Re: [PATCH 00/21] SMMU enablement for NXP LS1043A and LS1046A
From: Robin Murphy
Date: Wed Sep 19 2018 - 10:37:18 EST
On 19/09/18 15:18, Laurentiu Tudor wrote:
Hi Robin,
On 19.09.2018 16:25, Robin Murphy wrote:
Hi Laurentiu,
On 19/09/18 13:35, laurentiu.tudor@xxxxxxx wrote:
From: Laurentiu Tudor <laurentiu.tudor@xxxxxxx>
This patch series adds SMMU support for NXP LS1043A and LS1046A chips
and consists mostly in important driver fixes and the required device
tree updates. It touches several subsystems and consists of three main
parts:
 - changes in soc/drivers/fsl/qbman drivers adding iommu mapping of
ÂÂÂ reserved memory areas, fixes and defered probe support
 - changes in drivers/net/ethernet/freescale/dpaa_eth drivers
ÂÂÂ consisting in misc dma mapping related fixes and probe ordering
 - addition of the actual arm smmu device tree node together with
ÂÂÂ various adjustments to the device trees
Performance impact
ÂÂÂÂ Running iperf benchmarks in a back-to-back setup (both sides
ÂÂÂÂ having smmu enabled) on a 10GBps port show an important
ÂÂÂÂ networking performance degradation of around %40 (9.48Gbps
ÂÂÂÂ linerate vs 5.45Gbps). If you need performance but without
ÂÂÂÂ SMMU support you can use "iommu.passthrough=1" to disable
ÂÂÂÂ SMMU.
USB issue and workaround
ÂÂÂÂ There's a problem with the usb controllers in these chips
ÂÂÂÂ generating smaller, 40-bit wide dma addresses instead of the 48-bit
ÂÂÂÂ supported at the smmu input. So you end up in a situation where the
ÂÂÂÂ smmu is mapped with 48-bit address translations, but the device
ÂÂÂÂ generates transactions with clipped 40-bit addresses, thus smmu
ÂÂÂÂ context faults are triggered. I encountered a similar situation for
ÂÂÂÂ mmc that IÂ managed to fix in software [1] however for USB I did not
ÂÂÂÂ find a proper place in the code to add a similar fix. The only
ÂÂÂÂ workaround I found was to add this kernel parameter which limits the
ÂÂÂÂ usb dma to 32-bit size: "xhci-hcd.quirks=0x800000".
ÂÂÂÂ This workaround if far from ideal, so any suggestions for a code
ÂÂÂÂ based workaround in this area would be greatly appreciated.
If you have a nominally-64-bit device with a
narrower-than-the-main-interconnect link in front of it, that should
already be fixed in 4.19-rc by bus_dma_mask picking up DT dma-ranges,
provided the interconnect hierarchy can be described appropriately (or
at least massaged sufficiently to satisfy the binding), e.g.:
/ {
ÂÂÂÂ...
ÂÂÂÂsoc {
ÂÂÂÂÂÂÂ ranges;
ÂÂÂÂÂÂÂ dma-ranges = <0 0 10000 0>;
ÂÂÂÂÂÂÂ dev_48bit { ... };
ÂÂÂÂÂÂÂ periph_bus {
ÂÂÂÂÂÂÂÂÂÂÂ ranges;
ÂÂÂÂÂÂÂÂÂÂÂ dma-ranges = <0 0 100 0>;
ÂÂÂÂÂÂÂÂÂÂÂ dev_40bit { ... };
ÂÂÂÂÂÂÂ };
ÂÂÂÂ};
};
and if that fails to work as expected (except for PCI hosts where
handling dma-ranges properly still needs sorting out), please do let us
know ;)
Just to confirm, Is this [1] the change I was supposed to test?
Not quite - dma-ranges is only valid for nodes representing a bus, so
putting it directly in the USB device nodes doesn't work (FWIW that's
why PCI is broken, because the parser doesn't expect the
bus-as-leaf-node case). That's teh point of that intermediate simple-bus
node represented by "periph_bus" in my example (sorry, I should have put
compatibles in to make it clearer) - often that's actually true to life
(i.e. "soc" is something like a CCI and "periph_bus" is something like
an AXI NIC gluing a bunch of lower-bandwidth DMA masters to one of the
CCI ports) but at worst it's just a necessary evil to make the binding
happy (if it literally only represents the point-to-point link between
the device master port and interconnect slave port).
