linux-kernel - Re: [PATCH v1 0/2] RISC-V: Fixes for riscv_has_extension[un]likely()'s alternative dependency

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Message-Id: <168021016598.24378.3655010932034321812.b4-ty@rivosinc.com>
Date:   Thu, 30 Mar 2023 14:02:45 -0700
From:   Palmer Dabbelt <palmer@...osinc.com>
To:     Palmer Dabbelt <palmer@...belt.com>,
        Conor Dooley <conor.dooley@...rochip.com>
Cc:     Conor Dooley <conor@...nel.org>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Heiko Stuebner <heiko.stuebner@...ll.eu>,
        Andrew Jones <ajones@...tanamicro.com>,
        Anup Patel <apatel@...tanamicro.com>,
        Jisheng Zhang <jszhang@...nel.org>,
        "Jason A . Donenfeld" <Jason@...c4.com>,
        linux-riscv@...ts.infradead.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH v1 0/2] RISC-V: Fixes for
 riscv_has_extension[un]likely()'s alternative dependency


On Fri, 24 Mar 2023 10:05:37 +0000, Conor Dooley wrote:
> Here's my attempt at fixing both the use of an FPU on XIP kernels and
> the issue that Jason ran into where CONFIG_FPU, which needs the
> alternatives frame work for has_fpu() checks, could be enabled without
> the alternatives actually being present.
> 
> For the former, a "slow" fallback that does not use alternatives is
> added to riscv_has_extension_[un]likely() that can be used with XIP.
> Obviously, we want to make use of Jisheng's alternatives based approach
> where possible, so any users of riscv_has_extension_[un]likely() will
> want to make sure that they select RISCV_ALTERNATIVE.
> If they don't however, they'll hit the fallback path which (should,
> sparing a silly mistake from me!) behave in the same way, thus
> succeeding silently. Sounds like a
> 
> [...]

Applied, thanks!

[1/2] RISC-V: add non-alternative fallback for riscv_has_extension_[un]likely()
      https://git.kernel.org/palmer/c/1aa866931b80
[2/2] RISC-V: always select RISCV_ALTERNATIVE for non-xip kernels
      https://git.kernel.org/palmer/c/1ee7fc3f4d0a

Best regards,
-- 
Palmer Dabbelt <palmer@...osinc.com>