diff mbox series

[v2] powerpc/pseries/iommu: DLPAR ADD of pci device doesn't completely initialize pci_controller structure

Message ID 20240122222407.39603-1-gbatra@linux.ibm.com (mailing list archive)
State Accepted
Commit ed8b94f6e0acd652ce69bd69d678a0c769172df8
Headers show
Series [v2] powerpc/pseries/iommu: DLPAR ADD of pci device doesn't completely initialize pci_controller structure | expand

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Commit Message

Gaurav Batra Jan. 22, 2024, 10:24 p.m. UTC 
When a PCI device is Dynamically added, LPAR OOPS with NULL pointer
exception.

Complete stack is as below

[  211.239206] BUG: Kernel NULL pointer dereference on read at 0x00000030
[  211.239210] Faulting instruction address: 0xc0000000006bbe5c
[  211.239214] Oops: Kernel access of bad area, sig: 11 [#1]
[  211.239218] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
[  211.239223] 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
[  211.239280] CPU: 17 PID: 2685 Comm: drmgr Not tainted 6.7.0-203405+ #66
[  211.239284] Hardware name: IBM,9080-HEX POWER10 (raw) 0x800200 0xf000006 of:IBM,FW1060.00 (NH1060_008) hv:phyp pSeries
[  211.239289] NIP:  c0000000006bbe5c LR: c000000000a13e68 CTR: c0000000000579f8
[  211.239293] REGS: c00000009924f240 TRAP: 0300   Not tainted  (6.7.0-203405+)
[  211.239298] MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 24002220  XER: 20040006
[  211.239306] CFAR: c000000000a13e64 DAR: 0000000000000030 DSISR: 40000000 IRQMASK: 0
[  211.239306] GPR00: c000000000a13e68 c00000009924f4e0 c0000000015a2b00 0000000000000000
[  211.239306] GPR04: c0000000013c5590 0000000000000000 c000000006d07970 c0000000d8f8f180
[  211.239306] GPR08: 00000000000006ec c0000000d8f8f180 c000000002c35d58 0000000024002228
[  211.239306] GPR12: c0000000000579f8 c0000003ffeb3880 0000000000000000 0000000000000000
[  211.239306] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[  211.239306] GPR20: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[  211.239306] GPR24: c0000000919460c0 0000000000000000 fffffffffffff000 c0000000010088e8
[  211.239306] GPR28: c0000000013c5590 c000000006d07970 c0000000919460c0 c0000000919460c0
[  211.239354] NIP [c0000000006bbe5c] sysfs_add_link_to_group+0x34/0x94
[  211.239361] LR [c000000000a13e68] iommu_device_link+0x5c/0x118
[  211.239367] Call Trace:
[  211.239369] [c00000009924f4e0] [c000000000a109b8] iommu_init_device+0x26c/0x318 (unreliable)
[  211.239376] [c00000009924f520] [c000000000a13e68] iommu_device_link+0x5c/0x118
[  211.239382] [c00000009924f560] [c000000000a107f4] iommu_init_device+0xa8/0x318
[  211.239387] [c00000009924f5c0] [c000000000a11a08] iommu_probe_device+0xc0/0x134
[  211.239393] [c00000009924f600] [c000000000a11ac0] iommu_bus_notifier+0x44/0x104
[  211.239398] [c00000009924f640] [c00000000018dcc0] notifier_call_chain+0xb8/0x19c
[  211.239405] [c00000009924f6a0] [c00000000018df88] blocking_notifier_call_chain+0x64/0x98
[  211.239411] [c00000009924f6e0] [c000000000a250fc] bus_notify+0x50/0x7c
[  211.239416] [c00000009924f720] [c000000000a20838] device_add+0x640/0x918
[  211.239421] [c00000009924f7f0] [c0000000008f1a34] pci_device_add+0x23c/0x298
[  211.239427] [c00000009924f840] [c000000000077460] of_create_pci_dev+0x400/0x884
[  211.239432] [c00000009924f8e0] [c000000000077a08] of_scan_pci_dev+0x124/0x1b0
[  211.239437] [c00000009924f980] [c000000000077b0c] __of_scan_bus+0x78/0x18c
[  211.239442] [c00000009924fa10] [c000000000073f90] pcibios_scan_phb+0x2a4/0x3b0
[  211.239447] [c00000009924fad0] [c0000000001007a8] init_phb_dynamic+0xb8/0x110
[  211.239453] [c00000009924fb40] [c008000006920620] dlpar_add_slot+0x170/0x3b8 [rpadlpar_io]
[  211.239461] [c00000009924fbe0] [c008000006920d64] add_slot_store.part.0+0xb4/0x130 [rpadlpar_io]
[  211.239468] [c00000009924fc70] [c000000000fb4144] kobj_attr_store+0x2c/0x48
[  211.239473] [c00000009924fc90] [c0000000006b90e4] sysfs_kf_write+0x64/0x78
[  211.239479] [c00000009924fcb0] [c0000000006b7b78] kernfs_fop_write_iter+0x1b0/0x290
[  211.239485] [c00000009924fd00] [c0000000005b6fdc] vfs_write+0x350/0x4a0
[  211.239491] [c00000009924fdc0] [c0000000005b7450] ksys_write+0x84/0x140
[  211.239496] [c00000009924fe10] [c000000000030a04] system_call_exception+0x124/0x330
[  211.239502] [c00000009924fe50] [c00000000000cedc] 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 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 would be to register 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>
---
 arch/powerpc/include/asm/ppc-pci.h         |  3 +++
 arch/powerpc/kernel/iommu.c                | 21 ++++++++++++++++-----
 arch/powerpc/platforms/pseries/pci_dlpar.c |  4 ++++
 3 files changed, 23 insertions(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/arch/powerpc/include/asm/ppc-pci.h b/arch/powerpc/include/asm/ppc-pci.h
index ce2b1b5eebdd..c3a3f3df36d1 100644
--- a/arch/powerpc/include/asm/ppc-pci.h
+++ b/arch/powerpc/include/asm/ppc-pci.h
@@ -29,6 +29,9 @@  void *pci_traverse_device_nodes(struct device_node *start,
 				void *(*fn)(struct device_node *, void *),
 				void *data);
 extern void pci_devs_phb_init_dynamic(struct pci_controller *phb);
+extern void ppc_iommu_register_device(struct pci_controller *phb);
+extern void ppc_iommu_unregister_device(struct pci_controller *phb);
+
 
 /* From rtas_pci.h */
 extern void init_pci_config_tokens (void);
diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c
index ebe259bdd462..c6f62e130d55 100644
--- a/arch/powerpc/kernel/iommu.c
+++ b/arch/powerpc/kernel/iommu.c
@@ -1388,6 +1388,21 @@  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
@@ -1398,11 +1413,7 @@  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 4ba824568119..4448386268d9 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 */