[PATCH v7 0/9] ACPI/IORT: Support for IORT RMR node

Shameer Kolothum
2021-08-05T08:08:36Z

Hi,

The series adds support to IORT RMR nodes specified in IORT
Revision E.b -ARM DEN 0049E[0]. RMR nodes are used to describe
memory ranges that are used by endpoints and require a unity
mapping in SMMU.

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

The only change from v6 is the fix pointed out by Steve to
the SMMUv2 SMR bypass install in patch #8.

Thanks to the Tested-by tags by Laurentiu with SMMUv2 and
Hanjun/Huiqiang with SMMUv3 for v6. I haven't added the tags
yet as the series still needs more review[1].

Feedback and tests on this series is very much appreciated.

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.

Thanks,
Shameer
[0] https://developer.arm.com/documentation/den0049/latest/
[1] https://lore.kernel.org/linux-acpi/20210716083442.1708-1-shameerali.kolothum.thodi@huawei.com/T/#m043c95b869973a834b2fd57f3e1ed0325c84f3b7
------
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 (8):
iommu: Introduce a union to struct iommu_resv_region
ACPI/IORT: Add support for RMR node parsing
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/dma: Reserve any RMR regions associated with a dev

drivers/acpi/arm64/iort.c | 172 +++++++++++++++++++-
drivers/iommu/arm/arm-smmu-v3/arm-smmu-v3.c | 76 +++++++--
drivers/iommu/arm/arm-smmu/arm-smmu.c | 48 ++++++
drivers/iommu/dma-iommu.c | 89 +++++++++-
include/linux/acpi_iort.h | 7 +
include/linux/dma-iommu.h | 13 ++
include/linux/iommu.h | 11 ++
7 files changed, 393 insertions(+), 23 deletions(-)

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2.17.1