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).
12 * This file contains the system call entry code, context switch
13 * code, and exception/interrupt return code for PowerPC.
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.
21 #include <linux/errno.h>
22 #include <asm/unistd.h>
23 #include <asm/processor.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 #include <asm/firmware.h>
32 #include <asm/ptrace.h>
33 #include <asm/irqflags.h>
34 #include <asm/ftrace.h>
35 #include <asm/hw_irq.h>
42 .tc .sys_call_table[TC],.sys_call_table
44 /* This value is used to mark exception frames on the stack. */
46 .tc ID_EXC_MARKER[TC],STACK_FRAME_REGS_MARKER
53 .globl system_call_common
57 addi r1,r1,-INT_FRAME_SIZE
65 beq 2f /* if from kernel mode */
66 ACCOUNT_CPU_USER_ENTRY(r10, r11)
85 * This clears CR0.SO (bit 28), which is the error indication on
86 * return from this system call.
88 rldimi r2,r11,28,(63-28)
95 addi r9,r1,STACK_FRAME_OVERHEAD
96 ld r11,exception_marker@toc(r2)
97 std r11,-16(r9) /* "regshere" marker */
98 #if defined(CONFIG_VIRT_CPU_ACCOUNTING_NATIVE) && defined(CONFIG_PPC_SPLPAR)
101 /* if from user, see if there are any DTL entries to process */
102 ld r10,PACALPPACAPTR(r13) /* get ptr to VPA */
103 ld r11,PACA_DTL_RIDX(r13) /* get log read index */
104 ld r10,LPPACA_DTLIDX(r10) /* get log write index */
107 bl .accumulate_stolen_time
111 addi r9,r1,STACK_FRAME_OVERHEAD
113 END_FW_FTR_SECTION_IFSET(FW_FEATURE_SPLPAR)
114 #endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE && CONFIG_PPC_SPLPAR */
117 * A syscall should always be called with interrupts enabled
118 * so we just unconditionally hard-enable here. When some kind
119 * of irq tracing is used, we additionally check that condition
122 #if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_BUG)
123 lbz r10,PACASOFTIRQEN(r13)
126 EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
129 #ifdef CONFIG_PPC_BOOK3E
135 #endif /* CONFIG_PPC_BOOK3E */
137 /* We do need to set SOFTE in the stack frame or the return
138 * from interrupt will be painful
148 addi r9,r1,STACK_FRAME_OVERHEAD
150 CURRENT_THREAD_INFO(r11, r1)
152 andi. r11,r10,_TIF_SYSCALL_T_OR_A
154 .Lsyscall_dotrace_cont:
155 cmpldi 0,r0,NR_syscalls
158 system_call: /* label this so stack traces look sane */
160 * Need to vector to 32 Bit or default sys_call_table here,
161 * based on caller's run-mode / personality.
163 ld r11,.SYS_CALL_TABLE@toc(2)
164 andi. r10,r10,_TIF_32BIT
166 addi r11,r11,8 /* use 32-bit syscall entries */
175 ldx r10,r11,r0 /* Fetch system call handler [ptr] */
177 bctrl /* Call handler */
182 bl .do_show_syscall_exit
185 CURRENT_THREAD_INFO(r12, r1)
188 #ifdef CONFIG_PPC_BOOK3S
189 /* No MSR:RI on BookE */
194 * Disable interrupts so current_thread_info()->flags can't change,
195 * and so that we don't get interrupted after loading SRR0/1.
197 #ifdef CONFIG_PPC_BOOK3E
202 * For performance reasons we clear RI the same time that we
203 * clear EE. We only need to clear RI just before we restore r13
204 * below, but batching it with EE saves us one expensive mtmsrd call.
205 * We have to be careful to restore RI if we branch anywhere from
206 * here (eg syscall_exit_work).
211 #endif /* CONFIG_PPC_BOOK3E */
215 andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
216 bne- syscall_exit_work
220 .Lsyscall_error_cont:
223 stdcx. r0,0,r1 /* to clear the reservation */
224 END_FTR_SECTION_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
229 ACCOUNT_CPU_USER_EXIT(r11, r12)
230 HMT_MEDIUM_LOW_HAS_PPR
231 ld r13,GPR13(r1) /* only restore r13 if returning to usermode */
239 b . /* prevent speculative execution */
242 oris r5,r5,0x1000 /* Set SO bit in CR */
245 b .Lsyscall_error_cont
247 /* Traced system call support */
250 addi r3,r1,STACK_FRAME_OVERHEAD
251 bl .do_syscall_trace_enter
253 * Restore argument registers possibly just changed.
