summaryrefslogtreecommitdiff
path: root/arch/powerpc/kernel/head_32.h
blob: 7c767765071dac3ae9efa33162bce1a0d5c47207 (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
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __HEAD_32_H__
#define __HEAD_32_H__

#include <asm/ptrace.h>	/* for STACK_FRAME_REGS_MARKER */

/*
 * Exception entry code.  This code runs with address translation
 * turned off, i.e. using physical addresses.
 * We assume sprg3 has the physical address of the current
 * task's thread_struct.
 */
.macro EXCEPTION_PROLOG handle_dar_dsisr=0
	EXCEPTION_PROLOG_0	handle_dar_dsisr=\handle_dar_dsisr
	EXCEPTION_PROLOG_1
	EXCEPTION_PROLOG_2	handle_dar_dsisr=\handle_dar_dsisr
.endm

.macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0
	mtspr	SPRN_SPRG_SCRATCH0,r10
	mtspr	SPRN_SPRG_SCRATCH1,r11
#ifdef CONFIG_VMAP_STACK
	mfspr	r10, SPRN_SPRG_THREAD
	.if	\handle_dar_dsisr
	mfspr	r11, SPRN_DAR
	stw	r11, DAR(r10)
	mfspr	r11, SPRN_DSISR
	stw	r11, DSISR(r10)
	.endif
	mfspr	r11, SPRN_SRR0
	stw	r11, SRR0(r10)
#endif
	mfspr	r11, SPRN_SRR1		/* check whether user or kernel */
#ifdef CONFIG_VMAP_STACK
	stw	r11, SRR1(r10)
#endif
	mfcr	r10
	andi.	r11, r11, MSR_PR
.endm

.macro EXCEPTION_PROLOG_1 for_rtas=0
#ifdef CONFIG_VMAP_STACK
	mr	r11, r1
	subi	r1, r1, INT_FRAME_SIZE		/* use r1 if kernel */
	beq	1f
	mfspr	r1,SPRN_SPRG_THREAD
	lwz	r1,TASK_STACK-THREAD(r1)
	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
#else
	subi	r11, r1, INT_FRAME_SIZE		/* use r1 if kernel */
	beq	1f
	mfspr	r11,SPRN_SPRG_THREAD
	lwz	r11,TASK_STACK-THREAD(r11)
	addi	r11, r11, THREAD_SIZE - INT_FRAME_SIZE
#endif
1:
	tophys_novmstack r11, r11
#ifdef CONFIG_VMAP_STACK
	mtcrf	0x7f, r1
	bt	32 - THREAD_ALIGN_SHIFT, stack_overflow
#endif
.endm

.macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
#ifdef CONFIG_VMAP_STACK
	mtcr	r10
	li	r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
	mtmsr	r10
	isync
#else
	stw	r10,_CCR(r11)		/* save registers */
#endif
	mfspr	r10, SPRN_SPRG_SCRATCH0
#ifdef CONFIG_VMAP_STACK
	stw	r11,GPR1(r1)
	stw	r11,0(r1)
	mr	r11, r1
#else
	stw	r1,GPR1(r11)
	stw	r1,0(r11)
	tovirt(r1, r11)		/* set new kernel sp */
#endif
	stw	r12,GPR12(r11)
	stw	r9,GPR9(r11)
	stw	r10,GPR10(r11)
#ifdef CONFIG_VMAP_STACK
	mfcr	r10
	stw	r10, _CCR(r11)
#endif
	mfspr	r12,SPRN_SPRG_SCRATCH1
	stw	r12,GPR11(r11)
	mflr	r10
	stw	r10,_LINK(r11)
#ifdef CONFIG_VMAP_STACK
	mfspr	r12, SPRN_SPRG_THREAD
	tovirt(r12, r12)
	.if	\handle_dar_dsisr
	lwz	r10, DAR(r12)
	stw	r10, _DAR(r11)
	lwz	r10, DSISR(r12)
	stw	r10, _DSISR(r11)
	.endif
	lwz	r9, SRR1(r12)
	andi.	r10, r9, MSR_PR
	lwz	r12, SRR0(r12)
#else
	mfspr	r12,SPRN_SRR0
	mfspr	r9,SPRN_SRR1
#endif
#ifdef CONFIG_40x
	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
#else
#ifdef CONFIG_VMAP_STACK
	li	r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
#else
	li	r10,MSR_KERNEL & ~(MSR_IR|MSR_DR) /* can take exceptions */
#endif
	mtmsr	r10			/* (except for mach check in rtas) */
#endif
	stw	r0,GPR0(r11)
	lis	r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
	addi	r10,r10,STACK_FRAME_REGS_MARKER@l
	stw	r10,8(r11)
	SAVE_4GPRS(3, r11)
	SAVE_2GPRS(7, r11)
.endm

