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From:   Gavin Shan <gshan@redhat.com>
To:     linux-mm@kvack.org
Cc:     linux-kernel@vger.kernel.org, david@redhat.com, osalvador@suse.de,
        gregkh@linuxfoundation.org, rafael@kernel.org, shan.gavin@gmail.com
Subject: [PATCH 2/2] drivers/base/memory: Use array to show memory block state
Date:   Fri, 20 Jan 2023 13:57:27 +0800
Message-Id: <20230120055727.355483-3-gshan@redhat.com>
In-Reply-To: <20230120055727.355483-1-gshan@redhat.com>
References: <20230120055727.355483-1-gshan@redhat.com>
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Use an array to show memory block state from '/sys/devices/system/
memory/memoryX/state', to simplify the code.

No functional change intended.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
 drivers/base/memory.c | 25 ++++++-------------------
 1 file changed, 6 insertions(+), 19 deletions(-)

diff --git a/drivers/base/memory.c b/drivers/base/memory.c
index b456ac213610..9474f25c452c 100644
--- a/drivers/base/memory.c
+++ b/drivers/base/memory.c
@@ -141,28 +141,15 @@ static ssize_t state_show(struct device *dev, struct device_attribute *attr,
 			  char *buf)
 {
 	struct memory_block *mem = to_memory_block(dev);
-	const char *output;
+	static const char *const mem_state_str[] = {
+		NULL, "online", "going-offline", NULL, "offline",
+	};
 
-	/*
-	 * We can probably put these states in a nice little array
-	 * so that they're not open-coded
-	 */
-	switch (mem->state) {
-	case MEM_ONLINE:
-		output = "online";
-		break;
-	case MEM_OFFLINE:
-		output = "offline";
-		break;
-	case MEM_GOING_OFFLINE:
-		output = "going-offline";
-		break;
-	default:
-		WARN_ON(1);
+	if (WARN_ON(mem->state >= ARRAY_SIZE(mem_state_str) ||
+		    !mem_state_str[mem->state]))
 		return sysfs_emit(buf, "ERROR-UNKNOWN-%ld\n", mem->state);
-	}
 
-	return sysfs_emit(buf, "%s\n", output);
+	return sysfs_emit(buf, "%s\n", mem_state_str[mem->state]);
 }
 
 int memory_notify(unsigned long val, void *v)
-- 
2.23.0