Re: [PATCH 1/2] MIPS: reserve exception vector space ONLY ONCE

[Thomas Bogendoerfer <tsbogend@alpha.franken.de>]

On Fri, Jan 19, 2024 at 12:02:39PM +0800, Huang Pei wrote:
> "cpu_probe" is called both by BP and APs, but reserving exception vector
> (like 0x0-0x1000) called by "cpu_probe" need once and calling on BPs is
> too late since memblock is unavailable at that time.
> 
> So, reserve exception vector ONLY by BP.
> 
> Signed-off-by: Huang Pei <huangpei@loongson.cn>
> ---
>  arch/mips/kernel/cpu-probe.c | 13 +++++++++----
>  1 file changed, 9 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/mips/kernel/cpu-probe.c b/arch/mips/kernel/cpu-probe.c
> index b406d8bfb15a..6939d0de2a03 100644
> --- a/arch/mips/kernel/cpu-probe.c
> +++ b/arch/mips/kernel/cpu-probe.c
> @@ -1581,7 +1581,9 @@ static inline void cpu_probe_broadcom(struct cpuinfo_mips *c, unsigned int cpu)
>  			__cpu_name[cpu] = "Broadcom BMIPS4380";
>  			set_elf_platform(cpu, "bmips4380");
>  			c->options |= MIPS_CPU_RIXI;
> -			reserve_exception_space(0x400, VECTORSPACING * 64);
> +			if (cpu == 0) {
> +				reserve_exception_space(0x400, VECTORSPACING * 64);
> +			}

why not do a 

if (smp_processor_id() == 0)
	memblock_reserve(...)
		
in reserve_exception_space() ?

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]