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9994a338 PM |
1 | /* |
2 | * PowerPC version | |
3 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
4 | * Rewritten by Cort Dougan (cort@fsmlabs.com) for PReP | |
5 | * Copyright (C) 1996 Cort Dougan <cort@fsmlabs.com> | |
6 | * Adapted for Power Macintosh by Paul Mackerras. | |
7 | * Low-level exception handlers and MMU support | |
8 | * rewritten by Paul Mackerras. | |
9 | * Copyright (C) 1996 Paul Mackerras. | |
10 | * MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net). | |
11 | * | |
12 | * This file contains the system call entry code, context switch | |
13 | * code, and exception/interrupt return code for PowerPC. | |
14 | * | |
15 | * This program is free software; you can redistribute it and/or | |
16 | * modify it under the terms of the GNU General Public License | |
17 | * as published by the Free Software Foundation; either version | |
18 | * 2 of the License, or (at your option) any later version. | |
19 | * | |
20 | */ | |
21 | ||
9994a338 PM |
22 | #include <linux/errno.h> |
23 | #include <linux/sys.h> | |
24 | #include <linux/threads.h> | |
25 | #include <asm/reg.h> | |
26 | #include <asm/page.h> | |
27 | #include <asm/mmu.h> | |
28 | #include <asm/cputable.h> | |
29 | #include <asm/thread_info.h> | |
30 | #include <asm/ppc_asm.h> | |
31 | #include <asm/asm-offsets.h> | |
32 | #include <asm/unistd.h> | |
33 | ||
34 | #undef SHOW_SYSCALLS | |
35 | #undef SHOW_SYSCALLS_TASK | |
36 | ||
37 | /* | |
38 | * MSR_KERNEL is > 0x10000 on 4xx/Book-E since it include MSR_CE. | |
39 | */ | |
40 | #if MSR_KERNEL >= 0x10000 | |
41 | #define LOAD_MSR_KERNEL(r, x) lis r,(x)@h; ori r,r,(x)@l | |
42 | #else | |
43 | #define LOAD_MSR_KERNEL(r, x) li r,(x) | |
44 | #endif | |
45 | ||
46 | #ifdef CONFIG_BOOKE | |
47 | #include "head_booke.h" | |
48 | #define TRANSFER_TO_HANDLER_EXC_LEVEL(exc_level) \ | |
49 | mtspr exc_level##_SPRG,r8; \ | |
50 | BOOKE_LOAD_EXC_LEVEL_STACK(exc_level); \ | |
51 | lwz r0,GPR10-INT_FRAME_SIZE(r8); \ | |
52 | stw r0,GPR10(r11); \ | |
53 | lwz r0,GPR11-INT_FRAME_SIZE(r8); \ | |
54 | stw r0,GPR11(r11); \ | |
55 | mfspr r8,exc_level##_SPRG | |
56 | ||
57 | .globl mcheck_transfer_to_handler | |
58 | mcheck_transfer_to_handler: | |
59 | TRANSFER_TO_HANDLER_EXC_LEVEL(MCHECK) | |
60 | b transfer_to_handler_full | |
61 | ||
62 | .globl debug_transfer_to_handler | |
63 | debug_transfer_to_handler: | |
64 | TRANSFER_TO_HANDLER_EXC_LEVEL(DEBUG) | |
65 | b transfer_to_handler_full | |
66 | ||
67 | .globl crit_transfer_to_handler | |
68 | crit_transfer_to_handler: | |
69 | TRANSFER_TO_HANDLER_EXC_LEVEL(CRIT) | |
70 | /* fall through */ | |
71 | #endif | |
72 | ||
73 | #ifdef CONFIG_40x | |
74 | .globl crit_transfer_to_handler | |
75 | crit_transfer_to_handler: | |
76 | lwz r0,crit_r10@l(0) | |
77 | stw r0,GPR10(r11) | |
78 | lwz r0,crit_r11@l(0) | |
79 | stw r0,GPR11(r11) | |
80 | /* fall through */ | |
81 | #endif | |
82 | ||
83 | /* | |
84 | * This code finishes saving the registers to the exception frame | |
85 | * and jumps to the appropriate handler for the exception, turning | |
86 | * on address translation. | |
87 | * Note that we rely on the caller having set cr0.eq iff the exception | |
88 | * occurred in kernel mode (i.e. MSR:PR = 0). | |
89 | */ | |
90 | .globl transfer_to_handler_full | |
91 | transfer_to_handler_full: | |
92 | SAVE_NVGPRS(r11) | |
93 | /* fall through */ | |
94 | ||
95 | .globl transfer_to_handler | |
96 | transfer_to_handler: | |
97 | stw r2,GPR2(r11) | |
98 | stw r12,_NIP(r11) | |
99 | stw r9,_MSR(r11) | |
100 | andi. r2,r9,MSR_PR | |
101 | mfctr r12 | |
102 | mfspr r2,SPRN_XER | |
103 | stw r12,_CTR(r11) | |
104 | stw r2,_XER(r11) | |
105 | mfspr r12,SPRN_SPRG3 | |
106 | addi r2,r12,-THREAD | |
107 | tovirt(r2,r2) /* set r2 to current */ | |
108 | beq 2f /* if from user, fix up THREAD.regs */ | |
109 | addi r11,r1,STACK_FRAME_OVERHEAD | |
110 | stw r11,PT_REGS(r12) | |
111 | #if defined(CONFIG_40x) || defined(CONFIG_BOOKE) | |
112 | /* Check to see if the dbcr0 register is set up to debug. Use the | |
4eaddb4d | 113 | internal debug mode bit to do this. */ |
9994a338 | 114 | lwz r12,THREAD_DBCR0(r12) |
4eaddb4d | 115 | andis. r12,r12,DBCR0_IDM@h |
9994a338 PM |
116 | beq+ 3f |
117 | /* From user and task is ptraced - load up global dbcr0 */ | |
118 | li r12,-1 /* clear all pending debug events */ | |
119 | mtspr SPRN_DBSR,r12 | |
120 | lis r11,global_dbcr0@ha | |
121 | tophys(r11,r11) | |
122 | addi r11,r11,global_dbcr0@l | |
