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path: root/drivers/mtd/chips/cfi_cmdset_0002.c
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Diffstat (limited to 'drivers/mtd/chips/cfi_cmdset_0002.c')
-rw-r--r--drivers/mtd/chips/cfi_cmdset_0002.c283
1 files changed, 252 insertions, 31 deletions
diff --git a/drivers/mtd/chips/cfi_cmdset_0002.c b/drivers/mtd/chips/cfi_cmdset_0002.c
index 8d70895a58d6..d02592e6a0f0 100644
--- a/drivers/mtd/chips/cfi_cmdset_0002.c
+++ b/drivers/mtd/chips/cfi_cmdset_0002.c
@@ -59,6 +59,9 @@ static void cfi_amdstd_resume (struct mtd_info *);
static int cfi_amdstd_reboot(struct notifier_block *, unsigned long, void *);
static int cfi_amdstd_secsi_read (struct mtd_info *, loff_t, size_t, size_t *, u_char *);
+static int cfi_amdstd_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const u_char *buf);
+
static void cfi_amdstd_destroy(struct mtd_info *);
struct mtd_info *cfi_cmdset_0002(struct map_info *, int);
@@ -189,7 +192,7 @@ static void fixup_use_write_buffers(struct mtd_info *mtd)
struct cfi_private *cfi = map->fldrv_priv;
if (cfi->cfiq->BufWriteTimeoutTyp) {
pr_debug("Using buffer write method\n" );
- mtd->write = cfi_amdstd_write_buffers;
+ mtd->_write = cfi_amdstd_write_buffers;
}
}
@@ -228,8 +231,8 @@ static void fixup_convert_atmel_pri(struct mtd_info *mtd)
static void fixup_use_secsi(struct mtd_info *mtd)
{
/* Setup for chips with a secsi area */
- mtd->read_user_prot_reg = cfi_amdstd_secsi_read;
- mtd->read_fact_prot_reg = cfi_amdstd_secsi_read;
+ mtd->_read_user_prot_reg = cfi_amdstd_secsi_read;
+ mtd->_read_fact_prot_reg = cfi_amdstd_secsi_read;
}
static void fixup_use_erase_chip(struct mtd_info *mtd)
@@ -238,7 +241,7 @@ static void fixup_use_erase_chip(struct mtd_info *mtd)
struct cfi_private *cfi = map->fldrv_priv;
if ((cfi->cfiq->NumEraseRegions == 1) &&
((cfi->cfiq->EraseRegionInfo[0] & 0xffff) == 0)) {
- mtd->erase = cfi_amdstd_erase_chip;
+ mtd->_erase = cfi_amdstd_erase_chip;
}
}
@@ -249,8 +252,8 @@ static void fixup_use_erase_chip(struct mtd_info *mtd)
*/
static void fixup_use_atmel_lock(struct mtd_info *mtd)
{
- mtd->lock = cfi_atmel_lock;
- mtd->unlock = cfi_atmel_unlock;
+ mtd->_lock = cfi_atmel_lock;
+ mtd->_unlock = cfi_atmel_unlock;
mtd->flags |= MTD_POWERUP_LOCK;
}
@@ -429,12 +432,12 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
mtd->type = MTD_NORFLASH;
/* Fill in the default mtd operations */
- mtd->erase = cfi_amdstd_erase_varsize;
- mtd->write = cfi_amdstd_write_words;
- mtd->read = cfi_amdstd_read;
- mtd->sync = cfi_amdstd_sync;
- mtd->suspend = cfi_amdstd_suspend;
- mtd->resume = cfi_amdstd_resume;
+ mtd->_erase = cfi_amdstd_erase_varsize;
+ mtd->_write = cfi_amdstd_write_words;
+ mtd->_read = cfi_amdstd_read;
+ mtd->_sync = cfi_amdstd_sync;
+ mtd->_suspend = cfi_amdstd_suspend;
+ mtd->_resume = cfi_amdstd_resume;
mtd->flags = MTD_CAP_NORFLASH;
mtd->name = map->name;
mtd->writesize = 1;
@@ -443,6 +446,7 @@ struct mtd_info *cfi_cmdset_0002(struct map_info *map, int primary)
