From 7b0e67f604e1829e5292e1ad7743eb18dc42ea7c Mon Sep 17 00:00:00 2001 From: Robert Jarzmik Date: Thu, 22 Mar 2012 21:00:53 +0100 Subject: 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: Robert Jarzmik Signed-off-by: Artem Bityutskiy Signed-off-by: David Woodhouse --- drivers/mtd/devices/docg3.c | 50 +++++++++++++++++++++++++++++++++++---------- drivers/mtd/devices/docg3.h | 2 ++ 2 files changed, 41 insertions(+), 11 deletions(-) (limited to 'drivers/mtd') diff --git a/drivers/mtd/devices/docg3.c b/drivers/mtd/devices/docg3.c index 935d4c6e9321..8272c02668d6 100644 --- a/drivers/mtd/devices/docg3.c +++ b/drivers/mtd/devices/docg3.c @@ -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) diff --git a/drivers/mtd/devices/docg3.h b/drivers/mtd/devices/docg3.h index 642e60667cfd..19fb93f96a3a 100644 --- a/drivers/mtd/devices/docg3.h +++ b/drivers/mtd/devices/docg3.h @@ -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; }; /** -- cgit v1.2.3