[PATCH v5 2/5] numa: Move numa implementation to common code

[Atish Patra <atish.patra@wdc.com>]

ARM64 numa implementation is generic enough that RISC-V can reuse that
implementation with very minor cosmetic changes. This will help both
ARM64 and RISC-V in terms of maintanace and feature improvement

Move the numa implementation code to common directory so that both ISAs
can reuse this. This doesn't introduce any function changes for ARM64.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Acked-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Tested-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
---
 arch/arm64/Kconfig                            |  1 +
 arch/arm64/include/asm/numa.h                 | 48 +----------------
 arch/arm64/mm/Makefile                        |  1 -
 drivers/base/Kconfig                          |  6 +++
 drivers/base/Makefile                         |  1 +
 .../mm/numa.c => drivers/base/arch_numa.c     |  0
 include/asm-generic/numa.h                    | 52 +++++++++++++++++++
 7 files changed, 61 insertions(+), 48 deletions(-)
 rename arch/arm64/mm/numa.c => drivers/base/arch_numa.c (100%)
 create mode 100644 include/asm-generic/numa.h

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 1515f6f153a0..4ebef80274fd 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -990,6 +990,7 @@ config HOTPLUG_CPU
 # Common NUMA Features
 config NUMA
 	bool "NUMA Memory Allocation and Scheduler Support"
+	select GENERIC_ARCH_NUMA
 	select ACPI_NUMA if ACPI
 	select OF_NUMA
 	help
diff --git a/arch/arm64/include/asm/numa.h b/arch/arm64/include/asm/numa.h
index ffc1dcdf1871..8c8cf4297cc3 100644
--- a/arch/arm64/include/asm/numa.h
+++ b/arch/arm64/include/asm/numa.h
@@ -3,52 +3,6 @@
 #define __ASM_NUMA_H
 
 #include <asm/topology.h>
-
-#ifdef CONFIG_NUMA
-
-#define NR_NODE_MEMBLKS		(MAX_NUMNODES * 2)
-
-int __node_distance(int from, int to);
-#define node_distance(a, b) __node_distance(a, b)
-
-extern nodemask_t numa_nodes_parsed __initdata;
-
-extern bool numa_off;
-
-/* Mappings between node number and cpus on that node. */
-extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
-void numa_clear_node(unsigned int cpu);
-
-#ifdef CONFIG_DEBUG_PER_CPU_MAPS
-const struct cpumask *cpumask_of_node(int node);
-#else
-/* Returns a pointer to the cpumask of CPUs on Node 'node'. */
-static inline const struct cpumask *cpumask_of_node(int node)
-{
-	if (node == NUMA_NO_NODE)
-		return cpu_all_mask;
-
-	return node_to_cpumask_map[node];
-}
-#endif
-
-void __init arch_numa_init(void);
-int __init numa_add_memblk(int nodeid, u64 start, u64 end);
-void __init numa_set_distance(int from, int to, int distance);
-void __init numa_free_distance(void);
-void __init early_map_cpu_to_node(unsigned int cpu, int nid);
-void numa_store_cpu_info(unsigned int cpu);
-void numa_add_cpu(unsigned int cpu);
-void numa_remove_cpu(unsigned int cpu);
-
-#else	/* CONFIG_NUMA */
-
-static inline void numa_store_cpu_info(unsigned int cpu) { }
-static inline void numa_add_cpu(unsigned int cpu) { }
-static inline void numa_remove_cpu(unsigned int cpu) { }
-static inline void arch_numa_init(void) { }
-static inline void early_map_cpu_to_node(unsigned int cpu, int nid) { }
-
-#endif	/* CONFIG_NUMA */
+#include <asm-generic/numa.h>
 
