Hi Simon,
On Mon, Jun 15, 2020 at 11:58 AM Simon Glass <s...@chromium.org> wrote:
>
> At present if MP is not enabled (e.g. booting from coreboot) the 'mtrr'
> command does not work correctly. It is not easy to make it work for all
> CPUs, since coreboot has halted them and we would need to start them up
> again, but it is easy enough to make them work on the boot CPU.
>
> Update the code to avoid assuming that the MP init routine has completed,
> so that this can work.
>
> Signed-off-by: Simon Glass <s...@chromium.org>
> ---
>
> arch/x86/cpu/mp_init.c | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/arch/x86/cpu/mp_init.c b/arch/x86/cpu/mp_init.c
> index ef33a38017..c0ae24686e 100644
> --- a/arch/x86/cpu/mp_init.c
> +++ b/arch/x86/cpu/mp_init.c
> @@ -454,7 +454,7 @@ static int get_bsp(struct udevice **devp, int *cpu_countp)
> if (cpu_countp)
> *cpu_countp = ret;
>
> - return dev->req_seq;
> + return dev->req_seq >= 0 ? dev->req_seq : 0;
> }
>
> static struct mp_callback *read_callback(struct mp_callback **slot)
> @@ -589,9 +589,6 @@ int mp_run_on_cpus(int cpu_select, mp_run_func func, void
> *arg)
> int num_cpus;
> int ret;
>
> - if (!(gd->flags & GD_FLG_SMP_INIT))
> - return -ENXIO;
> -
> ret = get_bsp(&dev, &num_cpus);
> if (ret < 0)
> return log_msg_ret("bsp", ret);
> @@ -601,6 +598,13 @@ int mp_run_on_cpus(int cpu_select, mp_run_func func,
> void *arg)
> func(arg);
> }
>
> + if (!(gd->flags & GD_FLG_SMP_INIT)) {
> + /* Allow use of this function on the BSP only */
> + if (cpu_select == MP_SELECT_BSP || !cpu_select)
This assumes 0 is the BSP cpu number?
> + return 0;
> + return -ENXIO;
> + }
> +
> /* Allow up to 1 second for all APs to finish */
> ret = run_ap_work(&lcb, dev, num_cpus, 1000 /* ms */);
> if (ret)
> --
Regards,
Bin
