Stephen Warren <swarren@xxxxxxxxxxxxx> wrote @ Fri, 1 Nov 2013 17:54:37 +0100: > On 10/31/2013 02:17 AM, Hiroshi Doyu wrote: > > Stephen Warren <swarren@xxxxxxxxxxxxx> wrote @ Wed, 30 Oct 2013 23:33:32 +0100: > ... > > Right. > > "memory client ID" is used to find out MC_SMMU_<swgroup>_ASID_0 > > register. This register is used to associate <swgroup> to address > > space(AS). <swgroup> == H/W. <swgroup> can be attached to any AS. > > > >> Is "swgroup" simply another name for "memory client ID"? If so, it'd > >> be good to use just one term consistently. > > > > I used the name "memory client ID" because this ID can be used to find > > out HOTRESET bit in MC_CLIENT_HOTRESET_*_0 registers in addition to > > find the MC_SMMU_<swgroup>_ASID_0 offset. But maybe it's easy to use > > the consistent name as "swgroup". If laster HOTRESET wants automatic > > calculation they could borrow/redefine the same ID list, just > > replacing the prefix. What do you think? > > > >> Assuming "swgroup" is "memory client ID", > > > > Yes > > I took a look at the TRM, and it does look like there's a distinction > between client IDs and swgroups. The basic idea is that each swgroup > encompasses n (n >= 1) memory client IDs. So, we do have to use both terms. Well, I considred that memory-client's' ~= 'a' swgroup, and the term "swgroup" isn't used in HOTREST, where actually each bit represents a "swgroup". > However, the bits in the HOTRESET register appear mostly align with > swgroup IDs rather client IDs, so I think some of your explanation above > is innaccurate. > > I do want to point out that the HOTRESET bits don't 100% match the > swgroup IDs though, so the driver needs to be careful, and perhaps > contain some kind of mapping table between the two numbering spaces. In > particular, on Tegra114, swgroups and ASID registers appear in order > PPCS, <gap>, SATA, whereas there's no gap between the HOTRESET bits for > PPCS and SATA, assuming the TRM is correct. In our downstream, basically I provided to two conversion tables, one for "MC_SMMU_<swgroup ID>_ASID_0" and the other for "HOTRESET" bit. That table converts ID to them respectively. I think that this is acceptable. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
