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[v8,00/11] ACPI/IORT: Support for IORT RMR node

Message ID 20220221154344.2126-1-shameerali.kolothum.thodi@huawei.com (mailing list archive)
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Series ACPI/IORT: Support for IORT RMR node | expand

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Shameerali Kolothum Thodi Feb. 21, 2022, 3:43 p.m. UTC
Hi,

Since we now have an updated verion[0] of IORT spec(E.d) which
addresses the memory attributes issues discussed here [1],
this series now make use of it.

The pull request for ACPICA E.d related changes are already
raised and can be found here,
https://github.com/acpica/acpica/pull/752

v7 --> v8
  - Patch #1 has temp definitions for RMR related changes till
    the ACPICA header changes are part of kernel.
  - No early parsing of RMR node info and is only parsed at the
    time of use.
  - Changes to the RMR get/put API format compared to the
    previous version.
  - Support for RMR descriptor shared by multiple stream IDs.

Please take a look and let me know your thoughts.

Thanks,
Shameer
[0] https://developer.arm.com/documentation/den0049/ed/
[1] https://lore.kernel.org/linux-acpi/20210805160319.GB23085@lpieralisi/

From old:
We have faced issues with 3408iMR RAID controller cards which
fail to boot when SMMU is enabled. This is because these
controllers make use of host memory for various caching related
purposes and when SMMU is enabled the iMR firmware fails to
access these memory regions as there is no mapping for them.
IORT RMR provides a way for UEFI to describe and report these
memory regions so that the kernel can make a unity mapping for
these in SMMU.

Change History:

v6 --> v7
 -fix pointed out by Steve to the SMMUv2 SMR bypass install in patch #8.

v5 --> v6
- Addressed comments from Robin & Lorenzo.
  : Moved iort_parse_rmr() to acpi_iort_init() from
    iort_init_platform_devices().
  : Removed use of struct iort_rmr_entry during the initial
    parse. Using struct iommu_resv_region instead.
  : Report RMR address alignment and overlap errors, but continue.
  : Reworked arm_smmu_init_bypass_stes() (patch # 6).
- Updated SMMUv2 bypass SMR code. Thanks to Jon N (patch #8).
- Set IOMMU protection flags(IOMMU_CACHE, IOMMU_MMIO) based
  on Type of RMR region. Suggested by Jon N.

v4 --> v5
 -Added a fw_data union to struct iommu_resv_region and removed
  struct iommu_rmr (Based on comments from Joerg/Robin).
 -Added iommu_put_rmrs() to release mem.
 -Thanks to Steve for verifying on SMMUv2, but not added the Tested-by
  yet because of the above changes.

v3 -->v4
-Included the SMMUv2 SMR bypass install changes suggested by
 Steve(patch #7)
-As per Robin's comments, RMR reserve implementation is now
 more generic  (patch #8) and dropped v3 patches 8 and 10.
-Rebase to 5.13-rc1

RFC v2 --> v3
 -Dropped RFC tag as the ACPICA header changes are now ready to be
  part of 5.13[0]. But this series still has a dependency on that patch.
 -Added IORT E.b related changes(node flags, _DSM function 5 checks for
  PCIe).
 -Changed RMR to stream id mapping from M:N to M:1 as per the spec and
  discussion here[1].
 -Last two patches add support for SMMUv2(Thanks to Jon Nettleton!)

Jon Nettleton (1):
  iommu/arm-smmu: Get associated RMR info and install bypass SMR

Shameer Kolothum (10):
  ACPI/IORT: Add temporary RMR node flag definitions
  iommu: Introduce a union to struct iommu_resv_region
  ACPI/IORT: Add helper functions to parse RMR nodes
  iommu/dma: Introduce generic helper to retrieve RMR info
  ACPI/IORT: Add a helper to retrieve RMR memory regions
  iommu/arm-smmu-v3: Introduce strtab init helper
  iommu/arm-smmu-v3: Refactor arm_smmu_init_bypass_stes() to force
    bypass
  iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
  iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev
  iommu/arm-smmu: Reserve any RMR regions associated with a dev

 drivers/acpi/arm64/iort.c                   | 305 ++++++++++++++++++++
 drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  91 ++++--
 drivers/iommu/arm/arm-smmu/arm-smmu.c       |  65 ++++-
 drivers/iommu/dma-iommu.c                   |  25 ++
 include/linux/acpi_iort.h                   |  14 +
 include/linux/dma-iommu.h                   |  14 +
 include/linux/iommu.h                       |   9 +
 7 files changed, 504 insertions(+), 19 deletions(-)

Comments

Steven Price March 3, 2022, 10:37 a.m. UTC | #1
On 21/02/2022 15:43, Shameer Kolothum wrote:
> Hi,
> 
> Since we now have an updated verion[0] of IORT spec(E.d) which
> addresses the memory attributes issues discussed here [1],
> this series now make use of it.
> 
> The pull request for ACPICA E.d related changes are already
> raised and can be found here,
> https://github.com/acpica/acpica/pull/752
> 
> v7 --> v8
>   - Patch #1 has temp definitions for RMR related changes till
>     the ACPICA header changes are part of kernel.
>   - No early parsing of RMR node info and is only parsed at the
>     time of use.
>   - Changes to the RMR get/put API format compared to the
>     previous version.
>   - Support for RMR descriptor shared by multiple stream IDs.
> 
> Please take a look and let me know your thoughts.

Hi Shameer,

I've now been able to test this on the Juno platform with a modified
firmware supporting the newer spec (thanks Sami!). Everything works, so
feel free to add my:

Tested-by: Steven Price <steven.price@arm.com>

(Note that I haven't tested the smmu-v3 support)

