From 8c6afa6ab158467d1938cc92022135bc7a872006 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Tue, 15 Apr 2014 19:18:39 +0100 Subject: target-arm: A64: Correctly fault FP/Neon if CPACR.FPEN set For the A64 instruction set, the only FP/Neon disable trap is the CPACR FPEN bits, which may indicate "enabled", "disabled" or "disabled for EL0". Add a bit to the AArch64 tb flags indicating whether FP/Neon access is currently enabled and make the decoder emit code to raise exceptions on use of FP/Neon insns if it is not. We use a new flag in DisasContext rather than borrowing the existing vfp_enabled flag because the A32/T32 decoder is going to need both. Signed-off-by: Peter Maydell Acked-by: Peter Crosthwaite --- I'm aware this is a rather hard to review patch; sorry. I have done an exhaustive check that we have fp access checks in all code paths with the aid of the assertions added in the next patch plus the code-coverage hack patch I posted to the list earlier. This patch is correct as of 09e037354 target-arm: A64: Add saturating accumulate ops (USQADD/SUQADD) which was the last of the Neon insns to be added, so assuming no refactoring of the code it should be fine. --- target-arm/cpu.h | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'target-arm/cpu.h') diff --git a/target-arm/cpu.h b/target-arm/cpu.h index 7a48241..72c4c7a 100644 --- a/target-arm/cpu.h +++ b/target-arm/cpu.h @@ -1108,6 +1108,8 @@ static inline int cpu_mmu_index (CPUARMState *env) /* Bit usage when in AArch64 state */ #define ARM_TBFLAG_AA64_EL_SHIFT 0 #define ARM_TBFLAG_AA64_EL_MASK (0x3 << ARM_TBFLAG_AA64_EL_SHIFT) +#define ARM_TBFLAG_AA64_FPEN_SHIFT 2 +#define ARM_TBFLAG_AA64_FPEN_MASK (1 << ARM_TBFLAG_AA64_FPEN_SHIFT) /* some convenience accessor macros */ #define ARM_TBFLAG_AARCH64_STATE(F) \ @@ -1128,14 +1130,21 @@ static inline int cpu_mmu_index (CPUARMState *env) (((F) & ARM_TBFLAG_BSWAP_CODE_MASK) >> ARM_TBFLAG_BSWAP_CODE_SHIFT) #define ARM_TBFLAG_AA64_EL(F) \ (((F) & ARM_TBFLAG_AA64_EL_MASK) >> ARM_TBFLAG_AA64_EL_SHIFT) +#define ARM_TBFLAG_AA64_FPEN(F) \ + (((F) & ARM_TBFLAG_AA64_FPEN_MASK) >> ARM_TBFLAG_AA64_FPEN_SHIFT) static inline void cpu_get_tb_cpu_state(CPUARMState *env, target_ulong *pc, target_ulong *cs_base, int *flags) { + int fpen = extract32(env->cp15.c1_coproc, 20, 2); + if (is_a64(env)) { *pc = env->pc; *flags = ARM_TBFLAG_AARCH64_STATE_MASK | (arm_current_pl(env) << ARM_TBFLAG_AA64_EL_SHIFT); + if (fpen == 3 || (fpen == 1 && arm_current_pl(env) != 0)) { + *flags |= ARM_TBFLAG_AA64_FPEN_MASK; + } } else { int privmode; *pc = env->regs[15]; -- cgit v1.1