allwinner: Use the arisc to turn off ARM cores
PSCI requires a core to turn itself off, which we can't do properly by
just executing an algorithm on that very core. As a consequence we just
put a core into WFI on CPU_OFF right now.
To fix this let's task the "arisc" management processor (an OpenRISC
core) with that task of asserting reset and turning off the core's power
domain. We use a handcrafted sequence of OpenRISC instructions to
achieve this, and hand this data over to the new sunxi_execute_arisc_code()
routine.
The commented source code for this routine is provided in a separate file,
but the ATF code contains the already encoded instructions as data.
The H6 uses the same algorithm, but differs in the MMIO addresses, so
provide a SoC (family) specific copy of that code.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/plat/allwinner/common/sunxi_pm.c b/plat/allwinner/common/sunxi_pm.c
index 86336f0..7d13cda 100644
--- a/plat/allwinner/common/sunxi_pm.c
+++ b/plat/allwinner/common/sunxi_pm.c
@@ -42,6 +42,16 @@
gicv2_cpuif_disable();
}
+static void __dead2 sunxi_pwr_down_wfi(const psci_power_state_t *target_state)
+{
+ u_register_t mpidr = read_mpidr();
+
+ sunxi_cpu_off(MPIDR_AFFLVL1_VAL(mpidr), MPIDR_AFFLVL0_VAL(mpidr));
+
+ while (1)
+ wfi();
+}
+
static void sunxi_pwr_domain_on_finish(const psci_power_state_t *target_state)
{
gicv2_pcpu_distif_init();
@@ -82,6 +92,7 @@
static plat_psci_ops_t sunxi_psci_ops = {
.pwr_domain_on = sunxi_pwr_domain_on,
.pwr_domain_off = sunxi_pwr_domain_off,
+ .pwr_domain_pwr_down_wfi = sunxi_pwr_down_wfi,
.pwr_domain_on_finish = sunxi_pwr_domain_on_finish,
.system_off = sunxi_system_off,
.system_reset = sunxi_system_reset,