254 * We use the return value of do_syscall_trace_enter
255 * for the call number to look up in the table (r0).
264 addi r9,r1,STACK_FRAME_OVERHEAD
265 CURRENT_THREAD_INFO(r10, r1)
267 b .Lsyscall_dotrace_cont
274 #ifdef CONFIG_PPC_BOOK3S
275 mtmsrd r10,1 /* Restore RI */
277 /* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr.
278 If TIF_NOERROR is set, just save r3 as it is. */
280 andi. r0,r9,_TIF_RESTOREALL
284 0: cmpld r3,r11 /* r10 is -LAST_ERRNO */
286 andi. r0,r9,_TIF_NOERROR
290 oris r5,r5,0x1000 /* Set SO bit in CR */
293 2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
296 /* Clear per-syscall TIF flags if any are set. */
298 li r11,_TIF_PERSYSCALL_MASK
299 addi r12,r12,TI_FLAGS
304 subi r12,r12,TI_FLAGS
306 4: /* Anything else left to do? */
307 SET_DEFAULT_THREAD_PPR(r3, r10) /* Set thread.ppr = 3 */
308 andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP)
309 beq .ret_from_except_lite
311 /* Re-enable interrupts */
312 #ifdef CONFIG_PPC_BOOK3E
318 #endif /* CONFIG_PPC_BOOK3E */
321 addi r3,r1,STACK_FRAME_OVERHEAD
322 bl .do_syscall_trace_leave
325 /* Save non-volatile GPRs, if not already saved. */
337 * The sigsuspend and rt_sigsuspend system calls can call do_signal
338 * and thus put the process into the stopped state where we might
339 * want to examine its user state with ptrace. Therefore we need
340 * to save all the nonvolatile registers (r14 - r31) before calling
341 * the C code. Similarly, fork, vfork and clone need the full
342 * register state on the stack so that it can be copied to the child.
360 _GLOBAL(ppc32_swapcontext)
362 bl .compat_sys_swapcontext
365 _GLOBAL(ppc64_swapcontext)
370 _GLOBAL(ret_from_fork)
376 _GLOBAL(ret_from_kernel_thread)
390 .tc dscr_default[TC],dscr_default
395 * This routine switches between two different tasks. The process
396 * state of one is saved on its kernel stack. Then the state
397 * of the other is restored from its kernel stack. The memory
398 * management hardware is updated to the second process's state.
399 * Finally, we can return to the second process, via ret_from_except.
400 * On entry, r3 points to the THREAD for the current task, r4
401 * points to the THREAD for the new task.
403 * Note: there are two ways to get to the "going out" portion
404 * of this code; either by coming in via the entry (_switch)
405 * or via "fork" which must set up an environment equivalent
406 * to the "_switch" path. If you change this you'll have to change
407 * the fork code also.
409 * The code which creates the new task context is in 'copy_thread'
410 * in arch/powerpc/kernel/process.c
416 stdu r1,-SWITCH_FRAME_SIZE(r1)
417 /* r3-r13 are caller saved -- Cort */
420 mflr r20 /* Return to switch caller */
425 oris r0,r0,MSR_VSX@h /* Disable VSX */
426 END_FTR_SECTION_IFSET(CPU_FTR_VSX)
427 #endif /* CONFIG_VSX */
428 #ifdef CONFIG_ALTIVEC
430 oris r0,r0,MSR_VEC@h /* Disable altivec */
431 mfspr r24,SPRN_VRSAVE /* save vrsave register value */
432 std r24,THREAD_VRSAVE(r3)
433 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
434 #endif /* CONFIG_ALTIVEC */
438 std r25,THREAD_DSCR(r3)
439 END_FTR_SECTION_IFSET(CPU_FTR_DSCR)
449 std r1,KSP(r3) /* Set old stack pointer */
451 #ifdef CONFIG_PPC_BOOK3S_64
454 * Back up the TAR across context switches. Note that the TAR is not
455 * available for use in the kernel. (To provide this, the TAR should
456 * be backed up/restored on exception entry/exit instead, and be in
457 * pt_regs. FIXME, this should be in pt_regs anyway (for debug).)
