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

[Steven Price <steven.price@arm.com>]

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(-)
>