/* SPDX-License-Identifier: GPL-2.0-or-later */
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/*
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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@fsmlabs.com) for PReP
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* Copyright (C) 1996 Cort Dougan <cort@fsmlabs.com>
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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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#include <linux/errno.h>
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#include <linux/err.h>
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#include <linux/sys.h>
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#include <linux/threads.h>
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#include <asm/reg.h>
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#include <asm/page.h>
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#include <asm/mmu.h>
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#include <asm/cputable.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/unistd.h>
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#include <asm/ptrace.h>
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#include <asm/export.h>
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#include <asm/feature-fixups.h>
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#include <asm/barrier.h>
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#include <asm/kup.h>
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#include <asm/bug.h>
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#include "head_32.h"
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/*
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* powerpc relies on return from interrupt/syscall being context synchronising
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* (which rfi is) to support ARCH_HAS_MEMBARRIER_SYNC_CORE without additional
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* synchronisation instructions.
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*/
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/*
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* Align to 4k in order to ensure that all functions modyfing srr0/srr1
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* fit into one page in order to not encounter a TLB miss between the
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* modification of srr0/srr1 and the associated rfi.
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*/
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.align 12
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#ifdef CONFIG_BOOKE
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.globl mcheck_transfer_to_handler
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mcheck_transfer_to_handler:
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mfspr r0,SPRN_DSRR0
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stw r0,_DSRR0(r11)
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mfspr r0,SPRN_DSRR1
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stw r0,_DSRR1(r11)
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/* fall through */
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_ASM_NOKPROBE_SYMBOL(mcheck_transfer_to_handler)
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.globl debug_transfer_to_handler
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debug_transfer_to_handler:
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mfspr r0,SPRN_CSRR0
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stw r0,_CSRR0(r11)
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mfspr r0,SPRN_CSRR1
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stw r0,_CSRR1(r11)
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/* fall through */
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_ASM_NOKPROBE_SYMBOL(debug_transfer_to_handler)
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.globl crit_transfer_to_handler
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crit_transfer_to_handler:
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#ifdef CONFIG_PPC_BOOK3E_MMU
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mfspr r0,SPRN_MAS0
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stw r0,MAS0(r11)
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mfspr r0,SPRN_MAS1
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stw r0,MAS1(r11)
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mfspr r0,SPRN_MAS2
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stw r0,MAS2(r11)
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mfspr r0,SPRN_MAS3
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stw r0,MAS3(r11)
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mfspr r0,SPRN_MAS6
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stw r0,MAS6(r11)
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#ifdef CONFIG_PHYS_64BIT
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mfspr r0,SPRN_MAS7
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stw r0,MAS7(r11)
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#endif /* CONFIG_PHYS_64BIT */
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#endif /* CONFIG_PPC_BOOK3E_MMU */
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#ifdef CONFIG_44x
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mfspr r0,SPRN_MMUCR
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stw r0,MMUCR(r11)
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#endif
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mfspr r0,SPRN_SRR0
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stw r0,_SRR0(r11)
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mfspr r0,SPRN_SRR1
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stw r0,_SRR1(r11)
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/* set the stack limit to the current stack */
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mfspr r8,SPRN_SPRG_THREAD
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lwz r0,KSP_LIMIT(r8)
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stw r0,SAVED_KSP_LIMIT(r11)
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rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
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stw r0,KSP_LIMIT(r8)
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/* fall through */
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_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
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#endif
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#ifdef CONFIG_40x
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.globl crit_transfer_to_handler
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crit_transfer_to_handler:
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lwz r0,crit_r10@l(0)
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stw r0,GPR10(r11)
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lwz r0,crit_r11@l(0)
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stw r0,GPR11(r11)
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mfspr r0,SPRN_SRR0
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stw r0,crit_srr0@l(0)
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mfspr r0,SPRN_SRR1
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stw r0,crit_srr1@l(0)
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/* set the stack limit to the current stack */
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mfspr r8,SPRN_SPRG_THREAD
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lwz r0,KSP_LIMIT(r8)
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stw r0,saved_ksp_limit@l(0)
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rlwinm r0,r1,0,0,(31 - THREAD_SHIFT)
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stw r0,KSP_LIMIT(r8)
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/* fall through */
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_ASM_NOKPROBE_SYMBOL(crit_transfer_to_handler)
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#endif
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/*
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* This code finishes saving the registers to the exception frame
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* and jumps to the appropriate handler for the exception, turning
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* on address translation.
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* Note that we rely on the caller having set cr0.eq iff the exception
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* occurred in kernel mode (i.e. MSR:PR = 0).
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*/
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.globl transfer_to_handler_full
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transfer_to_handler_full:
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SAVE_NVGPRS(r11)
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_ASM_NOKPROBE_SYMBOL(transfer_to_handler_full)
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/* fall through */
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.globl transfer_to_handler
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transfer_to_handler:
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stw r2,GPR2(r11)
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stw r12,_NIP(r11)
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stw r9,_MSR(r11)
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andi. r2,r9,MSR_PR
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mfctr r12
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mfspr r2,SPRN_XER
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stw r12,_CTR(r11)
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stw r2,_XER(r11)
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mfspr r12,SPRN_SPRG_THREAD
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tovirt_vmstack r12, r12
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beq 2f /* if from user, fix up THREAD.regs */
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addi r2, r12, -THREAD
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addi r11,r1,STACK_FRAME_OVERHEAD
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stw r11,PT_REGS(r12)
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#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
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/* Check to see if the dbcr0 register is set up to debug. Use the
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internal debug mode bit to do this. */
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lwz r12,THREAD_DBCR0(r12)
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andis. r12,r12,DBCR0_IDM@h
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#endif
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ACCOUNT_CPU_USER_ENTRY(r2, r11, r12)
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#ifdef CONFIG_PPC_BOOK3S_32
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kuep_lock r11, r12
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#endif
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#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
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beq+ 3f
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/* From user and task is ptraced - load up global dbcr0 */
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li r12,-1 /* clear all pending debug events */
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mtspr SPRN_DBSR,r12
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lis r11,global_dbcr0@ha
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tophys(r11,r11)
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addi r11,r11,global_dbcr0@l
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#ifdef CONFIG_SMP
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lwz r9,TASK_CPU(r2)
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slwi r9,r9,3
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add r11,r11,r9
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#endif
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lwz r12,0(r11)
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mtspr SPRN_DBCR0,r12
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lwz r12,4(r11)
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addi r12,r12,-1
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stw r12,4(r11)
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#endif
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b 3f
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2: /* if from kernel, check interrupted DOZE/NAP mode and
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* check for stack overflow
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*/
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kuap_save_and_lock r11, r12, r9, r2, r6
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addi r2, r12, -THREAD
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#ifndef CONFIG_VMAP_STACK
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lwz r9,KSP_LIMIT(r12)
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cmplw r1,r9 /* if r1 <= ksp_limit */
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ble- stack_ovf /* then the kernel stack overflowed */
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#endif
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5:
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#if defined(CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
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lwz r12,TI_LOCAL_FLAGS(r2)
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mtcrf 0x01,r12
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bt- 31-TLF_NAPPING,4f
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bt- 31-TLF_SLEEPING,7f
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#endif /* CONFIG_PPC_BOOK3S_32 || CONFIG_E500 */
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.globl transfer_to_handler_cont
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transfer_to_handler_cont:
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3:
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mflr r9
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tovirt_novmstack r2, r2 /* set r2 to current */
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tovirt_vmstack r9, r9
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lwz r11,0(r9) /* virtual address of handler */
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lwz r9,4(r9) /* where to go when done */
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#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
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mtspr SPRN_NRI, r0
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#endif
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#ifdef CONFIG_TRACE_IRQFLAGS
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/*
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* When tracing IRQ state (lockdep) we enable the MMU before we call
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* the IRQ tracing functions as they might access vmalloc space or
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* perform IOs for console output.
