From: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
We should offline and remove memory when removing the memory device.
The memory device can be removed by 2 ways:
1. send eject request by SCI
2. echo 1 >/sys/bus/pci/devices/PNP0C80:XX/eject
In the 1st case, acpi_memory_disable_device() will be called. In the 2nd
case, acpi_memory_device_remove() will be called. acpi_memory_device_remove()
will also be called when we unbind the memory device from the driver
acpi_memhotplug. If the type is ACPI_BUS_REMOVAL_EJECT, it means
that the user wants to eject the memory device, and we should offline
and remove memory in acpi_memory_device_remove().
The function remove_memory() is not implemeted now. It only check whether
all memory has been offllined now.
CC: David Rientjes <rientjes@xxxxxxxxxx>
CC: Jiang Liu <liuj97@xxxxxxxxx>
CC: Len Brown <len.brown@xxxxxxxxx>
CC: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
CC: Paul Mackerras <paulus@xxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
Cc: Minchan Kim <minchan.kim@xxxxxxxxx>
CC: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
CC: KOSAKI Motohiro <kosaki.motohiro@xxxxxxxxxxxxxx>
Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx>
Signed-off-by: Wen Congyang <wency@xxxxxxxxxxxxxx>
---
drivers/acpi/acpi_memhotplug.c | 42 +++++++++++++++++++++++++++++++++------
drivers/base/memory.c | 39 +++++++++++++++++++++++++++++++++++++
include/linux/memory.h | 5 ++++
include/linux/memory_hotplug.h | 5 ++++
mm/memory_hotplug.c | 22 ++++++++++++++++++++
5 files changed, 106 insertions(+), 7 deletions(-)
diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c
index 293d718..ed37fc2 100644
--- a/drivers/acpi/acpi_memhotplug.c
+++ b/drivers/acpi/acpi_memhotplug.c
@@ -29,6 +29,7 @@
#include <linux/module.h>
#include <linux/init.h>
#include <linux/types.h>
+#include <linux/memory.h>
#include <linux/memory_hotplug.h>
#include <linux/slab.h>
#include <acpi/acpi_drivers.h>
@@ -310,26 +311,42 @@ static int acpi_memory_powerdown_device(struct acpi_memory_device *mem_device)
return 0;
}
-static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
+static int
+acpi_memory_device_remove_memory(struct acpi_memory_device *mem_device)
{
int result;
struct acpi_memory_info *info, *n;
+ int node = mem_device->nid;
-
- /*
- * Ask the VM to offline this memory range.
- * Note: Assume that this function returns zero on success
- */
list_for_each_entry_safe(info, n, &mem_device->res_list, list) {
if (info->enabled) {
result = offline_memory(info->start_addr, info->length);
if (result)
return result;
+
+ result = remove_memory(node, info->start_addr,
+ info->length);
+ if (result)
+ return result;
}
+
list_del(&info->list);
kfree(info);
}
+ return 0;
+}
+
+static int acpi_memory_disable_device(struct acpi_memory_device *mem_device)
+{
+ int result;
+
+ /*
+ * Ask the VM to offline this memory range.
+ * Note: Assume that this function returns zero on success
+ */
+ result = acpi_memory_device_remove_memory(mem_device);
+
/* Power-off and eject the device */
result = acpi_memory_powerdown_device(mem_device);
if (result) {
@@ -478,12 +495,23 @@ static int acpi_memory_device_add(struct acpi_device *device)
static int acpi_memory_device_remove(struct acpi_device *device, int type)
{
struct acpi_memory_device *mem_device = NULL;
-
+ int result;
if (!device || !acpi_driver_data(device))
return -EINVAL;
mem_device = acpi_driver_data(device);
+
+ if (type == ACPI_BUS_REMOVAL_EJECT) {
+ /*
+ * offline and remove memory only when the memory device is
+ * ejected.
