[mirror_ubuntu-bionic-kernel.git] / drivers / mtd / devices / mtdram.c

/*
 * mtdram - a test mtd device
 * Author: Alexander Larsson <alex@cendio.se>
 *
 * Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
 * Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
 *
 * This code is GPL
 *
 */

#include <linux/module.h>
#include <linux/slab.h>
#include <linux/ioport.h>
#include <linux/vmalloc.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/mtdram.h>

static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
static unsigned long writebuf_size = 64;
#define MTDRAM_TOTAL_SIZE (total_size * 1024)
#define MTDRAM_ERASE_SIZE (erase_size * 1024)

#ifdef MODULE
module_param(total_size, ulong, 0);
MODULE_PARM_DESC(total_size, "Total device size in KiB");
module_param(erase_size, ulong, 0);
MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
module_param(writebuf_size, ulong, 0);
MODULE_PARM_DESC(writebuf_size, "Device write buf size in Bytes (Default: 64)");
#endif

// We could store these in the mtd structure, but we only support 1 device..
static struct mtd_info *mtd_info;

static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
	int ret = 0;

	/* Start address must align on block boundary */
	if (mtd_mod_by_eb(ofs, mtd)) {
		pr_debug("%s: unaligned address\n", __func__);
		ret = -EINVAL;
	}

	/* Length must align on block boundary */
	if (mtd_mod_by_eb(len, mtd)) {
		pr_debug("%s: length not block aligned\n", __func__);
		ret = -EINVAL;
	}

	return ret;
}

static int ram_erase(struct mtd_info *mtd, struct erase_info *instr)
{
	if (check_offs_len(mtd, instr->addr, instr->len))
		return -EINVAL;
	memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
	instr->state = MTD_ERASE_DONE;
	mtd_erase_callback(instr);
	return 0;
}

static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
		size_t *retlen, void **virt, resource_size_t *phys)
{
	*virt = mtd->priv + from;
	*retlen = len;

	if (phys) {
		/* limit retlen to the number of contiguous physical pages */
		unsigned long page_ofs = offset_in_page(*virt);
		void *addr = *virt - page_ofs;
		unsigned long pfn1, pfn0 = vmalloc_to_pfn(addr);

		*phys = __pfn_to_phys(pfn0) + page_ofs;
		len += page_ofs;
		while (len > PAGE_SIZE) {
			len -= PAGE_SIZE;
			addr += PAGE_SIZE;
			pfn0++;
			pfn1 = vmalloc_to_pfn(addr);
			if (pfn1 != pfn0) {
				*retlen = addr - *virt;
				break;
			}
		}
	}

	return 0;
}

static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
	return 0;
}

static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
		size_t *retlen, u_char *buf)
{
	memcpy(buf, mtd->priv + from, len);
	*retlen = len;
	return 0;
}

static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
		size_t *retlen, const u_char *buf)
{
	memcpy((char *)mtd->priv + to, buf, len);
	*retlen = len;
	return 0;
}

static void __exit cleanup_mtdram(void)
{
	if (mtd_info) {
		mtd_device_unregister(mtd_info);
		vfree(mtd_info->priv);
		kfree(mtd_info);
	}
}

int mtdram_init_device(struct mtd_info *mtd, void *mapped_address,
		unsigned long size, const char *name)
{
	memset(mtd, 0, sizeof(*mtd));

	/* Setup the MTD structure */
	mtd->name = name;
	mtd->type = MTD_RAM;
	mtd->flags = MTD_CAP_RAM;
	mtd->size = size;
	mtd->writesize = 1;
	mtd->writebufsize = writebuf_size;
	mtd->erasesize = MTDRAM_ERASE_SIZE;
	mtd->priv = mapped_address;

	mtd->owner = THIS_MODULE;
	mtd->_erase = ram_erase;
	mtd->_point = ram_point;
	mtd->_unpoint = ram_unpoint;
	mtd->_read = ram_read;
	mtd->_write = ram_write;

	if (mtd_device_register(mtd, NULL, 0))
		return -EIO;

	return 0;
}

static int __init init_mtdram(void)
{
	void *addr;
	int err;

	if (!total_size)
		return -EINVAL;

