1006 lines
28 KiB
ArmAsm
1006 lines
28 KiB
ArmAsm
/*
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* Low-level system-call handling, trap handlers and context-switching
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*
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* Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
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* Copyright (C) 2008-2009 PetaLogix
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* Copyright (C) 2003 John Williams <jwilliams@itee.uq.edu.au>
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* Copyright (C) 2001,2002 NEC Corporation
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* Copyright (C) 2001,2002 Miles Bader <miles@gnu.org>
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*
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* This file is subject to the terms and conditions of the GNU General
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* Public License. See the file COPYING in the main directory of this
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* archive for more details.
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*
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* Written by Miles Bader <miles@gnu.org>
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* Heavily modified by John Williams for Microblaze
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*/
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#include <linux/sys.h>
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#include <linux/linkage.h>
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#include <asm/entry.h>
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#include <asm/current.h>
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#include <asm/processor.h>
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#include <asm/exceptions.h>
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#include <asm/asm-offsets.h>
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#include <asm/thread_info.h>
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#include <asm/page.h>
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#include <asm/unistd.h>
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#include <linux/errno.h>
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#include <asm/signal.h>
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#undef DEBUG
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#ifdef DEBUG
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/* Create space for syscalls counting. */
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.section .data
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.global syscall_debug_table
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.align 4
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syscall_debug_table:
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.space (__NR_syscalls * 4)
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#endif /* DEBUG */
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#define C_ENTRY(name) .globl name; .align 4; name
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/*
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* Various ways of setting and clearing BIP in flags reg.
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* This is mucky, but necessary using microblaze version that
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* allows msr ops to write to BIP
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*/
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#if CONFIG_XILINX_MICROBLAZE0_USE_MSR_INSTR
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.macro clear_bip
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msrclr r0, MSR_BIP
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.endm
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.macro set_bip
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msrset r0, MSR_BIP
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.endm
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.macro clear_eip
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msrclr r0, MSR_EIP
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.endm
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.macro set_ee
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msrset r0, MSR_EE
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.endm
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.macro disable_irq
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msrclr r0, MSR_IE
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.endm
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.macro enable_irq
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msrset r0, MSR_IE
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.endm
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.macro set_ums
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msrset r0, MSR_UMS
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msrclr r0, MSR_VMS
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.endm
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.macro set_vms
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msrclr r0, MSR_UMS
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msrset r0, MSR_VMS
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.endm
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.macro clear_ums
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msrclr r0, MSR_UMS
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.endm
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.macro clear_vms_ums
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msrclr r0, MSR_VMS | MSR_UMS
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.endm
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#else
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.macro clear_bip
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mfs r11, rmsr
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andi r11, r11, ~MSR_BIP
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mts rmsr, r11
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.endm
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.macro set_bip
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mfs r11, rmsr
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ori r11, r11, MSR_BIP
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mts rmsr, r11
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.endm
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.macro clear_eip
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mfs r11, rmsr
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andi r11, r11, ~MSR_EIP
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mts rmsr, r11
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.endm
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.macro set_ee
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mfs r11, rmsr
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ori r11, r11, MSR_EE
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mts rmsr, r11
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.endm
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.macro disable_irq
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mfs r11, rmsr
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andi r11, r11, ~MSR_IE
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mts rmsr, r11
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.endm
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.macro enable_irq
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mfs r11, rmsr
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ori r11, r11, MSR_IE
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mts rmsr, r11
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.endm
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.macro set_ums
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mfs r11, rmsr
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ori r11, r11, MSR_VMS
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andni r11, r11, MSR_UMS
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mts rmsr, r11
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.endm
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.macro set_vms
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mfs r11, rmsr
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ori r11, r11, MSR_VMS
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andni r11, r11, MSR_UMS
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mts rmsr, r11
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.endm
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.macro clear_ums
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mfs r11, rmsr
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andni r11, r11, MSR_UMS
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mts rmsr,r11
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.endm
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.macro clear_vms_ums
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mfs r11, rmsr
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andni r11, r11, (MSR_VMS|MSR_UMS)
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mts rmsr,r11
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.endm
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#endif
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/* Define how to call high-level functions. With MMU, virtual mode must be
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* enabled when calling the high-level function. Clobbers R11.
