css: Ensure PSCI system off/reset is not interrupted

If there is a pending interrupt, it is possible for the AP to come out
of the final WFI before SCP has a chance to act on it.  Prevent this
by disabling the GIC CPU interface before issuing a WFI.

Previously, SCP would not wait on WFI before taking an action but
would shut down the core or system regardless.

Change-Id: Ib0bcf69a515d540ed4f73c11e40ec7c863e39c92
Signed-off-by: dp-arm <dimitris.papastamos@arm.com>
This commit is contained in:
dp-arm 2017-04-11 11:48:49 +01:00
parent 3d21c9452d
commit 0498343ac0
1 changed files with 13 additions and 0 deletions

View File

@ -32,6 +32,7 @@
#include <assert.h>
#include <css_pm.h>
#include <debug.h>
#include <plat_arm.h>
#include "../scpi/css_scpi.h"
#include "css_scp.h"
@ -134,6 +135,12 @@ void __dead2 css_scp_sys_shutdown(void)
{
uint32_t response;
/*
* Disable GIC CPU interface to prevent pending interrupt
* from waking up the AP from WFI.
*/
plat_arm_gic_cpuif_disable();
/* Send the power down request to the SCP */
response = scpi_sys_power_state(scpi_system_shutdown);
@ -153,6 +160,12 @@ void __dead2 css_scp_sys_reboot(void)
{
uint32_t response;
/*
* Disable GIC CPU interface to prevent pending interrupt
* from waking up the AP from WFI.
*/
plat_arm_gic_cpuif_disable();
/* Send the system reset request to the SCP */
response = scpi_sys_power_state(scpi_system_reboot);