On 2021-07-30 15:34, Anders Roxell wrote:
On 2021-07-30 13:17, Robin Murphy wrote:
On 2021-07-30 12:35, Anders Roxell wrote:
From: Robin Murphy <robin.murphy@xxxxxxx>
Now that PCI inbound window restrictions are handled generically between
the of_pci resource parsing and the IOMMU layer, and described in the
Juno DT, we can finally enable the PCIe SMMU without the risk of DMA
mappings inadvertently allocating unusable addresses.
Similarly, the relevant support for IOMMU mappings for peripheral
transfers has been hooked up in the pl330 driver for ages, so we can
happily enable the DMA SMMU without that breaking anything either.
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
When we build a kernel with 64k page size and run the ltp syscalls we
sporadically see a kernel crash while doing a mkfs on a connected SATA
drive. This is happening every third test run on any juno-r2 device in
the lab with the same kernel image (stable-rc 5.13.y, mainline and next)
with gcc-11.
Hmm, I guess 64K pages might make a difference in that we'll chew through
IOVA space a lot faster with small mappings...
I'll have to try to reproduce this locally, since the interesting thing
would be knowing what DMA address it was trying to use that went wrong, but
IOMMU tracepoints and/or dma-debug are going to generate an crazy amount of
data to sift through and try to correlate - having done it before it's not
something I'd readily ask someone else to do for me :)
On a hunch, though, does it make any difference if you remove the first
entry from the PCIe "dma-ranges" (the 0x2c1c0000 one)?
I did this change, and run the job 7 times and could not reproduce the
issue.
Thanks! And hold that thought; if it works then I suspect it probably is
the best fix, but I'll double-check and write it up properly next week.
Cheers,
Robin.
diff --git a/arch/arm64/boot/dts/arm/juno-base.dtsi b/arch/arm64/boot/dts/arm/juno-base.dtsi
index 8e7a66943b01..d3148730e951 100644
--- a/arch/arm64/boot/dts/arm/juno-base.dtsi
+++ b/arch/arm64/boot/dts/arm/juno-base.dtsi
@@ -545,8 +545,7 @@ pcie_ctlr: pcie@40000000 {
<0x02000000 0x00 0x50000000 0x00 0x50000000 0x0 0x08000000>,
<0x42000000 0x40 0x00000000 0x40 0x00000000 0x1 0x00000000>;
/* Standard AXI Translation entries as programmed by EDK2 */
- dma-ranges = <0x02000000 0x0 0x2c1c0000 0x0 0x2c1c0000 0x0 0x00040000>,
- <0x02000000 0x0 0x80000000 0x0 0x80000000 0x0 0x80000000>,
+ dma-ranges = <0x02000000 0x0 0x80000000 0x0 0x80000000 0x0 0x80000000>,
<0x43000000 0x8 0x00000000 0x8 0x00000000 0x2 0x00000000>;
#interrupt-cells = <1>;
interrupt-map-mask = <0 0 0 7>;
Cheers,
Anders
