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Linux 2.6.25-rc4
[linux-2.6/next.git] / arch / ppc / kernel / head_booke.h
blob166d597b6db247d75a5cc098a1e0bd8ec7d3fd2a
1 #ifndef __HEAD_BOOKE_H__
2 #define __HEAD_BOOKE_H__
3
4 /*
5 * Macros used for common Book-e exception handling
6 */
7
8 #define SET_IVOR(vector_number, vector_label) \
9 li r26,vector_label@l; \
10 mtspr SPRN_IVOR##vector_number,r26; \
11 sync
12
13 #define NORMAL_EXCEPTION_PROLOG \
14 mtspr SPRN_SPRG0,r10; /* save two registers to work with */\
15 mtspr SPRN_SPRG1,r11; \
16 mtspr SPRN_SPRG4W,r1; \
17 mfcr r10; /* save CR in r10 for now */\
18 mfspr r11,SPRN_SRR1; /* check whether user or kernel */\
19 andi. r11,r11,MSR_PR; \
20 beq 1f; \
21 mfspr r1,SPRN_SPRG3; /* if from user, start at top of */\
22 lwz r1,THREAD_INFO-THREAD(r1); /* this thread's kernel stack */\
23 addi r1,r1,THREAD_SIZE; \
24 1: subi r1,r1,INT_FRAME_SIZE; /* Allocate an exception frame */\
25 mr r11,r1; \
26 stw r10,_CCR(r11); /* save various registers */\
27 stw r12,GPR12(r11); \
28 stw r9,GPR9(r11); \
29 mfspr r10,SPRN_SPRG0; \
30 stw r10,GPR10(r11); \
31 mfspr r12,SPRN_SPRG1; \
32 stw r12,GPR11(r11); \
33 mflr r10; \
34 stw r10,_LINK(r11); \
35 mfspr r10,SPRN_SPRG4R; \
36 mfspr r12,SPRN_SRR0; \
37 stw r10,GPR1(r11); \
38 mfspr r9,SPRN_SRR1; \
39 stw r10,0(r11); \
40 rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
41 stw r0,GPR0(r11); \
42 SAVE_4GPRS(3, r11); \
43 SAVE_2GPRS(7, r11)
44
45 /* To handle the additional exception priority levels on 40x and Book-E
46 * processors we allocate a 4k stack per additional priority level. The various
47 * head_xxx.S files allocate space (exception_stack_top) for each priority's
48 * stack times the number of CPUs
49 *
50 * On 40x critical is the only additional level
51 * On 44x/e500 we have critical and machine check
52 * On e200 we have critical and debug (machine check occurs via critical)
53 *
54 * Additionally we reserve a SPRG for each priority level so we can free up a
55 * GPR to use as the base for indirect access to the exception stacks. This
56 * is necessary since the MMU is always on, for Book-E parts, and the stacks
57 * are offset from KERNELBASE.
58 *
59 */
60 #define BOOKE_EXCEPTION_STACK_SIZE (8192)
61
62 /* CRIT_SPRG only used in critical exception handling */
63 #define CRIT_SPRG SPRN_SPRG2
64 /* MCHECK_SPRG only used in machine check exception handling */
65 #define MCHECK_SPRG SPRN_SPRG6W
66
67 #define MCHECK_STACK_TOP (exception_stack_top - 4096)
68 #define CRIT_STACK_TOP (exception_stack_top)
69
70 /* only on e200 for now */
71 #define DEBUG_STACK_TOP (exception_stack_top - 4096)
72 #define DEBUG_SPRG SPRN_SPRG6W
73
74 #ifdef CONFIG_SMP
75 #define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
76 mfspr r8,SPRN_PIR; \
77 mulli r8,r8,BOOKE_EXCEPTION_STACK_SIZE; \
78 neg r8,r8; \
79 addis r8,r8,level##_STACK_TOP@ha; \
80 addi r8,r8,level##_STACK_TOP@l
81 #else
82 #define BOOKE_LOAD_EXC_LEVEL_STACK(level) \
83 lis r8,level##_STACK_TOP@h; \
84 ori r8,r8,level##_STACK_TOP@l
85 #endif
86
87 /*
88 * Exception prolog for critical/machine check exceptions. This is a
89 * little different from the normal exception prolog above since a
90 * critical/machine check exception can potentially occur at any point
91 * during normal exception processing. Thus we cannot use the same SPRG
92 * registers as the normal prolog above. Instead we use a portion of the
93 * critical/machine check exception stack at low physical addresses.