460 std r0,THREAD_TAR(r3)
462 /* Event based branch registers */
464 std r0, THREAD_BESCR(r3)
466 std r0, THREAD_EBBHR(r3)
468 std r0, THREAD_EBBRR(r3)
469 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
473 /* We need a sync somewhere here to make sure that if the
474 * previous task gets rescheduled on another CPU, it sees all
475 * stores it has performed on this one.
478 #endif /* CONFIG_SMP */
481 * If we optimise away the clear of the reservation in system
482 * calls because we know the CPU tracks the address of the
483 * reservation, then we need to clear it here to cover the
484 * case that the kernel context switch path has no larx
489 END_FTR_SECTION_IFSET(CPU_FTR_STCX_CHECKS_ADDRESS)
491 addi r6,r4,-THREAD /* Convert THREAD to 'current' */
492 std r6,PACACURRENT(r13) /* Set new 'current' */
494 ld r8,KSP(r4) /* new stack pointer */
495 #ifdef CONFIG_PPC_BOOK3S
497 BEGIN_FTR_SECTION_NESTED(95)
498 clrrdi r6,r8,28 /* get its ESID */
499 clrrdi r9,r1,28 /* get current sp ESID */
500 FTR_SECTION_ELSE_NESTED(95)
501 clrrdi r6,r8,40 /* get its 1T ESID */
502 clrrdi r9,r1,40 /* get current sp 1T ESID */
503 ALT_MMU_FTR_SECTION_END_NESTED_IFCLR(MMU_FTR_1T_SEGMENT, 95)
506 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_SLB)
507 clrldi. r0,r6,2 /* is new ESID c00000000? */
508 cmpd cr1,r6,r9 /* or is new ESID the same as current ESID? */
510 beq 2f /* if yes, don't slbie it */
512 /* Bolt in the new stack SLB entry */
513 ld r7,KSP_VSID(r4) /* Get new stack's VSID */
514 oris r0,r6,(SLB_ESID_V)@h
515 ori r0,r0,(SLB_NUM_BOLTED-1)@l
517 li r9,MMU_SEGSIZE_1T /* insert B field */
518 oris r6,r6,(MMU_SEGSIZE_1T << SLBIE_SSIZE_SHIFT)@h
519 rldimi r7,r9,SLB_VSID_SSIZE_SHIFT,0
520 END_MMU_FTR_SECTION_IFSET(MMU_FTR_1T_SEGMENT)
522 /* Update the last bolted SLB. No write barriers are needed
523 * here, provided we only update the current CPU's SLB shadow
526 ld r9,PACA_SLBSHADOWPTR(r13)
528 std r12,SLBSHADOW_STACKESID(r9) /* Clear ESID */
529 std r7,SLBSHADOW_STACKVSID(r9) /* Save VSID */
530 std r0,SLBSHADOW_STACKESID(r9) /* Save ESID */
532 /* No need to check for MMU_FTR_NO_SLBIE_B here, since when
533 * we have 1TB segments, the only CPUs known to have the errata
534 * only support less than 1TB of system memory and we'll never
535 * actually hit this code path.
539 slbie r6 /* Workaround POWER5 < DD2.1 issue */
543 #endif /* !CONFIG_PPC_BOOK3S */
545 CURRENT_THREAD_INFO(r7, r8) /* base of new stack */
546 /* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE
547 because we don't need to leave the 288-byte ABI gap at the
548 top of the kernel stack. */
549 addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE
551 mr r1,r8 /* start using new stack pointer */
552 std r7,PACAKSAVE(r13)
554 #ifdef CONFIG_PPC_BOOK3S_64
556 /* Event based branch registers */
557 ld r0, THREAD_BESCR(r4)
559 ld r0, THREAD_EBBHR(r4)
561 ld r0, THREAD_EBBRR(r4)
566 END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S)
569 #ifdef CONFIG_ALTIVEC
571 ld r0,THREAD_VRSAVE(r4)
572 mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */
573 END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
574 #endif /* CONFIG_ALTIVEC */
577 lwz r6,THREAD_DSCR_INHERIT(r4)
578 ld r7,DSCR_DEFAULT@toc(2)
579 ld r0,THREAD_DSCR(r4)
587 END_FTR_SECTION_IFSET(CPU_FTR_DSCR)
593 /* r3-r13 are destroyed -- Cort */
597 /* convert old thread to its task_struct for return value */
599 ld r7,_NIP(r1) /* Return to _switch caller in new task */
601 addi r1,r1,SWITCH_FRAME_SIZE
605 _GLOBAL(ret_from_except)
608 bne .ret_from_except_lite
611 _GLOBAL(ret_from_except_lite)
613 * Disable interrupts so that current_thread_info()->flags
614 * can't change between when we test it and when we return
615 * from the interrupt.
