From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=205.220.180.131 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794137117; b=if34o0KSVCc18yULUlM3K0905NXt4k6Wly3KL+z/3NLyxVWcym4re+yGgzQHBLG90vjf sQWzOtLDbyhBDe0c+Ei3fMs3jGh6xK8Q1tRG9H2dJKYqEU/G+SXF5fVsqBC/X8j3z2rqE 1wxUtazFTWHpzLG2EYIU9mLth1At4X4woQkHB8mQx/6vNf78jsjFabTooZb9TRixQlqil ZT0/Oywt0MRa2OtHyBoU3e2eBDRRW7xZGlSW+S0UlPPiQpKRuSwISx/waJRh6myIM5rNF 1qXgOukjhXMc3OvF3T0hYTEANA7gSmov/ncTnaXZKb5d9KkFjMyCfv6A4SzYWVXn7UQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794137117; h=DMARC-Filter:Received:DKIM-Signature:Received:Received: DKIM-Signature:X-Google-DKIM-Signature:X-Forwarded-Encrypted: X-Gm-Message-State:X-Gm-Gg:X-Received:X-Received:Received:Date: Message-ID:From:To:Cc:Subject:In-Reply-To:References:Content-Type: Content-Transfer-Encoding:MIME-Version:X-Proofpoint-Spam-Details-Enc: X-Proofpoint-ORIG-GUID:X-Proofpoint-GUID:X-Proofpoint-Spam-Info: X-Authority-Analysis:X-Proofpoint-Virus-Version: X-Proofpoint-Spam-Details; bh=ZOlxpEI0OIo74XcS9Q0hNJZEahIo7Fytq0dNzWsexck=; b=vNrzy0UazXLXgStUOX4lmxhoUdRkZWlKvuzMH8Chaub+2Np95C7FFFrutThyAg91mE9S Qv4rbuOR4IUdnWVxM9G3O4NV+vU/x62ndbb8hAZencbtcboGP7JbwN9mxKCIlQx9VNjUd 2YZHk8kzKCnvnAaEtUKDMqXpGPa54RHZ34FHBT/6QnKJnKwNsX3fhCVPgDJc0GGpuq5hc sTO/AhcGgTC4q5jzqHuor8Sy3ti9yNyXG++IJ28GjBIEs/VSeg3YQFu3Zv9AGGmCDN3N4 E/m9OfWfYYcXQ5ezwHDEi2Z/dcmO0oE7kDvu1w0jycZX02/sGxSdAm4jmUyJ5hYWbqQ== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass header.from=oss.qualcomm.com; spf=pass smtp.mailfrom=oss.qualcomm.com; dkim=pass header.d=qualcomm.com header.i=@qualcomm.com header.a=rsa-sha256 header.s=qcppdkim1 header.b=n2aSSj9Q; dkim=pass header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.a=rsa-sha256 header.s=google header.b=ODAbYBg2; arc=none smtp.remote-ip=205.220.180.131 Received: from mx0b-0031df01.pphosted.com (mx0b-0031df01.pphosted.com [205.220.180.131]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1B362606A31C for ; Sun, 8 Nov 2026 11:25:16 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.2 smtp.subspace.kernel.org 1B362606A31C Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=oss.qualcomm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=qualcomm.com header.i=@qualcomm.com header.a=rsa-sha256 header.s=qcppdkim1 header.b=n2aSSj9Q; dkim=pass (2048-bit key, unprotected) header.d=oss.qualcomm.com header.i=@oss.qualcomm.com header.a=rsa-sha256 header.s=google header.b=ODAbYBg2 Received: from pps.filterd (m0279868.ppops.net [127.0.0.1]) by mx0a-0031df01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 6A8AgErs903725 for ; Sun, 8 Nov 2026 11:25:16 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=qualcomm.com; h= cc:content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=qcppdkim1; bh= ZOlxpEI0OIo74XcS9Q0hNJZEahIo7Fytq0dNzWsexck=; b=n2aSSj9QWWBGfjoH /6ASyY5Km7bvDf8ol+FKDZ7QSeLoFj83Mu/m9vsWMUh7LrbGH67EeTS53s5y8I6b t+a92NVAJe5RR/ZDhvBlBHQqk7JFBC4Ibm3gVf7dWn/+6dS9Exo2B5kioYGMUpbg MgiEWdClDk1myZNzYbnPu6oI6MjOAfoKV816baviwCom7ZQQXyH+7buwVaxEkJfw jak3svBvLYIqUBTSiZuIDPItiD53z1/NPr++NlAXrI1TTJX+2PQ9QZoN27Wa3GDT vkkKJR6+rEHsTwM/hVFk+JHchYRkd4mhMZ3ZbPuFCGwBo0PINmcPEM/b0qP7s6TO YGwoqQ== Received: from mail-yw1-f198.google.com (mail-yw1-f198.google.com [209.85.128.198]) by mx0a-0031df01.pphosted.com (PPS) with ESMTPS id 4hsuagtvy3-1 (version=TLSv1.3 cipher=TLS_AES_128_GCM_SHA256 bits=128 verify=NOT) for ; Sun, 08 Nov 2026 11:25:15 +0000 (GMT) Received: by mail-yw1-f198.google.com with SMTP id 00721157ae682-8b0e878f574so1211597b3.1 for ; Sun, 08 Nov 2026 03:25:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oss.qualcomm.com; s=google; t=1794137115; x=1794741915; darn=vger.kernel.org; h=mime-version:content-transfer-encoding:content-type:references :in-reply-to:subject:cc:to:from:message-id:date:from:to:cc:subject :date:message-id:reply-to:content-type; bh=ZOlxpEI0OIo74XcS9Q0hNJZEahIo7Fytq0dNzWsexck=; b=ODAbYBg2D+QTGzoJ4KsdcRAxHi9hrFTl+zkdBK1ebtWTdYT8NCqE5Tl+Fz2BZ5Rltj 7USSDkVW21ie/ZzKjV8P8tDpe7uq/992XYsQ7fBUEHTqWiwbv+YmUEtVr/6suMzquGiW fT5ugFIpSKFTv/8poFokVAYDGvinfJ9ICkkhmhLcp+0gbbro6PKvcYUiB5tvoZbz9cm1 gOJZ74156Qmk/8NA6p5lb9hPTmG7G6lY2aye7eDSlIHhkJqSI9fVmlNcyvvHuvSpOlS4 ESEUXrVAXzHuLsxJnNvMMxDzZG94bHNvGUau4MS9A77mDUPaUENz+k3QjrRo8Rvzy5FS Vn9g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1794137115; x=1794741915; h=mime-version:content-transfer-encoding:content-type:references :in-reply-to:subject:cc:to:from:message-id:date:x-gm-gg :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to :content-type; bh=ZOlxpEI0OIo74XcS9Q0hNJZEahIo7Fytq0dNzWsexck=; b=ESVhSw6rcToC1TTj6M7CffokdCSq3E5zB99AnnQSATLwElkgxCXnS11/CA3QPa5/Ls GXzBiTpbvEZjYZMsPb8k/kieRPehlvvlrOmn1KpURYyn0Dm9TF9aTbtdr8e6YdLwq9vZ 6XnZkDY4uUUGrCP17ZsCZrKL7SQIKGgAVAaXeuYSVDclBeVEJQYnMpxfMJIU1d3u9ojk ILBQyRiv10EGzVR0Y/YBNQdEfachvS1yNq2+PMDzlhaLsdeE0C0X5Gv5ehZnqW20x1KB ANGiG+sR7EF8BJma9cL0KILW7/8e9sTh2/Pk39CBdfrohJoAuLpDaanzgmKD3c+vX763 HUOw== X-Forwarded-Encrypted: i=1; AL+hErGOlZnq3+WgvBx7XFJXpGEz/FzXmLpe0obR+RgBH09Aw+UleULkWrY0ojgXI0RaFhSfZ+0GYRF7Mvd+lvc=@vger.kernel.org X-Gm-Message-State: APuU4Z9KjLYKMbtFFuqcHy7XdBzX0BZRLsLS2OeeVY3yw0Jtpu8uZlgy nIu5evF2wy7AUvcb9GfJ2hcWWpYYNTuCDqDSiYIDqEZx9w+EAl+ujQ+eJyZ+N27z7lGCEZ078KU hfp79mr8yqW70+jkdtbSZmQejmJzuJssWL1tYQzw74BHYXLgEyQ9W/dnHlJX0eWHLrh0= X-Gm-Gg: AYBFou28lW3EnZ9ytY+n26QPMNVrHYfyztp7BzXqlVX9+nBnmD4Eh2Q5kFKIm62YgUG yE2XHEmQje1VxmUPwmgTCC2PUrUjOhHCtq/4Q5x6Qe2j09yxVJGQur7e8qnfRHzZmuFFr4ZdXbn lL9kJJDl/8QYhgJIv+VcQ5SEq6eiPBrY3+ze05m92EIgDoUYVMxylpalk/SX573azspd5y3pw1a