diff options
| author | Jerome Forissier <jerome.forissier@linaro.org> | 2025-04-04 15:50:35 +0200 |
|---|---|---|
| committer | Tom Rini <trini@konsulko.com> | 2025-04-14 08:59:39 -0600 |
| commit | 6fe50e39508043f386fc1bd40bbc02b8a75c1940 (patch) | |
| tree | 0aac1d9565fef925db1e0610a5399ee33a747f76 /arch/arm/include/asm/system.h | |
| parent | d08653d3699c1aafada3418c9f74b887bfb21a65 (diff) | |
arm: asm/system.h: mrc and mcr need .arm if __thumb2__ is not set
The mcr and msr instructions are available in Thumb mode only if
Thumb2 is supported. Therefore, if __thumb2__ is not set, make
sure we switch to ARM mode by inserting a .arm directive in the
inline assembly.
Fixes LTO link errors with kirkwood platforms, triggered by a later
commit:
tools/buildman/buildman -o /tmp/build -eP sheevaplug
[...]
{standard input}:24085: Error: selected processor does not support `mrc p15,0,r3,c1,c0,0' in Thumb mode
Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Diffstat (limited to 'arch/arm/include/asm/system.h')
| -rw-r--r-- | arch/arm/include/asm/system.h | 22 |
1 files changed, 17 insertions, 5 deletions
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index 849b3d0efb7..4c1b81483c9 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -428,11 +428,21 @@ void switch_to_hypervisor_ret(void); #define wfi() #endif +#if !defined(__thumb2__) +/* + * We will need to switch to ARM mode (.arm) for some instructions such as + * mrc p15 etc. + */ +#define asm_arm_or_thumb2(insn) asm volatile(".arm\n\t" insn) +#else +#define asm_arm_or_thumb2(insn) asm volatile(insn) +#endif + static inline unsigned long read_mpidr(void) { unsigned long val; - asm volatile("mrc p15, 0, %0, c0, c0, 5" : "=r" (val)); + asm_arm_or_thumb2("mrc p15, 0, %0, c0, c0, 5" : "=r" (val)); return val; } @@ -461,11 +471,13 @@ static inline unsigned int get_cr(void) unsigned int val; if (is_hyp()) - asm volatile("mrc p15, 4, %0, c1, c0, 0 @ get CR" : "=r" (val) + asm_arm_or_thumb2("mrc p15, 4, %0, c1, c0, 0 @ get CR" + : "=r" (val) : : "cc"); else - asm volatile("mrc p15, 0, %0, c1, c0, 0 @ get CR" : "=r" (val) + asm_arm_or_thumb2("mrc p15, 0, %0, c1, c0, 0 @ get CR" + : "=r" (val) : : "cc"); return val; @@ -474,11 +486,11 @@ static inline unsigned int get_cr(void) static inline void set_cr(unsigned int val) { if (is_hyp()) - asm volatile("mcr p15, 4, %0, c1, c0, 0 @ set CR" : + asm_arm_or_thumb2("mcr p15, 4, %0, c1, c0, 0 @ set CR" : : "r" (val) : "cc"); else - asm volatile("mcr p15, 0, %0, c1, c0, 0 @ set CR" : + asm_arm_or_thumb2("mcr p15, 0, %0, c1, c0, 0 @ set CR" : : "r" (val) : "cc"); isb(); |