UPSTREAM: usb: dwc3: omap: Don't set POWERPRESENT
[firefly-linux-kernel-4.4.55.git] / drivers / base / memory.c
index 86abbff912ecc0687e1b4ac93701af8cfcded1b5..25425d3f257536b291f27aa975bb8f164c0c437c 100644 (file)
@@ -16,7 +16,6 @@
 #include <linux/capability.h>
 #include <linux/device.h>
 #include <linux/memory.h>
-#include <linux/kobject.h>
 #include <linux/memory_hotplug.h>
 #include <linux/mm.h>
 #include <linux/mutex.h>
@@ -30,6 +29,8 @@ static DEFINE_MUTEX(mem_sysfs_mutex);
 
 #define MEMORY_CLASS_NAME      "memory"
 
+#define to_memory_block(dev) container_of(dev, struct memory_block, dev)
+
 static int sections_per_block;
 
 static inline int base_memory_block_id(int section_nr)
@@ -37,22 +38,27 @@ static inline int base_memory_block_id(int section_nr)
        return section_nr / sections_per_block;
 }
 
+static int memory_subsys_online(struct device *dev);
+static int memory_subsys_offline(struct device *dev);
+
 static struct bus_type memory_subsys = {
        .name = MEMORY_CLASS_NAME,
        .dev_name = MEMORY_CLASS_NAME,
+       .online = memory_subsys_online,
+       .offline = memory_subsys_offline,
 };
 
 static BLOCKING_NOTIFIER_HEAD(memory_chain);
 
 int register_memory_notifier(struct notifier_block *nb)
 {
-        return blocking_notifier_chain_register(&memory_chain, nb);
+       return blocking_notifier_chain_register(&memory_chain, nb);
 }
 EXPORT_SYMBOL(register_memory_notifier);
 
 void unregister_memory_notifier(struct notifier_block *nb)
 {
-        blocking_notifier_chain_unregister(&memory_chain, nb);
+       blocking_notifier_chain_unregister(&memory_chain, nb);
 }
 EXPORT_SYMBOL(unregister_memory_notifier);
 
@@ -72,27 +78,11 @@ EXPORT_SYMBOL(unregister_memory_isolate_notifier);
 
 static void memory_block_release(struct device *dev)
 {
-       struct memory_block *mem = container_of(dev, struct memory_block, dev);
+       struct memory_block *mem = to_memory_block(dev);
 
        kfree(mem);
 }
 
-/*
- * register_memory - Setup a sysfs device for a memory block
- */
-static
-int register_memory(struct memory_block *memory)
-{
-       int error;
-
-       memory->dev.bus = &memory_subsys;
-       memory->dev.id = memory->start_section_nr / sections_per_block;
-       memory->dev.release = memory_block_release;
-
-       error = device_register(&memory->dev);
-       return error;
-}
-
 unsigned long __weak memory_block_size_bytes(void)
 {
        return MIN_MEMORY_BLOCK_SIZE;
@@ -121,25 +111,13 @@ static unsigned long get_memory_block_size(void)
 static ssize_t show_mem_start_phys_index(struct device *dev,
                        struct device_attribute *attr, char *buf)
 {
-       struct memory_block *mem =
-               container_of(dev, struct memory_block, dev);
+       struct memory_block *mem = to_memory_block(dev);
        unsigned long phys_index;
 
        phys_index = mem->start_section_nr / sections_per_block;
        return sprintf(buf, "%08lx\n", phys_index);
 }
 