Thanks,

Steve

> Thanks,
> Shameer
> [0] https://developer.arm.com/documentation/den0049/ed/
> [1] https://lore.kernel.org/linux-acpi/20210805160319.GB23085@lpieralisi/
> 
> From old:
> We have faced issues with 3408iMR RAID controller cards which
> fail to boot when SMMU is enabled. This is because these
> controllers make use of host memory for various caching related
> purposes and when SMMU is enabled the iMR firmware fails to
> access these memory regions as there is no mapping for them.
> IORT RMR provides a way for UEFI to describe and report these
> memory regions so that the kernel can make a unity mapping for
> these in SMMU.
> 
> Change History:
> 
> v6 --> v7
>  -fix pointed out by Steve to the SMMUv2 SMR bypass install in patch #8.
> 
> v5 --> v6
> - Addressed comments from Robin & Lorenzo.
>   : Moved iort_parse_rmr() to acpi_iort_init() from
>     iort_init_platform_devices().
>   : Removed use of struct iort_rmr_entry during the initial
>     parse. Using struct iommu_resv_region instead.
>   : Report RMR address alignment and overlap errors, but continue.
>   : Reworked arm_smmu_init_bypass_stes() (patch # 6).
> - Updated SMMUv2 bypass SMR code. Thanks to Jon N (patch #8).
> - Set IOMMU protection flags(IOMMU_CACHE, IOMMU_MMIO) based
>   on Type of RMR region. Suggested by Jon N.
> 
> v4 --> v5
>  -Added a fw_data union to struct iommu_resv_region and removed
>   struct iommu_rmr (Based on comments from Joerg/Robin).
>  -Added iommu_put_rmrs() to release mem.
>  -Thanks to Steve for verifying on SMMUv2, but not added the Tested-by
>   yet because of the above changes.
> 
> v3 -->v4
> -Included the SMMUv2 SMR bypass install changes suggested by
>  Steve(patch #7)
> -As per Robin's comments, RMR reserve implementation is now
>  more generic  (patch #8) and dropped v3 patches 8 and 10.
> -Rebase to 5.13-rc1
> 
> RFC v2 --> v3
>  -Dropped RFC tag as the ACPICA header changes are now ready to be
>   part of 5.13[0]. But this series still has a dependency on that patch.
>  -Added IORT E.b related changes(node flags, _DSM function 5 checks for
>   PCIe).
>  -Changed RMR to stream id mapping from M:N to M:1 as per the spec and
>   discussion here[1].
>  -Last two patches add support for SMMUv2(Thanks to Jon Nettleton!)
> 
> Jon Nettleton (1):
>   iommu/arm-smmu: Get associated RMR info and install bypass SMR
> 
> Shameer Kolothum (10):
>   ACPI/IORT: Add temporary RMR node flag definitions
>   iommu: Introduce a union to struct iommu_resv_region
>   ACPI/IORT: Add helper functions to parse RMR nodes
>   iommu/dma: Introduce generic helper to retrieve RMR info
>   ACPI/IORT: Add a helper to retrieve RMR memory regions
>   iommu/arm-smmu-v3: Introduce strtab init helper
>   iommu/arm-smmu-v3: Refactor arm_smmu_init_bypass_stes() to force
>     bypass
>   iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
>   iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev
>   iommu/arm-smmu: Reserve any RMR regions associated with a dev
> 
>  drivers/acpi/arm64/iort.c                   | 305 ++++++++++++++++++++
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  91 ++++--
>  drivers/iommu/arm/arm-smmu/arm-smmu.c       |  65 ++++-
>  drivers/iommu/dma-iommu.c                   |  25 ++
>  include/linux/acpi_iort.h                   |  14 +
>  include/linux/dma-iommu.h                   |  14 +
>  include/linux/iommu.h                       |   9 +
>  7 files changed, 504 insertions(+), 19 deletions(-)
>
Shameerali Kolothum Thodi March 3, 2022, 1:02 p.m. UTC | #2
> -----Original Message-----
> From: Steven Price [mailto:steven.price@arm.com]
> Sent: 03 March 2022 10:38
> 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; yangyicong <yangyicong@huawei.com>
> Subject: Re: [PATCH v8 00/11] ACPI/IORT: Support for IORT RMR node
> 
> On 21/02/2022 15:43, Shameer Kolothum wrote:
> > Hi,
> >
> > Since we now have an updated verion[0] of IORT spec(E.d) which
> > addresses the memory attributes issues discussed here [1],
> > this series now make use of it.
> >
> > The pull request for ACPICA E.d related changes are already
> > raised and can be found here,
> > https://github.com/acpica/acpica/pull/752
> >
> > v7 --> v8
> >   - Patch #1 has temp definitions for RMR related changes till
> >     the ACPICA header changes are part of kernel.
> >   - No early parsing of RMR node info and is only parsed at the
> >     time of use.
> >   - Changes to the RMR get/put API format compared to the
> >     previous version.
> >   - Support for RMR descriptor shared by multiple stream IDs.
> >
> > Please take a look and let me know your thoughts.
> 
> Hi Shameer,
> 
> I've now been able to test this on the Juno platform with a modified
> firmware supporting the newer spec (thanks Sami!). Everything works, so
> feel free to add my:
> 
> Tested-by: Steven Price <steven.price@arm.com>
> 
> (Note that I haven't tested the smmu-v3 support)

Thanks Steve, for giving it a spin and verifying.

Cheers,
Shameer
Eric Auger March 11, 2022, 8:06 a.m. UTC | #3
Hi Shameer,

On 2/21/22 4:43 PM, Shameer Kolothum wrote:
> Hi,
>
> Since we now have an updated verion[0] of IORT spec(E.d) which
> addresses the memory attributes issues discussed here [1],
> this series now make use of it.
>
> The pull request for ACPICA E.d related changes are already
> raised and can be found here,
> https://github.com/acpica/acpica/pull/752
>
> v7 --> v8
>   - Patch #1 has temp definitions for RMR related changes till
>     the ACPICA header changes are part of kernel.
>   - No early parsing of RMR node info and is only parsed at the
>     time of use.
>   - Changes to the RMR get/put API format compared to the
>     previous version.
>   - Support for RMR descriptor shared by multiple stream IDs.

I tested it on guest side for host MSI SW RESV region flat mapping
(using both the old single mapping layout and the now allowed multiple
RID ID mapping format) and this worked for me. Feel free to add my

