mtd: mtd_oobtest: convert to use prandom library

This removes home-brewed pseudo-random number generator and use
prandom library.

Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Artem Bityutskiy <dedekind1@gmail.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: "Theodore Ts'o" <tytso@mit.edu>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Laight <david.laight@aculab.com>
Cc: Eilon Greenstein <eilong@broadcom.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Robert Love <robert.w.love@intel.com>
Cc: Valdis Kletnieks <valdis.kletnieks@vt.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 16 insertions, 33 deletions

diff --git a/drivers/mtd/tests/mtd_oobtest.c b/drivers/mtd/tests/mtd_oobtest.c
index e827fa8cd844..3e24b379ffa4 100644
--- a/drivers/mtd/tests/mtd_oobtest.c
+++ b/drivers/mtd/tests/mtd_oobtest.c
@@ -29,6 +29,7 @@
 #include <linux/mtd/mtd.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
+#include <linux/random.h>
 
 static int dev = -EINVAL;
 module_param(dev, int, S_IRUGO);
@@ -46,26 +47,7 @@ static int use_offset;
 static int use_len;
 static int use_len_max;
 static int vary_offset;
-static unsigned long next = 1;
-
-static inline unsigned int simple_rand(void)
-{
-        next = next * 1103515245 + 12345;
-        return (unsigned int)((next / 65536) % 32768);
-}
-
-static inline void simple_srand(unsigned long seed)
-{
-        next = seed;
-}
-
-static void set_random_data(unsigned char *buf, size_t len)
-{
-        size_t i;
-
-        for (i = 0; i < len; ++i)
-                buf[i] = simple_rand();
-}
+static struct rnd_state rnd_state;
 
 static int erase_eraseblock(int ebnum)
 {
@@ -129,7 +111,7 @@ static int write_eraseblock(int ebnum)
         loff_t addr = ebnum * mtd->erasesize;
 
         for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
-                set_random_data(writebuf, use_len);
+                prandom_bytes_state(&rnd_state, writebuf, use_len);
                 ops.mode      = MTD_OPS_AUTO_OOB;
                 ops.len       = 0;
                 ops.retlen    = 0;
@@ -182,7 +164,7 @@ static int verify_eraseblock(int ebnum)
         loff_t addr = ebnum * mtd->erasesize;
 
         for (i = 0; i < pgcnt; ++i, addr += mtd->writesize) {
-                set_random_data(writebuf, use_len);
+                prandom_bytes_state(&rnd_state, writebuf, use_len);
                 ops.mode      = MTD_OPS_AUTO_OOB;
                 ops.len       = 0;
                 ops.retlen    = 0;
@@ -273,7 +255,7 @@ static int verify_eraseblock_in_one_go(int ebnum)
         loff_t addr = ebnum * mtd->erasesize;
         size_t len = mtd->ecclayout->oobavail * pgcnt;
 
-        set_random_data(writebuf, len);
+        prandom_bytes_state(&rnd_state, writebuf, len);
         ops.mode      = MTD_OPS_AUTO_OOB;
         ops.len       = 0;
         ops.retlen    = 0;
@@ -424,12 +406,12 @@ static int __init mtd_oobtest_init(void)
         if (err)
                 goto out;
 
-        simple_srand(1);
+        prandom_seed_state(&rnd_state, 1);
         err = write_whole_device();
         if (err)
                 goto out;
 
-        simple_srand(1);
+        prandom_seed_state(&rnd_state, 1);
         err = verify_all_eraseblocks();
         if (err)
                 goto out;
@@ -444,13 +426,13 @@ static int __init mtd_oobtest_init(void)
         if (err)
                 goto out;
 
-        simple_srand(3);
+        prandom_seed_state(&rnd_state, 3);
         err = write_whole_device();
         if (err)
                 goto out;
 
         /* Check all eraseblocks */
-        simple_srand(3);
+        prandom_seed_state(&rnd_state, 3);
         pr_info("verifying all eraseblocks\n");
         for (i = 0; i < ebcnt; ++i) {
                 if (bbt[i])
@@ -479,7 +461,7 @@ static int __init mtd_oobtest_init(void)
         use_len = mtd->ecclayout->oobavail;
         use_len_max = mtd->ecclayout->oobavail;
         vary_offset = 1;
-        simple_srand(5);
+        prandom_seed_state(&rnd_state, 5);
 
         err = write_whole_device();
         if (err)
@@ -490,7 +472,7 @@ static int __init mtd_oobtest_init(void)
         use_len = mtd->ecclayout->oobavail;
         use_len_max = mtd->ecclayout->oobavail;
         vary_offset = 1;
-        simple_srand(5);
+        prandom_seed_state(&rnd_state, 5);
         err = verify_all_eraseblocks();
         if (err)
                 goto out;
@@ -649,7 +631,7 @@ static int __init mtd_oobtest_init(void)
                 goto out;
 
         /* Write all eraseblocks */
-        simple_srand(11);
+        prandom_seed_state(&rnd_state, 11);
         pr_info("writing OOBs of whole device\n");
         for (i = 0; i < ebcnt - 1; ++i) {
                 int cnt = 2;
@@ -659,7 +641,7 @@ static int __init mtd_oobtest_init(void)
                         continue;
                 addr = (i + 1) * mtd->erasesize - mtd->writesize;
                 for (pg = 0; pg < cnt; ++pg) {
-                        set_random_data(writebuf, sz);
+                        prandom_bytes_state(&rnd_state, writebuf, sz);
                         ops.mode      = MTD_OPS_AUTO_OOB;
                         ops.len       = 0;
                         ops.retlen    = 0;
@@ -680,12 +662,13 @@ static int __init mtd_oobtest_init(void)
         pr_info("written %u eraseblocks\n", i);
 
         /* Check all eraseblocks */
-        simple_srand(11);
+        prandom_seed_state(&rnd_state, 11);
         pr_info("verifying all eraseblocks\n");
         for (i = 0; i < ebcnt - 1; ++i) {
                 if (bbt[i] || bbt[i + 1])
                         continue;
-                set_random_data(writebuf, mtd->ecclayout->oobavail * 2);
+                prandom_bytes_state(&rnd_state, writebuf,
+                                        mtd->ecclayout->oobavail * 2);
                 addr = (i + 1) * mtd->erasesize - mtd->writesize;
                 ops.mode      = MTD_OPS_AUTO_OOB;
                 ops.len       = 0;