-static ssize_t show_mem_end_phys_index(struct device *dev,
-                       struct device_attribute *attr, char *buf)
-{
-       struct memory_block *mem =
-               container_of(dev, struct memory_block, dev);
-       unsigned long phys_index;
-
-       phys_index = mem->end_section_nr / sections_per_block;
-       return sprintf(buf, "%08lx\n", phys_index);
-}
-
 /*
  * Show whether the section of memory is likely to be hot-removable
  */
@@ -148,8 +126,7 @@ static ssize_t show_mem_removable(struct device *dev,
 {
        unsigned long i, pfn;
        int ret = 1;
-       struct memory_block *mem =
-               container_of(dev, struct memory_block, dev);
+       struct memory_block *mem = to_memory_block(dev);
 
        for (i = 0; i < sections_per_block; i++) {
                if (!present_section_nr(mem->start_section_nr + i))
@@ -167,8 +144,7 @@ static ssize_t show_mem_removable(struct device *dev,
 static ssize_t show_mem_state(struct device *dev,
                        struct device_attribute *attr, char *buf)
 {
-       struct memory_block *mem =
-               container_of(dev, struct memory_block, dev);
+       struct memory_block *mem = to_memory_block(dev);
        ssize_t len = 0;
 
        /*
@@ -176,20 +152,20 @@ static ssize_t show_mem_state(struct device *dev,
         * so that they're not open-coded
         */
        switch (mem->state) {
-               case MEM_ONLINE:
-                       len = sprintf(buf, "online\n");
-                       break;
-               case MEM_OFFLINE:
-                       len = sprintf(buf, "offline\n");
-                       break;
-               case MEM_GOING_OFFLINE:
-                       len = sprintf(buf, "going-offline\n");
-                       break;
-               default:
-                       len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
-                                       mem->state);
-                       WARN_ON(1);
-                       break;
+       case MEM_ONLINE:
+               len = sprintf(buf, "online\n");
+               break;
+       case MEM_OFFLINE:
+               len = sprintf(buf, "offline\n");
+               break;
+       case MEM_GOING_OFFLINE:
+               len = sprintf(buf, "going-offline\n");
+               break;
+       default:
+               len = sprintf(buf, "ERROR-UNKNOWN-%ld\n",
+                               mem->state);
+               WARN_ON(1);
+               break;
        }
 
        return len;
@@ -243,6 +219,7 @@ static bool pages_correctly_reserved(unsigned long start_pfn)
 /*
  * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is
  * OK to have direct references to sparsemem variables in here.
+ * Must already be protected by mem_hotplug_begin().
  */
 static int
 memory_block_action(unsigned long phys_index, unsigned long action, int online_type)
@@ -252,98 +229,137 @@ memory_block_action(unsigned long phys_index, unsigned long action, int online_t
        struct page *first_page;
        int ret;
 
-       first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT);
-       start_pfn = page_to_pfn(first_page);
+       start_pfn = section_nr_to_pfn(phys_index);
+       first_page = pfn_to_page(start_pfn);
 
        switch (action) {
-               case MEM_ONLINE:
-                       if (!pages_correctly_reserved(start_pfn))
-                               return -EBUSY;
-
-                       ret = online_pages(start_pfn, nr_pages, online_type);
-                       break;
-               case MEM_OFFLINE:
-                       ret = offline_pages(start_pfn, nr_pages);
-                       break;
-               default:
-                       WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
-                            "%ld\n", __func__, phys_index, action, action);
-                       ret = -EINVAL;
+       case MEM_ONLINE:
+               if (!pages_correctly_reserved(start_pfn))
+                       return -EBUSY;
+
+               ret = online_pages(start_pfn, nr_pages, online_type);
+               break;
+       case MEM_OFFLINE:
+               ret = offline_pages(start_pfn, nr_pages);
+               break;
+       default:
+               WARN(1, KERN_WARNING "%s(%ld, %ld) unknown action: "
+                    "%ld\n", __func__, phys_index, action, action);
+               ret = -EINVAL;
        }
 
        return ret;
 }
 
-static int __memory_block_change_state(struct memory_block *mem,
-               unsigned long to_state, unsigned long from_state_req,
-               int online_type)
+static int memory_block_change_state(struct memory_block *mem,
+               unsigned long to_state, unsigned long from_state_req)
 {
        int ret = 0;
 
-       if (mem->state != from_state_req) {
-               ret = -EINVAL;
-               goto out;
-       }
+       if (mem->state != from_state_req)
+               return -EINVAL;
 
        if (to_state == MEM_OFFLINE)
                mem->state = MEM_GOING_OFFLINE;
 
