6.6-stable review patch. If anyone has any objections, please let me know.
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From: Gaurav Batra gbatra@linux.ibm.com
[ Upstream commit a5c57fd2e9bd1c8ea8613a8f94fd0be5eccbf321 ]
When a PCI device is dynamically added, the kernel oopses with a NULL pointer dereference:
BUG: Kernel NULL pointer dereference on read at 0x00000030 Faulting instruction address: 0xc0000000006bbe5c Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries Modules linked in: rpadlpar_io rpaphp rpcsec_gss_krb5 auth_rpcgss nfsv4 dns_resolver nfs lockd grace fscache netfs xsk_diag bonding nft_compat nf_tables nfnetlink rfkill binfmt_misc dm_multipath rpcrdma sunrpc rdma_ucm ib_srpt ib_isert iscsi_target_mod target_core_mod ib_umad ib_iser libiscsi scsi_transport_iscsi ib_ipoib rdma_cm iw_cm ib_cm mlx5_ib ib_uverbs ib_core pseries_rng drm drm_panel_orientation_quirks xfs libcrc32c mlx5_core mlxfw sd_mod t10_pi sg tls ibmvscsi ibmveth scsi_transport_srp vmx_crypto pseries_wdt psample dm_mirror dm_region_hash dm_log dm_mod fuse CPU: 17 PID: 2685 Comm: drmgr Not tainted 6.7.0-203405+ #66 Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries NIP: c0000000006bbe5c LR: c000000000a13e68 CTR: c0000000000579f8 REGS: c00000009924f240 TRAP: 0300 Not tainted (6.7.0-203405+) MSR: 8000000000009033 <SF,EE,ME,IR,DR,RI,LE> CR: 24002220 XER: 20040006 CFAR: c000000000a13e64 DAR: 0000000000000030 DSISR: 40000000 IRQMASK: 0 ... NIP sysfs_add_link_to_group+0x34/0x94 LR iommu_device_link+0x5c/0x118 Call Trace: iommu_init_device+0x26c/0x318 (unreliable) iommu_device_link+0x5c/0x118 iommu_init_device+0xa8/0x318 iommu_probe_device+0xc0/0x134 iommu_bus_notifier+0x44/0x104 notifier_call_chain+0xb8/0x19c blocking_notifier_call_chain+0x64/0x98 bus_notify+0x50/0x7c device_add+0x640/0x918 pci_device_add+0x23c/0x298 of_create_pci_dev+0x400/0x884 of_scan_pci_dev+0x124/0x1b0 __of_scan_bus+0x78/0x18c pcibios_scan_phb+0x2a4/0x3b0 init_phb_dynamic+0xb8/0x110 dlpar_add_slot+0x170/0x3b8 [rpadlpar_io] add_slot_store.part.0+0xb4/0x130 [rpadlpar_io] kobj_attr_store+0x2c/0x48 sysfs_kf_write+0x64/0x78 kernfs_fop_write_iter+0x1b0/0x290 vfs_write+0x350/0x4a0 ksys_write+0x84/0x140 system_call_exception+0x124/0x330 system_call_vectored_common+0x15c/0x2ec
Commit a940904443e4 ("powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains") broke DLPAR add of PCI devices.
The above added iommu_device structure to pci_controller. During system boot, PCI devices are discovered and this newly added iommu_device structure is initialized by a call to iommu_device_register().
During DLPAR add of a PCI device, a new pci_controller structure is allocated but there are no calls made to iommu_device_register() interface.
Fix is to register the iommu device during DLPAR add as well.
