Flush cpu caches

[Ian Lepore]

On Tue, 2019-07-09 at 17:30 +0000, adr wrote:
> On Tue, 9 Jul 2019, Ian Lepore wrote:
> 
> > Date: Tue, 09 Jul 2019 11:20:23 -0600
> > From: Ian Lepore <ian at freebsd.org>
> > To: adr <adr at SDF.ORG>, freebsd-arm at freebsd.org
> > Subject: Re: Flush cpu caches
> > 
> > On Tue, 2019-07-09 at 16:54 +0000, adr wrote:
> > > First of all, hello everyone.
> > > 
> > > I'm completely new to FreeBSD (not to BSD). I need to use
> > > something like arm_sync_icache(2) on OpenBSD and NetBSD.
> > > 
> > > I'd find what I think I need in machine/cpufunc.h, but the linker
> > > can't find any function symbol. I suppose I have to pass a lib to
> > > the linker, but no idea which one.
> > > 
> > > Some help?
> > > 
> > > Thanks in advance,
> > > adr.
> > > 
> > 
> > Hmmm, we have a prototype for arm_sync_icache() but no library
> > function
> > for it.  I'll make a note to look into that asap.
> > 
> > Until I figure out how to add it properly, you could implement it
> > locally like this:
> > 
> >    #include <machine/sysarch.h>
> > 
> >    void arm_sync_icache(u_int addr, int len)
> >    {
> >        struct arm_sync_icache_args arg;
> > 
> >        arg.addr = (uintptr_t)addr;
> >        arg.len = (uintptr_t)len;
> > 
> >        sysarch(ARM_SYNC_ICACHE, &arg);
> >    }
> > 
> > -- Ian
> > 
> > 
> 
> ARM_SYNC_ICACHE
> 
> Thanks a lot, that is all I need.
> 
> I'll try to not be a pain in the *.
> 
> adr.

For anyone interested, I've posted a review for adding
arm_drain_writebuf() and arm_sync_icache() calls to our libc, to be
compatible with the other *BSD systems...

https://reviews.freebsd.org/D20906

-- Ian