/*
   * Copyright (C) 2007 Nokia Corporation
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published by
   * the Free Software Foundation.
   *
   * This program is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
   * more details.
   *
   * You should have received a copy of the GNU General Public License along with
   * this program; see the file COPYING. If not, write to the Free Software
   * Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   *
   * Test read and write speed of a MTD device.
   *
   * Author: Adrian Hunter <adrian.hunter@nokia.com>
   */
  
  #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/moduleparam.h>
  #include <linux/err.h>
  #include <linux/mtd/mtd.h>
  #include <linux/slab.h>
  #include <linux/sched.h>
  #include <linux/random.h>
  
  #include "mtd_test.h"
  
  static int dev = -EINVAL;
  module_param(dev, int, S_IRUGO);
  MODULE_PARM_DESC(dev, "MTD device number to use");
  
  static int count;
  module_param(count, int, S_IRUGO);
  MODULE_PARM_DESC(count, "Maximum number of eraseblocks to use "
  			"(0 means use all)");
  
  static struct mtd_info *mtd;
  static unsigned char *iobuf;
  static unsigned char *bbt;
  
  static int pgsize;
  static int ebcnt;
  static int pgcnt;
  static int goodebcnt;
  static struct timeval start, finish;
  
  static int multiblock_erase(int ebnum, int blocks)
  {
  	int err;
  	struct erase_info ei;
  	loff_t addr = ebnum * mtd->erasesize;
  
  	memset(&ei, 0, sizeof(struct erase_info));
  	ei.mtd  = mtd;
  	ei.addr = addr;
  	ei.len  = mtd->erasesize * blocks;
  
  	err = mtd_erase(mtd, &ei);
  	if (err) {
  		pr_err("error %d while erasing EB %d, blocks %d
  ",
  		       err, ebnum, blocks);
  		return err;
  	}
  
  	if (ei.state == MTD_ERASE_FAILED) {
  		pr_err("some erase error occurred at EB %d,"
  		       "blocks %d
  ", ebnum, blocks);
  		return -EIO;
  	}
  
  	return 0;
  }
  
  static int write_eraseblock(int ebnum)
  {
  	loff_t addr = ebnum * mtd->erasesize;
  
  	return mtdtest_write(mtd, addr, mtd->erasesize, iobuf);
  }
  
  static int write_eraseblock_by_page(int ebnum)
  {
  	int i, err = 0;
  	loff_t addr = ebnum * mtd->erasesize;
  	void *buf = iobuf;
  
  	for (i = 0; i < pgcnt; i++) {
  		err = mtdtest_write(mtd, addr, pgsize, buf);
  		if (err)
  			break;
  		addr += pgsize;
  		buf += pgsize;
  	}
  
  	return err;
  }
  
  static int write_eraseblock_by_2pages(int ebnum)
  {
  	size_t sz = pgsize * 2;
  	int i, n = pgcnt / 2, err = 0;
  	loff_t addr = ebnum * mtd->erasesize;
  	void *buf = iobuf;
  
  	for (i = 0; i < n; i++) {
  		err = mtdtest_write(mtd, addr, sz, buf);
  		if (err)
  			return err;
  		addr += sz;
  		buf += sz;
  	}
  	if (pgcnt % 2)
  		err = mtdtest_write(mtd, addr, pgsize, buf);
  
  	return err;
  }
  
  static int read_eraseblock(int ebnum)
  {
  	loff_t addr = ebnum * mtd->erasesize;
  
  	return mtdtest_read(mtd, addr, mtd->erasesize, iobuf);
  }
  
  static int read_eraseblock_by_page(int ebnum)
  {
  	int i, err = 0;
  	loff_t addr = ebnum * mtd->erasesize;
  	void *buf = iobuf;
  
  	for (i = 0; i < pgcnt; i++) {
  		err = mtdtest_read(mtd, addr, pgsize, buf);
  		if (err)
  			break;
  		addr += pgsize;
  		buf += pgsize;
  	}
  
  	return err;
  }
  
  static int read_eraseblock_by_2pages(int ebnum)
  {
  	size_t sz = pgsize * 2;
  	int i, n = pgcnt / 2, err = 0;
  	loff_t addr = ebnum * mtd->erasesize;
  	void *buf = iobuf;
  
