Re: [PATCH v4 0/4] Add system mmu support for Armada-806

From: Robin Murphy
Date: Tue Oct 13 2020 - 09:08:46 EST


On 2020-10-06 16:16, Denis Odintsov wrote:
Hi,

Am 15.07.2020 um 09:06 schrieb Tomasz Nowicki <tn@xxxxxxxxxxxx>:

The series is meant to support SMMU for AP806 and a workaround
for accessing ARM SMMU 64bit registers is the gist of it.

For the record, AP-806 can't access SMMU registers with 64bit width.
This patches split the readq/writeq into two 32bit accesses instead
and update DT bindings.

The series was successfully tested on a vanilla v5.8-rc3 kernel and
Intel e1000e PCIe NIC. The same for platform devices like SATA and USB.

For reference, previous versions are listed below:
V1: https://lkml.org/lkml/2018/10/15/373
V2: https://lkml.org/lkml/2019/7/11/426
V3: https://lkml.org/lkml/2020/7/2/1114


1) After enabling SMMU on Armada 8040, and ARM_SMMU_DISABLE_BYPASS_BY_DEFAUL=y by default in kernel since 954a03be033c7cef80ddc232e7cbdb17df735663,
internal eMMC is prevented from being initialised (as there is no iommus property for ap_sdhci0)
Disabling "Disable bypass by default" make it work, but the patch highly suggest doing it properly.
I wasn't able to find correct path for ap_sdhci for iommus in any publicly available documentation,
would be highly appreciated addressed properly, thank you!

FWIW the SMMU tells you the offending unmatched Stream ID, so if faults can reasonably be correlated with a particular device making accesses, you can effectively discover the Stream ID assignment by trial and error. Often that can be easier than trying to find formal documentation anyway ;)

2) Second issue I got (btw I have ClearFog GT 8k armada-8040 based board) is mpci ath10k card.
It is found, it is enumerated, it is visible in lspci, but it fails to be initialised. Here is the log:

[ 1.743754] armada8k-pcie f2600000.pcie: host bridge /cp0/pcie@f2600000 ranges:
[ 1.751116] armada8k-pcie f2600000.pcie: MEM 0x00f6000000..0x00f6efffff -> 0x00f6000000
[ 1.964690] armada8k-pcie f2600000.pcie: Link up
[ 1.969379] armada8k-pcie f2600000.pcie: PCI host bridge to bus 0000:00
[ 1.976026] pci_bus 0000:00: root bus resource [bus 00-ff]
[ 1.981537] pci_bus 0000:00: root bus resource [mem 0xf6000000-0xf6efffff]
[ 1.988462] pci 0000:00:00.0: [11ab:0110] type 01 class 0x060400
[ 1.994504] pci 0000:00:00.0: reg 0x10: [mem 0x00000000-0x000fffff]
[ 2.000843] pci 0000:00:00.0: supports D1 D2
[ 2.005132] pci 0000:00:00.0: PME# supported from D0 D1 D3hot
[ 2.011853] pci 0000:01:00.0: [168c:003c] type 00 class 0x028000
[ 2.018001] pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x001fffff 64bit]
[ 2.025002] pci 0000:01:00.0: reg 0x30: [mem 0x00000000-0x0000ffff pref]
[ 2.032111] pci 0000:01:00.0: supports D1 D2
[ 2.049409] pci 0000:00:00.0: BAR 14: assigned [mem 0xf6000000-0xf61fffff]
[ 2.056322] pci 0000:00:00.0: BAR 0: assigned [mem 0xf6200000-0xf62fffff]
[ 2.063142] pci 0000:00:00.0: BAR 15: assigned [mem 0xf6300000-0xf63fffff pref]
[ 2.070484] pci 0000:01:00.0: BAR 0: assigned [mem 0xf6000000-0xf61fffff 64bit]
[ 2.077880] pci 0000:01:00.0: BAR 6: assigned [mem 0xf6300000-0xf630ffff pref]
[ 2.085135] pci 0000:00:00.0: PCI bridge to [bus 01-ff]
[ 2.090384] pci 0000:00:00.0: bridge window [mem 0xf6000000-0xf61fffff]
[ 2.097202] pci 0000:00:00.0: bridge window [mem 0xf6300000-0xf63fffff pref]
[ 2.104539] pcieport 0000:00:00.0: Adding to iommu group 4
[ 2.110232] pcieport 0000:00:00.0: PME: Signaling with IRQ 38
[ 2.116141] pcieport 0000:00:00.0: AER: enabled with IRQ 38
[ 8.131135] ath10k_pci 0000:01:00.0: Adding to iommu group 4
[ 8.131874] ath10k_pci 0000:01:00.0: enabling device (0000 -> 0002)
[ 8.132203] ath10k_pci 0000:01:00.0: pci irq msi oper_irq_mode 2 irq_mode 0 reset_mode 0

up to that point the log is the same as without SMMU enabled, except "Adding to iommu group N" lines, and IRQ being 37

Does forcing ath10k to use legacy interrupts rather than MSIs make a difference?

Judging by the DT it looks like MSIs ought to be targeting the GICv2M widget, but if things somehow end up trying to use the PCIe controller's internal MSI doorbell (upstream of SMMU translation) instead, then that might account for general interrupt-related weirdness.

Robin.

[ 8.221328] ath10k_pci 0000:01:00.0: failed to poke copy engine: -16
[ 8.313362] ath10k_pci 0000:01:00.0: failed to poke copy engine: -16
[ 8.409373] ath10k_pci 0000:01:00.0: failed to poke copy engine: -16
[ 8.553433] ath10k_pci 0000:01:00.0: failed to poke copy engine: -16
[ 8.641370] ath10k_pci 0000:01:00.0: failed to poke copy engine: -16
[ 8.737979] ath10k_pci 0000:01:00.0: failed to poke copy engine: -16
[ 8.807356] ath10k_pci 0000:01:00.0: Failed to get pcie state addr: -16
[ 8.814032] ath10k_pci 0000:01:00.0: failed to setup init config: -16
[ 8.820605] ath10k_pci 0000:01:00.0: could not power on hif bus (-16)
[ 8.827111] ath10k_pci 0000:01:00.0: could not probe fw (-16)

Thank you!

v3 -> v4
- call cfg_probe() impl hook a bit earlier which simplifies errata handling
- use hi_lo_readq_relaxed() and hi_lo_writeq_relaxed() for register accessors
- keep SMMU status disabled by default and enable where possible (DTS changes)
- commit logs improvements and other minor fixes

Hanna Hawa (1):
iommu/arm-smmu: Workaround for Marvell Armada-AP806 SoC erratum
#582743

Marcin Wojtas (1):
arm64: dts: marvell: add SMMU support

Tomasz Nowicki (2):
iommu/arm-smmu: Call configuration impl hook before consuming features
dt-bindings: arm-smmu: add compatible string for Marvell Armada-AP806
SMMU-500

Documentation/arm64/silicon-errata.rst | 3 ++
.../devicetree/bindings/iommu/arm,smmu.yaml | 4 ++
arch/arm64/boot/dts/marvell/armada-7040.dtsi | 28 ++++++++++++
arch/arm64/boot/dts/marvell/armada-8040.dtsi | 40 +++++++++++++++++
arch/arm64/boot/dts/marvell/armada-ap80x.dtsi | 18 ++++++++
drivers/iommu/arm-smmu-impl.c | 45 +++++++++++++++++++
drivers/iommu/arm-smmu.c | 11 +++--
7 files changed, 145 insertions(+), 4 deletions(-)

--
2.17.1

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