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9994a338 | 1 | /* |
9994a338 PM |
2 | * PowerPC version |
3 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
4 | * Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP | |
5 | * Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu> | |
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 | ||
9994a338 PM |
21 | #include <linux/errno.h> |
22 | #include <asm/unistd.h> | |
23 | #include <asm/processor.h> | |
24 | #include <asm/page.h> | |
25 | #include <asm/mmu.h> | |
26 | #include <asm/thread_info.h> | |
27 | #include <asm/ppc_asm.h> | |
28 | #include <asm/asm-offsets.h> | |
29 | #include <asm/cputable.h> | |
30 | ||
31 | #ifdef CONFIG_PPC_ISERIES | |
32 | #define DO_SOFT_DISABLE | |
33 | #endif | |
34 | ||
35 | /* | |
36 | * System calls. | |
37 | */ | |
38 | .section ".toc","aw" | |
39 | .SYS_CALL_TABLE: | |
40 | .tc .sys_call_table[TC],.sys_call_table | |
41 | ||
42 | /* This value is used to mark exception frames on the stack. */ | |
43 | exception_marker: | |
44 | .tc ID_72656773_68657265[TC],0x7265677368657265 | |
45 | ||
46 | .section ".text" | |
47 | .align 7 | |
48 | ||
49 | #undef SHOW_SYSCALLS | |
50 | ||
51 | .globl system_call_common | |
52 | system_call_common: | |
53 | andi. r10,r12,MSR_PR | |
54 | mr r10,r1 | |
55 | addi r1,r1,-INT_FRAME_SIZE | |
56 | beq- 1f | |
57 | ld r1,PACAKSAVE(r13) | |
58 | 1: std r10,0(r1) | |
bd19c899 | 59 | crclr so |
9994a338 PM |
60 | std r11,_NIP(r1) |
61 | std r12,_MSR(r1) | |
62 | std r0,GPR0(r1) | |
63 | std r10,GPR1(r1) | |
c6622f63 | 64 | ACCOUNT_CPU_USER_ENTRY(r10, r11) |
9994a338 PM |
65 | std r2,GPR2(r1) |
66 | std r3,GPR3(r1) | |
67 | std r4,GPR4(r1) | |
68 | std r5,GPR5(r1) | |
69 | std r6,GPR6(r1) | |
70 | std r7,GPR7(r1) | |
71 | std r8,GPR8(r1) | |
72 | li r11,0 | |
73 | std r11,GPR9(r1) | |
74 | std r11,GPR10(r1) | |
75 | std r11,GPR11(r1) | |
76 | std r11,GPR12(r1) | |
77 | std r9,GPR13(r1) | |
9994a338 PM |
78 | mfcr r9 |
79 | mflr r10 | |
80 | li r11,0xc01 | |
81 | std r9,_CCR(r1) | |
82 | std r10,_LINK(r1) | |
83 | std r11,_TRAP(r1) | |
84 | mfxer r9 | |
85 | mfctr r10 | |
86 | std r9,_XER(r1) | |
87 | std r10,_CTR(r1) | |
88 | std r3,ORIG_GPR3(r1) | |
89 | ld r2,PACATOC(r13) | |
90 | addi r9,r1,STACK_FRAME_OVERHEAD | |
91 | ld r11,exception_marker@toc(r2) | |
92 | std r11,-16(r9) /* "regshere" marker */ | |
93 | #ifdef CONFIG_PPC_ISERIES | |
94 | /* Hack for handling interrupts when soft-enabling on iSeries */ | |
95 | cmpdi cr1,r0,0x5555 /* syscall 0x5555 */ | |
96 | andi. r10,r12,MSR_PR /* from kernel */ | |
97 | crand 4*cr0+eq,4*cr1+eq,4*cr0+eq | |
98 | beq hardware_interrupt_entry | |
99 | lbz r10,PACAPROCENABLED(r13) | |
100 | std r10,SOFTE(r1) | |
101 | #endif | |
102 | mfmsr r11 | |
103 | ori r11,r11,MSR_EE | |
104 | mtmsrd r11,1 | |
105 | ||
106 | #ifdef SHOW_SYSCALLS | |
107 | bl .do_show_syscall | |
108 | REST_GPR(0,r1) | |
109 | REST_4GPRS(3,r1) | |
110 | REST_2GPRS(7,r1) | |
111 | addi r9,r1,STACK_FRAME_OVERHEAD | |
112 | #endif | |
113 | clrrdi r11,r1,THREAD_SHIFT | |
9994a338 | 114 | ld r10,TI_FLAGS(r11) |
9994a338 PM |
115 | andi. r11,r10,_TIF_SYSCALL_T_OR_A |
116 | bne- syscall_dotrace | |
117 | syscall_dotrace_cont: | |
