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[2620:137:e000::1:20]) by mx.google.com with ESMTP id 1-20020a630c41000000b005533750836fsi17823837pgm.421.2023.07.03.03.32.13; Mon, 03 Jul 2023 03:32:26 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@microchip.com header.s=mchp header.b=E+lyJZej; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=QUARANTINE sp=QUARANTINE dis=NONE) header.from=microchip.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231559AbjGCKab (ORCPT + 99 others); Mon, 3 Jul 2023 06:30:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:48652 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231571AbjGCKaF (ORCPT ); Mon, 3 Jul 2023 06:30:05 -0400 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.153.233]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4B1B9173C; Mon, 3 Jul 2023 03:29:34 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1688380175; x=1719916175; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=lVE/oaRwv4TRJvHt5T3XNlCrqoPFy2NcS4RQfVsdXa0=; b=E+lyJZejmMzER3qxziWSb5KeiZfvpRp4x+D3hzfJ6DnyMNJ2NQEE3eAH 7wuth/XgqKTcKCOaHBj4SDG06a7kjVgivHg2j/sBl+vAttUFEuYOOrWPn C474V6EZPyqT26uov70s9Xi8gk7NcP3LZV2dmLjNZUsQnhDjSlI6Y2P3b zq7PMIyvi7Dbod9BZdchfUmP5xBhT/KQ7EtgmBn6U/eJkiQrB6dmFfRBs X5qDD+PSbxwd0hfNmtntQqIgRZiug42uM+1kXyCfomw2PqNAFpsKzKF/t YwZ5Eku4xEvPa6j3KKERdgAu8O8ymkGyf26ykesZA22OzE/3gia/i0PhM w==; X-IronPort-AV: E=Sophos;i="6.01,177,1684825200"; d="scan'208";a="221754681" X-Amp-Result: SKIPPED(no attachment in message) Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa5.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 03 Jul 2023 03:29:31 -0700 Received: from chn-vm-ex03.mchp-main.com (10.10.85.151) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.21; Mon, 3 Jul 2023 03:29:29 -0700 Received: from wendy.microchip.com (10.10.115.15) by chn-vm-ex03.mchp-main.com (10.10.85.151) with Microsoft SMTP Server id 15.1.2507.21 via Frontend Transport; Mon, 3 Jul 2023 03:29:27 -0700 From: Conor Dooley To: CC: , , Rob Herring , Krzysztof Kozlowski , Paul Walmsley , Albert Ou , "Jonathan Corbet" , Andrew Jones , "Heiko Stuebner" , Evan Green , Sunil V L , , , , , Palmer Dabbelt Subject: [PATCH v3 11/11] RISC-V: provide Kconfig & commandline options to control parsing "riscv,isa" Date: Mon, 3 Jul 2023 11:28:03 +0100 Message-ID: <20230703-greedy-dividable-251fa2b809ac@wendy> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230703-repayment-vocalist-e4f3eeac2b2a@wendy> References: <20230703-repayment-vocalist-e4f3eeac2b2a@wendy> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=5379; i=conor.dooley@microchip.com; h=from:subject:message-id; bh=lVE/oaRwv4TRJvHt5T3XNlCrqoPFy2NcS4RQfVsdXa0=; b=owGbwMvMwCFWscWwfUFT0iXG02pJDCmLFq19sfNDxd5ZKzstu/hT0m4Kftl+W1isKaJn3ZtbCb2n vmcc6ihlYRDjYJAVU2RJvN3XIrX+j8sO5563MHNYmUCGMHBxCsBELjxh+J+29GBw/LWTOcJy1iX7L4 c3auh51LVVfZ2c+Y2rpvanuzcjw7QL+//2qvt91j50foPN033+LatCw9ouTc0xSz9Ypn+ukQcA X-Developer-Key: i=conor.dooley@microchip.com; a=openpgp; fpr=F9ECA03CF54F12CD01F1655722E2C55B37CF380C X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, SPF_HELO_PASS,SPF_NONE,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1770395109954836650?= X-GMAIL-MSGID: =?utf-8?q?1770395109954836650?= As it says on the tin, provide Kconfig option to control parsing the "riscv,isa" devicetree property. If either option is used, the kernel will fall back to parsing "riscv,isa", where "riscv,isa-base" and "riscv,isa-extensions" are not present. The Kconfig options are set up so that the default kernel configuration will enable the fallback path, without needing the commandline option. Suggested-by: Andrew Jones Suggested-by: Palmer Dabbelt Signed-off-by: Conor Dooley Reviewed-by: Andrew Jones --- Changes in v3: - Invert the Kconfig entry. It's now default y & not hidden by NONPORTABLE, but its entablement will now activate the fallback - Add a commandline option to enable the fallback on kernels that do not enable it in Kconfig, as