RKrxeuhIoRY9bfIfxXbuPlHmrqExXO0CGkJHfOqyAAg8vx17Msw0NIlrP/seNXWjyRTBjqiNtZF r/vJImyz/1TEMAGRXmxG5xC36a78Yw6X/LFHVvxQfsmbnqqmX0D+n1vCVQKEZazjDACh5hUvv1J NRfIUXX0smKw1ftYs46MYjUM1iHg1MyZAeRGYiVu2mW/YUWRzk7oZYIup54jxzn+jBYsXGcUf5u 7PqoL8kpxrew== X-Received: by 2002:a05:690c:dd4:b0:8b0:cd32:b8dd with SMTP id 00721157ae682-8b3566c7e2amr25150807b3.17.1794137115018; Sun, 08 Nov 2026 03:25:15 -0800 (PST) X-Received: by 2002:a05:690c:dd4:b0:8b0:cd32:b8dd with SMTP id 00721157ae682-8b3566c7e2amr25150737b3.17.1794137114479; Sun, 08 Nov 2026 03:25:14 -0800 (PST) Received: from localhost ([120.244.9.94]) by smtp.gmail.com with ESMTPSA id 00721157ae682-8b36bc57e8bsm12483067b3.32.2026.11.08.03.25.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 08 Nov 2026 03:25:13 -0800 (PST) Date: Sun, 08 Nov 2026 06:24:53 -0500 Message-ID: <4879567e977e3f5023c6e7ddca133b1a.guodong.xu@oss.qualcomm.com> From: Guodong Xu To: Radim =?utf-8?b?S3LEjW3DocWZ?= Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org, Paul Walmsley , Palmer Dabbelt , Alexandre Ghiti , Samuel Holland , Andy Chiu , Zong Li , Charlie Jenkins Subject: Re: [PATCH 4/6] riscv: hwprobe: Report Supm only when available In-Reply-To: <20261006075303.205216-5-radim.krcmar@oss.qualcomm.com> References: <20261006075303.205216-1-radim.krcmar@oss.qualcomm.com> <20261006075303.205216-5-radim.krcmar@oss.qualcomm.com> Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 8bit X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYxMTA4MDA0NSBTYWx0ZWRfX0gH8rEfYPmDr L9gAHltHFGupkk93OYIFhAKOe9Z2pB145miL5x0+bKqRWws4ImBeRzlv2nxjq9dVbhpTYSv3+Nh mao0uDiZdXgCHZXLUOm2DY9tvh9QN5QyADMzROg4TiCGH1QB/CSFJZfB+WSDzNGYtiyj2BFoyoB 4U59ad3+5YTQtD9sIvzOMv1zt5rxhXJZvTtFhIkXVrStcXZy3GykqmqgOUnB7lP7CyqhAoPbLm1 9JNAetV5bQR8x4mo6JevYb8QbF5doT70i4q2bhMBIplyCmO/OdYaSDoihP0gs9SDVYWYkJiSqdV mB0wQZWkyaM/QBzvtaKKBsgvLyLhn2A1S/nuN8SmgyQr4huT3mcKiXxZV9HEMD/djqRJ8XmPW6m tpnOz58ilO7NDvLFREhtcX8S7Yykrm46HevGkbNwLBkTewfpR1vpcGZB806U8YcYPlGtrQp55Fa svTa1DqrvJfHUOs8UNg== X-Proofpoint-ORIG-GUID: zq1n3DPCCfh_TDyPeh_2y2Xl0SssroiC X-Proofpoint-GUID: zq1n3DPCCfh_TDyPeh_2y2Xl0SssroiC X-Proofpoint-Spam-Info: AW1haW4tMjYxMTA4MDA0NSBTYWx0ZWRfXzqR2TQ4s/JWU 10MAn3GgWqQhOs0EFiu8A7SEzPMUYGOyqd4kQ/5yMmPS5IyAJODUmHUDVcnOez6LAOP2l1n0z8J qG8ryAdwfR4Ib7IzYZMni6Yti8tBydo= X-Authority-Analysis: v=2.4 cv=V8LoQuni c=1 sm=1 tr=0 ts=6af05c1b cx=c_pps a=g1v0Z557R90hA0UpD/5Yag==:117 a=ZvHX9x23NDWH3CQeJ2oX1w==:17 a=IkcTkHD0fZMA:10 a=zJRp6_cAMcgA:10 a=s4-Qcg_JpJYA:10 a=VkNPw1HP01LnGYTKEx00:22 a=u7WPNUs3qKkmUXheDGA7:22 a=ZpdpYltYx_vBUK5n70dp:22 a=VwQbUJbxAAAA:8 a=EUspDBNiAAAA:8 a=NCzzBX7O5BTftGYIIH0A:9 a=QEXdDO2ut3YA:10 a=MFSWADHSvvjO3QEy5MdX:22 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1176,Hydra:6.1.138,FMLib:17.12.100.49 