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* VM_ON, VM_OFF, DO_JUMP_BIPCLR, DO_CALL
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*/
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/* turn on virtual protected mode save */
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#define VM_ON \
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set_ums; \
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rted r0, 2f; \
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nop; \
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2:
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/* turn off virtual protected mode save and user mode save*/
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#define VM_OFF \
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clear_vms_ums; \
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rted r0, TOPHYS(1f); \
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nop; \
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1:
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#define SAVE_REGS \
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swi r2, r1, PT_R2; /* Save SDA */ \
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swi r3, r1, PT_R3; \
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swi r4, r1, PT_R4; \
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swi r5, r1, PT_R5; \
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swi r6, r1, PT_R6; \
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swi r7, r1, PT_R7; \
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swi r8, r1, PT_R8; \
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swi r9, r1, PT_R9; \
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swi r10, r1, PT_R10; \
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swi r11, r1, PT_R11; /* save clobbered regs after rval */\
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swi r12, r1, PT_R12; \
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swi r13, r1, PT_R13; /* Save SDA2 */ \
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swi r14, r1, PT_PC; /* PC, before IRQ/trap */ \
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swi r15, r1, PT_R15; /* Save LP */ \
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swi r16, r1, PT_R16; \
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swi r17, r1, PT_R17; \
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swi r18, r1, PT_R18; /* Save asm scratch reg */ \
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swi r19, r1, PT_R19; \
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swi r20, r1, PT_R20; \
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swi r21, r1, PT_R21; \
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swi r22, r1, PT_R22; \
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swi r23, r1, PT_R23; \
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swi r24, r1, PT_R24; \
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swi r25, r1, PT_R25; \
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swi r26, r1, PT_R26; \
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swi r27, r1, PT_R27; \
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swi r28, r1, PT_R28; \
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swi r29, r1, PT_R29; \
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swi r30, r1, PT_R30; \
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swi r31, r1, PT_R31; /* Save current task reg */ \
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mfs r11, rmsr; /* save MSR */ \
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swi r11, r1, PT_MSR;
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#define RESTORE_REGS \
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lwi r11, r1, PT_MSR; \
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mts rmsr , r11; \
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lwi r2, r1, PT_R2; /* restore SDA */ \
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lwi r3, r1, PT_R3; \
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lwi r4, r1, PT_R4; \
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lwi r5, r1, PT_R5; \
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lwi r6, r1, PT_R6; \
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lwi r7, r1, PT_R7; \
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lwi r8, r1, PT_R8; \
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lwi r9, r1, PT_R9; \
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lwi r10, r1, PT_R10; \
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lwi r11, r1, PT_R11; /* restore clobbered regs after rval */\
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lwi r12, r1, PT_R12; \
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lwi r13, r1, PT_R13; /* restore SDA2 */ \
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lwi r14, r1, PT_PC; /* RESTORE_LINK PC, before IRQ/trap */\
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lwi r15, r1, PT_R15; /* restore LP */ \
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lwi r16, r1, PT_R16; \
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lwi r17, r1, PT_R17; \
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lwi r18, r1, PT_R18; /* restore asm scratch reg */ \
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lwi r19, r1, PT_R19; \
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lwi r20, r1, PT_R20; \
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lwi r21, r1, PT_R21; \
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lwi r22, r1, PT_R22; \
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lwi r23, r1, PT_R23; \
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lwi r24, r1, PT_R24; \
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lwi r25, r1, PT_R25; \
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lwi r26, r1, PT_R26; \
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lwi r27, r1, PT_R27; \
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lwi r28, r1, PT_R28; \
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lwi r29, r1, PT_R29; \
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lwi r30, r1, PT_R30; \
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lwi r31, r1, PT_R31; /* Restore cur task reg */
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#define SAVE_STATE \
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swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* save stack */ \
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/* See if already in kernel mode.*/ \
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mfs r1, rmsr; \
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andi r1, r1, MSR_UMS; \
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bnei r1, 1f; \
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/* Kernel-mode state save. */ \
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/* Reload kernel stack-ptr. */ \
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lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); \
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/* FIXME: I can add these two lines to one */ \
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/* tophys(r1,r1); */ \
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/* addik r1, r1, -PT_SIZE; */ \
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addik r1, r1, CONFIG_KERNEL_BASE_ADDR - CONFIG_KERNEL_START - PT_SIZE; \
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SAVE_REGS \
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brid 2f; \
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swi r1, r1, PT_MODE; \
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1: /* User-mode state save. */ \
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lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */\
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tophys(r1,r1); \
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lwi r1, r1, TS_THREAD_INFO; /* get the thread info */ \
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/* MS these three instructions can be added to one */ \
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/* addik r1, r1, THREAD_SIZE; */ \
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/* tophys(r1,r1); */ \
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/* addik r1, r1, -PT_SIZE; */ \
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addik r1, r1, THREAD_SIZE + CONFIG_KERNEL_BASE_ADDR - CONFIG_KERNEL_START - PT_SIZE; \
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SAVE_REGS \
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lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP)); \
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swi r11, r1, PT_R1; /* Store user SP. */ \
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swi r0, r1, PT_MODE; /* Was in user-mode. */ \
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/* MS: I am clearing UMS even in case when I come from kernel space */ \
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clear_ums; \
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2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
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.text
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/*
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* User trap.
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*
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* System calls are handled here.