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*
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* To speed up the syscall path where interrupts stay on, let's check
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* first if we are changing the MSR value at all.
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*/
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tophys_novmstack r12, r1
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lwz r12,_MSR(r12)
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andi. r12,r12,MSR_EE
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bne 1f
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/* MSR isn't changing, just transition directly */
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#endif
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mtspr SPRN_SRR0,r11
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mtspr SPRN_SRR1,r10
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mtlr r9
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RFI /* jump to handler, enable MMU */
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#if defined (CONFIG_PPC_BOOK3S_32) || defined(CONFIG_E500)
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4: rlwinm r12,r12,0,~_TLF_NAPPING
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stw r12,TI_LOCAL_FLAGS(r2)
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b power_save_ppc32_restore
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7: rlwinm r12,r12,0,~_TLF_SLEEPING
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stw r12,TI_LOCAL_FLAGS(r2)
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lwz r9,_MSR(r11) /* if sleeping, clear MSR.EE */
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rlwinm r9,r9,0,~MSR_EE
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lwz r12,_LINK(r11) /* and return to address in LR */
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kuap_restore r11, r2, r3, r4, r5
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lwz r2, GPR2(r11)
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b fast_exception_return
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#endif
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_ASM_NOKPROBE_SYMBOL(transfer_to_handler)
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_ASM_NOKPROBE_SYMBOL(transfer_to_handler_cont)
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#ifdef CONFIG_TRACE_IRQFLAGS
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1: /* MSR is changing, re-enable MMU so we can notify lockdep. We need to
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* keep interrupts disabled at this point otherwise we might risk
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* taking an interrupt before we tell lockdep they are enabled.
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*/
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lis r12,reenable_mmu@h
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ori r12,r12,reenable_mmu@l
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LOAD_REG_IMMEDIATE(r0, MSR_KERNEL)
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mtspr SPRN_SRR0,r12
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mtspr SPRN_SRR1,r0
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RFI
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reenable_mmu:
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/*
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* We save a bunch of GPRs,
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* r3 can be different from GPR3(r1) at this point, r9 and r11
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* contains the old MSR and handler address respectively,
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* r4 & r5 can contain page fault arguments that need to be passed
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* along as well. r0, r6-r8, r12, CCR, CTR, XER etc... are left
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* clobbered as they aren't useful past this point.
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*/
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stwu r1,-32(r1)
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stw r9,8(r1)
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stw r11,12(r1)
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stw r3,16(r1)
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stw r4,20(r1)
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stw r5,24(r1)
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/* If we are disabling interrupts (normal case), simply log it with
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* lockdep
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*/
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1: bl trace_hardirqs_off
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lwz r5,24(r1)
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lwz r4,20(r1)
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lwz r3,16(r1)
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lwz r11,12(r1)
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lwz r9,8(r1)
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addi r1,r1,32
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mtctr r11
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mtlr r9
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bctr /* jump to handler */
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#endif /* CONFIG_TRACE_IRQFLAGS */
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#ifndef CONFIG_VMAP_STACK
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/*
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* On kernel stack overflow, load up an initial stack pointer
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* and call StackOverflow(regs), which should not return.
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*/
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stack_ovf:
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/* sometimes we use a statically-allocated stack, which is OK. */
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lis r12,_end@h
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ori r12,r12,_end@l
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cmplw r1,r12
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ble 5b /* r1 <= &_end is OK */
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SAVE_NVGPRS(r11)
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addi r3,r1,STACK_FRAME_OVERHEAD
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lis r1,init_thread_union@ha
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addi r1,r1,init_thread_union@l
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addi r1,r1,THREAD_SIZE-STACK_FRAME_OVERHEAD
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lis r9,StackOverflow@ha
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addi r9,r9,StackOverflow@l
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LOAD_REG_IMMEDIATE(r10,MSR_KERNEL)
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#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
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mtspr SPRN_NRI, r0
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#endif
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mtspr SPRN_SRR0,r9
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mtspr SPRN_SRR1,r10
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RFI
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_ASM_NOKPROBE_SYMBOL(stack_ovf)
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#endif
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#ifdef CONFIG_TRACE_IRQFLAGS
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trace_syscall_entry_irq_off:
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/*
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* Syscall shouldn't happen while interrupts are disabled,
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* so let's do a warning here.
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*/
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0: trap
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EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
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bl trace_hardirqs_on
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/* Now enable for real */
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LOAD_REG_IMMEDIATE(r10, MSR_KERNEL | MSR_EE)
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mtmsr r10
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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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b DoSyscall
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#endif /* CONFIG_TRACE_IRQFLAGS */
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.globl transfer_to_syscall
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transfer_to_syscall:
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#ifdef CONFIG_PPC_BOOK3S_32
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kuep_lock r11, r12
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#endif
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#ifdef CONFIG_TRACE_IRQFLAGS
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andi. r12,r9,MSR_EE
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beq- trace_syscall_entry_irq_off
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#endif /* CONFIG_TRACE_IRQFLAGS */
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/*
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* Handle a system call.
