On Mon, 19 Dec 2022 15:00:15 +0000, Mark Brown <broonie@xxxxxxxxxx> wrote: > > [1 <text/plain; us-ascii (7bit)>] > On Sun, Dec 18, 2022 at 01:11:01PM +0000, Marc Zyngier wrote: > > Akihiko Odaki <akihiko.odaki@xxxxxxxxxx> wrote: > > > > arch/arm64/tools/gen-sysreg.awk does not allow a hole and requires all > > > bits are described hence these descriptions. If you have an > > > alternative idea I'd like to hear. > > > I'd simply suggest creating an UNKNOWN field encompassing bits > > [21:28]. Alternatively, feel free to try the patch below, which allows > > you to describe these 4 bits as "Unkn 31:28", similar to Res0/Res1. > > I agree, where practical we should add new field types and other > features as needed rather than trying to shoehorn things into what the > tool currently supports. It is very much a work in progress which can't > fully represent everything in the spec yet. For things like the > registers with multiple possible views it's much more effort which > shouldn't get in the way of progress on features but with something like > this just updating the tool so we can match the architecture spec is the > right thing. I was tempted to add a Namespace tag that wouldn't generate the sysreg #defines, but only generate the fields with a feature-specific namespace. For example: Sysreg CCSIDR_EL1 3 1 0 0 0 Res0 63:32 Unkn 31:28 Field 27:13 NumSets Field 12:3 Associativity Field 2:0 LineSize EndSysreg Namespace CCIDX CCSIDR_EL1 Res0 63:56 Field 55:32 NumSets Res0 31:25 Field 24:3 Associativity Field 2:0 LineSize EndSysreg the later generating: #define CCIDR_EL1_CCIDX_RES0 (GENMASK(63, 56) | GENMASK(31, 25)) #define CCIDR_EL1_CCIDX_NumSets GENMASK(55, 32) #define CCIDR_EL1_CCIDX_Associativity GENMASK(24, 3) #define CCIDR_EL1_CCIDX_LineSize GENMASK(2, 0) Thoughts? > > > Define an 'Unkn' field type modeled after the Res0/Res1 types > > to allow such description. This allows the generation of > > I'd be tempted to spell out Unknown fully since Unkn is not such a > common abbreviation but I can see the desire to keep the name shorter > and it doesn't really matter so either way: > > Reviewed-by: Mark Brown <broonie@xxxxxxxxxx> Yeah, this stuff is write-only most of the time, and I like my fields aligned if at all possible. Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