617 #ifdef CONFIG_PPC_BOOK3E
620 ld r10,PACAKMSR(r13) /* Get kernel MSR without EE */
621 mtmsrd r10,1 /* Update machine state */
622 #endif /* CONFIG_PPC_BOOK3E */
624 CURRENT_THREAD_INFO(r9, r1)
630 /* Check current_thread_info()->flags */
631 andi. r0,r4,_TIF_USER_WORK_MASK
634 andi. r0,r4,_TIF_NEED_RESCHED
636 bl .restore_interrupts
638 b .ret_from_except_lite
641 bl .restore_interrupts
642 addi r3,r1,STACK_FRAME_OVERHEAD
647 /* check current_thread_info, _TIF_EMULATE_STACK_STORE */
648 CURRENT_THREAD_INFO(r9, r1)
650 andis. r8,r8,_TIF_EMULATE_STACK_STORE@h
653 addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */
656 subi r3,r3,INT_FRAME_SIZE /* dst: Allocate a trampoline exception frame */
657 mr r4,r1 /* src: current exception frame */
658 mr r1,r3 /* Reroute the trampoline frame to r1 */
660 /* Copy from the original to the trampoline. */
661 li r5,INT_FRAME_SIZE/8 /* size: INT_FRAME_SIZE */
662 li r6,0 /* start offset: 0 */
669 /* Do real store operation to complete stwu */
673 /* Clear _TIF_EMULATE_STACK_STORE flag */
674 lis r11,_TIF_EMULATE_STACK_STORE@h
682 #ifdef CONFIG_PREEMPT
683 /* Check if we need to preempt */
684 andi. r0,r4,_TIF_NEED_RESCHED
686 /* Check that preempt_count() == 0 and interrupts are enabled */
687 lwz r8,TI_PREEMPT(r9)
691 crandc eq,cr1*4+eq,eq
695 * Here we are preempting the current task. We want to make
696 * sure we are soft-disabled first
698 SOFT_DISABLE_INTS(r3,r4)
699 1: bl .preempt_schedule_irq
701 /* Re-test flags and eventually loop */
702 CURRENT_THREAD_INFO(r9, r1)
704 andi. r0,r4,_TIF_NEED_RESCHED
708 * arch_local_irq_restore() from preempt_schedule_irq above may
709 * enable hard interrupt but we really should disable interrupts
710 * when we return from the interrupt, and so that we don't get
711 * interrupted after loading SRR0/1.
713 #ifdef CONFIG_PPC_BOOK3E
716 ld r10,PACAKMSR(r13) /* Get kernel MSR without EE */
717 mtmsrd r10,1 /* Update machine state */
718 #endif /* CONFIG_PPC_BOOK3E */
719 #endif /* CONFIG_PREEMPT */
721 .globl fast_exc_return_irq
725 * This is the main kernel exit path. First we check if we
726 * are about to re-enable interrupts
729 lbz r6,PACASOFTIRQEN(r13)
733 /* We are enabling, were we already enabled ? Yes, just return */
738 * We are about to soft-enable interrupts (we are hard disabled
739 * at this point). We check if there's anything that needs to
742 lbz r0,PACAIRQHAPPENED(r13)
744 bne- restore_check_irq_replay
747 * Get here when nothing happened while soft-disabled, just
748 * soft-enable and move-on. We will hard-enable as a side
754 stb r0,PACASOFTIRQEN(r13);
757 * Final return path. BookE is handled in a different file
760 #ifdef CONFIG_PPC_BOOK3E
761 b .exception_return_book3e
764 * Clear the reservation. If we know the CPU tracks the address of
765 * the reservation then we can potentially save some cycles and use
766 * a larx. On POWER6 and POWER7 this is significantly faster.
769 stdcx. r0,0,r1 /* to clear the reservation */
772 ALT_FTR_SECTION_END_IFCLR(CPU_FTR_STCX_CHECKS_ADDRESS)
775 * Some code path such as load_up_fpu or altivec return directly
776 * here. They run entirely hard disabled and do not alter the
777 * interrupt state. They also don't use lwarx/stwcx. and thus
778 * are known not to leave dangling reservations.
