Re: [Linux-nvdimm] [PATCH 05/21] nfit-test: manufactured NFITs for interface development

[Dan Williams <dan.j.williams@intel.com>]

On Fri, Apr 24, 2015 at 2:59 PM, Linda Knippers <linda.knippers@hp.com> wrote:
> On 4/24/2015 5:50 PM, Dan Williams wrote:
>> On Fri, Apr 24, 2015 at 2:47 PM, Linda Knippers <linda.knippers@hp.com> wrote:
>>> On 4/17/2015 9:35 PM, Dan Williams wrote:
>>> :
>>>> diff --git a/drivers/block/nd/Kconfig b/drivers/block/nd/Kconfig
>>>> index 5fa74f124b3e..0106b3807202 100644
>>>> --- a/drivers/block/nd/Kconfig
>>>> +++ b/drivers/block/nd/Kconfig
>>>> @@ -41,4 +41,24 @@ config NFIT_ACPI
>>>>         register the platform-global NFIT blob with the core.  Also
>>>>         enables the core to craft ACPI._DSM messages for platform/dimm
>>>>         configuration.
>>>> +
>>>> +config NFIT_TEST
>>>> +     tristate "NFIT TEST: Manufactured NFIT for interface testing"
>>>> +     depends on DMA_CMA
>>>> +     depends on ND_CORE=m
>>>> +     depends on m
>>>> +     help
>>>> +       For development purposes register a manufactured
>>>> +       NFIT table to verify the resulting device model topology.
>>>> +       Note, this module arranges for ioremap_cache() to be
>>>> +       overridden locally to allow simulation of system-memory as an
>>>> +       io-memory-resource.
>>>> +
>>>> +       Note, this test expects to be able to find at least
>>>> +       256MB of CMA space (CONFIG_CMA_SIZE_MBYTES) or it will fail to
>>>
>>> It seems to actually be wanting >= 584MB.
>>
>> Ah, true, this Kconfig text is stale.  Will fix.
>
> Thanks.  One more question...
>
>> +#ifdef CONFIG_CMA_SIZE_MBYTES
>> +#define CMA_SIZE_MBYTES CONFIG_CMA_SIZE_MBYTES
>> +#else
>> +#define CMA_SIZE_MBYTES 0
>> +#endif
>> +
>> +static __init int nfit_test_init(void)
>> +{
>> +     int rc, i;
>> +
>> +     if (CMA_SIZE_MBYTES < 584) {
>> +             pr_err("need CONFIG_CMA_SIZE_MBYTES >= 584 to load\n");
>> +             return -EINVAL;
>> +     }
>> +
>
> Since the kernel takes a cma= boot parameter, it would be nice if
> this check is against what the kernel is using rather than the config
> option.  Is that possible?

Yeah, that would be more friendly.  I also think we can reduce the BLK
aperture sizes.  Since those don't need to be DAX capable they can
come from vmalloc memory rather than CMA.  I'll take a look.