94 */
95 #define EXC_LEVEL_EXCEPTION_PROLOG(exc_level, exc_level_srr0, exc_level_srr1) \
96 mtspr exc_level##_SPRG,r8; \
97 BOOKE_LOAD_EXC_LEVEL_STACK(exc_level);/* r8 points to the exc_level stack*/ \
98 stw r10,GPR10-INT_FRAME_SIZE(r8); \
99 stw r11,GPR11-INT_FRAME_SIZE(r8); \
100 mfcr r10; /* save CR in r10 for now */\
101 mfspr r11,exc_level_srr1; /* check whether user or kernel */\
102 andi. r11,r11,MSR_PR; \
103 mr r11,r8; \
104 mfspr r8,exc_level##_SPRG; \
105 beq 1f; \
106 /* COMING FROM USER MODE */ \
107 mfspr r11,SPRN_SPRG3; /* if from user, start at top of */\
108 lwz r11,THREAD_INFO-THREAD(r11); /* this thread's kernel stack */\
109 addi r11,r11,THREAD_SIZE; \
110 1: subi r11,r11,INT_FRAME_SIZE; /* Allocate an exception frame */\
111 stw r10,_CCR(r11); /* save various registers */\
112 stw r12,GPR12(r11); \
113 stw r9,GPR9(r11); \
114 mflr r10; \
115 stw r10,_LINK(r11); \
116 mfspr r12,SPRN_DEAR; /* save DEAR and ESR in the frame */\
117 stw r12,_DEAR(r11); /* since they may have had stuff */\
118 mfspr r9,SPRN_ESR; /* in them at the point where the */\
119 stw r9,_ESR(r11); /* exception was taken */\
120 mfspr r12,exc_level_srr0; \
121 stw r1,GPR1(r11); \
122 mfspr r9,exc_level_srr1; \
123 stw r1,0(r11); \
124 mr r1,r11; \
125 rlwinm r9,r9,0,14,12; /* clear MSR_WE (necessary?) */\
126 stw r0,GPR0(r11); \
127 SAVE_4GPRS(3, r11); \
128 SAVE_2GPRS(7, r11)
129
130 #define CRITICAL_EXCEPTION_PROLOG \
131 EXC_LEVEL_EXCEPTION_PROLOG(CRIT, SPRN_CSRR0, SPRN_CSRR1)
132 #define DEBUG_EXCEPTION_PROLOG \
133 EXC_LEVEL_EXCEPTION_PROLOG(DEBUG, SPRN_DSRR0, SPRN_DSRR1)
134 #define MCHECK_EXCEPTION_PROLOG \
135 EXC_LEVEL_EXCEPTION_PROLOG(MCHECK, SPRN_MCSRR0, SPRN_MCSRR1)
136
137 /*
138 * Exception vectors.
