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From: Jayachandran C. <jayachandranc@netlogicmicro.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: Hillf Danton <dhillf@gmail.com>, <linux-mips@linux-mips.org>
Subject: Re: [RFC] mark Netlogic XLR chip as SMT capable
Date: Mon, 3 Oct 2011 16:09:36 +0530	[thread overview]
Message-ID: <20111003103935.GA6016@jayachandranc.netlogicmicro.com> (raw)
In-Reply-To: <20111003103204.GC6038@linux-mips.org>

On Mon, Oct 03, 2011 at 11:32:04AM +0100, Ralf Baechle wrote:
> On Mon, Oct 03, 2011 at 01:46:46PM +0800, Hillf Danton wrote:
> 
> > +	unsigned int cpu, core_id;
> > +
> > +	cpu = smp_processor_id();
> > +	core_id = (cpu >> 2) & 0x7;
> > +	cpu_data[cpu].core = core_id;
> 
> This is going to break in setups where Linux is not being booted on
> what the hardware considers CPU core 0.  Which is not uncommon in embedded
> setups.  You may want to probe the hardware for the core ID rather than
> relying on smp_processor_id() here.

Yes, the function hard_smp_processor_id() from netlogic/mips-extns.h has to
be used here.

This also conflicts with the recent patch-set for XLP support, but I don't
know the status of that yet.

JC.

WARNING: multiple messages have this Message-ID (diff)
From: Jayachandran C. <jayachandranc@netlogicmicro.com>
To: Ralf Baechle <ralf@linux-mips.org>
Cc: Hillf Danton <dhillf@gmail.com>, linux-mips@linux-mips.org
Subject: Re: [RFC] mark Netlogic XLR chip as SMT capable
Date: Mon, 3 Oct 2011 16:09:36 +0530	[thread overview]
Message-ID: <20111003103935.GA6016@jayachandranc.netlogicmicro.com> (raw)
Message-ID: <20111003103936.h86j1t3dI_a0rrYkHfKkA6a_jo-Pd5-qlPp8y9wjfVA@z> (raw)
In-Reply-To: <20111003103204.GC6038@linux-mips.org>

On Mon, Oct 03, 2011 at 11:32:04AM +0100, Ralf Baechle wrote:
> On Mon, Oct 03, 2011 at 01:46:46PM +0800, Hillf Danton wrote:
> 
> > +	unsigned int cpu, core_id;
> > +
> > +	cpu = smp_processor_id();
> > +	core_id = (cpu >> 2) & 0x7;
> > +	cpu_data[cpu].core = core_id;
> 
> This is going to break in setups where Linux is not being booted on
> what the hardware considers CPU core 0.  Which is not uncommon in embedded
> setups.  You may want to probe the hardware for the core ID rather than
> relying on smp_processor_id() here.

Yes, the function hard_smp_processor_id() from netlogic/mips-extns.h has to
be used here.

This also conflicts with the recent patch-set for XLP support, but I don't
know the status of that yet.

JC.

  reply	other threads:[~2011-10-03 10:39 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2011-10-02  7:26 [RFC] mark Netlogic XLR chip as SMT capable Hillf Danton
2011-10-02  8:30 ` Jayachandran C.
2011-10-02  8:30   ` Jayachandran C.
2011-10-03  5:46   ` Hillf Danton
2011-10-03 10:32     ` Ralf Baechle
2011-10-03 10:39       ` Jayachandran C. [this message]
2011-10-03 10:39         ` Jayachandran C.
2011-10-04 10:48         ` Hillf Danton

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