arm64: kernel: initialise cpu_logical_map from the DT

When booting the kernel, the cpu logical id map must be initialised
using device tree data passed by FW or through an embedded blob.

This patch parses the reg property in device tree "cpu" nodes,
retrieves the corresponding CPUs hardware identifiers (MPIDR) and
initialises the cpu logical map accordingly.

The device tree HW identifiers are considered valid if all CPU nodes
contain a "reg" property, there are no duplicate "reg" entries and the
DT defines a CPU node whose "reg" property defines affinity levels
that matches those of the boot CPU.

The primary CPU is assigned cpu logical number 0 to keep the current
convention valid.

Based on a0ae02405076ac32bd17ece976e914b5b6075bb0 (ARM: kernel: add
device tree init map function).

Signed-off-by: Javi Merino <javi.merino@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/arch/arm64/include/asm/smp_plat.h b/arch/arm64/include/asm/smp_plat.h
new file mode 100644
index 000000000000..ed43a0d2b1b2
--- /dev/null
+++ b/arch/arm64/include/asm/smp_plat.h
@@ -0,0 +1,30 @@
+/*
+ * Definitions specific to SMP platforms.
+ *
+ * Copyright (C) 2013 ARM Ltd.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __ASM_SMP_PLAT_H
+#define __ASM_SMP_PLAT_H
+
+#include <asm/types.h>
+
+/*
+ * Logical CPU mapping.
+ */
+extern u64 __cpu_logical_map[NR_CPUS];
+#define cpu_logical_map(cpu)    __cpu_logical_map[cpu]
+
+#endif /* __ASM_SMP_PLAT_H */