aboutsummaryrefslogtreecommitdiffstats
path: root/arch/sparc64/kernel/rtrap.S
blob: e6130956307f88c873ce3e22ad28778184817825 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
/* $Id: rtrap.S,v 1.61 2002/02/09 19:49:31 davem Exp $
 * rtrap.S: Preparing for return from trap on Sparc V9.
 *
 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
 */

#include <linux/config.h>

#include <asm/asi.h>
#include <asm/pstate.h>
#include <asm/ptrace.h>
#include <asm/spitfire.h>
#include <asm/head.h>
#include <asm/visasm.h>
#include <asm/processor.h>

#define		RTRAP_PSTATE		(PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_IE)
#define		RTRAP_PSTATE_IRQOFF	(PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV)
#define		RTRAP_PSTATE_AG_IRQOFF	(PSTATE_RMO|PSTATE_PEF|PSTATE_PRIV|PSTATE_AG)

		/* Register %l6 keeps track of whether we are returning
		 * from a system call or not.  It is cleared if we call
		 * do_notify_resume, and it must not be otherwise modified
		 * until we fully commit to returning to userspace.
		 */

		.text
		.align			32
__handle_softirq:
		call			do_softirq
		 nop
		ba,a,pt			%xcc, __handle_softirq_continue
		 nop
__handle_preemption:
		call			schedule
		 wrpr			%g0, RTRAP_PSTATE, %pstate
		ba,pt			%xcc, __handle_preemption_continue
		 wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate

__handle_user_windows:
		call			fault_in_user_windows
		 wrpr			%g0, RTRAP_PSTATE, %pstate
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		/* Redo sched+sig checks */
		ldx			[%g6 + TI_FLAGS], %l0
		andcc			%l0, _TIF_NEED_RESCHED, %g0

		be,pt			%xcc, 1f
		 nop
		call			schedule
		 wrpr			%g0, RTRAP_PSTATE, %pstate
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		ldx			[%g6 + TI_FLAGS], %l0

1:		andcc			%l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0
		be,pt			%xcc, __handle_user_windows_continue
		 nop
		mov			%l5, %o1
		mov			%l6, %o2
		add			%sp, PTREGS_OFF, %o0
		mov			%l0, %o3

		call			do_notify_resume
		 wrpr			%g0, RTRAP_PSTATE, %pstate
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		clr			%l6
		/* Signal delivery can modify pt_regs tstate, so we must
		 * reload it.
		 */
		ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
		sethi			%hi(0xf << 20), %l4
		and			%l1, %l4, %l4
		ba,pt			%xcc, __handle_user_windows_continue

		 andn			%l1, %l4, %l1
__handle_perfctrs:
		call			update_perfctrs
		 wrpr			%g0, RTRAP_PSTATE, %pstate
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		ldub			[%g6 + TI_WSAVED], %o2
		brz,pt			%o2, 1f
		 nop
		/* Redo userwin+sched+sig checks */
		call			fault_in_user_windows

		 wrpr			%g0, RTRAP_PSTATE, %pstate
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		ldx			[%g6 + TI_FLAGS], %l0
		andcc			%l0, _TIF_NEED_RESCHED, %g0
		be,pt			%xcc, 1f

		 nop
		call			schedule
		 wrpr			%g0, RTRAP_PSTATE, %pstate
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		ldx			[%g6 + TI_FLAGS], %l0
1:		andcc			%l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0

		be,pt			%xcc, __handle_perfctrs_continue
		 sethi			%hi(TSTATE_PEF), %o0
		mov			%l5, %o1
		mov			%l6, %o2
		add			%sp, PTREGS_OFF, %o0
		mov			%l0, %o3
		call			do_notify_resume

		 wrpr			%g0, RTRAP_PSTATE, %pstate
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		clr			%l6
		/* Signal delivery can modify pt_regs tstate, so we must
		 * reload it.
		 */
		ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
		sethi			%hi(0xf << 20), %l4
		and			%l1, %l4, %l4
		andn			%l1, %l4, %l1
		ba,pt			%xcc, __handle_perfctrs_continue

		 sethi			%hi(TSTATE_PEF), %o0
__handle_userfpu:
		rd			%fprs, %l5
		andcc			%l5, FPRS_FEF, %g0
		sethi			%hi(TSTATE_PEF), %o0
		be,a,pn			%icc, __handle_userfpu_continue
		 andn			%l1, %o0, %l1
		ba,a,pt			%xcc, __handle_userfpu_continue

