mirror of https://gitee.com/openkylin/linux.git
114 lines
3.1 KiB
C
114 lines
3.1 KiB
C
/*
|
|
* arch/arm/common/mcpm_entry.c -- entry point for multi-cluster PM
|
|
*
|
|
* Created by: Nicolas Pitre, March 2012
|
|
* Copyright: (C) 2012-2013 Linaro Limited
|
|
*
|
|
* 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/init.h>
|
|
#include <linux/irqflags.h>
|
|
|
|
#include <asm/mcpm.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/idmap.h>
|
|
|
|
extern unsigned long mcpm_entry_vectors[MAX_NR_CLUSTERS][MAX_CPUS_PER_CLUSTER];
|
|
|
|
void mcpm_set_entry_vector(unsigned cpu, unsigned cluster, void *ptr)
|
|
{
|
|
unsigned long val = ptr ? virt_to_phys(ptr) : 0;
|
|
mcpm_entry_vectors[cluster][cpu] = val;
|
|
sync_cache_w(&mcpm_entry_vectors[cluster][cpu]);
|
|
}
|
|
|
|
static const struct mcpm_platform_ops *platform_ops;
|
|
|
|
int __init mcpm_platform_register(const struct mcpm_platform_ops *ops)
|
|
{
|
|
if (platform_ops)
|
|
return -EBUSY;
|
|
platform_ops = ops;
|
|
return 0;
|
|
}
|
|
|
|
int mcpm_cpu_power_up(unsigned int cpu, unsigned int cluster)
|
|
{
|
|
if (!platform_ops)
|
|
return -EUNATCH; /* try not to shadow power_up errors */
|
|
might_sleep();
|
|
return platform_ops->power_up(cpu, cluster);
|
|
}
|
|
|
|
typedef void (*phys_reset_t)(unsigned long);
|
|
|
|
void mcpm_cpu_power_down(void)
|
|
{
|
|
phys_reset_t phys_reset;
|
|
|
|
BUG_ON(!platform_ops);
|
|
BUG_ON(!irqs_disabled());
|
|
|
|
/*
|
|
* Do this before calling into the power_down method,
|
|
* as it might not always be safe to do afterwards.
|
|
*/
|
|
setup_mm_for_reboot();
|
|
|
|
platform_ops->power_down();
|
|
|
|
/*
|
|
* It is possible for a power_up request to happen concurrently
|
|
* with a power_down request for the same CPU. In this case the
|
|
* power_down method might not be able to actually enter a
|
|
* powered down state with the WFI instruction if the power_up
|
|
* method has removed the required reset condition. The
|
|
* power_down method is then allowed to return. We must perform
|
|
* a re-entry in the kernel as if the power_up method just had
|
|
* deasserted reset on the CPU.
|
|
*
|
|
* To simplify race issues, the platform specific implementation
|
|
* must accommodate for the possibility of unordered calls to
|
|
* power_down and power_up with a usage count. Therefore, if a
|
|
* call to power_up is issued for a CPU that is not down, then
|
|
* the next call to power_down must not attempt a full shutdown
|
|
* but only do the minimum (normally disabling L1 cache and CPU
|
|
* coherency) and return just as if a concurrent power_up request
|
|
* had happened as described above.
|
|
*/
|
|
|
|
phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
|
|
phys_reset(virt_to_phys(mcpm_entry_point));
|
|
|
|
/* should never get here */
|
|
BUG();
|
|
}
|
|
|
|
void mcpm_cpu_suspend(u64 expected_residency)
|
|
{
|
|
phys_reset_t phys_reset;
|
|
|
|
BUG_ON(!platform_ops);
|
|
BUG_ON(!irqs_disabled());
|
|
|
|
/* Very similar to mcpm_cpu_power_down() */
|
|
setup_mm_for_reboot();
|
|
platform_ops->suspend(expected_residency);
|
|
phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
|
|
phys_reset(virt_to_phys(mcpm_entry_point));
|
|
BUG();
|
|
}
|
|
|
|
int mcpm_cpu_powered_up(void)
|
|
{
|
|
if (!platform_ops)
|
|
return -EUNATCH;
|
|
if (platform_ops->powered_up)
|
|
platform_ops->powered_up();
|
|
return 0;
|
|
}
|