kernel.git/arch/powerpc/kexec, branch linux-6.1.y

powerpc/kexec: Enable SMT before waking offline CPUs

2026-01-11T14:18:56Z

commit c2296a1e42418556efbeb5636c4fa6aa6106713a upstream. If SMT is disabled or a partial SMT state is enabled, when a new kernel image is loaded for kexec, on reboot the following warning is observed: kexec: Waking offline cpu 228. WARNING: CPU: 0 PID: 9062 at arch/powerpc/kexec/core_64.c:223 kexec_prepare_cpus+0x1b0/0x1bc [snip] NIP kexec_prepare_cpus+0x1b0/0x1bc LR kexec_prepare_cpus+0x1a0/0x1bc Call Trace: kexec_prepare_cpus+0x1a0/0x1bc (unreliable) default_machine_kexec+0x160/0x19c machine_kexec+0x80/0x88 kernel_kexec+0xd0/0x118 __do_sys_reboot+0x210/0x2c4 system_call_exception+0x124/0x320 system_call_vectored_common+0x15c/0x2ec This occurs as add_cpu() fails due to cpu_bootable() returning false for CPUs that fail the cpu_smt_thread_allowed() check or non primary threads if SMT is disabled. Fix the issue by enabling SMT and resetting the number of SMT threads to the number of threads per core, before attempting to wake up all present CPUs. Fixes: 38253464bc82 ("cpu/SMT: Create topology_smt_thread_allowed()") Reported-by: Sachin P Bappalige Cc: stable@vger.kernel.org # v6.6+ Reviewed-by: Srikar Dronamraju Signed-off-by: Nysal Jan K.A. Tested-by: Samir M Reviewed-by: Sourabh Jain Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20251028105516.26258-1-nysal@linux.ibm.com Signed-off-by: Greg Kroah-Hartman

powerpc/crash: Fix non-smp kexec preparation

2025-06-27T10:07:06Z

[ Upstream commit 882b25af265de8e05c66f72b9a29f6047102958f ] In non-smp configurations, crash_kexec_prepare is never called in the crash shutdown path. One result of this is that the crashing_cpu variable is never set, preventing crash_save_cpu from storing the NT_PRSTATUS elf note in the core dump. Fixes: c7255058b543 ("powerpc/crash: save cpu register data in crash_smp_send_stop()") Signed-off-by: Eddie James Reviewed-by: Hari Bathini Signed-off-by: Madhavan Srinivasan Link: https://patch.msgid.link/20250211162054.857762-1-eajames@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/kexec: Fix return of uninitialized variable

2024-12-14T18:53:42Z

[ Upstream commit 83b5a407fbb73e6965adfb4bd0a803724bf87f96 ] of_property_read_u64() can fail and leave the variable uninitialized, which will then be used. Return error if reading the property failed. Fixes: 2e6bd221d96f ("powerpc/kexec_file: Enable early kernel OPAL calls") Signed-off-by: Zhang Zekun Signed-off-by: Michael Ellerman Link: https://patch.msgid.link/20240930075628.125138-1-zhangzekun11@huawei.com Signed-off-by: Sasha Levin

powerpc/kexec_file: fix cpus node update to FDT

2024-08-03T06:49:19Z

[ Upstream commit 932bed41217059638c78a75411b7893b121d2162 ] While updating the cpus node, commit 40c753993e3a ("powerpc/kexec_file: Use current CPU info while setting up FDT") first deletes all subnodes under the /cpus node. However, while adding sub-nodes back, it missed adding cpus subnodes whose device_type != "cpu", such as l2-cache*, l3-cache*, ibm,powerpc-cpu-features. Fix this by only deleting cpus sub-nodes of device_type == "cpus" and then adding all available nodes with device_type == "cpu". Fixes: 40c753993e3a ("powerpc/kexec_file: Use current CPU info while setting up FDT") Signed-off-by: Sourabh Jain Signed-off-by: Michael Ellerman Link: https://msgid.link/20240510102235.2269496-3-sourabhjain@linux.ibm.com Signed-off-by: Sasha Levin

