Let's use a simple array which we can reuse soon. While at it, move the
string->mmop conversion out of the device hotplug lock.

Reviewed-by: Wei Yang <redacted>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Baoquan He <redacted>
Cc: Wei Yang <redacted>
Signed-off-by: David Hildenbrand <redacted>
---
 drivers/base/memory.c | 38 +++++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index e7e77cafef80..8a7f29c0bf97 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c

@@ -28,6 +28,24 @@

 #define MEMORY_CLASS_NAME      "memory"

+static const char *const online_type_to_str[] = {
+       [MMOP_OFFLINE] = "offline",
+       [MMOP_ONLINE] = "online",
+       [MMOP_ONLINE_KERNEL] = "online_kernel",
+       [MMOP_ONLINE_MOVABLE] = "online_movable",
+};
+
+static int memhp_online_type_from_str(const char *str)
+{
+       int i;
+
+       for (i = 0; i < ARRAY_SIZE(online_type_to_str); i++) {
+               if (sysfs_streq(str, online_type_to_str[i]))
+                       return i;
+       }
+       return -EINVAL;
+}
+
 #define to_memory_block(dev) container_of(dev, struct memory_block, dev)

 static int sections_per_block;

@@ -236,26 +254,17 @@ static int memory_subsys_offline(struct device *dev)
 static ssize_t state_store(struct device *dev, struct device_attribute *attr,
                           const char *buf, size_t count)
 {
+       const int online_type = memhp_online_type_from_str(buf);
        struct memory_block *mem = to_memory_block(dev);
-       int ret, online_type;
+       int ret;
+
+       if (online_type < 0)
+               return -EINVAL;

        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;
-       else if (sysfs_streq(buf, "offline"))
-               online_type = MMOP_OFFLINE;
-       else {
-               ret = -EINVAL;
-               goto err;
-       }
-
        switch (online_type) {
        case MMOP_ONLINE_KERNEL:
        case MMOP_ONLINE_MOVABLE:

@@ -271,7 +280,6 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr,
                ret = -EINVAL; /* should never happen */
        }

-err:
        unlock_device_hotplug();

        if (ret < 0)
--