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*/
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.stabs "arch/powerpc/kernel/",N_SO,0,0,0f
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.stabs "entry_32.S",N_SO,0,0,0f
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0:
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_GLOBAL(DoSyscall)
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stw r3,ORIG_GPR3(r1)
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li r12,0
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stw r12,RESULT(r1)
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#ifdef CONFIG_TRACE_IRQFLAGS
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/* Make sure interrupts are enabled */
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mfmsr r11
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andi. r12,r11,MSR_EE
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/* We came in with interrupts disabled, we WARN and mark them enabled
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* for lockdep now */
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0: tweqi r12, 0
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EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
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#endif /* CONFIG_TRACE_IRQFLAGS */
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lwz r11,TI_FLAGS(r2)
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andi. r11,r11,_TIF_SYSCALL_DOTRACE
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bne- syscall_dotrace
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syscall_dotrace_cont:
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cmplwi 0,r0,NR_syscalls
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lis r10,sys_call_table@h
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ori r10,r10,sys_call_table@l
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slwi r0,r0,2
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bge- 66f
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barrier_nospec_asm
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/*
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* Prevent the load of the handler below (based on the user-passed
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* system call number) being speculatively executed until the test
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* against NR_syscalls and branch to .66f above has
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* committed.
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*/
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lwzx r10,r10,r0 /* Fetch system call handler [ptr] */
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mtlr r10
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addi r9,r1,STACK_FRAME_OVERHEAD
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PPC440EP_ERR42
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blrl /* Call handler */
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.globl ret_from_syscall
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ret_from_syscall:
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#ifdef CONFIG_DEBUG_RSEQ
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/* Check whether the syscall is issued inside a restartable sequence */
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stw r3,GPR3(r1)
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addi r3,r1,STACK_FRAME_OVERHEAD
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bl rseq_syscall
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lwz r3,GPR3(r1)
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#endif
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mr r6,r3
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/* disable interrupts so current_thread_info()->flags can't change */
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LOAD_REG_IMMEDIATE(r10,MSR_KERNEL) /* doesn't include MSR_EE */
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/* Note: We don't bother telling lockdep about it */
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mtmsr r10
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lwz r9,TI_FLAGS(r2)
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li r8,-MAX_ERRNO
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andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
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bne- syscall_exit_work
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cmplw 0,r3,r8
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blt+ syscall_exit_cont
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lwz r11,_CCR(r1) /* Load CR */
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neg r3,r3
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oris r11,r11,0x1000 /* Set SO bit in CR */
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stw r11,_CCR(r1)
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syscall_exit_cont:
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lwz r8,_MSR(r1)
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#ifdef CONFIG_TRACE_IRQFLAGS
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/* If we are going to return from the syscall with interrupts
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* off, we trace that here. It shouldn't normally happen.
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*/
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andi. r10,r8,MSR_EE
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bne+ 1f
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stw r3,GPR3(r1)
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bl trace_hardirqs_off
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lwz r3,GPR3(r1)
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1:
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#endif /* CONFIG_TRACE_IRQFLAGS */
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#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
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/* If the process has its own DBCR0 value, load it up. The internal
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debug mode bit tells us that dbcr0 should be loaded. */
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lwz r0,THREAD+THREAD_DBCR0(r2)
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andis. r10,r0,DBCR0_IDM@h
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bnel- load_dbcr0
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#endif
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#ifdef CONFIG_44x
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BEGIN_MMU_FTR_SECTION
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lis r4,icache_44x_need_flush@ha
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lwz r5,icache_44x_need_flush@l(r4)
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cmplwi cr0,r5,0
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bne- 2f
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1:
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END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_47x)
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#endif /* CONFIG_44x */
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BEGIN_FTR_SECTION
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lwarx r7,0,r1
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END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
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stwcx. r0,0,r1 /* to clear the reservation */
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ACCOUNT_CPU_USER_EXIT(r2, r5, r7)
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#ifdef CONFIG_PPC_BOOK3S_32
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kuep_unlock r5, r7
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#endif
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kuap_check r2, r4
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lwz r4,_LINK(r1)
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lwz r5,_CCR(r1)
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mtlr r4
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mtcr r5
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lwz r7,_NIP(r1)
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lwz r2,GPR2(r1)
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lwz r1,GPR1(r1)
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syscall_exit_finish:
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#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
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mtspr SPRN_NRI, r0
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#endif
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mtspr SPRN_SRR0,r7
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mtspr SPRN_SRR1,r8
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RFI
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_ASM_NOKPROBE_SYMBOL(syscall_exit_finish)
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#ifdef CONFIG_44x
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2: li r7,0
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iccci r0,r0
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stw r7,icache_44x_need_flush@l(r4)
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b 1b
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#endif /* CONFIG_44x */
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66: li r3,-ENOSYS
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b ret_from_syscall
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.globl ret_from_fork
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ret_from_fork:
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REST_NVGPRS(r1)
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bl schedule_tail
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li r3,0
|
b ret_from_syscall
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.globl ret_from_kernel_thread
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ret_from_kernel_thread:
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REST_NVGPRS(r1)
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bl schedule_tail
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mtlr r14
|
mr r3,r15
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PPC440EP_ERR42
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blrl
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li r3,0
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b ret_from_syscall
|
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/* Traced system call support */
|
syscall_dotrace:
|
SAVE_NVGPRS(r1)
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li r0,0xc00
|
stw r0,_TRAP(r1)
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addi r3,r1,STACK_FRAME_OVERHEAD
|
bl do_syscall_trace_enter
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/*
|
* Restore argument registers possibly just changed.
|
* We use the return value of do_syscall_trace_enter
|
* for call number to look up in the table (r0).
|
*/
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mr r0,r3
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lwz r3,GPR3(r1)
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lwz r4,GPR4(r1)
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lwz r5,GPR5(r1)
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lwz r6,GPR6(r1)
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lwz r7,GPR7(r1)
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lwz r8,GPR8(r1)
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REST_NVGPRS(r1)
|
|
cmplwi r0,NR_syscalls
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/* Return code is already in r3 thanks to do_syscall_trace_enter() */
|
bge- ret_from_syscall
|
b syscall_dotrace_cont
|
|
syscall_exit_work:
|
andi. r0,r9,_TIF_RESTOREALL
|
beq+ 0f
|
REST_NVGPRS(r1)
|
b 2f
|
0: cmplw 0,r3,r8
|
blt+ 1f
|
andi. r0,r9,_TIF_NOERROR
|
bne- 1f
|
lwz r11,_CCR(r1) /* Load CR */
|
neg r3,r3
|
oris r11,r11,0x1000 /* Set SO bit in CR */
|
stw r11,_CCR(r1)
|
|
1: stw r6,RESULT(r1) /* Save result */
|
stw r3,GPR3(r1) /* Update return value */
|
2: andi. r0,r9,(_TIF_PERSYSCALL_MASK)
|
beq 4f
|
|
/* Clear per-syscall TIF flags if any are set. */
|
|
li r11,_TIF_PERSYSCALL_MASK
|
addi r12,r2,TI_FLAGS
|
3: lwarx r8,0,r12
|
andc r8,r8,r11
|
stwcx. r8,0,r12
|
bne- 3b
|
|
4: /* Anything which requires enabling interrupts? */
|
andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP)
|
beq ret_from_except
|
|
/* Re-enable interrupts. There is no need to trace that with
|
* lockdep as we are supposed to have IRQs on at this point
|
*/
|
ori r10,r10,MSR_EE
|
mtmsr r10
|
|
/* Save NVGPRS if they're not saved already */
|
lwz r4,_TRAP(r1)
|
andi. r4,r4,1
|
beq 5f
|
SAVE_NVGPRS(r1)
|
li r4,0xc00
|
stw r4,_TRAP(r1)
|
5:
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
bl do_syscall_trace_leave
|
b ret_from_except_full
|
|
/*
|
* System call was called from kernel. We get here with SRR1 in r9.
