From patchwork Mon Jun 27 16:50:33 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sudeep Holla X-Patchwork-Id: 12896882 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 C0A99C43334 for ; Mon, 27 Jun 2022 16:53:06 +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=FHmtrEmPuqJJeFZwsW7qG9xlu7DVIrrmvnv47CqdBGY=; b=dXfKAryuhYxA52 BH5A5773/4Dc7hVcgA4qjwlsOzdoi44vw4vfzLZhy6cyWCB98//EngT7JU2pX0pEE3Og60MG3ESqg mgGhmr93GUPi7dIzbmMbiOU9NQZvKvxk6jNo3JFr/m2G14mtv4sKTQ6iBMJBDhER8VTefodrIkLqH mlbVwqwmXJIdv/ovhZ6aSBPTFCC3/YZWK+dLAASvjQYaxOeu4DsoL494HNvZ1HTVBUBytN/zISdIQ yIH9VyC4lUL+o5FpxsRk6tlWiDT/D6ieAatMi2mrx3erXvT9N9Ar1SOG67dOC4F6FCmK+4r4AQU2n 3TF+IA1w9VwOUSA+4QFg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o5ryr-001v8z-Na; Mon, 27 Jun 2022 16:52:57 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1o5rx6-001u40-RI; Mon, 27 Jun 2022 16:51:11 +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 E18AD175A; Mon, 27 Jun 2022 09:51:07 -0700 (PDT) Received: from usa.arm.com (e103737-lin.cambridge.arm.com [10.1.197.49]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id E53FD3F792; Mon, 27 Jun 2022 09:51:05 -0700 (PDT) From: Sudeep Holla To: linux-kernel@vger.kernel.org Cc: Sudeep Holla , Greg Kroah-Hartman , Atish Patra , Atish Patra , Vincent Guittot , Dietmar Eggemann , Qing Wang , Rob Herring , "Rafael J . Wysocki" , Ionela Voinescu , Pierre Gondois , linux-arm-kernel@lists.infradead.org, linux-riscv@lists.infradead.org, Gavin Shan Subject: [PATCH v5 05/19] cacheinfo: Add support to check if last level cache(LLC) is valid or shared Date: Mon, 27 Jun 2022 17:50:33 +0100 Message-Id: <20220627165047.336669-6-sudeep.holla@arm.com> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220627165047.336669-1-sudeep.holla@arm.com> References: <20220627165047.336669-1-sudeep.holla@arm.com> MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220627_095109_007904_EB7115C6 X-CRM114-Status: GOOD ( 12.89 ) 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 It is useful to have helper to check if the given two CPUs share last level cache. We can do that check by comparing fw_token or by comparing the cache ID. Currently we check just for fw_token as the cache ID is optional. This helper can be used to build the llc_sibling during arch specific topology parsing and feeding information to the sched_domains. This also helps to get rid of llc_id in the CPU topology as it is sort of duplicate information. Also add helper to check if the llc information in cacheinfo is valid or not. Link: https://lore.kernel.org/r/20220621192034.3332546-6-sudeep.holla@arm.com Tested-by: Ionela Voinescu Reviewed-by: Gavin Shan Signed-off-by: Sudeep Holla --- drivers/base/cacheinfo.c | 26 ++++++++++++++++++++++++++ include/linux/cacheinfo.h | 2 ++ 2 files changed, 28 insertions(+) diff --git a/drivers/base/cacheinfo.c b/drivers/base/cacheinfo.c index 2cea9201f31c..fdc1baa342f1 100644 --- a/drivers/base/cacheinfo.c +++ b/drivers/base/cacheinfo.c @@ -47,6 +47,32 @@ static inline bool cache_leaves_are_shared(struct cacheinfo *this_leaf, return sib_leaf->fw_token == this_leaf->fw_token; } +bool last_level_cache_is_valid(unsigned int cpu) +{ + struct cacheinfo *llc; + + if (!cache_leaves(cpu)) + return false; + + llc = per_cpu_cacheinfo_idx(cpu, cache_leaves(cpu) - 1); + + return !!llc->fw_token; +} + +bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y) +{ + struct cacheinfo *llc_x, *llc_y; + + if (!last_level_cache_is_valid(cpu_x) || + !last_level_cache_is_valid(cpu_y)) + return false; + + llc_x = per_cpu_cacheinfo_idx(cpu_x, cache_leaves(cpu_x) - 1); + llc_y = per_cpu_cacheinfo_idx(cpu_y, cache_leaves(cpu_y) - 1); + + return cache_leaves_are_shared(llc_x, llc_y); +} + #ifdef CONFIG_OF /* OF properties to query for a given cache type */ struct cache_type_info { diff --git a/include/linux/cacheinfo.h b/include/linux/cacheinfo.h index 4ff37cb763ae..7e429bc5c1a4 100644 --- a/include/linux/cacheinfo.h +++ b/include/linux/cacheinfo.h @@ -82,6 +82,8 @@ struct cpu_cacheinfo *get_cpu_cacheinfo(unsigned int cpu); int init_cache_level(unsigned int cpu); int populate_cache_leaves(unsigned int cpu); int cache_setup_acpi(unsigned int cpu); +bool last_level_cache_is_valid(unsigned int cpu); +bool last_level_cache_is_shared(unsigned int cpu_x, unsigned int cpu_y); #ifndef CONFIG_ACPI_PPTT /* * acpi_find_last_cache_level is only called on ACPI enabled