On Tue, Mar 19, 2013 at 01:15:02PM -0500, Nathan Fontenot wrote:

On 03/14/2013 08:42 AM, Michael Ellerman wrote:

quoted

On Fri, Mar 08, 2013 at 10:02:31PM -0600, Nathan Fontenot wrote:

quoted

The firmware_has_feature() function makes it easy to check for supported
features of the hardware. There is not corresponding function to check for
features supported by the client architecture.

Actually it doesn't tell you about features of the hardware, it tells
you about features of the firmware, or the platform ..

So I think you should really just be adding a new firmware feature flag,
and adding whatever glue code is required to set it based on what you
find in the device tree.

Also notice where you end up using it:

-       if (firmware_has_feature(FW_FEATURE_OPAL))
+       if (firmware_has_feature(FW_FEATURE_OPAL) ||
+           platform_has_feature(OV5_TYPE1_AFFINITY)) {
+               dbg("Using form 1 affinity\n");
		form1_affinity = 1;

Could be:

+       if (firmware_has_feature(FW_FEATURE_FORM1_AFFINITY) ||

To make sure I understand what you're suggesting...

You think there should be a single firmware_has_feature() for all current
uses and also for checking items such as FORM1_AFFINITY and PRRN 
features as reported by the device tree for vector 5 portions of the
client architecture bits. I think this could be done by checking the
device tree ibm,architecture-vec-5 node for a specified feature and
setting a bit the appropriate bit in powerpc_firmware_features.

Yes that's right.

So you'd add a new FW_FEATURE_FORM1_AFFINITY, and set it depending on what
you find in "ibm,architecture-vec-5" on IBM pseries machines.

As a cleanup you'd also set it unconditionally on OPAL and then the
check above could be simply for FW_FEATURE_FORM1_AFFINITY.

cheers