From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B2D6D63B9 for ; Mon, 23 Mar 2026 04:45:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774241116; cv=none; b=DVwODa7ywSwq30ya9IuWmo/YysPH0UysybHpxBeRbd1OPTwuCKwZhIlpjwizKJWu0Ir1VPSi9EfBplpSJ8Zh25af3BvUmIRhphfAEIG2WgFTPJP+6BljY4+ayCBmXXUfyyn/yalzBxlrfvGrfGk5qSV9LaCytdo+EmkFD29UwzE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774241116; c=relaxed/simple; bh=TlyCAWysWztqJphkgOF0JdYCt4KjGxEf6BKnZUwtClo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Bz2MYjiNbFTcq5Ptqyi8mlhH8wFg9+McCMm3IVpDeaBXGczaG2EdnuXropzmXSnOrmkAOoletBpVncW2bi2OPTuhUsJShl+cULAynLlCCNiLWNBg7N7r0/eQOGq7J4yX/vAfEIl5AhkGr9HetVufu2QyA4g3kz1pvj/YMS1rMNQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=gF2g8t8G; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=SxeOhvgg; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="gF2g8t8G"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="SxeOhvgg" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774241114; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=tKHlNzVZ8flcJLfDOJhZcXKBIi7eEiUriVf/nusyPOU=; b=gF2g8t8GnxFCVfhq7Mx4m2WOiBaUtavRJIIHpGL5U/J8qFSTrRU2bjxh25vRRebRyfIWpo c3S8H/Q9+vXJlfad8H9wGM57qPPuK+XRCmY9yIyr8068mg29fAFGWYrQXV7kNO+Mn+3YgZ OhDOgGpxQasXvcq6uNYGvKGwBxZQnKs= Received: from mail-pl1-f197.google.com (mail-pl1-f197.google.com [209.85.214.197]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-607-wOXLPhuiOh2sT0H6vF0VHQ-1; Mon, 23 Mar 2026 00:45:13 -0400 X-MC-Unique: wOXLPhuiOh2sT0H6vF0VHQ-1 X-Mimecast-MFC-AGG-ID: wOXLPhuiOh2sT0H6vF0VHQ_1774241112 Received: by mail-pl1-f197.google.com with SMTP id d9443c01a7336-2b064f043adso53692325ad.0 for ; Sun, 22 Mar 2026 21:45:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1774241112; x=1774845912; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=tKHlNzVZ8flcJLfDOJhZcXKBIi7eEiUriVf/nusyPOU=; b=SxeOhvggRMDifAri0o5SKvCqJU0R9JBSVOjfxHXdEbo7kJfIXCOXPRW5ronoAfdIG1 BbQ2QOeSRHt1bMm/qFJL90cpoARFQkC6ksEjdD1tjRB3d9U2sQwxKfDUwVd/CsW6ZM9t jVyQZtDaYkCmjd9X6GDtJppBhOj1rJMcAnw0RCIVUB4D5mH57GNpskIjtKGytXkgXhjm shFr1CwAlwbFRTP+1V/HzLxkFA8tCPNm0+WDiMJI8Ep/O/qSGudHHtEaJT4Kmse4lLHg 88SHu+Pgfl8rAI7//TKUUyUPv2SECgV67INXbT3fJyygntW5JDl9y/Dp1P042N9F11Ms C3eA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774241112; x=1774845912; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=tKHlNzVZ8flcJLfDOJhZcXKBIi7eEiUriVf/nusyPOU=; b=Dsi9eA/neDrr/UTKRUZxNgM+UUhmI9ZQbBfNs3QPH9miNgITSToQ1lfiaUovY8ZUZr paRFxC8OvqpMhdKSGM4yF3JoT7d5Xk+xOGVFPVoOlXB+4rpLb0c4LEOU/vB/st6e1nGC 8MFRrjnut8l7mgmgqe/r0bQqZ5hUdNuBRy6bcrdTL0hYkJwYAaoS5mgvxyAKNZERyusM qqApvrSjew/r6HMisLBrSPEBmSvR5EOmw4fZdw88VPWbielP7ST0TS24vK0D2toDytYH mw8a/QYrj/b01nsfNhsSOroKPspuMtEe5CaNWvCo66zljH/KL3yeYjivAXELB4GDF1rJ xfdw== X-Forwarded-Encrypted: i=1; AJvYcCVXr/ehzB/yW/iCmzW85lrVf64O8Pt8ZtrOuUUJDe6YFmWHgC58WSsmWd7SpYZP67Dbm2CdbBvAlNmxK5Q=@vger.kernel.org X-Gm-Message-State: AOJu0YwGtKCUT4NR6PHc7bfy9y+2JQpFQoZ+GFX9POEpk5/W685h5FQ+ 2cQaTJEB4eGOp5BBLCsUlHv8GnY0ByzFaM5PImJmQgtvSO+v5C56fbhEC6o95z8xI29r6fpa01V M2ENxkc0V6QnDtL6WoVKqWJR2I9PPt+bMbwo7icmkH1Vg0X3c8c9l07Cb8xWc0hauuw== X-Gm-Gg: ATEYQzxslTZ5XRbLls7qnGxNqHC/MrB4dgdPlDDLqctwQEvGSQoyw7eya5PYw2vVCm9 53c5zbMbqRMZraBOVWRRoQ/HfA8Fi/dK681EahCM3v8Vw4qEIrWB7vK2AiqxpAUebp2b8SbrHKQ zx3yxcsYtAqHHjQsZJ55Bbaed/o5PfZBlx0K6MsTclMxGYxc+B5QD0ThcpUQaa1Bmq7U6zp/I/N cfS0pXJ7M3vrikBUij14FJxJMjVKxxUmcCvRrEPYClyB1Mtw61Hj1DtWFzZiDeTCr8DFIEOEwaF iKqsALvVSbc7OLEhE9PKD2ZKEpXIjTaH3JUyg8pDjP9po2sZhqXBe91/CzLzUGdaIoo1w9LKsN7 Tqz8AbB+99jB2FlIPyyyF7L7utACQCx1I521yAhhubNC54KmvkRe/LdZzu+62vEtG X-Received: by 2002:a17:903:244f:b0:2ae:6192:8d78 with SMTP id d9443c01a7336-2b0826c7097mr103436085ad.1.1774241112008; Sun, 22 Mar 2026 21:45:12 -0700 (PDT) X-Received: by 2002:a17:903:244f:b0:2ae:6192:8d78 with SMTP id d9443c01a7336-2b0826c7097mr103435595ad.1.1774241111581; Sun, 22 Mar 2026 21:45:11 -0700 (PDT) Received: from [192.168.68.51] (n175-34-8-244.mrk21.qld.optusnet.com.au. [175.34.8.244]) by smtp.gmail.com with ESMTPSA id d9443c01a7336-2b08369e41csm96333595ad.74.2026.03.22.21.44.59 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 22 Mar 2026 21:45:11 -0700 (PDT) Message-ID: <35f92bc8-1eb1-43a0-bed2-aaac87a61c19@redhat.com> Date: Mon, 23 Mar 2026 14:44:58 +1000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 02/40] arm_mpam: Reset when feature configuration bit unset To: Ben Horgan Cc: amitsinght@marvell.com, baisheng.gao@unisoc.com, baolin.wang@linux.alibaba.com, carl@os.amperecomputing.com, dave.martin@arm.com, david@kernel.org, dfustini@baylibre.com, fenghuay@nvidia.com, james.morse@arm.com, jonathan.cameron@huawei.com, kobak@nvidia.com, lcherian@marvell.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, peternewman@google.com, punit.agrawal@oss.qualcomm.com, quic_jiles@quicinc.com, reinette.chatre@intel.com, rohit.mathew@arm.com, scott@os.amperecomputing.com, sdonthineni@nvidia.com, tan.shaopeng@fujitsu.com, xhao@linux.alibaba.com, catalin.marinas@arm.com, will@kernel.org, corbet@lwn.net, maz@kernel.org, oupton@kernel.org, joey.gouly@arm.com, suzuki.poulose@arm.com, kvmarm@lists.linux.dev, zengheng4@huawei.com, linux-doc@vger.kernel.org References: <20260313144617.3420416-1-ben.horgan@arm.com> <20260313144617.3420416-3-ben.horgan@arm.com> Content-Language: en-US From: Gavin Shan In-Reply-To: <20260313144617.3420416-3-ben.horgan@arm.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/14/26 12:45 AM, Ben Horgan wrote: > To indicate that the configuration, of the controls used by resctrl, in a > RIS need resetting to driver defaults the reset flags in mpam_config are > set. However, these flags are only ever set temporarily at RIS scope in > mpam_reset_ris() and hence mpam_cpu_online() will never reset these > controls to default. As the hardware reset is unknown this leads to unknown > configuration when the control values haven't been configured away from the > defaults. > > Use the policy that an unset feature configuration bit means reset. In this > way the mpam_config in the component can encode that it should be in reset > state and mpam_reprogram_msc() will reset controls as needed. > > Fixes: 09b89d2a72f3 ("arm_mpam: Allow configuration to be applied and restored during cpu online") > Signed-off-by: Ben Horgan > --- > This goes back to the initial feature configuration policy that James > used in the MPAM base driver rfc but I unfortunately > suggested him to change it. > --- > drivers/resctrl/mpam_devices.c | 40 ++++++++++------------------------ > 1 file changed, 12 insertions(+), 28 deletions(-) > Reviewed-by: Gavin Shan