|
* Mark the exception as recoverable once we have retrieved SRR0,
|
* trap a warning and return ENOSYS with CR[SO] set.
|
*/
|
.globl ret_from_kernel_syscall
|
ret_from_kernel_syscall:
|
mfspr r9, SPRN_SRR0
|
mfspr r10, SPRN_SRR1
|
#if !defined(CONFIG_4xx) && !defined(CONFIG_BOOKE)
|
LOAD_REG_IMMEDIATE(r11, MSR_KERNEL & ~(MSR_IR|MSR_DR))
|
mtmsr r11
|
#endif
|
|
0: trap
|
EMIT_BUG_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
|
|
li r3, ENOSYS
|
crset so
|
#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
|
mtspr SPRN_NRI, r0
|
#endif
|
mtspr SPRN_SRR0, r9
|
mtspr SPRN_SRR1, r10
|
RFI
|
_ASM_NOKPROBE_SYMBOL(ret_from_kernel_syscall)
|
|
/*
|
* The fork/clone functions need to copy the full register set into
|
* the child process. Therefore we need to save all the nonvolatile
|
* registers (r13 - r31) before calling the C code.
|
*/
|
.globl ppc_fork
|
ppc_fork:
|
SAVE_NVGPRS(r1)
|
lwz r0,_TRAP(r1)
|
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
|
stw r0,_TRAP(r1) /* register set saved */
|
b sys_fork
|
|
.globl ppc_vfork
|
ppc_vfork:
|
SAVE_NVGPRS(r1)
|
lwz r0,_TRAP(r1)
|
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
|
stw r0,_TRAP(r1) /* register set saved */
|
b sys_vfork
|
|
.globl ppc_clone
|
ppc_clone:
|
SAVE_NVGPRS(r1)
|
lwz r0,_TRAP(r1)
|
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
|
stw r0,_TRAP(r1) /* register set saved */
|
b sys_clone
|
|
.globl ppc_clone3
|
ppc_clone3:
|
SAVE_NVGPRS(r1)
|
lwz r0,_TRAP(r1)
|
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
|
stw r0,_TRAP(r1) /* register set saved */
|
b sys_clone3
|
|
.globl ppc_swapcontext
|
ppc_swapcontext:
|
SAVE_NVGPRS(r1)
|
lwz r0,_TRAP(r1)
|
rlwinm r0,r0,0,0,30 /* clear LSB to indicate full */
|
stw r0,_TRAP(r1) /* register set saved */
|
b sys_swapcontext
|
|
/*
|
* Top-level page fault handling.
|
* This is in assembler because if do_page_fault tells us that
|
* it is a bad kernel page fault, we want to save the non-volatile
|
* registers before calling bad_page_fault.
|
*/
|
.globl handle_page_fault
|
handle_page_fault:
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
#ifdef CONFIG_PPC_BOOK3S_32
|
andis. r0,r5,DSISR_DABRMATCH@h
|
bne- handle_dabr_fault
|
#endif
|
bl do_page_fault
|
cmpwi r3,0
|
beq+ ret_from_except
|
SAVE_NVGPRS(r1)
|
lwz r0,_TRAP(r1)
|
clrrwi r0,r0,1
|
stw r0,_TRAP(r1)
|
mr r5,r3
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
lwz r4,_DAR(r1)
|
bl bad_page_fault
|
b ret_from_except_full
|
|
#ifdef CONFIG_PPC_BOOK3S_32
|
/* We have a data breakpoint exception - handle it */
|
handle_dabr_fault:
|
SAVE_NVGPRS(r1)
|
lwz r0,_TRAP(r1)
|
clrrwi r0,r0,1
|
stw r0,_TRAP(r1)
|
bl do_break
|
b ret_from_except_full
|
#endif
|
|
/*
|
* This routine switches between two different tasks. The process
|
* state of one is saved on its kernel stack. Then the state
|
* of the other is restored from its kernel stack. The memory
|
* management hardware is updated to the second process's state.
|
* Finally, we can return to the second process.
|
* On entry, r3 points to the THREAD for the current task, r4
|
* points to the THREAD for the new task.
|
*
|
* This routine is always called with interrupts disabled.
|
*
|
* Note: there are two ways to get to the "going out" portion
|
* of this code; either by coming in via the entry (_switch)
|
* or via "fork" which must set up an environment equivalent
|
* to the "_switch" path. If you change this , you'll have to
|
* change the fork code also.
|
*
|
* The code which creates the new task context is in 'copy_thread'
|
* in arch/ppc/kernel/process.c
|
*/
|
_GLOBAL(_switch)
|
stwu r1,-INT_FRAME_SIZE(r1)
|
mflr r0
|
stw r0,INT_FRAME_SIZE+4(r1)
|
/* r3-r12 are caller saved -- Cort */
|
SAVE_NVGPRS(r1)
|
stw r0,_NIP(r1) /* Return to switch caller */
|
mfmsr r11
|
li r0,MSR_FP /* Disable floating-point */
|
#ifdef CONFIG_ALTIVEC
|
BEGIN_FTR_SECTION
|
oris r0,r0,MSR_VEC@h /* Disable altivec */
|
mfspr r12,SPRN_VRSAVE /* save vrsave register value */
|
stw r12,THREAD+THREAD_VRSAVE(r2)
|
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
|
#endif /* CONFIG_ALTIVEC */
|
#ifdef CONFIG_SPE
|
BEGIN_FTR_SECTION
|
oris r0,r0,MSR_SPE@h /* Disable SPE */
|
mfspr r12,SPRN_SPEFSCR /* save spefscr register value */
|
stw r12,THREAD+THREAD_SPEFSCR(r2)
|
END_FTR_SECTION_IFSET(CPU_FTR_SPE)
|
#endif /* CONFIG_SPE */
|
and. r0,r0,r11 /* FP or altivec or SPE enabled? */
|
beq+ 1f
|
andc r11,r11,r0
|
mtmsr r11
|
isync
|
1: stw r11,_MSR(r1)
|
mfcr r10
|
stw r10,_CCR(r1)
|
stw r1,KSP(r3) /* Set old stack pointer */
|
|
kuap_check r2, r0
|
#ifdef CONFIG_SMP
|
/* We need a sync somewhere here to make sure that if the
|
* previous task gets rescheduled on another CPU, it sees all
|
* stores it has performed on this one.
