diff options
| author | Nilay Shroff <nilay@linux.ibm.com> | 2026-03-10 11:21:24 +0300 |
|---|---|---|
| committer | Madhavan Srinivasan <maddy@linux.ibm.com> | 2026-03-13 09:43:35 +0300 |
| commit | 82f73ef9c41e0623e0a8bdce4fa44a7237709f0c (patch) | |
| tree | 3ceb09e6b6d1e22708f2895745031147a32e095b /include/linux | |
| parent | 146c9ab38b48004b40735b6c1e1c2b5adf6436f9 (diff) | |
| download | linux-82f73ef9c41e0623e0a8bdce4fa44a7237709f0c.tar.xz | |
powerpc/iommu: fix lockdep warning during PCI enumeration
Commit a75b2be249d6 ("iommu: Add iommu_driver_get_domain_for_dev()
helper") introduced iommu_driver_get_domain_for_dev() for driver
code paths that hold iommu_group->mutex while attaching a device
to an IOMMU domain.
The same commit also added a lockdep assertion in
iommu_get_domain_for_dev() to ensure that callers do not hold
iommu_group->mutex when invoking it.
On powerpc platforms, when PCI device ownership is switched from
BLOCKED to the PLATFORM domain, the attach callback
spapr_tce_platform_iommu_attach_dev() still calls
iommu_get_domain_for_dev(). This happens while iommu_group->mutex
is held during domain switching, which triggers the lockdep warning
below during PCI enumeration:
WARNING: drivers/iommu/iommu.c:2252 at iommu_get_domain_for_dev+0x38/0x80, CPU#2: swapper/0/1
Modules linked in:
CPU: 2 UID: 0 PID: 1 Comm: swapper/0 Not tainted 7.0.0-rc2+ #35 PREEMPT
Hardware name: IBM,9105-22A Power11 (architected) 0x820200 0xf000007 of:IBM,FW1120.00 (RB1120_115) hv:phyp pSeries
NIP: c000000000c244c4 LR: c00000000005b5a4 CTR: c00000000005b578
REGS: c00000000a7bf280 TRAP: 0700 Not tainted (7.0.0-rc2+)
MSR: 8000000002029033 <SF,VEC,EE,ME,IR,DR,RI,LE> CR: 22004422 XER: 0000000a
CFAR: c000000000c24508 IRQMASK: 0
GPR00: c00000000005b5a4 c00000000a7bf520 c000000001dc8100 0000000000000001
GPR04: c00000000f972f10 0000000000000000 0000000000000000 0000000000000001
GPR08: 0000001ffbc60000 0000000000000001 0000000000000000 0000000000000000
GPR12: c00000000005b578 c000001fffffe480 c000000000011618 0000000000000000
GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
GPR20: ffffffffffffefff 0000000000000000 c000000002d30eb0 0000000000000001
GPR24: c0000000017881f8 0000000000000000 0000000000000001 c00000000f972e00
GPR28: c00000000bbba0d0 0000000000000000 c00000000bbba0d0 c00000000f972e00
NIP [c000000000c244c4] iommu_get_domain_for_dev+0x38/0x80
LR [c00000000005b5a4] spapr_tce_platform_iommu_attach_dev+0x2c/0x98
Call Trace:
iommu_get_domain_for_dev+0x68/0x80 (unreliable)
spapr_tce_platform_iommu_attach_dev+0x2c/0x98
__iommu_attach_device+0x44/0x220
__iommu_device_set_domain+0xf4/0x194
__iommu_group_set_domain_internal+0xec/0x228
iommu_setup_default_domain+0x5f4/0x6a4
__iommu_probe_device+0x674/0x724
iommu_probe_device+0x50/0xb4
iommu_add_device+0x48/0x198
pci_dma_dev_setup_pSeriesLP+0x198/0x4f0
pcibios_bus_add_device+0x80/0x464
pci_bus_add_device+0x40/0x100
pci_bus_add_devices+0x54/0xb0
pcibios_init+0xd8/0x140
do_one_initcall+0x8c/0x598
kernel_init_freeable+0x3ec/0x850
kernel_init+0x34/0x270
ret_from_kernel_user_thread+0x14/0x1c
Fix this by using iommu_driver_get_domain_for_dev() instead of
iommu_get_domain_for_dev() in spapr_tce_platform_iommu_attach_dev(),
which is the appropriate helper for callers holding the group mutex.
Cc: stable@vger.kernel.org
Fixes: a75b2be249d6 ("iommu: Add iommu_driver_get_domain_for_dev() helper")
Closes: https://patchwork.ozlabs.org/project/linuxppc-dev/patch/d5c834ff-4c95-44dd-8bef-57242d63aeee@linux.ibm.com/
Signed-off-by: Nilay Shroff <nilay@linux.ibm.com>
Reviewed-by: Nicolin Chen <nicolinc@nvidia.com>
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
[Maddy: Added Closes, tested and reviewed by tags]
Signed-off-by: Madhavan Srinivasan <maddy@linux.ibm.com>
Link: https://patch.msgid.link/20260310082129.3630996-1-nilay@linux.ibm.com
Diffstat (limited to 'include/linux')
0 files changed, 0 insertions, 0 deletions