lkml.org 
[lkml]   [2018]   [Apr]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH v4 05/22] iommu: introduce iommu invalidate API function
Date
> From: Jean-Philippe Brucker [mailto:jean-philippe.brucker@arm.com]
> Sent: Saturday, April 28, 2018 2:08 AM
>
> [...]
> >> If this corresponds to QI_GRAN_ALL_ALL in patch 9, the comment should
> >> be "Cache of all PASIDs"? Or maybe "all entries for all PASIDs"? Is it
> >> different from GRANU_DOMAIN then?
> > QI_GRAN_ALL_ALL maps to VT-d spec 6.5.2.4, which invalidates all ext
> > TLB cache within a domain. It could reuse GRANU_DOMAIN but I was
> > also trying to match the naming convention in the spec.
>
> Sorry I don't quite understand the difference between TLB and ext TLB
> invalidation. Can an ext TLB invalidation do everything a TLB can do
> plus some additional parameters (introduced in more recent version of
> the spec), or do they have distinct purposes? I'm trying to understand
> why it needs to be user-visible

distinct purpose though some overlapped effect:

IOTLB invalidate is more for 2nd-level cache on granularity (global/
domain/PSI), with side effect on 1st-level and nested caches (global/
domain).

Extended IOTLB invalidate is specifically for 1st-level and nested
caches on granularity (per-domain: all PASIDs/per PASID/PSI).

Thanks
Kevin
\
 
 \ /
  Last update: 2018-04-28 04:41    [W:1.892 / U:0.168 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site