[lkml]   [2020]   [Jan]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: [rfc] dma-mapping: preallocate unencrypted DMA atomic pool
On Mon, Jan 06, 2020 at 05:34:00PM +0000, Robin Murphy wrote:
> On 01/01/2020 1:54 am, David Rientjes via iommu wrote:
>> Christoph, Thomas, is something like this (without the diagnosic
>> information included in this patch) acceptable for these allocations?
>> Adding expansion support when the pool is half depleted wouldn't be *that*
>> hard.
>> Or are there alternatives we should consider? Thanks!
> Are there any platforms which require both non-cacheable remapping *and*
> unencrypted remapping for distinct subsets of devices?
> If not (and I'm assuming there aren't, because otherwise this patch is
> incomplete in covering only 2 of the 3 possible combinations), then
> couldn't we keep things simpler by just attributing both properties to the
> single "atomic pool" on the basis that one or the other will always be a
> no-op? In other words, basically just tweaking the existing "!coherent"
> tests to "!coherent || force_dma_unencrypted()" and doing
> set_dma_unencrypted() unconditionally in atomic_pool_init().

I think that would make most sense.

 \ /
  Last update: 2020-01-07 11:55    [W:0.139 / U:0.292 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site