849 lines
20 KiB
ArmAsm
849 lines
20 KiB
ArmAsm
/*
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* PowerPC version
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* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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* Rewritten by Cort Dougan (cort@cs.nmt.edu) for PReP
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* Copyright (C) 1996 Cort Dougan <cort@cs.nmt.edu>
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* Adapted for Power Macintosh by Paul Mackerras.
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* Low-level exception handlers and MMU support
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* rewritten by Paul Mackerras.
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* Copyright (C) 1996 Paul Mackerras.
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* MPC8xx modifications Copyright (C) 1997 Dan Malek (dmalek@jlc.net).
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*
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* This file contains the system call entry code, context switch
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* code, and exception/interrupt return code for PowerPC.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/errno.h>
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#include <asm/unistd.h>
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#include <asm/processor.h>
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#include <asm/page.h>
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#include <asm/mmu.h>
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#include <asm/thread_info.h>
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#include <asm/ppc_asm.h>
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#include <asm/asm-offsets.h>
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#include <asm/cputable.h>
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#include <asm/firmware.h>
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#include <asm/bug.h>
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/*
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* System calls.
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*/
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.section ".toc","aw"
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.SYS_CALL_TABLE:
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.tc .sys_call_table[TC],.sys_call_table
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/* This value is used to mark exception frames on the stack. */
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exception_marker:
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.tc ID_72656773_68657265[TC],0x7265677368657265
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.section ".text"
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.align 7
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#undef SHOW_SYSCALLS
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.globl system_call_common
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system_call_common:
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andi. r10,r12,MSR_PR
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mr r10,r1
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addi r1,r1,-INT_FRAME_SIZE
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beq- 1f
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ld r1,PACAKSAVE(r13)
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1: std r10,0(r1)
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crclr so
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std r11,_NIP(r1)
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std r12,_MSR(r1)
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std r0,GPR0(r1)
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std r10,GPR1(r1)
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ACCOUNT_CPU_USER_ENTRY(r10, r11)
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std r2,GPR2(r1)
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std r3,GPR3(r1)
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std r4,GPR4(r1)
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std r5,GPR5(r1)
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std r6,GPR6(r1)
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std r7,GPR7(r1)
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std r8,GPR8(r1)
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li r11,0
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std r11,GPR9(r1)
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std r11,GPR10(r1)
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std r11,GPR11(r1)
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std r11,GPR12(r1)
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std r9,GPR13(r1)
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mfcr r9
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mflr r10
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li r11,0xc01
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std r9,_CCR(r1)
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std r10,_LINK(r1)
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std r11,_TRAP(r1)
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mfxer r9
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mfctr r10
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std r9,_XER(r1)
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std r10,_CTR(r1)
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std r3,ORIG_GPR3(r1)
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ld r2,PACATOC(r13)
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addi r9,r1,STACK_FRAME_OVERHEAD
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ld r11,exception_marker@toc(r2)
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std r11,-16(r9) /* "regshere" marker */
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li r10,1
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stb r10,PACASOFTIRQEN(r13)
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stb r10,PACAHARDIRQEN(r13)
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std r10,SOFTE(r1)
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#ifdef CONFIG_PPC_ISERIES
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BEGIN_FW_FTR_SECTION
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/* Hack for handling interrupts when soft-enabling on iSeries */
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cmpdi cr1,r0,0x5555 /* syscall 0x5555 */
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andi. r10,r12,MSR_PR /* from kernel */
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crand 4*cr0+eq,4*cr1+eq,4*cr0+eq
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bne 2f
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b hardware_interrupt_entry
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2:
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END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
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#endif
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mfmsr r11
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ori r11,r11,MSR_EE
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mtmsrd r11,1
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#ifdef SHOW_SYSCALLS
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bl .do_show_syscall
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REST_GPR(0,r1)
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REST_4GPRS(3,r1)
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REST_2GPRS(7,r1)
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addi r9,r1,STACK_FRAME_OVERHEAD
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#endif
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clrrdi r11,r1,THREAD_SHIFT
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ld r10,TI_FLAGS(r11)
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andi. r11,r10,_TIF_SYSCALL_T_OR_A
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bne- syscall_dotrace
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syscall_dotrace_cont:
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cmpldi 0,r0,NR_syscalls
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bge- syscall_enosys
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system_call: /* label this so stack traces look sane */
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/*
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* Need to vector to 32 Bit or default sys_call_table here,
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* based on caller's run-mode / personality.