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*
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* Syscall protocol:
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* Syscall number in r12, args in r5-r10
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* Return value in r3
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*
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* Trap entered via brki instruction, so BIP bit is set, and interrupts
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* are masked. This is nice, means we don't have to CLI before state save
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*/
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C_ENTRY(_user_exception):
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swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)) /* save stack */
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addi r14, r14, 4 /* return address is 4 byte after call */
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lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
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tophys(r1,r1);
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lwi r1, r1, TS_THREAD_INFO; /* get stack from task_struct */
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/* calculate kernel stack pointer from task struct 8k */
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addik r1, r1, THREAD_SIZE;
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tophys(r1,r1);
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addik r1, r1, -PT_SIZE; /* Make room on the stack. */
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SAVE_REGS
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swi r0, r1, PT_R3
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swi r0, r1, PT_R4
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swi r0, r1, PT_MODE; /* Was in user-mode. */
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lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
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swi r11, r1, PT_R1; /* Store user SP. */
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clear_ums;
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2: lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
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/* Save away the syscall number. */
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swi r12, r1, PT_R0;
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tovirt(r1,r1)
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/* where the trap should return need -8 to adjust for rtsd r15, 8*/
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/* Jump to the appropriate function for the system call number in r12
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* (r12 is not preserved), or return an error if r12 is not valid. The LP
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* register should point to the location where
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* the called function should return. [note that MAKE_SYS_CALL uses label 1] */
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/* Step into virtual mode */
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rtbd r0, 3f
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nop
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3:
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lwi r11, CURRENT_TASK, TS_THREAD_INFO /* get thread info */
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lwi r11, r11, TI_FLAGS /* get flags in thread info */
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andi r11, r11, _TIF_WORK_SYSCALL_MASK
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beqi r11, 4f
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addik r3, r0, -ENOSYS
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swi r3, r1, PT_R3
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brlid r15, do_syscall_trace_enter
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addik r5, r1, PT_R0
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# do_syscall_trace_enter returns the new syscall nr.
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addk r12, r0, r3
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lwi r5, r1, PT_R5;
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lwi r6, r1, PT_R6;
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lwi r7, r1, PT_R7;
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lwi r8, r1, PT_R8;
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lwi r9, r1, PT_R9;
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lwi r10, r1, PT_R10;
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4:
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/* Jump to the appropriate function for the system call number in r12
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* (r12 is not preserved), or return an error if r12 is not valid.
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* The LP register should point to the location where the called function
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* should return. [note that MAKE_SYS_CALL uses label 1] */
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/* See if the system call number is valid */
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blti r12, 5f
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addi r11, r12, -__NR_syscalls;
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bgei r11, 5f;
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/* Figure out which function to use for this system call. */
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/* Note Microblaze barrel shift is optional, so don't rely on it */
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add r12, r12, r12; /* convert num -> ptr */
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add r12, r12, r12;
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addi r30, r0, 1 /* restarts allowed */
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#ifdef DEBUG
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/* Trac syscalls and stored them to syscall_debug_table */
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/* The first syscall location stores total syscall number */
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lwi r3, r0, syscall_debug_table
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addi r3, r3, 1
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swi r3, r0, syscall_debug_table
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lwi r3, r12, syscall_debug_table
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addi r3, r3, 1
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swi r3, r12, syscall_debug_table
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#endif
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# Find and jump into the syscall handler.
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lwi r12, r12, sys_call_table
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/* where the trap should return need -8 to adjust for rtsd r15, 8 */
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addi r15, r0, ret_from_trap-8
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bra r12
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/* The syscall number is invalid, return an error. */
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5:
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braid ret_from_trap
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addi r3, r0, -ENOSYS;
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/* Entry point used to return from a syscall/trap */
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/* We re-enable BIP bit before state restore */
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C_ENTRY(ret_from_trap):
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swi r3, r1, PT_R3
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swi r4, r1, PT_R4
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lwi r11, r1, PT_MODE;
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/* See if returning to kernel mode, if so, skip resched &c. */
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bnei r11, 2f;
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/* We're returning to user mode, so check for various conditions that
