[PATCH 1/5] arm64: memory-hotplug: Add MEMORY_HOTPLUG, MEMORY_HOTREMOVE, MEMORY_PROBE

Andrea Reale
2017-04-11T14:54:52Z

From: Scott Branden <scott.branden@broadcom.com>

Add memory-hotplug support for ARM64 platform.

This requires addition of
ARCH_ENABLE_MEMORY_HOTPLUG and ARCH_ENABLE_MEMORY_HOTREMOVE config options.

MEMORY_PROBE config option is added to support
/sys/devices/system/memory/probe functionality.

In addition architecture specific arch_add_memory and
arch_remove memory management functions are added.

Signed-off-by: Scott Branden <scott.branden@broadcom.com>
---
arch/arm64/Kconfig | 10 ++++++++++
arch/arm64/mm/init.c | 42 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 52 insertions(+)

diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3741859..d930f73 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -620,6 +620,12 @@ config HOTPLUG_CPU
Say Y here to experiment with turning CPUs off and on. CPUs
can be controlled through /sys/devices/system/cpu.

+config ARCH_ENABLE_MEMORY_HOTPLUG
+ def_bool y
+
+config ARCH_ENABLE_MEMORY_HOTREMOVE
+ def_bool y
+
# Common NUMA Features
config NUMA
bool "Numa Memory Allocation and Scheduler Support"
@@ -694,6 +700,10 @@ config ARCH_HAS_CACHE_LINE_SIZE

source "mm/Kconfig"

+config ARCH_MEMORY_PROBE
+ def_bool y
+ depends on MEMORY_HOTPLUG
+
config SECCOMP
bool "Enable seccomp to safely compute untrusted bytecode"
---help---
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index e19e065..4dcb8f7 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c
@@ -541,3 +541,45 @@ static int __init register_mem_limit_dumper(void)
return 0;
}
__initcall(register_mem_limit_dumper);
+
+#ifdef CONFIG_MEMORY_HOTPLUG
+int arch_add_memory(int nid, u64 start, u64 size, bool for_device)
+{
+ pg_data_t *pgdat;
+ struct zone *zone;
+ unsigned long start_pfn = start >> PAGE_SHIFT;
+ unsigned long nr_pages = size >> PAGE_SHIFT;
+ int ret;
+
+ pgdat = NODE_DATA(nid);
+
+ zone = pgdat->node_zones +
+ zone_for_memory(nid, start, size, ZONE_NORMAL, for_device);
+ ret = __add_pages(nid, zone, start_pfn, nr_pages);
+
+ if (ret)
+ pr_warn("%s: Problem encountered in __add_pages() ret=%d\n",
+ __func__, ret);
+
+ return ret;
+}
+
+#ifdef CONFIG_MEMORY_HOTREMOVE
+int arch_remove_memory(u64 start, u64 size)
+{
+ unsigned long start_pfn = start >> PAGE_SHIFT;
+ unsigned long nr_pages = size >> PAGE_SHIFT;
+ struct zone *zone;
+ int ret;
+
+ zone = page_zone(pfn_to_page(start_pfn));
+ ret = __remove_pages(zone, start_pfn, nr_pages);
+ if (ret)
+ pr_warn("%s: Problem encountered in __remove_pages() ret=%d\n",
+ __func__, ret);
+
+ return ret;
+}
+#endif
+#endif
+
--
1.9.1