[POWERPC] Fix ppc64's writing to struct file_operations

In preparation for marking file_operations as const.

Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 7 insertions, 4 deletions

diff --git a/arch/powerpc/kernel/lparcfg.c b/arch/powerpc/kernel/lparcfg.c
index 41c05dcd68f4..0de5a08cf9b0 100644
--- a/arch/powerpc/kernel/lparcfg.c
+++ b/arch/powerpc/kernel/lparcfg.c
@@ -439,6 +439,10 @@ static ssize_t lparcfg_write(struct file *file, const char __user * buf,
 
         ssize_t retval = -ENOMEM;
 
+        if (!firmware_has_feature(FW_FEATURE_SPLPAR) ||
+                        firmware_has_feature(FW_FEATURE_ISERIES))
+                return -EINVAL;
+
         kbuf = kmalloc(count, GFP_KERNEL);
         if (!kbuf)
                 goto out;
@@ -517,7 +521,7 @@ static int pseries_lparcfg_data(struct seq_file *m, void *v)
 static ssize_t lparcfg_write(struct file *file, const char __user * buf,
                              size_t count, loff_t * off)
 {
-        return count;
+        return -EINVAL;
 }
 
 #endif                          /* CONFIG_PPC_PSERIES */
@@ -570,6 +574,7 @@ static int lparcfg_open(struct inode *inode, struct file *file)
 struct file_operations lparcfg_fops = {
         .owner          = THIS_MODULE,
         .read           = seq_read,
+        .write          = lparcfg_write,
         .open           = lparcfg_open,
         .release        = single_release,
 };
@@ -581,10 +586,8 @@ int __init lparcfg_init(void)
 
         /* Allow writing if we have FW_FEATURE_SPLPAR */
         if (firmware_has_feature(FW_FEATURE_SPLPAR) &&
-                        !firmware_has_feature(FW_FEATURE_ISERIES)) {
-                lparcfg_fops.write = lparcfg_write;
+                        !firmware_has_feature(FW_FEATURE_ISERIES))
                 mode |= S_IWUSR;
-        }
 
         ent = create_proc_entry("ppc64/lparcfg", mode, NULL);
         if (ent) {