On Mon, Aug 02, 2021 at 02:54:22AM +0200, Marek Vasut wrote:
> On 7/29/21 6:58 PM, Tom Rini wrote:
>
> [...]
>
> > > > so when did rcar3 introduce something there that shouldn't be
> > > > reserved? And you had phrased this to me on IRC as about reserving spot
> > > > for ATAGS, and that not being needed of course on arm64. But that's not
> > > > what's going on. Perhaps the answer is that rcar3 needs to introduce a
> > > > board_lmb_reserve to free the normal arch one and provide whatever more
> > > > narrow scope it needs.
> > >
> > > Based on the commit message 2359fa7a878 ("arm: bootm: Disable LMB
> > > reservation for command line and board info on arm64") , this is about
> > > ATAGS
> > > and we really don't need to reserve those on arm64.
> >
> > Commit 2359fa7a878 disables the entire arch_lmb_reserve function on
> > aarch64, yes. I assumed when we had talked that it was a small area
> > being set aside and perhaps mis-recalled that ATAGS tended to live at
> > DDR_BASE + 0x800 or so.
>
> That arch_lmb_reserve() is responsible for reserving architecture specific
> memory. On arm32 it is ATAGS, on arm64 it is nothing as far as I can tell
> (and see below regarding the TLB).I don't think that LMB ever covered ATAGS. ATAGS, I could have sworn, were at start of memory + 0x800 or so. This LMB is for the top of memory where U-Boot is. -- Tom
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