From: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
To: Steven Price <steven.price@arm.com>,
"linux-arm-kernel@lists.infradead.org"
<linux-arm-kernel@lists.infradead.org>,
"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
"iommu@lists.linux-foundation.org"
<iommu@lists.linux-foundation.org>
Cc: Linuxarm <linuxarm@huawei.com>,
"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
"joro@8bytes.org" <joro@8bytes.org>,
"robin.murphy@arm.com" <robin.murphy@arm.com>,
"will@kernel.org" <will@kernel.org>,
wanghuiqiang <wanghuiqiang@huawei.com>,
"Guohanjun (Hanjun Guo)" <guohanjun@huawei.com>,
"Sami.Mujawar@arm.com" <Sami.Mujawar@arm.com>,
"jon@solid-run.com" <jon@solid-run.com>,
"eric.auger@redhat.com" <eric.auger@redhat.com>,
"laurentiu.tudor@nxp.com" <laurentiu.tudor@nxp.com>,
"hch@infradead.org" <hch@infradead.org>
Subject: RE: [PATCH v10 0/9] ACPI/IORT: Support for IORT RMR node
Date: Thu, 21 Apr 2022 14:43:09 +0000 [thread overview]
Message-ID: <78cd48d112b144b69bcc498748c584e3@huawei.com> (raw)
In-Reply-To: <b75dd20c-24b9-7944-bfb7-9f102623e725@arm.com>
> -----Original Message-----
> From: Steven Price [mailto:steven.price@arm.com]
> Sent: 21 April 2022 13:59
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;
> linux-arm-kernel@lists.infradead.org; linux-acpi@vger.kernel.org;
> iommu@lists.linux-foundation.org
> Cc: Linuxarm <linuxarm@huawei.com>; lorenzo.pieralisi@arm.com;
> joro@8bytes.org; robin.murphy@arm.com; will@kernel.org; wanghuiqiang
> <wanghuiqiang@huawei.com>; Guohanjun (Hanjun Guo)
> <guohanjun@huawei.com>; Sami.Mujawar@arm.com; jon@solid-run.com;
> eric.auger@redhat.com; laurentiu.tudor@nxp.com; hch@infradead.org
> Subject: Re: [PATCH v10 0/9] ACPI/IORT: Support for IORT RMR node
>
> On 20/04/2022 17:48, Shameer Kolothum wrote:
> > Hi
> >
> > v9 --> v10
> > - Dropped patch #1 ("Add temporary RMR node flag definitions") since
> > the ACPICA header updates patch is now in the mailing list[1]
> > - Based on the suggestion from Christoph, introduced a
> > resv_region_free_fw_data() callback in struct iommu_resv_region and
> > used that to free RMR specific memory allocations.
> >
> > Though there is a small change from v9 with respect to how we free up
> > the FW specific data, I have taken the liberty to pick up the R-by and
> > T-by tags from Lorenzo, Steve and Laurentiu. But please do take a look
> > again and let me know.
>
> I've given this a go and it works fine on my Juno setup. So do keep my
> T-by tag.
Many thanks for that.
> Sami has been kind enough to give me an updated firmware which also
> fixes the RMR node in the IORT. Although as mentioned before the details
> of the RMR node are currently being ignored so this doesn't change the
> functionality but silences the warning.
>
> My concern is that with the RMR region effectively ignored we may see
> more broken firmware, and while a length of zero produces a warning, an
> otherwise incorrect length will currently "silently work" but mean that
> any future tightening would cause problems. For example if the SMMU
> driver were to recreate the mappings to only cover the region specified
> in the RMR it may not be large enough if the RMR base/length are not
> correct.
Not sure how we can further validate the RMR if the firmware provides an
incorrect one. I see your point of future tightening causing problems
with broken firmware. But then it is indeed a "broken firmware"...
It's up to the maintainers as to whether they see this as a
> problem or not.
Hi Robin,
Any thoughts on this?
Thanks,
Shameer
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next prev parent reply other threads:[~2022-04-21 14:44 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-20 16:48 [PATCH v10 0/9] ACPI/IORT: Support for IORT RMR node Shameer Kolothum
2022-04-20 16:48 ` [PATCH v10 1/9] iommu: Introduce a union to struct iommu_resv_region Shameer Kolothum
2022-04-21 6:46 ` Christoph Hellwig
2022-04-20 16:48 ` [PATCH v10 2/9] ACPI/IORT: Make iort_iommu_msi_get_resv_regions() return void Shameer Kolothum
2022-04-21 6:44 ` Christoph Hellwig
2022-04-20 16:48 ` [PATCH v10 3/9] ACPI/IORT: Provide a generic helper to retrieve reserve regions Shameer Kolothum
2022-04-21 6:44 ` Christoph Hellwig
2022-04-20 16:48 ` [PATCH v10 4/9] ACPI/IORT: Add support to retrieve IORT RMR reserved regions Shameer Kolothum
2022-04-21 6:48 ` Christoph Hellwig
2022-04-21 14:50 ` Shameerali Kolothum Thodi
2022-04-20 16:48 ` [PATCH v10 5/9] ACPI/IORT: Add a helper to retrieve RMR info directly Shameer Kolothum
2022-04-20 16:48 ` [PATCH v10 6/9] iommu/arm-smmu-v3: Introduce strtab init helper Shameer Kolothum
2022-04-20 16:48 ` [PATCH v10 7/9] iommu/arm-smmu-v3: Refactor arm_smmu_init_bypass_stes() to force bypass Shameer Kolothum
2022-04-20 16:48 ` [PATCH v10 8/9] iommu/arm-smmu-v3: Get associated RMR info and install bypass STE Shameer Kolothum
2022-04-20 16:48 ` [PATCH v10 9/9] iommu/arm-smmu: Get associated RMR info and install bypass SMR Shameer Kolothum
2022-04-21 12:58 ` [PATCH v10 0/9] ACPI/IORT: Support for IORT RMR node Steven Price
2022-04-21 14:43 ` Shameerali Kolothum Thodi [this message]
2022-04-21 15:45 ` Robin Murphy
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