1193 строки
28 KiB
ArmAsm
1193 строки
28 KiB
ArmAsm
/*
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* linux/arch/arm/kernel/entry-armv.S
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*
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* Copyright (C) 1996,1997,1998 Russell King.
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* ARM700 fix by Matthew Godbolt (linux-user@willothewisp.demon.co.uk)
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* nommu support by Hyok S. Choi (hyok.choi@samsung.com)
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* Low-level vector interface routines
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*
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* Note: there is a StrongARM bug in the STMIA rn, {regs}^ instruction
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* that causes it to save wrong values... Be aware!
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*/
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#include <asm/assembler.h>
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#include <asm/memory.h>
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#include <asm/glue-df.h>
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#include <asm/glue-pf.h>
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#include <asm/vfpmacros.h>
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#ifndef CONFIG_MULTI_IRQ_HANDLER
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#include <mach/entry-macro.S>
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#endif
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#include <asm/thread_notify.h>
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#include <asm/unwind.h>
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#include <asm/unistd.h>
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#include <asm/tls.h>
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#include <asm/system_info.h>
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#include "entry-header.S"
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#include <asm/entry-macro-multi.S>
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/*
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* Interrupt handling.
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*/
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.macro irq_handler
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#ifdef CONFIG_MULTI_IRQ_HANDLER
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ldr r1, =handle_arch_irq
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mov r0, sp
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adr lr, BSYM(9997f)
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ldr pc, [r1]
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#else
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arch_irq_handler_default
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#endif
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9997:
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.endm
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.macro pabt_helper
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@ PABORT handler takes pt_regs in r2, fault address in r4 and psr in r5
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#ifdef MULTI_PABORT
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ldr ip, .LCprocfns
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mov lr, pc
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ldr pc, [ip, #PROCESSOR_PABT_FUNC]
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#else
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bl CPU_PABORT_HANDLER
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#endif
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.endm
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.macro dabt_helper
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@
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@ Call the processor-specific abort handler:
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@
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@ r2 - pt_regs
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@ r4 - aborted context pc
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@ r5 - aborted context psr
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@
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@ The abort handler must return the aborted address in r0, and
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@ the fault status register in r1. r9 must be preserved.
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@
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#ifdef MULTI_DABORT
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ldr ip, .LCprocfns
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mov lr, pc
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ldr pc, [ip, #PROCESSOR_DABT_FUNC]
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#else
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bl CPU_DABORT_HANDLER
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#endif
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.endm
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#ifdef CONFIG_KPROBES
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.section .kprobes.text,"ax",%progbits
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#else
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.text
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#endif
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/*
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* Invalid mode handlers
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*/
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.macro inv_entry, reason
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sub sp, sp, #S_FRAME_SIZE
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ARM( stmib sp, {r1 - lr} )
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THUMB( stmia sp, {r0 - r12} )
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THUMB( str sp, [sp, #S_SP] )
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THUMB( str lr, [sp, #S_LR] )
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mov r1, #\reason
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.endm
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__pabt_invalid:
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inv_entry BAD_PREFETCH
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b common_invalid
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ENDPROC(__pabt_invalid)
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__dabt_invalid:
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inv_entry BAD_DATA
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b common_invalid
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ENDPROC(__dabt_invalid)
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__irq_invalid:
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inv_entry BAD_IRQ
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b common_invalid
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ENDPROC(__irq_invalid)
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__und_invalid:
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inv_entry BAD_UNDEFINSTR
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@
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@ XXX fall through to common_invalid
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@
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@
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@ common_invalid - generic code for failed exception (re-entrant version of handlers)
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@
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common_invalid:
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zero_fp
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ldmia r0, {r4 - r6}
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add r0, sp, #S_PC @ here for interlock avoidance
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mov r7, #-1 @ "" "" "" ""
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str r4, [sp] @ save preserved r0
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stmia r0, {r5 - r7} @ lr_<exception>,
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@ cpsr_<exception>, "old_r0"
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mov r0, sp
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b bad_mode
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ENDPROC(__und_invalid)
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/*
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* SVC mode handlers
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*/
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#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5)
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#define SPFIX(code...) code
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#else
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#define SPFIX(code...)
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#endif
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.macro svc_entry, stack_hole=0
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UNWIND(.fnstart )
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UNWIND(.save {r0 - pc} )
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sub sp, sp, #(S_FRAME_SIZE + \stack_hole - 4)
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#ifdef CONFIG_THUMB2_KERNEL
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SPFIX( str r0, [sp] ) @ temporarily saved
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SPFIX( mov r0, sp )
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SPFIX( tst r0, #4 ) @ test original stack alignment
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SPFIX( ldr r0, [sp] ) @ restored
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#else
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SPFIX( tst sp, #4 )
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#endif
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SPFIX( subeq sp, sp, #4 )
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stmia sp, {r1 - r12}
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ldmia r0, {r3 - r5}
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add r7, sp, #S_SP - 4 @ here for interlock avoidance
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mov r6, #-1 @ "" "" "" ""
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add r2, sp, #(S_FRAME_SIZE + \stack_hole - 4)
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SPFIX( addeq r2, r2, #4 )
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str r3, [sp, #-4]! @ save the "real" r0 copied
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@ from the exception stack
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mov r3, lr
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@
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@ We are now ready to fill in the remaining blanks on the stack:
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@
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@ r2 - sp_svc
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@ r3 - lr_svc
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@ r4 - lr_<exception>, already fixed up for correct return/restart
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@ r5 - spsr_<exception>
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@ r6 - orig_r0 (see pt_regs definition in ptrace.h)
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@
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stmia r7, {r2 - r6}
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#ifdef CONFIG_TRACE_IRQFLAGS
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bl trace_hardirqs_off
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#endif
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.endm
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.align 5
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__dabt_svc:
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svc_entry
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mov r2, sp
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dabt_helper
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@
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@ IRQs off again before pulling preserved data off the stack
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@
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disable_irq_notrace
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#ifdef CONFIG_TRACE_IRQFLAGS
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tst r5, #PSR_I_BIT
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bleq trace_hardirqs_on
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tst r5, #PSR_I_BIT
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blne trace_hardirqs_off
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#endif
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svc_exit r5 @ return from exception
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UNWIND(.fnend )
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ENDPROC(__dabt_svc)
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.align 5
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__irq_svc:
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svc_entry
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irq_handler
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#ifdef CONFIG_PREEMPT
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get_thread_info tsk
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ldr r8, [tsk, #TI_PREEMPT] @ get preempt count
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ldr r0, [tsk, #TI_FLAGS] @ get flags
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teq r8, #0 @ if preempt count != 0
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movne r0, #0 @ force flags to 0
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tst r0, #_TIF_NEED_RESCHED
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blne svc_preempt
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#endif
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#ifdef CONFIG_TRACE_IRQFLAGS
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@ The parent context IRQs must have been enabled to get here in
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@ the first place, so there's no point checking the PSR I bit.
