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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> | |
3f639ee8 | 30 | #include <asm/firmware.h> |
007d88d0 | 31 | #include <asm/bug.h> |
ec2b36b9 | 32 | #include <asm/ptrace.h> |
945feb17 | 33 | #include <asm/irqflags.h> |
395a59d0 | 34 | #include <asm/ftrace.h> |
9994a338 PM |
35 | |
36 | /* | |
37 | * System calls. | |
38 | */ | |
39 | .section ".toc","aw" | |
40 | .SYS_CALL_TABLE: | |
41 | .tc .sys_call_table[TC],.sys_call_table | |
42 | ||
43 | /* This value is used to mark exception frames on the stack. */ | |
44 | exception_marker: | |
ec2b36b9 | 45 | .tc ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER |
9994a338 PM |
46 | |
47 | .section ".text" | |
48 | .align 7 | |
49 | ||
50 | #undef SHOW_SYSCALLS | |
51 | ||
52 | .globl system_call_common | |
53 | system_call_common: | |
54 | andi. r10,r12,MSR_PR | |
55 | mr r10,r1 | |
56 | addi r1,r1,-INT_FRAME_SIZE | |
57 | beq- 1f | |
58 | ld r1,PACAKSAVE(r13) | |
59 | 1: std r10,0(r1) | |
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) |
ab598b66 PM |
65 | /* |
66 | * This "crclr so" clears CR0.SO, which is the error indication on | |
67 | * return from this system call. There must be no cmp instruction | |
68 | * between it and the "mfcr r9" below, otherwise if XER.SO is set, | |
69 | * CR0.SO will get set, causing all system calls to appear to fail. | |
70 | */ | |
71 | crclr so | |
9994a338 PM |
72 | std r2,GPR2(r1) |
73 | std r3,GPR3(r1) | |
74 | std r4,GPR4(r1) | |
75 | std r5,GPR5(r1) | |
76 | std r6,GPR6(r1) | |
77 | std r7,GPR7(r1) | |
78 | std r8,GPR8(r1) | |
79 | li r11,0 | |
80 | std r11,GPR9(r1) | |
81 | std r11,GPR10(r1) | |
82 | std r11,GPR11(r1) | |
83 | std r11,GPR12(r1) | |
84 | std r9,GPR13(r1) | |
9994a338 PM |
85 | mfcr r9 |
86 | mflr r10 | |
87 | li r11,0xc01 | |
88 | std r9,_CCR(r1) | |
89 | std r10,_LINK(r1) | |
90 | std r11,_TRAP(r1) | |
91 | mfxer r9 | |
92 | mfctr r10 | |
93 | std r9,_XER(r1) | |
94 | std r10,_CTR(r1) | |
95 | std r3,ORIG_GPR3(r1) | |
96 | ld r2,PACATOC(r13) | |
97 | addi r9,r1,STACK_FRAME_OVERHEAD | |
98 | ld r11,exception_marker@toc(r2) | |
99 | std r11,-16(r9) /* "regshere" marker */ | |
945feb17 BH |
100 | #ifdef CONFIG_TRACE_IRQFLAGS |
101 | bl .trace_hardirqs_on | |
102 | REST_GPR(0,r1) | |
103 | REST_4GPRS(3,r1) | |
104 | REST_2GPRS(7,r1) | |
105 | addi r9,r1,STACK_FRAME_OVERHEAD | |
106 | ld r12,_MSR(r1) | |
107 | #endif /* CONFIG_TRACE_IRQFLAGS */ | |
d04c56f7 PM |
108 | li r10,1 |
109 | stb r10,PACASOFTIRQEN(r13) | |
110 | stb r10,PACAHARDIRQEN(r13) | |
111 | std r10,SOFTE(r1) | |
9994a338 | 112 | #ifdef CONFIG_PPC_ISERIES |
3f639ee8 | 113 | BEGIN_FW_FTR_SECTION |
9994a338 PM |
114 | /* Hack for handling interrupts when soft-enabling on iSeries */ |
115 | cmpdi cr1,r0,0x5555 /* syscall 0x5555 */ | |
116 | andi. r10,r12,MSR_PR /* from kernel */ | |
117 | crand 4*cr0+eq,4*cr1+eq,4*cr0+eq | |
c705677e SR |
118 | bne 2f |
119 | b hardware_interrupt_entry | |
120 | 2: | |
3f639ee8 | 121 | END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES) |
945feb17 | 122 | #endif /* CONFIG_PPC_ISERIES */ |
9994a338 PM |
123 | mfmsr r11 |
124 | ori r11,r11,MSR_EE | |
125 | mtmsrd r11,1 | |
126 | ||
127 | #ifdef SHOW_SYSCALLS | |
128 | bl .do_show_syscall | |
129 | REST_GPR(0,r1) | |
130 | REST_4GPRS(3,r1) | |
131 | REST_2GPRS(7,r1) | |
132 | addi r9,r1,STACK_FRAME_OVERHEAD | |
133 | #endif | |
134 | clrrdi r11,r1,THREAD_SHIFT | |
9994a338 | 135 | ld r10,TI_FLAGS(r11) |
9994a338 PM |
136 | andi. r11,r10,_TIF_SYSCALL_T_OR_A |
137 | bne- syscall_dotrace | |
138 | syscall_dotrace_cont: | |
139 | cmpldi 0,r0,NR_syscalls | |
140 | bge- syscall_enosys | |
141 | ||
142 | system_call: /* label this so stack traces look sane */ | |
143 | /* | |
144 | * Need to vector to 32 Bit or default sys_call_table here, | |
