c5a8c0c99f
The STAB code used on Power3 and RS/64 uses a second scratch SPRG to save a GPR in order to decide whether to go to do_stab_bolted_* or to handle a normal data access exception. This prevents our scheme of freeing SPRG3 which is user visible for user uses since we cannot use SPRG0 which, on RS/64, seems to be read-only for supervisor mode (like POWER4). This reworks the STAB exception entry to use the PACA as temporary storage instead. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
283 lines
9.0 KiB
C
283 lines
9.0 KiB
C
#ifndef _ASM_POWERPC_EXCEPTION_H
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#define _ASM_POWERPC_EXCEPTION_H
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/*
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* Extracted from head_64.S
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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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*
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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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*
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* Adapted for 64bit PowerPC by Dave Engebretsen, Peter Bergner, and
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* Mike Corrigan {engebret|bergner|mikejc}@us.ibm.com
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*
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* This file contains the low-level support and setup for the
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* PowerPC-64 platform, including trap and interrupt dispatch.
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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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/*
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* The following macros define the code that appears as
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* the prologue to each of the exception handlers. They
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* are split into two parts to allow a single kernel binary
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* to be used for pSeries and iSeries.
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*
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* We make as much of the exception code common between native
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* exception handlers (including pSeries LPAR) and iSeries LPAR
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* implementations as possible.
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*/
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#define EX_R9 0
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#define EX_R10 8
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#define EX_R11 16
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#define EX_R12 24
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#define EX_R13 32
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#define EX_SRR0 40
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#define EX_DAR 48
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#define EX_DSISR 56
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#define EX_CCR 60
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#define EX_R3 64
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#define EX_LR 72
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/*
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* We're short on space and time in the exception prolog, so we can't
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* use the normal SET_REG_IMMEDIATE macro. Normally we just need the
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* low halfword of the address, but for Kdump we need the whole low
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* word.
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*/
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#define LOAD_HANDLER(reg, label) \
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addi reg,reg,(label)-_stext; /* virt addr of handler ... */
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#define EXCEPTION_PROLOG_1(area) \
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mfspr r13,SPRN_SPRG_PACA; /* get paca address into r13 */ \
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std r9,area+EX_R9(r13); /* save r9 - r12 */ \
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std r10,area+EX_R10(r13); \
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std r11,area+EX_R11(r13); \
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std r12,area+EX_R12(r13); \
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mfspr r9,SPRN_SPRG_SCRATCH0; \
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std r9,area+EX_R13(r13); \
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mfcr r9
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#define EXCEPTION_PROLOG_PSERIES_1(label) \
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ld r12,PACAKBASE(r13); /* get high part of &label */ \
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ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \
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mfspr r11,SPRN_SRR0; /* save SRR0 */ \
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LOAD_HANDLER(r12,label) \
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mtspr SPRN_SRR0,r12; \
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mfspr r12,SPRN_SRR1; /* and SRR1 */ \
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mtspr SPRN_SRR1,r10; \
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rfid; \
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b . /* prevent speculative execution */
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#define EXCEPTION_PROLOG_PSERIES(area, label) \
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EXCEPTION_PROLOG_1(area); \
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EXCEPTION_PROLOG_PSERIES_1(label);
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/*
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* The common exception prolog is used for all except a few exceptions
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* such as a segment miss on a kernel address. We have to be prepared
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* to take another exception from the point where we first touch the
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* kernel stack onwards.
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*
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* On entry r13 points to the paca, r9-r13 are saved in the paca,
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* r9 contains the saved CR, r11 and r12 contain the saved SRR0 and
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* SRR1, and relocation is on.
