[PATCH V4 5/5] arm: mvebu: Added SMP support for Armada XP

Gregory CLEMENT gregory.clement at free-electrons.com
Tue Nov 20 11:49:29 EST 2012


On 11/20/2012 05:40 PM, Will Deacon wrote:
> On Mon, Nov 19, 2012 at 08:35:59PM +0000, Gregory CLEMENT wrote:
>> +/*
>> + * Armada XP specific entry point for secondary CPUs.
>> + * We add the CPU to the coherency fabric and then jump to secondary
>> + * startup
>> + */
>> +ENTRY(armada_xp_secondary_startup)
>> +
>> +	/* Read CPU id */
>> + 	mrc     p15, 0, r1, c0, c0, 5
>> +	and     r1, r1, #0xF
>> +
>> +	/* Add CPU to coherency fabric */
>> +
>> +	ldr     r0, = ARMADA_XP_CFB_BASE
>> +	mov	lr, pc
>> +	b	ll_set_cpu_coherent
>> +	b	secondary_startup
> 
> adr	lr, BSYM(secondary_startup)
> bl	ll_set_cpu_coherent

I will try it.

> 
> should let you get rid of the mov, b, b, although I think you could do
> better than that by making this function a prefix of ll_set_cpu_coherent:
> 
> ENTRY(armada_xp_secondary_startup)
> 	ldr     r0, =ARMADA_XP_CFB_BASE
> 	mrc     p15, 0, r1, c0, c0, 5
> 	and     r1, r1, #0xF
> 	adr	lr, BSYM(secondary_startup)
> 
> 	/* Fallthrough */
> 
> ENTRY(ll_set_cpu_coherent)
> ...
> ENDPROC(ll_set_cpu_coherent)
> ENDPROC(armada_xp_secondary_startup)
> 
> what do you think?
> 

I prefer to keep them separate, as we can use coherency without SMP.
That's why I create the coherency_ll.S file instead of putting everything
in this file.


> Will
> 


-- 
Gregory Clement, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com



More information about the linux-arm-kernel mailing list