summaryrefslogtreecommitdiffstats
path: root/arch/mips/include/asm/stackframe.h
blob: a71da576883c8f4b1a3d60279ebfaefb95798031 (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
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
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1994, 95, 96, 99, 2001 Ralf Baechle
 * Copyright (C) 1994, 1995, 1996 Paul M. Antoine.
 * Copyright (C) 1999 Silicon Graphics, Inc.
 * Copyright (C) 2007  Maciej W. Rozycki
 */
#ifndef _ASM_STACKFRAME_H
#define _ASM_STACKFRAME_H

#include <linux/threads.h>

#include <asm/asm.h>
#include <asm/asmmacro.h>
#include <asm/mipsregs.h>
#include <asm/asm-offsets.h>
#include <asm/thread_info.h>

#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
#define STATMASK 0x3f
#else
#define STATMASK 0x1f
#endif

		.macro	SAVE_AT
		.set	push
		.set	noat
		LONG_S	$1, PT_R1(sp)
		.set	pop
		.endm

		.macro	SAVE_TEMP
#ifdef CONFIG_CPU_HAS_SMARTMIPS
		mflhxu	v1
		LONG_S	v1, PT_LO(sp)
		mflhxu	v1
		LONG_S	v1, PT_HI(sp)
		mflhxu	v1
		LONG_S	v1, PT_ACX(sp)
#elif !defined(CONFIG_CPU_MIPSR6)
		mfhi	v1
#endif
#ifdef CONFIG_32BIT
		LONG_S	$8, PT_R8(sp)
		LONG_S	$9, PT_R9(sp)
#endif
		LONG_S	$10, PT_R10(sp)
		LONG_S	$11, PT_R11(sp)
		LONG_S	$12, PT_R12(sp)
#if !defined(CONFIG_CPU_HAS_SMARTMIPS) && !defined(CONFIG_CPU_MIPSR6)
		LONG_S	v1, PT_HI(sp)
		mflo	v1
#endif
		LONG_S	$13, PT_R13(sp)
		LONG_S	$14, PT_R14(sp)
		LONG_S	$15, PT_R15(sp)
		LONG_S	$24, PT_R24(sp)
#if !defined(CONFIG_CPU_HAS_SMARTMIPS) && !defined(CONFIG_CPU_MIPSR6)
		LONG_S	v1, PT_LO(sp)
#endif
#ifdef CONFIG_CPU_CAVIUM_OCTEON
		/*
		 * The Octeon multiplier state is affected by general
		 * multiply instructions. It must be saved before and
		 * kernel code might corrupt it
		 */
		jal     octeon_mult_save
#endif
		.endm

		.macro	SAVE_STATIC
		LONG_S	$16, PT_R16(sp)
		LONG_S	$17, PT_R17(sp)
		LONG_S	$18, PT_R18(sp)
		LONG_S	$19, PT_R19(sp)
		LONG_S	$20, PT_R20(sp)
		LONG_S	$21, PT_R21(sp)
		LONG_S	$22, PT_R22(sp)
		LONG_S	$23, PT_R23(sp)
		LONG_S	$30, PT_R30(sp)
		.endm

#ifdef CONFIG_SMP
		.macro	get_saved_sp	/* SMP variation */
		ASM_CPUID_MFC0	k0, ASM_SMP_CPUID_REG
#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
		lui	k1, %hi(kernelsp)
#else
		lui	k1, %highest(kernelsp)
		daddiu	k1, %higher(kernelsp)
		dsll	k1, 16
		daddiu	k1, %hi(kernelsp)
		dsll	k1, 16
#endif
		LONG_SRL	k0, SMP_CPUID_PTRSHIFT
		LONG_ADDU	k1, k0
		LONG_L	k1, %lo(kernelsp)(k1)
		.endm

		.macro	set_saved_sp stackp temp temp2
		ASM_CPUID_MFC0	\temp, ASM_SMP_CPUID_REG
		LONG_SRL	\temp, SMP_CPUID_PTRSHIFT
		LONG_S	\stackp, kernelsp(\temp)
		.endm
#else /* !CONFIG_SMP */
		.macro	get_saved_sp	/* Uniprocessor variation */
#ifdef CONFIG_CPU_JUMP_WORKAROUNDS
		/*
		 * Clear BTB (branch target buffer), forbid RAS (return address
		 * stack) to workaround the Out-of-order Issue in Loongson2F
		 * via its diagnostic register.
		 */
		move	k0, ra
		jal	1f
		 nop
1:		jal	1f
		 nop
1:		jal	1f
		 nop
1:		jal	1f
		 nop
1:		move	ra, k0
		li	k0, 3
		mtc0	k0, $22
#endif /* CONFIG_CPU_JUMP_WORKAROUNDS */
#if defined(CONFIG_32BIT) || defined(KBUILD_64BIT_SYM32)
		lui	k1, %hi(kernelsp)
#else
		lui	k1, %highest(kernelsp)
		daddiu	k1, %higher(kernelsp)
		dsll	k1, k1, 16
		daddiu	k1, %hi(kernelsp)
		dsll	k1, k1, 16
#endif
		LONG_L	k1, %lo(kernelsp)(k1)
		.endm