4eaddb4d KG |
123 | #ifdef CONFIG_SMP |
124 | rlwinm r9,r1,0,0,(31-THREAD_SHIFT) | |
125 | lwz r9,TI_CPU(r9) | |
126 | slwi r9,r9,3 | |
127 | add r11,r11,r9 | |
128 | #endif | |
9994a338 PM |
129 | lwz r12,0(r11) |
130 | mtspr SPRN_DBCR0,r12 | |
131 | lwz r12,4(r11) | |
132 | addi r12,r12,-1 | |
133 | stw r12,4(r11) | |
134 | #endif | |
135 | b 3f | |
f39224a8 | 136 | |
9994a338 PM |
137 | 2: /* if from kernel, check interrupted DOZE/NAP mode and |
138 | * check for stack overflow | |
139 | */ | |
85218827 KG |
140 | lwz r9,KSP_LIMIT(r12) |
141 | cmplw r1,r9 /* if r1 <= ksp_limit */ | |
f39224a8 PM |
142 | ble- stack_ovf /* then the kernel stack overflowed */ |
143 | 5: | |
9994a338 | 144 | #ifdef CONFIG_6xx |
85218827 | 145 | rlwinm r9,r1,0,0,31-THREAD_SHIFT |
f39224a8 PM |
146 | tophys(r9,r9) /* check local flags */ |
147 | lwz r12,TI_LOCAL_FLAGS(r9) | |
148 | mtcrf 0x01,r12 | |
149 | bt- 31-TLF_NAPPING,4f | |
9994a338 PM |
150 | #endif /* CONFIG_6xx */ |
151 | .globl transfer_to_handler_cont | |
152 | transfer_to_handler_cont: | |
9994a338 PM |
153 | 3: |
154 | mflr r9 | |
155 | lwz r11,0(r9) /* virtual address of handler */ | |
156 | lwz r9,4(r9) /* where to go when done */ | |
9994a338 PM |
157 | mtspr SPRN_SRR0,r11 |
158 | mtspr SPRN_SRR1,r10 | |
159 | mtlr r9 | |
160 | SYNC | |
161 | RFI /* jump to handler, enable MMU */ | |
162 | ||
f39224a8 PM |
163 | #ifdef CONFIG_6xx |
164 | 4: rlwinm r12,r12,0,~_TLF_NAPPING | |
165 | stw r12,TI_LOCAL_FLAGS(r9) | |
166 | b power_save_6xx_restore | |
a0652fc9 PM |
167 | #endif |
168 | ||
9994a338 PM |
169 | /* |
170 | * On kernel stack overflow, load up an initial stack pointer | |
171 | * and call StackOverflow(regs), which should not return. | |
172 | */ | |
173 | stack_ovf: | |
174 | /* sometimes we use a statically-allocated stack, which is OK. */ | |
f39224a8 PM |
175 | lis r12,_end@h |
176 | ori r12,r12,_end@l | |
177 | cmplw r1,r12 | |
178 | ble 5b /* r1 <= &_end is OK */ | |
9994a338 PM |
179 | SAVE_NVGPRS(r11) |
180 | addi r3,r1,STACK_FRAME_OVERHEAD | |
181 | lis r1,init_thread_union@ha | |
182 | addi r1,r1,init_thread_union@l | |
183 | addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD | |
184 | lis r9,StackOverflow@ha | |
185 | addi r9,r9,StackOverflow@l | |
186 | LOAD_MSR_KERNEL(r10,MSR_KERNEL) | |
187 | FIX_SRR1(r10,r12) | |
188 | mtspr SPRN_SRR0,r9 | |
189 | mtspr SPRN_SRR1,r10 | |
190 | SYNC | |
191 | RFI | |
192 | ||
193 | /* | |
194 | * Handle a system call. | |
195 | */ | |
196 | .stabs "arch/powerpc/kernel/",N_SO,0,0,0f | |
197 | .stabs "entry_32.S",N_SO,0,0,0f | |
198 | 0: | |
199 | ||
200 | _GLOBAL(DoSyscall) | |
9994a338 PM |
201 | stw r3,ORIG_GPR3(r1) |
202 | li r12,0 | |
203 | stw r12,RESULT(r1) | |
204 | lwz r11,_CCR(r1) /* Clear SO bit in CR */ | |
205 | rlwinm r11,r11,0,4,2 | |
206 | stw r11,_CCR(r1) | |
207 | #ifdef SHOW_SYSCALLS | |
208 | bl do_show_syscall | |
209 | #endif /* SHOW_SYSCALLS */ | |
6cb7bfeb | 210 | rlwinm r10,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */ |
9994a338 PM |
211 | lwz r11,TI_FLAGS(r10) |
212 | andi. r11,r11,_TIF_SYSCALL_T_OR_A | |
213 | bne- syscall_dotrace | |
214 | syscall_dotrace_cont: | |
215 | cmplwi 0,r0,NR_syscalls | |
216 | lis r10,sys_call_table@h | |
217 | ori r10,r10,sys_call_table@l | |
218 | slwi r0,r0,2 | |
219 | bge- 66f | |
220 | lwzx r10,r10,r0 /* Fetch system call handler [ptr] */ | |
221 | mtlr r10 | |
222 | addi r9,r1,STACK_FRAME_OVERHEAD | |
223 | PPC440EP_ERR42 | |
224 | blrl /* Call handler */ | |
225 | .globl ret_from_syscall | |
226 | ret_from_syscall: | |
227 | #ifdef SHOW_SYSCALLS | |
228 | bl do_show_syscall_exit | |
229 | #endif | |
230 | mr r6,r3 | |
6cb7bfeb | 231 | rlwinm r12,r1,0,0,(31-THREAD_SHIFT) /* current_thread_info() */ |
9994a338 | 232 | /* disable interrupts so current_thread_info()->flags can't change */ |
401d1f02 | 233 | LOAD_MSR_KERNEL(r10,MSR_KERNEL) /* doesn't include MSR_EE */ |
9994a338 PM |
234 | SYNC |
235 | MTMSRD(r10) | |
236 | lwz r9,TI_FLAGS(r12) | |
401d1f02 | 237 | li r8,-_LAST_ERRNO |
1bd79336 | 238 | andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) |
9994a338 | 239 | bne- syscall_exit_work |
401d1f02 DW |
240 | cmplw 0,r3,r8 |
241 | blt+ syscall_exit_cont | |
242 | lwz r11,_CCR(r1) /* Load CR */ | |
243 | neg r3,r3 | |
244 | oris r11,r11,0x1000 /* Set SO bit in CR */ | |
245 | stw r11,_CCR(r1) | |
9994a338 PM |
246 | syscall_exit_cont: |
247 | #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) | |
4eaddb4d KG |