145 | * based on caller's run-mode / personality. | |
146 | */ | |
147 | ld r11,.SYS_CALL_TABLE@toc(2) | |
148 | andi. r10,r10,_TIF_32BIT | |
149 | beq 15f | |
150 | addi r11,r11,8 /* use 32-bit syscall entries */ | |
151 | clrldi r3,r3,32 | |
152 | clrldi r4,r4,32 | |
153 | clrldi r5,r5,32 | |
154 | clrldi r6,r6,32 | |
155 | clrldi r7,r7,32 | |
156 | clrldi r8,r8,32 | |
157 | 15: | |
158 | slwi r0,r0,4 | |
159 | ldx r10,r11,r0 /* Fetch system call handler [ptr] */ | |
160 | mtctr r10 | |
161 | bctrl /* Call handler */ | |
162 | ||
163 | syscall_exit: | |
401d1f02 | 164 | std r3,RESULT(r1) |
9994a338 | 165 | #ifdef SHOW_SYSCALLS |
9994a338 | 166 | bl .do_show_syscall_exit |
401d1f02 | 167 | ld r3,RESULT(r1) |
9994a338 | 168 | #endif |
9994a338 | 169 | clrrdi r12,r1,THREAD_SHIFT |
9994a338 PM |
170 | |
171 | /* disable interrupts so current_thread_info()->flags can't change, | |
172 | and so that we don't get interrupted after loading SRR0/1. */ | |
173 | ld r8,_MSR(r1) | |
174 | andi. r10,r8,MSR_RI | |
175 | beq- unrecov_restore | |
176 | mfmsr r10 | |
177 | rldicl r10,r10,48,1 | |
178 | rotldi r10,r10,16 | |
179 | mtmsrd r10,1 | |
180 | ld r9,TI_FLAGS(r12) | |
401d1f02 | 181 | li r11,-_LAST_ERRNO |
1bd79336 | 182 | andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK) |
9994a338 | 183 | bne- syscall_exit_work |
401d1f02 DW |
184 | cmpld r3,r11 |
185 | ld r5,_CCR(r1) | |
186 | bge- syscall_error | |
187 | syscall_error_cont: | |
9994a338 PM |
188 | ld r7,_NIP(r1) |
189 | stdcx. r0,0,r1 /* to clear the reservation */ | |
190 | andi. r6,r8,MSR_PR | |
191 | ld r4,_LINK(r1) | |
e56a6e20 PM |
192 | /* |
193 | * Clear RI before restoring r13. If we are returning to | |
194 | * userspace and we take an exception after restoring r13, | |
195 | * we end up corrupting the userspace r13 value. | |
196 | */ | |
197 | li r12,MSR_RI | |
198 | andc r11,r10,r12 | |
199 | mtmsrd r11,1 /* clear MSR.RI */ | |
c6622f63 PM |
200 | beq- 1f |
201 | ACCOUNT_CPU_USER_EXIT(r11, r12) | |
202 | ld r13,GPR13(r1) /* only restore r13 if returning to usermode */ | |
9994a338 | 203 | 1: ld r2,GPR2(r1) |
9994a338 PM |
204 | ld r1,GPR1(r1) |
205 | mtlr r4 | |
206 | mtcr r5 | |
207 | mtspr SPRN_SRR0,r7 | |
208 | mtspr SPRN_SRR1,r8 | |
209 | rfid | |
210 | b . /* prevent speculative execution */ | |
211 | ||
401d1f02 | 212 | syscall_error: |
9994a338 | 213 | oris r5,r5,0x1000 /* Set SO bit in CR */ |
401d1f02 | 214 | neg r3,r3 |
9994a338 PM |
215 | std r5,_CCR(r1) |
216 | b syscall_error_cont | |
401d1f02 | 217 | |
9994a338 PM |
218 | /* Traced system call support */ |
219 | syscall_dotrace: | |
220 | bl .save_nvgprs | |
221 | addi r3,r1,STACK_FRAME_OVERHEAD | |
222 | bl .do_syscall_trace_enter | |
4f72c427 RM |
223 | /* |
224 | * Restore argument registers possibly just changed. | |
225 | * We use the return value of do_syscall_trace_enter | |
226 | * for the call number to look up in the table (r0). | |
227 | */ | |
228 | mr r0,r3 | |
9994a338 PM |
229 | ld r3,GPR3(r1) |
230 | ld r4,GPR4(r1) | |
231 | ld r5,GPR5(r1) | |
232 | ld r6,GPR6(r1) | |
233 | ld r7,GPR7(r1) | |
234 | ld r8,GPR8(r1) | |
235 | addi r9,r1,STACK_FRAME_OVERHEAD | |
236 | clrrdi r10,r1,THREAD_SHIFT | |
237 | ld r10,TI_FLAGS(r10) | |
238 | b syscall_dotrace_cont | |
239 | ||
401d1f02 DW |
240 | syscall_enosys: |
241 | li r3,-ENOSYS | |
242 | b syscall_exit | |
243 | ||
244 | syscall_exit_work: | |
245 | /* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr. | |
246 | If TIF_NOERROR is set, just save r3 as it is. */ | |
247 | ||
248 | andi. r0,r9,_TIF_RESTOREALL | |
1bd79336 PM |
249 | beq+ 0f |
250 | REST_NVGPRS(r1) | |
251 | b 2f | |
252 | 0: cmpld r3,r11 /* r10 is -LAST_ERRNO */ | |
401d1f02 DW |
253 | blt+ 1f |
254 | andi. r0,r9,_TIF_NOERROR | |
255 | bne- 1f | |
256 | ld r5,_CCR(r1) | |
257 | neg r3,r3 | |
258 | oris r5,r5,0x1000 /* Set SO bit in CR */ | |