  	for (i = 0; i < n; i++) {
  		err = mtdtest_read(mtd, addr, sz, buf);
  		if (err)
  			return err;
  		addr += sz;
  		buf += sz;
  	}
  	if (pgcnt % 2)
  		err = mtdtest_read(mtd, addr, pgsize, buf);
  
  	return err;
  }
  
  static inline void start_timing(void)
  {
  	do_gettimeofday(&start);
  }
  
  static inline void stop_timing(void)
  {
  	do_gettimeofday(&finish);
  }
  
  static long calc_speed(void)
  {
  	uint64_t k;
  	long ms;
  
  	ms = (finish.tv_sec - start.tv_sec) * 1000 +
  	     (finish.tv_usec - start.tv_usec) / 1000;
  	if (ms == 0)
  		return 0;
  	k = goodebcnt * (mtd->erasesize / 1024) * 1000;
  	do_div(k, ms);
  	return k;
  }
  
  static int __init mtd_speedtest_init(void)
  {
  	int err, i, blocks, j, k;
  	long speed;
  	uint64_t tmp;
  
  	printk(KERN_INFO "
  ");
  	printk(KERN_INFO "=================================================
  ");
  
  	if (dev < 0) {
  		pr_info("Please specify a valid mtd-device via module parameter
  ");
  		pr_crit("CAREFUL: This test wipes all data on the specified MTD device!
  ");
  		return -EINVAL;
  	}
  
  	if (count)
  		pr_info("MTD device: %d    count: %d
  ", dev, count);
  	else
  		pr_info("MTD device: %d
  ", dev);
  
  	mtd = get_mtd_device(NULL, dev);
  	if (IS_ERR(mtd)) {
  		err = PTR_ERR(mtd);
  		pr_err("error: cannot get MTD device
  ");
  		return err;
  	}
  
  	if (mtd->writesize == 1) {
  		pr_info("not NAND flash, assume page size is 512 "
  		       "bytes.
  ");
  		pgsize = 512;
  	} else
  		pgsize = mtd->writesize;
  
  	tmp = mtd->size;
  	do_div(tmp, mtd->erasesize);
  	ebcnt = tmp;
  	pgcnt = mtd->erasesize / pgsize;
  
  	pr_info("MTD device size %llu, eraseblock size %u, "
  	       "page size %u, count of eraseblocks %u, pages per "
  	       "eraseblock %u, OOB size %u
  ",
  	       (unsigned long long)mtd->size, mtd->erasesize,
  	       pgsize, ebcnt, pgcnt, mtd->oobsize);
  
  	if (count > 0 && count < ebcnt)
  		ebcnt = count;
  
  	err = -ENOMEM;
  	iobuf = kmalloc(mtd->erasesize, GFP_KERNEL);
  	if (!iobuf)
  		goto out;
  
  	prandom_bytes(iobuf, mtd->erasesize);
  
  	bbt = kzalloc(ebcnt, GFP_KERNEL);
  	if (!bbt)
  		goto out;
  	err = mtdtest_scan_for_bad_eraseblocks(mtd, bbt, 0, ebcnt);
  	if (err)
  		goto out;
  	for (i = 0; i < ebcnt; i++) {
  		if (!bbt[i])
  			goodebcnt++;
  	}
  
  	err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
  	if (err)
  		goto out;
  
  	/* Write all eraseblocks, 1 eraseblock at a time */
  	pr_info("testing eraseblock write speed
  ");
  	start_timing();
  	for (i = 0; i < ebcnt; ++i) {
  		if (bbt[i])
  			continue;
  		err = write_eraseblock(i);
  		if (err)
  			goto out;
  		cond_resched();
  	}
  	stop_timing();
  	speed = calc_speed();
  	pr_info("eraseblock write speed is %ld KiB/s
  ", speed);
  
