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author | Vasant Hegde <vasant.hegde@amd.com> | 2024-04-04 12:27:17 +0200 |
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committer | Joerg Roedel <jroedel@suse.de> | 2024-04-12 12:02:16 +0200 |
commit | 84b1cec4fac5889b6d138d4b5ff6f2d5ef126c5e (patch) | |
tree | 572a44e15f5c8952040017ace3befd6be8190b92 /drivers/iommu/amd/init.c | |
parent | Linux 6.9-rc3 (diff) | |
download | linux-84b1cec4fac5889b6d138d4b5ff6f2d5ef126c5e.tar.xz linux-84b1cec4fac5889b6d138d4b5ff6f2d5ef126c5e.zip |
iommu/amd: Fix possible irq lock inversion dependency issue
LOCKDEP detector reported below warning:
----------------------------------------
[ 23.796949] ========================================================
[ 23.796950] WARNING: possible irq lock inversion dependency detected
[ 23.796952] 6.8.0fix+ #811 Not tainted
[ 23.796954] --------------------------------------------------------
[ 23.796954] kworker/0:1/8 just changed the state of lock:
[ 23.796956] ff365325e084a9b8 (&domain->lock){..-.}-{3:3}, at: amd_iommu_flush_iotlb_all+0x1f/0x50
[ 23.796969] but this lock took another, SOFTIRQ-unsafe lock in the past:
[ 23.796970] (pd_bitmap_lock){+.+.}-{3:3}
[ 23.796972]
and interrupts could create inverse lock ordering between them.
[ 23.796973]
other info that might help us debug this:
[ 23.796974] Chain exists of:
&domain->lock --> &dev_data->lock --> pd_bitmap_lock
[ 23.796980] Possible interrupt unsafe locking scenario:
[ 23.796981] CPU0 CPU1
[ 23.796982] ---- ----
[ 23.796983] lock(pd_bitmap_lock);
[ 23.796985] local_irq_disable();
[ 23.796985] lock(&domain->lock);
[ 23.796988] lock(&dev_data->lock);
[ 23.796990] <Interrupt>
[ 23.796991] lock(&domain->lock);
Fix this issue by disabling interrupt when acquiring pd_bitmap_lock.
Note that this is temporary fix. We have a plan to replace custom bitmap
allocator with IDA allocator.
Fixes: 87a6f1f22c97 ("iommu/amd: Introduce per-device domain ID to fix potential TLB aliasing issue")
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Vasant Hegde <vasant.hegde@amd.com>
Link: https://lore.kernel.org/r/20240404102717.6705-1-vasant.hegde@amd.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/amd/init.c')
0 files changed, 0 insertions, 0 deletions