Re: [Qemu-devel] [PATCH 8/8] linux-user: Enable NPTL for m68k

[Laurent Vivier <Laurent@Vivier.EU>]

Le 12/07/2013 22:12, Peter Maydell a écrit :
> For m68k, per-thread data is a purely kernel construct with no
> CPU level support. Implement it via a field in the TaskState structure,
> used by cpu_set_tls() and the set_thread_area/get_thread_area
> syscalls. This allows us to enable compilation with NPTL.
>
> Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

tp_value is never read : is it really used ?

> ---
>   configure                    |    1 -
>   linux-user/m68k/target_cpu.h |    6 +++++-
>   linux-user/qemu.h            |    1 +
>   linux-user/syscall.c         |   10 ++++++++++
>   4 files changed, 16 insertions(+), 2 deletions(-)
>
> diff --git a/configure b/configure
> index 117191e..67e6437 100755
> --- a/configure
> +++ b/configure
> @@ -4203,7 +4203,6 @@ case "$target_name" in
>     m68k)
>       bflt="yes"
>       gdb_xml_files="cf-core.xml cf-fp.xml"
> -    target_nptl="no"
>     ;;
>     microblaze|microblazeel)
>       TARGET_ARCH=microblaze
> diff --git a/linux-user/m68k/target_cpu.h b/linux-user/m68k/target_cpu.h
> index 8a2a305..cad9c90 100644
> --- a/linux-user/m68k/target_cpu.h
> +++ b/linux-user/m68k/target_cpu.h
> @@ -29,6 +29,10 @@ static inline void cpu_clone_regs(CPUM68KState *env, target_ulong newsp)
>       env->dregs[0] = 0;
>   }
>   
> -/* TODO: need to implement cpu_set_tls() */
> +static inline void cpu_set_tls(CPUM68KState *env, target_ulong newtls)
> +{
> +    TaskState *ts = env->opaque;
> +    ts->tp_value = newtls;
> +}
>   
>   #endif
> diff --git a/linux-user/qemu.h b/linux-user/qemu.h
> index 8c420da..1ff0fa8 100644
> --- a/linux-user/qemu.h
> +++ b/linux-user/qemu.h
> @@ -121,6 +121,7 @@ typedef struct TaskState {
>   #endif
>   #ifdef TARGET_M68K
>       int sim_syscalls;
> +    abi_ulong tp_value;
>   #endif
>   #if defined(TARGET_ARM) || defined(TARGET_M68K) || defined(TARGET_UNICORE32)
>       /* Extra fields for semihosted binaries.  */
> diff --git a/linux-user/syscall.c b/linux-user/syscall.c
> index 00a0390..c580793 100644
> --- a/linux-user/syscall.c
> +++ b/linux-user/syscall.c
> @@ -8558,6 +8558,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
>   #elif defined(TARGET_I386) && defined(TARGET_ABI32)
>         ret = do_set_thread_area(cpu_env, arg1);
>         break;
> +#elif defined(TARGET_M68K)
> +      {
> +          TaskState *ts = ((CPUArchState *)cpu_env)->opaque;
> +          ts->tp_value = arg1;
> +      }
Seems a "break" is missing here ?
>   #else
>         goto unimplemented_nowarn;
>   #endif
> @@ -8566,6 +8571,11 @@ abi_long do_syscall(void *cpu_env, int num, abi_long arg1,
>       case TARGET_NR_get_thread_area:
>   #if defined(TARGET_I386) && defined(TARGET_ABI32)
>           ret = do_get_thread_area(cpu_env, arg1);
> +#elif defined(TARGET_M68K)
> +        {
> +            TaskState *ts = ((CPUArchState *)cpu_env)->opaque;
> +            ts->tp_value = arg1;
perhaps "ret = ts->tp_value;" ?
> +        }
>   #else
>           goto unimplemented_nowarn;
>   #endif