On Tue, May 07, 2024 at 10:01:51AM +0100, Jiaxun Yang wrote:
> Move mips_cm_probe after prom_init so we can use fdt functions
> in mips_cm_probe to obtain essential information.
>
> Impat for all systems that may have CM in system:
> - geneirc: Adjusted code to accommodate this change
s/geneirc/generic
> - Lantiq: No impact, CM configuration won't be changed at all
> - ralink: Called mips_cm_probe on it's own, in prom_init->prom_soc_init
> - malta: No impact, CM address comes from CP0_CMGCR
Are you sure about this? This was one of the problematic part I met
back when was trying to implement the feature.
arch/mips/mti-malta/malta-init.c:
prom_init()
+-> mips_cpc_probe()
+-> mips_cpc_phys_base()
+-> mips_cm_present(): mips_gcr_base != NULL
+-> read_gcr_cpc_status()
+-> read_gcr_cpc_base()
+-> write_gcr_cpc_base()
So by moving mips_cm_probe() to being executed after prom_init() the
calls-chain above will be broken since the mips_gcr_base will be left
uninitialized. Do I miss something?
Please, note originally the mips_cm_probe() invocation was right
above the Malta's mips_cpc_probe():
3af5a67c86a3 ("MIPS: Fix early CM probing")
-Serge(y)
>
> Signed-off-by: Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx>
> ---
> arch/mips/kernel/setup.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c
> index 12a1a4ffb602..732579c8f4f8 100644
> --- a/arch/mips/kernel/setup.c
> +++ b/arch/mips/kernel/setup.c
> @@ -773,8 +773,8 @@ static void __init setup_rng_seed(void)
> void __init setup_arch(char **cmdline_p)
> {
> cpu_probe();
> - mips_cm_probe();
> prom_init();
> + mips_cm_probe();
>
> setup_early_fdc_console();
> #ifdef CONFIG_EARLY_PRINTK
>
> --
> 2.34.1
>
>