259 | std r5,_CCR(r1) | |
260 | 1: std r3,GPR3(r1) | |
261 | 2: andi. r0,r9,(_TIF_PERSYSCALL_MASK) | |
262 | beq 4f | |
263 | ||
1bd79336 | 264 | /* Clear per-syscall TIF flags if any are set. */ |
401d1f02 DW |
265 | |
266 | li r11,_TIF_PERSYSCALL_MASK | |
267 | addi r12,r12,TI_FLAGS | |
268 | 3: ldarx r10,0,r12 | |
269 | andc r10,r10,r11 | |
270 | stdcx. r10,0,r12 | |
271 | bne- 3b | |
272 | subi r12,r12,TI_FLAGS | |
1bd79336 PM |
273 | |
274 | 4: /* Anything else left to do? */ | |
275 | andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP) | |
401d1f02 DW |
276 | beq .ret_from_except_lite |
277 | ||
278 | /* Re-enable interrupts */ | |
279 | mfmsr r10 | |
280 | ori r10,r10,MSR_EE | |
281 | mtmsrd r10,1 | |
282 | ||
1bd79336 | 283 | bl .save_nvgprs |
9994a338 PM |
284 | addi r3,r1,STACK_FRAME_OVERHEAD |
285 | bl .do_syscall_trace_leave | |
1bd79336 | 286 | b .ret_from_except |
9994a338 PM |
287 | |
288 | /* Save non-volatile GPRs, if not already saved. */ | |
289 | _GLOBAL(save_nvgprs) | |
290 | ld r11,_TRAP(r1) | |
291 | andi. r0,r11,1 | |
292 | beqlr- | |
293 | SAVE_NVGPRS(r1) | |
294 | clrrdi r0,r11,1 | |
295 | std r0,_TRAP(r1) | |
296 | blr | |
297 | ||
401d1f02 | 298 | |
9994a338 PM |
299 | /* |
300 | * The sigsuspend and rt_sigsuspend system calls can call do_signal | |
301 | * and thus put the process into the stopped state where we might | |
302 | * want to examine its user state with ptrace. Therefore we need | |
303 | * to save all the nonvolatile registers (r14 - r31) before calling | |
304 | * the C code. Similarly, fork, vfork and clone need the full | |
305 | * register state on the stack so that it can be copied to the child. | |
306 | */ | |
9994a338 PM |
307 | |
308 | _GLOBAL(ppc_fork) | |
309 | bl .save_nvgprs | |
310 | bl .sys_fork | |
311 | b syscall_exit | |
312 | ||
313 | _GLOBAL(ppc_vfork) | |
314 | bl .save_nvgprs | |
315 | bl .sys_vfork | |
316 | b syscall_exit | |
317 | ||
318 | _GLOBAL(ppc_clone) | |
319 | bl .save_nvgprs | |
320 | bl .sys_clone | |
321 | b syscall_exit | |
322 | ||
1bd79336 PM |
323 | _GLOBAL(ppc32_swapcontext) |
324 | bl .save_nvgprs | |
325 | bl .compat_sys_swapcontext | |
326 | b syscall_exit | |
327 | ||
328 | _GLOBAL(ppc64_swapcontext) | |
329 | bl .save_nvgprs | |
330 | bl .sys_swapcontext | |
331 | b syscall_exit | |
332 | ||
9994a338 PM |
333 | _GLOBAL(ret_from_fork) |
334 | bl .schedule_tail | |
335 | REST_NVGPRS(r1) | |
336 | li r3,0 | |
337 | b syscall_exit | |
338 | ||
339 | /* | |
340 | * This routine switches between two different tasks. The process | |
341 | * state of one is saved on its kernel stack. Then the state | |
342 | * of the other is restored from its kernel stack. The memory | |
343 | * management hardware is updated to the second process's state. | |
344 | * Finally, we can return to the second process, via ret_from_except. | |
345 | * On entry, r3 points to the THREAD for the current task, r4 | |
346 | * points to the THREAD for the new task. | |
347 | * | |
348 | * Note: there are two ways to get to the "going out" portion | |
349 | * of this code; either by coming in via the entry (_switch) | |
350 | * or via "fork" which must set up an environment equivalent | |
351 | * to the "_switch" path. If you change this you'll have to change | |
352 | * the fork code also. | |
353 | * | |
354 | * The code which creates the new task context is in 'copy_thread' | |
2ef9481e | 355 | * in arch/powerpc/kernel/process.c |
9994a338 PM |
356 | */ |
357 | .align 7 | |
358 | _GLOBAL(_switch) | |
359 | mflr r0 | |
360 | std r0,16(r1) | |
361 | stdu r1,-SWITCH_FRAME_SIZE(r1) | |
362 | /* r3-r13 are caller saved -- Cort */ | |
363 | SAVE_8GPRS(14, r1) | |
364 | SAVE_10GPRS(22, r1) | |
365 | mflr r20 /* Return to switch caller */ | |
366 | mfmsr r22 | |
367 | li r0, MSR_FP | |
ce48b210 MN |
368 | #ifdef CONFIG_VSX |
