%r30, %r16
841	ldo	PT_SZ_ALGN(%r30), %r30
842	STREG	%r26, PT_GR26(%r16)
843	STREG	%r25, PT_GR25(%r16)
844	STREG	%r24, PT_GR24(%r16)
845#ifdef CONFIG_64BIT
846	ldo	-16(%r30),%r29		/* Reference param save area */
847#endif
848	BL	sys_execve, %r2
849	copy	%r16, %r26
850
851	cmpib,=,n 0,%r28,intr_return    /* forward */
852
853	/* yes, this will trap and die. */
854	copy	%r15, %r2
855	copy	%r16, %r30
856	bv	%r0(%r2)
857	nop
858ENDPROC(__execve)
859
860
861	/*
862	 * struct task_struct *_switch_to(struct task_struct *prev,
863	 *	struct task_struct *next)
864	 *
865	 * switch kernel stacks and return prev */
866ENTRY(_switch_to)
867	STREG	 %r2, -RP_OFFSET(%r30)
868
869	callee_save_float
870	callee_save
871
872	load32	_switch_to_ret, %r2
873
874	STREG	%r2, TASK_PT_KPC(%r26)
875	LDREG	TASK_PT_KPC(%r25), %r2
876
877	STREG	%r30, TASK_PT_KSP(%r26)
878	LDREG	TASK_PT_KSP(%r25), %r30
879	LDREG	TASK_THREAD_INFO(%r25), %r25
880	bv	%r0(%r2)
881	mtctl   %r25,%cr30
882
883_switch_to_ret:
884	mtctl	%r0, %cr0		/* Needed for single stepping */
885	callee_rest
886	callee_rest_float
887
888	LDREG	-RP_OFFSET(%r30), %r2
889	bv	%r0(%r2)
890	copy	%r26, %r28
891ENDPROC(_switch_to)
892
893	/*
894	 * Common rfi return path for interruptions, kernel execve, and
895	 * sys_rt_sigreturn (sometimes).  The sys_rt_sigreturn syscall will
896	 * return via this path if the signal was received when the process
897	 * was running; if the process was blocked on a syscall then the
898	 * normal syscall_exit path is used.  All syscalls for traced
899	 * proceses exit via intr_restore.
900	 *
901	 * XXX If any syscalls that change a processes space id ever exit
902	 * this way, then we will need to copy %sr3 in to PT_SR[3..7], and
903	 * adjust IASQ[0..1].
904	 *
905	 */
906
907	.align 4096
908
909ENTRY(syscall_exit_rfi)
910	mfctl   %cr30,%r16
911	LDREG	TI_TASK(%r16), %r16	/* thread_info -> task_struct */
912	ldo	TASK_REGS(%r16),%r16
913	/* Force iaoq to userspace, as the user has had access to our current
914	 * context via sigcontext. Also Filter the PSW for the same reason.
915	 */
916	LDREG	PT_IAOQ0(%r16),%r19
917	depi	3,31,2,%r19
918	STREG	%r19,PT_IAOQ0(%r16)
919	LDREG	PT_IAOQ1(%r16),%r19
920	depi	3,31,2,%r19
921	STREG	%r19,PT_IAOQ1(%r16)
922	LDREG   PT_PSW(%r16),%r19
923	load32	USER_PSW_MASK,%r1
924#ifdef CONFIG_64BIT
925	load32	USER_PSW_HI_MASK,%r20
926	depd    %r20,31,32,%r1
927#endif
928	and     %r19,%r1,%r19 /* Mask out bits that user shouldn't play with */
929	load32	USER_PSW,%r1
930	or      %r19,%r1,%r19 /* Make sure default USER_PSW bits are set */
931	STREG   %r19,PT_PSW(%r16)
932
933	/*
934	 * If we aren't being traced, we never saved space registers
935	 * (we don't store them in the sigcontext), so set them
936	 * to "proper" values now (otherwise we'll wind up restoring
937	 * whatever was last stored in the task structure, which might
938	 * be inconsistent if an interrupt occured while on the gateway
939	 * page). Note that we may be "trashing" values the user put in
940	 * them, but we don't support the user changing them.
941	 */
942
943	STREG   %r0,PT_SR2(%r16)
944	mfsp    %sr3,%r19
945	STREG   %r19,PT_SR0(%r16)
946	STREG   %r19,PT_SR1(%r16)
947	STREG   %r19,PT_SR3(%r16)
948	STREG   %r19,PT_SR4(%r16)
949	STREG   %r19,PT_SR5(%r16)
950	STREG   %r19,PT_SR6(%r16)
951	STREG   %r19,PT_SR7(%r16)
952
953intr_return:
954	/* NOTE: Need to enable interrupts incase we schedule. */
955	ssm     PSW_SM_I, %r0
956
957intr_check_resched:
958
959	/* check for reschedule */
960	mfctl   %cr30,%r1
961	LDREG   TI_FLAGS(%r1),%r19	/* sched.h: TIF_NEED_RESCHED */
962	bb,<,n	%r19,31-TIF_NEED_RESCHED,intr_do_resched /* forward */
963
964	.import do_notify_resume,code
965intr_check_sig:
966	/* As above */
967	mfctl   %cr30,%r1
968	LDREG	TI_FLAGS(%r1),%r19
969	ldi	(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK), %r20
970	and,COND(<>)	%r19, %r20, %r0
971	b,n	intr_restore	/* skip past if we've nothing to do */
972
973	/* This check is critical to having LWS
974	 * working. The IASQ is zero on the gateway
975	 * page and we cannot deliver any signals until
976	 * we get off the gateway page.
977	 *
978	 * Only do signals if we are returning to user space
979	 */
980	LDREG	PT_IASQ0(%r16), %r20
981	CMPIB=,n 0,%r20,intr_restore /* backward */
982	LDREG	PT_IASQ1(%r16), %r20
983	CMPIB=,n 0,%r20,intr_restore /* backward */
984
985	copy	%r0, %r25			/* long in_syscall = 0 */
986#ifdef CONFIG_64BIT
987	ldo	-16(%r30),%r29			/* Reference param save area */
988#endif
989
990	BL	do_notify_resume,%r2
991	copy	%r16, %r26			/* struct pt_regs *regs */
992
993	b,n	intr_check_sig
994
995intr_restore:
996	copy            %r16,%r29
997	ldo             PT_FR31(%r29),%r1
998	rest_fp         %r1
999	rest_general    %r29
1000
1001	/* inverse of virt_map */
1002	pcxt_ssm_bug
1003	rsm             PSW_SM_QUIET,%r0	/* prepare for rfi */
1004	tophys_r1       %r29
1005
1006	/* Restore space id's and special cr's from PT_REGS
1007	 * structure pointed to by r29
1008	 */
1009	rest_specials	%r29
1010
1011	/* IMPORTANT: rest_stack restores r29 last (we are using it)!
1012	 * It also restores r1 and r30.
1013	 */
1014	rest_stack
1015
1016	rfi
1017	nop
1018	nop
1019	nop
1020	nop
1021	nop
1022	nop
1023	nop
1024	nop
1025
1026#ifndef CONFIG_PREEMPT
1027# define intr_do_preempt	intr_restore
1028#endif /* !CONFIG_PREEMPT */
1029
1030	.import schedule,code
1031intr_do_resched:
1032	/* Only call schedule on return to userspace. If we're returning
1033	 * to kernel space, we may schedule if CONFIG_PREEMPT, otherwise
1034	 * we jump back to intr_restore.
