plat: imx8m: Fix the race condition during cpu hotplug
CPU hotplug & cpuidle have some race condition when doing CPU hotplug
stress test. different CPU cores have the chance to access the same
GPC register(A53_AD), so lock is necessary to do exlusive access.
Signed-off-by: Jacky Bai <ping.bai@nxp.com>
Change-Id: I1296592e05fa78429c3f0fac066951521db755e3
diff --git a/plat/imx/imx8m/imx8mq/gpc.c b/plat/imx/imx8m/imx8mq/gpc.c
index 942ae45..367c941 100644
--- a/plat/imx/imx8m/imx8mq/gpc.c
+++ b/plat/imx/imx8m/imx8mq/gpc.c
@@ -19,9 +19,14 @@
/* use wfi power down the core */
void imx_set_cpu_pwr_off(unsigned int core_id)
{
+ bakery_lock_get(&gpc_lock);
+
/* enable the wfi power down of the core */
mmio_setbits_32(IMX_GPC_BASE + LPCR_A53_AD, COREx_WFI_PDN(core_id) |
(1 << (core_id + 20)));
+
+ bakery_lock_release(&gpc_lock);
+
/* assert the pcg pcr bit of the core */
mmio_setbits_32(IMX_GPC_BASE + COREx_PGC_PCR(core_id), 0x1);
};
@@ -29,6 +34,8 @@
/* if out of lpm, we need to do reverse steps */
void imx_set_cpu_lpm(unsigned int core_id, bool pdn)
{
+ bakery_lock_get(&gpc_lock);
+
if (pdn) {
/* enable the core WFI PDN & IRQ PUP */
mmio_setbits_32(IMX_GPC_BASE + LPCR_A53_AD, COREx_WFI_PDN(core_id) |
@@ -42,6 +49,8 @@
/* deassert the pcg pcr bit of the core */
mmio_setbits_32(IMX_GPC_BASE + COREx_PGC_PCR(core_id), 0x1);
}
+
+ bakery_lock_release(&gpc_lock);
}
void imx_pup_pdn_slot_config(int last_core, bool pdn)