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powerpc: Remove use of a second scratch SPRG in STAB code
[linux-2.6/next.git] / arch / powerpc / include / asm / exception-64s.h
bloba98653b262312c6b3ca73b92089e7391e61527c2
1 #ifndef _ASM_POWERPC_EXCEPTION_H
2 #define _ASM_POWERPC_EXCEPTION_H
3 /*
4 * Extracted from head_64.S
5 *
6 * PowerPC version
7 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
8 *
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.
15 *
16 * Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
17 * Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
18 *
19 * This file contains the low-level support and setup for the
20 * PowerPC-64 platform, including trap and interrupt dispatch.
21 *
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.
26 */
27 /*
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.
32 *
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.
36 */
37
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
49
50 /*
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.
55 */
56 #define LOAD_HANDLER(reg, label) \
57 addi reg,reg,(label)-_stext; /* virt addr of handler ... */
58
59 #define EXCEPTION_PROLOG_1(area) \
60 mfspr r13,SPRN_SPRG_PACA; /* get paca address into r13 */ \
61 std r9,area+EX_R9(r13); /* save r9 - r12 */ \
62 std r10,area+EX_R10(r13); \
63 std r11,area+EX_R11(r13); \
64 std r12,area+EX_R12(r13); \
65 mfspr r9,SPRN_SPRG_SCRATCH0; \
66 std r9,area+EX_R13(r13); \
67 mfcr r9
68
69 #define EXCEPTION_PROLOG_PSERIES_1(label) \
70 ld r12,PACAKBASE(r13); /* get high part of &label */ \
71 ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \
72 mfspr r11,SPRN_SRR0; /* save SRR0 */ \
73 LOAD_HANDLER(r12,label) \
74 mtspr SPRN_SRR0,r12; \
75 mfspr r12,SPRN_SRR1; /* and SRR1 */ \
76 mtspr SPRN_SRR1,r10; \
77 rfid; \
78 b . /* prevent speculative execution */
79
80 #define EXCEPTION_PROLOG_PSERIES(area, label) \
81 EXCEPTION_PROLOG_1(area); \
82 EXCEPTION_PROLOG_PSERIES_1(label);
83
84 /*
85 * The common exception prolog is used for all except a few exceptions
86 * such as a segment miss on a kernel address. We have to be prepared
87 * to take another exception from the point where we first touch the
88 * kernel stack onwards.
89 *
90 * On entry r13 points to the paca, r9-r13 are saved in the paca,
91 * r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
92 * SRR1, and relocation is on.
93 */
94 #define EXCEPTION_PROLOG_COMMON(n, area) \
95 andi. r10,r12,MSR_PR; /* See if coming from user */ \
96 mr r10,r1; /* Save r1 */ \
97 subi r1,r1,INT_FRAME_SIZE; /* alloc frame on kernel stack */ \
98 beq- 1f; \
99 ld r1,PACAKSAVE(r13); /* kernel stack to use */ \
100 1: cmpdi cr1,r1,0; /* check if r1 is in userspace */ \
101 bge- cr1,2f; /* abort if it is */ \
102 b 3f; \
103 2: li r1,(n); /* will be reloaded later */ \
104 sth r1,PACA_TRAP_SAVE(r13); \
105 b bad_stack; \
106 3: std r9,_CCR(r1); /* save CR in stackframe */ \
107 std r11,_NIP(r1); /* save SRR0 in stackframe */ \
108 std r12,_MSR(r1); /* save SRR1 in stackframe */ \
109 std r10,0(r1); /* make stack chain pointer */ \
110 std r0,GPR0(r1); /* save r0 in stackframe */ \
111 std r10,GPR1(r1); /* save r1 in stackframe */ \
112 ACCOUNT_CPU_USER_ENTRY(r9, r10); \
113 std r2,GPR2(r1); /* save r2 in stackframe */ \
114 SAVE_4GPRS(3, r1); /* save r3 - r6 in stackframe */ \
115 SAVE_2GPRS(7, r1); /* save r7, r8 in stackframe */ \
116 ld r9,area+EX_R9(r13); /* move r9, r10 to stackframe */ \
117 ld r10,area+EX_R10(r13); \
118 std r9,GPR9(r1); \
119 std r10,GPR10(r1); \
120 ld r9,area+EX_R11(r13); /* move r11 - r13 to stackframe */ \
121 ld r10,area+EX_R12(r13); \
122 ld r11,area+EX_R13(r13); \
123 std r9,GPR11(r1); \
124 std r10,GPR12(r1); \
125 std r11,GPR13(r1); \
126 ld r2,PACATOC(r13); /* get kernel TOC into r2 */ \
127 mflr r9; /* save LR in stackframe */ \
128 std r9,_LINK(r1); \
129 mfctr r10; /* save CTR in stackframe */ \
130 std r10,_CTR(r1); \
131 lbz r10,PACASOFTIRQEN(r13); \
132 mfspr r11,SPRN_XER; /* save XER in stackframe */ \
133 std r10,SOFTE(r1); \
134 std r11,_XER(r1); \
135 li r9,(n)+1; \
136 std r9,_TRAP(r1); /* set trap number */ \
137 li r10,0; \
138 ld r11,exception_marker@toc(r2); \
139 std r10,RESULT(r1); /* clear regs->result */ \
140 std r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame */
141
142 /*
143 * Exception vectors.