1035	 */
1036	LDREG	PT_IASQ0(%r16), %r20
1037	CMPIB=	0, %r20, intr_do_preempt
1038	nop
1039	LDREG	PT_IASQ1(%r16), %r20
1040	CMPIB=	0, %r20, intr_do_preempt
1041	nop
1042
1043#ifdef CONFIG_64BIT
1044	ldo	-16(%r30),%r29		/* Reference param save area */
1045#endif
1046
1047	ldil	L%intr_check_sig, %r2
1048#ifndef CONFIG_64BIT
1049	b	schedule
1050#else
1051	load32	schedule, %r20
1052	bv	%r0(%r20)
1053#endif
1054	ldo	R%intr_check_sig(%r2), %r2
1055
1056	/* preempt the current task on returning to kernel
1057	 * mode from an interrupt, iff need_resched is set,
1058	 * and preempt_count is 0. otherwise, we continue on
1059	 * our merry way back to the current running task.
1060	 */
1061#ifdef CONFIG_PREEMPT
1062	.import preempt_schedule_irq,code
1063intr_do_preempt:
1064	rsm	PSW_SM_I, %r0		/* disable interrupts */
1065
1066	/* current_thread_info()->preempt_count */
1067	mfctl	%cr30, %r1
1068	LDREG	TI_PRE_COUNT(%r1), %r19
1069	CMPIB<>	0, %r19, intr_restore	/* if preempt_count > 0 */
1070	nop				/* prev insn branched backwards */
1071
1072	/* check if we interrupted a critical path */
1073	LDREG	PT_PSW(%r16), %r20
1074	bb,<,n	%r20, 31 - PSW_SM_I, intr_restore
1075	nop
1076
1077	BL	preempt_schedule_irq, %r2
1078	nop
1079
1080	b,n	intr_restore		/* ssm PSW_SM_I done by intr_restore */
1081#endif /* CONFIG_PREEMPT */
1082
1083	/*
1084	 * External interrupts.
1085	 */
1086
1087intr_extint:
1088	CMPIB=,n 0,%r16,1f
1089	get_stack_use_cr30
1090	b,n 3f
1091
10921:
1093#if 0  /* Interrupt Stack support not working yet! */
1094	mfctl	%cr31,%r1
1095	copy	%r30,%r17
1096	/* FIXME! depi below has hardcoded idea of interrupt stack size (32k)*/
1097	DEPI	0,31,15,%r17
1098	CMPB=,n	%r1,%r17,2f
1099	get_stack_use_cr31
1100	b,n 3f
1101#endif
11022:
1103	get_stack_use_r30
1104
11053:
1106	save_specials	%r29
1107	virt_map
1108	save_general	%r29
1109
1110	ldo	PT_FR0(%r29), %r24
1111	save_fp	%r24
1112
1113	loadgp
1114
1115	copy	%r29, %r26	/* arg0 is pt_regs */
1116	copy	%r29, %r16	/* save pt_regs */
1117
1118	ldil	L%intr_return, %r2
1119
1120#ifdef CONFIG_64BIT
1121	ldo	-16(%r30),%r29	/* Reference param save area */
1122#endif
1123
1124	b	do_cpu_irq_mask
1125	ldo	R%intr_return(%r2), %r2	/* return to intr_return, not here */
1126ENDPROC(syscall_exit_rfi)
1127
1128
1129	/* Generic interruptions (illegal insn, unaligned, page fault, etc) */
1130
1131ENTRY(intr_save)		/* for os_hpmc */
1132	mfsp    %sr7,%r16
1133	CMPIB=,n 0,%r16,1f
1134	get_stack_use_cr30
1135	b	2f
1136	copy    %r8,%r26
1137
11381:
1139	get_stack_use_r30
1140	copy    %r8,%r26
1141
11422:
1143	save_specials	%r29
1144
1145	/* If this trap is a itlb miss, skip saving/adjusting isr/ior */
1146
1147	/*
1148	 * FIXME: 1) Use a #define for the hardwired "6" below (and in
1149	 *           traps.c.
1150	 *        2) Once we start executing code above 4 Gb, we need
1151	 *           to adjust iasq/iaoq here in the same way we
1152	 *           adjust isr/ior below.
1153	 */
1154
1155	CMPIB=,n        6,%r26,skip_save_ior
1156
1157
1158	mfctl           %cr20, %r16 /* isr */
1159	nop		/* serialize mfctl on PA 2.0 to avoid 4 cycle penalty */
1160	mfctl           %cr21, %r17 /* ior */
1161
1162
1163#ifdef CONFIG_64BIT
1164	/*
1165	 * If the interrupted code was running with W bit off (32 bit),
1166	 * clear the b bits (bits 0 & 1) in the ior.
1167	 * save_specials left ipsw value in r8 for us to test.
1168	 */
1169	extrd,u,*<>     %r8,PSW_W_BIT,1,%r0
1170	depdi           0,1,2,%r17
1171
1172	/*
1173	 * FIXME: This code has hardwired assumptions about the split
1174	 *        between space bits and offset bits. This will change
1175	 *        when we allow alternate page sizes.
1176	 */
1177
1178	/* adjust isr/ior. */
1179	extrd,u         %r16,63,SPACEID_SHIFT,%r1	/* get high bits from isr for ior */
1180	depd            %r1,31,SPACEID_SHIFT,%r17	/* deposit them into ior */
1181	depdi           0,63,SPACEID_SHIFT,%r16		/* clear them from isr */
1182#endif
1183	STREG           %r16, PT_ISR(%r29)
1184	STREG           %r17, PT_IOR(%r29)
1185
1186
1187skip_save_ior:
1188	virt_map
1189	save_general	%r29
1190
1191	ldo		PT_FR0(%r29), %r25
1192	save_fp		%r25
1193
1194	loadgp
1195
1196	copy		%r29, %r25	/* arg1 is pt_regs */
1197#ifdef CONFIG_64BIT
1198	ldo		-16(%r30),%r29	/* Reference param save area */
1199#endif
1200
1201	ldil		L%intr_check_sig, %r2
1202	copy		%r25, %r16	/* save pt_regs */
1203
1204	b		handle_interruption
1205	ldo		R%intr_check_sig(%r2), %r2
1206ENDPROC(intr_save)
1207
1208
1209	/*
1210	 * Note for all tlb miss handlers:
1211	 *
1212	 * cr24 contains a pointer to the kernel address space
1213	 * page directory.
1214	 *
1215	 * cr25 contains a pointer to the current user address
1216	 * space page directory.
1217	 *
1218	 * sr3 will contain the space id of the user address space
1219	 * of the current running thread while that thread is
1220	 * running in the kernel.
