s390/cmm: split and simplify cmm pages proc handler

Split cmm_pages_handler into cmm_pages_handler and
cmm_timed_pages_handler, each handling separate proc entry.  And reuse
proc_doulongvec_minmax to simplify proc handlers. Min/max values are
optional and are omitted here.

Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/mm/cmm.c b/arch/s390/mm/cmm.c
index 6cf024eb2085d86e6a729e3cfa94e80a50f02a38..50d8d1c887a4ef6651a0a051e3598aa5a360543a 100644 (file)
--- a/arch/s390/mm/cmm.c
+++ b/arch/s390/mm/cmm.c
@@ -251,45 +251,42 @@ static int cmm_skip_blanks(char *cp, char **endp)
        return str != cp;
 }
 
-static struct ctl_table cmm_table[];
-
 static int cmm_pages_handler(struct ctl_table *ctl, int write,
                             void __user *buffer, size_t *lenp, loff_t *ppos)
 {
-       char buf[16], *p;
-       unsigned int len;
-       long nr;
+       long nr = cmm_get_pages();
+       struct ctl_table ctl_entry = {
+               .procname       = ctl->procname,
+               .data           = &nr,
+               .maxlen         = sizeof(long),
+       };
+       int rc;
 
-       if (!*lenp || (*ppos && !write)) {
-               *lenp = 0;
-               return 0;
-       }
+       rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
+       if (rc < 0 || !write)
+               return rc;
 
-       if (write) {
-               len = *lenp;
-               if (copy_from_user(buf, buffer,
-                                  len > sizeof(buf) ? sizeof(buf) : len))
-                       return -EFAULT;
-               buf[sizeof(buf) - 1] = '\0';
-               cmm_skip_blanks(buf, &p);
-               nr = simple_strtoul(p, &p, 0);
-               if (ctl == &cmm_table[0])
-                       cmm_set_pages(nr);
-               else
-                       cmm_add_timed_pages(nr);
-       } else {
-               if (ctl == &cmm_table[0])
-                       nr = cmm_get_pages();
-               else
-                       nr = cmm_get_timed_pages();
-               len = sprintf(buf, "%ld\n", nr);
-               if (len > *lenp)
-                       len = *lenp;
-               if (copy_to_user(buffer, buf, len))
-                       return -EFAULT;
-       }
-       *lenp = len;
-       *ppos += len;
+       cmm_set_pages(nr);
+       return 0;
+}
+
+static int cmm_timed_pages_handler(struct ctl_table *ctl, int write,
+                                  void __user *buffer, size_t *lenp,
+                                  loff_t *ppos)
+{
+       long nr = cmm_get_timed_pages();
+       struct ctl_table ctl_entry = {
+               .procname       = ctl->procname,
+               .data           = &nr,
+               .maxlen         = sizeof(long),
+       };
+       int rc;
+
+       rc = proc_doulongvec_minmax(&ctl_entry, write, buffer, lenp, ppos);
+       if (rc < 0 || !write)
+               return rc;
+
+       cmm_add_timed_pages(nr);
        return 0;
 }
 
@@ -338,7 +335,7 @@ static struct ctl_table cmm_table[] = {
        {
                .procname       = "cmm_timed_pages",
                .mode           = 0644,
-               .proc_handler   = cmm_pages_handler,
+               .proc_handler   = cmm_timed_pages_handler,
        },
        {
                .procname       = "cmm_timeout",