.macro SYSCALL_ENTRY trapno
	mfspr	r12,SPRN_SPRG_THREAD
	mfspr	r9, SPRN_SRR1
#ifdef CONFIG_VMAP_STACK
	mfspr	r11, SPRN_SRR0
	mtctr	r11
#endif
	andi.	r11, r9, MSR_PR
	lwz	r11,TASK_STACK-THREAD(r12)
	beq-	99f
	addi	r11, r11, THREAD_SIZE - INT_FRAME_SIZE
#ifdef CONFIG_VMAP_STACK
	li	r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
	mtmsr	r10
	isync
#endif
	tovirt_vmstack r12, r12
	tophys_novmstack r11, r11
	mflr	r10
	stw	r10, _LINK(r11)
#ifdef CONFIG_VMAP_STACK
	mfctr	r10
#else
	mfspr	r10,SPRN_SRR0
#endif
	stw	r1,GPR1(r11)
	stw	r1,0(r11)
	tovirt_novmstack r1, r11	/* set new kernel sp */
	stw	r10,_NIP(r11)
	mfcr	r10
	rlwinm	r10,r10,0,4,2	/* Clear SO bit in CR */
	stw	r10,_CCR(r11)		/* save registers */
#ifdef CONFIG_40x
	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
#else
#ifdef CONFIG_VMAP_STACK
	LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~MSR_IR) /* can take exceptions */
#else
	LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR|MSR_DR)) /* can take exceptions */
#endif
	mtmsr	r10			/* (except for mach check in rtas) */
#endif
	lis	r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
	stw	r2,GPR2(r11)
	addi	r10,r10,STACK_FRAME_REGS_MARKER@l
	stw	r9,_MSR(r11)
	li	r2, \trapno + 1
	stw	r10,8(r11)
	stw	r2,_TRAP(r11)
	SAVE_GPR(0, r11)
	SAVE_4GPRS(3, r11)
	SAVE_2GPRS(7, r11)
	addi	r11,r1,STACK_FRAME_OVERHEAD
	addi	r2,r12,-THREAD
	stw	r11,PT_REGS(r12)
#if defined(CONFIG_40x)
	/* Check to see if the dbcr0 register is set up to debug.  Use the
	   internal debug mode bit to do this. */
	lwz	r12,THREAD_DBCR0(r12)
	andis.	r12,r12,DBCR0_IDM@h
#endif
	ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
#if defined(CONFIG_40x)
	beq+	3f
	/* From user and task is ptraced - load up global dbcr0 */
	li	r12,-1			/* clear all pending debug events */
	mtspr	SPRN_DBSR,r12
	lis	r11,global_dbcr0@ha
	tophys(r11,r11)
	addi	r11,r11,global_dbcr0@l
	lwz	r12,0(r11)
	mtspr	SPRN_DBCR0,r12
	lwz	r12,4(r11)
	addi	r12,r12,-1
	stw	r12,4(r11)
#endif