 #endif	/* __ASM_NUMA_H */
diff --git a/arch/arm64/mm/Makefile b/arch/arm64/mm/Makefile
index 5ead3c3de3b6..cd60e4fed78f 100644
--- a/arch/arm64/mm/Makefile
+++ b/arch/arm64/mm/Makefile
@@ -6,7 +6,6 @@ obj-y				:= dma-mapping.o extable.o fault.o init.o \
 obj-$(CONFIG_HUGETLB_PAGE)	+= hugetlbpage.o
 obj-$(CONFIG_PTDUMP_CORE)	+= ptdump.o
 obj-$(CONFIG_PTDUMP_DEBUGFS)	+= ptdump_debugfs.o
-obj-$(CONFIG_NUMA)		+= numa.o
 obj-$(CONFIG_DEBUG_VIRTUAL)	+= physaddr.o
 obj-$(CONFIG_ARM64_MTE)		+= mteswap.o
 KASAN_SANITIZE_physaddr.o	+= n
diff --git a/drivers/base/Kconfig b/drivers/base/Kconfig
index 8d7001712062..c5956c8845cc 100644
--- a/drivers/base/Kconfig
+++ b/drivers/base/Kconfig
@@ -210,4 +210,10 @@ config GENERIC_ARCH_TOPOLOGY
 	  appropriate scaling, sysfs interface for reading capacity values at
 	  runtime.
 
+config GENERIC_ARCH_NUMA
+	bool
+	help
+	  Enable support for generic NUMA implementation. Currently, RISC-V
+	  and ARM64 uses it.
+
 endmenu
diff --git a/drivers/base/Makefile b/drivers/base/Makefile
index 41369fc7004f..7d65ea07de65 100644
--- a/drivers/base/Makefile
+++ b/drivers/base/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_PINCTRL) += pinctrl.o
 obj-$(CONFIG_DEV_COREDUMP) += devcoredump.o
 obj-$(CONFIG_GENERIC_MSI_IRQ_DOMAIN) += platform-msi.o
 obj-$(CONFIG_GENERIC_ARCH_TOPOLOGY) += arch_topology.o
+obj-$(CONFIG_GENERIC_ARCH_NUMA) += arch_numa.o
 
 obj-y			+= test/
 
diff --git a/arch/arm64/mm/numa.c b/drivers/base/arch_numa.c
similarity index 100%
rename from arch/arm64/mm/numa.c
rename to drivers/base/arch_numa.c
diff --git a/include/asm-generic/numa.h b/include/asm-generic/numa.h
new file mode 100644
index 000000000000..1a3ad6d29833
--- /dev/null
+++ b/include/asm-generic/numa.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_GENERIC_NUMA_H
+#define __ASM_GENERIC_NUMA_H
+
+#ifdef CONFIG_NUMA
+
+#define NR_NODE_MEMBLKS		(MAX_NUMNODES * 2)
+
+int __node_distance(int from, int to);
+#define node_distance(a, b) __node_distance(a, b)
+
+extern nodemask_t numa_nodes_parsed __initdata;
+
+extern bool numa_off;
+
+/* Mappings between node number and cpus on that node. */
+extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
+void numa_clear_node(unsigned int cpu);
+
+#ifdef CONFIG_DEBUG_PER_CPU_MAPS
+const struct cpumask *cpumask_of_node(int node);
+#else
+/* Returns a pointer to the cpumask of CPUs on Node 'node'. */
+static inline const struct cpumask *cpumask_of_node(int node)
+{
+	if (node == NUMA_NO_NODE)
+		return cpu_all_mask;
+
+	return node_to_cpumask_map[node];
+}
+#endif
+
+void __init arch_numa_init(void);
+int __init numa_add_memblk(int nodeid, u64 start, u64 end);
+void __init numa_set_distance(int from, int to, int distance);
+void __init numa_free_distance(void);
+void __init early_map_cpu_to_node(unsigned int cpu, int nid);
+void numa_store_cpu_info(unsigned int cpu);
+void numa_add_cpu(unsigned int cpu);
+void numa_remove_cpu(unsigned int cpu);
+
+#else	/* CONFIG_NUMA */
+
+static inline void numa_store_cpu_info(unsigned int cpu) { }
+static inline void numa_add_cpu(unsigned int cpu) { }
+static inline void numa_remove_cpu(unsigned int cpu) { }
+static inline void arch_numa_init(void) { }
+static inline void early_map_cpu_to_node(unsigned int cpu, int nid) { }
+
+#endif	/* CONFIG_NUMA */
+
+#endif	/* __ASM_GENERIC_NUMA_H */
-- 
2.25.1