• Suzuki K Poulose's avatar
    arm64: Support systems without FP/ASIMD · 82e0191a
    Suzuki K Poulose authored
    The arm64 kernel assumes that FP/ASIMD units are always present
    and accesses the FP/ASIMD specific registers unconditionally. This
    could cause problems when they are absent. This patch adds the
    support for kernel handling systems without FP/ASIMD by skipping the
    register access within the kernel. For kvm, we trap the accesses
    to FP/ASIMD and inject an undefined instruction exception to the VM.
    
    The callers of the exported kernel_neon_begin_partial() should
    make sure that the FP/ASIMD is supported.
    
    Cc: Will Deacon <will.deacon@arm.com>
    Cc: Christoffer Dall <christoffer.dall@linaro.org>
    Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
    Signed-off-by: default avatarSuzuki K Poulose <suzuki.poulose@arm.com>
    Reviewed-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
    [catalin.marinas@arm.com: add comment on the ARM64_HAS_NO_FPSIMD conflict and the new location]
    Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
    82e0191a
hyp-entry.S 4.96 KB