i2c: Kerneldoc for most I/O calls
[linux-ginger.git] / include / asm-powerpc / exception.h
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1 #ifndef _ASM_POWERPC_EXCEPTION_H
2 #define _ASM_POWERPC_EXCEPTION_H
3 /*
4 * Extracted from head_64.S
6 * PowerPC version
7 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
9 * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
10 * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
11 * Adapted for Power Macintosh by Paul Mackerras.
12 * Low-level exception handlers and MMU support
13 * rewritten by Paul Mackerras.
14 * Copyright (C) 1996 Paul Mackerras.
16 * Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
17 * Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
19 * This file contains the low-level support and setup for the
20 * PowerPC-64 platform, including trap and interrupt dispatch.
22 * This program is free software; you can redistribute it and/or
23 * modify it under the terms of the GNU General Public License
24 * as published by the Free Software Foundation; either version
25 * 2 of the License, or (at your option) any later version.
28 * The following macros define the code that appears as
29 * the prologue to each of the exception handlers. They
30 * are split into two parts to allow a single kernel binary
31 * to be used for pSeries and iSeries.
33 * We make as much of the exception code common between native
34 * exception handlers (including pSeries LPAR) and iSeries LPAR
35 * implementations as possible.
38 #define EX_R9 0
39 #define EX_R10 8
40 #define EX_R11 16
41 #define EX_R12 24
42 #define EX_R13 32
43 #define EX_SRR0 40
44 #define EX_DAR 48
45 #define EX_DSISR 56
46 #define EX_CCR 60
47 #define EX_R3 64
48 #define EX_LR 72
51 * We're short on space and time in the exception prolog, so we can't
52 * use the normal SET_REG_IMMEDIATE macro. Normally we just need the
53 * low halfword of the address, but for Kdump we need the whole low
54 * word.
56 #ifdef CONFIG_CRASH_DUMP
57 #define LOAD_HANDLER(reg, label) \
58 oris reg,reg,(label)@h; /* virt addr of handler ... */ \
59 ori reg,reg,(label)@l; /* .. and the rest */
60 #else
61 #define LOAD_HANDLER(reg, label) \
62 ori reg,reg,(label)@l; /* virt addr of handler ... */
63 #endif
65 #define EXCEPTION_PROLOG_1(area) \
66 mfspr r13,SPRN_SPRG3; /* get paca address into r13 */ \
67 std r9,area+EX_R9(r13); /* save r9 - r12 */ \
68 std r10,area+EX_R10(r13); \
69 std r11,area+EX_R11(r13); \
70 std r12,area+EX_R12(r13); \
71 mfspr r9,SPRN_SPRG1; \
72 std r9,area+EX_R13(r13); \
73 mfcr r9
76 * Equal to EXCEPTION_PROLOG_PSERIES, except that it forces 64bit mode.
77 * The firmware calls the registered system_reset_fwnmi and
78 * machine_check_fwnmi handlers in 32bit mode if the cpu happens to run
79 * a 32bit application at the time of the event.
80 * This firmware bug is present on POWER4 and JS20.
82 #define EXCEPTION_PROLOG_PSERIES_FORCE_64BIT(area, label) \
83 EXCEPTION_PROLOG_1(area); \
84 clrrdi r12,r13,32; /* get high part of &label */ \
85 mfmsr r10; \
86 /* force 64bit mode */ \
87 li r11,5; /* MSR_SF_LG|MSR_ISF_LG */ \
88 rldimi r10,r11,61,0; /* insert into top 3 bits */ \
89 /* done 64bit mode */ \
90 mfspr r11,SPRN_SRR0; /* save SRR0 */ \
91 LOAD_HANDLER(r12,label) \
92 ori r10,r10,MSR_IR|MSR_DR|MSR_RI; \
93 mtspr SPRN_SRR0,r12; \
94 mfspr r12,SPRN_SRR1; /* and SRR1 */ \
95 mtspr SPRN_SRR1,r10; \
96 rfid; \
97 b . /* prevent speculative execution */
99 #define EXCEPTION_PROLOG_PSERIES(area, label) \
100 EXCEPTION_PROLOG_1(area); \
101 clrrdi r12,r13,32; /* get high part of &label */ \
102 mfmsr r10; \
103 mfspr r11,SPRN_SRR0; /* save SRR0 */ \
104 LOAD_HANDLER(r12,label) \
105 ori r10,r10,MSR_IR|MSR_DR|MSR_RI; \
106 mtspr SPRN_SRR0,r12; \
107 mfspr r12,SPRN_SRR1; /* and SRR1 */ \
108 mtspr SPRN_SRR1,r10; \
109 rfid; \
110 b . /* prevent speculative execution */
113 * The common exception prolog is used for all except a few exceptions
114 * such as a segment miss on a kernel address. We have to be prepared
115 * to take another exception from the point where we first touch the
116 * kernel stack onwards.