	/* Allocate some memory */
	mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
	if (!mtd_info)
		return -ENOMEM;

	addr = vmalloc(MTDRAM_TOTAL_SIZE);
	if (!addr) {
		kfree(mtd_info);
		mtd_info = NULL;
		return -ENOMEM;
	}
	err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
	if (err) {
		vfree(addr);
		kfree(mtd_info);
		mtd_info = NULL;
		return err;
	}
	memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
	return err;
}

module_init(init_mtdram);
module_exit(cleanup_mtdram);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
MODULE_DESCRIPTION("Simulated MTD driver for testing");
Commit	Line	Data
1da177e4 LT	1	/*
1da177e4 LT	2	* mtdram - a test mtd device
1da177e4 LT	3	* Author: Alexander Larsson <alex@cendio.se>
	4	*
	5	* Copyright (c) 1999 Alexander Larsson <alex@cendio.se>
c13cbf3b	6	* Copyright (c) 2005 Joern Engel <joern@wh.fh-wedel.de>
1da177e4 LT	7	*
	8	* This code is GPL
	9	*
	10	*/
	11
1da177e4 LT	12	#include <linux/module.h>
	13	#include <linux/slab.h>
	14	#include <linux/ioport.h>
	15	#include <linux/vmalloc.h>
877b58eb	16	#include <linux/mm.h>
1da177e4	17	#include <linux/init.h>
1da177e4	18	#include <linux/mtd/mtd.h>
456d9fc9	19	#include <linux/mtd/mtdram.h>
1da177e4	20
1da177e4 LT	21	static unsigned long total_size = CONFIG_MTDRAM_TOTAL_SIZE;
1da177e4 LT	22	static unsigned long erase_size = CONFIG_MTDRAM_ERASE_SIZE;
c67682c5	23	static unsigned long writebuf_size = 64;
1da177e4 LT	24	#define MTDRAM_TOTAL_SIZE (total_size * 1024)
1da177e4 LT	25	#define MTDRAM_ERASE_SIZE (erase_size * 1024)
1da177e4	26
c13cbf3b JE	27	#ifdef MODULE
	28	module_param(total_size, ulong, 0);
	29	MODULE_PARM_DESC(total_size, "Total device size in KiB");
	30	module_param(erase_size, ulong, 0);
	31	MODULE_PARM_DESC(erase_size, "Device erase block size in KiB");
c67682c5 AS	32	module_param(writebuf_size, ulong, 0);
c67682c5 AS	33	MODULE_PARM_DESC(writebuf_size, "Device write buf size in Bytes (Default: 64)");
c13cbf3b	34	#endif
1da177e4 LT	35
	36	// We could store these in the mtd structure, but we only support 1 device..
	37	static struct mtd_info *mtd_info;
	38
ab84fce5 DY	39	static int check_offs_len(struct mtd_info *mtd, loff_t ofs, uint64_t len)
	40	{
	41	int ret = 0;
	42
	43	/* Start address must align on block boundary */
	44	if (mtd_mod_by_eb(ofs, mtd)) {
	45	pr_debug("%s: unaligned address\n", __func__);
	46	ret = -EINVAL;
	47	}
	48
	49	/* Length must align on block boundary */
	50	if (mtd_mod_by_eb(len, mtd)) {
	51	pr_debug("%s: length not block aligned\n", __func__);
	52	ret = -EINVAL;
	53	}
	54
	55	return ret;
	56	}
	57
c13cbf3b	58	static int ram_erase(struct mtd_info mtd, struct erase_info instr)
1da177e4	59	{
ab84fce5 DY	60	if (check_offs_len(mtd, instr->addr, instr->len))
ab84fce5 DY	61	return -EINVAL;
c13cbf3b	62	memset((char *)mtd->priv + instr->addr, 0xff, instr->len);
c13cbf3b JE	63	instr->state = MTD_ERASE_DONE;
c13cbf3b JE	64	mtd_erase_callback(instr);
c13cbf3b	65	return 0;
1da177e4 LT	66	}
1da177e4 LT	67
c13cbf3b	68	static int ram_point(struct mtd_info *mtd, loff_t from, size_t len,
a98889f3	69	size_t retlen, void virt, resource_size_t phys)
1da177e4	70	{
a98889f3	71	*virt = mtd->priv + from;
c13cbf3b	72	*retlen = len;
877b58eb NP	73
	74	if (phys) {
