/*
* cpu_suspend
*
* arg: argument to pass to the finisher function
* fn: finisher function pointer
*
*/
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
int ret;
unsigned long flags;
/*
* 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);
/*
* Function graph tracer state gets incosistent when the kernel
* calls functions that never return (aka suspend finishers) hence
* disable graph tracing during their execution.
*/
pause_graph_tracing();
/*
* 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_enter(arg, fn);
if (ret == 0) {
/*
* We are resuming from reset with the idmap active in TTBR0_EL1.
* We must uninstall the idmap and restore the expected MMU
* state before we can possibly return to userspace.
*/
cpu_uninstall_idmap();
/*
* Restore per-cpu offset before any kernel
* subsystem relying on it has a chance to run.
*/
set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
/*
* 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);
}
unpause_graph_tracing();
/*
* 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;
}
/**
* 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);
pclog();
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;
}
int swsusp_arch_suspend(void)
{
int ret = 0;
unsigned long flags;
struct sleep_stack_data state;
if (cpus_are_stuck_in_kernel()) {
pr_err("Can't hibernate: no mechanism to offline secondary CPUs.\n");
return -EBUSY;
}
local_dbg_save(flags);
if (__cpu_suspend_enter(&state)) {
sleep_cpu = smp_processor_id();
ret = swsusp_save();
} else {
/* Clean kernel core startup/idle code to PoC*/
dcache_clean_range(__mmuoff_data_start, __mmuoff_data_end);
dcache_clean_range(__idmap_text_start, __idmap_text_end);
/* Clean kvm setup code to PoC? */
if (el2_reset_needed())
dcache_clean_range(__hyp_idmap_text_start, __hyp_idmap_text_end);
/*
* Tell the hibernation core that we've just restored
* the memory
*/
in_suspend = 0;
sleep_cpu = -EINVAL;
__cpu_suspend_exit();
}
local_dbg_restore(flags);
return ret;
}
/*
* __cpu_suspend
*
* arg: argument to pass to the finisher function
* fn: finisher function pointer
*
*/
int __cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
struct mm_struct *mm = current->active_mm;
int ret;
unsigned long flags;
/*
* 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);
/*
* Function graph tracer state gets incosistent when the kernel
* calls functions that never return (aka suspend finishers) hence
* disable graph tracing during their execution.
*/
pause_graph_tracing();
/*
* 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_enter(arg, fn);
if (ret == 0) {
/*
* We are resuming from reset with TTBR0_EL1 set to the
* idmap to enable the MMU; restore the active_mm mappings in
* TTBR0_EL1 unless the active_mm == &init_mm, in which case
* the thread entered __cpu_suspend with TTBR0_EL1 set to
* reserved TTBR0 page tables and should be restored as such.
*/
if (mm == &init_mm)
cpu_set_reserved_ttbr0();
else
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(smp_processor_id()));
/*
* 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);
}
unpause_graph_tracing();
/*
* 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;
}
/*
* cpu_suspend
*
* arg: argument to pass to the finisher function
* fn: finisher function pointer
*
*/
int cpu_suspend(unsigned long arg, int (*fn)(unsigned long))
{
struct mm_struct *mm = current->active_mm;
int ret;
unsigned long flags;
/*
* 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_enter(arg, fn);
if (ret == 0) {
/*
* We are resuming from reset with TTBR0_EL1 set to the
* idmap to enable the MMU; set the TTBR0 to the reserved
* page tables to prevent speculative TLB allocations, flush
* the local tlb and set the default tcr_el1.t0sz so that
* the TTBR0 address space set-up is properly restored.
* If the current active_mm != &init_mm we entered cpu_suspend
* with mappings in TTBR0 that must be restored, so we switch
* them back to complete the address space configuration
* restoration before returning.
*/
cpu_set_reserved_ttbr0();
local_flush_tlb_all();
cpu_set_default_tcr_t0sz();
if (mm != &init_mm)
cpu_switch_mm(mm->pgd, mm);
/*
* Restore per-cpu offset before any kernel
* subsystem relying on it has a chance to run.
*/
set_my_cpu_offset(per_cpu_offset(smp_processor_id()));
/*
* 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;
}