From mboxrd@z Thu Jan 1 00:00:00 1970 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 00EBFC83F1B for ; Fri, 11 Jul 2025 18:35:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=/eUFkCjBuj9qn0bgnM4aSUuOFHUMlpETuZGRyjXcKkY=; b=TLevBLoeW0f8kaCRinX1H4NpBu aLHE64wNmzN/uDlHek2l/xbwpsLEL5lJqP1hGlvE5neql/b9buYf7dFOZLn+Ot5sA7zmJ3NeEDWKB sGcc5pJ4XFqYFTawzKqxnDjkuhEnV4EkgP76jRsGKnd0MwggbAOQ2CbTNiZknzTp7dGrlbaHxbTF9 oH8Vvwwdkvco/eugHNzBlo/qXvWcEaodhp0YimTh58QCfOKc2TMaXBW5FVsfFGTTiRMG9Kxp13hjY osUqvpYsztOvF/mW6v/O69ioE5815zWtOCcsWY4POLtsz76eJoPl1jBU4LiIQbqHk4bZ03We+8MGv 6h800IFQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uaIal-0000000FWiV-0P8n; Fri, 11 Jul 2025 18:35:27 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1uaITb-0000000FVSw-2Ac0 for linux-arm-kernel@lists.infradead.org; Fri, 11 Jul 2025 18:28:05 +0000 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 9FD592682; Fri, 11 Jul 2025 11:27:52 -0700 (PDT) Received: from merodach.members.linode.com (usa-sjc-mx-foss1.foss.arm.com [172.31.20.19]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id A77063F694; Fri, 11 Jul 2025 11:28:01 -0700 (PDT) From: James Morse To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Cc: Greg Kroah-Hartman , "Rafael J . Wysocki" , sudeep.holla@arm.com, Rob Herring , Ben Horgan , Jonathan Cameron , Catalin Marinas , Will Deacon , James Morse , Gavin Shan Subject: [PATCH v3 2/3] cacheinfo: Add arch hook to compress CPU h/w id into 32 bits for cache-id Date: Fri, 11 Jul 2025 18:27:42 +0000 Message-Id: <20250711182743.30141-3-james.morse@arm.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20250711182743.30141-1-james.morse@arm.com> References: <20250711182743.30141-1-james.morse@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250711_112803_596426_7094DA96 X-CRM114-Status: GOOD ( 13.60 ) X-BeenThere: linux-arm-kernel@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-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Filesystems like resctrl use the cache-id exposed via sysfs to identify groups of CPUs. The value is also used for PCIe cache steering tags. On DT platforms cache-id is not something that is described in the device-tree, but instead generated from the smallest CPU h/w id of the CPUs associated with that cache. CPU h/w ids may be larger than 32 bits. Add a hook to allow architectures to compress the value from the devicetree into 32 bits. Returning the same value is always safe as cache_of_set_id() will stop if a value larger than 32 bits is seen. For example, on arm64 the value is the MPIDR affinity register, which only has 32 bits of affinity data, but spread accross the 64 bit field. An arch-specific bit swizzle gives a 32 bit value. Signed-off-by: James Morse Reviewed-by: Jonathan Cameron Reviewed-by: Gavin Shan --- drivers/base/cacheinfo.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 4e2f60c85e74..613410705a47 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -203,6 +203,10 @@ static bool match_cache_node(struct device_node *cpu, return false; } +#ifndef arch_compact_of_hwid +#define arch_compact_of_hwid(_x) (_x) +#endif + static void cache_of_set_id(struct cacheinfo *this_leaf, struct device_node *cache_node) { @@ -212,6 +216,7 @@ static void cache_of_set_id(struct cacheinfo *this_leaf, for_each_of_cpu_node(cpu) { u64 id = of_get_cpu_hwid(cpu, 0); + id = arch_compact_of_hwid(id); if (FIELD_GET(GENMASK_ULL(63, 32), id)) { of_node_put(cpu); return; -- 2.39.5