		.macro	set_saved_sp stackp temp temp2
		LONG_S	\stackp, kernelsp
		.endm
#endif

		.macro	SAVE_SOME
		.set	push
		.set	noat
		.set	reorder
		mfc0	k0, CP0_STATUS
		sll	k0, 3		/* extract cu0 bit */
		.set	noreorder
		bltz	k0, 8f
		 move	k1, sp
#ifdef CONFIG_EVA
		/*
		 * Flush interAptiv's Return Prediction Stack (RPS) by writing
		 * EntryHi. Toggling Config7.RPS is slower and less portable.
		 *
		 * The RPS isn't automatically flushed when exceptions are
		 * taken, which can result in kernel mode speculative accesses
		 * to user addresses if the RPS mispredicts. That's harmless
		 * when user and kernel share the same address space, but with
		 * EVA the same user segments may be unmapped to kernel mode,
		 * even containing sensitive MMIO regions or invalid memory.
		 *
		 * This can happen when the kernel sets the return address to
		 * ret_from_* and jr's to the exception handler, which looks
		 * more like a tail call than a function call. If nested calls
		 * don't evict the last user address in the RPS, it will
		 * mispredict the return and fetch from a user controlled
		 * address into the icache.
		 *
		 * More recent EVA-capable cores with MAAR to restrict
		 * speculative accesses aren't affected.
		 */
		MFC0	k0, CP0_ENTRYHI
		MTC0	k0, CP0_ENTRYHI
#endif
		.set	reorder
		/* Called from user mode, new stack. */
		get_saved_sp
#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
8:		move	k0, sp
		PTR_SUBU sp, k1, PT_SIZE
#else
		.set	at=k0
8:		PTR_SUBU k1, PT_SIZE
		.set	noat
		move	k0, sp
		move	sp, k1
#endif
		LONG_S	k0, PT_R29(sp)
		LONG_S	$3, PT_R3(sp)
		/*
		 * You might think that you don't need to save $0,
		 * but the FPU emulator and gdb remote debug stub
		 * need it to operate correctly
		 */
		LONG_S	$0, PT_R0(sp)
		mfc0	v1, CP0_STATUS
		LONG_S	$2, PT_R2(sp)
		LONG_S	v1, PT_STATUS(sp)
		LONG_S	$4, PT_R4(sp)
		mfc0	v1, CP0_CAUSE
		LONG_S	$5, PT_R5(sp)
		LONG_S	v1, PT_CAUSE(sp)
		LONG_S	$6, PT_R6(sp)
		MFC0	v1, CP0_EPC
		LONG_S	$7, PT_R7(sp)
#ifdef CONFIG_64BIT
		LONG_S	$8, PT_R8(sp)
		LONG_S	$9, PT_R9(sp)
#endif
		LONG_S	v1, PT_EPC(sp)
		LONG_S	$25, PT_R25(sp)
		LONG_S	$28, PT_R28(sp)
		LONG_S	$31, PT_R31(sp)
		ori	$28, sp, _THREAD_MASK
		xori	$28, _THREAD_MASK
#ifdef CONFIG_CPU_CAVIUM_OCTEON
		.set    mips64
		pref    0, 0($28)       /* Prefetch the current pointer */
#endif
		.set	pop
		.endm

		.macro	SAVE_ALL
		SAVE_SOME
		SAVE_AT
		SAVE_TEMP
		SAVE_STATIC
		.endm

		.macro	RESTORE_AT
		.set	push
		.set	noat
		LONG_L	$1,  PT_R1(sp)
		.set	pop
		.endm

		.macro	RESTORE_TEMP
#ifdef CONFIG_CPU_CAVIUM_OCTEON
		/* Restore the Octeon multiplier state */
		jal	octeon_mult_restore
#endif
#ifdef CONFIG_CPU_HAS_SMARTMIPS
		LONG_L	$24, PT_ACX(sp)
		mtlhx	$24
		LONG_L	$24, PT_HI(sp)
		mtlhx	$24
		LONG_L	$24, PT_LO(sp)
		mtlhx	$24
#elif !defined(CONFIG_CPU_MIPSR6)
		LONG_L	$24, PT_LO(sp)
		mtlo	$24
		LONG_L	$24, PT_HI(sp)
		mthi	$24
#endif
#ifdef CONFIG_32BIT
		LONG_L	$8, PT_R8(sp)
		LONG_L	$9, PT_R9(sp)
#endif
		LONG_L	$10, PT_R10(sp)
		LONG_L	$11, PT_R11(sp)
		LONG_L	$12, PT_R12(sp)
		LONG_L	$13, PT_R13(sp)
		LONG_L	$14, PT_R14(sp)
		LONG_L	$15, PT_R15(sp)
		LONG_L	$24, PT_R24(sp)
		.endm