780 .globl fast_exception_return
781 fast_exception_return:
796 * Clear RI before restoring r13. If we are returning to
797 * userspace and we take an exception after restoring r13,
798 * we end up corrupting the userspace r13 value.
800 ld r4,PACAKMSR(r13) /* Get kernel MSR without EE */
801 andc r4,r4,r0 /* r0 contains MSR_RI here */
804 #ifdef CONFIG_PPC_TRANSACTIONAL_MEM
806 std r3, PACATMSCRATCH(r13) /* Stash returned-to MSR */
809 * r13 is our per cpu area, only restore it if we are returning to
810 * userspace the value stored in the stack frame may belong to
815 ACCOUNT_CPU_USER_EXIT(r2, r4)
833 b . /* prevent speculative execution */
835 #endif /* CONFIG_PPC_BOOK3E */
838 * We are returning to a context with interrupts soft disabled.
840 * However, we may also about to hard enable, so we need to
841 * make sure that in this case, we also clear PACA_IRQ_HARD_DIS
842 * or that bit can get out of sync and bad things will happen
846 lbz r7,PACAIRQHAPPENED(r13)
849 rlwinm r7,r7,0,~PACA_IRQ_HARD_DIS
850 stb r7,PACAIRQHAPPENED(r13)
852 stb r0,PACASOFTIRQEN(r13);
857 * Something did happen, check if a re-emit is needed
858 * (this also clears paca->irq_happened)
860 restore_check_irq_replay:
861 /* XXX: We could implement a fast path here where we check
862 * for irq_happened being just 0x01, in which case we can
863 * clear it and return. That means that we would potentially
864 * miss a decrementer having wrapped all the way around.
866 * Still, this might be useful for things like hash_page
868 bl .__check_irq_replay
870 beq restore_no_replay
873 * We need to re-emit an interrupt. We do so by re-using our
874 * existing exception frame. We first change the trap value,
875 * but we need to ensure we preserve the low nibble of it
883 * Then find the right handler and call it. Interrupts are
884 * still soft-disabled and we keep them that way.
888 addi r3,r1,STACK_FRAME_OVERHEAD;
891 1: cmpwi cr0,r3,0x900
893 addi r3,r1,STACK_FRAME_OVERHEAD;
896 #ifdef CONFIG_PPC_DOORBELL
898 #ifdef CONFIG_PPC_BOOK3E
905 ALT_FTR_SECTION_END_IFSET(CPU_FTR_HVMODE)
906 #endif /* CONFIG_PPC_BOOK3E */
908 addi r3,r1,STACK_FRAME_OVERHEAD;
909 bl .doorbell_exception
911 #endif /* CONFIG_PPC_DOORBELL */
912 1: b .ret_from_except /* What else to do here ? */
915 addi r3,r1,STACK_FRAME_OVERHEAD
916 bl .unrecoverable_exception
919 #ifdef CONFIG_PPC_RTAS
921 * On CHRP, the Run-Time Abstraction Services (RTAS) have to be
922 * called with the MMU off.
924 * In addition, we need to be in 32b mode, at least for now.
926 * Note: r3 is an input parameter to rtas, so don't trash it...
931 stdu r1,-RTAS_FRAME_SIZE(r1) /* Save SP and create stack space. */
933 /* Because RTAS is running in 32b mode, it clobbers the high order half
934 * of all registers that it saves. We therefore save those registers
935 * RTAS might touch to the stack. (r0, r3-r13 are caller saved)
937 SAVE_GPR(2, r1) /* Save the TOC */
938 SAVE_GPR(13, r1) /* Save paca */
939 SAVE_8GPRS(14, r1) /* Save the non-volatiles */
940 SAVE_10GPRS(22, r1) /* ditto */
953 /* Temporary workaround to clear CR until RTAS can be modified to
960 /* There is no way it is acceptable to get here with interrupts enabled,
961 * check it with the asm equivalent of WARN_ON
963 lbz r0,PACASOFTIRQEN(r13)
965 EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
968 /* Hard-disable interrupts */
974 /* Unfortunately, the stack pointer and the MSR are also clobbered,
975 * so they are saved in the PACA which allows us to restore
976 * our original state after RTAS returns.
