diff options
Diffstat (limited to 'arch/arm/kernel/fiqasm.S')
| -rw-r--r-- | arch/arm/kernel/fiqasm.S | 49 |
1 files changed, 49 insertions, 0 deletions
diff --git a/arch/arm/kernel/fiqasm.S b/arch/arm/kernel/fiqasm.S new file mode 100644 index 0000000000..8dd26e1a9b --- /dev/null +++ b/arch/arm/kernel/fiqasm.S @@ -0,0 +1,49 @@ +/* + * 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) |