248 | /* If the process has its own DBCR0 value, load it up. The internal |
249 | debug mode bit tells us that dbcr0 should be loaded. */ | |
9994a338 | 250 | lwz r0,THREAD+THREAD_DBCR0(r2) |
4eaddb4d | 251 | andis. r10,r0,DBCR0_IDM@h |
9994a338 PM |
252 | bnel- load_dbcr0 |
253 | #endif | |
b98ac05d BH |
254 | #ifdef CONFIG_44x |
255 | lis r4,icache_44x_need_flush@ha | |
256 | lwz r5,icache_44x_need_flush@l(r4) | |
257 | cmplwi cr0,r5,0 | |
258 | bne- 2f | |
259 | 1: | |
260 | #endif /* CONFIG_44x */ | |
b64f87c1 BB |
261 | BEGIN_FTR_SECTION |
262 | lwarx r7,0,r1 | |
263 | END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) | |
9994a338 PM |
264 | stwcx. r0,0,r1 /* to clear the reservation */ |
265 | lwz r4,_LINK(r1) | |
266 | lwz r5,_CCR(r1) | |
267 | mtlr r4 | |
268 | mtcr r5 | |
269 | lwz r7,_NIP(r1) | |
270 | lwz r8,_MSR(r1) | |
271 | FIX_SRR1(r8, r0) | |
272 | lwz r2,GPR2(r1) | |
273 | lwz r1,GPR1(r1) | |
274 | mtspr SPRN_SRR0,r7 | |
275 | mtspr SPRN_SRR1,r8 | |
276 | SYNC | |
277 | RFI | |
b98ac05d BH |
278 | #ifdef CONFIG_44x |
279 | 2: li r7,0 | |
280 | iccci r0,r0 | |
281 | stw r7,icache_44x_need_flush@l(r4) | |
282 | b 1b | |
283 | #endif /* CONFIG_44x */ | |
9994a338 PM |
284 | |
285 | 66: li r3,-ENOSYS | |
286 | b ret_from_syscall | |
287 | ||
288 | .globl ret_from_fork | |
289 | ret_from_fork: | |
290 | REST_NVGPRS(r1) | |
291 | bl schedule_tail | |
292 | li r3,0 | |
293 | b ret_from_syscall | |
294 | ||
295 | /* Traced system call support */ | |
296 | syscall_dotrace: | |
297 | SAVE_NVGPRS(r1) | |
298 | li r0,0xc00 | |
d73e0c99 | 299 | stw r0,_TRAP(r1) |
9994a338 PM |
300 | addi r3,r1,STACK_FRAME_OVERHEAD |
301 | bl do_syscall_trace_enter | |
302 | lwz r0,GPR0(r1) /* Restore original registers */ | |
303 | lwz r3,GPR3(r1) | |
304 | lwz r4,GPR4(r1) | |
305 | lwz r5,GPR5(r1) | |
306 | lwz r6,GPR6(r1) | |
307 | lwz r7,GPR7(r1) | |
308 | lwz r8,GPR8(r1) | |
309 | REST_NVGPRS(r1) | |
310 | b syscall_dotrace_cont | |
311 | ||
312 | syscall_exit_work: | |
401d1f02 | 313 | andi. r0,r9,_TIF_RESTOREALL |
1bd79336 PM |
314 | beq+ 0f |
315 | REST_NVGPRS(r1) | |
316 | b 2f | |
317 | 0: cmplw 0,r3,r8 | |
401d1f02 DW |
318 | blt+ 1f |
319 | andi. r0,r9,_TIF_NOERROR | |
320 | bne- 1f | |
321 | lwz r11,_CCR(r1) /* Load CR */ | |
322 | neg r3,r3 | |
323 | oris r11,r11,0x1000 /* Set SO bit in CR */ | |
324 | stw r11,_CCR(r1) | |
325 | ||
326 | 1: stw r6,RESULT(r1) /* Save result */ | |
9994a338 | 327 | stw r3,GPR3(r1) /* Update return value */ |
401d1f02 DW |
328 | 2: andi. r0,r9,(_TIF_PERSYSCALL_MASK) |
329 | beq 4f | |
330 | ||
1bd79336 | 331 | /* Clear per-syscall TIF flags if any are set. */ |
401d1f02 DW |
332 | |
333 | li r11,_TIF_PERSYSCALL_MASK | |
334 | addi r12,r12,TI_FLAGS | |
335 | 3: lwarx r8,0,r12 | |
336 | andc r8,r8,r11 | |
337 | #ifdef CONFIG_IBM405_ERR77 | |
338 | dcbt 0,r12 | |
339 | #endif | |
340 | stwcx. r8,0,r12 | |
341 | bne- 3b | |
342 | subi r12,r12,TI_FLAGS | |
343 | ||
344 | 4: /* Anything which requires enabling interrupts? */ | |
1bd79336 PM |
345 | andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP) |
346 | beq ret_from_except | |
347 | ||
348 | /* Re-enable interrupts */ | |
349 | ori r10,r10,MSR_EE | |
350 | SYNC | |
351 | MTMSRD(r10) | |
401d1f02 DW |
352 | |
353 | /* Save NVGPRS if they're not saved already */ | |
d73e0c99 | 354 | lwz r4,_TRAP(r1) |
9994a338 | 355 | andi. r4,r4,1 |
401d1f02 | 356 | beq 5f |
9994a338 PM |
357 | SAVE_NVGPRS(r1) |
358 | li r4,0xc00 | |
d73e0c99 | 359 | stw r4,_TRAP(r1) |
1bd79336 | 360 | 5: |
9994a338 PM |
361 | addi r3,r1,STACK_FRAME_OVERHEAD |
362 | bl do_syscall_trace_leave | |
1bd79336 | 363 | b ret_from_except_full |
9994a338 PM |
364 | |
365 | #ifdef SHOW_SYSCALLS | |
366 | do_show_syscall: | |
367 | #ifdef SHOW_SYSCALLS_TASK | |
368 | lis r11,show_syscalls_task@ha | |
369 | lwz r11,show_syscalls_task@l(r11) | |
370 | cmp 0,r2,r11 | |
371 | bnelr | |
372 | #endif | |
373 | stw r31,GPR31(r1) | |
374 | mflr r31 | |
375 | lis r3,7f@ha | |
376 | addi r3,r3,7f@l | |
377 | lwz r4,GPR0(r1) | |
378 | lwz r5,GPR3(r1) | |
379 | lwz r6,GPR4(r1) | |
380 | lwz r7,GPR5(r1) | |
381 | lwz r8,GPR6(r1) | |
382 | lwz r9,GPR7(r1) | |
383 | bl printk | |
384 | lis r3,77f@ha | |
385 | addi r3,r3,77f@l | |
386 | lwz r4,GPR8(r1) | |
387 | mr r5,r2 | |
388 | bl printk | |
389 | lwz r0,GPR0(r1) | |
390 | lwz r3,GPR3(r1) | |
391 | lwz r4,GPR4(r1) | |
392 | lwz r5,GPR5(r1) | |
393 | lwz r6,GPR6(r1) | |
394 | lwz r7,GPR7(r1) | |
395 | lwz r8,GPR8(r1) | |
396 | mtlr r31 | |
397 | lwz r31,GPR31(r1) | |
398 | blr | |
399 | ||
400 | do_show_syscall_exit: | |
401 | #ifdef SHOW_SYSCALLS_TASK | |
402 | lis r11,show_syscalls_task@ha | |
403 | lwz r11,show_syscalls_task@l(r11) | |
404 | cmp 0,r2,r11 | |
405 | bnelr | |
406 | #endif | |
407 | stw r31,GPR31(r1) | |
408 | mflr r31 | |
409 | stw r3,RESULT(r1) /* Save result */ | |
410 | mr r4,r3 | |
411 | lis r3,79f@ha | |
412 | addi r3,r3,79f@l | |
413 | bl printk | |
414 | lwz r3,RESULT(r1) | |
415 | mtlr r31 | |
416 | lwz r31,GPR31(r1) | |
417 | blr | |
418 | ||
419 | 7: .string "syscall %d(%x, %x, %x, %x, %x, " | |
420 | 77: .string "%x), current=%p\n" | |
421 | 79: .string " -> %x\n" | |
422 | .align 2,0 | |
423 | ||
424 | #ifdef SHOW_SYSCALLS_TASK | |
425 | .data | |
426 | .globl show_syscalls_task | |
427 | show_syscalls_task: | |
428 | .long -1 | |
429 | .text | |
430 | #endif | |
431 | #endif /* SHOW_SYSCALLS */ | |
432 | ||
433 | /* | |
401d1f02 DW |
434 | * The fork/clone functions need to copy the full register set into |
435 | * the child process. Therefore we need to save all the nonvolatile | |
436 | * registers (r13 - r31) before calling the C code. | |
9994a338 | 437 | */ |
9994a338 PM |
438 | .globl ppc_fork |
439 | ppc_fork: | |
440 | SAVE_NVGPRS(r1) | |
d73e0c99 | 441 | lwz r0,_TRAP(r1) |
9994a338 | 442 | rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */ |
d73e0c99 | 443 | stw r0,_TRAP(r1) /* register set saved */ |
9994a338 PM |
444 | b sys_fork |
445 | ||
446 | .globl ppc_vfork | |
447 | ppc_vfork: | |
448 | SAVE_NVGPRS(r1) | |
d73e0c99 | 449 | lwz r0,_TRAP(r1) |
9994a338 | 450 | rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */ |
d73e0c99 | 451 | stw r0,_TRAP(r1) /* register set saved */ |
9994a338 PM |
452 | b sys_vfork |
453 | ||
454 | .globl ppc_clone | |
455 | ppc_clone: | |
456 | SAVE_NVGPRS(r1) | |
d73e0c99 | 457 | lwz r0,_TRAP(r1) |
9994a338 | 458 | rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */ |
d73e0c99 | 459 | stw r0,_TRAP(r1) /* register set saved */ |
9994a338 PM |
460 | b sys_clone |
461 | ||
1bd79336 PM |
462 | .globl ppc_swapcontext |
463 | ppc_swapcontext: | |
464 | SAVE_NVGPRS(r1) | |
465 | lwz r0,_TRAP(r1) | |
466 | rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */ | |
467 | stw r0,_TRAP(r1) /* register set saved */ | |
468 | b sys_swapcontext | |
469 | ||
9994a338 PM |
470 | /* |
471 | * Top-level page fault handling. | |
472 | * This is in assembler because if do_page_fault tells us that | |
473 | * it is a bad kernel page fault, we want to save the non-volatile | |
474 | * registers before calling bad_page_fault. | |
475 | */ | |
476 | .globl handle_page_fault | |
477 | handle_page_fault: | |
478 | stw r4,_DAR(r1) | |
479 | addi r3,r1,STACK_FRAME_OVERHEAD | |
480 | bl do_page_fault | |
481 | cmpwi r3,0 | |
482 | beq+ ret_from_except | |
483 | SAVE_NVGPRS(r1) | |
d73e0c99 | 484 | lwz r0,_TRAP(r1) |
9994a338 | 485 | clrrwi r0,r0,1 |
d73e0c99 | 486 | stw r0,_TRAP(r1) |
9994a338 PM |
487 | mr r5,r3 |
488 | addi r3,r1,STACK_FRAME_OVERHEAD | |
489 | lwz r4,_DAR(r1) | |
490 | bl bad_page_fault | |
491 | b ret_from_except_full | |
492 | ||
493 | /* | |
494 | * This routine switches between two different tasks. The process | |
495 | * state of one is saved on its kernel stack. Then the state | |
496 | * of the other is restored from its kernel stack. The memory | |
497 | * management hardware is updated to the second process's state. | |
498 | * Finally, we can return to the second process. | |
499 | * On entry, r3 points to the THREAD for the current task, r4 | |
500 | * points to the THREAD for the new task. | |
501 | * | |
502 | * This routine is always called with interrupts disabled. | |
503 | * | |
504 | * Note: there are two ways to get to the "going out" portion | |
505 | * of this code; either by coming in via the entry (_switch) | |
506 | * or via "fork" which must set up an environment equivalent | |
507 | * to the "_switch" path. If you change this , you'll have to | |
508 | * change the fork code also. | |
509 | * | |
510 | * The code which creates the new task context is in 'copy_thread' | |
511 | * in arch/ppc/kernel/process.c | |
512 | */ | |
513 | _GLOBAL(_switch) | |
514 | stwu r1,-INT_FRAME_SIZE(r1) | |
515 | mflr r0 | |
516 | stw r0,INT_FRAME_SIZE+4(r1) | |
517 | /* r3-r12 are caller saved -- Cort */ | |
518 | SAVE_NVGPRS(r1) | |
519 | stw r0,_NIP(r1) /* Return to switch caller */ | |
520 | mfmsr r11 | |
521 | li r0,MSR_FP /* Disable floating-point */ | |
522 | #ifdef CONFIG_ALTIVEC | |
523 | BEGIN_FTR_SECTION | |
