Re: [v2][PATCH 4/7] book3e/kexec/kdump: introduce a kexec kernelflag

[tiejun.chen]

On 07/02/2013 01:37 PM, Bhushan Bharat-R65777 wrote:
> > -----Original Message-----
> > From: Linuxppc-dev [mailto:linuxppc-dev-
> > bounces+bharat.bhushan=freescale.com@xxxxxxxxxxxxxxxx] On Behalf Of Tiejun Chen
> > Sent: Thursday, June 20, 2013 1:23 PM
> > To: benh@xxxxxxxxxxxxxxxxxxx
> > Cc: linuxppc-dev@xxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx
> > Subject: [v2][PATCH 4/7] book3e/kexec/kdump: introduce a kexec kernel flag
> >
> > We need to introduce a flag to indicate we're already running
> > a kexec kernel then we can go proper path. For example, We
> > shouldn't access spin_table from the bootloader to up any secondary
> > cpu for kexec kernel, and kexec kernel already know how to jump to
> > generic_secondary_smp_init.
> >
> > Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxxxxxx>
> > ---

[snip]

> > +++ b/arch/powerpc/platforms/85xx/smp.c
> > @@ -150,6 +150,9 @@ static int __cpuinit smp_85xx_kick_cpu(int nr)
> >   	int hw_cpu = get_hard_smp_processor_id(nr);
> >   	int ioremappable;
> >   	int ret = 0;
> > +#if defined(CONFIG_KEXEC) || defined(CONFIG_CRASH_DUMP)
> > +	unsigned long *ptr;
> > +#endif
>
> What about if we can remove the ifdef around *ptr ...
>
> >   	WARN_ON(nr < 0 || nr >= NR_CPUS);
> >   	WARN_ON(hw_cpu < 0 || hw_cpu >= NR_CPUS);
> > @@ -238,11 +241,22 @@ out:
> >   #else
> >   	smp_generic_kick_cpu(nr);
> >
> > +#if defined(CONFIG_KEXEC) || defined(CONFIG_CRASH_DUMP)
> > +	ptr  = (unsigned long *)((unsigned long)&__run_at_kexec);
>
> ... #endif here ...
>
> > +	/* We shouldn't access spin_table from the bootloader to up any
> > +	 * secondary cpu for kexec kernel, and kexec kernel already
> > +	 * know how to jump to generic_secondary_smp_init.
> > +	 */
> > +	if (!*ptr) {
> > +#endif
>
> ... remove #endif ...
>
> >   	flush_spin_table(spin_table);
> >   	out_be32(&spin_table->pir, hw_cpu);
> >   	out_be64((u64 *)(&spin_table->addr_h),
> >   	  __pa((u64)*((unsigned long long *)generic_secondary_smp_init)));
> >   	flush_spin_table(spin_table);
> > +#if defined(CONFIG_KEXEC) || defined(CONFIG_CRASH_DUMP)
> > +	}
> > +#endif
>
> --- remove above 3 lines

I'd like to try to address your comments next version.

Thanks

Tiejun
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