From patchwork Wed Oct 1 19:38:23 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alan Tull X-Patchwork-Id: 5014241 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 EA2D9BEEA6 for ; Wed, 1 Oct 2014 19:47:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 16FAD20211 for ; Wed, 1 Oct 2014 19:47:46 +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 0835E201FA for ; Wed, 1 Oct 2014 19:47:45 +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 1XZPpo-00089n-GF; Wed, 01 Oct 2014 19:45:12 +0000 Received: from mail-bn1bon0090.outbound.protection.outlook.com ([157.56.111.90] helo=na01-bn1-obe.outbound.protection.outlook.com) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1XZPpg-0006zx-Ce for linux-arm-kernel@lists.infradead.org; Wed, 01 Oct 2014 19:45:05 +0000 Received: from atx-linux-37.altera.com (64.129.157.38) by BY2PR03MB314.namprd03.prod.outlook.com (10.141.139.19) with Microsoft SMTP Server (TLS) id 15.0.1039.12; Wed, 1 Oct 2014 19:44:34 +0000 From: To: , Subject: [PATCH v2 1/2] socfpga: hotplug: put cpu1 in wfi Date: Wed, 1 Oct 2014 14:38:23 -0500 Message-ID: <1412192304-1209-2-git-send-email-atull@opensource.altera.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1412192304-1209-1-git-send-email-atull@opensource.altera.com> References: <1412192304-1209-1-git-send-email-atull@opensource.altera.com> MIME-Version: 1.0 X-Originating-IP: [64.129.157.38] X-ClientProxiedBy: BLUPR05CA0053.namprd05.prod.outlook.com (10.141.20.23) To BY2PR03MB314.namprd03.prod.outlook.com (10.141.139.19) X-Microsoft-Antispam: UriScan:; X-Microsoft-Antispam: BCL:0;PCL:0;RULEID:;SRVR:BY2PR03MB314; X-Forefront-PRVS: 0351D213B3 X-Forefront-Antispam-Report: SFV:NSPM; SFS:(10009020)(6009001)(189002)(199003)(77096002)(105586002)(81156004)(85306004)(106356001)(102836001)(33646002)(229853001)(107046002)(48376002)(99396003)(50466002)(77156001)(53416004)(10300001)(42186005)(95666004)(97736003)(20776003)(50226001)(47776003)(64706001)(50986999)(4396001)(86152002)(92566001)(92726001)(21056001)(62966002)(120916001)(93916002)(76176999)(86362001)(31966008)(88136002)(19580405001)(87286001)(85852003)(89996001)(19580395003)(76482002)(66066001)(69596002)(101416001)(87976001)(80022003)(104166001)(46102003); DIR:OUT; SFP:1101; SCL:1; SRVR:BY2PR03MB314; H:atx-linux-37.altera.com; FPR:; MLV:sfv; PTR:InfoNoRecords; MX:1; A:0; LANG:en; X-OriginatorOrg: opensource.altera.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20141001_124504_570045_85D98429 X-CRM114-Status: GOOD ( 12.71 ) X-Spam-Score: -0.2 (/) Cc: Alan Tull , yvanderv@opensource.altera.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, delicious.quinoa@gmail.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.18-1 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, RCVD_IN_DNSWL_NONE, 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 From: Alan Tull Use WFI when putting CPU1 to sleep. Don't hold CPU1 in reset since that results in increased power consumption. Reset CPU1 briefly during CPU1 bootup. This has been tested for hotplug and suspend/resume and results in no increased power consumption. Signed-off-by: Alan Tull v2: no need to flush the caches clean up spacing in comments replace a register offset with a macro --- arch/arm/mach-socfpga/core.h | 3 +++ arch/arm/mach-socfpga/platsmp.c | 16 ++++++++++------ 2 files changed, 13 insertions(+), 6 deletions(-) diff --git a/arch/arm/mach-socfpga/core.h b/arch/arm/mach-socfpga/core.h index 572b8f7..953a9c0 100644 --- a/arch/arm/mach-socfpga/core.h +++ b/arch/arm/mach-socfpga/core.h @@ -21,6 +21,7 @@ #define __MACH_CORE_H #define SOCFPGA_RSTMGR_CTRL 0x04 +#define SOCFPGA_RSTMGR_MODMPURST 0x10 #define SOCFPGA_RSTMGR_MODPERRST 0x14 #define SOCFPGA_RSTMGR_BRGMODRST 0x1c @@ -28,6 +29,8 @@ #define RSTMGR_CTRL_SWCOLDRSTREQ 0x1 /* Cold Reset */ #define RSTMGR_CTRL_SWWARMRSTREQ 0x2 /* Warm Reset */ +#define RSTMGR_MPUMODRST_CPU1 0x2 /* CPU1 Reset */ + extern void socfpga_secondary_startup(void); extern void __iomem *socfpga_scu_base_addr; diff --git a/arch/arm/mach-socfpga/platsmp.c b/arch/arm/mach-socfpga/platsmp.c index 5356a72..97907dd 100644 --- a/arch/arm/mach-socfpga/platsmp.c +++ b/arch/arm/mach-socfpga/platsmp.c @@ -34,6 +34,10 @@ static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle) int trampoline_size = &secondary_trampoline_end - &secondary_trampoline; if (cpu1start_addr) { + /* This will put CPU #1 into reset. */ + __raw_writel(RSTMGR_MPUMODRST_CPU1, + rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST); + memcpy(phys_to_virt(0), &secondary_trampoline, trampoline_size); __raw_writel(virt_to_phys(socfpga_secondary_startup), @@ -43,8 +47,9 @@ static int socfpga_boot_secondary(unsigned int cpu, struct task_struct *idle) smp_wmb(); outer_clean_range(0, trampoline_size); - /* This will release CPU #1 out of reset.*/ - __raw_writel(0, rst_manager_base_addr + 0x10); + /* This will release CPU #1 out of reset. */ + __raw_writel(0, + rst_manager_base_addr + SOCFPGA_RSTMGR_MODMPURST); } return 0; @@ -86,10 +91,9 @@ static void __init socfpga_smp_prepare_cpus(unsigned int max_cpus) */ static void socfpga_cpu_die(unsigned int cpu) { - cpu_do_idle(); - - /* We should have never returned from idle */ - panic("cpu %d unexpectedly exit from shutdown\n", cpu); + /* Do WFI. If we wake up early, go back into WFI */ + while (1) + cpu_do_idle(); } struct smp_operations socfpga_smp_ops __initdata = {