[U-Boot] [PATCH 2/2] armv8: ls1043a: Discard the needless cpu nodes

[Wenbin song]

Using "cpu_pos_mask()" function to detect the real online cpus,
and discard the needless cpu nodes on kernel dft.

Signed-off-by: Wenbin Song <wenbin.song at nxp.com>
---
 arch/arm/cpu/armv8/fsl-layerscape/Kconfig |  4 ++++
 arch/arm/cpu/armv8/fsl-layerscape/fdt.c   | 32 +++++++++++++++++++++++++++++++
 2 files changed, 36 insertions(+)

diff --git a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
index 47145a2432..971a98c6cc 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
+++ b/arch/arm/cpu/armv8/fsl-layerscape/Kconfig
@@ -176,6 +176,10 @@ config HAS_FEATURE_ENHANCED_MSI
 	bool
 	default y if ARCH_LS1043A
 
+config DISCARD_OFFLINE_CPU_NODES
+	bool
+	default y if ARCH_LS1043A
+
 menu "Layerscape PPA"
 config FSL_LS_PPA
 	bool "FSL Layerscape PPA firmware support"
diff --git a/arch/arm/cpu/armv8/fsl-layerscape/fdt.c b/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
index 33f3e64848..241f0abe18 100644
--- a/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
+++ b/arch/arm/cpu/armv8/fsl-layerscape/fdt.c
@@ -44,6 +44,38 @@ void ft_fixup_cpu(void *blob)
 	int addr_cells;
 	u64 val, core_id;
 	size_t *boot_code_size = &(__secondary_boot_code_size);
+
+#if defined(CONFIG_DISCARD_OFFLINE_CPU_NODES)
+	u32 mask = cpu_pos_mask();
+	int off_prev = -1;
+	int pos;
+
+	off = fdt_path_offset(blob, "/cpus");
+	if (off < 0) {
+		puts("couldn't find /cpus node\n");
+		return;
+	}
+
+	fdt_support_default_count_cells(blob, off, &addr_cells, NULL);
+
+	off = fdt_node_offset_by_prop_value(blob, off_prev, "device_type",
+					    "cpu", 4);
+	while (off != -FDT_ERR_NOTFOUND) {
+		reg = (fdt32_t *)fdt_getprop(blob, off, "reg", 0);
+		if (reg) {
+			core_id = fdt_read_number(reg, addr_cells);
+			pos = ((core_id & 0xff00) >> 5) + (core_id & 0xff);
+			if (!test_bit(pos, &mask)) {
+				fdt_del_node(blob, off);
+				off = off_prev;
+			}
+		}
+		off_prev = off;
+		off = fdt_node_offset_by_prop_value(blob, off_prev,
+						    "device_type", "cpu", 4);
+	}
+#endif
+
 #if defined(CONFIG_ARMV8_SEC_FIRMWARE_SUPPORT) && \
 	defined(CONFIG_SEC_FIRMWARE_ARMV8_PSCI)
 	int node;
-- 
2.14.1