[PATCH v8 01/14] riscv: prevent null-pointer dereference with sbi_remote_fence_i

[Christoph Hellwig]

On Thu, Mar 31, 2022 at 02:28:06PM +0200, Heiko Stübner wrote:
> so essentially flushes the _local_ icache first and then tries to flush
> caches on other cores, either via an ipi or via sbi.
> 
> The remote-fence callback is set correctly during sbi_init().
> The other cores are only brought up after sbi-init is done.
> 
> So it's not really about error reporting but making sure that flush_icache_all()
> does something sane even when still running on the first core.
> As I assume the "all" means on all available cores (which would be the
> core the system booted on).
> 
> Does this make it clearer what this tries to solve?

A little.  Whatever code calls this early still seems broken to me
and just just do a local flush, though.