-       ret = memory_block_action(mem->start_section_nr, to_state, online_type);
+       ret = memory_block_action(mem->start_section_nr, to_state,
+                               mem->online_type);
 
-       if (ret) {
-               mem->state = from_state_req;
-               goto out;
-       }
+       mem->state = ret ? from_state_req : to_state;
 
-       mem->state = to_state;
-       switch (mem->state) {
-       case MEM_OFFLINE:
-               kobject_uevent(&mem->dev.kobj, KOBJ_OFFLINE);
-               break;
-       case MEM_ONLINE:
-               kobject_uevent(&mem->dev.kobj, KOBJ_ONLINE);
-               break;
-       default:
-               break;
-       }
-out:
        return ret;
 }
 
-static int memory_block_change_state(struct memory_block *mem,
-               unsigned long to_state, unsigned long from_state_req,
-               int online_type)
+/* The device lock serializes operations on memory_subsys_[online|offline] */
+static int memory_subsys_online(struct device *dev)
 {
+       struct memory_block *mem = to_memory_block(dev);
        int ret;
 
-       mutex_lock(&mem->state_mutex);
-       ret = __memory_block_change_state(mem, to_state, from_state_req,
-                                         online_type);
-       mutex_unlock(&mem->state_mutex);
+       if (mem->state == MEM_ONLINE)
+               return 0;
+
+       /*
+        * If we are called from store_mem_state(), online_type will be
+        * set >= 0 Otherwise we were called from the device online
+        * attribute and need to set the online_type.
+        */
+       if (mem->online_type < 0)
+               mem->online_type = MMOP_ONLINE_KEEP;
+
+       /* Already under protection of mem_hotplug_begin() */
+       ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
+
+       /* clear online_type */
+       mem->online_type = -1;
 
        return ret;
 }
+
+static int memory_subsys_offline(struct device *dev)
+{
+       struct memory_block *mem = to_memory_block(dev);
+
+       if (mem->state == MEM_OFFLINE)
+               return 0;
+
+       /* Can't offline block with non-present sections */
+       if (mem->section_count != sections_per_block)
+               return -EINVAL;
+
+       return memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE);
+}
+
 static ssize_t
 store_mem_state(struct device *dev,
                struct device_attribute *attr, const char *buf, size_t count)
 {
-       struct memory_block *mem;
-       int ret = -EINVAL;
-
-       mem = container_of(dev, struct memory_block, dev);
-
-       if (!strncmp(buf, "online_kernel", min_t(int, count, 13)))
-               ret = memory_block_change_state(mem, MEM_ONLINE,
-                                               MEM_OFFLINE, ONLINE_KERNEL);
-       else if (!strncmp(buf, "online_movable", min_t(int, count, 14)))
-               ret = memory_block_change_state(mem, MEM_ONLINE,
-                                               MEM_OFFLINE, ONLINE_MOVABLE);
-       else if (!strncmp(buf, "online", min_t(int, count, 6)))
-               ret = memory_block_change_state(mem, MEM_ONLINE,
-                                               MEM_OFFLINE, ONLINE_KEEP);
-       else if(!strncmp(buf, "offline", min_t(int, count, 7)))
-               ret = memory_block_change_state(mem, MEM_OFFLINE,
-                                               MEM_ONLINE, -1);
+       struct memory_block *mem = to_memory_block(dev);
+       int ret, online_type;
+
+       ret = lock_device_hotplug_sysfs();
+       if (ret)
+               return ret;
+
+       if (sysfs_streq(buf, "online_kernel"))
+               online_type = MMOP_ONLINE_KERNEL;
+       else if (sysfs_streq(buf, "online_movable"))
+               online_type = MMOP_ONLINE_MOVABLE;
+       else if (sysfs_streq(buf, "online"))
+               online_type = MMOP_ONLINE_KEEP;
+       else if (sysfs_streq(buf, "offline"))
+               online_type = MMOP_OFFLINE;
+       else {
+               ret = -EINVAL;
+               goto err;
+       }
+
+       /*
+        * Memory hotplug needs to hold mem_hotplug_begin() for probe to find
+        * the correct memory block to online before doing device_online(dev),
+        * which will take dev->mutex.  Take the lock early to prevent an
+        * inversion, memory_subsys_online() callbacks will be implemented by
+        * assuming it's already protected.
+        */
+       mem_hotplug_begin();
+
+       switch (online_type) {
+       case MMOP_ONLINE_KERNEL:
+       case MMOP_ONLINE_MOVABLE:
+       case MMOP_ONLINE_KEEP:
+               mem->online_type = online_type;
+               ret = device_online(&mem->dev);
+               break;
+       case MMOP_OFFLINE:
+               ret = device_offline(&mem->dev);
+               break;
+       default:
+               ret = -EINVAL; /* should never happen */
+       }
+
+       mem_hotplug_done();
+err:
+       unlock_device_hotplug();
 
