From patchwork Tue Dec 24 00:39:48 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Stephen Boyd X-Patchwork-Id: 3399301 Return-Path: X-Original-To: patchwork-linux-arm-msm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 567869F314 for ; Tue, 24 Dec 2013 00:43:14 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 63D3B2076A for ; Tue, 24 Dec 2013 00:43:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 74D6920595 for ; Tue, 24 Dec 2013 00:43:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932851Ab3LXAmw (ORCPT ); Mon, 23 Dec 2013 19:42:52 -0500 Received: from smtp.codeaurora.org ([198.145.11.231]:47599 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932849Ab3LXAkA (ORCPT ); Mon, 23 Dec 2013 19:40:00 -0500 Received: from smtp.codeaurora.org (localhost [127.0.0.1]) by smtp.codeaurora.org (Postfix) with ESMTP id B6B7C13EF9E; Tue, 24 Dec 2013 00:39:59 +0000 (UTC) Received: by smtp.codeaurora.org (Postfix, from userid 486) id A19B113EFB9; Tue, 24 Dec 2013 00:39:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-7.4 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from sboyd-linux.qualcomm.com (i-global252.qualcomm.com [199.106.103.252]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: sboyd@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id 8980213EF9E; Tue, 24 Dec 2013 00:39:58 +0000 (UTC) From: Stephen Boyd To: linux-arm-kernel@lists.infradead.org Cc: David Brown , Rohit Vaswani , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Kumar Gala , devicetree@vger.kernel.org, Mark Rutland , Arnd Bergmann , Russell King Subject: [PATCH v2 4/9] ARM: Introduce CPU_METHOD_OF_DECLARE() for cpu hotplug/smp Date: Mon, 23 Dec 2013 16:39:48 -0800 Message-Id: <1387845593-10050-5-git-send-email-sboyd@codeaurora.org> X-Mailer: git-send-email 1.8.5.1.163.gd7aced9 In-Reply-To: <1387845593-10050-1-git-send-email-sboyd@codeaurora.org> References: <1387845593-10050-1-git-send-email-sboyd@codeaurora.org> X-Virus-Scanned: ClamAV using ClamSMTP Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The goal of multi-platform kernels is to remove the need for mach directories and machine descriptors. To further that goal, introduce CPU_METHOD_OF_DECLARE() to allow cpu hotplug/smp support to be separated from the machine descriptors. Implementers should specify an enable-method property in their cpus node and then implement a matching set of smp_ops in their hotplug/smp code, wiring it up with the CPU_METHOD_OF_DECLARE() macro. When the kernel is compiled we'll collect all the enable-method smp_ops into one section for use at boot. At boot time we'll look for an enable-method in each cpu node and try to match that against all known CPU enable methods in the kernel. If there are no enable-methods in the cpu nodes we fallback to the cpus node and try to use any enable-method found there. If that doesn't work we fall back to the old way of using the machine descriptor. Cc: Mark Rutland Cc: Russell King Cc: Signed-off-by: Stephen Boyd --- arch/arm/include/asm/smp.h | 9 +++++++++ arch/arm/kernel/devtree.c | 40 +++++++++++++++++++++++++++++++++++++++ include/asm-generic/vmlinux.lds.h | 10 ++++++++++ 3 files changed, 59 insertions(+) diff --git a/arch/arm/include/asm/smp.h b/arch/arm/include/asm/smp.h index 22a3b9b..772435b 100644 --- a/arch/arm/include/asm/smp.h +++ b/arch/arm/include/asm/smp.h @@ -114,6 +114,15 @@ struct smp_operations { #endif }; +struct of_cpu_method { + const char *method; + struct smp_operations *ops; +}; + +#define CPU_METHOD_OF_DECLARE(name, _method, _ops) \ + static const struct of_cpu_method __cpu_method_of_table_##name \ + __used __section(__cpu_method_of_table) \ + = { .method = _method, .ops = _ops } /* * set platform specific SMP operations */ diff --git a/arch/arm/kernel/devtree.c b/arch/arm/kernel/devtree.c index 739c3df..91cc3f8 100644 --- a/arch/arm/kernel/devtree.c +++ b/arch/arm/kernel/devtree.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -63,6 +64,34 @@ void __init arm_dt_memblock_reserve(void) } } +#ifdef CONFIG_SMP +extern struct of_cpu_method __cpu_method_of_table_begin[]; +extern struct of_cpu_method __cpu_method_of_table_end[]; + +static int __init set_smp_ops_by_method(struct device_node *node) +{ + const char *method; + struct of_cpu_method *m = __cpu_method_of_table_begin; + + if (of_property_read_string(node, "enable-method", &method)) + return 0; + + for (; m < __cpu_method_of_table_end; m++) + if (!strcmp(m->method, method)) { + smp_set_ops(m->ops); + return 1; + } + + return 0; +} +#else +static inline int set_smp_ops_by_method(struct device_node *node) +{ + return 1; +} +#endif + + /* * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree * and builds the cpu logical map array containing MPIDR values related to @@ -79,6 +108,7 @@ void __init arm_dt_init_cpu_maps(void) * read as 0. */ struct device_node *cpu, *cpus; + int found_method = 0; u32 i, j, cpuidx = 1; u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0; @@ -150,8 +180,18 @@ void __init arm_dt_init_cpu_maps(void) } tmp_map[i] = hwid; + + if (!found_method) + found_method = set_smp_ops_by_method(cpu); } + /* + * Fallback to an enable-method in the cpus node if nothing found in + * a cpu node. + */ + if (!found_method) + set_smp_ops_by_method(cpus); + if (!bootcpu_valid) { pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n"); return; diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index bc2121f..bd02ca7 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -167,6 +167,15 @@ #define CLK_OF_TABLES() #endif +#ifdef CONFIG_SMP +#define CPU_METHOD_OF_TABLES() . = ALIGN(8); \ + VMLINUX_SYMBOL(__cpu_method_of_table_begin) = .; \ + *(__cpu_method_of_table) \ + VMLINUX_SYMBOL(__cpu_method_of_table_end) = .; +#else +#define CPU_METHOD_OF_TABLES() +#endif + #define KERNEL_DTB() \ STRUCT_ALIGN(); \ VMLINUX_SYMBOL(__dtb_start) = .; \ @@ -491,6 +500,7 @@ MEM_DISCARD(init.rodata) \ CLK_OF_TABLES() \ CLKSRC_OF_TABLES() \ + CPU_METHOD_OF_TABLES() \ KERNEL_DTB() \ IRQCHIP_OF_MATCH_TABLE()