  	/* Read all eraseblocks, 1 eraseblock at a time */
  	pr_info("testing eraseblock read speed
  ");
  	start_timing();
  	for (i = 0; i < ebcnt; ++i) {
  		if (bbt[i])
  			continue;
  		err = read_eraseblock(i);
  		if (err)
  			goto out;
  		cond_resched();
  	}
  	stop_timing();
  	speed = calc_speed();
  	pr_info("eraseblock read speed is %ld KiB/s
  ", speed);
  
  	err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
  	if (err)
  		goto out;
  
  	/* Write all eraseblocks, 1 page at a time */
  	pr_info("testing page write speed
  ");
  	start_timing();
  	for (i = 0; i < ebcnt; ++i) {
  		if (bbt[i])
  			continue;
  		err = write_eraseblock_by_page(i);
  		if (err)
  			goto out;
  		cond_resched();
  	}
  	stop_timing();
  	speed = calc_speed();
  	pr_info("page write speed is %ld KiB/s
  ", speed);
  
  	/* Read all eraseblocks, 1 page at a time */
  	pr_info("testing page read speed
  ");
  	start_timing();
  	for (i = 0; i < ebcnt; ++i) {
  		if (bbt[i])
  			continue;
  		err = read_eraseblock_by_page(i);
  		if (err)
  			goto out;
  		cond_resched();
  	}
  	stop_timing();
  	speed = calc_speed();
  	pr_info("page read speed is %ld KiB/s
  ", speed);
  
  	err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
  	if (err)
  		goto out;
  
  	/* Write all eraseblocks, 2 pages at a time */
  	pr_info("testing 2 page write speed
  ");
  	start_timing();
  	for (i = 0; i < ebcnt; ++i) {
  		if (bbt[i])
  			continue;
  		err = write_eraseblock_by_2pages(i);
  		if (err)
  			goto out;
  		cond_resched();
  	}
  	stop_timing();
  	speed = calc_speed();
  	pr_info("2 page write speed is %ld KiB/s
  ", speed);
  
  	/* Read all eraseblocks, 2 pages at a time */
  	pr_info("testing 2 page read speed
  ");
  	start_timing();
  	for (i = 0; i < ebcnt; ++i) {
  		if (bbt[i])
  			continue;
  		err = read_eraseblock_by_2pages(i);
  		if (err)
  			goto out;
  		cond_resched();
  	}
  	stop_timing();
  	speed = calc_speed();
  	pr_info("2 page read speed is %ld KiB/s
  ", speed);
  
  	/* Erase all eraseblocks */
  	pr_info("Testing erase speed
  ");
  	start_timing();
  	err = mtdtest_erase_good_eraseblocks(mtd, bbt, 0, ebcnt);
  	if (err)
  		goto out;
  	stop_timing();
  	speed = calc_speed();
  	pr_info("erase speed is %ld KiB/s
  ", speed);
  
  	/* Multi-block erase all eraseblocks */
  	for (k = 1; k < 7; k++) {
  		blocks = 1 << k;
  		pr_info("Testing %dx multi-block erase speed
  ",
  		       blocks);
  		start_timing();
  		for (i = 0; i < ebcnt; ) {
  			for (j = 0; j < blocks && (i + j) < ebcnt; j++)
  				if (bbt[i + j])
  					break;
  			if (j < 1) {
  				i++;
  				continue;
  			}
  			err = multiblock_erase(i, j);
  			if (err)
  				goto out;
  			cond_resched();
  			i += j;
  		}
  		stop_timing();
  		speed = calc_speed();
  		pr_info("%dx multi-block erase speed is %ld KiB/s
  ",
  		       blocks, speed);
  	}
  	pr_info("finished
  ");
  out:
  	kfree(iobuf);
  	kfree(bbt);
  	put_mtd_device(mtd);
  	if (err)
  		pr_info("error %d occurred
  ", err);
  	printk(KERN_INFO "=================================================
  ");
  	return err;
  }
  module_init(mtd_speedtest_init);
  
  static void __exit mtd_speedtest_exit(void)
  {
  	return;
  }
  module_exit(mtd_speedtest_exit);
  
  MODULE_DESCRIPTION("Speed test module");
  MODULE_AUTHOR("Adrian Hunter");
  MODULE_LICENSE("GPL");