[PATCH] irqchip: riscv-imsic: Add kernel parameter to disable IPIs

[Thomas Gleixner]

On Wed, Jun 25 2025 at 21:47, Anup Patel wrote:

$Subject...

https://www.kernel.org/doc/html/latest/process/maintainer-tip.html#patch-subject

Is it that hard?

> When injecting IPIs to a set of harts, the IMSIC IPI support will
> do a separate MMIO write to SETIPNUM_LE register of each target
> hart. This means on a platform where IMSIC is trap-n-emulated,
> there will be N MMIO traps when injecting IPI to N target harts
> hence IPIs based on IMSIC software injected MSI is slow compared
> to the SBI IPI extension.
>
> Add a kernel parameter to disable IPIs in IMSIC driver for platforms
> with trap-n-emulated IMSIC.

Why do you need a kernel parameter for that. If the platform uses trap-n
emulation, then disable the IPI muck automatically, no?

Thanks,

        tglx