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* trigger rescheduling. */
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/* FIXME: Restructure all these flag checks. */
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lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
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lwi r11, r11, TI_FLAGS; /* get flags in thread info */
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andi r11, r11, _TIF_WORK_SYSCALL_MASK
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beqi r11, 1f
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brlid r15, do_syscall_trace_leave
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addik r5, r1, PT_R0
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1:
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/* We're returning to user mode, so check for various conditions that
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* trigger rescheduling. */
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/* get thread info from current task */
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lwi r11, CURRENT_TASK, TS_THREAD_INFO;
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lwi r19, r11, TI_FLAGS; /* get flags in thread info */
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andi r11, r19, _TIF_NEED_RESCHED;
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beqi r11, 5f;
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bralid r15, schedule; /* Call scheduler */
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nop; /* delay slot */
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bri 1b
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/* Maybe handle a signal */
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5:
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andi r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
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beqi r11, 4f; /* Signals to handle, handle them */
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addik r5, r1, 0; /* Arg 1: struct pt_regs *regs */
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bralid r15, do_notify_resume; /* Handle any signals */
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add r6, r30, r0; /* Arg 2: int in_syscall */
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add r30, r0, r0 /* no more restarts */
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bri 1b
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/* Finally, return to user state. */
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4: set_bip; /* Ints masked for state restore */
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swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
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VM_OFF;
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tophys(r1,r1);
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RESTORE_REGS;
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addik r1, r1, PT_SIZE /* Clean up stack space. */
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lwi r1, r1, PT_R1 - PT_SIZE;/* Restore user stack pointer. */
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bri 6f;
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/* Return to kernel state. */
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2: set_bip; /* Ints masked for state restore */
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VM_OFF;
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tophys(r1,r1);
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RESTORE_REGS;
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addik r1, r1, PT_SIZE /* Clean up stack space. */
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tovirt(r1,r1);
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6:
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TRAP_return: /* Make global symbol for debugging */
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rtbd r14, 0; /* Instructions to return from an IRQ */
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nop;
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/* This the initial entry point for a new child thread, with an appropriate
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stack in place that makes it look the the child is in the middle of an
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syscall. This function is actually `returned to' from switch_thread
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(copy_thread makes ret_from_fork the return address in each new thread's
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saved context). */
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C_ENTRY(ret_from_fork):
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bralid r15, schedule_tail; /* ...which is schedule_tail's arg */
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add r5, r3, r0; /* switch_thread returns the prev task */
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/* ( in the delay slot ) */
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brid ret_from_trap; /* Do normal trap return */
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add r3, r0, r0; /* Child's fork call should return 0. */
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C_ENTRY(ret_from_kernel_thread):
|
|
bralid r15, schedule_tail; /* ...which is schedule_tail's arg */
|
|
add r5, r3, r0; /* switch_thread returns the prev task */
|
|
/* ( in the delay slot ) */
|
|
brald r15, r20 /* fn was left in r20 */
|
|
addk r5, r0, r19 /* ... and argument - in r19 */
|
|
brid ret_from_trap
|
|
add r3, r0, r0
|
|
|
|
C_ENTRY(sys_rt_sigreturn_wrapper):
|
|
addik r30, r0, 0 /* no restarts */
|
|
brid sys_rt_sigreturn /* Do real work */
|
|
addik r5, r1, 0; /* add user context as 1st arg */
|
|
|
|
/*
|
|
* HW EXCEPTION rutine start
|
|
*/
|
|
C_ENTRY(full_exception_trap):
|
|
/* adjust exception address for privileged instruction
|
|
* for finding where is it */
|
|
addik r17, r17, -4
|
|
SAVE_STATE /* Save registers */
|
|
/* PC, before IRQ/trap - this is one instruction above */
|
|
swi r17, r1, PT_PC;
|
|
tovirt(r1,r1)
|
|
/* FIXME this can be store directly in PT_ESR reg.
|
|
* I tested it but there is a fault */
|
|
/* where the trap should return need -8 to adjust for rtsd r15, 8 */
|
|
addik r15, r0, ret_from_exc - 8
|
|
mfs r6, resr
|
|
mfs r7, rfsr; /* save FSR */
|
|
mts rfsr, r0; /* Clear sticky fsr */
|
|
rted r0, full_exception
|
|
addik r5, r1, 0 /* parameter struct pt_regs * regs */
|
|
|
|
/*
|
|
* Unaligned data trap.
|
|
*
|
|
* Unaligned data trap last on 4k page is handled here.
|
|
*
|
|
* Trap entered via exception, so EE bit is set, and interrupts
|
|
* are masked. This is nice, means we don't have to CLI before state save
|
|
*
|
|
* The assembler routine is in "arch/microblaze/kernel/hw_exception_handler.S"
|
|
*/
|
|
C_ENTRY(unaligned_data_trap):
|
|
/* MS: I have to save r11 value and then restore it because
|
|
* set_bit, clear_eip, set_ee use r11 as temp register if MSR
|
|
* instructions are not used. We don't need to do if MSR instructions
|
|
* are used and they use r0 instead of r11.
|
|
* I am using ENTRY_SP which should be primary used only for stack
|
|
* pointer saving. */
|
|
swi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
|
|
set_bip; /* equalize initial state for all possible entries */
|
|
clear_eip;
|
|
set_ee;
|
|
lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
|
|
SAVE_STATE /* Save registers.*/
|
|
/* PC, before IRQ/trap - this is one instruction above */
|
|
swi r17, r1, PT_PC;
|
|
tovirt(r1,r1)
|
|
/* where the trap should return need -8 to adjust for rtsd r15, 8 */
|
|
addik r15, r0, ret_from_exc-8
|
|
mfs r3, resr /* ESR */
|
|
mfs r4, rear /* EAR */
|
|
rtbd r0, _unaligned_data_exception
|
|
addik r7, r1, 0 /* parameter struct pt_regs * regs */
|
|
|
|
/*
|
|
* Page fault traps.
|
|
*
|
|
* If the real exception handler (from hw_exception_handler.S) didn't find
|
|
* the mapping for the process, then we're thrown here to handle such situation.
|
|
*
|
|
* Trap entered via exceptions, so EE bit is set, and interrupts
|
|
* are masked. This is nice, means we don't have to CLI before state save
|
|
*
|
|
* Build a standard exception frame for TLB Access errors. All TLB exceptions
|
|
* will bail out to this point if they can't resolve the lightweight TLB fault.