1221	 */
1222
1223	/*
1224	 * register number allocations.  Note that these are all
1225	 * in the shadowed registers
1226	 */
1227
1228	t0 = r1		/* temporary register 0 */
1229	va = r8		/* virtual address for which the trap occured */
1230	t1 = r9		/* temporary register 1 */
1231	pte  = r16	/* pte/phys page # */
1232	prot = r17	/* prot bits */
1233	spc  = r24	/* space for which the trap occured */
1234	ptp = r25	/* page directory/page table pointer */
1235
1236#ifdef CONFIG_64BIT
1237
1238dtlb_miss_20w:
1239	space_adjust	spc,va,t0
1240	get_pgd		spc,ptp
1241	space_check	spc,t0,dtlb_fault
1242
1243	L3_ptep		ptp,pte,t0,va,dtlb_check_alias_20w
1244
1245	update_ptep	ptp,pte,t0,t1
1246
1247	make_insert_tlb	spc,pte,prot
1248
1249	idtlbt          pte,prot
1250
1251	rfir
1252	nop
1253
1254dtlb_check_alias_20w:
1255	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault
1256
1257	idtlbt          pte,prot
1258
1259	rfir
1260	nop
1261
1262nadtlb_miss_20w:
1263	space_adjust	spc,va,t0
1264	get_pgd		spc,ptp
1265	space_check	spc,t0,nadtlb_fault
1266
1267	L3_ptep		ptp,pte,t0,va,nadtlb_check_flush_20w
1268
1269	update_ptep	ptp,pte,t0,t1
1270
1271	make_insert_tlb	spc,pte,prot
1272
1273	idtlbt          pte,prot
1274
1275	rfir
1276	nop
1277
1278nadtlb_check_flush_20w:
1279	bb,>=,n          pte,_PAGE_FLUSH_BIT,nadtlb_emulate
1280
1281	/* Insert a "flush only" translation */
1282
1283	depdi,z         7,7,3,prot
1284	depdi           1,10,1,prot
1285
1286	/* Get rid of prot bits and convert to page addr for idtlbt */
1287
1288	depdi		0,63,12,pte
1289	extrd,u         pte,56,52,pte
1290	idtlbt          pte,prot
1291
1292	rfir
1293	nop
1294
1295#else
1296
1297dtlb_miss_11:
1298	get_pgd		spc,ptp
1299
1300	space_check	spc,t0,dtlb_fault
1301
1302	L2_ptep		ptp,pte,t0,va,dtlb_check_alias_11
1303
1304	update_ptep	ptp,pte,t0,t1
1305
1306	make_insert_tlb_11	spc,pte,prot
1307
1308	mfsp		%sr1,t0  /* Save sr1 so we can use it in tlb inserts */
1309	mtsp		spc,%sr1
1310
1311	idtlba		pte,(%sr1,va)
1312	idtlbp		prot,(%sr1,va)
1313
1314	mtsp		t0, %sr1	/* Restore sr1 */
1315
1316	rfir
1317	nop
1318
1319dtlb_check_alias_11:
1320
1321	/* Check to see if fault is in the temporary alias region */
1322
1323	cmpib,<>,n      0,spc,dtlb_fault /* forward */
1324	ldil            L%(TMPALIAS_MAP_START),t0
1325	copy            va,t1
1326	depwi           0,31,23,t1
1327	cmpb,<>,n       t0,t1,dtlb_fault /* forward */
1328	ldi             (_PAGE_DIRTY|_PAGE_WRITE|_PAGE_READ),prot
1329	depw,z          prot,8,7,prot
1330
1331	/*
1332	 * OK, it is in the temp alias region, check whether "from" or "to".
1333	 * Check "subtle" note in pacache.S re: r23/r26.
1334	 */
1335
1336	extrw,u,=       va,9,1,r0
1337	or,tr           %r23,%r0,pte    /* If "from" use "from" page */
1338	or              %r26,%r0,pte    /* else "to", use "to" page  */
1339
1340	idtlba          pte,(va)
1341	idtlbp          prot,(va)
1342
1343	rfir
1344	nop
1345
1346nadtlb_miss_11:
1347	get_pgd		spc,ptp
1348
1349	space_check	spc,t0,nadtlb_fault
1350
1351	L2_ptep		ptp,pte,t0,va,nadtlb_check_flush_11
1352
1353	update_ptep	ptp,pte,t0,t1
1354
1355	make_insert_tlb_11	spc,pte,prot
1356
1357
1358	mfsp		%sr1,t0  /* Save sr1 so we can use it in tlb inserts */
1359	mtsp		spc,%sr1
1360
1361	idtlba		pte,(%sr1,va)
1362	idtlbp		prot,(%sr1,va)
1363
1364	mtsp		t0, %sr1	/* Restore sr1 */
1365
1366	rfir
1367	nop
1368
1369nadtlb_check_flush_11:
1370	bb,>=,n          pte,_PAGE_FLUSH_BIT,nadtlb_emulate
1371
1372	/* Insert a "flush only" translation */
1373
1374	zdepi           7,7,3,prot
1375	depi            1,10,1,prot
1376
1377	/* Get rid of prot bits and convert to page addr for idtlba */
1378
1379	depi		0,31,12,pte
1380	extru		pte,24,25,pte
1381
1382	mfsp		%sr1,t0  /* Save sr1 so we can use it in tlb inserts */
1383	mtsp		spc,%sr1
1384
1385	idtlba		pte,(%sr1,va)
1386	idtlbp		prot,(%sr1,va)
1387
1388	mtsp		t0, %sr1	/* Restore sr1 */
1389
1390	rfir
1391	nop
1392
1393dtlb_miss_20:
1394	space_adjust	spc,va,t0
1395	get_pgd		spc,ptp
1396	space_check	spc,t0,dtlb_fault
1397
1398	L2_ptep		ptp,pte,t0,va,dtlb_check_alias_20
1399
1400	update_ptep	ptp,pte,t0,t1
1401
1402	make_insert_tlb	spc,pte,prot
1403
1404	f_extend	pte,t0
1405
1406	idtlbt          pte,prot
1407
1408	rfir
1409	nop
1410
1411dtlb_check_alias_20:
1412	do_alias	spc,t0,t1,va,pte,prot,dtlb_fault
1413
1414	idtlbt          pte,prot
1415
1416	rfir
1417	nop
1418
1419nadtlb_miss_20:
1420	get_pgd		spc,ptp
1421
1422	space_check	spc,t0,nadtlb_fault
1423
1424	L2_ptep		ptp,pte,t0,va,nadtlb_check_flush_20
1425
1426	update_ptep	ptp,pte,t0,t1
1427
1428	make_insert_tlb	spc,pte,prot
1429
1430	f_extend	pte,t0
1431
1432        idtlbt          pte,prot
1433
1434	rfir
1435	nop
1436
1437nadtlb_check_flush_20:
1438	bb,>=,n          pte,_PAGE_FLUSH_BIT,nadtlb_emulate
1439
1440	/* Insert a "flush only" translation */
1441
1442	depdi,z         7,7,3,prot
1443	depdi           1,10,1,prot
1444
1445	/* Get rid of prot bits and convert to page addr for idtlbt */
1446
1447	depdi		0,63,12,pte
1448	extrd,u         pte,56,32,pte
1449	idtlbt          pte,prot
1450
1451	rfir
1452	nop
1453#endif
1454
1455nadtlb_emulate:
1456
1457	/*
1458	 * Non access misses can be caused by fdc,fic,pdc,lpa,probe and
1459	 * probei instructions. We don't want to fault for these
1460	 * instructions (not only does it not make sense, it can cause
1461	 * deadlocks, since some flushes are done with the mmap
1462	 * semaphore held). If the translation doesn't exist, we can't
1463	 * insert a translation, so have to emulate the side effects
1464	 * of the instruction. Since we don't insert a translation
1465	 * we can get a lot of faults during a flush loop, so it makes
1466	 * sense to try to do it here with minimum overhead. We only
1467	 * emulate fdc,fic,pdc,probew,prober instructions whose base
1468	 * and index registers are not shadowed. We defer everything
1469	 * else to the "slow" path.