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*/
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ld r11,.SYS_CALL_TABLE@toc(2)
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andi. r10,r10,_TIF_32BIT
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beq 15f
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addi r11,r11,8 /* use 32-bit syscall entries */
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clrldi r3,r3,32
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clrldi r4,r4,32
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clrldi r5,r5,32
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clrldi r6,r6,32
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clrldi r7,r7,32
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clrldi r8,r8,32
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15:
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slwi r0,r0,4
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ldx r10,r11,r0 /* Fetch system call handler [ptr] */
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mtctr r10
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bctrl /* Call handler */
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syscall_exit:
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std r3,RESULT(r1)
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#ifdef SHOW_SYSCALLS
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bl .do_show_syscall_exit
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ld r3,RESULT(r1)
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#endif
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clrrdi r12,r1,THREAD_SHIFT
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/* disable interrupts so current_thread_info()->flags can't change,
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and so that we don't get interrupted after loading SRR0/1. */
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ld r8,_MSR(r1)
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andi. r10,r8,MSR_RI
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beq- unrecov_restore
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mfmsr r10
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rldicl r10,r10,48,1
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rotldi r10,r10,16
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mtmsrd r10,1
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ld r9,TI_FLAGS(r12)
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li r11,-_LAST_ERRNO
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andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
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bne- syscall_exit_work
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cmpld r3,r11
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ld r5,_CCR(r1)
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bge- syscall_error
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syscall_error_cont:
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ld r7,_NIP(r1)
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stdcx. r0,0,r1 /* to clear the reservation */
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andi. r6,r8,MSR_PR
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ld r4,_LINK(r1)
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/*
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* Clear RI before restoring r13. If we are returning to
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* userspace and we take an exception after restoring r13,
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* we end up corrupting the userspace r13 value.
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*/
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li r12,MSR_RI
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andc r11,r10,r12
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mtmsrd r11,1 /* clear MSR.RI */
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beq- 1f
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ACCOUNT_CPU_USER_EXIT(r11, r12)
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ld r13,GPR13(r1) /* only restore r13 if returning to usermode */
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1: ld r2,GPR2(r1)
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ld r1,GPR1(r1)
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mtlr r4
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mtcr r5
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mtspr SPRN_SRR0,r7
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mtspr SPRN_SRR1,r8
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rfid
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b . /* prevent speculative execution */
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syscall_error:
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oris r5,r5,0x1000 /* Set SO bit in CR */
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neg r3,r3
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std r5,_CCR(r1)
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b syscall_error_cont
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/* Traced system call support */
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syscall_dotrace:
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bl .save_nvgprs
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addi r3,r1,STACK_FRAME_OVERHEAD
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bl .do_syscall_trace_enter
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ld r0,GPR0(r1) /* Restore original registers */
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ld r3,GPR3(r1)
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ld r4,GPR4(r1)
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ld r5,GPR5(r1)
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ld r6,GPR6(r1)
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ld r7,GPR7(r1)
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ld r8,GPR8(r1)
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addi r9,r1,STACK_FRAME_OVERHEAD
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clrrdi r10,r1,THREAD_SHIFT
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ld r10,TI_FLAGS(r10)
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b syscall_dotrace_cont
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syscall_enosys:
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li r3,-ENOSYS
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b syscall_exit
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syscall_exit_work:
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/* If TIF_RESTOREALL is set, don't scribble on either r3 or ccr.
