xref: /openbmc/linux/arch/powerpc/kernel/head_32.h (revision abcda807)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __HEAD_32_H__
3 #define __HEAD_32_H__
4 
5 #include <asm/ptrace.h>	/* for STACK_FRAME_REGS_MARKER */
6 
7 /*
8  * Exception entry code.  This code runs with address translation
9  * turned off, i.e. using physical addresses.
10  * We assume sprg3 has the physical address of the current
11  * task's thread_struct.
12  */
13 .macro EXCEPTION_PROLOG handle_dar_dsisr=0
14 	EXCEPTION_PROLOG_0	handle_dar_dsisr=\handle_dar_dsisr
15 	EXCEPTION_PROLOG_1
16 	EXCEPTION_PROLOG_2	handle_dar_dsisr=\handle_dar_dsisr
17 .endm
18 
19 .macro EXCEPTION_PROLOG_0 handle_dar_dsisr=0
20 	mtspr	SPRN_SPRG_SCRATCH0,r10
21 	mtspr	SPRN_SPRG_SCRATCH1,r11
22 #ifdef CONFIG_VMAP_STACK
23 	mfspr	r10, SPRN_SPRG_THREAD
24 	.if	\handle_dar_dsisr
25 	mfspr	r11, SPRN_DAR
26 	stw	r11, DAR(r10)
27 	mfspr	r11, SPRN_DSISR
28 	stw	r11, DSISR(r10)
29 	.endif
30 	mfspr	r11, SPRN_SRR0
31 	stw	r11, SRR0(r10)
32 #endif
33 	mfspr	r11, SPRN_SRR1		/* check whether user or kernel */
34 #ifdef CONFIG_VMAP_STACK
35 	stw	r11, SRR1(r10)
36 #endif
37 	mfcr	r10
38 	andi.	r11, r11, MSR_PR
39 .endm
40 
41 .macro EXCEPTION_PROLOG_1 for_rtas=0
42 #ifdef CONFIG_VMAP_STACK
43 	mr	r11, r1
44 	subi	r1, r1, INT_FRAME_SIZE		/* use r1 if kernel */
45 	beq	1f
46 	mfspr	r1,SPRN_SPRG_THREAD
47 	lwz	r1,TASK_STACK-THREAD(r1)
48 	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
49 #else
50 	subi	r11, r1, INT_FRAME_SIZE		/* use r1 if kernel */
51 	beq	1f
52 	mfspr	r11,SPRN_SPRG_THREAD
53 	lwz	r11,TASK_STACK-THREAD(r11)
54 	addi	r11, r11, THREAD_SIZE - INT_FRAME_SIZE
55 #endif
56 1:
57 	tophys_novmstack r11, r11
58 #ifdef CONFIG_VMAP_STACK
59 	mtcrf	0x7f, r1
60 	bt	32 - THREAD_ALIGN_SHIFT, stack_overflow
61 #endif
62 .endm
63 
64 .macro EXCEPTION_PROLOG_2 handle_dar_dsisr=0
65 #ifdef CONFIG_VMAP_STACK
66 	mtcr	r10
67 	li	r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
68 	mtmsr	r10
69 	isync
70 #else
71 	stw	r10,_CCR(r11)		/* save registers */
72 #endif
73 	mfspr	r10, SPRN_SPRG_SCRATCH0
74 #ifdef CONFIG_VMAP_STACK
75 	stw	r11,GPR1(r1)
76 	stw	r11,0(r1)
77 	mr	r11, r1
78 #else
79 	stw	r1,GPR1(r11)
80 	stw	r1,0(r11)
81 	tovirt(r1, r11)		/* set new kernel sp */
82 #endif
83 	stw	r12,GPR12(r11)
84 	stw	r9,GPR9(r11)
85 	stw	r10,GPR10(r11)
86 #ifdef CONFIG_VMAP_STACK
87 	mfcr	r10
88 	stw	r10, _CCR(r11)
89 #endif
90 	mfspr	r12,SPRN_SPRG_SCRATCH1
91 	stw	r12,GPR11(r11)
92 	mflr	r10
93 	stw	r10,_LINK(r11)
94 #ifdef CONFIG_VMAP_STACK
95 	mfspr	r12, SPRN_SPRG_THREAD
96 	tovirt(r12, r12)
97 	.if	\handle_dar_dsisr
98 	lwz	r10, DAR(r12)
99 	stw	r10, _DAR(r11)
100 	lwz	r10, DSISR(r12)
101 	stw	r10, _DSISR(r11)
102 	.endif
103 	lwz	r9, SRR1(r12)
104 	andi.	r10, r9, MSR_PR
105 	lwz	r12, SRR0(r12)
106 #else
107 	mfspr	r12,SPRN_SRR0
108 	mfspr	r9,SPRN_SRR1
109 #endif
110 #ifdef CONFIG_40x
111 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
112 #else
113 #ifdef CONFIG_VMAP_STACK
114 	li	r10, MSR_KERNEL & ~MSR_IR /* can take exceptions */
