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

Michal Hocko
2020-03-16T15:20:59Z

On Wed 11-03-20 13:30:24, 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@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 <bhe@redhat.com>
> Cc: Wei Yang <richard.weiyang@gmail.com>
> Signed-off-by: David Hildenbrand <david@redhat.com>

Acked-by: Michal Hocko <mhocko@suse.com>

> ---
> 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)
> --
> 2.24.1

--
Michal Hocko
SUSE Labs