        if (ret)
                return ret;
@@ -362,22 +378,54 @@ store_mem_state(struct device *dev,
 static ssize_t show_phys_device(struct device *dev,
                                struct device_attribute *attr, char *buf)
 {
-       struct memory_block *mem =
-               container_of(dev, struct memory_block, dev);
+       struct memory_block *mem = to_memory_block(dev);
        return sprintf(buf, "%d\n", mem->phys_device);
 }
 
+#ifdef CONFIG_MEMORY_HOTREMOVE
+static ssize_t show_valid_zones(struct device *dev,
+                               struct device_attribute *attr, char *buf)
+{
+       struct memory_block *mem = to_memory_block(dev);
+       unsigned long start_pfn, end_pfn;
+       unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block;
+       struct page *first_page;
+       struct zone *zone;
+
+       start_pfn = section_nr_to_pfn(mem->start_section_nr);
+       end_pfn = start_pfn + nr_pages;
+       first_page = pfn_to_page(start_pfn);
+
+       /* The block contains more than one zone can not be offlined. */
+       if (!test_pages_in_a_zone(start_pfn, end_pfn))
+               return sprintf(buf, "none\n");
+
+       zone = page_zone(first_page);
+
+       if (zone_idx(zone) == ZONE_MOVABLE - 1) {
+               /*The mem block is the last memoryblock of this zone.*/
+               if (end_pfn == zone_end_pfn(zone))
+                       return sprintf(buf, "%s %s\n",
+                                       zone->name, (zone + 1)->name);
+       }
+
+       if (zone_idx(zone) == ZONE_MOVABLE) {
+               /*The mem block is the first memoryblock of ZONE_MOVABLE.*/
+               if (start_pfn == zone->zone_start_pfn)
+                       return sprintf(buf, "%s %s\n",
+                                       zone->name, (zone - 1)->name);
+       }
+
+       return sprintf(buf, "%s\n", zone->name);
+}
+static DEVICE_ATTR(valid_zones, 0444, show_valid_zones, NULL);
+#endif
+
 static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL);
-static DEVICE_ATTR(end_phys_index, 0444, show_mem_end_phys_index, NULL);
 static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state);
 static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL);
 static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL);
 
-#define mem_create_simple_file(mem, attr_name) \
-       device_create_file(&mem->dev, &dev_attr_##attr_name)
-#define mem_remove_simple_file(mem, attr_name) \
-       device_remove_file(&mem->dev, &dev_attr_##attr_name)
-
 /*
  * Block size attribute stuff
  */
@@ -390,12 +438,6 @@ print_block_size(struct device *dev, struct device_attribute *attr,
 
 static DEVICE_ATTR(block_size_bytes, 0444, print_block_size, NULL);
 
-static int block_size_init(void)
-{
-       return device_create_file(memory_subsys.dev_root,
-                                 &dev_attr_block_size_bytes);
-}
-
 /*
  * Some architectures will have custom drivers to do this, and
  * will not need to do it from userspace.  The fake hot-add code
@@ -412,7 +454,9 @@ memory_probe_store(struct device *dev, struct device_attribute *attr,
        int i, ret;
        unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block;
 