115 #else
116 	li	r10,MSR_KERNEL & ~(MSR_IR|MSR_DR) /* can take exceptions */
117 #endif
118 	mtmsr	r10			/* (except for mach check in rtas) */
119 #endif
120 	stw	r0,GPR0(r11)
121 	lis	r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
122 	addi	r10,r10,STACK_FRAME_REGS_MARKER@l
123 	stw	r10,8(r11)
124 	SAVE_4GPRS(3, r11)
125 	SAVE_2GPRS(7, r11)
126 .endm
127 
128 .macro SYSCALL_ENTRY trapno
129 	mfspr	r12,SPRN_SPRG_THREAD
130 	mfspr	r9, SPRN_SRR1
131 #ifdef CONFIG_VMAP_STACK
132 	mfspr	r11, SPRN_SRR0
133 	mtctr	r11
134 #endif
135 	andi.	r11, r9, MSR_PR
136 	lwz	r11,TASK_STACK-THREAD(r12)
137 	beq-	99f
138 	addi	r11, r11, THREAD_SIZE - INT_FRAME_SIZE
139 #ifdef CONFIG_VMAP_STACK
140 	li	r10, MSR_KERNEL & ~(MSR_IR | MSR_RI) /* can take DTLB miss */
141 	mtmsr	r10
142 	isync
143 #endif
144 	tovirt_vmstack r12, r12
145 	tophys_novmstack r11, r11
146 	mflr	r10
147 	stw	r10, _LINK(r11)
148 #ifdef CONFIG_VMAP_STACK
149 	mfctr	r10
150 #else
151 	mfspr	r10,SPRN_SRR0
152 #endif
153 	stw	r1,GPR1(r11)
154 	stw	r1,0(r11)
155 	tovirt_novmstack r1, r11	/* set new kernel sp */
156 	stw	r10,_NIP(r11)
157 	mfcr	r10
158 	rlwinm	r10,r10,0,4,2	/* Clear SO bit in CR */
159 	stw	r10,_CCR(r11)		/* save registers */
160 #ifdef CONFIG_40x
161 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
162 #else
163 #ifdef CONFIG_VMAP_STACK
164 	LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~MSR_IR) /* can take exceptions */
165 #else
166 	LOAD_REG_IMMEDIATE(r10, MSR_KERNEL & ~(MSR_IR|MSR_DR)) /* can take exceptions */
167 #endif
168 	mtmsr	r10			/* (except for mach check in rtas) */
169 #endif
170 	lis	r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
171 	stw	r2,GPR2(r11)
172 	addi	r10,r10,STACK_FRAME_REGS_MARKER@l
173 	stw	r9,_MSR(r11)
174 	li	r2, \trapno + 1
175 	stw	r10,8(r11)
176 	stw	r2,_TRAP(r11)
177 	SAVE_GPR(0, r11)
178 	SAVE_4GPRS(3, r11)
179 	SAVE_2GPRS(7, r11)
180 	addi	r11,r1,STACK_FRAME_OVERHEAD
181 	addi	r2,r12,-THREAD
182 	stw	r11,PT_REGS(r12)
183 #if defined(CONFIG_40x)
184 	/* Check to see if the dbcr0 register is set up to debug.  Use the
185 	   internal debug mode bit to do this. */
186 	lwz	r12,THREAD_DBCR0(r12)
187 	andis.	r12,r12,DBCR0_IDM@h
188 #endif
189 	ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
190 #if defined(CONFIG_40x)
191 	beq+	3f
192 	/* From user and task is ptraced - load up global dbcr0 */
193 	li	r12,-1			/* clear all pending debug events */
194 	mtspr	SPRN_DBSR,r12
195 	lis	r11,global_dbcr0@ha
196 	tophys(r11,r11)
197 	addi	r11,r11,global_dbcr0@l
198 	lwz	r12,0(r11)
199 	mtspr	SPRN_DBCR0,r12
200 	lwz	r12,4(r11)
201 	addi	r12,r12,-1
202 	stw	r12,4(r11)
203 #endif
204 
205 3:
206 	tovirt_novmstack r2, r2 	/* set r2 to current */
207 	lis	r11, transfer_to_syscall@h
208 	ori	r11, r11, transfer_to_syscall@l
209 #ifdef CONFIG_TRACE_IRQFLAGS
210 	/*
211 	 * If MSR is changing we need to keep interrupts disabled at this point
212 	 * otherwise we might risk taking an interrupt before we tell lockdep
213 	 * they are enabled.