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bl trace_hardirqs_on
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#endif
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svc_exit r5 @ return from exception
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UNWIND(.fnend )
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ENDPROC(__irq_svc)
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.ltorg
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#ifdef CONFIG_PREEMPT
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svc_preempt:
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mov r8, lr
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1: bl preempt_schedule_irq @ irq en/disable is done inside
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ldr r0, [tsk, #TI_FLAGS] @ get new tasks TI_FLAGS
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tst r0, #_TIF_NEED_RESCHED
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moveq pc, r8 @ go again
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b 1b
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#endif
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__und_fault:
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@ Correct the PC such that it is pointing at the instruction
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@ which caused the fault. If the faulting instruction was ARM
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@ the PC will be pointing at the next instruction, and have to
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@ subtract 4. Otherwise, it is Thumb, and the PC will be
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@ pointing at the second half of the Thumb instruction. We
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@ have to subtract 2.
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ldr r2, [r0, #S_PC]
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sub r2, r2, r1
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str r2, [r0, #S_PC]
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b do_undefinstr
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ENDPROC(__und_fault)
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.align 5
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__und_svc:
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#ifdef CONFIG_KPROBES
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@ If a kprobe is about to simulate a "stmdb sp..." instruction,
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@ it obviously needs free stack space which then will belong to
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@ the saved context.
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svc_entry 64
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#else
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svc_entry
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#endif
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@
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@ call emulation code, which returns using r9 if it has emulated
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@ the instruction, or the more conventional lr if we are to treat
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@ this as a real undefined instruction
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@
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@ r0 - instruction
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@
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#ifndef CONFIG_THUMB2_KERNEL
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ldr r0, [r4, #-4]
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#else
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mov r1, #2
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ldrh r0, [r4, #-2] @ Thumb instruction at LR - 2
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cmp r0, #0xe800 @ 32-bit instruction if xx >= 0
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blo __und_svc_fault
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ldrh r9, [r4] @ bottom 16 bits
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add r4, r4, #2
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str r4, [sp, #S_PC]
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orr r0, r9, r0, lsl #16
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#endif
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adr r9, BSYM(__und_svc_finish)
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mov r2, r4
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bl call_fpe
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mov r1, #4 @ PC correction to apply
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__und_svc_fault:
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mov r0, sp @ struct pt_regs *regs
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bl __und_fault
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@
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@ IRQs off again before pulling preserved data off the stack
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@
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__und_svc_finish:
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disable_irq_notrace
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@
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@ restore SPSR and restart the instruction
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@
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ldr r5, [sp, #S_PSR] @ Get SVC cpsr
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#ifdef CONFIG_TRACE_IRQFLAGS
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tst r5, #PSR_I_BIT
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bleq trace_hardirqs_on
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tst r5, #PSR_I_BIT
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blne trace_hardirqs_off
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#endif
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svc_exit r5 @ return from exception
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UNWIND(.fnend )
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ENDPROC(__und_svc)
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.align 5
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__pabt_svc:
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svc_entry
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mov r2, sp @ regs
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pabt_helper
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@
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@ IRQs off again before pulling preserved data off the stack
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@
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disable_irq_notrace
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#ifdef CONFIG_TRACE_IRQFLAGS
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tst r5, #PSR_I_BIT
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bleq trace_hardirqs_on
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tst r5, #PSR_I_BIT
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blne trace_hardirqs_off
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#endif
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svc_exit r5 @ return from exception
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UNWIND(.fnend )
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ENDPROC(__pabt_svc)
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.align 5
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.LCcralign:
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.word cr_alignment
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#ifdef MULTI_DABORT
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.LCprocfns:
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.word processor
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#endif
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.LCfp:
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.word fp_enter
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/*
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* User mode handlers
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*
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* EABI note: sp_svc is always 64-bit aligned here, so should S_FRAME_SIZE
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*/
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#if defined(CONFIG_AEABI) && (__LINUX_ARM_ARCH__ >= 5) && (S_FRAME_SIZE & 7)
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#error "sizeof(struct pt_regs) must be a multiple of 8"
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#endif
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.macro usr_entry
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UNWIND(.fnstart )
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UNWIND(.cantunwind ) @ don't unwind the user space
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sub sp, sp, #S_FRAME_SIZE
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ARM( stmib sp, {r1 - r12} )
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THUMB( stmia sp, {r0 - r12} )
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ldmia r0, {r3 - r5}
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add r0, sp, #S_PC @ here for interlock avoidance
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mov r6, #-1 @ "" "" "" ""
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str r3, [sp] @ save the "real" r0 copied
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@ from the exception stack
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@
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@ We are now ready to fill in the remaining blanks on the stack:
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@
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@ r4 - lr_<exception>, already fixed up for correct return/restart
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@ r5 - spsr_<exception>
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@ r6 - orig_r0 (see pt_regs definition in ptrace.h)
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@
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@ Also, separately save sp_usr and lr_usr
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@
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stmia r0, {r4 - r6}
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ARM( stmdb r0, {sp, lr}^ )
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THUMB( store_user_sp_lr r0, r1, S_SP - S_PC )
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@
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@ Enable the alignment trap while in kernel mode
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@
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alignment_trap r0
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@
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@ Clear FP to mark the first stack frame
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@
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zero_fp
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#ifdef CONFIG_IRQSOFF_TRACER
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bl trace_hardirqs_off
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#endif
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.endm
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.macro kuser_cmpxchg_check
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#if !defined(CONFIG_CPU_32v6K) && !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
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#ifndef CONFIG_MMU
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#warning "NPTL on non MMU needs fixing"
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#else
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@ Make sure our user space atomic helper is restarted
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@ if it was interrupted in a critical region. Here we
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@ perform a quick test inline since it should be false
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@ 99.9999% of the time. The rest is done out of line.
