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[178.255.168.63]) by mx.google.com with ESMTPS id bk1sm4809446wib.2.2013.03.26.10.44.06 (version=TLSv1.1 cipher=RC4-SHA bits=128/128); Tue, 26 Mar 2013 10:44:07 -0700 (PDT) From: Michal Simek To: linux-arm-kernel@lists.infradead.org, monstr@monstr.eu, Josh Cartwright , Steffen Trumtrar , Rob Herring Subject: [PATCH v2 09/10] arm: zynq: Add hotplug support Date: Tue, 26 Mar 2013 18:43:41 +0100 Message-Id: X-Mailer: git-send-email 1.7.9.7 In-Reply-To: <1364319822-5504-1-git-send-email-michal.simek@xilinx.com> References: <1364319822-5504-1-git-send-email-michal.simek@xilinx.com> In-Reply-To: References: X-Gm-Message-State: ALoCoQnY8nQyqZRWlBbc3mCfhf1brZH0fQwn55Afamf/10V2z0j7/jI+ghtjw9tAHwAw8lepX3im X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20130326_134412_730286_7FD60663 X-CRM114-Status: GOOD ( 16.38 ) 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 --- v2: Change platform_cpu_die name function to zynq_platform_cpu_dio Fix header Add cpu compilation flags to be able to build on V6 too --- arch/arm/mach-zynq/Makefile | 3 ++ arch/arm/mach-zynq/common.h | 3 ++ arch/arm/mach-zynq/hotplug.c | 104 ++++++++++++++++++++++++++++++++++++++++++ arch/arm/mach-zynq/platsmp.c | 3 ++ 4 files changed, 113 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 b595d22..1b25d92 100644 --- a/arch/arm/mach-zynq/Makefile +++ b/arch/arm/mach-zynq/Makefile @@ -4,4 +4,7 @@ # Common support obj-y := common.o slcr.o +CFLAGS_REMOVE_hotplug.o =-march=armv6k +CFLAGS_hotplug.o =-Wa,-march=armv7-a -mcpu=cortex-a9 +obj-$(CONFIG_HOTPLUG_CPU) += hotplug.o obj-$(CONFIG_SMP) += headsmp.o platsmp.o diff --git a/arch/arm/mach-zynq/common.h b/arch/arm/mach-zynq/common.h index 33cdc23..7a1eaec 100644 --- a/arch/arm/mach-zynq/common.h +++ b/arch/arm/mach-zynq/common.h @@ -34,4 +34,7 @@ extern struct smp_operations zynq_smp_ops __initdata; extern void __iomem *zynq_slcr_base; extern void __iomem *scu_base; +/* Hotplug */ +extern void zynq_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..64e3d6ec --- /dev/null +++ b/arch/arm/mach-zynq/hotplug.c @@ -0,0 +1,104 @@ +/* + * Copyright (C) 2012-2013 Xilinx + * + * based on 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 zynq_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 062b319..b1be091 100644 --- a/arch/arm/mach-zynq/platsmp.c +++ b/arch/arm/mach-zynq/platsmp.c @@ -146,4 +146,7 @@ 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 = zynq_platform_cpu_die, +#endif };