Re: [PATCH v17 02/10] of: Add a common kexec FDT setup function

[Lakshmi Ramasubramanian]

On 2/10/21 9:23 AM, Rob Herring wrote:
> On Tue, Feb 09, 2021 at 10:21:52AM -0800, Lakshmi Ramasubramanian wrote:
> > From: Rob Herring <robh@xxxxxxxxxx>
> >
> > Both arm64 and powerpc do essentially the same FDT /chosen setup for
> > kexec.  The differences are either omissions that arm64 should have
> > or additional properties that will be ignored.  The setup code can be
> > combined and shared by both powerpc and arm64.
> >
> > The differences relative to the arm64 version:
> >   - If /chosen doesn't exist, it will be created (should never happen).
> >   - Any old dtb and initrd reserved memory will be released.
> >   - The new initrd and elfcorehdr are marked reserved.
> >   - "linux,booted-from-kexec" is set.
> >
> > The differences relative to the powerpc version:
> >   - "kaslr-seed" and "rng-seed" may be set.
> >   - "linux,elfcorehdr" is set.
> >   - Any existing "linux,usable-memory-range" is removed.
> >
> > Combine the code for setting up the /chosen node in the FDT and updating
> > the memory reservation for kexec, for powerpc and arm64, in
> > of_kexec_alloc_and_setup_fdt() and move it to "drivers/of/kexec.c".
> >
> > Signed-off-by: Rob Herring <robh@xxxxxxxxxx>
> > Signed-off-by: Lakshmi Ramasubramanian <nramas@xxxxxxxxxxxxxxxxxxx>
> > ---
> >   drivers/of/Makefile |   6 ++
> >   drivers/of/kexec.c  | 258 ++++++++++++++++++++++++++++++++++++++++++++
> >   include/linux/of.h  |  13 +++
> >   3 files changed, 277 insertions(+)
> >   create mode 100644 drivers/of/kexec.c


> > diff --git a/include/linux/of.h b/include/linux/of.h
> > index 4b27c9a27df3..f0eff5e84353 100644
> > --- a/include/linux/of.h
> > +++ b/include/linux/of.h
> > @@ -560,6 +560,19 @@ int of_map_id(struct device_node *np, u32 id,
> >   
> >   phys_addr_t of_dma_get_max_cpu_address(struct device_node *np);
> >   
> > +/*
> > + * Additional space needed for the buffer to build the new FDT
> > + * so that we can add initrd, bootargs, kaslr-seed, rng-seed,
> > + * userable-memory-range and elfcorehdr.
> > + */
> > +#define FDT_EXTRA_SPACE 0x1000
>
> No need for this to be public now. Move it to of/kexec.c.

Will do.

 -lakshmi