-       phys_addr = simple_strtoull(buf, NULL, 0);
+       ret = kstrtoull(buf, 0, &phys_addr);
+       if (ret)
+               return ret;
 
        if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
                return -EINVAL;
@@ -431,17 +475,8 @@ memory_probe_store(struct device *dev, struct device_attribute *attr,
 out:
        return ret;
 }
-static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
 
-static int memory_probe_init(void)
-{
-       return device_create_file(memory_subsys.dev_root, &dev_attr_probe);
-}
-#else
-static inline int memory_probe_init(void)
-{
-       return 0;
-}
+static DEVICE_ATTR(probe, S_IWUSR, NULL, memory_probe_store);
 #endif
 
 #ifdef CONFIG_MEMORY_FAILURE
@@ -459,7 +494,7 @@ store_soft_offline_page(struct device *dev,
        u64 pfn;
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
-       if (strict_strtoull(buf, 0, &pfn) < 0)
+       if (kstrtoull(buf, 0, &pfn) < 0)
                return -EINVAL;
        pfn >>= PAGE_SHIFT;
        if (!pfn_valid(pfn))
@@ -478,7 +513,7 @@ store_hard_offline_page(struct device *dev,
        u64 pfn;
        if (!capable(CAP_SYS_ADMIN))
                return -EPERM;
-       if (strict_strtoull(buf, 0, &pfn) < 0)
+       if (kstrtoull(buf, 0, &pfn) < 0)
                return -EINVAL;
        pfn >>= PAGE_SHIFT;
        ret = memory_failure(pfn, 0, 0);
@@ -487,23 +522,6 @@ store_hard_offline_page(struct device *dev,
 
 static DEVICE_ATTR(soft_offline_page, S_IWUSR, NULL, store_soft_offline_page);
 static DEVICE_ATTR(hard_offline_page, S_IWUSR, NULL, store_hard_offline_page);
-
-static __init int memory_fail_init(void)
-{
-       int err;
-
-       err = device_create_file(memory_subsys.dev_root,
-                               &dev_attr_soft_offline_page);
-       if (!err)
-               err = device_create_file(memory_subsys.dev_root,
-                               &dev_attr_hard_offline_page);
-       return err;
-}
-#else
-static inline int memory_fail_init(void)
-{
-       return 0;
-}
 #endif
 
 /*
@@ -532,7 +550,7 @@ struct memory_block *find_memory_block_hinted(struct mem_section *section,
                put_device(&hint->dev);
        if (!dev)
                return NULL;
-       return container_of(dev, struct memory_block, dev);
+       return to_memory_block(dev);
 }
 
 /*
@@ -548,6 +566,41 @@ struct memory_block *find_memory_block(struct mem_section *section)
        return find_memory_block_hinted(section, NULL);
 }
 
+static struct attribute *memory_memblk_attrs[] = {
+       &dev_attr_phys_index.attr,
+       &dev_attr_state.attr,
+       &dev_attr_phys_device.attr,
+       &dev_attr_removable.attr,
+#ifdef CONFIG_MEMORY_HOTREMOVE
+       &dev_attr_valid_zones.attr,
+#endif
+       NULL
+};
+
+static struct attribute_group memory_memblk_attr_group = {
+       .attrs = memory_memblk_attrs,
+};
+
+static const struct attribute_group *memory_memblk_attr_groups[] = {
+       &memory_memblk_attr_group,
+       NULL,
+};
+
+/*
+ * register_memory - Setup a sysfs device for a memory block
+ */
+static
+int register_memory(struct memory_block *memory)
+{
+       memory->dev.bus = &memory_subsys;
+       memory->dev.id = memory->start_section_nr / sections_per_block;
+       memory->dev.release = memory_block_release;
+       memory->dev.groups = memory_memblk_attr_groups;
+       memory->dev.offline = memory->state == MEM_OFFLINE;
+
+       return device_register(&memory->dev);
+}
+
 static int init_memory_block(struct memory_block **memory,
                             struct mem_section *section, unsigned long state)
 {
@@ -566,75 +619,66 @@ static int init_memory_block(struct memory_block **memory,
        mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
        mem->state = state;
        mem->section_count++;
-       mutex_init(&mem->state_mutex);
        start_pfn = section_nr_to_pfn(mem->start_section_nr);
        mem->phys_device = arch_get_memory_phys_device(start_pfn);
 
