Re: [Xen-devel] [PATCH v4 1/1] Support Odroid-XU board (Exynos 5410)

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

On Thu, 2014-09-04 at 08:44 -0700, Suriyan Ramasami wrote:
> On Thu, Sep 4, 2014 at 1:58 AM, Ian Campbell <Ian.Campbell@xxxxxxxxxx> wrote:
> > On Wed, 2014-09-03 at 10:55 -0700, Suriyan Ramasami wrote:
> >> On Wed, Sep 3, 2014 at 3:03 AM, Ian Campbell <Ian.Campbell@xxxxxxxxxx> 
> >> wrote:
> >> > On Wed, 2014-08-27 at 12:27 -0700, Suriyan Ramasami wrote:
> >> >> On Tue, Aug 26, 2014 at 2:01 PM, Ian Campbell <ian.campbell@xxxxxxxxxx> 
> >> >> wrote:
> >> >> > On Tue, 2014-08-19 at 16:19 -0700, Suriyan Ramasami wrote:
> >> >> >> +static int __init exynos5250_smp_init(void)
> >> >> >> +{
> >> >> >> +    return exynos_smp_init(EXYNOS5250_PA_SYSRAM);
> >> >> >> +}
> >> >> >> +
> >> >> >> +static int __init exynos5_smp_init(void)
> >> >> >> +{
> >> >> >> +    struct dt_device_node *node;
> >> >> >> +    u64 sysram_ns_base_addr;
> >> >> >> +    u64 size;
> >> >> >> +    int rc;
> >> >> >> +
> >> >> >> +    node = dt_find_compatible_node(NULL, NULL, 
> >> >> >> "samsung,exynos4210-sysram-ns");
> >> >> >
> >> >> >
> >> >> > Looking at Documentation/devicetree/bindings/arm/exynos/smp-sysram.txt
> >> >> > in the Linx tree it seems that this node is supposed to be present on
> >> >> > all systems, including 5250 and it seems to be present in all the 
> >> >> > DTBs I
> >> >> > can see.
> >> >> >
> >> >> > IOW I think exynos5_smp_init and exynos5250_smp_init can just be
> >> >> > exynos5_smp_init (perhaps even folding in exynos_smp_init too).
> >> >> >
> >> >> It definitely can be folded in, but as you have mentioned later on in
> >> >> this email that Exynos5250 will stop booting cause of the erroneous
> >> >> value of 0x204f000 instead of 0x2020000. If this is folded in, then
> >> >> the arndale DT should be possibly corrected for it to play well with
> >> >> XEN.
> >> >
> >> > I think this is already done, looking at v3.16-rc6 (just because I had
> >> > it checked out) arch/arm/boot/dts/exynos5250.dtsi has:
> >> >         sysram@02020000 {
> >> >                 compatible = "mmio-sram";
> >> >                 reg = <0x02020000 0x30000>;
> >> >                 #address-cells = <1>;
> >> >                 #size-cells = <1>;
> >> >                 ranges = <0 0x02020000 0x30000>;
> >> >
> >> >                 smp-sysram@0 {
> >> >                         compatible = "samsung,exynos4210-sysram";
> >> >                         reg = <0x0 0x1000>;
> >> >                 };
> >> >
> >> >                 smp-sysram@2f000 {
> >> >                         compatible = "samsung,exynos4210-sysram-ns";
> >> >                         reg = <0x2f000 0x1000>;
> >> >                 };
> >> >         };
> >> >
> >>
> >> I am a little confused here. We are using - compatible =
> >> "samsung,exynos4210-sysram-ns" to pull the value for
> >> sysram_ns_base_addr in function exynos5_smp_init(). I believe with the
> >> exynos5250 DT you have quoted above, wouldn't that add up to 2020000 +
> >> 2f000? (which is not what we want for the arndale?) I shall wait on
> >> your thoughts on this.
> >
> > I think I mentioned this upthread. At the time I had no idea why but
> > looking again:
> >
> > DT has 0x0204f000 whereas we are hardcoding 0x02020000. The DT lists
> > 0x2020000 as the secure sysram. Aha! Looks like this was wrongly
> > converted by:
> >
> >         4557c2292854d047ba8e44a69e2d60d99533d155
> >         Author: Ian Campbell <ian.campbell@xxxxxxxxxx>
> >         Date:   Thu Aug 29 16:25:00 2013 +0100
> >
> >             xen: arm: rewrite start of day page table and cpu bring up
> >
> > which moved the CPU kick from secure mode to NS mode. Has SMP on arndale
> > been broken since then? Probably.
> >
> 
> So, it does make sense to fold it in and get rid of the 0x02020000
> hardcoded value for Arndale. Right?

Correct.

> I shall push a version 6 with this change.

Thanks.

> 
> >> On the same train of thought, it would seem that EXYNOS5_MCT_BASE
> >> should also be extracted from the DT (in function exynos5_init_time).
> >
> > Ideally, yes.
> >
> This has been incorporated in version 5 of the patch.
> Thanks!
> 
> > Ian.
> >



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