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If TIF_NOERROR is set, just save r3 as it is. */
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andi. r0,r9,_TIF_RESTOREALL
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beq+ 0f
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REST_NVGPRS(r1)
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b 2f
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0: cmpld r3,r11 /* r10 is -LAST_ERRNO */
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blt+ 1f
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andi. r0,r9,_TIF_NOERROR
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bne- 1f
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ld r5,_CCR(r1)
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neg r3,r3
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oris r5,r5,0x1000 /* Set SO bit in CR */
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std r5,_CCR(r1)
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1: std r3,GPR3(r1)
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2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
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beq 4f
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/* Clear per-syscall TIF flags if any are set. */
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li r11,_TIF_PERSYSCALL_MASK
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addi r12,r12,TI_FLAGS
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3: ldarx r10,0,r12
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andc r10,r10,r11
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stdcx. r10,0,r12
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bne- 3b
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subi r12,r12,TI_FLAGS
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4: /* Anything else left to do? */
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andi. r0,r9,(_TIF_SYSCALL_T_OR_A|_TIF_SINGLESTEP)
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beq .ret_from_except_lite
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/* Re-enable interrupts */
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mfmsr r10
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ori r10,r10,MSR_EE
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mtmsrd r10,1
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bl .save_nvgprs
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addi r3,r1,STACK_FRAME_OVERHEAD
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bl .do_syscall_trace_leave
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b .ret_from_except
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/* Save non-volatile GPRs, if not already saved. */
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_GLOBAL(save_nvgprs)
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ld r11,_TRAP(r1)
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andi. r0,r11,1
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beqlr-
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SAVE_NVGPRS(r1)
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clrrdi r0,r11,1
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std r0,_TRAP(r1)
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blr
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/*
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* The sigsuspend and rt_sigsuspend system calls can call do_signal
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* and thus put the process into the stopped state where we might
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* want to examine its user state with ptrace. Therefore we need
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* to save all the nonvolatile registers (r14 - r31) before calling
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* the C code. Similarly, fork, vfork and clone need the full
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* register state on the stack so that it can be copied to the child.
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*/
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_GLOBAL(ppc_fork)
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bl .save_nvgprs
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bl .sys_fork
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b syscall_exit
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_GLOBAL(ppc_vfork)
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bl .save_nvgprs
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bl .sys_vfork
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b syscall_exit
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_GLOBAL(ppc_clone)
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bl .save_nvgprs
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bl .sys_clone
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b syscall_exit
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_GLOBAL(ppc32_swapcontext)
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bl .save_nvgprs
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bl .compat_sys_swapcontext
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b syscall_exit
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_GLOBAL(ppc64_swapcontext)
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bl .save_nvgprs
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bl .sys_swapcontext
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b syscall_exit
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_GLOBAL(ret_from_fork)
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bl .schedule_tail
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REST_NVGPRS(r1)
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li r3,0
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b syscall_exit
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/*
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* This routine switches between two different tasks. The process
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* state of one is saved on its kernel stack. Then the state
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* of the other is restored from its kernel stack. The memory
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* management hardware is updated to the second process's state.
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* Finally, we can return to the second process, via ret_from_except.
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* On entry, r3 points to the THREAD for the current task, r4
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* points to the THREAD for the new task.
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*
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* Note: there are two ways to get to the "going out" portion
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* of this code; either by coming in via the entry (_switch)
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* or via "fork" which must set up an environment equivalent
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* to the "_switch" path. If you change this you'll have to change
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* the fork code also.
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*
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* The code which creates the new task context is in 'copy_thread'
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* in arch/powerpc/kernel/process.c
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*/
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.align 7
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_GLOBAL(_switch)
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mflr r0
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std r0,16(r1)
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stdu r1,-SWITCH_FRAME_SIZE(r1)
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/* r3-r13 are caller saved -- Cort */
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SAVE_8GPRS(14, r1)
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SAVE_10GPRS(22, r1)
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mflr r20 /* Return to switch caller */
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mfmsr r22
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li r0, MSR_FP
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#ifdef CONFIG_ALTIVEC
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BEGIN_FTR_SECTION
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oris r0,r0,MSR_VEC@h /* Disable altivec */
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mfspr r24,SPRN_VRSAVE /* save vrsave register value */
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std r24,THREAD_VRSAVE(r3)
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END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
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#endif /* CONFIG_ALTIVEC */
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and. r0,r0,r22
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beq+ 1f
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andc r22,r22,r0
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mtmsrd r22
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isync
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1: std r20,_NIP(r1)
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mfcr r23
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std r23,_CCR(r1)
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std r1,KSP(r3) /* Set old stack pointer */
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#ifdef CONFIG_SMP
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/* We need a sync somewhere here to make sure that if the
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* previous task gets rescheduled on another CPU, it sees all
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* stores it has performed on this one.
