From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 16AD0F4FA; Mon, 20 Oct 2025 16:28:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760977707; cv=none; b=fvTgpb9twBBKYKEhT24sXR7X/s/En5RqbLoTZcOl6fqGN1TBh1o5D6dhKo9Y4LuS8Kr+OJ+vFFaRY9mGxNFH1NQIFPSwBZJv2WvDfo4hK7d73Tin+qEGf0Mfx0nEIFWsUMS0qWlyKTpIAbrU1z1IH3cUyZNokiXVKIQByDyQk9s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760977707; c=relaxed/simple; bh=AOuKbHm4cIrK27uOxuqdzZxdGEgZkIlRzauZRokpYUY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=RWucl+E443Vm1vYyCr3nJROMLTAjvZgzoJ02h9Ma14eJ++H5HO9epdBv8urB+B0LEXNF/x4Ge8pDyESn+26FM+eCr2Vmr/TQ9mcg2uupEY0XtcOdI2zdMAenFTa483+fhCn9cv8oXaL5sY41psHn/PxTeVmZbh5I6EQhOgBDWaA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 00A241063; Mon, 20 Oct 2025 09:28:13 -0700 (PDT) Received: from [10.1.196.46] (e134344.arm.com [10.1.196.46]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 49B283F63F; Mon, 20 Oct 2025 09:28:16 -0700 (PDT) Message-ID: <7ac2abe6-7311-4b20-b1fb-566ed7516315@arm.com> Date: Mon, 20 Oct 2025 17:28:14 +0100 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 v3 19/29] arm_mpam: Use a static key to indicate when mpam is enabled To: James Morse , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-acpi@vger.kernel.org Cc: D Scott Phillips OS , carl@os.amperecomputing.com, lcherian@marvell.com, bobo.shaobowang@huawei.com, tan.shaopeng@fujitsu.com, baolin.wang@linux.alibaba.com, Jamie Iles , Xin Hao , peternewman@google.com, dfustini@baylibre.com, amitsinght@marvell.com, David Hildenbrand , Dave Martin , Koba Ko , Shanker Donthineni , fenghuay@nvidia.com, baisheng.gao@unisoc.com, Jonathan Cameron , Rob Herring , Rohit Mathew , Rafael Wysocki , Len Brown , Lorenzo Pieralisi , Hanjun Guo , Sudeep Holla , Catalin Marinas , Will Deacon , Greg Kroah-Hartman , Danilo Krummrich , Jeremy Linton , Gavin Shan References: <20251017185645.26604-1-james.morse@arm.com> <20251017185645.26604-20-james.morse@arm.com> From: Ben Horgan Content-Language: en-US In-Reply-To: <20251017185645.26604-20-james.morse@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi James, On 10/17/25 19:56, James Morse wrote: > Once all the MSC have been probed, the system wide usable number of > PARTID is known and the configuration arrays can be allocated. > > After this point, checking all the MSC have been probed is pointless, > and the cpuhp callbacks should restore the configuration, instead of > just resetting the MSC. > > Add a static key to enable this behaviour. This will also allow MPAM > to be disabled in response to an error, and the architecture code to > enable/disable the context switch of the MPAM system registers. > > Signed-off-by: James Morse > Reviewed-by: Jonathan Cameron > Reviewed-by: Ben Horgan > Reviewed-by: Fenghua Yu > Tested-by: Fenghua Yu > --- > Changes since v2: > * Removed the word 'TODO'. > * Fixed a typo in the commit message. > --- [..] > diff --git a/drivers/resctrl/mpam_internal.h b/drivers/resctrl/mpam_internal.h > index a04b09abd814..d492df9a1735 100644 > --- a/drivers/resctrl/mpam_internal.h > +++ b/drivers/resctrl/mpam_internal.h > @@ -9,6 +9,7 @@ > #include > #include > #include > +#include > #include > #include > #include > @@ -19,8 +20,16 @@ > > #define MPAM_MSC_MAX_NUM_RIS 16 > > + nit: stray whitespace change > struct platform_device; > > +DECLARE_STATIC_KEY_FALSE(mpam_enabled); > + > +static inline bool mpam_is_enabled(void) > +{ > + return static_branch_likely(&mpam_enabled); > +} > + > /* > * Structures protected by SRCU may not be freed for a surprising amount of > * time (especially if perf is running). To ensure the MPAM error interrupt can -- Thanks, Ben