From patchwork Tue Apr 29 23:36:13 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Zi Shen Lim X-Patchwork-Id: 4089671 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 8A3B4BFF02 for ; Tue, 29 Apr 2014 23:41:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 9796E20200 for ; Tue, 29 Apr 2014 23:41:05 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id AFDF7201B4 for ; Tue, 29 Apr 2014 23:41:04 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WfHZt-00045m-NL; Tue, 29 Apr 2014 23:36:45 +0000 Received: from mail-gw1-out.broadcom.com ([216.31.210.62]) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WfHZr-00043W-Hp for linux-arm-kernel@lists.infradead.org; Tue, 29 Apr 2014 23:36:44 +0000 X-IronPort-AV: E=Sophos;i="4.97,954,1389772800"; d="scan'208";a="27289553" Received: from irvexchcas06.broadcom.com (HELO IRVEXCHCAS06.corp.ad.broadcom.com) ([10.9.208.53]) by mail-gw1-out.broadcom.com with ESMTP; 29 Apr 2014 17:47:00 -0700 Received: from IRVEXCHSMTP2.corp.ad.broadcom.com (10.9.207.52) by IRVEXCHCAS06.corp.ad.broadcom.com (10.9.208.53) with Microsoft SMTP Server (TLS) id 14.3.174.1; Tue, 29 Apr 2014 16:36:20 -0700 Received: from mail-sj1-12.sj.broadcom.com (10.10.10.20) by IRVEXCHSMTP2.corp.ad.broadcom.com (10.9.207.52) with Microsoft SMTP Server id 14.3.174.1; Tue, 29 Apr 2014 16:36:21 -0700 Received: from lc-sj1-5012.broadcom.com (lc-sj1-5012.sj.broadcom.com [10.66.65.230]) by mail-sj1-12.sj.broadcom.com (Postfix) with ESMTP id 5C48127A81; Tue, 29 Apr 2014 16:36:21 -0700 (PDT) Received: by lc-sj1-5012.broadcom.com (Postfix, from userid 28931) id 50F71E01E79; Tue, 29 Apr 2014 16:36:21 -0700 (PDT) From: Zi Shen Lim To: Lorenzo Pieralisi , Mark Brown , Catalin Marinas , Mark Rutland , Will Deacon Subject: [PATCHv3] arm64: topology: add MPIDR-based detection Date: Tue, 29 Apr 2014 16:36:13 -0700 Message-ID: <1398814573-27389-1-git-send-email-zlim@broadcom.com> X-Mailer: git-send-email 1.8.4.3 MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140429_163643_678130_CE533594 X-CRM114-Status: GOOD ( 13.47 ) X-Spam-Score: -3.0 (---) Cc: Zi Shen Lim , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-2.5 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Create cpu topology based on MPIDR. When hardware sets MPIDR to sane values, this method will always work. Therefore it should also work well as the fallback method. [1] When we have multiple processing elements in the system, we create the cpu topology by mapping each affinity level (from lowest to highest) to threads (if they exist), cores, and clusters. We combine data from all higher affinity levels into cluster_id so we don't lose any information from MPIDR. [2] [1] http://www.spinics.net/lists/arm-kernel/msg317445.html [2] https://lkml.org/lkml/2014/4/23/703 Signed-off-by: Zi Shen Lim --- v1->v2: Addressed comments from Mark Brown. - Reduce noise. Use pr_debug instead of pr_info. - Don't ignore higher affinity levels. v2->v3: Addressed comments from Lorenzo Pieralisi. - Rebased on top of Mark Brown's DT topology series. - Make MPIDR fallback option. - Fixed usage of mpidr_hash.shift_aff. Please review :) Tested on my multi-core multi-thread model. arch/arm64/include/asm/cputype.h | 5 +++++ arch/arm64/kernel/topology.c | 44 +++++++++++++++++++++++++++++++++++++--- 2 files changed, 46 insertions(+), 3 deletions(-) diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h index c404fb0..b3b3287 100644 --- a/arch/arm64/include/asm/cputype.h +++ b/arch/arm64/include/asm/cputype.h @@ -18,6 +18,8 @@ #define INVALID_HWID ULONG_MAX +#define MPIDR_UP_BITMASK (0x1 << 30) +#define MPIDR_MT_BITMASK (0x1 << 24) #define MPIDR_HWID_BITMASK 0xff00ffffff #define MPIDR_LEVEL_BITS_SHIFT 3 @@ -30,6 +32,9 @@ #define MPIDR_AFFINITY_LEVEL(mpidr, level) \ ((mpidr >> MPIDR_LEVEL_SHIFT(level)) & MPIDR_LEVEL_MASK) +#define MPIDR_AFF_MASK(level) \ + ((u64)MPIDR_LEVEL_MASK << MPIDR_LEVEL_SHIFT(level)) + #define read_cpuid(reg) ({ \ u64 __val; \ asm("mrs %0, " #reg : "=r" (__val)); \ diff --git a/arch/arm64/kernel/topology.c b/arch/arm64/kernel/topology.c index caf2a7c..cfaa2a3 100644 --- a/arch/arm64/kernel/topology.c +++ b/arch/arm64/kernel/topology.c @@ -21,6 +21,8 @@ #include #include +#include +#include #include /* @@ -362,9 +364,7 @@ static void update_siblings_masks(unsigned int cpuid) int cpu; if (cpuid_topo->cluster_id == -1) { - /* - * DT does not contain topology information for this cpu. - */ + /* No topology information for this cpu ?! */ pr_debug("CPU%u: No topology information configured\n", cpuid); return; } @@ -391,6 +391,44 @@ static void update_siblings_masks(unsigned int cpuid) void store_cpu_topology(unsigned int cpuid) { + struct cpu_topology *cpuid_topo = &cpu_topology[cpuid]; + u64 mpidr; + + if (cpuid_topo->cluster_id != -1) + goto topology_populated; + + mpidr = read_cpuid_mpidr(); + + /* Create cpu topology mapping based on MPIDR. */ + if (mpidr & MPIDR_UP_BITMASK) { + /* Uniprocessor system */ + cpuid_topo->thread_id = -1; + cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cpuid_topo->cluster_id = 0; + } else if (mpidr & MPIDR_MT_BITMASK) { + /* Multiprocessor system : Multi-threads per core */ + cpuid_topo->thread_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 1); + cpuid_topo->cluster_id = + ((mpidr & MPIDR_AFF_MASK(2)) >> mpidr_hash.shift_aff[2] | + (mpidr & MPIDR_AFF_MASK(3)) >> mpidr_hash.shift_aff[3]) + >> mpidr_hash.shift_aff[1] >> mpidr_hash.shift_aff[0]; + } else { + /* Multiprocessor system : Single-thread per core */ + cpuid_topo->thread_id = -1; + cpuid_topo->core_id = MPIDR_AFFINITY_LEVEL(mpidr, 0); + cpuid_topo->cluster_id = + ((mpidr & MPIDR_AFF_MASK(1)) >> mpidr_hash.shift_aff[1] | + (mpidr & MPIDR_AFF_MASK(2)) >> mpidr_hash.shift_aff[2] | + (mpidr & MPIDR_AFF_MASK(3)) >> mpidr_hash.shift_aff[3]) + >> mpidr_hash.shift_aff[0]; + } + + pr_debug("CPU%u: cluster %d core %d thread %d mpidr %llx\n", + cpuid, cpuid_topo->cluster_id, cpuid_topo->core_id, + cpuid_topo->thread_id, mpidr); + +topology_populated: update_siblings_masks(cpuid); update_cpu_power(cpuid); }