[S390] s390/cio: use memory_read_from_buffer()

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Peter Oberparleiter <peter.oberparleiter@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/drivers/s390/cio/chp.c b/drivers/s390/cio/chp.c
index 8644c80..d58dc9f 100644 (file)
--- a/drivers/s390/cio/chp.c
+++ b/drivers/s390/cio/chp.c
@@ -143,21 +143,14 @@ static ssize_t chp_measurement_chars_read(struct kobject *kobj,
 {
        struct channel_path *chp;
        struct device *device;
-       unsigned int size;
 
        device = container_of(kobj, struct device, kobj);
        chp = to_channelpath(device);
        if (!chp->cmg_chars)
                return 0;
 
-       size = sizeof(struct cmg_chars);
-
-       if (off > size)
-               return 0;
-       if (off + count > size)
-               count = size - off;
-       memcpy(buf, chp->cmg_chars + off, count);
-       return count;
+       return memory_read_from_buffer(buf, count, &off,
+                               chp->cmg_chars, sizeof(struct cmg_chars));
 }
 
 static struct bin_attribute chp_measurement_chars_attr = {