x86/mtrr: Convert to use match_string() helper

The helper returns index of the matching string in an array.
Replace the open coded array lookup with match_string().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Luis R. Rodriguez <mcgrof@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Toshi Kani <toshi.kani@hp.com>
Link: http://lkml.kernel.org/r/20180515175759.89315-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 10 insertions, 11 deletions

diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index 558444b23923..42b4f2f3b557 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -149,17 +149,16 @@ mtrr_write(struct file *file, const char __user *buf, size_t len, loff_t * ppos)
                 return -EINVAL;
         ptr = skip_spaces(ptr + 5);
 
-        for (i = 0; i < MTRR_NUM_TYPES; ++i) {
-                if (strcmp(ptr, mtrr_strings[i]))
-                        continue;
-                base >>= PAGE_SHIFT;
-                size >>= PAGE_SHIFT;
-                err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
-                if (err < 0)
-                        return err;
-                return len;
-        }
-        return -EINVAL;
+        i = match_string(mtrr_strings, MTRR_NUM_TYPES, ptr);
+        if (i < 0)
+                return i;
+
+        base >>= PAGE_SHIFT;
+        size >>= PAGE_SHIFT;
+        err = mtrr_add_page((unsigned long)base, (unsigned long)size, i, true);
+        if (err < 0)
+                return err;
+        return len;
 }
 
 static long