b5b4f2881f
Program non-boot CPUs to hit lowest supported power state when it is off-lined using cpu hotplug framework. Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> Acked-by: Jean Pihet <j-pihet@ti.com> Reviewed-by: Kevin Hilman <khilman@ti.com> Tested-by: Vishwanath BS <vishwanath.bs@ti.com> Signed-off-by: Kevin Hilman <khilman@ti.com>
72 lines
1.5 KiB
C
72 lines
1.5 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 <asm/cacheflush.h>
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#include "common.h"
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#include "powerdomain.h"
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int platform_cpu_kill(unsigned int cpu)
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{
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return 1;
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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;
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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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pr_err("Secure clear status failed\n");
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for (;;) {
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/*
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* Enter into low power state
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*/
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omap4_hotplug_cpu(cpu, PWRDM_POWER_OFF);
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this_cpu = smp_processor_id();
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if (omap_read_auxcoreboot0() == this_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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