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/*
* Copyright (C) 2002 ARM Ltd.
* All Rights Reserved
* Copyright (c) 2011-2012, The Linux Foundation. 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 <linux/kernel.h>
#include <linux/errno.h>
#include <linux/smp.h>
#include <linux/cpu.h>
#include <asm/cacheflush.h>
#include <asm/smp_plat.h>
#include <asm/vfp.h>
#include <mach/jtag.h>
#include <mach/msm_rtb.h>
#include "pm.h"
#include "spm.h"
extern volatile int pen_release;
struct msm_hotplug_device {
struct completion cpu_killed;
unsigned int warm_boot;
};
static DEFINE_PER_CPU_SHARED_ALIGNED(struct msm_hotplug_device,
msm_hotplug_devices);
static inline void cpu_enter_lowpower(void)
{
/* Just flush the cache. Changing the coherency is not yet
* available on msm. */
flush_cache_all();
}
static inline void cpu_leave_lowpower(void)
{
}
static inline void platform_do_lowpower(unsigned int cpu, int *spurious)
{
/* Just enter wfi for now. TODO: Properly shut off the cpu. */
for (;;) {
msm_pm_cpu_enter_lowpower(cpu);
if (pen_release == cpu_logical_map(cpu)) {
/*
* OK, proper wakeup, we're done
*/
break;
}
/*
* getting here, means that we have come out of WFI without
* having been woken up - this shouldn't happen
*
* The trouble is, letting people know about this is not really
* possible, since we are currently running incoherently, and
* therefore cannot safely call printk() or anything else
*/
(*spurious)++;
}
}
int platform_cpu_kill(unsigned int cpu)
{
return 1;
}
/*
* platform-specific code to shutdown a CPU
*
* Called with IRQs disabled
*/
void platform_cpu_die(unsigned int cpu)
{
int spurious = 0;
if (unlikely(cpu != smp_processor_id())) {
pr_crit("%s: running on %u, should be %u\n",
__func__, smp_processor_id(), cpu);
BUG();
}
complete(&__get_cpu_var(msm_hotplug_devices).cpu_killed);
/*
* we're ready for shutdown now, so do it
*/
cpu_enter_lowpower();
platform_do_lowpower(cpu, &spurious);
pr_debug("CPU%u: %s: normal wakeup\n", cpu, __func__);
cpu_leave_lowpower();
if (spurious)
pr_warn("CPU%u: %u spurious wakeup calls\n", cpu, spurious);
}
int platform_cpu_disable(unsigned int cpu)
{
/*
* we don't allow CPU 0 to be shutdown (it is still too special
* e.g. clock tick interrupts)
*/
return cpu == 0 ? -EPERM : 0;
}
#define CPU_SHIFT 0
#define CPU_MASK 0xF
#define CPU_OF(n) (((n) & CPU_MASK) << CPU_SHIFT)
#define CPUSET_SHIFT 4
#define CPUSET_MASK 0xFFFF
#define CPUSET_OF(n) (((n) & CPUSET_MASK) << CPUSET_SHIFT)
static int hotplug_rtb_callback(struct notifier_block *nfb,
unsigned long action, void *hcpu)
{
/*
* Bits [19:4] of the data are the online mask, lower 4 bits are the
* cpu number that is being changed. Additionally, changes to the
* online_mask that will be done by the current hotplug will be made
* even though they aren't necessarily in the online mask yet.
*
* XXX: This design is limited to supporting at most 16 cpus
*/
int this_cpumask = CPUSET_OF(1 << (int)hcpu);
int cpumask = CPUSET_OF(cpumask_bits(cpu_online_mask)[0]);
int cpudata = CPU_OF((int)hcpu) | cpumask;
switch (action & (~CPU_TASKS_FROZEN)) {
case CPU_STARTING:
uncached_logk(LOGK_HOTPLUG, (void *)(cpudata | this_cpumask));
break;
case CPU_DYING:
uncached_logk(LOGK_HOTPLUG, (void *)(cpudata & ~this_cpumask));
break;
default:
break;
}
return NOTIFY_OK;
}
static struct notifier_block hotplug_rtb_notifier = {
.notifier_call = hotplug_rtb_callback,
};
int msm_platform_secondary_init(unsigned int cpu)
{
int ret;
struct msm_hotplug_device *dev = &__get_cpu_var(msm_hotplug_devices);
if (!dev->warm_boot) {
dev->warm_boot = 1;
init_completion(&dev->cpu_killed);
return 0;
}
msm_jtag_restore_state();
#if defined(CONFIG_VFP) && defined (CONFIG_CPU_PM)
vfp_pm_resume();
#endif
ret = msm_spm_set_low_power_mode(MSM_SPM_MODE_CLOCK_GATING, false);
return ret;
}
static int __init init_hotplug(void)
{
struct msm_hotplug_device *dev = &__get_cpu_var(msm_hotplug_devices);
init_completion(&dev->cpu_killed);
return register_hotcpu_notifier(&hotplug_rtb_notifier);
}
early_initcall(init_hotplug);
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