144 */
145 #define STD_EXCEPTION_PSERIES(n, label) \
146 . = n; \
147 .globl label##_pSeries; \
148 label##_pSeries: \
149 HMT_MEDIUM; \
150 mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
151 EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
152
153 #define HSTD_EXCEPTION_PSERIES(n, label) \
154 . = n; \
155 .globl label##_pSeries; \
156 label##_pSeries: \
157 HMT_MEDIUM; \
158 mtspr SPRN_SPRG_SCRATCH0,r20; /* save r20 */ \
159 mfspr r20,SPRN_HSRR0; /* copy HSRR0 to SRR0 */ \
160 mtspr SPRN_SRR0,r20; \
161 mfspr r20,SPRN_HSRR1; /* copy HSRR0 to SRR0 */ \
162 mtspr SPRN_SRR1,r20; \
163 mfspr r20,SPRN_SPRG_SCRATCH0; /* restore r20 */ \
164 mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
165 EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
166
167
168 #define MASKABLE_EXCEPTION_PSERIES(n, label) \
169 . = n; \
170 .globl label##_pSeries; \
171 label##_pSeries: \
172 HMT_MEDIUM; \
173 mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
174 mfspr r13,SPRN_SPRG_PACA; /* get paca address into r13 */ \
175 std r9,PACA_EXGEN+EX_R9(r13); /* save r9, r10 */ \
176 std r10,PACA_EXGEN+EX_R10(r13); \
177 lbz r10,PACASOFTIRQEN(r13); \
178 mfcr r9; \
179 cmpwi r10,0; \
180 beq masked_interrupt; \
181 mfspr r10,SPRN_SPRG_SCRATCH0; \
182 std r10,PACA_EXGEN+EX_R13(r13); \
183 std r11,PACA_EXGEN+EX_R11(r13); \
184 std r12,PACA_EXGEN+EX_R12(r13); \
185 ld r12,PACAKBASE(r13); /* get high part of &label */ \
186 ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \
187 mfspr r11,SPRN_SRR0; /* save SRR0 */ \
188 LOAD_HANDLER(r12,label##_common) \
189 mtspr SPRN_SRR0,r12; \
190 mfspr r12,SPRN_SRR1; /* and SRR1 */ \
191 mtspr SPRN_SRR1,r10; \
192 rfid; \
193 b . /* prevent speculative execution */
194
195 #ifdef CONFIG_PPC_ISERIES
196 #define DISABLE_INTS \
197 li r11,0; \
198 stb r11,PACASOFTIRQEN(r13); \
199 BEGIN_FW_FTR_SECTION; \
200 stb r11,PACAHARDIRQEN(r13); \
201 END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES); \
202 TRACE_DISABLE_INTS; \
203 BEGIN_FW_FTR_SECTION; \
204 mfmsr r10; \
205 ori r10,r10,MSR_EE; \
206 mtmsrd r10,1; \
207 END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
208 #else
209 #define DISABLE_INTS \
210 li r11,0; \
211 stb r11,PACASOFTIRQEN(r13); \
212 stb r11,PACAHARDIRQEN(r13); \
213 TRACE_DISABLE_INTS
214 #endif /* CONFIG_PPC_ISERIES */
215
216 #define ENABLE_INTS \
217 ld r12,_MSR(r1); \
218 mfmsr r11; \
219 rlwimi r11,r12,0,MSR_EE; \
220 mtmsrd r11,1
221
222 #define STD_EXCEPTION_COMMON(trap, label, hdlr) \
223 .align 7; \
224 .globl label##_common; \
225 label##_common: \
226 EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
227 DISABLE_INTS; \
228 bl .save_nvgprs; \
229 addi r3,r1,STACK_FRAME_OVERHEAD; \
230 bl hdlr; \
231 b .ret_from_except
232
233 /*
234 * Like STD_EXCEPTION_COMMON, but for exceptions that can occur
235 * in the idle task and therefore need the special idle handling.
236 */
237 #define STD_EXCEPTION_COMMON_IDLE(trap, label, hdlr) \
238 .align 7; \
239 .globl label##_common; \
240 label##_common: \
241 EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
242 FINISH_NAP; \
243 DISABLE_INTS; \
244 bl .save_nvgprs; \
245 addi r3,r1,STACK_FRAME_OVERHEAD; \
246 bl hdlr; \
247 b .ret_from_except
248
249 #define STD_EXCEPTION_COMMON_LITE(trap, label, hdlr) \
250 .align 7; \
251 .globl label##_common; \
252 label##_common: \
253 EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
254 FINISH_NAP; \
255 DISABLE_INTS; \
256 BEGIN_FTR_SECTION \
257 bl .ppc64_runlatch_on; \
258 END_FTR_SECTION_IFSET(CPU_FTR_CTRL) \
259 addi r3,r1,STACK_FRAME_OVERHEAD; \
260 bl hdlr; \
261 b .ret_from_except_lite
262
263 /*
264 * When the idle code in power4_idle puts the CPU into NAP mode,
265 * it has to do so in a loop, and relies on the external interrupt
266 * and decrementer interrupt entry code to get it out of the loop.
267 * It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
268 * to signal that it is in the loop and needs help to get out.
269 */
270 #ifdef CONFIG_PPC_970_NAP
271 #define FINISH_NAP \
272 BEGIN_FTR_SECTION \
273 clrrdi r11,r1,THREAD_SHIFT; \
274 ld r9,TI_LOCAL_FLAGS(r11); \
275 andi. r10,r9,_TLF_NAPPING; \
276 bnel power4_fixup_nap; \
277 END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
278 #else
279 #define FINISH_NAP
280 #endif
281
282 #endif /* _ASM_POWERPC_EXCEPTION_H */
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