__handle_signal:
		mov			%l5, %o1
		mov			%l6, %o2
		add			%sp, PTREGS_OFF, %o0
		mov			%l0, %o3
		call			do_notify_resume
		 wrpr			%g0, RTRAP_PSTATE, %pstate
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		clr			%l6

		/* Signal delivery can modify pt_regs tstate, so we must
		 * reload it.
		 */
		ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
		sethi			%hi(0xf << 20), %l4
		and			%l1, %l4, %l4
		ba,pt			%xcc, __handle_signal_continue
		 andn			%l1, %l4, %l1

		.align			64
		.globl			rtrap_irq, rtrap_clr_l6, rtrap, irqsz_patchme, rtrap_xcall
rtrap_irq:
rtrap_clr_l6:	clr			%l6
rtrap:
#ifndef CONFIG_SMP
		sethi			%hi(per_cpu____cpu_data), %l0
		lduw			[%l0 + %lo(per_cpu____cpu_data)], %l1
#else
		sethi			%hi(per_cpu____cpu_data), %l0
		or			%l0, %lo(per_cpu____cpu_data), %l0
		lduw			[%l0 + %g5], %l1
#endif
		cmp			%l1, 0

		/* mm/ultra.S:xcall_report_regs KNOWS about this load. */
		bne,pn			%icc, __handle_softirq
		 ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
__handle_softirq_continue:
rtrap_xcall:
		sethi			%hi(0xf << 20), %l4
		andcc			%l1, TSTATE_PRIV, %l3
		and			%l1, %l4, %l4
		bne,pn			%icc, to_kernel
		 andn			%l1, %l4, %l1

		/* We must hold IRQs off and atomically test schedule+signal
		 * state, then hold them off all the way back to userspace.
		 * If we are returning to kernel, none of this matters.
		 *
		 * If we do not do this, there is a window where we would do
		 * the tests, later the signal/resched event arrives but we do
		 * not process it since we are still in kernel mode.  It would
		 * take until the next local IRQ before the signal/resched
		 * event would be handled.
		 *
		 * This also means that if we have to deal with performance
		 * counters or user windows, we have to redo all of these
		 * sched+signal checks with IRQs disabled.
		 */
to_user:	wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		wrpr			0, %pil
__handle_preemption_continue:
		ldx			[%g6 + TI_FLAGS], %l0
		sethi			%hi(_TIF_USER_WORK_MASK), %o0
		or			%o0, %lo(_TIF_USER_WORK_MASK), %o0
		andcc			%l0, %o0, %g0
		sethi			%hi(TSTATE_PEF), %o0
		be,pt			%xcc, user_nowork
		 andcc			%l1, %o0, %g0
		andcc			%l0, _TIF_NEED_RESCHED, %g0
		bne,pn			%xcc, __handle_preemption
		 andcc			%l0, (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK), %g0
		bne,pn			%xcc, __handle_signal
__handle_signal_continue:
		 ldub			[%g6 + TI_WSAVED], %o2
		brnz,pn			%o2, __handle_user_windows
		 nop
__handle_user_windows_continue:
		ldx			[%g6 + TI_FLAGS], %l5
		andcc			%l5, _TIF_PERFCTR, %g0
		sethi			%hi(TSTATE_PEF), %o0
		bne,pn			%xcc, __handle_perfctrs
__handle_perfctrs_continue:
		 andcc			%l1, %o0, %g0

