[PATCH 0/2] bpf/s390: Implement get_preempt_count()

[Ilya Leoshkevich <iii@linux.ibm.com>]

Hi,

This series adds get_preempt_count() BPF implementation for s390.
On s390 preempt_count lives in lowcore: a per-cpu data structure
mapped at virtual address 0 or 0x70000 depending on the kernel
command line.

Patch 1 adds a kfunc to obtain lowcore address.
Patch 2 is the implementation that delegates to it.

Best regards,
Ilya

Ilya Leoshkevich (2):
  s390: Introduce bpf_get_lowcore() kfunc
  bpf/s390: Implement get_preempt_count()

 arch/s390/kernel/Makefile                      |  2 ++
 arch/s390/kernel/bpf.c                         | 12 ++++++++++++
 kernel/bpf/helpers.c                           |  3 +++
 tools/testing/selftests/bpf/bpf_experimental.h | 11 +++++++++++
 4 files changed, 28 insertions(+)
 create mode 100644 arch/s390/kernel/bpf.c

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2.53.0