524 | oris r0,r0,MSR_VEC@h /* Disable altivec */ | |
525 | mfspr r12,SPRN_VRSAVE /* save vrsave register value */ | |
526 | stw r12,THREAD+THREAD_VRSAVE(r2) | |
527 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) | |
528 | #endif /* CONFIG_ALTIVEC */ | |
529 | #ifdef CONFIG_SPE | |
5e14d21e | 530 | BEGIN_FTR_SECTION |
9994a338 PM |
531 | oris r0,r0,MSR_SPE@h /* Disable SPE */ |
532 | mfspr r12,SPRN_SPEFSCR /* save spefscr register value */ | |
533 | stw r12,THREAD+THREAD_SPEFSCR(r2) | |
5e14d21e | 534 | END_FTR_SECTION_IFSET(CPU_FTR_SPE) |
9994a338 PM |
535 | #endif /* CONFIG_SPE */ |
536 | and. r0,r0,r11 /* FP or altivec or SPE enabled? */ | |
537 | beq+ 1f | |
538 | andc r11,r11,r0 | |
539 | MTMSRD(r11) | |
540 | isync | |
541 | 1: stw r11,_MSR(r1) | |
542 | mfcr r10 | |
543 | stw r10,_CCR(r1) | |
544 | stw r1,KSP(r3) /* Set old stack pointer */ | |
545 | ||
546 | #ifdef CONFIG_SMP | |
547 | /* We need a sync somewhere here to make sure that if the | |
548 | * previous task gets rescheduled on another CPU, it sees all | |
549 | * stores it has performed on this one. | |
550 | */ | |
551 | sync | |
552 | #endif /* CONFIG_SMP */ | |
553 | ||
554 | tophys(r0,r4) | |
555 | CLR_TOP32(r0) | |
556 | mtspr SPRN_SPRG3,r0 /* Update current THREAD phys addr */ | |
557 | lwz r1,KSP(r4) /* Load new stack pointer */ | |
558 | ||
559 | /* save the old current 'last' for return value */ | |
560 | mr r3,r2 | |
561 | addi r2,r4,-THREAD /* Update current */ | |
562 | ||
563 | #ifdef CONFIG_ALTIVEC | |
564 | BEGIN_FTR_SECTION | |
565 | lwz r0,THREAD+THREAD_VRSAVE(r2) | |
566 | mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */ | |
567 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) | |
568 | #endif /* CONFIG_ALTIVEC */ | |
569 | #ifdef CONFIG_SPE | |
5e14d21e | 570 | BEGIN_FTR_SECTION |
9994a338 PM |
571 | lwz r0,THREAD+THREAD_SPEFSCR(r2) |
572 | mtspr SPRN_SPEFSCR,r0 /* restore SPEFSCR reg */ | |
5e14d21e | 573 | END_FTR_SECTION_IFSET(CPU_FTR_SPE) |
9994a338 PM |
574 | #endif /* CONFIG_SPE */ |
575 | ||
576 | lwz r0,_CCR(r1) | |
577 | mtcrf 0xFF,r0 | |
578 | /* r3-r12 are destroyed -- Cort */ | |
579 | REST_NVGPRS(r1) | |
580 | ||
581 | lwz r4,_NIP(r1) /* Return to _switch caller in new task */ | |
582 | mtlr r4 | |
583 | addi r1,r1,INT_FRAME_SIZE | |
584 | blr | |
585 | ||
586 | .globl fast_exception_return | |
587 | fast_exception_return: | |
588 | #if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE)) | |
589 | andi. r10,r9,MSR_RI /* check for recoverable interrupt */ | |
590 | beq 1f /* if not, we've got problems */ | |
591 | #endif | |
592 | ||
593 | 2: REST_4GPRS(3, r11) | |
594 | lwz r10,_CCR(r11) | |
595 | REST_GPR(1, r11) | |
596 | mtcr r10 | |
597 | lwz r10,_LINK(r11) | |
598 | mtlr r10 | |
599 | REST_GPR(10, r11) | |
600 | mtspr SPRN_SRR1,r9 | |
601 | mtspr SPRN_SRR0,r12 | |
602 | REST_GPR(9, r11) | |
603 | REST_GPR(12, r11) | |
604 | lwz r11,GPR11(r11) | |
605 | SYNC | |
606 | RFI | |
607 | ||
608 | #if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE)) | |
609 | /* check if the exception happened in a restartable section */ | |
610 | 1: lis r3,exc_exit_restart_end@ha | |
611 | addi r3,r3,exc_exit_restart_end@l | |
612 | cmplw r12,r3 | |
613 | bge 3f | |
614 | lis r4,exc_exit_restart@ha | |
615 | addi r4,r4,exc_exit_restart@l | |
616 | cmplw r12,r4 | |
617 | blt 3f | |
618 | lis r3,fee_restarts@ha | |
619 | tophys(r3,r3) | |
620 | lwz r5,fee_restarts@l(r3) | |
621 | addi r5,r5,1 | |
622 | stw r5,fee_restarts@l(r3) | |
623 | mr r12,r4 /* restart at exc_exit_restart */ | |
624 | b 2b | |
625 | ||
991eb43a KG |
626 | .section .bss |
627 | .align 2 | |
628 | fee_restarts: | |
629 | .space 4 | |
630 | .previous | |
9994a338 PM |
631 | |
632 | /* aargh, a nonrecoverable interrupt, panic */ | |
633 | /* aargh, we don't know which trap this is */ | |
634 | /* but the 601 doesn't implement the RI bit, so assume it's OK */ | |
635 | 3: | |
636 | BEGIN_FTR_SECTION | |
637 | b 2b | |
638 | END_FTR_SECTION_IFSET(CPU_FTR_601) | |
639 | li r10,-1 | |
d73e0c99 | 640 | stw r10,_TRAP(r11) |
9994a338 PM |
641 | addi r3,r1,STACK_FRAME_OVERHEAD |
642 | lis r10,MSR_KERNEL@h | |
643 | ori r10,r10,MSR_KERNEL@l | |
644 | bl transfer_to_handler_full | |
645 | .long nonrecoverable_exception | |
646 | .long ret_from_except | |
647 | #endif | |
648 | ||
9994a338 PM |
649 | .globl ret_from_except_full |
650 | ret_from_except_full: | |
651 | REST_NVGPRS(r1) | |
652 | /* fall through */ | |
653 | ||
654 | .globl ret_from_except | |
655 | ret_from_except: | |