369 | BEGIN_FTR_SECTION | |
370 | oris r0,r0,MSR_VSX@h /* Disable VSX */ | |
371 | END_FTR_SECTION_IFSET(CPU_FTR_VSX) | |
372 | #endif /* CONFIG_VSX */ | |
9994a338 PM |
373 | #ifdef CONFIG_ALTIVEC |
374 | BEGIN_FTR_SECTION | |
375 | oris r0,r0,MSR_VEC@h /* Disable altivec */ | |
376 | mfspr r24,SPRN_VRSAVE /* save vrsave register value */ | |
377 | std r24,THREAD_VRSAVE(r3) | |
378 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) | |
379 | #endif /* CONFIG_ALTIVEC */ | |
380 | and. r0,r0,r22 | |
381 | beq+ 1f | |
382 | andc r22,r22,r0 | |
383 | mtmsrd r22 | |
384 | isync | |
385 | 1: std r20,_NIP(r1) | |
386 | mfcr r23 | |
387 | std r23,_CCR(r1) | |
388 | std r1,KSP(r3) /* Set old stack pointer */ | |
389 | ||
390 | #ifdef CONFIG_SMP | |
391 | /* We need a sync somewhere here to make sure that if the | |
392 | * previous task gets rescheduled on another CPU, it sees all | |
393 | * stores it has performed on this one. | |
394 | */ | |
395 | sync | |
396 | #endif /* CONFIG_SMP */ | |
397 | ||
398 | addi r6,r4,-THREAD /* Convert THREAD to 'current' */ | |
399 | std r6,PACACURRENT(r13) /* Set new 'current' */ | |
400 | ||
401 | ld r8,KSP(r4) /* new stack pointer */ | |
1189be65 | 402 | BEGIN_FTR_SECTION |
c230328d | 403 | BEGIN_FTR_SECTION_NESTED(95) |
9994a338 PM |
404 | clrrdi r6,r8,28 /* get its ESID */ |
405 | clrrdi r9,r1,28 /* get current sp ESID */ | |
c230328d | 406 | FTR_SECTION_ELSE_NESTED(95) |
1189be65 PM |
407 | clrrdi r6,r8,40 /* get its 1T ESID */ |
408 | clrrdi r9,r1,40 /* get current sp 1T ESID */ | |
c230328d ME |
409 | ALT_FTR_SECTION_END_NESTED_IFCLR(CPU_FTR_1T_SEGMENT, 95) |
410 | FTR_SECTION_ELSE | |
411 | b 2f | |
412 | ALT_FTR_SECTION_END_IFSET(CPU_FTR_SLB) | |
9994a338 PM |
413 | clrldi. r0,r6,2 /* is new ESID c00000000? */ |
414 | cmpd cr1,r6,r9 /* or is new ESID the same as current ESID? */ | |
415 | cror eq,4*cr1+eq,eq | |
416 | beq 2f /* if yes, don't slbie it */ | |
417 | ||
418 | /* Bolt in the new stack SLB entry */ | |
419 | ld r7,KSP_VSID(r4) /* Get new stack's VSID */ | |
420 | oris r0,r6,(SLB_ESID_V)@h | |
421 | ori r0,r0,(SLB_NUM_BOLTED-1)@l | |
1189be65 PM |
422 | BEGIN_FTR_SECTION |
423 | li r9,MMU_SEGSIZE_1T /* insert B field */ | |
424 | oris r6,r6,(MMU_SEGSIZE_1T << SLBIE_SSIZE_SHIFT)@h | |
425 | rldimi r7,r9,SLB_VSID_SSIZE_SHIFT,0 | |
426 | END_FTR_SECTION_IFSET(CPU_FTR_1T_SEGMENT) | |
2f6093c8 | 427 | |
00efee7d MN |
428 | /* Update the last bolted SLB. No write barriers are needed |
429 | * here, provided we only update the current CPU's SLB shadow | |
430 | * buffer. | |
431 | */ | |
2f6093c8 | 432 | ld r9,PACA_SLBSHADOWPTR(r13) |
11a27ad7 MN |
433 | li r12,0 |
434 | std r12,SLBSHADOW_STACKESID(r9) /* Clear ESID */ | |
435 | std r7,SLBSHADOW_STACKVSID(r9) /* Save VSID */ | |
436 | std r0,SLBSHADOW_STACKESID(r9) /* Save ESID */ | |
2f6093c8 | 437 | |
f66bce5e OJ |
438 | /* No need to check for CPU_FTR_NO_SLBIE_B here, since when |
439 | * we have 1TB segments, the only CPUs known to have the errata | |
440 | * only support less than 1TB of system memory and we'll never | |
441 | * actually hit this code path. | |
442 | */ | |
443 | ||
9994a338 PM |
444 | slbie r6 |
445 | slbie r6 /* Workaround POWER5 < DD2.1 issue */ | |
446 | slbmte r7,r0 | |
447 | isync | |
448 | ||
449 | 2: | |
9994a338 PM |
450 | clrrdi r7,r8,THREAD_SHIFT /* base of new stack */ |
451 | /* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE | |
452 | because we don't need to leave the 288-byte ABI gap at the | |
453 | top of the kernel stack. */ | |
454 | addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE | |
455 | ||
456 | mr r1,r8 /* start using new stack pointer */ | |
457 | std r7,PACAKSAVE(r13) | |
458 | ||
459 | ld r6,_CCR(r1) | |
460 | mtcrf 0xFF,r6 | |
461 | ||
462 | #ifdef CONFIG_ALTIVEC | |
463 | BEGIN_FTR_SECTION | |
464 | ld r0,THREAD_VRSAVE(r4) | |
