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Juno: Add support for PSCI cpu_suspend api 

This patch adds support for the PSCI cpu_suspend api to allow entry
into low power states until affinity level 1 i.e. cluster. It mainly
ensures that a consolidated power off command which specifies the
level to which each affinity level should be powered down is sent to
the SCP.

Change-Id: I84201f5c06e9c41c9e1fbc6438d12ab5f65ee429
This commit is contained in:
Achin Gupta 2014-08-12 14:13:31 +01:00
parent c0481acec1
commit e726c122b5
1 changed files with 134 additions and 29 deletions
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163
plat/juno/plat_pm.c
View File

@ -28,6 +28,7 @@
* POSSIBILITY OF SUCH DAMAGE.
*/
#include <assert.h>
#include <arch_helpers.h>
#include <cci400.h>
#include <platform.h>
@ -37,6 +38,13 @@
#include "juno_private.h"
#include "scpi.h"
typedef struct {
/* Align the suspend level to allow per-cpu lockless access */
uint32_t state[MPIDR_MAX_AFFLVL] __aligned(CACHE_WRITEBACK_GRANULE);
} scp_pstate;
static scp_pstate target_pstate[PLATFORM_CORE_COUNT];
int pm_on(unsigned long mpidr,
unsigned long sec_entrypoint,
unsigned long ns_entrypoint,
@ -90,12 +98,86 @@ int pm_on_finish(unsigned long mpidr, unsigned int afflvl, unsigned int state)
/* Juno todo: Is this setup only needed after a cold boot? */
gic_pcpu_distif_setup(GICD_BASE);
/*
* Clear the mailbox for each cpu
*/
unsigned long *mbox = (unsigned long *)(unsigned long)(
TRUSTED_MAILBOXES_BASE +
(platform_get_core_pos(mpidr) << TRUSTED_MAILBOX_SHIFT)
);
*mbox = 0;
flush_dcache_range((unsigned long)mbox, sizeof(*mbox));
break;
}
return PSCI_E_SUCCESS;
}
/*******************************************************************************
* Common function called while turning a cpu off or suspending it. It is called
* for each affinity level until the target affinity level. It keeps track of
* the power state that needs to be programmed through the SCP firmware for each
* affinity level. Once the target affinity level is reached it uses the MHU
* channel to ask the SCP to perform the power operations for each affinity
* level accumulated so far.
*
* CAUTION: There is no guarantee that caches will remain turned on across calls
* to this function as each affinity level is dealt with. So do not write & read
* global variables across calls. It will be wise to do flush a write to the
* global to prevent unpredictable results.
******************************************************************************/
static int juno_power_down_common(unsigned long mpidr,
unsigned int linear_id,
unsigned int cur_afflvl,
unsigned int tgt_afflvl,
unsigned int state)
{
/* Record which power state this affinity level is supposed to enter */
if (state == PSCI_STATE_OFF) {
target_pstate[linear_id].state[cur_afflvl] = scpi_power_off;
} else {
assert(cur_afflvl != MPIDR_AFFLVL0);
target_pstate[linear_id].state[cur_afflvl] = scpi_power_on;
goto exit;
}
switch (cur_afflvl) {
case MPIDR_AFFLVL1:
/* Cluster is to be turned off, so disable coherency */
cci_disable_coherency(mpidr);
break;
case MPIDR_AFFLVL0:
/* Turn off intra-cluster coherency */
write_cpuectlr(read_cpuectlr() & ~CPUECTLR_SMP_BIT);
/* Prevent interrupts from spuriously waking up this cpu */
gic_cpuif_deactivate(GICC_BASE);
break;
}
exit:
/*
* If this is the target affinity level then we need to ask the SCP
* to power down the appropriate components depending upon their state
*/
if (cur_afflvl == tgt_afflvl) {
scpi_set_css_power_state(mpidr,
target_pstate[linear_id].state[MPIDR_AFFLVL0],
target_pstate[linear_id].state[MPIDR_AFFLVL1],
scpi_power_on);
/* Reset the states */