118 | cmpldi 0,r0,NR_syscalls | |
119 | bge- syscall_enosys | |
120 | ||
121 | system_call: /* label this so stack traces look sane */ | |
122 | /* | |
123 | * Need to vector to 32 Bit or default sys_call_table here, | |
124 | * based on caller's run-mode / personality. | |
125 | */ | |
126 | ld r11,.SYS_CALL_TABLE@toc(2) | |
127 | andi. r10,r10,_TIF_32BIT | |
128 | beq 15f | |
129 | addi r11,r11,8 /* use 32-bit syscall entries */ | |
130 | clrldi r3,r3,32 | |
131 | clrldi r4,r4,32 | |
132 | clrldi r5,r5,32 | |
133 | clrldi r6,r6,32 | |
134 | clrldi r7,r7,32 | |
135 | clrldi r8,r8,32 | |
136 | 15: | |
137 | slwi r0,r0,4 | |
138 | ldx r10,r11,r0 /* Fetch system call handler [ptr] */ | |
139 | mtctr r10 | |
140 | bctrl /* Call handler */ | |
141 | ||
142 | syscall_exit: | |
401d1f02 | 143 | std r3,RESULT(r1) |
9994a338 | 144 | #ifdef SHOW_SYSCALLS |
9994a338 | 145 | bl .do_show_syscall_exit |
401d1f02 | 146 | ld r3,RESULT(r1) |
9994a338 | 147 | #endif |
9994a338 | 148 | clrrdi r12,r1,THREAD_SHIFT |
9994a338 PM |
149 | |
150 | /* disable interrupts so current_thread_info()->flags can't change, | |
151 | and so that we don't get interrupted after loading SRR0/1. */ | |
152 | ld r8,_MSR(r1) | |
153 | andi. r10,r8,MSR_RI | |
154 | beq- unrecov_restore | |
155 | mfmsr r10 | |
156 | rldicl r10,r10,48,1 | |
157 | rotldi r10,r10,16 | |
158 | mtmsrd r10,1 | |
159 | ld r9,TI_FLAGS(r12) | |
401d1f02 | 160 | li r11,-_LAST_ERRNO |
1bd79336 | 161 | andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) |
9994a338 | 162 | bne- syscall_exit_work |
401d1f02 DW |
163 | cmpld r3,r11 |
164 | ld r5,_CCR(r1) | |
165 | bge- syscall_error | |
166 | syscall_error_cont: | |
9994a338 PM |
167 | ld r7,_NIP(r1) |
168 | stdcx. r0,0,r1 /* to clear the reservation */ | |
169 | andi. r6,r8,MSR_PR | |
170 | ld r4,_LINK(r1) | |
c6622f63 PM |
171 | beq- 1f |
172 | ACCOUNT_CPU_USER_EXIT(r11, r12) | |
173 | ld r13,GPR13(r1) /* only restore r13 if returning to usermode */ | |
9994a338 PM |
174 | 1: ld r2,GPR2(r1) |
175 | li r12,MSR_RI | |
3eb6f26b PM |
176 | andc r11,r10,r12 |
177 | mtmsrd r11,1 /* clear MSR.RI */ | |
9994a338 PM |
178 | ld r1,GPR1(r1) |
179 | mtlr r4 | |
180 | mtcr r5 | |
181 | mtspr SPRN_SRR0,r7 | |
182 | mtspr SPRN_SRR1,r8 | |
183 | rfid | |
184 | b . /* prevent speculative execution */ | |
185 | ||
401d1f02 | 186 | syscall_error: |
9994a338 | 187 | oris r5,r5,0x1000 /* Set SO bit in CR */ |
401d1f02 | 188 | neg r3,r3 |
9994a338 PM |
189 | std r5,_CCR(r1) |
190 | b syscall_error_cont | |
401d1f02 | 191 | |
9994a338 PM |
192 | /* Traced system call support */ |
193 | syscall_dotrace: | |
194 | bl .save_nvgprs | |
195 | addi r3,r1,STACK_FRAME_OVERHEAD | |
196 | bl .do_syscall_trace_enter | |
197 | ld r0,GPR0(r1) /* Restore original registers */ | |
198 | ld r3,GPR3(r1) | |
199 | ld r4,GPR4(r1) | |
200 | ld r5,GPR5(r1) | |
201 | ld r6,GPR6(r1) | |
202 | ld r7,GPR7(r1) | |
203 | ld r8,GPR8(r1) | |
204 | addi r9,r1,STACK_FRAME_OVERHEAD | |
205 | clrrdi r10,r1,THREAD_SHIFT | |
206 | ld r10,TI_FLAGS(r10) | |
207 | b syscall_dotrace_cont | |
208 | ||
401d1f02 DW |
209 | syscall_enosys: |
210 | li r3,-ENOSYS | |
211 | b syscall_exit | |
212 | ||
213 | syscall_exit_work: | |
214 | /* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr. | |