Tested-by: Eric Auger <eric.auger@redhat.com>

Thanks

Eric


>
> Please take a look and let me know your thoughts.
>
> Thanks,
> Shameer
> [0] https://developer.arm.com/documentation/den0049/ed/
> [1] https://lore.kernel.org/linux-acpi/20210805160319.GB23085@lpieralisi/
>
> From old:
> We have faced issues with 3408iMR RAID controller cards which
> fail to boot when SMMU is enabled. This is because these
> controllers make use of host memory for various caching related
> purposes and when SMMU is enabled the iMR firmware fails to
> access these memory regions as there is no mapping for them.
> IORT RMR provides a way for UEFI to describe and report these
> memory regions so that the kernel can make a unity mapping for
> these in SMMU.
>
> Change History:
>
> v6 --> v7
>  -fix pointed out by Steve to the SMMUv2 SMR bypass install in patch #8.
>
> v5 --> v6
> - Addressed comments from Robin & Lorenzo.
>   : Moved iort_parse_rmr() to acpi_iort_init() from
>     iort_init_platform_devices().
>   : Removed use of struct iort_rmr_entry during the initial
>     parse. Using struct iommu_resv_region instead.
>   : Report RMR address alignment and overlap errors, but continue.
>   : Reworked arm_smmu_init_bypass_stes() (patch # 6).
> - Updated SMMUv2 bypass SMR code. Thanks to Jon N (patch #8).
> - Set IOMMU protection flags(IOMMU_CACHE, IOMMU_MMIO) based
>   on Type of RMR region. Suggested by Jon N.
>
> v4 --> v5
>  -Added a fw_data union to struct iommu_resv_region and removed
>   struct iommu_rmr (Based on comments from Joerg/Robin).
>  -Added iommu_put_rmrs() to release mem.
>  -Thanks to Steve for verifying on SMMUv2, but not added the Tested-by
>   yet because of the above changes.
>
> v3 -->v4
> -Included the SMMUv2 SMR bypass install changes suggested by
>  Steve(patch #7)
> -As per Robin's comments, RMR reserve implementation is now
>  more generic  (patch #8) and dropped v3 patches 8 and 10.
> -Rebase to 5.13-rc1
>
> RFC v2 --> v3
>  -Dropped RFC tag as the ACPICA header changes are now ready to be
>   part of 5.13[0]. But this series still has a dependency on that patch.
>  -Added IORT E.b related changes(node flags, _DSM function 5 checks for
>   PCIe).
>  -Changed RMR to stream id mapping from M:N to M:1 as per the spec and
>   discussion here[1].
>  -Last two patches add support for SMMUv2(Thanks to Jon Nettleton!)
>
> Jon Nettleton (1):
>   iommu/arm-smmu: Get associated RMR info and install bypass SMR
>
> Shameer Kolothum (10):
>   ACPI/IORT: Add temporary RMR node flag definitions
>   iommu: Introduce a union to struct iommu_resv_region
>   ACPI/IORT: Add helper functions to parse RMR nodes
>   iommu/dma: Introduce generic helper to retrieve RMR info
>   ACPI/IORT: Add a helper to retrieve RMR memory regions
>   iommu/arm-smmu-v3: Introduce strtab init helper
>   iommu/arm-smmu-v3: Refactor arm_smmu_init_bypass_stes() to force
>     bypass
>   iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
>   iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev
>   iommu/arm-smmu: Reserve any RMR regions associated with a dev
>
>  drivers/acpi/arm64/iort.c                   | 305 ++++++++++++++++++++
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  91 ++++--
>  drivers/iommu/arm/arm-smmu/arm-smmu.c       |  65 ++++-
>  drivers/iommu/dma-iommu.c                   |  25 ++
>  include/linux/acpi_iort.h                   |  14 +
>  include/linux/dma-iommu.h                   |  14 +
>  include/linux/iommu.h                       |   9 +
>  7 files changed, 504 insertions(+), 19 deletions(-)
>
Eric Auger March 11, 2022, 8:19 a.m. UTC | #4
Hi guys,

On 2/21/22 4:43 PM, Shameer Kolothum wrote:
> Hi,
>
> Since we now have an updated verion[0] of IORT spec(E.d) which
> addresses the memory attributes issues discussed here [1],
> this series now make use of it.
>
> The pull request for ACPICA E.d related changes are already
> raised and can be found here,
> https://github.com/acpica/acpica/pull/752
>
> v7 --> v8
>   - Patch #1 has temp definitions for RMR related changes till
>     the ACPICA header changes are part of kernel.
>   - No early parsing of RMR node info and is only parsed at the
>     time of use.
>   - Changes to the RMR get/put API format compared to the
>     previous version.
>   - Support for RMR descriptor shared by multiple stream IDs.
>
> Please take a look and let me know your thoughts.
>
> Thanks,
> Shameer
> [0] https://developer.arm.com/documentation/den0049/ed/
I still have a question on the IORT E.d spec (unrelated to this series).

The spec mandates that if RMR nodes are presented in the IORT,
_DSM function #5 for the PCIe host bridge ACPI device object must return
0, indicating the OS must honour the PCI config that the FW computed at
boot time.

However implementing this _DSM #5 as above is known to prevent PCI
devices with IO ports from working, on aarch64 linux.

"
The reason is that EFI creates I/O port mappings below
    0x1000 (in fact, at 0). However Linux, for legacy reasons, does not
    support I/O ports <= 0x1000 on PCI, so the I/O assignment created by EFI
    is rejected.
   
    EFI creates the mappings primarily for itself, and up until DSM #5
    started to be enforced, all PCI resource allocations that existed at
    boot were ignored by Linux and recreated from scratch.
"

This is an excerpt of a qemu commit message that reverted the _DMS #5
change (Revert "acpi/gpex: Inform os to keep firmware resource map").
Has the situation changed since July 2021 (ie. has UEFI been reworked?).
[+ Ard]