		/* This fpdepth clear is necessary for non-syscall rtraps only */
user_nowork:
		bne,pn			%xcc, __handle_userfpu
		 stb			%g0, [%g6 + TI_FPDEPTH]
__handle_userfpu_continue:

rt_continue:	ldx			[%sp + PTREGS_OFF + PT_V9_G1], %g1
		ldx			[%sp + PTREGS_OFF + PT_V9_G2], %g2

		ldx			[%sp + PTREGS_OFF + PT_V9_G3], %g3
		ldx			[%sp + PTREGS_OFF + PT_V9_G4], %g4
		ldx			[%sp + PTREGS_OFF + PT_V9_G5], %g5
		brz,pt			%l3, 1f
		 nop
		/* Must do this before thread reg is clobbered below.  */
		LOAD_PER_CPU_BASE(%g5, %g6, %i0, %i1, %i2)
1:
		ldx			[%sp + PTREGS_OFF + PT_V9_G6], %g6
		ldx			[%sp + PTREGS_OFF + PT_V9_G7], %g7

		/* Normal globals are restored, go to trap globals.  */
661:		wrpr			%g0, RTRAP_PSTATE_AG_IRQOFF, %pstate
		.section		.gl_1insn_patch, "ax"
		.word			661b
		SET_GL(1)
		.previous

		ldx			[%sp + PTREGS_OFF + PT_V9_I0], %i0
		ldx			[%sp + PTREGS_OFF + PT_V9_I1], %i1

		ldx			[%sp + PTREGS_OFF + PT_V9_I2], %i2
		ldx			[%sp + PTREGS_OFF + PT_V9_I3], %i3
		ldx			[%sp + PTREGS_OFF + PT_V9_I4], %i4
		ldx			[%sp + PTREGS_OFF + PT_V9_I5], %i5
		ldx			[%sp + PTREGS_OFF + PT_V9_I6], %i6
		ldx			[%sp + PTREGS_OFF + PT_V9_I7], %i7
		ldx			[%sp + PTREGS_OFF + PT_V9_TPC], %l2
		ldx			[%sp + PTREGS_OFF + PT_V9_TNPC], %o2

		ld			[%sp + PTREGS_OFF + PT_V9_Y], %o3
		wr			%o3, %g0, %y
		srl			%l4, 20, %l4
		wrpr			%l4, 0x0, %pil
		wrpr			%g0, 0x1, %tl
		wrpr			%l1, %g0, %tstate
		wrpr			%l2, %g0, %tpc
		wrpr			%o2, %g0, %tnpc

		brnz,pn			%l3, kern_rtt
		 mov			PRIMARY_CONTEXT, %l7
		ldxa			[%l7 + %l7] ASI_DMMU, %l0
		sethi			%hi(sparc64_kern_pri_nuc_bits), %l1
		ldx			[%l1 + %lo(sparc64_kern_pri_nuc_bits)], %l1
		or			%l0, %l1, %l0
		stxa			%l0, [%l7] ASI_DMMU
		sethi			%hi(KERNBASE), %l7
		flush			%l7
		rdpr			%wstate, %l1
		rdpr			%otherwin, %l2
		srl			%l1, 3, %l1

		wrpr			%l2, %g0, %canrestore
		wrpr			%l1, %g0, %wstate
		brnz,pt			%l2, user_rtt_restore
		 wrpr			%g0, %g0, %otherwin

		ldx			[%g6 + TI_FLAGS], %g3
		wr			%g0, ASI_AIUP, %asi
		rdpr			%cwp, %g1
		andcc			%g3, _TIF_32BIT, %g0
		sub			%g1, 1, %g1
		bne,pt			%xcc, user_rtt_fill_32bit
		 wrpr			%g1, %cwp
		ba,a,pt			%xcc, user_rtt_fill_64bit

user_rtt_fill_fixup:
		rdpr	%cwp, %g1
		add	%g1, 1, %g1
		wrpr	%g1, 0x0, %cwp

		rdpr	%wstate, %g2
		sll	%g2, 3, %g2
		wrpr	%g2, 0x0, %wstate

		/* We know %canrestore and %otherwin are both zero.  */

		sethi	%hi(sparc64_kern_pri_context), %g2
		ldx	[%g2 + %lo(sparc64_kern_pri_context)], %g2
		mov	PRIMARY_CONTEXT, %g1
		stxa	%g2, [%g1] ASI_DMMU
		sethi	%hi(KERNBASE), %g1
		flush	%g1

		or	%g4, FAULT_CODE_WINFIXUP, %g4
		stb	%g4, [%g6 + TI_FAULT_CODE]
		stx	%g5, [%g6 + TI_FAULT_ADDR]

