From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38647CE7AB2 for ; Mon, 25 Sep 2023 17:48:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230321AbjIYRsX (ORCPT ); Mon, 25 Sep 2023 13:48:23 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45336 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230230AbjIYRsW (ORCPT ); Mon, 25 Sep 2023 13:48:22 -0400 Received: from mail-pl1-x62e.google.com (mail-pl1-x62e.google.com [IPv6:2607:f8b0:4864:20::62e]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7CD77101 for ; Mon, 25 Sep 2023 10:48:15 -0700 (PDT) Received: by mail-pl1-x62e.google.com with SMTP id d9443c01a7336-1c0c6d4d650so61706925ad.0 for ; Mon, 25 Sep 2023 10:48:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=rivosinc-com.20230601.gappssmtp.com; s=20230601; t=1695664095; x=1696268895; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=V3tuJIIS1l1SOVzZtlVmqa55J+BZPRUyU2VUwqVvswg=; b=mWLJe+X2mp6TIEqIacDBG3NvBPzUhYGh+J3cGWEmK/YufkcCNHyWbFHEojC12NKRnP HdraPi3WjUYsDoWpM3/ONzuD3jxhs39lQAYlPfntg0ft85J9LpmsQdiuqnWwOvIjzySM A6a3gqvDTYbr9WgMWeO6NVHUf11NlkqQOyGXMbka36B0J/bUyK3Y6NK1eB0mLiyuJEDr Pkh9RJgrLEDiWmzdD69VAk7/LRmbV+YD+9o9ua2u/l6gCSNuGhaYzp0s1QZE5/Ii7iID 95r7BTF2T+fkV8D5ZnlmnX2BdmdMzlZi/tBXMKk7CnRck7ybC9eIRuubezDMX1hTsE/t UhPA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695664095; x=1696268895; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=V3tuJIIS1l1SOVzZtlVmqa55J+BZPRUyU2VUwqVvswg=; b=u7HEbKiWq43CvoV6gdhxjzKDd1MjqMSZyGFW724sZU6GBAnwctB9JT4YEUlCdIzuhu cbggVxERLWlGdUudfKtzNDEvyDUartJWamTUhys2ulVp6fQgVtKKAEhvR+az4kFqulgG nGF1Sv0GSibSNIvzxYgzUaNAAIqLMV01Wj513/ueJdMO3gH+/2UIZtDYHxJ4odHaaEN5 xOzqjfqxCO5536cn0aQIGhctSbBJxq6aQ6CmoUZFwcvqm06G8YjbZo/s6ab/BuVtH+VQ qFYeNTa4cnKnRg+QAQTXZufZE54cJgxcfJAR7Hay0uTfGzLnmJm1ES2O983cWIhJc3fO cOYw== X-Gm-Message-State: AOJu0YyUpxzV0v2yLlY+yQpgzsTfUo48WGLD+8y5bXNPXkqqp36rgmHy 6yO19XJct/bWu52c070jiqSRtg== X-Google-Smtp-Source: AGHT+IGvqV00K1g0/ZodkrKU5PL2uuUghZiRtw/5AJYE/blsphF6S3mDHOM5cs0FDHZM3+gOY2KwWg== X-Received: by 2002:a17:902:f548:b0:1c5:d354:93b6 with SMTP id h8-20020a170902f54800b001c5d35493b6mr8832777plf.67.1695664094936; Mon, 25 Sep 2023 10:48:14 -0700 (PDT) Received: from ghost ([50.221.140.188]) by smtp.gmail.com with ESMTPSA id s23-20020a170902989700b001c5de2f1686sm8260228plp.99.2023.09.25.10.48.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 25 Sep 2023 10:48:14 -0700 (PDT) Date: Mon, 25 Sep 2023 10:48:11 -0700 From: Charlie Jenkins To: Anup Patel Cc: Paolo Bonzini , Atish Patra , Palmer Dabbelt , Paul Walmsley , Conor Dooley , Rob Herring , Krzysztof Kozlowski , Shuah Khan , Andrew Jones , Mayuresh Chitale , devicetree@vger.kernel.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org Subject: Re: [PATCH v2 2/9] RISC-V: Detect XVentanaCondOps from ISA string Message-ID: References: <20230925133859.1735879-1-apatel@ventanamicro.com> <20230925133859.1735879-3-apatel@ventanamicro.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230925133859.1735879-3-apatel@ventanamicro.com> Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Mon, Sep 25, 2023 at 07:08:52PM +0530, Anup Patel wrote: > The Veyron-V1 CPU supports custom conditional arithmetic and > conditional-select/move operations referred to as XVentanaCondOps > extension. In fact, QEMU RISC-V also has support for emulating > XVentanaCondOps extension. > > Let us detect XVentanaCondOps extension from ISA string available > through DT or ACPI. > > Signed-off-by: Anup Patel > Reviewed-by: Andrew Jones > --- > arch/riscv/include/asm/hwcap.h | 1 + > arch/riscv/kernel/cpufeature.c | 1 + > 2 files changed, 2 insertions(+) > > diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h > index 0f520f7d058a..b7efe9e2fa89 100644 > --- a/arch/riscv/include/asm/hwcap.h > +++ b/arch/riscv/include/asm/hwcap.h > @@ -59,6 +59,7 @@ > #define RISCV_ISA_EXT_ZIFENCEI 41 > #define RISCV_ISA_EXT_ZIHPM 42 > #define RISCV_ISA_EXT_SMSTATEEN 43 > +#define RISCV_ISA_EXT_XVENTANACONDOPS 44 > > #define RISCV_ISA_EXT_MAX 64 > > diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c > index 3755a8c2a9de..3a31d34fe709 100644 > --- a/arch/riscv/kernel/cpufeature.c > +++ b/arch/riscv/kernel/cpufeature.c > @@ -182,6 +182,7 @@ const struct riscv_isa_ext_data riscv_isa_ext[] = { > __RISCV_ISA_EXT_DATA(svinval, RISCV_ISA_EXT_SVINVAL), > __RISCV_ISA_EXT_DATA(svnapot, RISCV_ISA_EXT_SVNAPOT), > __RISCV_ISA_EXT_DATA(svpbmt, RISCV_ISA_EXT_SVPBMT), > + __RISCV_ISA_EXT_DATA(xventanacondops, RISCV_ISA_EXT_XVENTANACONDOPS), > }; > > const size_t riscv_isa_ext_count = ARRAY_SIZE(riscv_isa_ext); > -- > 2.34.1 > > > _______________________________________________ > linux-riscv mailing list > linux-riscv@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-riscv I worry about storing vendor extensions in this file. Because vendor extensions are not standardized, they can only be expected to have the desired behavior on hardware with the appropriate vendor id. A couple months ago I sent a patch to address this by handling vector extensions independently for each vendor [1]. I dropped the patch because it relied upon Heiko's T-Head vector extension support that he stopped working on. However, I can revive this patch so you can build off of it. This scheme has the added benefit that vendors do not have to worry about conficting extensions, and the kernel does not have to act as a key registry for vendors. What are your thoughts? - Charlie [1] https://lore.kernel.org/lkml/20230705-thead_vendor_extensions-v1-2-ad6915349c4d@rivosinc.com/