[PATCH 0/2] riscv: Enable percpu page first chunk allocator

Alexandre Ghiti alexghiti at rivosinc.com
Fri Nov 10 06:07:19 PST 2023


While working with pcpu variables, I noticed that riscv did not support
first chunk allocation in the vmalloc area which may be needed as a fallback
in case of a sparse NUMA configuration.

patch 1 starts by introducing a new function flush_cache_vmap_early() which
is needed since a new vmalloc mapping is established and directly accessed:
on riscv, this would likely fail in case of a reordered access or if the
uarch caches invalid entries in TLB.

patch 2 simply enables the page percpu first chunk allocator in riscv.

Alexandre Ghiti (2):
  mm: Introduce flush_cache_vmap_early() and its riscv implementation
  riscv: Enable pcpu page first chunk allocator

 arch/riscv/Kconfig                  | 2 ++
 arch/riscv/include/asm/cacheflush.h | 3 ++-
 arch/riscv/include/asm/tlbflush.h   | 2 ++
 arch/riscv/mm/kasan_init.c          | 8 ++++++++
 arch/riscv/mm/tlbflush.c            | 5 +++++
 include/asm-generic/cacheflush.h    | 6 ++++++
 mm/percpu.c                         | 8 +-------
 7 files changed, 26 insertions(+), 8 deletions(-)

-- 
2.39.2




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