        ret = register_memory(mem);
-       if (!ret)
-               ret = mem_create_simple_file(mem, phys_index);
-       if (!ret)
-               ret = mem_create_simple_file(mem, end_phys_index);
-       if (!ret)
-               ret = mem_create_simple_file(mem, state);
-       if (!ret)
-               ret = mem_create_simple_file(mem, phys_device);
-       if (!ret)
-               ret = mem_create_simple_file(mem, removable);
 
        *memory = mem;
        return ret;
 }
 
-static int add_memory_section(int nid, struct mem_section *section,
-                       struct memory_block **mem_p,
-                       unsigned long state, enum mem_add_context context)
+static int add_memory_block(int base_section_nr)
 {
-       struct memory_block *mem = NULL;
-       int scn_nr = __section_nr(section);
-       int ret = 0;
-
-       mutex_lock(&mem_sysfs_mutex);
-
-       if (context == BOOT) {
-               /* same memory block ? */
-               if (mem_p && *mem_p)
-                       if (scn_nr >= (*mem_p)->start_section_nr &&
-                           scn_nr <= (*mem_p)->end_section_nr) {
-                               mem = *mem_p;
-                               kobject_get(&mem->dev.kobj);
-                       }
-       } else
-               mem = find_memory_block(section);
-
-       if (mem) {
-               mem->section_count++;
-               kobject_put(&mem->dev.kobj);
-       } else {
-               ret = init_memory_block(&mem, section, state);
-               /* store memory_block pointer for next loop */
-               if (!ret && context == BOOT)
-                       if (mem_p)
-                               *mem_p = mem;
-       }
+       struct memory_block *mem;
+       int i, ret, section_count = 0, section_nr;
 
-       if (!ret) {
-               if (context == HOTPLUG &&
-                   mem->section_count == sections_per_block)
-                       ret = register_mem_sect_under_node(mem, nid);
+       for (i = base_section_nr;
+            (i < base_section_nr + sections_per_block) && i < NR_MEM_SECTIONS;
+            i++) {
+               if (!present_section_nr(i))
+                       continue;
+               if (section_count == 0)
+                       section_nr = i;
+               section_count++;
        }
 
-       mutex_unlock(&mem_sysfs_mutex);
-       return ret;
+       if (section_count == 0)
+               return 0;
+       ret = init_memory_block(&mem, __nr_to_section(section_nr), MEM_ONLINE);
+       if (ret)
+               return ret;
+       mem->section_count = section_count;
+       return 0;
 }
 
+
 /*
  * need an interface for the VM to add new memory regions,
  * but without onlining it.
  */
 int register_new_memory(int nid, struct mem_section *section)
 {
-       return add_memory_section(nid, section, NULL, MEM_OFFLINE, HOTPLUG);
+       int ret = 0;
+       struct memory_block *mem;
+
+       mutex_lock(&mem_sysfs_mutex);
+
+       mem = find_memory_block(section);
+       if (mem) {
+               mem->section_count++;
+               put_device(&mem->dev);
+       } else {
+               ret = init_memory_block(&mem, section, MEM_OFFLINE);
+               if (ret)
+                       goto out;
+       }
+
+       if (mem->section_count == sections_per_block)
+               ret = register_mem_sect_under_node(mem, nid);
+out:
+       mutex_unlock(&mem_sysfs_mutex);
+       return ret;
 }
 
 #ifdef CONFIG_MEMORY_HOTREMOVE
@@ -644,7 +688,7 @@ unregister_memory(struct memory_block *memory)
        BUG_ON(memory->dev.bus != &memory_subsys);
 