|
|
*
|
|
* The C function called is in "arch/microblaze/mm/fault.c", declared as:
|
|
* void do_page_fault(struct pt_regs *regs,
|
|
* unsigned long address,
|
|
* unsigned long error_code)
|
|
*/
|
|
/* data and intruction trap - which is choose is resolved int fault.c */
|
|
C_ENTRY(page_fault_data_trap):
|
|
SAVE_STATE /* Save registers.*/
|
|
/* PC, before IRQ/trap - this is one instruction above */
|
|
swi r17, r1, PT_PC;
|
|
tovirt(r1,r1)
|
|
/* where the trap should return need -8 to adjust for rtsd r15, 8 */
|
|
addik r15, r0, ret_from_exc-8
|
|
mfs r6, rear /* parameter unsigned long address */
|
|
mfs r7, resr /* parameter unsigned long error_code */
|
|
rted r0, do_page_fault
|
|
addik r5, r1, 0 /* parameter struct pt_regs * regs */
|
|
|
|
C_ENTRY(page_fault_instr_trap):
|
|
SAVE_STATE /* Save registers.*/
|
|
/* PC, before IRQ/trap - this is one instruction above */
|
|
swi r17, r1, PT_PC;
|
|
tovirt(r1,r1)
|
|
/* where the trap should return need -8 to adjust for rtsd r15, 8 */
|
|
addik r15, r0, ret_from_exc-8
|
|
mfs r6, rear /* parameter unsigned long address */
|
|
ori r7, r0, 0 /* parameter unsigned long error_code */
|
|
rted r0, do_page_fault
|
|
addik r5, r1, 0 /* parameter struct pt_regs * regs */
|
|
|
|
/* Entry point used to return from an exception. */
|
|
C_ENTRY(ret_from_exc):
|
|
lwi r11, r1, PT_MODE;
|
|
bnei r11, 2f; /* See if returning to kernel mode, */
|
|
/* ... if so, skip resched &c. */
|
|
|
|
/* We're returning to user mode, so check for various conditions that
|
|
trigger rescheduling. */
|
|
1:
|
|
lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
|
|
lwi r19, r11, TI_FLAGS; /* get flags in thread info */
|
|
andi r11, r19, _TIF_NEED_RESCHED;
|
|
beqi r11, 5f;
|
|
|
|
/* Call the scheduler before returning from a syscall/trap. */
|
|
bralid r15, schedule; /* Call scheduler */
|
|
nop; /* delay slot */
|
|
bri 1b
|
|
|
|
/* Maybe handle a signal */
|
|
5: andi r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
|
|
beqi r11, 4f; /* Signals to handle, handle them */
|
|
|
|
/*
|
|
* Handle a signal return; Pending signals should be in r18.
|
|
*
|
|
* Not all registers are saved by the normal trap/interrupt entry
|
|
* points (for instance, call-saved registers (because the normal
|
|
* C-compiler calling sequence in the kernel makes sure they're
|
|
* preserved), and call-clobbered registers in the case of
|
|
* traps), but signal handlers may want to examine or change the
|
|
* complete register state. Here we save anything not saved by
|
|
* the normal entry sequence, so that it may be safely restored
|
|
* (in a possibly modified form) after do_notify_resume returns. */
|
|
addik r5, r1, 0; /* Arg 1: struct pt_regs *regs */
|
|
bralid r15, do_notify_resume; /* Handle any signals */
|
|
addi r6, r0, 0; /* Arg 2: int in_syscall */
|
|
bri 1b
|
|
|
|
/* Finally, return to user state. */
|
|
4: set_bip; /* Ints masked for state restore */
|
|
swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
|
|
VM_OFF;
|
|
tophys(r1,r1);
|
|
|
|
RESTORE_REGS;
|
|
addik r1, r1, PT_SIZE /* Clean up stack space. */
|
|
|
|
lwi r1, r1, PT_R1 - PT_SIZE; /* Restore user stack pointer. */
|
|
bri 6f;
|
|
/* Return to kernel state. */
|
|
2: set_bip; /* Ints masked for state restore */
|
|
VM_OFF;
|
|
tophys(r1,r1);
|
|
RESTORE_REGS;
|
|
addik r1, r1, PT_SIZE /* Clean up stack space. */
|
|
|
|
tovirt(r1,r1);
|
|
6:
|
|
EXC_return: /* Make global symbol for debugging */
|
|
rtbd r14, 0; /* Instructions to return from an IRQ */
|
|
nop;
|
|
|
|
/*
|
|
* HW EXCEPTION rutine end
|
|
*/
|
|
|
|
/*
|
|
* Hardware maskable interrupts.
|
|
*
|
|
* The stack-pointer (r1) should have already been saved to the memory
|
|
* location PER_CPU(ENTRY_SP).
