/*******************************************************************************
* Top level handler which is called when a cpu wants to power itself down.
* It's assumed that along with turning the cpu off, higher affinity levels will
* be turned off as far as possible. It traverses through all the affinity
* levels performing generic, architectural, platform setup and state management
* e.g. for a cluster that's to be powered off, it will call the platform
* specific code which will disable coherency at the interconnect level if the
* cpu is the last in the cluster. For a cpu it could mean programming the power
* the power controller etc.
*
* The state of all the relevant affinity levels is changed prior to calling the
* affinity level specific handlers as their actions would depend upon the state
* the affinity level is about to enter.
*
* The affinity level specific handlers are called in ascending order i.e. from
* the lowest to the highest affinity level implemented by the platform because
* to turn off affinity level X it is neccesary to turn off affinity level X - 1
* first.
*
* CAUTION: This function is called with coherent stacks so that coherency can
* be turned off and caches can be flushed safely.
******************************************************************************/
int psci_afflvl_off(unsigned long mpidr,
int start_afflvl,
int end_afflvl)
{
int rc = PSCI_E_SUCCESS;
mpidr_aff_map_nodes mpidr_nodes;
mpidr &= MPIDR_AFFINITY_MASK;;
/*
* Collect the pointers to the nodes in the topology tree for
* each affinity instance in the mpidr. If this function does
* not return successfully then either the mpidr or the affinity
* levels are incorrect. In either case, we cannot return back
* to the caller as it would not know what to do.
*/
rc = psci_get_aff_map_nodes(mpidr,
start_afflvl,
end_afflvl,
mpidr_nodes);
assert (rc == PSCI_E_SUCCESS);
/*
* This function acquires the lock corresponding to each affinity
* level so that by the time all locks are taken, the system topology
* is snapshot and state management can be done safely.
*/
psci_acquire_afflvl_locks(mpidr,
start_afflvl,
end_afflvl,
mpidr_nodes);
/* Perform generic, architecture and platform specific handling */
rc = psci_call_off_handlers(mpidr_nodes,
start_afflvl,
end_afflvl,
mpidr);
/*
* Release the locks corresponding to each affinity level in the
* reverse order to which they were acquired.
*/
psci_release_afflvl_locks(mpidr,
start_afflvl,
end_afflvl,
mpidr_nodes);
return rc;
}
/*******************************************************************************
* Top level handler which is called when a cpu wants to power itself down.
* It's assumed that along with turning the cpu off, higher affinity levels will
* be turned off as far as possible. It traverses through all the affinity
* levels performing generic, architectural, platform setup and state management
* e.g. for a cluster that's to be powered off, it will call the platform
* specific code which will disable coherency at the interconnect level if the
* cpu is the last in the cluster. For a cpu it could mean programming the power
* the power controller etc.
*
* The state of all the relevant affinity levels is changed prior to calling the
* affinity level specific handlers as their actions would depend upon the state
* the affinity level is about to enter.
*
* The affinity level specific handlers are called in ascending order i.e. from
* the lowest to the highest affinity level implemented by the platform because
* to turn off affinity level X it is neccesary to turn off affinity level X - 1
* first.
******************************************************************************/
int psci_afflvl_off(int start_afflvl,
int end_afflvl)
{
int rc = PSCI_E_SUCCESS;
mpidr_aff_map_nodes_t mpidr_nodes;
unsigned int max_phys_off_afflvl;
/*
* Collect the pointers to the nodes in the topology tree for
* each affinity instance in the mpidr. If this function does
* not return successfully then either the mpidr or the affinity
* levels are incorrect. In either case, we cannot return back
* to the caller as it would not know what to do.
*/
rc = psci_get_aff_map_nodes(read_mpidr_el1() & MPIDR_AFFINITY_MASK,
start_afflvl,
end_afflvl,
mpidr_nodes);
assert (rc == PSCI_E_SUCCESS);
/*
* This function acquires the lock corresponding to each affinity
* level so that by the time all locks are taken, the system topology
* is snapshot and state management can be done safely.
*/
psci_acquire_afflvl_locks(start_afflvl,
end_afflvl,
mpidr_nodes);
/*
* This function updates the state of each affinity instance
* corresponding to the mpidr in the range of affinity levels
* specified.
*/
psci_do_afflvl_state_mgmt(start_afflvl,
end_afflvl,
mpidr_nodes,
PSCI_STATE_OFF);
max_phys_off_afflvl = psci_find_max_phys_off_afflvl(start_afflvl,
end_afflvl,
mpidr_nodes);
assert(max_phys_off_afflvl != PSCI_INVALID_DATA);
/* Stash the highest affinity level that will enter the OFF state. */
psci_set_max_phys_off_afflvl(max_phys_off_afflvl);
/* Perform generic, architecture and platform specific handling */
rc = psci_call_off_handlers(mpidr_nodes,
start_afflvl,
end_afflvl);
/*
* Invalidate the entry for the highest affinity level stashed earlier.
* This ensures that any reads of this variable outside the power
* up/down sequences return PSCI_INVALID_DATA.
*
*/
psci_set_max_phys_off_afflvl(PSCI_INVALID_DATA);
/*
* Release the locks corresponding to each affinity level in the
* reverse order to which they were acquired.
*/
psci_release_afflvl_locks(start_afflvl,
end_afflvl,
mpidr_nodes);
return rc;
}
