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From:   Evan Green <evan@rivosinc.com>
Date:   Mon, 23 Oct 2023 09:21:28 -0700
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Subject: Re: [PATCH v2 02/19] riscv: add ISA extension parsing for scalar crypto
To:     =?UTF-8?B?Q2zDqW1lbnQgTMOpZ2Vy?= <cleger@rivosinc.com>
Cc:     linux-riscv@lists.infradead.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org,
        Palmer Dabbelt <palmer@rivosinc.com>,
        Paul Walmsley <paul.walmsley@sifive.com>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Albert Ou <aou@eecs.berkeley.edu>,
        Jonathan Corbet <corbet@lwn.net>,
        Andrew Jones <ajones@ventanamicro.com>,
        Conor Dooley <conor@kernel.org>,
        Samuel Ortiz <sameo@rivosinc.com>,
        Conor Dooley <conor.dooley@microchip.com>
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On Tue, Oct 17, 2023 at 6:15=E2=80=AFAM Cl=C3=A9ment L=C3=A9ger <cleger@riv=
osinc.com> wrote:
>
> From: Evan Green <evan@rivosinc.com>
>
> The Scalar Crypto specification defines Zk as a shorthand for the
> Zkn, Zkr and Zkt extensions. The same follows for both Zkn, Zks and Zbk,
> which are all shorthands for various other extensions. The detailed
> breakdown can be found in their dt-binding entries.
>
> Since Zkn also implies the Zbkb, Zbkc and Zbkx extensions, simply passing
> "zk" through a DT should enable all of Zbkb, Zbkc, Zbkx, Zkn, Zkr and Zkt=
.
> For example, setting the "riscv,isa" DT property to "rv64imafdc_zk"
> should generate the following cpuinfo output:
> "rv64imafdc_zicntr_zicsr_zifencei_zihpm_zbkb_zbkc_zbkx_zknd_zkne_zknh_zkr=
_zkt"
>
> riscv_isa_ext_data grows a pair of new members, to permit setting the
> relevant bits for "bundled" extensions, both while parsing the ISA string
> and the new dedicated extension properties
>
> Co-developed-by: Conor Dooley <conor.dooley@microchip.com>
> Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
> Signed-off-by: Evan Green <evan@rivosinc.com>
> Signed-off-by: Cl=C3=A9ment L=C3=A9ger <cleger@rivosinc.com>

My tree might be out of sync, but in my search for riscv_isa_ext, I
also found a use in print_isa() (cpu.c) where we're reaching into
riscv_isa_ext[].id and assuming it's always valid. If that's still in
there we'll want to fix up that spot too, since now with bundles .id
may or may not be valid.

-Evan