|
*/
|
sync
|
#endif /* CONFIG_SMP */
|
|
tophys(r0,r4)
|
mtspr SPRN_SPRG_THREAD,r0 /* Update current THREAD phys addr */
|
lwz r1,KSP(r4) /* Load new stack pointer */
|
|
/* save the old current 'last' for return value */
|
mr r3,r2
|
addi r2,r4,-THREAD /* Update current */
|
|
#ifdef CONFIG_ALTIVEC
|
BEGIN_FTR_SECTION
|
lwz r0,THREAD+THREAD_VRSAVE(r2)
|
mtspr SPRN_VRSAVE,r0 /* if G4, restore VRSAVE reg */
|
END_FTR_SECTION_IFSET(CPU_FTR_ALTIVEC)
|
#endif /* CONFIG_ALTIVEC */
|
#ifdef CONFIG_SPE
|
BEGIN_FTR_SECTION
|
lwz r0,THREAD+THREAD_SPEFSCR(r2)
|
mtspr SPRN_SPEFSCR,r0 /* restore SPEFSCR reg */
|
END_FTR_SECTION_IFSET(CPU_FTR_SPE)
|
#endif /* CONFIG_SPE */
|
|
lwz r0,_CCR(r1)
|
mtcrf 0xFF,r0
|
/* r3-r12 are destroyed -- Cort */
|
REST_NVGPRS(r1)
|
|
lwz r4,_NIP(r1) /* Return to _switch caller in new task */
|
mtlr r4
|
addi r1,r1,INT_FRAME_SIZE
|
blr
|
|
.globl fast_exception_return
|
fast_exception_return:
|
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
|
andi. r10,r9,MSR_RI /* check for recoverable interrupt */
|
beq 1f /* if not, we've got problems */
|
#endif
|
|
2: REST_4GPRS(3, r11)
|
lwz r10,_CCR(r11)
|
REST_GPR(1, r11)
|
mtcr r10
|
lwz r10,_LINK(r11)
|
mtlr r10
|
/* Clear the exception_marker on the stack to avoid confusing stacktrace */
|
li r10, 0
|
stw r10, 8(r11)
|
REST_GPR(10, r11)
|
#if defined(CONFIG_PPC_8xx) && defined(CONFIG_PERF_EVENTS)
|
mtspr SPRN_NRI, r0
|
#endif
|
mtspr SPRN_SRR1,r9
|
mtspr SPRN_SRR0,r12
|
REST_GPR(9, r11)
|
REST_GPR(12, r11)
|
lwz r11,GPR11(r11)
|
RFI
|
_ASM_NOKPROBE_SYMBOL(fast_exception_return)
|
|
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
|
/* check if the exception happened in a restartable section */
|
1: lis r3,exc_exit_restart_end@ha
|
addi r3,r3,exc_exit_restart_end@l
|
cmplw r12,r3
|
bge 3f
|
lis r4,exc_exit_restart@ha
|
addi r4,r4,exc_exit_restart@l
|
cmplw r12,r4
|
blt 3f
|
lis r3,fee_restarts@ha
|
tophys(r3,r3)
|
lwz r5,fee_restarts@l(r3)
|
addi r5,r5,1
|
stw r5,fee_restarts@l(r3)
|
mr r12,r4 /* restart at exc_exit_restart */
|
b 2b
|
|
.section .bss
|
.align 2
|
fee_restarts:
|
.space 4
|
.previous
|
|
/* aargh, a nonrecoverable interrupt, panic */
|
/* aargh, we don't know which trap this is */
|
3:
|
li r10,-1
|
stw r10,_TRAP(r11)
|
addi r3,r1,STACK_FRAME_OVERHEAD
|
lis r10,MSR_KERNEL@h
|
ori r10,r10,MSR_KERNEL@l
|
bl transfer_to_handler_full
|
.long unrecoverable_exception
|
.long ret_from_except
|
#endif
|
|
.globl ret_from_except_full
|
ret_from_except_full:
|
REST_NVGPRS(r1)
|
/* fall through */
|
|
.globl ret_from_except
|
ret_from_except:
|
/* Hard-disable interrupts so that current_thread_info()->flags
|
* can't change between when we test it and when we return
|
* from the interrupt. */
|
/* Note: We don't bother telling lockdep about it */
|
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL)
|
mtmsr r10 /* disable interrupts */
|
|
lwz r3,_MSR(r1) /* Returning to user mode? */
|
andi. r0,r3,MSR_PR
|
beq resume_kernel
|
|
user_exc_return: /* r10 contains MSR_KERNEL here */
|
/* Check current_thread_info()->flags */
|
lwz r9,TI_FLAGS(r2)
|
andi. r0,r9,_TIF_USER_WORK_MASK
|
bne do_work
|
|
restore_user:
|
#if defined(CONFIG_4xx) || defined(CONFIG_BOOKE)
|
/* Check whether this process has its own DBCR0 value. The internal
|
debug mode bit tells us that dbcr0 should be loaded. */
|
lwz r0,THREAD+THREAD_DBCR0(r2)
|
andis. r10,r0,DBCR0_IDM@h
|
bnel- load_dbcr0
|
#endif
|
ACCOUNT_CPU_USER_EXIT(r2, r10, r11)
|
#ifdef CONFIG_PPC_BOOK3S_32
|
kuep_unlock r10, r11
|
#endif
|
|
b restore
|
|
/* N.B. the only way to get here is from the beq following ret_from_except. */
|
resume_kernel:
|
/* check current_thread_info, _TIF_EMULATE_STACK_STORE */
|
lwz r8,TI_FLAGS(r2)
|
andis. r0,r8,_TIF_EMULATE_STACK_STORE@h
|
beq+ 1f
|
|
addi r8,r1,INT_FRAME_SIZE /* Get the kprobed function entry */
|
|
lwz r3,GPR1(r1)
|
subi r3,r3,INT_FRAME_SIZE /* dst: Allocate a trampoline exception frame */
|
mr r4,r1 /* src: current exception frame */
|
mr r1,r3 /* Reroute the trampoline frame to r1 */
|
|
/* Copy from the original to the trampoline. */
|
li r5,INT_FRAME_SIZE/4 /* size: INT_FRAME_SIZE */
|
li r6,0 /* start offset: 0 */
|
mtctr r5
|
2: lwzx r0,r6,r4
|
stwx r0,r6,r3
|
addi r6,r6,4
|
bdnz 2b
|
|
/* Do real store operation to complete stwu */
|
lwz r5,GPR1(r1)
|
stw r8,0(r5)
|
|
/* Clear _TIF_EMULATE_STACK_STORE flag */
|
lis r11,_TIF_EMULATE_STACK_STORE@h
|
addi r5,r2,TI_FLAGS
|
0: lwarx r8,0,r5
|
andc r8,r8,r11
|
stwcx. r8,0,r5
|
bne- 0b
|
1:
|
|