Because if so, I'm still seeing context faults [2] with what looks like
clipped to 40-bits addresses. :-(
IIRC, the usb subsystem explicitly set 64-bit dma masks which in turn
will be limited to the SMMU input size of 48-bit. Won't that overwrite
the default dma mask derived from dma-ranges?
Indeed it will, but those default masks were effectively only ever a
best-effort thing anyway - it's an ease-of-implementation detail that
bus_dma_mask is not currently reflected in the device masks, although we
may eventually change that; the crucial part is that the DMA ops
implementations know about it and should now enforce it properly
regardless of whether drivers set something wider.
Robin.
---
Best Regards, Laurentiu
[1] -----------------------------------------------------------------
diff --git a/arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi
b/arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi
index 3bdea0470f69..a214c3df37fd 100644
--- a/arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi
+++ b/arch/arm64/boot/dts/freescale/fsl-ls1046a.dtsi
@@ -612,6 +612,7 @@
compatible = "snps,dwc3";
reg = <0x0 0x2f00000 0x0 0x10000>;
interrupts = <GIC_SPI 60 IRQ_TYPE_LEVEL_HIGH>;
+ dma-ranges = <0x0 0x0 0x0 0x0 0x100 0x00000000>;
dr_mode = "host";
snps,quirk-frame-length-adjustment = <0x20>;
snps,dis_rxdet_inp3_quirk;
@@ -621,6 +622,7 @@
compatible = "snps,dwc3";
reg = <0x0 0x3000000 0x0 0x10000>;
interrupts = <GIC_SPI 61 IRQ_TYPE_LEVEL_HIGH>;
+ dma-ranges = <0x0 0x0 0x0 0x0 0x100 0x00000000>;
dr_mode = "host";
snps,quirk-frame-length-adjustment = <0x20>;
snps,dis_rxdet_inp3_quirk;
@@ -630,6 +632,7 @@
compatible = "snps,dwc3";
reg = <0x0 0x3100000 0x0 0x10000>;
interrupts = <GIC_SPI 63 IRQ_TYPE_LEVEL_HIGH>;
+ dma-ranges = <0x0 0x0 0x0 0x0 0x100 0x00000000>;
dr_mode = "host";
snps,quirk-frame-length-adjustment = <0x20>;
snps,dis_rxdet_inp3_quirk;
[2] -----------------------------------------------------------------
[ 2.090577] xhci-hcd xhci-hcd.0.auto: xHCI Host Controller
[ 2.096064] xhci-hcd xhci-hcd.0.auto: new USB bus registered,
assigned bus number 2
[ 2.103720] xhci-hcd xhci-hcd.0.auto: Host supports USB 3.0 SuperSpeed
[ 2.110346] arm-smmu 9000000.iommu: Unhandled context fault:
fsr=0x402, iova=0xffffffb000, fsynr=0x1b0000, cb=3
[ 2.120449] usb usb2: We don't know the algorithms for LPM for this
host, disabling LPM.
[ 2.128717] hub 2-0:1.0: USB hub found
[ 2.132473] hub 2-0:1.0: 1 port detected
[ 2.136527] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller
[ 2.142014] xhci-hcd xhci-hcd.1.auto: new USB bus registered,
assigned bus number 3
[ 2.149747] xhci-hcd xhci-hcd.1.auto: hcc params 0x0220f66d hci
version 0x100 quirks 0x0000000002010010
[ 2.159149] xhci-hcd xhci-hcd.1.auto: irq 50, io mem 0x03000000
[ 2.165284] hub 3-0:1.0: USB hub found
[ 2.169039] hub 3-0:1.0: 1 port detected
[ 2.173051] xhci-hcd xhci-hcd.1.auto: xHCI Host Controller
[ 2.178536] xhci-hcd xhci-hcd.1.auto: new USB bus registered,
assigned bus number 4
[ 2.186193] xhci-hcd xhci-hcd.1.auto: Host supports USB 3.0 SuperSpeed
[ 2.192809] arm-smmu 9000000.iommu: Unhandled context fault:
fsr=0x402, iova=0xffffffb000, fsynr=0x1f0000, cb=4
[ 2.192822] usb usb4: We don't know the algorithms for LPM for this
host, disabling LPM.
