Re: [Qemu-devel] [PATCH] atomic.h: Set ATOMIC_REG_SIZE=8 for MIPS n32

[Richard Henderson <rth@twiddle.net>]

On 12/5/18 4:11 PM, Paul Burton wrote:
> ATOMIC_REG_SIZE is currently defined as the default sizeof(void *) for
> all MIPS host builds, including those using the n32 ABI. n32 is the
> MIPS64 ILP32 ABI and as such tcg/mips/tcg-target.h defines
> TCG_TARGET_REG_BITS as 64 for n32 builds. If we attempt to build QEMU
> for an n32 host with support for a 64b target architecture then
> TCG_OVERSIZED_GUEST is 0 and accel/tcg/cputlb.c attempts to use atomic_*
> functions. This fails because ATOMIC_REG_SIZE is 4, causing the calls to
> QEMU_BUILD_BUG_ON(sizeof(*ptr) > ATOMIC_REG_SIZE) in the various
> atomic_* functions to generate errors.
> 
> Fix this by defining ATOMIC_REG_SIZE as 8 for all MIPS64 builds, which
> will cover both n32 (ILP32) & n64 (LP64) ABIs in much the same was as we
> already do for x86_64/x32.
> 
> Signed-off-by: Paul Burton <paul.burton@mips.com>
> ---
>  include/qemu/atomic.h | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~