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

[Ian Campbell <Ian.Campbell@xxxxxxxxxx>]

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.

> 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.

Ian.


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