[U-Boot] [RFC] ARM: rmobile: create DT memory nodes for R8A7795 3.0 and newer

[Ulrich Hecht]

On Fri, Jun 15, 2018 at 12:09 PM, Marek Vasut <marek.vasut at gmail.com> wrote:
>> +             arm_smccc_smc(ARM_SMCCC_RENESAS_MEMCONF,
>> +                           0, 0, 0, 0, 0, 0, 0, &res);
>
> Will this call work on platforms without patched ATF ?
> (I think not, don't you need to handle return value?)

I have not actually tested that, but if I understand the ATF code
correctly, unimplemented calls return
SMC_UNK (0xffffffff), which should be handled by the default case (NOP) below.

>
>> +             switch (res.a0) {
>> +             case 1:
>> +                     base[0] = 0x048000000ULL;
>> +                     size[0] = 0x038000000ULL;
>> +                     base[1] = 0x500000000ULL;
>> +                     size[1] = 0x040000000ULL;
>> +                     base[2] = 0x600000000ULL;
>> +                     size[2] = 0x040000000ULL;
>> +                     base[3] = 0x700000000ULL;
>> +                     size[3] = 0x040000000ULL;
>> +                     fdt_fixup_memory_banks(blob, base, size, 4);
>> +                     break;
>> +             case 2:
>> +                     base[0] = 0x048000000ULL;
>> +                     size[0] = 0x078000000ULL;
>> +                     base[1] = 0x500000000ULL;
>> +                     size[1] = 0x080000000ULL;
>> +                     fdt_fixup_memory_banks(blob, base, size, 2);
>> +                     break;
>> +             case 3:
>> +                     base[0] = 0x048000000ULL;
>> +                     size[0] = 0x078000000ULL;
>> +                     base[1] = 0x500000000ULL;
>> +                     size[1] = 0x080000000ULL;
>> +                     base[2] = 0x600000000ULL;
>> +                     size[2] = 0x080000000ULL;
>> +                     base[3] = 0x700000000ULL;
>> +                     size[3] = 0x080000000ULL;
>> +                     fdt_fixup_memory_banks(blob, base, size, 4);
>> +                     break;
>
> Obvious design question is -- since you're adding new SMC call anyway,
> can't the call just return the memory layout table itself, so that it
> won't be duplicated both in U-Boot and ATF ?

My gut feeling was to go with the smallest interface possible.

CU
Uli