#ifdef CONFIG_PREEMPTION
|
/* check current_thread_info->preempt_count */
|
lwz r0,TI_PREEMPT(r2)
|
cmpwi 0,r0,0 /* if non-zero, just restore regs and return */
|
bne restore_kuap
|
andi. r8,r8,_TIF_NEED_RESCHED
|
beq+ restore_kuap
|
lwz r3,_MSR(r1)
|
andi. r0,r3,MSR_EE /* interrupts off? */
|
beq restore_kuap /* don't schedule if so */
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
/* Lockdep thinks irqs are enabled, we need to call
|
* preempt_schedule_irq with IRQs off, so we inform lockdep
|
* now that we -did- turn them off already
|
*/
|
bl trace_hardirqs_off
|
#endif
|
bl preempt_schedule_irq
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
/* And now, to properly rebalance the above, we tell lockdep they
|
* are being turned back on, which will happen when we return
|
*/
|
bl trace_hardirqs_on
|
#endif
|
#endif /* CONFIG_PREEMPTION */
|
restore_kuap:
|
kuap_restore r1, r2, r9, r10, r0
|
|
/* interrupts are hard-disabled at this point */
|
restore:
|
#ifdef CONFIG_44x
|
BEGIN_MMU_FTR_SECTION
|
b 1f
|
END_MMU_FTR_SECTION_IFSET(MMU_FTR_TYPE_47x)
|
lis r4,icache_44x_need_flush@ha
|
lwz r5,icache_44x_need_flush@l(r4)
|
cmplwi cr0,r5,0
|
beq+ 1f
|
li r6,0
|
iccci r0,r0
|
stw r6,icache_44x_need_flush@l(r4)
|
1:
|
#endif /* CONFIG_44x */
|
|
lwz r9,_MSR(r1)
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
/* Lockdep doesn't know about the fact that IRQs are temporarily turned
|
* off in this assembly code while peeking at TI_FLAGS() and such. However
|
* we need to inform it if the exception turned interrupts off, and we
|
* are about to trun them back on.
|
*/
|
andi. r10,r9,MSR_EE
|
beq 1f
|
stwu r1,-32(r1)
|
mflr r0
|
stw r0,4(r1)
|
bl trace_hardirqs_on
|
addi r1, r1, 32
|
lwz r9,_MSR(r1)
|
1:
|
#endif /* CONFIG_TRACE_IRQFLAGS */
|
|
lwz r0,GPR0(r1)
|
lwz r2,GPR2(r1)
|
REST_4GPRS(3, r1)
|
REST_2GPRS(7, r1)
|
|
lwz r10,_XER(r1)
|
lwz r11,_CTR(r1)
|
mtspr SPRN_XER,r10
|
mtctr r11
|
|
BEGIN_FTR_SECTION
|
lwarx r11,0,r1
|
END_FTR_SECTION_IFSET(CPU_FTR_NEED_PAIRED_STWCX)
|
stwcx. r0,0,r1 /* to clear the reservation */
|
|
#if !(defined(CONFIG_4xx) || defined(CONFIG_BOOKE))
|
andi. r10,r9,MSR_RI /* check if this exception occurred */
|
beql nonrecoverable /* at a bad place (MSR:RI = 0) */
|
|
lwz r10,_CCR(r1)
|
lwz r11,_LINK(r1)
|
mtcrf 0xFF,r10
|
mtlr r11
|
|
/* Clear the exception_marker on the stack to avoid confusing stacktrace */
|
li r10, 0
|
stw r10, 8(r1)
|
/*
|
* Once we put values in SRR0 and SRR1, we are in a state
|
* where exceptions are not recoverable, since taking an
|
* exception will trash SRR0 and SRR1. Therefore we clear the
|
* MSR:RI bit to indicate this. If we do take an exception,
|
* we can't return to the point of the exception but we
|
* can restart the exception exit path at the label
|
* exc_exit_restart below. -- paulus
|
*/
|
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL & ~MSR_RI)
|
mtmsr r10 /* clear the RI bit */
|
.globl exc_exit_restart
|
exc_exit_restart:
|
lwz r12,_NIP(r1)
|
mtspr SPRN_SRR0,r12
|
mtspr SPRN_SRR1,r9
|
REST_4GPRS(9, r1)
|
lwz r1,GPR1(r1)
|
.globl exc_exit_restart_end
|
exc_exit_restart_end:
|
RFI
|
_ASM_NOKPROBE_SYMBOL(exc_exit_restart)
|
_ASM_NOKPROBE_SYMBOL(exc_exit_restart_end)
|
|
#else /* !(CONFIG_4xx || CONFIG_BOOKE) */
|
/*
|
* This is a bit different on 4xx/Book-E because it doesn't have
|
* the RI bit in the MSR.
|
* The TLB miss handler checks if we have interrupted
|
* the exception exit path and restarts it if so
|
* (well maybe one day it will... :).
|
*/
|
lwz r11,_LINK(r1)
|
mtlr r11
|
lwz r10,_CCR(r1)
|
mtcrf 0xff,r10
|
/* Clear the exception_marker on the stack to avoid confusing stacktrace */
|
li r10, 0
|
stw r10, 8(r1)
|
REST_2GPRS(9, r1)
|
.globl exc_exit_restart
|
exc_exit_restart:
|
lwz r11,_NIP(r1)
|
lwz r12,_MSR(r1)
|
mtspr SPRN_SRR0,r11
|
mtspr SPRN_SRR1,r12
|
REST_2GPRS(11, r1)
|
lwz r1,GPR1(r1)
|
.globl exc_exit_restart_end
|
exc_exit_restart_end:
|
rfi
|
b . /* prevent prefetch past rfi */
|
_ASM_NOKPROBE_SYMBOL(exc_exit_restart)
|
|
/*
|
* Returning from a critical interrupt in user mode doesn't need
|
* to be any different from a normal exception. For a critical
|
* interrupt in the kernel, we just return (without checking for
|
* preemption) since the interrupt may have happened at some crucial
|
* place (e.g. inside the TLB miss handler), and because we will be
|
* running with r1 pointing into critical_stack, not the current
|
* process's kernel stack (and therefore current_thread_info() will
|
* give the wrong answer).