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cmp r4, #TASK_SIZE
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blhs kuser_cmpxchg64_fixup
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#endif
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#endif
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.endm
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.align 5
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__dabt_usr:
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usr_entry
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kuser_cmpxchg_check
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mov r2, sp
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dabt_helper
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b ret_from_exception
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UNWIND(.fnend )
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ENDPROC(__dabt_usr)
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.align 5
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__irq_usr:
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usr_entry
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kuser_cmpxchg_check
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irq_handler
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get_thread_info tsk
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mov why, #0
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b ret_to_user_from_irq
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UNWIND(.fnend )
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ENDPROC(__irq_usr)
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.ltorg
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.align 5
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__und_usr:
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usr_entry
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mov r2, r4
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mov r3, r5
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@ r2 = regs->ARM_pc, which is either 2 or 4 bytes ahead of the
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@ faulting instruction depending on Thumb mode.
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@ r3 = regs->ARM_cpsr
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@
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@ The emulation code returns using r9 if it has emulated the
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@ instruction, or the more conventional lr if we are to treat
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@ this as a real undefined instruction
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@
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adr r9, BSYM(ret_from_exception)
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tst r3, #PSR_T_BIT @ Thumb mode?
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bne __und_usr_thumb
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sub r4, r2, #4 @ ARM instr at LR - 4
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1: ldrt r0, [r4]
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#ifdef CONFIG_CPU_ENDIAN_BE8
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rev r0, r0 @ little endian instruction
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#endif
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@ r0 = 32-bit ARM instruction which caused the exception
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@ r2 = PC value for the following instruction (:= regs->ARM_pc)
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@ r4 = PC value for the faulting instruction
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@ lr = 32-bit undefined instruction function
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adr lr, BSYM(__und_usr_fault_32)
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b call_fpe
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__und_usr_thumb:
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@ Thumb instruction
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sub r4, r2, #2 @ First half of thumb instr at LR - 2
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#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
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/*
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* Thumb-2 instruction handling. Note that because pre-v6 and >= v6 platforms
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* can never be supported in a single kernel, this code is not applicable at
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* all when __LINUX_ARM_ARCH__ < 6. This allows simplifying assumptions to be
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* made about .arch directives.
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*/
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#if __LINUX_ARM_ARCH__ < 7
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/* If the target CPU may not be Thumb-2-capable, a run-time check is needed: */
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#define NEED_CPU_ARCHITECTURE
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ldr r5, .LCcpu_architecture
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ldr r5, [r5]
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cmp r5, #CPU_ARCH_ARMv7
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blo __und_usr_fault_16 @ 16bit undefined instruction
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/*
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* The following code won't get run unless the running CPU really is v7, so
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* coding round the lack of ldrht on older arches is pointless. Temporarily
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* override the assembler target arch with the minimum required instead:
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*/
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.arch armv6t2
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#endif
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2: ldrht r5, [r4]
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cmp r5, #0xe800 @ 32bit instruction if xx != 0
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blo __und_usr_fault_16 @ 16bit undefined instruction
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3: ldrht r0, [r2]
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add r2, r2, #2 @ r2 is PC + 2, make it PC + 4
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str r2, [sp, #S_PC] @ it's a 2x16bit instr, update
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orr r0, r0, r5, lsl #16
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adr lr, BSYM(__und_usr_fault_32)
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@ r0 = the two 16-bit Thumb instructions which caused the exception
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@ r2 = PC value for the following Thumb instruction (:= regs->ARM_pc)
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@ r4 = PC value for the first 16-bit Thumb instruction
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@ lr = 32bit undefined instruction function
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#if __LINUX_ARM_ARCH__ < 7
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/* If the target arch was overridden, change it back: */
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#ifdef CONFIG_CPU_32v6K
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.arch armv6k
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#else
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.arch armv6
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#endif
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#endif /* __LINUX_ARM_ARCH__ < 7 */
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#else /* !(CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7) */
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b __und_usr_fault_16
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#endif
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UNWIND(.fnend)
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ENDPROC(__und_usr)
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/*
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* The out of line fixup for the ldrt instructions above.