215 | If TIF_NOERROR is set, just save r3 as it is. */ | |
216 | ||
217 | andi. r0,r9,_TIF_RESTOREALL | |
1bd79336 PM |
218 | beq+ 0f |
219 | REST_NVGPRS(r1) | |
220 | b 2f | |
221 | 0: cmpld r3,r11 /* r10 is -LAST_ERRNO */ | |
401d1f02 DW |
222 | blt+ 1f |
223 | andi. r0,r9,_TIF_NOERROR | |
224 | bne- 1f | |
225 | ld r5,_CCR(r1) | |
226 | neg r3,r3 | |
227 | oris r5,r5,0x1000 /* Set SO bit in CR */ | |
228 | std r5,_CCR(r1) | |
229 | 1: std r3,GPR3(r1) | |
230 | 2: andi. r0,r9,(_TIF_PERSYSCALL_MASK) | |
231 | beq 4f | |
232 | ||
1bd79336 | 233 | /* Clear per-syscall TIF flags if any are set. */ |
401d1f02 DW |
234 | |
235 | li r11,_TIF_PERSYSCALL_MASK | |
236 | addi r12,r12,TI_FLAGS | |
237 | 3: ldarx r10,0,r12 | |
238 | andc r10,r10,r11 | |
239 | stdcx. r10,0,r12 | |
240 | bne- 3b | |
241 | subi r12,r12,TI_FLAGS | |
1bd79336 PM |
242 | |
243 | 4: /* Anything else left to do? */ | |
244 | andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP) | |
401d1f02 DW |
245 | beq .ret_from_except_lite |
246 | ||
247 | /* Re-enable interrupts */ | |
248 | mfmsr r10 | |
249 | ori r10,r10,MSR_EE | |
250 | mtmsrd r10,1 | |
251 | ||
1bd79336 | 252 | bl .save_nvgprs |
9994a338 PM |
253 | addi r3,r1,STACK_FRAME_OVERHEAD |
254 | bl .do_syscall_trace_leave | |
1bd79336 | 255 | b .ret_from_except |
9994a338 PM |
256 | |
257 | /* Save non-volatile GPRs, if not already saved. */ | |
258 | _GLOBAL(save_nvgprs) | |
259 | ld r11,_TRAP(r1) | |
260 | andi. r0,r11,1 | |
261 | beqlr- | |
262 | SAVE_NVGPRS(r1) | |
263 | clrrdi r0,r11,1 | |
264 | std r0,_TRAP(r1) | |
265 | blr | |
266 | ||
401d1f02 | 267 | |
9994a338 PM |
268 | /* |
269 | * The sigsuspend and rt_sigsuspend system calls can call do_signal | |
270 | * and thus put the process into the stopped state where we might | |
271 | * want to examine its user state with ptrace. Therefore we need | |
272 | * to save all the nonvolatile registers (r14 - r31) before calling | |
273 | * the C code. Similarly, fork, vfork and clone need the full | |
274 | * register state on the stack so that it can be copied to the child. | |
275 | */ | |
9994a338 PM |
276 | |
277 | _GLOBAL(ppc_fork) | |
278 | bl .save_nvgprs | |
279 | bl .sys_fork | |
280 | b syscall_exit | |
281 | ||
282 | _GLOBAL(ppc_vfork) | |
283 | bl .save_nvgprs | |
284 | bl .sys_vfork | |
285 | b syscall_exit | |
286 | ||
287 | _GLOBAL(ppc_clone) | |
288 | bl .save_nvgprs | |
289 | bl .sys_clone | |
290 | b syscall_exit | |
291 | ||
1bd79336 PM |
292 | _GLOBAL(ppc32_swapcontext) |
293 | bl .save_nvgprs | |
294 | bl .compat_sys_swapcontext | |
295 | b syscall_exit | |
296 | ||
297 | _GLOBAL(ppc64_swapcontext) | |
298 | bl .save_nvgprs | |
299 | bl .sys_swapcontext | |
300 | b syscall_exit | |
301 | ||
9994a338 PM |
302 | _GLOBAL(ret_from_fork) |
303 | bl .schedule_tail | |
304 | REST_NVGPRS(r1) | |
305 | li r3,0 | |
306 | b syscall_exit | |
307 | ||
308 | /* | |
309 | * This routine switches between two different tasks. The process | |
310 | * state of one is saved on its kernel stack. Then the state | |
311 | * of the other is restored from its kernel stack. The memory | |
312 | * management hardware is updated to the second process's state. | |