1470	 */
1471
1472	mfctl           %cr19,%r9 /* Get iir */
1473
1474	/* PA 2.0 Arch Ref. Book pg 382 has a good description of the insn bits.
1475	   Checks for fdc,fdce,pdc,"fic,4f",prober,probeir,probew, probeiw */
1476
1477	/* Checks for fdc,fdce,pdc,"fic,4f" only */
1478	ldi             0x280,%r16
1479	and             %r9,%r16,%r17
1480	cmpb,<>,n       %r16,%r17,nadtlb_probe_check
1481	bb,>=,n         %r9,26,nadtlb_nullify  /* m bit not set, just nullify */
1482	BL		get_register,%r25
1483	extrw,u         %r9,15,5,%r8           /* Get index register # */
1484	CMPIB=,n        -1,%r1,nadtlb_fault    /* have to use slow path */
1485	copy            %r1,%r24
1486	BL		get_register,%r25
1487	extrw,u         %r9,10,5,%r8           /* Get base register # */
1488	CMPIB=,n        -1,%r1,nadtlb_fault    /* have to use slow path */
1489	BL		set_register,%r25
1490	add,l           %r1,%r24,%r1           /* doesn't affect c/b bits */
1491
1492nadtlb_nullify:
1493	mfctl           %ipsw,%r8
1494	ldil            L%PSW_N,%r9
1495	or              %r8,%r9,%r8            /* Set PSW_N */
1496	mtctl           %r8,%ipsw
1497
1498	rfir
1499	nop
1500
1501	/*
1502		When there is no translation for the probe address then we
1503		must nullify the insn and return zero in the target regsiter.
1504		This will indicate to the calling code that it does not have
1505		write/read privileges to this address.
1506
1507		This should technically work for prober and probew in PA 1.1,
1508		and also probe,r and probe,w in PA 2.0
1509
1510		WARNING: USE ONLY NON-SHADOW REGISTERS WITH PROBE INSN!
1511		THE SLOW-PATH EMULATION HAS NOT BEEN WRITTEN YET.
1512
1513	*/
1514nadtlb_probe_check:
1515	ldi             0x80,%r16
1516	and             %r9,%r16,%r17
1517	cmpb,<>,n       %r16,%r17,nadtlb_fault /* Must be probe,[rw]*/
1518	BL              get_register,%r25      /* Find the target register */
1519	extrw,u         %r9,31,5,%r8           /* Get target register */
1520	CMPIB=,n        -1,%r1,nadtlb_fault    /* have to use slow path */
1521	BL		set_register,%r25
1522	copy            %r0,%r1                /* Write zero to target register */
1523	b nadtlb_nullify                       /* Nullify return insn */
1524	nop
1525
1526
1527#ifdef CONFIG_64BIT
1528itlb_miss_20w:
1529
1530	/*
1531	 * I miss is a little different, since we allow users to fault
1532	 * on the gateway page which is in the kernel address space.
1533	 */
1534
1535	space_adjust	spc,va,t0
1536	get_pgd		spc,ptp
1537	space_check	spc,t0,itlb_fault
1538
1539	L3_ptep		ptp,pte,t0,va,itlb_fault
1540
1541	update_ptep	ptp,pte,t0,t1
1542
1543	make_insert_tlb	spc,pte,prot
1544
1545	iitlbt          pte,prot
1546
1547	rfir
1548	nop
1549
1550#else
1551
1552itlb_miss_11:
1553	get_pgd		spc,ptp
1554
1555	space_check	spc,t0,itlb_fault
1556
1557	L2_ptep		ptp,pte,t0,va,itlb_fault
1558
1559	update_ptep	ptp,pte,t0,t1
1560
1561	make_insert_tlb_11	spc,pte,prot
1562
1563	mfsp		%sr1,t0  /* Save sr1 so we can use it in tlb inserts */
1564	mtsp		spc,%sr1
1565
1566	iitlba		pte,(%sr1,va)
1567	iitlbp		prot,(%sr1,va)
1568
1569	mtsp		t0, %sr1	/* Restore sr1 */
1570
1571	rfir
1572	nop
1573
1574itlb_miss_20:
1575	get_pgd		spc,ptp
1576
1577	space_check	spc,t0,itlb_fault
1578
1579	L2_ptep		ptp,pte,t0,va,itlb_fault
1580
1581	update_ptep	ptp,pte,t0,t1
1582
1583	make_insert_tlb	spc,pte,prot
1584
1585	f_extend	pte,t0
1586
1587	iitlbt          pte,prot
1588
1589	rfir
1590	nop
1591
1592#endif
1593
1594#ifdef CONFIG_64BIT
1595
1596dbit_trap_20w:
1597	space_adjust	spc,va,t0
1598	get_pgd		spc,ptp
1599	space_check	spc,t0,dbit_fault
1600
1601	L3_ptep		ptp,pte,t0,va,dbit_fault
1602
1603#ifdef CONFIG_SMP
1604	CMPIB=,n        0,spc,dbit_nolock_20w
1605	load32		PA(pa_dbit_lock),t0
1606
1607dbit_spin_20w:
1608	LDCW		0(t0),t1
1609	cmpib,=         0,t1,dbit_spin_20w
1610	nop
1611
1612dbit_nolock_20w:
1613#endif
1614	update_dirty	ptp,pte,t1
1615
1616	make_insert_tlb	spc,pte,prot
1617
1618	idtlbt          pte,prot
1619#ifdef CONFIG_SMP
1620	CMPIB=,n        0,spc,dbit_nounlock_20w
1621	ldi             1,t1
1622	stw             t1,0(t0)
1623
1624dbit_nounlock_20w:
1625#endif
1626
1627	rfir
1628	nop
1629#else
1630
1631dbit_trap_11:
1632
1633	get_pgd		spc,ptp
1634
1635	space_check	spc,t0,dbit_fault
1636
1637	L2_ptep		ptp,pte,t0,va,dbit_fault
1638
1639#ifdef CONFIG_SMP
1640	CMPIB=,n        0,spc,dbit_nolock_11
1641	load32		PA(pa_dbit_lock),t0
1642
1643dbit_spin_11:
1644	LDCW		0(t0),t1
1645	cmpib,=         0,t1,dbit_spin_11
1646	nop
1647
1648dbit_nolock_11:
1649#endif
1650	update_dirty	ptp,pte,t1
1651
1652	make_insert_tlb_11	spc,pte,prot
1653
1654	mfsp            %sr1,t1  /* Save sr1 so we can use it in tlb inserts */
1655	mtsp		spc,%sr1
1656
1657	idtlba		pte,(%sr1,va)
1658	idtlbp		prot,(%sr1,va)
1659
1660	mtsp            t1, %sr1     /* Restore sr1 */
1661#ifdef CONFIG_SMP
1662	CMPIB=,n        0,spc,dbit_nounlock_11
1663	ldi             1,t1
1664	stw             t1,0(t0)
1665
1666dbit_nounlock_11:
1667#endif
1668
1669	rfir
1670	nop
1671
1672dbit_trap_20:
1673	get_pgd		spc,ptp
1674
1675	space_check	spc,t0,dbit_fault
1676
1677	L2_ptep		ptp,pte,t0,va,dbit_fault
1678
1679#ifdef CONFIG_SMP
1680	CMPIB=,n        0,spc,dbit_nolock_20
1681	load32		PA(pa_dbit_lock),t0
1682
1683dbit_spin_20:
1684	LDCW		0(t0),t1
1685	cmpib,=         0,t1,dbit_spin_20
1686	nop
1687
1688dbit_nolock_20:
1689#endif
1690	update_dirty	ptp,pte,t1
1691
1692	make_insert_tlb	spc,pte,prot
1693
1694	f_extend	pte,t1
1695
1696        idtlbt          pte,prot
1697
1698#ifdef CONFIG_SMP
1699	CMPIB=,n        0,spc,dbit_nounlock_20
1700	ldi             1,t1
1701	stw             t1,0(t0)
1702
1703dbit_nounlock_20:
1704#endif
1705
1706	rfir
1707	nop
1708#endif
1709
1710	.import handle_interruption,code
1711
1712kernel_bad_space:
1713	b               intr_save
1714	ldi             31,%r8  /* Use an unused code */
1715
1716dbit_fault:
1717	b               intr_save
1718	ldi             20,%r8
1719
1720itlb_fault:
1721	b               intr_save
1722	ldi             6,%r8
1723
1724nadtlb_fault:
1725	b               intr_save
1726	ldi             17,%r8
1727
1728dtlb_fault:
1729	b               intr_save
1730	ldi             15,%r8
1731
1732	/* Register saving semantics for system calls:
1733
1734	   %r1		   clobbered by system call macro in userspace
1735	   %r2		   saved in PT_REGS by gateway page
1736	   %r3  - %r18	   preserved by C code (saved by signal code)
1737	   %r19 - %r20	   saved in PT_REGS by gateway page
1738	   %r21 - %r22	   non-standard syscall args
1739			   stored in kernel stack by gateway page
1740	   %r23 - %r26	   arg3-arg0, saved in PT_REGS by gateway page
1741	   %r27 - %r30	   saved in PT_REGS by gateway page
1742	   %r31		   syscall return pointer
1743	 */
1744
1745	/* Floating point registers (FIXME: what do we do with these?)