Thank you in advance

Regards

Eric




> [1] https://lore.kernel.org/linux-acpi/20210805160319.GB23085@lpieralisi/
>
> From old:
> We have faced issues with 3408iMR RAID controller cards which
> fail to boot when SMMU is enabled. This is because these
> controllers make use of host memory for various caching related
> purposes and when SMMU is enabled the iMR firmware fails to
> access these memory regions as there is no mapping for them.
> IORT RMR provides a way for UEFI to describe and report these
> memory regions so that the kernel can make a unity mapping for
> these in SMMU.
>
> Change History:
>
> v6 --> v7
>  -fix pointed out by Steve to the SMMUv2 SMR bypass install in patch #8.
>
> v5 --> v6
> - Addressed comments from Robin & Lorenzo.
>   : Moved iort_parse_rmr() to acpi_iort_init() from
>     iort_init_platform_devices().
>   : Removed use of struct iort_rmr_entry during the initial
>     parse. Using struct iommu_resv_region instead.
>   : Report RMR address alignment and overlap errors, but continue.
>   : Reworked arm_smmu_init_bypass_stes() (patch # 6).
> - Updated SMMUv2 bypass SMR code. Thanks to Jon N (patch #8).
> - Set IOMMU protection flags(IOMMU_CACHE, IOMMU_MMIO) based
>   on Type of RMR region. Suggested by Jon N.
>
> v4 --> v5
>  -Added a fw_data union to struct iommu_resv_region and removed
>   struct iommu_rmr (Based on comments from Joerg/Robin).
>  -Added iommu_put_rmrs() to release mem.
>  -Thanks to Steve for verifying on SMMUv2, but not added the Tested-by
>   yet because of the above changes.
>
> v3 -->v4
> -Included the SMMUv2 SMR bypass install changes suggested by
>  Steve(patch #7)
> -As per Robin's comments, RMR reserve implementation is now
>  more generic  (patch #8) and dropped v3 patches 8 and 10.
> -Rebase to 5.13-rc1
>
> RFC v2 --> v3
>  -Dropped RFC tag as the ACPICA header changes are now ready to be
>   part of 5.13[0]. But this series still has a dependency on that patch.
>  -Added IORT E.b related changes(node flags, _DSM function 5 checks for
>   PCIe).
>  -Changed RMR to stream id mapping from M:N to M:1 as per the spec and
>   discussion here[1].
>  -Last two patches add support for SMMUv2(Thanks to Jon Nettleton!)
>
> Jon Nettleton (1):
>   iommu/arm-smmu: Get associated RMR info and install bypass SMR
>
> Shameer Kolothum (10):
>   ACPI/IORT: Add temporary RMR node flag definitions
>   iommu: Introduce a union to struct iommu_resv_region
>   ACPI/IORT: Add helper functions to parse RMR nodes
>   iommu/dma: Introduce generic helper to retrieve RMR info
>   ACPI/IORT: Add a helper to retrieve RMR memory regions
>   iommu/arm-smmu-v3: Introduce strtab init helper
>   iommu/arm-smmu-v3: Refactor arm_smmu_init_bypass_stes() to force
>     bypass
>   iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
>   iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev
>   iommu/arm-smmu: Reserve any RMR regions associated with a dev
>
>  drivers/acpi/arm64/iort.c                   | 305 ++++++++++++++++++++
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  91 ++++--
>  drivers/iommu/arm/arm-smmu/arm-smmu.c       |  65 ++++-
>  drivers/iommu/dma-iommu.c                   |  25 ++
>  include/linux/acpi_iort.h                   |  14 +
>  include/linux/dma-iommu.h                   |  14 +
>  include/linux/iommu.h                       |   9 +
>  7 files changed, 504 insertions(+), 19 deletions(-)
>
Robin Murphy March 11, 2022, 10:34 a.m. UTC | #5
On 2022-03-11 08:19, Eric Auger wrote:
> Hi guys,
> 
> On 2/21/22 4:43 PM, Shameer Kolothum wrote:
>> Hi,
>>
>> Since we now have an updated verion[0] of IORT spec(E.d) which
>> addresses the memory attributes issues discussed here [1],
>> this series now make use of it.
>>
>> The pull request for ACPICA E.d related changes are already
>> raised and can be found here,
>> https://github.com/acpica/acpica/pull/752
>>
>> v7 --> v8
>>    - Patch #1 has temp definitions for RMR related changes till
>>      the ACPICA header changes are part of kernel.
>>    - No early parsing of RMR node info and is only parsed at the
>>      time of use.
>>    - Changes to the RMR get/put API format compared to the
>>      previous version.
>>    - Support for RMR descriptor shared by multiple stream IDs.
>>
>> Please take a look and let me know your thoughts.
>>
>> Thanks,
>> Shameer
>> [0] https://developer.arm.com/documentation/den0049/ed/
> I still have a question on the IORT E.d spec (unrelated to this series).
> 
> The spec mandates that if RMR nodes are presented in the IORT,
> _DSM function #5 for the PCIe host bridge ACPI device object must return
> 0, indicating the OS must honour the PCI config that the FW computed at
> boot time.
> 
> However implementing this _DSM #5 as above is known to prevent PCI
> devices with IO ports from working, on aarch64 linux.
> 
> "
> The reason is that EFI creates I/O port mappings below
>      0x1000 (in fact, at 0). However Linux, for legacy reasons, does not
>      support I/O ports <= 0x1000 on PCI, so the I/O assignment created by EFI
>      is rejected.
>     
>      EFI creates the mappings primarily for itself, and up until DSM #5
>      started to be enforced, all PCI resource allocations that existed at
>      boot were ignored by Linux and recreated from scratch.
> "
> 
> This is an excerpt of a qemu commit message that reverted the _DMS #5
> change (Revert "acpi/gpex: Inform os to keep firmware resource map").
> Has the situation changed since July 2021 (ie. has UEFI been reworked?).
> [+ Ard]

FWIW I wasn't aware of that, but if it's an issue then it will need to 
be fixed in Linux or UEFI's PCI resource code (arguably if UEFI has 
already allocated from the bottom of I/O space then Linux should be safe 
to assume that there are no legacy PC I/O resources to worry about). The 
DSM is required to prevent bus numbers being reassigned, because if that 
happens then any PCI StreamIDs referenced in IORT may suddenly become 
meaningless and the association of root complex nodes and RMRs to 
physical hardware lost.

Robin.

