drivers/base/memory: store mapping between MMOP_* and string in an array

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.

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/20200317104942.11178-4-david@redhat.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index f65f3d5..1c90bdf 100644 (file)
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -27,6 +27,24 @@
 
 #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;
@@ -228,26 +246,17 @@ 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:
@@ -263,7 +272,6 @@ static ssize_t state_store(struct device *dev, struct device_attribute *attr,
                ret = -EINVAL; /* should never happen */
        }
 
-err:
        unlock_device_hotplug();
 
        if (ret < 0)