139 */
140 #define START_EXCEPTION(label) \
141 .align 5; \
142 label:
143
144 #define FINISH_EXCEPTION(func) \
145 bl transfer_to_handler_full; \
146 .long func; \
147 .long ret_from_except_full
148
149 #define EXCEPTION(n, label, hdlr, xfer) \
150 START_EXCEPTION(label); \
151 NORMAL_EXCEPTION_PROLOG; \
152 addi r3,r1,STACK_FRAME_OVERHEAD; \
153 xfer(n, hdlr)
154
155 #define CRITICAL_EXCEPTION(n, label, hdlr) \
156 START_EXCEPTION(label); \
157 CRITICAL_EXCEPTION_PROLOG; \
158 addi r3,r1,STACK_FRAME_OVERHEAD; \
159 EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
160 NOCOPY, crit_transfer_to_handler, \
161 ret_from_crit_exc)
162
163 #define MCHECK_EXCEPTION(n, label, hdlr) \
164 START_EXCEPTION(label); \
165 MCHECK_EXCEPTION_PROLOG; \
166 mfspr r5,SPRN_ESR; \
167 stw r5,_ESR(r11); \
168 addi r3,r1,STACK_FRAME_OVERHEAD; \
169 EXC_XFER_TEMPLATE(hdlr, n+2, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), \
170 NOCOPY, mcheck_transfer_to_handler, \
171 ret_from_mcheck_exc)
172
173 #define EXC_XFER_TEMPLATE(hdlr, trap, msr, copyee, tfer, ret) \
174 li r10,trap; \
175 stw r10,TRAP(r11); \
176 lis r10,msr@h; \
177 ori r10,r10,msr@l; \
178 copyee(r10, r9); \
179 bl tfer; \
180 .long hdlr; \
181 .long ret
182
183 #define COPY_EE(d, s) rlwimi d,s,0,16,16
184 #define NOCOPY(d, s)
185
186 #define EXC_XFER_STD(n, hdlr) \
187 EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, NOCOPY, transfer_to_handler_full, \
188 ret_from_except_full)
189
190 #define EXC_XFER_LITE(n, hdlr) \
191 EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, NOCOPY, transfer_to_handler, \
192 ret_from_except)
193
194 #define EXC_XFER_EE(n, hdlr) \
195 EXC_XFER_TEMPLATE(hdlr, n, MSR_KERNEL, COPY_EE, transfer_to_handler_full, \
196 ret_from_except_full)
197
198 #define EXC_XFER_EE_LITE(n, hdlr) \
199 EXC_XFER_TEMPLATE(hdlr, n+1, MSR_KERNEL, COPY_EE, transfer_to_handler, \
200 ret_from_except)
201
202 /* Check for a single step debug exception while in an exception
203 * handler before state has been saved. This is to catch the case
204 * where an instruction that we are trying to single step causes
205 * an exception (eg ITLB/DTLB miss) and thus the first instruction of
206 * the exception handler generates a single step debug exception.
207 *
208 * If we get a debug trap on the first instruction of an exception handler,
209 * we reset the MSR_DE in the _exception handler's_ MSR (the debug trap is
210 * a critical exception, so we are using SPRN_CSRR1 to manipulate the MSR).
211 * The exception handler was handling a non-critical interrupt, so it will
212 * save (and later restore) the MSR via SPRN_CSRR1, which will still have
213 * the MSR_DE bit set.
