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 trapno name handle_dar_dsisr=0
14 EXCEPTION_PROLOG_0 handle_dar_dsisr=\handle_dar_dsisr
15 EXCEPTION_PROLOG_1
16 EXCEPTION_PROLOG_2 \trapno \name 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 mfspr r10, SPRN_SPRG_THREAD
23 .if \handle_dar_dsisr
24 mfspr r11, SPRN_DAR
25 stw r11, DAR(r10)
26 mfspr r11, SPRN_DSISR
27 stw r11, DSISR(r10)
28 .endif
29 mfspr r11, SPRN_SRR0
30 stw r11, SRR0(r10)
31 mfspr r11, SPRN_SRR1 /* check whether user or kernel */
32 stw r11, SRR1(r10)
33 mfcr r10
34 andi. r11, r11, MSR_PR
35.endm
36
37.macro EXCEPTION_PROLOG_1
38 mtspr SPRN_SPRG_SCRATCH2,r1
39 subi r1, r1, INT_FRAME_SIZE /* use r1 if kernel */
40 beq 1f
41 mfspr r1,SPRN_SPRG_THREAD
42 lwz r1,TASK_STACK-THREAD(r1)
43 addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
441:
45#ifdef CONFIG_VMAP_STACK
46 mtcrf 0x3f, r1
47 bt 32 - THREAD_ALIGN_SHIFT, vmap_stack_overflow
48#endif
49.endm
50
51.macro EXCEPTION_PROLOG_2 trapno name handle_dar_dsisr=0
52#ifdef CONFIG_PPC_8xx
53 .if \handle_dar_dsisr
54 li r11, RPN_PATTERN
55 mtspr SPRN_DAR, r11 /* Tag DAR, to be used in DTLB Error */
56 .endif
57#endif
58 LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~MSR_RI) /* re-enable MMU */
59 mtspr SPRN_SRR1, r11
60 lis r11, 1f@h
61 ori r11, r11, 1f@l
62 mtspr SPRN_SRR0, r11
63 mfspr r11, SPRN_SPRG_SCRATCH2
64 rfi
65
66 .text
67\name\()_virt:
681:
69 stw r11,GPR1(r1)
70 stw r11,0(r1)
71 mr r11, r1
72 stw r10,_CCR(r11) /* save registers */
73 stw r12,GPR12(r11)
74 stw r9,GPR9(r11)
75 mfspr r10,SPRN_SPRG_SCRATCH0
76 mfspr r12,SPRN_SPRG_SCRATCH1
77 stw r10,GPR10(r11)
78 stw r12,GPR11(r11)
79 mflr r10
80 stw r10,_LINK(r11)
81 mfspr r12, SPRN_SPRG_THREAD
82 tovirt(r12, r12)
83 .if \handle_dar_dsisr
84 lwz r10, DAR(r12)
85 stw r10, _DAR(r11)
86 lwz r10, DSISR(r12)
87 stw r10, _DSISR(r11)
88 .endif
89 lwz r9, SRR1(r12)
90 lwz r12, SRR0(r12)
91#ifdef CONFIG_PPC_8xx
92 mtspr SPRN_EID, r2 /* Set MSR_RI */
93#else
94 li r10, MSR_KERNEL /* can take exceptions */
95 mtmsr r10 /* (except for mach check in rtas) */
96#endif
97 COMMON_EXCEPTION_PROLOG_END \trapno
98_ASM_NOKPROBE_SYMBOL(\name\()_virt)
99.endm
100
101.macro COMMON_EXCEPTION_PROLOG_END trapno
102 stw r0,GPR0(r1)
103 lis r10,STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
104 addi r10,r10,STACK_FRAME_REGS_MARKER@l
105 stw r10,STACK_INT_FRAME_MARKER(r1)
106 li r10, \trapno
107 stw r10,_TRAP(r1)
108 SAVE_GPRS(3, 8, r1)
109 SAVE_NVGPRS(r1)
110 stw r2,GPR2(r1)
111 stw r12,_NIP(r1)
112 stw r9,_MSR(r1)
113 mfctr r10
114 mfspr r2,SPRN_SPRG_THREAD
115 stw r10,_CTR(r1)
116 tovirt(r2, r2)
117 mfspr r10,SPRN_XER
118 addi r2, r2, -THREAD
119 stw r10,_XER(r1)
120 addi r3,r1,STACK_INT_FRAME_REGS
121.endm
122
123.macro prepare_transfer_to_handler
124#ifdef CONFIG_PPC_BOOK3S_32
125 andi. r12,r9,MSR_PR
126 bne 777f
127 bl prepare_transfer_to_handler
128#ifdef CONFIG_PPC_KUEP
129 b 778f
130777:
131 bl __kuep_lock
132778:
133#endif
134777:
135#endif
136.endm
137
138.macro SYSCALL_ENTRY trapno
139 mfspr r9, SPRN_SRR1
140 mfspr r12, SPRN_SRR0
141 LOAD_REG_IMMEDIATE(r11, MSR_KERNEL) /* can take exceptions */
142 lis r10, 1f@h
143 ori r10, r10, 1f@l
144 mtspr SPRN_SRR1, r11
145 mtspr SPRN_SRR0, r10
146 mfspr r10,SPRN_SPRG_THREAD
147 mr r11, r1
148 lwz r1,TASK_STACK-THREAD(r10)
149 tovirt(r10, r10)
150 addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
151 rfi
1521:
153 stw r12,_NIP(r1)
154 mfcr r12
155 rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */
156 stw r12,_CCR(r1)
157 b transfer_to_syscall /* jump to handler */
158.endm
159
160/*
161 * Note: code which follows this uses cr0.eq (set if from kernel),
162 * r11, r12 (SRR0), and r9 (SRR1).
163 *
164 * Note2: once we have set r1 we are in a position to take exceptions
165 * again, and we could thus set MSR:RI at that point.
166 */
167
168/*
169 * Exception vectors.
170 */
171#ifdef CONFIG_PPC_BOOK3S
172#define START_EXCEPTION(n, label) \
173 __HEAD; \
174 . = n; \
175 DO_KVM n; \
176label:
177
178#else
179#define START_EXCEPTION(n, label) \
180 __HEAD; \
181 . = n; \
182label:
183
184#endif
185
186#define EXCEPTION(n, label, hdlr) \
187 START_EXCEPTION(n, label) \
188 EXCEPTION_PROLOG n label; \
189 prepare_transfer_to_handler; \
190 bl hdlr; \
191 b interrupt_return
192
193.macro vmap_stack_overflow_exception
194 __HEAD
195vmap_stack_overflow:
196#ifdef CONFIG_SMP
197 mfspr r1, SPRN_SPRG_THREAD
198 lwz r1, TASK_CPU - THREAD(r1)
199 slwi r1, r1, 3
200 addis r1, r1, emergency_ctx-PAGE_OFFSET@ha
201#else
202 lis r1, emergency_ctx-PAGE_OFFSET@ha
203#endif
204 lwz r1, emergency_ctx-PAGE_OFFSET@l(r1)
205 addi r1, r1, THREAD_SIZE - INT_FRAME_SIZE
206 EXCEPTION_PROLOG_2 0 vmap_stack_overflow
207 prepare_transfer_to_handler
208 bl stack_overflow_exception
209 b interrupt_return
210.endm
211
212#endif /* __HEAD_32_H__ */
213

source code of linux/arch/powerpc/kernel/head_32.h