riscv: fix NR_CPUS range leaking 64-bit default onto 32-bit builds

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rv32_defconfig is built in two stages:

- the generic (64-bit-oriented) "defconfig" target runs first
  and resolves a concrete NR_CPUS value using the 64BIT default.
- then 32-bit.config is merged on top via merge_config.sh,
  which does not touch NR_CPUS.

The final "make olddefconfig" pass sees NR_CPUS=256 is still within
the "2 512" range therefore never recalculates it against the 32BIT
default of 32, silently keeping the leaked 64-bit-stage value.

The NR_CPUS-scaled regions (percpu areas, ...etc) of the resulting
CONFIG_NR_CPUS=256 on a 32-bit build bloats and does not fit in the
percpu/stack layout for rv32 and hangs early boot on QEMU's virt machine.

Fix this by explicitly specify the range for 32/64 and SBI_V01/!SBI_V01.

Fixes: 0fa7497719 ("riscv: Raise default NR_CPUS for 64BIT to 256")
Signed-off-by: Leo Yu-Chi Liang <leo.liang@sifive.com>
Link: https://patch.msgid.link/20261007045229.36114-1-leo.liang@sifive.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>

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This commit is contained in:

Leo Yu-Chi Liang 2026-10-06 21:52:29 -07:00 • committed by Paul Walmsley

parent 298510bbc7

commit 07e23d0b6f

1 changed files with 3 additions and 2 deletions

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