linux-kernel - Re: [PATCH 12/16] iommu/amd: Add initialization routines for AMD interrupt remapping

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20121001080541.GM4009@amd.com>
Date:	Mon, 1 Oct 2012 10:05:41 +0200
From:	Joerg Roedel <joerg.roedel@....com>
To:	Shuah Khan <shuahkhan@...il.com>
CC:	<iommu@...ts.linux-foundation.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 12/16] iommu/amd: Add initialization routines for AMD
 interrupt remapping

On Fri, Sep 28, 2012 at 05:18:18PM -0600, Shuah Khan wrote:
> > +void amd_iommu_disable(void)
> > +{
> > +       amd_iommu_suspend();
> 
> Is it safe to attempt to suspend when iommu is in suspend state? In
> other words what happens if amd_iommu_disable() gets called when iommu
> is already in suspend state?

Yes, this is safe. It just trns a bit to 0 which is already 0.

>> > +int amd_iommu_reenable(int mode)
> > +{
> > +       amd_iommu_resume();
> 
> Same question as above. Safe to do a resume, when in resumed state?

Safe too, it just writes values to the hardware which are already there.
This was also proven by testing.


	Joerg

-- 
AMD Operating System Research Center

Advanced Micro Devices GmbH Einsteinring 24 85609 Dornach
General Managers: Alberto Bozzo
Registration: Dornach, Landkr. Muenchen; Registerger. Muenchen, HRB Nr. 43632

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/