linux/arch/s390
Heiko Carstens ecb0b9f925 s390/smp: Fix fallback CPU detection
[ Upstream commit 07a75d08cf ]

In case SCLP CPU detection does not work a fallback mechanism using SIGP is
in place. Since a cleanup this does not work correctly anymore: new CPUs
are only considered if their type matches the boot CPU.

Before the cleanup the information if a CPU type should be considered was
also part of a structure generated by the fallback mechanism and indicated
that a CPU type should not be considered when adding CPUs.

Since the rework a global SCLP state is used instead. If the global SCLP
state indicates that the CPU type should be considered and the fallback
mechanism is used, there may be a mismatch with CPU types if CPUs are
added. This can lead to a system with only a single CPU even tough there
are many more CPUs.

Address this by simply copying the boot cpu type into the generated data
structure from the fallback mechanism.

Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Fixes: d08d94306e ("s390/smp: cleanup core vs. cpu in the SCLP interface")
Reviewed-by: Mete Durlu <meted@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
History 2025-12-18 13:54:47 +01:00
..
appldata sysctl: treewide: constify the ctl_table argument of proc_handlers 2024-07-24 20:59:29 +02:00
boot s390/mm: Do not map lowcore with identity mapping 2025-08-28 16:31:15 +02:00
configs s390: Update defconfigs 2024-10-16 11:32:32 +02:00
crypto crypto: s390/sha - Fix uninitialized variable in SHA-1 and SHA-2 2025-07-17 18:37:01 +02:00
hypfs s390/hypfs: Enable limited access during lockdown 2025-08-28 16:31:16 +02:00
include s390/mm: Fix __ptep_rdp() inline assembly 2025-12-01 11:43:37 +01:00
kernel s390/smp: Fix fallback CPU detection 2025-12-18 13:54:47 +01:00
kvm KVM: s390: rename PROT_NONE to PROT_TYPE_DUMMY 2025-06-27 11:11:23 +01:00
lib s390/alternatives: Rework to allow for callbacks 2024-07-23 16:02:31 +02:00
mm s390/mm: Fix __ptep_rdp() inline assembly 2025-12-01 11:43:37 +01:00
net s390/bpf: Write back tail call counter for BPF_TRAMP_F_CALL_ORIG 2025-10-19 16:34:05 +02:00
pci s390/pci: Use pci_uevent_ers() in PCI recovery 2025-11-13 15:34:12 -05:00
purgatory s390: Add '-std=gnu11' to decompressor and purgatory CFLAGS 2025-02-08 09:58:19 +01:00
tools s390 updates for 6.12 merge window 2024-09-21 09:02:54 -07:00
Kbuild - An extensive rework of kexec and crash Kconfig from Eric DeVolder 2023-08-29 14:53:51 -07:00
Kconfig s390: Disable ARCH_WANT_OPTIMIZE_HUGETLB_VMEMMAP 2025-11-13 15:34:02 -05:00
Kconfig.debug s390/Kconfig.debug: fix indentation 2022-06-01 12:03:15 +02:00
Makefile s390: Add -Wno-pointer-sign to KBUILD_CFLAGS_DECOMPRESSOR 2025-10-19 16:33:57 +02:00
Makefile.postlink s390/build: Avoid relocation information in final vmlinux 2024-08-27 20:16:48 +02:00