|
* We have to restore various SPRs that may have been in use at the
|
* time of the critical interrupt.
|
*
|
*/
|
#ifdef CONFIG_40x
|
#define PPC_40x_TURN_OFF_MSR_DR \
|
/* avoid any possible TLB misses here by turning off MSR.DR, we \
|
* assume the instructions here are mapped by a pinned TLB entry */ \
|
li r10,MSR_IR; \
|
mtmsr r10; \
|
isync; \
|
tophys(r1, r1);
|
#else
|
#define PPC_40x_TURN_OFF_MSR_DR
|
#endif
|
|
#define RET_FROM_EXC_LEVEL(exc_lvl_srr0, exc_lvl_srr1, exc_lvl_rfi) \
|
REST_NVGPRS(r1); \
|
lwz r3,_MSR(r1); \
|
andi. r3,r3,MSR_PR; \
|
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL); \
|
bne user_exc_return; \
|
lwz r0,GPR0(r1); \
|
lwz r2,GPR2(r1); \
|
REST_4GPRS(3, r1); \
|
REST_2GPRS(7, r1); \
|
lwz r10,_XER(r1); \
|
lwz r11,_CTR(r1); \
|
mtspr SPRN_XER,r10; \
|
mtctr r11; \
|
stwcx. r0,0,r1; /* to clear the reservation */ \
|
lwz r11,_LINK(r1); \
|
mtlr r11; \
|
lwz r10,_CCR(r1); \
|
mtcrf 0xff,r10; \
|
PPC_40x_TURN_OFF_MSR_DR; \
|
lwz r9,_DEAR(r1); \
|
lwz r10,_ESR(r1); \
|
mtspr SPRN_DEAR,r9; \
|
mtspr SPRN_ESR,r10; \
|
lwz r11,_NIP(r1); \
|
lwz r12,_MSR(r1); \
|
mtspr exc_lvl_srr0,r11; \
|
mtspr exc_lvl_srr1,r12; \
|
lwz r9,GPR9(r1); \
|
lwz r12,GPR12(r1); \
|
lwz r10,GPR10(r1); \
|
lwz r11,GPR11(r1); \
|
lwz r1,GPR1(r1); \
|
exc_lvl_rfi; \
|
b .; /* prevent prefetch past exc_lvl_rfi */
|
|
#define RESTORE_xSRR(exc_lvl_srr0, exc_lvl_srr1) \
|
lwz r9,_##exc_lvl_srr0(r1); \
|
lwz r10,_##exc_lvl_srr1(r1); \
|
mtspr SPRN_##exc_lvl_srr0,r9; \
|
mtspr SPRN_##exc_lvl_srr1,r10;
|
|
#if defined(CONFIG_PPC_BOOK3E_MMU)
|
#ifdef CONFIG_PHYS_64BIT
|
#define RESTORE_MAS7 \
|
lwz r11,MAS7(r1); \
|
mtspr SPRN_MAS7,r11;
|
#else
|
#define RESTORE_MAS7
|
#endif /* CONFIG_PHYS_64BIT */
|
#define RESTORE_MMU_REGS \
|
lwz r9,MAS0(r1); \
|
lwz r10,MAS1(r1); \
|
lwz r11,MAS2(r1); \
|
mtspr SPRN_MAS0,r9; \
|
lwz r9,MAS3(r1); \
|
mtspr SPRN_MAS1,r10; \
|
lwz r10,MAS6(r1); \
|
mtspr SPRN_MAS2,r11; \
|
mtspr SPRN_MAS3,r9; \
|
mtspr SPRN_MAS6,r10; \
|
RESTORE_MAS7;
|
#elif defined(CONFIG_44x)
|
#define RESTORE_MMU_REGS \
|
lwz r9,MMUCR(r1); \
|
mtspr SPRN_MMUCR,r9;
|
#else
|
#define RESTORE_MMU_REGS
|
#endif
|
|
#ifdef CONFIG_40x
|
.globl ret_from_crit_exc
|
ret_from_crit_exc:
|
mfspr r9,SPRN_SPRG_THREAD
|
lis r10,saved_ksp_limit@ha;
|
lwz r10,saved_ksp_limit@l(r10);
|
tovirt(r9,r9);
|
stw r10,KSP_LIMIT(r9)
|
lis r9,crit_srr0@ha;
|
lwz r9,crit_srr0@l(r9);
|
lis r10,crit_srr1@ha;
|
lwz r10,crit_srr1@l(r10);
|
mtspr SPRN_SRR0,r9;
|
mtspr SPRN_SRR1,r10;
|
RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
|
_ASM_NOKPROBE_SYMBOL(ret_from_crit_exc)
|
#endif /* CONFIG_40x */
|
|
#ifdef CONFIG_BOOKE
|
.globl ret_from_crit_exc
|
ret_from_crit_exc:
|
mfspr r9,SPRN_SPRG_THREAD
|
lwz r10,SAVED_KSP_LIMIT(r1)
|
stw r10,KSP_LIMIT(r9)
|
RESTORE_xSRR(SRR0,SRR1);
|
RESTORE_MMU_REGS;
|
RET_FROM_EXC_LEVEL(SPRN_CSRR0, SPRN_CSRR1, PPC_RFCI)
|
_ASM_NOKPROBE_SYMBOL(ret_from_crit_exc)
|
|
.globl ret_from_debug_exc
|
ret_from_debug_exc:
|
mfspr r9,SPRN_SPRG_THREAD
|
lwz r10,SAVED_KSP_LIMIT(r1)
|
stw r10,KSP_LIMIT(r9)
|
RESTORE_xSRR(SRR0,SRR1);
|
RESTORE_xSRR(CSRR0,CSRR1);
|
RESTORE_MMU_REGS;
|
RET_FROM_EXC_LEVEL(SPRN_DSRR0, SPRN_DSRR1, PPC_RFDI)
|
_ASM_NOKPROBE_SYMBOL(ret_from_debug_exc)
|
|
.globl ret_from_mcheck_exc
|
ret_from_mcheck_exc:
|
mfspr r9,SPRN_SPRG_THREAD
|
lwz r10,SAVED_KSP_LIMIT(r1)
|
stw r10,KSP_LIMIT(r9)
|
RESTORE_xSRR(SRR0,SRR1);
|
RESTORE_xSRR(CSRR0,CSRR1);
|
RESTORE_xSRR(DSRR0,DSRR1);
|
RESTORE_MMU_REGS;
|
RET_FROM_EXC_LEVEL(SPRN_MCSRR0, SPRN_MCSRR1, PPC_RFMCI)
|
_ASM_NOKPROBE_SYMBOL(ret_from_mcheck_exc)
|
#endif /* CONFIG_BOOKE */
|
|
/*
|
* Load the DBCR0 value for a task that is being ptraced,
|
* having first saved away the global DBCR0. Note that r0
|
* has the dbcr0 value to set upon entry to this.