powerpc/kexec: make the update_cpus_node() function public

2024-08-03T06:49:18Z

[ Upstream commit 0857beff9c1ec8bb421a8b7a721da0f34cc886c0 ] Move the update_cpus_node() from kexec/{file_load_64.c => core_64.c} to allow other kexec components to use it. Later in the series, this function is used for in-kernel updates to the kdump image during CPU/memory hotplug or online/offline events for both kexec_load and kexec_file_load syscalls. No functional changes are intended. Signed-off-by: Sourabh Jain Acked-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://msgid.link/20240326055413.186534-5-sourabhjain@linux.ibm.com Stable-dep-of: 932bed412170 ("powerpc/kexec_file: fix cpus node update to FDT") Signed-off-by: Sasha Levin

powerpc/pseries: Fix scv instruction crash with kexec

2024-07-11T10:47:15Z

commit 21a741eb75f80397e5f7d3739e24d7d75e619011 upstream. kexec on pseries disables AIL (reloc_on_exc), required for scv instruction support, before other CPUs have been shut down. This means they can execute scv instructions after AIL is disabled, which causes an interrupt at an unexpected entry location that crashes the kernel. Change the kexec sequence to disable AIL after other CPUs have been brought down. As a refresher, the real-mode scv interrupt vector is 0x17000, and the fixed-location head code probably couldn't easily deal with implementing such high addresses so it was just decided not to support that interrupt at all. Fixes: 7fa95f9adaee ("powerpc/64s: system call support for scv/rfscv instructions") Cc: stable@vger.kernel.org # v5.9+ Reported-by: Sourabh Jain Closes: https://lore.kernel.org/3b4b2943-49ad-4619-b195-bc416f1d1409@linux.ibm.com Signed-off-by: Nicholas Piggin Tested-by: Gautam Menghani Tested-by: Sourabh Jain Link: https://msgid.link/20240625134047.298759-1-npiggin@gmail.com Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman

powerpc/64/kdump: Limit kdump base to 512MB

2022-09-28T09:22:09Z

Since commit e641eb03ab2b0 ("powerpc: Fix up the kdump base cap to 128M") memory for kdump kernel has been reserved at an offset of 128MB. This held up well for a long time before running into boot failure on LPARs having a lot of cores. Commit 7c5ed82b800d8 ("powerpc: Set crashkernel offset to mid of RMA region") fixed this boot failure by moving the offset to mid of RMA region. This change meant the offset is either 256MB or 512MB on LPARs as ppc64_rma_size was 512MB or 1024MB owing to commit 103a8542cb35b ("powerpc/book3s64/ radix: Fix boot failure with large amount of guest memory"). But ppc64_rma_size can be larger as well with newer f/w. So, limit crashkernel reservation offset to 512MB to avoid running into boot failures during kdump kernel boot, due to RTAS or other allocation restrictions. Also, while here, use SZ_128M instead of opening coding it. Signed-off-by: Hari Bathini Tested-by: Sachin Sant Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220912065031.57416-1-hbathini@linux.ibm.com

powerpc: Remove CONFIG_PPC_BOOK3E

2022-09-26T13:00:13Z

CONFIG_PPC_BOOK3E is redundant with CONFIG_PPC_BOOK3E_64. The later is more explicit about the fact that it's a 64 bits target. Remove CONFIG_PPC_BOOK3E. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/5d0891490813c19cdcfc04678f512ea68cba3e64.1663606876.git.christophe.leroy@csgroup.eu

powerpc: Remove CONFIG_FSL_BOOKE

2022-09-26T12:47:37Z

PPC_85xx is PPC32 only. PPC_85xx always selects E500 and is the only PPC32 that selects E500. FSL_BOOKE is selected when E500 and PPC32 are selected. So FSL_BOOKE is redundant with PPC_85xx. Remove FSL_BOOKE. And rename four files accordingly. cpu_setup_fsl_booke.S is not renamed because it is linked to PPC_FSL_BOOK3E and not to FSL_BOOKE as suggested by its name. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/08e3e15594e66d63b9e89c5b4f9c35153913c28f.1663606875.git.christophe.leroy@csgroup.eu

powerpc/kexec: Fix build failure from uninitialised variable

2022-08-10T05:55:20Z

clang 14 won't build because ret is uninitialised and can be returned if both prop and fdtprop are NULL. Drop the ret variable and return an error in that failure case. Fixes: b1fc44eaa9ba ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window") Suggested-by: Christophe Leroy Signed-off-by: Russell Currey Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220810054331.373761-1-ruscur@russell.cc