From patchwork Mon Mar 25 13:53:15 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Simek X-Patchwork-Id: 2331511 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id F3C86DF24C for ; Mon, 25 Mar 2013 14:02:00 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1UK7ud-0005L5-TP; Mon, 25 Mar 2013 13:58:11 +0000 Received: from mail-we0-x235.google.com ([2a00:1450:400c:c03::235]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1UK7qQ-0003Cx-NE for linux-arm-kernel@lists.infradead.org; Mon, 25 Mar 2013 13:53:53 +0000 Received: by mail-we0-f181.google.com with SMTP id p43so5094157wea.12 for ; Mon, 25 Mar 2013 06:53:47 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:sender:from:to:subject:date:message-id:x-mailer :in-reply-to:references:x-gm-message-state; bh=g9TexgXnKhYDGv9pF+maXFP+C4wL3LLToBk0UytxbZ8=; b=T/yFei82gzjVJDOUr6cUH1YQUEDcBN0AtuW3ByEXmtWd9fyy941XeuRowJqCrc3IzE Xkifz6n9vl8P7L053x3bYGa0HgwEF+M/c0V4ryY42RVhMkpQKVqLKxUN+I8yyI7D1Bwv SGKPvJ431UVzcnKjrj5U1PiF+iX0iYVQiBqs/VNJXUzw58qOw8JoiLSbtIKCEGfF7u/u dx7aT/tUi8jwtwj7x/YLC1lyHQDeScg2rjTjd9N0xkuDzyS90qmRybEflm6emfZKPa5Q lEjzRk9VU5zhKto3kquBhyP5V2o4OOS5Hd1Mbs8ZbPWU00ZT3YCaQfWneURGh2tU4XKX h5Sg== X-Received: by 10.180.109.82 with SMTP id hq18mr17791508wib.0.1364219627270; Mon, 25 Mar 2013 06:53:47 -0700 (PDT) Received: from localhost (nat-63.starnet.cz. [178.255.168.63]) by mx.google.com with ESMTPS id ex1sm22565126wib.7.2013.03.25.06.53.46 (version=TLSv1.1 cipher=RC4-SHA bits=128/128); Mon, 25 Mar 2013 06:53:46 -0700 (PDT) From: Michal Simek To: linux-arm-kernel@lists.infradead.org, monstr@monstr.eu, Josh Cartwright , Steffen Trumtrar Subject: [PATCH 09/10] arm: zynq: Add hotplug support Date: Mon, 25 Mar 2013 14:53:15 +0100 Message-Id: <1364219596-4954-9-git-send-email-michal.simek@xilinx.com> X-Mailer: git-send-email 1.7.9.7 In-Reply-To: <1364219596-4954-1-git-send-email-michal.simek@xilinx.com> References: <1364219596-4954-1-git-send-email-michal.simek@xilinx.com> X-Gm-Message-State: ALoCoQnND0wdt6UGi2/gQF3NXhAYeXICR7GerHAs0yE64Zgo3x2q9N397r4jpkG2SyJz3j4fXdDq X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130325_095350_919815_C0BF8A18 X-CRM114-Status: GOOD ( 16.67 ) X-Spam-Score: -1.9 (-) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-1.9 points) pts rule name description ---- ---------------------- -------------------------------------------------- -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] 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 Signed-off-by: Michal Simek --- arch/arm/mach-zynq/Makefile | 1 + arch/arm/mach-zynq/common.h | 3 ++ arch/arm/mach-zynq/hotplug.c | 102 ++++++++++++++++++++++++++++++++++++++++++ arch/arm/mach-zynq/platsmp.c | 3 ++ 4 files changed, 109 insertions(+) create mode 100644 arch/arm/mach-zynq/hotplug.c diff --git a/arch/arm/mach-zynq/Makefile b/arch/arm/mach-zynq/Makefile index 8493a89..8e75490 100644 --- a/arch/arm/mach-zynq/Makefile +++ b/arch/arm/mach-zynq/Makefile @@ -4,4 +4,5 @@ # Common support obj-y := common.o slcr.o +obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o obj-$(CONFIG_SMP) += platsmp.o diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h index 84145fb..b4614fa 100644 --- a/arch/arm/mach-zynq/common.h +++ b/arch/arm/mach-zynq/common.h @@ -30,4 +30,7 @@ extern struct smp_operations zynq_smp_ops __initdata; extern void __iomem *zynq_slcr_base; extern void __iomem *scu_base; +/* Hotplug */ +extern void platform_cpu_die(unsigned int cpu); + #endif diff --git a/arch/arm/mach-zynq/hotplug.c b/arch/arm/mach-zynq/hotplug.c new file mode 100644 index 0000000..012bddf --- /dev/null +++ b/arch/arm/mach-zynq/hotplug.c @@ -0,0 +1,102 @@ +/* + * linux/arch/arm/mach-realview/hotplug.c + * + * Copyright (C) 2002 ARM Ltd. + * All Rights Reserved + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ +#include +#include +#include + +#include +#include +#include "common.h" + +static inline void cpu_enter_lowpower(void) +{ + unsigned int v; + + flush_cache_all(); + asm volatile( + " mcr p15, 0, %1, c7, c5, 0\n" + " dsb\n" + /* + * Turn off coherency + */ + " mrc p15, 0, %0, c1, c0, 1\n" + " bic %0, %0, #0x40\n" + " mcr p15, 0, %0, c1, c0, 1\n" + " mrc p15, 0, %0, c1, c0, 0\n" + " bic %0, %0, %2\n" + " mcr p15, 0, %0, c1, c0, 0\n" + : "=&r" (v) + : "r" (0), "Ir" (CR_C) + : "cc"); +} + +static inline void cpu_leave_lowpower(void) +{ + unsigned int v; + + asm volatile( + " mrc p15, 0, %0, c1, c0, 0\n" + " orr %0, %0, %1\n" + " mcr p15, 0, %0, c1, c0, 0\n" + " mrc p15, 0, %0, c1, c0, 1\n" + " orr %0, %0, #0x40\n" + " mcr p15, 0, %0, c1, c0, 1\n" + : "=&r" (v) + : "Ir" (CR_C) + : "cc"); +} + +static inline void platform_do_lowpower(unsigned int cpu, int *spurious) +{ + /* + * there is no power-control hardware on this platform, so all + * we can do is put the core into WFI; this is safe as the calling + * code will have already disabled interrupts + */ + for (;;) { + dsb(); + wfi(); + + /* + * Getting here, means that we have come out of WFI without + * having been woken up - this shouldn't happen + * + * Just note it happening - when we're woken, we can report + * its occurrence. + */ + (*spurious)++; + } +} + +/* + * platform-specific code to shutdown a CPU + * + * Called with IRQs disabled + */ +void platform_cpu_die(unsigned int cpu) +{ + int spurious = 0; + + /* + * we're ready for shutdown now, so do it + */ + cpu_enter_lowpower(); + platform_do_lowpower(cpu, &spurious); + + /* + * bring this CPU back into the world of cache + * coherency, and then restore interrupts + */ + cpu_leave_lowpower(); + + if (spurious) + pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious); +} diff --git a/arch/arm/mach-zynq/platsmp.c b/arch/arm/mach-zynq/platsmp.c index d31ef72..9757a2d 100644 --- a/arch/arm/mach-zynq/platsmp.c +++ b/arch/arm/mach-zynq/platsmp.c @@ -157,4 +157,7 @@ struct smp_operations zynq_smp_ops __initdata = { .smp_prepare_cpus = zynq_smp_prepare_cpus, .smp_secondary_init = zynq_secondary_init, .smp_boot_secondary = zynq_boot_secondary, +#ifdef CONFIG_HOTPLUG_CPU + .cpu_die = platform_cpu_die, +#endif };