> Thank you in advance
> 
> Regards
> 
> Eric
> 
> 
> 
> 
>> [1] https://lore.kernel.org/linux-acpi/20210805160319.GB23085@lpieralisi/
>>
>>  From old:
>> We have faced issues with 3408iMR RAID controller cards which
>> fail to boot when SMMU is enabled. This is because these
>> controllers make use of host memory for various caching related
>> purposes and when SMMU is enabled the iMR firmware fails to
>> access these memory regions as there is no mapping for them.
>> IORT RMR provides a way for UEFI to describe and report these
>> memory regions so that the kernel can make a unity mapping for
>> these in SMMU.
>>
>> Change History:
>>
>> v6 --> v7
>>   -fix pointed out by Steve to the SMMUv2 SMR bypass install in patch #8.
>>
>> v5 --> v6
>> - Addressed comments from Robin & Lorenzo.
>>    : Moved iort_parse_rmr() to acpi_iort_init() from
>>      iort_init_platform_devices().
>>    : Removed use of struct iort_rmr_entry during the initial
>>      parse. Using struct iommu_resv_region instead.
>>    : Report RMR address alignment and overlap errors, but continue.
>>    : Reworked arm_smmu_init_bypass_stes() (patch # 6).
>> - Updated SMMUv2 bypass SMR code. Thanks to Jon N (patch #8).
>> - Set IOMMU protection flags(IOMMU_CACHE, IOMMU_MMIO) based
>>    on Type of RMR region. Suggested by Jon N.
>>
>> v4 --> v5
>>   -Added a fw_data union to struct iommu_resv_region and removed
>>    struct iommu_rmr (Based on comments from Joerg/Robin).
>>   -Added iommu_put_rmrs() to release mem.
>>   -Thanks to Steve for verifying on SMMUv2, but not added the Tested-by
>>    yet because of the above changes.
>>
>> v3 -->v4
>> -Included the SMMUv2 SMR bypass install changes suggested by
>>   Steve(patch #7)
>> -As per Robin's comments, RMR reserve implementation is now
>>   more generic  (patch #8) and dropped v3 patches 8 and 10.
>> -Rebase to 5.13-rc1
>>
>> RFC v2 --> v3
>>   -Dropped RFC tag as the ACPICA header changes are now ready to be
>>    part of 5.13[0]. But this series still has a dependency on that patch.
>>   -Added IORT E.b related changes(node flags, _DSM function 5 checks for
>>    PCIe).
>>   -Changed RMR to stream id mapping from M:N to M:1 as per the spec and
>>    discussion here[1].
>>   -Last two patches add support for SMMUv2(Thanks to Jon Nettleton!)
>>
>> Jon Nettleton (1):
>>    iommu/arm-smmu: Get associated RMR info and install bypass SMR
>>
>> Shameer Kolothum (10):
>>    ACPI/IORT: Add temporary RMR node flag definitions
>>    iommu: Introduce a union to struct iommu_resv_region
>>    ACPI/IORT: Add helper functions to parse RMR nodes
>>    iommu/dma: Introduce generic helper to retrieve RMR info
>>    ACPI/IORT: Add a helper to retrieve RMR memory regions
>>    iommu/arm-smmu-v3: Introduce strtab init helper
>>    iommu/arm-smmu-v3: Refactor arm_smmu_init_bypass_stes() to force
>>      bypass
>>    iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
>>    iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev
>>    iommu/arm-smmu: Reserve any RMR regions associated with a dev
>>
>>   drivers/acpi/arm64/iort.c                   | 305 ++++++++++++++++++++
>>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  91 ++++--
>>   drivers/iommu/arm/arm-smmu/arm-smmu.c       |  65 ++++-
>>   drivers/iommu/dma-iommu.c                   |  25 ++
>>   include/linux/acpi_iort.h                   |  14 +
>>   include/linux/dma-iommu.h                   |  14 +
>>   include/linux/iommu.h                       |   9 +
>>   7 files changed, 504 insertions(+), 19 deletions(-)
>>
>
Shameerali Kolothum Thodi March 11, 2022, 1:23 p.m. UTC | #6
> -----Original Message-----
> From: Eric Auger [mailto:eric.auger@redhat.com]
> Sent: 11 March 2022 08:07
> 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>; steven.price@arm.com; Sami.Mujawar@arm.com;
> jon@solid-run.com; yangyicong <yangyicong@huawei.com>
> Subject: Re: [PATCH v8 00/11] ACPI/IORT: Support for IORT RMR node
> 
> Hi Shameer,
> 
> On 2/21/22 4:43 PM, Shameer Kolothum wrote:
> > Hi,
> >
> > Since we now have an updated verion[0] of IORT spec(E.d) which
> > addresses the memory attributes issues discussed here [1],
> > this series now make use of it.
> >
> > The pull request for ACPICA E.d related changes are already
> > raised and can be found here,
> > https://github.com/acpica/acpica/pull/752
> >
> > v7 --> v8
> >   - Patch #1 has temp definitions for RMR related changes till
> >     the ACPICA header changes are part of kernel.
> >   - No early parsing of RMR node info and is only parsed at the
> >     time of use.
> >   - Changes to the RMR get/put API format compared to the
> >     previous version.
> >   - Support for RMR descriptor shared by multiple stream IDs.
> 
> I tested it on guest side for host MSI SW RESV region flat mapping
> (using both the old single mapping layout and the now allowed multiple
> RID ID mapping format) and this worked for me. Feel free to add my
> 
> Tested-by: Eric Auger <eric.auger@redhat.com>

Thanks Eric for verifying this, especially the multiple RID mapping case.

Cheers,
Shameer
Eric Auger March 14, 2022, 10:37 a.m. UTC | #7
Hi Robin

On 3/11/22 11:34 AM, Robin Murphy wrote:
> On 2022-03-11 08:19, Eric Auger wrote:
>> Hi guys,
>>
>> On 2/21/22 4:43 PM, Shameer Kolothum wrote:
>>> Hi,
>>>
>>> Since we now have an updated verion[0] of IORT spec(E.d) which
>>> addresses the memory attributes issues discussed here [1],
>>> this series now make use of it.
>>>
>>> The pull request for ACPICA E.d related changes are already
>>> raised and can be found here,
>>> https://github.com/acpica/acpica/pull/752
>>>
>>> v7 --> v8
>>>    - Patch #1 has temp definitions for RMR related changes till
>>>      the ACPICA header changes are part of kernel.
>>>    - No early parsing of RMR node info and is only parsed at the
>>>      time of use.
>>>    - Changes to the RMR get/put API format compared to the
>>>      previous version.
>>>    - Support for RMR descriptor shared by multiple stream IDs.
>>>
>>> Please take a look and let me know your thoughts.
>>>
>>> Thanks,
>>> Shameer
>>> [0] https://developer.arm.com/documentation/den0049/ed/
>> I still have a question on the IORT E.d spec (unrelated to this series).
>>
>> The spec mandates that if RMR nodes are presented in the IORT,
>> _DSM function #5 for the PCIe host bridge ACPI device object must return
>> 0, indicating the OS must honour the PCI config that the FW computed at
>> boot time.
>>
>> However implementing this _DSM #5 as above is known to prevent PCI
>> devices with IO ports from working, on aarch64 linux.
>>
>> "
>> The reason is that EFI creates I/O port mappings below
>>      0x1000 (in fact, at 0). However Linux, for legacy reasons, does not
>>      support I/O ports <= 0x1000 on PCI, so the I/O assignment
>> created by EFI
>>      is rejected.
>>          EFI creates the mappings primarily for itself, and up until
>> DSM #5
>>      started to be enforced, all PCI resource allocations that
>> existed at
>>      boot were ignored by Linux and recreated from scratch.
>> "
>>
>> This is an excerpt of a qemu commit message that reverted the _DMS #5
>> change (Revert "acpi/gpex: Inform os to keep firmware resource map").
>> Has the situation changed since July 2021 (ie. has UEFI been reworked?).
>> [+ Ard]
>
> FWIW I wasn't aware of that, but if it's an issue then it will need to
> be fixed in Linux or UEFI's PCI resource code (arguably if UEFI has
> already allocated from the bottom of I/O space then Linux should be
> safe to assume that there are no legacy PC I/O resources to worry
> about). The DSM is required to prevent bus numbers being reassigned,
> because if that happens then any PCI StreamIDs referenced in IORT may
> suddenly become meaningless and the association of root complex nodes
> and RMRs to physical hardware lost.