118 * On entry r13 points to the paca, r9-r13 are saved in the paca,
119 * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
120 * SRR1, and relocation is on.
122 #define EXCEPTION_PROLOG_COMMON(n, area) \
123 andi. r10,r12,MSR_PR; /* See if coming from user */ \
124 mr r10,r1; /* Save r1 */ \
125 subi r1,r1,INT_FRAME_SIZE; /* alloc frame on kernel stack */ \
126 beq- 1f; \
127 ld r1,PACAKSAVE(r13); /* kernel stack to use */ \
128 1: cmpdi cr1,r1,0; /* check if r1 is in userspace */ \
129 bge- cr1,2f; /* abort if it is */ \
130 b 3f; \
131 2: li r1,(n); /* will be reloaded later */ \
132 sth r1,PACA_TRAP_SAVE(r13); \
133 b bad_stack; \
134 3: std r9,_CCR(r1); /* save CR in stackframe */ \
135 std r11,_NIP(r1); /* save SRR0 in stackframe */ \
136 std r12,_MSR(r1); /* save SRR1 in stackframe */ \
137 std r10,0(r1); /* make stack chain pointer */ \
138 std r0,GPR0(r1); /* save r0 in stackframe */ \
139 std r10,GPR1(r1); /* save r1 in stackframe */ \
140 ACCOUNT_CPU_USER_ENTRY(r9, r10); \
141 std r2,GPR2(r1); /* save r2 in stackframe */ \
142 SAVE_4GPRS(3, r1); /* save r3 - r6 in stackframe */ \
143 SAVE_2GPRS(7, r1); /* save r7, r8 in stackframe */ \
144 ld r9,area+EX_R9(r13); /* move r9, r10 to stackframe */ \
145 ld r10,area+EX_R10(r13); \
146 std r9,GPR9(r1); \
147 std r10,GPR10(r1); \
148 ld r9,area+EX_R11(r13); /* move r11 - r13 to stackframe */ \
149 ld r10,area+EX_R12(r13); \
150 ld r11,area+EX_R13(r13); \
151 std r9,GPR11(r1); \
152 std r10,GPR12(r1); \
153 std r11,GPR13(r1); \
154 ld r2,PACATOC(r13); /* get kernel TOC into r2 */ \
155 mflr r9; /* save LR in stackframe */ \
156 std r9,_LINK(r1); \
157 mfctr r10; /* save CTR in stackframe */ \
158 std r10,_CTR(r1); \
159 lbz r10,PACASOFTIRQEN(r13); \
160 mfspr r11,SPRN_XER; /* save XER in stackframe */ \
161 std r10,SOFTE(r1); \
162 std r11,_XER(r1); \
163 li r9,(n)+1; \
164 std r9,_TRAP(r1); /* set trap number */ \
165 li r10,0; \
166 ld r11,exception_marker@toc(r2); \
167 std r10,RESULT(r1); /* clear regs->result */ \
168 std r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame */
171 * Exception vectors.