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*/
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.pushsection .fixup, "ax"
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|
.align 2
|
|
4: mov pc, r9
|
|
.popsection
|
|
.pushsection __ex_table,"a"
|
|
.long 1b, 4b
|
|
#if CONFIG_ARM_THUMB && __LINUX_ARM_ARCH__ >= 6 && CONFIG_CPU_V7
|
|
.long 2b, 4b
|
|
.long 3b, 4b
|
|
#endif
|
|
.popsection
|
|
|
|
/*
|
|
* Check whether the instruction is a co-processor instruction.
|
|
* If yes, we need to call the relevant co-processor handler.
|
|
*
|
|
* Note that we don't do a full check here for the co-processor
|
|
* instructions; all instructions with bit 27 set are well
|
|
* defined. The only instructions that should fault are the
|
|
* co-processor instructions. However, we have to watch out
|
|
* for the ARM6/ARM7 SWI bug.
|
|
*
|
|
* NEON is a special case that has to be handled here. Not all
|
|
* NEON instructions are co-processor instructions, so we have
|
|
* to make a special case of checking for them. Plus, there's
|
|
* five groups of them, so we have a table of mask/opcode pairs
|
|
* to check against, and if any match then we branch off into the
|
|
* NEON handler code.
|
|
*
|
|
* Emulators may wish to make use of the following registers:
|
|
* r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
|
|
* r2 = PC value to resume execution after successful emulation
|
|
* r9 = normal "successful" return address
|
|
* r10 = this threads thread_info structure
|
|
* lr = unrecognised instruction return address
|
|
* IRQs disabled, FIQs enabled.
|
|
*/
|
|
@
|
|
@ Fall-through from Thumb-2 __und_usr
|
|
@
|
|
#ifdef CONFIG_NEON
|
|
adr r6, .LCneon_thumb_opcodes
|
|
b 2f
|
|
#endif
|
|
call_fpe:
|
|
#ifdef CONFIG_NEON
|
|
adr r6, .LCneon_arm_opcodes
|
|
2:
|
|
ldr r7, [r6], #4 @ mask value
|
|
cmp r7, #0 @ end mask?
|
|
beq 1f
|
|
and r8, r0, r7
|
|
ldr r7, [r6], #4 @ opcode bits matching in mask
|
|
cmp r8, r7 @ NEON instruction?
|
|
bne 2b
|
|
get_thread_info r10
|
|
mov r7, #1
|
|
strb r7, [r10, #TI_USED_CP + 10] @ mark CP#10 as used
|
|
strb r7, [r10, #TI_USED_CP + 11] @ mark CP#11 as used
|
|
b do_vfp @ let VFP handler handle this
|
|
1:
|
|
#endif
|
|
tst r0, #0x08000000 @ only CDP/CPRT/LDC/STC have bit 27
|
|
tstne r0, #0x04000000 @ bit 26 set on both ARM and Thumb-2
|
|
moveq pc, lr
|
|
get_thread_info r10 @ get current thread
|
|
and r8, r0, #0x00000f00 @ mask out CP number
|
|
THUMB( lsr r8, r8, #8 )
|
|
mov r7, #1
|
|
add r6, r10, #TI_USED_CP
|
|
ARM( strb r7, [r6, r8, lsr #8] ) @ set appropriate used_cp[]
|
|
THUMB( strb r7, [r6, r8] ) @ set appropriate used_cp[]
|
|
#ifdef CONFIG_IWMMXT
|
|
@ Test if we need to give access to iWMMXt coprocessors
|
|
ldr r5, [r10, #TI_FLAGS]
|
|
rsbs r7, r8, #(1 << 8) @ CP 0 or 1 only
|
|
movcss r7, r5, lsr #(TIF_USING_IWMMXT + 1)
|
|
bcs iwmmxt_task_enable
|
|
#endif
|
|
ARM( add pc, pc, r8, lsr #6 )
|
|
THUMB( lsl r8, r8, #2 )
|
|
THUMB( add pc, r8 )
|
|
nop
|
|
|
|
movw_pc lr @ CP#0
|
|
W(b) do_fpe @ CP#1 (FPE)
|
|
W(b) do_fpe @ CP#2 (FPE)
|
|
movw_pc lr @ CP#3
|
|
#ifdef CONFIG_CRUNCH
|
|
b crunch_task_enable @ CP#4 (MaverickCrunch)
|
|
b crunch_task_enable @ CP#5 (MaverickCrunch)
|
|
b crunch_task_enable @ CP#6 (MaverickCrunch)
|
|
#else
|
|
movw_pc lr @ CP#4
|
|
movw_pc lr @ CP#5
|
|
movw_pc lr @ CP#6
|
|
#endif
|
|
movw_pc lr @ CP#7
|
|
movw_pc lr @ CP#8
|
|
movw_pc lr @ CP#9
|
|
#ifdef CONFIG_VFP
|
|
W(b) do_vfp @ CP#10 (VFP)
|
|
W(b) do_vfp @ CP#11 (VFP)
|
|
#else
|
|
movw_pc lr @ CP#10 (VFP)
|
|
movw_pc lr @ CP#11 (VFP)
|
|
#endif
|
|
movw_pc lr @ CP#12
|
|
movw_pc lr @ CP#13
|
|
movw_pc lr @ CP#14 (Debug)
|
|
movw_pc lr @ CP#15 (Control)
|
|
|
|
#ifdef NEED_CPU_ARCHITECTURE
|
|
.align 2
|
|
.LCcpu_architecture:
|
|
.word __cpu_architecture
|
|
#endif
|
|
|
|
#ifdef CONFIG_NEON
|
|
.align 6