		.macro	RESTORE_STATIC
		LONG_L	$16, PT_R16(sp)
		LONG_L	$17, PT_R17(sp)
		LONG_L	$18, PT_R18(sp)
		LONG_L	$19, PT_R19(sp)
		LONG_L	$20, PT_R20(sp)
		LONG_L	$21, PT_R21(sp)
		LONG_L	$22, PT_R22(sp)
		LONG_L	$23, PT_R23(sp)
		LONG_L	$30, PT_R30(sp)
		.endm

#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)

		.macro	RESTORE_SOME
		.set	push
		.set	reorder
		.set	noat
		mfc0	a0, CP0_STATUS
		li	v1, 0xff00
		ori	a0, STATMASK
		xori	a0, STATMASK
		mtc0	a0, CP0_STATUS
		and	a0, v1
		LONG_L	v0, PT_STATUS(sp)
		nor	v1, $0, v1
		and	v0, v1
		or	v0, a0
		mtc0	v0, CP0_STATUS
		LONG_L	$31, PT_R31(sp)
		LONG_L	$28, PT_R28(sp)
		LONG_L	$25, PT_R25(sp)
		LONG_L	$7,  PT_R7(sp)
		LONG_L	$6,  PT_R6(sp)
		LONG_L	$5,  PT_R5(sp)
		LONG_L	$4,  PT_R4(sp)
		LONG_L	$3,  PT_R3(sp)
		LONG_L	$2,  PT_R2(sp)
		.set	pop
		.endm

		.macro	RESTORE_SP_AND_RET
		.set	push
		.set	noreorder
		LONG_L	k0, PT_EPC(sp)
		LONG_L	sp, PT_R29(sp)
		jr	k0
		 rfe
		.set	pop
		.endm

#else
		.macro	RESTORE_SOME
		.set	push
		.set	reorder
		.set	noat
		mfc0	a0, CP0_STATUS
		ori	a0, STATMASK
		xori	a0, STATMASK
		mtc0	a0, CP0_STATUS
		li	v1, 0xff00
		and	a0, v1
		LONG_L	v0, PT_STATUS(sp)
		nor	v1, $0, v1
		and	v0, v1
		or	v0, a0
		mtc0	v0, CP0_STATUS
		LONG_L	v1, PT_EPC(sp)
		MTC0	v1, CP0_EPC
		LONG_L	$31, PT_R31(sp)
		LONG_L	$28, PT_R28(sp)
		LONG_L	$25, PT_R25(sp)
#ifdef CONFIG_64BIT
		LONG_L	$8, PT_R8(sp)
		LONG_L	$9, PT_R9(sp)
#endif
		LONG_L	$7,  PT_R7(sp)
		LONG_L	$6,  PT_R6(sp)
		LONG_L	$5,  PT_R5(sp)
		LONG_L	$4,  PT_R4(sp)
		LONG_L	$3,  PT_R3(sp)
		LONG_L	$2,  PT_R2(sp)
		.set	pop
		.endm

		.macro	RESTORE_SP_AND_RET
		LONG_L	sp, PT_R29(sp)
		.set	arch=r4000
		eret
		.set	mips0
		.endm

#endif

		.macro	RESTORE_SP
		LONG_L	sp, PT_R29(sp)
		.endm

		.macro	RESTORE_ALL
		RESTORE_TEMP
		RESTORE_STATIC
		RESTORE_AT
		RESTORE_SOME
		RESTORE_SP
		.endm

		.macro	RESTORE_ALL_AND_RET
		RESTORE_TEMP
		RESTORE_STATIC
		RESTORE_AT
		RESTORE_SOME
		RESTORE_SP_AND_RET
		.endm

/*
 * Move to kernel mode and disable interrupts.
 * Set cp0 enable bit as sign that we're running on the kernel stack
 */
		.macro	CLI
		mfc0	t0, CP0_STATUS
		li	t1, ST0_CU0 | STATMASK
		or	t0, t1
		xori	t0, STATMASK
		mtc0	t0, CP0_STATUS
		irq_disable_hazard
		.endm

/*
 * Move to kernel mode and enable interrupts.
 * Set cp0 enable bit as sign that we're running on the kernel stack
 */
		.macro	STI
		mfc0	t0, CP0_STATUS
		li	t1, ST0_CU0 | STATMASK
		or	t0, t1
		xori	t0, STATMASK & ~1
		mtc0	t0, CP0_STATUS
		irq_enable_hazard
		.endm

/*
 * Just move to kernel mode and leave interrupts as they are.  Note
 * for the R3000 this means copying the previous enable from IEp.
 * Set cp0 enable bit as sign that we're running on the kernel stack
 */
		.macro	KMODE
		mfc0	t0, CP0_STATUS
		li	t1, ST0_CU0 | (STATMASK & ~1)
#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
		andi	t2, t0, ST0_IEP
		srl	t2, 2
		or	t0, t2
#endif
		or	t0, t1
		xori	t0, STATMASK & ~1
		mtc0	t0, CP0_STATUS
		irq_disable_hazard
		.endm

#endif /* _ASM_STACKFRAME_H */
OpenPOWER on IntegriCloud