|
|
*/
|
|
C_ENTRY(_interrupt):
|
|
/* MS: we are in physical address */
|
|
/* Save registers, switch to proper stack, convert SP to virtual.*/
|
|
swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
|
|
/* MS: See if already in kernel mode. */
|
|
mfs r1, rmsr
|
|
nop
|
|
andi r1, r1, MSR_UMS
|
|
bnei r1, 1f
|
|
|
|
/* Kernel-mode state save. */
|
|
lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
|
|
tophys(r1,r1); /* MS: I have in r1 physical address where stack is */
|
|
/* save registers */
|
|
/* MS: Make room on the stack -> activation record */
|
|
addik r1, r1, -PT_SIZE;
|
|
SAVE_REGS
|
|
brid 2f;
|
|
swi r1, r1, PT_MODE; /* 0 - user mode, 1 - kernel mode */
|
|
1:
|
|
/* User-mode state save. */
|
|
/* MS: get the saved current */
|
|
lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
|
|
tophys(r1,r1);
|
|
lwi r1, r1, TS_THREAD_INFO;
|
|
addik r1, r1, THREAD_SIZE;
|
|
tophys(r1,r1);
|
|
/* save registers */
|
|
addik r1, r1, -PT_SIZE;
|
|
SAVE_REGS
|
|
/* calculate mode */
|
|
swi r0, r1, PT_MODE;
|
|
lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
|
|
swi r11, r1, PT_R1;
|
|
clear_ums;
|
|
2:
|
|
lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
|
|
tovirt(r1,r1)
|
|
addik r15, r0, irq_call;
|
|
irq_call:rtbd r0, do_IRQ;
|
|
addik r5, r1, 0;
|
|
|
|
/* MS: we are in virtual mode */
|
|
ret_from_irq:
|
|
lwi r11, r1, PT_MODE;
|
|
bnei r11, 2f;
|
|
|
|
1:
|
|
lwi r11, CURRENT_TASK, TS_THREAD_INFO;
|
|
lwi r19, r11, TI_FLAGS; /* MS: get flags from thread info */
|
|
andi r11, r19, _TIF_NEED_RESCHED;
|
|
beqi r11, 5f
|
|
bralid r15, schedule;
|
|
nop; /* delay slot */
|
|
bri 1b
|
|
|
|
/* Maybe handle a signal */
|
|
5: andi r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
|
|
beqid r11, no_intr_resched
|
|
/* Handle a signal return; Pending signals should be in r18. */
|
|
addik r5, r1, 0; /* Arg 1: struct pt_regs *regs */
|
|
bralid r15, do_notify_resume; /* Handle any signals */
|
|
addi r6, r0, 0; /* Arg 2: int in_syscall */
|
|
bri 1b
|
|
|
|
/* Finally, return to user state. */
|
|
no_intr_resched:
|
|
/* Disable interrupts, we are now committed to the state restore */
|
|
disable_irq
|
|
swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE);
|
|
VM_OFF;
|
|
tophys(r1,r1);
|
|
RESTORE_REGS
|
|
addik r1, r1, PT_SIZE /* MS: Clean up stack space. */
|
|
lwi r1, r1, PT_R1 - PT_SIZE;
|
|
bri 6f;
|
|
/* MS: Return to kernel state. */
|
|
2:
|
|
#ifdef CONFIG_PREEMPT
|
|
lwi r11, CURRENT_TASK, TS_THREAD_INFO;
|
|
/* MS: get preempt_count from thread info */
|
|
lwi r5, r11, TI_PREEMPT_COUNT;
|
|
bgti r5, restore;
|
|
|
|
lwi r5, r11, TI_FLAGS; /* get flags in thread info */
|
|
andi r5, r5, _TIF_NEED_RESCHED;
|
|
beqi r5, restore /* if zero jump over */
|
|
|
|
preempt:
|
|
/* interrupts are off that's why I am calling preempt_chedule_irq */
|
|
bralid r15, preempt_schedule_irq
|
|
nop
|
|
lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
|
|
lwi r5, r11, TI_FLAGS; /* get flags in thread info */
|
|
andi r5, r5, _TIF_NEED_RESCHED;
|
|
bnei r5, preempt /* if non zero jump to resched */
|
|
restore:
|
|
#endif
|
|
VM_OFF /* MS: turn off MMU */
|
|
tophys(r1,r1)
|
|
RESTORE_REGS
|
|
addik r1, r1, PT_SIZE /* MS: Clean up stack space. */
|
|
tovirt(r1,r1);
|
|
6:
|
|
IRQ_return: /* MS: Make global symbol for debugging */
|
|
rtid r14, 0
|
|
nop
|
|
|
|
/*
|
|
* Debug trap for KGDB. Enter to _debug_exception by brki r16, 0x18
|
|
* and call handling function with saved pt_regs
|
|
*/
|
|
C_ENTRY(_debug_exception):
|
|
/* BIP bit is set on entry, no interrupts can occur */
|
|
swi r1, r0, TOPHYS(PER_CPU(ENTRY_SP))
|
|
|
|
mfs r1, rmsr
|
|
nop
|
|
andi r1, r1, MSR_UMS
|
|
bnei r1, 1f
|
|
/* MS: Kernel-mode state save - kgdb */
|
|
lwi r1, r0, TOPHYS(PER_CPU(ENTRY_SP)); /* Reload kernel stack-ptr*/
|
|
|
|
/* BIP bit is set on entry, no interrupts can occur */
|
|
addik r1, r1, CONFIG_KERNEL_BASE_ADDR - CONFIG_KERNEL_START - PT_SIZE;
|
|
SAVE_REGS;
|
|
/* save all regs to pt_reg structure */
|
|
swi r0, r1, PT_R0; /* R0 must be saved too */
|
|
swi r14, r1, PT_R14 /* rewrite saved R14 value */
|
|
swi r16, r1, PT_PC; /* PC and r16 are the same */
|
|
/* save special purpose registers to pt_regs */
|
|
mfs r11, rear;
|
|
swi r11, r1, PT_EAR;
|
|
mfs r11, resr;
|
|
swi r11, r1, PT_ESR;
|
|
mfs r11, rfsr;
|
|
swi r11, r1, PT_FSR;
|
|
|
|
/* stack pointer is in physical address at it is decrease
|
|
* by PT_SIZE but we need to get correct R1 value */
|
|
addik r11, r1, CONFIG_KERNEL_START - CONFIG_KERNEL_BASE_ADDR + PT_SIZE;
|
|
swi r11, r1, PT_R1
|
|
/* MS: r31 - current pointer isn't changed */
|
|
tovirt(r1,r1)
|
|
#ifdef CONFIG_KGDB
|
|
addi r5, r1, 0 /* pass pt_reg address as the first arg */
|
|
addik r15, r0, dbtrap_call; /* return address */
|
|
rtbd r0, microblaze_kgdb_break
|
|
nop;
|
|
#endif
|
|
/* MS: Place handler for brki from kernel space if KGDB is OFF.