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*/
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sync
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#endif /* CONFIG_SMP */
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addi r6,r4,-THREAD /* Convert THREAD to 'current' */
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std r6,PACACURRENT(r13) /* Set new 'current' */
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ld r8,KSP(r4) /* new stack pointer */
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BEGIN_FTR_SECTION
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b 2f
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END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
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BEGIN_FTR_SECTION
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clrrdi r6,r8,28 /* get its ESID */
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clrrdi r9,r1,28 /* get current sp ESID */
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END_FTR_SECTION_IFCLR(CPU_FTR_1T_SEGMENT)
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BEGIN_FTR_SECTION
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clrrdi r6,r8,40 /* get its 1T ESID */
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clrrdi r9,r1,40 /* get current sp 1T ESID */
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END_FTR_SECTION_IFSET(CPU_FTR_1T_SEGMENT)
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clrldi. r0,r6,2 /* is new ESID c00000000? */
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cmpd cr1,r6,r9 /* or is new ESID the same as current ESID? */
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cror eq,4*cr1+eq,eq
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beq 2f /* if yes, don't slbie it */
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/* Bolt in the new stack SLB entry */
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ld r7,KSP_VSID(r4) /* Get new stack's VSID */
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oris r0,r6,(SLB_ESID_V)@h
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ori r0,r0,(SLB_NUM_BOLTED-1)@l
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BEGIN_FTR_SECTION
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li r9,MMU_SEGSIZE_1T /* insert B field */
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oris r6,r6,(MMU_SEGSIZE_1T << SLBIE_SSIZE_SHIFT)@h
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rldimi r7,r9,SLB_VSID_SSIZE_SHIFT,0
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END_FTR_SECTION_IFSET(CPU_FTR_1T_SEGMENT)
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/* Update the last bolted SLB. No write barriers are needed
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* here, provided we only update the current CPU's SLB shadow
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* buffer.
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*/
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ld r9,PACA_SLBSHADOWPTR(r13)
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li r12,0
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std r12,SLBSHADOW_STACKESID(r9) /* Clear ESID */
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std r7,SLBSHADOW_STACKVSID(r9) /* Save VSID */
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std r0,SLBSHADOW_STACKESID(r9) /* Save ESID */
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/* No need to check for CPU_FTR_NO_SLBIE_B here, since when
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* we have 1TB segments, the only CPUs known to have the errata
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* only support less than 1TB of system memory and we'll never
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* actually hit this code path.
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*/
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slbie r6
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slbie r6 /* Workaround POWER5 < DD2.1 issue */
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slbmte r7,r0
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isync
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2:
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clrrdi r7,r8,THREAD_SHIFT /* base of new stack */
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/* Note: this uses SWITCH_FRAME_SIZE rather than INT_FRAME_SIZE
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because we don't need to leave the 288-byte ABI gap at the
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top of the kernel stack. */
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addi r7,r7,THREAD_SIZE-SWITCH_FRAME_SIZE
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mr r1,r8 /* start using new stack pointer */
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std r7,PACAKSAVE(r13)
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ld r6,_CCR(r1)
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mtcrf 0xFF,r6
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#ifdef CONFIG_ALTIVEC
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BEGIN_FTR_SECTION
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ld r0,THREAD_VRSAVE(r4)
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mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */
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END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
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#endif /* CONFIG_ALTIVEC */
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/* r3-r13 are destroyed -- Cort */
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REST_8GPRS(14, r1)
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REST_10GPRS(22, r1)
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|
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/* convert old thread to its task_struct for return value */
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addi r3,r3,-THREAD
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ld r7,_NIP(r1) /* Return to _switch caller in new task */
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mtlr r7
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addi r1,r1,SWITCH_FRAME_SIZE
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blr
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.align 7
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_GLOBAL(ret_from_except)
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ld r11,_TRAP(r1)
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andi. r0,r11,1
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bne .ret_from_except_lite
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REST_NVGPRS(r1)
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_GLOBAL(ret_from_except_lite)
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/*
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* Disable interrupts so that current_thread_info()->flags
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* can't change between when we test it and when we return
|
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* from the interrupt.
