1 files changed, 55 insertions, 14 deletions

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 25425d3f2575..f46dba8b7092 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -251,7 +251,7 @@ memory_block_action(unsigned long phys_index, unsigned long action, int online_t
 	return ret;
 }
 
-static int memory_block_change_state(struct memory_block *mem,
+int memory_block_change_state(struct memory_block *mem,
 		unsigned long to_state, unsigned long from_state_req)
 {
 	int ret = 0;
@@ -439,6 +439,37 @@ print_block_size(struct device *dev, struct device_attribute *attr,
 static DEVICE_ATTR(block_size_bytes, 0444, print_block_size, NULL);
 
 /*
+ * Memory auto online policy.
+ */
+
+static ssize_t
+show_auto_online_blocks(struct device *dev, struct device_attribute *attr,
+			char *buf)
+{
+	if (memhp_auto_online)
+		return sprintf(buf, "online\n");
+	else
+		return sprintf(buf, "offline\n");
+}
+
+static ssize_t
+store_auto_online_blocks(struct device *dev, struct device_attribute *attr,
+			 const char *buf, size_t count)
+{
+	if (sysfs_streq(buf, "online"))
+		memhp_auto_online = true;
+	else if (sysfs_streq(buf, "offline"))
+		memhp_auto_online = false;
+	else
+		return -EINVAL;
+
+	return count;
+}
+
+static DEVICE_ATTR(auto_online_blocks, 0644, show_auto_online_blocks,
+		   store_auto_online_blocks);
+
+/*
  * Some architectures will have custom drivers to do this, and
  * will not need to do it from userspace.  The fake hot-add code
  * as well as ppc64 will do all of their discovery in userspace
@@ -450,8 +481,7 @@ memory_probe_store(struct device *dev, struct device_attribute *attr,
 		   const char *buf, size_t count)
 {
 	u64 phys_addr;
-	int nid;
-	int i, ret;
+	int nid, ret;
 	unsigned long pages_per_block = PAGES_PER_SECTION * sections_per_block;
 
 	ret = kstrtoull(buf, 0, &phys_addr);
@@ -461,15 +491,12 @@ memory_probe_store(struct device *dev, struct device_attribute *attr,
 	if (phys_addr & ((pages_per_block << PAGE_SHIFT) - 1))
 		return -EINVAL;
 
-	for (i = 0; i < sections_per_block; i++) {
-		nid = memory_add_physaddr_to_nid(phys_addr);
-		ret = add_memory(nid, phys_addr,
-				 PAGES_PER_SECTION << PAGE_SHIFT);
-		if (ret)
-			goto out;
+	nid = memory_add_physaddr_to_nid(phys_addr);
+	ret = add_memory(nid, phys_addr,
+			 MIN_MEMORY_BLOCK_SIZE * sections_per_block);
 
-		phys_addr += MIN_MEMORY_BLOCK_SIZE;
-	}
+	if (ret)
+		goto out;
 
 	ret = count;
 out:
@@ -618,7 +645,6 @@ static int init_memory_block(struct memory_block **memory,
 			base_memory_block_id(scn_nr) * sections_per_block;
 	mem->end_section_nr = mem->start_section_nr + sections_per_block - 1;
 	mem->state = state;
-	mem->section_count++;
 	start_pfn = section_nr_to_pfn(mem->start_section_nr);
 	mem->phys_device = arch_get_memory_phys_device(start_pfn);
 
@@ -652,6 +678,13 @@ static int add_memory_block(int base_section_nr)
 	return 0;
 }
 
+static bool is_zone_device_section(struct mem_section *ms)
+{
+	struct page *page;
+
+	page = sparse_decode_mem_map(ms->section_mem_map, __section_nr(ms));
+	return is_zone_device_page(page);
+}
 
 /*
  * need an interface for the VM to add new memory regions,
@@ -662,6 +695,9 @@ int register_new_memory(int nid, struct mem_section *section)
 	int ret = 0;
 	struct memory_block *mem;
 
+	if (is_zone_device_section(section))
+		return 0;
+
 	mutex_lock(&mem_sysfs_mutex);
 
 	mem = find_memory_block(section);
@@ -672,6 +708,7 @@ int register_new_memory(int nid, struct mem_section *section)
 		ret = init_memory_block(&mem, section, MEM_OFFLINE);
 		if (ret)
 			goto out;
+		mem->section_count++;
 	}
 
 	if (mem->section_count == sections_per_block)
@@ -692,11 +729,14 @@ unregister_memory(struct memory_block *memory)
 	device_unregister(&memory->dev);
 }
 
-static int remove_memory_block(unsigned long node_id,
+static int remove_memory_section(unsigned long node_id,
 			       struct mem_section *section, int phys_device)
 {
 	struct memory_block *mem;
 
+	if (is_zone_device_section(section))
+		return 0;
+
 	mutex_lock(&mem_sysfs_mutex);
 	mem = find_memory_block(section);
 	unregister_mem_sect_under_nodes(mem, __section_nr(section));
@@ -716,7 +756,7 @@ int unregister_memory_section(struct mem_section *section)
 	if (!present_section(section))
 		return -EINVAL;
 
-	return remove_memory_block(0, section, 0);
+	return remove_memory_section(0, section, 0);
 }
 #endif /* CONFIG_MEMORY_HOTREMOVE */
 
@@ -737,6 +777,7 @@ static struct attribute *memory_root_attrs[] = {
 #endif
 
 	&dev_attr_block_size_bytes.attr,
+	&dev_attr_auto_online_blocks.attr,
 	NULL
 };