refactor(st): move GIC code to common directory

The GIC v2 initialization code could be shared to other ST platforms.
The stm32mp1_gic.c file is then moved to common directory, and renamed
stm32mp_gic.c.
The functions are also prefixed with stm32mp_gic.

Change-Id: I60820823b470217d3a95cc569f941c2cb923dfa9
Signed-off-by: Yann Gautier <yann.gautier@st.com>
diff --git a/plat/st/common/stm32mp_gic.c b/plat/st/common/stm32mp_gic.c
new file mode 100644
index 0000000..d02b635
--- /dev/null
+++ b/plat/st/common/stm32mp_gic.c
@@ -0,0 +1,91 @@
+/*
+ * Copyright (c) 2016-2023, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <common/bl_common.h>
+#include <common/debug.h>
+#include <drivers/arm/gicv2.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+#include <lib/utils.h>
+#include <libfdt.h>
+#include <plat/common/platform.h>
+
+#include <platform_def.h>
+
+struct stm32mp_gic_instance {
+	uint32_t cells;
+	uint32_t phandle_node;
+};
+
+/******************************************************************************
+ * On a GICv2 system, the Group 1 secure interrupts are treated as Group 0
+ * interrupts.
+ *****************************************************************************/
+static const interrupt_prop_t stm32mp_interrupt_props[] = {
+	PLATFORM_G1S_PROPS(GICV2_INTR_GROUP0),
+	PLATFORM_G0_PROPS(GICV2_INTR_GROUP0)
+};
+
+/* Fix target_mask_array as secondary core is not able to initialize it */
+static unsigned int target_mask_array[PLATFORM_CORE_COUNT] = {1, 2};
+
+static gicv2_driver_data_t platform_gic_data = {
+	.interrupt_props = stm32mp_interrupt_props,
+	.interrupt_props_num = ARRAY_SIZE(stm32mp_interrupt_props),
+	.target_masks = target_mask_array,
+	.target_masks_num = ARRAY_SIZE(target_mask_array),
+};
+
+static struct stm32mp_gic_instance stm32mp_gic;
+
+void stm32mp_gic_init(void)
+{
+	int node;
+	void *fdt;
+	const fdt32_t *cuint;
+	struct dt_node_info dt_gic;
+
+	if (fdt_get_address(&fdt) == 0) {
+		panic();
+	}
+
+	node = dt_get_node(&dt_gic, -1, "arm,cortex-a7-gic");
+	if (node < 0) {
+		panic();
+	}
+
+	platform_gic_data.gicd_base = dt_gic.base;
+
+	cuint = fdt_getprop(fdt, node, "reg", NULL);
+	if (cuint == NULL) {
+		panic();
+	}
+
+	platform_gic_data.gicc_base = fdt32_to_cpu(*(cuint + 2));
+
+	cuint = fdt_getprop(fdt, node, "#interrupt-cells", NULL);
+	if (cuint == NULL) {
+		panic();
+	}
+
+	stm32mp_gic.cells = fdt32_to_cpu(*cuint);
+
+	stm32mp_gic.phandle_node = fdt_get_phandle(fdt, node);
+	if (stm32mp_gic.phandle_node == 0U) {
+		panic();
+	}
+
+	gicv2_driver_init(&platform_gic_data);
+	gicv2_distif_init();
+
+	stm32mp_gic_pcpu_init();
+}
+
+void stm32mp_gic_pcpu_init(void)
+{
+	gicv2_pcpu_distif_init();
+	gicv2_set_pe_target_mask(plat_my_core_pos());
+	gicv2_cpuif_enable();
+}