summaryrefslogtreecommitdiffstats
path: root/arch/sparc/kernel/rtrap_64.S
blob: 29aa34f11720cea3e098372995f751298b09e641 (plain)
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
/* SPDX-License-Identifier: GPL-2.0 */
/*
 * 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 <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>

#ifdef CONFIG_CONTEXT_TRACKING
# define SCHEDULE_USER schedule_user
#else
# define SCHEDULE_USER schedule
#endif

		.text
		.align			32
__handle_preemption:
		call			SCHEDULE_USER
661:		 wrpr			%g0, RTRAP_PSTATE, %pstate
		/* If userspace is using ADI, it could potentially pass
		 * a pointer with version tag embedded in it. To maintain
		 * the ADI security, we must re-enable PSTATE.mcde before
		 * we continue execution in the kernel for another thread.
		 */
		.section .sun_m7_1insn_patch, "ax"
		.word	661b
		 wrpr			%g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate
		.previous
		ba,pt			%xcc, __handle_preemption_continue
		 wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate

__handle_user_windows:
		add			%sp, PTREGS_OFF, %o0
		call			fault_in_user_windows
661:		 wrpr			%g0, RTRAP_PSTATE, %pstate
		/* If userspace is using ADI, it could potentially pass
		 * a pointer with version tag embedded in it. To maintain
		 * the ADI security, we must re-enable PSTATE.mcde before
		 * we continue execution in the kernel for another thread.
		 */
		.section .sun_m7_1insn_patch, "ax"
		.word	661b
		 wrpr			%g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate
		.previous
		ba,pt			%xcc, __handle_preemption_continue
		 wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate

__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
		add			%sp, PTREGS_OFF, %o0
		mov			%l0, %o2
		call			do_notify_resume
661:		 wrpr			%g0, RTRAP_PSTATE, %pstate
		/* If userspace is using ADI, it could potentially pass
		 * a pointer with version tag embedded in it. To maintain
		 * the ADI security, we must re-enable PSTATE.mcde before
		 * we continue execution in the kernel for another thread.
		 */
		.section .sun_m7_1insn_patch, "ax"
		.word	661b
		 wrpr			%g0, RTRAP_PSTATE|PSTATE_MCDE, %pstate
		.previous
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate

		/* 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_preemption_continue
		 srl			%l4, 20, %l4

		/* When returning from a NMI (%pil==15) interrupt we want to
		 * avoid running softirqs, doing IRQ tracing, preempting, etc.
		 */
		.globl			rtrap_nmi
rtrap_nmi:	ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
		sethi			%hi(0xf << 20), %l4
		and			%l1, %l4, %l4
		andn			%l1, %l4, %l1
		srl			%l4, 20, %l4
		ba,pt			%xcc, rtrap_no_irq_enable
		nop
		/* Do not actually set the %pil here.  We will do that
		 * below after we clear PSTATE_IE in the %pstate register.
		 * If we re-enable interrupts here, we can recurse down
		 * the hardirq stack potentially endlessly, causing a
		 * stack overflow.
		 */

		.align			64
		.globl			rtrap_irq, rtrap, irqsz_patchme, rtrap_xcall
rtrap_irq:
rtrap:
		/* mm/ultra.S:xcall_report_regs KNOWS about this load. */
		ldx			[%sp + PTREGS_OFF + PT_V9_TSTATE], %l1
rtrap_xcall:
		sethi			%hi(0xf << 20), %l4
		and			%l1, %l4, %l4
		andn			%l1, %l4, %l1
		srl			%l4, 20, %l4
#ifdef CONFIG_TRACE_IRQFLAGS
		brnz,pn			%l4, rtrap_no_irq_enable
		 nop
		call			trace_hardirqs_on
		 nop
		/* Do not actually set the %pil here.  We will do that
		 * below after we clear PSTATE_IE in the %pstate register.
		 * If we re-enable interrupts here, we can recurse down
		 * the hardirq stack potentially endlessly, causing a
		 * stack overflow.
		 *
		 * It is tempting to put this test and trace_hardirqs_on
		 * call at the 'rt_continue' label, but that will not work
		 * as that path hits unconditionally and we do not want to
		 * execute this in NMI return paths, for example.
		 */
#endif
rtrap_no_irq_enable:
		andcc			%l1, TSTATE_PRIV, %l3
		bne,pn			%icc, to_kernel
		 nop

		/* 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.  Note
		 * that we are disabling interrupts via PSTATE_IE, not using
		 * %pil.
		 *
		 * 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 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_DO_NOTIFY_RESUME_MASK, %g0
		bne,pn			%xcc, __handle_signal
		 ldub			[%g6 + TI_WSAVED], %o2
		brnz,pn			%o2, __handle_user_windows
		 nop
		sethi			%hi(TSTATE_PEF), %o0
		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
		mov			%g6, %l2

		/* 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
		nop
		.section		.sun4v_2insn_patch, "ax"
		.word			661b
		wrpr			%g0, RTRAP_PSTATE_IRQOFF, %pstate
		SET_GL(1)
		.previous

		mov			%l2, %g6

		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
		wrpr			%l4, 0x0, %pil
		wrpr			%g0, 0x1, %tl
		andn			%l1, TSTATE_SYSCALL, %l1
		wrpr			%l1, %g0, %tstate
		wrpr			%l2, %g0, %tpc
		wrpr			%o2, %g0, %tnpc

		brnz,pn			%l3, kern_rtt
		 mov			PRIMARY_CONTEXT, %l7

661:		ldxa			[%l7 + %l7] ASI_DMMU, %l0
		.section		.sun4v_1insn_patch, "ax"
		.word			661b
		ldxa			[%l7 + %l7] ASI_MMU, %l0
		.previous

		sethi			%hi(sparc64_kern_pri_nuc_bits), %l1
		ldx			[%l1 + %lo(sparc64_kern_pri_nuc_bits)], %l1
		or			%l0, %l1, %l0

661:		stxa			%l0, [%l7] ASI_DMMU
		.section		.sun4v_1insn_patch, "ax"
		.word			661b
		stxa			%l0, [%l7] ASI_MMU
		.previous

		sethi			%hi(KERNBASE), %l7
		flush			%l7
		rdpr			%wstate, %l1
		rdpr			%otherwin, %l2
		srl			%l1, 3, %l1

661:		wrpr			%l2, %g0, %canrestore
		.section		.fast_win_ctrl_1insn_patch, "ax"
		.word			661b
		.word			0x89880000	! normalw
		.previous

		wrpr			%l1, %g0, %wstate
		brnz,pt			%l2, user_rtt_restore
661:		 wrpr			%g0, %g0, %otherwin
		.section		.fast_win_ctrl_1insn_patch, "ax"
		.word			661b
		 nop
		.previous

		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
		 nop

user_rtt_fill_fixup_dax:
		ba,pt	%xcc, user_rtt_fill_fixup_common
		 mov	1, %g3

user_rtt_fill_fixup_mna:
		ba,pt	%xcc, user_rtt_fill_fixup_common
		 mov	2, %g3

user_rtt_fill_fixup:
		ba,pt	%xcc, user_rtt_fill_fixup_common
		 clr	%g3

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:
		stw			%g0, [%sp + PTREGS_OFF + PT_V9_MAGIC]
		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
		 nop
		cmp			%l4, 0
		bne,pn			%xcc, kern_fpucheck
		 nop
		call			preempt_schedule_irq
		 nop
		ba,pt			%xcc, rtrap
#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]