Commit 7b0e67f6 authored by Robert Jarzmik's avatar Robert Jarzmik Committed by David Woodhouse
Browse files

mtd: docg3 add protection against concurrency 



As docg3 is intolerant against reentrancy, especially
because of its weird register access (ie. a register read is
performed by a first register write), each access to the
docg3 IO space must be locked.

Lock the IO space with a mutex, shared by all chips on the
same cascade, as they all share the same IO space.

Signed-off-by: default avatarRobert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: default avatarArtem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: default avatarDavid Woodhouse <David.Woodhouse@intel.com>
parent 1b15a5f9

drivers/mtd/devices/docg3.c

+39 −11
Original line number Diff line number Diff line
@@ -875,6 +875,7 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from, 
	ops->retlen = 0;

	ret = 0;

	skip = from % DOC_LAYOUT_PAGE_SIZE;

	mutex_lock(&docg3->cascade->lock);

	while (!ret && (len > 0 || ooblen > 0)) {

		calc_block_sector(from - skip, &block0, &block1, &page, &ofs,

			docg3->reliable);
@@ -882,7 +883,7 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from, 
		nboob = min_t(size_t, ooblen, (size_t)DOC_LAYOUT_OOB_SIZE);

		ret = doc_read_page_prepare(docg3, block0, block1, page, ofs);

		if (ret < 0)

			goto err;

			goto out;

		ret = doc_read_page_ecc_init(docg3, DOC_ECC_BCH_TOTAL_BYTES);

		if (ret < 0)

			goto err_in_read;
@@ -950,11 +951,12 @@ static int doc_read_oob(struct mtd_info *mtd, loff_t from, 
		skip = 0;

	}



out:

	mutex_unlock(&docg3->cascade->lock);

	return ret;

err_in_read:

	doc_read_page_finish(docg3);

err:

	return ret;

	goto out;

}



/**
@@ -1194,7 +1196,6 @@ static int doc_erase(struct mtd_info *mtd, struct erase_info *info) 
	int block0, block1, page, ret, ofs = 0;



	doc_dbg("doc_erase(from=%lld, len=%lld\n", info->addr, info->len);

	doc_set_device_id(docg3, docg3->device_id);



	info->state = MTD_ERASE_PENDING;

	calc_block_sector(info->addr + info->len, &block0, &block1, &page,
@@ -1206,6 +1207,8 @@ static int doc_erase(struct mtd_info *mtd, struct erase_info *info) 
	ret = 0;

	calc_block_sector(info->addr, &block0, &block1, &page, &ofs,

			  docg3->reliable);

	mutex_lock(&docg3->cascade->lock);

	doc_set_device_id(docg3, docg3->device_id);

	doc_set_reliable_mode(docg3);

	for (len = info->len; !ret && len > 0; len -= mtd->erasesize) {

		info->state = MTD_ERASING;
@@ -1213,6 +1216,7 @@ static int doc_erase(struct mtd_info *mtd, struct erase_info *info) 
		block0 += 2;

		block1 += 2;

	}

	mutex_unlock(&docg3->cascade->lock);



	if (ret)

		goto reset_err;
@@ -1399,7 +1403,7 @@ static int doc_write_oob(struct mtd_info *mtd, loff_t ofs, 
			 struct mtd_oob_ops *ops)

{

	struct docg3 *docg3 = mtd->priv;

	int block0, block1, page, ret, pofs = 0, autoecc, oobdelta;

	int ret, autoecc, oobdelta;

	u8 *oobbuf = ops->oobbuf;

	u8 *buf = ops->datbuf;

	size_t len, ooblen;
@@ -1451,6 +1455,7 @@ static int doc_write_oob(struct mtd_info *mtd, loff_t ofs, 
	if (autoecc < 0)

		return autoecc;



	mutex_lock(&docg3->cascade->lock);

	while (!ret && len > 0) {

		memset(oob, 0, sizeof(oob));

		if (ofs == docg3->oob_write_ofs)
@@ -1471,8 +1476,9 @@ static int doc_write_oob(struct mtd_info *mtd, loff_t ofs, 
		}

		ops->retlen += DOC_LAYOUT_PAGE_SIZE;

	}

err:



	doc_set_device_id(docg3, 0);

	mutex_unlock(&docg3->cascade->lock);

	return ret;

}
@@ -1529,9 +1535,11 @@ static ssize_t dps0_is_key_locked(struct device *dev, 
	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);

	int dps0;



	mutex_lock(&docg3->cascade->lock);

	doc_set_device_id(docg3, docg3->device_id);

	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);

	doc_set_device_id(docg3, 0);

	mutex_unlock(&docg3->cascade->lock);



	return sprintf(buf, "%d\n", !(dps0 & DOC_DPS_KEY_OK));

}
@@ -1542,9 +1550,11 @@ static ssize_t dps1_is_key_locked(struct device *dev, 
	struct docg3 *docg3 = sysfs_dev2docg3(dev, attr);

	int dps1;



	mutex_lock(&docg3->cascade->lock);

	doc_set_device_id(docg3, docg3->device_id);