|
|
|
|
.LCneon_arm_opcodes:
|
|
.word 0xfe000000 @ mask
|
|
.word 0xf2000000 @ opcode
|
|
|
|
.word 0xff100000 @ mask
|
|
.word 0xf4000000 @ opcode
|
|
|
|
.word 0x00000000 @ mask
|
|
.word 0x00000000 @ opcode
|
|
|
|
.LCneon_thumb_opcodes:
|
|
.word 0xef000000 @ mask
|
|
.word 0xef000000 @ opcode
|
|
|
|
.word 0xff100000 @ mask
|
|
.word 0xf9000000 @ opcode
|
|
|
|
.word 0x00000000 @ mask
|
|
.word 0x00000000 @ opcode
|
|
#endif
|
|
|
|
do_fpe:
|
|
enable_irq
|
|
ldr r4, .LCfp
|
|
add r10, r10, #TI_FPSTATE @ r10 = workspace
|
|
ldr pc, [r4] @ Call FP module USR entry point
|
|
|
|
/*
|
|
* The FP module is called with these registers set:
|
|
* r0 = instruction
|
|
* r2 = PC+4
|
|
* r9 = normal "successful" return address
|
|
* r10 = FP workspace
|
|
* lr = unrecognised FP instruction return address
|
|
*/
|
|
|
|
.pushsection .data
|
|
ENTRY(fp_enter)
|
|
.word no_fp
|
|
.popsection
|
|
|
|
ENTRY(no_fp)
|
|
mov pc, lr
|
|
ENDPROC(no_fp)
|
|
|
|
__und_usr_fault_32:
|
|
mov r1, #4
|
|
b 1f
|
|
__und_usr_fault_16:
|
|
mov r1, #2
|
|
1: enable_irq
|
|
mov r0, sp
|
|
adr lr, BSYM(ret_from_exception)
|
|
b __und_fault
|
|
ENDPROC(__und_usr_fault_32)
|
|
ENDPROC(__und_usr_fault_16)
|
|
|
|
.align 5
|
|
__pabt_usr:
|
|
usr_entry
|
|
mov r2, sp @ regs
|
|
pabt_helper
|
|
UNWIND(.fnend )
|
|
/* fall through */
|
|
/*
|
|
* This is the return code to user mode for abort handlers
|
|
*/
|
|
ENTRY(ret_from_exception)
|
|
UNWIND(.fnstart )
|
|
UNWIND(.cantunwind )
|
|
get_thread_info tsk
|
|
mov why, #0
|
|
b ret_to_user
|
|
UNWIND(.fnend )
|
|
ENDPROC(__pabt_usr)
|
|
ENDPROC(ret_from_exception)
|
|
|
|
/*
|
|
* Register switch for ARMv3 and ARMv4 processors
|
|
* r0 = previous task_struct, r1 = previous thread_info, r2 = next thread_info
|
|
* previous and next are guaranteed not to be the same.
|
|
*/
|
|
ENTRY(__switch_to)
|
|
UNWIND(.fnstart )
|
|
UNWIND(.cantunwind )
|
|
add ip, r1, #TI_CPU_SAVE
|
|
ldr r3, [r2, #TI_TP_VALUE]
|
|
ARM( stmia ip!, {r4 - sl, fp, sp, lr} ) @ Store most regs on stack
|
|
THUMB( stmia ip!, {r4 - sl, fp} ) @ Store most regs on stack
|
|
THUMB( str sp, [ip], #4 )
|
|
THUMB( str lr, [ip], #4 )
|
|
#ifdef CONFIG_CPU_USE_DOMAINS
|
|
ldr r6, [r2, #TI_CPU_DOMAIN]
|
|
#endif
|
|
set_tls r3, r4, r5
|
|
#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
|
|
ldr r7, [r2, #TI_TASK]
|
|
ldr r8, =__stack_chk_guard
|
|
ldr r7, [r7, #TSK_STACK_CANARY]
|
|
#endif
|
|
#ifdef CONFIG_CPU_USE_DOMAINS
|
|
mcr p15, 0, r6, c3, c0, 0 @ Set domain register
|
|
#endif
|
|
mov r5, r0
|
|
add r4, r2, #TI_CPU_SAVE
|
|
ldr r0, =thread_notify_head
|
|
mov r1, #THREAD_NOTIFY_SWITCH
|
|
bl atomic_notifier_call_chain
|
|
#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
|
|
str r7, [r8]
|
|
#endif
|
|
THUMB( mov ip, r4 )
|
|
mov r0, r5
|
|
ARM( ldmia r4, {r4 - sl, fp, sp, pc} ) @ Load all regs saved previously
|
|
THUMB( ldmia ip!, {r4 - sl, fp} ) @ Load all regs saved previously
|
|
THUMB( ldr sp, [ip], #4 )
|
|
THUMB( ldr pc, [ip] )
|
|
UNWIND(.fnend )
|
|
ENDPROC(__switch_to)
|
|
|
|
__INIT
|
|
|
|
/*
|
|
* User helpers.
|
|
*
|
|
* Each segment is 32-byte aligned and will be moved to the top of the high
|
|
* vector page. New segments (if ever needed) must be added in front of
|
|
* existing ones. This mechanism should be used only for things that are
|
|
* really small and justified, and not be abused freely.
|
|
*
|
|
* See Documentation/arm/kernel_user_helpers.txt for formal definitions.
|
|
*/
|
|
THUMB( .arm )
|
|
|
|
.macro usr_ret, reg
|
|
#ifdef CONFIG_ARM_THUMB
|
|
bx \reg
|
|
#else
|
|
mov pc, \reg
|
|
#endif
|
|
.endm
|
|
|
|
.align 5
|
|
.globl __kuser_helper_start
|
|
__kuser_helper_start:
|
|
|
|
/*
|
|
* Due to the length of some sequences, __kuser_cmpxchg64 spans 2 regular
|
|
* kuser "slots", therefore 0xffff0f80 is not used as a valid entry point.
