mtd: mtd_pagetest: 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, 13 insertions, 30 deletions

diff --git a/drivers/mtd/tests/mtd_pagetest.c b/drivers/mtd/tests/mtd_pagetest.c
index f93a76f88113..0c1140b6c286 100644
--- a/drivers/mtd/tests/mtd_pagetest.c
+++ b/drivers/mtd/tests/mtd_pagetest.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);
@@ -45,26 +46,7 @@ static int bufsize;
 static int ebcnt;
 static int pgcnt;
 static int errcnt;
-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)
 {
@@ -98,7 +80,7 @@ static int write_eraseblock(int ebnum)
         size_t written;
         loff_t addr = ebnum * mtd->erasesize;
 
-        set_random_data(writebuf, mtd->erasesize);
+        prandom_bytes_state(&rnd_state, writebuf, mtd->erasesize);
         cond_resched();
         err = mtd_write(mtd, addr, mtd->erasesize, &written, writebuf);
         if (err || written != mtd->erasesize)
@@ -124,7 +106,7 @@ static int verify_eraseblock(int ebnum)
         for (i = 0; i < ebcnt && bbt[ebcnt - i - 1]; ++i)
                 addrn -= mtd->erasesize;
 
-        set_random_data(writebuf, mtd->erasesize);
+        prandom_bytes_state(&rnd_state, writebuf, mtd->erasesize);
         for (j = 0; j < pgcnt - 1; ++j, addr += pgsize) {
                 /* Do a read to set the internal dataRAMs to different data */
                 err = mtd_read(mtd, addr0, bufsize, &read, twopages);
@@ -160,7 +142,8 @@ static int verify_eraseblock(int ebnum)
         }
         /* Check boundary between eraseblocks */
         if (addr <= addrn - pgsize - pgsize && !bbt[ebnum + 1]) {
-                unsigned long oldnext = next;
+                struct rnd_state old_state = rnd_state;
+
                 /* Do a read to set the internal dataRAMs to different data */
                 err = mtd_read(mtd, addr0, bufsize, &read, twopages);
                 if (mtd_is_bitflip(err))
@@ -188,13 +171,13 @@ static int verify_eraseblock(int ebnum)
                         return err;
                 }
                 memcpy(boundary, writebuf + mtd->erasesize - pgsize, pgsize);
-                set_random_data(boundary + pgsize, pgsize);
+                prandom_bytes_state(&rnd_state, boundary + pgsize, pgsize);
                 if (memcmp(twopages, boundary, bufsize)) {
                         pr_err("error: verify failed at %#llx\n",
                                (long long)addr);
                         errcnt += 1;
                 }
-                next = oldnext;
+                rnd_state = old_state;
         }
         return err;
 }
@@ -326,7 +309,7 @@ static int erasecrosstest(void)
                 return err;
 
         pr_info("writing 1st page of block %d\n", ebnum);
-        set_random_data(writebuf, pgsize);
+        prandom_bytes_state(&rnd_state, writebuf, pgsize);
         strcpy(writebuf, "There is no data like this!");
         err = mtd_write(mtd, addr0, pgsize, &written, writebuf);
         if (err || written != pgsize) {
@@ -359,7 +342,7 @@ static int erasecrosstest(void)
                 return err;
 
         pr_info("writing 1st page of block %d\n", ebnum);
-        set_random_data(writebuf, pgsize);
+        prandom_bytes_state(&rnd_state, writebuf, pgsize);
         strcpy(writebuf, "There is no data like this!");
         err = mtd_write(mtd, addr0, pgsize, &written, writebuf);
         if (err || written != pgsize) {
@@ -417,7 +400,7 @@ static int erasetest(void)
                 return err;
 
         pr_info("writing 1st page of block %d\n", ebnum);
-        set_random_data(writebuf, pgsize);
+        prandom_bytes_state(&rnd_state, writebuf, pgsize);
         err = mtd_write(mtd, addr0, pgsize, &written, writebuf);
         if (err || written != pgsize) {
                 pr_err("error: write failed at %#llx\n",
@@ -565,7 +548,7 @@ static int __init mtd_pagetest_init(void)
         pr_info("erased %u eraseblocks\n", i);
 
         /* Write all eraseblocks */
-        simple_srand(1);
+        prandom_seed_state(&rnd_state, 1);
         pr_info("writing whole device\n");
         for (i = 0; i < ebcnt; ++i) {
                 if (bbt[i])
@@ -580,7 +563,7 @@ static int __init mtd_pagetest_init(void)
         pr_info("written %u eraseblocks\n", i);
 
         /* Check all eraseblocks */
-        simple_srand(1);
+        prandom_seed_state(&rnd_state, 1);
         pr_info("verifying all eraseblocks\n");
         for (i = 0; i < ebcnt; ++i) {
                 if (bbt[i])