pr_debug("MTD %s(): write buffer size %d\n", __func__,
mtd->writebufsize);
+ mtd->_panic_write = cfi_amdstd_panic_write;
mtd->reboot_notifier.notifier_call = cfi_amdstd_reboot;
if (cfi->cfi_mode==CFI_MODE_CFI){
@@ -770,8 +774,6 @@ static void put_chip(struct map_info *map, struct flchip *chip, unsigned long ad
case FL_READY:
case FL_STATUS:
- /* We should really make set_vpp() count, rather than doing this */
- DISABLE_VPP(map);
break;
default:
printk(KERN_ERR "MTD: put_chip() called with oldstate %d!!\n", chip->oldstate);
@@ -1013,13 +1015,9 @@ static int cfi_amdstd_read (struct mtd_info *mtd, loff_t from, size_t len, size_
int ret = 0;
/* ofs: offset within the first chip that the first read should start */
-
chipnum = (from >> cfi->chipshift);
ofs = from - (chipnum << cfi->chipshift);
-
- *retlen = 0;
-
while (len) {
unsigned long thislen;
@@ -1097,16 +1095,11 @@ static int cfi_amdstd_secsi_read (struct mtd_info *mtd, loff_t from, size_t len,
int chipnum;
int ret = 0;
-
/* ofs: offset within the first chip that the first read should start */
-
/* 8 secsi bytes per chip */
chipnum=from>>3;
ofs=from & 7;
-
- *retlen = 0;
-
while (len) {
unsigned long thislen;
@@ -1234,6 +1227,7 @@ static int __xipram do_write_oneword(struct map_info *map, struct flchip *chip,
xip_enable(map, chip, adr);
op_done:
chip->state = FL_READY;
+ DISABLE_VPP(map);
put_chip(map, chip, adr);
mutex_unlock(&chip->mutex);
@@ -1251,10 +1245,6 @@ static int cfi_amdstd_write_words(struct mtd_info *mtd, loff_t to, size_t len,
unsigned long ofs, chipstart;
DECLARE_WAITQUEUE(wait, current);
- *retlen = 0;
- if (!len)
- return 0;
-
chipnum = to >> cfi->chipshift;
ofs = to - (chipnum << cfi->chipshift);
chipstart = cfi->chips[chipnum].start;
@@ -1476,6 +1466,7 @@ static int __xipram do_write_buffer(struct map_info *map, struct flchip *chip,
ret = -EIO;
op_done:
chip->state = FL_READY;
+ DISABLE_VPP(map);
put_chip(map, chip, adr);
mutex_unlock(&chip->mutex);
@@ -1493,10 +1484,6 @@ static int cfi_amdstd_write_buffers(struct mtd_info *mtd, loff_t to, size_t len,
int chipnum;
unsigned long ofs;
- *retlen = 0;
- if (!len)
- return 0;
-
chipnum = to >> cfi->chipshift;
ofs = to - (chipnum << cfi->chipshift);
@@ -1562,6 +1549,238 @@ static int cfi_amdstd_write_buffers(struct mtd_info *mtd, loff_t to, size_t len,
return 0;
}
+/*
+ * Wait for the flash chip to become ready to write data
+ *
+ * This is only called during the panic_write() path. When panic_write()
+ * is called, the kernel is in the process of a panic, and will soon be
+ * dead. Therefore we don't take any locks, and attempt to get access
+ * to the chip as soon as possible.
+ */
+static int cfi_amdstd_panic_wait(struct map_info *map, struct flchip *chip,
+ unsigned long adr)
+{
+ struct cfi_private *cfi = map->fldrv_priv;
+ int retries = 10;
+ int i;
+
+ /*
+ * If the driver thinks the chip is idle, and no toggle bits
+ * are changing, then the chip is actually idle for sure.
