Re: [PATCH] powerpc/powernv: retrieve m64_bar_idx from device node

[Wei Yang <weiyang@linux.vnet.ibm.com>]

On Wed, Oct 21, 2015 at 06:52:51PM +1100, Michael Ellerman wrote:
>On Wed, 2015-10-21 at 15:17 +0800, Wei Yang wrote:
>
>> Count of M64 BAR would differ with the evolution of hardware.
>> 
>> This patch retieves this count from device node instead of a hard coded
>> value.
>> 
>> Signed-off-by: Wei Yang <weiyang@linux.vnet.ibm.com>
>> ---
>>  arch/powerpc/platforms/powernv/pci-ioda.c | 7 ++++++-
>>  1 file changed, 6 insertions(+), 1 deletion(-)
>> 
>> diff --git a/arch/powerpc/platforms/powernv/pci-ioda.c b/arch/powerpc/platforms/powernv/pci-ioda.c
>> index 5c65d8f..4635d25 100644
>> --- a/arch/powerpc/platforms/powernv/pci-ioda.c
>> +++ b/arch/powerpc/platforms/powernv/pci-ioda.c
>> @@ -368,6 +368,7 @@ static void __init pnv_ioda_parse_m64_window(struct pnv_phb *phb)
>>  	struct resource *res;
>>  	const u32 *r;
>>  	u64 pci_addr;
>> +	const __be32 *prop32;
>>  
>>  	/* FIXME: Support M64 for P7IOC */
>>  	if (phb->type != PNV_PHB_IODA2) {
>> @@ -402,7 +403,11 @@ static void __init pnv_ioda_parse_m64_window(struct pnv_phb *phb)
>>  			res->start, res->end, pci_addr);
>>  
>>  	/* Use last M64 BAR to cover M64 window */
>> -	phb->ioda.m64_bar_idx = 15;
>> +	prop32 = of_get_property(dn, "ibm,opal-m64-count", NULL);
>> +	if (prop32)
>> +		phb->ioda.m64_bar_idx = be32_to_cpup(prop32) - 1;
>> +	else
>> +		phb->ioda.m64_bar_idx = 15;
>
>Please use of_property_read_u32() instead of using of_get_property() directly.
>
>Also the "-1" is a bit unclear, I think it would be clearer if you did
>something like:
>
>	if (of_property_read_u32(dn, "ibm,opal-m64-count", &count))
>		count = 16;
>
>	/* Use last M64 BAR to cover M64 window */
>	phb->ioda.m64_bar_idx = count - 1;
>

Ok, thanks for the suggestion :-)

>
>cheers

-- 
Richard Yang
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