From f0aff25570003fc618c47dec36852fc7d80436ee Mon Sep 17 00:00:00 2001 From: Fabian Aggeler Date: Tue, 27 May 2014 17:09:49 +0100 Subject: [PATCH] target-arm: implement CPACR register logic for ARMv7 In ARMv7 the CPACR register allows to control access rights to coprocessor 0-13 interfaces. Bits corresponding to unimplemented coprocessors should be RAZ/WI. Bits ASEDIS, D32DIS, TRCDIS are UNK/SBZP if VFP is not implemented and RAO/WI in some cases. Treating TRCDIS as RAZ/WI since we neither implement a trace macrocell nor a CP14 interface to the trace macrocell registers. Since CPACR bits for VFP/Neon access are honoured with the CPACR_FPEN bit in the TB flags, flushing the TLB is not necessary anymore. Signed-off-by: Fabian Aggeler Message-id: 1400532968-30668-1-git-send-email-aggelerf@ethz.ch Signed-off-by: Peter Maydell --- target-arm/helper.c | 32 ++++++++++++++++++++++++++++---- 1 file changed, 28 insertions(+), 4 deletions(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index 417161e216..cb59f00d54 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -477,11 +477,35 @@ static const ARMCPRegInfo not_v7_cp_reginfo[] = { static void cpacr_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value) { - if (env->cp15.c1_coproc != value) { - env->cp15.c1_coproc = value; - /* ??? Is this safe when called from within a TB? */ - tb_flush(env); + uint32_t mask = 0; + + /* In ARMv8 most bits of CPACR_EL1 are RES0. */ + if (!arm_feature(env, ARM_FEATURE_V8)) { + /* ARMv7 defines bits for unimplemented coprocessors as RAZ/WI. + * ASEDIS [31] and D32DIS [30] are both UNK/SBZP without VFP. + * TRCDIS [28] is RAZ/WI since we do not implement a trace macrocell. + */ + if (arm_feature(env, ARM_FEATURE_VFP)) { + /* VFP coprocessor: cp10 & cp11 [23:20] */ + mask |= (1 << 31) | (1 << 30) | (0xf << 20); + + if (!arm_feature(env, ARM_FEATURE_NEON)) { + /* ASEDIS [31] bit is RAO/WI */ + value |= (1 << 31); + } + + /* VFPv3 and upwards with NEON implement 32 double precision + * registers (D0-D31). + */ + if (!arm_feature(env, ARM_FEATURE_NEON) || + !arm_feature(env, ARM_FEATURE_VFP3)) { + /* D32DIS [30] is RAO/WI if D16-31 are not implemented. */ + value |= (1 << 30); + } + } + value &= mask; } + env->cp15.c1_coproc = value; } static const ARMCPRegInfo v6_cp_reginfo[] = {