On 32-bit powerpc systems with more PCIe controllers and more PCI
domains, where on more PCI domains are same PCI numbers, when kernel is
compiled with CONFIG_PROC_FS=y and
CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT=y options, kernel prints
"proc_dir_entry 'pci/01' already registered" error message.
proc_dir_entry 'pci/01' already registered
WARNING: CPU: 0 PID: 1 at fs/proc/generic.c:377 proc_register+0x1a8/0x1ac
...
NIP proc_register+0x1a8/0x1ac
LR proc_register+0x1a8/0x1ac
Call Trace:
proc_register+0x1a8/0x1ac (unreliable)
_proc_mkdir+0x78/0xa4
pci_proc_attach_device+0x11c/0x168
pci_proc_init+0x80/0x98
do_one_initcall+0x80/0x284
kernel_init_freeable+0x1f4/0x2a0
kernel_init+0x24/0x150
ret_from_kernel_thread+0x5c/0x64
This regression started appearing after commit
5663568130 ("powerpc/pci: Add config option for using all 256 PCI
buses") in case in each mPCIe slot is connected PCIe card and therefore
PCI bus 1 is populated in for every PCIe controller / PCI domain.
The reason is that PCI procfs code expects that when PCI bus numbers are
not unique across all PCI domains, function pci_proc_domain() returns
true for domain dependent buses.
Fix this issue by setting PCI_ENABLE_PROC_DOMAINS and
PCI_COMPAT_DOMAIN_0 flags for 32-bit powerpc code when
CONFIG_PPC_PCI_BUS_NUM_DOMAIN_DEPENDENT is enabled. Same approach is
already implemented for 64-bit powerpc code (where PCI bus numbers are
always domain dependent).
Fixes: 5663568130 ("powerpc/pci: Add config option for using all 256 PCI buses")
Signed-off-by: Pali Rohár <pali@kernel.org>
[mpe: Trim change log oops message]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220820115113.30581-1-pali@kernel.org
0382a35bef