linuxdebug/arch/arm/kernel/fiqasm.S

50 lines
1.2 KiB
ArmAsm

/*
* linux/arch/arm/kernel/fiqasm.S
*
* Derived from code originally in linux/arch/arm/kernel/fiq.c:
*
* Copyright (C) 1998 Russell King
* Copyright (C) 1998, 1999 Phil Blundell
* Copyright (C) 2011, Linaro Limited
*
* FIQ support written by Philip Blundell <philb@gnu.org>, 1998.
*
* FIQ support re-written by Russell King to be more generic
*
* v7/Thumb-2 compatibility modifications by Linaro Limited, 2011.
*/
#include <linux/linkage.h>
#include <asm/assembler.h>
/*
* Taking an interrupt in FIQ mode is death, so both these functions
* disable irqs for the duration.
*/
ENTRY(__set_fiq_regs)
mov r2, #PSR_I_BIT | PSR_F_BIT | FIQ_MODE
mrs r1, cpsr
msr cpsr_c, r2 @ select FIQ mode
mov r0, r0 @ avoid hazard prior to ARMv4
ldmia r0!, {r8 - r12}
ldr sp, [r0], #4
ldr lr, [r0]
msr cpsr_c, r1 @ return to SVC mode
mov r0, r0 @ avoid hazard prior to ARMv4
ret lr
ENDPROC(__set_fiq_regs)
ENTRY(__get_fiq_regs)
mov r2, #PSR_I_BIT | PSR_F_BIT | FIQ_MODE
mrs r1, cpsr
msr cpsr_c, r2 @ select FIQ mode
mov r0, r0 @ avoid hazard prior to ARMv4
stmia r0!, {r8 - r12}
str sp, [r0], #4
str lr, [r0]
msr cpsr_c, r1 @ return to SVC mode
mov r0, r0 @ avoid hazard prior to ARMv4
ret lr
ENDPROC(__get_fiq_regs)