214 */
215 #define DEBUG_EXCEPTION \
216 START_EXCEPTION(Debug); \
217 CRITICAL_EXCEPTION_PROLOG; \
218 \
219 /* \
220 * If there is a single step or branch-taken exception in an \
221 * exception entry sequence, it was probably meant to apply to \
222 * the code where the exception occurred (since exception entry \
223 * doesn't turn off DE automatically). We simulate the effect \
224 * of turning off DE on entry to an exception handler by turning \
225 * off DE in the CSRR1 value and clearing the debug status. \
226 */ \
227 mfspr r10,SPRN_DBSR; /* check single-step/branch taken */ \
228 andis. r10,r10,DBSR_IC@h; \
229 beq+ 2f; \
230 \
231 lis r10,KERNELBASE@h; /* check if exception in vectors */ \
232 ori r10,r10,KERNELBASE@l; \
233 cmplw r12,r10; \
234 blt+ 2f; /* addr below exception vectors */ \
235 \
236 lis r10,Debug@h; \
237 ori r10,r10,Debug@l; \
238 cmplw r12,r10; \
239 bgt+ 2f; /* addr above exception vectors */ \
240 \
241 /* here it looks like we got an inappropriate debug exception. */ \
242 1: rlwinm r9,r9,0,~MSR_DE; /* clear DE in the CSRR1 value */ \
243 lis r10,DBSR_IC@h; /* clear the IC event */ \
244 mtspr SPRN_DBSR,r10; \
245 /* restore state and get out */ \
246 lwz r10,_CCR(r11); \
247 lwz r0,GPR0(r11); \
248 lwz r1,GPR1(r11); \
249 mtcrf 0x80,r10; \
250 mtspr SPRN_CSRR0,r12; \
251 mtspr SPRN_CSRR1,r9; \
252 lwz r9,GPR9(r11); \
253 lwz r12,GPR12(r11); \
254 mtspr CRIT_SPRG,r8; \
255 BOOKE_LOAD_EXC_LEVEL_STACK(CRIT); /* r8 points to the debug stack */ \
256 lwz r10,GPR10-INT_FRAME_SIZE(r8); \
257 lwz r11,GPR11-INT_FRAME_SIZE(r8); \
258 mfspr r8,CRIT_SPRG; \
259 \
260 rfci; \
261 b .; \
262 \
263 /* continue normal handling for a critical exception... */ \
264 2: mfspr r4,SPRN_DBSR; \
265 addi r3,r1,STACK_FRAME_OVERHEAD; \
266 EXC_XFER_TEMPLATE(DebugException, 0x2002, (MSR_KERNEL & ~(MSR_ME|MSR_DE|MSR_CE)), NOCOPY, crit_transfer_to_handler, ret_from_crit_exc)
267
268 #define INSTRUCTION_STORAGE_EXCEPTION \
269 START_EXCEPTION(InstructionStorage) \
270 NORMAL_EXCEPTION_PROLOG; \
271 mfspr r5,SPRN_ESR; /* Grab the ESR and save it */ \
272 stw r5,_ESR(r11); \
273 mr r4,r12; /* Pass SRR0 as arg2 */ \
274 li r5,0; /* Pass zero as arg3 */ \
275 EXC_XFER_EE_LITE(0x0400, handle_page_fault)
276
277 #define ALIGNMENT_EXCEPTION \
278 START_EXCEPTION(Alignment) \
279 NORMAL_EXCEPTION_PROLOG; \
280 mfspr r4,SPRN_DEAR; /* Grab the DEAR and save it */ \
281 stw r4,_DEAR(r11); \
282 addi r3,r1,STACK_FRAME_OVERHEAD; \
283 EXC_XFER_EE(0x0600, alignment_exception)
284
285 #define PROGRAM_EXCEPTION \
286 START_EXCEPTION(Program) \
287 NORMAL_EXCEPTION_PROLOG; \
288 mfspr r4,SPRN_ESR; /* Grab the ESR and save it */ \
289 stw r4,_ESR(r11); \
290 addi r3,r1,STACK_FRAME_OVERHEAD; \
291 EXC_XFER_STD(0x0700, program_check_exception)
292
293 #define DECREMENTER_EXCEPTION \
294 START_EXCEPTION(Decrementer) \
295 NORMAL_EXCEPTION_PROLOG; \
296 lis r0,TSR_DIS@h; /* Setup the DEC interrupt mask */ \
297 mtspr SPRN_TSR,r0; /* Clear the DEC interrupt */ \
298 addi r3,r1,STACK_FRAME_OVERHEAD; \
299 EXC_XFER_LITE(0x0900, timer_interrupt)
300
301 #define FP_UNAVAILABLE_EXCEPTION \
302 START_EXCEPTION(FloatingPointUnavailable) \
303 NORMAL_EXCEPTION_PROLOG; \
304 bne load_up_fpu; /* if from user, just load it up */ \
305 addi r3,r1,STACK_FRAME_OVERHEAD; \
306 EXC_XFER_EE_LITE(0x800, kernel_fp_unavailable_exception)
307
308 #endif /* __HEAD_BOOKE_H__ */
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