RE: [RFC PATCH 0/4] ACPI/IORT: Support for IORT RMR node

[Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>]

Hi Steve,

> -----Original Message-----
> From: Steven Price [mailto:steven.price@arm.com]
> Sent: 28 October 2020 16:44
> 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; devel@acpica.org
> Cc: lorenzo.pieralisi@arm.com; joro@8bytes.org; Jonathan Cameron
> <jonathan.cameron@huawei.com>; Linuxarm <linuxarm@huawei.com>;
> Guohanjun (Hanjun Guo) <guohanjun@huawei.com>; robin.murphy@arm.com;
> wanghuiqiang <wanghuiqiang@huawei.com>; Sami Mujawar
> <Sami.Mujawar@arm.com>
> Subject: Re: [RFC PATCH 0/4] ACPI/IORT: Support for IORT RMR node
> 
> On 27/10/2020 11:26, Shameer Kolothum wrote:
> > The series adds support to IORT RMR nodes specified in IORT
> > Revision E -ARM DEN 0049E[0]. RMR nodes are used to describe memory
> > ranges that are used by endpoints and require a unity mapping
> > in SMMU.
> 
> Hi Shameer,
> 
> I've also been taking a look at RMR, and Sami is helping me get set up
> so that I can do some testing. We're hoping to be able to test an EFI
> framebuffer or splash screen - which has the added complication of the
> unity mapping becoming redundant if a native display driver takes over
> the display controller.
> 
> I've looked through your series and the code looks correct to me.

Thanks for taking a look and the details.

> Hopefully I'll be able to give it some testing soon.

Cool. Please update once you get a chance run the tests.

Thanks,
Shameer
 
> Thanks,
> 
> Steve
> 
> > 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.
> >
> > RFC because, Patch #1 is to update the actbl2.h and should be done
> > through acpica update. I have send out a pull request[1] for that.
> >
> > Tests:
> >
> > With a UEFI, that reports the RMR for the dev,
> > ....
> > [16F0h 5872   1]                         Type : 06
> > [16F1h 5873   2]                       Length : 007C
> > [16F3h 5875   1]                     Revision : 00
> > [1038h 0056   2]                     Reserved : 00000000
> > [1038h 0056   2]                   Identifier : 00000000
> > [16F8h 5880   4]                Mapping Count : 00000001
> > [16FCh 5884   4]               Mapping Offset : 00000040
> >
> > [1700h 5888   4]    Number of RMR Descriptors : 00000002
> > [1704h 5892   4]        RMR Descriptor Offset : 00000018
> >
> > [1708h 5896   8]          Base Address of RMR : 0000E6400000
> > [1710h 5904   8]                Length of RMR : 000000100000
> > [1718h 5912   4]                     Reserved : 00000000
> >
> > [171Ch 5916   8]          Base Address of RMR : 0000000027B00000
> > [1724h 5924   8]                Length of RMR : 0000000000C00000
> > [172Ch 5932   4]                     Reserved : 00000000
> >
> > [1730h 5936   4]                   Input base : 00000000
> > [1734h 5940   4]                     ID Count : 00000001
> > [1738h 5944   4]                  Output Base : 00000003
> > [173Ch 5948   4]             Output Reference : 00000064
> > [1740h 5952   4]        Flags (decoded below) : 00000001
> >                                 Single Mapping : 1
> > ...
> >
> > Without the series the RAID controller initilization fails as
> > below,
> >
> > ...
> > [   12.631117] megaraid_sas 0000:03:00.0: FW supports sync
> cache        : Yes
> > [   12.637360] megaraid_sas 0000:03:00.0: megasas_disable_intr_fusion is
> called outbound_intr_mask:0x40000009
> > [   18.776377] megaraid_sas 0000:03:00.0: Init cmd return status FAILED
> for SCSI host 0
> > [   23.019383] megaraid_sas 0000:03:00.0: Waiting for FW to come to
> ready state
> > [  106.684281] megaraid_sas 0000:03:00.0: FW in FAULT state, Fault
> code:0x10000 subcode:0x0 func:megasas_transition_to_ready
> > [  106.695186] megaraid_sas 0000:03:00.0: System Register set:
> > [  106.889787] megaraid_sas 0000:03:00.0: Failed to transition controller to
> ready for scsi0.
> > [  106.910475] megaraid_sas 0000:03:00.0: Failed from megasas_init_fw
> 6407
> > estuary:/$
> >
> > With the series, now the kernel has direct mapping for the dev as
> > below,
> >
> > estuary:/$ cat /sys/kernel/iommu_groups/0/reserved_regions
> > 0x0000000008000000 0x00000000080fffff msi
> > 0x0000000027b00000 0x00000000286fffff direct
> > 0x00000000e6400000 0x00000000e64fffff direct
> > estuary:/$
> >
> > ....
> > [   12.254318] megaraid_sas 0000:03:00.0: megasas_disable_intr_fusion is
> called outbound_intr_mask:0x40000009
> > [   12.739089] megaraid_sas 0000:03:00.0: FW provided supportMaxExtLDs:
> 0      max_lds: 32
> > [   12.746628] megaraid_sas 0000:03:00.0: controller type       :
> iMR(0MB)
> > [   12.752694] megaraid_sas 0000:03:00.0: Online Controller Reset(OCR)  :
> Enabled
> > [   12.759798] megaraid_sas 0000:03:00.0: Secure JBOD support   : Yes
> > [   12.765778] megaraid_sas 0000:03:00.0: NVMe passthru support : Yes
> > [   12.771931] megaraid_sas 0000:03:00.0: FW provided TM
> TaskAbort/Reset timeou: 6 secs/60 secs
> > [   12.780503] megaraid_sas 0000:03:00.0: JBOD sequence map
> support     : Yes
> > [   12.787000] megaraid_sas 0000:03:00.0: PCI Lane Margining
> support    : No
> > [   12.819179] megaraid_sas 0000:03:00.0: NVME page size        :
> (4096)
> > [   12.825672] megaraid_sas 0000:03:00.0: megasas_enable_intr_fusion is
> called outbound_intr_mask:0x40000000
> > [   12.835199] megaraid_sas 0000:03:00.0: INIT adapter done
> > [   12.873932] megaraid_sas 0000:03:00.0: pci id                :
> (0x1000)/(0x0017)/(0x19e5)/(0xd213)
> > [   12.881644] megaraid_sas 0000:03:00.0: unevenspan support    : no
> > [   12.887451] megaraid_sas 0000:03:00.0: firmware crash dump   : no
> > [   12.893344] megaraid_sas 0000:03:00.0: JBOD sequence map     :
> enabled
> >
> > RAID controller init is now success and can detect the drives
> > attached as well.
> >
> > Thanks,
> > Shameer
> >
> > [0]. https://developer.arm.com/documentation/den0049/latest/
> > [1]. https://github.com/acpica/acpica/pull/638
> >
> > Shameer Kolothum (4):
> >    ACPICA: IORT: Update for revision E
> >    ACPI/IORT: Add support for RMR node parsing
> >    ACPI/IORT: Add RMR memory regions reservation helper
> >    iommu/dma: Reserve any RMR regions associated with a dev
> >
> >   drivers/acpi/arm64/iort.c | 175
> +++++++++++++++++++++++++++++++++++++-
> >   drivers/iommu/dma-iommu.c |  12 ++-
> >   include/acpi/actbl2.h     |  25 ++++--
> >   include/linux/acpi_iort.h |   4 +
> >   4 files changed, 205 insertions(+), 11 deletions(-)
> >

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