1746
1747	   %fr0  - %fr3	   status/exception, not preserved
1748	   %fr4  - %fr7	   arguments
1749	   %fr8	 - %fr11   not preserved by C code
1750	   %fr12 - %fr21   preserved by C code
1751	   %fr22 - %fr31   not preserved by C code
1752	 */
1753
1754	.macro	reg_save regs
1755	STREG	%r3, PT_GR3(\regs)
1756	STREG	%r4, PT_GR4(\regs)
1757	STREG	%r5, PT_GR5(\regs)
1758	STREG	%r6, PT_GR6(\regs)
1759	STREG	%r7, PT_GR7(\regs)
1760	STREG	%r8, PT_GR8(\regs)
1761	STREG	%r9, PT_GR9(\regs)
1762	STREG   %r10,PT_GR10(\regs)
1763	STREG   %r11,PT_GR11(\regs)
1764	STREG   %r12,PT_GR12(\regs)
1765	STREG   %r13,PT_GR13(\regs)
1766	STREG   %r14,PT_GR14(\regs)
1767	STREG   %r15,PT_GR15(\regs)
1768	STREG   %r16,PT_GR16(\regs)
1769	STREG   %r17,PT_GR17(\regs)
1770	STREG   %r18,PT_GR18(\regs)
1771	.endm
1772
1773	.macro	reg_restore regs
1774	LDREG	PT_GR3(\regs), %r3
1775	LDREG	PT_GR4(\regs), %r4
1776	LDREG	PT_GR5(\regs), %r5
1777	LDREG	PT_GR6(\regs), %r6
1778	LDREG	PT_GR7(\regs), %r7
1779	LDREG	PT_GR8(\regs), %r8
1780	LDREG	PT_GR9(\regs), %r9
1781	LDREG   PT_GR10(\regs),%r10
1782	LDREG   PT_GR11(\regs),%r11
1783	LDREG   PT_GR12(\regs),%r12
1784	LDREG   PT_GR13(\regs),%r13
1785	LDREG   PT_GR14(\regs),%r14
1786	LDREG   PT_GR15(\regs),%r15
1787	LDREG   PT_GR16(\regs),%r16
1788	LDREG   PT_GR17(\regs),%r17
1789	LDREG   PT_GR18(\regs),%r18
1790	.endm
1791
1792ENTRY(sys_fork_wrapper)
1793	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30), %r1
1794	ldo	TASK_REGS(%r1),%r1
1795	reg_save %r1
1796	mfctl	%cr27, %r3
1797	STREG	%r3, PT_CR27(%r1)
1798
1799	STREG	%r2,-RP_OFFSET(%r30)
1800	ldo	FRAME_SIZE(%r30),%r30
1801#ifdef CONFIG_64BIT
1802	ldo	-16(%r30),%r29		/* Reference param save area */
1803#endif
1804
1805	/* These are call-clobbered registers and therefore
1806	   also syscall-clobbered (we hope). */
1807	STREG	%r2,PT_GR19(%r1)	/* save for child */
1808	STREG	%r30,PT_GR21(%r1)
1809
1810	LDREG	PT_GR30(%r1),%r25
1811	copy	%r1,%r24
1812	BL	sys_clone,%r2
1813	ldi	SIGCHLD,%r26
1814
1815	LDREG	-RP_OFFSET-FRAME_SIZE(%r30),%r2
1816wrapper_exit:
1817	ldo	-FRAME_SIZE(%r30),%r30		/* get the stackframe */
1818	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1819	ldo	TASK_REGS(%r1),%r1	 /* get pt regs */
1820
1821	LDREG	PT_CR27(%r1), %r3
1822	mtctl	%r3, %cr27
1823	reg_restore %r1
1824
1825	/* strace expects syscall # to be preserved in r20 */
1826	ldi	__NR_fork,%r20
1827	bv %r0(%r2)
1828	STREG	%r20,PT_GR20(%r1)
1829ENDPROC(sys_fork_wrapper)
1830
1831	/* Set the return value for the child */
1832ENTRY(child_return)
1833	BL	schedule_tail, %r2
1834	nop
1835
1836	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE-FRAME_SIZE(%r30), %r1
1837	LDREG	TASK_PT_GR19(%r1),%r2
1838	b	wrapper_exit
1839	copy	%r0,%r28
1840ENDPROC(child_return)
1841
1842
1843ENTRY(sys_clone_wrapper)
1844	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1845	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
1846	reg_save %r1
1847	mfctl	%cr27, %r3
1848	STREG	%r3, PT_CR27(%r1)
1849
1850	STREG	%r2,-RP_OFFSET(%r30)
1851	ldo	FRAME_SIZE(%r30),%r30
1852#ifdef CONFIG_64BIT
1853	ldo	-16(%r30),%r29		/* Reference param save area */
1854#endif
1855
1856	/* WARNING - Clobbers r19 and r21, userspace must save these! */
1857	STREG	%r2,PT_GR19(%r1)	/* save for child */
1858	STREG	%r30,PT_GR21(%r1)
1859	BL	sys_clone,%r2
1860	copy	%r1,%r24
1861
1862	b	wrapper_exit
1863	LDREG	-RP_OFFSET-FRAME_SIZE(%r30),%r2
1864ENDPROC(sys_clone_wrapper)
1865
1866
1867ENTRY(sys_vfork_wrapper)
1868	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1869	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
1870	reg_save %r1
1871	mfctl	%cr27, %r3
1872	STREG	%r3, PT_CR27(%r1)
1873
1874	STREG	%r2,-RP_OFFSET(%r30)
1875	ldo	FRAME_SIZE(%r30),%r30
1876#ifdef CONFIG_64BIT
1877	ldo	-16(%r30),%r29		/* Reference param save area */
1878#endif
1879
1880	STREG	%r2,PT_GR19(%r1)	/* save for child */
1881	STREG	%r30,PT_GR21(%r1)
1882
1883	BL	sys_vfork,%r2
1884	copy	%r1,%r26
1885
1886	b	wrapper_exit
1887	LDREG	-RP_OFFSET-FRAME_SIZE(%r30),%r2
1888ENDPROC(sys_vfork_wrapper)
1889
1890
1891	.macro  execve_wrapper execve
1892	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1893	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
1894
1895	/*
1896	 * Do we need to save/restore r3-r18 here?
