[Intel-gfx] [RFCv5 2/2] drm/i915: Introduce private PAT management

[Wang, Zhi A]

Sure. I'm digging selftest now.

-----Original Message-----
From: Chris Wilson [mailto:chris at chris-wilson.co.uk] 
Sent: Tuesday, August 29, 2017 3:18 PM
To: Wang, Zhi A <zhi.a.wang at intel.com>; intel-gfx at lists.freedesktop.org; intel-gvt-dev at lists.freedesktop.org
Cc: joonas.lahtinen at linux.intel.com; zhenyuw at linux.intel.com; Wang, Zhi A <zhi.a.wang at intel.com>; Widawsky, Benjamin <benjamin.widawsky at intel.com>; Vivi, Rodrigo <rodrigo.vivi at intel.com>
Subject: Re: [RFCv5 2/2] drm/i915: Introduce private PAT management

Quoting Zhi Wang (2017-08-29 09:00:51)
> The private PAT management is to support PPAT entry manipulation. Two 
> APIs are introduced for dynamically managing PPAT entries: 
> intel_ppat_get and intel_ppat_put.
> 
> intel_ppat_get will search for an existing PPAT entry which perfectly 
> matches the required PPAT value. If not, it will try to allocate or 
> return a partially matched PPAT entry if there is any available PPAT 
> indexes or not.
> 
> intel_ppat_put will put back the PPAT entry which comes from 
> intel_ppat_get. If it's dynamically allocated, the reference count 
> will be decreased. If the reference count turns into zero, the PPAT 
> index is freed again.
> 
> Besides, another two callbacks are introduced to support the private 
> PAT management framework. One is ppat->update(), which writes the PPAT 
> configurations in ppat->entries into HW. Another one is ppat->match, 
> which will return a score to show how two PPAT values match with each other.

Oh and since you are exporting an interface, I bet you would appreciate it if we had some unittests in selftests/ ;) -Chris