        /* drop the ref. we got in remove_memory_block() */
-       kobject_put(&memory->dev.kobj);
+       put_device(&memory->dev);
        device_unregister(&memory->dev);
 }
 
@@ -658,15 +702,10 @@ static int remove_memory_block(unsigned long node_id,
        unregister_mem_sect_under_nodes(mem, __section_nr(section));
 
        mem->section_count--;
-       if (mem->section_count == 0) {
-               mem_remove_simple_file(mem, phys_index);
-               mem_remove_simple_file(mem, end_phys_index);
-               mem_remove_simple_file(mem, state);
-               mem_remove_simple_file(mem, phys_device);
-               mem_remove_simple_file(mem, removable);
+       if (mem->section_count == 0)
                unregister_memory(mem);
-       else
-               kobject_put(&mem->dev.kobj);
+       else
+               put_device(&mem->dev);
 
        mutex_unlock(&mem_sysfs_mutex);
        return 0;
@@ -681,27 +720,35 @@ int unregister_memory_section(struct mem_section *section)
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
-/*
- * offline one memory block. If the memory block has been offlined, do nothing.
- */
-int offline_memory_block(struct memory_block *mem)
-{
-       int ret = 0;
-
-       mutex_lock(&mem->state_mutex);
-       if (mem->state != MEM_OFFLINE)
-               ret = __memory_block_change_state(mem, MEM_OFFLINE, MEM_ONLINE, -1);
-       mutex_unlock(&mem->state_mutex);
-
-       return ret;
-}
-
 /* return true if the memory block is offlined, otherwise, return false */
 bool is_memblock_offlined(struct memory_block *mem)
 {
        return mem->state == MEM_OFFLINE;
 }
 
+static struct attribute *memory_root_attrs[] = {
+#ifdef CONFIG_ARCH_MEMORY_PROBE
+       &dev_attr_probe.attr,
+#endif
+
+#ifdef CONFIG_MEMORY_FAILURE
+       &dev_attr_soft_offline_page.attr,
+       &dev_attr_hard_offline_page.attr,
+#endif
+
+       &dev_attr_block_size_bytes.attr,
+       NULL
+};
+
+static struct attribute_group memory_root_attr_group = {
+       .attrs = memory_root_attrs,
+};
+
+static const struct attribute_group *memory_root_attr_groups[] = {
+       &memory_root_attr_group,
+       NULL,
+};
+
 /*
  * Initialize the sysfs support for memory devices...
  */
@@ -711,9 +758,8 @@ int __init memory_dev_init(void)
        int ret;
        int err;
        unsigned long block_sz;
-       struct memory_block *mem = NULL;
 
-       ret = subsys_system_register(&memory_subsys, NULL);
+       ret = subsys_system_register(&memory_subsys, memory_root_attr_groups);
        if (ret)
                goto out;
 
@@ -724,27 +770,14 @@ int __init memory_dev_init(void)
         * Create entries for memory sections that were found
         * during boot and have been initialized
         */
-       for (i = 0; i < NR_MEM_SECTIONS; i++) {
-               if (!present_section_nr(i))
-                       continue;
-               /* don't need to reuse memory_block if only one per block */
-               err = add_memory_section(0, __nr_to_section(i),
-                                (sections_per_block == 1) ? NULL : &mem,
-                                        MEM_ONLINE,
-                                        BOOT);
+       mutex_lock(&mem_sysfs_mutex);
+       for (i = 0; i < NR_MEM_SECTIONS; i += sections_per_block) {
+               err = add_memory_block(i);
                if (!ret)
                        ret = err;
        }
+       mutex_unlock(&mem_sysfs_mutex);
 
-       err = memory_probe_init();
-       if (!ret)
-               ret = err;
-       err = memory_fail_init();
-       if (!ret)
-               ret = err;
-       err = block_size_init();
-       if (!ret)
-               ret = err;
 out:
        if (ret)
                printk(KERN_ERR "%s() failed: %d\n", __func__, ret);