mirror of https://gitee.com/openkylin/linux.git
141 lines
3.9 KiB
C
141 lines
3.9 KiB
C
#include <linux/percpu.h>
|
|
#include <linux/slab.h>
|
|
#include <asm/cacheflush.h>
|
|
#include <asm/cpu_ops.h>
|
|
#include <asm/debug-monitors.h>
|
|
#include <asm/pgtable.h>
|
|
#include <asm/memory.h>
|
|
#include <asm/smp_plat.h>
|
|
#include <asm/suspend.h>
|
|
#include <asm/tlbflush.h>
|
|
|
|
extern int __cpu_suspend(unsigned long);
|
|
/*
|
|
* This is called by __cpu_suspend() to save the state, and do whatever
|
|
* flushing is required to ensure that when the CPU goes to sleep we have
|
|
* the necessary data available when the caches are not searched.
|
|
*
|
|
* @arg: Argument to pass to suspend operations
|
|
* @ptr: CPU context virtual address
|
|
* @save_ptr: address of the location where the context physical address
|
|
* must be saved
|
|
*/
|
|
int __cpu_suspend_finisher(unsigned long arg, struct cpu_suspend_ctx *ptr,
|
|
phys_addr_t *save_ptr)
|
|
{
|
|
int cpu = smp_processor_id();
|
|
|
|
*save_ptr = virt_to_phys(ptr);
|
|
|
|
cpu_do_suspend(ptr);
|
|
/*
|
|
* Only flush the context that must be retrieved with the MMU
|
|
* off. VA primitives ensure the flush is applied to all
|
|
* cache levels so context is pushed to DRAM.
|
|
*/
|
|
__flush_dcache_area(ptr, sizeof(*ptr));
|
|
__flush_dcache_area(save_ptr, sizeof(*save_ptr));
|
|
|
|
return cpu_ops[cpu]->cpu_suspend(arg);
|
|
}
|
|
|
|
/*
|
|
* This hook is provided so that cpu_suspend code can restore HW
|
|
* breakpoints as early as possible in the resume path, before reenabling
|
|
* debug exceptions. Code cannot be run from a CPU PM notifier since by the
|
|
* time the notifier runs debug exceptions might have been enabled already,
|
|
* with HW breakpoints registers content still in an unknown state.
|
|
*/
|
|
void (*hw_breakpoint_restore)(void *);
|
|
void __init cpu_suspend_set_dbg_restorer(void (*hw_bp_restore)(void *))
|
|
{
|
|
/* Prevent multiple restore hook initializations */
|
|
if (WARN_ON(hw_breakpoint_restore))
|
|
return;
|
|
hw_breakpoint_restore = hw_bp_restore;
|
|
}
|
|
|
|
/**
|
|
* cpu_suspend
|
|
*
|
|
* @arg: argument to pass to the finisher function
|
|
*/
|
|
int cpu_suspend(unsigned long arg)
|
|
{
|
|
struct mm_struct *mm = current->active_mm;
|
|
int ret, cpu = smp_processor_id();
|
|
unsigned long flags;
|
|
|
|
/*
|
|
* If cpu_ops have not been registered or suspend
|
|
* has not been initialized, cpu_suspend call fails early.
|
|
*/
|
|
if (!cpu_ops[cpu] || !cpu_ops[cpu]->cpu_suspend)
|
|
return -EOPNOTSUPP;
|
|
|
|
/*
|
|
* From this point debug exceptions are disabled to prevent
|
|
* updates to mdscr register (saved and restored along with
|
|
* general purpose registers) from kernel debuggers.
|
|
*/
|
|
local_dbg_save(flags);
|
|
|
|
/*
|
|
* mm context saved on the stack, it will be restored when
|
|
* the cpu comes out of reset through the identity mapped
|
|
* page tables, so that the thread address space is properly
|
|
* set-up on function return.
|
|
*/
|
|
ret = __cpu_suspend(arg);
|
|
if (ret == 0) {
|
|
cpu_switch_mm(mm->pgd, mm);
|
|
flush_tlb_all();
|
|
|
|
/*
|
|
* Restore per-cpu offset before any kernel
|
|
* subsystem relying on it has a chance to run.
|
|
*/
|
|
set_my_cpu_offset(per_cpu_offset(cpu));
|
|
|
|
/*
|
|
* Restore HW breakpoint registers to sane values
|
|
* before debug exceptions are possibly reenabled
|
|
* through local_dbg_restore.
|
|
*/
|
|
if (hw_breakpoint_restore)
|
|
hw_breakpoint_restore(NULL);
|
|
}
|
|
|
|
/*
|
|
* Restore pstate flags. OS lock and mdscr have been already
|
|
* restored, so from this point onwards, debugging is fully
|
|
* renabled if it was enabled when core started shutdown.
|
|
*/
|
|
local_dbg_restore(flags);
|
|
|
|
return ret;
|
|
}
|
|
|
|
extern struct sleep_save_sp sleep_save_sp;
|
|
extern phys_addr_t sleep_idmap_phys;
|
|
|
|
static int __init cpu_suspend_init(void)
|
|
{
|
|
void *ctx_ptr;
|
|
|
|
/* ctx_ptr is an array of physical addresses */
|
|
ctx_ptr = kcalloc(mpidr_hash_size(), sizeof(phys_addr_t), GFP_KERNEL);
|
|
|
|
if (WARN_ON(!ctx_ptr))
|
|
return -ENOMEM;
|
|
|
|
sleep_save_sp.save_ptr_stash = ctx_ptr;
|
|
sleep_save_sp.save_ptr_stash_phys = virt_to_phys(ctx_ptr);
|
|
sleep_idmap_phys = virt_to_phys(idmap_pg_dir);
|
|
__flush_dcache_area(&sleep_save_sp, sizeof(struct sleep_save_sp));
|
|
__flush_dcache_area(&sleep_idmap_phys, sizeof(sleep_idmap_phys));
|
|
|
|
return 0;
|
|
}
|
|
early_initcall(cpu_suspend_init);
|