313 | * Finally, we can return to the second process, via ret_from_except. | |
314 | * On entry, r3 points to the THREAD for the current task, r4 | |
315 | * points to the THREAD for the new task. | |
316 | * | |
317 | * Note: there are two ways to get to the "going out" portion | |
318 | * of this code; either by coming in via the entry (_switch) | |
319 | * or via "fork" which must set up an environment equivalent | |
320 | * to the "_switch" path. If you change this you'll have to change | |
321 | * the fork code also. | |
322 | * | |
323 | * The code which creates the new task context is in 'copy_thread' | |
2ef9481e | 324 | * in arch/powerpc/kernel/process.c |
9994a338 PM |
325 | */ |
326 | .align 7 | |
327 | _GLOBAL(_switch) | |
328 | mflr r0 | |
329 | std r0,16(r1) | |
330 | stdu r1,-SWITCH_FRAME_SIZE(r1) | |
331 | /* r3-r13 are caller saved -- Cort */ | |
332 | SAVE_8GPRS(14, r1) | |
333 | SAVE_10GPRS(22, r1) | |
334 | mflr r20 /* Return to switch caller */ | |
335 | mfmsr r22 | |
336 | li r0, MSR_FP | |
337 | #ifdef CONFIG_ALTIVEC | |
338 | BEGIN_FTR_SECTION | |
339 | oris r0,r0,MSR_VEC@h /* Disable altivec */ | |
340 | mfspr r24,SPRN_VRSAVE /* save vrsave register value */ | |
341 | std r24,THREAD_VRSAVE(r3) | |
342 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) | |
343 | #endif /* CONFIG_ALTIVEC */ | |
344 | and. r0,r0,r22 | |
345 | beq+ 1f | |
346 | andc r22,r22,r0 | |
347 | mtmsrd r22 | |
348 | isync | |
349 | 1: std r20,_NIP(r1) | |
350 | mfcr r23 | |
351 | std r23,_CCR(r1) | |
352 | std r1,KSP(r3) /* Set old stack pointer */ | |
353 | ||
354 | #ifdef CONFIG_SMP | |
355 | /* We need a sync somewhere here to make sure that if the | |
356 | * previous task gets rescheduled on another CPU, it sees all | |
357 | * stores it has performed on this one. | |
358 | */ | |
359 | sync | |
360 | #endif /* CONFIG_SMP */ | |
361 | ||
362 | addi r6,r4,-THREAD /* Convert THREAD to 'current' */ | |
363 | std r6,PACACURRENT(r13) /* Set new 'current' */ | |
364 | ||
365 | ld r8,KSP(r4) /* new stack pointer */ | |
366 | BEGIN_FTR_SECTION | |
367 | clrrdi r6,r8,28 /* get its ESID */ | |
368 | clrrdi r9,r1,28 /* get current sp ESID */ | |
369 | clrldi. r0,r6,2 /* is new ESID c00000000? */ | |
370 | cmpd cr1,r6,r9 /* or is new ESID the same as current ESID? */ | |
371 | cror eq,4*cr1+eq,eq | |
372 | beq 2f /* if yes, don't slbie it */ | |
373 | ||
374 | /* Bolt in the new stack SLB entry */ | |
375 | ld r7,KSP_VSID(r4) /* Get new stack's VSID */ | |
376 | oris r0,r6,(SLB_ESID_V)@h | |
377 | ori r0,r0,(SLB_NUM_BOLTED-1)@l | |
2f6093c8 MN |
378 | |
379 | /* Update the last bolted SLB */ | |
380 | ld r9,PACA_SLBSHADOWPTR(r13) | |
11a27ad7 MN |
381 | li r12,0 |
382 | std r12,SLBSHADOW_STACKESID(r9) /* Clear ESID */ | |
383 | std r7,SLBSHADOW_STACKVSID(r9) /* Save VSID */ | |
384 | std r0,SLBSHADOW_STACKESID(r9) /* Save ESID */ | |
2f6093c8 | 385 | |
9994a338 PM |
386 | slbie r6 |
387 | slbie r6 /* Workaround POWER5 < DD2.1 issue */ | |
388 | slbmte r7,r0 | |
389 | isync | |
390 | ||
391 | 2: | |
392 | END_FTR_SECTION_IFSET(CPU_FTR_SLB) | |
393 | clrrdi r7,r8,THREAD_SHIFT /* base of new stack */ | |
394 | /* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE | |
395 | because we don't need to leave the 288-byte ABI gap at the | |
396 | top of the kernel stack. */ | |
397 | addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE | |
398 | ||
399 | mr r1,r8 /* start using new stack pointer */ | |
400 | std r7,PACAKSAVE(r13) | |
401 | ||
402 | ld r6,_CCR(r1) | |
403 | mtcrf 0xFF,r6 | |
404 | ||
405 | #ifdef CONFIG_ALTIVEC | |
406 | BEGIN_FTR_SECTION | |
407 | ld r0,THREAD_VRSAVE(r4) | |
408 | mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */ | |
409 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) | |
410 | #endif /* CONFIG_ALTIVEC */ | |
411 | ||
412 | /* r3-r13 are destroyed -- Cort */ | |
413 | REST_8GPRS(14, r1) | |
414 | REST_10GPRS(22, r1) | |
415 | ||
416 | /* convert old thread to its task_struct for return value */ | |
417 | addi r3,r3,-THREAD | |
418 | ld r7,_NIP(r1) /* Return to _switch caller in new task */ | |
419 | mtlr r7 | |
420 | addi r1,r1,SWITCH_FRAME_SIZE | |
421 | blr | |
422 | ||
423 | .align 7 | |
424 | _GLOBAL(ret_from_except) | |
425 | ld r11,_TRAP(r1) | |
426 | andi. r0,r11,1 | |
427 | bne .ret_from_except_lite | |
428 | REST_NVGPRS(r1) | |
429 | ||
430 | _GLOBAL(ret_from_except_lite) | |
431 | /* | |
432 | * Disable interrupts so that current_thread_info()->flags | |
433 | * can't change between when we test it and when we return | |
434 | * from the interrupt. | |
435 | */ | |
436 | mfmsr r10 /* Get current interrupt state */ | |
437 | rldicl r9,r10,48,1 /* clear MSR_EE */ | |
438 | rotldi r9,r9,16 | |
439 | mtmsrd r9,1 /* Update machine state */ | |
440 | ||
441 | #ifdef CONFIG_PREEMPT | |
442 | clrrdi r9,r1,THREAD_SHIFT /* current_thread_info() */ | |
443 | li r0,_TIF_NEED_RESCHED /* bits to check */ | |
444 | ld r3,_MSR(r1) | |
445 | ld r4,TI_FLAGS(r9) | |
446 | /* Move MSR_PR bit in r3 to _TIF_SIGPENDING position in r0 */ | |
447 | rlwimi r0,r3,32+TIF_SIGPENDING-MSR_PR_LG,_TIF_SIGPENDING | |
448 | and. r0,r4,r0 /* check NEED_RESCHED and maybe SIGPENDING */ | |
449 | bne do_work | |
450 | ||
451 | #else /* !CONFIG_PREEMPT */ | |
452 | ld r3,_MSR(r1) /* Returning to user mode? */ | |
453 | andi. r3,r3,MSR_PR | |
454 | beq restore /* if not, just restore regs and return */ | |
455 | ||
456 | /* Check current_thread_info()->flags */ | |
457 | clrrdi r9,r1,THREAD_SHIFT | |
458 | ld r4,TI_FLAGS(r9) | |
459 | andi. r0,r4,_TIF_USER_WORK_MASK | |
460 | bne do_work | |
461 | #endif | |
462 | ||
463 | restore: | |
464 | #ifdef CONFIG_PPC_ISERIES | |
465 | ld r5,SOFTE(r1) | |
466 | cmpdi 0,r5,0 | |
467 | beq 4f | |
468 | /* Check for pending interrupts (iSeries) */ | |
3356bb9f DG |
469 | ld r3,PACALPPACAPTR(r13) |
470 | ld r3,LPPACAANYINT(r3) | |
9994a338 PM |
471 | cmpdi r3,0 |
472 | beq+ 4f /* skip do_IRQ if no interrupts */ | |
473 | ||
474 | li r3,0 | |
475 | stb r3,PACAPROCENABLED(r13) /* ensure we are soft-disabled */ | |
476 | ori r10,r10,MSR_EE | |
477 | mtmsrd r10 /* hard-enable again */ | |
478 | addi r3,r1,STACK_FRAME_OVERHEAD | |
479 | bl .do_IRQ | |
480 | b .ret_from_except_lite /* loop back and handle more */ | |
481 | ||
482 | 4: stb r5,PACAPROCENABLED(r13) | |
483 | #endif | |
484 | ||
485 | ld r3,_MSR(r1) | |
486 | andi. r0,r3,MSR_RI | |
487 | beq- unrecov_restore | |
488 | ||
489 | andi. r0,r3,MSR_PR | |
490 | ||