definitions=2026-11-08_04,2026-11-06_01,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 clxscore=1015 malwarescore=0 bulkscore=0 impostorscore=0 phishscore=0 adultscore=0 lowpriorityscore=0 priorityscore=1501 spamscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2611040001 definitions=main-2611080045 Hi Radim, On Tue, 6 Oct 2026 09:53:01 +0200, Radim Krcmar wrote: > The RISC-V ISA defines Supm as > > "An extension that indicates that there is pointer-masking support > available in user mode, with some facility provided in the application > execution environment to control pointer masking." > > Our facility always returns -EINVAL unless Supm support is configured, > the pointer masking ISA extension is globally present, and the user-mode > is running in 64-bit mode. > > Hiding Supm in compat tasks would add complexity that doesn't seem > justified as 32-bit code has no reason to look at Supm anyway. > Reporting based on the a global sysctl toggle isn't done. > > Do not report Supm when some harts lack the extension, because it's not > available on any hart in that case. > > (Reporting Supm when only PMLEN=0 is supported isn't great, but doesn't > violate the text of the extension and we ought to have Supm7 and Supm16 > extensions if we care about precision.) Since the kernel already knows whether that is the case, could this block use riscv_have_user_pmlen() instead (55458c7347a3 "riscv: Add a getter for user PMLEN support")? It exposes the have_user_pmlen_* flags that set_tagged_addr_ctrl() consults, so hwprobe would report Supm only when the prctl can actually enable a non-zero PMLEN: /* PMM=0 is "disabled"; Supm is usable only with a non-zero PMLEN. */ if (riscv_have_user_pmlen(7) || riscv_have_user_pmlen(16)) pair->value |= RISCV_HWPROBE_EXT_SUPM; That also replaces both tests in the block above. 1) IS_ENABLED(CONFIG_RISCV_ISA_SUPM) is covered because the getter is a static inline returning false when the option is off. 2) riscv_isa_extension_available(NULL, SUPM) is covered because tagged_addr_init() returns before probing PMLEN unless Supm is present on every hart, so both flags stay false. 7 and 16 are the only PMLEN values the current standard defines (one PMM encoding is reserved for future values). The RVA23 profile v1.0 requires "Supm: Pointer masking, with the execution environment providing a means to select PMLEN=0 and PMLEN=7 at minimum", and senvcfg.PMM=0 is defined as "Pointer masking is disabled (PMLEN = 0)". That is why the rva23u64 base behavior key in my series [1] checks riscv_have_user_pmlen(7), and v9 will keep that. But for hwprobe's own Supm bit the getter seems the better fit than waiting for Supm7/Supm16. Guodong [1] https://lore.kernel.org/linux-riscv/20260920-rva23u64-hwprobe-v2-v8-11-5f14bc5c23d3@oss.qualcomm.com/