Thank you for confirming and explaining the need for DSM #5. Ard, please
could you confirm that the incompatibility with PCI devices with IO
ports is still there?

Eric

>
> Robin.
>
>> Thank you in advance
>>
>> Regards
>>
>> Eric
>>
>>
>>
>>
>>> [1]
>>> https://lore.kernel.org/linux-acpi/20210805160319.GB23085@lpieralisi/
>>>
>>>  From old:
>>> We have faced issues with 3408iMR RAID controller cards which
>>> fail to boot when SMMU is enabled. This is because these
>>> controllers make use of host memory for various caching related
>>> purposes and when SMMU is enabled the iMR firmware fails to
>>> access these memory regions as there is no mapping for them.
>>> IORT RMR provides a way for UEFI to describe and report these
>>> memory regions so that the kernel can make a unity mapping for
>>> these in SMMU.
>>>
>>> Change History:
>>>
>>> v6 --> v7
>>>   -fix pointed out by Steve to the SMMUv2 SMR bypass install in
>>> patch #8.
>>>
>>> v5 --> v6
>>> - Addressed comments from Robin & Lorenzo.
>>>    : Moved iort_parse_rmr() to acpi_iort_init() from
>>>      iort_init_platform_devices().
>>>    : Removed use of struct iort_rmr_entry during the initial
>>>      parse. Using struct iommu_resv_region instead.
>>>    : Report RMR address alignment and overlap errors, but continue.
>>>    : Reworked arm_smmu_init_bypass_stes() (patch # 6).
>>> - Updated SMMUv2 bypass SMR code. Thanks to Jon N (patch #8).
>>> - Set IOMMU protection flags(IOMMU_CACHE, IOMMU_MMIO) based
>>>    on Type of RMR region. Suggested by Jon N.
>>>
>>> v4 --> v5
>>>   -Added a fw_data union to struct iommu_resv_region and removed
>>>    struct iommu_rmr (Based on comments from Joerg/Robin).
>>>   -Added iommu_put_rmrs() to release mem.
>>>   -Thanks to Steve for verifying on SMMUv2, but not added the Tested-by
>>>    yet because of the above changes.
>>>
>>> v3 -->v4
>>> -Included the SMMUv2 SMR bypass install changes suggested by
>>>   Steve(patch #7)
>>> -As per Robin's comments, RMR reserve implementation is now
>>>   more generic  (patch #8) and dropped v3 patches 8 and 10.
>>> -Rebase to 5.13-rc1
>>>
>>> RFC v2 --> v3
>>>   -Dropped RFC tag as the ACPICA header changes are now ready to be
>>>    part of 5.13[0]. But this series still has a dependency on that
>>> patch.
>>>   -Added IORT E.b related changes(node flags, _DSM function 5 checks
>>> for
>>>    PCIe).
>>>   -Changed RMR to stream id mapping from M:N to M:1 as per the spec and
>>>    discussion here[1].
>>>   -Last two patches add support for SMMUv2(Thanks to Jon Nettleton!)
>>>
>>> Jon Nettleton (1):
>>>    iommu/arm-smmu: Get associated RMR info and install bypass SMR
>>>
>>> Shameer Kolothum (10):
>>>    ACPI/IORT: Add temporary RMR node flag definitions
>>>    iommu: Introduce a union to struct iommu_resv_region
>>>    ACPI/IORT: Add helper functions to parse RMR nodes
>>>    iommu/dma: Introduce generic helper to retrieve RMR info
>>>    ACPI/IORT: Add a helper to retrieve RMR memory regions
>>>    iommu/arm-smmu-v3: Introduce strtab init helper
>>>    iommu/arm-smmu-v3: Refactor arm_smmu_init_bypass_stes() to force
>>>      bypass
>>>    iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
>>>    iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev
>>>    iommu/arm-smmu: Reserve any RMR regions associated with a dev
>>>
>>>   drivers/acpi/arm64/iort.c                   | 305
>>> ++++++++++++++++++++
>>>   drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  91 ++++--
>>>   drivers/iommu/arm/arm-smmu/arm-smmu.c       |  65 ++++-
>>>   drivers/iommu/dma-iommu.c                   |  25 ++
>>>   include/linux/acpi_iort.h                   |  14 +
>>>   include/linux/dma-iommu.h                   |  14 +
>>>   include/linux/iommu.h                       |   9 +
>>>   7 files changed, 504 insertions(+), 19 deletions(-)
>>>
>>
>
Ard Biesheuvel March 14, 2022, 10:43 a.m. UTC | #8
On Mon, 14 Mar 2022 at 11:37, Eric Auger <eric.auger@redhat.com> wrote:
>
> Hi Robin
>
> On 3/11/22 11:34 AM, Robin Murphy wrote:
> > On 2022-03-11 08:19, Eric Auger wrote:
> >> Hi guys,
> >>
> >> On 2/21/22 4:43 PM, Shameer Kolothum wrote:
> >>> Hi,
> >>>
> >>> Since we now have an updated verion[0] of IORT spec(E.d) which
> >>> addresses the memory attributes issues discussed here [1],
> >>> this series now make use of it.
> >>>
> >>> The pull request for ACPICA E.d related changes are already
> >>> raised and can be found here,
> >>> https://github.com/acpica/acpica/pull/752
> >>>
> >>> v7 --> v8
> >>>    - Patch #1 has temp definitions for RMR related changes till
> >>>      the ACPICA header changes are part of kernel.
> >>>    - No early parsing of RMR node info and is only parsed at the
> >>>      time of use.
> >>>    - Changes to the RMR get/put API format compared to the
> >>>      previous version.
> >>>    - Support for RMR descriptor shared by multiple stream IDs.
> >>>
> >>> Please take a look and let me know your thoughts.
> >>>
> >>> Thanks,
> >>> Shameer
> >>> [0] https://developer.arm.com/documentation/den0049/ed/
> >> I still have a question on the IORT E.d spec (unrelated to this series).
> >>
> >> The spec mandates that if RMR nodes are presented in the IORT,
> >> _DSM function #5 for the PCIe host bridge ACPI device object must return
> >> 0, indicating the OS must honour the PCI config that the FW computed at
> >> boot time.
> >>
> >> However implementing this _DSM #5 as above is known to prevent PCI
> >> devices with IO ports from working, on aarch64 linux.
> >>
> >> "
> >> The reason is that EFI creates I/O port mappings below
> >>      0x1000 (in fact, at 0). However Linux, for legacy reasons, does not
> >>      support I/O ports <= 0x1000 on PCI, so the I/O assignment
> >> created by EFI
> >>      is rejected.
> >>          EFI creates the mappings primarily for itself, and up until
> >> DSM #5
> >>      started to be enforced, all PCI resource allocations that
> >> existed at
> >>      boot were ignored by Linux and recreated from scratch.
> >> "
> >>
> >> This is an excerpt of a qemu commit message that reverted the _DMS #5
> >> change (Revert "acpi/gpex: Inform os to keep firmware resource map").
> >> Has the situation changed since July 2021 (ie. has UEFI been reworked?).
> >> [+ Ard]
> >
> > FWIW I wasn't aware of that, but if it's an issue then it will need to
> > be fixed in Linux or UEFI's PCI resource code (arguably if UEFI has
> > already allocated from the bottom of I/O space then Linux should be
> > safe to assume that there are no legacy PC I/O resources to worry
> > about). The DSM is required to prevent bus numbers being reassigned,
> > because if that happens then any PCI StreamIDs referenced in IORT may
> > suddenly become meaningless and the association of root complex nodes
> > and RMRs to physical hardware lost.
>
> Thank you for confirming and explaining the need for DSM #5. Ard, please
> could you confirm that the incompatibility with PCI devices with IO
> ports is still there?
>