|
*/
|
load_dbcr0:
|
mfmsr r10 /* first disable debug exceptions */
|
rlwinm r10,r10,0,~MSR_DE
|
mtmsr r10
|
isync
|
mfspr r10,SPRN_DBCR0
|
lis r11,global_dbcr0@ha
|
addi r11,r11,global_dbcr0@l
|
#ifdef CONFIG_SMP
|
lwz r9,TASK_CPU(r2)
|
slwi r9,r9,3
|
add r11,r11,r9
|
#endif
|
stw r10,0(r11)
|
mtspr SPRN_DBCR0,r0
|
lwz r10,4(r11)
|
addi r10,r10,1
|
stw r10,4(r11)
|
li r11,-1
|
mtspr SPRN_DBSR,r11 /* clear all pending debug events */
|
blr
|
|
.section .bss
|
.align 4
|
.global global_dbcr0
|
global_dbcr0:
|
.space 8*NR_CPUS
|
.previous
|
#endif /* !(CONFIG_4xx || CONFIG_BOOKE) */
|
|
do_work: /* r10 contains MSR_KERNEL here */
|
andi. r0,r9,_TIF_NEED_RESCHED
|
beq do_user_signal
|
|
do_resched: /* r10 contains MSR_KERNEL here */
|
#ifdef CONFIG_TRACE_IRQFLAGS
|
bl trace_hardirqs_on
|
mfmsr r10
|
#endif
|
ori r10,r10,MSR_EE
|
mtmsr r10 /* hard-enable interrupts */
|
bl schedule
|
recheck:
|
/* Note: And we don't tell it we are disabling them again
|
* neither. Those disable/enable cycles used to peek at
|
* TI_FLAGS aren't advertised.
|
*/
|
LOAD_REG_IMMEDIATE(r10,MSR_KERNEL)
|
mtmsr r10 /* disable interrupts */
|
lwz r9,TI_FLAGS(r2)
|
andi. r0,r9,_TIF_NEED_RESCHED
|
bne- do_resched
|
andi. r0,r9,_TIF_USER_WORK_MASK
|
beq restore_user
|
do_user_signal: /* r10 contains MSR_KERNEL here */
|
ori r10,r10,MSR_EE
|
mtmsr r10 /* hard-enable interrupts */
|
/* save r13-r31 in the exception frame, if not already done */
|
lwz r3,_TRAP(r1)
|
andi. r0,r3,1
|
beq 2f
|
SAVE_NVGPRS(r1)
|
rlwinm r3,r3,0,0,30
|
stw r3,_TRAP(r1)
|
2: addi r3,r1,STACK_FRAME_OVERHEAD
|
mr r4,r9
|
bl do_notify_resume
|
REST_NVGPRS(r1)
|
b recheck
|
|
/*
|
* We come here when we are at the end of handling an exception
|
* that occurred at a place where taking an exception will lose
|
* state information, such as the contents of SRR0 and SRR1.
|
*/
|
nonrecoverable:
|
lis r10,exc_exit_restart_end@ha
|
addi r10,r10,exc_exit_restart_end@l
|
cmplw r12,r10
|
bge 3f
|
lis r11,exc_exit_restart@ha
|
addi r11,r11,exc_exit_restart@l
|
cmplw r12,r11
|
blt 3f
|
lis r10,ee_restarts@ha
|
lwz r12,ee_restarts@l(r10)
|
addi r12,r12,1
|
stw r12,ee_restarts@l(r10)
|
mr r12,r11 /* restart at exc_exit_restart */
|
blr
|
3: /* OK, we can't recover, kill this process */
|
lwz r3,_TRAP(r1)
|
andi. r0,r3,1
|
beq 5f
|
SAVE_NVGPRS(r1)
|
rlwinm r3,r3,0,0,30
|
stw r3,_TRAP(r1)
|
5: mfspr r2,SPRN_SPRG_THREAD
|
addi r2,r2,-THREAD
|
tovirt(r2,r2) /* set back r2 to current */
|
4: addi r3,r1,STACK_FRAME_OVERHEAD
|
bl unrecoverable_exception
|
/* shouldn't return */
|
b 4b
|
_ASM_NOKPROBE_SYMBOL(nonrecoverable)
|
|
.section .bss
|
.align 2
|
ee_restarts:
|
.space 4
|
.previous
|
|
/*
|
* PROM code for specific machines follows. Put it
|
* here so it's easy to add arch-specific sections later.
|
* -- Cort
|
*/
|
#ifdef CONFIG_PPC_RTAS
|
/*
|
* On CHRP, the Run-Time Abstraction Services (RTAS) have to be
|
* called with the MMU off.
|
*/
|
_GLOBAL(enter_rtas)
|
stwu r1,-INT_FRAME_SIZE(r1)
|
mflr r0
|
stw r0,INT_FRAME_SIZE+4(r1)
|
LOAD_REG_ADDR(r4, rtas)
|
lis r6,1f@ha /* physical return address for rtas */
|
addi r6,r6,1f@l
|
tophys(r6,r6)
|
tophys_novmstack r7, r1
|
lwz r8,RTASENTRY(r4)
|
lwz r4,RTASBASE(r4)
|
mfmsr r9
|
stw r9,8(r1)
|
LOAD_REG_IMMEDIATE(r0,MSR_KERNEL)
|
mtmsr r0 /* disable interrupts so SRR0/1 don't get trashed */
|
li r9,MSR_KERNEL & ~(MSR_IR|MSR_DR)
|
mtlr r6
|
stw r7, THREAD + RTAS_SP(r2)
|
mtspr SPRN_SRR0,r8
|
mtspr SPRN_SRR1,r9
|
RFI
|
1: tophys_novmstack r9, r1
|
#ifdef CONFIG_VMAP_STACK
|
li r0, MSR_KERNEL & ~MSR_IR /* can take DTLB miss */
|
mtmsr r0
|
isync
|
#endif
|
lwz r8,INT_FRAME_SIZE+4(r9) /* get return address */
|
lwz r9,8(r9) /* original msr value */
|
addi r1,r1,INT_FRAME_SIZE
|
li r0,0
|
tophys_novmstack r7, r2
|
stw r0, THREAD + RTAS_SP(r7)
|
mtspr SPRN_SRR0,r8
|
mtspr SPRN_SRR1,r9
|
RFI /* return to caller */
|
_ASM_NOKPROBE_SYMBOL(enter_rtas)
|
#endif /* CONFIG_PPC_RTAS */
|
