Alvise Rigo <a.r...@virtualopensystems.com> writes:
> Use the new slow path for atomic instruction translation when the
> softmmu is enabled.
>
> At the moment only arm and aarch64 use the new LL/SC backend. It is
> possible to disable such backed with --disable-arm-llsc-backend.
Do we want to disable the backend once it is merged? Does it serve a
purpose other than to confuse the user?
>
> Suggested-by: Jani Kokkonen <jani.kokko...@huawei.com>
> Suggested-by: Claudio Fontana <claudio.font...@huawei.com>
> Signed-off-by: Alvise Rigo <a.r...@virtualopensystems.com>
> ---
> configure | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
>
> diff --git a/configure b/configure
> index 44ac9ab..915efcc 100755
> --- a/configure
> +++ b/configure
> @@ -294,6 +294,7 @@ solaris="no"
> profiler="no"
> cocoa="no"
> softmmu="yes"
> +arm_tcg_use_llsc="yes"
> linux_user="no"
> bsd_user="no"
> aix="no"
> @@ -880,6 +881,10 @@ for opt do
> ;;
> --disable-debug-tcg) debug_tcg="no"
> ;;
> + --enable-arm-llsc-backend) arm_tcg_use_llsc="yes"
> + ;;
> + --disable-arm-llsc-backend) arm_tcg_use_llsc="no"
> + ;;
> --enable-debug)
> # Enable debugging options that aren't excessively noisy
> debug_tcg="yes"
> @@ -4751,6 +4756,7 @@ echo "host CPU $cpu"
> echo "host big endian $bigendian"
> echo "target list $target_list"
> echo "tcg debug enabled $debug_tcg"
> +echo "arm use llsc backend" $arm_tcg_use_llsc
> echo "gprof enabled $gprof"
> echo "sparse enabled $sparse"
> echo "strip binaries $strip_opt"
> @@ -4806,6 +4812,7 @@ echo "Install blobs $blobs"
> echo "KVM support $kvm"
> echo "RDMA support $rdma"
> echo "TCG interpreter $tcg_interpreter"
> +echo "use ld/st excl $softmmu"
I think we can drop everything above here.
> echo "fdt support $fdt"
> echo "preadv support $preadv"
> echo "fdatasync $fdatasync"
> @@ -5863,6 +5870,13 @@ fi
> echo "LDFLAGS+=$ldflags" >> $config_target_mak
> echo "QEMU_CFLAGS+=$cflags" >> $config_target_mak
>
> +# Use tcg LL/SC tcg backend for exclusive instruction is arm/aarch64
> +# softmmus targets
> +if test "$arm_tcg_use_llsc" = "yes" ; then
> + if test "$target" = "arm-softmmu" ; then
> + echo "CONFIG_ARM_USE_LDST_EXCL=y" >> $config_target_mak
> + fi
> +fi
This isn't going to be just ARM specific and it will be progressively
turned on for other arches. So perhaps with the CONFIG_SOFTMMU section:
if test "$target_softmmu" = "yes" ; then
echo "CONFIG_SOFTMMU=y" >> $config_target_mak
# Use SoftMMU LL/SC primitives?
case "$target_name" in
arm | aarch64)
echo "CONFIG_USE_LDST_EXCL=y" >> $config_target_mak
;;
esac
fi
> done # for target in $targets
>
> if [ "$pixman" = "internal" ]; then
--
Alex Bennée