214 	 */
215 	LOAD_REG_IMMEDIATE(r10, MSR_KERNEL)
216 	rlwimi	r10, r9, 0, MSR_EE
217 #else
218 	LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE)
219 #endif
220 #if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
221 	mtspr	SPRN_NRI, r0
222 #endif
223 	mtspr	SPRN_SRR1,r10
224 	mtspr	SPRN_SRR0,r11
225 	RFI				/* jump to handler, enable MMU */
226 99:	b	ret_from_kernel_syscall
227 .endm
228 
229 .macro save_dar_dsisr_on_stack reg1, reg2, sp
230 #ifndef CONFIG_VMAP_STACK
231 	mfspr	\reg1, SPRN_DAR
232 	mfspr	\reg2, SPRN_DSISR
233 	stw	\reg1, _DAR(\sp)
234 	stw	\reg2, _DSISR(\sp)
235 #endif
236 .endm
237 
238 .macro get_and_save_dar_dsisr_on_stack reg1, reg2, sp
239 #ifdef CONFIG_VMAP_STACK
240 	lwz	\reg1, _DAR(\sp)
241 	lwz	\reg2, _DSISR(\sp)
242 #else
243 	save_dar_dsisr_on_stack \reg1, \reg2, \sp
244 #endif
245 .endm
246 
247 .macro tovirt_vmstack dst, src
248 #ifdef CONFIG_VMAP_STACK
249 	tovirt(\dst, \src)
250 #else
251 	.ifnc	\dst, \src
252 	mr	\dst, \src
253 	.endif
254 #endif
255 .endm
256 
257 .macro tovirt_novmstack dst, src
258 #ifndef CONFIG_VMAP_STACK
259 	tovirt(\dst, \src)
260 #else
261 	.ifnc	\dst, \src
262 	mr	\dst, \src
263 	.endif
264 #endif
265 .endm
266 
267 .macro tophys_novmstack dst, src
268 #ifndef CONFIG_VMAP_STACK
269 	tophys(\dst, \src)
270 #else
271 	.ifnc	\dst, \src
272 	mr	\dst, \src
273 	.endif
274 #endif
275 .endm
276 
277 /*
278  * Note: code which follows this uses cr0.eq (set if from kernel),
279  * r11, r12 (SRR0), and r9 (SRR1).
280  *
281  * Note2: once we have set r1 we are in a position to take exceptions
282  * again, and we could thus set MSR:RI at that point.
283  */
284 
285 /*
286  * Exception vectors.
287  */
288 #ifdef CONFIG_PPC_BOOK3S
289 #define	START_EXCEPTION(n, label)		\
290 	. = n;					\
291 	DO_KVM n;				\
292 label:
293 
294 #else
295 #define	START_EXCEPTION(n, label)		\
296 	. = n;					\
297 label:
298 
299 #endif
300 
301 #define EXCEPTION(n, label, hdlr, xfer)		\
302 	START_EXCEPTION(n, label)		\
303 	EXCEPTION_PROLOG;			\
304 	addi	r3,r1,STACK_FRAME_OVERHEAD;	\
305 	xfer(n, hdlr)
306 
307 #define EXC_XFER_TEMPLATE(hdlr, trap, msr, tfer, ret)		\
308 	li	r10,trap;					\
309 	stw	r10,_TRAP(r11);					\
310 	LOAD_REG_IMMEDIATE(r10, msr);				\
311 	bl	tfer;						\
312 	.long	hdlr;						\
313 	.long	ret
314 
315 #define EXC_XFER_STD(n, hdlr)		\
316 	EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, transfer_to_handler_full,	\
317 			  ret_from_except_full)
318 
319 #define EXC_XFER_LITE(n, hdlr)		\
320 	EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, transfer_to_handler, \
321 			  ret_from_except)
322 
323 .macro vmap_stack_overflow_exception
324 #ifdef CONFIG_VMAP_STACK
325 #ifdef CONFIG_SMP
326 	mfspr	r1, SPRN_SPRG_THREAD
327 	lwz	r1, TASK_CPU - THREAD(r1)
328 	slwi	r1, r1, 3
329 	addis	r1, r1, emergency_ctx@ha
330 #else
331 	lis	r1, emergency_ctx@ha
332 #endif
333 	lwz	r1, emergency_ctx@l(r1)
334 	cmpwi	cr1, r1, 0
335 	bne	cr1, 1f
336 	lis	r1, init_thread_union@ha
337 	addi	r1, r1, init_thread_union@l
338 1:	addi	r1, r1, THREAD_SIZE - INT_FRAME_SIZE
339 	EXCEPTION_PROLOG_2
340 	SAVE_NVGPRS(r11)
341 	addi	r3, r1, STACK_FRAME_OVERHEAD
342 	EXC_XFER_STD(0, stack_overflow_exception)
343 #endif
344 .endm
345 
346 #endif /* __HEAD_32_H__ */
347