Re: [PATCH V5 1/3] riscv: mm: Prepare for reusing PTE RSW bit(9)
From: Björn Töpel
Date: Thu Jan 30 2025 - 03:42:31 EST
Chunyan Zhang <zhangchunyan@xxxxxxxxxxx> writes:
> The PTE bit(9) on RISC-V is reserved for software, it is used by devmap
> now which has to be disabled if we want to use bit(9) for other features,
> since there's no more free PTE bit on RISC-V now.
>
> So to make ARCH_HAS_PTE_DEVMAP selectable, this patch uses it as
> the build condition of devmap definitions.
Heads-up: It seems like Alistair's series [1] that removes the devmap
PTE bit will most likely land in 6.15.
Björn
[1] https://lore.kernel.org/linux-mm/cover.11189864684e31260d1408779fac9db80122047b.1736488799.git-series.apopple@xxxxxxxxxx/