3:
	tovirt_novmstack r2, r2 	/* set r2 to current */
	lis	r11, transfer_to_syscall@h
	ori	r11, r11, transfer_to_syscall@l
#ifdef CONFIG_TRACE_IRQFLAGS
	/*
	 * If MSR is changing we need to keep interrupts disabled at this point
	 * otherwise we might risk taking an interrupt before we tell lockdep
	 * they are enabled.
	 */
	LOAD_REG_IMMEDIATE(r10, MSR_KERNEL)
	rlwimi	r10, r9, 0, MSR_EE
#else
	LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE)
#endif
#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
	mtspr	SPRN_NRI, r0
#endif
	mtspr	SPRN_SRR1,r10
	mtspr	SPRN_SRR0,r11
	RFI				/* jump to handler, enable MMU */
99:	b	ret_from_kernel_syscall
.endm

.macro save_dar_dsisr_on_stack reg1, reg2, sp
#ifndef CONFIG_VMAP_STACK
	mfspr	\reg1, SPRN_DAR
	mfspr	\reg2, SPRN_DSISR
	stw	\reg1, _DAR(\sp)
	stw	\reg2, _DSISR(\sp)
#endif
.endm

.macro get_and_save_dar_dsisr_on_stack reg1, reg2, sp
#ifdef CONFIG_VMAP_STACK
	lwz	\reg1, _DAR(\sp)
	lwz	\reg2, _DSISR(\sp)
#else
	save_dar_dsisr_on_stack \reg1, \reg2, \sp
#endif
.endm

.macro tovirt_vmstack dst, src
#ifdef CONFIG_VMAP_STACK
	tovirt(\dst, \src)
#else
	.ifnc	\dst, \src
	mr	\dst, \src
	.endif
#endif
.endm

.macro tovirt_novmstack dst, src
#ifndef CONFIG_VMAP_STACK
	tovirt(\dst, \src)
#else
	.ifnc	\dst, \src
	mr	\dst, \src
	.endif
#endif
.endm

.macro tophys_novmstack dst, src
#ifndef CONFIG_VMAP_STACK
	tophys(\dst, \src)
#else
	.ifnc	\dst, \src
	mr	\dst, \src
	.endif
#endif
.endm

/*
 * Note: code which follows this uses cr0.eq (set if from kernel),
 * r11, r12 (SRR0), and r9 (SRR1).
 *
 * Note2: once we have set r1 we are in a position to take exceptions
 * again, and we could thus set MSR:RI at that point.
 */

/*
 * Exception vectors.
 */
#ifdef CONFIG_PPC_BOOK3S
#define	START_EXCEPTION(n, label)		\
	. = n;					\
	DO_KVM n;				\
label:

#else
#define	START_EXCEPTION(n, label)		\
	. = n;					\
label:

#endif

#define EXCEPTION(n, label, hdlr, xfer)		\
	START_EXCEPTION(n, label)		\
	EXCEPTION_PROLOG;			\
	addi	r3,r1,STACK_FRAME_OVERHEAD;	\
	xfer(n, hdlr)

#define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret)		\
	li	r10,trap;					\
	stw	r10,_TRAP(r11);					\
	LOAD_REG_IMMEDIATE(r10, msr);				\
	bl	tfer;						\
	.long	hdlr;						\
	.long	ret

#define EXC_XFER_STD(n, hdlr)		\
	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, transfer_to_handler_full,	\
			  ret_from_except_full)

#define EXC_XFER_LITE(n, hdlr)		\
	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, transfer_to_handler, \
			  ret_from_except)

.macro vmap_stack_overflow_exception
#ifdef CONFIG_VMAP_STACK
#ifdef CONFIG_SMP
	mfspr	r1, SPRN_SPRG_THREAD
	lwz	r1, TASK_CPU - THREAD(r1)
	slwi	r1, r1, 3
	addis	r1, r1, emergency_ctx@ha
#else
	lis	r1, emergency_ctx@ha
#endif
	lwz	r1, emergency_ctx@l(r1)
	cmpwi	cr1, r1, 0
	bne	cr1, 1f
	lis	r1, init_thread_union@ha
	addi	r1, r1, init_thread_union@l
1:	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
	EXCEPTION_PROLOG_2
	SAVE_NVGPRS(r11)
	addi	r3, r1, STACK_FRAME_OVERHEAD
	EXC_XFER_STD(0, stack_overflow_exception)
#endif
.endm

#endif /* __HEAD_32_H__ */