	75	/* limit retlen to the number of contiguous physical pages */
	76	unsigned long page_ofs = offset_in_page(*virt);
	77	void addr = virt - page_ofs;
	78	unsigned long pfn1, pfn0 = vmalloc_to_pfn(addr);
	79
	80	*phys = __pfn_to_phys(pfn0) + page_ofs;
	81	len += page_ofs;
	82	while (len > PAGE_SIZE) {
	83	len -= PAGE_SIZE;
	84	addr += PAGE_SIZE;
	85	pfn0++;
	86	pfn1 = vmalloc_to_pfn(addr);
	87	if (pfn1 != pfn0) {
	88	retlen = addr - virt;
	89	break;
	90	}
	91	}
	92	}
	93
c13cbf3b	94	return 0;
1da177e4 LT	95	}
1da177e4 LT	96
5e4e6e3f	97	static int ram_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
1da177e4	98	{
5e4e6e3f	99	return 0;
1da177e4 LT	100	}
	101
	102	static int ram_read(struct mtd_info *mtd, loff_t from, size_t len,
c13cbf3b	103	size_t retlen, u_char buf)
1da177e4	104	{
c13cbf3b	105	memcpy(buf, mtd->priv + from, len);
c13cbf3b JE	106	*retlen = len;
c13cbf3b JE	107	return 0;
1da177e4 LT	108	}
	109
	110	static int ram_write(struct mtd_info *mtd, loff_t to, size_t len,
c13cbf3b	111	size_t retlen, const u_char buf)
1da177e4	112	{
c13cbf3b	113	memcpy((char *)mtd->priv + to, buf, len);
c13cbf3b JE	114	*retlen = len;
c13cbf3b JE	115	return 0;
1da177e4 LT	116	}
	117
	118	static void __exit cleanup_mtdram(void)
	119	{
c13cbf3b	120	if (mtd_info) {
ee0e87b1	121	mtd_device_unregister(mtd_info);
f9101210	122	vfree(mtd_info->priv);
c13cbf3b JE	123	kfree(mtd_info);
c13cbf3b JE	124	}
1da177e4 LT	125	}
1da177e4 LT	126
c13cbf3b	127	int mtdram_init_device(struct mtd_info mtd, void mapped_address,
0a8899b3	128	unsigned long size, const char *name)
1da177e4	129	{
c13cbf3b JE	130	memset(mtd, 0, sizeof(*mtd));
	131
	132	/* Setup the MTD structure */
	133	mtd->name = name;
21c8db9e	134	mtd->type = MTD_RAM;
c13cbf3b JE	135	mtd->flags = MTD_CAP_RAM;
c13cbf3b JE	136	mtd->size = size;
783ed81f	137	mtd->writesize = 1;
c67682c5	138	mtd->writebufsize = writebuf_size;
c13cbf3b JE	139	mtd->erasesize = MTDRAM_ERASE_SIZE;
	140	mtd->priv = mapped_address;
	141
	142	mtd->owner = THIS_MODULE;
3c3c10bb AB	143	mtd->_erase = ram_erase;
	144	mtd->_point = ram_point;
	145	mtd->_unpoint = ram_unpoint;
3c3c10bb AB	146	mtd->_read = ram_read;
3c3c10bb AB	147	mtd->_write = ram_write;
c13cbf3b	148
ee0e87b1	149	if (mtd_device_register(mtd, NULL, 0))
c13cbf3b	150	return -EIO;
c13cbf3b JE	151
c13cbf3b JE	152	return 0;
1da177e4	153	}
1da177e4 LT	154
	155	static int __init init_mtdram(void)
	156	{
c13cbf3b JE	157	void *addr;
	158	int err;
	159
	160	if (!total_size)
	161	return -EINVAL;
	162
	163	/* Allocate some memory */
	164	mtd_info = kmalloc(sizeof(struct mtd_info), GFP_KERNEL);
	165	if (!mtd_info)
	166	return -ENOMEM;
	167
	168	addr = vmalloc(MTDRAM_TOTAL_SIZE);
	169	if (!addr) {
	170	kfree(mtd_info);
	171	mtd_info = NULL;
	172	return -ENOMEM;
	173	}
	174	err = mtdram_init_device(mtd_info, addr, MTDRAM_TOTAL_SIZE, "mtdram test device");
	175	if (err) {
	176	vfree(addr);
	177	kfree(mtd_info);
	178	mtd_info = NULL;
	179	return err;
	180	}
	181	memset(mtd_info->priv, 0xff, MTDRAM_TOTAL_SIZE);
	182	return err;
1da177e4	183	}
1da177e4 LT	184
	185	module_init(init_mtdram);
	186	module_exit(cleanup_mtdram);
	187
	188	MODULE_LICENSE("GPL");
	189	MODULE_AUTHOR("Alexander Larsson <alexl@redhat.com>");
	190	MODULE_DESCRIPTION("Simulated MTD driver for testing");