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

From: Alexandre Ghiti
Date: Fri Nov 10 2023 - 13:33:49 EST


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(-)

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2.39.2