656 | /* Hard-disable interrupts so that current_thread_info()->flags | |
657 | * can't change between when we test it and when we return | |
658 | * from the interrupt. */ | |
659 | LOAD_MSR_KERNEL(r10,MSR_KERNEL) | |
660 | SYNC /* Some chip revs have problems here... */ | |
661 | MTMSRD(r10) /* disable interrupts */ | |
662 | ||
663 | lwz r3,_MSR(r1) /* Returning to user mode? */ | |
664 | andi. r0,r3,MSR_PR | |
665 | beq resume_kernel | |
666 | ||
667 | user_exc_return: /* r10 contains MSR_KERNEL here */ | |
668 | /* Check current_thread_info()->flags */ | |
6cb7bfeb | 669 | rlwinm r9,r1,0,0,(31-THREAD_SHIFT) |
9994a338 | 670 | lwz r9,TI_FLAGS(r9) |
1bd79336 | 671 | andi. r0,r9,(_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK|_TIF_NEED_RESCHED) |
9994a338 PM |
672 | bne do_work |
673 | ||
674 | restore_user: | |
675 | #if defined(CONFIG_4xx) || defined(CONFIG_BOOKE) | |
4eaddb4d KG |
676 | /* Check whether this process has its own DBCR0 value. The internal |
677 | debug mode bit tells us that dbcr0 should be loaded. */ | |
9994a338 | 678 | lwz r0,THREAD+THREAD_DBCR0(r2) |
4eaddb4d | 679 | andis. r10,r0,DBCR0_IDM@h |
9994a338 PM |
680 | bnel- load_dbcr0 |
681 | #endif | |
682 | ||
683 | #ifdef CONFIG_PREEMPT | |
684 | b restore | |
685 | ||
686 | /* N.B. the only way to get here is from the beq following ret_from_except. */ | |
687 | resume_kernel: | |
688 | /* check current_thread_info->preempt_count */ | |
6cb7bfeb | 689 | rlwinm r9,r1,0,0,(31-THREAD_SHIFT) |
9994a338 PM |
690 | lwz r0,TI_PREEMPT(r9) |
691 | cmpwi 0,r0,0 /* if non-zero, just restore regs and return */ | |
692 | bne restore | |
693 | lwz r0,TI_FLAGS(r9) | |
694 | andi. r0,r0,_TIF_NEED_RESCHED | |
695 | beq+ restore | |
696 | andi. r0,r3,MSR_EE /* interrupts off? */ | |
697 | beq restore /* don't schedule if so */ | |
698 | 1: bl preempt_schedule_irq | |
6cb7bfeb | 699 | rlwinm r9,r1,0,0,(31-THREAD_SHIFT) |
9994a338 PM |
700 | lwz r3,TI_FLAGS(r9) |
701 | andi. r0,r3,_TIF_NEED_RESCHED | |
702 | bne- 1b | |
703 | #else | |
704 | resume_kernel: | |
705 | #endif /* CONFIG_PREEMPT */ | |
706 | ||
707 | /* interrupts are hard-disabled at this point */ | |
708 | restore: | |
b98ac05d BH |
709 | #ifdef CONFIG_44x |
710 | lis r4,icache_44x_need_flush@ha | |
711 | lwz r5,icache_44x_need_flush@l(r4) | |
712 | cmplwi cr0,r5,0 | |
713 | beq+ 1f | |
714 | li r6,0 | |
715 | iccci r0,r0 | |
716 | stw r6,icache_44x_need_flush@l(r4) | |
717 | 1: | |
718 | #endif /* CONFIG_44x */ | |
9994a338 PM |
719 | lwz r0,GPR0(r1) |
720 | lwz r2,GPR2(r1) | |
721 | REST_4GPRS(3, r1) | |
722 | REST_2GPRS(7, r1) | |
723 | ||
724 | lwz r10,_XER(r1) | |
725 | lwz r11,_CTR(r1) | |
726 | mtspr SPRN_XER,r10 | |
727 | mtctr r11 | |
728 | ||
729 | PPC405_ERR77(0,r1) | |
b64f87c1 BB |
730 | BEGIN_FTR_SECTION |
731 | lwarx r11,0,r1 | |
732 | END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX) | |
9994a338 PM |
733 | stwcx. r0,0,r1 /* to clear the reservation */ |
734 | ||
735 | #if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE)) | |
736 | lwz r9,_MSR(r1) | |
737 | andi. r10,r9,MSR_RI /* check if this exception occurred */ | |
738 | beql nonrecoverable /* at a bad place (MSR:RI = 0) */ | |
739 | ||
740 | lwz r10,_CCR(r1) | |
741 | lwz r11,_LINK(r1) | |
742 | mtcrf 0xFF,r10 | |
743 | mtlr r11 | |
744 | ||
745 | /* | |
746 | * Once we put values in SRR0 and SRR1, we are in a state | |
747 | * where exceptions are not recoverable, since taking an | |
748 | * exception will trash SRR0 and SRR1. Therefore we clear the | |
749 | * MSR:RI bit to indicate this. If we do take an exception, | |
750 | * we can't return to the point of the exception but we | |
751 | * can restart the exception exit path at the label | |
752 | * exc_exit_restart below. -- paulus | |
753 | */ | |
754 | LOAD_MSR_KERNEL(r10,MSR_KERNEL & ~MSR_RI) | |
755 | SYNC | |
756 | MTMSRD(r10) /* clear the RI bit */ | |
757 | .globl exc_exit_restart | |
758 | exc_exit_restart: | |
759 | lwz r9,_MSR(r1) | |
760 | lwz r12,_NIP(r1) | |
761 | FIX_SRR1(r9,r10) | |
762 | mtspr SPRN_SRR0,r12 | |
763 | mtspr SPRN_SRR1,r9 | |
764 | REST_4GPRS(9, r1) | |
765 | lwz r1,GPR1(r1) | |
766 | .globl exc_exit_restart_end | |
767 | exc_exit_restart_end: | |
768 | SYNC | |
769 | RFI | |
770 | ||
771 | #else /* !(CONFIG_4xx || CONFIG_BOOKE) */ | |
772 | /* | |
773 | * This is a bit different on 4xx/Book-E because it doesn't have | |
774 | * the RI bit in the MSR. | |
775 | * The TLB miss handler checks if we have interrupted | |
776 | * the exception exit path and restarts it if so | |
777 | * (well maybe one day it will... :). | |
778 | */ | |
779 | lwz r11,_LINK(r1) | |
780 | mtlr r11 | |
781 | lwz r10,_CCR(r1) | |
782 | mtcrf 0xff,r10 | |
783 | REST_2GPRS(9, r1) | |
784 | .globl exc_exit_restart | |
785 | exc_exit_restart: | |
786 | lwz r11,_NIP(r1) | |
787 | lwz r12,_MSR(r1) | |
788 | exc_exit_start: | |
789 | mtspr SPRN_SRR0,r11 | |
790 | mtspr SPRN_SRR1,r12 | |
791 | REST_2GPRS(11, r1) | |
792 | lwz r1,GPR1(r1) | |
793 | .globl exc_exit_restart_end | |
794 | exc_exit_restart_end: | |
795 | PPC405_ERR77_SYNC | |
796 | rfi | |
797 | b . /* prevent prefetch past rfi */ | |
798 | ||
799 | /* | |
800 | * Returning from a critical interrupt in user mode doesn't need | |
801 | * to be any different from a normal exception. For a critical | |
802 | * interrupt in the kernel, we just return (without checking for | |
803 | * preemption) since the interrupt may have happened at some crucial | |
804 | * place (e.g. inside the TLB miss handler), and because we will be | |
805 | * running with r1 pointing into critical_stack, not the current | |
806 | * process's kernel stack (and therefore current_thread_info() will | |
807 | * give the wrong answer). | |
808 | * We have to restore various SPRs that may have been in use at the | |
809 | * time of the critical interrupt. | |
810 | * | |
811 | */ | |
812 | #ifdef CONFIG_40x | |
813 | #define PPC_40x_TURN_OFF_MSR_DR \ | |
814 | /* avoid any possible TLB misses here by turning off MSR.DR, we \ | |
815 | * assume the instructions here are mapped by a pinned TLB entry */ \ | |
816 | li r10,MSR_IR; \ | |
817 | mtmsr r10; \ | |
818 | isync; \ | |
819 | tophys(r1, r1); | |
820 | #else | |
821 | #define PPC_40x_TURN_OFF_MSR_DR | |
822 | #endif | |
823 | ||
824 | #define RET_FROM_EXC_LEVEL(exc_lvl_srr0, exc_lvl_srr1, exc_lvl_rfi) \ | |
825 | REST_NVGPRS(r1); \ | |
826 | lwz r3,_MSR(r1); \ | |
827 | andi. r3,r3,MSR_PR; \ | |
828 | LOAD_MSR_KERNEL(r10,MSR_KERNEL); \ | |
829 | bne user_exc_return; \ | |
830 | lwz r0,GPR0(r1); \ | |
831 | lwz r2,GPR2(r1); \ | |
832 | REST_4GPRS(3, r1); \ | |
833 | REST_2GPRS(7, r1); \ | |
834 | lwz r10,_XER(r1); \ | |
835 | lwz r11,_CTR(r1); \ | |
836 | mtspr SPRN_XER,r10; \ | |
837 | mtctr r11; \ | |
838 | PPC405_ERR77(0,r1); \ | |
839 | stwcx. r0,0,r1; /* to clear the reservation */ \ | |
840 | lwz r11,_LINK(r1); \ | |
841 | mtlr r11; \ | |
842 | lwz r10,_CCR(r1); \ | |
843 | mtcrf 0xff,r10; \ | |
844 | PPC_40x_TURN_OFF_MSR_DR; \ | |
845 | lwz r9,_DEAR(r1); \ | |
846 | lwz r10,_ESR(r1); \ | |
847 | mtspr SPRN_DEAR,r9; \ | |
848 | mtspr SPRN_ESR,r10; \ | |
849 | lwz r11,_NIP(r1); \ | |
850 | lwz r12,_MSR(r1); \ | |
851 | mtspr exc_lvl_srr0,r11; \ | |
852 | mtspr exc_lvl_srr1,r12; \ | |
853 | lwz r9,GPR9(r1); \ | |
854 | lwz r12,GPR12(r1); \ | |
855 | lwz r10,GPR10(r1); \ | |
856 | lwz r11,GPR11(r1); \ | |
857 | lwz r1,GPR1(r1); \ | |
858 | PPC405_ERR77_SYNC; \ | |
859 | exc_lvl_rfi; \ | |
860 | b .; /* prevent prefetch past exc_lvl_rfi */ | |
861 | ||
862 | .globl ret_from_crit_exc | |
863 | ret_from_crit_exc: | |
864 | RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, RFCI) | |
865 | ||
866 | #ifdef CONFIG_BOOKE | |
867 | .globl ret_from_debug_exc | |
868 | ret_from_debug_exc: | |
869 | RET_FROM_EXC_LEVEL(SPRN_DSRR0, SPRN_DSRR1, RFDI) | |
870 | ||
871 | .globl ret_from_mcheck_exc | |
872 | ret_from_mcheck_exc: | |
873 | RET_FROM_EXC_LEVEL(SPRN_MCSRR0, SPRN_MCSRR1, RFMCI) | |
874 | #endif /* CONFIG_BOOKE */ | |
875 | ||
876 | /* | |
877 | * Load the DBCR0 value for a task that is being ptraced, | |
878 | * having first saved away the global DBCR0. Note that r0 | |
879 | * has the dbcr0 value to set upon entry to this. | |
880 | */ | |
881 | load_dbcr0: | |
882 | mfmsr r10 /* first disable debug exceptions */ | |
883 | rlwinm r10,r10,0,~MSR_DE | |
884 | mtmsr r10 | |
885 | isync | |
886 | mfspr r10,SPRN_DBCR0 | |
887 | lis r11,global_dbcr0@ha | |
888 | addi r11,r11,global_dbcr0@l | |
4eaddb4d KG |
889 | #ifdef CONFIG_SMP |
890 | rlwinm r9,r1,0,0,(31-THREAD_SHIFT) | |
891 | lwz r9,TI_CPU(r9) | |
892 | slwi r9,r9,3 | |
893 | add r11,r11,r9 | |
894 | #endif | |
9994a338 PM |
895 | stw r10,0(r11) |
896 | mtspr SPRN_DBCR0,r0 | |
897 | lwz r10,4(r11) | |
898 | addi r10,r10,1 | |
899 | stw r10,4(r11) | |
900 | li r11,-1 | |
901 | mtspr SPRN_DBSR,r11 /* clear all pending debug events */ | |
902 | blr | |
903 | ||
991eb43a KG |
904 | .section .bss |
905 | .align 4 | |
906 | global_dbcr0: | |
4eaddb4d | 907 | .space 8*NR_CPUS |