Drew suggested - Default the global var to the Kconfig option & override it with the commandline one, rather than have checks for IS_ENABLED() and for the commandline option in riscv_fill_hwcap() & riscv_early_of_processor_hartid() --- .../admin-guide/kernel-parameters.txt | 7 +++++++ arch/riscv/Kconfig | 18 ++++++++++++++++++ arch/riscv/include/asm/hwcap.h | 1 + arch/riscv/kernel/cpu.c | 6 ++++++ arch/riscv/kernel/cpufeature.c | 14 +++++++++++++- 5 files changed, 45 insertions(+), 1 deletion(-) diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index d910fba25f2c..1bd435f60055 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -5437,6 +5437,13 @@ [KNL] Disable ring 3 MONITOR/MWAIT feature on supported CPUs. + riscv_isa_fallback [RISCV] + When CONFIG_RISCV_ISA_FALLBACK is not enabled, permit + falling back to detecting extension support by parsing + "riscv,isa" property on devicetree systems when the + replacement properties are not found. See the Kconfig + entry for RISCV_ISA_FALLBACK. + ro [KNL] Mount root device read-only on boot rodata= [KNL] diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 1d39efe2b940..a9a473b67182 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -841,6 +841,24 @@ config XIP_PHYS_ADDR be linked for and stored to. This address is dependent on your own flash usage. +config RISCV_ISA_FALLBACK + bool "Permit falling back to parsing riscv,isa for extension support by default" + default y + help + Parsing the "riscv,isa" devicetree property has been deprecated and + replaced by a list of explicitly defined strings. For compatibility + with existing platforms, the kernel will fall back to parsing the + "riscv,isa" property if the replacements are not found. + + Selecting N here will result in a kernel that does not use the + fallback, unless the commandline "riscv_isa_fallback" parameter is + present. + + Please see the dt-binding, located at + Documentation/devicetree/bindings/riscv/extensions.yaml for details + on the replacement properties of "riscv,isa-base" and + "riscv,isa-extensions". + endmenu # "Boot options" config BUILTIN_DTB diff --git a/arch/riscv/include/asm/hwcap.h b/arch/riscv/include/asm/hwcap.h index e3cda14a486b..b7b58258f6c7 100644 --- a/arch/riscv/include/asm/hwcap.h +++ b/arch/riscv/include/asm/hwcap.h @@ -81,6 +81,7 @@ struct riscv_isa_ext_data { extern const struct riscv_isa_ext_data riscv_isa_ext[]; extern const size_t riscv_isa_ext_count; +extern bool riscv_isa_fallback; unsigned long riscv_isa_extension_base(const unsigned long *isa_bitmap); diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c index 28d5af21f544..1acf3679600d 100644 --- a/arch/riscv/kernel/cpu.c +++ b/arch/riscv/kernel/cpu.c @@ -87,6 +87,12 @@ int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *har return 0; old_interface: + if (!riscv_isa_fallback) { + pr_warn("CPU with hartid=%lu is invalid: this kernel does not parse \"riscv,isa\"", + *hart); + return -ENODEV; + } + if (of_property_read_string(node, "riscv,isa", &isa)) { pr_warn("CPU with hartid=%lu has no \"riscv,isa-base\" or \"riscv,isa\" property\n", *hart); diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 2c4503fa984f..5945dfc5f806 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -471,6 +471,18 @@ static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap) return 0; } +#ifdef CONFIG_RISCV_ISA_FALLBACK +bool __initdata riscv_isa_fallback = true; +#else +bool __initdata riscv_isa_fallback; +static int __init riscv_isa_fallback_setup(char *__unused) +{ + riscv_isa_fallback = true; + return 1; +} +early_param("riscv_isa_fallback", riscv_isa_fallback_setup); +#endif + void __init riscv_fill_hwcap(void) { char print_str[NUM_ALPHA_EXTS + 1]; @@ -490,7 +502,7 @@ void __init riscv_fill_hwcap(void) } else { int ret = riscv_fill_hwcap_from_ext_list(isa2hwcap); - if (ret) { + if (ret && riscv_isa_fallback) { pr_info("Falling back to deprecated \"riscv,isa\"\n"); riscv_fill_hwcap_from_isa_string(isa2hwcap); }