From patchwork Thu May 23 13:30:49 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thomas Petazzoni X-Patchwork-Id: 2607001 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) by patchwork2.kernel.org (Postfix) with ESMTP id D938BDFB78 for ; Thu, 23 May 2013 13:33:47 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UfVcw-000677-Ul; Thu, 23 May 2013 13:32:20 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UfVcW-00055B-Tn; Thu, 23 May 2013 13:31:52 +0000 Received: from mail.free-electrons.com ([94.23.35.102]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UfVc0-00050f-Ed for linux-arm-kernel@lists.infradead.org; Thu, 23 May 2013 13:31:22 +0000 Received: by mail.free-electrons.com (Postfix, from userid 106) id 9072D768; Thu, 23 May 2013 15:30:59 +0200 (CEST) X-Spam-Checker-Version: SpamAssassin 3.3.2 (2011-06-06) on mail.free-electrons.com X-Spam-Level: X-Spam-Status: No, score=-1.0 required=5.0 tests=ALL_TRUSTED,SHORTCIRCUIT, URIBL_BLOCKED shortcircuit=ham autolearn=disabled version=3.3.2 Received: from localhost (col31-4-88-188-83-94.fbx.proxad.net [88.188.83.94]) by mail.free-electrons.com (Postfix) with ESMTPSA id C52AA742; Thu, 23 May 2013 15:30:58 +0200 (CEST) From: Thomas Petazzoni To: Andrew Lunn , Jason Cooper , Gregory Clement Subject: [PATCH v2 1/6] arm: mvebu: remove dependency of SMP init on static I/O mapping Date: Thu, 23 May 2013 15:30:49 +0200 Message-Id: <1369315854-32724-2-git-send-email-thomas.petazzoni@free-electrons.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1369315854-32724-1-git-send-email-thomas.petazzoni@free-electrons.com> References: <1369315854-32724-1-git-send-email-thomas.petazzoni@free-electrons.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130523_093120_798508_8C3E491E X-CRM114-Status: GOOD ( 19.04 ) X-Spam-Score: -3.0 (---) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-3.0 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -1.1 RP_MATCHES_RCVD Envelope sender domain matches handover relay domain -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Lior Amsalem , Arnd Bergmann , Maen Suleiman , Ezequiel Garcia , linux-arm-kernel@lists.infradead.org, Sebastian Hesselbarth 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: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org The ->smp_init_cpus() function is called very early during boot, at a point where dynamic I/O mappings are not yet possible. However, in the Armada 370/XP implementation of this function, we have to get the number of CPUs. We used to do that by accessing a hardware register, which requires relying on a static I/O mapping set up by ->map_io(). Not only this requires hardcoding a virtual address, but it also prevents us from removing the static I/O mapping. So this commit changes the way used to get the number of CPUs: we now use the Device Tree, which is a representation of the hardware, and provides us the number of available CPUs. This is also more accurate, because it potentially allows to boot the Linux kernel on only a number of CPUs given by the Device Tree, instead of unconditionally on all CPUs. As a consequence, the coherency_get_cpu_count() function becomes no longer used, so we remove it. Signed-off-by: Thomas Petazzoni --- arch/arm/mach-mvebu/coherency.c | 12 ------------ arch/arm/mach-mvebu/coherency.h | 4 ---- arch/arm/mach-mvebu/common.h | 2 ++ arch/arm/mach-mvebu/platsmp.c | 10 +++++++++- 4 files changed, 11 insertions(+), 17 deletions(-) diff --git a/arch/arm/mach-mvebu/coherency.c b/arch/arm/mach-mvebu/coherency.c index 8278960..46d66c0 100644 --- a/arch/arm/mach-mvebu/coherency.c +++ b/arch/arm/mach-mvebu/coherency.c @@ -47,18 +47,6 @@ static struct of_device_id of_coherency_table[] = { { /* end of list */ }, }; -#ifdef CONFIG_SMP -int coherency_get_cpu_count(void) -{ - int reg, cnt; - - reg = readl(coherency_base + COHERENCY_FABRIC_CFG_OFFSET); - cnt = (reg & 0xF) + 1; - - return cnt; -} -#endif - /* Function defined in coherency_ll.S */ int ll_set_cpu_coherent(void __iomem *base_addr, unsigned int hw_cpu_id); diff --git a/arch/arm/mach-mvebu/coherency.h b/arch/arm/mach-mvebu/coherency.h index 2f42813..df33ad8 100644 --- a/arch/arm/mach-mvebu/coherency.h +++ b/arch/arm/mach-mvebu/coherency.h @@ -14,10 +14,6 @@ #ifndef __MACH_370_XP_COHERENCY_H #define __MACH_370_XP_COHERENCY_H -#ifdef CONFIG_SMP -int coherency_get_cpu_count(void); -#endif - int set_cpu_coherent(int cpu_id, int smp_group_id); int coherency_init(void); diff --git a/arch/arm/mach-mvebu/common.h b/arch/arm/mach-mvebu/common.h index aa27bc2..98defd5 100644 --- a/arch/arm/mach-mvebu/common.h +++ b/arch/arm/mach-mvebu/common.h @@ -15,6 +15,8 @@ #ifndef __ARCH_MVEBU_COMMON_H #define __ARCH_MVEBU_COMMON_H +#define ARMADA_XP_MAX_CPUS 4 + void mvebu_restart(char mode, const char *cmd); void armada_370_xp_init_irq(void); diff --git a/arch/arm/mach-mvebu/platsmp.c b/arch/arm/mach-mvebu/platsmp.c index 875ea74..93f2f3a 100644 --- a/arch/arm/mach-mvebu/platsmp.c +++ b/arch/arm/mach-mvebu/platsmp.c @@ -88,8 +88,16 @@ static int __cpuinit armada_xp_boot_secondary(unsigned int cpu, static void __init armada_xp_smp_init_cpus(void) { + struct device_node *np; unsigned int i, ncores; - ncores = coherency_get_cpu_count(); + + np = of_find_node_by_name(NULL, "cpus"); + if (!np) + panic("No 'cpus' node found\n"); + + ncores = of_get_child_count(np); + if (ncores == 0 || ncores > ARMADA_XP_MAX_CPUS) + panic("Invalid number of CPUs in DT\n"); /* Limit possible CPUs to defconfig */ if (ncores > nr_cpu_ids) {