|
|
* It is very unlikely that another brki instruction is called. */
|
|
bri 0
|
|
|
|
/* MS: User-mode state save - gdb */
|
|
1: lwi r1, r0, TOPHYS(PER_CPU(CURRENT_SAVE)); /* get saved current */
|
|
tophys(r1,r1);
|
|
lwi r1, r1, TS_THREAD_INFO; /* get the thread info */
|
|
addik r1, r1, THREAD_SIZE; /* calculate kernel stack pointer */
|
|
tophys(r1,r1);
|
|
|
|
addik r1, r1, -PT_SIZE; /* Make room on the stack. */
|
|
SAVE_REGS;
|
|
swi r16, r1, PT_PC; /* Save LP */
|
|
swi r0, r1, PT_MODE; /* Was in user-mode. */
|
|
lwi r11, r0, TOPHYS(PER_CPU(ENTRY_SP));
|
|
swi r11, r1, PT_R1; /* Store user SP. */
|
|
lwi CURRENT_TASK, r0, TOPHYS(PER_CPU(CURRENT_SAVE));
|
|
tovirt(r1,r1)
|
|
set_vms;
|
|
addik r5, r1, 0;
|
|
addik r15, r0, dbtrap_call;
|
|
dbtrap_call: /* Return point for kernel/user entry + 8 because of rtsd r15, 8 */
|
|
rtbd r0, sw_exception
|
|
nop
|
|
|
|
/* MS: The first instruction for the second part of the gdb/kgdb */
|
|
set_bip; /* Ints masked for state restore */
|
|
lwi r11, r1, PT_MODE;
|
|
bnei r11, 2f;
|
|
/* MS: Return to user space - gdb */
|
|
1:
|
|
/* Get current task ptr into r11 */
|
|
lwi r11, CURRENT_TASK, TS_THREAD_INFO; /* get thread info */
|
|
lwi r19, r11, TI_FLAGS; /* get flags in thread info */
|
|
andi r11, r19, _TIF_NEED_RESCHED;
|
|
beqi r11, 5f;
|
|
|
|
/* Call the scheduler before returning from a syscall/trap. */
|
|
bralid r15, schedule; /* Call scheduler */
|
|
nop; /* delay slot */
|
|
bri 1b
|
|
|
|
/* Maybe handle a signal */
|
|
5: andi r11, r19, _TIF_SIGPENDING | _TIF_NOTIFY_RESUME;
|
|
beqi r11, 4f; /* Signals to handle, handle them */
|
|
|
|
addik r5, r1, 0; /* Arg 1: struct pt_regs *regs */
|
|
bralid r15, do_notify_resume; /* Handle any signals */
|
|
addi r6, r0, 0; /* Arg 2: int in_syscall */
|
|
bri 1b
|
|
|
|
/* Finally, return to user state. */
|
|
4: swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE); /* save current */
|
|
VM_OFF;
|
|
tophys(r1,r1);
|
|
/* MS: Restore all regs */
|
|
RESTORE_REGS
|
|
addik r1, r1, PT_SIZE /* Clean up stack space */
|
|
lwi r1, r1, PT_R1 - PT_SIZE; /* Restore user stack pointer */
|
|
DBTRAP_return_user: /* MS: Make global symbol for debugging */
|
|
rtbd r16, 0; /* MS: Instructions to return from a debug trap */
|
|
nop;
|
|
|
|
/* MS: Return to kernel state - kgdb */
|
|
2: VM_OFF;
|
|
tophys(r1,r1);
|
|
/* MS: Restore all regs */
|
|
RESTORE_REGS
|
|
lwi r14, r1, PT_R14;
|
|
lwi r16, r1, PT_PC;
|
|
addik r1, r1, PT_SIZE; /* MS: Clean up stack space */
|
|
tovirt(r1,r1);
|
|
DBTRAP_return_kernel: /* MS: Make global symbol for debugging */
|
|
rtbd r16, 0; /* MS: Instructions to return from a debug trap */
|
|
nop;
|
|
|
|
|
|
ENTRY(_switch_to)
|
|
/* prepare return value */
|
|
addk r3, r0, CURRENT_TASK
|
|
|
|
/* save registers in cpu_context */
|
|
/* use r11 and r12, volatile registers, as temp register */
|
|
/* give start of cpu_context for previous process */
|
|
addik r11, r5, TI_CPU_CONTEXT
|
|
swi r1, r11, CC_R1
|
|
swi r2, r11, CC_R2
|
|
/* skip volatile registers.