Fixes: a940904443e4 ("powerpc/iommu: Add iommu_ops to report capabilities and allow blocking domains") Signed-off-by: Gaurav Batra gbatra@linux.ibm.com Reviewed-by: Brian King brking@linux.vnet.ibm.com Signed-off-by: Michael Ellerman mpe@ellerman.id.au Link: https://msgid.link/20240215221833.4817-1-gbatra@linux.ibm.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/powerpc/include/asm/ppc-pci.h | 10 ++++++++++ arch/powerpc/kernel/iommu.c | 23 ++++++++++++++++------ arch/powerpc/platforms/pseries/pci_dlpar.c | 4 ++++ 3 files changed, 31 insertions(+), 6 deletions(-)
diff --git a/arch/powerpc/include/asm/ppc-pci.h b/arch/powerpc/include/asm/ppc-pci.h index d9fcff5750271..2689e7139b9ea 100644 --- a/arch/powerpc/include/asm/ppc-pci.h +++ b/arch/powerpc/include/asm/ppc-pci.h @@ -30,6 +30,16 @@ void *pci_traverse_device_nodes(struct device_node *start, void *data); extern void pci_devs_phb_init_dynamic(struct pci_controller *phb);
+#if defined(CONFIG_IOMMU_API) && (defined(CONFIG_PPC_PSERIES) || \ + defined(CONFIG_PPC_POWERNV)) +extern void ppc_iommu_register_device(struct pci_controller *phb); +extern void ppc_iommu_unregister_device(struct pci_controller *phb); +#else +static inline void ppc_iommu_register_device(struct pci_controller *phb) { } +static inline void ppc_iommu_unregister_device(struct pci_controller *phb) { } +#endif + + /* From rtas_pci.h */ extern void init_pci_config_tokens (void); extern unsigned long get_phb_buid (struct device_node *); diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 14251bc5219eb..efaca0c6eff9d 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -1344,7 +1344,7 @@ static struct iommu_device *spapr_tce_iommu_probe_device(struct device *dev) struct pci_controller *hose;
if (!dev_is_pci(dev)) - return ERR_PTR(-EPERM); + return ERR_PTR(-ENODEV);
pdev = to_pci_dev(dev); hose = pdev->bus->sysdata; @@ -1393,6 +1393,21 @@ static const struct attribute_group *spapr_tce_iommu_groups[] = { NULL, };
+void ppc_iommu_register_device(struct pci_controller *phb) +{ + iommu_device_sysfs_add(&phb->iommu, phb->parent, + spapr_tce_iommu_groups, "iommu-phb%04x", + phb->global_number); + iommu_device_register(&phb->iommu, &spapr_tce_iommu_ops, + phb->parent); +} + +void ppc_iommu_unregister_device(struct pci_controller *phb) +{ + iommu_device_unregister(&phb->iommu); + iommu_device_sysfs_remove(&phb->iommu); +} + /* * This registers IOMMU devices of PHBs. This needs to happen * after core_initcall(iommu_init) + postcore_initcall(pci_driver_init) and @@ -1403,11 +1418,7 @@ static int __init spapr_tce_setup_phb_iommus_initcall(void) struct pci_controller *hose;
list_for_each_entry(hose, &hose_list, list_node) { - iommu_device_sysfs_add(&hose->iommu, hose->parent, - spapr_tce_iommu_groups, "iommu-phb%04x", - hose->global_number); - iommu_device_register(&hose->iommu, &spapr_tce_iommu_ops, - hose->parent); + ppc_iommu_register_device(hose); } return 0; } diff --git a/arch/powerpc/platforms/pseries/pci_dlpar.c b/arch/powerpc/platforms/pseries/pci_dlpar.c index 4ba8245681192..4448386268d99 100644 --- a/arch/powerpc/platforms/pseries/pci_dlpar.c +++ b/arch/powerpc/platforms/pseries/pci_dlpar.c @@ -35,6 +35,8 @@ struct pci_controller *init_phb_dynamic(struct device_node *dn)
pseries_msi_allocate_domains(phb);
+ ppc_iommu_register_device(phb); + /* Create EEH devices for the PHB */ eeh_phb_pe_create(phb);
@@ -76,6 +78,8 @@ int remove_phb_dynamic(struct pci_controller *phb) } }
+ ppc_iommu_unregister_device(phb); + pseries_msi_free_domains(phb);
/* Keep a reference so phb isn't freed yet */