465 | mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */ | |
466 | END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC) | |
467 | #endif /* CONFIG_ALTIVEC */ | |
468 | ||
469 | /* r3-r13 are destroyed -- Cort */ | |
470 | REST_8GPRS(14, r1) | |
471 | REST_10GPRS(22, r1) | |
472 | ||
473 | /* convert old thread to its task_struct for return value */ | |
474 | addi r3,r3,-THREAD | |
475 | ld r7,_NIP(r1) /* Return to _switch caller in new task */ | |
476 | mtlr r7 | |
477 | addi r1,r1,SWITCH_FRAME_SIZE | |
478 | blr | |
479 | ||
480 | .align 7 | |
481 | _GLOBAL(ret_from_except) | |
482 | ld r11,_TRAP(r1) | |
483 | andi. r0,r11,1 | |
484 | bne .ret_from_except_lite | |
485 | REST_NVGPRS(r1) | |
486 | ||
487 | _GLOBAL(ret_from_except_lite) | |
488 | /* | |
489 | * Disable interrupts so that current_thread_info()->flags | |
490 | * can't change between when we test it and when we return | |
491 | * from the interrupt. | |
492 | */ | |
493 | mfmsr r10 /* Get current interrupt state */ | |
494 | rldicl r9,r10,48,1 /* clear MSR_EE */ | |
495 | rotldi r9,r9,16 | |
496 | mtmsrd r9,1 /* Update machine state */ | |
497 | ||
498 | #ifdef CONFIG_PREEMPT | |
499 | clrrdi r9,r1,THREAD_SHIFT /* current_thread_info() */ | |
500 | li r0,_TIF_NEED_RESCHED /* bits to check */ | |
501 | ld r3,_MSR(r1) | |
502 | ld r4,TI_FLAGS(r9) | |
503 | /* Move MSR_PR bit in r3 to _TIF_SIGPENDING position in r0 */ | |
504 | rlwimi r0,r3,32+TIF_SIGPENDING-MSR_PR_LG,_TIF_SIGPENDING | |
505 | and. r0,r4,r0 /* check NEED_RESCHED and maybe SIGPENDING */ | |
506 | bne do_work | |
507 | ||
508 | #else /* !CONFIG_PREEMPT */ | |
509 | ld r3,_MSR(r1) /* Returning to user mode? */ | |
510 | andi. r3,r3,MSR_PR | |
511 | beq restore /* if not, just restore regs and return */ | |
512 | ||
513 | /* Check current_thread_info()->flags */ | |
514 | clrrdi r9,r1,THREAD_SHIFT | |
515 | ld r4,TI_FLAGS(r9) | |
516 | andi. r0,r4,_TIF_USER_WORK_MASK | |
517 | bne do_work | |
518 | #endif | |
519 | ||
520 | restore: | |
3f639ee8 | 521 | BEGIN_FW_FTR_SECTION |
01f3880d ME |
522 | ld r5,SOFTE(r1) |
523 | FW_FTR_SECTION_ELSE | |
524 | b iseries_check_pending_irqs | |
525 | ALT_FW_FTR_SECTION_END_IFCLR(FW_FEATURE_ISERIES) | |
526 | 2: | |
945feb17 | 527 | TRACE_AND_RESTORE_IRQ(r5); |
9994a338 | 528 | |
e56a6e20 | 529 | /* extract EE bit and use it to restore paca->hard_enabled */ |
9994a338 | 530 | ld r3,_MSR(r1) |
e56a6e20 PM |
531 | rldicl r4,r3,49,63 /* r0 = (r3 >> 15) & 1 */ |
532 | stb r4,PACAHARDIRQEN(r13) | |
533 | ||
534 | ld r4,_CTR(r1) | |
535 | ld r0,_LINK(r1) | |
536 | mtctr r4 | |
537 | mtlr r0 | |
538 | ld r4,_XER(r1) | |
539 | mtspr SPRN_XER,r4 | |
540 | ||
541 | REST_8GPRS(5, r1) | |
542 | ||
9994a338 PM |
543 | andi. r0,r3,MSR_RI |
544 | beq- unrecov_restore | |
545 | ||
e56a6e20 | 546 | stdcx. r0,0,r1 /* to clear the reservation */ |
b0a779de | 547 | |
e56a6e20 PM |
548 | /* |
549 | * Clear RI before restoring r13. If we are returning to | |
550 | * userspace and we take an exception after restoring r13, | |
551 | * we end up corrupting the userspace r13 value. | |
552 | */ | |
553 | mfmsr r4 | |
554 | andc r4,r4,r0 /* r0 contains MSR_RI here */ | |
555 | mtmsrd r4,1 | |
9994a338 PM |
556 | |
557 | /* | |
558 | * r13 is our per cpu area, only restore it if we are returning to | |
559 | * userspace | |
560 | */ | |
e56a6e20 | 561 | andi. r0,r3,MSR_PR |
9994a338 | 562 | beq 1f |
e56a6e20 | 563 | ACCOUNT_CPU_USER_EXIT(r2, r4) |
9994a338 PM |
564 | REST_GPR(13, r1) |
565 | 1: | |
e56a6e20 | 566 | mtspr SPRN_SRR1,r3 |
9994a338 PM |
567 | |
568 | ld r2,_CCR(r1) | |
569 | mtcrf 0xFF,r2 | |
570 | ld r2,_NIP(r1) | |
571 | mtspr SPRN_SRR0,r2 | |
572 | ||
573 | ld r0,GPR0(r1) | |
574 | ld r2,GPR2(r1) | |
575 | ld r3,GPR3(r1) | |
576 | ld r4,GPR4(r1) | |
577 | ld r1,GPR1(r1) | |
578 | ||
579 | rfid | |
580 | b . /* prevent speculative execution */ | |