|
|
* they are saved on stack when we jumped to _switch_to() */
|
|
/* dedicated registers */
|
|
swi r13, r11, CC_R13
|
|
swi r14, r11, CC_R14
|
|
swi r15, r11, CC_R15
|
|
swi r16, r11, CC_R16
|
|
swi r17, r11, CC_R17
|
|
swi r18, r11, CC_R18
|
|
/* save non-volatile registers */
|
|
swi r19, r11, CC_R19
|
|
swi r20, r11, CC_R20
|
|
swi r21, r11, CC_R21
|
|
swi r22, r11, CC_R22
|
|
swi r23, r11, CC_R23
|
|
swi r24, r11, CC_R24
|
|
swi r25, r11, CC_R25
|
|
swi r26, r11, CC_R26
|
|
swi r27, r11, CC_R27
|
|
swi r28, r11, CC_R28
|
|
swi r29, r11, CC_R29
|
|
swi r30, r11, CC_R30
|
|
/* special purpose registers */
|
|
mfs r12, rmsr
|
|
swi r12, r11, CC_MSR
|
|
mfs r12, rear
|
|
swi r12, r11, CC_EAR
|
|
mfs r12, resr
|
|
swi r12, r11, CC_ESR
|
|
mfs r12, rfsr
|
|
swi r12, r11, CC_FSR
|
|
|
|
/* update r31, the current-give me pointer to task which will be next */
|
|
lwi CURRENT_TASK, r6, TI_TASK
|
|
/* stored it to current_save too */
|
|
swi CURRENT_TASK, r0, PER_CPU(CURRENT_SAVE)
|
|
|
|
/* get new process' cpu context and restore */
|
|
/* give me start where start context of next task */
|
|
addik r11, r6, TI_CPU_CONTEXT
|
|
|
|
/* non-volatile registers */
|
|
lwi r30, r11, CC_R30
|
|
lwi r29, r11, CC_R29
|
|
lwi r28, r11, CC_R28
|
|
lwi r27, r11, CC_R27
|
|
lwi r26, r11, CC_R26
|
|
lwi r25, r11, CC_R25
|
|
lwi r24, r11, CC_R24
|
|
lwi r23, r11, CC_R23
|
|
lwi r22, r11, CC_R22
|
|
lwi r21, r11, CC_R21
|
|
lwi r20, r11, CC_R20
|
|
lwi r19, r11, CC_R19
|
|
/* dedicated registers */
|
|
lwi r18, r11, CC_R18
|
|
lwi r17, r11, CC_R17
|
|
lwi r16, r11, CC_R16
|
|
lwi r15, r11, CC_R15
|
|
lwi r14, r11, CC_R14
|
|
lwi r13, r11, CC_R13
|
|
/* skip volatile registers */
|
|
lwi r2, r11, CC_R2
|
|
lwi r1, r11, CC_R1
|
|
|
|
/* special purpose registers */
|
|
lwi r12, r11, CC_FSR
|
|
mts rfsr, r12
|
|
lwi r12, r11, CC_MSR
|
|
mts rmsr, r12
|
|
|
|
rtsd r15, 8
|
|
nop
|
|
|
|
ENTRY(_reset)
|
|
brai 0; /* Jump to reset vector */
|
|
|
|
/* These are compiled and loaded into high memory, then
|
|
* copied into place in mach_early_setup */
|
|
.section .init.ivt, "ax"
|
|
#if CONFIG_MANUAL_RESET_VECTOR
|
|
.org 0x0
|
|
brai CONFIG_MANUAL_RESET_VECTOR
|
|
#endif
|
|
.org 0x8
|
|
brai TOPHYS(_user_exception); /* syscall handler */
|
|
.org 0x10
|
|
brai TOPHYS(_interrupt); /* Interrupt handler */
|
|
.org 0x18
|
|
brai TOPHYS(_debug_exception); /* debug trap handler */
|
|
.org 0x20
|
|
brai TOPHYS(_hw_exception_handler); /* HW exception handler */
|
|
|
|
.section .rodata,"a"
|
|
#include "syscall_table.S"
|
|
|
|
syscall_table_size=(.-sys_call_table)
|
|
|
|
type_SYSCALL:
|
|
.ascii "SYSCALL\0"
|
|
type_IRQ:
|
|
.ascii "IRQ\0"
|
|
type_IRQ_PREEMPT:
|
|
.ascii "IRQ (PREEMPTED)\0"
|
|
type_SYSCALL_PREEMPT:
|
|
.ascii " SYSCALL (PREEMPTED)\0"
|
|
|
|
/*
|
|
* Trap decoding for stack unwinder
|
|
* Tuples are (start addr, end addr, string)
|
|
* If return address lies on [start addr, end addr],
|
|
* unwinder displays 'string'
|
|
*/
|
|
|
|
.align 4
|
|
.global microblaze_trap_handlers
|
|
microblaze_trap_handlers:
|
|
/* Exact matches come first */
|
|
.word ret_from_trap; .word ret_from_trap ; .word type_SYSCALL
|
|
.word ret_from_irq ; .word ret_from_irq ; .word type_IRQ
|
|
/* Fuzzy matches go here */
|
|
.word ret_from_irq ; .word no_intr_resched ; .word type_IRQ_PREEMPT
|
|
.word ret_from_trap; .word TRAP_return ; .word type_SYSCALL_PREEMPT
|
|
/* End of table */
|
|
.word 0 ; .word 0 ; .word 0
|