Hi Simon,
On Mon, Jun 15, 2020 at 1:00 AM Simon Glass <s...@chromium.org> wrote:
>
> With the new MP features the CPUs are no-longer parked when the OS is run.
> Fix this by calling a special function to park them, just before the OS is
> started.
>
> Signed-off-by: Simon Glass <s...@chromium.org>
> Reviewed-by: Wolfgang Wallner <wolfgang.wall...@br-automation.com>
> ---
>
> (no changes since v1)
>
> arch/x86/cpu/cpu.c | 5 +++++
> arch/x86/cpu/mp_init.c | 18 ++++++++++++++++++
> arch/x86/include/asm/mp.h | 17 +++++++++++++++++
> 3 files changed, 40 insertions(+)
>
> diff --git a/arch/x86/cpu/cpu.c b/arch/x86/cpu/cpu.c
> index d0720fb7fb..baa7dae172 100644
> --- a/arch/x86/cpu/cpu.c
> +++ b/arch/x86/cpu/cpu.c
> @@ -66,6 +66,11 @@ static const char *const x86_vendor_name[] = {
>
> int __weak x86_cleanup_before_linux(void)
> {
> + int ret;
> +
> + ret = mp_park_aps();
> + if (ret)
> + return log_msg_ret("park", ret);
> bootstage_stash((void *)CONFIG_BOOTSTAGE_STASH_ADDR,
> CONFIG_BOOTSTAGE_STASH_SIZE);
>
> diff --git a/arch/x86/cpu/mp_init.c b/arch/x86/cpu/mp_init.c
> index e65c82c8fd..9970b51c8d 100644
> --- a/arch/x86/cpu/mp_init.c
> +++ b/arch/x86/cpu/mp_init.c
> @@ -657,6 +657,24 @@ int mp_run_on_cpus(int cpu_select, mp_run_func func,
> void *arg)
> return 0;
> }
>
> +static void park_this_cpu(void *unused)
> +{
> + stop_this_cpu();
> +}
> +
> +int mp_park_aps(void)
> +{
> + unsigned long start;
> + int ret;
> +
> + start = get_timer(0);
> + ret = mp_run_on_cpus(MP_SELECT_APS, park_this_cpu, NULL);
> + if (ret)
> + return ret;
> +
> + return get_timer(start);
What is this return value for? It seems you wanted to do some timeout check?
> +}
> +
> int mp_init(void)
> {
> int num_aps, num_cpus;
> diff --git a/arch/x86/include/asm/mp.h b/arch/x86/include/asm/mp.h
> index 0272b3c0b6..38961ca44b 100644
> --- a/arch/x86/include/asm/mp.h
> +++ b/arch/x86/include/asm/mp.h
> @@ -106,6 +106,15 @@ typedef void (*mp_run_func)(void *arg);
> * @return 0 on success, -ve on error
> */
> int mp_run_on_cpus(int cpu_select, mp_run_func func, void *arg);
> +
> +/**
> + * mp_park_aps() - Park the APs ready for the OS
> + *
> + * This halts all CPUs except the main one, ready for the OS to use them
> + *
> + * @return 0 on success, -ve on error
The return value does not match the codes
> + */
> +int mp_park_aps(void);
> #else
> static inline int mp_run_on_cpus(int cpu_select, mp_run_func func, void *arg)
> {
> @@ -114,6 +123,14 @@ static inline int mp_run_on_cpus(int cpu_select,
> mp_run_func func, void *arg)
>
> return 0;
> }
> +
> +static inline int mp_park_aps(void)
> +{
> + /* No APs to park */
> +
> + return 0;
> +}
> +
> #endif
>
> #endif /* _X86_MP_H_ */
Regards,
Bin
