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PSCI: Lookup list of parent nodes to lock only once

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When acquiring or releasing the power domain locks for a given CPU the
parent nodes are looked up by walking the up the PD tree list on both the
acquire and release path, only one set of lookups is needed. Fetch the
parent nodes first and pass this list into both the acquire and release
functions to avoid the double lookup.

This also allows us to not have to do this lookup after coherency has
been exited during the core power down sequence. The shared struct
psci_cpu_pd_nodes is not placed in coherent memory like is done
for psci_non_cpu_pd_nodes and doing so would negatively affect
performance. With this patch we remove the need to have it in coherent
memory by moving the access out of psci_release_pwr_domain_locks().

Signed-off-by: Andrew F. Davis <afd@ti.com>
Change-Id: I7b9cfa9d31148dea0f5e21091c8b45ef7fe4c4ab
This commit is contained in:
Andrew F. Davis 2019-06-04 10:46:54 -04:00
parent 0f95565c40
commit 74d27d0062
4 changed files with 49 additions and 28 deletions
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21
lib/psci/psci_suspend.c
View file

@ -28,10 +28,13 @@
static void psci_suspend_to_standby_finisher(int cpu_idx,
unsigned int end_pwrlvl)
{
unsigned int parent_nodes[PLAT_MAX_PWR_LVL] = {0};
psci_power_state_t state_info;
psci_acquire_pwr_domain_locks(end_pwrlvl,
cpu_idx);
/* Get the parent nodes */
psci_get_parent_pwr_domain_nodes(cpu_idx, end_pwrlvl, parent_nodes);
psci_acquire_pwr_domain_locks(end_pwrlvl, parent_nodes);
/*
* Find out which retention states this CPU has exited from until the
@ -57,8 +60,7 @@ static void psci_suspend_to_standby_finisher(int cpu_idx,
*/
psci_set_pwr_domains_to_run(end_pwrlvl);
psci_release_pwr_domain_locks(end_pwrlvl,
cpu_idx);
psci_release_pwr_domain_locks(end_pwrlvl, parent_nodes);
}
/*******************************************************************************
@ -156,6 +158,7 @@ void psci_cpu_suspend_start(const entry_point_info_t *ep,
{
int skip_wfi = 0;
int idx = (int) plat_my_core_pos();
unsigned int parent_nodes[PLAT_MAX_PWR_LVL] = {0};
/*
* This function must only be called on platforms where the
@ -164,13 +167,15 @@ void psci_cpu_suspend_start(const entry_point_info_t *ep,
assert((psci_plat_pm_ops->pwr_domain_suspend != NULL) &&
(psci_plat_pm_ops->pwr_domain_suspend_finish != NULL));
/* Get the parent nodes */
psci_get_parent_pwr_domain_nodes(idx, end_pwrlvl, parent_nodes);
/*
* This function acquires the lock corresponding to each power
* level so that by the time all locks are taken, the system topology
* is snapshot and state management can be done safely.
*/
psci_acquire_pwr_domain_locks(end_pwrlvl,
idx);
psci_acquire_pwr_domain_locks(end_pwrlvl, parent_nodes);
/*
* We check if there are any pending interrupts after the delay
@ -214,8 +219,8 @@ exit:
* Release the locks corresponding to each power level in the
* reverse order to which they were acquired.
*/
psci_release_pwr_domain_locks(end_pwrlvl,
idx);
psci_release_pwr_domain_locks(end_pwrlvl, parent_nodes);
if (skip_wfi == 1)
return;