1897	 * I don't think so. why would new thread need old
1898	 * threads registers?
1899	 */
1900
1901	/* %arg0 - %arg3 are already saved for us. */
1902
1903	STREG %r2,-RP_OFFSET(%r30)
1904	ldo FRAME_SIZE(%r30),%r30
1905#ifdef CONFIG_64BIT
1906	ldo	-16(%r30),%r29		/* Reference param save area */
1907#endif
1908	BL \execve,%r2
1909	copy %r1,%arg0
1910
1911	ldo -FRAME_SIZE(%r30),%r30
1912	LDREG -RP_OFFSET(%r30),%r2
1913
1914	/* If exec succeeded we need to load the args */
1915
1916	ldo -1024(%r0),%r1
1917	cmpb,>>= %r28,%r1,error_\execve
1918	copy %r2,%r19
1919
1920error_\execve:
1921	bv %r0(%r19)
1922	nop
1923	.endm
1924
1925	.import sys_execve
1926ENTRY(sys_execve_wrapper)
1927	execve_wrapper sys_execve
1928ENDPROC(sys_execve_wrapper)
1929
1930#ifdef CONFIG_64BIT
1931	.import sys32_execve
1932ENTRY(sys32_execve_wrapper)
1933	execve_wrapper sys32_execve
1934ENDPROC(sys32_execve_wrapper)
1935#endif
1936
1937ENTRY(sys_rt_sigreturn_wrapper)
1938	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r26
1939	ldo	TASK_REGS(%r26),%r26	/* get pt regs */
1940	/* Don't save regs, we are going to restore them from sigcontext. */
1941	STREG	%r2, -RP_OFFSET(%r30)
1942#ifdef CONFIG_64BIT
1943	ldo	FRAME_SIZE(%r30), %r30
1944	BL	sys_rt_sigreturn,%r2
1945	ldo	-16(%r30),%r29		/* Reference param save area */
1946#else
1947	BL	sys_rt_sigreturn,%r2
1948	ldo	FRAME_SIZE(%r30), %r30
1949#endif
1950
1951	ldo	-FRAME_SIZE(%r30), %r30
1952	LDREG	-RP_OFFSET(%r30), %r2
1953
1954	/* FIXME: I think we need to restore a few more things here. */
1955	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1956	ldo	TASK_REGS(%r1),%r1	/* get pt regs */
1957	reg_restore %r1
1958
1959	/* If the signal was received while the process was blocked on a
1960	 * syscall, then r2 will take us to syscall_exit; otherwise r2 will
1961	 * take us to syscall_exit_rfi and on to intr_return.
1962	 */
1963	bv	%r0(%r2)
1964	LDREG	PT_GR28(%r1),%r28  /* reload original r28 for syscall_exit */
1965ENDPROC(sys_rt_sigreturn_wrapper)
1966
1967ENTRY(sys_sigaltstack_wrapper)
1968	/* Get the user stack pointer */
1969	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
1970	ldo	TASK_REGS(%r1),%r24	/* get pt regs */
1971	LDREG	TASK_PT_GR30(%r24),%r24
1972	STREG	%r2, -RP_OFFSET(%r30)
1973#ifdef CONFIG_64BIT
1974	ldo	FRAME_SIZE(%r30), %r30
1975	BL	do_sigaltstack,%r2
1976	ldo	-16(%r30),%r29		/* Reference param save area */
1977#else
1978	BL	do_sigaltstack,%r2
1979	ldo	FRAME_SIZE(%r30), %r30
1980#endif
1981
1982	ldo	-FRAME_SIZE(%r30), %r30
1983	LDREG	-RP_OFFSET(%r30), %r2
1984	bv	%r0(%r2)
1985	nop
1986ENDPROC(sys_sigaltstack_wrapper)
1987
1988#ifdef CONFIG_64BIT
1989ENTRY(sys32_sigaltstack_wrapper)
1990	/* Get the user stack pointer */
1991	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r24
1992	LDREG	TASK_PT_GR30(%r24),%r24
1993	STREG	%r2, -RP_OFFSET(%r30)
1994	ldo	FRAME_SIZE(%r30), %r30
1995	BL	do_sigaltstack32,%r2
1996	ldo	-16(%r30),%r29		/* Reference param save area */
1997
1998	ldo	-FRAME_SIZE(%r30), %r30
1999	LDREG	-RP_OFFSET(%r30), %r2
2000	bv	%r0(%r2)
2001	nop
2002ENDPROC(sys32_sigaltstack_wrapper)
2003#endif
2004
2005ENTRY(syscall_exit)
2006	/* NOTE: HP-UX syscalls also come through here
2007	 * after hpux_syscall_exit fixes up return
2008	 * values. */
2009
2010	/* NOTE: Not all syscalls exit this way.  rt_sigreturn will exit
2011	 * via syscall_exit_rfi if the signal was received while the process
2012	 * was running.
2013	 */
2014
2015	/* save return value now */
2016
2017	mfctl     %cr30, %r1
2018	LDREG     TI_TASK(%r1),%r1
2019	STREG     %r28,TASK_PT_GR28(%r1)
2020
2021#ifdef CONFIG_HPUX
2022/* <linux/personality.h> cannot be easily included */
2023#define PER_HPUX 0x10
2024	ldw	TASK_PERSONALITY(%r1),%r19
2025
2026	/* We can't use "CMPIB<> PER_HPUX" since "im5" field is sign extended */
2027	ldo	  -PER_HPUX(%r19), %r19
2028	CMPIB<>,n 0,%r19,1f
2029
2030	/* Save other hpux returns if personality is PER_HPUX */
2031	STREG     %r22,TASK_PT_GR22(%r1)
2032	STREG     %r29,TASK_PT_GR29(%r1)
20331:
2034
2035#endif /* CONFIG_HPUX */
2036
2037	/* Seems to me that dp could be wrong here, if the syscall involved
2038	 * calling a module, and nothing got round to restoring dp on return.
2039	 */
2040	loadgp
2041
2042syscall_check_resched:
2043
2044	/* check for reschedule */
2045
2046	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19	/* long */
2047	bb,<,n	%r19, 31-TIF_NEED_RESCHED, syscall_do_resched /* forward */
2048
2049	.import do_signal,code
2050syscall_check_sig:
2051	LDREG	TI_FLAGS-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r19
2052	ldi	(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK), %r26
2053	and,COND(<>)	%r19, %r26, %r0
2054	b,n	syscall_restore	/* skip past if we've nothing to do */
2055
2056syscall_do_signal:
2057	/* Save callee-save registers (for sigcontext).
