Subject: Re: [PATCH v2 2/2] powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias

From: Guenter Roeck <[email-masked]>
Date: Sat, 13 Aug 2022 06:57:35 -0700

On Wed, Jul 06, 2022 at 12:21:48PM +0200, Pali Rohár wrote:
> Other Linux architectures use DT property 'linux,pci-domain' for specifying
> fixed PCI domain of PCI controller specified in Device-Tree.
> 
> And lot of Freescale powerpc boards have defined numbered pci alias in
> Device-Tree for every PCIe controller which number specify preferred PCI
> domain.
> 
> So prefer usage of DT property 'linux,pci-domain' (via function
> of_get_pci_domain_nr()) and DT pci alias (via function of_alias_get_id())
> on powerpc architecture for assigning PCI domain to PCI controller.
> 
> Fixes: 63a72284b159 ("powerpc/pci: Assign fixed PHB number based on device-tree properties")
> Signed-off-by: Pali Rohár <[email-masked]>

This patch results in a number of boot warnings with various qemu
boot tests.

Sample log and bisect results are attached.

Guenter

---
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
1 lock held by swapper/1:
 #0: c157efb0 (hose_spinlock){+.+.}-{2:2}, at: pcibios_alloc_controller+0x64/0x220
Preemption disabled at:
[<00000000>] 0x0
CPU: 0 PID: 1 Comm: swapper Not tainted 5.19.0-yocto-standard+ #1
Call Trace:
[d101dc90] [c073b264] dump_stack_lvl+0x50/0x8c (unreliable)
[d101dcb0] [c0093b70] __might_resched+0x258/0x2a8
[d101dcd0] [c0d3e634] __mutex_lock+0x6c/0x6ec
[d101dd50] [c0a84174] of_alias_get_id+0x50/0xf4
[d101dd80] [c002ec78] pcibios_alloc_controller+0x1b8/0x220
[d101ddd0] [c140c9dc] pmac_pci_init+0x198/0x784
[d101de50] [c140852c] discover_phbs+0x30/0x4c
[d101de60] [c0007fd4] do_one_initcall+0x94/0x344
[d101ded0] [c1403b40] kernel_init_freeable+0x1a8/0x22c
[d101df10] [c00086e0] kernel_init+0x34/0x160
[d101df30] [c001b334] ret_from_kernel_thread+0x5c/0x64

=============================
[ BUG: Invalid wait context ]
5.19.0-yocto-standard+ #1 Tainted: G        W
-----------------------------
swapper/1 is trying to lock:
c16a9dd8 (of_mutex){+.+.}-{3:3}, at: of_alias_get_id+0x50/0xf4
other info that might help us debug this:
context-{4:4}
1 lock held by swapper/1:
 #0: c157efb0 (hose_spinlock){+.+.}-{2:2}, at: pcibios_alloc_controller+0x64/0x220
stack backtrace:
CPU: 0 PID: 1 Comm: swapper Tainted: G        W          5.19.0-yocto-standard+ #1
Call Trace:
[d101dbc0] [c073b264] dump_stack_lvl+0x50/0x8c (unreliable)
[d101dbe0] [c00bb8e8] __lock_acquire+0x8c4/0x2278
[d101dc60] [c00ba4b8] lock_acquire+0x148/0x3b4
[d101dcd0] [c0d3e688] __mutex_lock+0xc0/0x6ec
[d101dd50] [c0a84174] of_alias_get_id+0x50/0xf4
[d101dd80] [c002ec78] pcibios_alloc_controller+0x1b8/0x220
[d101ddd0] [c140c9dc] pmac_pci_init+0x198/0x784
[d101de50] [c140852c] discover_phbs+0x30/0x4c
[d101de60] [c0007fd4] do_one_initcall+0x94/0x344
[d101ded0] [c1403b40] kernel_init_freeable+0x1a8/0x22c
[d101df10] [c00086e0] kernel_init+0x34/0x160
[d101df30] [c001b334] ret_from_kernel_thread+0x5c/0x64
Found UniNorth PCI host bridge at 0x00000000f2000000. Firmware bus number: 0->0
PCI host bridge /pci@f2000000 (primary) ranges:
  IO 0x00000000f2000000..0x00000000f27fffff -> 0x0000000000000000
 MEM 0x0000000080000000..0x000000008fffffff -> 0x0000000080000000

---
# bad: [69dac8e431af26173ca0a1ebc87054e01c585bcc] Merge tag 'riscv-for-linus-5.20-mw2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
# good: [6614a3c3164a5df2b54abb0b3559f51041cf705b] Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
git bisect start 'HEAD' '6614a3c3164a'
# bad: [24cb958695724ffb4488ef4f65892c0767bcd2f2] Merge tag 's390-5.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
git bisect bad 24cb958695724ffb4488ef4f65892c0767bcd2f2
# good: [a3b5d4715fd5a839857f8b7be78dff258a8d5a47] Merge tag 'asoc-v5.20-2' of https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus
git bisect good a3b5d4715fd5a839857f8b7be78dff258a8d5a47
# good: [1d239c1eb873c7d6c6cbc80d68330c939fd86136] Merge tag 'iommu-updates-v5.20-or-v6.0' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
git bisect good 1d239c1eb873c7d6c6cbc80d68330c939fd86136
# bad: [4cfa6ff24a9744ba484521c38bea613134fbfcb3] powerpc/64e: Fix kexec build error
git bisect bad 4cfa6ff24a9744ba484521c38bea613134fbfcb3
# good: [78988b273d592ce74c8aecdd5d748906c38a9e9d] powerpc/perf: Give generic PMU a nice name
git bisect good 78988b273d592ce74c8aecdd5d748906c38a9e9d
# good: [de40303b54bc458d7df0d4b4ee1d296df7fe98c7] powerpc/ppc-opcode: Define and use PPC_RAW_SETB()
git bisect good de40303b54bc458d7df0d4b4ee1d296df7fe98c7
# bad: [738f9dca0df3bb630e6f06a19573ab4e31bd443a] powerpc/sysdev: Fix comment typo
git bisect bad 738f9dca0df3bb630e6f06a19573ab4e31bd443a
# good: [4d5c5bad51935482437528f7fa4dffdcb3330d8b] powerpc: Remove asm/prom.h from asm/mpc52xx.h and asm/pci.h
git bisect good 4d5c5bad51935482437528f7fa4dffdcb3330d8b
# good: [d80f6de9d601c30b53c17f00cb7cfe3169f2ddad] powerpc/iommu: Fix iommu_table_in_use for a small default DMA window case
git bisect good d80f6de9d601c30b53c17f00cb7cfe3169f2ddad
# bad: [0fe1e96fef0a5c53b4c0d1500d356f3906000f81] powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias
git bisect bad 0fe1e96fef0a5c53b4c0d1500d356f3906000f81
# good: [d20c96deb3e2c1cedc47d2be9fc110ffed81b1af] powerpc/85xx: Fix description of MPC85xx and P1/P2 boards options
git bisect good d20c96deb3e2c1cedc47d2be9fc110ffed81b1af
# first bad commit: [0fe1e96fef0a5c53b4c0d1500d356f3906000f81] powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias