# git rev-parse -q --verify 8d48562a2729742f767b0fdd994d6b2a56a49c63^{commit} 8d48562a2729742f767b0fdd994d6b2a56a49c63 already have revision, skipping fetch # git checkout -q -f -B kisskb 8d48562a2729742f767b0fdd994d6b2a56a49c63 # git clean -qxdf # < git log -1 # commit 8d48562a2729742f767b0fdd994d6b2a56a49c63 # Author: Michael Ellerman # Date: Mon Aug 15 16:55:23 2022 +1000 # # powerpc/pci: Fix get_phb_number() locking # # The recent change to get_phb_number() causes a DEBUG_ATOMIC_SLEEP # warning on some systems: # # 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 # # This is because pcibios_alloc_controller() holds hose_spinlock but # of_alias_get_id() takes of_mutex which can sleep. # # The hose_spinlock protects the phb_bitmap, and also the hose_list, but # it doesn't need to be held while get_phb_number() calls the OF routines, # because those are only looking up information in the device tree. # # So fix it by having get_phb_number() take the hose_spinlock itself, only # where required, and then dropping the lock before returning. # pcibios_alloc_controller() then needs to take the lock again before the # list_add() but that's safe, the order of the list is not important. # # Fixes: 0fe1e96fef0a ("powerpc/pci: Prefer PCI domain assignment via DT 'linux,pci-domain' and alias") # Reported-by: Guenter Roeck # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20220815065550.1303620-1-mpe@ellerman.id.au # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 8d48562a2729742f767b0fdd994d6b2a56a49c63 # < make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mvme5100_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- mvme5100_defconfig # < make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mvme5100_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mvme5100_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_mvme5100_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- Completed OK # rm -rf /kisskb/build/powerpc-fixes_mvme5100_defconfig_powerpc-gcc5 # Build took: 0:01:11.121819