491 | /* | |
492 | * r13 is our per cpu area, only restore it if we are returning to | |
493 | * userspace | |
494 | */ | |
495 | beq 1f | |
c6622f63 | 496 | ACCOUNT_CPU_USER_EXIT(r3, r4) |
9994a338 PM |
497 | REST_GPR(13, r1) |
498 | 1: | |
499 | ld r3,_CTR(r1) | |
500 | ld r0,_LINK(r1) | |
501 | mtctr r3 | |
502 | mtlr r0 | |
503 | ld r3,_XER(r1) | |
504 | mtspr SPRN_XER,r3 | |
505 | ||
506 | REST_8GPRS(5, r1) | |
507 | ||
508 | stdcx. r0,0,r1 /* to clear the reservation */ | |
509 | ||
510 | mfmsr r0 | |
511 | li r2, MSR_RI | |
512 | andc r0,r0,r2 | |
513 | mtmsrd r0,1 | |
514 | ||
515 | ld r0,_MSR(r1) | |
516 | mtspr SPRN_SRR1,r0 | |
517 | ||
518 | ld r2,_CCR(r1) | |
519 | mtcrf 0xFF,r2 | |
520 | ld r2,_NIP(r1) | |
521 | mtspr SPRN_SRR0,r2 | |
522 | ||
523 | ld r0,GPR0(r1) | |
524 | ld r2,GPR2(r1) | |
525 | ld r3,GPR3(r1) | |
526 | ld r4,GPR4(r1) | |
527 | ld r1,GPR1(r1) | |
528 | ||
529 | rfid | |
530 | b . /* prevent speculative execution */ | |
531 | ||
532 | /* Note: this must change if we start using the TIF_NOTIFY_RESUME bit */ | |
533 | do_work: | |
534 | #ifdef CONFIG_PREEMPT | |
535 | andi. r0,r3,MSR_PR /* Returning to user mode? */ | |
536 | bne user_work | |
537 | /* Check that preempt_count() == 0 and interrupts are enabled */ | |
538 | lwz r8,TI_PREEMPT(r9) | |
539 | cmpwi cr1,r8,0 | |
540 | #ifdef CONFIG_PPC_ISERIES | |
541 | ld r0,SOFTE(r1) | |
542 | cmpdi r0,0 | |
543 | #else | |
544 | andi. r0,r3,MSR_EE | |
545 | #endif | |
546 | crandc eq,cr1*4+eq,eq | |
547 | bne restore | |
548 | /* here we are preempting the current task */ | |
549 | 1: | |
550 | #ifdef CONFIG_PPC_ISERIES | |
551 | li r0,1 | |
552 | stb r0,PACAPROCENABLED(r13) | |
553 | #endif | |
554 | ori r10,r10,MSR_EE | |
555 | mtmsrd r10,1 /* reenable interrupts */ | |
556 | bl .preempt_schedule | |
557 | mfmsr r10 | |
558 | clrrdi r9,r1,THREAD_SHIFT | |
559 | rldicl r10,r10,48,1 /* disable interrupts again */ | |
560 | rotldi r10,r10,16 | |
561 | mtmsrd r10,1 | |
562 | ld r4,TI_FLAGS(r9) | |
563 | andi. r0,r4,_TIF_NEED_RESCHED | |
564 | bne 1b | |
565 | b restore | |
566 | ||
567 | user_work: | |
568 | #endif | |
569 | /* Enable interrupts */ | |
570 | ori r10,r10,MSR_EE | |
571 | mtmsrd r10,1 | |
572 | ||
573 | andi. r0,r4,_TIF_NEED_RESCHED | |
574 | beq 1f | |
575 | bl .schedule | |
576 | b .ret_from_except_lite | |
577 | ||
578 | 1: bl .save_nvgprs | |
579 | li r3,0 | |
580 | addi r4,r1,STACK_FRAME_OVERHEAD | |
581 | bl .do_signal | |
582 | b .ret_from_except | |
583 | ||
584 | unrecov_restore: | |
585 | addi r3,r1,STACK_FRAME_OVERHEAD | |
586 | bl .unrecoverable_exception | |
587 | b unrecov_restore | |
588 | ||
589 | #ifdef CONFIG_PPC_RTAS | |
590 | /* | |
591 | * On CHRP, the Run-Time Abstraction Services (RTAS) have to be | |
592 | * called with the MMU off. | |
593 | * | |
594 | * In addition, we need to be in 32b mode, at least for now. | |
595 | * | |
596 | * Note: r3 is an input parameter to rtas, so don't trash it... | |
597 | */ | |
598 | _GLOBAL(enter_rtas) | |
599 | mflr r0 | |
600 | std r0,16(r1) | |
601 | stdu r1,-RTAS_FRAME_SIZE(r1) /* Save SP and create stack space. */ | |
602 | ||
603 | /* Because RTAS is running in 32b mode, it clobbers the high order half | |
