From 70dae0d069c45250bbefd9424089383a8ac239de Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Sat, 8 Feb 2020 12:58:05 +0000 Subject: [PATCH] target/arm: Remove CPSR_RESERVED The only remaining use was in op_helper.c. Use PSTATE_SS directly, and move the commentary so that it is more obvious what is going on. Signed-off-by: Richard Henderson Reviewed-by: Peter Maydell Message-id: 20200208125816.14954-10-richard.henderson@linaro.org Signed-off-by: Peter Maydell --- target/arm/cpu.h | 6 ------ target/arm/op_helper.c | 9 ++++++++- 2 files changed, 8 insertions(+), 7 deletions(-) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 694b074298..c6dff1d55b 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -1186,12 +1186,6 @@ void pmu_init(ARMCPU *cpu); #define CPSR_IT_2_7 (0xfc00U) #define CPSR_GE (0xfU << 16) #define CPSR_IL (1U << 20) -/* Note that the RESERVED bits include bit 21, which is PSTATE_SS in - * an AArch64 SPSR but RES0 in AArch32 SPSR and CPSR. In QEMU we use - * env->uncached_cpsr bit 21 to store PSTATE.SS when executing in AArch32, - * where it is live state but not accessible to the AArch32 code. - */ -#define CPSR_RESERVED (0x7U << 21) #define CPSR_J (1U << 24) #define CPSR_IT_0_1 (3U << 25) #define CPSR_Q (1U << 27) diff --git a/target/arm/op_helper.c b/target/arm/op_helper.c index acf1815ea3..af3020b78f 100644 --- a/target/arm/op_helper.c +++ b/target/arm/op_helper.c @@ -387,7 +387,14 @@ void HELPER(exception_bkpt_insn)(CPUARMState *env, uint32_t syndrome) uint32_t HELPER(cpsr_read)(CPUARMState *env) { - return cpsr_read(env) & ~(CPSR_EXEC | CPSR_RESERVED); + /* + * We store the ARMv8 PSTATE.SS bit in env->uncached_cpsr. + * This is convenient for populating SPSR_ELx, but must be + * hidden from aarch32 mode, where it is not visible. + * + * TODO: ARMv8.4-DIT -- need to move SS somewhere else. + */ + return cpsr_read(env) & ~(CPSR_EXEC | PSTATE_SS); } void HELPER(cpsr_write)(CPUARMState *env, uint32_t val, uint32_t mask)