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*/
|
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mfmsr r10 /* Get current interrupt state */
|
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rldicl r9,r10,48,1 /* clear MSR_EE */
|
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rotldi r9,r9,16
|
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mtmsrd r9,1 /* Update machine state */
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|
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#ifdef CONFIG_PREEMPT
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clrrdi r9,r1,THREAD_SHIFT /* current_thread_info() */
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li r0,_TIF_NEED_RESCHED /* bits to check */
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ld r3,_MSR(r1)
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ld r4,TI_FLAGS(r9)
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/* Move MSR_PR bit in r3 to _TIF_SIGPENDING position in r0 */
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rlwimi r0,r3,32+TIF_SIGPENDING-MSR_PR_LG,_TIF_SIGPENDING
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and. r0,r4,r0 /* check NEED_RESCHED and maybe SIGPENDING */
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bne do_work
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#else /* !CONFIG_PREEMPT */
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ld r3,_MSR(r1) /* Returning to user mode? */
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andi. r3,r3,MSR_PR
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beq restore /* if not, just restore regs and return */
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/* Check current_thread_info()->flags */
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clrrdi r9,r1,THREAD_SHIFT
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ld r4,TI_FLAGS(r9)
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andi. r0,r4,_TIF_USER_WORK_MASK
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bne do_work
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#endif
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restore:
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ld r5,SOFTE(r1)
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#ifdef CONFIG_PPC_ISERIES
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BEGIN_FW_FTR_SECTION
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cmpdi 0,r5,0
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beq 4f
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/* Check for pending interrupts (iSeries) */
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ld r3,PACALPPACAPTR(r13)
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ld r3,LPPACAANYINT(r3)
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cmpdi r3,0
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beq+ 4f /* skip do_IRQ if no interrupts */
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li r3,0
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stb r3,PACASOFTIRQEN(r13) /* ensure we are soft-disabled */
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ori r10,r10,MSR_EE
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mtmsrd r10 /* hard-enable again */
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addi r3,r1,STACK_FRAME_OVERHEAD
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bl .do_IRQ
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b .ret_from_except_lite /* loop back and handle more */
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4:
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END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
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#endif
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stb r5,PACASOFTIRQEN(r13)
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/* extract EE bit and use it to restore paca->hard_enabled */
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ld r3,_MSR(r1)
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rldicl r4,r3,49,63 /* r0 = (r3 >> 15) & 1 */
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stb r4,PACAHARDIRQEN(r13)
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ld r4,_CTR(r1)
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ld r0,_LINK(r1)
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mtctr r4
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mtlr r0
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ld r4,_XER(r1)
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mtspr SPRN_XER,r4
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REST_8GPRS(5, r1)
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andi. r0,r3,MSR_RI
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beq- unrecov_restore
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stdcx. r0,0,r1 /* to clear the reservation */
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/*
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* Clear RI before restoring r13. If we are returning to
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* userspace and we take an exception after restoring r13,
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* we end up corrupting the userspace r13 value.
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*/
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mfmsr r4
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andc r4,r4,r0 /* r0 contains MSR_RI here */
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mtmsrd r4,1
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/*
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* r13 is our per cpu area, only restore it if we are returning to
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* userspace
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*/
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andi. r0,r3,MSR_PR
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beq 1f
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ACCOUNT_CPU_USER_EXIT(r2, r4)
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REST_GPR(13, r1)
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1:
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mtspr SPRN_SRR1,r3
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ld r2,_CCR(r1)
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mtcrf 0xFF,r2
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ld r2,_NIP(r1)
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mtspr SPRN_SRR0,r2
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ld r0,GPR0(r1)
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ld r2,GPR2(r1)
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ld r3,GPR3(r1)
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ld r4,GPR4(r1)
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ld r1,GPR1(r1)
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rfid
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b . /* prevent speculative execution */
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do_work:
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#ifdef CONFIG_PREEMPT
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andi. r0,r3,MSR_PR /* Returning to user mode? */
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bne user_work
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/* Check that preempt_count() == 0 and interrupts are enabled */
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lwz r8,TI_PREEMPT(r9)
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cmpwi cr1,r8,0
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ld r0,SOFTE(r1)
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cmpdi r0,0
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crandc eq,cr1*4+eq,eq
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bne restore
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/* here we are preempting the current task */
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1:
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li r0,1
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stb r0,PACASOFTIRQEN(r13)
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stb r0,PACAHARDIRQEN(r13)
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ori r10,r10,MSR_EE
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mtmsrd r10,1 /* reenable interrupts */
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bl .preempt_schedule
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mfmsr r10
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clrrdi r9,r1,THREAD_SHIFT
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rldicl r10,r10,48,1 /* disable interrupts again */
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rotldi r10,r10,16
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mtmsrd r10,1
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ld r4,TI_FLAGS(r9)
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andi. r0,r4,_TIF_NEED_RESCHED
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bne 1b
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b restore
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user_work:
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#endif
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/* Enable interrupts */
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ori r10,r10,MSR_EE
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mtmsrd r10,1
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andi. r0,r4,_TIF_NEED_RESCHED
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beq 1f
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bl .schedule
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b .ret_from_except_lite
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1: bl .save_nvgprs
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li r3,0
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addi r4,r1,STACK_FRAME_OVERHEAD
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bl .do_signal
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b .ret_from_except
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unrecov_restore:
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addi r3,r1,STACK_FRAME_OVERHEAD
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bl .unrecoverable_exception
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b unrecov_restore
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#ifdef CONFIG_PPC_RTAS
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/*
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* On CHRP, the Run-Time Abstraction Services (RTAS) have to be
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* called with the MMU off.
