ARM platforms: enable GICv3 state save/restore
Provides GICv3 save/restore feature to arm_system_pwr_domain_resume and
arm_system_pwr_domain_save functions.
Introduce FVP PSCI power level 3 (System level) support. This is solely
done to provide example code on how to use the GICv3 save and restore
helpers.
Also make CSS GICv3 platforms power off the Redistributor on SYSTEM
SUSPEND as its state is saved and restored.
Change-Id: I0d852f3af8824edee1a17c085cf593ddd33a4e77
Signed-off-by: Soby Mathew <soby.mathew@arm.com>
Co-Authored-by: Douglas Raillard <douglas.raillard@arm.com>
diff --git a/plat/arm/common/arm_gicv3.c b/plat/arm/common/arm_gicv3.c
index c9bba09..67d5245 100644
--- a/plat/arm/common/arm_gicv3.c
+++ b/plat/arm/common/arm_gicv3.c
@@ -36,6 +36,13 @@
};
/*
+ * We save and restore the GICv3 context on system suspend. Allocate the
+ * data in the designated EL3 Secure carve-out memory
+ */
+gicv3_redist_ctx_t rdist_ctx __section("arm_el3_tzc_dram");
+gicv3_dist_ctx_t dist_ctx __section("arm_el3_tzc_dram");
+
+/*
* MPIDR hashing function for translating MPIDRs read from GICR_TYPER register
* to core position.
*
@@ -127,3 +134,58 @@
{
gicv3_rdistif_off(plat_my_core_pos());
}
+
+/******************************************************************************
+ * ARM common helper to save & restore the GICv3 on resume from system suspend
+ *****************************************************************************/
+void plat_arm_gic_save(void)
+{
+
+ /*
+ * If an ITS is available, save its context before
+ * the Redistributor using:
+ * gicv3_its_save_disable(gits_base, &its_ctx[i])
+ * Additionnaly, an implementation-defined sequence may
+ * be required to save the whole ITS state.
+ */
+
+ /*
+ * Save the GIC Redistributors and ITS contexts before the
+ * Distributor context. As we only handle SYSTEM SUSPEND API,
+ * we only need to save the context of the CPU that is issuing
+ * the SYSTEM SUSPEND call, i.e. the current CPU.
+ */
+ gicv3_rdistif_save(plat_my_core_pos(), &rdist_ctx);
+
+ /* Save the GIC Distributor context */
+ gicv3_distif_save(&dist_ctx);
+
+ /*
+ * From here, all the components of the GIC can be safely powered down
+ * as long as there is an alternate way to handle wakeup interrupt
+ * sources.
+ */
+}
+
+void plat_arm_gic_resume(void)
+{
+ /* Restore the GIC Distributor context */
+ gicv3_distif_init_restore(&dist_ctx);
+
+ /*
+ * Restore the GIC Redistributor and ITS contexts after the
+ * Distributor context. As we only handle SYSTEM SUSPEND API,
+ * we only need to restore the context of the CPU that issued
+ * the SYSTEM SUSPEND call.
+ */
+ gicv3_rdistif_init_restore(plat_my_core_pos(), &rdist_ctx);
+
+ /*
+ * If an ITS is available, restore its context after
+ * the Redistributor using:
+ * gicv3_its_restore(gits_base, &its_ctx[i])
+ * An implementation-defined sequence may be required to
+ * restore the whole ITS state. The ITS must also be
+ * re-enabled after this sequence has been executed.
+ */
+}