581 | ||
01f3880d ME |
582 | iseries_check_pending_irqs: |
583 | #ifdef CONFIG_PPC_ISERIES | |
584 | ld r5,SOFTE(r1) | |
585 | cmpdi 0,r5,0 | |
586 | beq 2b | |
587 | /* Check for pending interrupts (iSeries) */ | |
588 | ld r3,PACALPPACAPTR(r13) | |
589 | ld r3,LPPACAANYINT(r3) | |
590 | cmpdi r3,0 | |
591 | beq+ 2b /* skip do_IRQ if no interrupts */ | |
592 | ||
593 | li r3,0 | |
594 | stb r3,PACASOFTIRQEN(r13) /* ensure we are soft-disabled */ | |
595 | #ifdef CONFIG_TRACE_IRQFLAGS | |
596 | bl .trace_hardirqs_off | |
597 | mfmsr r10 | |
598 | #endif | |
599 | ori r10,r10,MSR_EE | |
600 | mtmsrd r10 /* hard-enable again */ | |
601 | addi r3,r1,STACK_FRAME_OVERHEAD | |
602 | bl .do_IRQ | |
603 | b .ret_from_except_lite /* loop back and handle more */ | |
604 | #endif | |
605 | ||
9994a338 PM |
606 | do_work: |
607 | #ifdef CONFIG_PREEMPT | |
608 | andi. r0,r3,MSR_PR /* Returning to user mode? */ | |
609 | bne user_work | |
610 | /* Check that preempt_count() == 0 and interrupts are enabled */ | |
611 | lwz r8,TI_PREEMPT(r9) | |
612 | cmpwi cr1,r8,0 | |
9994a338 PM |
613 | ld r0,SOFTE(r1) |
614 | cmpdi r0,0 | |
9994a338 PM |
615 | crandc eq,cr1*4+eq,eq |
616 | bne restore | |
617 | /* here we are preempting the current task */ | |
618 | 1: | |
945feb17 BH |
619 | #ifdef CONFIG_TRACE_IRQFLAGS |
620 | bl .trace_hardirqs_on | |
621 | /* Note: we just clobbered r10 which used to contain the previous | |
622 | * MSR before the hard-disabling done by the caller of do_work. | |
623 | * We don't have that value anymore, but it doesn't matter as | |
624 | * we will hard-enable unconditionally, we can just reload the | |
625 | * current MSR into r10 | |
626 | */ | |
627 | mfmsr r10 | |
628 | #endif /* CONFIG_TRACE_IRQFLAGS */ | |
9994a338 | 629 | li r0,1 |
d04c56f7 PM |
630 | stb r0,PACASOFTIRQEN(r13) |
631 | stb r0,PACAHARDIRQEN(r13) | |
9994a338 PM |
632 | ori r10,r10,MSR_EE |
633 | mtmsrd r10,1 /* reenable interrupts */ | |
634 | bl .preempt_schedule | |
635 | mfmsr r10 | |
636 | clrrdi r9,r1,THREAD_SHIFT | |
637 | rldicl r10,r10,48,1 /* disable interrupts again */ | |
638 | rotldi r10,r10,16 | |
639 | mtmsrd r10,1 | |
640 | ld r4,TI_FLAGS(r9) | |
641 | andi. r0,r4,_TIF_NEED_RESCHED | |
642 | bne 1b | |
643 | b restore | |
644 | ||
645 | user_work: | |
646 | #endif | |
647 | /* Enable interrupts */ | |
648 | ori r10,r10,MSR_EE | |
649 | mtmsrd r10,1 | |
650 | ||
651 | andi. r0,r4,_TIF_NEED_RESCHED | |
652 | beq 1f | |
653 | bl .schedule | |
654 | b .ret_from_except_lite | |
655 | ||
656 | 1: bl .save_nvgprs | |
7d6d637d | 657 | addi r3,r1,STACK_FRAME_OVERHEAD |
9994a338 PM |
658 | bl .do_signal |
659 | b .ret_from_except | |
660 | ||
661 | unrecov_restore: | |
662 | addi r3,r1,STACK_FRAME_OVERHEAD | |
663 | bl .unrecoverable_exception | |
664 | b unrecov_restore | |
665 | ||
666 | #ifdef CONFIG_PPC_RTAS | |
667 | /* | |
668 | * On CHRP, the Run-Time Abstraction Services (RTAS) have to be | |
669 | * called with the MMU off. | |
670 | * | |
671 | * In addition, we need to be in 32b mode, at least for now. | |
672 | * | |
673 | * Note: r3 is an input parameter to rtas, so don't trash it... | |
674 | */ | |
675 | _GLOBAL(enter_rtas) | |
676 | mflr r0 | |
677 | std r0,16(r1) | |
678 | stdu r1,-RTAS_FRAME_SIZE(r1) /* Save SP and create stack space. */ | |
679 | ||
680 | /* Because RTAS is running in 32b mode, it clobbers the high order half | |
681 | * of all registers that it saves. We therefore save those registers | |
682 | * RTAS might touch to the stack. (r0, r3-r13 are caller saved) | |
683 | */ | |
684 | SAVE_GPR(2, r1) /* Save the TOC */ | |
685 | SAVE_GPR(13, r1) /* Save paca */ | |
686 | SAVE_8GPRS(14, r1) /* Save the non-volatiles */ | |
687 | SAVE_10GPRS(22, r1) /* ditto */ | |
688 | ||
689 | mfcr r4 | |
690 | std r4,_CCR(r1) | |
691 | mfctr r5 | |
692 | std r5,_CTR(r1) | |