	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);

	doc_set_device_id(docg3, 0);

	mutex_unlock(&docg3->cascade->lock);



	return sprintf(buf, "%d\n", !(dps1 & DOC_DPS_KEY_OK));

}
@@ -1559,10 +1569,12 @@ static ssize_t dps0_insert_key(struct device *dev, 
	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)

		return -EINVAL;



	mutex_lock(&docg3->cascade->lock);

	doc_set_device_id(docg3, docg3->device_id);

	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)

		doc_writeb(docg3, buf[i], DOC_DPS0_KEY);

	doc_set_device_id(docg3, 0);

	mutex_unlock(&docg3->cascade->lock);

	return count;

}
@@ -1576,10 +1588,12 @@ static ssize_t dps1_insert_key(struct device *dev, 
	if (count != DOC_LAYOUT_DPS_KEY_LENGTH)

		return -EINVAL;



	mutex_lock(&docg3->cascade->lock);

	doc_set_device_id(docg3, docg3->device_id);

	for (i = 0; i < DOC_LAYOUT_DPS_KEY_LENGTH; i++)

		doc_writeb(docg3, buf[i], DOC_DPS1_KEY);

	doc_set_device_id(docg3, 0);

	mutex_unlock(&docg3->cascade->lock);

	return count;

}
@@ -1634,7 +1648,11 @@ static int dbg_flashctrl_show(struct seq_file *s, void *p) 
	struct docg3 *docg3 = (struct docg3 *)s->private;



	int pos = 0;

	u8 fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);

	u8 fctrl;



	mutex_lock(&docg3->cascade->lock);

	fctrl = doc_register_readb(docg3, DOC_FLASHCONTROL);

	mutex_unlock(&docg3->cascade->lock);



	pos += seq_printf(s,

		 "FlashControl : 0x%02x (%s,CE# %s,%s,%s,flash %s)\n",
@@ -1652,9 +1670,12 @@ static int dbg_asicmode_show(struct seq_file *s, void *p) 
{

	struct docg3 *docg3 = (struct docg3 *)s->private;



	int pos = 0;

	int pctrl = doc_register_readb(docg3, DOC_ASICMODE);

	int mode = pctrl & 0x03;

	int pos = 0, pctrl, mode;



	mutex_lock(&docg3->cascade->lock);

	pctrl = doc_register_readb(docg3, DOC_ASICMODE);

	mode = pctrl & 0x03;

	mutex_unlock(&docg3->cascade->lock);



	pos += seq_printf(s,

			 "%04x : RAM_WE=%d,RSTIN_RESET=%d,BDETCT_RESET=%d,WRITE_ENABLE=%d,POWERDOWN=%d,MODE=%d%d (",
@@ -1686,7 +1707,11 @@ static int dbg_device_id_show(struct seq_file *s, void *p) 
{

	struct docg3 *docg3 = (struct docg3 *)s->private;

	int pos = 0;

	int id = doc_register_readb(docg3, DOC_DEVICESELECT);

	int id;



	mutex_lock(&docg3->cascade->lock);

	id = doc_register_readb(docg3, DOC_DEVICESELECT);

	mutex_unlock(&docg3->cascade->lock);



	pos += seq_printf(s, "DeviceId = %d\n", id);

	return pos;
@@ -1699,6 +1724,7 @@ static int dbg_protection_show(struct seq_file *s, void *p) 
	int pos = 0;

	int protect, dps0, dps0_low, dps0_high, dps1, dps1_low, dps1_high;



	mutex_lock(&docg3->cascade->lock);

	protect = doc_register_readb(docg3, DOC_PROTECTION);

	dps0 = doc_register_readb(docg3, DOC_DPS0_STATUS);

	dps0_low = doc_register_readw(docg3, DOC_DPS0_ADDRLOW);
@@ -1706,6 +1732,7 @@ static int dbg_protection_show(struct seq_file *s, void *p) 
	dps1 = doc_register_readb(docg3, DOC_DPS1_STATUS);

	dps1_low = doc_register_readw(docg3, DOC_DPS1_ADDRLOW);

	dps1_high = doc_register_readw(docg3, DOC_DPS1_ADDRHIGH);

	mutex_unlock(&docg3->cascade->lock);



	pos += seq_printf(s, "Protection = 0x%02x (",

			 protect);
@@ -2022,6 +2049,7 @@ static int __init docg3_probe(struct platform_device *pdev) 
	if (!cascade)

		goto nomem1;

	cascade->base = base;

	mutex_init(&cascade->lock);

	cascade->bch = init_bch(DOC_ECC_BCH_M, DOC_ECC_BCH_T,

			     DOC_ECC_BCH_PRIMPOLY);

	if (!cascade->bch)

drivers/mtd/devices/docg3.h

+2 −0
Original line number Diff line number Diff line
@@ -273,11 +273,13 @@ 
 * @floors: floors (ie. one physical docg3 chip is one floor)

 * @base: IO space to access all chips in the cascade

 * @bch: the BCH correcting control structure

 * @lock: lock to protect docg3 IO space from concurrent accesses

 */

struct docg3_cascade {

	struct mtd_info *floors[DOC_MAX_NBFLOORS];

	void __iomem *base;

	struct bch_control *bch;

	struct mutex lock;

};



/**

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