Yes, and this needs to be fixed in Linux. The firmware complies with
the pertinent specifications, and it is Linux that deviates from this
for legacy reasons.

IIRC, this came up on the mailing list at some point, and one of the
issues is that I/O port 0x0 is mistaken for 'no resource' or some
other exceptional case like that, so even if we fix the arbitrary
limit of 0x1000, we may still run into trouble when devices uses I/O
port 0x0.
Lorenzo Pieralisi March 14, 2022, 11:30 a.m. UTC | #9
On Mon, Mar 14, 2022 at 11:43:51AM +0100, Ard Biesheuvel wrote:
> On Mon, 14 Mar 2022 at 11:37, Eric Auger <eric.auger@redhat.com> wrote:
> >
> > Hi Robin
> >
> > On 3/11/22 11:34 AM, Robin Murphy wrote:
> > > On 2022-03-11 08:19, Eric Auger wrote:
> > >> Hi guys,
> > >>
> > >> On 2/21/22 4:43 PM, Shameer Kolothum wrote:
> > >>> Hi,
> > >>>
> > >>> Since we now have an updated verion[0] of IORT spec(E.d) which
> > >>> addresses the memory attributes issues discussed here [1],
> > >>> this series now make use of it.
> > >>>
> > >>> The pull request for ACPICA E.d related changes are already
> > >>> raised and can be found here,
> > >>> https://github.com/acpica/acpica/pull/752
> > >>>
> > >>> v7 --> v8
> > >>>    - Patch #1 has temp definitions for RMR related changes till
> > >>>      the ACPICA header changes are part of kernel.
> > >>>    - No early parsing of RMR node info and is only parsed at the
> > >>>      time of use.
> > >>>    - Changes to the RMR get/put API format compared to the
> > >>>      previous version.
> > >>>    - Support for RMR descriptor shared by multiple stream IDs.
> > >>>
> > >>> Please take a look and let me know your thoughts.
> > >>>
> > >>> Thanks,
> > >>> Shameer
> > >>> [0] https://developer.arm.com/documentation/den0049/ed/
> > >> I still have a question on the IORT E.d spec (unrelated to this series).
> > >>
> > >> The spec mandates that if RMR nodes are presented in the IORT,
> > >> _DSM function #5 for the PCIe host bridge ACPI device object must return
> > >> 0, indicating the OS must honour the PCI config that the FW computed at
> > >> boot time.
> > >>
> > >> However implementing this _DSM #5 as above is known to prevent PCI
> > >> devices with IO ports from working, on aarch64 linux.
> > >>
> > >> "
> > >> The reason is that EFI creates I/O port mappings below
> > >>      0x1000 (in fact, at 0). However Linux, for legacy reasons, does not
> > >>      support I/O ports <= 0x1000 on PCI, so the I/O assignment
> > >> created by EFI
> > >>      is rejected.
> > >>          EFI creates the mappings primarily for itself, and up until
> > >> DSM #5
> > >>      started to be enforced, all PCI resource allocations that
> > >> existed at
> > >>      boot were ignored by Linux and recreated from scratch.
> > >> "
> > >>
> > >> This is an excerpt of a qemu commit message that reverted the _DMS #5
> > >> change (Revert "acpi/gpex: Inform os to keep firmware resource map").
> > >> Has the situation changed since July 2021 (ie. has UEFI been reworked?).
> > >> [+ Ard]
> > >
> > > FWIW I wasn't aware of that, but if it's an issue then it will need to
> > > be fixed in Linux or UEFI's PCI resource code (arguably if UEFI has
> > > already allocated from the bottom of I/O space then Linux should be
> > > safe to assume that there are no legacy PC I/O resources to worry
> > > about). The DSM is required to prevent bus numbers being reassigned,
> > > because if that happens then any PCI StreamIDs referenced in IORT may
> > > suddenly become meaningless and the association of root complex nodes
> > > and RMRs to physical hardware lost.
> >
> > Thank you for confirming and explaining the need for DSM #5. Ard, please
> > could you confirm that the incompatibility with PCI devices with IO
> > ports is still there?
> >
> 
> Yes, and this needs to be fixed in Linux. The firmware complies with
> the pertinent specifications, and it is Linux that deviates from this
> for legacy reasons.
> 
> IIRC, this came up on the mailing list at some point, and one of the
> issues is that I/O port 0x0 is mistaken for 'no resource' or some
> other exceptional case like that, so even if we fix the arbitrary
> limit of 0x1000, we may still run into trouble when devices uses I/O
> port 0x0.

Yes, I need to go back to that thread to sort this out.