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*/
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#define EXCEPTION_PROLOG_COMMON(n, area) \
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andi. r10,r12,MSR_PR; /* See if coming from user */ \
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mr r10,r1; /* Save r1 */ \
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subi r1,r1,INT_FRAME_SIZE; /* alloc frame on kernel stack */ \
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beq- 1f; \
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ld r1,PACAKSAVE(r13); /* kernel stack to use */ \
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1: cmpdi cr1,r1,0; /* check if r1 is in userspace */ \
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bge- cr1,2f; /* abort if it is */ \
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b 3f; \
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2: li r1,(n); /* will be reloaded later */ \
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sth r1,PACA_TRAP_SAVE(r13); \
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b bad_stack; \
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3: std r9,_CCR(r1); /* save CR in stackframe */ \
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std r11,_NIP(r1); /* save SRR0 in stackframe */ \
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std r12,_MSR(r1); /* save SRR1 in stackframe */ \
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std r10,0(r1); /* make stack chain pointer */ \
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std r0,GPR0(r1); /* save r0 in stackframe */ \
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std r10,GPR1(r1); /* save r1 in stackframe */ \
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ACCOUNT_CPU_USER_ENTRY(r9, r10); \
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std r2,GPR2(r1); /* save r2 in stackframe */ \
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SAVE_4GPRS(3, r1); /* save r3 - r6 in stackframe */ \
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SAVE_2GPRS(7, r1); /* save r7, r8 in stackframe */ \
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ld r9,area+EX_R9(r13); /* move r9, r10 to stackframe */ \
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ld r10,area+EX_R10(r13); \
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std r9,GPR9(r1); \
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std r10,GPR10(r1); \
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ld r9,area+EX_R11(r13); /* move r11 - r13 to stackframe */ \
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ld r10,area+EX_R12(r13); \
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ld r11,area+EX_R13(r13); \
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std r9,GPR11(r1); \
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std r10,GPR12(r1); \
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std r11,GPR13(r1); \
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ld r2,PACATOC(r13); /* get kernel TOC into r2 */ \
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mflr r9; /* save LR in stackframe */ \
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std r9,_LINK(r1); \
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mfctr r10; /* save CTR in stackframe */ \
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std r10,_CTR(r1); \
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lbz r10,PACASOFTIRQEN(r13); \
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mfspr r11,SPRN_XER; /* save XER in stackframe */ \
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std r10,SOFTE(r1); \
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std r11,_XER(r1); \
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li r9,(n)+1; \
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std r9,_TRAP(r1); /* set trap number */ \
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li r10,0; \
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ld r11,exception_marker@toc(r2); \
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std r10,RESULT(r1); /* clear regs->result */ \
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std r11,STACK_FRAME_OVERHEAD-16(r1); /* mark the frame */
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/*
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* Exception vectors.
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*/
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#define STD_EXCEPTION_PSERIES(n, label) \
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. = n; \
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.globl label##_pSeries; \
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label##_pSeries: \
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HMT_MEDIUM; \
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mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
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EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
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#define HSTD_EXCEPTION_PSERIES(n, label) \
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. = n; \
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.globl label##_pSeries; \
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label##_pSeries: \
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HMT_MEDIUM; \
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mtspr SPRN_SPRG_SCRATCH0,r20; /* save r20 */ \
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mfspr r20,SPRN_HSRR0; /* copy HSRR0 to SRR0 */ \
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mtspr SPRN_SRR0,r20; \
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mfspr r20,SPRN_HSRR1; /* copy HSRR0 to SRR0 */ \
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mtspr SPRN_SRR1,r20; \
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mfspr r20,SPRN_SPRG_SCRATCH0; /* restore r20 */ \
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mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
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EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
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#define MASKABLE_EXCEPTION_PSERIES(n, label) \
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. = n; \
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.globl label##_pSeries; \
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label##_pSeries: \
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HMT_MEDIUM; \
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mtspr SPRN_SPRG_SCRATCH0,r13; /* save r13 */ \
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mfspr r13,SPRN_SPRG_PACA; /* get paca address into r13 */ \
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std r9,PACA_EXGEN+EX_R9(r13); /* save r9, r10 */ \
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std r10,PACA_EXGEN+EX_R10(r13); \
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lbz r10,PACASOFTIRQEN(r13); \
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mfcr r9; \
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cmpwi r10,0; \
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beq masked_interrupt; \
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mfspr r10,SPRN_SPRG_SCRATCH0; \
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std r10,PACA_EXGEN+EX_R13(r13); \