|
|
*/
|
|
|
|
__kuser_cmpxchg64: @ 0xffff0f60
|
|
|
|
#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
|
|
|
|
/*
|
|
* Poor you. No fast solution possible...
|
|
* The kernel itself must perform the operation.
|
|
* A special ghost syscall is used for that (see traps.c).
|
|
*/
|
|
stmfd sp!, {r7, lr}
|
|
ldr r7, 1f @ it's 20 bits
|
|
swi __ARM_NR_cmpxchg64
|
|
ldmfd sp!, {r7, pc}
|
|
1: .word __ARM_NR_cmpxchg64
|
|
|
|
#elif defined(CONFIG_CPU_32v6K)
|
|
|
|
stmfd sp!, {r4, r5, r6, r7}
|
|
ldrd r4, r5, [r0] @ load old val
|
|
ldrd r6, r7, [r1] @ load new val
|
|
smp_dmb arm
|
|
1: ldrexd r0, r1, [r2] @ load current val
|
|
eors r3, r0, r4 @ compare with oldval (1)
|
|
eoreqs r3, r1, r5 @ compare with oldval (2)
|
|
strexdeq r3, r6, r7, [r2] @ store newval if eq
|
|
teqeq r3, #1 @ success?
|
|
beq 1b @ if no then retry
|
|
smp_dmb arm
|
|
rsbs r0, r3, #0 @ set returned val and C flag
|
|
ldmfd sp!, {r4, r5, r6, r7}
|
|
usr_ret lr
|
|
|
|
#elif !defined(CONFIG_SMP)
|
|
|
|
#ifdef CONFIG_MMU
|
|
|
|
/*
|
|
* The only thing that can break atomicity in this cmpxchg64
|
|
* implementation is either an IRQ or a data abort exception
|
|
* causing another process/thread to be scheduled in the middle of
|
|
* the critical sequence. The same strategy as for cmpxchg is used.
|
|
*/
|
|
stmfd sp!, {r4, r5, r6, lr}
|
|
ldmia r0, {r4, r5} @ load old val
|
|
ldmia r1, {r6, lr} @ load new val
|
|
1: ldmia r2, {r0, r1} @ load current val
|
|
eors r3, r0, r4 @ compare with oldval (1)
|
|
eoreqs r3, r1, r5 @ compare with oldval (2)
|
|
2: stmeqia r2, {r6, lr} @ store newval if eq
|
|
rsbs r0, r3, #0 @ set return val and C flag
|
|
ldmfd sp!, {r4, r5, r6, pc}
|
|
|
|
.text
|
|
kuser_cmpxchg64_fixup:
|
|
@ Called from kuser_cmpxchg_fixup.
|
|
@ r4 = address of interrupted insn (must be preserved).
|
|
@ sp = saved regs. r7 and r8 are clobbered.
|
|
@ 1b = first critical insn, 2b = last critical insn.
|
|
@ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
|
|
mov r7, #0xffff0fff
|
|
sub r7, r7, #(0xffff0fff - (0xffff0f60 + (1b - __kuser_cmpxchg64)))
|
|
subs r8, r4, r7
|
|
rsbcss r8, r8, #(2b - 1b)
|
|
strcs r7, [sp, #S_PC]
|
|
#if __LINUX_ARM_ARCH__ < 6
|
|
bcc kuser_cmpxchg32_fixup
|
|
#endif
|
|
mov pc, lr
|
|
.previous
|
|
|
|
#else
|
|
#warning "NPTL on non MMU needs fixing"
|
|
mov r0, #-1
|
|
adds r0, r0, #0
|
|
usr_ret lr
|
|
#endif
|
|
|
|
#else
|
|
#error "incoherent kernel configuration"
|
|
#endif
|
|
|
|
/* pad to next slot */
|
|
.rept (16 - (. - __kuser_cmpxchg64)/4)
|
|
.word 0
|
|
.endr
|
|
|
|
.align 5
|
|
|
|
__kuser_memory_barrier: @ 0xffff0fa0
|
|
smp_dmb arm
|
|
usr_ret lr
|
|
|
|
.align 5
|
|
|
|
__kuser_cmpxchg: @ 0xffff0fc0
|
|
|
|
#if defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
|
|
|
|
/*
|
|
* Poor you. No fast solution possible...
|
|
* The kernel itself must perform the operation.
|
|
* A special ghost syscall is used for that (see traps.c).
|
|
*/
|
|
stmfd sp!, {r7, lr}
|
|
ldr r7, 1f @ it's 20 bits
|
|
swi __ARM_NR_cmpxchg
|
|
ldmfd sp!, {r7, pc}
|
|
1: .word __ARM_NR_cmpxchg
|
|
|
|
#elif __LINUX_ARM_ARCH__ < 6
|
|
|
|
#ifdef CONFIG_MMU
|
|
|
|
/*
|
|
* The only thing that can break atomicity in this cmpxchg
|
|
* implementation is either an IRQ or a data abort exception
|
|
* causing another process/thread to be scheduled in the middle
|
|
* of the critical sequence. To prevent this, code is added to
|
|
* the IRQ and data abort exception handlers to set the pc back
|
|
* to the beginning of the critical section if it is found to be
|
|
* within that critical section (see kuser_cmpxchg_fixup).
|
|
*/
|
|
1: ldr r3, [r2] @ load current val
|
|
subs r3, r3, r0 @ compare with oldval
|
|
2: streq r1, [r2] @ store newval if eq
|
|
rsbs r0, r3, #0 @ set return val and C flag
|
|
usr_ret lr
|
|
|
|
.text
|
|
kuser_cmpxchg32_fixup:
|
|
@ Called from kuser_cmpxchg_check macro.
