Hi, with your IPMMU driver enabled under 4.13 we’re seeing a crash on boot:
[ 13.785164] Unable to handle kernel NULL pointer dereference at virtual address 00000018
[ 13.793254] [0000000000000018] user address but active_mm is swapper
[ 13.799600] Internal error: Oops: 96000004 [#1] SMP
[ 13.804466] Modules linked in: aes_neon_bs aes_neon_blk crypto_simd cryptd
[ 13.811334] CPU: 152 PID: 1529 Comm: kworker/152:1 Not tainted 4.13.0-9-generic #10-Ubuntu
[ 13.819584] Hardware name: Default string Cavium ThunderX2/Default string, BIOS 5.13 07/20/2017
[ 13.828285] Workqueue: events deferred_probe_work_func
[ 13.833410] task: ffff80bee93d0000 task.stack: ffff80bee93dc000
[ 13.839330] PC is at iommu_ops_from_fwnode+0x4c/0x90
[ 13.844282] LR is at iommu_ops_from_fwnode+0x28/0x90
The ARM SMMUv3 driver (which our platform implements) seems to be losing iommu_ops to the IPMMU driver.
Note: our platform uses ACPI for device enumeration.
I have no way to test this, but is there a reason the set_iommu isn’t in _probe?
diff --git a/drivers/iommu/ipmmu-vmsa.c b/drivers/iommu/ipmmu-vmsa.c
index 2a38aa1..d4c72da 100644
--- a/drivers/iommu/ipmmu-vmsa.c
+++ b/drivers/iommu/ipmmu-vmsa.c
@@ -1066,6 +1066,9 @@ static int ipmmu_probe(struct platform_device *pdev)
platform_set_drvdata(pdev, mmu);
+ if (!iommu_present(&platform_bus_type))
+ bus_set_iommu(&platform_bus_type, &ipmmu_ops);
+
return 0;
}
@@ -1108,9 +1111,6 @@ static int __init ipmmu_init(void)
if (ret < 0)
return ret;
- if (!iommu_present(&platform_bus_type))
- bus_set_iommu(&platform_bus_type, &ipmmu_ops);
-
return 0;
}
If I’m wrong, my apologies.
Thank you,
Ananth Jasty
Lead Software Engineer
Cavium