2058	 * FIXME: After this point the process structure should be
2059	 * consistent with all the relevant state of the process
2060	 * before the syscall.  We need to verify this.
2061	 */
2062	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
2063	ldo	TASK_REGS(%r1), %r26		/* struct pt_regs *regs */
2064	reg_save %r26
2065
2066#ifdef CONFIG_64BIT
2067	ldo	-16(%r30),%r29			/* Reference param save area */
2068#endif
2069
2070	BL	do_notify_resume,%r2
2071	ldi	1, %r25				/* long in_syscall = 1 */
2072
2073	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
2074	ldo	TASK_REGS(%r1), %r20		/* reload pt_regs */
2075	reg_restore %r20
2076
2077	b,n     syscall_check_sig
2078
2079syscall_restore:
2080	/* Are we being ptraced? */
2081	LDREG	TI_TASK-THREAD_SZ_ALGN-FRAME_SIZE(%r30),%r1
2082
2083	ldw	TASK_PTRACE(%r1), %r19
2084	bb,<	%r19,31,syscall_restore_rfi
2085	nop
2086
2087	ldo	TASK_PT_FR31(%r1),%r19		   /* reload fpregs */
2088	rest_fp	%r19
2089
2090	LDREG	TASK_PT_SAR(%r1),%r19		   /* restore SAR */
2091	mtsar	%r19
2092
2093	LDREG	TASK_PT_GR2(%r1),%r2		   /* restore user rp */
2094	LDREG	TASK_PT_GR19(%r1),%r19
2095	LDREG   TASK_PT_GR20(%r1),%r20
2096	LDREG	TASK_PT_GR21(%r1),%r21
2097	LDREG	TASK_PT_GR22(%r1),%r22
2098	LDREG	TASK_PT_GR23(%r1),%r23
2099	LDREG	TASK_PT_GR24(%r1),%r24
2100	LDREG	TASK_PT_GR25(%r1),%r25
2101	LDREG	TASK_PT_GR26(%r1),%r26
2102	LDREG	TASK_PT_GR27(%r1),%r27	   /* restore user dp */
2103	LDREG	TASK_PT_GR28(%r1),%r28	   /* syscall return value */
2104	LDREG	TASK_PT_GR29(%r1),%r29
2105	LDREG	TASK_PT_GR31(%r1),%r31	   /* restore syscall rp */
2106
2107	/* NOTE: We use rsm/ssm pair to make this operation atomic */
2108	rsm     PSW_SM_I, %r0
2109	LDREG   TASK_PT_GR30(%r1),%r30             /* restore user sp */
2110	mfsp	%sr3,%r1			   /* Get users space id */
2111	mtsp    %r1,%sr7                           /* Restore sr7 */
2112	ssm     PSW_SM_I, %r0
2113
2114	/* Set sr2 to zero for userspace syscalls to work. */
2115	mtsp	%r0,%sr2
2116	mtsp	%r1,%sr4			   /* Restore sr4 */
2117	mtsp	%r1,%sr5			   /* Restore sr5 */
2118	mtsp	%r1,%sr6			   /* Restore sr6 */
2119
2120	depi	3,31,2,%r31			   /* ensure return to user mode. */
2121
2122#ifdef CONFIG_64BIT
2123	/* decide whether to reset the wide mode bit
2124	 *
2125	 * For a syscall, the W bit is stored in the lowest bit
2126	 * of sp.  Extract it and reset W if it is zero */
2127	extrd,u,*<>	%r30,63,1,%r1
2128	rsm	PSW_SM_W, %r0
2129	/* now reset the lowest bit of sp if it was set */
2130	xor	%r30,%r1,%r30
2131#endif
2132	be,n    0(%sr3,%r31)                       /* return to user space */
2133
2134	/* We have to return via an RFI, so that PSW T and R bits can be set
2135	 * appropriately.
2136	 * This sets up pt_regs so we can return via intr_restore, which is not
2137	 * the most efficient way of doing things, but it works.
2138	 */
2139syscall_restore_rfi:
2140	ldo	-1(%r0),%r2			   /* Set recovery cntr to -1 */
2141	mtctl	%r2,%cr0			   /*   for immediate trap */
2142	LDREG	TASK_PT_PSW(%r1),%r2		   /* Get old PSW */
2143	ldi	0x0b,%r20			   /* Create new PSW */
2144	depi	-1,13,1,%r20			   /* C, Q, D, and I bits */
2145
2146	/* The values of PA_SINGLESTEP_BIT and PA_BLOCKSTEP_BIT are
2147	 * set in include/linux/ptrace.h and converted to PA bitmap
2148	 * numbers in asm-offsets.c */
2149
2150	/* if ((%r19.PA_SINGLESTEP_BIT)) { %r20.27=1} */
2151	extru,=	%r19,PA_SINGLESTEP_BIT,1,%r0
2152	depi	-1,27,1,%r20			   /* R bit */
2153
2154	/* if ((%r19.PA_BLOCKSTEP_BIT)) { %r20.7=1} */
2155	extru,= %r19,PA_BLOCKSTEP_BIT,1,%r0
2156	depi	-1,7,1,%r20			   /* T bit */
2157
2158	STREG	%r20,TASK_PT_PSW(%r1)
2159
2160	/* Always store space registers, since sr3 can be changed (e.g. fork) */
2161
2162	mfsp    %sr3,%r25
2163	STREG   %r25,TASK_PT_SR3(%r1)
2164	STREG   %r25,TASK_PT_SR4(%r1)
2165	STREG   %r25,TASK_PT_SR5(%r1)
2166	STREG   %r25,TASK_PT_SR6(%r1)
2167	STREG   %r25,TASK_PT_SR7(%r1)
2168	STREG   %r25,TASK_PT_IASQ0(%r1)
2169	STREG   %r25,TASK_PT_IASQ1(%r1)
2170
2171	/* XXX W bit??? */
2172	/* Now if old D bit is clear, it means we didn't save all registers
2173	 * on syscall entry, so do that now.  This only happens on TRACEME
2174	 * calls, or if someone attached to us while we were on a syscall.
2175	 * We could make this more efficient by not saving r3-r18, but
2176	 * then we wouldn't be able to use the common intr_restore path.
2177	 * It is only for traced processes anyway, so performance is not
2178	 * an issue.