|
|
@ r4 = address of interrupted insn (must be preserved).
|
|
@ sp = saved regs. r7 and r8 are clobbered.
|
|
@ 1b = first critical insn, 2b = last critical insn.
|
|
@ If r4 >= 1b and r4 <= 2b then saved pc_usr is set to 1b.
|
|
mov r7, #0xffff0fff
|
|
sub r7, r7, #(0xffff0fff - (0xffff0fc0 + (1b - __kuser_cmpxchg)))
|
|
subs r8, r4, r7
|
|
rsbcss r8, r8, #(2b - 1b)
|
|
strcs r7, [sp, #S_PC]
|
|
mov pc, lr
|
|
.previous
|
|
|
|
#else
|
|
#warning "NPTL on non MMU needs fixing"
|
|
mov r0, #-1
|
|
adds r0, r0, #0
|
|
usr_ret lr
|
|
#endif
|
|
|
|
#else
|
|
|
|
smp_dmb arm
|
|
1: ldrex r3, [r2]
|
|
subs r3, r3, r0
|
|
strexeq r3, r1, [r2]
|
|
teqeq r3, #1
|
|
beq 1b
|
|
rsbs r0, r3, #0
|
|
/* beware -- each __kuser slot must be 8 instructions max */
|
|
ALT_SMP(b __kuser_memory_barrier)
|
|
ALT_UP(usr_ret lr)
|
|
|
|
#endif
|
|
|
|
.align 5
|
|
|
|
__kuser_get_tls: @ 0xffff0fe0
|
|
ldr r0, [pc, #(16 - 8)] @ read TLS, set in kuser_get_tls_init
|
|
usr_ret lr
|
|
mrc p15, 0, r0, c13, c0, 3 @ 0xffff0fe8 hardware TLS code
|
|
.rep 4
|
|
.word 0 @ 0xffff0ff0 software TLS value, then
|
|
.endr @ pad up to __kuser_helper_version
|
|
|
|
__kuser_helper_version: @ 0xffff0ffc
|
|
.word ((__kuser_helper_end - __kuser_helper_start) >> 5)
|
|
|
|
.globl __kuser_helper_end
|
|
__kuser_helper_end:
|
|
|
|
THUMB( .thumb )
|
|
|
|
/*
|
|
* Vector stubs.
|
|
*
|
|
* This code is copied to 0xffff0200 so we can use branches in the
|
|
* vectors, rather than ldr's. Note that this code must not
|
|
* exceed 0x300 bytes.
|
|
*
|
|
* Common stub entry macro:
|
|
* Enter in IRQ mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
|
|
*
|
|
* SP points to a minimal amount of processor-private memory, the address
|
|
* of which is copied into r0 for the mode specific abort handler.
|
|
*/
|
|
.macro vector_stub, name, mode, correction=0
|
|
.align 5
|
|
|
|
vector_\name:
|
|
.if \correction
|
|
sub lr, lr, #\correction
|
|
.endif
|
|
|
|
@
|
|
@ Save r0, lr_<exception> (parent PC) and spsr_<exception>
|
|
@ (parent CPSR)
|
|
@
|
|
stmia sp, {r0, lr} @ save r0, lr
|
|
mrs lr, spsr
|
|
str lr, [sp, #8] @ save spsr
|
|
|
|
@
|
|
@ Prepare for SVC32 mode. IRQs remain disabled.
|
|
@
|
|
mrs r0, cpsr
|
|
eor r0, r0, #(\mode ^ SVC_MODE | PSR_ISETSTATE)
|
|
msr spsr_cxsf, r0
|
|
|
|
@
|
|
@ the branch table must immediately follow this code
|
|
@
|
|
and lr, lr, #0x0f
|
|
THUMB( adr r0, 1f )
|
|
THUMB( ldr lr, [r0, lr, lsl #2] )
|
|
mov r0, sp
|
|
ARM( ldr lr, [pc, lr, lsl #2] )
|
|
movs pc, lr @ branch to handler in SVC mode
|
|
ENDPROC(vector_\name)
|
|
|
|
.align 2
|
|
@ handler addresses follow this label
|
|
1:
|
|
.endm
|
|
|
|
.globl __stubs_start
|
|
__stubs_start:
|
|
/*
|
|
* Interrupt dispatcher
|
|
*/
|
|
vector_stub irq, IRQ_MODE, 4
|
|
|
|
.long __irq_usr @ 0 (USR_26 / USR_32)
|
|
.long __irq_invalid @ 1 (FIQ_26 / FIQ_32)
|
|
.long __irq_invalid @ 2 (IRQ_26 / IRQ_32)
|
|
.long __irq_svc @ 3 (SVC_26 / SVC_32)
|
|
.long __irq_invalid @ 4
|
|
.long __irq_invalid @ 5
|
|
.long __irq_invalid @ 6
|
|
.long __irq_invalid @ 7
|
|
.long __irq_invalid @ 8
|
|
.long __irq_invalid @ 9
|
|
.long __irq_invalid @ a
|
|
.long __irq_invalid @ b
|
|
.long __irq_invalid @ c
|
|
.long __irq_invalid @ d
|
|
.long __irq_invalid @ e
|
|
.long __irq_invalid @ f
|
|
|
|
/*
|
|
* Data abort dispatcher
|
|
* Enter in ABT mode, spsr = USR CPSR, lr = USR PC
|
|
*/
|
|
vector_stub dabt, ABT_MODE, 8
|
|
|
|
.long __dabt_usr @ 0 (USR_26 / USR_32)
|
|
.long __dabt_invalid @ 1 (FIQ_26 / FIQ_32)
|
|
.long __dabt_invalid @ 2 (IRQ_26 / IRQ_32)
|
|
.long __dabt_svc @ 3 (SVC_26 / SVC_32)
|
|
.long __dabt_invalid @ 4
|
|