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*
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* In addition, we need to be in 32b mode, at least for now.
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*
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* Note: r3 is an input parameter to rtas, so don't trash it...
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*/
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_GLOBAL(enter_rtas)
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mflr r0
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std r0,16(r1)
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stdu r1,-RTAS_FRAME_SIZE(r1) /* Save SP and create stack space. */
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/* Because RTAS is running in 32b mode, it clobbers the high order half
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* of all registers that it saves. We therefore save those registers
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* RTAS might touch to the stack. (r0, r3-r13 are caller saved)
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*/
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SAVE_GPR(2, r1) /* Save the TOC */
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SAVE_GPR(13, r1) /* Save paca */
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SAVE_8GPRS(14, r1) /* Save the non-volatiles */
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SAVE_10GPRS(22, r1) /* ditto */
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mfcr r4
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std r4,_CCR(r1)
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mfctr r5
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std r5,_CTR(r1)
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mfspr r6,SPRN_XER
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std r6,_XER(r1)
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mfdar r7
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std r7,_DAR(r1)
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mfdsisr r8
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std r8,_DSISR(r1)
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mfsrr0 r9
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std r9,_SRR0(r1)
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mfsrr1 r10
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std r10,_SRR1(r1)
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/* Temporary workaround to clear CR until RTAS can be modified to
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* ignore all bits.
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*/
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li r0,0
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mtcr r0
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#ifdef CONFIG_BUG
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/* There is no way it is acceptable to get here with interrupts enabled,
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* check it with the asm equivalent of WARN_ON
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*/
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lbz r0,PACASOFTIRQEN(r13)
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1: tdnei r0,0
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EMIT_BUG_ENTRY 1b,__FILE__,__LINE__,BUGFLAG_WARNING
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#endif
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/* Hard-disable interrupts */
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mfmsr r6
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rldicl r7,r6,48,1
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rotldi r7,r7,16
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mtmsrd r7,1
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/* Unfortunately, the stack pointer and the MSR are also clobbered,
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* so they are saved in the PACA which allows us to restore
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* our original state after RTAS returns.
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*/
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std r1,PACAR1(r13)
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std r6,PACASAVEDMSR(r13)
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/* Setup our real return addr */
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LOAD_REG_ADDR(r4,.rtas_return_loc)
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clrldi r4,r4,2 /* convert to realmode address */
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mtlr r4
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li r0,0
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ori r0,r0,MSR_EE|MSR_SE|MSR_BE|MSR_RI
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andc r0,r6,r0
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li r9,1
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rldicr r9,r9,MSR_SF_LG,(63-MSR_SF_LG)
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ori r9,r9,MSR_IR|MSR_DR|MSR_FE0|MSR_FE1|MSR_FP
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andc r6,r0,r9
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ori r6,r6,MSR_RI
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sync /* disable interrupts so SRR0/1 */
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mtmsrd r0 /* don't get trashed */
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LOAD_REG_ADDR(r4, rtas)
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ld r5,RTASENTRY(r4) /* get the rtas->entry value */
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ld r4,RTASBASE(r4) /* get the rtas->base value */
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mtspr SPRN_SRR0,r5
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mtspr SPRN_SRR1,r6
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rfid
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b . /* prevent speculative execution */
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_STATIC(rtas_return_loc)
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/* relocation is off at this point */
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mfspr r4,SPRN_SPRG3 /* Get PACA */
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clrldi r4,r4,2 /* convert to realmode address */
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mfmsr r6
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li r0,MSR_RI
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andc r6,r6,r0
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sync
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mtmsrd r6
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ld r1,PACAR1(r4) /* Restore our SP */
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LOAD_REG_IMMEDIATE(r3,.rtas_restore_regs)
