[PATCH v7 09/14] arm64/numa: support HAVE_SETUP_PER_CPU_AREA

Zhen Lei
2016-08-24T07:46:37Z

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 <thunder.leizhen@huawei.com>
---
arch/arm64/Kconfig | 8 ++++++++
arch/arm64/mm/numa.c | 55 ++++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 63 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index bc3f00f..2815af6 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -603,6 +603,14 @@ 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

diff --git a/arch/arm64/mm/numa.c b/arch/arm64/mm/numa.c
index 7b73808..5e44ad1 100644
--- a/arch/arm64/mm/numa.c
+++ b/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 +132,60 @@ 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)
+{
+ if (early_cpu_to_node(from) == early_cpu_to_node(to))
+ return LOCAL_DISTANCE;
+ else
+ return REMOTE_DISTANCE;
+}
+
+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
--
2.5.0