693 | mfspr r6,SPRN_XER | |
694 | std r6,_XER(r1) | |
695 | mfdar r7 | |
696 | std r7,_DAR(r1) | |
697 | mfdsisr r8 | |
698 | std r8,_DSISR(r1) | |
9994a338 | 699 | |
9fe901d1 MK |
700 | /* Temporary workaround to clear CR until RTAS can be modified to |
701 | * ignore all bits. | |
702 | */ | |
703 | li r0,0 | |
704 | mtcr r0 | |
705 | ||
007d88d0 | 706 | #ifdef CONFIG_BUG |
9994a338 PM |
707 | /* There is no way it is acceptable to get here with interrupts enabled, |
708 | * check it with the asm equivalent of WARN_ON | |
709 | */ | |
d04c56f7 | 710 | lbz r0,PACASOFTIRQEN(r13) |
9994a338 | 711 | 1: tdnei r0,0 |
007d88d0 DW |
712 | EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING |
713 | #endif | |
714 | ||
d04c56f7 PM |
715 | /* Hard-disable interrupts */ |
716 | mfmsr r6 | |
717 | rldicl r7,r6,48,1 | |
718 | rotldi r7,r7,16 | |
719 | mtmsrd r7,1 | |
720 | ||
9994a338 PM |
721 | /* Unfortunately, the stack pointer and the MSR are also clobbered, |
722 | * so they are saved in the PACA which allows us to restore | |
723 | * our original state after RTAS returns. | |
724 | */ | |
725 | std r1,PACAR1(r13) | |
726 | std r6,PACASAVEDMSR(r13) | |
727 | ||
728 | /* Setup our real return addr */ | |
e58c3495 DG |
729 | LOAD_REG_ADDR(r4,.rtas_return_loc) |
730 | clrldi r4,r4,2 /* convert to realmode address */ | |
9994a338 PM |
731 | mtlr r4 |
732 | ||
733 | li r0,0 | |
734 | ori r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_RI | |
735 | andc r0,r6,r0 | |
736 | ||
737 | li r9,1 | |
738 | rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG) | |
739 | ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP | |
740 | andc r6,r0,r9 | |
741 | ori r6,r6,MSR_RI | |
742 | sync /* disable interrupts so SRR0/1 */ | |
743 | mtmsrd r0 /* don't get trashed */ | |
744 | ||
e58c3495 | 745 | LOAD_REG_ADDR(r4, rtas) |
9994a338 PM |
746 | ld r5,RTASENTRY(r4) /* get the rtas->entry value */ |
747 | ld r4,RTASBASE(r4) /* get the rtas->base value */ | |
748 | ||
749 | mtspr SPRN_SRR0,r5 | |
750 | mtspr SPRN_SRR1,r6 | |
751 | rfid | |
752 | b . /* prevent speculative execution */ | |
753 | ||
754 | _STATIC(rtas_return_loc) | |
755 | /* relocation is off at this point */ | |
756 | mfspr r4,SPRN_SPRG3 /* Get PACA */ | |
e58c3495 | 757 | clrldi r4,r4,2 /* convert to realmode address */ |
9994a338 | 758 | |
e31aa453 PM |
759 | bcl 20,31,$+4 |
760 | 0: mflr r3 | |
761 | ld r3,(1f-0b)(r3) /* get &.rtas_restore_regs */ | |
762 | ||
9994a338 PM |
763 | mfmsr r6 |
764 | li r0,MSR_RI | |
765 | andc r6,r6,r0 | |
766 | sync | |
767 | mtmsrd r6 | |
768 | ||
769 | ld r1,PACAR1(r4) /* Restore our SP */ | |
9994a338 PM |
770 | ld r4,PACASAVEDMSR(r4) /* Restore our MSR */ |
771 | ||
772 | mtspr SPRN_SRR0,r3 | |
773 | mtspr SPRN_SRR1,r4 | |
774 | rfid | |
775 | b . /* prevent speculative execution */ | |
776 | ||
e31aa453 PM |
777 | .align 3 |
778 | 1: .llong .rtas_restore_regs | |
779 | ||
9994a338 PM |
780 | _STATIC(rtas_restore_regs) |
781 | /* relocation is on at this point */ | |
782 | REST_GPR(2, r1) /* Restore the TOC */ | |
783 | REST_GPR(13, r1) /* Restore paca */ | |
784 | REST_8GPRS(14, r1) /* Restore the non-volatiles */ | |
785 | REST_10GPRS(22, r1) /* ditto */ | |
786 | ||
787 | mfspr r13,SPRN_SPRG3 | |
788 | ||
789 | ld r4,_CCR(r1) | |
790 | mtcr r4 | |
791 | ld r5,_CTR(r1) | |
792 | mtctr r5 | |
793 | ld r6,_XER(r1) | |
794 | mtspr SPRN_XER,r6 | |
795 | ld r7,_DAR(r1) | |
796 | mtdar r7 | |
797 | ld r8,_DSISR(r1) | |
798 | mtdsisr r8 | |
9994a338 PM |
799 | |
800 | addi r1,r1,RTAS_FRAME_SIZE /* Unstack our frame */ | |
801 | ld r0,16(r1) /* get return address */ | |
802 | ||
803 | mtlr r0 | |
804 | blr /* return to caller */ | |
805 | ||
806 | #endif /* CONFIG_PPC_RTAS */ | |
807 | ||
9994a338 PM |
808 | _GLOBAL(enter_prom) |
809 | mflr r0 | |
810 | std r0,16(r1) | |
