From: Robin Murphy <robin.murphy@arm.com>
To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>,
Joerg Roedel <joro@8bytes.org>
Cc: "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>,
Linuxarm <linuxarm@huawei.com>,
"lorenzo.pieralisi@arm.com" <lorenzo.pieralisi@arm.com>,
wanghuiqiang <wanghuiqiang@huawei.com>,
"Guohanjun (Hanjun Guo)" <guohanjun@huawei.com>,
"steven.price@arm.com" <steven.price@arm.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>,
yangyicong <yangyicong@huawei.com>
Subject: Re: [PATCH v4 2/8] iommu/dma: Introduce generic helper to retrieve RMR info
Date: Wed, 19 May 2021 12:48:11 +0100 [thread overview]
Message-ID: <4047b1ef-5f6e-c3b8-e701-1cfa68acfd69@arm.com> (raw)
In-Reply-To: <503068eb5f184639a75d7d1ef929b4c6@huawei.com>
On 2021-05-19 10:30, Shameerali Kolothum Thodi wrote:
>
>
>> -----Original Message-----
>> From: Joerg Roedel [mailto:joro@8bytes.org]
>> Sent: 18 May 2021 09:50
>> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
>> Cc: linux-arm-kernel@lists.infradead.org; linux-acpi@vger.kernel.org;
>> iommu@lists.linux-foundation.org; Linuxarm <linuxarm@huawei.com>;
>> lorenzo.pieralisi@arm.com; robin.murphy@arm.com; wanghuiqiang
>> <wanghuiqiang@huawei.com>; Guohanjun (Hanjun Guo)
>> <guohanjun@huawei.com>; steven.price@arm.com; Sami.Mujawar@arm.com;
>> jon@solid-run.com; eric.auger@redhat.com; yangyicong
>> <yangyicong@huawei.com>
>> Subject: Re: [PATCH v4 2/8] iommu/dma: Introduce generic helper to retrieve
>> RMR info
>>
>> On Thu, May 13, 2021 at 02:45:44PM +0100, Shameer Kolothum wrote:
>>> +/**
>>> + * struct iommu_rmr - Reserved Memory Region details per IOMMU
>>> + * @list: Linked list pointers to hold RMR region info
>>> + * @base_address: base address of Reserved Memory Region
>>> + * @length: length of memory region
>>> + * @sid: associated stream id
>>> + * @flags: flags that apply to the RMR node
>>> + */
>>> +struct iommu_rmr {
>>> + struct list_head list;
>>> + phys_addr_t base_address;
>>> + u64 length;
>>> + u32 sid;
>>> + u32 flags;
>>> +};
>>> +
>>> +/* RMR Remap permitted */
>>> +#define IOMMU_RMR_REMAP_PERMITTED (1 << 0)
>>> +
>>
>> This struct has lots of overlap with 'struct iommu_resv_region'. Any
>> reason the existing struct can't be used here?
>>
>
> Hmm..main reason is "sid". RMRs are associated with stream ids and
> that is used to install bypass STEs/SMRs in SMMU drivers and also to check
> whether a dev has any RMR regions associated with it.
>
> I think we could add sid/dev_id to 'struct iommu_resv_region', and modify
> iommu_alloc_resv_region() accordingly. That can get rid of the above struct
> and iommu_dma_alloc_rmr() fn. Not sure this will complicate things as
> the dev_id is only valid for RMR reservation region cases.
>
> Please let me know your thoughts.
Maybe add a union for FW-specific data to struct resv_region, so that it
could eventually subsume AMD's struct unity_map_entry and Intel's struct
dmar_rmrr_unit as well? They're essentially doing the same dance.
We might still have to create copies of the firmware-allocated entries
to actually assign to domains (certainly where one entry covers multiple
devices), but kmemdup() is still a lot neater than various translations
from private formats.
Robin.
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2021-05-19 11:50 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-13 13:45 [PATCH v4 0/8] ACPI/IORT: Support for IORT RMR node Shameer Kolothum
2021-05-13 13:45 ` [PATCH v4 1/8] ACPI/IORT: Add support for RMR node parsing Shameer Kolothum
2021-06-03 11:36 ` Lorenzo Pieralisi
2021-06-03 11:48 ` Shameerali Kolothum Thodi
2021-05-13 13:45 ` [PATCH v4 2/8] iommu/dma: Introduce generic helper to retrieve RMR info Shameer Kolothum
2021-05-18 8:49 ` Joerg Roedel
2021-05-19 9:30 ` Shameerali Kolothum Thodi
2021-05-19 11:48 ` Robin Murphy [this message]
2021-05-13 13:45 ` [PATCH v4 3/8] ACPI/IORT: Add a helper to retrieve RMR memory regions Shameer Kolothum
2021-06-03 11:20 ` Lorenzo Pieralisi
2021-05-13 13:45 ` [PATCH v4 4/8] iommu/arm-smmu-v3: Introduce strtab init helper Shameer Kolothum
2021-05-13 13:45 ` [PATCH v4 5/8] iommu/arm-smmu-v3: Add bypass flag to arm_smmu_write_strtab_ent() Shameer Kolothum
2021-05-13 13:45 ` [PATCH v4 6/8] iommu/arm-smmu-v3: Get associated RMR info and install bypass STE Shameer Kolothum
2021-05-13 13:45 ` [PATCH v4 7/8] iommu/arm-smmu: Get associated RMR info and install bypass SMR Shameer Kolothum
2021-05-13 13:45 ` [PATCH v4 8/8] iommu/dma: Reserve any RMR regions associated with a dev Shameer Kolothum
2021-05-21 12:55 ` [PATCH v4 0/8] ACPI/IORT: Support for IORT RMR node Steven Price
2021-05-21 13:12 ` Shameerali Kolothum Thodi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4047b1ef-5f6e-c3b8-e701-1cfa68acfd69@arm.com \
--to=robin.murphy@arm.com \
--cc=Sami.Mujawar@arm.com \
--cc=eric.auger@redhat.com \
--cc=guohanjun@huawei.com \
--cc=iommu@lists.linux-foundation.org \
--cc=jon@solid-run.com \
--cc=joro@8bytes.org \
--cc=linux-acpi@vger.kernel.org \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linuxarm@huawei.com \
--cc=lorenzo.pieralisi@arm.com \
--cc=shameerali.kolothum.thodi@huawei.com \
--cc=steven.price@arm.com \
--cc=wanghuiqiang@huawei.com \
--cc=yangyicong@huawei.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).