979 std r6,PACASAVEDMSR(r13)
981 /* Setup our real return addr */
982 LOAD_REG_ADDR(r4,.rtas_return_loc)
983 clrldi r4,r4,2 /* convert to realmode address */
987 ori r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_RI
991 rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG)
992 ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP|MSR_RI
994 sync /* disable interrupts so SRR0/1 */
995 mtmsrd r0 /* don't get trashed */
997 LOAD_REG_ADDR(r4, rtas)
998 ld r5,RTASENTRY(r4) /* get the rtas->entry value */
999 ld r4,RTASBASE(r4) /* get the rtas->base value */
1004 b . /* prevent speculative execution */
1006 _STATIC(rtas_return_loc)
1007 /* relocation is off at this point */
1009 clrldi r4,r4,2 /* convert to realmode address */
1013 ld r3,(1f-0b)(r3) /* get &.rtas_restore_regs */
1021 ld r1,PACAR1(r4) /* Restore our SP */
1022 ld r4,PACASAVEDMSR(r4) /* Restore our MSR */
1027 b . /* prevent speculative execution */
1030 1: .llong .rtas_restore_regs
1032 _STATIC(rtas_restore_regs)
1033 /* relocation is on at this point */
1034 REST_GPR(2, r1) /* Restore the TOC */
1035 REST_GPR(13, r1) /* Restore paca */
1036 REST_8GPRS(14, r1) /* Restore the non-volatiles */
1037 REST_10GPRS(22, r1) /* ditto */
1052 addi r1,r1,RTAS_FRAME_SIZE /* Unstack our frame */
1053 ld r0,16(r1) /* get return address */
1056 blr /* return to caller */
1058 #endif /* CONFIG_PPC_RTAS */
1063 stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */
1065 /* Because PROM is running in 32b mode, it clobbers the high order half
1066 * of all registers that it saves. We therefore save those registers
1067 * PROM might touch to the stack. (r0, r3-r13 are caller saved)
1078 /* Get the PROM entrypoint */
1081 /* Switch MSR to 32 bits mode
1083 #ifdef CONFIG_PPC_BOOK3E
1084 rlwinm r11,r11,0,1,31
1086 #else /* CONFIG_PPC_BOOK3E */
1089 rldicr r12,r12,MSR_SF_LG,(63-MSR_SF_LG)
1092 rldicr r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG)
1095 #endif /* CONFIG_PPC_BOOK3E */
1098 /* Enter PROM here... */
1101 /* Just make sure that r1 top 32 bits didn't get
1106 /* Restore the MSR (back to 64 bits) */
1111 /* Restore other registers */
1119 addi r1,r1,PROM_FRAME_SIZE
1124 #ifdef CONFIG_FUNCTION_TRACER
1125 #ifdef CONFIG_DYNAMIC_FTRACE
1130 _GLOBAL(ftrace_caller)
1131 /* Taken from output of objdump from lib64/glibc */
1137 subi r3, r3, MCOUNT_INSN_SIZE
1142 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1143 .globl ftrace_graph_call
1146 _GLOBAL(ftrace_graph_stub)
1151 _GLOBAL(ftrace_stub)
1158 /* Taken from output of objdump from lib64/glibc */
1165 subi r3, r3, MCOUNT_INSN_SIZE
1166 LOAD_REG_ADDR(r5,ftrace_trace_function)
1174 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1175 b ftrace_graph_caller
1180 _GLOBAL(ftrace_stub)
1183 #endif /* CONFIG_DYNAMIC_FTRACE */
1185 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1186 _GLOBAL(ftrace_graph_caller)
1187 /* load r4 with local address */
1189 subi r4, r4, MCOUNT_INSN_SIZE
1191 /* get the parent address */
1195 bl .prepare_ftrace_return
1203 _GLOBAL(return_to_handler)
1204 /* need to save return values */
1211 bl .ftrace_return_to_handler
1214 /* return value has real return address */
1222 /* Jump back to real return address */
1225 _GLOBAL(mod_return_to_handler)
1226 /* need to save return values */
1236 * We are in a module using the module's TOC.
1237 * Switch to our TOC to run inside the core kernel.
1241 bl .ftrace_return_to_handler
1244 /* return value has real return address */
1253 /* Jump back to real return address */
1255 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
1256 #endif /* CONFIG_FUNCTION_TRACER */