Re: [PATCH v1 3/5] drivers/base/memory: store mapping between MMOP_* and string in an array

[Wei Yang]

On Wed, Mar 11, 2020 at 01:30:24PM +0100, David Hildenbrand wrote:
>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.
>
>Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
>Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
>Cc: Michal Hocko <mhocko@xxxxxxxxxx>
>Cc: Oscar Salvador <osalvador@xxxxxxx>
>Cc: "Rafael J. Wysocki" <rafael@xxxxxxxxxx>
>Cc: Baoquan He <bhe@xxxxxxxxxx>
>Cc: Wei Yang <richard.weiyang@xxxxxxxxx>
>Signed-off-by: David Hildenbrand <david@xxxxxxxxxx>
>---
> 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);

In your following patch, you did the same conversion. Is it possible to merge
them into this one?

> 	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)
>-- 
>2.24.1

-- 
Wei Yang
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