+ */
+ result = acpi_memory_device_remove_memory(mem_device);
+ if (result)
+ return result;
+ }
+
kfree(mem_device);
return 0;
diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 86c8821..038be73 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -70,6 +70,45 @@ void unregister_memory_isolate_notifier(struct notifier_block *nb)
}
EXPORT_SYMBOL(unregister_memory_isolate_notifier);
+bool is_memblk_offline(unsigned long start, unsigned long size)
+{
+ struct memory_block *mem = NULL;
+ struct mem_section *section;
+ unsigned long start_pfn, end_pfn;
+ unsigned long pfn, section_nr;
+
+ start_pfn = PFN_DOWN(start);
+ end_pfn = PFN_UP(start + size);
+
+ for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
+ section_nr = pfn_to_section_nr(pfn);
+ if (!present_section_nr(section_nr))
+ continue;
+
+ section = __nr_to_section(section_nr);
+ /* same memblock? */
+ if (mem)
+ if ((section_nr >= mem->start_section_nr) &&
+ (section_nr <= mem->end_section_nr))
+ continue;
+
+ mem = find_memory_block_hinted(section, mem);
+ if (!mem)
+ continue;
+ if (mem->state == MEM_OFFLINE)
+ continue;
+
+ kobject_put(&mem->dev.kobj);
+ return false;
+ }
+
+ if (mem)
+ kobject_put(&mem->dev.kobj);
+
+ return true;
+}
+EXPORT_SYMBOL(is_memblk_offline);
+
/*
* register_memory - Setup a sysfs device for a memory block
*/
diff --git a/include/linux/memory.h b/include/linux/memory.h
index 1ac7f6e..7c66126 100644
--- a/include/linux/memory.h
+++ b/include/linux/memory.h
@@ -106,6 +106,10 @@ static inline int memory_isolate_notify(unsigned long val, void *v)
{
return 0;
}
+static inline bool is_memblk_offline(unsigned long start, unsigned long size)
+{
+ return false;
+}
#else
extern int register_memory_notifier(struct notifier_block *nb);
extern void unregister_memory_notifier(struct notifier_block *nb);
@@ -120,6 +124,7 @@ extern int memory_isolate_notify(unsigned long val, void *v);
extern struct memory_block *find_memory_block_hinted(struct mem_section *,
struct memory_block *);
extern struct memory_block *find_memory_block(struct mem_section *);
+extern bool is_memblk_offline(unsigned long start, unsigned long size);
#define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION<<PAGE_SHIFT)
enum mem_add_context { BOOT, HOTPLUG };
#endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 0b040bb..fd84ea9 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -222,6 +222,7 @@ static inline void unlock_memory_hotplug(void) {}
#ifdef CONFIG_MEMORY_HOTREMOVE
extern int is_mem_section_removable(unsigned long pfn, unsigned long nr_pages);
+extern int remove_memory(int nid, u64 start, u64 size);
#else
static inline int is_mem_section_removable(unsigned long pfn,
@@ -229,6 +230,10 @@ static inline int is_mem_section_removable(unsigned long pfn,
{
return 0;
}
+static inline int remove_memory(int nid, u64 start, u64 size)
+{
+ return -EBUSY;
+}
#endif /* CONFIG_MEMORY_HOTREMOVE */
extern int mem_online_node(int nid);
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 992454a..5af0a9f 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1034,6 +1034,28 @@ int offline_memory(u64 start, u64 size)
return 0;
}
+
+int remove_memory(int nid, u64 start, u64 size)
+{
+ int ret = -EBUSY;
+ lock_memory_hotplug();
+ /*
+ * The memory might become online by other task, even if you offine it.
+ * So we check whether the cpu has been onlined or not.
+ */
+ if (!is_memblk_offline(start, size)) {
+ pr_warn("memory removing [mem %#010llx-%#010llx] failed, "
+ "because the memmory range is online\n",
+ start, start + size);
+ ret = -EAGAIN;
+ }
+
+ unlock_memory_hotplug();
+ return ret;
+
+}
+EXPORT_SYMBOL_GPL(remove_memory);
+
#else
int offline_pages(u64 start, u64 size)
{
--
1.7.1
--
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