+ */
+ if (chip->state == FL_READY && chip_ready(map, adr))
+ return 0;
+
+ /*
+ * Try several times to reset the chip and then wait for it
+ * to become idle. The upper limit of a few milliseconds of
+ * delay isn't a big problem: the kernel is dying anyway. It
+ * is more important to save the messages.
+ */
+ while (retries > 0) {
+ const unsigned long timeo = (HZ / 1000) + 1;
+
+ /* send the reset command */
+ map_write(map, CMD(0xF0), chip->start);
+
+ /* wait for the chip to become ready */
+ for (i = 0; i < jiffies_to_usecs(timeo); i++) {
+ if (chip_ready(map, adr))
+ return 0;
+
+ udelay(1);
+ }
+ }
+
+ /* the chip never became ready */
+ return -EBUSY;
+}
+
+/*
+ * Write out one word of data to a single flash chip during a kernel panic
+ *
+ * This is only called during the panic_write() path. When panic_write()
+ * is called, the kernel is in the process of a panic, and will soon be
+ * dead. Therefore we don't take any locks, and attempt to get access
+ * to the chip as soon as possible.
+ *
+ * The implementation of this routine is intentionally similar to
+ * do_write_oneword(), in order to ease code maintenance.
+ */
+static int do_panic_write_oneword(struct map_info *map, struct flchip *chip,
+ unsigned long adr, map_word datum)
+{
+ const unsigned long uWriteTimeout = (HZ / 1000) + 1;
+ struct cfi_private *cfi = map->fldrv_priv;
+ int retry_cnt = 0;
+ map_word oldd;
+ int ret = 0;
+ int i;
+
+ adr += chip->start;
+
+ ret = cfi_amdstd_panic_wait(map, chip, adr);
+ if (ret)
+ return ret;
+
+ pr_debug("MTD %s(): PANIC WRITE 0x%.8lx(0x%.8lx)\n",
+ __func__, adr, datum.x[0]);
+
+ /*
+ * Check for a NOP for the case when the datum to write is already
+ * present - it saves time and works around buggy chips that corrupt
+ * data at other locations when 0xff is written to a location that
+ * already contains 0xff.
+ */
+ oldd = map_read(map, adr);
+ if (map_word_equal(map, oldd, datum)) {
+ pr_debug("MTD %s(): NOP\n", __func__);
+ goto op_done;
+ }
+
+ ENABLE_VPP(map);
+
+retry:
+ cfi_send_gen_cmd(0xAA, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0x55, cfi->addr_unlock2, chip->start, map, cfi, cfi->device_type, NULL);
+ cfi_send_gen_cmd(0xA0, cfi->addr_unlock1, chip->start, map, cfi, cfi->device_type, NULL);
+ map_write(map, datum, adr);
+
+ for (i = 0; i < jiffies_to_usecs(uWriteTimeout); i++) {
+ if (chip_ready(map, adr))
+ break;
+
+ udelay(1);
+ }
+
+ if (!chip_good(map, adr, datum)) {
+ /* reset on all failures. */
+ map_write(map, CMD(0xF0), chip->start);
+ /* FIXME - should have reset delay before continuing */
+
+ if (++retry_cnt <= MAX_WORD_RETRIES)
+ goto retry;
+
+ ret = -EIO;
+ }
+
+op_done:
+ DISABLE_VPP(map);
+ return ret;
+}
+
+/*
+ * Write out some data during a kernel panic
+ *
+ * This is used by the mtdoops driver to save the dying messages from a
+ * kernel which has panic'd.
+ *
+ * This routine ignores all of the locking used throughout the rest of the
+ * driver, in order to ensure that the data gets written out no matter what
+ * state this driver (and the flash chip itself) was in when the kernel crashed.
