Re: [RFC PATCH 3/7] riscv: Simplify MAXPHYSMEM config

[Alex Ghiti]

On 4/3/20 11:53 AM, Palmer Dabbelt wrote:
> On Sun, 22 Mar 2020 04:00:24 PDT (-0700), alex@xxxxxxxx wrote:
> > Either the user specifies maximum physical memory size of 2GB or the
> > user lives with the system constraint which is 128GB in 64BIT for now.
> >
> > Signed-off-by: Alexandre Ghiti <alex@xxxxxxxx>
> > ---
> > Âarch/riscv/Kconfig | 20 ++++++--------------
> > Â1 file changed, 6 insertions(+), 14 deletions(-)
> >
> > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> > index 8e4b1cbcf2c2..a475c78e66bc 100644
> > --- a/arch/riscv/Kconfig
> > +++ b/arch/riscv/Kconfig
> > @@ -104,7 +104,7 @@ config PAGE_OFFSET
> > ÂÂÂÂ default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
> > ÂÂÂÂ default 0x80000000 if 64BIT && !MMU
> > ÂÂÂÂ default 0xffffffff80000000 if 64BIT && MAXPHYSMEM_2GB
> > -ÂÂÂ default 0xffffffe000000000 if 64BIT && MAXPHYSMEM_128GB
> > +ÂÂÂ default 0xffffffe000000000 if 64BIT && !MAXPHYSMEM_2GB
> >
> > Âconfig ARCH_FLATMEM_ENABLE
> > ÂÂÂÂ def_bool y
> > @@ -216,19 +216,11 @@ config MODULE_SECTIONS
> > ÂÂÂÂ bool
> > ÂÂÂÂ select HAVE_MOD_ARCH_SPECIFIC
> >
> > -choice
> > -ÂÂÂ prompt "Maximum Physical Memory"
> > -ÂÂÂ default MAXPHYSMEM_2GB if 32BIT
> > -ÂÂÂ default MAXPHYSMEM_2GB if 64BIT && CMODEL_MEDLOW
> > -ÂÂÂ default MAXPHYSMEM_128GB if 64BIT && CMODEL_MEDANY
> > -
> > -ÂÂÂ config MAXPHYSMEM_2GB
> > -ÂÂÂÂÂÂÂ bool "2GiB"
> > -ÂÂÂ config MAXPHYSMEM_128GB
> > -ÂÂÂÂÂÂÂ depends on 64BIT && CMODEL_MEDANY
> > -ÂÂÂÂÂÂÂ bool "128GiB"
> > -endchoice
> > -
> > +config MAXPHYSMEM_2GB
> > +ÂÂÂ bool "Maximum Physical Memory 2GiB"
> > +ÂÂÂ default y if 32BIT
> > +ÂÂÂ default y if 64BIT && CMODEL_MEDLOW
> > +ÂÂÂ default n
> >
> > Âconfig SMP
> > ÂÂÂÂ bool "Symmetric Multi-Processing"
>
> I'm not sure this actually helps with anything, but if it's all going 
> away then it's
> fine. Originally the 2G/128G stuff was there to allow for larger VA 
> spaces in
> the future.

With runtime sv48 introduction, whatever we would have used here could 
have been wrong at runtime, so removing it was easier.

Alex