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std r11,PACA_EXGEN+EX_R11(r13); \
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std r12,PACA_EXGEN+EX_R12(r13); \
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ld r12,PACAKBASE(r13); /* get high part of &label */ \
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ld r10,PACAKMSR(r13); /* get MSR value for kernel */ \
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mfspr r11,SPRN_SRR0; /* save SRR0 */ \
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LOAD_HANDLER(r12,label##_common) \
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mtspr SPRN_SRR0,r12; \
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mfspr r12,SPRN_SRR1; /* and SRR1 */ \
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mtspr SPRN_SRR1,r10; \
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rfid; \
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b . /* prevent speculative execution */
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#ifdef CONFIG_PPC_ISERIES
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#define DISABLE_INTS \
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li r11,0; \
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stb r11,PACASOFTIRQEN(r13); \
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BEGIN_FW_FTR_SECTION; \
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stb r11,PACAHARDIRQEN(r13); \
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END_FW_FTR_SECTION_IFCLR(FW_FEATURE_ISERIES); \
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TRACE_DISABLE_INTS; \
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BEGIN_FW_FTR_SECTION; \
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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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END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
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#else
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#define DISABLE_INTS \
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li r11,0; \
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stb r11,PACASOFTIRQEN(r13); \
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stb r11,PACAHARDIRQEN(r13); \
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TRACE_DISABLE_INTS
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#endif /* CONFIG_PPC_ISERIES */
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#define ENABLE_INTS \
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ld r12,_MSR(r1); \
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mfmsr r11; \
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rlwimi r11,r12,0,MSR_EE; \
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mtmsrd r11,1
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#define STD_EXCEPTION_COMMON(trap, label, hdlr) \
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.align 7; \
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.globl label##_common; \
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label##_common: \
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EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
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DISABLE_INTS; \
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bl .save_nvgprs; \
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addi r3,r1,STACK_FRAME_OVERHEAD; \
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bl hdlr; \
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b .ret_from_except
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/*
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* Like STD_EXCEPTION_COMMON, but for exceptions that can occur
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* in the idle task and therefore need the special idle handling.
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*/
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#define STD_EXCEPTION_COMMON_IDLE(trap, label, hdlr) \
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.align 7; \
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.globl label##_common; \
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label##_common: \
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EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
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FINISH_NAP; \
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DISABLE_INTS; \
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bl .save_nvgprs; \
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addi r3,r1,STACK_FRAME_OVERHEAD; \
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bl hdlr; \
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b .ret_from_except
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#define STD_EXCEPTION_COMMON_LITE(trap, label, hdlr) \
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.align 7; \
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.globl label##_common; \
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label##_common: \
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EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN); \
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FINISH_NAP; \
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DISABLE_INTS; \
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BEGIN_FTR_SECTION \
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bl .ppc64_runlatch_on; \
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END_FTR_SECTION_IFSET(CPU_FTR_CTRL) \
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addi r3,r1,STACK_FRAME_OVERHEAD; \
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bl hdlr; \
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b .ret_from_except_lite
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/*
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* When the idle code in power4_idle puts the CPU into NAP mode,
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* it has to do so in a loop, and relies on the external interrupt
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* and decrementer interrupt entry code to get it out of the loop.
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* It sets the _TLF_NAPPING bit in current_thread_info()->local_flags
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* to signal that it is in the loop and needs help to get out.
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*/
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#ifdef CONFIG_PPC_970_NAP
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#define FINISH_NAP \
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BEGIN_FTR_SECTION \
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clrrdi r11,r1,THREAD_SHIFT; \
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ld r9,TI_LOCAL_FLAGS(r11); \
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andi. r10,r9,_TLF_NAPPING; \
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bnel power4_fixup_nap; \
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END_FTR_SECTION_IFSET(CPU_FTR_CAN_NAP)
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#else
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#define FINISH_NAP
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#endif
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#endif /* _ASM_POWERPC_EXCEPTION_H */
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