+ *
+ * The implementation of this routine is intentionally similar to
+ * cfi_amdstd_write_words(), in order to ease code maintenance.
+ */
+static int cfi_amdstd_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
+ size_t *retlen, const u_char *buf)
+{
+ struct map_info *map = mtd->priv;
+ struct cfi_private *cfi = map->fldrv_priv;
+ unsigned long ofs, chipstart;
+ int ret = 0;
+ int chipnum;
+
+ chipnum = to >> cfi->chipshift;
+ ofs = to - (chipnum << cfi->chipshift);
+ chipstart = cfi->chips[chipnum].start;
+
+ /* If it's not bus aligned, do the first byte write */
+ if (ofs & (map_bankwidth(map) - 1)) {
+ unsigned long bus_ofs = ofs & ~(map_bankwidth(map) - 1);
+ int i = ofs - bus_ofs;
+ int n = 0;
+ map_word tmp_buf;
+
+ ret = cfi_amdstd_panic_wait(map, &cfi->chips[chipnum], bus_ofs);
+ if (ret)
+ return ret;
+
+ /* Load 'tmp_buf' with old contents of flash */
+ tmp_buf = map_read(map, bus_ofs + chipstart);
+
+ /* Number of bytes to copy from buffer */
+ n = min_t(int, len, map_bankwidth(map) - i);
+
+ tmp_buf = map_word_load_partial(map, tmp_buf, buf, i, n);
+
+ ret = do_panic_write_oneword(map, &cfi->chips[chipnum],
+ bus_ofs, tmp_buf);
+ if (ret)
+ return ret;
+
+ ofs += n;
+ buf += n;
+ (*retlen) += n;
+ len -= n;
+
+ if (ofs >> cfi->chipshift) {
+ chipnum++;
+ ofs = 0;
+ if (chipnum == cfi->numchips)
+ return 0;
+ }
+ }
+
+ /* We are now aligned, write as much as possible */
+ while (len >= map_bankwidth(map)) {
+ map_word datum;
+
+ datum = map_word_load(map, buf);
+
+ ret = do_panic_write_oneword(map, &cfi->chips[chipnum],
+ ofs, datum);
+ if (ret)
+ return ret;
+
+ ofs += map_bankwidth(map);
+ buf += map_bankwidth(map);
+ (*retlen) += map_bankwidth(map);
+ len -= map_bankwidth(map);
+
+ if (ofs >> cfi->chipshift) {
+ chipnum++;
+ ofs = 0;
+ if (chipnum == cfi->numchips)
+ return 0;
+
+ chipstart = cfi->chips[chipnum].start;
+ }
+ }
+
+ /* Write the trailing bytes if any */
+ if (len & (map_bankwidth(map) - 1)) {
+ map_word tmp_buf;
+
+ ret = cfi_amdstd_panic_wait(map, &cfi->chips[chipnum], ofs);
+ if (ret)
+ return ret;
+
+ tmp_buf = map_read(map, ofs + chipstart);
+
+ tmp_buf = map_word_load_partial(map, tmp_buf, buf, 0, len);
+
+ ret = do_panic_write_oneword(map, &cfi->chips[chipnum],
+ ofs, tmp_buf);
+ if (ret)
+ return ret;
+
+ (*retlen) += len;
+ }
+
+ return 0;
+}
+
/*
* Handle devices with one erase region, that only implement
@@ -1649,6 +1868,7 @@ static int __xipram do_erase_chip(struct map_info *map, struct flchip *chip)
chip->state = FL_READY;
xip_enable(map, chip, adr);
+ DISABLE_VPP(map);
put_chip(map, chip, adr);
mutex_unlock(&chip->mutex);
@@ -1739,6 +1959,7 @@ static int __xipram do_erase_oneblock(struct map_info *map, struct flchip *chip,
}
chip->state = FL_READY;
+ DISABLE_VPP(map);
put_chip(map, chip, adr);
mutex_unlock(&chip->mutex);
return ret;