604 | * of all registers that it saves. We therefore save those registers | |
605 | * RTAS might touch to the stack. (r0, r3-r13 are caller saved) | |
606 | */ | |
607 | SAVE_GPR(2, r1) /* Save the TOC */ | |
608 | SAVE_GPR(13, r1) /* Save paca */ | |
609 | SAVE_8GPRS(14, r1) /* Save the non-volatiles */ | |
610 | SAVE_10GPRS(22, r1) /* ditto */ | |
611 | ||
612 | mfcr r4 | |
613 | std r4,_CCR(r1) | |
614 | mfctr r5 | |
615 | std r5,_CTR(r1) | |
616 | mfspr r6,SPRN_XER | |
617 | std r6,_XER(r1) | |
618 | mfdar r7 | |
619 | std r7,_DAR(r1) | |
620 | mfdsisr r8 | |
621 | std r8,_DSISR(r1) | |
622 | mfsrr0 r9 | |
623 | std r9,_SRR0(r1) | |
624 | mfsrr1 r10 | |
625 | std r10,_SRR1(r1) | |
626 | ||
9fe901d1 MK |
627 | /* Temporary workaround to clear CR until RTAS can be modified to |
628 | * ignore all bits. | |
629 | */ | |
630 | li r0,0 | |
631 | mtcr r0 | |
632 | ||
9994a338 PM |
633 | /* There is no way it is acceptable to get here with interrupts enabled, |
634 | * check it with the asm equivalent of WARN_ON | |
635 | */ | |
636 | mfmsr r6 | |
637 | andi. r0,r6,MSR_EE | |
638 | 1: tdnei r0,0 | |
639 | .section __bug_table,"a" | |
640 | .llong 1b,__LINE__ + 0x1000000, 1f, 2f | |
641 | .previous | |
642 | .section .rodata,"a" | |
643 | 1: .asciz __FILE__ | |
644 | 2: .asciz "enter_rtas" | |
645 | .previous | |
646 | ||
647 | /* Unfortunately, the stack pointer and the MSR are also clobbered, | |
648 | * so they are saved in the PACA which allows us to restore | |
649 | * our original state after RTAS returns. | |
650 | */ | |
651 | std r1,PACAR1(r13) | |
652 | std r6,PACASAVEDMSR(r13) | |
653 | ||
654 | /* Setup our real return addr */ | |
e58c3495 DG |
655 | LOAD_REG_ADDR(r4,.rtas_return_loc) |
656 | clrldi r4,r4,2 /* convert to realmode address */ | |
9994a338 PM |
657 | mtlr r4 |
658 | ||
659 | li r0,0 | |
660 | ori r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_RI | |
661 | andc r0,r6,r0 | |
662 | ||
663 | li r9,1 | |
664 | rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG) | |
665 | ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP | |
666 | andc r6,r0,r9 | |
667 | ori r6,r6,MSR_RI | |
668 | sync /* disable interrupts so SRR0/1 */ | |
669 | mtmsrd r0 /* don't get trashed */ | |
670 | ||
e58c3495 | 671 | LOAD_REG_ADDR(r4, rtas) |
9994a338 PM |
672 | ld r5,RTASENTRY(r4) /* get the rtas->entry value */ |
673 | ld r4,RTASBASE(r4) /* get the rtas->base value */ | |
674 | ||
675 | mtspr SPRN_SRR0,r5 | |
676 | mtspr SPRN_SRR1,r6 | |
677 | rfid | |
678 | b . /* prevent speculative execution */ | |
679 | ||
680 | _STATIC(rtas_return_loc) | |
681 | /* relocation is off at this point */ | |
682 | mfspr r4,SPRN_SPRG3 /* Get PACA */ | |
e58c3495 | 683 | clrldi r4,r4,2 /* convert to realmode address */ |
9994a338 PM |
684 | |
685 | mfmsr r6 | |
686 | li r0,MSR_RI | |
687 | andc r6,r6,r0 | |
688 | sync | |
689 | mtmsrd r6 | |
690 | ||
691 | ld r1,PACAR1(r4) /* Restore our SP */ | |
e58c3495 | 692 | LOAD_REG_IMMEDIATE(r3,.rtas_restore_regs) |
9994a338 PM |
693 | ld r4,PACASAVEDMSR(r4) /* Restore our MSR */ |
694 | ||
695 | mtspr SPRN_SRR0,r3 | |
696 | mtspr SPRN_SRR1,r4 | |
697 | rfid | |
698 | b . /* prevent speculative execution */ | |
699 | ||
700 | _STATIC(rtas_restore_regs) | |
