Skip to content

Commit

Permalink
mtd: docg3 add protection against concurrency
Browse files Browse the repository at this point in the history 
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: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
  • Loading branch information
Robert Jarzmik authored and David Woodhouse committed Mar 27, 2012
1 parent 1b15a5f commit 7b0e67f
Show file tree
Hide file tree
Showing 2 changed files with 41 additions and 11 deletions.
50 changes: 39 additions & 11 deletions drivers/mtd/devices/docg3.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -875,14 +875,15 @@ 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);
nbdata = min_t(size_t, len, DOC_LAYOUT_PAGE_SIZE - skip);
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;
Expand Down Expand Up @@ -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;
}

/**
Expand Down Expand Up @@ -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,
Expand All @@ -1206,13 +1207,16 @@ 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;
ret = doc_erase_block(docg3, block0, block1);
block0 += 2;
block1 += 2;
}
mutex_unlock(&docg3->cascade->lock);

if (ret)
goto reset_err;
Expand Down Expand Up @@ -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;
Expand Down Expand Up @@ -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)
Expand All @@ -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;
}

Expand Down Expand Up @@ -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));
}
Expand All @@ -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));
}
Expand All @@ -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;
}

Expand All @@ -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;
}

Expand Down Expand Up @@ -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",
Expand All @@ -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 (",
Expand Down Expand Up @@ -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;
Expand All @@ -1699,13 +1724,15 @@ 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);
dps0_high = doc_register_readw(docg3, DOC_DPS0_ADDRHIGH);
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);
Expand Down Expand Up @@ -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)
Expand Down
2 changes: 2 additions & 0 deletions drivers/mtd/devices/docg3.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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;
};

/**
Expand Down

0 comments on commit 7b0e67f

Please sign in to comment.