target_pstate[linear_id].state[MPIDR_AFFLVL0] = scpi_power_on;
target_pstate[linear_id].state[MPIDR_AFFLVL1] = scpi_power_on;
}
return PSCI_E_SUCCESS;
}
/*******************************************************************************
* Handler called when an affinity instance is about to be turned off. The
* level and mpidr determine the affinity instance. The 'state' arg. allows the
@ -109,39 +191,60 @@ int pm_on_finish(unsigned long mpidr, unsigned int afflvl, unsigned int state)
******************************************************************************/
int pm_off(unsigned long mpidr, unsigned int afflvl, unsigned int state)
{
/* We're only interested in power off states */
if (state != PSCI_STATE_OFF)
return PSCI_E_SUCCESS;
return juno_power_down_common(mpidr,
platform_get_core_pos(mpidr),
afflvl,
plat_get_max_afflvl(),
state);
}
switch (afflvl) {
case MPIDR_AFFLVL1:
/* Cluster is to be turned off, so disable coherency */
cci_disable_coherency(mpidr);
/*******************************************************************************
* Handler called when an affinity instance is about to be suspended. The
* level and mpidr determine the affinity instance. The 'state' arg. allows the
* platform to decide whether the cluster is being turned off and take apt
* actions. The 'sec_entrypoint' determines the address in BL3-1 from where
* execution should resume.
*
* CAUTION: There is no guarantee that caches will remain turned on across calls
* to this function as each affinity level is dealt with. So do not write & read
* global variables across calls. It will be wise to do flush a write to the
* global to prevent unpredictable results.
******************************************************************************/
int pm_suspend(unsigned long mpidr,
unsigned long sec_entrypoint,
unsigned long ns_entrypoint,
unsigned int afflvl,
unsigned int state)
{
uint32_t tgt_afflvl;
break;
tgt_afflvl = psci_get_suspend_afflvl(mpidr);
assert(tgt_afflvl != PSCI_INVALID_DATA);
case MPIDR_AFFLVL0:
/* Turn off intra-cluster coherency */
write_cpuectlr(read_cpuectlr() & ~CPUECTLR_SMP_BIT);
/* Prevent interrupts from spuriously waking up this cpu */
gic_cpuif_deactivate(GICC_BASE);
/*
* Ask SCP to power down CPU.
*
* Note, we also ask for cluster power down as well because we
* know the SCP will only actually do that if this is the last
* CPU going down, and also, that final power down won't happen
* until this CPU executes the WFI instruction after the PSCI
* framework has done it's thing.
*/
scpi_set_css_power_state(mpidr, scpi_power_off, scpi_power_off,
scpi_power_retention);
break;
/*
* Setup mailbox with address for CPU entrypoint when it next powers up
*/
if (afflvl == MPIDR_AFFLVL0) {
unsigned long *mbox = (unsigned long *)(unsigned long)(
TRUSTED_MAILBOXES_BASE +
(platform_get_core_pos(mpidr) << TRUSTED_MAILBOX_SHIFT)
);
*mbox = sec_entrypoint;
flush_dcache_range((unsigned long)mbox, sizeof(*mbox));
}
return PSCI_E_SUCCESS;
return juno_power_down_common(mpidr,
platform_get_core_pos(mpidr),
afflvl,
tgt_afflvl,
state);
}
int pm_suspend_finish(unsigned long mpidr,
unsigned int afflvl,
unsigned int state)
{
return pm_on_finish(mpidr, afflvl, state);
}
/*******************************************************************************
@ -150,7 +253,9 @@ int pm_off(unsigned long mpidr, unsigned int afflvl, unsigned int state)
static const plat_pm_ops_t pm_ops = {
.affinst_on = pm_on,
.affinst_on_finish = pm_on_finish,
.affinst_off = pm_off
.affinst_off = pm_off,
.affinst_suspend = pm_suspend,
.affinst_suspend_finish = pm_suspend_finish
};
/*******************************************************************************