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 | 45 +++++++++++++++++++++++++++++++++------ drivers/base/memory.c | 39 ++++++++++++++++++++++++++++++++++ include/linux/memory.h | 5 ++++ include/linux/memory_hotplug.h | 5 ++++ mm/memory_hotplug.c | 22 +++++++++++++++++++ 5 files changed, 109 insertions(+), 7 deletions(-) diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c index 7873832..9d47458 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> @@ -310,25 +311,44 @@ 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); + if (result) + return result; + /* Power-off and eject the device */ result = acpi_memory_powerdown_device(mem_device); if (result) { @@ -477,12 +497,23 @@ 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 3113cd4..80cded7 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -1038,6 +1038,28 @@ 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 -- To unsubscribe from this list: send the line "unsubscribe linux-s390" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html