dc2eb928a1
* To remove the risk of inconvenient register allocation decisions by the compiler, these functions are separated out as pure assembler. * The apcs frame manipulation code is not applicable for Thumb-2 (and also not easily compatible). Since it's not essential to have a full frame on these leaf assembler functions, the frame manipulation is removed, in the interests of simplicity. * Split up ldm/stm instructions to be compatible with Thumb-2, as well as avoiding instruction forms deprecated on >= ARMv7. Signed-off-by: Dave Martin <dave.martin@linaro.org> Reviewed-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
50 lines
1.2 KiB
ArmAsm
50 lines
1.2 KiB
ArmAsm
/*
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* linux/arch/arm/kernel/fiqasm.S
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*
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* Derived from code originally in linux/arch/arm/kernel/fiq.c:
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*
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* Copyright (C) 1998 Russell King
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* Copyright (C) 1998, 1999 Phil Blundell
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* Copyright (C) 2011, Linaro Limited
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*
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* FIQ support written by Philip Blundell <philb@gnu.org>, 1998.
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*
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* FIQ support re-written by Russell King to be more generic
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*
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* v7/Thumb-2 compatibility modifications by Linaro Limited, 2011.
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*/
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#include <linux/linkage.h>
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#include <asm/assembler.h>
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/*
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* Taking an interrupt in FIQ mode is death, so both these functions
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* disable irqs for the duration.
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*/
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ENTRY(__set_fiq_regs)
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mov r2, #PSR_I_BIT | PSR_F_BIT | FIQ_MODE
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mrs r1, cpsr
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msr cpsr_c, r2 @ select FIQ mode
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mov r0, r0 @ avoid hazard prior to ARMv4
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ldmia r0!, {r8 - r12}
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ldr sp, [r0], #4
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ldr lr, [r0]
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msr cpsr_c, r1 @ return to SVC mode
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mov r0, r0 @ avoid hazard prior to ARMv4
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mov pc, lr
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ENDPROC(__set_fiq_regs)
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ENTRY(__get_fiq_regs)
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mov r2, #PSR_I_BIT | PSR_F_BIT | FIQ_MODE
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mrs r1, cpsr
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msr cpsr_c, r2 @ select FIQ mode
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mov r0, r0 @ avoid hazard prior to ARMv4
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stmia r0!, {r8 - r12}
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str sp, [r0], #4
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str lr, [r0]
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msr cpsr_c, r1 @ return to SVC mode
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mov r0, r0 @ avoid hazard prior to ARMv4
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mov pc, lr
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ENDPROC(__get_fiq_regs)
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