From patchwork Sat Feb 12 06:30:00 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tsukasa OI X-Patchwork-Id: 12744197 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8F2DFC433EF for ; Sat, 12 Feb 2022 06:30:31 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Mime-Version:References:In-Reply-To: Message-Id:Date:Subject:Cc:To:From:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=eZUQ40U95VBWyvosAHxRLqYcM8KZjfy872golmpoGAs=; b=XPhrrf6KXnvva6 0DpibXljHx2wBWwa83LStmfxhVmXIv43QZWYTnfCTczXLrWIwj9eprSbf/Rypmu7dCU0N7xVOp3qV IfVQdvCe3hdYFNRLAYvkrzF3X5gTzRVyI8Ajmr/n3JRwUBXqlyMzsl/oOrS3VdmtbjA+zI1w/Gmx9 Yp5V+eiH5dsxXj8q/WH3spAfgbnF+PWULJh/Xt47Q4VnX/cOCX/SPpv2ZixJqvFJL8M+NQf6+EqxY YKu2SEO0TG47X4yLP8Gnjg+/TNlJ1mRBUVk8aQqwd8FIPGyJ8bn0RJvo1h19I2xpZkDi9ly6L1HXu XxvC/rkyFwg/IoPCEuxA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nIlvL-009Uhu-I1; Sat, 12 Feb 2022 06:30:23 +0000 Received: from mail-sender-0.a4lg.com ([2401:2500:203:30b:4000:6bfe:4757:0]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nIlvH-009Uh4-2t for linux-riscv@lists.infradead.org; Sat, 12 Feb 2022 06:30:20 +0000 From: Tsukasa OI Authentication-Results: mail-sender-0.a4lg.com; dkim=permerror (bad message/signature format) To: Tsukasa OI , linux-riscv@lists.infradead.org Cc: Atish Patra , Anup Patel , Atish Patra Subject: [PATCH v3 2/3] RISC-V: Minimal parser for "riscv, isa" strings Date: Sat, 12 Feb 2022 15:30:00 +0900 Message-Id: In-Reply-To: References: Mime-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220211_223019_406731_3E83E26E X-CRM114-Status: GOOD ( 14.42 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org Current hart ISA ("riscv,isa") parser don't correctly parse: 1. Multi-letter extensions 2. Version numbers All ISA extensions ratified recently has multi-letter extensions (except 'H'). The current "riscv,isa" parser that is easily confused by multi-letter extensions and "p" in version numbers can be a huge problem for adding new extensions through the device tree. Leaving it would create incompatible hacks and would make "riscv,isa" value unreliable. This commit implements minimal parser for "riscv,isa" strings. With this, we can safely ignore multi-letter extensions and version numbers. Signed-off-by: Tsukasa OI [Improved commit text and fixed a bug around 's' in base extension] Signed-off-by: Atish Patra [Fixed workaround for QEMU] Signed-off-by: Tsukasa OI Tested-by: Heiko Stuebner --- arch/riscv/kernel/cpufeature.c | 66 ++++++++++++++++++++++++++++------ 1 file changed, 55 insertions(+), 11 deletions(-) diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index dd3d57eb4eea..9d5448542226 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -7,6 +7,7 @@ */ #include +#include #include #include #include @@ -66,7 +67,7 @@ void __init riscv_fill_hwcap(void) struct device_node *node; const char *isa; char print_str[NUM_ALPHA_EXTS + 1]; - size_t i, j, isa_len; + int i, j; static unsigned long isa2hwcap[256] = {0}; isa2hwcap['i'] = isa2hwcap['I'] = COMPAT_HWCAP_ISA_I; @@ -92,23 +93,66 @@ void __init riscv_fill_hwcap(void) continue; } - i = 0; - isa_len = strlen(isa); #if IS_ENABLED(CONFIG_32BIT) if (!strncmp(isa, "rv32", 4)) - i += 4; + isa += 4; #elif IS_ENABLED(CONFIG_64BIT) if (!strncmp(isa, "rv64", 4)) - i += 4; + isa += 4; #endif - for (; i < isa_len; ++i) { - this_hwcap |= isa2hwcap[(unsigned char)(isa[i])]; + for (; *isa; ++isa) { + const char *ext = isa++; + const char *ext_end = isa; + bool ext_long = false, ext_err = false; + + switch (*ext) { + case 's': + case 'x': + case 'z': + /** + * Workaround for invalid single-letter 's' (QEMU). + * It works until multi-letter extension starting + * with "Su" appears. + */ + if (*ext == 's' && ext[-1] != '_' && ext[1] == 'u') + break; + ext_long = true; + /* Multi-letter extension must be delimited */ + for (; *isa && *isa != '_'; ++isa) + if (!islower(*isa) && !isdigit(*isa)) + ext_err = true; + /* ... but must be ignored. */ + break; + default: + if (unlikely(!islower(*ext))) { + ext_err = true; + break; + } + /* Find next extension */ + if (!isdigit(*isa)) + break; + while (isdigit(*++isa)) + ; + if (*isa != 'p') + break; + if (!isdigit(*++isa)) { + --isa; + break; + } + while (isdigit(*++isa)) + ; + break; + } + if (*isa != '_') + --isa; /* - * TODO: X, Y and Z extension parsing for Host ISA - * bitmap will be added in-future. + * TODO: Full version-aware handling including + * multi-letter extensions will be added in-future. */ - if ('a' <= isa[i] && isa[i] < 'x') - this_isa |= (1UL << (isa[i] - 'a')); + if (ext_err || ext_long) + continue; + this_hwcap |= isa2hwcap[(unsigned char)(*ext)]; + this_isa |= (1UL << (*ext - 'a')); } /*