991eb43a | 908 | .previous |
9994a338 PM |
909 | #endif /* !(CONFIG_4xx || CONFIG_BOOKE) */ |
910 | ||
911 | do_work: /* r10 contains MSR_KERNEL here */ | |
912 | andi. r0,r9,_TIF_NEED_RESCHED | |
913 | beq do_user_signal | |
914 | ||
915 | do_resched: /* r10 contains MSR_KERNEL here */ | |
916 | ori r10,r10,MSR_EE | |
917 | SYNC | |
918 | MTMSRD(r10) /* hard-enable interrupts */ | |
919 | bl schedule | |
920 | recheck: | |
921 | LOAD_MSR_KERNEL(r10,MSR_KERNEL) | |
922 | SYNC | |
923 | MTMSRD(r10) /* disable interrupts */ | |
6cb7bfeb | 924 | rlwinm r9,r1,0,0,(31-THREAD_SHIFT) |
9994a338 PM |
925 | lwz r9,TI_FLAGS(r9) |
926 | andi. r0,r9,_TIF_NEED_RESCHED | |
927 | bne- do_resched | |
f27201da | 928 | andi. r0,r9,_TIF_SIGPENDING|_TIF_RESTORE_SIGMASK |
9994a338 PM |
929 | beq restore_user |
930 | do_user_signal: /* r10 contains MSR_KERNEL here */ | |
931 | ori r10,r10,MSR_EE | |
932 | SYNC | |
933 | MTMSRD(r10) /* hard-enable interrupts */ | |
934 | /* save r13-r31 in the exception frame, if not already done */ | |
d73e0c99 | 935 | lwz r3,_TRAP(r1) |
9994a338 PM |
936 | andi. r0,r3,1 |
937 | beq 2f | |
938 | SAVE_NVGPRS(r1) | |
939 | rlwinm r3,r3,0,0,30 | |
d73e0c99 | 940 | stw r3,_TRAP(r1) |
9994a338 PM |
941 | 2: li r3,0 |
942 | addi r4,r1,STACK_FRAME_OVERHEAD | |
943 | bl do_signal | |
944 | REST_NVGPRS(r1) | |
945 | b recheck | |
946 | ||
947 | /* | |
948 | * We come here when we are at the end of handling an exception | |
949 | * that occurred at a place where taking an exception will lose | |
950 | * state information, such as the contents of SRR0 and SRR1. | |
951 | */ | |
952 | nonrecoverable: | |
953 | lis r10,exc_exit_restart_end@ha | |
954 | addi r10,r10,exc_exit_restart_end@l | |
955 | cmplw r12,r10 | |
956 | bge 3f | |
957 | lis r11,exc_exit_restart@ha | |
958 | addi r11,r11,exc_exit_restart@l | |
959 | cmplw r12,r11 | |
960 | blt 3f | |
961 | lis r10,ee_restarts@ha | |
962 | lwz r12,ee_restarts@l(r10) | |
963 | addi r12,r12,1 | |
964 | stw r12,ee_restarts@l(r10) | |
965 | mr r12,r11 /* restart at exc_exit_restart */ | |
966 | blr | |
967 | 3: /* OK, we can't recover, kill this process */ | |
968 | /* but the 601 doesn't implement the RI bit, so assume it's OK */ | |
969 | BEGIN_FTR_SECTION | |
970 | blr | |
971 | END_FTR_SECTION_IFSET(CPU_FTR_601) | |
d73e0c99 | 972 | lwz r3,_TRAP(r1) |
9994a338 PM |
973 | andi. r0,r3,1 |
974 | beq 4f | |
975 | SAVE_NVGPRS(r1) | |
976 | rlwinm r3,r3,0,0,30 | |
d73e0c99 | 977 | stw r3,_TRAP(r1) |
9994a338 PM |
978 | 4: addi r3,r1,STACK_FRAME_OVERHEAD |
979 | bl nonrecoverable_exception | |
980 | /* shouldn't return */ | |
981 | b 4b | |
982 | ||
991eb43a KG |
983 | .section .bss |
984 | .align 2 | |
985 | ee_restarts: | |
986 | .space 4 | |
987 | .previous | |
9994a338 PM |
988 | |
989 | /* | |
990 | * PROM code for specific machines follows. Put it | |
991 | * here so it's easy to add arch-specific sections later. | |
992 | * -- Cort | |
993 | */ | |
033ef338 | 994 | #ifdef CONFIG_PPC_RTAS |
9994a338 PM |
995 | /* |
996 | * On CHRP, the Run-Time Abstraction Services (RTAS) have to be | |
997 | * called with the MMU off. | |
998 | */ | |
999 | _GLOBAL(enter_rtas) | |
1000 | stwu r1,-INT_FRAME_SIZE(r1) | |
1001 | mflr r0 | |
1002 | stw r0,INT_FRAME_SIZE+4(r1) | |
e58c3495 | 1003 | LOAD_REG_ADDR(r4, rtas) |
9994a338 PM |
1004 | lis r6,1f@ha /* physical return address for rtas */ |
1005 | addi r6,r6,1f@l | |
1006 | tophys(r6,r6) | |
1007 | tophys(r7,r1) | |
033ef338 PM |
1008 | lwz r8,RTASENTRY(r4) |
1009 | lwz r4,RTASBASE(r4) | |
9994a338 PM |
1010 | mfmsr r9 |
1011 | stw r9,8(r1) | |
1012 | LOAD_MSR_KERNEL(r0,MSR_KERNEL) | |
1013 | SYNC /* disable interrupts so SRR0/1 */ | |
1014 | MTMSRD(r0) /* don't get trashed */ | |
1015 | li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR) | |
1016 | mtlr r6 | |
9994a338 PM |
1017 | mtspr SPRN_SPRG2,r7 |
1018 | mtspr SPRN_SRR0,r8 | |
1019 | mtspr SPRN_SRR1,r9 | |
1020 | RFI | |
1021 | 1: tophys(r9,r1) | |
1022 | lwz r8,INT_FRAME_SIZE+4(r9) /* get return address */ | |
1023 | lwz r9,8(r9) /* original msr value */ | |
1024 | FIX_SRR1(r9,r0) | |
1025 | addi r1,r1,INT_FRAME_SIZE | |
1026 | li r0,0 | |
1027 | mtspr SPRN_SPRG2,r0 | |
1028 | mtspr SPRN_SRR0,r8 | |
1029 | mtspr SPRN_SRR1,r9 | |
1030 | RFI /* return to caller */ | |
1031 | ||
1032 | .globl machine_check_in_rtas | |
1033 | machine_check_in_rtas: | |
1034 | twi 31,0,0 | |
1035 | /* XXX load up BATs and panic */ | |
1036 | ||
033ef338 | 1037 | #endif /* CONFIG_PPC_RTAS */ |