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https://git.kernel.org/pub/scm/linux/kernel/git/chenhuacai/linux-loongson
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7d35b8d09f
This patch adds cpu hotplug support for OMAP4430. Only CPU inactive state is supported as a low power state in the basic hot-plug support Signed-off-by: Rajendra Nayak <rnayak@ti.com> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Cc: Kevin Hilman <khilman@deeprootsystems.com> Signed-off-by: Tony Lindgren <tony@atomide.com>
80 lines
1.7 KiB
C
80 lines
1.7 KiB
C
/*
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* OMAP4 SMP cpu-hotplug support
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*
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* Copyright (C) 2010 Texas Instruments, Inc.
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* Author:
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* Santosh Shilimkar <santosh.shilimkar@ti.com>
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*
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* Platform file needed for the OMAP4 SMP. This file is based on arm
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* realview smp platform.
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* Copyright (c) 2002 ARM Limited.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*/
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/smp.h>
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#include <linux/completion.h>
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#include <asm/cacheflush.h>
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#include <mach/omap4-common.h>
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static DECLARE_COMPLETION(cpu_killed);
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int platform_cpu_kill(unsigned int cpu)
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{
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return wait_for_completion_timeout(&cpu_killed, 5000);
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}
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/*
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* platform-specific code to shutdown a CPU
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* Called with IRQs disabled
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*/
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void platform_cpu_die(unsigned int cpu)
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{
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unsigned int this_cpu = hard_smp_processor_id();
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if (cpu != this_cpu) {
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pr_crit("platform_cpu_die running on %u, should be %u\n",
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this_cpu, cpu);
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BUG();
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}
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pr_notice("CPU%u: shutdown\n", cpu);
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complete(&cpu_killed);
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flush_cache_all();
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dsb();
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/*
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* we're ready for shutdown now, so do it
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*/
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if (omap_modify_auxcoreboot0(0x0, 0x200) != 0x0)
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printk(KERN_CRIT "Secure clear status failed\n");
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for (;;) {
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/*
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* Execute WFI
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*/
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do_wfi();
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if (omap_read_auxcoreboot0() == cpu) {
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/*
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* OK, proper wakeup, we're done
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*/
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break;
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}
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pr_debug("CPU%u: spurious wakeup call\n", cpu);
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}
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}
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int platform_cpu_disable(unsigned int cpu)
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{
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/*
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* we don't allow CPU 0 to be shutdown (it is still too special
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* e.g. clock tick interrupts)
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*/
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return cpu == 0 ? -EPERM : 0;
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}
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