701 | /* relocation is on at this point */ | |
702 | REST_GPR(2, r1) /* Restore the TOC */ | |
703 | REST_GPR(13, r1) /* Restore paca */ | |
704 | REST_8GPRS(14, r1) /* Restore the non-volatiles */ | |
705 | REST_10GPRS(22, r1) /* ditto */ | |
706 | ||
707 | mfspr r13,SPRN_SPRG3 | |
708 | ||
709 | ld r4,_CCR(r1) | |
710 | mtcr r4 | |
711 | ld r5,_CTR(r1) | |
712 | mtctr r5 | |
713 | ld r6,_XER(r1) | |
714 | mtspr SPRN_XER,r6 | |
715 | ld r7,_DAR(r1) | |
716 | mtdar r7 | |
717 | ld r8,_DSISR(r1) | |
718 | mtdsisr r8 | |
719 | ld r9,_SRR0(r1) | |
720 | mtsrr0 r9 | |
721 | ld r10,_SRR1(r1) | |
722 | mtsrr1 r10 | |
723 | ||
724 | addi r1,r1,RTAS_FRAME_SIZE /* Unstack our frame */ | |
725 | ld r0,16(r1) /* get return address */ | |
726 | ||
727 | mtlr r0 | |
728 | blr /* return to caller */ | |
729 | ||
730 | #endif /* CONFIG_PPC_RTAS */ | |
731 | ||
732 | #ifdef CONFIG_PPC_MULTIPLATFORM | |
733 | ||
734 | _GLOBAL(enter_prom) | |
735 | mflr r0 | |
736 | std r0,16(r1) | |
737 | stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */ | |
738 | ||
739 | /* Because PROM is running in 32b mode, it clobbers the high order half | |
740 | * of all registers that it saves. We therefore save those registers | |
741 | * PROM might touch to the stack. (r0, r3-r13 are caller saved) | |
742 | */ | |
743 | SAVE_8GPRS(2, r1) | |
744 | SAVE_GPR(13, r1) | |
745 | SAVE_8GPRS(14, r1) | |
746 | SAVE_10GPRS(22, r1) | |
747 | mfcr r4 | |
748 | std r4,_CCR(r1) | |
749 | mfctr r5 | |
750 | std r5,_CTR(r1) | |
751 | mfspr r6,SPRN_XER | |
752 | std r6,_XER(r1) | |
753 | mfdar r7 | |
754 | std r7,_DAR(r1) | |
755 | mfdsisr r8 | |
756 | std r8,_DSISR(r1) | |
757 | mfsrr0 r9 | |
758 | std r9,_SRR0(r1) | |
759 | mfsrr1 r10 | |
760 | std r10,_SRR1(r1) | |
761 | mfmsr r11 | |
762 | std r11,_MSR(r1) | |
763 | ||
764 | /* Get the PROM entrypoint */ | |
765 | ld r0,GPR4(r1) | |
766 | mtlr r0 | |
767 | ||
768 | /* Switch MSR to 32 bits mode | |
769 | */ | |
770 | mfmsr r11 | |
771 | li r12,1 | |
772 | rldicr r12,r12,MSR_SF_LG,(63-MSR_SF_LG) | |
773 | andc r11,r11,r12 | |
774 | li r12,1 | |
775 | rldicr r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG) | |
776 | andc r11,r11,r12 | |
777 | mtmsrd r11 | |
778 | isync | |
779 | ||
780 | /* Restore arguments & enter PROM here... */ | |
781 | ld r3,GPR3(r1) | |
782 | blrl | |
783 | ||
784 | /* Just make sure that r1 top 32 bits didn't get | |
785 | * corrupt by OF | |
786 | */ | |
787 | rldicl r1,r1,0,32 | |
788 | ||
789 | /* Restore the MSR (back to 64 bits) */ | |
790 | ld r0,_MSR(r1) | |
791 | mtmsrd r0 | |
792 | isync | |
793 | ||
794 | /* Restore other registers */ | |
795 | REST_GPR(2, r1) | |
796 | REST_GPR(13, r1) | |
797 | REST_8GPRS(14, r1) | |
798 | REST_10GPRS(22, r1) | |
799 | ld r4,_CCR(r1) | |
800 | mtcr r4 | |
801 | ld r5,_CTR(r1) | |
802 | mtctr r5 | |
803 | ld r6,_XER(r1) | |
804 | mtspr SPRN_XER,r6 | |
805 | ld r7,_DAR(r1) | |
806 | mtdar r7 | |
807 | ld r8,_DSISR(r1) | |
808 | mtdsisr r8 | |
809 | ld r9,_SRR0(r1) | |
810 | mtsrr0 r9 | |
811 | ld r10,_SRR1(r1) | |
812 | mtsrr1 r10 | |
813 | ||
814 | addi r1,r1,PROM_FRAME_SIZE | |
815 | ld r0,16(r1) | |
816 | mtlr r0 | |
817 | blr | |
818 | ||
819 | #endif /* CONFIG_PPC_MULTIPLATFORM */ |