Thanks,
Lorenzo
Eric Auger March 15, 2022, 5:53 p.m. UTC | #10
Hi Shameer,
On 2/21/22 4:43 PM, Shameer Kolothum wrote:
> Hi,
>
> Since we now have an updated verion[0] of IORT spec(E.d) which
> addresses the memory attributes issues discussed here [1],
> this series now make use of it.
>
> The pull request for ACPICA E.d related changes are already
> raised and can be found here,
> https://github.com/acpica/acpica/pull/752
>
> v7 --> v8
>   - Patch #1 has temp definitions for RMR related changes till
>     the ACPICA header changes are part of kernel.
>   - No early parsing of RMR node info and is only parsed at the
>     time of use.
>   - Changes to the RMR get/put API format compared to the
>     previous version.
>   - Support for RMR descriptor shared by multiple stream IDs.
>
> Please take a look and let me know your thoughts.
>
> Thanks,
> Shameer
> [0] https://developer.arm.com/documentation/den0049/ed/
> [1] https://lore.kernel.org/linux-acpi/20210805160319.GB23085@lpieralisi/
>
> From old:
> We have faced issues with 3408iMR RAID controller cards which
> fail to boot when SMMU is enabled. This is because these
> controllers make use of host memory for various caching related
> purposes and when SMMU is enabled the iMR firmware fails to
> access these memory regions as there is no mapping for them.
> IORT RMR provides a way for UEFI to describe and report these
> memory regions so that the kernel can make a unity mapping for
> these in SMMU.
>
> Change History:
>
> v6 --> v7
>  -fix pointed out by Steve to the SMMUv2 SMR bypass install in patch #8.
>
> v5 --> v6
> - Addressed comments from Robin & Lorenzo.
>   : Moved iort_parse_rmr() to acpi_iort_init() from
>     iort_init_platform_devices().
>   : Removed use of struct iort_rmr_entry during the initial
>     parse. Using struct iommu_resv_region instead.
>   : Report RMR address alignment and overlap errors, but continue.
>   : Reworked arm_smmu_init_bypass_stes() (patch # 6).
> - Updated SMMUv2 bypass SMR code. Thanks to Jon N (patch #8).
> - Set IOMMU protection flags(IOMMU_CACHE, IOMMU_MMIO) based
>   on Type of RMR region. Suggested by Jon N.
>
> v4 --> v5
>  -Added a fw_data union to struct iommu_resv_region and removed
>   struct iommu_rmr (Based on comments from Joerg/Robin).
>  -Added iommu_put_rmrs() to release mem.
>  -Thanks to Steve for verifying on SMMUv2, but not added the Tested-by
>   yet because of the above changes.
>
> v3 -->v4
> -Included the SMMUv2 SMR bypass install changes suggested by
>  Steve(patch #7)
> -As per Robin's comments, RMR reserve implementation is now
>  more generic  (patch #8) and dropped v3 patches 8 and 10.
> -Rebase to 5.13-rc1
>
> RFC v2 --> v3
>  -Dropped RFC tag as the ACPICA header changes are now ready to be
>   part of 5.13[0]. But this series still has a dependency on that patch.
>  -Added IORT E.b related changes(node flags, _DSM function 5 checks for
>   PCIe).
>  -Changed RMR to stream id mapping from M:N to M:1 as per the spec and
>   discussion here[1].
>  -Last two patches add support for SMMUv2(Thanks to Jon Nettleton!)
>
> Jon Nettleton (1):
>   iommu/arm-smmu: Get associated RMR info and install bypass SMR
>
> Shameer Kolothum (10):
>   ACPI/IORT: Add temporary RMR node flag definitions
>   iommu: Introduce a union to struct iommu_resv_region
>   ACPI/IORT: Add helper functions to parse RMR nodes
>   iommu/dma: Introduce generic helper to retrieve RMR info
>   ACPI/IORT: Add a helper to retrieve RMR memory regions
>   iommu/arm-smmu-v3: Introduce strtab init helper
>   iommu/arm-smmu-v3: Refactor arm_smmu_init_bypass_stes() to force
>     bypass
>   iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
>   iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev
>   iommu/arm-smmu: Reserve any RMR regions associated with a dev
fyi, the last 2 patches have conflicts with
[PATCH v4 9/9] iommu: Split struct iommu_ops
which was applied on core branch.

Thanks

Eric
>
>  drivers/acpi/arm64/iort.c                   | 305 ++++++++++++++++++++
>  drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c |  91 ++++--
>  drivers/iommu/arm/arm-smmu/arm-smmu.c       |  65 ++++-
>  drivers/iommu/dma-iommu.c                   |  25 ++
>  include/linux/acpi_iort.h                   |  14 +
>  include/linux/dma-iommu.h                   |  14 +
>  include/linux/iommu.h                       |   9 +
>  7 files changed, 504 insertions(+), 19 deletions(-)
>
Shameerali Kolothum Thodi March 17, 2022, 3:30 p.m. UTC | #11
> -----Original Message-----
> From: Eric Auger [mailto:eric.auger@redhat.com]
> Sent: 15 March 2022 17:53
> 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>; steven.price@arm.com; Sami.Mujawar@arm.com;
> jon@solid-run.com; yangyicong <yangyicong@huawei.com>
> Subject: Re: [PATCH v8 00/11] ACPI/IORT: Support for IORT RMR node
> 
> Hi Shameer,

[...]

> >
> > Jon Nettleton (1):
> >   iommu/arm-smmu: Get associated RMR info and install bypass SMR
> >
> > Shameer Kolothum (10):
> >   ACPI/IORT: Add temporary RMR node flag definitions
> >   iommu: Introduce a union to struct iommu_resv_region
> >   ACPI/IORT: Add helper functions to parse RMR nodes
> >   iommu/dma: Introduce generic helper to retrieve RMR info
> >   ACPI/IORT: Add a helper to retrieve RMR memory regions
> >   iommu/arm-smmu-v3: Introduce strtab init helper
> >   iommu/arm-smmu-v3: Refactor arm_smmu_init_bypass_stes() to force
> >     bypass
> >   iommu/arm-smmu-v3: Get associated RMR info and install bypass STE
> >   iommu/arm-smmu-v3: Reserve any RMR regions associated with a dev
> >   iommu/arm-smmu: Reserve any RMR regions associated with a dev
> fyi, the last 2 patches have conflicts with
> [PATCH v4 9/9] iommu: Split struct iommu_ops
> which was applied on core branch.

Hi Eric,

Thanks for the heads up. I am going to respin this series soon.

All,

Please let me know if there are any further comments on this series.

Thanks,
Shameer