[ 2.211141] hub 4-0:1.0: USB hub found
[ 2.214896] hub 4-0:1.0: 1 port detected
[ 2.218935] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
[ 2.224425] xhci-hcd xhci-hcd.2.auto: new USB bus registered,
assigned bus number 5
[ 2.232153] xhci-hcd xhci-hcd.2.auto: hcc params 0x0220f66d hci
version 0x100 quirks 0x0000000002010010
[ 2.241562] xhci-hcd xhci-hcd.2.auto: irq 51, io mem 0x03100000
[ 2.247694] hub 5-0:1.0: USB hub found
[ 2.251449] hub 5-0:1.0: 1 port detected
[ 2.255458] xhci-hcd xhci-hcd.2.auto: xHCI Host Controller
[ 2.260945] xhci-hcd xhci-hcd.2.auto: new USB bus registered,
assigned bus number 6
[ 2.268601] xhci-hcd xhci-hcd.2.auto: Host supports USB 3.0 SuperSpeed
[ 2.275218] arm-smmu 9000000.iommu: Unhandled context fault:
fsr=0x402, iova=0xffffffb000, fsynr=0x110000, cb=5
[ 2.275230] usb usb6: We don't know the algorithms for LPM for this
host, disabling LPM.
The patch set is based on net-next so, if generally agreed, I'd suggest
to get the patches through the netdev tree after getting all the Acks.
[1]
https://emea01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fpatchwork.kernel.org%2Fpatch%2F10506627%2F&data=02%7C01%7Claurentiu.tudor%40nxp.com%7C63c4e1dfc126488eb4ba08d61e336607%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C636729603447603039&sdata=XhjOX9aLgoe%2BSTBgZztv6zCz0vMebSXW%2Fnb2QcD5shY%3D&reserved=0
Laurentiu Tudor (21):
ÂÂ soc/fsl/qman: fixup liodns only on ppc targets
ÂÂ soc/fsl/bman: map FBPR area in the iommu
ÂÂ soc/fsl/qman: map FQD and PFDR areas in the iommu
ÂÂ soc/fsl/qman-portal: map CENA area in the iommu
ÂÂ soc/fsl/qbman: add APIs to retrieve the probing status
ÂÂ soc/fsl/qman_portals: defer probe after qman's probe
ÂÂ soc/fsl/bman_portals: defer probe after bman's probe
ÂÂ soc/fsl/qbman_portals: add APIs to retrieve the probing status
ÂÂ fsl/fman: backup and restore ICID registers
ÂÂ fsl/fman: add API to get the device behind a fman port
ÂÂ dpaa_eth: defer probing after qbman
ÂÂ dpaa_eth: base dma mappings on the fman rx port
ÂÂ dpaa_eth: fix iova handling for contiguous frames
ÂÂ dpaa_eth: fix iova handling for sg frames
ÂÂ dpaa_eth: fix SG frame cleanup
ÂÂ arm64: dts: ls1046a: add smmu node
ÂÂ arm64: dts: ls1043a: add smmu node
ÂÂ arm64: dts: ls104xa: set mask to drop TBU ID from StreamID
ÂÂ arm64: dts: ls104x: add missing dma ranges property
ÂÂ arm64: dts: ls104x: add iommu-map to pci controllers
ÂÂ arm64: dts: ls104x: make dma-coherent global to the SoC
 .../arm64/boot/dts/freescale/fsl-ls1043a.dtsi | 52 ++++++-
 .../arm64/boot/dts/freescale/fsl-ls1046a.dtsi | 48 +++++++
 .../net/ethernet/freescale/dpaa/dpaa_eth.c | 136 ++++++++++++------
 drivers/net/ethernet/freescale/fman/fman.c | 35 ++++-
 drivers/net/ethernet/freescale/fman/fman.h | 4 +
 .../net/ethernet/freescale/fman/fman_port.c | 14 ++
 .../net/ethernet/freescale/fman/fman_port.h | 2 +
 drivers/soc/fsl/qbman/bman_ccsr.c | 23 +++
 drivers/soc/fsl/qbman/bman_portal.c | 20 ++-
 drivers/soc/fsl/qbman/qman_ccsr.c | 30 ++++
 drivers/soc/fsl/qbman/qman_portal.c | 35 +++++
 include/soc/fsl/bman.h | 16 +++
 include/soc/fsl/qman.h | 17 +++
 13 files changed, 379 insertions(+), 53 deletions(-)
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