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ld r4,PACASAVEDMSR(r4) /* Restore our MSR */
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mtspr SPRN_SRR0,r3
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mtspr SPRN_SRR1,r4
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rfid
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b . /* prevent speculative execution */
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_STATIC(rtas_restore_regs)
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/* relocation is on at this point */
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REST_GPR(2, r1) /* Restore the TOC */
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REST_GPR(13, r1) /* Restore paca */
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REST_8GPRS(14, r1) /* Restore the non-volatiles */
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REST_10GPRS(22, r1) /* ditto */
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mfspr r13,SPRN_SPRG3
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ld r4,_CCR(r1)
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mtcr r4
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ld r5,_CTR(r1)
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mtctr r5
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ld r6,_XER(r1)
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mtspr SPRN_XER,r6
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ld r7,_DAR(r1)
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mtdar r7
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ld r8,_DSISR(r1)
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mtdsisr r8
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ld r9,_SRR0(r1)
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mtsrr0 r9
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ld r10,_SRR1(r1)
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mtsrr1 r10
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addi r1,r1,RTAS_FRAME_SIZE /* Unstack our frame */
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ld r0,16(r1) /* get return address */
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mtlr r0
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blr /* return to caller */
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|
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#endif /* CONFIG_PPC_RTAS */
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|
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_GLOBAL(enter_prom)
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mflr r0
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std r0,16(r1)
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stdu r1,-PROM_FRAME_SIZE(r1) /* Save SP and create stack space */
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/* Because PROM is running in 32b mode, it clobbers the high order half
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* of all registers that it saves. We therefore save those registers
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* PROM might touch to the stack. (r0, r3-r13 are caller saved)
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*/
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SAVE_8GPRS(2, r1)
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SAVE_GPR(13, r1)
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SAVE_8GPRS(14, r1)
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SAVE_10GPRS(22, r1)
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mfcr r4
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std r4,_CCR(r1)
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mfctr r5
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std r5,_CTR(r1)
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mfspr r6,SPRN_XER
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std r6,_XER(r1)
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mfdar r7
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std r7,_DAR(r1)
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mfdsisr r8
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std r8,_DSISR(r1)
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mfsrr0 r9
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std r9,_SRR0(r1)
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mfsrr1 r10
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std r10,_SRR1(r1)
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mfmsr r11
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std r11,_MSR(r1)
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|
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/* Get the PROM entrypoint */
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ld r0,GPR4(r1)
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mtlr r0
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|
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/* Switch MSR to 32 bits mode
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*/
|
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mfmsr r11
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li r12,1
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rldicr r12,r12,MSR_SF_LG,(63-MSR_SF_LG)
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andc r11,r11,r12
|
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li r12,1
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rldicr r12,r12,MSR_ISF_LG,(63-MSR_ISF_LG)
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andc r11,r11,r12
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mtmsrd r11
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isync
|
|
|
|
/* Restore arguments & enter PROM here... */
|
|
ld r3,GPR3(r1)
|
|
blrl
|
|
|
|
/* Just make sure that r1 top 32 bits didn't get
|
|
* corrupt by OF
|
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*/
|
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rldicl r1,r1,0,32
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|
|
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/* Restore the MSR (back to 64 bits) */
|
|
ld r0,_MSR(r1)
|
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mtmsrd r0
|
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isync
|
|
|
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/* Restore other registers */
|
|
REST_GPR(2, r1)
|
|
REST_GPR(13, r1)
|
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REST_8GPRS(14, r1)
|
|
REST_10GPRS(22, r1)
|
|
ld r4,_CCR(r1)
|
|
mtcr r4
|
|
ld r5,_CTR(r1)
|
|
mtctr r5
|
|
ld r6,_XER(r1)
|
|
mtspr SPRN_XER,r6
|
|
ld r7,_DAR(r1)
|
|
mtdar r7
|
|
ld r8,_DSISR(r1)
|
|
mtdsisr r8
|
|
ld r9,_SRR0(r1)
|
|
mtsrr0 r9
|
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ld r10,_SRR1(r1)
|
|
mtsrr1 r10
|
|
|
|
addi r1,r1,PROM_FRAME_SIZE
|
|
ld r0,16(r1)
|
|
mtlr r0
|
|
blr
|