Re: [PATCH v2 02/17] powerpc/cell: Move data segment faulting code out of cell platform

Michael Ellerman
2014-10-01T06:48:00Z

On Tue, 2014-30-09 at 10:34:51 UTC, Michael Neuling wrote:
> From: Ian Munsie <imunsie@au1.ibm.com>
>
> __spu_trap_data_seg() currently contains code to determine the VSID and ESID
> required for a particular EA and mm struct.
>
> This code is generically useful for other co-processors. This moves the code
> of the cell platform so it can be used by other powerpc code. It also adds 1TB
> segment handling which Cell didn't have.

I'm not loving this.

For starters the name "copro_data_segment()" doesn't contain any verbs, and it
doesn't tell me what it does.

If we give it a name that says what it does, we get copro_get_ea_esid_and_vsid().
Or something equally ugly.

And then in patch 10 you move the bulk of the logic into calculate_vsid().

So instead can we:
- add a small helper that does the esid calculation, eg. calculate_esid() ?
- factor out the vsid logic into a helper, calculate_vsid() ?
- rework the spu code to use those, dropping __spu_trap_data_seg()
- use the helpers in the cxl code

cheers