811 | stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */ | |
812 | ||
813 | /* Because PROM is running in 32b mode, it clobbers the high order half | |
814 | * of all registers that it saves. We therefore save those registers | |
815 | * PROM might touch to the stack. (r0, r3-r13 are caller saved) | |
816 | */ | |
817 | SAVE_8GPRS(2, r1) | |
818 | SAVE_GPR(13, r1) | |
819 | SAVE_8GPRS(14, r1) | |
820 | SAVE_10GPRS(22, r1) | |
821 | mfcr r4 | |
822 | std r4,_CCR(r1) | |
823 | mfctr r5 | |
824 | std r5,_CTR(r1) | |
825 | mfspr r6,SPRN_XER | |
826 | std r6,_XER(r1) | |
827 | mfdar r7 | |
828 | std r7,_DAR(r1) | |
829 | mfdsisr r8 | |
830 | std r8,_DSISR(r1) | |
831 | mfsrr0 r9 | |
832 | std r9,_SRR0(r1) | |
833 | mfsrr1 r10 | |
834 | std r10,_SRR1(r1) | |
835 | mfmsr r11 | |
836 | std r11,_MSR(r1) | |
837 | ||
838 | /* Get the PROM entrypoint */ | |
839 | ld r0,GPR4(r1) | |
840 | mtlr r0 | |
841 | ||
842 | /* Switch MSR to 32 bits mode | |
843 | */ | |
844 | mfmsr r11 | |
845 | li r12,1 | |
846 | rldicr r12,r12,MSR_SF_LG,(63-MSR_SF_LG) | |
847 | andc r11,r11,r12 | |
848 | li r12,1 | |
849 | rldicr r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG) | |
850 | andc r11,r11,r12 | |
851 | mtmsrd r11 | |
852 | isync | |
853 | ||
854 | /* Restore arguments & enter PROM here... */ | |
855 | ld r3,GPR3(r1) | |
856 | blrl | |
857 | ||
858 | /* Just make sure that r1 top 32 bits didn't get | |
859 | * corrupt by OF | |
860 | */ | |
861 | rldicl r1,r1,0,32 | |
862 | ||
863 | /* Restore the MSR (back to 64 bits) */ | |
864 | ld r0,_MSR(r1) | |
865 | mtmsrd r0 | |
866 | isync | |
867 | ||
868 | /* Restore other registers */ | |
869 | REST_GPR(2, r1) | |
870 | REST_GPR(13, r1) | |
871 | REST_8GPRS(14, r1) | |
872 | REST_10GPRS(22, r1) | |
873 | ld r4,_CCR(r1) | |
874 | mtcr r4 | |
875 | ld r5,_CTR(r1) | |
876 | mtctr r5 | |
877 | ld r6,_XER(r1) | |
878 | mtspr SPRN_XER,r6 | |
879 | ld r7,_DAR(r1) | |
880 | mtdar r7 | |
881 | ld r8,_DSISR(r1) | |
882 | mtdsisr r8 | |
883 | ld r9,_SRR0(r1) | |
884 | mtsrr0 r9 | |
885 | ld r10,_SRR1(r1) | |
886 | mtsrr1 r10 | |
887 | ||
888 | addi r1,r1,PROM_FRAME_SIZE | |
889 | ld r0,16(r1) | |
890 | mtlr r0 | |
891 | blr | |
4e491d14 | 892 | |
606576ce | 893 | #ifdef CONFIG_FUNCTION_TRACER |
4e491d14 SR |
894 | #ifdef CONFIG_DYNAMIC_FTRACE |
895 | _GLOBAL(mcount) | |
896 | _GLOBAL(_mcount) | |
897 | /* Taken from output of objdump from lib64/glibc */ | |
898 | mflr r3 | |
899 | stdu r1, -112(r1) | |
900 | std r3, 128(r1) | |
395a59d0 | 901 | subi r3, r3, MCOUNT_INSN_SIZE |
4e491d14 SR |
902 | .globl mcount_call |
903 | mcount_call: | |
904 | bl ftrace_stub | |
905 | nop | |
906 | ld r0, 128(r1) | |
907 | mtlr r0 | |
908 | addi r1, r1, 112 | |
909 | blr | |
910 | ||
911 | _GLOBAL(ftrace_caller) | |
912 | /* Taken from output of objdump from lib64/glibc */ | |
913 | mflr r3 | |
914 | ld r11, 0(r1) | |
915 | stdu r1, -112(r1) | |
916 | std r3, 128(r1) | |
917 | ld r4, 16(r11) | |
395a59d0 | 918 | subi r3, r3, MCOUNT_INSN_SIZE |
4e491d14 SR |
919 | .globl ftrace_call |
920 | ftrace_call: | |
921 | bl ftrace_stub | |
922 | nop | |
923 | ld r0, 128(r1) | |
924 | mtlr r0 | |
925 | addi r1, r1, 112 | |
926 | _GLOBAL(ftrace_stub) | |
927 | blr | |
928 | #else | |
929 | _GLOBAL(mcount) | |
930 | blr | |
931 | ||
932 | _GLOBAL(_mcount) | |
933 | /* Taken from output of objdump from lib64/glibc */ | |
934 | mflr r3 | |
935 | ld r11, 0(r1) | |
936 | stdu r1, -112(r1) | |
937 | std r3, 128(r1) | |
938 | ld r4, 16(r11) | |
939 | ||
395a59d0 | 940 | subi r3, r3, MCOUNT_INSN_SIZE |
4e491d14 SR |
941 | LOAD_REG_ADDR(r5,ftrace_trace_function) |
942 | ld r5,0(r5) | |
943 | ld r5,0(r5) | |
944 | mtctr r5 | |
945 | bctrl | |
946 | ||
947 | nop | |
948 | ld r0, 128(r1) | |
949 | mtlr r0 | |
950 | addi r1, r1, 112 | |
951 | _GLOBAL(ftrace_stub) | |
952 | blr | |
953 | ||
954 | #endif | |
955 | #endif |