2179	 */
2180	bb,<	%r2,30,pt_regs_ok		   /* Branch if D set */
2181	ldo	TASK_REGS(%r1),%r25
2182	reg_save %r25				   /* Save r3 to r18 */
2183
2184	/* Save the current sr */
2185	mfsp	%sr0,%r2
2186	STREG	%r2,TASK_PT_SR0(%r1)
2187
2188	/* Save the scratch sr */
2189	mfsp	%sr1,%r2
2190	STREG	%r2,TASK_PT_SR1(%r1)
2191
2192	/* sr2 should be set to zero for userspace syscalls */
2193	STREG	%r0,TASK_PT_SR2(%r1)
2194
2195pt_regs_ok:
2196	LDREG	TASK_PT_GR31(%r1),%r2
2197	depi	3,31,2,%r2			   /* ensure return to user mode. */
2198	STREG	%r2,TASK_PT_IAOQ0(%r1)
2199	ldo	4(%r2),%r2
2200	STREG	%r2,TASK_PT_IAOQ1(%r1)
2201	copy	%r25,%r16
2202	b	intr_restore
2203	nop
2204
2205	.import schedule,code
2206syscall_do_resched:
2207	BL	schedule,%r2
2208#ifdef CONFIG_64BIT
2209	ldo	-16(%r30),%r29		/* Reference param save area */
2210#else
2211	nop
2212#endif
2213	b	syscall_check_resched	/* if resched, we start over again */
2214	nop
2215ENDPROC(syscall_exit)
2216
2217
2218get_register:
2219	/*
2220	 * get_register is used by the non access tlb miss handlers to
2221	 * copy the value of the general register specified in r8 into
2222	 * r1. This routine can't be used for shadowed registers, since
2223	 * the rfir will restore the original value. So, for the shadowed
2224	 * registers we put a -1 into r1 to indicate that the register
2225	 * should not be used (the register being copied could also have
2226	 * a -1 in it, but that is OK, it just means that we will have
2227	 * to use the slow path instead).
2228	 */
2229	blr     %r8,%r0
2230	nop
2231	bv      %r0(%r25)    /* r0 */
2232	copy    %r0,%r1
2233	bv      %r0(%r25)    /* r1 - shadowed */
2234	ldi     -1,%r1
2235	bv      %r0(%r25)    /* r2 */
2236	copy    %r2,%r1
2237	bv      %r0(%r25)    /* r3 */
2238	copy    %r3,%r1
2239	bv      %r0(%r25)    /* r4 */
2240	copy    %r4,%r1
2241	bv      %r0(%r25)    /* r5 */
2242	copy    %r5,%r1
2243	bv      %r0(%r25)    /* r6 */
2244	copy    %r6,%r1
2245	bv      %r0(%r25)    /* r7 */
2246	copy    %r7,%r1
2247	bv      %r0(%r25)    /* r8 - shadowed */
2248	ldi     -1,%r1
2249	bv      %r0(%r25)    /* r9 - shadowed */
2250	ldi     -1,%r1
2251	bv      %r0(%r25)    /* r10 */
2252	copy    %r10,%r1
2253	bv      %r0(%r25)    /* r11 */
2254	copy    %r11,%r1
2255	bv      %r0(%r25)    /* r12 */
2256	copy    %r12,%r1
2257	bv      %r0(%r25)    /* r13 */
2258	copy    %r13,%r1
2259	bv      %r0(%r25)    /* r14 */
2260	copy    %r14,%r1
2261	bv      %r0(%r25)    /* r15 */
2262	copy    %r15,%r1
2263	bv      %r0(%r25)    /* r16 - shadowed */
2264	ldi     -1,%r1
2265	bv      %r0(%r25)    /* r17 - shadowed */
2266	ldi     -1,%r1
2267	bv      %r0(%r25)    /* r18 */
2268	copy    %r18,%r1
2269	bv      %r0(%r25)    /* r19 */
2270	copy    %r19,%r1
2271	bv      %r0(%r25)    /* r20 */
2272	copy    %r20,%r1
2273	bv      %r0(%r25)    /* r21 */
2274	copy    %r21,%r1
2275	bv      %r0(%r25)    /* r22 */
2276	copy    %r22,%r1
2277	bv      %r0(%r25)    /* r23 */
2278	copy    %r23,%r1
2279	bv      %r0(%r25)    /* r24 - shadowed */
2280	ldi     -1,%r1
2281	bv      %r0(%r25)    /* r25 - shadowed */
2282	ldi     -1,%r1
2283	bv      %r0(%r25)    /* r26 */
2284	copy    %r26,%r1
2285	bv      %r0(%r25)    /* r27 */
2286	copy    %r27,%r1
2287	bv      %r0(%r25)    /* r28 */
2288	copy    %r28,%r1
2289	bv      %r0(%r25)    /* r29 */
2290	copy    %r29,%r1
2291	bv      %r0(%r25)    /* r30 */
2292	copy    %r30,%r1
2293	bv      %r0(%r25)    /* r31 */
2294	copy    %r31,%r1
2295
2296
2297set_register:
2298	/*
2299	 * set_register is used by the non access tlb miss handlers to
2300	 * copy the value of r1 into the general register specified in
2301	 * r8.
2302	 */
2303	blr     %r8,%r0
2304	nop
2305	bv      %r0(%r25)    /* r0 (silly, but it is a place holder) */
2306	copy    %r1,%r0
2307	bv      %r0(%r25)    /* r1 */
2308	copy    %r1,%r1
2309	bv      %r0(%r25)    /* r2 */
2310	copy    %r1,%r2
2311	bv      %r0(%r25)    /* r3 */
2312	copy    %r1,%r3
2313	bv      %r0(%r25)    /* r4 */
2314	copy    %r1,%r4
2315	bv      %r0(%r25)    /* r5 */
2316	copy    %r1,%r5
2317	bv      %r0(%r25)    /* r6 */
2318	copy    %r1,%r6
2319	bv      %r0(%r25)    /* r7 */
2320	copy    %r1,%r7
2321	bv      %r0(%r25)    /* r8 */
2322	copy    %r1,%r8
2323	bv      %r0(%r25)    /* r9 */
2324	copy    %r1,%r9
2325	bv      %r0(%r25)    /* r10 */
2326	copy    %r1,%r10
2327	bv      %r0(%r25)    /* r11 */
2328	copy    %r1,%r11
2329	bv      %r0(%r25)    /* r12 */
2330	copy    %r1,%r12
2331	bv      %r0(%r25)    /* r13 */
2332	copy    %r1,%r13
2333	bv      %r0(%r25)    /* r14 */
2334	copy    %r1,%r14
2335	bv      %r0(%r25)    /* r15 */
2336	copy    %r1,%r15
2337	bv      %r0(%r25)    /* r16 */
2338	copy    %r1,%r16
2339	bv      %r0(%r25)    /* r17 */
2340	copy    %r1,%r17
2341	bv      %r0(%r25)    /* r18 */
2342	copy    %r1,%r18
2343	bv      %r0(%r25)    /* r19 */
2344	copy    %r1,%r19
2345	bv      %r0(%r25)    /* r20 */
2346	copy    %r1,%r20
2347	bv      %r0(%r25)    /* r21 */
2348	copy    %r1,%r21
2349	bv      %r0(%r25)    /* r22 */
2350	copy    %r1,%r22
2351	bv      %r0(%r25)    /* r23 */
2352	copy    %r1,%r23
2353	bv      %r0(%r25)    /* r24 */
2354	copy    %r1,%r24
2355	bv      %r0(%r25)    /* r25 */
2356	copy    %r1,%r25
2357	bv      %r0(%r25)    /* r26 */
2358	copy    %r1,%r26
2359	bv      %r0(%r25)    /* r27 */
2360	copy    %r1,%r27
2361	bv      %r0(%r25)    /* r28 */
2362	copy    %r1,%r28
2363	bv      %r0(%r25)    /* r29 */
2364	copy    %r1,%r29
2365	bv      %r0(%r25)    /* r30 */
2366	copy    %r1,%r30
2367	bv      %r0(%r25)    /* r31 */
2368	copy    %r1,%r31
2369
2370