diff options
Diffstat (limited to 'arch/arm/include/asm/assembler.h')
| -rw-r--r-- | arch/arm/include/asm/assembler.h | 37 |
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h index 5c8b3bf4d82..eb87200aa4b 100644 --- a/arch/arm/include/asm/assembler.h +++ b/arch/arm/include/asm/assembler.h @@ -22,6 +22,7 @@ #include <asm/ptrace.h> #include <asm/domain.h> +#include <asm/opcodes-virt.h> #define IOMEM(x) (x) @@ -240,6 +241,42 @@ #endif /* + * Helper macro to enter SVC mode cleanly and mask interrupts. reg is + * a scratch register for the macro to overwrite. + * + * This macro is intended for forcing the CPU into SVC mode at boot time. + * you cannot return to the original mode. + * + * Beware, it also clobers LR. + */ +.macro safe_svcmode_maskall reg:req +#if __LINUX_ARM_ARCH__ >= 6 + mrs \reg , cpsr + mov lr , \reg + and lr , lr , #MODE_MASK + cmp lr , #HYP_MODE + orr \reg , \reg , #PSR_I_BIT | PSR_F_BIT + bic \reg , \reg , #MODE_MASK + orr \reg , \reg , #SVC_MODE +THUMB( orr \reg , \reg , #PSR_T_BIT ) + bne 1f + orr \reg, \reg, #PSR_A_BIT + adr lr, BSYM(2f) + msr spsr_cxsf, \reg + __MSR_ELR_HYP(14) + __ERET +1: msr cpsr_c, \reg +2: +#else +/* + * workaround for possibly broken pre-v6 hardware + * (akita, Sharp Zaurus C-1000, PXA270-based) + */ + setmode PSR_F_BIT | PSR_I_BIT | SVC_MODE, \reg +#endif +.endm + +/* * STRT/LDRT access macros with ARM and Thumb-2 variants */ #ifdef CONFIG_THUMB2_KERNEL |