		mov	%g6, %l1
		wrpr	%g0, 0x0, %tl
		wrpr	%g0, RTRAP_PSTATE, %pstate

661:		nop
		.section		.gl_1insn_patch, "ax"
		.word			661b
		SET_GL(0)
		.previous

		mov	%l1, %g6
		ldx	[%g6 + TI_TASK], %g4
		LOAD_PER_CPU_BASE(%g5, %g6, %g1, %g2, %g3)
		call	do_sparc64_fault
		 add	%sp, PTREGS_OFF, %o0
		ba,pt	%xcc, rtrap
		 nop

user_rtt_pre_restore:
		add			%g1, 1, %g1
		wrpr			%g1, 0x0, %cwp

user_rtt_restore:
		restore
		rdpr			%canrestore, %g1
		wrpr			%g1, 0x0, %cleanwin
		retry
		nop

kern_rtt:	rdpr			%canrestore, %g1
		brz,pn			%g1, kern_rtt_fill
		 nop
kern_rtt_restore:
		restore
		retry

to_kernel:
#ifdef CONFIG_PREEMPT
		ldsw			[%g6 + TI_PRE_COUNT], %l5
		brnz			%l5, kern_fpucheck
		 ldx			[%g6 + TI_FLAGS], %l5
		andcc			%l5, _TIF_NEED_RESCHED, %g0
		be,pt			%xcc, kern_fpucheck
		 srl			%l4, 20, %l5
		cmp			%l5, 0
		bne,pn			%xcc, kern_fpucheck
		 sethi			%hi(PREEMPT_ACTIVE), %l6
		stw			%l6, [%g6 + TI_PRE_COUNT]
		call			schedule
		 nop
		ba,pt			%xcc, rtrap
		 stw			%g0, [%g6 + TI_PRE_COUNT]
#endif
kern_fpucheck:	ldub			[%g6 + TI_FPDEPTH], %l5
		brz,pt			%l5, rt_continue
		 srl			%l5, 1, %o0
		add			%g6, TI_FPSAVED, %l6
		ldub			[%l6 + %o0], %l2
		sub			%l5, 2, %l5

		add			%g6, TI_GSR, %o1
		andcc			%l2, (FPRS_FEF|FPRS_DU), %g0
		be,pt			%icc, 2f
		 and			%l2, FPRS_DL, %l6
		andcc			%l2, FPRS_FEF, %g0
		be,pn			%icc, 5f
		 sll			%o0, 3, %o5
		rd			%fprs, %g1

		wr			%g1, FPRS_FEF, %fprs
		ldx			[%o1 + %o5], %g1
		add			%g6, TI_XFSR, %o1
		sll			%o0, 8, %o2
		add			%g6, TI_FPREGS, %o3
		brz,pn			%l6, 1f
		 add			%g6, TI_FPREGS+0x40, %o4

		membar			#Sync
		ldda			[%o3 + %o2] ASI_BLK_P, %f0
		ldda			[%o4 + %o2] ASI_BLK_P, %f16
		membar			#Sync
1:		andcc			%l2, FPRS_DU, %g0
		be,pn			%icc, 1f
		 wr			%g1, 0, %gsr
		add			%o2, 0x80, %o2
		membar			#Sync
		ldda			[%o3 + %o2] ASI_BLK_P, %f32
		ldda			[%o4 + %o2] ASI_BLK_P, %f48
1:		membar			#Sync
		ldx			[%o1 + %o5], %fsr
2:		stb			%l5, [%g6 + TI_FPDEPTH]
		ba,pt			%xcc, rt_continue
		 nop
5:		wr			%g0, FPRS_FEF, %fprs
		sll			%o0, 8, %o2

		add			%g6, TI_FPREGS+0x80, %o3
		add			%g6, TI_FPREGS+0xc0, %o4
		membar			#Sync
		ldda			[%o3 + %o2] ASI_BLK_P, %f32
		ldda			[%o4 + %o2] ASI_BLK_P, %f48
		membar			#Sync
		wr			%g0, FPRS_DU, %fprs
		ba,pt			%xcc, rt_continue
		 stb			%l5, [%g6 + TI_FPDEPTH]