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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.

WARNING: multiple messages have this Message-ID
From: Robin Murphy <robin.murphy@arm.com>
To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>,
	Joerg Roedel <joro@8bytes.org>
Cc: "jon@solid-run.com" <jon@solid-run.com>,
	Linuxarm <linuxarm@huawei.com>,
	"steven.price@arm.com" <steven.price@arm.com>,
	"linux-acpi@vger.kernel.org" <linux-acpi@vger.kernel.org>,
	"iommu@lists.linux-foundation.org"
	<iommu@lists.linux-foundation.org>,
	"linux-arm-kernel@lists.infradead.org"
	<linux-arm-kernel@lists.infradead.org>,
	"Guohanjun \(Hanjun Guo\)" <guohanjun@huawei.com>,
	yangyicong <yangyicong@huawei.com>,
	"Sami.Mujawar@arm.com" <Sami.Mujawar@arm.com>,
	wanghuiqiang <wanghuiqiang@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.
_______________________________________________
iommu mailing list
iommu@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/iommu

WARNING: multiple messages have this Message-ID
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

  reply	other threads:[~2021-05-19 11:48 UTC|newest]

Thread overview: 51+ 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 ` Shameer Kolothum
2021-05-13 13:45 ` Shameer Kolothum
2021-05-13 13:45 ` [PATCH v4 1/8] ACPI/IORT: Add support for RMR node parsing Shameer Kolothum
2021-05-13 13:45   ` Shameer Kolothum
2021-05-13 13:45   ` Shameer Kolothum
2021-06-03 11:36   ` Lorenzo Pieralisi
2021-06-03 11:36     ` Lorenzo Pieralisi
2021-06-03 11:36     ` Lorenzo Pieralisi
2021-06-03 11:48     ` Shameerali Kolothum Thodi
2021-06-03 11:48       ` Shameerali Kolothum Thodi
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
2021-05-13 13:45   ` Shameer Kolothum
2021-05-13 13:45   ` Shameer Kolothum
2021-05-18  8:49   ` Joerg Roedel
2021-05-18  8:49     ` Joerg Roedel
2021-05-18  8:49     ` Joerg Roedel
2021-05-19  9:30     ` Shameerali Kolothum Thodi
2021-05-19  9:30       ` Shameerali Kolothum Thodi
2021-05-19  9:30       ` Shameerali Kolothum Thodi
2021-05-19 11:48       ` Robin Murphy [this message]
2021-05-19 11:48         ` Robin Murphy
2021-05-19 11:48         ` Robin Murphy
2021-05-13 13:45 ` [PATCH v4 3/8] ACPI/IORT: Add a helper to retrieve RMR memory regions Shameer Kolothum
2021-05-13 13:45   ` Shameer Kolothum
2021-05-13 13:45   ` Shameer Kolothum
2021-06-03 11:20   ` Lorenzo Pieralisi
2021-06-03 11:20     ` Lorenzo Pieralisi
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   ` Shameer Kolothum
2021-05-13 13:45   ` 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   ` Shameer Kolothum
2021-05-13 13:45   ` 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   ` Shameer Kolothum
2021-05-13 13:45   ` 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   ` Shameer Kolothum
2021-05-13 13:45   ` Shameer Kolothum
2021-05-13 13:45 ` [PATCH v4 8/8] iommu/dma: Reserve any RMR regions associated with a dev Shameer Kolothum
2021-05-13 13:45   ` Shameer Kolothum
2021-05-13 13:45   ` Shameer Kolothum
2021-05-21 12:55 ` [PATCH v4 0/8] ACPI/IORT: Support for IORT RMR node Steven Price
2021-05-21 12:55   ` Steven Price
2021-05-21 12:55   ` Steven Price
2021-05-21 13:12   ` Shameerali Kolothum Thodi
2021-05-21 13:12     ` Shameerali Kolothum Thodi
2021-05-21 13:12     ` Shameerali Kolothum Thodi

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