From 2a0023a0ee0d7401b88211dceb439bc32b8f3cae Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Wed, 9 Feb 2022 15:36:10 +0800
Subject: [PATCH] drivers/base/memory: map MMOP_OFFLINE to 0

mainline inclusion
from linux-5.7-rc1
commit efc978ad0e05ed6401c7854811750bf55b67f4b9
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S
CVE: NA

--------------------------------

Historically, we used the value -1.  Just treat 0 as the special case now.
Clarify a comment (which was wrong, when we come via device_online() the
first time, the online_type would have been 0 / MEM_ONLINE).  The default
is now always MMOP_OFFLINE.  This removes the last user of the manual
"-1", which didn't use the enum value.

This is a preparation to use the online_type as an array index.

Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Baoquan He <bhe@redhat.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Yumei Huang <yuhuang@redhat.com>
Link: http://lkml.kernel.org/r/20200317104942.11178-3-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
---
 drivers/base/memory.c          | 11 ++++-------
 include/linux/memory_hotplug.h |  2 +-
 2 files changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index 74d9bf9dddaa..5dff2c0d56b9 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -293,17 +293,14 @@ static int memory_subsys_online(struct device *dev)
 		return 0;
 
 	/*
-	 * If we are called from state_store(), online_type will be
-	 * set >= 0 Otherwise we were called from the device online
-	 * attribute and need to set the online_type.
+	 * When called via device_online() without configuring the online_type,
+	 * we want to default to MMOP_ONLINE.
 	 */
-	if (mem->online_type < 0)
+	if (mem->online_type == MMOP_OFFLINE)
 		mem->online_type = MMOP_ONLINE;
 
 	ret = memory_block_change_state(mem, MEM_ONLINE, MEM_OFFLINE);
-
-	/* clear online_type */
-	mem->online_type = -1;
+	mem->online_type = MMOP_OFFLINE;
 
 	return ret;
 }
diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 09a05938576a..dfb5d5b6f106 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -48,7 +48,7 @@ enum {
 /* Types for control the zone type of onlined and offlined memory */
 enum {
 	/* Offline the memory. */
-	MMOP_OFFLINE = -1,
+	MMOP_OFFLINE = 0,
 	/* Online the memory. Zone depends, see default_zone_for_pfn(). */
 	MMOP_ONLINE,
 	/* Online the memory to ZONE_NORMAL. */
-- 
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