173 #define STD_EXCEPTION_PSERIES(n, label) \
174 . = n; \
175 .globl label##_pSeries; \
176 label##_pSeries: \
177 HMT_MEDIUM; \
178 mtspr SPRN_SPRG1,r13; /* save r13 */ \
179 EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
181 #define HSTD_EXCEPTION_PSERIES(n, label) \
182 . = n; \
183 .globl label##_pSeries; \
184 label##_pSeries: \
185 HMT_MEDIUM; \
186 mtspr SPRN_SPRG1,r20; /* save r20 */ \
187 mfspr r20,SPRN_HSRR0; /* copy HSRR0 to SRR0 */ \
188 mtspr SPRN_SRR0,r20; \
189 mfspr r20,SPRN_HSRR1; /* copy HSRR0 to SRR0 */ \
190 mtspr SPRN_SRR1,r20; \
191 mfspr r20,SPRN_SPRG1; /* restore r20 */ \
192 mtspr SPRN_SPRG1,r13; /* save r13 */ \
193 EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
196 #define MASKABLE_EXCEPTION_PSERIES(n, label) \
197 . = n; \
198 .globl label##_pSeries; \
199 label##_pSeries: \
200 HMT_MEDIUM; \
201 mtspr SPRN_SPRG1,r13; /* save r13 */ \
202 mfspr r13,SPRN_SPRG3; /* get paca address into r13 */ \
203 std r9,PACA_EXGEN+EX_R9(r13); /* save r9, r10 */ \
204 std r10,PACA_EXGEN+EX_R10(r13); \
205 lbz r10,PACASOFTIRQEN(r13); \
206 mfcr r9; \
207 cmpwi r10,0; \
208 beq masked_interrupt; \
209 mfspr r10,SPRN_SPRG1; \
210 std r10,PACA_EXGEN+EX_R13(r13); \
211 std r11,PACA_EXGEN+EX_R11(r13); \
212 std r12,PACA_EXGEN+EX_R12(r13); \
213 clrrdi r12,r13,32; /* get high part of &label */ \
214 mfmsr r10; \
215 mfspr r11,SPRN_SRR0; /* save SRR0 */ \
216 LOAD_HANDLER(r12,label##_common) \
217 ori r10,r10,MSR_IR|MSR_DR|MSR_RI; \
218 mtspr SPRN_SRR0,r12; \
219 mfspr r12,SPRN_SRR1; /* and SRR1 */ \
220 mtspr SPRN_SRR1,r10; \
221 rfid; \
222 b . /* prevent speculative execution */
224 #ifdef CONFIG_PPC_ISERIES
225 #define DISABLE_INTS \
226 li r11,0; \
227 stb r11,PACASOFTIRQEN(r13); \
228 BEGIN_FW_FTR_SECTION; \
229 stb r11,PACAHARDIRQEN(r13); \
230 END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES); \
231 TRACE_DISABLE_INTS; \
232 BEGIN_FW_FTR_SECTION; \
233 mfmsr r10; \
234 ori r10,r10,MSR_EE; \
235 mtmsrd r10,1; \
236 END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
237 #else
238 #define DISABLE_INTS \
239 li r11,0; \
240 stb r11,PACASOFTIRQEN(r13); \
241 stb r11,PACAHARDIRQEN(r13); \
242 TRACE_DISABLE_INTS
243 #endif /* CONFIG_PPC_ISERIES */
245 #define ENABLE_INTS \
246 ld r12,_MSR(r1); \
247 mfmsr r11; \
248 rlwimi r11,r12,0,MSR_EE; \
249 mtmsrd r11,1
251 #define STD_EXCEPTION_COMMON(trap, label, hdlr) \
252 .align 7; \
253 .globl label##_common; \
254 label##_common: \
255 EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
256 DISABLE_INTS; \
257 bl .save_nvgprs; \
258 addi r3,r1,STACK_FRAME_OVERHEAD; \
259 bl hdlr; \
260 b .ret_from_except
263 * Like STD_EXCEPTION_COMMON, but for exceptions that can occur
264 * in the idle task and therefore need the special idle handling.
266 #define STD_EXCEPTION_COMMON_IDLE(trap, label, hdlr) \
267 .align 7; \
268 .globl label##_common; \
269 label##_common: \
270 EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
271 FINISH_NAP; \
272 DISABLE_INTS; \
273 bl .save_nvgprs; \
274 addi r3,r1,STACK_FRAME_OVERHEAD; \
275 bl hdlr; \
276 b .ret_from_except
278 #define STD_EXCEPTION_COMMON_LITE(trap, label, hdlr) \
279 .align 7; \
280 .globl label##_common; \
281 label##_common: \
282 EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
283 FINISH_NAP; \
284 DISABLE_INTS; \
285 BEGIN_FTR_SECTION \
286 bl .ppc64_runlatch_on; \
287 END_FTR_SECTION_IFSET(CPU_FTR_CTRL) \
288 addi r3,r1,STACK_FRAME_OVERHEAD; \
289 bl hdlr; \
290 b .ret_from_except_lite
293 * When the idle code in power4_idle puts the CPU into NAP mode,
294 * it has to do so in a loop, and relies on the external interrupt
295 * and decrementer interrupt entry code to get it out of the loop.
296 * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
297 * to signal that it is in the loop and needs help to get out.
299 #ifdef CONFIG_PPC_970_NAP
300 #define FINISH_NAP \
301 BEGIN_FTR_SECTION \
302 clrrdi r11,r1,THREAD_SHIFT; \
303 ld r9,TI_LOCAL_FLAGS(r11); \
304 andi. r10,r9,_TLF_NAPPING; \
305 bnel power4_fixup_nap; \
306 END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
307 #else
308 #define FINISH_NAP
309 #endif
311 #endif /* _ASM_POWERPC_EXCEPTION_H */