.long __dabt_invalid @ 5
|
|
.long __dabt_invalid @ 6
|
|
.long __dabt_invalid @ 7
|
|
.long __dabt_invalid @ 8
|
|
.long __dabt_invalid @ 9
|
|
.long __dabt_invalid @ a
|
|
.long __dabt_invalid @ b
|
|
.long __dabt_invalid @ c
|
|
.long __dabt_invalid @ d
|
|
.long __dabt_invalid @ e
|
|
.long __dabt_invalid @ f
|
|
|
|
/*
|
|
* Prefetch abort dispatcher
|
|
* Enter in ABT mode, spsr = USR CPSR, lr = USR PC
|
|
*/
|
|
vector_stub pabt, ABT_MODE, 4
|
|
|
|
.long __pabt_usr @ 0 (USR_26 / USR_32)
|
|
.long __pabt_invalid @ 1 (FIQ_26 / FIQ_32)
|
|
.long __pabt_invalid @ 2 (IRQ_26 / IRQ_32)
|
|
.long __pabt_svc @ 3 (SVC_26 / SVC_32)
|
|
.long __pabt_invalid @ 4
|
|
.long __pabt_invalid @ 5
|
|
.long __pabt_invalid @ 6
|
|
.long __pabt_invalid @ 7
|
|
.long __pabt_invalid @ 8
|
|
.long __pabt_invalid @ 9
|
|
.long __pabt_invalid @ a
|
|
.long __pabt_invalid @ b
|
|
.long __pabt_invalid @ c
|
|
.long __pabt_invalid @ d
|
|
.long __pabt_invalid @ e
|
|
.long __pabt_invalid @ f
|
|
|
|
/*
|
|
* Undef instr entry dispatcher
|
|
* Enter in UND mode, spsr = SVC/USR CPSR, lr = SVC/USR PC
|
|
*/
|
|
vector_stub und, UND_MODE
|
|
|
|
.long __und_usr @ 0 (USR_26 / USR_32)
|
|
.long __und_invalid @ 1 (FIQ_26 / FIQ_32)
|
|
.long __und_invalid @ 2 (IRQ_26 / IRQ_32)
|
|
.long __und_svc @ 3 (SVC_26 / SVC_32)
|
|
.long __und_invalid @ 4
|
|
.long __und_invalid @ 5
|
|
.long __und_invalid @ 6
|
|
.long __und_invalid @ 7
|
|
.long __und_invalid @ 8
|
|
.long __und_invalid @ 9
|
|
.long __und_invalid @ a
|
|
.long __und_invalid @ b
|
|
.long __und_invalid @ c
|
|
.long __und_invalid @ d
|
|
.long __und_invalid @ e
|
|
.long __und_invalid @ f
|
|
|
|
.align 5
|
|
|
|
/*=============================================================================
|
|
* Undefined FIQs
|
|
*-----------------------------------------------------------------------------
|
|
* Enter in FIQ mode, spsr = ANY CPSR, lr = ANY PC
|
|
* MUST PRESERVE SVC SPSR, but need to switch to SVC mode to show our msg.
|
|
* Basically to switch modes, we *HAVE* to clobber one register... brain
|
|
* damage alert! I don't think that we can execute any code in here in any
|
|
* other mode than FIQ... Ok you can switch to another mode, but you can't
|
|
* get out of that mode without clobbering one register.
|
|
*/
|
|
vector_fiq:
|
|
subs pc, lr, #4
|
|
|
|
/*=============================================================================
|
|
* Address exception handler
|
|
*-----------------------------------------------------------------------------
|
|
* These aren't too critical.
|
|
* (they're not supposed to happen, and won't happen in 32-bit data mode).
|
|
*/
|
|
|
|
vector_addrexcptn:
|
|
b vector_addrexcptn
|
|
|
|
/*
|
|
* We group all the following data together to optimise
|
|
* for CPUs with separate I & D caches.
|
|
*/
|
|
.align 5
|
|
|
|
.LCvswi:
|
|
.word vector_swi
|
|
|
|
.globl __stubs_end
|
|
__stubs_end:
|
|
|
|
.equ stubs_offset, __vectors_start + 0x200 - __stubs_start
|
|
|
|
.globl __vectors_start
|
|
__vectors_start:
|
|
ARM( swi SYS_ERROR0 )
|
|
THUMB( svc #0 )
|
|
THUMB( nop )
|
|
W(b) vector_und + stubs_offset
|
|
W(ldr) pc, .LCvswi + stubs_offset
|
|
W(b) vector_pabt + stubs_offset
|
|
W(b) vector_dabt + stubs_offset
|
|
W(b) vector_addrexcptn + stubs_offset
|
|
W(b) vector_irq + stubs_offset
|
|
W(b) vector_fiq + stubs_offset
|
|
|
|
.globl __vectors_end
|
|
__vectors_end:
|
|
|
|
.data
|
|
|
|
.globl cr_alignment
|
|
.globl cr_no_alignment
|
|
cr_alignment:
|
|
.space 4
|
|
cr_no_alignment:
|
|
.space 4
|
|
|
|
#ifdef CONFIG_MULTI_IRQ_HANDLER
|
|
.globl handle_arch_irq
|
|
handle_arch_irq:
|
|
.space 4
|
|
#endif
|