arm64/numa: support HAVE_SETUP_PER_CPU_AREA

To make each percpu area allocated from its local numa node. Without this
patch, all percpu areas will be allocated from the node which cpu0 belongs
to.

Signed-off-by: Zhen Lei <[email protected]>
Signed-off-by: Will Deacon <[email protected]>

Author: Zhen Lei

arch/arm64/Kconfig

@@ -600,6 +600,14 @@ config USE_PERCPU_NUMA_NODE_ID
 	def_bool y
 	depends on NUMA
 
+config HAVE_SETUP_PER_CPU_AREA
+	def_bool y
+	depends on NUMA
+
+config NEED_PER_CPU_EMBED_FIRST_CHUNK
+	def_bool y
+	depends on NUMA
+
 source kernel/Kconfig.preempt
 source kernel/Kconfig.hz
 

arch/arm64/mm/numa.c

@@ -26,6 +26,7 @@
 #include <linux/of.h>
 
 #include <asm/acpi.h>
+#include <asm/sections.h>
 
 struct pglist_data *node_data[MAX_NUMNODES] __read_mostly;
 EXPORT_SYMBOL(node_data);
@@ -131,6 +132,57 @@ void __init early_map_cpu_to_node(unsigned int cpu, int nid)
 	cpu_to_node_map[cpu] = nid;
 }
 
+#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
+unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
+EXPORT_SYMBOL(__per_cpu_offset);
+
+static int __init early_cpu_to_node(int cpu)
+{
+	return cpu_to_node_map[cpu];
+}
+
+static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
+{
+	return node_distance(from, to);
+}
+
+static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size,
+				       size_t align)
+{
+	int nid = early_cpu_to_node(cpu);
+
+	return  memblock_virt_alloc_try_nid(size, align,
+			__pa(MAX_DMA_ADDRESS), MEMBLOCK_ALLOC_ACCESSIBLE, nid);
+}
+
+static void __init pcpu_fc_free(void *ptr, size_t size)
+{
+	memblock_free_early(__pa(ptr), size);
+}
+
+void __init setup_per_cpu_areas(void)
+{
+	unsigned long delta;
+	unsigned int cpu;
+	int rc;
+
+	/*
+	 * Always reserve area for module percpu variables.  That's
+	 * what the legacy allocator did.
+	 */
+	rc = pcpu_embed_first_chunk(PERCPU_MODULE_RESERVE,
+				    PERCPU_DYNAMIC_RESERVE, PAGE_SIZE,
+				    pcpu_cpu_distance,
+				    pcpu_fc_alloc, pcpu_fc_free);
+	if (rc < 0)
+		panic("Failed to initialize percpu areas.");
+
+	delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
+	for_each_possible_cpu(cpu)
+		__per_cpu_offset[cpu] = delta + pcpu_unit_offsets[cpu];
+}
+#endif
+
 /**
  * numa_add_memblk - Set node id to memblk
  * @nid: NUMA node ID of the new memblk